2010 Tactical Wheeled Vehicles Conference

DTIC Science & Technology

2010-02-09

Golf Tournament Player check-in & Continental Breakfast Black Horse Golf Course, Seaside, California (Golf Tournament Chair: Chuck...Restructuring materiel modernization strategies • Fielding “incremental” vs. “big bang” solutions • Transitioning to support the establishment of the...Executing a r esponsible draw down from Iraq  Building cap acity in Afghani stan to achieve U.S. objectives  Fielding impr oved Soldier cap abilities

Cyber Security Considerations for Autonomous Tactical Wheeled Vehicles

DTIC Science & Technology

2016-04-01

extraordinarily significant (Office of the Press Secretary, 2015). The White House added that cybersecurity is a shared responsibility between the...cannot, nor would Americans want it to, provide cybersecurity for every private network. Therefore, the private sector plays a crucial role in our... Cybersecurity Initiative,” that established the procedures the Acquisition community should use to manage future of Acquisition programs. Cyber Security

ITS Technologies in Military Wheeled Tactical Vehicles: Status Quo and the Future

DOE Office of Scientific and Technical Information (OSTI.GOV)

Knee, H.E.

2001-07-02

The U.S. Army operates and maintains the largest trucking fleet in the United States. Its fleet consists of over 246,000 trucks, and it is responsible for buying and developing trucks for all branches of the armed forces. The Army's tactical wheeled vehicle fleet is the logistical backbone of the Army, and annually, the fleet logs about 823 million miles. The fleet consists of a number of types of vehicles. They include eight different families of trucks from the High Mobility Multi-Purpose Wheeled Vehicles to M900 series line haul tractors and special bodies. The average age of all the trucks withinmore » the Army fleet is 15 years, and very few have more than traditional driving instrumentation on-board. Over the past decade, the Department of Transportation's (DOT's) Intelligent Transportation Systems (ITS) Program has conducted research and deployment activities in a number of areas including in-vehicle systems, communication and telematics technologies. Many current model passenger vehicles have demonstrated the assimilation of these technologies to enhance safety and trip quality. Commercial vehicles are also demonstrating many new electronic devices that are assisting in making them safer and more efficient. Moreover, a plethora of new technologies are about to be introduced to drivers that promise greater safety, enhanced efficiency, congestion avoidance, fuel usage reduction, and enhanced trip quality. The U.S. Army has special needs with regard to fleet management, logistics, sustainability, reliability, survivability, and fuel consumption that goes beyond similar requirements within the private industry. In order to effectively apply emerging ITS technologies to the special needs of the U.S. Army, planning for the conduct of the Army's Vehicle Intelligence Program (AVIP) has now commenced. The AVIP will be focused on the conduct of research that: (1) will apply ITS technologies to the special needs of the Army, and (2) will conduct research for special needs wi th regard to vehicle control, driver assistance, integration of vehicle intelligence and robotic technologies, managing effectively the information flow to drivers, enhanced logistics capabilities and sustainability of the Army's fleet during battlefield conditions. This paper will highlight the special needs of the Army, briefly describe two programs, which are embracing ITS technologies to a limited extent, will outline the AVIP, and will provide some insight into future Army vehicle intelligence efforts.« less

Tactical Wheeled Vehicle Survivability: Results of Experiments to Quantify Aboveground Impulse

DTIC Science & Technology

2010-03-01

in each testbed are pre- sented in Table 4.7. For all the clay soil experiments, the mean value of wet density was 121.2 lb/ft3, and the mean value...4.7. Summary of clay soil test series. Experiment Number Charge Position Avg Wet Density , lb/ft3 Avg Dry Density , lb/ft3 Avg Water... Clay soil ................................................................................................................................... 81

Software control architecture for autonomous vehicles

NASA Astrophysics Data System (ADS)

Nelson, Michael L.; DeAnda, Juan R.; Fox, Richard K.; Meng, Xiannong

1999-07-01

The Strategic-Tactical-Execution Software Control Architecture (STESCA) is a tri-level approach to controlling autonomous vehicles. Using an object-oriented approach, STESCA has been developed as a generalization of the Rational Behavior Model (RBM). STESCA was initially implemented for the Phoenix Autonomous Underwater Vehicle (Naval Postgraduate School -- Monterey, CA), and is currently being implemented for the Pioneer AT land-based wheeled vehicle. The goals of STESCA are twofold. First is to create a generic framework to simplify the process of creating a software control architecture for autonomous vehicles of any type. Second is to allow for mission specification system by 'anyone' with minimal training to control the overall vehicle functionality. This paper describes the prototype implementation of STESCA for the Pioneer AT.

Recapitalization and Acquisition of Light Tactical Wheeled Vehicles (REDACTED)

DTIC Science & Technology

2010-01-29

representative from Red River Army Depot in Texarkana , Texas,18 stated that recapitalizing current HMMWVs to the XM1166 model was an excellent proposition...Red River Army Depot in Texarkana , Texas, stated that recapitalizing current HMMWVs to the XM1166 model was an excellent proposition. The Deputy...Army Depot in Texarkana , Texas, stated that recapitalizing current HMMWVs to the XM1166 model was an excellent proposition because the U.S

The U.S. Combat and Tactical Wheeled Vehicle Fleets: Issues and Suggestions for Congress

DTIC Science & Technology

2011-01-01

nonlinear, irregular distribution of brigade and battalion formations means that there is no longer a relatively more secure rear area, an...enhancement package, according to civilian sources, included depleted- uranium armor, digital command- and-control architecture, digital color terrain maps...system robustness and flexibility, and (3) more often than not, the preparation of the analysis (e.g., terrain formatting , laydown of forces, timing of

Spatial multibody modeling and vehicle dynamics analysis of advanced vehicle technologies

NASA Astrophysics Data System (ADS)

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

2004-08-01

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

Feasibility of Using Full Synthetic Low Viscosity Engine Oil at High Ambient Temperatures in U.S. Army Engines

DTIC Science & Technology

2011-06-01

Approved for public release; distribution unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT Advancements in lubricant technology over the last two decades...in particular, the availability of high quality synthetic base oils, has set the stage for the development of a new fuel efficient, multifunctional...were conducted following two standard military testing cycles; the 210 h Tactical Wheeled Vehicle Cycle, and the 400 h NATO Hardware Endurance

Practical To Tactical: Making the Case for a Shift in Ground Vehicle Robotics

DTIC Science & Technology

2012-05-10

with Driver Warning I C R M x x x V x UNCLASSIFIED 21 Electronic Brake System ( ELB ) w/ Electronic Stability Control (ESC) Electric Power Assist...System ( ELB ) w/ Electronic Stability Control (ESC) Electric Power Assist Steering Steering Position Sensor Steering Torque Sensor Transmission...Computer I C R M x x x V x x Wheel Speed Sensors ESC Accelerometer/Rate Gyro UNCLASSIFIED 23 Electronic Brake System ( ELB ) w/ Electronic

2008 Tactical Wheeled Vehicles Conference (TWV) Volume 3

DTIC Science & Technology

2008-02-05

Armor/ GPK OTHER SIGNIFICANT PROCUREMENT EFFORTS Project Manager COL Scott R. Kidd Deputy PM Acquisition: Tony Shaw Deputy PM Logistics: Cesare Gaglio r...Support Modularity/ Grow the Army Full spectrum support to the War Fight & Modularity LSACM1117 ASV Production Frag Kit 5/ GPK TPE Refurb Gunner Restraint...Harness HEMTT AoA LSAC Production Objective – Gunner Protection Kit (O- GPK ) HMMWV HTV FMTV M1151/52 20 3 CSL PMs ~ Approximately 220K Systems Fielded

2007 Tactical Wheeled Vehicles Conference (TWV)

DTIC Science & Technology

2007-02-06

Reception and Super Bowl Party The DeAnza Ballroom I and II Monday, February 5, 2007 7:00 a.m. - 8:00 a.m. Continental Breakfast Serra... Reception The DeAnza Ballroom I and II The Portola Plaza Hotel at Monterey Bay Evening on Own - Enjoy Monterey! Tuesday, February 6, 2007 7:00...M967, M969, M870) 2006 2008 | 2007 | 2009 | Tech Insertion HMMWV FMTV HEMTT 915 Trailers 2010 | TD TD TD TD TD TD TD TD TD TD TD Expedited

Logistical Support of a Multiple Launch Rocket System (MLRS) Battalion During Operations Desert Shield/Storm

DTIC Science & Technology

1993-04-25

assembly area (AA) was located approximately 5 km due south of the Corps’ most Forward Operating Base (FOB) Bastone . FOB Bastone was located along the...area again was 5 km south of FOB Bastone . The battalion was finally in a tactical position from which we could quickly support combat operations, if...wheel vehicles operational. We coordinated with the 12th Avn Bde headquarters, stationed at FOB Bastone , to send two NCO’s on their log bird going to

Achieving integrated convoys: cargo unmanned ground vehicle development and experimentation

NASA Astrophysics Data System (ADS)

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

2013-05-01

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

Stabilizing Wheels For Rover Vehicle

NASA Technical Reports Server (NTRS)

Collins, Earl R., Jr.

1990-01-01

Proposed articulated, normally-four-wheeled vehicle holds extra pair of wheels in reserve. Deployed to lengthen wheelbase on slopes, thereby making vehicle more stable, and to aid vehicle in negotiating ledge or to right vehicle if turned upside down. Extra wheels are drive wheels mounted on arms so they pivot on axis of forward drive wheels. Both extra wheels and arms driven by chains, hydraulic motors, or electric motors. Concept promises to make remotely controlled vehicles more stable and maneuverable in such applications as firefighting, handling hazardous materials, and carrying out operations in dangerous locations.

High-Clearance Six-Wheel Suspension

NASA Technical Reports Server (NTRS)

Bickler, Donald B.

1992-01-01

Multilevered suspension system gives body of vehicle high clearance and allows wheels to be steered independently. Suspension linkages above wheels enable body to skim over obstacles as high as wheel. Levers and independently steered wheels enable vehicle to climb steps 1 1/2 wheel diameters high and cross gaps 1 3/4 wide. Adaptable to off-the-road recreational vehicles, military scout vehicles, and robotic emergency vehicles.

Aerodynamic Drag Reduction Apparatus For Wheeled Vehicles In Ground Effect

DOEpatents

Ortega, Jason M.; Salari, Kambiz

2005-12-13

An apparatus for reducing the aerodynamic drag of a wheeled vehicle in a flowstream, the vehicle having a vehicle body and a wheel assembly supporting the vehicle body. The apparatus includes a baffle assembly adapted to be positioned upstream of the wheel assembly for deflecting airflow away from the wheel assembly so as to reduce the incident pressure on the wheel assembly.

Procedures for One-Pass Vehicle Cone Index (VCI1) Determination for Acquisition Support

DTIC Science & Technology

2013-08-01

the VCI of tracked vehicles can be directly compared to that of wheeled vehicles; Priddy and Willoughby, 2006). Measurement of the minimum soil...of the wheel , or number of revolutions per unit time divided by 2π for a track v = forward velocity of vehicle or wheel axle. 12. Trafficability...be tested at the expected gross vehicle weight (GVW) and, for wheeled vehicles, at an appropriate soft-soil tire pressure. For wheeled vehicles

AlliedSignal driver's viewer enhancement (DVE) for paramilitary and commercial applications

NASA Astrophysics Data System (ADS)

Emanuel, Michael; Caron, Hubert; Kovacevic, Branislav; Faina-Cherkaoui, Marcela; Wrobel, Leslie; Turcotte, Gilles

1999-07-01

AlliedSignal Driver's Viewer Enhancement (DVE) system is a thermal imager using a 320 X 240 uncooled microbolometer array. This high performance system was initially developed for military combat and tactical wheeled vehicles. It features a very small sensor head remotely mounted from the display, control and processing module. The sensor head has a modular design and is being adapted to various commercial applications such as truck and car-driving aid, using specifically designed low cost optics. Tradeoffs in the system design, system features and test results are discussed in this paper. A short video shows footage of the DVE system while driving at night.

Design of a robotic vehicle with self-contained intelligent wheels

NASA Astrophysics Data System (ADS)

Poulson, Eric A.; Jacob, John S.; Gunderson, Robert W.; Abbott, Ben A.

1998-08-01

The Center for Intelligent Systems has developed a small robotic vehicle named the Advanced Rover Chassis 3 (ARC 3) with six identical intelligent wheel units attached to a payload via a passive linkage suspension system. All wheels are steerable, so the ARC 3 can move in any direction while rotating at any rate allowed by the terrain and motors. Each intelligent wheel unit contains a drive motor, steering motor, batteries, and computer. All wheel units are identical, so manufacturing, programing, and spare replacement are greatly simplified. The intelligent wheel concept would allow the number and placement of wheels on the vehicle to be changed with no changes to the control system, except to list the position of all the wheels relative to the vehicle center. The task of controlling the ARC 3 is distributed between one master computer and the wheel computers. Tasks such as controlling the steering motors and calculating the speed of each wheel relative to the vehicle speed in a corner are dependent on the location of a wheel relative to the vehicle center and ar processed by the wheel computers. Conflicts between the wheels are eliminated by computing the vehicle velocity control in the master computer. Various approaches to this distributed control problem, and various low level control methods, have been explored.

Automatic Mechetronic Wheel Light Device

DOEpatents

Khan, Mohammed John Fitzgerald

2004-09-14

A wheel lighting device for illuminating a wheel of a vehicle to increase safety and enhance aesthetics. The device produces the appearance of a "ring of light" on a vehicle's wheels as the vehicle moves. The "ring of light" can automatically change in color and/or brightness according to a vehicle's speed, acceleration, jerk, selection of transmission gears, and/or engine speed. The device provides auxiliary indicator lights by producing light in conjunction with a vehicle's turn signals, hazard lights, alarm systems, and etc. The device comprises a combination of mechanical and electronic components and can be placed on the outer or inner surface of a wheel or made integral to a wheel or wheel cover. The device can be configured for all vehicle types, and is electrically powered by a vehicle's electrical system and/or battery.

Method for surmounting an obstacle by a robot vehicle

NASA Technical Reports Server (NTRS)

Wilcox, Brian H. (Inventor); Ohm, Timothy R. (Inventor)

1994-01-01

Surmounting obstacles in the path of a robot vehicle is accomplished by rotating the wheel forks of the vehicle about their transverse axes with respect to the vehicle body so as to shift most of the vehicle weight onto the rear wheels, and then driving the vehicle forward so as to drive the now lightly-loaded front wheels (only) over the obstacle. Then, after the front wheels have either surmounted or completely passed the obstacle (depending upon the length of the obstacle), the forks are again rotated about their transverse axes so as to shift most of the vehicle weight onto the front wheels. Then the vehicle is again driven forward so as to drive the now lightly-loaded rear wheels over the obstacle. Once the obstacle has been completely cleared and the vehicle is again on relatively level terrain, the forks are again rotated so as to uniformly distribute the vehicle weight between the front and rear wheels.

Study of the Correlation between the Performances of Lunar Vehicle Wheels Predicted by the Nepean Wheeled Vehicle Performance Model and Test Data

NASA Technical Reports Server (NTRS)

Wong, J. Y.; Asnani, V. M.

2008-01-01

This paper describes the results of a study of the correlation between the performances of wheels for lunar vehicles predicted using the Nepean wheeled vehicle performance model (NWVPM), developed under the auspices of Vehicle Systems Development Corporation, Ottawa, Canada, and the corresponding test data presented in Performance evaluation of wheels for lunar vehicles , Technical Report M-70-2, prepared for George C. Marshall Space Flight Center, National Aeronautics and Space Administration (NASA), USA, by the US Army Engineer Waterways Experiment Station (WES). The NWVPM was originally developed for design and performance evaluation of terrestrial off-road wheeled vehicles. The purpose of this study is to assess the potential of the NWVPM for evaluating wheel candidates for the new generation of extra-terrestrial vehicles. Two versions of a wire-mesh wheel and a hoop-spring wheel, which were considered as candidates for lunar roving vehicles for the NASA Apollo program in the late 1960s, together with a pneumatic wheel were examined in this study. The tractive performances of these wheels and of a 464 test vehicle with the pneumatic wheels on air-dry sand were predicted using the NWVPM and compared with the corresponding test data obtained under Earth s gravity and previously documented in the above-named report. While test data on wheel or vehicle performances obtained under Earth s gravity may not necessarily be representative of those on extra-terrestrial bodies, because of the differences in gravity and in environmental conditions, such as atmospheric pressure, it is still a valid approach to use test data obtained under Earth s gravity to evaluate the predictive capability of the NWVPM and its potential applications to predicting wheel or wheeled rover performances on extra-terrestrial bodies. Results of this study show that, using the ratio (P20/W) of the drawbar pull to normal load at 20 per cent slip as a performance indicator, there is a reasonable correlation between the predictions and experimental data. This indicates that the NWVPM has the potential as an engineering tool for evaluating wheel candidates for a future generation of extra-terrestrial vehicles, provided that appropriate input data are available.

New Integrated Testing System for the Validation of Vehicle-Snow Interaction Models

DTIC Science & Technology

2010-08-06

are individual wheel speeds, accelerator pedal position, vehicle speed, yaw rate, lateral acceleration, steering wheel angle and brake ...forces and moments at each wheel center, vehicle body slip angle , speed, acceleration, yaw rate, roll, and pitch. The profilometer has a 3-D scanning...Stability Program. The test vehicle provides measurements that include three forces and moments at each wheel center, vehicle body slip angle , speed

Tactical Decision Aids High Bandwidth Links Using Autonomous Vehicles

DTIC Science & Technology

2004-01-01

1 Tactical Decision Aids (High Bandwidth Links Using Autonomous Vehicles ) A. J. Healey, D. P. Horner, Center for Autonomous Underwater Vehicle...SUBTITLE Tactical Decision Aids (High Bandwidth Links Using Autonomous Vehicles ) 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6

Improved All-Terrain Suspension System

NASA Technical Reports Server (NTRS)

Bickler, Donald B.

1994-01-01

Redesigned suspension system for all-terrain vehicle exhibits enhanced ability to negotiate sand and rocks. Improved six-wheel suspension system includes only two links on each side. Bogie tends to pull rear wheels with it as it climbs. Designed for rover vehicle for exploration of Mars, also has potential application in off-road vehicles, military scout vehicles, robotic emergency vehicles, and toys. Predecessors of suspension system described in "Articulated Suspension Without Springs" (NPO-17354), "Four-Wheel Vehicle Suspension System" (NPO-17407), and "High-Clearance Six-Wheel Suspension" (NPO-17821).

Customer loads of two-wheeled vehicles

NASA Astrophysics Data System (ADS)

Gorges, C.; Öztürk, K.; Liebich, R.

2017-12-01

Customer usage profiles are the most unknown influences in vehicle design targets and they play an important role in durability analysis. This publication presents a customer load acquisition system for two-wheeled vehicles that utilises the vehicle's onboard signals. A road slope estimator was developed to reveal the unknown slope resistance force with the help of a linear Kalman filter. Furthermore, an automated mass estimator was developed to consider the correct vehicle loading. The mass estimation is performed by an extended Kalman filter. Finally, a model-based wheel force calculation was derived, which is based on the superposition of forces calculated from measured onboard signals. The calculated wheel forces were validated by measurements with wheel-load transducers through the comparison of rainflow matrices. The calculated wheel forces correspond with the measured wheel forces in terms of both quality and quantity. The proposed methods can be used to gather field data for improved vehicle design loads.

Electronic differential control of 2WD electric vehicle considering steering stability

NASA Astrophysics Data System (ADS)

Hua, Yiding; Jiang, Haobin; Geng, Guoqing

2017-03-01

Aiming at the steering wheel differential steering control technology of rear wheel independent driving electric wheel, considering the assisting effect of electronic differential control on vehicle steering, based on the high speed steering characteristic of electric wheel car, the electronic differential speed of auxiliary wheel steering is also studied. A yaw moment control strategy is applied to the vehicle at high speed. Based on the vehicle stability reference value, yaw rate is used to design the fuzzy controller to distribute the driving wheel torque. The simulation results show that the basic electronic differential speed function is realized based on the yaw moment control strategy, while the vehicle stability control is improved and the driving safety is enhanced. On the other hand, the torque control strategy can also assist steering of vehicle.

Three dimensional modeling and dynamic analysis of four-wheel-steering vehicles

NASA Astrophysics Data System (ADS)

Hu, Haiyan; Han, Qiang

2003-02-01

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

40 CFR 86.235-94 - Dynamometer procedure.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., carbon dioxide, and oxides of nitrogen. (b) As long as an emission sample is not taken, practice runs...) Four-wheel drive vehicles will be tested in a two-wheel drive mode of operation. Full-time four-wheel drive vehicles will have one set of drive wheels temporarily disengaged by the vehicle manufacturer...

Wheeled and Tracked Vehicle Endurance Testing

DTIC Science & Technology

2014-10-02

Vehicle (ATV) 10 10 50 30 Fire Trucks - Crash and Rescue, Brush, Structural 49/56/50 22/16/50 - 29/28/0 a Wheeled Combat 30 40 15 15 Roboticb - 30 50... Wheeled Light W-M = Wheeled Medium W-H = Wheeled Heavy LM-TT = Light/Medium Truck H-TT = Heavy Truck Tractor/Trailer M = Motorcycle FT = Fire ...TYPE Final 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE Test Operations Procedure (TOP) 02-2-506A Wheeled and Tracked Vehicle Endurance

Full drive-by-wire dynamic control for four-wheel-steer all-wheel-drive vehicles

NASA Astrophysics Data System (ADS)

Fahimi, Farbod

2013-03-01

Most of the controllers introduced for four-wheel-steer (4WS) vehicles are derived with the assumption that the longitudinal speed of the vehicle is constant. However, in real applications, the longitudinal speed varies, and the longitudinal, lateral, and yaw dynamics are coupled. In this paper, the longitudinal dynamics of the vehicle as well as its lateral and yaw motions are controlled simultaneously. This way, the effect of driving/braking forces of the tires on the lateral and yaw motions of the vehicle are automatically included in the control laws. To address the dynamic parameter uncertainty of the vehicle, a chatter-free variable structure controller is introduced. Elimination of chatter is achieved by introducing a dynamically adaptive boundary layer thickness. It is shown via simulations that the proposed control approach performs more robustly than the controllers developed based on dynamic models, in which longitudinal speed is assumed to be constant, and only lateral speed and yaw rate are used as system states. Furthermore, this approach supports all-wheel-drive vehicles. Front-wheel-drive or rear-wheel-drive vehicles are also supported as special cases of an all-wheel-drive vehicle.

Steering Dynamics of Tilting Narrow Track Vehicle with Passive Front Wheel Design

NASA Astrophysics Data System (ADS)

TAN, Jeffrey Too Chuan; ARAKAWA, Hiroki; SUDA, Yoshihiro

2016-09-01

In recent years, narrow track vehicle has been emerged as a potential candidate for the next generation of urban transportation system, which is greener and space effective. Vehicle body tilting has been a symbolic characteristic of such vehicle, with the purpose to maintain its stability with the narrow track body. However, the coordination between active steering and vehicle tilting requires considerable driving skill in order to achieve effective stability. In this work, we propose an alternative steering method with a passive front wheel that mechanically follows the vehicle body tilting. The objective of this paper is to investigate the steering dynamics of the vehicle under various design parameters of the passive front wheel. Modeling of a three-wheel tilting narrow track vehicle and multibody dynamics simulations were conducted to study the effects of two important front wheel design parameters, i.e. caster angle and trail toward the vehicle steering dynamics in steering response time, turning radius, steering stability and resiliency towards external disturbance. From the results of the simulation studies, we have verified the relationships of these two front wheel design parameters toward the vehicle steering dynamics.

Mechanical Design Engineering Enabler Project wheel and wheel drives

NASA Technical Reports Server (NTRS)

Nutt, Richard E.; Couch, Britt K.; Holley, John L., Jr.; Garris, Eric S.; Staut, Paul V.

1992-01-01

Our group was assigned the responsibility of designing the wheel and wheel drive system for a proof-of-concept model of the lunar-based ENABLER. ENABLER is a multi-purpose, six wheeled vehicle designed to lift and transport heavy objects associated with the construction of a lunar base. The resulting design was based on the performance criteria of the ENABLER. The drive system was designed to enable the vehicle to achieve a speed of 7 mph on a level surface, climb a 30 percent grade, and surpass a one meter high object and one meter wide crevice. The wheel assemblies were designed to support the entire weight of the vehicle on two wheels. The wheels were designed to serve as the main component of the vehicle's suspension and will provide suitable traction for lunar-type surfaces. The expected performance of the drive system for the ENABLER was influenced by many mechanical factors. The expected top speed on a level sandy surface is 4 mph instead of the desired 7 mph. This is due to a lack of necessary power at the wheels. The lack of power resulted from dimension considerations that allowed only an eight horsepower engine and also from mechanical inefficiencies of the hydraulic system. However, the vehicle will be able to climb a 30 percent grade, surpass a one meter high object and one meter wide crevice. The wheel assemblies will be able to support the entire weight of the vehicle on two wheels. The wheels will also provide adequate suspension for the vehicle and sufficient traction for lunar-type surfaces.

Suspension Parameter Measurements of Wheeled Military Vehicles

DTIC Science & Technology

2012-08-01

suspension through the wheel pads. The SPIdER was designed so that in the future, with a modest amount of modification , it can be upgraded to include the...AND MOBILITY (P&M) MINI-SYMPOSIUM AUGUST 14-16, MICHIGAN SUSPENSION PARAMETER MEASUREMENTS OF WHEELED MILITARY VEHICLES Dale Andreatta Gary...was built to measure the suspension parameters of any military wheeled vehicle. This is part of an ongoing effort to model and predict vehicle

Joint Light Tactical Vehicle (JLTV): Background and Issues for Congress

DTIC Science & Technology

2017-01-10

Joint Light Tactical Vehicle (JLTV): Background and Issues for Congress Andrew Feickert Specialist in Military Ground Forces January 10, 2017......Congressional Research Service Summary The Joint Light Tactical Vehicle (JLTV) is being developed by the Army and the Marine Corps as a successor to the High

Development and evaluation of the Stingray, an amphibious maritime interdiction operations unmanned ground vehicle

NASA Astrophysics Data System (ADS)

Nguyen, Hoa G.; Castelli, Robin

2014-06-01

The U.S. Navy and Marine Corps conduct thousands of Maritime Interdiction Operations (MIOs) every year around the globe. Navy Visit, Board, Search, and Seizure (VBSS) teams regularly board suspect ships and perform search operations, often in hostile environments. There is a need for a small tactical robot that can be deployed ahead of the team to provide enhanced situational awareness in these boarding, breaching, and clearing operations. In 2011, the Space and Naval Warfare Systems Center Pacific conducted user evaluations on a number of small throwable robots and sensors, verified the requirements, and developed the key performance parameters (KPPs) for an MIO robot. Macro USA Corporation was then tasked to design and develop two prototype systems, each consisting of one control/display unit and two small amphibious Stingray robots. Technical challenges included the combination paddle wheel/shock-absorbing wheel, the tradeoff between impact resistance, size, and buoyancy, and achieving adequate traction on wet surfaces. This paper describes the technical design of these robots and the results of subsequent user evaluations by VBSS teams.

Integration of uniform design and quantum-behaved particle swarm optimization to the robust design for a railway vehicle suspension system under different wheel conicities and wheel rolling radii

NASA Astrophysics Data System (ADS)

Cheng, Yung-Chang; Lee, Cheng-Kang

2017-10-01

This paper proposes a systematic method, integrating the uniform design (UD) of experiments and quantum-behaved particle swarm optimization (QPSO), to solve the problem of a robust design for a railway vehicle suspension system. Based on the new nonlinear creep model derived from combining Hertz contact theory, Kalker's linear theory and a heuristic nonlinear creep model, the modeling and dynamic analysis of a 24 degree-of-freedom railway vehicle system were investigated. The Lyapunov indirect method was used to examine the effects of suspension parameters, wheel conicities and wheel rolling radii on critical hunting speeds. Generally, the critical hunting speeds of a vehicle system resulting from worn wheels with different wheel rolling radii are lower than those of a vehicle system having original wheels without different wheel rolling radii. Because of worn wheels, the critical hunting speed of a running railway vehicle substantially declines over the long term. For safety reasons, it is necessary to design the suspension system parameters to increase the robustness of the system and decrease the sensitive of wheel noises. By applying UD and QPSO, the nominal-the-best signal-to-noise ratio of the system was increased from -48.17 to -34.05 dB. The rate of improvement was 29.31%. This study has demonstrated that the integration of UD and QPSO can successfully reveal the optimal solution of suspension parameters for solving the robust design problem of a railway vehicle suspension system.

Errors of car wheels rotation rate measurement using roller follower on test benches

NASA Astrophysics Data System (ADS)

Potapov, A. S.; Svirbutovich, O. A.; Krivtsov, S. N.

2018-03-01

The article deals with rotation rate measurement errors, which depend on the motor vehicle rate, on the roller, test benches. Monitoring of the vehicle performance under operating conditions is performed on roller test benches. Roller test benches are not flawless. They have some drawbacks affecting the accuracy of vehicle performance monitoring. Increase in basic velocity of the vehicle requires increase in accuracy of wheel rotation rate monitoring. It determines the degree of accuracy of mode identification for a wheel of the tested vehicle. To ensure measurement accuracy for rotation velocity of rollers is not an issue. The problem arises when measuring rotation velocity of a car wheel. The higher the rotation velocity of the wheel is, the lower the accuracy of measurement is. At present, wheel rotation frequency monitoring on roller test benches is carried out by following-up systems. Their sensors are rollers following wheel rotation. The rollers of the system are not kinematically linked to supporting rollers of the test bench. The roller follower is forced against the wheels of the tested vehicle by means of a spring-lever mechanism. Experience of the test bench equipment operation has shown that measurement accuracy is satisfactory at small rates of vehicles diagnosed on roller test benches. With a rising diagnostics rate, rotation velocity measurement errors occur in both braking and pulling modes because a roller spins about a tire tread. The paper shows oscillograms of changes in wheel rotation velocity and rotation velocity measurement system’s signals when testing a vehicle on roller test benches at specified rates.

Vehicle Characteristics

DTIC Science & Technology

2008-02-14

g. Material. 5.1.7 Wheel Geometry. a. Camber angle. b. Caster angle. c. Pivot angle. d. Static toe-in. e. Turning angles...the vehicle characteristics to be obtained during testing of wheeled and tracked vehicles and their components. Physical characterization of test...frontal area Characteristic data sheet Power train Suspention Wheel geometry Vehicle clearance angles Armament Gun control systems 16. SECURITY

Position and force control of a vehicle with two or more steerable drive wheels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reister, D.B.; Unseren, M.A.

1992-10-01

When a vehicle with two or more steerable drive wheels is traveling in a circle, the motion of the wheels is constrained. The wheel translational velocity divided by the radius to the center of rotation must be the same for all wheels. When the drive wheels are controlled independently using position control, the motion of the wheels may violate the constraints and the wheels may slip. Consequently, substantial errors can occur in the orientation of the vehicle. A vehicle with N drive wheels has (N - 1) constraints and one degree of freedom. We have developed a new approach tomore » the control of a vehicle with N steerable drive wheels. The novel aspect of our approach is the use of force control. To control the vehicle, we have one degree of freedom for the position on the circle and (N - 1) forces that can be used to reduce errors. Recently, Kankaanranta and Koivo developed a control architecture that allows the force and position degrees of freedom to be decoupled. In the work of Kankaanranta and Koivo the force is an exogenous input. We have made the force endogenous by defining the force in terms of the errors in satisfying the rigid body kinematic constraints. We have applied the control architecture to the HERMIES-III robot and have measured a dramatic reduction in error (more than a factor of 20) compared to motions without force control.« less

Modelling, validation and analysis of a three-dimensional railway vehicle-track system model with linear and nonlinear track properties in the presence of wheel flats

NASA Astrophysics Data System (ADS)

Uzzal, R. U. A.; Ahmed, A. K. W.; Bhat, R. B.

2013-11-01

This paper presents dynamic contact loads at wheel-rail contact point in a three-dimensional railway vehicle-track model as well as dynamic response at vehicle-track component levels in the presence of wheel flats. The 17-degrees of freedom lumped mass vehicle is modelled as a full car body, two bogies and four wheelsets, whereas the railway track is modelled as two parallel Timoshenko beams periodically supported by lumped masses representing the sleepers. The rail beam is also supported by nonlinear spring and damper elements representing the railpad and ballast. In order to ensure the interactions between the railpads, a shear parameter beneath the rail beams has also been considered into the model. The wheel-rail contact is modelled using nonlinear Hertzian contact theory. In order to solve the coupled partial and ordinary differential equations of the vehicle-track system, modal analysis method is employed. Idealised Haversine wheel flats with the rounded corner are included in the wheel-rail contact model. The developed model is validated with the existing measured and analytical data available in the literature. The nonlinear model is then employed to investigate the wheel-rail impact forces that arise in the wheel-rail interface due to the presence of wheel flats. The validated model is further employed to investigate the dynamic responses of vehicle and track components in terms of displacement, velocity, and acceleration in the presence of single wheel flat.

Analysis of Flexible Car Body of Straddle Monorail Vehicle

NASA Astrophysics Data System (ADS)

Zhong, Yuanmu

2018-03-01

Based on the finite element model of straddle monorail vehicle, a rigid-flexible coupling dynamic model considering vehicle body’s flexibility is established. The influence of vertical stiffness and vertical damping of the running wheel on the modal parameters of the car body is analyzed. The effect of flexible car body on modal parameters and vehicle ride quality is also studied. The results show that when the vertical stiffness of running wheel is less than 1 MN / m, the car body bounce and pitch frequency increase with the increasing of the vertical stiffness of the running wheel, when the running wheel vertical stiffness is 1MN / m or more, car body bounce and pitch frequency remained unchanged; When the vertical stiffness of the running wheel is below 1.8 MN / m, the vehicle body bounce and pitch damping ratio increase with the increasing of the vertical stiffness of the running wheel; When the running wheel vertical stiffness is 1.8MN / m or more, the car body bounce and pitch damping ratio remained unchanged; The running wheel vertical damping on the car body bounce and pitch frequency has no effect; Car body bounce and pitch damping ratio increase with the increasing of the vertical damping of the running wheel. The flexibility of the car body has no effect on the modal parameters of the car, which will improve the vehicle ride quality index.

Vehicle Dynamics Control of In-wheel Electric Motor Drive Vehicles Based on Averaging of Tire Force Usage

NASA Astrophysics Data System (ADS)

Masaki, Nobuo; Iwano, Haruo; Kamada, Takayoshi; Nagai, Masao

For in-wheel electric motor drive vehicles, a new vehicle dynamics control which is based on the tire force usage rate is proposed. The new controller adopts non-linear optimal control could manage the interference between direct yaw-moment control and the tire force usage rate. The new control is considered total longitudinal and transverse tire force. Therefore the controller can prevent tire force saturation near tire force limit during cornering. Simulations and test runs by the custom made four wheel drive in-wheel motor electric vehicle show that higher driving stability performance compared to the performance of the same vehicle without control.

Considerations on the use of elastic wheels to the urban transport vehicles

NASA Astrophysics Data System (ADS)

Sebesan, Ioan; Arsene, Sorin; Manea, Ion

2018-03-01

To minimize dynamic wheel-rail interaction efforts a condition is that the unassembled mass of the vehicle is as small as possible. The elastic wheel by its construction fulfills these conditions - she has interposed between the crown and the body of the wheel, the elastic rubber elements. In this way, it can be considered that the unsupported mass is represented only by the mass of the wheel crown. Additionally, this elasticity also has a reduction effect on rolling noise. This feature makes it suitable for use on urban transport vehicles.

Risk of Motor Vehicle Accidents Related to Sleepiness at the Wheel: A Systematic Review and Meta-Analysis.

PubMed

Bioulac, Stéphanie; Franchi, Jean-Arthur Micoulaud; Arnaud, Mickael; Sagaspe, Patricia; Moore, Nicholas; Salvo, Francesco; Philip, Pierre

2017-10-01

Sleepiness at the wheel is widely believed to be a cause of motor vehicle accidents. Nevertheless, a systematic review of studies investigating this relationship has not yet been published. The objective of this study was to quantify the relationship between sleepiness at the wheel and motor vehicle accidents. A systematic review was performed using Medline, Scopus, and ISI Web of Science. The outcome measure of interest was motor vehicle accident defined as involving four- or two-wheeled vehicles in road traffic, professional and nonprofessional drivers, with or without objective consequences. The exposure was sleepiness at the wheel defined as self-reported sleepiness at the wheel. Studies were included if they provided adjusted risk estimates of motor vehicle accidents related to sleepiness at the wheel. Risk estimates and 95% confidence intervals (95% CIs) were extracted and pooled as odds ratios (ORs) using a random-effect model. Heterogeneity was quantified using Q statistics and the I2 index. The potential causes of heterogeneity were investigated using meta-regressions. Ten cross-sectional studies (51,520 participants), six case-control studies (4904 participants), and one cohort study (13,674 participants) were included. Sleepiness at the wheel was associated with an increased risk of motor vehicle accidents (pooled OR 2.51 [95% CI 1.87; 3.39]). A significant heterogeneity was found between the individual risk estimates (Q = 93.21; I2 = 83%). Sleepiness at the wheel increases the risk of motor vehicle accidents and should be considered when investigating fitness to drive. Further studies are required to explore the nature of this relationship. PROSPERO 2015 CRD42015024805. © Sleep Research Society 2017. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

On the overriding issue of train front end collision in rail vehicle dynamics

NASA Astrophysics Data System (ADS)

Yang, Chao; Li, Qiang; Xiao, Shoune; Wang, Xi

2018-04-01

A three-dimensional dynamic model of crashed vehicles coupled with moving tracks is developed to research the dynamic behaviour of the train front end collision on tangent tracks. The three-dimensional dynamic model consists of a crashed vehicle model, moving track models, a simple wheel-rail contact model, a velocity-based coupler model and the model of energy absorption and anti-climbing devices. The vector method dealing with the nonlinear wheel-rail geometry is put forward in the paper. The developed model is applicable in the scope that central collisions occur on tangent tracks at low speeds. The examples of the vehicle impacting with a rigid wall and the train front end collision are carried out to obtain the dynamic responses of vehicles. The overriding issue is studied on the basis of the wheel rise in train collisions. The results show that the second bogie of the first colliding vehicle possesses the maximal wheel rise. The wheel rise increases with the increase of vehicles. However, the number of vehicles has tiny influence on the overriding in train collisions at low speeds. On the contrary, the impact speed has significant influence on the overriding in train collisions. The wheel rise increases rapidly if the impact speed is close to the critical speed of overriding. The large wheel rise is principally generated by the great coupler force related to the rigid impact in the axial direction.

The CRREL Instrumented Vehicle: Hardware and Software.

DTIC Science & Technology

1983-01-01

rear axle torque are meas- ured. The vehicle is equipped for front-wheel, rear-wheel or four-wheel drive. A dual brake system allows front-, rear- or...four-wheel braking . A minicomputer- based data acquisition system is installed in the vehicle to control data gather ing and to process the data. The...o..o...o 4 4. Dual brake system control valves . ........ 5 5. Schematic of modified brake system ...... .... st 5 6. Air-shock-absorber regulator

Wheeled Vehicle Electrical Systems. Military Curriculum Materials for Vocational and Technical Education.

ERIC Educational Resources Information Center

Army Ordnance Center and School, Aberdeen Proving Ground, MD.

This course is one of several subcourses that make up the entire Army correspondence course on wheeled vehicle maintenance. The subcourse is designed to provide the student with information about the operation, malfunction diagnosis, maintenance, and repair of wheeled vehicle electrical systems. It provides the basic theory, and also includes…

Slip control design of electric vehicle using indirect Dahlin Adaptive Pid

NASA Astrophysics Data System (ADS)

Fauzi, I. R.; Koko, F.; Kirom, M. R.

2016-11-01

In this paper the problem to be solved is to build a slip control on a wheel that may occur in an electric car wheel. Slip is the difference in vehicle velocity and wheel tangential velocity and to be enlarged when the torque given growing. Slip can be reduced by controlling the torque of the wheel so that the wheel tangential speed does not exceed the vehicle speed. The experiment in this paper is a simulation using MATLAB Simulink and using Adaptive control. The response adaptive PID control more quickly 1.5 s than PID control and can controlled wheel tangential speed close to the vehicle velocity on a dry asphalt, wet asphalt, snow and ice surface sequent at time 2s, 4s, 10s, and 50s. The maximum acceleration of the vehicle (V) on the surface of the dry asphalt, wet asphalt, snow, and ice surface sequent at 8.9 m/s2, 6.2 m/s2, 2.75 m/s2, and 0.34 m/s2.

The development of an assessment tool for the mobility of lightweight autonomous vehicles on coastal terrain

NASA Astrophysics Data System (ADS)

Worley, Marilyn E.; Ren, Ping; Sandu, Corina; Hong, Dennis

2007-04-01

This study focuses on developing an assessment tool for the performance prediction of lightweight autonomous vehicles with varying locomotion platforms on coastal terrain involves three segments. A table based on the House of Quality shows the relationships - high, low, or adverse - between mission profile requirements and general performance measures and geometries of vehicles under consideration for use. This table, when combined with known values for vehicle metrics, provides information for an index formula used to quantitatively compare the mobility of a user-chosen set of vehicles, regardless of their methods of locomotion. To study novel forms of locomotion, and to compare their mobility and performance with more traditional wheeled and tracked vehicles, several new autonomous vehicles - bipedal, self-excited dynamic tripedal, active spoke-wheel - are currently under development. While the terramechanics properties of wheeled and tracked vehicles, such as the contact patch pressure distribution, have been understood and models have been developed for heavy vehicles, the feasibility of extrapolating them to the analysis of light vehicles is still under analysis. wheeled all-terrain vehicle and a lightweight autonomous tracked vehicle have been tested for effects of sand gradation, vehicle speed, and vehicle payload on measures of pressure and sinkage in the contact patch, and preliminary analysis is presented on the sinkage of the wheeled all-terrain vehicle. These three segments - development of the comparison matrix and indexing function, modeling and development of novel forms of locomotion, and physical experimentation of lightweight tracked and wheeled vehicles on varying terrain types for terramechanic model validation - combine to give an overall picture of mobility that spans across different forms of locomotion.

On-Line Path Generation and Tracking for High-Speed Wheeled Autonomous Vehicles

DTIC Science & Technology

2006-02-17

On-Line Path Generation and Tracking for High-Speed Wheeled Autonomous Vehicles Report Title ABSTRACT In this work we proposed two semi-analytic...298-102 Enclosure 1 On-Line Path Generation and Tracking for High-Speed Wheeled Autonomous Vehicles by...Specifically, the following problems will be addressed during this project: 2.1 Challenges The problem of trajectory planning for high-speed autonomous vehicles is

Tactical Satellite-3 Mission Overview and Initial Lessons Learned (Postprint)

DTIC Science & Technology

2013-03-01

current buses. The spacecraft bus includes the main structure; attitude control system (reaction wheels and torque rods); the thermal protection...Specific key areas are the relatively rapid checkout of the spacecraft and lessons from the responsive space development. 15. SUBJECT TERMS...relatively rapid checkout of the spacecraft and lessons from the responsive space development. INTRODUCTION The Tactical Satellite 3 mission was a

Analysis of heat conduction in a drum brake system of the wheeled armored personnel carriers

NASA Astrophysics Data System (ADS)

Puncioiu, A. M.; Truta, M.; Vedinas, I.; Marinescu, M.; Vinturis, V.

2015-11-01

This paper is an integrated study performed over the Braking System of the Wheeled Armored Personnel Carriers. It mainly aims to analyze the heat transfer process which is present in almost any industrial and natural process. The vehicle drum brake systems can generate extremely high temperatures under high but short duration braking loads or under relatively light but continuous braking. For the proper conduct of the special vehicles mission in rough terrain, we are talking about, on one hand, the importance of the possibility of immobilization and retaining position and, on the other hand, during the braking process, the importance movement stability and reversibility or reversibility, to an encounter with an obstacle. Heat transfer processes influence the performance of the braking system. In the braking phase, kinetic energy transforms into thermal energy resulting in intense heating and high temperature states of analyzed vehicle wheels. In the present work a finite element model for the temperature distribution in a brake drum is developed, by employing commercial finite element software, ANSYS. These structural and thermal FEA models will simulate entire braking event. The heat generated during braking causes distortion which modifies thermoelastic contact pressure distribution drum-shoe interface. In order to capture the effect of heat, a transient thermal analysis is performed in order to predict the temperature distribution transitional brake components. Drum brakes are checked both mechanical and thermal. These tests aim to establish their sustainability in terms of wear and the variation coefficient of friction between the friction surfaces with increasing temperature. Modeling using simulation programs led eventually to the establishment of actual thermal load of the mechanism of brake components. It was drawn the efficiency characteristic by plotting the coefficient of effectiveness relative to the coefficient of friction shoe-drum. Thus induced thermal loads determine thermo mechanical behavior of the structure of wheels. Study the transfer of heat generated during braking is useful because results can improve and validate existing theory or may lead to the development of a mathematical model to simulate the behavior of the brake system for various tactical and operational situations. Conclusions of this paper are relevant because theoretical data analysis results are validated by experimental research.

