WorldWideScience

Sample records for demonstration vehicle dynamics

  1. Launch Vehicle Dynamics Demonstrator Model

    Science.gov (United States)

    1963-01-01

    Launch Vehicle Dynamics Demonstrator Model. The effect of vibration on launch vehicle dynamics was studied. Conditions included three modes of instability. The film includes close up views of the simulator fuel tank with and without stability control. [Entire movie available on DVD from CASI as Doc ID 20070030984. Contact help@sti.nasa.gov

  2. Propane Vehicle Demonstration Grant Program

    Energy Technology Data Exchange (ETDEWEB)

    Jack Mallinger

    2004-08-27

    Project Description: Propane Vehicle Demonstration Grants The Propane Vehicle Demonstration Grants was established to demonstrate the benefits of new propane equipment. The US Department of Energy, the Propane Education & Research Council (PERC) and the Propane Vehicle Council (PVC) partnered in this program. The project impacted ten different states, 179 vehicles, and 15 new propane fueling facilities. Based on estimates provided, this project generated a minimum of 1,441,000 new gallons of propane sold for the vehicle market annually. Additionally, two new off-road engines were brought to the market. Projects originally funded under this project were the City of Portland, Colorado, Kansas City, Impco Technologies, Jasper Engines, Maricopa County, New Jersey State, Port of Houston, Salt Lake City Newspaper, Suburban Propane, Mutual Liquid Propane and Ted Johnson.

  3. Demonstration of the Dynamic Flowgraph Methodology using the Titan 2 Space Launch Vehicle Digital Flight Control System

    Science.gov (United States)

    Yau, M.; Guarro, S.; Apostolakis, G.

    1993-01-01

    Dynamic Flowgraph Methodology (DFM) is a new approach developed to integrate the modeling and analysis of the hardware and software components of an embedded system. The objective is to complement the traditional approaches which generally follow the philosophy of separating out the hardware and software portions of the assurance analysis. In this paper, the DFM approach is demonstrated using the Titan 2 Space Launch Vehicle Digital Flight Control System. The hardware and software portions of this embedded system are modeled in an integrated framework. In addition, the time dependent behavior and the switching logic can be captured by this DFM model. In the modeling process, it is found that constructing decision tables for software subroutines is very time consuming. A possible solution is suggested. This approach makes use of a well-known numerical method, the Newton-Raphson method, to solve the equations implemented in the subroutines in reverse. Convergence can be achieved in a few steps.

  4. Vehicle to Grid Demonstration Project

    Energy Technology Data Exchange (ETDEWEB)

    Willett Kempton; Meryl Gardner; Michael Hidrue; Fouad Kamilev; Sachin Kamboj; Jon Lilley; Rodney McGee; George Parsons; Nat Pearre; Keith Trnka

    2010-12-31

    This report summarizes the activities and accomplishments of a two-year DOE-funded project on Grid-Integrated Vehicles (GIV) with vehicle to grid power (V2G). The project included several research and development components: an analysis of US driving patterns; an analysis of the market for EVs and V2G-capable EVs; development and testing of GIV components (in-car and in-EVSE); interconnect law and policy; and development and filing of patents. In addition, development activities included GIV manufacturing and licensing of technologies developed under this grant. Also, five vehicles were built and deployed, four for the fleet of the State of Delaware, plus one for the University of Delaware fleet.

  5. Vehicle Dynamics and Control

    CERN Document Server

    Rajamani, Rajesh

    2012-01-01

    Vehicle Dynamics and Control provides a comprehensive coverage of vehicle control systems and the dynamic models used in the development of these control systems. The control system applications covered in the book include cruise control, adaptive cruise control, ABS, automated lane keeping, automated highway systems, yaw stability control, engine control, passive, active and semi-active suspensions, tire-road friction coefficient estimation, rollover prevention, and hybrid electric vehicle. In developing the dynamic model for each application, an effort is made to both keep the model simple enough for control system design but at the same time rich enough to capture the essential features of the dynamics. A special effort has been made to explain the several different tire models commonly used in literature and to interpret them physically. In the second edition of the book, chapters on roll dynamics, rollover prevention and hybrid electric vehicles have been added, and the chapter on electronic stability co...

  6. Dynamics of aerospace vehicles

    Science.gov (United States)

    Schmidt, David K.

    1991-01-01

    The focus of this research was to address the modeling, including model reduction, of flexible aerospace vehicles, with special emphasis on models used in dynamic analysis and/or guidance and control system design. In the modeling, it is critical that the key aspects of the system being modeled be captured in the model. In this work, therefore, aspects of the vehicle dynamics critical to control design were important. In this regard, fundamental contributions were made in the areas of stability robustness analysis techniques, model reduction techniques, and literal approximations for key dynamic characteristics of flexible vehicles. All these areas are related. In the development of a model, approximations are always involved, so control systems designed using these models must be robust against uncertainties in these models.

  7. Launch Vehicle Demonstrator Using Shuttle Assets

    Science.gov (United States)

    Threet, Grady E., Jr.; Creech, Dennis M.; Philips, Alan D.; Water, Eric D.

    2011-01-01

    The Marshall Space Flight Center Advanced Concepts Office (ACO) has the leading role for NASA s preliminary conceptual launch vehicle design and performance analysis. Over the past several years the ACO Earth-to-Orbit Team has evaluated thousands of launch vehicle concept variations for a multitude of studies including agency-wide efforts such as the Exploration Systems Architecture Study (ESAS), Constellation, Heavy Lift Launch Vehicle (HLLV), Heavy Lift Propulsion Technology (HLPT), Human Exploration Framework Team (HEFT), and Space Launch System (SLS). NASA plans to continue human space exploration and space station utilization. Launch vehicles used for heavy lift cargo and crew will be needed. One of the current leading concepts for future heavy lift capability is an inline one and a half stage concept using solid rocket boosters (SRB) and based on current Shuttle technology and elements. Potentially, the quickest and most cost-effective path towards an operational vehicle of this configuration is to make use of a demonstrator vehicle fabricated from existing shuttle assets and relying upon the existing STS launch infrastructure. Such a demonstrator would yield valuable proof-of-concept data and would provide a working test platform allowing for validated systems integration. Using shuttle hardware such as existing RS-25D engines and partial MPS, propellant tanks derived from the External Tank (ET) design and tooling, and four-segment SRB s could reduce the associated upfront development costs and schedule when compared to a concept that would rely on new propulsion technology and engine designs. There are potentially several other additional benefits to this demonstrator concept. Since a concept of this type would be based on man-rated flight proven hardware components, this demonstrator has the potential to evolve into the first iteration of heavy lift crew or cargo and serve as a baseline for block upgrades. This vehicle could also serve as a demonstration

  8. Vehicle dynamics theory and application

    CERN Document Server

    Jazar, Reza N

    2017-01-01

    This intermediate textbook is appropriate for students in vehicle dynamics courses, in their last year of undergraduate study or their first year of graduate study. It is also appropriate for mechanical engineers, automotive engineers, and researchers in the area of vehicle dynamics for continuing education or as a reference. It addresses fundamental and advanced topics, and a basic knowledge of kinematics and dynamics, as well as numerical methods, is expected. The contents are kept at a theoretical-practical level, with a strong emphasis on application. This third edition has been reduced by 25%, to allow for coverage over one semester, as opposed to the previous edition that needed two semesters for coverage. The textbook is composed of four parts: Vehicle Motion: covers tire dynamics, forward vehicle dynamics, and driveline dynamics Vehicle Kinematics: covers applied kinematics, applied mechanisms, steering dynamics, and suspension mechanisms Vehicle Dynamics: covers applied dynamics, vehicle planar dynam...

  9. Rail vehicle dynamics

    CERN Document Server

    Knothe, Klaus

    2017-01-01

    This book on the dynamics of rail vehicles is developed from the manuscripts for a class with the same name at TU Berlin. It is directed mainly to master students with pre-knowledge in mathematics and mechanics and engineers that want to learn more. The important phenomena of the running behaviour of rail vehicles are derived and explained. Also recent research results and experience from the operation of rail vehicles are included. One focus is the description of the complex wheel-rail contact phenomena that are essential to understand the concept of running stability and curving. A reader should in the end be able to understand the background of simulation tools that are used by the railway industry and universities today.

  10. Medium Duty Electric Vehicle Demonstration Project

    Energy Technology Data Exchange (ETDEWEB)

    Mackie, Robin J. D. [Smith Electric Vehicles Corporation, Kansas City, MO (United States)

    2015-05-31

    The Smith Electric Vehicle Demonstration Project (SDP) was integral to the Smith business plan to establish a manufacturing base in the United States (US) and produce a portfolio of All Electric Vehicles (AEV’s) for the medium duty commercial truck market. Smith focused on the commercial depot based logistics market, as it represented the market that was most ready for the early adoption of AEV technology. The SDP enabled Smith to accelerate its introduction of vehicles and increase the size of its US supply chain to support early market adoption of AEV’s that were cost competitive, fully met the needs of a diverse set of end users and were compliant with Federal safety and emissions requirements. The SDP accelerated the development and production of various electric drive vehicle systems to substantially reduce petroleum consumption, reduce vehicular emissions of greenhouse gases (GHG), and increase US jobs.

  11. Delay of Vehicle Motion in Traffic Dynamics

    CERN Document Server

    Bando, M; Nakanishi, K; Nakayama, A; Bando, Masako; Hasebe, Katsuya; Nakanishi, Ken; Nakayama, Akihiro

    1996-01-01

    We demonstrate that in Optimal Velocity Model (OVM) delay times of vehicles coming from the dynamical equation of motion of OVM almost explain the order of delay times observed in actual traffic flows without introducing explicit delay times. Delay times in various cases are estimated: the case of a leader vehicle and its follower, a queue of vehicles controlled by traffic lights and many-vehicle case of highway traffic flow. The remarkable result is that in most of the situation for which we can make a reasonable definition of a delay time, the obtained delay time is of order 1 second.

  12. Demonstration of Heavy Hybrid Diesel Fleet Vehicles

    Science.gov (United States)

    2016-03-01

    losses due to uneven pavement , and representative of most installations. • Track Weather Station: ATC setup equipment to measure and record weather...the conventional utility truck provide a better, more rigid ride. Acceleration of the vehicle is very poor. The vehicles continuously fall behind

  13. Variable Dynamic Testbed Vehicle: Dynamics Analysis

    Science.gov (United States)

    Lee, A. Y.; Le, N. T.; Marriott, A. T.

    1997-01-01

    The Variable Dynamic Testbed Vehicle (VDTV) concept has been proposed as a tool to evaluate collision avoidance systems and to perform driving-related human factors research. The goal of this study is to analytically investigate to what extent a VDTV with adjustable front and rear anti-roll bar stiffnesses, programmable damping rates, and four-wheel-steering can emulate the lateral dynamics of a broad range of passenger vehicles.

  14. High dynamic GPS receiver validation demonstration

    Science.gov (United States)

    Hurd, W. J.; Statman, J. I.; Vilnrotter, V. A.

    1985-01-01

    The Validation Demonstration establishes that the high dynamic Global Positioning System (GPS) receiver concept developed at JPL meets the dynamic tracking requirements for range instrumentation of missiles and drones. It was demonstrated that the receiver can track the pseudorange and pseudorange rate of vehicles with acceleration in excess of 100 g and jerk in excess of 100 g/s, dynamics ten times more severe than specified for conventional High Dynamic GPS receivers. These results and analytic extensions to a complete system configuration establish that all range instrumentation requirements can be met. The receiver can be implemented in the 100 cu in volume required by all missiles and drones, and is ideally suited for transdigitizer or translator applications.

  15. Dynamics of vehicle-road coupled system

    CERN Document Server

    Yang, Shaopu; Li, Shaohua

    2015-01-01

    Vehicle dynamics and road dynamics are usually considered to be two largely independent subjects. In vehicle dynamics, road surface roughness is generally regarded as random excitation of the vehicle, while in road dynamics, the vehicle is generally regarded as a moving load acting on the pavement. This book suggests a new research concept to integrate the vehicle and the road system with the help of a tire model, and establishes a cross-subject research framework dubbed vehicle-pavement coupled system dynamics. In this context, the dynamics of the vehicle, road and the vehicle-road coupled system are investigated by means of theoretical analysis, numerical simulations and field tests. This book will be a valuable resource for university professors, graduate students and engineers majoring in automotive design, mechanical engineering, highway engineering and other related areas. Shaopu Yang is a professor and deputy president of Shijiazhuang Tiedao University, China; Liqun Chen is a professor at Shanghai Univ...

  16. Remote control of an impact demonstration vehicle

    Science.gov (United States)

    Harney, P. F.; Craft, J. B., Jr.; Johnson, R. G.

    1985-01-01

    Uplink and downlink telemetry systems were installed in a Boeing 720 aircraft that was remotely flown from Rogers Dry Lake at Edwards Air Force Base and impacted into a designated crash site on the lake bed. The controlled impact demonstration (CID) program was a joint venture by the National Aeronautics and Space Administration (NASA) and the Federal Aviation Administration (FAA) to test passenger survivability using antimisting kerosene (AMK) to inhibit postcrash fires, improve passenger seats and restraints, and improve fire-retardent materials. The uplink telemetry system was used to remotely control the aircraft and activate onboard systems from takeoff until after impact. Aircraft systems for remote control, aircraft structural response, passenger seat and restraint systems, and anthropomorphic dummy responses were recorded and displayed by the downlink stems. The instrumentation uplink and downlink systems are described.

  17. Dynamics and Control of a Maglev Vehicle

    Directory of Open Access Journals (Sweden)

    Won ko

    2006-06-01

    Full Text Available In this paper, dynamics of a Maglev vehicle was analyzed and controls utilizing an optimized damping and an LQR algorithms were designed to stabilize the vehicle. The dynamics of magnetically levitated and propelled Maglev vehicle are complex and inherently unstable. Moreover, 6-DOF system dynamics is highly nonlinear and coupled. The proposed control schemes provide the dynamic stability and controllability, which computer simulations confirmed the effectiveness.

  18. Constraint Embedding for Vehicle Suspension Dynamics

    Directory of Open Access Journals (Sweden)

    Jain Abhinandan

    2016-06-01

    Full Text Available The goal of this research is to achieve close to real-time dynamics performance for allowing auto-pilot in-the-loop testing of unmanned ground vehicles (UGV for urban as well as off-road scenarios. The overall vehicle dynamics performance is governed by the multibody dynamics model for the vehicle, the wheel/terrain interaction dynamics and the onboard control system. The topic of this paper is the development of computationally efficient and accurate dynamics model for ground vehicles with complex suspension dynamics. A challenge is that typical vehicle suspensions involve closed-chain loops which require expensive DAE integration techniques. In this paper, we illustrate the use the alternative constraint embedding technique to reduce the cost and improve the accuracy of the dynamics model for the vehicle.

  19. State estimation for integrated vehicle dynamics control

    NARCIS (Netherlands)

    Zuurbier, J.; Bremmer, P.

    2002-01-01

    This paper discusses a vehicle controller and a state estimator that was implemented and tested in a vehicle equipped with a combined braking and chassis control system to improve handling. The vehicle dynamics controller consists of a feed forward body roll compensation and a feedback stability con

  20. Vehicle dynamics theory and application

    CERN Document Server

    Jazar, Reza N

    2014-01-01

    This textbook is appropriate for senior undergraduate and first year graduate students in mechanical and automotive engineering. The contents in this book are presented at a theoretical-practical level. It explains vehicle dynamics concepts in detail, concentrating on their practical use. Related theorems and formal proofs are provided, as are real-life applications. Students, researchers and practicing engineers alike will appreciate the user-friendly presentation of a wealth of topics, most notably steering, handling, ride, and related components. This book also: Illustrates all key concepts with examples Includes exercises for each chapter Covers front, rear, and four wheel steering systems, as well as the advantages and disadvantages of different steering schemes Includes an emphasis on design throughout the text, which provides a practical, hands-on approach

  1. Demonstration of Alternative Fuel, Light and Heavy Duty Vehicles in State and Municipal Vehicle Fleets

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, John H.; Polubiatko, Peter; Tucchio, Michael A.

    2002-02-06

    This project involved the purchase of two Compressed Natural Gas School Buses and two electric Ford Rangers to demonstrate their viability in a municipal setting. Operational and maintenance data were collected for analysis. In addition, an educational component was undertaken with middle school children. The children observed and calculated how electric vehicles could minimize pollutants through comparison to conventionally powered vehicles.

  2. Dynamic Analysis of a Military- Tracked Vehicle

    Directory of Open Access Journals (Sweden)

    V. Balamurugan

    2000-04-01

    Full Text Available 'The ride dynamic characteristics of a typical medium weight, high speed military-tracked vehicle for negotiating rough cross-counlry terrain have been studied. The vehicle is modelled using finiteelement simulation method with beam and shell elements. An eigenvalue analysis has been done to estimate natural modes ofNibration of the vehicle. The dynamic response of certain salient locations is obtained by carrying out a transient dynamic analysis using implicit Newmark beta method. A constant forwar vehicle speed and non-deformable sinusoidal terrain profile are assumed.

  3. Classification of Dynamic Vehicle Routing Systems

    DEFF Research Database (Denmark)

    Larsen, Allan; Madsen, Oli B.G.; Solomon, Marius M.

    2007-01-01

    to classify dynamic vehicle routing systems. Methods for evaluation of the performance of algorithms that solve on-line routing problems are discussed and we list some of the most important issues to include in the system objective. Finally, we provide a three-echelon classification of dynamic vehicle routing...

  4. 2014 ITS World Congress Connected Vehicle Test Bed Demonstration Vehicle Situation Data

    Data.gov (United States)

    Department of Transportation — During the 2014 ITS World Congress a demonstration of the connected vehicle infrastructure in the City of Detroit was conducted. The test site included approximately...

  5. National Fuel Cell Electric Vehicle Learning Demonstration Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Wipke, K. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Sprik, S. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Kurtz, J. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Ramsden, T. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Ainscough, C. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Saur, G. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2012-07-01

    This report discusses key analysis results based on data from early 2005 through September 2011 from the U.S. Department of Energy’s (DOE’s) Controlled Hydrogen Fleet and Infrastructure Validation and Demonstration Project, also referred to as the National Fuel Cell Electric Vehicle (FCEV) Learning Demonstration. It is the fifth and final such report in a series, with previous reports being published in July 2007, November 2007, April 2008, and September 2010.

  6. Vehicle Dynamic Prediction Systems with On-Line Identification of Vehicle Parameters and Road Conditions

    OpenAIRE

    Ling-Yuan Hsu; Tsung-Lin Chen

    2012-01-01

    This paper presents a vehicle dynamics prediction system, which consists of a sensor fusion system and a vehicle parameter identification system. This sensor fusion system can obtain the six degree-of-freedom vehicle dynamics and two road angles without using a vehicle model. The vehicle parameter identification system uses the vehicle dynamics from the sensor fusion system to identify ten vehicle parameters in real time, including vehicle mass, moment of inertial, and road friction coefficie...

  7. National Fuel Cell Electric Vehicle Learning Demonstration Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Wipke, K.; Sprik, S.; Kurtz, J.; Ramsden, T.; Ainscough, C.; Saur, G.

    2012-07-01

    This report discusses key analysis results based on data from early 2005 through September 2011 from the U.S. Department of Energy's (DOE's) Controlled Hydrogen Fleet and Infrastructure Validation and Demonstration Project, also referred to as the National Fuel Cell Electric Vehicle (FCEV) Learning Demonstration. This report serves as one of many mechanisms to help transfer knowledge and lessons learned within various parts of DOE's Fuel Cell Technologies Program, as well as externally to other stakeholders. It is the fifth and final such report in a series, with previous reports being published in July 2007, November 2007, April 2008, and September 2010.

  8. Vehicle lateral dynamics stabilization using active suspension

    Directory of Open Access Journals (Sweden)

    Drobný V.

    2008-12-01

    Full Text Available The paper deals with the investigation of active nonlinear suspension control in order to stabilize the lateral vehicle motion in similar way as systems like ESP do. The lateral stabilization of vehicle based on braking forces can be alternatively provided by the different setting of suspension forces. The basis of this control is the nonlinear property of the tyres. The vehicle has at least four wheels and it gives one or more redundant vertical forces that can be used for the different distribution of vertical suspension forces in such a way that resulting lateral and/or longitudinal forces create the required correction moment for lateral dynamic vehicle stabilization.

  9. Lateral dynamic features of a railway vehicle

    DEFF Research Database (Denmark)

    Gao, Xue-jun; True, Hans; Li, Ying-hui

    2016-01-01

    The lateral dynamic features of a railway vehicle are investigated using two similar wheel/rail contact models: the Vermeulen-Johnson and the Shen-Hedrick-Elkins models. The symmetric/asymmetric bifurcation behaviour and chaotic motions of the railway vehicle are investigated in great detail...... by varying the speed and using the resultant bifurcation diagram' method. It is found that multiple solution branches exist and they can lead to more steady states in the dynamic behaviour of the railway vehicle. The coexistence of multiple steady states can lead to jumps in the amplitude of oscillations...

  10. U32: Vehicle Stability and Dynamics: Longer Combination Vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Petrolino, Joseph [National Transportation Research Center (NTRC); Spezia, Tony [National Transportation Research Center (NTRC); Arant, Michael [Clemson University; Broshears, Eric [Auburn University, Auburn, Alabama; Chitwood, Caleb [Battelle; Colbert, Jameson [Auburn University, Auburn, Alabama; Hathaway, Richard [Western Michigan University; Keil, Mitch [Western Michigan University; LaClair, Tim J [ORNL; Pape, Doug [Battelle; Patterson, Jim [Hendrickson; Pittro, Collin [Battelle

    2011-01-01

    This study investigated the safety and stability of longer combination vehicles (LCVs), in particular a triple trailer combination behind a commercial tractor, which has more complicated dynamics than the more common tractor in combination with a single semitrailer. The goal was to measure and model the behavior of LCVs in simple maneuvers. Example maneuvers tested and modeled were single and double lane changes, a gradual lane change, and a constant radius curve. In addition to test track data collection and a brief highway test, two computer models of LCVs were developed. One model is based on TruckSim , a lumped parameter model widely used for single semitrailer combinations. The other model was built in Adams software, which more explicitly models the geometry of the components of the vehicle, in terms of compliant structural members. Among other results, the models were able to duplicate the experimentally measured rearward amplification behavior that is characteristic of multi-unit combination vehicles.

  11. Flight Dynamics and Control of Elastic Hypersonic Vehicles Uncertainty Modeling

    Science.gov (United States)

    Chavez, Frank R.; Schmidt, David K.

    1994-01-01

    It has been shown previously that hypersonic air-breathing aircraft exhibit strong aeroelastic/aeropropulsive dynamic interactions. To investigate these, especially from the perspective of the vehicle dynamics and control, analytical expressions for key stability derivatives were derived, and an analysis of the dynamics was performed. In this paper, the important issue of model uncertainty, and the appropriate forms for representing this uncertainty, is addressed. It is shown that the methods suggested in the literature for analyzing the robustness of multivariable feedback systems, which as a prerequisite to their application assume particular forms of model uncertainty, can be difficult to apply on real atmospheric flight vehicles. Also, the extent to which available methods are conservative is demonstrated for this class of vehicle dynamics.

  12. Vehicle Dynamics Approach to Driver Warning

    Directory of Open Access Journals (Sweden)

    Youssef A. Ghoneim

    2013-01-01

    Full Text Available This paper discusses a concept for enhanced active safety by introducing a driver warning system based on vehicle dynamics that predicts a potential loss of control condition prior to stability control activation. This real-time warning algorithm builds on available technologies such as the Electronic Stability Control (ESC. The driver warning system computes several indices based on yaw rate, side-slip velocity, and vehicle understeer using ESC sensor suite. An arbitrator block arbitrates between the different indices and determines the status index of the driving vehicle. The status index is compared to predetermined stability levels which correspond to high and low stability levels. If the index exceeds the high stability level, a warning signal (haptic, acoustic, or visual is issued to alert the driver of a potential loss of control and ESC activation. This alert will remain in effect until the index is less than the low stability level at which time the warning signal will be terminated. A vehicle speed advisory algorithm is integrated with the warning algorithm to provide a desired vehicle speed of a vehicle traveling on a curve. Simulation results and vehicle tests were conducted to illustrate the effectiveness of the warning algorithm.

  13. Dynamic analysis of rail vehicle axle

    Indian Academy of Sciences (India)

    Ferhat Dikmen; Meral Bayraktar; Rahmi Guclu

    2013-04-01

    In this paper, in order to obtain the dynamic forces on the passenger coach axle, a full rail vehicle model with 19-dof (degrees of freedom) has been considered. For a specific example, the variations of these dynamic forces with velocity of the passenger coach, suspension characteristics and way conditions have been examined. Dynamic forces found in the resonance regions at the range of 2–5 m/s (7.2–18 km/h) has been discussed. Theoretical results obtained for the dynamic forces have been successfully compared with the experimental results of German Railways (Deutsche Bahn-DB).

  14. Dynamics of Railway Vehicles and Rail/Wheel Contact

    DEFF Research Database (Denmark)

    True, Hans

    2007-01-01

    of the most important dynamic effects on vehicle dynamic problems are described. In chapter 7 characteristic features of railway vehicle dynamics are described, and in chapter 8 recommendations are presented for the numerical handling that is necessary for the investigation of vehicle dynamic problems...

  15. Vehicle dynamics modeling and simulation

    CERN Document Server

    Schramm, Dieter; Bardini, Roberto

    2014-01-01

    The authors examine in detail the fundamentals and mathematical descriptions of the dynamics of automobiles. In this context different levels of complexity will be presented, starting with basic single-track models up to complex three-dimensional multi-body models. A particular focus is on the process of establishing mathematical models on the basis of real cars and the validation of simulation results. The methods presented are explained in detail by means of selected application scenarios.

  16. DYNAMIC ANALYSIS OF A VEHICLE CLUTCH

    Directory of Open Access Journals (Sweden)

    Emin GÜLLÜ

    2003-03-01

    Full Text Available In this study as a first step of an ongoing investigation, a dynamic model was developed to analyse motion and power transmission phenomen in mechanical clutches used commonly in motor vehicles . The control of a driver on clutch and speed pedals was reflected in the model. The movement of clutch disk with constant speed and acceleration can be investigated by using the model. In addition, the control of speeding by driver was included to the model via a certain scenario. During clutch engagement and after, the effects of loading torques in different gears on the time of perfect engagement and on the speed of the vehicle were investigated.

  17. Lincoln Laboratory demonstrates highly accurate vehicle localization under adverseweather conditions

    Science.gov (United States)

    2016-06-24

    governments know when roads and bridges are in need of maintenance. Uses of LGPR for indoor and underground navigation , such as in mining, also remain to be...enhances an autonomous vehicle’s ability to know its position on a roadway even when other approaches fail. During a mid-March snowstorm, researchers...the problems limiting the development and adoption of self-driving vehicles: how can a vehicle navigate to stay within its lane when bad weather

  18. City of Las Vegas Plug-in Hybrid Electric Vehicle Demonstration Program

    Energy Technology Data Exchange (ETDEWEB)

    None

    2013-12-31

    The City of Las Vegas was awarded Department of Energy (DOE) project funding in 2009, for the City of Las Vegas Plug-in Hybrid Electric Vehicle Demonstration Program. This project allowed the City of Las Vegas to purchase electric and plug-in hybrid electric vehicles and associated electric vehicle charging infrastructure. The City anticipated the electric vehicles having lower overall operating costs and emissions similar to traditional and hybrid vehicles.

  19. Vehicle dynamic prediction systems with on-line identification of vehicle parameters and road conditions.

    Science.gov (United States)

    Hsu, Ling-Yuan; Chen, Tsung-Lin

    2012-01-01

    This paper presents a vehicle dynamics prediction system, which consists of a sensor fusion system and a vehicle parameter identification system. This sensor fusion system can obtain the six degree-of-freedom vehicle dynamics and two road angles without using a vehicle model. The vehicle parameter identification system uses the vehicle dynamics from the sensor fusion system to identify ten vehicle parameters in real time, including vehicle mass, moment of inertial, and road friction coefficients. With above two systems, the future vehicle dynamics is predicted by using a vehicle dynamics model, obtained from the parameter identification system, to propagate with time the current vehicle state values, obtained from the sensor fusion system. Comparing with most existing literatures in this field, the proposed approach improves the prediction accuracy both by incorporating more vehicle dynamics to the prediction system and by on-line identification to minimize the vehicle modeling errors. Simulation results show that the proposed method successfully predicts the vehicle dynamics in a left-hand turn event and a rollover event. The prediction inaccuracy is 0.51% in a left-hand turn event and 27.3% in a rollover event.

  20. Nonlinear Dynamic Characteristics of the Railway Vehicle

    Science.gov (United States)

    Uyulan, Çağlar; Gokasan, Metin

    2017-06-01

    The nonlinear dynamic characteristics of a railway vehicle are checked into thoroughly by applying two different wheel-rail contact model: a heuristic nonlinear friction creepage model derived by using Kalker 's theory and Polach model including dead-zone clearance. This two models are matched with the quasi-static form of the LuGre model to obtain more realistic wheel-rail contact model. LuGre model parameters are determined using nonlinear optimization method, which it's objective is to minimize the error between the output of the Polach and Kalker model and quasi-static LuGre model for specific operating conditions. The symmetric/asymmetric bifurcation attitude and stable/unstable motion of the railway vehicle in the presence of nonlinearities which are yaw damping forces in the longitudinal suspension system are analyzed in great detail by changing the vehicle speed. Phase portraits of the lateral displacement of the leading wheelset of the railway vehicle are drawn below and on the critical speeds, where sub-critical Hopf bifurcation take place, for two wheel-rail contact model. Asymmetric periodic motions have been observed during the simulation in the lateral displacement of the wheelset under different vehicle speed range. The coexistence of multiple steady states cause bounces in the amplitude of vibrations, resulting instability problems of the railway vehicle. By using Lyapunov's indirect method, the critical hunting speeds are calculated with respect to the radius of the curved track parameter changes. Hunting, which is defined as the oscillation of the lateral displacement of wheelset with a large domain, is described by a limit cycle-type oscillation nature. The evaluated accuracy of the LuGre model adopted from Kalker's model results for prediction of critical speed is higher than the results of the LuGre model adopted from Polach's model. From the results of the analysis, the critical hunting speed must be resolved by investigating the track tests

  1. Demonstration of Tar Removal from Paving Equipment and Ground Vehicles

    Science.gov (United States)

    2011-05-12

    difficult job . Red River Army Depot has about 25 vehicles for refurbishing. Other equipment can also be recovered if a convenient solvent and process...solvents including ethyl lactate , dibasic esters, and X-Force were tested with little success. An aqueous solution formulated with

  2. Longitudinal dynamic stability of a shuttle vehicle.

    Science.gov (United States)

    Vinh, N. X.; Laitone, E. V.

    1972-01-01

    Analytical study of the longitudinal dynamic stability of a nonrolling, lifting vehicle gliding at hypersonic speeds. The analysis applies to shuttle vehicles designed for operating up to the rim of a planetary atmosphere. A general nondimensional time transformation is introduced to derive a unified second-order linear differential equation for the angle of attack, valid for all types of reentry of a general type of vehicle. The stability of motion is discussed for two fundamental regimes of flight that are based on widely different assumptions. For near ballistic entry along a straight line trajectory, the equation reduces to a confluent hypergeometric equation, the solution of which can be expressed in terms of Whittaker's function. Using a theorem in the theory of stability of differential equations, criteria for damped oscillations are derived. It is shown that the aerodynamic criteria for stability are the same as for the case of ballistic entry. In addition, for each vehicle configuration, and specified planetary atmosphere, there exists an altitude range where the angle of attack frequency is nearly equal to the orbital frequency causing instability in pitch. This resonance instability is due to the ellipticity of the orbit. Criteria for eccentricity instability are derived.

  3. Dynamic tensegrity based cooperative control of uninhabited vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Lau, Sook Yen; Naeem, Wasif [Queen' s Univ., Belfast (United Kingdom). School of Electronics, Electrical Engineering and Computer Science

    2013-07-01

    A new formation control methodology is presented in this paper. The proposed technique is modelled by using the concept of cross-tensegrity structures. The main task is to regulate the desired formation of a group of vehicles and to perform point-to-point manoeuvring in the plane. The position of the controlled vehicles in the formation changes with respect to the admissible tendon forces by varying the lengths of bars in the dynamic tensegrity structure modelling. This change of bars' dimensions for geometric transformation is not possible in the application of tensegrity concept in the physical structural engineering. It has been demonstrated that this control method allows more flexibility over a wide range of different shape switching tasks using the predictable tendon control forces under the limited communication's range. The proposed approach is also scalable to any number of pairs of autonomous vehicles in the formation.

  4. Impact of Vehicle Flexibility on IRVE-II Flight Dynamics

    Science.gov (United States)

    Bose, David M.; Toniolo, Matthew D.; Cheatwood, F. M.; Hughes, Stephen J.; Dillman, Robert A.

    2011-01-01

    The Inflatable Re-entry Vehicle Experiment II (IRVE-II) successfully launched from Wallops Flight Facility (WFF) on August 17, 2009. The primary objectives of this flight test were to demonstrate inflation and re-entry survivability, assess the thermal and drag performance of the reentry vehicle, and to collect flight data for refining pre-flight design and analysis tools. Post-flight analysis including trajectory reconstruction outlined in O Keefe3 demonstrated that the IRVE-II Research Vehicle (RV) met mission objectives but also identified a few anomalies of interest to flight dynamics engineers. Most notable of these anomalies was high normal acceleration during the re-entry pressure pulse. Deflection of the inflatable aeroshell during the pressure pulse was evident in flight video and identified as the likely cause of the anomaly. This paper provides a summary of further post-flight analysis with particular attention to the impact of aeroshell flexibility on flight dynamics and the reconciliation of flight performance with pre-flight models. Independent methods for estimating the magnitude of the deflection of the aeroshell experienced on IRVE-II are discussed. The use of the results to refine models for pre-flight prediction of vehicle performance is then described.

  5. Implementation and Demonstration of Grid Frequency Support by V2G Enabled Electric Vehicle

    DEFF Research Database (Denmark)

    Martinenas, Sergejus; Marinelli, Mattia; Andersen, Peter Bach

    2014-01-01

    of electric vehicles - faster and with better precision, using Vehicle-to-Grid technology. This paper explores the implementation of a system that demonstrates the use of the electric vehicles for providing frequency regulation in the Danish power grid. The system is tested with the use case of Primary...

  6. Vehicle Dynamics due to Magnetic Launch Propulsion

    Science.gov (United States)

    Galaboff, Zachary J.; Jacobs, William; West, Mark E.; Montenegro, Justino (Technical Monitor)

    2000-01-01

    The field of Magnetic Levitation Lind Propulsion (MagLev) has been around for over 30 years, primarily in high-speed rail service. In recent years, however, NASA has been looking closely at MagLev as a possible first stage propulsion system for spacecraft. This approach creates a variety of new problems that don't currently exist with the present MagLev trains around the world. NASA requires that a spacecraft of approximately 120,000 lbs be accelerated at two times the acceleration of gravity (2g's). This produces a greater demand on power over the normal MagLev trains that accelerate at around 0.1g. To be able to store and distribute up to 3,000 Mega Joules of energy in less than 10 seconds is a technical challenge. Another problem never addressed by the train industry and, peculiar only to NASA, is the control of a lifting body through the acceleration of and separation from the MagLev track. Very little is understood about how a lifting body will react with external forces, Such as wind gusts and ground effects, while being propelled along on soft springs such as magnetic levitators. Much study needs to be done to determine spacecraft control requirements as well as what control mechanisms and aero-surfaces should be placed on the carrier. Once the spacecraft has been propelled down the track another significant event takes place, the separation of the spacecraft from the carrier. The dynamics involved for both the carrier and the spacecraft are complex and coupled. Analysis of the reaction of the carrier after losing, a majority of its mass must be performed to insure control of the carrier is maintained and a safe separation of the spacecraft is achieved. The spacecraft angle of attack required for lift and how it will affect the carriage just prior to separation, along with the impacts of around effect and aerodynamic forces at ground level must be modeled and analyzed to define requirements on the launch vehicle design. Mechanisms, which can withstand the

  7. The pitch-heave dynamics of transportation vehicles

    Science.gov (United States)

    Sweet, L. M.; Richardson, H. H.

    1975-01-01

    The analysis and design of suspensions for vehicles of finite length using pitch-heave models is presented. Dynamic models for the finite length vehicle include the spatial distribution of the guideway input disturbance over the vehicle length, as well as both pitch and heave degrees-of-freedom. Analytical results relate the vehicle front and rear accelerations to the pitch and heave natural frequencies, which are functions of vehicle suspension geometry and mass distribution. The effects of vehicle asymmetry and suspension contact area are evaluated. Design guidelines are presented for the modification of vehicle and suspension parameters to meet alternative ride quality criteria.

  8. Off-road vehicle dynamics analysis, modelling and optimization

    CERN Document Server

    Taghavifar, Hamid

    2017-01-01

    This book deals with the analysis of off-road vehicle dynamics from kinetics and kinematics perspectives and the performance of vehicle traversing over rough and irregular terrain. The authors consider the wheel performance, soil-tire interactions and their interface, tractive performance of the vehicle, ride comfort, stability over maneuvering, transient and steady state conditions of the vehicle traversing, modeling the aforementioned aspects and optimization from energetic and vehicle mobility perspectives. This book brings novel figures for the transient dynamics and original wheel terrain dynamics at on-the-go condition.

  9. Demonstration of Launch Vehicle Slosh Instability on Pole-Cart Platform

    Science.gov (United States)

    Pei, Jing; Rothhaar, Paul

    2015-01-01

    Liquid propellant makes up a significant portion of the total weight for large launch vehicles such as Saturn V, Space Shuttle, and the Space Launch System (SLS). Careful attention must be given to the influence of fuel slosh motion on the stability of the vehicle. A well-documented slosh danger zone occurs when the slosh mass is between the vehicle center of mass and the center of percussion. Passive damping via slosh baffle is generally required when the slosh mass is within this region. The pole-cart hardware system, typically used for academic purposes, has similar dynamic characteristics as an unstable launch vehicle. This setup offers a simple and inexpensive way of analyzing slosh dynamics and its impact on flight control design. In this paper, experimental and numerical results from the pole-cart system will be shown and direct analogies to launch vehicle slosh dynamics will be made.

  10. Dynamic formation control for autonomous underwater vehicles

    Institute of Scientific and Technical Information of China (English)

    燕雪峰; 古锋; 宋琛; 胡晓琳; 潘毅

    2014-01-01

    Path planning and formation structure forming are two of the most important problems for autonomous underwater vehicles (AUVs) to collaborate with each other. In this work, a dynamic formation model was proposed, in which several algorithms were developed for the complex underwater environment. Dimension changeable particle swarm algorithm was used to find an optimized path by dynamically adjusting the number and the distribution of the path nodes. Position relationship based obstacle avoidance algorithm was designed to detour along the edges of obstacles. Virtual potential point based formation-keeping algorithm was employed by incorporating dynamic strategies which were decided by the current states of the formation. The virtual potential point was used to keep the formation structure when the AUV or the formation was deviated. Simulation results show that an optimal path can be dynamically planned with fewer path nodes and smaller fitness, even with a concave obstacle. It has been also proven that different formation-keeping strategies can be adaptively selected and the formation can change its structure in a narrow area and restore back after passing the obstacle.

  11. A Dynamic Travel Time Estimation Model Based on Connected Vehicles

    Directory of Open Access Journals (Sweden)

    Daxin Tian

    2015-01-01

    Full Text Available With advances in connected vehicle technology, dynamic vehicle route guidance models gradually become indispensable equipment for drivers. Traditional route guidance models are designed to direct a vehicle along the shortest path from the origin to the destination without considering the dynamic traffic information. In this paper a dynamic travel time estimation model is presented which can collect and distribute traffic data based on the connected vehicles. To estimate the real-time travel time more accurately, a road link dynamic dividing algorithm is proposed. The efficiency of the model is confirmed by simulations, and the experiment results prove the effectiveness of the travel time estimation method.

  12. Spatial multibody modeling and vehicle dynamics analysis of advanced vehicle technologies

    Science.gov (United States)

    Letherwood, Michael D.; Gunter, David D.; Gorsich, David J.; Udvare, Thomas B.

    2004-08-01

    The US Army vision, announced in October of 1999, encompasses people, readiness, and transformation. The goal of the Army vision is to transition the entire Army into a force that is strategically responsive and dominant at every point of the spectrum of operations. The transformation component will be accomplished in three ways: the Objective Force, the Legacy (current) Force, and the Interim Force. The objective force is not platform driven, but rather the focus is on achieving capabilities that will operate as a "system of systems." As part of the Objective Force, the US Army plans to begin production of the Future Combat System (FCS) in FY08 and field the first unit by FY10 as currently defined in the FCS solicitation(1). As part of the FCS program, the Future Tactical Truck System (FTTS) encompasses all US Army tactical wheeled vehicles and its initial efforts will focus only on the heavy class. The National Automotive Center (NAC) is using modeling and simulation to demonstrate the feasibility and operational potential of advanced commercial and military technologies with application to new and existing tactical vehicles and to describe potential future vehicle capabilities. This document will present the results of computer-based, vehicle dynamics performance assessments of FTTS concepts with such features as hybrid power sources, active suspensions, skid steering, and in-hub electric drive motors. Fully three-dimensional FTTS models are being created using commercially available modeling and simulation methodologies such as ADAMS and DADS and limited vehicle dynamics validation studies are will be performed.

  13. Ride Dynamics of a Tracked Vehicle with a Finite Element Vehicle Model

    Directory of Open Access Journals (Sweden)

    S. Jothi

    2016-01-01

    Full Text Available Research on tracked vehicle dynamics is by and large limited to multi-rigid body simulation. For realistic prediction of vehicle dynamics, it is better to model the vehicle as multi-flexible body. In this paper, tracked vehicle is modelled as a mass-spring system with sprung and unsprung masses of the physical tracked vehicle by Finite element method. Using the equivalent vehicle model, dynamic studies are carried out by imparting vertical displacement inputs to the road wheels. Ride characteristics of the vehicle are captured by modelling the road wheel arms as flexible elements using Finite element method. In this work, a typical tracked vehicle test terrain viz., Trapezoidal blocks terrain (APG terrain is considered. Through the simulations, the effect of the road wheel arm flexibility is monitored. Result of the analysis of equivalent vehicle model with flexible road wheel arms, is compared with the equivalent vehicle model with rigid road wheel arms and also with the experimental results of physical tracked vehicle. Though there is no major difference in the vertical bounce response between the flexible model and the rigid model, but there is a visible difference in the roll condition. Result of the flexible vehicle model is also reasonably matches with the experimental result.Defence Science Journal, Vol. 66, No. 1, January 2016, pp. 19-25, DOI: http://dx.doi.org/10.14429/dsj.66.9201

  14. Jerk analysis in rail vehicle dynamics

    Directory of Open Access Journals (Sweden)

    Sunil Kumar Sharma

    2016-09-01

    Full Text Available The acceleration and deceleration of trains are essential for satisfactory performance of train services and for effective utilisation of line capacity by railways for a given network. However, it increases the risk of unbalancing the passengers. Therefore, in this paper, the jerk was analysed in the vehicle in order to examine its effect on safety and comfort to the passengers. For the purpose of this analysis, a rake with 24 ICF coaches fitted with CBC (H type tight lock and low preload draft gear hauled by WDP4 locomotive was considered. It was modelled using Universal Mechanism – a multibody dynamic software. Also, in addition, the vehicle is considered to be subjected to external forces such as rolling resistance, longitudinal wheel resistance, and gravitational force. The tractive and braking efforts for the locomotives are also considered with realistic track conditions between Lucknow and Kanpur of India. The presented results suggest that the CBC with balanced type draft gear reduces the jerk in the train.

  15. Environmental assessment for the electric and hybrid vehicle demonstration project, performance standards and financial incentives

    Energy Technology Data Exchange (ETDEWEB)

    LaBelle, S. J.

    1978-10-01

    The assessment is concerned with the impacts of the demonstration of electric and hybrid vehicles acquired to fulfill certain requirements of the Electric and Hybrid Vehicle Research, Development, and Demonstration Act, PL 94-413 as amended. The financial incentives programs and vehicle performance standards associated with the demonstration are also covered. Not included is an assessment of the long term effects of EHV commercialization and of the research and development program being carried out simultaneously with the demonstration, also in response to PL 94-413. These federal actions will be included in a programmatic environmental assessment scheduled for completion in FY 79.

  16. Optimum Design of 1st Gear Ratio for 4WD Vehicles Based on Vehicle Dynamic Behaviour

    OpenAIRE

    M. H. Shojaeefard; Talebitooti,R.; Sadegh Yarmohammadi Satri

    2013-01-01

    This paper presents an approach that allows optimizing gear ratio and vehicle dimension to achieve optimum gear transmission. Therefore, augmented Lagrangian multiplier method, defined as classical method, is utilized to find the optimum gear ratios and the corresponding number of gear teeth applied to all epicyclical gears. The new method is able to calculate and also to optimize the gear ratio based on dynamics of 4WD vehicles. Therefore, 4WD vehicles dynamic equations are employed assuming...

  17. An analytical study of electric vehicle handling dynamics

    Science.gov (United States)

    Greene, J. E.; Segal, D. J.

    1979-01-01

    Hypothetical electric vehicle configurations were studied by applying available analytical methods. Elementary linearized models were used in addition to a highly sophisticated vehicle dynamics computer simulation technique. Physical properties of specific EV's were defined for various battery and powertrain packaging approaches applied to a range of weight distribution and inertial properties which characterize a generic class of EV's. Computer simulations of structured maneuvers were performed for predicting handling qualities in the normal driving range and during various extreme conditions related to accident avoidance. Results indicate that an EV with forward weight bias will possess handling qualities superior to a comparable EV that is rear-heavy or equally balanced. The importance of properly matching tires, suspension systems, and brake system front/rear torque proportioning to a given EV configuration during the design stage is demonstrated.

  18. Computational fluid dynamics challenges for hybrid air vehicle applications

    Science.gov (United States)

    Carrin, M.; Biava, M.; Steijl, R.; Barakos, G. N.; Stewart, D.

    2017-06-01

    This paper begins by comparing turbulence models for the prediction of hybrid air vehicle (HAV) flows. A 6 : 1 prolate spheroid is employed for validation of the computational fluid dynamics (CFD) method. An analysis of turbulent quantities is presented and the Shear Stress Transport (SST) k-ω model is compared against a k-ω Explicit Algebraic Stress model (EASM) within the unsteady Reynolds-Averaged Navier-Stokes (RANS) framework. Further comparisons involve Scale Adaptative Simulation models and a local transition transport model. The results show that the flow around the vehicle at low pitch angles is sensitive to transition effects. At high pitch angles, the vortices generated on the suction side provide substantial lift augmentation and are better resolved by EASMs. The validated CFD method is employed for the flow around a shape similar to the Airlander aircraft of Hybrid Air Vehicles Ltd. The sensitivity of the transition location to the Reynolds number is demonstrated and the role of each vehicle£s component is analyzed. It was found that the ¦ns contributed the most to increase the lift and drag.

  19. Effect of the Longitudinal Contact Location on Vehicle Dynamics Simulation

    NARCIS (Netherlands)

    Burgelman, N.; Li, Z.; Dollevoet, R.

    2016-01-01

    This paper investigates the effect of the calculation of the longitudinal location of a wheel rail contact point on the wheelset’s motion in a vehicle dynamic simulation. All current vehicle dynamic software programs assume that the contact between wheel and rail takes place in the vertical plane th

  20. Effect of the Longitudinal Contact Location on Vehicle Dynamics Simulation

    Directory of Open Access Journals (Sweden)

    N. Burgelman

    2016-01-01

    Full Text Available This paper investigates the effect of the calculation of the longitudinal location of a wheel rail contact point on the wheelset’s motion in a vehicle dynamic simulation. All current vehicle dynamic software programs assume that the contact between wheel and rail takes place in the vertical plane through the wheelset’s rolling axis. However, when the yaw angle of the wheelset is nonzero, the contact point is situated up to 10 mm from that plane. This difference causes a difference in the yaw moment on the wheelset which is used in the vehicle dynamic simulation. To such an end, an existing analytical method to determine the longitudinal method was validated using a numerical approach. Then vehicle dynamic simulations with both the classic and the new contact location were performed, concluding that using a more accurate contact point location results in a smaller wheelset yaw angle in a vehicle dynamic simulation, although the effect is small.

  1. Dynamics of Motorized Vehicle Flow under Mixed Traffic Circumstance*

    Institute of Scientific and Technical Information of China (English)

    GUO nong-Wei; GAO Zi-You; ZHAO Xiao-Mei; XIE Dong-Fan

    2011-01-01

    To study the dynamics of mixed traffic flow consisting of motorized and non-motorized vehicles, a carfollowing model based on the principle of collision free and cautious driving is proposed.Lateral friction and overlapping driving are introduced to describe the interactions between motorized vehicles and non-motorized vehicles.By numerical simulations, the flux-density relation, the temporal-spatial dynamics, and the velocity evolution are investigated in detail.The results indicate non-motorized vehicles have a significant impact on the motorized vehicle flow and cause the maximum flux to decline by about 13%.Non-motorized vehicles can decrease the motorized vehicle velocity and cause velocity oscillation when the motorized vehicle density is low.Moreover, non-motorized vehicles show a significant damping effect on the oscillating velocity when the density is medium and high, and such an effect weakens as motorized vehicle densityincreases.The results also stress the necessity for separating motorized vehicles from non-motorized vehicles.

  2. 2014 ITS World Congress Connected Vehicle Test Bed Demonstration Intersection Situation Data

    Data.gov (United States)

    Department of Transportation — During the 2014 ITS World Congress a demonstration of the connected vehicle infrastructure in the City of Detroit was conducted. The test site included approximately...

  3. 2014 ITS World Congress Connected Vehicle Test Bed Demonstration Traveler Situation Data

    Data.gov (United States)

    Department of Transportation — During the 2014 ITS World Congress a demonstration of the connected vehicle infrastructure in the City of Detroit was conducted. The test site included approximately...

  4. Dynamic response of a vehicle with planar suspension system (PSS) under differential braking

    Science.gov (United States)

    Zhu, Jian Jun; Khajepour, Amir; Esmailzadeh, Ebrahim

    2012-01-01

    To absorb the vibrations and shocks caused by road obstacles effectively in any direction within the wheel rotation plane, a planar suspension system (PSS), in which there are spring-damper struts in both the vertical and longitudinal directions, is proposed to improve the ride quality of a vehicle with such novel suspension systems. The longitudinal spring-damper strut in a PSS is considerably soft compared with the longitudinal connection in a conventional suspension. Consequently, the wheels in a vehicle with PSS can move forth and back with respect to the body. The dynamic behaviours of a PSS vehicle under some special conditions, such as a differential braking in which the braking torque applied to the wheels at two sides of an axle are uneven, may exhibit special characteristics. The directional stability of the PSS vehicle in such a case may be one of the major concerns. The dynamic performance of the PSS vehicle in the differential braking condition is thus necessary to be investigated. This paper presents the investigation results of the transient response of a vehicle with the PSS in such a case. The simulation results are also compared with those of a similar vehicle with conventional suspensions. The study demonstrates that the PSS vehicle is directionally stable in differential braking conditions. The dynamic behaviour of the PSS vehicle is generally comparable with that of a conventional vehicle.

  5. Research and Simulation of the Electrical Vehicle Based Dynamical System

    Directory of Open Access Journals (Sweden)

    Ko-Chun Chen

    2015-01-01

    Full Text Available This study developed a dynamic model of electric vehicle system by using the MATLAB/Simulink tool. The vehicle model comprises two system components: an electrical system and a suspension system. This study also designed various road conditions for simulating the motion of vehicle traveling along a road. The results show that the electrical and suspension system parameters can be adjusted immediately to enhance passenger comfort. The findings of this research have practical teaching applications. Students can modify the vehicle model parameters byes using the MATLAB graphical user interface, allowing them to observe the motion of vehicle under various road conditions.

  6. A review of dynamic characteristics of magnetically levitated vehicle systems

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Y.; Chen, S.S.

    1995-11-01

    The dynamic response of magnetically levitated (maglev) ground transportation systems has important consequences for safety and ride quality, guideway design, and system costs. Ride quality is determined by vehicle response and by environmental factors such as humidity and noise. The dynamic response of the vehicles is the key element in determining ride quality, while vehicle stability is an important safety-related element. To design a guideway that provides acceptable ride quality in the stable region, vehicle dynamics must be understood. Furthermore, the trade-off between guideway smoothness and levitation and control systems must be considered if maglev systems are to be economically feasible. The link between the guideway and the other maglev components is vehicle dynamics. For a commercial maglev system, vehicle dynamics must be analyzed and tested in detail. This report, which reviews various aspects of the dynamic characteristics, experiments and analysis, and design guidelines for maglev systems, discusses vehicle stability, motion dependent magnetic force components, guideway characteristics, vehicle/ guideway interaction, ride quality, suspension control laws, aerodynamic loads and other excitations, and research needs.

  7. Rotorcraft control system design for uncertain vehicle dynamics using quantitative feedback theory

    Science.gov (United States)

    Hess, R. A.

    1994-01-01

    Quantitative Feedback Theory describes a frequency-domain technique for the design of multi-input, multi-output control systems which must meet time or frequency domain performance criteria when specified uncertainty exists in the linear description of the vehicle dynamics. This theory is applied to the design of the longitudinal flight control system for a linear model of the BO-105C rotorcraft. Uncertainty in the vehicle model is due to the variation in the vehicle dynamics over a range of airspeeds from 0-100 kts. For purposes of exposition, the vehicle description contains no rotor or actuator dynamics. The design example indicates the manner in which significant uncertainty exists in the vehicle model. The advantage of using a sequential loop closure technique to reduce the cost of feedback is demonstrated by example.

  8. Extensions to the Dynamic Aerospace Vehicle Exchange Markup Language

    Science.gov (United States)

    Brian, Geoffrey J.; Jackson, E. Bruce

    2011-01-01

    The Dynamic Aerospace Vehicle Exchange Markup Language (DAVE-ML) is a syntactical language for exchanging flight vehicle dynamic model data. It provides a framework for encoding entire flight vehicle dynamic model data packages for exchange and/or long-term archiving. Version 2.0.1 of DAVE-ML provides much of the functionality envisioned for exchanging aerospace vehicle data; however, it is limited in only supporting scalar time-independent data. Additional functionality is required to support vector and matrix data, abstracting sub-system models, detailing dynamics system models (both discrete and continuous), and defining a dynamic data format (such as time sequenced data) for validation of dynamics system models and vehicle simulation packages. Extensions to DAVE-ML have been proposed to manage data as vectors and n-dimensional matrices, and record dynamic data in a compatible form. These capabilities will improve the clarity of data being exchanged, simplify the naming of parameters, and permit static and dynamic data to be stored using a common syntax within a single file; thereby enhancing the framework provided by DAVE-ML for exchanging entire flight vehicle dynamic simulation models.

  9. Reliable dynamic in-vehicle navigation

    OpenAIRE

    Kaparias, I.

    2008-01-01

    Having started off from luxury makes and models, in-vehicle navigation systems are now gradually spreading through the entire vehicle fleet, as drivers appreciate their usefulness. Increasingly sophisticated systems are being developed, having much more advanced functions than simple driving directions. This thesis presents a new approach for in-vehicle navigation, in which travel time reliability is incorporated in the route finding component of the navigation system. Based on historical tra...

  10. U.S. Department of Energy -- Advanced Vehicle Testing Activity: Plug-in Hybrid Electric Vehicle Testing and Demonstration Activities

    Energy Technology Data Exchange (ETDEWEB)

    James E. Francfort; Donald Karner; John G. Smart

    2009-05-01

    The U.S. Department of Energy’s (DOE) Advanced Vehicle Testing Activity (AVTA) tests plug-in hybrid electric vehicles (PHEV) in closed track, dynamometer and onroad testing environments. The onroad testing includes the use of dedicated drivers on repeated urban and highway driving cycles that range from 10 to 200 miles, with recharging between each loop. Fleet demonstrations with onboard data collectors are also ongoing with PHEVs operating in several dozen states and Canadian Provinces, during which trips- and miles-per-charge, charging demand and energy profiles, and miles-per-gallon and miles-per-kilowatt-hour fuel use results are all documented, allowing an understanding of fuel use when vehicles are operated in charge depleting, charge sustaining, and mixed charge modes. The intent of the PHEV testing includes documenting the petroleum reduction potential of the PHEV concept, the infrastructure requirements, and operator recharging influences and profiles. As of May 2008, the AVTA has conducted track and dynamometer testing on six PHEV conversion models and fleet testing on 70 PHEVs representing nine PHEV conversion models. A total of 150 PHEVs will be in fleet testing by the end of 2008, all with onboard data loggers. The onroad testing to date has demonstrated 100+ miles per gallon results in mostly urban applications for approximately the first 40 miles of PHEV operations. The primary goal of the AVTA is to provide advanced technology vehicle performance benchmark data for technology modelers, research and development programs, and technology goal setters. The AVTA testing results also assist fleet managers in making informed vehicle purchase, deployment and operating decisions. The AVTA is part of DOE’s Vehicle Technologies Program. These AVTA testing activities are conducted by the Idaho National Laboratory and Electric Transportation Engineering Corporation, with Argonne National Laboratory providing dynamometer testing support. The proposed paper

  11. Analysis of vehicle dynamics under sadden cross wind

    Science.gov (United States)

    Walczak, S.

    2016-09-01

    In this paper, the way of calculating aerodynamic forces acting on a vehicle passing in the region of sadden cross wind was presented. The CarDyn, a vehicle dynamics simulation program, developed by the author was used. The effects of the cross wind were studied with a fixed steering wheel simulation. On the base of computer simulations the car cross wind sensitivity were determined, and vehicle responses such as lateral offset, side acceleration and yaw angular velocity are presented.

  12. Decomposing the dynamics of heterogeneous delayed networks with applications to connected vehicle systems.

    Science.gov (United States)

    Szalai, Róbert; Orosz, Gábor

    2013-10-01

    Delay-coupled networks are investigated with nonidentical delay times and the effects of such heterogeneity on the emergent dynamics of complex systems are characterized. A simple decomposition method is presented that decouples the dynamics of the network into node-size modal equations in the vicinity of equilibria. The resulting independent components contain distributed delays that map the spatiotemporal complexity of the system to the time domain. We demonstrate that this approach can be used to reveal physical phenomena in heterogenous vehicular traffic when vehicles are linked via vehicle-to-vehicle communication.

  13. TIRE MODELS USED IN VEHICLE DYNAMIC APPLICATIONS AND THEIR USING IN VEHICLE ACCIDENT SIMULATIONS

    Directory of Open Access Journals (Sweden)

    Osman ELDOĞAN

    1995-01-01

    Full Text Available Wheel model is very important in vehicle modelling, it is because the contact between vehicle and road is achieved by wheel. Vehicle models can be dynamic models which are used in vehicle design, they can also be models used in accident simulations. Because of the importance of subject, many studies including theoretical, experimental and mixed type have been carried out. In this study, information is given about development of wheel modelling and research studies and also use of these modellings in traffic accident simulations.

  14. Dynamic vehicle routing with time windows in theory and practice

    NARCIS (Netherlands)

    Yang, Z.; Osta, van J.P.; Veen, van B.; Krevelen, van R.; Stam, A.; Kok, J.N.; Bäck, T.H.W.; Michael, Emmerich T. M.

    2016-01-01

    The vehicle routing problem is a classical combinatorial optimization problem. This work is about a variant of the vehicle routing problem with dynamically changing orders and time windows. In real-world applications often the demands change during operation time. New orders occur and others are

  15. Dynamic vehicle routing with time windows in theory and practice

    NARCIS (Netherlands)

    Yang, Z.; Osta, van J.P.; Veen, van B.; Krevelen, van R.; Stam, A.; Kok, J.N.; Bäck, T.H.W.; Michael, Emmerich T. M.

    2016-01-01

    The vehicle routing problem is a classical combinatorial optimization problem. This work is about a variant of the vehicle routing problem with dynamically changing orders and time windows. In real-world applications often the demands change during operation time. New orders occur and others are can

  16. Vehicle dynamic effects in the course of passing over turnouts

    Directory of Open Access Journals (Sweden)

    Zelenka J.

    2007-11-01

    Full Text Available For the quantification of vehicle dynamic effects at passing over turnouts at a higher speed there was developed a methodology for evaluating of acceleration measured on vehicle axle boxes in the year 2003. The methodology is based on statistical evaluation of lateral and vertical acceleration measured values at passing over both critical parts of a turnout (tongue, frog. The created methodology was used for investigation of vehicle dynamic effects by running at speed up to 230 km/h in the year 2004 in terms of high speed tests of tilting-body unit class 680 CD. There was found relatively high values of dynamic effects already at a speed 160 km/h. In terms of tilting-body unit class 680 tests at a higher speed in curves of chosen track lines of 1st and 2nd corridor of Czech Railways there was carried out also verification of curved turnouts state according to methodology mentioned above with a view to possibility of speed increasing at curved throats of chosen stations. Lateral vehicle dynamic effects at passing over a curved turnout frog area were evaluated. There were carried out simulation calculations of vehicle passing over a turnout based on measured geometric parameters of wheelset as well as chosen turnouts. Results of the calculations were compared with measurements. The increased vehicle dynamic effects found in pulsed beats character influence negatively the turnouts part (not only wheel contacting parts as well as operating life all unsuspended parts of vehicles.

  17. Optimum Design of 1st Gear Ratio for 4WD Vehicles Based on Vehicle Dynamic Behaviour

    Directory of Open Access Journals (Sweden)

    M. H. Shojaeefard

    2013-01-01

    Full Text Available This paper presents an approach that allows optimizing gear ratio and vehicle dimension to achieve optimum gear transmission. Therefore, augmented Lagrangian multiplier method, defined as classical method, is utilized to find the optimum gear ratios and the corresponding number of gear teeth applied to all epicyclical gears. The new method is able to calculate and also to optimize the gear ratio based on dynamics of 4WD vehicles. Therefore, 4WD vehicles dynamic equations are employed assuming that the rear wheels or the front wheels are at the point of slip. In addition, a genetic algorithm is modified to preserve feasibility of the encountered solutions. The basic dimension of a sample commercial vehicle (2009 hummer H3 4dr AWD SUV and its gearbox are optimized, and then the effects of changing slip angle, wheel base, and engine torque on optimum vehicle dimension are analyzed.

