WorldWideScience

Sample records for surface vehicle guidance

  1. A study of remote guidance and control for planetary surface vehicles.

    Science.gov (United States)

    Mastin, W. C.; Broussard, P. H., Jr.

    1973-01-01

    Description of tests that were originally conducted with the aim of extending the operational lifetime of the lunar roving vehicle beyond the period of the astronauts stay on the moon. The results obtained include the findings that a vehicle with six independently driven wheels appears to be practical, and that with proper drive motor sizing this configuration could provide redundancy as well as the ability to negotiate some crevasses and rocks.

  2. Integrated Entry Guidance for Reusable Launch Vehicle

    Institute of Scientific and Technical Information of China (English)

    NING Guo-dong; ZHANG Shu-guang; FANG Zhen-ping

    2007-01-01

    A method for the implementation of integrated three-degree-of-freedom constrained entry guidance for reusable launch vehicle is presented. Given any feasible entry conditions, terminal area energy management interface conditions, and the reference trajectory generated onboard then, the method can generate a longitudinal guidance profile rapidly, featuring linear quadratic regular method and a proportional-integral-derivative tracking law with time-varying gains, which satisfies all the entry corridor constraints and meets the requirements with high precision. Afterwards, by utilizing special features of crossrange parameter, establishing bank-reversal corridor,and determining bank-reversals according to dynamically adjusted method, the algorithm enables the lateral entry guidance system to fly a wide range of missions and provides reliable and good performance in the presence of significant aerodynamic modeling uncertainty.Fast trajectory guidance profiles and simulations with a reusable launch vehicle model for various missions and aerodynamic uncertainties are presented to demonstrate the capacity and reliability of this method.

  3. Vehicle Battery Safety Roadmap Guidance

    Energy Technology Data Exchange (ETDEWEB)

    Doughty, D. H.

    2012-10-01

    The safety of electrified vehicles with high capacity energy storage devices creates challenges that must be met to assure commercial acceptance of EVs and HEVs. High performance vehicular traction energy storage systems must be intrinsically tolerant of abusive conditions: overcharge, short circuit, crush, fire exposure, overdischarge, and mechanical shock and vibration. Fail-safe responses to these conditions must be designed into the system, at the materials and the system level, through selection of materials and safety devices that will further reduce the probability of single cell failure and preclude propagation of failure to adjacent cells. One of the most important objectives of DOE's Office of Vehicle Technologies is to support the development of lithium ion batteries that are safe and abuse tolerant in electric drive vehicles. This Roadmap analyzes battery safety and failure modes of state-of-the-art cells and batteries and makes recommendations on future investments that would further DOE's mission.

  4. Orbital maneuvering vehicle guidance, navigation and control

    Science.gov (United States)

    Huber, W. G.; Finnell, W., III

    1985-01-01

    This paper describes the Orbital Maneuvering Vehicle (OMV) concept and its intended role. It recaps the past activities leading up to the current concept and summarizes the present status and plans. The various types of missions and operating modes required by the OMV are described as the basis of the guidance, navigation and control (GN&C) requirements. The general GN&C problem is outlined with potential hardware solutions.

  5. Guidance and control for unmanned ground vehicles

    Science.gov (United States)

    Bateman, Peter J.

    1994-06-01

    Techniques for the guidance, control, and navigation of unmanned ground vehicles are described in terms of the communication bandwidth requirements for driving and control of a vehicle remote from the human operator. Modes of operation are conveniently classified as conventional teleoperation, supervisory control, and fully autonomous control. The fundamental problem of maintaining a robust non-line-of-sight communications link between the human controller and the remote vehicle is discussed, as this provides the impetus for greater autonomy in the control system and the greatest scope for innovation. While supervisory control still requires the man to be providing the primary navigational intelligence, fully autonomous operation requires that mission navigation is provided solely by on-board machine intelligence. Methods directed at achieving this performance are described using various active and passive sensing of the terrain for route navigation and obstacle detection. Emphasis is given to TV imagery and signal processing techniques for image understanding. Reference is made to the limitations of current microprocessor technology and suitable computer architectures. Some of the more recent control techniques involve the use of neural networks, fuzzy logic, and data fusion and these are discussed in the context of road following and cross country navigation. Examples of autonomous vehicle testbeds operated at various laboratories around the world are given.

  6. 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.

  7. Vehicle health management for guidance, navigation and control systems

    Science.gov (United States)

    Radke, Kathleen; Frazzini, Ron; Bursch, Paul; Wald, Jerry; Brown, Don

    1993-01-01

    The objective of the program was to architect a vehicle health management (VHM) system for space systems avionics that assures system readiness for launch vehicles and for space-based dormant vehicles. The platforms which were studied and considered for application of VHM for guidance, navigation and control (GN&C) included the Advanced Manned Launch System (AMLS), the Horizontal Landing-20/Personnel Launch System (HL-20/PLS), the Assured Crew Return Vehicle (ACRV) and the Extended Duration Orbiter (EDO). This set was selected because dormancy and/or availability requirements are driving the designs of these future systems.

  8. Three-dimensional robust diving guidance for hypersonic vehicle

    Science.gov (United States)

    Zhu, Jianwen; Liu, Luhua; Tang, Guojian; Bao, Weimin

    2016-01-01

    A novel three-dimensional robust guidance law based on H∞ filter and H∞ control is proposed to meet the constraints of the impact accuracy and the flight direction under process disturbances for the dive phase of hypersonic vehicle. Complete three-dimensional coupling relative motion equations are established and decoupled into linear ones by feedback linearization to simplify the design process of the further guidance law. Based on the linearized equations, H∞ filter is introduced to eliminate the measurement noises of line-of-sight angles and estimate the angular rates. Furthermore, H∞ robust control is well employed to design guidance law, and the filtered information is used to generate guidance commands to meet the guidance goal accurately and robustly. The simulation results of CAV-H indicate that the proposed three-dimensional equations can describe the coupling character more clearly than the traditional decoupling guidance, and the proposed guidance strategy can guide the vehicle to satisfy different multiple constraints with high accuracy and robustness.

  9. Influence of radius of cylinder HTS bulk on guidance force in a maglev vehicle system

    Science.gov (United States)

    Longcai, Zhang

    2014-07-01

    Bulk superconductors had great potential for various engineering applications, especially in a high-temperature superconducting (HTS) maglev vehicle system. In such a system, the HTS bulks were always exposed to AC external magnetic field, which was generated by the inhomogeneous surface magnetic field of the NdFeB guideway. In our previous work, it was observed that the guidance force of the YBCO bulk over the NdFeB guideway used in the HTS maglev vehicle system was decayed by the application of the AC external magnetic field. In this paper, we investigated the influence of the radius of the cylinder HTS bulk exposed to an AC magnetic field perturbation on the guidance force in the maglev vehicle system. From the results, it was found that the guidance force was stronger for the bulk with bigger radius and the guidance force decay rates of the bulks were approximately equal despite of the different radius in the maglev vehicle system. Therefore, in order to obtain higher guidance force in the maglev vehicle system, we could use the cylinder HTS bulks with the bigger radius.

  10. 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.

  11. Fault-Tolerant Vision for Vehicle Guidance in Agriculture

    DEFF Research Database (Denmark)

    Blas, Morten Rufus

    The emergence of widely available vision technologies is enabling for a wide range of automation tasks in industry and other areas. Agricultural vehicle guidance systems have benefitted from advances in 3D vision based on stereo camera technology. By automatically guiding vehicles along crops...... dropout of 3D vision, faults in classification, or other defects, redundant information should be utilized. Such information can be used to diagnose faulty behavior and to temporarily continue operation with a reduced set of sensors when faults or artifacts occur. Additional sensors include GPS receivers...... and inertial sensors. To fully utilize the possibilities in 3D vision, the system must also be able to learn and adapt to changing environments. By learning features of the environment new diagnostic relations can be generated by creating redundant feed-forward information about crop location. Also, by mapping...

  12. Impact of connected vehicle guidance information on network-wide average travel time

    Directory of Open Access Journals (Sweden)

    Jiangfeng Wang

    2016-12-01

    Full Text Available With the emergence of connected vehicle technologies, the potential positive impact of connected vehicle guidance on mobility has become a research hotspot by data exchange among vehicles, infrastructure, and mobile devices. This study is focused on micro-modeling and quantitatively evaluating the impact of connected vehicle guidance on network-wide travel time by introducing various affecting factors. To evaluate the benefits of connected vehicle guidance, a simulation architecture based on one engine is proposed representing the connected vehicle–enabled virtual world, and connected vehicle route guidance scenario is established through the development of communication agent and intelligent transportation systems agents using connected vehicle application programming interface considering the communication properties, such as path loss and transmission power. The impact of connected vehicle guidance on network-wide travel time is analyzed by comparing with non-connected vehicle guidance in response to different market penetration rate, following rate, and congestion level. The simulation results explore that average network-wide travel time in connected vehicle guidance shows a significant reduction versus that in non–connected vehicle guidance. Average network-wide travel time in connected vehicle guidance have an increase of 42.23% comparing to that in non-connected vehicle guidance, and average travel time variability (represented by the coefficient of variance increases as the travel time increases. Other vital findings include that higher penetration rate and following rate generate bigger savings of average network-wide travel time. The savings of average network-wide travel time increase from 17% to 38% according to different congestion levels, and savings of average travel time in more serious congestion have a more obvious improvement for the same penetration rate or following rate.

  13. 78 FR 17660 - Draft Guidance for E85 Flexible Fuel Vehicle Weighting Factor for Model Years 2016-2019 Vehicles...

    Science.gov (United States)

    2013-03-22

    ... AGENCY Draft Guidance for E85 Flexible Fuel Vehicle Weighting Factor for Model Years 2016-2019 Vehicles... determined by weighting the gasoline and E85 values of the model together using the specified factor (see 40... that EPA provide a weighting factor to use for 2016 and later model year vehicles. EPA has assessed the...

  14. Video Guidance Sensor for Surface Mobility Operations

    Science.gov (United States)

    Fernandez, Kenneth R.; Fischer, Richard; Bryan, Thomas; Howell, Joe; Howard, Ricky; Peters, Bruce

    2008-01-01

    Robotic systems and surface mobility will play an increased role in future exploration missions. Unlike the LRV during Apollo era which was an astronaut piloted vehicle future systems will include teleoperated and semi-autonomous operations. The tasks given to these vehicles will run the range from infrastructure maintenance, ISRU, and construction to name a few. A common task that may be performed would be the retrieval and deployment of trailer mounted equipment. Operational scenarios may require these operations to be performed remotely via a teleoperated mode,or semi-autonomously. This presentation describes the on-going project to adapt the Automated Rendezvous and Capture (AR&C) sensor developed at the Marshall Space Flight Center for use in an automated trailer pick-up and deployment operation. The sensor which has been successfully demonstrated on-orbit has been mounted on an iRobot/John Deere RGATOR autonomous vehicle for this demonstration which will be completed in the March 2008 time-frame.

  15. Surface properties-vehicle interaction

    Science.gov (United States)

    Huft, D. L.; Her, I.; Agrawal, S. K.; Zimmer, R. A.; Bester, C. J.

    Several topics related to the surface properties of aircraft runways are discussed. The South Dakota profilometer; development of a data acquisition method for noncontact pavement macrotexture measurement; the traction of an aircraft tire on grooved and porous asphaltic concrete; holes in the pavements; the effect of pavement type and condition on the fuel consumption of vehicles; the traction loss of a suspended tire on a sinusoidal road; the effect of vehicle and driver characteristics on the psychological evaluation of road roughness; the correlation of subjective panel ratings of pavement ride quality with profilometer-derived measures of pavement roughness; a microprocessor-based noncontact distance measuring control system, and, the representation of pavement surface topography in predicting runoff depths and hydroplaning potential are discussed.

  16. Surface properties-vehicle interaction

    Energy Technology Data Exchange (ETDEWEB)

    Huft, D.L.; Her, I.; Agrawal, S.K.; Zimmer, R.A.; Bester, C.J.

    1984-01-01

    The 10 papers in the report deal with the following areas: South Dakota profilometer; development of a data-acquisition method for noncontact pavement macrotexture measurement; traction of an aircraft tire on grooved and porous asphaltic concrete; holes in the pavement-an assessment of their influence on safety; effect of pavement type and condition on the fuel consumption of vehicles; traction loss of a suspended tire on a sinusoidal road; effect of vehicle and driver characteristics on the psychological evaluation of road roughness; correlation of subjective panel ratings of pavement ride quality with profilometer-derived measures of pavement roughness; microprocessor-based noncontact distance measuring control system; and, representation of pavement-surface topography in predicting runoff depths and hydroplaning potential.

  17. Concept for a common operational picture in a guidance vehicle

    Science.gov (United States)

    Wagner, Boris; Eck, Ralf; Maier, Sebastian

    2017-05-01

    A Common Operational Picture (COP) shows many operational aspects in coded form inside a geodata representation like a map. For building this picture, many specialized groups produce information. Beside the operating forces these are intelligences, logistics, or the own leaders planning group. Operations in which a COP is used typically are disaster management or military actions. An existing software for Interactive Visualization of Integrated Geodata runs on Tablet-PCs, PCs, Digital Map Tables and video walls. It is already used by the Deutsche Führungsakademie (military academy) for the education of staff officers. German civil disaster management agency decided to use the Digital Map Table for their intelligence analysis. In a mobile scenario, however, novel requirements have to be taken into account to adapt the software to the new environment. This paper investigates these requirements as well as the possible adaptions to provide a COP across multiple players on the go. When acting together, the groups do this in a widespread manner. They are physically spread and they use a variety of software and hardware to produce their contribution. This requires hardware to be ruggedized, mobile, and to support a variety of interfaces. The limited bandwidth in such a setting poses the main challenge for the software, which has to synchronize exchanging a minimum of information. Especially for mobile participants, a solution is planned that scales the amount of data (maps/intelligence data) to the available equipment, the upcoming mission, and the underlying theatre. Special focus is laid on a guidance vehicle leading a convoy.

  18. Working together on automated vehicle guidance AVG : preliminary business plan, abridged version.

    NARCIS (Netherlands)

    Awareness (ed.)

    1998-01-01

    This plan describes the questions which will have to be answered in the short term, and the action which need to be taken in a phased and structured manner to gain insight into the potential of automated vehicle guidance (AVG).

  19. Variable structure guidance law for attacking surface maneuver targets

    Institute of Scientific and Technical Information of China (English)

    Han Yanhua; Xu Bo

    2008-01-01

    The characteristics of surface maneuver targets are analyzed and a 3-D relative motion model for missiles and targets is established. A variable structure guidance law is designed considering the characteristics of targets. In the guidance law, the distance between missiles and targets as well as the missile-target relative velocity are all substituted by estimation values. The estimation errors, the target's velocity, and the maneuver acceleration are all treated as bounded disturbance. The guidance law proposed can be implemented conveniently in engineering with little target information. The performance of the guidance system is analyzed theoretically and the numerical simulation result shows the effectiveness of the guidance law.

  20. A guidance and control algorithm for scent tracking micro-robotic vehicle swarms

    Energy Technology Data Exchange (ETDEWEB)

    Dohner, J.L. [Sandia National Labs., Albuquerque, NM (United States). Structural Dynamics Dept.

    1998-03-01

    Cooperative micro-robotic scent tracking vehicles are designed to collectively sniff out locations of high scent concentrations in unknown, geometrically complex environments. These vehicles are programmed with guidance and control algorithms that allow inter cooperation among vehicles. In this paper a cooperative guidance and control algorithm for scent tracking micro-robotic vehicles is presented. This algorithm is comprised of a sensory compensation sub-algorithm using point source cancellation, a guidance sub-algorithm using gradient descent tracking, and a control sub-algorithm using proportional feedback. The concepts of social rank and point source cancellation are new concepts introduced within. Simulation results for cooperative vehicles swarms are given. Limitations are discussed.

  1. Vision-based bio-inspired guidance law for small aerial vehicle

    Institute of Scientific and Technical Information of China (English)

    Wang Zhengjie; Huang Weilin; Yan Yonghong

    2015-01-01

    During predation, a flying insect can form a stealth flight path. This behavior is called motion camouflage. Based on the study results of this behavior, the perception and neurology of flying insects, a novel bio-inspired guidance law is proposed for the terminal guidance for small aer-ial vehicle with charge-coupled device imaging seekers. The kinematics relationship between a small aerial vehicle and target is analyzed, and a two-dimensional guidance law model is established by using artificial neural networks. To compare with the proportional guidance law, the numerical sim-ulations are carried out in the vertical plane and in the horizontal plane respectively. The simulation results show that the ballistic of the small aerial vehicle is straighter and the normal acceleration is smaller by using the bio-inspired guidance law than by using the proportional guidance law. That is to say, the bio-inspired guidance law just uses the information of the target from the imaging seeker, but the performance of it can be better than that of the proportional guidance law.

  2. Vision-based bio-inspired guidance law for small aerial vehicle

    Directory of Open Access Journals (Sweden)

    Wang Zhengjie

    2015-02-01

    Full Text Available During predation, a flying insect can form a stealth flight path. This behavior is called motion camouflage. Based on the study results of this behavior, the perception and neurology of flying insects, a novel bio-inspired guidance law is proposed for the terminal guidance for small aerial vehicle with charge-coupled device imaging seekers. The kinematics relationship between a small aerial vehicle and target is analyzed, and a two-dimensional guidance law model is established by using artificial neural networks. To compare with the proportional guidance law, the numerical simulations are carried out in the vertical plane and in the horizontal plane respectively. The simulation results show that the ballistic of the small aerial vehicle is straighter and the normal acceleration is smaller by using the bio-inspired guidance law than by using the proportional guidance law. That is to say, the bio-inspired guidance law just uses the information of the target from the imaging seeker, but the performance of it can be better than that of the proportional guidance law.

  3. Optimal guidance for reentry vehicles based on indirect Legendre pseudospectral method

    Science.gov (United States)

    Tian, Bailing; Zong, Qun

    2011-04-01

    Development of a feasible guidance scheme for reentry vehicles is a challenge because of its significant nonlinearity and multi-constraints. A method for the implementation of three-degree-of-freedom guidance for constrained reentry vehicle is presented in the paper. First, the constrained trajectory is generated by Legendre pseudospectral method (LPM) and then the feasibily of the trajectory is validated. Based on the obtained reference trajectory, the guidance problem is converted into a trajectory state regulation problem which is a linear time varying system. A robust state feedback guidance law is generated in real time using indirect Legendre pseudospectral feedback method. Finally, simulation results illustrate that the overall guidance scheme can lead to a very accurately controlled flight with all the constraints satisfied even in the presence of initial state uncertainty.

  4. A Multiconstrained Ascent Guidance Method for Solid Rocket-Powered Launch Vehicles

    Directory of Open Access Journals (Sweden)

    Si-Yuan Chen

    2016-01-01

    Full Text Available This study proposes a multiconstrained ascent guidance method for a solid rocket-powered launch vehicle, which uses a hypersonic glide vehicle (HGV as payload and shuts off by fuel exhaustion. First, pseudospectral method is used to analyze the two-stage launch vehicle ascent trajectory with different rocket ignition modes. Then, constraints, such as terminal height, velocity, flight path angle, and angle of attack, are converted into the constraints within height-time profile according to the second-stage rocket flight characteristics. The closed-loop guidance method is inferred by different spline curves given the different terminal constraints. Afterwards, a thrust bias energy management strategy is proposed to waste the excess energy of the solid rocket. Finally, the proposed method is verified through nominal and dispersion simulations. The simulation results show excellent applicability and robustness of this method, which can provide a valuable reference for the ascent guidance of solid rocket-powered launch vehicles.

  5. Vision-GPS Fusion for Guidance of an Autonomous Vehicle in Row Crops

    DEFF Research Database (Denmark)

    Bak, Thomas

    2001-01-01

    This paper presents a real-time localization system for an autonomous vehicle passing through 0.25 m wide crop rows at 6 km/h. Localization is achieved by fusion of mea-surements from a row guidance sensor and a GPS receiver. Conventional agricultural practice applies inputs such as herbicide...... at a constant rate ignoring the spatial variability in weed, soil, and crop. Sensing with a guided vehicle allow cost effective mapping of field variability and inputs may be adjusted accordingly. Essential to such a vehicle is real-time localization. GPS allow precise absolute sensing but it is not practical...... to guide the vehicle relative to the crop rows on an absolute coordinate. A row guidance sensor is therefore included to sense the position relative to the rows. The vehicle path in the field is re-planned online in order to allow for crop row irregularities sensed by the row sensor. The path generation...

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  7. Vision-GPS Fusion for Guidance of an Autonomous Vehicle in Row Crops

    DEFF Research Database (Denmark)

    Bak, Thomas

    2001-01-01

    at a constant rate ignoring the spatial variability in weed, soil, and crop. Sensing with a guided vehicle allow cost effective mapping of field variability and inputs may be adjusted accordingly. Essential to such a vehicle is real-time localization. GPS allow precise absolute sensing but it is not practical...... to guide the vehicle relative to the crop rows on an absolute coordinate. A row guidance sensor is therefore included to sense the position relative to the rows. The vehicle path in the field is re-planned online in order to allow for crop row irregularities sensed by the row sensor. The path generation...

  8. A guidance and navigation system for continuous low thrust vehicles. M.S. Thesis

    Science.gov (United States)

    Tse, C. J. C.

    1973-01-01

    A midcourse guidance and navigation system for continuous low thrust vehicles is described. A set of orbit elements, known as the equinoctial elements, are selected as the state variables. The uncertainties are modelled statistically by random vector and stochastic processes. The motion of the vehicle and the measurements are described by nonlinear stochastic differential and difference equations respectively. A minimum time nominal trajectory is defined and the equation of motion and the measurement equation are linearized about this nominal trajectory. An exponential cost criterion is constructed and a linear feedback guidance law is derived to control the thrusting direction of the engine. Using this guidance law, the vehicle will fly in a trajectory neighboring the nominal trajectory. The extended Kalman filter is used for state estimation. Finally a short mission using this system is simulated. The results indicate that this system is very efficient for short missions.

  9. Atmospheric Reentry Dispersion Correction Ascent Phase Guidance for a Generic Reentry Vehicle

    Directory of Open Access Journals (Sweden)

    Avinash Chander

    2013-05-01

    Full Text Available Launch vehicle explicit guidance mechanism depends on the estimation of the desired burnout conditions and driving the vehicle to achieve these conditions. The accuracy of the vehicle at the target point depends on how tightly these conditions are achieved and what is the strategy used to define the trajectory. It has been observed inthe literature that most of the guidance mechanisms during reentry use vacuum guidance equations that is durin greentry the atmospheric effects are not considered. In order to achieve minimum miss distance at the target point theat mospheric effects are to be considered during the guided phase and appropriate corrections should be executed,otherwise depending on the reentry flight path angle and ballistic coefficient the errors can be as high as tens of nautical miles. In this paper, the authors develop a novel approach to these vacuum guided launch vehicle problems.The paper elaborates how to calculate a prior the reentry dispersion during the ascent phase guidance and provide guidance corrections such that the terminal conditions are achieved with higher accuracy.Defence Science Journal, 2013, 63(3, pp.233-241, DOI:http://dx.doi.org/10.14429/dsj.63.3733

  10. Structuring automated vehicle guidance knowledge in The Netherlands

    NARCIS (Netherlands)

    Hoedemaeker, M.; Bastiaensen, E.G.H.J.; Zwaneveld, P.J.

    2000-01-01

    This paper describes the set-up of a AVG knowledge database from the AVV Transport Research Centre from the Dutch Ministry of Transport, Public Works and Water Management. The database provides a categorised overview of all research performed in The Netherlands in the area of Automatic Vehicle Guida

  11. Simulating an underwater vehicle self-correcting guidance system with Simulink

    Institute of Scientific and Technical Information of China (English)

    FAN Hui; ZHANGYu-wen; LI Wen-zhe

    2008-01-01

    Underwater vehicles have already adopted self-correcting directional guidance algorithms based on multi-beam self-guidance systems, not waiting for research to determine the most effective algorithms. The main challenges facing research on these guidance systems have been effective modeling of the guidance algorithm and a means to analyze the simulation results. A simulation structure based on Simulink that dealt with both issues was proposed. Initially, a mathematical model of relative motion between the vehicle and the target was developed, which was then encapsulated as a subsystem. Next,steps for constructing a model of the self-correcting guidance algorithm based on the Stateflow module were examined in detail. Finally, a 3-D model of the vehicle and target was created in VRML, and by processing mathematical results, the model was shown moving in a visual environment. This process gives more intuitive results for analyzing the simulation. The results showed that the simulation structure performs well. The simulation program heavily used modularization and encapsulation, so has broad applicability to simulations of other dynamic systems.

  12. Closed-loop endo-atmospheric ascent guidance for reusable launch vehicle

    Science.gov (United States)

    Sun, Hongsheng

    This dissertation focuses on the development of a closed-loop endo-atmospheric ascent guidance algorithm for the 2nd generation reusable launch vehicle. Special attention has been given to the issues that impact on viability, complexity and reliability in on-board implementation. The algorithm is called once every guidance update cycle to recalculate the optimal solution based on the current flight condition, taking into account atmospheric effects and path constraints. This is different from traditional ascent guidance algorithms which operate in a simple open-loop mode inside atmosphere, and later switch to a closed-loop vacuum ascent guidance scheme. The classical finite difference method is shown to be well suited for fast solution of the constrained optimal three-dimensional ascent problem. The initial guesses for the solutions are generated using an analytical vacuum optimal ascent guidance algorithm. Homotopy method is employed to gradually introduce the aerodynamic forces to generate the optimal solution from the optimal vacuum solution. The vehicle chosen for this study is the Lockheed Martin X-33 lifting-body reusable launch vehicle. To verify the algorithm presented in this dissertation, a series of open-loop and closed-loop tests are performed for three different missions. Wind effects are also studied in the closed-loop simulations. For comparison, the solutions for the same missions are also obtained by two independent optimization softwares. The results clearly establish the feasibility of closed-loop endo-atmospheric ascent guidance of rocket-powered launch vehicles. ATO cases are also tested to assess the adaptability of the algorithm to autonomously incorporate the abort modes.

  13. Application of Closed Loop Optimal Guidance for a Constant Thrust Space Vehicle

    Science.gov (United States)

    Rezaei Darestani, Mahdy; Abbasi Mahale, Mahdi

    2016-01-01

    This research presents derivation and implementation of the explicit guidance problem to steer a space vehicle into exo atmospheric phase of flight to develop three-dimensional optimal trajectory. The proposed guidance algorithm is in association with continuous powered flight of the space vehicle in ascent manoeuvre. Stability, accuracy and simplicity of this approach are the improved developments in comparison with the IGM approach. This algorithm uses the calculus of variation method for the two boundary-value injection problem to generate an optimal trajectory of space vehicle with online generation of steering command to inject to any desired orbit. Here the end conditions have been determined as the orbital height, inclination and eccentricity where the initial conditions are fixed. The simulation results are considered which shows the accuracy and simplicity of this method to reach to the desired orbit in minimum fuel.

  14. Guidance of Autonomous Amphibious Vehicles for Flood Rescue Support

    Directory of Open Access Journals (Sweden)

    Shankarachary Ragi

    2013-01-01

    Full Text Available We develop a path-planning algorithm to guide autonomous amphibious vehicles (AAVs for flood rescue support missions. Specifically, we develop an algorithm to control multiple AAVs to reach/rescue multiple victims (also called targets in a flood scenario in 2D, where the flood water flows across the scene and the targets move (drifted by the flood water along the flood stream. A target is said to be rescued if an AAV lies within a circular region of a certain radius around the target. The goal is to control the AAVs such that each target gets rescued while optimizing a certain performance objective. The algorithm design is based on the theory of partially observable Markov decision process (POMDP. In practice, POMDP problems are hard to solve exactly, so we use an approximation method called nominal belief-state optimization (NBO. We compare the performance of the NBO approach with a greedy approach.

  15. Nonlinear Adaptive Control and Guidance for Unstart Recovery for a Generic Hypersonic Vehicle

    Science.gov (United States)

    Gunbatar, Yakup

    This work presents the development of an integrated flight controller for a generic model of a hypersonic air-breathing vehicle. The flight control architecture comprises a guidance and trajectory planning module and a nonlinear inner-loop adaptive controller. The emphasis of the controller design is on achieving stable tracking of suitable reference trajectories in the presence of a specific engine fault (inlet unstart), in which sudden and drastic changes in the vehicle aerodynamics and engine performance occur. First, the equations of motion of the vehicle for a rigid body model, taking the rotation of the Earth into account, is provided. Aerodynamic forces and moments and engine data are provided in lookup-table format. This comprehensive model is used for simulations and verification of the control strategies. Then, a simplified control-oriented model is developed for the purpose of control design and stability analysis. The design of the guidance and nonlinear adaptive control algorithms is first carried out on a longitudinal version of the vehicle dynamics. The design is verified in a simulation study aiming at testing the robustness of the inner-loop controller under significant model uncertainty and engine failures. At the same time, the guidance system provides reference trajectories to maximize the vehicle's endurance, which is cast as an optimal control problem. The design is then extended to tackle the significantly more challenging case of the 6-degree-of-freedom (6-DOF) vehicle dynamics. For the full 6-DOF case, the adaptive nonlinear flight controller is tested on more challenging maneuvers, where values of the flight path and bank angles exceed the nominal range defined for the vehicle. Simulation studies show stable operation of the closed-loop system in nominal operating conditions, unstart conditions, and during transition from sustained scramjet propulsion to engine failure mode.

  16. Design and Implementation of GPS Vehicle Navigation and Guidance System

    Institute of Scientific and Technical Information of China (English)

    Bing-zhong REN; Wen-huan KONG

    2010-01-01

    -The urban traffic infomation management has become an important way of solving traffic jam of cities.With the wider use of the third generation of mobile communication(3G)networks,urban information management based on 3G will be a central issue of application.The paper designs a framework of Global Positioning System(GPS)vehicle navigating and guiding system using 3G mobile network and Global Information System(CIS)electronic map according to moving objects.It discusses moving object' s time-space attributes which will be described by a five-field and a directed graph.It analyzes the GPS mobile appararus's software functions and hardware And it improves the function of GPS mobile apparatus which provide the guiding function utilizing the shared information of traffic.The navigation based on the shortest path algorithm is been advanced to one based on the real-time traffic flow of moving objects,which help people travelling on roads mote convenietly.

  17. Influence of Critical Current Density on Guidance Force Decay of HTS Bulk Exposed to AC Magnetic Field Perturbation in a Maglev Vehicle System

    Science.gov (United States)

    Longcai, Zhang; Jianguo, Kong

    2012-07-01

    Superconducting maglev vehicle is one of the most promising applications of HTS bulks. In such a system, the HTS bulks are always exposed to AC external magnetic field, which is generated by the inhomogeneous surface magnetic field of the NdFeB guideway. In our previous work, we studied the guidance force decay of the YBCO bulk over the NdFdB guideway used in the High-temperature superconducting maglev vehicle system with the application of the AC external magnetic field, and calculated the guidance force decay as a function of time based on an analytic model. In this paper, we investigated the influence of the critical current density on the guidance force decay of HTS bulk exposed to AC field perturbation in the maglev vehicle system and try to adopt a method to suppress the decay. From the results, it was found that the guidance force decay rate was higher for the bulk with lower critical current density. Therefore, we could suppress the guidance force decay of HTS bulk exposed to AC external magnetic field perturbation in the maglev vehicle system by improving critical current density of the bulk.

  18. The Role of Guidance, Navigation, and Control in Hypersonic Vehicle Multidisciplinary Design and Optimization

    Science.gov (United States)

    Ouzts, Peter J.; Soloway, Donald I.; Moerder, Daniel D.; Wolpert, David H.; Benavides, Jose Victor

    2009-01-01

    Airbreathing hypersonic systems offer distinct performance advantages over rocket-based systems for space access vehicles. However, these performance advantages are dependent upon advances in current state-of-the-art technologies in many areas such as ram/scramjet propulsion integration, high temperature materials, aero-elastic structures, thermal protection systems, transition to hypersonics and hypersonic control elements within the framework of complex physics and new design methods. The complex interactions between elements of an airbreathing hypersonic vehicle represent a new paradigm in vehicle design to achieve the optimal performance necessary to meet space access mission objectives. In the past, guidance, navigation, and control (GNC) analysis often follows completion of the vehicle conceptual design process. Individual component groups design subsystems which are then integrated into a vehicle configuration. GNC is presented the task of developing control approaches to meet vehicle performance objectives given that configuration. This approach may be sufficient for vehicles where significant performance margins exist. However, for higher performance vehicles engaging the GNC discipline too late in the design cycle has been costly. For example, the X-29 experimental flight vehicle was built as a technology demonstrator. One of the many technologies to be demonstrated was the use of light-weight material composites for structural components. The use of light-weight materials increased the flexibility of the X- 29 beyond that of conventional metal alloy constructed aircraft. This effect was not considered when the vehicle control system was designed and built. The impact of this is that the control system did not have enough control authority to compensate for the effects of the first fundamental structural mode of the vehicle. As a result, the resulting pitch rate response of the vehicle was below specification and no post-design changes could recover the

  19. Neighboring optimum guidance of a Space-Shuttle-orbiter-type vehicle

    Science.gov (United States)

    Pesch, H. J.

    1980-10-01

    A new numerical method for the computation of optimal flight path corrections is used to study the guidance behavior of a Space-Shuttle-orbiter-type vehicle. This method is based on a modification of well-known neighboring optimum feedback control schemes and includes a specialization of the multiple shooting algorithm for the solution of two-point boundary value problems. With the Space Shuttle, atmospheric entry by lifting vehicles capable of considerable lateral range will become of practical interest. Increased range capacity will allow more frequent returns from orbit. After investigating the neighboring optimum guidance of the Shuttle, controllability regions are obtained, which characterize the range of the successfully correctable deviations. Enlargements and contractions of this multidimensional tube surrounding the reference trajectory correspond in some sense to the oscillatory behavior of the flight path typical for range optimal nonquasisteady glide. Guidance rules are established indicating the best times for the correction of realistic deviations of each flight coordinate to preserve optimality. The efficiency of the guidance method is demonstrated by studying the size of those deviations which can be compensated during the flight in a time interval small enough for real-time computations on modern onboard computers.

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

    Directory of Open Access Journals (Sweden)

    Xing Liu

    2017-05-01

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

  1. A robust and high precision optimal explicit guidance scheme for solid motor propelled launch vehicles with thrust and drag uncertainty

    Science.gov (United States)

    Maity, Arnab; Padhi, Radhakant; Mallaram, Sanjeev; Mallikarjuna Rao, G.; Manickavasagam, M.

    2016-10-01

    A new nonlinear optimal and explicit guidance law is presented in this paper for launch vehicles propelled by solid motors. It can ensure very high terminal precision despite not having the exact knowledge of the thrust-time curve apriori. This was motivated from using it for a carrier launch vehicle in a hypersonic mission, which demands an extremely narrow terminal accuracy window for the launch vehicle for successful initiation of operation of the hypersonic vehicle. The proposed explicit guidance scheme, which computes the optimal guidance command online, ensures the required stringent final conditions with high precision at the injection point. A key feature of the proposed guidance law is an innovative extension of the recently developed model predictive static programming guidance with flexible final time. A penalty function approach is also followed to meet the input and output inequality constraints throughout the vehicle trajectory. In this paper, the guidance law has been successfully validated from nonlinear six degree-of-freedom simulation studies by designing an inner-loop autopilot as well, which enhances confidence of its usefulness significantly. In addition to excellent nominal results, the proposed guidance has been found to have good robustness for perturbed cases as well.

  2. Description of the primary flight display and flight guidance system logic in the NASA B-737 transport systems research vehicle

    Science.gov (United States)

    Knox, Charles E.

    1990-01-01

    A primary flight display format was integrated with the flight guidance and control system logic in support of various flight tests conducted with the NASA Transport Systems Research Vehicle B-737-100 airplane. The functional operation of the flight guidance mode control panel and the corresponding primary flight display formats are presented.

  3. Subsea Cable Tracking by Autonomous Underwater Vehicle with Magnetic Sensing Guidance.

    Science.gov (United States)

    Xiang, Xianbo; Yu, Caoyang; Niu, Zemin; Zhang, Qin

    2016-08-20

    The changes of the seabed environment caused by a natural disaster or human activities dramatically affect the life span of the subsea buried cable. It is essential to track the cable route in order to inspect the condition of the buried cable and protect its surviving seabed environment. The magnetic sensor is instrumental in guiding the remotely-operated vehicle (ROV) to track and inspect the buried cable underseas. In this paper, a novel framework integrating the underwater cable localization method with the magnetic guidance and control algorithm is proposed, in order to enable the automatic cable tracking by a three-degrees-of-freedom (3-DOF) under-actuated autonomous underwater vehicle (AUV) without human beings in the loop. The work relies on the passive magnetic sensing method to localize the subsea cable by using two tri-axial magnetometers, and a new analytic formulation is presented to compute the heading deviation, horizontal offset and buried depth of the cable. With the magnetic localization, the cable tracking and inspection mission is elaborately constructed as a straight-line path following control problem in the horizontal plane. A dedicated magnetic line-of-sight (LOS) guidance is built based on the relative geometric relationship between the vehicle and the cable, and the feedback linearizing technique is adopted to design a simplified cable tracking controller considering the side-slip effects, such that the under-actuated vehicle is able to move towards the subsea cable and then inspect its buried environment, which further guides the environmental protection of the cable by setting prohibited fishing/anchoring zones and increasing the buried depth. Finally, numerical simulation results show the effectiveness of the proposed magnetic guidance and control algorithm on the envisioned subsea cable tracking and the potential protection of the seabed environment along the cable route.

  4. Subsea Cable Tracking by Autonomous Underwater Vehicle with Magnetic Sensing Guidance

    Directory of Open Access Journals (Sweden)

    Xianbo Xiang

    2016-08-01

    Full Text Available The changes of the seabed environment caused by a natural disaster or human activities dramatically affect the life span of the subsea buried cable. It is essential to track the cable route in order to inspect the condition of the buried cable and protect its surviving seabed environment. The magnetic sensor is instrumental in guiding the remotely-operated vehicle (ROV to track and inspect the buried cable underseas. In this paper, a novel framework integrating the underwater cable localization method with the magnetic guidance and control algorithm is proposed, in order to enable the automatic cable tracking by a three-degrees-of-freedom (3-DOF under-actuated autonomous underwater vehicle (AUV without human beings in the loop. The work relies on the passive magnetic sensing method to localize the subsea cable by using two tri-axial magnetometers, and a new analytic formulation is presented to compute the heading deviation, horizontal offset and buried depth of the cable. With the magnetic localization, the cable tracking and inspection mission is elaborately constructed as a straight-line path following control problem in the horizontal plane. A dedicated magnetic line-of-sight (LOS guidance is built based on the relative geometric relationship between the vehicle and the cable, and the feedback linearizing technique is adopted to design a simplified cable tracking controller considering the side-slip effects, such that the under-actuated vehicle is able to move towards the subsea cable and then inspect its buried environment, which further guides the environmental protection of the cable by setting prohibited fishing/anchoring zones and increasing the buried depth. Finally, numerical simulation results show the effectiveness of the proposed magnetic guidance and control algorithm on the envisioned subsea cable tracking and the potential protection of the seabed environment along the cable route.

  5. Adaptive guidance law design based on characteristic model for reentry vehicles

    Institute of Scientific and Technical Information of China (English)

    YANG JunChun; HU Jun; NI MaoLin

    2008-01-01

    In this paper an adaptive guidance law based on the characteristic model is designed to track a reference drag acceleration for reentry vehicles like the Shuttle. The characteristic modeling method of linear constant systems is extended for single-input and single-output (SlSO) linear time-varying systems so that the characteristic model can be established for reentry vehicles. A new nonlinear differential golden-section adaptive control law is presented. When the coefficients belong to a bounded closed convex set and their rate of change meets some constraints, the uniformly asymptotic stability of the nonlinear differential golden-section adaptive control system is proved. The tracking control law, the nonlinear differential golden-section control law, and the revised logical integral control law are integrated to design an adaptive guidance law based on the characteristic model. This guidance law overcomes the disadvantage of the feedback linearization method which needs the precise model. Simulation results show that the proposed method has better performance of tracking the reference drag acceleration than the feedback linearization one.

  6. Modeling Travel Time Reliability of Road Network Considering Connected Vehicle Guidance Characteristics Indexes

    Directory of Open Access Journals (Sweden)

    Jiangfeng Wang

    2017-01-01

    Full Text Available Travel time reliability (TTR is one of the important indexes for effectively evaluating the performance of road network, and TTR can effectively be improved using the real-time traffic guidance information. Compared with traditional traffic guidance, connected vehicle (CV guidance can provide travelers with more timely and accurate travel information, which can further improve the travel efficiency of road network. Five CV characteristics indexes are selected as explanatory variables including the Congestion Level (CL, Penetration Rate (PR, Compliance Rate (CR, release Delay Time (DT, and Following Rate (FR. Based on the five explanatory variables, a TTR model is proposed using the multilogistic regression method, and the prediction accuracy and the impact of characteristics indexes on TTR are analyzed using a CV guidance scenario. The simulation results indicate that 80% of the RMSE is concentrated within the interval of 0 to 0.0412. The correlation analysis of characteristics indexes shows that the influence of CL, PR, CR, and DT on the TTR is significant. PR and CR have a positive effect on TTR, and the average improvement rate is about 77.03% and 73.20% with the increase of PR and CR, respectively, while CL and DT have a negative effect on TTR, and TTR decreases by 31.21% with the increase of DT from 0 to 180 s.

  7. 78 FR 41852 - Hours of Service for Commercial Motor Vehicle Drivers; Regulatory Guidance Concerning Off-Duty Time

    Science.gov (United States)

    2013-07-12

    ... commercial motor vehicle programs and safety regulation. Background On April 4, 1997 (62 FR 16370), the... FR 16422): Question 2: What conditions must be met for a Commercial Motor Vehicle (CMV) driver to... Drivers; Regulatory Guidance Concerning Off-Duty Time AGENCY: Federal Motor Carrier Safety...

  8. Advanced Guidance and Control Methods for Reusable Launch Vehicles: Test Results

    Science.gov (United States)

    Hanson, John M.; Jones, Robert E.; Krupp, Don R.; Fogle, Frank R. (Technical Monitor)

    2002-01-01

    There are a number of approaches to advanced guidance and control (AG&C) that have the potential for achieving the goals of significantly increasing reusable launch vehicle (RLV) safety/reliability and reducing the cost. In this paper, we examine some of these methods and compare the results. We briefly introduce the various methods under test, list the test cases used to demonstrate that the desired results are achieved, show an automated test scoring method that greatly reduces the evaluation effort required, and display results of the tests. Results are shown for the algorithms that have entered testing so far.

  9. A guidance and navigation system for continuous low-thrust vehicles. M.S. Thesis

    Science.gov (United States)

    Jack-Chingtse, C.

    1973-01-01

    A midcourse guidance and navigation system for continuous low thrust vehicles was developed. The equinoctial elements are the state variables. Uncertainties are modelled statistically by random vector and stochastic processes. The motion of the vehicle and the measurements are described by nonlinear stochastic differential and difference equations respectively. A minimum time trajectory is defined; equations of motion and measurements are linearized about this trajectory. An exponential cost criterion is constructed and a linear feedback quidance law is derived. An extended Kalman filter is used for state estimation. A short mission using this system is simulated. It is indicated that this system is efficient for short missions, but longer missions require accurate trajectory and ground based measurements.

  10. Guidance and control analysis of the entry of a lifting body personnel launch vehicle

    Science.gov (United States)

    Powell, Richard W.; Cruz, Christopher I.

    1991-01-01

    NASA is currently involved in definition studies of a Personnel Launch System (PLS) that could be used to transport people to and from low-earth orbit. This vehicle would serve both to complement the Space Shuttle and to provide alternative access to space in the event the Space Shuttle fleet were unavailable for a prolonged period. The PLS would consist of a manned spacecraft launched by an expendable vehicle, e.g., Titan 4. One promising candidate for the manned component of the PLS is the NASA Langley Research Center HL-20 lifting body. Many studies are currently underway to assess this vehicle, and one of the main areas of study is the development of the capability to successfully enter, glide to the landing site, and land. To provide this capability, guidance and control algorithms have been developed, incorporated into a six-degree-of-freedom simulation, and evaluation in the presence of off-nominal atmospheric conditions, consisting of both density variations and steady-state winds. In addition, the impact of atmospheric turbulence was examined for the portion of flight from Mach 3.5 to touchdown. This analysis showed that the vehicle remained controllable and could successfully land even in the presence of off-nominal atmospheric conditions.

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

    Science.gov (United States)

    Liu, Mianfang; Xiong, Shengwu; Li, Bixiang

    2016-05-01

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

  12. Orion Crew Exploration Vehicle Launch Abort System Guidance and Control Analysis Overview

    Science.gov (United States)

    Davidson, John B.; Kim, Sungwan; Raney, David L.; Aubuchon, Vanessa V.; Sparks, Dean W.; Busan, Ronald C.; Proud, Ryan W.; Merritt, Deborah S.

    2008-01-01

    Aborts during the critical ascent flight phase require the design and operation of Orion Crew Exploration Vehicle (CEV) systems to escape from the Crew Launch Vehicle (CLV) and return the crew safely to the Earth. To accomplish this requirement of continuous abort coverage, CEV ascent abort modes are being designed and analyzed to accommodate the velocity, altitude, atmospheric, and vehicle configuration changes that occur during ascent. Aborts from the launch pad to early in the flight of the CLV second stage are performed using the Launch Abort System (LAS). During this type of abort, the LAS Abort Motor is used to pull the Crew Module (CM) safely away from the CLV and Service Module (SM). LAS abort guidance and control studies and design trades are being conducted so that more informed decisions can be made regarding the vehicle abort requirements, design, and operation. This paper presents an overview of the Orion CEV, an overview of the LAS ascent abort mode, and a summary of key LAS abort analysis methods and results.

  13. Ascent, Transition, Entry, and Abort Guidance Algorithm Design for the X-33 Vehicle

    Science.gov (United States)

    Hanson, John M.; Coughlin, Dan J.; Dukeman, Gregory A.; Mulqueen, John A.; McCarter, James W.

    1998-01-01

    One of the primary requirements for X-33 is that it be capable of flying autonomously. That is, onboard computers must be capable of commanding the entire flight from launch to landing, including cases where a single engine failure abort occurs. Guidance algorithms meeting these requirements have been tested in simulation and have been coded into prototype flight software. These algorithms must be sufficiently robust to account for vehicle and environmental dispersions, and must issue commands that result in the vehicle operating, within all constraints. Continual tests of these algorithms (and modifications as necessary) will occur over the next year as the X-33 nears its first flight. This paper describes the algorithms in use for X-33 ascent, transition, and entry flight, as well as for the powered phase of PowerPack-out (PPO) aborts (equivalent in thrust impact to losing an engine). All following discussion refers to these phases of flight when discussing guidance. The paper includes some trajectory results and results of dispersion analysis.

  14. A New Strategy of Guidance Command Generation for Re-entry Vehicle

    Directory of Open Access Journals (Sweden)

    Xie DaoCheng

    2013-01-01

    Full Text Available Guidance command for re-entry vehicle can be in various formats, but the Euler angles can be provided directly by gyros, so designers used to develop autopilot with commands of Euler angles. After the generation of commands of angle of attack and sideslip angle, it’s important to settle how to convert commands of angle of attack and sideslip angle to commands of Euler angles. Traditional conversion strategy relies on bank angle, but the solution to bank angle comprises complicated calculation and can’t be precise. This paper introduces a new conversion strategy of guidance command. This strategy relies on the relative position and velocity measured by seeker, an auxiliary coordinate is established as a transition, the transformation matrix from launch coordinate to body coordinate is solved in a new way, then the commands of Euler angles are obtained. The calculation of bank angle is avoided. The autopilot designed with the converted Euler-angle commands, can track commands of angle of attack and sideslip angle steadily. The vehicle reaches the target point precisely. Simulation results show that the new conversion strategy based on seeker information from commands of angle of attack and sideslip angle to Euler-angle commands is valid.

  15. A New Strategy of Guidance Command Generation for Re-entry Vehicle

    Directory of Open Access Journals (Sweden)

    Xie Daocheng

    2013-01-01

    Full Text Available Guidance command for re-entry vehicle can be in lots of formats, but the Euler angles can be provided directly by gyros, so designers used to develop autopilot with commands of Euler angles. After the generation of commands of attack angle and sideslip angle, it’s important to settle how to convert commands of attack angle and sideslip angle to commands of Euler angles. Traditional conversion strategy relies on bank angle, solution to bank angle comprises complicated calculation and can’t be precise. This paper introduces a new conversion strategy of guidance command. This strategy relies on the relative position and velocity measured by seeker, an auxiliary coordinateis established as a transition, the transformation matrix from launch coordinate to body coordinate is solved in a new way, then the commands of Euler angles are obtained. The calculation of bank angle is avoided. The autopilot designed with the converted Euler-angle commands, can track commands of attack angle and sideslip angle steadily.The vehicle reaches the target point precisely. Simulation results show that the new conversion strategy based on seeker information from commands of attack angle and sideslip angle to Euler-angle commands is right.Defence Science Journal, 2013, 63(1, pp.93-100, DOI:http://dx.doi.org/10.14429/dsj.63.2360

  16. Real Time Mid-course Maneuver and Guidance of a Generic Reentry Vehicle

    Directory of Open Access Journals (Sweden)

    Avinash Chander

    2013-07-01

    Full Text Available The aim of any mission is to accomplish the final objective with desired accuracy and the same is valid for a generic launch vehicle. In many missions it is necessary to execute mid-course maneuvers with an intentional diversion trajectory to create a counter measure or to avoid certain specific known geographical locations. The current work elaborates a novel and practically implementable mid-course maneuver and an ascent phase guidance of a reentry vehicle executing an in-flight determined mid-course maneuver (trajectory reshaping without compromising the accuracy of the final achieved target position. The robustness of the algorithm is validated with 6DoF simulation results by considering the dispersion of the burnout state vector conditions which arises due to variations in thrust profile, aerodynamics characteristics of the vehicle, atmosphere, etc.Defence Science Journal, 2013, 63(4, pp.346-354, DOI:http://dx.doi.org/10.14429/dsj.63.4207

  17. A weak Hamiltonian finite element method for optimal guidance of an advanced launch vehicle

    Science.gov (United States)

    Hodges, Dewey H.; Calise, Anthony J.; Bless, Robert R.; Leung, Martin

    1989-01-01

    A temporal finite-element method based on a mixed form of the Hamiltonian weak principle is presented for optimal control problems. The mixed form of this principle contains both states and costates as primary variables, which are expanded in terms of nodal values and simple shape functions. Time derivatives of the states and costates do not appear in the governing variational equation; the only quantities whose time derivatives appear therein are virtual states and virtual costates. Numerical results are presented for an elementary trajectory optimization problem; they show very good agreement with the exact solution along with excellent computational efficiency and self-starting capability. The feasibility of this approach for real-time guidance applications is evaluated. A simplified model for an advanced launch vehicle application that is suitable for finite-element solution is presented.

  18. Towards cooperative guidance and control of highly automated vehicles: H-Mode and Conduct-by-Wire.

    Science.gov (United States)

    Flemisch, Frank Ole; Bengler, Klaus; Bubb, Heiner; Winner, Hermann; Bruder, Ralph

    2014-01-01

    This article provides a general ergonomic framework of cooperative guidance and control for vehicles with an emphasis on the cooperation between a human and a highly automated vehicle. In the twenty-first century, mobility and automation technologies are increasingly fused. In the sky, highly automated aircraft are flying with a high safety record. On the ground, a variety of driver assistance systems are being developed, and highly automated vehicles with increasingly autonomous capabilities are becoming possible. Human-centred automation has paved the way for a better cooperation between automation and humans. How can these highly automated systems be structured so that they can be easily understood, how will they cooperate with the human? The presented research was conducted using the methods of iterative build-up and refinement of framework by triangulation, i.e. by instantiating and testing the framework with at least two derived concepts and prototypes. This article sketches a general, conceptual ergonomic framework of cooperative guidance and control of highly automated vehicles, two concepts derived from the framework, prototypes and pilot data. Cooperation is exemplified in a list of aspects and related to levels of the driving task. With the concept 'Conduct-by-Wire', cooperation happens mainly on the guidance level, where the driver can delegate manoeuvres to the automation with a specialised manoeuvre interface. With H-Mode, a haptic-multimodal interaction with highly automated vehicles based on the H(orse)-Metaphor, cooperation is mainly done on guidance and control with a haptically active interface. Cooperativeness should be a key aspect for future human-automation systems. Especially for highly automated vehicles, cooperative guidance and control is a research direction with already promising concepts and prototypes that should be further explored. The application of the presented approach is every human-machine system that moves and includes high

  19. Microgravity monitoring instrument development and application to vernier guidance, navigation, and vehicle control

    Science.gov (United States)

    Howell, Joseph J.

    1992-01-01

    The fact that a spacecraft traveling through the 'vacuum' of space conforms to the classical Keplerian ellipse has recently been disproven. It is now well known that such a vehicle is acted on by many external forces such as drag in the rarefied particle atmosphere, solar wind and particle impact. This paper discusses the development of sensors and sensor systems to measure these minute forces of acceleration/deceleration. Four systems will be discussed: a 10 exp -4 g system, a 10 exp -6 g system, a 10 exp -(6-8) g system and a 10 exp -9 g system. The design of each system will be explained along with the advantages/disadvantages of each. Various applications unique to each system will be discussed. Configurations, design schemes, test plans and calibration procedures, both in the ground laboratory and inflight, will be presented. The current design/development/operational status of each system will be examined and future plans discussed. Application to aerodynamic studies and vernier guidance, navigation, and vehicle control will also be examined.

  20. Samen werken aan Automatische VoertuigGeleiding: aanzet tot een businessplan [Working together on Automated Vehicle Guidance; Preliminary business plan

    NARCIS (Netherlands)

    Coemet, M.J.; Vos, A.P. de; Arem, B. van; Brookhuis, K.A.; Heijer, T.; Marchau, V.A.W.J.