Wheeled Vehicle Drive Lines, Axles, and Suspension Systems. Military Curriculum Materials for Vocational and Technical Education.

ERIC Educational Resources Information Center

Army Ordnance Center and School, Aberdeen Proving Ground, MD.

This course is one of several subcourses that make up the entire Army correspondence course on wheeled vehicle maintenance. The subcourse is designed to provide the student with information about the operation, malfunction diagnosis, maintenance, and repair of wheeled vehicle drive lines, axles, and suspension systems. It provides the basic…

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reister, D.B.; Unseren, M.A.

When a vehicle with two or more steerable drive wheels is traveling in a circle, the motion of the wheels is constrained. The wheel translational velocity divided by the radius to the center of rotation must be the same for all wheels. When the drive wheels are controlled independently using position control, the motion of the wheels may violate the constraints and the wheels may slip. Consequently, substantial errors can occur in the orientation of the vehicle. A vehicle with N drive wheels has (N - 1) constraints and one degree of freedom. We have developed a new approach tomore » the control of a vehicle with N steerable drive wheels. The novel aspect of our approach is the use of force control. To control the vehicle, we have one degree of freedom for the position on the circle and (N - 1) forces that can be used to reduce errors. Recently, Kankaanranta and Koivo developed a control architecture that allows the force and position degrees of freedom to be decoupled. In the work of Kankaanranta and Koivo the force is an exogenous input. We have made the force endogenous by defining the force in terms of the errors in satisfying the rigid body kinematic constraints. We have applied the control architecture to the HERMIES-III robot and have measured a dramatic reduction in error (more than a factor of 20) compared to motions without force control.« less

Development and performance characterization of an electric ground vehicle with independently actuated in-wheel motors

NASA Astrophysics Data System (ADS)

Wang, Rongrong; Chen, Yan; Feng, Daiwei; Huang, Xiaoyu; Wang, Junmin

This paper presents the development and experimental characterizations of a prototyping pure electric ground vehicle, which is equipped with four independently actuated in-wheel motors (FIAIWM) and is powered by a 72 V 200 Ah LiFeYPO 4 battery pack. Such an electric ground vehicle (EGV) employs four in-wheel (or hub) motors to independently drive/brake the four wheels and is one of the promising vehicle architectures primarily due to its actuation flexibility, energy efficiency, and performance potentials. Experimental data obtained from the EGV chassis dynamometer tests were employed to generate the in-wheel motor torque response and power efficiency maps in both driving and regenerative braking modes. A torque distribution method is proposed to show the potentials of optimizing the FIAIWM EGV operational energy efficiency by utilizing the actuation flexibility and the characterized in-wheel motor efficiency and torque response.

Followup Audit: DLA Officials Took Appropriate Actions to Address Concerns With Repair Parts for the High Mobility Multipurpose Wheeled Vehicle

DTIC Science & Technology

2016-04-29

Followup Audit : DLA Officials Took Appropriate Actions to Address Concerns With Repair Parts for the High Mobility Multipurpose Wheeled Vehicle A P R I L...Results in Brief Followup Audit : DLA Officials Took Appropriate Actions to Address Concerns With Repair Parts for the High Mobility Multipurpose Wheeled...and Maritime Paid Too Much for High Mobility Multipurpose Wheeled Vehicle Repair Parts,” (HMMWV) was issued on April 4, 2014. The audit

Estimators of wheel slip for electric vehicles using torque and encoder measurements

NASA Astrophysics Data System (ADS)

Boisvert, M.; Micheau, P.

2016-08-01

For the purpose of regenerative braking control in hybrid and electrical vehicles, recent studies have suggested controlling the slip ratio of the electric-powered wheel. A slip tracking controller requires an accurate slip estimation in the overall range of the slip ratio (from 0 to 1), contrary to the conventional slip limiter (ABS) which calls for an accurate slip estimation in the critical slip area, estimated at around 0.15 in several applications. Considering that it is not possible to directly measure the slip ratio of a wheel, the problem is to estimate the latter from available online data. To estimate the slip of a wheel, both wheel speed and vehicle speed must be known. Several studies provide algorithms that allow obtaining a good estimation of vehicle speed. On the other hand, there is no proposed algorithm for the conditioning of the wheel speed measurement. Indeed, the noise included in the wheel speed measurement reduces the accuracy of the slip estimation, a disturbance increasingly significant at low speed and low torque. Herein, two different extended Kalman observers of slip ratio were developed. The first calculates the slip ratio with data provided by an observer of vehicle speed and of propeller wheel speed. The second observer uses an original nonlinear model of the slip ratio as a function of the electric motor. A sinus tracking algorithm is included in the two observers, in order to reject harmonic disturbances of wheel speed measurement. Moreover, mass and road uncertainties can be compensated with a coefficient adapted online by an RLS. The algorithms were implemented and tested with a three-wheel recreational hybrid vehicle. Experimental results show the efficiency of both methods.

A mechanical model for deformable and mesh pattern wheel of lunar roving vehicle

NASA Astrophysics Data System (ADS)

Liang, Zhongchao; Wang, Yongfu; Chen, Gang (Sheng); Gao, Haibo

2015-12-01

As an indispensable tool for astronauts on lunar surface, the lunar roving vehicle (LRV) is of great significance for manned lunar exploration. An LRV moves on loose and soft lunar soil, so the mechanical property of its wheels directly affects the mobility performance. The wheels used for LRV have deformable and mesh pattern, therefore, the existing mechanical theory of vehicle wheel cannot be used directly for analyzing the property of LRV wheels. In this paper, a new mechanical model for LRV wheel is proposed. At first, a mechanical model for a rigid normal wheel is presented, which involves in multiple conventional parameters such as vertical load, tangential traction force, lateral force, and slip ratio. Secondly, six equivalent coefficients are introduced to amend the rigid normal wheel model to fit for the wheels with deformable and mesh-pattern in LRV application. Thirdly, the values of the six equivalent coefficients are identified by using experimental data obtained in an LRV's single wheel testing. Finally, the identified mechanical model for LRV's wheel with deformable and mesh pattern are further verified and validated by using additional experimental results.

Modelling of a mecanum wheel taking into account the geometry of road rollers

NASA Astrophysics Data System (ADS)

Hryniewicz, P.; Gwiazda, A.; Banaś, W.; Sękala, A.; Foit, K.

2017-08-01

During the process planning in a company one of the basic factors associated with the production costs is the operation time for particular technological jobs. The operation time consists of time units associated with the machining tasks of a workpiece as well as the time associated with loading and unloading and the transport operations of this workpiece between machining stands. Full automation of manufacturing in industry companies tends to a maximal reduction in machine downtimes, thereby the fixed costs simultaneously decreasing. The new construction of wheeled vehicles, using Mecanum wheels, reduces the transport time of materials and workpieces between machining stands. These vehicles have the ability to simultaneously move in two axes and thus more rapid positioning of the vehicle relative to the machining stand. The Mecanum wheel construction implies placing, around the wheel free rollers that are mounted at an angle 450, which allow the movement of the vehicle not only in its axis but also perpendicular thereto. The improper selection of the rollers can cause unwanted vertical movement of the vehicle, which may cause difficulty in positioning of the vehicle in relation to the machining stand and the need for stabilisation. Hence the proper design of the free rollers is essential in designing the whole Mecanum wheel construction. It allows avoiding the disadvantageous and unwanted vertical vibrations of a whole vehicle with these wheels. In the article the process of modelling the free rollers, in order to obtain the desired shape of unchanging, horizontal trajectory of the vehicle is presented. This shape depends on the desired diameter of the whole Mecanum wheel, together with the road rollers, and the width of the drive wheel. Another factor related with the curvature of the trajectory shape is the length of the road roller and its diameter decreases depending on the position with respect to its centre. The additional factor, limiting construction of the road rollers, is their bearings. Depending on the load, carried by the vehicle and the rotational speed of the drive wheel, the bearings themselves can greatly affect the diameter of the rollers and the whole Mecanum wheels. The solution of this problem is presented in the paper. It is illustrated with virtual models elaborated in advanced program of the CAE class.

Wheel climb derailment criteria for evaluation of rail vehicle safety

DOT National Transportation Integrated Search

1984-01-01

Criteria for evaluating safety of rail vehicles with respect to wheel climb derailment are reviewed. The relationship between flanging wheel lateral to veritical force ratio at impending derailment and angle of attack, lateral velocity and longitudin...

Two speed drive system. [mechanical device for changing speed on rotating vehicle wheel

NASA Technical Reports Server (NTRS)

Burch, J. L. (Inventor)

1972-01-01

A two speed drive system for a wheel of a vehicle by which shifting from one speed to the other is accomplished by the inherent mechanism of the wheel is described. A description of the speed shifting operation is provided and diagrams of the mechanism are included. Possible application to lunar roving vehicles is proposed.

Influence of polygonal wear of railway wheels on the wheel set axle stress

NASA Astrophysics Data System (ADS)

Wu, Xingwen; Chi, Maoru; Wu, Pingbo

2015-11-01

The coupled vehicle/track dynamic model with the flexible wheel set was developed to investigate the effects of polygonal wear on the dynamic stresses of the wheel set axle. In the model, the railway vehicle was modelled by the rigid multibody dynamics. The wheel set was established by the finite element method to analyse the high-frequency oscillation and dynamic stress of wheel set axle induced by the polygonal wear based on the modal stress recovery method. The slab track model was taken into account in which the rail was described by the Timoshenko beam and the three-dimensional solid finite element was employed to establish the concrete slab. Furthermore, the modal superposition method was adopted to calculate the dynamic response of the track. The wheel/rail normal forces and the tangent forces were, respectively, determined by the Hertz nonlinear contact theory and the Shen-Hedrick-Elkins model. Using the coupled vehicle/track dynamic model, the dynamic stresses of wheel set axle with consideration of the ideal polygonal wear and measured polygonal wear were investigated. The results show that the amplitude of wheel/rail normal forces and the dynamic stress of wheel set axle increase as the vehicle speeds rise. Moreover, the impact loads induced by the polygonal wear could excite the resonance of wheel set axle. In the resonance region, the amplitude of the dynamic stress for the wheel set axle would increase considerably comparing with the normal conditions.

Control system for maximum use of adhesive forces of a railway vehicle in a tractive mode

NASA Astrophysics Data System (ADS)

Spiryagin, Maksym; Lee, Kwan Soo; Yoo, Hong Hee

2008-04-01

The realization of maximum adhesive forces for a railway vehicle is a very difficult process, because it involves using tractive efforts and depends on friction characteristics in the contact zone between wheels and rails. Tractive efforts are realized by means of tractive torques of motors, and their maximum values can provide negative effects such as slip and skid. These situations usually happen when information about friction conditions is lacking. The negative processes have a major influence on wearing of contact bodies and tractive units. Therefore, many existing control systems for vehicles use an effect of a prediction of a friction coefficient between wheels and rails because measuring a friction coefficient at the moment of running vehicle movement is very difficult. One of the ways to solve this task is to use noise spectrum analysis for friction coefficient detection. This noise phenomenon has not been clearly studied and analyzed. In this paper, we propose an adhesion control system of railway vehicles based on an observer, which allows one to determine the maximum tractive torque based on the optimal adhesive force between the wheels (wheel pair) of a railway vehicle and rails (rail track) depending on weight load from a wheel to a rail, friction conditions in the contact zone, a lateral displacement of wheel set and wheel sleep. As a result, it allows a railway vehicle to be driven in a tractive mode by the maximum adhesion force for real friction conditions.

Efficiency analysis of a multiple axle vehicle with hydrostatic transmission overcoming obstacles

NASA Astrophysics Data System (ADS)

Comellas, M.; Pijuan, J.; Nogués, M.; Roca, J.

2018-01-01

Transmission configurations in off-road vehicles with multiple driven axles can be a determining factor in the obstacle surmounting capacity and also in the vehicle efficiency. An off-road articulated vehicle with four driven axles, four bogies and two modules has been considered for the global hydrostatic transmission efficiency analysis and for the vehicle functional efficiency analysis. The power flow through the transmission system has been quantified from the combustion engine shaft to each axle of the wheels. It has been done for different the operating conditions and taking into account the wheel-terrain interaction and the transmission configuration, that could lead to a forced slippage of some of the wheels. Results show the influence of the different wheels' requirements, the transmission configuration limitations and the considered control strategy on the global transmission and vehicle functional efficiencies.

Four-Wheel Vehicle Suspension System

NASA Technical Reports Server (NTRS)

Bickler, Donald B.

1990-01-01

Four-wheel suspension system uses simple system of levers with no compliant components to provide three-point suspension of chassis of vehicle while maintaining four-point contact with uneven terrain. Provides stability against tipping of four-point rectangular base, without rocking contact to which rigid four-wheel frame susceptible. Similar to six-wheel suspension system described in "Articulated Suspension Without Springs" (NPO-17354).

Injuries to Occupants of U.S. Army High Mobility Multipurpose Wheeled Vehicles in Rollover Accidents, 1989-2007

DTIC Science & Technology

2013-04-02

This research conducted on occupant injuries in U.S. Army High Mobility Multipurpose Wheeled Vehicle (HMMWV) rollover accidents was presented at the ...12  1 Introduction The High Mobility Multipurpose Wheeled Vehicle (HMMWV) is...Soldiers may experience the full impact of jarring forces and/or projectile forces of unrestrained equipment. Rollovers are especially hazardous to

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

ERIC Educational Resources Information Center

Tavares, J. M.

2009-01-01

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

Global Versus Reactive Navigation for Joint UAV-UGV Missions in a Cluttered Environment

DTIC Science & Technology

2012-06-01

spaces. The vehicle uses a two- wheel 5 differential drive system with a third omnidirectional caster for balance. This uncomplicated system saves... wheels , two differential drive wheels and one omni- directional caster wheel . The vehicle changes the direction of its movement by altering the speed of...Virtual Speed Versus Time..........64  Figure 23:  Heading and Yaw Rate Versus Time................64  Figure 24:  Individual Wheel Speeds Versus Time

Prediction Study on Anti-Slide Control of Railway Vehicle Based on RBF Neural Networks

NASA Astrophysics Data System (ADS)

Yang, Lijun; Zhang, Jimin

While railway vehicle braking, Anti-slide control system will detect operating status of each wheel-sets e.g. speed difference and deceleration etc. Once the detected value on some wheel-set is over pre-defined threshold, brake effort on such wheel-set will be adjusted automatically to avoid blocking. Such method takes effect on guarantee safety operation of vehicle and avoid wheel-set flatness, however it cannot adapt itself to the rail adhesion variation. While wheel-sets slide, the operating status is chaotic time series with certain law, and can be predicted with the law and experiment data in certain time. The predicted values can be used as the input reference signals of vehicle anti-slide control system, to judge and control the slide status of wheel-sets. In this article, the RBF neural networks is taken to predict wheel-set slide status in multi-step with weight vector adjusted based on online self-adaptive algorithm, and the center & normalizing parameters of active function of the hidden unit of RBF neural networks' hidden layer computed with K-means clustering algorithm. With multi-step prediction simulation, the predicted signal with appropriate precision can be used by anti-slide system to trace actively and adjust wheel-set slide tendency, so as to adapt to wheel-rail adhesion variation and reduce the risk of wheel-set blocking.

Compliant-linkage kinematic design for multi-degree-of-freedom mobile robots

NASA Astrophysics Data System (ADS)

Borenstein, Johann

1993-05-01

Multi-degree-of-freedom (MDOF) vehicles have many potential advantages over conventional (i.e., 2-DOF) vehicles. For example, MDOF vehicles can travel sideways and they can negotiate tight turns more easily. In addition, some MDOF designs provide better payload capability, better traction, and improved static and dynamic stability. However, MDOF vehicles with more than three degrees-of-freedom are difficult to control because of their overconstrained nature. These difficulties translate into severe wheel slippage or jerky motion under certain driving conditions. In the past, these problems limited the use of MDOF vehicles to applications where the vehicle would follow a guide-wire, which would correct wheel slippage and control errors. By contrast, autonomous or semi-autonomous mobile robots usually rely on dead-reckoning between periodic absolute position updates and their performance is diminished by excessive wheel slippage. This paper introduces a new concept in the kinematic design of MDOF vehicles. This concept is based on the provision of a compliant linkage between drive wheels or drive axles. Simulation results indicate that compliant linkage allows to overcome the control problems found in conventional MDOF vehicles and reduces the amount of wheel slippage to the same level (or less) than the amount of slippage found on a comparable 2-DOF vehicle.

Motion resistance of wheeled vehicles in snow

DOT National Transportation Integrated Search

1995-03-01

This report examines several aspects of wheeled vehicle motion resistance using results obtained with the CRREL instrumented vehicle. Resistances of leading and trailing tires are examined. Limited data are presented for undercarriage drag, and third...

Eco-driving : strategic, tactical, and operational decisions of the driver that improve vehicle fuel economy.

DOT National Transportation Integrated Search

2011-08-01

"This report presents information about the effects of decisions that a driver can make to : influence on-road fuel economy of light-duty vehicles. These include strategic decisions : (vehicle selection and maintenance), tactical decisions (route sel...

ATHLETE: A Limbed Vehicle for Solar System Exploration

NASA Technical Reports Server (NTRS)

Wilcox, Brian H.

2012-01-01

As part of the Human-Robot Systems project funded by NASA, the Jet Propulsion Laboratory has developed a vehicle called ATHLETE: the All-Terrain Hex-Limbed Extra-Terrestrial Explorer. Each vehicle is based on six wheels at the ends of six multi-degree-of-freedom limbs. Because each limb has enough degrees of freedom for use as a general-purpose leg, the wheels can be locked and used as feet to walk out of excessively soft or other extreme terrain. Since the vehicle has this alternative mode of traversing through or at least out of extreme terrain, the wheels and wheel actuators can be sized for nominal terrain. There are substantial mass savings in the wheel and wheel actuators associated with designing for nominal instead of extreme terrain. These mass savings are comparable-to or larger-than the extra mass associated with the articulated limbs. As a result, the entire mobility system, including wheels and limbs, can be about 25% lighter than a conventional mobility chassis. A side benefit of this approach is that each limb has sufficient degrees-of-freedom to use as a general-purpose manipulator (hence the name "limb" instead of "leg"). Our prototype ATHLETE vehicles have quick-disconnect tool adapters on the limbs that allow tools to be drawn out of a "tool belt" and maneuvered by the limb.

Design of driving control strategy of torque distribution for two - wheel independent drive electric vehicle

NASA Astrophysics Data System (ADS)

Zhang, Chuanwei; Zhang, Dongsheng; Wen, Jianping

2018-02-01

In order to coordinately control the torque distribution of existing two-wheel independent drive electric vehicle, and improve the energy efficiency and control stability of the whole vehicle, the control strategies based on fuzzy control were designed which adopt the direct yaw moment control as the main line. For realizing the torque coordination simulation of the two-wheel independent drive vehicle, the vehicle model, motor model and tire model were built, including the vehicle 7 - DOF dynamics model, motion equation, torque equation. Finally, in the Carsim - Simulink joint simulation platform, the feasibility of the drive control strategy was verified.

Vehicle underbody fairing

DOEpatents

Ortega, Jason M.; Salari, Kambiz; McCallen, Rose

2010-11-09

A vehicle underbody fairing apparatus for reducing aerodynamic drag caused by a vehicle wheel assembly, by reducing the size of a recirculation zone formed under the vehicle body immediately downstream of the vehicle wheel assembly. The fairing body has a tapered aerodynamic surface that extends from a front end to a rear end of the fairing body with a substantially U-shaped cross-section that tapers in both height and width. Fasteners or other mounting devices secure the fairing body to an underside surface of the vehicle body, so that the front end is immediately downstream of the vehicle wheel assembly and a bottom section of the tapered aerodynamic surface rises towards the underside surface as it extends in a downstream direction.

Decoupling control of steering and driving system for in-wheel-motor-drive electric vehicle

NASA Astrophysics Data System (ADS)

Zhang, Han; Zhao, Wanzhong

2018-02-01

To improve the maneuverability and stability of in-wheel-motor-drive electric vehicle, a control strategy based on nonlinear decoupling control method is proposed in this paper, realizing the coordinated control of the steering and driving system. At first, the nonlinear models of the in-wheel-motor-drive electric vehicle and its sub-system are constructed. Then the inverse system decoupling theory is applied to decompose the nonlinear system into several independent subsystems, which makes it possible to realize the coordinated control of each subsystem. Next, the μ-Synthesis theory is applied to eliminate the influence of model uncertainty, improving the stability, robustness and tracking performance of in-wheel-motor-drive electric vehicle. Simulation and experiment results and numerical analyses, based on the electric vehicle actuated by in-wheel-motors, prove that the proposed control method is effective to accomplish the decoupling control of the steering and driving system in both simulation and real practice.

Wheel slip dump valve for railway braking system

NASA Astrophysics Data System (ADS)

Zhang, Xuan; Zhang, LiHao; Li, QingXuan; Shi, YanTao

2017-09-01

As we all know, pneumatic braking system plays an important role in the safety of the whole vehicle. In the anti slip braking system, the pressure of braking cylinder can be adjusted by the quick power response of wheel slip dump valve, so that the lock situation won’t occur during vehicle service. During the braking of railway vehicles, the braking force provided by braking disc reduces vehicle’s speed. But the locking slip will happen due to the oversize of braking force or the reduction of sticking coefficient between wheel and rail. It will cause not only the decline of braking performance but also the increase of braking distance. In the meanwhile, it will scratch the wheel and influence the stable running of vehicles. Now, the speed of passenger vehicle has been increased. In order to shorten the braking distance as far as possible, sticking stickiness must be fully applied. So the occurrence probability of wheel slip is increased.

Articulated Suspension Without Springs

NASA Technical Reports Server (NTRS)

Bickler, Donald B.

1990-01-01

Wheels negotiate bumps and holes with minimal tilting of vehicle body. In new suspension, wheel climbs obstacle as high as 1 1/2 times its diameter without excessive tilting of chassis. Provides highly stable ride over rough ground for such vehicles as wheelchairs, military scout cars, and police and fire robots. System of levers distributes weight to wheels. Sized to distribute equal or other desired portions of load among wheels.

Robotic Two-Wheeled Vehicle

NASA Technical Reports Server (NTRS)

Edlund, Jeffrey E. (Inventor); Burdick, Joel (Inventor); Abad-Manterola, Pablo (Inventor); Matthews, Jaret B. (Inventor); Nesnas, Issa A. D. (Inventor)

2014-01-01

A robotic two-wheeled vehicle comprising a connection body interposed between the two wheels are described. A drum can be coaxially located in a central region of the connection body and can support a hollow arm projecting radially from the drum. A tether can be inserted in the arm and connected to a second drum. Instruments and sensors can be accommodated in a case housed inside each wheel.

Robotic Two-Wheeled Vehicle

NASA Technical Reports Server (NTRS)

Nesnas, Issa A. D. (Inventor); Matthews, Jaret B. (Inventor); Edlund, Jeffrey E. (Inventor); Burdick, Joel (Inventor); Abad-Manterola, Pablo (Inventor)

2013-01-01

A robotic two-wheeled vehicle comprising a connection body interposed between the two wheels are described. A drum can be coaxially located in a central region of the connection body and can support a hollow arm projecting radially from the drum. A tether can be inserted in the arm and connected to a second drum. Instruments and sensors can be accommodated in a case housed inside each wheel.

36 CFR 7.65 - Assateague Island National Seashore.

Code of Federal Regulations, 2013 CFR

2013-07-01

... yards of any waterfowl hunting blind during waterfowl season. (12) Hunting on seashore lands and waters...-the-road vehicles such as beachbuggies, four-wheel-drive vehicles, pickup trucks, and standard... not meet the following standards: On four-wheel-drive vehicles and trailers towed by any vehicle: Per...

36 CFR 7.65 - Assateague Island National Seashore.

Code of Federal Regulations, 2014 CFR

2014-07-01

... yards of any waterfowl hunting blind during waterfowl season. (12) Hunting on seashore lands and waters...-the-road vehicles such as beachbuggies, four-wheel-drive vehicles, pickup trucks, and standard... not meet the following standards: On four-wheel-drive vehicles and trailers towed by any vehicle: Per...

36 CFR 7.65 - Assateague Island National Seashore.

Code of Federal Regulations, 2012 CFR

2012-07-01

... yards of any waterfowl hunting blind during waterfowl season. (12) Hunting on seashore lands and waters...-the-road vehicles such as beachbuggies, four-wheel-drive vehicles, pickup trucks, and standard... not meet the following standards: On four-wheel-drive vehicles and trailers towed by any vehicle: Per...

Fault-tolerant control of electric vehicles with in-wheel motors using actuator-grouping sliding mode controllers

NASA Astrophysics Data System (ADS)

Li, Boyuan; Du, Haiping; Li, Weihua

2016-05-01

Although electric vehicles with in-wheel motors have been regarded as one of the promising vehicle architectures in recent years, the probability of in-wheel motor fault is still a crucial issue due to the system complexity and large number of control actuators. In this study, a modified sliding mode control (SMC) is applied to achieve fault-tolerant control of electric vehicles with four-wheel-independent-steering (4WIS) and four-wheel-independent-driving (4WID). Unlike in traditional SMC, in this approach the steering geometry is re-arranged according to the location of faulty wheels in the modified SMC. Three SMC control laws for longitudinal velocity control, lateral velocity control and yaw rate control are designed based on specific vehicle motion scenarios. In addition the actuator-grouping SMC method is proposed so that driving actuators are grouped and each group of actuators can be used to achieve the specific control target, which avoids the strong coupling effect between each control target. Simulation results prove that the proposed modified SMC can achieve good vehicle dynamics control performance in normal driving and large steering angle turning scenarios. In addition, the proposed actuator-grouping SMC can solve the coupling effect of different control targets and the control performance is improved.

Estimation of actual residual stresses due to braking and contact loading of rail vehicle wheels

DOT National Transportation Integrated Search

1996-03-01

A finite element formulation for shakedown stress analysis of rail vehicle wheels is presented, based on a hypothesis that the shakedown state is axisymmetric. The method can be used to estimate shakedown stresses in wheels subjected to combined mech...

Distributed tactical reasoning framework for intelligent vehicles

NASA Astrophysics Data System (ADS)

Sukthankar, Rahul; Pomerleau, Dean A.; Thorpe, Chuck E.

1998-01-01

In independent vehicle concepts for the Automated Highway System (AHS), the ability to make competent tactical-level decisions in real-time is crucial. Traditional approaches to tactical reasoning typically involve the implementation of large monolithic systems, such as decision trees or finite state machines. However, as the complexity of the environment grows, the unforeseen interactions between components can make modifications to such systems very challenging. For example, changing an overtaking behavior may require several, non-local changes to car-following, lane changing and gap acceptance rules. This paper presents a distributed solution to the problem. PolySAPIENT consists of a collection of autonomous modules, each specializing in a particular aspect of the driving task - classified by traffic entities rather than tactical behavior. Thus, the influence of the vehicle ahead on the available actions is managed by one reasoning object, while the implications of an approaching exit are managed by another. The independent recommendations form these reasoning objects are expressed in the form of votes and vetos over a 'tactical action space', and are resolved by a voting arbiter. This local independence enables PolySAPIENT reasoning objects to be developed independently, using a heterogenous implementation. PolySAPIENT vehicles are implemented in the SHIVA tactical highway simulator, whose vehicles are based on the Carnegie Mellon Navlab robots.

Final Rule for Control of Air Pollution From Motor Vehicles and New Motor Vehicle Engines; Increase of the Vehicle Mass for 3-Wheeled Motorcycles

EPA Pesticide Factsheets

This action changes the regulatory definition of a motorcycle to include 3-wheeled vehicles weighing up to 1749 pounds effective for 1998 and later model year motorcycles for which emission standards are in place.

Dynamics of omnidirectional unmanned rescue vehicle with mecanum wheels

NASA Astrophysics Data System (ADS)

Typiak, Andrzej; Łopatka, Marian Janusz; Rykała, Łukasz; Kijek, Magdalena

2018-01-01

The work presents the dynamic equations of motion of a unmanned six-wheeled vehicle with mecanum wheels for rescue applications derived with the of Lagrange equations of the second kind with multipliers. Analysed vehicle through using mecanum wheels has three degrees of freedom and can move on a flat ground in any direction with any configuration of platform's frame. In order to derive dynamic equations of motion of mentioned object, kinetic potential of the system and generalized forces affecting the system are determined. The results of a solution of inverse dynamics problem are also published.

Wheel slide protection control using a command map and Smith predictor for the pneumatic brake system of a railway vehicle

NASA Astrophysics Data System (ADS)

Lee, Nam-Jin; Kang, Chul-Goo

2016-10-01

In railway vehicles, excessive sliding or wheel locking can occur while braking because of a temporarily degraded adhesion between the wheel and the rail caused by the contaminated or wet surface of the rail. It can damage the wheel tread and affect the performance of the brake system and the safety of the railway vehicle. To safeguard the wheelset from these phenomena, almost all railway vehicles are equipped with wheel slide protection (WSP) systems. In this study, a new WSP algorithm is proposed. The features of the proposed algorithm are the use of the target sliding speed, the determination of a command for WSP valves using command maps, and compensation for the time delay in pneumatic brake systems using the Smith predictor. The proposed WSP algorithm was verified using experiments with a hardware-in-the-loop simulation system including the hardware of the pneumatic brake system.

Analysis of Rail Transit Vehicle Dynamic Curving Performance

DOT National Transportation Integrated Search

1984-06-01

An analytical model is developed for determining the dynamic curving performance of rail transit vehicles. The dynamic wheel/rail interaction forces, vehicle suspension and body motions and track displacement are computed, as well as wheel and rail w...

Experimental studies of breaking of elastic tired wheel under variable normal load

NASA Astrophysics Data System (ADS)

Fedotov, A. I.; Zedgenizov, V. G.; Ovchinnikova, N. I.

2017-10-01

The paper analyzes the braking of a vehicle wheel subjected to disturbances of normal load variations. Experimental tests and methods for developing test modes as sinusoidal force disturbances of the normal wheel load were used. Measuring methods for digital and analogue signals were used as well. Stabilization of vehicle wheel braking subjected to disturbances of normal load variations is a topical issue. The paper suggests a method for analyzing wheel braking processes under disturbances of normal load variations. A method to control wheel baking processes subjected to disturbances of normal load variations was developed.

Overarching Tactical Wheeled Vehicle Study

DTIC Science & Technology

2001-08-31

RECON CO, FMF (RES ONLY) 1 0 0 10 10 0 0 0 0 0 0 N1441 H&SCO, RECONBN, 4TH MARDIV 1 0 0 18 18 0 0 0 0 0 0 H1173 WPNSCO, INFBN, INFREGT/ MPS1 3 0 0 7...4TH MARDIV 6 24 144 0 0 5 30 3 18 2 12 H1121 HQCO, INFREGT/ MPS1 1 12 12 0 0 8 8 4 4 1 1 H1172 H&SCO, INFBN, INFREGT/ MPS1 3 10 30 0 0 5 15 3 9 1 3...1 1 1 0 0 0 0 B3381 DENTALCO, 3D DENTALBN, CSSG-3 (HI) 1 1 1 0 0 0 0 H1023 DET, SERVCO, HQBN/ MPS1 1 23 23 0 0 0 0 H1024 DET, MPCO, HQBN/ MPS1 1 0 0 0

Rear wheel torque vectoring model predictive control with velocity regulation for electric vehicles

NASA Astrophysics Data System (ADS)

Siampis, Efstathios; Velenis, Efstathios; Longo, Stefano

2015-11-01

In this paper we propose a constrained optimal control architecture for combined velocity, yaw and sideslip regulation for stabilisation of the vehicle near the limit of lateral acceleration using the rear axle electric torque vectoring configuration of an electric vehicle. A nonlinear vehicle and tyre model are used to find reference steady-state cornering conditions and design two model predictive control (MPC) strategies of different levels of fidelity: one that uses a linearised version of the full vehicle model with the rear wheels' torques as the input, and another one that neglects the wheel dynamics and uses the rear wheels' slips as the input instead. After analysing the relative trade-offs between performance and computational effort, we compare the two MPC strategies against each other and against an unconstrained optimal control strategy in Simulink and Carsim environment.

Direct yaw moment control and power consumption of in-wheel motor vehicle in steady-state turning

NASA Astrophysics Data System (ADS)

Kobayashi, Takao; Katsuyama, Etsuo; Sugiura, Hideki; Ono, Eiichi; Yamamoto, Masaki

2017-01-01

Driving force distribution control is one of the characteristic performance aspects of in-wheel motor vehicles and various methods have been developed to control direct yaw moment while turning. However, while these controls significantly enhance vehicle dynamic performance, the additional power required to control vehicle motion still remains to be clarified. This paper constructed new formulae of the mechanism by which direct yaw moment alters the cornering resistance and mechanical power of all wheels based on a simple bicycle model, including the electric loss of the motors and the inverters. These formulation results were validated by an actual test vehicle equipped with in-wheel motors in steady-state turning. The validated theory was also applied to a comparison of several different driving force distribution mechanisms from the standpoint of innate mechanical power.

Well-to-Wheels Analysis of Advanced Fuel/Vehicle Systems: A North American Study of Energy Use, Greenhouse Gas Emissions, and Criteria Pollutant Emissions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brinkman, Norman; Wang, Michael; Weber, Trudy

An accurate assessment of future fuel/propulsion system options requires a complete vehicle fuel-cycle analysis, commonly called a well-to-wheels (WTW) analysis. This WTW study analyzes energy use and emissions associated with fuel production (or well-to-tank [WTT]) activities and energy use and emissions associated with vehicle operation (or tank-to-wheels [TTW]) activities.

Stair-climbing capabilities of USU's T3 ODV mobile robot

NASA Astrophysics Data System (ADS)

Robinson, D. Reed; Wood, Carl G.

2001-09-01

A six-wheeled autonomous omni-directional vehicle (ODV) called T3 has been developed at Utah State University's (USU) Center for Self-Organizing and Intelligent Systems (CSOIS). This paper focuses on T3's ability to climb stairs using its unique configuration of 6 independently driven and steered wheels and active suspension height control. The ability of T3, or any similar vehicle, to climb stairs is greatly dependent on the chassis orientation relative to the stairs. Stability criteria is developed for any vehicle dimensions and orientation, on any staircase. All possible yaw and pitch angles on various staircases are evaluated to find vehicle orientations that will allow T3 to climb with the largest margin of stability. Different controller types are investigated for controlling vertical wheel movement with the objective of keeping all wheels in contact with the stairs, providing smooth load transfer between loaded and unloaded wheels, and maintaining optimum chassis pitch and roll angles. A controller is presented that uses feedback from wheel loading, vertical wheel position, and chassis orientation sensors. The implementation of the controller is described, and T3's stair climbing performance is presented and evaluated.

Steering system for a train of rail-less vehicles

DOEpatents

Voight, Edward T.

1983-01-01

A steering system for use with a multiple vehicle train permits tracking without rails of one vehicle after another. This system is particularly useful for moving conveyor systems into and out of curved paths of room and pillar underground mine installations. The steering system features an elongated steering bar pivotally connected to each of adjacent vehicles at end portions of the bar permitting angular orientation of each vehicle in respect to the steering bar and other vehicles. Each end portion of the steering bar is linked to the near pair of vehicle wheels through wheel yoke pivot arms about king pin type pivots. Movement of the steering bar about its pivotal connection provides proportional turning of the wheels to effect steering and tracking of one vehicle following another in both forward and reverse directions.

Steering redundancy for self-driving vehicles using differential braking

NASA Astrophysics Data System (ADS)

Jonasson, M.; Thor, M.

2018-05-01

This paper describes how differential braking can be used to turn a vehicle in the context of providing fail-operational control for self-driving vehicles. Two vehicle models are developed with differential input. The models are used to explain the bounds of curvature that differential braking provides and they are then validated with measurements in a test vehicle. Particular focus is paid on wheel suspension effects that significantly influence the obtained curvature. The vehicle behaviour and its limitations due to wheel suspension effects are, owing to the vehicle models, defined and explained. Finally, a model-based controller is developed to control the vehicle curvature during a fault by differential braking. The controller is designed to compensate for wheel angle disturbance that is likely to occur during the control event.

High-fidelity simulation capability for virtual testing of seismic and acoustic sensors

NASA Astrophysics Data System (ADS)

Wilson, D. Keith; Moran, Mark L.; Ketcham, Stephen A.; Lacombe, James; Anderson, Thomas S.; Symons, Neill P.; Aldridge, David F.; Marlin, David H.; Collier, Sandra L.; Ostashev, Vladimir E.

2005-05-01

This paper describes development and application of a high-fidelity, seismic/acoustic simulation capability for battlefield sensors. The purpose is to provide simulated sensor data so realistic that they cannot be distinguished by experts from actual field data. This emerging capability provides rapid, low-cost trade studies of unattended ground sensor network configurations, data processing and fusion strategies, and signatures emitted by prototype vehicles. There are three essential components to the modeling: (1) detailed mechanical signature models for vehicles and walkers, (2) high-resolution characterization of the subsurface and atmospheric environments, and (3) state-of-the-art seismic/acoustic models for propagating moving-vehicle signatures through realistic, complex environments. With regard to the first of these components, dynamic models of wheeled and tracked vehicles have been developed to generate ground force inputs to seismic propagation models. Vehicle models range from simple, 2D representations to highly detailed, 3D representations of entire linked-track suspension systems. Similarly detailed models of acoustic emissions from vehicle engines are under development. The propagation calculations for both the seismics and acoustics are based on finite-difference, time-domain (FDTD) methodologies capable of handling complex environmental features such as heterogeneous geologies, urban structures, surface vegetation, and dynamic atmospheric turbulence. Any number of dynamic sources and virtual sensors may be incorporated into the FDTD model. The computational demands of 3D FDTD simulation over tactical distances require massively parallel computers. Several example calculations of seismic/acoustic wave propagation through complex atmospheric and terrain environments are shown.

Nomonhan: Japanese-Soviet Tactical Combat, 1939 (Leavenworth Papers, Number 2)

DTIC Science & Technology

1981-01-01

describes the evolution of thatiJA tactical doctrine, and then pre- sents a detailed examination of how a partkular Japanese infantry battalion applied...transpmtation, and a field sanitation unit composed the task force. They set out to hack down and destroy an elu- 21 s1ve foe in the barren desert steppes...this sandy covering, the desert surface was genexally firm enough to support wheeled transport. South of the Holsten Rivex eucalyptus trees grew

77 FR 12197 - Standard for All-Terrain Vehicles

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-29

... National Standard for Four-Wheel All-Terrain Vehicles Equipment Configuration, and Performance Requirements... product safety standard the American National Standard for Four Wheel All-Terrain Vehicles Equipment... shall not have a foldable, removable, or retractable structure in the ATV foot environment; (6...

Stocks and flows of lead-based wheel weights in the United States

USGS Publications Warehouse

Bleiwas, Donald I.

2006-01-01

Lead is used in many widely known applications, such as automobile batteries and radiation shielding. Another lesser known, but long-term, use of lead is in automotive vehicle wheel weights. Lead weights have been used to balance wheels since the 1930s because of its high specific gravity, low relative cost, and its malleability. Out-of-balance tires tend to 'cup' and vibrate and as a result cause excessive wear on tires and vehicle suspension components and result in compromised handling, especially at high speeds. The mass, number, and style of weights needed to balance a wheel depend on the tire's size and weight and on the type and condition of the wheels (rims) on the vehicle. This study addresses an accounting of the stocks and flows of lead contained in lead wheel weights from their manufacture, through use, dissipation, and recycling, and environmental issues associated with the use of lead.

Two wheeled lunar dumptruck

NASA Technical Reports Server (NTRS)

Brus, Michael R.; Haleblain, Ray; Hernandez, Tomas L.; Jensen, Paul E.; Kraynick, Ronald L.; Langley, Stan J.; Shuman, Alan G.

1988-01-01

The design of a two wheel bulk material transport vehicle is described in detail. The design consists of a modified cylindrical bowl, two independently controlled direct drive motors, and two deformable wheels. The bowl has a carrying capacity of 2.8 m (100 ft) and is constructed of aluminum. The low speed, high HP motors are directly connected to the wheels, thus yielding only two moving parts. The wheels, specifically designed for lunar applications, utilize the chevron tread pattern for optimum traction. The vehicle is maneuvered by varying the relative angular velocities of the wheels. The bulk material being transported is unloaded by utilizing the motors to oscillate the bowl back and forth to a height at which dumping is achieved. The analytical models were tested using a scaled prototype of the lunar transport vehicle. The experimental data correlated well with theoretical predictions. Thus, the design established provides a feasible alternative for the handling of bulk material on the moon.

Fault detection method for railway wheel flat using an adaptive multiscale morphological filter

NASA Astrophysics Data System (ADS)

Li, Yifan; Zuo, Ming J.; Lin, Jianhui; Liu, Jianxin

2017-02-01

This study explores the capacity of the morphology analysis for railway wheel flat fault detection. A dynamic model of vehicle systems with 56 degrees of freedom was set up along with a wheel flat model to calculate the dynamic responses of axle box. The vehicle axle box vibration signal is complicated because it not only contains the information of wheel defect, but also includes track condition information. Thus, how to extract the influential features of wheels from strong background noise effectively is a typical key issue for railway wheel fault detection. In this paper, an algorithm for adaptive multiscale morphological filtering (AMMF) was proposed, and its effect was evaluated by a simulated signal. And then this algorithm was employed to study the axle box vibration caused by wheel flats, as well as the influence of track irregularity and vehicle running speed on diagnosis results. Finally, the effectiveness of the proposed method was verified by bench testing. Research results demonstrate that the AMMF extracts the influential characteristic of axle box vibration signals effectively and can diagnose wheel flat faults in real time.

Electric propulsion system for wheeled vehicles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ramos, J.A.

1981-11-03

An electric propulsion system for a wheeled vehicle has a generator and motor connected to a drive shaft and an electrical system for charging a battery during all conditions of power transfer from the wheels of the vehicle to the generator to minimize energy required for propulsion. A variable speed power coupling unit connecting the motor to the drive shaft has sprockets revolving about a belt connected sun sprocket with speed control effected by varying the rate of satellite sprocket rotation.

The Development of Wheels for the Lunar Roving Vehicle

NASA Technical Reports Server (NTRS)

Asnani, Vivake; Delap, Damon; Creager, Colin

2009-01-01

The Lunar Roving Vehicle (LRV) was developed for NASA s Apollo program so astronauts could cover a greater range on the lunar surface, carry more science instruments, and return more soil and rock samples than by foot. Because of the unique lunar environment, the creation of flexible wheels was the most challenging and time consuming aspect of the LRV development. Wheels developed for previous lunar systems were not sufficient for use with this manned vehicle; therefore, several new designs were created and tested. Based on criteria set by NASA, the choices were narrowed down to two: the wire mesh wheel developed by General Motors (GM), and the hoop spring wheel developed by the Bendix Corporation. Each of these underwent intensive mechanical, material, and terramechanical analyses, and in the end, the wire mesh wheel was chosen for the LRV. Though the wire mesh wheel was determined to be the best choice for its particular application, it may be insufficient towards achieving the objectives of future lunar missions that could require higher tractive capability, increased weight capacity, or extended life. Therefore lessons learned from the original LRV wheel development and suggestions for future Moon wheel projects are offered.

Comparative efficiency and driving range of light- and heavy-duty vehicles powered with biomass energy stored in liquid fuels or batteries

PubMed Central

Laser, Mark; Lynd, Lee R.

2014-01-01

This study addresses the question, “When using cellulosic biomass for vehicular transportation, which field-to-wheels pathway is more efficient: that using biofuels or that using bioelectricity?” In considering the question, the level of assumed technological maturity significantly affects the comparison, as does the intended transportation application. Results from the analysis indicate that for light-duty vehicles, over ranges typical in the United States today (e.g., 560–820 miles), field-to-wheels performance is similar, with some scenarios showing biofuel to be more efficient, and others indicating the two pathways to be essentially the same. Over the current range of heavy-duty vehicles, the field-to-wheels efficiency is higher for biofuels than for electrically powered vehicles. Accounting for technological advances and range, there is little basis to expect mature bioelectricity-powered vehicles to have greater field-to-wheels efficiency (e.g., kilometers per gigajoule biomass or per hectare) compared with mature biofuel-powered vehicles. PMID:24550477

Design and development of split-parallel through-the road retrofit hybrid electric vehicle with in-wheel motors

NASA Astrophysics Data System (ADS)

Zulkifli, S. A.; Syaifuddin Mohd, M.; Maharun, M.; Bakar, N. S. A.; Idris, S.; Samsudin, S. H.; Firmansyah; Adz, J. J.; Misbahulmunir, M.; Abidin, E. Z. Z.; Syafiq Mohd, M.; Saad, N.; Aziz, A. R. A.