  18. Modelling and analysis of the dynamics of a tilting three-wheeled vehicle

    Energy Technology Data Exchange (ETDEWEB)

    Edelmann, Johannes, E-mail: johannes.edelmann@tuwien.ac.at; Ploechl, Manfred, E-mail: manfred.ploechl@tuwien.ac.at; Lugner, Peter, E-mail: peter.lugner@tuwien.ac.at [Vienna University of Technology, Vehicle System Dynamics and Biomechanics, Institute of Mechanics and Mechatronics (Austria)

    2011-12-15

    To understand the handling behaviour of a three-wheeled tilting vehicle, models of the vehicle with different level of detail, corresponding to specific fields of investigation, have been developed. Then the proposed kinematics of the three-wheeler are assessed and optimized with respect to desired dynamic properties by applying a detailed multibody system model. The partially unstable nature of the motion of the vehicle suggests the application of an analytically derived, simplified model, to allow for focusing on stability aspects and steady-state handling properties. These investigations reveal the necessity of employing a steer-by-wire control system to support the driver by stabilizing the motion of the vehicle. Thus, an additional basic vehicle model is derived for control design, and an energy-efficient control strategy is presented. Numerical simulation results demonstrate the dynamic properties of the optimized kinematics and the control system, approved by successful test runs of a prototype.

  19. Dynamic Performance of Subway Vehicle with Linear Induction Motor System

    Science.gov (United States)

    Wu, Pingbo; Luo, Ren; Hu, Yan; Zeng, Jing

    The light rail vehicle with Linear Induction Motor (LIM) bogie, which is a new type of urban rail traffic tool, has the advantages of low costs, wide applicability, low noise, simple maintenance and better dynamic behavior. This kind of vehicle, supported and guided by the wheel and rail, is not driven by the wheel/rail adhesion force, but driven by the electromagnetic force between LIM and reaction plate. In this paper, three different types of suspensions and their characteristic are discussed with considering the interactions both between wheel and rail and between LIM and reaction plate. A nonlinear mathematical model of the vehicle with LIM bogie is set up by using the software SIMPACK, and the electromechanical model is also set up on Simulink roof. Then the running behavior of the LIM vehicle is simulated, and the influence of suspension on the vehicle dynamic performance is investigated.

  20. Observable dynamics and coordinate systems for vehicle tracking

    CERN Document Server

    Altendorfer, Richard

    2010-01-01

    We investigate several coordinate systems and dynamical vector fields for target tracking to be used in driver assistance systems. We show how to express the discrete dynamics of maneuvering target vehicles in arbitrary coordinates starting from the target's and the own (ego) vehicle's assumed dynamical model in global coordinates. We clarify the notion of "ego compensation" and show how non-inertial effects are to be included when using a body-fixed coordinate system for target tracking. We finally compare the tracking error of different combinations of target tracking coordinates and dynamical vector fields for simulated data.

  1. Dynamic Data Driven Methods for Self-aware Aerospace Vehicles

    Science.gov (United States)

    2015-04-08

    AFRL-OSR-VA-TR-2015-0127 Dynamic Data Driven Methods for Self-aware Aerospace Vehicles Karen Willcox MASSACHUSETTS INSTITUTE OF TECHNOLOGY Final...Methods for Self-aware Aerospace Vehicles 5a. CONTRACT NUMBER 5b. GRANT NUMBER FA9550-11-1-0339 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Karen E...Back (Rev. 8/98) Dynamic Data Driven Methods for Self-aware Aerospace Vehicles Grant # FA9550-11-1-0339 Final Report Participating Institutions

  2. Alternative fuels for vehicles fleet demonstration program final report. Volume 1: Summary

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    The Alternative Fuels for Vehicles Fleet Demonstration Program (AFV-FDP) was a multiyear effort to collect technical data for use in determining the costs and benefits of alternative-fuel vehicles in typical applications in New York State. During 3 years of collecting data, 7.3 million miles of driving were accumulated, 1,003 chassis-dynamometer emissions tests were performed, 862,000 gallons of conventional fuel were saved, and unique information was developed about garage safety recommendations, vehicle performance, and other topics. Findings are organized by vehicle and fuel type. For light-duty compressed natural gas (CNG) vehicles, technology has evolved rapidly and closed-loop, electronically-controlled fuel systems provide performance and emissions advantages over open-loop, mechanical systems. The best CNG technology produces consistently low tailpipe emissions versus gasoline, and can eliminate evaporative emissions. Reduced driving range remains the largest physical drawback. Fuel cost is low ($/Btu) but capital costs are high, indicating that economics are best with vehicles that are used intensively. Propane produces impacts similar to CNG and is less expensive to implement, but fuel cost is higher than gasoline and safety codes limit use in urban areas. Light-duty methanol/ethanol vehicles provide performance and emissions benefits over gasoline with little impact on capital costs, but fuel costs are high. Heavy-duty CNG engines are evolving rapidly and provide large reductions in emissions versus diesel. Capital costs are high for CNG buses and fuel efficiency is reduced, but the fuel is less expensive and overall operating costs are about equal to those of diesel buses. Methanol buses provide performance and emissions benefits versus diesel, but fuel costs are high. Other emerging technologies were also evaluated, including electric vehicles, hybrid-electric vehicles, and fuel cells.

  3. Partially dynamic vehicle routing - models and algorithms

    DEFF Research Database (Denmark)

    Larsen, Allan; Madsen, Oli B.G.; Solomon, M.

    2002-01-01

    In this paper we propose a framework for dynamic routing systems based on their degree of dynamism. Next, we consider its impact on solution methodology and quality. Specifically, we introduce the Partially Dynamic Travelling Repairman Problem and describe several dynamic policies to minimize rou...

  4. Aeromechanics and Vehicle Configuration Demonstrations. Volume 2: Understanding Vehicle Sizing, Aeromechanics and Configuration Trades, Risks, and Issues for Next-Generations Access to Space Vehicles

    Science.gov (United States)

    2014-01-01

    design emphasizes individual components of the vehicle such as ribs or fuel tanks . Each component is sized to meet its expected requirements and...computational fluid dynamics ( CFD ) simulations that capture, to varying degrees, viscous effects. Different approaches make different simplifying...force, but a complex result like the center of pressure on a body will highlight any inaccuracies of lower- fidelity tools.[129] The center of

  5. Integrated and Dynamic Vehicle and Crew Scheduling

    NARCIS (Netherlands)

    D. Huisman (Dennis)

    2004-01-01

    textabstractDue to increased competition in the public transport market and the pressure on governments to cut expenses, increasing attention has been paid to cost reductions in public transportation. Since the main resources used in public transportation are vehicles and crews, producing efficient

  6. On the problems of non-smooth railway vehicle dynamics

    DEFF Research Database (Denmark)

    Thomsen, Per Grove; True, Hans

    2005-01-01

    Railway vehicle dynamics is inherently a problem of nonlinear dynamics. The unavoidable nonlinearities stem from the rail/wheel contact geometry and the stress/strain velocity relation in the rail/wheel contact surface. In addition motion delimiters and dry friction contact between elements...

  7. A Study of Maglev Vehicle Dynamics Using a Reduced-Scale Vehicle Model Experiment Apparatus

    Science.gov (United States)

    Suzuki, Erimitsu; Watanabe, Ken; Hoshino, Hironori; Yonezu, Takenori; Nagai, Masao

    An experiment apparatus using a 1/12 scale model of a train car body was constructed to study the characteristics of vehicle dynamics of magnetically levitated high speed surface transport (Maglev) systems that differ from conventional railway systems. Consisting of six-axis parallel link motion bases to reproduce bogie motions, an aluminum car body, and secondary suspension units, this apparatus is expected to be useful in examinations of control methods to reduce vehicle vibrations and to generate data useful in eventually improving the precision of computer simulations. This report provides an overview of the Maglev vehicle model experiment apparatus and results of initial tests examining its fundamental characteristics.

  8. Optimal Charging of Electric Drive Vehicles: A Dynamic Programming Approach

    DEFF Research Database (Denmark)

    Delikaraoglou, Stefanos; Capion, Karsten Emil; Juul, Nina

    2013-01-01

    of electric vehicles in a market environment. From the perspective of vehicle operators participating in the electricity spot market, the problem is to optimally charge and discharge the vehicles in response to spot market prices. We consider the case of a vehicle owner who is a price......With the integration of fluctuating renewable production into the electricity system, electric-drive vehicles may contribute to the resulting need for flexibility, given that the market conditions provide sufficient economic incentive. To investigate this, we consider the short-term management......-taker and that of a fleet operator who can influence prices. In both cases, we show how the problem is amenable to dynamic programming with respectively linear and quadratic costs. With discretization of the state space, however, the problem of fleet operation is prone to suffer from the curse of dimensionality and...

  9. Structural dynamic and aeroelastic considerations for hypersonic vehicles

    Science.gov (United States)

    Cazier, F. W., Jr.; Doggett, Robert V., Jr.; Ricketts, Rodney H.

    1991-01-01

    The specific geometrical, structural, and operational environment characteristics of hypersonic vehicles are discussed with particular reference to aerospace plane type configurations. A discussion of the structural dynamic and aeroelastic phenomena that must be addressed for this class of vehicles is presented. These phenomena are in the aeroservothermoelasticity technical area. Some illustrative examples of recent experimental and analytical work are given. Some examples of current research are pointed out.

  10. Nonlinear Dynamic Analysis of the Whole Vehicle on Bumpy Road

    Institute of Scientific and Technical Information of China (English)

    王威; 李瑰贤; 宋玉玲

    2010-01-01

    Through the research into the characteristics of 7-DoF high dimensional nonlinear dynamics of a vehicle on bumpy road, the periodic movement and chaotic behavior of the vehicle were found.The methods of nonlinear frequency response analysis, global bifurcation, frequency chart and Poincaré maps were used simultaneously to derive strange super chaotic attractor.According to Lyapunov exponents calculated by Gram-Schmidt method, the unstable region was compartmentalized and the super chaotic characteristic of ...

  11. Electric Vehicle Smart Charging using Dynamic Price Signal

    DEFF Research Database (Denmark)

    Martinenas, Sergejus; Pedersen, Anders Bro; Marinelli, Mattia

    2014-01-01

    With yearly increases in Electric Vehicle (EV) sales, the future for electric mobility continues to brighten, and with more vehicles hitting the roads every day, the energy requirements on the grid will increase, potentially causing low-voltage distribution grid congestion. This problem can...... proposed in this paper, involves a real-time control strategy for charging the EV using a dynamic price tariff, with the objective of minimizing the charging cost. Two different charging scenario are investigated, and the results are verified by experiments on a real Electric Vehicle. Finally, the costs...

  12. SOFTWARE TESTING OF THE RAIL VEHICLE DYNAMIC CHARACTERISTICS

    Directory of Open Access Journals (Sweden)

    Sanjin Troha

    2015-08-01

    Full Text Available The modern construction concept and the determination of the machine system characteristics anticipate CAD design. Creating model that will be tested using FEM and other methods for determining stress-strain is a very important part of rail vehicle construction. Applicative software package consists of linear and non–linear methods for the prediction of railway vehicle behavior and various methods of analysis have been assembled into a single coherent package in order to allow real problems in railway vehicle dynamics to be solved.

  13. On the Theory of Nonlinear Dynamics and its Applications in Vehicle Systems Dynamics

    DEFF Research Database (Denmark)

    True, Hans

    1999-01-01

    We present a brief outline of nonlinear dynamics and its applications to vehicle systems dynamics problems. The concept of a phase space is introduced in order to illustrate the dynamics of nonlinear systems in a way that is easy to perceive. Various equilibrium states are defined...... of nonlinear dynamics in vehicle simulations is discussed, and it is argued that it is necessary to know the equilibrium states of the full nonlinear system before the simulation calculations are performed....

  14. Study on modeling of vehicle dynamic stability and control technique

    Institute of Scientific and Technical Information of China (English)

    GAO Yun-ting; LI Pan-feng

    2012-01-01

    In order to solve the problem of enhancing the vehicle driving stability and safety,which has been the hot question researched by scientific and engineering in the vehicle industry,the new control method was investigated.After the analysis of tire moving characteristics and the vehicle stress analysis,the tire model based on the extension pacejka magic formula which combined longitudinal motion and lateral motion was developed and a nonlinear vehicle dynamical stability model with seven freedoms was made.A new model reference adaptive control project which made the slip angle and yaw rate of vehicle body as the output and feedback variable in adjusting the torque of vehicle body to control the vehicle stability was designed.A simulation model was also built in Matlab/Simulink to evaluate this control project.It was made up of many mathematical subsystem models mainly including the tire model module,the yaw moment calculation module,the center of mass parameter calculation module,tire parameter calculation module of multiple and so forth.The severe lane change simulation result shows that this vehicle model and the model reference adaptive control method have an excellent performance.

  15. Alternative fuels for vehicles fleet demonstration program. Final report, volume 2: Appendices

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-06-01

    The Alternative Fuels for Vehicles Fleet Demonstration Program (AFV-FDP) was a multiyear effort to collect technical data for use in determining the costs and benefits of alternative-fuel vehicles (AFVs) in typical applications in New York State. This report, Volume 2, includes 13 appendices to Volume 1 that expand upon issues raised therein. Volume 1 provides: (1) Information about the purpose and scope of the AFV-FDP; (2) A summary of AFV-FDP findings organized on the basis of vehicle type and fuel type; (3) A short review of the status of AFV technology development, including examples of companies in the State that are active in developing AFVs and AFV components; and (4) A brief overview of the status of AFV deployment in the State. Volume 3 provides expanded reporting of AFV-FDP technical details, including the complete texts of the brochure Garage Guidelines for Alternative Fuels and the technical report Fleet Experience Survey Report, plus an extensive glossary of AFV terminology. The appendices cover a wide range of issues including: emissions regulations in New York State; production and health effects of ozone; vehicle emissions and control systems; emissions from heavy-duty engines; reformulated gasoline; greenhouse gases; production and characteristics of alternative fuels; the Energy Policy Act of 1992; the Clean Fuel Fleet Program; garage design guidelines for alternative fuels; surveys of fleet managers using alternative fuels; taxes on conventional and alternative fuels; and zero-emission vehicle technology.

  16. Nonlinear dynamics modeling and simulation of two-wheeled self-balancing vehicle

    Directory of Open Access Journals (Sweden)

    Yunping Liu

    2016-11-01

    Full Text Available Two-wheeled self-balancing vehicle system is a kind of naturally unstable underactuated system with high-rank unstable multivariable strongly coupling complicated dynamic nonlinear property. Nonlinear dynamics modeling and simulation, as a basis of two-wheeled self-balancing vehicle dynamics research, has the guiding effect for system design of the project demonstration and design phase. Dynamics model of the two-wheeled self-balancing vehicle is established by importing a TSi ProPac package to the Mathematica software (version 8.0, which analyzes the stability and calculates the Lyapunov exponents of the system. The relationship between external force and stability of the system is analyzed by the phase trajectory. Proportional–integral–derivative control is added to the system in order to improve the stability of the two-wheeled self-balancing vehicle. From the research, Lyapunov exponent can be used to research the stability of hyperchaos system. The stability of the two-wheeled self-balancing vehicle is better by inputting the proportional–integral–derivative control. The Lyapunov exponent and phase trajectory can help us analyze the stability of a system better and lay the foundation for the analysis and control of the two-wheeled self-balancing vehicle system.

  17. Total dynamic response of a PSS vehicle negotiating asymmetric road excitations

    Science.gov (United States)

    Zhu, Jian Jun; Khajepour, Amir; Esmailzadeh, Ebrahim

    2012-12-01

    A planar suspension system (PSS) is a novel automobile suspension system in which an individual spring-damper strut is implemented in both the vertical and longitudinal directions, respectively. The wheels in a vehicle with such a suspension system can move back and forth relative to the chassis. When a PSS vehicle experiences asymmetric road excitations, the relative longitudinal motion of wheels with respect to the chassis in two sides of the same axle are not identical, and thus the two wheels at one axle will not be aligned in the same axis. The total dynamic responses, including those of the bounce, pitch and the roll of the PSS vehicle, to the asymmetric road excitation may exhibit different characteristics from those of a conventional vehicle. This paper presents an investigation into the comprehensive dynamic behaviour of a vehicle with the PSS, in such a road condition, on both the straight and curved roads. The study was carried out using an 18 DOF full-car model incorporating a radial-spring tyre-ground contact model and a 2D tyre-ground dynamic friction model. Results demonstrate that the total dynamic behaviour of a PSS vehicle is generally comparable with that of the conventional vehicle, while PSS exhibits significant improvement in absorbing the impact forces along the longitudinal direction when compared to the conventional suspension system. The PSS vehicle is found to be more stable than the conventional vehicle in terms of the directional performance against the disturbance of the road potholes on a straight line manoeuvre, while exhibiting a very similar handling performance on a curved line.

  18. Dynamic vehicle routing problems: Three decades and counting

    DEFF Research Database (Denmark)

    Psaraftis, Harilaos N.; Wen, Min; Kontovas, Christos A.

    2016-01-01

    Since the late 70s, much research activity has taken place on the class of dynamic vehicle routing problems (DVRP), with the time period after year 2000 witnessing a real explosion in related papers. Our paper sheds more light into work in this area over more than 3 decades by developing a taxonomy...... of DVRP papers according to 11 criteria. These are (1) type of problem, (2) logistical context, (3) transportation mode, (4) objective function, (5) fleet size, (6) time constraints, (7) vehicle capacity constraints, (8) the ability to reject customers, (9) the nature of the dynamic element, (10...

  19. Structural dynamics for new launch vehicles

    Science.gov (United States)

    Neighbors, Joyce; Ryan, Robert S.

    1992-01-01

    An overview is presented of current studies that will permit more robust designs and reduce the safety hazards of maximum dynamic pressure during launches. Key considerations in the assessment of future operable launch capabilities are the dynamics problems that arise during the initial minutes of transition from the static configuration on the launch pad to the attainment of orbital velocity. Attention is given to a typical attempt to achieve robustness that involves creating a design in which the first bending mode will have a high enough frequency to allow decoupling between the autopilot design and the flexible body dynamics.

  20. Nonlinear Analysis and Intelligent Control of Integrated Vehicle Dynamics

    Directory of Open Access Journals (Sweden)

    C. Huang

    2014-01-01

    Full Text Available With increasing and more stringent requirements for advanced vehicle integration, including vehicle dynamics and control, traditional control and optimization strategies may not qualify for many applications. This is because, among other factors, they do not consider the nonlinear characteristics of practical systems. Moreover, the vehicle wheel model has some inadequacies regarding the sideslip angle, road adhesion coefficient, vertical load, and velocity. In this paper, an adaptive neural wheel network is introduced, and the interaction between the lateral and vertical dynamics of the vehicle is analyzed. By means of nonlinear analyses such as the use of a bifurcation diagram and the Lyapunov exponent, the vehicle is shown to exhibit complicated motions with increasing forward speed. Furthermore, electric power steering (EPS and active suspension system (ASS, which are based on intelligent control, are used to reduce the nonlinear effect, and a negotiation algorithm is designed to manage the interdependences and conflicts among handling stability, driving smoothness, and safety. Further, a rapid control prototype was built using the hardware-in-the-loop simulation platform dSPACE and used to conduct a real vehicle test. The results of the test were consistent with those of the simulation, thereby validating the proposed control.

  1. Direct start - from model to demo vehicle; Der Direktstart - Vom Modell zum Demonstrator

    Energy Technology Data Exchange (ETDEWEB)

    Kulzer, A.; Laubender, J.; Moessner, D.; Sieber, U. [Robert Bosch GmbH, Schwieberdingen (Germany); Lauff, U. [Etas GmbH (Germany)

    2006-09-15

    To start an engine with the use of nothing but combustion energy - the realization of this notion comprised the main theme of a project at the corporate sector research and advance engineering of Robert Bosch GmbH. With thermodynamic investigations as a starting point, Etas tools provided the power needed to demonstrate and analyse several different starting modes within a short period of time in a vehicle. (orig.)

  2. Recent advances in the fundamental understanding of railway vehicle dynamics

    DEFF Research Database (Denmark)

    True, Hans

    2006-01-01

    The topic of this article is the calculation of the critical speed for railway vehicles. It is emphasised that it is misleading to formulate the mathematical problem as a stability problem. It must correctly be formulated as a problem of existence of coexisting solutions to the full non-linear dy......The topic of this article is the calculation of the critical speed for railway vehicles. It is emphasised that it is misleading to formulate the mathematical problem as a stability problem. It must correctly be formulated as a problem of existence of coexisting solutions to the full non......-linear dynamical problem. The lowest speed at which there exist more critical speed in road tests. A couple of examples show applications of the method to various dynamical models of railway vehicles. Freight wagons are treated in the end of the article because the dry friction damping with stick-slip and end...

  3. Decoupling Control of Lateral Dynamics for 4WS Vehicle

    Institute of Scientific and Technical Information of China (English)

    刘奋; 张建武; 屈求真

    2003-01-01

    An four wheel steering (4WS)feedback contrlol system that simultanelusly achieves both body sideslip angle and yaw rate responses always desirable regardless of changes in vehicle dynamics.Quantitative feedback theory (QFT)is offered as the main tool for designing the control law.Inverted decoupling is also employed to make multivariable quantitative feedback design easier.Varilus nonlinear analyses are carried ut and show that the proposed comtrol system is a robust decoupling controller which not only makesd body sideslip angle and yaw rate of the vehicle track the desired reference input sigmals respectively,byt also satisfies the rrequirement of robustness for the control system.The results also indicate that the contral system can make it available to realize ideal lateral steering dynamics tracking for vehicles.

  4. TYRE DYNAMICS MODELLING OF VEHICLE BASED ON SUPPORT VECTOR MACHINES

    Institute of Scientific and Technical Information of China (English)

    ZHENG Shuibo; TANG Houjun; HAN Zhengzhi; ZHANG Yong

    2006-01-01

    Various methods of tyre modelling are implemented from pure theoretical to empirical or semi-empirical models based on experimental results. A new way of representing tyre data obtained from measurements is presented via support vector machines (SVMs). The feasibility of applying SVMs to steady-state tyre modelling is investigated by comparison with three-layer backpropagation(BP) neural network at pure slip and combined slip. The results indicate SVMs outperform the BP neural network in modelling the tyre characteristics with better generalization performance. The SVMs-tyre is implemented in 8-DOF vehicle model for vehicle dynamics simulation by means of the PAC 2002 Magic Formula as reference. The SVMs-tyre can be a competitive and accurate method to model a tyre for vehicle dynamics simulation.

  5. Dynamic Vehicle Routing for Robotic Networks: Models, Fundamental Limitations and Algorithms

    Science.gov (United States)

    2010-04-16

    partitions. SIAM Review, January 2010. Submitted Francesco Bullo (UCSB) Dynamic Vehicle Routing 16apr10 @ ARL 31 / 34 Gossip partitioning policy: sample...Control Conference, Hollywood, CA, October 2009 Francesco Bullo (UCSB) Dynamic Vehicle Routing 16apr10 @ ARL 32 / 34 Gossip partitioning policy: analysis...Dynamic Vehicle Routing for Robotic Networks: Models, Fundamental Limitations and Algorithms Francesco Bullo Center for Control, Dynamical Systems

  6. Integrated vehicle dynamics control using State Dependent Riccati Equations

    NARCIS (Netherlands)

    Bonsen, B.; Mansvelders, R.; Vermeer, E.

    2010-01-01

    In this paper we discuss a State Dependent Riccati Equations (SDRE) solution for Integrated Vehicle Dynamics Control (IVDC). The SDRE approach is a nonlinear variant of the well known Linear Quadratic Regulator (LQR) and implements a quadratic cost function optimization. A modified version of this

  7. Dynamic Vehicle Impact for Safety Assessment of Bridges

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Nielsen, Søren R. K.; Enevoldsen, I.

    In this paper the dynamic amplification of vehicle load at minor highway bridges is considered for safety assessment of the load carrying capacity of bridges. The considered case is the most critical for bridges, i.e. the simultaneous passage of two heavy trucks. A short description...

  8. Integrated vehicle dynamics control using State Dependent Riccati Equations

    NARCIS (Netherlands)

    Bonsen, B.; Mansvelders, R.; Vermeer, E.

    2010-01-01

    In this paper we discuss a State Dependent Riccati Equations (SDRE) solution for Integrated Vehicle Dynamics Control (IVDC). The SDRE approach is a nonlinear variant of the well known Linear Quadratic Regulator (LQR) and implements a quadratic cost function optimization. A modified version of this m

  9. Dynamic analysis and control of novel moving mass flight vehicle

    Science.gov (United States)

    Li, Jianqing; Gao, Changsheng; Jing, Wuxing; Wei, Pengxin

    2017-02-01

    In terms of the moving mass control technology, the configuration of internal moving masses is a key challenge. In order to reduce the complexity of configuring these moving masses in a flight vehicle, a combination bank-to-turn control mode with the single moving mass and reaction jet is proposed in this paper. To investigate the dynamics and the potential of the control mechanism, an attitude dynamic model with single moving mass is generated. The dynamic analysis indicates that the control stability, control authority and dynamic behavior of the pitch channel are determined by the mass ratio of the moving mass to the system and the difference between the mass center of the moving mass and the mass center of the vehicle body. Interestingly, control authority increases proportionally with increasing mass ratio and also with decreasing the magnitude of the static margin. To deal with the coupling caused by the additional inertia moment which is generated by the motion of the moving mass, an adaptive control law by using dynamic inversion theory and the extended state observer is designed. Also, a compensator is designed for eliminating the influence of the servo actuator's dynamics on attitude of the flight vehicle. Finally, the simulation results validate the quality of the proposed adaptive controller which ensures a good performance in the novel configuration with internal moving mass.

  10. A Dynamic Wideband Directional Channel Model for Vehicle-to-Vehicle Communications

    OpenAIRE

    He, Ruisi; Renaudin, Olivier; Kolmonen, Veli-Matti; Haneda, Katsuyuki; Zhong, Zhangdui; Ai, Bo; Oestges, Claude

    2015-01-01

    Vehicle-to-vehicle (V2V) communications have received a lot of attention due to their numerous applications in traffic safety. The design, testing, and improvement of the V2V system hinge critically on the understanding of the propagation channels. An important feature of the V2V channel is the time variance. To statistically model the time-variant V2V channels, a dynamic wideband directional channel model is proposed in this paper, based on measurements conducted at 5.3 GHz in suburban, urba...

  11. Land navigation Demonstration Vehicle with a color map display for tactical use

    Energy Technology Data Exchange (ETDEWEB)

    Nava, E.J.; Creel, E.E.; Fellerhoff, J.R.; Martinez, S.D.

    1986-01-01

    A Land navigation Demonstration Vehicle (LDV) has been assembled which fully automates the navigation task and provides the operator with a color map display derived from Digital Terrain Elevation Data (DTED). The system relieves the operator of the burdens associated with the tactical use of paper maps by providing accurate 3-dimensional position information using a strapdown inertial navigation platform aided by the Sandia Inertial Terrain Aided Navigation algorithm (SITAN). The map display and navigation instruments consist of a multi-processor SANDia Aerospace Computer (SANDAC) and a commercial Image Processing System (IPS). These interactive devices allow real-time map annotation and corrections of vehicle position errors. 7 refs., 9 figs., 1 tab.

  12. Dynamic motion stabilization for front-wheel drive in-wheel motor electric vehicles

    Directory of Open Access Journals (Sweden)

    Jia-Sheng Hu

    2015-12-01

    Full Text Available This article presents a new dynamic motion stabilization approach to front-wheel drive in-wheel motor electric vehicles. The approach includes functions such as traction control system, electronic differential system, and electronic stability control. The presented electric vehicle was endowed with anti-skid performance in longitudinal accelerated start; smooth turning with less tire scrubbing; and safe driving experience in two-dimensional steering. The analysis of the presented system is given in numerical derivations. For practical verifications, this article employed a hands-on electric vehicle named Corsa-electric vehicle to carry out the tests. The presented approach contains an integrated scheme which can achieve the mentioned functions in a single microprocessor. The experimental results demonstrated the effectiveness and feasibility of the presented methodology.

  13. Dynamic Surface Control and Its Application to Lateral Vehicle Control

    Directory of Open Access Journals (Sweden)

    Bongsob Song

    2014-01-01

    Full Text Available This paper extends the design and analysis methodology of dynamic surface control (DSC in Song and Hedrick, 2011, for a more general class of nonlinear systems. When rotational mechanical systems such as lateral vehicle control and robot control are considered for applications, sinusoidal functions are easily included in the equation of motions. If such a sinusoidal function is used as a forcing term for DSC, the stability analysis faces the difficulty due to highly nonlinear functions resulting from the low-pass filter dynamics. With modification of input variables to the filter dynamics, the burden of mathematical analysis can be reduced and stability conditions in linear matrix inequality form to guarantee the quadratic stability via DSC are derived for the given class of nonlinear systems. Finally, the proposed design and analysis approach are applied to lateral vehicle control for forward automated driving and backward parallel parking at a low speed as well as an illustrative example.

  14. Cone Algorithm of Spinning Vehicles under Dynamic Coning Environment

    Directory of Open Access Journals (Sweden)

    Shuang-biao Zhang

    2015-01-01

    Full Text Available Due to the fact that attitude error of vehicles has an intense trend of divergence when vehicles undergo worsening coning environment, in this paper, the model of dynamic coning environment is derived firstly. Then, through investigation of the effect on Euler attitude algorithm for the equivalency of traditional attitude algorithm, it is found that attitude error is actually the roll angle error including drifting error and oscillating error, which is induced directly by dynamic coning environment and further affects the pitch angle and yaw angle through transferring. Based on definition of the cone frame and cone attitude, a cone algorithm is proposed by rotation relationship to calculate cone attitude, and the relationship between cone attitude and Euler attitude of spinning vehicle is established. Through numerical simulations with different conditions of dynamic coning environment, it is shown that the induced error of Euler attitude fluctuates by the variation of precession and nutation, especially by that of nutation, and the oscillating frequency of roll angle error is twice that of pitch angle error and yaw angle error. In addition, the rotation angle is more competent to describe the spinning process of vehicles under coning environment than Euler angle gamma, and the real pitch angle and yaw angle are calculated finally.

  15. Optimization of hydrogen vehicle refueling via dynamic simulation

    DEFF Research Database (Denmark)

    Rothuizen, Erasmus Damgaard; Mérida, W.; Rokni, Masoud

    2013-01-01

    A dynamic model has been developed to analyze and optimize the thermodynamics and design of hydrogen refueling stations. The model is based on Dymola software and incorporates discrete components. Two refueling station designs were simulated and compared. The modeling results indicate that pressure...... loss in the vehicle's storage system is one of the main factors determining the mass flow and peak cooling requirements of the refueling process. The design of the refueling station does not influence the refueling of the vehicle when the requirements of the technical information report J2601 from...

  16. X-38 Prototype Technology Demonstrator for the Crew Return Vehicle (CRV) and Project Managers Bob Ba

    Science.gov (United States)

    1999-01-01

    Bob Baron of the Dryden Flight Research Center (left) and Brian Anderson of the Johnson Space Flight Center (right) flank an X-38 prototype Crew Return Vehicle technology demonstrator under construction at the Johnson Space Center, Houston, Texas. The X-38 Crew Return Vehicle (CRV) research project is designed to develop the technology for a prototype emergency crew return vehicle, or lifeboat, for the International Space Station. The project is also intended to develop a crew return vehicle design that could be modified for other uses, such as a joint U.S. and international human spacecraft that could be launched on the French Ariane-5 Booster. The X-38 project is using available technology and off-the-shelf equipment to significantly decrease development costs. Original estimates to develop a capsule-type crew return vehicle were estimated at more than $2 billion. X-38 project officials have estimated that development costs for the X-38 concept will be approximately one quarter of the original estimate. Off-the-shelf technology is not necessarily 'old' technology. Many of the technologies being used in the X-38 project have never before been applied to a human-flight spacecraft. For example, the X-38 flight computer is commercial equipment currently used in aircraft and the flight software operating system is a commercial system already in use in many aerospace applications. The video equipment for the X-38 is existing equipment, some of which has already flown on the space shuttle for previous NASA experiments. The X-38's primary navigational equipment, the Inertial Navigation System/Global Positioning System, is a unit already in use on Navy fighters. The X-38 electromechanical actuators come from previous joint NASA, U.S. Air Force, and U.S. Navy research and development projects. Finally, an existing special coating developed by NASA will be used on the X-38 thermal tiles to make them more durable than those used on the space shuttles. The X-38 itself was an

  17. On the problems of non-smooth railway vehicle dynamics

    DEFF Research Database (Denmark)

    Thomsen, Per Grove; True, Hans

    2005-01-01

    Railway vehicle dynamics is inherently a problem of nonlinear dynamics. The unavoidable nonlinearities stem from the rail/wheel contact geometry and the stress/strain velocity relation in the rail/wheel contact surface. In addition motion delimiters and dry friction contact between elements...... in the construction create discontinuities in the mathematical dynamic model. The stick/slip of dry friction can be modelled as a discontinuity or be smoothed whereby discontinuities of higher order spatial derivatives are introduced. Higher order discontinuities are also introduced through the rail/wheel contact...

  18. Simulation-Based Analysis of Reentry Dynamics for the Sharp Atmospheric Entry Vehicle

    Science.gov (United States)

    Tillier, Clemens Emmanuel

    1998-01-01

    This thesis describes the analysis of the reentry dynamics of a high-performance lifting atmospheric entry vehicle through numerical simulation tools. The vehicle, named SHARP, is currently being developed by the Thermal Protection Materials and Systems branch of NASA Ames Research Center, Moffett Field, California. The goal of this project is to provide insight into trajectory tradeoffs and vehicle dynamics using simulation tools that are powerful, flexible, user-friendly and inexpensive. Implemented Using MATLAB and SIMULINK, these tools are developed with an eye towards further use in the conceptual design of the SHARP vehicle's trajectory and flight control systems. A trajectory simulator is used to quantify the entry capabilities of the vehicle subject to various operational constraints. Using an aerodynamic database computed by NASA and a model of the earth, the simulator generates the vehicle trajectory in three-dimensional space based on aerodynamic angle inputs. Requirements for entry along the SHARP aerothermal performance constraint are evaluated for different control strategies. Effect of vehicle mass on entry parameters is investigated, and the cross range capability of the vehicle is evaluated. Trajectory results are presented and interpreted. A six degree of freedom simulator builds on the trajectory simulator and provides attitude simulation for future entry controls development. A Newtonian aerodynamic model including control surfaces and a mass model are developed. A visualization tool for interpreting simulation results is described. Control surfaces are roughly sized. A simple controller is developed to fly the vehicle along its aerothermal performance constraint using aerodynamic flaps for control. This end-to-end demonstration proves the suitability of the 6-DOF simulator for future flight control system development. Finally, issues surrounding real-time simulation with hardware in the loop are discussed.

  19. Liquid propellant analogy technique in dynamic modeling of launch vehicle

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The coupling effects among lateral mode,longitudinal mode and torsional mode of a launch vehicle cannot be taken into account in traditional dynamic analysis using lateral beam model and longitudinal spring-mass model individually.To deal with the problem,propellant analogy methods based on beam model are proposed and coupled mass-matrix of liquid propellant is constructed through additional mass in the present study.Then an integrated model of launch vehicle for free vibration analysis is established,by which research on the interactions between longitudinal and lateral modes,longitudinal and torsional modes of the launch vehicle can be implemented.Numerical examples for tandem tanks validate the present method and its necessity.

  20. MD1405: Demonstration of forced dynamic aperture measurements at injection

    CERN Document Server

    Carlier, Felix Simon; Persson, Tobias Hakan Bjorn; Tomas Garcia, Rogelio; CERN. Geneva. ATS Department

    2017-01-01

    Accurate measurements of dynamic aperture become more important for the LHC as it advances into increasingly nonlinear regimes of operations, as well as for the High Luminosity LHC where machine nonlinearities will have a significantly larger impact. Direct dynamic aperture measurements at top energy in the LHC are challenging, and conventional single kick methods are not viable. Dynamic aperture measurements under forced oscillation of AC dipoles have been proposed as s possible alternative observable. A first demonstration of forced DA measurements at injections energy is presented.

  1. Road and off-road vehicle system dynamics. Understanding the future from the past

    Science.gov (United States)

    Vantsevich, Vladimir V.

    2015-02-01

    A detailed analysis of scientific research directions and methods in ground vehicle dynamics and vehicle system dynamics during the past century is presented in this article. What started as peculiarities of vehicle motion, dynamics of vehicles went through extensive research and engineering work and was established as an applied science - vehicle dynamics. Steady motion and transient manoeuvres, multi-flexible-body dynamics, nonlinear and stochastic dynamics, terramechanics, vehicle operational properties and their multi-criterion optimisation, computer modelling and simulation, analysis and optimal synthesis, various controls, inverse vehicle dynamics, open architecture-type, and multi-domain vehicle systems - these are the milestones of developments over the past century. This article considers the subject-matter and the substance of vehicle dynamics in general, and new research directions of modern vehicle dynamics in particular. It is shown that modern vehicle dynamics is acquiring principally new features including agile dynamics of multi-physics mechatronic systems (including cyber-type systems), coupled and interactive vehicle system dynamics.

  2. Dynamic Vehicle Routing for Data Gathering in Wireless Networks

    CERN Document Server

    Çelik, Güner D

    2010-01-01

    We consider a dynamic vehicle routing problem in wireless networks where messages arriving randomly in time and space are collected by a mobile receiver (vehicle or a collector). The collector is responsible for receiving these messages via wireless communication by dynamically adjusting its position in the network. Our goal is to utilize a combination of wireless transmission and controlled mobility to improve the delay performance in such networks. We show that the necessary and sufficient condition for the stability of such a system (in the bounded average number of messages sense) is given by {\\rho}<1 where {\\rho} is the average system load. We derive fundamental lower bounds for the delay in the system and develop policies that are stable for all loads {\\rho}<1 and that have asymptotically optimal delay scaling. Furthermore, we extend our analysis to the case of multiple collectors in the network. We show that the combination of mobility and wireless transmission results in a delay scaling of {\\The...

  3. Cascaded adaptive control of ocean vehicles with significant actuator dynamics

    Directory of Open Access Journals (Sweden)

    Thor I. Fossen

    1994-04-01

    Full Text Available This paper presents a cascade adaptive control scheme for marine vehicles where the non-linear equations of motion include a model of the actuator dynamics. The adaptive controller does not require the parameters of the vehicle dynamics and the actuator time constants to be known a priori. Both the velocity and position tracking errors are shown to converge to zero by applying Barbalat's lemma. Global asymptotic stability is proven for the velocity scheme while the position/attitude controller is only proven to be convergent. Furthermore, all parameter estimates are shown to be bounded. Computer simulations of an ROV speed control system and an autopilot for automatic ship steering are used to illustrate the design methodology.

  4. A Monarch Butterfly Optimization for the Dynamic Vehicle Routing Problem

    Directory of Open Access Journals (Sweden)

    Shifeng Chen

    2017-09-01

    Full Text Available The dynamic vehicle routing problem (DVRP is a variant of the Vehicle Routing Problem (VRP in which customers appear dynamically. The objective is to determine a set of routes that minimizes the total travel distance. In this paper, we propose a monarch butterfly optimization (MBO algorithm to solve DVRPs, utilizing a greedy strategy. Both migration operation and the butterfly adjusting operator only accept the offspring of butterfly individuals that have better fitness than their parents. To improve performance, a later perturbation procedure is implemented, to maintain a balance between global diversification and local intensification. The computational results indicate that the proposed technique outperforms the existing approaches in the literature for average performance by at least 9.38%. In addition, 12 new best solutions were found. This shows that this proposed technique consistently produces high-quality solutions and outperforms other published heuristics for the DVRP.

  5. Dynamic vehicle routing problems: Three decades and counting

    DEFF Research Database (Denmark)

    Psaraftis, Harilaos N.; Wen, Min; Kontovas, Christos A.

    2016-01-01

    Since the late 70s, much research activity has taken place on the class of dynamic vehicle routing problems (DVRP), with the time period after year 2000 witnessing areal explosion in related papers. Our paper sheds more light into work in this area over more than 3 decades by developing a taxonomy...... linkages of methodology to technological advances and analysis of worst case or average case performance of heuristics....

  6. Dynamic vehicle routing with time windows in theory and practice.

    Science.gov (United States)

    Yang, Zhiwei; van Osta, Jan-Paul; van Veen, Barry; van Krevelen, Rick; van Klaveren, Richard; Stam, Andries; Kok, Joost; Bäck, Thomas; Emmerich, Michael

    2017-01-01

    The vehicle routing problem is a classical combinatorial optimization problem. This work is about a variant of the vehicle routing problem with dynamically changing orders and time windows. In real-world applications often the demands change during operation time. New orders occur and others are canceled. In this case new schedules need to be generated on-the-fly. Online optimization algorithms for dynamical vehicle routing address this problem but so far they do not consider time windows. Moreover, to match the scenarios found in real-world problems adaptations of benchmarks are required. In this paper, a practical problem is modeled based on the procedure of daily routing of a delivery company. New orders by customers are introduced dynamically during the working day and need to be integrated into the schedule. A multiple ant colony algorithm combined with powerful local search procedures is proposed to solve the dynamic vehicle routing problem with time windows. The performance is tested on a new benchmark based on simulations of a working day. The problems are taken from Solomon's benchmarks but a certain percentage of the orders are only revealed to the algorithm during operation time. Different versions of the MACS algorithm are tested and a high performing variant is identified. Finally, the algorithm is tested in situ: In a field study, the algorithm schedules a fleet of cars for a surveillance company. We compare the performance of the algorithm to that of the procedure used by the company and we summarize insights gained from the implementation of the real-world study. The results show that the multiple ant colony algorithm can get a much better solution on the academic benchmark problem and also can be integrated in a real-world environment.

  7. Electric Vehicle (EV) Charging Management with Dynamic Distribution System Tariff

    DEFF Research Database (Denmark)

    O'Connell, Niamh; Wu, Qiuwei; Østergaard, Jacob

    2011-01-01

    congestions in local distribution systems from the day-ahead planning perspective. Locational marginal pricing method was used to determine the dynamic distribution system tariff based on predicted day-ahead spot prices and predicted charging behaviors. Distribution grids of the Bornholm power system were......An electric vehicle (EV) charging schedule algorithm was proposed in this paper in order to charge EVs to meet EV users’ driving needs with the minimum EV charging cost and respect the local distribution system constraints. A day-ahead dynamic distribution system tariff scheme was proposed to avoid...

  8. Powertrain dynamics and control of a two speed dual clutch transmission for electric vehicles

    Science.gov (United States)

    Walker, Paul; Zhu, Bo; Zhang, Nong

    2017-02-01

    The purpose of this paper is to demonstrate the application of torque based powertrain control for multi-speed power shifting capable electric vehicles. To do so simulation and experimental studies of the shift transient behaviour of dual clutch transmission equipped electric vehicle powertrains is undertaken. To that end a series of power-on and power-off shift control strategies are then developed for both up and down gear shifts, taking note of the friction load requirements to maintain positive driving load for power-on shifting. A mathematical model of an electric vehicle powertrain is developed including a DC equivalent circuit model for the electric machine and multi-body dynamic model of the powertrain system is then developed and integrated with a hydraulic clutch control system model. Integral control of the powertrain is then performed through simulations on the develop powertrain system model for each of the four shift cases. These simulation results are then replicated on a full scale powertrain test rig. To evaluate the performance of results shift duration and vehicle jerk are used as metrics to demonstrate that the presented strategies are effective for shift control in electric vehicles. Qualitative comparison of both theoretical and experimental results demonstrates reasonable agreement between simulated and experimental outcomes.

  9. Dynamic Flow Control Strategies of Vehicle SCR Urea Dosing System

    Institute of Scientific and Technical Information of China (English)

    LIN Wei; ZHANG Youtong; ASIF Malik

    2015-01-01

    Selective Catalyst Reduction(SCR) Urea Dosing System(UDS) directly affects the system accuracy and the dynamic response performance of a vehicle. However, the UDS dynamic response is hard to keep up with the changes of the engine’s operating conditions. That will lead to low NOX conversion efficiency or NH3 slip. In order to optimize the injection accuracy and the response speed of the UDS in dynamic conditions, an advanced control strategy based on an air-assisted volumetric UDS is presented. It covers the methods of flow compensation and switching working conditions. The strategy is authenticated on an UDS and tested in different dynamic conditions. The result shows that the control strategy discussed results in higher dynamic accuracy and faster dynamic response speed of UDS. The inject deviation range is improved from being between–8%and 10%to–4%and 2%and became more stable than before, and the dynamic response time was shortened from 200 ms to 150 ms . The ETC cycle result shows that after using the new strategy the NH3 emission is reduced by 60%, and the NOX emission remains almost unchanged. The trade-off between NOX conversion efficiency and NH3 slip is mitigated. The studied flow compensation and switching working conditions can improve the dynamic performance of the UDS significantly and make the UDS dynamic response keep up with the changes of the engine’s operating conditions quickly.

  10. Open Automated Demand Response Dynamic Pricing Technologies and Demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Ghatikar, Girish; Mathieu, Johanna L.; Piette, Mary Ann; Koch, Ed; Hennage, Dan

    2010-08-02

    This study examines the use of OpenADR communications specification, related data models, technologies, and strategies to send dynamic prices (e.g., real time prices and peak prices) and Time of Use (TOU) rates to commercial and industrial electricity customers. OpenADR v1.0 is a Web services-based flexible, open information model that has been used in California utilities' commercial automated demand response programs since 2007. We find that data models can be used to send real time prices. These same data models can also be used to support peak pricing and TOU rates. We present a data model that can accommodate all three types of rates. For demonstration purposes, the data models were generated from California Independent System Operator's real-time wholesale market prices, and a California utility's dynamic prices and TOU rates. Customers can respond to dynamic prices by either using the actual prices, or prices can be mapped into"operation modes," which can act as inputs to control systems. We present several different methods for mapping actual prices. Some of these methods were implemented in demonstration projects. The study results demonstrate show that OpenADR allows interoperability with existing/future systems/technologies and can be used within related dynamic pricing activities within Smart Grid.

  11. Influence of MR damper modeling on vehicle dynamics

    Science.gov (United States)

    de-J Lozoya-Santos, Jorge; Morales-Menendez, Ruben; Ramirez-Mendoza, Ricardo A.; Vivas-Lopez, Carlos A.

    2013-12-01

    The influence of magneto-rheological damper modeling in vehicle dynamics analysis is studied. Several tests using CarSim™ compare a four-corner controlled semi-active suspension for two different magneto-rheological damper models. The magneto-rheological damper characteristics were identified from experimental data. A model-free controller discards the influence of control and emphasizes the compliance of the magneto-rheological damper model; the characteristics of the vehicle index performance considered were comfort, road holding, handling, roll and suspension deflection. The comparison for magneto-rheological damper dynamics and semi-active suspension covers the automotive bandwidth. The results show that high precision of a magneto-rheological damper model as an isolated feature is not enough. The magneto-rheological damper model, as a component of a vehicle suspension, needs to simulate with passive precision and variable damping forces. The findings exhibit the requisite of accurate models for evaluation of semi-active control systems in classic tests. The lack of the friction component in a magneto-rheological damper model leads to an overestimation in handling and stability.

  12. Classroom Demonstrations Of Atmosphere-ocean Dynamics: Baroclinic Instability

    Science.gov (United States)

    Aurnou, Jonathan; Nadiga, B. T.

    2008-09-01

    Here we will present simple hands-on experimental demonstrations that show how baroclinic instabilities develop in rotating fluid dynamical systems. Such instabilities are found in the Earth's oceans and atmosphere as well as in the atmospheres and oceans of planetary bodies throughout the solar system and beyond. Our inexpensive experimental apparatus consists of a vinyl-record player, a wide shallow pan, and a weighted, dyed block of ice. Most directly, these demonstrations can be used to explain winter-time atmospheric weather patterns observed in Earth's mid-latitudes.

  13. Overview of the solar dynamic ground test demonstration program

    Science.gov (United States)

    Shaltens, Richard K.; Boyle, Robert V.

    1993-01-01

    The Solar Dynamic (SD) Ground Test Demonstration (GTD) program demonstrates the availability of SD technologies in a simulated space environment at the NASA Lewis Research Center (LeRC) vacuum facility. An aerospace industry/ government team is working together to design, fabricate, build, and test a complete SD system. This paper reviews the goals and status of the SD GTD program. A description of the SD system includes key design features of the system, subsystems, and components as reported at the Critical Design Review (CDR).

  14. Experimental demonstration of a new concept of drag reduction and thermal protection for hypersonic vehicles

    Institute of Scientific and Technical Information of China (English)

    Zonglin Jiang; Yunfeng Liu; Guilai Han; Wei Zhao

    2009-01-01

    A new idea of drag reduction and thermal protection for hypersonic vehicles is proposed based on the combination of a physical spike and lateral jets for shock-reconstruction. The spike recasts the bow shock in front of a blunt body into a conical shock, and the lateral jets work to protect the spike tip from overheating and to push the conical shock away from the blunt body when a pitching angle exists during flight. Experiments are conducted in a hypersonic wind tunnel at a nominal Math number of 6. It is demonstrated that the shock/shock interaction on the blunt body is avoided due to injection and the peak pressure at the reattachment point is reduced by 70% under a 4°attack angle.

  15. Dynamic Demonstration of Ceramic Grain Growth in Three Dimensions

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Microstructural evolutions of ceramic grain growth we re dynamically demonstrated with 3D graphical display techniques. Based on the p rinciples of grain growth in ceramics, the data of coordination in different ato ms were calculated with Monte-Carlo method at atomistic scale. Realistic images in three-dimension were displayed onto two-dimension monitor by projection, i llumination and atomization, using Visual C++ and OpenGL languages. Different small spheres were used to model different kind of atoms,...

  16. Research, development, and demonstration of lead-acid batteries for electric vehicle propulsion. Annual report, 1980

    Energy Technology Data Exchange (ETDEWEB)

    1981-03-01

    The progress and status of Eltra's Electric Vehicle Battery Program during FY-80 are presented under five divisional headings: Research on Components and Processes; Development of Cells and Modules for Electric Vehicle Propulsion; Sub-Systems; Pilot Line Production of Electric Vehicle Battery Prototypes; and Program Management.

  17. Forming the Calculated Dynamic Transmission Systems of Wheeled Vehicles

    Directory of Open Access Journals (Sweden)

    A. B. Fominykh

    2017-01-01

    Full Text Available To calculate dynamic loading of transmission parts of wheeled vehicles, it is necessary to build up the appropriate calculated dynamic systems and determine their inertial, elastic, and damping parameters.The initial point of this process is to form an initial dynamic system. Hereafter, to cut the time of computations there is a need to reduce the number of masses of this system, and sometimes simplify its structure. The main requirement to be fulfilled in this case is that the calculated dynamical system is to be equivalent to the initial one (in terms of similarity of the vibrational process characteristics in these systems, i.e., the frequencies and modes of oscillations of both systems, their amplitude-frequency characteristics. This is possible when the energy characteristics of the corresponding systems are equal, i.e. their kinetic and potential energies, dissipative functions, and external force energies.Usually, when forming the initial and calculated dynamic systems, all types of friction are reduced to a linearly viscous one. However, it disables us to investigate the motion of these systems if there is an arbitrary, in particular, poly-harmonic action (for example, on the side of the internal combustion engine, since in this case the linear friction coefficients given will depend on the frequency and amplitude of the oscillations.The paper is aimed at determining the equivalent parameters of calculated dynamic systems of wheeled vehicles, including the dissipative parameters for the general case of friction.On the basis of energy principles, the expressions are obtained to determine the equivalent inertial, elastic, and damping parameters of the calculated dynamical systems of wheeled vehicles when the structure is changed and the number of masses of the system is decreased. The presented technique enables us to investigate the motion of these systems under arbitrary, including poly-harmonic, action on the system, using the

  18. Automated Guide Vehicles Dynamic Scheduling Based on Annealing Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Zou Gan

    2013-05-01

    Full Text Available Dispatching automated guided vehicles (AGVs is the common approach for AGVs scheduling in practice, the information about load arrivals in advance was not used to optimize the performance of the automated guided vehicles system (AGVsS. According to the characteristics of the AGVsS, the mathematical model of AGVs scheduling was established. A heuristic algorithm called Annealing Genetic Algorithm (AGA was presented to deal with the AGVs scheduling problem,and applied the algorithm dynamically by using it repeatedly under a combined rolling optimization strategy. the performance of the proposed approach for AGVs scheduling was compared with the dispatching rules by simulation. Results showed that the approach performs significantly better than the dispatching rules and proved that it is really effective for AGVsS.

  19. Overview of Orion Crew Module and Launch Abort Vehicle Dynamic Stability

    Science.gov (United States)

    Owens, Donald B.; Aibicjpm. Vamessa V.

    2011-01-01

    With the retirement of the Space Shuttle, NASA is designing a new spacecraft, called Orion, to fly astronauts to low earth orbit and beyond. Characterization of the dynamic stability of the Orion spacecraft is important for the design of the spacecraft and trajectory construction. Dynamic stability affects the stability and control of the Orion Crew Module during re-entry, especially below Mach = 2.0 and including flight under the drogues. The Launch Abort Vehicle is affected by dynamic stability as well, especially during the re-orientation and heatshield forward segments of the flight. The dynamic stability was assessed using the forced oscillation technique, free-to-oscillate, ballistic range, and sub-scale free-flight tests. All of the test techniques demonstrated that in heatshield-forward flight the Crew Module and Launch Abort Vehicle are dynamically unstable in a significant portion of their flight trajectory. This paper will provide a brief overview of the Orion dynamic aero program and a high-level summary of the dynamic stability characteristics of the Orion spacecraft.

  20. Sustained small oscillations in nonlinear control systems. [launch vehicle dynamics

    Science.gov (United States)

    George, J. H.; Gunderson, R. W.; Hahn, H.

    1975-01-01

    Some results of bifurcation theory were used to study the existence of small-amplitude periodic behavior in launch vehicle dynamics, assuming that nonlinearity exists as a cubic term in the rudder response. The analysis follows closely Sattinger's (1973) approach to the theory of periodic bifurcations. The conditions under which a bifurcating branch of orbitally stable periodic solutions will exist are determined. It is shown that in more complicated cases, the conditions under which the system matrix has a pair of simple purely imaginary eigenvalues can be determined with the aid of linear stability techniques.

  1. A New Application of Multi-Body System Dynamics in Vehicle-Road Interaction Simulation

    Institute of Scientific and Technical Information of China (English)

    RenWei-qun; ZhangYun-qing; JinGuo-dong

    2003-01-01

    In vehicle-road interaction simulation, multibody system (MBS) dynamics as well as the corresponding software ADAMS has been employed to model the nonlinear vehicle in more detail. The simulation method has been validated by the test data, and been compared to the former simple models. This method can be used for estimating the effects of dynamic tire forces and other vehicle features on road damage so that the “road-friendliness” can be assessed in vehicle design process.

  2. Demonstration Project for a Multi-Material Lightweight Prototype Vehicle as Part of the Clean Energy Dialogue with Canada

    Energy Technology Data Exchange (ETDEWEB)

    Skszek, Tim [Vehma International Of America, Inc., Troy, MI (United States)

    2015-12-29

    The intent of the Multi-Material Lightweight Vehicle (“MMLV”) was to assess the feasibility of achieving a significant level of vehicle mass reduction, enabling engine downsizing resulting in a tangible fuel reduction and environmental benefit. The MMLV project included the development of two (2) lightweight vehicle designs, referred to as Mach-I and Mach-II MMLV variants, based on a 2013 Ford production C/D segment production vehicle (Fusion). Weight comparison, life cycle assessment and limited full vehicle testing are included in the project scope. The Mach-I vehicle variant was comprised of materials and processes that are commercially available or previously demonstrated. The 363 kg mass reduction associated with the Mach-I design enabled use of a one-liter, three-cylinder, gasoline turbocharged direct injection engine, maintaining the performance and utility of the baseline vehicle. The full MMLV project produced seven (7) MMLV Mach-I “concept vehicles” which were used for testing and evaluation. The full vehicle tests confirmed that MMLV Mach-I concept vehicle performed approximately equivalent to the baseline 2013 Ford Fusion vehicle thereby validating the design of the multi material lightweight vehicle design. The results of the Life Cycle Assessment, conducted by third party consultant, indicated that if the MMLV Mach-I design was built and operated in North America for 250,000 km (155,343 miles) it would produce significant environmental and fuel economy benefits including a 16% reduction in Global Warming Potential (GWP) and 16% reduction in Total Primary Energy (TPE). The LCA calculations estimated the combined fuel economy of 34 mpg (6.9 l/100 km) associated with the MMLV Mach-I Design compared to 28 mpg (8.4 l/100 km) for the 2013 Ford Fusion.

  3. Disturbance decoupling robust control of vehicle full speed cruise dynamic system

    Institute of Scientific and Technical Information of China (English)

    BIN Yang; LI KeQiang; FENG NengLian

    2009-01-01

    In this study,an innovative dynamics model of LFS(longitudinal vehicle full-speed cruise system)is developed by lumping the dynamics of a controlled vehicle and an inter-vehicles together.On account of the external disturbance,parameters uncertainty and the nonlinearity within LFS,a DDRC(disturbance decoupling robust control)method is proposed.For this method,the theory of NDD(nonlinear disturbance decoupling)is utilized firstly to separate the external disturbance from certain part of the proposed dynamics model.Then,the invariance over the sliding mode of VSC(variable structure control)is used to eliminate the influence of remaining uncertain part.Finally,the DDRC method is adopted to design an LFS ACC(adaptive cruise control)system,and some numerical simulations are carried out to validate its performance.The simulation results demonstrate that the proposed control system not only exhibits an expected dynamic response,high tracking accuracy and a strong robustness,but also achieves a global optimization by means of a simplified control structure.

  4. The Dynamic Multi-Period Vehicle Routing Problem

    DEFF Research Database (Denmark)

    Wen, Min; Cordeau, Jean-Francois; Laporte, Gilbert

    This paper considers the Dynamic Multi-Period Vehicle Routing Problem which deals with the distribution of orders from a depot to a set of customers over a multi-period time horizon. Customer orders and their feasible service periods are dynamically revealed over time. The objectives...... are to minimize total travel costs and customer waiting, and to balance the daily workload over the planning horizon. This problem originates from a large distributor operating in Sweden. It is modeled as a mixed integer linear program, and solved by means of a three-phase heuristic that works over a rolling...... planning horizon. The multi-objective aspect of the problem is handled through a scalar technique approach. Computational results show that our solutions improve upon those of the Swedish distributor....

  5. The dynamic multi-period vehicle routing problem

    DEFF Research Database (Denmark)

    Wen, Min; Cordeau, Jean-Francois; Laporte, Gilbert

    2010-01-01

    This paper considers the Dynamic Multi-Period Vehicle Routing Problem which deals with the distribution of orders from a depot to a set of customers over a multi-period time horizon. Customer orders and their feasible service periods are dynamically revealed over time. The objectives...... planning horizon. The multi-objective aspect of the problem is handled through a scalar technique approach. Computational results show that the proposed approach can yield high quality solutions within reasonable running times....... are to minimize total travel costs and customer waiting, and to balance the daily workload over the planning horizon. This problem originates from a large distributor operating in Sweden. It is modeled as a mixed integer linear program, and solved by means of a three-phase heuristic that works over a rolling...

  6. The Dynamics of a Railway Vehicle on a Disturbed Track

    DEFF Research Database (Denmark)

    Christiansen, Lasse Engbo

    of the main differences between this work and previous ones is that the vertical degrees of freedom are included making the model very realistic as this allows a dynamic calculation of the penetration depth in the contact area. In chapter two the model of the bogie is described, this is followed by a chapter...... describing how the wheel-rail interaction is modelled. The fourth chapter gives a presentation of the numerical algorithms used in this work. The fifth chapter presents the results obtained during this work, it begins with an brief investigation of the dynamics when running on a straight track. The second...... changing the velocity of the railway vehicle and the phase between the sinusoidal irregularities of the rails. In the final section the eigenfrequencies of the bogie are found and the most important modes are described. Chapter six is a discussion of the obtained results, and these are related...

  7. Hanford tank initiative vehicle/based waste retrieval demonstration report phase II, track 2

    Energy Technology Data Exchange (ETDEWEB)

    Berglin, E.J.

    1997-07-31

    Using the versatile TracPUMpTm, Environmental Specialties Group, LLC (ES) performed a successful Phase 11 demonstration of a Vehicle- Based Waste Retrieval System (VWRS) for removal of waste material and residual liquid found in the Hanford Underground Storage Tanks (ousts). The purpose of this demonstration was to address issues pertaining to the use of a VWRS in OUSTS. The demonstration also revealed the waste removal capabilities of the TracPumpTm and the most effective techniques and equipment to safely and effectively remove waste simulants. ES successfully addressed the following primary issues: I . Dislodge and convey the waste forms present in the Hanford OUSTS; 2. Access the UST through tank openings as small as twenty-four inches in diameter; 3. Traverse a variety of terrains including slopes, sludges, rocks and hard, slippery surfaces without becoming mired; 4. Dislodge and convey waste within the confinement of the Decontamination Containment Capture Vessel (DCCV) and with minimal personnel exposure; 5. Decontaminate equipment to acceptable limits during retrieval from the UST; 6. Perform any required maintenance within the confinement of the DCCV; and 7. Maintain contaminate levels ``as low as reasonably achievable`` (ALARA) within the DCCV due to its crevice and comer-free design. The following materials were used to simulate the physical characteristics of wastes found in Hanford`s OUSTS: (1) Hardpan: a clay-type material that has high shear strength; (2) Saltcake: a fertilizer-based material that has high compressive strength; and (3) Wet Sludge.- a sticky, peanut- butter- like material with low shear strength. Four test beds were constructed of plywood and filled with a different simulant to a depth of eight to ten inches. Three of the test beds were of homogenous simulant material, while the fourth bed consisted of a mixture of all three simulant types.

  8. Autonomous Navigation of Small Uavs Based on Vehicle Dynamic Model

    Science.gov (United States)

    Khaghani, M.; Skaloud, J.

    2016-03-01

    This paper presents a novel approach to autonomous navigation for small UAVs, in which the vehicle dynamic model (VDM) serves as the main process model within the navigation filter. The proposed method significantly increases the accuracy and reliability of autonomous navigation, especially for small UAVs with low-cost IMUs on-board. This is achieved with no extra sensor added to the conventional INS/GNSS setup. This improvement is of special interest in case of GNSS outages, where inertial coasting drifts very quickly. In the proposed architecture, the solution to VDM equations provides the estimate of position, velocity, and attitude, which is updated within the navigation filter based on available observations, such as IMU data or GNSS measurements. The VDM is also fed with the control input to the UAV, which is available within the control/autopilot system. The filter is capable of estimating wind velocity and dynamic model parameters, in addition to navigation states and IMU sensor errors. Monte Carlo simulations reveal major improvements in navigation accuracy compared to conventional INS/GNSS navigation system during the autonomous phase, when satellite signals are not available due to physical obstruction or electromagnetic interference for example. In case of GNSS outages of a few minutes, position and attitude accuracy experiences improvements of orders of magnitude compared to inertial coasting. It means that during such scenario, the position-velocity-attitude (PVA) determination is sufficiently accurate to navigate the UAV to a home position without any signal that depends on vehicle environment.