    1998-01-01

    Automated Vehicle Guidance (AVG) systems are expected to have a major impact on traffic and transport. In order to reap the benefits and offset or avoid the disadvantages of AVG, correct and timely choices will have to be made. The Ministry of Transport, Public Works and Water Manage-ment, the Unive

  1. A new guidance law for a tactical surface-to-surface missile

    Directory of Open Access Journals (Sweden)

    Danilo V. Ćuk

    2012-01-01

    Full Text Available Modern tactical surface-to-surface missiles, equipped with strapdown inertial navigation systems, achieve very good accuracy compared with free-flight rockets. The probable range dispersion mainly depends on instruments errors and longitudinal disturbances such as rocket motor total-impulse deviation as well as differences between the estimated and actual values of the axial force and head wind. This paper gives an extension of the correlated velocity concept for surface-to-surface missiles without a thrust-terminating mechanism. The calculated parameters of the correlated velocity are stored into the memory of an onboard guidance computer. On the basis of the correlated velocity concept, the modified proportional navigation with the adjustment of the time-to-go of the missile to the target was proposed. It is shown that the new guidance law can compensate for the longitudinal disturbances of different levels successfully. The effectiveness of the proposed guidance method was confirmed by means of the calculated probable range and lateral dispersion for the anticipated disturbances in the guidance system.

  2. Mission analysis and guidance, navigation, and control design for rendezvous and docking phase of advanced reentry vehicle mission

    Science.gov (United States)

    Strippoli, L.; Colmenarejo, P.; Strauch, H.

    2013-12-01

    Advanced Reentry Vehicle (ARV) belongs to the family of vehicles designed to perform rendezvous and docking (RvD) with the International space station (ISS) [1]. Differently from its predecessor ATV (Automated Transfer Vehicle), the ARV will transport a reentry capsule, equipped with a heatshield and able to bring back cargo, experiments, or, as a possible future development, even crew, being this latter scenario very attracting in view of the Space Shuttle retirement. GMV, as subcontractor of EADS-Astrium Germany, is in charge of the RvD and departure mission analysis and GNC (Guidance, Navigation, and Control) design of ARV mission. This paper will present the main outcomes of the study.

  3. Remote control of planetary surface vehicles.

    Science.gov (United States)

    Heer, E.

    1973-01-01

    A remotely manned system consisting of an earth-based control center and a remote rover system on the planetary surface is assumed to extend to the remote site the sensory, manipulative and certain intellectual capabilities of humans here on earth. Required system functions, including scientific payload functions, vehicle functions and ground-based human control functions are discussed and the effects of communication delay and increased remote automaticity on system performance are investigated. To accomplish the required operations for scientific exploration, the control of the remote system requires the development of techniques to deal with problems of long communication time delays so that the performance in terms of operation speed can be increased to acceptable levels. Increased operational performance can be achieved primarily by increasing the rate of useful information flow in the man-machine sensor-control loop, or by increasing the autonomous capabilities of the remote system or by both.

  4. Statistical methods for launch vehicle guidance, navigation, and control (GN&C) system design and analysis

    Science.gov (United States)

    Rose, Michael Benjamin

    A novel trajectory and attitude control and navigation analysis tool for powered ascent is developed. The tool is capable of rapid trade-space analysis and is designed to ultimately reduce turnaround time for launch vehicle design, mission planning, and redesign work. It is streamlined to quickly determine trajectory and attitude control dispersions, propellant dispersions, orbit insertion dispersions, and navigation errors and their sensitivities to sensor errors, actuator execution uncertainties, and random disturbances. The tool is developed by applying both Monte Carlo and linear covariance analysis techniques to a closed-loop, launch vehicle guidance, navigation, and control (GN&C) system. The nonlinear dynamics and flight GN&C software models of a closed-loop, six-degree-of-freedom (6-DOF), Monte Carlo simulation are formulated and developed. The nominal reference trajectory (NRT) for the proposed lunar ascent trajectory is defined and generated. The Monte Carlo truth models and GN&C algorithms are linearized about the NRT, the linear covariance equations are formulated, and the linear covariance simulation is developed. The performance of the launch vehicle GN&C system is evaluated using both Monte Carlo and linear covariance techniques and their trajectory and attitude control dispersion, propellant dispersion, orbit insertion dispersion, and navigation error results are validated and compared. Statistical results from linear covariance analysis are generally within 10% of Monte Carlo results, and in most cases the differences are less than 5%. This is an excellent result given the many complex nonlinearities that are embedded in the ascent GN&C problem. Moreover, the real value of this tool lies in its speed, where the linear covariance simulation is 1036.62 times faster than the Monte Carlo simulation. Although the application and results presented are for a lunar, single-stage-to-orbit (SSTO), ascent vehicle, the tools, techniques, and mathematical

  5. A Vision System for Real Time Road and Object Recognition for Vehicle Guidance

    Science.gov (United States)

    Jackson, T. A.; Samuelsen, G. S.

    1987-02-01

    One crucial component of a control system for autonomous vehicle guidance is real time image analysis. This system part is burdened by the maximum flow of information. To overcome the high demands in computation power a combination of knowledge based scene analysis and special hardware has been developed. The use of knowledge based image analysis supports real time processing not by schematically evaluating all parts of the image, but only evaluating those which contain relevant information. This is due to the fact that in many practical problems the relevant information is very unevenly distributed over the image. Preknowledge of the problem or the aim of the mission and expectations or predictions about the scene sustantially reduce the amount of information to be processed. The operations during such an analysis may be divided into two classes - simple processes, e.g. filters, correlation, contour processing and simple search strategies - complex search and control strategy This classification supplied the concept for a special hardware. The complex tasks are performed by a universal processor 80286 while the remaining tasks are executed by a special coprocessor (including image memory). This combination permits the use of filter masks with a arbitrary geometry together with a powerful search strategy. A number of these basic modules may be configured into a multiprocessor system. The universal processor is programmed in a high level language. To support the coprocessor a set of software tools has been built. They permit interactive graphical manipulation of filtermasks, generation of simple search strategies and non real time simulation. Also the real data structures that control the function of the coprocessor are generated by this software package. The system is used within our autonomous vehicle project. One set of algorithms tracks the border lines of the road even if they are broken or disturbed by dirt. Also shadows of bridges crossing the road are

  6. Online Trajectory Reshaping for a Launch Vehicle to Minimize the Final Error Caused by Navigation and Guidance

    Directory of Open Access Journals (Sweden)

    Tessy Thomas

    2013-05-01

    Full Text Available Autonomous launch vehicles, once lifted off from the launch pad, equipped with an onboard intelligence which aids in achieving the mission objectives with high accuracy. The accuracy of the mission depends basically on navigation and guidance errors caused at burnout condition, after which the vehicle follows an elliptical path upto impact. The paper describes how to handle the final impact and injection error caused by these navigation and guidance errors. In the current work the initial burnout conditions are tuned and corrected such that the terminal impact point is achieved within the desired tolerance bounds. A two point boundary value problem is solved using the gradient method, for determining the impact errors. The algorithm is validated by simulation studies for various burnout conditions.Defence Science Journal, 2013, 63(3, pp.254-261, DOI:http://dx.doi.org/10.14429/dsj.63.2414

  7. Online Trajectory Reshaping for a Launch Vehicle to Minimize the Final Error Caused by Navigation and Guidance

    Directory of Open Access Journals (Sweden)

    Tessy Thomas

    2013-05-01

    Full Text Available Autonomous launch vehicles, once lifted off from the launch pad, equipped with an onboard intelligence which aids in achieving the mission objectives with high accuracy. The accuracy of the mission depends basically on navigation and guidance errors caused at burnout condition, after which the vehicle follows an elliptical path upto impact. The paper describes how to handle the final impact and injection error caused by these navigation and guidance errors. In the current work the initial burnout conditions are tuned and corrected such that the terminal impact point is achieved within the desired tolerance bounds. A two point boundary value problem is solved using the gradient method, for determining the impact errors. The algorithm is validated by simulation studies for various burnout conditions.

  8. Development of A Three-Dimensional Guidance System for Long-Range Maneuvering of A Miniature Autonomous Underwater Vehicle

    Institute of Scientific and Technical Information of China (English)

    Mansour ATAEI; Aghil YOUSEFI-KOMA

    2014-01-01

    The present paper introduces a three-dimensional guidance system developed for a miniature Autonomous Underwater Vehicle (AUV). The guidance system determines the best trajectory for the vehicle based on target behavior and vehicle capabilities. The dynamic model of this novel AUV is derived based on its special characteristics such as the horizontal posture and the independent diving mechanism. To design the guidance strategy, the main idea is to select the desired depth, presumed proportional to the horizontal distance of the AUV and the target. By connecting the two with a straight line, this strategy helps the AUV move in a trajectory sufficiently close to this line. The adjacency of the trajectory to the line leads to reasonably short travelling distances and avoids unsafe areas. Autopilots are designed using sliding mode controller. Two different engagement geometries are considered to evaluate the strategy’s performance:stationary target and moving target. The simulation results show that the strategy can provide sufficiently fast and smooth trajectories in both target situations.

  9. Development of a three-dimensional guidance system for long-range maneuvering of a miniature autonomous underwater vehicle

    Science.gov (United States)

    Ataei, Mansour; Yousefi-Koma, Aghil

    2014-12-01

    The present paper introduces a three-dimensional guidance system developed for a miniature Autonomous Underwater Vehicle (AUV). The guidance system determines the best trajectory for the vehicle based on target behavior and vehicle capabilities. The dynamic model of this novel AUV is derived based on its special characteristics such as the horizontal posture and the independent diving mechanism. To design the guidance strategy, the main idea is to select the desired depth, presumed proportional to the horizontal distance of the AUV and the target. By connecting the two with a straight line, this strategy helps the AUV move in a trajectory sufficiently close to this line. The adjacency of the trajectory to the line leads to reasonably short travelling distances and avoids unsafe areas. Autopilots are designed using sliding mode controller. Two different engagement geometries are considered to evaluate the strategy's performance: stationary target and moving target. The simulation results show that the strategy can provide sufficiently fast and smooth trajectories in both target situations.

  10. Surface effect vehicles and surface effect: General studies. Citations from the NTIS data base

    Science.gov (United States)

    Habercom, G. E., Jr.

    1980-08-01

    The bibliography contains 180 citations in which the design of surface effect vehicles, their utilization, and their aerodynamic characteristics are investigated. Vehicles or ships in marine environments are not included.

  11. Coordinated path following of multiple underacutated marine surface vehicles along one curve.

    Science.gov (United States)

    Liu, Lu; Wang, Dan; Peng, Zhouhua

    2016-09-01

    This paper investigates the coordinated path following problem for a fleet of underactuated marine surface vehicles (MSVs) along one curve. The dedicated control design is divided into two tasks. One is to steer individual underactuated MSV to track the given spatial path, and the other is to force the vehicles dispersed on a parameterized path subject to the constraints of a communication network. Specifically, a robust individual path following controller is developed based on a line-of-sight (LOS) guidance law and a reduced-order extended state observer (ESO). The vehicle sideslip angle due to environmental disturbances can be exactly identified. Then, the vehicle coordination is achieved by a path variable containment approach, under which the path variables are evenly dispersed between two virtual leaders. Another reduced-order ESO is developed to identify the composite disturbance related to the speed of virtual leaders and neighboring vehicles. The proposed coordination design is distributed since the reference speed does not need to be known by all vehicles as a priori. The input-to-state stability of the closed-loop network system is established via cascade theory. Simulation results demonstrate the effectiveness of the proposed design method.

  12. Vehicle-class Specific Route-guidance of Freeway Traffic by Model-predictive Control

    NARCIS (Netherlands)

    Schreiter, T.; Landman, R.L.; Van Lint, J.W.C.; Hegyi, A.; Hoogendoorn, S.P.

    2012-01-01

    Few Active Traffic Management measures proposed in the past consider the distinction of different vehicle classes. Examples of vehicle-class specific measures are truck lanes and high-occupancy/toll (HOT) lanes. We propose that the distinction of different vehicle classes, with different flow

  13. Design and integration of vision based sensors for unmanned aerial vehicles navigation and guidance

    Science.gov (United States)

    Sabatini, Roberto; Bartel, Celia; Kaharkar, Anish; Shaid, Tesheen

    2012-04-01

    In this paper we present a novel Navigation and Guidance System (NGS) for Unmanned Aerial Vehicles (UAVs) based on Vision Based Navigation (VBN) and other avionics sensors. The main objective of our research is to design a lowcost and low-weight/volume NGS capable of providing the required level of performance in all flight phases of modern small- to medium-size UAVs, with a special focus on automated precision approach and landing, where VBN techniques can be fully exploited in a multisensory integrated architecture. Various existing techniques for VBN are compared and the Appearance-based Navigation (ABN) approach is selected for implementation. Feature extraction and optical flow techniques are employed to estimate flight parameters such as roll angle, pitch angle, deviation from the runway and body rates. Additionally, we address the possible synergies between VBN, Global Navigation Satellite System (GNSS) and MEMS-IMU (Micro-Electromechanical System Inertial Measurement Unit) sensors and also the use of Aircraft Dynamics Models (ADMs) to provide additional information suitable to compensate for the shortcomings of VBN sensors in high-dynamics attitude determination tasks. An Extended Kalman Filter (EKF) is developed to fuse the information provided by the different sensors and to provide estimates of position, velocity and attitude of the platform in real-time. Two different integrated navigation system architectures are implemented. The first uses VBN at 20 Hz and GPS at 1 Hz to augment the MEMS-IMU running at 100 Hz. The second mode also includes the ADM (computations performed at 100 Hz) to provide augmentation of the attitude channel. Simulation of these two modes is performed in a significant portion of the Aerosonde UAV operational flight envelope and performing a variety of representative manoeuvres (i.e., straight climb, level turning, turning descent and climb, straight descent, etc.). Simulation of the first integrated navigation system architecture

  14. Primary safe criterion of earth-brushing flight for flying vehicle over digital surface model

    Institute of Scientific and Technical Information of China (English)

    赵敏; 林行刚; 赵乃国

    2004-01-01

    In modem terrain-following guidance it is an important index for flight vehicle to cruise about safely and normally. On the basis of a constructing method of digital surface model (DSM), the definition, classification and scale analysis of an isolated obstacle threatening flight safety of terrain-following guidance are made. When the interval of verticaland cross-sections on DSM is 12.5 m, the proportion of isolated obstacles to the data amount of DSM model to be loaded is optimal. The main factors influencing the lowest flying height in terrain-following guidance are analyzed, and a primary safe criterion of the lowest flying height over DSM model is proposed. According to their test errors, the lowest flying height over 1:10 000 DSM model can reach 40.5 m~45.0 m in terrain-following guidance. It is shown from the simulation results of a typical urban district that the proposed models and methods are reasonable and feasible.

  15. Study of automatic and manual terminal guidance and control systems for space shuttle vehicles. Volume 1: Sections 1 through 3

    Science.gov (United States)

    Osder, S.; Keller, R.

    1971-01-01

    The results of a study to analyze, design, and evaluate guidance and control systems are presented that start at an altitude of about 100,000 feet and bring the unpowered space shuttle orbiters to a precision horizontal landing. The systems under consideration included fully automatic versions which involve no pilot participation as well as various manual configurations that provide combinations of displays and control augmentation which permit the pilot to control the vehicle to a successful landing. Two classes of vehicles were studied: the low cross range or straight-wing orbiter and the high cross range or delta-wing (delta body) orbiter. The recommended navigation, guidance and control system is shown to be compatible with realistic physical constraints that would exist in space shuttlecraft and to be consistent with the 1971 avionics equipment state of the art. Aircraft capable of aerodynamically simulating the various candidate space shuttlecraft in their unpowered, terminal area descent were investigated, and flight test recommendations, including system mechanizations, are made.

  16. Study of automatic and manual terminal guidance and control systems for space shuttle vehicles. Volume 2: Section 4 through appendix B

    Science.gov (United States)

    Osder, S.; Keller, R.

    1971-01-01

    Guidance and control design studies that were performed for three specific space shuttle candidate vehicles are described. Three types of simulation were considered. The manual control investigations and pilot evaluations of the automatic system performance is presented. Recommendations for systems and equipment, both airborne and ground-based, necessary to flight test the guidance and control concepts for shuttlecraft terminal approach and landing are reported.

  17. Guidance and Control of an Autonomous Soaring Vehicle with Flight Test Results

    Science.gov (United States)

    Allen, Michael J.

    2007-01-01

    A guidance and control method was developed to detect and exploit thermals for energy gain. Latency in energy rate estimation degraded performance. The concept of a UAV harvesting energy from the atmosphere has been shown to be feasible with existing technology. Many UAVs have similar mission constraints to birds and sailplanes. a) Surveillance; b) Point to point flight with minimal energy; and c) Increased ground speed.

  18. Application of Automated Guided Vehicle (AGV) Based on Inductive Guidance for Newsprint Rolls Transportation System

    Institute of Scientific and Technical Information of China (English)

    陈超; 王冰; 叶庆泰

    2004-01-01

    The paper presents the development and performance of a kinematics control scheme for the AGV based on inductive guidance in transporting newsprint rolls. The required error is pre-computed using a kinematics model of the AGV taking into account the effect of various factors that contribute to improve tracking performance of the AGV. Simulation and experimental results illustrate that the kinematics model performs well and the results of various factors contribute to tracking performance of the AGV.

  19. Path planning on satellite images for unmanned surface vehicles

    Directory of Open Access Journals (Sweden)

    Joe-Ming Yang

    2015-01-01

    Full Text Available In recent years, the development of autonomous surface vehicles has been a field of increasing research interest. There are two major areas in this field: control theory and path planning. This study focuses on path planning, and two objectives are discussed: path planning for Unmanned Surface Vehicles (USVs and implementation of path planning in a real map. In this paper, satellite thermal images are converted into binary images which are used as the maps for the Finite Angle A * algorithm (FAA *, an advanced A * algorithm that is used to determine safer and suboptimal paths for USVs. To plan a collision-free path, the algorithm proposed in this article considers the dimensions of surface vehicles. Furthermore, the turning ability of a surface vehicle is also considered, and a constraint condition is introduced to improve the quality of the path planning algorithm, which makes the traveled path smoother. This study also shows a path planning experiment performed on a real satellite thermal image, and the path planning results can be used by an USV

  20. Terminal Multiple Surface Sliding Guidance for Planetary Landing: Development, Tuning and Optimization via Reinforcement Learning

    Science.gov (United States)

    Furfaro, Roberto; Wibben, Daniel R.; Gaudet, Brian; Simo, Jules

    2015-03-01

    The problem of achieving pinpoint landing accuracy in future space missions to planetary bodies such as the Moon or Mars presents many challenges, including the requirements of higher accuracy and degree of flexibility. These new challenges may require the development of a new class of guidance algorithms. In this paper, a nonlinear guidance algorithm for planetary landing is proposed and analyzed. Based on Higher-Order Sliding Control (HOSC) theory, the Multiple Sliding Surface Guidance (MSSG) algorithm has been specifically designed to take advantage of the ability of the system to reach multiple sliding surfaces in a finite time. As a result, a guidance law that is both globally stable and robust against unknown, but bounded perturbations is devised. The proposed MSSG does not require any off-line trajectory generation, but the acceleration command is instead generated directly as function of the current and final (target) state. However, after initial analysis, it has been noted that the performance of MSSG critically depends on the choice in guidance gains. MSSG-guided trajectories have been compared to an open-loop fuel-efficient solution to investigate the relationship between the MSSG fuel performance and the selection of the guidance parameters. A full study has been executed to investigate and tune the parameters of MSSG utilizing reinforcement learning in order to truly optimize the performance of the MSSG algorithm in powered descent scenarios. Results show that the MSSG algorithm can indeed generate closed-loop trajectories that come very close to the optimal solution in terms of fuel usage. A full comparison of the trajectories is included, as well as a further Monte Carlo analysis examining the guidance errors of the MSSG algorithm under perturbed conditions using the optimized set of parameters.

  1. Energy-heading transients in atmospheric flight guidance for airbreathing hypersonic vehicles

    Science.gov (United States)

    Cliff, Eugene M.; Well, KLAUS-H.

    1991-01-01

    A time-range-fuel optimization problem is formulated for an airbreathing, hypersonic vehicle. Singular perturbation theory is used to decompose the problem into simpler subproblems. Analysis of the cruise-dash problem shows the importance of a Mach-limit. Energy-heading transients are studied and a family of trajectories, fairing asymptotically to a cruise condition, are generated.

  2. Hybrid Guidance Control for a Hypervelocity Small Size Asteroid Interceptor Vehicle

    Science.gov (United States)

    Zebenay, Melak M.; Lyzhoft, Joshua R.; Barbee, Brent W.

    2017-01-01

    Near-Earth Objects (NEOs) are comets and/or asteroids that have orbits in proximity with Earth's own orbit. NEOs have collided with the Earth in the past, which can be seen at such places as Chicxulub crater, Barringer crater, and Manson crater, and will continue in the future with potentially significant and devastating results. Fortunately such NEO collisions with Earth are infrequent, but can happen at any time. Therefore it is necessary to develop and validate techniques as well as technologies necessary to prevent them. One approach to mitigate future NEO impacts is the concept of high-speed interceptor. This concept is to alter the NEO's trajectory via momentum exchange by using kinetic impactors as well as nuclear penetration devices. The interceptor has to hit a target NEO at relative velocity which imparts a sufficient change in NEO velocity. NASA's Deep Impact mission has demonstrated this scenario by intercepting Comet Temple 1, 5 km in diameter, with an impact relative speed of approximately 10 km/s. This paper focuses on the development of hybrid guidance navigation and control (GNC) algorithms for precision hypervelocity intercept of small sized NEOs. The spacecraft's hypervelocity and the NEO's small size are critical challenges for a successful mission as the NEO will not fill the field of view until a few seconds before intercept. The investigation needs to consider the error sources modeled in the navigation simulation such as spacecraft initial state uncertainties in position and velocity. Furthermore, the paper presents three selected spacecraft guidance algorithms for asteroid intercept and rendezvous missions. The selected algorithms are classical Proportional Navigation (PN) based guidance that use a first order difference to compute the derivatives, Three Plane Proportional Navigation (TPPN), and the Kinematic Impulse (KI). A manipulated Bennu orbit that has been changed to impact Earth will be used as a demonstrative example to compare the

  3. Micropatterned polysaccharide surfaces via laser ablation for cell guidance

    Energy Technology Data Exchange (ETDEWEB)

    Barbucci, Rolando; Lamponi, Stefania; Pasqui, Daniela; Rossi, Antonella; Weber, Elisabetta

    2003-03-03

    Micropatterned materials were obtained by a controlled laser ablation of a photoimmobilised homogeneous layer of hyaluronic acid (Hyal) and its sulphated derivative (HyalS). The photoimmobilisation was performed by coating the polysaccharide, adequately functionalised with a photoreactive group, on aminosilanised glass substrate and immobilising it on the surface under UV light. Hyal or HyalS photoimmobilised samples were then subjected to laser ablation with wavelengths in the UV regions in order to drill the pattern. Four different patterns with stripes of 100, 50, 25 and 10 {mu}m were generated. A chemical characterisation by attenuated total reflection/Fourier transform infrared (ATR/FT-IR) and time of flight-secondary ions mass spectrometry (TOF-SIMS) confirmed the success of the laser ablation procedure and the presence of alternating stripes of polysaccharide and native glass. The exact dimensions of the stripes were determined by atomic force microscopy. The analysis of cell behaviour in terms of adhesion, proliferation and movement using mouse fibroblasts (3T3 line) and bovine aortic endothelial cells (BAEC) was also performed.

  4. Fault diagnosis and fault-tolerant control and guidance for aerospace vehicles from theory to application

    CERN Document Server

    Zolghadri, Ali; Cieslak, Jerome; Efimov, Denis; Goupil, Philippe

    2014-01-01

    Fault Diagnosis and Fault-Tolerant Control and Guidance for Aerospace demonstrates the attractive potential of recent developments in control for resolving such issues as improved flight performance, self-protection and extended life of structures. Importantly, the text deals with a number of practically significant considerations: tuning, complexity of design, real-time capability, evaluation of worst-case performance, robustness in harsh environments, and extensibility when development or adaptation is required. Coverage of such issues helps to draw the advanced concepts arising from academic research back towards the technological concerns of industry. Initial coverage of basic definitions and ideas and a literature review gives way to a treatment of important electrical flight control system failures: the oscillatory failure case, runaway, and jamming. Advanced fault detection and diagnosis for linear and nonlinear systems are described. Lastly recovery strategies appropriate to remaining acuator/sensor/c...

  5. Adaptive block dynamic surface control for integrated missile guidance and autopilot

    Institute of Scientific and Technical Information of China (English)

    Hou Mingzhe; Liang Xiaoling; Duan Guangren

    2013-01-01

    A novel integrated guidance and autopilot design method is proposed for homing missiles based on the adaptive block dynamic surface control approach.The fully integrated guidance and autopilot model is established by combining the nonlinear missile dynamics with the nonlinear dynamics describing the pursuit situation of a missile and a target in the three-dimensional space.The integrated guidance and autopilot design problem is further converted to a state regulation problem of a time-varying nonlinear system with matched and unmatched uncertainties.A new and simple adaptive block dynamic surface control algorithm is proposed to address such a state regulation problem.The stability of the closed-loop system is proven based on the Lyapunov theory.The six degrees of freedom (6DOF) nonlinear numerical simulation results show that the proposed integrated guidance and autopilot algorithm can ensure the accuracy of target interception and the robust stability of the closed-loop system with respect to the uncertainties in the missile dynamics

  6. Expert S-surface control for autonomous underwater vehicles

    Institute of Scientific and Technical Information of China (English)

    ZHANG Lei; PANG Yong-jie; SU Yu-min; ZHAO Fu-long; QIN Zai-bai

    2008-01-01

    S-surface control has proven to be an effective means for motion control of underwater autonomous vehicles (AUV). However there are still problems maintaining steady precision of course due to the constant need to adjust parameters,especially where there are disturbing currents. Thus an intelligent integral was introduced to improve precision. An expert S-surface control was developed to tune the parameters on-line,based on the expert system,it provides S-surface control according to practical experience and control knowledge. To prevent control output over-compensation,a fuzzy neural network was included to adjust the production rules to the knowledge base. Experiments were conducted on an AUV simulation platform,and the results show that the expert S-surface controller performs better than an S-surface controller in environments with currents,producing good steady precision of course in a robust way.

  7. Sugar-fiber Imprinting to Generate Microgrooves on Polymeric Film Surfaces for Contact Guidance of Cells

    Institute of Scientific and Technical Information of China (English)

    屈泽华; 丁建东

    2012-01-01

    Anisotropic surface topography is known to induce the contact guidance of cells, and facile and biocompatible approaches of the physical modification of the pertinent matrix surfaces are thus meaningful for biomaterials. Herein, we put forward a sugar-fiber imprinting technique to generate microgrooves on hydrophobic polymers demonstrated by the poly(lactic-eo-glycolic acid) (PLGA) films. Microgrooves were conveniently generated after removing sugar fibers simply by water. The resulting locally anisotropic microgrooves were confirmed to elongate the cells cultured on the surface.

  8. Phenomenon of "contact guidance" on the surface with nano-micro-groove-like pattern and cell physiological effects

    Institute of Scientific and Technical Information of China (English)

    ZHOU Feng; YUAN Lin; HUANG He; CHEN Hong

    2009-01-01

    The topography of material surface has important influence on cell behavior and physiological functions. Groove-like pattern has drawn much attention among various patterns,due to the phenomenon of "contact guidance" induced by this kind of topography. This review mainly focuses on "contact guidance" formation as well as its influence on cell behavior and physiological effects. The possible mechanisms of "contact guidance" formation were discussed. The research trend and the potential applications were also suggested.

  9. Rapid near-optimal trajectory generation and guidance law development for single-stage-to-orbit airbreathing vehicles

    Science.gov (United States)

    Calise, A. J.; Flandro, G. A.; Corban, J. E.

    1990-01-01

    General problems associated with on-board trajectory optimization, propulsion system cycle selection, and with the synthesis of guidance laws were addressed for an ascent to low-earth-orbit of an air-breathing single-stage-to-orbit vehicle. The NASA Generic Hypersonic Aerodynamic Model Example and the Langley Accelerator aerodynamic sets were acquired and implemented. Work related to the development of purely analytic aerodynamic models was also performed at a low level. A generic model of a multi-mode propulsion system was developed that includes turbojet, ramjet, scramjet, and rocket engine cycles. Provisions were made in the dynamic model for a component of thrust normal to the flight path. Computational results, which characterize the nonlinear sensitivity of scramjet performance to changes in vehicle angle of attack, were obtained and incorporated into the engine model. Additional trajectory constraints were introduced: maximum dynamic pressure; maximum aerodynamic heating rate per unit area; angle of attack and lift limits; and limits on acceleration both along and normal to the flight path. The remainder of the effort focused on required modifications to a previously derived algorithm when the model complexity cited above was added. In particular, analytic switching conditions were derived which, under appropriate assumptions, govern optimal transition from one propulsion mode to another for two cases: the case in which engine cycle operations can overlap, and the case in which engine cycle operations are mutually exclusive. The resulting guidance algorithm was implemented in software and exercised extensively. It was found that the approximations associated with the assumed time scale separation employed in this work are reasonable except over the Mach range from roughly 5 to 8. This phenomenon is due to the very large thrust capability of scramjets in this Mach regime when sized to meet the requirement for ascent to orbit. By accounting for flight path

  10. VaMoRs-P: an advanced platform for visual autonomous road vehicle guidance

    Science.gov (United States)

    Maurer, Markus; Behringer, Reinhold; Dickmanns, Dirk; Hildebrandt, Thomas; Thomanek, Frank; Schiehlen, Joachim; Dickmanns, Ernst D.

    1995-01-01

    A sedan Mercedes 500 SEL has been equipped with active bifocal vision systems. Road and object recognition is performed both in a look-ahead and in a look-back region; this allows to servo-maintain an internal representation of the entire situation around in the vehicle using the 4D approach to dynamic machine vision. Obstacles are detected and tracked both in the forward and in the backward viewing range up to about 100 meters distance; up to 5 objects may be tracked in parallel in each hemisphere. A fixation type viewing direction control with the capability of saccadic shifts for attention focusing has been developed. The overall system comprises about 5 dozen transputers T-222 (16-bit, for image processing and communication) and T-800 (32-bit, for number crunching and knowledge processing) plus a PC as transputer host. A description of the parallel processing architecture is given allowing frequent data driven bottom-up and model driven top-down integration steps for efficient and robust object tracking (4D approach).

  11. Opto-Acoustic Data Fusion for Supporting the Guidance of Remotely Operated Underwater Vehicles (ROVs)

    Science.gov (United States)

    Bruno, F.; Lagudi, A.; Ritacco, G.; Muzzupappa, M.; Guida, R.

    2015-04-01

    Remotely Operated underwater Vehicles (ROVs) play an important role in a number of operations conducted in shallow and deep water (e.g.: exploration, survey, intervention, etc.), in several application fields like marine science, offshore construction, and underwater archeology. ROVs are usually equipped with different imaging devices, both optical and acoustic. Optical sensors are able to generate better images in close range and clear water conditions, while acoustic systems are usually employed in long range acquisitions and do not suffer from the presence of turbidity, a well-known cause of coarser resolution and harder data extraction. In this work we describe the preliminary steps in the development of an opto-acoustic camera able to provide an on-line 3D reconstruction of the acquired scene. Taking full advantage of the benefits arising from the opto-acoustic data fusion techniques, the system was conceived as a support tool for ROV operators during the navigation in turbid waters, or in operations conducted by means of mechanical manipulators. The paper presents an overview of the device, an ad-hoc methodology for the extrinsic calibration of the system and a custom software developed to control the opto-acoustic camera and supply the operator with visual information.

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

    Directory of Open Access Journals (Sweden)

    Bongsob Song

    2014-01-01

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

  13. HYFLEX (Hypersonic Flight Experiment). Results of flight testing (Navigation, guidance and control of HYFLEX vehicle and actual reentry flight trajectory); Gokuchoonsoku hiko jikken (HYFLEX) ni tsuite. Hiko kekka wo chushin ni (koho yudo seigyo to jitsuhiko keiro)

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, K.; Takizawa, M. [National Aerospace Laboratory, Tokyo (Japan); Ishimoto, S.; Morito, T. [National Space Development Agency of Japan, Tokyo (Japan); Tsujioka, M.; Shimura, K. [Mitsubishi Heavy Industries, Ltd., Tokyo (Japan)

    1997-11-05

    The HYFLEX vehicle is the first reentry testing vehicle with an airframe generating lift in Japan. Establishment of guidance and control technology is one of the purposes. For the design of flight trajectory, in order to satisfy the constraint of J-1 rocket during launching and the heat resistance performance of HYFLEX, the altitude 110 km and ground speed 3.9 km/s were determined as an apogee condition of the reentry trajectory. For the trajectory design on the ground surface, were considered the insurance of radar tracking and telemetry transfer from the Ogasawara Tracking Station and the load reduction for development cost and attitude control system. The navigation, guidance and control system is composed of an inertia sensor unit, an on-board computer, and an on-board software (OBS). The attitude is controlled by the elevon at the rear end of airframe and the gas jet. The design requirements include an accuracy of flight trajectory and a stable flight by attitude control. In response to these requirements, OBS was divided into function units, i.e., navigation, guidance, and control, which were individually designed. The flight experiments were conducted as scheduled. 12 refs., 3 figs., 1 tab.

  14. Intelligent Autonomy for Unmanned Surface and Underwater Vehicles

    Science.gov (United States)

    Huntsberger, Terry; Woodward, Gail

    2011-01-01

    As the Autonomous Underwater Vehicle (AUV) and Autonomous Surface Vehicle (ASV) platforms mature in endurance and reliability, a natural evolution will occur towards longer, more remote autonomous missions. This evolution will require the development of key capabilities that allow these robotic systems to perform a high level of on-board decisionmaking, which would otherwise be performed by humanoperators. With more decision making capabilities, less a priori knowledge of the area of operations would be required, as these systems would be able to sense and adapt to changing environmental conditions, such as unknown topography, currents, obstructions, bays, harbors, islands, and river channels. Existing vehicle sensors would be dual-use; that is they would be utilized for the primary mission, which may be mapping or hydrographic reconnaissance; as well as for autonomous hazard avoidance, route planning, and bathymetric-based navigation. This paper describes a tightly integrated instantiation of an autonomous agent called CARACaS (Control Architecture for Robotic Agent Command and Sensing) developed at JPL (Jet Propulsion Laboratory) that was designed to address many of the issues for survivable ASV/AUV control and to provide adaptive mission capabilities. The results of some on-water tests with US Navy technology test platforms are also presented.

  15. 75 FR 18500 - Guidance on Improving EPA Review of Appalachian Surface Coal Mining Operations under the Clean...

    Science.gov (United States)

    2010-04-12

    ... AGENCY Guidance on Improving EPA Review of Appalachian Surface Coal Mining Operations under the Clean..., titled Improving EPA Review of Appalachian Surface Coal Mining Operations under the Clean Water Act... environmental review of Appalachian surface coal mining operations under the Clean Water Act,...

  16. Residential surface soil guidance values applied worldwide to the original 2001 Stockholm Convention POP pesticides.

    Science.gov (United States)

    Jennings, Aaron A; Li, Zijian

    2015-09-01

    Surface soil contamination is a worldwide problem. Many regulatory jurisdictions attempt to control human exposures with regulatory guidance values (RGVs) that specify a soil's maximum allowable concentration. Pesticides are important soil contaminants because of their intentional toxicity and widespread surface soil application. Worldwide, at least 174 regulatory jurisdictions from 54 United Nations member states have published more than 19,400 pesticide RGVs for at least 739 chemically unique pesticides. This manuscript examines the variability of the guidance values that are applied worldwide to the original 2001 Stockholm Convention persistent organic pollutants (POP) pesticides (Aldrin, Chlordane, DDT, Dieldrin, Endrin, Heptachlor, Mirex, and Toxaphene) for which at least 1667 RGVs have been promulgated. Results indicate that the spans of the RGVs applied to each of these pesticides vary from 6.1 orders of magnitude for Toxaphene to 10.0 orders of magnitude for Mirex. The distribution of values across these value spans resembles the distribution of lognormal random variables, but also contain non-random value clusters. Approximately 40% of all the POP RGVs fall within uncertainty bounds computed from the U.S. Environmental Protection Agency (USEPA) RGV cancer risk model. Another 22% of the values fall within uncertainty bounds computed from the USEPA's non-cancer risk model, but the cancer risk calculations yield the binding (lowest) value for all POP pesticides except Endrin. The results presented emphasize the continued need to rationalize the RGVs applied worldwide to important soil contaminants.

  17. Target Trailing With Safe Navigation for Maritime Autonomous Surface Vehicles

    Science.gov (United States)

    Wolf, Michael; Kuwata, Yoshiaki; Zarzhitsky, Dimitri V.

    2013-01-01

    This software implements a motion-planning module for a maritime autonomous surface vehicle (ASV). The module trails a given target while also avoiding static and dynamic surface hazards. When surface hazards are other moving boats, the motion planner must apply International Regulations for Avoiding Collisions at Sea (COLREGS). A key subset of these rules has been implemented in the software. In case contact with the target is lost, the software can receive and follow a "reacquisition route," provided by a complementary system, until the target is reacquired. The programmatic intention is that the trailed target is a submarine, although any mobile naval platform could serve as the target. The algorithmic approach to combining motion with a (possibly moving) goal location, while avoiding local hazards, may be applicable to robotic rovers, automated landing systems, and autonomous airships. The software operates in JPL s CARACaS (Control Architecture for Robotic Agent Command and Sensing) software architecture and relies on other modules for environmental perception data and information on the predicted detectability of the target, as well as the low-level interface to the boat controls.

  18. Radar-based collision avoidance for unmanned surface vehicles

    Science.gov (United States)

    Zhuang, Jia-yuan; Zhang, Lei; Zhao, Shi-qi; Cao, Jian; Wang, Bo; Sun, Han-bing

    2016-12-01

    Unmanned surface vehicles (USVs) have become a focus of research because of their extensive applications. To ensure safety and reliability and to perform complex tasks autonomously, USVs are required to possess accurate perception of the environment and effective collision avoidance capabilities. To achieve these, investigation into realtime marine radar target detection and autonomous collision avoidance technologies is required, aiming at solving the problems of noise jamming, uneven brightness, target loss, and blind areas in marine radar images. These technologies should also satisfy the requirements of real-time and reliability related to high navigation speeds of USVs. Therefore, this study developed an embedded collision avoidance system based on the marine radar, investigated a highly real-time target detection method which contains adaptive smoothing algorithm and robust segmentation algorithm, developed a stable and reliable dynamic local environment model to ensure the safety of USV navigation, and constructed a collision avoidance algorithm based on velocity obstacle (V-obstacle) which adjusts the USV's heading and speed in real-time. Sea trials results in multi-obstacle avoidance firstly demonstrate the effectiveness and efficiency of the proposed avoidance system, and then verify its great adaptability and relative stability when a USV sailing in a real and complex marine environment. The obtained results will improve the intelligent level of USV and guarantee the safety of USV independent sailing.

  19. Measurement of atmospheric surface layer turbulence using unmanned aerial vehicles

    Science.gov (United States)

    Witte, Brandon; Smith, Lorli; Schlagenhauf, Cornelia; Bailey, Sean

    2016-11-01

    We describe measurements of the turbulence within the atmospheric surface layer using highly instrumented and autonomous unmanned aerial vehicles (UAVs). Results from the CLOUDMAP measurement campaign in Stillwater Oklahoma are presented including turbulence statistics measured during the transition from stably stratified to convective conditions. The measurements were made using pre-fabricated fixed-wing remote-control aircraft adapted to fly autonomously and carry multi-hole pressure probes, pressure, temperature and humidity sensors. Two aircraft were flown simultaneously, with one flying a flight path intended to profile the boundary layer up to 100 m and the other flying at a constant fixed altitude of 50 m. The evolution of various turbulent statistics was determined from these flights, including Reynolds stresses, correlations, spectra and structure functions. These results were compared to those measured by a sonic anemometer located on a 7.5 m tower. This work was supported by the National Science Foundation through Grant #CBET-1351411 and by National Science Foundation award #1539070, Collaboration Leading Operational UAS Development for Meteorology and Atmospheric Physics (CLOUDMAP).

  20. Development of vehicle model test-bending of a simple structural surfaces model for automotive vehicle sedan

    Science.gov (United States)

    Nor, M. K. Mohd; Noordin, A.; Ruzali, M. F. S.; Hussen, M. H.; Mustapa@Othman, N.

    2017-04-01

    Simple Structural Surfaces (SSS) method is offered as a means of organizing the process for rationalizing the basic vehicle body structure load paths. The application of this simplified approach is highly beneficial in the development of modern passenger car structure design. In Malaysia, the SSS topic has been widely adopted and seems compulsory in various automotive programs related to automotive vehicle structures in many higher education institutions. However, there is no real physical model of SSS available to gain considerable insight and understanding into the function of each major subassembly in the whole vehicle structures. Based on this motivation, a real physical SSS of sedan model and the corresponding model vehicle tests of bending is proposed in this work. The proposed approach is relatively easy to understand as compared to Finite Element Method (FEM). The results prove that the proposed vehicle model test is useful to physically demonstrate the importance of providing continuous load path using the necessary structural components within the vehicle structures. It is clearly observed that the global bending stiffness reduce significantly when more panels are removed from the complete SSS model. The analysis shows the front parcel shelf is an important subassembly to sustain bending load.

  1. Multifunctional Inshore Survey Platform with Unmanned Surface Vehicles

    Directory of Open Access Journals (Sweden)

    Wen-Rong Yang

    2011-12-01

    Full Text Available Because of extreme weather and frequent natural disasters, improvement of disaster prevention capabilities and early warning technologies is an urgent matter. Inshore areas are where ocean and land intersect; the sea conditions and environment are complex and changeable, and human activities are frequent in these areas. Natural disasters, such as a substantial rise in sea levels, coastal erosion and transitions, and rapid flooding from tsunamis, and human development projects, pollution, and ecological damage must be thoroughly investigated, monitored, recorded, and prevented. The west coast of Taiwan, particularly the southeast coastal plain, is a highly populated narrow area; thus, field survey tools with a high degree of freedom and flexible applications are required for data collection to reach its full potential. The Taiwan Ocean Research Institute developed an unmanned surface vehicle (USV for the “Long Term Observation for Research Performed in TORI” 2010 project. This USV is a platform that integrates scientific equipment, including Wi-Fi communication and a satellite-based global positioning system (GPS with navigation images and signals, to form an internal network with onshore control bases to allow the instant acquisition of measured data and enable researchers to conduct surveys in safe conditions. USVs are appropriate for various types of inshore research and surveys, such as marine topography, sediment disposition analysis, inshore engineering measurements, and the monitoring of hydrology, water quality, and the environment. One aim of the Taiwan Ocean Research Institute (TORI is to establish a method to use the USV for collecting inshore marine topography, hydrology, water quality, and meteorological data. Integrating field investigations of Taiwan’s coastal waters will provide data for verifying numerical simulations and lead scientists to explore novel and unknown areas.

  2. Optimization of the Upper Surface of Hypersonic Vehicle Based on CFD Analysis

    Science.gov (United States)

    Gao, T. Y.; Cui, K.; Hu, S. C.; Wang, X. P.; Yang, G. W.

    2011-09-01

    For the hypersonic vehicle, the aerodynamic performance becomes more intensive. Therefore, it is a significant event to optimize the shape of the hypersonic vehicle to achieve the project demands. It is a key technology to promote the performance of the hypersonic vehicle with the method of shape optimization. Based on the existing vehicle, the optimization to the upper surface of the Simplified hypersonic vehicle was done to obtain a shape which suits the project demand. At the cruising condition, the upper surface was parameterized with the B-Spline curve method. The incremental parametric method and the reconstruction technology of the local mesh were applied here. The whole flow field was been calculated and the aerodynamic performance of the craft were obtained by the computational fluid dynamic (CFD) technology. Then the vehicle shape was optimized to achieve the maximum lift-drag ratio at attack angle 3°, 4° and 5°. The results will provide the reference for the practical design.

  3. Software Architecture for Anti-Submarine Warfare Unmanned Surface Vehicles

    Science.gov (United States)

    2016-09-01

    autonomous vehicles,” M.S.C. thesis, Dept. Elect. and Comput. Eng., Instituto Superior Tecnico , Lisbon, Portugal, 2009. [6] V. Berzins and Luqi...TOC.htm. [Accessed: 18 July 2016]. [9] Naval Meteorology and Oceanography Command, Fleet Oceanographic and Acoustic Reference Manual . Stennis Space

  4. Guidance on tiered risk assessment for plant protection products for aquatic organisms in edge-of-field surface waters

    Directory of Open Access Journals (Sweden)

    EFSA Panel on Plant Protection Products and their Residues (PPR

    2013-07-01

    Full Text Available EFSA’s Panel on Plant Protection Products and their Residues (PPR was tasked to revise the Guidance Document (GD on Aquatic Ecotoxicology under Council Directive 91/414/EEC (SANCO/3268/2001 rev.4 (final, 17 October 2002. This Guidance of the PPR Panel is the first of three requested deliverables within this mandate. It has its focus on tiered acute and chronic effect assessment schemes with detailed guidance on tier 1 and higher tier effect assessments for aquatic organisms in edge-of-field surface waters and on proposals regarding how to link effects to exposure estimates. The exposure assessment methodology was not reviewed and it is assumed that the current FOCUS surface water exposure assessment methodology will continue to be used for exposure assessment at EU level. The current GD is intended to be used for authorisation of active substances at EU level as well as for plant protection products at Member State level. The effect assessment schemes in this GD allow for the derivation of regulatory acceptable concentrations (RACs on the basis of two options: (1 the ecological threshold option (ETO, accepting negligible population effects only, and (2 the ecological recovery option (ERO, accepting some population-level effects if ecological recovery takes place within an acceptable time period. In the tiered effect assessment schemes, in principle, all tiers (1, 2 and 3 are able to address the ETO, while the model ecosystem approach (tier 3, under certain conditions, is able to also address the ERO. The GD provides the scientific background for the risk assessment to aquatic organisms in edge-of-field surface waters and is structured to give detailed guidance on all assessment steps. An executive summary joining all parts of the guidance and decision schemes in a concise way is provided and is intended to help applicants and regulatory authorities in day-to-day use.

  5. An incremental-learning-by-navigation approach to vision-based autonomous land vehicle guidance in indoor environments using vertical line information and multiweighted generalized Hough transform technique.

    Science.gov (United States)

    Chen, G Y; Tsai, W H

    1998-01-01

    An incremental learning by navigation approach to vision based autonomous land vehicle (ALV) guidance in indoor environments is proposed. The approach consists of three stages: initial learning, navigation, and model updating. In the initial learning stage, the ALV is driven manually, and environment images and other status data are recorded automatically. Then, an offline procedure is performed to build an initial environment model. In the navigation stage, the ALV moves along the learned environment automatically, locates itself by model matching, and records necessary information for model updating. In the model updating stage, an offline procedure is performed to refine the learned model. A more precise model is obtained after each navigation-and-update iteration. Used environment features are vertical straight lines in camera views. A multiweighted generalized Hough transform is proposed for model matching. A real ALV was used as the testbed, and successful navigation experiments show the feasibility of the proposed approach.

  6. 洛阳智慧停车诱导系统的设计与实现%The Design and Development of Luoyang Smart Vehicles Parking Guidance System

    Institute of Scientific and Technical Information of China (English)

    孟红玲; 张开广; 巴明廷; 孙艳敏; 张宇

    2013-01-01

    The authors discussed the contents of database,the guidance infrastructure,the methods and information for broadcasting,and system application in Luoyang Smart Vehicles Parking Guidance System(LYSVPGS). LYSVPGS is one of significant application functions in Smart Traffic System,and could supply timely precise information about the parking,export the optimum route for people traveling. It plays an important role in the redistribution of city traffic flow and the traffic cost saving.%主要讨论了支持洛阳市智慧停车诱导系统的数据库结构,诱导基础设施,信息发布内容与方法,以及系统的主要功能。洛阳市智慧停车诱导系统是洛阳智慧交通系统应用的重要组成部分,它为人们的出行提供实时、准确的停车信息以及到达目的地的最佳的行车路线,合理地引导城市车流,保障城市道路的畅通,节约人们的出行成本。

  7. Unmanned Surface Vehicle Human-Computer Interface for Amphibious Operations

    Science.gov (United States)

    2013-08-01

    FIGURES Figure 1. MOCU Baseline HCI using Both Aerial Photo and Digital Nautical Chart ( DNC ) Maps to Control and Monitor Land, Sea, and Air...Action DNC Digital Nautical Chart FNC Future Naval Capability HCI Human-Computer Interface HRI Human-Robot Interface HSI Human-Systems Integration...Digital Nautical Chart ( DNC ) Maps to Control and Monitor Land, Sea, and Air Vehicles. 3.2 BASELINE MOCU HCI The Baseline MOCU interface is a tiled

  8. Optimization of S-surface controller for autonomous underwater vehicle with immune-genetic algorithm

    Institute of Scientific and Technical Information of China (English)

    LI Ye; ZHANG Lei; WAN Lei; LIANG Xiao

    2008-01-01

    To deduce error and fussy work of manual adjustment of parameters for an S-surface controller in underwater vehicle motion control, the immune-genetic optimization of S-surface controller of an underwater vehicle was proposed. The ability of producing various antibodies for the immune algorithm, the self-adjustment of antibody density, and the antigen immune memory were used to realize the rapid convergence of S-surface controller parameters. It avoided loitering near the local peak value. Deduction of the S-surface controller was given. General process of the immune-genetic algorithm was described and immune-genetic optimization of S-surface controller parameters was discussed. Definitive results were obtained from many simulation experiments and lake experiments, which indicate that the algorithm can get good effect in optimizing the nonlinear motion controller parameters of an underwater vehicle.

  9. A small autonomous surface vehicle for ocean color remote sensing

    Digital Repository Service at National Institute of Oceanography (India)

    Desa, E.S.; Maurya, P.; Pereira, A.; Pascoal, A.M.; Desai, R.G.P.; Mascarenhas, A.A.M.Q.; Desa, E.; Madhan, R.; Matondkar, S.G.P.; Navelkar, G.S.; Prabhudesai, S.; Afzulpurkar, S.

    of ocean vehicles,” MIT, Cambridge, MA, NSF Sea Grant Project GH-1, 1969. [8] G. F. Franklin, J. D. Powell, and A. Emami-Naeini, Feedback Control of Dynamic Systems, 4th ed. Upper Saddle River, NJ: Pearson Edu- cation, Inc., 2002, pp. 173–179. [9] N. S..., Eds. London, U.K.: Institution of Engineering and Tech- nology, 2006, ch. 17, pp. 353–386. [13] C. Samson, “Path following and time-varying feedback stabilization of a wheeled mobile robot,” in Proc. Int. Conf. Control, Autom., Robot. Vis. (ICARCV...

  10. Data fusion control and guidance of surface-to-air missile under the complex circumstance based on neural-net technology

    Institute of Scientific and Technical Information of China (English)

    Zhou Deyun; Zhou Feng

    2008-01-01

    Under the complicated electromagnetism circumstance,the model of data fusion control and guidance of surface-to-air missile weapon systems is established.Such ways and theories as Elman-NN,radar tracking and niter's data fusion net based on the group method for data-processing (GMRDF) are applied to constructing the model of data fusion.The highly reliable state estimation of the tracking targets and the improvement in accuracy of control and guidance are obtained.The purpose is optimization design of data fusion control and guidance of surface-to-air missile weapon systems and improving the fighting effectiveness of surface-to-air missile weapon systems.

  11. Nerve guidance conduits from aligned nanofibers: improvement of nerve regeneration through longitudinal nanogrooves on a fiber surface.

    Science.gov (United States)

    Huang, Chen; Ouyang, Yuanming; Niu, Haitao; He, Nanfei; Ke, Qinfei; Jin, Xiangyu; Li, Dawei; Fang, Jun; Liu, Wanjun; Fan, Cunyi; Lin, Tong

    2015-04-08

    A novel fibrous conduit consisting of well-aligned nanofibers with longitudinal nanogrooves on the fiber surface was prepared by electrospinning and was subjected to an in vivo nerve regeneration study on rats using a sciatic nerve injury model. For comparison, a fibrous conduit having a similar fiber alignment structure without surface groove and an autograft were also conducted in the same test. The electrophysiological, walking track, gastrocnemius muscle, triple-immunofluorescence, and immunohistological analyses indicated that grooved fibers effectively improved sciatic nerve regeneration. This is mainly attributed to the highly ordered secondary structure formed by surface grooves and an increase in the specific surface area. Fibrous conduits made of longitudinally aligned nanofibers with longitudinal nanogrooves on the fiber surface may offer a new nerve guidance conduit for peripheral nerve repair and regeneration.

  12. A control strategy for steering an autonomous surface sailing vehicle in a tacking maneuver

    OpenAIRE

    2009-01-01

    Sailing vessels such as sailboats but also landyachts are vehicles representing a real challenge for automation. However, the control aspects of such vehicles were hitherto very little studied. This paper presents a simplied dynamic model of a so-called landyacht allowing to capture the main elements of the behavior of surface sailing vessels. We then propose a path generation scheme and a controller design for a well-known and fundamental maneuver in sailing referred to as tacking. Simulatio...

  13. Multiple pole electromagnetic propulsion system with separated ballistic guidance and electrical current contact surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Sims, Jr., James R. (Los Alamos, NM)

    2008-07-15

    An electromagnetic propulsion system is disclosed having separate rails for ballistic guidance and for carrying current. In this system, one or more pairs of ballistic guidance rails are provided, with each ballistic guidance rail having a pair of current carrying rails joined to it to form a combined rail. Each combined rail is separated electrically from adjacent combined rails by electrically insulating blocks. Each of the current carrying rails in a given combined rail pair have the same electrical polarity, and the polarities alternate between adjacent combined rails. Armatures contact current carrying rails to complete the circuit to generate the accelerating Lorentz force on the armatures. Bore riders on the sabot and/or projectile are in contact with the ballistic guide rails. Separation of the current carrying and ballistic guidance functions increases resistance of the system to rail movement and bending, as well as reduced wear/damage to the rails. In further embodiments, a circumferential over wrap providing compressive force on the rails further increases resistance of the system to rail movement and bending.

