Preliminary development of a wing in ground effect vehicle

Science.gov (United States)

Abidin, Razali; Ahamat, Mohamad Asmidzam; Ahmad, Tarmizi; Saad, Mohd Rasdan; Hafizi, Ezzat

2018-02-01

Wing in ground vehicle is one of the mode of transportation that allows high speed movement over water by travelling few meters above the water level. Through this manouver strategy, a cushion of compressed air exists between the wing in ground vehicle wings and water. This significantly increase the lift force, thus reducing the necessity in having a long wing span. Our project deals with the development of wing in ground vehicle with the capability of transporting four people. The total weight of this wing in ground vehicle was estimated at 5.4 kN to enable the prediction on required wing area, minimum takeoff velocity, drag force and engine power requirement. The required takeoff velocity is decreases as the lift coefficient increases, and our current mathematical model shows the takeoff velocity at 50 m/s avoid the significant increase in lift coefficient for the wing area of 5 m2. At the velocity of 50 m/s, the drag force created by this wing in ground vehicle is well below 1 kN, which required a 100-120 kW of engine power if the propeller has the efficiency of 0.7. Assessment on the stresses and deflection of the hull structural indicate the capability of plywood to withstand the expected load. However, excessive deflection was expected in the rear section which requires a minor structural modification. In the near future, we expect that the wind tunnel tests of this wing in ground vehicle model would enable more definite prediction on the important parameters related to its performance.

Ground Vehicle System Integration (GVSI) and Design Optimization Model

National Research Council Canada - National Science Library

Horton, William

1996-01-01

This report documents the Ground Vehicle System Integration (GVSI) and Design Optimization Model GVSI is a top-level analysis tool designed to support engineering tradeoff studies and vehicle design optimization efforts...

Quantifying the Effects of Idle-Stop Systems on Fuel Economy in Light-Duty Passenger Vehicles

Energy Technology Data Exchange (ETDEWEB)

Jeff Wishart; Matthew Shirk

2012-12-01

Vehicles equipped with idle-stop (IS) systems are capable of engine shut down when the vehicle is stopped and rapid engine re-start for the vehicle launch. This capability reduces fuel consumption and emissions during periods when the engine is not being utilized to provide propulsion or to power accessories. IS systems are a low-cost and fast-growing technology in the industry-wide pursuit of increased vehicle efficiency, possibly becoming standard features in European vehicles in the near future. In contrast, currently there are only three non-hybrid vehicle models for sale in North America with IS systems and these models are distinctly low-volume models. As part of the United States Department of Energy’s Advanced Vehicle Testing Activity, ECOtality North America has tested the real-world effect of IS systems on fuel consumption in three vehicle models imported from Europe. These vehicles were chosen to represent three types of systems: (1) spark ignition with 12-V belt alternator starter; (2) compression ignition with 12-V belt alternator starter; and (3) direct-injection spark ignition, with 12-V belt alternator starter/combustion restart. The vehicles have undergone both dynamometer and on-road testing; the test results show somewhat conflicting data. The laboratory data and the portion of the on-road data in which driving is conducted on a prescribed route with trained drivers produced significant fuel economy improvement. However, the fleet data do not corroborate improvement, even though the data show significant engine-off time. It is possible that the effects of the varying driving styles and routes in the fleet testing overshadowed the fuel economy improvements. More testing with the same driver over routes that are similar with the IS system-enabled and disabled is recommended. There is anecdotal evidence that current Environmental Protection Agency fuel economy test procedures do not capture the fuel economy gains that IS systems produce in real

Refueling Stop Activity Detection and Gas Station Extraction Using Crowdsourcing Vehicle Trajectory Data

Directory of Open Access Journals (Sweden)

YANG Wei

2017-07-01

Full Text Available In view of the deficiencies of current surveying methods of gas station, an approach is proposed to extract gas station from vehicle traces. Firstly, the spatial-temporal characteristics of individual and collective refueling behavior of trajectory is analyzed from aspects of movement features and geometric patterns. Secondly, based on Stop/Move model, the velocity sequence linear clustering algorithm is proposed to extract refueling stop tracks. Finally, using the methods including Delaunay triangulation, Fourier shape recognition and semantic constraints to identify and extract gas station. An experiment using 7 days taxi GPS traces in Beijing verified the novel method. The experimental results of 482 gas stations are extracted and the correct rate achieves to 93.1%.

The 15th Annual Intelligent Ground Vehicle Competition: Intelligent Ground Robots Created by Intelligent Students

National Research Council Canada - National Science Library

Theisen, Bernard L

2007-01-01

The Intelligent Ground Vehicle Competition (IGVC) is one of three, unmanned systems, student competitions that were founded by the Association for Unmanned Vehicle Systems International (AUVSI) in the 1990s...

Modeling ground vehicle acoustic signatures for analysis and synthesis

International Nuclear Information System (INIS)

Haschke, G.; Stanfield, R.

1995-01-01

Security and weapon systems use acoustic sensor signals to classify and identify moving ground vehicles. Developing robust signal processing algorithms for this is expensive, particularly in presence of acoustic clutter or countermeasures. This paper proposes a parametric ground vehicle acoustic signature model to aid the system designer in understanding which signature features are important, developing corresponding feature extraction algorithms and generating low-cost, high-fidelity synthetic signatures for testing. The authors have proposed computer-generated acoustic signatures of armored, tracked ground vehicles to deceive acoustic-sensored smart munitions. They have developed quantitative measures of how accurately a synthetic acoustic signature matches those produced by actual vehicles. This paper describes parameters of the model used to generate these synthetic signatures and suggests methods for extracting these parameters from signatures of valid vehicle encounters. The model incorporates wide-bandwidth and narrow- bandwidth components that are modulated in a pseudo-random fashion to mimic the time dynamics of valid vehicle signatures. Narrow- bandwidth feature extraction techniques estimate frequency, amplitude and phase information contained in a single set of narrow frequency- band harmonics. Wide-bandwidth feature extraction techniques estimate parameters of a correlated-noise-floor model. Finally, the authors propose a method of modeling the time dynamics of the harmonic amplitudes as a means adding necessary time-varying features to the narrow-bandwidth signal components. The authors present results of applying this modeling technique to acoustic signatures recorded during encounters with one armored, tracked vehicle. Similar modeling techniques can be applied to security systems

Learning Mobility: Adaptive Control Algorithms for the Novel Unmanned Ground Vehicle (NUGV)

National Research Council Canada - National Science Library

Blackburn, Mike

2003-01-01

Mobility is a serious limiting factor in the usefulness of unmanned ground vehicles, This paper contains a description of our approach to develop control algorithms for the Novel Unmanned Ground Vehicle (NUGV...

Piecewise affine control for fast unmanned ground vehicles

OpenAIRE

Benine Neto , André; Grand , Christophe

2012-01-01

International audience; Unmanned ground vehicles (UGV) may experience skidding when moving at high speeds, and therefore have its safety jeopardized. For this reason the nonlinear dynamics of lateral tire forces must be taken into account into the design of steering controllers for autonomous vehicles. This paper presents the design of a state feedback piecewise affine controller applied to an UGV to coordinate the steering and torque distribution inputs in order to reduce vehicle skidding on...

An SINS/GNSS Ground Vehicle Gravimetry Test Based on SGA-WZ02

Directory of Open Access Journals (Sweden)

Ruihang Yu

2015-09-01

Full Text Available In March 2015, a ground vehicle gravimetry test was implemented in eastern Changsha to assess the repeatability and accuracy of ground vehicle SINS/GNSS gravimeter—SGA-WZ02. The gravity system developed by NUDT consisted of a Strapdown Inertial Navigation System (SINS, a Global Navigation Satellite System (GNSS remote station on test vehicle, a GNSS static master station on the ground, and a data logging subsystem. A south-north profile of 35 km along the highway in eastern Changsha was chosen and four repeated available measure lines were obtained. The average speed of a vehicle is 40 km/h. To assess the external ground gravity disturbances, precise ground gravity data was built by CG-5 precise gravimeter as the reference. Under relative smooth conditions, internal accuracy among repeated lines shows an average agreement at the level of 1.86 mGal for half wavelengths about 1.1 km, and 1.22 mGal for 1.7 km. The root-mean-square (RMS of difference between calculated gravity data and reference data is about 2.27 mGal/1.1 km, and 1.74 mGal/1.7 km. Not all of the noises caused by vehicle itself and experiments environments were eliminated in the primary results. By means of selecting reasonable filters and improving the GNSS observation conditions, further developments in ground vehicle gravimetry are promising.

Research of the stopping distance for different road conditions

Directory of Open Access Journals (Sweden)

Daniel LYUBENOV

2011-01-01

Full Text Available In this paper a modern method for determination of stopping distance is represented. Application of the non-contact VBOX 3i 100Hz GPS Data Logger speed and distance measurement system is represented. A description of the total stopping distance of vehicle main components - driver reaction time, vehicle reaction time and vehicle braking capability has been made. Research of the total stopping distance of a vehicle for different road conditions has been made. The results for the stopping distance can be very useful in the expert practice.

The Effect of Predicted Vehicle Displacement on Ground Crew Task Performance and Hardware Design

Science.gov (United States)

Atencio, Laura Ashley; Reynolds, David W.

2011-01-01

NASA continues to explore new launch vehicle concepts that will carry astronauts to low- Earth orbit to replace the soon-to-be retired Space Transportation System (STS) shuttle. A tall vertically stacked launch vehicle (> or =300 ft) is exposed to the natural environment while positioned on the launch pad. Varying directional winds and vortex shedding cause the vehicle to sway in an oscillating motion. Ground crews working high on the tower and inside the vehicle during launch preparations will be subjected to this motion while conducting critical closeout tasks such as mating fluid and electrical connectors and carrying heavy objects. NASA has not experienced performing these tasks in such environments since the Saturn V, which was serviced from a movable (but rigid) service structure; commercial launchers are likewise attended by a service structure that moves away from the vehicle for launch. There is concern that vehicle displacement may hinder ground crew operations, impact the ground system designs, and ultimately affect launch availability. The vehicle sway assessment objective is to replicate predicted frequencies and displacements of these tall vehicles, examine typical ground crew tasks, and provide insight into potential vehicle design considerations and ground crew performance guidelines. This paper outlines the methodology, configurations, and motion testing performed while conducting the vehicle displacement assessment that will be used as a Technical Memorandum for future vertically stacked vehicle designs.

Vehicle barrier systems

International Nuclear Information System (INIS)

Sena, P.A.

1986-01-01

The ground vehicle is one of the most effective tools available to an adversary force. Vehicles can be used to penetrate many types of perimeter barriers, transport equipment and personnel rapidly over long distances, and deliver large amounts of explosives directly to facilities in suicide missions. The function of a vehicle barrier system is to detain or disable a defined threat vehicle at a selected distance from a protected facility. Numerous facilities are installing, or planning to install, vehicle barrier systems and many of these facilities are requesting guidance to do so adequately. Therefore, vehicle barriers are being evaluated to determine their stopping capabilities so that systems can be designed that are both balanced and capable of providing a desired degree of protection. Equally important, many of the considerations that should be taken into account when establishing a vehicle barrier system have been identified. These considerations which pertain to site preparation, barrier selection, system integration and operation, and vehicle/barrier interaction, are discussed in this paper

Space imaging infrared optical guidance for autonomous ground vehicle

Science.gov (United States)

Akiyama, Akira; Kobayashi, Nobuaki; Mutoh, Eiichiro; Kumagai, Hideo; Yamada, Hirofumi; Ishii, Hiromitsu

2008-08-01

We have developed the Space Imaging Infrared Optical Guidance for Autonomous Ground Vehicle based on the uncooled infrared camera and focusing technique to detect the objects to be evaded and to set the drive path. For this purpose we made servomotor drive system to control the focus function of the infrared camera lens. To determine the best focus position we use the auto focus image processing of Daubechies wavelet transform technique with 4 terms. From the determined best focus position we transformed it to the distance of the object. We made the aluminum frame ground vehicle to mount the auto focus infrared unit. Its size is 900mm long and 800mm wide. This vehicle mounted Ackerman front steering system and the rear motor drive system. To confirm the guidance ability of the Space Imaging Infrared Optical Guidance for Autonomous Ground Vehicle we had the experiments for the detection ability of the infrared auto focus unit to the actual car on the road and the roadside wall. As a result the auto focus image processing based on the Daubechies wavelet transform technique detects the best focus image clearly and give the depth of the object from the infrared camera unit.

Teleoperated Visual Inspection and Surveillance with Unmanned Ground and Aerial Vehicles

Directory of Open Access Journals (Sweden)

Viatcheslav Tretyakov

2008-11-01

Full Text Available This paper introduces our robotic system named UGAV (Unmanned Ground-Air Vehicle consisting of two semi-autonomous robot platforms, an Unmanned Ground Vehicle (UGV and an Unmanned Aerial Vehicles (UAV. The paper focuses on three topics of the inspection with the combined UGV and UAV: (A teleoperated control by means of cell or smart phones with a new concept of automatic configuration of the smart phone based on a RKI-XML description of the vehicles control capabilities, (B the camera and vision system with the focus to real time feature extraction e.g. for the tracking of the UAV and (C the architecture and hardware of the UAV

Aeroelastic Ground Wind Loads Analysis Tool for Launch Vehicles

Science.gov (United States)

Ivanco, Thomas G.

2016-01-01

Launch vehicles are exposed to ground winds during rollout and on the launch pad that can induce static and dynamic loads. Of particular concern are the dynamic loads caused by vortex shedding from nearly-cylindrical structures. When the frequency of vortex shedding nears that of a lowly-damped structural mode, the dynamic loads can be more than an order of magnitude greater than mean drag loads. Accurately predicting vehicle response to vortex shedding during the design and analysis cycles is difficult and typically exceeds the practical capabilities of modern computational fluid dynamics codes. Therefore, mitigating the ground wind loads risk typically requires wind-tunnel tests of dynamically-scaled models that are time consuming and expensive to conduct. In recent years, NASA has developed a ground wind loads analysis tool for launch vehicles to fill this analytical capability gap in order to provide predictions for prelaunch static and dynamic loads. This paper includes a background of the ground wind loads problem and the current state-of-the-art. It then discusses the history and significance of the analysis tool and the methodology used to develop it. Finally, results of the analysis tool are compared to wind-tunnel and full-scale data of various geometries and Reynolds numbers.

Assessing the ground vibrations produced by a heavy vehicle traversing a traffic obstacle.

Science.gov (United States)

Ducarne, Loïc; Ainalis, Daniel; Kouroussis, Georges

2018-01-15

Despite advancements in alternative transport networks, road transport remains the dominant mode in many modern and developing countries. The ground-borne motions produced by the passage of a heavy vehicle over a geometric obstacle (e.g. speed hump, train tracks) pose a fundamental problem in transport annoyance in urban areas. In order to predict the ground vibrations generated by the passage of a heavy vehicle over a geometric obstacle, a two-step numerical model is developed. The first step involves simulating the dynamic loads generated by the heavy vehicle using a multibody approach, which includes the tyre-obstacle-ground interaction. The second step involves the simulation of the ground wave propagation using a three dimensional finite element model. The simulation is able to be decoupled due to the large difference in stiffness between the vehicle's tyres and the road. First, the two-step model is validated using an experimental case study available in the literature. A sensitivity analysis is then presented, examining the influence of various factors on the generated ground vibrations. Factors investigated include obstacle shape, obstacle dimensions, vehicle speed, and tyre stiffness. The developed model can be used as a tool in the early planning stages to predict the ground vibrations generated by the passage of a heavy vehicle over an obstacle in urban areas. Copyright © 2017 Elsevier B.V. All rights reserved.

Systems Engineering Approach To Ground Combat Vehicle Survivability In Urban Operations

Science.gov (United States)

2016-09-01

GROUND COMBAT VEHICLE SURVIVABILITY IN URBAN OPERATIONS 5. FUNDING NUMBERS N/A 6. AUTHOR(S) Luhai Wong 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS...distance of 100m in the model , which is reasonable due to the constrained nature of an urban environment. This thesis also uses the key parameters...ENGINEERING APPROACH TO GROUND COMBAT VEHICLE SURVIVABILITY IN URBAN OPERATIONS by Luhai Wong September 2016 Thesis Advisor: Christopher A

Cellular Automata Based Modeling for Evaluating Different Bus Stop Designs in China

Directory of Open Access Journals (Sweden)

Haoyang Ding

2015-01-01

Full Text Available A cellular automaton model is proposed to simulate mixed traffic flow composed of motor vehicles and bicycles near bus stops. Three typical types of bus stops which are common in China are considered in the model, including two types of curbside bus stops and one type of bus bay stops. Passenger transport capacity of three types of bus stops, which is applied to evaluate the bus stop design, is calculated based on the corresponding traffic flow rate. According to the simulation results, the flow rates of both motor vehicles and bicycles exhibit phase transition from free flow to the saturation one at the critical point. The results also show that the larger the interaction between motor vehicle and bicycle flow is near curbside bus stops, the more the value of saturated flows drops. Curbside bus stops are more suitable when the conflicts between two flows are small and the inflow rate of motor vehicles is low. On the contrary, bus bay stops should be applied due to their ability to reduce traffic conflicts. Findings of this study can provide useful suggestions on bus stop selection considering different inflow rate of motor vehicles and bicycles simultaneously.

Investigations into near-real-time surveying for geophysical data collection using an autonomous ground vehicle

Science.gov (United States)

Phelps, Geoffrey A.; Ippolito, C.; Lee, R.; Spritzer, R.; Yeh, Y.

2014-01-01

The U.S. Geological Survey and the National Aeronautics and Space Administration are cooperatively investigating the utility of unmanned vehicles for near-real-time autonomous surveys of geophysical data collection. Initially focused on unmanned ground vehicle collection of magnetic data, this cooperative effort has brought unmanned surveying, precision guidance, near-real-time communication, on-the-fly data processing, and near-real-time data interpretation into the realm of ground geophysical surveying, all of which offer advantages over current methods of manned collection of ground magnetic data. An unmanned ground vehicle mission has demonstrated that these vehicles can successfully complete missions to collect geophysical data, and add advantages in data collection, processing, and interpretation. We view the current experiment as an initial phase in further unmanned vehicle data-collection missions, including aerial surveying.

Wavelet-based ground vehicle recognition using acoustic signals

Science.gov (United States)

Choe, Howard C.; Karlsen, Robert E.; Gerhart, Grant R.; Meitzler, Thomas J.

1996-03-01

We present, in this paper, a wavelet-based acoustic signal analysis to remotely recognize military vehicles using their sound intercepted by acoustic sensors. Since expedited signal recognition is imperative in many military and industrial situations, we developed an algorithm that provides an automated, fast signal recognition once implemented in a real-time hardware system. This algorithm consists of wavelet preprocessing, feature extraction and compact signal representation, and a simple but effective statistical pattern matching. The current status of the algorithm does not require any training. The training is replaced by human selection of reference signals (e.g., squeak or engine exhaust sound) distinctive to each individual vehicle based on human perception. This allows a fast archiving of any new vehicle type in the database once the signal is collected. The wavelet preprocessing provides time-frequency multiresolution analysis using discrete wavelet transform (DWT). Within each resolution level, feature vectors are generated from statistical parameters and energy content of the wavelet coefficients. After applying our algorithm on the intercepted acoustic signals, the resultant feature vectors are compared with the reference vehicle feature vectors in the database using statistical pattern matching to determine the type of vehicle from where the signal originated. Certainly, statistical pattern matching can be replaced by an artificial neural network (ANN); however, the ANN would require training data sets and time to train the net. Unfortunately, this is not always possible for many real world situations, especially collecting data sets from unfriendly ground vehicles to train the ANN. Our methodology using wavelet preprocessing and statistical pattern matching provides robust acoustic signal recognition. We also present an example of vehicle recognition using acoustic signals collected from two different military ground vehicles. In this paper, we will

41 CFR 101-39.307 - Grounds for withdrawal of vehicle.

Science.gov (United States)

2010-07-01

... VEHICLES 39-INTERAGENCY FLEET MANAGEMENT SYSTEMS 39.3-Use and Care of GSA Interagency Fleet Management... 41 Public Contracts and Property Management 2 2010-07-01 2010-07-01 true Grounds for withdrawal of vehicle. 101-39.307 Section 101-39.307 Public Contracts and Property Management Federal Property...

Numerical Investigation of Aerodynamic Braking for a Ground Vehicle

Science.gov (United States)

Devanuri, Jaya Krishna

2018-06-01

The purpose of this article is to observe the effect of an air brake on the aerodynamics of a ground vehicle and also to study the influence of change in the parameters like the velocity of the vehicle, the angle of inclination, height, and position of the air brake on the aerodynamics of the vehicle body. The test subject used is an Ahmed body which is a generic 3D car body as it retains all the aerodynamic characteristics of a ground vehicle. Numerical investigation has been carried out by RNG k-ɛ turbulence model. Results are presented in terms of streamlines and drag coefficient to understand the influence of pertinent parameters on flow physics. It is found that with the use of an air brake, though the drag coefficient remains more or less constant with velocity, it increases with the increase in height and angle of inclination of the air brake. But the effect of position of air brake on the coefficient of drag is surprising since for certain heights of the air brake the drag coefficient is maximum at the foremost point and as the air brake moves towards the rear it is first observed to decrease and then increase. It is also observed that with the increase in height of the air brake the drag coefficient monotonically decreases as the position of the air brake is moved towards the rear. Taguchi method has been employed with L16 orthogonal array to obtain the optimal configuration for the air brake. For each of the selected parameters, four different levels have been chosen to obtain the maximum drag coefficient value. The study could provide an invaluable database for the optimal design of an airbrake for a ground vehicle.

X-43A Vehicle During Ground Testing

Science.gov (United States)

1999-01-01

The X-43A Hypersonic Experimental Vehicle, or 'Hyper-X' is seen here undergoing ground testing at NASA's Dryden Flight Research Center, Edwards, California in December 1999. The X-43A was developed to research a dual-mode ramjet/scramjet propulsion system at speeds from Mach 7 up to Mach 10 (7 to 10 times the speed of sound, which varies with temperature and altitude). Hyper-X, the flight vehicle for which is designated as X-43A, is an experimental flight-research program seeking to demonstrate airframe-integrated, 'air-breathing' engine technologies that promise to increase payload capacity for future vehicles, including hypersonic aircraft (faster than Mach 5) and reusable space launchers. This multiyear program is currently underway at NASA Dryden Flight Research Center, Edwards, California. The Hyper-X schedule calls for its first flight later this year (2000). Hyper-X is a joint program, with Dryden sharing responsibility with NASA's Langley Research Center, Hampton, Virginia. Dryden's primary role is to fly three unpiloted X-43A research vehicles to validate engine technologies and hypersonic design tools as well as the hypersonic test facility at Langley. Langley manages the program and leads the technology development effort. The Hyper-X Program seeks to significantly expand the speed boundaries of air-breathing propulsion by being the first aircraft to demonstrate an airframe-integrated, scramjet-powered free flight. Scramjets (supersonic-combustion ramjets) are ramjet engines in which the airflow through the whole engine remains supersonic. Scramjet technology is challenging because only limited testing can be performed in ground facilities. Long duration, full-scale testing requires flight research. Scramjet engines are air-breathing, capturing their oxygen from the atmosphere. Current spacecraft, such as the Space Shuttle, are rocket powered, so they must carry both fuel and oxygen for propulsion. Scramjet technology-based vehicles need to carry only

Magneto-rheological suspensions for improving ground vehicle's ride comfort, stability, and handling

Science.gov (United States)

Ahmadian, Mehdi

2017-10-01

A state-of-the-art discussion on the applications of magneto-rheological (MR) suspensions for improving ride comfort, handling, and stability in ground vehicles is discussed for both road and rail applications. A historical perspective on the discovery and engineering development of MR fluids is presented, followed by some of the common methods for modelling their non-Newtonian behaviour. The common modes of the MR fluids are discussed, along with the application of the fluid in valve mode for ground vehicles' dampers (or shock absorbers). The applications span across nearly all road vehicles, including automobiles, trains, semi-trucks, motorcycles, and even bicycles. For each type of vehicle, the results of some of the past studies is presented briefly, with reference to the originating study. It is discussed that Past experimental and modelling studies have indicated that MR suspensions provide clear advantages for ground vehicles that far surpasses the performance of passive suspension. For rail vehicles, the primary advantage is in terms of increasing the speed at which the onset of hunting occurs, whereas for road vehicles - mainly automobiles - the performance improvements are in terms of a better balance between vehicle ride, handling, and stability. To further elaborate on this point, a single-suspension model is used to develop an index-based approach for studying the compromise that is offered by vehicle suspensions, using the H2 optimisation approach. Evaluating three indices based on the sprung-mass acceleration, suspension rattlespace, and tyre deflection, it is clearly demonstrated that MR suspensions significantly improve road vehicle's ride comfort, stability, and handling in comparison with passive suspensions. For rail vehicles, the simulation results indicate that using MR suspensions with an on-off switching control can increase the speed at which the on-set of hunting occurs by as much as 50% to more than 300%.

Unmanned Ground Vehicle Perception Using Thermal Infrared Cameras

Science.gov (United States)

Rankin, Arturo; Huertas, Andres; Matthies, Larry; Bajracharya, Max; Assad, Christopher; Brennan, Shane; Bellut, Paolo; Sherwin, Gary

2011-01-01

TIR cameras can be used for day/night Unmanned Ground Vehicle (UGV) autonomous navigation when stealth is required. The quality of uncooled TIR cameras has significantly improved over the last decade, making them a viable option at low speed Limiting factors for stereo ranging with uncooled LWIR cameras are image blur and low texture scenes TIR perception capabilities JPL has explored includes: (1) single and dual band TIR terrain classification (2) obstacle detection (pedestrian, vehicle, tree trunks, ditches, and water) (3) perception thru obscurants

A study on the nondestructive test optimum design for a ground tracked combat vehicle

Energy Technology Data Exchange (ETDEWEB)

Kim Byeong Ho; Seo, Jae Hyun; Gil, Hyeon Jun [Defence Agency for Technology and Quality, Seoul (Korea, Republic of); Kim, Seon Hyeong [Hanwha Techwin Co.,Ltd., Changwon (Korea, Republic of); Seo, Sang Chul [Changwon National University, Changwon (Korea, Republic of)

2015-10-15

In this study, a nondestructive test (NDT) is performed to inspect the optimal design of a ground tracked combat vehicle for self-propelled artillery, tank, and armored vehicles. The minimum qualification required for personnel performing the NDT of a ground tracked combat vehicle was initially established in US military standards, and then applied to the Korean defense specifications to develop a ground tracked combat vehicle. However, the qualification standards of an NDT inspector have been integrated into NAS410 through the military and commercial specifications unification project that were applied in the existing aerospace/defense industry public standard. The design method for this study was verified by applying the optimal design to the liquid penetrant testing Al forging used in self-propelled artillery. This confirmed the reliability and soundness of the product.

Zero Rare-Earth Magnet Integrated Starter-Generator Development for Military Vehicle Applications

Science.gov (United States)

2013-08-14

platform. – Support of on-board hybrid electric features such as regenerative braking , torque assist and stop-start operation. 14 August 2013 4...13. SUPPLEMENTARY NOTES GROUND VEHICLE SYSTEMS ENGINEERING AND TECHNOLOGY SYMPOSIUM (GVSETS), SET FOR AUG. 21-22, 2013 14. ABSTRACT Briefing Charts

Mesh Optimization for Ground Vehicle Aerodynamics

OpenAIRE

Adrian Gaylard; Essam F Abo-Serie; Nor Elyana Ahmad

2010-01-01

Mesh optimization strategy for estimating accurate drag of a ground vehicle is proposed based on examining the effect of different mesh parameters.  The optimized mesh parameters were selected using design of experiment (DOE) method to be able to work in a...

Ground control station software design for micro aerial vehicles

Science.gov (United States)

Walendziuk, Wojciech; Oldziej, Daniel; Binczyk, Dawid Przemyslaw; Slowik, Maciej

2017-08-01

This article describes the process of designing the equipment part and the software of a ground control station used for configuring and operating micro unmanned aerial vehicles (UAV). All the works were conducted on a quadrocopter model being a commonly accessible commercial construction. This article contains a characteristics of the research object, the basics of operating the micro aerial vehicles (MAV) and presents components of the ground control station model. It also describes the communication standards for the purpose of building a model of the station. Further part of the work concerns the software of the product - the GIMSO application (Generally Interactive Station for Mobile Objects), which enables the user to manage the actions and communication and control processes from the UAV. The process of creating the software and the field tests of a station model are also presented in the article.

Deployment of Shaped Charges by a Semi-Autonomous Ground Vehicle

National Research Council Canada - National Science Library

Herkamp, John F

2007-01-01

.... BigFoot incorporates improved communication range over previous Autonomous Ground Vehicles and an updated user interface that includes controls for the arm and camera by interfacing multiple microprocessor...

The 15th Annual Intelligent Ground Vehicle Competition: Intelligent Ground Robots Created by Intelligent Students

National Research Council Canada - National Science Library

Theisen, Bernard L

2007-01-01

..., and mobile platform fundamentals to design and build an unmanned system. Teams from around the world focus on developing a suite of dual-use technologies to equip ground vehicles of the future with intelligent driving capabilities...

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.

A usage-centered evaluation methodology for unmanned ground vehicles

NARCIS (Netherlands)

Diggelen, J. van; Looije, R.; Mioch, T.; Neerincx, M.A.; Smets, N.J.J.M.

2012-01-01

This paper presents a usage-centered evaluation method to assess the capabilities of a particular Unmanned Ground Vehicle (UGV) for establishing the operational goals. The method includes a test battery consisting of basic tasks (e.g., slalom, funnel driving, object detection). Tests can be of

Exploring the mechanisms of vehicle front-end shape on pedestrian head injuries caused by ground impact.

Science.gov (United States)

Yin, Sha; Li, Jiani; Xu, Jun

2017-09-01

In pedestrian-vehicle accidents, pedestrians typically suffer from secondary impact with the ground after the primary contact with vehicles. However, information about the fundamental mechanism of pedestrian head injury from ground impact remains minimal, thereby hindering further improvement in pedestrian safety. This study addresses this issue by using multi-body modeling and computation to investigate the influence of vehicle front-end shape on pedestrian safety. Accordingly, a simulation matrix is constructed to vary bonnet leading-edge height, bonnet length, bonnet angle, and windshield angle. Subsequently, a set of 315 pedestrian-vehicle crash simulations are conducted using the multi-body simulation software MADYMO. Three vehicle velocities, i.e., 20, 30, and 40km/h, are set as the scenarios. Results show that the top governing factor is bonnet leading-edge height. The posture and head injury at the instant of head ground impact vary dramatically with increasing height because of the significant rise of the body bending point and the movement of the collision point. The bonnet angle is the second dominant factor that affects head-ground injury, followed by bonnet length and windshield angle. The results may elucidate one of the critical barriers to understanding head injury caused by ground impact and provide a solid theoretical guideline for considering pedestrian safety in vehicle design. Copyright © 2017 Elsevier Ltd. All rights reserved.

Integrated Vehicle Ground Vibration Testing of Manned Spacecraft: Historical Precedent

Science.gov (United States)

Lemke, Paul R.; Tuma, Margaret L.; Askins, Bruce R.

2008-01-01

For the first time in nearly 30 years, NASA is developing a new manned space flight launch system. The Ares I will carry crew and cargo to not only the International Space Station, but onward for the future exploration of the Moon and Mars. The Ares I control system and structural designs use complex computer models for their development. An Integrated Vehicle Ground Vibration Test (IVGVT) will validate the efficacy of these computer models. The IVGVT will reduce the technical risk of unexpected conditions that could place the vehicle or crew in jeopardy. The Ares Project Office's Flight and Integrated Test Office commissioned a study to determine how historical programs, such as Saturn and Space Shuttle, validated the structural dynamics of an integrated flight vehicle. The study methodology was to examine the historical record and seek out members of the engineering community who recall the development of historic manned launch vehicles. These records and interviews provided insight into the best practices and lessons learned from these historic development programs. The information that was gathered allowed the creation of timelines of the historic development programs. The timelines trace the programs from the development of test articles through test preparation, test operations, and test data reduction efforts. These timelines also demonstrate how the historical tests fit within their overall vehicle development programs. Finally, the study was able to quantify approximate staffing levels during historic development programs. Using this study, the Flight and Integrated Test Office was able to evaluate the Ares I Integrated Vehicle Ground Vibration Test schedule and workforce budgets in light of the historical precedents to determine if the test had schedule or cost risks associated with it.

Research on application of LADAR in ground vehicle recognition

Science.gov (United States)

Lan, Jinhui; Shen, Zhuoxun

2009-11-01

For the requirement of many practical applications in the field of military, the research of 3D target recognition is active. The representation that captures the salient attributes of a 3D target independent of the viewing angle will be especially useful to the automatic 3D target recognition system. This paper presents a new approach of image generation based on Laser Detection and Ranging (LADAR) data. Range image of target is obtained by transformation of point cloud. In order to extract features of different ground vehicle targets and to recognize targets, zernike moment properties of typical ground vehicle targets are researched in this paper. A technique of support vector machine is applied to the classification and recognition of target. The new method of image generation and feature representation has been applied to the outdoor experiments. Through outdoor experiments, it can be proven that the method of image generation is stability, the moments are effective to be used as features for recognition, and the LADAR can be applied to the field of 3D target recognition.

Estimating Hedonic Price Indices for Ground Vehicles

Science.gov (United States)

2015-06-01

I N S T I T U T E F O R D E F E N S E A N A L Y S E S Estimating Hedonic Price Indices for Ground Vehicles (Presentation) David M. Tate Stanley...gathering and maintaining the data needed , and completing and reviewing the collection of information. Send comments regarding this burden estimate or any...currently valid OMB control number. 1. REPORT DATE JUN 2015 2. REPORT TYPE 3. DATES COVERED 4. TITLE AND SUBTITLE Estimating Hedonic Price

The on-line electric vehicle wireless electric ground transportation systems

CERN Document Server

Cho, Dong

2017-01-01

This book details the design and technology of the on-line electric vehicle (OLEV) system and its enabling wireless power-transfer technology, the “shaped magnetic field in resonance” (SMFIR). The text shows how OLEV systems can achieve their three linked important goals: reduction of CO2 produced by ground transportation; improved energy efficiency of ground transportation; and contribution to the amelioration or prevention of climate change and global warming. SMFIR provides power to the OLEV by wireless transmission from underground cables using an alternating magnetic field and the reader learns how this is done. This cable network will in future be part of any local smart grid for energy supply and use thereby exploiting local and renewable energy generation to further its aims. In addition to the technical details involved with design and realization of a fleet of vehicles combined with extensive subsurface charging infrastructure, practical issues such as those involved with pedestrian safety are c...

The 21st annual intelligent ground vehicle competition: robotists for the future

Science.gov (United States)

Theisen, Bernard L.

2013-12-01

The Intelligent Ground Vehicle Competition (IGVC) is one of four, unmanned systems, student competitions that were founded by the Association for Unmanned Vehicle Systems International (AUVSI). The IGVC is a multidisciplinary exercise in product realization that challenges college engineering student teams to integrate advanced control theory, machine vision, vehicular electronics and mobile platform fundamentals to design and build an unmanned system. Teams from around the world focus on developing a suite of dual-use technologies to equip ground vehicles of the future with intelligent driving capabilities. Over the past 21 years, the competition has challenged undergraduate, graduate and Ph.D. students with real world applications in intelligent transportation systems, the military and manufacturing automation. To date, teams from over 80 universities and colleges have participated. This paper describes some of the applications of the technologies required by this competition and discusses the educational benefits. The primary goal of the IGVC is to advance engineering education in intelligent vehicles and related technologies. The employment and professional networking opportunities created for students and industrial sponsors through a series of technical events over the fourday competition are highlighted. Finally, an assessment of the competition based on participation is presented.

Application of parallelized software architecture to an autonomous ground vehicle

Science.gov (United States)

Shakya, Rahul; Wright, Adam; Shin, Young Ho; Momin, Orko; Petkovsek, Steven; Wortman, Paul; Gautam, Prasanna; Norton, Adam

2011-01-01

This paper presents improvements made to Q, an autonomous ground vehicle designed to participate in the Intelligent Ground Vehicle Competition (IGVC). For the 2010 IGVC, Q was upgraded with a new parallelized software architecture and a new vision processor. Improvements were made to the power system reducing the number of batteries required for operation from six to one. In previous years, a single state machine was used to execute the bulk of processing activities including sensor interfacing, data processing, path planning, navigation algorithms and motor control. This inefficient approach led to poor software performance and made it difficult to maintain or modify. For IGVC 2010, the team implemented a modular parallel architecture using the National Instruments (NI) LabVIEW programming language. The new architecture divides all the necessary tasks - motor control, navigation, sensor data collection, etc. into well-organized components that execute in parallel, providing considerable flexibility and facilitating efficient use of processing power. Computer vision is used to detect white lines on the ground and determine their location relative to the robot. With the new vision processor and some optimization of the image processing algorithm used last year, two frames can be acquired and processed in 70ms. With all these improvements, Q placed 2nd in the autonomous challenge.

Probabilistic Tracking and Trajectory Planning for Autonomous Ground Vehicles in Urban Environments

Science.gov (United States)

2016-03-05

Vehicles in Urban Environments The views, opinions and/or findings contained in this report are those of the author(s) and should not contrued as an...Pine Tree Road Ithaca, NY 14850 -2820 ABSTRACT Probabilistic Tracking and Trajectory Planning for Autonomous Ground Vehicles in Urban Environments...Probabilistic Anticipation for Autonomous Robots in Urban Environments, IEEE Transactions on Robotics, (04 2014): 0. doi: 10.1109/TRO.2013.2291620 Isaac

The influence of tyre contact patch and on the stopping distance of automotive vehicles

Science.gov (United States)

Selig, M.; Ball, A.; Ash, J.; Schmidt, K.

2012-05-01

This contribution presents the experimental tests results about the influence of the tyre contact patch on the stopping distance of automotive vehicles. The objective of the performed tests is the evaluation of the effect of tyre inflation pressure, hence the resulting tyre contact patch on the braking system and the brake distance. The conditions of the experiment are a dry and level road surface without steering inputs. To record scientific results, a brake robot system is used. The benefit of a robotic system is the elimination of the interfering variable driver, who is not able to apply the brake system at the same time with the same force. State-of-the-art data acquisition tools are used to log the data.

The influence of tyre contact patch and on the stopping distance of automotive vehicles

International Nuclear Information System (INIS)

Selig, M; Ball, A; Ash, J; Schmidt, K

2012-01-01

This contribution presents the experimental tests results about the influence of the tyre contact patch on the stopping distance of automotive vehicles. The objective of the performed tests is the evaluation of the effect of tyre inflation pressure, hence the resulting tyre contact patch on the braking system and the brake distance. The conditions of the experiment are a dry and level road surface without steering inputs. To record scientific results, a brake robot system is used. The benefit of a robotic system is the elimination of the interfering variable driver, who is not able to apply the brake system at the same time with the same force. State-of-the-art data acquisition tools are used to log the data.

INERTIAL TECHNOLOGIES IN SYSTEMS FOR STABILIZATION OF GROUND VEHICLES EQUIPMENT

Directory of Open Access Journals (Sweden)

Olha Sushchenko

2016-12-01

Full Text Available Purpose: The vibratory inertial technology is a recent modern inertial technology. It represents the most perspective approach to design of inertial sensors, which can be used in stabilization and tracking systems operated on vehicles of the wide class. The purpose of the research is to consider advantages of this technology in comparison with laser and fiber-optic ones. Operation of the inertial sensors on the ground vehicles requires some improvement of the Coriolis vibratory gyroscope with the goal to simplify information processing, increase reliability, and compensate bias. Methods: Improvement of the Coriolis vibratory gyroscope includes introducing of the phase detector and additional excitation unit. The possibility to use the improved Coriolis vibratory gyroscope in the stabilization systems operated on the ground vehicles is shown by means of analysis of gyroscope output signal. To prove efficiency of the Coriolis vibratory gyroscope in stabilization system the simulation technique is used. Results: The scheme of the improved Coriolis vibratory gyroscope including the phase detector and additional excitation unit is developed and analyzed. The way to compensate bias is determined. Simulation of the stabilization system with the improved Coriolis vibratory gyroscope is carried out. Expressions for the output signals of the improved Coriolis vibratory gyroscope are derived. The error of the output signal is estimated and the possibility to use the modified Coriolis vibratory gyroscope in stabilization systems is proved. The results of stabilization system simulation are given. Their analysis is carried out. Conclusions: The represented results prove efficiency of the proposed technical decisions. They can be useful for design of stabilization platform with instrumental equipment operated on moving vehicles of the wide class.

Parallel Hybrid Vehicle Optimal Storage System

Science.gov (United States)

Bloomfield, Aaron P.

2009-01-01

A paper reports the results of a Hybrid Diesel Vehicle Project focused on a parallel hybrid configuration suitable for diesel-powered, medium-sized, commercial vehicles commonly used for parcel delivery and shuttle buses, as the missions of these types of vehicles require frequent stops. During these stops, electric hybridization can effectively recover the vehicle's kinetic energy during the deceleration, store it onboard, and then use that energy to assist in the subsequent acceleration.

An investigation of drag reduction on box-shaped ground vehicles

Science.gov (United States)

Muirhead, V. U.

1976-01-01

A wind tunnel investigation was conducted to determine the reduction in drag which could be obtained by making various configuration changes to a box-shaped ground vehicle. Tests were conducted at yaw (relative wind) angles of 0, 5, 10, 20, and 30 degrees and Reynolds numbers of 300,000 to 850,000. The power required to overcome the aerodynamic drag was reduced by a maximum of 73% for a head wind for the best configuration relative to the smooth bottom box-shape, or 75% relative to the rough bottom box-shape. The reduction for a 20 MPH wind at 30 deg to the vehicle path was, respectively, 77% and 79%.

The 20th annual intelligent ground vehicle competition: building a generation of robotists

Science.gov (United States)

Theisen, Bernard L.; Kosinski, Andrew

2013-01-01

The Intelligent Ground Vehicle Competition (IGVC) is one of four, unmanned systems, student competitions that were founded by the Association for Unmanned Vehicle Systems International (AUVSI). The IGVC is a multidisciplinary exercise in product realization that challenges college engineering student teams to integrate advanced control theory, machine vision, vehicular electronics and mobile platform fundamentals to design and build an unmanned system. Teams from around the world focus on developing a suite of dual-use technologies to equip ground vehicles of the future with intelligent driving capabilities. Over the past 20 years, the competition has challenged undergraduate, graduate and Ph.D. students with real world applications in intelligent transportation systems, the military and manufacturing automation. To date, teams from over 80 universities and colleges have participated. This paper describes some of the applications of the technologies required by this competition and discusses the educational benefits. The primary goal of the IGVC is to advance engineering education in intelligent vehicles and related technologies. The employment and professional networking opportunities created for students and industrial sponsors through a series of technical events over the four-day competition are highlighted. Finally, an assessment of the competition based on participation is presented.

HYBRID VEHICLE CONTROL SYSTEM

Directory of Open Access Journals (Sweden)

V. Dvadnenko

2016-06-01

Full Text Available The hybrid vehicle control system includes a start–stop system for an internal combustion engine. The system works in a hybrid mode and normal vehicle operation. To simplify the start–stop system, there were user new possibilities of a hybrid car, which appeared after the conversion. Results of the circuit design of the proposed system of basic blocks are analyzed.

32 CFR 636.30 - Stopping, standing and parking.

Science.gov (United States)

2010-07-01

... ENFORCEMENT AND CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION (SPECIFIC INSTALLATIONS) Fort... which obstructs traffic. (g) No driver will stand or park a vehicle, whether occupied or not, except...) Within 20 feet upon the approach to any flashing signal, a stop sign, yield sign, or traffic control...

USABC Development of 12 Volt Battery for Start-Stop Application: Preprint

Energy Technology Data Exchange (ETDEWEB)

Tataria, H.; Gross, O.; Bae, C.; Cunningham, B.; Barnes, J. A.; Deppe, J.; Neubauer, J.

2015-02-01

Global automakers are accelerating the development of fuel efficient vehicles, as a part of meeting regional regulatory CO2 emissions requirements. The micro hybrid vehicles with auto start-stop functionality are considered economical solutions for the stringent European regulations. Flooded lead acid batteries were initially considered the most economical solution for idle-stop systems. However, the dynamic charge acceptance (DCA) at lower state-of-charge (SOC) was limiting the life of the batteries. While improved lead-acid batteries with AGM and VRLA features have improved battery longevity, they do not last the life of the vehicle. The United States Advanced Battery Consortium (or USABC, a consortium of GM, Ford, and Chrysler) analyzed energy storage needs for a micro hybrid automobile with start-stop capability, and with a single power source. USABC has analyzed the start-stop behaviors of many drivers and has developed the requirements for the start-stop batteries (Table 3). The testing procedures to validate the performance and longevity were standardized and published. The guideline for the cost estimates calculations have also been provided, in order to determine the value of the newly developed modules. The analysis effort resulted in a set of requirements which will help the battery manufacturers to develop a module to meet the automotive Original Equipment Manufacturers (OEM) micro hybrid vehicle requirements. Battery developers were invited to submit development proposals and two proposals were selected for 50% cost share with USABC/DOE.

The development of ground unmanned vehicles, driver assistance systems and components according to patent publications

Science.gov (United States)

Saykin, A. M.; Tuktakiev, G. S.; Zhuravlev, A. V.; Zaitseva, E. P.

2018-02-01

The paper contains the analysis of the main trends in the patenting of ground unmanned vehicles, driver assistance systems (ADAS) and unmanned vehicle components abroad during the period from 2010 to 2016. The conclusion was made that the intensity of their patenting abroad increased.

Single Fuel Concept for Croatian Army Ground Vehicles

Directory of Open Access Journals (Sweden)

Robert Spudić

2008-05-01

Full Text Available During the process of approaching the European associationsand NATO the Republic of Croatia has accepted the singlefuel concept for all ground vehicles of the Croatian Army.Croatia has also undertaken to insure that all aircraft, motorvehicles and equipment with turbo-engines or with pressurizedfuel injection, for participation in NATO and PfP led operationscan • operate using the kerosene-based aviation fuel(NATO F-34. The paper gives a brief overview and the resultsof the earned out activities in the Armed Forces of the Republicof Croatia, the expected behaviour of the motor vehicle andpossible delays caused by the use of kerosene fuel (NATOF-34 as fuel for motor vehicles. The paper also gives the advantagesand the drawbacks of the single fuel concept. By acquiringnew data in the Croatian Armed Forces and experienceexchange with other nations about the method of using fuelF-34, the development of the technologies of engine manufacturingand its vital parts or by introducing new standards in theproductjon of fuels and additives new knowledge will certainlybe acquired for providing logistics support in the area of operations,and its final implementation will be a big step forward forthe Republic of Croatia towards Europe and NATO.

Book Review: Stop, Write!

Directory of Open Access Journals (Sweden)

Hans Thulesius

2013-06-01

Full Text Available This book on writing grounded theory is intended for the empirical GT researcher who wants to pursue his/her research until publication. It is the first book devoted entirely to such a crucial issue as writing grounded theory. Thus, Stop, Write: Writing Grounded Theory, is a practical book that fills a gap in GT methodology. In the first chapter of the book, Dr. Glaser says, “Stop unending conceptualization, unending data coverage, and unending listening to others who would egg you on with additional data, ideas and/or requirements or simply wait too long”. The book teaches the reader how to actually write a grounded theory by “simply” writing up the sorted memos. This requires efficient sorting that is dealt with in chapter two on Sorting Memos, which includes precious repetition from Theoretical Sensitivity (1978. How writing can be done effectively is outlined in chapter three The Working Paper. Then follows chapter four on how to rework the first draft with the different tasks of editing for language and professionalism. Thereafter Dr. Glaser discusses Writing Problems in chapter five where he gives useful guidance on how to overcome writing blocks and problems with supervisors and dissertation committees. The book also deals with publishing and with collaboration as experienced between Barney Glaser and the cofounder of grounded theory, Anselm Strauss.

Effect of vertical ground motion on earthquake-induced derailment of railway vehicles over simply-supported bridges

Science.gov (United States)

Jin, Zhibin; Pei, Shiling; Li, Xiaozhen; Liu, Hongyan; Qiang, Shizhong

2016-11-01

The running safety of railway vehicles on bridges can be negatively affected by earthquake events. This phenomenon has traditionally been investigated with only the lateral ground excitation component considered. This paper presented results from a numerical investigation on the contribution of vertical ground motion component to the derailment of vehicles on simply-supported bridges. A full nonlinear wheel-rail contact model was used in the investigation together with the Hertzian contact theory and nonlinear creepage theory, which allows the wheel to jump vertically and separate from the rail. The wheel-rail relative displacement was used as the criterion for derailment events. A total of 18 ground motion records were used in the analysis to account for the uncertainty of ground motions. The results showed that inclusion of vertical ground motion will likely increase the chance of derailment. It is recommended to include vertical ground motion component in earthquake induced derailment analysis to ensure conservative estimations. The derailment event on bridges was found to be more closely related to the deck acceleration rather than the ground acceleration.