  9. DYNAMIC RESPONSE OF PLATES DUE TO MOVING VEHICLES USING FINITE STRIP METHOD

    Institute of Scientific and Technical Information of China (English)

    程远胜; 张佑啟; 区达光

    2002-01-01

    Dynamic response of beam-like structures to moving vehicles has been extensive-ly studied. However, the study on dynamic response of plates to moving vehicles has so farreceived but scant attention. A plate-vehicle strip for simulating the interaction between arectangular plate and moving vehicles was described. For the portion of strips that are in di-rect contact with the moving vehicles, the plate-vehicle strips were employed. Conventionalplate finite strips were used to model the portion of strips that are not directly under the ac-tion of moving vehicles. In the analysis, each moving vehicle is idealized as a one-foot dy-namic system with the unsprung mass and sprund mass interconnected by a spring and adashpot. The numerical results obtained from the proposed method agree well with availableresults.

  10. Computational Fluid Dynamics Demonstration of Rigid Bodies in Motion

    Science.gov (United States)

    Camarena, Ernesto; Vu, Bruce T.

    2011-01-01

    The Design Analysis Branch (NE-Ml) at the Kennedy Space Center has not had the ability to accurately couple Rigid Body Dynamics (RBD) and Computational Fluid Dynamics (CFD). OVERFLOW-D is a flow solver that has been developed by NASA to have the capability to analyze and simulate dynamic motions with up to six Degrees of Freedom (6-DOF). Two simulations were prepared over the course of the internship to demonstrate 6DOF motion of rigid bodies under aerodynamic loading. The geometries in the simulations were based on a conceptual Space Launch System (SLS). The first simulation that was prepared and computed was the motion of a Solid Rocket Booster (SRB) as it separates from its core stage. To reduce computational time during the development of the simulation, only half of the physical domain with respect to the symmetry plane was simulated. Then a full solution was prepared and computed. The second simulation was a model of the SLS as it departs from a launch pad under a 20 knot crosswind. This simulation was reduced to Two Dimensions (2D) to reduce both preparation and computation time. By allowing 2-DOF for translations and 1-DOF for rotation, the simulation predicted unrealistic rotation. The simulation was then constrained to only allow translations.

  11. Navier-Stokes predictions of dynamic stability derivatives for air-breathing hypersonic vehicle

    Science.gov (United States)

    Liu, Xu; Liu, Wei; Zhao, Yunfei

    2016-01-01

    Dynamic derivatives are important parameters for designing vehicle trajectory and attitude control system that directly decide the divergence behavior of vibration of the aircraft open-loop system under interference. After calibration model validation, the dynamic behavior of air-breathing hypersonic vehicle WR-A is characterized. The unsteady flow field of aircraft forced simple harmonic vibration (SHV) is simulated using N-S equation. The direct damping derivatives, cross derivatives, acceleration derivatives and rotary derivatives of WR-A under different frequencies, amplitudes and positions of centroid are obtained. Research demonstrates that the proportion of acceleration derivatives, which represents the flow time lag effect, in the direct damping derivatives can be as high as 40% but is opposite to the damping derivative value symbols in some cases, contributing to dynamic instability. Numerical simulation on large-amplitude forced vibration of WR-A indicates that the aerodynamic behavior predicted by the dynamic derivative model agrees well with unsteady calculations. The inlet performance parameter derivatives are solved using the Etkin theory. The inlet performance parameters under large-amplitude vibration are successfully predicted using the dynamic derivative model. This offers a guideline for characterizing the dynamic internal flow field and unsteady inlet performance.

  12. Demonstration of Heavy Hybrid Diesel Fleet Vehicles Final Report Version 2

    Science.gov (United States)

    2016-03-29

    maintained to avoid losses due to uneven pavement , and representative of most installations. • Track Weather Station: ATC setup equipment to measure and...driver, he felt that the conventional utility truck provide a better, more rigid ride. Acceleration of the vehicle is very poor. The vehicles

  13. Development and Demonstration of a Magnesium-Intensive Vehicle Front-End Substructure

    Energy Technology Data Exchange (ETDEWEB)

    Logan, Stephen D. [United States Automotive Materials Partnership LLC, Southfield, MI (United States); Forsmark, Joy H. [United States Automotive Materials Partnership LLC, Southfield, MI (United States); Osborne, Richard [United States Automotive Materials Partnership LLC, Southfield, MI (United States)

    2016-07-01

    This project is the final phase (designated Phase III) of an extensive, nine-year effort with the objectives of developing a knowledge base and enabling technologies for the design, fabrication and performance evaluation of magnesium-intensive automotive front-end substructures intended to partially or completely replace all-steel comparators, providing a weight savings approaching 50% of the baseline. Benefits of extensive vehicle weight reduction in terms of fuel economy increase, extended vehicle range, vehicle performance and commensurate reductions in greenhouse gas emissions are well known. An exemplary vehicle substructure considered by the project is illustrated in Figure 1, along with the exterior vehicle appearance. This unibody front-end “substructure” is one physical objective of the ultimate design and engineering aspects established at the outset of the larger collective effort.

  14. Demonstration of improved vehicle fuel efficiency through innovative tire design, materials, and weight reduction technologies

    Energy Technology Data Exchange (ETDEWEB)

    Donley, Tim [Cooper Tire & Rubber Company Incorporated, Findlay, OH (United States)

    2014-12-31

    Cooper completed an investigation into new tire technology using a novel approach to develop and demonstrate a new class of fuel efficient tires using innovative materials technology and tire design concepts. The objective of this work was to develop a new class of fuel efficient tires, focused on the “replacement market” that would improve overall passenger vehicle fuel efficiency by 3% while lowering the overall tire weight by 20%. A further goal of this project was to accomplish the objectives while maintaining the traction and wear performance of the control tire. This program was designed to build on what has already been accomplished in the tire industry for rolling resistance based on the knowledge and general principles developed over the past decades. Cooper’s CS4 (Figure #1) premium broadline tire was chosen as the control tire for this program. For Cooper to achieve the goals of this project, the development of multiple technologies was necessary. Six technologies were chosen that are not currently being used in the tire industry at any significant level, but that showed excellent prospects in preliminary research. This development was divided into two phases. Phase I investigated six different technologies as individual components. Phase II then took a holistic approach by combining all the technologies that showed positive results during phase one development.

  15. GPC light shaper: static and dynamic experimental demonstrations

    DEFF Research Database (Denmark)

    Bañas, Andrew Rafael; Kopylov, Oleksii; Villangca, Mark Jayson;

    2014-01-01

    Generalized Phase Contrast (GPC) is an efficient method for generating speckle-free contiguous optical distributions useful in diverse applications such as static beam shaping, optical manipulation and, recently, for excitation in two-photon optogenetics. GPC allows efficient utilization of typical...... shapes that can find use in lightefficient industrial or commercial applications. Using a dynamic spatial light modulator, we also show simple and efficient beam shaping of reconfigurable shapes geared towards materials processing, biophotonics research and other contemporary applications. Our...... Gaussian lasers in such applications using binary-only phase modulation. In this work, we experimentally verify previously derived conditions for photon-efficient light shaping with GPC [Opt. Express 22(5), 5299 (2014)]. We demonstrate a compact implementation of GPC for creating practical illumination...

  16. Demonstration of Biodiesel in Non-deployed Ground Tactical Vehicles/Equipment

    Science.gov (United States)

    2010-06-01

    tactical vehicles in their March 2006 Position Statement – Stability of the biodiesel – Accelerated deterioration in high temperature environments...Concerns – Stability of the biodiesel – All sites – Accelerated deterioration in high temperature environments – Moody AFB (hot/humid) and MCAGCC 29... Palms (hot/dry) – Vehicle operation and fuel properties in low temperatures – NSWC Crane – Water affinity and microbial degradation – All sites

  17. Monitoring results of two PBS demonstration vehicles in the forestry industry in South Africa

    CSIR Research Space (South Africa)

    Nordengen, Paul A

    2010-03-01

    Full Text Available commissioned. Data including payload per trip, average trip speeds, kilometres travelled per month, average monthly fuel consumption, maintenance costs and records of incidents and accidents are collected on a monthly basis. 3.1 Payload During...: Monitoring results of two PBS vehicles in South Africa 6 3.2 Fuel Efficiency From a productivity perspective, fuel efficiency is one of the most important parameters to monitor. This section describes the performance of the PBS vehicles compared...

  18. Modal and Dynamic Analysis of a Vehicle with Kinetic Dynamic Suspension System

    Directory of Open Access Journals (Sweden)

    Bangji Zhang

    2016-01-01

    Full Text Available A novel kinetic dynamic suspension (KDS system is presented for the cooperative control of the roll and warp motion modes of off-road vehicles. The proposed KDS system consists of two hydraulic cylinders acting on the antiroll bars. Hence, the antiroll bars are not completely replaced by the hydraulic system, but both systems are installed. In this paper, the vibration analysis in terms of natural frequencies of different motion modes in frequency domain for an off-road vehicle equipped with different configurable suspension systems is studied by using the modal analysis method. The dynamic responses of the vehicle with different configurable suspension systems are investigated under different road excitations and maneuvers. The results of the modal and dynamic analysis prove that the KDS system can reduce the roll and articulation motions of the off-road vehicle without adding extra bounce stiffness and deteriorating the ride comfort. Furthermore, the roll stiffness is increased and the warp stiffness is decreased by the KDS system, which could significantly enhance handing performance and off-road capability.

  19. A Novel Dynamic Physical Storage Model for Vehicle Navigation Maps

    Directory of Open Access Journals (Sweden)

    Shaohua Wang

    2016-04-01

    Full Text Available The physical storage model is one of the key technologies for vehicle navigation maps used in a navigation system. However, the performance of most traditional storage models is limited in dynamic navigation due to the static storage format they use. In this paper, we proposed a new physical storage model, China Navigation Data Format (CNDF, which helped access and update the navigation data. The CNDF model used the reach-based hierarchy method to build a road hierarchal network, which enhanced the efficiency of data compression. It also adopted the Linear Link Coding method, in which the start position was combined with the end position as the identification code for multi-level links, and each link traced up-level links consistently without recording the array of identifications. The navigation map of East China (including Beijing, Tianjin, Shandong, Hebei, and Jiangsu at 1:10,000, generated using the CNDF model, and the real time traffic information in Beijing were combined to test the performance of a navigation system using an embedded navigation device. Results showed that it cost less than 1 second each time to refresh the navigation map, and the accuracy of the hierarchal shortest-path algorithm was 99.9%. Our work implied that the CNDF model is efficient in vehicle navigation applications.

  20. Dynamics of Micro-Air-Vehicle with Flapping Wings

    Directory of Open Access Journals (Sweden)

    K. Sibilski

    2004-01-01

    Full Text Available Small (approximately 6 inch long, or hand-held reconnaissance micro air vehicles (MAVs will fly inside buildings, and require hover for observation, and agility at low speeds to move in confined spaces. For this flight envelope insect-like flapping wings seem to be an optimal mode of flying. Investigation of the aerodynamics of flapping wing MAVs is very challenging. The problem involves complex unsteady, viscous flow (mainly laminar, with the moving wing generating vortices and interacting with them. At this early stage of research only a preliminary insight into the nature of the little known aerodynamics of MAVs has been obtained. This paper describes computational models for simulation of the controlled motion of a microelectromechanical flying insect – entomopter. The design of software simulation for entomopter flight (SSEF is presented. In particular, we will estimate the flight control algorithms and performance for a Micromechanical Flying Insect (MFI, a 80–100 mm (wingtip-to-wingtip device capable of sustained autonomous flight. The SSEF is an end-to-end tool composed of several modular blocks which model the wing aerodynamics and dynamics, the body dynamics, and in the future, the environment perception, control algorithms, the actuators dynamics, and the visual and inertial sensors. We present the current state of the art of its implementation, and preliminary results. 

  1. Dispersion analysis techniques within the space vehicle dynamics simulation program

    Science.gov (United States)

    Snow, L. S.; Kuhn, A. E.

    1975-01-01

    The Space Vehicle Dynamics Simulation (SVDS) program was evaluated as a dispersion analysis tool. The Linear Error Analysis (LEA) post processor was examined in detail and simulation techniques relative to conducting a dispersion analysis using the SVDS were considered. The LEA processor is a tool for correlating trajectory dispersion data developed by simulating 3 sigma uncertainties as single error source cases. The processor combines trajectory and performance deviations by a root-sum-square (RSS process) and develops a covariance matrix for the deviations. Results are used in dispersion analyses for the baseline reference and orbiter flight test missions. As a part of this study, LEA results were verified as follows: (A) Hand calculating the RSS data and the elements of the covariance matrix for comparison with the LEA processor computed data. (B) Comparing results with previous error analyses. The LEA comparisons and verification are made at main engine cutoff (MECO).

  2. Review of delta wing space shuttle vehicle dynamics

    Science.gov (United States)

    Reding, J. P.; Ericsson, L. E.

    1972-01-01

    The unsteady aerodynamics of the delta planform, high cross range, shuttle orbiter were investigated. It has been found that these vehicles are subject to five unsteady flow phenomena that could compromise the flight dynamics. They are: (1) leeside shock induced separation, (2) sudden leading edge stall, (3) vortex burst, (4) bow shock-flap shock interaction, (5) forebody vorticity. Trajectory shaping is seen as the most powerful means of avoiding the detrimental effects of the stall phenomena. However, stall must be fixed or controlled when traversing the stall region. The other phenomena may be controlled by carefully programmed control deflections and some configuration modification. Ways to alter the occurrence of the various flow conditions are explored.

  3. Shape optimization of an autonomous underwater vehicle with a ducted propeller using computational fluid dynamics analysis

    Directory of Open Access Journals (Sweden)

    Tae-Hwan Joung

    2012-03-01

    Full Text Available Autonomous Underwater Vehicles (AUVs provide a useful means of collecting detailed oceano-graphic information. The hull resistance of an AUV is an important factor in determining the power requirements and range of the vehicle. This paper describes a procedure using Computational Fluid Dynamics (CFD for determining the hull resistance of an AUV under development, for a given propeller rotation speed and within a given range of AUV velocities. The CFD analysis results reveal the distribution of the hydrodynamic values (velocity, pressure, etc. around the AUV hull and its ducted propeller. The paper then proceeds to present a methodology for optimizing the AUV profile in order to reduce the total resistance. This paper demonstrates that shape optimization of conceptual designs is possible using the commercial CFD package contained in Ansys™. The optimum design to minimize the drag force of the AUV was identified for a given object function and a set of constrained design parameters.

  4. Dynamic route guidance strategy in a two-route pedestrian-vehicle mixed traffic flow system

    Science.gov (United States)

    Liu, Mianfang; Xiong, Shengwu; Li, Bixiang

    2016-05-01

    With the rapid development of transportation, traffic questions have become the major issue for social, economic and environmental aspects. Especially, during serious emergencies, it is very important to alleviate road traffic congestion and improve the efficiency of evacuation to reduce casualties, and addressing these problems has been a major task for the agencies responsible in recent decades. Advanced road guidance strategies have been developed for homogeneous traffic flows, or to reduce traffic congestion and enhance the road capacity in a symmetric two-route scenario. However, feedback strategies have rarely been considered for pedestrian-vehicle mixed traffic flows with variable velocities and sizes in an asymmetric multi-route traffic system, which is a common phenomenon in many developing countries. In this study, we propose a weighted road occupancy feedback strategy (WROFS) for pedestrian-vehicle mixed traffic flows, which considers the system equilibrium to ease traffic congestion. In order to more realistic simulating the behavior of mixed traffic objects, the paper adopted a refined and dynamic cellular automaton model (RDPV_CA model) as the update mechanism for pedestrian-vehicle mixed traffic flow. Moreover, a bounded rational threshold control was introduced into the feedback strategy to avoid some negative effect of delayed information and reduce. Based on comparisons with the two previously proposed strategies, the simulation results obtained in a pedestrian-vehicle traffic flow scenario demonstrated that the proposed strategy with a bounded rational threshold was more effective and system equilibrium, system stability were reached.

  5. Teaching Advanced Vehicle Dynamics Using a Project Based Learning (PBL) Approach

    Science.gov (United States)

    Redkar, Sangram

    2012-01-01

    This paper presents an interesting teaching experiment carried out at XXX University. The author offered a new course in computational/analytical vehicle dynamics to senior undergraduate students, graduate students and practicing engineers. The objective of the course was to present vehicle dynamics theory with practical applications using…

  6. Teaching Advanced Vehicle Dynamics Using a Project Based Learning (PBL) Approach

    Science.gov (United States)

    Redkar, Sangram

    2012-01-01

    This paper presents an interesting teaching experiment carried out at XXX University. The author offered a new course in computational/analytical vehicle dynamics to senior undergraduate students, graduate students and practicing engineers. The objective of the course was to present vehicle dynamics theory with practical applications using…

  7. Ascent guidance for air-breathing hypersonic vehicles based on dynamic inversion

    Directory of Open Access Journals (Sweden)

    Xing Liu

    2017-05-01

    Full Text Available This article presents an adaptive ascent guidance strategy based on dynamic inversion for air-breathing hypersonic vehicles. Since dynamic inversion is effective to deal with nonlinear problems, this method is employed here to design the ascent guidance command. Compared with conventional dynamic inversion, an adaptive scheme is added into the guidance strategy, which significantly improves the robust performance of this method. And the stability analysis is given to prove the convergence of the nonlinear system. Besides, considering the real-world dynamic motions of the vehicle should be aware to calculate the guidance command instead of referring to the nominal model, the least squares algorithm with forgetting factor is adopted in this article to estimate the real thrust acceleration. And the reference trajectory generated online by polynomial fitting shows better adaptation to the change of flight environment and less computation time than other trajectory generation methods. Results of simulation are provided to demonstrate the feasibility and effectiveness of this approach.

  8. End-To-End Simulation of Launch Vehicle Trajectories Including Stage Separation Dynamics

    Science.gov (United States)

    Albertson, Cindy W.; Tartabini, Paul V.; Pamadi, Bandu N.

    2012-01-01

    The development of methodologies, techniques, and tools for analysis and simulation of stage separation dynamics is critically needed for successful design and operation of multistage reusable launch vehicles. As a part of this activity, the Constraint Force Equation (CFE) methodology was developed and implemented in the Program to Optimize Simulated Trajectories II (POST2). The objective of this paper is to demonstrate the capability of POST2/CFE to simulate a complete end-to-end mission. The vehicle configuration selected was the Two-Stage-To-Orbit (TSTO) Langley Glide Back Booster (LGBB) bimese configuration, an in-house concept consisting of a reusable booster and an orbiter having identical outer mold lines. The proximity and isolated aerodynamic databases used for the simulation were assembled using wind-tunnel test data for this vehicle. POST2/CFE simulation results are presented for the entire mission, from lift-off, through stage separation, orbiter ascent to orbit, and booster glide back to the launch site. Additionally, POST2/CFE stage separation simulation results are compared with results from industry standard commercial software used for solving dynamics problems involving multiple bodies connected by joints.

  9. Demonstration of Self-Training Autonomous Neural Networks in Space Vehicle Docking Simulations

    Science.gov (United States)

    Patrick, M. Clinton; Thaler, Stephen L.; Stevenson-Chavis, Katherine

    2006-01-01

    Neural Networks have been under examination for decades in many areas of research, with varying degrees of success and acceptance. Key goals of computer learning, rapid problem solution, and automatic adaptation have been elusive at best. This paper summarizes efforts at NASA's Marshall Space Flight Center harnessing such technology to autonomous space vehicle docking for the purpose of evaluating applicability to future missions.

  10. Control of a high beta maneuvering reentry vehicle using dynamic inversion.

    Energy Technology Data Exchange (ETDEWEB)

    Watts, Alfred Chapman

    2005-05-01

    The design of flight control systems for high performance maneuvering reentry vehicles presents a significant challenge to the control systems designer. These vehicles typically have a much higher ballistic coefficient than crewed vehicles like as the Space Shuttle or proposed crew return vehicles such as the X-38. Moreover, the missions of high performance vehicles usually require a steeper reentry flight path angle, followed by a pull-out into level flight. These vehicles then must transit the entire atmosphere and robustly perform the maneuvers required for the mission. The vehicles must also be flown with small static margins in order to perform the required maneuvers, which can result in highly nonlinear aerodynamic characteristics that frequently transition from being aerodynamically stable to unstable as angle of attack increases. The control system design technique of dynamic inversion has been applied successfully to both high performance aircraft and low beta reentry vehicles. The objective of this study was to explore the application of this technique to high performance maneuvering reentry vehicles, including the basic derivation of the dynamic inversion technique, followed by the extension of that technique to the use of tabular trim aerodynamic models in the controller. The dynamic inversion equations are developed for high performance vehicles and augmented to allow the selection of a desired response for the control system. A six degree of freedom simulation is used to evaluate the performance of the dynamic inversion approach, and results for both nominal and off nominal aerodynamic characteristics are presented.

  11. Aeromechanical stability analysis of a multirotor vehicle with application to hybrid heavy lift helicopter dynamics

    Science.gov (United States)

    Venkatesan, C.; Friedmann, P. P.

    1984-01-01

    The Hybrid Heavy Lift Helicopter (HHLH) is a potential candidate vehicle aimed at providing heavy lift capability at low cost. This vehicle consists of a buoyant envelope attached to a supporting structure. Four rotor systems are also attached to the supporting structure. Nonlinear equations of motion capable of modeling the dynamics of this multi-rotor/support frame/vehicle system have been developed and used to study the fundamental aeromechanical stability characteristics of this class of vehicles. The mechanism of coupling between the blades, supporting structure and rigid body modes is identified and the effect of buoyancy ratio (buoyant lift/total weight) on the vehicle dynamics is studied. It is shown that dynamics effects have a major role in the design of such vehicles. The analytical model developed is also useful for studying the aeromechanical stability of single rotor and tandem rotor coupled rotor/fuselage systems.

  12. Aeromechanical stability analysis of a multirotor vehicle with application to hybrid heavy lift helicopter dynamics

    Science.gov (United States)

    Venkatesan, C.; Friedmann, P. P.

    1984-01-01

    The Hybrid Heavy Lift Helicopter (HHLH) is a potential candidate vehicle aimed at providing heavy lift capability at low cost. This vehicle consists of a buoyant envelope attached to a supporting structure. Four rotor systems are also attached to the supporting structure. Nonlinear equations of motion capable of modeling the dynamics of this multi-rotor/support frame/vehicle system have been developed and used to study the fundamental aeromechanical stability characteristics of this class of vehicles. The mechanism of coupling between the blades, supporting structure and rigid body modes is identified and the effect of buoyancy ratio (buoyant lift/total weight) on the vehicle dynamics is studied. It is shown that dynamics effects have a major role in the design of such vehicles. The analytical model developed is also useful for studying the aeromechanical stability of single rotor and tandem rotor coupled rotor/fuselage systems.

  13. Dynamics of hypersonic flight vehicles exhibiting significant aeroelastic and aeropropulsive interactions

    Science.gov (United States)

    Chavez, Frank R.; Schmidt, David K.

    1993-01-01

    With analytic expressions previously developed for the forces and moments acting on a generic hypersonic vehicle, it is of interest to investigate the relative importance of the aerodynamic and propulsive effects on the vehicle dynamics. It is shown that the vehicle's aerodynamics and propulsive forces are both very significant in the evaluation of key stability derivatives which dictate the vehicle's dynamic characteristics. It is also shown that the vehicle model selected is unstable in pitch and exhibits strong airframe/engine/elastic coupling. With the use of literal expressions for both the systems poles and zeros, as well as the stability derivatives, key vehicle dynamic characteristics are investigated. For small errors, or uncertainties, in either the aerodynamic or propulsive forces, significant errors in the frequency and damping of the dominant modes and zero locations will arise.

  14. Joint Test Plan for Gas Dynamic Spray Technology Demonstration

    Science.gov (United States)

    Lewis, Pattie

    2008-01-01

    Air Force Space Command (AFSPC) and NASA have similar missions, facilities, and structures located in similar harsh environments. Both are responsible for a number of facilities/structures with metallic structural and non-structural components in highly and moderately corrosive environments. Regardless of the corrosivity of the environment, all metals require periodic maintenance activity to guard against the insidious effects of corrosion and thus ensure that structures meet or exceed design or performance life. The standard practice for protecting metallic substrates in atmospheric environments is the use of an applied coating system. Current coating systems used across AFSPC and NASA contain volatile organic compounds (VOCs) and hazardous air pollutants (HAPs). These coatings are subject to environmental regulations at the Federal and State levels that limit their usage. In addition, these coatings often cannot withstand the high temperatures and exhaust that may be experienced by AFSPC and NASA structures. In response to these concerns, AFSPC and NASA have approved the use of thermal spray coatings (TSCs). Thermal spray coatings are extremely durable and environmentally friendly coating alternatives, but utilize large cumbersome equipment for application that make the coatings difficult and time consuming to repair. Other concerns include difficulties coating complex geometries and the cost of equipment, training, and materials. Gas Dynamic Spray (GDS) technology (also known as Cold Spray) will be evaluated as a smaller, more maneuverable repair method as well as for areas where thermal spray techniques are not as effective. The technology can result in reduced maintenance and thus reduced hazardous materials/wastes associated with current processes. Thermal spray and GDS coatings also have no VOCs and are environmentally preferable coatings. To achieve a condition suitable for the application of a coating system, including GDS coatings, the substrate must

  15. Gas Dynamic Spray Technology Demonstration Project Management. Joint Test Report

    Science.gov (United States)

    Lewis, Pattie

    2011-01-01

    The standard practice for protecting metallic substrates in atmospheric environments is the use of an applied coating system. Current coating systems used across AFSPC and NASA contain volatile organic compounds (VOCs) and hazardous air pollutants (HAPs). These coatings are sUbject to environmental regulations at the Federal and State levels that limit their usage. In addition, these coatings often cannot withstand the high temperatures and exhaust that may be experienced by Air Force Space Command (AFSPC) and NASA structures. In response to these concerns, AFSPC and NASA have approved the use of thermal spray coatings (TSCs). Thermal spray coatings are extremely durable and environmentally friendly coating alternatives, but utilize large cumbersome equipment for application that make the coatings difficult and time consuming to repair. Other concerns include difficulties coating complex geometries and the cost of equipment, training, and materials. Gas Dynamic Spray (GOS) technology (also known as Cold Spray) was evaluated as a smaller, more maneuverable repair method as well as for areas where thermal spray techniques are not as effective. The technology can result in reduced maintenance and thus reduced hazardous materials/wastes associated with current processes. Thermal spray and GOS coatings also have no VOCs and are environmentally preferable coatings. The primary objective of this effort was to demonstrate GDS technology as a repair method for TSCs. The aim was that successful completion of this project would result in approval of GDS technology as a repair method for TSCs at AFSPC and NASA installations to improve corrosion protection at critical systems, facilitate easier maintenance activity, extend maintenance cycles, eliminate flight hardware contamination, and reduce the amount of hazardous waste generated.

  16. New literal approximations for the longitudinal dynamic characteristics of flexible flight vehicles

    Science.gov (United States)

    Livneh, Rafael; Schmidt, David K.

    1992-01-01

    The goal of the literal approximation method is to obtain simple literal (analytical) approximations for key dynamic characteristics of flexible flight vehicles. A basic question regarding the method is its usefulness as an additional design tool for existing design and simulation procedures. Two aspects of this question are: (1) ease of derivation and use of the literal approximations, and (2) the suitability of one set of literal approximations to describe the dynamics of a large set of significantly different vehicles. These issues are addressed by incorporating symbolic manipulation software into the literal approximation method for the analysis of a fifth order model of the longitudinal dynamics of a flexible flight vehicle. The automated literal approximation generated in this fashion reduces the manual derivation time by an approximate factor of four. A single set of literal approximations is shown to provide adequate approximations for the dynamics of significantly different flight vehicles configurations, such as an aircraft, a missile, and a hypersonic vehicle.

  17. Dynamic model of vertical vehicle-subgrade coupled system under secondary suspension

    Institute of Scientific and Technical Information of China (English)

    LIANG Bo; LUO Hong; MA Xue-ning

    2007-01-01

    As it is known, track transportation can be divided into track system above and track system below. While the train is moving, the parts above and below are interacted and influenced. Therefore, in fact, the problem of track transportation is the match between the vehicle and the railway line system. In this paper, on a basis of dynamic analysis of the vehicle-subgrade model of vertical coupled system under primary suspension,utilizing track maintenance standard and simulating track irregularity excitation, the dynamic interaction of vehicle-track-subgrade system is researched in theory and dynamic model of the vertical vehicle-track-subgrade coupled system under secondary suspension is established by compatibility condition of deformation. Even this model considers the actual structure of a vehicle, also considers vibration characteristic of the substructure of track including subgrade and foundation. All these work want to be benefit for understanding and design about the dynamic characters of subgrade in high speed railway.

  18. A New Application of Multi- Body System Dynamics in Vehicle- Road Interaction Simulation

    Institute of Scientific and Technical Information of China (English)

    Ren Wei-qun; Zhang Yun-qing; Jin Guo-dong

    2003-01-01

    In vehicle-road interaction simulation, multi-body system (MBS) dynamics as well as the corresponding software ADAMS has been employed to model the nonlinear vehicle in more detail. The simulation method has been vali-dated by the test data, and been compared to the former sim-ple models. This method can be used for estimating the effects of dynamic tire forces and other vehicle features on road damage so that the "road- friend liness" can be assessed in vehicle design process.

  19. Raven: An On-Orbit Relative Navigation Demonstration Using International Space Station Visiting Vehicles

    Science.gov (United States)

    Strube, Matthew; Henry, Ross; Skeleton, Eugene; Eepoel, John Van; Gill, Nat; McKenna, Reed

    2015-01-01

    Since the last Hubble Servicing Mission five years ago, the Satellite Servicing Capabilities Office (SSCO) at the NASA Goddard Space Flight Center (GSFC) has been focusing on maturing the technologies necessary to robotically service orbiting legacy assets-spacecraft not necessarily designed for in-flight service. Raven, SSCO's next orbital experiment to the International Space Station (ISS), is a real-time autonomous non-cooperative relative navigation system that will mature the estimation algorithms required for rendezvous and proximity operations for a satellite-servicing mission. Raven will fly as a hosted payload as part of the Space Test Program's STP-H5 mission, which will be mounted on an external ExPRESS Logistics Carrier (ELC) and will image the many visiting vehicles arriving and departing from the ISS as targets for observation. Raven will host multiple sensors: a visible camera with a variable field of view lens, a long-wave infrared camera, and a short-wave flash lidar. This sensor suite can be pointed via a two-axis gimbal to provide a wide field of regard to track the visiting vehicles as they make their approach. Various real-time vision processing algorithms will produce range, bearing, and six degree of freedom pose measurements that will be processed in a relative navigation filter to produce an optimal relative state estimate. In this overview paper, we will cover top-level requirements, experimental concept of operations, system design, and the status of Raven integration and test activities.

  20. Dynamic wireless charging of electric vehicles on the move with Mobile Energy Disseminators

    Directory of Open Access Journals (Sweden)

    Leandros A. Maglaras

    2015-06-01

    Full Text Available Dynamic wireless charging of electric vehicles (EVs is becoming a preferred method since it enables power exchange between the vehicle and the grid while the vehicle is moving. In this article, we present mobile energy disseminators (MED, a new concept, that can facilitate EVs to extend their range in a typical urban scenario. Our proposed method exploits Inter-Vehicle (IVC communications in order to eco-route electric vehicles taking advantage of the existence of MEDs. Combining modern communications between vehicles and state of the art technologies on energy transfer, vehicles can extend their travel time without the need for large batteries or extremely costly infrastructure. Furthermore, by applying intelligent decision mechanisms we can further improve the performance of the method.

  1. Advanced Mobility Testbed for Dynamic Semi-Autonomous Unmanned Ground Vehicles

    Science.gov (United States)

    2015-04-24

    Introduction Integrated simulation capabilities that are high-fidelity, fast, and have scalable architecture are essential to support autonomous vehicle ...TARDEC has attempted to develop a high-fidelity mobility simulation of an autonomous vehicle in an off-road scenario using integrated sensor...for Dynamic Semi- Autonomous Unmanned Ground Vehicles 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT

  2. The Dynamic Multi-objective Multi-vehicle Covering Tour Problem

    Science.gov (United States)

    2013-06-01

    Routing Problem VEGA Vector Evaluated Genetic Algorithm VRP Vehicle Routing Problem VRPTW Vehicle routing problem with time windows xiv THE DYNAMIC MULTI...the TSP, CTP and Vehicle Routing Problem ( VRP ). Reviews of work in this area include [16, 39, 89, 90]. Recent developments enabling real-time...version of the VRP . Jozefowiez, et al. [85] study a bi-objective CTP which minimizes the total route cost ( f1(R)) and the distance from the nodes to be

  3. Plug-in hybrid electric vehicles in dynamical energy markets

    NARCIS (Netherlands)

    Kessels, J.T.B.A.; Bosch, P.P.J. van den

    2008-01-01

    The plug-in hybrid electric vehicle allows vehicle propulsion from multiple internal power sources. Electric energy from the grid can be utilized by means of the plug-in connection. An on-line energy management (EM) strategy is proposed to minimize the costs for taking energy from each power source.

  4. Plug-in hybrid electric vehicles in dynamical energy markets

    NARCIS (Netherlands)

    Kessels, J.T.B.A.; Bosch, P.P.J. van den

    2008-01-01

    The plug-in hybrid electric vehicle allows vehicle propulsion from multiple internal power sources. Electric energy from the grid can be utilized by means of the plug-in connection. An on-line energy management (EM) strategy is proposed to minimize the costs for taking energy from each power source.

  5. Dynamical Modeling and Control Simulation of a Large Flexible Launch Vehicle

    Science.gov (United States)

    Du, Wei; Wie, Bong; Whorton, Mark

    2008-01-01

    This paper presents dynamical models of a large flexible launch vehicle. A complete set of coupled dynamical models of propulsion, aerodynamics, guidance and control, structural dynamics, fuel sloshing, and thrust vector control dynamics are described. Such dynamical models are used to validate NASA s SAVANT Simulink-based program which is being used for the preliminary flight control systems analysis and design of NASA s Ares-1 Crew Launch Vehicle. SAVANT simulation results for validating the performance and stability of an ascent phase autopilot system of Ares-1 are also presented.

  6. Experimental evaluation of optimal Vehicle Dynamic Control based on the State Dependent Riccati Equation technique

    NARCIS (Netherlands)

    Alirezaei, M.; Kanarachos, S.A.; Scheepers, B.T.M.; Maurice, J.P.

    2013-01-01

    Development and experimentally evaluation of an optimal Vehicle Dynamic Control (VDC) strategy based on the State Dependent Riccati Equation (SDRE) control technique is presented. The proposed nonlinear controller is based on a nonlinear vehicle model with nonlinear tire characteristics. A novel ext

  7. Experimental evaluation of optimal Vehicle Dynamic Control based on the State Dependent Riccati Equation technique

    NARCIS (Netherlands)

    Alirezaei, M.; Kanarachos, S.A.; Scheepers, B.T.M.; Maurice, J.P.

    2013-01-01

    Development and experimentally evaluation of an optimal Vehicle Dynamic Control (VDC) strategy based on the State Dependent Riccati Equation (SDRE) control technique is presented. The proposed nonlinear controller is based on a nonlinear vehicle model with nonlinear tire characteristics. A novel

  8. Dynamics of Braking Vehicles: From Coulomb Friction to Anti-Lock Braking Systems

    Science.gov (United States)

    Tavares, J. M.

    2009-01-01

    The dynamics of braking of wheeled vehicles is studied using the Coulomb approximation for the friction between road and wheels. The dependence of the stopping distance on the mass of the vehicle, on the number of its wheels and on the intensity of the braking torque is established. It is shown that there are two regimes of braking, with and…

  9. First demonstration of a vehicle mounted 250GHz real time passive imager

    Science.gov (United States)

    Mann, Chris

    2009-05-01

    This paper describes the design and performance of a ruggedized passive Terahertz imager, the frequency of operation is a 40GHz band centred around 250GHz. This system has been specifically targeted at vehicle mounted operation, outdoors in extreme environments. The unit incorporates temperature stabilization along with an anti-vibration chassis and is sealed to allow it to be used in a dusty environment. Within the system, a 250GHz heterodyne detector array is mated with optics and scanner to allow real time imaging out to 100 meters. First applications are envisaged to be stand-off, person borne IED detection to 30 meters but the unique properties in this frequency band present other potential uses such as seeing through smoke and fog. The possibility for use as a landing aid is discussed. A detailed description of the system design and video examples of typical imaging output will be presented.

  10. Development and Demonstration of a Low Cost Hybrid Drive Train for Medium and Heavy Duty Vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Strangas, Elias; Schock, Harold; Zhu, Guoming; Moran, Kevin; Ruckle, Trevor; Foster, Shanelle; Cintron-Rivera, Jorge; Tariq, Abdul; Nino-Baron, Carlos

    2011-04-30

    The DOE sponsored effort is part of a larger effort to quantify the efficiency of hybrid powertrain systems through testing and modeling. The focus of the DOE sponsored activity was the design, development and testing of hardware to evaluate the efficiency of the electrical motors relevant to medium duty vehicles. Medium duty hybrid powertrain motors and generators were designed, fabricated, setup and tested. The motors were a permanent magnet configuration, constructed at Electric Apparatus Corporation in Howell, Michigan. The purpose of this was to identify the potential gains in terms of fuel cost savings that could be realized by implementation of such a configuration. As the electric motors constructed were prototype designs, the scope of the project did not include calculation of the costs of mass production of the subject electrical motors or generator.

  11. Computer Simulation of Dynamic Interactions Between Vehicle and Long Span Box Girder Bridges

    Institute of Scientific and Technical Information of China (English)

    Lei Gong; Moe S.Cheung

    2008-01-01

    Moving vehicle loads,associated with roadway traffic can induce significant dynamic effects on the structural behaviours of bridges,especially for long-span bridges.The main objective of current research is to study traffic induced dynamic responses of long-span box-girder bridges.The finite element method has been employed in this study to obtain a three-dimensional mathematical model for the bridge system.For vehicle-bridge dynamic interaction analysis,the vehicle is modeled as a more realistic three-axle,six-wheel system,and the corresponding dynamic interaction equations have been derived.The bridge-vehicle inter- action is affected by many factors.The current study has been focused on such factors as:vehicle speed, vehicle damping ratio,multiple traffic lanes,mass ratio of vehicle and bridge,and dynamic characteristics of bridge.Case studies have been conducted to investigate these factors by using several box girder bridge examples including Confederation Bridge,the longest box girder bridge in the world.

  12. A refined and dynamic cellular automaton model for pedestrian-vehicle mixed traffic flow

    Science.gov (United States)

    Liu, Mianfang; Xiong, Shengwu

    2016-12-01

    Mixed traffic flow sharing the “same lane” and having no discipline on road is a common phenomenon in the developing countries. For example, motorized vehicles (m-vehicles) and nonmotorized vehicles (nm-vehicles) may share the m-vehicle lane or nm-vehicle lane and pedestrians may share the nm-vehicle lane. Simulating pedestrian-vehicle mixed traffic flow consisting of three kinds of traffic objects: m-vehicles, nm-vehicles and pedestrians, can be a challenge because there are some erratic drivers or pedestrians who fail to follow the lane disciplines. In the paper, we investigate various moving and interactive behavior associated with mixed traffic flow, such as lateral drift including illegal lane-changing and transverse crossing different lanes, overtaking and forward movement, and propose some new moving and interactive rules for pedestrian-vehicle mixed traffic flow based on a refined and dynamic cellular automaton (CA) model. Simulation results indicate that the proposed model can be used to investigate the traffic flow characteristic in a mixed traffic flow system and corresponding complicated traffic problems, such as, the moving characteristics of different traffic objects, interaction phenomenon between different traffic objects, traffic jam, traffic conflict, etc., which are consistent with the actual mixed traffic system. Therefore, the proposed model provides a solid foundation for the management, planning and evacuation of the mixed traffic flow.

  13. Dynamic Axle Load of an Automotive Vehicle When Driven on a Mobile Measurement Platform

    Directory of Open Access Journals (Sweden)

    Jagiełowicz-Ryznar C.

    2014-08-01

    Full Text Available An analysis of the dynamic axle load of an automotive vehicle (AV when it is driven on a mobile measurement platform is presented in this paper. During the ride, the time characteristic of the dynamic force N(t, acting on the axle, was recorded. The effect of the vehicle axle mass on the maximum dynamic force value and the dynamic coefficient were studied. On this basis it was attempted to calculate the total vehicle’s weight. Conclusions concerning the dynamic loads of the vehicle axles in relation to the reduced axle mass, were drawn. The optimal axle mass value, for which the dynamic coefficient reaches a minimum, was calculated

  14. A Dynamic Visualization Environment For The Design And Evaluation Of Automatic Vehicle Control Systems

    OpenAIRE

    Xu, Z.

    1995-01-01

    This document presents Dynamic Visualization, a project associated with the California PATH Program. The objective of the project is to develop a software which can animate automated highways, visualize the dynamics of automatic vehicles, and help the design and evaluation of automatic vehicle systems. This report summarizes the accomplishments of the project, describes the functions of the developed software, and provides an explanation of how to use the software.

  15. Dynamic simulation of urban hybrid electric vehicles; Dynamische Simulation von Stadthybridfahrzeugen

    Energy Technology Data Exchange (ETDEWEB)

    Winke, Florian; Bargende, Michael [Stuttgart Univ. (Germany). Inst. fuer Verbrennungsmotoren und Kraftfahrwesen (IVK)

    2013-09-15

    As a result of the rising requirements on the development process of modern vehicles, simulation models for the prediction of fuel efficiency have become an irreplaceable tool in the automotive industry. Especially for the design of hybrid electric drivetrains, the increasingly short development cycles can only be met by the use of efficient simulation models. At the IVK of the University of Stuttgart, different approaches to simulating the longitudinal dynamics of hybrid electric vehicles were analysed and compared within the presented project. The focus of the investigations was on urban operation. The objective was to develop a hybrid vehicle concept that allows an equitable comparison with pure battery electric vehicles. (orig.)

  16. Determining habitat quality for species that demonstrate dynamic habitat selection

    Science.gov (United States)

    Beerens, James; Frederick, Peter C; Noonburg, Erik G; Gawlik, Dale E.

    2015-01-01

    Determining habitat quality for wildlife populations requires relating a species' habitat to its survival and reproduction. Within a season, species occurrence and density can be disconnected from measures of habitat quality when resources are highly seasonal, unpredictable over time, and patchy. Here we establish an explicit link among dynamic selection of changing resources, spatio-temporal species distributions, and fitness for predictive abundance and occurrence models that are used for short-term water management and long-term restoration planning. We used the wading bird distribution and evaluation models (WADEM) that estimate (1) daily changes in selection across resource gradients, (2) landscape abundance of flocks and individuals, (3) conspecific foraging aggregation, and (4) resource unit occurrence (at fixed 400 m cells) to quantify habitat quality and its consequences on reproduction for wetland indicator species. We linked maximum annual numbers of nests detected across the study area and nesting success of Great Egrets (Ardea alba), White Ibises (Eudocimus albus), and Wood Storks (Mycteria americana) over a 20-year period to estimated daily dynamics of food resources produced by WADEM over a 7490 km2 area. For all species, increases in predicted species abundance in March and high abundance in April were strongly linked to breeding responses. Great Egret nesting effort and success were higher when birds also showed greater conspecific foraging aggregation. Synthesis and applications: This study provides the first empirical evidence that dynamic habitat selection processes and distributions of wading birds over environmental gradients are linked with reproductive measures over periods of decades. Further, predictor variables at a variety of temporal (daily-multiannual) resolutions and spatial (400 m to regional) scales effectively explained variation in ecological processes that change habitat quality. The process used here allows managers to develop

  17. Motion-mode energy method for vehicle dynamics analysis and control

    Science.gov (United States)

    Zhang, Nong; Wang, Lifu; Du, Haiping

    2014-01-01

    Vehicle motion and vibration control is a fundamental motivation for the development of advanced vehicle suspension systems. In a vehicle-fixed coordinate system, the relative motions of the vehicle between body and wheel can be classified into several dynamic stages based on energy intensity, and can be decomposed into sets of uncoupled motion-modes according to modal parameters. Vehicle motions are coupled, but motion-modes are orthogonal. By detecting and controlling the predominating vehicle motion-mode, the system cost and energy consumption of active suspensions could be reduced. A motion-mode energy method (MEM) is presented in this paper to quantify the energy contribution of each motion-mode to vehicle dynamics in real time. The control of motion-modes is prioritised according to the level of motion-mode energy. Simulation results on a 10 degree-of-freedom nonlinear full-car model with the magic-formula tyre model illustrate the effectiveness of the proposed MEM. The contribution of each motion-mode to the vehicle's dynamic behaviour is analysed under different excitation inputs from road irregularities, directional manoeuvres and braking. With the identified dominant motion-mode, novel cost-effective suspension systems, such as active reconfigurable hydraulically interconnected suspension, can possibly be used to control full-car motions with reduced energy consumption. Finally, discussion, conclusions and suggestions for future work are provided.

  18. THREE DIMENSIONAL MODELING AND DYNAMIC ANALYSIS OF FOUR-WHEEL-STEERING VEHICLES

    Institute of Scientific and Technical Information of China (English)

    胡海岩; 韩强

    2003-01-01

    The paper presents a nonlinear dynamic model of 9 degrees of freedom for four-wheelsteering vehicles. Compared with those in previous studies, this model includes the pitch and roll of the vehicle body, the motion of 4 wheels in the accelerating or braking process, the nonlinear coupling of vehicle body and unsprung part, as well as the air drag and wind effect. As a result, the model can be used for the analysis of various maneuvers of the four-wheel-steering vehicles. In addition, the previous models can be considered as a special case of this model. The paper gives some case studies for the dynamic performance of a four-wheel-steering vehicle under step input and saw-tooth input of steering angle applied on the front wheels, respectively.

  19. Experimental Evaluation of the Scale Model Method to Simulate Lunar Vehicle Dynamics

    Science.gov (United States)

    Johnson, Kyle; Asnani, Vivake; Polack, Jeff; Plant, Mark

    2016-01-01

    As compared to driving on Earth, the presence of lower gravity and uneven terrain on planetary bodies makes high speed driving difficult. In order to maintain ground contact and control vehicles need to be designed with special attention to dynamic response. The challenge of maintaining control on the Moon was evident during high speed operations of the Lunar Roving Vehicle (LRV) on Apollo 16, as at one point all four tires were off the ground; this event has been referred to as the Lunar Grand Prix. Ultimately, computer simulation should be used to examine these phenomena during the vehicle design process; however, experimental techniques are required for the validation and elucidation of key issues. The objectives of this study were to evaluate the methodology for developing a scale model of a lunar vehicle using similitude relationships and to test how vehicle configuration, six or eight wheel pods, and local tire compliance, soft or stiff, affect the vehicles dynamic performance. A wheel pod consists of a drive and steering transmission and wheel. The Lunar Electric Rover (LER), a human driven vehicle with a pressurized cabin, was selected as an example for which a scale model was built. The scaled vehicle was driven over an obstacle and the dynamic response was observed and then scaled to represent the full-size vehicle in lunar gravity. Loss of ground contact, in terms of vehicle travel distance with tires off the ground, was examined. As expected, local tire compliance allowed ground contact to be maintained over a greater distance. However, switching from a six-tire configuration to an eight-tire configuration with reduced suspension stiffness had a negative effect on ground contact. It is hypothesized that this was due to the increased number or frequency of impacts. The development and testing of this scale model provided practical lessons for future low-gravity vehicle development.

  20. Numerical methods in vehicle system dynamics: state of the art and current developments

    Science.gov (United States)

    Arnold, M.; Burgermeister, B.; Führer, C.; Hippmann, G.; Rill, G.

    2011-07-01

    Robust and efficient numerical methods are an essential prerequisite for the computer-based dynamical analysis of engineering systems. In vehicle system dynamics, the methods and software tools from multibody system dynamics provide the integration platform for the analysis, simulation and optimisation of the complex dynamical behaviour of vehicles and vehicle components and their interaction with hydraulic components, electronical devices and control structures. Based on the principles of classical mechanics, the modelling of vehicles and their components results in nonlinear systems of ordinary differential equations (ODEs) or differential-algebraic equations (DAEs) of moderate dimension that describe the dynamical behaviour in the frequency range required and with a level of detail being characteristic of vehicle system dynamics. Most practical problems in this field may be transformed to generic problems of numerical mathematics like systems of nonlinear equations in the (quasi-)static analysis and explicit ODEs or DAEs with a typical semi-explicit structure in the dynamical analysis. This transformation to mathematical standard problems allows to use sophisticated, freely available numerical software that is based on well approved numerical methods like the Newton-Raphson iteration for nonlinear equations or Runge-Kutta and linear multistep methods for ODE/DAE time integration. Substantial speed-ups of these numerical standard methods may be achieved exploiting some specific structure of the mathematical models in vehicle system dynamics. In the present paper, we follow this framework and start with some modelling aspects being relevant from the numerical viewpoint. The focus of the paper is on numerical methods for static and dynamic problems, including software issues and a discussion which method fits best for which class of problems. Adaptive components in state-of-the-art numerical software like stepsize and order control in time integration are

  1. Spinning Up Interest: Classroom Demonstrations of Rotating Fluid Dynamics

    Science.gov (United States)

    Aurnou, J.

    2005-12-01

    The complex relationship between rotation and its effect on fluid motions presents some of the most difficult and vexing concepts for both undergraduate and graduate level students to learn. We have found that student comprehension is greatly increased by the presentation of in-class fluid mechanics experiments. A relatively inexpensive experimental set-up consists of the following components: a record player, a wireless camera placed in the rotating frame, a tank of fluid, and food coloring. At my poster, I will use this set-up to carry out demonstrations that illustrate the Taylor-Proudman theorem, flow within the Ekman layer, columnar convection, and flow around high and low pressure centers. By sending the output of the wireless camera through an LCD projection system, such demonstrations can be carried out even for classes in large lecture halls.

  2. Development of Constraint Force Equation Methodology for Application to Multi-Body Dynamics Including Launch Vehicle Stage Seperation

    Science.gov (United States)

    Pamadi, Bandu N.; Toniolo, Matthew D.; Tartabini, Paul V.; Roithmayr, Carlos M.; Albertson, Cindy W.; Karlgaard, Christopher D.

    2016-01-01

    The objective of this report is to develop and implement a physics based method for analysis and simulation of multi-body dynamics including launch vehicle stage separation. The constraint force equation (CFE) methodology discussed in this report provides such a framework for modeling constraint forces and moments acting at joints when the vehicles are still connected. Several stand-alone test cases involving various types of joints were developed to validate the CFE methodology. The results were compared with ADAMS(Registered Trademark) and Autolev, two different industry standard benchmark codes for multi-body dynamic analysis and simulations. However, these two codes are not designed for aerospace flight trajectory simulations. After this validation exercise, the CFE algorithm was implemented in Program to Optimize Simulated Trajectories II (POST2) to provide a capability to simulate end-to-end trajectories of launch vehicles including stage separation. The POST2/CFE methodology was applied to the STS-1 Space Shuttle solid rocket booster (SRB) separation and Hyper-X Research Vehicle (HXRV) separation from the Pegasus booster as a further test and validation for its application to launch vehicle stage separation problems. Finally, to demonstrate end-to-end simulation capability, POST2/CFE was applied to the ascent, orbit insertion, and booster return of a reusable two-stage-to-orbit (TSTO) vehicle concept. With these validation exercises, POST2/CFE software can be used for performing conceptual level end-to-end simulations, including launch vehicle stage separation, for problems similar to those discussed in this report.

  3. Simulation modeling of wheeled vehicle dynamics on the stand "Roller"

    Directory of Open Access Journals (Sweden)

    G. O. Kotiev

    2014-01-01

    Full Text Available The tests are an integral part of the wheeled vehicle design, manufacturing, and operation. The need for their conducting arises from the research and experimental activities to assess the qualitative and quantitative characteristics of the vehicles in general, as well as the individual components and assemblies. It is obvious that a variety of design features of wheeled vehicles request a development of methods both for experimental studies and for creating the original bench equipment for these purposes.The main positive feature of bench tests of automotive engineering is a broad capability to control the combinations of traction loads, speed rates, and external input conditions. Here, the steady state conditions can be used for a long time, allowing all the necessary measurements to be made, including those with video and photo recording experiment.It is known that the benefits of test "M" type (using a roller dynamometer include a wide range of test modes, which do not depend on the climatic conditions, as well as a capability to use a computer-aided testing programs. At the same time, it is known that the main drawback of bench tests of full-size vehicle is that the tire rolling conditions on the drum mismatch to the real road pavements, which are difficult to simulate on the drum surface. This problem can be solved owing to wheeled vehicle tests at the benches "Roller" to be, in efficiency, the most preferable research method. The article gives a detailed presentation of developed at BMSTU approach to its solving.Problem of simulation mathematical modeling has been solved for the vehicle with the wheel formula 8 × 8, and individual wheel-drive.The simulation results have led to the conclusion that the proposed principle to simulate a vehicle rolling on a smooth non-deformable support base using a bench " Roller " by simulation modeling is efficient.

  4. Steering Dynamic Performance of an Electric Transmission Tracked Vehicle Based on Rotating Speed Control

    Institute of Scientific and Technical Information of China (English)

    SUN Feng-chun; CHEN Shu-yong; ZHANG Cheng-ning

    2006-01-01

    In order to analyze steering dynamic performance of an electric transmission tracked vehicle exactly, modern design theory and methodology-collaborative simulation and virtual prototype are applied. The 3-D multi-body dynamic model of full vehicle running gears and control system model are built based on the simulation platform on dynamic analysis software known as RecurDyn/Track-HM and control system analysis software known as Matlab/Simulink. Theory analysis and collaborative simulation of turning kinematic/dynamic performance in different velocity and turning radius are made. Comparing the test result with theory computation validates the correctness of the model. The method has instructional significance of solving the existent modeling problem, comprehension of turning performance and test debugging strategy,and also forms a new idea of research on dynamic characteristics for the electric transmission tracked vehicle's electric propulsion system.

  5. Analysis of Dynamic Stiffness Effect of Primary Suspension Helical Springs on Railway Vehicle Vibration

    Science.gov (United States)

    Sun, W.; Thompson, D. J.; Zhou, J.; Gong, D.

    2016-09-01

    Helical springs within the primary suspension are critical components for isolating the whole vehicle system from vibration generated at the wheel/rail contact. As train speeds increase, the frequency region of excitation becomes larger, and a simplified static stiffness can no longer represent the real stiffness property in a vehicle dynamic model. Coil springs in particular exhibit strong internal resonances, which lead to high vibration amplitudes within the spring itself as well as degradation of the vibration isolation. In this paper, the dynamic stiffness matrix method is used to determine the dynamic stiffness of a helical spring from a vehicle primary suspension. Results are confirmed with a finite element analysis. Then the spring dynamic stiffness is included within a vehicle-track coupled dynamic model of a high speed train and the effect of the dynamic stiffening of the spring on the vehicle vibration is investigated. It is shown that, for frequencies above about 50 Hz, the dynamic stiffness of the helical spring changes sharply. Due to this effect, the vibration transmissibility increases considerably which results in poor vibration isolation of the primary suspension. Introducing a rubber layer in series with the coil spring can attenuate this effect.

  6. Dynamic Modeling and Simulation of a Switched Reluctance Motor in a Series Hybrid Electric Vehicle

    Directory of Open Access Journals (Sweden)

    Siavash Sadeghi

    2010-04-01

    Full Text Available Dynamic behavior analysis of electric motors is required in order to accuratelyevaluate the performance, energy consumption and pollution level of hybrid electricvehicles. Simulation tools for hybrid electric vehicles are divided into steady state anddynamic models. Tools with steady-state models are useful for system-level analysiswhereas tools that utilize dynamic models give in-depth information about the behavior ofsublevel components. For the accurate prediction of hybrid electric vehicle performance,dynamic modeling of the motor and other components is necessary. Whereas the switchedreluctance machine is well suited for electric and hybrid electric vehicles, due to the simpleand rugged construction, low cost, and ability to operate over a wide speed range atconstant power, in this paper dynamic performance of the switched reluctance motor for eseries hybrid electric vehicles is investigated. For this purpose a switched reluctance motorwith its electrical drive is modeld and simulated first, and then the other components of aseries hybrid electric vehicle, such as battery, generator, internal combusion engine, andgearbox, are designed and linked with the electric motor. Finally a typical series hybridelectric vehicle is simulated for different drive cycles. The extensive simulation results showthe dynamic performance of SRM, battery, fuel consumption, and emissions.

  7. Dynamic Vehicle Detection via the Use of Magnetic Field Sensors.

    Science.gov (United States)

    Markevicius, Vytautas; Navikas, Dangirutis; Zilys, Mindaugas; Andriukaitis, Darius; Valinevicius, Algimantas; Cepenas, Mindaugas

    2016-01-19

    The vehicle detection process plays the key role in determining the success of intelligent transport management system solutions. The measurement of distortions of the Earth's magnetic field using magnetic field sensors served as the basis for designing a solution aimed at vehicle detection. In accordance with the results obtained from research into process modeling and experimentally testing all the relevant hypotheses an algorithm for vehicle detection using the state criteria was proposed. Aiming to evaluate all of the possibilities, as well as pros and cons of the use of anisotropic magnetoresistance (AMR) sensors in the transport flow control process, we have performed a series of experiments with various vehicles (or different series) from several car manufacturers. A comparison of 12 selected methods, based on either the process of determining the peak signal values and their concurrence in time whilst calculating the delay, or by measuring the cross-correlation of these signals, was carried out. It was established that the relative error can be minimized via the Z component cross-correlation and Kz criterion cross-correlation methods. The average relative error of vehicle speed determination in the best case did not exceed 1.5% when the distance between sensors was set to 2 m.

  8. Dynamic Vehicle Detection via the Use of Magnetic Field Sensors

    Directory of Open Access Journals (Sweden)

    Vytautas Markevicius

    2016-01-01

    Full Text Available The vehicle detection process plays the key role in determining the success of intelligent transport management system solutions. The measurement of distortions of the Earth’s magnetic field using magnetic field sensors served as the basis for designing a solution aimed at vehicle detection. In accordance with the results obtained from research into process modeling and experimentally testing all the relevant hypotheses an algorithm for vehicle detection using the state criteria was proposed. Aiming to evaluate all of the possibilities, as well as pros and cons of the use of anisotropic magnetoresistance (AMR sensors in the transport flow control process, we have performed a series of experiments with various vehicles (or different series from several car manufacturers. A comparison of 12 selected methods, based on either the process of determining the peak signal values and their concurrence in time whilst calculating the delay, or by measuring the cross-correlation of these signals, was carried out. It was established that the relative error can be minimized via the Z component cross-correlation and Kz criterion cross-correlation methods. The average relative error of vehicle speed determination in the best case did not exceed 1.5% when the distance between sensors was set to 2 m.

  9. Dynamic Vehicle Routing for Robotic Networks (Workshop Briefing Charts)

    Science.gov (United States)

    2010-06-29

    Computation: Numerical Methods. Athena Scientific, 1997 4 S. Mart́ınez, F. Bullo, J. Cortés, and E. Frazzoli. On synchronous robotic networks – Part I...29jun10 @ Baltimore, ACC 1 / 24 Motivation for Team Forming Group of vehicles monitoring a region Several different sensing modalities: electro- optical

  10. Dynamic behavior of gasoline fuel cell electric vehicles

    Science.gov (United States)

    Mitchell, William; Bowers, Brian J.; Garnier, Christophe; Boudjemaa, Fabien

    As we begin the 21st century, society is continuing efforts towards finding clean power sources and alternative forms of energy. In the automotive sector, reduction of pollutants and greenhouse gas emissions from the power plant is one of the main objectives of car manufacturers and innovative technologies are under active consideration to achieve this goal. One technology that has been proposed and vigorously pursued in the past decade is the proton exchange membrane (PEM) fuel cell, an electrochemical device that reacts hydrogen with oxygen to produce water, electricity and heat. Since today there is no existing extensive hydrogen infrastructure and no commercially viable hydrogen storage technology for vehicles, there is a continuing debate as to how the hydrogen for these advanced vehicles will be supplied. In order to circumvent the above issues, power systems based on PEM fuel cells can employ an on-board fuel processor that has the ability to convert conventional fuels such as gasoline into hydrogen for the fuel cell. This option could thereby remove the fuel infrastructure and storage issues. However, for these fuel processor/fuel cell vehicles to be commercially successful, issues such as start time and transient response must be addressed. This paper discusses the role of transient response of the fuel processor power plant and how it relates to the battery sizing for a gasoline fuel cell vehicle. In addition, results of fuel processor testing from a current Renault/Nuvera Fuel Cells project are presented to show the progress in transient performance.

  11. ELECTRICAL AND DYNAMIC BRAKING OF THE HYBRID VEHICLE ON THE ROADS WITH LOW COUPLING COEFFICIENT

    Directory of Open Access Journals (Sweden)

    Sitovskyi, O.

    2013-06-01

    Full Text Available There were carried out theoretical researches of the processes of the electrical and dynamic braking of the vehicle with hybrid power-plant on the roads with low coupling coefficient, it was proved the probability of the wheels blocking appearing, during electrical and dynamic braking.

  12. Validation of Microscopic Traffic Models Based on GPS Precise Measurement of Vehicle Dynamics

    Directory of Open Access Journals (Sweden)

    Tomas Apeltauer

    2013-04-01

    Full Text Available A necessary stage in the development of traffic models is model validation, where the developed model is verified by comparing its outputs with observed data. The most frequently used variables are average value of speed, flow intensity and flow density (during a selected period.It is possible to use these values for the calibration of macroscopic models, but one cannot always obtain a relevant microscopic dynamic model in this way. A typical use of the microsimulation models is the capacity assessment, where this sort of data (flow, speed and queues is considered to be standard and sufficient. However microsimulation is also increasingly being used for other assessments (e.g. noise and emissions where the correct representation of each vehicle’s acceleration and deceleration plays a crucial role. Another emerging area is the use of microsimulation to predict near-miss situations and conflicts to identify dangerous and accident prone locations. In such assessments the vehicle trajectory, distance from other vehicles as well as velocity and acceleration are very important.Additional source of data, which can be used to validate vehicle dynamics in microsimulation models, is the Global Positioning System (GPS that is able to determine vehicle position with centimeter accuracy.In this article we discuss validation of selected microscopic traffic models, based on the comparison of simulated vehicle dynamics with observed dynamic characteristics of vehicles recorded by the precise geodetic GPS equipment.