2015-12-01

One configuration of the hybrid electric vehicle (HEV) is the split-axle parallel hybrid, in which an internal combustion engine (ICE) and an electric motor provide propulsion power to different axles. A particular sub-type of the split-parallel hybrid does not have the electric motor installed on board the vehicle; instead, two electric motors are placed in the hubs of the non-driven wheels, called ‘hub motor’ or ‘in-wheel motor’ (IWM). Since propulsion power from the ICE and IWM is coupled through the vehicle itself, its wheels and the road on which it moves, this particular configuration is termed ‘through-the-road’ (TTR) hybrid. TTR configuration enables existing ICE-powered vehicles to be retrofitted into an HEV with minimal physical modification. This work describes design of a retrofit- conversion TTR-IWM hybrid vehicle - its sub-systems and development work. Operating modes and power flow of the TTR hybrid, its torque coupling and resultant traction profiles are initially discussed.

An investigation into the mechanism of the polygonal wear of metro train wheels and its effect on the dynamic behaviour of a wheel/rail system

NASA Astrophysics Data System (ADS)

Jin, Xuesong; Wu, Lei; Fang, Jianying; Zhong, Shuoqiao; Ling, Liang

2012-12-01

This paper presents a detailed investigation conducted into the mechanism of the polygonal wear of metro train wheels through extensive experiments conducted at the sites. The purpose of the experimental investigation is to determine from where the resonant frequency that causes the polygonal wear of the metro train wheels originates. The experiments include the model tests of a vehicle and its parts and the tracks, the dynamic behaviour test of the vehicle in operation and the observation test of the polygonal wear development of the wheels. The tracks tested include the viaducts and the tunnel tracks. The structure model tests show that the average passing frequency of a polygonal wheel is approximately close to the first bending resonant frequency of the wheelset that is found by the wheelset model test and verified by the finite element analysis of the wheelset. Also, the dynamic behaviour test of the vehicle in operation indicates the main frequencies of the vertical acceleration vibration of the axle boxes, which are dominant in the vertical acceleration vibration of the axle boxes and close to the passing frequency of a polygonal wheel, which shows that the first bending resonant frequency of the wheelset is very exciting in the wheelset operation. The observation test of the polygonal wear development of the wheels indicates an increase in the rate of the polygonal wear of the wheels after their re-profiling. This paper also describes the dynamic models used for the metro vehicle coupled with the ballasted track and the slab track to analyse the effect of the polygonal wear of the wheels on the wheel/rail normal forces.

Vehicle for carrying an object of interest

DOEpatents

Zollinger, W.T.; Ferrante, T.A.

1998-10-13

A vehicle for carrying an object of interest across a supporting surface including a frame having opposite first and second ends; a first pair of wheels fixedly mounted on the first end of the frame; a second pair of wheels pivotally mounted on the second end of the frame; and a pair of motors borne by the frame, each motor disposed in driving relation relative to one of the pairs of wheels, the motors propelling the vehicle across the supporting surface. 8 figs.

Vehicle for carrying an object of interest

DOEpatents

Zollinger, W. Thor; Ferrante, Todd A.

1998-01-01

A vehicle for carrying an object of interest across a supporting surface including a frame having opposite first and second ends; a first pair of wheels fixedly mounted on the first end of the frame; a second pair of wheels pivotally mounted on the second end of the frame; and a pair of motors borne by the frame, each motor disposed in driving relation relative to one of the pairs of wheels, the motors propelling the vehicle across the supporting surface.

Evaluating the Effects of Restraint Systems on 4WD Testing Methodologies: A Collaborative Effort between the NVFEL and ANL

EPA Science Inventory

Testing vehicles for emissions and fuel economy has traditionally been conducted with a single-axle chassis dynamometer. The 2006 SAE All Wheel Drive Symposium cited four wheel drive (4WD) and all wheel drive (AWD) sales as climbing from 20% toward 30% of a motor vehicle mar...

23 CFR 658.5 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-04-01

... truck tractors, each connected by a saddle to the frame or fifth wheel of the forward vehicle of the..., deck, or plate mounted behind the cab and forward of the fifth wheel on the frame of the power unit of... saddle to the frame or fifth wheel of the vehicle in front of it. The saddle is a mechanism that connects...

23 CFR 658.5 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-04-01

... truck tractors, each connected by a saddle to the frame or fifth wheel of the forward vehicle of the..., deck, or plate mounted behind the cab and forward of the fifth wheel on the frame of the power unit of... saddle to the frame or fifth wheel of the vehicle in front of it. The saddle is a mechanism that connects...

23 CFR 658.5 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-04-01

... truck tractors, each connected by a saddle to the frame or fifth wheel of the forward vehicle of the..., deck, or plate mounted behind the cab and forward of the fifth wheel on the frame of the power unit of... saddle to the frame or fifth wheel of the vehicle in front of it. The saddle is a mechanism that connects...

23 CFR 658.5 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-04-01

... truck tractors, each connected by a saddle to the frame or fifth wheel of the forward vehicle of the..., deck, or plate mounted behind the cab and forward of the fifth wheel on the frame of the power unit of... saddle to the frame or fifth wheel of the vehicle in front of it. The saddle is a mechanism that connects...

Stability enhancement and fuel economy of the 4-wheel-drive hybrid electric vehicles by optimal tyre force distribution

NASA Astrophysics Data System (ADS)

Goodarzi, Avesta; Mohammadi, Masoud

2014-04-01

In this paper, vehicle stability control and fuel economy for a 4-wheel-drive hybrid vehicle are investigated. The integrated controller is designed within three layers. The first layer determines the total yaw moment and total lateral force made by using an optimal controller method to follow the desired dynamic behaviour of a vehicle. The second layer determines optimum tyre force distribution in order to optimise tyre usage and find out how the tyres should share longitudinal and lateral forces to achieve a target vehicle response under the assumption that all four wheels can be independently steered, driven, and braked. In the third layer, the active steering, wheel slip, and electrical motor torque controllers are designed. In the front axle, internal combustion engine (ICE) is coupled to an electric motor (EM). The control strategy has to determine the power distribution between ICE and EM to minimise fuel consumption and allowing the vehicle to be charge sustaining. Finally, simulations performed in MATLAB/SIMULINK environment show that the proposed structure could enhance the vehicle stability and fuel economy in different manoeuvres.

Propulsion Wheel Motor for an Electric Vehicle

NASA Technical Reports Server (NTRS)

Herrera, Eduardo (Inventor); Farrell, Logan Christopher (Inventor); Guo, Raymond (Inventor); Junkin, Lucien Q. (Inventor); Bluethmann, William J. (Inventor); Vitale, Robert L. (Inventor); Weber, Steven J. (Inventor); Lee, Chunhao J. (Inventor); Eggleston, IV, Raymond Edward (Inventor); Figuered, Joshua M. (Inventor);

Military Energy Alternatives Conference

DTIC Science & Technology

2012-03-08

Power Generation and Alternative Energy Branch US Army RDECOM CERDEC CP&ID Power Division Aberdeen Proving Ground, MD...Co-generation Applications •Tactical Mobile Power •Vehicle-mounted Auxiliary Power and Environmental Control •Energy Security for Base...Mobile Power (PM MEP / PM CP) Vehicle Power (PM Tactical Vehicle / PM HTV) Portable Solar Photovoltaic (PV) Modules and Mobile Hybrid PV Power Sources

A linear complementarity method for the solution of vertical vehicle-track interaction

NASA Astrophysics Data System (ADS)

Zhang, Jian; Gao, Qiang; Wu, Feng; Zhong, Wan-Xie

2018-02-01

A new method is proposed for the solution of the vertical vehicle-track interaction including a separation between wheel and rail. The vehicle is modelled as a multi-body system using rigid bodies, and the track is treated as a three-layer beam model in which the rail is considered as an Euler-Bernoulli beam and both the sleepers and the ballast are represented by lumped masses. A linear complementarity formulation is directly established using a combination of the wheel-rail normal contact condition and the generalised-α method. This linear complementarity problem is solved using the Lemke algorithm, and the wheel-rail contact force can be obtained. Then the dynamic responses of the vehicle and the track are solved without iteration based on the generalised-α method. The same equations of motion for the vehicle and track are adopted at the different wheel-rail contact situations. This method can remove some restrictions, that is, time-dependent mass, damping and stiffness matrices of the coupled system, multiple equations of motion for the different contact situations and the effect of the contact stiffness. Numerical results demonstrate that the proposed method is effective for simulating the vehicle-track interaction including a separation between wheel and rail.

Articulated suspension system

NASA Technical Reports Server (NTRS)

Bickler, Donald B. (Inventor)

1989-01-01

The invention provides a rough terrain vehicle which maintains a substantially constant weight, and therefore traction, on all wheels, despite one wheel moving considerably higher or lower than the others, while avoiding a very soft spring suspension. The vehicle includes a chassis or body to be supported and a pair of side suspensions at either side of the body. In a six wheel vehicle, each side suspension includes a middle wheel, and front and rear linkages respectively coupling the front and rear wheels to the middle wheel. A body link pivotally connects the front and rear linkages together, with the middle of the body link rising or falling by only a fraction of the rise or fall of any of the three wheels. The body link pivotally supports the middle of the length of the body. A transverse suspension for suspending the end of the body on the side suspensions includes a middle part pivotally connected to the body about a longitudinal axis and opposite ends each pivotally connected to one of the side suspensions along at least a longitudinal axis.

Modeling of the motion of automobile elastic wheel in real-time for creation of wheeled vehicles motion control electronic systems

NASA Astrophysics Data System (ADS)

Balakina, E. V.; Zotov, N. M.; Fedin, A. P.

2018-02-01

Modeling of the motion of the elastic wheel of the vehicle in real-time is used in the tasks of constructing different models in the creation of wheeled vehicles motion control electronic systems, in the creation of automobile stand-simulators etc. The accuracy and the reliability of simulation of the parameters of the wheel motion in real-time when rolling with a slip within the given road conditions are determined not only by the choice of the model, but also by the inaccuracy and instability of the numerical calculation. It is established that the inaccuracy and instability of the calculation depend on the size of the step of integration and the numerical method being used. The analysis of these inaccuracy and instability when wheel rolling with a slip was made and recommendations for reducing them were developed. It is established that the total allowable range of steps of integration is 0.001.0.005 s; the strongest instability is manifested in the calculation of the angular and linear accelerations of the wheel; the weakest instability is manifested in the calculation of the translational velocity of the wheel and moving of the center of the wheel; the instability is less at large values of slip angle and on more slippery surfaces. A new method of the average acceleration is suggested, which allows to significantly reduce (up to 100%) the manifesting of instability of the solution in the calculation of all parameters of motion of the elastic wheel for different braking conditions and for the entire range of steps of integration. The results of research can be applied to the selection of control algorithms in vehicles motion control electronic systems and in the testing stand-simulators

Mid-sized omnidirectional robot with hydraulic drive and steering

NASA Astrophysics Data System (ADS)

Wood, Carl G.; Perry, Trent; Cook, Douglas; Maxfield, Russell; Davidson, Morgan E.

2003-09-01

Through funding from the US Army-Tank-Automotive and Armaments Command's (TACOM) Intelligent Mobility Program, Utah State University's (USU) Center for Self-Organizing and Intelligent Systems (CSOIS) has developed the T-series of omni-directional robots based on the USU omni-directional vehicle (ODV) technology. The ODV provides independent computer control of steering and drive in a single wheel assembly. By putting multiple omni-directional (OD) wheels on a chassis, a vehicle is capable of uncoupled translational and rotational motion. Previous robots in the series, the T1, T2, T3, ODIS, ODIS-T, and ODIS-S have all used OD wheels based on electric motors. The T4 weighs approximately 1400 lbs and features a 4-wheel drive wheel configuration. Each wheel assembly consists of a hydraulic drive motor and a hydraulic steering motor. A gasoline engine is used to power both the hydraulic and electrical systems. The paper presents an overview of the mechanical design of the vehicle as well as potential uses of this technology in fielded systems.

ATHLETE: Lunar Cargo Unloading from a High Deck

NASA Technical Reports Server (NTRS)

Wilcox, Brian H.

2010-01-01

As part of the NASA Exploration Technology Development Program, the Jet Propulsion Laboratory is developing a vehicle called ATHLETE: the All-Terrain Hex-Limbed Extra-Terrestrial Explorer. Each vehicle is based on six wheels at the ends of six multi-degree-of freedom limbs. Because each limb has enough degrees of freedom for use as a general-purpose leg, the wheels can be locked and used as feet to walk out of excessively soft or other extreme terrain. Since the vehicle has this alternative mode of traversing through or at least out of extreme terrain, the wheels and wheel actuators can be sized for nominal terrain. There are substantial mass savings in the wheel and wheel actuators associated with designing for nominal instead of extreme terrain. These mass savings are at least comparable-to or larger-than the extra mass associated with the articulated limbs. As a result, the entire mobility system, including wheels and limbs, can be lighter than a conventional all-terrain mobility chassis. A side benefit of this approach is that each limb has sufficient degrees-of freedom to be used as a general-purpose manipulator (hence the name "limb" instead of "leg"). Our prototype ATHLETE vehicles have quick-disconnect tool adapters on the limbs that allow tools to be drawn out of a "tool belt" and maneuvered by the limb. A power-take-off from the wheel actuates the tools, so that they can take advantage of the 1+ horsepower motor in each wheel to enable drilling, gripping or other power-tool functions.

ATHLETE: a Cargo and Habitat Transporter for the Moon

NASA Technical Reports Server (NTRS)

Wilcox, Brian H.

2009-01-01

As part of the NASA Exploration Technology Development Program, the Jet Propulsion Laboratory is developing a vehicle called ATHLETE: the All-Terrain Hex-Limbed Extra-Terrestrial Explorer. The vehicle concept is based on six wheels at the ends of six multi-degree-of-freedom limbs. Because each limb has enough degrees of freedom for use as a general-purpose leg, the wheels can be locked and used as feet to walk out of excessively soft or other extreme terrain. Since the vehicle has this alternative mode of traversing through (or at least out of) extreme terrain, the wheels and wheel actuators can be sized only for nominal terrain. There are substantial mass savings in the wheels and wheel actuators associated with designing for nominal instead of extreme terrain. These mass savings are comparable-to or larger-than the extra mass associated with the articulated limbs. As a result, the entire mobility system, including wheels and limbs, can be about 25 percent lighter than a conventional mobility chassis for planetary exploration. A side benefit of this approach is that each limb has sufficient degrees-of-freedom for use as a general-purpose manipulator (hence the name "limb" instead of "leg"). Our prototype ATHLETE vehicles have quick-disconnect tool adapters on the limbs that allow tools to be drawn out of a "tool belt" and maneuvered by the limb. A rotating power-take-off from the wheel actuates the tools, so that they can take advantage of the 1-plus-horsepower motor in each wheel to enable drilling, gripping or other power-tool functions.

Designing neuro-fuzzy controller for electromagnetic anti-lock braking system (ABS) on electric vehicle

NASA Astrophysics Data System (ADS)

Pramudijanto, Josaphat; Ashfahani, Andri; Lukito, Rian

2018-03-01

Anti-lock braking system (ABS) is used on vehicles to keep the wheels unlocked in sudden break (inside braking) and minimalize the stop distance of the vehicle. The problem of it when sudden break is the wheels locked so the vehicle steering couldn’t be controlled. The designed ABS system will be applied on ABS simulator using the electromagnetic braking. In normal condition or in condition without braking, longitudinal velocity of the vehicle will be equal with the velocity of wheel rotation, so the slip ratio will be 0 (0%) and if the velocity of wheel rotation is 0 (in locked condition) then the wheels will be slip 1 (100%). ABS system will keep the value of slip ratio so it will be 0.2 (20%). In this final assignment, the method that is used is Neuro-Fuzzy method to control the slip value on the wheels. The input is the expectable slip and the output is slip from plant. The learning algorithm which is used is Backpropagation that will work by feedforward to get actual output and work by feedback to get error value with target output. The network that was made based on fuzzy mechanism which are fuzzification, inference and defuzzification, Neuro-fuzzy controller can reduce overshoot plant respond to 43.2% compared to plant respond without controller by open loop.

Carbody elastic vibrations of high-speed vehicles caused by bogie hunting instability

NASA Astrophysics Data System (ADS)

Wei, Lai; Zeng, Jing; Chi, Maoru; Wang, Jianbin

2017-09-01

In particular locations of the high-speed track, the worn wheel profile matched up with the worn rail profile will lead to an extremely high-conicity wheel-rail contact. Consequently, the bogie hunting instability arises, which further results in the so-called carbody shaking phenomenon. In this paper, the carbody elastic vibrations of a high-speed vehicle in service are firstly introduced. Modal tests are conducted to identity the elastic modes of the carbody. The ride comfort and running safety indices for the tested vehicle are evaluated. The rigid-flexible coupling dynamic model for the high-speed passenger car is then developed by using the FE and MBS coupling approach. The rail profiles in those particular locations are measured and further integrated into the simulation model to reproduce the bogie hunting and carbody elastic vibrations. The effects of wheel and rail wear on the vehicle system response, e.g. wheelset bifurcation graph and carbody vibrations, are studied. Two improvement measures, including the wheel profile modification and rail grinding, are proposed to provide possible solutions. It is found that the wheel-rail contact conicity can be lowered by decreasing wheel flange thickness or grinding rail corner, which is expected to improve the bogie hunting stability under worn rail and worn wheel conditions. The carbody elastic vibrations caused by bogie hunting instability can be further restrained.

Conversion and control of an all-terrain vehicle for use as an autonomous mobile robot

NASA Astrophysics Data System (ADS)

Jacob, John S.; Gunderson, Robert W.; Fullmer, R. R.

1998-08-01

A systematic approach to ground vehicle automation is presented, combining low-level controls, trajectory generation and closed-loop path correction in an integrated system. Development of cooperative robotics for precision agriculture at Utah State University required the automation of a full-scale motorized vehicle. The Triton Predator 8- wheeled skid-steering all-terrain vehicle was selected for the project based on its ability to maneuver precisely and the simplicity of controlling the hydrostatic drivetrain. Low-level control was achieved by fitting an actuator on the engine throttle, actuators for the left and right drive controls, encoders on the left and right drive shafts to measure wheel speeds, and a signal pick-off on the alternator for measuring engine speed. Closed loop control maintains a desired engine speed and tracks left and right wheel speeds commands. A trajectory generator produces the wheel speed commands needed to steer the vehicle through a predetermined set of map coordinates. A planar trajectory through the points is computed by fitting a 2D cubic spline over each path segment while enforcing initial and final orientation constraints at segment endpoints. Acceleration and velocity profiles are computed for each trajectory segment, with the velocity over each segment dependent on turning radius. Left and right wheel speed setpoints are obtained by combining velocity and path curvature for each low-level timestep. The path correction algorithm uses GPS position and compass orientation information to adjust the wheel speed setpoints according to the 'crosstrack' and 'downtrack' errors and heading error. Nonlinear models of the engine and the skid-steering vehicle/ground interaction were developed for testing the integrated system in simulation. These test lead to several key design improvements which assisted final implementation on the vehicle.

Evaluation of the statutory classification of three-wheeled, motorized invalid vehicles.

DOT National Transportation Integrated Search

1978-01-01

In response to an objection by interested individuals to the fact that Virginia law classifies three-wheeled, motorized invalid vehicles as motorcycles and subjects them to all registration, safety inspection, and operator requirements applicable to ...

Synthesis of the adaptive continuous system for the multi-axle wheeled vehicle body oscillation damping

NASA Astrophysics Data System (ADS)

Zhileykin, M. M.; Kotiev, G. O.; Nagatsev, M. V.

2018-02-01

In order to meet the growing mobility requirements for the wheeled vehicles on all types of terrain the engineers have to develop a large number of specialized control algorithms for the multi-axle wheeled vehicle (MWV) suspension improving such qualities as ride comfort, handling and stability. The authors have developed an adaptive algorithm of the dynamic damping of the MVW body oscillations. The algorithm provides high ride comfort and high mobility of the vehicle. The article discloses a method for synthesis of an adaptive dynamic continuous algorithm of the MVW body oscillation damping and provides simulation results proving high efficiency of the developed control algorithm.

Personnel emergency carrier vehicle

NASA Technical Reports Server (NTRS)

Owens, Lester J. (Inventor); Fedor, Otto H. (Inventor)

1987-01-01

A personnel emergency carrier vehicle is disclosed which includes a vehicle frame supported on steerable front wheels and driven rear wheels. A supply of breathing air is connected to quick connect face mask coupling and umbilical cord couplings for supplying breathing air to an injured worker or attendant either with or without a self-contained atmospheric protection suit for protection against hazardous gases at an accident site. A non-sparking hydraulic motion is utilized to drive the vehicle and suitable direction and throttling controls are provided for controlling the delivery of a hydraulic driving fluid from a pressurized hydraulic fluid accumulator. A steering axis is steerable through a handle to steer the front wheels through a linkage assembly.

Armored Family of Vehicles (AFV). Phase 1 Report. Book 3. Volumes 5 thru 8

DTIC Science & Technology

1987-08-31

tactical mobility /agility, tactical and strategic deployability, rapid repair/replacement of damaged or destroyed equipment, lethality, reduced...Mover (CEM). (15) Combat Mobility Vehicle (CMV). (16) Combat Gap Crosser (CGC). (17) Combat Excavator (CEX). (18) Mine Dispensing Vehicle (MDV). (19...economic decision analysis (IAW AR 700-XX, AR 700-127 and AR 700-17) and consideration of mobilization requirements. 7. Transportability

Wheeled hopping robot

DOEpatents

Fischer, Gary J [Albuquerque, NM

2010-08-17

The present invention provides robotic vehicles having wheeled and hopping mobilities that are capable of traversing (e.g. by hopping over) obstacles that are large in size relative to the robot and, are capable of operation in unpredictable terrain over long range. The present invention further provides combustion powered linear actuators, which can include latching mechanisms to facilitate pressurized fueling of the actuators, as can be used to provide wheeled vehicles with a hopping mobility.

The Development of Lightweight Commercial Vehicle Wheels Using Microalloying Steel

NASA Astrophysics Data System (ADS)

Lu, Hongzhou; Zhang, Lilong; Wang, Jiegong; Xuan, Zhaozhi; Liu, Xiandong; Guo, Aimin; Wang, Wenjun; Lu, Guimin

Lightweight wheels can reduce weight about 100kg for commercial vehicles, and it can save energy and reduce emission, what's more, it can enhance the profits for logistics companies. The development of lightweight commercial vehicle wheels is achieved by the development of new steel for rim, the process optimization of flash butt welding, and structure optimization by finite element methods. Niobium micro-alloying technology can improve hole expansion rate, weldability and fatigue performance of wheel steel, and based on Niobium micro-alloying technology, a special wheel steel has been studied whose microstructure are Ferrite and Bainite, with high formability and high fatigue performance, and stable mechanical properties. The content of Nb in this new steel is 0.025% and the hole expansion rate is ≥ 100%. At the same time, welding parameters including electric upsetting time, upset allowance, upsetting pressure and flash allowance are optimized, and by CAE analysis, an optimized structure has been attained. As a results, the weight of 22.5in×8.25in wheel is up to 31.5kg, which is most lightweight comparing the same size wheels. And its functions including bending fatigue performance and radial fatigue performance meet the application requirements of truck makers and logistics companies.

Adaptive controller for regenerative and friction braking system

DOEpatents

Davis, R.I.

1990-10-16

A regenerative and friction braking system for a vehicle having one or more road wheels driven by an electric traction motor includes a driver responsive device for producing a brake demand signal having a magnitude corresponding to the level of braking force selected by the driver and friction and regenerative brakes operatively connected with the road wheels of the vehicle. A system according to this invention further includes control means for operating the friction and regenerative braking subsystems so that maximum brake torques sustainable by the road wheels of the vehicle without skidding or slipping will not be exceeded. 8 figs.

Vehicle having hydraulic and power steering systems using a single high pressure pump

DOEpatents

Bartley, Bradley E.; Blass, James R.; Gibson, Dennis H.

2001-06-22

A vehicle comprises a plurality of wheels attached to a vehicle housing. Also attached to the vehicle housing is a power steering system, including a fluid flow circuit, which is operably coupled to a number of the wheels. An internal combustion engine attached to the vehicle housing is connected to a hydraulically actuated system that includes a high pressure pump. An outlet of the high pressure pump is in fluid communication with the fluid flow circuit.

Design and evaluation of a toroidal wheel for planetary rovers

NASA Technical Reports Server (NTRS)

Koskol, J.; Yerazunis, S. W.

1977-01-01

The inverted toroidal wheel concept was perceived, mathematically quantified, and experimentally verified. The wheel design has a number of important characteristics, namely; (1) the low footprint pressures required for Mars exploration (0.5 to 1.0 psi); (2) high vehicle weight to wheel weight ratios capable of exceeding 10:1; (3) extremely long cyclic endurances tending towards infinite life; and (4) simplicity of design. The concept, in combination with appropriate materials such as titanium or composites, provides a planetary roving vehicle with a very high degree of exploratory mobility, a substantial savings in weight and a high assurity of mission success. Design equations and computation procedures necessary to formulate an inverted wheel are described in detail.

Design and manufacture of wheels for a dual-mode (manned - automatic) lunar surface roving vehicle. Volume 1: Detailed technical report

NASA Technical Reports Server (NTRS)

1970-01-01

The concept development, testing, evaluation, and the selection of a final wheel design concept for a dual-mode lunar surface vehicle (DLRV) is detailed. Four wheel configurations were fabricated (one open wheel and three closed wheel) (and subjected to a series of soft soil, mechanical, and endurance tests. Results show that the open wheel has lower draw-bar pull (slope climbing) capability in loose soil due to its higher ground pressure and tendency to dig in at high wheel slip. Endurance tests indicate that a double mesh, fully enclosed wheel can be developed to meet DLRV life requirements. There is, however, a 1.0 to 1.8 lb/wheel weight penalty associated with the wheel enclosure. Also the button cleats used as grousers for the closed-type wheels result in local stress concentration and early fatigue failure of the wire mesh. Load deflection tests indicate that the stiffness of the covered wheel increased by up to 50% after soil bin testing, due to increased friction between the fabric and the wire mesh caused by the sand. No change in stiffness was found for the open wheel. The single woven mesh open wheel design with a chevron tread is recommended for continued development

All-wheel drive and winter-weather safety.

DOT National Transportation Integrated Search

2013-03-01

It is frequently stated that people living in northern states, the so called Snowbelt of the United : States, benefit with respect to safety from driving all-wheel or four-wheel drive vehicles as : opposed to front or rear-wheel drive only. This stud...

A predictive wheel-soil interaction model for planetary rovers validated in testbeds and against MER Mars rover performance data

NASA Astrophysics Data System (ADS)

Richter, L.; Ellery, A.; Gao, Y.; Michaud, S.; Schmitz, N.; Weiss, S.

Successful designs of vehicles intended for operations on planetary objects outside the Earth demand, just as for terrestrial off-the-road vehicles, a careful assessment of the terrain relevant for the vehicle mission and predictions of the mobility performance to allow rational trade-off's to be made for the choice of the locomotion concept and sizing. Principal issues driving the chassis design for rovers are the stress-strain properties of the planetary surface soil, the distribution of rocks in the terrain representing potential obstacles to movement, and the gravity level on the celestial object in question. Thus far, planetary rovers have been successfully designed and operated for missions to the Earth's moon and to the planet Mars, including NASA's Mars Exploration Rovers (MER's) `Spirit' and `Opportunity' being in operation on Mars since their landings in January 2004. Here we report on the development of a wheel-soil interaction model with application to wheel sizes and wheel loads relevant to current and near-term robotic planetary rovers, i.e. wheel diameters being between about 200 and 500 mm and vertical quasistatic wheel loads in operation of roughly 100 to 200 N. Such a model clearly is indispensable for sizings of future rovers to analyse the aspect of rover mobility concerned with motion across soils. This work is presently funded by the European Space Agency (ESA) as part of the `Rover Chassis Evaluation Tools' (RCET) effort which has developed a set of S/W-implemented models for predictive mobility analysis of rovers in terms of movement on soils and across obstacles, coupled with dedicated testbeds to validate the wheel-soil models. In this paper, we outline the details of the wheel-soil modelling performed within the RCET work and present comparisons of predictions of wheel performance (motion resistance, torque vs. slip and drawbar pull vs. slip) for specific test cases with the corresponding measurements performed in the RCET single wheel testbed and in the RCET system-level testbed, the latter permitting drawbar pull vs. slip measurements for complete rover development vehicles under controlled and homogeneous soil conditions. Required modifications of the wheel-soil model, in particular related to modelling the effect of wheel slip, are discussed. To strengthen the model validation base, we have run single wheel measurements using a spare MER Mars rover wheel and have performed comparisons with MER actual mobility performance data, available through one of us (LR) who is a member of the MER Athena science team. Corresponding results will be presented. Keywords: rovers, wheel, soil, mobility, vehicle performance, RCET (Rover Chassis Evaluation Tools), MER (Mars Exploration Rover mission) 2

Dynamic Performance of Subway Vehicle with Linear Induction Motor System

NASA Astrophysics Data System (ADS)

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

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

Extremity fractures associated with ATVs and dirt bikes: a 10-year national epidemiologic study.

PubMed

Lombardo, D J; Jelsema, T; Gambone, A; Weisman, M; Petersen-Fitts, G; Whaley, J D; Sabesan, V J

2017-08-01

Morbidity and mortality of all-terrain vehicles and dirt bikes have been studied, as well as the association of helmet use and head injury. The purpose of this study is to compare and contrast the patterns of extremity fractures associated with ATVs and dirt bikes. We believe there will be unique and potentially preventable injury patterns associated with dirt bikes and three-wheeled ATVs due to the poor stability of these vehicles. Descriptive epidemiology study. The National Electronic Injury Surveillance System (NEISS) was used to acquire data for extremity fractures related to ATV (three wheels, four wheels, and number of wheels undefined) and dirt bike use from 2007 to 2012. Nationwide estimation of injury incidence was determined using NEISS weight calculations. The database yielded an estimate of 229,362 extremity fractures from 2007 to 2012. The incidence rates of extremity fractures associated with ATV and dirt bike use were 3.87 and 6.85 per 1000 participant-years. The largest proportion of all fractures occurred in the shoulder (27.2%), followed by the wrist and lower leg (13.8 and 12.4%, respectively). There were no differences in the distribution of the location of fractures among four-wheeled or unspecified ATVs. However, three-wheeled ATVs and dirt bikes had much larger proportion of lower leg, foot, and ankle fractures compared to the other vehicle types. While upper extremity fractures were the most commonly observed in this database, three-wheeled ATVs and dirt bikes showed increased proportions of lower extremity fractures. Several organizations have previously advocated for better regulation of the sale and use of these specific vehicles due to increased risks. These findings help illustrate some of the specific risks associated with these commonly used vehicles.

Vehicle dynamics control of four in-wheel motor drive electric vehicle using gain scheduling based on tyre cornering stiffness estimation

NASA Astrophysics Data System (ADS)

Xiong, Lu; Yu, Zhuoping; Wang, Yang; Yang, Chen; Meng, Yufeng

2012-06-01

This paper focuses on the vehicle dynamic control system for a four in-wheel motor drive electric vehicle, aiming at improving vehicle stability under critical driving conditions. The vehicle dynamics controller is composed of three modules, i.e. motion following control, control allocation and vehicle state estimation. Considering the strong nonlinearity of the tyres under critical driving conditions, the yaw motion of the vehicle is regulated by gain scheduling control based on the linear quadratic regulator theory. The feed-forward and feedback gains of the controller are updated in real-time by online estimation of the tyre cornering stiffness, so as to ensure the control robustness against environmental disturbances as well as parameter uncertainty. The control allocation module allocates the calculated generalised force requirements to each in-wheel motor based on quadratic programming theory while taking the tyre longitudinal/lateral force coupling characteristic into consideration. Simulations under a variety of driving conditions are carried out to verify the control algorithm. Simulation results indicate that the proposed vehicle stability controller can effectively stabilise the vehicle motion under critical driving conditions.

Advocates and critics for tactical behaviors in UGV navigation

NASA Astrophysics Data System (ADS)

Hussain, Talib S.; Vidaver, Gordon; Berliner, Jeffrey

2005-05-01

Critical to the development of unmanned ground vehicle platforms is the incorporation of adaptive tactical behaviors for the planning of high-level navigation and tactical actions. BBN Technologies recently completed a simulation-based project for the Army Research Lab (ARL) in which we applied an evolutionary computation approach to navigating through a terrain to capture flag objectives while faced with one or more mobile enemies. Our Advocates and Critics for Tactical Behaviors (ACTB) system evolves plans for the vehicle that control its movement goals (in the form of waypoints), and its future actions (e.g., pointing cameras). We apply domain-specific, state-dependent genetic operators called advocates that promote specific tactical behaviors (e.g., adapt a plan to stay closer to walls). We define the fitness function as a weighted sum of a number of independent, domain-specific, state-dependent evaluation components called critics. Critics reward plans based upon specific tactical criteria, such as minimizing risk of exposure or time to the flags. Additionally, the ACTB system provides the capability for a human commander to specify the "rules of engagement" under which the vehicle will operate. The rules of engagement determine the planning emphasis required under different tactical situations (e.g., discovery of an enemy), and provide a mechanism for automatically adapting the relative selection probabilities of the advocates, the weights of the critics, and the depth of planning in response to tactical events. The ACTB system demonstrated highly effective performance in a head-to-head testing event, held by ARL, against two competing tactical behavior systems.

Motion of an Articulated Vehicle with Two-Dimensional Sections Subject to Lateral Obstacles

NASA Astrophysics Data System (ADS)

Antonyuk, E. Ya.; Zabuga, A. T.

2016-07-01

Some aspects of the geometry, kinematics, and dynamics of a three-section robotic vehicle with a front steerable wheel are studied. The constraints between the wheels and the flat ground are assumed nonholonomic. The vehicle moves in a narrow L-shaped corridor. A path for the characteristic points of the sections of the robot is designed. A dynamic model of the system is developed. The maximum possible dimensions of the robot that allow its unimpeded and non-stop motion are determined. The kinetostatic analysis of the load on a three-section vehicle moving along a planned path is modeled. The holonomic and nonholonomic constraint reactions between the wheels and the ground and in the joints between the sections are determined

Method for controlling a vehicle with two or more independently steered wheels

DOEpatents

Reister, D.B.; Unseren, M.A.

1995-03-28

A method is described for independently controlling each steerable drive wheel of a vehicle with two or more such wheels. An instantaneous center of rotation target and a tangential velocity target are inputs to a wheel target system which sends the velocity target and a steering angle target for each drive wheel to a pseudo-velocity target system. The pseudo-velocity target system determines a pseudo-velocity target which is compared to a current pseudo-velocity to determine a pseudo-velocity error. The steering angle targets and the steering angles are inputs to a steering angle control system which outputs to the steering angle encoders, which measure the steering angles. The pseudo-velocity error, the rate of change of the pseudo-velocity error, and the wheel slip between each pair of drive wheels are used to calculate intermediate control variables which, along with the steering angle targets are used to calculate the torque to be applied at each wheel. The current distance traveled for each wheel is then calculated. The current wheel velocities and steering angle targets are used to calculate the cumulative and instantaneous wheel slip and the current pseudo-velocity. 6 figures.

Evaluation of four steering wheels to determine driver hand placement in a static environment.

PubMed

Mossey, Mary E; Xi, Yubin; McConomy, Shayne K; Brooks, Johnell O; Rosopa, Patrick J; Venhovens, Paul J

2014-07-01

While much research exists on occupant packaging both proprietary and in the literature, more detailed research regarding user preferences for subjective ratings of steering wheel designs is sparse in published literature. This study aimed to explore the driver interactions with production steering wheels in four vehicles by using anthropometric data, driver hand placement, and driver grip design preferences for Generation-Y and Baby Boomers. In this study, participants selected their preferred grip diameter, responded to a series of questions about the steering wheel grip as they sat in four vehicles, and rank ordered their preferred grip design. Thirty-two male participants (16 Baby Boomers between ages 47 and 65 and 16 Generation-Y between ages 18 and 29) participated in the study. Drivers demonstrated different gripping behavior between vehicles and between groups. Recommendations for future work in steering wheel grip design and naturalistic driver hand positioning are discussed. Copyright © 2014. Published by Elsevier Ltd.

A novel dual motor drive system for three wheel electric vehicles

NASA Astrophysics Data System (ADS)

Panmuang, Piyapat; Thongsan, Taweesak; Suwapaet, Nuchida; Laohavanich, Juckamass; Photong, Chonlatee

2018-03-01

This paper presents a novel dual motor drive system used for three wheel electric vehicles that have one free wheel at the front and two wheels with a drive system at the end of the vehicles. A novel dual motor drive system consists of two identical DC motors that are independently controlled by its speed-torque controller. Under light load conditions, only one of the DC motors will operate around it rated whilst under hard load conditions both of the DC motors will operate. With this drive system, the motors will operate only at its high performance at rated or else no operate to retain longer lifetime. The simulated results for the Skylab three wheel electric vehicle prototype with 8kW at full load (high torque, low speed) and around 4kW at light/normal operating loads (regular speed-torque) showed that the proposed system provides better dynamic responses with faster overshoot current/voltage recovery time, has lower investment costs, has longer lifetime of the motors and allows the motors to always operate at their high performance and thus achieve more cost effective system compared to a single motor drive system with 8kW DC motors.

Vehicle load-equalization system

NASA Technical Reports Server (NTRS)

Creasy, W. K.

1976-01-01

System uses cables and associated pulleys to form closed-loop suspension system for terrain compensation. Loop causes reactions at each of three wheels in response to loading at remaining wheel. Simplicity of design should be of interest to designers and manufacturers of construction equipment and off-road vehicles.

Wheelset curving guidance using H∞ control

NASA Astrophysics Data System (ADS)

Qazizadeh, Alireza; Stichel, Sebastian; Feyzmahdavian, Hamid Reza

2018-03-01

This study shows how to design an active suspension system for guidance of a rail vehicle wheelset in curve. The main focus of the study is on designing the controller and afterwards studying its effect on the wheel wear behaviour. The controller is designed based on the closed-loop transfer function shaping method and ? control strategy. The study discusses designing of the controller for both nominal and uncertain plants and considers both stability and performance. The designed controllers in Simulink are then applied to the vehicle model in Simpack to study the wheel wear behaviour in curve. The vehicle type selected for this study is a two-axle rail vehicle. This is because this type of vehicle is known to have very poor curving performance and high wheel wear. On the other hand, the relative simpler structure of this type of vehicle compared to bogie vehicles make it a more economic choice. Hence, equipping this type of vehicle with the active wheelset steering is believed to show high enough benefit to cost ratio to remain attractive to rail vehicle manufacturers and operators.

Traction Aid for Wheeled Vehicles

DTIC Science & Technology

1975-07-01

driver’s position in the load vehicle to assist him in applying constant braking loads, 4) a drum and line fifth wheel sys- tem attached to the load...in Alaskan snow, and the results were so encouraging that further testing of the device was requested. In comparison to tire chains, the Tyr-Trac...vehicle with the end of the line anchored and the speed of the line played off the drum measuring the actual vehicle speed. An eight channel

Low-Cost MEMS Sensors and Vision System for Motion and Position Estimation of a Scooter

PubMed Central

Guarnieri, Alberto; Pirotti, Francesco; Vettore, Antonio

2013-01-01

The possibility to identify with significant accuracy the position of a vehicle in a mapping reference frame for driving directions and best-route analysis is a topic which is attracting a lot of interest from the research and development sector. To reach the objective of accurate vehicle positioning and integrate response events, it is necessary to estimate position, orientation and velocity of the system with high measurement rates. In this work we test a system which uses low-cost sensors, based on Micro Electro-Mechanical Systems (MEMS) technology, coupled with information derived from a video camera placed on a two-wheel motor vehicle (scooter). In comparison to a four-wheel vehicle; the dynamics of a two-wheel vehicle feature a higher level of complexity given that more degrees of freedom must be taken into account. For example a motorcycle can twist sideways; thus generating a roll angle. A slight pitch angle has to be considered as well; since wheel suspensions have a higher degree of motion compared to four-wheel motor vehicles. In this paper we present a method for the accurate reconstruction of the trajectory of a “Vespa” scooter; which can be used as alternative to the “classical” approach based on GPS/INS sensor integration. Position and orientation of the scooter are obtained by integrating MEMS-based orientation sensor data with digital images through a cascade of a Kalman filter and a Bayesian particle filter. PMID:23348036

Low-Cost MEMS sensors and vision system for motion and position estimation of a scooter.

PubMed

Guarnieri, Alberto; Pirotti, Francesco; Vettore, Antonio

2013-01-24

The possibility to identify with significant accuracy the position of a vehicle in a mapping reference frame for driving directions and best-route analysis is a topic which is attracting a lot of interest from the research and development sector. To reach the objective of accurate vehicle positioning and integrate response events, it is necessary to estimate position, orientation and velocity of the system with high measurement rates. In this work we test a system which uses low-cost sensors, based on Micro Electro-Mechanical Systems (MEMS) technology, coupled with information derived from a video camera placed on a two-wheel motor vehicle (scooter). In comparison to a four-wheel vehicle; the dynamics of a two-wheel vehicle feature a higher level of complexity given that more degrees of freedom must be taken into account. For example a motorcycle can twist sideways; thus generating a roll angle. A slight pitch angle has to be considered as well; since wheel suspensions have a higher degree of motion compared to four-wheel motor vehicles. In this paper we present a method for the accurate reconstruction of the trajectory of a "Vespa" scooter; which can be used as alternative to the "classical" approach based on GPS/INS sensor integration. Position and orientation of the scooter are obtained by integrating MEMS-based orientation sensor data with digital images through a cascade of a Kalman filter and a Bayesian particle filter.

Development of a vehicle-track model assembly and numerical method for simulation of wheel-rail dynamic interaction due to unsupported sleepers

NASA Astrophysics Data System (ADS)

Zhu, Jian Jun; Ahmed, A. K. W.; Rakheja, Subhash; Khajepour, Amir

2010-12-01

In practice, it is not very uncommon to find railway track systems with unsupported sleepers due to the uneven settlement of a ballasted track system. These unsupported sleepers are among the major vibration excitations for a train and track system when a train moves forwards on a track. The vibration induced by unsupported sleepers can cause a large dynamic contact force between wheels and rails. For heavily loaded high-speed trains, the deteriorated sleeper support may lead to accelerated degradation of the railway track and vehicle components, and may thus impose safety risk to the operation. This paper presents analyses of a coupled vehicle-track assembly consisting of a roll plane vehicle model, a continuous track system model and an adaptive wheel-rail contact model. In order to improve the simulation efficiency, a numerical approach based on the central finite difference method is proposed in this investigation. The developed model assembly and proposed simulation method are utilised to simulate the vehicle-track dynamic interaction in the presence of unsupported sleepers. The dynamic response in terms of the dynamic wheel-rail interaction force due to one or multiple unsupported sleepers is studied. Important factors influencing the dynamic wheel-rail interaction force in the presence of sleeper voids are also investigated. The results show that the vehicle speed, the gap size and the number of unsupported sleepers primarily dictate the magnitude of impact load which can be significant.

Single wheel hub motor failures and their impact on vehicle and driver behaviour

NASA Astrophysics Data System (ADS)

Wanner, Daniel; Kreußlein, Maria; Augusto, Bruno; Drugge, Lars; Stensson Trigell, Annika

2016-10-01

This research work studies the impact of single wheel hub motor failures on the dynamic behaviour of electric vehicles and the corresponding driver reactions. An experimental study in a moving-base driving simulator is conducted to analyse the influence of single wheel hub motor failures for motorway speeds. Driver reaction times are derived from the measured data and discussed in their experimental context. The failure is rated objectively on the dynamic behaviour of the vehicle and compared to the subjective evaluation. Findings indicate that critical traffic situations impairing traffic safety can occur for motorway speeds. Clear counteractions by the drivers had to be taken.