LWIR passive perception system for stealthy unmanned ground vehicle night operations

Science.gov (United States)

Lee, Daren; Rankin, Arturo; Huertas, Andres; Nash, Jeremy; Ahuja, Gaurav; Matthies, Larry

2016-05-01

Resupplying forward-deployed units in rugged terrain in the presence of hostile forces creates a high threat to manned air and ground vehicles. An autonomous unmanned ground vehicle (UGV) capable of navigating stealthily at night in off-road and on-road terrain could significantly increase the safety and success rate of such resupply missions for warfighters. Passive night-time perception of terrain and obstacle features is a vital requirement for such missions. As part of the ONR 30 Autonomy Team, the Jet Propulsion Laboratory developed a passive, low-cost night-time perception system under the ONR Expeditionary Maneuver Warfare and Combating Terrorism Applied Research program. Using a stereo pair of forward looking LWIR uncooled microbolometer cameras, the perception system generates disparity maps using a local window-based stereo correlator to achieve real-time performance while maintaining low power consumption. To overcome the lower signal-to-noise ratio and spatial resolution of LWIR thermal imaging technologies, a series of pre-filters were applied to the input images to increase the image contrast and stereo correlator enhancements were applied to increase the disparity density. To overcome false positives generated by mixed pixels, noisy disparities from repeated textures, and uncertainty in far range measurements, a series of consistency, multi-resolution, and temporal based post-filters were employed to improve the fidelity of the output range measurements. The stereo processing leverages multi-core processors and runs under the Robot Operating System (ROS). The night-time passive perception system was tested and evaluated on fully autonomous testbed ground vehicles at SPAWAR Systems Center Pacific (SSC Pacific) and Marine Corps Base Camp Pendleton, California. This paper describes the challenges, techniques, and experimental results of developing a passive, low-cost perception system for night-time autonomous navigation.

INTERSECTION DETECTION BASED ON QUALITATIVE SPATIAL REASONING ON STOPPING POINT CLUSTERS

Directory of Open Access Journals (Sweden)

S. Zourlidou

2016-06-01

Full Text Available The purpose of this research is to propose and test a method for detecting intersections by analysing collectively acquired trajectories of moving vehicles. Instead of solely relying on the geometric features of the trajectories, such as heading changes, which may indicate turning points and consequently intersections, we extract semantic features of the trajectories in form of sequences of stops and moves. Under this spatiotemporal prism, the extracted semantic information which indicates where vehicles stop can reveal important locations, such as junctions. The advantage of the proposed approach in comparison with existing turning-points oriented approaches is that it can detect intersections even when not all the crossing road segments are sampled and therefore no turning points are observed in the trajectories. The challenge with this approach is that first of all, not all vehicles stop at the same location – thus, the stop-location is blurred along the direction of the road; this, secondly, leads to the effect that nearby junctions can induce similar stop-locations. As a first step, a density-based clustering is applied on the layer of stop observations and clusters of stop events are found. Representative points of the clusters are determined (one per cluster and in a last step the existence of an intersection is clarified based on spatial relational cluster reasoning, with which less informative geospatial clusters, in terms of whether a junction exists and where its centre lies, are transformed in more informative ones. Relational reasoning criteria, based on the relative orientation of the clusters with their adjacent ones are discussed for making sense of the relation that connects them, and finally for forming groups of stop events that belong to the same junction.

Intelligence algorithms for autonomous navigation in a ground vehicle

Science.gov (United States)

Petkovsek, Steve; Shakya, Rahul; Shin, Young Ho; Gautam, Prasanna; Norton, Adam; Ahlgren, David J.

2012-01-01

This paper will discuss the approach to autonomous navigation used by "Q," an unmanned ground vehicle designed by the Trinity College Robot Study Team to participate in the Intelligent Ground Vehicle Competition (IGVC). For the 2011 competition, Q's intelligence was upgraded in several different areas, resulting in a more robust decision-making process and a more reliable system. In 2010-2011, the software of Q was modified to operate in a modular parallel manner, with all subtasks (including motor control, data acquisition from sensors, image processing, and intelligence) running simultaneously in separate software processes using the National Instruments (NI) LabVIEW programming language. This eliminated processor bottlenecks and increased flexibility in the software architecture. Though overall throughput was increased, the long runtime of the image processing process (150 ms) reduced the precision of Q's realtime decisions. Q had slow reaction times to obstacles detected only by its cameras, such as white lines, and was limited to slow speeds on the course. To address this issue, the image processing software was simplified and also pipelined to increase the image processing throughput and minimize the robot's reaction times. The vision software was also modified to detect differences in the texture of the ground, so that specific surfaces (such as ramps and sand pits) could be identified. While previous iterations of Q failed to detect white lines that were not on a grassy surface, this new software allowed Q to dynamically alter its image processing state so that appropriate thresholds could be applied to detect white lines in changing conditions. In order to maintain an acceptable target heading, a path history algorithm was used to deal with local obstacle fields and GPS waypoints were added to provide a global target heading. These modifications resulted in Q placing 5th in the autonomous challenge and 4th in the navigation challenge at IGVC.

Robust H∞ output-feedback control for path following of autonomous ground vehicles

Science.gov (United States)

Hu, Chuan; Jing, Hui; Wang, Rongrong; Yan, Fengjun; Chadli, Mohammed

2016-03-01

This paper presents a robust H∞ output-feedback control strategy for the path following of autonomous ground vehicles (AGVs). Considering the vehicle lateral velocity is usually hard to measure with low cost sensor, a robust H∞ static output-feedback controller based on the mixed genetic algorithms (GA)/linear matrix inequality (LMI) approach is proposed to realize the path following without the information of the lateral velocity. The proposed controller is robust to the parametric uncertainties and external disturbances, with the parameters including the tire cornering stiffness, vehicle longitudinal velocity, yaw rate and road curvature. Simulation results based on CarSim-Simulink joint platform using a high-fidelity and full-car model have verified the effectiveness of the proposed control approach.

Impact of Friction Reduction Technologies on Fuel Economy for Ground Vehicles

Science.gov (United States)

2009-08-13

UNCLAS: Dist A. Approved for public release IMPACT OF FRICTION REDUCTION TECHNOLOGIES ON FUEL ECONOMY FOR GROUND VEHICLES G. R. Fenske , R. A. Erck...PROGRAM ELEMENT NUMBER 6. AUTHOR(S) G.R. Fenske ; R.A. Erck; O.O. Ajayi; A. Masoner’ A.S. Confort 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT

Unmanned Ground Vehicle Navigation and Coverage Hole Patching in Wireless Sensor Networks

Science.gov (United States)

Zhang, Guyu

2013-01-01

This dissertation presents a study of an Unmanned Ground Vehicle (UGV) navigation and coverage hole patching in coordinate-free and localization-free Wireless Sensor Networks (WSNs). Navigation and coverage maintenance are related problems since coverage hole patching requires effective navigation in the sensor network environment. A…

Emergency Brake for Tracked Vehicles

Science.gov (United States)

Green, G. L.; Hooper, S. L.

1986-01-01

Caliper brake automatically stops tracked vehicle as vehicle nears end of travel. Bar on vehicle, traveling to right, dislodges block between brake pads. Pads then press against bar, slowing vehicle by friction. Emergencybraking system suitable for elevators, amusement rides and machine tools.

Inspection vehicle

International Nuclear Information System (INIS)

Takahashi, Masaki; Omote, Tatsuyuki; Yoneya, Yutaka; Tanaka, Keiji; Waki, Tetsuro; Yoshida, Tomiji; Kido, Tsuyoshi.

1993-01-01

An inspection vehicle comprises a small-sized battery directly connected with a power motor or a direct power source from trolly lines and a switching circuit operated by external signals. The switch judges advance or retreat by two kinds of signals and the inspection vehicle is recovered by self-running. In order to recover the abnormally stopped inspection vehicle to the targeted place, the inspection vehicle is made in a free-running state by using a clutch mechanism and is pushed by an other vehicle. (T.M.)

A model predictive speed tracking control approach for autonomous ground vehicles

Science.gov (United States)

Zhu, Min; Chen, Huiyan; Xiong, Guangming

2017-03-01

This paper presents a novel speed tracking control approach based on a model predictive control (MPC) framework for autonomous ground vehicles. A switching algorithm without calibration is proposed to determine the drive or brake control. Combined with a simple inverse longitudinal vehicle model and adaptive regulation of MPC, this algorithm can make use of the engine brake torque for various driving conditions and avoid high frequency oscillations automatically. A simplified quadratic program (QP) solving algorithm is used to reduce the computational time, and the approach has been applied in a 16-bit microcontroller. The performance of the proposed approach is evaluated via simulations and vehicle tests, which were carried out in a range of speed-profile tracking tasks. With a well-designed system structure, high-precision speed control is achieved. The system can robustly model uncertainty and external disturbances, and yields a faster response with less overshoot than a PI controller.

Modeling and Simulation of an Unmanned Ground Vehicle Power System

Science.gov (United States)

2014-03-28

Wilhelm, A. N., Surgenor, B. W., and Pharoah, J. G., “Design and evaluation of a micro-fuel-cell-based power system for a mobile robot,” Mechatronics ... Embedded Control Systems ], Control Engineering, 91–116, Birkhuser Boston (2005). [12] Alur, R., Courcoubetis, C., Halbwachs, N., Henzinger, T., Ho, P.-H...Modeling and Simulation of an Unmanned Ground Vehicle Power System John Brodericka∗, Jack Hartnerb, Dawn Tilburya, and Ella Atkinsa aThe University

An Improved Model for Headway-Based Bus Service Unreliability Prevention with Vehicle Load Capacity Constraint at Bus Stops

Directory of Open Access Journals (Sweden)

Weiya Chen

2012-01-01

Full Text Available This paper presents an improved model for improving headway-based bus route service reliability at bus stops using real-time preventive operation control, taking into account dynamic interaction among random passenger demand, stochastic driving conditions of route segments, and vehicle load capacity constraint. In this model, the real-time information of passenger demand and vehicle operation is involved to predict the imminent unacceptable headway deviation, in the case of which some in-time preventive control strategies are deployed according to the given control rules. As a case study, a single fixed bus route with high-frequency services was simulated and different scenarios of real-time preventive operation control were performed. Headway adherence and average passenger wait time were used to measure bus service reliability. The results show that the improved model is closer to the real bus route service, and using real-time information to predict potential service unreliability and trigger in-time preventive control can reduce bus bunching and avoid big gap.

Drinking and driving behavior at stop signs and red lights.

Science.gov (United States)

Wan, Jingyan; Wu, Changxu; Zhang, Yiqi; Houston, Rebecca J; Chen, Chang Wen; Chanawangsa, Panya

2017-07-01

Alcohol is one of the principal risk factors for motor vehicle crashes. One factor that contributes to vehicle crashes is noncompliance with stop signs and red lights. The present experiment investigated the effects of alcohol and drinking patterns on driving behavior at stop signs and red lights. 28 participants participated in drinking and simulated driving sessions during which they received a moderate dose of alcohol (0.08% BAC) or a placebo. Simulated driving tasks measured participants' driving performance at stop signs and red lights in response to each dose. Results suggested that alcohol impaired the driver control of speed and direction and prolonged their simple and complex reaction time, which were exhibited by impaired speed and lateral control, longer reaction time when the lights turned yellow, and lower deceleration towards stop signs and red lights. Visual degradation may also occur under alcohol intake. It was also suggested that alcohol impaired non-binge drinkers more severely. To be specific, higher acceleration was observed in impaired non-binge drinkers. Copyright © 2017 Elsevier Ltd. All rights reserved.

Aircraft and ground vehicle friction correlation test results obtained under winter runway conditions during joint FAA/NASA Runway Friction Program

Science.gov (United States)

Yager, Thomas J.; Vogler, William A.; Baldasare, Paul

1988-01-01

Aircraft and ground vehicle friction data collected during the Joint FAA/NASA Runway Friction Program under winter runway conditions are discussed and test results are summarized. The relationship between the different ground vehicle friction measurements obtained on compacted snow- and ice-covered conditions is defined together with the correlation to aircraft tire friction performance under similar runway conditions.

14 CFR 25.109 - Accelerate-stop distance.

Science.gov (United States)

2010-01-01

... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Flight Performance § 25.109 Accelerate-stop distance. (a...) The maximum tire-to-ground wet runway braking coefficient of friction is defined as: ER18FE98.004 Where— Tire Pressure=maximum airplane operating tire pressure (psi); μt/gMAX=maximum tire-to-ground...

Empirical Analysis and Modeling of Stop-Line Crossing Time and Speed at Signalized Intersections

Directory of Open Access Journals (Sweden)

Keshuang Tang

2016-12-01

Full Text Available In China, a flashing green (FG indication of 3 s followed by a yellow (Y indication of 3 s is commonly applied to end the green phase at signalized intersections. Stop-line crossing behavior of drivers during such a phase transition period significantly influences safety performance of signalized intersections. The objective of this study is thus to empirically analyze and model drivers’ stop-line crossing time and speed in response to the specific phase transition period of FG and Y. High-resolution trajectories for 1465 vehicles were collected at three rural high-speed intersections with a speed limit of 80 km/h and two urban intersections with a speed limit of 50 km/h in Shanghai. With the vehicle trajectory data, statistical analyses were performed to look into the general characteristics of stop-line crossing time and speed at the two types of intersections. A multinomial logit model and a multiple linear regression model were then developed to predict the stop-line crossing patterns and speeds respectively. It was found that the percentage of stop-line crossings during the Y interval is remarkably higher and the stop-line crossing time is approximately 0.7 s longer at the urban intersections, as compared with the rural intersections. In addition, approaching speed and distance to the stop-line at the onset of FG as well as area type significantly affect the percentages of stop-line crossings during the FG and Y intervals. Vehicle type and stop-line crossing pattern were found to significantly influence the stop-line crossing speed, in addition to the above factors. The red-light-running seems to occur more frequently at the large intersections with a long cycle length.

On the radar cross section (RCS) prediction of vehicles moving on the ground

Energy Technology Data Exchange (ETDEWEB)

Sabihi, Ahmad [Department of Mathematical Sciences, Sharif University of Technology, Tehran (Iran, Islamic Republic of)

2014-12-10

As readers should be aware, Radar Cross Section depends on the factors such as: Wave frequency and polarization, Target dimension, angle of ray incidence, Target’s material and covering, Type of radar system as monostatic or bistatic, space in which contains target and propagating waves, and etc. Having moved or stationed in vehicles can be effective in RCS values. Here, we investigate effective factors in RCS of moving targets on the ground or sea. Image theory in electromagnetic applies to be taken into account RCS of a target over the ground or sea.

On the radar cross section (RCS) prediction of vehicles moving on the ground

International Nuclear Information System (INIS)

Sabihi, Ahmad

2014-01-01

As readers should be aware, Radar Cross Section depends on the factors such as: Wave frequency and polarization, Target dimension, angle of ray incidence, Target’s material and covering, Type of radar system as monostatic or bistatic, space in which contains target and propagating waves, and etc. Having moved or stationed in vehicles can be effective in RCS values. Here, we investigate effective factors in RCS of moving targets on the ground or sea. Image theory in electromagnetic applies to be taken into account RCS of a target over the ground or sea

VRLA automotive batteries for stop&go and dual battery systems

Science.gov (United States)

May, G. J.; Calasanzio, D.; Aliberti, R.

The electrical power requirements for vehicles are continuing to increase and evolve. A substantial amount of effort has been directed towards the development of 36/42 V systems as a route to higher power with reduced current levels but high implementation costs have resulted in the introduction of these systems becoming deferred. In the interim, however, alternator power outputs at 14 V are being increased substantially and at the same time the requirements for batteries are becoming more intensive. In particular, stop&go systems and wire-based vehicle systems are resulting in new demands. For stop&go, the engine is stopped each time the vehicle comes to rest and is restarted when the accelerator is pressed again. This results in an onerous duty cycle with many shallow discharge cycles. Flooded lead-acid batteries cannot meet this duty cycle and valve-regulated lead-acid (VRLA) batteries are needed to meet the demands that are applied. For wire-based systems, such as brake-by-wire or steer-by-wire, electrical power has become more critical and although the alternator and battery provide double redundancy, triple redundancy with a small reserve battery is specified. In this case, a small VRLA battery can be used and is optimised for standby service rather than for repeated discharges. The background to these applications is considered and test results under simulated operating conditions are discussed. Good performance can be obtained in batteries adapted for both applications. Battery management is also critical for both applications: in stop&go service, the state-of-charge (SOC) and state-of-health (SOH) need to be monitored to ensure that the vehicle can be restarted; for reserve or back-up batteries, the SOC and SOH are monitored to verify that the battery is always capable of carrying out the duty cycle if required. Practical methods of battery condition monitoring will be described.

Flow Characteristics of Ground Vehicle Wake and Its Response to Flow Control

Science.gov (United States)

Sellappan, Prabu; McNally, Jonathan; Alvi, Farrukh

2017-11-01

Air pollution, fuel shortages, and cost savings are some of the many incentives for improving the aerodynamics of vehicles. Reducing wake-induced aerodynamic drag, which is dependent on flow topology, on modern passenger vehicles is important for improving fuel consumption rates which directly affect the environment. In this research, an active flow control technique is applied on a generic ground vehicle, a 25°Ahmed model, to investigate its effect on the flow topology in the near-wake. The flow field of this canonical bluff body is extremely rich, with complex and unsteady flow features such as trailing wake vortices and c-pillar vortices. The spatio-temporal response of these flow features to the application of steady microjet actuators is investigated. The responses are characterized independently through time-resolved and volumetric velocity field measurements. The accuracy and cost of volumetric measurements in this complex flow field through Stereoscopic- and Tomographic- Particle Image Velocimetry (PIV) will also be commented upon. National Science Foundation PIRE Program.

Personnel and Vehicle Data Collection at Aberdeen Proving Ground (APG) and its Distribution for Research

Science.gov (United States)

2015-10-01

28 Magnetometer Applied Physics Model 1540-digital 3-axis fluxgate 5 Amplifiers Alligator Technologies USBPGF-S1 programmable instrumentation...Acoustic, Seismic, magnetic, footstep, vehicle, magnetometer , geophone, unattended ground sensor (UGS) 16. SECURITY CLASSIFICATION OF: 17. LIMITATION

Protection against malevolent use of vehicles at Nuclear Power Plants. Vehicle barrier system selection guidance

International Nuclear Information System (INIS)

Nebuda, D.T.

1994-08-01

This manual provides a simplified procedure for selecting land vehicle barriers that will stop the design basis vehicle threat adopted by the U.S. Nuclear Regulatory Commission. Proper selection and construction of vehicle barriers should prevent intrusion of the design basis vehicle. In addition, vital safety related equipment should survive a design basis vehicle bomb attack when vehicle barriers are properly selected, sited, and constructed. This manual addresses passive vehicle barriers, active vehicle barriers, and site design features that can be used to reduce vehicle impact velocity

Impact of mesh tracks and low-ground-pressure vehicle use on blanket peat hydrology

Science.gov (United States)

McKendrick-Smith, Kathryn; Holden, Joseph; Parry, Lauren

2016-04-01

Peatlands are subject to multiple uses including drainage, farming and recreation. Low-ground-pressure vehicle access is desirable by land owners and tracks facilitate access. However, there is concern that such activity may impact peat hydrology and so granting permission for track installation has been problematic, particularly without evidence for decision-making. We present the first comprehensive study of mesh track and low-ground-pressure vehicle impacts on peatland hydrology. In the sub-arctic oceanic climate of the Moor House World Biosphere Reserve in the North Pennines, UK, a 1.5 km long experimental track was installed to investigate hydrological impacts. Surface vegetation was cut and the plastic mesh track pinned into the peat surface. The experimental track was split into 7 treatments, designed to reflect typical track usage (0 - 5 vehicle passes per week) and varying vehicle weight. The greatest hydrological impacts were expected for sections of track subject to more frequent vehicle use and in close proximity to the track. In total 554 dipwells (including 15 automated recording at 15-min intervals) were monitored for water-table depth, positioned to capture potential spatial variability in response. Before track installation, samples for vertical and lateral hydraulic conductivity (Ks) analysis (using the modified cube method) were taken at 0-10 cm depth from a frequently driven treatment (n = 15), an infrequently driven treatment (0.5 passes per week) (n = 15) and a control site with no track/driving (n = 15). The test was repeated after 16 months of track use. We present a spatially and temporally rich water-table dataset from the study site showing how the impacts of the track on water table are spatially highly variable. Water-table depths across the site were shallow, typically within the upper 10 cm of the peat profile for > 75% of the time. We show that mesh track and low-ground-pressure vehicle impacts on water-table depth were small except

Achieving integrated convoys: cargo unmanned ground vehicle development and experimentation

Science.gov (United States)

Zych, Noah; Silver, David; Stager, David; Green, Colin; Pilarski, Thomas; Fischer, Jacob

2013-05-01

The Cargo UGV project was initiated in 2010 with the aim of developing and experimenting with advanced autonomous vehicles capable of being integrated unobtrusively into manned logistics convoys. The intent was to validate two hypotheses in complex, operationally representative environments: first, that unmanned tactical wheeled vehicles provide a force protection advantage by creating standoff distance to warfighters during ambushes or improvised explosive device attacks; and second, that these UGVs serve as force multipliers by enabling a single operator to control multiple unmanned assets. To assess whether current state-of-the-art autonomous vehicle technology was sufficiently capable to permit resupply missions to be executed with decreased risk and reduced manpower, and to assess the effect of UGVs on customary convoy tactics, the Marine Corps Warfighting Laboratory and the Joint Ground Robotics Enterprise sponsored Oshkosh Defense and the National Robotics Engineering Center to equip two standard Marine Corps cargo trucks for autonomous operation. This paper details the system architecture, hardware implementation, and software modules developed to meet the vehicle control, perception, and planner requirements compelled by this application. Additionally, the design of a custom human machine interface and an accompanying training program are described, as is the creation of a realistic convoy simulation environment for rapid system development. Finally, results are conveyed from a warfighter experiment in which the effectiveness of the training program for novice operators was assessed, and the impact of the UGVs on convoy operations was observed in a variety of scenarios via direct comparison to a fully manned convoy.

Magnetic Sensor for Detection of Ground Vehicles Based on Microwave Spin Wave Generation in Ferrite Films

National Research Council Canada - National Science Library

Slavin, A; Tiberkevich, V; Bankowski, E

2006-01-01

We propose to use the magnetic signatures, formed either by the residual magnetization or by deformation of the local Earth's magnetic field by large metal masses, for distant detection of ground vehicles...

Infrared stereo calibration for unmanned ground vehicle navigation

Science.gov (United States)

Harguess, Josh; Strange, Shawn

2014-06-01

The problem of calibrating two color cameras as a stereo pair has been heavily researched and many off-the-shelf software packages, such as Robot Operating System and OpenCV, include calibration routines that work in most cases. However, the problem of calibrating two infrared (IR) cameras for the purposes of sensor fusion and point could generation is relatively new and many challenges exist. We present a comparison of color camera and IR camera stereo calibration using data from an unmanned ground vehicle. There are two main challenges in IR stereo calibration; the calibration board (material, design, etc.) and the accuracy of calibration pattern detection. We present our analysis of these challenges along with our IR stereo calibration methodology. Finally, we present our results both visually and analytically with computed reprojection errors.

A pose estimation method for unmanned ground vehicles in GPS denied environments

Science.gov (United States)

Tamjidi, Amirhossein; Ye, Cang

2012-06-01

This paper presents a pose estimation method based on the 1-Point RANSAC EKF (Extended Kalman Filter) framework. The method fuses the depth data from a LIDAR and the visual data from a monocular camera to estimate the pose of a Unmanned Ground Vehicle (UGV) in a GPS denied environment. Its estimation framework continuy updates the vehicle's 6D pose state and temporary estimates of the extracted visual features' 3D positions. In contrast to the conventional EKF-SLAM (Simultaneous Localization And Mapping) frameworks, the proposed method discards feature estimates from the extended state vector once they are no longer observed for several steps. As a result, the extended state vector always maintains a reasonable size that is suitable for online calculation. The fusion of laser and visual data is performed both in the feature initialization part of the EKF-SLAM process and in the motion prediction stage. A RANSAC pose calculation procedure is devised to produce pose estimate for the motion model. The proposed method has been successfully tested on the Ford campus's LIDAR-Vision dataset. The results are compared with the ground truth data of the dataset and the estimation error is ~1.9% of the path length.

Hybrid Map-Based Navigation Method for Unmanned Ground Vehicle in Urban Scenario

Directory of Open Access Journals (Sweden)

Huiyan Chen

2013-07-01

Full Text Available To reduce the data size of metric map and map matching computational cost in unmanned ground vehicle self-driving navigation in urban scenarios, a metric-topological hybrid map navigation system is proposed in this paper. According to the different positioning accuracy requirements, urban areas are divided into strong constraint (SC areas, such as roads with lanes, and loose constraint (LC areas, such as intersections and open areas. As direction of the self-driving vehicle is provided by traffic lanes and global waypoints in the road network, a simple topological map is fit for the navigation in the SC areas. While in the LC areas, the navigation of the self-driving vehicle mainly relies on the positioning information. Simultaneous localization and mapping technology is used to provide a detailed metric map in the LC areas, and a window constraint Markov localization algorithm is introduced to achieve accurate position using laser scanner. Furthermore, the real-time performance of the Markov algorithm is enhanced by using a constraint window to restrict the size of the state space. By registering the metric maps into the road network, a hybrid map of the urban scenario can be constructed. Real unmanned vehicle mapping and navigation tests demonstrated the capabilities of the proposed method.

Safety, operational, and energy impacts of in-vehicle adaptive stop displays using connected vehicle technology.

Science.gov (United States)

2015-07-01

Un-signalized intersections create multiple opportunities for missed or misunderstood information. : Stop sign-controlled intersections have also been shown to be a source of delay and emissions due : to their frequent, often inappropriate use. By us...

A Conceptual Approach for Optimising Bus Stop Spacing

Science.gov (United States)

Johar, Amita; Jain, S. S.; Garg, P. k.

2017-06-01

An efficient public transportation system is essential of any country. The growth, development and shape of the urban areas are mainly due to availability of good transportation (Shah et al. in Inst Town Plan India J 5(3):50-59, 1). In developing countries, like India, travel by local bus in a city is very common. The accidents, congestion, pollution and appropriate location of bus stops are the major problems arising in metropolitan cities. Among all the metropolitan cities in India, Delhi has highest percentage of growth of population and vehicles. Therefore, it is important to adopt efficient and effective ways to improve mobility in different metropolitan cities in order to overcome the problem and to reduce the number of private vehicles on the road. The primary objective of this paper is to present a methodology for developing a model for optimum bus stop spacing (OBSS). It describes the evaluation of existing urban bus route, data collection, development of model for optimizing urban bus route and application of model. In this work, the bus passenger generalized cost method is used to optimize the spacing between bus stops. For the development of model, a computer program is required to be written. The applicability of the model has been evaluated by taking the data of urban bus route of Delhi Transport Corporation (DTC) in Excel sheet in first phase. Later on, it is proposed to develop a programming in C++ language. The developed model is expected to be useful to transport planner for rational design of the spacing of bus stops to save travel time and to generalize operating cost. After analysis it is found that spacing between the bus stop comes out to be between 250 and 500 m. The Proposed Spacing of bus stops is done considering the points that they don't come nearer to metro/rail station, entry or exit of flyover and near traffic signal.

Design of limited-stop service based on the degree of unbalance of passenger demand

Science.gov (United States)

2018-01-01

This paper presents a limited-stop service for a bus fleet to meet the unbalanced demand of passengers on a bus route and to improve the transit service of the bus route. This strategy includes two parts: a degree assessment of unbalanced passenger demand and an optimization of the limited-stop service. The degree assessment of unbalanced passenger demand, which is based on the different passenger demand between stations and the unbalance of passengers within the station, is used to judge whether implementing the limited-stop service is necessary for a bus route. The optimization of limited-stop service considers the influence of stop skipping action and bus capacity on the left-over passengers to determine the proper skipping stations for the bus fleet serving the entire route by minimizing both the waiting time and in-vehicle time of passengers and the running time of vehicles. A solution algorithm based on genetic algorithm is also presented to evaluate the degree of unbalanced passenger demand and optimize the limited-stop scheme. Then, the proper strategy is tested on a bus route in Changchun city of China. The threshold of degree assessment of unbalanced passenger demand can be calibrated and adapted to different passenger demands. PMID:29505585

Design of limited-stop service based on the degree of unbalance of passenger demand.

Science.gov (United States)

Zhang, Hu; Zhao, Shuzhi; Liu, Huasheng; Liang, Shidong

2018-01-01

This paper presents a limited-stop service for a bus fleet to meet the unbalanced demand of passengers on a bus route and to improve the transit service of the bus route. This strategy includes two parts: a degree assessment of unbalanced passenger demand and an optimization of the limited-stop service. The degree assessment of unbalanced passenger demand, which is based on the different passenger demand between stations and the unbalance of passengers within the station, is used to judge whether implementing the limited-stop service is necessary for a bus route. The optimization of limited-stop service considers the influence of stop skipping action and bus capacity on the left-over passengers to determine the proper skipping stations for the bus fleet serving the entire route by minimizing both the waiting time and in-vehicle time of passengers and the running time of vehicles. A solution algorithm based on genetic algorithm is also presented to evaluate the degree of unbalanced passenger demand and optimize the limited-stop scheme. Then, the proper strategy is tested on a bus route in Changchun city of China. The threshold of degree assessment of unbalanced passenger demand can be calibrated and adapted to different passenger demands.

33 CFR 127.1311 - Motor vehicles.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Motor vehicles. 127.1311 Section... Waterfront Facilities Handling Liquefied Hazardous Gas Operations § 127.1311 Motor vehicles. (a) When LHG is... operator shall ensure that no person— (1) Stops or parks a motor vehicle in a space other than a designated...

Development of a Model-Based Systems Engineering Application for the Ground Vehicle Robotics Sustainment Industrial Base

Science.gov (United States)

2013-02-04

Ground Vehicle Systems Engineering Technology Symposium HC Human Capital HIIT Helsinki Institute of Information Technology UNCLASSIFIED vii...Technology (TKK), and the Helsinki Institute of Information Technology ( HIIT ), the report introduced the concept and the state-of-the-art in the market

Idling Reduction for Personal Vehicles

Energy Technology Data Exchange (ETDEWEB)

None

2015-05-07

Fact sheet on reducing engine idling in personal vehicles. Idling your vehicle--running your engine when you're not driving it--truly gets you nowhere. Idling reduces your vehicle's fuel economy, costs you money, and creates pollution. Idling for more than 10 seconds uses more fuel and produces more emissions that contribute to smog and climate change than stopping and restarting your engine does.

NASA Planning for Orion Multi-Purpose Crew Vehicle Ground Operations

Science.gov (United States)

Letchworth, Gary; Schlierf, Roland

2011-01-01

tools included Kaizen/Lean events, mockups and human factors analysis. The majority of products developed by this team are applicable as KSC prepares 21st Century Ground Systems for the Orion Multi-Purpose Crew Vehicle and Space Launch System.

Unmanned Ground Vehicle

Science.gov (United States)

2001-11-01

Systems ( JAUGS ). JAUGS is a JRP technology initiative under the cognizance of the Aviation and Missile Command Research, Development and Engineering Center...AMRDEC). The JAUGS focus is on developing a high-level command and control architecture for UGVs. As defined in the JRP Glossary, “ JAUGS is an upper...vehicle platforms and missions. JAUGS uses the Society of Automotive Engineers Generic Open Architecture framework to classify UGV interfaces and

Inferring Stop-Locations from WiFi.

Directory of Open Access Journals (Sweden)

David Kofoed Wind

Full Text Available Human mobility patterns are inherently complex. In terms of understanding these patterns, the process of converting raw data into series of stop-locations and transitions is an important first step which greatly reduces the volume of data, thus simplifying the subsequent analyses. Previous research into the mobility of individuals has focused on inferring 'stop locations' (places of stationarity from GPS or CDR data, or on detection of state (static/active. In this paper we bridge the gap between the two approaches: we introduce methods for detecting both mobility state and stop-locations. In addition, our methods are based exclusively on WiFi data. We study two months of WiFi data collected every two minutes by a smartphone, and infer stop-locations in the form of labelled time-intervals. For this purpose, we investigate two algorithms, both of which scale to large datasets: a greedy approach to select the most important routers and one which uses a density-based clustering algorithm to detect router fingerprints. We validate our results using participants' GPS data as well as ground truth data collected during a two month period.

Spectroscopy of hypernuclei with stopped kaons

International Nuclear Information System (INIS)

Tamura, H.; Brueckner, W.; Doebbeling, H.

1987-09-01

Pion momentum spectra from K - absorption at rest on various nuclear targets were measured by means of a magnetic spectrometer with wide momentum range (100 ∼ 300 MeV/c). The ground state of Σ - hypernucleus, if well bound with a narrow width, is expected to be populated in 12 C(stopped K - , π + ) inclusive (untagged) spectrum, but such a peak was not observed. The spectrum is compared with the DWIA calculations by Morimatsu and Yazaki, indicating that the depth of the nuclear potential of Σ - is shallower than 12 MeV, and that its imaginary part is larger than 5 MeV if the potential depth is about 10 MeV. In the 12 C(stopped K - , π - ) spectrum, the ground state ((p3/2) n -1 (s1/2) Λ ) and the excited states ((p3/2) n -1 (p) Λ ) of Λ 12 C were observed, and their formation probabilities were roughly in agreement with the results of DWIA calculations. In the π - spectra on 12 C, 9 Be, and 7 Li targets a distinct peak was observed at 132.1 ± 0.7 MeV/c. It is ascribed to π - from the mesic decay of Λ 4 H; Λ 4 H → 4 He π - . The formation probability of Λ 4 H on C, Be, or Li target is much larger than those of the discrete states of Λ 12 C via the direct (stopped K - , π - ) reaction. (author)

The design and results of an algorithm for intelligent ground vehicles

Science.gov (United States)

Duncan, Matthew; Milam, Justin; Tote, Caleb; Riggins, Robert N.

2010-01-01

This paper addresses the design, design method, test platform, and test results of an algorithm used in autonomous navigation for intelligent vehicles. The Bluefield State College (BSC) team created this algorithm for its 2009 Intelligent Ground Vehicle Competition (IGVC) robot called Anassa V. The BSC robotics team is comprised of undergraduate computer science, engineering technology, marketing students, and one robotics faculty advisor. The team has participated in IGVC since the year 2000. A major part of the design process that the BSC team uses each year for IGVC is a fully documented "Post-IGVC Analysis." Over the nine years since 2000, the lessons the students learned from these analyses have resulted in an ever-improving, highly successful autonomous algorithm. The algorithm employed in Anassa V is a culmination of past successes and new ideas, resulting in Anassa V earning several excellent IGVC 2009 performance awards, including third place overall. The paper will discuss all aspects of the design of this autonomous robotic system, beginning with the design process and ending with test results for both simulation and real environments.

Analyzing the Effect of Passenger-Requested Unscheduled Stops on Demand

Directory of Open Access Journals (Sweden)

Dejan Paliska

2007-07-01

Full Text Available This paper discusses the effect of unscheduled stops requestedby passengers on bus transit demand and presents theresults of its study. In the research a set of regression modelsthat estimate the route-level demand were developed using datacollected with Automatic Passenger Counters and AutomaticVehicle Location systems installed on buses, and demographic,socio-economic and land use information from other sources.The results obtained indicate that the number of rider-requestedunscheduled stops have no significant effect on demand,suggesting that the company policy which tolerates unscheduledstops is inadequate for attracting new riders.

Monocular Camera/IMU/GNSS Integration for Ground Vehicle Navigation in Challenging GNSS Environments

Directory of Open Access Journals (Sweden)

Dennis Akos

2012-03-01

Full Text Available Low-cost MEMS-based IMUs, video cameras and portable GNSS devices are commercially available for automotive applications and some manufacturers have already integrated such facilities into their vehicle systems. GNSS provides positioning, navigation and timing solutions to users worldwide. However, signal attenuation, reflections or blockages may give rise to positioning difficulties. As opposed to GNSS, a generic IMU, which is independent of electromagnetic wave reception, can calculate a high-bandwidth navigation solution, however the output from a self-contained IMU accumulates errors over time. In addition, video cameras also possess great potential as alternate sensors in the navigation community, particularly in challenging GNSS environments and are becoming more common as options in vehicles. Aiming at taking advantage of these existing onboard technologies for ground vehicle navigation in challenging environments, this paper develops an integrated camera/IMU/GNSS system based on the extended Kalman filter (EKF. Our proposed integration architecture is examined using a live dataset collected in an operational traffic environment. The experimental results demonstrate that the proposed integrated system provides accurate estimations and potentially outperforms the tightly coupled GNSS/IMU integration in challenging environments with sparse GNSS observations.

Monocular camera/IMU/GNSS integration for ground vehicle navigation in challenging GNSS environments.

Science.gov (United States)

Chu, Tianxing; Guo, Ningyan; Backén, Staffan; Akos, Dennis

2012-01-01

Low-cost MEMS-based IMUs, video cameras and portable GNSS devices are commercially available for automotive applications and some manufacturers have already integrated such facilities into their vehicle systems. GNSS provides positioning, navigation and timing solutions to users worldwide. However, signal attenuation, reflections or blockages may give rise to positioning difficulties. As opposed to GNSS, a generic IMU, which is independent of electromagnetic wave reception, can calculate a high-bandwidth navigation solution, however the output from a self-contained IMU accumulates errors over time. In addition, video cameras also possess great potential as alternate sensors in the navigation community, particularly in challenging GNSS environments and are becoming more common as options in vehicles. Aiming at taking advantage of these existing onboard technologies for ground vehicle navigation in challenging environments, this paper develops an integrated camera/IMU/GNSS system based on the extended Kalman filter (EKF). Our proposed integration architecture is examined using a live dataset collected in an operational traffic environment. The experimental results demonstrate that the proposed integrated system provides accurate estimations and potentially outperforms the tightly coupled GNSS/IMU integration in challenging environments with sparse GNSS observations.

Monocular Camera/IMU/GNSS Integration for Ground Vehicle Navigation in Challenging GNSS Environments

Science.gov (United States)

Chu, Tianxing; Guo, Ningyan; Backén, Staffan; Akos, Dennis

2012-01-01

Low-cost MEMS-based IMUs, video cameras and portable GNSS devices are commercially available for automotive applications and some manufacturers have already integrated such facilities into their vehicle systems. GNSS provides positioning, navigation and timing solutions to users worldwide. However, signal attenuation, reflections or blockages may give rise to positioning difficulties. As opposed to GNSS, a generic IMU, which is independent of electromagnetic wave reception, can calculate a high-bandwidth navigation solution, however the output from a self-contained IMU accumulates errors over time. In addition, video cameras also possess great potential as alternate sensors in the navigation community, particularly in challenging GNSS environments and are becoming more common as options in vehicles. Aiming at taking advantage of these existing onboard technologies for ground vehicle navigation in challenging environments, this paper develops an integrated camera/IMU/GNSS system based on the extended Kalman filter (EKF). Our proposed integration architecture is examined using a live dataset collected in an operational traffic environment. The experimental results demonstrate that the proposed integrated system provides accurate estimations and potentially outperforms the tightly coupled GNSS/IMU integration in challenging environments with sparse GNSS observations. PMID:22736999

Advanced protection technology for ground combat vehicles.

Science.gov (United States)

Bosse, Timothy G

2012-01-01

Just as highway drivers use radar detectors to attempt to stay ahead of police armed with the latest radar technology, the Armed Forces are locked in a spiral to protect combat vehicles and their crews against the latest threats in both the contemporary operating environment and the anticipated operating environment (ie, beyond 2020). In response to bigger, heavier, or better-protected vehicles, adversaries build and deploy larger explosive devices or bombs. However, making improvements to combat vehicles is much more expensive than deploying larger explosives. In addition, demand is increasing for lighter-weight vehicles capable of rapid deployment. Together, these two facts give the threat a clear advantage in the future. To protect vehicles and crews, technologies focusing on detection and hit avoidance, denial of penetration, and crew survivability must be combined synergistically to provide the best chance of survival on the modern battlefield.

Evaluation of two transport aircraft and several ground test vehicle friction measurements obtained for various runway surface types and conditions. A summary of test results from joint FAA/NASA Runway Friction Program

Science.gov (United States)

Yager, Thomas J.; Vogler, William A.; Baldasare, Paul

1990-01-01

Tests with specially instrumented NASA Boeing 737 and 727 aircraft together with several different ground friction measuring devices were conducted for a variety of runway surface types and conditions. These tests are part of joint FAA/NASA Aircraft/Ground Vehicle Runway Friction Program aimed at obtaining a better understanding of aircraft ground handling performance under adverse weather conditions and defining relationships between aircraft and ground vehicle tire friction measurements. Aircraft braking performance on dry, wet, snow and ice-covered runway conditions is discussed as well as ground vehicle friction data obtained under similar runway conditions. For a given contaminated runway surface condition, the correlation between ground vehicles and aircraft friction data is identified. The influence of major test parameters on friction measurements such as speed, test tire characteristics, type and amount of surface contaminant, and ambient temperature are discussed. The effect of surface type on wet friction levels is also evaluated from comparative data collected on grooved and ungrooved concrete and asphalt surfaces.

Application of a distributed systems architecture for increased speed in image processing on an autonomous ground vehicle

Science.gov (United States)

Wright, Adam A.; Momin, Orko; Shin, Young Ho; Shakya, Rahul; Nepal, Kumud; Ahlgren, David J.

2010-01-01

This paper presents the application of a distributed systems architecture to an autonomous ground vehicle, Q, that participates in both the autonomous and navigation challenges of the Intelligent Ground Vehicle Competition. In the autonomous challenge the vehicle is required to follow a course, while avoiding obstacles and staying within the course boundaries, which are marked by white lines. For the navigation challenge, the vehicle is required to reach a set of target destinations, known as way points, with given GPS coordinates and avoid obstacles that it encounters in the process. Previously the vehicle utilized a single laptop to execute all processing activities including image processing, sensor interfacing and data processing, path planning and navigation algorithms and motor control. National Instruments' (NI) LabVIEW served as the programming language for software implementation. As an upgrade to last year's design, a NI compact Reconfigurable Input/Output system (cRIO) was incorporated to the system architecture. The cRIO is NI's solution for rapid prototyping that is equipped with a real time processor, an FPGA and modular input/output. Under the current system, the real time processor handles the path planning and navigation algorithms, the FPGA gathers and processes sensor data. This setup leaves the laptop to focus on running the image processing algorithm. Image processing as previously presented by Nepal et. al. is a multi-step line extraction algorithm and constitutes the largest processor load. This distributed approach results in a faster image processing algorithm which was previously Q's bottleneck. Additionally, the path planning and navigation algorithms are executed more reliably on the real time processor due to the deterministic nature of operation. The implementation of this architecture required exploration of various inter-system communication techniques. Data transfer between the laptop and the real time processor using UDP packets

Evaluating lane-by-lane gap-out based signal control for isolated intersection under stop-line, single and multiple advance detection systems

Directory of Open Access Journals (Sweden)

Chandan Keerthi Kancharla

2016-12-01

Full Text Available In isolated intersection’s actuated signal control, inductive loop detector layout plays a crucial role in providingthe vehicle information to the signal controller. Based on vehicle actuations at the detector, the green time is extended till a pre-defined threshold gap-out occurs. The Federal Highway Administration (FHWA proposed various guidelines for detec-tor layouts on low-speed and high-speed approaches. This paper proposes single and multiple advance detection schemes for low-speed traffic movements, that utilizes vehicle actuations from advance detectors located upstream of the stop-line, which are able to detect spill-back queues. The proposed detection schemes operate with actuated signal control based on lane-by-lane gap-out criteria. The performance of the proposed schemes is compared with FHWA’s stop-line and single advance detection schemes in the VISSIM simulation tool. Results have shown that the proposed single advance detection schemes showed improved performance in reducing travel time delay and average number of stops per vehicle under low volumes while the multiple advance detection scheme performed well under high volumes.

ANALYTICAL ESTIMATION OF MINIMUM AND MAXIMUM TIME EXPENDITURES OF PASSENGERS AT AN URBAN ROUTE STOP

Directory of Open Access Journals (Sweden)

Gorbachov, P.

2013-01-01

Full Text Available This scientific paper deals with the problem related to the definition of average time spent by passengers while waiting for transport vehicles at urban stops as well as the results of analytical modeling of this value at traffic schedule unknown to the passengers and of two options of the vehicle traffic management on the given route.

Standards and Specifications for Ground Processing of Space Vehicles: From an Aviation-Based Shuttle Project to Global Application

Science.gov (United States)

Ingalls, John; Cipolletti, John

2011-01-01

Proprietary or unique designs and operations are expected early in any industry's development, and often provide a competitive early market advantage. However, there comes a time when a product or industry requires standardization for the whole industry to advance...or survive. For the space industry, that time has come. Here, we will focus on standardization of ground processing for space vehicles and their ground systems. With the retirement of the Space Shuttle, and emergence of a new global space race, affordability and sustainability are more important now than ever. The growing commercialization of the space industry and current global economic environment are driving greater need for efficiencies to save time and money. More RLV's (Reusable Launch Vehicles) are being developed for the gains of reusability not achievable with traditional ELV's (Expendable Launch Vehicles). More crew/passenger vehicles are also being developed. All of this calls for more attention needed for ground processing-repeatedly before launch and after landing/recovery. RLV's should provide more efficiencies than ELV's, as long as MRO (Maintenance, Repair, and Overhaul) is well-planned-even for the unplanned problems. NASA's Space Shuttle is a primary example of an RLV which was supposed to thrive on reusability savings with efficient ground operations, but lessons learned show that costs were (and still are) much greater than expected. International standards and specifications can provide the commonality needed to simplify design and manufacturing as well as to improve safety, quality, maintenance, and operability. There are standards organizations engaged in the space industry, but ground processing is one of the areas least addressed. Challenges are encountered due to various factors often not considered during development. Multiple vehicle elements, sites, customers, and contractors pose various functional and integration difficulties. Resulting technical publication structures

M1078 Hybrid Hydraulic Vehicle Fuel Economy Evaluation

Science.gov (United States)

2012-09-01

hydraulic energy stored in the accumulators. Park Mechanism Not Required – Vehicle air brake system used to immobilize vehicle when parked – Same...power to the transmission to accelerate the vehicle forward and maintain a desired speed. For regenerative braking , the switching valve is set to...assist, brake energy recovery, dual mode braking ( regenerative and service brakes ), engine stop/start, silent watch mode, and stationary tool use

A study on model fidelity for model predictive control-based obstacle avoidance in high-speed autonomous ground vehicles

Science.gov (United States)

Liu, Jiechao; Jayakumar, Paramsothy; Stein, Jeffrey L.; Ersal, Tulga

2016-11-01

This paper investigates the level of model fidelity needed in order for a model predictive control (MPC)-based obstacle avoidance algorithm to be able to safely and quickly avoid obstacles even when the vehicle is close to its dynamic limits. The context of this work is large autonomous ground vehicles that manoeuvre at high speed within unknown, unstructured, flat environments and have significant vehicle dynamics-related constraints. Five different representations of vehicle dynamics models are considered: four variations of the two degrees-of-freedom (DoF) representation as lower fidelity models and a fourteen DoF representation with combined-slip Magic Formula tyre model as a higher fidelity model. It is concluded that the two DoF representation that accounts for tyre nonlinearities and longitudinal load transfer is necessary for the MPC-based obstacle avoidance algorithm in order to operate the vehicle at its limits within an environment that includes large obstacles. For less challenging environments, however, the two DoF representation with linear tyre model and constant axle loads is sufficient.

Optimal Control of Connected and Automated Vehicles at Roundabouts

Energy Technology Data Exchange (ETDEWEB)

Zhao, Liuhui [University of Delaware; Malikopoulos, Andreas [ORNL; Rios-Torres, Jackeline [ORNL

2018-01-01

Connectivity and automation in vehicles provide the most intriguing opportunity for enabling users to better monitor transportation network conditions and make better operating decisions to improve safety and reduce pollution, energy consumption, and travel delays. This study investigates the implications of optimally coordinating vehicles that are wirelessly connected to each other and to an infrastructure in roundabouts to achieve a smooth traffic flow without stop-and-go driving. We apply an optimization framework and an analytical solution that allows optimal coordination of vehicles for merging in such traffic scenario. The effectiveness of the efficiency of the proposed approach is validated through simulation and it is shown that coordination of vehicles can reduce total travel time by 3~49% and fuel consumption by 2~27% with respect to different traffic levels. In addition, network throughput is improved by up to 25% due to elimination of stop-and-go driving behavior.

Clamped seismic metamaterials: ultra-low frequency stop bands

International Nuclear Information System (INIS)

Achaoui, Y; Enoch, S; Guenneau, S; Antonakakis, T; Brûlé, S; Craster, R V

2017-01-01

The regularity of earthquakes, their destructive power, and the nuisance of ground vibration in urban environments, all motivate designs of defence structures to lessen the impact of seismic and ground vibration waves on buildings. Low frequency waves, in the range 1–10 Hz for earthquakes and up to a few tens of Hz for vibrations generated by human activities, cause a large amount of damage, or inconvenience; depending on the geological conditions they can travel considerable distances and may match the resonant fundamental frequency of buildings. The ultimate aim of any seismic metamaterial, or any other seismic shield, is to protect over this entire range of frequencies; the long wavelengths involved, and low frequency, have meant this has been unachievable to date. Notably this is scalable and the effects also hold for smaller devices in ultrasonics. There are three approaches to obtaining shielding effects: bragg scattering, locally resonant sub-wavelength inclusions and zero-frequency stop-band media. The former two have been explored, but the latter has not and is examined here. Elastic flexural waves, applicable in the mechanical vibrations of thin elastic plates, can be designed to have a broad zero-frequency stop-band using a periodic array of very small clamped circles. Inspired by this experimental and theoretical observation, all be it in a situation far removed from seismic waves, we demonstrate that it is possible to achieve elastic surface (Rayleigh) wave reflectors at very large wavelengths in structured soils modelled as a fully elastic layer periodically clamped to bedrock. We identify zero frequency stop-bands that only exist in the limit of columns of concrete clamped at their base to the bedrock. In a realistic configuration of a sedimentary basin 15 m deep we observe a zero frequency stop-band covering a broad frequency range of 0–30 Hz. (paper)

The Seismic Response of High-Speed Railway Bridges Subjected to Near-Fault Forward Directivity Ground Motions Using a Vehicle-Track-Bridge Element

Directory of Open Access Journals (Sweden)

Chen Ling-kun

2014-01-01

Full Text Available Based on the Next Generation Attenuation (NGA project ground motion library, the finite element model of the high-speed railway vehicle-bridge system is established. The model was specifically developed for such system that is subjected to near-fault ground motions. In addition, it accounted for the influence of the rail irregularities. The vehicle-track-bridge (VTB element is presented to simulate the interaction between train and bridge, in which a train can be modeled as a series of sprung masses concentrated at the axle positions. For the short period railway bridge, the results from the case study demonstrate that directivity pulse effect tends to increase the seismic responses of the bridge compared with far-fault ground motions or nonpulse-like motions and the directivity pulse effect and high values of the vertical acceleration component can notably influence the hysteretic behaviour of piers.