  14. Worldwide Regulatory Guidance Values Applied to Direct Contact Surface Soil Pesticide Contamination: Part I—Carcinogenic Pesticides

    Directory of Open Access Journals (Sweden)

    Aaron A Jennings

    2017-06-01

    Full Text Available Regulatory agencies worldwide have developed regulatory guidance values (RGVs for nearly 800 pesticides. Analysis of the residential surface soil guidance values applied to the most frequently regulated current-use agriculture, home, and garden pesticides is presented. Part I concentrates on values applied to atrazine, simazine, and trifluralin. These are unique among commonly used pesticides because they are generally considered to be human carcinogens. Their use has been banned in much of the world, but they are commonly used in the United States. Regulatory guidance values applied to these 3 pesticides vary by 8.6, 5.5, and 5.1 orders of magnitude. Risk model coefficient–bounded set uncertainty analysis is applied to help analyze this variability. Cancer risk model uncertainty bounds appear to contain 36.3%, 43.0%, and 49.5% of the RGVs. Most of the remaining values appear to exceed a lifetime cancer incidence risk of 1 × 10 −6 and may not be adequately protective of human health.

  15. Simulating the Effects of Surface Roughness on Reinforced Concrete T Beam Bridge under Single and Multiple Vehicles

    Directory of Open Access Journals (Sweden)

    Rahul Kalyankar

    2016-01-01

    Full Text Available This research focuses on the application of the spatial system of finite element modeling for the vehicle-bridge interaction on reinforced concrete US Girder Bridge in order to obtain the effect of surface roughness. Single vehicle and multiple vehicles on reinforced concrete T beam bridge were studied with variable surface roughness profiles. The effects of six different surface roughness profiles (very good, good, measured, average, poor, and very poor were investigated for vehicle-bridge interaction. The values of the Dynamic Amplification Factor (DAF were obtained for single and multiple vehicles on T Beam Bridge for different surface roughness profiles, along with the distances between the axles of heavy vehicle. It was observed that when the bridge has very good, good, measured, and average surface roughness, the DAF values for the single vehicle over the bridge were observed to be within acceptable limits specified by AASHTO. However, for the bridge with multiple vehicles only very good and measured surface roughness profiles showed a DAF and vehicle axle distances within the acceptable limits. From the current studies, it was observed that the spatial system showed reliable responses for predicting the behavior of the bridge under variable road surface roughness conditions and was reliable in vehicle axle detection, and therefore, it has a potential to be use for realistic simulations.

  16. Accuracy Evaluation of a 3-Dimensional Surface Imaging System for Guidance in Deep-Inspiration Breath-Hold Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Alderliesten, Tanja; Sonke, Jan-Jakob; Betgen, Anja; Honnef, Joeri; Vliet-Vroegindeweij, Corine van [Department of Radiation Oncology, The Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam (Netherlands); Remeijer, Peter, E-mail: p.remeijer@nki.nl [Department of Radiation Oncology, The Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam (Netherlands)

    2013-02-01

    Purpose: To investigate the applicability of 3-dimensional (3D) surface imaging for image guidance in deep-inspiration breath-hold radiation therapy (DIBH-RT) for patients with left-sided breast cancer. For this purpose, setup data based on captured 3D surfaces was compared with setup data based on cone beam computed tomography (CBCT). Methods and Materials: Twenty patients treated with DIBH-RT after breast-conserving surgery (BCS) were included. Before the start of treatment, each patient underwent a breath-hold CT scan for planning purposes. During treatment, dose delivery was preceded by setup verification using CBCT of the left breast. 3D surfaces were captured by a surface imaging system concurrently with the CBCT scan. Retrospectively, surface registrations were performed for CBCT to CT and for a captured 3D surface to CT. The resulting setup errors were compared with linear regression analysis. For the differences between setup errors, group mean, systematic error, random error, and 95% limits of agreement were calculated. Furthermore, receiver operating characteristic (ROC) analysis was performed. Results: Good correlation between setup errors was found: R{sup 2}=0.70, 0.90, 0.82 in left-right, craniocaudal, and anterior-posterior directions, respectively. Systematic errors were {<=}0.17 cm in all directions. Random errors were {<=}0.15 cm. The limits of agreement were -0.34-0.48, -0.42-0.39, and -0.52-0.23 cm in left-right, craniocaudal, and anterior-posterior directions, respectively. ROC analysis showed that a threshold between 0.4 and 0.8 cm corresponds to promising true positive rates (0.78-0.95) and false positive rates (0.12-0.28). Conclusions: The results support the application of 3D surface imaging for image guidance in DIBH-RT after BCS.

  17. Development of Response Surface Models for Rapid Analysis & Multidisciplinary Optimization of Launch Vehicle Design Concepts

    Science.gov (United States)

    Unal, Resit

    1999-01-01

    Multdisciplinary design optimization (MDO) is an important step in the design and evaluation of launch vehicles, since it has a significant impact on performance and lifecycle cost. The objective in MDO is to search the design space to determine the values of design parameters that optimize the performance characteristics subject to system constraints. Vehicle Analysis Branch (VAB) at NASA Langley Research Center has computerized analysis tools in many of the disciplines required for the design and analysis of launch vehicles. Vehicle performance characteristics can be determined by the use of these computerized analysis tools. The next step is to optimize the system performance characteristics subject to multidisciplinary constraints. However, most of the complex sizing and performance evaluation codes used for launch vehicle design are stand-alone tools, operated by disciplinary experts. They are, in general, difficult to integrate and use directly for MDO. An alternative has been to utilize response surface methodology (RSM) to obtain polynomial models that approximate the functional relationships between performance characteristics and design variables. These approximation models, called response surface models, are then used to integrate the disciplines using mathematical programming methods for efficient system level design analysis, MDO and fast sensitivity simulations. A second-order response surface model of the form given has been commonly used in RSM since in many cases it can provide an adequate approximation especially if the region of interest is sufficiently limited.

  18. Method and System for Weakening Shock Wave Strength at Leading Edge Surfaces of Vehicle in Supersonic Atmospheric Flight

    Science.gov (United States)

    Daso, Endwell O. (Inventor); Pritchett, Victor E., II (Inventor); Wang, Ten-See (Inventor); Farr, Rebecca Ann (Inventor); Auslender, Aaron Howard (Inventor); Blankson, Isaiah M. (Inventor); Plotkin, Kenneth J. (Inventor)

    2015-01-01

    A method and system are provided to weaken shock wave strength at leading edge surfaces of a vehicle in atmospheric flight. One or more flight-related attribute sensed along a vehicle's outer mold line are used to control the injection of a non-heated, non-plasma-producing gas into a local external flowfield of the vehicle from at least one leading-edge surface location along the vehicle's outer mold line. Pressure and/or mass flow rate of the gas so-injected is adjusted in order to cause a Rankine-Hugoniot Jump Condition along the vehicle's outer mold line to be violated.

  19. Water level observations from Unmanned Aerial Vehicles for improving estimates of surface water-groundwater interaction

    DEFF Research Database (Denmark)

    Bandini, Filippo; Butts, Michael; Vammen Jacobsen, Torsten

    2017-01-01

    . However, traditional river gauging stations are normally spaced too far apart to capture spatial patterns in the water surface, while spaceborne observations have limited spatial and temporal resolution. UAVs (Unmanned Aerial Vehicles) can retrieve river water level measurements, providing: i) high...

  20. Speed Tracking Control of a Vehicle Robot Driver System Using Multiple Sliding Surface Control Schemes

    Directory of Open Access Journals (Sweden)

    Gang Chen

    2013-02-01

    Full Text Available To overcome the drawbacks of using a traditional proportional-integral-derivative (PID control method for a robot driver system, such as requiring preliminary offline learning, big overshoot and large speed fluctuation, a new method for speed tracking of a robot driver system based on sliding mode control is proposed in this paper. Firstly, the coordinated control model of multiple manipulators for the robot driver is built, which achieved coordinated control of the throttle mechanical leg, clutch mechanical leg, brake mechanical leg and shift mechanical arm for the robot driver. On the basis of this, a speed tracking sliding mode controller for a vehicle robot driver is designed using the method of multiple sliding surfaces design, and the variable structure control laws of throttle and brake are designed respectively, which realize the speed tracking of the given driving test cycle. Experimental results demonstrate that compared with the PID control method, the proposed method can obviously reduce the overshoot of vehicle speed tracking control and greatly improve the accuracy of vehicle speed tracking. The vehicle speed tracking accuracy stays within a tolerance band of ±2 km/h, which meets the requirements of national vehicle test standards. Furthermore, the action of the speed tracking control in the same driving test cycle using the proposed method is consistent, so that the robot driver has good repeatability. Therefore, it can ensure the effectiveness of the vehicle emission test.

  1. Heat pipe and surface mass transfer cooling of hypersonic vehicle structures

    Science.gov (United States)

    Colwell, Gene T.; Modlin, James M.

    1992-01-01

    The problem of determining the feasibility of cooling hypersonic vehicle leading-edge structures exposed to severe aerodynamic surface heating using heat pipe and mass transfer cooling techniques is addressed. A description is presented of a numerical finite-difference-based hypersonic leading-edge cooling model incorporating poststartup liquid metal heat pipe cooling with surface transpiration and film cooling to predict the transient structural temperature distributions and maximum surface temperatures of hypersonic vehicle leading edge. An application of this model to the transient cooling of a typical aerospace plane wing leading-edge section. The results of this application indicated that liquid metal heat pipe cooling alone is insufficient to maintain surface temperatures below an assumed maximum level of 1800 K for about one-third of a typical aerospace plane ascent trajectory through the earth's atmosphere.

  2. GUIDANCE FOR THE PROPER CHARACTERIZATION AND CLASSIFICATION OF LOW SPECIFIC ACTIVITY MATERIALS AND SURFACE CONTAMINATED OBJECTS FOR DISPOSAL

    Energy Technology Data Exchange (ETDEWEB)

    PORTSMOUTH JH; BLACKFORD LT

    2012-02-13

    Regulatory concerns over the proper characterization of certain waste streams led CH2M HILL Plateau Remediation Company (CHPRC) to develop written guidance for personnel involved in Decontamination & Decommissioning (D&D) activities, facility management and Waste Management Representatives (WMRs) involved in the designation of wastes for disposal on and off the Hanford Site. It is essential that these waste streams regularly encountered in D&D operations are properly designated, characterized and classified prior to shipment to a Treatment, Storage or Disposal Facility (TSDF). Shipments of waste determined by the classification process as Low Specific Activity (LSA) or Surface Contaminated Objects (SCO) must also be compliant with all applicable U.S. Department of Transportation (DOE) regulations as well as Department of Energy (DOE) orders. The compliant shipment of these waste commodities is critical to the Hanford Central Plateau cleanup mission. Due to previous problems and concerns from DOE assessments, CHPRC internal critiques as well as DOT, a management decision was made to develop written guidance and procedures to assist CHPRC shippers and facility personnel in the proper classification of D&D waste materials as either LSA or SCO. The guidance provides a uniform methodology for the collection and documentation required to effectively characterize, classify and identify candidate materials for shipping operations. A primary focus is to ensure that waste materials generated from D&D and facility operations are compliant with the DOT regulations when packaged for shipment. At times this can be difficult as the current DOT regulations relative to the shipment of LSA and SCO materials are often not clear to waste generators. Guidance is often sought from NUREG 1608/RAMREG-003 [3]: a guidance document that was jointly developed by the DOT and the Nuclear Regulatory Commission (NRC) and published in 1998. However, NUREG 1608 [3] is now thirteen years old and

  3. INVESTIGATION OF VEHICLE IMPACT FORCE ON BRIDGE WITH ROUGH RIDING SURFACE

    Directory of Open Access Journals (Sweden)

    O. L. Verbitskaya

    2014-01-01

    Full Text Available Nowadays heavy vehicles constitute a considerable volume in the transportation flow on the territory of the Republic of Belarus and bridge inequalities significantly increase a load on their bearing elements and cause a vibration in bridge superstructures. This leads to rapid wear and reduction in time between bridge repairs. The given problem has been insufficiently studied and it is considered as an actual one. Revision of analytical models is required in order to make prediction and evaluation of bridge structure wear. These models must take into account a dynamic impact of heavy vehicles caused by their movement on bridge rough riding surface.The purpose of scientific investigations is to develop a dynamic interactional model of a vehicle and a bridge plate. The paper proposes such dynamic model that permits to investigate impact forces of a heavy vehicle on bridge superstructures which have been initiated by bridge traffic-way inequalities. Weight of an vehicle and plate, rigidity and viscous damping of vehicle suspensions, a plate and piers have been taken into account while making the required calculations.An analysis of free oscillatory motions of the plate and vehicle have been carried out with due account of viscous damping. A dynamic interactional calculation for a vehicle and a plate has been made in the paper. Character of plate oscillatory motions has been determined at various parameters of the dynamic model. In this case non-linearity of reinforced concrete plate deformation has been taken into account and its calculation has been executed in accordance with the norms of the Republic of Belarus. The calculations have made it possible to obtain dynamic interaction coefficients of front axle wheels and bridge plate at various bench heights and also investigate its influence on maximum bending moments in plate sections.

  4. Catalytic surface effect on ceramic coatings for an aeroassisted orbital transfer vehicle

    Science.gov (United States)

    Steward, D. A.; Leiser, D. B.

    1984-01-01

    Surface catalytic efficiencies of glassy coatings were determined from a reaction boundary layer computation and arc-jet data. The catalytic efficiencies of the various coatings examined are discussed in terms of their reaction-rate constants. These constants are a function of the wall temperature (1290 K to 2000 K). In addition, the advantage of a thermal protection system for a bent biconic, aeroassisted orbital transfer vehicle with a low surface catalytic efficiency is discussed.

  5. Effect of surface catalycity on high-altitude aerothermodynamics of reentry vehicles

    Science.gov (United States)

    Molchanova, A. N.; Kashkovsky, A. V.; Bondar, Ye. A.

    2016-10-01

    This work is aimed at the development of surface chemistry models for the Direct Simulation Monte Carlo (DSMC) method applicable to non-equilibrium high-temperature flows about reentry vehicles. Probabilities of the surface processes dependent on individual properties of each particular molecule are determined from the macroscopic reaction rate data. Two different macroscopic finite rate sets are used for construction of DSMC surface recombination models. The models are implemented in the SMILE++ software system for DSMC computations. A comparison with available experimental data is performed. Effects of surface recombination on the aerothermodynamics of a blunt body at high-altitude reentry conditions are numerically studied with the DSMC method.

  6. Vehicle Emission Inspection and Maintenance (I/M) Provision in the Fixing America’s Surface Transportation (FAST) Act

    Science.gov (United States)

    This document is a memorandum regarding Vehicle Emission Inspection and Maintenance (I/M) Provision in Fixing America's Surface Transportation (FAST) Act, which provides long-term funding certainty for surface transportation infrastructure planning

  7. Terminal Sliding Mode Control with Unidirectional Auxiliary Surfaces for Hypersonic Vehicles Based on Adaptive Disturbance Observer

    Directory of Open Access Journals (Sweden)

    Naibao He

    2015-01-01

    Full Text Available A novel flight control scheme is proposed using the terminal sliding mode technique, unidirectional auxiliary surfaces and the disturbance observer model. These proposed dynamic attitude control systems can improve control performance of hypersonic vehicles despite uncertainties and external disturbances. The terminal attractor is employed to improve the convergence rate associated with the critical damping characteristics problem noted in short-period motions of hypersonic vehicles. The proposed robust attitude control scheme uses a dynamic terminal sliding mode with unidirectional auxiliary surfaces. The nonlinear disturbance observer is designed to estimate system uncertainties and external disturbances. The output of the disturbance observer aids the robust adaptive control scheme and improves robust attitude control performance. Finally, simulation results are presented to illustrate the effectiveness of the proposed terminal sliding mode with unidirectional auxiliary surfaces.

  8. 车载导航系统的市场渗透率仿真研究%Simulation on Route Guidance Benefit of In-Vehicle Navigation System

    Institute of Scientific and Technical Information of China (English)

    杨珍珍; 干宏程

    2012-01-01

    In-vehicle navigation system (1VNS) usually provides real-time traffic information to assist drivers to choose optimal routes. To explore the route guidance effect of IVNS' s market penetration rate to freeway networks, including traffic benefit and environment benefit, this paper uses macroscopic dynamic traffic network model to develop a simulation platform. It uses dynamic traffic assignment model to describe route guidance mechanism of the IVNS and adopts total waiting time and total time spend as traffic benefit indicator. The VT-Micro model is used to measure vehicle emissions and fuel consumption. Moreover, the study calculates the direct economic benefits in terms of air pollutant treatment cost saving and fuel consumption. Taking a network with two origins and two destinations as an example, the simulation shows that the IVNS can effectively equilibrium freeway network' s demand, improve freeway network efficiency, reduce mobile source emissions and create huge economic benefits. Market penetration rate is recommended to value from 0. 2 to 0. 3 in view of traffic benefits and environment benefits. This simulation system iseffective for designing and evaluating the IVNS. It also provides the basis for decision-making and references for relevant departments to improve the operational efficiency of traffic networks.%车载导航系统(IVNS)能提供实时有效交通信息辅助驾驶人选择最佳路径.为了探讨IVNS的市场渗透率对路网运行效益(交通效益和环境效益两方面)的影响,本文运用宏观动态交通网络模型METANET建立仿真平台,用反馈式动态交通分配模型描述IVNS路径诱导下驾驶人的行为,以总排队时间和总耗费时间作为交通效益评价指标,用反映速度—加速度关系的机动车排放和燃油消耗关系模型——VT-Micro模型计算机动车排放量和燃油消耗量,并用货币价值量化排放减少带来的直接经济效益(包括大气污染治理费用和燃油

  9. Dijkstra算法在GIS车辆诱导系统的优化实现%Efficient implementation of Dijkstra algorithm in vehicle route guidance system based on GIS

    Institute of Scientific and Technical Information of China (English)

    殷招伟; 戴文博; 钱俊彦

    2015-01-01

    The interdisciplinary application of intelligent transportation system comes into being just to meet people’s growing demand.The analysis of shortest path is the key problem in the application of VRGS (Vehicle Route Guidance System), the Dijkstra algorithm is the common algorithm to solve this problem effectively. Combined two-tree Dijkstra algorithm and multi-core and multi-threading technology, this paper optimizes and improves the traditional Dijkstra algorithm. And it discusses the application of the algorithm in VRGS.At last, this paper poves its practicality and efficiency by simulating the shortest path search process of Guilin.%为了满足人们日益增长的出行需求,跨学科的智能交通系统应运而生。最短路径分析是GIS车辆诱导系统应用的关键问题,Dijkstra 算法是解决该问题的常用算法。文章结合二树 Dijkstra 算法的思想和现代多核多线程的技术,对 Dijkstra算法进行了优化与改进,并对该算法在车辆诱导系统中的应用进行了探讨。该系统以桂林市为例模拟了最短路径搜过程,证明该算法的高效性和实用性。

  10. Adaptive neural control for cooperative path following of marine surface vehicles: state and output feedback

    Science.gov (United States)

    Wang, H.; Wang, D.; Peng, Z. H.

    2016-01-01

    This paper addresses the cooperative path-following problem of multiple marine surface vehicles subject to dynamical uncertainties and ocean disturbances induced by unknown wind, wave and ocean current. The control design falls neatly into two parts. One is to steer individual marine surface vehicle to track a predefined path and the other is to synchronise the along-path speed and path variables under the constraints of an underlying communication network. Within these two formulations, a robust adaptive path-following controller is first designed for individual vehicles based on backstepping and neural network techniques. Then, a decentralised synchronisation control law is derived by means of consensus on along-path speed and path variables based on graph theory. The distinct feature of this design lies in that synchronised path following can be reached for any undirected connected communication graphs without accurate knowledge of the model. This result is further extended to the output feedback case, where an observer-based cooperative path-following controller is developed without measuring the velocity of each vehicle. For both designs, rigorous theoretical analysis demonstrate that all signals in the closed-loop system are semi-global uniformly ultimately bounded. Simulation results validate the performance and robustness improvement of the proposed strategy.

  11. Estimation of Supersonic Stage Separation Aerodynamics of Winged-Body Launch Vehicles Using Response Surface Methods

    Science.gov (United States)

    Erickson, Gary E.

    2010-01-01

    Response surface methodology was used to estimate the longitudinal stage separation aerodynamic characteristics of a generic, bimese, winged multi-stage launch vehicle configuration at supersonic speeds in the NASA LaRC Unitary Plan Wind Tunnel. The Mach 3 staging was dominated by shock wave interactions between the orbiter and booster vehicles throughout the relative spatial locations of interest. The inference space was partitioned into several contiguous regions within which the separation aerodynamics were presumed to be well-behaved and estimable using central composite designs capable of fitting full second-order response functions. The underlying aerodynamic response surfaces of the booster vehicle in belly-to-belly proximity to the orbiter vehicle were estimated using piecewise-continuous lower-order polynomial functions. The quality of fit and prediction capabilities of the empirical models were assessed in detail, and the issue of subspace boundary discontinuities was addressed. Augmenting the central composite designs to full third-order using computer-generated D-optimality criteria was evaluated. The usefulness of central composite designs, the subspace sizing, and the practicality of fitting lower-order response functions over a partitioned inference space dominated by highly nonlinear and possibly discontinuous shock-induced aerodynamics are discussed.

  12. Topics in Guided Motion Control of Marine Vehicles

    OpenAIRE

    Breivik, Morten

    2010-01-01

    A mix between a monograph and an article collection, this PhD thesis considers the concept of guided motion control for marine vehicles, in particular focusing on underactuated marine surface vehicles. The motion control scheme is defined to involve the combination of a guidance system which issues meaningful velocity commands with a velocity control system which has been specifically designed to take vehicle maneuverability and agility constraints into account when fulfilling these commands ...

  13. Safety Guidance System of Vehicles on Crosswind Highways%横风公路行车安全引导系统

    Institute of Scientific and Technical Information of China (English)

    韩宝睿; 范伟康; 宋越; 刘柯利; 吴诚

    2015-01-01

    The crosswind on highways has great impact on the safety of vehicle driving and usually leads to major malignant traffic accidents due to its suddenness and concealment , especially for the large and medium-sized passenger vans .At present, there isn’t any complete warning and control intelligent devices on the crosswind-prone sections in the domestic , and only some crosswind warning signs are set, which cannot meet the safety requirement of vehicle in crosswind weather .The research was carried out based on the speed limit model of vehicle safety on crosswind highways .In this model, several sensors were set up to acquire the data of wind speed and wind direction by real-time measurement and transmit them to ARM to get further analysis by Zigbee .Then, the analytical results were displayed on a deployment module that consists of variable message signs .By applying this model , we can achieve greater safety when driving on highways in crosswind weather condition .In this paper , a complete safety guidance system is established for crowss-wind on highway from the perspective of practical application .And the system is low cost , intelligent sensitive , working normally un-der night and different weather conditions .So it has good system expansibility and market extension .%公路上横风由于其突发性和隐蔽性,对车辆行车安全性有较大影响,对大、中型客车等厢式车辆影响尤为突出,常导致重大恶性交通事故。目前国内在横风多发路段并无完备的横风预警与控制方面的智能设备,仅仅通过设置橫风标志牌以警示驾驶人,无法满足车辆在横风天气下的安全行驶。本研究以横风公路行车安全限速模型为基础,建立一个通过风速、风向传感器等实时测量和数据采集,经Zigbee通信传输至中心ARM处理器进行分析处理,再由可变信息板等组成的发布模块对结果进行发布的横风公路行车安全引导系统,以提高公

  14. Driver behaviour data linked with vehicle, weather, road surface, and daylight data.

    Science.gov (United States)

    Hjelkrem, Odd André; Ryeng, Eirin Olaussen

    2017-02-01

    In this data set, vehicle observations have been linked to data containing weather and road surface conditions. A total of 311 908 observations are collected and classified in categories of precipitation type, road status information, and daylight condition. The data is collected for a long period of time, so that several different weather situations are present, ranging from dry summer to adverse winter weather conditions.

  15. Numerical Validation of a Near-Field Fugitive Dust Model for Vehicles Moving on Unpaved Surfaces

    Science.gov (United States)

    2013-09-25

    unpaved surfaces X-L. Tong ∗ Center for Advanced Vehicular Systems, Mississippi State University Simcenter/CAVS, 2 Research Blvd, Starkville, MS ...ORGANIZATION NAME(S) AND ADDRESS(ES) Center for Advanced Vehicular Systems,,Mississippi State University,Simcenter/CAVS, 2 Research Blvd,,Starkville,, MS ...8217 // ’ f I I I - cross wind (90 degree) -- 45 degree wind vehicle traveling time (s) - cross wind (90 degree) -- 45 degree wind QOL

  16. Nanoengineered surfaces for focal adhesion guidance trigger mesenchymal stem cell self-organization and tenogenesis.

    Science.gov (United States)

    Iannone, Maria; Ventre, Maurizio; Formisano, Lucia; Casalino, Laura; Patriarca, Eduardo J; Netti, Paolo A

    2015-03-11

    The initial conditions for morphogenesis trigger a cascade of events that ultimately dictate structure and functions of tissues and organs. Here we report that surface nanopatterning can control the initial assembly of focal adhesions, hence guiding human mesenchymal stem cells (hMSCs) through the process of self-organization and differentiation. This process self-sustains, leading to the development of macroscopic tissues with molecular profiles and microarchitecture reminiscent of embryonic tendons. Therefore, material surfaces can be in principle engineered to set off the hMSC program toward tissuegenesis in a deterministic manner by providing adequate sets of initial environmental conditions.

  17. Guidance manual on the estimation of airborne asbestos concentrations as a function of distance from a contaminated surface area for area suspension evaluations

    Energy Technology Data Exchange (ETDEWEB)

    Stenner, R.D.; Droppo, J.G.; Peloquin, R.A.; Bienert, R.W.; VanHouten, N.C.

    1990-04-01

    This Guidance Manual provides a quantitative approach for estimating the airborne concentrations of asbestos from disturbed soils and surfaces. Asbestos-containing surfaces may include roads surfaced with asbestos-bearing serpentine rock, tailings piles, and landfills. This manual identifies the procedures necessary for estimating airborne concentrations of asbestos in disturbed soils. The manual is to be used in conjunction with the Airborne Asbestos Concentration Estimator System-Area Suspension (AACES-AS) computer code. 44 refs., 16 figs., 7 tabs.

  18. Adaptive Sliding Mode Control Method Based on Nonlinear Integral Sliding Surface for Agricultural Vehicle Steering Control

    Directory of Open Access Journals (Sweden)

    Taochang Li

    2014-01-01

    Full Text Available Automatic steering control is the key factor and essential condition in the realization of the automatic navigation control of agricultural vehicles. In order to get satisfactory steering control performance, an adaptive sliding mode control method based on a nonlinear integral sliding surface is proposed in this paper for agricultural vehicle steering control. First, the vehicle steering system is modeled as a second-order mathematic model; the system uncertainties and unmodeled dynamics as well as the external disturbances are regarded as the equivalent disturbances satisfying a certain boundary. Second, a transient process of the desired system response is constructed in each navigation control period. Based on the transient process, a nonlinear integral sliding surface is designed. Then the corresponding sliding mode control law is proposed to guarantee the fast response characteristics with no overshoot in the closed-loop steering control system. Meanwhile, the switching gain of sliding mode control is adaptively adjusted to alleviate the control input chattering by using the fuzzy control method. Finally, the effectiveness and the superiority of the proposed method are verified by a series of simulation and actual steering control experiments.

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

    Science.gov (United States)

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

    2016-01-01

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

  20. Microfabrication, surface modification, and laser guidance techniques to create a neuron biochip

    Institute of Scientific and Technical Information of China (English)

    Russell Kirk Pirlo; Xiang Peng; Xiaocong Yuan; Bruce Zhi Gao

    2008-01-01

    In this report we illustrate our application of soft lithography-based microfabrication, surface modification, and our unique laser cell-patterning system toward the creation of neuron biochips. We deposited individual forebrain neurons from Day 7 embryonic chicks into two rows of eight in a silicon microstructure aligned over a microelectrode array (MEA). The polydimethylsiloxane (PDMS) membrane with microstructures to confine cells and guide network connectivity was aligned to the electrodes ofa MEA. Both the MEA and the PDMS membrane were treated with O2 plasma, Poly-L-Lysine, and Laminin to aid in cell attachment and survival. The primary advantage of our process is that it is quicker and simpler than previous cell-placement methods and may make highly defined neuronal network biochips more practical

  1. Design, development, and evaluation of an automatic guidance system for tractor tracking along the contour line on inclined surfaces

    Directory of Open Access Journals (Sweden)

    S Dehghani

    2016-04-01

    Full Text Available Introduction: Automatic guidance of tractors in the mechanized farming practice has taken the attention of agricultural engineers in the last two decades. For this to be truly practical on the farm, it should be economical, simple to operate and entirely contained on the vehicle. Different types of steering systems such as leader- cable, laser- controlled, radio- operated and contactor- type have been developed for automatic guidance. The automatic leveling system is used on hillside machines to keep the separator level when operating on hillsides. This system has three parts: fluid level system, electrical system and hydraulic system. The fluid level system consists of fluid reservoir and a leveling control switch box. The fluid level system actuates the electrical system of the leveling unit. The electrical system which actuated by the fluid system consist of four micro switches in the leveling control switch box, two micro switches in the limit control box, a solenoid in the hydraulic control level, manual leveling control switch, and a leveling limit warning light. The hydraulic system maintains the level of the separator when the machine is operating on a hillside. The present study was aimed to develop a reliable, versatile and easy to maintain system to fit our economy and low technology level of farmers for hillside- range development or fallow farming. The automatic guidance system has been implemented successfully on agricultural vehicles on the basis of three components, i.e. sensors, processors and actuator elements. The study site (N, latitude; E, longitude; and 1810 m above sea level was located at the Agricultural Research Center, Shiraz University, 15 km northwest of Shiraz, Fars Province, Iran. MF-399 agricultural tractor manufactured by ITMCO, Tabriz, Iran was used for doing the experiments. Materials and Methods:The Level Sensing System: The biaxial tilt industrial sensor (ZCT245AL- China with digital output can be connected

  2. The Effect of Metallic TPS Panel Bowing on the Surface Heating of the X-33 Vehicle

    Science.gov (United States)

    Palmer, Grant; Kontinos, Dean; Langhoff, Stephen R. (Technical Monitor)

    1997-01-01

    The thermal protection system of the windward surface of the X-33 vehicle consists of metallic honeycomb sandwich panels. Thermal gradients experienced during the descent phase of the trajectory result in a different rate of thermal expansion between the inner and outer face sheets of the metallic panels. This causes the panels to bow outward when the temperature of the outer face sheet is larger than that of the inner face sheet and inward when the temperature of the outer face sheet is less than that of he inner face sheet. This results in a quilted-type body surface. Using computational fluid dynamic analysis, this study will determine the effect the metallic TPS panel bowing has on the surface heating.

  3. Revision of Paschen's Law Relating to the ESD of Aerospace Vehicle Surfaces

    Science.gov (United States)

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

    2017-01-01

    The purpose of this work is to develop a version of Paschen's law that takes into account the flow of ambient gas past electrode surfaces. Paschen's law does not consider the flow of gas past an aerospace vehicle whose surfaces may be triboelectrically charged by dust or ice crystal impingement while traversing the atmosphere. The basic hypothesis of this work is that the number of electron-ion pairs created per unit distance between electrode surfaces is mitigated by the electron-ion pairs removed per unit distance by the flow of gas. The revised theoretical model must be a function of the mean velocity vxm of the ambient gas and reduce to Paschen's law when the mean velocity is zero. A new theoretical formulation of Paschen's law, taking into account the Mach number and compressible dynamic pressure, derived by the authors, will be discussed. This equation has been evaluated by wind tunnel experimentation. Initial data of the baseline wind tunnel experiments show results consistent with the hypothesis. This work may enhance the safety of aerospace vehicles through a redefinition of electrostatic launch commit criteria. It is also possible for new products, such as antistatic coatings, to be formulated based on this data.

  4. Unified Approach of Unmanned Surface Vehicle Navigation in Presence of Waves

    Directory of Open Access Journals (Sweden)

    Oren Gal

    2011-01-01

    Full Text Available Most of the present work for unmanned surface vehicle (USV navigation does not take into account environmental disturbances such as ocean waves, winds, and currents. In some scenarios, waves should be treated as special case of dynamic obstacle and can be critical to USV’s safety. For the first time, this paper presents unique concept facing this challenge by combining ocean waves' formulation with the probabilistic velocity obstacle (PVO method for autonomous navigation. A simple navigation algorithm is presented in order to apply the method of USV’s navigation in presence of waves. A planner simulation dealing with waves and obstacles avoidance is introduced.

  5. Research on Terminal Guidance for Re-Entry Vehicle Based on Second-Order Sliding Mode Control%基于二阶滑模的再入飞行器末制导律研究

    Institute of Scientific and Technical Information of China (English)

    窦荣斌; 张科

    2011-01-01

    A new robust terminal guidance law based on second-order sliding mode control is proposed for the problems existing in vehicle re-entry phase after starting of terminal guidance system, such as model uncertainty, complex aerodynamic conditions and constraint conditions for falling angle. Based on second-order variable structure control theory, a terminal guidance law with finite convergence time is designed; meanwhile, in order to weakening the influence of disturbance and chattering, a super-spiral algorithm is introduced for designing the second-order sliding mode terminal guidance law with finite convergence time and continuous control effect. Controlled by this guidance law, the angular rate of line-of-sight ( LOS) and constraint conditions for falling angle can converge quickly, thus ensuring higher guidance accuracy. Theoretic proof of stability based on Lyapunov theorem and simulation results show that the proposed guidance law is effective.%针对再入飞行过程中飞行器末制导启动后制导系统存在的模型不确定性因素以及气动环境复杂等鲁棒制导问题,结合落点角约束条件,提出一种基于二阶滑模的鲁棒末制导律设计方法.基于二阶滑模控制的思想,设计有限时间收敛的二阶滑模末制导律;为了消除有界的内外扰影响同时削弱抖振效果,引入超螺旋算法设计有限时间收敛的连续二阶滑模末制导律.飞行器在该末制导律导引下,弹目视线角速率及落角约束快速收敛,从而保证飞行器有很高的命中精度.基于Lyapunov定理的稳定性理论证明及仿真结果均表明了该末制导方案的有效性.

  6. Improved Re-Configurable Sliding Mode Controller for Reusable Launch Vehicle of Second Generation Addressing Aerodynamic Surface Failures and Thrust Deficiencies

    Science.gov (United States)

    Shtessel, Yuri B.

    2002-01-01

    In this report we present a time-varying sliding mode control (TV-SMC) technique for reusable launch vehicle (RLV) attitude control in ascent and entry flight phases. In ascent flight the guidance commands Euler roll, pitch and yaw angles, and in entry flight it commands the aerodynamic angles of bank, attack and sideslip. The controller employs a body rate inner loop and the attitude outer loop, which are separated in time-scale by the singular perturbation principle. The novelty of the TVSMC is that both the sliding surface and the boundary layer dynamics can be varied in real time using the PD-eigenvalue assignment technique. This salient feature is used to cope with control command saturation and integrator windup in the presence of severe disturbance or control effector failure, which enhances the robustness and fault tolerance of the controller. The TV-SMC is developed and tuned up for the X-33 sub-orbital technology demonstration vehicle in launch and re-entry modes. A variety of nominal, dispersion and failure scenarios have tested via high fidelity 6DOF simulations using MAVERIC/SLIM simulation software.

  7. 360-Degree Visual Detection and Target Tracking on an Autonomous Surface Vehicle

    Science.gov (United States)

    Wolf, Michael T; Assad, Christopher; Kuwata, Yoshiaki; Howard, Andrew; Aghazarian, Hrand; Zhu, David; Lu, Thomas; Trebi-Ollennu, Ashitey; Huntsberger, Terry

    2010-01-01

    This paper describes perception and planning systems of an autonomous sea surface vehicle (ASV) whose goal is to detect and track other vessels at medium to long ranges and execute responses to determine whether the vessel is adversarial. The Jet Propulsion Laboratory (JPL) has developed a tightly integrated system called CARACaS (Control Architecture for Robotic Agent Command and Sensing) that blends the sensing, planning, and behavior autonomy necessary for such missions. Two patrol scenarios are addressed here: one in which the ASV patrols a large harbor region and checks for vessels near a fixed asset on each pass and one in which the ASV circles a fixed asset and intercepts approaching vessels. This paper focuses on the ASV's central perception and situation awareness system, dubbed Surface Autonomous Visual Analysis and Tracking (SAVAnT), which receives images from an omnidirectional camera head, identifies objects of interest in these images, and probabilistically tracks the objects' presence over time, even as they may exist outside of the vehicle's sensor range. The integrated CARACaS/SAVAnT system has been implemented on U.S. Navy experimental ASVs and tested in on-water field demonstrations.

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

    Directory of Open Access Journals (Sweden)

    Fang Wang

    2017-05-01

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

  9. Surface (S)-layer proteins of Deinococcus radiodurans and their utility as vehicles for surface localization of functional proteins.

    Science.gov (United States)

    Misra, Chitra Seetharam; Basu, Bhakti; Apte, Shree Kumar

    2015-12-01

    The radiation resistant bacterium, Deinococcus radiodurans contains two major surface (S)-layer proteins, Hpi and SlpA. The Hpi protein was shown to (a) undergo specific in vivo cleavage, and (b) closely associate with the SlpA protein. Using a non-specific acid phosphatase from Salmonella enterica serovar Typhi, PhoN as a reporter, the Surface Layer Homology (SLH) domain of SlpA was shown to bind deinococcal peptidoglycan-containing cell wall sacculi. The association of SlpA with Hpi on one side and peptidoglycan on the other, localizes this protein in the 'interstitial' layer of the deinoccocal cell wall. Gene chimeras of hpi-phoN and slh-phoN were constructed to test efficacy of S-layer proteins, as vehicles for cell surface localization in D. radiodurans. The Hpi-PhoN protein localized exclusively in the membrane fraction, and displayed cell-based phosphatase activity in vivo. The SLH-PhoN, which localized to both cytosolic and membrane fractions, displayed in vitro activity but no cell-based in vivo activity. Hpi, therefore, emerged as an efficient surface localizing protein and can be exploited for suitable applications of this superbug.

  10. A guidance concept for hypersonic aerospacecrafts

    Science.gov (United States)

    Ishimoto, Shinji

    In this paper a guidance concept for hypersonic re-entry flights is presented. The method uses a closed-form guidance technique based on a drag acceleration reference profile. A guidance law for range control is developed. It employs a physical relation between vehicle energy and range instead of a prediction-correction technique used for Shuttle entry guidance. Simulation results show that the algorithm provides good performance.

  11. Guidance on tiered risk assessment for plant protection products for aquatic organisms in edge‐of‐field surface waters

    National Research Council Canada - National Science Library

    EFSA Panel on Plant Protection Products and their Residues (PPR)

    2013-01-01

    ...) on Aquatic Ecotoxicology under Council Directive 91/414/EEC (SANCO/3268/2001 rev.4 (final), 17 October 2002). This Guidance of the PPR Panel is the first of three requested deliverables within this mandate...

  12. A new surface catalytic model for silica-based thermal protection material for hypersonic vehicles

    Directory of Open Access Journals (Sweden)

    Li Kai

    2015-10-01

    Full Text Available Silica-based materials are widely employed in the thermal protection system for hypersonic vehicles, and the investigation of their catalytic characteristics is crucially important for accurate aerothermal heating prediction. By analyzing the disadvantages of Norman’s high and low temperature models, this paper combines the two models and proposes an eight-reaction combined surface catalytic model to describe the catalysis between oxygen and silica surface. Given proper evaluation of the parameters according to many references, the recombination coefficient obtained shows good agreement with experimental data. The catalytic mechanisms between oxygen and silica surface are then analyzed. Results show that with the increase of the wall temperature, the dominant reaction contributing to catalytic coefficient varies from Langmuir–Hinshelwood (LH recombination (TW  1350 K. The surface coverage of chemisorption areas varies evidently with the dominant reactions in the high temperature (HT range, while the surface coverage of physisorption areas varies within quite low temperature (LT range (TW < 250 K. Recommended evaluation of partial parameters is also given.

  13. A FMM-FFT accelerated hybrid volume surface integral equation solver for electromagnetic analysis of re-entry space vehicles

    KAUST Repository

    Yücel, Abdulkadir C.

    2014-07-01

    Space vehicles that re-enter the atmosphere often experience communication blackout. The blackout occurs when the vehicle becomes engulfed in plasma produced by interactions between the vehicle surface and the atmosphere. The plasma often is concentrated in a relatively thin shell around the vehicle, with higher densities near its nose than rear. A less structured, sometimes turbulent plasma wake often trails the vehicle. The plasma shell severely affects the performance of side-mounted antennas as it alters their characteristics (frequency response, gain patterns, axial ratio, and impedance) away from nominal, free-space values, sometimes entirely shielding the antenna from the outside world. The plasma plume/turbulent wake similarly affect the performance of antennas mounted at the back of the vehicle. The electromagnetic characteristics of the thin plasma shell and plume/turbulent wake heavily depend on the type of re-entry trajectory, the vehicle\\'s speed, angles of attack, and chemical composition, as well as environmental conditions. To analyze the antennas\\' performance during blackout and to design robust communication antennas, efficient and accurate simulation tools for charactering the antennas\\' performance along the trajectory are called for.

  14. Methods for estimating pressure and thermal loads induced by elevon deflections on hypersonic-vehicle surfaces with turbulent boundary layers

    Science.gov (United States)

    Kaufman, L. G., II; Johnson, C. B.

    1981-01-01

    Empirical anaytic methods are presented for calculating thermal and pressure distributions in three-dimensional, shock-wave turbulent-boundary-layer, interaction-flow regions on the surface of controllable hypersonic aircraft and missiles. The methods, based on several experimental investigations, are useful and reliable for estimating both the extent and magnitude of the increased thermal and pressure loads on the vehicle surfaces.

  15. Rapid 3D Modeling and Parts Recognition on Automotive Vehicles Using a Network of RGB-D Sensors for Robot Guidance

    OpenAIRE

    Alberto Chávez-Aragón; Rizwan Macknojia; Pierre Payeur; Robert Laganière

    2013-01-01

    This paper presents an approach for the automatic detection and fast 3D profiling of lateral body panels of vehicles. The work introduces a method to integrate raw streams from depth sensors in the task of 3D profiling and reconstruction and a methodology for the extrinsic calibration of a network of Kinect sensors. This sensing framework is intended for rapidly providing a robot with enough spatial information to interact with automobile panels using various tools. When a vehicle is position...

  16. Rapid 3D Modeling and Parts Recognition on Automotive Vehicles Using a Network of RGB-D Sensors for Robot Guidance

    Directory of Open Access Journals (Sweden)

    Alberto Chávez-Aragón

    2013-01-01

    Full Text Available This paper presents an approach for the automatic detection and fast 3D profiling of lateral body panels of vehicles. The work introduces a method to integrate raw streams from depth sensors in the task of 3D profiling and reconstruction and a methodology for the extrinsic calibration of a network of Kinect sensors. This sensing framework is intended for rapidly providing a robot with enough spatial information to interact with automobile panels using various tools. When a vehicle is positioned inside the defined scanning area, a collection of reference parts on the bodywork are automatically recognized from a mosaic of color images collected by a network of Kinect sensors distributed around the vehicle and a global frame of reference is set up. Sections of the depth information on one side of the vehicle are then collected, aligned, and merged into a global RGB-D model. Finally, a 3D triangular mesh modelling the body panels of the vehicle is automatically built. The approach has applications in the intelligent transportation industry, automated vehicle inspection, quality control, automatic car wash systems, automotive production lines, and scan alignment and interpretation.

  17. Reproducibility of crop surface maps extracted from Unmanned Aerial Vehicle (UAV) derived digital surface maps

    Science.gov (United States)

    Parkes, Stephen D.; McCabe, Matthew F.; Al-Mashhawari, Samir K.; Rosas, Jorge

    2016-10-01

    Crop height measured from UAVs fitted with commercially available RGB cameras provide an affordable alternative to retrieve field scale high resolution estimates. The study presents an assessment of between flight reproducibility of Crop Surface Maps (CSM) extracted from Digital Surface Maps (DSM) generated by Structure from Motion (SfM) algorithms. Flights were conducted over a centre pivot irrigation system covered with an alfalfa crop. An important step in calculating the absolute crop height from the UAV derived DSM is determining the height of the underlying terrain. Here we use automatic thresholding techniques applied to RGB vegetation index maps to classify vegetated and soil pixels. From interpolation of classified soil pixels, a terrain map is calculated and subtracted from the DSM. The influence of three different thresholding techniques on CSMs are investigated. Median Alfalfa crop heights determined with the different thresholding methods varied from 18cm for K means thresholding to 13cm for Otsu thresholding methods. Otsu thresholding also gave the smallest range of crop heights and K means thresholding the largest. Reproducibility of median crop heights between flight surveys was 4-6cm for all thresholding techniques. For the flight conducted later in the afternoon shadowing caused soil pixels to be classified as vegetation in key locations around the domain, leading to lower crop height estimates. The range of crop heights was similar for both flights using K means thresholding (35-36cm), local minimum thresholding depended on whether raw or normalised RGB intensities were used to calculate vegetation indices (30-35cm), while Otsu thresholding had a smaller range of heights and varied most between flights (26-30cm). This study showed that crop heights from multiple survey flights are comparable, however, they were dependent on the thresholding method applied to classify soil pixels and the time of day the flight was conducted.

  18. Reproducibility of crop surface maps extracted from Unmanned Aerial Vehicle (UAV) derived digital surface maps

    KAUST Repository

    Parkes, Stephen D.

    2016-10-25

    Crop height measured from UAVs fitted with commercially available RGB cameras provide an affordable alternative to retrieve field scale high resolution estimates. The study presents an assessment of between flight reproducibility of Crop Surface Maps (CSM) extracted from Digital Surface Maps (DSM) generated by Structure from Motion (SfM) algorithms. Flights were conducted over a centre pivot irrigation system covered with an alfalfa crop. An important step in calculating the absolute crop height from the UAV derived DSM is determining the height of the underlying terrain. Here we use automatic thresholding techniques applied to RGB vegetation index maps to classify vegetated and soil pixels. From interpolation of classified soil pixels, a terrain map is calculated and subtracted from the DSM. The influence of three different thresholding techniques on CSMs are investigated. Median Alfalfa crop heights determined with the different thresholding methods varied from 18cm for K means thresholding to 13cm for Otsu thresholding methods. Otsu thresholding also gave the smallest range of crop heights and K means thresholding the largest. Reproducibility of median crop heights between flight surveys was 4-6cm for all thresholding techniques. For the flight conducted later in the afternoon shadowing caused soil pixels to be classified as vegetation in key locations around the domain, leading to lower crop height estimates. The range of crop heights was similar for both flights using K means thresholding (35-36cm), local minimum thresholding depended on whether raw or normalised RGB intensities were used to calculate vegetation indices (30-35cm), while Otsu thresholding had a smaller range of heights and varied most between flights (26-30cm). This study showed that crop heights from multiple survey flights are comparable, however, they were dependent on the thresholding method applied to classify soil pixels and the time of day the flight was conducted.

  19. Fault-tolerant control with mixed aerodynamic surfaces and RCS jets for hypersonic reentry vehicles

    Directory of Open Access Journals (Sweden)

    Jingjing He

    2017-04-01

    Full Text Available This paper proposes a fault-tolerant strategy for hypersonic reentry vehicles with mixed aerodynamic surfaces and reaction control systems (RCS under external disturbances and subject to actuator faults. Aerodynamic surfaces are treated as the primary actuator in normal situations, and they are driven by a continuous quadratic programming (QP allocator to generate torque commanded by a nonlinear adaptive feedback control law. When aerodynamic surfaces encounter faults, they may not be able to provide sufficient torque as commanded, and RCS jets are activated to augment the aerodynamic surfaces to compensate for insufficient torque. Partial loss of effectiveness and stuck faults are considered in this paper, and observers are designed to detect and identify the faults. Based on the fault identification results, an RCS control allocator using integer linear programming (ILP techniques is designed to determine the optimal combination of activated RCS jets. By treating the RCS control allocator as a quantization element, closed-loop stability with both continuous and quantized inputs is analyzed. Simulation results verify the effectiveness of the proposed method.

  20. Development of a low-cost, unmanned surface vehicle for military applications

    Science.gov (United States)

    Cadena, A.

    2012-06-01

    This paper describes the development of an USV (Unmanned Surface Vehicle) prototype that serves as an educational platform and can be use for coastal patrol and operations in the jungle. The USV length is less than 2 m and range of 5000 m. It's composed by the following modules: propulsion, power, motor driver, CPU, sensor suite, camera system, communication and weapon system. The weapon system is formed by an experimental assault rifle and a rocket launcher with a fire control system. The assault rifle haven't got mechanical moving parts, the bullets (7.62x51mm round) are electronically ignited. The CPU is an FPGA development kit. The USV can be operate in remote mode or fully autonomous. Results of some systems from laboratory and sea trials are show.

  1. Initial position estimation strategy for a surface permanent magnet synchronous motor used in hybrid electric vehicles

    Institute of Scientific and Technical Information of China (English)

    Bing TIAN; Qun-tao AN; Li SUN‡; Dong-yang SUN; Jian-dong DUAN

    2016-01-01

    A novel nonlinear model for surface permanent magnet synchronous motors (SPMSMs) is adopted to estimate the initial rotor position for hybrid electric vehicles (HEVs). Usually, the accuracy of initial rotor position estimation for SPMSMs relies on magnetic saturation. To verify the saturation effect, the transient finite element analysis (FEA) model is presented first. Hybrid injection of a static voltage vector (SVV) superimposed with a high-frequency rotating voltage is proposed. The magnetic polarity is roughly identified with the aid of the saturation evaluation function, based on which an estimation of the position is performed. During this procedure, a special demodulation is suggested to extract signals of iron core saturation and rotor position. A Simulink/MATLAB platform for SPMSMs at standstill is constituted, and the effectiveness of the proposed strategy is verified. The proposed method is also validated by experimental results of an SPMSM drive.

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

    Institute of Scientific and Technical Information of China (English)

    廖煜雷; 张铭钧; 万磊; 李晔

    2016-01-01

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

  3. NO{sub x} removal from vehicle emissions by functionality surface of asphalt road

    Energy Technology Data Exchange (ETDEWEB)

    Chen Meng, E-mail: chenmeng623@126.com [College of Traffic, Northeast Forestry University, 26 Hexing Road, Harbin 150040 (China); Liu Yanhua, E-mail: liuyanhua815@126.com [College of Wildlife Resources, Northeast Forestry University, 26 Hexing Road, Harbin 150040 (China)

    2010-02-15

    This paper reported the potential of heterogeneous photocatalysis as an advanced oxidation technology for NO{sub x} removal from vehicle emissions by using TiO{sub 2} as a photocatalyst immobilized on the surface of asphalt road. Based on asphalt road material porous characteristic, we utilized permeability technology to make asphalt nano-TiO{sub 2} to be environmental protection materials. And then using scanning electron microscope, we observed the penetrating effect of TiO{sub 2}. The effect of surface friction, humidity and light intensity on NO{sub x} removal had been systematically investigated by the use of TiO{sub 2} immobilized on the surface of asphalt road as photocatalytic environmental protection materials. In addition, the decontaminating effect was tested by contrast test in TiO{sub 2} spraying section with non-spraying section, while the productions were used in road environment. Results of experiment revealed that decontaminating rate of the productions ranged from 6% to 12% this kind of photochemical catalysis environmental protection material has good environment purification function.

  4. NOx removal from vehicle emissions by functionality surface of asphalt road.

    Science.gov (United States)

    Chen, Meng; Liu, Yanhua

    2010-02-15

    This paper reported the potential of heterogeneous photocatalysis as an advanced oxidation technology for NO(x) removal from vehicle emissions by using TiO(2) as a photocatalyst immobilized on the surface of asphalt road. Based on asphalt road material porous characteristic, we utilized permeability technology to make asphalt nano-TiO(2) to be environmental protection materials. And then using scanning electron microscope, we observed the penetrating effect of TiO(2). The effect of surface friction, humidity and light intensity on NO(x) removal had been systematically investigated by the use of TiO(2) immobilized on the surface of asphalt road as photocatalytic environmental protection materials. In addition, the decontaminating effect was tested by contrast test in TiO(2) spraying section with non-spraying section, while the productions were used in road environment. Results of experiment revealed that decontaminating rate of the productions ranged from 6% to 12% this kind of photochemical catalysis environmental protection material has good environment purification function.

  5. Recent Events in Guidance, Navigation and Control

    Science.gov (United States)

    Polites, Michael E.; Bullman, Jack (Technical Monitor)

    2001-01-01

    This article summarizes recent events in Guidance, Navigation, and Control (GN&C) in space, weapons and missiles, and aircraft. The section on space includes recent developments with the following NASA spacecraft and space vehicles: Near Earth Asteroid Rendezvous, Deep Space 1, Microwave Anisotropy Probe, Earth Observer-1, Compton Gamma Ray Observatory, the International Space Station, X-38, and X-40A. The section on weapons and missiles includes recent developments with the following missiles: Joint Air-to-Surface Standoff Missile, Storm Shadow/Scalp EG precision standoff missile, Hellfire missile, AIM-120C Advanced medium-range air-to-air missile, Derby missile, Arrow 2, and the Standard Missile SM-3. The section on aircraft includes recent developments with the following aircraft: Joint Strike Fighter, X-31, V-22, Couger/SUDer Puma Mk. 2, Predator B 001, and the Unmanned Combat Air Vehicle.