Railway bogie vibration analysis by mathematical simulation model and a scaled four-wheel railway bogie set

NASA Astrophysics Data System (ADS)

Visayataksin, Noppharat; Sooklamai, Manon

2018-01-01

The bogie is the part that connects and transfers all the load from the vehicle body onto the railway track; interestingly the interaction between wheels and rails is the critical point for derailment of the rail vehicles. However, observing or experimenting with real bogies on rail vehicles is impossible due to the operational rules and safety concerns. Therefore, this research aimed to develop a vibration analysis set for a four-wheel railway bogie by constructing a four-wheel bogie with scale of 1:4.5. The bogie structures, including wheels and axles, were made from an aluminium alloy, equipped with springs and dampers. The bogie was driven by an electric motor using 4 round wheels instead of 2 straight rails, with linear velocity between 0 to 11.22 m/s. The data collected from the vibration analysis set was compared to the mathematical simulation model to investigate the vibration behavior of the bogie, especially the hunting motion. The results showed that vibration behavior from a scaled four-wheel railway bogie set significantly agreed with the mathematical simulation model in terms of displacement and hunting frequency. The critical speed of the wheelset was found by executing the mathematical simulation model at 13 m/s.

21 CFR 890.3800 - Motorized three-wheeled vehicle.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Motorized three-wheeled vehicle. 890.3800 Section 890.3800 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3800...

21 CFR 890.3800 - Motorized three-wheeled vehicle.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Motorized three-wheeled vehicle. 890.3800 Section 890.3800 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3800...

21 CFR 890.3800 - Motorized three-wheeled vehicle.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Motorized three-wheeled vehicle. 890.3800 Section 890.3800 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3800...

21 CFR 890.3800 - Motorized three-wheeled vehicle.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Motorized three-wheeled vehicle. 890.3800 Section 890.3800 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3800...

21 CFR 890.3800 - Motorized three-wheeled vehicle.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Motorized three-wheeled vehicle. 890.3800 Section 890.3800 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3800...

Mobility-Dependent Motion Planning for High Speed Robotic Vehicles

DTIC Science & Technology

2008-07-25

of the vehicle’s mobility in such type of terrain. Moreover, autonomous driv- ing of wheeled vehicles at high speeds adds a new level of complexity due...dynamic effects such as wheel slip, skidding, ballistic behavior, rollover, and vehicle-terrain interaction phenomena. Navigation algorithms must also...description of mobility was defined as the probability that for a given 6 ini ial v 10 ity at an initial po ition h robo will hav a non-n gative ve- loci y

Optimisation of active suspension control inputs for improved vehicle ride performance

NASA Astrophysics Data System (ADS)

Čorić, Mirko; Deur, Joško; Xu, Li; Tseng, H. Eric; Hrovat, Davor

2016-07-01

A collocation-type control variable optimisation method is used in the paper to analyse to which extent the fully active suspension (FAS) can improve the vehicle ride comfort while preserving the wheel holding ability. The method is first applied for a cosine-shaped bump road disturbance of different heights, and for both quarter-car and full 10 degree-of-freedom vehicle models. A nonlinear anti-wheel hop constraint is considered, and the influence of bump preview time period is analysed. The analysis is then extended to the case of square- or cosine-shaped pothole with different lengths, and the quarter-car model. In this case, the cost function is extended with FAS energy consumption and wheel damage resilience costs. The FAS action is found to be such to provide a wheel hop over the pothole, in order to avoid or minimise the damage at the pothole trailing edge. In the case of long pothole, when the FAS cannot provide the wheel hop, the wheel is travelling over the pothole bottom and then hops over the pothole trailing edge. The numerical optimisation results are accompanied by a simplified algebraic analysis.

Tire-road friction estimation and traction control strategy for motorized electric vehicle.

PubMed

Jin, Li-Qiang; Ling, Mingze; Yue, Weiqiang

2017-01-01

In this paper, an optimal longitudinal slip ratio system for real-time identification of electric vehicle (EV) with motored wheels is proposed based on the adhesion between tire and road surface. First and foremost, the optimal longitudinal slip rate torque control can be identified in real time by calculating the derivative and slip rate of the adhesion coefficient. Secondly, the vehicle speed estimation method is also brought. Thirdly, an ideal vehicle simulation model is proposed to verify the algorithm with simulation, and we find that the slip ratio corresponds to the detection of the adhesion limit in real time. Finally, the proposed strategy is applied to traction control system (TCS). The results showed that the method can effectively identify the state of wheel and calculate the optimal slip ratio without wheel speed sensor; in the meantime, it can improve the accelerated stability of electric vehicle with traction control system (TCS).

A numerical investigation on the efficiency of range extending systems using Advanced Vehicle Simulator

NASA Astrophysics Data System (ADS)

Varnhagen, Scott; Same, Adam; Remillard, Jesse; Park, Jae Wan

2011-03-01

Series plug-in hybrid electric vehicles of varying engine configuration and battery capacity are modeled using Advanced Vehicle Simulator (ADVISOR). The performance of these vehicles is analyzed on the bases of energy consumption and greenhouse gas emissions on the tank-to-wheel and well-to-wheel paths. Both city and highway driving conditions are considered during the simulation. When simulated on the well-to-wheel path, it is shown that the range extender with a Wankel rotary engine consumes less energy and emits fewer greenhouse gases compared to the other systems with reciprocating engines during many driving cycles. The rotary engine has a higher power-to-weight ratio and lower noise, vibration and harshness compared to conventional reciprocating engines, although performs less efficiently. The benefits of a Wankel engine make it an attractive option for use as a range extender in a plug-in hybrid electric vehicle.

Automatic guidance control of an articulated all-wheel-steered vehicle

NASA Astrophysics Data System (ADS)

Kim, Young Chol; Yun, Kyong-Han; Min, Kyung-Deuk

2014-04-01

This paper presents automatic guidance control of a single-articulated all-wheel-steered vehicle being developed by the Korea Railroad Research Institute. The vehicle has an independent drive motor on each wheel except for the front axle. The guidance controller is designed so that the vehicle follows the given reference path within permissible lateral deviations. We use a three-input/three-output linearised model derived from the nonlinear dynamic model of the vehicle. For the purpose of simplifying the controller and making it tunable, we consider a decentralised control configuration. We first design a second-order decoupling compensator for the two-input/two-output system that is strongly coupled and then design a first-order controller for each decoupled feedback loop by using the characteristic ratio assignment method. The simulation results for the nonlinear dynamic model indicate that the proposed control configuration successfully achieves the design objectives.

Tire-road friction estimation and traction control strategy for motorized electric vehicle

PubMed Central

Jin, Li-Qiang; Yue, Weiqiang

2017-01-01

In this paper, an optimal longitudinal slip ratio system for real-time identification of electric vehicle (EV) with motored wheels is proposed based on the adhesion between tire and road surface. First and foremost, the optimal longitudinal slip rate torque control can be identified in real time by calculating the derivative and slip rate of the adhesion coefficient. Secondly, the vehicle speed estimation method is also brought. Thirdly, an ideal vehicle simulation model is proposed to verify the algorithm with simulation, and we find that the slip ratio corresponds to the detection of the adhesion limit in real time. Finally, the proposed strategy is applied to traction control system (TCS). The results showed that the method can effectively identify the state of wheel and calculate the optimal slip ratio without wheel speed sensor; in the meantime, it can improve the accelerated stability of electric vehicle with traction control system (TCS). PMID:28662053

49 CFR 213.345 - Vehicle/track system qualification.

Code of Federal Regulations, 2013 CFR

2013-10-01

... in accordance with the requirements of this paragraph (c). (1) Simulations or measurement of wheel/rail forces. For vehicle types intended to operate at track Class 6 speeds, simulations or measurement... exceed the wheel/rail force safety limits specified in § 213.333. Simulations, if conducted, shall be in...

49 CFR 213.345 - Vehicle/track system qualification.

Code of Federal Regulations, 2014 CFR

2014-10-01

... in accordance with the requirements of this paragraph (c). (1) Simulations or measurement of wheel/rail forces. For vehicle types intended to operate at track Class 6 speeds, simulations or measurement... exceed the wheel/rail force safety limits specified in § 213.333. Simulations, if conducted, shall be in...

Rail corrugation growth accounting for the flexibility and rotation of the wheel set and the non-Hertzian and non-steady-state effects at contact patch

NASA Astrophysics Data System (ADS)

Vila, Paloma; Baeza, Luis; Martínez-Casas, José; Carballeira, Javier

2014-05-01

In this work, a simulation tool is developed to analyse the growth of rail corrugation consisting of several models connected in a feedback loop in order to account for both the short-term dynamic vehicle-track interaction and the long-term damage. The time-domain vehicle-track interaction model comprises a flexible rotating wheel set model, a cyclic track model based on a substructuring technique and a non-Hertzian and non-steady-state three-dimensional wheel-rail contact model, based on the variational theory by Kalker. Wear calculation is performed with Archard's wear model by using the contact parameters obtained with the non-Hertzian and non-steady-state three-dimensional contact model. The aim of this paper is to analyse the influence of the excitation of two coinciding resonances of the flexible rotating wheel set on the rail corrugation growth in the frequency range from 20 to 1500 Hz, when contact conditions similar to those that can arise while a wheel set is negotiating a gentle curve are simulated. Numerical results show that rail corrugation grows only on the low rail for two cases in which two different modes of the rotating wheel set coincide in frequency. In the first case, identified by using the Campbell diagram, the excitation of both the backward wheel mode and the forward third bending mode of the wheel set model (B-F modes) promotes the growth of rail corrugation with a wavelength of 110 mm for a vehicle velocity of 142 km/h. In the second case, the excitation of both the backward wheel mode and the backward third bending mode (B-B modes) gives rise to rail corrugation growth at a wavelength of 156 mm when the vehicle velocity is 198 km/h.

Air actuated clutch for four wheel drive vehicles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Clohessy, K.E.

1986-12-09

A control system is described for selectively engaging and disengaging a vehicle wheel and a vehicle drive mechanism comprising; a spindle having inside and outside rotative support surfaces, the spindle adapted to be mounted to a vehicle frame, an axle portion rotatably supported on the inside support surface, and drive means for selectively and rotatively driving the axle portion relative to the spindle; a wheel hub assembly adapted to carry a vehicle wheel, the hub assembly rotatively supported on the outside support surface of the spindle; a sealed expansion chamber defined in part by the spindle, the axle portion, themore » hub assembly and a movable wall carried by the hub assembly, venting means venting the outer side of the movable wall to atmospheric pressure, the clutch ring engaged by the movable wall for movement of the clutch ring with movement of the movable wall as induced by a pressure difference generated within the chamber, and pressurizing means for selectively pressurizing and depressurizing the expansion chamber to thereby selectively shift the clutch ring between the positions of interlocking the axle portion and hub assembly and unlocking the axle portion and hub assembly.« less

Estimation of longitudinal force, lateral vehicle speed and yaw rate for four-wheel independent driven electric vehicles

NASA Astrophysics Data System (ADS)

Chen, Te; Xu, Xing; Chen, Long; Jiang, Haobing; Cai, Yingfeng; Li, Yong

2018-02-01

Accurate estimation of longitudinal force, lateral vehicle speed and yaw rate is of great significance to torque allocation and stability control for four-wheel independent driven electric vehicle (4WID-EVs). A fusion method is proposed to estimate the longitudinal force, lateral vehicle speed and yaw rate for 4WID-EVs. The electric driving wheel model (EDWM) is introduced into the longitudinal force estimation, the longitudinal force observer (LFO) is designed firstly based on the adaptive high-order sliding mode observer (HSMO), and the convergence of LFO is analyzed and proved. Based on the estimated longitudinal force, an estimation strategy is then presented in which the strong tracking filter (STF) is used to estimate lateral vehicle speed and yaw rate simultaneously. Finally, co-simulation via Carsim and Matlab/Simulink is carried out to demonstrate the effectiveness of the proposed method. The performance of LFO in practice is verified by the experiment on chassis dynamometer bench.

Multiple-degree-of-freedom vehicle

DOEpatents

Borenstein, Johann

1995-01-01

A multi-degree-of-freedom vehicle employs a compliant linkage to accommodate the need for a variation in the distance between drive wheels or drive systems which are independently steerable and drivable. The subject vehicle is provided with rotary encodes to provide signals representative of the orientation of the steering pivot associated with each such drive wheel or system, and a linear encoder which issues a signal representative of the fluctuations in the distance between the drive elements. The wheels of the vehicle are steered and driven in response to the linear encoder signal, there being provided a controller system for minimizing the fluctuations in the distance. The controller system is a software implementation of a plurality of controllers, operating at the chassis level and at the vehicle level. A trajectory interpolator receives x-displacement, y-displacement, and .theta.-displacement signals and produces to the vehicle level controller trajectory signals corresponding to interpolated control signals. The x-displacement, y-displacement, and .theta.-displacement signals are received from a human operator, via a manipulable joy stick.

Zero-moment point determination of worst-case manoeuvres leading to vehicle wheel lift

NASA Astrophysics Data System (ADS)

Lapapong, S.; Brown, A. A.; Swanson, K. S.; Brennan, S. N.

2012-01-01

This paper proposes a method to evaluate vehicle rollover propensity based on a frequency-domain representation of the zero-moment point (ZMP). Unlike other rollover metrics such as the static stability factor, which is based on the steady-state behaviour, and the load transfer ratio, which requires the calculation of tyre forces, the ZMP is based on a simplified kinematic model of the vehicle and the analysis of the contact point of the vehicle relative to the edge of the support polygon. Previous work has validated the use of the ZMP experimentally in its ability to predict wheel lift in the time domain. This work explores the use of the ZMP in the frequency domain to allow a chassis designer to understand how operating conditions and vehicle parameters affect rollover propensity. The ZMP analysis is then extended to calculate worst-case sinusoidal manoeuvres that lead to untripped wheel lift, and the analysis is tested across several vehicle configurations and compared with that of the standard Toyota J manoeuvre.

77 FR 75697 - Petition for Waiver of Compliance

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-21

... wheel loads when a rail vehicle traverses a curve. With the right combination of speed, curvature, and... wheels will be equal, i.e., balanced. The curving speed corresponding to this balanced state is referred... the outer wheel load to increase and the inner wheel load to decrease. The manifestation of this load...

16 CFR 1420.3 - Requirements for four-wheel ATVs.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Requirements for four-wheel ATVs. 1420.3... REGULATIONS REQUIREMENTS FOR ALL TERRAIN VEHICLES § 1420.3 Requirements for four-wheel ATVs. (a) Each ATV shall comply with all applicable provisions of the American National Standard for Four Wheel All-Terrain...

29 CFR 1917.44 - General rules applicable to vehicles. 4

Code of Federal Regulations, 2012 CFR

2012-07-01

... shall first be deflated by valve core removal; and (ix) Before assembly, wheel components shall be... outside the frame of the device for any wheel position within the device. When the wheel assembly is... trailer road wheels prior to disconnection of the trailer and until braking is again provided. Section 49...

49 CFR 570.59 - Service brake system.

Code of Federal Regulations, 2014 CFR

2014-10-01

... the following tests. (1) Roller-type or drive-on platform tests. The force applied by the brake on a front wheel or a rear wheel shall not differ by more than 25 percent from the force applied by the brake on the other front wheel or the other rear wheel respectively. (i) Inspection procedure. The vehicle...

29 CFR 1917.44 - General rules applicable to vehicles. 4

Code of Federal Regulations, 2013 CFR

2013-07-01

... shall first be deflated by valve core removal; and (ix) Before assembly, wheel components shall be... outside the frame of the device for any wheel position within the device. When the wheel assembly is... trailer road wheels prior to disconnection of the trailer and until braking is again provided. Section 49...

29 CFR 1917.44 - General rules applicable to vehicles. 4

Code of Federal Regulations, 2014 CFR

2014-07-01

... shall first be deflated by valve core removal; and (ix) Before assembly, wheel components shall be... outside the frame of the device for any wheel position within the device. When the wheel assembly is... trailer road wheels prior to disconnection of the trailer and until braking is again provided. Section 49...

49 CFR 570.59 - Service brake system.

Code of Federal Regulations, 2010 CFR

2010-10-01

... the following tests. (1) Roller-type or drive-on platform tests. The force applied by the brake on a front wheel or a rear wheel shall not differ by more than 25 percent from the force applied by the brake on the other front wheel or the other rear wheel respectively. (i) Inspection procedure. The vehicle...

49 CFR 570.59 - Service brake system.

Code of Federal Regulations, 2011 CFR

2011-10-01

... the following tests. (1) Roller-type or drive-on platform tests. The force applied by the brake on a front wheel or a rear wheel shall not differ by more than 25 percent from the force applied by the brake on the other front wheel or the other rear wheel respectively. (i) Inspection procedure. The vehicle...

49 CFR 570.59 - Service brake system.

Code of Federal Regulations, 2013 CFR

2013-10-01

... the following tests. (1) Roller-type or drive-on platform tests. The force applied by the brake on a front wheel or a rear wheel shall not differ by more than 25 percent from the force applied by the brake on the other front wheel or the other rear wheel respectively. (i) Inspection procedure. The vehicle...

49 CFR 570.59 - Service brake system.

Code of Federal Regulations, 2012 CFR

2012-10-01

... the following tests. (1) Roller-type or drive-on platform tests. The force applied by the brake on a front wheel or a rear wheel shall not differ by more than 25 percent from the force applied by the brake on the other front wheel or the other rear wheel respectively. (i) Inspection procedure. The vehicle...

Influence of the track quality and of the properties of the wheel-rail rolling contact on vehicle dynamics

NASA Astrophysics Data System (ADS)

Suarez, Berta; Felez, Jesus; Lozano, José Antonio; Rodriguez, Pablo

2013-02-01

This work describes an analytical approach to determine what degree of accuracy is required in the definition of the rail vehicle models used for dynamic simulations. This way it would be possible to know in advance how the results of simulations may be altered due to the existence of errors in the creation of rolling stock models, whilst also identifying their critical parameters. This would make it possible to maximise the time available to enhance dynamic analysis and focus efforts on factors that are strictly necessary. In particular, the parameters related both to the track quality and to the rolling contact were considered in this study. With this aim, a sensitivity analysis was performed to assess their influence on the vehicle dynamic behaviour. To do this, 72 dynamic simulations were performed modifying, one at a time, the track quality, the wheel-rail friction coefficient and the equivalent conicity of both new and worn wheels. Three values were assigned to each parameter, and two wear states were considered for each type of wheel, one for new wheels and another one for reprofiled wheels. After processing the results of these simulations, it was concluded that all the parameters considered show very high influence, though the friction coefficient shows the highest influence. Therefore, it is recommended to undertake any future simulation job with measured track geometry and track irregularities, measured wheel profiles and normative values of the wheel-rail friction coefficient.

Wheel liner design for improved sound and structural performances

NASA Astrophysics Data System (ADS)

Oltean, Alexandru; Diaconescu, Claudiu; Tabacu, Ştefan

2017-10-01

Vehicle noise is composed mainly of wheel-road noise and noise from the power unit. At low speeds power unit noise dominates while at high speeds wheel-road noise dominates as wheel-road noise level increases approximately logarithmically with speed. The wheel liner is designed as a component of the vehicle that has a multiple role. It has to prevent the dirt or water from the road surface that are engaged by the wheel to access the engine/front bay. Same time it has the important role to reduce perceived noised in the passenger’s compartment that comes from the wheel-road interaction. Progress in plastic injection moulding technology allowed for new structures to be developed - nonwoven materials in combination with a PP based carrier structure which benefits from a cell structure caused by MuCell injection moulding. The results are light parts with increased sound absorption performances. An adapted combination of materials and production processes can provide the solution for stiff yet soundproofing structures valued for modern vehicles. Sound absorption characteristics of materials used for wheel liners applications were reported in this study. Different polypropylene and polyester fibre-based thermally bonded nonwovens varying in weight and thickness were investigated. Having as a background the performances of the nonwoven material the microcellular structure was part of the analysis. Acoustical absorptive behaviour was explained by analysing the results obtained using the impedance tube and correlating with the knowledge of materials structure.

Influence of switches and crossings on wheel profile evolution in freight vehicles

NASA Astrophysics Data System (ADS)

Casanueva, Carlos; Doulgerakis, Emmanouil; Jönsson, Per-Anders; Stichel, Sebastian

2014-05-01

Wheel reprofiling costs for freight vehicles are a major issue in Sweden, reducing the profitability of freight traffic operations and therefore hindering the modal shift needed for achieving reduced emissions. In order to understand the damage modes in freight vehicles, uniform wear prediction with Archard's wear law has been studied in a two-axle timber transport wagon, and simulation results have been compared to measurements. Challenges of wheel wear prediction in freight wagons are discussed, including the influence of block brakes and switches and crossings. The latter have a major influence on the profile evolution of this case study, so specific simulations are performed and a thorough discussion is carried out.

AGATE: Adversarial Game Analysis for Tactical Evaluation

NASA Technical Reports Server (NTRS)

Huntsberger, Terrance L.

2013-01-01

AGATE generates a set of ranked strategies that enables an autonomous vehicle to track/trail another vehicle that is trying to break the contact using evasive tactics. The software is efficient (can be run on a laptop), scales well with environmental complexity, and is suitable for use onboard an autonomous vehicle. The software will run in near-real-time (2 Hz) on most commercial laptops. Existing software is usually run offline in a planning mode, and is not used to control an unmanned vehicle actively. JPL has developed a system for AGATE that uses adversarial game theory (AGT) methods (in particular, leader-follower and pursuit-evasion) to enable an autonomous vehicle (AV) to maintain tracking/ trailing operations on a target that is employing evasive tactics. The AV trailing, tracking, and reacquisition operations are characterized by imperfect information, and are an example of a non-zero sum game (a positive payoff for the AV is not necessarily an equal loss for the target being tracked and, potentially, additional adversarial boats). Previously, JPL successfully applied the Nash equilibrium method for onboard control of an autonomous ground vehicle (AGV) travelling over hazardous terrain.

Onboard Hydrogen/Helium Sensors in Support of the Global Technical Regulation: An Assessment of Performance in Fuel Cell Electric Vehicle Crash Tests

DOE Office of Scientific and Technical Information (OSTI.GOV)

Post, M. B.; Burgess, R.; Rivkin, C.

2012-09-01

Automobile manufacturers in North America, Europe, and Asia project a 2015 release of commercial hydrogen fuel cell powered light-duty road vehicles. These vehicles will be for general consumer applications, albeit initially in select markets but with much broader market penetration expected by 2025. To assure international harmony, North American, European, and Asian regulatory representatives are striving to base respective national regulations on an international safety standard, the Global Technical Regulation (GTR), Hydrogen Fueled Vehicle, which is part of an international agreement pertaining to wheeled vehicles and equipment for wheeled vehicles.

Elimination of spades in wheeled military vehicles using MR-fluid dampers

NASA Astrophysics Data System (ADS)

Hosseinloo, Ashkan H.; Vahdati, Nader; Yap, Fook Fah

2011-03-01

Tracked military vehicles were the choice of fighting vehicles due to their heavy fire power, better armor package distribution, better traction, and ability to fire on the move without spades. Many armies are converting to all wheeled vehicles, but one of the drawbacks is the inability to fire on the move without spades. A 2D heave pitch vehicle model for HMMWV has been developed. Simulation results indicate that by the use of MR-fluid dampers with the skyhook controls, it is possible to remove the spades, control chassis vibration, and prevent vehicle lift off during mortar firing, without bursting the tires.

Development and validation of a wear model for the analysis of the wheel profile evolution in railway vehicles

NASA Astrophysics Data System (ADS)

Auciello, J.; Ignesti, M.; Malvezzi, M.; Meli, E.; Rindi, A.

2012-11-01

The numerical wheel wear prediction in railway applications is of great importance for different aspects, such as the safety against vehicle instability and derailment, the planning of wheelset maintenance interventions and the design of an optimal wheel profile from the wear point of view. For these reasons, this paper presents a complete model aimed at the evaluation of the wheel wear and the wheel profile evolution by means of dynamic simulations, organised in two parts which interact with each other mutually: a vehicle's dynamic model and a model for the wear estimation. The first is a 3D multibody model of a railway vehicle implemented in SIMPACK™, a commercial software for the analysis of mechanical systems, where the wheel-rail interaction is entrusted to a C/C++user routine external to SIMPACK, in which the global contact model is implemented. In this regard, the research on the contact points between the wheel and the rail is based on an innovative algorithm developed by the authors in previous works, while normal and tangential forces in the contact patches are calculated according to Hertz's theory and Kalker's global theory, respectively. Due to the numerical efficiency of the global contact model, the multibody vehicle and the contact model interact directly online during the dynamic simulations. The second is the wear model, written in the MATLAB® environment, mainly based on an experimental relationship between the frictional power developed at the wheel-rail interface and the amount of material removed by wear. Starting from a few outputs of the multibody simulations (position of contact points, contact forces and rigid creepages), it evaluates the local variables, such as the contact pressures and local creepages, using a local contact model (Kalker's FASTSIM algorithm). These data are then passed to another subsystem which evaluates, by means of the considered experimental relationship, both the material to be removed and its distribution along the wheel profile, obtaining the correspondent worn wheel geometry. The wheel wear evolution is reproduced by dividing the overall chosen mileage to be simulated in discrete spatial steps: at each step, the dynamic simulations are performed by means of the 3D multibody model keeping the wheel profile constant, while the wheel geometry is updated through the wear model only at the end of the discrete step. Thus, the two parts of the whole model work alternately until the completion of the whole established mileage. Clearly, the choice of an appropriate step length is one of the most important aspects of the procedure and it directly affects the result accuracy and the required computational time to complete the analysis. The whole model has been validated using experimental data relative to tests performed with the ALn 501 'Minuetto' vehicle in service on the Aosta-Pre Saint Didier track; this work has been carried out thanks to a collaboration with Trenitalia S.p.A and Rete Ferroviaria Italiana, which have provided the necessary technical data and experimental results.

Wheel slip control with torque blending using linear and nonlinear model predictive control

NASA Astrophysics Data System (ADS)

Basrah, M. Sofian; Siampis, Efstathios; Velenis, Efstathios; Cao, Dongpu; Longo, Stefano

2017-11-01

Modern hybrid electric vehicles employ electric braking to recuperate energy during deceleration. However, currently anti-lock braking system (ABS) functionality is delivered solely by friction brakes. Hence regenerative braking is typically deactivated at a low deceleration threshold in case high slip develops at the wheels and ABS activation is required. If blending of friction and electric braking can be achieved during ABS events, there would be no need to impose conservative thresholds for deactivation of regenerative braking and the recuperation capacity of the vehicle would increase significantly. In addition, electric actuators are typically significantly faster responding and would deliver better control of wheel slip than friction brakes. In this work we present a control strategy for ABS on a fully electric vehicle with each wheel independently driven by an electric machine and friction brake independently applied at each wheel. In particular we develop linear and nonlinear model predictive control strategies for optimal performance and enforcement of critical control and state constraints. The capability for real-time implementation of these controllers is assessed and their performance is validated in high fidelity simulation.

Dynamic train-track interaction at high vehicle speeds—Modelling of wheelset dynamics and wheel rotation

NASA Astrophysics Data System (ADS)

Torstensson, P. T.; Nielsen, J. C. O.; Baeza, L.

2011-10-01

Vertical dynamic train-track interaction at high vehicle speeds is investigated in a frequency range from about 20 Hz to 2.5 kHz. The inertial effects due to wheel rotation are accounted for in the vehicle model by implementing a structural dynamics model of a rotating wheelset. Calculated wheel-rail contact forces using the flexible, rotating wheelset model are compared with contact forces based on rigid, non-rotating models. For a validation of the train-track interaction model, calculated contact forces are compared with contact forces measured using an instrumented wheelset. When the system is excited at a frequency where two different wheelset mode shapes, due to the wheel rotation, have coinciding resonance frequencies, significant differences are found in the contact forces calculated with the rotating and non-rotating wheelset models. Further, the use of a flexible, rotating wheelset model is recommended for load cases leading to large magnitude contact force components in the high-frequency range (above 1.5 kHz). In particular, the influence of the radial wheel eigenmodes with two or three nodal diameters is significant.

Leg pairs as virtual wheels

NASA Astrophysics Data System (ADS)

Howe, Russel; Duttweiler, Mark; Khanlian, Luke; Setrakian, Mark

2005-05-01

We propose the use of virtual wheels as the starting point of a new vehicle design. Each virtual wheel incorporates a pair of simple legs that, by simulating the rotary motion and ground contact of a traditional wheel, combine many of the benefits of legged and wheeled motion. We describe the use of virtual wheels in the design of a robotic mule, presenting an analysis of the mule's mobility the results of our efforts to model and build such a device.

Cold Regions Test of Tracked and Wheeled Vehicles

DTIC Science & Technology

2015-12-11

with CTIS setting in the Highway setting and Mud, Sand and Snow setting. (7) Conduct the trials a minimum of three times at each speed as stated in...lock brake system. Record the stopping distance data and record any slew from the centerline. Document if the vehicle experiences engine stall ...while operating in snow. The TOP includes guidance for snow as well as mud, sand , swamps, and wet clay. Most conventional wheeled vehicles cannot

Vehicle Performance Recorder (VPR)/ HMMWV (High Mobility Multi-Purpose Wheeled Vehicle) Interface Verification.

DTIC Science & Technology

1984-05-01

hybrid transmission used in the VPR vehicle. From these comparisons made with HMMWV Developmental Test data, confidence can be placed in the validity of...I ............ ........ . ... .... ......... I................ l........ igr 3-2 Drwa pul .1 - hg rne 4004 .. d 3000 \\. PR VEIcLE 2000...Engine: GMC, V-8 diesel, 6.2 L. Transmission: Model THM 475/400 ( hybrid ). Transfer: New process 218, full time 4-wheel drive. Differential: Gleasman

Health Monitoring for Condition-Based Maintenance of a HMMWV using an Instrumented Diagnostic Cleat

DTIC Science & Technology

2008-10-15

identify faults in the bearings, shaft , etc. In wheeled ground vehicles, loading varies significantly as mentioned above. If loads acting on the...vehicle could be fully measured or controlled in terms of the terrain input motions and/or spindle forces/moments, fault identification in wheeled...diagnostic results. - Vehicle speed traversing the cleat can be controlled. - Configuration of cleats can be designed to develop specific tests for

Corrosion Prevention for Wheeled Vehicle Systems

DTIC Science & Technology

1993-08-13

The audit objective was to evaluate the effectiveness and efficiency of the Army’s procedures for acquiring corrosion prevention and chemical agent...resistant coatings for wheeled vehicle systems. To accomplish this objective, we reviewed corrosion controls and painting processes. The audit also...included a review of the adequacy of internal controls related to the audit objective.

Advanced emergency braking under split friction conditions and the influence of a destabilising steering wheel torque

NASA Astrophysics Data System (ADS)

Tagesson, Kristoffer; Cole, David

2017-07-01

The steering system in most heavy trucks is such that it causes a destabilising steering wheel torque when braking on split friction, that is, different friction levels on the two sides of the vehicle. Moreover, advanced emergency braking systems are now mandatory in most heavy trucks, making vehicle-induced split friction braking possible. This imposes higher demands on understanding how the destabilising steering wheel torque affects the driver, which is the focus here. Firstly, an experiment has been carried out involving 24 subjects all driving a truck where automatic split friction braking was emulated. Secondly, an existing driver-vehicle model has been adapted and implemented to improve understanding of the observed outcome. A common conclusion drawn, after analysing results, is that the destabilising steering wheel torque only has a small effect on the motion of the vehicle. The underlying reason is a relatively slow ramp up of the disturbance in comparison to the observed cognitive delay amongst subjects; also the magnitude is low and initially suppressed by passive driver properties.

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

PubMed Central

Jiang, Yanhua; Xiong, Guangming; Chen, Huiyan; Lee, Dah-Jye

2014-01-01

This paper presents a monocular visual odometry algorithm that incorporates a wheeled vehicle model for ground vehicles. The main innovation of this algorithm is to use the single-track bicycle model to interpret the relationship between the yaw rate and side slip angle, which are the two most important parameters that describe the motion of a wheeled vehicle. Additionally, the pitch angle is also considered since the planar-motion hypothesis often fails due to the dynamic characteristics of wheel suspensions and tires in real-world environments. Linearization is used to calculate a closed-form solution of the motion parameters that works as a hypothesis generator in a RAndom SAmple Consensus (RANSAC) scheme to reduce the complexity in solving equations involving trigonometric. All inliers found are used to refine the winner solution through minimizing the reprojection error. Finally, the algorithm is applied to real-time on-board visual localization applications. Its performance is evaluated by comparing against the state-of-the-art monocular visual odometry methods using both synthetic data and publicly available datasets over several kilometers in dynamic outdoor environments. PMID:25256109

The Effects of Tactical Vehicle Training on the Lands of Fort Carson, Colorado. An Ecological Assessment.

DTIC Science & Technology

1984-12-01

Laboratory [USA-CERLI, 1974), p 13. W. D. Severinghaus, R. E. Riggins, and W. D. Coran , Effects of Tracked Vehicle Activity on Terrestrial Mammals, Birds...and Vegetation at Fort S Knox, KY, Special Report N-77/ADA073782 (USA-CERL, 1979), pp 1-64; W. D. Severinghaus and W. D. Coran , Effects of Tactical

Early Synthetic Prototyping: Exploring Designs and Concepts Within Games

DTIC Science & Technology

2014-12-01

UAS unmanned aircraft system UGV unmanned ground vehicle USD(AT&L) Under Secretary of Defense for Acquisition, Technology, and Logistics... unmanned aircraft system (UAS) realm for the wingman concept? The players were familiar with the Marine Corps’ unmanned tactical autonomous control and...UTACCS Unmanned Tactical Autonomous Control and Collaboration System VBIED vehicle borne improvised explosive device VBS2/3 Virtual Battlespace

Multi-point contact of the high-speed vehicle-turnout system dynamics

NASA Astrophysics Data System (ADS)

Ren, Zunsong

2013-05-01

The wheel-rail contact problems, such as the number, location and the track of contact patches, are very important for optimizing the spatial structure of the rails and lowering the vehicle-turnout system dynamics. However, the above problems are not well solved currently because of having the difficulties in how to determine the multi-contact, to preciously present the changeable profiles of the rails and to establish an accurate spatial turnout system dynamics model. Based on a high-speed vehicle-turnout coupled model in which the track is modeled as flexible with rails and sleepers represented by beams, the line tracing extreme point method is introduced to investigate the wheel-rail multiple contact conditions and the key sections of the blade rail, longer nose rail, shorter rail in the switch and nose rail area are discretized to represent the varying profiles of rails in the turnout. The dynamic interaction between the vehicle and turnout is simulated for cases of the vehicle divergently passing the turnout and the multi-point contact is obtained. The tracks of the contact patches on the top of the rails are presented and the wheel-rail impact forces are offered in comparison with the contact patches transference on the rails. The numerical simulation results indicate that the length of two-point contact occurrence of a worn wheel profile and rails is longer than that of the new wheel profile and rails; The two-point contact definitely occurs in the switch and crossing area. Generally, three-point contact doesn't occur for the new rail profile, which is testified by the wheel-rails interpolation distance and the first order derivative function of the tracing line extreme points. The presented research is not only helpful to optimize the structure of the turnout, but also useful to lower the dynamics of the high speed vehicle-turnout system.

Vehicle wheel drag coefficient in relation to travelling velocity - CFD analysis

NASA Astrophysics Data System (ADS)

Leśniewicz, P.; Kulak, M.; Karczewski, M.

2016-10-01

In order to understand the aerodynamic losses associated with a rotating automobile wheel, a detailed characteristics of the drag coefficient in relation to the applied velocity are necessary. Single drag coefficient value is most often reported for the commercially available vehicles, much less is revealed about the influence of particular car components on the energy consumption in various driving cycles. However, detailed flow potential losses determination is desired for performance estimation. To address these needs, the numerical investigation of an isolated wheel is proposed herein.

Benefit of "Push-pull" Locomotion for Planetary Rover Mobility

NASA Technical Reports Server (NTRS)

Creager, Colin M.; Moreland, Scott Jared; Skonieczny, K.; Johnson, K.; Asnani, V.; Gilligan, R.

2011-01-01

As NASAs exploration missions on planetary terrains become more aggressive, a focus on alternative modes of locomotion for rovers is necessary. In addition to climbing steep slopes, the terrain in these extreme environments is often unknown and can be extremely hard to traverse, increasing the likelihood of a vehicle or robot becoming damaged or immobilized. The conventional driving mode in which all wheels are either driven or free-rolling is very efficient on flat hard ground, but does not always provide enough traction to propel the vehicle through soft or steep terrain. This paper presents an alternative mode of travel and investigates the fundamental differences between these locomotion modes. The methods of push-pull locomotion discussed can be used with articulated wheeled vehicles and are identified as walking or inchinginch-worming. In both cases, the braked non-rolling wheels provide increased thrust. An in-depth study of how soil reacts under a rolling wheel vs. a braked wheel was performed by visually observing the motion of particles beneath the surface. This novel technique consists of driving or dragging a wheel in a soil bin against a transparent wall while high resolution, high-rate photographs are taken. Optical flow software was then used to determine shearing patterns in the soil. Different failure modes were observed for the rolling and braked wheel cases. A quantitative comparison of inching vs. conventional driving was also performed on a full-scale vehicle through a series of drawbar pull tests in the Lunar terrain strength simulant, GRC-1. The effect of tire stiffness was also compared; typically compliant tires provide better traction when driving in soft soil, however its been observed that rigid wheels may provide better thrust when non-rolling. Initial tests indicate up to a possible 40 increase in pull force capability at high slip when inching vs. rolling.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schey, Stephen; Francfort, Jim

Task 1includes a survey of the inventory of non-tactical fleet vehicles at Naval Air Station Whidbey Island (NASWI) to characterize the fleet. This information and characterization are used to select vehicles for monitoring that takes place during Task 2. This monitoring involves data logging of vehicle operation in order to identify the vehicle’s mission and travel requirements. Individual observations of these selected vehicles provide the basis for recommendations related to PEV adoption. It also identifies whether a battery electric vehicle or plug-in hybrid electric vehicle (collectively referred to as PEVs) can fulfill the mission requirements and provide observations related tomore » placement of PEV charging infrastructure. This report provides the results of the assessments and observations of the current non-tactical fleet, fulfilling the Task 1 requirements.« less

Wheels and Tracks in Snow. Validation Study of the CRREL Shallow Snow Mobility Model

DTIC Science & Technology

1990-11-01

define g. an insignificant effect on T we plotted all of the for a vehicle by traction data for the wheels/ fracks vehicles, and for the CIV, against...divided by the number of depth, structure, water content, temperature, and contact points and the average contact area of these even type and strength

Tracked Vehicle Road Wheel Puller

DTIC Science & Technology

2009-02-01

employed for removing smaller-size components, such as bolts and the like. U.S. Patent No. 5,410,792, issued to Freeman (3), discloses a caster wheel ...separation of the rubberized annular layer from the outer annular surface of the wheel . Figure 5 further illustrates a modification of the wheel puller...2001. 2. Rubino et al. Pulling Tool. U.S. Patent 5,479,688, 1996. 3. Freeman. Caster Wheel Axle Extraction Apparatus. U.S. Patent 5,410,792

Testing of Lightweight Fuel Cell Vehicles System at Low Speeds with Energy Efficiency Analysis

NASA Astrophysics Data System (ADS)

Mustaffa, Muhammad Rizuwan B.; Mohamed, Wan Ahmad Najmi B. Wan

2013-12-01

A fuel cell vehicle power train mini test bench was developed which consists of a 1 kW open cathode hydrogen fuel cell, electric motor, wheel, gearing system, DC/DC converter and vehicle control system (VCS). Energy efficiency identification and energy flow evaluation is a useful tool in identifying a detail performance of each component and sub-systems in a fuel cell vehicle system configuration. Three artificial traction loads was simulated at 30 kg, 40 kg and 50 kg force on a single wheel drive configuration. The wheel speed range reported here covers from idle to 16 km/h (low speed range) as a preliminary input in the research work frame. The test result shows that the system efficiency is 84.5 percent when the energy flow is considered from the fuel cell to the wheel and 279 watts of electrical power was produced by the fuel cell during that time. Dynamic system responses was also identified as the load increases beyond the motor traction capabilities where the losses at the converter and motor controller increased significantly as it tries to meet the motor traction power demands. This work is currently being further expanded within the work frame of developing a road-worthy fuel cell vehicle.

Aerodynamic analysis of an isolated vehicle wheel

NASA Astrophysics Data System (ADS)

Leśniewicz, P.; Kulak, M.; Karczewski, M.

2014-08-01

Increasing fuel prices force the manufacturers to look into all aspects of car aerodynamics including wheels, tyres and rims in order to minimize their drag. By diminishing the aerodynamic drag of vehicle the fuel consumption will decrease, while driving safety and comfort will improve. In order to properly illustrate the impact of a rotating wheel aerodynamics on the car body, precise analysis of an isolated wheel should be performed beforehand. In order to represent wheel rotation in contact with the ground, presented CFD simulations included Moving Wall boundary as well as Multiple Reference Frame should be performed. Sliding mesh approach is favoured but too costly at the moment. Global and local flow quantities obtained during simulations were compared to an experiment in order to assess the validity of the numerical model. Results of investigation illustrates dependency between type of simulation and coefficients (drag and lift). MRF approach proved to be a better solution giving result closer to experiment. Investigation of the model with contact area between the wheel and the ground helps to illustrate the impact of rotating wheel aerodynamics on the car body.

Wheel Unloading of Rail Vehicles Due to Track Twist

DOT National Transportation Integrated Search

1986-02-01

An analysis is presented describing the effect that track twist has on the loads carried by the wheels of a rail car. Wheel unloading is determined as a function of the difference in crosslevel between the truck centers of the car. The different vehi...

Efficient direct yaw moment control: tyre slip power loss minimisation for four-independent wheel drive vehicle

NASA Astrophysics Data System (ADS)

Kobayashi, Takao; Katsuyama, Etsuo; Sugiura, Hideki; Ono, Eiichi; Yamamoto, Masaki

2018-05-01

This paper proposes an efficient direct yaw moment control (DYC) capable of minimising tyre slip power loss on contact patches for a four-independent wheel drive vehicle. Simulations identified a significant power loss reduction with a direct yaw moment due to a change in steer characteristics during acceleration or deceleration while turning. Simultaneously, the vehicle motion can be stabilised. As a result, the proposed control method can ensure compatibility between vehicle dynamics performance and energy efficiency. This paper also describes the results of a full-vehicle simulation that was conducted to examine the effectiveness of the proposed DYC.

29 CFR 1910.177 - Servicing multi-piece and single piece rim wheels.

Code of Federal Regulations, 2011 CFR

2011-07-01

... rim wheel onto a vehicle axle hub. Removing means the opposite of installing. Mounting a tire means... 29 Labor 5 2011-07-01 2011-07-01 false Servicing multi-piece and single piece rim wheels. 1910.177... § 1910.177 Servicing multi-piece and single piece rim wheels. (a) Scope. (1) This section applies to the...

29 CFR 1910.177 - Servicing multi-piece and single piece rim wheels.

Code of Federal Regulations, 2014 CFR

2014-07-01

... means the transfer and attachment of an assembled rim wheel onto a vehicle axle hub. Removing means the... 29 Labor 5 2014-07-01 2014-07-01 false Servicing multi-piece and single piece rim wheels. 1910.177... § 1910.177 Servicing multi-piece and single piece rim wheels. (a) Scope. (1) This section applies to the...

29 CFR 1910.177 - Servicing multi-piece and single piece rim wheels.

Code of Federal Regulations, 2010 CFR

2010-07-01

... rim wheel onto a vehicle axle hub. Removing means the opposite of installing. Mounting a tire means... 29 Labor 5 2010-07-01 2010-07-01 false Servicing multi-piece and single piece rim wheels. 1910.177... § 1910.177 Servicing multi-piece and single piece rim wheels. (a) Scope. (1) This section applies to the...

29 CFR 1910.177 - Servicing multi-piece and single piece rim wheels.

Code of Federal Regulations, 2013 CFR

2013-07-01

... means the transfer and attachment of an assembled rim wheel onto a vehicle axle hub. Removing means the... 29 Labor 5 2013-07-01 2013-07-01 false Servicing multi-piece and single piece rim wheels. 1910.177... § 1910.177 Servicing multi-piece and single piece rim wheels. (a) Scope. (1) This section applies to the...

29 CFR 1910.177 - Servicing multi-piece and single piece rim wheels.

Code of Federal Regulations, 2012 CFR

2012-07-01

... means the transfer and attachment of an assembled rim wheel onto a vehicle axle hub. Removing means the... 29 Labor 5 2012-07-01 2012-07-01 false Servicing multi-piece and single piece rim wheels. 1910.177... § 1910.177 Servicing multi-piece and single piece rim wheels. (a) Scope. (1) This section applies to the...

On the real-time estimation of the wheel-rail contact force by means of a new nonlinear estimator design model

NASA Astrophysics Data System (ADS)

Strano, Salvatore; Terzo, Mario

2018-05-01

The dynamics of the railway vehicles is strongly influenced by the interaction between the wheel and the rail. This kind of contact is affected by several conditioning factors such as vehicle speed, wear, adhesion level and, moreover, it is nonlinear. As a consequence, the modelling and the observation of this kind of phenomenon are complex tasks but, at the same time, they constitute a fundamental step for the estimation of the adhesion level or for the vehicle condition monitoring. This paper presents a novel technique for the real time estimation of the wheel-rail contact forces based on an estimator design model that takes into account the nonlinearities of the interaction by means of a fitting model functional to reproduce the contact mechanics in a wide range of slip and to be easily integrated in a complete model based estimator for railway vehicle.