Where to locate transit stops: Cross-intersection profiles of ultrafine particles and implications for pedestrian exposure.

Science.gov (United States)

Choi, Wonsik; Ranasinghe, Dilhara; DeShazo, J R; Kim, Jae-Jin; Paulson, Suzanne E

2018-02-01

Epidemiological studies have shown that exposure to traffic-related pollutants increases incidence of adverse health outcomes. Transit users in cities across the globe commonly spend 15-45 min or more waiting at transit stops each day, often at locations with high levels of pollution from traffic. Here, we investigate the characteristics of concentration profiles of ultrafine particles (UFP) with 5 m spatial resolution across intersections, to determine the best place to site transit stops to minimize exposures. Cross-intersection UFP profiles were derived from 1744 profiles covering 90 m before and after each intersection center with a mobile monitoring platform. Measurements were made at 10 signalized intersections located at six urban sites, each with a distinct built environment, during both mornings and afternoons. Measurements were made within 1.5 m of the sidewalk and approximately at breathing height (1.5 m above ground level) to approximate sidewalk exposures. UFP profiles were strongly influenced by high emissions from vehicle stops and accelerations, and peaked within 30 m of intersection centers; from there concentrations decreased sharply with distance. Peak concentrations averaged about 90% higher than the minima along the block. They were accompanied by more frequent and larger transient concentration spikes, increasing the chance of people near the intersection being exposed to both short-term extremely high concentration spikes and higher average concentrations. The decays are somewhat larger before the intersection than after the intersection, however as siting transit stops after intersections is preferred for smooth traffic flow, we focus on after the intersection. Simple time-duration exposure calculations combined with breathing rates suggest moving a bus stop from 20 to 40-50 m after the intersection can reduce transit-users' exposure levels to total UFP substantially, in proportion to the reciprocal of the magnitude of elevation at

Online Aerial Terrain Mapping for Ground Robot Navigation

Directory of Open Access Journals (Sweden)

John Peterson

2018-02-01

Full Text Available This work presents a collaborative unmanned aerial and ground vehicle system which utilizes the aerial vehicle’s overhead view to inform the ground vehicle’s path planning in real time. The aerial vehicle acquires imagery which is assembled into a orthomosaic and then classified. These terrain classes are used to estimate relative navigation costs for the ground vehicle so energy-efficient paths may be generated and then executed. The two vehicles are registered in a common coordinate frame using a real-time kinematic global positioning system (RTK GPS and all image processing is performed onboard the unmanned aerial vehicle, which minimizes the data exchanged between the vehicles. This paper describes the architecture of the system and quantifies the registration errors between the vehicles.

Investigation of RADTRAN Stop Model input parameters for truck stops

International Nuclear Information System (INIS)

Griego, N.R.; Smith, J.D.; Neuhauser, K.S.

1996-01-01

RADTRAN is a computer code for estimating the risks and consequences as transport of radioactive materials (RAM). RADTRAN was developed and is maintained by Sandia National Laboratories for the US Department of Energy (DOE). For incident-free transportation, the dose to persons exposed while the shipment is stopped is frequently a major percentage of the overall dose. This dose is referred to as Stop Dose and is calculated by the Stop Model. Because stop dose is a significant portion of the overall dose associated with RAM transport, the values used as input for the Stop Model are important. Therefore, an investigation of typical values for RADTRAN Stop Parameters for truck stops was performed. The resulting data from these investigations were analyzed to provide mean values, standard deviations, and histograms. Hence, the mean values can be used when an analyst does not have a basis for selecting other input values for the Stop Model. In addition, the histograms and their characteristics can be used to guide statistical sampling techniques to measure sensitivity of the RADTRAN calculated Stop Dose to the uncertainties in the stop model input parameters. This paper discusses the details and presents the results of the investigation of stop model input parameters at truck stops

Constraint Embedding for Vehicle Suspension Dynamics

OpenAIRE

Jain Abhinandan; Kuo Calvin; Jayakumar Paramsothy; Cameron Jonathan

2016-01-01

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 ...

Real-time Accurate Surface Reconstruction Pipeline for Vision Guided Planetary Exploration Using Unmanned Ground and Aerial Vehicles

Science.gov (United States)

Almeida, Eduardo DeBrito

2012-01-01

This report discusses work completed over the summer at the Jet Propulsion Laboratory (JPL), California Institute of Technology. A system is presented to guide ground or aerial unmanned robots using computer vision. The system performs accurate camera calibration, camera pose refinement and surface extraction from images collected by a camera mounted on the vehicle. The application motivating the research is planetary exploration and the vehicles are typically rovers or unmanned aerial vehicles. The information extracted from imagery is used primarily for navigation, as robot location is the same as the camera location and the surfaces represent the terrain that rovers traverse. The processed information must be very accurate and acquired very fast in order to be useful in practice. The main challenge being addressed by this project is to achieve high estimation accuracy and high computation speed simultaneously, a difficult task due to many technical reasons.

76 FR 53660 - Federal Motor Vehicle Safety Standards; Seat Belt Assemblies

Science.gov (United States)

2011-08-29

... Traffic Safety Administration 49 CFR Part 571 [Docket No. NHTSA-2011-0078] Federal Motor Vehicle Safety... integration of electrical signals from vehicle crash sensors would work with the requested mechanical seat... (350,000) of the vehicles were stopped in the traffic lane prior to the crash event (pg. 22, Table 7...

Vehicle Test Facilities at Aberdeen Proving Ground

Science.gov (United States)

1981-07-06

warehouse and rough terrain forklifts. Two 5-ton-capacity manual chain hoists at the rear of the table regulate its slope from 0 to 40 percent. The overall...Capacity at 24-Inch Load Center. 5. TOP/ HTP 2-2-608, Braking, Wheeled Vehicles, 15 Jav.&ry 1971. 6. TOP 2-2-603, Vehicle Fuel Consumption, 1 November 1977. A-1 r -. ’,’

Intercomparison of unmanned aerial vehicle and ground-based narrow band spectrometers applied to crop trait monitoring in organic potato production

NARCIS (Netherlands)

Domingues Franceschini, Marston; Bartholomeus, Harm; Apeldoorn, van Dirk; Suomalainen, Juha; Kooistra, Lammert

2017-01-01

Vegetation properties can be estimated using optical sensors, acquiring data on board of different platforms. For instance, ground-based and Unmanned Aerial Vehicle (UAV)-borne spectrometers can measure reflectance in narrow spectral bands, while different modelling approaches, like regressions

Predicting crash-relevant violations at stop sign-controlled intersections for the development of an intersection driver assistance system.

Science.gov (United States)

Scanlon, John M; Sherony, Rini; Gabler, Hampton C

2016-09-01

Intersection crashes resulted in over 5,000 fatalities in the United States in 2014. Intersection Advanced Driver Assistance Systems (I-ADAS) are active safety systems that seek to help drivers safely traverse intersections. I-ADAS uses onboard sensors to detect oncoming vehicles and, in the event of an imminent crash, can either alert the driver or take autonomous evasive action. The objective of this study was to develop and evaluate a predictive model for detecting whether a stop sign violation was imminent. Passenger vehicle intersection approaches were extracted from a data set of typical driver behavior (100-Car Naturalistic Driving Study) and violations (event data recorders downloaded from real-world crashes) and were assigned weighting factors based on real-world frequency. A k-fold cross-validation procedure was then used to develop and evaluate 3 hypothetical stop sign warning algorithms (i.e., early, intermediate, and delayed) for detecting an impending violation during the intersection approach. Violation detection models were developed using logistic regression models that evaluate likelihood of a violation at various locations along the intersection approach. Two potential indicators of driver intent to stop-that is, required deceleration parameter (RDP) and brake application-were used to develop the predictive models. The earliest violation detection opportunity was then evaluated for each detection algorithm in order to (1) evaluate the violation detection accuracy and (2) compare braking demand versus maximum braking capabilities. A total of 38 violating and 658 nonviolating approaches were used in the analysis. All 3 algorithms were able to detect a violation at some point during the intersection approach. The early detection algorithm, as designed, was able to detect violations earlier than all other algorithms during the intersection approach but gave false alarms for 22.3% of approaches. In contrast, the delayed detection algorithm sacrificed

Automated mixed traffic vehicle control and scheduling study

Science.gov (United States)

Peng, T. K. C.; Chon, K.

1976-01-01

The operation and the expected performance of a proposed automatic guideway transit system which uses low speed automated mixed traffic vehicles (AMTVs) were analyzed. Vehicle scheduling and headway control policies were evaluated with a transit system simulation model. The effect of mixed traffic interference on the average vehicle speed was examined with a vehicle pedestrian interface model. Control parameters regulating vehicle speed were evaluated for safe stopping and passenger comfort. Some preliminary data on the cost and operation of an experimental AMTV system are included. These data were the result of a separate task conducted at JPL, and were included as background information.

Heavy and Overweight Vehicle Brake Testing: Five-Axle Combination Tractor-Flatbed Final Report

Energy Technology Data Exchange (ETDEWEB)

Lascurain, Mary Beth [ORNL; Capps, Gary J [ORNL; Franzese, Oscar [ORNL

2013-10-01

The Federal Motor Carrier Safety Administration, in coordination with the Federal Highway Administration, sponsored the Heavy and Overweight Vehicle Brake Testing (HOVBT) program in order to provide information about the effect of gross vehicle weight (GVW) on braking performance. Because the Federal Motor Carrier Safety Regulations limit the number of braking system defects that may exist for a vehicle to be allowed to operate on the roadways, the examination of the effect of brake defects on brake performance for increased loads is also relevant. The HOVBT program seeks to provide relevant information to policy makers responsible for establishing load limits, beginning with providing test data for a combination tractor/trailer. This testing was conducted on a five-axle combination vehicle with tractor brakes meeting the Reduced Stopping Distance requirement rulemaking. This report provides a summary of the testing activities, the results of various analyses of the data, and recommendations for future research. Following a complete brake rebuild, instrumentation, and brake burnish, stopping tests were performed from 20 and 40 mph with various brake application pressures (15 psi, 25 psi, 35 psi, 45 psi, 55 psi, and full system pressure). These tests were conducted for various brake conditions at the following GVWs: 60,000, 80,000, 91,000, 97,000, 106,000, and 116,000 lb. The 80,000-lb GVWs included both balanced and unbalanced loads. The condition of the braking system was also varied. To introduce these defects, brakes (none, forward drive axle, or rear trailer axle) were made inoperative. In addition to the stopping tests, performance-based brake tests were conducted for the various loading and brake conditions. Analysis of the stopping test data showed the stopping distance to increase with load (as expected) and also showed that more braking force was generated by the drive axle brakes than the trailer axle brakes. The constant-pressure stopping test data

Integrated vehicle control and guidance systems in unmanned ground vehicles for commercial applications

Science.gov (United States)

Kenyon, Chase H.

1995-01-01

While there is a lot of recent development in the entire IVHS field, very few have had the opportunity to combine the many areas of development into a single integrated `intelligent' unmanned vehicle. One of our systems was developed specifically to serve a major automobile manufacturer's need for an automated vehicle chassis durability test facility. Due to the severity of the road surface human drivers could not be used. A totally automated robotic vehicle driver and guidance system was necessary. In order to deliver fixed price commercial projects now, it was apparent system and component costs were of paramount importance. Cyplex has developed a robust, cost effective single wire guidance system. This system has inherent advantages in system simplicity. Multi-signal (per vehicle lane) systems complicate path planning and layout when multiple lanes and lane changes are required, as on actual highways. The system has demonstrated high enough immunity to rain and light snow cover that normal safety reductions in speed are adequate to stay within the required system performance envelope. This system and it's antenna interface have shown the ability to guide the vehicle at slow speeds (10 MPH) with a tracking repeatability of plus or minus 1/8 of an inch. The basic guide and antenna system has been tested at speeds up to 80 mph. The system has inherently superior abilities for lane changes and precision vehicle placement. The operation of this system will be described and the impact of a system that is commercially viable now for highway and off road use will be discussed.

76 FR 55859 - Federal Motor Vehicle Safety Standards No. 121; Air Brake Systems

Science.gov (United States)

2011-09-09

... during road tests for the braking system, a vehicle equipped with an interlocking axle system or a front... vehicle braking systems, tire characteristics related to lateral force and longitudinal force generation... stopping distance without activating the ABS system by braking the vehicle so that the brake pressure is...

Performance of an Automated-Mixed-Traffic-Vehicle /AMTV/ System. [urban people mover

Science.gov (United States)

Peng, T. K. C.; Chon, K.

1978-01-01

This study analyzes the operation and evaluates the expected performance of a proposed automatic guideway transit system which uses low-speed Automated Mixed Traffic Vehicles (AMTV's). Vehicle scheduling and headway control policies are evaluated with a transit system simulation model. The effect of mixed-traffic interference on the average vehicle speed is examined with a vehicle-pedestrian interface model. Control parameters regulating vehicle speed are evaluated for safe stopping and passenger comfort.

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.

Simulation of Ground Winds Time Series for the NASA Crew Launch Vehicle (CLV)

Science.gov (United States)

Adelfang, Stanley I.

2008-01-01

Simulation of wind time series based on power spectrum density (PSD) and spectral coherence models for ground wind turbulence is described. The wind models, originally developed for the Shuttle program, are based on wind measurements at the NASA 150-m meteorological tower at Cape Canaveral, FL. The current application is for the design and/or protection of the CLV from wind effects during on-pad exposure during periods from as long as days prior to launch, to seconds or minutes just prior to launch and seconds after launch. The evaluation of vehicle response to wind will influence the design and operation of constraint systems for support of the on-pad vehicle. Longitudinal and lateral wind component time series are simulated at critical vehicle locations. The PSD model for wind turbulence is a function of mean wind speed, elevation and temporal frequency. Integration of the PSD equation over a selected frequency range yields the variance of the time series to be simulated. The square root of the PSD defines a low-pass filter that is applied to adjust the components of the Fast Fourier Transform (FFT) of Gaussian white noise. The first simulated time series near the top of the launch vehicle is the inverse transform of the adjusted FFT. Simulation of the wind component time series at the nearest adjacent location (and all other succeeding next nearest locations) is based on a model for the coherence between winds at two locations as a function of frequency and separation distance, where the adjacent locations are separated vertically and/or horizontally. The coherence function is used to calculate a coherence weighted FFT of the wind at the next nearest location, given the FFT of the simulated time series at the previous location and the essentially incoherent FFT of the wind at the selected location derived a priori from the PSD model. The simulated time series at each adjacent location is the inverse Fourier transform of the coherence weighted FFT. For a selected

33 CFR 127.311 - Motor vehicles.

Science.gov (United States)

2010-07-01

...) WATERFRONT FACILITIES WATERFRONT FACILITIES HANDLING LIQUEFIED NATURAL GAS AND LIQUEFIED HAZARDOUS GAS Waterfront Facilities Handling Liquefied Natural Gas Operations § 127.311 Motor vehicles. (a) The operator... storage tank or loading flange. (b) During transfer operations, no person may— (1) Stop or park a motor...

Stop and Restart Effects on Modern Vehicle Starting System Components

Energy Technology Data Exchange (ETDEWEB)

Windover, Paul R. [Argonne National Lab. (ANL), Argonne, IL (United States); Owens, Russell J. [Argonne National Lab. (ANL), Argonne, IL (United States); Levinson, Terry M. [Argonne National Lab. (ANL), Argonne, IL (United States); Laughlin, Michael [Argonne National Lab. (ANL), Argonne, IL (United States); Gaines, Linda [Argonne National Lab. (ANL), Argonne, IL (United States)

2015-01-01

Many drivers of personal and commercial vehicles believe that turning the vehicle off and on frequently instead of idling will cause premature wear of the starter system (starter motor and starter battery). As a result, they are concerned that the replacement cost of the starter motor and/or battery due to increased manual engine cycling would be more than the cumulative cost of the fuel saved by not idling unnecessarily. A number of variables play a role in addressing this complex concern, including the number of starting cycles per day, the time between starting cycles, the intended design life of the starting system, the amount of fuel used to restart an engine, and the cumulative cost of the saved fuel. Qualitative and quantitative information from a variety of sources was used to develop a life-cycle economic model to evaluate the cost and quantify the realistic factors that are related to the permissible frequency of starter motor cycles for the average vehicle to economically minimize engine idle time. Annual cost savings can be calculated depending on shutdown duration and the number of shutdown cycles per day. Analysis shows that cost savings are realized by eliminating idling exceeding one minute by shutting down the engine and restarting it. For a typical motorist, the damage to starting system components resulting from additional daily start cycles will be negligible. Overall, it was found that starter life is mostly dependent on the total number of start cycles, while battery life is more dependent on ensuring a full charge between start events.

Ground Vehicle Power and Mobility Overview - Germany Visit

Science.gov (United States)

2011-11-10

the current and future force Survivability Robotics – Intelligent Systems Vehicle Electronics & Architecture Fuel, Water, Bridging ...Test Cell • Engine Generator Test Lab • Full Vehicle Environmental Test Cell • Hybrid Electric Reconfigurable Moveable Integration Testbed (HERMIT...Converter Conducted competitive runoff evaluations on Bridging Boat engine candidates Completed independent durability assessment of OEM

The effects of 2 landing techniques on knee kinematics, kinetics, and performance during stop-jump and side-cutting tasks.

Science.gov (United States)

Dai, Boyi; Garrett, William E; Gross, Michael T; Padua, Darin A; Queen, Robin M; Yu, Bing

2015-02-01

Anterior cruciate ligament injuries (ACL) commonly occur during jump landing and cutting tasks. Attempts to land softly and land with greater knee flexion are associated with decreased ACL loading. However, their effects on performance are unclear. Attempts to land softly will decrease peak posterior ground-reaction force (PPGRF) and knee extension moment at PPGRF compared with a natural landing during stop-jump and side-cutting tasks. Attempts to land with greater knee flexion at initial ground contact will increase knee flexion at PPGRF compared with a natural landing during both tasks. In addition, both landing techniques will increase stance time and lower extremity mechanical work as well as decrease jump height and movement speed compared with a natural landing during both tasks. Controlled laboratory study. A total of 18 male and 18 female recreational athletes participated in the study. Three-dimensional kinematic and kinetic data were collected during stop-jump and side-cutting tasks under 3 conditions: natural landing, soft landing, and landing with greater knee flexion at initial ground contact. Attempts to land softly decreased PPGRF and knee extension moment at PPGRF compared with a natural landing during stop-jump tasks. Attempts to land softly decreased PPGRF compared with a natural landing during side-cutting tasks. Attempts to land with greater knee flexion at initial ground contact increased knee flexion angle at PPGRF compared with a natural landing during both stop-jump and side-cutting tasks. Attempts to land softly and land with greater knee flexion at initial ground contact increased stance time and lower extremity mechanical work, as well as decreased jump height and movement speed during both stop-jump and side-cutting tasks. Although landing softly and landing with greater knee flexion at initial ground contact may reduce ACL loading during stop-jump and side-cutting tasks, the performance of these tasks decreased, as indicated by

Modelling and Simulation of Cooperative Control for Bus Rapid Transit Vehicle Platoon in a Connected Vehicle Environment

Directory of Open Access Journals (Sweden)

Jiahui Liu

2017-02-01

Full Text Available The aim of this paper is to develop a cooperative control model for improving the operational efficiency of Bus Rapid Transit (BRT vehicles. The model takes advantage of the emerging connected vehicle technology. A connected vehicle centre is established to assign a specific reservation time interval and transmit the corresponding dynamic speed guidance to each BRT vehicle. Furthermore, a set of constraints have been set up to avoid bus queuing and waiting phenomena in downstream BRT stations. Therefore, many BRT vehicles are strategically guided to form a platoon, which can pass through an intersection with no impedance. An actual signalized intersection along the Guangzhou BRT corridor is employed to verify and assess the cooperative control model in various traffic conditions. The simulation-based evaluation results demonstrate that the proposed approach can reduce delays, decrease the number of stops, and improve the sustainability of the BRT vehicles.

Stability control for high speed tracked unmanned vehicles

Science.gov (United States)

Pape, Olivier; Morillon, Joel G.; Houbloup, Philippe; Leveque, Stephane; Fialaire, Cecile; Gauthier, Thierry; Ropars, Patrice

2005-05-01

The French Military Robotic Study Program (introduced in Aerosense 2003), sponsored by the French Defense Procurement Agency and managed by Thales as the prime contractor, focuses on about 15 robotic themes which can provide an immediate "operational add-on value". The paper details the "automatic speed adjustment" behavior (named SYR4), developed by Giat Industries Company, which main goal is to secure the teleoperated mobility of high speed tracked vehicles on rough grounds; more precisely, the validated low level behavior continuously adjusts the vehicle speed taking into account the teleperator wish AND the maximum speed that the vehicle can manage safely according to the commanded radius of curvature. The algorithm is based on a realistic physical model of the ground-tracks relation, taking into account many vehicle and ground parameters (such as ground adherence and dynamic specificities of tracked vehicles). It also deals with the teleoperator-machine interface, providing a balanced strategy between both extreme behaviors: a) maximum speed reduction before initiating the commanded curve; b) executing the minimum possible radius without decreasing the commanded speed. The paper presents the results got from the military acceptance tests performed on tracked SYRANO vehicle (French Operational Demonstrator).

Second stop and sbottom searches with a stealth stop

Energy Technology Data Exchange (ETDEWEB)

Cheng, Hsin-Chia; Li, Lingfeng; Qin, Qin [Department of Physics, University of California,Davis, California 95616 (United States)

2016-11-29

The top squarks (stops) may be the most wanted particles after the Higgs boson discovery. The searches for the lightest stop have put strong constraints on its mass. However, there is still a search gap in the low mass region if the spectrum of the stop and the lightest neutralino is compressed. In that case, it may be easier to look for the second stop since naturalness requires both stops to be close to the weak scale. The current experimental searches for the second stop are based on the simplified model approach with the decay modes t̃{sub 2}→t̃{sub 1}Z and t̃{sub 2}→t̃{sub 1}h. However, in a realistic supersymmetric spectrum there is always a sbottom lighter than the second stop, hence the decay patterns are usually more complicated than the simplified model assumptions. In particular, there are often large branching ratios of the decays t̃{sub 2}→b̃{sub 1}W and b̃{sub 1}→t̃{sub 1}W as long as they are open. The decay chains can be even more complex if there are intermediate states of additional charginos and neutralinos in the decays. By studying several MSSM benchmark models at the 14 TeV LHC, we point out the importance of the multi-W final states in the second stop and the sbottom searches, such as the same-sign dilepton and multilepton signals, aside from the traditional search modes. The observed same-sign dilepton excesses at LHC Run 1 and Run 2 may be explained by some of our benchmark models. We also suggest that the vector boson tagging and a new kinematic variable may help to suppress the backgrounds and increase the signal significance for some search channels. Due to the complex decay patterns and lack of the dominant decay channels, the best reaches likely require a combination of various search channels at the LHC for the second stop and the lightest sbottom.

Stashing the stops in multijet events at the LHC

Science.gov (United States)

Diglio, Sara; Feligioni, Lorenzo; Moultaka, Gilbert

2017-09-01

While the presence of a light stop is increasingly disfavored by the experimental limits set on R-parity conserving scenarios, the naturalness of supersymmetry could still be safely concealed in the more challenging final states predicted by the existence of non-null R-parity violating couplings. Although R-parity violating signatures are extensively looked for at the Large Hadron Collider, these searches mostly assume 100% branching ratios for the direct decays of supersymmetric particles into Standard Model ones. In this paper we scrutinize the implications of relaxing this assumption by focusing on one motivated scenario where the lightest stop is heavier than a chargino and a neutralino. Considering a class of R-parity baryon number violating couplings, we show on general grounds that while the direct decay of the stop into Standard Model particles is dominant for large values of these couplings, smaller values give rise, instead, to the dominance of a plethora of longer decay chains and richer final states that have been so far barely analyzed at the LHC, thus weakening the impact of the present experimental stop mass limits. We characterize the case for R-parity baryon number violating couplings in the 10-7-10-1 range, in two different benchmark points scenarios within the model-independent setting of the low-energy phenomenological Minimal Supersymmetric Standard Model. We identify the different relevant experimental signatures from stop pair production and decays, estimate the corresponding proton-proton cross sections at √{s }=14 TeV and discuss signal versus background issues.

High-Throughput Phenotyping of Plant Height: Comparing Unmanned Aerial Vehicles and Ground LiDAR Estimates.

Science.gov (United States)

Madec, Simon; Baret, Fred; de Solan, Benoît; Thomas, Samuel; Dutartre, Dan; Jezequel, Stéphane; Hemmerlé, Matthieu; Colombeau, Gallian; Comar, Alexis

2017-01-01

The capacity of LiDAR and Unmanned Aerial Vehicles (UAVs) to provide plant height estimates as a high-throughput plant phenotyping trait was explored. An experiment over wheat genotypes conducted under well watered and water stress modalities was conducted. Frequent LiDAR measurements were performed along the growth cycle using a phénomobile unmanned ground vehicle. UAV equipped with a high resolution RGB camera was flying the experiment several times to retrieve the digital surface model from structure from motion techniques. Both techniques provide a 3D dense point cloud from which the plant height can be estimated. Plant height first defined as the z -value for which 99.5% of the points of the dense cloud are below. This provides good consistency with manual measurements of plant height (RMSE = 3.5 cm) while minimizing the variability along each microplot. Results show that LiDAR and structure from motion plant height values are always consistent. However, a slight under-estimation is observed for structure from motion techniques, in relation with the coarser spatial resolution of UAV imagery and the limited penetration capacity of structure from motion as compared to LiDAR. Very high heritability values ( H 2 > 0.90) were found for both techniques when lodging was not present. The dynamics of plant height shows that it carries pertinent information regarding the period and magnitude of the plant stress. Further, the date when the maximum plant height is reached was found to be very heritable ( H 2 > 0.88) and a good proxy of the flowering stage. Finally, the capacity of plant height as a proxy for total above ground biomass and yield is discussed.

Grotius’ Imago Dei anthropology: grounding Ius naturae et gentium

NARCIS (Netherlands)

Nijman, J.E.; Koskenniemi, M.; García-Salmones Rovira, M.; Amorosa, P.

2017-01-01

In the standard account Hugo Grotius secularized international law by grounding it on human nature. This chapter argues we should not stop at the standard account, but rather should dig deeper and examine the theological anthropology grounding Grotius’ ideas on the law of nature and nations. With

Grotius' imago Dei anthropology: Grounding Ius naturae et gentium

NARCIS (Netherlands)

Nijman, J.

2015-01-01

The standard account has it that Hugo Grotius secularised international law by grounding it on human nature. This chapter argues we should not stop at the standard account, but rather should dig deeper and examine the theological anthropology grounding Grotius’ ideas on the law of nature and

Method of Controlling Steering of a Ground Vehicle

Science.gov (United States)

Dawson, Andrew D. (Inventor); Bluethmann, William J. (Inventor); Lee, Chunhao J. (Inventor); Vitale, Robert L. (Inventor); Guo, Raymond (Inventor); Atluri, Venkata Prasad (Inventor)

2016-01-01

A method of controlling steering of a vehicle through setting wheel angles of a plurality of modular electronic corner assemblies (eModules) is provided. The method includes receiving a driving mode selected from a mode selection menu. A position of a steering input device is determined in a master controller. A velocity of the vehicle is determined, in the master controller, when the determined position of the steering input device is near center. A drive mode request corresponding to the selected driving mode to the plurality of steering controllers is transmitted to the master controller. A required steering angle of each of the plurality of eModules is determined, in the master controller, as a function of the determined position of the steering input device, the determined velocity of the vehicle, and the selected first driving mode. The eModules are set to the respective determined steering angles.

Vehicle model for tyre-ground contact force evaluation

OpenAIRE

Jiao, Lejia

2013-01-01

Economic development and growing integration process of world trade increases the demand for road transport. In 2008, the freight transportation by road in Sweden reached 42 million tonne-kilometers. Sweden has a tradition of long and heavy trucks combinations. Lots of larger vehicles, with a maximum length of 25.25 meters and weight of 60 tonnes, are used in national traffic. Heavier road transport and widely use of large vehicles contribute to the damages of pavement. According to a recent ...

Drivers' smart advisory system improves driving performance at STOP sign intersections

Directory of Open Access Journals (Sweden)

Qing Li

2017-06-01

Full Text Available STOP signs are often physically blocked by obstacles at the corner, forming a safety threat. To enhance the safety at an un-signalized intersection like a STOP sign intersection, a radio frequency identification (RFID based drivers smart advisory system (DSAS was developed, which provides drivers with an earlier warning message when they are approaching an un-signalized intersection. In this research, a pilot field test was conducted with the DSAS alarm on an approach towards a STOP sign intersection in a residential area in Houston, Texas. The designed test route covers all turning movements, including left turn, through movement, and right turn. GPS units recorded test drivers' driving behaviors. A self-developed MATLAB program and statistically significant difference t-test were applied to analyze the impacts of the DSAS messages on drivers' driving performance, in terms of approaching speed profile, acceleration/deceleration rates, braking distance, and possible extra vehicle emissions induced by the introduction of the DSAS message. Drivers' preference on the DSAS was investigated by a designed survey questionnaire among test drivers. Results showed that the DSAS alarm was able to induce drivers to drive significantly slower to approach a STOP sign intersection, perform smaller fluctuation in acceleration/deceleration rates, and be more aware of a coming STOP sign indicated by decelerating earlier. All test drivers preferred to follow the DSAS alarm on roads for a safety concern. Further, the DSAS alarm caused the reduction in emission rates through movement. For a general observation, more road tests with more participants and different test routes were recommended.

Research of Obstacle Recognition Technology in Cross-Country Environment for Unmanned Ground Vehicle

Directory of Open Access Journals (Sweden)

Zhao Yibing

2014-01-01

Full Text Available Being aimed at the obstacle recognition problem of unmanned ground vehicles in cross-country environment, this paper uses monocular vision sensor to realize the obstacle recognition of typical obstacles. Firstly, median filtering algorithm is applied during image preprocessing that can eliminate the noise. Secondly, image segmentation method based on the Fisher criterion function is used to segment the region of interest. Then, morphological method is used to process the segmented image, which is preparing for the subsequent analysis. The next step is to extract the color feature S, color feature a and edge feature “verticality” of image are extracted based on the HSI color space, the Lab color space, and two value images. Finally multifeature fusion algorithm based on Bayes classification theory is used for obstacle recognition. Test results show that the algorithm has good robustness and accuracy.

Vehicle barrier with access delay

Science.gov (United States)

Swahlan, David J; Wilke, Jason

2013-09-03

An access delay vehicle barrier for stopping unauthorized entry into secure areas by a vehicle ramming attack includes access delay features for preventing and/or delaying an adversary from defeating or compromising the barrier. A horizontally deployed barrier member can include an exterior steel casing, an interior steel reinforcing member and access delay members disposed within the casing and between the casing and the interior reinforcing member. Access delay members can include wooden structural lumber, concrete and/or polymeric members that in combination with the exterior casing and interior reinforcing member act cooperatively to impair an adversarial attach by thermal, mechanical and/or explosive tools.

Emissions from US waste collection vehicles

International Nuclear Information System (INIS)

Maimoun, Mousa A.; Reinhart, Debra R.; Gammoh, Fatina T.; McCauley Bush, Pamela

2013-01-01

Highlights: ► Life-cycle emissions for alternative fuel technologies. ► Fuel consumption of alternative fuels for waste collection vehicles. ► Actual driving cycle of waste collection vehicles. ► Diesel-fueled waste collection vehicle emissions. - Abstract: This research is an in-depth environmental analysis of potential alternative fuel technologies for waste collection vehicles. Life-cycle emissions, cost, fuel and energy consumption were evaluated for a wide range of fossil and bio-fuel technologies. Emission factors were calculated for a typical waste collection driving cycle as well as constant speed. In brief, natural gas waste collection vehicles (compressed and liquid) fueled with North-American natural gas had 6–10% higher well-to-wheel (WTW) greenhouse gas (GHG) emissions relative to diesel-fueled vehicles; however the pump-to-wheel (PTW) GHG emissions of natural gas waste collection vehicles averaged 6% less than diesel-fueled vehicles. Landfill gas had about 80% lower WTW GHG emissions relative to diesel. Biodiesel waste collection vehicles had between 12% and 75% lower WTW GHG emissions relative to diesel depending on the fuel source and the blend. In 2011, natural gas waste collection vehicles had the lowest fuel cost per collection vehicle kilometer travel. Finally, the actual driving cycle of waste collection vehicles consists of repetitive stops and starts during waste collection; this generates more emissions than constant speed driving

Instantaneous emission modeling with GPS-based vehicle activity data: results of diesel trucks for one-day trips

NARCIS (Netherlands)

Feng, T.; Arentze, T.A.; Timmermans, H.J.P.

2011-01-01

This paper presents an instantaneous analysis for traffic emissions using GPS-based vehicle activity data. The different driving conditions, including real-time and average speed, short-time stops and long-time stops, acceleration and deceleration, etc., are extracted from GPS data. The hot

Vehicle speed guidance strategy at signalized intersection based on cooperative vehicle infrastructure system

Directory of Open Access Journals (Sweden)

Fengyuan JIA

2017-10-01

Full Text Available In order to reduce stopping time of vehicle at a signalized intersection, aiming at the difficulty, even the impossibility to obtain real-time queue length of intersection in third and fourth-tier cities in China sometimes, a speed guidance strategy based on cooperative vehicle infrastructure system is put forward and studied. For validating the strategy, the traffic signal timing data of the intersection at Hengshan Road and North Fengming Lake Road in Wuhu is collected by a vehicular traffic signal reminder system which is designed. The simulation experiments using the acquired data are done by software VISSIM. The simulation results demonstrate that the strategy under high and low traffic flow can effectively decrease the link travel-time, reducing average ratio is 9.2 % and 13.0 %, respectively, and the effect under low traffic flow is better than that under high traffic flow. The strategy improves efficiency of traffic at a signalized intersection and provides an idea for the application of vehicle speed guidance based on cooperative vehicle infrastructure system.

76 FR 48758 - 2017-2025 Model Year Light-Duty Vehicle GHG Emissions and CAFE Standards: Supplemental Notice of...

Science.gov (United States)

2011-08-09

... definitions of mild and strong HEV pickup trucks, but expect to include stop/start, regenerative braking... (light-duty vehicles) built in those model years. Together, these vehicle categories, which include... provides the opportunity to begin to transform the most challenging category of vehicles in terms of the...

Near-term electric test vehicle ETV-2. Phase II. Final report

Energy Technology Data Exchange (ETDEWEB)

1981-04-01

A unique battery-powered passenger vehicle has been developed that provides a significant improvement over conventional electric vehicle performance, particularly during stop-and-go driving. The vehicle is unique in two major respects: (1) the power system incorporates a flywheel that stores energy during regenerative braking and makes possible the acceleration capability needed to keep up with traffic without reducing range to unacceptable values; and (2) lightweight plastic materials are used for the vehicle unibody to minimize weight and increase range. These features were analyzed and demonstrated in an electric test vehicle, ETV-2. Characteristics of this vehicle are summarized. Information is presented on: vehicle design, fabrication, safety testing, and performance testing; power system design and operation; flywheel; battery pack performance; and controls and electronic equipment. (LCL)

76 FR 77183 - Federal Motor Vehicle Safety Standards; Theft Protection and Rollaway Prevention

Science.gov (United States)

2011-12-12

... stress and confusion relating to fundamental differences in how one operates a vehicle. This is... that are used to stop the vehicle engine or other propulsion system and that do not involve the use of...: Attempts to shut down the propulsion system without first moving the gear selection control to the ``park...

Does assisted driving behavior lead to safety-critical encounters with unequipped vehicles' drivers?

Science.gov (United States)

Preuk, Katharina; Stemmler, Eric; Schießl, Caroline; Jipp, Meike

2016-10-01

With Intelligent Transport Systems (e.g., traffic light assistance systems) assisted drivers are able to show driving behavior in anticipation of upcoming traffic situations. In the years to come, the penetration rate of such systems will be low. Therefore, the majority of vehicles will not be equipped with these systems. Unequipped vehicles' drivers may not expect the driving behavior of assisted drivers. However, drivers' predictions and expectations can play a significant role in their reaction times. Thus, safety issues could arise when unequipped vehicles' drivers encounter driving behavior of assisted drivers. This is why we tested how unequipped vehicles' drivers (N=60) interpreted and reacted to the driving behavior of an assisted driver. We used a multi-driver simulator with three drivers. The three drivers were driving in a line. The lead driver in the line was a confederate who was followed by two unequipped vehicles' drivers. We varied the equipment of the confederate with an Intelligent Transport System: The confederate was equipped either with or without a traffic light assistance system. The traffic light assistance system provided a start-up maneuver before a light turned green. Therefore, the assisted confederate seemed to show unusual deceleration behavior by coming to a halt at an unusual distance from the stop line at the red traffic light. The unusual distance was varied as we tested a moderate (4m distance from the stop line) and an extreme (10m distance from the stop line) parameterization of the system. Our results showed that the extreme parametrization resulted in shorter minimal time-to-collision of the unequipped vehicles' drivers. One rear-end crash was observed. These results provided initial evidence that safety issues can arise when unequipped vehicles' drivers encounter assisted driving behavior. We recommend that future research identifies counteractions to prevent these safety issues. Moreover, we recommend that system developers

Figure-ground representation and its decay in primary visual cortex.

Science.gov (United States)

Strother, Lars; Lavell, Cheryl; Vilis, Tutis

2012-04-01

We used fMRI to study figure-ground representation and its decay in primary visual cortex (V1). Human observers viewed a motion-defined figure that gradually became camouflaged by a cluttered background after it stopped moving. V1 showed positive fMRI responses corresponding to the moving figure and negative fMRI responses corresponding to the static background. This positive-negative delineation of V1 "figure" and "background" fMRI responses defined a retinotopically organized figure-ground representation that persisted after the figure stopped moving but eventually decayed. The temporal dynamics of V1 "figure" and "background" fMRI responses differed substantially. Positive "figure" responses continued to increase for several seconds after the figure stopped moving and remained elevated after the figure had disappeared. We propose that the sustained positive V1 "figure" fMRI responses reflected both persistent figure-ground representation and sustained attention to the location of the figure after its disappearance, as did subjects' reports of persistence. The decreasing "background" fMRI responses were relatively shorter-lived and less biased by spatial attention. Our results show that the transition from a vivid figure-ground percept to its disappearance corresponds to the concurrent decay of figure enhancement and background suppression in V1, both of which play a role in form-based perceptual memory.

Unmanned Ground Vehicle Perception Using Thermal Infrared Cameras

Science.gov (United States)

Rankin, Arturo; Huertas, Andres; Matthies, Larry; Bajracharya, Max; Assad, Christopher; Brennan, Shane; Bellutta, Paolo; Sherwin, Gary W.

2011-01-01

The ability to perform off-road autonomous navigation at any time of day or night is a requirement for some unmanned ground vehicle (UGV) programs. Because there are times when it is desirable for military UGVs to operate without emitting strong, detectable electromagnetic signals, a passive only terrain perception mode of operation is also often a requirement. Thermal infrared (TIR) cameras can be used to provide day and night passive terrain perception. TIR cameras have a detector sensitive to either mid-wave infrared (MWIR) radiation (3-5?m) or long-wave infrared (LWIR) radiation (8-12?m). With the recent emergence of high-quality uncooled LWIR cameras, TIR cameras have become viable passive perception options for some UGV programs. The Jet Propulsion Laboratory (JPL) has used a stereo pair of TIR cameras under several UGV programs to perform stereo ranging, terrain mapping, tree-trunk detection, pedestrian detection, negative obstacle detection, and water detection based on object reflections. In addition, we have evaluated stereo range data at a variety of UGV speeds, evaluated dual-band TIR classification of soil, vegetation, and rock terrain types, analyzed 24 hour water and 12 hour mud TIR imagery, and analyzed TIR imagery for hazard detection through smoke. Since TIR cameras do not currently provide the resolution available from megapixel color cameras, a UGV's daytime safe speed is often reduced when using TIR instead of color cameras. In this paper, we summarize the UGV terrain perception work JPL has performed with TIR cameras over the last decade and describe a calibration target developed by General Dynamics Robotic Systems (GDRS) for TIR cameras and other sensors.

Modeling Human Steering Behavior During Path Following in Teleoperation of Unmanned Ground Vehicles.

Science.gov (United States)

Mirinejad, Hossein; Jayakumar, Paramsothy; Ersal, Tulga

2018-04-01

This paper presents a behavioral model representing the human steering performance in teleoperated unmanned ground vehicles (UGVs). Human steering performance in teleoperation is considerably different from the performance in regular onboard driving situations due to significant communication delays in teleoperation systems and limited information human teleoperators receive from the vehicle sensory system. Mathematical models capturing the teleoperation performance are a key to making the development and evaluation of teleoperated UGV technologies fully simulation based and thus more rapid and cost-effective. However, driver models developed for the typical onboard driving case do not readily address this need. To fill the gap, this paper adopts a cognitive model that was originally developed for a typical highway driving scenario and develops a tuning strategy that adjusts the model parameters in the absence of human data to reflect the effect of various latencies and UGV speeds on driver performance in a teleoperated path-following task. Based on data collected from a human subject test study, it is shown that the tuned model can predict both the trend of changes in driver performance for different driving conditions and the best steering performance of human subjects in all driving conditions considered. The proposed model with the tuning strategy has a satisfactory performance in predicting human steering behavior in the task of teleoperated path following of UGVs. The established model is a suited candidate to be used in place of human drivers for simulation-based studies of UGV mobility in teleoperation systems.

78 FR 41852 - Hours of Service for Commercial Motor Vehicle Drivers; Regulatory Guidance Concerning Off-Duty Time

Science.gov (United States)

2013-07-12

... provided: 1. The driver is relieved of all duty and responsibility for the care and custody of the vehicle... Service for Commercial Motor Vehicle Drivers; Regulatory Guidance Concerning Off-Duty Time AGENCY: Federal... motor vehicle (CMV) driver to record meal and other routine stops made during a work shift as off-duty...

Fan-shaped antennas: Realization of wideband characteristics and generation of stop bands

Science.gov (United States)

Nakano, H.; Morishita, K.; Iitsuka, Y.; Mimaki, H.; Yoshida, T.; Yamauchi, J.

2008-08-01

This paper presents four fan-shaped antennas: U.S.-FAN, CROSS-FAN, CROSS-FAN-W, and CROSS-FAN-S. Each of these antennas stands upright above a ground plane, and has edges expressed by an exponential function and a circle function. The four antennas are investigated using frequencies from 1.5 GHz to 11 GHz. The CROSS-FAN is found to have a lower VSWR over a wide frequency band compared to the U.S.-FAN. The CROSS-FAN-W and CROSS-FAN-S are modified versions of the CROSS-FAN, each designed to have a stop band (a high VSWR frequency range) for interference cancellation. The stop band for the CROSS-FAN-W is controlled by a wire (total length 4Lwire) that connects the fan-shaped elements. The center frequency of the stop band fstop is close to the frequency corresponding to a wire segment length Lwire of half the wavelength. It is also found that the stop band in the CROSS-FAN-S can be controlled by four slots, one cut into each of the fan-shaped elements. The center frequency of the stop band fstop is close to the frequency corresponding to a slot length Lslot of one-quarter of the wavelength. Experimental work is performed to confirm the theoretical results, using the CROSS-FAN-S.

Inseparability of Go and Stop in Inhibitory Control: Go Stimulus Discriminability Affects Stopping Behavior.

Science.gov (United States)

Ma, Ning; Yu, Angela J

2016-01-01

Inhibitory control, the ability to stop or modify preplanned actions under changing task conditions, is an important component of cognitive functions. Two lines of models of inhibitory control have previously been proposed for human response in the classical stop-signal task, in which subjects must inhibit a default go response upon presentation of an infrequent stop signal: (1) the race model, which posits two independent go and stop processes that race to determine the behavioral outcome, go or stop; and (2) an optimal decision-making model, which posits that observers decides whether and when to go based on continually (Bayesian) updated information about both the go and stop stimuli. In this work, we probe the relationship between go and stop processing by explicitly manipulating the discrimination difficulty of the go stimulus. While the race model assumes the go and stop processes are independent, and therefore go stimulus discriminability should not affect the stop stimulus processing, we simulate the optimal model to show that it predicts harder go discrimination should result in longer go reaction time (RT), lower stop error rate, as well as faster stop-signal RT. We then present novel behavioral data that validate these model predictions. The results thus favor a fundamentally inseparable account of go and stop processing, in a manner consistent with the optimal model, and contradicting the independence assumption of the race model. More broadly, our findings contribute to the growing evidence that the computations underlying inhibitory control are systematically modulated by cognitive influences in a Bayes-optimal manner, thus opening new avenues for interpreting neural responses underlying inhibitory control.

Inseparability of Go and Stop in Inhibitory Control: Go Stimulus Discriminability Affects Stopping Behavior

Directory of Open Access Journals (Sweden)

Ning eMa

2016-03-01

Full Text Available Inhibitory control, the ability to stop or modify preplanned actions under changing task conditions, is an important component of cognitive functions. Two lines of models of inhibitory control have previously been proposed for human response in the classical stop-signal task, in which subjects must inhibit a default go response upon presentation of an infrequent stop signal: (1 the race model, which posits two independent go and stop processes that race to determine the behavioral outcome, go or stop; and (2 an optimal decision-making model, which posits that observers decides whether and when to go based on continually (Bayesian updated information about both the go and stop stimuli. In this work, we probe the relationship between go and stop processing by explicitly manipulating the discrimination difficulty of the go stimulus. While the race model assumes the go and stop processes are independent, and therefore go stimulus discriminability should not affect the stop stimulus processing, we simulate the optimal model to show that it predicts harder go discrimination results in a longer go reaction time (RT, a lower stop error rate, as well as a faster stop-signal RT. We then present novel behavioral data that validate these model predictions. The results thus favor a fundamentally inseparable account of go and stop processing, in a manner consistent with the optimal model, and contradicting the independence assumption of the race model. More broadly, our findings contribute to the growing evidence that the computations underlying inhibitory control are systematically modulated by cognitive influences in a Bayes-optimal manner, thus opening new avenues for interpreting neural responses underlying inhibitory control.

The IXV Ground Segment design, implementation and operations

Science.gov (United States)

Martucci di Scarfizzi, Giovanni; Bellomo, Alessandro; Musso, Ivano; Bussi, Diego; Rabaioli, Massimo; Santoro, Gianfranco; Billig, Gerhard; Gallego Sanz, José María

2016-07-01

The Intermediate eXperimental Vehicle (IXV) is an ESA re-entry demonstrator that performed, on the 11th February of 2015, a successful re-entry demonstration mission. The project objectives were the design, development, manufacturing and on ground and in flight verification of an autonomous European lifting and aerodynamically controlled re-entry system. For the IXV mission a dedicated Ground Segment was provided. The main subsystems of the IXV Ground Segment were: IXV Mission Control Center (MCC), from where monitoring of the vehicle was performed, as well as support during pre-launch and recovery phases; IXV Ground Stations, used to cover IXV mission by receiving spacecraft telemetry and forwarding it toward the MCC; the IXV Communication Network, deployed to support the operations of the IXV mission by interconnecting all remote sites with MCC, supporting data, voice and video exchange. This paper describes the concept, architecture, development, implementation and operations of the ESA Intermediate Experimental Vehicle (IXV) Ground Segment and outlines the main operations and lessons learned during the preparation and successful execution of the IXV Mission.

Semi-autonomous unmanned ground vehicle control system

Science.gov (United States)

Anderson, Jonathan; Lee, Dah-Jye; Schoenberger, Robert; Wei, Zhaoyi; Archibald, James

2006-05-01

Unmanned Ground Vehicles (UGVs) have advantages over people in a number of different applications, ranging from sentry duty, scouting hazardous areas, convoying goods and supplies over long distances, and exploring caves and tunnels. Despite recent advances in electronics, vision, artificial intelligence, and control technologies, fully autonomous UGVs are still far from being a reality. Currently, most UGVs are fielded using tele-operation with a human in the control loop. Using tele-operations, a user controls the UGV from the relative safety and comfort of a control station and sends commands to the UGV remotely. It is difficult for the user to issue higher level commands such as patrol this corridor or move to this position while avoiding obstacles. As computer vision algorithms are implemented in hardware, the UGV can easily become partially autonomous. As Field Programmable Gate Arrays (FPGAs) become larger and more powerful, vision algorithms can run at frame rate. With the rapid development of CMOS imagers for consumer electronics, frame rate can reach as high as 200 frames per second with a small size of the region of interest. This increase in the speed of vision algorithm processing allows the UGVs to become more autonomous, as they are able to recognize and avoid obstacles in their path, track targets, or move to a recognized area. The user is able to focus on giving broad supervisory commands and goals to the UGVs, allowing the user to control multiple UGVs at once while still maintaining the convenience of working from a central base station. In this paper, we will describe a novel control system for the control of semi-autonomous UGVs. This control system combines a user interface similar to a simple tele-operation station along with a control package, including the FPGA and multiple cameras. The control package interfaces with the UGV and provides the necessary control to guide the UGV.