  13. Dynamics control of autonomous vehicle at driving limits and experiment on an autonomous formula racing car

    Science.gov (United States)

    Ni, Jun; Hu, Jibin

    2017-06-01

    In this paper, a novel dynamics controller for autonomous vehicle to simultaneously control it to the driving limits and follow the desired path is proposed. The dynamics controller consists of longitudinal and lateral controllers. In longitudinal controller, the G-G diagram is utilized to describe the driving and handling limits of the vehicle. The accurate G-G diagram is obtained based on phase plane approach and a nonlinear vehicle dynamic model with accurate tyre model. In lateral controller, the tyre cornering stiffness is estimated to improve the robustness of the controller. The stability analysis of the closed-looped error dynamics shows that the controller remains stable against parameters uncertainties in extreme condition such as tyre saturation. Finally, an electric autonomous Formula race car developed by the authors is used to validate the proposed controller. The autonomous driving experiment on an oval race track shows the efficiency and robustness of the proposed controller.

  14. Thermal Design and Analysis of the Supersonic Flight Dynamics Test Vehicle for the Low Density Supersonic Decelerator Project

    Science.gov (United States)

    Mastropietro, A. J.; Pauken, Michael; Sunada, Eric; Gray, Sandria

    2013-01-01

    The thermal design and analysis of the experimental Supersonic Flight Dynamics Test (SFDT) vehicle is presented. The SFDT vehicle is currently being designed as a platform to help demonstrate key technologies for NASA's Low Density Supersonic Decelerator (LDSD) project. The LDSD project is charged by NASA's Office of the Chief Technologist (OCT) with the task of advancing the state of the art in Mars Entry, Descent, and Landing (EDL) systems by developing and testing three new technologies required for landing heavier payloads on Mars. The enabling technologies under development consist of a large 33.5 meter diameter Supersonic Ringsail (SSRS) parachute and two different types of Supersonic Inflatable Aerodynamic Decelerator (SIAD) devices - a robotic class, SIAD-R, that inflates to a 6 meter diameter torus, and an exploration class, SIAD-E, that inflates to an 8 meter diameter isotensoid. As part of the technology development effort, the various elements of the new supersonic decelerator system must be tested in a Mars-like environment. This is currently planned to be accomplished by sending a series of SFDT vehicles into Earth's stratosphere. Each SFDT vehicle will be lifted to a stable float altitude by a large helium carrier balloon. Once at altitude, the SFDT vehicles will be released from their carrier balloon and spun up via spin motors to provide trajectory stability. An onboard third stage solid rocket motor will propel each test vehicle to supersonic flight in the upper atmosphere. After main engine burnout, each vehicle will be despun and testing of the deceleration system will begin: first an inflatable decelerator will be deployed around the aeroshell to increase the drag surface area, and then the large parachute will be deployed to continue the deceleration and return the vehicle back to the Earth's surface. The SFDT vehicle thermal system must passively protect the vehicle structure and its components from cold temperatures experienced during the

  15. Sizing Dynamic Wireless Charging for Light-Duty Electric Vehicles in Roadway Applications

    Energy Technology Data Exchange (ETDEWEB)

    Foote, Andrew P [ORNL; Ozpineci, Burak [ORNL; Chinthavali, Madhu Sudhan [ORNL; Li, Jan-Mou [ORNL

    2016-01-01

    Dynamic wireless charging is a possible cure for the range limitations seen in electric vehicles (EVs) once implemented in highways or city streets. The contribution of this paper is the use of experimental data to show that the expected energy gain from a dynamic wireless power transfer (WPT) system is largely a function of average speed, which allows the power level and number of coils per mile of a dynamic WPT system to be sized for the sustained operation of an EV. First, data from dynamometer testing is used to determine the instantaneous energy requirements of a light-duty EV. Then, experimental data is applied to determine the theoretical energy gained by passing over a coil as a function of velocity and power level. Related simulations are performed to explore possible methods of placing WPT coils within roadways with comparisons to the constant velocity case. Analyses with these cases demonstrate what system ratings are needed to meet the energy requirements of the EV. The simulations are also used to determine onboard energy storage requirements for each driving cycle.

  16. A Dynamic Algorithm for Facilitated Charging of Plug-In Electric Vehicles

    CERN Document Server

    Taheri, Nicole; Ye, Yinyu

    2011-01-01

    Plug-in Electric Vehicles (PEVs) are a rapidly developing technology that can reduce greenhouse gas emissions and change the way vehicles obtain power. PEV charging stations will most likely be available at home and at work, and occasionally be publicly available, offering flexible charging options. Ideally, each vehicle will charge during periods when electricity prices are relatively low, to minimize the cost to the consumer and maximize societal benefits. A Demand Response (DR) service for a fleet of PEVs could yield such charging schedules by regulating consumer electricity use during certain time periods, in order to meet an obligation to the market. We construct an automated DR mechanism for a fleet of PEVs that facilitates vehicle charging to ensure the demands of the vehicles and the market are met. Our dynamic algorithm depends only on the knowledge of a few hundred driving behaviors from a previous similar day, and uses a simple adjusted pricing scheme to instantly assign feasible and satisfactory c...

  17. Effects of automobile steering characteristics on driver vehicle system dynamics in regulation tasks

    Science.gov (United States)

    Mcruer, D. T.; Klein, R.

    1975-01-01

    A regulation task which subjected the automobile to a random gust disturbance which is countered by driver control action is used to study the effects of various automobile steering characteristics on the driver/vehicle system. The experiments used a variable stability automobile specially configured to permit insertion of the simulated gust disturbance and the measurement of the driver/vehicle system characteristics. Driver/vehicle system dynamics were measured and interpreted as an effective open loop system describing function. Objective measures of system bandwidth, stability, and time delays were deduced and compared. These objective measures were supplemented by driver ratings. A tentative optimum range of vehicle dynamics for the directional regulation task was established.

  18. A Based-Bottleneck Multiple Vehicle Type Dynamic Marginal Cost Model and Algorithm

    Directory of Open Access Journals (Sweden)

    Shuguang Li

    2012-09-01

    Full Text Available Single vehicle type dynamic marginal cost model is extended to multiple vehicle type dynamic one based on time-dependent multiple vehicle type queue analysis at a bottleneck. A dynamic link model is presented to model interactions between cars and trucks, given the link consists of two distinct segments. The first segment is the running segment on which cars (trucks run at their free-flow speeds and the second segment is the exit queue segment. A car or a truck is assumed to be a point without length. The class-specific pi parameter is used to transform the effect of truck into passenger car equivalents, so the exit flow of cars and trucks can be calculated according to the exit capacity of a bottleneck. The analytic expression of multiple vehicle type dynamic marginal cost function is deduced under congested and uncongested conditions. Then a heuristic algorithm is presented in solving multiple vehicle type dynamic queues, tolls under system optimum and user equilibrium conditions. The numerical example illustrates the simplicity and applicability of the proposed approach.

  19. Research, development, and demonstration of nickel-iron batteries for electric vehicle propulsion. Annual report, 1979

    Energy Technology Data Exchange (ETDEWEB)

    1980-06-01

    The program has progressed to the stage of evaluating full-sized (220 Ah) cells, multicell modules, and 22 kWh batteries. Nickel electrodes that display stable capacities of up to 24 Ah/plate (at C/3 drain rate) at design thickness (2.5 mm) in tests at 200/sup +/ test cycles. Iron electrodes of the composite-type are also delivering 24 Ah/plate (at C/3) at target thickness (1.0 mm). Iron plates are displaying capacity stability for 300/sup +/ test cycles in continuing 3 plate cell tests. Best finished cells are delivering 57 to 63 Wh/kg at C/3, based on cell weights of the finished cells, and in the actual designed cell volume. 6-cell module (6-1) performance has demonstrated 239 Ah, 1735 Wh, 53 WH/kg at the C/3 drain rate. This module is now being evaluated at the National Battery Test Laboratory. The 2 x 4 battery has been constructed, tested, and delivered for engineering test and evaluation. The battery delivered 22.5 kWh, as required (199 Ah discharge at 113 V-bar) at the C/3 drain rate. The battery has performed satisfactorily under dynamometer and constant current drain tests. Some cell problems, related to construction, necessitated changing 3 modules, but the battery is now ready for further testing. Reduction in nickel plate swelling (and concurrent stack electrolyte starvation), to improve cycling, is one area of major effort to reach the final battery objectives. Pasted nickel electrodes are showing promise in initial full-size cell tests and will continue to be evaluated in finished cells, along with other technology advancements. 30 figures, 14 tables.

  20. Development of Production-Intent Plug-In Hybrid Vehicle Using Advanced Lithium-Ion Battery Packs with Deployment to a Demonstration Fleet

    Energy Technology Data Exchange (ETDEWEB)

    No, author

    2013-09-29

    also completed four GM engineering development Buy-Off rides/milestones. The project included numerous engineering vehicle and systems development trips including extreme hot, cold and altitude exposure. The final fuel economy performance demonstrated met the objectives of the PHEV collaborative GM/DOE project. Charge depletion fuel economy of twice that of the non-PHEV model was demonstrated. The project team also designed, developed and tested a high voltage battery module concept that appears to be feasible from a manufacturability, cost and performance standpoint. The project provided important product development and knowledge as well as technological learnings and advancements that include multiple U.S. patent applications.

  1. Launch Vehicle Failure Dynamics and Abort Triggering Analysis

    Science.gov (United States)

    Hanson, John M.; Hill, Ashely D.; Beard, Bernard B.

    2011-01-01

    Launch vehicle ascent is a time of high risk for an on-board crew. There are many types of failures that can kill the crew if the crew is still on-board when the failure becomes catastrophic. For some failure scenarios, there is plenty of time for the crew to be warned and to depart, whereas in some there is insufficient time for the crew to escape. There is a large fraction of possible failures for which time is of the essence and a successful abort is possible if the detection and action happens quickly enough. This paper focuses on abort determination based primarily on data already available from the GN&C system. This work is the result of failure analysis efforts performed during the Ares I launch vehicle development program. Derivation of attitude and attitude rate abort triggers to ensure that abort occurs as quickly as possible when needed, but that false positives are avoided, forms a major portion of the paper. Some of the potential failure modes requiring use of these triggers are described, along with analysis used to determine the success rate of getting the crew off prior to vehicle demise.

  2. Adaptive representation for dynamic environment, vehicle, and mission complexity

    Science.gov (United States)

    Collier, Jack A.; Ricard, Benoit; Digney, Bruce L.; Cheng, David; Trentini, Michael; Beckman, Blake

    2004-09-01

    In order for an Unmanned Ground Vehicle (UGV) to operate effectively it must be able to perceive its environment in an accurate, robust and effective manner. This is done by creating a world representation which encompasses all the perceptual information necessary for the UGV to understand its surroundings. These perceptual needs are a function of the robots mobility characteristics, the complexity of the environment in which it operates, and the mission with which the UGV has been tasked. Most perceptual systems are designed with predefined vehicle, environmental, and mission complexity in mind. This can lead the robot to fail when it encounters a situation which it was not designed for since its internal representation is insufficient for effective navigation. This paper presents a research framework currently being investigated by Defence R&D Canada (DRDC), which will ultimately relieve robotic vehicles of this problem by allowing the UGV to recognize representational deficiencies, and change its perceptual strategy to alleviate these deficiencies. This will allow the UGV to move in and out of a wide variety of environments, such as outdoor rural to indoor urban, at run time without reprogramming. We present sensor and perception work currently being done and outline our research in this area for the future.

  3. Driver Steering Control and Full Vehicle Dynamics Study Based on a Nonlinear Three-Directional Coupled Heavy-Duty Vehicle Model

    Directory of Open Access Journals (Sweden)

    S. H. Li

    2014-01-01

    Full Text Available Under complicated driving situations, such as cornering brake, lane change, or barrier avoidance, the vertical, lateral, and longitudinal dynamics of a vehicle are coupled and interacted obviously. This work aims to propose the suitable vehicle and driver models for researching full vehicle dynamics in complicated conditions. A nonlinear three-directional coupled lumped parameters (TCLP model of a heavy-duty vehicle considering the nonlinearity of suspension damping and tire stiffness is built firstly. Then a modified preview driver model with nonlinear time delay is proposed and connected to the TCLP model to form a driver-vehicle closed-loop system. The presented driver-vehicle closed-loop system is evaluated during a double-lane change and compared with test data, traditional handling stability vehicle model, linear full vehicle model, and other driver models. The results show that the new driver model has better lane keeping performances than the other two driver models. In addition, the effects of driver model parameters on lane keeping performances, handling stability, ride comfort, and roll stability are discussed. The models and results of this paper are useful to enhance understanding the effects of driver behaviour on full vehicle dynamics.

  4. Analysis of limit forces on the vehicle wheels using an algorithm of Dynamic Square Method

    Science.gov (United States)

    Brukalski, M.

    2016-09-01

    This article presents a method named as Dynamic Square Method (DSM) used for dynamic analysis of a vehicle equipped with a four wheel drive system. This method allows determination of maximum (limit) forces acting on the wheels. Here, the maximum longitudinal forces acting on the wheels are assumed and then used to predict whether they can be achieved by a specific dynamic motion or whether the actual friction forces under a given wheel is large enough to transfer lateral forces. For the analysis of DSM a four wheel vehicle model is used. On the basis of this characteristic it is possible to determine the maximum longitudinal force acting on the wheels of the given axle depending on the lateral acceleration of the vehicle. The results of this analysis may be useful in the development of a control algorithm used for example in active differentials.

  5. Optimizing Gear Shifting Strategy for Off-Road Vehicle with Dynamic Programming

    Directory of Open Access Journals (Sweden)

    Xinxin Zhao

    2014-01-01

    Full Text Available Gear shifting strategy of vehicle is important aid for the acquisition of dynamic performance and high economy. A dynamic programming (DP algorithm is used to optimize the gear shifting schedule for off-road vehicle by using an objective function that weighs fuel use and trip time. The optimization is accomplished through discrete dynamic programming and a trade-off between trip time and fuel consumption is analyzed. By using concave and convex surface road as road profile, an optimal gear shifting strategy is used to control the longitudinal behavior of the vehicle. Simulation results show that the trip time can be reduced by powerful gear shifting strategy and fuel consumption can achieve high economy with economical gear shifting strategy in different initial conditions and route cases.

  6. Effect of rail corrugation on vertical dynamics of railway vehicle coupled with a track

    Institute of Scientific and Technical Information of China (English)

    Xuesong Jin; Kaiyun Wang; Zefeng Wen; Weihua Zhang

    2005-01-01

    The effect of rail corrugation on the vertical dynamics of railway vehicle coupled with a curved track is investigated in detail with a numerical method when a wheelset is steadily curving. In the calculation of rail corrugation we consider the combination of Kalker's rolling contact theory modified, a model of material loss on rail running surface, and a dynamics model of railway vehicle coupled with a curved track. In the establishment of the dynamic model, for simplicity, one fourth of the freight car without lateral motions,namely a wheelset and the equivalent one fourth freight car body above it, is considered. The Euler beam is used to model the rails and the track structure under the rails is replaced with equivalent springs, dampers and mass bodies. The numerical results show the great influence of the rail corrugation on the vibration of the parts of the vehicle and the track, and the some characters of rail corrugation in development.

  7. Research, development and demonstration of nickel-zinc batteries for electric vehicle propulsion. Annual report, 1979. [70 W/lb

    Energy Technology Data Exchange (ETDEWEB)

    1980-06-01

    This second annual report under Contract No. 31-109-39-4200 covers the period July 1, 1978 through August 31, 1979. The program demonstrates the feasibility of the nickel-zinc battery for electric vehicle propulsion. The program is divided into seven distinct but highly interactive tasks collectively aimed at the development and commercialization of nickel-zinc technology. These basic technical tasks are separator development, electrode development, product design and analysis, cell/module battery testing, process development, pilot manufacturing, and thermal management. A Quality Assurance Program has also been established. Significant progress has been made in the understanding of separator failure mechanisms, and a generic category of materials has been specified for the 300+ deep discharge (100% DOD) applications. Shape change has been reduced significantly. A methodology has been generated with the resulting hierarchy: cycle life cost, volumetric energy density, peak power at 80% DOD, gravimetric energy density, and sustained power. Generation I design full-sized 400-Ah cells have yielded in excess of 70 W/lb at 80% DOD. Extensive testing of cells, modules, and batteries is done in a minicomputer-based testing facility. The best life attained with electric vehicle-size cell components is 315 cycles at 100% DOD (1.0V cutoff voltage), while four-cell (approx. 6V) module performance has been limited to about 145 deep discharge cycles. The scale-up of processes for production of components and cells has progressed to facilitate component production rates of thousands per month. Progress in the area of thermal management has been significant, with the development of a model that accurately represents heat generation and rejection rates during battery operation. For the balance of the program, cycle life of > 500 has to be demonstrated in modules and full-sized batteries. 40 figures, 19 tables. (RWR)

  8. Dispersion analysis and linear error analysis capabilities of the space vehicle dynamics simulation program

    Science.gov (United States)

    Snow, L. S.; Kuhn, A. E.

    1975-01-01

    Previous error analyses conducted by the Guidance and Dynamics Branch of NASA have used the Guidance Analysis Program (GAP) as the trajectory simulation tool. Plans are made to conduct all future error analyses using the Space Vehicle Dynamics Simulation (SVDS) program. A study was conducted to compare the inertial measurement unit (IMU) error simulations of the two programs. Results of the GAP/SVDS comparison are presented and problem areas encountered while attempting to simulate IMU errors, vehicle performance uncertainties and environmental uncertainties using SVDS are defined. An evaluation of the SVDS linear error analysis capability is also included.

  9. Dynamic analysis of coupled vehicle-bridge system with uniformly variable speed

    Science.gov (United States)

    Wei-zhen, Li; Chang-ping, Chen; Yi-qi, Mao; Chang-zhao, Qian

    2016-09-01

    In this paper, a planar biaxial vehicle model with four degrees of freedom is presented based on spring-damping-mass system theory. By using Runge-Kutta method, the dynamic characteristics of a simply support bridge acting by moving vehicle with uniform variable speed are analyzed, and the effects of inertia force, relative acceleration and initial velocity are taken into consideration in the present research. The time-deflection response curves of the bridge under the variation of initial speed and acceleration are analyzed. Some valuable results are found which can provide a theoretical direction for the consideration of dynamical characteristics in design of bridge system.

  10. Analysis of the Dynamic Response in the Railway Vehicles to the Track Vertical Irregularities. Part I: The Theoretical Model and the Vehicle Response Functions

    OpenAIRE

    M. Dumitriu

    2015-01-01

    The paper herein focuses on the dynamic response of a two-bogie vehicle to the excitations derived from the track vertical irregularities. The symmetrical and antisymmetrical modes due from the bounce and pitch motions of the axles’ planes in the two bogies are being considered. The analysis of the dynamic response in the vehicle relies on the response functions in three reference points of the carbody, composed by means of these response functions to the symmetrical and antisymme...

  11. Workload Model Based Dynamic Adaptation of Social Internet of Vehicles

    Directory of Open Access Journals (Sweden)

    Kazi Masudul Alam

    2015-09-01

    Full Text Available Social Internet of Things (SIoT has gained much interest among different research groups in recent times. As a key member of a smart city, the vehicular domain of SIoT (SIoV is also undergoing steep development. In the SIoV, vehicles work as sensor-hub to capture surrounding information using the in-vehicle and Smartphone sensors and later publish them for the consumers. A cloud centric cyber-physical system better describes the SIoV model where physical sensing-actuation process affects the cloud based service sharing or computation in a feedback loop or vice versa. The cyber based social relationship abstraction enables distributed, easily navigable and scalable peer-to-peer communication among the SIoV subsystems. These cyber-physical interactions involve a huge amount of data and it is difficult to form a real instance of the system to test the feasibility of SIoV applications. In this paper, we propose an analytical model to measure the workloads of various subsystems involved in the SIoV process. We present the basic model which is further extended to incorporate complex scenarios. We provide extensive simulation results for different parameter settings of the SIoV system. The findings of the analyses are further used to design example adaptation strategies for the SIoV subsystems which would foster deployment of intelligent transport systems.

  12. Workload Model Based Dynamic Adaptation of Social Internet of Vehicles.

    Science.gov (United States)

    Alam, Kazi Masudul; Saini, Mukesh; El Saddik, Abdulmotaleb

    2015-09-15

    Social Internet of Things (SIoT) has gained much interest among different research groups in recent times. As a key member of a smart city, the vehicular domain of SIoT (SIoV) is also undergoing steep development. In the SIoV, vehicles work as sensor-hub to capture surrounding information using the in-vehicle and Smartphone sensors and later publish them for the consumers. A cloud centric cyber-physical system better describes the SIoV model where physical sensing-actuation process affects the cloud based service sharing or computation in a feedback loop or vice versa. The cyber based social relationship abstraction enables distributed, easily navigable and scalable peer-to-peer communication among the SIoV subsystems. These cyber-physical interactions involve a huge amount of data and it is difficult to form a real instance of the system to test the feasibility of SIoV applications. In this paper, we propose an analytical model to measure the workloads of various subsystems involved in the SIoV process. We present the basic model which is further extended to incorporate complex scenarios. We provide extensive simulation results for different parameter settings of the SIoV system. The findings of the analyses are further used to design example adaptation strategies for the SIoV subsystems which would foster deployment of intelligent transport systems.

  13. Time Series Analysis of Landslide Dynamics Using an Unmanned Aerial Vehicle (UAV

    Directory of Open Access Journals (Sweden)

    Darren Turner

    2015-02-01

    Full Text Available In this study, we used an Unmanned Aerial Vehicle (UAV to collect a time series of high-resolution images over four years at seven epochs to assess landslide dynamics. Structure from Motion (SfM was applied to create Digital Surface Models (DSMs of the landslide surface with an accuracy of 4–5 cm in the horizontal and 3–4 cm in the vertical direction. The accuracy of the co-registration of subsequent DSMs was checked and corrected based on comparing non-active areas of the landslide, which minimized alignment errors to a mean of 0.07 m. Variables such as landslide area and the leading edge slope were measured and temporal patterns were discovered. Volumetric changes of particular areas of the landslide were measured over the time series. Surface movement of the landslide was tracked and quantified with the COSI-Corr image correlation algorithm but without ground validation. Historical aerial photographs were used to create a baseline DSM, and the total displacement of the landslide was found to be approximately 6630 m3. This study has demonstrated a robust and repeatable algorithm that allows a landslide’s dynamics to be mapped and monitored with a UAV over a relatively long time series.

  14. A Constraint Embedding Approach for Complex Vehicle Suspension Dynamics

    Science.gov (United States)

    2015-04-24

    2015, Barcelona, Catalonia , Spain same number of degrees of freedom as the number of independent degrees of freedom for the loops they replace...13. SUPPLEMENTARY NOTES ECCOMAS Thematic Conference on Multibody Dynamics 2015, June 29-July 2, 2015, Barcelona, Catalonia , Spain 14. ABSTRACT See...Z39-18 ECCOMAS Thematic Conference on Multibody Dynamics June 29 - July 2, 2015, Barcelona, Catalonia , Spain A Constraint Embedding Approach for

  15. Ford/DOE sodium-sulfur battery electric vehicle development and demonstration. Phase I-1. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1979-01-01

    The results of Phase I-A analyses and design studies are presented. The objective of the Phase I-A effort was to evaluate the sodium-sulfur battery, in an existing conventional production automobile, as a potential power source for an electric vehicle. The Phase I-A work was divided into five (5) major sub-tasks as follows: vehicle specification sub-task; NaS battery packaging study sub-task; vehicle packaging layout sub-task; electrical system study sub-task; and system study sub-tasks covering performance and economy projections, powertrain and vehicle safety issues and thermal studies. The major results of the sodium-sulfur battery powered electric vehicle study program are: the Fiesta was chosen to be the production vehicle which would be modified into a 2-passenger, electric test bed vehicle powered by a NaS battery; the vehicle mission was defined to be a 2-passenger urban/suburban commuter vehicle capable of at least 100 miles range over the CVS driving cycle and a wide open throttle capability of 0 to 50 mph in 14 seconds, or less; powertrain component specifications were defined; powertrain control strategy has been selected; and a suitable test bed vehicle package scheme has been developed.

  16. Driving Control Research for Longitudinal Dynamics of Electric Vehicles with Independently Driven Front and Rear Wheels

    Directory of Open Access Journals (Sweden)

    Wei Liu

    2013-01-01

    Full Text Available This paper takes the electric off-road vehicle with separated driven axles as the research object. To solve the longitudinal dynamics driving control problems, vehicle dynamics model, and control strategies were studied and the corresponding simulation was carried out. An 8-DOF vehicle dynamics model with separated driven axles was built. The driving control strategies on the typical roads were put forward. The recognition algorithm of the typical road surfaces based on the wheels’ slip rates was proposed. And the two control systems were designed including the pedal opening degree adjustment control system based on PI algorithm and the interaxle torque distribution control system based on sliding mode control algorithm. The driving control flow of the proposed vehicle combining the pedal adjustment control system with the interaxle torque distribution control system was developed. And the driven control strategies for the typical roads were simulated. Simulation results show that the proposed drive control strategies can adapt to different typical road surfaces, limit the slip rates of the driving wheels within the stable zone, and ensure the vehicle driving safely and stably in accordance with the driver's intention.

  17. Robust control and linear parameter varying approaches application to vehicle dynamics

    CERN Document Server

    Gaspar, Peter; Bokor, József

    2013-01-01

    Vehicles are complex systems (non-linear, multi-variable) where the abundance of embedded controllers should ensure better security. This book aims at emphasizing the interest and potential of Linear Parameter Varying methods within the framework of vehicle dynamics, e.g.   ·          proposed control-oriented model, complex enough to handle some system non linearities but still simple for control or observer design,   ·          take into account the adaptability of the vehicle's response to driving situations, to the driver request and/or to the road sollicitations,   ·          manage interactions between various actuators to optimize the dynamic behavior of vehicles.   This book results from the 32th International Summer School in Automatic that held in Grenoble, France, in September 2011, where recent methods (based on robust control and LPV technics), then applied to the control of vehicle dynamics, have been presented. After some theoretical background and a view on so...

  18. Improved design of dynamic vibration absorber by using the inerter and its application in vehicle suspension

    Science.gov (United States)

    Shen, Yujie; Chen, Long; Yang, Xiaofeng; Shi, Dehua; Yang, Jun

    2016-01-01

    Inerter is a recently proposed mechanical element with two terminals. The novelty of this paper is to present the improved design which aims to add traditional dynamic vibration absorber to the vehicle body by using the inerter. Based on this background, a new vehicle suspension structure called ISD suspension, including the inerter, spring and damper has been created. A dual-mass vibration model including the ISD suspension is considered in this study. Parameters are obtained by using the genetic optimizing algorithm. The frequency-domain simulation confirms that the ISD suspension can effectively improve the damping performance of the suspension system, especially at the offset frequency of the vehicle body, which is consistent with the feature of the dynamic vibration absorber added to the vehicle body mass. At last, a prototype ball screw inerter has been designed and the bench test of a quarter-car model has been undertaken. Under the conditions of the random road input, the vehicle ride comfort evaluation of body acceleration RMS value decreases by 4% at most, the suspension deflection RMS value decreases by 16% at most, the tire dynamic load RMS value decreases by 6% at most. Power spectral density results also indicate that the ISD suspension has superior damping performance than passive suspension which proves that the proposed ISD suspension is deemed effective.

  19. Review on dynamics control of 4WID-4WIS electric vehicle

    Directory of Open Access Journals (Sweden)

    Xin LAI

    2016-08-01

    Full Text Available The four-wheel independent drive and four-wheel independent steering (4WID-4WIS vehicle has the advantages of short transmission chain, high efficiency, compact structure, and high maneuverability. The kinematics and dynamic control of the 4WID-4WIS vehicle are discussed, then key and difficult problems are refined. The distributed network control system is widely used in the vehicle control system, so that real-time and reliable control under non-ideal network is the research challenges, and hierarchical control method is a hot research topic. For the vehicle dynamics control method, the main research focuses on torque distribution method under one or more optimization objectives, and integrated control which harmonizes multi control subjects has become an important research direction. In order to solve the problem of steering mode static switching of the 4WID-4WIS vehicle, the study on the dynamic switching method based on redundant control degree of freedom is a new research direction.

  20. Explosion/Blast Dynamics for Constellation Launch Vehicles Assessment

    Science.gov (United States)

    Baer, Mel; Crawford, Dave; Hickox, Charles; Kipp, Marlin; Hertel, Gene; Morgan, Hal; Ratzel, Arthur; Cragg, Clinton H.

    2009-01-01

    An assessment methodology is developed to guide quantitative predictions of adverse physical environments and the subsequent effects on the Ares-1 crew launch vehicle associated with the loss of containment of cryogenic liquid propellants from the upper stage during ascent. Development of the methodology is led by a team at Sandia National Laboratories (SNL) with guidance and support from a number of National Aeronautics and Space Administration (NASA) personnel. The methodology is based on the current Ares-1 design and feasible accident scenarios. These scenarios address containment failure from debris impact or structural response to pressure or blast loading from an external source. Once containment is breached, the envisioned assessment methodology includes predictions for the sequence of physical processes stemming from cryogenic tank failure. The investigative techniques, analysis paths, and numerical simulations that comprise the proposed methodology are summarized and appropriate simulation software is identified in this report.

  1. A Study on the Dynamic Analysis of A Tracked Vehicle for Ocean Mining on the Deep Seabed

    Institute of Scientific and Technical Information of China (English)

    Hyung-suk HAN

    2003-01-01

    A study is presented on the dynamic analysis of a tracked vehicle for mining on the deep seabed of very soft soil. Equations for the interaction between the track and extremely soft seabed are employed to develop a track/soil interaction module called TVAS. The vehicle is modeled as a multibody dynamic system by the use of a multibody dynamic analysis program. The module developed is cooperated with the multibody dynamic analysis program with a user-defined subroutine. The dynamic behavior and the conceptual design of the mining vehicle on the deep seabed are investigated.

  2. Dynamic wheelset drive load of the railway vehicle caused by short-circuit motor moment

    Directory of Open Access Journals (Sweden)

    Zeman V.

    2009-12-01

    Full Text Available The paper deals with mathematical modelling of dynamic response of the railway vehicle wheelset drives caused by short-circuit traction motor torque. The individual wheelset drive with hollow graduated shaft is one of subsystems of the two-axled vehicle bogie with two wheelset drives. The model respects the viscoelastic suspension of the both engine stators with gear housings mounted on the bogie frame and all the other couplings among bogie drive components. The dynamic response is investigated in dependence on longitudinal creepage and forward velocity of the vehicle at the moment of the sudden short-circuit in one asynchronous traction motor. The method is applied to bogie of the electric locomotive developed for speed about 200 km/h by the company ŠKODA TRANSPORTATION, s. r. o. The wheelset drive vibration is confronted with stability conditions of the whole bogie.

  3. Experiential Learning in Vehicle Dynamics Education via Motion Simulation and Interactive Gaming

    Directory of Open Access Journals (Sweden)

    Kevin Hulme

    2009-01-01

    Full Text Available Creating active, student-centered learning situations in postsecondary education is an ongoing challenge for engineering educators. Contemporary students familiar with visually engaging and fast-paced games can find traditional classroom methods of lecture and guided laboratory experiments limiting. This paper presents a methodology that incorporates driving simulation, motion simulation, and educational practices into an engaging, gaming-inspired simulation framework for a vehicle dynamics curriculum. The approach is designed to promote active student participation in authentic engineering experiences that enhance learning about road vehicle dynamics. The paper presents the student use of physical simulation and large-scale visualization to discover the impact that design decisions have on vehicle design using a gaming interface. The approach is evaluated using two experiments incorporated into a sequence of two upper level mechanical engineering courses.

  4. Dynamic Reaction Figures: An Integrative Vehicle for Understanding Chemical Reactions

    Science.gov (United States)

    Schultz, Emeric

    2008-01-01

    A highly flexible learning tool, referred to as a dynamic reaction figure, is described. Application of these figures can (i) yield the correct chemical equation by simply following a set of menu driven directions; (ii) present the underlying "mechanism" in chemical reactions; and (iii) help to solve quantitative problems in a number of different…

  5. Time series analysis of landslide dynamics using an Unmanned Aerial Vehicle (UAV)

    NARCIS (Netherlands)

    Turner, Darren; Lucieer, Arko; de Jong, Steven M.

    2015-01-01

    In this study, we used an Unmanned Aerial Vehicle (UAV) to collect a time series of high-resolution images over four years at seven epochs to assess landslide dynamics. Structure from Motion (SfM) was applied to create Digital Surface Models (DSMs) of the landslide surface with an accuracy of 4-5 cm

  6. Dynamic characteristics of hydraulic power steering system with accumulator in load-haul-dump vehicle

    Institute of Scientific and Technical Information of China (English)

    杨忠炯; 何清华; 柳波

    2004-01-01

    Using hydraulic power steering system of model EIMCO 922 load-haul-dump vehicle as a simulation example, the dynamic characteristics of hydraulic power steering system in load-haul-dump vehicle were simulated and discussed with SIMULINK software and hydraulic control theory. The results show that the dynamic characteristics of hydraulic power steering system are improved obviously by using bladder accumulator, the hydraulic power steering system of model EIMCO 922 load-haul-dump vehicle generates vibration at the initial stage under the normal steering condition of pulse input, and its static response time is 0.25 s shorter than that without bladder accumulator. Under the normal steering working condition, the capacity of steering accumulator for absorbing pulse is directly proportional to the cross section area of connecting pipeline, and inversely proportional to the length of connecting pipeline. At the same time, the precharge pressure of nitrogen in steering accumulator should be 60%- 80% of the rated minimum working pressure of hydraulic power steering system. Under the abnormal steering working condition, the steering cylinder piston may obtain higher motion velocity, and the dynamic response velocity of hydraulic power steering system can be increased by reducing the pressure drop of hydraulic pipelines between the accumulator and steering cylinder and by increasing the rated pressure of hydraulic power steering system, but the dynamic characteristics of hydraulic power steering system in load-haul-dump vehicle have nothing to do with the precharge pressure of nitrogen in steering accumulator.

  7. Time series analysis of landslide dynamics using an Unmanned Aerial Vehicle (UAV)

    NARCIS (Netherlands)

    Turner, Darren; Lucieer, Arko; de Jong, Steven M.|info:eu-repo/dai/nl/120221306

    2015-01-01

    In this study, we used an Unmanned Aerial Vehicle (UAV) to collect a time series of high-resolution images over four years at seven epochs to assess landslide dynamics. Structure from Motion (SfM) was applied to create Digital Surface Models (DSMs) of the landslide surface with an accuracy of 4-5 cm

  8. Reliable fuzzy H∞ control for active suspension of in-wheel motor driven electric vehicles with dynamic damping

    Science.gov (United States)

    Shao, Xinxin; Naghdy, Fazel; Du, Haiping

    2017-03-01

    A fault-tolerant fuzzy H∞ control design approach for active suspension of in-wheel motor driven electric vehicles in the presence of sprung mass variation, actuator faults and control input constraints is proposed. The controller is designed based on the quarter-car active suspension model with a dynamic-damping-in-wheel-motor-driven-system, in which the suspended motor is operated as a dynamic absorber. The Takagi-Sugeno (T-S) fuzzy model is used to model this suspension with possible sprung mass variation. The parallel-distributed compensation (PDC) scheme is deployed to derive a fault-tolerant fuzzy controller for the T-S fuzzy suspension model. In order to reduce the motor wear caused by the dynamic force transmitted to the in-wheel motor, the dynamic force is taken as an additional controlled output besides the traditional optimization objectives such as sprung mass acceleration, suspension deflection and actuator saturation. The H∞ performance of the proposed controller is derived as linear matrix inequalities (LMIs) comprising three equality constraints which are solved efficiently by means of MATLAB LMI Toolbox. The proposed controller is applied to an electric vehicle suspension and its effectiveness is demonstrated through computer simulation.

  9. A Damage Detection Algorithm Utilizing Dynamic Displacement of Bridge under Moving Vehicle

    Directory of Open Access Journals (Sweden)

    Zhen Sun

    2016-01-01

    Full Text Available A damage detection method is proposed, which utilizes dynamic displacement of bridge structures under moving vehicle. The problem is first elaborated with closed-form solution of dynamic displacement, which is decomposed into quasi-static component and dynamic component. Dynamic curvature is defined as second derivative of the dynamic displacement for detecting damage location and estimating damage extent. Damage is modeled by local reduction of stiffness in this paper. Numerical study was conducted on a simply supported beam to verify the proposed method. Vehicle model is analyzed with Newmark’s method using Matlab to obtain the contact force acting on the bridge. Beam model is established in commercial finite element software ABAQUS. The effects of road surface roughness and vehicle-bridge interaction are both considered in the analysis. In order to identify damage location and extent, dynamic curvature was calculated with midspan displacement. Parametric study on measurement noise level, damage location, damage extent, and multiple damage cases is performed, and the analysis results show both reliability and efficacy of this method in damage detection of bridge structures. At last, conclusions are drawn for its application to bridges in engineering practice.

  10. Research, development, and demonstration of nickel-zinc batteries for electric vehicle propulsion. Annual report for 1980

    Energy Technology Data Exchange (ETDEWEB)

    1981-03-01

    Progress in the development of nickel-zinc batteries for electric vehicles is reported. Information is presented on nickel electrode preparation and testing; zinc electrode preparation with additives and test results; separator development and the evaluation of polymer-blend separator films; sealed Ni-Zn cells; and the optimization of electric vehicle-type Ni-Zn cells. (LCL)

  11. Adaptive Real-Time Estimation on Road Disturbances Properties Considering Load Variation via Vehicle Vertical Dynamics

    Directory of Open Access Journals (Sweden)

    Wuhui Yu

    2013-01-01

    Full Text Available Vehicle dynamics are directly dependent on tire-road contact forces and torques which are themselves dependent on the wheels’ load and tire-road friction characteristics. An acquisition of the road disturbance property is essential for the enhancement of vehicle suspension control systems. This paper focuses on designing an adaptive real-time road profile estimation observer considering load variation via vehicle vertical dynamics. Firstly, a road profile estimator based on a linear Kalman filter is proposed, which has great advantages on vehicle online control. Secondly, to minimize the estimation errors, an online identification system based on the Recursive Least-Squares Estimation is applied to estimate sprung mass, which is used to refresh the system matrix of the adaptive observer to improve the road estimation efficiency. Last, for mining road category from the estimated various road profile sequencse, a road categorizer considering road frequency and amplitude simultaneously is approached and its efficiency is validated via numerical simulations, in which the road condition is categorized into six special ranges, and this road detection strategy can provide the suspension control system with a better compromise for the vehicle ride comfort, handling, and safety performance.

  12. The science of vehicle dynamics handling, braking, and ride of road and race cars

    CERN Document Server

    Guiggiani, Massimo

    2014-01-01

    Vehicle dynamics is often perceived as a quite intuitive subject. As a matter of fact, lots of people are able to drive a car. Nevertheless, without a rigorous mathematical formulation it is very difficult to truly understand the physical phenomena involved in the motion of a road vehicle. In this book, mathematical models of vehicles are developed, always paying attention to state the relevant assumptions and to provide explanations for each step. This approach allows for a deep, yet simple, analysis of the dynamics of vehicles, without having to resort to foggy concepts. The reader will soon achieve a clear understanding of the subject, which will be of great help both in dealing with the challenges of designing and testing new vehicles and in tackling new research topics. The book covers handling and performance of both road and race cars. A new approach, called MAP (Map of Achievable Performance), is presented and thoroughly discussed. It provides a global and intuitive picture of the handling features of...

  13. Effect Analysis of Vehicle System Parameters on Dynamic Response of Pavement

    Directory of Open Access Journals (Sweden)

    Rong-xia Xia

    2015-01-01

    Full Text Available In order to study the damage of a semirigid pavement under vehicle loads with varied parameters, the random dynamic loads applied on the pavement by a running vehicle were computed with two degrees of freedom, quarter-vehicle model, and then a three-dimensional finite element analysis model of semirigid asphalt pavement was established. With the peak stress index of each pavement layer, the effect of varied vehicle parameters on pavement response was studied. The results indicated that the stress wave frequency of each pavement layer was similar to that of the dynamic random load, and, with increased pavement depth, the wave effect decreased. The pavement response increased with increased suspension stiffness and tire stiffness and decreased with increased suspension damping and tire damping. Furthermore, compared to the stiffness, the response variation induced by the damping was orders of magnitude lower. Compared with the traditional time response analysis method, the peak response analysis of the pavement structure was more scientific, rational, and intuitive, which could be useful for the study of vehicle-pavement interaction and road damage.

  14. Dynamic Analysis of Horizontally Curved Thin-Walled Box-Girder Bridge due to Moving Vehicle

    Directory of Open Access Journals (Sweden)

    K. Nallasivam

    2007-01-01

    Full Text Available The impact on curved box-girder bridges due to vehicle moving across rough bridge deck have been analyzed using bridge-vehicle coupled dynamics. The bridge deck unevenness has been assumed to be a homogeneous random process in space specified by a PSD function. The analysis incorporates the effect of centrifugal forces due to vehicle moving on curved bridge. The curved box-girder bridge has been numerically modeled using computationally efficient thin-walled box-beam finite elements which take into account the torsional warping, distortion and distortional warping, that are important features of thin-walled box girders. Rigid vehicle with longitudinal and transverse input to the wheels giving rise to heave-pitch-roll degrees of freedom has been considered. The theoretical bridge model used in simulation study has been validated by a free vibration experiment using impact excitation. The impact factors for several response parameters such as bending moment, shear force, torsional moment, torsional bi-moment, distortional moment, distortional bi-moment and vertical deflections have been obtained for various bridge-vehicle parameters. Both constant velocity and forward acceleration of the vehicle have been considered to examine impact factor. The results highlighted that the impact factors of a curved box girder bridge corresponding to torsion, distortion and their corresponding bimoments have been observed to be generally very high, while those of the other responses are also relatively higher than that of corresponding straight box girder bridge.

  15. On-demand high-capacity ride-sharing via dynamic trip-vehicle assignment.

    Science.gov (United States)

    Alonso-Mora, Javier; Samaranayake, Samitha; Wallar, Alex; Frazzoli, Emilio; Rus, Daniela

    2017-01-17

    Ride-sharing services are transforming urban mobility by providing timely and convenient transportation to anybody, anywhere, and anytime. These services present enormous potential for positive societal impacts with respect to pollution, energy consumption, congestion, etc. Current mathematical models, however, do not fully address the potential of ride-sharing. Recently, a large-scale study highlighted some of the benefits of car pooling but was limited to static routes with two riders per vehicle (optimally) or three (with heuristics). We present a more general mathematical model for real-time high-capacity ride-sharing that (i) scales to large numbers of passengers and trips and (ii) dynamically generates optimal routes with respect to online demand and vehicle locations. The algorithm starts from a greedy assignment and improves it through a constrained optimization, quickly returning solutions of good quality and converging to the optimal assignment over time. We quantify experimentally the tradeoff between fleet size, capacity, waiting time, travel delay, and operational costs for low- to medium-capacity vehicles, such as taxis and van shuttles. The algorithm is validated with ∼3 million rides extracted from the New York City taxicab public dataset. Our experimental study considers ride-sharing with rider capacity of up to 10 simultaneous passengers per vehicle. The algorithm applies to fleets of autonomous vehicles and also incorporates rebalancing of idling vehicles to areas of high demand. This framework is general and can be used for many real-time multivehicle, multitask assignment problems.

  16. On-demand high-capacity ride-sharing via dynamic trip-vehicle assignment

    Science.gov (United States)

    Alonso-Mora, Javier; Samaranayake, Samitha; Wallar, Alex; Frazzoli, Emilio; Rus, Daniela

    2017-01-01

    Ride-sharing services are transforming urban mobility by providing timely and convenient transportation to anybody, anywhere, and anytime. These services present enormous potential for positive societal impacts with respect to pollution, energy consumption, congestion, etc. Current mathematical models, however, do not fully address the potential of ride-sharing. Recently, a large-scale study highlighted some of the benefits of car pooling but was limited to static routes with two riders per vehicle (optimally) or three (with heuristics). We present a more general mathematical model for real-time high-capacity ride-sharing that (i) scales to large numbers of passengers and trips and (ii) dynamically generates optimal routes with respect to online demand and vehicle locations. The algorithm starts from a greedy assignment and improves it through a constrained optimization, quickly returning solutions of good quality and converging to the optimal assignment over time. We quantify experimentally the tradeoff between fleet size, capacity, waiting time, travel delay, and operational costs for low- to medium-capacity vehicles, such as taxis and van shuttles. The algorithm is validated with ∼3 million rides extracted from the New York City taxicab public dataset. Our experimental study considers ride-sharing with rider capacity of up to 10 simultaneous passengers per vehicle. The algorithm applies to fleets of autonomous vehicles and also incorporates rebalancing of idling vehicles to areas of high demand. This framework is general and can be used for many real-time multivehicle, multitask assignment problems. PMID:28049820

  17. Analysis of dynamic requirements for fuel cell systems for vehicle applications

    Science.gov (United States)

    Pischinger, Stefan; Schönfelder, Carsten; Ogrzewalla, Jürgen

    Conventional vehicles with internal combustion engines, as well as battery powered electric vehicles, achieve one of the most important customer requirements; achieving extremely short response times to load changes. Also, fast acceleration times from a cold start to full power in the range of seconds are practicable. New fuel cell-based propulsion systems, as well as auxiliary power units, have to fulfill the same demands to become competitive. This includes heating-up the system to operating temperature as well as the control strategy for start-up. An additional device to supply starting air is necessary, if the compressor motor can only be operated with fuel cell voltage. Since the system components (for example, the air supply or the fuel supply) are not mechanically coupled, as is the case with conventional internal combustion engines, these components have to be controlled by different sensors and actuators. This can be an advantage in optimizing the system, but it also can represent an additional challenge. This paper describes the fuel cell system requirements regarding transient operation and their dependence on system structure. In particular, the requirements for peripheral components such as air supply, fuel supply and the balance of heat in a fuel cell system are examined. Furthermore, the paper outlines the necessity of an electric storage device and its resultant capacity, which will enable faster load changes. Acceleration and deceleration of the vehicle are accomplished through the use of the electric storage device, while the fuel cell system only has to deliver the mean power consumption without higher load peaks. On the basis of system simulation, different concepts are evaluated for use as a propulsion system or APU and, then, critical components are identified. The effects of advanced control strategies regarding the dynamic behavior of the system are demonstrated. Technically, a fuel cell system could be a viable propulsion system alternative

  18. Analysis of dynamic requirements for fuel cell systems for vehicle applications

    Energy Technology Data Exchange (ETDEWEB)

    Pischinger, Stefan; Schoenfelder, Carsten [Institute for Combustion Engines, RWTH Aachen University, Aachen (Germany); Ogrzewalla, Juergen [FEV Motorentechnik GmbH, Aachen (Germany)

    2006-03-21

    Conventional vehicles with internal combustion engines, as well as battery powered electric vehicles, achieve one of the most important customer requirements; achieving extremely short response times to load changes. Also, fast acceleration times from a cold start to full power in the range of seconds are practicable. New fuel cell-based propulsion systems, as well as auxiliary power units, have to fulfill the same demands to become competitive. This includes heating-up the system to operating temperature as well as the control strategy for start-up. An additional device to supply starting air is necessary, if the compressor motor can only be operated with fuel cell voltage. Since the system components (for example, the air supply or the fuel supply) are not mechanically coupled, as is the case with conventional internal combustion engines, these components have to be controlled by different sensors and actuators. This can be an advantage in optimizing the system, but it also can represent an additional challenge. This paper describes the fuel cell system requirements regarding transient operation and their dependence on system structure. In particular, the requirements for peripheral components such as air supply, fuel supply and the balance of heat in a fuel cell system are examined. Furthermore, the paper outlines the necessity of an electric storage device and its resultant capacity, which will enable faster load changes. Acceleration and deceleration of the vehicle are accomplished through the use of the electric storage device, while the fuel cell system only has to deliver the mean power consumption without higher load peaks. On the basis of system simulation, different concepts are evaluated for use as a propulsion system or APU and, then, critical components are identified. The effects of advanced control strategies regarding the dynamic behavior of the system are demonstrated. Technically, a fuel cell system could be a viable propulsion system alternative

  19. Evaluation of logistic and economic impacts of hybrid vehicle propulsion/microgrid concepts: Demonstration of LOCSS applied to HE HMMWV in future unit of action

    Science.gov (United States)

    Farrell, Michael; Tiberi, Lisa; Burns, Joseph; Udvare, Thomas B.

    2006-05-01

    Computer models have been developed and used to predict the performance of vehicles equipped with advanced fuel and power train technologies such as hybrid electric or fuel cells. However, simulations that describe the interaction of the vehicle with the rest of the vehicle fleet and infrastructure are just emerging. This paper documents the results of an experiment to demonstrate the utility of these types of simulations. The experiment examined the business case of fielding hybrid electric, high-mobility multipurpose wheeled vehicles (HE HMMWVs) in a future Army organization. The hypothesis was that fielding HE vehicles would significantly reduce fuel consumption due to the economy offered by the HE technology and reducing the number of generators as a result of using the vehicles to generate electrical power. The Logistical and Combat Systems Simulation (LOCSS) was used to estimate differences in fuel consumption and associated equipment during a 72-hour operation with and without HE HMMWVs. There was a 25 percent reduction in fuel consumption over the systems examined. However, due to the relatively low density of the HE vehicles in the organization, the total difference in fuel consumption was not operationally significant; and the savings in fuel costs did not overcome the additional procurement costs over a twenty-year life cycle.

  20. Condition-based dynamic maintenance operations planning and grouping. Application to commercial heavy vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Bouvard, K., E-mail: keomany.bouvard@volvo.co [Volvo Technology, 99 route de Lyon, 69806 Saint Priest cedex (France); Laboratoire d' Automatique de Genie Informatique et Signal - FRE3303 - Polytech' Lille, 59655 Villeneuve d' Ascq (France); Artus, S., E-mail: samuel.artus@volvo.co [Volvo Technology, 99 route de Lyon, 69806 Saint Priest cedex (France); Berenguer, C., E-mail: christophe.berenguer@utt.f [Universite de technologie de Troyes - Institut Charles Delaunay and UMR CNRS 6279 - 12, rue Marie Curie, BP2060, 10010 Troyes cedex (France); Cocquempot, V., E-mail: vincent.cocquempot@univ-lille1.f [Laboratoire d' Automatique de Genie Informatique et Signal - FRE3303 - Polytech' Lille, 59655 Villeneuve d' Ascq (France)

    2011-06-15

    This paper aims at presenting a method to optimize the maintenance planning for a commercial heavy vehicle. Such a vehicle may be considered as a multi-components system. Grouping maintenance operations related to each component reduces the global maintenance cost of the system. Classically, the optimization problem is solved using a priori reliability characteristics of components. Two types of methods may be used, i.e. static or dynamic methods. Static methods provide a fixed maintenance planning, whereas dynamic methods redefine the groups of maintenance operations at each decision time. Dynamic procedures can incorporate component information such as component states or detected failures. For deteriorating systems, reliability characteristics of each component may be estimated thanks to deterioration models and may be updated when a degradation measure is available. This additional information on degradation features allows to better follow the real state of each component and to improve the maintenance planning.

  1. Vehicle Sliding Mode Control with Adaptive Upper Bounds: Static versus Dynamic Allocation to Saturated Tire Forces

    Directory of Open Access Journals (Sweden)

    Ali Tavasoli

    2012-01-01

    Full Text Available Nonlinear vehicle control allocation is achieved through distributing the task of vehicle control among individual tire forces, which are constrained to nonlinear saturation conditions. A high-level sliding mode control with adaptive upper bounds is considered to assess the body yaw moment and lateral force for the vehicle motion. The proposed controller only requires the online adaptation of control gains without acquiring the knowledge of upper bounds on system uncertainties. Static and dynamic control allocation approaches have been formulated to distribute high-level control objectives among the system inputs. For static control allocation, the interior-point method is applied to solve the formulated nonlinear optimization problem. Based on the dynamic control allocation method, a dynamic update law is derived to allocate vehicle control to tire forces. The allocated tire forces are fed into a low-level control module, where the applied torque and active steering angle at each wheel are determined through a slip-ratio controller and an inverse tire model. Computer simulations are used to prove the significant effects of the proposed control allocation methods on improving the stability and handling performance. The advantages and limitations of each method have been discussed, and conclusions have been derived.

  2. A New Model of Stopping Sight Distance of Curve Braking Based on Vehicle Dynamics

    Directory of Open Access Journals (Sweden)

    Rong-xia Xia

    2016-01-01

    Full Text Available Compared with straight-line braking, cornering brake has longer braking distance and poorer stability. Therefore, drivers are more prone to making mistakes. The braking process and the dynamics of vehicles in emergency situations on curves were analyzed. A biaxial four-wheel vehicle was simplified to a single model. Considering the braking process, dynamics, force distribution, and stability, a stopping sight distance of the curve braking calculation model was built. Then a driver-vehicle-road simulation platform was built using multibody dynamic software. The vehicle test of brake-in-turn was realized in this platform. The comparison of experimental and calculated values verified the reliability of the computational model. Eventually, the experimental values and calculated values were compared with the stopping sight distance recommended by the Highway Route Design Specification (JTGD20-2006; the current specification of stopping sight distance does not apply to cornering brake sight distance requirements. In this paper, the general values and limits of the curve stopping sight distance are presented.

  3. CFD based aerodynamic modeling to study flight dynamics of a flapping wing micro air vehicle

    Science.gov (United States)

    Rege, Alok Ashok

    The demand for small unmanned air vehicles, commonly termed micro air vehicles or MAV's, is rapidly increasing. Driven by applications ranging from civil search-and-rescue missions to military surveillance missions, there is a rising level of interest and investment in better vehicle designs, and miniaturized components are enabling many rapid advances. The need to better understand fundamental aspects of flight for small vehicles has spawned a surge in high quality research in the area of micro air vehicles. These aircraft have a set of constraints which are, in many ways, considerably different from that of traditional aircraft and are often best addressed by a multidisciplinary approach. Fast-response non-linear controls, nano-structures, integrated propulsion and lift mechanisms, highly flexible structures, and low Reynolds aerodynamics are just a few of the important considerations which may be combined in the execution of MAV research. The main objective of this thesis is to derive a consistent nonlinear dynamic model to study the flight dynamics of micro air vehicles with a reasonably accurate representation of aerodynamic forces and moments. The research is divided into two sections. In the first section, derivation of the nonlinear dynamics of flapping wing micro air vehicles is presented. The flapping wing micro air vehicle (MAV) used in this research is modeled as a system of three rigid bodies: a body and two wings. The design is based on an insect called Drosophila Melanogaster, commonly known as fruit-fly. The mass and inertial effects of the wing on the body are neglected for the present work. The nonlinear dynamics is simulated with the aerodynamic data published in the open literature. The flapping frequency is used as the control input. Simulations are run for different cases of wing positions and the chosen parameters are studied for boundedness. Results show a qualitative inconsistency in boundedness for some cases, and demand a better

  4. The Application of Compulational Fluid Dynamics to Design of Vehicle Cooling Wind Tunnel

    Institute of Scientific and Technical Information of China (English)

    BI Xiao-ping; HUANG Xiao-hui

    2009-01-01

    A computational fluid dynamics (CFD) calculation model for the airflow and heat transfer in an armored vehicle cooling wind tunnel is established. A practical method to determine computation region outside power train compartment, produce grid and ensure grid quality is put forward. A commercial software FLUENT can be used to obtain solutions numerically in 3-D space. Precision of CFD calculation results is verified. The CFD model is used in designing a vehicle cooling wind tunnel, and air flow resistance of fan blast baffle is calculated. The calculated results show feasibility of the CFD model and the method.

  5. Cost-Effectiveness Comparison of Coupler Designs of Wireless Power Transfer for Electric Vehicle Dynamic Charging

    Directory of Open Access Journals (Sweden)

    Weitong Chen

    2016-11-01

    Full Text Available This paper presents a cost-effectiveness comparison of coupler designs for wireless power transfer (WPT, meant for electric vehicle (EV dynamic charging. The design comparison of three common types of couplers is first based on the raw material cost, output power, transfer efficiency, tolerance of horizontal offset, and flux density. Then, the optimal cost-effectiveness combination is selected for EV dynamic charging. The corresponding performances of the proposed charging system are compared and analyzed by both simulation and experimentation. The results verify the validity of the proposed dynamic charging system for EVs.

  6. On the numerical and computational aspects of non-smoothnesses that occur in railway vehicle dynamics

    DEFF Research Database (Denmark)

    True, Hans; Engsig-Karup, Allan Peter; Bigoni, Daniele

    2014-01-01

    The paper contains a report of the experiences with numerical analyses of railway vehicle dynamical systems, which all are nonlinear, non-smooth and stiff high-dimensional systems. Some results are shown, but the emphasis is on the numerical methods of solution and lessons learned. But for two...... examples the dynamical problems are formulated as systems of ordinary differential-algebraic equations due to the geometric constraints. The non-smoothnesses have been neglected, smoothened or entered into the dynamical systems as switching boundaries with relations, which govern the continuation...

  7. Molecular dynamics study on DNA nanotubes as drug delivery vehicle for anticancer drugs.

    Science.gov (United States)

    Liang, Lijun; Shen, Jia-Wei; Wang, Qi

    2017-05-01

    In recent years, self-assembled DNA nanotubes have emerged as a type of nano-biomaterials with great potential for biomedical applications. To develop universal nanocarriers for smart and targeted drug delivery from DNA nanotubes, the understanding of interaction mechanism between DNA nanotubes and drugs is essential. In this study, the interactions between anti-cancer drugs and DNA nanotubes were investigated via molecular dynamics simulation. Our simulation results demonstrated that the DNA nanotubes could serve as a good drug delivery material by absorption of anti-cancer drugs with π-π interactions. At high concentration of anti-cancer drugs, most of the drugs could be absorbed by DNA nanotubes. Therefore, it could greatly decrease the aggregation of anti-cancer drugs in aqueous solution. In addition, the stability of DNA nanotubes could be improved with the absorption of anti-cancer drugs. These findings greatly enhance the understanding of the interaction mechanism of DNA nanotubes and anti-cancer drugs. Our study suggests that DNA nanotubes are promising delivery vehicles by strong absorption of anti-cancer drugs. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Sensitivity analysis of the critical speed in railway vehicle dynamics

    Science.gov (United States)

    Bigoni, D.; True, H.; Engsig-Karup, A. P.

    2014-05-01

    We present an approach to global sensitivity analysis aiming at the reduction of its computational cost without compromising the results. The method is based on sampling methods, cubature rules, high-dimensional model representation and total sensitivity indices. It is applied to a half car with a two-axle Cooperrider bogie, in order to study the sensitivity of the critical speed with respect to the suspension parameters. The importance of a certain suspension component is expressed by the variance in critical speed that is ascribable to it. This proves to be useful in the identification of parameters for which the accuracy of their values is critically important. The approach has a general applicability in many engineering fields and does not require the knowledge of the particular solver of the dynamical system. This analysis can be used as part of the virtual homologation procedure and to help engineers during the design phase of complex systems.

  9. Large-deformation modal coordinates for nonrigid vehicle dynamics

    Science.gov (United States)

    Likins, P. W.; Fleischer, G. E.

    1972-01-01

    The derivation of minimum-dimension sets of discrete-coordinate and hybrid-coordinate equations of motion of a system consisting of an arbitrary number of hinge-connected rigid bodies assembled in tree topology is presented. These equations are useful for the simulation of dynamical systems that can be idealized as tree-like arrangements of substructures, with each substructure consisting of either a rigid body or a collection of elastically interconnected rigid bodies restricted to small relative rotations at each connection. Thus, some of the substructures represent elastic bodies subjected to small strains or local deformations, but possibly large gross deformations, in the hybrid formulation, distributed coordinates referred to herein as large-deformation modal coordinates, are used for the deformations of these substructures. The equations are in a form suitable for incorporation into one or more computer programs to be used as multipurpose tools in the simulation of spacecraft and other complex electromechanical systems.

  10. Flight dynamics modeling of a small ducted fan aerial vehicle based on parameter identification

    Institute of Scientific and Technical Information of China (English)

    Wang Zhengjie; Liu Zhijun; Fan Ningjun; Guo Meifang

    2013-01-01

    This paper presents a simple and useful modeling method to acquire a dynamics model of an aerial vehicle containing unknown parameters using mechanism modeling, and then to design different identification experiments to identify the parameters based on the sources and features of its unknown parameters. Based on the mathematical model of the aerial vehicle acquired by modeling and identification, a design for the structural parameters of the attitude control system is carried out, and the results of the attitude control flaps are verified by simulation experiments and flight tests of the aerial vehicle. Results of the mathematical simulation and flight tests show that the mathematical model acquired using parameter identification is comparatively accurate and of clear mechanics, and can be used as the reference and basis for the structural design.

  11. Probabilistic Sensitivity Analysis for Launch Vehicles with Varying Payloads and Adapters for Structural Dynamics and Loads

    Science.gov (United States)

    McGhee, David S.; Peck, Jeff A.; McDonald, Emmett J.

    2012-01-01

    This paper examines Probabilistic Sensitivity Analysis (PSA) methods and tools in an effort to understand their utility in vehicle loads and dynamic analysis. Specifically, this study addresses how these methods may be used to establish limits on payload mass and cg location and requirements on adaptor stiffnesses while maintaining vehicle loads and frequencies within established bounds. To this end, PSA methods and tools are applied to a realistic, but manageable, integrated launch vehicle analysis where payload and payload adaptor parameters are modeled as random variables. This analysis is used to study both Regional Response PSA (RRPSA) and Global Response PSA (GRPSA) methods, with a primary focus on sampling based techniques. For contrast, some MPP based approaches are also examined.