Modular Robotic Vehicle

NASA Technical Reports Server (NTRS)

Borroni-Bird, Christopher E. (Inventor); Lapp, Anthony Joseph (Inventor); Vitale, Robert L. (Inventor); Lee, Chunhao J. (Inventor); Bluethmann, William J. (Inventor); Ridley, Justin S. (Inventor); Junkin, Lucien Q. (Inventor); Ambrose, Robert O. (Inventor); Lutz, Jonathan J. (Inventor); Guo, Raymond (Inventor)

2015-01-01

A modular robotic vehicle includes a chassis, driver input devices, an energy storage system (ESS), a power electronics module (PEM), modular electronic assemblies (eModules) connected to the ESS via the PEM, one or more master controllers, and various embedded controllers. Each eModule includes a drive wheel containing a propulsion-braking module, and a housing containing propulsion and braking control assemblies with respective embedded propulsion and brake controllers, and a mounting bracket covering a steering control assembly with embedded steering controllers. The master controller, which is in communication with each eModule and with the driver input devices, communicates with and independently controls each eModule, by-wire, via the embedded controllers to establish a desired operating mode. Modes may include a two-wheel, four-wheel, diamond, and omni-directional steering modes as well as a park mode. A bumper may enable docking with another vehicle, with shared control over the eModules of the vehicles.

Characterization of the powertrain components for a hybrid quadricycle

NASA Astrophysics Data System (ADS)

De Santis, M.; Agnelli, S.; Silvestri, L.; Di Ilio, G.; Giannini, O.

2016-06-01

This paper presents the experimental characterization of a prototyping hybrid electric quadricycle, which is equipped with two independently actuated hub (in-wheel) motors and powered by a 51 V 132 Ah LiFeYPO4 battery pack. Such a vehicle employs two hub motors located in the rear axles in order to independently drive/brake the rear wheels; such architecture allows to implement a torque vectoring system to improve the vehicle dynamics. Due to its actuation flexibility, energy efficiency and performance potentials, this architecture is one of the promising powertrain design for electric quadricycle. Experimental data obtained from measurements on the vehicle powertrain components going from the battery pack to the inverter and to the in-wheel motor were employed to generate the hub motor torque response and power efficiency maps in both driving and regenerative braking modes. Furthermore, the vehicle is equipped with a gasoline internal combustion engine as range extender whose efficiency was also characterized.

Electronic differential for tramcar bogies: system development and performance evaluation by means of numerical simulation

NASA Astrophysics Data System (ADS)

Barbera, Andrea N.; Bucca, Giuseppe; Corradi, Roberto; Facchinetti, Alan; Mapelli, Ferdinando

2014-05-01

The dynamic behaviour of railway vehicles depends on the wheelset configuration, i.e. solid axle wheelset or independently rotating wheels (IRWs). The self-centring behaviour, peculiar of the solid axle wheelset, makes this kind of wheelset very suitable for tangent track running at low speed: the absence of the self-centring mechanism in the IRWs may lead to anomalous wheel/rail wear, reduced vehicle safety and passengers' discomfort. On the contrary, during negotiation of the sharp curves typical of urban tramways, solid axle wheelsets produce lateral contact forces higher than those of IRWs. This paper illustrates an electronic differential system to be applied to tramcar bogies equipped with wheel-hub motors which allows switching from solid axle in tangent track to IRWs in sharp curve (and vice versa). An electro-mechanical vehicle model is adopted for the design of the control system and for the evaluation of the vehicle dynamic performances.

Power transmission device for four wheel drive vehicle

DOE Office of Scientific and Technical Information (OSTI.GOV)

Iwatsuki, T.; Kawamoto, M.; Kano, T.

This patent describes a power transmission device with an improved differential motion limiting mechanism for a four wheel drive vehicle having automatic transmission means, front wheel differential gear means, differential motion limiting means and transfer unit means including center differential gear means, comprising: a first gear mount casing having a gear adapted to mesh with an output of a transmission; a differential motion limiting device arranged together with a front wheel differential gear in the first gear mount casing. The front wheel differential gear having a first diff-carrier and the differential motion limiting device comprising a hydraulic friction clutch formore » engaging and disengaging the first gear mount casing with the first diff-carrier of the front wheel differential gear; a second gear mount casing disposed coaxially with respect to the first gear mount casing; and a transfer unit including a center differential gear arranged in the second gear mount casing, the center differential gear comprising a second diff-carrier coupled with the first gear mount casing, a first side gear coupled with the first diff-carrier of the front wheel differential gear, and a second side gear coupled with the second gear mount casing for transmitting power to the rear wheels.« less

A methodology for analysing lateral coupled behavior of high speed railway vehicles and structures

NASA Astrophysics Data System (ADS)

Antolín, P.; Goicolea, J. M.; Astiz, M. A.; Alonso, A.

2010-06-01

Continuous increment of the speed of high speed trains entails the increment of kinetic energy of the trains. The main goal of this article is to study the coupled lateral behavior of vehicle-structure systems for high speed trains. Non linear finite element methods are used for structures whereas multibody dynamics methods are employed for vehicles. Special attention must be paid when dealing with contact rolling constraints for coupling bridge decks and train wheels. The dynamic models must include mixed variables (displacements and creepages). Additionally special attention must be paid to the contact algorithms adequate to wheel-rail contact. The coupled vehicle-structure system is studied in a implicit dynamic framework. Due to the presence of very different systems (trains and bridges), different frequencies are involved in the problem leading to stiff systems. Regarding to contact methods, a main branch is studied in normal contact between train wheels and bridge decks: penalty method. According to tangential contact FastSim algorithm solves the tangential contact at each time step solving a differential equation involving relative displacements and creepage variables. Integration for computing the total forces in the contact ellipse domain is performed for each train wheel and each solver iteration. Coupling between trains and bridges requires a special treatment according to the kinetic constraints imposed in the wheel-rail pair and the load transmission. A numerical example is performed.

Design and manufacture of wheels for a dual-mode (manned - automatic) lunar surface roving vehicle. Volume 2: Proposed test plan

NASA Technical Reports Server (NTRS)

1970-01-01

A developmental test plan for the wheel and wheel drive assembly of the dual-mode (manned/automated) lunar surface roving vehicle is presented. The tests cover performance, as well as critical environmental characteristics. Insofar as practical, the environmental conditions imposed will be in the sequence expected during the hardware's life from storage through the lunar mission. Test procedures are described for static load deflection and endurance tests. Soft soil tests to determine mobility characteristics including drawbar-pull and thrust vs slip, and motion resistance for various wheel loads are also discussed. Test designs for both ambient and thermal vacuum conditions are described. Facility, transducer, and instrumentation requirements are outlined.

Design of a wheeled articulating land rover

NASA Technical Reports Server (NTRS)

Stauffer, Larry; Dilorenzo, Mathew; Yandle, Barbara

1994-01-01

The WALRUS is a wheeled articulating land rover that will provide Ames Research Center with a reliable, autonomous vehicle for demonstrating and evaluating advanced technologies. The vehicle is one component of the Ames Research Center's on-going Human Exploration Demonstration Project. Ames Research Center requested a system capable of traversing a broad spectrum of surface types and obstacles. In addition, this vehicle must have an autonomous navigation and control system on board and its own source of power. The resulting design is a rover that articulates in two planes of motion to allow for increased mobility and stability. The rover is driven by six conical shaped aluminum wheels, each with an independent, internally coupled motor. Mounted on the rover are two housings and a removable remote control system. In the housings, the motor controller board, tilt sensor, navigation circuitry, and QED board are mounted. Finally, the rover's motors and electronics are powered by thirty C-cell rechargeable batteries, which are located in the rover wheels and recharged by a specially designed battery charger.

Risk assessment of flange climb derailment of a rail vehicle

NASA Astrophysics Data System (ADS)

Vlakhova, A. V.

2015-01-01

We study the wheel flange climb onto the railhead, which is one of the most dangerous regimes of motion and can lead to derailment. The tangential components of the wheel-rail interaction forces are described by the creep model with small slips taken into account. We pass to the limit of infinite rigidity of the interacting bodies (zero slip velocities). It is shown that, in the actual service conditions of rail vehicle motion, neglecting the wheel-rail slip is not justified; namely, the limit model is determined by the primary Dirac constraints, i.e., finite relations between coordinates and momenta arising owing to the system Lagrangian degeneration. The obtained nonclassical model allows one to study the efficiency of some railway motion safety criteria and analytically estimate derailment conditions, which depend on the flange shape, the track curvature radius, the height of the vehicle center of mass, the wheel-rail interaction forces, the coefficients of friction of the interacting surfaces, and the external perturbation forces and moments.

A tank-to-wheel analysis tool for energy and emissions studies in road vehicles.

PubMed

Silva, C M; Gonçalves, G A; Farias, T L; Mendes-Lopes, J M C

2006-08-15

Currently, oil based fuels are the primary energy source of road transport. The growing need for oil independence and CO(2) mitigation has lead to the increasing importance of alternative fuel usage. CO(2) is produced not only as the fuel is used in the vehicle (tank-to-wheel contribution), but also upstream, from the fuel extraction to the refueling station (well-to-tank contribution), and the life cycle of the fuel production (well-to-wheel contribution) must be considered in order to analyse the global impact of the fuel utilization. A road vehicle tank-to-wheel analysis tool that may be integrated with well-to-tank models was developed in the present study. The integration in a demonstration case study allowed to perform a life cycle assessment concerning the utilization of diesel and natural gas fuels in a specific network line of a bus transit company operating in the city of Porto, Portugal.

78 FR 43965 - American Honda Motor Co., Inc., Receipt of Petition for Decision of Inconsequential Noncompliance

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-22

... recall responsibilities of 49 CFR part 573 for the affected vehicles. However, a decision on this... vehicle's tires, up to a total of four tires, is equal to or less than either the pressure 25 percent...; Summary of Honda's Analysis and Arguments A total of approximately 848 wheels, or 212 complete wheel sets...

Wheeled mobility device transportation safety in fixed route and demand-responsive public transit vehicles within the United States.

PubMed

Frost, Karen L; van Roosmalen, Linda; Bertocci, Gina; Cross, Douglas J

2012-01-01

An overview of the current status of wheelchair transportation safety in fixed route and demand-responsive, non-rail, public transportation vehicles within the US is presented. A description of each mode of transportation is provided, followed by a discussion of the primary issues affecting safety, accessibility, and usability. Technologies such as lifts, ramps, securement systems, and occupant restraint systems, along with regulations and voluntary industry standards have been implemented with the intent of improving safety and accessibility for individuals who travel while seated in their wheeled mobility device (e.g., wheelchair or scooter). However, across both fixed route and demand-responsive transit systems a myriad of factors such as nonuse and misuse of safety systems, oversized wheeled mobility devices, vehicle space constraints, and inadequate vehicle operator training may place wheeled mobility device (WhMD) users at risk of injury even under non-impact driving conditions. Since WhMD-related incidents also often occur during the boarding and alighting process, the frequency of these events, along with factors associated with these events are described for each transit mode. Recommendations for improving WhMD transportation are discussed given the current state of

Estimation of Longitudinal Force and Sideslip Angle for Intelligent Four-Wheel Independent Drive Electric Vehicles by Observer Iteration and Information Fusion.

PubMed

Chen, Te; Chen, Long; Xu, Xing; Cai, Yingfeng; Jiang, Haobin; Sun, Xiaoqiang

2018-04-20

Exact estimation of longitudinal force and sideslip angle is important for lateral stability and path-following control of four-wheel independent driven electric vehicle. This paper presents an effective method for longitudinal force and sideslip angle estimation by observer iteration and information fusion for four-wheel independent drive electric vehicles. The electric driving wheel model is introduced into the vehicle modeling process and used for longitudinal force estimation, the longitudinal force reconstruction equation is obtained via model decoupling, the a Luenberger observer and high-order sliding mode observer are united for longitudinal force observer design, and the Kalman filter is applied to restrain the influence of noise. Via the estimated longitudinal force, an estimation strategy is then proposed based on observer iteration and information fusion, in which the Luenberger observer is applied to achieve the transcendental estimation utilizing less sensor measurements, the extended Kalman filter is used for a posteriori estimation with higher accuracy, and a fuzzy weight controller is used to enhance the adaptive ability of observer system. Simulations and experiments are carried out, and the effectiveness of proposed estimation method is verified.

Estimation of Longitudinal Force and Sideslip Angle for Intelligent Four-Wheel Independent Drive Electric Vehicles by Observer Iteration and Information Fusion

PubMed Central

Chen, Long; Xu, Xing; Cai, Yingfeng; Jiang, Haobin; Sun, Xiaoqiang

2018-01-01

Exact estimation of longitudinal force and sideslip angle is important for lateral stability and path-following control of four-wheel independent driven electric vehicle. This paper presents an effective method for longitudinal force and sideslip angle estimation by observer iteration and information fusion for four-wheel independent drive electric vehicles. The electric driving wheel model is introduced into the vehicle modeling process and used for longitudinal force estimation, the longitudinal force reconstruction equation is obtained via model decoupling, the a Luenberger observer and high-order sliding mode observer are united for longitudinal force observer design, and the Kalman filter is applied to restrain the influence of noise. Via the estimated longitudinal force, an estimation strategy is then proposed based on observer iteration and information fusion, in which the Luenberger observer is applied to achieve the transcendental estimation utilizing less sensor measurements, the extended Kalman filter is used for a posteriori estimation with higher accuracy, and a fuzzy weight controller is used to enhance the adaptive ability of observer system. Simulations and experiments are carried out, and the effectiveness of proposed estimation method is verified. PMID:29677124

49 CFR 570.51 - Scope.

Code of Federal Regulations, 2010 CFR

2010-10-01

... suspension systems, and tire and wheel assemblies, of motor vehicles in use with a gross vehicle weight... OF TRANSPORTATION VEHICLE IN USE INSPECTION STANDARDS Vehicles With GVWR of More Than 10,000 Pounds...

UAV Swarm Attack: Protection System Alternatives for Destroyers

DTIC Science & Technology

2012-12-01

Tactical Rocket-Propelled Grenade Airbag Protection System TRL - Technology Readiness Level UAV - Unmanned Aerial Vehicle USN - United States...com- posed of 62 DDGs is $2.014 billion dollars for the 12 year life cycle. J. REACTIVE ARMOR The Tactical Rocket-Propelled Grenade (RPG) Airbag ...Protection System (TRAPS) system involves ‘close-in’ protection using airbags located around a vehicle to minimize the damage from RPGs. This system was

Preliminary analysis of the effects of non-linear creep and flange contact forces on truck performance in curves

DOT National Transportation Integrated Search

1975-05-31

Prediction of wheel displacements and wheel-rail forces is a prerequisite to the evaluation of the curving performance of rail vehicles. This information provides part of the basis for the rational design of wheels and suspension components, for esta...

Stress Reconstruction Analysis of Wheel Saw Cut Tests and Evaluation of Reconstruction Procedure

DOT National Transportation Integrated Search

1993-09-01

The report is the fourth in a series of engineering studies on railroad vehicle wheel performance. The results of saw cut tests performed on one new and one used wheel designed for a fleet of multiple unit (MU) power cars are summarized and analyzed....

Non-Circular Wheels: Reuleaux and Squares

ERIC Educational Resources Information Center

Mills, Allan

2011-01-01

Circular wheels are so familiar on vehicles of all types that it is seldom realized that alternatives do exist. This short non-mathematical article describes Reuleaux and square wheels that, rolling along appropriate tracks, can maintain a moving platform at a constant height. Easily made working models lend themselves to demonstrations at science…

Evaluation of Immediate Actions Taken to Deal with Cracking Problems Observed in Wheels of Rail Commuter Cars

DOT National Transportation Integrated Search

1993-07-01

The report is the first in a series of engineering studies on railroad vehicle wheel performance. Preliminary studies are summarized, involving evaluation of actions taken to respond to high rates of crack occurrence observed in the wheels of certain...

Parameterization of norfolk sandy loam properties for stochastic modeling of light in-wheel motor UGV

USDA-ARS?s Scientific Manuscript database

To accurately develop a mathematical model for an In-Wheel Motor Unmanned Ground Vehicle (IWM UGV) on soft terrain, parameterization of terrain properties is essential to stochastically model tire-terrain interaction for each wheel independently. Operating in off-road conditions requires paying clos...

Advocacy Tactics Found to Differ by Families' Class

ERIC Educational Resources Information Center

Sparks, Sarah D.

2012-01-01

If it's the squeaky wheel that gets the grease, middle-class children are more likely than their lower-income peers to grow up learning how to make the gears of the education system turn smoothly. Working-class parents, meanwhile, tend to raise their children to avoid conflict and be self-sufficient in problem-solving, an Indiana University…

Design and analysis of new fault-tolerant permanent magnet motors for four-wheel-driving electric vehicles

NASA Astrophysics Data System (ADS)

Liu, Guohai; Gong, Wensheng; Chen, Qian; Jian, Linni; Shen, Yue; Zhao, Wenxiang

2012-04-01

In this paper, a novel in-wheel permanent-magnet (PM) motor for four-wheel-driving electrical vehicles is proposed. It adopts an outer-rotor topology, which can help generate a large drive torque, in order to achieve prominent dynamic performance of the vehicle. Moreover, by adopting single-layer concentrated-windings, fault-tolerant teeth, and the optimal combination of slot and pole numbers, the proposed motor inherently offers negligible electromagnetic coupling between different phase windings, hence, it possesses a fault-tolerant characteristic. Meanwhile, the phase back electromotive force waveforms can be designed to be sinusoidal by employing PMs with a trapezoidal shape, eccentric armature teeth, and unequal tooth widths. The electromagnetic performance is comprehensively investigated and the optimal design is conducted by using the finite-element method.

Estimation of Road Friction Coefficient in Different Road Conditions Based on Vehicle Braking Dynamics

NASA Astrophysics Data System (ADS)

Zhao, You-Qun; Li, Hai-Qing; Lin, Fen; Wang, Jian; Ji, Xue-Wu

2017-07-01

The accurate estimation of road friction coefficient in the active safety control system has become increasingly prominent. Most previous studies on road friction estimation have only used vehicle longitudinal or lateral dynamics and often ignored the load transfer, which tends to cause inaccurate of the actual road friction coefficient. A novel method considering load transfer of front and rear axles is proposed to estimate road friction coefficient based on braking dynamic model of two-wheeled vehicle. Sliding mode control technique is used to build the ideal braking torque controller, which control target is to control the actual wheel slip ratio of front and rear wheels tracking the ideal wheel slip ratio. In order to eliminate the chattering problem of the sliding mode controller, integral switching surface is used to design the sliding mode surface. A second order linear extended state observer is designed to observe road friction coefficient based on wheel speed and braking torque of front and rear wheels. The proposed road friction coefficient estimation schemes are evaluated by simulation in ADAMS/Car. The results show that the estimated values can well agree with the actual values in different road conditions. The observer can estimate road friction coefficient exactly in real-time and resist external disturbance. The proposed research provides a novel method to estimate road friction coefficient with strong robustness and more accurate.

Wheel-Sleeper Impact Model in Rail Vehicles Analysis

NASA Astrophysics Data System (ADS)

Brabie, Dan

The current paper establishes the necessary prerequisites for studying post-derailment dynamic behavior of high-speed rail vehicles by means of multi-body system (MBS) software. A finite-element (FE) model of one rail vehicle wheel impacting a limited concrete sleeper volume is built in LS-DYNA. A novel simulation scheme is employed for obtaining the necessary wheel-sleeper impact data, transferred to the MBS code as pre-defined look-up tables of the wheel's impulse variation during impact. The FE model is tentatively validated successfully by comparing the indentation marks with one photograph from an authentic derailment for a continuous impact sequence over three subsequent sleepers. A post-derailment module is developed and implemented in the MBS simulation tool GENSYS, which detects the wheel contact with sleepers and applies valid longitudinal, lateral and vertical force resultants based on the existing impact conditions. The accuracy of the MBS code in terms of the wheels three-dimensional trajectory over 24 consecutive sleepers is successfully compared with its FE counterpart for an arbitrary impact scenario. An axle mounted brake disc is tested as an alternative substitute guidance mechanism after flange climbing derailments at 100 and 200 km/h on the Swedish high-speed tilting train X 2000. Certain combinations of brake disc geometrical parameters manage to stop the lateral deviation of the wheelsets in circular curve sections at high lateral track plane acceleration.

Hybrid-Vehicle Transmission System

NASA Technical Reports Server (NTRS)

Lupo, G.; Dotti, G.

1985-01-01

Continuously-variable transmission system for hybrid vehicles couples internal-combustion engine and electric motor section, either individually or in parallel, to power vehicle wheels during steering and braking.

i3Drive, a 3D interactive driving simulator.

PubMed

Ambroz, Miha; Prebil, Ivan

2010-01-01

i3Drive, a wheeled-vehicle simulator, can accurately simulate vehicles of various configurations with up to eight wheels in real time on a desktop PC. It presents the vehicle dynamics as an interactive animation in a virtual 3D environment. The application is fully GUI-controlled, giving users an easy overview of the simulation parameters and letting them adjust those parameters interactively. It models all relevant vehicle systems, including the mechanical models of the suspension, power train, and braking and steering systems. The simulation results generally correspond well with actual measurements, making the system useful for studying vehicle performance in various driving scenarios. i3Drive is thus a worthy complement to other, more complex tools for vehicle-dynamics simulation and analysis.

Variable Dynamic Testbed Vehicle Dynamics Analysis

DOT National Transportation Integrated Search

1996-03-01

ANTI-ROLL BAR, EMULATION, FOUR-WHEEL-STEERING, LATERAL RESPONSE CHARACTERISTICS, SIMULATION, VARIABLE DYNAMIC TESTBED VEHICLE, INTELLIGENT VEHICLE INITIATIVE OR IVI : THE VARIABLE DYNAMIC TESTBED VEHICLE (VDTV) CONCEPT HAS BEEN PROPOSED AS A TOOL...

Simulation of vertical dynamic vehicle-track interaction in a railway crossing using Green's functions

NASA Astrophysics Data System (ADS)

Li, X.; Torstensson, P. T.; Nielsen, J. C. O.

2017-12-01

Vertical dynamic vehicle-track interaction in the through route of a railway crossing is simulated in the time domain based on a Green's function approach for the track in combination with an implementation of Kalker's variational method to solve the non-Hertzian, and potentially multiple, wheel-rail contact. The track is described by a linear, three-dimensional and non-periodic finite element model of a railway turnout accounting for the variations in rail cross-sections and sleeper lengths, and including baseplates and resilient elements. To reduce calculation time due to the complexity of the track model, involving a large number of elements and degrees-of-freedom, a complex-valued modal superposition with a truncated mode set is applied before the impulse response functions are calculated at various positions along the crossing panel. The variation in three-dimensional contact geometry of the crossing and wheel is described by linear surface elements. In each time step of the contact detection algorithm, the lateral position of the wheelset centre is prescribed but the contact positions on wheel and rail are not, allowing for an accurate prediction of the wheel transition between wing rail and crossing rail. The method is demonstrated by calculating the wheel-rail impact load and contact stress distribution for a nominal S1002 wheel profile passing over a nominal crossing geometry. A parameter study is performed to determine the influence of vehicle speed, rail pad stiffness, lateral wheelset position and wheel profile on the impact load generated at the crossing. It is shown that the magnitude of the impact load is more influenced the wheel-rail contact geometry than by the selection of rail pad stiffness.

Experimental Semiautonomous Vehicle

NASA Technical Reports Server (NTRS)

Wilcox, Brian H.; Mishkin, Andrew H.; Litwin, Todd E.; Matthies, Larry H.; Cooper, Brian K.; Nguyen, Tam T.; Gat, Erann; Gennery, Donald B.; Firby, Robert J.; Miller, David P.;

Torque vectoring for improving stability of small electric vehicles

NASA Astrophysics Data System (ADS)

Grzegożek, W.; Weigel-Milleret, K.

2016-09-01

The electric vehicles solutions based on the individually controlled electric motors propel a single wheel allow to improve the dynamic properties of the vehicle by varying the distribution of the driving torque. Most of the literature refer to the vehicles with a track typical for passenger cars. This paper examines whether the narrow vehicle (with a very small track) torque vectoring bring a noticeable change of the understeer characteristics and whether torque vectoring is possible to use in securing a narrow vehicle from roll over (roll mitigation). The paper contains road tests of the steering characteristics (steady state understeer characteristic quasi-static acceleration with a fixed steering wheel (SH = const) and on the constant radius track (R = const)) of the narrow vehicle. The vehicle understeer characteristic as a function of a power distribution is presented.

Cross-coupled control for all-terrain rovers.

PubMed

Reina, Giulio

2013-01-08

Mobile robots are increasingly being used in challenging outdoor environments for applications that include construction, mining, agriculture, military and planetary exploration. In order to accomplish the planned task, it is critical that the motion control system ensure accuracy and robustness. The achievement of high performance on rough terrain is tightly connected with the minimization of vehicle-terrain dynamics effects such as slipping and skidding. This paper presents a cross-coupled controller for a 4-wheel-drive/4-wheel-steer robot, which optimizes the wheel motors' control algorithm to reduce synchronization errors that would otherwise result in wheel slip with conventional controllers. Experimental results, obtained with an all-terrain rover operating on agricultural terrain, are presented to validate the system. It is shown that the proposed approach is effective in reducing slippage and vehicle posture errors.

Wheel Diameter and Speedometer Reading

NASA Astrophysics Data System (ADS)

Murray, Clifton

2010-09-01

Most introductory physics students have seen vehicles with nonstandard wheel diameters; some may themselves drive "low-rider" cars or "big-wheel" pickup trucks. But how does changing wheel diameter affect speedometer readout for a given speed? Deriving the answer can be followed readily by students who have been introduced to rotation, and it makes a good illustration of how reasoning in physics can lead to a result that is useful outside the classroom.

Influence of Distributed Dead Loads on Vehicle Position for Maximum Moment in Simply Supported Bridges

NASA Astrophysics Data System (ADS)

Gupta, Tanmay; Kumar, Manoj

2017-06-01

Usually, the design moments in the simply supported bridges are obtained as the sum of moments due to dead loads and live load where the live load moments are calculated using the rolling load concept neglecting the effect of dead loads. For the simply supported bridges, uniformly distributed dead load produces maximum moment at mid-span while the absolute maximum bending moment due to multi-axel vehicles occur under a wheel which usually do not lie at mid-span. Since, the location of absolute maximum bending moment due to multi-axel vehicle do not coincide with the location of maximum moment due to dead loads occurring at mid-span, the design moment may not be obtained by simply superimposing the effect of dead load and live load. Moreover, in case of Class-A and Class-70R wheeled vehicular live loads, which consists of several axels, the number of axels to be considered over the bridge of given span and their location is tedious to find out and needs several trials. The aim of the present study is to find the number of wheels for Class-A and Class-70R wheeled vehicles and their precise location to produce absolute maximum moment in the bridge considering the effect of dead loads and impact factor. Finally, in order to enable the designers, the design moments due to Class-70R wheeled and Class-A loading have been presented in tabular form for the spans from 10 to 50 m.

New level of vehicle comfort and vehicle stability via utilisation of the suspensions anti-dive and anti-squat geometry

NASA Astrophysics Data System (ADS)

Lindvai-Soos, Daniel; Horn, Martin

2018-07-01

In this article a novel vehicle dynamics control concept is designed for a vehicle equipped with wheel individual electric traction machines, electronically controlled brakes and semi-active suspensions. The suspension's cross-couplings between traction forces and vertical forces via anti-dive and anti-squat geometry is utilised in the control concept to improve driving comfort and driving stability. The control concept is divided into one main and two cascaded branches. The main controller consists of a multivariable vehicle dynamics controller and a control allocation scheme to improve the vehicle's driving comfort. The cascaded feedback loops maintain the vehicle's stability according to wheel slip and vehicle sideslip. The performance of the combined vehicle dynamics controller is compared to a standard approach in simulation. It can be stated that the controller piloting semi-active suspensions together with brake and traction devices enables a superior performance regarding comfort and stability.

Alternative Fuels Data Center

Science.gov Websites

(DOD) must exhibit a preference for the lease or procurement of motor vehicles with electric or hybrid at a cost reasonably comparable to motor vehicles with internal combustion engines. Tactical vehicles

Joint Light Tactical Vehicle (JLTV): Background and Issues for Congress

DTIC Science & Technology

2017-01-10

Development (TD) Phase to three industry teams: (1) BAE Systems, (2) the team of Lockheed Martin and General Tactical Vehicle, and (3) AM General and...Lockheed Martin Corporation (Grand Prairie, TX); and Oshkosh Corporation (Oshkosh, WI). On September 3, 2013, the Army began JLTV testing at Aberdeen...who were picked in 2012 to build prototypes—Oshkosh, Lockheed Martin , and AM General—submitted their bids for the LRIP contract by the February 10

Full Hybrid: Braking

Science.gov Websites

wasted energy from braking into electricity and stores it in the battery. In regenerative braking, the electric motor is reversed so that, instead of using electricity to turn the wheels, the rotating wheels turn the motor and create electricity. Using energy from the wheels to turn the motor slows the vehicle

Dynamics of a Two-Link Vehicle in an L-Shaped Corridor Revisited

NASA Astrophysics Data System (ADS)

Antonyuk, E. Ya.; Zabuga, A. T.

2014-03-01

The kinematics of a two-link mobile robot with three steerable wheels moving in an L-shaped corridor is analyzed. A smooth (with continuous first derivative) path is designed maintaining the optimal maneuverability of the vehicle. The motion of the vehicle along this path is planned. Analytical expressions for the reactions at the contact of the wheels with the ground are given in the general case of motion. The radius of curvature of the programmed path is shown to have a strong influence on the reactions.

Interaction of subway LIM vehicle with ballasted track in polygonal wheel wear development

NASA Astrophysics Data System (ADS)

Li, Ling; Xiao, Xin-Biao; Jin, Xue-Song

2011-04-01

This paper develops a coupled dynamics model for a linear induction motor (LIM) vehicle and a subway track to investigate the influence of polygonal wheels of the vehicle on the dynamic behavior of the system. In the model, the vehicle is modeled as a multi-body system with 35 degrees of freedom. A Timoshenko beam is used to model the rails which are discretely supported by sleepers. The sleepers are modeled as rigid bodies with their vertical, lateral, and rolling motions being considered. In order to simulate the vehicle running along the track, a moving sleeper support model is introduced to simulate the excitation by the discrete sleeper supporters, in which the sleepers are assumed to move backward at a constant speed that is the same as the train speed. The Hertzian contact theory and the Shen-Hedrick-Elkins' model are utilized to deal with the normal dynamic forces and the tangential forces between wheels and rails, respectively. In order to better characterize the linear metro system (LMS), Euler beam theory based on modal superposition method is used to model LIM and RP. The vertical electric magnetic force and the lateral restoring force between the LIM and RP are also taken into consideration. The former has gap-varying nonlinear characteristics, whilst the latter is considered as a constant restoring force of 1 kN. The numerical analysis considers the effect of the excitation due to polygonal wheels on the dynamic behavior of the system at different wear stages, in which the used data regarding the polygonal wear on the wheel tread are directly measured at the subway site.

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

NASA Astrophysics Data System (ADS)

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

2015-06-01

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

Switch Panel wear loading - a parametric study regarding governing train operational factors

NASA Astrophysics Data System (ADS)

Hiensch, E. J. M.; Burgelman, N.

2017-09-01

The acting forces and resulting material degradation at the running surfaces of wheels and rail are determined by vehicle, track, interface and operational characteristics. To effectively manage the experienced wear, plastic deformation and crack development at wheels and rail, the interaction between vehicle and track demands a system approach both in maintenance and in design. This requires insight into the impact of train operational parameters on rail- and wheel degradation, in particular at switches and crossings due to the complex dynamic behaviour of a railway vehicle at a turnout. A parametric study was carried out by means of vehicle-track simulations within the VAMPIRE® multibody simulation software, performing a sensitivity analysis regarding operational factors and their impact on expected switch panel wear loading. Additionally, theoretical concepts were cross-checked with operational practices by means of a case study in response to a dramatic change in lateral rail wear development at specific switches in Dutch track. Data from train operation, track maintenance and track inspection were analysed, providing further insight into the operational dependencies. From the simulations performed in this study, it was found that switch rail lateral wear loading at the diverging route of a 1:9 type turnout is significantly influenced by the level of wheel-rail friction and to a lesser extent by the direction of travel (facing or trailing). The influence of other investigated parameters, being vehicle speed, traction, gauge widening and track layout is found to be small. Findings from the case study further confirm the simulation outcome. This research clearly demonstrates the contribution flange lubrication can have in preventing abnormal lateral wear at locations where the wheel-rail interface is heavily loaded.

Improved LTVMPC design for steering control of autonomous vehicle

NASA Astrophysics Data System (ADS)

Velhal, Shridhar; Thomas, Susy

2017-01-01

An improved linear time varying model predictive control for steering control of autonomous vehicle running on slippery road is presented. Control strategy is designed such that the vehicle will follow the predefined trajectory with highest possible entry speed. In linear time varying model predictive control, nonlinear vehicle model is successively linearized at each sampling instant. This linear time varying model is used to design MPC which will predict the future horizon. By incorporating predicted input horizon in each successive linearization the effectiveness of controller has been improved. The tracking performance using steering with front wheel and braking at four wheels are presented to illustrate the effectiveness of the proposed method.

49 CFR 533.4 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-10-01

... by a manufacturer whose principal place of business is in the United States. 4-wheel drive, general utility vehicle means a 4-wheel drive, general purpose automobile capable of off-highway operation that...

Prediction of the interaction between a simple moving vehicle and an infinite periodically supported rail - Green's functions approach

NASA Astrophysics Data System (ADS)

Mazilu, Traian

2010-09-01

This paper herein describes the interaction between a simple moving vehicle and an infinite periodically supported rail, in order to signalise the basic features of the vehicle/track vibration behaviour in general, and wheel/rail vibration, in particular. The rail is modelled as an infinite Timoshenko beam resting on semi-sleepers via three-directional rail pads and ballast. The time-domain analysis was performed applying Green's matrix of the track method. This method allows taking into account the nonlinearities of the wheel/rail contact and the Doppler effect. The numerical analysis is dedicated to the wheel/rail response due to two types of excitation: the steady-state interaction and rail irregularities. The study points out to certain aspects regarding the parametric resonance, the amplitude-modulated vibration due to corrugation and the Doppler effect.

49 CFR 570.1 - Scope.

Code of Federal Regulations, 2010 CFR

2010-10-01

... systems, steering and suspension systems, and tire and wheel assemblies of motor vehicles in use. ... OF TRANSPORTATION VEHICLE IN USE INSPECTION STANDARDS Vehicles With GVWR of 10,000 Pounds or Less...

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

NASA Technical Reports Server (NTRS)

Frederick, D. K.; Lashmet, P. K.; Sandor, G. N.; Shen, C. N.; Smith, E. V.; Yerazunis, S. W.

1973-01-01

Problems related to the design and control of a mobile planetary vehicle to implement a systematic plan for the exploration of Mars are reported. Problem areas include: vehicle configuration, control, dynamics, systems and propulsion; systems analysis, terrain modeling and path selection; and chemical analysis of specimens. These tasks are summarized: vehicle model design, mathematical model of vehicle dynamics, experimental vehicle dynamics, obstacle negotiation, electrochemical controls, remote control, collapsibility and deployment, construction of a wheel tester, wheel analysis, payload design, system design optimization, effect of design assumptions, accessory optimal design, on-board computer subsystem, laser range measurement, discrete obstacle detection, obstacle detection systems, terrain modeling, path selection system simulation and evaluation, gas chromatograph/mass spectrometer system concepts, and chromatograph model evaluation and improvement.

Utah State University's T2 ODV mobility analysis

NASA Astrophysics Data System (ADS)

Davidson, Morgan E.; Bahl, Vikas; Wood, Carl G.

2000-07-01

In response to ultra-high maneuverability vehicle requirements, Utah State University (USU) has developed an autonomous vehicle with unique mobility and maneuverability capabilities. This paper describes a study of the mobility of the USU T2 Omni-Directional Vehicle (ODV). The T2 vehicle is a mid-scale (625 kg), second-generation ODV mobile robot with six independently driven and steered wheel assemblies. The six wheel, independent steering system is capable of unlimited steering rotation, presenting a unique solution to enhanced vehicle mobility requirements. This mobility study focuses on energy consumption in three basic experiments, comparing two modes of steering: Ackerman and ODV. The experiments are all performed on the same vehicle without any physical changes to the vehicle itself, providing a direct comparison these two steering methodologies. A computer simulation of the T2 mechanical and control system dynamics is described.

Method for controlling a vehicle with two or more independently steered wheels

DOEpatents

Reister, David B.; Unseren, Michael A.

1995-01-01

A method (10) for independently controlling each steerable drive wheel (W.sub.i) of a vehicle with two or more such wheels (W.sub.i). An instantaneous center of rotation target (ICR) and a tangential velocity target (v.sup.G) are inputs to a wheel target system (30) which sends the velocity target (v.sub.i.sup.G) and a steering angle target (.theta..sub.i.sup.G) for each drive wheel (W.sub.i) to a pseudovelocity target system (32). The pseudovelocity target system (32) determines a pseudovelocity target (v.sub.P.sup.G) which is compared to a current pseudovelocity (v.sub.P.sup.m) to determine a pseudovelocity error (.epsilon.). The steering angle targets (.theta..sup.G) and the steering angles (.theta..sup.m) are inputs to a steering angle control system (34) which outputs to the steering angle encoders (36), which measure the steering angles (.theta..sup.m). The pseudovelocity error (.epsilon.), the rate of change of the pseudovelocity error ( ), and the wheel slip between each pair of drive wheels (W.sub.i) are used to calculate intermediate control variables which, along with the steering angle targets (.theta..sup.G) are used to calculate the torque to be applied at each wheel (W.sub.i). The current distance traveled for each wheel (W.sub.i) is then calculated. The current wheel velocities (v.sup.m) and steering angle targets (.theta..sup.G) are used to calculate the cumulative and instantaneous wheel slip (e, ) and the current pseudovelocity (v.sub.P.sup.m).

Thermal signature characteristics of vehicle/terrain interaction disturbances: implications for battlefield vehicle classification.

PubMed

Eastes, John W; Mason, George L; Kusinger, Alan E

2004-05-01

Thermal emissivity spectra (8-14 microm) of track impressions/background were determined in conjunction with operation of six military vehicle types, T-72 and M1 Tanks, an M2 Bradley Fighting Vehicle, a 5-ton truck, a D7 tractor, and a High Mobility Multipurpose Wheeled Vehicle (HMMWV), over diverse soil surfaces to determine if vehicle type could be related to track thermal signatures. Results suggest soil compaction and fragmentation/pulverization are primary parameters affecting track signatures and that soil and vehicle/terrain-contact type determine which parameter dominates. Steel-tracked vehicles exert relatively low ground-contact pressure but tend to fragment/pulverize soil more so than do rubber-tired vehicles, which tend mainly to compact. In quartz-rich, lean clay soil tracked vehicles produced impressions with spectral contrast of the quartz reststrahlen features decreased from that of the background. At the same time, 5-ton truck tracks exhibited increased contrast on the same surface, suggesting that steel tracks fragmented soil while rubber tires mainly produced compaction. The structure of materials such as sand and moist clay-rich river sediment makes them less subject to further fragmentation/pulverization; thus, compaction was the main factor affecting signatures in these media, and both tracked and wheeled vehicles created impressions with increased spectral contrast on these surfaces. These results suggest that remotely sensed thermal signatures could differentiate tracked and wheeled vehicles on terrain in many areas of the world of strategic interest. Significant applications include distinguishing visually/spectrally identical lightweight decoys from actual threat vehicles.

Estimation of wheel-rail friction for vehicle certification

NASA Astrophysics Data System (ADS)

Petrov, Vladislav; Berg, Mats; Persson, Ingemar

2014-08-01

In certification of new rail vehicles with respect to running characteristics, a wide variety of operating conditions needs to be considered. However, in associated test runs the wheel-rail friction condition is difficult to handle because the friction coefficient needs to be fairly high and the friction is also generally hard to assess. This is an issue that has been studied in the European project DynoTRAIN and part of the results is presented in this paper. More specifically, an algorithm for estimating the wheel-rail friction coefficient at vehicle certification tests is proposed. Owing to lack of some measurement results, the algorithm here is evaluated in a simulation environment which is also an important step towards practical implementation. A quality measure of the friction estimate is suggested in terms of estimated wheel-rail spin and total creep. It is concluded that, tentatively, the total creep should exceed 0.006 and the spin should be less than 1.0 m-1 for the algorithm to give a good friction estimate. Sensitivity analysis is carried out to imitate measurement errors, but should be expanded in further work.

76 FR 73771 - Denial of Motor Vehicle Defect Petition, DP10-002

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-29

...This notice describes the reasons for denying a petition (DP10-002) submitted to NHTSA under 49 U.S.C. Subtitle B, Chapter V, Part 552, Subpart A, requesting that the agency conduct ``an investigation of defective products manufactured by Dayton Wheel Concepts, Inc. (`Dayton Wheel' and American Wire Wheel, LLC (`American Wheel').'' The petition listed the allegedly defective products and the alleged defect (which varied by allegedly defective product).

Vehicle Mobility Assessment for Project Wheels Study Group

DTIC Science & Technology

1972-07-01

cash savings p’Asible through the elimination of special military automotive features, such as front-wheel 1 Idrive , or the use of commercial vehicles...E12. (12) off-,,,d mobiliY profile 4x4 0ruck, c 2Z4< 20 ,ernn It Iot "- III IIIII III I I I IIII A%. West Germany 0A * s ps ArizonazD • Ř’.. • D

Combustion powered linear actuator

DOEpatents

Fischer, Gary J.

2007-09-04

The present invention provides robotic vehicles having wheeled and hopping mobilities that are capable of traversing (e.g. by hopping over) obstacles that are large in size relative to the robot and, are capable of operation in unpredictable terrain over long range. The present invention further provides combustion powered linear actuators, which can include latching mechanisms to facilitate pressurized fueling of the actuators, as can be used to provide wheeled vehicles with a hopping mobility.

A survey of wheel-rail contact models for rail vehicles

NASA Astrophysics Data System (ADS)

Meymand, Sajjad Z.; Keylin, Alexander; Ahmadian, Mehdi

2016-03-01

Accurate and efficient contact models for wheel-rail interaction are essential for the study of the dynamic behaviour of a railway vehicle. Assessment of the contact forces and moments, as well as contact geometry provide a fundamental foundation for such tasks as design of braking and traction control systems, prediction of wheel and rail wear, and evaluation of ride safety and comfort. This paper discusses the evolution and the current state of the theories for solving the wheel-rail contact problem for rolling stock. The well-known theories for modelling both normal contact (Hertzian and non-Hertzian) and tangential contact (Kalker's linear theory, FASTSIM, CONTACT, Polach's theory, etc.) are reviewed. The paper discusses the simplifying assumptions for developing these models and compares their functionality. The experimental studies for evaluation of contact models are also reviewed. This paper concludes with discussing open areas in contact mechanics that require further research for developing better models to represent the wheel-rail interaction.

Cross-Coupled Control for All-Terrain Rovers

PubMed Central

Reina, Giulio

2013-01-01

Mobile robots are increasingly being used in challenging outdoor environments for applications that include construction, mining, agriculture, military and planetary exploration. In order to accomplish the planned task, it is critical that the motion control system ensure accuracy and robustness. The achievement of high performance on rough terrain is tightly connected with the minimization of vehicle-terrain dynamics effects such as slipping and skidding. This paper presents a cross-coupled controller for a 4-wheel-drive/4-wheel-steer robot, which optimizes the wheel motors' control algorithm to reduce synchronization errors that would otherwise result in wheel slip with conventional controllers. Experimental results, obtained with an all-terrain rover operating on agricultural terrain, are presented to validate the system. It is shown that the proposed approach is effective in reducing slippage and vehicle posture errors. PMID:23299625

Electronic 4-wheel drive control device

NASA Technical Reports Server (NTRS)

Hayato, S.; Takanori, S.; Shigeru, H.; Tatsunori, S.

1984-01-01

The internal rotation torque generated during operation of a 4-wheel drive vehicle is reduced using a control device whose clutch is attached to one part of the rear-wheel drive shaft. One torque sensor senses the drive torque associated with the rear wheel drive shaft. A second sensor senses the drive torque associated with the front wheel drive shaft. Revolution count sensors sense the revolutions of each drive shaft. By means of a microcomputer, the engagement of the clutch is changed to insure that the ratio of the torque sensors remains constant.