A nonlinear model predictive control formulation for obstacle avoidance in high-speed autonomous ground vehicles in unstructured environments

Science.gov (United States)

Liu, Jiechao; Jayakumar, Paramsothy; Stein, Jeffrey L.; Ersal, Tulga

2018-06-01

This paper presents a nonlinear model predictive control (MPC) formulation for obstacle avoidance in high-speed, large-size autono-mous ground vehicles (AGVs) with high centre of gravity (CoG) that operate in unstructured environments, such as military vehicles. The term 'unstructured' in this context denotes that there are no lanes or traffic rules to follow. Existing MPC formulations for passenger vehicles in structured environments do not readily apply to this context. Thus, a new nonlinear MPC formulation is developed to navigate an AGV from its initial position to a target position at high-speed safely. First, a new cost function formulation is used that aims to find the shortest path to the target position, since no reference trajectory exists in unstructured environments. Second, a region partitioning approach is used in conjunction with a multi-phase optimal control formulation to accommodate the complicated forms the obstacle-free region can assume due to the presence of multiple obstacles in the prediction horizon in an unstructured environment. Third, the no-wheel-lift-off condition, which is the major dynamical safety concern for high-speed, high-CoG AGVs, is ensured by limiting the steering angle within a range obtained offline using a 14 degrees-of-freedom vehicle dynamics model. Thus, a safe, high-speed navigation is enabled in an unstructured environment. Simulations of an AGV approaching multiple obstacles are provided to demonstrate the effectiveness of the algorithm.

Control of autonomous ground vehicles: a brief technical review

Science.gov (United States)

Babak, Shahian-Jahromi; Hussain, Syed A.; Karakas, Burak; Cetin, Sabri

2017-07-01

This paper presents a brief review of the developments achieved in autonomous vehicle systems technology. A concise history of autonomous driver assistance systems is presented, followed by a review of current state of the art sensor technology used in autonomous vehicles. Standard sensor fusion method that has been recently explored is discussed. Finally, advances in embedded software methodologies that define the logic between sensory information and actuation decisions are reviewed.

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…

Lightning and surge protection of large ground facilities

Science.gov (United States)

Stringfellow, Michael F.

1988-04-01

The vulnerability of large ground facilities to direct lightning strikes and to lightning-induced overvoltages on the power distribution, telephone and data communication lines are discussed. Advanced electrogeometric modeling is used for the calculation of direct strikes to overhead power lines, buildings, vehicles and objects within the facility. Possible modes of damage, injury and loss are discussed. Some appropriate protection methods for overhead power lines, structures, vehicles and aircraft are suggested. Methods to mitigate the effects of transients on overhead and underground power systems as well as within buildings and other structures are recommended. The specification and location of low-voltage surge suppressors for the protection of vulnerable hardware such as computers, telecommunication equipment and radar installations are considered. The advantages and disadvantages of commonly used grounding techniques, such as single point, multiple and isolated grounds are compared. An example is given of the expected distribution of lightning flashes to a large airport, its buildings, structures and facilities, as well as to vehicles on the ground.

Stopping, goal-conflict, trait anxiety and frontal rhythmic power in the stop-signal task.

Science.gov (United States)

Neo, Phoebe S-H; Thurlow, Jane K; McNaughton, Neil

2011-12-01

The medial right frontal cortex is implicated in fast stopping of an initiated motor action in the stop-signal task (SST). To assess whether this region is also involved in the slower behavioural inhibition induced by goal conflict, we tested for effects of goal conflict (when stop and go tendencies are balanced) on low-frequency rhythms in the SST. Stop trials were divided, according to the delays at which the stop signal occurred, into short-, intermediate-, and long-delay trials. Consistent with goal-conflict processing, intermediate-delay trials were associated with greater 7-8 Hz EEG power than short- or long-delay trials at medial right frontal sites (Fz, F4, and F8). At F8, 7-8 Hz power was linked to high trait anxiety and neuroticism. A separate 4-7 Hz power increase was also seen in stop, relative to go, trials, but this was independent of delay, was maximal at the central midline site Cz, and predicted faster stopping. Together with previous data on the SST, these results suggest that the right frontal region could be involved in multiple inhibition mechanisms. We propose a hierarchical model of the control of stopping that integrates the literature on the neural control of fast motor stopping with that on slower, motive-directed behavioural inhibition.

Hot Ground Vibration Tests

Data.gov (United States)

National Aeronautics and Space Administration — Ground vibration tests or modal surveys are routinely conducted to support flutter analysis for subsonic and supersonic vehicles. However, vibration testing...

Association of Prehospital Mode of Transport With Mortality in Penetrating Trauma: A Trauma System-Level Assessment of Private Vehicle Transportation vs Ground Emergency Medical Services.

Science.gov (United States)

Wandling, Michael W; Nathens, Avery B; Shapiro, Michael B; Haut, Elliott R

2018-02-01

Time to definitive care following injury is important to the outcomes of trauma patients. Prehospital trauma care is provided based on policies developed by individual trauma systems and is an important component of the care of injured patients. Given a paucity of systems-level trauma research, considerable variability exists in prehospital care policies across trauma systems, potentially affecting patient outcomes. To evaluate whether private vehicle prehospital transport confers a survival advantage vs ground emergency medical services (EMS) transport following penetrating injuries in urban trauma systems. Retrospective cohort study of data included in the National Trauma Data Bank from January 1, 2010, through December 31, 2012, comprising 298 level 1 and level 2 trauma centers that contribute data to the National Trauma Data Bank that are located within the 100 most populous metropolitan areas in the United States. Of 2 329 446 patients assessed for eligibility, 103 029 were included in this study. All patients were 16 years or older, had a gunshot wound or stab wound, and were transported by ground EMS or private vehicle. In-hospital mortality. Of the 2 329 446 records assessed for eligibility, 103 029 individuals at 298 urban level 1 and level 2 trauma centers were included in the analysis. The study population was predominantly male (87.6%), with a mean age of 32.3 years. Among those included, 47.9% were black, 26.3% were white, and 18.4% were Hispanic. Following risk adjustment, individuals with penetrating injuries transported by private vehicle were less likely to die than patients transported by ground EMS (odds ratio [OR], 0.38; 95% CI, 0.31-0.47). This association remained statistically significant on stratified analysis of the gunshot wound (OR,  0.45; 95% CI, 0.36-0.56) and stab wound (OR,  0.32; 95% CI, 0.20-0.52) subgroups. Private vehicle transport is associated with a significantly lower likelihood of death when compared with

Aerodynamic Problems of Launch Vehicles

Directory of Open Access Journals (Sweden)

Kyong Chol Chou

1984-09-01

Full Text Available The airflow along the surface of a launch vehicle together with vase flow of clustered nozzles cause problems which may affect the stability or efficiency of the entire vehicle. The problem may occur when the vehicle is on the launching pad or even during flight. As for such problems, local steady-state loads, overall steady-state loads, buffet, ground wind loads, base heating and rocket-nozzle hinge moments are examined here specifically.

3-D model-based vehicle tracking.

Science.gov (United States)

Lou, Jianguang; Tan, Tieniu; Hu, Weiming; Yang, Hao; Maybank, Steven J

2005-10-01

This paper aims at tracking vehicles from monocular intensity image sequences and presents an efficient and robust approach to three-dimensional (3-D) model-based vehicle tracking. Under the weak perspective assumption and the ground-plane constraint, the movements of model projection in the two-dimensional image plane can be decomposed into two motions: translation and rotation. They are the results of the corresponding movements of 3-D translation on the ground plane (GP) and rotation around the normal of the GP, which can be determined separately. A new metric based on point-to-line segment distance is proposed to evaluate the similarity between an image region and an instantiation of a 3-D vehicle model under a given pose. Based on this, we provide an efficient pose refinement method to refine the vehicle's pose parameters. An improved EKF is also proposed to track and to predict vehicle motion with a precise kinematics model. Experimental results with both indoor and outdoor data show that the algorithm obtains desirable performance even under severe occlusion and clutter.

Intelligent Unmanned Vehicle Systems Suitable For Individual or Cooperative Missions

Energy Technology Data Exchange (ETDEWEB)

Matthew O. Anderson; Mark D. McKay; Derek C. Wadsworth

2007-04-01

The Department of Energy’s Idaho National Laboratory (INL) has been researching autonomous unmanned vehicle systems for the past several years. Areas of research have included unmanned ground and aerial vehicles used for hazardous and remote operations as well as teamed together for advanced payloads and mission execution. Areas of application include aerial particulate sampling, cooperative remote radiological sampling, and persistent surveillance including real-time mosaic and geo-referenced imagery in addition to high resolution still imagery. Both fixed-wing and rotary airframes are used possessing capabilities spanning remote control to fully autonomous operation. Patented INL-developed auto steering technology is taken advantage of to provide autonomous parallel path swathing with either manned or unmanned ground vehicles. Aerial look-ahead imagery is utilized to provide a common operating picture for the ground and air vehicle during cooperative missions. This paper will discuss the various robotic vehicles, including sensor integration, used to achieve these missions and anticipated cost and labor savings.

A Fully-Distributed Heuristic Algorithm for Control of Autonomous Vehicle Movements at Isolated Intersections

OpenAIRE

Abdallah A. Hassan; Hesham A. Rakha

2014-01-01

Optimizing autonomous vehicle movements through roadway intersections is a challenging problem. It has been demonstrated in the literature that traditional traffic control, such as traffic signal and stop sign control are not optimal especially for heavy traffic demand levels. Alternatively, centralized autonomous vehicle control strategies are costly and not scalable given that the ability of a central controller to track and schedule the movement of hundreds of vehicles in real-time is ques...

Energy density, stopping and flow in ultrarelativistic heavy ion collisions

International Nuclear Information System (INIS)

Sorge, H.; von Keitz, A.; Mattiello, R.; Stoecker, H.; Greiner, W.

1990-01-01

The Lorentz invariant molecular dynamics approach (RQMD) is employed to investigate the space-time evolution of heavy ion collisions at energies (E kin = 10AGeV hor-ellipsis 200AGeV). The calculations for various nucleus nucleus reactions show a high degree of stopping power. The importance of secondary rescattering at these beam energies is demonstrated. The computed nucleon rapidity distributions are compared to available experimental data. It is demonstrated that nonlinear, collective effects like full stopping of target and projectile and matter flow could be expected for heavy projectiles only. For nuclear collisions in the Booster era at BNL and for the lead beam at CERN SPS the authors predict a stimulating future: then a nearly equilibrated, long lived (8 fm/c) macroscopic volume of very high energy density (> 1 GeV/fm 3 ) and baryon density (> 5 times ground state density) is produced

High-Energy Laser Weapon Integration with Ground Vehicles

National Research Council Canada - National Science Library

Hafften, Michael; Stratton, Robert

2004-01-01

.... The architecture of an electric, solid-state HEL weapon system would likely be based upon a hybrid electric vehicle that provides a common electrical power source for the propulsion and weapon subsystems...

Crewed Space Vehicle Battery Safety Requirements

Science.gov (United States)

Jeevarajan, Judith A.; Darcy, Eric C.

2014-01-01

This requirements document is applicable to all batteries on crewed spacecraft, including vehicle, payload, and crew equipment batteries. It defines the specific provisions required to design a battery that is safe for ground personnel and crew members to handle and/or operate during all applicable phases of crewed missions, safe for use in the enclosed environment of a crewed space vehicle, and safe for use in launch vehicles, as well as in unpressurized spaces adjacent to the habitable portion of a space vehicle. The required provisions encompass hazard controls, design evaluation, and verification. The extent of the hazard controls and verification required depends on the applicability and credibility of the hazard to the specific battery design and applicable missions under review. Evaluation of the design and verification program results shall be completed prior to certification for flight and ground operations. This requirements document is geared toward the designers of battery systems to be used in crewed vehicles, crew equipment, crew suits, or batteries to be used in crewed vehicle systems and payloads (or experiments). This requirements document also applies to ground handling and testing of flight batteries. Specific design and verification requirements for a battery are dependent upon the battery chemistry, capacity, complexity, charging, environment, and application. The variety of battery chemistries available, combined with the variety of battery-powered applications, results in each battery application having specific, unique requirements pertinent to the specific battery application. However, there are basic requirements for all battery designs and applications, which are listed in section 4. Section 5 includes a description of hazards and controls and also includes requirements.

Influence of Traffic Vehicles Against Ground Fundamental Frequency Prediction using Ambient Vibration Technique

Science.gov (United States)

Kamarudin, A. F.; Noh, M. S. Md; Mokhatar, S. N.; Anuar, M. A. Mohd; Ibrahim, A.; Ibrahim, Z.; Daud, M. E.

2018-04-01

Ambient vibration (AV) technique is widely used nowadays for ground fundamental frequency prediction. This technique is easy, quick, non-destructive, less operator required and reliable result. The input motions of ambient vibration are originally collected from surrounding natural and artificial excitations. But, careful data acquisition controlled must be implemented to reduce the intrusion of short period noise that could imply the quality of frequency prediction of an investigated site. In this study, investigation on the primary noise intrusion under peak (morning, afternoon and evening) and off peak (early morning) traffic flows (only 8 meter from sensor to road shoulder) against the stability and quality of ground fundamental frequency prediction were carried out. None of specific standard is available for AV data acquisition and processing. Thus, some field and processing parameters recommended by previous studies and guideline were considered. Two units of 1 Hz tri-axial seismometer sensor were closely positioned in front of the main entrance Universiti Tun Hussein Onn Malaysia. 15 minutes of recording length were taken during peak and off peak periods of traffic flows. All passing vehicles were counted and grouped into four classes. Three components of ambient vibration time series recorded in the North-South: NS, East-West: EW and vertical: UD directions were automatically computed into Horizontal to Vertical Spectral Ratio (HVSR), by using open source software of GEOPSY for fundamental ground frequency, Fo determination. Single sharp peak pattern of HVSR curves have been obtained at peak frequencies between 1.33 to 1.38 Hz which classified under soft to dense soil classification. Even identical HVSR curves pattern with close frequencies prediction were obtained under both periods of AV measurement, however the total numbers of stable and quality windows selected for HVSR computation were significantly different but both have satisfied the requirement

Vehicle Theft Identification and Intimation Using GSM & IOT

Science.gov (United States)

Eswar Kumar, M.; Thippa Reddy, G.; Sudheer, K.; Reddy, M. Praveen Kumar; Kaluri, Rajesh; Singh Rajput, Dharmendra; Lakshmanna, Kuruva

2017-11-01

Internet of Things is the most predominant innovation associates the things through web. IoT is a technology which interfaces things from different places on the planet. Home mechanization is a wide range innovation in IoT technology on the planet. Home automation constitutes in security issues, controlling gadgets and so on. In existing model, the vehicle theft is distinguished and controlled by physically with GSM module. Furthermore, there are a few in controlling the vehicle is major issue for owner from theft. Here in this paper a technique described to overcome issue of existing one. In this the vehicle is identified, controlled and connected updates with Internet in a simple way. By utilization of AT commands of GSM module a message will be send to the owner that the vehicle is recognized. Action can be taken by sending a reply to GSM module to stop motor of vehicle. Arduino uno board is used to interface the GSM and engine of vehicle with appropriate sensors. Visual studio, Arduino uno are the programming software used to outline this application.

Zero emission vehicle for dense grid urban public transportation

Energy Technology Data Exchange (ETDEWEB)

D' Ovidio, G. [University of l' Aquila, Faculty of Engineering, DAU (Italy)

2000-07-01

This paper reports the operating scheme of a public transportation vehicle with zero polluting emission, working in urban areas in a transport network which has short and regular stop spacing not greater than 400-500 m, and by segments covered by 'shuttle-type' vehicles with high operating frequencies. In particular, the traction of the vehicle, of electric type exclusively, is supported by the functional coupling of an accumulation and alimentation system composed respectively of Fuel Cell e Flywheel Energy Storage Unite. This study proposes and analyzes a typology of hybrid vehicle of which the configuration of traction is specialized for the exigency connected to the different phases of the motion. The study contains the analysis and the measurement of the principal components of the propulsion system to the vary of the loading capabilities of the vehicles and of the geometric characteristic of the transport network.

Asynchronous vehicle pose correction using visual detection of ground features

International Nuclear Information System (INIS)

Harnarinesingh, Randy E S; Syan, Chanan S

2014-01-01

The inherent noise associated with odometry manifests itself as errors in localization for autonomous vehicles. Visual odometry has been previously used in order to supplement classical vehicle odometry. However, visual odometry is limited in its ability to reduce errors in localization for large travel distances that entail the cumulative summing of individual frame-to-frame image errors. In this paper, a novel machine vision approach for tiled surfaces is proposed to address this problem. Tile edges in a laboratory environment are used to define a travel trajectory for the Quansar Qbot (autonomous vehicle) built on the iRobot iRoomba platform with a forward facing camera. Tile intersections are used to enable asynchronous error recovery for vehicle position and orientation. The proposed approach employs real-time image classification and is feasible for error mitigation for large travel distances. The average position error for an 8m travel distance using classical odometry was measured to be 0.28m. However, implementation of the proposed approach resulted in an error of 0.028m. The proposed approach therefore significantly reduces pose estimation error and could be used to supplement existing modalities such as GPS and Laser-based range sensors

Evolutionary algorithm for vehicle driving cycle generation.

Science.gov (United States)

Perhinschi, Mario G; Marlowe, Christopher; Tamayo, Sergio; Tu, Jun; Wayne, W Scott

2011-09-01

Modeling transit bus emissions and fuel economy requires a large amount of experimental data over wide ranges of operational conditions. Chassis dynamometer tests are typically performed using representative driving cycles defined based on vehicle instantaneous speed as sequences of "microtrips", which are intervals between consecutive vehicle stops. Overall significant parameters of the driving cycle, such as average speed, stops per mile, kinetic intensity, and others, are used as independent variables in the modeling process. Performing tests at all the necessary combinations of parameters is expensive and time consuming. In this paper, a methodology is proposed for building driving cycles at prescribed independent variable values using experimental data through the concatenation of "microtrips" isolated from a limited number of standard chassis dynamometer test cycles. The selection of the adequate "microtrips" is achieved through a customized evolutionary algorithm. The genetic representation uses microtrip definitions as genes. Specific mutation, crossover, and karyotype alteration operators have been defined. The Roulette-Wheel selection technique with elitist strategy drives the optimization process, which consists of minimizing the errors to desired overall cycle parameters. This utility is part of the Integrated Bus Information System developed at West Virginia University.

Progress in understanding heavy-ion stopping

Energy Technology Data Exchange (ETDEWEB)

Sigmund, P., E-mail: sigmund@sdu.dk [Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, DK-5230 Odense M (Denmark); Schinner, A. [Institut für Experimentalphysik, Johannes Kepler Universität, A-4040 Linz (Austria)

2016-09-01

We report some highlights of our work with heavy-ion stopping in the energy range where Bethe stopping theory breaks down. Main tools are our binary stopping theory (PASS code), the reciprocity principle, and Paul’s data base. Comparisons are made between PASS and three alternative theoretical schemes (CasP, HISTOP and SLPA). In addition to equilibrium stopping we discuss frozen-charge stopping, deviations from linear velocity dependence below the Bragg peak, application of the reciprocity principle in low-velocity stopping, modeling of equilibrium charges, and the significance of the so-called effective charge.

Progress in understanding heavy-ion stopping

International Nuclear Information System (INIS)

Sigmund, P.; Schinner, A.

2016-01-01

We report some highlights of our work with heavy-ion stopping in the energy range where Bethe stopping theory breaks down. Main tools are our binary stopping theory (PASS code), the reciprocity principle, and Paul’s data base. Comparisons are made between PASS and three alternative theoretical schemes (CasP, HISTOP and SLPA). In addition to equilibrium stopping we discuss frozen-charge stopping, deviations from linear velocity dependence below the Bragg peak, application of the reciprocity principle in low-velocity stopping, modeling of equilibrium charges, and the significance of the so-called effective charge.

Agutaynen Glottal Stop.

Science.gov (United States)

Quakenbush, J. Stephen

A study investigated the phonemic and morphophonemic patterning of the glottal stop in Agutaynen, a Meso-Philippine language, and some comparison with two northern Philippine languages. Agutaynen glottal stop has as its sole origin a neutralization of contrast rule, the operation of which can be noted in three different linguistic environments.…

Thermal management of hybrid vehicles. Challenges and solutions; Thermomanagement von Hybridfahrzeugen. Herausforderungen und Loesungen

Energy Technology Data Exchange (ETDEWEB)

Heckenberger, T. [Behr GmbH und Co. KG, Stuttgart (Germany)

2007-10-15

Higher thermal management demands are placed on hybrid vehicles than on conventional vehicles. The thermal comfort of the passengers must be assured when the combustion engine shuts down, i.e. during start-stop phases and during purely electric driving. Likewise, the particular hybrid modules and components must be cooled to temperature levels that are too low for conventional cooling circuits. Behr is presently developing cooling and climate control systems for all three types of hybrid vehicles: micro-, mild, and full hybrids. (orig.)

Labview Application For A Vehicle Control

Directory of Open Access Journals (Sweden)

Douglas Paladine Vieira

2002-01-01

Full Text Available This article deals with the construction of a vehicle driven by electric motors and that is automated, that is, that can move anywhere without human intervention. The control was done using the software Labview, with data acquisition and generation of control signs. The vehicle has an infrared sensors system that indicates the existence of an obstacle ahead the vehicle, informing it that it should stop and bypass the obstacle. The program is the responsible for the engine control, making it possible for the prototype to run and bypass the objects that block its way. The possibility of remote-controlling a vehicle is very important is risky situations for human beings, for example in radioactive places. The main advantage of this system is the total flexibility for making alterations in the control software, without being necessary to touch the physical part of the prototype. The conclusion of this work is that the system is efficient and able to move in a room with objects without touching them.

Obstacle detection system for underground mining vehicles

Energy Technology Data Exchange (ETDEWEB)

Cohen, P.; Polotski, V.; Piotte, M.; Melamed, F. [Ecole Polytechnique de Montreal, Montreal, PQ (Canada)

1998-01-01

A device for detecting obstacles by autonomous vehicles navigating in mine drifts is described. The device is based upon structured lighting and the extraction of relevant features from images of obstacles. The system uses image profile changes, ground and wall irregularities, disturbances of the vehicle`s trajectory, and impaired visibility to detect obstacles, rather than explicit three-dimensional scene reconstruction. 7 refs., 5 figs.

All in One Stop? The Accessibility of Work Support Programs at One-Stop Centers.

Science.gov (United States)

Richer, Elise; Kubo, Hitomi; Frank, Abbey

The accessibility of work support programs at one-stop centers was examined in a study during which 33 telephone directors or managers of one-stop centers in 22 states were interviewed by telephone. The interviews established the existence of extensive differences between one-stop centers from the standpoint of all aspects of their operation,…

LHC Availability 2017: Technical Stop 1 to Technical Stop 2

CERN Document Server

Todd, Benjamin; Apollonio, Andrea; Walsh, David John; CERN. Geneva. ATS Department

2017-01-01

This document summarises the LHC machine availability for the period of Technical Stop 1 (TS1) to Technical Stop 2 (TS2) in 2017. This period was dedicated to proton physics with a bunch spacing of 25ns. This note has been produced and ratified by the Availability Working Group which has complied fault information for the period in question using the Accelerator Fault Tracker.

14 CFR 415.117 - Ground safety.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Ground safety. 415.117 Section 415.117... TRANSPORTATION LICENSING LAUNCH LICENSE Safety Review and Approval for Launch of an Expendable Launch Vehicle From a Non-Federal Launch Site § 415.117 Ground safety. (a) General. An applicant's safety review...

Luminescent beam stop

Energy Technology Data Exchange (ETDEWEB)

Bryant, Diane; Morton, Simon A.

2017-10-25

This disclosure provides systems, methods, and apparatus related to beam stops. In one aspect, a device comprises a luminescent material, a beam stop plate, and an optical fiber. The luminescent material is a parallelepiped having a first side and a second side that are squares and having a third side that is a rectangle or a square. The first side and the second side are perpendicular to the third side. The beam stop plate is attached to the first side of the luminescent material. The optical fiber has a first end and a second end, with the first end of the optical fiber attached to the third side of the luminescent material.

Remotely detected vehicle mass from engine torque-induced frame twisting

Science.gov (United States)

McKay, Troy R.; Salvaggio, Carl; Faulring, Jason W.; Sweeney, Glenn D.

2017-06-01

Determining the mass of a vehicle from ground-based passive sensor data is important for many traffic safety requirements. This work presents a method for calculating the mass of a vehicle using ground-based video and acoustic measurements. By assuming that no energy is lost in the conversion, the mass of a vehicle can be calculated from the rotational energy generated by the vehicle's engine and the linear acceleration of the vehicle over a period of time. The amount of rotational energy being output by the vehicle's engine can be calculated from its torque and angular velocity. This model relates remotely observed, engine torque-induced frame twist to engine torque output using the vehicle's suspension parameters and engine geometry. The angular velocity of the engine is extracted from the acoustic emission of the engine, and the linear acceleration of the vehicle is calculated by remotely observing the position of the vehicle over time. This method combines these three dynamic signals; engine induced-frame twist, engine angular velocity, and the vehicle's linear acceleration, and three vehicle specific scalar parameters, into an expression that describes the mass of the vehicle. This method was tested on a semitrailer truck, and the results demonstrate a correlation of 97.7% between calculated and true vehicle mass.

Probing Light Stops with Stoponium

CERN Document Server

Batell, Brian

2015-01-01

We derive new limits on light stops from diboson resonance searches in the $\\gamma\\gamma$, $Z \\gamma$, $ZZ$, $WW$ and $hh$ channels from the first run of the LHC. If the two-body decays of the light stop are mildly suppressed or kinematically forbidden, stoponium bound states will form in $pp$ collisions and subsequently decay via the pair annihilation of the constituent stops to diboson final states, yielding striking resonance signatures. Remarkably, we find that stoponium searches are highly complementary to direct collider searches and indirect probes of light stops such as Higgs coupling measurements. Using an empirical quarkonia potential model and including the first two $S$-wave stoponium states, we find that in the decoupling limit $m_{\\widetilde t_1} \\lesssim 130$ GeV is excluded for any value of the stop mixing angle and heavy stop mass by the combination of the latest resonance searches and the indirect constraints. The $\\gamma \\gamma$ searches are the most complementary to the indirect constraint...

Road-Following Formation Control of Autonomous Ground Vehicles

Science.gov (United States)

Ono, Masahiro; Droge, Greg; Grip, Havard; Toupet, Olivier; Scrapper, Chris; Rahmani, Amir

2015-01-01

This work presents a novel cooperative path planning for formation keeping robots traversing along a road with obstacles and possible narrow passages. A unique challenge in this problem is a requirement for spatial and temporal coordination between vehicles while ensuring collision and obstacle avoidance.

Space vehicle field unit and ground station system

Science.gov (United States)

Judd, Stephen; Dallmann, Nicholas; Delapp, Jerry; Proicou, Michael; Seitz, Daniel; Michel, John; Enemark, Donald

2017-09-19

A field unit and ground station may use commercial off-the-shelf (COTS) components and share a common architecture, where differences in functionality are governed by software. The field units and ground stations may be easy to deploy, relatively inexpensive, and be relatively easy to operate. A novel file system may be used where datagrams of a file may be stored across multiple drives and/or devices. The datagrams may be received out of order and reassembled at the receiving device.

Stop smoking support programs

Science.gov (United States)

Smokeless tobacco - stop smoking programs; Stop smoking techniques; Smoking cessation programs; Smoking cessation techniques ... You can find out about smoking cessation programs from: Your ... Your employer Your local health department The National Cancer ...

AWARE: Platform for Autonomous self-deploying and operation of Wireless sensor-actuator networks cooperating with unmanned AeRial vehiclEs

NARCIS (Netherlands)

Ollero, Anibal; Bernard, Markus; La Civita, Marco; van Hoesel, L.F.W.; Marron, Pedro J.; Lepley, Jason; de Andres, Eduardo

This paper presents the AWARE platform that seeks to enable the cooperation of autonomous aerial vehicles with ground wireless sensor-actuator networks comprising both static and mobile nodes carried by vehicles or people. Particularly, the paper presents the middleware, the wireless sensor network,

Electric and Hybrid Vehicle Technology: TOPTEC

Energy Technology Data Exchange (ETDEWEB)

1992-01-01

Today, growing awareness of environmental and energy issues associated with the automobile has resulted in renewed interest in the electric vehicle. In recognition of this, the Society of Automotive Engineers has added a TOPTEC on electric vehicles to the series of technical symposia focused on key issues currently facing industry and government. This workshop on the Electric and Hybrid Vehicle provides an opportunity to learn about recent progress in these rapidly changing technologies. Research and development of both the vehicle and battery system has accelerated sharply and in fact, the improved technologies of the powertrain system make the performance of today's electric vehicle quite comparable to the equivalent gasoline vehicle, with the exception of driving range between refueling'' stops. Also, since there is no tailpipe emission, the electric vehicle meets the definition of Zero Emission Vehicle: embodied in recent air quality regulations. The discussion forum will include a review of the advantages and limitations of electric vehicles, where the technologies are today and where they need to be in order to get to production level vehicles, and the service and maintenance requirements once they get to the road. There will be a major focus on the status of battery technologies, the various approaches to recharge of the battery systems and the activities currently underway for developing standards throughout the vehicle and infrastructure system. Intermingled in all of this technology discussion will be a view of the new relationships emerging between the auto industry, the utilities, and government. Since the electric vehicle and its support system will be the most radical change ever introduced into the private vehicle sector of the transportation system, success in the market requires an understanding of the role of all of the partners, as well as the new technologies involved.

Electric and Hybrid Vehicle Technology: TOPTEC

Energy Technology Data Exchange (ETDEWEB)

1992-12-01

Today, growing awareness of environmental and energy issues associated with the automobile has resulted in renewed interest in the electric vehicle. In recognition of this, the Society of Automotive Engineers has added a TOPTEC on electric vehicles to the series of technical symposia focused on key issues currently facing industry and government. This workshop on the Electric and Hybrid Vehicle provides an opportunity to learn about recent progress in these rapidly changing technologies. Research and development of both the vehicle and battery system has accelerated sharply and in fact, the improved technologies of the powertrain system make the performance of today`s electric vehicle quite comparable to the equivalent gasoline vehicle, with the exception of driving range between ``refueling`` stops. Also, since there is no tailpipe emission, the electric vehicle meets the definition of ``Zero Emission Vehicle: embodied in recent air quality regulations. The discussion forum will include a review of the advantages and limitations of electric vehicles, where the technologies are today and where they need to be in order to get to production level vehicles, and the service and maintenance requirements once they get to the road. There will be a major focus on the status of battery technologies, the various approaches to recharge of the battery systems and the activities currently underway for developing standards throughout the vehicle and infrastructure system. Intermingled in all of this technology discussion will be a view of the new relationships emerging between the auto industry, the utilities, and government. Since the electric vehicle and its support system will be the most radical change ever introduced into the private vehicle sector of the transportation system, success in the market requires an understanding of the role of all of the partners, as well as the new technologies involved.

Electric and hybrid vehicle technology: TOPTEC

Science.gov (United States)

Today, growing awareness of environmental and energy issues associated with the automobile has resulted in renewed interest in the electric vehicle. In recognition of this, the Society of Automotive Engineers has added a TOPTEC on electric vehicles to the series of technical symposia focused on key issues currently facing industry and government. This workshop on the Electric and Hybrid Vehicle provides an opportunity to learn about recent progress in these rapidly changing technologies. Research and development of both the vehicle and battery system has accelerated sharply and in fact, the improved technologies of the powertrain system make the performance of today's electric vehicle quite comparable to the equivalent gasoline vehicle, with the exception of driving range between 'refueling' stops. Also, since there is no tailpipe emission, the electric vehicle meets the definition of 'Zero Emission Vehicle: embodied in recent air quality regulations. The discussion forum will include a review of the advantages and limitations of electric vehicles, where the technologies are today and where they need to be in order to get to production level vehicles, and the service and maintenance requirements once they get to the road. There will be a major focus on the status of battery technologies, the various approaches to recharge of the battery systems and the activities currently underway for developing standards throughout the vehicle and infrastructure system. Intermingled in all of this technology discussion will be a view of the new relationships emerging between the auto industry, the utilities, and government. Since the electric vehicle and its support system will be the most radical change ever introduced into the private vehicle sector of the transportation system, success in the market requires an understanding of the role of all of the partners, as well as the new technologies involved.

Retroactive Stop Loss Special Pay

Science.gov (United States)

Pay (RSLSP), providing $500 for each month/partial month served in stop loss status. Service members served under stop loss must submit a claim for the special pay. Throughout the year, the services have or extension of service, became ineligible to receive retroactive stop loss special pay. There may be

Stop feeling: inhibition of emotional interference following stop-signal trials.

Science.gov (United States)

Kalanthroff, Eyal; Cohen, Noga; Henik, Avishai

2013-01-01

Although a great deal of literature has been dedicated to the mutual links between emotion and the selective attention component of executive control, there is very little data regarding the links between emotion and the inhibitory component of executive control. In the current study we employed an emotional stop-signal task in order to examine whether emotion modulates and is modulated by inhibitory control. Results replicated previous findings showing reduced inhibitory control [longer stop-signal reaction time (SSRT)] following negative, compared to neutral pictures. Most importantly, results show decreased emotional interference following stop-signal trials. These results show that the inhibitory control component of executive control can serve to decrease emotional effects. We suggest that inhibitory control and emotion have a two-way connection in which emotion disrupts inhibitory control and activation of inhibitory control disrupts emotion.

Stop feeling: Inhibition of emotional interference following stop-signal trials

Directory of Open Access Journals (Sweden)

Eyal eKalanthroff

2013-03-01

Full Text Available Although a great deal of literature has been dedicated to the mutual links between emotion and the selective attention component of executive control, there is very little data regarding the links between emotion and the inhibitory component of executive control. In the current study we employed an emotional stop-signal task in order to examine whether emotion modulates and is modulated by inhibitory control. Results replicated previous findings showing reduced inhibitory control (longer stop-signal reaction time following negative, compared to neutral pictures. Most importantly, results show decreased emotional interference following stop-signal trials. These results show that the inhibitory control component of executive control can serve to decrease emotional effects. We suggest that inhibitory control and emotion have a two-way connection in which emotion disrupts inhibitory control and activation of inhibitory control disrupts emotion.

Stop feeling: Inhibition of emotional interference following stop-signal trials

OpenAIRE

Eyal eKalanthroff; Noga eCohen; Avishai eHenik

2013-01-01

Although a great deal of literature has been dedicated to the mutual links between emotion and the selective attention component of executive control, there is very little data regarding the links between emotion and the inhibitory component of executive control. In the current study we employed an emotional stop-signal task in order to examine whether emotion modulates and is modulated by inhibitory control. Results replicated previous findings showing reduced inhibitory control [longer stop...

49 CFR 178.320 - General requirements applicable to all DOT specification cargo tank motor vehicles.

Science.gov (United States)

2010-10-01

... removed from the motor vehicle; and (3) Is not fabricated under a specification for cylinders... determine leak tightness of the cargo tank when testing with pneumatic pressure. Internal self-closing stop...

Design of an urban driverless ground vehicle

OpenAIRE

Benenson , Rodrigo; Parent , Michel ,

2008-01-01

International audience; This paper presents the design and implementation of a driverless car for populated urban environments. We propose a system that explicitly map the static obstacles, detects and track the moving obstacle, consider the unobserved areas, provide a motion plan with safety guarantees and executes it. All of it was implemented and integrated into a single computer maneuvering on real time an electric vehicle into an unvisited area with moving obstacles. The overview of the ...

Task and Motion Planning for Selective Weed Conrol using a Team of Autonomous Vehicles

DEFF Research Database (Denmark)

Hameed, Ibrahim; la Cour-Harbo, Anders; Hansen, Karl Damkjær

2014-01-01

with the right amount. In this article, a task and motion planning for a team of autonomous vehicles to reduce chemicals in farming is presented. Field data are collected by small unmanned helicopters equipped with a range of sensors, including multispectral and thermal cameras. Data collected are transmitted...... to a ground station to be analyzed and triggers aerial and ground-based vehicles to start close inspection and/or plant/weed treatment in specified areas. A complete trajectory is generated to enable ground-based vehicle to visit infested areas and start chemical/mechanical weed treatment....

Exploring the impact of signal types and adjacent vehicles on drivers' choices after the onset of yellow

Science.gov (United States)

Bao, Ji; Chen, Qun; Luo, Dandan; Wu, Yuli; Liang, Zuli

2018-06-01

Drivers' choices at signalized intersections may be made in great uncertainty after the onset of yellow, which creates potential hazards for road safety. These choices are analyzed and modeled based on field observations at three comparable signalized intersections in Changsha, China. The results show that intersections without monitoring devices widen the indecision zone, which can increase the risk of rear-end collisions and the uncertainty of drivers' decision-making. In addition, drivers are more likely to stop during the yellow interval at intersections equipped with a green signal countdown device (GSCD) than at those with a green signal flashing device (GSFD). Subsequently, according to the results of a binary logistic regression model (BLRM), drivers' decision making at the onset of the yellow indication is greatly influenced by the vehicle's spot speed, the distance to the stop line, and signal and monitoring devices. The presence of an adjacent vehicle with a short space headway can particularly motivate the following driver to make a go-decision after the first driver chooses to pass the intersection. However, a stop-decision by a driver in an adjacent lane can also prompt the following driver to stop.

Reduced Attitude Control of a Robotic Underwater Vehicle

Directory of Open Access Journals (Sweden)

Bláha Lukáš

2017-01-01

Full Text Available This paper deals with stabilization and reduced attitude control of a robotic underwater vehicle. The vehicle is assumed to be able to perform a full stable rotations around all axes in underwater space, that is why the standard bottom-heavy structure is not used. The system preferably uses a vectored-thrust arrangement and is built as an overactuated system, which enables to gain a better robustness and guarantees a stable controlled motion even if some thruster suddenly stop working. Because the heading angle cannot be measured, the reduced attitude control strategy is designed and the stability of reduced state of the system is proved using perturbation method.

A whistle-stop tour of statistics

National Research Council Canada - National Science Library

Everitt, Brian

2012-01-01

"Preface according to my Penguin English dictionary, whistle-stop, used before a noun means 'consisting of brief stops in several places' and this whistle-stop tour of statistics does just that, with...

An adaptable, low cost test-bed for unmanned vehicle systems research

Science.gov (United States)

Goppert, James M.

2011-12-01

An unmanned vehicle systems test-bed has been developed. The test-bed has been designed to accommodate hardware changes and various vehicle types and algorithms. The creation of this test-bed allows research teams to focus on algorithm development and employ a common well-tested experimental framework. The ArduPilotOne autopilot was developed to provide the necessary level of abstraction for multiple vehicle types. The autopilot was also designed to be highly integrated with the Mavlink protocol for Micro Air Vehicle (MAV) communication. Mavlink is the native protocol for QGroundControl, a MAV ground control program. Features were added to QGroundControl to accommodate outdoor usage. Next, the Mavsim toolbox was developed for Scicoslab to allow hardware-in-the-loop testing, control design and analysis, and estimation algorithm testing and verification. In order to obtain linear models of aircraft dynamics, the JSBSim flight dynamics engine was extended to use a probabilistic Nelder-Mead simplex method. The JSBSim aircraft dynamics were compared with wind-tunnel data collected. Finally, a structured methodology for successive loop closure control design is proposed. This methodology is demonstrated along with the rest of the test-bed tools on a quadrotor, a fixed wing RC plane, and a ground vehicle. Test results for the ground vehicle are presented.

Exploring stop-go decision zones at rural high-speed intersections with flashing green signal and insufficient yellow time in China.

Science.gov (United States)

Tang, Keshuang; Xu, Yanqing; Wang, Fen; Oguchi, Takashi

2016-10-01

The objective of this study is to empirically analyze and model the stop-go decision behavior of drivers at rural high-speed intersections in China, where a flashing green signal of 3s followed by a yellow signal of 3s is commonly applied to end a green phase. 1, 186 high-resolution vehicle trajectories were collected at four typical high-speed intersection approaches in Shanghai and used for the identification of actual stop-go decision zones and the modeling of stop-go decision behavior. Results indicate that the presence of flashing green significantly changed the theoretical decision zones based on the conventional Dilemma Zone theory. The actual stop-go decision zones at the study intersections were thus formulated and identified based on the empirical data. Binary Logistic model and Fuzzy Logic model were then developed to further explore the impacts of flashing green on the stop-go behavior of drivers. It was found that the Fuzzy Logic model could produce comparably good estimation results as compared to the traditional Binary Logistic models. The findings of this study could contribute the development of effective dilemma zone protection strategies, the improvement of stop-go decision model embedded in the microscopic traffic simulation software and the proper design of signal change and clearance intervals at high-speed intersections in China. Copyright © 2016 Elsevier Ltd. All rights reserved.

Control strategy of hydraulic/electric synergy system in heavy hybrid vehicles

Energy Technology Data Exchange (ETDEWEB)

Sun Hui; Yang Lifu; Junqing Jing; Yanling Luo [Jiangsu Xuzhou Construction Machinery Research Institute, Jiangsu (China)

2011-01-15

Energy consumption and exhaust emissions of hybrid vehicles strongly depend on the energy storage source and the applied control strategy. Heavy vehicles have the characteristics of frequent starts/stops and significant amounts of braking energy, which needs to find a more efficient way to store and use the high power flow. A novel parallel hybrid vehicles configuration consisting of hydraulic/electric synergy system is proposed to overcome the existing drawbacks of single energy storage source in heavy hybrid vehicles. A control strategy combining a logic threshold approach and key parameters optimization algorithm is developed to achieve acceptable vehicle performance while simultaneously maximizing engine fuel economy and maintaining the battery state of charge in its rational operation range at all times. The experimental and simulation results illustrate the potential of the proposed control strategy in terms of fuel economy and in keeping the deviations of SOC at high efficiency range. (author)

Control strategy of hydraulic/electric synergy system in heavy hybrid vehicles

International Nuclear Information System (INIS)

Sun Hui; Yang Lifu; Jing Junqing; Luo Yanling

2011-01-01

Energy consumption and exhaust emissions of hybrid vehicles strongly depend on the energy storage source and the applied control strategy. Heavy vehicles have the characteristics of frequent starts/stops and significant amounts of braking energy, which needs to find a more efficient way to store and use the high power flow. A novel parallel hybrid vehicles configuration consisting of hydraulic/electric synergy system is proposed to overcome the existing drawbacks of single energy storage source in heavy hybrid vehicles. A control strategy combining a logic threshold approach and key parameters optimization algorithm is developed to achieve acceptable vehicle performance while simultaneously maximizing engine fuel economy and maintaining the battery state of charge in its rational operation range at all times. The experimental and simulation results illustrate the potential of the proposed control strategy in terms of fuel economy and in keeping the deviations of SOC at high efficiency range.

A unique concept for automatically controlling the braking action of wheeled vehicles during minimum distance stops

Science.gov (United States)

Barthlome, D. E.

1975-01-01

Test results of a unique automatic brake control system are outlined and a comparison is made of its mode of operation to that of an existing skid control system. The purpose of the test system is to provide automatic control of braking action such that hydraulic brake pressure is maintained at a near constant, optimum value during minimum distance stops.

Measurement of stopping power of heavy ions

International Nuclear Information System (INIS)

Kitahara, Tetsuo

1981-01-01

The stopping power of heavy ions is discussed. In the low energy region, heavy ions keep some of their orbital electrons, and have equilibrium electron charge. The stopping power of penetrating particles depends on this effective charge. At present, it is hard to estimate this effective charge theoretically, accordingly, the estimation is made experimentally. Another difficulty in this estimation is that the Born approximation is not effective for heavy ions. In the low energy region, electronic stopping and nuclear stopping contribute to the stopping power. For the electronic stopping, a formula for the stopping power was given by Lindhard et al. The experimental values were obtained at GSI, and are inconsistent with the estimation by the Lindhard's formula. In the high energy region, where the Born approximation can be used, the Bethe's formula is applied, but the experimental data are scarce. Oscillations are seen in the Z dependence graph of the experimental stopping cross sections. Experimental works on the stopping power have been done. The differential and the integral methods were carried out. (Kato, T.)

Test bed for applications of heterogeneous unmanned vehicles

Directory of Open Access Journals (Sweden)

Filiberto Muñoz Palacios

2017-01-01

Full Text Available This article addresses the development and implementation of a test bed for applications of heterogeneous unmanned vehicle systems. The test bed consists of unmanned aerial vehicles (Parrot AR.Drones versions 1 or 2, Parrot SA, Paris, France, and Bebop Drones 1.0 and 2.0, Parrot SA, Paris, France, ground vehicles (WowWee Rovio, WowWee Group Limited, Hong Kong, China, and the motion capture systems VICON and OptiTrack. Such test bed allows the user to choose between two different options of development environments, to perform aerial and ground vehicles applications. On the one hand, it is possible to select an environment based on the VICON system and LabVIEW (National Instruments or robotics operating system platforms, which make use the Parrot AR.Drone software development kit or the Bebop_autonomy Driver to communicate with the unmanned vehicles. On the other hand, it is possible to employ a platform that uses the OptiTrack system and that allows users to develop their own applications, replacing AR.Drone’s original firmware with original code. We have developed four experimental setups to illustrate the use of the Parrot software development kit, the Bebop Driver (AutonomyLab, Simon Fraser University, British Columbia, Canada, and the original firmware replacement for performing a strategy that involves both ground and aerial vehicle tracking. Finally, in order to illustrate the effectiveness of the developed test bed for the implementation of advanced controllers, we present experimental results of the implementation of three consensus algorithms: static, adaptive, and neural network, in order to accomplish that a team of multiagents systems move together to track a target.

Reducing Traffic Congestions by Introducing CACC-Vehicles on a Multi-Lane Highway Using Agent-Based Approach

Science.gov (United States)

Arnaout, Georges M.; Bowling, Shannon R.

2011-01-01

Traffic congestion is an ongoing problem of great interest to researchers from different areas in academia. With the emerging technology for inter-vehicle communication, vehicles have the ability to exchange information with predecessors by wireless communication. In this paper, we present an agent-based model of traffic congestion and examine the impact of having CACC (Cooperative Adaptive Cruise Control) embedded vehicle(s) on a highway system consisting of 4 traffic lanes without overtaking. In our model, CACC vehicles adapt their acceleration/deceleration according to vehicle-to-vehicle inter-communication. We analyze the average speed of the cars, the shockwaves, and the evolution of traffic congestion throughout the lifecycle of the model. The study identifies how CACC vehicles affect the dynamics of traffic flow on a complex network and reduce the oscillatory behavior (stop and go) resulting from the acceleration/deceleration of the vehicles.

Technologies for low-bandwidth high-latency unmanned ground vehicle control

Science.gov (United States)

Pace, Teresa; Cogan, Ken; Hunt, Lee; Restine, Paul

2014-05-01

Automation technology has evolved at a rapid pace in recent years; however, many real-world problems require contextual understanding, problem solving, and other forms of higher-order thinking that extends beyond the capabilities of robots for the foreseeable future. This limits the complexity of automation which can be supplied to modern unmanned ground robots (UGV) and necessitates human-in-the-loop monitoring and control for some portions of missions. In order for the human operator to make decisions and provide tasking during key portions of the mission, existing solutions first derive significant information from a potentially dense reconstruction of the scene utilizing LIDAR, video, and other onboard sensors. A dense reconstruction contains too much data for real-time transmission over a modern wireless data link, so the robot electronics must first condense the scene representation prior to transmission. The control station receives this condensed scene representations and provides visual information to the human operator; the human operator then provides tele-operation commands in real-time to the robot. This paper discusses approaches to dense scene reduction of the data required to transmit to a human-in-the loop as well as the challenges associated with them. In addition, the complex and unstructured nature of real-world environments increases the need for tele-operation. Furthermore, many environments reduce the bandwidth and increase the latency of the link. Ultimately, worsening conditions will cause the tele-operation control process to break down, rendering the robot ineffective. In a worst-case scenario, extreme conditions causing a complete loss-of-communications could result in mission failure and loss of the vehicle.

Launch and Landing Effects Ground Operations (LLEGO) Model

Science.gov (United States)

2008-01-01

LLEGO is a model for understanding recurring launch and landing operations costs at Kennedy Space Center for human space flight. Launch and landing operations are often referred to as ground processing, or ground operations. Currently, this function is specific to the ground operations for the Space Shuttle Space Transportation System within the Space Shuttle Program. The Constellation system to follow the Space Shuttle consists of the crewed Orion spacecraft atop an Ares I launch vehicle and the uncrewed Ares V cargo launch vehicle. The Constellation flight and ground systems build upon many elements of the existing Shuttle flight and ground hardware, as well as upon existing organizations and processes. In turn, the LLEGO model builds upon past ground operations research, modeling, data, and experience in estimating for future programs. Rather than to simply provide estimates, the LLEGO model s main purpose is to improve expenses by relating complex relationships among functions (ground operations contractor, subcontractors, civil service technical, center management, operations, etc.) to tangible drivers. Drivers include flight system complexity and reliability, as well as operations and supply chain management processes and technology. Together these factors define the operability and potential improvements for any future system, from the most direct to the least direct expenses.

Dynamics of braking vehicles: from Coulomb friction to anti-lock braking systems

International Nuclear Information System (INIS)

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 without sliding. The advantage of using an anti-lock braking system (ABS) is put in evidence, and a quantitative estimate of its efficiency is proposed and discussed

US Army TARDEC Ground Vehicle Mobility: Dynamics Modeling, Simluation, and Research

Science.gov (United States)

2011-10-24

DRIVEN. WARFIGHTER FOCUSED. For official use only Stair Climbing of a Small Robot Robotic Vehicle Step Climbing UNCLASSIFIED For official use only...NOTES NASA Jet Propulsion Laboratory, mobility, and robotics section. Briefing to the jet propulsion lab. 14. ABSTRACT N/A 15. SUBJECT TERMS 16...JLTV GCV M2 M915 ASV FTTS HMMWV Platforms Supported APDSmall Robot UNCLASSIFIED For official use only Mobility Events • Vehicle stability • Ride

20 CFR 662.430 - Under what conditions may One-Stop operators designated to operate in a One-Stop delivery system...

Science.gov (United States)

2010-04-01

... designated to operate in a One-Stop delivery system established prior to the enactment of WIA be designated... DESCRIPTION OF THE ONE-STOP SYSTEM UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT One-Stop Operators § 662.430 Under what conditions may One-Stop operators designated to operate in a One-Stop delivery system...