  6. Agent Based Individual Traffic guidance

    DEFF Research Database (Denmark)

    Wanscher, Jørgen Bundgaard

    2004-01-01

    When working with traffic planning or guidance it is common practice to view the vehicles as a combined mass. >From this models are employed to specify the vehicle supply and demand for each region. As the models are complex and the calculations are equally demanding the regions and the detail...... can be obtained through cellular phone tracking or GPS systems. This information can then be used to provide individual traffic guidance as opposed to the mass information systems of today -- dynamic roadsigns and trafficradio. The goal is to achieve better usage of road and time. The main topic...

  7. Wear mechanism of heavy load friction contact pairs in tracked vehicle by combined ferrography and surface analysis

    Institute of Scientific and Technical Information of China (English)

    LI Li; ZHU You-li; HUANG Yuan-lin; XU Bin-shi; LI Xiao-yan

    2004-01-01

    Ferrography is deemed as one of the most effective methods for wear particle analysis and failure diagnosis. By analyzing the configuration, content and composition of wear particles in the lubricanting grease and the surface state of the worn surface with combined ferrography and surface analysis techniques, the wear mechanism of the ball groove of the master clutch's release device of a heavy load tracked vehicle was determined. Results show that the controlling wear mechanism is combined of abrasion, adhesion, contact fatigue and corrosion wear, which demonstrates the effectiveness of using combined ferrography and worn surface analysis for the study of wear mechanism of contact surface with friction.

  8. Lifelong Guidance

    National Research Council Canada - National Science Library

    Noworol, Czesław

    2011-01-01

    .... Career guidance refers to services and activities intended to assist individuals, of any age and at any point throughout their lives, to make educational, training and occupational choices and to manage their careers...

  9. 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.

  10. Analysis and design of a capsule landing system and surface vehicle control system for Mars exploration. [performance tests of remote control equipment for roving vehicles

    Science.gov (United States)

    Gisser, D. G.; Frederick, D. K.; Sandor, G. N.; Shen, C. N.; Yerazunis, S. W.

    1976-01-01

    Problems related to the design and control of an autonomous rover for the purpose of unmanned exploration of the planets were considered. Building on the basis of prior studies, a four wheeled rover of unusual mobility and maneuverability was further refined and tested under both laboratory and field conditions. A second major effort was made to develop autonomous guidance. Path selection systems capable of dealing with relatively formidable hazard and terrains involving various short range (1.0-3.0 meters), hazard detection systems using a triangulation detection concept were simulated and evaluated. The mechanical/electronic systems required to implement such a scheme were constructed and tested. These systems include: laser transmitter, photodetectors, the necessary data handling/controlling systems and a scanning mast. In addition, a telemetry system to interface the vehicle, the off-board computer and a remote control module for operator intervention were developed. Software for the autonomous control concept was written. All of the systems required for complete autonomous control were shown to be satisfactory except for that portion of the software relating to the handling of interrupt commands.

  11. Research on Roll Stabilizing Based on Energy Optimization for Autonomous Surface Vehicle

    Directory of Open Access Journals (Sweden)

    Hongjian Wang

    2014-01-01

    Full Text Available Considering the case of ASV (autonomous surface vehicle navigating with low speed near water surface, a new method for design of roll motion controller is proposed in order to restrain wave disturbance effectively and improve roll stabilizing performance. Control system design is based on GPC (general predictive control theory and working principle of zero-speed fin stabilizer. Coupling horizontal motion model of ASV is decoupled, and an equivalent transfer function of roll motion is obtained and transformed into a discrete difference equation through inverse Laplace transformation and Euler approximation. Finally, predictive model of GPC, namely, the difference equation of roll motion, is given. GPC algorithm of ASV roll motion is derived from performance index based on roll stabilizing performance and energy consumption used for driving fin stabilizer. In allusion to time-variant parameters in roll motion model, recursive least square method is adopted for parameter estimation. Simulation results of ASV roll motion control show better stabilizing performance and minimized energy consumption improved by self-adaptive GPC.

  12. Analysis of the Effects of Vitiates on Surface Heat Flux in Ground Tests of Hypersonic Vehicles

    Science.gov (United States)

    Cuda, Vincent; Gaffney, Richard L

    2008-01-01

    To achieve the high enthalpy conditions associated with hypersonic flight, many ground test facilities burn fuel in the air upstream of the test chamber. Unfortunately, the products of combustion contaminate the test gas and alter gas properties and the heat fluxes associated with aerodynamic heating. The difference in the heating rates between clean air and a vitiated test medium needs to be understood so that the thermal management system for hypersonic vehicles can be properly designed. This is particularly important for advanced hypersonic vehicle concepts powered by air-breathing propulsion systems that couple cooling requirements, fuel flow rates, and combustor performance by flowing fuel through sub-surface cooling passages to cool engine components and preheat the fuel prior to combustion. An analytical investigation was performed comparing clean air to a gas vitiated with methane/oxygen combustion products to determine if variations in gas properties contributed to changes in predicted heat flux. This investigation started with simple relationships, evolved into writing an engineering-level code, and ended with running a series of CFD cases. It was noted that it is not possible to simultaneously match all of the gas properties between clean and vitiated test gases. A study was then conducted selecting various combinations of freestream properties for a vitiated test gas that matched clean air values to determine which combination of parameters affected the computed heat transfer the least. The best combination of properties to match was the free-stream total sensible enthalpy, dynamic pressure, and either the velocity or Mach number. This combination yielded only a 2% difference in heating. Other combinations showed departures of up to 10% in the heat flux estimate.

  13. Detection of surface elevation changes using an unmanned aerial vehicle on the debris-free Storbreen glacier in Norway

    NARCIS (Netherlands)

    Kraaijenbrink, P.D.A.; Andreassen, Liss M.; Immerzeel, W.W.|info:eu-repo/dai/nl/290472113

    Recent studies have shown that the application of unmanned aerial vehicles (UAVs) has great potential to investigate the dynamic behavior of glaciers. The studies have successfully deployed UAVs over generally contrast-rich surfaces of debris-covered glaciers and highly crevassed bare ice glaciers.

  14. Detection of surface elevation changes using an unmanned aerial vehicle on the debris-free Storbreen glacier in Norway

    NARCIS (Netherlands)

    Kraaijenbrink, P.D.A.; Andreassen, Liss M.; Immerzeel, W.W.|info:eu-repo/dai/nl/290472113

    2016-01-01

    Recent studies have shown that the application of unmanned aerial vehicles (UAVs) has great potential to investigate the dynamic behavior of glaciers. The studies have successfully deployed UAVs over generally contrast-rich surfaces of debris-covered glaciers and highly crevassed bare ice glaciers.

  15. Analysis and design of a capsule landing system and surface vehicle control system for Mars exploration

    Science.gov (United States)

    Gisser, D. G.; Frederick, D. K.; Lashmet, P. K.; Sandor, G. N.; Shen, C. N.; Yerazunis, S. Y.

    1975-01-01

    Problems related to an unmanned exploration of the planet Mars by means of an autonomous roving planetary vehicle are investigated. These problems include: design, construction and evaluation of the vehicle itself and its control and operating systems. More specifically, vehicle configuration, dynamics, control, propulsion, hazard detection systems, terrain sensing and modelling, obstacle detection concepts, path selection, decision-making systems, and chemical analyses of samples are studied. Emphasis is placed on development of a vehicle capable of gathering specimens and data for an Augmented Viking Mission or to provide the basis for a Sample Return Mission.

  16. Smart limbed vehicles for naval applications. Part II. Relevant technologies and performance evaluation. Interim report on research work on smart vehicle concepts for military use on the ocean surface

    Energy Technology Data Exchange (ETDEWEB)

    Weisberg, A.; Wood, L.

    1976-09-30

    Research work in smart, unmanned water-traversing limbed vehicles for naval warfare applications is reported. The areas covered include prime movers, power transformers and actuators, structural considerations, physical control, joint servo-control, motion control, visual data and the ocean surface, smartness, and vehicle characterization. (TFD)

  17. A study on the reentry guidance for a manned lunar return vehicle%载人登月飞行器高速返回再入制导技术研究

    Institute of Scientific and Technical Information of China (English)

    胡军; 张钊

    2014-01-01

    Returning the astronauts back the Earth soundly after the lunar mission is one of the most critical phases for the future human lunar exploration project, and the skip reentry guidance is one of the key technology that must be mastered. When returned from the moon, any object is speeded up by the earth gravity, and its velocity at entry point becomes very close to the second cosmic speed. Compared with Shenzhou, which is a typical reentry vehicle from the near earth orbit, the trajectory of a lunar return vehicle is quite different. To overcome this extreme velocity challenge, the guidance navigation and control (GNC) systems have a lot work to do. When a man is in the reentry vehicle, more requirements are raised, such as limited maximum over load, adaptation to range varying and guaranteed landing point distributions. To satisfy those requests, an all-coefficient adaptive prediction-correction scheme is presented in this paper. Before entering the atmosphere, an iterative corrector is called to modify the bank angle profile, which improving the robustness of the programmed trajectory to the entry Interface condition distribution. When the vehicle penetrates into the atmosphere, an outer-loop non-iterative corrector is called to modify the trajectory which is tracked by the inner-loop short-interval guidance. For the directional control, the classical bank angle reversal method is compared with two novel bank angle reversal time point programming methods, which are coupled down-range cross-range method and the decoupled one.%返回再入段是载人登月任务完成后,保证宇航员安全返回地球的关键阶段,其跳跃式再入制导方法的研究是我国载人登月任务需要突破的一项重要关键技术。由于探月返回飞行器速度极高,其弹道特性与神舟飞船一类的近地轨道返回的飞行器有较大差别,也给制导导航与控制(简称GNC,以下同)系统设计带来较大挑战。与无人再入飞行器相比,载人

  18. Agent Based Individual Traffic Guidance

    DEFF Research Database (Denmark)

    Wanscher, Jørgen

    This thesis investigates the possibilities in applying Operations Research (OR) to autonomous vehicular traffic. The explicit difference to most other research today is that we presume that an agent is present in every vehicle - hence Agent Based Individual Traffic guidance (ABIT). The next...

  19. Effective Waterline Detection of Unmanned Surface Vehicles Based on Optical Images

    Directory of Open Access Journals (Sweden)

    Yangjie Wei

    2016-09-01

    Full Text Available Real-time and accurate detection of the sailing or water area will help realize unmanned surface vehicle (USV systems. Although there are some methods for using optical images in USV-oriented environmental modeling, both the robustness and precision of these published waterline detection methods are comparatively low for a real USV system moving in a complicated environment. This paper proposes an efficient waterline detection method based on structure extraction and texture analysis with respect to optical images and presents a practical application to a USV system for validation. First, the basic principles of local binary patterns (LBPs and gray level co-occurrence matrix (GLCM were analyzed, and their advantages were integrated to calculate the texture information of river images. Then, structure extraction was introduced to preprocess the original river images so that the textures resulting from USV motion, wind, and illumination are removed. In the practical application, the waterlines of many images captured by the USV system moving along an inland river were detected with the proposed method, and the results were compared with those of edge detection and super pixel segmentation. The experimental results showed that the proposed algorithm is effective and robust. The average error of the proposed method was 1.84 pixels, and the mean square deviation was 4.57 pixels.

  20. Effective Waterline Detection of Unmanned Surface Vehicles Based on Optical Images.

    Science.gov (United States)

    Wei, Yangjie; Zhang, Yuwei

    2016-09-27

    Real-time and accurate detection of the sailing or water area will help realize unmanned surface vehicle (USV) systems. Although there are some methods for using optical images in USV-oriented environmental modeling, both the robustness and precision of these published waterline detection methods are comparatively low for a real USV system moving in a complicated environment. This paper proposes an efficient waterline detection method based on structure extraction and texture analysis with respect to optical images and presents a practical application to a USV system for validation. First, the basic principles of local binary patterns (LBPs) and gray level co-occurrence matrix (GLCM) were analyzed, and their advantages were integrated to calculate the texture information of river images. Then, structure extraction was introduced to preprocess the original river images so that the textures resulting from USV motion, wind, and illumination are removed. In the practical application, the waterlines of many images captured by the USV system moving along an inland river were detected with the proposed method, and the results were compared with those of edge detection and super pixel segmentation. The experimental results showed that the proposed algorithm is effective and robust. The average error of the proposed method was 1.84 pixels, and the mean square deviation was 4.57 pixels.

  1. A Sea-Sky Line Detection Method for Unmanned Surface Vehicles Based on Gradient Saliency.

    Science.gov (United States)

    Wang, Bo; Su, Yumin; Wan, Lei

    2016-04-15

    Special features in real marine environments such as cloud clutter, sea glint and weather conditions always result in various kinds of interference in optical images, which make it very difficult for unmanned surface vehicles (USVs) to detect the sea-sky line (SSL) accurately. To solve this problem a saliency-based SSL detection method is proposed. Through the computation of gradient saliency the line features of SSL are enhanced effectively, while other interference factors are relatively suppressed, and line support regions are obtained by a region growing method on gradient orientation. The SSL identification is achieved according to region contrast, line segment length and orientation features, and optimal state estimation of SSL detection is implemented by introducing a cubature Kalman filter (CKF). In the end, the proposed method is tested on a benchmark dataset from the "XL" USV in a real marine environment, and the experimental results demonstrate that the proposed method is significantly superior to other state-of-the-art methods in terms of accuracy rate and real-time performance, and its accuracy and stability are effectively improved by the CKF.

  2. Use of Heated Helium to Simulate Surface Pressure Fluctuations on the Launch Abort Vehicle During Abort Motor Firing

    Science.gov (United States)

    Panda, Jayanta; James, George H.; Burnside, Nathan J.; Fong, Robert; Fogt, Vincent A.

    2011-01-01

    The solid-rocket plumes from the Abort motor of the Multi-Purpose Crew Vehicle (MPCV, also know as Orion) were simulated using hot, high pressure, Helium gas to determine the surface pressure fluctuations on the vehicle in the event of an abort. About 80 different abort situations over a wide Mach number range, (0.3abort case, typically two different Helium plume and wind tunnel conditions were used to bracket different flow matching critera. This unique, yet cost-effective test used a custom-built hot Helium delivery system, and a 6% scale model of a part of the MPCV, known as the Launch Abort Vehicle. The test confirmed the very high level of pressure fluctuations on the surface of the vehicle expected during an abort. In general, the fluctuations were found to be dominated by the very near-field hydrodynamic fluctuations present in the plume shear-layer. The plumes were found to grow in size for aborts occurring at higher flight Mach number and altitude conditions. This led to an increase in the extent of impingement on the vehicle surfaces; however, unlike some initial expectations, the general trend was a decrease in the level of pressure fluctuations with increasing impingement. In general, the highest levels of fluctuations were found when the outer edges of the plume shear layers grazed the vehicle surface. At non-zero vehicle attitudes the surface pressure distributions were found to become very asymmetric. The data from these wind-tunnel simulations were compared against data collected from the recent Pad Abort 1 flight test. In spite of various differences between the transient flight situation and the steady-state wind tunnel simulations, the hot-Helium data were found to replicate the PA1 data fairly reasonably. The data gathered from this one-of-a-kind wind-tunnel test fills a gap in the manned-space programs, and will be used to establish the acoustic environment for vibro-acoustic qualification testing of the MPCV.

  3. A control strategy for steering an autonomous surface sailing vehicle in a tacking maneuver

    DEFF Research Database (Denmark)

    Jouffroy, Jerome

    2009-01-01

    Sailing vessels such as sailboats but also landyachts are vehicles representing a real challenge for automation. However, the control aspects of such vehicles were hitherto very little studied. This paper presents a simplied dynamic model of a so-called landyacht allowing to capture the main...

  4. Evaluation Methodology for Surface Engineering Techniques to Improve Powertrain Efficiency in Military Vehicles

    Science.gov (United States)

    2012-06-01

    efficiency within military vehicle drivetrains . This report details the experimental methodology developed by the U.S. Army Research Laboratory to...experiments are conducted on a subsystem component of a vehicle drivetrain . A parallel basic research thrust includes computational modeling of...of research efforts at the basic and applied research level to advance theoretical and practical understanding of drivetrain component efficiencies

  5. Evaluation of dual multi-mission space exploration vehicle operations during simulated planetary surface exploration

    Science.gov (United States)

    Abercromby, Andrew F. J.; Gernhardt, Michael L.; Jadwick, Jennifer

    2013-10-01

    IntroductionA pair of small pressurized rovers (multi-mission space exploration vehicles, or MMSEVs) is at the center of the Global Point-of-Departure architecture for future human lunar exploration. Simultaneous operation of multiple crewed surface assets should maximize productive crew time, minimize overhead, and preserve contingency return paths. MethodsA 14-day mission simulation was conducted in the Arizona desert as part of NASA's 2010 Desert Research and Technology Studies (DRATS) field test. The simulation involved two MMSEV earth-gravity prototypes performing geological exploration under varied operational modes affecting both the extent to which the MMSEVs must maintain real-time communications with the mission control center (Continuous [CC] versus Twice-a-Day [2/D]) and their proximity to each other (Lead-and-Follow [L&F] versus Divide-and-Conquer [D&C]). As part of a minimalist lunar architecture, no communication relay satellites were assumed. Two-person crews (an astronaut and a field geologist) operated each MMSEV, day and night, throughout the entire 14-day mission, only leaving via the suit ports to perform simulated extravehicular activities. Metrics and qualitative observations enabled evaluation of the extent to which the operating modes affected productivity and scientific data quality (SDQ). Results and discussionSDQ was greater during CC mode than during 2/D mode; metrics showed a marginal increase while qualitative assessments suggested a practically significant difference. For the communications architecture evaluated, significantly more crew time (14% per day) was required to maintain communications during D&C than during L&F (5%) or 2/D (2%), increasing the time required to complete all traverse objectives. Situational awareness of the other vehicle's location, activities, and contingency return constraints were qualitatively enhanced during L&F and 2/D modes due to line-of-sight and direct MMSEV-to-MMSEV communication. Future testing

  6. Development of Response Surface Models for Rapid Analysis and Multidisciplinary Optimization of Launch Vehicle Design Concepts

    Science.gov (United States)

    Unal, Resit

    1999-01-01

    Multidisciplinary design optimization (MDO) is an important step in the design and evaluation of launch vehicles, since it has a significant impact on performance and lifecycle cost. The objective in MDO is to search the design space to determine the values of design parameters that optimize the performance characteristics subject to system constraints. Vehicle Analysis Branch (VAB) at NASA Langley Research Center has computerized analysis tools in many of the disciplines required for the design and analysis of launch vehicles. Vehicle performance characteristics can be determined by the use of these computerized analysis tools. The next step is to optimize the system performance characteristics subject to multidisciplinary constraints. However, most of the complex sizing and performance evaluation codes used for launch vehicle design are stand-alone tools, operated by disciplinary experts. They are, in general, difficult to integrate and use directly for MDO.

  7. Enabling high-quality observations of surface imperviousness for water runoff modelling from unmanned aerial vehicles

    Science.gov (United States)

    Tokarczyk, Piotr; Leitao, Joao Paulo; Rieckermann, Jörg; Schindler, Konrad; Blumensaat, Frank

    2015-04-01

    Modelling rainfall-runoff in urban areas is increasingly applied to support flood risk assessment particularly against the background of a changing climate and an increasing urbanization. These models typically rely on high-quality data for rainfall and surface characteristics of the area. While recent research in urban drainage has been focusing on providing spatially detailed rainfall data, the technological advances in remote sensing that ease the acquisition of detailed land-use information are less prominently discussed within the community. The relevance of such methods increase as in many parts of the globe, accurate land-use information is generally lacking, because detailed image data is unavailable. Modern unmanned air vehicles (UAVs) allow acquiring high-resolution images on a local level at comparably lower cost, performing on-demand repetitive measurements, and obtaining a degree of detail tailored for the purpose of the study. In this study, we investigate for the first time the possibility to derive high-resolution imperviousness maps for urban areas from UAV imagery and to use this information as input for urban drainage models. To do so, an automatic processing pipeline with a modern classification method is tested and applied in a state-of-the-art urban drainage modelling exercise. In a real-life case study in the area of Lucerne, Switzerland, we compare imperviousness maps generated from a consumer micro-UAV and standard large-format aerial images acquired by the Swiss national mapping agency (swisstopo). After assessing their correctness, we perform an end-to-end comparison, in which they are used as an input for an urban drainage model. Then, we evaluate the influence which different image data sources and their processing methods have on hydrological and hydraulic model performance. We analyze the surface runoff of the 307 individual sub-catchments regarding relevant attributes, such as peak runoff and volume. Finally, we evaluate the model

  8. 带落角约束的固定配平攻角飞行器滚转制导律设计%Design of rolling-guidance law using virtual target with control of terminal azimuth for a fixed-trim vehicle

    Institute of Scientific and Technical Information of China (English)

    耿克达; 周军; 林鹏

    2015-01-01

    Fixed⁃trim vehicle with attack angle has the characteristic of simple configuration and less control channels. Howev⁃er,as the magnitude of lift force is uncontrollable,an appropriate guidance law is needed to ensure the guidance accuracy.Thus,in order to solve the guidance problem with the control of terminal azimuth for fixed⁃trim vehicle,a rolling⁃guidance law with virtual tar⁃get was proposed. The rolling⁃guidance equation with virtual target was established. The basic guidance method was put forward, which is proved that the guidance law could accurately steer the vehicle and control the terminal azimuth effectively. The design method of virtual target was also given and the validity of rolling guidance was analyzed by simulation. The simulation result illus⁃trates that:the rolling⁃guidance law with virtual target in this paper not only has higher precision of guidance and terminal azimuth control,but also has the simple design,which is convenient for engineering application.%固定配平攻角飞行器具有外形简单、控制通道少的优点,但其升力大小不可控,为实现精确制导,解决其带终端角度约束制导的问题,提出了一种含虚拟目标的滚转制导律设计方法。建立了含虚拟目标的滚转制导方程,给出了基本导引关系,并证明了该导引关系下设计的制导律能有效对飞行器落点与落角进行控制。同时,给出了虚拟目标详细设计方法,并通过数值仿真验证了该制导律的有效性。仿真结果表明,提出的含虚拟目标的滚转制导律设计方法具有较高的制导精度与落角精度,同时设计方法简单,便于工程应用。

  9. Aggregate strength for bituminous surfacings for low volume roads: a heavy vehicle simulator experience

    CSIR Research Space (South Africa)

    Paige-Green, P

    2004-09-01

    Full Text Available This paper discusses an investigation using the CSIR Transportek Heavy Vehicle Simulator (HVS) to determine the impact of using aggregates softer than specified in chip seals and to propose possible relaxations in the currently specified strength...

  10. STUDY AND REALISATION OF COMPOSITE GUIDANCE MECHANISM IN POWERED FLIGHT PHASE OF LAUNCH VEHICLE%运载火箭主动段综合引导机制研究与实现

    Institute of Scientific and Technical Information of China (English)

    何春晗; 夏明飞; 周张华

    2014-01-01

    火箭主动段飞行过程中,由于测控设备失效,导致测量数据丢失,设备恢复后无法快速重捕目标。利用某点测量数据的速度值,参考理论弹道上最相近速度值,引入科氏力概念,通过对变质量质点的运动力学分析,实现数据修正及弹道的外推。以MFC为软件应用平台,研究实现一种新型运载火箭飞行引导机制软件。试验表明,该新型运载火箭飞行引导机制,能够高精度、全弧段实现火箭飞行主动段的有效引导。并且基于MFC平台的软件系统具有很强的灵活性和可操作性。%In rocket’s powered flight process,since the failure of monitoring and control equipment,it causes the measured data miss and unable to fast re-capture the target after the equipment being recovered.To solve the problem,by using the speed value of measured data at certain point,referring to the most appropriate speed value in theoretical trajectory,and introducing Coriolis force concept,we realise the data revision and trajectory extrapolation through kinematics analysis on variable mass particles.Furthermore,we study and implement a novel flight guidance mechanism software for launch vehicle by taking MFC as the software application platform.Tests show that the new guidance mechanism can realise effective guidance in powered flight phase of the rocket with high precision and whole arc,the MFC platform-based software system has very good flexibility and operability.

  11. Eco-efficiency optimization of Hybrid Electric Vehicle based on response surface method and genetic algorithm

    OpenAIRE

    Nzisabira, Jonathan; Louvigny, Yannick; Duysinx, Pierre

    2008-01-01

    The electric vehicles (EV) and sometimes the hybrid electric vehicle (HEV) technologies are environmentally very efficient but can not succeed on the market because of a smaller ability to satisfy customer’s requirements. Comparison of clean technologies in automotive and transportation systems has been measured using different analysis tools such as LCA (life cycle analysis). However, these instruments never account for the user’s satisfaction which partly explains the market acceptance prob...

  12. Integration of an Acoustic Modem onto a Wave Glider Unmanned Surface Vehicle

    Science.gov (United States)

    2012-06-01

    equation for the power of each wave. (4.9) 2 2 2 [W] 32wave g H T Vρ π Π = The vehicle is of course not able to use all of this power for thrust as...modem and the node. The glider portion of the vehicle tends to lead the float portion by 0.55 meters [6]. Using simple trigonometry we can

  13. Surface engineering of macrophages with nanoparticles to generate a cell–nanoparticle hybrid vehicle for hypoxia-targeted drug delivery

    Directory of Open Access Journals (Sweden)

    Christopher A Holden

    2009-12-01

    Full Text Available Christopher A Holden1, Quan Yuan1, W Andrew Yeudall2,3, Deborah A Lebman3,4, Hu Yang11Department of Biomedical Engineering, School of Engineering, 2Philips Institute of Oral and Craniofacial Molecular Biology, School of Dentistry, 3Massey Cancer Center, 4Department of Microbiology and Immunology, School of Medicine, Virginia Commonwealth University, Richmond, VA, USAAbstract: Tumors frequently contain hypoxic regions that result from a shortage of oxygen due to poorly organized tumor vasculature. Cancer cells in these areas are resistant to radiation- and chemotherapy, limiting the treatment efficacy. Macrophages have inherent hypoxia-targeting ability and hold great advantages for targeted delivery of anticancer therapeutics to cancer cells in hypoxic areas. However, most anticancer drugs cannot be directly loaded into macrophages because of their toxicity. In this work, we designed a novel drug delivery vehicle by hybridizing macrophages with nanoparticles through cell surface modification. Nanoparticles immobilized on the cell surface provide numerous new sites for anticancer drug loading, hence potentially minimizing the toxic effect of anticancer drugs on the viability and hypoxia-targeting ability of the macrophage vehicles. In particular, quantum dots and 5-(aminoacetamido fluoresceinlabeled polyamidoamine dendrimer G4.5, both of which were coated with amine-derivatized polyethylene glycol, were immobilized to the sodium periodate-treated surface of RAW264.7 macrophages through a transient Schiff base linkage. Further, a reducing agent, sodium cyanoborohydride, was applied to reduce Schiff bases to stable secondary amine linkages. The distribution of nanoparticles on the cell surface was confirmed by fluorescence imaging, and it was found to be dependent on the stability of the linkages coupling nanoparticles to the cell surface.Keywords: anticancer drug, cellular vehicle, confocal microscopy, dendrimer, drug delivery, hypoxia

  14. Design and Testing of a Prototype Lunar or Planetary Surface Landing Research Vehicle (LPSLRV)

    Science.gov (United States)

    Murphy, Gloria A.

    2010-01-01

    This handbook describes a two-semester senior design course sponsored by the NASA Office of Education, the Exploration Systems Mission Directorate (ESMD), and the NASA Space Grant Consortium. The course was developed and implemented by the Mechanical and Aerospace Engineering Department (MAE) at Utah State University. The course final outcome is a packaged senior design course that can be readily incorporated into the instructional curriculum at universities across the country. The course materials adhere to the standards of the Accreditation Board for Engineering and Technology (ABET), and is constructed to be relevant to key research areas identified by ESMD. The design project challenged students to apply systems engineering concepts to define research and training requirements for a terrestrial-based lunar landing simulator. This project developed a flying prototype for a Lunar or Planetary Surface Landing Research Vehicle (LPSRV). Per NASA specifications the concept accounts for reduced lunar gravity, and allows the terminal stage of lunar descent to be flown either by remote pilot or autonomously. This free-flying platform was designed to be sufficiently-flexible to allow both sensor evaluation and pilot training. This handbook outlines the course materials, describes the systems engineering processes developed to facilitate design fabrication, integration, and testing. This handbook presents sufficient details of the final design configuration to allow an independent group to reproduce the design. The design evolution and details regarding the verification testing used to characterize the system are presented in a separate project final design report. Details of the experimental apparatus used for system characterization may be found in Appendix F, G, and I of that report. A brief summary of the ground testing and systems verification is also included in Appendix A of this report. Details of the flight tests will be documented in a separate flight test

  15. Launch flexibility using NLP guidance and remote wind sensing

    Science.gov (United States)

    Cramer, Evin J.; Bradt, Jerre E.; Hardtla, John W.

    1990-01-01

    This paper examines the use of lidar wind measurements in the implementation of a guidance strategy for a nonlinear programming (NLP) launch guidance algorithm. The NLP algorithm uses B-spline command function representation for flexibility in the design of the guidance steering commands. Using this algorithm, the guidance system solves a two-point boundary value problem at each guidance update. The specification of different boundary value problems at each guidance update provides flexibility that can be used in the design of the guidance strategy. The algorithm can use lidar wind measurements for on pad guidance retargeting and for load limiting guidance steering commands. Examples presented in the paper use simulated wind updates to correct wind induced final orbit errors and to adjust the guidance steering commands to limit the product of the dynamic pressure and angle-of-attack for launch vehicle load alleviation.

  16. Impact of different vehicles for laser-assisted drug permeation via skin: full-surface versus fractional ablation.

    Science.gov (United States)

    Lee, Woan-Ruoh; Shen, Shing-Chuan; Aljuffali, Ibrahim A; Li, Yi-Ching; Fang, Jia-You

    2014-02-01

    This study aimed to assess impact of different vehicles for laser-assisted skin drug delivery. We also tried to uncover the mechanisms by which different vehicles affect laser-aided skin permeation. Full-surface ablative (conventional) and fractional lasers were used to irradiate nude mouse skin. Imiquimod and 5-aminolevulinic acid (ALA) were used as lipophilic and hydrophilic permeants. Vehicles employed included water with 40% polyethylene glycol 400 (PEG 400), propylene glycol (PG), and ethanol. Lipid nanoparticles were also utilized as carriers. In vitro permeation profiles showed improvement in imiquimod flux with conventional laser (2.5 J/cm2) producing a 12-, 9-, and 5-fold increase when loading imiquimod in 40% PEG400, PG, and ethanol, respectively, as compared with intact skin. Nanoparticulate delivery by laser produced a 6-fold enhancement in permeation. Fractional laser produced less enhancement of imiquimod delivery than conventional laser. Laser exposure increased follicular imiquimod accumulation from 0.80 to 5.81 μg/cm2. ALA permeation from aqueous buffer, PEG 400, and PG with conventional laser treatment was 641-, 445-, and 104-fold superior to passive control. In vivo skin deposition of topically applied ALA examined by confocal microscopy indicated the same trend as the in vitro experiment, with aqueous buffer showing the greatest proporphyllin IX signaling. Diffusion of cosolvent molecules into ablated skin and drug partitioning from vehicle to skin are two predominant factors controlling laser-assisted delivery. In contrast to conventional laser, lateral drug diffusion was anticipated for fractional laser. Our results suggest that different drug delivery vehicles substantially influence drug penetration enhanced by lasers.

  17. Seasonal surface velocities of a Himalayan glacier derived by automated correlation of unmanned aerial vehicle imagery

    NARCIS (Netherlands)

    Kraaijenbrink, Philip; Meijer, Sander W.; Shea, Joseph M.; Pellicciotti, Francesca; De Jong, Steven M.; Immerzeel, Walter W.

    2016-01-01

    Debris-covered glaciers play an important role in the high-altitude water cycle in the Himalaya, yet their dynamics are poorly understood, partly because of the difficult fieldwork conditions. In this study we therefore deploy an unmanned aerial vehicle (UAV) three times (May 2013, October 2013 and

  18. Smart Sensor Based Obstacle Detection for High-Speed Unmanned Surface Vehicle

    DEFF Research Database (Denmark)

    Hermann, Dan; Galeazzi, Roberto; Andersen, Jens Christian

    2015-01-01

    . A computer vision horizon detector enables a highly accurate attitude estimation despite large and sudden vehicle accelerations. This further facilitates the reduction of sea clutter by utilising a attitude based statistical measure. Full scale sea trials show a significant increase in obstacle tracking...

  19. Seasonal surface velocities of a Himalayan glacier derived by automated correlation of unmanned aerial vehicle imagery

    NARCIS (Netherlands)

    Kraaijenbrink, Philip; Meijer, Sander W.; Shea, Joseph M.; Pellicciotti, Francesca; De Jong, Steven M.|info:eu-repo/dai/nl/120221306; Immerzeel, Walter W.|info:eu-repo/dai/nl/290472113

    2016-01-01

    Debris-covered glaciers play an important role in the high-altitude water cycle in the Himalaya, yet their dynamics are poorly understood, partly because of the difficult fieldwork conditions. In this study we therefore deploy an unmanned aerial vehicle (UAV) three times (May 2013, October 2013 and

  20. Vibration Analysis of 5-DOF Vehicle Model under Stochastic Road Surface Excitation

    Directory of Open Access Journals (Sweden)

    Zhang Yanlong

    2016-01-01

    Full Text Available Considering human body vertical motion, vehicle body vertical motion, pitch movement and vertical jump of front and rear wheels, a five-degree-of-freedom vehicle model is established to study basic driving characteristics of the vehicle. Using Fourier transform method, acceleration power spectral density of the seat and the mean square value curves of seat vertical weighted acceleration are obtained by numerical simulation. Combined with comfort provision standards, the influence of vehicle model parameters and speed on seat acceleration power spectral density and vertical root-mean-square value of seat weighted acceleration are analyzed. Results show that the stiffness and damping of the seat have no significant effect on seat acceleration power spectral density, and seat acceleration PSD increases with increasing front or rear suspension stiffness, but it decreases with increasing front or rear suspension damping. It should also be concluded that the model stiffness and the mean square value of seat vertical weighted acceleration present positive correlation in general, but seat vertical weighted acceleration decrease first and then increase when model damping increase. Such analysis results can provide reference for the parameter optimization design of the automobile.

  1. Interstitial guidance of cancer invasion.

    Science.gov (United States)

    Gritsenko, Pavlo G; Ilina, Olga; Friedl, Peter

    2012-01-01

    Cancer cell invasion into healthy tissues develops preferentially along pre-existing tracks of least resistance, followed by secondary tissue remodelling and destruction. The tissue scaffolds supporting or preventing guidance of invasion vary in structure and molecular composition between organs. In the brain, the guidance is provided by myelinated axons, astrocyte processes, and blood vessels which are used as invasion routes by glioma cells. In the human breast, containing interstitial collagen-rich connective tissue, disseminating breast cancer cells preferentially invade along bundled collagen fibrils and the surface of adipocytes. In both invasion types, physical guidance prompted by interfaces and space is complemented by molecular guidance. Generic mechanisms shared by most, if not all, tissues include (i) guidance by integrins towards fibrillar interstitial collagen and/or laminins and type IV collagen in basement membranes decorating vessels and adipocytes, and, likely, CD44 engaging with hyaluronan; (ii) haptotactic guidance by chemokines and growth factors; and likely (iii) physical pushing mechanisms. Tissue-specific, resticted guidance cues include ECM proteins with restricted expression (tenascins, lecticans), cell-cell interfaces, and newly secreted matrix molecules decorating ECM fibres (laminin-332, thrombospondin-1, osteopontin, periostin). We here review physical and molecular guidance mechanisms in interstitial tissue and brain parenchyma and explore shared principles and organ-specific differences, and their implications for experimental model design and therapeutic targeting of tumour cell invasion.

  2. Homing guidance and docking control algorithm for autonomous underwater vehicles%自主水下航行器的回坞导引和入坞控制算法

    Institute of Scientific and Technical Information of China (English)

    高剑; 严卫生; 徐德民; 刘明雍

    2012-01-01

    To fulfill the requirements on the underwater autonomous recovery ability of Autonomous Underwater Vehicles (AUVs) in the fields of the military reconnaissance and the oceanic environment inspection, the guidance and control problem of the homing and docking operations during the process of underwater recovery by docking station are studied. The autonomous recovery action is divided into two sequential stages, namely the homing stage and docking stage, and the different control strategies are applied. In the homing stage, the conventional Line-of-Sight(LOS) guidance algorithm is used to drive the AUV to reach the homing waypoint in front of the docking station. In the following docking stage, the nonlinear cross-tracking control method is adopted to control the AUV tracking the docking path along the center line of the docking station and finally entering the station. This autonomous recovery method is proved effective and suitable for practical applications by the simulation studies with the REMUS AUV model.%针对军事侦察和海洋环境监测领域中对自主水下航行器(AUV)水下自主回收能力的需求,研究了AUV自主回收过程中回坞和入坞的导引和控制问题.将水下自主回收过程分为回坞导引和入坞控制两个连续的阶段,其中回坞阶段采用经典的视线(LOS)导引法,使AUV到达回收器正前方的回坞航路点;入坞阶段则采用非线性横向跟踪控制方法,使AUV精确跟踪沿回收器中轴线的入坞直线航路航行并最终进入回收器.采用REMUS AUV的模型参数对水下回收进行了仿真研究,结果表明该方法是有效的,具有良好的工程应用前景.

  3. FY2015 Vehicle Systems Annual Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2016-01-31

    The Vehicle Systems research and development (R&D) subprogram within the DOE Vehicle Technologies Office (VTO) provides support and guidance for many cutting-edge automotive technologies under development. Research focuses on addressing critical barriers to advancing light-, medium-, and heavy-duty vehicle systems to help maximize the number of electric miles driven and increase the energy efficiency of transportation vehicles.

  4. Autonomous gliding entry guidance with

    Directory of Open Access Journals (Sweden)

    Guo Jie

    2015-10-01

    Full Text Available This paper presents a novel three-dimensional autonomous entry guidance for relatively high lift-to-drag ratio vehicles satisfying geographic constraints and other path constraints. The guidance is composed of onboard trajectory planning and robust trajectory tracking. For trajectory planning, a longitudinal sub-planner is introduced to generate a feasible drag-versus-energy profile by using the interpolation between upper boundary and lower boundary of entry corridor to get the desired trajectory length. The associated magnitude of the bank angle can be specified by drag profile, while the sign of bank angle is determined by lateral sub-planner. Two-reverse mode is utilized to satisfy waypoint constraints and dynamic heading error corridor is utilized to satisfy no-fly zone constraints. The longitudinal and lateral sub-planners are iteratively employed until all of the path constraints are satisfied. For trajectory tracking, a novel tracking law based on the active disturbance rejection control is introduced. Finally, adaptability tests and Monte Carlo simulations of the entry guidance approach are performed. Results show that the proposed entry guidance approach can adapt to different entry missions and is able to make the vehicle reach the prescribed target point precisely in spite of geographic constraints.

  5. Method for warning of radiological and chemical substances using detection paints on a vehicle surface

    Science.gov (United States)

    Farmer, Joseph C [Tracy, CA

    2012-03-13

    A system for warning of corrosion, chemical, or radiological substances. The system comprises painting a surface with a paint or coating that includes an indicator material and monitoring the surface for indications of the corrosion, chemical, or radiological substances.

  6. Finite-time sliding mode attitude control for a reentry vehicle with blended aerodynamic surfaces and a reaction control system

    Directory of Open Access Journals (Sweden)

    Geng Jie

    2014-08-01

    Full Text Available This paper proposes a finite-time robust flight controller, targeting for a reentry vehicle with blended aerodynamic surfaces and a reaction control system (RCS. Firstly, a novel finite-time attitude controller is pointed out with the introduction of a nonsingular finite-time sliding mode manifold. The attitude tracking errors are mathematically proved to converge to zero within finite time which can be estimated. In order to improve the performance, a second-order finite-time sliding mode controller is further developed to effectively alleviate chattering without any deterioration of robustness and accuracy. Moreover, an optimization control allocation algorithm, using linear programming and a pulse-width pulse-frequency (PWPF modulator, is designed to allocate torque commands for all the aerodynamic surface deflections and on–off switching-states of RCS thrusters. Simulations are provided for the reentry vehicle considering uncertain parameters and external disturbances for practical purposes, and the results demonstrate the effectiveness and robustness of the attitude control system.

  7. Finite-time sliding mode attitude control for a reentry vehicle with blended aerodynamic surfaces and a reaction control system

    Institute of Scientific and Technical Information of China (English)

    Geng Jie; Sheng Yongzhi; Liu Xiangdong

    2014-01-01

    This paper proposes a finite-time robust flight controller, targeting for a reentry vehicle with blended aerodynamic surfaces and a reaction control system (RCS). Firstly, a novel finite-time attitude controller is pointed out with the introduction of a nonsingular finite-time sliding mode manifold. The attitude tracking errors are mathematically proved to converge to zero within finite time which can be estimated. In order to improve the performance, a second-order finite-time slid-ing mode controller is further developed to effectively alleviate chattering without any deterioration of robustness and accuracy. Moreover, an optimization control allocation algorithm, using linear programming and a pulse-width pulse-frequency (PWPF) modulator, is designed to allocate torque commands for all the aerodynamic surface deflections and on-off switching-states of RCS thrusters. Simulations are provided for the reentry vehicle considering uncertain parameters and external disturbances for practical purposes, and the results demonstrate the effectiveness and robustness of the attitude control system.

  8. Effects of thermochemistry, nonequilibrium, and surface catalysis on the design of hypersonic vehicles

    Science.gov (United States)

    Scott, Carl D.

    1989-01-01

    An account is given of the function of physical aspects of a gas on the characteristics of the flow and of the heating associated with hypersonic flight. At the high temperatures encountered, the thermal and chemical characteristics of the air in a hypersonic vehicle's shock layer are altered in ways which depend on the atomic and molecular structure of N and O and their ions; similar effects exist in scramjet propulsion systems. These properties in turn influence the character of shock waves and expansions, and hence the pressure, temperature, and velocity distributions. Transport properties affecting the boundary-layer structure will also affect heat flux and shear stress.

  9. 面向冲突避免的航空器场面滑行引导方法%Conflict Avoidance Oriented Airport Surface Aircraft Taxiing Guidance Method

    Institute of Scientific and Technical Information of China (English)

    汤新民; 安宏锋; 王翀

    2011-01-01

    为避免大型高密度机场航空器之间可能发生的冲突,提出了一种基于混杂系统结构的滑行引导方案.建立了航空器滑行连续动力学模型和航空器在滑行道直线段、交叉口运行的离散事件动态系统模型,通过场面运行观测器建立了连续状态到离散状态的映射.采用禁止状态线性不等式约束和禁止状态逻辑互斥约束,描述场面运行模型应遵循的控制规范,并给出满足控制规范的离散控制器设计方法.最后建立了运行模型中可控变迁的使能状态到场面冲突控制策略的映射.通过助航灯光沙盘控制系统的验证表明,该滑行引导方法能及时对可能冲突的航空器采取恰当的控制策略,并实时生成航空器滑行操纵指令,能有效避免航空器滑行冲突.%To avoid confliction troubles between aircrafts at high density airports, an aircraft taxiing guidance framework based on hybrid system is proposed. Firstly, an aircraft taxiing dynamic model in continuous space and discrete event dynamic system models for the taxiing operation on straightaway and intersection are built, and a surface operation observer that maps the continuous dynamic state into discrete observation is proposed. Secondly, the forbidden state avoidance-based regulations described by linear inequality constraints and logical mutex constraints are introduced to express surface traffic control rules, and the discrete controller design method are proposed. Finally, the mapping from the enabling state of controllable transition in the straightaway and intersection operation models to control strategies is built. The validation by control system of an airfield lighting sand table shows that the taxiing guidance method can issue feasible control strategies in time and generate taxi manoeuvring instructions for aircrafts to avoid potential taxiing conflicts effectively.

  10. Surface Mapping using Quadcopter

    OpenAIRE

    Haugen, Kenneth Eide

    2014-01-01

    This thesis studies the use of unmanned aerial vehicles to perform ice managementin the Arctic Ocean by gathering information about and physically control the iceenvironment. Such a system is needed for safety reasons as marine operations aremoving further north. In order to gather information about the ice environment, aUAV will be used for surface mapping. The quadcopter Parrot AR. Drone 2.0 will be used as a testbed for implementing proposed strategies for guidance, navigation and control ...

  11. Deploying Electric Vehicles and Electric Vehicle Supply Equipment: Tiger Teams Offer Project Assistance for Federal Fleets

    Energy Technology Data Exchange (ETDEWEB)

    None

    2017-01-02

    To assist federal agencies with the transition to plug-in electric vehicles (PEVs), including battery electric vehicles (BEVs) and plug-in hybrid electric vehicles (PHEVs), FEMP offers technical guidance on electric vehicle supply equipment (EVSE) installations and site-specific planning through partnerships with the National Renewable Energy Laboratory’s EVSE Tiger Teams.

  12. Approach to solution of coupled heat transfer problem on the surface of hypersonic vehicle of arbitrary shape

    Science.gov (United States)

    Bocharov, A. N.; Bityurin, V. A.; Golovin, N. N.; Evstigneev, N. M.; Petrovskiy, V. P.; Ryabkov, O. I.; Teplyakov, I. O.; Shustov, A. A.; Solomonov, Yu S.; Fortov, V. E.

    2016-11-01

    In this paper, an approach to solve conjugate heat- and mass-transfer problems is considered to be applied to hypersonic vehicle surface of arbitrary shape. The approach under developing should satisfy the following demands. (i) The surface of the body of interest may have arbitrary geometrical shape. (ii) The shape of the body can change during calculation. (iii) The flight characteristics may vary in a wide range, specifically flight altitude, free-stream Mach number, angle-of-attack, etc. (iv) The approach should be realized with using the high-performance-computing (HPC) technologies. The approach is based on coupled solution of 3D unsteady hypersonic flow equations and 3D unsteady heat conductance problem for the thick wall. Iterative process is applied to account for ablation of wall material and, consequently, mass injection from the surface and changes in the surface shape. While iterations, unstructured computational grids both in the flow region and within the wall interior are adapted to the current geometry and flow conditions. The flow computations are done on HPC platform and are most time-consuming part of the whole problem, while heat conductance problem can be solved on many kinds of computers.

  13. Dynamic modeling of wave driven unmanned surface vehicle in longitudinal profile based on D-H approach

    Institute of Scientific and Technical Information of China (English)

    田宝强; 俞建成; 张艾群

    2015-01-01

    Wave driven unmanned surface vehicle (WUSV) is a new concept ocean robot drived by wave energy and solar energy, and it is very suitable for the vast ocean observations with incomparable endurance. Its dynamic modeling is very important because it is the theoretical foundation for further study in the WUSV motion control and efficiency analysis. In this work, the multibody system of WUSV was described based on D-H approach. Then, the driving principle was analyzed and the dynamic model of WUSV in longitudinal profile is established by Lagrangian mechanics. Finally, the motion simulation of WUSV and comparative analysis are completed by setting different inputs of sea state. Simulation results show that the WUSV dynamic model can correctly reflect the WUSV longitudinal motion process, and the results are consistent with the wave theory.

  14. Serret-Frenet frame based on path following control for underactuated unmanned surface vehicles with dynamic uncertainties

    Institute of Scientific and Technical Information of China (English)

    廖煜雷; 张铭钧; 万磊

    2015-01-01

    The path following problem for an underactuated unmanned surface vehicle (USV) in the Serret−Frenet frame is addressed. The control system takes account of the uncertain influence induced by model perturbation, external disturbance, etc. By introducing the Serret−Frenet frame and global coordinate transformation, the control problem of underactuated system (a nonlinear system with single-input and ternate-output) is transformed into the control problem of actuated system (a single-input and single-output nonlinear system), which simplifies the controller design. A backstepping adaptive sliding mode controller (BADSMC) is proposed based on backstepping design technique, adaptive method and theory of dynamic slide model control (DSMC). Then, it is proven that the state of closed loop system is globally stabilized to the desired configuration with the proposed controller. Simulation results are presented to illustrate the effectiveness of the proposed controller.

  15. Analysis of Spatial-Temporal Sampling and Equal Distance Parallel Formation Control of Unmanned Surface Bathymetric Vehicle

    Directory of Open Access Journals (Sweden)

    Jiucai Jin

    2013-07-01

    Full Text Available Analysis of the spatial-temporal sampling of Unmanned Surface Bathymetric Vehicles (USBV is vital for depth measurement performance, which is the basis for optimum sampling of multi-USBV cooperative parallel formations. This paper’s ultimate goal is to find the optimum sampling style of multi- USBV parallel formations and to design the corresponding control law. First, the relationship between spatial-temporal sampling intervals and measurement performance is examined using the Objective Analysis method, giving an illustrative example of the sampling of two USBVs. Second, three types of spatial-temporal constraint are defined and the type of USBV is analysed, which is spatially constrained. Lastly, according to the spatially constrained USBV type, the control law for multi- USBV equal-distance parallel formations with spatial synchrony is designed based on self-propelled particles theory, which is validated in the simulations based on the USBV dynamic model.

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

    Science.gov (United States)

    Xu, Bin; Yang, Chenguang; Pan, Yongping

    2015-10-01

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

  17. Land surface reflectance retrieval from hyperspectral data collected by an unmanned aerial vehicle over the Baotou test site.

    Science.gov (United States)

    Duan, Si-Bo; Li, Zhao-Liang; Tang, Bo-Hui; Wu, Hua; Ma, Lingling; Zhao, Enyu; Li, Chuanrong

    2013-01-01

    To evaluate the in-flight performance of a new hyperspectral sensor onboard an unmanned aerial vehicle (UAV-HYPER), a comprehensive field campaign was conducted over the Baotou test site in China on 3 September 2011. Several portable reference reflectance targets were deployed across the test site. The radiometric performance of the UAV-HYPER sensor was assessed in terms of signal-to-noise ratio (SNR) and the calibration accuracy. The SNR of the different bands of the UAV-HYPER sensor was estimated to be between approximately 5 and 120 over the homogeneous targets, and the linear response of the apparent reflectance ranged from approximately 0.05 to 0.45. The uniform and non-uniform Lambertian land surface reflectance was retrieved and validated using in situ measurements, with root mean square error (RMSE) of approximately 0.01-0.07 and relative RMSE of approximately 5%-12%. There were small discrepancies between the retrieved uniform and non-uniform Lambertian land surface reflectance over the homogeneous targets and under low aerosol optical depth (AOD) conditions (AOD = 0.18). However, these discrepancies must be taken into account when adjacent pixels had large land surface reflectance contrast and under high AOD conditions (e.g. AOD = 1.0).

  18. Land surface reflectance retrieval from hyperspectral data collected by an unmanned aerial vehicle over the Baotou test site.

    Directory of Open Access Journals (Sweden)

    Si-Bo Duan

    Full Text Available To evaluate the in-flight performance of a new hyperspectral sensor onboard an unmanned aerial vehicle (UAV-HYPER, a comprehensive field campaign was conducted over the Baotou test site in China on 3 September 2011. Several portable reference reflectance targets were deployed across the test site. The radiometric performance of the UAV-HYPER sensor was assessed in terms of signal-to-noise ratio (SNR and the calibration accuracy. The SNR of the different bands of the UAV-HYPER sensor was estimated to be between approximately 5 and 120 over the homogeneous targets, and the linear response of the apparent reflectance ranged from approximately 0.05 to 0.45. The uniform and non-uniform Lambertian land surface reflectance was retrieved and validated using in situ measurements, with root mean square error (RMSE of approximately 0.01-0.07 and relative RMSE of approximately 5%-12%. There were small discrepancies between the retrieved uniform and non-uniform Lambertian land surface reflectance over the homogeneous targets and under low aerosol optical depth (AOD conditions (AOD = 0.18. However, these discrepancies must be taken into account when adjacent pixels had large land surface reflectance contrast and under high AOD conditions (e.g. AOD = 1.0.

  19. The Wave Glider°: A New Autonomous Surface Vehicle to Augment MBARI's Growing Fleet of Ocean Observing Systems

    Science.gov (United States)

    Tougher, B. B.

    2011-12-01

    Monterey Bay Aquarium Research Institute's (MBARI) evolving fleet of ocean observing systems has made it possible to collect information and data about a wide variety of ocean parameters, enabling researchers to better understand marine ecosystems. In collaboration with Liquid Robotics Inc, the designer of the Wave Glider autonomous surface vehicle (ASV), MBARI is adding a new capability to its suite of ocean observing tools. This new technology will augment MBARI research programs that use satellites, ships, moorings, drifters, autonomous underwater vehicles (AUVs) and remotely operated vehicles (ROVs) to improve data collection of temporally and spatially variable oceanographic features. The Wave Glider ASV derives its propulsion from wave energy, while sensors and communications are powered through the use of two solar panels and batteries, enabling it to remain at sea indefinitely. Wave Gliders are remotely controlled via real-time Iridium burst communications, which also permit real-time data telemetry. MBARI has developed Ocean Acidification (OA) moorings to continuously monitor the chemical and physical changes occurring in the ocean as a result of increased levels of atmospheric carbon dioxide (CO2). The moorings are spatially restricted by being anchored to the seafloor, so during the summer of 2011 the ocean acidification sensor suite designed for moorings was integrated into a Wave Glider ASV to increase both temporal and spatial ocean observation capabilities. The OA sensor package enables the measurement of parameters essential to better understanding the changing acidity of the ocean, specifically pCO2, pH, oxygen, salinity and temperature. The Wave Glider will also be equipped with a meteorological sensor suite that will measure air temperature, air pressure, and wind speed and direction. The OA sensor integration into a Wave Glider was part of MBARI's 2011 summer internship program. This project involved designing a new layout for the OA sensors

  20. Probing Earth’s conductivity structure beneath oceans by scalar geomagnetic data: autonomous surface vehicle solution

    DEFF Research Database (Denmark)

    Kuvshinov, Alexey; Matzka, Jürgen; Poedjono, Benny

    2016-01-01

    this method, known as magnetotellurics, to oceanic regions is challenging since only vector instruments placed at the sea bottom can provide such data. Here, we discuss a concept of marine induction surveying which is based on sea-surface scalar magnetic field measurements from a modern position...... to the conductivity structure beneath the ocean. We conclude that the sensitivity, depending on the bathymetry gradient, is typically largest near the coast offshore. We show that such sea-surface marine induction surveys can be performed with the Wave Glider, an easy-to-deploy, autonomous, energy-harvesting floating...