77 FR 74736 - Petition for Waiver of Compliance

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-17

... deficiency is a technical term describing the imbalance of inner and outer wheel loads when a rail vehicle... rail is elevated above the inner rail), the loads on both inner and outer wheels will be equal, i.e... than the balance speed, the centrifugal force will cause the outer wheel load to increase and the inner...

Effect of suspension kinematic on 14 DOF vehicle model

NASA Astrophysics Data System (ADS)

Wongpattananukul, T.; Chantharasenawong, C.

2017-12-01

Computer simulations play a major role in shaping modern science and engineering. They reduce time and resource consumption in new studies and designs. Vehicle simulations have been studied extensively to achieve a vehicle model used in minimum lap time solution. Simulation result accuracy depends on the abilities of these models to represent real phenomenon. Vehicles models with 7 degrees of freedom (DOF), 10 DOF and 14 DOF are normally used in optimal control to solve for minimum lap time. However, suspension kinematics are always neglected on these models. Suspension kinematics are defined as wheel movements with respect to the vehicle body. Tire forces are expressed as a function of wheel slip and wheel position. Therefore, the suspension kinematic relation is appended to the 14 DOF vehicle model to investigate its effects on the accuracy of simulate trajectory. Classical 14 DOF vehicle model is chosen as baseline model. Experiment data is collected from formula student style car test runs as baseline data for simulation and comparison between baseline model and model with suspension kinematic. Results show that in a single long turn there is an accumulated trajectory error in baseline model compared to model with suspension kinematic. While in short alternate turns, the trajectory error is much smaller. These results show that suspension kinematic had an effect on the trajectory simulation of vehicle. Which optimal control that use baseline model will result in inaccuracy control scheme.

Analysis and control of high-speed wheeled vehicles

NASA Astrophysics Data System (ADS)

Velenis, Efstathios

In this work we reproduce driving techniques to mimic expert race drivers and obtain the open-loop control signals that may be used by auto-pilot agents driving autonomous ground wheeled vehicles. Race drivers operate their vehicles at the limits of the acceleration envelope. An accurate characterization of the acceleration capacity of the vehicle is required. Understanding and reproduction of such complex maneuvers also require a physics-based mathematical description of the vehicle dynamics. While most of the modeling issues of ground-vehicles/automobiles are already well established in the literature, lack of understanding of the physics associated with friction generation results in ad-hoc approaches to tire friction modeling. In this work we revisit this aspect of the overall vehicle modeling and develop a tire friction model that provides physical interpretation of the tire forces. The new model is free of those singularities at low vehicle speed and wheel angular rate that are inherent in the widely used empirical static models. In addition, the dynamic nature of the tire model proposed herein allows the study of dynamic effects such as transients and hysteresis. The trajectory-planning problem for an autonomous ground wheeled vehicle is formulated in an optimal control framework aiming to minimize the time of travel and maximize the use of the available acceleration capacity. The first approach to solve the optimal control problem is using numerical techniques. Numerical optimization allows incorporation of a vehicle model of high fidelity and generates realistic solutions. Such an optimization scheme provides an ideal platform to study the limit operation of the vehicle, which would not be possible via straightforward simulation. In this work we emphasize the importance of online applicability of the proposed methodologies. This underlines the need for optimal solutions that require little computational cost and are able to incorporate real, unpredictable environments. A semi-analytic methodology is developed to generate the optimal velocity profile for minimum time travel along a prescribed path. The semi-analytic nature ensures minimal computational cost while a receding horizon implementation allows application of the methodology in uncertain environments. Extensions to increase fidelity of the vehicle model are finally provided.

Optimal control of mode transition for four-wheel-drive hybrid electric vehicle with dry dual-clutch transmission

NASA Astrophysics Data System (ADS)

Zhao, Zhiguo; Lei, Dan; Chen, Jiayi; Li, Hangyu

2018-05-01

When the four-wheel-drive hybrid electric vehicle (HEV) equipped with a dry dual clutch transmission (DCT) is in the mode transition process from pure electrical rear wheel drive to front wheel drive with engine or hybrid drive, the problem of vehicle longitudinal jerk is prominent. A mode transition robust control algorithm which resists external disturbance and model parameter fluctuation has been developed, by taking full advantage of fast and accurate torque (or speed) response of three electrical power sources and getting the clutch of DCT fully involved in the mode transition process. Firstly, models of key components of driveline system have been established, and the model of five-degrees-of-freedom vehicle longitudinal dynamics has been built by using a Uni-Tire model. Next, a multistage optimal control method has been produced to realize the decision of engine torque and clutch-transmitted torque. The sliding-mode control strategy for measurable disturbance has been proposed at the stage of engine speed dragged up. Meanwhile, the double tracking control architecture that integrates the model calculating feedforward control with H∞ robust feedback control has been presented at the stage of speed synchronization. Finally, the results from Matlab/Simulink software and hardware-in-the-loop test both demonstrate that the proposed control strategy for mode transition can not only coordinate the torque among different power sources and clutch while minimizing vehicle longitudinal jerk, but also provide strong robustness to model uncertainties and external disturbance.

Curiosity Wheel During Descent

NASA Image and Video Library

2012-08-07

This color thumbnail image was obtained by NASA Curiosity rover illustrating the first appearance of the left front wheel of the Curiosity rover after deployment of the suspension system as the vehicle was about to touch down on Mars.

Interaction of In-wheel permanent magnet synchronous motor with tire dynamics

NASA Astrophysics Data System (ADS)

Song, Ziyou; Li, Jianqiu; Wei, Yintao; Xu, Liangfei; Ouyang, Minggao

2015-05-01

Drive wheel systems combined with the in-wheel permanent magnet synchronous motor (I-PMSM) and the tire are highly electromechanical-coupled. However, the deformation dynamics of this system, which may influence the system performance, is neglected in most existing literatures. For this reason, a deformable tire and a detailed I-PMSM are modeled using Matlab/Simulink. Furthermore, the influence of tire/road contact interface is accurately described by the non-linear relaxation length-based model and magic formula pragmatic model. The drive wheel model used in this paper is closer to that of a real tire in contrast to the rigid tire model which is widely used. Based on the near-precise model mentioned above, the sensitivity of the dynamic tire and I-PMSM parameters to the relative error of slip ratio estimation is analyzed. Additionally, the torsional and longitudinal vibrations of the drive wheel are presented both in time and frequency domains when a quarter vehicle is started under conditions of a specific torque curve, which includes an abrupt torque change from 30 N · m to 200 N · m. The parameters sensitivity on drive wheel vibrations is also studied, and the parameters include the mass distribution ratio of tire, the tire torsional stiffness, the tire damping coefficient, and the hysteresis band of the PMSM current control algorithm. Finally, different target torque curves are compared in the simulation, which shows that the estimation error of the slip ratio gets violent, and the longitudinal force includes more fluctuation components with the increasing change rate of the torque. This paper analyzes the influence of the drive wheel deformation on the vehicle dynamic control, and provides useful information regarding the electric vehicle traction control.

Crack detection in a wheel end spindle using wave propagation via modal impacts and piezo actuation

NASA Astrophysics Data System (ADS)

Ackers, Spencer; Evans, Ronald; Johnson, Timothy; Kess, Harold; White, Jonathan; Adams, Douglas E.; Brown, Pam

2006-03-01

This research demonstrates two methodologies for detecting cracks in a metal spindle housed deep within a vehicle wheel end assembly. First, modal impacts are imposed on the hub of the wheel in the longitudinal direction to produce broadband elastic wave excitation spectra out to 7000 Hz. The response data on the flange is collected using 3000 Hz bandwidth accelerometers. It is shown using frequency response analysis that the crack produces a filter, which amplifies the elastic response of the surrounding components of the wheel assembly. Experiments on wheel assemblies mounted on the vehicle with the vehicle lifted off the ground are performed to demonstrate that the modal impact method can be used to nondestructively evaluate cracks of varying depths despite sources of variability such as the half shaft angular position relative to the non-rotating spindle. Second, an automatic piezo-stack actuator is utilized to excite the wheel hub with a swept sine signal extending from 20 kHz. Accelerometers are then utilized to measure the response on the flange. It is demonstrated using frequency response analysis that the crack filters waves traveling from the hub to the flange. A simple finite element model is used to interpret the experimental results. Challenges discussed include variability from assembly to assembly, the variability in each assembly, and the high amount of damping present in each assembly due to the transmission gearing, lubricant, and other components in the wheel end. A two-channel measurement system with a graphical user interface for detecting cracks was also developed and a procedure was created to ensure that operators properly perform the test.

5 CFR 930.102 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-01-01

... motor vehicle to properly carry out his or her assigned duties. Motor vehicle means a vehicle designed... vehicle (a) designed or used for military field training, combat, or tactical purposes; (b) used principally within the confines of a regularly established military post, camp, or depot; or (c) regularly...

5 CFR 930.102 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-01-01

... motor vehicle to properly carry out his or her assigned duties. Motor vehicle means a vehicle designed... vehicle (a) designed or used for military field training, combat, or tactical purposes; (b) used principally within the confines of a regularly established military post, camp, or depot; or (c) regularly...

5 CFR 930.102 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-01-01

... motor vehicle to properly carry out his or her assigned duties. Motor vehicle means a vehicle designed... vehicle (a) designed or used for military field training, combat, or tactical purposes; (b) used principally within the confines of a regularly established military post, camp, or depot; or (c) regularly...

5 CFR 930.102 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-01-01

... motor vehicle to properly carry out his or her assigned duties. Motor vehicle means a vehicle designed... vehicle (a) designed or used for military field training, combat, or tactical purposes; (b) used principally within the confines of a regularly established military post, camp, or depot; or (c) regularly...

5 CFR 930.102 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... motor vehicle to properly carry out his or her assigned duties. Motor vehicle means a vehicle designed... vehicle (a) designed or used for military field training, combat, or tactical purposes; (b) used principally within the confines of a regularly established military post, camp, or depot; or (c) regularly...

Device for reducing vehicle aerodynamic resistance

DOEpatents

Graham, Sean C.

2006-08-22

A device for reducing vehicle aerodynamic resistance for vehicles having a generally rectangular body disposed above rear wheels, comprising a plurality of load bearing struts attached to the bottom of the rectangular body adjacent its sides, a plurality of opposing flat sheets attached to the load bearing struts, and angled flaps attached to the lower edge of the opposing sheets defining an obtuse angle with the opposing flat sheets extending inwardly with respect to the sides of the rectangular body to a predetermined height above the ground, which, stiffen the opposing flat sheets, bend to resist damage when struck by the ground, and guide airflow around the rear wheels of the vehicle to reduce its aerodynamic resistance when moving.

GOAT (goes over all terrain) vehicle: a scaleable robotic vehicle

NASA Astrophysics Data System (ADS)

Dodson, Michael G.; Owsley, Stanley L.; Moorehead, Stewart J.

2003-09-01

Many of the potential applications of mobile robots require a small to medium sized vehicle that is capable of traversing large obstacles and rugged terrain. Search and rescue operations require a robot small enough to drive through doorways, yet capable enough to surmount rubble piles and stairs. This paper presents the GOAT (Goes Over All Terrain) vehicle, a medium scale robot which incorporates a novel configuration which puts the drive wheels on the ends of actuated arms. This allows GOAT to adjust body height and posture and combines the benefits of legged locomotion with the ease of wheeled driving. The paper presents the design of the GOAT and the results of prototype construction and initial testing.

Vehicle handling and stability control by the cooperative control of 4WS and DYC

NASA Astrophysics Data System (ADS)

Shen, Huan; Tan, Yun-Sheng

2017-07-01

This paper proposes an integrated control system that cooperates with the four-wheel steering (4WS) and direct yaw moment control (DYC) to improve the vehicle handling and stability. The design works of the four-wheel steering and DYC control are based on sliding mode control. The integration control system produces the suitable 4WS angle and corrective yaw moment so that the vehicle tracks the desired yaw rate and sideslip angle. Considering the change of the vehicle longitudinal velocity that means the comfort of driving conditions, both the driving torque and braking torque are used to generate the corrective yaw moment. Simulation results show the effectiveness of the proposed control algorithm.

Development of a Computerized Data Base to Monitor Wheeled Vehicle Corrosion

DTIC Science & Technology

1989-10-01

the region which corrodes. This potential difference , or voltage of these little batteries or cells, is due to the difference in the oxygen...availability at the point of attack. Differential aeration cells occur at all places where there is a difference in the availability of oxygen and can only...program is actually an evaluation of the various corrosion prevention systems and methods which were applied to the wheeled vehicles when they were

Modernisation of a test rig for determination of vehicle shock absorber characteristics by considering vehicle suspension elements and unsprung masses

NASA Astrophysics Data System (ADS)

Maniowski, M.; Para, S.; Knapczyk, M.

2016-09-01

This paper presents a modernization approach of a standard test bench for determination of damping characteristics of automotive shock absorbers. It is known that the real-life work conditions of wheel-suspension dampers are not easy to reproduce in laboratory conditions, for example considering a high frequency damper response or a noise emission. The proposed test bench consists of many elements from a real vehicle suspension. Namely, an original tyre-wheel with additional unsprung mass, a suspension spring, an elastic top mount, damper bushings and a simplified wheel guiding mechanism. Each component was tested separately in order to identify its mechanical characteristics. The measured data serve as input parameters for a numerical simulation of the test bench behaviour by using a vibratory model with 3 degrees of freedom. Study on the simulation results and the measurements are needed for further development of the proposed test bench.

A fuzzy logic sliding mode controlled electronic differential for a direct wheel drive EV

NASA Astrophysics Data System (ADS)

Ozkop, Emre; Altas, Ismail H.; Okumus, H. Ibrahim; Sharaf, Adel M.

2015-11-01

In this study, a direct wheel drive electric vehicle based on an electronic differential system with a fuzzy logic sliding mode controller (FLSMC) is studied. The conventional sliding surface is modified using a fuzzy rule base to obtain fuzzy dynamic sliding surfaces by changing its slopes using the global error and its derivative in a fuzzy logic inference system. The controller is compared with proportional-integral-derivative (PID) and sliding mode controllers (SMCs), which are usually preferred to be used in industry. The proposed controller provides robustness and flexibility to direct wheel drive electric vehicles. The fuzzy logic sliding mode controller, electronic differential system and the overall electrical vehicle mechanism are modelled and digitally simulated by using the Matlab software. Simulation results show that the system with FLSMC has better efficiency and performance compared to those of PID and SMCs.

[Atypical injury pattern of a pedestrian run over by an unimog in the epigastric region].

PubMed

Guddat, Saskia Sabrina; Müller-Rakow, Peter; Wiedmann, Peter; Püschel, Klaus; Tsokos, Michael

2007-01-01

Strongly intoxicated, a 37-year-old man fell in front of the right back wheel of an emergency vehicle (MB Unimog) and was run over according to eye witnesses. He died in hospital shortly afterwards. The autopsy revealed that he bled to death from a traumatic liver rupture (bursting of the right hepatic lobe and severing of a piece of tissue measuring 17 x 8 x 4 cm). There were no injuries classicaly seen in victims run over by a car. The atypical injury findings in this case are due to the special features of the accident vehicle: The Unimog (an all-wheel vehicle with a fixed rear axle and flat coils) struck the right side of the body lying on the street with its rear wheel and was then lifted over the body by its fixed axle without touching the left side.

Durability Characteristics Analysis of Plastic Worm Wheel with Glass Fiber Reinforced Polyamide.

PubMed

Kim, Gun-Hee; Lee, Jeong-Won; Seo, Tae-Il

2013-05-10

Plastic worm wheel is widely used in the vehicle manufacturing field because it is favorable for weight lightening, vibration and noise reduction, as well as corrosion resistance. However, it is very difficult for general plastics to secure the mechanical properties that are required for vehicle gears. If the plastic resin is reinforced by glass fiber in the fabrication process of plastic worm wheel, it is possible to achieve the mechanical properties of metallic material levels. In this study, the mechanical characteristic analysis of the glass-reinforced plastic worm wheel, according to the contents of glass fiber, is performed by analytic and experimental methods. In the case of the glass fiber-reinforced resin, the orientation and contents of glass fibers can influence the mechanical properties. For the characteristic prediction of plastic worm wheel, computer-aided engineering (CAE) analysis processes such as structural and injection molding analysis were executed with the polyamide resin reinforcement glass fiber (25 wt %, 50 wt %). The injection mold for fabricating the prototype plastic worm wheel was designed and made to reflect the CAE analysis results. Finally, the durability of prototype plastic worm wheel fabricated by the injection molding process was evaluated by the experimental method and the characteristics according to the glass fiber contents.

Energy-Absorbing, Lightweight Wheels

NASA Technical Reports Server (NTRS)

Waydo, Peter

2003-01-01

Improved energy-absorbing wheels are under development for use on special-purpose vehicles that must traverse rough terrain under conditions (e.g., extreme cold) in which rubber pneumatic tires would fail. The designs of these wheels differ from those of prior non-pneumatic energy-absorbing wheels in ways that result in lighter weights and more effective reduction of stresses generated by ground/wheel contact forces. These wheels could be made of metals and/or composite materials to withstand the expected extreme operating conditions. As shown in the figure, a wheel according to this concept would include an isogrid tire connected to a hub via spring rods. The isogrid tire would be a stiff, lightweight structure typically made of aluminum. The isogrid aspect of the structure would both impart stiffness and act as a traction surface. The hub would be a thin-walled body of revolution having a simple or compound conical or other shape chosen for structural efficiency. The spring rods would absorb energy and partially isolate the hub and the supported vehicle from impact loads. The general spring-rod configuration shown in the figure was chosen because it would distribute contact and impact loads nearly evenly around the periphery of the hub, thereby helping to protect the hub against damage that would otherwise be caused by large loads concentrated onto small portions of the hub.

Durability Characteristics Analysis of Plastic Worm Wheel with Glass Fiber Reinforced Polyamide

PubMed Central

Kim, Gun-Hee; Lee, Jeong-Won; Seo, Tae-Il

2013-01-01

Plastic worm wheel is widely used in the vehicle manufacturing field because it is favorable for weight lightening, vibration and noise reduction, as well as corrosion resistance. However, it is very difficult for general plastics to secure the mechanical properties that are required for vehicle gears. If the plastic resin is reinforced by glass fiber in the fabrication process of plastic worm wheel, it is possible to achieve the mechanical properties of metallic material levels. In this study, the mechanical characteristic analysis of the glass-reinforced plastic worm wheel, according to the contents of glass fiber, is performed by analytic and experimental methods. In the case of the glass fiber-reinforced resin, the orientation and contents of glass fibers can influence the mechanical properties. For the characteristic prediction of plastic worm wheel, computer-aided engineering (CAE) analysis processes such as structural and injection molding analysis were executed with the polyamide resin reinforcement glass fiber (25 wt %, 50 wt %). The injection mold for fabricating the prototype plastic worm wheel was designed and made to reflect the CAE analysis results. Finally, the durability of prototype plastic worm wheel fabricated by the injection molding process was evaluated by the experimental method and the characteristics according to the glass fiber contents. PMID:28809248

Fractional Control of An Active Four-wheel-steering Vehicle

NASA Astrophysics Data System (ADS)

Wang, Tianting; Tong, Jun; Chen, Ning; Tian, Jie

2018-03-01

A four-wheel-steering (4WS) vehicle model and reference model with a drop filter are constructed. The decoupling of 4WS vehicle model is carried out. And a fractional PIλDμ controller is introduced into the decoupling strategy to reduce the effects of the uncertainty of the vehicle parameters as well as the unmodelled dynamics on the system performance. Based on optimization techniques, the design of fractional controller are obtained to ensure the robustness of 4WS vehicle during the special range of frequencies through proper choice of the constraints. In order to compare with fractional robust controller, an optimal controller for the same vehicle is also designed. The simulations of the two control systems are carried out and it reveals that the decoupling and fractional robust controller is able to make vehicle model trace the reference model very well with better robustness.

Vehicle lift-off modelling and a new rollover detection criterion

NASA Astrophysics Data System (ADS)

Mashadi, Behrooz; Mostaghimi, Hamid

2017-05-01

The modelling and development of a general criterion for the prediction of rollover threshold is the main purpose of this work. Vehicle dynamics models after the wheels lift-off and when the vehicle moves on the two wheels are derived and the governing equations are used to develop the rollover threshold. These models include the properties of the suspension and steering systems. In order to study the stability of motion, the steady-state solutions of the equations of motion are carried out. Based on the stability analyses, a new relation is obtained for the rollover threshold in terms of measurable response parameters. The presented criterion predicts the best time for the prevention of the vehicle rollover by applying a correcting moment. It is shown that the introduced threshold of vehicle rollover is a proper state of vehicle motion that is best for stabilising the vehicle with a low energy requirement.

Road simulation for four-wheel vehicle whole input power spectral density

NASA Astrophysics Data System (ADS)

Wang, Jiangbo; Qiang, Baomin

2017-05-01

As the vibration of running vehicle mainly comes from road and influence vehicle ride performance. So the road roughness power spectral density simulation has great significance to analyze automobile suspension vibration system parameters and evaluate ride comfort. Firstly, this paper based on the mathematical model of road roughness power spectral density, established the integral white noise road random method. Then in the MATLAB/Simulink environment, according to the research method of automobile suspension frame from simple two degree of freedom single-wheel vehicle model to complex multiple degrees of freedom vehicle model, this paper built the simple single incentive input simulation model. Finally the spectrum matrix was used to build whole vehicle incentive input simulation model. This simulation method based on reliable and accurate mathematical theory and can be applied to the random road simulation of any specified spectral which provides pavement incentive model and foundation to vehicle ride performance research and vibration simulation.

Analysis and design of a capsule landing system and surface vehicle control system for Mars exporation

NASA Technical Reports Server (NTRS)

Frederick, D. K.; Lashmet, P. K.; Sandor, G. N.; Shen, C. N.; Smith, E. J.; Yerazunis, S. W.

1972-01-01

The problems related to the design and control of a mobile planetary vehicle to implement a systematic plan for the exploration of Mars were investigated. Problem areas receiving attention include: vehicle configuration, control, dynamics, systems and propulsion; systems analysis; navigation, terrain modeling and path selection; and chemical analysis of specimens. The following specific tasks were studied: vehicle model design, mathematical modeling of dynamic vehicle, experimental vehicle dynamics, obstacle negotiation, electromechanical controls, collapsibility and deployment, construction of a wheel tester, wheel analysis, payload design, system design optimization, effect of design assumptions, accessory optimal design, on-board computer subsystem, laser range measurement, discrete obstacle detection, obstacle detection systems, terrain modeling, path selection system simulation and evaluation, gas chromatograph/mass spectrometer system concepts, chromatograph model evaluation and improvement and transport parameter evaluation.

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

NASA Technical Reports Server (NTRS)

Frederick, D. K.; Lashmet, P. K.; Sandor, G. N.; Shen, C. N.; Smith, E. J.; Yerazunis, S. W.

1972-01-01

Investigation of problems related to the design and control of a mobile planetary vehicle to implement a systematic plan for the exploration of Mars has been undertaken. Problem areas receiving attention include: vehicle configuration, control, dynamics, systems and propulsion; systems analysis; terrain modeling and path selection; and chemical analysis of specimens. The following specific tasks have been under study: vehicle model design, mathematical modeling of a dynamic vehicle, experimental vehicle dynamics, obstacle negotiation, electromechanical controls, collapsibility and deployment, construction of a wheel tester, wheel analysis, payload design, system design optimization, effect of design assumptions, accessory optimal design, on-board computer sybsystem, laser range measurement, discrete obstacle detection, obstacle detection systems, terrain modeling, path selection system simulation and evaluation, gas chromatograph/mass spectrometer system concepts, chromatograph model evaluation and improvement.

Lunar material transport vehicle

NASA Technical Reports Server (NTRS)

Fisher, Charles D.; Lyons, Douglas; Wilkins, W. Allen, Jr.; Whitehead, Harry C., Jr.

1988-01-01

The proposed vehicle, the Lunar Material Transport Vehicle (LMTV), has a mission objective of efficient lunar soil material transport. The LMTV was designed to meet a required set of performance specifications while operating under a given set of constraints. The LMTV is essentially an articulated steering, double-ended dump truck. The vehicle moves on four wheels and has two identical chassis halves. Each half consists of a chassis frame, a material bucket, two wheels with integral curvilinear synchronous motors, a fuel cell and battery arrangement, an electromechanically actuated dumping mechanism, and a powerful microprocessor. The vehicle, as designed, is capable of transporting up to 200 cu ft of material over a one mile round trip per hour. The LMTV is capable of being operated from a variety of sources. The vehicle has been designed as simply as possible with attention also given to secondary usage of components.

Maritime Tactical Unmanned Aerial Systems (TUAS) in Navy Strike Groups Can Improve Maritime Domain Awareness for the Operational Commander

DTIC Science & Technology

2008-10-31

Proposal, staff study, 5 September 2007. 4 Thomas H. Kean, and Lee Hamilton. The 9/11 Commission Report: Final Report of the National...January 2008. http://www.cnaf.navy.mil/nae/main.asp?ItemID=12.   41  Tim Dunigan, “Vertical Take-off and Landing Tactical Unmanned Air Vehicle...September 2007. Berner , Robert A. The Effective Use of Multiple Unmanned Aerial Vehicles in Surface Search and Control. Ft. Belvoir: Defense

Alternative Fuels Data Center

Science.gov Websites

Low-Speed Vehicle Definition A low-speed vehicle is defined as a four wheeled vehicle that has a maximum speed greater than 20 miles per hour (mph) but not more than 25 mph and has a gross vehicle weight

The behaviour of a vehicle’s suspension system on dynamic testing conditions

NASA Astrophysics Data System (ADS)

Mihon, L.; Lontiş, N.; Deac, S.

2018-01-01

The paper presents a car suspension’s behaviour on dynamic testing conditions through theoretical and mathematical simulation on specific model, on the single traction wheel, according to the real vehicle and by experiment on the test bench by reproducing the road’s geometry and vehicle’s speed and measuring the acceleration and damping response of the suspension system on that wheel. There are taking in consideration also the geometry and properties of the tyre-wheel model and physical wheel’s properties. The results are important due to the suspension’s model properties which allows to extend the theory and applications to the whole vehicle for improving the vehicle’s dynamics.

Alternative Fuels Data Center

Science.gov Websites

Autonomous Vehicle Regulations and Committee A fully autonomous vehicle is defined as a vehicle tactical control functions of the vehicle at any time.Effective December 1, 2017, the operator of a fully autonomous vehicle is not required to be licensed to operate a motor vehicle. A person may operate a fully

Bidirectional drive and brake mechanism

NASA Technical Reports Server (NTRS)

Swan, Scott A. (Inventor)

1991-01-01

A space transport vehicle is disclosed as including a body which is arranged to be movably mounted on an elongated guide member disposed in outer space and driven therealong. A drive wheel is mounted on a drive shaft and arranged to be positioned in rolling engagement with the elongated guide carrying the vehicle. A brake member is arranged on the drive shaft for movement into and out of engagement with an adjacent surface of the drive wheel. An actuator is mounted on the body to be manually moved back and forth between spaced positions in an arc of movement. A ratchet-and-pawl mechanism is arranged to operate upon movements of the actuator in one direction between first and second positions for coupling the actuator to the drive wheel to incrementally rotate the wheel in one rotational direction and to operate upon movements of the actuator in the opposite direction for uncoupling the actuator from the wheel. The brake member is threadedly coupled to the drive shaft in order that the brake member will be operated only when the actuator is moved on beyond its first and second positions for shifting the brake member along the drive shaft and into frictional engagement with the adjacent surface on the drive wheel.

On use of characteristic wavelengths of track irregularities to predict track portions with deteriorated wheel/rail forces

NASA Astrophysics Data System (ADS)

Xu, Lei; Zhai, Wanming; Chen, Zhaowei

2018-05-01

The dynamic performance of the railway vehicles and the guiding tracks is mainly governed by the wheel-rail interactions, particularly in cases of track irregularities. In this work, a united model was developed to investigate the track portions subject to violent wheel/rail forces triggered by track irregularities at middle-low frequencies. In the modeling procedures, a time-frequency unification method combining wavelet transform and Wigner-Ville distribution for characterizing time-frequency characteristics of track irregularities and a three-dimensional nonlinear model for describing vehicle-track interaction signatures were developed and coupled, based on which the method for predicting track portions subject to deteriorated wheel/rail forces was proposed. The theoretical models developed in this paper were comprehensively validated by numerical investigations. The significance of this present study mainly lies on offering a new path to establish correlation and realize mutual prediction between track irregularity and railway system dynamics.

CO2 emission benefit of diesel (versus gasoline) powered vehicles.

PubMed

Sullivan, J L; Baker, R E; Boyer, B A; Hammerle, R H; Kenney, T E; Muniz, L; Wallington, T J

2004-06-15

Concerns regarding global warming have increased the pressure on automobile manufacturers to decrease emissions of CO2 from vehicles. Diesel vehicles have higher fuel economy and lower CO2 emissions than their gasoline counterparts. Increased penetration of diesel powered vehicles into the market is a possible transition strategy toward a more sustainable transportation system. To facilitate discussions regarding the relative merits of diesel vehicles it is important to have a clear understanding of their CO2 emission benefits. Based on European diesel and gasoline certification data, this report quantifies such CO2 reduction opportunities for cars and light duty trucks in today's vehicles and those in the year 2015. Overall, on a well-to-wheels per vehicle per mile basis, the CO2 reduction opportunity for today's vehicles is approximately 24-33%. We anticipate that the gap between diesel and gasoline well-to-wheel vehicle CO2 emissions will decrease to approximately 14-27% by the year 2015.

Optimal CV-22 Centralized Intermediate Repair Facility Locations and Parts Repair

DTIC Science & Technology

2009-06-01

and Reorder Point for TEWS ............................ 36 Table 8. Excel Model for Safety Stock and Reorder Point for FADEC ...Digital Engine Control ( FADEC ) Main Wheel Assembly Blade Fold System Landing Gear Control Panel Drive System Interface Unit Main Landing Gear...Radar 4 Forward Looking Infrared System (FLIR) 4 Tactical Electronic Warfare System (TEWS) 1 Full Authority Digital Engine Control ( FADEC ) 2 Blade

Applied design methodology for lunar rover elastic wheel

NASA Astrophysics Data System (ADS)

Cardile, Diego; Viola, Nicole; Chiesa, Sergio; Rougier, Alessandro

2012-12-01

In recent years an increasing interest in the Moon surface operations has been experienced. In the future robotic and manned missions of Moon surface exploration will be fundamental in order to lay the groundwork for more ambitious space exploration programs. Surface mobility systems will be the key elements to ensure an efficient and safe Moon exploration. Future lunar rovers are likely to be heavier and able to travel longer distances than the previously developed Moon rover systems. The Lunar Roving Vehicle (LRV) is the only manned rover, which has so far been launched and used on the Moon surface. Its mobility system included flexible wheels that cannot be scaled to the heavier and longer range vehicles. Thus the previously developed wheels are likely not to be suitable for the new larger vehicles. Taking all these considerations into account, on the basis of the system requirements and assumptions, several wheel concepts have been discussed and evaluated through a trade-off analysis. Semi-empirical equations have been utilized to predict the wheel geometrical characteristics, as well as to estimate the motion resistances and the ability of the system to generate thrust. A numerical model has also been implemented, in order to define more into the details the whole wheel design, in terms of wheel geometry and physical properties. As a result of the trade-off analysis, the ellipse wheel concept has shown the best behavior in terms of stiffness, mass budget and dynamic performance. The results presented in the paper have been obtained in cooperation with Thales Alenia Space-Italy and Sicme motori, in the framework of a regional program called STEPS . STEPS-Sistemi e Tecnologie per l'EsPlorazione Spaziale is a research project co-financed by Piedmont Region and firms and universities of the Piedmont Aerospace District in the ambit of the P.O.R-F.E.S.R. 2007-2013 program.

Measurement of Micro Vibration of Car by Piezoelectric Ceramics

NASA Astrophysics Data System (ADS)

Kurihara, Yosuke; Masuyama, Kosuke; Nakamura, Testuo; Bamba, Takeshi; Watanabe, Kajiro

Recently, there are various accidents and crimes related to the car. In some cases, the accidents and the crimes can be prevented if it is possible to detect a human who is in the car. For example, we can prevent a baby who is left in a car under the hot weather from dehydration or death occurred by heat inside disease. In another case, it is estimated that the United States currently has as many as 12 million illegal immigrants. In order to prevent further influx of illegal immigrants, the police are physically searching incoming vehicles at national boundaries aiming at finding those who are hiding inside. However, the physical inspections require much manpower cost and time. An inspection method to see inside the vehicles through X-ray images has also been used for this end. But the cost and the installation places are the problems of the large-scale X-ray system. Proposed in this paper is a piezoelectric ceramic system to handily measure the micro vibrations of motor vehicles. And applying the algorithm of Support Vector Machine (SVM), the existence of human body inside vehicles can be detected. The experiment was carried out using four types of vehicles: a mini car; an auto mobile; a van; and a truck weighing 1.5 tons. As the results, the correct determination ratio was 91.2% for the experiment with the piezoelectric ceramic under the front wheels and 97.0% under the rear wheels, when the vehicle used for the examination had also been used together with other three types of vehicles to obtain SVM training data. When the vehicle used for the examination had not been used together with the other three to obtain SVM training data, on the other hand, the correct determination ratio was 93.7% for the experiment with the piezoelectric ceramic under the front wheels and 95.7% under the rear wheels.

49 CFR 571.208a - Optional test procedures for vehicles manufactured between January 27, 2004 and August 31, 2004.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 20.6 °C and 22.2 °C (69 °F to 72 °F). S16.2.9 Steering wheel adjustment. S16.2.9.1 Adjust a tiltable steering wheel, if possible, so that the steering wheel hub is at the geometric center of its full range of driving positions. S16.2.9.2 If there is no setting detent at the mid-position, lower the steering wheel...

49 CFR 585.63 - Applicability.

Code of Federal Regulations, 2010 CFR

2010-10-01

... passenger cars, multipurpose passenger vehicles, trucks, and buses with a gross vehicle weight rating of 4,536 kilograms (10,000 pounds) or less, except those vehicles with dual wheels on an axle. However, this subpart does not apply to manufacturers whose production consists exclusively of vehicles...

48 CFR 552.211-88 - Vehicle export preparation.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 48 Federal Acquisition Regulations System 4 2012-10-01 2012-10-01 false Vehicle export preparation... Vehicle export preparation. As prescribed in 511.204(b)(8), insert the following clause: Vehicle Export Preparation (JAN 2010) Vehicles shall be prepared for export on wheels, unboxed, unless otherwise specified in...

48 CFR 552.211-88 - Vehicle export preparation.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 48 Federal Acquisition Regulations System 4 2014-10-01 2014-10-01 false Vehicle export preparation... Vehicle export preparation. As prescribed in 511.204(b)(8), insert the following clause: Vehicle Export Preparation (JAN 2010) Vehicles shall be prepared for export on wheels, unboxed, unless otherwise specified in...

48 CFR 552.211-88 - Vehicle export preparation.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Vehicle export preparation... Vehicle export preparation. As prescribed in 511.204(b)(8), insert the following clause: Vehicle Export Preparation (JAN 2010) Vehicles shall be prepared for export on wheels, unboxed, unless otherwise specified in...

Total dynamic response of a PSS vehicle negotiating asymmetric road excitations

NASA Astrophysics Data System (ADS)

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

2012-12-01

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

Track dynamic behavior at rail welds at high speed

NASA Astrophysics Data System (ADS)

Xiao, Guangwen; Xiao, Xinbiao; Guo, Jun; Wen, Zefeng; Jin, Xuesong

2010-06-01

As a vehicle passing through a track with different weld irregularities, the dynamic performance of track components is investigated in detail by using a coupled vehicle-track model. In the model, the vehicle is modeled as a multi-body system with 35 degrees of freedom, and a Timoshenko beam is used to model the rails which are discretely supported by sleepers. In the track model, the sleepers are modeled as rigid bodies accounting for their vertical, lateral and rolling motions and assumed to move backward at a constant speed to simulate the vehicle running along the track at the same speed. In the study of the coupled vehicle and track dynamics, the Hertizian contact theory and the theory proposed by Shen-Hedrick-Elkins are, respectively, used to calculate normal and creep forces between the wheel and the rails. In the calculation of the normal forces, the coefficient of the normal contact stiffness is determined by transient contact condition of the wheel and rail surface. In the calculation of the creepages, the lateral, roll-over motions of the rail and the fact that the relative velocity between the wheel and rail in their common normal direction is equal to zero are simultaneously taken into account. The motion equations of the vehicle and track are solved by means of an explicit integration method, in which the rail weld irregularities are modeled as local track vertical deviations described by some ideal cosine functions. The effects of the train speed, the axle load, the wavelength and depth of the irregularities, and the weld center position in a sleeper span on the wheel-rail impact loading are analyzed. The numerical results obtained are greatly useful in the tolerance design of welded rail profile irregularity caused by hand-grinding after rail welding and track maintenances.

Ancient road transport devices: Developments from the Bronze Age to the Roman Empire

NASA Astrophysics Data System (ADS)

Rossi, Cesare; Chondros, Thomas G.; Milidonis, Kypros F.; Savino, Sergio; Russo, Flavio

2016-03-01

The development of transportation systems has significantly enhanced the welfare and modernization of society. Wooden vehicles pulled by animals have been used for land transportation since the early Bronze Age. Whole-body gharries with rigid wheels pulled by oxen appeared in Crete by 2000 BC or earlier. Horses originating from the East were depicted in early Cretan seal-rings of the same period. The two-wheeled horsedrawn chariot was one of the most important inventions in history. This vehicle provided humanity its first concept of personal transport and was the key technology of war for 2000 years. Chariots of Mycenaean and Archaic Greece with light and flexible four-spoked wheels acting as spring suspensions were depicted in vase paintings. The development of this vehicle incorporated the seeds of a primitive design activity and was important for engineering. The Trojan horse since 1194 BC and the helepolis since 700 BC were the first known machines on a wheeled base transported by horses or self-powered. Ancient engineers invented bearings lubricated with fat, and Romans introduced the ancestors of ball bearings for their wagons and carts. The historic evolution of wheeled transportation systems, along with early traction, suspension, and braking systems, is presented in this paper. Analytical and numerical methods are incorporated to analyze the most conceivable loading situations of typically reconstructed wheeled transportation systems in ancient times. Traction requirements both for horse-driven machines and the power for internal motors are also analyzed. This study can serve as a basis for further development of detailed reconstruction of transportation systems in antiquity.

Development of a wear model for the wheel profile optimisation on railway vehicles

NASA Astrophysics Data System (ADS)

Ignesti, M.; Innocenti, A.; Marini, L.; Meli, E.; Rindi, A.

2013-09-01

The modelling and the reduction of wear due to wheel-rail interaction is a fundamental aspect in the railway field, mainly correlated to safety, maintenance interventions and costs. In this work, the authors present two innovative wheel profiles, specifically designed with the aim of improving the wear and stability behaviour of the standard ORE S1002 wheel profile matched with the UIC60 rail profile canted at 1/20 rad, which represents the wheel-rail combination adopted in the Italian railway line. The two wheel profiles, conventionally named CD1 and DR2, have been developed by the authors in collaboration with Trenitalia S.p.A. The CD1 profile has been designed with the purpose of spreading the contact points in the flange zone on a larger area in order to reduce wear phenomena and having a constant equivalent conicity for small lateral displacements of the wheelset with respect to the centred position in the track. The DR2 wheel profile is instead designed to guarantee the same kinematic characteristics of the matching formed by ORE S1002 wheel profile and UIC60 rail profile with laying angle α p equal to 1/40 rad, widely common in European railways and characterised by good performances in both wear and kinematic behaviour. The evolution of wheel profiles due to wear has been evaluated through a wear model developed and validated by the authors in previous works. The wear model comprises two mutually interactive units: a vehicle model for the dynamic simulations and a model for the wear assessment. The whole model is based on a discrete process: each discrete step consists in one dynamic simulation and one profile update by means of the wear model while, within the discrete step, the profiles are supposed to be constant. The choice of an appropriate step is crucial in terms of precision and computational effort: the particular strategy adopted in the current work has been chosen for its capacity in representing the nonlinear wear evolution and for the low computational time required. In the present research, the investigated trainset is the passenger vehicle ALSTOM ALn 501 'Minuetto', which is usually equipped with the standard ORE S1002 wheel profile in Italian railways. The entire model has been simulated on a virtual track specifically developed to represent a statistical description of the whole Italian line. The data necessary to build the virtual track and the vehicle model were provided by Trenitalia S.p.A. and Rete Ferroviaria Italiana. The CD1 and DR2 wheel profiles, matched to the UIC60 rail with cant 1/20 rad, have shown a good behaviour in terms of wear resistance if compared with the old ORE S1002 wheel profile, consequently assuring a more uniform distribution of the removed material and a prolongation of the mean time between two subsequent re-profiling interventions.

Torque blending and wheel slip control in EVs with in-wheel motors

NASA Astrophysics Data System (ADS)

de Castro, Ricardo; Araújo, Rui E.; Tanelli, Mara; Savaresi, Sergio M.; Freitas, Diamantino

2012-01-01

Among the many opportunities offered by electric vehicles (EVs), the design of power trains based on in-wheel electric motors represents, from the vehicle dynamics point of view, a very attractive prospect, mainly due to the torque-vectoring capabilities. However, this distributed propulsion also poses some practical challenges, owing to the constraints arising from motor installation in a confined space, to the increased unsprung mass weight and to the integration of the electric motor with the friction brakes. This last issue is the main theme of this work, which, in particular, focuses on the design of the anti-lock braking system (ABS). The proposed structure for the ABS is composed of a tyre slip controller, a wheel torque allocator and a braking supervisor. To address the slip regulation problem, an adaptive controller is devised, offering robustness to uncertainties in the tyre-road friction and featuring a gain-scheduling mechanism based on the vehicle velocity. Further, an optimisation framework is employed in the torque allocator to determine the optimal split between electric and friction brake torque based on energy performance metrics, actuator constraints and different actuators bandwidth. Finally, based on the EV working condition, the priorities of this allocation scheme are adapted by the braking supervisor unit. Simulation results obtained with the CarSim vehicle model, demonstrate the effectiveness of the overall approach.

Investigation of the effects of sleeper-passing impacts on the high-speed train

NASA Astrophysics Data System (ADS)

Wu, Xingwen; Cai, Wubin; Chi, Maoru; Wei, Lai; Shi, Huailong; Zhu, Minhao

2015-12-01

The sleeper-passing impact has always been considered negligible in normal conditions, while the experimental data obtained from a High-speed train in a cold weather expressed significant sleeper-passing impacts on the axle box, bogie frame and car body. Therefore, in this study, a vertical coupled vehicle/track dynamic model was developed to investigate the sleeper-passing impacts and its effects on the dynamic performance of the high-speed train. In the model, the dynamic model of vehicle is established with 10 degrees of freedom. The track model is formulated with two rails supported on the discrete supports through the finite element method. The contact forces between the wheel and rail are estimated using the non-linear Hertz contact theory. The parametric studies are conducted to analyse effects of both the vehicle speeds and the discrete support stiffness on the sleeper-passing impacts. The results show that the sleeper-passing impacts become extremely significant with the increased support stiffness of track, especially when the frequencies of sleeper-passing impacts approach to the resonance frequencies of wheel/track system. The damping of primary suspension can effectively lower the magnitude of impacts in the resonance speed ranges, but has little effect on other speed ranges. Finally, a more comprehensively coupled vehicle/track dynamic model integrating with a flexible wheel set is developed to discuss the sleeper-passing-induced flexible vibration of wheel set.

Design of a steering stabilizer based on CAN bus

NASA Astrophysics Data System (ADS)

Zhan, Zhaomin; Yan, Yibin

2018-04-01

This design realizes a posture correction device of griping steering wheel based on CAN bus, which is embedded in the steering wheel of vehicles. The system aims to detect the drivers' abnormal griping postures and provides drivers with classification alerts, by combining the recorded griping postures data and the vehicle speed data that are obtained via the CAN bus. The warning information are automatically stored and retained in the device for 12 months. To enhance the alerting effect, the count of this warning message for both the latest month and the last 12 months are displayed on the dashboard panel. In addition to prevent itself from being blocked and self-detect any faults in advance, the appliance also provide a self-test function, which will communicate with the integrated instrument system in vehicle and do simulation test right after the vehicle power on. This appliance can help to urge and ensure drivers to operate the steering wheel correctly, effectively, and timely; prevent some typical incorrect behaviors which commonly happen along with the change of griping postures, such as the using cellphone, and ultimately, reduce the incidence of traffic accidents.