Selected Topics on Decision Making for Electric Vehicles

Science.gov (United States)

Sweda, Timothy Matthew

Electric vehicles (EVs) are an attractive alternative to conventional gasoline-powered vehicles due to their lower emissions, fuel costs, and maintenance costs. Range anxiety, or the fear of running out of charge prior to reaching one's destination, remains a significant concern, however. In this dissertation, we address the issue of range anxiety by developing a set of decision support tools for both charging infrastructure providers and EV drivers. In Chapter 1, we present an agent-based information system for identifying patterns in residential EV ownership and driving activities to enable strategic deployment of new charging infrastructure. Driver agents consider their own driving activities within the simulated environment, in addition to the presence of charging stations and the vehicle ownership of others in their social networks, when purchasing a new vehicle. The Chicagoland area is used as a case study to demonstrate the model, and several deployment scenarios are analyzed. In Chapter 2, we address the problem of finding an optimal recharging policy for an EV along a given path. The path consists of a sequence of nodes, each representing a charging station, and the driver must decide where to stop and how much to recharge at each stop. We present efficient algorithms for finding an optimal policy in general instances with deterministic travel costs and homogeneous charging stations, and also for two specialized cases. In addition, we develop two heuristic procedures that we characterize analytically and explore empirically. We further analyze and test our solution methods on model variations that include stochastic travel costs and nonhomogeneous charging stations. In Chapter 3, we study the problem of finding an optimal routing and recharging policy for an electric vehicle in a grid network. Each node in the network represents a charging station and has an associated probability of being available at any point in time or occupied by another vehicle. We

Automated Guided Vehicle For Phsically Handicapped People - A Cost Effective Approach

Science.gov (United States)

Kumar, G. Arun, Dr.; Sivasubramaniam, Mr. A.

2017-12-01

Automated Guided vehicle (AGV) is like a robot that can deliver the materials from the supply area to the technician automatically. This is faster and more efficient. The robot can be accessed wirelessly. A technician can directly control the robot to deliver the components rather than control it via a human operator (over phone, computer etc. who has to program the robot or ask a delivery person to make the delivery). The vehicle is automatically guided through its ways. To avoid collisions a proximity sensor is attached to the system. The sensor senses the signals of the obstacles and can stop the vehicle in the presence of obstacles. Thus vehicle can avoid accidents that can be very useful to the present industrial trend and material handling and equipment handling will be automated and easy time saving methodology.

EADS Roadmap for Launch Vehicles

Science.gov (United States)

Eymar, Patrick; Grimard, Max

2002-01-01

still think about the future, especially at industry level in order to make the most judicious choices in technologies, vehicle types as well as human resources and facilities specialization (especially after recent merger moves). and production as prime contractor, industrial architect or stage provider have taken benefit of this expertise and especially of all the studies ran under national funding and own financing on reusable vehicles and ground/flight demonstrators have analyzed several scenarios. VEHICLES/ASTRIUM SI strategy w.r.t. launch vehicles for the two next decades. Among the main inputs taken into account of course visions of the market evolutions have been considered, but also enlargement of international cooperations and governments requests and supports (e.g. with the influence of large international ventures). 1 patrick.eymar@lanceurs.aeromatra.com 2

Perceptual assessment of fricative--stop coarticulation.

Science.gov (United States)

Repp, B H; Mann, V A

1981-04-01

The perceptual dependence of stop consonants on preceding fricatives [Mann and Repp, J. Acoust. Soc. Am. 69, 548--558 (1981)] was further investigated in two experiments employing both natural and synthetic speech. These experiments consistently replicated our original finding that listeners, report velar stops following [s]. In addition, our data confirmed earlier reports that natural fricative noises (excerpted from utterances of [st alpha], [sk alpha], [(formula: see text)k alpha]) contain cues to the following stop consonants; this was revealed in subjects' identifications of stops from isolated fricative noises and from stimuli consisting of these noises followed by synthetic CV portions drawn from a [t alpha]--[k alpha] continuum. However, these cues in the noise portion could not account for the contextual effect of fricative identity ([formula: see text] versus [sp) on stop perception (more "k" responses following [s]). Rather, this effect seems to be related to a coarticulatory influence of a preceding fricative on stop production; Subjects' responses to excised natural CV portions (with bursts and aspiration removed) were biased towards a relatively more forward place of stop articulation when the CVs had originally been preceded by [s]; and the identification of a preceding ambiguous fricative was biased in the direction of the original fricative context in which a given CV portion had been produced. These findings support an articulatory explanation for the effect of preceding fricatives on stop consonant perception.

Comparative study for "36 V" vehicle applications: advantages of lead-acid batteries

Science.gov (United States)

Lailler, Patrick; Sarrau, Jean-François; Sarrazin, Christian

From thermal engine equipped vehicles to completely electric ones, evolution of light weight vehicles in the future will take several steps in so far as there is no adequate battery or fuel cell presently available to power these vehicles for "on the road" driving. On the other hand, for city driving, vehicles can be improved a lot in terms of fuel efficiency as well as air pollution, if partly or totally electric propulsion can be developed, manufactured and marketed for appropriate applications. The 36-42 V battery is part of this orientation towards improving the efficiency of thermal vehicles in city driving, while keeping adequate autonomy on the roads. Actually, in city traffic, thermal engines are idle most of the time and stop periods represent a large part of the time spent "driving", using up fuel and polluting air for no use at all. The idea of stopping the engine during these periods, if appropriately managed, might potentially lead to a large improvement in fuel economy as well as air pollution reduction. The association of a higher voltage battery to an alternator-starter device in thermal vehicles, seems to be an interesting way towards that end. In this paper, we are presenting our results of a study we have just completed in relationship with RENAULT & VALEO, supported by the French Ministry of Industry, concerning a comparative evaluation of different automobile energy storage systems, and the definition of specifications as the final step of this study. The main conclusion is that lead-acid will still remain dominant in this role, since its operational cost versus efficiency is by far the lowest of every battery presently considered, more particularly in the less expensive car segments.

Stopping of hypervelocity clusters in solids

International Nuclear Information System (INIS)

Anders, Christian; Ziegenhain, Gerolf; Urbassek, Herbert M; Bringa, Eduardo M

2011-01-01

Using molecular-dynamics simulations, we study the processes underlying the stopping of energetic clusters upon impact in matter. We investigate self-bombardment of both a metallic (Cu) and a van-der-Waals bonded (frozen Ar) target. Clusters with sizes up to N = 10 4 atoms and with energies per atom of E/N = 0.1-1600 eV atom -1 were studied. We find that the stopping force exerted on a cluster follows an N 2/3 -dependence with cluster size N; thus large clusters experience less stopping than equi-velocity atoms. In the course of being stopped, the cluster is strongly deformed and attains a roughly pancake shape. Due to the cluster inertia, maximum deformation occurs later than the maximum stopping force. The time scale of projectile stopping is set by t 0 , the time the cluster needs to cover its own diameter before impacting the target; it thus depends on both cluster size and velocity. The time when the cluster experiences its maximum stopping force is around (0.7-0.8)t 0 . We find that the cluster is deformed with huge strain rates of around 1/2t 0 ; this amounts to 10 11 -10 13 s -1 for the cases studied here. (paper)

Connected variable speed limits control and car-following control with vehicle-infrastructure communication to resolve stop-and-go waves

NARCIS (Netherlands)

Wang, M.; Daamen, W.; Hoogendoorn, S.P.; van Arem, B.

2016-01-01

The vision of intelligent vehicles traveling in road networks has prompted numerous concepts to control future traffic flow, one of which is the in-vehicle actuation of traffic control commands. The key of this concept is using intelligent vehicles as actuators for traffic control systems. Under

Pre-flight physical simulation test of HIMES reentry test vehicle

Science.gov (United States)

Kawaguchi, Jun'ichiro; Inatani, Yoshifumi; Yonemoto, Koichi; Hosokawa, Shigeru

ISAS is now developing a small reentry test vehicle, which is 2m long with a 1.5m wing span and weighs about 170 kg, for the purpose of exploring high angle-of-attack aerodynamic attitude control issue in supersonic and hypersonic speed. The flight test, employing 'Rockoon' launch system, is planned as a preliminary design verification for a fully reusable winged rocket named HIMES (Highly Maneuverable Experimental Space) vehicle. This paper describes the results of preflight ground test using a motion table system. This ground system test is called 'physical simulation' aimed at: (1) functional verification of side-jet system, aerodynamic surface actuators, battery and onboard avionics; and (2) guidance and control law evaluation, in total hardware-in-the-loop system. The pressure of side-jet nozzles was measured to provide exact thrust characteristics of reaction control. The dynamics of vehicle motion was calculated in real-time by the ground simulation computer.

Tasking and control of a squad of robotic vehicles

Science.gov (United States)

Lewis, Christopher L.; Feddema, John T.; Klarer, Paul

2001-09-01

Sandia National Laboratories have developed a squad of robotic vehicles as a test-bed for investigating cooperative control strategies. The squad consists of eight RATLER vehicles and a command station. The RATLERs are medium-sized all-electric vehicles containing a PC104 stack for computation, control, and sensing. Three separate RF channels are used for communications; one for video, one for command and control, and one for differential GPS corrections. Using DGPS and IR proximity sensors, the vehicles are capable of autonomously traversing fairly rough terrain. The control station is a PC running Windows NT. A GUI has been developed that allows a single operator to task and monitor all eight vehicles. To date, the following mission capabilities have been demonstrated: 1. Way-Point Navigation, 2. Formation Following, 3. Perimeter Surveillance, 4. Surround and Diversion, and 5. DGPS Leap Frog. This paper describes the system and briefly outlines each mission capability. The DGPS Leap Frog capability is discussed in more detail. This capability is unique in that it demonstrates how cooperation allows the vehicles to accurately navigate beyond the RF communication range. One vehicle stops and uses its corrected GPS position to re-initialize its receiver to become the DGPS correction station for the other vehicles. Error in position accumulates each time a new vehicle takes over the DGPS duties. The accumulation in error is accurately modeled as a random walk phenomenon. This paper demonstrates how useful accuracy can be maintained beyond the vehicle's range.

The Special Purpose Vehicle

DEFF Research Database (Denmark)

Fomcenco, Alex

2013-01-01

The purpose of this article is to investigate whether the situation where two companies appear as originators or sponsors behind a Special Purpose Vehicle (SPV) can be described as a merger, although on micro scale. Are the underlying grounds behind the creation of an SPV much different than those...

Evaluating the Effects of Traffic on Driver Stopping and Turn Signal Use at a Stop Sign: A Systematic Replication

Science.gov (United States)

Lebbon, Angela R.; Austin, John; Van Houten, Ron; Malenfant, Louis E.

2007-01-01

The current analyses of observational data found that oncoming traffic substantially affected driver stopping patterns and turn signal use at the target stop sign. The percentage of legal stops and turn signal use by drivers in the presence and absence of traffic was analyzed using a multi-element design. The results showed that legal stops were…

How Can I Stop Cutting?

Science.gov (United States)

... Educators Search English Español How Can I Stop Cutting? KidsHealth / For Teens / How Can I Stop Cutting? ... in a soft, cozy blanket Substitutes for the Cutting Sensation You'll notice that all the tips ...

Intelligent Bus Stops in the Flexible Bus Systems

Directory of Open Access Journals (Sweden)

Razi Iqbal

2014-09-01

Full Text Available The purpose of this paper is to discuss Intelligent Bus Stops in a special Demand Responsive Transit (DRT, the Flexible Bus System. These Intelligent Bus Stops are more efficient and information rich than Traditional Bus Stops. The real time synchronization of the Flexible Bus System makes it unique as compared to Traditional Bus Systems. The Main concern is to make Bus Stops intelligent and information rich. Buses are informed about the no. of passengers waiting at the upcoming Bus Stops. If there are no passengers to ride or get off on upcoming Bus Stop, the Bus can skip that Bus Stop and head towards the next Bus Stop where passenger is waiting, which will decrease the ride time of the passengers on the Bus and also the wait time of the passengers waiting on the upcoming Bus Stops. Providing more information at Bus Stops about the Destination (Time to Destination, Distance to Destination etc. and Buses (Bus Location, Arrival Time of Bus etc. makes it easier for the passengers to decide whether to ride a particular Bus or not.

A simulation study on proton computed tomography (CT) stopping power accuracy using dual energy CT scans as benchmark.

Science.gov (United States)

Hansen, David C; Seco, Joao; Sørensen, Thomas Sangild; Petersen, Jørgen Breede Baltzer; Wildberger, Joachim E; Verhaegen, Frank; Landry, Guillaume

2015-01-01

Accurate stopping power estimation is crucial for treatment planning in proton therapy, and the uncertainties in stopping power are currently the largest contributor to the employed dose margins. Dual energy x-ray computed tomography (CT) (clinically available) and proton CT (in development) have both been proposed as methods for obtaining patient stopping power maps. The purpose of this work was to assess the accuracy of proton CT using dual energy CT scans of phantoms to establish reference accuracy levels. A CT calibration phantom and an abdomen cross section phantom containing inserts were scanned with dual energy and single energy CT with a state-of-the-art dual energy CT scanner. Proton CT scans were simulated using Monte Carlo methods. The simulations followed the setup used in current prototype proton CT scanners and included realistic modeling of detectors and the corresponding noise characteristics. Stopping power maps were calculated for all three scans, and compared with the ground truth stopping power from the phantoms. Proton CT gave slightly better stopping power estimates than the dual energy CT method, with root mean square errors of 0.2% and 0.5% (for each phantom) compared to 0.5% and 0.9%. Single energy CT root mean square errors were 2.7% and 1.6%. Maximal errors for proton, dual energy and single energy CT were 0.51%, 1.7% and 7.4%, respectively. Better stopping power estimates could significantly reduce the range errors in proton therapy, but requires a large improvement in current methods which may be achievable with proton CT.

TARDEC Overview: Ground Vehicle Power and Mobility

Science.gov (United States)

2011-02-04

Fuel & Water Distribution • Force Sustainment • Construction Equipment • Bridging • Assured Mobility Systems Robotics • TALON • PackBot • MARCbot...Equipment • Mechanical Countermine Equipment • Tactical Bridging Intelligent Ground Systems • Autonomous Robotics Systems • Safe Operations...Test Cell • Hybrid Electric Reconfigurable Moveable Integration Testbed (HERMIT) • Electro-chemical Analysis and Research Lab (EARL) • Battery Lab • Air

The Application of the Human Engineering Modeling and Performance Laboratory for Space Vehicle Ground Processing Tasks at Kennedy Space Center

Science.gov (United States)

Woodbury, Sarah K.

2008-01-01

The introduction of United Space Alliance's Human Engineering Modeling and Performance Laboratory began in early 2007 in an attempt to address the problematic workspace design issues that the Space Shuttle has imposed on technicians performing maintenance and inspection operations. The Space Shuttle was not expected to require the extensive maintenance it undergoes between flights. As a result, extensive, costly resources have been expended on workarounds and modifications to accommodate ground processing personnel. Consideration of basic human factors principles for design of maintenance is essential during the design phase of future space vehicles, facilities, and equipment. Simulation will be needed to test and validate designs before implementation.

Biobjective Optimization and Evaluation for Transit Signal Priority Strategies at Bus Stop-to-Stop Segment

Directory of Open Access Journals (Sweden)

Rui Li

2016-01-01

Full Text Available This paper proposes a new optimization framework for the transit signal priority strategies in terms of green extension, red truncation, and phase insertion at the stop-to-stop segment of bus lines. The optimization objective is to minimize both passenger delay and the deviation from bus schedule simultaneously. The objective functions are defined with respect to the segment between bus stops, which can include the adjacent signalized intersections and downstream bus stops. The transit priority signal timing is optimized by using a biobjective optimization framework considering both the total delay at a segment and the delay deviation from the arrival schedules at bus stops. The proposed framework is evaluated using a VISSIM model calibrated with field traffic volume and traffic signal data of Caochangmen Boulevard in Nanjing, China. The optimized TSP-based phasing plans result in the reduced delay and improved reliability, compared with the non-TSP scenario under the different traffic flow conditions in the morning peak hour. The evaluation results indicate the promising performance of the proposed optimization framework in reducing the passenger delay and improving the bus schedule adherence for the urban transit system.

Project Guardian: Optimizing Electronic Warfare Systems for Ground Combat Vehicles

National Research Council Canada - National Science Library

Parks, Jack G; Jackson, William; Revello, James; Soltesz, James

1995-01-01

.... The study, Project Guardian, represents a new process for determining the optimum set of sensors and countermeasures for a specific vehicle class under the constraints of threat projection, combat...

Emerging Needs for Pervasive Passive Wireless Sensor Networks on Aerospace Vehicles

Science.gov (United States)

Wilson, William C.; Juarez, Peter D.

2014-01-01

NASA is investigating passive wireless sensor technology to reduce instrumentation mass and volume in ground testing, air flight, and space exploration applications. Vehicle health monitoring systems (VHMS) are desired on all aerospace programs to ensure the safety of the crew and the vehicles. Pervasive passive wireless sensor networks facilitate VHMS on aerospace vehicles. Future wireless sensor networks on board aerospace vehicles will be heterogeneous and will require active and passive network systems. Since much has been published on active wireless sensor networks, this work will focus on the need for passive wireless sensor networks on aerospace vehicles. Several passive wireless technologies such as microelectromechanical systems MEMS, SAW, backscatter, and chipless RFID techniques, have all shown potential to meet the pervasive sensing needs for aerospace VHMS applications. A SAW VHMS application will be presented. In addition, application areas including ground testing, hypersonic aircraft and spacecraft will be explored along with some of the harsh environments found in aerospace applications.

Seismic Risk of the Base Isolation System Protected by the Hard Stop

International Nuclear Information System (INIS)

Kim, Jung Han; Choi, In-Kil; Kim, Min Kyu

2015-01-01

The concept of base isolation is to permit the deformation of isolator for absorbing seismic input wave from the ground. In a nuclear power plant design, allowable shear deformation of isolators should be enough to absorb the displacement response by extended design basis (EDB) ground motions. However isolators cannot resist over its displacement capacity. So, the clearance of hard stop (CHS) needs to be set between the response of base isolation system excited by the EDB ground motion and the displacement capacity of isolators. The isolation system must survive with high confidence in any seismic accident because it is a non-redundant system. Therefore, the CHS should be determined carefully based on the failure risk of base isolation system considering the uncertainties of earthquake responses and isolator capacities. In this research, the fragility curve of isolation system and its failure risk were estimated. The procedure to calculate the acceleration based fragility curve of the isolation system was developed. The fragility curve and failure risk for example case was estimated and its result was compared with different isolator capacities

Seismic Risk of the Base Isolation System Protected by the Hard Stop

Energy Technology Data Exchange (ETDEWEB)

Kim, Jung Han; Choi, In-Kil; Kim, Min Kyu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2015-10-15

The concept of base isolation is to permit the deformation of isolator for absorbing seismic input wave from the ground. In a nuclear power plant design, allowable shear deformation of isolators should be enough to absorb the displacement response by extended design basis (EDB) ground motions. However isolators cannot resist over its displacement capacity. So, the clearance of hard stop (CHS) needs to be set between the response of base isolation system excited by the EDB ground motion and the displacement capacity of isolators. The isolation system must survive with high confidence in any seismic accident because it is a non-redundant system. Therefore, the CHS should be determined carefully based on the failure risk of base isolation system considering the uncertainties of earthquake responses and isolator capacities. In this research, the fragility curve of isolation system and its failure risk were estimated. The procedure to calculate the acceleration based fragility curve of the isolation system was developed. The fragility curve and failure risk for example case was estimated and its result was compared with different isolator capacities.

Control techniques for an automated mixed traffic vehicle

Science.gov (United States)

Meisenholder, G. W.; Johnston, A. R.

1977-01-01

The paper describes an automated mixed traffic vehicle (AMTV), a driverless low-speed tram designed to operate in mixed pedestrian and vehicular traffic. The vehicle is a six-passenger electric tram equipped with sensing and control which permit it to function on existing streets in an automatic mode. The design includes established wire-following techniques for steering and near-IR headway sensors. A 7-mph cruise speed is reduced to 2 mph or a complete stop in response to sensor (or passenger) inputs. The AMTV performance is evaluated by operation on a loop route and by simulation. Some necessary improvements involving sensors, sensor pattern, use of an audible signal, and control lag are discussed. It is suggested that appropriate modifications will eliminate collision incidents.

Analyzing Real-World Light Duty Vehicle Efficiency Benefits

Energy Technology Data Exchange (ETDEWEB)

Gonder, Jeffrey; Wood, Eric; Chaney, Larry; Holden, Jacob; Jeffers, Matthew; Wang, Lijuan

2016-06-08

Off-cycle technologies represent an important pathway to achieve real-world fuel savings, through which OEMs can potentially receive credit toward CAFE compliance. DOE national labs such as NREL are well positioned to provide objective input on these technologies using large, national data sets in conjunction with OEM- and technology-specific testing. This project demonstrates an approach that combines vehicle testing (dynamometer and on-road) with powertrain modeling and simulation over large, representative datasets to quantify real-world fuel economy. The approach can be applied to specific off-cycle technologies (engine encapsulation, start/stop, connected vehicle, etc.) in A/B comparisons to support calculation of realistic real-world impacts. Future work will focus on testing-based A/B technology comparisons that demonstrate the significance of this approach.

Electric energy storage systems for future hybrid vehicles

Energy Technology Data Exchange (ETDEWEB)

Kemper, Hans; Huelshorst, Thomas [FEV Motorentechnik GmbH, Aachen (Germany); Sauer, Dirk Uwe [Elektrochemische Energiewandlung und Speichersystemtechnik, ISEA, RWTH Aachen Univ. (Germany)

2008-07-01

Electric energy storage systems play a key role in today's and even more in future hybrid and electric vehicles. They enable new additional functionalities like Start/Stop, regenerative braking or electric boost and pure electric drive. This article discusses properties and requirements of battery systems like power provision, energy capacity, life time as a function of the hybrid concepts and the real operating conditions of the today's and future hybrid drivetrains. Battery cell technology, component sizing, system design, operating strategy safety measures and diagnosis, modularity and vehicle integration are important battery development topics. A final assessment will draw the conclusion that future drivetrain concepts with higher degree of electrician will be significantly dependent on the progress of battery technology. (orig.)

Bubble formation after a 20-m dive: deep-stop vs. shallow-stop decompression profiles

NARCIS (Netherlands)

Schellart, Nico A. M.; Corstius, Jan-Jaap Brandt; Germonpré, Peter; Sterk, Wouter

2008-01-01

OBJECTIVES: It is claimed that performing a "deep stop," a stop at about half of maximal diving depth (MDD), can reduce the amount of detectable precordial bubbles after the dive and may thus diminish the risk of decompression sickness. In order to ascertain whether this reduction is caused by the

Optimal Control of Engine Warmup in Hybrid Vehicles

Directory of Open Access Journals (Sweden)

van Reeven Vital

2016-01-01

Full Text Available An Internal Combustion Engine (ICE under cold conditions experiences increased friction losses due to a high viscosity of the lubricant. With the additional control freedom present in hybrid electric vehicles, the losses during warmup can be minimized and fuel can be saved. In this paper, firstly, a control-oriented model of the ICE, describing the warmup behavior, is developed and validated on measured vehicle data. Secondly, the two-state, non-autonomous fuel optimization, for a parallel hybrid electric vehicle with stop-start functionality, is solved using optimal control theory. The principal behavior of the Lagrange multipliers is explicitly derived, including the discontinuities (jumps that are caused by the constraints on the lubricant temperature and the energy in the battery system. The minimization of the Hamiltonian for this two-state problem is also explicitly solved, resulting in a computationally efficient algorithm. The optimal controller shows the fuel benefit, as a function of the initial temperature, for a long-haul truck simulated on the FTP-75.

Design of Fuzzy Enhanced Hierarchical Motion Stabilizing Controller of Unmanned Ground Vehicle in Three DimensionalSpace

Directory of Open Access Journals (Sweden)

Yue Ma

2011-12-01

Full Text Available In this paper, stabilizing control of tracked unmanned ground vehicle in 3-D space was presented. Firstly, models of major modules of tracked UGV were established. Next, to reveal the mechanism of disturbances applied on the UGV, two kinds of representative disturbances (slope and general disturbances in yaw motion were discussed in depth. Consequently, an attempting PID method was employed to compensate the impacts of disturbances andsimulation results proved the validity for disturbance incited by slope force, but revealed the lack for general disturbance on yaw motion. Finally, a hierarchical fuzzy controller combined with PID controller was proposed. In lower level, there were two PID controllers to compensate the disturbance of slope force, and on top level, the fuzzy logic controller was employed to correct the yaw motion error based on the differences between the model and the real UGV, which was able to guide the UGV maintain on the stable state. Simulation results demonstrated the excellent effectiveness of the newly designed controller.

Bidirectional DC-DC converter fed drive for electric vehicle system ...

African Journals Online (AJOL)

Batteries are the primary energy-storage devices in ground vehicles. Now days battery fed electric drives are commonly being used for electric vehicles applications, due to various advantages, such as: nearly zero emission, guaranteed load leveling, good transient operation and energy recovery during braking operation.

Traffic lanes for vehicles of mass public passenger transport on city streets

Directory of Open Access Journals (Sweden)

Gladović Pavle V.

2015-01-01

Full Text Available Some of the basic measures of regulating public mass passenger transport in a city network are the introduction and management of traffic lanes reserved for the public transportation. These traffic lanes are important for several reasons: faster moving and shorter travelling time for the vehicles, reducing operating costs, improving the safety, increasing passenger comfort, maintaining of the timetable quality, etc. In most cities, an intensive use of the public transport is concentrated in the morning and the afternoon peak period. The state of the public transport system during these periods is reflected in the crowds inside the vehicles, long vehicle queues at intersections and at bus stops, which cause congestion on the streets and result in delays of public transport vehicles. This paper provides an overview of the current situation on an example in the city of Belgrade. The capacity and the quality of service for the street surfaces reserved for the public transportation vehicles were analysed on the aforementioned example.

Developing a short range vehicle to infrastructure communication system to enhance the safety at STOP sign intersections : final report.

Science.gov (United States)

2016-05-01

Stop sign controlled unsignalized intersections raise a public safe concern. Even though various strategies, such as engineering, education, and policy, have been applied in practice, there are a number of fatal crashes occurred at unsignalized inter...

Innovative control systems for tracked vehicle platforms

CERN Document Server

2014-01-01

 This book has been motivated by an urgent need for designing and implementation of innovative control algorithms and systems for tracked vehicles. Nowadays the unmanned vehicles are becoming more and more common. Therefore there is a need for innovative mechanical constructions capable of adapting to various applications regardless the ground, air or water/underwater environment. There are multiple various activities connected with tracked vehicles. They can be distributed among three main groups: design and control algorithms, sensoric and vision based in-formation, construction and testing mechanical parts of unmanned vehicles. Scientists and researchers involved in mechanics, control algorithms, image processing, computer vision, data fusion, or IC will find this book useful.

Motion Control of Four-Wheel Independently Actuated Electric Ground Vehicles considering Tire Force Saturations

Directory of Open Access Journals (Sweden)

Rongrong Wang

2013-01-01

Full Text Available A vehicle stability control approach for four-wheel independently actuated (FWIA electric vehicles is presented. The proposed control method consists of a higher-level controller and a lower-level controller. An adaptive control-based higher-level controller is designed to yield the vehicle virtual control efforts to track the desired vehicle motions due to the possible modeling inaccuracies and parametric uncertainties. The lower-level controller considering tire force saturation is given to allocate the required control efforts to the four in-wheel motors for providing the desired tire forces. An analytic method is given to distribute the high-level control efforts, without using the numerical-optimization-based control allocation algorithms. Simulations based on a high-fidelity, CarSim, and full-vehicle model show the effectiveness of the control approach.

Optimal Stopping and Policyholder Behaviour in Life Insurance

DEFF Research Database (Denmark)

Gad, Kamille Sofie Tågholt

. Below, I give a brief overview of the results of each of the chapters. A more thorough overview is presented in Chapter 1. In Chapter 2 we consider a general geometric Lévy process and solve the non-linear optimal stopping problem of maximizing the variance at the stopping time. For solving this problem...... we solve an auxiliary quadratic optimal stopping problem. We show that the solution to maximizing variance depends on whether randomized stopping times are included in the set of stopping times we maximize over. For some problems the inclusion of randomized stopping times increase the value function...... and for some it does not. Even when the value function is not affected by inclusion of randomized stopping times, a solution may be easier to identify when they are. In Chapter 3 we consider the non-linear optimal stopping problem of maximizing the mean minus a positive constant times the variance...

Incorporating vehicle mix in stimulus-response car-following models

Directory of Open Access Journals (Sweden)

Saidi Siuhi

2016-06-01

Full Text Available The objective of this paper is to incorporate vehicle mix in stimulus-response car-following models. Separate models were estimated for acceleration and deceleration responses to account for vehicle mix via both movement state and vehicle type. For each model, three sub-models were developed for different pairs of following vehicles including “automobile following automobile,” “automobile following truck,” and “truck following automobile.” The estimated model parameters were then validated against other data from a similar region and roadway. The results indicated that drivers' behaviors were significantly different among the different pairs of following vehicles. Also the magnitude of the estimated parameters depends on the type of vehicle being driven and/or followed. These results demonstrated the need to use separate models depending on movement state and vehicle type. The differences in parameter estimates confirmed in this paper highlight traffic safety and operational issues of mixed traffic operation on a single lane. The findings of this paper can assist transportation professionals to improve traffic simulation models used to evaluate the impact of different strategies on ameliorate safety and performance of highways. In addition, driver response time lag estimates can be used in roadway design to calculate important design parameters such as stopping sight distance on horizontal and vertical curves for both automobiles and trucks.

Analysis Methodology for Optimal Selection of Ground Station Site in Space Missions

Science.gov (United States)

Nieves-Chinchilla, J.; Farjas, M.; Martínez, R.

2013-12-01

Optimization of ground station sites is especially important in complex missions that include several small satellites (clusters or constellations) such as the QB50 project, where one ground station would be able to track several spatial vehicles, even simultaneously. In this regard the design of the communication system has to carefully take into account the ground station site and relevant signal phenomena, depending on the frequency band. To propose the optimal location of the ground station, these aspects become even more relevant to establish a trusted communication link due to the ground segment site in urban areas and/or selection of low orbits for the space segment. In addition, updated cartography with high resolution data of the location and its surroundings help to develop recommendations in the design of its location for spatial vehicles tracking and hence to improve effectiveness. The objectives of this analysis methodology are: completion of cartographic information, modelling the obstacles that hinder communication between the ground and space segment and representation in the generated 3D scene of the degree of impairment in the signal/noise of the phenomena that interferes with communication. The integration of new technologies of geographic data capture, such as 3D Laser Scan, determine that increased optimization of the antenna elevation mask, in its AOS and LOS azimuths along the horizon visible, maximizes visibility time with spatial vehicles. Furthermore, from the three-dimensional cloud of points captured, specific information is selected and, using 3D modeling techniques, the 3D scene of the antenna location site and surroundings is generated. The resulting 3D model evidences nearby obstacles related to the cartographic conditions such as mountain formations and buildings, and any additional obstacles that interfere with the operational quality of the antenna (other antennas and electronic devices that emit or receive in the same bandwidth

Planning of Vehicle Routing with Backup Provisioning Using Wireless Sensor Technologies

Directory of Open Access Journals (Sweden)

Noélia Correia

2017-08-01

Full Text Available Wireless sensor technologies can be used by intelligent transportation systems to provide innovative services that lead to improvements in road safety and congestion, increasing end-user satisfaction. In this article, we address vehicle routing with backup provisioning, where the possibility of reacting to overloading/overcrowding of vehicles at certain stops is considered. This is based on the availability of vehicle load information, which can be captured using wireless sensor technologies. After discussing the infrastructure and monitoring tool, the problem is mathematically formalized, and a heuristic algorithm using local search procedures is proposed. Results show that planning routes with backup provisioning can allow fast response to overcrowding while reducing costs. Therefore, sustainable urban mobility, with efficient use of resources, can be provided while increasing the quality of service perceived by users.

Optimally Stopped Optimization

Science.gov (United States)

Vinci, Walter; Lidar, Daniel

We combine the fields of heuristic optimization and optimal stopping. We propose a strategy for benchmarking randomized optimization algorithms that minimizes the expected total cost for obtaining a good solution with an optimal number of calls to the solver. To do so, rather than letting the objective function alone define a cost to be minimized, we introduce a further cost-per-call of the algorithm. We show that this problem can be formulated using optimal stopping theory. The expected cost is a flexible figure of merit for benchmarking probabilistic solvers that can be computed when the optimal solution is not known, and that avoids the biases and arbitrariness that affect other measures. The optimal stopping formulation of benchmarking directly leads to a real-time, optimal-utilization strategy for probabilistic optimizers with practical impact. We apply our formulation to benchmark the performance of a D-Wave 2X quantum annealer and the HFS solver, a specialized classical heuristic algorithm designed for low tree-width graphs. On a set of frustrated-loop instances with planted solutions defined on up to N = 1098 variables, the D-Wave device is between one to two orders of magnitude faster than the HFS solver.

An investigation of the effects of pneumatic actuator design on slip control for heavy vehicles

Science.gov (United States)

Miller, Jonathan I.; Cebon, David

2013-01-01

Progress in reducing actuator delays in pneumatic brake systems is opening the door for advanced anti-lock braking algorithms to be used on heavy goods vehicles. However, little has been published on slip controllers for air-braked heavy vehicles, or the effects of slow pneumatic actuation on their design and performance. This paper introduces a sliding mode slip controller for air-braked heavy vehicles. The effects of pneumatic actuator delays and flow rates on stopping performance and air (energy) consumption are presented through vehicle simulations. Finally, the simulations are validated with experiments using a hardware-in-the-loop rig. It is shown that for each wheel, pneumatic valves with delays smaller than 3 ms and orifice diameters around 8 mm provide the best performance.

Simulating fail-stop in asynchronous distributed systems

Science.gov (United States)

Sabel, Laura; Marzullo, Keith

1994-01-01

The fail-stop failure model appears frequently in the distributed systems literature. However, in an asynchronous distributed system, the fail-stop model cannot be implemented. In particular, it is impossible to reliably detect crash failures in an asynchronous system. In this paper, we show that it is possible to specify and implement a failure model that is indistinguishable from the fail-stop model from the point of view of any process within an asynchronous system. We give necessary conditions for a failure model to be indistinguishable from the fail-stop model, and derive lower bounds on the amount of process replication needed to implement such a failure model. We present a simple one-round protocol for implementing one such failure model, which we call simulated fail-stop.

Frame by frame stop motion non-traditional approaches to stop motion animation

CERN Document Server

Gasek, Tom

2011-01-01

In a world that is dominated by computer images, alternative stop motion techniques like pixilation, time-lapse photography and down-shooting techniques combined with new technologies offer a new, tangible and exciting approach to animation. With over 25 years professional experience, industry veteran, Tom Gasek presents a comprehensive guide to stop motion animation without the focus on puppetry or model animation. With tips, tricks and hands-on exercises, Frame by Frame will help both experienced and novice filmmakers get the most effective results from this underutilized branch of animation

A light sneutrino rescues the light stop

Energy Technology Data Exchange (ETDEWEB)

Chala, M. [Departament de Física Tèorica, Universitat de València and IFIC, Universitat de València-CSIC,Dr. Moliner 50, E-46100 Burjassot (València) (Spain); Delgado, A. [Department of Physics, University of Notre Dame, 225 Nieuwland Science Hall, Notre Dame, IN 46556 (United States); Nardini, G. [Albert Einstein Center (AEC), Institute for Theoretical Physics (ITP), University of Bern,Sidlerstrasse 5, CH-3012 Bern (Switzerland); Quirós, M. [Institut de Física d’Altes Energies (IFAE), The Barcelona Institute of Science and Technology (BIST),Institució Catalana de Recerca i Estudis Avançats - ICREA, Campus UAB, 08193 Bellaterra, Barcelona (Spain)

2017-04-18

Stop searches in supersymmetric frameworks with R-parity conservation usually assume the lightest neutralino to be the lightest supersymmetric particle. In this paper we consider an alternative scenario in which the left-handed tau sneutrino is lighter than neutralinos and stable at collider scales, but possibly unstable at cosmological scales. Moreover the (mostly right-handed) stop t̃ is lighter than all electroweakinos, and heavier than the scalars of the third generation lepton doublet, whose charged component, τ̃, is heavier than the neutral one, ν̃. The remaining supersymmetric particles are decoupled from the stop phenomenology. In most of the parameter space, the relevant stop decays are only into tτ̃τ, tν̃ν and bν̃τ via off-shell electroweakinos. We constrain the branching ratios of these decays by recasting the most sensitive stop searches. Due to the “double invisible” kinematics of the t̃→tν̃ν process, and the low efficiency in tagging the tτ̃τ decay products, light stops are generically allowed. In the minimal supersymmetric standard model with ∼ 100 GeV sneutrinos, stops with masses as small as ∼ 350 GeV turn out to be allowed at 95% CL.

How to Stop Biting Your Nails

Medline Plus

Full Text Available ... Mohs AUC MyDermPath+ Psoriasis Patient education resources ... Try to gradually stop biting your nails: Some doctors recommend taking a gradual approach to break the habit. Try to stop biting ...

Contamination and decontamination of vehicles driven in radioactive areas

International Nuclear Information System (INIS)

Ulvsand, T.; Nygren, U.

1999-03-01

There is reason to ask whether it is beneficial to decontaminate vehicles, in view of the great effort applied. If the level of contamination is low before the decontamination process, then the cost is not motivated, even if the decontamination is shown to be effective in relative terms. The report describes two trials at the National NBC Defence School in Umeaa and one trial at the French test site in Bourges. The aim is to investigate how vehicles are contaminated and at which ground deposition levels troublesome levels of contamination will arise. In the trials, a non-radioactive agent substituting real radioactivity was used. The trials in Sweden so far have used the oversnow vehicle BV 206, during both winter and summer conditions. The vehicles were driven a specific distance along a road on which a known amount of the test substance had been dispersed. Samples were taken on pre-determined areas on one side of the vehicles to measure the amount of test substance. Later, the vehicles continued along a 'clean' road where additional samples were taken, but on the other side of the vehicles. The largest amount of test substance was collected on the tracks and on the back of the vehicle. The tracks and mud-flaps were effectively decontaminated when the vehicles were driven along a clean road, while most of the contamination remained on the backside. The purpose of the trials in France was to compare the results from our non-radioactive and their radioactive method, based on the radioactive La-140. Due to ground conditions, the level of contamination on the vehicles was much less than in the trials in Umeaa, but the effect decontamination could be measured after all

Assessment and preliminary design of an energy buffer for regenerative braking in electric vehicles

Science.gov (United States)

Buchholz, R.; Mathur, A. K.

1979-01-01

Energy buffer systems, capable of storing the vehicle energy during braking and reusing this stored energy during acceleration, were examined. Some of these buffer systems when incorporated in an electric vehicle would result in an improvement in the performance and range under stop and go driving conditions. Buffer systems considered included flywheels, hydropneumatic, pneumatic, spring, and regenerative braking. Buffer ranking and rating criteria were established. Buffer systems were rated based on predicted range improvements, consumer acceptance, driveability, safety, reliability and durability, and initial and life cycle costs. A hydropneumatic buffer system was selected.

R20 Programme: The development of grouting technique. Stop criteria and field tests

International Nuclear Information System (INIS)

Hollmen, K.

2008-01-01

stop criteria for grouting are found: maximum pressure and maximum grouted volume together, GIN-method (Grouting Intensity Number) and GT-method (Grouting Time). Empirically set maximum pressure and grout volume are current prevailing practice for stop criterion. The stop criteria in GIN-method are grouting pressure, grout volume and distinct GIN-number, which is product of maximum pressure and maximum grout volume. Grouting time is the stop criterion in recently presented GT-method. Criterion is analytical and based on relations between grout penetration and grouting time. The field trials to test GT-method were done in ONKALO as a part of normal grouting. The first field test was pre-grouting in access tunnel and the second was shaft-grouting in personnel shaft. On the grounds of the field tests it cannot be committed with certainty if the GT-method is workable as a grouting stop criterion. Therefore further clarifications and test runs for GT-method are needed. (orig.)

Mobility Systems For Robotic Vehicles

Science.gov (United States)

Chun, Wendell

1987-02-01

The majority of existing robotic systems can be decomposed into five distinct subsystems: locomotion, control/man-machine interface (MMI), sensors, power source, and manipulator. When designing robotic vehicles, there are two main requirements: first, to design for the environment and second, for the task. The environment can be correlated with known missions. This can be seen by analyzing existing mobile robots. Ground mobile systems are generally wheeled, tracked, or legged. More recently, underwater vehicles have gained greater attention. For example, Jason Jr. made history by surveying the sunken luxury liner, the Titanic. The next big surge of robotic vehicles will be in space. This will evolve as a result of NASA's commitment to the Space Station. The foreseeable robots will interface with current systems as well as standalone, free-flying systems. A space robotic vehicle is similar to its underwater counterpart with very few differences. Their commonality includes missions and degrees-of-freedom. The issues of stability and communication are inherent in both systems and environment.

The extraction of "2"2"9Th"3"+ from a buffer-gas stopping cell

International Nuclear Information System (INIS)

Wense, L. von der; Seiferle, B.; Laatiaoui, M.; Thirolf, P.G.

2016-01-01

In the whole landscape of atomic nuclei, "2"2"9Th is currently the only known nucleus which could allow for the development of a nuclear-based frequency standard, as it possesses an isomeric state of just 7.6 eV energy above the ground state. The 3+ charge state is of special importance in this context, as Th"3"+ allows for a simple laser-cooling scheme. Here we emphasize the direct extraction of triply-charged "2"2"9Th from a buffer-gas stopping cell. This finding will not only simplify any future approach of "2"2"9Th ion cooling, but is also used for thorium-beam purification and in this way provides a powerful tool for the direct identification of the "2"2"9Th isomer to ground state nuclear transition.

A systematic analysis of the Braitenberg vehicle 2b for point-like stimulus sources

International Nuclear Information System (INIS)

Rañó, Iñaki

2012-01-01

Braitenberg vehicles have been used experimentally for decades in robotics with limited empirical understanding. This paper presents the first mathematical model of the vehicle 2b, displaying so-called aggression behaviour, and analyses the possible trajectories for point-like smooth stimulus sources. This sensory-motor steering control mechanism is used to implement biologically grounded target approach, target-seeking or obstacle-avoidance behaviour. However, the analysis of the resulting model reveals that complex and unexpected trajectories can result even for point-like stimuli. We also prove how the implementation of the controller and the vehicle morphology interact to affect the behaviour of the vehicle. This work provides a better understanding of Braitenberg vehicle 2b, explains experimental results and paves the way for a formally grounded application on robotics as well as for a new way of understanding target seeking in biology. (paper)

Adaptive Surveying and Early Treatment of Crops with a Team of Autonomous Vehicles

DEFF Research Database (Denmark)

Kazmi, Wajahat; Bisgaard, Morten; Garcia-Ruiz, Francisco

2011-01-01

The ASETA project (acronym for Adaptive Surveying and Early treatment of crops with a Team of Autonomous vehicles) is a multi-disciplinary project combining cooperating airborne and ground-based vehicles with advanced sensors and automated analysis to implement a smart treatment of weeds...... in agricultural fields. The purpose is to control and reduce the amount of herbicides, consumed energy and vehicle emissions in the weed detection and treatment process, thus reducing the environmental impact. The project addresses this issue through a closed loop cooperation among a team of unmanned aircraft...... system (UAS) and unmanned ground vehicles (UGV) with advanced vision sensors for 3D and multispectral imaging. This paper presents the scientific and technological challenges in the project, which include multivehicle estimation and guidance, heterogeneous multi-agent systems, task generation...

Vehicle Reference Generator for Collision-Free Trajectories in Hazardous Maneuvers

Directory of Open Access Journals (Sweden)

Cuauhtémoc Acosta Lúa

2018-01-01

Full Text Available This paper presents a reference generator for ground vehicles, based on potential fields adapted to the case of vehicular dynamics. The reference generator generates signals to be tracked by the vehicle, corresponding to a trajectory avoiding collisions with obstacles. This generator integrates artificial forces of potential fields of the object surrounding the vehicle. The reference generator is used with a controller to ensure the tracking of the accident-free reference. This approach can be used for vehicle autonomous driving or for active control of manned vehicles. Simulation results, presented for the autonomous driving, consider a scenario inspired by the so-called moose (or elk test, with the presence of other collaborative vehicles.

Evaluation of Fuel-Cell Range Extender Impact on Hybrid Electrical Vehicle Performance

DEFF Research Database (Denmark)

Jensen, Hans-Christian Becker; Schaltz, Erik; Koustrup, Per Sune

2013-01-01

The use of electric vehicles (EVs) is advantageous because of zero emission, but their market penetration is limited by one disadvantage, i.e., energy storage. Battery EVs (BEVs) have a limited range, and their batteries take a long time to charge, compared with the time it takes to refuel the tank...... of a vehicle with an internal combustion engine (ICE). Fuel cells (FCs) can be added to an EV as an additional energy source. These are faster to refill and will therefore facilitate the transition from vehicles running on fossil fuel to electricity. Different EV setups with FC strategies are presented...... in start/stop city cycles. Simulations with the New European Driving Cycle (NEDC) showed that efficiency fell by at least 15% for the FC hybrid EV (FCHEV) when compared with BEVs....

78 FR 53500 - Petition for Exemption From the Federal Motor Vehicle Theft Prevention Standard; Chrysler

Science.gov (United States)

2013-08-29

... Radio Frequency Hub Module (RFHM), Ignition Node Module (IGNM), Engine Control Module, Body Controller...) transceiver and a microprocessor and it initiates the ignition process by communicating with the BCM through... vehicles, the RFHM is connected to a Keyless Ignition Node (KIN) with a START/STOP push button as an...

Effect of gear shift and engine start losses on control strategies for hybrid electric vehicles

NARCIS (Netherlands)

Ngo, V.; Hofman, T.; Steinbuch, M.; Serrarens, A.

2012-01-01

In this paper, energetic loss models in the events of shifting gear and starting engine in a parallel Hybrid Electric Vehicle equipped with an Automated Manual Transmission (AMT) will be introduced. The optimal control algorithm for the start-stop, power split and gear shift problem based on Dynamic

How to Stop Biting Your Nails

Medline Plus

Full Text Available ... your fingers and from your nails to your face and mouth. To help you stop biting your ... re inclined to bite may help solve the problem. Try to gradually stop biting your nails: Some ...

High clearance phenotyping systems for season-long measurement of corn, sorghum and other row crops to complement unmanned aerial vehicle systems

Science.gov (United States)

Murray, Seth C.; Knox, Leighton; Hartley, Brandon; Méndez-Dorado, Mario A.; Richardson, Grant; Thomasson, J. Alex; Shi, Yeyin; Rajan, Nithya; Neely, Haly; Bagavathiannan, Muthukumar; Dong, Xuejun; Rooney, William L.

2016-05-01

The next generation of plant breeding progress requires accurately estimating plant growth and development parameters to be made over routine intervals within large field experiments. Hand measurements are laborious and time consuming and the most promising tools under development are sensors carried by ground vehicles or unmanned aerial vehicles, with each specific vehicle having unique limitations. Previously available ground vehicles have primarily been restricted to monitoring shorter crops or early growth in corn and sorghum, since plants taller than a meter could be damaged by a tractor or spray rig passing over them. Here we have designed two and already constructed one of these self-propelled ground vehicles with adjustable heights that can clear mature corn and sorghum without damage (over three meters of clearance), which will work for shorter row crops as well. In addition to regular RGB image capture, sensor suites are incorporated to estimate plant height, vegetation indices, canopy temperature and photosynthetically active solar radiation, all referenced using RTK GPS to individual plots. These ground vehicles will be useful to validate data collected from unmanned aerial vehicles and support hand measurements taken on plots.

Application of the RADTRAN 5 stop model

International Nuclear Information System (INIS)

Neuhauser, K.S.; Kanipe, R.L.; Weiner, R.F.

1997-01-01

A number of environmental impact analyses with the RADTRAN computer code have shown that dose to persons at stops is one of the largest components of incident-free dose during overland carriage of spent fuel and other radioactive materials (e.g., USDOE, 1994). The input data used in these analyses were taken from a 1983 study that reports actual observations of spent fuel shipments by truck. Early RADTRAN stop models, however, were insufficiently flexible to take advantage of the detailed information in the study. A more recent study of gasoline service stations that specialize in servicing large trucks, which are the most likely stop locations for shipments of Type B packages in the United States, has provided additional, detailed data on refueling/meal stops. The RADTRAN 5 computer code for transportation risk analysis allows exposures at stops to be more fully modeled than have previous releases of the code and is able to take advantage of detailed data. It is the intent of this paper first to compare results from RADTRAN and RADTRAN 5 for the old, low-resolution form of input data, and then to demonstrate what effect the new data and input format have on stop-dose estimates for an individual stop and for a hypothetical shipment route. Finally, these estimated public doses will be contrasted with doses calculated for a special population group -- inspectors

Application of the radtran 5 stop model

International Nuclear Information System (INIS)

Neuhauser, K.S.; Kanipe, R.L.; Weiner, R.F.