  1. Guidance and dispersion studies of National Launch System ascent trajectories

    Science.gov (United States)

    Hanson, John M.; Shrader, M. W.; Chang, Hopen; Freeman, Scott E.

    1992-01-01

    The National Launch System (NLS) is a joint concept, between DoD and NASA, for building a family of new launch vehicles. Two of the many choices to be made are the trajectory shaping methods and the onboard guidance scheme. This paper presents results from some ongoing studies to address these issues. First, potential gains from new guidance concepts are listed. Next the paper gives a list of possible discriminators between different guidance schemes, lists a number of potential guidance schemes, and explains two in some detail. A reference scheme is tested to determine its performance versus the discriminators. Finally, results from some special studies using the reference guidance scheme are given, including the effects of closed-loop guidance initiation time, time of enforcement of sideslip, vehicle roll for engine out, time and location of an engine out, use of load relief control, and use of day of launch wind biasing.

  2. Integral evaluation of a road surface and the interaction between road and vehicle

    NARCIS (Netherlands)

    Bennis, T.A.; Wit, L.B. de; Hoogvelt, R.B.J.; Jansen, S.T.H.

    1996-01-01

    The influence of several road characteristics like longitudinal and transverse evenness and skid resistance are always evaluated separately on the aspects comfort and/or safety. This passes over the influence these surface characteristics can have in combination on riding comfort and safety. This pa

  3. Teleautonomous guidance for mobile robots

    Science.gov (United States)

    Borenstein, J.; Koren, Y.

    1990-01-01

    Teleautonomous guidance (TG), a technique for the remote guidance of fast mobile robots, has been developed and implemented. With TG, the mobile robot follows the general direction prescribed by an operator. However, if the robot encounters an obstacle, it autonomously avoids collision with that obstacle while trying to match the prescribed direction as closely as possible. This type of shared control is completely transparent and transfers control between teleoperation and autonomous obstacle avoidance gradually. TG allows the operator to steer vehicles and robots at high speeds and in cluttered environments, even without visual contact. TG is based on the virtual force field (VFF) method, which was developed earlier for autonomous obstacle avoidance. The VFF method is especially suited to the accommodation of inaccurate sensor data (such as that produced by ultrasonic sensors) and sensor fusion, and allows the mobile robot to travel quickly without stopping for obstacles.

  4. Evolved Acceleration Guidance for Planetary Entry

    Science.gov (United States)

    Mease, K. D.; Leavitt, J. A.; Ferch, M.

    The U.S. Apollo and Shuttle programs have proven the viability and effectiveness of acceleration guidance. New capabilities have been developed to augment this basic concept. Algorithms have been designed for low lift to drag ratio vehicles and for mid to high lift to drag ratio vehicles. These algorithms have been tested for Mars landing and for earth entry of reusable launch vehicles and have performed well in both cases. Also the trajectory planner has been incorporated into a landing footprint generator that is designed for on-board use.

  5. Advances in spacecraft atmospheric entry guidance

    Science.gov (United States)

    Benito Manrique, Joel

    In order to advance entry guidance technology two different research areas have been explored with the objective of increasing the reachable landing area and the landing accuracy for future Mars missions. Currently only the northern hemisphere of Mars is available for landing due to its low elevation. Only low elevation landing sites have the necessary atmospheric density to allow landing using current Entry, Descent and Landing (EDL) technology. In order to reach most of the Ancient Highlands, the majority of the southern hemisphere, advanced EDL technology is needed in multiple fields, including entry guidance. The first research area is the definition and applications of reachable and controllable sets for entry. The definition of the reachable and controllable sets provides a framework for the study of the capabilities of an entry vehicle in a given planet. Reachable and controllable sets can be used to comprehensively characterize the envelope of trajectories that a vehicle can fly, the sites it can reach and the entry states that can be accommodated. The sets can also be used for the evaluation of trajectory planning algorithms and to assist in the selection of the entry or landing sites. In essence, the reachable and controllable sets offer a powerful vehicle and trajectory analysis and design framework that allows for better mission design choices. In order to illustrate the use of the sets, they are computed for a representative Mars mission using two different vehicle configurations. The sets characterize the impact of the vehicle configuration on the entry capability. Furthermore, the sets are used to find the best skip-entry trajectory for a return from the Moon mission, highlighting the utility of the sets in atmospheric maneuvers other than entry. The second research area is the development of the components of an entry guidance algorithm that allow high elevation landing and provide as well high landing accuracy. The approach taken follows the

  6. Road-rail vehicle

    NARCIS (Netherlands)

    Evers, J.J.M.

    2002-01-01

    A transport vehicle equipped with a number of first wheel sets, having wheels provided with tires, to which steering means and driving means, if any, are coupled to enable the transport vehicle to be moved over a road surface. The transport vehicle further comprises at least one second wheel set, ha

  7. Analysing Interplanetary Probe Guidance Accuracy

    Directory of Open Access Journals (Sweden)

    S. V. Sukhova

    2016-01-01

    Full Text Available The paper presents a guidance accuracy analysis and estimates delta-v budget required to provide the trajectory correction maneuvers for direct interplanetary flights (without midcourse gravity assists. The analysis takes into consideration the orbital hyperbolic injection errors (depend on a selected launch vehicle and ascent trajectory and the uncertainties of midcourse correction maneuvers.The calculation algorithm is based on Monte Carlo simulation and Danby’s matrix methods (the matrizant of keplerian motion. Danby’s method establishes a link between the errors of the spacecraft state vectors at different flight times using the reference keplerian orbit matrizant. Utilizing the nominal trajectory parameters and the covariance matrix of launch vehicle injection errors the random perturbed orbits are generated and required velocity corrections are calculated. The next step is to simulate midcourse maneuver performance uncertainty using the midcourse maneuver covariance matrix. The obtained trajectory correction impulses and spacecraft position errors are statistically processed to compute required delta-v budget and dispersions ellipse parameters for different prediction intervals.As an example, a guidance accuracy analysis has been conducted for a 2022 mission to Mars and a Venus mission in 2026. The paper considers one and two midcourse correction options, as well as utilization of two different launch vehicles.The presented algorithm based on Monte Carlo simulation and Danby’s methods provides preliminary evaluation for midcourse corrections delta-v budget and spacecraft position error. The only data required for this guidance accuracy analysis are a reference keplerian trajectory and a covariance matrix of the injection errors. Danby’s matrix method allows us to take into account also the other factors affecting the trajectory thereby increasing the accuracy of analysis.

  8. A new surface-inset, permanent-magnet, brushless dc motor drive for electric vehicles

    OpenAIRE

    Chau, KT; J. Gan; Chan, CC; Jiang, JZ

    2000-01-01

    A new five-phase, surface-inset, permanent-magnet (PM), brushless dc motor drive is proposed in this paper. The motor drive has advantages of both the PM brushless dc motor drive and the dc series motor drive. The originlity is that the air-gap flux of the motor is generated by both the PM excitation and the specially controlled stator currents (two particular phases) under the same PM pole. The motor configuration and principle of operation are so unusual that the magnetic field distribution...

  9. Probing Earth's conductivity structure beneath oceans by scalar geomagnetic data: autonomous surface vehicle solution

    Science.gov (United States)

    Kuvshinov, Alexey; Matzka, Jürgen; Poedjono, Benny; Samrock, Friedemann; Olsen, Nils; Pai, Sudhir

    2016-11-01

    The electric conductivity distribution of the Earth's crust and upper mantle provides a key to unraveling its structure. Information can be obtained from vector data time series of the natural variations of the magnetic and electric field in a directional stable reference frame. Applying this method, known as magnetotellurics, to oceanic regions is challenging since only vector instruments placed at the sea bottom can provide such data. Here, we discuss a concept of marine induction surveying which is based on sea-surface scalar magnetic field measurements from a modern position-keeping platform. The concept exploits scalar magnetic responses that relate variations of the scalar magnetic field at the survey sites with variations of the horizontal magnetic field at a reference site. A 3-D model study offshore Oahu Island (Hawaii) demonstrates that these responses are sensitive to the conductivity structure beneath the ocean. We conclude that the sensitivity, depending on the bathymetry gradient, is typically largest near the coast offshore. We show that such sea-surface marine induction surveys can be performed with the Wave Glider, an easy-to-deploy, autonomous, energy-harvesting floating platform with position-keeping capability.[Figure not available: see fulltext.

  10. Application of a Winch-type Towed Acoustic Sensor to a Wave-powered Unmanned Surface Vehicle

    Directory of Open Access Journals (Sweden)

    Taejun Moh

    2016-12-01

    Full Text Available Although many countries have focused on anti-submarine warfare for several decades, underwater submarines can hardly be detected by current assets such as patrol aircraft, surface ships and fixed underwater surveillance systems. Due to the difficult conditions of the oceanic environment and the relative quietness of submarines, existing acoustic surveillance platforms are not able to fully cover their mission areas. To fill in the gaps, a winch-type towed acoustic sensor system was developed and integrated into a wave-powered unmanned surface vehicle by the Korea Institute of Ocean Science and Technology. In June 2015, sea trial tests were conducted to verify maneuvering, acoustic signal detection, and communication capabilities. During the maneuvering test, the wave-powered glider successfully moved along programmed waypoints. Despite towing the acoustic sensor system, only 20% of initial electricity was consumed in 20 days. The acoustic sensor was lowered to depths of 100–150 m by the winch system, and received signals from an acoustic simulator lowered to depths of 50–100 m by RV Jangmok. Simulated submarine noises that were refracted downward could be clearly received and classified by the hydrophone system, from distances of 2–8 km, while it was being towed silently and deeply. In addition, an optical camera provided high-resolution images of surface vessels, allowing integration with acoustic detection of underwater objects. In conclusion, this new platform using a deeply towed hydrophone system is worthy of consideration as an underwater surveillance asset. Future work is required to strengthen inter-asset communication and obstacle avoidance, and to overcome strong currents to make this technology a reliable part of the underwater surveillance network.

  11. Space shuttle guidance, navigation, and control design equations. Volume 3: Guidance

    Science.gov (United States)

    1973-01-01

    Space shuttle guidance, navigation, and control design equations are presented. The space-shuttle mission includes three relatively distinct guidance phases which are discussed; atmospheric boost, which is characterized by an adaptive guidance law; extra-atmospheric activities; and re-entry activities, where aerodynamic surfaces are the principal effectors. Guidance tasks include pre-maneuver targeting and powered flight guidance, where powered flight is defined to include the application of aerodynamic forces as well as thruster forces. A flow chart which follows guidance activities throughout the mission from the pre-launch phase through touchdown is presented. The main guidance programs and subroutines used in each phase of a typical rendezvous mission are listed. Detailed software requirements are also presented.

  12. Shuttle entry guidance revisited using nonlinear geometric methods

    Science.gov (United States)

    Mease, Kenneth D.; Kremer, Jean-Paul

    1994-11-01

    The entry guidance law for the space shuttle orbiter is revisited using nonlinear geometric methods. The shuttle guidance concept is to track a reference drag trajectory that has been designed to lead a specified range and velocity. It is shown that the approach taken in the original derivation of the shuttle entry guidance has much in common with the more recently developed feedback linearization method of differential geometric control. Using the feedback linearization method, however, an alternative, potentially superior, guidance law was formulated. Comparing the two guidance laws based performance domains in state space, taking into account the nonlinear dynamics, the alternative guidance law achieves the desired performance over larger domains in state space; the stability domain of the laws are similar. With larger operating domain for the shuttle or some other entry vehicle, the alternative guidance law should be considered.

  13. On guidance and volatility

    NARCIS (Netherlands)

    Billings, M.B.; Jennings, R.; Lev, B.

    2013-01-01

    Survey evidence suggests that managers voluntarily disclose information, particularly earnings guidance, with an aim toward dampening share price volatility. Yet, consultants and influential institutions advise against providing guidance — citing fears of litigation and market penalties associated w

  14. Graphic Turbulence Guidance

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Forecast turbulence hazards identified by the Graphical Turbulence Guidance algorithm. The Graphical Turbulence Guidance product depicts mid-level and upper-level...

  15. Graphical Turbulence Guidance - Composite

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Forecast turbulence hazards identified by the Graphical Turbulence Guidance algorithm. The Graphical Turbulence Guidance product depicts mid-level and upper-level...

  16. 水面无人艇发展与应用%Development and Application of Unmanned Surface Vehicle

    Institute of Scientific and Technical Information of China (English)

    李家良

    2012-01-01

    Unmanned Surface Vehicle (USV) is a motion platform, which can navigate autonomously in the marine environment and complete various tasks. The current development of USV is introduced. The basic technology characteristics of USV are presented in the thesis. The applications of USV include anti-submarine warfare, mine countermeasures, ISR, unconventional combat domains and etc. Key technologies in USV development are analyzed. Along with the requirements of unmanned combat systems in future war, USV become one important component part of unmanned systems at sea. The USV are developing towards the directions of intelligence, systematism and standardization.%水面无人艇是一种能够在海洋环境下自主航行,并完成各种任务的小型水面运动平台.介绍了当前无人艇的发展现状,对无人艇的基本技术特点进行了总结,对其在反潜战、反水雷战、信息战、非常规作战等领域的应用以及需要解决的关键技术进行了分析.随着未来战争对发晨无人作战平台的需求,无人艇成为海上无人系统的重要组成部分,并向着智能化、体系化、标准化的方向发展.

  17. Hydrodynamic Efficiency Improvement of the High Skew Propeller for the Underwater Vehicle Under Surface and Submerged Conditions

    Institute of Scientific and Technical Information of China (English)

    Hassan Ghassemi; Parviz Ghadimi

    2011-01-01

    An algorithm based on the Boundary Element Method (BEM) is presented for designing the High Skew Propeller (HSP)used in an Underwater Vehicle (UV).Since UVs operate under two different kinds of working conditions (i.e.surface and submerged conditions),the design of such a propeller is an unwieldy task.This is mainly due to the fact that the resistance forces as well as the vessel efficiency under these conditions are significantly different.Therefore,some factors are necessary for the design of the optimum propeller to utilize the power under the mentioned conditions.The design objectives of the optimum propeller are to obtain the highest possible thrust and efficiency with the minimum torque.For the current UV,the main dimensions of the propeller are predicted based on the given required thrust and the defined operating conditions.These dimensions (number of blades,pitch,diameter,expanded area ratio,thickness and camber) are determined through iterative procedure.Because the propeller operates at the stem of the UV where the inflow velocity to the propeller is non-uniform,a 5-blade HSP is preferred for running the UV.Finally,the propeller is designed based on the numerical calculations to acquire the improved hydrodynamic efficiency.

  18. Detection of surface elevation changes using an unmanned aerial vehicle on the debris-free Storbreen glacier in Norway

    Science.gov (United States)

    Kraaijenbrink, Philip; Andreassen, Liss; Immerzeel, Walter

    2016-04-01

    Recent studies have shown that the application of unmanned aerial vehicles (UAVs) has great potential to investigate the dynamic behavior of glaciers. The studies have successfully deployed UAVs over generally contrast-rich surfaces of debris-covered glaciers and highly crevassed bare ice glaciers. In this study, the potential of UAVs in glaciology is further exploited, as we use a fixed-wing UAV over the largely snow-covered Storbreen glacier in Norway in September 2015. The acquired UAV-imagery was processed into accurate digital elevation models and image mosaics using a Structure from Motion workflow. Georeferencing of the data was obtained by ingesting ground control points into the workflow that were accurately measured with a differential global navigation satellite system (DGNSS). Geodetic accuracy was determined by comparison with DGNSS surface profiles and stake positions that were measured on the same day. The processed data were compared with a LIDAR survey and airborne imagery acquisition from September and October 2009 to examine mass loss patterns and glacier retreat. Results show that the UAV is capable of producing high-quality elevation models and image mosaics for the low-contrast snow-covered Storbreen at unprecedented detail. The accuracy of the output product is lower when compared to contrast-rich debris-covered glaciers, but still considerably more accurate than spaceborne data products. Comparison with LIDAR data shows a spatially heterogeneous downwasting pattern of about 0.75 m a-1 over 2009-2015 for the upper part of Storbreen. The lower part exhibits considerably more downwasting in the range of 0.9-2.1 m a-1. We conclude that UAVs can be valuable for surveys of snow-covered glaciers to provide sufficient accurate elevation models and image mosaics, and we recommend the use of UAVs for the routine monitoring of benchmark glaciers such as Storbreen.

  19. Application of a Fully Numerical Guidance to Mars Aerocapture

    Science.gov (United States)

    Matz, Daniel A.; Lu, Ping; Mendeck, Gavin F.; Sostaric, Ronald R.

    2017-01-01

    An advanced guidance algorithm, Fully Numerical Predictor-corrector Aerocapture Guidance (FNPAG), has been developed to perform aerocapture maneuvers in an optimal manner. It is a model-based, numerical guidance that benefits from requiring few adjustments across a variety of different hypersonic vehicle lift-to-drag ratios, ballistic co-efficients, and atmospheric entry conditions. In this paper, FNPAG is first applied to the Mars Rigid Vehicle (MRV) mid lift-to-drag ratio concept. Then the study is generalized to a design map of potential Mars aerocapture missions and vehicles, ranging from the scale and requirements of recent robotic to potential human and precursor missions. The design map results show the versatility of FNPAG and provide insight for the design of Mars aerocapture vehicles and atmospheric entry conditions to achieve desired performance.

  20. Influence of AC external magnetic field on guidance force relaxation between HTS bulk and NdFeB guideway

    Science.gov (United States)

    Zhang, Longcai; Wang, Suyu; Wang, Jiasu; Zheng, Jun

    2007-12-01

    Superconducting maglev vehicle is one of the most promising applications of HTS bulks. In such a system, the HTS bulks are always exposed to time-varying external magnetic field, which is generated by the inhomogeneous surface magnetic field of the NdFeB guideway. So it is required to study whether the guidance force of the bulks is influenced by the inhomogeneity. In this paper, we studied the characteristics of the guidance force relaxation between the HTS bulk and the NdFeB guideway by an experiment in which AC external magnetic field generated by an electromagnet was used to simulate the time-varying external magnetic field caused by the inhomogeneity of the guideway. From the experiment results, it was found that the guidance force was decreased with the application of the AC external magnetic field, and the decay increased with the amplitude and was almost independent of the frequency.

  1. Entry Vehicle Control System Design for the Mars Smart Lander

    Science.gov (United States)

    Calhoun, Philip C.; Queen, Eric M.

    2002-01-01

    The NASA Langley Research Center, in cooperation with the Jet Propulsion Laboratory, participated in a preliminary design study of the Entry, Descent and Landing phase for the Mars Smart Lander Project. This concept utilizes advances in Guidance, Navigation and Control technology to significantly reduce uncertainty in the vehicle landed location on the Mars surface. A candidate entry vehicle controller based on the Reaction Control System controller for the Apollo Lunar Excursion Module digital autopilot is proposed for use in the entry vehicle attitude control. A slight modification to the phase plane controller is used to reduce jet-firing chattering while maintaining good control response for the Martian entry probe application. The controller performance is demonstrated in a six-degree-of-freedom simulation with representative aerodynamics.

  2. Hydrogen-bonding layer-by-layer-assembled biodegradable polymeric micelles as drug delivery vehicles from surfaces.

    Science.gov (United States)

    Kim, Byeong-Su; Park, Sang Wook; Hammond, Paula T

    2008-02-01

    We present the integration of amphiphilic block copolymer micelles as nanometer-sized vehicles for hydrophobic drugs within layer-by-layer (LbL) films using alternating hydrogen bond interactions as the driving force for assembly for the first time, thus enabling the incorporation of drugs and pH-sensitive release. The film was constructed based on the hydrogen bonding between poly(acrylic acid) (PAA) as an H-bond donor and biodegradable poly(ethylene oxide)-block-poly(epsilon-caprolactone) (PEO-b-PCL) micelles as the H-bond acceptor when assembled under acidic conditions. By taking advantage of the weak interactions of the hydrogen-bonded film on hydrophobic surfaces, it is possible to generate flexible free-standing films of these materials. A free-standing micelle LbL film of (PEO-b-PCL/PAA)60 with a thickness of 3.1 microm was isolated, allowing further characterization of the bulk film properties, including morphology and phase transitions, using transmission electron microscopy and differential scanning calorimetry. Because of the sensitive nature of the hydrogen bonding employed to build the multilayers, the film can be rapidly deconstructed to release micelles upon exposure to physiological conditions. However, we could also successfully control the rate of film deconstruction by cross-linking carboxylic acid groups in PAA through thermally induced anhydride linkages, which retard the drug release to the surrounding medium to enable sustained release over multiple days. To demonstrate efficacy in delivering active therapeutics, in vitro Kirby-Bauer assays against Staphylococcus aureus were used to illustrate that the drug-loaded micelle LbL film can release significant amounts of an active antibacterial drug, triclosan, to inhibit the growth of bacteria. Because the micellar encapsulation of hydrophobic therapeutics does not require specific chemical interactions, we believe this noncovalent approach provides a new route to integrating active small

  3. Long-Life, Oil-Free, Light-Weight, Multi-Roller Traction Drives for Planetary Vehicle Surface Exploration Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A multi-roller "oil free" traction drive is under development for use on vehicles used in hostile environments like those that will be encountered on planetary...

  4. Wave-Powered Unmanned Surface Vehicle as a Station-Keeping Gateway Node for Undersea Distributed Networks

    Science.gov (United States)

    2012-09-01

    vehicles, Papa Mau, suffered a loss of Iridium satellite link for a significant amount of time and another, Piccard Maru, was attacked by a shark...latitude, time of year, cloud cover, fog, and angle of the sun’s rays. Wave Gliders are controlled and navigated using an Iridium satellite link, GPS...10]. The four Wave Gliders follow a course that is issued to the vehicles via the WGMS and the Iridium satellite link. GPS fixes are used to track

  5. Unmanned Surface Vehicle Automatic Navigation Based On GPS%基于 GPS 定位的无人艇自主导航

    Institute of Scientific and Technical Information of China (English)

    陈永泽; 舒军勇; 王真亮; 谢能刚

    2016-01-01

    This paper mainly investigated unmanned surface vehicle automatic navigation based on GPS.According to the GPS received position coordinates and planning target point coordinates,this paper put forward an automatic navigation algorithm.Experimental sample of unmanned surface vehicle was established and actual trajectory was gained.By the actual trajectory and the comparison of theoretical trajectory as a result,we proved that the unmanned surface vehicle navigation algorithm has good robustness.%研究了基于 GPS 定位技术的无人艇自主导航。根据 GPS 接收到的位置坐标和规划的目标点坐标,提出一种自主导航算法。研制了无人艇实验样船,得到了无人艇实际航行轨迹。实际航行轨迹和理论航行轨迹的对比结果表明:该无人艇自主导航算法具有良好的鲁棒性。

  6. Autonomous gliding entry guidance with geographic constraints

    Institute of Scientific and Technical Information of China (English)

    Guo Jie; Wu Xuzhong; Tang Shengjing

    2015-01-01

    This paper presents a novel three-dimensional autonomous entry guidance for relatively high lift-to-drag ratio vehicles satisfying geographic constraints and other path constraints. The guidance is composed of onboard trajectory planning and robust trajectory tracking. For trajectory planning, a longitudinal sub-planner is introduced to generate a feasible drag-versus-energy profile by using the interpolation between upper boundary and lower boundary of entry corridor to get the desired trajectory length. The associated magnitude of the bank angle can be specified by drag profile, while the sign of bank angle is determined by lateral sub-planner. Two-reverse mode is utilized to satisfy waypoint constraints and dynamic heading error corridor is utilized to satisfy no-fly zone constraints. The longitudinal and lateral sub-planners are iteratively employed until all of the path constraints are satisfied. For trajectory tracking, a novel tracking law based on the active disturbance rejection control is introduced. Finally, adaptability tests and Monte Carlo simulations of the entry guidance approach are performed. Results show that the proposed entry guidance approach can adapt to different entry missions and is able to make the vehicle reach the prescribed target point precisely in spite of geographic constraints.

  7. Career guidance in communities

    DEFF Research Database (Denmark)

    Thomsen, Rie

    The aim of this paper is to inspire practitioners and professionals to leave their offices to bring career guidance into communities that might not identify with career guidance in the first instance. By making the effort to engage with communities, practitioners may bring about a critical change...

  8. Corporate information management guidance

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-08-01

    At the request of the Department of Energy`s (DOE) Information Management (IM) Council, IM representatives from nearly all Headquarters (HQ) organizations have been meeting over the past year as the Corporate Guidance Group (CGG) to develop useful and sound corporate information management (IM) guidance. The ability of the Department`s IM community to develop such unified guidance continues to be critical to the success of future Departmental IM planning processes and the establishment of a well-coordinated IM environment between Headquarters and field organizations. This report, with 26 specific corporate IM guidance items documented and unanimously agreed to, as well as 12 items recommended for further development and 3 items deferred for future consideration, represents a highly successful effort by the IM community. The effort has proven that the diverse DOE organizations can put aside individual preferences and work together towards a common and mutually beneficial goal. In examining most areas and issues associated with information management in the Department, they have developed specific, far-reaching, and useful guidance. The IM representatives recommend that the documented guidance items provided in this report and approved by the DOE IM Council be followed by all IM organizations. The representatives also strongly recommend that the guidance process developed by the CGG be the single process for developing corporate IM guidance.

  9. Respiratory motion compensated overlay of surface models from cardiac MR on interventional x-ray fluoroscopy for guidance of cardiac resynchronization therapy procedures

    Science.gov (United States)

    Manzke, R.; Bornstedt, A.; Lutz, A.; Schenderlein, M.; Hombach, V.; Binner, L.; Rasche, V.

    2010-02-01

    Various multi-center trials have shown that cardiac resynchronization therapy (CRT) is an effective procedure for patients with end-stage drug invariable heart failure (HF). Despite the encouraging results of CRT, at least 30% of patients do not respond to the treatment. Detailed knowledge of the cardiac anatomy (coronary venous tree, left ventricle), functional parameters (i.e. ventricular synchronicity) is supposed to improve CRT patient selection and interventional lead placement for reduction of the number of non-responders. As a pre-interventional imaging modality, cardiac magnetic resonance (CMR) imaging has the potential to provide all relevant information. With functional information from CMR optimal implantation target sites may be better identified. Pre-operative CMR could also help to determine whether useful vein target segments are available for lead placement. Fused with X-ray, the mainstay interventional modality, improved interventional guidance for lead-placement could further help to increase procedure outcome. In this contribution, we present novel and practicable methods for a) pre-operative functional and anatomical imaging of relevant cardiac structures to CRT using CMR, b) 2D-3D registration of CMR anatomy and functional meshes with X-ray vein angiograms and c) real-time capable breathing motion compensation for improved fluoroscopy mesh overlay during the intervention based on right ventricular pacer lead tracking. With these methods, enhanced interventional guidance for left ventricular lead placement is provided.

  10. Shuttle entry guidance

    Science.gov (United States)

    Harpold, J. C.; Graves, C. A., Jr.

    1978-01-01

    This paper describes the design of the entry guidance for the Space Shuttle Orbiter. This guidance provides the steering commands for trajectory control from initial penetration of the earth's atmosphere until the terminal area guidance is activated at an earth-relative speed of 2500 fps. At this point, the Orbiter is at a distance of about 50 nmi from the runway threshold, and at an altitude of about 80,000 ft. The entry guidance design is based on an analytic solution of the equations of motion defining the drag acceleration profile that meets the terminal criteria of the entry flight while maintaining the flight within systems and operational constraints. Guidance commands, which are based on a control law that ensures damping of oscillatory type trajectory motion, are computed to steer the Orbiter to this drag acceleration profile.

  11. Shuttle entry guidance revisited

    Science.gov (United States)

    Mease, Kenneth D.; Kremer, Jean-Paul

    1992-08-01

    The Shuttle entry guidance concept is reviewed which is aimed at tracking a reference drag trajectory that leads to the specified range and velocity for the initiation of the terminal energy management phase. An approximate method of constructing the domain of attraction is proposed, and its validity is ascertained by simulation. An alternative guidance law yielding global exponential tracking in the absence of control saturation is derived using a feedback linearization method. It is noted that the alternative guidance law does not improve on the stability and performance of the current guidance law, for the operating domain and control capability of the Shuttle. It is suggested that the new guidance law with a larger operating domain and increased lift-to-drag capability would be superior.

  12. Shuttle entry guidance revisited

    Science.gov (United States)

    Mease, Kenneth D.; Kremer, Jean-Paul

    1992-01-01

    The Shuttle entry guidance concept is reviewed which is aimed at tracking a reference drag trajectory that leads to the specified range and velocity for the initiation of the terminal energy management phase. An approximate method of constructing the domain of attraction is proposed, and its validity is ascertained by simulation. An alternative guidance law yielding global exponential tracking in the absence of control saturation is derived using a feedback linearization method. It is noted that the alternative guidance law does not improve on the stability and performance of the current guidance law, for the operating domain and control capability of the Shuttle. It is suggested that the new guidance law with a larger operating domain and increased lift-to-drag capability would be superior.

  13. Intelligent Vehicle Health Management

    Science.gov (United States)

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

    2005-01-01

    objectives: Guidance and Navigation; Communications and Tracking; Vehicle Monitoring; Information Transport and Integration; Vehicle Diagnostics; Vehicle Prognostics; Vehicle mission Planning; Automated Repair and Replacement; Vehicle Control; Human Computer Interface; and Onboard Verification and Validation. Furthermore, the presented framework provides complete vehicle management which not only allows for increased crew safety and mission success through new intelligence capabilities, but also yields a mechanism for more efficient vehicle operations. The representative IVHM technologies for computer platform using heterogeneous communication, 3) coupled electromagnetic oscillators for enhanced communications, 4) Linux-based real-time systems, 5) genetic algorithms, 6) Bayesian Networks, 7) evolutionary algorithms, 8) dynamic systems control modeling, and 9) advanced sensing capabilities. This paper presents IVHM technologies developed under NASA's NFFP pilot project and the integration of these technologies forms the framework for IIVM.

  14. Re-Entry Guidance Using an Energy-State Equation

    Science.gov (United States)

    Abe, Akio; Shimada, Yuzo; Uchiyama, Kenji

    This paper presents a new guidance and control system for a re-entry vehicle. In the conventional drag acceleration control system employed for the present space shuttles, the velocity is an unobservable state variable and the associated pole tends to be unstable. Therefore, in this study, a condition which allows all the states to be observable is introduced using a state-space linearization method. It is also shown that energy and its rate are appropriate for the state variables. A guidance law is analytically derived on the basis of the obtained state equation with respect to the energy by solving a two-point boundary-value problem. Furthermore, a tracking control system is designed to make the position, velocity, and flight path angle of the vehicle track the reference states generated in the guidance system. Finally, numerical simulation is performed to verify the validity of the obtained plant expression, and the effectiveness of the proposed guidance and control system.

  15. Vehicle to Vehicle Services

    DEFF Research Database (Denmark)

    Brønsted, Jeppe Rørbæk

    2008-01-01

    , mobility, and availability of services. The dissertation consists of two parts. Part I gives an overview of service oriented architecture for pervasive computing systems and describes the contributions of the publications listed in part II. We investigate architecture for vehicular technology applications......As computing devices, sensors, and actuators pervade our surroundings, new applications emerge with accompanying research challenges. In the transportation domain vehicles are being linked by wireless communication and equipped with an array of sensors and actuators that make is possible to provide...... location aware infotainment, increase safety, and lessen environmental strain. This dissertation is about service oriented architecture for pervasive computing with an emphasis on vehicle to vehicle applications. If devices are exposed as services, applications can be created by composing a set of services...

  16. Dynamics of aerospace vehicles

    Science.gov (United States)

    Schmidt, David K.

    1991-01-01

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

  17. An extended car-following model with consideration of speed guidance at intersections

    Science.gov (United States)

    Zhao, Jing; Li, Peng

    2016-11-01

    The main motivation of this paper is to analyze the influences of speed guidance strategies on the driving behaviors under four different traffic signalized conditions and to investigate an extended car-following model to explore how the speed guidance affects two different vehicle types that are intelligent vehicles and traditional vehicles during the phase-change periods. The numerical results show that the proposed model can qualitatively describe the impacts of the speed guidance strategies on vehicle's movement trail including the acceleration strategy, smooth braking strategy, and deceleration strategy. Moreover, the benefits of the speed guidance could be enhanced by lengthening the guiding space range, expanding permitted guiding speed range, and increasing the percentage of the intelligent vehicles.

  18. A Formal Investigation of the Organization of Guidance Behavior: Implications for Humans and Autonomous Guidance

    Science.gov (United States)

    Kong, Zhaodan

    Guidance behavior generated either by artificial agents or humans has been actively studied in the fields of both robotics and cognitive science. The goals of these two fields are different. The former is the automatic generation of appropriate or even optimal behavior, while the latter is the understanding of the underlying mechanism. Their challenges, though, are closely related, the most important one being the lack of a unified, formal and grounded framework where the guidance behavior can be modeled and studied. This dissertation presents such a framework. In this framework, guidance behavior is analyzed as the closed-loop dynamics of the whole agent-environment system. The resulting dynamics give rise to interaction patterns. The central points of this dissertation are that: first of all, these patterns, which can be explained in terms of symmetries that are inherent to the guidance behavior, provide building blocks for the organization of behavior; second, the existence of these patterns and humans' organization of their guidance behavior based on these patterns are the reasons that humans can generate successful behavior in spite of all the complexities involved in the planning and control. This dissertation first gives an overview of the challenges existing in both scientific endeavors, such as human and animal spatial behavior study, and engineering endeavors, such as autonomous guidance system design. It then lays out the foundation for our formal framework, which states that guidance behavior should be interpreted as the collection of the closed-loop dynamics resulting from the agent's interaction with the environment. The following, illustrated by examples of three different UAVs, shows that the study of the closed-loop dynamics should not be done without the consideration of vehicle dynamics, as is the common practice in some of the studies in both autonomous guidance and human behavior analysis. The framework, the core concepts of which are

  19. Drag-based composite super-twisting sliding mode control law design for Mars entry guidance

    Science.gov (United States)

    Zhao, Zhenhua; Yang, Jun; Li, Shihua; Guo, Lei

    2016-06-01

    In this paper, the drag-based trajectory tracking guidance problem is investigated for Mars entry vehicle subject to uncertainties. A composite super twisting sliding mode control method based on finite-time disturbance observer is proposed for guidance law design. The proposed controller not only eliminates the effects of matched and mismatched disturbances due to uncertainties of atmospheric models and vehicle aerodynamics but also guarantees the continuity of control action. Numerical simulations are carried out on the basis of Mars Science Laboratory mission, where the results show that the proposed methods can improve the Mars entry guidance precision as compared with some existing guidance methods including PID and ADRC.

  20. Descent guidance and mission planning for space shuttle

    Science.gov (United States)

    Joosten, B. K.

    1985-01-01

    The Space Shuttle descent mission planning, mission design, deorbit targeting, and entry guidance have necessarily become interrelated because of the nature of the Orbiter's design and mission requirements. The desired descent trajectory has been formulated in a drag acceleration/relative velocity state space since nearly all of the vehicle's highly constraining flight limitations can be uniquely represented in this plane. Constraints and flight requirements that affect the descent are described. The guidance logic which allows the Orbiter to follow the designed trajectory, the impacts of contingency aborts and flightcrew interaction are discussed. The mission planning and guidance techniques remain essentially unchanged through the Shuttle flight test program and subsequent operational flights.

  1. Extended High-Gain Observer for Mars Entry Guidance

    Directory of Open Access Journals (Sweden)

    Pingyuan Cui

    2013-02-01

    Full Text Available To deliver a Mars entry vehicle to the prescribed parachute deployment point, active entry guidance is essential. This paper addresses the problem of Mars atmospheric entry guidance through drag tracking method with extended high gain observer. First, an extended high gain observer combined with feedback linearization is applied in drag tracking for Mars entry longitudinal guidance.  The observer estimates the drag and drag rate for drag tracking, estimates the perturbation due to model uncertainty and disturbance, and compensate for the perturbation by canceling its estimate. Then, bank reversal is adopted in the lateral plane to reduce the cross-range error. Finally, Mars entry simulation is performed to assess the performance of the adaptive guidance law. The results demonstrate that the proposed guidance law exhibits good performance.

  2. Laser Guidance Analysis Facility

    Data.gov (United States)

    Federal Laboratory Consortium — This facility, which provides for real time, closed loop evaluation of semi-active laser guidance hardware, has and continues to be instrumental in the development...

  3. Analysis of operational manning requirements and deployment procedures for unmanned surface vehicles aboard U.S. Navy ships

    OpenAIRE

    2006-01-01

    This research was conducted in association with Naval Warfare Development Command (NWDC) requests to update Unmanned Vehicle Tactical Memorandum TM-3-22- 5-SW. The research identified and discussed significant USV manning considerations such as source ratings and manpower qualities to pilot, operate sensors, support USV electronics, and the manpower implications associated with various weapons systems alternatives. In addition, this research described several existing and notional USV ta...

  4. Image structural analysis in the tasks of automatic navigation of unmanned vehicles and inspection of Earth surface

    Science.gov (United States)

    Lutsiv, Vadim; Malyshev, Igor

    2013-10-01

    The automatic analysis of images of terrain is urgent for several decades. On the one hand, such analysis is a base of automatic navigation of unmanned vehicles. On the other hand, the amount of information transferred to the Earth by modern video-sensors increases, thus a preliminary classification of such data by onboard computer becomes urgent. We developed an object-independent approach to structural analysis of images. While creating the methods of image structural description, we did our best to abstract away from the partial peculiarities of scenes. Only the most general limitations were taken into account, that were derived from the laws of organization of observable environment and from the properties of image formation systems. The practical application of this theoretic approach enables reliable matching the aerospace photographs acquired from differing aspect angles, in different day-time and seasons by sensors of differing types. The aerospace photographs can be matched even with the geographic maps. The developed approach enabled solving the tasks of automatic navigation of unmanned vehicles. The signs of changes and catastrophes can be detected by means of matching and comparison of aerospace photographs acquired at different time. We present the theoretical proofs of chosen strategy of structural description and matching of images. Several examples of matching of acquired images with template pictures and maps of terrain are shown within the frameworks of navigation of unmanned vehicles or detection of signs of disasters.

  5. Guidance proposal for using available DegT50 values for estimation of degradation rates of plant protection products in Dutch surface water and sediment

    NARCIS (Netherlands)

    Boesten, J.J.T.I.; Adriaanse, P.I.; Horst, ter M.M.S.; Tiktak, A.; Linden, van der A.M.A.

    2014-01-01

    The degradation rate of plant protection products and their transformation products in surface water and sediment may influence their concentrations in Dutch surface water. Therefore the estimation of these rates may be an important part of the assessment of the exposure of aquatic organisms. We

  6. My view on occupation guidance

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Occupation instruction needs to the support of theories,in the case of the occupation guidance theory is not very developed in our country,It has very important sense that absorbing and drawing lessons from the advanced occupation guidance theory,and targeting guidance to occupation guidance work,.

  7. Nonlinear Path-following Control of an Autonomous Surface Vehicle%自主船非线性路径跟踪控制

    Institute of Scientific and Technical Information of China (English)

    施淑伟; 严卫生; 高剑; 王迪

    2011-01-01

    A nonlinear path following control method is proposed for the nonlinear and underactuated Autonomous Surface Vehicle. The Serret-Frenet coordinate originating at the free reference point on the path is used to describe the path following errors and their dynamic model. Meanwhile, a non-time variable is selected as reference variable, which makes the system get rid of the time factor. Then, based on Lyapunov theory and back stepping techniques, a nonlinear controller is designed, which yields asymptotic convergence of the path following errors to zero. Finally, simulation results verify the effectiveness of the proposed path following controller.%针对非线性欠驱动自主船(Autonomous Surface Vehicle,ASV),提出了一种非线性路径跟踪控制方法.采用以自由参考点为原点的Serret-Frenet坐标系摧述路径跟踪误差及其动态模型,并选用非时间量为参考变量,摆脱了时间因素的影响;综合应用Lyapunov理论与Back stepping方法设计了欠驱动自主船的路径跟踪控制律,保证了路径跟踪误差的全局渐近稳定.最后,仿真研究结果验证了该方法的有效性.

  8. Near-Optimal Operation of Dual-Fuel Launch Vehicles

    Science.gov (United States)

    Ardema, M. D.; Chou, H. C.; Bowles, J. V.

    1996-01-01

    A near-optimal guidance law for the ascent trajectory from earth surface to earth orbit of a fully reusable single-stage-to-orbit pure rocket launch vehicle is derived. Of interest are both the optimal operation of the propulsion system and the optimal flight path. A methodology is developed to investigate the optimal throttle switching of dual-fuel engines. The method is based on selecting propulsion system modes and parameters that maximize a certain performance function. This function is derived from consideration of the energy-state model of the aircraft equations of motion. Because the density of liquid hydrogen is relatively low, the sensitivity of perturbations in volume need to be taken into consideration as well as weight sensitivity. The cost functional is a weighted sum of fuel mass and volume; the weighting factor is chosen to minimize vehicle empty weight for a given payload mass and volume in orbit.

  9. Anticipatory guidance through DVD.

    Science.gov (United States)

    Franz, Sandra; McMahon, Pamela M; Calongne, Laurinda; Steele-Moses, Susan K

    2014-03-01

    The major purpose of the study was to determine if a 5-minute DVD is an effective method for communicating anticipatory guidance to parents at their child's 4-month well-child visit. A total of 84 caregivers were randomly assigned to receive anticipatory guidance through standard care (written anticipatory guidance handout and free talk) or DVD (DVD format + standard care). Participants completed a brief questionnaire immediately before and after their visit. As anticipated, knowledge scores improved significantly from pre-test to post-test. There was also a significant interaction between format used for anticipatory guidance and time. Specifically, there was greater improvement in knowledge over time for parents in the DVD group as compared with the standard care group. Additionally, the mean knowledge level of those in the DVD group as compared with those in the standard care group trended toward significance. Finally, visit length was shortened by nearly 3 minutes in the DVD group, and close to 100% of all respondents, regardless of anticipatory guidance format, indicated that they were very satisfied with their visit and amount of information learned.

  10. Study on Guidance Law of UAV Net Recovery System

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yi; ZHAO Shao-song; WANG Yong-sheng; ZHANG Yu-zhuo

    2007-01-01

    The design and realization of a net recovery system is introduced, which can recover UAV (unmanned aerial vehicle) reliably and safely. The mathematical model is built, and the horizontal and vertical guidance law is studied based on the aerodynamic parameters and actual flying trial data of a certain UAV. The simulation result shows that this system can realize the recovery safely, stably and accurately.

  11. Development of a tabletop guidance system for educational robots

    NARCIS (Netherlands)

    Bac, C.W.; Grift, T.E.; Menezes, G.

    2011-01-01

    The guidance of a vehicle in an outdoor setting is typically implemented using a Real Time Kinematic Global Positioning System (RTK-GPS) potentially enhanced by auxiliary sensors such as electronic compasses, rotation encoders, gyroscopes, and vision systems. Since GPS does not function in an indoor

  12. Guidance and Control Architecture Design and Demonstration for Low Ballistic Coefficient Atmospheric Entry

    Science.gov (United States)

    Swei, Sean

    2014-01-01

    We propose to develop a robust guidance and control system for the ADEPT (Adaptable Deployable Entry and Placement Technology) entry vehicle. A control-centric model of ADEPT will be developed to quantify the performance of candidate guidance and control architectures for both aerocapture and precision landing missions. The evaluation will be based on recent breakthroughs in constrained controllability/reachability analysis of control systems and constrained-based energy-minimum trajectory optimization for guidance development operating in complex environments.

  13. Predictive Terminal Guidance With Tuning of Prediction Horizon & Constrained Control .

    Directory of Open Access Journals (Sweden)

    S. E. Talole

    2000-07-01

    Full Text Available Continvojs time-predictive control approach is employed to formulate an output tracking nonlinear, optimal, terminal guidance ,law for re-entry vehicles. The notable features of this formulation are that the system equations are not linearised and the evaluation of the guidanceequations does not need the information of vehicle parameters, such as drag and mass. The formulation allows to impose the physical constrains on the control inputs, i..e. on the demanded lateral acceleliations through a saturation mapping and the controls are obtained using a fixed pointiteration algorithm which converges typically in a few iterations. Further, a simple method of tuning the prediction horizon needed in the guidance equations is presented. Numerical simulations show that the guidance law achieves almost zero terminal errors in all states despite large errors in initial Conditions.

  14. Reach on laser imaging technology to terminal guidance

    Science.gov (United States)

    Tan, Xue-chun; Jin, Guang-yong; Wu, Zhi-chao; Ling, Ming; Liang, Zhu

    2009-07-01

    The development of range-imaging devices is motivated by various ground and space applications. Tasks in space missions include docking, rendezvous, manipulating robotic arms, landing and autonomous rover applications, sample identification and surface mapping. The ground applications include the guidance of vehicles, robotic and manipulator arms, and other autonomous or teleoperated machines, as well as surface or construction model generation. Without the scanner devices, scannerless imaging lidars have the characteristic of high frame rate, wide field of view and high reliability,which can be successful used in terminal guidance. Diode pumped laser radar with high repetition rate is studied in this paper. A bistatic system is set up and a high speed signal processor for the system is researched. In a conceptual sense, the imaging lidar has two parts, a transmitter and a receiver. Their field of views overlap throughout the measuring range.The imaging lidar operates as follows. Based on principle of pulsed time-of-flight (TOF) laser range finding, the solid-state laser diode-pumped laser produces short laser pulses, which though the expanded lens, then reach the target. The back reflected light is collected with a receiver lens and fed through optical fibres to discrete avalanche photo diodes (APDs). When a received pulse is detected by the comparator a time to digital converter (TDC) stops counting and a time interval, corresponding to the range, is produced. The precision of a single measurement is about +/-4.0cm, but better precision is achieved by averaging. Information about the reflectivity of the target is gathered by recording the amplitude of the received pulse. Range images with the lidar prototype were taken indoors, the measuring distance was about 14m.

  15. Vision-based vehicle detection and tracking algorithm design

    Science.gov (United States)

    Hwang, Junyeon; Huh, Kunsoo; Lee, Donghwi

    2009-12-01

    The vision-based vehicle detection in front of an ego-vehicle is regarded as promising for driver assistance as well as for autonomous vehicle guidance. The feasibility of vehicle detection in a passenger car requires accurate and robust sensing performance. A multivehicle detection system based on stereo vision has been developed for better accuracy and robustness. This system utilizes morphological filter, feature detector, template matching, and epipolar constraint techniques in order to detect the corresponding pairs of vehicles. After the initial detection, the system executes the tracking algorithm for the vehicles. The proposed system can detect front vehicles such as the leading vehicle and side-lane vehicles. The position parameters of the vehicles located in front are obtained based on the detection information. The proposed vehicle detection system is implemented on a passenger car, and its performance is verified experimentally.

  16. Vocational Guidance for Everyone

    Science.gov (United States)

    Holland, John L.

    1974-01-01

    Describes some of the current problems of vocational guidance, summarizes relevant knowledge and theory in the field, and offers some practical plans for a coordinated, theoretically compatible group of vocational programs, services, and experiences for a high school. (Author/JM)

  17. PIV Logon Configuration Guidance

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Glen Alan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-03-04

    This document details the configurations and enhancements implemented to support the usage of federal Personal Identity Verification (PIV) Card for logon on unclassified networks. The guidance is a reference implementation of the configurations and enhancements deployed at the Los Alamos National Laboratory (LANL) by Network and Infrastructure Engineering – Core Services (NIE-CS).

  18. Regulatory guidance document

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-05-01

    The Office of Civilian Radioactive Waste Management (OCRWM) Program Management System Manual requires preparation of the OCRWM Regulatory Guidance Document (RGD) that addresses licensing, environmental compliance, and safety and health compliance. The document provides: regulatory compliance policy; guidance to OCRWM organizational elements to ensure a consistent approach when complying with regulatory requirements; strategies to achieve policy objectives; organizational responsibilities for regulatory compliance; guidance with regard to Program compliance oversight; and guidance on the contents of a project-level Regulatory Compliance Plan. The scope of the RGD includes site suitability evaluation, licensing, environmental compliance, and safety and health compliance, in accordance with the direction provided by Section 4.6.3 of the PMS Manual. Site suitability evaluation and regulatory compliance during site characterization are significant activities, particularly with regard to the YW MSA. OCRWM`s evaluation of whether the Yucca Mountain site is suitable for repository development must precede its submittal of a license application to the Nuclear Regulatory Commission (NRC). Accordingly, site suitability evaluation is discussed in Chapter 4, and the general statements of policy regarding site suitability evaluation are discussed in Section 2.1. Although much of the data and analyses may initially be similar, the licensing process is discussed separately in Chapter 5. Environmental compliance is discussed in Chapter 6. Safety and Health compliance is discussed in Chapter 7.

  19. Career guidance on the move

    DEFF Research Database (Denmark)

    Thomsen, Rie

    2013-01-01

    This article is about how the notion of place can be used in an analysis of career guidance practices and their development. It is about how a focus on the context of career guidance can develop an awareness of the place where guidance is practiced and support the development of career guidance...... in new places. In this article I introduce an analytical perspective on place; I give the example of the guidance café a practice development that took place into serious consideration because it was an attempt to develop career guidance practice through relocating it....

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

    Directory of Open Access Journals (Sweden)

    Daxin Tian

    2015-01-01

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

  1. Fuzzy Logic Trajectory Design and Guidance for Terminal Area Energy Management

    Science.gov (United States)

    Burchett, Bradley

    2003-01-01

    The second generation reusable launch vehicle will leverage many new technologies to make flight to low earth orbit safer and more cost effective. One important capability will be completely autonomous flight during reentry and landing, thus making it unnecessary to man the vehicle for cargo missions with stringent weight constraints. Implementation of sophisticated new guidance and control methods will enable the vehicle to return to earth under less than favorable conditions. The return to earth consists of three phases--Entry, Terminal Area Energy Management (TAEM), and Approach and Landing. The Space Shuttle is programmed to fly all three phases of flight automatically, and under normal circumstances the astronaut-pilot takes manual control only during the Approach and Landing phase. The automatic control algorithms used in the Shuttle for TAEM and Approach and Landing have been developed over the past 30 years. They are computationally efficient, and based on careful study of the spacecraft's flight dynamics, and heuristic reasoning. The gliding return trajectory is planned prior to the mission, and only minor adjustments are made during flight for perturbations in the vehicle energy state. With the advent of the X-33 and X-34 technology demonstration vehicles, several authors investigated implementing advanced control methods to provide autonomous real-time design of gliding return trajectories thus enhancing the ability of the vehicle to adjust to unusual energy states. The bulk of work published to date deals primarily with the approach and landing phase of flight where changes in heading angle are small, and range to the runway is monotonically decreasing. These benign flight conditions allow for model simplification and fairly straightforward optimization. This project focuses on the TAEM phase of flight where mathematically precise methods have produced limited results. Fuzzy Logic methods are used to make onboard autonomous gliding return trajectory

  2. Entry, Descent, and Landing Guidance and Control Approaches to Satisfy Mars Human Mission Landing Criteria

    Science.gov (United States)

    Dwyer Cianciolo, Alicia; Powell, Richard W.

    2017-01-01

    Precision landing on Mars is a challenge. All Mars lander missions prior to the 2012 Mars Science Laboratory (MSL) had landing location uncertainty ellipses on the order of hundreds of kilometers. Sending humans to the surface of Mars will likely require multiple landers delivered in close proximity, which will in turn require orders of magnitude improvement in landing accuracy. MSL was the first Mars mission to use an Apollo-derived bank angle guidance to reduce the size of the landing ellipse. It utilized commanded bank angle magnitude to control total range and bank angle reversals to control cross range. A shortcoming of this bank angle guidance is that the open loop phase of flight created by use of bank reversals increases targeting errors. This paper presents a comparison of entry, descent and landing performance for a vehicle with a low lift-to-drag ratio using both bank angle control and an alternative guidance called Direct Force Control (DFC). DFC eliminates the open loop flight errors by directly controlling two forces independently, lift and side force. This permits independent control of down range and cross range. Performance results, evaluated using the Program to Optimize Simulated Trajectories (POST2), including propellant use and landing accuracy, are presented.

  3. Advanced Control System Design for Hypersonic Vehicles Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Guidance and control system design for hypersonic vehicles is more challenging than their subsonic and supersonic counterparts. Some of these challenges are (i)...

  4. Electric vehicles

    Science.gov (United States)

    1990-03-01

    Quiet, clean, and efficient, electric vehicles (EVs) may someday become a practical mode of transportation for the general public. Electric vehicles can provide many advantages for the nation's environment and energy supply because they run on electricity, which can be produced from many sources of energy such as coal, natural gas, uranium, and hydropower. These vehicles offer fuel versatility to the transportation sector, which depends almost solely on oil for its energy needs. Electric vehicles are any mode of transportation operated by a motor that receives electricity from a battery or fuel cell. EVs come in all shapes and sizes and may be used for different tasks. Some EVs are small and simple, such as golf carts and electric wheel chairs. Others are larger and more complex, such as automobile and vans. Some EVs, such as fork lifts, are used in industries. In this fact sheet, we will discuss mostly automobiles and vans. There are also variations on electric vehicles, such as hybrid vehicles and solar-powered vehicles. Hybrid vehicles use electricity as their primary source of energy, however, they also use a backup source of energy, such as gasoline, methanol or ethanol. Solar-powered vehicles are electric vehicles that use photovoltaic cells (cells that convert solar energy to electricity) rather than utility-supplied electricity to recharge the batteries. These concepts are discussed.