  12. Propulsion System Dynamic Modeling of the NASA Supersonic Concept Vehicle for AeroPropulsoServoElasticity

    Science.gov (United States)

    Kopasakis, George; Connolly, Joseph W.; Seiel, Jonathan

    2016-01-01

    A summary of the propulsion system modeling under NASA's High Speed Project (HSP) AeroPropulsoServoElasticity (APSE) task is provided with a focus on the propulsion system for the low-boom supersonic configuration developed by Lockheed Martin and referred to as the N+2 configuration. This summary includes details on the effort to date to develop computational models for the various propulsion system components. The objective of this paper is to summarize the model development effort in this task, while providing more detail in the modeling areas that have not been previously published. The purpose of the propulsion system modeling and the overall APSE effort is to develop an integrated dynamic vehicle model to conduct appropriate unsteady analysis of supersonic vehicle performance. This integrated APSE system model concept includes the propulsion system model, and the vehicle structural aerodynamics model. The development to date of such a preliminary integrated model will also be summarized in this report

  13. Analysis of electric vehicle extended range misalignment based on rigid-flexible dynamics

    Science.gov (United States)

    Xu, Xiaowei; Lv, Mingliang; Chen, Zibo; Ji, Wei; Gao, Ruiceng

    2017-04-01

    The safety of the extended range electric vehicle is seriously affected by the misalignment fault. Therefore, this paper analyzed the electric vehicle extended range misalignment based on rigid-flexible dynamics. Through comprehensively applied the hybrid modeling of rigid-flexible and the method of fault diagnosis of machinery and equipment comprehensively, it established a extender hybrid rigid flexible mechanical model by means of the software ADAMS and ANSYS. By setting the relevant parameters to simulate the misalignment of shafting, the failure phenomenon, the spectrum analysis and the evolution rules were analyzed. It concluded that 0.5th and 1 harmonics are considered as the characteristic parameters of misalignment diagnostics for electric vehicle extended range.

  14. Dynamic additional loads influencing the fatigue life of gears in an electric vehicle transmission

    Directory of Open Access Journals (Sweden)

    G.Belingardi

    2014-10-01

    Full Text Available In recent years the implementation of the electric engine in the automotive industries has been increasingly marked. The speed of the electric motors is much higher than the combustion engine ones, bringing transmission gears to be subjected to high dynamic loads. For this reason the dynamic effects on fatigue life of these components have be taken into account in a more careful way respect to what is done with the usual gears. In the present work the overload effects due to both speed and meshing in a gear couple of an electric vehicle transmission have been analyzed. The electric vehicle is designed for urban people mobility and presents all the requirements to be certified as M1 vehicle (a weight less than 600 kg and a maximum speed more than 90 Km/h. To investigate the overload effects of teeth in contact, the reference gear design Standards (ISO 6336 introduce a specific multiplicative factor to the applied load called Internal Dynamic Factor (Kv. Aim of this work is to evaluate how dynamic overloads may influence the fatigue life of the above quoted gears in term of durability. To this goal, Kv values have been calculated by means of the analytical equations (ISO 6336 Methods B and C and then they have been compared with the results coming from multibody simulations, involving full rigid and rigid-flexible models.

  15. Fuzzy chaos control for vehicle lateral dynamics based on active suspension system

    Science.gov (United States)

    Huang, Chen; Chen, Long; Jiang, Haobin; Yuan, Chaochun; Xia, Tian

    2014-07-01

    The existing research of the active suspension system (ASS) mainly focuses on the different evaluation indexes and control strategies. Among the different components, the nonlinear characteristics of practical systems and control are usually not considered for vehicle lateral dynamics. But the vehicle model has some shortages on tyre model with side-slip angle, road adhesion coefficient, vertical load and velocity. In this paper, the nonlinear dynamic model of lateral system is considered and also the adaptive neural network of tire is introduced. By nonlinear analysis methods, such as the bifurcation diagram and Lyapunov exponent, it has shown that the lateral dynamics exhibits complicated motions with the forward speed. Then, a fuzzy control method is applied to the lateral system aiming to convert chaos into periodic motion using the linear-state feedback of an available lateral force with changing tire load. Finally, the rapid control prototyping is built to conduct the real vehicle test. By comparison of time response diagram, phase portraits and Lyapunov exponents at different work conditions, the results on step input and S-shaped road indicate that the slip angle and yaw velocity of lateral dynamics enter into stable domain and the results of test are consistent to the simulation and verified the correctness of simulation. And the Lyapunov exponents of the closed-loop system are becoming from positive to negative. This research proposes a fuzzy control method which has sufficient suppress chaotic motions as an effective active suspension system.

  16. Shape Optimization of Vehicle Radiator Using Computational Fluid Dynamics (cfd)

    Science.gov (United States)

    Maddipatla, Sridhar; Guessous, Laila

    2002-11-01

    Automotive manufacturers need to improve the efficiency and lifetime of all engine components. In the case of radiators, performance depends significantly on coolant flow homogeneity across the tubes and overall pressure drop between the inlet and outlet. Design improvements are especially needed in tube-flow uniformity to prevent premature fouling and failure of heat exchangers. Rather than relying on ad-hoc geometry changes, the current study combines Computational Fluid Dynamics with shape optimization methods to improve radiator performance. The goal is to develop an automated suite of virtual tools to assist in radiator design. Two objective functions are considered: a flow non-uniformity coefficient,Cf, and the overall pressure drop, dP*. The methodology used to automate the CFD and shape optimization procedures is discussed. In the first phase, single and multi-variable optimization methods, coupled with CFD, are applied to simplified 2-D radiator models to investigate effects of inlet and outlet positions on the above functions. The second phase concentrates on CFD simulations of a simplified 3-D radiator model. The results, which show possible improvements in both pressure and flow uniformity, validate the optimization criteria that were developed, as well as the potential of shape optimization methods with CFD to improve heat exchanger design. * Improving Radiator Design Through Shape Optimization, L. Guessous and S. Maddipatla, Paper # IMECE2002-33888, Proceedings of the 2002 ASME International Mechanical Engineering Congress and Exposition, November 2002

  17. An Optimal Energy Management System for Electric Vehicles using Firefly Optimization Algorithm based Dynamic EDF Scheduling

    Directory of Open Access Journals (Sweden)

    E.Kayalvizhi

    2015-08-01

    Full Text Available Mitigation of global warming gases from burning gasoline for transportation in vehicles is one of the biggest and most complex issues the world has ever faced. In an intention to eradicate the environmental crisis caused due to global warming, electric vehicles were been introduced that are powered by electric motor which works on the energy stored in a battery pack. Inspired by the research on power management in electric vehicles, this paper focuses on the development of an energy management system for electric vehicles (EMSEV to optimally balance the energy from battery pack. The proposed methodology uses firefly optimization algorithm to optimize the power consumption of the devices like electric motor, power steering, air conditioner, power window, automatic door locks, radio, speaker, horn, wiper, GPS, internal and external lights etc., from the battery in electric vehicles. Depending upon the distance to cover and the battery availability, the devices are made to switch down automatically through dynamic EDF scheduling. CAN protocol is used for effective communication between the devices and the controller. Simulation results are obtained using MATLAB.

  18. Analyzing the influence of median cross-section design on highway safety using vehicle dynamics simulations.

    Science.gov (United States)

    Stine, Jason S; Hamblin, Bridget C; Brennan, Sean N; Donnell, Eric T

    2010-11-01

    Although vehicle dynamics simulations have long been used in vehicle design and crash reconstruction, their use for highway design is rare. This paper investigates the safety of highway medians through iterative simulations of off-road median encroachments. The commercially available software CarSim was used to simulate over one hundred thousand encroachments, representing the entire passenger vehicle fleet and a wide range of encroachment angles, departure speeds, steering inputs, and braking inputs. Each individual simulation output was then weighted using data from previous studies to reflect the probability of each specific accident scenario occurring in a real-life median encroachment. Results of this analysis illustrate the relative influence of median cross-section geometry on the resulting accident outcomes. The simulations indicate that the overall safety of a highway median depends on the occurrence of both vehicle rollover and median crossover events, and the cross-section shape, slope, and width are all shown to greatly affect each of these incidents. An evaluation of the simulation results was conducted with vehicle trajectories from previous experimental crash tests. Further assessment of the aggregate simulation results to actual crash data was achieved through comparison with several databases of crash statistics. Both efforts showed a strong agreement between the simulations and the real-life crash data.

  19. Global neural dynamic surface tracking control of strict-feedback systems with application to hypersonic flight vehicle.

    Science.gov (United States)

    Xu, Bin; Yang, Chenguang; Pan, Yongping

    2015-10-01

    This paper studies both indirect and direct global neural control of strict-feedback systems in the presence of unknown dynamics, using the dynamic surface control (DSC) technique in a novel manner. A new switching mechanism is designed to combine an adaptive neural controller in the neural approximation domain, together with the robust controller that pulls the transient states back into the neural approximation domain from the outside. In comparison with the conventional control techniques, which could only achieve semiglobally uniformly ultimately bounded stability, the proposed control scheme guarantees all the signals in the closed-loop system are globally uniformly ultimately bounded, such that the conventional constraints on initial conditions of the neural control system can be relaxed. The simulation studies of hypersonic flight vehicle (HFV) are performed to demonstrate the effectiveness of the proposed global neural DSC design.

  20. Impact of aeroelasticity on propulsion and longitudinal flight dynamics of an air-breathing hypersonic vehicle

    Science.gov (United States)

    Raney, David L.; Mcminn, John D.; Pototzky, Anthony S.; Wooley, Christine L.

    1993-01-01

    Many air-breathing hypersonic aerospacecraft design concepts incorporate an elongated fuselage forebody acting as the aerodynamic compression surface for a hypersonic combustion module, or scram jet. This highly integrated design approach creates the potential for an unprecedented form of aero-propulsive-elastic interaction in which deflections of the vehicle fuselage give rise to propulsion transients, producing force and moment variations that may adversely impact the rigid body flight dynamics and/or further excite the fuselage bending modes. To investigate the potential for such interactions, a math model was developed which included the longitudinal flight dynamics, propulsion system, and first seven elastic modes of a hypersonic air-breathing vehicle. Perturbation time histories from a simulation incorporating this math model are presented that quantify the propulsive force and moment variations resulting from aeroelastic vehicle deflections. Root locus plots are presented to illustrate the effect of feeding the propulsive perturbations back into the aeroelastic model. A concluding section summarizes the implications of the observed effects for highly integrated hypersonic air-breathing vehicle concepts.

  1. Contributions of the NASA Langley Transonic Dynamics Tunnel to Launch Vehicle and Spacecraft Development

    Science.gov (United States)

    Cole, Stanley R.; Keller, Donald F.; Piatak, David J.

    2000-01-01

    The NASA Langley Transonic Dynamics Tunnel (TDT) has provided wind-tunnel experimental validation and research data for numerous launch vehicles and spacecraft throughout its forty year history. Most of these tests have dealt with some aspect of aeroelastic or unsteady-response testing, which is the primary purpose of the TDT facility. However, some space-related test programs that have not involved aeroelasticity have used the TDT to take advantage of specific characteristics of the wind-tunnel facility. In general. the heavy gas test medium, variable pressure, relatively high Reynolds number and large size of the TDT test section have made it the preferred facility for these tests. The space-related tests conducted in the TDT have been divided into five categories. These categories are ground wind loads, launch vehicle dynamics, atmospheric flight of space vehicles, atmospheric reentry. and planetary-probe testing. All known TDT tests of launch vehicles and spacecraft are discussed in this report. An attempt has been made to succinctly summarize each wind-tunnel test, or in the case of multiple. related tests, each wind-tunnel program. Most summaries include model program discussion, description of the physical wind-tunnel model, and some typical or significant test results. When available, references are presented to assist the reader in further pursuing information on the tests.

  2. Adaptive and Distributed Algorithms for Vehicle Routing in a Stochastic and Dynamic Environment

    Science.gov (United States)

    2010-11-18

    underlying mathematical model is static and fits within the framework of the Vehicle Routing Problem (see [7] for a thorough introduction to the VRP ...iii) the goal is to compute a set of routes that optimizes the cost of servicing (according to some quality of service metric) the demands. The VRP ...occur- rence in practical problems, the VRP is often a static approx- imation to problems that are in reality dynamic, and therefore it fails to be an

  3. Analysis of the dynamic response in the railway vehicles to the track vertical irregularities. Part II: The numerical analysis

    Directory of Open Access Journals (Sweden)

    M. Dumitriu

    2015-11-01

    Full Text Available The paper examines the dynamic response of a two-bogie vehicle to the symmetrical and antisymmetrical excitations, due to bounce and pitch of the axles’ planes, derived from the track vertical irregularities. Part I introduced the theoretical model and the response functions of the vehicle, as well as the theoretical elements required for the analysis of the dynamic response of the vehicle to the track stochastic irregularities. Part II comprises the results of the numerical analysis of the vehicle dynamic response in three reference points of the carbody, based on which a series of properties of the vertical vibrations behaviour of the railway vehicle is pointed out at. The excitation modes that trigger the carbody response in its reference points are identified. Hence, the influence of the geometrical filtering effect of the excitation modes upon the ride quality and ride comfort is established.

  4. Demonstration Program for Low-Cost, High-Energy-Saving Dynamic Windows

    Science.gov (United States)

    2014-09-01

    Design The scope of this project was to demonstrate the impact of dynamic windows via energy savings and HVAC peak-load reduction; to validate the...dominated by the internal thermal loads of office equipment (example AC 7) so the HVAC energy savings are lower in those zones. Figure 8. Plot...of daily HVAC energy consumption in four representative zones, before and after dynamic windows retrofit. Overall, energy savings in all eastern

  5. Propulsion System Dynamic Modeling for the NASA Supersonic Concept Vehicle: AeroPropulsoServoElasticity

    Science.gov (United States)

    Kopasakis, George; Connolly, Joseph; Seidel, Jonathan

    2014-01-01

    A summary of the propulsion system modeling under NASA's High Speed Project (HSP) AeroPropulsoServoElasticity (APSE) task is provided with a focus on the propulsion system for the low-boom supersonic configuration developed by Lockheed Martin and referred to as the N+2 configuration. This summary includes details on the effort to date to develop computational models for the various propulsion system components. The objective of this paper is to summarize the model development effort in this task, while providing more detail in the modeling areas that have not been previously published. The purpose of the propulsion system modeling and the overall APSE effort is to develop an integrated dynamic vehicle model to conduct appropriate unsteady analysis of supersonic vehicle performance. This integrated APSE system model concept includes the propulsion system model, and the vehicle structural-aerodynamics model. The development to date of such a preliminary integrated model will also be summarized in this report.propulsion system dynamics, the structural dynamics, and aerodynamics.

  6. Dynamic modeling and ascent flight control of Ares-I Crew Launch Vehicle

    Science.gov (United States)

    Du, Wei

    This research focuses on dynamic modeling and ascent flight control of large flexible launch vehicles such as the Ares-I Crew Launch Vehicle (CLV). A complete set of six-degrees-of-freedom dynamic models of the Ares-I, incorporating its propulsion, aerodynamics, guidance and control, and structural flexibility, is developed. NASA's Ares-I reference model and the SAVANT Simulink-based program are utilized to develop a Matlab-based simulation and linearization tool for an independent validation of the performance and stability of the ascent flight control system of large flexible launch vehicles. A linearized state-space model as well as a non-minimum-phase transfer function model (which is typical for flexible vehicles with non-collocated actuators and sensors) are validated for ascent flight control design and analysis. This research also investigates fundamental principles of flight control analysis and design for launch vehicles, in particular the classical "drift-minimum" and "load-minimum" control principles. It is shown that an additional feedback of angle-of-attack can significantly improve overall performance and stability, especially in the presence of unexpected large wind disturbances. For a typical "non-collocated actuator and sensor" control problem for large flexible launch vehicles, non-minimum-phase filtering of "unstably interacting" bending modes is also shown to be effective. The uncertainty model of a flexible launch vehicle is derived. The robust stability of an ascent flight control system design, which directly controls the inertial attitude-error quaternion and also employs the non-minimum-phase filters, is verified by the framework of structured singular value (mu) analysis. Furthermore, nonlinear coupled dynamic simulation results are presented for a reference model of the Ares-I CLV as another validation of the feasibility of the ascent flight control system design. Another important issue for a single main engine launch vehicle is

  7. NPSNET: Real-Time 3D Ground-Based Vehicle Dynamics

    Science.gov (United States)

    1992-03-01

    Meriam et.al., 86]1. Motion is produced by a simplified simulation of dynamics, that describes the linear and angular accelerations of a rigid body in...from the definition of the mass center as covered in statics, is given by 6 mr = Emir, (Eq. 2.1) where the total mass M = Emi [ Meriam et. al., 86]. At...Jurewicz, T., "A Real Time Autonomous Underwater Vehicle Dynamic Simulator," M.S. Thesis, Naval Postgraduate School, Monterey, CA., June 1989 [ Meriam et. al

  8. Dynamic simulation of road vehicle door window regulator mechanism of cross arm type

    Science.gov (United States)

    Miklos, I. Zs; Miklos, C.; Alic, C.

    2017-01-01

    The paper presents issues related to the dynamic simulation of a motor-drive operating mechanism of cross arm type, for the manipulation of road vehicle door windows, using Autodesk Inventor Professional software. The dynamic simulation of the mechanism involves a 3D modelling, kinematic coupling, drive motion parameters and external loads, as well as the graphically view of the kinematic and kinetostatic results for the various elements and kinematic couplings of the mechanism, under real operating conditions. Also, based on the results, the analysis of the mechanism components has been carried out using the finite element method.

  9. Exploration of the Growing Trend of Electric Vehicles in Beijing with System Dynamics method and Vensim model

    NARCIS (Netherlands)

    Zhang, C.; Qin, C.

    2014-01-01

    This research is conducted to explore the growing trend of private vehicles in Beijing, China, in the coming 25 years using the system dynamics (SD) method. The vensim software is used to build the SD model and do simulations. First, the paper introduces the background of the private vehicles in Bei

  10. Express company’s vehicle routing optimization by multiple-dynamic saving algorithm

    Directory of Open Access Journals (Sweden)

    Junchao Liu

    2014-05-01

    Full Text Available Purpose: According to the disorder in circulation commuting and crossover commuting of SF company which is the China’s largest private express delivery service provider, the study uses the Saving Algorithm to make the vehicle routing and resources optimized, on this basis, proposes innovative improvements with Saving Algorithm and then applies it in every distribution center of SF forming a "multi-dynamic" type of Saving Algorithm to ensure both cost savings and timeliness. This method can be generalized for all express company to get the vehicle routing optimized.Design/methodology/approach: As the special transportation requirements of express companies, this study optimizes the vehicle route based on Saving Algorithm, uses multiple-dynamic Saving Algorithm, and considers the timeliness requirements of the express company to achieve a balance of cost and timeliness.Findings: The main finding is that a new method proposed which there can be a balance improvement for both cost and timeliness to optimize the vehicle route of express company. Calculation example validates the effectiveness of the model established and solving method.Practical implications: It is a widespread practice that by setting up model and parameters for the objectives, express company can maintain the balances between cost and timeliness and achieve the optimized vehicle route.Originality/value: It proposes innovative improvements, takes SF express company as an example, with Saving Algorithm which can be applied in every distribution center of express company to ensure the balance improvement for both cost and timeliness, and has a great practical significance to the transportation network and path optimization of express companies.

  11. Research, development, and demonstration of nickel-zinc batteries for electric vehicle propulsion. Annual report for 1980

    Energy Technology Data Exchange (ETDEWEB)

    1981-03-01

    Progress in developing nickel-zinc batteries for propelling electric vehicles is reported. Information is included on component design, battery fabrication, and module performance testing. Although full scale hardware performance has fallen short of the contract cycle life goals, significant progress has been made to warrant further development. (LCL)

  12. The impact of hybrid and electric powertrains on vehicle dynamics, control systems and energy regeneration

    Science.gov (United States)

    Crolla, David A.; Cao, Dongpu

    2012-01-01

    The background to the development of so-called green or low-carbon vehicles continues to be relentlessly reviewed throughout the literature. Research and development (R&D) on novel powertrains - often based on electric or hybrid technology - has been dominating automotive engineering around the world for the first two decades of the twenty-first century. Inevitably, most of the R&D has focused on powertrain technology and energy management challenges. However, as new powertrains have started to become commercially available, their effects on other aspects of vehicle performance have become increasingly important. This article focuses on the review of the integration of new electrified powertrains with the vehicle dynamics and control systems. The integration effects can be discussed in terms of three generic aspects of vehicle motions, namely roll-plane, pitch-plane and yaw-plane, which however are strongly coupled. The topic on regenerative suspension is further discussed. It quickly becomes clear that this integration poses some interesting future engineering challenges to maintain currently accepted levels of ride, handling and stability performance.

  13. Flexible Launch Vehicle Stability Analysis Using Steady and Unsteady Computational Fluid Dynamics

    Science.gov (United States)

    Bartels, Robert E.

    2012-01-01

    Launch vehicles frequently experience a reduced stability margin through the transonic Mach number range. This reduced stability margin can be caused by the aerodynamic undamping one of the lower-frequency flexible or rigid body modes. Analysis of the behavior of a flexible vehicle is routinely performed with quasi-steady aerodynamic line loads derived from steady rigid aerodynamics. However, a quasi-steady aeroelastic stability analysis can be unconservative at the critical Mach numbers, where experiment or unsteady computational aeroelastic analysis show a reduced or even negative aerodynamic damping.Amethod of enhancing the quasi-steady aeroelastic stability analysis of a launch vehicle with unsteady aerodynamics is developed that uses unsteady computational fluid dynamics to compute the response of selected lower-frequency modes. The response is contained in a time history of the vehicle line loads. A proper orthogonal decomposition of the unsteady aerodynamic line-load response is used to reduce the scale of data volume and system identification is used to derive the aerodynamic stiffness, damping, and mass matrices. The results are compared with the damping and frequency computed from unsteady computational aeroelasticity and from a quasi-steady analysis. The results show that incorporating unsteady aerodynamics in this way brings the enhanced quasi-steady aeroelastic stability analysis into close agreement with the unsteady computational aeroelastic results.

  14. Analysis of the Dynamic Response in the Railway Vehicles to the Track Vertical Irregularities. Part I: The Theoretical Model and the Vehicle Response Functions

    Directory of Open Access Journals (Sweden)

    M. Dumitriu

    2015-11-01

    Full Text Available The paper herein focuses on the dynamic response of a two-bogie vehicle to the excitations derived from the track vertical irregularities. The symmetrical and antisymmetrical modes due from the bounce and pitch motions of the axles’ planes in the two bogies are being considered. The analysis of the dynamic response in the vehicle relies on the response functions in three reference points of the carbody, composed by means of these response functions to the symmetrical and antisymmetrical excitation modes. Similarly, the dynamic response of the vehicle to the track stochastic irregularities is examined and expressed as a power spectral density of the carbody vertical acceleration and the root mean square of the acceleration and the index of the partial comfort to the vertical vibrations is calculated. The paper is structured into two parts. The Part I includes all the theoretical elements required for the analysis of the dynamic response in the vehicle, while Part II introduces the results of the numerical analysis.

  15. Incorporating a Wheeled Vehicle Model in a New Monocular Visual Odometry Algorithm for Dynamic Outdoor Environments

    Directory of Open Access Journals (Sweden)

    Yanhua Jiang

    2014-09-01

    Full Text Available This paper presents a monocular visual odometry algorithm that incorporates a wheeled vehicle model for ground vehicles. The main innovation of this algorithm is to use the single-track bicycle model to interpret the relationship between the yaw rate and side slip angle, which are the two most important parameters that describe the motion of a wheeled vehicle. Additionally, the pitch angle is also considered since the planar-motion hypothesis often fails due to the dynamic characteristics of wheel suspensions and tires in real-world environments. Linearization is used to calculate a closed-form solution of the motion parameters that works as a hypothesis generator in a RAndom SAmple Consensus (RANSAC scheme to reduce the complexity in solving equations involving trigonometric. All inliers found are used to refine the winner solution through minimizing the reprojection error. Finally, the algorithm is applied to real-time on-board visual localization applications. Its performance is evaluated by comparing against the state-of-the-art monocular visual odometry methods using both synthetic data and publicly available datasets over several kilometers in dynamic outdoor environments.

  16. Navigation of autonomous vehicles for oil spill cleaning in dynamic and uncertain environments

    Science.gov (United States)

    Jin, Xin; Ray, Asok

    2014-04-01

    In the context of oil spill cleaning by autonomous vehicles in dynamic and uncertain environments, this paper presents a multi-resolution algorithm that seamlessly integrates the concepts of local navigation and global navigation based on the sensory information; the objective here is to enable adaptive decision making and online replanning of vehicle paths. The proposed algorithm provides a complete coverage of the search area for clean-up of the oil spills and does not suffer from the problem of having local minima, which is commonly encountered in potential-field-based methods. The efficacy of the algorithm is tested on a high-fidelity player/stage simulator for oil spill cleaning in a harbour, where the underlying oil weathering process is modelled as 2D random-walk particle tracking. A preliminary version of this paper was presented by X. Jin and A. Ray as 'Coverage Control of Autonomous Vehicles for Oil Spill Cleaning in Dynamic and Uncertain Environments', Proceedings of the American Control Conference, Washington, DC, June 2013, pp. 2600-2605.

  17. Dynamic Gas Flow Effects on the ESD of Aerospace Vehicle Surfaces

    Science.gov (United States)

    Hogue, Michael D.; Kapat, Jayanta; Ahmed, Kareem; Cox, Rachel E.; Wilson, Jennifer G.; Calle, Luz M.; Mulligan, Jaysen

    2016-01-01

    The purpose of this work is to develop a dynamic version of Paschen's Law that takes into account the flow of ambient gas past aerospace vehicle surfaces. However, the classic Paschen's Law does not take into account the flow of gas of an aerospace vehicle, whose surfaces may be triboelectrically charged by dust or ice crystal impingement, traversing the atmosphere. The basic hypothesis of this work is that the number of electron-ion pairs created per unit distance by the electric field between the electrodes is mitigated by the electron-ion pairs removed per unit distance by the flow of gas. The revised Paschen equation must be a function of the mean velocity, v(sub xm), of the ambient gas and reduces to the classical version of Paschen's law when the gas mean velocity, v(sub xm) = 0. New formulations of Paschen's Law, taking into account Mach number and dynamic pressure, derived by the authors, will be discussed. These equations will be evaluated by wind tunnel experimentation later this year. Based on the results of this work, it is hoped that the safety of aerospace vehicles will be enhanced with a redefinition of electrostatic launch commit criteria. It is also possible that new products, such as new anti-static coatings, may be formulated from this data.

  18. Development of a Vehicle-Bridge-Soil Dynamic Interaction Model for Scour Damage Modelling

    Directory of Open Access Journals (Sweden)

    L. J. Prendergast

    2016-01-01

    Full Text Available Damage detection in bridges using vibration-based methods is an area of growing research interest. Improved assessment methodologies combined with state-of-the-art sensor technology are rapidly making these approaches applicable for real-world structures. Applying these techniques to the detection and monitoring of scour around bridge foundations has remained challenging; however this area has gained attraction in recent years. Several authors have investigated a range of methods but there is still significant work required to achieve a rounded and widely applicable methodology to detect and monitor scour. This paper presents a novel Vehicle-Bridge-Soil Dynamic Interaction (VBSDI model which can be used to simulate the effect of scour on an integral bridge. The model outputs dynamic signals which can be analysed to determine modal parameters and the variation of these parameters with respect to scour can be examined. The key novelty of this model is that it is the first numerical model for simulating scour that combines a realistic vehicle loading model with a robust foundation soil response model. This paper provides a description of the model development and explains the mathematical theory underlying the model. Finally a case study application of the model using typical bridge, soil, and vehicle properties is provided.

  19. AQUILA Remotely Piloted Vehicle System Technology Demonstrator (RPV-STD) Program. Volume I. System Description and Capabilities

    Science.gov (United States)

    1979-04-01

    is selectively distributed by an RPV ground control box specially designed by LMSC for the Aquila system. Both units and the RPV umbilical power cord ...View. . 0 . ... 0 . . .. . .... . 282 137 Schematic Drawing of Dryer .................... o 284 138 Remote Umbilical Removal ........ ....... ... .. 268...support on the assembly stand. The vehicle is clamped to the stand at the wing stub trailing edge and by the lnching skeg to prevent slippage and

  20. Prediction of dynamics of bellows in exhaust system of vehicle using equivalent beam modeling

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Jin Ho; Kim, Yong Dae; Lee, Nam Young; Lee, Sang Woo [Noise and vibration CAE Team, Hyundai Motor Company, Ulsan (Korea, Republic of)

    2015-11-15

    The exhaust system is one of the major sources of vibrations, along with the suspension system and engine. When the exhaust system is connected directly to the engine, it transfers vibrations to the vehicle body through the body mounts. Therefore, in order to reduce the vibrations transmitted from the exhaust system, the vibration characteristics of the exhaust system should be predicted. Thus, the dynamic characteristics of the bellows, which form a key component of the exhaust system, must be modeled accurately. However, it is difficult to model the bellows because of the complicated geometry. Though the equivalent beam modeling technique has been applied in the design stage, it is not sufficiently accurate in the case of the bellows which have complicated geometries. In this paper, we present an improved technique for modeling the bellows in a vehicle. The accuracy of the modeling method is verified by comparison with the experimental results.

  1. Autonomous Coil Alignment System Using Fuzzy Steering Control for Electric Vehicles with Dynamic Wireless Charging

    Directory of Open Access Journals (Sweden)

    Karam Hwang

    2015-01-01

    Full Text Available An autonomous coil alignment system (ACAS using fuzzy steering control is proposed for vehicles with dynamic wireless charging. The misalignment between the power receiver coil and power transmitter coil is determined based on the voltage difference between two coils installed on the front-left/front-right of the power receiver coil and is corrected through autonomous steering using fuzzy control. The fuzzy control is chosen over other control methods for implementation in ACAS due to the nonlinear characteristic between voltage difference and lateral misalignment distance, as well as the imprecise and constantly varying voltage readings from sensors. The operational validity and feasibility of the ACAS are verified through simulation, where the vehicle equipped with ACAS is able to align with the power transmitter in the road majority of the time during operation, which also implies achieving better wireless power delivery.

  2. A Flight Dynamics Model for a Multi-Actuated Flexible Rocket Vehicle

    Science.gov (United States)

    Orr, Jeb S.

    2011-01-01

    A comprehensive set of motion equations for a multi-actuated flight vehicle is presented. The dynamics are derived from a vector approach that generalizes the classical linear perturbation equations for flexible launch vehicles into a coupled three-dimensional model. The effects of nozzle and aerosurface inertial coupling, sloshing propellant, and elasticity are incorporated without restrictions on the position, orientation, or number of model elements. The present formulation is well suited to matrix implementation for large-scale linear stability and sensitivity analysis and is also shown to be extensible to nonlinear time-domain simulation through the application of a special form of Lagrange s equations in quasi-coordinates. The model is validated through frequency-domain response comparison with a high-fidelity planar implementation.

  3. Nonlinear Dynamic Modeling of a Fixed-Wing Unmanned Aerial Vehicle: a Case Study of Wulung

    Directory of Open Access Journals (Sweden)

    Fadjar Rahino Triputra

    2015-07-01

    Full Text Available Developing a nonlinear adaptive control system for a fixed-wing unmanned aerial vehicle (UAV requires a mathematical representation of the system dynamics analytically as a set of differential equations in the form of a strict-feedback systems. This paper presents a method for modeling a nonlinear flight dynamics of the fixed-wing UAV of BPPT Wulung in any conditions of the flight altitude and airspeed for the first step into designing a nonlinear adaptive controller. The model was formed into 10-DOF differential equations in the form of strict-feedback systems which separates the terms of elevator, aileron, rudder and throttle from the model. The model simulation results show the behavior of the flight dynamics of the Wulung UAV and also prove the compliance with the actual flight test results.

  4. Static and dynamic stability analysis of the space shuttle vehicle-orbiter

    Science.gov (United States)

    Chyu, W. J.; Cavin, R. K.; Erickson, L. L.

    1978-01-01

    The longitudinal static and dynamic stability of a Space Shuttle Vehicle-Orbiter (SSV Orbiter) model is analyzed using the FLEXSTAB computer program. Nonlinear effects are accounted for by application of a correction technique in the FLEXSTAB system; the technique incorporates experimental force and pressure data into the linear aerodynamic theory. A flexible Orbiter model is treated in the static stability analysis for the flight conditions of Mach number 0.9 for rectilinear flight (1 g) and for a pull-up maneuver (2.5 g) at an altitude of 15.24 km. Static stability parameters and structural deformations of the Orbiter are calculated at trim conditions for the dynamic stability analysis, and the characteristics of damping in pitch are investigated for a Mach number range of 0.3 to 1.2. The calculated results for both the static and dynamic stabilities are compared with the available experimental data.

  5. Dynamic Modeling and Simulation on a Hybrid Power System for Electric Vehicle Applications

    Directory of Open Access Journals (Sweden)

    Hong-Wen He

    2010-11-01

    Full Text Available Hybrid power systems, formed by combining high-energy-density batteries and high-power-density ultracapacitors in appropriate ways, provide high-performance and high-efficiency power systems for electric vehicle applications. This paper first establishes dynamic models for the ultracapacitor, the battery and a passive hybrid power system, and then based on the dynamic models a comparative simulation between a battery only power system and the proposed hybrid power system was done under the UDDS (Urban Dynamometer Driving Schedule. The simulation results showed that the hybrid power system could greatly optimize and improve the efficiency of the batteries and their dynamic current was also decreased due to the participation of the ultracapacitors, which would have a good influence on batteries’ cycle life. Finally, the parameter matching for the passive hybrid power system was studied by simulation and comparisons.

  6. Sliding Mode Control for Mass Moment Aerospace Vehicles Using Dynamic Inversion Approach

    Directory of Open Access Journals (Sweden)

    Xiao-Yu Zhang

    2013-01-01

    Full Text Available The moving mass actuation technique offers significant advantages over conventional aerodynamic control surfaces and reaction control systems, because the actuators are contained entirely within the airframe geometrical envelope. Modeling, control, and simulation of Mass Moment Aerospace Vehicles (MMAV utilizing moving mass actuators are discussed. Dynamics of the MMAV are separated into two parts on the basis of the two time-scale separation theory: the dynamics of fast state and the dynamics of slow state. And then, in order to restrain the system chattering and keep the track performance of the system by considering aerodynamic parameter perturbation, the flight control system is designed for the two subsystems, respectively, utilizing fuzzy sliding mode control approach. The simulation results describe the effectiveness of the proposed autopilot design approach. Meanwhile, the chattering phenomenon that frequently appears in the conventional variable structure systems is also eliminated without deteriorating the system robustness.

  7. Initial results from the Solar Dynamic (SD) Ground Test Demonstration (GTD) project at NASA Lewis

    Science.gov (United States)

    Shaltens, Richard K.; Boyle, Robert V.

    1995-01-01

    A government/industry team designed, built, and tested a 2 kWe solar dynamic space power system in a large thermal/vacuum facility with a simulated sun at the NASA Lewis Research Center. The Lewis facility provides an accurate simulation of temperatures, high vacuum, and solar flux as encountered in low earth orbit. This paper reviews the goals and status of the Solar Dynamic (SD) Ground Test Demonstration (GTD) program and describes the initial testing, including both operational and performance data. This SD technology has the potential as a future power source for the International Space Station Alpha.

  8. A Mathematical Model and Simulation Results of the Dynamic System Railway Vehicle Wheel–Track with a Wheel Flat

    Directory of Open Access Journals (Sweden)

    Rasa Žygienė

    2014-12-01

    Full Text Available A mathematical model of the system Railway Vehicle Wheel–Track with a wheel flat of a wheelset has been made. The system Railway Vehicle Wheel–Track has been examined on the vertical plane. The mathematical model of the system Railway Vehicle Wheel–Track has employed linear, nonlinear, elastic and damping discrete elements. Rail dynamics haves been described using the finite element method. The unevenness of the rail and the wheel of the wheelset have been evaluated considering the contact between the rail and the wheel flat of the wheelset. The analysis of dynamic processes taking place in a railway vehicle wheel with the wheel flat moving at speed V = 60 km/h has been accomplished. The results of mathematical modelling of the above introduced dynamic system have been presented along with graphically displayed research findings of the conducted research.

  9. Experimental demonstration of a dynamic bowtie for region-based CT fluence optimization

    Science.gov (United States)

    Robinson, Vance; Smith, Walt; Rui, Xue; Yin, Zhye; Wu, Mingye; Fitzgerald, Paul; De Man, Bruno

    2016-03-01

    Technology development in Computed Tomography (CT) is driven by clinical needs, for example the need for image quality sufficient for the clinical task, and the need to obtain the required image quality using the lowest possible radiation dose to the patient. One approach to manage dose without compromising image quality is to spatially vary the X-ray flux such that regions of high interest receive more radiation while regions of low interest or regions sensitive to radiation receive less dose. If the region of interest (ROI) is centered at the CT system's axis of rotation, a simple stationary bowtie mounted between the X-ray tube and the patient is sufficient to reduce the X-ray flux outside the central region. If the ROI is off center, then a dynamic bowtie that can track the ROI as the gantry rotates is preferred. We experimentally demonstrated the dynamic bowtie using a design that is relatively simple, low cost, requires no auxiliary power supply, and can be retrofitted to an existing clinical CT scanner. We installed our prototype dynamic bowtie on a clinical CT scanner, and we scanned a phantom with a pre-selected off-center ROI. The dynamic bowtie reduced the X-ray intensity outside the targeted ROI tenfold. As a result, the reconstructed image shows significantly lower noise within the dynamic bowtie ROI compared to regions outside it. Our preliminary results suggest that a dynamic bowtie could be an effective solution for further reducing CT radiation dose.

  10. DEVELOPMENT OF A SIMULATION TOOL FOR THE DYNAMIC ANALYSIS OF RAILWAY VEHICLE - TRACK INTERACTION

    Directory of Open Access Journals (Sweden)

    Ramy SHALTOUT

    2015-12-01

    Full Text Available The importance of modelling and simulation in the field of railway systems has greatly increased in the last decades. Various commercial simulation packages have been developed and are used to analyse the dynamic performance of railway systems. However, although sometimes the user needs to analyse various non-standard solutions, the possibility to integrate further modifications into the structure of such software is quite limited. Therefore, in some cases, in particular for specific modelling and analysis tasks, a feasible option is to develop flexible and robust simulation tools capable of using different configurations by modifying the models performing the dynamic analysis. The paper presents the mathematical modelling background and the conceptual design of a new of a new computational tool for the dynamic simulation of railway vehicle systems. The formulations employed in the proposed mathematical model are based on the multibody techniques. The developed model uses a combined frame of references that allows the use of independent coordinates without the possibility to have singularity configurations depending on the rotation sequence. The simulation tool is designed in a flexible form that enables the study of different configurations of the railway vehicles, as well as various track combinations.

  11. Dynamics of vehicle-pavement coupled system based on a revised flexible roller contact tire model

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    A revised flexible roller contact tire model (RFRC tire model) is proposed, which considers not only the geometric and flexible filtering effect, but also tire damping and pavement displacement. A vehi- cle-pavement coupled system is modeled as a two DOF oscillator moving along a simply supported beam on a linear viscoelastic foundation. By using the Galerkin’s and Direct Integral method, dynamical responses of the vehicle-pavement coupled system are obtained based on the RFRC tire model and the traditional single point contact tire model (SPC tire model). The simulation results are compared with test data and the validity of the proposed RFRC tire model is verified. Differences between the two models are also investigated. It is found that the dynamical behaviors for both models agree with each other quite well when road surface roughness is a long harmonic wave. On the other hand, they are different under short harmonic wave or impulse road excitation. Thus the RFRC tire model should be used to compute the tire force and investigate dynamical responses of vehicle and pavement.

  12. Dynamics of vehicle-pavement coupled system based on a revised flexible roller contact tire model

    Institute of Scientific and Technical Information of China (English)

    YANG ShaoPu; LI ShaoHua; LU YongJie

    2009-01-01

    A revised flexible roller contact tire model (RFRC tire model) is proposed, which considers not only the geometric and flexible filtering effect, but also tire damping and pavement displacement. A vehi-cle-pavement coupled system is modeled as a two DOF oscillator moving along a simply supported beam on a linear viscoelastic foundation. By using the Galerkin's and Direct Integral method, dynamical responses of the vehicle-pavement coupled system are obtained based on the RFRC tire model and the traditional single point contact tire model (SPC tire model). The simulation results are compared with test data and the validity of the proposed RFRC tire model is verified. Differences between the two models are also investigated. It is found that the dynamical behaviors for both models agree with each other quite well when road surface roughness is a long harmonic wave. On the other hand, they are different under short harmonic wave or impulse road excitation. Thus the RFRC tire model should be used to compute the tire force and investigate dynamical responses of vehicle and pavement.

  13. Dynamic and Static High Temperature Resistant Ceramic Seals for X- 38 re-Entry Vehicle

    Science.gov (United States)

    Handrick, Karin E.; Curry, Donald M.

    2002-01-01

    In a highly successful partnership, NAS A, ESA, DLR (German Space Agency) and European industry are building the X-38, V201 re-entry spacecraft, the prototype of the International Space Station's Crew Return Vehicle (CRV). This vehicle would serve both as an ambulance for medical emergencies and as an evacuation vehicle for the Space Station. The development of essential systems and technologies for a reusable re-entry vehicle is a first for Europe, and sharing the development of an advanced re-entry spacecraft with foreign partners is a first for NASA. NASA, in addition to its subsystem responsibilities, is performing overall X-38 vehicle system engineering and integration, will launch V201 on the Space Shuttle, deliver flight data for post-flight analysis and assessment and is responsible for development and manufacture of structural vehicle components and thermal protection (TPS) tiles. The major European objective for cooperation with NASA on X-38 was to establish a clear path through which key technologies needed for future space transportation systems could be developed and validated at affordable cost and with controlled risk. Europe has taken the responsibility to design and manufacture hot control surfaces like metallic rudders and ceramic matrix composites (CMC) body flaps, thermal protection systems such as CMC leading edges, the CMC nose cap and -skirt, insulation, landing gears and elements of the V201 primary structure. Especially hot control surfaces require extremely high temperature resistant seals to limit hot gas ingestion and transfer of heat to underlying low-temperature structures to prevent overheating of these structures and possible loss of the vehicle. Complex seal interfaces, which have to fulfill various, tight mission- and vehicle-related requirements exist between the moveable ceramic body flaps and the bottom surface of the vehicle, between the rudder and fin structure and the ceramic leading edge panel and TPS tiles. While NASA

  14. NASA solar dynamic ground test demonstration (GTD) program and its application to space nuclear power

    Science.gov (United States)

    Harper, William B.; Shaltens, Richard K.

    1993-01-01

    Closed Brayton cycle power conversion systems are readily adaptable to any heat source contemplated for space application. The inert gas working fluid can be used directly in gas-cooled reactors and coupled to a variety of heat sources (reactor, isotope or solar) by a heat exchanger. This point is demonstrated by the incorporation in the NASA 2 kWe Solar Dynamic (SD) Space Power Ground Test Demonstration (GTD) Program of the turboalternator-compressor and recuperator from the Brayton Isotope Power System (BIPS) program. This paper will review the goals and status of the SD GTD Program, initiated in April 1992. The performance of the BIPS isotope-heated system will be compared to the solar-heated GTD system incorporating the BIPS components and the applicability of the GTD test bed to dynamics space nuclear power R&D will be discussed.

  15. The simulation of occasional road disturbances for studying mobile vehicles dynamics

    Directory of Open Access Journals (Sweden)

    T.A. Alexeeva

    2015-06-01

    Full Text Available This paper presents a procedure for simulating random road disturbances based on the method of non-canonically decomposing random functions in the form of deterministic functions depending on just three random quantities under any probability distribution law. The mathematical methods developed for modeling random road disturbances give an accurate representation of the random function perturbations in the framework of the correlation theory using just three random variables. The proposed approach allows to obtain more reliable data on the spectral composition of the microrelief, to simplify the study of the dynamics of mobile vehicles and reduce the amount of computation in comparison with other methods.

  16. Theoretical and Numerical Studies of Dynamic Scaling of a Six-Degree-of-Freedom Laser Propulsion Vehicle

    Directory of Open Access Journals (Sweden)

    Masayuki Takahashi

    2015-01-01

    Full Text Available To estimate the flight reactions of a full-scale vehicle from reduced-scale tests, we constructed a scaling theory for the vehicle size, input energy, moment of inertia, and pulse frequency needed to maintain dynamic equivalence between a laboratory-scale and full-scale launch of a laser propulsion vehicle. The dynamic scaling law for a single pulse was constructed using translational and angular equations of motion. The analytical scaling was confirmed for a single-pulse incident using a fluid-orbit coupling simulator for the interaction between the blast wave and the vehicle. Motion equivalence was maintained for multiple pulses by adjusting the repetition frequency of the pulse incident to correct for the effect of aerodynamic drag during the free flight of the pulse-to-pulse interval. The flight of a full-scale vehicle can be estimated for single- and multiple-pulse operations from the flight data for a small-scale vehicle using the proposed scaling theory, which provides correlations between the characteristics of small-scale and large-scale flight systems. Small-scale tests were shown to be useful in estimating the flight of a full-scale vehicle using dynamic scaling theory.

  17. Update of the 2 Kw Solar Dynamic Ground Test Demonstration Program

    Science.gov (United States)

    Shaltens, Richard K.; Boyle, Robert V.

    1994-01-01

    The Solar Dynamic (SD) Ground Test Demonstration (GTD) program demonstrates the operation of a complete 2 kW, SD system in a simulated space environment at a NASA Lewis Research Center (LeRC) thermal-vacuum facility. This paper reviews the goals and status of the SD GTD program. A brief description of the SD system identifying key design features of the system, subsystems, and components is included. An aerospace industry/government team is working together to design, fabricate, assemble, and test a complete SD system.

  18. Research, development, and demonstration of lead-acid batteries for electric vehicle propulsion. Annual report for 1980

    Energy Technology Data Exchange (ETDEWEB)

    1981-03-01

    Work performed during Oct. 1, 1979 to Sept. 30, 1980 for the development of lead-acid batteries for electric vehicle propulsion is described. During this report period many of the results frpm Globe Battery's design, materials and process development programs became evident in the achievement of the ISOA (Improved State of Art) specific energy, specific power, and energy efficiency goals while testing in progress also indicates that the cycle life goal can be met. These programs led to the establishment of a working pilot assembly line which produced the first twelve volt ISOA modules. Five of these modules were delivered to the National Battery Test Laboratory during the year for capacity, power and life testing, and assembly is in progress of three full battery systems for installation in vehicles. In the battery subsystem area, design of the acid circulation system for a ninety-six volt ISOA battery pack was completed and assembly of the first such system was initiated. Charger development has been slowed by problems encountered with reliability of some circuits but a prototype unit is being prepared which will meet the charging requirements of our ninety-six volt pack. This charger will be available during the 1981 fiscal year.

  19. Design and Construction of an Affordable Rotating Table for Classroom Demonstrations of Geophysical Fluid Dynamics Principles.

    Science.gov (United States)

    McNoldy, Brian D.; Cheng, Anning; Eitzen, Zachary A.; Moore, Richard W.; Persing, John; Schaefer, Kevin; Schubert, Wayne H.

    2003-12-01

    Rotating tables have been in use for many years because of their ability to demonstrate fluid dynamical phenomena, shedding insight on the sometimes complicated or esoteric mathematics used to describe such processes. A small team of students at the Colorado State University (CSU) Department of Atmospheric Science constructed a rotating table, or “spin tank,” assembly that is simple and affordable, yet instructive.The apparatus is designed to be easy to maintain and operate. The number of moving parts is kept at a minimum, and the electrical components chosen are of high quality. With the aid of a brief instruction manual or tutorial, students and faculty can operate the rotating table and easily perform many demonstrations, with the freedom to vary fluid depth, rotation rate, and acceleration. The entire design and construction process was conducted on a limited budget of &;3,000.A spin tank such as this has practical applications for the qualitative study of fluid dynamics. Fundamental concepts in rotating flow dynamics can be demonstrated to supplement the more rigorous mathematical treatment typically given in oceanography or atmospheric physics graduate-level courses. Topics that have been explored thus far are Ekman pumping, Taylor columns, and barotropic instability, but could be broadened to include subjects such as Rossby waves, baroclinic instability, vortex merger, and thermal convection.

  20. Demonstrating universal scaling for dynamics of Yukawa one-component plasmas after an interaction quench

    Science.gov (United States)

    Langin, T. K.; Strickler, T.; Maksimovic, N.; McQuillen, P.; Pohl, T.; Vrinceanu, D.; Killian, T. C.

    2016-02-01

    The Yukawa one-component plasma (OCP) model is a paradigm for describing plasmas that contain one component of interest and one or more other components that can be treated as a neutralizing, screening background. In appropriately scaled units, interactions are characterized entirely by a screening parameter, κ . As a result, systems of similar κ show the same dynamics, regardless of the underlying parameters (e.g., density and temperature). We demonstrate this behavior using ultracold neutral plasmas (UNPs) created by photoionizing a cold (T ≤10 mK) gas. The ions in UNP systems are well described by the Yukawa model, with the electrons providing the screening. Creation of the plasma through photoionization can be thought of as a rapid quench of the interaction potential from κ =∞ to a final κ value set by the electron density and temperature. We demonstrate experimentally that the postquench dynamics are universal in κ over a factor of 30 in density and an order of magnitude in temperature. Results are compared with molecular-dynamics simulations. We also demonstrate that features of the postquench kinetic energy evolution, such as disorder-induced heating and kinetic-energy oscillations, can be used to determine the plasma density and the electron temperature.

  1. Dynamic Performance on Multi Storey Structure Due to Ground Borne Vibrations Input from Passing Vehicles

    Directory of Open Access Journals (Sweden)

    Tuan Norhayati Tuan Chik

    2013-12-01

    Full Text Available Ground borne vibration from passing vehicles could excite the adjacent ground, hence produces a vibration waves that will propagate through layers of soil towards the foundations of any adjacent building. This vibration could affects the structure of the building at some levels and even the low sensitivity equipment are also could be affected as well. The objectives of this study are to perform the structural response on multi storey building subjected to ground vibrations input and to determine the level of vibration at each floor from road traffic on the observed building. The scopes of the study are focused on the groundborne vibrations induced by the passing vehicles and analyse the data by using dynamic software such as ANSYSv14 and MATLAB. The selected building for this study is the Registrar Office building which is located in Universiti Tun Hussein Onn Malaysia (UTHM. The inputs of the vibration were measured by using Laser Doppler Vibrometer (LDV equipment. By conducting the field measurement, a real input of ground borne vibration from the loads of vehicle towards any adjacent building can be obtained. Finally, the vibration level from road traffic on office building can be determined using overseas generic criteria guidelines. The vibration level achieved for this building is at above the ISO level, which is suitable for office building and within acceptable limit.

  2. Multiobjective Dynamic Vehicle Routing Problem and Time Seed Based Solution Using Particle Swarm Optimization

    Directory of Open Access Journals (Sweden)

    Omprakash Kaiwartya

    2015-01-01

    Full Text Available A multiobjective dynamic vehicle routing problem (M-DVRP has been identified and a time seed based solution using particle swarm optimization (TS-PSO for M-DVRP has been proposed. M-DVRP considers five objectives, namely, geographical ranking of the request, customer ranking, service time, expected reachability time, and satisfaction level of the customers. The multiobjective function of M-DVRP has four components, namely, number of vehicles, expected reachability time, and profit and satisfaction level. Three constraints of the objective function are vehicle, capacity, and reachability. In TS-PSO, first of all, the problem is partitioned into smaller size DVRPs. Secondly, the time horizon of each smaller size DVRP is divided into time seeds and the problem is solved in each time seed using particle swarm optimization. The proposed solution has been simulated in ns-2 considering real road network of New Delhi, India, and results are compared with those obtained from genetic algorithm (GA simulations. The comparison confirms that TS-PSO optimizes the multiobjective function of the identified problem better than what is offered by GA solution.

  3. Modeling of dynamic vehicle-road interactions for safety-related road evaluation.

    Science.gov (United States)

    Orfila, O; Coiret, A; Do, M T; Mammar, S

    2010-11-01

    Usually, road safety is assessed by following adequate highway geometric design standards and can be controlled later by measurement and expertise. Nevertheless, interactions between vehicle dynamics and road characteristics cannot be simultaneously analyzed for these two means of safety evaluation. In this study, an analytical method based on road/vehicle physical interactions applied to road diagnosis is proposed. Vehicle "point" and "bicycle" models are used in this first approach. French highway geometric design standards and a statistical method are presented and evaluated on a real curve case. The proposed numerical criterion, for the "bicycle" model, is then compared to these two classical methods for the considered road section. Its advantages are that it takes into account several combined parameters, that road defects are precisely localized and that it provides hierarchically classified solutions to the road managers. After this comparison step, further improvements should be focused on the modeling of successive curves and on the improvement of the informations given to the road manager.

  4. Performance Improvement of Inertial Navigation System by Using Magnetometer with Vehicle Dynamic Constraints

    Directory of Open Access Journals (Sweden)

    Daehee Won

    2015-01-01

    Full Text Available A navigation algorithm is proposed to increase the inertial navigation performance of a ground vehicle using magnetic measurements and dynamic constraints. The navigation solutions are estimated based on inertial measurements such as acceleration and angular velocity measurements. To improve the inertial navigation performance, a three-axis magnetometer is used to provide the heading angle, and nonholonomic constraints (NHCs are introduced to increase the correlation between the velocity and the attitude equation. The NHCs provide a velocity feedback to the attitude, which makes the navigation solution more robust. Additionally, an acceleration-based roll and pitch estimation is applied to decrease the drift when the acceleration is within certain boundaries. The magnetometer and NHCs are combined with an extended Kalman filter. An experimental test was conducted to verify the proposed method, and a comprehensive analysis of the performance in terms of the position, velocity, and attitude showed that the navigation performance could be improved by using the magnetometer and NHCs. Moreover, the proposed method could improve the estimation performance for the position, velocity, and attitude without any additional hardware except an inertial sensor and magnetometer. Therefore, this method would be effective for ground vehicles, indoor navigation, mobile robots, vehicle navigation in urban canyons, or navigation in any global navigation satellite system-denied environment.

  5. Consideration of nonlinear wheel-rail contact forces for dynamic vehicle-bridge interaction in high-speed railways

    Science.gov (United States)

    Antolín, Pablo; Zhang, Nan; Goicolea, José M.; Xia, He; Astiz, Miguel Á.; Oliva, Javier

    2013-03-01

    In this work models with nonlinear wheel-rail contact forces are considered for analysing the dynamic interaction between high speed trains and bridges, in order to study dynamic effects both in the bridge and in the vehicles resulting from the coupling. Nonlinear contact models may be necessary for evaluating the stability and the safety of running traffic in situations such as vehicle overturn when the train is crossing a bridge under strong lateral winds or when an earthquake occurs. For studying the coupled dynamic response of trains and bridges, models of multibody dynamics are used for vehicles and the finite element method for structures. Special relevance is given here to the consideration of contact interaction forces between railway vehicles and the track. Four different interaction models are compared in this work: (1) a model where the vehicle wheelset is considered to be rigidly coupled to the track; (2) a staggered uncoupled method in which vehicle and structure are analysed separately; (3) a linear contact model in which lateral relative displacements between rails and train wheels are allowed, assuming biconic wheel and rail profiles and linear Kalker theory for tangential contact; (4) a nonlinear model in which realistic wheel and rail profiles, Hertz's nonlinear theory for normal contact and Kalker's nonlinear theory for tangential contact are used. The different models are applied and compared to experimental measurements for a test case of a high-speed train in China.

  6. A Comprehensive Structural Dynamic Analysis Approach for Multi Mission Earth Entry Vehicle (MMEEV) Development

    Science.gov (United States)

    Perino, Scott; Bayandor, Javid; Siddens, Aaron

    2012-01-01

    The anticipated NASA Mars Sample Return Mission (MSR) requires a simple and reliable method in which to return collected Martian samples back to earth for scientific analysis. The Multi-Mission Earth Entry Vehicle (MMEEV) is NASA's proposed solution to this MSR requirement. Key aspects of the MMEEV are its reliable and passive operation, energy absorbing foam-composite structure, and modular impact sphere (IS) design. To aid in the development of an EEV design that can be modified for various missions requirements, two fully parametric finite element models were developed. The first model was developed in an explicit finite element code and was designed to evaluate the impact response of the vehicle and payload during the final stage of the vehicle's return to earth. The second model was developed in an explicit code and was designed to evaluate the static and dynamic structural response of the vehicle during launch and reentry. In contrast to most other FE models, built through a Graphical User Interface (GUI) pre-processor, the current model was developed using a coding technique that allows the analyst to quickly change nearly all aspects of the model including: geometric dimensions, material properties, load and boundary conditions, mesh properties, and analysis controls. Using the developed design tool, a full range of proposed designs can quickly be analyzed numerically and thus the design trade space for the EEV can be fully understood. An engineer can then quickly reach the best design for a specific mission and also adapt and optimize the general design for different missions.

  7. Research, development, and demonstration of lead-acid batteries for electric-vehicle propulsion. Annual report, 1980

    Energy Technology Data Exchange (ETDEWEB)

    1981-03-01

    The first development effort in improving lead-acid batteries fore electric vehicles was the improvement of electric vehicle batteries using flat pasted positive plates and the second was for a tubular long life positive plate. The investigation of 32 component variables based on a flat pasted positive plate configuration is described. The experiment tested 96 - six volt batteries for characterization at 0, 25, and 40/sup 0/C and for cycle life capability at the 3 hour discharge rate with a one cycle, to 80% DOD, per day regime. Four positive paste formulations were selected. Two commercially available microporous separators were used in conjunction with a layer of 0.076 mm thick glass mat. Two concentrations of battery grade sulfuric acid were included in the test to determine if an increase in concentration would improve the battery capacity sufficient to offset the added weight of the more concentrated solution. Two construction variations, 23 plate elements with outside negative plates and 23 plate elements with outside positive plates, were included. The second development effort was an experiment designed to study the relationship of 32 component variables based on a tubular positive plate configuration. 96-six volt batteries were tested at various discharge rates at 0, 25, and 40/sup 0/C along with cycle life testing at 80% DOD of the 3 hour rate. 75 batteries remain on cycle life testing with 17 batteries having in excess of 365 life cycles. Preliminary conclusions indicate: the tubular positive plate is far more capable of withstanding deep cycles than is the flat pasted plate; as presently designed 40 Whr/kg can not be achieved, since 37.7 Whr/kg was the best tubular data obtained; electrolyte circulation is impaired due to the tight element fit in the container; and a redesign is required to reduce the battery weight which will improve the Whr/kg value. This redesign is complete and new molds have been ordered.

  8. Impact of the variation in dynamic vehicle load on flexible pavement responses

    Science.gov (United States)

    Ahsanuzzaman, Md

    The purpose of this research was to evaluate the dynamic variation in asphalt pavement critical responses due to dynamic tire load variations. An attempt was also made to develop generalized regression equations to predict the dynamic response variation in flexible pavement under various dynamic load conditions. The study used an extensive database of computed pavement response histories for five different types of sites (smooth, rough, medium rough, very rough and severely rough), two different asphalt pavement structures (thin and thick) at two temperatures (70 °F and 104 °F), subjected to a tandem axle dual tire at three speeds 25, 37 and 50 mph (40, 60 and 80 km/h). All pavement responses were determined using the 3D-Move Analysis program (Version 1.2) developed by University of Nevada, Reno. A new term called Dynamic Response Coefficient (DRC) was introduced in this study to address the variation in critical pavement responses due to dynamic loads as traditionally measured by the Dynamic Load Coefficient (DLC). While DLC represents the additional varying component of the tire load, DRC represents the additional varying component of the response value (standard deviation divided by mean response). In this study, DRC was compared with DLC for five different sites based on the roughness condition of the sites. Previous studies showed that DLC varies with vehicle speed and suspension types, and assumes a constant value for the whole pavement structure (lateral and vertical directions). On the other hand, in this study, DRC was found to be significantly varied with the asphalt pavement and function of pavement structure, road roughness conditions, temperatures, vehicle speeds, suspension types, and locations of the point of interest in the pavement. A major contribution of the study is that the variation of pavement responses due to dynamic load in a flexible pavement system can be predicted with generalized regression equations. Fitting parameters (R2) in the

  9. Theoretical investigation of heave dynamics of an air cushion vehicle bag and finger skirt

    Science.gov (United States)

    Chung, Joon

    This thesis describes a theoretical investigation of the nonlinear and linear heave dynamics of an air cushion vehicle (ACV) equipped with a bag and finger skirt system with the purpose of understanding the skirt's effect on the vehicle heave dynamics. Throughout the course of this work, the pure heave motion of a two dimensional section of the skirt is investigated using several mathematical models. Both the nonlinear and linearized analyses include a detailed model of the skirt geometry, which is modelled as a combination of inelastic membranes and links. Air flow processes from the bag to the cushion and from the cushion to the atmosphere are assumed to be quasisteady, and the bag and cushion volumes are modelled as lumped pneumatic capacitances. The modulation of the escaping cushion air by skirt-ground contact is also included. The nonlinear simulations reveal that characteristically nonlinear dynamical phenomena such as period doubling and chaos can be expected to occur during the normal operation of ACVs. Furthermore, a configuration representative of a 37 tonne vehicle shows a resonance at frequencies in the range for which humans are most sensitive. Although these results thus show that some aspects of the bag and finger skirt heave dynamics can be highly nonlinear, they indicate that under certain circumstances, standard linear techniques can yield useful insights. Results from the linear analysis suggest that changes in skirt geometry cannot be used to radically modify the undesirable heave response of the bag and finger skirt, but reducing the skirt mass is quite effective. The pneumatic capacitance of the bag and cushion volume proves to be an important factor in the heave response. In particular, it contributes to heave instability. The air compressibility also affects heave response at high frequencies, with the effect becoming more prominent as the flow rate is reduced. The importance of unsteady fan effects on ACV dynamics is investigated by the

  10. Influence of uneven rail irregularities on the dynamic response of the railway track using a three-dimensional model of the vehicle-track system

    Science.gov (United States)

    Naeimi, Meysam; Zakeri, Jabbar Ali; Esmaeili, Morteza; Shadfar, Morad

    2015-01-01

    A mathematical model of the vehicle-track interaction is developed to investigate the coupled behaviour of vehicle-track system, in the presence of uneven irregularities at left/right rails. The railway vehicle is simplified as a 3D multi-rigid-body model, and the track is treated as the two parallel beams on a layered discrete support system. Besides the car-body, the bogies and the wheel sets, the sleepers are assumed to have roll degree of freedom, in order to simulate the in-plane rotation of the components. The wheel-rail interface is treated using a nonlinear Hertzian contact model, coupling the mathematical equations of the vehicle-track systems. The dynamic interaction of the entire system is numerically studied in time domain, employing Newmark's integration method. The track irregularity spectra of both the left/right rails are taken into account, as the inputs of dynamic excitations. The dynamic responses of the track system induced by such irregularities are obtained, particularly in terms of the vertical (bounce) and roll displacements. The numerical model of the present research is validated using several benchmark models reported in the literature, for both the smooth and unsmooth track conditions. Four sample profiles of the measured rail irregularities are considered as the case studies of excitation sources, examining their influences on the dynamic behaviour of the coupled system. The results of numerical simulations demonstrate that the motion of track system is significantly influenced by the presence of uneven irregularities in left/right rails. Dynamic response of the sleepers in the roll direction becomes more sensitive to the rail irregularities, as the unevenness severity of the parallel profiles (quantitative difference between left and right rail spectra) is increased. The severe geometric deformation of the track in the bounce-pitch-roll directions is mainly related to such profile unevenness (cross-level) in left/right rails.