1998-01-01

A number of environmental impact analyzes with the RADTRAN computer code have shown that dose to persons at stops is one of the largest components of incident-free dose during overland carriage of spent fuel and other radioactive materials. The input data used in these analyses were taken from a 1983 study that reports actual observations of spent fuel shipments by truck. Early RADTRAN stop models, however, were insufficiently flexible to take advantage of the detailed information in the study. A more recent study of gasoline service stations that specialize in servicing large trucks, which are the most likely stop locations for shipments of Type B packages in the United States, has provided additional, detailed data on refueling/meal stops. The RADTRAN 5 computer code for transportation risk analysis allows exposures at stops to be more fully modelled than have previous releases of the code and is able to take advantage of detailed data. It is the intent of this paper first to compare results from RADTRAN 4 and RADTRAN 5 for the old, low-resolution form of input data, and then to demonstrate what effect the new data and input format have on stop-dose estimates for an individual stop and for a hypothetical shipment route. Finally, these estimated public doses will be contrasted with doses calculated for a special population group-inspectors. (authors)

Lifespan changes in global and selective stopping and performance adjustments

Directory of Open Access Journals (Sweden)

Maria Christina Van De Laar

2011-12-01

Full Text Available This study examined stopping and performance adjustments in four age groups (M ages: 8, 12, 21, and 76 years. All participants performed on three tasks, a standard two-choice task and the same task in which stop-signal trials were inserted requiring either the suppression of the response activated by the choice stimulus (global stop task or the suppression of the response when one stop signal was presented but not when the other stop signal occurred (selective stop task. The results showed that global stopping was faster than selective stopping in all age groups. Global stopping matured more rapidly than selective stopping. The developmental gain in stopping was considerably more pronounced compared to the loss observed during senescence. All age groups slowed the response on trials without a stop signal in the stop task compared to trials in the choice task, the elderly in particular. In addition, all age groups slowed on trials following stop-signal trials, except the elderly who did not slow following successful inhibits. By contrast, the slowing following failed inhibits was disproportionally larger in the elderly compared to young adults. Finally, sequential effects did not alter the pattern of performance adjustments. The results were interpreted in terms of developmental change in the balance between proactive and reactive control.

Lifespan Changes in Global and Selective Stopping and Performance Adjustments

Science.gov (United States)

van de Laar, Maria C.; van den Wildenberg, Wery P. M.; van Boxtel, Geert J. M.; van der Molen, Maurits W.

2011-01-01

This study examined stopping and performance adjustments in four age groups (M ages: 8, 12, 21, and 76 years). All participants performed on three tasks, a standard two-choice task and the same task in which stop-signal trials were inserted requiring either the suppression of the response activated by the choice stimulus (global stop task) or the suppression of the response when one stop-signal was presented but not when the other stop-signal occurred (selective stop task). The results showed that global stopping was faster than selective stopping in all age groups. Global stopping matured more rapidly than selective stopping. The developmental gain in stopping was considerably more pronounced compared to the loss observed during senescence. All age groups slowed the response on trials without a stop-signal in the stop task compared to trials in the choice task, the elderly in particular. In addition, all age groups slowed on trials following stop-signal trials, except the elderly who did not slow following successful inhibits. By contrast, the slowing following failed inhibits was disproportionally larger in the elderly compared to young adults. Finally, sequential effects did not alter the pattern of performance adjustments. The results were interpreted in terms of developmental change in the balance between proactive and reactive control. PMID:22180746

Combined emergency braking and turning of articulated heavy vehicles

OpenAIRE

Morrison, G; Cebon, David

2017-01-01

‘Slip control’ braking has been shown to reduce the emergency stopping distance of an experimental heavy goods vehicle by up to 19%, compared to conventional electronic/anti-lock braking systems (EBS). However, little regard has been given to the impact of slip control braking on the vehicle’s directional dynamics. This paper uses validated computer models to show that slip control could severely degrade directional performance during emergency braking. A modified slip control strategy, ‘atte...

Note on measuring electronic stopping of slow ions

Science.gov (United States)

Sigmund, P.; Schinner, A.

2017-11-01

Extracting stopping cross sections from energy-loss measurements requires careful consideration of the experimental geometry. Standard procedures for separating nuclear from electronic stopping treat electronic energy loss as a friction force, ignoring its dependence on impact parameter. In the present study we find that incorporating this dependence has a major effect on measured stopping cross sections, in particular for light ions at low beam energies. Calculations have been made for transmission geometry, nuclear interactions being quantified by Bohr-Williams theory of multiple scattering on the basis of a Thomas-Fermi-Molière potential, whereas electronic interactions are characterized by Firsov theory or PASS code. Differences between the full and the restricted stopping cross section depend on target thickness and opening angle of the detector and need to be taken into account in comparisons with theory as well as in applications of stopping data. It follows that the reciprocity principle can be violated when checked on restricted instead of full electronic stopping cross sections. Finally, we assert that a seeming gas-solid difference in stopping of low-energy ions is actually a metal-insulator difference. In comparisons with experimental results we mostly consider proton data, where nuclear stopping is only a minor perturbation.

Developing Autonomous Vehicles That Learn to Navigate by Mimicking Human Behavior

Science.gov (United States)

2006-09-28

navigate in an unstructured environment to a specific target or location. 15. SUBJECT TERMS autonomous vehicles , fuzzy logic, learning behavior...ANSI-Std Z39-18 Developing Autonomous Vehicles That Learn to Navigate by Mimicking Human Behavior FINAL REPORT 9/28/2006 Dean B. Edwards Department...the future, as greater numbers of autonomous vehicles are employed, it is hoped that lower LONG-TERM GOALS Use LAGR (Learning Applied to Ground Robots

Stop searches in flavourful supersymmetry

CERN Document Server

Crivellin, Andreas; Tunstall, Lewis C.

2016-01-01

Natural realisations of supersymmetry require light stops ${\\tilde t}_1$, making them a prime target of LHC searches for physics beyond the Standard Model. Depending on the kinematic region, the main search channels are ${\\tilde t_1}\\to t \\tilde \\chi^0_1$, ${\\tilde t_1}\\to W b \\tilde \\chi^0_1$ and ${\\tilde t_1}\\to c \\tilde \\chi^0_1$. We first examine the interplay of these decay modes with ${\\tilde c_1}\\to c \\tilde \\chi^0_1$ in a model-independent fashion, revealing the existence of large regions in parameter space which are excluded for any ${\\tilde t_1}\\to c \\tilde \\chi^0_1$ branching ratio. This effect is then illustrated for scenarios with stop-scharm mixing in the right-handed sector, where it has previously been observed that the stop mass limits can be significantly weakened for large mixing. Our analysis shows that once the LHC bounds from ${\\tilde c_1}\\to c \\tilde \\chi^0_1$ searches are taken into account, non-zero stop-scharm mixing leads only to a modest increase in the allowed regions of parameter...

Stopping power for heavy ions in low energy region

International Nuclear Information System (INIS)

Kitagawa, Mitsuo

1983-01-01

Review is made for the study on the power for stopping heavy ions. The studies on the power for stopping heavy ions passing through materials have been developed in the last twenty years due to the accuracy improvement in the data analysis of the power for stopping light ions, the requirement of data establishment on the power for stopping heavy ions from fusion research and the development of the experimental studies by heavy-ion accelerators. The relation between the analysis of the power for stopping heavy ions and the power for stopping light ions is described from the standpoint that the results on the power for stopping light ions serve as the guide for the study on the power for stopping heavy ions. Both at present and in future. The analysis of stopping power data with the accuracy from +-10 to 20 % is possible from the theoretical analysis of effective electric charge and its systematic table of the numerical data. The outline of the scaling rule on effective electric charge is discussed. The deviation of the experimental data from the scaling rule is discussed by comparing with the measured values of effective electric charge ratio. Various analyses of the power for stopping heavy ions are summarized. (Asami, T.)

Sweet Spots and Door Stops

Science.gov (United States)

Thompson, Michael; Tsui, Stella; Leung, Chi Fan

2011-01-01

A sweet spot is referred to in sport as the perfect place to strike a ball with a racquet or bat. It is the point of contact between bat and ball where maximum results can be produced with minimal effort from the hand of the player. Similar physics can be applied to the less inspiring examples of door stops; the perfect position of a door stop is…

Ground Vehicle System Integration (GVSI) and Design Optimization Model.

Science.gov (United States)

1996-07-30

number of stowed kills Same basic load lasts longer range Gun/ammo parameters impact system weight, under - armor volume requirements Round volume...internal volume is reduced, the model assumes that the crew’s ability to operate while under armor will be impaired. If the size of a vehicle crew is...changing swept volume will alter under armor volume requirements for the total system; if system volume is fixed, changing swept volume will

Intelligent Bus Stops in the Flexible Bus Systems

OpenAIRE

Razi Iqbal; Muhammad Usman Ghani

2014-01-01

The purpose of this paper is to discuss Intelligent Bus Stops in a special Demand Responsive Transit (DRT), the Flexible Bus System. These Intelligent Bus Stops are more efficient and information rich than Traditional Bus Stops. The real time synchronization of the Flexible Bus System makes it unique as compared to Traditional Bus Systems. The Main concern is to make Bus Stops intelligent and information rich. Buses are informed about the no. of passengers waiting at the upcoming ...

Ground System Survivability Overview

Science.gov (United States)

2012-03-27

Avoidance Blast Mitigation Optimization Customer ILIR RDT&E Funding 5.0 % 0.5% GSS has a proven, technically proficient workforce that meets...Evaluation of Defensive-Aid Suites (ARMED) Common Automatic Fire Extinguishing System ( CAFES ) Transparent Armor Development Ground Combat Vehicle...Survey TRADOC (WFO, CNA, etc) Voice of the Customer Sy st em s En gi ne er in g Publish overarching MIL-STD, design guidelines, technical

Autonomous urban reconnaissance ingress system (AURIS): providing a tactically relevant autonomous door-opening kit for unmanned ground vehicles

Science.gov (United States)

Shane, David J.; Rufo, Michael A.; Berkemeier, Matthew D.; Alberts, Joel A.

2012-06-01

The Autonomous Urban Reconnaissance Ingress System (AURIS™) addresses a significant limitation of current military and first responder robotics technology: the inability of reconnaissance robots to open doors. Leveraging user testing as a baseline, the program has derived specifications necessary for military personnel to open doors with fielded UGVs (Unmanned Ground Vehicles), and evaluates the technology's impact on operational mission areas: duration, timing, and user patience in developing a tactically relevant, safe, and effective system. Funding is provided through the US ARMY Tank Automotive Research, Development and Engineering Center (TARDEC) and the project represents a leap forward in perception, autonomy, robotic implements, and coordinated payload operation in UGVs. This paper describes high level details of specification generation, status of the last phase of development, an advanced view of the system autonomy capability, and a short look ahead towards the ongoing work on this compelling and important technology.

Inertial-confinement-fusion applications of ion-stopping theory

International Nuclear Information System (INIS)

More, R.M.; Lee, Y.T.; Bailey, D.S.

1982-01-01

Methods were developed to calculate: (1) the stopping power of a hot plasma target, (2) the charge-state of a fast ion projectile, and (3) the final disposition of the deposited energy. The first issue refers to the stopping power for protons. The proton stopping power is altered in high-density or high-temperature targets, especially at velocities below the stopping peak. The second issue concerns the application of a proton stopping curve to the arbitrary projectile. The third topic is more specialized to inertial fusion and concerns the partition of deposited energy between ion (nuclear motion) degrees of freedom and those corresponding to bound and free electrons. The question here is whether a thermal equilibrium plasma is produced

The Stop Transmission of Polio Data Management (STOP DM) assignment and its role in polio eradication and immunization data improvement in Africa.

Science.gov (United States)

Benke, Amalia; Williams, Alford Joseph; MacNeil, Adam

2017-01-01

The availability and use of high quality immunization and surveillance data are crucial for monitoring all components of the Global Polio Eradication Program (GPEI). The Stop Transmission of Polio (STOP) program was initiated in 1999 to train and mobilize human resources to provide technical support to polio endemic and at-risk countries and in 2002 the STOP data management (STOP DM) deployment was created to provide capacity development in the area of data management for immunization and surveillance data for these countries. Since 2002, Africa has received the majority of support from the STOP DM program, with almost 80% of assignments being placed in African countries. The STOP DM program has played a valuable role in improving the quality and use of data for the GPEI and has increasingly supported other immunization program data needs. In this report we provide an overview of the history, current status, and future of the STOP DM program, with a specific focus on the African continent.

Routing the asteroid surface vehicle with detailed mechanics

Science.gov (United States)

Yu, Yang; Baoyin, He-Xi

2014-06-01

The motion of a surface vehicle on/above an irregular object is investigated for a potential interest in the insitu explorations to asteroids of the solar system. A global valid numeric method, including detailed gravity and geomorphology, is developed to mimic the behaviors of the test particles governed by the orbital equations and surface coupling effects. A general discussion on the surface mechanical environment of a specified asteroid, 1620 Geographos, is presented to make a global evaluation of the surface vehicle's working conditions. We show the connections between the natural trajectories near the ground and differential features of the asteroid surface, which describes both the good and bad of typical terrains from the viewpoint of vehicles' dynamic performances. Monte Carlo simulations are performed to take a further look at the trajectories of particles initializing near the surface. The simulations reveal consistent conclusions with the analysis, i.e., the open-field flat ground and slightly concave basins/valleys are the best choices for the vehicles' dynamical security. The dependence of decending trajectories on the releasing height is studied as an application; the results show that the pole direction (where the centrifugal force is zero) is the most stable direction in which the shift of a natural trajectory will be well limited after landing. We present this work as an example for pre-analysis that provides guidance to engineering design of the exploration site and routing the surface vehicles.

Developing a Blended Type Course of Introduction to Hybrid Vehicles

Directory of Open Access Journals (Sweden)

Na Zhu

2016-02-01

Full Text Available An innovative course of introduction to hybrid vehicles is developed for both associate and bachelor degree programs for engineering technology with automotive/mechanical concentration. The hybrid vehicle course content includes several topics, such as the rational of pure electric vehicle and hybrid vehicle, hybrid vehicle propulsion systems, fundamentals of motor/generator systems, fundamentals of battery and energy management system, and introduction to various configurations of hybrid vehicle systems available in market and under development. Hybrid vehicle technology is a new area and developed rapidly in the field of automotive and mechanical engineering. Students need not only the fundamentals and concepts from college, but also the ability to keep up with the latest technology after their graduation. Therefore, a blended course type is employed to help students have a better understanding of the fundamentals of hybrid vehicle and developing their self-studying ability. Topics in the course have three steps of learning. Firstly, on-ground lecture is given in class, where the instructor explains basic knowledge, such as principles, equations, and design rules.  In this way, the students will have enough background knowledge and be able to conduct further self-reading and research work. Secondly, students are required to go to university’s desire to learn (D2L online system and finish the online part of the topic. In the D2L system, students will find a quiz and its supporting materials. Thirdly, students come back to the on-ground lecture and discuss the quiz in groups with instructor. After the discussion, the instructor gives students a conclusion of the topic and moves forward to the next topic. A computer simulation class is also given to help student better understand the operation strategies of the hybrid vehicle systems and have a trial of design of hybrid vehicle.

Contamination and decontamination of vehicles when driven in radioactive areas

International Nuclear Information System (INIS)

Ulvsand, T.; Nygren, U.

1999-10-01

There is reason to ask whether it is beneficial to decontaminate vehicles, in view of the great effort applied. If the level of contamination is low before the decontamination process, then the cost is not motivated, even if the decontamination is shown to be effective in relative terms. The report describes two trials at the National NBC Defence School in Umeaa and one trial at the French test site in Bourges. The aim is to investigate how vehicles are contaminated and at which ground deposition levels troublesome levels of contamination will arise. In the trials, a non-radioactive agent substituting real radioactivity was used. The trials in Sweden so far have used the oversnow vehicle BV 206, during both winter and summer conditions. The vehicles were driven a specific distance along a road on which a known amount of the test substance had been dispersed. Samples were taken on pre-determined areas on one side of the vehicles to measure the amount of test substance. Later, the vehicles continued along a 'clean' road where additional samples were taken, but on the other side of the vehicles. The largest amount of test substance was collected on the tracks and on the back of the vehicle. The tracks and mud-flaps were effectively decontaminated when the vehicles were driven along a clean road, while most of the contamination remained on the backside. The purpose of the trials in France was to compare the results from our non-radioactive and their radioactive method, based on the radioactive La-140. Due to ground conditions, the level of contamination on the vehicles was much less than in the trials in Umeaa, but the effect decontamination could be measured after all

Empirical stopping powers for ions in solids

International Nuclear Information System (INIS)

Ziegler, J.F.; Biersack, J.P.; Littmark, U.

1983-01-01

The work of Brandt and collaborators on low energy ion stopping powers has been extended to create an empirical formulation for the stopping of ions in solids. The result is a simple computer program (about 60 lines of code) which calculates stopping powers from zero to 100 MeV/amu for all ions in all elemental solids. This code has been compared to the data in about 2000 papers, and has a standard error of 9% for energies above keV/amu. This approach includes high energy relativistic effects and shell-corrections. In the medium energy range it uses stopping theory based on the local-density approximation and Lindhard stopping in a free electron gas. This is applied to realistic Hartree-Fock charge distributions for crystalline solids. In the low energy range it uses the Brandt concepts of ion stripping relative to the Fermi velocity of solids, and also his formalism for the relation of projectile ionization to its effective charge. The details of the calculation are presented, and a broad comparison is shown with experiment. Special comparative examples are shown of both the low energy stopping power oscillations which depend on the atomic number of the ion, and also of the target

Hybrid Turbine Electric Vehicle

Science.gov (United States)

Viterna, Larry A.

1997-01-01

Hybrid electric power trains may revolutionize today's ground passenger vehicles by significantly improving fuel economy and decreasing emissions. The NASA Lewis Research Center is working with industry, universities, and Government to develop and demonstrate a hybrid electric vehicle. Our partners include Bowling Green State University, the Cleveland Regional Transit Authority, Lincoln Electric Motor Division, the State of Ohio's Department of Development, and Teledyne Ryan Aeronautical. The vehicle will be a heavy class urban transit bus offering double the fuel economy of today's buses and emissions that are reduced to 1/10th of the Environmental Protection Agency's standards. At the heart of the vehicle's drive train is a natural-gas-fueled engine. Initially, a small automotive engine will be tested as a baseline. This will be followed by the introduction of an advanced gas turbine developed from an aircraft jet engine. The engine turns a high-speed generator, producing electricity. Power from both the generator and an onboard energy storage system is then provided to a variable-speed electric motor attached to the rear drive axle. An intelligent power-control system determines the most efficient operation of the engine and energy storage system.

Modeling driver stop/run behavior at the onset of a yellow indication considering driver run tendency and roadway surface conditions.

Science.gov (United States)

Elhenawy, Mohammed; Jahangiri, Arash; Rakha, Hesham A; El-Shawarby, Ihab

2015-10-01

The ability to model driver stop/run behavior at signalized intersections considering the roadway surface condition is critical in the design of advanced driver assistance systems. Such systems can reduce intersection crashes and fatalities by predicting driver stop/run behavior. The research presented in this paper uses data collected from two controlled field experiments on the Smart Road at the Virginia Tech Transportation Institute (VTTI) to model driver stop/run behavior at the onset of a yellow indication for different roadway surface conditions. The paper offers two contributions. First, it introduces a new predictor related to driver aggressiveness and demonstrates that this measure enhances the modeling of driver stop/run behavior. Second, it applies well-known artificial intelligence techniques including: adaptive boosting (AdaBoost), random forest, and support vector machine (SVM) algorithms as well as traditional logistic regression techniques on the data in order to develop a model that can be used by traffic signal controllers to predict driver stop/run decisions in a connected vehicle environment. The research demonstrates that by adding the proposed driver aggressiveness predictor to the model, there is a statistically significant increase in the model accuracy. Moreover the false alarm rate is significantly reduced but this reduction is not statistically significant. The study demonstrates that, for the subject data, the SVM machine learning algorithm performs the best in terms of optimum classification accuracy and false positive rates. However, the SVM model produces the best performance in terms of the classification accuracy only. Copyright © 2015 Elsevier Ltd. All rights reserved.

Operations Assessment of Launch Vehicle Architectures using Activity Based Cost Models

Science.gov (United States)

Ruiz-Torres, Alex J.; McCleskey, Carey

2000-01-01

The growing emphasis on affordability for space transportation systems requires the assessment of new space vehicles for all life cycle activities, from design and development, through manufacturing and operations. This paper addresses the operational assessment of launch vehicles, focusing on modeling the ground support requirements of a vehicle architecture, and estimating the resulting costs and flight rate. This paper proposes the use of Activity Based Costing (ABC) modeling for this assessment. The model uses expert knowledge to determine the activities, the activity times and the activity costs based on vehicle design characteristics. The approach provides several advantages to current approaches to vehicle architecture assessment including easier validation and allowing vehicle designers to understand the cost and cycle time drivers.

Nuclear stopping in transmission experiments

International Nuclear Information System (INIS)

Glazov, Lev G.; Sigmund, Peter

2003-01-01

Energy-loss spectra, mean and peak energy loss, and straggling due to elastic nuclear scattering have been studied theoretically as a function of target thickness and deflection angle of an initially monochromatic and well-collimated ion beam. The goal of this work has been to provide a generally valid scheme for nuclear-stopping corrections, allowing to determine electronic-stopping forces from energy-loss spectra measured in transmission geometry. Calculations have been based on the generalized Bothe-Landau theory of energy loss and multiple scattering. Our peak energy losses at zero emergence angle show close (∼10%) agreement with predictions of Fastrup et al. on the basis of the Bohr-Williams theory. However, predicted mean and peak energy losses are found to more sensitively depend on the underlying interatomic potential than unrestricted, i.e. angle-integrated mean or peak energy losses. Both elastic energy loss and multiple scattering are known to obey scaling laws involving only two combinations of the pertinent variables and atomic parameters. The dependence on deflection angle and foil thickness of mean and peak energy loss obeys a simple combination of these scaling laws. Comments are made on potential errors due to uncertainties in the nuclear-stopping correction applied in the literature with specific reference to central papers in low-velocity stopping

Correlated ion stopping in plasmas

International Nuclear Information System (INIS)

Zwicknagel, G.; Deutsch, C.

1997-01-01

The basic features of correlated ion stopping in plasmas are demonstrated by employing two opposite extremes of cluster structures, a statistical model with a spatial ion distribution of Gaussian shape and the highly regular configuration of N-ion chains and cubic boxes. In the case of the ion chains the resonant character of correlated stopping due to the interference of the excited wake fields is discussed in detail. The general behavior of correlation effects is summarized and its dependence on the ratio of cluster size and interion spacing to the screening length in the plasma, as well as the ratio of the cluster velocity to the mean electron velocity in the target, is stressed out. The validity and applicability of the dielectric response formalism used for describing correlated stopping is critically reviewed. A scheme is presented to extend the linear formalism to weak nonlinear situations that occur, in particular, for small highly charged clusters at moderate or low velocities. For the Gaussian cluster a fit formula is given, which allows a fast and accurate calculation of the enhancement of stopping due to correlation effects and applies for all degrees of degeneracy of the electrons and arbitrary cluster velocities. copyright 1997 The American Physical Society

2011 Ground Testing Highlights Article

Science.gov (United States)

Ross, James C.; Buchholz, Steven J.

2011-01-01

Two tests supporting development of the launch abort system for the Orion MultiPurpose Crew Vehicle were run in the NASA Ames Unitary Plan wind tunnel last year. The first test used a fully metric model to examine the stability and controllability of the Launch Abort Vehicle during potential abort scenarios for Mach numbers ranging from 0.3 to 2.5. The aerodynamic effects of the Abort Motor and Attitude Control Motor plumes were simulated using high-pressure air flowing through independent paths. The aerodynamic effects of the proximity to the launch vehicle during the early moments of an abort were simulated with a remotely actuated Service Module that allowed the position relative to the Crew Module to be varied appropriately. The second test simulated the acoustic environment around the Launch Abort Vehicle caused by the plumes from the 400,000-pound thrust, solid-fueled Abort Motor. To obtain the proper acoustic characteristics of the hot rocket plumes for the flight vehicle, heated Helium was used. A custom Helium supply system was developed for the test consisting of 2 jumbo high-pressure Helium trailers, a twelve-tube accumulator, and a 13MW gas-fired heater borrowed from the Propulsion Simulation Laboratory at NASA Glenn Research Center. The test provided fluctuating surface pressure measurements at over 200 points on the vehicle surface that have now been used to define the ground-testing requirements for the Orion Launch Abort Vehicle.

Reducing passengers’ travel time by optimising stopping patterns in a large-scale network: A case-study in the Copenhagen Region

DEFF Research Database (Denmark)

Parbo, Jens; Nielsen, Otto Anker; Prato, Carlo Giacomo

2018-01-01

Optimising stopping patterns in railway schedules is a cost-effective way to reduce passengers’ generalised travel costs without increasing train operators’ costs. The challenge consists in striking a balance between an increase in waiting time for passengers at skipped stations and a decrease...... in travel time for through-going passengers, with possible consequent changes in the passenger demand and route choices. This study presents the formulation of the skip-stop problem as a bi-level optimisation problem where the lower level is a schedule-based transit assignment model that delivers passengers...... is a mixed-integer problem, whereas the route choice model is a non-linear non-continuous mapping of the timetable. The method was tested on the suburban railway network in the Greater Copenhagen Region (Denmark): the reduction in railway passengers’ in-vehicle travel time was 5.5%, the reduction...

Study of high-definition and stereoscopic head-aimed vision for improved teleoperation of an unmanned ground vehicle

Science.gov (United States)

Tyczka, Dale R.; Wright, Robert; Janiszewski, Brian; Chatten, Martha Jane; Bowen, Thomas A.; Skibba, Brian

2012-06-01

Nearly all explosive ordnance disposal robots in use today employ monoscopic standard-definition video cameras to relay live imagery from the robot to the operator. With this approach, operators must rely on shadows and other monoscopic depth cues in order to judge distances and object depths. Alternatively, they can contact an object with the robot's manipulator to determine its position, but that approach carries with it the risk of detonation from unintentionally disturbing the target or nearby objects. We recently completed a study in which high-definition (HD) and stereoscopic video cameras were used in addition to conventional standard-definition (SD) cameras in order to determine if higher resolutions and/or stereoscopic depth cues improve operators' overall performance of various unmanned ground vehicle (UGV) tasks. We also studied the effect that the different vision modes had on operator comfort. A total of six different head-aimed vision modes were used including normal-separation HD stereo, SD stereo, "micro" (reduced separation) SD stereo, HD mono, and SD mono (two types). In general, the study results support the expectation that higher resolution and stereoscopic vision aid UGV teleoperation, but the degree of improvement was found to depend on the specific task being performed; certain tasks derived notably more benefit from improved depth perception than others. This effort was sponsored by the Joint Ground Robotics Enterprise under Robotics Technology Consortium Agreement #69-200902 T01. Technical management was provided by the U.S. Air Force Research Laboratory's Robotics Research and Development Group at Tyndall AFB, Florida.

Assessment of future natural gas vehicle concepts

Science.gov (United States)

Groten, B.; Arrigotti, S.

1992-10-01

The development of Natural Gas Vehicles is progressing rapidly under the stimulus of recent vehicle emission regulations. The development is following what can be viewed as a three step progression. In the first step, contemporary gasoline or diesel fueled automobiles are retrofitted with equipment enabling the vehicle to operate on either natural gas or standard liquid fuels. The second step is the development of vehicles which utilize traditional internal combustion engines that have been modified to operate exclusively on natural gas. These dedicated natural gas vehicles operate more efficiently and have lower emissions than the dual fueled vehicles. The third step is the redesigning, from the ground up, of a vehicle aimed at exploiting the advantages of natural gas as an automotive fuel while minimizing its disadvantages. The current report is aimed at identifying the R&D needs in various fuel storage and engine combinations which have potential for providing increased efficiency, reduced emissions, and reductions in vehicle weight and size. Fuel suppliers, automobile and engine manufacturers, many segments of the natural gas and other industries, and regulatory authorities will influence or be affected by the development of such a third generation vehicle, and it is recommended that GRI act to bring these groups together in the near future to begin, developing the focus on a 'designed-for-natural-gas' vehicle.

Stop Negative Thinking Effects for Drug Dependence

OpenAIRE

Windiarti, Sri Endang; Indriati, Indriati; Surachmi, Fajar

2013-01-01

The purpose of this study was to determine the effect of therapy stop thinking negatively against drug addiction in Rehabilitation Orphanage Rumah Damai Gunung Pati Semarang. This research is quasy experiment with pretest - posttes without the control group design. Thirty respondents were taken to the reseach sujects. Stop thinking negative therapy before and after thebehavior of drug addiction there are differences (t = 0.00), so it can be stated that the therapy stop thinking negatively inf...

Vehicle state estimation using GPS/IMU integration

NARCIS (Netherlands)

Wang, Y.; Mangnus, J.; Kostić, D.; Nijmeijer, H.; Jansen, S.T.H.

2011-01-01

New driver support systems require knowledge of the vehicle position with great accuracy and reliability. Satellite navigation (GNSS) is generally insufficiently accurate for positioning and as an alternative to using a ground station, combinations with high quality motion sensors are used in

"Stop Diabetes Now!"

Science.gov (United States)

... of this page please turn Javascript on. Feature: Diabetes "Stop Diabetes Now!" Past Issues / Fall 2009 Table of Contents ... Tips for Seniors at Risk for Type 2 Diabetes Lifestyle changes that lead to weight loss—such ...

Analysis of Non-Tactical Vehicle Utilization at Fort Carson Colorado

Science.gov (United States)

2012-01-01

regenerative braking energy recovery. The mass of the vehicles monitored in this study was not known. However, some useful information may be...Unclassified: Distribution A. Approved for Public Release 2012 NDIA GROUND VEHICLE SYSTEMS ENGINEERING AND TECHNOLOGY SYMPOSIUM MODELING... regenerative energy recovery potential for specific duty cycles was also quantified through a cumulative assessment of the number and severity of deceleration

Suborbital Reusable Launch Vehicles as an Opportunity to Consolidate and Calibrate Ground Based and Satellite Instruments

Science.gov (United States)

Papadopoulos, K.

2014-12-01

XCOR Aerospace, a commercial space company, is planning to provide frequent, low cost access to near-Earth space on the Lynx suborbital Reusable Launch Vehicle (sRLV). Measurements in the external vacuum environment can be made and can launch from most runways on a limited lead time. Lynx can operate as a platform to perform suborbital in situ measurements and remote sensing to supplement models and simulations with new data points. These measurements can serve as a quantitative link to existing instruments and be used as a basis to calibrate detectors on spacecraft. Easier access to suborbital data can improve the longevity and cohesiveness of spacecraft and ground-based resources. A study of how these measurements can be made on Lynx sRLV will be presented. At the boundary between terrestrial and space weather, measurements from instruments on Lynx can help develop algorithms to optimize the consolidation of ground and satellite based data as well as assimilate global models with new data points. For example, current tides and the equatorial electrojet, essential to understanding the Thermosphere-Ionosphere system, can be measured in situ frequently and on short notice. Furthermore, a negative-ion spectrometer and a Faraday cup, can take measurements of the D-region ion composition. A differential GPS receiver can infer the spatial gradient of ionospheric electron density. Instruments and optics on spacecraft degrade over time, leading to calibration drift. Lynx can be a cost effective platform for deploying a reference instrument to calibrate satellites with a frequent and fast turnaround and a successful return of the instrument. A calibrated reference instrument on Lynx can make collocated observations as another instrument and corrections are made for the latter, thus ensuring data consistency and mission longevity. Aboard a sRLV, atmospheric conditions that distort remotely sensed data (ground and spacecraft based) can be measured in situ. Moreover, an

Vegetation Versus Man-Made Object Detection from Imagery for Unmanned Vehicles in Off-Road Environments

Science.gov (United States)

2013-05-01

saliency, natural scene statistics 1. INTRODUCTION Research into the area of autonomous navigation for unmanned ground vehicles (UGV) has accelerated in...recent years. This is partly due to the success of programs such as the DARPA Grand Challenge1 and the dream of driverless cars ,2 but is also due to the...NOTES 14. ABSTRACT There have been several major advances in autonomous navigation for unmanned ground vehicles in controlled urban environments in

Sustainable ground transportation – review of technologies, challenges and opportunities

Energy Technology Data Exchange (ETDEWEB)

Agarwal, Ramesh K. [Department of Mechanical Engineering and Materials Science, Washington University, St. Louis, MO 63130 (United States)

2013-07-01

Currently there are nearly 750 million ground vehicles in service worldwide. They are responsible for 50% of petroleum (oil) consumption and 60% of all greenhouse gas (GHG) emissions worldwide. The number of vehicles is forecasted to double by 2050. Therefore the environmental issues such as noise, emissions and fuel burn have become important for energy and environmental sustainability. This paper provides an overview of specific energy and environmental issues related to ground transportation. The technologies related to reduction in energy requirements such as reducing the vehicle mass by using the high strength low weight materials and reducing the viscous drag by active flow control and smoothing the operational profile, and reducing the contact friction by special tire materials are discussed along with the portable energy sources for reducing the GHG emissions such as low carbon fuels (biofuels), Lithium-ion batteries with high energy density and stability, and fuel cells. The technological challenges and opportunities for innovations are discussed.

Reliability analysis of high-speed tracked vehicles in the polish army

Directory of Open Access Journals (Sweden)

Kończak Jarosław

2017-06-01

Full Text Available The Polish Armed Forces use tracked vehicles that serve as a core element of the ground combat forces. These vehicles are capable of fighting in all kinds of terrain conditions, in any season of the year. Combat missions are often fought in areas where even no dirt roads are available. The present paper assesses the reliability of tracked vehicles in the context of their irregular operation, as well as service- and maintenance-related vulnerability.

Multi-arm group sequential designs with a simultaneous stopping rule.

Science.gov (United States)

Urach, S; Posch, M

2016-12-30

Multi-arm group sequential clinical trials are efficient designs to compare multiple treatments to a control. They allow one to test for treatment effects already in interim analyses and can have a lower average sample number than fixed sample designs. Their operating characteristics depend on the stopping rule: We consider simultaneous stopping, where the whole trial is stopped as soon as for any of the arms the null hypothesis of no treatment effect can be rejected, and separate stopping, where only recruitment to arms for which a significant treatment effect could be demonstrated is stopped, but the other arms are continued. For both stopping rules, the family-wise error rate can be controlled by the closed testing procedure applied to group sequential tests of intersection and elementary hypotheses. The group sequential boundaries for the separate stopping rule also control the family-wise error rate if the simultaneous stopping rule is applied. However, we show that for the simultaneous stopping rule, one can apply improved, less conservative stopping boundaries for local tests of elementary hypotheses. We derive corresponding improved Pocock and O'Brien type boundaries as well as optimized boundaries to maximize the power or average sample number and investigate the operating characteristics and small sample properties of the resulting designs. To control the power to reject at least one null hypothesis, the simultaneous stopping rule requires a lower average sample number than the separate stopping rule. This comes at the cost of a lower power to reject all null hypotheses. Some of this loss in power can be regained by applying the improved stopping boundaries for the simultaneous stopping rule. The procedures are illustrated with clinical trials in systemic sclerosis and narcolepsy. © 2016 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd. © 2016 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd.

Are Stopped Strings Preferred in Sad Music?

OpenAIRE

David Huron; Caitlyn Trevor

2017-01-01

String instruments may be played either with open strings (where the string vibrates between the bridge and a hard wooden nut) or with stopped strings (where the string vibrates between the bridge and a performer's finger pressed against the fingerboard). Compared with open strings, stopped strings permit the use of vibrato and exhibit a darker timbre. Inspired by research on the timbre of sad speech, we test whether there is a tendency to use stopped strings in nominally sad music. Specifica...

A MARKED POINT PROCESS MODEL FOR VEHICLE DETECTION IN AERIAL LIDAR POINT CLOUDS

Directory of Open Access Journals (Sweden)

A. Börcs

2012-07-01

Full Text Available In this paper we present an automated method for vehicle detection in LiDAR point clouds of crowded urban areas collected from an aerial platform. We assume that the input cloud is unordered, but it contains additional intensity and return number information which are jointly exploited by the proposed solution. Firstly, the 3-D point set is segmented into ground, vehicle, building roof, vegetation and clutter classes. Then the points with the corresponding class labels and intensity values are projected to the ground plane, where the optimal vehicle configuration is described by a Marked Point Process (MPP model of 2-D rectangles. Finally, the Multiple Birth and Death algorithm is utilized to find the configuration with the highest confidence.

Development and Evaluation of an Economic-Driving Assistance Program for Transit Vehicles

Directory of Open Access Journals (Sweden)

Baoxin Han

2012-02-01

Full Text Available This paper focuses on development and evaluation of an economic-driving assistance program for transit vehicles (EDTV which can minimize energy consumption, air pollution emission of buses, and improve the level of service of transit system as well. Taking advantage of the latest advances in information and communication technologies, the EDTV system can provide bus drivers with optimal recommended bus holding times at near-side bus stops and dynamic bus speed to adapt to the real-time traffic control plan at downstream intersections. In order to address the impacts of the stochastic variation of bus dwell time, the total link between adjacent intersections is divided into three parts: upstream of bus stop part; bus stop part; and downstream of bus stop part. The methods for calculating recommended parameters, including bus holding time and bus speed in each of the three parts are proposed based on real-time bus status and signal status at downstream intersections. A VISSIM-based simulation platform was designed and used for simulating and evaluating the proposed EDTV system. Extensive experimental analyses have shown that the proposed EDTV system can improve the performance of a transit system in terms of reducing fuel consumption, air pollution emissions and level of service of the transit system.

The Stop Transmission of Polio Data Management (STOP DM) assignment and its role in polio eradication and immunization data improvement in Africa

OpenAIRE

Benke, Amalia; Williams, Alford Joseph; MacNeil, Adam

2017-01-01

The availability and use of high quality immunization and surveillance data are crucial for monitoring all components of the Global Polio Eradication Program (GPEI). The Stop Transmission of Polio (STOP) program was initiated in 1999 to train and mobilize human resources to provide technical support to polio endemic and at-risk countries and in 2002 the STOP data management (STOP DM) deployment was created to provide capacity development in the area of data management for immunization and sur...

Aircraft operability methods applied to space launch vehicles

Science.gov (United States)

Young, Douglas

1997-01-01

The commercial space launch market requirement for low vehicle operations costs necessitates the application of methods and technologies developed and proven for complex aircraft systems. The ``building in'' of reliability and maintainability, which is applied extensively in the aircraft industry, has yet to be applied to the maximum extent possible on launch vehicles. Use of vehicle system and structural health monitoring, automated ground systems and diagnostic design methods derived from aircraft applications support the goal of achieving low cost launch vehicle operations. Transforming these operability techniques to space applications where diagnostic effectiveness has significantly different metrics is critical to the success of future launch systems. These concepts will be discussed with reference to broad launch vehicle applicability. Lessons learned and techniques used in the adaptation of these methods will be outlined drawing from recent aircraft programs and implementation on phase 1 of the X-33/RLV technology development program.

Ares I-X Ground Diagnostic Prototype

Science.gov (United States)

Schwabacher, Mark A.; Martin, Rodney Alexander; Waterman, Robert D.; Oostdyk, Rebecca Lynn; Ossenfort, John P.; Matthews, Bryan

2010-01-01

The automation of pre-launch diagnostics for launch vehicles offers three potential benefits: improving safety, reducing cost, and reducing launch delays. The Ares I-X Ground Diagnostic Prototype demonstrated anomaly detection, fault detection, fault isolation, and diagnostics for the Ares I-X first-stage Thrust Vector Control and for the associated ground hydraulics while the vehicle was in the Vehicle Assembly Building at Kennedy Space Center (KSC) and while it was on the launch pad. The prototype combines three existing tools. The first tool, TEAMS (Testability Engineering and Maintenance System), is a model-based tool from Qualtech Systems Inc. for fault isolation and diagnostics. The second tool, SHINE (Spacecraft Health Inference Engine), is a rule-based expert system that was developed at the NASA Jet Propulsion Laboratory. We developed SHINE rules for fault detection and mode identification, and used the outputs of SHINE as inputs to TEAMS. The third tool, IMS (Inductive Monitoring System), is an anomaly detection tool that was developed at NASA Ames Research Center. The three tools were integrated and deployed to KSC, where they were interfaced with live data. This paper describes how the prototype performed during the period of time before the launch, including accuracy and computer resource usage. The paper concludes with some of the lessons that we learned from the experience of developing and deploying the prototype.

GPS/DR Error Estimation for Autonomous Vehicle Localization.

Science.gov (United States)

Lee, Byung-Hyun; Song, Jong-Hwa; Im, Jun-Hyuck; Im, Sung-Hyuck; Heo, Moon-Beom; Jee, Gyu-In

2015-08-21

Autonomous vehicles require highly reliable navigation capabilities. For example, a lane-following method cannot be applied in an intersection without lanes, and since typical lane detection is performed using a straight-line model, errors can occur when the lateral distance is estimated in curved sections due to a model mismatch. Therefore, this paper proposes a localization method that uses GPS/DR error estimation based on a lane detection method with curved lane models, stop line detection, and curve matching in order to improve the performance during waypoint following procedures. The advantage of using the proposed method is that position information can be provided for autonomous driving through intersections, in sections with sharp curves, and in curved sections following a straight section. The proposed method was applied in autonomous vehicles at an experimental site to evaluate its performance, and the results indicate that the positioning achieved accuracy at the sub-meter level.

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.

Persisting roughness when deposition stops.

Science.gov (United States)

Schwartz, Moshe; Edwards, S F

2004-12-01

Useful theories for growth of surfaces under random deposition of material have been developed by several authors. The simplest theory is that introduced by Edwards and Wilkinson (EW), which is linear and soluble. Its nonlinear generalization by Kardar, Parisi, and Zhang (KPZ) resulted in many subsequent studies. Yet both EW and KPZ theories contain an unphysical feature. When deposition of material is stopped, both theories predict that as time tends to infinity, the surface becomes flat. In fact, of course, the final surface is not flat, but simply has no gradients larger than the gradient related to the angle of repose. We modify the EW and KPZ theories to accommodate this feature and study the consequences for the simpler system which is a modification of the EW equation. In spite of the fact that the equation describing the evolution of the surface is not linear, we find that the steady state in the presence of noise is not very different in the long-wavelength limit from that of the linear EW equation. The situation is quite different from that of EW when deposition stops. Initially there is still some rearrangement of the surface, but that stops as everywhere on the surface the gradient is less than that related to the angle of repose. The most interesting feature observed after deposition stops is the emergence of history-dependent steady-state distributions.

How to Stop Biting Your Nails

Medline Plus

Full Text Available ... of hangnails, or other triggers, such as boredom, stress, or anxiety. By figuring out what causes you to bite your nails, you can figure out how to avoid these situations and develop a plan to stop. Just knowing when you’re inclined to bite may help solve the problem. Try to gradually stop biting ...

Using virtual environment for autonomous vehicle algorithm validation

Science.gov (United States)

Levinskis, Aleksandrs

2018-04-01

This paper describes possible use of modern game engine for validating and proving the concept of algorithm design. As the result simple visual odometry algorithm will be provided to show the concept and go over all workflow stages. Some of stages will involve using of Kalman filter in such a way that it will estimate optical flow velocity as well as position of moving camera located at vehicle body. In particular Unreal Engine 4 game engine will be used for generating optical flow patterns and ground truth path. For optical flow determination Horn and Schunck method will be applied. As the result, it will be shown that such method can estimate position of the camera attached to vehicle with certain displacement error respect to ground truth depending on optical flow pattern. For displacement rate RMS error is calculating between estimated and actual position.

Technology Improvement for the High Reliability LM-2F Launch Vehicle

Institute of Scientific and Technical Information of China (English)

QIN Tong; RONG Yi; ZHENG Liwei; ZHANG Zhi

2017-01-01

The Long March 2F (LM-2F) launch vehicle,the only launch vehicle designed for manned space flight in China,successfully launched the Tiangong 2 space laboratory and the Shenzhou ll manned spaceship into orbits in 2016 respectively.In this study,it introduces the technological improvements for enhancing the reliability of the LM-2F launch vehicle in the aspects of general technology,control system,manufacture and ground support system.The LM2F launch vehicle will continue to provide more contributions to the Chinese Space Station Project with its high reliability and 100％ success rate.

Leptonic mono-top from single stop production at the LHC

Energy Technology Data Exchange (ETDEWEB)

Duan, Guang Hua [CAS Key Laboratory of Theoretical Physics, Institute of Theoretical Physics,Chinese Academy of Sciences,Beijing 100190 (China); Hikasa, Ken-ichi [Department of Physics, Tohoku University,Sendai 980-8578 (Japan); Wu, Lei [Department of Physics and Institute of Theoretical Physics, Nanjing Normal University,Nanjing, Jiangsu 210023 (China); ARC Centre of Excellence for Particle Physics at the Terascale,School of Physics, The University of Sydney,NSW 2006 (Australia); Yang, Jin Min [CAS Key Laboratory of Theoretical Physics, Institute of Theoretical Physics,Chinese Academy of Sciences,Beijing 100190 (China); Department of Physics, Tohoku University,Sendai 980-8578 (Japan); Zhang, Mengchao [Center for Theoretical Physics and Universe, Institute for Basic Science (IBS),Daejeon 34051 (Korea, Republic of)

2017-03-16

Top squark (stop) can be produced via QCD interaction but also the electroweak interaction at the LHC. In this paper, we investigate the observability of the associated production of stop and chargino, pp→t̃{sub 1}χ̃{sub 1}{sup −}, in compressed electroweakino scenarios at 14 TeV LHC. Due to small mass splitting between the lightest neutralino (χ̃{sub 1}{sup 0}) and chargino (χ̃{sub 1}{sup −}), the single stop production can give the mono-top signature through the stop decay t̃{sub 1}→tχ̃{sub 1}{sup 0}. We analyze the leptonic mono-top channel of the single stop production and propose a lab-frame observable cos θ{sub bℓ} to reduce the SM backgrounds. We find that such leptonic mono-top events from the single stop production can be probed at 2σ level at the HL-LHC if m{sub t̃{sub 1}}<760 GeV and m{sub χ̃{sub 1{sup 0}}}<150 GeV. Given a discovery of the stop and a measurement of the single stop production cross section, the stop mixing angle can also be determined from the single stop production at the HL-LHC.

An interactive physics-based unmanned ground vehicle simulator leveraging open source gaming technology: progress in the development and application of the virtual autonomous navigation environment (VANE) desktop

Science.gov (United States)

Rohde, Mitchell M.; Crawford, Justin; Toschlog, Matthew; Iagnemma, Karl D.; Kewlani, Guarav; Cummins, Christopher L.; Jones, Randolph A.; Horner, David A.

2009-05-01

It is widely recognized that simulation is pivotal to vehicle development, whether manned or unmanned. There are few dedicated choices, however, for those wishing to perform realistic, end-to-end simulations of unmanned ground vehicles (UGVs). The Virtual Autonomous Navigation Environment (VANE), under development by US Army Engineer Research and Development Center (ERDC), provides such capabilities but utilizes a High Performance Computing (HPC) Computational Testbed (CTB) and is not intended for on-line, real-time performance. A product of the VANE HPC research is a real-time desktop simulation application under development by the authors that provides a portal into the HPC environment as well as interaction with wider-scope semi-automated force simulations (e.g. OneSAF). This VANE desktop application, dubbed the Autonomous Navigation Virtual Environment Laboratory (ANVEL), enables analysis and testing of autonomous vehicle dynamics and terrain/obstacle interaction in real-time with the capability to interact within the HPC constructive geo-environmental CTB for high fidelity sensor evaluations. ANVEL leverages rigorous physics-based vehicle and vehicle-terrain interaction models in conjunction with high-quality, multimedia visualization techniques to form an intuitive, accurate engineering tool. The system provides an adaptable and customizable simulation platform that allows developers a controlled, repeatable testbed for advanced simulations. ANVEL leverages several key technologies not common to traditional engineering simulators, including techniques from the commercial video-game industry. These enable ANVEL to run on inexpensive commercial, off-the-shelf (COTS) hardware. In this paper, the authors describe key aspects of ANVEL and its development, as well as several initial applications of the system.

High-speed ground transportation development outside United States

Energy Technology Data Exchange (ETDEWEB)

Eastham, T.R. [Queen`s Univ., Kingston, Ontario (United Kingdom)

1995-09-01

This paper surveys the state of high-speed (in excess of 200 km/h) ground-transportation developments outside the United States. Both high-speed rail and Maglev systems are covered. Many vehicle systems capable of providing intercity service in the speed range 200--500 km/h are or will soon be available. The current state of various technologies, their implementation, and the near-term plans of countries that are most active in high-speed ground transportation development are reported.

Illumination compensation in ground based hyperspectral imaging

Science.gov (United States)

Wendel, Alexander; Underwood, James

2017-07-01

Hyperspectral imaging has emerged as an important tool for analysing vegetation data in agricultural applications. Recently, low altitude and ground based hyperspectral imaging solutions have come to the fore, providing very high resolution data for mapping and studying large areas of crops in detail. However, these platforms introduce a unique set of challenges that need to be overcome to ensure consistent, accurate and timely acquisition of data. One particular problem is dealing with changes in environmental illumination while operating with natural light under cloud cover, which can have considerable effects on spectral shape. In the past this has been commonly achieved by imaging known reference targets at the time of data acquisition, direct measurement of irradiance, or atmospheric modelling. While capturing a reference panel continuously or very frequently allows accurate compensation for illumination changes, this is often not practical with ground based platforms, and impossible in aerial applications. This paper examines the use of an autonomous unmanned ground vehicle (UGV) to gather high resolution hyperspectral imaging data of crops under natural illumination. A process of illumination compensation is performed to extract the inherent reflectance properties of the crops, despite variable illumination. This work adapts a previously developed subspace model approach to reflectance and illumination recovery. Though tested on a ground vehicle in this paper, it is applicable to low altitude unmanned aerial hyperspectral imagery also. The method uses occasional observations of reference panel training data from within the same or other datasets, which enables a practical field protocol that minimises in-field manual labour. This paper tests the new approach, comparing it against traditional methods. Several illumination compensation protocols for high volume ground based data collection are presented based on the results. The findings in this paper are

Analyzing Vehicle Fuel Saving Opportunities through Intelligent Driver Feedback

Energy Technology Data Exchange (ETDEWEB)

Gonder, J.; Earleywine, M.; Sparks, W.