Extended applications of track irregularity probabilistic model and vehicle-slab track coupled model on dynamics of railway systems

NASA Astrophysics Data System (ADS)

Xu, Lei; Zhai, Wanming; Gao, Jianmin

2017-11-01

Track irregularities are inevitably in a process of stochastic evolution due to the uncertainty and continuity of wheel-rail interactions. For depicting the dynamic behaviours of vehicle-track coupling system caused by track random irregularities thoroughly, it is a necessity to develop a track irregularity probabilistic model to simulate rail surface irregularities with ergodic properties on amplitudes, wavelengths and probabilities, and to build a three-dimensional vehicle-track coupled model by properly considering the wheel-rail nonlinear contact mechanisms. In the present study, the vehicle-track coupled model is programmed by combining finite element method with wheel-rail coupling model firstly. Then, in light of the capability of power spectral density (PSD) in characterising amplitudes and wavelengths of stationary random signals, a track irregularity probabilistic model is presented to reveal and simulate the whole characteristics of track irregularity PSD. Finally, extended applications from three aspects, that is, extreme analysis, reliability analysis and response relationships between dynamic indices, are conducted to the evaluation and application of the proposed models.

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

NASA Astrophysics Data System (ADS)

Shao, Xinxin; Naghdy, Fazel; Du, Haiping

2017-03-01

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

Design and optimisation of wheel-rail profiles for adhesion improvement

NASA Astrophysics Data System (ADS)

Liu, B.; Mei, T. X.; Bruni, S.

2016-03-01

This paper describes a study for the optimisation of the wheel profile in the wheel-rail system to increase the overall level of adhesion available at the contact interface, in particular to investigate how the wheel and rail profile combination may be designed to ensure the improved delivery of tractive/braking forces even in poor contact conditions. The research focuses on the geometric combination of both wheel and rail profiles to establish how the contact interface may be optimised to increase the adhesion level, but also to investigate how the change in the property of the contact mechanics at the wheel-rail interface may also lead to changes in the vehicle dynamic behaviour.

Multi-Sensor Based Online Attitude Estimation and Stability Measurement of Articulated Heavy Vehicles.

PubMed

Zhu, Qingyuan; Xiao, Chunsheng; Hu, Huosheng; Liu, Yuanhui; Wu, Jinjin

2018-01-13

Articulated wheel loaders used in the construction industry are heavy vehicles and have poor stability and a high rate of accidents because of the unpredictable changes of their body posture, mass and centroid position in complex operation environments. This paper presents a novel distributed multi-sensor system for real-time attitude estimation and stability measurement of articulated wheel loaders to improve their safety and stability. Four attitude and heading reference systems (AHRS) are constructed using micro-electro-mechanical system (MEMS) sensors, and installed on the front body, rear body, rear axis and boom of an articulated wheel loader to detect its attitude. A complementary filtering algorithm is deployed for sensor data fusion in the system so that steady state margin angle (SSMA) can be measured in real time and used as the judge index of rollover stability. Experiments are conducted on a prototype wheel loader, and results show that the proposed multi-sensor system is able to detect potential unstable states of an articulated wheel loader in real-time and with high accuracy.

Multi-Sensor Based Online Attitude Estimation and Stability Measurement of Articulated Heavy Vehicles

PubMed Central

Xiao, Chunsheng; Liu, Yuanhui; Wu, Jinjin

2018-01-01

Articulated wheel loaders used in the construction industry are heavy vehicles and have poor stability and a high rate of accidents because of the unpredictable changes of their body posture, mass and centroid position in complex operation environments. This paper presents a novel distributed multi-sensor system for real-time attitude estimation and stability measurement of articulated wheel loaders to improve their safety and stability. Four attitude and heading reference systems (AHRS) are constructed using micro-electro-mechanical system (MEMS) sensors, and installed on the front body, rear body, rear axis and boom of an articulated wheel loader to detect its attitude. A complementary filtering algorithm is deployed for sensor data fusion in the system so that steady state margin angle (SSMA) can be measured in real time and used as the judge index of rollover stability. Experiments are conducted on a prototype wheel loader, and results show that the proposed multi-sensor system is able to detect potential unstable states of an articulated wheel loader in real-time and with high accuracy. PMID:29342850

Alternative Fuels Data Center

Science.gov Websites

electric vehicle. An eligible vehicle must: Be a four-wheeled motor vehicle manufactured for use on public maximum speed of at least 55 mph, and Be propelled at least in part by an electric motor and associated

Apparatus for inspecting a group of containers and method of using same

DOEpatents

Lee, Jr., James H.; Salton, Jonathan R [Albuquerque, NM; Spletzer, Barry L [Albuquerque, NM

2012-02-28

An apparatus and method for inspecting a plurality of containers are provided. Each container has an outer surface for housing at least one material therein. The techniques provided involve at least one inspection vehicle and at least one detector. Each inspection vehicle has a plurality of wheels for movably positioning about the plurality of containers. The wheels may have at least one magnet for selectively adhering to the outer surface of at least one of the containers whereby the inspection vehicle traverses the container(s). The detector is positionable proximate at least one of the containers. The detector may be deployable from the inspection vehicle to a position adjacent the container(s). The detector has at least one sensor for measuring at least one characteristic of the plurality of containers. At least one base station may be provided for communicating with the inspection vehicle(s) and/or detector(s).

Extremity Fractures Associated With ATVs and Dirt Bikes: A 6 Year National Epidemiological Study

PubMed Central

Gambone, Andrew; Lombardo, Daniel Joseph; Jelsema, Timothy; Sabesan, Vani

2015-01-01

Objectives: All-terrain vehicle (ATV) and dirt bike use is increasing in the US and is associated with risk of traumatic injury. Extremity fractures are common injures associated with these vehicles. The purpose of this study is to compare and contrast the patterns extremity fractures associated with ATVs and dirt bikes. Our hypothesis is that these different vehicles will result in similar rates of high impact injuries, but differences in vehicle stability will result in greater proportions of upper extremity fractures associated with ATV use. Methods: The National Electronic Injury Surveillance System (NEISS) was used to acquire data for extremity fractures related to ATV (3-wheels, 4-wheels, and number of wheels undefined) and dirt bike use from 2007-2012. Locations were coded as shoulder, upper arm, elbow, lower arm, wrist, hand, upper leg, knee, lower leg, ankle, foot, and toe. The data were stratified according to age and gender for each year. Incidence rates were calculated on a per vehicle basis using previous estimates of the number of ATVs and dirt bikes in the country. Results: The database yielded an estimate of 229,362.52 extremity fractures from 2007-2012. An estimated total of 130,319.20 fractures were associated with ATVs, while 99,043.37 were associated with dirt bikes. The incidence rates of extremity fractures associated with ATV and dirt bike use were 3.87 and 6.85 per 1000 vehicle-years. Most fractures were in patients 10-19 years of age, after which the number of fractures decreased with age. The largest proportion of all fractures occurred in the shoulder (27.19%), followed by the wrist and lower leg (13.77% and 12.36%, respectively). This distribution of fractures was consistent among ATV use for all age groups except in the 0-9 year olds, where the lower arm and wrist were the most commonly fractured locations. Fracture distribution associated with dirt bike use also followed this general pattern, with the exception of 0-9 and 10-19 year olds having increased proportions of lower arm fractures. When comparing the genders, males had much larger proportions of fractures than females at all locations, except for the upper arm. When comparing the specific injury locations for different vehicle types, there were no differences in the distribution of the location of fractures among 4-wheeled or unspecified ATVs. However, 3-wheeled ATVs and dirt bikes had much larger proportion of lower leg, foot and ankle fractures compared to the other vehicle types. Conclusion: Extremity fractures are among the most common type of injury resulting from ATV and dirt bike use. Our results demonstrated a pattern of injury where the shoulder and lower arm were the most commonly injured locations. This pattern was inconsistent among females, the very young, and 3 wheeled ATVs and dirt bikes. These differences could be due to both rider related factors and vehicle design factors. Knowing commonly fractured locations, the use of additional protective equipment specific to these injuries may be beneficial. Additionally, participants should be cautioned of the increased risk of fractures associated with dirt bike use, as well as the unusual pattern of injuries of 3-wheeled ATVs implying instability of these vehicles.

Motion estimation by integrated low cost system (vision and MEMS) for positioning of a scooter "Vespa"

NASA Astrophysics Data System (ADS)

Guarnieri, A.; Milan, N.; Pirotti, F.; Vettore, A.

2011-12-01

In the automotive sector, especially in these last decade, a growing number of investigations have taken into account electronic systems to check and correct the behavior of drivers, increasing road safety. The possibility to identify with high accuracy the vehicle position in a mapping reference frame for driving directions and best-route analysis is also another topic which attracts lot of interest from the research and development sector. To reach the objective of accurate vehicle positioning and integrate response events, it is necessary to estimate time by time the position, orientation and velocity of the system. To this aim low cost GPS and MEMS (sensors can be used. In comparison to a four wheel vehicle, the dynamics of a two wheel vehicle (e.g. a scooter) feature a higher level of complexity. Indeed more degrees of freedom must be taken into account to describe the motion of the latter. For example a scooter can twist sideways, thus generating a roll angle. A slight pitch angle has to be considered as well, since wheel suspensions have a higher degree of motion with respect to four wheel vehicles. In this paper we present a method for the accurate reconstruction of the trajectory of a motorcycle ("Vespa" scooter), which can be used as alternative to the "classical" approach based on the integration of GPS and INS sensors. Position and orientation of the scooter are derived from MEMS data and images acquired by on-board digital camera. A Bayesian filter provides the means for integrating the data from MEMS-based orientation sensor and the GPS receiver.

Rail commuter vehicle curving performance

DOT National Transportation Integrated Search

2002-04-01

This report presents results of a program to design and install a wayside wheel-rail force measurement system. The test site is capable of developing a set of measurements of lateral and vertical forces exerted between the wheel and the rail at caref...

Analyses of rail chill effect

DOT National Transportation Integrated Search

1998-06-01

The principles of heat transfer are applied to analyze the so-called "rail chill" effect, which refers to hear loss by conduction from a hot rail vehicle wheel through the contact area into a cold rail, the wheel having been heated by friction brakin...

Region 5: Ohio Lima and Wheeling Adequate Letter (4/18/2007)

EPA Pesticide Factsheets

This letter from EPA to the Ohio Environmental Protection Agency determined the 2009 and 2018 motor vehicle emission budgets (MVEBs) for volatile organic compounds (VOCs) and oxides of nitrogen (NOx) for the Allen County (Lima), Belmont County (Wheeling),

A Two-Wheeled, Self-Balancing Electric Vehicle Used As an Environmentally Friendly Individual Means of Transport

NASA Astrophysics Data System (ADS)

Bździuch, D.; Grzegożek, W.

2016-09-01

This paper shows a concept of a model of a two-wheeled self-balancing vehicle with an electric motor drive as an environmentally-friendly personal transporter. The principle of work, modelling of construction and performing a simulation are presented and discussed. The visualization of the designed vehicle was made thanks to using Solid Works a computer-aided design program. The vehicle was modelled as an inverted pendulum. The stability of the mechanism in the equilibrium position was studied. An exemplary steering system was also subjected to the analysis that compared two controllers: PID and LQR which enabled to monitor the balance of the vehicle when the required conditions were fulfilled. Modelling of work of the controllers and the evaluation of the obtained results in required conditions were performed in the MATLAB environment.

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, KSC employee Gene Peavler works in the wheel area on the orbiter Discovery. The vehicle has undergone Orbiter Major Modifications in the past year. Discovery is scheduled to fly on mission STS-121 to the International Space Station.

NASA Image and Video Library

2003-12-09

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, KSC employee Gene Peavler works in the wheel area on the orbiter Discovery. The vehicle has undergone Orbiter Major Modifications in the past year. Discovery is scheduled to fly on mission STS-121 to the International Space Station.

Factors that influence tractive performance of wheels, tracks, and vehicles

USDA-ARS?s Scientific Manuscript database

Traction of agricultural vehicles and other off-road vehicles is important in allowing these vehicles to perform their desired tasks. This book chapter describes factors affecting the off-road tractive performance of tires and rubber tracks. Tractive performance is affected by soil type, soil cond...

Emissions from U.S. waste collection vehicles.

PubMed

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

2013-05-01

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

Department of the Navy Supporting Data for Fiscal Year 1984 Budget Estimates Descriptive Summaries Submitted to Congress January 1983. Research, Development, Test and Evaluation, Navy. Book 2. Tactical Programs

DTIC Science & Technology

1983-01-01

SUMMARY: (ollars in Thouesands) The changes between the funding profile shown in the FY 1983 Descriptive Summary and that shown in this De ,,criptive...System (ONAV Report Symbol 3960-12 b. I April 1982 MOSC Test Report Joint Tactical Information Distribution System Phase II (Distributed Time De -ision...Vehicle Tricked (LVTP7) 453 - - - 5,728 Product Improvement C0021 Landing Vehicle Tracked-Al - - - 2,848*, TBD TED C0061 Battlefield Surveillance De -vices

40 CFR 205.51 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... with combat or tactical vehicles. (13) Exhaust System means the system comprised of a combination of...) Gross Combination Weight Rating (GCWR) means the value specified by the manufacturer as the loaded weight of a combination vehicle. (15) Gross Vehicle Weight Rating (GVWR) means the value specified by the...

40 CFR 205.51 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... with combat or tactical vehicles. (13) Exhaust System means the system comprised of a combination of...) Gross Combination Weight Rating (GCWR) means the value specified by the manufacturer as the loaded weight of a combination vehicle. (15) Gross Vehicle Weight Rating (GVWR) means the value specified by the...

40 CFR 205.51 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... with combat or tactical vehicles. (13) Exhaust System means the system comprised of a combination of...) Gross Combination Weight Rating (GCWR) means the value specified by the manufacturer as the loaded weight of a combination vehicle. (15) Gross Vehicle Weight Rating (GVWR) means the value specified by the...

40 CFR 205.51 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... with combat or tactical vehicles. (13) Exhaust System means the system comprised of a combination of...) Gross Combination Weight Rating (GCWR) means the value specified by the manufacturer as the loaded weight of a combination vehicle. (15) Gross Vehicle Weight Rating (GVWR) means the value specified by the...

Proceedings - International Conference on Wheel/Rail Load and Displacement Measurement Techniques : January 19-20, 1981

DOT National Transportation Integrated Search

1981-09-01

Measurement of wheel/rail characteristics generates information for improvement of design tools such as model validation, establishment of load spectra and vehicle/track system interaction. Existing and new designs are assessed from evaluation of veh...

A new formulation of the understeer coefficient to relate yaw torque and vehicle handling

NASA Astrophysics Data System (ADS)

Bucchi, F.; Frendo, F.

2016-06-01

The handling behaviour of vehicles is an important property for its relation to performance and safety. In 1970s, Pacejka did the groundwork for an objective analysis introducing the handling diagram and the understeer coefficient. In more recent years, the understeer concept is still mentioned but the handling is actively managed by direct yaw control (DYC). In this paper an accurate analysis of the vehicle handling is carried out, considering also the effect of drive forces. This analysis brings to a new formulation of the understeer coefficient, which is almost equivalent to the classical one, but it can be obtained by quasi-steady-state manoeuvres. In addition, it relates the vehicle yaw torque to the understeer coefficient, filling up the gap between the classical handling approach and DYC. A multibody model of a Formula SAE car is then used to perform quasi-steady-state simulations in order to verify the effectiveness of the new formulation. Some vehicle set-ups and wheel drive arrangements are simulated and the results are discussed. In particular, the handling behaviours of the rear wheel drive (RWD) and the front wheel drive (FWD) architectures are compared, finding an apparently surprising result: for the analysed vehicle the FWD is less understeering than for RWD. The relation between the yaw torque and the understeer coefficient allows to understand this behaviour and opens-up the possibility for different yaw control strategies.

On Navigation Sensor Error Correction

NASA Astrophysics Data System (ADS)

Larin, V. B.

2016-01-01

The navigation problem for the simplest wheeled robotic vehicle is solved by just measuring kinematical parameters, doing without accelerometers and angular-rate sensors. It is supposed that the steerable-wheel angle sensor has a bias that must be corrected. The navigation parameters are corrected using the GPS. The approach proposed regards the wheeled robot as a system with nonholonomic constraints. The performance of such a navigation system is demonstrated by way of an example

Performance of the Boeing LRV wheels in a lunar soil simulant. Report 2: Effects of speed, Wheel load, and soil

NASA Technical Reports Server (NTRS)

Melzer, K.

1971-01-01

Two nearly identical Boeing-GM wire-mesh Lunar Roving Vehicle (LRV) wheels were laboratory tested in a lunar soil simulant to determine the influence of wheel speed and acceleration, wheel load, presence of a fender, travel direction, and soil strength on the wheel performance. Constant-slip and three types of programmed-slip tests were conducted with a single-wheel dynamometer system. Test results indicated that performance of single LRV wheels in terms of pull coefficient, power number, and efficiency were not influenced by wheel speed and acceleration, travel direction, the presence of a fender, or wheel load. Of these variables, only load influenced sinkage, which increased with increasing load. For a given slip, the pull coefficient and power number increased with increasing soil strength. However, for a given pull coefficient or slope, slip was less in firmer soil; thus, the power number decreased and efficiency increased with increasing soil strength.

41 CFR 101-45.004 - All terrain vehicles.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 41 Public Contracts and Property Management 2 2012-07-01 2012-07-01 false All terrain vehicles. 101-45.004 Section 101-45.004 Public Contracts and Property Management Federal Property Management... DESTRUCTION OF PERSONAL PROPERTY § 101-45.004 All terrain vehicles. (a) Three-wheeled all terrain vehicles...

Effect of Weight Transfer on a Vehicle's Stopping Distance.

ERIC Educational Resources Information Center

Whitmire, Daniel P.; Alleman, Timothy J.

1979-01-01

An analysis of the minimum stopping distance problem is presented taking into account the effect of weight transfer on nonskidding vehicles and front- or rear-wheels-skidding vehicles. Expressions for the minimum stopping distances are given in terms of vehicle geometry and the coefficients of friction. (Author/BB)

49 CFR 585.61 - Scope.

Code of Federal Regulations, 2010 CFR

2010-10-01

... passenger cars, multipurpose passenger vehicles, trucks, and buses with a gross vehicle weight rating of 4,536 kilograms (10,000 pounds) or less, except those vehicles with dual wheels on an axle, to submit a report, and maintain records related to the report, concerning the number of such vehicles that meet the...

Providing drivers with road-edge information to reduce road departure crashes in a military vehicle fleet.

DOT National Transportation Integrated Search

2008-02-26

A leading cause of military vehicle rollover crashes is that one or more wheels move into an area where : the terrain falls away steeply or disappears, leading to vehicle rollover. Vehicle-mounted sensors will : soon be capable of sensing such hazard...

The Pneumatic Actuators As Vertical Dynamic Load Simulators On Medium Weighted Wheel Suspension Mechanism

NASA Astrophysics Data System (ADS)

Ka'ka, Simon; Himran, Syukri; Renreng, Ilyas; Sutresman, Onny

2018-02-01

Almost all of road damage can be caused by dynamic loads of vehicles that fluctuate according to the type of vehicle that passes through. This study aims to calculate the vertical dynamic load of the vehicle actually occurs on road construction by the mechanism of vehicle wheel suspension. Pneumatic cylinders driven by pressurized air directly load the spring and shock absorber installed on the wheels of the vehicle. The load fluctuations of the medium weight categorized vehicles are determined by the regulation of the amount of pressurized air that enters into the pneumatic cylinder chamber, pushing the piston and connecting rods. The displacement that occurs during compression on the spring and shock absorber, is substituted into the equation of vehicle dynamic load while taking into account the spring stiffness constant, and the fluid or damper gas coefficient. The results show that the magnitude of the displacement when the compression force works has significant influences to the amount of vertical dynamic load of the vehicle that overlies the road construction. The presence of dynamic load of vehicles that fluctuates and repeats, also affects on the reduction of road ability to receive the load. Experimental results using pneumatic actuators instead of real dynamic vehicle loads illustrate the characteristics of the relationship between work pressure and dynamic load. If the working pressure of P2 (bar) is greater, the vertical dynamic load Ft (N) that overloads the road structure is also greater. The associate graphs show that the shock absorber has a greater ability to reduce dynamic load vertically that burden the road structure when compared with the ability of screw spring.

An application to model traffic intensity of agricultural machinery at field scale

NASA Astrophysics Data System (ADS)

Augustin, Katja; Kuhwald, Michael; Duttmann, Rainer

2017-04-01

Several soil-pressure-models deal with the impact of agricultural machines on soils. In many cases, these models were used for single spots and consider a static machine configuration. Therefore, a statement about the spatial distribution of soil compaction risk for entire working processes is limited. The aim of the study is the development of an application for the spatial modelling of traffic lanes from agricultural vehicles including wheel load, ground pressure and wheel passages at the field scale. The application is based on Open Source software, application and data formats, using python programming language. Minimum input parameters are GPS-positions, vehicles and tires (producer and model) and the tire inflation pressure. Five working processes were distinguished: soil tillage, manuring, plant protection, sowing and harvest. Currently, two different models (Diserens 2009, Rücknagel et al. 2015) were implemented to calculate the soil pressure. The application was tested at a study site in Lower Saxony, Germany. Since 2015, field traffic were recorded by RTK-GPS and used machine set ups were noted. Using these input information the traffic lanes, wheel load and soil pressure were calculated for all working processes. For instance, the maize harvest in 2016 with a crop chopper and one transport vehicle crossed about 55 % of the total field area. At some places the machines rolled over up to 46 times. Approximately 35 % of the total area was affected by wheel loads over 7 tons and soil pressures between 163 and 193 kPa. With the information about the spatial distribution of wheel passages, wheel load and soil pressure it is possible to identify hot spots of intensive field traffic. Additionally, the use of the application enables the analysis of soil compaction risk induced by agricultural machines for long- and short-term periods.

Self-reported difficulty and preferences of wheeled mobility device users for simulated low-floor bus boarding, interior circulation and disembarking.

PubMed

D'Souza, Clive; Paquet, Victor L; Lenker, James A; Steinfeld, Edward

2017-11-13

Low ridership of public transit buses among wheeled mobility device users suggests the need to identify vehicle design conditions that are either particularly accommodating or challenging. The objective of this study was to determine the effects of low-floor bus interior seating configuration and passenger load on wheeled mobility device user-reported difficulty, overall acceptability and design preference. Forty-eight wheeled mobility users evaluated three interior design layouts at two levels of passenger load (high vs. low) after simulating boarding and disembarking tasks on a static full-scale low-floor bus mockup. User self-reports of task difficulty, acceptability and design preference were analyzed across the different test conditions. Ramp ascent was the most difficult task for manual wheelchair users relative to other tasks. The most difficult tasks for users of power wheelchairs and scooters were related to interior circulation, including moving to the securement area, entry and positioning in the securement area and exiting the securement area. Boarding and disembarking at the rear doorway was significantly more acceptable and preferred compared to the layouts with front doorways. Understanding transit usability barriers, perceptions and preferences among wheeled mobility users is an important consideration for clinicians who recommend mobility-related device interventions to those who use public transportation. Implications for Rehabilitation In order to maximize community participation opportunities for wheeled mobility users, clinicians should consider potential public transit barriers during the processes of wheelchair device selection and skills training. Usability barriers experienced by wheeled mobility device users on transit vehicles differ by mobility device type and vehicle configurations. Full-scale environment simulations are an effective means of identifying usability barriers and design needs in people with mobility impairments and may provide an alternative model for determining readiness for using fixed route buses or eligibility for paratransit.

76 FR 55643 - Helena National Forest; Montana; Divide Travel Plan EIS

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-08

... DEPARTMENT OF AGRICULTURE Forest Service Helena National Forest; Montana; Divide Travel Plan EIS... Divide travel planning area for wheeled and over-snow motorized vehicles. Consistent with Forest Service travel planning regulations, the designated wheeled motorized routes within the Divide Travel Planning...

The Benefit Impact of Air Pollution Reduction Through ATCS Implementation at Intersections

NASA Astrophysics Data System (ADS)

Budihardjo, Mochamad Arief; Huboyo, Haryono Setiyo; Samadikun, Budi Prasetyo

2018-02-01

The field study in five intersections that had ATCS, such as Krapyak, Tugu Muda, Polda, Bangkong and Fatmawati were done to investigate the effectivity of air pollution reduction. The study was done by estimating the differences between the vehicle speed due to the cycle duration of green light by field observation and video recording in each intersection. In five intersections that had been observed, the percentage of fuel consumption savings for two-wheeled vehicles were between 15 - 18%, meanwhile for four-wheel vehicles were between 30 - 46%. Based on the calculation that adopt the emission factor from CORINAIR and USEPA emission, the emission reduction based on pollutant types were TSP (12-17%), NOx (22-36%), CO (15-25%), HC (16-28%) and SO2 (22-35%). The result to the vehicles' speed that passed the intersections through ATCS has also indicated that the ATCS could increase vehicle speed and consequently reduce the emission.

Research on motor braking-based DYC strategy for distributed electric vehicle

NASA Astrophysics Data System (ADS)

Zhang, Jingming; Liao, Weijie; Chen, Lei; Cui, Shumei

2017-08-01

In order to bring into full play the advantages of motor braking and enhance the handling stability of distributed electric vehicle, a motor braking-based direct yaw moment control (DYC) strategy was proposed. This strategy could identify whether a vehicle has under-steered or overs-steered, to calculate the direct yaw moment required for vehicle steering correction by taking the corrected yaw velocity deviation and slip-angle deviation as control variables, and exert motor braking moment on the target wheels to perform correction in the manner of differential braking. For validation of the results, a combined simulation platform was set up finally to simulate the motor braking control strategy proposed. As shown by the results, the motor braking-based DYC strategy timely adjusted the motor braking moment and hydraulic braking moment on the target wheels, and corrected the steering deviation and sideslip of the vehicle in unstable state, improving the handling stability.

New methodology for fast prediction of wheel wear evolution

NASA Astrophysics Data System (ADS)

Apezetxea, I. S.; Perez, X.; Casanueva, C.; Alonso, A.

2017-07-01

In railway applications wear prediction in the wheel-rail interface is a fundamental matter in order to study problems such as wheel lifespan and the evolution of vehicle dynamic characteristic with time. However, one of the principal drawbacks of the existing methodologies for calculating the wear evolution is the computational cost. This paper proposes a new wear prediction methodology with a reduced computational cost. This methodology is based on two main steps: the first one is the substitution of the calculations over the whole network by the calculation of the contact conditions in certain characteristic point from whose result the wheel wear evolution can be inferred. The second one is the substitution of the dynamic calculation (time integration calculations) by the quasi-static calculation (the solution of the quasi-static situation of a vehicle at a certain point which is the same that neglecting the acceleration terms in the dynamic equations). These simplifications allow a significant reduction of computational cost to be obtained while maintaining an acceptable level of accuracy (error order of 5-10%). Several case studies are analysed along the paper with the objective of assessing the proposed methodology. The results obtained in the case studies allow concluding that the proposed methodology is valid for an arbitrary vehicle running through an arbitrary track layout.

Integrated Fault Diagnosis Algorithm for Motor Sensors of In-Wheel Independent Drive Electric Vehicles.

PubMed

Jeon, Namju; Lee, Hyeongcheol

2016-12-12

An integrated fault-diagnosis algorithm for a motor sensor of in-wheel independent drive electric vehicles is presented. This paper proposes a method that integrates the high- and low-level fault diagnoses to improve the robustness and performance of the system. For the high-level fault diagnosis of vehicle dynamics, a planar two-track non-linear model is first selected, and the longitudinal and lateral forces are calculated. To ensure redundancy of the system, correlation between the sensor and residual in the vehicle dynamics is analyzed to detect and separate the fault of the drive motor system of each wheel. To diagnose the motor system for low-level faults, the state equation of an interior permanent magnet synchronous motor is developed, and a parity equation is used to diagnose the fault of the electric current and position sensors. The validity of the high-level fault-diagnosis algorithm is verified using Carsim and Matlab/Simulink co-simulation. The low-level fault diagnosis is verified through Matlab/Simulink simulation and experiments. Finally, according to the residuals of the high- and low-level fault diagnoses, fault-detection flags are defined. On the basis of this information, an integrated fault-diagnosis strategy is proposed.

Morphologic and chemical composition of particulate matter in motorcycle engine exhaust.

PubMed

Chernyshev, V V; Zakharenko, A M; Ugay, S M; Hien, T T; Hai, L H; Kholodov, A S; Burykina, T I; Stratidakis, A K; Mezhuev, Ya O; Tsatsakis, A M; Golokhvast, K S

2018-01-01

Despite the fact that environmental pollution due to motorcycle exhaust gases reports a great increase, motorcycle production exhibits a great increase through the last years. Countries of Asia and Africa are reported to be the major regions where two-wheeled vehicles are a major transportation mode, with tens of millions of units sold per year. Motorcycle exhaust particles are considered to be the major contributor to environmental pollution due to their airborne dispersion, containing great amount of polycyclic aromatic hydrocarbons (PAHs). This study aims at reporting an objective analysis of the main sources of the ambient air pollution as also particle size distribution and chemical composition analysis of particulate matter originated from the exhausts of two-wheeled vehicles used in the territory of Vladivostok, Russia. Various types of two-wheeled vehicles were examined (motorcycles, ATVs, scooters and wet bikes) using different types of engine and fuel system. Experimental results showed that there was no clear relation to the particle size distribution with the engine displacement of motorcycle and the number of strokes and the fuel system. Instead, there were reported two clear assumptions. The first one is that regarding to the motorcycle brand, a few samples did not exhibit a great percentage of PM 10 fraction. The second one is that more modern vehicles, that have a harmful gas afterburning system, are usually the source of an increased percentage of PM 10 emitted particles. At last, it should be mentioned that the laser particle size analysis method is capable of determining the particle sizes after their agglomeration whereas the optical morphometry method allows to determine the real particle size of emissions. In conclusion, it can be pointed out that the agglomeration of particles can lead to the reduction in the toxicity of particles emissions originated from two wheeled-vehicles.

Steering Performance, Tactical Vehicles

DTIC Science & Technology

2015-07-29

5 4.1 General Vehicle and Test Characterization ........................... 5 4.2 Weave Test...able to be driven in a straight line without steer input (i.e., “ hands free”). If the vehicle pulls in either direction, the alignment should be...Evaluation Center (AEC) prior to using military personnel as test participants. 4. TEST PROCEDURES. 4.1 General Vehicle and Test

Large Diameter Shuttle Launched-AEM (LDSL-AEM) study

NASA Technical Reports Server (NTRS)

1976-01-01

A technical description of a Large Diameter Shuttle Launched-AEM (LDSL-AEM), an AEM base module adapted to carry 5 ft diameter payloads in the shuttle with propulsion for carrying payloads to higher altitude orbits from a 150 NM shuttle orbit, is described. The AEM is designed for launch on the scout launch vehicle. Onboard equipment provides capability to despin, acquire the earth, and control the vehicle in an earth pointing mode using reaction wheels for torque with magnets for all attitude acquisition, wheel desaturation, and nutation damping. Earth sensors in the wheels provide pitch and roll attitude. This system provides autonomous control capability to 1 degree in pitch and roll and 2 degrees in yaw. The attitude can be determined to .5 degrees in pitch and roll and 2 degrees in yaw.

Sensor deployment on unmanned ground vehicles

NASA Astrophysics Data System (ADS)

Gerhart, Grant R.; Witus, Gary

2007-10-01

TARDEC has been developing payloads for small robots as part of its unmanned ground vehicle (UGV) development programs. These platforms typically weigh less than 100 lbs and are used for various physical security and force protection applications. This paper will address a number of technical issues including platform mobility, payload positioning, sensor configuration and operational tradeoffs. TARDEC has developed a number of robots with different mobility mechanisms including track, wheel and hybrid track/wheel running gear configurations. An extensive discussion will focus upon omni-directional vehicle (ODV) platforms with enhanced intrinsic mobility for positioning sensor payloads. This paper also discusses tradeoffs between intrinsic platform mobility and articulated arm complexity for end point positioning of modular sensor packages.

The influence of personal protection equipment, occupant body size, and restraint system on the frontal impact responses of Hybrid III ATDs in tactical vehicles.

PubMed

Zaseck, Lauren Wood; Orton, Nichole Ritchie; Gruber, Rebekah; Rupp, Jonathan; Scherer, Risa; Reed, Matthew; Hu, Jingwen

2017-08-18

Although advanced restraint systems, such as seat belt pretensioners and load limiters, can provide improved occupant protection in crashes, such technologies are currently not utilized in military vehicles. The design and use of military vehicles presents unique challenges to occupant safety-including differences in compartment geometry and occupant clothing and gear-that make direct application of optimal civilian restraint systems to military vehicles inappropriate. For military vehicle environments, finite element (FE) modeling can be used to assess various configurations of restraint systems and determine the optimal configuration that minimizes injury risk to the occupant. The models must, however, be validated against physical tests before implementation. The objective of this study was therefore to provide the data necessary for FE model validation by conducting sled tests using anthropomorphic test devices (ATDs). A secondary objective of this test series was to examine the influence of occupant body size (5th percentile female, 50th percentile male, and 95th percentile male), military gear (helmet/vest/tactical assault panels), seat belt type (3-point and 5-point), and advanced seat belt technologies (pretensioner and load limiter) on occupant kinematics and injury risk in frontal crashes. In total, 20 frontal sled tests were conducted using a custom sled buck that was reconfigurable to represent both the driver and passenger compartments of a light tactical military vehicle. Tests were performed at a delta-V of 30 mph and a peak acceleration of 25 g. The sled tests used the Hybrid III 5th percentile female, 50th percentile male, and 95th percentile male ATDs outfitted with standard combat boots and advanced combat helmets. In some tests, the ATDs were outfitted with additional military gear, which included an improved outer tactical vest (IOTV), IOTV and squad automatic weapon (SAW) gunner with a tactical assault panel (TAP), or IOTV and rifleman with TAP. ATD kinematics and injury outcomes were determined for each test. Maximum excursions were generally greater in the 95th percentile male compared to the 50th percentile male ATD and in ATDs wearing TAP compared to ATDs without TAP. Pretensioners and load limiters were effective in decreasing excursions and injury measures, even when the ATD was outfitted in military gear. ATD injury response and kinematics are influenced by the size of the ATD, military gear, and restraint system. This study has provided important data for validating FE models of military occupants, which can be used for design optimization of military vehicle restraint systems.

The physics of wheel-rail stability

NASA Astrophysics Data System (ADS)

Tan, B. T. G.

2018-05-01

This article discusses, at a simple level, the dynamics of the wheel-rail interface, which is fundamental to the stability of rail vehicles. The physics underlying this topic deserves to be better known by physicists and physics students, as it underpins such an important part of our technological infrastructure.

The Physics of Wheel-Rail Stability

ERIC Educational Resources Information Center

Tan, B. T. G.

2018-01-01

This article discusses, at a simple level, the dynamics of the wheel-rail interface, which is fundamental to the stability of rail vehicles. The physics underlying this topic deserves to be better known by physicists and physics students, as it underpins such an important part of our technological infrastructure

The Joint Tactical Aerial Resupply Vehicle Impact on Sustainment Operations

DTIC Science & Technology

2017-06-09

Artificial Intelligence , Sustainment Operations, Rifle Company, Autonomous Aerial Resupply, Joint Tactical Autonomous Aerial Resupply System 16...Integrations and Development System AI Artificial Intelligence ARCIC Army Capabilities Integration Center ARDEC Armament Research, Development and...semi- autonomous systems, and fully autonomous systems. Autonomy of machines depends on sophisticated software, including Artificial Intelligence

Dust control for Enabler

NASA Technical Reports Server (NTRS)

Hilton, Kevin; Karl, Chad; Litherland, Mark; Ritchie, David; Sun, Nancy

1992-01-01

The dust control group designed a system to restrict dust that is disturbed by the Enabler during its operation from interfering with astronaut or camera visibility. This design also considers the many different wheel positions made possible through the use of artinuation joints that provide the steering and wheel pitching for the Enabler. The system uses a combination of brushes and fenders to restrict the dust when the vehicle is moving in either direction and in a turn. This design also allows for each of maintenance as well as accessibility of the remainder of the vehicle.

Dust control for Enabler

NASA Technical Reports Server (NTRS)

Hilton, Kevin; Karl, Chad; Litherland, Mark; Ritchie, David; Sun, Nancy

1992-01-01

The dust control group designed a system to restrict dust that is disturbed by the Enabler during its operation from interfering with astronaut or camera visibility. This design also considers the many different wheel positions made possible through the use of artinuation joints that provide the steering and wheel pitching for the Enabler. The system uses a combination of brushes and fenders to restrict the dust when the vehicle is moving in either direction and in a turn. This design also allows for ease of maintenance as well as accessibility of the remainder of the vehicle.

Naturalistic Driving Study Investigating Self-Regulation Behavior in Early Alzheimer's Disease: A Pilot Study.

PubMed

Paire-Ficout, Laurence; Lafont, Sylviane; Conte, Fanny; Coquillat, Amandine; Fabrigoule, Colette; Ankri, Joël; Blanc, Frédéric; Gabel, Cécilia; Novella, Jean-Luc; Morrone, Isabella; Mahmoudi, Rachid

2018-05-16

Because cognitive processes decline in the earliest stages of Alzheimer's disease (AD), the driving abilities are often affected. The naturalistic driving approach is relevant to study the driving habits and behaviors in normal or critical situations in a familiar environment of participants. This pilot study analyzed in-car video recordings of naturalistic driving in patients with early-stage AD and in healthy controls, with a special focus on tactical self-regulation behavior. Twenty patients with early-stage AD (Diagnosis and Statistical Manual of Mental Disorders, Fourth Edition [DSM-IV] criteria), and 21 healthy older adults were included in the study. Data collection equipment was installed in their personal vehicles. Two expert psychologists assessed driving performance using a specially designed Naturalistic Driving Assessment Scale (NaDAS), paying particular attention to tactical self-regulation behavior, and they recorded all critical safety events. Poorer driving performance was observed among AD drivers: their tactical self-regulation behavior was of lower quality. AD patients had also twice as many critical events as healthy drivers and three times more "unaware" critical events. This pilot study using a naturalistic approach to accurately show that AD drivers have poorer tactical self-regulation behavior than healthy older drivers. Future deployment of assistance systems in vehicles should specifically target tactical self-regulation components.

Evaluating Environmental Impacts of Off-Road Vehicles.

ERIC Educational Resources Information Center

Kay, Jeanne; And Others

1981-01-01

Discusses a study undertaken to determine the ecological effects of off-road vehicles, such as four-wheel drive trucks and dirt bikes in the Big Cottonwood Canyon area near Salt Lake City. Applications of the study to other investigations of off-road vehicles are discussed. (DB)

A precise integration method for solving coupled vehicle-track dynamics with nonlinear wheel-rail contact

NASA Astrophysics Data System (ADS)

Zhang, J.; Gao, Q.; Tan, S. J.; Zhong, W. X.

2012-10-01

A new method is proposed as a solution for the large-scale coupled vehicle-track dynamic model with nonlinear wheel-rail contact. The vehicle is simplified as a multi-rigid-body model, and the track is treated as a three-layer beam model. In the track model, the rail is assumed to be an Euler-Bernoulli beam supported by discrete sleepers. The vehicle model and the track model are coupled using Hertzian nonlinear contact theory, and the contact forces of the vehicle subsystem and the track subsystem are approximated by the Lagrange interpolation polynomial. The response of the large-scale coupled vehicle-track model is calculated using the precise integration method. A more efficient algorithm based on the periodic property of the track is applied to calculate the exponential matrix and certain matrices related to the solution of the track subsystem. Numerical examples demonstrate the computational accuracy and efficiency of the proposed method.

Lightweight design and analysis of automobile wheel based on bending and radial loads

NASA Astrophysics Data System (ADS)

Jiang, X.; Lyu, R.; Fukushima, Y.; Otake, M.; Ju, D. Y.

2018-06-01

Lightweighting of automobile vehicle is a significant application trends, using magnesium alloy wheels is a valuable way. This article discusses design of a new model of automobile wheel. Then bending test and radial test finite element model were established. Considering three different materials namely magnesium alloy, aluminium alloy and steel, the stress and strain performances of each material can be obtained. Through evaluating and analyzing model in bending test and radial test, we obtained the reasonable and superior results for magnesium alloy wheel. The results of the equivalent stress and deformation were compared, the magnesium alloy wheel practicality has been confirmed. This research predicts the reliability of the structural design, some valuable references are provided for the design and development of magnesium alloy wheel.

Experimental Validation of a Differential Variational Inequality-Based Approach for Handling Friction and Contact in Vehicle

DTIC Science & Technology

2015-11-20

drawbar pull , wheel torque, and sinkage were measured for a lug-less rigid wheel for several slip cases and loading scenarios. The wheel used in this...0.6, µ =0.5, h =1× 10−3 seconds, τ =5×10−2 N. The quantitative results of this study are summarized in Figs. 11 through 13 for the drawbar pull , torque...and sinkage, respectively. It can be seen that as the slip of the wheel increases, the drawbar pull , torque, and sinkage also increase and the

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

NASA Technical Reports Server (NTRS)

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

2016-01-01

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

Use and user patterns among Michigan licensed off-highway vehicles ownership types

Treesearch

Joel A. Lynch; Charles M. Nelson

2002-01-01

Conventional off-highway vehicles (OHVs) range from small personal vehicles, such as motorcycles and all terrain vehicles to full-size passenger vehicles such as four-wheel drive trucks. The market and general recreational use of OHVs has changed markedly over the past thirty years. While many studies of OHV enthusiasts generalize to all OHV types, little research has...

Efficiencies from Applying a Rotational Equipping Strategy

DTIC Science & Technology

2011-01-01

Washington, D.C.: United States Government Accountability Office, 2007. NOTES: BFV = Bradley Fighting Vehicle, HEMTT = heavy expanded mobility tactical...of Its Equipment Reset Strategy, Washington, D.C.: United States Government Accountability Office, 2007. NOTES: BFV = Bradley Fighting Vehicle

Hitching a ride: Seed accrual rates on different types of vehicles.

PubMed

Rew, Lisa J; Brummer, Tyler J; Pollnac, Fredric W; Larson, Christian D; Taylor, Kimberley T; Taper, Mark L; Fleming, Joseph D; Balbach, Harold E

2018-01-15

Human activities, from resource extraction to recreation, are increasing global connectivity, especially to less-disturbed and previously inaccessible places. Such activities necessitate road networks and vehicles. Vehicles can transport reproductive plant propagules long distances, thereby increasing the risk of invasive plant species transport and dispersal. Subsequent invasions by less desirable species have significant implications for the future of threatened species and habitats. The goal of this study was to understand vehicle seed accrual by different vehicle types and under different driving conditions, and to evaluate different mitigation strategies. Using studies and experiments at four sites in the western USA we addressed three questions: How many seeds and species accumulate and are transported on vehicles? Does this differ with vehicle type, driving surface, surface conditions, and season? What is our ability to mitigate seed dispersal risk by cleaning vehicles? Our results demonstrated that vehicles accrue plant propagules, and driving surface, surface conditions, and season affect the rate of accrual: on- and off-trail summer seed accrual on all-terrain vehicles was 13 and 3508 seeds km -1 , respectively, and was higher in the fall than in the summer. Early season seed accrual on 4-wheel drive vehicles averaged 7 and 36 seeds km -1 on paved and unpaved roads respectively, under dry conditions. Furthermore, seed accrual on unpaved roads differed by vehicle type, with tracked vehicles accruing more than small and large 4-wheel drives; and small 4-wheel drives more than large. Rates were dramatically increased under wet surface conditions. Vehicles indiscriminately accrue a wide diversity of seeds (different life histories, forms and seed lengths); total richness, richness of annuals, biennials, forbs and shrubs, and seed length didn't differ among vehicle types, or additional seed bank samples. Our evaluation of portable vehicle wash units showed that approximately 80% of soil and seed was removed from dirty vehicles. This suggests that interception programs to reduce vehicular seed transportation risk are feasible and should be developed for areas of high conservation value, or where the spread of invasive species is of special concern. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

32 CFR 636.35 - Headphones and earphones.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 32 National Defense 4 2011-07-01 2011-07-01 false Headphones and earphones. 636.35 Section 636.35 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) LAW ENFORCEMENT AND... U.S. Government vehicle, POV, motorcycle, or other self-propelled two-wheel, three-wheel, or four...

32 CFR 636.35 - Headphones and earphones.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 32 National Defense 4 2013-07-01 2013-07-01 false Headphones and earphones. 636.35 Section 636.35 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) LAW ENFORCEMENT AND... U.S. Government vehicle, POV, motorcycle, or other self-propelled two-wheel, three-wheel, or four...

32 CFR 636.35 - Headphones and earphones.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 32 National Defense 4 2012-07-01 2011-07-01 true Headphones and earphones. 636.35 Section 636.35 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) LAW ENFORCEMENT AND... U.S. Government vehicle, POV, motorcycle, or other self-propelled two-wheel, three-wheel, or four...