  11. Computational Simulation of Dynamic Response of Vehicle Tatra T815 and the Ground

    Science.gov (United States)

    Vlček, Jozef; Valašková, Veronika

    2016-10-01

    The effect of a moving load represents the actual problem which is analysed in engineering practice. The response of the vehicle and its dynamic effect on the pavement can be analysed by experimental or computational ways. The aim of this paper was to perform computer simulations of a vehicle-ground interaction. For this purpose, a half-part model of heavy lorry Tatra 815 and ground was modelled in computational programmes ADINA and PLAXIS based on FEM methods, utilizing analytical approaches. Two procedures were then selected for further calculations. The first one is based on the simplification of the stiffer pavement layers to the beam element supported by the springs simulating the subgrade layers using Winkler-Pasternak theory of elastic half-space. Modulus of subgrade reaction was determined in the standard programme trough the simulation of a plate load test. Second approach considers a multi-layered ground system with layers of different thicknesses and material properties. For comparison of outputs of both approaches, the same input values were used for every calculation procedure. Crucial parameter for the simulations was the velocity of the passing vehicle with regard to the ground response to the impulse of the pass. Lower velocities result in almost static response of the pavement, but higher velocities induce response that can be better described by the dynamic theory. For small deformations, an elastic material model seems to be sufficient to define the ground response to the moving load, but for larger deformations advanced material models for the ground environment would be more reliable.

  12. Dynamic surface tracking controller design for a constrained hypersonic vehicle based on disturbance observer

    Directory of Open Access Journals (Sweden)

    Fang Wang

    2017-05-01

    Full Text Available The tracking control problem of a flexible air-breathing hypersonic vehicle subjects to aerodynamic parameter uncertainty and input constraint is investigated by combining nonlinear disturbance observer and dynamic surface control. To design controller simply, a control-oriented model is firstly derived and divided into two subsystems, velocity subsystem and altitude subsystem based on the engineering backgrounds of flexible air-breathing hypersonic vehicle. In every subsystem, compounded disturbances are included to consider aerodynamic uncertainty and the effect of the flexible modes. Then, disturbance observer is not only used to handle the compounded disturbance but also to handle the input constraint, where the estimation error converges to a random small region through appropriately choosing the observer parameters. To sequel, the disturbance observer–based robust control scheme and the disturbance observer-based dynamic surface control scheme are developed for the velocity subsystem and altitude subsystem, respectively. Besides, novel filters are designed to alleviate the problem of “explosion of terms” induced by backstepping method. On the basis of Lyapunov stability theory, the presented control scheme can assure that tracking error converges to an arbitrarily small neighborhood around zero by rigorous theoretical analysis. At last, simulation result shows the effectiveness of the presented control method.

  13. Multi-objective four-dimensional vehicle motion planning in large dynamic environments.

    Science.gov (United States)

    Wu, Paul P-Y; Campbell, Duncan; Merz, Torsten

    2011-06-01

    This paper presents Multi-Step A∗ (MSA∗), a search algorithm based on A∗ for multi-objective 4-D vehicle motion planning (three spatial and one time dimensions). The research is principally motivated by the need for offline and online motion planning for autonomous unmanned aerial vehicles (UAVs). For UAVs operating in large dynamic uncertain 4-D environments, the motion plan consists of a sequence of connected linear tracks (or trajectory segments). The track angle and velocity are important parameters that are often restricted by assumptions and a grid geometry in conventional motion planners. Many existing planners also fail to incorporate multiple decision criteria and constraints such as wind, fuel, dynamic obstacles, and the rules of the air. It is shown that MSA∗ finds a cost optimal solution using variable length, angle, and velocity trajectory segments. These segments are approximated with a grid-based cell sequence that provides an inherent tolerance to uncertainty. The computational efficiency is achieved by using variable successor operators to create a multiresolution memory-efficient lattice sampling structure. The simulation studies on the UAV flight planning problem show that MSA∗ meets the time constraints of online replanning and finds paths of equivalent cost but in a quarter of the time (on average) of a vector neighborhood-based A∗.

  14. Second Order Sliding Mode Control Scheme for an Autonomous Underwater Vehicle with Dynamic Region Concept

    Directory of Open Access Journals (Sweden)

    Zool H. Ismail

    2015-01-01

    Full Text Available The main goal in developing closed loop control system for an Autonomous Underwater Vehicle (AUV is to make a robust vehicle from natural and exogenous perturbations such as wind, wave, and ocean currents. However a well-known robust control, for instance, Sliding Mode Controller (SMC, gives a chattering effect and it influences the stability of an AUV. Furthermore, some researchers combined other controls to get better result but it tends to present long computational time and causes large energy consumption. Thus, this paper proposed a Super Twisting Sliding Mode Controller (STSMC with dynamic region concept for an AUV. STSMC or a second order SMC is adopted as a robust controller which is free from chattering effect. Meanwhile, the implementation of dynamic region is useful to reduce the energy usage. As a result, the proposed controller obtains global asymptotic stability which is validated by using Lyapunov-like function. Moreover, some simulations present the efficiency of proposed controller. In conclusion, STSMC with region based control is effective to be applied for the robust tracking of an AUV. It contributes to give a fast response when handling the perturbations, short computational time, and low energy demand.

  15. [A novel vegetation index (MPRI) of corn canopy by vehicle-borne dynamic prediction].

    Science.gov (United States)

    Li, Shu-qiang; Li, Min-zan; Sun, Hong

    2014-06-01

    Ground-based remote sensing system is a significant way to understand the growth of corn and provide accurate and scientific data for precision agriculture. The vehicle-borne system is one of the most important tools for corn canopy monitoring. However, the vehicle-borne growth monitoring system cannot maintain steady operations due to the row spacing of corn. The reflectance of corn canopy, which was used to construct the model for the chlorophyll content, was disturbed by the reflectance of soil background. The background interference with the reflectance could not be removed effectively, which would result in a deviation in the growth monitoring. In order to overcome this problem, a novel vegetation index named MPRI was developed in the present paper. The tests were carried out by the vehicle-borne system on the cornfield. The sensors which configured the vehicle-borne system had 4 bands, being respectively 550, 650, 766 and 850 nm. It would obtain the spectral data while the vehicle moved along the row direction. The sampling rate was about 1 point per second. The GPS receiver obtained the location information at the same rate. MPRI was made up by the reflectance ratio of 660 and 550 nm. It was very effective to analyze the information about the reflectance of the canopy. The results of experiments showed that the MPRI of soil was the positive value and the MPRI of canopy was the negative value. So it is easier to distinguish the spectral information about soil and corn canopy by MPRI. The results indicated that: it had satisfactory forecasting accuracy for the chlorophyll content by using the MPRI on the moving monitoring. The R2 of the prediction model was about 0.72. The R2 Of the model of NDVI, which was used to represent the chlorophyll content, was only 0.24. It indicates that MPRI had good measurement results for the dynamic measurement process. It provided the novel measurement way to get the canopy reflectance spectra and the better vegetation index to

  16. Trajectory Learning for Robot Programming by Demonstration Using Hidden Markov Model and Dynamic Time Warping.

    Science.gov (United States)

    Vakanski, A; Mantegh, I; Irish, A; Janabi-Sharifi, F

    2012-08-01

    The main objective of this paper is to develop an efficient method for learning and reproduction of complex trajectories for robot programming by demonstration. Encoding of the demonstrated trajectories is performed with hidden Markov model, and generation of a generalized trajectory is achieved by using the concept of key points. Identification of the key points is based on significant changes in position and velocity in the demonstrated trajectories. The resulting sequences of trajectory key points are temporally aligned using the multidimensional dynamic time warping algorithm, and a generalized trajectory is obtained by smoothing spline interpolation of the clustered key points. The principal advantage of our proposed approach is utilization of the trajectory key points from all demonstrations for generation of a generalized trajectory. In addition, variability of the key points' clusters across the demonstrated set is employed for assigning weighting coefficients, resulting in a generalization procedure which accounts for the relevance of reproduction of different parts of the trajectories. The approach is verified experimentally for trajectories with two different levels of complexity.

  17. Inverse Force Determination on a Small Scale Launch Vehicle Model Using a Dynamic Balance

    Science.gov (United States)

    Ngo, Christina L.; Powell, Jessica M.; Ross, James C.

    2017-01-01

    A launch vehicle can experience large unsteady aerodynamic forces in the transonic regime that, while usually only lasting for tens of seconds during launch, could be devastating if structural components and electronic hardware are not designed to account for them. These aerodynamic loads are difficult to experimentally measure and even harder to computationally estimate. The current method for estimating buffet loads is through the use of a few hundred unsteady pressure transducers and wind tunnel test. Even with a large number of point measurements, the computed integrated load is not an accurate enough representation of the total load caused by buffeting. This paper discusses an attempt at using a dynamic balance to experimentally determine buffet loads on a generic scale hammer head launch vehicle model tested at NASA Ames Research Center's 11' x 11' transonic wind tunnel. To use a dynamic balance, the structural characteristics of the model needed to be identified so that the natural modal response could be and removed from the aerodynamic forces. A finite element model was created on a simplified version of the model to evaluate the natural modes of the balance flexures, assist in model design, and to compare to experimental data. Several modal tests were conducted on the model in two different configurations to check for non-linearity, and to estimate the dynamic characteristics of the model. The experimental results were used in an inverse force determination technique with a psuedo inverse frequency response function. Due to the non linearity, the model not being axisymmetric, and inconsistent data between the two shake tests from different mounting configuration, it was difficult to create a frequency response matrix that satisfied all input and output conditions for wind tunnel configuration to accurately predict unsteady aerodynamic loads.

  18. Dynamic vehicle-track interaction in switches and crossings and the influence of rail pad stiffness - field measurements and validation of a simulation model

    Science.gov (United States)

    Pålsson, Björn A.; Nielsen, Jens C. O.

    2015-06-01

    A model for simulation of dynamic interaction between a railway vehicle and a turnout (switch and crossing, S&C) is validated versus field measurements. In particular, the implementation and accuracy of viscously damped track models with different complexities are assessed. The validation data come from full-scale field measurements of dynamic track stiffness and wheel-rail contact forces in a demonstrator turnout that was installed as part of the INNOTRACK project with funding from the European Union Sixth Framework Programme. Vertical track stiffness at nominal wheel loads, in the frequency range up to 20 Hz, was measured using a rolling stiffness measurement vehicle (RSMV). Vertical and lateral wheel-rail contact forces were measured by an instrumented wheel set mounted in a freight car featuring Y25 bogies. The measurements were performed for traffic in both the through and diverging routes, and in the facing and trailing moves. The full set of test runs was repeated with different types of rail pad to investigate the influence of rail pad stiffness on track stiffness and contact forces. It is concluded that impact loads on the crossing can be reduced by using more resilient rail pads. To allow for vehicle dynamics simulations at low computational cost, the track models are discretised space-variant mass-spring-damper models that are moving with each wheel set of the vehicle model. Acceptable agreement between simulated and measured vertical contact forces at the crossing can be obtained when the standard GENSYS track model is extended with one ballast/subgrade mass under each rail. This model can be tuned to capture the large phase delay in dynamic track stiffness at low frequencies, as measured by the RSMV, while remaining sufficiently resilient at higher frequencies.

  19. Effect of Space Vehicle Structure Vibration on Control Moment Gyroscope Dynamics

    Science.gov (United States)

    Dobrinskaya, Tatiana

    2008-01-01

    Control Moment Gyroscopes (CMGs) are used for non-propulsive attitude control of satellites and space stations, including the International Space Station (ISS). CMGs could be essential for future long duration space missions due to the fact that they help to save propellant. CMGs were successfully tested on the ground for many years, and have been successfully used on satellites. However, operations have shown that the CMG service life on the ISS is significantly shorter than predicted. Since the dynamic environment of the ISS differs greatly from the nominal environment of satellites, it was important to analyze how operations specific to the station (dockings and undockings, huge solar array motion, crew exercising, robotic operations, etc) can affect the CMG performance. This task became even more important since the first CMG failure onboard the ISS. The CMG failure resulted in the limitation of the attitude control capabilities, more propellant consumption, and additional operational issues. Therefore, the goal of this work was to find out how the vibrations of a space vehicle structure, caused by a variety of onboard operations, can affect the CMG dynamics and performance. The equations of CMG motion were derived and analyzed for the case when the gyro foundation can vibrate in any direction. The analysis was performed for unbalanced CMG gimbals to match the CMG configuration on ISS. The analysis showed that vehicle structure vibrations can amplify and significantly change the CMG motion if the gyro gimbals are unbalanced in flight. The resonance frequencies were found. It was shown that the resonance effect depends on the magnitude of gimbal imbalance, on the direction of a structure vibration, and on gimbal bearing friction. Computer modeling results of CMG dynamics affected by the external vibration are presented. The results can explain some of the CMG vibration telemetry observed on ISS. This work shows that balancing the CMG gimbals decreases the effect

  20. Effect of Space Vehicle Structure Vibration on Control Moment Gyroscope Dynamics

    Science.gov (United States)

    Dobrinskaya, Tatiana

    2008-01-01

    Control Moment Gyroscopes (CMGs) are used for non-propulsive attitude control of satellites and space stations, including the International Space Station (ISS). CMGs could be essential for future long duration space missions due to the fact that they help to save propellant. CMGs were successfully tested on the ground for many years, and have been successfully used on satellites. However, operations have shown that the CMG service life on the ISS is significantly shorter than predicted. Since the dynamic environment of the ISS differs greatly from the nominal environment of satellites, it was important to analyze how operations specific to the station (dockings and undockings, huge solar array motion, crew exercising, robotic operations, etc) can affect the CMG performance. This task became even more important since the first CMG failure onboard the ISS. The CMG failure resulted in the limitation of the attitude control capabilities, more propellant consumption, and additional operational issues. Therefore, the goal of this work was to find out how the vibrations of a space vehicle structure, caused by a variety of onboard operations, can affect the CMG dynamics and performance. The equations of CMG motion were derived and analyzed for the case when the gyro foundation can vibrate in any direction. The analysis was performed for unbalanced CMG gimbals to match the CMG configuration on ISS. The analysis showed that vehicle structure vibrations can amplify and significantly change the CMG motion if the gyro gimbals are unbalanced in flight. The resonance frequencies were found. It was shown that the resonance effect depends on the magnitude of gimbal imbalance, on the direction of a structure vibration, and on gimbal bearing friction. Computer modeling results of CMG dynamics affected by the external vibration are presented. The results can explain some of the CMG vibration telemetry observed on ISS. This work shows that balancing the CMG gimbals decreases the effect

  1. Demonstration of zinc/air fuel battery to enhance the range and mission of fleet electric vehicles: Preliminary results in the refueling of a multicell module

    Science.gov (United States)

    Cooper, J. F.; Fleming, D.; Keene, L.; Maimoni, A.; Peterman, K.; Koopman, R.

    1994-08-01

    We report progress in an effort to develop and demonstrate a refuelable zinc/air battery for fleet electric vehicle applications. A refuelable module consisting of twelve bipolar cells with internal flow system has been refueled at rates of nearly 4 cells per minute, indicating a refueling time of 10 minutes for a 15 kW, 55 kWh battery. The module is refueled by entrainment of 0.5-mm particles in rapidly flowing electrolyte, which delivers the particles into hoppers above each cell in a parallel-flow hydraulic circuit. The concept of user-recovery is presented as an alternative to centralized service infrastructure during market entry.

  2. Application of Vehicle Dynamic Modeling in Uavs for Precise Determination of Exterior Orientation

    Science.gov (United States)

    Khaghani, M.; Skaloud, J.

    2016-06-01

    Advances in unmanned aerial vehicles (UAV) and especially micro aerial vehicle (MAV) technology together with increasing quality and decreasing price of imaging devices have resulted in growing use of MAVs in photogrammetry. The practicality of MAV mapping is seriously enhanced with the ability to determine parameters of exterior orientation (EO) with sufficient accuracy, in both absolute and relative senses (change of attitude between successive images). While differential carrier phase GNSS satisfies cm-level positioning accuracy, precise attitude determination is essential for both direct sensor orientation (DiSO) and integrated sensor orientation (ISO) in corridor mapping or in block configuration imaging over surfaces with low texture. Limited cost, size, and weight of MAVs represent limitations on quality of onboard navigation sensors and puts emphasis on exploiting full capacity of available resources. Typically short flying times (10-30 minutes) also limit the possibility of estimating and/or correcting factors such as sensor misalignment and poor attitude initialization of inertial navigation system (INS). This research aims at increasing the accuracy of attitude determination in both absolute and relative senses with no extra sensors onboard. In comparison to classical INS/GNSS setup, novel approach is presented here to integrated state estimation, in which vehicle dynamic model (VDM) is used as the main process model. Such system benefits from available information from autopilot and physical properties of the platform in enhancing performance of determination of trajectory and parameters of exterior orientation consequently. The navigation system employs a differential carrier phase GNSS receiver and a micro electro-mechanical system (MEMS) grade inertial measurement unit (IMU), together with MAV control input from autopilot. Monte-Carlo simulation has been performed on trajectories for typical corridor mapping and block imaging. Results reveal

  3. Demonstrating Universal Scaling in Quench Dynamics of a Yukawa One-Component Plasma

    CERN Document Server

    Langin, T K; Maksimovic, N; McQuillen, P; Pohl, T; Vrinceanu, D; Killian, T C

    2015-01-01

    The Yukawa one-component plasma (OCP) is a paradigm model for describing plasmas that contain one component of interest and one or more other components that can be treated as a neutralizing, screening background. In appropriately scaled units, interactions are characterized entirely by a screening parameter, $\\kappa$. As a result, systems of similar $\\kappa$ show the same dynamics, regardless of the underlying parameters (e.g., density and temperature). We demonstrate this behavior using ultracold neutral plasmas (UNP) created by photoionizing a cold ($T\\le10$ mK) gas. The ions in UNP systems are well described by the Yukawa model, with the electrons providing the screening. Creation of the plasma through photoionization can be thought of as a rapid quench from $\\kappa_{0}=\\infty$ to a final $\\kappa$ value set by the electron density and temperature. We demonstrate experimentally that the post-quench dynamics are universal in $\\kappa$ over a factor of 30 in density and an order of magnitude in temperature. R...

  4. Dynamic Sliding Mode Control Based on Multi-model Switching Laws for the Depth Control of an Autonomous Underwater Vehicle

    Directory of Open Access Journals (Sweden)

    Huanyin Zhou

    2015-07-01

    Full Text Available This manuscript presents an improved control algorithm, called Dynamic Sliding Mode Control based on Multiple Models Switching Laws (DSMC-MMSL, for the control of the depth of the studied Autonomous Underwater Vehicle (AUV system, the diving plane controller of which faces disturbances arising from the coupled states. The diving plane model is strongly coupled with the state variables, such as surge speeds and course angles. To achieve the desired dynamic performance, the proposed algorithm consists of two parts: the diving plane control part and the pitch control part, which is used to avoid large pitch angles. Some direct switching control laws are used for the two parts to avoid some impulse phenomena on the control executions. The error-states exponential decay is recommended to eliminate the chattering on the sliding surface. The DSMC-MMSL controller was successfully implemented and experimentally validated with the studied AUV system designed and built by Shenyang Institute of Automation. The results of some lake trials demonstrated that the depth control performances of the AUV system were as desired, and that the AUV system was robust enough for the coupled state variables under the DSMCMMSL algorithm control.

  5. New compliant strain gauges for self-sensing dynamic deformation of flapping wings on miniature air vehicles

    Science.gov (United States)

    Wissman, James; Perez-Rosado, Ariel; Edgerton, Alex; Levi, Benjamin M.; Karakas, Zeynep N.; Kujawski, Mark; Philipps, Alyssa; Papavizas, Nicholas; Fallon, Danielle; Bruck, Hugh A.; Smela, Elisabeth

    2013-08-01

    Over the past several years there has been an increasing interest in the development of miniature air vehicles (MAVs) with flapping wings. To allow these MAVs to adjust to changes in wind direction and to maximize their efficiency, it is desirable to monitor the deformation of the wing during flight. This paper presents a step in this direction, demonstrating the measurement of strain on the surface of the wing using minimally invasive compliant piezoresistive sensors. The strain gauges consisted of latex mixed with electrically conducting exfoliated graphite, and they were applied by spray coating. To calibrate the gauges, both static and dynamic testing up to 10 Hz were performed using cantilever structures. In tension the static sensitivity was a linear 0.4 Ω μɛ-1 and the gauge factor was 28; in compression, the gauge factor was -5. Although sensitivities in tension and compression differed by a factor of almost six, this was not reflected in the dynamic data, which followed the strain reversibly with little distortion. There was no attenuation with frequency, indicating a sufficiently small time constant for this application. The gauges were thin, compliant, and light enough to measure, without interference, deformations due to shape changes of the flexible wing associated with generating lift and thrust. During flapping the resistance closely tracked the generated thrust, measured on a test stand, with both signals tracing figure-8 loops as a function of wing position throughout each cycle.

  6. Optimal economy-based battery degradation management dynamics for fuel-cell plug-in hybrid electric vehicles

    Science.gov (United States)

    Martel, François; Kelouwani, Sousso; Dubé, Yves; Agbossou, Kodjo

    2015-01-01

    This work analyses the economical dynamics of an optimized battery degradation management strategy intended for plug-in hybrid electric vehicles (PHEVs) with consideration given to low-cost technologies, such as lead-acid batteries. The optimal management algorithm described herein is based on discrete dynamic programming theory (DDP) and was designed for the purpose of PHEV battery degradation management; its operation relies on simulation models using data obtained experimentally on a physical PHEV platform. These tools are first used to define an optimal management strategy according to the economical weights of PHEV battery degradation and the secondary energy carriers spent to manage its deleterious effects. We then conduct a sensitivity study of the proposed optimization process to the fluctuating economic parameters associated with the fuel and energy costs involved in the degradation management process. Results demonstrate the influence of each parameter on the process's response, including daily total operating costs and expected battery lifetime, as well as establish boundaries for useful application of the method; in addition, they provide a case for the relevance of inexpensive battery technologies, such as lead-acid batteries, for economy-centric PHEV applications where battery degradation is a major concern.

  7. Dynamic Sliding Mode Control Based on Multi-Model Switching Laws for the Depth Control of an Autonomous Underwater Vehicle

    Directory of Open Access Journals (Sweden)

    Huanyin Zhou

    2015-07-01

    Full Text Available This manuscript presents an improved control algorithm, called Dynamic Sliding Mode Control based on Multiple Models Switching Laws (DSMC-MMSL, for the control of the depth of the studied Autonomous Underwater Vehicle (AUV system, the diving plane controller of which faces disturbances arising from the coupled states. The diving plane model is strongly coupled with the state variables, such as surge speeds and course angles. To achieve the desired dynamic performance, the proposed algorithm consists of two parts: the diving plane control part and the pitch control part, which is used to avoid large pitch angles. Some direct switching control laws are used for the two parts to avoid some impulse phenomena on the control executions. The error-states exponential decay is recommended to eliminate the chattering on the sliding surface. The DSMC-MMSL controller was successfully implemented and experimentally validated with the studied AUV system designed and built by Shenyang Institute of Automation. The results of some lake trials demonstrated that the depth control performances of the AUV system were as desired, and that the AUV system was robust enough for the coupled state variables under the DSMC-MMSL algorithm control.

  8. Fair Energy Scheduling for Vehicle-to-Grid Networks Using Adaptive Dynamic Programming.

    Science.gov (United States)

    Xie, Shengli; Zhong, Weifeng; Xie, Kan; Yu, Rong; Zhang, Yan

    2016-08-01

    Research on the smart grid is being given enormous supports worldwide due to its great significance in solving environmental and energy crises. Electric vehicles (EVs), which are powered by clean energy, are adopted increasingly year by year. It is predictable that the huge charge load caused by high EV penetration will have a considerable impact on the reliability of the smart grid. Therefore, fair energy scheduling for EV charge and discharge is proposed in this paper. By using the vehicle-to-grid technology, the scheduler controls the electricity loads of EVs considering fairness in the residential distribution network. We propose contribution-based fairness, in which EVs with high contributions have high priorities to obtain charge energy. The contribution value is defined by both the charge/discharge energy and the timing of the action. EVs can achieve higher contribution values when discharging during the load peak hours. However, charging during this time will decrease the contribution values seriously. We formulate the fair energy scheduling problem as an infinite-horizon Markov decision process. The methodology of adaptive dynamic programming is employed to maximize the long-term fairness by processing online network training. The numerical results illustrate that the proposed EV energy scheduling is able to mitigate and flatten the peak load in the distribution network. Furthermore, contribution-based fairness achieves a fast recovery of EV batteries that have deeply discharged and guarantee fairness in the full charge time of all EVs.

  9. Multi-Objective Dynamic Economic Dispatch of Microgrid Systems Including Vehicle-to-Grid

    Directory of Open Access Journals (Sweden)

    Haitao Liu

    2015-05-01

    Full Text Available Based on the characteristics of electric vehicles (EVs, this paper establishes the load models of EVs under the autonomous charging mode and the coordinated charging and discharging mode. Integrating the EVs into a microgrid system which includes wind turbines (WTs, photovoltaic arrays (PVs, diesel engines (DEs, fuel cells (FCs and a storage battery (BS, this paper establishes multi-objective economic dispatch models of a microgrid, including the lowest operating cost, the least carbon dioxide emissions, and the lowest pollutant treatment cost. After converting the multi-objective functions to a single objective function by using the judgment matrix method, we analyze the dynamic economic dispatch of the microgrid system including vehicle-to-grid (V2G with an improved particle swarm optimization algorithm under different operation control strategies. With the example system, the proposed models and strategies are verified and analyzed. Simulation results show that the microgrid system with EVs under the coordinated charging and discharging mode has better operation economics than the autonomous charging mode. Meanwhile, the greater the load fluctuation is, the higher the operating cost of the microgrid system is.

  10. Dynamic thermal characteristics of heat pipe via segmented thermal resistance model for electric vehicle battery cooling

    Science.gov (United States)

    Liu, Feifei; Lan, Fengchong; Chen, Jiqing

    2016-07-01

    Heat pipe cooling for battery thermal management systems (BTMSs) in electric vehicles (EVs) is growing due to its advantages of high cooling efficiency, compact structure and flexible geometry. Considering the transient conduction, phase change and uncertain thermal conditions in a heat pipe, it is challenging to obtain the dynamic thermal characteristics accurately in such complex heat and mass transfer process. In this paper, a "segmented" thermal resistance model of a heat pipe is proposed based on thermal circuit method. The equivalent conductivities of different segments, viz. the evaporator and condenser of pipe, are used to determine their own thermal parameters and conditions integrated into the thermal model of battery for a complete three-dimensional (3D) computational fluid dynamics (CFD) simulation. The proposed "segmented" model shows more precise than the "non-segmented" model by the comparison of simulated and experimental temperature distribution and variation of an ultra-thin micro heat pipe (UMHP) battery pack, and has less calculation error to obtain dynamic thermal behavior for exact thermal design, management and control of heat pipe BTMSs. Using the "segmented" model, the cooling effect of the UMHP pack with different natural/forced convection and arrangements is predicted, and the results correspond well to the tests.

  11. Nonlinear dynamic behaviors of permanent magnet synchronous motors in electric vehicles caused by unbalanced magnetic pull

    Science.gov (United States)

    Xiang, Changle; Liu, Feng; Liu, Hui; Han, Lijin; Zhang, Xun

    2016-06-01

    Unbalanced magnetic pull (UMP) plays a key role in nonlinear dynamic behaviors of permanent magnet synchronous motors (PMSM) in electric vehicles. Based on Jeffcott rotor model, the stiffness characteristics of the rotor system of the PMSM are analyzed and the nonlinear dynamic behaviors influenced by UMP are investigated. In free vibration study, eigenvalue-based stability analysis for multiple equilibrium points is performed which offers an insight in system stiffness. Amplitude modulation effects are discovered of which the mechanism is explained and the period of modulating signal is carried out by phase analysis and averaging method. The analysis indicates that the effects are caused by the interaction of the initial phases of forward and backward whirling motions. In forced vibration study, considering dynamic eccentricity, frequency characteristics revealing softening type are obtained by harmonic balance method, and the stability of periodic solution is investigated by Routh-Hurwitz criterion. The frequency characteristics analysis indicates that the response amplitude is limited in the range between the amplitudes of the two kinds of equilibrium points. In the vicinity of the continuum of equilibrium points, the system hardly provides resistance to bending, and hence external disturbances easily cause loss of stability. It is useful for the design of the PMSM with high stability and low vibration and acoustic noise.

  12. Longitudinal control effectiveness and entry dynamics of a single-stage-to-orbit vehicle

    Science.gov (United States)

    Vinh, N. X.; Lin, C. F.

    1982-01-01

    The classical theory of flight dynamics for airplane longitudinal stability and control analysis was extended to the case of a hypervelocity reentry vehicle. This includes the elements inherent in supersonic and hypersonic flight such as the influence of the Mach number on aerodynamic characteristics, and the effect of the reaction control system and aerodynamic controls on the trim condition through a wide range of speed. Phugoid motion and angle of attack oscillation for typical cases of cruising flight, ballistic entry, and glide entry are investigated. In each case, closed form solutions for the variations in altitude, flight path angle, speed and angle of attack are obtained. The solutions explicitly display the influence of different regions design parameters and trajectory variables on the stability of the motion.

  13. Trajectory tracking control for underactuated unmanned surface vehicles with dynamic uncertainties

    Institute of Scientific and Technical Information of China (English)

    廖煜雷; 张铭钧; 万磊; 李晔

    2016-01-01

    The trajectory tracking control problem for underactuated unmanned surface vehicles (USV) was addressed, and the control system took account of the uncertain influences induced by model perturbation, external disturbance, etc. By introducing the reference, trajectory was generated by a virtual USV, and the error equation of trajectory tracking for USV was obtained, which transformed the tracking problem of underactuated USV into the stabilization problem of the trajectory tracking error equation. A backstepping adaptive sliding mode controller was proposed based on backstepping technology and method of dynamic slide model control. By means of theoretical analysis, it is proved that the proposed controller ensures that the solutions of closed loop system have the ultimate boundedness property. Simulation results are presented to illustrate the effectiveness of the proposed controller.

  14. Dynamic Response Analysis of an Asymmetric Coupled Vehicle-Track System Generated by Voided Elastic Two-Block Sleeper

    Directory of Open Access Journals (Sweden)

    Zhenxing He

    2016-01-01

    Full Text Available Based on vehicle-track coupled dynamic theory, a three-dimensional asymmetric vehicle-track coupling vibration model is developed to investigate the effect of voided elastic two-block sleepers on vehicle and track system dynamic responses. For the vehicle system, one car body, two frames, and four wheel sets are assumed to be rigid, with 35 degrees of freedom (DOF. For the track system, the rails and the concrete two-block sleepers are the main vibration components. The rails are modelled as Timoshenko beams, and the concrete two-block sleepers are assumed to be rigid mass with vertical and lateral movement. The pads under the rails and the rubber boots under the sleepers provide greater vertical and lateral elasticity for the track. The Hertz nonlinear elastic contact theory is used to calculate the normal wheel/rail force. The wheel/rail tangent creep force is first calculated using Kalker’s linear creep theory and then modified by the Shen-Hedrick-Elkins theory. The results show that the asymmetric voided elastic two-block sleepers have greater effects on the dynamic responses for fasteners and sleepers than on the car body and the wheel/rail forces under measured geometric irregularity and random irregularity. Two or more voided sleepers will greatly affect the vehicle running safety.

  15. Research, development, and demonstration of nickel-iron batteries for electric vehicle propulsion. Annual report for 1980

    Energy Technology Data Exchange (ETDEWEB)

    1981-03-01

    The FY 1980 program continued to involve full-size, prototype cell, module and battery fabrication and evaluation, aimed at advancing the technical capabilities of the nickel-iron battery, while simultaneously reducing its potential cost in materials and process areas. Improved Electroprecipitation Process (EPP) nickel electrodes of design thickness (2.5 mm) are now being prepared that display stable capacities of 23 to 25 Ah for the C/3 drain rate at 200+ test cycles. Iron electrodes of the composite-type are delivering 24 Ah at the target thickness (1.0 mm). Iron electrodes are displaying capacity stability for > 1000 test cycles in continuing 3 plate cell tests. Finished cells have delivered 57 to 61 Wh/kg at C/3, and have demonstrated cyclic stability to 500+ cycles at 80% depth of discharge profiles at Westinghouse. A 6-cell module that demonstrated 239 Ah, 1735 Wh, 48 Wh/kg at the C/3 drain rate has also been evaluated at the National Battery Test Laboratory, ANL. It operated for 327 test cycles, to a level of 161 Ah at the C/3 rate, before being removed from test. Reduction in nickel electrode swelling (and concurrent stack starvation), to improve cycling, continues to be an area of major effort to reach the final battery cycle life objectives. Pasted nickel electrodes continue to show promise for meeting the life objectives while, simultaneously, providing a low manufacturing cost. Refinements have occurred in the areas of cell hardware, module manifolding and cell interconnections. These improvements have been incorporated into the construction and testing of the cells and modules for this program. Temperature tests at 0/sup 0/C were performed on a 6-cell module and showed a decrease in capacity of only 25% in Ah and .29% in Wh as compared to 25/sup 0/C performance. Additional tests are planned to demonstrate performance at -15/sup 0/C and 40/sup 0/C.

  16. Max Launch Abort System (MLAS) Pad Abort Test Vehicle (PATV) II Attitude Control System (ACS) Integration and Pressurization Subsystem Dynamic Random Vibration Analysis

    Science.gov (United States)

    Ekrami, Yasamin; Cook, Joseph S.

    2011-01-01

    In order to mitigate catastrophic failures on future generation space vehicles, engineers at the National Aeronautics and Space Administration have begun to integrate a novel crew abort systems that could pull a crew module away in case of an emergency at the launch pad or during ascent. The Max Launch Abort System (MLAS) is a recent test vehicle that was designed as an alternative to the baseline Orion Launch Abort System (LAS) to demonstrate the performance of a "tower-less" LAS configuration under abort conditions. The MLAS II test vehicle will execute a propulsive coast stabilization maneuver during abort to control the vehicles trajectory and thrust. To accomplish this, the spacecraft will integrate an Attitude Control System (ACS) with eight hypergolic monomethyl hydrazine liquid propulsion engines that are capable of operating in a quick pulsing mode. Two main elements of the ACS include a propellant distribution subsystem and a pressurization subsystem to regulate the flow of pressurized gas to the propellant tanks and the engines. The CAD assembly of the Attitude Control System (ACS) was configured and integrated into the Launch Abort Vehicle (LAV) design. A dynamic random vibration analysis was conducted on the Main Propulsion System (MPS) helium pressurization panels to assess the response of the panel and its components under increased gravitational acceleration loads during flight. The results indicated that the panels fundamental and natural frequencies were farther from the maximum Acceleration Spectral Density (ASD) vibrations which were in the range of 150-300 Hz. These values will direct how the components will be packaged in the vehicle to reduce the effects high gravitational loads.

  17. HyLIFT-FLEX. ''Development and demonstration of flexible and scalable fuel cell power system for various material handling vehicles''. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-10-15

    The project has successfully developed and tested a new fuel cell system from H2 Logic in a tow tractor from MULAG. Based on the project results a positive decision has been taken on continuing commercialisation efforts. Next step will be a large scale demonstration of up to 100 units in a new project named HyLIFT-Europe that is expected to commence in early 2013, with support from the FCH-JU programme. Main efforts in the project have been the development of a new fuel cell system, named H2Drive from H2 Logic, and the integration and test in a standard battery powered COMET 3 towing tractor from MULAG. The system size is exactly the same as a standard battery box (DIN measures) and can be easily integrated into e.g. the MULAG vehicle or other electric powered material handling vehicles using the same battery size. Several R and D efforts on the fuel cell system have been conducted with the aim to reduce cost and improve efficiency, among others the following: 1) New air compressor sub-system and control - improving overall system efficiency with {approx}2,5%. 2) New simplified air-based compressor cooling sub-system. 3) New hydrogen compressor sub-system with improved efficiency and reduced cost. 4) New hydrogen inlet and outlet manifold sub-system - resulting in reduction of more than 50% of all sensor components in the fuel cell system. 5) New DC/DC converter with an average efficiency of 97% - a 3% improvement. 6) A new optimized hybrid system that meets the vehicle cycle requirements. In total the R and D efforts have improved the overall fuel cell system efficiency with 10% and helped to reduce costs with 33% compared to the previous generation. A first prototype of the developed H2Drive system has been constructed and integrated into the MULAG Towing Tractor. Only few modifications were made on the base vehicle, among others integration of cabin-heating, displays and motor control. Several internal tests were conducted at H2 Logic and MULAG before making a

  18. Navigation System Fault Diagnosis for Underwater Vehicle

    DEFF Research Database (Denmark)

    Falkenberg, Thomas; Gregersen, Rene Tavs; Blanke, Mogens

    2014-01-01

    This paper demonstrates fault diagnosis on unmanned underwater vehicles (UUV) based on analysis of structure of the nonlinear dynamics. Residuals are generated using dierent approaches in structural analysis followed by statistical change detection. Hypothesis testing thresholds are made signal b...

  19. Dynamic Coordinated Shifting Control of Automated Mechanical Transmissions without a Clutch in a Plug-In Hybrid Electric Vehicle

    Directory of Open Access Journals (Sweden)

    Xinlei Liu

    2012-08-01

    Full Text Available On the basis of the shifting process of automated mechanical transmissions (AMTs for traditional hybrid electric vehicles (HEVs, and by combining the features of electric machines with fast response speed, the dynamic model of the hybrid electric AMT vehicle powertrain is built up, the dynamic characteristics of each phase of shifting process are analyzed, and a control strategy in which torque and speed of the engine and electric machine are coordinatively controlled to achieve AMT shifting control for a plug-in hybrid electric vehicle (PHEV without clutch is proposed. In the shifting process, the engine and electric machine are well controlled, and the shift jerk and power interruption and restoration time are reduced. Simulation and real car test results show that the proposed control strategy can more efficiently improve the shift quality for PHEVs equipped with AMTs.

  20. Development and Evaluation of Sensor Concepts for Ageless Aerospace Vehicles: Report 3 - Design of the Concept Demonstrator

    Science.gov (United States)

    Abbott, David; Ables, Jon; Batten, Adam; Carpenter, David; Collings, Tony; Doyle, Briony; Dunlop, John; Edwards, Graeme; Farmer, Tony; Gaffney, Bruce; Hedley, Mark; Isaacs, Peter; Johnson, Mark; Joshi, Bhautik; Lewis, Chris; Poilton, Geoff; Price, Don; Prokopenko, Mikhail; Reda, Torsten; Rees, David; Scott, Andrew; Seneviratne, Sarath; Valencia, Philip; Wang, Peter; Whitnall, Denis

    2008-01-01

    This report provides an outline of the essential features of a Structural Health Monitoring Concept Demonstrator (CD) that will be constructed during the next eight months. It is emphasized that the design cannot be considered to be complete, and that design work will continue in parallel with construction and testing. A major advantage of the modular design is that small modules of the system can be developed, tested and modified before a commitment is made to full system development. The CD is expected to develop and evolve for a number of years after its initial construction. This first stage will, of necessity, be relatively simple and have limited capabilities. Later developments will improve all aspects of the functionality of the system, including sensing, processing, communications, intelligence and response. The report indicates the directions this later development will take.

  1. Dynamic Memory Cells Using MoS2 Field-Effect Transistors Demonstrating Femtoampere Leakage Currents.

    Science.gov (United States)

    Kshirsagar, Chaitanya U; Xu, Weichao; Su, Yang; Robbins, Matthew C; Kim, Chris H; Koester, Steven J

    2016-09-27

    Two-dimensional semiconductors such as transition-metal dichalcogenides (TMDs) are of tremendous interest for scaled logic and memory applications. One of the most promising TMDs for scaled transistors is molybdenum disulfide (MoS2), and several recent reports have shown excellent performance and scalability for MoS2 MOSFETs. An often overlooked feature of MoS2 is that its wide band gap (1.8 eV in monolayer) and high effective masses should lead to extremely low off-state leakage currents. These features could be extremely important for dynamic memory applications where the refresh rate is the primary factor affecting the power consumption. Theoretical predictions suggest that leakage currents in the 10(-18) to 10(-15) A/μm range could be possible, even in scaled transistor geometries. Here, we demonstrate the operation of one- and two-transistor dynamic memory circuits using MoS2 MOSFETs. We characterize the retention times in these circuits and show that the two-transistor memory cell reveals MoS2 MOSFETs leakage currents as low as 1.7 × 10(-15) A/μm, a value that is below the noise floor of conventional DC measurements. These results have important implications for the future use of MoS2 MOSFETs in low-power circuit applications.

  2. 动态车辆路径问题研究综述%Overview on Dynamic Vehicle Routing Problems

    Institute of Scientific and Technical Information of China (English)

    韩娟娟; 李永先

    2015-01-01

    The paper reviewed dynamic vehicle routing problem .DVRP was classified into SVRP and FVRP . The paper introduced research in recent years on models ,algorithms and simulationg of dynamic vehicle rou‐ting problems ,and summarizes characteristics of dynamic vehicle routing problem .Finally ,the paper pros‐pected future research orientations of dynamic vehicle routing problem .%指出了动态车辆路径问题是运筹学和组合优化领域的前沿研究方向,研究动态车辆路径问题具有重要的理论和现实意义。阐述了动态车辆问题(DVRP),根据动态信息的特征将动态车辆路径问题分为随机车辆路径问题(SVRP)和模糊车辆路径问题(FVRP)。从动态车辆路径问题的建模、算法和仿真优化三个方面分析了其研究成果,对现有研究的不足进行了探讨,提出了动态车辆路径问题的进一步研究方向。

  3. Comparison of Classical and Modern Uncertainty Qualification Methods for the Calculation of Critical Speeds in Railway Vehicle Dynamics

    DEFF Research Database (Denmark)

    Bigoni, Daniele; Engsig-Karup, Allan Peter; True, Hans

    2012-01-01

    . In this paper the methods are applied to a lowdimensional vehicle dynamical model composed by a two-axle bogie, which is connected to a car body by a lateral linear spring, a lateral damper and a torsional spring. Their characteristics are not deterministically defined, but they are defined by probability...

  4. Internal air flow analysis of a bladeless micro aerial vehicle hemisphere body using computational fluid dynamic

    Energy Technology Data Exchange (ETDEWEB)

    Othman, M. N. K., E-mail: najibkhir86@gmail.com, E-mail: zuradzman@unimap.edu.my, E-mail: hazry@unimap.edu.my, E-mail: khairunizam@unimap.edu.my, E-mail: shahriman@unimap.edu.my, E-mail: s.yaacob@unimap.edu.my, E-mail: syedfaiz@unimap.edu.my, E-mail: abadal@unimap.edu.my; Zuradzman, M. Razlan, E-mail: najibkhir86@gmail.com, E-mail: zuradzman@unimap.edu.my, E-mail: hazry@unimap.edu.my, E-mail: khairunizam@unimap.edu.my, E-mail: shahriman@unimap.edu.my, E-mail: s.yaacob@unimap.edu.my, E-mail: syedfaiz@unimap.edu.my, E-mail: abadal@unimap.edu.my; Hazry, D., E-mail: najibkhir86@gmail.com, E-mail: zuradzman@unimap.edu.my, E-mail: hazry@unimap.edu.my, E-mail: khairunizam@unimap.edu.my, E-mail: shahriman@unimap.edu.my, E-mail: s.yaacob@unimap.edu.my, E-mail: syedfaiz@unimap.edu.my, E-mail: abadal@unimap.edu.my; Khairunizam, Wan, E-mail: najibkhir86@gmail.com, E-mail: zuradzman@unimap.edu.my, E-mail: hazry@unimap.edu.my, E-mail: khairunizam@unimap.edu.my, E-mail: shahriman@unimap.edu.my, E-mail: s.yaacob@unimap.edu.my, E-mail: syedfaiz@unimap.edu.my, E-mail: abadal@unimap.edu.my; Shahriman, A. B., E-mail: najibkhir86@gmail.com, E-mail: zuradzman@unimap.edu.my, E-mail: hazry@unimap.edu.my, E-mail: khairunizam@unimap.edu.my, E-mail: shahriman@unimap.edu.my, E-mail: s.yaacob@unimap.edu.my, E-mail: syedfaiz@unimap.edu.my, E-mail: abadal@unimap.edu.my; Yaacob, S., E-mail: najibkhir86@gmail.com, E-mail: zuradzman@unimap.edu.my, E-mail: hazry@unimap.edu.my, E-mail: khairunizam@unimap.edu.my, E-mail: shahriman@unimap.edu.my, E-mail: s.yaacob@unimap.edu.my, E-mail: syedfaiz@unimap.edu.my, E-mail: abadal@unimap.edu.my; Ahmed, S. Faiz, E-mail: najibkhir86@gmail.com, E-mail: zuradzman@unimap.edu.my, E-mail: hazry@unimap.edu.my, E-mail: khairunizam@unimap.edu.my, E-mail: shahriman@unimap.edu.my, E-mail: s.yaacob@unimap.edu.my, E-mail: syedfaiz@unimap.edu.my, E-mail: abadal@unimap.edu.my [Centre of Excellence for Unmanned Aerial Systems, Universiti Malaysia Perlis, 01000 Kangar, Perlis (Malaysia); and others

    2014-12-04

    This paper explain the analysis of internal air flow velocity of a bladeless vertical takeoff and landing (VTOL) Micro Aerial Vehicle (MAV) hemisphere body. In mechanical design, before produce a prototype model, several analyses should be done to ensure the product's effectiveness and efficiency. There are two types of analysis method can be done in mechanical design; mathematical modeling and computational fluid dynamic. In this analysis, I used computational fluid dynamic (CFD) by using SolidWorks Flow Simulation software. The idea came through to overcome the problem of ordinary quadrotor UAV which has larger size due to using four rotors and the propellers are exposed to environment. The bladeless MAV body is designed to protect all electronic parts, which means it can be used in rainy condition. It also has been made to increase the thrust produced by the ducted propeller compare to exposed propeller. From the analysis result, the air flow velocity at the ducted area increased to twice the inlet air. This means that the duct contribute to the increasing of air velocity.

  5. Dynamic Stability Analysis of Blunt Body Entry Vehicles Using Time-Lagged Aftbody Pitching Moments

    Science.gov (United States)

    Kazemba, Cole D.; Braun, Robert D.; Schoenenberger, Mark; Clark, Ian G.

    2013-01-01

    This analysis defines an analytic model for the pitching motion of blunt bodies during atmospheric entry. The proposed model is independent of the pitch damping sum coefficient present in the standard formulation of the equations of motion describing pitch oscillations of a decelerating blunt body, instead using the principle of a time-lagged aftbody moment as the forcing function for oscillation divergence. Four parameters, all with intuitive physical relevance, are introduced to fully define the aftbody moment and the associated time delay. It is shown that the dynamic oscillation responses typical to blunt bodies can be produced using hysteresis of the aftbody moment in place of the pitch damping coefficient. The approach used in this investigation is shown to be useful in understanding the governing physical mechanisms for blunt body dynamic stability and in guiding vehicle and mission design requirements. A validation case study using simulated ballistic range test data is conducted. From this, parameter identification is carried out through the use of a least squares optimizing routine. Results show good agreement with the limited existing literature for the parameters identified, suggesting that the model proposed could be validated by an experimental ballistic range test series. The trajectories produced by the identified parameters were found to match closely those from the MER ballistic range tests for a wide array of initial conditions and can be identified with a reasonable number of ballistic range shots and computational effort.

  6. Dynamic stability test results on an 0.024 scale B-1 air vehicle

    Science.gov (United States)

    Beeman, R. R.

    1972-01-01

    Dynamic longitudinal and lateral-directional stability characteristics of the B-1 air vehicle were investigated in three wind tunnels at the Langley Research Center. The main rotary derivatives were obtained for an angle of attack range of -3 degrees to +16 degrees for a Mach number range of 0.2 to 2.16. Damping in roll data could not be obtained at the supersonic Mach numbers. The Langley 7 x 10 foot high speed tunnel, the 8 foot transonic pressure tunnel, and the 4 foot Unitary Plan wind tunnel were the test sites. An 0.024 scale light-weight model was used on a forced oscillation type balance. Test Reynolds number varied from 474,000/ft to 1,550,000/ft. through the Mach number range tested. The results showed that the dynamic stability characteristics of the model in pitch and roll were generally satisfactory up to an angle attack of about +6 degrees. In the wing sweep range from 15 to 25 degrees the positive damping levels in roll deteriorated rapidly above +2 degrees angle of attack. This reduction in roll damping is believed to be due to the onset of separation over the wing as stall is approached.

  7. Internal air flow analysis of a bladeless micro aerial vehicle hemisphere body using computational fluid dynamic

    Science.gov (United States)

    Othman, M. N. K.; Zuradzman, M. Razlan; Hazry, D.; Khairunizam, Wan; Shahriman, A. B.; Yaacob, S.; Ahmed, S. Faiz; Hussain, Abadalsalam T.

    2014-12-01

    This paper explain the analysis of internal air flow velocity of a bladeless vertical takeoff and landing (VTOL) Micro Aerial Vehicle (MAV) hemisphere body. In mechanical design, before produce a prototype model, several analyses should be done to ensure the product's effectiveness and efficiency. There are two types of analysis method can be done in mechanical design; mathematical modeling and computational fluid dynamic. In this analysis, I used computational fluid dynamic (CFD) by using SolidWorks Flow Simulation software. The idea came through to overcome the problem of ordinary quadrotor UAV which has larger size due to using four rotors and the propellers are exposed to environment. The bladeless MAV body is designed to protect all electronic parts, which means it can be used in rainy condition. It also has been made to increase the thrust produced by the ducted propeller compare to exposed propeller. From the analysis result, the air flow velocity at the ducted area increased to twice the inlet air. This means that the duct contribute to the increasing of air velocity.

  8. Vehicle path tracking by integrated chassis control

    Institute of Scientific and Technical Information of China (English)

    Saman Salehpour; Yaghoub Pourasad; Seyyed Hadi Taheri

    2015-01-01

    The control problem of trajectory based path following for passenger vehicles is studied. Comprehensive nonlinear vehicle model is utilized for simulation vehicle response during various maneuvers in MATLAB/Simulink. In order to follow desired path, a driver model is developed to enhance closed loop driver/vehicle model. Then, linear quadratic regulator (LQR) controller is developed which regulates direct yaw moment and corrective steering angle on wheels. Particle swam optimization (PSO) method is utilized to optimize the LQR controller for various dynamic conditions. Simulation results indicate that, over various maneuvers, side slip angle and lateral acceleration can be reduced by 10%and 15%, respectively, which sustain the vehicle stable. Also, anti-lock brake system is designed for longitudinal dynamics of vehicle to achieve desired slip during braking and accelerating. Proposed comprehensive controller demonstrates that vehicle steerability can increase by about 15% during severe braking by preventing wheel from locking and reducing stopping distance.

  9. EEG-based learning system for online motion sickness level estimation in a dynamic vehicle environment.

    Science.gov (United States)

    Lin, Chin-Teng; Tsai, Shu-Fang; Ko, Li-Wei

    2013-10-01

    Motion sickness is a common experience for many people. Several previous researches indicated that motion sickness has a negative effect on driving performance and sometimes leads to serious traffic accidents because of a decline in a person's ability to maintain self-control. This safety issue has motivated us to find a way to prevent vehicle accidents. Our target was to determine a set of valid motion sickness indicators that would predict the occurrence of a person's motion sickness as soon as possible. A successful method for the early detection of motion sickness will help us to construct a cognitive monitoring system. Such a monitoring system can alert people before they become sick and prevent them from being distracted by various motion sickness symptoms while driving or riding in a car. In our past researches, we investigated the physiological changes that occur during the transition of a passenger's cognitive state using electroencephalography (EEG) power spectrum analysis, and we found that the EEG power responses in the left and right motors, parietal, lateral occipital, and occipital midline brain areas were more highly correlated to subjective sickness levels than other brain areas. In this paper, we propose the use of a self-organizing neural fuzzy inference network (SONFIN) to estimate a driver's/passenger's sickness level based on EEG features that have been extracted online from five motion sickness-related brain areas, while either in real or virtual vehicle environments. The results show that our proposed learning system is capable of extracting a set of valid motion sickness indicators that originated from EEG dynamics, and through SONFIN, a neuro-fuzzy prediction model, we successfully translated the set of motion sickness indicators into motion sickness levels. The overall performance of this proposed EEG-based learning system can achieve an average prediction accuracy of ~82%.

  10. Distributed Algorithm for Computing the Vehicle Launch Dynamics under Interaction with the Medium

    Directory of Open Access Journals (Sweden)

    G. A. Shcheglov

    2015-01-01

    Full Text Available The paper describes a distributed algorithm and a structure of the software package for its implementation in which a program for computing the vehicle launch dynamics under interaction with the medium flow is complemented with a program to determine the unsteady hydrodynamic loads by the vortex element method.A distinctive feature of the developed system is that its local (running on a single computing core LEAVING program to calculate the launch dynamics runs together with concurrent (running on multiple computing cores MDVDD program to compute the unsteady vortex flow and hydrodynamic loads. The LEAVING program is the main one. It is launched app and then runs the MDVDD program in concurrent mode on the specified number of cores. Using MPI technology allows you to use a multiprocessor PC or a local network of multiple PCs to perform calculations. The equations of launcher spring-mass model dynamics and equations of vortex elements parameters evolution are integrated with the same time step. The interprogram communiaction in the step is provided asynchronously using the OS Windows Event mechanism (Events. Interfacing between LEAVING and MDVDD programs is built using the OS Windows FileMapping technology, which allows a specified data structure to be displayed and read to the fixed memory area.The paper provides analysis of acceleration achieved with parallel processing on different numbers of cores, and defines a parallelization degree of various operations. It shows that the parallelization efficiency of the developed algorithm is slower than in case of calculation of the rigid body flow. The causes of reduced efficiency are discussed.It is shown that the developed algorithm can be effectively used to solve problems on a small number of cores, e.g. on PC based on one or two quad-core processors.

  11. Summary of the LLNL gasoline spill demonstration - dynamic underground stripping project

    Energy Technology Data Exchange (ETDEWEB)

    Newmark, R.L.; Aines, R.D.

    1995-04-03

    Underground spills of volatile hydrocarbons (solvents or fuels) can be difficult to clean up when the hydrocarbons are present both above and below the water table and are found in relatively impermeable clays. Years of groundwater pumping may not completely remove the contamination. Researchers at Lawrence Livermore National Laboratory (LLNL) and the College of Engineering at the University of California at Berkeley (UCB) have collaborated to develop a technique called Dynamic Underground Stripping to remove localized underground spills in a relatively short time. The U.S. Department of Energy`s Office of Environmental Restoration and Waste Management has sponsored a full-scale demonstration of this technique at the LLNL gasoline spill site. When highly concentrated contamination is found above the standing water table, vacuum extraction has been very effective at both removing the contaminant and enhancing biological remediation through the addition of oxygen. Below the water table, however, these advantages cannot be obtained. For such sites where the contamination is too deep for excavation, there are currently no widely applicable cleanup methods. Dynamic Underground Stripping removes separate-phase organic contaminants below the water table by heating the subsurface above the boiling point of water, and then removing both contaminant and water by vacuum extraction. The high temperatures both convert the organic to vapor and enhance other removal paths by increasing diffusion and eliminating sorption. Because this method uses rapid, high-energy techniques in cleaning the soil, it requires an integrated system of underground monitoring and imaging methods to control and evaluate the process in real time.

  12. Development of an end-of-life vehicle recovery model using system dynamics and future research needs

    Science.gov (United States)

    Mohamad-Ali, N.; Ghazilla, R. A. R.; Abdul-Rashid, S. H.; Sakundarini, N.; Ahmad-Yazid, A.; Stephenie, L.

    2017-06-01

    The implementation of end-of-life vehicle (ELV) recovery policy in Malaysia has led vehicle manufacturers to look at different ways to improve design and development of vehicles. Nowadays, it is crucial to incorporate end-of-life (EOL) design strategies into the vehicle design in order to enhance the effectiveness of the ELV recovery network. Although recent studies have shown that product design has a significant effect on the product recovery rate, there is a lack of studies on how EOL design strategies affects the effectiveness of ELV recovery, particularly when there are dynamic changes in the behaviour of the product recovery network. Thus, in this study, we developed a preliminary model based on the system dynamics approach in order to predict the effectiveness of ELV recovery in response to dynamic changes of various factors (including EOL design strategies) in the business environment. We developed this model based on preliminary data that we had gathered from unstructured interviews with the key stakeholders of ELV management in Malaysia. We believe that our model will greatly benefit product designers in incorporating the appropriate EOL design strategies in order to boost ELV recovery effectiveness in Malaysia.

  13. Distributed Dynamic State Estimator, Generator Parameter Estimation and Stability Monitoring Demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Meliopoulos, Sakis [Georgia Inst. of Technology, Atlanta, GA (United States); Cokkinides, George [Georgia Inst. of Technology, Atlanta, GA (United States); Fardanesh, Bruce [New York Power Authority, NY (United States); Hedrington, Clinton [U.S. Virgin Islands Water and Power Authority (WAPA), St. Croix (U.S. Virgin Islands)

    2013-12-31

    This is the final report for this project that was performed in the period: October1, 2009 to June 30, 2013. In this project, a fully distributed high-fidelity dynamic state estimator (DSE) that continuously tracks the real time dynamic model of a wide area system with update rates better than 60 times per second is achieved. The proposed technology is based on GPS-synchronized measurements but also utilizes data from all available Intelligent Electronic Devices in the system (numerical relays, digital fault recorders, digital meters, etc.). The distributed state estimator provides the real time model of the system not only the voltage phasors. The proposed system provides the infrastructure for a variety of applications and two very important applications (a) a high fidelity generating unit parameters estimation and (b) an energy function based transient stability monitoring of a wide area electric power system with predictive capability. Also the dynamic distributed state estimation results are stored (the storage scheme includes data and coincidental model) enabling an automatic reconstruction and “play back” of a system wide disturbance. This approach enables complete play back capability with fidelity equal to that of real time with the advantage of “playing back” at a user selected speed. The proposed technologies were developed and tested in the lab during the first 18 months of the project and then demonstrated on two actual systems, the USVI Water and Power Administration system and the New York Power Authority’s Blenheim-Gilboa pumped hydro plant in the last 18 months of the project. The four main thrusts of this project, mentioned above, are extremely important to the industry. The DSE with the achieved update rates (more than 60 times per second) provides a superior solution to the “grid visibility” question. The generator parameter identification method fills an important and practical need of the industry. The “energy function” based

  14. An Autonomous Coil Alignment System for the Dynamic Wireless Charging of Electric Vehicles to Minimize Lateral Misalignment

    Directory of Open Access Journals (Sweden)

    Karam Hwang

    2017-03-01

    Full Text Available This paper proposes an autonomous coil alignment system (ACAS for electric vehicles (EVs with dynamic wireless charging (DWC to mitigate the reduction in received power caused by lateral misalignment between the source and load coils. The key component of the ACAS is a novel sensor coil design, which can detect the load coil’s left or right position relative to the source coil by observing the change in voltage phase. This allows the lateral misalignment to be estimated through the wireless power transfer (WPT system alone, which is a novel tracking method for vehicular applications. Once misalignment is detected, the vehicle’s lateral position is self-adjusted by an autonomous steering function. The feasibility of the overall operation of the ACAS was verified through simulation and experiments. In addition, an analysis based on experimental results was conducted, demonstrating that 26% more energy can be transferred during DWC with the ACAS, just by keeping the vehicle’s load coil aligned with the source coil.

  15. Navigation System for Reusable Launch Vehicle

    OpenAIRE

    Schlotterer, Markus

    2008-01-01

    PHOENIX is a downscaled experimental vehicle to demonstrate automatic landing capabilities of future Reusable Launch Vehicles (RLVs). PHOENIX has flown in May 2004 at NEAT (North European Aerospace Test range) in Vidsel, Sweden. As the shape of the vehicle has been designed for re-entry, the dynamics are very high and almost unstable. This requires a fast and precise GNC system. This paper describes the navigation system and the navigation filter of PHOENIX. The system is introduced and the h...

  16. Demonstrating an Order-of-Magnitude Sampling Enhancement in Molecular Dynamics Simulations of Complex Protein Systems.

    Science.gov (United States)

    Pan, Albert C; Weinreich, Thomas M; Piana, Stefano; Shaw, David E

    2016-03-01

    Molecular dynamics (MD) simulations can describe protein motions in atomic detail, but transitions between protein conformational states sometimes take place on time scales that are infeasible or very expensive to reach by direct simulation. Enhanced sampling methods, the aim of which is to increase the sampling efficiency of MD simulations, have thus been extensively employed. The effectiveness of such methods when applied to complex biological systems like proteins, however, has been difficult to establish because even enhanced sampling simulations of such systems do not typically reach time scales at which convergence is extensive enough to reliably quantify sampling efficiency. Here, we obtain sufficiently converged simulations of three proteins to evaluate the performance of simulated tempering, a member of a widely used class of enhanced sampling methods that use elevated temperature to accelerate sampling. Simulated tempering simulations with individual lengths of up to 100 μs were compared to (previously published) conventional MD simulations with individual lengths of up to 1 ms. With two proteins, BPTI and ubiquitin, we evaluated the efficiency of sampling of conformational states near the native state, and for the third, the villin headpiece, we examined the rate of folding and unfolding. Our comparisons demonstrate that simulated tempering can consistently achieve a substantial sampling speedup of an order of magnitude or more relative to conventional MD.

  17. Learning robotic eye-arm-hand coordination from human demonstration: a coupled dynamical systems approach.

    Science.gov (United States)

    Lukic, Luka; Santos-Victor, José; Billard, Aude

    2014-04-01

    We investigate the role of obstacle avoidance in visually guided reaching and grasping movements. We report on a human study in which subjects performed prehensile motion with obstacle avoidance where the position of the obstacle was systematically varied across trials. These experiments suggest that reaching with obstacle avoidance is organized in a sequential manner, where the obstacle acts as an intermediary target. Furthermore, we demonstrate that the notion of workspace travelled by the hand is embedded explicitly in a forward planning scheme, which is actively involved in detecting obstacles on the way when performing reaching. We find that the gaze proactively coordinates the pattern of eye-arm motion during obstacle avoidance. This study provides also a quantitative assessment of the coupling between the eye-arm-hand motion. We show that the coupling follows regular phase dependencies and is unaltered during obstacle avoidance. These observations provide a basis for the design of a computational model. Our controller extends the coupled dynamical systems framework and provides fast and synchronous control of the eyes, the arm and the hand within a single and compact framework, mimicking similar control system found in humans. We validate our model for visuomotor control of a humanoid robot.