2012-06-01

Driving style changes, e.g., improving driver efficiency and motivating driver behavior changes, could deliver significant petroleum savings. This project examines eliminating stop-and-go driving and unnecessary idling, and also adjusting acceleration rates and cruising speeds to ideal levels to quantify fuel savings. Such extreme adjustments can result in dramatic fuel savings of over 30%, but would in reality only be achievable through automated control of vehicles and traffic flow. In real-world driving, efficient driving behaviors could reduce fuel use by 20% on aggressively driven cycles and by 5-10% on more moderately driven trips. A literature survey was conducted of driver behavior influences, and pertinent factors from on-road experiments with different driving styles were observed. This effort highlighted important driver influences such as surrounding vehicle behavior, anxiety over trying to get somewhere quickly, and the power/torque available from the vehicle. Existing feedback approaches often deliver efficiency information and instruction. Three recommendations for maximizing fuel savings from potential drive cycle improvement are: (1) leveraging applications with enhanced incentives, (2) using an approach that is easy and widely deployable to motivate drivers, and (3) utilizing connected vehicle and automation technologies to achieve large and widespread efficiency improvements.

A polynomial chaos approach to the analysis of vehicle dynamics under uncertainty

Science.gov (United States)

Kewlani, Gaurav; Crawford, Justin; Iagnemma, Karl

2012-05-01

The ability of ground vehicles to quickly and accurately analyse their dynamic response to a given input is critical to their safety and efficient autonomous operation. In field conditions, significant uncertainty is associated with terrain and/or vehicle parameter estimates, and this uncertainty must be considered in the analysis of vehicle motion dynamics. Here, polynomial chaos approaches that explicitly consider parametric uncertainty during modelling of vehicle dynamics are presented. They are shown to be computationally more efficient than the standard Monte Carlo scheme, and experimental results compared with the simulation results performed on ANVEL (a vehicle simulator) indicate that the method can be utilised for efficient and accurate prediction of vehicle motion in realistic scenarios.

Intelligent Terrain Analysis and Tactical Support System (ITATSS) for Unmanned Ground Vehicles

National Research Council Canada - National Science Library

Jones, Randolph M; Arkin, Ron; Sidki, Nahid

2005-01-01

...). The system enable unmanned combat and support vehicles to achieve significant new levels of autonomy, mobility, rapid response, coordination and effectiveness, while simultaneously enriching human...

Trajectories and Maneuvers of Surrounding Vehicles with Panoramic Camera Arrays

DEFF Research Database (Denmark)

Dueholm, Jacob Velling; Kristoffersen, Miklas Strøm; Satzoda, Ravi K.

2016-01-01

Vision-based research for intelligent vehicles have traditionally focused on specific regions around a vehicle, such as a front looking camera for, e.g., lane estimation. Traffic scenes are complex and vital information could be lost in unobserved regions. This paper proposes a framework that uses...... four visual sensors for a full surround view of a vehicle in order to achieve an understanding of surrounding vehicle behaviors. The framework will assist the analysis of naturalistic driving studies by automating the task of data reduction of the observed trajectories. To this end, trajectories...... are estimated using a vehicle detector together with a multiperspective optimized tracker in each view. The trajectories are transformed to a common ground plane, where they are associated between perspectives and analyzed to reveal tendencies around the ego-vehicle. The system is tested on sequences from 2.5 h...

On poisson-stopped-sums that are mixed poisson

OpenAIRE

Valero Baya, Jordi; Pérez Casany, Marta; Ginebra Molins, Josep

2013-01-01

Maceda (1948) characterized the mixed Poisson distributions that are Poisson-stopped-sum distributions based on the mixing distribution. In an alternative characterization of the same set of distributions here the Poisson-stopped-sum distributions that are mixed Poisson distributions is proved to be the set of Poisson-stopped-sums of either a mixture of zero-truncated Poisson distributions or a zero-modification of it. Peer Reviewed

Electron stopping powers for transport calculations

International Nuclear Information System (INIS)

Berger, M.J.

1988-01-01

The reliability of radiation transport calculations depends on the accuracy of the input cross sections. Therefore, it is essential to review and update the cross sections from time to time. Even though the main interest of the author's group at NBS is in transport calculations and their applications, the group spends almost as much time on the analysis and preparation of cross sections as on the development of transport codes. Stopping powers, photon attenuation coefficients, bremsstrahlung cross sections, and elastic-scattering cross sections in recent years have claimed attention. This chapter deals with electron stopping powers (with emphasis on collision stopping powers), and reviews the state of the art as reflected by Report 37 of the International Commission on Radiation Units and Measurements

Design optimisation of a flywheel hybrid vehicle

Energy Technology Data Exchange (ETDEWEB)

Kok, D.B.

1999-11-04

This thesis describes the design optimisation of a flywheel hybrid vehicle with respect to fuel consumption and exhaust gas emissions. The driveline of this passenger car uses two power sources: a small spark ignition internal combustion engine with three-way catalyst, and a highspeed flywheel system for kinetic energy storage. A custom-made continuously variable transmission (CVT) with so-called i{sup 2} control transports energy between these power sources and the vehicle wheels. The driveline includes auxiliary systems for hydraulic, vacuum and electric purposes. In this fully mechanical driveline, parasitic energy losses determine the vehicle's fuel saving potential to a large extent. Practicable energy loss models have been derived to quantify friction losses in bearings, gearwheels, the CVT, clutches and dynamic seals. In addition, the aerodynamic drag in the flywheel system and power consumption of auxiliaries are charted. With the energy loss models available, a calculation procedure is introduced to optimise the flywheel as a subsystem in which the rotor geometry, the safety containment, and the vacuum system are designed for minimum energy use within the context of automotive applications. A first prototype of the flywheel system was tested experimentally and subsequently redesigned to improve rotordynamics and safety aspects. Coast-down experiments with the improved version show that the energy losses have been lowered significantly. The use of a kinetic energy storage device enables the uncoupling of vehicle wheel power and engine power. Therefore, the engine can be smaller and it can be chosen to operate in its region of best efficiency in start-stop mode. On a test-rig, the measured engine fuel consumption was reduced with more than 30 percent when the engine is intermittently restarted with the aid of the flywheel system. Although the start-stop mode proves to be advantageous for fuel consumption, exhaust gas emissions increase temporarily

Stop search in the compressed region via semileptonic decays

Energy Technology Data Exchange (ETDEWEB)

Cheng, Hsin-Chia; Gao, Christina; Li, Lingfeng; Neill, Nicolás A. [Department of Physics, University of California,Davis, California 95616 (United States)

2016-05-05

In supersymmetric extensions of the Standard Model, the superpartners of the top quark (stops) play the crucial role in addressing the naturalness problem. For direct pair-production of stops with each stop decaying into a top quark plus the lightest neutralino, the standard stop searches have difficulty finding the stop for a compressed spectrum where the mass difference between the stop and the lightest neutralino is close to the top quark mass, because the events look too similar to the large tt̄ background. With an additional hard ISR jet, the two neutralinos from the stop decays are boosted in the opposite direction and they can give rise to some missing transverse energy. This may be used to distinguish the stop decays from the backgrounds. In this paper we study the semileptonic decay of such signal events for the compressed mass spectrum. Although the neutrino from the W decay also produces some missing transverse energy, its momentum can be reconstructed from the kinematic assumptions and mass-shell conditions. It can then be subtracted from the total missing transverse momentum to obtain the neutralino contribution. Because it suffers from less backgrounds, we show that the semileptonic decay channel has a better discovery reach than the fully hadronic decay channel along the compressed line m{sub t̃}−m{sub χ̃}≈m{sub t}. With 300 fb{sup −1}, the 13 TeV LHC can discover the stop up to 500 GeV, covering the most natural parameter space region.

STARCODES, Stopping Power and Ranges for Electrons, Protons, He

International Nuclear Information System (INIS)

2000-01-01

1 - Description of program or function: The 'STAR CODES', ESTAR, PSTAR, and ASTAR, calculate stopping-power and range tables for electrons, protons, and helium ions (alphas), according to methods described in ICRU Reports 37 and 39. 2 - Method of solution: Collision stopping powers are calculated from the theory of Bethe (1930, 1932), with a density-effect correction evaluated according to Sternheimer (1952, 1982). The stopping-power formula contains an important parameter, the mean excitation energy (I-value), which characterizes the stopping properties of a material. The codes provide output for electrons in any stopping material (279 provided) and for protons and helium ions in 74 materials. The calculations include the 1) Collision stopping power, 2) Radiative stopping power (electrons only), 3) Nuclear stopping power (protons and helium ions), 4) Total stopping power, 5) CSDA range, 6) Projected range (protons and helium ions), 7) Density effect parameter (electrons), 8) Radiation yield (electrons), and 9) Detour factor (protons and helium ions). Standard energy grids and files of elements w/ionization-excitation information are included with lookup table capabilities. 3 - Restrictions on the complexity of the problem: The minimum energies used in the calculations are at 1 KeV (protons and helium ions) and 10 KeV (electrons), and the maximum are 1 GeV. The standard energy grids are set at 81 for electrons, equally spaced (logarithmically), 133 for protons, and 122 for helium ions. The lower energy electron calculations (< 10 KeV) have up to 5-10% errors and are considered too fallable

Intercomparison of Unmanned Aerial Vehicle and Ground-Based Narrow Band Spectrometers Applied to Crop Trait Monitoring in Organic Potato Production

Directory of Open Access Journals (Sweden)

Marston Héracles Domingues Franceschini

2017-06-01

Full Text Available Vegetation properties can be estimated using optical sensors, acquiring data on board of different platforms. For instance, ground-based and Unmanned Aerial Vehicle (UAV-borne spectrometers can measure reflectance in narrow spectral bands, while different modelling approaches, like regressions fitted to vegetation indices, can relate spectra with crop traits. Although monitoring frameworks using multiple sensors can be more flexible, they may result in higher inaccuracy due to differences related to the sensors characteristics, which can affect information sampling. Also organic production systems can benefit from continuous monitoring focusing on crop management and stress detection, but few studies have evaluated applications with this objective. In this study, ground-based and UAV spectrometers were compared in the context of organic potato cultivation. Relatively accurate estimates were obtained for leaf chlorophyll (RMSE = 6.07 µg·cm−2, leaf area index (RMSE = 0.67 m2·m−2, canopy chlorophyll (RMSE = 0.24 g·m−2 and ground cover (RMSE = 5.5% using five UAV-based data acquisitions, from 43 to 99 days after planting. These retrievals are slightly better than those derived from ground-based measurements (RMSE = 7.25 µg·cm−2, 0.85 m2·m−2, 0.28 g·m−2 and 6.8%, respectively, for the same period. Excluding observations corresponding to the first acquisition increased retrieval accuracy and made outputs more comparable between sensors, due to relatively low vegetation cover on this date. Intercomparison of vegetation indices indicated that indices based on the contrast between spectral bands in the visible and near-infrared, like OSAVI, MCARI2 and CIg provided, at certain extent, robust outputs that could be transferred between sensors. Information sampling at plot level by both sensing solutions resulted in comparable discriminative potential concerning advanced stages of late blight incidence. These results indicate that optical

Assessing rear-end crash potential in urban locations based on vehicle-by-vehicle interactions, geometric characteristics and operational conditions.

Science.gov (United States)

Dimitriou, Loukas; Stylianou, Katerina; Abdel-Aty, Mohamed A

2018-03-01

Rear-end crashes are one of the most frequently occurring crash types, especially in urban networks. An understanding of the contributing factors and their significant association with rear-end crashes is of practical importance and will help in the development of effective countermeasures. The objective of this study is to assess rear-end crash potential at a microscopic level in an urban environment, by investigating vehicle-by-vehicle interactions. To do so, several traffic parameters at the individual vehicle level have been taken into consideration, for capturing car-following characteristics and vehicle interactions, and to investigate their effect on potential rear-end crashes. In this study rear-end crash potential was estimated based on stopping distance between two consecutive vehicles, and four rear-end crash potential cases were developed. The results indicated that 66.4% of the observations were estimated as rear-end crash potentials. It was also shown that rear-end crash potential was presented when traffic flow and speed standard deviation were higher. Also, locational characteristics such as lane of travel and location in the network were found to affect drivers' car following decisions and additionally, it was shown that speeds were lower and headways higher when Heavy Goods Vehicles lead. Finally, a model-based behavioral analysis based on Multinomial Logit regression was conducted to systematically identify the statistically significant variables in explaining rear-end risk potential. The modeling results highlighted the significance of the explanatory variables associated with rear-end crash potential, however it was shown that their effect varied among different model configurations. The outcome of the results can be of significant value for several purposes, such as real-time monitoring of risk potential, allocating enforcement units in urban networks and designing targeted proactive safety policies. Copyright © 2018 Elsevier Ltd. All rights

Ready to stop

DEFF Research Database (Denmark)

Molitoris, Joseph; Dribe, Martin

2016-01-01

the Roteman Database for Stockholm, Sweden between 1878 and 1926 to examine the association of socioeconomic status and fertility and the adoption of stopping behaviour during the city's transition. Using piecewise constant hazard models and logistic regression, we find that a clear class pattern arises...

Dynamic force profile in hydraulic hybrid vehicles: a numerical investigation

Science.gov (United States)

Mohaghegh-Motlagh, Amin; Elahinia, Mohammad H.

2010-04-01

A hybrid hydraulic vehicle (HHV) combines a hydraulic sub-system with the conventional drivetrain in order to improve fuel economy for heavy vehicles. The added hydraulic module manages the storage and release of fluid power necessary to assist the motion of the vehicle. The power collected by a pump/motor (P/M) from the regenerative braking phase is stored in a high-pressure accumulator and then released by the P/M to the driveshaft during the acceleration phase. This technology is effective in significantly improving fuel-economy for heavy-class vehicles with frequent stop-and-go drive schedules. Despite improved fuel economy and higher vehicle acceleration, noise and vibrations are one of the main problems of these vehicles. The dual function P/Ms are the main source of noise and vibration in a HHV. This study investigates the dynamics of a P/M and particularly the profile and frequency-dependence of the dynamic forces generated by a bent-axis P/M unit. To this end, the fluid dynamics side of the problem has been simplified for investigating the system from a dynamics perspective. A mathematical model of a bent axis P/M has been developed to investigate the cause of vibration and noise in HHVs. The forces are calculated in time and frequency domains. The results of this work can be used to study the vibration response of the chassis and to design effective vibration isolation systems for HHVs.

Study of Model Predictive Control for Path-Following Autonomous Ground Vehicle Control under Crosswind Effect

Directory of Open Access Journals (Sweden)

Fitri Yakub

2016-01-01

Full Text Available We present a comparative study of model predictive control approaches of two-wheel steering, four-wheel steering, and a combination of two-wheel steering with direct yaw moment control manoeuvres for path-following control in autonomous car vehicle dynamics systems. Single-track mode, based on a linearized vehicle and tire model, is used. Based on a given trajectory, we drove the vehicle at low and high forward speeds and on low and high road friction surfaces for a double-lane change scenario in order to follow the desired trajectory as close as possible while rejecting the effects of wind gusts. We compared the controller based on both simple and complex bicycle models without and with the roll vehicle dynamics for different types of model predictive control manoeuvres. The simulation result showed that the model predictive control gave a better performance in terms of robustness for both forward speeds and road surface variation in autonomous path-following control. It also demonstrated that model predictive control is useful to maintain vehicle stability along the desired path and has an ability to eliminate the crosswind effect.

Light stops and fine-tuning in MSSM

Energy Technology Data Exchange (ETDEWEB)

Cici, Ali; Kirca, Zerrin; Uen, Cem Salih [Uludag Univ., Department of Physics, Bursa (Turkey)

2018-01-15

We discuss the fine-tuning issue within the MSSM framework. Following the idea that the fine-tuning can measure effects of some missing mechanism, we impose non-universal gaugino masses at the GUT scale, and explore the low scale implications. We realize that the fine-tuning parametrized with Δ{sub EW} can be as low as zero. We consider the stop mass with a special importance and focus on the mass scales as m{sub t} ≤ 700 GeV, which are excluded by the current experiments when the stop decays into a neutralino along with a top quark or a chargino along with a bottom quark. We find that the stop mass can be as low as about 250 GeV with Δ{sub EW} ∝ 50. We find that the solutions in this region can be excluded only up to 60% when stop decays into a neutralino-top quark, and 50% when it decays into a chargino-b quark. Setting 65% CL to be potential exclusion and 95% to be pure exclusion limit such solutions will be tested in near future experiments, which are conducted with higher luminosity. In addition to stop, the region with low fine-tuning and light stops predicts masses for the other supersymmetric particles such as m{sub b} >or similar 700 GeV, m{sub τ} >or similar 1 TeV, m{sub χ{sub 1}{sup {sub ±}}} >or similar 120 GeV. The details for the mass scales and decay rates are also provided by tables of benchmark points. (orig.)

Light stops and fine-tuning in MSSM

Science.gov (United States)

Çiçi, Ali; Kırca, Zerrin; Ün, Cem Salih

2018-01-01

We discuss the fine-tuning issue within the MSSM framework. Following the idea that the fine-tuning can measure effects of some missing mechanism, we impose non-universal gaugino masses at the GUT scale, and explore the low scale implications. We realize that the fine-tuning parametrized with Δ _{EW} can be as low as zero. We consider the stop mass with a special importance and focus on the mass scales as m_{\\tilde{t}} ≤ 700 GeV, which are excluded by the current experiments when the stop decays into a neutralino along with a top quark or a chargino along with a bottom quark. We find that the stop mass can be as low as about 250 GeV with Δ _{EW} ˜ 50. We find that the solutions in this region can be exluded only up to 60% when stop decays into a neutralino-top quark, and 50% when it decays into a chargino-b quark. Setting 65% CL to be potential exclusion and 95% to be pure exclusion limit such solutions will be tested in near future experiments, which are conducted with higher luminosity. In addition to stop, the region with low fine-tuning and light stops predicts masses for the other supersymmetric particles such as m_{\\tilde{b}} ≳ 700 GeV, m_{\\tilde{τ }} ≳ 1 TeV, m_{\\tilde{χ }1^{± }} ≳ 120 GeV. The details for the mass scales and decay rates are also provided by tables of benchmark points.

Effect of oxygen-breathing during a decompression-stop on bubble-induced platelet activation after an open-sea air dive: oxygen-stop decompression.

Science.gov (United States)

Pontier, J-M; Lambrechts, K

2014-06-01

We highlighted a relationship between decompression-induced bubble formation and platelet micro-particle (PMP) release after a scuba air-dive. It is known that decompression protocol using oxygen-stop accelerates the washout of nitrogen loaded in tissues. The aim was to study the effect of oxygen deco-stop on bubble formation and cell-derived MP release. Healthy experienced divers performed two scuba-air dives to 30 msw for 30 min, one with an air deco-stop and a second with 100% oxygen deco-stop at 3 msw for 9 min. Bubble grades were monitored with ultrasound and converted to the Kisman integrated severity score (KISS). Blood samples for cell-derived micro-particle analysis (AnnexinV for PMP and CD31 for endothelial MP) were taken 1 h before and after each dive. Mean KISS bubble score was significantly lower after the dive with oxygen-decompression stop, compared to the dive with air-decompression stop (4.3 ± 7.3 vs. 32.7 ± 19.9, p air-breathing decompression stop, we observed an increase of the post-dive mean values of PMP (753 ± 245 vs. 381 ± 191 ng/μl, p = 0.003) but no significant change in the oxygen-stop decompression dive (329 ± 215 vs. 381 +/191 ng/μl, p = 0.2). For the post-dive mean values of endothelial MP, there was no significant difference between both the dives. The Oxygen breathing during decompression has a beneficial effect on bubble formation accelerating the washout of nitrogen loaded in tissues. Secondary oxygen-decompression stop could reduce bubble-induced platelet activation and the pro-coagulant activity of PMP release preventing the thrombotic event in the pathogenesis of decompression sickness.

Design of permanent block stopping to resist strata convergence

Energy Technology Data Exchange (ETDEWEB)

Ray, R.E.

1985-11-01

Conventional concrete block plastered with a cementitious coating is the most common material used in the construction of permanent stoppings to direct airflow in underground mines in the US. All mines experience various degrees of strata convergence depending on depth of overburden, geological conditions, and type of roof support employed. Strata convergence will cause cracks and joint openings in masonry stoppings, resulting in significant air leakage losses. Where strata convergence is severe, complete structural failure of the stopping can ultimately occur. Reconstruction of damaged or destroyed stoppings adds expensive overheads to mining operations, and even greater expenses are incurred from the additional fan horsepower required to overcome leakage losses. Ideally, a stopping should maintain high resistance to airflow while yielding to strata convergence. By properly incorporating a polyisocyanurate rigid foam material within the masonry block structure, stopping service life can be increased in mines experiencing strata convergence problems such as floor heave, roof loading, and lateral rib movement.

A signature correlation study of ground target VHF/UHF ISAR imagery

Science.gov (United States)

Gatesman, Andrew J.; Beaudoin, Christopher J.; Giles, Robert H.; Kersey, William T.; Waldman, Jerry; Carter, Steve; Nixon, William E.

2003-09-01

VV and HH-polarized radar signatures of several ground targets were acquired in the VHF/UHF band (171-342 MHz) by using 1/35th scale models and an indoor radar range operating from 6 to 12 GHz. Data were processed into medianized radar cross sections as well as focused, ISAR imagery. Measurement validation was confirmed by comparing the radar cross section of a test object with a method of moments radar cross section prediction code. The signatures of several vehicles from three vehicle classes (tanks, trunks, and TELs) were measured and a signature cross-correlation study was performed. The VHF/UHF band is currently being exploited for its foliage penetration ability, however, the coarse image resolution which results from the relatively long radar wavelengths suggests a more challenging target recognition problem. One of the study's goals was to determine the amount of unique signature content in VHF/UHF ISAR imagery of military ground vehicles. Open-field signatures are compared with each other as well as with simplified shapes of similar size. Signatures were also acquired on one vehicle in a variety of configurations to determine the impact of monitor target variations on the signature content at these frequencies.

Intelligence Level Performance Standards Research for Autonomous Vehicles.

Science.gov (United States)

Bostelman, Roger B; Hong, Tsai H; Messina, Elena

2015-01-01

United States and European safety standards have evolved to protect workers near Automatic Guided Vehicles (AGV's). However, performance standards for AGV's and mobile robots have only recently begun development. Lessons can be learned from research and standards efforts for mobile robots applied to emergency response and military applications. Research challenges, tests and evaluations, and programs to develop higher intelligence levels for vehicles can also used to guide industrial AGV developments towards more adaptable and intelligent systems. These other efforts also provide useful standards development criteria for AGV performance test methods. Current standards areas being considered for AGVs are for docking, navigation, obstacle avoidance, and the ground truth systems that measure performance. This paper provides a look to the future with standards developments in both the performance of vehicles and the dynamic perception systems that measure intelligent vehicle performance.

Could stops lighten the top?

International Nuclear Information System (INIS)

Bilal, A.; Ellis, J.; Fogli, G.L.

1990-01-01

The analysis of the presently available electroweak data including radiative corrections in the standard model suggests that the top quark weighs more than the Z 0 . We examine whether squark loops in the minimal supersymmetric model, particularly those involving stops (partners of the top quark), could reduce substantially the preferred range of top quark masses. Given the present lower bounds on squark masses, we find that stop effects can reduce the central value of m t by at most a few GeV, although they do make a very heavy top quark increasingly unlikely. (orig.)

Mechanical Properties Experimental Study of Engineering Vehicle Refurbished Tire

Science.gov (United States)

Qiang, Wang; Xiaojie, Qi; Zhao, Yang; Yunlong, Wang; Guotian, Wang; Degang, Lv

2018-05-01

The vehicle refurbished tire test system was constructed, got load-deformation, load-stiffness, and load-compression ratio property laws of engineering vehicle refurbished tire under the working condition of static state and ground contact, and built radial direction loading deformation mathematics model of 26.5R25 engineering vehicle refurbished tire. The test results show that radial-direction and side-direction deformation value is a little less than that of the new tire. The radial-direction stiffness and compression ratio of engineering vehicle refurbished tire were greatly influenced by radial-direction load and air inflation pressure. When load was certain, radial-direction stiffness would increase with air inflation pressure increasing. When air inflation pressure was certain, compression ratio of engineering vehicle refurbished tire would enlarge with radial-direction load increasing, which was a little less than that of the new and the same type tire. Aging degree of old car-case would exert a great influence on deformation property of engineering vehicle refurbished tire, thus engineering vehicle refurbished tires are suitable to the working condition of low tire pressure and less load.

Situational awareness for unmanned ground vehicles in semi-structured environments

Science.gov (United States)

Goodsell, Thomas G.; Snorrason, Magnus; Stevens, Mark R.

2002-07-01

Situational Awareness (SA) is a critical component of effective autonomous vehicles, reducing operator workload and allowing an operator to command multiple vehicles or simultaneously perform other tasks. Our Scene Estimation & Situational Awareness Mapping Engine (SESAME) provides SA for mobile robots in semi-structured scenes, such as parking lots and city streets. SESAME autonomously builds volumetric models for scene analysis. For example, a SES-AME equipped robot can build a low-resolution 3-D model of a row of cars, then approach a specific car and build a high-resolution model from a few stereo snapshots. The model can be used onboard to determine the type of car and locate its license plate, or the model can be segmented out and sent back to an operator who can view it from different viewpoints. As new views of the scene are obtained, the model is updated and changes are tracked (such as cars arriving or departing). Since the robot's position must be accurately known, SESAME also has automated techniques for deter-mining the position and orientation of the camera (and hence, robot) with respect to existing maps. This paper presents an overview of the SESAME architecture and algorithms, including our model generation algorithm.

GPS/DR Error Estimation for Autonomous Vehicle Localization

Directory of Open Access Journals (Sweden)

Byung-Hyun Lee

2015-08-01

Full Text Available Autonomous vehicles require highly reliable navigation capabilities. For example, a lane-following method cannot be applied in an intersection without lanes, and since typical lane detection is performed using a straight-line model, errors can occur when the lateral distance is estimated in curved sections due to a model mismatch. Therefore, this paper proposes a localization method that uses GPS/DR error estimation based on a lane detection method with curved lane models, stop line detection, and curve matching in order to improve the performance during waypoint following procedures. The advantage of using the proposed method is that position information can be provided for autonomous driving through intersections, in sections with sharp curves, and in curved sections following a straight section. The proposed method was applied in autonomous vehicles at an experimental site to evaluate its performance, and the results indicate that the positioning achieved accuracy at the sub-meter level.

Stopping test of iterative methods for solving PDE

International Nuclear Information System (INIS)

Wang Bangrong

1991-01-01

In order to assure the accuracy of the numerical solution of the iterative method for solving PDE (partial differential equation), the stopping test is very important. If the coefficient matrix of the system of linear algebraic equations is strictly diagonal dominant or irreducible weakly diagonal dominant, the stopping test formulas of the iterative method for solving PDE is proposed. Several numerical examples are given to illustrate the applications of the stopping test formulas

Stopping power, its meaning, and its general characteristics

International Nuclear Information System (INIS)

Inokuti, Mitio.

1995-01-01

This essay presents remarks on the meaning of stopping, power and of its magnitude. More precisely, the first set of remarks concerns the connection of stopping power with elements of particle-transport theory, which describes particle transport and its consequences in full detail, including its stochastic aspects. The second set of remarks concerns the magnitude of the stopping power of a material and its relation with the material's electronic structure and other properties

STOP4-7 Nederland. Resultaten 2010-2011

NARCIS (Netherlands)

Geijsen, L.; Veerman, J.W.; Bastiaanssen, I.L.W.

2011-01-01

STOP4-7 is een multimodale interventie voor kinderen van 4 tot 7 jaar met ernstige externaliserende gedragsproblemen en hun opvoeders en leerkrachten. Het doel van STOP4-7 is het aanleren en versterken van sociale en probleemoplossende vaardigheden en het verminderen van ongewenst gedrag. Daarvoor

Using the Stop Transmission of Polio (STOP) Program to Develop a South Sudan Expanded Program on Immunization Workforce.

Science.gov (United States)

Tchoualeu, Dieula D; Hercules, Margaret A; Mbabazi, William B; Kirbak, Anthony L; Usman, Abdulmumini; Bizuneh, Ketema; Sandhu, Hardeep S

2017-07-01

In 2009, the international Stop Transmission of Polio (STOP) program began supporting the Global Polio Eradication Initiative in the Republic of South Sudan to address shortages of human resources and strengthen acute flaccid paralysis surveillance. Workforce capacity support is provided to the South Sudan Expanded Program on Immunization by STOP volunteers, implementing partners, and non-governmental organizations. In 2013, the Polio Technical Advisory Group recommended that South Sudan transition key technical support from external partners to national staff as part of the Polio Eradication and Endgame Strategic Plan, 2013-2018. To assist in this transition, the South Sudan Expanded Program on Immunization human resources development project was launched in 2015. This 3-year project aims to build national workforce capacity as a legacy of the STOP program by training 56 South Sudanese at national and state levels with the intent that participants would become Ministry of Health staff on their successful completion of the project. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America.

Dynamic tire pressure sensor for measuring ground vibration.

Science.gov (United States)

Wang, Qi; McDaniel, James Gregory; Wang, Ming L

2012-11-07

This work presents a convenient and non-contact acoustic sensing approach for measuring ground vibration. This approach, which uses an instantaneous dynamic tire pressure sensor (DTPS), possesses the capability to replace the accelerometer or directional microphone currently being used for inspecting pavement conditions. By measuring dynamic pressure changes inside the tire, ground vibration can be amplified and isolated from environmental noise. In this work, verifications of the DTPS concept of sensing inside the tire have been carried out. In addition, comparisons between a DTPS, ground-mounted accelerometer, and directional microphone are made. A data analysis algorithm has been developed and optimized to reconstruct ground acceleration from DTPS data. Numerical and experimental studies of this DTPS reveal a strong potential for measuring ground vibration caused by a moving vehicle. A calibration of transfer function between dynamic tire pressure change and ground acceleration may be needed for different tire system or for more accurate application.

A Fully-Distributed Heuristic Algorithm for Control of Autonomous Vehicle Movements at Isolated Intersections

Directory of Open Access Journals (Sweden)

Abdallah A. Hassan

2014-12-01

Full Text Available Optimizing autonomous vehicle movements through roadway intersections is a challenging problem. It has been demonstrated in the literature that traditional traffic control, such as traffic signal and stop sign control are not optimal especially for heavy traffic demand levels. Alternatively, centralized autonomous vehicle control strategies are costly and not scalable given that the ability of a central controller to track and schedule the movement of hundreds of vehicles in real-time is questionable. Consequently, in this paper a fully distributed algorithm is proposed where vehicles in the vicinity of an intersection continuously cooperate with each other to develop a schedule that allows them to safely proceed through the intersection while incurring minimum delay. Unlike other distributed approaches described in the literature, the wireless communication constraints are considered in the design of the control algorithm. Specifically, the proposed algorithm requires vehicles heading to an intersection to communicate only with neighboring vehicles, while the lead vehicles on each approach lane share information to develop a complete intersection utilization schedule. The scheduling rotates between vehicles to identify higher traffic volumes and favor vehicles coming from heavier lanes to minimize the overall intersection delay. The simulated experiments show significant reductions in the average delay using the proposed approach compared to other methods reported in the literature and reduction in the maximum delay experienced by a vehicle especially in cases of heavy traffic demand levels.

Shielding factors for vehicles to gamma radiation from activity deposited on structures and ground surfaces

International Nuclear Information System (INIS)

Lauridsen, B.; Hedemann Jensen, P.

1982-04-01

This report describes a measuring procedure for the determination of shielding factors for vehicles passing through areas that have been contaminated by activity released to the atmosphere from a reactor accident. A simulated radiation field from fallout has been approximated by a point source that has been placed in a matrix around and above the vehicle. Modifying factors are discussed such as mutual shielding by nearby buildings and passengers. From measurements on different vehicles with and without passengers shielding factors are recommended for ordinary cars and busses in both urban and open areas, and areas with single family houses. (author)

Nonlinear effects contributing to hand-stopping tones in a horn.

Science.gov (United States)

Ebihara, Takayasu; Yoshikawa, Shigeru

2013-05-01

Hand stopping is a technique for playing the French horn while closing the bell relatively tightly using the right hand. The resulting timbre is called "penetrating" and "metallic." The effect of hand stopping on the horn input impedance has been studied, but the tone quality has hardly ever been considered. In the present paper, the dominant physical cause of the stopped-tone quality is discussed in detail. Numerical calculations of the transmission function of the stopped-horn model and the measurements of both sound pressure and wall vibration in hand stopping are carried out. They strongly suggest that the metallicness of the stopped tone is characterized by the generation of higher harmonics extending over 10 kHz due to the rapidly corrugating waveform and that the associated wall vibration on the bell may be responsible for this higher harmonic generation. However, excitation experiments and immobilization experiments performed to elucidate the relationship between sound radiation and wall vibration deny their correlation. Instead, the measurement result of the mouthpiece pressure in hand stopping suggests that minute wave corrugations peculiar to the metallic stopped tones are probably formed by nonlinear sound propagation along the bore.

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.

Intelligent Vehicle Health Management

Science.gov (United States)

Paris, Deidre E.; Trevino, Luis; Watson, Michael D.

2005-01-01

As a part of the overall goal of developing Integrated Vehicle Health Management systems for aerospace vehicles, the NASA Faculty Fellowship Program (NFFP) at Marshall Space Flight Center has performed a pilot study on IVHM principals which integrates researched IVHM technologies in support of Integrated Intelligent Vehicle Management (IIVM). IVHM is the process of assessing, preserving, and restoring system functionality across flight and ground systems (NASA NGLT 2004). The framework presented in this paper integrates advanced computational techniques with sensor and communication technologies for spacecraft that can generate responses through detection, diagnosis, reasoning, and adapt to system faults in support of INM. These real-time responses allow the IIVM to modify the affected vehicle subsystem(s) prior to a catastrophic event. Furthermore, the objective of this pilot program is to develop and integrate technologies which can provide a continuous, intelligent, and adaptive health state of a vehicle and use this information to improve safety and reduce costs of operations. Recent investments in avionics, health management, and controls have been directed towards IIVM. As this concept has matured, it has become clear the INM requires the same sensors and processing capabilities as the real-time avionics functions to support diagnosis of subsystem problems. New sensors have been proposed, in addition, to augment the avionics sensors to support better system monitoring and diagnostics. As the designs have been considered, a synergy has been realized where the real-time avionics can utilize sensors proposed for diagnostics and prognostics to make better real-time decisions in response to detected failures. IIVM provides for a single system allowing modularity of functions and hardware across the vehicle. The framework that supports IIVM consists of 11 major on-board functions necessary to fully manage a space vehicle maintaining crew safety and mission

Can I Stop Myself From Having a Wet Dream? (For Teens)

Science.gov (United States)

... Can I Stop Myself From Having a Wet Dream? KidsHealth / For Teens / Can I Stop Myself From Having a Wet Dream? Print Can I stop myself from having a wet dream? – Tom* You really can't stop wet dreams, ...

Operator Informational Needs for Multiple Autonomous Small Vehicles

Science.gov (United States)

Trujillo, Anna C.; Fan, Henry; Cross, Charles D.; Hempley, Lucas E.; Cichella, Venanzio; Puig-Navarro, Javier; Mehdi, Syed Bilal

2015-01-01

With the anticipated explosion of small unmanned aerial vehicles, it is highly likely that operators will be controlling fleets of autonomous vehicles. To fulfill the promise of autonomy, vehicle operators will not be concerned with manual control of the vehicle; instead, they will deal with the overall mission. Furthermore, the one operator to many vehicles is becoming a constant meme with various industries including package delivery, search and rescue, and utility companies. In order for an operator to concurrently control several vehicles, his station must look and behave very differently than the current ground control station instantiations. Furthermore, the vehicle will have to be much more autonomous, especially during non-normal operations, in order to accommodate the knowledge deficit or the information overload of the operator in charge of several vehicles. The expected usage increase of small drones requires presenting the operational information generated by a fleet of heterogeneous autonomous agents to an operator. NASA Langley Research Center's Autonomy Incubator has brought together researchers in various disciplines including controls, trajectory planning, systems engineering, and human factors to develop an integrated system to study autonomy issues. The initial human factors effort is focusing on mission displays that would give an operator the overall status of all autonomous agents involved in the current mission. This paper will discuss the specifics of the mission displays for operators controlling several vehicles.

Development and psychometric properties of the Suicidality: Treatment Occurring in Paediatrics (STOP) Suicidality Assessment Scale (STOP-SAS) in children and adolescents.

Science.gov (United States)

Flamarique, I; Santosh, P; Zuddas, A; Arango, C; Purper-Ouakil, D; Hoekstra, P J; Coghill, D; Schulze, U; Dittmann, R W; Buitelaar, J K; Lievesley, K; Frongia, R; Llorente, C; Méndez, I; Sala, R; Fiori, F; Castro-Fornieles, J

2016-12-13

To create a self-reported, internet-based questionnaire for the assessment of suicide risk in children and adolescents. As part of the EU project 'Suicidality: Treatment Occurring in Paediatrics' (STOP project), we developed web-based Patient Reported Outcome Measures (PROMs) for children and adolescents and for proxy reports by parents and clinicians in order to assess suicidality. Based on a literature review, expert panels and focus groups of patients, we developed the items of the STOP Suicidality Assessment Scale (STOP-SAS) in Spanish and English, translated it into four more languages, and optimized it for web-based presentation using the HealthTracker TM platform. Of the total 19 questions developed for the STOP-SAS, four questions that assess low-level suicidality were identified as screening questions (three of them for use with children, and all four for use with adolescents, parents and clinicians). A total of 395 adolescents, 110 children, 637 parents and 716 clinicians completed the questionnaire using the HealthTracker TM , allowing us to evaluate the internal consistency and convergent validity of the STOP-SAS with the clinician-rated Columbia Suicide Severity Rating Scale (C-SSRS). Validity was also assessed with the receiver operating characteristic (ROC) area of the STOP-SAS with the C-SSRS. The STOP-SAS comprises 19 items in its adolescent, parent, and clinician versions, and 14 items in its children's version. Good internal consistency was found for adolescents (Cronbach's alpha: 0.965), children (Cronbach's alpha: 0.922), parents (Cronbach's alpha: 0.951) and clinicians (Cronbach's alpha: 0.955) versions. A strong correlation was found between the STOP-SAS and the C-SSRS for adolescents (r:0.670), parents (r:0.548), clinicians (r:0.863) and children (r:0.654). The ROC area was good for clinicians' (0.917), adolescents' (0.834) and parents' (0.756) versions but only fair (0.683) for children's version. The STOP-SAS is a comprehensive, web

Start-Stop Test Procedures on the PEMFC Stack Level

DEFF Research Database (Denmark)

Mitzel, Jens; Nygaard, Frederik; Veltzé, Sune

The test is addressed to investigate the influence on stack durability of a long stop followed by a restart of a stack. Long stop should be defined as a stop in which the anodic compartment is fully filled by air due to stack leakages. In systems, leakage level of the stack is low and time to fil...

Iterated Local Search Algorithm with Strategic Oscillation for School Bus Routing Problem with Bus Stop Selection

Directory of Open Access Journals (Sweden)

Mohammad Saied Fallah Niasar

2017-02-01

Full Text Available he school bus routing problem (SBRP represents a variant of the well-known vehicle routing problem. The main goal of this study is to pick up students allocated to some bus stops and generate routes, including the selected stops, in order to carry students to school. In this paper, we have proposed a simple but effective metaheuristic approach that employs two features: first, it utilizes large neighborhood structures for a deeper exploration of the search space; second, the proposed heuristic executes an efficient transition between the feasible and infeasible portions of the search space. Exploration of the infeasible area is controlled by a dynamic penalty function to convert the unfeasible solution into a feasible one. Two metaheuristics, called N-ILS (a variant of the Nearest Neighbourhood with Iterated Local Search algorithm and I-ILS (a variant of Insertion with Iterated Local Search algorithm are proposed to solve SBRP. Our experimental procedure is based on the two data sets. The results show that N-ILS is able to obtain better solutions in shorter computing times. Additionally, N-ILS appears to be very competitive in comparison with the best existing metaheuristics suggested for SBRP

Near-ground cooling efficacies of trees and high-albedo surfaces

Energy Technology Data Exchange (ETDEWEB)

Levinson, Ronnen M. [Univ. of California, Berkeley, CA (United States). Dept. of Mechanical Engineering

1997-05-01

Daytime summer urban heat islands arise when the prevalence of dark-colored surfaces and lack of vegetation make a city warmer than neighboring countryside. Two frequently-proposed summer heat island mitigation measures are to plant trees and to increase the albedo (solar reflectivity) of ground surfaces. This dissertation examines the effects of these measures on the surface temperature of an object near the ground, and on solar heating of air near the ground. Near-ground objects include people, vehicles, and buildings. The variation of the surface temperature of a near-ground object with ground albedo indicates that a rise in ground albedo will cool a near-ground object only if the object`s albedo exceeds a critical value. This critical value of object albedo depends on wind speed, object geometry, and the height of the atmospheric thermal boundary layer. It ranges from 0.15 to 0.37 for a person. If an object has typical albedo of 0.3, increasing the ground albedo by.

CDC Vital Signs: New Hope for Stopping HIV

Science.gov (United States)

... 27 MB] Read the MMWR Science Clips New Hope for Stopping HIV Testing and Medical Care Save ... acquired immunodeficiency syndrome) and early death. There's new hope today for stopping HIV in the US. Medicines ( ...

Development and Evaluation of an Economic-Driving Assistance Program for Transit Vehicles

OpenAIRE

Baoxin Han; Wanjing Ma; Hanzhou Xie

2012-01-01

This paper focuses on development and evaluation of an economic-driving assistance program for transit vehicles (EDTV) which can minimize energy consumption, air pollution emission of buses, and improve the level of service of transit system as well. Taking advantage of the latest advances in information and communication technologies, the EDTV system can provide bus drivers with optimal recommended bus holding times at near-side bus stops and dynamic bus speed to adapt to the real-time traff...

Fuel economy of hybrid fuel-cell vehicles

Science.gov (United States)

Ahluwalia, Rajesh K.; Wang, X.; Rousseau, A.

The potential improvement in fuel economy of a mid-size fuel-cell vehicle by combining it with an energy storage system has been assessed. An energy management strategy is developed and used to operate the direct hydrogen, pressurized fuel-cell system in a load-following mode and the energy storage system in a charge-sustaining mode. The strategy places highest priority on maintaining the energy storage system in a state where it can supply unanticipated boost power when the fuel-cell system alone cannot meet the power demand. It is found that downsizing a fuel-cell system decreases its efficiency on a drive cycle which is compensated by partial regenerative capture of braking energy. On a highway cycle with limited braking energy the increase in fuel economy with hybridization is small but on the stop-and-go urban cycle the fuel economy can improve by 27%. On the combined highway and urban drive cycles the fuel economy of the fuel-cell vehicle is estimated to increase by up to 15% by hybridizing it with an energy storage system.

Stopping power for particle therapy: the generic library libdEdx and clinically relevant stopping-power ratios for light ions

DEFF Research Database (Denmark)

Lühr, Armin Christian; Toftegaard, Jakob; Kantemiris, Ioannis

2012-01-01

to be known accurately for dosimetry. Methods: An open-source computer library called libdEdx (library for energy loss per unit path length, dE/dx, calculations) is developed, providing stopping-power data from data tables and computer programs as well as a stopping-power formula comprising a large list...

Depression - stopping your medicines

Science.gov (United States)

... this page: //medlineplus.gov/ency/patientinstructions/000570.htm Depression - stopping your medicines To use the sharing features ... prescription medicines you may take to help with depression, anxiety, or pain. Like any medicine, there are ...

Space vehicle electromechanical system and helical antenna winding fixture

Science.gov (United States)

Judd, Stephen; Dallmann, Nicholas; Guenther, David; Enemark, Donald; Seitz, Daniel; Martinez, John; Storms, Steven

2017-12-26

A space vehicle electromechanical system may employ an architecture that enables convenient and practical testing, reset, and retesting of solar panel and antenna deployment on the ground. A helical antenna winding fixture may facilitate winding and binding of the helical antenna.

Robotic Ground-Penetrating-Radar (GPR) Surveys to Support the 2014 Greenland Inland Traverse

Science.gov (United States)

2016-06-01

return via the same route to Thule in late May for over- winter equipment storage. The first 100 km of the route onto the main ice cap is ridden with...vehicle has a nominal ground pressure of 20 kPa through 0.51 m diameter all-terrain vehicle (ATV) tires . Yeti there- fore can drive safely over most

Real-time identification of vehicle motion-modes using neural networks

Science.gov (United States)

Wang, Lifu; Zhang, Nong; Du, Haiping

2015-01-01

A four-wheel ground vehicle has three body-dominated motion-modes, that is, bounce, roll, and pitch motion-modes. Real-time identification of these motion-modes can make vehicle suspensions, in particular, active suspensions, target on the dominant motion-mode and apply appropriate control strategies to improve its performance with less power consumption. Recently, a motion-mode energy method (MEM) was developed to identify the vehicle body motion-modes. However, this method requires the measurement of full vehicle states and road inputs, which are not always available in practice. This paper proposes an alternative approach to identify vehicle primary motion-modes with acceptable accuracy by employing neural networks (NNs). The effectiveness of the trained NNs is verified on a 10-DOF full-car model under various types of excitation inputs. The results confirm that the proposed method is effective in determining vehicle primary motion-modes with comparable accuracy to the MEM method. Experimental data is further used to validate the proposed method.

Grounding Lines Detecting Using LANDSAT8 Oli and CRYOSAT-2 Data Fusion

Science.gov (United States)

Li, F.; Guo, Y.; Zhang, Y.; Zhang, S.

2018-04-01

The grounding zone is the region where ice transitions from grounded ice sheet to freely floating ice shelf, grounding lines are actually more of a zone, typically over several kilometers. The mass loss from Antarctica is strongly linked to changes in the ice shelves and their grounding lines, since the variation in the grounding line can result in very rapid changes in glacier and ice-shelf behavior. Based on remote sensing observations, five global Antarctic grounding line products have been released internationally, including MOA, ASAID, ICESat, MEaSUREs, and Synthesized grounding lines. However, the five products could not provide the annual grounding line products of the whole Antarctic, even some products have stopped updating, which limits the time series analysis of Antarctic material balance to a certain extent. Besides, the accurate of single remote-sensing data based grounding line products is far from satisficed. Therefore, we use algorithms to extract grounding lines with SAR and Cryosat-2 data respectively, and combine the results of two kinds of grounding lines to obtain new products, we obtain a mature grounding line extraction algorithm process, so that we can realize the extraction of grounding line of the Antarctic each year in the future. The comparison between fusion results and the MOA product results indicate that there is a maximum deviation of 188.67 meters between the MOA product and the fusion result.

A Compact Wideband Dual-Polarized Antenna with Harmonic Suppression Using Nonuniform Defected Ground Structure

Directory of Open Access Journals (Sweden)

Lana Damaj

2015-01-01

Full Text Available A wideband dual-polarized coplanar waveguide (CPW fed antenna integrating a wide stop-band filter is presented. The designed filter is based on a nonuniform defected ground structure (DGS in order to obtain a wide stop-band and a compact size. This filter is used to reject harmonics and spurious radiation arising from the RF front end. The complete structure (antenna and filter has been optimized to have a compact size of 0.6×0.6λ02 (λ0 being the free-space wavelength at the lowest operating frequency. The realized antenna operates in the frequency range between 2.7 GHz and 5.9 GHz (bandwidth of about 74%. The isolation between feeding ports is more than 18 dB. The complete structure has a wide stop-band characteristic (103% for harmonic rejection. The simulated numerical results have been confirmed with measurements.

Are Stopped Strings Preferred in Sad Music?

Directory of Open Access Journals (Sweden)

David Huron

2017-01-01

Full Text Available String instruments may be played either with open strings (where the string vibrates between the bridge and a hard wooden nut or with stopped strings (where the string vibrates between the bridge and a performer's finger pressed against the fingerboard. Compared with open strings, stopped strings permit the use of vibrato and exhibit a darker timbre. Inspired by research on the timbre of sad speech, we test whether there is a tendency to use stopped strings in nominally sad music. Specifically, we compare the proportion of potentially open-to-stopped strings in a sample of slow, minor-mode movements with matched major-mode movements. By way of illustration, a preliminary analysis of Samuel Barber's famous Adagio from his Opus 11 string quartet shows that the selected key (B-flat minor provides the optimum key for minimizing open string tones. However, examination of a broader controlled sample of quartet movements by Haydn, Mozart and Beethoven failed to exhibit the conjectured relationship. Instead, major-mode movements were found to avoid possible open strings more than slow minor-mode movements.

Navigation of the autonomous vehicle reverse movement

Science.gov (United States)

Rachkov, M.; Petukhov, S.

2018-02-01

The paper presents a mathematical formulation of the vehicle reverse motion along a multi-link polygonal trajectory consisting of rectilinear segments interconnected by nodal points. Relevance of the problem is caused by the need to solve a number of tasks: to save the vehicle in the event of а communication break by returning along the trajectory already passed, to avoid a turn on the ground in constrained obstacles or dangerous conditions, or a partial return stroke for the subsequent bypass of the obstacle and continuation of the forward movement. The method of navigation with direct movement assumes that the reverse path is elaborated by using landmarks. To measure landmarks on board, a block of cameras is placed on a vehicle controlled by the operator through the radio channel. Errors in estimating deviation from the nominal trajectory of motion are determined using the multidimensional correlation analysis apparatus based on the dynamics of a lateral deviation error and a vehicle speed error. The result of the experiment showed a relatively high accuracy in determining the state vector that provides the vehicle reverse motion relative to the reference trajectory with a practically acceptable error while returning to the start point.