  5. A Further Look at X-33 Entry Guidance and Beyond

    Science.gov (United States)

    Lu, Ping

    1999-01-01

    An entry guidance design developed at Iowa State University (ISU) for the X-33 advanced technology demonstrator is outlined and compared with the X-33 entry guidance algorithms developed at NASA Marshall. Both designs are based on the Space Shuttle entry guidance concept, but significant improvements have been made to enhance the performance and reduce the complexity. The ISU design was incorporated into MAVERIC, a high fidelity vehicle simulation software for the X-33, and evaluated in Monte Carlo simulations against random dispersions in propulsion system, wind and atmospheric properties, aerodynamic coefficients, interaction between propulsion and aerodynamics, and navigation data. The simulations clearly demonstrated the capability and precision of the ISU entry guidance design in successfully guiding the X-33 in some rather difficult flight scenarios. As the entry guidance development for the X-33 is completing, this report also offers some review of the strength and limitations of the current Shuttle-based entry guidance framework, and finally some potential candidates for next generation of more capable and cost-effective entry guidance designs are discussed.

  6. Islamic Guidance for Drug Addiction

    Directory of Open Access Journals (Sweden)

    Agus Supriyanto

    2016-10-01

    Full Text Available Islamic Guidance is social rehabilitation program for Drug Addiction (resident. The goal of this research to know the Islamic guidance for resident at the Center for Rehabilitation of the National Narcotics Agency Lido Bogor. The methodology in this research is qualitative descriptive, with a sample two religious counselor. Can be concluded that Islamic guidance is implemented with the classical format, group format, and individual formats. The goal of the Islamic Guidance to develop religious mentally.

  7. Islamic Guidance for Drug Addiction

    OpenAIRE

    Agus Supriyanto

    2016-01-01

    Islamic Guidance is social rehabilitation program for Drug Addiction (resident). The goal of this research to know the Islamic guidance for resident at the Center for Rehabilitation of the National Narcotics Agency Lido Bogor. The methodology in this research is qualitative descriptive, with a sample two religious counselor. Can be concluded that Islamic guidance is implemented with the classical format, group format, and individual formats. The goal of the Islamic Guidance to develop religio...

  8. 78 FR 67442 - Congestion Mitigation and Air Quality Improvement Program Interim Guidance

    Science.gov (United States)

    2013-11-12

    .... Bicycle and Pedestrian Facilities Programs The Interim Guidance explains that CMAQ eligibility is available to programs authorized in the bicycle and pedestrian programs governed by 23 CFR Part 652, with an... scope of CMAQ eligibility for electric vehicle charging stations and natural gas vehicle refueling...

  9. PROFESSIONAL GUIDANCE: EXPERIENCE REPORT

    Directory of Open Access Journals (Sweden)

    Fabiana Pinto de Almeida Bizarria

    2014-05-01

    Full Text Available This article presents an account of a career guidance with a group of five teenagers ( 16 and 19 , students of pre-university preparatory course offered by a public university in the state of Ceará . The work group dynamics was from a privileged form of performance by allowing a greater enrichment of the discussions , considering the heterogeneity and diversity of the group . To address relevant issues in career guidance based on the theory Socio-Historical , a roadmap of action process was constructed from three axes . Each axis has worked in two sessions that match a date. The first axis called " meaning of choice," worked on thematic choice process . With regard to the axis " World of Work " was discussed idealizations and representations about the professions , the labor market and the vestibular / ESMS . Emotional links with the professions , skills and ideas on skills and information professions : Finally , the " self " axis, which contains the themes was developed .

  10. Sliding mode control based guidance law with impact angle constraint

    Institute of Scientific and Technical Information of China (English)

    Zhao Yao; Sheng Yongzhi; Liu Xiangdong

    2014-01-01

    The terminal guidance problem for an unpowered lifting reentry vehicle against a sta-tionary target is considered. In addition to attacking the target with high accuracy, the vehicle is also expected to achieve a desired impact angle. In this paper, a sliding mode control (SMC)-based guidance law is developed to satisfy the terminal angle constraint. Firstly, a specific sliding mode function is designed, and the terminal requirements can be achieved by enforcing both the sliding mode function and its derivative to zero at the end of the flight. Then, a backstepping approach is used to ensure the finite-time reaching phase of the sliding mode and the analytic expression of the control effort can be obtained. The trajectories generated by this method only depend on the initial and terminal conditions of the terminal phase and the instantaneous states of the vehicle. In order to test the performance of the proposed guidance law in practical application, numerical simulations are carried out by taking all the aerodynamic parameters into consideration. The effec-tiveness of the proposed guidance law is verified by the simulation results in various scenarios.

  11. Polydopamine-based surface modification of mesoporous silica nanoparticles as pH-sensitive drug delivery vehicles for cancer therapy.

    Science.gov (United States)

    Chang, Danfeng; Gao, Yongfeng; Wang, Lijun; Liu, Gan; Chen, Yuhan; Wang, Teng; Tao, Wei; Mei, Lin; Huang, Laiqiang; Zeng, Xiaowei

    2016-02-01

    A novel pH-sensitive drug delivery system of mesoporous silica nanoparticles (MSNs) which were modified by polydopamine (PDA) for controlled release of cationic amphiphilic drug desipramine (DES) was prepared. MSNs-DES-PDA were characterized in terms of size, size distribution, surface morphology, BET surface area, mesoporous size and pore volume, drug loading content and in vitro drug release profile. MSNs-DES-PDA had high drug loading content and pH sensitivity. The DES release profiles of MSNs-DES and MSNs-DES-PDA were totally different, and the drug release of MSNs-DES-PDA accelerated with increasing acidity. MSNs-DES-PDA can be internalized into cells. In vitro experiments demonstrated that MSNs-DES-PDA had higher cytotoxicity and inhibitory effects on acid sphingomyelinase than those of free DES. This drug delivery system was beneficial for controlled release and cancer therapy.

  12. Sustainable Federal Fleets: Deploying Electric Vehicles and Electric Vehicle Supply Equipment

    Energy Technology Data Exchange (ETDEWEB)

    2017-01-01

    The U.S. Department of Energy (DOE) Federal Energy Management Program (FEMP) helps federal agencies reduce petroleum consumption and increase alternative fuel use through its resources for Sustainable Federal Fleets. To assist agencies with the transition to plug-in electric vehicles (PEVs), including battery electric vehicles (BEVs) and plug-in hybrid electric vehicles (PHEVs), FEMP offers technical guidance on electric vehicle supply equipment (EVSE) installations and site-specific planning through partnerships with the National Renewable Energy Laboratory's (NREL's) EVSE Tiger Teams.

  13. Sensing and control for autonomous vehicles applications to land, water and air vehicles

    CERN Document Server

    Pettersen, Kristin; Nijmeijer, Henk

    2017-01-01

    This edited volume includes thoroughly collected on sensing and control for autonomous vehicles. Guidance, navigation and motion control systems for autonomous vehicles are increasingly important in land-based, marine and aerial operations. Autonomous underwater vehicles may be used for pipeline inspection, light intervention work, underwater survey and collection of oceanographic/biological data. Autonomous unmanned aerial systems can be used in a large number of applications such as inspection, monitoring, data collection, surveillance, etc. At present, vehicles operate with limited autonomy and a minimum of intelligence. There is a growing interest for cooperative and coordinated multi-vehicle systems, real-time re-planning, robust autonomous navigation systems and robust autonomous control of vehicles. Unmanned vehicles with high levels of autonomy may be used for safe and efficient collection of environmental data, for assimilation of climate and environmental models and to complement global satellite sy...

  14. Exponential Stabilization of Underactuated Vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Pettersen, K.Y.

    1996-12-31

    Underactuated vehicles are vehicles with fewer independent control actuators than degrees of freedom to be controlled. Such vehicles may be used in inspection of sub-sea cables, inspection and maintenance of offshore oil drilling platforms, and similar. This doctoral thesis discusses feedback stabilization of underactuated vehicles. The main objective has been to further develop methods from stabilization of nonholonomic systems to arrive at methods that are applicable to underactuated vehicles. A nonlinear model including both dynamics and kinematics is used to describe the vehicles, which may be surface vessels, spacecraft or autonomous underwater vehicles (AUVs). It is shown that for a certain class of underactuated vehicles the stabilization problem is not solvable by linear control theory. A new stability result for a class of homogeneous time-varying systems is derived and shown to be an important tool for developing continuous periodic time-varying feedback laws that stabilize underactuated vehicles without involving cancellation of dynamics. For position and orientation control of a surface vessel without side thruster a new continuous periodic feedback law is proposed that does not cancel any dynamics, and that exponentially stabilizes the origin of the underactuated surface vessel. A further issue considered is the stabilization of the attitude of an AUV. Finally, the thesis discusses stabilization of both position and attitude of an underactuated AUV. 55 refs., 28 figs.

  15. Sensorless Speed Control with Initial Rotor Position Estimation for Surface Mounted Permanent Magnet Synchronous Motor Drive in Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Xuan Wu

    2015-10-01

    Full Text Available The accurate information of the initial rotor position is very critical for successful starting of the Surface-mounted Permanent Magnet Synchronous Motor (SPMSM. In order to solve the problems of low accuracy and unreliability in the conventional estimation strategy, in this paper, an improved initial rotor position estimation strategy without any position sensor for SPMSM at standstill is proposed based on rectangular pulse voltage injection. In the work, when the second series of pulse voltages were applied. By the ways of strengthening the effect of weakening or strengthening magnetic fields and increasing the difference between each current of the vector. The improved strategy enhanced reliability and raised the initial position estimation accuracy from 7.5° to 1.875°. The improved strategy does not need any additional hardware. Experimental results demonstrate the validity and usefulness of the improved strategy.

  16. PSD Increment Consumption Guidance

    Science.gov (United States)

    This document may be of assistance in applying the New Source Review (NSR) air permitting regulations including the Prevention of Significant Deterioration (PSD) requirements. This document is part of the NSR Policy and Guidance Database. Some documents in the database are a scanned or retyped version of a paper photocopy of the original. Although we have taken considerable effort to quality assure the documents, some may contain typographical errors. Contact the office that issued the document if you need a copy of the original.

  17. Anticipating behaviour in supervisory vehicle control

    NARCIS (Netherlands)

    Breda, L. van

    1999-01-01

    Vehicle control may be considered as a hierarchically structured set of functions. Plan conception and plan selection activities are performed in the navigation function, verification and adjustment of the short-term voyage progress are performed in the guidance function, and typical closed-loop con

  18. Guidance of Nonlinear Systems

    Science.gov (United States)

    Meyer, George

    1997-01-01

    The paper describes a method for guiding a dynamic system through a given set of points. The paradigm is a fully automatic aircraft subject to air traffic control (ATC). The ATC provides a sequence of way points through which the aircraft trajectory must pass. The way points typically specify time, position, and velocity. The guidance problem is to synthesize a system state trajectory which satisfies both the ATC and aircraft constraints. Complications arise because the controlled process is multi-dimensional, multi-axis, nonlinear, highly coupled, and the state space is not flat. In addition, there is a multitude of possible operating modes, which may number in the hundreds. Each such mode defines a distinct state space model of the process by specifying the state space coordinatization, the partition of the controls into active controls and configuration controls, and the output map. Furthermore, mode transitions must be smooth. The guidance algorithm is based on the inversion of the pure feedback approximations, which is followed by iterative corrections for the effects of zero dynamics. The paper describes the structure and modules of the algorithm, and the performance is illustrated by several example aircraft maneuvers.

  19. Assessment of Adaptive Guidance for Responsive Launch Vehicles and Spacecraft

    Science.gov (United States)

    2009-04-29

    the multiplier vector ν and obtain (V Tf prf )r 2 f − (rTf pVf )V 2f + (rTf V f )(V 2f − rTf prf ) = 0 (5) V Tf pVf − V 2f = 0 (6) ( hTf prf )[h T f (rf...1N)] + ( hTf pVf )[ hTf (V f × 1N)] = 0 (7) The above 6 equations (2-7) constitute the terminal boundary conditions (3) for this case. To adjust the

  20. Abandoned vehicles

    CERN Multimedia

    Relations with the Host States Service

    2004-01-01

    The services in charge of managing the CERN site have recently noted an increase in the number of abandoned vehicles. This poses a risk from the point of view of safety and security and, on the eve of several important events in honour of CERN's fiftieth anniversary, is detrimental to the Organization's image. Owners of vehicles that have been left immobile for some time on the CERN site, including on the external car park by the flags, are therefore invited to contact the Reception and Access Control Service (service-parking-longterm@cern.ch) before 1st October 2004 and, where appropriate, move their vehicle to a designated long-term parking area. After this date, any vehicle whose owner has failed to respond to this request and which is without a number plate, has been stationary for several weeks or is out of service, may be impounded at the owner's risk and expense. Relations with the Host States Service Tel. 72848

  1. F-18 high alpha research vehicle surface pressures: Initial in-flight results and correlation with flow visualization and wind-tunnel data

    Science.gov (United States)

    Fisher, David F.; Banks, Daniel W.; Richwine, David M.

    1990-01-01

    Pressure distributions measured on the forebody and the leading-edge extensions (LEX's) of the NASA F-18 high alpha research vehicle (HARV) were reported at 10 and 50 degree angles of attack and at Mach 0.20 to 0.60. The results were correlated with HARV flow visualization and 6-percent scale F-18 wind-tunnel-model test results. The general trend in the data from the forebody was for the maximum suction pressure peaks to first appear at an angle of attack (alpha) of approximately 19 degrees and increase in magnitude with angle of attack. The LEX pressure distribution general trend was the inward progression and increase in magnitude of the maximum suction peaks up to vortex core breakdown and then the decrease and general flattening of the pressure distribution beyond that. No significant effect of Mach number was noted for the forebody results. However, a substantial compressibility effect on the LEX's resulted in a significant reduction in vortex-induced suction pressure as Mach number increased. The forebody primary and the LEX secondary vortex separation lines, from surface flow visualization, correlated well with the end of pressure recovery, leeward and windward, respectively, of maximum suction pressure peaks. The flight to wind-tunnel correlations were generally good with some exceptions.

  2. Rapid near-optimal aerospace plane trajectory generation and guidance

    Science.gov (United States)

    Corban, J. E.; Calise, A. J.; Flandro, G. A.

    1991-01-01

    Problems associated with onboard trajectory optimization, propulsion system cycle selection, and the synthesis of guidance laws are addressed for ascent to low earth orbit of an airbreathing, single-stage-to-orbit vehicle. A multicycle propulsion system is assumed that incorporates turbojet, ramjet, scramjet, and rocket engines. An energy state approximation is applied to a singularly perturbed, four-state dynamic model for flight of a point mass over a spherical nonrotating earth. An algorithm is then derived for generating both the fuel-optimal climb profile and the guidance commands required to follow that profile. In particular, analytic switching conditions are derived that, under appropriate assumptions, efficiently govern optimal transition from one propulsion cycle to another. The algorithm proves to be computationally efficient and suitable for real-time implementation. The paper concludes with the presentation of representative numerical results that illustrate the nature of the fuel-optimal climb paths and the tracking performance of the guidance algorithm.

  3. Método de avaliação de equipamentos para direcionamento de veículos agrícolas e efeito de sinais de GNSS Method for evaluation of guidance equipments for agricultural vehicles and GNSS signals effect

    Directory of Open Access Journals (Sweden)

    José P Molin

    2011-02-01

    Full Text Available Pesquisas indicam que o uso de novas técnicas no campo da mecanização agrícola, como o tráfego controlado por meio de direcionamento com auxílio de Sistemas de Navegação Global por Satélites (GNSS, pode diminuir as exigências por energia associadas às operações de campo e aumentar a produtividade da mão de obra e da cultura. Alguns autores já utilizaram diferentes metodologias para avaliar erros de paralelismo em sistemas de orientação de veículos, porém não há um procedimento-padrão para medi-los. Sendo assim, o objetivo deste trabalho foi implementar uma planilha eletrônica específica, determinar e comparar a acurácia no paralelismo de dois sistemas distintos de orientação de veículos (uma barra de luz e um piloto automático com atuador de volante em trajetórias retilíneas e utilizando sinal de GPS com dois sistemas de correção diferencial (um com algoritmo interno e outro, um sinal via satélite com acurácia submétrica. Para a avaliação dos sistemas de correção, utilizou-se como referência o sinal de correção diferencial RTK (Real Time Kinematic para realização de cinco passadas paralelas sucessivas para cada sistema de correção, caracterizando cinco repetições de cada tratamento. A planilha viabilizou o método de avaliação utilizado e os erros apresentados para as correções nos dois equipamentos analisados mostraram-se compatíveis com operações que exijam acurácia de paralelismo da ordem de decímetros.Researches indicate that the use of new techniques in agricultural machinery, as controlled traffic by steering systems with the use of Global Navigation Satellite Systems (GNSS may decrease the energy demand associated to field operations and increase labor efficiency and crop yield. Some authors already use different methodologies to evaluate the parallelism errors in guidance systems for vehicles, but there is no standard methodology to measure them. So, the objective of these work

  4. Guidance at the educational marketplace

    DEFF Research Database (Denmark)

    Lystbæk, Christian Tang

    in educational policies and institutions. As educational systems have expanded and, further, have been restructured with the expansion of choice opportunities since the 1980s, guidance has become prioritized as a form of counseling or coaching, which can support students. Thus, guidance has become an important...

  5. Guidance in the Secondary School

    Science.gov (United States)

    Kumar, V. Jurist Lional

    2010-01-01

    Secondary School Students face a lot of problems in their body as well as in mind due to puberty that tends to adolescence stage. Adolescence has peculiar characters of their own. They need proper Guidance and Counselling to tackle their own problems. Guidance is described as a counselling service to assist the individual in achieving self…

  6. Innovative Approaches to Career Guidance.

    Science.gov (United States)

    Freeman, Andrew R.

    A key part of a broad-based approach to career education in Australian schools is vocational/career guidance. Various vocational guidance programs have been developed for specific groups in Australian society, including work experience, caravans, and micrographics technology for the handicapped; pre-employment courses and a family education center…

  7. Final OSWER Vapor Intrusion Guidance

    Science.gov (United States)

    EPA is preparing to finalize its guidance on assessing and addressing vapor intrusion, which is defined as migration of volatile constituents from contaminated media in the subsurface (soil or groundwater) into the indoor environment. In November 2002, EPA issued draft guidance o...

  8. Restructuring Guidance and Counseling Programs.

    Science.gov (United States)

    Snyder, Beverly A.; Daly, Timothy P.

    1993-01-01

    Briefly reviews counseling profession's call for revitalization and transformation in school counseling and guidance programs. Summarizes one school system's efforts during late 1980s and early 1990s to transform its program from services and crisis orientation into a comprehensive developmental model based on Myrick's developmental guidance and…

  9. Hermes vehicle

    Science.gov (United States)

    Cretenet, J. C.

    1985-11-01

    The presence of Europe in the future developments of spatial programs, which are foreseen, for the 1990s and further, needs the availability of vehicles, modules and all related technologies adapted to operational use of low earth orbit station. The manned HERMES vehicle shall be part of the in-orbit infrastructure realized either in the European context or in cooperation between Europe and the United States. The main mission for this vehicle will be to run a shuttle with the station that means transport and change of the crews, its safe return in abort condition and cargo transport of consumable and experimental equipment. Secondary missions could be servicing on automatic platform, making autonomous scientific experiments. Lastly, the vehicle, by means of its on-board propulsion capability, could be used to accomplish in-orbit tow and assembly missions. Studies which are undertaken now about the vehicle are devoted to the aerodynamic shape (research of a compromise between aerothermic and overall fitting), the system (functional architecture, ground and flight configuration); further works dealing with technology are presently on hand in the field of thermal protection, aerodynamics, power generation with a high massic yield.

  10. Development of Micro Air Reconnaissance Vehicle as a Test Bed for Advanced Sensors and Electronics

    Science.gov (United States)

    Shams, Qamar A.; Vranas, Thomas L.; Fox, Robert L.; Kuhn, Theodore R.; Ingham, John; Logan, Michael J.; Barnes, Kevin N.; Guenther, Benjamin F.

    2002-01-01

    This paper describes the development of a Micro/Mini Air Reconnaissance Vehicle for advanced sensors and electronics at NASA Langley Research Center over the last year. This vehicle is expected to have a total weight of less than four pounds, a design velocity of 40 mph, an endurance of 15-20 minutes, and a maximum range of 5km. The vehicle has wings that are simple to detach yet retain the correct alignment. The upper fuselage surface has a quick release hatch used to access the interior and also to mount the varying propulsion systems. The sensor suite developed for this vehicle consists of a Pitot-static measurement system for determining air speed, an absolute pressure measurement for determining altitude, magnetic direction measurement, and three orthogonal gyros to determine body angular rates. Swarming GPS-guidance and in-flight maneuvering is discussed, as well as design and installation of some other advance sensors like MEMS microphones, infrared cameras, GPS, humidity sensors, and an ultrasonic sonar sensor. Also low cost, small size, high performance control and navigation system for the Micro Air Vehicle is discussed. At the end, laboratory characterization of different sensors, motors, propellers, and batteries will be discussed.

  11. A small-gain method for integrated guidance and control in terminal phase of reentry

    Science.gov (United States)

    Yan, Han; Tan, Shuping; He, Yingzi

    2017-03-01

    The guidance and control systems of reentry vehicles are usually designed separately and then integrated, but the scheme can be argued that synergistic relationships between the two subsystems are not fully exploited. In order to improve the performance of reusable launch vehicles (RLVs), this paper proposes an integrated guidance and control law for approach and landing of a RLV. According to the idea of reference-trajectory guidance, the angle of attack and bank angle commands are designed using sliding mode control (SMC) method to make the reference-trajectory tacking error converge into a small neighborhood of zero. An integrated guidance and control (IGC) law is developed utilizing generalized small-gain theorem to enforce the commands, and theoretical analysis shows that the law can guarantee the stability of the overall system. The Monte Carlo simulation confirms the effectiveness of the proposed design approach.

  12. electric vehicle

    Directory of Open Access Journals (Sweden)

    W. R. Lee

    1999-01-01

    Full Text Available A major problem facing battery-powered electric vehicles is in their batteries: weight and charge capacity. Thus, a battery-powered electric vehicle only has a short driving range. To travel for a longer distance, the batteries are required to be recharged frequently. In this paper, we construct a model for a battery-powered electric vehicle, in which driving strategy is to be obtained such that the total travelling time between two locations is minimized. The problem is formulated as an optimization problem with switching times and speed as decision variables. This is an unconventional optimization problem. However, by using the control parametrization enhancing technique (CPET, it is shown that this unconventional optimization is equivalent to a conventional optimal parameter selection problem. Numerical examples are solved using the proposed method.

  13. Unmanned Surface and Underwater Vehicles

    Science.gov (United States)

    2007-07-03

    Mine Counter Measure Vessel MIRIS Mine Reacquisition and Identification Sonar MMCM Maritime Mine Counter Measures MRS Mine Reconnaissance System MRU ...capability to monitor the oceans. * Seatex MRU 6 attitude sensor for magnetic heading, pitch and roll. * Digiquartz 430 kT 700 bar pressure sensor for depth

  14. GUIDANCE DOCUMENT ON IMPLEMENTATION OF THE ...

    Science.gov (United States)

    The Agreement in Principle for the Stage 2 M-DBP Federal Advisory Committee contains a list of treatment processes and management practices for water systems to use in meeting additional Cryptosporidium treatment requirements under the LT2ESWTR. This list, termed the microbial toolbox, includes watershed control programs, alternative intake locations, pretreatment processes, additional filtration barriers, inactivation technologies, and enhanced plant performance. The intent of the microbial toolbox is to provide water systems with broad flexibility in selecting cost-effective LT2ESWTR compliance strategies. Moreover, the toolbox allows systems that currently provide additional pathogen barriers or that can demonstrate enhanced performance to receive additional Cryptosporidium treatment credit. Provide guidance to utilities with surface water supplies and to state drinking water programs on the use of different treatment technologies to reduce the level of Cryptosporidium in drinking water. Technologies included in the guidance manual may be used to achieve compliance with the requirements of the LT2ESWTR.

  15. RH Packaging Program Guidance

    Energy Technology Data Exchange (ETDEWEB)

    Washington TRU Solutions LLC

    2008-01-12

    The purpose of this program guidance document is to provide the technical requirements for use, operation, inspection, and maintenance of the RH-TRU 72-B Waste Shipping Package (also known as the "RH-TRU 72-B cask") and directly related components. This document complies with the requirements as specified in the RH-TRU 72-B Safety Analysis Report for Packaging (SARP), and Nuclear Regulatory Commission (NRC) Certificate of Compliance (C of C) 9212. If there is a conflict between this document and the SARP and/or C of C, the C of C shall govern. The C of C states: "...each package must be prepared for shipment and operated in accordance with the procedures described in Chapter 7.0, Operating Procedures, of the application." It further states: "...each package must be tested and maintained in accordance with the procedures described in Chapter 8.0, Acceptance Tests and Maintenance Program of the Application." Chapter 9.0 of the SARP tasks the Waste Isolation Pilot Plant (WIPP) Management and Operating (M&O) Contractor with assuring the packaging is used in accordance with the requirements of the C of C. Because the packaging is NRC-approved, users need to be familiar with Title 10 Code of Federal Regulations (CFR) §71.8, "Deliberate Misconduct." Any time a user suspects or has indications that the conditions of approval in the C of C were not met, the U.S. Department of Energy (DOE) Carlsbad Field Office (CBFO) shall be notified immediately. The CBFO will evaluate the issue and notify the NRC if required.In accordance with 10 CFR Part 71, "Packaging and Transportation of Radioactive Material," certificate holders, packaging users, and contractors or subcontractors who use, design, fabricate, test, maintain, or modify the packaging shall post copies of (1) 10 CFR Part 21, "Reporting of Defects and Noncompliance," regulations, (2) Section 206 of the Energy Reorganization Act of 1974, and (3) NRC Form 3, Notice to Employees. These documents must be posted in a

  16. RH Packaging Program Guidance

    Energy Technology Data Exchange (ETDEWEB)

    Washington TRU Solutions LLC

    2006-11-07

    The purpose of this program guidance document is to provide the technical requirements for use, operation, inspection, and maintenance of the RH-TRU 72-B Waste Shipping Package and directly related components. This document complies with the requirements as specified in the RH-TRU 72-B Safety Analysis Report for Packaging (SARP), and Nuclear Regulatory Commission (NRC) Certificate of Compliance (C of C) 9212. If there is a conflict between this document and the SARP and/or C of C, the C of C shall govern. The C of C states: "...each package must be prepared for shipment and operated in accordance with the procedures described in Chapter 7.0, Operating Procedures, of the application." It further states: "...each package must be tested and maintained in accordance with the procedures described in Chapter 8.0, Acceptance Tests and Maintenance Program of the Application." Chapter 9.0 of the SARP tasks the Waste Isolation Pilot Plant (WIPP) Management and Operating (M&O) Contractor with assuring the packaging is used in accordance with the requirements of the C of C. Because the packaging is NRC-approved, users need to be familiar with 10 Code of Federal Regulations (CFR) §71.8, "Deliberate Misconduct." Any time a user suspects or has indications that the conditions of approval in the C of C were not met, the U.S. Department of Energy (DOE) Carlsbad Field Office (CBFO) shall be notified immediately. CBFO will evaluate the issue and notify the NRC if required. In accordance with 10 CFR Part 71, "Packaging and Transportation of Radioactive Material," certificate holders, packaging users, and contractors or subcontractors who use, design, fabricate, test, maintain, or modify the packaging shall post copies of (1) 10 CFR Part 21, "Reporting of Defects and Noncompliance," regulations, (2) Section 206 of the Energy Reorganization Act of 1974, and (3) NRC Form 3, Notice to Employees. These documents must be posted in a conspicuous location where the activities subject to

  17. Dynamic Surface and Active Disturbance Rejection Control for Path Following of an Underactuated UUV

    OpenAIRE

    Juan Li; Haitao Gao; Jiajia Zhou; Zheping Yan

    2014-01-01

    This paper addresses the problem of accurate path following control for an underactuated unmanned underwater vehicle (UUV) in the horizontal plane. For an underactuated UUV, the line-of-sight (LOS) guidance method is adopted to map 2D reference trajectory into a desired orientation, and through the tracking of heading to achieve path following, where the sideslip is introduced to modify the desired orientation. In this paper, we propose a method called dynamic surface and active disturbance r...

  18. Link!: Potential Field Guidance Algorithm for In-Flight Linking of Multi-Rotor Aircraft

    Science.gov (United States)

    Cooper, John R.; Rothhaar, Paul M.

    2017-01-01

    Link! is a multi-center NASA e ort to study the feasibility of multi-aircraft aerial docking systems. In these systems, a group of vehicles physically link to each other during flight to form a larger ensemble vehicle with increased aerodynamic performance and mission utility. This paper presents a potential field guidance algorithm for a group of multi-rotor vehicles to link to each other during flight. The linking is done in pairs. Each vehicle first selects a mate. Then the potential field is constructed with three rules: move towards the mate, avoid collisions with non-mates, and stay close to the rest of the group. Once a pair links, they are then considered to be a single vehicle. After each pair is linked, the process repeats until there is only one vehicle left. The paper contains simulation results for a system of 16 vehicles.

  19. Rumble surfaces

    CSIR Research Space (South Africa)

    National Institute for Transport and Road

    1977-01-01

    Full Text Available Rumble surfaces are intermittent short lengths of coarse-textured road surfacings on which vehicle tyres produce a rumbling sound. used in conjunction with appropriate roadsigns and markings, they can reduce accidents on rural roads by alerting...

  20. Hybrid vehicles

    Energy Technology Data Exchange (ETDEWEB)

    West, J.G.W. [Electrical Machines (United Kingdom)

    1997-07-01

    The reasons for adopting hybrid vehicles result mainly from the lack of adequate range from electric vehicles at an acceptable cost. Hybrids can offer significant improvements in emissions and fuel economy. Series and parallel hybrids are compared. A combination of series and parallel operation would be the ideal. This can be obtained using a planetary gearbox as a power split device allowing a small generator to transfer power to the propulsion motor giving the effect of a CVT. It allows the engine to run at semi-constant speed giving better fuel economy and reduced emissions. Hybrid car developments are described that show the wide range of possible hybrid systems. (author)

  1. Optofluidic control of axonal guidance

    Science.gov (United States)

    Gu, Ling; Ordonez, Simon; Black, Bryan; Mohanty, Samarendra K.

    2013-03-01

    Significant efforts are being made for control on axonal guidance due to its importance in nerve regeneration and in the formation of functional neuronal circuitry in-vitro. These include several physical (topographic modification, optical force, and electric field), chemical (surface functionalization cues) and hybrid (electro-chemical, photochemical etc) methods. Here, we report comparison of the effect of linear flow versus microfluidic flow produced by an opticallydriven micromotor in guiding retinal ganglion axons. A circularly polarized laser tweezers was used to hold, position and spin birefringent calcite particle near growth cone, which in turn resulted in microfluidic flow. The flow rate and resulting shear-force on axons could be controlled by a varying the power of the laser tweezers beam. The calcite particles were placed separately in one chamber and single particle was transported through microfluidic channel to another chamber containing the retina explant. In presence of flow, the turning of axons was found to strongly correlate with the direction of flow. Turning angle as high as 90° was achieved. Optofluidic-manipulation can be applied to other types of mammalian neurons and also can be extended to stimulate mechano-sensing neurons.

  2. Electric-Drive Vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Septon, Kendall K [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-09-11

    Electric-drive vehicles use electricity as their primary fuel or to improve the efficiency of conventional vehicle designs. These vehicles can be divided into three categories: Hybrid electric vehicles (HEVs), Plug-in hybrid electric vehicles (PHEVs), All-electric vehicles (EVs). Together, PHEVs and EVs can also be referred to as plug-in electric vehicles (PEVs).

  3. Pandemic influenza guidance for corporations.

    Science.gov (United States)

    2011-06-01

    The purpose of this guidance document is to assist members of the American College of Occupational and Environmental Medicine (ACOEM), and the organizations for which they work, in managing the impact of a pandemic of influenza or other contagious respiratory disease on patients, employees, and business. This guidance document outlines actions to take before and during an influenza pandemic on the basis of two main strategies: (1) reducing the spread of the virus within facilities; and (2) providing medical care and medical surveillance to client/patient populations. Facilities in which ACOEM members serve include government agencies and the military, universities, and corporations, which generally have multiple locations/sites and their own medical staff, with members responsible for medical care and disease control. This guidance is for organizations with outpatient occupational medicine services, to be used as appropriate. Medical centers should also use guidance that addresses additional employee and external patient care needs.1–3 The ACOEM fully supports implementation of occupational influenza programs that conform with guidance from the Centers for Disease Control and Prevention (CDC), with other guidance from the US Department of Health and Human Services (DHHS), and Occupational Safety and Health Administration (OSHA) regulations and guidance.

  4. Adaptive Critic Neural Network-Based Terminal Area Energy Management and Approach and Landing Guidance

    Science.gov (United States)

    Grantham, Katie

    2003-01-01

    Reusable Launch Vehicles (RLVs) have different mission requirements than the Space Shuttle, which is used for benchmark guidance design. Therefore, alternative Terminal Area Energy Management (TAEM) and Approach and Landing (A/L) Guidance schemes can be examined in the interest of cost reduction. A neural network based solution for a finite horizon trajectory optimization problem is presented in this paper. In this approach the optimal trajectory of the vehicle is produced by adaptive critic based neural networks, which were trained off-line to maintain a gradual glideslope.

  5. RH Packaging Program Guidance

    Energy Technology Data Exchange (ETDEWEB)

    Washington TRU Solutions, LLC

    2003-08-25

    The purpose of this program guidance document is to provide technical requirements for use, operation, inspection, and maintenance of the RH-TRU 72-B Waste Shipping Package and directly related components. This document complies with the requirements as specified in the RH-TRU 72-B Safety Analysis Report for Packaging (SARP), and Nuclear Regulatory Commission (NRC) Certificate of Compliance (C of C) 9212. If there is a conflict between this document and the SARP and/or C of C, the SARP and/or C of C shall govern. The C of C states: ''...each package must be prepared for shipment and operated in accordance with the procedures described in Chapter 7.0, ''Operating Procedures,'' of the application.'' It further states: ''...each package must be tested and maintained in accordance with the procedures described in Chapter 8.0, ''Acceptance Tests and Maintenance Program of the Application.'' Chapter 9.0 of the SARP tasks the Waste Isolation Pilot Plant (WIPP) Management and Operating (M&O) contractor with assuring the packaging is used in accordance with the requirements of the C of C. Because the packaging is NRC approved, users need to be familiar with 10 CFR {section} 71.11, ''Deliberate Misconduct.'' Any time a user suspects or has indications that the conditions of approval in the C of C were not met, the Carlsbad Field Office (CBFO) shall be notified immediately. CBFO will evaluate the issue and notify the NRC if required. This document details the instructions to be followed to operate, maintain, and test the RH-TRU 72-B packaging. This Program Guidance standardizes instructions for all users. Users shall follow these instructions. Following these instructions assures that operations are safe and meet the requirements of the SARP. This document is available on the Internet at: ttp://www.ws/library/t2omi/t2omi.htm. Users are responsible for ensuring they are using the current

  6. CAREER GUIDANCE EXPERIENCE ABROAD

    Directory of Open Access Journals (Sweden)

    Sergey N. Tolstoguzov

    2015-01-01

    Full Text Available The aim of this paper is to describe the experience of careeroriented activities carried out with students of schools in developed and developing countries. Career Guidance in Russia, despite the vast experience of its implementation, is experiencing serious difficulties. In this regard, it is important to take into account the international experience career-oriented activities, such as in the developed countries of North America and the European Union as well as in several Asian countries with rapidly growing economies and a large demographic potential, taking into account the best variants for the Russian education system. Methods. The experience of career-oriented work undertaken with pupils of the USA, Canada, Israel, France, UK, Germany, Denmark, Sweden, Japan, Singapore, China and India is shown on the basis of the comparative analysis of different publications and information sources. The author has made an attempt to generalize the principles of psycho-pedagogical and administrative assistance in professional self-determination of senior pupils abroad. Scientific novelty. The approaches to career-oriented activities in countries with different levels of economic development are compared for the first time. Some principles are revealed. Firstly, the higher the income level per capita in the country, the greater attention is given to vocational guidance. The politics in the developed countries is based on interests of the individual: children’s acquaintance with the world of professions begins already at younger school and the moment of definitive selfdetermination is postponed till the end of their senior stage of education; the possibility of direction change of professional preparation in case of detection of discrepancy of qualities of the pupil to originally selected profile is provided. Career-oriented activity in developing countries, on the contrary, is rigidly coordinated to requirements of economy and a labour market

  7. Following Control for a UUV using Temporary Path Generation Guidance

    Institute of Scientific and Technical Information of China (English)

    Zheping Yan; Dongnan Chi; Jiajia Zhou; Yufei Zhao

    2012-01-01

    A path following control algorithm for an unmanned underwater vehicle (UUV) using temporary path generation guidance was proposed in this paper.Owing to different initial states of the vehicle,such as position and orientation,the path following control in the horizontal plane may yield a poor performance.To deal with the negative effect induced by initial states,a temporary path generation was presented based on the relationship between the original reference path and the vehicle's initial states.With different relative positions between the vehicle and reference path,including out of straight lines,as well as inside and outside a circle,the related temporary paths guiding the vehicle to the reference path were able to be generated in real time.The vehicle was guided to steer along the temporary path until it reached the tangent point at the reference path,where the controller was designed using the input-output feedback linearization method.Simulation results demonstrated that the proposed algorithm is effective under the three different situations mentioned above.

  8. Recent advances in remote coal mining machine sensing, guidance, and teleoperation

    Energy Technology Data Exchange (ETDEWEB)

    Ralston, J.C.; Hainsworth, D.W.; Reid, D.C.; Anderson, D.L.; McPhee, R.J. [CSIRO Exploration & Minerals, Kenmore, Qld. (Australia)

    2001-10-01

    Some recent applications of sensing, guidance and telerobotic technology in the coal mining industry are presented. Of special interest is the development of semi or fully autonomous systems to provide remote guidance and communications for coal mining equipment. The use of radar and inertial based sensors are considered in an attempt to solve the horizontal and lateral guidance problems associated with mining equipment automation. Also described is a novel teleoperated robot vehicle with unique communications capabilities, called the Numbat, which is used in underground mine safety and reconnaissance missions.

  9. Guidance, Navigation and Control of Unmanned Airships under Time-Varying Wind for Extended Surveillance

    Directory of Open Access Journals (Sweden)

    Ghassan Atmeh

    2016-02-01

    Full Text Available This paper deals with the control of lighter-than-air vehicles, more specifically the design of an integrated guidance, navigation and control (GNC scheme that is capable of navigating an airship through a series of constant-altitude, planar waypoints. Two guidance schemes are introduced, a track-specific guidance law and a proportional navigation guidance law, that provide the required signals to the corresponding controllers based on the airship position relative to a target waypoint. A novel implementation of the extended Kalman filter, namely the scheduled extended Kalman filter, estimates the required states and wind speed to enhance the performance of the track-specific guidance law in the presence of time-varying wind. The performance of the GNC system is tested using a high fidelity nonlinear dynamic simulation for a variety of flying conditions. Representative results illustrate the performance of the integrated system for chosen flight conditions.

  10. Effect of vehicle speed and roadway surface condition on the random dynamic loads of the wheels%车轮随机动载与路面及车速相互关系的研究

    Institute of Scientific and Technical Information of China (English)

    郑泉; 杨方廷

    2001-01-01

    文章利用车辆的两自由度模型,分析了车速与路 面不平度对车轮随机动载的功率谱密度和方差变化趋势的影响。同时也分析了车轮随机动载 的大小对路面疲劳应力的影响,指出了不同的车速和路面状况引起的路面动力反应及损伤变 化规律的不同,提出了针对路面状况来调整车速可以降低车轮随机动载,从而达到减轻对路 面损伤的要求。%By setting up a two-degree-of-freedom vehicle mode l,this paper analyzes the effect of vehicle speed and roadway surface condition on the random dynamic loads of the wheels. The effect of the random dynamic load s of the wheels on the fatigue stress of the roadway is also analyzed. The analy tic result shows that the different vehicle speed and roadway surface condition cause different changes in the dynamic response and fatigue damage of the roadwa y.It is put forward that the demand of reducing the random dynamic loads of the wheels can be met by properly considering the relation between vehicle speed an d roadway surface condition,so that the damage of the roadway can be decreased.

  11. CDM Convective Forecast Planning guidance

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The CDM Convective Forecast Planning (CCFP) guidance product provides a foreast of en-route aviation convective hazards. The forecasts are updated every 2 hours and...

  12. Response to work activity guidance

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This memorandum is concerning the request from the FY95 Platte-Kansas Rivers Ecosystem Work Activity Guidance for refuge managers to review the purposes of refuges...

  13. TSCA Inventory Policy and Guidance

    Science.gov (United States)

    A list of numerous policy statements and guidance documents on how to identify certain chemical substances for the purpose of assigning unique and unambiguous descriptions tor each substance listed on the Inventory.

  14. Guidance Systems of Fighter Aircraft

    Directory of Open Access Journals (Sweden)

    K.N. Rajanikanth

    2005-07-01

    Full Text Available Mission performance of a fighter aircraft is crucial for survival and strike capabilities in todays' aerial warfare scenario. The guidance functions of such an aircraft play a vital role inmeeting the requirements and accomplishing the mission success. This paper presents the requirements of precision guidance for various missions of a fighter aircraft. The concept ofguidance system as a pilot-in-loop system is pivotal in understanding and designing such a system. Methodologies of designing such a system are described.

  15. Guidance Systems of Fighter Aircraft

    OpenAIRE

    K.N. Rajanikanth; Rao, R S; P. S. Subramanyam; Ajai Vohra

    2005-01-01

    Mission performance of a fighter aircraft is crucial for survival and strike capabilities in todays' aerial warfare scenario. The guidance functions of such an aircraft play a vital role inmeeting the requirements and accomplishing the mission success. This paper presents the requirements of precision guidance for various missions of a fighter aircraft. The concept ofguidance system as a pilot-in-loop system is pivotal in understanding and designing such a system. Methodologies of designing s...

  16. Guidance molecules in lung cancer

    OpenAIRE

    Nasarre, Patrick; Potiron, Vincent; Drabkin, Harry; Roche, Joëlle

    2010-01-01

    Guidance molecules were first described in the nervous system to control axon outgrowth direction. They are also widely expressed outside the nervous system where they control cell migration, tissue development and establishment of the vascular network. In addition, they are involved in cancer development, tumor angiogenesis and metastasis. This review is primarily focused on their functions in lung cancer and their involvement in lung development is also presented. Five guidance molecule fam...

  17. 30 CFR 57.6802 - Bulk delivery vehicles.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Bulk delivery vehicles. 57.6802 Section 57.6802...-Surface and Underground § 57.6802 Bulk delivery vehicles. No welding or cutting shall be performed on a bulk delivery vehicle until the vehicle has been washed down and all explosive material has...

  18. Dynamics of vehicle-road coupled system

    CERN Document Server

    Yang, Shaopu; Li, Shaohua

    2015-01-01

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

  19. FY2014 Vehicle and Systems Simulation and Testing Annual Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    None

    2015-03-01

    The Vehicle and Systems Simulation and Testing research and development (R&D) subprogram within the DOE Vehicle Technologies Office (VTO) provides support and guidance for many cutting-edge automotive technologies under development. Research focuses on addressing critical barriers to advancing light-, medium-, and heavy-duty vehicle systems to help maximize the number of electric miles driven and increase the energy efficiency of transportation vehicles.

  20. Guidance and Control Software,

    Science.gov (United States)

    1980-05-01

    FACILITIES Integration Facilities exist for each project and consist of laboratory hot mockups of the actual military computers with realistic...PCIN Al. WEP I AND CONTROL AND CONTRI IF S TO R ESI I I I AIR-SURFACE ASGW WEAPONS I CONTROL L - - L - - - - - - - J L J FIG. 2a 3. HARDWARE

  1. Advanced entry guidance algorithm with landing footprint computation

    Science.gov (United States)

    Leavitt, James Aaron

    The design and performance evaluation of an entry guidance algorithm for future space transportation vehicles is presented. The algorithm performs two functions: on-board trajectory planning and trajectory tracking. The planned longitudinal path is followed by tracking drag acceleration, as is done by the Space Shuttle entry guidance. Unlike the Shuttle entry guidance, lateral path curvature is also planned and followed. A new trajectory planning function for the guidance algorithm is developed that is suitable for suborbital entry and that significantly enhances the overall performance of the algorithm for both orbital and suborbital entry. In comparison with the previous trajectory planner, the new planner produces trajectories that are easier to track, especially near the upper and lower drag boundaries and for suborbital entry. The new planner accomplishes this by matching the vehicle's initial flight path angle and bank angle, and by enforcing the full three-degree-of-freedom equations of motion with control derivative limits. Insights gained from trajectory optimization results contribute to the design of the new planner, giving it near-optimal downrange and crossrange capabilities. Planned trajectories and guidance simulation results are presented that demonstrate the improved performance. Based on the new planner, a method is developed for approximating the landing footprint for entry vehicles in near real-time, as would be needed for an on-board flight management system. The boundary of the footprint is constructed from the endpoints of extreme downrange and crossrange trajectories generated by the new trajectory planner. The footprint algorithm inherently possesses many of the qualities of the new planner, including quick execution, the ability to accurately approximate the vehicle's glide capabilities, and applicability to a wide range of entry conditions. Footprints can be generated for orbital and suborbital entry conditions using a pre

  2. FY2003 Annual Report: DOE Project on Heavy Vehicle Aerodynamic Drag

    Energy Technology Data Exchange (ETDEWEB)

    McCallen, R C; Salari, K; Ortega, J; DeChant, L J; Roy, C J; Payne, J J; Hassan, B; Pointer, W D; Browand, F; Hammache, M; Hsu, T; Ross, J; Satran, D; Heineck, J; Walker, S; Yaste, D; Englar, R; Leonard, A; Rubel, M; Chatelain, P

    2003-10-24

    Objective: {sm_bullet} Provide guidance to industry in the reduction of aerodynamic drag of heavy truck vehicles. {sm_bullet} Establish a database of experimental, computational, and conceptual design information, and demonstrate potential of new drag-reduction devices.

  3. Quality in career guidance: The Danish case

    DEFF Research Database (Denmark)

    Plant, Peter

    2011-01-01

    Quality assurance systems are introduced in career guidance to monitor, control and develop guidance interventions. The Danish case represents at centrally driven, top-down approach......Quality assurance systems are introduced in career guidance to monitor, control and develop guidance interventions. The Danish case represents at centrally driven, top-down approach...

  4. Current Trends in Tactical Missile Guidance

    Directory of Open Access Journals (Sweden)

    S. Vathsal

    2005-07-01

    Full Text Available The problem of tactical missile guidance is very challenging and has been treated using several basic metlfodologies in the past four decades. Major techniques can be grouped underclassical guidance laws, modern guidance laws, l'aws for manoeuvring targets, predictive guidance for endgame scenario, and guidance laws based on intelligent control methods. Each technique has some advantages and disadvantages while implementing in a practical system. Guidance law selection is dictated by nature of flight profile like boost, midcourse, terminal homing, etc, and also miss-distance and a single-shot kill probability. This paper presents a brief survey of the existing techniques and current trends in tactical missile guidance.

  5. Skidding accidents : considerations on road surface and vehicle characteristics : summary of the present situation. Provisional recommendation concerning skidding resistance of road surfaces investigation programme. Interim report of the SWOV Working Group "Tyres, road surfaces and skidding accidents"

    NARCIS (Netherlands)

    SWOV Working Group "Tyres, road surfaces and skidding accidents"

    1970-01-01

    This is the first report of SWOV Working Group "Tyres, road surfaces and skidding accidents". Skidding is considered to be an important contributory factor in traffic accidents. Skidding can in principle be prevented in two ways, viz: (1) reduction of the minimum necessary friction, and (2) increasi

  6. Optimal sliding guidance algorithm for Mars powered descent phase

    Science.gov (United States)

    Wibben, Daniel R.; Furfaro, Roberto

    2016-02-01

    Landing on large planetary bodies (e.g. Mars) with pinpoint accuracy presents a set of new challenges that must be addressed. One such challenge is the development of new guidance algorithms that exhibit a higher degree of robustness and flexibility. In this paper, the Zero-Effort-Miss/Zero-Effort-Velocity (ZEM/ZEV) optimal sliding guidance (OSG) scheme is applied to the Mars powered descent phase. This guidance algorithm has been specifically designed to combine techniques from both optimal and sliding control theories to generate an acceleration command based purely on the current estimated spacecraft state and desired final target state. Consequently, OSG yields closed-loop trajectories that do not need a reference trajectory. The guidance algorithm has its roots in the generalized ZEM/ZEV feedback guidance and its mathematical equations are naturally derived by defining a non-linear sliding surface as a function of the terms Zero-Effort-Miss and Zero-Effort-Velocity. With the addition of the sliding mode and using Lyapunov theory for non-autonomous systems, one can formally prove that the developed OSG law is globally finite-time stable to unknown but bounded perturbations. Here, the focus is on comparing the generalized ZEM/ZEV feedback guidance with the OSG law to explicitly demonstrate the benefits of the sliding mode augmentation. Results show that the sliding guidance provides a more robust solution in off-nominal scenarios while providing similar fuel consumption when compared to the non-sliding guidance command. Further, a Monte Carlo analysis is performed to examine the performance of the OSG law under perturbed conditions.

  7. Autonomous Aerodynamic Control of Micro Air Vehicles

    Science.gov (United States)

    2009-10-19

    technique based on the aerodynamic derivatives and gains set by the user. The user-set gains remain the same, but gains calculated from the...vehicle (MAV) research. Among these are: advanced modeling and simulation models for MAVs, aero-structural interaction, advanced guidance techniques ...flight. A. Wing-Fuselage Joint and Spring Mechanism Piano hinges are used to connect each wing to the fuselage and limit the wing motion to deflect

  8. Stereoscopic Vision System For Robotic Vehicle

    Science.gov (United States)

    Matthies, Larry H.; Anderson, Charles H.

    1993-01-01

    Distances estimated from images by cross-correlation. Two-camera stereoscopic vision system with onboard processing of image data developed for use in guiding robotic vehicle semiautonomously. Combination of semiautonomous guidance and teleoperation useful in remote and/or hazardous operations, including clean-up of toxic wastes, exploration of dangerous terrain on Earth and other planets, and delivery of materials in factories where unexpected hazards or obstacles can arise.

  9. Development of Velocity Guidance Assistance System by Haptic Accelerator Pedal Reaction Force Control

    Science.gov (United States)

    Yin, Feilong; Hayashi, Ryuzo; Raksincharoensak, Pongsathorn; Nagai, Masao

    This research proposes a haptic velocity guidance assistance system for realizing eco-driving as well as enhancing traffic capacity by cooperating with ITS (Intelligent Transportation Systems). The proposed guidance system generates the desired accelerator pedal (abbreviated as pedal) stroke with respect to the desired velocity obtained from ITS considering vehicle dynamics, and provides the desired pedal stroke to the driver via a haptic pedal whose reaction force is controllable and guides the driver in order to trace the desired velocity in real time. The main purpose of this paper is to discuss the feasibility of the haptic velocity guidance. A haptic velocity guidance system for research is developed on the Driving Simulator of TUAT (DS), by attaching a low-inertia, low-friction motor to the pedal, which does not change the original characteristics of the original pedal when it is not operated, implementing an algorithm regarding the desired pedal stroke calculation and the reaction force controller. The haptic guidance maneuver is designed based on human pedal stepping experiments. A simple velocity profile with acceleration, deceleration and cruising is synthesized according to naturalistic driving for testing the proposed system. The experiment result of 9 drivers shows that the haptic guidance provides high accuracy and quick response in velocity tracking. These results prove that the haptic guidance is a promising velocity guidance method from the viewpoint of HMI (Human Machine Interface).

  10. Encke-Beta Predictor for Orion Bum Targeting and Guidance

    Science.gov (United States)

    Robinson, Shane; Scarritt, Sara; Goodman, John L.

    2016-01-01

    The state vector prediction algorithm selected for Orion on-board targeting and guidance is known as the Encke-Beta method. Encke-Beta uses a universal anomaly (beta) as the independent variable, valid for circular, elliptical, parabolic, and hyperbolic orbits. The variable, related to the change in eccentric anomaly, results in integration steps that cover smaller arcs of the trajectory at or near perigee, when velocity is higher. Some burns in the EM-1 and EM-2 mission plans are much longer than burns executed with the Apollo and Space Shuttle vehicles. Burn length, as well as hyperbolic trajectories, has driven the use of the Encke-Beta numerical predictor by the predictor/corrector guidance algorithm in place of legacy analytic thrust and gravity integrals.

  11. Information architecture. Volume 3: Guidance

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-04-01

    The purpose of this document, as presented in Volume 1, The Foundations, is to assist the Department of Energy (DOE) in developing and promulgating information architecture guidance. This guidance is aimed at increasing the development of information architecture as a Departmentwide management best practice. This document describes departmental information architecture principles and minimum design characteristics for systems and infrastructures within the DOE Information Architecture Conceptual Model, and establishes a Departmentwide standards-based architecture program. The publication of this document fulfills the commitment to address guiding principles, promote standard architectural practices, and provide technical guidance. This document guides the transition from the baseline or defacto Departmental architecture through approved information management program plans and budgets to the future vision architecture. This document also represents another major step toward establishing a well-organized, logical foundation for the DOE information architecture.

  12. Autonomous Guidance, Navigation and Control

    Science.gov (United States)

    Bordano, A. J.; Mcswain, G. G.; Fernandes, S. T.

    1991-01-01

    The NASA Autonomous Guidance, Navigation and Control (GN&C) Bridging program is reviewed to demonstrate the program plan and GN&C systems for the Space Shuttle. The ascent CN&C system is described in terms of elements such as the general-purpose digital computers, sensors for the navigation subsystem, the guidance-system software, and the flight-control subsystem. Balloon-based and lidar wind soundings are used for operations assessment on the day of launch, and the guidance software is based on dedicated units for atmospheric powered flight, vacuum powered flight, and abort-specific situations. Optimization of the flight trajectories is discussed, and flight-control responses are illustrated for wavelengths of 500-6000 m. Alternate sensors are used for load relief, and adaptive GN&C systems based on alternate gain synthesis are used for systems failures.