  18. A mechanical brake hardware-in-the-loop simulation of a railway vehicle that accounts for hysteresis and pneumatic cylinder dynamics

    Directory of Open Access Journals (Sweden)

    Dong-Chan Lee

    2015-11-01

    Full Text Available A brake hardware-in-the-loop simulation system for a railway vehicle provides an effective platform for testing the braking performance under various dangerous braking conditions. However, in general, four-brake calipers are required to implement a mechanical brake system for one car. In this article, we implement a brake hardware-in-the-loop simulation system only with one brake caliper and three air tanks accounting for hysteresis and pneumatic cylinder dynamics, ultimately saving installation space and reducing financial budget costs. Since the brake caliper has a high nonlinearity, such as hysteresis resulting from friction and from the precompressed spring of the brake cylinder, we measured the hysteresis of the brake caliper clamping force for a mechanical brake system using loadcells, based on which a mathematical model was constructed for the hysteresis of the clamping force between the brake pad and the disk. Moreover, the pneumatic cylinder dynamics are identified and are implemented in three air tanks, together with hysteresis nonlinearity. The proposed brake hardware-in-the-loop simulation system is applied to the wheel-slide protection simulation of a railway vehicle with an initial speed of 80 km/h and demonstrated experimentally accounting for the hysteresis and brake cylinder dynamics.

  19. On-Track Testing as a Validation Method of Computational Fluid Dynamic Simulations of a Formula SAE Vehicle

    Science.gov (United States)

    Weingart, Robert

    This thesis is about the validation of a computational fluid dynamics simulation of a ground vehicle by means of a low-budget coast-down test. The vehicle is built to the standards of the 2014 Formula SAE rules. It is equipped with large wings in the front and rear of the car; the vertical loads on the tires are measured by specifically calibrated shock potentiometers. The coast-down test was performed on a runway of a local airport and is used to determine vehicle specific coefficients such as drag, downforce, aerodynamic balance, and rolling resistance for different aerodynamic setups. The test results are then compared to the respective simulated results. The drag deviates about 5% from the simulated to the measured results. The downforce numbers show a deviation up to 18% respectively. Moreover, a sensitivity analysis of inlet velocities, ride heights, and pitch angles was performed with the help of the computational simulation.

  20. Three-dimensional path planning for unmanned aerial vehicle based on interfered fluid dynamical system

    Directory of Open Access Journals (Sweden)

    Wang Honglun

    2015-02-01

    Full Text Available This paper proposes a method for planning the three-dimensional path for low-flying unmanned aerial vehicle (UAV in complex terrain based on interfered fluid dynamical system (IFDS and the theory of obstacle avoidance by the flowing stream. With no requirement of solutions to fluid equations under complex boundary conditions, the proposed method is suitable for situations with complex terrain and different shapes of obstacles. Firstly, by transforming the mountains, radar and anti-aircraft fire in complex terrain into cylindrical, conical, spherical, parallelepiped obstacles and their combinations, the 3D low-flying path planning problem is turned into solving streamlines for obstacle avoidance by fluid flow. Secondly, on the basis of a unified mathematical expression of typical obstacle shapes including sphere, cylinder, cone and parallelepiped, the modulation matrix for interfered fluid dynamical system is constructed and 3D streamlines around a single obstacle are obtained. Solutions to streamlines with multiple obstacles are then derived using weighted average of the velocity field. Thirdly, extra control force method and virtual obstacle method are proposed to deal with the stagnation point and the case of obstacles’ overlapping respectively. Finally, taking path length and flight height as sub-goals, genetic algorithm (GA is used to obtain optimal 3D path under the maneuverability constraints of the UAV. Simulation results show that the environmental modeling is simple and the path is smooth and suitable for UAV. Theoretical proof is also presented to show that the proposed method has no effect on the characteristics of fluid avoiding obstacles.

  1. Three-dimensional path planning for unmanned aerial vehicle based on interfered fluid dynamical system

    Institute of Scientific and Technical Information of China (English)

    Wang Honglun; Lyu Wentao; Yao Peng; Liang Xiao; Liu Chang

    2015-01-01

    This paper proposes a method for planning the three-dimensional path for low-flying unmanned aerial vehicle (UAV) in complex terrain based on interfered fluid dynamical system (IFDS) and the theory of obstacle avoidance by the flowing stream. With no requirement of solutions to fluid equations under complex boundary conditions, the proposed method is suitable for situations with complex terrain and different shapes of obstacles. Firstly, by transforming the mountains, radar and anti-aircraft fire in complex terrain into cylindrical, conical, spherical, parallelepiped obstacles and their combinations, the 3D low-flying path planning problem is turned into solving streamlines for obstacle avoidance by fluid flow. Secondly, on the basis of a unified mathematical expression of typical obstacle shapes including sphere, cylinder, cone and parallelepiped, the modulation matrix for interfered fluid dynamical system is constructed and 3D streamlines around a single obstacle are obtained. Solutions to streamlines with multiple obstacles are then derived using weighted average of the velocity field. Thirdly, extra control force method and virtual obstacle method are proposed to deal with the stagnation point and the case of obstacles’ overlapping respectively. Finally, taking path length and flight height as sub-goals, genetic algorithm (GA) is used to obtain optimal 3D path under the maneuverability constraints of the UAV. Simulation results show that the environmental modeling is simple and the path is smooth and suitable for UAV. Theoretical proof is also presented to show that the proposed method has no effect on the characteristics of fluid avoiding obstacles.

  2. Dynamic Modeling and Investigation of Maneuver Characteristics of A Deep-Sea Manned Submarine Vehicle

    Institute of Scientific and Technical Information of China (English)

    XIE Jun-yuan; XU Wen-bo; ZHANG Hua; XU Peng-fei; CUI Wei-cheng

    2009-01-01

    A deep-sea Manned Submarine Vehicle (MSV) is usually required to move at a low forward speed and a low rota- tional speed when it executes investigation tasks. In this condition, the motion is in large drift angles, and the maneuver- ability hydrodynamic forces cannot be expressed properly in the conventional mathematical model of submersible motion. In this paper, firstly, a general equation of MSV with six-freedom motion is presented, and the numerical simulation of descent/ascent motion and helix motion is conducted to reveal the general maneuver characteristics of MSV. Secondly, according to the data of captive model tests of large drift angles of MSV, the regression analysis of position hydrodynamic forces and rotation hydrodynamic forces is carried out, and the resuhs of regression analysis of maneuverabihty hydrody-namic characteristics are analyzed to reveal the special maneuver characteristics. Thirdly, a special new mathematical model of MSV with the whole range of drift angles motion is presented, which can be used to predict hydrodynamic per-formance of motion in the 0°~180° range of drift angles. The resuhs are applied to the design of maneuverability hydro- dynamic forces, development of control system and simulator of a practical MSV.

  3. A Dynamic Bioinspired Neural Network Based Real-Time Path Planning Method for Autonomous Underwater Vehicles.

    Science.gov (United States)

    Ni, Jianjun; Wu, Liuying; Shi, Pengfei; Yang, Simon X

    2017-01-01

    Real-time path planning for autonomous underwater vehicle (AUV) is a very difficult and challenging task. Bioinspired neural network (BINN) has been used to deal with this problem for its many distinct advantages: that is, no learning process is needed and realization is also easy. However, there are some shortcomings when BINN is applied to AUV path planning in a three-dimensional (3D) unknown environment, including complex computing problem when the environment is very large and repeated path problem when the size of obstacles is bigger than the detection range of sensors. To deal with these problems, an improved dynamic BINN is proposed in this paper. In this proposed method, the AUV is regarded as the core of the BINN and the size of the BINN is based on the detection range of sensors. Then the BINN will move with the AUV and the computing could be reduced. A virtual target is proposed in the path planning method to ensure that the AUV can move to the real target effectively and avoid big-size obstacles automatically. Furthermore, a target attractor concept is introduced to improve the computing efficiency of neural activities. Finally, some experiments are conducted under various 3D underwater environments. The experimental results show that the proposed BINN based method can deal with the real-time path planning problem for AUV efficiently.

  4. A Dynamic Bioinspired Neural Network Based Real-Time Path Planning Method for Autonomous Underwater Vehicles

    Directory of Open Access Journals (Sweden)

    Jianjun Ni

    2017-01-01

    Full Text Available Real-time path planning for autonomous underwater vehicle (AUV is a very difficult and challenging task. Bioinspired neural network (BINN has been used to deal with this problem for its many distinct advantages: that is, no learning process is needed and realization is also easy. However, there are some shortcomings when BINN is applied to AUV path planning in a three-dimensional (3D unknown environment, including complex computing problem when the environment is very large and repeated path problem when the size of obstacles is bigger than the detection range of sensors. To deal with these problems, an improved dynamic BINN is proposed in this paper. In this proposed method, the AUV is regarded as the core of the BINN and the size of the BINN is based on the detection range of sensors. Then the BINN will move with the AUV and the computing could be reduced. A virtual target is proposed in the path planning method to ensure that the AUV can move to the real target effectively and avoid big-size obstacles automatically. Furthermore, a target attractor concept is introduced to improve the computing efficiency of neural activities. Finally, some experiments are conducted under various 3D underwater environments. The experimental results show that the proposed BINN based method can deal with the real-time path planning problem for AUV efficiently.

  5. Intelligent Autonomous Primary 3D Feature Extraction in Vehicle System Dynamics' Analysis: Theory and Application

    Directory of Open Access Journals (Sweden)

    Annamária R. Várkonyi-Kóczy

    2008-01-01

    Full Text Available 3D model reconstruction plays a very important role in computer vision as wellas in different engineering applications. The determination of the 3D model from multipleimages is of key importance. One of the most important difficulties in autonomous 3Dreconstruction is the (automatic selection of the ‘significant’ points which carryinformation about the shape of the 3D bodies i.e. are characteristic from the model point ofview. Another problem to be solved is the point correspondence matching in differentimages.In this paper a 3D reconstruction technique is introduced, which is capable to determinethe 3D model of a scene without any external (human intervention. The method is based onrecent results of image processing, epipolar geometry, and intelligent and soft techniques.Possible applications of the presented algorithm in vehicle system dynamics are alsopresented. The results can be applied advantageously at other engineering fields, like carcrashanalysis, robot guiding, object recognition, supervision of 3D scenes, etc,. as well.

  6. Direct observation of key photoinduced dynamics in a potential nano-delivery vehicle of cancer drugs.

    Science.gov (United States)

    Sardar, Samim; Chaudhuri, Siddhi; Kar, Prasenjit; Sarkar, Soumik; Lemmens, Peter; Pal, Samir Kumar

    2015-01-01

    In recent times, significant achievements in the use of zinc oxide (ZnO) nanoparticles (NPs) as delivery vehicles of cancer drugs have been made. The present study is an attempt to explore the key photoinduced dynamics in ZnO NPs upon complexation with a model cancer drug protoporphyrin IX (PP). The nanohybrid has been characterized by FTIR, Raman scattering and UV-Vis absorption spectroscopy. Picosecond-resolved Förster resonance energy transfer (FRET) from the defect mediated emission of ZnO NPs to PP has been used to study the formation of the nanohybrid at the molecular level. Picosecond-resolved fluorescence studies of PP-ZnO nanohybrids reveal efficient electron migration from photoexcited PP to ZnO, eventually enhancing the ROS activity. The dichlorofluorescin (DCFH) oxidation and no oxidation of luminol in PP/PP-ZnO nanohybrids upon green light illumination unravel that the nature of ROS is essentially singlet oxygen rather than superoxide anions. Surface mediated photocatalysis of methylene blue (MB) in an aqueous solution of the nanohybrid has also been investigated. Direct evidence of the role of electron transfer as a key player in enhanced ROS generation from the nanohybrid is also clear from the photocurrent measurement studies. We have also used the nanohybrid in a model photodynamic therapy application in a light sensitized bacteriological culture experiment.

  7. A Dynamic Bioinspired Neural Network Based Real-Time Path Planning Method for Autonomous Underwater Vehicles

    Science.gov (United States)

    2017-01-01

    Real-time path planning for autonomous underwater vehicle (AUV) is a very difficult and challenging task. Bioinspired neural network (BINN) has been used to deal with this problem for its many distinct advantages: that is, no learning process is needed and realization is also easy. However, there are some shortcomings when BINN is applied to AUV path planning in a three-dimensional (3D) unknown environment, including complex computing problem when the environment is very large and repeated path problem when the size of obstacles is bigger than the detection range of sensors. To deal with these problems, an improved dynamic BINN is proposed in this paper. In this proposed method, the AUV is regarded as the core of the BINN and the size of the BINN is based on the detection range of sensors. Then the BINN will move with the AUV and the computing could be reduced. A virtual target is proposed in the path planning method to ensure that the AUV can move to the real target effectively and avoid big-size obstacles automatically. Furthermore, a target attractor concept is introduced to improve the computing efficiency of neural activities. Finally, some experiments are conducted under various 3D underwater environments. The experimental results show that the proposed BINN based method can deal with the real-time path planning problem for AUV efficiently. PMID:28255297

  8. Dynamic origin-to-destination routing of wirelessly connected, autonomous vehicles on a congested network

    Science.gov (United States)

    Davis, L. C.

    2017-07-01

    Up-to-date information wirelessly communicated among vehicles can be used to select the optimal route between a given origin and destination. To elucidate how to make use of such information, simulations are performed for autonomous vehicles traveling on a square lattice of roads. All the possible routes between the origin and the destination (without backtracking) are of the same length. Congestion is the only determinant of delay. At each intersection, right-of-way is given to the closest vehicle. There are no traffic lights. Trip times of a subject vehicle are recorded for various initial conditions using different routing algorithms. Surprisingly, the simplest algorithm, which is based on the total number of vehicles on a route, is as good as one based on computing travel times from the average velocity of vehicles on each road segment.

  9. Dynamic origin-to-destination routing of wirelessly connected, autonomous vehicles on a congested network

    CERN Document Server

    Davis, L C

    2016-01-01

    Up-to-date information wirelessly communicated among vehicles can be used to select the optimal route between a given origin and destination. To elucidate how to make use of such information, simulations are performed for autonomous vehicles traveling on a square lattice of roads. All the possible routes between the origin and the destination (without backtracking) are of the same length. Congestion is the only determinant of delay. At each intersection, right-of-way is given to the closest vehicle. There are no traffic lights. Trip times of a subject vehicle are recorded for various initial conditions using different routing algorithms. Surprisingly, the simplest algorithm, which is based on the total number of vehicles on a route, is as good as one based on computing travel times from the average velocity of vehicles on each road segment.

  10. Robust Stability and Control of Multi-Body Ground Vehicles with Uncertain Dynamics and Failures

    Science.gov (United States)

    2010-01-01

    Modeling for Heavy Articulated Tractor Semi- Trailer Vehicle 2.2.3.1 Rollover Index (RI) for A single Unit Vehicle 2.2.3.2...increasing complexity to capture Roll Over phenomenon and Other Performance and Ride Quality requirements. In this connection, first simple ` Bicycle ...methodology to a specific heavy articulated vehicle with tractor semi- trailer shows that a single active anti-roll bar system at the trailer unit gives

  11. Study on dynamic optimization of the double railway suspended vehicle for automatic transportation in the welding shop

    Institute of Scientific and Technical Information of China (English)

    Huang Dawei; Gao Xiuhua; Xing Hao; Liu Hongxue; Han Yanhe

    2007-01-01

    The 2DOF dynamic equations of the double railway suspended vehicle for automatic transportation in the welding shop are established. The sensitivities are analyzed. The parameter design is researched in ADAMS in terms of the inner railway radius, wheelbase, gauge, girder length of the double railway suspended vehicle for automatic transportation in the welding product line. The mutual-restriction among the design variables is discussed and the selective ranges of the variables are confirmed. The result shows that the stability of the double railway suspended vehicle for automatic transportation in the welding product line depends on parameters of the inner railway radius, wheelbase, gauge, girder length. The optimal results of the optimal objective and design variables have research significance for the virtual prototype of the double suspension railway automation vehicle. The optimal results are input into the simulation model iteratively and the simulation results are fed back to the physical prototype. The veracity and reliability of performance forecast are improved so that the manufacture cost of the double suspension railway automation vehicle is reduced significantly.

  12. A study of aeroelastic and structural dynamic effects in multi-rotor systems with application to hybrid heavy lift vehicles

    Science.gov (United States)

    Friedmann, P. P.

    1984-01-01

    An aeroelastic model suitable for the study of aeroelastic and structural dynamic effects in multirotor vehicles simulating a hybrid heavy lift vehicle was developed and applied to the study of a number of diverse problems. The analytical model developed proved capable of modeling a number of aeroelastic problems, namely: (1) isolated blade aeroelastic stability in hover and forward flight, (2) coupled rotor/fuselage aeromechanical problem in air or ground resonance, (3) tandem rotor coupled rotor/fuselage problems, and (4) the aeromechanical stability of a multirotor vehicle model representing a hybrid heavy lift airship (HHLA). The model was used to simulate the ground resonance boundaries of a three bladed hingeless rotor model, including the effect of aerodynamic loads, and the theoretical predictions compared well with experimental results. Subsequently the model was used to study the aeromechanical stability of a vehicle representing a hybrid heavy lift airship, and potential instabilities which could occur for this type of vehicle were identified. The coupling between various blade, supporting structure and rigid body modes was identified.

  13. Real-Time and High-Fidelity Simulation Environment for Autonomous Ground Vehicle Dynamics

    Science.gov (United States)

    Cameron, Jonathan; Myint, Steven; Kuo, Calvin; Jain, Abhi; Grip, Havard; Jayakumar, Paramsothy; Overholt, Jim

    2013-01-01

    This paper reports on a collaborative project between U.S. Army TARDEC and Jet Propulsion Laboratory (JPL) to develop a unmanned ground vehicle (UGV) simulation model using the ROAMS vehicle modeling framework. Besides modeling the physical suspension of the vehicle, the sensing and navigation of the HMMWV vehicle are simulated. Using models of urban and off-road environments, the HMMWV simulation was tested in several ways, including navigation in an urban environment with obstacle avoidance and the performance of a lane change maneuver.

  14. Dynamic performances of cattle transporting vehicle on Scandinavian roads and behavioural response of animals.

    Science.gov (United States)

    Wikner, I; Gebresenbet, G; Tolo, E

    2003-03-01

    Driving performance, air quality in the vehicle, and handling during loading and unloading are the main factors, which could affect animal welfare. During transport of animals from farms to abattoirs, animals on the vehicle are subjected to vibrations in all directions. Performances of a typical vehicle for cattle transport have been studied under field commercial conditions. During the experiment, tri-axial vibrations on the vehicle, as well as velocity, slope and position were measured. The animals were video recorded for behavioral analyses. Geographical positions, speed and slope of roads were recorded using, GPS. Measurements were made with and without animals on the vehicle. The roads in the region are narrow almost everywhere, but rather plane and of good quality. Three road types were identified: straight and plain, curvy and graveled roads. Events such as sudden stops and curves were observed and noted. Vibration levels in tri-axial directions have been measured and analysed for different speeds and road types both when the vehicle was fully loaded and unloaded. There is a significant difference between the performances of the vehicle when loaded and unloaded. Very high vibrations values have been noted during the empty driving and these values were reduced by up to 9 times when the vehicle was loaded. Less vibrations amplitudes were observed and animals were calmer on ferry transport than on road transport. It has also been noted that animals prefer to stand perpendicular to the direction of vehicle's motion during transport.

  15. Effects of profile wear on wheel–rail contact conditions and dynamic interaction of vehicle and turnout

    Directory of Open Access Journals (Sweden)

    Jingmang Xu

    2016-01-01

    Full Text Available Severe wear is a common damage mechanism in railway turnouts, which strongly affects the dynamic performance of railway vehicles and maintenance costs of tracks. This article explores the effects of profile wear on contact behaviors in the wheel–rail/switch contact and dynamic interaction, and nominal and measured worn turnout rail profiles are used as boundary conditions of wheel–rail contact. The calculation of the dynamic loads and the resultant contact stresses and internal stresses makes it possible to rationally design railway turnouts and correctly select the material to be applied for their components. For these reasons, the multi-body system SIMPACK and finite element software ANSYS are used to calculate the features of load and subsequently distributions of contact stresses and internal stresses in the regions of wheel–turnout components. The results show that profile wear disturbs the distribution of wheel–rail contact point pairs, changes the positions of wheel–rail contact points along the longitudinal direction, and affects the dynamic interaction of vehicle and turnout. For the measured profile in this article, profile wear aggravates vertical dynamic responses significantly but improves lateral dynamic responses. Profile wear disturbs the normal contact situations between the wheel and switch rail and worsens the stress state of the switch rail.

  16. Dynamics modeling of a semi-submersible autonomous underwater vehicle with a towfish towed by a cable

    Directory of Open Access Journals (Sweden)

    Jinmo Park

    2015-03-01

    Full Text Available In this paper, we employ a dynamics modeling method for investigating a multi-body dynamics system of semi-submersible autonomous underwater vehicles consisting of a towing vehicle operated near the water surface, a tow cable, and a towfish. The towfish, which is towed by a marine cable for the purposes of exploration or mine hunting, is modeled with a Six-Degree-of-Freedom (6-DOF equation of motion that reflects its hydrodynamics characteristics. The towing cable, which can experience large displacements and deformations, is modeled using an absolute nodal coordinate formulation. To reflect the hydrodynamic characteristics of the cable during motion, the hydrodynamic force due to added mass and the drag force are imposed. To verify the completeness of the modeling, a few simple numerical simulations were conducted, and the results confirm the physical plausibility of the model.

  17. Comparative Study of Dynamic Programming and Pontryagin’s Minimum Principle on Energy Management for a Parallel Hybrid Electric Vehicle

    Directory of Open Access Journals (Sweden)

    Huei Peng

    2013-04-01

    Full Text Available This paper compares two optimal energy management methods for parallel hybrid electric vehicles using an Automatic Manual Transmission (AMT. A control-oriented model of the powertrain and vehicle dynamics is built first. The energy management is formulated as a typical optimal control problem to trade off the fuel consumption and gear shifting frequency under admissible constraints. The Dynamic Programming (DP and Pontryagin’s Minimum Principle (PMP are applied to obtain the optimal solutions. Tuning with the appropriate co-states, the PMP solution is found to be very close to that from DP. The solution for the gear shifting in PMP has an algebraic expression associated with the vehicular velocity and can be implemented more efficiently in the control algorithm. The computation time of PMP is significantly less than DP.

  18. Dynamics modeling of a semi-submersible autonomous underwater vehicle with a towfish towed by a cable

    Science.gov (United States)

    Park, Jinmo; Kim, Nakwan

    2015-06-01

    In this paper, we employ a dynamics modeling method for investigating a multi-body dynamics system of semi-submersible autonomous underwater vehicles consisting of a towing vehicle operated near the water surface, a tow cable, and a towfish. The towfish, which is towed by a marine cable for the purposes of exploration or mine hunting, is modeled with a Six-Degree-of-Freedom (6-DOF) equation of motion that reflects its hydrodynamics characteristics. The towing cable, which can experience large displacements and deformations, is modeled using an absolute nodal coordinate formulation. To reflect the hydrodynamic characteristics of the cable during motion, the hydrodynamic force due to added mass and the drag force are imposed. To verify the completeness of the modeling, a few simple numerical simulations were conducted, and the results confirm the physical plausibility of the model.

  19. Research of Charging(Discharging Orderly and Optimizing Load Curve for Electric Vehicles Based on Dynamic Electric Price and V2G

    Directory of Open Access Journals (Sweden)

    Yang Shuai

    2016-01-01

    Full Text Available Firstly, using the Monte Carlo method and simulation analysis, this paper builds models for the behaviour of electric vehicles, the conventional charging model and the fast charging model. Secondly, this paper studies the impact that the number of electric vehicles which get access to power grid has on the daily load curve. Then, the paper put forwards a dynamic pricing mechanism of electricity, and studies how this dynamic pricing mechanism guides the electric vehicles to charge orderly. Last but not the least, the paper presents a V2G mechanism. Under this mechanism, electric vehicles can charge orderly and take part in the peak shaving. Research finds that massive electric vehicles’ access to the power grid will increase the peak-valley difference of daily load curve. Dynamic pricing mechanism and V2G mechanism can effectively lead the electric vehicles to take part in peak-shaving, and optimize the daily load curve.

  20. Dynamic programming algorithm for the vehicle routing problem with time windows and EC social legislation

    NARCIS (Netherlands)

    Kok, A. Leendert; Meyer, C. Manuel; Kopfer, Herbert; Schutten, J. Marco J.

    2009-01-01

    In practice, apart from the problem of vehicle routing, schedulers also face the problem of nding feasible driver schedules complying with complex restrictions on drivers' driving and working hours. To address this complex interdependent problem of vehicle routing and break scheduling, we propose a

  1. A dynamic programming heuristic for the vehicle routing problem with time windows and EC social legislation

    NARCIS (Netherlands)

    Kok, A. Leendert; Meyer, C. Manuel; Kopfer, Herbert; Schutten, J. Marco J.

    2009-01-01

    In practice, apart from the problem of vehicle routing, schedulers also face the problem of finding feasible driver schedules complying with complex restrictions on drivers' driving and working hours. To address this complex interdependent problem of vehicle routing and break scheduling, we propose

  2. Rigid-Flexible Coupling Dynamic Analysis of Sub-Launched Vehicle During the Vertical Tube-Exit Stage

    Institute of Scientific and Technical Information of China (English)

    Weiyao Zhang; Jingbo Gao; Cong Wang

    2015-01-01

    During the launching stage,hydrodynamic pressure and adapters’ reaction loads can influence the vehicle’ s rigid motion as well as cause its structural vibration,which is a typical rigid⁃flexible coupling dynamic problem. This paper presents a 2⁃D rigid⁃flexible coupling model to calculate the vehicle’ s dynamic responses in that period.The vehicle was equivalent to a flexure beam with axial deformation. Hybrid coordinate and modal superposition methods were used to describe its large rigid displacement and small deformation. By the second Lagrange equation, the vehicle centroid’ s displacements, rotational angle and modal coordinates were chosen as generalized coordinates and then the vehicle ’ s rigid⁃flexible coupling dynamic equations were obtained. By numerical simulation,the results of vehicle’s motion parameters and transverse internal loads were acquired.The calculation results showed that differences of the vehicle’ s motion parameters between the rigid⁃flexible coupling model and the rigid body assumption are noticeable and the peak magnitude of the vehicle’ s transverse internal loads in the rigid⁃flexible coupling model is higher remarkably than that in the rigid body assumption.

  3. Considering the dynamic refueling behavior in locating electric vehicle charging stations

    Science.gov (United States)

    Liu, K.; Sun, X. H.

    2014-11-01

    Electric vehicles (EVs) will certainly play an important role in addressing the energy and environmental challenges at current situation. However, location problem of EV charging stations was realized as one of the key issues of EVs launching strategy. While for the case of locating EV charging stations, more influence factors and constraints need to be considered since the EVs have some special attributes. The minimum requested charging time for EVs is usually more than 30minutes, therefore the possible delay time due to waiting or looking for an available station is one of the most important influence factors. In addition, the intention to purchase and use of EVs that also affects the location of EV charging stations is distributed unevenly among regions and should be considered when modelling. Unfortunately, these kinds of time-spatial constraints were always ignored in previous models. Based on the related research of refuelling behaviours and refuelling demands, this paper developed a new concept with dual objectives of minimum waiting time and maximum service accessibility for locating EV charging stations - named as Time-Spatial Location Model (TSLM). The proposed model and the traditional flow-capturing location model are applied on an example network respectively and the results are compared. Results demonstrate that time constraint has great effects on the location of EV charging stations. The proposed model has some obvious advantages and will help energy providers to make a viable plan for the network of EV charging stations.

  4. Simulation and experimental validation of vehicle dynamic characteristics for displacement-sensitive shock absorber using fluid-flow modelling

    Science.gov (United States)

    Lee, Choon-Tae; Moon, Byung-Young

    2006-02-01

    In this study, a new mathematical dynamic model of shock absorber is proposed to predict the dynamic characteristics of an automotive system. The performance of shock absorber is directly related to the car behaviours and performance, both for handling and ride comfort. Damping characteristics of automotive can be analysed by considering the performance of displacement-sensitive shock absorber (DSSA) for the ride comfort. The proposed model of the DSSA is considered as two modes of damping force (i.e. soft and hard) according to the position of piston. For the simulation validation of vehicle-dynamic characteristics, the DSSA is mathematically modelled by considering the fluid flow in chamber and valve in accordance with the hard, transient and soft zone. And the vehicle dynamic characteristic of the DSSA is analysed using quarter car model. To show the effectiveness of the proposed damper, the analysed results of damping characteristics were compared with the experimental results, which showed similar behaviour with the corresponding experimental one. The simulation results of frequency response are compared with the ones of passive shock absorber. From the simulation results of the DSSA, it can be concluded that the ride comfort of the DSSA increased at the low-amplitude road condition and the driving safety was increased partially at the high-amplitude road condition. The results reported herein will provide a better understanding of the shock absorber. Moreover, it is believed that those properties of the results can be utilised in the dynamic design of the automotive system.

  5. High-Resolution Monitoring of Himalayan Glacier Dynamics Using Unmanned Aerial Vehicles

    Science.gov (United States)

    Immerzeel, W.; Kraaijenbrink, P. D. A.; Shea, J.; Shrestha, A. B.; Pellicciotti, F.; Bierkens, M. F.; de Jong, S. M.

    2014-12-01

    Himalayan glacier tongues are commonly debris covered and play an important role in modulating the glacier response to climate . However, they remain relatively unstudied because of the inaccessibility of the terrain and the difficulties in field work caused by the thick debris mantles. Observations of debris-covered glaciers are therefore limited to point locations and airborne remote sensing may bridge the gap between scarce, point field observations and coarse resolution space-borne remote sensing. In this study we deploy an Unmanned Airborne Vehicle (UAV) on two debris covered glaciers in the Nepalese Himalayas: the Lirung and Langtang glacier during four field campaigns in 2013 and 2014. Based on stereo-imaging and the structure for motion algorithm we derive highly detailed ortho-mosaics and digital elevation models (DEMs), which we geometrically correct using differential GPS observations collected in the field. Based on DEM differencing and manual feature tracking we derive the mass loss and the surface velocity of the glacier at a high spatial resolution and accuracy. We also assess spatiotemporal changes in supra-glacial lakes and ice cliffs based on the imagery. On average, mass loss is limited and the surface velocity is very small. However, the spatial variability of melt rates is very high, and ice cliffs and supra-glacial ponds show mass losses that can be an order of magnitude higher than the average. We suggest that future research should focus on the interaction between supra-glacial ponds, ice cliffs and englacial hydrology to further understand the dynamics of debris-covered glaciers. Finally, we conclude that UAV deployment has large potential in glaciology and it represents a substantial advancement over methods currently applied in studying glacier surface features.

  6. Dynamic Digital Maps as Vehicles for Distributing Digital Geologic Maps and Embedded Analytical Data and Multimedia

    Science.gov (United States)

    Condit, C. D.; Mninch, M.

    2012-12-01

    The Dynamic Digital Map (DDM) is an ideal vehicle for the professional geologist to use to describe the geologic setting of key sites to the public in a format that integrates and presents maps and associated analytical data and multimedia without the need for an ArcGIS interface. Maps with field trip guide stops that include photographs, movies and figures and animations, showing, for example, how the features seen in the field formed, or how data might be best visualized in "time-frame" sequences are ideally included in DDMs. DDMs distribute geologic maps, images, movies, analytical data, and text such as field guides, in an integrated cross-platform, web enabled format that are intuitive to use, easily and quickly searchable, and require no additional proprietary software to operate. Maps, photos, movies and animations are stored outside the program, which acts as an organizational framework and index to present these data. Once created, the DDM can be downloaded from the web site hosting it in the flavor matching the user's operating system (e.g. Linux, Windows and Macintosh) as zip, dmg or tar files (and soon as iOS and Android tablet apps). When decompressed, the DDM can then access its associated data directly from that site with no browser needed. Alternatively, the entire package can be distributed and used from CD, DVD, or flash-memory storage. The intent of this presentation is to introduce the variety of geology that can be accessed from the over 25 DDMs created to date, concentrating on the DDM of the Springerville Volcanic Field. We will highlight selected features of some of them, introduce a simplified interface to the original DDM (that we renamed DDMC for Classic) and give a brief look at a the recently (2010-2011) completed geologic maps of the Springerville Volcanic field to see examples of each of the features discussed above, and a display of the integrated analytical data set. We will also highlight the differences between the classic or

  7. Real-Time Monitoring of Non-linear Suicidal Dynamics: Methodology and a Demonstrative Case Report.

    Science.gov (United States)

    Fartacek, Clemens; Schiepek, Günter; Kunrath, Sabine; Fartacek, Reinhold; Plöderl, Martin

    2016-01-01

    In recent years, a number of different authors have stressed the usefulness of non-linear dynamic systems approach in suicide research and suicide prevention. This approach applies specific methods of time series analysis and, consequently, it requires a continuous and fine-meshed assessment of the processes under consideration. The technical means for this kind of process assessment and process analysis are now available. This paper outlines how suicidal dynamics can be monitored in high-risk patients by an Internet-based application for continuous self-assessment with integrated tools of non-linear time series analysis: the Synergetic Navigation System. This procedure is illustrated by data from a patient who attempted suicide at the end of a 90-day monitoring period. Additionally, future research topics and clinical applications of a non-linear dynamic systems approach in suicidology are discussed.

  8. Autonomous terrain characterization and modelling for dynamic control of unmanned vehicles

    Science.gov (United States)

    Talukder, A.; Manduchi, R.; Castano, R.; Owens, K.; Matthies, L.; Castano, A.; Hogg, R.

    2002-01-01

    This end-to-end obstacle negotiation system is envisioned to be useful in optimized path planning and vehicle navigation in terrain conditions cluttered with vegetation, bushes, rocks, etc. Results on natural terrain with various natural materials are presented.

  9. Autonomous terrain characterization and modelling for dynamic control of unmanned vehicles

    Science.gov (United States)

    Talukder, A.; Manduchi, R.; Castano, R.; Owens, K.; Matthies, L.; Castano, A.; Hogg, R.

    2002-01-01

    This end-to-end obstacle negotiation system is envisioned to be useful in optimized path planning and vehicle navigation in terrain conditions cluttered with vegetation, bushes, rocks, etc. Results on natural terrain with various natural materials are presented.

  10. Program description for the program Demonstration program for electric vehicles 2011-2015; Programbeskrivning foer programmet Demonstrationsprogram foer elfordon 2011-2015

    Energy Technology Data Exchange (ETDEWEB)

    2011-04-15

    The program's efforts aim at, firstly, from a user perspective identify and possibly eliminate barriers for large-scale introduction of electric vehicles on the Swedish market. Through various research activities based in the real environment experience may be drawn from both vehicle use and different types of behavior. Infrastructure tests on a sufficient scale give the combined effect of real-life test environments for the combination of vehicles and charging environments as well as a base for experiences of softer issues around electric vehicles. Precisely these behavioral experiences are difficult to reach via the related but more technically focused programs such as, FFI (Vehicle strategic research and innovation) and Energy efficient road vehicles. Several systems for electrification of vehicles exist today, and further initiatives for solutions are on the way. It is therefore very important to examine which systems give the highest total energy efficiency. It is also relevant for these different systems in a real environment to explore the potentials and difficulties that may arise in larger implementations

  11. Traceable calibration and demonstration of a portable dynamic force transfer standard

    Science.gov (United States)

    Vlajic, Nicholas; Chijioke, Ako

    2017-08-01

    In general, the dynamic sensitivity of a force transducer depends upon the mechanical system in which it is used. This dependence serves as motivation to develop a dynamic force transfer standard, which can be used to calibrate an application transducer in situ. In this work, we SI-traceably calibrate a hand-held force transducer, namely an impact hammer, by using a mass suspended from a thin line which is cut to produce a known dynamic force in the form of a step function. We show that this instrument is a promising candidate as a transfer standard, since its dynamic response has small variance between different users. This calibrated transfer standard is then used to calibrate a secondary force transducer in an example application setting. The combined standard uncertainty (k  =  2) in the calibration of the transfer standard was determined to be 2.1% or less, up to a bandwidth of 5 kHz. The combined standard uncertainty (k  =  2) in the performed transfer calibration was less than 4%, up to 3 kHz. An advantage of the transfer calibration framework presented here, is that the transfer standard can be used to transfer SI-traceable calibrations without the use of any SI-traceable voltage metrology instrumentation.

  12. Dynamic Radioactive Source for Evaluating and Demonstrating Time-dependent Performance of Continuous Air Monitors.

    Science.gov (United States)

    McLean, Thomas D; Moore, Murray E; Justus, Alan L; Hudston, Jonathan A; Barbé, Benoît

    2016-11-01

    Evaluation of continuous air monitors in the presence of a plutonium aerosol is time intensive, expensive, and requires a specialized facility. The Radiation Protection Services Group at Los Alamos National Laboratory has designed a Dynamic Radioactive Source, intended to replace plutonium aerosol challenge testing. The Dynamic Radioactive Source is small enough to be inserted into the sampler filter chamber of a typical continuous air monitor. Time-dependent radioactivity is introduced from electroplated sources for real-time testing of a continuous air monitor where a mechanical wristwatch motor rotates a mask above an alpha-emitting electroplated disk source. The mask is attached to the watch's minute hand, and as it rotates, more of the underlying source is revealed. The measured alpha activity increases with time, simulating the arrival of airborne radioactive particulates at the air sampler inlet. The Dynamic Radioactive Source allows the temporal behavior of puff and chronic release conditions to be mimicked without the need for radioactive aerosols. The new system is configurable to different continuous air monitor designs and provides an in-house testing capability (benchtop compatible). It is a repeatable and reusable system and does not contaminate the tested air monitor. Test benefits include direct user control, realistic (plutonium) aerosol spectra, and iterative development of continuous air monitor alarm algorithms. Data obtained using the Dynamic Radioactive Source has been used to elucidate alarm algorithms and to compare the response time of two commercial continuous air monitors.

  13. 求解动态车辆调度问题的混合禁忌搜索算法%HYBRID TABU SEARCH ALGORITHM FOR SOLVING DYNAMIC VEHICLE SCHEDULING

    Institute of Scientific and Technical Information of China (English)

    袁建清

    2012-01-01

    On the basis of analysing dynamic vehicle scheduling problem with time windows, a dynamic vehicle scheduling mathematical model based on time axis is proposed by introducing the concept of virtual point and time axis. A hybrid tabu algorithm based on C-W algorithm and tabu algorithm is designed to solve the problem, which uses the candidate solutions constructed with dynamic method and the dynamic tabu length selection strategy to improve convergence speed. Then the test instances are provided to demonstrate that the hybrid tabu search algorithm is effective and feasible in solving dynamic vehicle scheduling problem.%对带时间窗的动态车辆调度问题进行分析,引入虚拟点和时间轴概念,建立基于时间轴的动态车辆调度模型,并提出基于C-W节约法和禁忌搜索的混合禁忌搜索算法进行求解.算法中使用动态方法构造候选解和动态禁忌长度的选取策略来提高算法的收敛速度,最后通过测试实例验证了该混合算法解决动态车辆调度问题的有效性和可行性.

  14. The Effects of Powertrain Mechanical Response on the Dynamics and String Stability of a Platoon of Adaptive Cruise Control Vehicles

    CERN Document Server

    Davis, L C

    2013-01-01

    The dynamics of a platoon of adaptive cruise control vehicles is analyzed for a general mechanical response of the vehicle's power-train. Effects of acceleration-feedback control that were not previously studied are found. For small acceleration-feedback gain, which produces marginally string-stable behavior, the reduction of a disturbance (with increasing car number n) is found to be faster than for the maximum allowable gain. The asymptotic magnitude of a disturbance is shown to fall off as erf(ct./sq. rt. n) when n goes to infinity. For gain approaching the lower limit of stability, oscillations in acceleration associated with a secondary maximum in the transfer function (as a function of frequency) can occur. A frequency-dependent gain that reduces the secondary maximum, but does not affect the transfer function near zero frequency, is proposed. Performance is thereby improved by elimination of the undesirable oscillations while the rapid disturbance reduction is retained.

  15. Mutation Ant Colony Algorithm of Milk-Run Vehicle Routing Problem with Fastest Completion Time Based on Dynamic Optimization

    Directory of Open Access Journals (Sweden)

    Jianhua Ma

    2013-01-01

    Full Text Available The objective of vehicle routing problem is usually to minimize the total traveling distance or cost. But in practice, there are a lot of problems needed to minimize the fastest completion time. The milk-run vehicle routing problem (MRVRP is widely used in milk-run distribution. The mutation ACO is given to solve MRVRP with fastest completion time in this paper. The milk-run VRP with fastest completion time is introduced first, and then the customer division method based on dynamic optimization and split algorithm is given to transform this problem into finding the optimal customer order. At last the mutation ACO is given and the numerical examples verify the effectiveness of the algorithm.

  16. Dynamic Modeling and Control Strategy Optimization for a Hybrid Electric Tracked Vehicle

    Directory of Open Access Journals (Sweden)

    Hong Wang

    2015-01-01

    Full Text Available A new hybrid electric tracked bulldozer composed of an engine generator, two driving motors, and an ultracapacitor is put forward, which can provide high efficiencies and less fuel consumption comparing with traditional ones. This paper first presents the terramechanics of this hybrid electric tracked bulldozer. The driving dynamics for this tracked bulldozer is then analyzed. After that, based on analyzing the working characteristics of the engine, generator, and driving motors, the power train system model and control strategy optimization is established by using MATLAB/Simulink and OPTIMUS software. Simulation is performed under a representative working condition, and the results demonstrate that fuel economy of the HETV can be significantly improved.

  17. Dynamic modeling of wave driven unmanned surface vehicle in longitudinal profile based on D-H approach

    Institute of Scientific and Technical Information of China (English)

    田宝强; 俞建成; 张艾群

    2015-01-01

    Wave driven unmanned surface vehicle (WUSV) is a new concept ocean robot drived by wave energy and solar energy, and it is very suitable for the vast ocean observations with incomparable endurance. Its dynamic modeling is very important because it is the theoretical foundation for further study in the WUSV motion control and efficiency analysis. In this work, the multibody system of WUSV was described based on D-H approach. Then, the driving principle was analyzed and the dynamic model of WUSV in longitudinal profile is established by Lagrangian mechanics. Finally, the motion simulation of WUSV and comparative analysis are completed by setting different inputs of sea state. Simulation results show that the WUSV dynamic model can correctly reflect the WUSV longitudinal motion process, and the results are consistent with the wave theory.

  18. The human functional brain network demonstrates structural and dynamical resilience to targeted attack.

    Directory of Open Access Journals (Sweden)

    Karen E Joyce

    Full Text Available In recent years, the field of network science has enabled researchers to represent the highly complex interactions in the brain in an approachable yet quantitative manner. One exciting finding since the advent of brain network research was that the brain network can withstand extensive damage, even to highly connected regions. However, these highly connected nodes may not be the most critical regions of the brain network, and it is unclear how the network dynamics are impacted by removal of these key nodes. This work seeks to further investigate the resilience of the human functional brain network. Network attack experiments were conducted on voxel-wise functional brain networks and region-of-interest (ROI networks of 5 healthy volunteers. Networks were attacked at key nodes using several criteria for assessing node importance, and the impact on network structure and dynamics was evaluated. The findings presented here echo previous findings that the functional human brain network is highly resilient to targeted attacks, both in terms of network structure and dynamics.

  19. The human functional brain network demonstrates structural and dynamical resilience to targeted attack.

    Science.gov (United States)

    Joyce, Karen E; Hayasaka, Satoru; Laurienti, Paul J

    2013-01-01

    In recent years, the field of network science has enabled researchers to represent the highly complex interactions in the brain in an approachable yet quantitative manner. One exciting finding since the advent of brain network research was that the brain network can withstand extensive damage, even to highly connected regions. However, these highly connected nodes may not be the most critical regions of the brain network, and it is unclear how the network dynamics are impacted by removal of these key nodes. This work seeks to further investigate the resilience of the human functional brain network. Network attack experiments were conducted on voxel-wise functional brain networks and region-of-interest (ROI) networks of 5 healthy volunteers. Networks were attacked at key nodes using several criteria for assessing node importance, and the impact on network structure and dynamics was evaluated. The findings presented here echo previous findings that the functional human brain network is highly resilient to targeted attacks, both in terms of network structure and dynamics.

  20. Dynamic Modeling and Validation of a Biomass Hydrothermal Pretreatment Process - A Demonstration Scale Study

    DEFF Research Database (Denmark)

    Prunescu, Remus Mihail; Blanke, Mogens; Jakobsen, Jon Geest

    2015-01-01

    Hydrothermal pretreatment of lignocellulosic biomass is a cost effective technology for second generation biorefineries. The process occurs in large horizontal and pressurized thermal reactors where the biomatrix is opened under the action of steam pressure and temperature to expose cellulose...... for the enzymatic hydrolysis process. Several by-products are also formed, which disturb and act as inhibitors downstream. The objective of this study is to formulate and validate a large scale hydrothermal pretreatment dynamic model based on mass and energy balances, together with a complex conversion mechanism...... of the process, outlining the value of the model for simulation, control design, and optimization for full-scale applications....

  1. 突发事件下车辆路径问题的动态规划算法%Dynamic Programming Algorithm of Vehicle Routing Problems under Emergencies

    Institute of Scientific and Technical Information of China (English)

    欧微; 焦丽萍

    2011-01-01

    突发事件下的车辆运输具有紧迫性、动态性和随机不确定性等特点.本文研究了突发事件下动态车辆路径问题的数学模型,构建了一种基于混沌优化的动态规划算法,为此通过路径计算和动态规划两个模块来实现车辆路径的动态规划.为实现从混沌运动空间向问题可行解空间的有效映射,提出了相应的编码方法和操作算子.最后进行仿真,通过对静态环境、道路受损和道路拥塞三种情况的分析,验证了实时修订路经的有效性和实用性,为突发事件提供参考.%The vehicle transportation under emergencies is a kind of emergent, dynamic and random problems. The mathematics model of Dynamic Vehicle Routing Problems (DVRP) under emergencies is proposed, and an ap-proach solving DVRP based on chaos optimization is formulated, in which a route computing module and a dynamic programming module are introduced, and the corresponding coding method and operators are proposed to mapping the chaos space to feasible solution space. Finally, three cases of initial - state, road - damaged and road - congested are analyzed separately to demonstrate the necessary of real - time route adjusting and the efficiency of the proposed algorithm by computer simulations.

  2. The dynamic behaviour of the floor of a surrogate vehicle under explosive blast loading

    CSIR Research Space (South Africa)

    Newell, N

    2016-01-01

    Full Text Available from a landmine detonation under a light armoured or logistic military vehicle. The rig is designed such that an anthropometric test device (ATD) can be seated with the feet resting on the bottom plate (North Atlantic Treaty Organisation HFM-090 TG 25...-in-air blast load (Figure 1). The blast capsule’s loading surface is a rectangular flat armoured steel plate (Weldox 700 E, SSAB, Stockholm, Sweden), 20 × 2500 × 2000 mm in dimensions, which is used as the vehicle-floor surrogate. The plate was bolted under a...

  3. Using a Virtual Class to Demonstrate Computer-Mediated Group Dynamics Concepts

    Science.gov (United States)

    Franz, Timothy M.; Vicker, Lauren A.

    2010-01-01

    We report about an active learning demonstration designed to use a virtual class to present computer-mediated group communication course concepts to show that students can learn about these concepts in a virtual class. We designated 1 class period as a virtual rather than face-to-face class, when class members "attended" virtually using…

  4. High-resolution dynamic angiography using flat-panel volume CT: feasibility demonstration for neuro and lower limb vascular applications

    Energy Technology Data Exchange (ETDEWEB)

    Mehndiratta, Amit [Massachusetts General Hospital, Department of Radiology, Harvard Medical School, Boston, MA (United States); University of Oxford, Institute of Biomedical Engineering and Keble College, Oxford (United Kingdom); Indian Institute of Technology Delhi and All India Institute of Medical Science, Centre for Biomedical Engineering, New Delhi (India); Rabinov, James D. [Massachusetts General Hospital, Interventional Neuroradiology, Harvard Medical School, Boston, MA (United States); Grasruck, Michael [Siemens Medical Solutions, Forchheim (Germany); Liao, Eric C. [Massachusetts General Hospital, Department of Plastic and Reconstructive Surgery and Center for Regenerative Medicine, Harvard Medical School, Boston, MA (United States); Crandell, David [Spaulding Rehabilitation Hospital, Department of Physical Medicine and Rehabilitation, Harvard Medical School, Charlestown, MA (United States); Gupta, Rajiv [Massachusetts General Hospital, Department of Radiology, Harvard Medical School, Boston, MA (United States)

    2015-07-15

    This paper evaluates a prototype flat-panel volume CT (fpVCT) for dynamic in vivo imaging in a variety of neurovascular and lower limb applications. Dynamic CTA was performed on 12 patients (neuro = 8, lower limb = 4) using an fpVCT with 120 kVp, 50 mA, rotation time varying from 8 to 19 s, and field of view of 25 x 25 x 18 cm{sup 3}. Four-dimensional data sets (i.e. 3D images over time) were reconstructed and reviewed. Dynamic CTA demonstrated sufficient spatio-temporal resolution to elucidate first-pass and recirculation dynamics of contrast bolus through neurovasclar pathologies and phasic blood flow though lower-limb vasculature and grafts. The high spatial resolution of fpVCT resulted in reduced partial volume and metal beam-hardening artefacts. This facilitated assessment of vascular lumen in the presence of calcified plaque and evaluation of fractures, especially in the presence of fixation hardware. Evaluation of arteriovenous malformation using dynamic fpVCT angiography was of limited utility. Dynamic CTA using fpVCT can visualize time-varying phenomena in neuro and lower limb vascular applications and has sufficient diagnostic imaging quality to evaluate a number of pathologies affecting these regions. (orig.)

  5. Dynamic Simulation, Sensitivity and Uncertainty Analysis of a Demonstration Scale Lignocellulosic Enzymatic Hydrolysis Process

    DEFF Research Database (Denmark)

    Prunescu, Remus Mihail; Sin, Gürkan

    2014-01-01

    , accounting a large number of parameters. The sensitivity analysis of model predictions with respect to model parameters is quantified by the delta mean square measure. By ranking the delta mean square, a reduced subset of parameters is found helping to identify the bottleneck of the model. The uncertainty...... to be affected by non-zero mean noise because they are determined by a Near Infrared (NIR) instrument. LHS is performed on 2 parameters: the probability of the mean value and the probability of the standard deviation for each measurement. The Monte Carlo outputs are then analyzed by linear regression......This study presents the uncertainty and sensitivity analysis of a lignocellulosic enzymatic hydrolysis model considering both model and feed parameters as sources of uncertainty. The dynamic model is parametrized for accommodating various types of biomass, and different enzymatic complexes...

  6. A closed-loop dynamic simulation-based design method for articulated heavy vehicles with active trailer steering systems

    Science.gov (United States)

    Manjurul Islam, Md.; Ding, Xuejun; He, Yuping

    2012-05-01

    This paper presents a closed-loop dynamic simulation-based design method for articulated heavy vehicles (AHVs) with active trailer steering (ATS) systems. AHVs have poor manoeuvrability at low speeds and exhibit low lateral stability at high speeds. From the design point of view, there exists a trade-off relationship between AHVs' manoeuvrability and stability. For example, fewer articulation points and longer wheelbases will improve high-speed lateral stability, but they will degrade low-speed manoeuvrability. To tackle this conflicting design problem, a systematic method is proposed for the design of AHVs with ATS systems. In order to evaluate vehicle performance measures under a well-defined testing manoeuvre, a driver model is introduced and it 'drivers' the vehicle model to follow a prescribed route at a given speed. Considering the interactions between the mechanical trailer and the ATS system, the proposed design method simultaneously optimises the active design variables of the controllers and passive design variables of the trailer in a single design loop (SDL). Through the design optimisation of an ATS system for an AHV with a truck and a drawbar trailer combination, this SDL method is compared against a published two design loop method. The benchmark investigation shows that the former can determine better trade-off design solutions than those derived by the latter. This SDL method provides an effective approach to automatically implement the design synthesis of AHVs with ATS systems.

  7. Experimental verification of a thermal equivalent circuit dynamic model on an extended range electric vehicle battery pack

    Science.gov (United States)

    Ramotar, Lokendra; Rohrauer, Greg L.; Filion, Ryan; MacDonald, Kathryn

    2017-03-01

    The development of a dynamic thermal battery model for hybrid and electric vehicles is realized. A thermal equivalent circuit model is created which aims to capture and understand the heat propagation from the cells through the entire pack and to the environment using a production vehicle battery pack for model validation. The inclusion of production hardware and the liquid battery thermal management system components into the model considers physical and geometric properties to calculate thermal resistances of components (conduction, convection and radiation) along with their associated heat capacity. Various heat sources/sinks comprise the remaining model elements. Analog equivalent circuit simulations using PSpice are compared to experimental results to validate internal temperature nodes and heat rates measured through various elements, which are then employed to refine the model further. Agreement with experimental results indicates the proposed method allows for a comprehensive real-time battery pack analysis at little computational expense when compared to other types of computer based simulations. Elevated road and ambient conditions in Mesa, Arizona are simulated on a parked vehicle with varying quiescent cooling rates to examine the effect on the diurnal battery temperature for longer term static exposure. A typical daily driving schedule is also simulated and examined.

  8. Longitudinal dynamics of motor vehicles. Traffic system motor vehicle, power demand and energy demand, power train. Book to the course of lectures 'Motor car engineering'. 14. ed.; Laengsdynamik von Kraftfahrzeugen. Verkehrssystem Kraftfahrzeug, Leistungs- und Energiebedarf, Antriebstrang, Fahrzeugdynamik. Vorlesungsumdruck Fahrzeugtechnik I

    Energy Technology Data Exchange (ETDEWEB)

    Wallentowitz, Henning; Gies, Stefan

    2008-07-01

    The author of the contribution under consideration reports on the longitudinal dynamics of motor vehicles. The longitudinal dynamics describe the procedures and components affecting the movement of a vehicle in its longitudinal direction. The introducing chapter describes the traffic system motor vehicle as well as the economic aspects of motor vehicles. The following chapters of this contribution are concerned to the following topics: (a) Power demand and energy demand with consideration of the wheel resistance, air resistance, upward gradient resistance and the acceleration resistance; (b) Power train; (c) Vehicle dynamics under consideration of the road performance, fuel consumption, propulsion principles and driving borders.

  9. Real-Time Dynamic Model Learning and Adaptation for Underwater Vehicles

    Science.gov (United States)

    2013-09-01

    controllability and observability. A method for determining both the controllability and observability of a system is presented by Ogata [18...distribution is unlimited 12b. DISTRIBUTION CODE A 13. ABSTRACT (maximum 200 words) Precision control of unmanned underwater vehicles (UUVs...Department of Mechanical and Aerospace Engineering iii THIS PAGE INTENTIONALLY LEFT BLANK iv ABSTRACT Precision control of unmanned

  10. Constrained Control Design for Dynamic Positioning of Marine Vehicles with Control Allocation

    Directory of Open Access Journals (Sweden)

    Tristan Perez

    2009-04-01

    Full Text Available In this paper, we address the control design problem of positioning of over-actuated marine vehicles with control allocation. The proposed design is based on a combined position and velocity loops in a multi-variable anti-windup implementation together with a control allocation mapping. The vehicle modelling is considered with appropriate simplifications related to low-speed manoeuvring hydrodynamics and vehicle symmetry. The control design is considered together with a control allocation mapping. We derive analytical tuning rules based on requirements of closed-loop stability and performance. The anti- windup implementation of the controller is obtained by mapping the actuator-force constraint set into a constraint set for the generalized forces. This approach ensures that actuation capacity is not violated by constraining the generalized control forces; thus, the control allocation is simplified since it can be formulated as an unconstrained problem. The mapping can also be modified on-line based on actuator availability to provide actuator-failure accommodation. We provide a proof of the closed-loop stability and illustrate the performance using simulation scenarios for an open-frame underwater vehicle.

  11. A dynamic programming heuristic for vehicle routing with time-dependent travel times and required breaks

    NARCIS (Netherlands)

    Kok, A.L.; Hans, E.W.; Schutten, J.M.J.; Zijm, W.H.M.

    2010-01-01

    For the intensively studied vehicle routing problem (VRP), two real-life restrictions have received only minor attention in the VRP-literature: traffic congestion and driving hours regulations. Traffic congestion causes late arrivals at customers and long travel times resulting in large transport co

  12. Multi-Mission Earth Vehicle Subsonic Dynamic Stability Testing and Analyses

    Science.gov (United States)

    Glaab, Louis J.; Fremaux, C. Michael

    2013-01-01

    Multi-Mission Earth Entry Vehicles (MMEEVs) are blunt-body vehicles designed with the purpose of transporting payloads from outer space to the surface of the Earth. To achieve high-reliability and minimum weight, MMEEVs avoid use of limited-reliability systems, such as parachutes, retro-rockets, and reaction control systems and rely on the natural aerodynamic stability of the vehicle throughout the Entry, Descent, and Landing (EDL) phase of flight. The Multi-Mission Systems Analysis for Planetary Entry (M-SAPE) parametric design tool is used to facilitate the design of MMEEVs for an array of missions and develop and visualize the trade space. Testing in NASA Langley?s Vertical Spin Tunnel (VST) was conducted to significantly improve M-SAPE?s subsonic aerodynamic models. Vehicle size and shape can be driven by entry flight path angle and speed, thermal protection system performance, terminal velocity limitations, payload mass and density, among other design parameters. The objectives of the VST testing were to define usable subsonic center of gravity limits, and aerodynamic parameters for 6-degree-of-freedom (6-DOF) simulations, for a range of MMEEV designs. The range of MMEEVs tested was from 1.8m down to 1.2m diameter. A backshell extender provided the ability to test a design with a much larger payload for the 1.2m MMEEV.

  13. A dynamic programming heuristic for vehicle routing with time-dependent travel times and required breaks.

    NARCIS (Netherlands)

    Kok, A.L.; Hans, Elias W.; Schutten, Johannes M.J.; Zijm, Willem H.M.

    2010-01-01

    For the intensively studied vehicle routing problem (VRP), two real-life restrictions have received only minor attention in the VRP-literature: traffic congestion and driving hours regulations. Traffic congestion causes late arrivals at customers and long travel times resulting in large transport

  14. How do esters and dimethyl sulphide concentrations affect fruity aroma perception of red wine? Demonstration by dynamic sensory profile evaluation.

    Science.gov (United States)

    Lytra, Georgia; Tempere, Sophie; Marchand, Stéphanie; de Revel, Gilles; Barbe, Jean-Christophe

    2016-03-01

    Our study focused on variations in wine aroma perception and molecular composition during tasting over a period of 30min. In parallel, dynamic analytical and sensory methods were applied to study changes in the wines' molecular and aromatic evolution. Dynamic sensory profile evaluations clearly confirmed the evolution of the wine's fruity notes during sensory analysis, highlighting significant differences for red-berry and fresh fruit as well as black berry and jammy fruit, after 5 and 15min, respectively. Dynamic analytical methods revealed a decrease in ester and dimethyl sulphide (DMS) concentrations in the first few minutes. Sensory profiles of aromatic reconstitutions demonstrated that the aromatic modulation of fruity notes observed during wine tasting was explained by changes in ester and DMS concentrations. These results revealed that variations in concentrations of DMS and esters during wine tasting had a qualitative impact, by modulating fruity aromas in red wine.

  15. Method and system for detecting a failure or performance degradation in a dynamic system such as a flight vehicle

    Science.gov (United States)

    Miller, Robert H. (Inventor); Ribbens, William B. (Inventor)

    2003-01-01

    A method and system for detecting a failure or performance degradation in a dynamic system having sensors for measuring state variables and providing corresponding output signals in response to one or more system input signals are provided. The method includes calculating estimated gains of a filter and selecting an appropriate linear model for processing the output signals based on the input signals. The step of calculating utilizes one or more models of the dynamic system to obtain estimated signals. The method further includes calculating output error residuals based on the output signals and the estimated signals. The method also includes detecting one or more hypothesized failures or performance degradations of a component or subsystem of the dynamic system based on the error residuals. The step of calculating the estimated values is performed optimally with respect to one or more of: noise, uncertainty of parameters of the models and un-modeled dynamics of the dynamic system which may be a flight vehicle or financial market or modeled financial system.

  16. A Near-Hover Adaptive Attitude Control Strategy of a Ducted Fan Micro Aerial Vehicle with Actuator Dynamics

    Directory of Open Access Journals (Sweden)

    Shouzhao Sheng

    2015-09-01

    Full Text Available The aerodynamic parameters of ducted fan micro aerial vehicles (MAVs are difficult and expensive to precisely measure and are, therefore, not available in most cases. Furthermore, the actuator dynamics with risks of potentially destabilizing the overall system are important but often neglected consideration factors in the control system design of ducted fan MAVs. This paper presents a near-hover adaptive attitude control strategy of a prototype ducted fan MAV with actuator dynamics and without any prior information about the behavior of the MAV. The proposed strategy consists of an online parameter estimation algorithm and an adaptive gain scheduling algorithm, with the former accommodating parametric uncertainties, and the latter approximately eliminating the coupling among axes and guaranteeing the control quality of the MAV. The effectiveness of the proposed strategy is verified numerically and experimentally.

  17. A Dynamic Control Strategy for Hybrid Electric Vehicles Based on Parameter Optimization for Multiple Driving Cycles and Driving Pattern Recognition

    Directory of Open Access Journals (Sweden)

    Zhenzhen Lei

    2017-01-01

    Full Text Available The driving pattern has an important influence on the parameter optimization of the energy management strategy (EMS for hybrid electric vehicles (HEVs. A new algorithm using simulated annealing particle swarm optimization (SA-PSO is proposed for parameter optimization of both the power system and control strategy of HEVs based on multiple driving cycles in order to realize the minimum fuel consumption without impairing the dynamic performance. Furthermore, taking the unknown of the actual driving cycle into consideration, an optimization method of the dynamic EMS based on driving pattern recognition is proposed in this paper. The simulation verifications for the optimized EMS based on multiple driving cycles and driving pattern recognition are carried out using Matlab/Simulink platform. The results show that compared with the original EMS, the former strategy reduces the fuel consumption by 4.36% and the latter one reduces the fuel consumption by 11.68%. A road test on the prototype vehicle is conducted and the effectiveness of the proposed EMS is validated by the test data.