Estimation of left-turning vehicle maneuvers for the assessment of pedestrian safety at intersections

Directory of Open Access Journals (Sweden)

Wael K.M. Alhajyaseen

2012-07-01

Full Text Available Improving pedestrian safety at intersections remains a critical issue. Although several types of safety countermeasures, such as reforming intersection layouts, have been implemented, methods have not yet been established to quantitatively evaluate the effects of these countermeasures before installation. One of the main issues in pedestrian safety is conflicts with turning vehicles. This study aims to develop an integrated model to represent the variations in the maneuvers of left-turners (left-hand traffic at signalized intersections that dynamically considers the vehicle reaction to intersection geometry and crossing pedestrians. The proposed method consists of four empirically developed stochastic sub-models, including a path model, free-flow speed profile model, lag/gap acceptance model, and stopping/clearing speed profile model. Since safety assessment is the main objective driving the development of the proposed model, this study uses post-encroachment time (PET and vehicle speed at the crosswalk as validation parameters. Preliminary validation results obtained by Monte Carlo simulation show that the proposed integrated model can realistically represent the variations in vehicle maneuvers as well as the distribution of PET and vehicle speeds at the crosswalk.

SAFER vehicle inspection: a multimodal robotic sensing platform

Science.gov (United States)

Page, David L.; Fougerolle, Yohan; Koschan, Andreas F.; Gribok, Andrei; Abidi, Mongi A.; Gorsich, David J.; Gerhart, Grant R.

2004-09-01

The current threats to U.S. security both military and civilian have led to an increased interest in the development of technologies to safeguard national facilities such as military bases, federal buildings, nuclear power plants, and national laboratories. As a result, the Imaging, Robotics, and Intelligent Systems (IRIS) Laboratory at The University of Tennessee (UT) has established a research consortium, known as SAFER (Security Automation and Future Electromotive Robotics), to develop, test, and deploy sensing and imaging systems for unmanned ground vehicles (UGV). The targeted missions for these UGV systems include -- but are not limited to --under vehicle threat assessment, stand-off check-point inspections, scout surveillance, intruder detection, obstacle-breach situations, and render-safe scenarios. This paper presents a general overview of the SAFER project. Beyond this general overview, we further focus on a specific problem where we collect 3D range scans of under vehicle carriages. These scans require appropriate segmentation and representation algorithms to facilitate the vehicle inspection process. We discuss the theory for these algorithms and present results from applying them to actual vehicle scans.

A study on optimization of hybrid drive train using Advanced Vehicle Simulator (ADVISOR)

Energy Technology Data Exchange (ETDEWEB)

Same, Adam; Stipe, Alex; Grossman, David; Park, Jae Wan [Department of Mechanical and Aeronautical Engineering, University of California, Davis, One Shields Ave, Davis, CA 95616 (United States)

2010-10-01

This study investigates the advantages and disadvantages of three hybrid drive train configurations: series, parallel, and ''through-the-ground'' parallel. Power flow simulations are conducted with the MATLAB/Simulink-based software ADVISOR. These simulations are then applied in an application for the UC Davis SAE Formula Hybrid vehicle. ADVISOR performs simulation calculations for vehicle position using a combined backward/forward method. These simulations are used to study how efficiency and agility are affected by the motor, fuel converter, and hybrid configuration. Three different vehicle models are developed to optimize the drive train of a vehicle for three stages of the SAE Formula Hybrid competition: autocross, endurance, and acceleration. Input cycles are created based on rough estimates of track geometry. The output from these ADVISOR simulations is a series of plots of velocity profile and energy storage State of Charge that provide a good estimate of how the Formula Hybrid vehicle will perform on the given course. The most noticeable discrepancy between the input cycle and the actual velocity profile of the vehicle occurs during deceleration. A weighted ranking system is developed to organize the simulation results and to determine the best drive train configuration for the Formula Hybrid vehicle. Results show that the through-the-ground parallel configuration with front-mounted motors achieves an optimal balance of efficiency, simplicity, and cost. ADVISOR is proven to be a useful tool for vehicle power train design for the SAE Formula Hybrid competition. This vehicle model based on ADVISOR simulation is applicable to various studies concerning performance and efficiency of hybrid drive trains. (author)

Life Science on the International Space Station Using the Next Generation of Cargo Vehicles

Science.gov (United States)

Robinson, J. A.; Phillion, J. P.; Hart, A. T.; Comella, J.; Edeen, M.; Ruttley, T. M.

2011-01-01

With the retirement of the Space Shuttle and the transition of the International Space Station (ISS) from assembly to full laboratory capabilities, the opportunity to perform life science research in space has increased dramatically, while the operational considerations associated with transportation of the experiments has changed dramatically. US researchers have allocations on the European Automated Transfer Vehicle (ATV) and Japanese H-II Transfer Vehicle (HTV). In addition, the International Space Station (ISS) Cargo Resupply Services (CRS) contract will provide consumables and payloads to and from the ISS via the unmanned SpaceX (offers launch and return capabilities) and Orbital (offers only launch capabilities) resupply vehicles. Early requirements drove the capabilities of the vehicle providers; however, many other engineering considerations affect the actual design and operations plans. To better enable the use of the International Space Station as a National Laboratory, ground and on-orbit facility development can augment the vehicle capabilities to better support needs for cell biology, animal research, and conditioned sample return. NASA Life scientists with experience launching research on the space shuttle can find the trades between the capabilities of the many different vehicles to be confusing. In this presentation we will summarize vehicle and associated ground processing capabilities as well as key concepts of operations for different types of life sciences research being launched in the cargo vehicles. We will provide the latest status of vehicle capabilities and support hardware and facilities development being made to enable the broadest implementation of life sciences research on the ISS.

Impacts of Launch Vehicle Fairing Size on Human Exploration Architectures

Science.gov (United States)

Jefferies, Sharon; Collins, Tim; Dwyer Cianciolo, Alicia; Polsgrove, Tara

2017-01-01

Human missions to Mars, particularly to the Martian surface, are grand endeavors that place extensive demands on ground infrastructure, launch capabilities, and mission systems. The interplay of capabilities and limitations among these areas can have significant impacts on the costs and ability to conduct Mars missions and campaigns. From a mission and campaign perspective, decisions that affect element designs, including those based on launch vehicle and ground considerations, can create effects that ripple through all phases of the mission and have significant impact on the overall campaign. These effects result in impacts to element designs and performance, launch and surface manifesting, and mission operations. In current Evolvable Mars Campaign concepts, the NASA Space Launch System (SLS) is the primary launch vehicle for delivering crew and payloads to cis-lunar space. SLS is currently developing an 8.4m diameter cargo fairing, with a planned upgrade to a 10m diameter fairing in the future. Fairing diameter is a driving factor that impacts many aspects of system design, vehicle performance, and operational concepts. It creates a ripple effect that influences all aspects of a Mars mission, including: element designs, grounds operations, launch vehicle design, payload packaging on the lander, launch vehicle adapter design to meet structural launch requirements, control and thermal protection during entry and descent at Mars, landing stability, and surface operations. Analyses have been performed in each of these areas to assess and, where possible, quantify the impacts of fairing diameter selection on all aspects of a Mars mission. Several potential impacts of launch fairing diameter selection are identified in each of these areas, along with changes to system designs that result. Solutions for addressing these impacts generally result in increased systems mass and propellant needs, which can further exacerbate packaging and flight challenges. This paper

A fiber Bragg grating acceleration sensor for ground surveillance

Science.gov (United States)

Jiang, Shaodong; Zhang, Faxiang; Lv, Jingsheng; Ni, Jiasheng; Wang, Chang

2017-10-01

Ground surveillance system is a kind of intelligent monitoring equipment for detecting and tracking the ground target. This paper presents a fiber Bragg grating (FBG) acceleration sensor for ground surveillance, which has the characteristics of no power supply, anti-electromagnetic interference, easy large-scale networking, and small size. Which make it able to achieve the advantage of the ground surveillance system while avoiding the shortcoming of the electric sensing. The sensor has a double cantilever beam structure with a sensitivity of 1000 pm/g. Field experiment has been carried out on a flood beach to examine the sensor performance. The result shows that the detection distance on the walking of personnel reaches 70m, and the detection distance on the ordinary motor vehicle reaches 200m. The performance of the FBG sensor can satisfy the actual needs of the ground surveillance system.

Seasonal associations and atmospheric transport distances of Fusarium collected with unmanned aerial vehicles and ground-based sampling devices

Science.gov (United States)

Schmale, David; Ross, Shane; Lin, Binbin

2014-05-01

Spores of fungi in the genus Fusarium may be transported through the atmosphere over long distances. Members of this genus are important pathogens and mycotoxin producers. New information is needed to characterize seasonal trends in atmospheric loads of Fusarium and to pinpoint the source(s) of inoculum at both local (farm) and regional (state or country) scales. Spores of Fusarium were collected from the atmosphere in an agricultural ecosystem in Blacksburg, VA, USA using a Burkard volumetric sampler (BVS) 1 m above ground level and autonomous unmanned aerial vehicles (UAVs) 100 m above ground level. More than 2,200 colony forming units (CFUs) of Fusarium were collected during 104 BVS sampling periods and 180 UAV sampling periods over four calendar years (2009-2012). Spore concentrations ranged from 0 to 13 and 0 to 23 spores m-3 for the BVS and the UAVs, respectively. Spore concentrations were generally higher in the fall, spring, and summer, and lower in the winter. Spore concentrations from the BVS were generally higher than those from the UAVs for both seasonal and hourly collections. Some of the species of Fusarium identified from our collections have not been previously reported in the state of Virginia. A Gaussian plume transport model was used to estimate distances to the potential inoculum source(s) by season. This work extends previous studies showing an association between atmospheric transport barriers (Lagrangian coherent structures or LCSs) and the movement of Fusarium in the lower atmosphere. An increased understanding of the aerobiology of Fusarium may contribute to new and improved control strategies for diseases causes by fusaria in the future.

A Narrative Approach to Detect the Vehicles using color, texture and edge based techniques

Directory of Open Access Journals (Sweden)

Gaurav Ravi

2016-01-01

Full Text Available Vehicle recognition is the chief stride in observing the speeding vehicles in a thruway. The feature arrangements caught by a stationary camera demonstrate to us that there’s a requirement for a vehicle location calculation which handles sudden light change furthermore the situations where the closer view converges away from plain sight. This paper gives us a study of different foundation subtraction systems that are utilized for recognizing the vehicles effectively. Vehicles proceeding onward street are of significance on the grounds that issues like movement blockage, monetary waste, sticking on the underpasses and over-extensions (if the vehicle going through is not of the passable size are connected with them. Index Terms—Vehicle Detection, video sequences, foreground, background, MATLAB, RGB conversion.

Stopping power. Projectile and target modeled as oscillators

International Nuclear Information System (INIS)

Stevanovic, N.; Nikezic, D.

2005-01-01

In this Letter the collision of two quantum harmonic oscillators was considered. The oscillators interact through the Coulomb interaction. Stopping power of projectile was calculated assuming that both, target and projectile may be excited. It has been shown that the frequency of the projectile oscillation, ω p influences on stopping power, particularly in the region of Bragg peak. If, ω p ->0 is substitute in the expression for stopping power derived in this Letter, then it comes to the form when the projectile has been treated as point like charged particle

Application of lap laser welding technology on stainless steel railway vehicles

Science.gov (United States)

Wang, Hongxiao; Wang, Chunsheng; He, Guangzhong; Li, Wei; Liu, Liguo

2016-10-01

Stainless steel railway vehicles with so many advantages, such as lightweight, antirust, low cost of maintenance and simple manufacturing process, so the production of high level stainless steel railway vehicles has become the development strategy of European, American and other developed nations. The current stainless steel railway vehicles body and structure are usually assembled by resistance spot welding process. The weak points of this process are the poor surface quality and bad airtight due to the pressure of electrodes. In this study, the partial penetration lap laser welding process was investigated to resolve the problems, by controlling the laser to stop at the second plate in the appropriate penetration. The lap laser welding joint of stainless steel railway vehicle car body with partial penetration has higher strength and surface quality than those of resistance spot welding joint. The biggest problem of lap laser welding technology is to find the balance of the strength and surface quality with different penetrations. The mechanism of overlap laser welding of stainless steel, mechanical tests, microstructure analysis, the optimization of welding parameters, analysis of fatigue performance, the design of laser welding stainless steel railway vehicles structure and the development of non-destructive testing technology were systematically studied before lap laser welding process to be applied in manufacture of railway vehicles. The results of the experiments and study show that high-quality surface state and higher fatigue strength can be achieved by the partial penetration overlap laser welding of the side panel structure, and the structure strength of the car body can be higher than the requirements of En12663, the standard of structural requirements of railway vehicles bodies. Our company has produced the stainless steel subway and high way railway vehicles by using overlap laser welding technology. The application of lap laser welding will be a big

Passive Earth Entry Vehicle Landing Test

Science.gov (United States)

Kellas, Sotiris

2017-01-01

Two full-scale passive Earth Entry Vehicles (EEV) with realistic structure, surrogate sample container, and surrogate Thermal Protection System (TPS) were built at NASA Langley Research Center (LaRC) and tested at the Utah Test and Training Range (UTTR). The main test objective was to demonstrate structural integrity and investigate possible impact response deviations of the realistic vehicle as compared to rigid penetrometer responses. With the exception of the surrogate TPS and minor structural differences in the back shell construction, the two test vehicles were identical in geometry and both utilized the Integrated Composite Stiffener Structure (ICoSS) structural concept in the forward shell. The ICoSS concept is a lightweight and highly adaptable composite concept developed at NASA LaRC specifically for entry vehicle TPS carrier structures. The instrumented test vehicles were released from a helicopter approximately 400 m above ground. The drop height was selected such that at least 98% of the vehicles terminal velocity would be achieved. While drop tests of spherical penetrometers and a low fidelity aerodynamic EEV model were conducted at UTTR in 1998 and 2000, this was the first time a passive EEV with flight-like structure, surrogate TPS, and sample container was tested at UTTR for the purpose of complete structural system validation. Test results showed that at a landing vertical speed of approximately 30 m/s, the test vehicle maintained structural integrity and enough rigidity to penetrate the sandy clay surface thus attenuating the landing load, as measured at the vehicle CG, to less than 600 g. This measured deceleration was found to be in family with rigid penetrometer test data from the 1998 and 2000 test campaigns. Design implications of vehicle structure/soil interaction with respect to sample container and sample survivability are briefly discussed.

Seamless Mode Switching for Shared Control of Semiautonomous Vehicles, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Whether it be a crew station, the Shuttle Remote Manipulator System (SRMS), an unmanned ground rover (UGV) or air vehicle (UAV), or teams thereof, the controllers...

On NonAsymptotic Optimal Stopping Criteria in Monte Carlo Simulations

KAUST Repository

Bayer, Christian; Hoel, Hakon; von Schwerin, Erik; Tempone, Raul

2014-01-01

We consider the setting of estimating the mean of a random variable by a sequential stopping rule Monte Carlo (MC) method. The performance of a typical second moment based sequential stopping rule MC method is shown to be unreliable in such settings both by numerical examples and through analysis. By analysis and approximations, we construct a higher moment based stopping rule which is shown in numerical examples to perform more reliably and only slightly less efficiently than the second moment based stopping rule.

Request-Centric Wireless Bus Information Management System

Directory of Open Access Journals (Sweden)

Ying-Chih Chen

2016-11-01

Full Text Available This invention relates to a wireless bus information management system, which includes bus stop and vehicle management subsystems. The management signals are transmittable between bus stops and the vehicle. Based on vehicle management signals, the bus stop management subsystem can obtain information about the bus route identification, the number of unoccupied seats, the intention to stop or not, etc. Similarly, with the bus stop management signals, the vehicle management subsystem can make the decision of stopping. Accordingly, when a passenger wants to get off the vehicle or there are unoccupied seats, the vehicle management subsystem will inform the bus stop management subsystem such that the passengers waiting at the bus stop may flexibly schedule their travel plan. The proposed distributed wireless system is detailed by a prototype implementation and a simulation analysis, which is shown to be feasible and scalable.

UAV-guided navigation for ground robot tele-operation in a military reconnaissance environment.

Science.gov (United States)

Chen, Jessie Y C

2010-08-01

A military reconnaissance environment was simulated to examine the performance of ground robotics operators who were instructed to utilise streaming video from an unmanned aerial vehicle (UAV) to navigate his/her ground robot to the locations of the targets. The effects of participants' spatial ability on their performance and workload were also investigated. Results showed that participants' overall performance (speed and accuracy) was better when she/he had access to images from larger UAVs with fixed orientations, compared with other UAV conditions (baseline- no UAV, micro air vehicle and UAV with orbiting views). Participants experienced the highest workload when the UAV was orbiting. Those individuals with higher spatial ability performed significantly better and reported less workload than those with lower spatial ability. The results of the current study will further understanding of ground robot operators' target search performance based on streaming video from UAVs. The results will also facilitate the implementation of ground/air robots in military environments and will be useful to the future military system design and training community.

High fluence effects on ion implantation stopping and range

International Nuclear Information System (INIS)

Selvi, S.; Tek, Z.; Oeztarhan, A.; Akbas, N.; Brown, I.G.

2005-01-01

We have developed a code STOPPO which can be used to modify the more-widely used ion implantation codes to more accurately predict the mean nuclear and electronic stopping power, preferential sputtering and range of heavy ions in monatomic target materials. In our simulations an effective atomic number and effective atomic mass are introduced into conveniently available analytical stopping cross-sections and a better fitting function for preferential sputtering yield is carefully evaluated for each ion implantation. The accuracy of the code confirmed experimentally by comparison with measured Rutherford backscattering spectrometry (RBS) concentration profiles for 130 keV Zr ions implanted into Be to fluences of 1 x 10 17 , 2 x 10 17 and 4 x 10 17 ions/cm 2 . We find a steady increase in the mean nuclear and electronic stopping powers of the target; the increase in nuclear stopping power is much greater than the increase in electronic stopping power

Launch vehicle tracking enhancement through Global Positioning System Metric Tracking

Science.gov (United States)

Moore, T. C.; Li, Hanchu; Gray, T.; Doran, A.

United Launch Alliance (ULA) initiated operational flights of both the Atlas V and Delta IV launch vehicle families in 2002. The Atlas V and Delta IV launch vehicles were developed jointly with the US Air Force (USAF) as part of the Evolved Expendable Launch Vehicle (EELV) program. Both Launch Vehicle (LV) families have provided 100% mission success since their respective inaugural launches and demonstrated launch capability from both Vandenberg Air Force Base (VAFB) on the Western Test Range and Cape Canaveral Air Force Station (CCAFS) on the Eastern Test Range. However, the current EELV fleet communications, tracking, & control architecture & technology, which date back to the origins of the space launch business, require support by a large and high cost ground footprint. The USAF has embarked on an initiative known as Future Flight Safety System (FFSS) that will significantly reduce Test Range Operations and Maintenance (O& M) cost by closing facilities and decommissioning ground assets. In support of the FFSS, a Global Positioning System Metric Tracking (GPS MT) System based on the Global Positioning System (GPS) satellite constellation has been developed for EELV which will allow both Ranges to divest some of their radar assets. The Air Force, ULA and Space Vector have flown the first 2 Atlas Certification vehicles demonstrating the successful operation of the GPS MT System. The first Atlas V certification flight was completed in February 2012 from CCAFS, the second Atlas V certification flight from VAFB was completed in September 2012 and the third certification flight on a Delta IV was completed October 2012 from CCAFS. The GPS MT System will provide precise LV position, velocity and timing information that can replace ground radar tracking resource functionality. The GPS MT system will provide an independent position/velocity S-Band telemetry downlink to support the current man-in-the-loop ground-based commanded destruct of an anomalous flight- The system

Electron and Positron Stopping Powers of Materials

Science.gov (United States)

SRD 7 NIST Electron and Positron Stopping Powers of Materials (PC database for purchase)   The EPSTAR database provides rapid calculations of stopping powers (collisional, radiative, and total), CSDA ranges, radiation yields and density effect corrections for incident electrons or positrons with kinetic energies from 1 keV to 10 GeV, and for any chemically defined target material.

Addressing production stops in the food industry

DEFF Research Database (Denmark)

Hansen, Zaza Nadja Lee; Herbert, Luke Thomas; Jacobsen, Peter

2014-01-01

This paper investigates the challenges in the food industry which causes the production lines to stop, illustrated by a case study of an SME size company in the baked goods sector in Denmark. The paper proposes key elements this sector needs to be aware of to effectively address production stops......, and gives examples of the unique challenges faced by the SME food industry....

The stopping rules for winsorized tree

Science.gov (United States)

Ch'ng, Chee Keong; Mahat, Nor Idayu

2017-11-01

Winsorized tree is a modified tree-based classifier that is able to investigate and to handle all outliers in all nodes along the process of constructing the tree. It overcomes the tedious process of constructing a classical tree where the splitting of branches and pruning go concurrently so that the constructed tree would not grow bushy. This mechanism is controlled by the proposed algorithm. In winsorized tree, data are screened for identifying outlier. If outlier is detected, the value is neutralized using winsorize approach. Both outlier identification and value neutralization are executed recursively in every node until predetermined stopping criterion is met. The aim of this paper is to search for significant stopping criterion to stop the tree from further splitting before overfitting. The result obtained from the conducted experiment on pima indian dataset proved that the node could produce the final successor nodes (leaves) when it has achieved the range of 70% in information gain.

Reusable Launch Vehicle Technology Program

Science.gov (United States)

Freeman, Delma C., Jr.; Talay, Theodore A.; Austin, R. Eugene

1997-01-01

Industry/NASA reusable launch vehicle (RLV) technology program efforts are underway to design, test, and develop technologies and concepts for viable commercial launch systems that also satisfy national needs at acceptable recurring costs. Significant progress has been made in understanding the technical challenges of fully reusable launch systems and the accompanying management and operational approaches for achieving a low cost program. This paper reviews the current status of the RLV technology program including the DC-XA, X-33 and X-34 flight systems and associated technology programs. It addresses the specific technologies being tested that address the technical and operability challenges of reusable launch systems including reusable cryogenic propellant tanks, composite structures, thermal protection systems, improved propulsion and subsystem operability enhancements. The recently concluded DC-XA test program demonstrated some of these technologies in ground and flight test. Contracts were awarded recently for both the X-33 and X-34 flight demonstrator systems. The Orbital Sciences Corporation X-34 flight test vehicle will demonstrate an air-launched reusable vehicle capable of flight to speeds of Mach 8. The Lockheed-Martin X-33 flight test vehicle will expand the test envelope for critical technologies to flight speeds of Mach 15. A propulsion program to test the X-33 linear aerospike rocket engine using a NASA SR-71 high speed aircraft as a test bed is also discussed. The paper also describes the management and operational approaches that address the challenge of new cost effective, reusable launch vehicle systems.

Intelligent systems for KSC ground processing

Science.gov (United States)

Heard, Astrid E.

1992-01-01

The ground processing and launch of Shuttle vehicles and their payloads is the primary task of Kennedy Space Center. It is a process which is largely manual and contains little inherent automation. Business is conducted today much as it was during previous NASA programs such as Apollo. In light of new programs and decreasing budgets, NASA must find more cost effective ways in which to do business while retaining the quality and safety of activities. Advanced technologies including artificial intelligence could cut manpower and processing time. This paper is an overview of the research and development in Al technology at KSC with descriptions of the systems which have been implemented, as well as a few under development which are promising additions to ground processing software. Projects discussed cover many facets of ground processing activities, including computer sustaining engineering, subsystem monitor and diagnosis tools and launch team assistants. The deployed Al applications have proven an effectiveness which has helped to demonstrate the benefits of utilizing intelligent software in the ground processing task.

One-stop endoscopic hernia surgery: efficient and satisfactory.

Science.gov (United States)

Voorbrood, C E H; Burgmans, J P J; Clevers, G J; Davids, P H P; Verleisdonk, E J M M; Schouten, N; van Dalen, T

2015-06-01

One-stop surgery offers patients diagnostic work-up and subsequent surgical treatment on the same day. In the present study, patient satisfaction and efficiency from an institutional perspective were evaluated in patients who were referred for one-stop endoscopic inguinal hernia repair. In a high-volume inguinal hernia clinic, all consecutive patients referred for one-stop surgical treatment, were registered prospectively. An instructed secretary screened patients for eligibility for the one-stop option when the appointment was made. Totally extraperitoneal hernia repair under general anaesthesia was the preferred operative technique. Patient's satisfaction, successful day surgery and institutional efficiency were evaluated. Between January 2010 and January 2012 a total of 349 patients (17 % of all patients in the hernia clinic) were referred for one-stop hernia repair. Mean age was 47.5 years and 96.3 % were males. Three hundred thirty-six patients underwent hernia surgery on the same day (96.3 %). In thirteen patients (3.7 %) no operative repair was done on the day of presentation due to an incorrect diagnosis (n = 7), a watchful waiting policy for asymptomatic hernia (n = 3), rescheduling due to a large scrotal hernia, and there were two "no shows". Following hernia repair 97 % of the patients were discharged on the same day, while ten patients required hospitalization. Based on the questionnaires the main satisfaction score among patients was 9.0 (8.89-9.17 95 % CI) on a scale ranging from 0 to 10. One-stop hernia surgery is feasible and satisfactory from an institutional as well as from a patient's perspective.

Simulation on effect of stopping nuclear power generation

International Nuclear Information System (INIS)

Yajima, Masayuki; Kumakura, Osamu; Sakurai, Norihisa; Nagata, Yutaka; Hattori, Tsuneaki

1990-01-01

The effects that the stopping of nuclear power generation exerts on the price of primary energy such as petroleum, LNG and coal and the trend of Japanese energy and economy are analyzed by using the medium term economy forecasting system. In the simulation, the case of stopping nuclear power generation in seven countries of OECD is supposed, and as for the process of stopping, two cases of immediate stopping and stopping by gradual reduction are set up. The models used for the simulation are the world energy model, the competition among energies model and the multiple category model. By the decrease of nuclear power generation, thermal power generation increases, and the demand of fossil fuel increases. As the result, the price of fossil fuel rises (the world energy model), and the price of fossil fuel imported to Japan rises. Also the quantity of fossil fuel import to Japan increase. These price rise and quantity increase exert deflation effect to Japanese economy (the multiple category model). The price rise of fossil fuel affects the competition among energies in Japan through the relative change of secondary energy price (the competition among energies model). The impact to the world and to Japan is discussed. (K.I.)

Launch vehicle operations cost reduction through artificial intelligence techniques

Science.gov (United States)

Davis, Tom C., Jr.

1988-01-01

NASA's Kennedy Space Center has attempted to develop AI methods in order to reduce the cost of launch vehicle ground operations as well as to improve the reliability and safety of such operations. Attention is presently given to cost savings estimates for systems involving launch vehicle firing-room software and hardware real-time diagnostics, as well as the nature of configuration control and the real-time autonomous diagnostics of launch-processing systems by these means. Intelligent launch decisions and intelligent weather forecasting are additional applications of AI being considered.

VHF/UHF imagery and RCS measurements of ground targets in forested terrain

Science.gov (United States)

Gatesman, Andrew J.; Beaudoin, Christopher J.; Giles, Robert H.; Waldman, Jerry; Nixon, William E.

2002-08-01

The monostatic VV and HH-polarized radar signatures of several targets and trees have been measured at foliage penetration frequencies (VHF/UHF) by using 1/35th scale models and an indoor radar range operating at X-band. An array of high-fidelity scale model ground vehicles and test objects as well as scaled ground terrain and trees have been fabricated for the study. Radar measurement accuracy has been confirmed by comparing the signature of a test object with a method of moments radar cross section prediction code. In addition to acquiring signatures of targets located on a smooth, dielectric ground plane, data have also been acquired with targets located in simulated wooded terrain that included scaled tree trunks and tree branches. In order to assure the correct backscattering behavior, all dielectric properties of live tree wood and moist soil were scaled properly to match the complex dielectric constant of the full-scale materials. The impact of the surrounding tree clutter on the VHF/UHF radar signatures of ground vehicles was accessed. Data were processed into high-resolution, polar-formatted ISAR imagery and signature comparisons are made between targets in open-field and forested scenarios.

When to stop drying fruit: Insights from hygrothermal modelling

International Nuclear Information System (INIS)

Defraeye, Thijs

2017-01-01

Highlights: • Partial dehydration reduces energy consumption and processing time and improves product quality. • This study gives a quantitative insight in when fruit drying should be stopped. • Decrease in dryer residence time of 2%, 24% and 70% are found for different stopping criteria. - Abstract: Stopping the drying process prior to complete dehydration reduces energy consumption and processing time but can also improve product quality. Using hygrothermal simulations, different stopping criteria are evaluated, which are based on the final water activity and residual moisture content in the fruit. Their impact on drying time and moisture redistribution kinetics inside fruit is quantified. One of the variants leads to a significant reduction in residence time in the dryer (24%), compared to full dehydration. For this variant, drying is stopped when the average moisture content in the sample reaches the value corresponding to an equilibrium water activity of 60% in the sample, as determined from the sorption isotherm. At the same time, this variant does not induce problems with fruit spoilage, as a sufficiently low water activity is reached after moisture redistribution during relaxation in the ambient environment. In addition, the relation of the drying time to the drying air temperature was quantified for all stopping criteria, as well as the impact of the humidity of the ambient environment in which the dried fruits are placed afterwards. This study gives a better quantitative insight in when fruit drying should be stopped, given specific drying conditions, without having to compromise food safety.

Stopping the unstoppable

CERN Multimedia

2002-01-01

How do you stop two very high energy proton beams circulating in opposite directions around a 27-kilometre ring? The answer is the beam dumps. Two tunnels, pointing in opposite directions, are being constructed at point 6 of the LHC. These will allow the beams to be directed into two large beam dumps housed at the ends of the tunnels.

Seismic stops for nuclear power plants

International Nuclear Information System (INIS)

Cloud, R.L.; Leung, J.S.M.; Anderson, P.H.

1989-01-01

In the regulated world of nuclear power, the need to have analytical proof of performance in hypothetical design-basis events such as earth quakes has placed a premium on design configurations that are mathematically tractable and easily analyzed. This is particularly true for the piping design. Depending on how the piping analyses are organized and on how old the plant is, there may be from 200 to 1000 separate piping runs to be designed, analyzed, and qualified. In this situation, the development of snubbers seemed like the answer to a piping engineer's prayer. At any place where seismic support was required but thermal motion had to be accommodated, a snubber could be specified. But, as experience has now shown, the program was solved only on paper. This article presents an alternative to conventional snubbers. These new devices, termed Seismic Stops are designed to replace snubbers directly and look like snubbers on the outside. But their design is based on a completely different principle. The original concept has adapted from early seismic-resistant pipe support designs used on fossil power plants in California. The fundamental idea is to provide a space envelope in which the pipe can expand freely between the hot and cold positions, but cannot move outside the envelope. Seismic Stops are designed to transmit any possible impact load, as would occur in an earthquake, away from the pipe itself to the Seismic Stop. The Seismic Stop pipe support is shown

SHIFT: server for hidden stops analysis in frame-shifted translation.

Science.gov (United States)

Gupta, Arun; Singh, Tiratha Raj

2013-02-23

Frameshift is one of the three classes of recoding. Frame-shifts lead to waste of energy, resources and activity of the biosynthetic machinery. In addition, some peptides synthesized after frame-shifts are probably cytotoxic which serve as plausible cause for innumerable number of diseases and disorders such as muscular dystrophies, lysosomal storage disorders, and cancer. Hidden stop codons occur naturally in coding sequences among all organisms. These codons are associated with the early termination of translation for incorrect reading frame selection and help to reduce the metabolic cost related to the frameshift events. Researchers have identified several consequences of hidden stop codons and their association with myriad disorders. However the wealth of information available is speckled and not effortlessly acquiescent to data-mining. To reduce this gap, this work describes an algorithmic web based tool to study hidden stops in frameshifted translation for all the lineages through respective genetic code systems. This paper describes SHIFT, an algorithmic web application tool that provides a user-friendly interface for identifying and analyzing hidden stops in frameshifted translation of genomic sequences for all available genetic code systems. We have calculated the correlation between codon usage frequencies and the plausible contribution of codons towards hidden stops in an off-frame context. Markovian chains of various order have been used to model hidden stops in frameshifted peptides and their evolutionary association with naturally occurring hidden stops. In order to obtain reliable and persuasive estimates for the naturally occurring and predicted hidden stops statistical measures have been implemented. This paper presented SHIFT, an algorithmic tool that allows user-friendly exploration, analysis, and visualization of hidden stop codons in frameshifted translations. It is expected that this web based tool would serve as a useful complement for

Goal-oriented path planning for ground and aerial vehicles

OpenAIRE

Signifredi, Andrea

2017-01-01

Nowadays autonomous robots are used in everyday life more than ever. The idea that motivate the develop of new autonomous application is to lessen the fatigue of repetitive works and to make safer the work that are difficult if done by humans alone. Another goal of autonomous robots is to improve precision and repetitiveness in the actuation of actions. Car makers are now showing to consider autonomous driving a ground braking functionality and one of the most important additions to their ass...

Theoretical model for calculation of molecular stopping power

International Nuclear Information System (INIS)

Xu, Y.J.

1984-01-01

A modified local plasma model based on the work of Linhard-Winther, Bethe, Brown, and Walske is established. The Gordon-Kim's molecular charged density model is employed to obtain a formula to evaluate the stopping power of many useful molecular systems. The stopping power of H 2 and He gas was calculated for incident proton energy ranging from 100 KeV to 2.5 MeV. The stopping power of O 2 , N 2 , and water vapor was also calculated for incident proton energy ranging from 40 keV to 2.5 MeV. Good agreement with experimental data was obtained. A discussion of molecular effects leading to departure from Bragg's rule is presented. The equipartition rule and the effect of nuclear momentum recoiling in stopping power are also discussed in the appendix. The calculation procedure presented hopefully can easily be extended to include the most useful organic systems such as the molecules composed of carbon, nitrogen, hydrogen and oxygen which are useful in radiation protection field

Higgs-Stoponium Mixing Near the Stop-Antistop Threshold

CERN Document Server

Bodwin, Geoffrey T; Wagner, Carlos E M

2016-01-01

Supersymmetric extensions of the standard model contain additional heavy neutral Higgs bosons that are coupled to heavy scalar top quarks (stops). This system exhibits interesting field theoretic phenomena when the Higgs mass is close to the stop-antistop production threshold. Existing work in the literature has examined the digluon-to-diphoton cross section near threshold and has focused on enhancements in the cross section that might arise either from the perturbative contributions to the Higgs-to-digluon and Higgs-to-diphoton form factors or from mixing of the Higgs boson with stoponium states. Near threshold, enhancements in the relevant amplitudes that go as inverse powers of the stop-antistop relative velocity require resummations of perturbation theory and/or nonperturbative treatments. We present a complete formulation of threshold effects at leading order in the stop-antistop relative velocity in terms of nonrelativistic effective field theory. We give detailed numerical calculations for the case in ...

Vertical Takeoff and Landing Vehicle with Increased Cruise Efficiency

Science.gov (United States)

Fredericks, William J. (Inventor); Moore, Mark D. (Inventor); Busan, Ronald C. (Inventor); Rothhaar, Paul M. (Inventor); North, David D. (Inventor); Langford, William M. (Inventor); Laws, Christopher T. (Inventor); Hodges, William T. (Inventor); Johns, Zachary R. (Inventor); Webb, Sandy R. (Inventor)

2018-01-01

Systems, methods, and devices are provided that combine an advance vehicle configuration, such as an advanced aircraft configuration, with the infusion of electric propulsion, thereby enabling a four times increase in range and endurance while maintaining a full vertical takeoff and landing ("VTOL") and hover capability for the vehicle. Embodiments may provide vehicles with both VTOL and cruise efficient capabilities without the use of ground infrastructure. An embodiment vehicle may comprise a wing configured to tilt through a range of motion, a first series of electric motors coupled to the wing and each configured to drive an associated wing propeller, a tail configured to tilt through the range of motion, a second series of electric motors coupled to the tail and each configured to drive an associated tail propeller, and an electric propulsion system connected to the first series of electric motors and the second series of electric motors.

Enabling unmanned capabilities in the tactical wheeled vehicle fleet of the future

Science.gov (United States)

Zych, Noah

2012-06-01

From transporting troops and weapons systems to supplying beans, bullets, and Band-Aids to front-line warfighters, tactical wheeled vehicles serve as the materiel backbone anywhere there are boots on the ground. Drawing from the U.S. Army's Tactical Wheeled Vehicle Strategy and the Marine Corps Vision & Strategy 2025 reports, one may conclude that the services have modest expectations for the introduction of large unmanned ground systems into operational roles in the next 15 years. However, the Department of Defense has already invested considerably in the research and development of full-size UGVs-and commanders deployed in both Iraq and Afghanistan have advocated the urgent fielding of early incarnations of this technology, believing it could make a difference on their battlefields today. For military UGVs to evolve from mere tactical advantages into strategic assets with developed doctrine, they must become as trustworthy as a well-trained warfighter in performing their assigned task. Starting with the Marine Corps' ongoing Cargo Unmanned Ground Vehicle program as a baseline, and informed by feedback from previously deployed subject matter experts, this paper examines the gaps which presently exist in UGVs from a mission-capable perspective. It then considers viable near-term technical solutions to meet today's functional requirements, as well as long-term development strategies to enable truly robust performance. With future conflicts expected to be characterized by increasingly complex operational environments and a broad spectrum of rapidly adapting threats, one of the largest challenges for unmanned ground systems will be the ability to exhibit agility in unpredictable circumstances.

Multi-Purpose Crew Vehicle Camera Asset Planning: Imagery Previsualization

Science.gov (United States)

Beaulieu, K.

2014-01-01

Using JSC-developed and other industry-standard off-the-shelf 3D modeling, animation, and rendering software packages, the Image Science Analysis Group (ISAG) supports Orion Project imagery planning efforts through dynamic 3D simulation and realistic previsualization of ground-, vehicle-, and air-based camera output.

Stopping time of a one-dimensional bounded quantum walk

International Nuclear Information System (INIS)

Luo Hao; Zhang Peng; Zhan Xiang; Xue Peng

2016-01-01

The stopping time of a one-dimensional bounded classical random walk (RW) is defined as the number of steps taken by a random walker to arrive at a fixed boundary for the first time. A quantum walk (QW) is a non-trivial generalization of RW, and has attracted a great deal of interest from researchers working in quantum physics and quantum information. In this paper, we develop a method to calculate the stopping time for a one-dimensional QW. Using our method, we further compare the properties of stopping time for QW and RW. We find that the mean value of the stopping time is the same for both of these problems. However, for short times, the probability for a walker performing a QW to arrive at the boundary is larger than that for a RW. This means that, although the mean stopping time of a quantum and classical walker are the same, the quantum walker has a greater probability of arriving at the boundary earlier than the classical walker. (paper)

Loading Deformation Characteristic Simulation Study of Engineering Vehicle Refurbished Tire

Science.gov (United States)

Qiang, Wang; Xiaojie, Qi; Zhao, Yang; Yunlong, Wang; Guotian, Wang; Degang, Lv

2018-05-01

The paper constructed engineering vehicle refurbished tire computer geometry model, mechanics model, contact model, finite element analysis model, did simulation study on load-deformation property of engineering vehicle refurbished tire by comparing with that of the new and the same type tire, got load-deformation of engineering vehicle refurbished tire under the working condition of static state and ground contact. The analysis result shows that change rules of radial-direction deformation and side-direction deformation of engineering vehicle refurbished tire are close to that of the new tire, radial-direction and side-direction deformation value is a little less than that of the new tire. When air inflation pressure was certain, radial-direction deformation linear rule of engineer vehicle refurbished tire would increase with load adding, however, side-direction deformation showed linear change rule, when air inflation pressure was low; and it would show increase of non-linear change rule, when air inflation pressure was very high.

Definition of technology development missions for early space stations orbit transfer vehicle serving. Phase 2, task 1: Space station support of operational OTV servicing

Science.gov (United States)

1983-01-01

Representative space based orbital transfer vehicles (OTV), ground based vehicle turnaround assessment, functional operational requirements and facilities, mission turnaround operations, a comparison of ground based versus space based tasks, activation of servicing facilities prior to IOC, fleet operations requirements, maintenance facilities, OTV servicing facilities, space station support requirements, and packaging for delivery are discussed.

Active debris removal GNC challenges over design and required ground validation

Science.gov (United States)

Colmenarejo, Pablo; Avilés, Marcos; di Sotto, Emanuele

2015-06-01

Because of the exponential growth of space debris, the access to space in the medium-term future is considered as being seriously compromised, particularly within LEO polar Sun-synchronous orbits and within geostationary orbits. The active debris removal (ADR) application poses new and challenging requirements on: first, the new required Guidance, Navigation and Control (GNC) technologies and, second, how to validate these new technologies before being applied in real missions. There is no doubt about the strong safety and collision risk aspects affecting the real operational ADR missions. But it shall be considered that even ADR demonstration missions will be affected by significant risk of collision during the demonstration, and that the ADR GNC systems/technologies to be used shall be well mature before using/demonstrating them in space. Specific and dedicated on-ground validation approaches, techniques and facilities are mandatory. The different ADR techniques can be roughly catalogued in three main groups (rigid capture, non-rigid capture and contactless). All of them have a strong impact on the GNC system of the active vehicle during the capture/proximity phase and, particularly, during the active vehicle/debris combo control phase after capture and during the de-orbiting phase. The main operational phases on an ADR scenario are: (1) ground controlled phase (ADR vehicle and debris are far), (2) fine orbit synchronization phase (ADR vehicle to reach debris ±V-bar), (3) short range phase (along track distance reduction till 10-100 s of metres), (4) terminal approach/capture phase and (5) de-orbiting. While phases 1-3 are somehow conventional and already addressed in detail during past/on-going studies related to rendezvous and/or formation flying, phases 4-5 are very specific and not mature in terms of GNC needed technologies and HW equipment. GMV is currently performing different internal activities and ESA studies/developments related to ADR mission, GNC and

Control of trunk motion following sudden stop perturbations during cart pushing.

Science.gov (United States)

Lee, Yun-Ju; Hoozemans, Marco J M; van Dieën, Jaap H

2011-01-04

External perturbations during pushing tasks have been suggested to be a risk factor for low-back symptoms. An experiment was designed to investigate whether self-induced and externally induced sudden stops while pushing a high inertia cart influence trunk motions, and how flexor and extensor muscles counteract these perturbations. Twelve healthy male participants pushed a 200 kg cart at shoulder height and hip height. Pushing while walking was compared to situations in which participants had to stop the cart suddenly (self-induced stop) or in which the wheels of the cart were unexpectedly blocked (externally induced stop). For the perturbed conditions, the peak values and the maximum changes from the reference condition (pushing while walking) of the external moment at L5/S1, trunk inclination and electromyographic amplitudes of trunk muscles were determined. In the self-induced stop, a voluntary trunk extension occurred. Initial responses in both stops consisted of flexor and extensor muscle cocontraction. In self-induced stops this was followed by sustained extensor activity. In the externally induced stops, an external extension moment caused a decrease in trunk inclination. The opposite directions of the internal moment and trunk motion in the externally induced stop while pushing at shoulder height may indicate insufficient active control of trunk posture. Consequently, sudden blocking of the wheels in pushing at shoulder height may put the low back at risk of mechanical injury. Copyright © 2010 Elsevier Ltd. All rights reserved.

Why do People Stop Playing On-Line Games?

DEFF Research Database (Denmark)

Sudzina, Frantisek; Razmerita, Liana

2012-01-01

The recent initial public offering of shares of Zynga, probably the most important on-line game provider, drew interest of potential investors but also of general public to their business model. What the most interested people learned so far is that if Zynga had not changed their accounting...... practice, they would be in red numbers for several months already. This is most likely caused by people stopping to play their games. This paper provides an estimate of what proportion of people, who played on-line games, already stopped playing them. Additionally, it analyzed the reasons why people...... stopped playing on-line games. It also compares Facebook and other on-line games....

ELectron stopping of heavy ions in a matter

International Nuclear Information System (INIS)

Akhiezer, I.A.; Davydov, L.N.

1978-01-01

The theory of heavy ion stopping by electrons in solids is analyzed with an aim to establish which physical mechanisms are of importance at different ion velocity values v. The theory is presented for deep inelastic collisions taking the main part in stopping at v > Zsub(1)sup(1/3) v 0 (z 1 is the atomic number of the ion, v 0 is the Bohr velocity). Elastic scattering (relative to the incident ion) are investigated. It is shown that the contribution from these processes to the stopping cross-section is predominant at Zsub(1)sup(1/3) v 0 > v > Zsub(1)sup(2/3) v 0

The stability of locus equation slopes across stop consonant voicing/aspiration

Science.gov (United States)

Sussman, Harvey M.; Modarresi, Golnaz

2004-05-01

The consistency of locus equation slopes as phonetic descriptors of stop place in CV sequences across voiced and voiceless aspirated stops was explored in the speech of five male speakers of American English and two male speakers of Persian. Using traditional locus equation measurement sites for F2 onsets, voiceless labial and coronal stops had significantly lower locus equation slopes relative to their voiced counterparts, whereas velars failed to show voicing differences. When locus equations were derived using F2 onsets for voiced stops that were measured closer to the stop release burst, comparable to the protocol for measuring voiceless aspirated stops, no significant effects of voicing/aspiration on locus equation slopes were observed. This methodological factor, rather than an underlying phonetic-based explanation, provides a reasonable account for the observed flatter locus equation slopes of voiceless labial and coronal stops relative to voiced cognates reported in previous studies [Molis et al., J. Acoust. Soc. Am. 95, 2925 (1994); O. Engstrand and B. Lindblom, PHONUM 4, 101-104]. [Work supported by NIH.

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

and test platform for the Orion Program. Critical spacecraft systems, re-entry and recovery systems, and launch abort systems of Orion could also be demonstrated in early test flights of the launch vehicle demo. Furthermore, an early demonstrator of this type would provide a stop-gap for retaining critical human capital and infrastructure while affording the current emerging generation of young engineers opportunity to work with and capture lessons learned from existing STS program offices and personnel, who were integral in the design and development of the Space Shuttle before these resources are no longer available. The objective of this study is to define candidate launch vehicle demonstration concepts that are based on Space Shuttle assets and determine their performance capabilities and how these demonstration vehicles could evolve to a heavy lift capability to low earth orbit.

Extrinsic Parameter Calibration for Line Scanning Cameras on Ground Vehicles with Navigation Systems Using a Calibration Pattern

Directory of Open Access Journals (Sweden)

Alexander Wendel

2017-10-01

Full Text Available Line scanning cameras, which capture only a single line of pixels, have been increasingly used in ground based mobile or robotic platforms. In applications where it is advantageous to directly georeference the camera data to world coordinates, an accurate estimate of the camera’s 6D pose is required. This paper focuses on the common case where a mobile platform is equipped with a rigidly mounted line scanning camera, whose pose is unknown, and a navigation system providing vehicle body pose estimates. We propose a novel method that estimates the camera’s pose relative to the navigation system. The approach involves imaging and manually labelling a calibration pattern with distinctly identifiable points, triangulating these points from camera and navigation system data and reprojecting them in order to compute a likelihood, which is maximised to estimate the 6D camera pose. Additionally, a Markov Chain Monte Carlo (MCMC algorithm is used to estimate the uncertainty of the offset. Tested on two different platforms, the method was able to estimate the pose to within 0.06 m/1.05 ∘ and 0.18 m/2.39 ∘ . We also propose several approaches to displaying and interpreting the 6D results in a human readable way.

A Conformal, Fully-Conservative Approach for Predicting Blast Effects on Ground Vehicles

Science.gov (United States)

2014-02-09

Government or the DoA, and shall not be used for advertising or product endorsement purposes. REFERENCES [1] Thompson, D., Luke, E., Newman III, J., Janus...of a Loading Model for Simulating Blast Mine Effects on Armoured Vehicles,” 7th International LS-DYNA Users Conference, Detroit, MI, 2002. [6

Hybrid Aerial/Rover Vehicle

Science.gov (United States)

Bachelder, Aaron

2003-01-01

A proposed instrumented robotic vehicle called an "aerover" would fly, roll along the ground, and/or float on bodies of liquid, as needed. The aerover would combine features of an aerobot (a robotic lighter-than-air balloon) and a wheeled robot of the "rover" class. An aerover would also look very much like a variant of the "beach-ball" rovers. Although the aerover was conceived for use in scientific exploration of Titan (the largest moon of the planet Saturn), the aerover concept could readily be adapted to similar uses on Earth.

The global polio eradication initiative Stop Transmission of Polio (STOP) program - 1999-2013.

Science.gov (United States)

2013-06-21

In 1988, the Global Polio Eradication Initiative (GPEI) was established through a partnership between the World Health Organization (WHO), Rotary International, CDC, and the United Nations Children's Fund (UNICEF). By 2012, the annual incidence of polio had decreased by >99%, compared with 1988, and the number of countries in which wild poliovirus (WPV) circulation has never been interrupted was reduced to three: Afghanistan, Nigeria, and Pakistan. However, because of the persistence of endemic WPV transmission and recurring outbreaks in polio-free countries after the original polio eradication target date of 2000, the World Health Assembly in 2012 declared the completion of polio eradication a programmatic emergency. A key component of GPEI is the Stop Transmission of Polio (STOP) program, which was developed and initiated by CDC with WHO in 1999 to mobilize additional human resources and technical assistance for countries affected by WPV transmission. During 1999-2013, 1,563 volunteers were identified, trained, and deployed for 2,221 assignments in 69 countries. The number of volunteers increased from 90-120 per year during 1999-2011 to 287 in 2012 and 378 in 2013, and the number of volunteer person-months in the field per year increased from 273 in 1999 to 1,456 in 2012. The STOP program has aided GPEI by strengthening the capacity of country-level immunization programs and by allowing a large cohort of volunteers to gain valuable field experience that prepares them well for subsequent work as staff members of WHO, UNICEF, and other public health agencies.

Help Stop the Flu | NIH MedlinePlus the Magazine

Science.gov (United States)

... page please turn Javascript on. Feature: Flu Shot Help Stop the Flu Past Issues / Winter 2011 Table ... CDC recommends that Americans do the following to help stop the flu: Cover nose and mouth with ...