  13. Does haptic steering guidance instigate speeding? A driving simulator study into causes and remedies.

    Science.gov (United States)

    Melman, T; de Winter, J C F; Abbink, D A

    2017-01-01

    An important issue in road traffic safety is that drivers show adverse behavioral adaptation (BA) to driver assistance systems. Haptic steering guidance is an upcoming assistance system which facilitates lane-keeping performance while keeping drivers in the loop, and which may be particularly prone to BA. Thus far, experiments on haptic steering guidance have measured driver performance while the vehicle speed was kept constant. The aim of the present driving simulator study was to examine whether haptic steering guidance causes BA in the form of speeding, and to evaluate two types of haptic steering guidance designed not to suffer from BA. Twenty-four participants drove a 1.8m wide car for 13.9km on a curved road, with cones demarcating a single 2.2m narrow lane. Participants completed four conditions in a counterbalanced design: no guidance (Manual), continuous haptic guidance (Cont), continuous guidance that linearly reduced feedback gains from full guidance at 125km/h towards manual control at 130km/h and above (ContRF), and haptic guidance provided only when the predicted lateral position was outside a lateral bandwidth (Band). Participants were familiarized with each condition prior to the experimental runs and were instructed to drive as they normally would while minimizing the number of cone hits. Compared to Manual, the Cont condition yielded a significantly higher driving speed (on average by 7km/h), whereas ContRF and Band did not. All three guidance conditions yielded better lane-keeping performance than Manual, whereas Cont and ContRF yielded lower self-reported workload than Manual. In conclusion, continuous steering guidance entices drivers to increase their speed, thereby diminishing its potential safety benefits. It is possible to prevent BA while retaining safety benefits by making a design adjustment either in lateral (Band) or in longitudinal (ContRF) direction. Copyright © 2016. Published by Elsevier Ltd.

  14. Space shuttle GN and C equation document: Entry and transition guidance

    Science.gov (United States)

    Marcus, F. J.

    1973-01-01

    The entry-guidance routine presented is designed to take the orbiter vehicle from entry interface through the critical heating phase of entry down to the start of the approach phase. The material includes: (1) a functional flow diagram, (2) input and output variables, (3) a description of equations, and (4) detailed flow diagrams.

  15. Carrier-phase differential GPS for automatic control of land vehicles

    Science.gov (United States)

    O'Connor, Michael Lee

    Real-time centimeter-level navigation has countless potential applications in land vehicles, including precise topographic field mapping, runway snowplowing in bad weather, and land mine detection and avoidance. Perhaps the most obvious and immediate need for accurate, robust land vehicle sensing is in the guidance and control of agricultural vehicles. Accurate guidance and automatic control of farm vehicles offers many potential advantages; however, previous attempts to automate these vehicles have been unsuccessful due to sensor limitations. With the recent development of real-time carrier-phase differential GPS (CDGPS), a single inexpensive GPS receiver can measure a vehicle's position to within a few centimeters and orientation to fractions of a degree. This ability to provide accurate real-time measurements of multiple vehicle states makes CDGPS ideal for automatic control of vehicles. This work describes the theoretical and experimental work behind the first successfully demonstrated automatic control system for land vehicles based on CDGPS. An extension of pseudolite-based CDGPS initialization methods was explored for land vehicles and demonstrated experimentally. Original land vehicle dynamic models were developed and identified using this innovative sensor. After initial automatic control testing using a Yamaha Fleetmaster golf cart, a centimeter-level, fully autonomous row guidance capability was demonstrated on a John Deere 7800 farm tractor.

  16. Guidance for evidence-informed policies about health systems: rationale for and challenges of guidance development.

    Science.gov (United States)

    Bosch-Capblanch, Xavier; Lavis, John N; Lewin, Simon; Atun, Rifat; Røttingen, John-Arne; Dröschel, Daniel; Beck, Lise; Abalos, Edgardo; El-Jardali, Fadi; Gilson, Lucy; Oliver, Sandy; Wyss, Kaspar; Tugwell, Peter; Kulier, Regina; Pang, Tikki; Haines, Andy

    2012-01-01

    In the first paper in a three-part series on health systems guidance, Xavier Bosch-Capblanch and colleagues examine how guidance is currently formulated in low- and middle-income countries, and the challenges to developing such guidance.

  17. 78 FR 56752 - Interim Staff Guidance Specific Environmental Guidance for Integral Pressurized Water Reactors...

    Science.gov (United States)

    2013-09-13

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Interim Staff Guidance Specific Environmental Guidance for Integral Pressurized Water Reactors... and operate integral pressurized water reactors (iPWR). This guidance applies to environmental reviews...

  18. Co-Optimization of Blunt Body Shapes for Moving Vehicles

    Science.gov (United States)

    Brown, James L. (Inventor); Garcia, Joseph A (Inventor); Kinney, David J. (Inventor); Bowles, Jeffrey V (Inventor); Mansour, Nagi N (Inventor)

    2014-01-01

    A method and associated system for multi-disciplinary optimization of various parameters associated with a space vehicle that experiences aerocapture and atmospheric entry in a specified atmosphere. In one embodiment, simultaneous maximization of a ratio of landed payload to vehicle atmospheric entry mass, maximization of fluid flow distance before flow separation from vehicle, and minimization of heat transfer to the vehicle are performed with respect to vehicle surface geometric parameters, and aerostructure and aerothermal vehicle response for the vehicle moving along a specified trajectory. A Pareto Optimal set of superior performance parameters is identified.

  19. Improved video guidance sensor for automated docking

    Science.gov (United States)

    Howard, Richard T.; Book, Michael L.

    1995-06-01

    The Video Guidance Sensor (VGS) has been developed by NASA's Marshall Space Flight Center (MSFC) to provide the capability for a spacecraft to find and track a target vehicle and determine the relative positions and attitudes between the sensor and the target. The sensor uses laser diodes to illuminate the target, a CCD-based camera to sense the target, and a frame-grabber and processor to convert the video information into relative range, azimuth, elevation, roll, pitch, and yaw. The sensor was first built in 1988 and used in successful automated docking experiments using the air-bearing spacecraft simulator in MSFC's Flight Robotics Laboratory. Since then, many changes and improvements have been made, based on the results of testing. In addition to the use of this system for space vehicles, it has been adapted for commercial application. The current design is being built as a prototype to prepare for flight testing on the Space Shuttle. Some of the changes from the original system were designed to improve the noise rejection of the system. Other changes were made to improve the overall range of operation of the system, and still other changes improved the bandwidth of the system. The current VGS is designed to operate from 110 meters down to 0.5 meters and output the relative position and attitude data at 5 Hz. The system will be able to operate under any orbital lighting conditions from full solar illumination to complete darkness. The VGS is also designed to be used with more than one target and sensor to allow for redundant configurations. This new prototype should be completed and undergoing open- and closed-loop testing after March 1995.

  20. An approximate atmospheric guidance law for aeroassisted plane change maneuvers

    Science.gov (United States)

    Speyer, Jason L.; Crues, Edwin Z.

    1988-01-01

    An approximate optimal guidance law for the aeroassisted plane change problem is presented which is based upon an expansion of the Hamilton-Jacobi-Bellman equation with respect to the small parameter of Breakwell et al. (1985). The present law maximizes the final velocity of the reentry vehicle while meeting terminal constraints on altitude, flight path angle, and heading angle. The integrable zeroth-order solution found when the small parameter is set to zero corresponds to a solution of the problem where the aerodynamic forces dominate the inertial forces. Higher order solutions in the expansion are obtained from the solution of linear partial differential equations requiring only quadrature integration.

  1. Analysis of unmanned aerial vehicle navigation and height control system based on GPS

    Institute of Scientific and Technical Information of China (English)

    Jianjun Zhang; Hong Yuan

    2010-01-01

    According to the characteristic of global positioning system(GPS)reflection signals,a GPS delay mapping receiver system scheme is put forward,which not only satisfies the unmanned aerial vehicle(UAV)guidance localization but also realizes height measurement.A code delay algorithm is put forward,which processes the direct and land reflected signal and outputs the navigation data and specular point.The GPS terrain reflected echo signal mathematical equation is inferred.The reflecting signal area,when the GPS signal passes the land,is analyzed.The height survey model reflected land surface characteristic is established.A simulation system which carries guidance localization of the UAV and the height measuring control through the GPS direct signal and the land reflected signal is designed,taken the GPS satellite as the illumination source,the receiver is put on the UAV.Then the UAV guidance signal,the GPS reflection signal and receiver's parallel processing are realized.The parallel processing reduces UAV's payload and raises system's operating efficiency.The simulation results confirms the validity of the model and also provides the basis for the UAV's optimization design.

  2. Stochastically optimized monocular vision-based navigation and guidance

    Science.gov (United States)

    Watanabe, Yoko

    The objective of this thesis is to design a relative navigation and guidance law for unmanned aerial vehicles, or UAVs, for vision-based control applications. The autonomous operation of UAVs has progressively developed in recent years. In particular, vision-based navigation, guidance and control has been one of the most focused on research topics for the automation of UAVs. This is because in nature, birds and insects use vision as the exclusive sensor for object detection and navigation. Furthermore, it is efficient to use a vision sensor since it is compact, light-weight and low cost. Therefore, this thesis studies the monocular vision-based navigation and guidance of UAVs. Since 2-D vision-based measurements are nonlinear with respect to the 3-D relative states, an extended Kalman filter (EKF) is applied in the navigation system design. The EKF-based navigation system is integrated with a real-time image processing algorithm and is tested in simulations and flight tests. The first closed-loop vision-based formation flight between two UAVs has been achieved, and the results are shown in this thesis to verify the estimation performance of the EKF. In addition, vision-based 3-D terrain recovery was performed in simulations to present a navigation design which has the capability of estimating states of multiple objects. In this problem, the statistical z-test is applied to solve the correspondence problem of relating measurements and estimation states. As a practical example of vision-based control applications for UAVs, a vision-based obstacle avoidance problem is specially addressed in this thesis. A navigation and guidance system is designed for a UAV to achieve a mission of waypoint tracking while avoiding unforeseen stationary obstacles by using vision information. An EKF is applied to estimate each obstacles' position from the vision-based information. A collision criteria is established by using a collision-cone approach and a time-to-go criterion. A minimum

  3. Atmospheric guidance techniques and performance

    Science.gov (United States)

    Harpold, J. C.; Gavert, D. E.

    1982-01-01

    The Orbiter entry guidance system controls the Space Shuttle Orbiter from the initial atmospheric penetration point to the point at which an earth relative velocity of 2500 feet/second is reached. At the latter point, control of the Orbiter is transferred to the terminal area energy management system. The entry guidance system is based on the concept that the range to be flown during entry is a unique function of the drag deceleration profile flown throughout the entry. The range prediction during entry is based on analytic equations which are simple drag deceleration functions of earth relative velocity above Mach 10.5 and energy with respect to the earth below Mach 10.5. Flight through the entry corridor is accomplished by linking these simple drag deceleration functions together in series in order to define a drag deceleration reference profile. The results of the first three Space Shuttle missions have not only verified the entry guidance concept but have also demonstrated the stability of the guidance system.

  4. Abortion Information: A Guidance Viewpoint

    Science.gov (United States)

    Wolleat, Patricia L.

    1975-01-01

    A number of questions relating to providing abortion information to teenagers can be raised from legal, ethical and philosophical standpoints. The purpose of this article is to examine abortion information-giving from the perspective of counseling and guidance theory and practice. (Author)

  5. Teacher Guidance of Knowledge Construction

    Science.gov (United States)

    Schwarz, Baruch; Dreyfus, Tommy; Hadas, Nurit; Hershkowitz, Rina

    2004-01-01

    This paper focuses on how teachers guide construction of knowledge in classrooms. We suggest that guidance hinges on the kind of dialogue teachers choose to engage students in. We propose several classroom dialogue types relevant for the construction of knowledge and suggest that critical dialogue is particularly effective for knowledge…

  6. Guidance: Interim Municipal Settlement Policy

    Science.gov (United States)

    Interim guidance and fact sheets regarding settlements involving municipalities or municipal waste under Section 122 CERCLA as amended by SARA. Interim policy sets forth the criteria by which EPA generally determines whether to exercise enforcement discretion to pursue MSW generators and transporters as PRPs.

  7. DOE Waste Treatability Group Guidance

    Energy Technology Data Exchange (ETDEWEB)

    Kirkpatrick, T.D.

    1995-01-01

    This guidance presents a method and definitions for aggregating U.S. Department of Energy (DOE) waste into streams and treatability groups based on characteristic parameters that influence waste management technology needs. Adaptable to all DOE waste types (i.e., radioactive waste, hazardous waste, mixed waste, sanitary waste), the guidance establishes categories and definitions that reflect variations within the radiological, matrix (e.g., bulk physical/chemical form), and regulated contaminant characteristics of DOE waste. Beginning at the waste container level, the guidance presents a logical approach to implementing the characteristic parameter categories as part of the basis for defining waste streams and as the sole basis for assigning streams to treatability groups. Implementation of this guidance at each DOE site will facilitate the development of technically defined, site-specific waste stream data sets to support waste management planning and reporting activities. Consistent implementation at all of the sites will enable aggregation of the site-specific waste stream data sets into comparable national data sets to support these activities at a DOE complex-wide level.

  8. Interstitial guidance of cancer invasion.

    NARCIS (Netherlands)

    Gritsenko, P.G.; Ilina, O.; Friedl, P.H.

    2012-01-01

    Cancer cell invasion into healthy tissues develops preferentially along pre-existing tracks of least resistance, followed by secondary tissue remodelling and destruction. The tissue scaffolds supporting or preventing guidance of invasion vary in structure and molecular composition between organs. In

  9. Cooperative Guidance for Multimissile Salvo Attack

    Institute of Scientific and Technical Information of China (English)

    Zhao Shiyu; Zhou Rui

    2008-01-01

    Cooperative guidance problems of multiple missiles are considered in this article. A cooperative guidance scheme, where coordi-nation algorithms and local guidance laws are combined together, is proposed. This scheme actually builds up a hierarchical cooperative guidance architecture, which may provide a general solution to the multimissile cooperative guidance problems. In the case of salvo attacks which require missiles to hit the target simultaneously, both centralized and distributed coordination algorithms are derived based on the impact-time-control guidance (ITCG) law. Numerical simulations are performed to demonstrate the effectiveness of the proposed approaches.

  10. Design of Launch Vehicle Flight Control Systems Using Ascent Vehicle Stability Analysis Tool

    Science.gov (United States)

    Jang, Jiann-Woei; Alaniz, Abran; Hall, Robert; Bedossian, Nazareth; Hall, Charles; Jackson, Mark

    2011-01-01

    A launch vehicle represents a complicated flex-body structural environment for flight control system design. The Ascent-vehicle Stability Analysis Tool (ASAT) is developed to address the complicity in design and analysis of a launch vehicle. The design objective for the flight control system of a launch vehicle is to best follow guidance commands while robustly maintaining system stability. A constrained optimization approach takes the advantage of modern computational control techniques to simultaneously design multiple control systems in compliance with required design specs. "Tower Clearance" and "Load Relief" designs have been achieved for liftoff and max dynamic pressure flight regions, respectively, in the presence of large wind disturbances. The robustness of the flight control system designs has been verified in the frequency domain Monte Carlo analysis using ASAT.

  11. Trajectory shaping guidance law based on virtual angle with terminal constraints

    Institute of Scientific and Technical Information of China (English)

    Xijing Hu; Xuemei Huang

    2013-01-01

    A trajectory shaping guidance law based on virtual angle (TSGLBVA) is proposed for a re-entry vehicle with the con-straints of terminal impact angles and their time derivatives. In the view of differential properties of the maneuvering trajectory, a virtual angle and a virtual radius are defined. Also, the shaping trajectory of the vehicle is established by the polynomials of the virtual angle. Then, four optimized parameters are selected ac-cording to the theorem of parameters transformation presented in this paper. Final y, a convergent variant of the Nelder-Mead algo-rithm is adopted to obtain the reference trajectory, and a trajectory feedback tracking guidance law is designed. The simulation re-sults demonstrate that the TSGLBVA ensures the re-entry vehicle to impact a target precisely from a specified direction with smal terminal load factor command, as wel as to obtain a maximum or constrained terminal velocity according to various requirements.

  12. An Accurate and Robust Flexible Guidance System for Indoor Industrial Environments

    Directory of Open Access Journals (Sweden)

    David Herrero-Pérez

    2013-07-01

    Full Text Available This work presents the development of a flexible industrial guidance system used to guide Automated Guided Vehicles (AGVs in indoor industrial environments. Typically, wireless guidance systems are composed of path-tracking and localization methods linked to follow a certain route. This paper focuses on the localization approach that permits industrial vehicles to operate indoors with the grade of accuracy, repeatability and reliability required by industrial applications. A key point is that, apart from accuracy, the position estimates should be performed at a high sample rate in order to permit the path tracker to follow the route properly. Robustness of absolute positioning is also crucial in industrial applications. An Extended Kalman Filter (EKF is adopted to fuse the information provided by a laser navigation system and odometry. The effectiveness of the development is tested using a custom modified commercial industrial vehicle operating in an industrial setting.

  13. Application of numerical methods to extend capabilities for optimal rocket guidance: report on reentry guidance of shuttle orbiter

    Science.gov (United States)

    1972-01-01

    Analytical models are presented for optimal trajectories and reentry guidance of the space shuttle orbiter. Major emphasis is placed on the development of a "footprint', which refers to a set of reachable destination positions attainable by the shuttle at a specified terminal altitude. An unconstrained reentry footprint was calculated for a shuttle vehicle which enters the earth's atmosphere at 93 km initial altitude after a deboost from a near earth orbit. The method of computation is briefly described, and graphs are presented which illustrate the footprint and the variation of state and control variables along it. The effects of constraints and of variations in initial state upon the footprint are discussed.

  14. Sliding Mode Control of the X-33 Vehicle in Launch Mode

    Science.gov (United States)

    Shtessel, Yuri; Jackson, Mark; Hall, Charles; Krupp, Don; Hendrix, N. Douglas

    1998-01-01

    The "nested" structure of the control system for the X33 vehicle in launch mode is developed. Employing backstopping concepts, the outer loop (guidance) and the Inner loop (rates) continuous sliding mode controllers are designed. Simulations of the 3-DOF model of the X33 launch vehicle showed an accurate, robust, de-coupled tracking performance.

  15. A Conceptual Framework for Design of Embedded Systems and Data Communication for Autonomous Vehicles

    DEFF Research Database (Denmark)

    Nielsen, Jens Frederik Dalsgaard; Bendtsen, Jan Dimon; Nielsen, Kirsten Mølgaard

    2005-01-01

    This paper describes a conceptual framework for the development of a hierarchal control architecture for an autonomous vehicle. The concept is based on time/frequency and safety analysis on board the vehicle. The time/frequency analysis is used to structure the guidance, navigation and control...

  16. Computer controlled vent and pressurization system. [of launch vehicle cryogenic propellant tanks

    Science.gov (United States)

    Cieslewicz, E. J.

    1975-01-01

    The paper illustrates how the Centaur space launch vehicle airborne computer, which was primarily used to perform guidance, navigation, and sequencing tasks, was further used to monitor and control inflight pressurization and venting of the cryogenic propellant tanks. Computer software flexibility also provided a failure detection and correction capability necessary to adopt and operate redundant hardware techniques and enhance the overall vehicle reliability.

  17. Vehicle Development Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Supports the development of prototype deployment platform vehicles for offboard countermeasure systems.DESCRIPTION: The Vehicle Development Laboratory is...

  18. Vehicle Development Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Supports the development of prototype deployment platform vehicles for offboard countermeasure systems. DESCRIPTION: The Vehicle Development Laboratory is...

  19. Career guidance and counselling for mobilities

    National Research Council Canada - National Science Library

    Zvariková, Mária

    2011-01-01

    In its first part, the article provides a basic overview on guidance and counselling for mobility issues at universities, focusing on the possibilities and role of guidance and counselling for both...

  20. Cooperative driving in an intelligent vehicle environment (CO-DRIVE)

    NARCIS (Netherlands)

    Vonk, T.; Arem, B. van; Hoedemaeker, D.M.

    2002-01-01

    The Co-Drive project is aimed at the development of an open, in-vehicle research and development ICT-platform for intelligent services. This paper focuses on two of these services: the safety interface with the driver (BIBI) and the dynamic travel guidance. BIBI is a Dutch acronym for Supremely Inte

  1. Spirit 2 vehicle: (A26.780). Post flight report

    Science.gov (United States)

    Chalfant, C. P.

    1992-05-01

    The Spirit 2 Launch Vehicle System was launched successfully from Poker Flat Research Range on 28 Mar. 1992. All flight objectives were achieved, and a peak altitude of 326 km was achieved. The vehicle liftoff weight was 20,092 pounds. The first stage, powered by the Talos motor, boosted the vehicle to an altitude of 6000 feet. The first stage experienced minor wind disturbances. The second stage, an Aries motor (a surplus solid propellant motor from the Minuteman 1 missile), performed as predicted. The inertial guidance system achieved the pre-programmed burnout conditions. The spent second stage impacted 157 km uprange.

  2. New-type of flying control for spinning TVC vehicle

    Institute of Scientific and Technical Information of China (English)

    LIU Xin-jian; YUAN Tian-bao

    2008-01-01

    A new kind of problem for TVC vehicle spinning in the boost stage had been researched.The study of non-linear flying dynamics modeling and dynamic properties of TVC vehicles reveal dominant coupled factors that affect the attitude stability and attitude precision of the pitch channel and yaw channel.The paper emphasizes the inertial delay coupled effects between vehicle's pitch servo svstem and yaw servo system,which have always been neglected.An uncoupled plan and control algorithm are put forward from the standpoint of engineering implementation to provide theoretical guidance and reference for further research on this complicated flying control.

  3. Quality Assurance in University Guidance Services

    Science.gov (United States)

    Simon, Alexandra

    2014-01-01

    In Europe there is no common quality assurance framework for the delivery of guidance in higher education. Using a case study approach in four university career guidance services in England, France and Spain, this article aims to study how quality is implemented in university career guidance services in terms of strategy, standards and models,…

  4. The Self in Guidance: Assumptions and Challenges.

    Science.gov (United States)

    Edwards, Richard; Payne, John

    1997-01-01

    Examines the assumptions of "self" made in the professional and managerial discourses of guidance. Suggests that these assumptions obstruct the capacity of guidance workers to explain their own practices. Drawing on contemporary debates over identity, modernity, and postmodernity, argues for a more explicit debate about the self in guidance. (RJM)

  5. 78 FR 53792 - Draft Guidance for Reciprocity

    Science.gov (United States)

    2013-08-30

    ...The U.S. Nuclear Regulatory Commission (NRC) is revising its licensing guidance for reciprocity. The NRC is requesting public comment on draft NUREG-1556, Volume 19, Revision 1, ``Consolidated Guidance about Materials Licenses: Guidance for Agreement State Licensees about NRC Form 241 `Report of Proposed Activities in Non- Agreement States, Areas of Exclusive Federal Jurisdiction, of Offshore......

  6. Providing Career Guidance for Young Women.

    Science.gov (United States)

    Colby, Pamela G.

    This module is directed at personnel working or planning to work in the areas of guidance, counseling, placement and follow-through in junior and senior high school settings, grades 7-12. The module topic is career guidance for young women of junior and senior high school age, aand the focus will be on providing nonbiased career guidance which…

  7. Quality Assurance in University Guidance Services

    Science.gov (United States)

    Simon, Alexandra

    2014-01-01

    In Europe there is no common quality assurance framework for the delivery of guidance in higher education. Using a case study approach in four university career guidance services in England, France and Spain, this article aims to study how quality is implemented in university career guidance services in terms of strategy, standards and models,…

  8. A Novel Low-cost, Ka-band, High Altitude, Multi-Baseline Unmanned Aerial Vehicle Sensor for Surface Water Ocean Topography Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The NRC Decadal Survey recommended the Surface Water Ocean Topography (SWOT) satellite mission to address terrestrial fresh water hydrology and physical oceanography...

  9. Reentry guidance for Space Shuttle

    Science.gov (United States)

    Causey, W.; Sohoni, V.

    1973-01-01

    An explicit guidance scheme is outlined which provides the appropriate energy management in order for the shuttle orbiter to reach any location within the required footprint. Considering the orbiter as entering the earth's atmosphere, expressions for the downrange, crossrange, and the time of the termination of the entry phase as functions of the control variables are developed. Performing an order-of-magnitude analysis of the terms in these expressions, only dominant terms are retained. Analytical expressions for the elements of the sensitivity matrix which represents the partial derivatives of the desired range with respect to control variables are formulated. Using the Gauss-Jordan inversion technique, the required change in guidance commands as a function of the deviations in the downrange and crossrange are explicitly computed.

  10. Reentry guidance for Space Shuttle

    Science.gov (United States)

    Causey, W.; Sohoni, V.

    1973-01-01

    An explicit guidance scheme is outlined which provides the appropriate energy management in order for the shuttle orbiter to reach any location within the required footprint. Considering the orbiter as entering the earth's atmosphere, expressions for the downrange, crossrange, and the time of the termination of the entry phase as functions of the control variables are developed. Performing an order-of-magnitude analysis of the terms in these expressions, only dominant terms are retained. Analytical expressions for the elements of the sensitivity matrix which represents the partial derivatives of the desired range with respect to control variables are formulated. Using the Gauss-Jordan inversion technique, the required change in guidance commands as a function of the deviations in the downrange and crossrange are explicitly computed.

  11. Review of soil contamination guidance

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, M.A.; Kennedy, W.E. Jr.; Soldat, J.K.

    1981-08-01

    A review of existing and proposed radioactive soil contamination standards and guidance was conducted for United Nuclear Corporation (UNC), Office of Surplus Facilities Management. Information was obtained from both government agencies and other sources during a literature survey. The more applicable standards were reviewed, evaluated, and summarized. Information pertaining to soil contamination for both facility operation and facility decommissioning was obtained from a variety of sources. These sources included: the Code of Federal Regulations, regulatory guides, the Federal Register, topical reports written by various government agencies, topical reports written by national laboratories, and publications from the American National Standards Institute (ANSI). It was difficult to directly compare the standards and guidance obtained from these sources since each was intended for a specific situation and different units or bases were used. However, most of the information reviewed was consistent with the philosophy of maintaining exposures at levels as low as reasonably achievable (ALARA).

  12. Microfluidic control of axonal guidance

    Science.gov (United States)

    Gu, Ling; Black, Bryan; Ordonez, Simon; Mondal, Argha; Jain, Ankur; Mohanty, Samarendra

    2014-10-01

    The precision of axonal pathfinding and the accurate formation of functional neural circuitry are crucial for an organism during development as well as during adult central and peripheral nerve regeneration. While chemical cues are believed to be primarily responsible for axonal pathfinding, we hypothesize that forces due to localized fluid flow may directly affect neuronal guidance during early organ development. Here, we report direct evidence of fluid flow influencing axonal migration, producing turning angles of up to 90°. Microfluidic flow simulations indicate that an axon may experience significant bending force due to cross-flow, which may contribute to the observed axonal turning. This method of flow-based guidance was successfully used to fasciculate one advancing axon onto another, showcasing the potential of this technique to be used for the formation of in vitro neuronal circuits.

  13. 2011 Army Strategic Planning Guidance

    Science.gov (United States)

    2011-03-25

    TESI ) of 22,000 Soldiers, the Army’s total force by the end of the mid-term period is programmed to be 520K (AC). We will achieve a more...dwell ratios, extending TESI authority to adequately man deploying units and sustain the All-Volunteer Force, right-sizing the generating force, and... TESI Temporary End-Strength Increase WMD Weapons of Mass Destruction 2011 ARMY STRATEGIC PLANNING GUIDANCE Page 19 2011

  14. Current materiality guidance for auditors

    OpenAIRE

    McKee, Thomas E.; Eilifsen, Aasmund

    2000-01-01

    Auditors have to make materiality judgments on every audit. This is a difficult process, as both quantitative and qualitative factors have to be evaluated. Additionally, there is no formal guidance for how to implement the materiality concepts discussed in the auditing standards. Although they are sometimes difficult to make, good materiality judgments are crucial for the conduct of a successful audit as poor judgments can result in an audit that is ineffective and/or inefficient. This report...

  15. Guidance for the Efficacy Evaluation of Products with Sporicidal Claims Against Clostridium difficile (June 2014)

    Science.gov (United States)

    This document provides an update to the Agency’s interim guidance for the efficacy evaluation of antimicrobial pesticides that are labeled for treating hard non-porous surfaces in healthcare settings contaminated with spores of Clostridium difficile.

  16. Proportional navigation law design of plane-symmetrical vehicle with terminal attack angle constraint for over target flight

    Science.gov (United States)

    Wu, Bin; Ji, Denggao; Guo, Zhenxi; Shen, Haibin; Zhang, Jianfei

    2016-11-01

    This article proposes a type of proportional navigation law design of plane-symmetrical vehicle with terminal attack angle constraint for over target flight. Firstly, the line of sight rotating rate and the velocity rotating rate model of the vehicle are expressed. Then, the attitude of the vehicle is constructed by the acceleration vector requirement of proportional navigation law. Accordingly, the guidance command uncertain issue can be avoided for plane-symmetrical vehicle over target flight. It guarantees high precision to hit the target. The effect and efficiency of the guidance law are shown by simulations of characteristic trajectories.

  17. Evaluation of connected vehicle impact on mobility and mode choice

    Directory of Open Access Journals (Sweden)

    Simon Minelli

    2015-10-01

    Full Text Available Connected vehicle is emerging as a solution to exacerbating congestion problems in urban areas. It is important to understand the impacts of connected vehicle on network and travel behavior of road users. The main objective of this paper is to evaluate the impact of connected vehicle on the mode choice and mobility of transportation networks. An iterative methodology was used in this paper where demands for various modes were modified based on the changes in travel time between each origin-destination (OD pair caused by introduction of connected vehicle. Then a traffic assignment was performed in a micro-simulation model, which was able to accurately simulate vehicle-to-vehicle communication. It is assumed that vehicles are equipped with a dynamic route guidance technology to choose their own route using real-time traffic information obtained through communication. The travel times obtained from the micro-simulation model were compared with a base scenario with no connected vehicle. The methodology was tested for a portion of Downtown Toronto, Ontario, Canada. In order to quantify changes in mode share with changes in travel time associated with each OD pair, mode choice models were developed for auto, transit, cycling and pedestrians using data mainly from the Transportation Tomorrow Survey. The impact of connected vehicle on mode choice was evaluated for different market penetrations of connected vehicle. The results of this study show that average travel times for the whole auto mode will generally increase, with the largest increase from connected vehicles. This causes an overall move away from the auto mode for high market penetrations if a dynamic route guidance algorithm is implemented.

  18. Survivability design for a hybrid underwater vehicle

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Biao; Wu, Chao; Li, Xiang; Zhao, Qingkai; Ge, Tong [State Key Lab of Ocean Engineering, School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2015-03-10

    A novel hybrid underwater robotic vehicle (HROV) capable of working to the full ocean depth has been developed. The battery powered vehicle operates in two modes: operate as an untethered autonomous vehicle in autonomous underwater vehicle (AUV) mode and operate under remote control connected to the surface vessel by a lightweight, fiber optic tether in remotely operated vehicle (ROV) mode. Considering the hazardous underwater environment at the limiting depth and the hybrid operating modes, survivability has been placed on an equal level with the other design attributes of the HROV since the beginning of the project. This paper reports the survivability design elements for the HROV including basic vehicle design of integrated navigation and integrated communication, emergency recovery strategy, distributed architecture, redundant bus, dual battery package, emergency jettison system and self-repairing control system.

  19. Guidance and Control of an Autonomous Soaring UAV

    Science.gov (United States)

    Allen, Michael J.; Lin, Victor

    2007-01-01

    Thermals caused by convection in the lower atmosphere are commonly used by birds and glider pilots to extend flight duration, increase cross-country speed, improve range, or simply to conserve energy. Uninhabited Aerial Vehicles (UAVs) can also increase performance and reduce energy consumption by exploiting atmospheric convection. An autonomous soaring research project was conducted at the NASA Dryden Flight Research Center to evaluate the concept through flight test of an electric-powered motorglider with a wingspan of 4.27 m (14 ft). The UAV's commercial autopilot software was modified to include outer-loop soaring guidance and control. The aircraft total energy state was used to detect and soar within thermals. Estimated thermal size and position were used to calculate guidance commands for soaring flight. Results from a total of 23 thermal encounters show good performance of the guidance and control algorithms to autonomously detect and exploit thermals. The UAV had an average climb of 172 m (567 ft) during these encounters.

  20. F-18 high alpha research vehicle surface pressures - Initial in-flight results and correlation with flow visualization and wind-tunnel data

    Science.gov (United States)

    Fisher, David F.; Banks, Daniel W.; Richwine, David M.

    1990-01-01

    Flight tests with the NASA F-18 high-alpha research vehicle (HARV) have yielded pressure distributions at angles of attack from 10 to 50 deg, at Mach 0.23 to 0.6, at five fuselage forebody stations and three on the leading-edge extensions (LEXs). Correlations are made between these data and both previously obtained HARV flow visualizations and wind tunnel model test results. The general trend is one in which the forebody's maximum suction pressure peaks increase in magnitude, after their first appearance at alpha of about 19 deg, with increasing alpha. LEX pressure-distribution trends involve the inward progression of the maximum suction peaks, an increase in the magnitude of the maximum pressure peaks up to pressure core breakdown, and the decrease and general flattening of the pressure distribution beyond the LEX primary vortex breakdown.

  1. Optimum PN Guidance Law for Maneuvering Target

    Institute of Scientific and Technical Information of China (English)

    SUN Bao-cai; QI Zai-kang

    2007-01-01

    An optimum PN guidance law for maneuvering target is developed using optimal control theory. By estimating the target position and setting the cost function, the guidance law can be deduced even without knowing the missile lateral acceleration. Since the quadratic cost function can make a compromise between the miss distance andthe control constraint, the optimum guidance law obtained is more general. Also, introduced line of sight rate as the input, a practical form of this guidance law is derived. The simulation results show the effectiveness of the guidance laws.

  2. Trajectory of a road vehicle during road maintenance

    Directory of Open Access Journals (Sweden)

    Stachová Darina

    2017-01-01

    Full Text Available Consider a vehicle moving on a road whose usage over time creates an uneven surface on the road. Road unevenness that we encounter on surface communications often arises as a consequence of dynamical effects of moving vehicles, of weather changes, and due to road construction works. This article concerns with mathematical modeling of the trajectory of a road vehicle moving on such a surface during the course of road maintenance.

  3. 49 CFR 177.843 - Contamination of vehicles.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Contamination of vehicles. 177.843 Section 177.843... and Unloading § 177.843 Contamination of vehicles. (a) Each motor vehicle used for transporting Class... surface contamination is not greater than the level prescribed in § 173.443(a) of this subchapter....

  4. ROLLING NOISE SIMULATION OF A RAILWAY VEHICLE

    Directory of Open Access Journals (Sweden)

    Traian MAZILU

    2013-05-01

    Full Text Available Rolling noise of the railway vehicles is occurred by the wheel/rail vibration excited bythe rolling surfaces roughness. This paper presents an acoustic model able to predict the rollingnoise level of a railway vehicle. The acoustic model is based on a wheel/rail vibration modelwhich takes into account the structural wheel vibration (Remington model and the bendingvertical waves of the rail. To this, the track model with an infinite Euler Bernoulli beam elasticallysupported on two layers is applied to simulate the effect of the ballasted track. The influence of therolling surfaces roughness and vehicle velocity on the rolling noise is investigated.

  5. Static and dynamic stability of the guidance force in a side-suspended HTS maglev system

    Science.gov (United States)

    Zhou, Dajin; Cui, Chenyu; Zhao, Lifeng; Zhang, Yong; Wang, Xiqing; Zhao, Yong

    2017-02-01

    The static and dynamic stability of the guidance force in a side-suspended HTS-PMG (permanent magnetic guideway) system were studied theoretically and experimentally. It is found that there are two types of guidance force that exist in the HTS-PMG system, which are sensitive to the levitation gap and the arrangement of YBCO bulks around the central axis of the PMG. An optimized YBCO array was used to stabilize the system, which enabled a side-suspended HTS-PMG maglev vehicle to run stably at 102 km h-1 on a circular test track with 6.5 m in diameter.

  6. A cislunar guidance methodology and model for low thrust trajectory generation

    Science.gov (United States)

    Korsmeyer, David J.

    1992-01-01

    A guidance methodology for generating low-thrust cislunar trajectories was developed and incorporated in a computer model. The guidance methodology divides the cislunar transfer into three phases. Each phase is discussed in turn. To establish the effectiveness of the methodology and algorithms the computer model generated three example cases for the cislunar transfer of a low-thrust electric orbital transfer vehicle (EOTV). Transfers from both earth orbit to lunar orbit and from lunar orbit back to earth orbit are considered. The model allows the determination of the low-thrust EOTV's time-of-flight, propellant mass, payload mass, and thrusting history.

  7. A Novel Low-cost, Ka-band, High Altitude, Multi-Baseline Unmanned Aerial Vehicle Sensor for Surface Water Ocean Topography Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal presents the Ka-band SWOT Phenomenology Airborne Radar (KaSPAR) to support the surface water ocean topography (SWOT) mission for science and algorithm...

  8. 钛表面微沟槽形貌对人牙龈成纤维细胞接触诱导效应的比较研究%Comparative study on contact guidance activity of human gingival fibroblasts on microgroove surfaces

    Institute of Scientific and Technical Information of China (English)

    赖颖真; 陈江

    2015-01-01

    Objective To compared the difference incontact guidance activity among microgroove surfaces with different sizes of human gingival fibroblast(HGF),with the hope of providing basis for size selection of microgroove for transmucosal part of dental implant.Methods Basing on the size of HGF,microgroove titanium surfaces were fabricated by photolithography with parallel grooves:15,30 or 60 μm in width and 5 or 10 μm in depth.The groups that used different microgroove surfaces were denoted as T15/5,T15/10,T30/5,T30/10,T60/5,and T60/10.Group T0(the control meanwhile was a sputter of titanium on a simple planar silicon substrate).The morphology that HGF arranged along the groove was analyzed by immunofluorescence staining.Difference in contact guidance activity was quantitatively compared basing on the consistency of nucleus arrangement and deformation ratio.Results Microgroove groups had significantly higher consistency of nucleus arrangement and deformation ratio compared to the control group,with T60/10 had the highest consistency of 0.937±0.024,and T15/5 had the lowest consistency of 0.660± 0.016 and T60/10 had the highest deformation ratio of 3.555±0.205,and T15/5 had the lowest deformation ratio of 1.819±0.011.Conclusions Microgroove surfaces of all the different sizes show contact guidance activity on HGF,and the contact guidance activity increases with the increase of width and depth.%目的 比较钛表面不同尺寸微沟槽对人牙龈成纤维细胞(human gingival fibroblast,HGF)接触诱导效应的差异,以期为种植体穿龈部分微沟槽尺寸设计提供依据.方法设计微沟槽宽度与间距相等,利用光刻技术在硅片表面制作宽度分别为15、30、60 μm,深度分别为5和10 μm的微沟槽,分别命名为T15/5、T15/10、T30/5 、T30/10、T60/5、T60/10组,各组硅片表面溅射钛;以溅射钛的硅片为对照组(每组样本量为7).免疫荧光观察细胞沿沟槽排列的形态,通过细胞核排列一致性比例及

  9. QT interval variability in body surface ECG : measurement, physiological basis, and clinical value: position statement and consensus guidance endorsed by the European Heart Rhythm Association jointly with the ESC Working Group on Cardiac Cellular Electrophysiology

    NARCIS (Netherlands)

    Baumert, Mathias; Porta, Alberto; Vos, Marc A; Malik, Marek; Couderc, Jean-Philippe; Laguna, Pablo; Piccirillo, Gianfranco; Smith, Godfrey L; Tereshchenko, Larisa G; Volders, Paul G A

    2016-01-01

    This consensus guideline discusses the electrocardiographic phenomenon of beat-to-beat QT interval variability (QTV) on surface electrocardiograms. The text covers measurement principles, physiological basis, and clinical value of QTV. Technical considerations include QT interval measurement and the

  10. Precision optical navigation guidance system

    Science.gov (United States)

    Starodubov, D.; McCormick, K.; Nolan, P.; Johnson, D.; Dellosa, M.; Volfson, L.; Fallahpour, A.; Willner, A.

    2016-05-01

    We present the new precision optical navigation guidance system approach that provides continuous, high quality range and bearing data to fixed wing aircraft during landing approach to an aircraft carrier. The system uses infrared optical communications to measure range between ship and aircraft with accuracy and precision better than 1 meter at ranges more than 7.5 km. The innovative receiver design measures bearing from aircraft to ship with accuracy and precision better than 0.5 mRad. The system provides real-time range and bearing updates to multiple aircraft at rates up to several kHz, and duplex data transmission between ship and aircraft.

  11. Quality guidance and quality formation

    DEFF Research Database (Denmark)

    Poulsen, Carsten Stig; Juhl, Hans Jørn; Kristensen, Kai

    1996-01-01

    This paper presents an extension of the quality guidance model of Steenkamp and van Trijp that includes consumer quality formation processes. Quality expectations and quality experiences are seen as antecedents of perceived overall product quality conceptual model is applied using LISREL to a data...... set on Danish butter cookies. Five plausible models of the relation between expectation, experience and perceived product quality are estimated. Finally one model is selected on the basis of three criteria: chi-square, RMSEA and AIC: The results show a model where expectations are indirectly related...... to perceived quality through experience. Udgivelsesdato: APR...

  12. Quality guidance and quality formation

    DEFF Research Database (Denmark)

    Poulsen, Carsten Stig; Juhl, Hans Jørn; Kristensen, Kai

    1996-01-01

    This paper presents an extension of the quality guidance model of Steenkamp and van Trijp that includes consumer quality formation processes. Quality expectations and quality experiences are seen as antecedents of perceived overall product quality conceptual model is applied using LISREL to a data...... set on Danish butter cookies. Five plausible models of the relation between expectation, experience and perceived product quality are estimated. Finally one model is selected on the basis of three criteria: chi-square, RMSEA and AIC: The results show a model where expectations are indirectly related...... to perceived quality through experience. Udgivelsesdato: APR...

  13. Orthobiologic Interventions Using Ultrasound Guidance.

    Science.gov (United States)

    Malanga, Gerard; Abdelshahed, Dena; Jayaram, Prathap

    2016-08-01

    The application of regenerative therapies for the treatment of musculoskeletal conditions has emerged over the last decade with recent acceleration. These include prolotherapy, platelet-rich plasma, and mesenchymal stem cell therapy. These strategies augment the body's innate physiology to heal pathologic processes. This article presents an overview of platelet-rich plasma and mesenchymal stem cell therapy for the treatment of musculoskeletal injuries. A brief literature review is included, as are techniques for the use of ultrasound guidance to assist with these procedures. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Infrared characterization and detection of free surface wave wake of underwater vehicle%水下航行体自由表面波浪尾迹红外特征及探测

    Institute of Scientific and Technical Information of China (English)

    张士成; 杨桢; 杨立; 缪涛

    2012-01-01

    A special wave pattern will be formed on the sea surface when the underwater vehicle cruises under water and it can be used for infrared detection of submarines. Based on potential flow theory and the "panel" method, the wave wake on the sea surface of underwater vehicle was simulated. Considering the factors of sea environment, the ray tracing algorithm was applied to build the surface wake infrared imaging model. Then the infrared imaging characterization of free surface wake under different detection azimuths with a variety of speeds and submerged depths was proposed. Results show that the wake infrared characterization is mainly small transverse wave patterns under low speed, while it is more obvious longitudinal wave patterns under high speed; the special wave wake on the sea surface can be effectively avoided by controlling the speeds and submerged depths of underwater vehicle during the voyage; the wake characterization is easier to be detected as detection azimuth in the heading direction; the use of infrared characterization of free surface wake for detecting submarines is mainly suitable for submarines under high speeds or snorkel navigational status and other low submerged depths situations. The results are of guiding significance for infrared detection of submarines and submarines' hidden voyage.%水下航行体在航行过程中,会在海面形成特性波纹尾迹,可利用这种尾迹实现红外探潜.根据势流理论和“面元”法,模拟了水下航行体在海面上产生的波浪尾迹,采用射线跟踪算法建立了表面尾迹的红外成像模型,综合考虑海面环境因素的影响,研究了多种航速和潜深下自由表面尾迹不同探测方位角的红外成像特征.结果表明:低航速下尾迹红外特征主要表现为波形较小的横波特征,高航速下尾迹表现为较为明显的纵波特征;在航行过程中,可通过控制航速和潜深来有效规避海面特性波纹的产生;探测方位位于航行

  15. Navigation simulator for the Space Tug vehicle

    Science.gov (United States)

    Colburn, B. K.; Boland, J. S., III; Peters, E. G.

    1977-01-01

    A general simulation program (GSP) for state estimation of a nonlinear space vehicle flight navigation system is developed and used as a basis for evaluating the performance of a Space Tug navigation system. An explanation of the iterative guidance mode (IGM) guidance law, derivation of the dynamics, coordinate frames and state estimation routines are given in order to clarify the assumptions and approximations made. A number of simulation and analytical studies are used to demonstrate the operation of the Tug system. Included in the simulation studies are (1) initial offset vector parameter study; (2) propagation time vs accuracy; (3) measurement noise parametric study and (4) reduction in computational burden of an on-board implementable scheme. From the results of these studies, conclusions and recommendations concerning future areas of practical and theoretical work are presented.

  16. Video Guidance Sensor and Time-of-Flight Rangefinder

    Science.gov (United States)

    Bryan, Thomas; Howard, Richard; Bell, Joseph L.; Roe, Fred D.; Book, Michael L.

    2007-01-01

    A proposed video guidance sensor (VGS) would be based mostly on the hardware and software of a prior Advanced VGS (AVGS), with some additions to enable it to function as a time-of-flight rangefinder (in contradistinction to a triangulation or image-processing rangefinder). It would typically be used at distances of the order of 2 or 3 kilometers, where a typical target would appear in a video image as a single blob, making it possible to extract the direction to the target (but not the orientation of the target or the distance to the target) from a video image of light reflected from the target. As described in several previous NASA Tech Briefs articles, an AVGS system is an optoelectronic system that provides guidance for automated docking of two vehicles. In the original application, the two vehicles are spacecraft, but the basic principles of design and operation of the system are applicable to aircraft, robots, objects maneuvered by cranes, or other objects that may be required to be aligned and brought together automatically or under remote control. In a prior AVGS system of the type upon which the now-proposed VGS is largely based, the tracked vehicle is equipped with one or more passive targets that reflect light from one or more continuous-wave laser diode(s) on the tracking vehicle, a video camera on the tracking vehicle acquires images of the targets in the reflected laser light, the video images are digitized, and the image data are processed to obtain the direction to the target. The design concept of the proposed VGS does not call for any memory or processor hardware beyond that already present in the prior AVGS, but does call for some additional hardware and some additional software. It also calls for assignment of some additional tasks to two subsystems that are parts of the prior VGS: a field-programmable gate array (FPGA) that generates timing and control signals, and a digital signal processor (DSP) that processes the digitized video images. The

  17. Design of Second-Order Sliding Mode Guidance Law Based on the Nonhomogeneous Disturbance Observer

    Directory of Open Access Journals (Sweden)

    Huibo Zhou

    2014-01-01

    Full Text Available Considering the guidance problem of relative motion of missile target without the dynamic characteristics of missile autopilot in the interception planar, non-homogeneous disturbance observer is applied for finite-time estimation with respect to the target maneuvering affecting the guidance performance. Two guidance laws with finite-time convergence are designed by using a fast power rate reaching law and the prescribed sliding variable dynamics. The nonsingular terminal sliding mode surface is selected to improve dynamic characteristics of missile autopilot. Furthermore, the finite-time guidance law with dynamic delay characteristics is designed for the target maneuvering through adopting variable structure dynamic compensation. The simulation results demonstrate that, for different target maneuvering, the proposed guidance laws can restrain the sliding mode chattering problem effectively and make the missile hit the maneuvering target quickly and accurately with condition of corresponding assumptions.

  18. Bottom-following control for an underactuated unmanned undersea vehicle using integral-terminal sliding mode control

    Institute of Scientific and Technical Information of China (English)

    严浙平; 于浩淼; 李本银

    2015-01-01

    The bottom-following problem of an underactuated unmanned undersea vehicle (UUV) is addressed. A robust nonlinear controller is developed by using integral-terminal sliding mode control (ITSMC), which can exponentially drive an UUV onto a predefined path at a constant forward speed. The kinematic error equations are first derived in the Serret-Frenet frame. Using the line of sight (LOS) method, Lyapunov’s direct technique and tracking differentiator, the guidance law is established. Then, the kinematic controller, the guidance law, is expanded to cope with vehicle dynamics by resorting to introduce two integral-terminal sliding surfaces. Robustness to parameter perturbation is addressed by incorporating the reaching laws associated with the upper bound of the parameter perturbation. The proposed control law can guarantee that all error signals globally exponentially converge to the origin. Finally, a series of numerical simulation results are presented and discussed. In these simulations, wave, constant unknown ocean currents (for the purposes of the controller) and the parameter perturbation are added to illustrate the robustness and effectiveness of the bottom-following control scheme.

  19. Bottom-following control for an underactuated unmanned undersea vehicle using integral-terminal sliding mode control

    Institute of Scientific and Technical Information of China (English)

    严浙平; 于浩淼; 李本银

    2015-01-01

    The bottom-following problem of an underactuated unmanned undersea vehicle(UUV) is addressed. A robust nonlinear controller is developed by using integral-terminal sliding mode control(ITSMC), which can exponentially drive an UUV onto a predefined path at a constant forward speed. The kinematic error equations are first derived in the Serret-Frenet frame. Using the line of sight(LOS) method, Lyapunov’s direct technique and tracking differentiator, the guidance law is established. Then, the kinematic controller, the guidance law, is expanded to cope with vehicle dynamics by resorting to introduce two integral-terminal sliding surfaces. Robustness to parameter perturbation is addressed by incorporating the reaching laws associated with the upper bound of the parameter perturbation. The proposed control law can guarantee that all error signals globally exponentially converge to the origin. Finally, a series of numerical simulation results are presented and discussed. In these simulations, wave, constant unknown ocean currents(for the purposes of the controller) and the parameter perturbation are added to illustrate the robustness and effectiveness of the bottom-following control scheme.

  20. Flight Guidance System Requirements Specification

    Science.gov (United States)

    Miller, Steven P.; Tribble, Alan C.; Carlson, Timothy M.; Danielson, Eric J.

    2003-01-01

    This report describes a requirements specification written in the RSML-e language for the mode logic of a Flight Guidance System of a typical regional jet aircraft. This model was created as one of the first steps in a five-year project sponsored by the NASA Langley Research Center, Rockwell Collins Inc., and the Critical Systems Research Group of the University of Minnesota to develop new methods and tools to improve the safety of avionics designs. This model will be used to demonstrate the application of a variety of methods and techniques, including safety analysis of system and subsystem requirements, verification of key properties using theorem provers and model checkers, identification of potential sources mode confusion in system designs, partitioning of applications based on the criticality of system hazards, and autogeneration of avionics quality code. While this model is representative of the mode logic of a typical regional jet aircraft, it does not describe an actual or planned product. Several aspects of a full Flight Guidance System, such as recovery from failed sensors, have been omitted, and no claims are made regarding the accuracy or completeness of this specification.

  1. Optimal terminal guidance for exoatmospheric interception

    Directory of Open Access Journals (Sweden)

    Yu Wenbin

    2016-08-01

    Full Text Available In this study, two optimal terminal guidance (OTG laws, one of which takes into account the final velocity vector constraint, are developed for exoatmospheric interception using optimal control theory. In exoatmospheric interception, because the proposed guidance laws give full consideration to the effect of gravity, they consume much less fuel than the traditional guidance laws while requiring a light computational load. In the development of the guidance laws, a unified optimal guidance problem is put forward, where the final velocity vector constraint can be considered or neglected by properly adjusting a parameter in the cost function. To make this problem analytically solvable, a linear model is used to approximate the gravity difference, the difference of the gravitational accelerations of the target and interceptor. Additionally, an example is provided to show that some achievements of this study can be used to significantly improve the fuel efficiency of the pulsed guidance employed by the interceptor whose divert thrust level is fixed.

  2. Optimal terminal guidance for exoatmospheric interception

    Institute of Scientific and Technical Information of China (English)

    Yu Wenbin; Chen Wanchun; Yang Liang; Liu Xiaoming; Zhou Hao

    2016-01-01

    In this study, two optimal terminal guidance (OTG) laws, one of which takes into account the final velocity vector constraint, are developed for exoatmospheric interception using optimal control theory. In exoatmospheric interception, because the proposed guidance laws give full consideration to the effect of gravity, they consume much less fuel than the traditional guidance laws while requiring a light computational load. In the development of the guidance laws, a unified optimal guidance problem is put forward, where the final velocity vector constraint can be consid-ered or neglected by properly adjusting a parameter in the cost function. To make this problem ana-lytically solvable, a linear model is used to approximate the gravity difference, the difference of the gravitational accelerations of the target and interceptor. Additionally, an example is provided to show that some achievements of this study can be used to significantly improve the fuel efficiency of the pulsed guidance employed by the interceptor whose divert thrust level is fixed.

  3. In-Vehicle GPS/DR Navigation System Development and Test Results in Singapore

    Institute of Scientific and Technical Information of China (English)

    Xu Ai-gong; Ling Keck-voon; C. L. Law; Yang Dong-kai

    2003-01-01

    This paper introduces the in-car navigation system prototype development and test results under the context of Singapore. In the system, integrated GPS/DR is used for continuous vehicle positioning. A digital road network map database is built for the whole Singapore. The database is designed to support map matching, route determination, and route guidance functions. The prototype system demonstrates GPS positioning of the vehicle in real-time, tracking the vehicle onto a digital map with fix updates every one or two seconds.With the map matched vehicle location on the map, voice and/or text guidance is provide to the driver. The vehicle position can also be transferred to control centre through communication data link for the purpose of fleet management.