  18. Demonstrative potential of multitemporal satellite imagery in documenting urban dynamics: generalisation from the Bucharest city case

    Science.gov (United States)

    Aldea, Mihaela; Petrescu, Florian; Parlow, Eberhard; Iacoboaea, Cristina; Luca, Oana; Sercaianu, Mihai; Gaman, Florian

    2016-08-01

    The main objective of this paper is to demonstrate the potential of multitemporal satellite imagery to be processed and used in documenting urban changes that took place over time, with limited resources involved and taking advantage of the opportunity to be able to use the satellite imagery available as open data. The possibilities to analyse and compare the written literature regarding the chronological evolution of a city with the patterns of Land Use/Land Cover obtained from the processing of satellite remotely sensed images of the respective scenery were investigated based upon a case study of a selected city. The extent of the prospects of using remote sensing based methods and multitemporal satellite imagery is also expressed as a result of this investigation.

  19. Influence of Structural Flexibility on the Dynamic Precision of a Vehicle-Mounted Equipment System

    Science.gov (United States)

    2015-05-12

    complexity , computational time UNCLASSIFIED SAE INTERNATIONAL Craig-Bampton Method * R. R. Craig and M. C. C. Bampton, “Coupling of Substructures...Component Mode Synthesis (CMS) 11 5. Craig-Bampton CMS Method 12 6. Craig-Chang CMS Method 13 7. Flexible Vehicle...frequencies in response UNCLASSIFIED SAE INTERNATIONAL Component Mode Synthesis 11 • Component mode synthesis (CMS) is a technique that allows to

  20. Adaptive High Order Sliding Mode Controller Design for Hypersonic Vehicle with Flexible Body Dynamics

    OpenAIRE

    Bailing Tian; Wenru Fan; Qun Zong; Jie Wang; Fang Wang

    2013-01-01

    This paper describes the design of a nonlinear robust adaptive controller for a flexible hypersonic vehicle model which is nonlinear, multivariable, and unstable, and includes uncertain parameters. Firstly, a control-oriented model is derived for controller design. Then, the model analysis is conducted for this model via input-output (I/O) linearized technique. Secondly, the sliding mode manifold is designed based on the homogeneity theory. Then, the adaptive high order sliding mode controlle...

  1. Vehicle Dynamics Monitoring and Tracking System (VDMTS): Monitoring Mission Impacts in Support of Installation Land Management

    Science.gov (United States)

    2012-06-01

    performed using multiple vehicles at Fort Ri- ley , PTA, and Eglin AFB. The theoretical model results were compared with measured impact values. Additionally...Sample Conversions: $BB209 = -178.75°/s $ESOF2 = 0.806 g $H80BC = 0.094 gauss $J800D = 26.82 OC $S87FE = 4.95 1 V $IBF30 = -0.1 gauss l0004D295

  2. Submersible Unmanned Aerial Vehicle: Configuration Design and Analysis Based on Computational Fluid Dynamics

    Directory of Open Access Journals (Sweden)

    Wang Qinyang

    2017-01-01

    Full Text Available Submersible aerial vehicle is capable of both flying in the air and submerging in the water. Advanced Research Project Agency (DARPA outlined a challenging set of requirements for a submersible aircraft and solicited innovative research proposals on submersible aircraft since 2008. In this paper, a conceptual configuration design scheme of submersible unmanned aerial vehicle is proposed. This submersible UAV lands on the surface of water, then adjusts its own density to entry water. On the contrary, it emerges from water by adjusting its own density and then takes off from the surface of water. Wing of the UAV is whirling wing. It is set along aircraft’s fuselage while submerging for lift reduction. We analysis aerodynamic and hydrodynamic performance of this UAV by CFD method, especially compare the hydrodynamic performance of the whirling wing configuration and normal configuration. It turns out that whirling wing is beneficial for submerging. This result proves that the configuration design scheme proposed in this paper is feasible and suitable for a submersible unmanned aerial vehicle.

  3. Surveying the Dynamic Radio Sky with the Long Wavelength Demonstrator Array

    CERN Document Server

    Lazio, T J W; Lane, W M; Gross, C; Kassim, N E; Ray, P S; Wood, D; York, J A; Kerkhoff, A; Hicks, B; Polisensky, E; Stewart, K; Dalal, N Paravastu; Cohen, A S; Erickson, W C

    2010-01-01

    This paper presents a search for radio transients at a frequency of 73.8 MHz (4 m wavelength) using the all-sky imaging capabilities of the Long Wavelength Demonstrator Array (LWDA). The LWDA was a 16-dipole phased array telescope, located on the site of the Very Large Array in New Mexico. The field of view of the individual dipoles was essentially the entire sky, and the number of dipoles was sufficiently small that a simple software correlator could be used to make all-sky images. From 2006 October to 2007 February, we conducted an all-sky transient search program, acquiring a total of 106 hr of data; the time sampling varied, being 5 minutes at the start of the program and improving to 2 minutes by the end of the program. We were able to detect solar flares, and in a special-purpose mode, radio reflections from ionized meteor trails during the 2006 Leonid meteor shower. We detected no transients originating outside of the solar system above a flux density limit of 500 Jy, equivalent to a limit of no more t...

  4. Extraction-Separation Performance and Dynamic Modeling of Orion Test Vehicles with Adams Simulation: 3rd Edition

    Science.gov (United States)

    Varela, Jose G.; Reddy, Satish; Moeller, Enrique; Anderson, Keith

    2017-01-01

    NASA's Orion Capsule Parachute Assembly System (CPAS) Project is now in the qualification phase of testing, and the Adams simulation has continued to evolve to model the complex dynamics experienced during the test article extraction and separation phases of flight. The ability to initiate tests near the upper altitude limit of the Orion parachute deployment envelope requires extractions from the aircraft at 35,000 ft-MSL. Engineering development phase testing of the Parachute Test Vehicle (PTV) carried by the Carriage Platform Separation System (CPSS) at altitude resulted in test support equipment hardware failures due to increased energy caused by higher true airspeeds. As a result, hardware modifications became a necessity requiring ground static testing of the textile components to be conducted and a new ground dynamic test of the extraction system to be devised. Force-displacement curves from static tests were incorporated into the Adams simulations, allowing prediction of loads, velocities and margins encountered during both flight and ground dynamic tests. The Adams simulation was then further refined by fine tuning the damping terms to match the peak loads recorded in the ground dynamic tests. The failure observed in flight testing was successfully replicated in ground testing and true safety margins of the textile components were revealed. A multi-loop energy modulator was then incorporated into the system level Adams simulation model and the effect on improving test margins be properly evaluated leading to high confidence ground verification testing of the final design solution.

  5. Traffic dynamics in empirical probe vehicle data studied with three-phase theory: Spatiotemporal reconstruction of traffic phases and generation of jam warning messages

    Science.gov (United States)

    Kerner, Boris S.; Rehborn, Hubert; Schäfer, Ralf-Peter; Klenov, Sergey L.; Palmer, Jochen; Lorkowski, Stefan; Witte, Nikolaus

    2013-01-01

    Empirical and theoretical analyses of the spatiotemporal dynamics of traffic flow reconstructed from randomly distributed probe vehicle data are presented. For the empirical analysis, probe vehicle data generated by TomTom’s navigation devices in the commercial TomTom’s HD-traffic service as well as road detector data measured at the same road section are used. A stochastic microscopic (car-following) three-phase model is further developed for simulations of a real empirical complex spatiotemporal traffic dynamics measured over a three-lane long road stretch with several different bottlenecks. Physical features and limitations of simulations of real spatiotemporal traffic dynamics are revealed. Phase transition points between free flow (F), synchronized flow (S), and wide moving jam (J) are identified along trajectories of empirical and simulated probe vehicles randomly distributed in traffic flow. As predicted by three-phase theory, the empirical probe vehicle data shows that traffic breakdown is an F→S transition and wide moving jams emerge only in synchronized flow, i.e., due to S→J transitions. Through the use of the simulations, it has been found that already about 2% of probe vehicle data allows us to reconstruct traffic dynamics in space and time with an accuracy that is high enough for most applications like the generation of jam warning messages studied in the article.

  6. A Dynamic Modeling Toolbox for Air Vehicle Vapor Cycle Systems (Postprint)

    Science.gov (United States)

    2013-10-01

    Transcritical Vapor Compression Systems.” Journal of Dynamic Systems, Measurement, and Control, 2004: 54-64. 7. Li, B, Otten, R, Chandan, V, Mohs , W...and Trystram, G. “Low Order Dynamic Model os a Vapor Compression Cycle for Process Control Design.” Journal of Food Process, 2003: 193-199. 13

  7. Varietal Dynamics and Yam Agro-Diversity Demonstrate Complex Trajectories Intersecting Farmers’ Strategies, Networks, and Disease Experience

    Science.gov (United States)

    Penet, Laurent; Cornet, Denis; Blazy, Jean-Marc; Alleyne, Angela; Barthe, Emilie; Bussière, François; Guyader, Sébastien; Pavis, Claudie; Pétro, Dalila

    2016-01-01

    Loss of varietal diversity is a worldwide challenge to crop species at risk for genetic erosion, while the loss of biological resources may hinder future breeding objectives. Loss of varieties has been mostly investigated in traditional agricultural systems where variety numbers are dramatically high, or for most economically important crop species for which comparison between pre-intensive and modern agriculture was possible. Varietal dynamics, i.e., turnover, or gains and losses of varieties by farmers, is nevertheless more rarely studied and while we currently have good estimates of genetic or varietal diversity for most crop species, we have less information as to how on farm agro-diversity changes and what cause its dynamics. We therefore investigated varietal dynamics in the agricultural yam system in the Caribbean island of Guadeloupe. We interviewed producers about varieties they cultivated in the past compared to their current varieties, in addition to characterizing yam cropping characteristics and both farm level and producers socio-economic features. We then used regression tree analyses to investigate the components of yam agro-diversity, varietal dynamics and impact of anthracnose on varieties. Our data demonstrated that no dramatic loss of varieties occurred within the last decades. Cultivation changes mostly affected widespread cultivars while frequency of uncommon varieties stayed relatively stable. Varietal dynamics nevertheless followed sub-regional patterns, and socio-economic influences such as producer age or farm crop diversity. Recurrent anthracnose epidemics since the 1970s did not alter varietal dynamics strongly, but sometimes translated into transition from Dioscorea alata to less susceptible species or into a decrease of yam cultivation. Factors affecting changes in agro-diversity were not relating to agronomy in our study, and surprisingly there were different processes delineating short term from long term varietal dynamics

  8. Varietal Dynamics and Yam Agro-Diversity Demonstrate Complex Trajectories Intersecting Farmers' Strategies, Networks, and Disease Experience.

    Science.gov (United States)

    Penet, Laurent; Cornet, Denis; Blazy, Jean-Marc; Alleyne, Angela; Barthe, Emilie; Bussière, François; Guyader, Sébastien; Pavis, Claudie; Pétro, Dalila

    2016-01-01

    Loss of varietal diversity is a worldwide challenge to crop species at risk for genetic erosion, while the loss of biological resources may hinder future breeding objectives. Loss of varieties has been mostly investigated in traditional agricultural systems where variety numbers are dramatically high, or for most economically important crop species for which comparison between pre-intensive and modern agriculture was possible. Varietal dynamics, i.e., turnover, or gains and losses of varieties by farmers, is nevertheless more rarely studied and while we currently have good estimates of genetic or varietal diversity for most crop species, we have less information as to how on farm agro-diversity changes and what cause its dynamics. We therefore investigated varietal dynamics in the agricultural yam system in the Caribbean island of Guadeloupe. We interviewed producers about varieties they cultivated in the past compared to their current varieties, in addition to characterizing yam cropping characteristics and both farm level and producers socio-economic features. We then used regression tree analyses to investigate the components of yam agro-diversity, varietal dynamics and impact of anthracnose on varieties. Our data demonstrated that no dramatic loss of varieties occurred within the last decades. Cultivation changes mostly affected widespread cultivars while frequency of uncommon varieties stayed relatively stable. Varietal dynamics nevertheless followed sub-regional patterns, and socio-economic influences such as producer age or farm crop diversity. Recurrent anthracnose epidemics since the 1970s did not alter varietal dynamics strongly, but sometimes translated into transition from Dioscorea alata to less susceptible species or into a decrease of yam cultivation. Factors affecting changes in agro-diversity were not relating to agronomy in our study, and surprisingly there were different processes delineating short term from long term varietal dynamics

  9. Dynamics of multirate sampled data control systems. [for space shuttle boost vehicle

    Science.gov (United States)

    Naylor, J. R.; Hynes, R. J.; Molnar, D. O.

    1974-01-01

    The effect was investigated of the synthesis approach (single or multirate) on the machine requirements for a digital control system for the space shuttle boost vehicle. The study encompassed four major work areas: synthesis approach trades, machine requirements trades, design analysis requirements and multirate adaptive control techniques. The primary results are two multirate autopilot designs for the low Q and maximum Q flight conditions that exhibits equal or better performance than the analog and single rate system designs. Also, a preferred technique for analyzing and synthesizing multirate digital control systems is included.

  10. Interactions between Flight Dynamics and Propulsion Systems of Air-Breathing Hypersonic Vehicles

    Science.gov (United States)

    2013-01-01

    states (x) and control variables (u) h = specific enthalpy [J/kg] H = reference height [m] I = moment or product of inertia divided by vehicle mass [m2...rad] ψE = elevon dihedral angle [rad] ω̇ = chemical reaction rate [kmol/m2·s] ωab = angular velocity vector between frames a and b [rad/s] Ωab...Rocket Theoretical maximum Hydrocarbon fuel in air Theoretical maximum Hydrogen fuel in air Figure 1.1: Approximate efficiency (specific impulse) as a

  11. Comparison performance of split plug-in hybrid electric vehicle and hybrid electric vehicle using ADVISOR

    Directory of Open Access Journals (Sweden)

    Mohd Rashid Muhammad Ikram

    2017-01-01

    Full Text Available Electric vehicle suffers from relatively short range and long charging times and consequently has not become an acceptable solution to the automotive consumer. The addition of an internal combustion engine to extend the range of the electric vehicle is one method of exploiting the high efficiency and lack of emissions of the electric vehicle while retaining the range and convenient refuelling times of a conventional gasoline powered vehicle. The term that describes this type of vehicle is a hybrid electric vehicle. Many configurations of hybrid electric vehicles have been designed and implemented, namely the series, parallel and power-split configurations. This paper discusses the comparison between Split Plug-in Hybrid Electric Vehicle(SPHEV and Hybrid Electric Vehicle(HEV. Modelling methods such as physics-based Resistive Companion Form technique and Bond Graph method are presented with powertrain component and system modelling examples. The modelling and simulation capability of existing tools such as ADvanced VehIcle SimulatOR (ADVISOR is demonstrated through application examples. Since power electronics is indispensable in hybrid vehicles, the issue of numerical oscillations in dynamic simulations involving power electronics is briefly addressed.

  12. Dynamic Vibration Analysis of Heavy Vehicle Truck Transmission Gearbox Housing Using FEA

    Directory of Open Access Journals (Sweden)

    Ashwani Kumar

    2014-09-01

    Full Text Available The main objective of this original research article is to study the loose fixture mounting affect of heavy vehicle transmission gearbox housing. The studies were completed in three phases. In first phase the aim was to find the actual suitable boundary condition. After finding the boundary condition in second phase the fixture bolts were loosened to monitor the affect of looseness and in third phase the positional looseness based study were completed. The looseness of transmission housing causes heavy vibration and noise. In order to prevent this noise and vibration the transmission housing is tightly mounted on the chassis frame using bolts. In our design transmission housing is constraint on chassis frame using 37 bolts. Truck transmission system determines the level of noise together with the chassis, engine and bodywork. Vehicle transmissions under torsional vibration condition caused rattling and clattering noises. Reciprocity Principle was used to determine the failure frequencies for transmission housing. In reciprocity principle gear and shafts are suppressed and all the forces transmitted through the bearings are applied on the empty housing. FEA based ANSYS 14.5 has been used as analysis tool. The free vibration frequency for zero displacement condition varies from 1669 Hz to 2865 Hz and for loose transmission casing frequency varies from 1311 Hz to 3110 Hz. The analysis have theoretical and practical aspects and useful for transmission housing structure optimization.

  13. Dynamic Analysis of Heavy Vehicle Medium Duty Drive Shaft Using Conventional and Composite Material

    Science.gov (United States)

    Kumar, Ashwani; Jain, Rajat; Patil, Pravin P.

    2016-09-01

    The main highlight of this study is structural and modal analysis of single piece drive shaft for selection of material. Drive shaft is used for torque carrying from vehicle transmission to rear wheel differential system. Heavy vehicle medium duty transmission drive shaft was selected as research object. Conventional materials (Steel SM45 C, Stainless Steel) and composite materials (HS carbon epoxy, E Glass Polyester Resin Composite) were selected for the analysis. Single piece composite material drive shaft has advantage over conventional two-piece steel drive shaft. It has higher specific strength, longer life, less weight, high critical speed and higher torque carrying capacity. The main criteria for drive shaft failure are strength and weight. Maximum modal frequency obtained is 919 Hz. Various harmful vibration modes (lateral vibration and torsional vibration) were identified and maximum deflection region was specified. For single-piece drive shaft the natural bending frequency should be higher because it is subjected to torsion and shear stress. Single piece drive shaft was modelled using Solid Edge and Pro-E. Finite Element Analysis was used for structural and modal analysis with actual running boundary condition like frictional support, torque and moment. FEA simulation results were validated with experimental literature results.

  14. Modeling and Analysis of Static and Dynamic Characteristics of Nonlinear Seat Suspension for Off-Road Vehicles

    Directory of Open Access Journals (Sweden)

    Zhenhua Yan

    2015-01-01

    Full Text Available Low-frequency vibrations (0.5–5 Hz that harm drivers occur in off-road vehicles. Thus, researchers have focused on finding methods to effectively isolate or control low-frequency vibrations. A novel nonlinear seat suspension structure for off-road vehicles is designed, whose static characteristics and seat-human system dynamic response are modeled and analyzed, and experiments are conducted to verify the theoretical solutions. Results show that the stiffness of this nonlinear seat suspension could achieve real zero stiffness through well-matched parameters, and precompression of the main spring could change the nonlinear seat suspension performance when a driver’s weight changes. The displacement transmissibility curve corresponds with the static characteristic curve of nonlinear suspension, where the middle part of the static characteristic curve is gentler and the resonance frequency of the displacement transmissibility curve and the isolation minimum frequency are lower. Damping should correspond with static characteristics, in which the corresponding suspension damping value should be smaller given a flatter static characteristic curve to prevent vibration isolation performance reduction.

  15. Combination of vehicle routing models and dynamic traffic simulation for city logistics applications

    OpenAIRE

    Grzybwska, Hanna

    2012-01-01

    The urban network is a highly dynamic system. Thus, a modern and efficient fleet management in urban areas should account for dynamics of traffic conditions, variability in travel times, changes in demand and fleet availability. All these factors significantly affect the distribution of goods and the provision of services. As a consequence, the freight operations optimizing approaches should be based on the time-dependent travel time estimates rather than on the average static values commonly...

  16. Extraction-Separation Performance and Dynamic Modeling of Orion Test Vehicles with Adams Simulation: 2nd Edition

    Science.gov (United States)

    Fraire, Usbaldo, Jr.; Anderson, Keith; Varela, Jose G.; Bernatovich, Michael A.

    2015-01-01

    NASA's Orion Capsule Parachute Assembly System (CPAS) project has advanced into the third generation of its parachute test campaign and requires technically comprehensive modeling capabilities to simulate multi-body dynamics (MBD) of test articles released from a C-17. Safely extracting a 30,000 lbm mated test article from a C-17 and performing stable mid-air separation maneuvers requires an understanding of the interaction between elements in the test configuration and how they are influenced by extraction parachute performance, aircraft dynamics, aerodynamics, separation dynamics, and kinetic energy experienced by the system. During the real-time extraction and deployment sequences, these influences can be highly unsteady and difficult to bound. An avionics logic window based on time, pitch, and pitch rate is used to account for these effects and target a favorable separation state in real time. The Adams simulation has been employed to fine-tune this window, as well as predict and reconstruct the coupled dynamics of the Parachute Test Vehicle (PTV) and Cradle Platform Separation System (CPSS) from aircraft extraction through the mid-air separation event. The test-technique for the extraction of CPAS test articles has evolved with increased complexity and requires new modeling concepts to ensure the test article is delivered to a stable test condition for the programmer phase. Prompted by unexpected dynamics and hardware malfunctions in drop tests, these modeling improvements provide a more accurate loads prediction by incorporating a spring-damper line-model derived from the material properties. The qualification phase of CPAS testing is on the horizon and modeling increasingly complex test-techniques with Adams is vital to successfully qualify the Orion parachute system for human spaceflight.

  17. Demonstration of impact performance of the nuclear transport package in on-site hypothetical collision scenarios by a heavy goods vehicle

    Energy Technology Data Exchange (ETDEWEB)

    Tso, C.F.; Izatt, C. [Arup (United Kingdom)

    2004-07-01

    Spent fuel modules are contained in Module Removal Container (MRC) during on-site transport at the D154 facilities in the Devonport Naval Dockyard in the United Kingdom. The container is transported on its own on a Low Level Transfer Trolley (LLTT) and accommodated within a Transfer Frame. The LLTT travels on rails and moves either under its own power or towed by a Rail Tug Unit. The Transfer Frame provides a secure means of support to the MRC during transit and provides impact protection in the event of collision. The MRC is accommodated within the Transfer Frame by way of a sub-frame assembly. It rests on its sub-frame and is held in a vertical position by a number of support arms bolted to the Frame. The Transfer Frame is attached to the Low Level Transfer Trolley by a combination of bolts and shear pins. The combination of LLTT, Transfer Frame, sub-frame and a MRC is known as a Nuclear Transport Package (NTP). The design basis vehicle impact accident specifies a collision from a 20 tonne vehicle travelling at 20 mph from any direction. In order to satisfy the safety functional requirements, the NTP is required to meet the following conditions: The NTP should not overturn as a complete assembly following the impact. The Transfer Frame should not detach from the LLTT, and with the attachments remaining within the Level D stress limits specified in the ASME Boiler and Pressure Vessel Code Section 3. The MRC should be shown to withstand any potential impacts of the vehicle in the event of failure of any of the frame members. The frame must not transmit as a result of the vehicle impact, to either container, loads that would compromise their shielding and containment boundaries. The performance of the NTP was substantiated by finite element (FE) analysis, using the explicit non-linear transient code LS-DYNA. The work formed part of the site license application for the D154 facilities.

  18. Serret-Frenet frame based on path following control for underactuated unmanned surface vehicles with dynamic uncertainties

    Institute of Scientific and Technical Information of China (English)

    廖煜雷; 张铭钧; 万磊

    2015-01-01

    The path following problem for an underactuated unmanned surface vehicle (USV) in the Serret−Frenet frame is addressed. The control system takes account of the uncertain influence induced by model perturbation, external disturbance, etc. By introducing the Serret−Frenet frame and global coordinate transformation, the control problem of underactuated system (a nonlinear system with single-input and ternate-output) is transformed into the control problem of actuated system (a single-input and single-output nonlinear system), which simplifies the controller design. A backstepping adaptive sliding mode controller (BADSMC) is proposed based on backstepping design technique, adaptive method and theory of dynamic slide model control (DSMC). Then, it is proven that the state of closed loop system is globally stabilized to the desired configuration with the proposed controller. Simulation results are presented to illustrate the effectiveness of the proposed controller.

  19. Model and Two-stage Algorithm on Dynamic Vehicle Routing Problem%一类动态车辆路径问题模型和两阶段算法

    Institute of Scientific and Technical Information of China (English)

    饶卫振; 金淳; 刘锋; 杨磊

    2015-01-01

    In order to effectively solve dynamic vehicle routing problem (DVRP), this paper analyzes the substantial effect of four main categories of dynamic information on classical vehicle routing problem, and transform DVRP into multiple static fleet size and mixed open vehicle routing problems (FSMOVRP). And FSMOVRP could be further converted to multiple capacitated vehicle routing problems (CVRP). The model based on CVRP is built up for DVRP. After that a two-stage algorithm is proposed to solve DVRP model according to the analysis of DVRP characteristics. In the first stage, a fast construction algorithm with merely O(nlogn) complexity is proposed on the basis of delivery region cutting strategy by K-d trees method. In the second stage, a hybrid local search algorithm is designed by analysis of structural principal of algorithm’s solution searching space. Finally for the purpose of algorithm verification, we design and solve 36 DVRP instances generated from 12 large scale CVRP benchmark instances. The results demonstrate the effectiveness of the model and two-stage solving algorithm.%针对一类动态车辆路径问题,分析4种主要类型动态信息对传统车辆路径问题的本质影响,将动态车辆路径问题(Dynamic Vehicle Routing Problem, DVRP)转化为多个静态的多车型开放式车辆路径问题(The Fleet Size and Mixed Open Vehicle Routing Problem, FSMOVRP),并进一步转化为多个带能力约束车辆路径问题(Capacitated Vehicle Routing Problem, CVRP),基于CVRP模型建立了DVRP模型;然后,在分析DVRP问题特点基础上,提出两阶段算法,第一阶段基于利用K-d trees对配送区域进行分割的策略,提出了复杂度仅为O(nlogn)的快速构建型算法,第二阶段通过分析算法搜索解空间结构原理,设计混合局部搜索算法;最后,基于现有12个大规模CVRP标准算例,设计并求解36个DVRP算例。求解结果表明了模型和两阶段算法的有效性。

  20. The Shock and Vibration Bulletin. Part 2. Dynamic Testing, Flight Vehicle Dynamics, Seismic Loads and Fluid-Structure Interaction

    Science.gov (United States)

    1985-06-01

    HYDRAULIC TECHNOLOGY CAPABILITIES % SYSTEMS INSTRON 0 TO 600 Hz s COMERCIALLY * EXPENSIVE (M0121) AVAILABLE SYSTEM 0 CARE NEEDED TO *[31 AVOID POOR DYNAMIC...The induced ground motions were modeled after the El Centro (1941) earthquake. Results include absolute horizontal and vertical displacement-time

  1. Leader Follower Formation Control of Ground Vehicles Using Dynamic Pixel Count and Inverse Perspective Mapping

    Directory of Open Access Journals (Sweden)

    S.M.Vaitheeswarana

    2014-10-01

    Full Text Available This paper deals with leader-follower formations of non-holonomic mobile robots, introducing a formation control strategy based on pixel counts using a commercial grade electro optics camera. Localization of the leader for motions along line of sight as well as the obliquely inclined directions are considered based on pixel variation of the images by referencing to two arbitrarily designated positions in the image frames. Based on an established relationship between the displacement of the camera movement along the viewing direction and the difference in pixel counts between reference points in the images, the range and the angle estimate between the follower camera and the leader is calculated. The Inverse Perspective Transform is used to account for non linear relationship between the height of vehicle in a forward facing image and its distance from the camera. The formulation is validated with experiments.

  2. Hybrid propulsion system with a gyro component for economic and dynamic operation. [of motor vehicle

    Science.gov (United States)

    Giera, B.; Helling, J.; Schreck, J.

    1977-01-01

    The design of a hybrid drive with gyro components is described and its drive components for a medium class private car are discussed. The gyro component affects the short-period output of the drive by accelerating and slowing down and -- because of the mechanical transfer of kinetic energy between the gyro and the vehicle -- it affects also the energy balance in the case of intermittent operation. Energy can be taken in as desired either in the form of fuel or as fuel and current. A high energy recovery efficiency as well as the favorable operating range of the interval combustion engine makes it possible to reduce the fuel consumption per unit distance travelled to almost half that for a private car with a traditional engine.

  3. Modal identities for elastic bodies, with application to vehicle dynamics and control

    Science.gov (United States)

    Hughes, P. C.

    1980-01-01

    It is a standard procedure to analyze a flexible vehicle in terms of its vibration frequencies and mode shapes. However, the entire mode shape is not needed per se, but two integrals of the mode shape, pi and hi, which correspond to the momentum and angular momentum in Mode i. Together with the natural frequencies omega-i, these modal parameters satisfy several important identities, 25 of which are derived in this paper. Expansions in terms of both constrained and unconstrained modes are considered. A simple illustrative example is included. The paper concludes with some remarks on the theoretical and practical utility of these results, and several potential extensions to the theory are suggested.

  4. OPTIMAL CONTROL FOR ELECTRIC VEHICLE STABILIZATION

    Directory of Open Access Journals (Sweden)

    MARIAN GAICEANU

    2016-01-01

    Full Text Available This main objective of the paper is to stabilize an electric vehicle in optimal manner to a step lane change maneuver. To define the mathematical model of the vehicle, the rigid body moving on a plane is taken into account. An optimal lane keeping controller delivers the adequate angles in order to stabilize the vehicle’s trajectory in an optimal way. Two degree of freedom linear bicycle model is adopted as vehicle model, consisting of lateral and yaw motion equations. The proposed control maintains the lateral stability by taking the feedback information from the vehicle transducers. In this way only the lateral vehicle’s dynamics are enough to considerate. Based on the obtained linear mathematical model the quadratic optimal control is designed in order to maintain the lateral stability of the electric vehicle. The numerical simulation results demonstrate the feasibility of the proposed solution.

  5. Simulation Research on Dynamic Performances of Railway Vehicles Based on SIMPACK%基于SIMPACK的轨道车辆动态性能仿真分析

    Institute of Scientific and Technical Information of China (English)

    黄安宁; 易智民; 张安全

    2013-01-01

    The whole dynamic modeling of a type of railway vehicle is modeled using the multi -body dynamics software SIMPACK. The linear and nonlinear critical speed of the railway vehicle is obtained by simulating different speeds through the linear track, whereas the curve passing ability of the railway vehicle is obtained by using different speeds through the different curved railway tracks. The stability index of the railway vehicle is analyzed under different speeds. The finite element modal of the vehicle is obtained with the finite element analysis software ANSYS, which is inputted into SIMPACK to model the multi - body system (MBS) dynamic model with rigid and flexible coupling. The dynamic performance of a type of railway vehicles can be thus obtained by solving this model.%利用多体动力学软件SIMPACK对某型轨道车辆进行整体建模;采用不同速度通过直线轨道线路而获得车辆的线性和非线性临界速度;使轨道车辆通过不同的曲线线路而获得其曲线通过能力;分析了轨道车辆在不同速度下的平稳性指标;采用有限元分析软件ANSYS获得车体的有限元模态文件,输入SIMPACK中获得刚柔耦合的多体动力学模型,并获得车体刚柔耦合的动态性能.

  6. Real-time detection of moving objects in a dynamic scene from moving robotic vehicles

    Science.gov (United States)

    Ansar, A.; Talukder, S.; Goldberg, L.; Matthies, A.

    2003-01-01

    Dynamic scene perception is currently limited to detection of moving objects from a static platform or scenes with flat backgrounds. We discuss novel methods to segment moving objects in the motion field formed by a moving camera/robotic platform in real time.

  7. The dynamic behaviour of man-wide vehicles with an automatic active tilting mechanism

    NARCIS (Netherlands)

    Pauwelussen, J.P.

    1999-01-01

    The major advantage of a motorcycle with respect to a passenger car is the possibility of the driver to tilt during cornering and thereby maintaining stability whereas a passenger car will suffer from the risk of capsizing at high speed. This observation has lead Brink Dynamics to create and develop

  8. Real-time detection of moving objects in a dynamic scene from moving robotic vehicles

    Science.gov (United States)

    Ansar, A.; Talukder, S.; Goldberg, L.; Matthies, A.

    2003-01-01

    Dynamic scene perception is currently limited to detection of moving objects from a static platform or scenes with flat backgrounds. We discuss novel methods to segment moving objects in the motion field formed by a moving camera/robotic platform in real time.

  9. The Wheel-Rail Contact Problem in Vehicle Dynamic Simulation: Modeling of Train-Turnout Interaction

    NARCIS (Netherlands)

    Burgelman, N.

    2016-01-01

    One of the major costs incurred by railway companies is the maintenance of turnouts.This situation occurs because the large dynamic forces between the wheels of a train and the rails of a turnout cause excessive wear, rolling contact fatigue and rapid degradation of other components. A thorough unde

  10. A Dynamic Behaviour Analysis on the Frequency Control Capability of Electric Vehicles

    DEFF Research Database (Denmark)

    Zarogiannis, Athanasios; Marinelli, Mattia; Træholt, Chresten

    2014-01-01

    The paper presents results of a study on the dynamic response of Electric Vehicle’s (EV) when participating in frequency control of an islanded system. The following cases were considered: when there is no EV performing frequency control, when the EV participates in primary frequency control...

  11. Continuous Dynamic Simulation of Nonlinear Aerodynamics/Nonlinear Structure Interaction (NANSI) for Morphing Vehicles

    Science.gov (United States)

    2010-03-31

    comprised linear structural dynamics (e.g. [7.2]), vibro-acoustics, aeroelasticity (e.g. [7.1]), rotordynamics [7.7] (including the joint simulation...2006. [7.7] Murthy, R., Mignolet, M.P., and El-Shafei, A., "Nonparametric Stochastic Modeling of Structural Uncertainty in Rotordynamic

  12. Reduction of global effects on vehicles after IED detonations

    Institute of Scientific and Technical Information of China (English)

    V.DENEFELD; N.HEIDER; A.HOLZWARTH; A.S€ATTLER; M.SALK

    2014-01-01

    Global effects caused by the detonation of an IED near a military vehicle induce subsequent severe acceleration effects on the vehicle occupants. Two concepts to minimize these global effects were developed, with the help of a combined method based on a scaled experimental technology and numerical simulations. The first concept consists in the optimization of the vehicle shape to reduce the momentum transfer and thus the occupant loading. Three scaled V-shaped vehicles with different ground clearances were built and compared to a reference vehicle equipped with a flat floor. The second concept, called dynamic impulse compensation (DIC), is based on a momentum compensation technique. The principal possibility of this concept was demonstrated on a scaled vehicle. In addition, the numerical simulations have been performed with generic full size vehicles including dummy models, proving the capability of the DIC technology to reduce the occupant loading.

  13. Vehicle Sprung Mass Estimation for Rough Terrain

    Science.gov (United States)

    2011-03-01

    drivetrain controllers. These autonomous systems and controllers schedule gear shifts, actuate brakes, induce steer, schedule fuel injection, warn...longitudinal vehicle dynamics, drivetrain shuffle dynamics, or combined lateral, yaw, and roll dynamics to estimate the vehicle mass. Despite the research

  14. State transformation-based dynamic visual servoing for an unmanned aerial vehicle

    Science.gov (United States)

    Xie, Hui; Lynch, Alan F.

    2016-05-01

    In this paper, we propose a visual servoing control for a quadrotor unmanned aerial vehicle (UAV) which is based on a state transformation technique. The UAV is equipped with a single downwards facing camera, and the motion control objective is the regulation of relative displacement and yaw to a stationary visual target located on the ground. The state transformation is defined by a system of partial differential equations (PDEs) which eliminate roll and pitch rate dependence in the transformed image feature kinematics. A method for computing the general solutions of these PDEs is given, and we show a particular solution reduces to an established virtual camera approach. We treat point and line cases and introduce image moment features defined in the virtual camera image plane. Robustness of the control design is improved by accounting for attitude measurement bias, and uncertainty in thrust gain, mass, and image feature depth. The asymptotic stability of the closed-loop is proven. The method is based on a simple proportional-integral-derivative (PID) structure which can be readily implemented on-board. Experimental results show improved performance relative to previous work.

  15. DEVELOPMENT OF A SIMULATION TOOL FOR THE DYNAMIC ANALYSIS OF RAILWAY VEHICLE - TRACK INTERACTION

    OpenAIRE

    2015-01-01

    The importance of modelling and simulation in the field of railway systems has greatly increased in the last decades. Various commercial simulation packages have been developed and are used to analyse the dynamic performance of railway systems. However, although sometimes the user needs to analyse various non-standard solutions, the possibility to integrate further modifications into the structure of such software is quite limited. Therefore, in some cases, in particular for specific modellin...

  16. A novel model for determining the amplitude-wavelength limits of track irregularities accompanied by a reliability assessment in railway vehicle-track dynamics

    Science.gov (United States)

    Xu, Lei; Zhai, Wanming

    2017-03-01

    The loads on a vehicle and the vibrations transmitted to track infrastructures due to the operation of rolling stocks are mainly determined by the irregularities of the track profile. Hence, it is rather important to ascertain the limits of track irregularities, including amplitudes and wavelengths, to guarantee the dynamic performance of running vehicles and guiding tracks. Furthermore, the operation and management levels as well as irregularity status for different railways are highly dissimilar. Therefore, it is a necessary to conduct a reliability assessment for a specific railway line. In the present work, a large amount of measured track irregularities are concentrated as a group form of the track irregularity power spectrum density. A track irregularity inversion model is presented to obtain realistic representations of track profile deformations with information regarding amplitudes, wavelengths and probabilities. Then, the methodologies for determining the limits of track irregularities and achieving a reliability assessment are presented by introducing the probability density evolution method and development of a Wavelet-Wigner-Hough method. Using the vehicle-track interaction model, numerical studies for confirming the limits of track irregularities and evaluating the reliability of the dynamic performance of the vehicle can be conducted to provide valuable suggestions. This paper offers new possibilities for studying the limit amplitudes, characteristic wavelengths of track irregularities as well as corresponding reliabilities when a railway vehicle runs under different track geometric conditions.

  17. Cabin air temperature of parked vehicles in summer conditions: life-threatening environment for children and pets calculated by a dynamic model

    Science.gov (United States)

    Horak, Johannes; Schmerold, Ivo; Wimmer, Kurt; Schauberger, Günther

    2016-07-01

    In vehicles that are parked, no ventilation and/or air conditioning takes place. If a vehicle is exposed to direct solar radiation, an immediate temperature rise occurs. The high cabin air temperature can threaten children and animals that are left unattended in vehicles. In the USA, lethal heat strokes cause a mean death rate of 37 children per year. In addition, temperature-sensitive goods (e.g. drugs in ambulances and veterinary vehicles) can be adversely affected by high temperatures. To calculate the rise of the cabin air temperature, a dynamic model was developed that is driven by only three parameters, available at standard meteorological stations: air temperature, global radiation and wind velocity. The transition from the initial temperature to the constant equilibrium temperature depends strongly on the configuration of the vehicle, more specifically on insulation, window area and transmission of the glass, as well as on the meteorological conditions. The comparison of the model with empirical data showed good agreement. The model output can be applied to assess the heat load of children and animals as well as temperature-sensitive goods, which are transported and/or stored in a vehicle.

  18. Simulation and Analysis of Dynamic Performance of Electric Vehicle%电动汽车动力性能仿真分析

    Institute of Scientific and Technical Information of China (English)

    王兴; 秦东晨; 裴东杰

    2012-01-01

    为了使电动汽车满足动力需求,需要对其动力性能做深入的研究.以车辆系统动力学为理论基础,基于ADVISOR软件,建立了汽车部件和整车模型.选择道路循环工况,设置加速性能和爬坡性能的测试参数,运行仿真,并对仿真结果进行分析,分析结果表明电动汽车的动力性符合实际工作要求.在电动汽车设计和开发阶段,采用该研究方法得到的仿真结果,可以作为设计人员重要的参考依据.%The dynamic performance of electric vehicle is essential and needs to be researched when the power demand of electric vehicle must be salisfied.On the theoretical basis of vehicle system dynamics, the components of electric vehicle and vehicle model are built up based on the software of ADVISOR After choosing the road driving cycle and setting the parameters of acceleration and grade ability, the simulation of dynamic performance is run, and then the output results of simulation is analyzed.The obtained conclusions are in line with the actual working condition.ln the design and research phase of electric vehicle,the research method and the simulation results can, be used as the significant reference and guidance for designers.

  19. A passive method to stabilize an airborne vehicle

    Directory of Open Access Journals (Sweden)

    Timo Sailaranta

    2014-06-01

    Full Text Available A method of augmenting an airborne vehicle for short-period dynamics and stability by passive means is presented in this study. A trajectory-phase disturbance rejection capability is achieved for an unguided fin-stabilized vehicle by flexible mounting of the fins to the vehicle body. The deflecting fins lag the body oscillation such that the harmonic oscillation can be quickly dampened. The amount of fin deflection may be chosen by a hinge-line location; among other things, the vehicle damping behaviour is largely determined by this choice. Linear theory is applied and 6-DOF simulations are carried out to demonstrate the approach suitability for the task.

  20. Development and Evaluation of Sensor Concepts for Ageless Aerospace Vehicles: Report 6 - Development and Demonstration of a Self-Organizing Diagnostic System for Structural Health Monitoring

    Science.gov (United States)

    Batten, Adam; Edwards, Graeme; Gerasimov, Vadim; Hoschke, Nigel; Isaacs, Peter; Lewis, Chris; Moore, Richard; Oppolzer, Florien; Price, Don; Prokopenko, Mikhail; Scott, Andrew; Wang, Peter

    2010-01-01

    This report describes a significant advance in the capability of the CSIRO/NASA structural health monitoring Concept Demonstrator (CD). The main thrust of the work has been the development of a mobile robotic agent, and the hardware and software modifications and developments required to enable the demonstrator to operate as a single, self-organizing, multi-agent system. This single-robot system is seen as the forerunner of a system in which larger numbers of small robots perform inspection and repair tasks cooperatively, by self-organization. While the goal of demonstrating self-organized damage diagnosis was not fully achieved in the time available, much of the work required for the final element that enables the robot to point the video camera and transmit an image has been completed. A demonstration video of the CD and robotic systems operating will be made and forwarded to NASA.

  1. The concept design and dynamics analysis of a novel vehicle suspension mechanism with invariable orientation parameters

    Science.gov (United States)

    Zhao, Jing-Shan; Li, Lingyang; Chen, Liping; Zhang, Yunqing

    2010-12-01

    This paper starts with a classical mechanism synthesis problem and focuses on the concept design and dynamics analysis of an independent suspension that has invariable orientation parameters when the wheel moves up (jounces) and down (rebounds). The paper first proposes a symmetric redundant constraint suspension structure that has invariable orientation parameters. And then, it analyses the mechanism mobility with the reciprocal screw theory, after which it establishes the displacement constraint equations of the suspension. This type of suspension has all the advantages of the sliding pillar suspension but overcomes its disadvantage of over-wearing. Through differentiating the constraint equations with respect to time, it obtains the kinematics relationship and builds up the dynamics equations of the suspension via Newton-Euler method. Numerical simulations indicate that this kind of independent suspensions should not only eliminate the shambling shocks induced by the jumping of wheels but also decrease the abrasion of the wheels. Therefore, this kind of independent suspensions can obviously improve the ride and handling properties of advanced automobiles.

  2. The Shock and Vibration Bulletin. Part 3. Analytical Methods, Dynamic Analysis, Vehicle Systems

    Science.gov (United States)

    1981-05-01

    bpp ’ (24) L V* ki k2K 2 + (1 (ZT~~ - !I + !- 2) Y(IJ) and the value of bpp ’ can be tabulated as in 101 L .’blel1I...mI Table It. Values of bpp in Equation (24) The assembling of equations for a gun dynamics problem is more involved. The basic r1 procedures...20,, Fig. : RePos Of Crane Boom for Sinusoidaltinpu 64 60, t x 40. .5 . / KA 0-020 " - S./ 30, % 0.075 AWN 20 10, - (rw/) Fig. 10: Plot of Jetjvs w for %0 Variation 60 omir~u woa 9ao$.l/a Kp- . MA1 /

  3. Machine learning from computer simulations with applications in rail vehicle dynamics

    Science.gov (United States)

    Taheri, Mehdi; Ahmadian, Mehdi

    2016-05-01

    The application of stochastic modelling for learning the behaviour of a multibody dynamics (MBD) models is investigated. Post-processing data from a simulation run are used to train the stochastic model that estimates the relationship between model inputs (suspension relative displacement and velocity) and the output (sum of suspension forces). The stochastic model can be used to reduce the computational burden of the MBD model by replacing a computationally expensive subsystem in the model (suspension subsystem). With minor changes, the stochastic modelling technique is able to learn the behaviour of a physical system and integrate its behaviour within MBD models. The technique is highly advantageous for MBD models where real-time simulations are necessary, or with models that have a large number of repeated substructures, e.g. modelling a train with a large number of railcars. The fact that the training data are acquired prior to the development of the stochastic model discards the conventional sampling plan strategies like Latin Hypercube sampling plans where simulations are performed using the inputs dictated by the sampling plan. Since the sampling plan greatly influences the overall accuracy and efficiency of the stochastic predictions, a sampling plan suitable for the process is developed where the most space-filling subset of the acquired data with ? number of sample points that best describes the dynamic behaviour of the system under study is selected as the training data. Results indicated that the stochastic modelling technique is effective in improving the computational efficiency of the MBD model without compromising the accuracy of the predictions, although the improvements in the computational efficiency of the technique could not be quantified due to the inefficiencies associated with transferring the data between multiple software packages (SIMPACK, SIMULINK).

  4. Three-dimensional computer simulation at vehicle collision using dynamic model. Application to various collision types; Rikigaku model ni yoru jidosha shototsuji no sanjigen kyodo simulation. Shushu no shototsu keitai eno tekiyo

    Energy Technology Data Exchange (ETDEWEB)

    Abe, M.; Morisawa, M. [Musashi Institute of Technology, Tokyo (Japan); Sato, T. [Keio University, Tokyo (Japan); Kobayashi, K. [Molex-Japan Co. Ltd., Tokyo (Japan)

    1997-10-01

    The past study of safety at vehicle collision pays attention to phenomena within the short time from starting collision, and the behavior of rollover is studied separating from that at collision. Most simulations of traffic accident are two-dimensional simulations. Therefore, it is indispensable for vehicle design to the analyze three-dimensional and continuous behavior from crash till stopping. Accordingly, in this study, the three-dimensional behavior of two vehicles at collision was simulated by computer using dynamic models. Then, by comparison of the calculated results with real vehicles` collision test data, it was confirmed that dynamic model of this study was reliable. 10 refs., 6 figs., 3 tabs.

  5. Numerical Modelling of the Dynamic Response of High-Speed Railway Bridges Considering Vehicle-Structure and Structure-Soil-Structure Interaction

    DEFF Research Database (Denmark)

    Bucinskas, Paulius; Agapii, L.; Sneideris, J.

    2015-01-01

    The aim of this paper is the dynamic analysis of a multi-support bridge structure exposed to high-speed railway traffic. The proposed computational model has a unified approach for simultaneously accounting for the bridge structure response, soil response and forces induced by the vehicle...... is idealized as a multi-degree-of-freedom system, modelled with two layers of spring-dashpot suspension systems. Coupling the vehicle system and railway track is realized through interaction forces between the wheels and the rail, where the irregularities of the track are implemented as a random stationary...... stochastic process. The soil body is considered as a layered half-space employing the transfer-matrix methods to obtain the Green's functions in the frequency domain. An iteration procedure is proposed for simultaneously solving the time-domain solution of the multi-degree-of-freedom vehicle affected...

  6. Effect of stiffness and movement speed on selected dynamic torque characteristics of hydraulic-actuation joystick controls for heavy vehicles.

    Science.gov (United States)

    Oliver, Michele; Rogers, Robert; Rickards, Jeremy; Tingley, Maureen; Biden, Edmund

    2006-02-22

    The purpose of this work was to quantify the effects of joystick stiffness and movement speed on the dynamic torque characteristics of hydraulic-actuation joystick controls, as found in off-road vehicles, as one of the initial steps towards the development of a joystick design protocol. Using a previously developed mathematical model in which a hydraulic-actuation joystick is assumed to rotate about two axes where the rotation origin is a universal joint, the dynamic torque characteristics incurred by an operator were predicted. Utilizing a laboratory mock-up of an excavator cab environment, three actuation torque characteristics (peak torque, angular impulse and deceleration at the hard endpoint) were quantified for nine unskilled joystick operators during the use of a commonly used North American hydraulic-actuation joystick. The six different experimental conditions included combinations of three joystick stiffnesses and two movement speeds. The highest instantaneous input torque over the course of the joystick movement (not including the hard endpoint) was evaluated using the peak torque value. Angular impulse provided an indication of the sustained exposure to force. The third indicator, deceleration at the hard endpoint, was included to provide a description of impact loading on the hand as the joystick came to a sudden stop. The most important result of this work is that the dynamic torque characteristics incurred during hydraulic-actuation joystick use are substantial. While the peak torque values were not very different between the fast and slow motion conditions, the high decelerations even for slow movements observed at maximum excursion of the joystick indicate that the dynamics do matter. On the basis of deceleration at the hard endpoint and peak torque, the joystick movements that require the highest values for a combination of torque variables are the side-to-side ones. This suggests that less stiff balance and return springs should be considered for

  7. Dynamic Response and Maneuvering Strategies of a Hybrid Autonomous Underwater Vehicle in Hovering

    Science.gov (United States)

    2009-02-01

    mapping and photo/ video survey. Previous missions have demonstrated a need for the ability to closely follow non-smooth bottoms as well as terrain...located at 1 4 chord from the leading edge for a thin foil [42], for which the moment arm to the body origin is defined as rCP . The differential...moment is then defined as: dMtot = rCP × dFtot (3.31) the total forces can be found by integrating the sectional drag and lift forces onto the entire

  8. Pedestrian intention prediction based on dynamic fuzzy automata for vehicle driving at nighttime

    Science.gov (United States)

    Kwak, Joon-Young; Ko, Byoung Chul; Nam, Jae-Yeal

    2017-03-01

    In this paper, we propose a novel algorithm that can predict a pedestrian's intention using images captured by a far-infrared thermal camera mounted on a moving car at nighttime. To predict a pedestrian's intention in consecutive sequences, we use the dynamic fuzzy automata (DFA) method, which not only provides a systemic approach for handling uncertainty but also is able to handle continuous spaces. As the spatio-temporal features, the distance between the curbs and the pedestrian and the pedestrian's velocity and head orientation are used. In this study, we define four intention states of the pedestrian: Standing-Sidewalk (S-SW), Walking-Sidewalk (W-SW), Walking-Crossing (W-Cro), and Running-Crossing (R-Cro). In every frame, the proposed system determines the final intention of the pedestrian as 'Stop' if the pedestrian's intention state is S-SW or W-SW. In contrast, the proposed system determines the final intention of a pedestrian as 'Cross' if the pedestrian's intention state is W-Cro or R-Cro. A performance comparison with other related methods shows that the performance of the proposed algorithm is better than that of other related methods. The proposed algorithm was successfully applied to our dataset, which includes complex environments with many pedestrians.

  9. Vehicle dynamic performance evaluation based on 'Kansei'; Kansei ni motozuku sharyo unten seino hyoka

    Energy Technology Data Exchange (ETDEWEB)

    Kihara, M.; Kato, F.; Matsuura, K. [Nissan Motor Co. Ltd., Tokyo (Japan)

    1999-06-01

    Outlined herein are vehicle dynamic performance (operability, stability, ride comfort, etc) evaluation based on senses. The lower senses are the primary senses directly felt by the five senses. However, the evaluation described here is based on the complex senses which are excited by the primary senses and are difficult to directly measure. The analysis by the basic mechanical characteristics (e.g., primary senses, pitching and rolling) is necessary. It is also necessary to set and develop the primary and quasi-primary senses which constitute the complex senses (e.g., relaxed feeling), for which drivers' opinions should be collected. Roles, necessary ability, etc of drivers are listed up. In the planning stage, the company's cars are compared with a number of reference cars produced by the other makers by the evaluations based on the senses. The characteristics are comprehensively evaluated by, e.g., driving cars on special modes for specific test objectives and classifying the overall characteristics into components. Cars are driven accurately and smoothly, to reproduce the phenomena concerned. The overall evaluations are attempted, based on automotive engineering knowledge and evaluation experiences. (NEDO)

  10. Experimental and Numerical Investigation of Reduced Gravity Fluid Slosh Dynamics for the Characterization of Cryogenic Launch and Space Vehicle Propellants

    Science.gov (United States)

    Walls, Laurie K.; Kirk, Daniel; deLuis, Kavier; Haberbusch, Mark S.

    2011-01-01

    As space programs increasingly investigate various options for long duration space missions the accurate prediction of propellant behavior over long periods of time in microgravity environment has become increasingly imperative. This has driven the development of a detailed, physics-based understanding of slosh behavior of cryogenic propellants over a range of conditions and environments that are relevant for rocket and space storage applications. Recent advancements in computational fluid dynamics (CFD) models and hardware capabilities have enabled the modeling of complex fluid behavior in microgravity environment. Historically, launch vehicles with moderate duration upper stage coast periods have contained very limited instrumentation to quantify propellant stratification and boil-off in these environments, thus the ability to benchmark these complex computational models is of great consequence. To benchmark enhanced CFD models, recent work focuses on establishing an extensive experimental database of liquid slosh under a wide range of relevant conditions. In addition, a mass gauging system specifically designed to provide high fidelity measurements for both liquid stratification and liquid/ullage position in a micro-gravity environment has been developed. This pUblication will summarize the various experimental programs established to produce this comprehensive database and unique flight measurement techniques.

  11. Studies of vehicle lane-changing dynamics and its effect on traffic efficiency, safety and environmental impact

    Science.gov (United States)

    Li, Xiang; Sun, Jian-Qiao

    2017-02-01

    Drivers often change lanes on the road to maintain desired speed and to avoid slow vehicles, pedestrians, obstacles and lane closure. Understanding the effect of lane-changing on the traffic is an important topic in designing optimal traffic control systems. This paper presents a comprehensive study of this topic. We review the theory of microscopic dynamic car-following models and the lane-changing models, propose additional lane-changing rules to deal with moving bottleneck and lane reduction, and investigate the effects of lane-changing on the traffic efficiency, traffic safety and fuel consumption as a function of different variables including the distance of the emergency sign ahead of the lane closure, speed limit, traffic density, etc. Extensive simulations of the traffic system have been carried out in different scenarios. A number of important findings of the effect of various factors on the traffic are reported. These findings provide guidance on the traffic management and are important to the designers and engineers of modern highway or inner city roads to achieve high traffic efficiency and safety with minimum environmental impact.

  12. A Mixed Logical Dynamical-Model Predictive Control (MLD-MPC Energy Management Control Strategy for Plug-in Hybrid Electric Vehicles (PHEVs

    Directory of Open Access Journals (Sweden)

    Jing Lian

    2017-01-01

    Full Text Available Plug-in hybrid electric vehicles (PHEVs can be considered as a hybrid system (HS which includes the continuous state variable, discrete event, and operation constraint. Thus, a model predictive control (MPC strategy for PHEVs based on the mixed logical dynamical (MLD model and short-term vehicle speed prediction is proposed in this paper. Firstly, the mathematical model of the controlled PHEV is set-up to evaluate the energy consumption using the linearized models of core power components. Then, based on the recognition of driving intention and the past vehicle speed data, a nonlinear auto-regressive (NAR neural network structure is designed to predict the vehicle speed for known driving profiles of city buses and the predicted vehicle speed is used to calculate the total required torque. Next, a MLD model is established with appropriate constraints for six possible driving modes. By solving the objective function with the Mixed Integer Linear Programming (MILP algorithm, the optimal motor torque and the corresponding driving mode sequence within the speed prediction horizon can be obtained. Finally, the proposed energy control strategy shows substantial improvement in fuel economy in the simulation results.

  13. Conformational analysis of processivity clamps in solution demonstrates that tertiary structure does not correlate with protein dynamics.

    Science.gov (United States)

    Fang, Jing; Nevin, Philip; Kairys, Visvaldas; Venclovas, Ceslovas; Engen, John R; Beuning, Penny J

    2014-04-08

    The relationship between protein sequence, structure, and dynamics has been elusive. Here, we report a comprehensive analysis using an in-solution experimental approach to study how the conservation of tertiary structure correlates with protein dynamics. Hydrogen exchange measurements of eight processivity clamp proteins from different species revealed that, despite highly similar three-dimensional structures, clamp proteins display a wide range of dynamic behavior. Differences were apparent both for structurally similar domains within proteins and for corresponding domains of different proteins. Several of the clamps contained regions that underwent local unfolding with different half-lives. We also observed a conserved pattern of alternating dynamics of the α helices lining the inner pore of the clamps as well as a correlation between dynamics and the number of salt bridges in these α helices. Our observations reveal that tertiary structure and dynamics are not directly correlated and that primary structure plays an important role in dynamics.

  14. Description/demonstration of BIODYN-80. A software package for evaluating the transmissibility between vehicle vibration and motions of hands (in controls), limbs, head and eyes

    Science.gov (United States)

    Riedel, S. A.; Jex, H. R.; Magdaleno, R. E.

    1982-01-01

    A user-oriented program for exercising the 1980 verson of the biodynamic model BIODYN-80 is described. The user inputs (modifies) some 80-100 variables describing the assumed posture, interface characteristics (e.g., stick "feel" properties), and vestibular characteristics. The computer calculates the transfer functions between vibration input and various selected outputs of interest to the user. Another option is to output the operator's torso-limb-neuromuscular loop transmissibilities as seen at the stick, as required for the PIVIB computer program for computing tracking performance effects of vibration. Applications to some current problems are demonstrated.

  15. Distributed vehicle dynamics control with time-triggered architecture by means of the Bosch concept VDM; Verteilte Fahrdynamikregelung mit zeitgesteuerter Architektur am Beispiel des Bosch-Konzeptes VDM

    Energy Technology Data Exchange (ETDEWEB)

    Albert, A.; Traechtler, A. [Robert Bosch GmbH, Schwieberdingen (Germany)

    2004-07-01

    By means of the Bosch concept 'vehicle dynamics management' (VDM), which coordinates vehicle dynamics functions by control of active chassis systems, a study is carried out towards the migration from an event-triggered (CAN) to a time-triggered (TTCAN and FlexRay) communication. The main targets of the study are the illustration of a possible migration concept on the one hand, and the investigation of the impacts of time-triggered architectures with regard to the time behaviour, the development process, the operating system, the functional software and the control design on the other hand. The article presents first results and some thoughts on problems which arise from a holistic view on the design of time-triggered architectures. (orig.)

  16. Frontal crash simulation of vehicles against lighting columns using FEM

    Directory of Open Access Journals (Sweden)

    Yehia A. Abdel-Nasser

    2013-09-01

    Full Text Available There are many severe and fatal crashes that result from vehicles colliding with street columns such as lighting columns. These cause extremely high impact forces and deformation on the frontal area of the car. The objective of the study is to demonstrate the frontal crash simulation of vehicle against lighting columns to examine injury risk and potential of safety. In particular, various FE models are used to perform contact–impact nonlinear dynamic analysis of lighting columns with vehicle. In this paper Abaqus explicit code is used to numerically simulate the crash of the vehicle with present columns and other lighting columns fabricated from a new suggested material. The acceleration, contact force and deformed energy at the frontal region of the vehicle are traced. It is found that the lighting columns with new suggested material have impact properties to decelerate the vehicle and absorb higher energy during impact.

  17. A mechanical brake hardware-in-the-loop simulation of a railway vehicle that accounts for hysteresis and pneumatic cylinder dynamics

    OpenAIRE

    Dong-Chan Lee; Chul-Goo Kang

    2015-01-01

    A brake hardware-in-the-loop simulation system for a railway vehicle provides an effective platform for testing the braking performance under various dangerous braking conditions. However, in general, four-brake calipers are required to implement a mechanical brake system for one car. In this article, we implement a brake hardware-in-the-loop simulation system only with one brake caliper and three air tanks accounting for hysteresis and pneumatic cylinder dynamics, ultimately saving installat...

  18. A dynamic programming heuristic for the vehicle routing problem with time windows and European Community social legislation

    NARCIS (Netherlands)

    Kok, A.L.; Meyer, C.M.; Kopfer, H.; Schutten, J.M.J.

    2010-01-01

    In practice, apart from the problem of vehicle routing, schedulers also face the problem of finding feasible driver schedules complying with complex restrictions on drivers' driving and working hours. To address this complex interdependent problem of vehicle routing and break scheduling, we propose

  19. Dynamic metabolism modelling of urban water services--demonstrating effectiveness as a decision-support tool for Oslo, Norway.

    Science.gov (United States)

    Venkatesh, G; Sægrov, Sveinung; Brattebø, Helge

    2014-09-15

    Urban water services are challenged from many perspectives and different stakeholders demand performance improvements along economic, social and environmental dimensions of sustainability. In response, urban water utilities systematically give more attention to criteria such as water safety, climate change adaptation and mitigation, environmental life cycle assessment (LCA), total cost efficiency, and on how to improve their operations within the water-energy-carbon nexus. The authors of this paper collaborated in the development of a 'Dynamic Metabolism Model' (DMM). The model is developed for generic use in the sustainability assessment of urban water services, and it has been initially tested for the city of Oslo, Norway. The purpose has been to adopt a holistic systemic perspective to the analysis of metabolism and environmental impacts of resource flows in urban water and wastewater systems, in order to offer a tool for the examination of future strategies and intervention options in such systems. This paper describes the model and its application to the city of Oslo for the analysis time period 2013-2040. The external factors impacting decision-making and interventions are introduced along with realistic scenarios developed for the testing, after consultation with officials at the Oslo Water and Wastewater Works (Norway). Possible interventions that the utility intends to set in motion are defined and numerically interpreted for incorporation into the model, and changes in the indicator values over the time period are determined. This paper aims to demonstrate the effectiveness and usefulness of the DMM, as a decision-support tool for water-wastewater utilities. The scenarios considered and interventions identified do not include all possible scenarios and interventions that can be relevant for water-wastewater utilities. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. A Space-Time Network-Based Modeling Framework for Dynamic Unmanned Aerial Vehicle Routing in Traffic Incident Monitoring Applications.

    Science.gov (United States)

    Zhang, Jisheng; Jia, Limin; Niu, Shuyun; Zhang, Fan; Tong, Lu; Zhou, Xuesong

    2015-06-12

    It is essential for transportation management centers to equip and manage a network of fixed and mobile sensors in order to quickly detect traffic incidents and further monitor the related impact areas, especially for high-impact accidents with dramatic traffic congestion propagation. As emerging small Unmanned Aerial Vehicles (UAVs) start to have a more flexible regulation environment, it is critically important to fully explore the potential for of using UAVs for monitoring recurring and non-recurring traffic conditions and special events on transportation networks. This paper presents a space-time network- based modeling framework for integrated fixed and mobile sensor networks, in order to provide a rapid and systematic road traffic monitoring mechanism. By constructing a discretized space-time network to characterize not only the speed for UAVs but also the time-sensitive impact areas of traffic congestion, we formulate the problem as a linear integer programming model to minimize the detection delay cost and operational cost, subject to feasible flying route constraints. A Lagrangian relaxation solution framework is developed to decompose the original complex problem into a series of computationally efficient time-dependent and least cost path finding sub-problems. Several examples are used to demonstrate the results of proposed models in UAVs' route planning for small and medium-scale networks.