  4. International governmental agencies and career guidance

    OpenAIRE

    Conger, Stuart

    1999-01-01

    The international Organization for Economic Cooperation and Development (OECD), like many national and international organizations concerned with economic development believes that career guidance has an important role in promoting the development of a country's human resources. (Mapping the future: Young People and career guidance OECD, 1996). Generally the economic development agencies always recommend that career guidance services should be strengthened. Too frequently, however, they do no...

  5. Hybrid Guidance System for Relative Navigation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Future NASA architectures and missions will involve many distributed platforms that must work together. This in turn requires guidance, navigation and control...

  6. Lunar landing and launch facilities (Complex 39L): Guidance systems and propellant systems

    Science.gov (United States)

    1989-01-01

    After a general, overall definition of Complex 39L during the previous two years, the 1988-89 projects were chosen to focus on more specific aspects, specifically, guidance systems and propellant systems. Six teams or subtasks were formulated: cascade refrigeration for boil-off recovery of cryogenic storage vessels; lunar ground-based radar system to track space vehicles; microwave altimeter for spacecraft; development of a computational model for the determination of lunar surface and sub-surface temperatures; lunar cryogenic facility for the storage of fuels; and lunar lander fuel inventory tent for the storage of cryogenic vessels. At the present time, a cascade refrigeration system for a cryogenic boil-off recovery system has been designed. This is to serve as a baseline system. The ground-based tracking system uses existing technology to implement a reliable tracking radar for use on the lunar surface. A prototype has been constructed. The microwave altimeter is for use on lunar landers. It makes use of the Doppler effect to measure both altitude and the vertical velocity component of the spacecraft. A prototype has been constructed. A computational model that predicts the spatial and temporal temperature profiles of the lunar subsurface was formulated. Propellant storage vessels have been designed. A support for these vessels which minimizes heat leaks was also designed. Further work on the details of the Fuel Inventory Tent (FIT) was performed. While much design work on the overall Complex 39L remains to be done, significant new work has been performed in the subject areas.

  7. Aerocapture guidance and navigation for the Rosetta Comet Nucleus Sample Return Mission

    Science.gov (United States)

    Serrano-Martinez, J. B.; Hechler, M.

    The aerocapture/reentry phase of the Comet Nucleus Sample Return Mission Rosetta when returning from the Comet back to earth is discussed. The guidance and navigation process for a guided atmospheric entry to ground from an entry velocity of over 15 km/s has been simulated and the feasibility of such an entry at an entry angle of -10.5 deg, using an Apollo shape vehicle and guidance methods similar to those used for Apollo and the Shuttle Orbiter, has been demonstrated. Landing precision of less than 10 km at accelerations below 20 g can be reached. Critical areas of system design like the center of gravity location of the entry vehicle are addressed.

  8. NASA Human Integration Design Handbook (HIDH): Revitalization of Space-Related Human Factors, Environmental, and Habitability Data and Design Guidance

    Science.gov (United States)

    Stroud, Kenneth; Pickett, Lynn; Tillman, Barry

    2008-01-01

    This poster presentation reviews the Human Integration Design Handbook (HIDH). It provides guidance and data to aid vehicle / habitat designers in human-system integration It also aids requirements writers in development of human-system integration requirements from SFHSS Standards

  9. Cooperative path planning of unmanned aerial vehicles

    CERN Document Server

    Tsourdos, Antonios; Shanmugavel, Madhavan

    2010-01-01

    An invaluable addition to the literature on UAV guidance and cooperative control, Cooperative Path Planning of Unmanned Aerial Vehicles is a dedicated, practical guide to computational path planning for UAVs. One of the key issues facing future development of UAVs is path planning: it is vital that swarm UAVs/ MAVs can cooperate together in a coordinated manner, obeying a pre-planned course but able to react to their environment by communicating and cooperating. An optimized path is necessary in order to ensure a UAV completes its mission efficiently, safely, and successfully.

  10. Guidance Law and Neural Control for Hypersonic Missile to Track Targets

    Directory of Open Access Journals (Sweden)

    Wenxing Fu

    2016-01-01

    Full Text Available Hypersonic technology plays an important role in prompt global strike. Because the flight dynamics of a hypersonic vehicle is nonlinear, uncertain, and highly coupled, the controller design is challenging, especially to design its guidance and control law during the attack of a maneuvering target. In this paper, the sliding mode control (SMC method is used to develop the guidance law from which the desired flight path angle is derived. With the desired information as control command, the adaptive neural control in discrete time is investigated ingeniously for the longitudinal dynamics of the hypersonic missile. The proposed guidance and control laws are validated by simulation of a hypersonic missile against a maneuvering target. It is demonstrated that the scheme has good robustness and high accuracy to attack a maneuvering target in the presence of external disturbance and missile model uncertainty.

  11. Effect of lateral deformations of guideway on guidance characteristics of maglev train

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ki Jung; Yang, Seok Jo [Dept. of Mechatronics Engineering, Chungnam National Unversity, Daejeon (Korea, Republic of); Lee, Jae Kyoung; Han, Hyung Suk [Korea Institute of Machery and Materials, Daejeon (Korea, Republic of)

    2015-11-15

    A slender guideway is essential in improving aesthetically and reducing its construction cost which accounts for about 70% of overall investment for maglev system. As the slender guideway, however, may increase its deformation, its effect on levitation stability and guidance performance needs to be analyzed. The purpose of this study is to analyze the effect on guidance characteristics of maglev due to the lateral deformation of the guideway girder and lateral irregularity of guiderail. For doing this, 3D model considering lateral deformation of girder and irregularity of rail of the guideway is developed. Using the dynamic interaction model integrated with the proposed guideway and maglev vehicle including electromagnetics and its controller, guidance characteristics of maglev are analyzed. It is analyzed that the effect on lateral deformation of girder is relatively small compared to deformation on the lateral irregularities of guiderail.

  12. Electric Vehicle Charging Modeling

    OpenAIRE

    Grahn, Pia

    2014-01-01

    With an electrified passenger transportation fleet, carbon dioxide emissions could be reduced significantly depending on the electric power production mix. Increased electric power consumption due to electric vehicle charging demands of electric vehicle fleets may be met by increased amount of renewable power production in the electrical systems. With electric vehicle fleets in the transportation system there is a need for establishing an electric vehicle charging infrastructure that distribu...

  13. Guidance of an autonomous planetary rover based on a short-range hazard detection system

    Science.gov (United States)

    Yerazunis, S. W.; Frederick, D. K.; Hunter, E.; Troiani, N.

    1979-01-01

    The guidance of an autonomous planetary roving vehicle using a scanning laser/multidetector terrain sensor for short-range hazard detection has been simulated. The sensor data are used to model the terrain, thereby providing the information required by a path selection algorithm to control the motion of the rover. These simulation studies are providing the basis for developing both the real-time computer control software and the hardware systems for laboratory and field testing of rover.

  14. Electric Vehicle Technician

    Science.gov (United States)

    Moore, Pam

    2011-01-01

    With President Obama's goal to have one million electric vehicles (EV) on the road by 2015, the electric vehicle technician should have a promising and busy future. "The job force in the car industry is ramping up for a revitalized green car industry," according to Greencareersguide.com. An electric vehicle technician will safely troubleshoot and…

  15. Electric vehicles: Driving range

    Science.gov (United States)

    Kempton, Willett

    2016-09-01

    For uptake of electric vehicles to increase, consumers' driving-range needs must be fulfilled. Analysis of the driving patterns of personal vehicles in the US now shows that today's electric vehicles can meet all travel needs on almost 90% of days from a single overnight charge.

  16. Vehicle chassis monitoring system

    Energy Technology Data Exchange (ETDEWEB)

    Pisu, P.; Soliman, A.; Rizzoni, G. [Ohio State Univ., Columbus (United States). Center for Automotive Research

    2001-07-01

    Fault detection and isolation is becoming one of the most important aspects in vehicle control system design. In order to achieve this FDI schemes, particular vehicle subsystems integrated with a controller have been proposed. This paper introduces a new model-based fault detection and fault diagnosis method for monitoring the vehicle chassis performance. (orig.)

  17. Electric Vehicle Technician

    Science.gov (United States)

    Moore, Pam

    2011-01-01

    With President Obama's goal to have one million electric vehicles (EV) on the road by 2015, the electric vehicle technician should have a promising and busy future. "The job force in the car industry is ramping up for a revitalized green car industry," according to Greencareersguide.com. An electric vehicle technician will safely troubleshoot and…

  18. Automotive vehicle sensors

    Energy Technology Data Exchange (ETDEWEB)

    Sheen, S.H.; Raptis, A.C.; Moscynski, M.J.

    1995-09-01

    This report is an introduction to the field of automotive vehicle sensors. It contains a prototype data base for companies working in automotive vehicle sensors, as well as a prototype data base for automotive vehicle sensors. A market analysis is also included.

  19. Using an Unmanned Arial Vehicle (UAV) and a thermal infrared camera to estimate temperature differences on a lake surface, revealing incoming groundwater seepage.

    Science.gov (United States)

    Hoffmann, Helene; Müller, Sascha; Friborg, Thomas

    2014-05-01

    UAVs are at the budding stage of becoming efficient tools in geosciences due to their fast coverage of large areas, creating opportunities to collect comprehensive amounts of spatially distributed data. In this survey a fixed-wing UAV is equipped with a thermal infrared camera (Optris PI 450) conducting spatially distributed measurements of radiometric surface temperature, from a small groundwater-fed lake. We hypothesis that larger temperature differences in the lake surface will reveal locations of incoming groundwater seepage. During wintertime, warmer groundwater will have great incentive to rise to the lake surface without significant mixing with colder lake water and hence enable detection of incoming groundwater seepage with surface measurements. The investigated area is a 300x150 m section of Lake Vaeng in southern Jutland, Denmark. Detecting areas of groundwater seepage into lakes and quantifying these fluxes are of great importance not only for water budgets but also in relation to lake environments. Incoming groundwater might be a large nutrient source in lakes. GPS coordinates from the UAV are correlated with each thermal image based on UTC time stamps. Geo-reference is further improved with ground control points in the form of 0.2x0.2 m aluminum foil rectangles. Aluminum stands out clearly in thermal images and using seven of these ground control points, evenly distributed in the investigated area, led to an accuracy of 0.3 m. Using the Structure from Motion photogrammetric technique, a point cloud model is produced and camera positions along with intrinsic and extrinsic properties are established. Distinct temperature differences of 1.5 C have been detected along the south-eastern shore of Lake Vaeng. The location of these hotspots is in agreement with temperature differences measured with Distributed Temperature Sensing (DTS) system - indicating zones of groundwater seepage into the lake. In addition to faster execution of large spatially distributed

  20. Method and system for control of upstream flowfields of vehicle in supersonic or hypersonic atmospheric flight

    Science.gov (United States)

    Daso, Endwell O. (Inventor); Pritchett, II, Victor E. (Inventor); Wang, Ten-See (Inventor); Farr, Rebecca Ann (Inventor)

    2012-01-01

    The upstream flowfield of a vehicle traveling in supersonic or hypersonic atmospheric flight is actively controlled using attribute(s) experienced by the vehicle. Sensed attribute(s) include pressure along the vehicle's outer mold line, temperature along the vehicle's outer mold line, heat flux along the vehicle's outer mold line, and/or local acceleration response of the vehicle. A non-heated, non-plasma-producing gas is injected into an upstream flowfield of the vehicle from at least one surface location along the vehicle's outer mold line. The pressure of the gas so-injected is adjusted based on the attribute(s) so-sensed.

  1. Smart-Divert Powered Descent Guidance to Avoid the Backshell Landing Dispersion Ellipse

    Science.gov (United States)

    Carson, John M.; Acikmese, Behcet

    2013-01-01

    A smart-divert capability has been added into the Powered Descent Guidance (PDG) software originally developed for Mars pinpoint and precision landing. The smart-divert algorithm accounts for the landing dispersions of the entry backshell, which separates from the lander vehicle at the end of the parachute descent phase and prior to powered descent. The smart-divert PDG algorithm utilizes the onboard fuel and vehicle thrust vectoring to mitigate landing error in an intelligent way: ensuring that the lander touches down with minimum- fuel usage at the minimum distance from the desired landing location that also avoids impact by the descending backshell. The smart-divert PDG software implements a computationally efficient, convex formulation of the powered-descent guidance problem to provide pinpoint or precision-landing guidance solutions that are fuel-optimal and satisfy physical thrust bound and pointing constraints, as well as position and speed constraints. The initial smart-divert implementation enforced a lateral-divert corridor parallel to the ground velocity vector; this was based on guidance requirements for MSL (Mars Science Laboratory) landings. This initial method was overly conservative since the divert corridor was infinite in the down-range direction despite the backshell landing inside a calculable dispersion ellipse. Basing the divert constraint instead on a local tangent to the backshell dispersion ellipse in the direction of the desired landing site provides a far less conservative constraint. The resulting enhanced smart-divert PDG algorithm avoids impact with the descending backshell and has reduced conservatism.

  2. Six-degree-of-freedom guidance and control-entry analysis of the HL-20

    Science.gov (United States)

    Powell, Richard W.

    1993-10-01

    The ability of the HL-20 lifting body to fly has been evaluated for an automated entry from atmospheric interface to landing. This evaluation was required to demonstrate that not only successful touchdown conditions would be possible for this low lift-to-drag-ratio vehicle, but also the vehicle would not exceed its design dynamic pressure limit of 400 psf during entry. This dynamic pressure constraint limit, coupled with limited available pitch-control authority at low supersonic speeds, restricts the available maneuvering capability for the HL-20 to acquire the runway. One result of this analysis was that this restrictive maneuvering capability does not allow the use of a model-following atmospheric entry-guidance algorithm, such as that used by the Space Shuttle, but instead requires a more adaptable guidance algorithm. Therefore, for this analysis, a predictor-corrector guidance algorithm was developed that would provide successful touchdown conditions while not violating the dynamic pressure constraint. A flight-control system was designed and incorporated, along with the predictor-corrector guidance algorithm, into a six-DOF simulation. which showed that the HL-20 remained controllable and could reach the landing site and execute a successful landing under all off-nominal conditions simulated.

  3. Charging Guidance of Electric Taxis Based on Adaptive Particle Swarm Optimization.

    Science.gov (United States)

    Niu, Liyong; Zhang, Di

    2015-01-01

    Electric taxis are playing an important role in the application of electric vehicles. The actual operational data of electric taxis in Shenzhen, China, is analyzed, and, in allusion to the unbalanced time availability of the charging station equipment, the electric taxis charging guidance system is proposed basing on the charging station information and vehicle information. An electric taxis charging guidance model is established and guides the charging based on the positions of taxis and charging stations with adaptive mutation particle swarm optimization. The simulation is based on the actual data of Shenzhen charging stations, and the results show that electric taxis can be evenly distributed to the appropriate charging stations according to the charging pile numbers in charging stations after the charging guidance. The even distribution among the charging stations in the area will be achieved and the utilization of charging equipment will be improved, so the proposed charging guidance method is verified to be feasible. The improved utilization of charging equipment can save public charging infrastructure resources greatly.

  4. Charging Guidance of Electric Taxis Based on Adaptive Particle Swarm Optimization

    Directory of Open Access Journals (Sweden)

    Liyong Niu

    2015-01-01

    Full Text Available Electric taxis are playing an important role in the application of electric vehicles. The actual operational data of electric taxis in Shenzhen, China, is analyzed, and, in allusion to the unbalanced time availability of the charging station equipment, the electric taxis charging guidance system is proposed basing on the charging station information and vehicle information. An electric taxis charging guidance model is established and guides the charging based on the positions of taxis and charging stations with adaptive mutation particle swarm optimization. The simulation is based on the actual data of Shenzhen charging stations, and the results show that electric taxis can be evenly distributed to the appropriate charging stations according to the charging pile numbers in charging stations after the charging guidance. The even distribution among the charging stations in the area will be achieved and the utilization of charging equipment will be improved, so the proposed charging guidance method is verified to be feasible. The improved utilization of charging equipment can save public charging infrastructure resources greatly.

  5. 78 FR 37231 - Guidance for Industry; Guidance on Abbreviated New Drug Applications: Stability Testing of Drug...

    Science.gov (United States)

    2013-06-20

    ... HUMAN SERVICES Food and Drug Administration Guidance for Industry; Guidance on Abbreviated New Drug... the availability of a guidance for industry entitled ``ANDAs: Stability Testing of Drug Substances and... generic drug review, FDA is recommending that the generic drug industry follow the approach in...

  6. Guidance for evidence-informed policies about health systems: rationale for and challenges of guidance development.

    Directory of Open Access Journals (Sweden)

    Xavier Bosch-Capblanch

    Full Text Available In the first paper in a three-part series on health systems guidance, Xavier Bosch-Capblanch and colleagues examine how guidance is currently formulated in low- and middle-income countries, and the challenges to developing such guidance.

  7. Autonomous and cooperative multi-UAV guidance in adversarial environment

    Science.gov (United States)

    Zengin, Ugur

    The research presented in this dissertation is aimed at developing rule-based autonomous and cooperative guidance strategies for UAVs to perform missions such as path planning, target tracking and rendezvous while reducing their risk/threat exposure level, and avoiding threats and/or obstacles by utilizing measurement information provided by sensors. First, a mathematical formulation is developed to represent the area of operation that contains various types of threats, obstacles, and restricted areas, in a single framework. Once constructed, there will be no need to distinguish between threats, obstacles and restricted areas as the framework already contains the information on what needs to be avoided and the level of penalty for a given position in the area. This framework provides the mathematical foundation for the guidance strategies to make intelligent decisions during the execution of the mission and also provides scalar metrics to assess the performance of a guidance strategy in a given mission. The autonomous guidance strategies are developed by using a rule-based expert system approach with the requirements of completing assigned mission or task, avoiding obstacle/restricted-areas, minimizing threat exposure level, considering the dynamic and communication constraints of the UAVs and avoiding collision. All these requirements and objectives are quantified and prioritized to facilitate the development of guidance algorithms that can be executed in real-time. The strategies consist of a set of "decision states", which contain rules to determine how the host UAV should move by generating heading and speed signals. Cooperation of multiple UAVs is modeled by minimizing a cost function, which is constructed based on the level of threat exposure for each UAV and distance of each UAV relative to the target. This improves the performance of the system in the terms of increasing the total area of coverage of the sensors onboard the UAVs, increasing the flexibility

  8. Fourth-generation Mars vehicle concepts

    Science.gov (United States)

    Sherwood, Brent

    1994-09-01

    Conceptual designs for fourth-generation crew-carrying Mars transfer and excursion vehicles, fully integrated to state-of-the-art standards, are presented. The resulting vehicle concepts are sized for six crew members, and can support all opposition and conjunction opportunities in or after 2014. The modular, reusable transfer ship is launched to Earth orbit on six 185-ton-class boosters and assembled there robotically. Its dual nuclear-thermal rocket engines use liquid hydrogen propollant. The payload consists of a microgravity habitation system and an expendable lift-to-drag = 1.6 lander capable of aeromaneuvering to sites within +/- 20 deg of the equator. This lander can deliver either an expendable, storable-bipropellant crew-carrying ascent vehicle, or 40 tons of cargo, and it is capable of limited surface mobility to support base buildup. Multiple cargo landers sent ahead on robotic transfer vehicles deliver the supplies and equipment required for long-duration surface missions.

  9. Space vehicle chassis

    Energy Technology Data Exchange (ETDEWEB)

    Judd, Stephen; Dallmann, Nicholas; Seitz, Daniel; Martinez, John; Storms, Steven; Kestell, Gayle

    2017-07-18

    A modular space vehicle chassis may facilitate convenient access to internal components of the space vehicle. Each module may be removable from the others such that each module may be worked on individually. Multiple panels of at least one of the modules may swing open or otherwise be removable, exposing large portions of the internal components of the space vehicle. Such chassis architectures may reduce the time required for and difficulty of performing maintenance or modifications, may allow multiple space vehicles to take advantage of a common chassis design, and may further allow for highly customizable space vehicles.

  10. Integrated Navigation System for the Second Generation Reusable Launch Vehicle

    Science.gov (United States)

    2002-01-01

    An array of components in a laboratory at NASA's Marshall Space Flight Center (MSFC) is being tested by the Flight Mechanics Office to develop an integrated navigation system for the second generation reusable launch vehicle. The laboratory is testing Global Positioning System (GPS) components, a satellite-based location and navigation system, and Inertial Navigation System (INS) components, sensors on a vehicle that determine angular velocity and linear acceleration at various points. The GPS and INS components work together to provide a space vehicle with guidance and navigation, like the push of the OnStar button in your car assists you with directions to a specific address. The integration will enable the vehicle operating system to track where the vehicle is in space and define its trajectory. The use of INS components for navigation is not new to space technology. The Space Shuttle currently uses them. However, the Space Launch Initiative is expanding the technology to integrate GPS and INS components to allow the vehicle to better define its position and more accurately determine vehicle acceleration and velocity. This advanced technology will lower operational costs and enhance the safety of reusable launch vehicles by providing a more comprehensive navigation system with greater capabilities. In this photograph, Dr. Jason Chuang of MSFC inspects an INS component in the laboratory.

  11. Improving the Lane Reference Detection for Autonomous Road Vehicle Control

    Directory of Open Access Journals (Sweden)

    Felipe Jiménez

    2016-01-01

    Full Text Available Autonomous road vehicles are increasingly becoming more important and there are several techniques and sensors that are being applied for vehicle control. This paper presents an alternative system for maintaining the position of autonomous vehicles without adding additional elements to the standard sensor architecture, by using a 3D laser scanner for continuously detecting a reference element in situations in which the GNSS receiver fails or provides accuracy below the required level. Considering that the guidance variables are more accurately estimated when dealing with reference points in front of and behind the vehicle, an algorithm based on vehicle dynamics mathematical model is proposed to extend the detected points in cases where the sensor is placed at the front of the vehicle. The algorithm has been tested when driving along a lane delimited by New Jersey barriers at both sides and the results show a correct behaviour. The system is capable of estimating the reference element behind the vehicle with sufficient accuracy when the laser scanner is placed at the front of it, so the robustness of the control input variables (lateral and angular errors estimation is improved making it unnecessary to place the sensor on the vehicle roof or to introduce additional sensors.

  12. Broadband vehicle-to-vehicle communication using an extended autonomous cruise control sensor

    Science.gov (United States)

    Heddebaut, M.; Rioult, J.; Ghys, J. P.; Gransart, Ch; Ambellouis, S.

    2005-06-01

    For several years road vehicle autonomous cruise control (ACC) systems as well as anti-collision radar have been developed. Several manufacturers currently sell this equipment. The current generation of ACC sensors only track the first preceding vehicle to deduce its speed and position. These data are then used to compute, manage and optimize a safety distance between vehicles, thus providing some assistance to car drivers. However, in real conditions, to elaborate and update a real time driving solution, car drivers use information about speed and position of preceding and following vehicles. This information is essentially perceived using the driver's eyes, binocular stereoscopic vision performed through the windscreens and rear-view mirrors. Furthermore, within a line of vehicles, the frontal road perception of the first vehicle is very particular and highly significant. Currently, all these available data remain strictly on-board the vehicle that has captured the perception information and performed these measurements. To get the maximum effectiveness of all these approaches, we propose that this information be shared in real time with the following vehicles, within the convoy. On the basis of these considerations, this paper technically explores a cost-effective solution to extend the basic ACC sensor function in order to simultaneously provide a vehicle-to-vehicle radio link. This millimetre wave radio link transmits relevant broadband perception data (video, localization...) to following vehicles, along the line of vehicles. The propagation path between the vehicles uses essentially grazing angles of incidence of signals over the road surface including millimetre wave paths beneath the cars.

  13. Evaluation of some significant issues affecting trajectory and control management for air-breathing hypersonic vehicles

    Science.gov (United States)

    Hattis, Philip D.; Malchow, Harvey L.

    1992-01-01

    Horizontal takeoff airbreathing-propulsion launch vehicles require near-optimal guidance and control which takes into account performance sensitivities to atmospheric characteristics while satisfying physically-derived operational constraints. A generic trajectory/control analysis tool that deepens insight into these considerations has been applied to two versions of a winged-cone vehicle model. Information that is critical to the design and trajectory of these vehicles is derived, and several unusual characteristics of the airbreathing propulsion model are shown to have potentially substantial effects on vehicle dynamics.

  14. Guidance for performing preliminary assessments under CERCLA

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1991-09-01

    EPA headquarters and a national site assessment workgroup produced this guidance for Regional, State, and contractor staff who manage or perform preliminary assessments (PAs). EPA has focused this guidance on the types of sites and site conditions most commonly encountered. The PA approach described in this guidance is generally applicable to a wide variety of sites. However, because of the variability among sites, the amount of information available, and the level of investigative effort required, it is not possible to provide guidance that is equally applicable to all sites. PA investigators should recognize this and be aware that variation from this guidance may be necessary for some sites, particularly for PAs performed at Federal facilities, PAs conducted under EPA`s Environmental Priorities Initiative (EPI), and PAs at sites that have previously been extensively investigated by EPA or others. The purpose of this guidance is to provide instructions for conducting a PA and reporting results. This guidance discusses the information required to evaluate a site and how to obtain it, how to score a site, and reporting requirements. This document also provides guidelines and instruction on PA evaluation, scoring, and the use of standard PA scoresheets. The overall goal of this guidance is to assist PA investigators in conducting high-quality assessments that result in correct site screening or further action recommendations on a nationally consistent basis.

  15. Driving change : sustainable development action plans Guidance

    OpenAIRE

    Sustainable Development Commission

    2008-01-01

    This guidance builds upon the Sustainable Development Commission’s previous guidance, Getting Started (August 2005), which set out the basic elements that the Sustainable Development Commission would expect to see in a good Sustainable Development Action Plan. Publisher PDF Original published August 2005.

  16. Minimum variation guidance laws for interceptor missiles

    NARCIS (Netherlands)

    Weiss, M.; Shima, T.

    2014-01-01

    This paper introduces a new approach to guidance law design using linear quadratic optimal control theory, minimizing throughout the engagement the variation of the control input as well as the integral control effort. The guidance law is derived for arbitrary order missile dynamics and target maneu

  17. Career Guidance and Public Mental Health

    Science.gov (United States)

    Robertson, Peter J.

    2013-01-01

    Career guidance may have the potential to promote public health by contributing positively to both the prevention of mental health conditions and to population level well-being. The policy implications of this possibility have received little attention. Career guidance agencies are well placed to reach key target groups. Producing persuasive…

  18. 75 FR 53023 - Sound Incentive Compensation Guidance

    Science.gov (United States)

    2010-08-30

    ... principles and the guidance are consistent with the Principles for Sound Compensation Practices adopted by... of Management and Budget (OMB) for review, as required by the Paperwork Reduction Act. Today, OTS is.... Description: The guidance is based on three key principles that are designed to ensure that incentive...

  19. Driving change : sustainable development action plans Guidance

    OpenAIRE

    Sustainable Development Commission

    2008-01-01

    This guidance builds upon the Sustainable Development Commission’s previous guidance, Getting Started (August 2005), which set out the basic elements that the Sustainable Development Commission would expect to see in a good Sustainable Development Action Plan. Publisher PDF Original published August 2005.

  20. Loss Prediction and Thermal Analysis of Surface-Mounted Brushless AC PM Machines for Electric Vehicle Application Considering Driving Duty Cycle

    Directory of Open Access Journals (Sweden)

    Tianxun Chen

    2016-01-01

    Full Text Available This paper presents a computationally efficient loss prediction procedure and thermal analysis of surface-mounted brushless AC permanent magnet (PM machine considering the UDDS driving duty cycle by using a lumped parameters’ thermal model. The accurate prediction of loss and its variation with load are essential for thermal analysis. Employing finite element analysis (FEA to determine loss at every load point would be computationally intensive. Here, the finite element analysis and/or experiment based computationally efficient winding copper and iron loss and permanent magnet (PM power loss models are employed to calculate the electromagnetic loss at every operation point, respectively. Then, the lumped parameter thermal method is used to analyse the thermal behaviour of the driving PM machine. Experiments have been carried out to measure the temperature distribution in a motor prototype. The calculation and experiment results are compared and discussed.

  1. ROLLING NOISE SIMULATION OF A RAILWAY VEHICLE

    OpenAIRE

    Traian MAZILU

    2013-01-01

    Rolling noise of the railway vehicles is occurred by the wheel/rail vibration excited bythe rolling surfaces roughness. This paper presents an acoustic model able to predict the rollingnoise level of a railway vehicle. The acoustic model is based on a wheel/rail vibration modelwhich takes into account the structural wheel vibration (Remington model) and the bendingvertical waves of the rail. To this, the track model with an infinite Euler Bernoulli beam elasticallysupported on two layers is a...

  2. Holographic Analysis of Large Vehicle Structures

    Science.gov (United States)

    1982-07-01

    47 5.35 Driver’s Door, Engine Speed 3000 RPM, t=14ms 48 v Figure No. Figure Title Page No. 6.1 Graphic Illustration of the Relative Phase Shift Between...global dynamic information over large sections of the vibrating vehicle surface. This information provides a means for improving vehicle desing and...sensitivity which is important for large amplitude measurements. The resulting CW fringe pattern for the beam displacement is graphically illustrated in Figure

  3. Road Weather and Connected Vehicles

    Science.gov (United States)

    Pisano, P.; Boyce, B. C.

    2015-12-01

    On average, there are over 5.8 M vehicle crashes each year of which 23% are weather-related. Weather-related crashes are defined as those crashes that occur in adverse weather or on slick pavement. The vast majority of weather-related crashes happen on wet pavement (74%) and during rainfall (46%). Connected vehicle technologies hold the promise to transform road-weather management by providing improved road weather data in real time with greater temporal and geographic accuracy. This will dramatically expand the amount of data that can be used to assess, forecast, and address the impacts that weather has on roads, vehicles, and travelers. The use of vehicle-based measurements of the road and surrounding atmosphere with other, more traditional weather data sources, and create road and atmospheric hazard products for a variety of users. The broad availability of road weather data from mobile sources will vastly improve the ability to detect and forecast weather and road conditions, and will provide the capability to manage road-weather response on specific roadway links. The RWMP is currently demonstrating how weather, road conditions, and related vehicle data can be used for decision making through an innovative Integrated Mobile Observations project. FHWA is partnering with 3 DOTs (MN, MI, & NV) to pilot these applications. One is a mobile alerts application called the Motorists Advisories and Warnings (MAW) and a maintenance decision support application. These applications blend traditional weather information (e.g., radar, surface stations) with mobile vehicle data (e.g., temperature, brake status, wiper status) to determine current weather conditions. These weather conditions, and other road-travel-relevant information, are provided to users via web and phone applications. The MAW provides nowcasts and short-term forecasts out to 24 hours while the EMDSS application can provide forecasts up to 72 hours in advance. The three DOTs have placed readers and external

  4. Advanced Vehicle and Power Initiative

    Science.gov (United States)

    2010-07-29

    bases.) Qualifying advanced propulsion vehicles for this initiative are battery electric vehicles (BEV), hybrid electric vehicles (HEV), hybrid...hydraulic vehicles (HHV), plug-in hybrid electric vehicles (PHEV) and fuel cell electric vehicles (FCEV). The AVPI integrates use of renewable energy at

  5. Orbital maneuvering vehicle: A new capability

    Science.gov (United States)

    Huber, William G.

    The Orbital Maneuvering Vehicle (OMV) is a reusable, remotely controlled, free-flying vehicle being developed by NASA to perform a wide range of on-orbit missions and services in support of orbiting spacecraft. The OMV is capable of satellite delivery, retrieval, reboost, controlled deorbit, viewing, and subsatellite support missions. It is an important extension to the Space Transportation System and a key element of the Space Station operational scenario. The OMV can operate from the Shuttle, the Space Station, or can be space based. The OMV, being 15 ft in diameter and approximately 4 1/2 thick, mounts directly into the Shuttle payload bay. The vehicle design is highly modular, consisting of a Short Range Vehicle containing both hydrazine and cold gas RCS systems and all the avionics systems for electrical power, communications, data management, guidance, navigation, and 6-degree of freedom control. This vehicle weighs approximately 6,500 lb and can accomplish a high percentage of the project missions. For high delta-velocity missions, a bipropellant Propulsion Module (approximately 11,000lb) is added, giving a total weight of 17,500 lb. This module can be exchanged on orbit to effect bipropellant refueling. All the RCS and avionics modules are replaceable on orbit for maintenance. The OMV development program was initiated in 1986 with the selection of TRW as the prime contractor. The first flight is projected for 1991. An early planned use of OMV is to reboost the Hubble Space Telescope when required because of atmospheric drag. This paper contains details of the program status, vehicle description, and mission capabilities. The purpose of the paper is to acquaint the international space community with OMV capabilities and to stimulate the identification of new and unique mission applications.

  6. In-vehicle nitrogen dioxide concentrations in road tunnels

    Science.gov (United States)

    Martin, Ashley N.; Boulter, Paul G.; Roddis, Damon; McDonough, Liza; Patterson, Michael; Rodriguez del Barco, Marina; Mattes, Andrew; Knibbs, Luke D.

    2016-11-01

    There is a lack of knowledge regarding in-vehicle concentrations of nitrogen dioxide (NO2) during transit through road tunnels in urban environments. Furthermore, previous studies have tended to involve a single vehicle and the range of in-vehicle NO2 concentrations that vehicle occupants may be exposed to is not well defined. This study describes simultaneous measurements of in-vehicle and outside-vehicle NO2 concentrations on a route through Sydney, Australia that included several major tunnels, minor tunnels and busy surface roads. Tests were conducted on nine passenger vehicles to assess how vehicle characteristics and ventilation settings affected in-vehicle NO2 concentrations and the in-vehicle-to-outside vehicle (I/O) concentration ratio. NO2 was measured directly using a cavity attenuated phase shift (CAPS) technique that gave a high temporal and spatial resolution. In the major tunnels, transit-average in-vehicle NO2 concentrations were lower than outside-vehicle concentrations for all vehicles with cabin air recirculation either on or off. However, markedly lower I/O ratios were obtained with recirculation on (0.08-0.36), suggesting that vehicle occupants can significantly lower their exposure to NO2 in tunnels by switching recirculation on. The highest mean I/O ratios for NO2 were measured in older vehicles (0.35-0.36), which is attributed to older vehicles having higher air exchange rates. The results from this study can be used to inform the design and operation of future road tunnels and modelling of personal exposure to NO2.

  7. Advances in Orion's On-Orbit Guidance and Targeting System Architecture

    Science.gov (United States)

    Scarritt, Sara K.; Fill, Thomas; Robinson, Shane

    2015-01-01

    NASA's manned spaceflight programs have a rich history of advancing onboard guidance and targeting technology. In order to support future missions, the guidance and targeting architecture for the Orion Multi-Purpose Crew Vehicle must be able to operate in complete autonomy, without any support from the ground. Orion's guidance and targeting system must be sufficiently flexible to easily adapt to a wide array of undecided future missions, yet also not cause an undue computational burden on the flight computer. This presents a unique design challenge from the perspective of both algorithm development and system architecture construction. The present work shows how Orion's guidance and targeting system addresses these challenges. On the algorithm side, the system advances the state-of-the-art by: (1) steering burns with a simple closed-loop guidance strategy based on Shuttle heritage, and (2) planning maneuvers with a cutting-edge two-level targeting routine. These algorithms are then placed into an architecture designed to leverage the advantages of each and ensure that they function in concert with one another. The resulting system is characterized by modularity and simplicity. As such, it is adaptable to the on-orbit phases of any future mission that Orion may attempt.

  8. Battery Test Manual For 48 Volt Mild Hybrid Electric Vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Lee Kenneth [Idaho National Laboratory

    2017-03-01

    This manual details the U.S. Advanced Battery Consortium and U.S. Department of Energy Vehicle Technologies Program goals, test methods, and analysis techniques for a 48 Volt Mild Hybrid Electric Vehicle system. The test methods are outlined stating with characterization tests, followed by life tests. The final section details standardized analysis techniques for 48 V systems that allow for the comparison of different programs that use this manual. An example test plan is included, along with guidance to filling in gap table numbers.

  9. 76 FR 63676 - Final Division of Safety Systems Interim Staff Guidance DSS-ISG-2010-01: Staff Guidance Regarding...

    Science.gov (United States)

    2011-10-13

    ... COMMISSION Final Division of Safety Systems Interim Staff Guidance DSS-ISG- 2010-01: Staff Guidance Regarding... final Division of Safety Systems Interim Staff Guidance, (DSS-ISG) DSS- ISG-2010-01, ``Staff Guidance... guidance to the NRC staff reviewer to address the increased complexity of recent spent fuel pool...

  10. Augmented Reality Repair Guidance System

    Directory of Open Access Journals (Sweden)

    Sidharth Bhatia

    2012-07-01

    Full Text Available The daily life of a common man revolves around various forms of appliances/gadgets he uses throughout the day such as a mobile phone, laptop, printer, microwave oven, washing machine, etc. Although these appliances/gadgets are taken by most of the people for granted, the problem occurs when any of these things do not work as they are expected to. Getting them to the repair shops for every small glitch is expensive as well as time consuming. Although most of the companies which produce these appliances/gadgets do supply them with basic manuals, which deal with how to solve these minor issues, but reading them and at the same time repairing the corresponding appliance/gadget can be a frustrating task at times. These problems can be reduced to a large extent if some kind of live guidance is available. In this paper we propose a method to do so with the help of an augmented reality based system that will guide the user to carry out small scale repair jobs on these gadgets. All that is required is a decent webcam and a computing device, with a processor of 1 GHz or more and a display screen.

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

    Science.gov (United States)

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

    1975-01-01

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

  12. 78 FR 54949 - Major Project Financial Plan Guidance

    Science.gov (United States)

    2013-09-06

    ... TRANSPORTATION Federal Highway Administration Major Project Financial Plan Guidance AGENCY: Federal Highway... Major Project Financial Plan Guidance outlining the procedures the FHWA will follow when reviewing and approving Financial Plans. The proposed Major Project Financial Plan Guidance incorporates changes required...

  13. Correlation analysis-based image segmentation approach for automatic agriculture vehicle

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    It is important to segment image correctly to extract guidance information for automatic agriculture vehicle. If we can make the computer know where the crops are, we can extract the guidance line easily. Images were divided into some rectangle small windows, then a pair of 1-D arrays was constructed in each small windows. The correlation coefficients of every small window constructed the features to segment images. The results showed that correlation analysis is a potential approach for processing complex farmland for guidance system, and more correlation analysis methods must be researched.

  14. Terrain Aided Navigation for Remus Autonomous Underwater Vehicle

    Science.gov (United States)

    2014-06-01

    NAVIGATION FOR REMUS AUTONOMOUS UNDERWATER VEHICLE by Jacob T. Juriga June 2014 Thesis Advisor: Doug Horner Second Reader: Noel DuToit...2014 Author: Jacob T. Juriga Approved by: Doug Horner Thesis Advisor Noel Du Toit Second Reader Garth Hobson Chair...I would like to acknowledge my advisor, Dr. Doug Horner , for his guidance and assistance throughout this process. His help was very much appreciated

  15. nowCOAST's Map Service for NOAA NOS St. Johns River Operational Forecast System (SJROFS) Forecast Guidance (Time Enabled)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Map Information: This nowCOAST time-enabled map service provides maps of the latest nowcasts and forecast guidance of surface water temperature, salinity, and water...

  16. nowCOAST's Map Service for NOAA NOS Delaware Bay Operational Forecast System (DBOFS) Forecast Guidance (Time Offsets)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Map Information: This nowCOAST time-offsets map service provides maps of the latest nowcasts and forecast guidance of surface water temperature, salinity, water...

  17. Guidance for Testing and Labeling Claims against Pandemic 2009 H1N1 Influenza A Virus (Formerly called Swine Flu )

    Science.gov (United States)

    This document provides guidance labeling and testing for antimicrobial pesticides in several forms that are used to treat hard non-porous surfaces in healthcare facilities and other settings against Pandemic 2009 H1N1 influenza A Virus.

  18. nowCOAST's Map Service for NOAA NOS Delaware Bay Operational Forecast System (DBOFS) Forecast Guidance (Time Enabled)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Map Information: This nowCOAST time-enabled map service provides maps of the latest nowcasts and forecast guidance of surface water temperature, salinity, and water...

  19. nowCOAST's Map Service for NOAA NOS St. Johns River Operational Forecast System (SJROFS) Forecast Guidance (Time Offsets)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Map Information: This nowCOAST time-offsets map service provides maps of the latest nowcasts and forecast guidance of surface water temperature, salinity, and water...

  20. Steering Performance, Tactical Vehicles

    Science.gov (United States)

    2015-07-29

    NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Automotive Instrumentation Division (TEDT-AT-AD-I) U.S. Army Aberdeen Test Center 400...characterize the on-center vehicle responses of military vehicles for the purposes of influencing vehicle design and ensuring military truck steering... mechanism attached to the test vehicle’s steering wheel (or replaces the steering wheel) that is strain gaged and calibrated to measure the steering effort

  1. Ground Vehicle Robotics

    Science.gov (United States)

    2013-08-20

    Ground Vehicle Robotics Jim Parker Associate Director, Ground Vehicle Robotics UNCLASSIFIED: Distribution Statement A. Approved for public...DATE 20 AUG 2013 2. REPORT TYPE Briefing Charts 3. DATES COVERED 09-05-2013 to 15-08-2013 4. TITLE AND SUBTITLE Ground Vehicle Robotics 5a...Willing to take Risk on technology -User Evaluated -Contested Environments -Operational Data Applied Robotics for Installation & Base Ops -Low Risk

  2. Electric Vehicle Propulsion System

    OpenAIRE

    2014-01-01

    Electric vehicles are being considered as one of the pillar of eco-friendly solutions to overcome the problem of global pollution and radiations due to greenhouse gases. Present thesis work reports the improvement in overall performance of the propulsion system of an electric vehicle by improving autonomy and torque-speed characteristic. Electric vehicle propulsion system consists of supply and traction system, and are coordinated by the monitoring & control system. Case of light electric veh...

  3. Optimization of Vehicle Defrosting Performance Based on Program Integration and Response Surface Model%基于程序集成及响应面模型的车辆除霜性能优化

    Institute of Scientific and Technical Information of China (English)

    张炳力; 胡忠文; 薛铁龙

    2015-01-01

    A three-dimensional simulation model for the defrosting performance of a car is created. With the grill angles of air duct outlet are selected as experimental factors and the heating air speed on windshield sur-face as objective function, and by using program integration to make Isight as upper layer software and integrating automatic mesh deformation software Sculptor with CFD software Star-ccm+, the sample data are obtained by auto-matic submission for calculation. The Latin hypercube design and the least square method are used to create a sec-ond-order response surface model for the heating air speed on windshield surface, and a parameter optimization is conducted with mixed-integer optimization algorithm. After optimization, the distribution of heating air speed on windshield surface is obviously improved and the results of transient simulation on defrosting show that the defros-ting speed is increased, meeting the requirements of national standard on the defrosting performance of vehicle windshield.%建立了某款轿车除霜仿真三维模型。选择风道出口格栅角度为试验因子,风窗玻璃表面风速为目标函数,使用程序集成的方法,将Isight作为上层软件,集成自动网格变形软件Sculptor和CFD计算软件Star-ccm+,自动提交运算得到样本数据。采用拉丁超立方设计方法和最小二乘法,创建了汽车风窗玻璃表面暖风风速的二阶响应面模型,利用混合整型优化法进行参数优化。优化后,汽车前风窗玻璃表面的除霜暖风流速分布有了明显的改善,除霜瞬态仿真结果表明,除霜速度加快,满足了国标关于汽车风窗玻璃除霜性能的要求。

  4. Guidance of magnetic space tug

    Science.gov (United States)

    Fabacher, Emilien; Lizy-Destrez, Stéphanie; Alazard, Daniel; Ankersen, Finn; Profizi, Alexandre

    2017-07-01

    Magnetic tugging of a target satellite without thrust capacity can be interesting in various contexts, as for example End-Of-Life management, or to complete launchers capabilities. The aim is to gradually modify the orbit of the target by constantly exerting on it a magnetic force. To do so, the chaser is assumed equipped with a steerable magnetic dipole, able to create both forces and torques on the magnetic torque rods carried by the target. The chaser is also supposed to carry electric thrusters, creating a continuous force which modifies the orbit of the whole formation composed of chaser and target. The relative motions of both satellites are derived, in order to assess the feasibility of such a concept. Relative configuration (attitudes and position) trajectories are derived, which are compliant with the dynamics, and enable the chaser to tug the target. Considering targets in Low Earth Orbit (LEO), the magnetic field of the Earth is taken into account, modeled by the International Geomagnetic Reference Field (IGRF). The position of the magnetic torque rod of the target may not be located at its center of mass. This lever-arm is taken into account in the dynamics. As for every Electro-Magnetic Formation Flight concept developed in the literature, satellites involved in magnetic tugging are constantly subjected to torques, created by the Earth magnetic field and by the magnetic fields created by the other satellites in the formation. In this study, the solution chosen to face this problem is to take into account the attitude equilibrium of the satellites early in the guidance phase, in order to avoid having to wave the dipole, as it is generally done. Promising results are presented for different types of orbit, showing that the concept could be feasible in many different scenarios.

  5. Significant Guidance Issued by the Federal Highway Administration

    Data.gov (United States)

    Department of Transportation — A list of Significant Guidance documents, which include guidance document disseminated to regulated entities or the general public that may reasonably be anticipated...

  6. Significant Guidance Issued by the Federal Aviation Administration

    Data.gov (United States)

    Department of Transportation — A list of Significant Guidance documents, which include guidance document disseminated to regulated entities or the general public that may reasonably be anticipated...

  7. Significant Guidance Issued by the Federal Transit Administration

    Data.gov (United States)

    Department of Transportation — A list of Significant Guidance documents, which include guidance document disseminated to regulated entities or the general public that may reasonably be anticipated...

  8. Significant Guidance Issued by the Federal Motor Carrier Safety Administration

    Data.gov (United States)

    Department of Transportation — A list of Significant Guidance documents, which include guidance document disseminated to regulated entities or the general public that may reasonably be anticipated...

  9. Electric vehicle propulsion alternatives

    Science.gov (United States)

    Secunde, R. R.; Schuh, R. M.; Beach, R. F.

    1983-01-01

    Propulsion technology development for electric vehicles is summarized. Analytical studies, technology evaluation, and the development of technology for motors, controllers, transmissions, and complete propulsion systems are included.

  10. Collision avoidance ZEM/ZEV optimal feedback guidance for powered descent phase of landing on Mars

    Science.gov (United States)

    Zhang, Yao; Guo, Yanning; Ma, Guangfu; Zeng, Tianyi

    2017-03-01

    A novel zero-effort-miss (ZEM)/zero-effort-velocity (ZEV) optimal feedback guidance is proposed in order to rule out the possibility of Martian surface collision caused by the classical ZEM/ZEV optimal feedback guidance. The main approach is to add a collision avoidance term, which has self-adjustment capacity to ensure the near fuel optimality. Its main improvement is that it can not only successfully avoid collisions with the thruster constraint but also guarantee the near fuel optimality, and both of them are pivotal performances in Mars landing missions. Simulations are made to show the effectiveness of the proposed guidance and the parameters effects are simulated as well to analyze the properties of the proposed guidance.

  11. 75 FR 76692 - Federal Motor Vehicle Safety Standards; Small Business Impacts of Motor Vehicle Safety

    Science.gov (United States)

    2010-12-09

    ..., and 571 Federal Motor Vehicle Safety Standards; Small Business Impacts of Motor Vehicle Safety AGENCY... passenger vehicles, trucks, buses, trailers, incomplete vehicles, motorcycles, and motor vehicle...

  12. Performance evaluation and design of flight vehicle control systems

    CERN Document Server

    Falangas, Eric T

    2015-01-01

    This book will help students, control engineers and flight dynamics analysts to model and conduct sophisticated and systemic analyses of early flight vehicle designs controlled with multiple types of effectors and to design and evaluate new vehicle concepts in terms of satisfying mission and performance goals. Performance Evaluation and Design of Flight Vehicle Control Systems begins by creating a dynamic model of a generic flight vehicle that includes a range of elements from airplanes and launch vehicles to re-entry vehicles and spacecraft. The models may include dynamic effects dealing with structural flexibility, as well as dynamic coupling between structures and actuators, propellant sloshing, and aeroelasticity, and they are typically used for control analysis and design. The book shows how to efficiently combine different types of effectors together, such as aero-surfaces, TVC, throttling engines and RCS, to operate as a system by developing a mixing logic atrix. Methods of trimming a vehicle controll...

  13. A semi-analytical guidance algorithm for autonomous landing

    Science.gov (United States)

    Lunghi, Paolo; Lavagna, Michèle; Armellin, Roberto

    2015-06-01

    One of the main challenges posed by the next space systems generation is the high level of autonomy they will require. Hazard Detection and Avoidance is a key technology in this context. An adaptive guidance algorithm for landing that updates the trajectory to the surface by means of an optimal control problem solving is here presented. A semi-analytical approach is proposed. The trajectory is expressed in a polynomial form of minimum order to satisfy a set of boundary constraints derived from initial and final states and attitude requirements. By imposing boundary conditions, a fully determined guidance profile is obtained, function of a restricted set of parameters. The guidance computation is reduced to the determination of these parameters in order to satisfy path constraints and other additional constraints not implicitly satisfied by the polynomial formulation. The algorithm is applied to two different scenarios, a lunar landing and an asteroidal landing, to highlight its general validity. An extensive Monte Carlo test campaign is conducted to verify the versatility of the algorithm in realistic cases, by the introduction of attitude control systems, thrust modulation, and navigation errors. The proposed approach proved to be flexible and accurate, granting a precision of a few meters at touchdown.

  14. Optimal guidance for the space shuttle transition

    Science.gov (United States)

    Stengel, R. F.

    1974-01-01

    A guidance method for the space shuttle's transition from hypersonic entry to subsonic cruising flight is presented. The method evolves from a numerical trajectory optimization technique in which kinetic energy and total energy (per unit weight) replace velocity and time in the dynamic equations. This allows the open end-time problem to be transformed to one of fixed terminal energy. In its ultimate form, E-Guidance obtains energy balance (including dynamic-pressure-rate damping) and path length control by angle-of-attack modulation and cross-range control by roll angle modulation. The guidance functions also form the basis for a pilot display of instantaneous maneuver limits and destination. Numerical results illustrate the E-Guidance concept and the optimal trajectories on which it is based.

  15. RCRA Programmatic Information Policy and Guidance

    Data.gov (United States)

    U.S. Environmental Protection Agency — This asset includes program policy and guidance documents that are used by the EPA regions, states, tribes and private parties to implement the hazardous waste...

  16. Tests and Guidance: What Students Need.

    Science.gov (United States)

    Krumboltz, John D.

    1982-01-01

    Innovations in testing and guidance which can integrate assessment to facilitate learning, help develop practical wisdom in behavior, and correct students' faulty cognitions in career decisions are described. (CM)

  17. Beyond Black: An Alternative to Ethnocentric Guidance

    Science.gov (United States)

    Goldman, Robert C.

    1977-01-01

    This article is a clarification of the author's personal philosophy in the guidance and counseling of youth and adults, and clarification of commonalities that form the raison d'etre of all student personnel services. (Author)

  18. Much more than just another guidance document.

    Science.gov (United States)

    Kulkarni, K

    2016-11-01

    As a pediatric hematologist oncologist with clinical and research interests in thrombosis in high-risk pediatric populations, and also as a member of the ISTH Early Career Task Force, I had the opportunity to develop a guidance document on 'Thromboprophylaxis for central venous catheters in the pediatric population' for the 'Guidelines and Guidance Documents' committee. In this communication, I share my experiences to date; I discuss my excitement and initial success, the steep learning curve required to build research acumen, the lessons learnt, and the opportunities and challenges faced. My experience with preparing the guidance document was much more than writing 'just another guidance document'. © 2016 International Society on Thrombosis and Haemostasis.

  19. Attitude and Translation Control of a Solar Sail Vehicle

    Science.gov (United States)

    Singh, Gurkirpal

    2008-01-01

    A report discusses the ability to control the attitude and translation degrees-of-freedom of a solar sail vehicle by changing its center of gravity. A movement of the spacecraft s center of mass causes solar-pressure force to apply a torque to the vehicle. At the compact core of the solar-sail vehicle lies the spacecraft bus which is a large fraction of the total vehicle mass. In this concept, the bus is attached to the spacecraft by two single degree-of-freedom linear tracks. This allows relative movement of the bus in the sail plane. At the null position, the resulting solar pressure applies no torque to the vehicle. But any deviation of the bus from the null creates an offset between the spacecraft center of mass and center of solar radiation pressure, resulting in a solar-pressure torque on the vehicle which changes the vehicle attitude. Two of the three vehicle degrees of freedom can be actively controlled in this manner. The third, the roll about the sunline, requires a low-authority vane/propulsive subsystem. Translation control of the vehicle is achieved by directing the solar-pressure-induced force in the proper inertial direction. This requires attitude control. Attitude and translation degrees-of-freedom are therefore coupled. A guidance law is proposed, which allows the vehicle to stationkeep at an appropriate point on the inertially-rotating Sun-Earth line. Power requirements for moving the bus are minimal. Extensive software simulations have been performed to demonstrate the feasibility of this concept.

  20. FY2011 Annual Progress Report for Vehicle and Systems Simulation and Testing

    Energy Technology Data Exchange (ETDEWEB)

    None

    2012-01-15

    The VSST team's mission is to evaluate the technologies and performance characteristics of advanced automotive powertrain components and subsystems in an integrated vehicle systems context. These evaluations address light-, medium-, and heavy-duty vehicle platforms. This work is directed toward evaluating and verifying the targets of the VTP R&D teams and to providing guidance in establishing roadmaps for achievement of these goals.