32 CFR 636.35 - Headphones and earphones.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 32 National Defense 4 2010-07-01 2010-07-01 true Headphones and earphones. 636.35 Section 636.35 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) LAW ENFORCEMENT AND... U.S. Government vehicle, POV, motorcycle, or other self-propelled two-wheel, three-wheel, or four...

32 CFR 636.35 - Headphones and earphones.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 32 National Defense 4 2014-07-01 2013-07-01 true Headphones and earphones. 636.35 Section 636.35 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) LAW ENFORCEMENT AND... U.S. Government vehicle, POV, motorcycle, or other self-propelled two-wheel, three-wheel, or four...

Finite Element Models, Validation, and Results for Wheel Temperature and Elastic Thermal Stress Distributions

DOT National Transportation Integrated Search

1993-09-01

The report is the third of a series on the results of an engineering study of the effects of service loads on railroad vehicle wheels. The study was initiated in September 1991, in response to a request for assessment of contributing factors and corr...

15 CFR 315.2 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-01-01

... issued to implement it: (a) Act means the Automotive Products Trade Act of 1965 (79 Stat. 1016, 19 U.S.C... a three-wheeled vehicle) or an automotive truck tractor. (d) Bona fide motor-vehicle manufacturer...

Cost of Ownership and Well-to-Wheels Carbon Emissions/Oil Use of Alternative Fuels and Advanced Light-Duty Vehicle Technologies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Elgowainy, Mr. Amgad; Rousseau, Mr. Aymeric; Wang, Mr. Michael

2013-01-01

The U.S. Department of Energy (DOE), Argonne National Laboratory (Argonne), and the National Renewable Energy Laboratory (NREL) updated their analysis of the well-to-wheels (WTW) greenhouse gases (GHG) emissions, petroleum use, and the cost of ownership (excluding insurance, maintenance, and miscellaneous fees) of vehicle technologies that have the potential to significantly reduce GHG emissions and petroleum consumption. The analyses focused on advanced light-duty vehicle (LDV) technologies such as plug-in hybrid, battery electric, and fuel cell electric vehicles. Besides gasoline and diesel, alternative fuels considered include natural gas, advanced biofuels, electricity, and hydrogen. The Argonne Greenhouse Gases, Regulated Emissions, and Energy Usemore » in Transportation (GREET) and Autonomie models were used along with the Argonne and NREL H2A models.« less

Mobility analysis, simulation, and scale model testing for the design of wheeled planetary rovers

NASA Technical Reports Server (NTRS)

Lindemann, Randel A.; Eisen, Howard J.

1993-01-01

The use of computer based techniques to model and simulate wheeled rovers on rough natural terrains is considered. Physical models of a prototype vehicle can be used to test the correlation of the simulations in scaled testing. The computer approaches include a quasi-static planar or two dimensional analysis and design tool based on the traction necessary for the vehicle to have imminent mobility. The computer program modeled a six by six wheel drive vehicle of original kinematic configuration, called the Rocker Bogie. The Rocker Bogie was optimized using the quasi-static software with respect to its articulation parameters prior to fabrication of a prototype. In another approach used, the dynamics of the Rocker Bogie vehicle in 3-D space was modeled on an engineering workstation using commercial software. The model included the complex and nonlinear interaction of the tire and terrain. The results of the investigation yielded numerical and graphical results of the rover traversing rough terrain on the earth, moon, and Mars. In addition, animations of the rover excursions were also generated. A prototype vehicle was then used in a series of testbed and field experiments. Correspondence was then established between the computer models and the physical model. The results indicated the utility of the quasi-static tool for configurational design, as well as the predictive ability of the 3-D simulation to model the dynamic behavior of the vehicle over short traverses.

Development and Evaluation of the Stingray, an Amphibious Maritime Interdiction Operations Unmanned Ground Vehicle

DTIC Science & Technology

2014-05-01

of Ships], Charles Griffin and Company, London, 246-261 (1908). [6] Volpich, H. & Bridge, I . C., “Paddle Wheels Pt 1: Preliminary Model Experiments...Transactions of the Institution of Engineers and Shipbuilders in Scotland, 327-380 (1955). [7] Volpich, H. & Bridge, I . C., “Paddle Wheels...Bridge, I . C., “Paddle Wheels Pt III: Ship/Model Correlation,” Transactions of the Institution of Engineers and Shipbuilders in Scotland, 512-550

Multibody dynamics simulation of an all-wheel-drive motorcycle for handling and energy efficiency investigations

NASA Astrophysics Data System (ADS)

Griffin, J. W.; Popov, A. A.

2018-07-01

It is now possible, through electrical, hydraulic or mechanical means, to power the front wheel of a motorcycle. The aim of this is often to improve performance in limit-handling scenarios including off-road low-traction conditions and on-road high-speed cornering. Following on from research into active torque distribution in 4-wheeled vehicles, the possibility exists for efficiency improvements to be realised by reducing the total amount of energy dissipated as slip at the wheel-road contact. This paper presents the results of an investigation into the effect that varying the torque distribution ratio has on the energy consumption of the two-wheeled vehicle. A 13-degree of freedom multibody model was created, which includes the effects of suspension, aerodynamics and gyroscopic bodies. SimMechanics, from the MathWorks?, is used for automatic generation of equations of motion and time-domain simulation, in conjunction with MATLAB and Simulink. A simple driver model is used to control the speed and yaw rate of the motorcycle. The handling characteristics of the motorcycle are quantitatively analysed, and the impact of torque distribution on energy consumption is considered during straight line and cornering situations. The investigation has shown that only a small improvement in efficiency can be made by transferring a portion of the drive torque to the front wheel. Tyre longevity could be improved by reduced slip energy dissipation.

Sensor set-up for wireless measurement of automotive rim and wheel parameters in laboratory conditions

NASA Astrophysics Data System (ADS)

Borecki, M.; Prus, P.; Korwin-Pawlowski, M. L.; Rychlik, A.; Kozubel, W.

2017-08-01

Modern rims and wheels are tested at the design and production stages. Tests can be performed in laboratory conditions and on the ride. In the laboratory, complex and costly equipment is used, as for example wheel balancers and impact testers. Modern wheel balancers are equipped with electronic and electro-mechanical units that enable touch-less measurement of dimensions, including precision measurement of radial and lateral wheel run-out, automatic positioning and application of the counterweights, and vehicle wheel set monitoring - tread wear, drift angles and run-out unbalance. Those tests are performed by on-wheel axis measurements with laser distance meters. The impact tester enables dropping of weights from a defined height onto a wheel. Test criteria are the loss of pressure of the tire and generation of cracks in the wheel without direct impact of the falling weights. In the present paper, a set up composed of three accelerometers, a temperature sensor and a pressure sensor is examined as the base of a wheel tester. The sensor set-up configuration, on-line diagnostic and signal transmission are discussed.

Risk of thoracic injury from direct steering wheel impact in frontal crashes.

PubMed

Chen, Rong; Gabler, Hampton C

2014-06-01

The combination of airbag and seat belt is considered to be the most effective vehicle safety system. However, despite the widespread availability of airbags and a belt use rate of more than 85%, US drivers involved in crashes continue to be at risk of serious thoracic injury. The objective of this study was to determine the influence of steering wheel deformation on driver injury risk in frontal automobile crash. The analysis is based on cases extracted from the National Automotive Sampling System Crashworthiness Data System database for case years 1993 to 2011. The approach was to compare the adjusted odds of frontal crash injury experienced by drivers in vehicles with and without steering wheel deformation. Among frontal crash cases with belted drivers, observable steering wheel deformation occurred in less than 4% of all cases but accounted for 30% of belted drivers with serious (Abbreviated Injury Scale [AIS] score, 3+) thoracic injuries. Similarly, steering wheel deformation occurred in approximately 13% of unbelted drivers but accounted for 60% of unbelted drivers with serious thoracic injuries. Belted drivers in frontal crashes with steering wheel deformation were found to have two times greater odds of serious thoracic injury. Unbelted drivers were found to have four times greater odds of serious thoracic injury in crashes with steering wheel deformation. In frontal crashes, steering wheel deformation was more likely to occur in unbelted drivers than belted drivers, as well as higher severity crashes and with heavier drivers. The results of the present study show that airbag deployment and seat belt restraint do not completely eliminate the possibility of steering wheel contact. Even with the most advanced restraint systems, there remains an opportunity for further reduction in thoracic injury by continued enhancement to the seat belt and airbag systems. Furthermore, the results showed that steering wheel deformation is an indicator of potential serious thoracic injury and can be useful to prehospital personnel in improving the diagnosis of serious injuries. Prognostic study, level III.

ATHLETE: Lunar Cargo Handling for International Lunar Exploration

NASA Technical Reports Server (NTRS)

Wilcox, Brian H.

2010-01-01

As part of the Human-Robot Systems Project within the NASA Exploration Technology Development Program, the Jet Propulsion Laboratory is developing a vehicle called ATHLETE: the All-Terrain Hex-Limbed Extra-Terrestrial Explorer. The basic idea of ATHLETE is to have six relatively small wheels on the ends of legs. The small wheels and associated drive actuators are much less massive than the larger wheels and gears needed for an "all terrain" vehicle that cannot "walk" out of extreme terrain. The mass savings for the wheels and wheel actuators is greater than the mass penalty of the legs, for a net mass savings. Starting in 2009, NASA became engaged in detailed architectural studies for international discussions with the European Space Agency (ESA), the Japanese Space Agency (JAXA), and the Canadian Space Agency (CSA) under the auspices of the International Architecture Working Group (IAWG). ATHLETE is considered in most of the campaign options considered, providing a way to offload cargo from large Altair-class landers (having a cargo deck 6+ meters above the surface) as well as offloading international landers launched on Ariane-5 or H-2 launch vehicles. These international landers would carry provisions as well as scientific instruments and/or small rovers that would be used by international astronauts as part of an international effort to explore the moon.Work described in this paper includes architectural studies in support of the international missions as well as field testing of a half-scale ATHLETE prototype performing cargo offloading from a lander mockup, along with multi-kilometer traverse, climbing over greater than 1 m rocks, tool use, etc.

49 CFR 523.3 - Automobile.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 6 2011-10-01 2011-10-01 false Automobile. 523.3 Section 523.3 Transportation..., DEPARTMENT OF TRANSPORTATION VEHICLE CLASSIFICATION § 523.3 Automobile. (a) An automobile is any 4-wheeled... pounds and less than 10,000 pounds gross vehicle weight are determined to be automobiles: (1) Vehicles...

49 CFR 523.3 - Automobile.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 6 2013-10-01 2013-10-01 false Automobile. 523.3 Section 523.3 Transportation..., DEPARTMENT OF TRANSPORTATION VEHICLE CLASSIFICATION § 523.3 Automobile. (a) An automobile is any 4-wheeled... pounds and less than 10,000 pounds gross vehicle weight are determined to be automobiles: (1) Vehicles...

49 CFR 523.3 - Automobile.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 6 2012-10-01 2012-10-01 false Automobile. 523.3 Section 523.3 Transportation..., DEPARTMENT OF TRANSPORTATION VEHICLE CLASSIFICATION § 523.3 Automobile. (a) An automobile is any 4-wheeled... pounds and less than 10,000 pounds gross vehicle weight are determined to be automobiles: (1) Vehicles...

49 CFR 523.3 - Automobile.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 6 2014-10-01 2014-10-01 false Automobile. 523.3 Section 523.3 Transportation..., DEPARTMENT OF TRANSPORTATION VEHICLE CLASSIFICATION § 523.3 Automobile. (a) An automobile is any 4-wheeled... pounds and less than 10,000 pounds gross vehicle weight are determined to be automobiles: (1) Vehicles...

49 CFR 523.3 - Automobile.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 6 2010-10-01 2010-10-01 false Automobile. 523.3 Section 523.3 Transportation..., DEPARTMENT OF TRANSPORTATION VEHICLE CLASSIFICATION § 523.3 Automobile. (a) An automobile is any 4-wheeled... pounds and less than 10,000 pounds gross vehicle weight are determined to be automobiles: (1) Vehicles...

Effect of discrete track support by sleepers on rail corrugation at a curved track

NASA Astrophysics Data System (ADS)

Jin, X. S.; Wen, Z. F.

2008-08-01

The paper investigates into the effect of discrete track support by sleepers on the initiation and development of rail corrugation at a curved track when a railway vehicle passes through using a numerical method. The numerical method considers a combination of Kalker's rolling contact theory with non-Hertzian form, a linear frictional work model and a dynamics model of a half railway vehicle coupled with the curved track. The half-vehicle has a two-axle bogie and doubled suspension systems. It is treated as a full dynamic rigid multi-body model. In the track model, an Euler beam is used to model the rail, and the discrete track support by sleepers moving backward with respect to the vehicle running direction is considered to simulate the effect of the discrete sleeper support on the wheels/rails in rolling contact when the vehicle moves on the track. The sleeper is treated as a rigid body and the ballast bed is replaced with equivalent mass bodies. The numerical analysis exams in detail the variations of wheel/rail normal loads, the creepages, and the rail wear volume along the curved track. Their variations are much concerned with the discrete track support. The numerical results show that the discrete track support causes the fluctuating of the normal loads and creepages at a few frequencies. These frequencies comprise the passing frequency of the sleepers and the excited track resonant frequencies, which are higher than the sleeper passing frequency. Consequently, rail corrugation with several wavelengths initiates and develops. Also the results show that the contact vibrating between the curved rails and the four wheels of the same bogie has different frequencies. In this way, the different key frequencies to be excited play an important role in the initiation and development of curved rail corrugation. Therefore, the corrugations caused by the four wheels of the same bogie present different wavelengths. The paper shows and discusses the depths of the initial corrugations caused by the four wheels of the same bogie, at the entering transition curve, the circle curve and the exit transition curve of the curved track, respectively.

Identifying cognitive distraction using steering wheel reversal rates.

PubMed

Kountouriotis, Georgios K; Spyridakos, Panagiotis; Carsten, Oliver M J; Merat, Natasha

2016-11-01

The influence of driver distraction on driving performance is not yet well understood, but it can have detrimental effects on road safety. In this study, we examined the effects of visual and non-visual distractions during driving, using a high-fidelity driving simulator. The visual task was presented either at an offset angle on an in-vehicle screen, or on the back of a moving lead vehicle. Similar to results from previous studies in this area, non-visual (cognitive) distraction resulted in improved lane keeping performance and increased gaze concentration towards the centre of the road, compared to baseline driving, and further examination of the steering control metrics indicated an increase in steering wheel reversal rates, steering wheel acceleration, and steering entropy. We show, for the first time, that when the visual task is presented centrally, drivers' lane deviation reduces (similar to non-visual distraction), whilst measures of steering control, overall, indicated more steering activity, compared to baseline. When using a visual task that required the diversion of gaze to an in-vehicle display, but without a manual element, lane keeping performance was similar to baseline driving. Steering wheel reversal rates were found to adequately tease apart the effects of non-visual distraction (increase of 0.5° reversals) and visual distraction with offset gaze direction (increase of 2.5° reversals). These findings are discussed in terms of steering control during different types of in-vehicle distraction, and the possible role of manual interference by distracting secondary tasks. Copyright © 2016 Elsevier Ltd. All rights reserved.

49 CFR 393.130 - What are the rules for securing heavy vehicles, equipment and machinery?

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 5 2010-10-01 2010-10-01 false What are the rules for securing heavy vehicles... heavy vehicles, equipment and machinery? (a) Applicability. The rules in this section apply to the transportation of heavy vehicles, equipment and machinery which operate on wheels or tracks, such as front end...

Research on squeal noise of tread brake system in rail freight vehicle

NASA Astrophysics Data System (ADS)

Zhang, Jun; Li, Yong-hua; Fang, Ji; Zhao, Wen-zhong

2017-07-01

Brake squeal is a result of a unstable flutter from brake system, it results to the noise pollution in railway side and excessive wear of wheel tread. A finite element model of brake system for rail freight vehicle is set up, the contact and friction between the brake shoe and wheel tread is considered, the complex modals of brake system are calculated, the possibility of happening chatter and squeal noise are analyzed. The results show that the pressure angle or the brake force direction have a important influence on the unstable chatter and squeal noise, the more greater the pressure angle deviates from the wheel center, the more greater the possibility of happening chatter and squeal noise is, and the possibility of happening chatter and squeal noise is also increased along with the addition of friction factor.

High-Mobility Multipurpose Wheeled Vehicle Rollover Accidents and Injuries to U.S. Army Soldiers by Reported Occupant Restraint Use, 1992-2013.

PubMed

Lo, Michael C; Giffin, Robert P; Pakulski, Kraig A; Davis, W Sumner; Bernstein, Stephen A; Wise, Daniel V

2017-05-01

The high-mobility multipurpose wheeled vehicle (HMMWV) is a light military tactical vehicle. During Operation Iraqi Freedom and Operation Enduring Freedom, the U.S. Army modified the HMMWV into a combat vehicle by adding vehicle armor, which made the vehicle more difficult to control and more likely to roll over. Consequently, reports of fatal rollover accidents involving up-armored HMMWVs began to accumulate during the up-armoring period (August 2003 to April 2005). Furthermore, the lack of occupant restraint use prevalent in a predominantly young, male, and enlisted military population compounded the injuries resulting from these accidents. In this retrospective case series analysis, we describe the characteristics of U.S. Army HMMWV rollover accidents, occupants, and injuries reported worldwide from fiscal year 1992 to 2013 based on reported occupant restraint use. We conducted all analyses using Microsoft Excel 2010 and SAS version 9.1. Because this analysis does not constitute human subjects research, no institutional review board review was required. First, we obtained U.S. Army HMMWV accident records from the U.S. Army Combat Readiness Center, and selected those records indicating a HMMWV rollover had occurred. Next, we successively deduplicated the records at the accident, vehicle, occupant, and injury levels for descriptive analysis of characteristics at each level. For each occupant position, we calculated relative, attributable, and population attributable risks of nonfatal and fatal injury based on reported occupant restraint use. Finally, we analyzed body part injured and nature of injury to characterize the injury patterns that HMMWV occupants in each position sustained based on restraint use. We performed a χ 2 test of homogeneity to assess differences in injury patterns between restrained and unrestrained occupants. A total of 819 U.S. Army HMMWV rollover accidents worldwide were reported from October 1991 through May 2013 involving 821 HMMWVs and 1,395 occupants (828 nonfatally injured, 151 fatally injured, and 416 noninjured). Thirty-five percent of more severe (class A and B) accidents involved the M1114 up-armored variant, whereas 32% of less severe (class C and D) accidents involved the M998 nonarmored variant. Unrestrained occupants were 20% more likely to be nonfatally injured and 5.6 times more likely to be fatally injured than were restrained occupants. Among unrestrained occupants, restraint use could have potentially saved 82% of lives lost. Among all occupants involved in a HMMWV rollover, an estimated 56% of fatalities could have been prevented by restraint use. Unrestrained drivers and vehicle commanders had greater than expected torso injuries, while restrained vehicle commanders and passengers had greater than expected upper extremity injuries. Unrestrained drivers had greater than expected fractures, whereas restrained drivers and vehicle commanders had greater than expected sprains/strains. While reporting bias may exist, nevertheless these results show that occupant restraint use confers substantial life-saving protection to HMMWV occupants in rollover accidents. Therefore, commanders, safety officers, and peers should continue to promote and enforce restraint use consistently during all Army ground operations and training involving HMMWVs. Doing so will save Soldiers' lives in rollover accidents during the remaining years of the HMMWV program. Reprint & Copyright © 2017 Association of Military Surgeons of the U.S.

Anti-lock braking system (ABS) and regenerative braking system (RBS) in hybrid electric vehicle for smart transportation system

NASA Astrophysics Data System (ADS)

Evuri, Geetha Reddy; Rao, G. Srinivasa; Reddy, T. Ramasubba; Reddy, K. Srinivasa

2018-04-01

Pulse width modulation (PWM) based (a non-consistent) breaking system is used to keep the wheels from being bolted in the proposed antilock breaking system (ABS). Using this method a better hold of the street by wheels is possible and halting separations likewise diminish essentially particularly on precarious street surfaces like frosty or wet streets. The active vitality of the wheel is by and large lost amid braking as warmth because of grinding among brake cushions. This vitality can be recuperated using regenerative braking systems (RBS). In this strategy, the overabundance vitality is put away incidentally in capacitor banks before it gets changed over to warm vitality and is squandered. This framework delays the battery life by reviving the battery utilizing the put away vitality. Subsequently the mileage of the electric vehicle likewise increments as it can travel more separation in a solitary battery charge. These two techniques together help make electric vehicle vitality productive and more secure and less demanding to utilize subsequently anticipating and diminishing the quantity of mischance's.

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

NASA Astrophysics Data System (ADS)

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

2016-11-01

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

40 CFR 86.136-90 - Engine starting and restarting.

Code of Federal Regulations, 2010 CFR

2010-07-01

... started. If necessary, braking may be employed to keep the drive wheels from turning. (c) If the vehicle... petroleum-fueled diesel vehicles and the particulate sampling system when testing methanol-fueled diesel... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES Emission...

Analyses of rail vehicle dynamics in support of development of the wheel rail dynamics research facility

DOT National Transportation Integrated Search

1973-06-30

The development of experimental facilities for rail vehicle testing at the DOT High Speed Ground Test Center is being complemented by analytical studies. The purpose of this effort has been to gain insight into the dynamics of rail vehicles to guide ...

75 FR 44948 - California State Motor Vehicle Pollution Control Standards; Within-the-Scope Determination for...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-30

... amendments to its evaporative emission test procedures, four-wheel drive dynamometer provisions, and vehicle... manufacturer has certified vehicles using an alternative running loss test procedure, CARB may conduct... manufacturer's approved alternative running loss test procedure; (3) provide manufacturers an option to use an...

Study and Test to Confirm Automobile Drivetrain Components to Improve Fuel Economy : Volume 1. History of the Automobile Transmission in the United States

DOT National Transportation Integrated Search

1979-05-01

Since the earliest days of the motor car, engineers have tinkered together various means of connecting the engine to the ground. While the wheel rapidly became the norm for the ground/vehicle interface, many different engine/wheel coupling techniques...

Hybrid: Passing

Science.gov Websites

accelerating or when additional power is needed, the gasoline engine and electric motor are both used to propel . The car is passing another vehicle. There are red arrows flowing from the gasoline engine to the front wheels. There are blue arrows flowing from the battery to the electric engine to the front wheels. Main

49 CFR 213.333 - Automated vehicle-based inspection systems.

Code of Federal Regulations, 2014 CFR

2014-10-01

... the contact point of wheels carrying a vertical load of no less than 10 kips per wheel, unless... enable field forces to easily locate indicated exceptions. (f) Following a track inspection performed by... reference loads of 16 kips of lateral force and 33 kips of vertical force. (j) As further specified for the...

49 CFR 213.333 - Automated vehicle-based inspection systems.

Code of Federal Regulations, 2013 CFR

2013-10-01

... the contact point of wheels carrying a vertical load of no less than 10 kips per wheel, unless... enable field forces to easily locate indicated exceptions. (f) Following a track inspection performed by... reference loads of 16 kips of lateral force and 33 kips of vertical force. (j) As further specified for the...

49 CFR 571.101 - Standard No. 101; Controls and displays.

Code of Federal Regulations, 2013 CFR

2013-10-01

... accessibility, visibility and recognition of motor vehicle controls, telltales and indicators, and to facilitate... pressing on the center of the face plane of the steering wheel hub; or for a turn signal control that is operated in a plane essentially parallel to the face plane of the steering wheel in its normal driving...

49 CFR 571.101 - Standard No. 101; Controls and displays.

Code of Federal Regulations, 2010 CFR

2010-10-01

... accessibility, visibility and recognition of motor vehicle controls, telltales and indicators, and to facilitate... pressing on the center of the face plane of the steering wheel hub; or for a turn signal control that is operated in a plane essentially parallel to the face plane of the steering wheel in its normal driving...

49 CFR 571.101 - Standard No. 101; Controls and displays.

Code of Federal Regulations, 2014 CFR

2014-10-01

... accessibility, visibility and recognition of motor vehicle controls, telltales and indicators, and to facilitate... pressing on the center of the face plane of the steering wheel hub; or for a turn signal control that is operated in a plane essentially parallel to the face plane of the steering wheel in its normal driving...

49 CFR 571.101 - Standard No. 101; Controls and displays.

Code of Federal Regulations, 2012 CFR

2012-10-01

... accessibility, visibility and recognition of motor vehicle controls, telltales and indicators, and to facilitate... pressing on the center of the face plane of the steering wheel hub; or for a turn signal control that is operated in a plane essentially parallel to the face plane of the steering wheel in its normal driving...

49 CFR 571.101 - Standard No. 101; Controls and displays.

Code of Federal Regulations, 2011 CFR

2011-10-01

... accessibility, visibility and recognition of motor vehicle controls, telltales and indicators, and to facilitate... pressing on the center of the face plane of the steering wheel hub; or for a turn signal control that is operated in a plane essentially parallel to the face plane of the steering wheel in its normal driving...

Integrated Fault Diagnosis Algorithm for Motor Sensors of In-Wheel Independent Drive Electric Vehicles

PubMed Central

Jeon, Namju; Lee, Hyeongcheol

2016-01-01

An integrated fault-diagnosis algorithm for a motor sensor of in-wheel independent drive electric vehicles is presented. This paper proposes a method that integrates the high- and low-level fault diagnoses to improve the robustness and performance of the system. For the high-level fault diagnosis of vehicle dynamics, a planar two-track non-linear model is first selected, and the longitudinal and lateral forces are calculated. To ensure redundancy of the system, correlation between the sensor and residual in the vehicle dynamics is analyzed to detect and separate the fault of the drive motor system of each wheel. To diagnose the motor system for low-level faults, the state equation of an interior permanent magnet synchronous motor is developed, and a parity equation is used to diagnose the fault of the electric current and position sensors. The validity of the high-level fault-diagnosis algorithm is verified using Carsim and Matlab/Simulink co-simulation. The low-level fault diagnosis is verified through Matlab/Simulink simulation and experiments. Finally, according to the residuals of the high- and low-level fault diagnoses, fault-detection flags are defined. On the basis of this information, an integrated fault-diagnosis strategy is proposed. PMID:27973431

Design of safety-oriented control allocation strategies for overactuated electric vehicles

NASA Astrophysics Data System (ADS)

de Castro, Ricardo; Tanelli, Mara; Esteves Araújo, Rui; Savaresi, Sergio M.

2014-08-01

The new vehicle platforms for electric vehicles (EVs) that are becoming available are characterised by actuator redundancy, which makes it possible to jointly optimise different aspects of the vehicle motion. To do this, high-level control objectives are first specified and solved with appropriate control strategies. Then, the resulting virtual control action must be translated into actual actuator commands by a control allocation layer that takes care of computing the forces to be applied at the wheels. This step, in general, is quite demanding as far as computational complexity is considered. In this work, a safety-oriented approach to this problem is proposed. Specifically, a four-wheel steer EV with four in-wheel motors is considered, and the high-level motion controller is designed within a sliding mode framework with conditional integrators. For distributing the forces among the tyres, two control allocation approaches are investigated. The first, based on the extension of the cascading generalised inverse method, is computationally efficient but shows some limitations in dealing with unfeasible force values. To solve the problem, a second allocation algorithm is proposed, which relies on the linearisation of the tyre-road friction constraints. Extensive tests, carried out in the CarSim simulation environment, demonstrate the effectiveness of the proposed approach.

Analysis of Non-Tactical Vehicle Utilization at Fort Carson Colorado

DTIC Science & Technology

2012-01-01

regenerative braking energy recovery. The mass of the vehicles monitored in this study was not known. However, some useful information may be... regenerative energy recovery potential for specific duty cycles was also quantified through a cumulative assessment of the number and severity of deceleration...extracted on usage time, distance, vehicle speed and geographic location in order to compare vehicle driving profiles. The regenerative energy recovery

Ground Systems Integration Domain (GSID) Materials for Ground Platforms

DTIC Science & Technology

2010-09-20

Vehicles • Heavy Brigade Combat Team • Strykers • MRAPs • Ground Combat Vehicles (Future) Tactical Vehicles • HMMWVs • Trailers • Heavy, Medium and...efficient structural material solutions • Signature management, electromagnetic shielding over potentially non-metallic surfaces • Diagnostics...Occupant-Centric Survivability Focused): 1. 4500 lbs + trailer towing capacity; 4-6 man crew compartmentPayload 2. 14,000 lb curb vehicle weightPerformance

Off-road motorbike performance analysis using a rear semi-active suspension

NASA Astrophysics Data System (ADS)

Lozoya-Santos, Jorge de J.; Cervantes-Muñoz, Damián.; Ramírez Mendoza, Ricardo

2015-04-01

The topic of this paper is the analysis of a control system for a semi active rear suspension in an off-road 2-wheel vehicle. Several control methods are studied, as well as the recently proposed Frequency Estimation Based (FEB) algorithm. The test motorcycle dynamics, as well as the passive, semi active, and the algorithm controlled shock absorber models are loaded into BikeSim, a professional two-wheeled vehicle simulation software, and tested in several road conditions. The results show a detailed comparison of the theoretical performance of the different control approaches in a novel environment for semi active dampers.

An improved lateral control wheel steering law for the Transport Systems Research Vehicle (TSRV)

NASA Technical Reports Server (NTRS)

Ragsdale, W. A.

1992-01-01

A lateral control wheel steering law with improved performance was developed for the Transport Systems Research Vehicle (TSRV) simulation and used in the Microwave Landing System research project. The control law converted rotational hand controller inputs into roll rate commands, manipulated ailerons, spoilers, and the rudder to achieve the desired roll rates. The system included automatic turn coordination, track angle hold, and autopilot/autoland modes. The resulting control law produced faster roll rates (15 degrees/sec), quicker response to command reversals, and safer bank angle limits, while using a more concise program code.

Effect of yaw angle on steering forces for the lunar roving vehicle wheel

NASA Technical Reports Server (NTRS)

Green, A. J.

1974-01-01

A series of tests was conducted with a Lunar Roving Vehicle (LRV) wheel operating at yaw angles ranging from -5 to +90 deg. The load was varied from 42 to 82 lb (187 to 365 N), and the speed was varied from 3.5 to 10.0 ft/sec (1.07 to 3.05 m/sec). It was noted that speed had an effect on side thrust and rut depth. Side thrust, rut depth, and skid generally increased as the yaw angle increased. For the range of loads used, the effect of load on performance was not significant.

Development and validation of a new kind of coupling element for wheel-hub motors

NASA Astrophysics Data System (ADS)

Perekopskiy, Sergey; Kasper, Roland

2018-05-01

For the automotive industry, electric powered vehicles are becoming an increasingly relevant factor in the competition against climate change. Application of one special example - a wheel-hub motor, for electric powered vehicle can support this challenge. Patented slotless air gap winding invented at the chair of mechatronics of the Otto von Guericke University Magdeburg has great application potential in constantly growing e-mobility field, especially for wheel-hub motors based on this technology due to its advantages, such as a high gravimetric power density and high efficiency. However, advantages of this technology are decreased by its sensibility to the loads out of driving maneuvers by dimensional variations of air gap consistency. This article describes the development and validation of a coupling element for the designed wheel-hub motor. To find a suitable coupling concept first the assembly structure of the motor was analyzed and developed design of the coupling element was checked. Based on the geometry of the motor and wheel a detailed design of the coupling element was generated. The analytical approach for coupling element describes a potential of the possible loads on the coupling element. The FEM simulation of critical load cases for the coupling element validated results of the analytical approach.

A Traction Control Strategy with an Efficiency Model in a Distributed Driving Electric Vehicle

PubMed Central

Lin, Cheng

2014-01-01

Both active safety and fuel economy are important issues for vehicles. This paper focuses on a traction control strategy with an efficiency model in a distributed driving electric vehicle. In emergency situation, a sliding mode control algorithm was employed to achieve antislip control through keeping the wheels' slip ratios below 20%. For general longitudinal driving cases, an efficiency model aiming at improving the fuel economy was built through an offline optimization stream within the two-dimensional design space composed of the acceleration pedal signal and the vehicle speed. The sliding mode control strategy for the joint roads and the efficiency model for the typical drive cycles were simulated. Simulation results show that the proposed driving control approach has the potential to apply to different road surfaces. It keeps the wheels' slip ratios within the stable zone and improves the fuel economy on the premise of tracking the driver's intention. PMID:25197697

A traction control strategy with an efficiency model in a distributed driving electric vehicle.

PubMed

Lin, Cheng; Cheng, Xingqun

2014-01-01

Both active safety and fuel economy are important issues for vehicles. This paper focuses on a traction control strategy with an efficiency model in a distributed driving electric vehicle. In emergency situation, a sliding mode control algorithm was employed to achieve antislip control through keeping the wheels' slip ratios below 20%. For general longitudinal driving cases, an efficiency model aiming at improving the fuel economy was built through an offline optimization stream within the two-dimensional design space composed of the acceleration pedal signal and the vehicle speed. The sliding mode control strategy for the joint roads and the efficiency model for the typical drive cycles were simulated. Simulation results show that the proposed driving control approach has the potential to apply to different road surfaces. It keeps the wheels' slip ratios within the stable zone and improves the fuel economy on the premise of tracking the driver's intention.

Traction drive automatic transmission for gas turbine engine driveline

DOEpatents

Carriere, Donald L.

1984-01-01

A transaxle driveline for a wheeled vehicle has a high speed turbine engine and a torque splitting gearset that includes a traction drive unit and a torque converter on a common axis transversely arranged with respect to the longitudinal centerline of the vehicle. The drive wheels of the vehicle are mounted on a shaft parallel to the turbine shaft and carry a final drive gearset for driving the axle shafts. A second embodiment of the final drive gearing produces an overdrive ratio between the output of the first gearset and the axle shafts. A continuously variable range of speed ratios is produced by varying the position of the drive rollers of the traction unit. After starting the vehicle from rest, the transmission is set for operation in the high speed range by engaging a first lockup clutch that joins the torque converter impeller to the turbine for operation as a hydraulic coupling.

Hybrid powertrain controller

DOEpatents

Jankovic, Miroslava; Powell, Barry Kay

2000-12-26

A hybrid powertrain for a vehicle comprising a diesel engine and an electric motor in a parallel arrangement with a multiple ratio transmission located on the torque output side of the diesel engine, final drive gearing connecting drivably the output shaft of transmission to traction wheels of the vehicle, and an electric motor drivably coupled to the final drive gearing. A powertrain controller schedules fuel delivered to the diesel engine and effects a split of the total power available, a portion of the power being delivered by the diesel and the balance of the power being delivered by the motor. A shifting schedule for the multiple ratio transmission makes it possible for establishing a proportional relationship between accelerator pedal movement and torque desired at the wheels. The control strategy for the powertrain maintains drivability of the vehicle that resembles drivability of a conventional spark ignition vehicle engine powertrain while achieving improved fuel efficiency and low exhaust gas emissions.

Physical processes in wheel-rail contact and its implications on vehicle-track interaction

NASA Astrophysics Data System (ADS)

Six, K.; Meierhofer, A.; Müller, G.; Dietmaier, P.

2015-05-01

Friction within the wheel-rail contact highly influences all aspects of vehicle-track interaction. Models describing this frictional behaviour are of high relevance, for example, for reliable predictions on drive train dynamics. It has been shown by experiments, that the friction at a certain position on rail is not describable by only one number for the coefficient of friction. Beside the contact conditions (existence of liquids, solid third bodies, etc.) the vehicle speed, normal loading and contact geometry are further influencing factors. State-of-the-art models are not able to account for this sufficiently. Thus, an Extended-Creep-Force-Model was developed taking into account effects from third body layers. This model is able to describe all considered effects. In this way, a significant improvement of the prediction quality with respect to all aspects of vehicle-track interaction is expected.

Braking and cornering studies on an air cushion landing system

NASA Technical Reports Server (NTRS)

Daugherty, R. H.

1983-01-01

An experimental investigation was conducted to evaluate several concepts for braking and steering a vehicle equipped with an air cushion landing system (ACLS). The investigation made use of a modified airboat equipped with an ACLS. Braking concepts were characterized by the average deceleration of the vehicle. Reduced lobe flow and cavity venting braking concepts were evaluated in this program. The cavity venting braking concept demonstrated the best performance, producing decelerations on the test vehicle on the same order as moderate braking with conventional wheel brakes. Steering concepts were evaluated by recording the path taken while attempting to follow a prescribed maneuver. The steering concepts evaluated included using rudders only, using differential lobe flow, and using rudders combined with a lightly loaded, nonsteering center wheel. The latter concept proved to be the most accurate means of steering the vehicle on the ACLS, producing translational deviations two to three times higher than those from conventional nose-gear steering. However, this concept was still felt to provide reasonably precise steering control for the ACLS-equipped vehicle.

Influence of wheel-rail contact modelling on vehicle dynamic simulation

NASA Astrophysics Data System (ADS)

Burgelman, Nico; Sichani, Matin Sh.; Enblom, Roger; Berg, Mats; Li, Zili; Dollevoet, Rolf

2015-08-01

This paper presents a comparison of four models of rolling contact used for online contact force evaluation in rail vehicle dynamics. Until now only a few wheel-rail contact models have been used for online simulation in multibody software (MBS). Many more models exist and their behaviour has been studied offline, but a comparative study of the mutual influence between the calculation of the creep forces and the simulated vehicle dynamics seems to be missing. Such a comparison would help researchers with the assessment of accuracy and calculation time. The contact methods investigated in this paper are FASTSIM, Linder, Kik-Piotrowski and Stripes. They are compared through a coupling between an MBS for the vehicle simulation and Matlab for the contact models. This way the influence of the creep force calculation on the vehicle simulation is investigated. More specifically this study focuses on the influence of the contact model on the simulation of the hunting motion and on the curving behaviour.

49 CFR 393.42 - Brakes required on all wheels.

Code of Federal Regulations, 2010 CFR

2010-10-01

... subject to this part is not required to be equipped with brakes if the axle weight of the towed vehicle does not exceed 40 percent of the sum of the axle weights of the towing vehicle. (4) Any full trailer... of the towed vehicle does not exceed 40 percent of the sum of the axle weights of the towing vehicle...

Energy efficiency analysis: biomass-to-wheel efficiency related with biofuels production, fuel distribution, and powertrain systems.

PubMed

Huang, Wei-Dong; Zhang, Y-H Percival

2011-01-01

Energy efficiency analysis for different biomass-utilization scenarios would help make more informed decisions for developing future biomass-based transportation systems. Diverse biofuels produced from biomass include cellulosic ethanol, butanol, fatty acid ethyl esters, methane, hydrogen, methanol, dimethyether, Fischer-Tropsch diesel, and bioelectricity; the respective powertrain systems include internal combustion engine (ICE) vehicles, hybrid electric vehicles based on gasoline or diesel ICEs, hydrogen fuel cell vehicles, sugar fuel cell vehicles (SFCV), and battery electric vehicles (BEV). We conducted a simple, straightforward, and transparent biomass-to-wheel (BTW) analysis including three separate conversion elements--biomass-to-fuel conversion, fuel transport and distribution, and respective powertrain systems. BTW efficiency is a ratio of the kinetic energy of an automobile's wheels to the chemical energy of delivered biomass just before entering biorefineries. Up to 13 scenarios were analyzed and compared to a base line case--corn ethanol/ICE. This analysis suggests that BEV, whose electricity is generated from stationary fuel cells, and SFCV, based on a hydrogen fuel cell vehicle with an on-board sugar-to-hydrogen bioreformer, would have the highest BTW efficiencies, nearly four times that of ethanol-ICE. In the long term, a small fraction of the annual US biomass (e.g., 7.1%, or 700 million tons of biomass) would be sufficient to meet 100% of light-duty passenger vehicle fuel needs (i.e., 150 billion gallons of gasoline/ethanol per year), through up to four-fold enhanced BTW efficiencies by using SFCV or BEV. SFCV would have several advantages over BEV: much higher energy storage densities, faster refilling rates, better safety, and less environmental burdens.

Energy Efficiency Analysis: Biomass-to-Wheel Efficiency Related with Biofuels Production, Fuel Distribution, and Powertrain Systems

PubMed Central

Huang, Wei-Dong; Zhang, Y-H Percival

2011-01-01

Background Energy efficiency analysis for different biomass-utilization scenarios would help make more informed decisions for developing future biomass-based transportation systems. Diverse biofuels produced from biomass include cellulosic ethanol, butanol, fatty acid ethyl esters, methane, hydrogen, methanol, dimethyether, Fischer-Tropsch diesel, and bioelectricity; the respective powertrain systems include internal combustion engine (ICE) vehicles, hybrid electric vehicles based on gasoline or diesel ICEs, hydrogen fuel cell vehicles, sugar fuel cell vehicles (SFCV), and battery electric vehicles (BEV). Methodology/Principal Findings We conducted a simple, straightforward, and transparent biomass-to-wheel (BTW) analysis including three separate conversion elements -- biomass-to-fuel conversion, fuel transport and distribution, and respective powertrain systems. BTW efficiency is a ratio of the kinetic energy of an automobile's wheels to the chemical energy of delivered biomass just before entering biorefineries. Up to 13 scenarios were analyzed and compared to a base line case – corn ethanol/ICE. This analysis suggests that BEV, whose electricity is generated from stationary fuel cells, and SFCV, based on a hydrogen fuel cell vehicle with an on-board sugar-to-hydrogen bioreformer, would have the highest BTW efficiencies, nearly four times that of ethanol-ICE. Significance In the long term, a small fraction of the annual US biomass (e.g., 7.1%, or 700 million tons of biomass) would be sufficient to meet 100% of light-duty passenger vehicle fuel needs (i.e., 150 billion gallons of gasoline/ethanol per year), through up to four-fold enhanced BTW efficiencies by using SFCV or BEV. SFCV would have several advantages over BEV: much higher energy storage densities, faster refilling rates, better safety, and less environmental burdens. PMID:21765941

Mathematical model of rolling an elastic wheel over deformable support base

NASA Astrophysics Data System (ADS)

Volskaia, V. N.; Zhileykin, M. M.; Zakharov, A. Y.

2018-02-01

One of the main direction of economic growth in Russia remains to be a speedy development of north and northeast regions that are the constituents of the 60 percent of the country territory. The further development of these territories requires new methods and technologies for solving transport and technological problems when off-road transportation of cargoes and people is conducting. One of the fundamental methods of patency prediction is imitation modeling of wheeled vehicles movement in different operating conditions. Both deformable properties of tires and physical and mechanical properties of the ground: normal tire deflection and gauge depth; variation of contact patch area depending on the load and pressure of air in the tire; existence of hysteresis losses in the tire material which are influencing on the rolling resistance due to friction processes between tire and ground in the contact patch; existence of the tangential reaction from the ground by entire contact area influence on the tractive patency. Nowadays there are two main trends in theoretical research of interaction wheeled propulsion device with ground: analytical method involving mathematical description of explored process and finite element method based on computational modeling. Mathematical models of interaction tire with the ground are used both in processes of interaction individual wheeled propulsion device with ground and researches of mobile vehicle dynamical models operated in specific road and climate conditions. One of the most significant imperfection of these models is the description of interaction wheel with flat deformable support base whereas profile of real support base surface has essential height of unevenness which is commensurate with radius of the wheel. The description of processes taking place in the ground under influence of the wheeled propulsion device using the finite element method is relatively new but most applicable lately. The application of this method allows to provide the most accurate description of the interaction process of a wheeled propulsion devices and the ground, also this method allows to define tension in the ground, deformation of the ground and the tire and ground’s compression. However, the high laboriousness of computations is essential shortcoming of that method therefore it’s hard to use these models as part of the general motion model of multi-axis wheeled vehicles. The purpose of this research is the elaboration of mathematical model of elastic wheel rolling over deformable rough support base taking into account the contact patch deformation. The mathematical model of rectilinear rolling an elastic wheel over rough deformable support base, taking into account variation of contact patch area and variation in the direction of the radial and tangential reactions also load bearing capacity of the ground, is developed. The efficiency of developed mathematical model of rectilinear rolling an elastic wheel over rough deformable support base is proved by the simulation methods.

Driver dependent factors and the risk of causing a collision for two wheeled motor vehicles

PubMed Central

Lardelli-Claret, P; Jimenez-Moleon, J; de Dios, Luna-del-... J; Garcia-Martin, M; Bueno-Cavanillas, A; Galvez-Vargas, R

2005-01-01

Objective: To assess the effect of driver dependent factors on the risk of causing a collision for two wheeled motor vehicles (TWMVs). Design: Case control study. Setting: Spain, from 1993 to 2002. Subjects: All drivers of TWMVs involved in the 181 551 collisions between two vehicles recorded in the Spanish registry which did not involve pedestrians, and in which at least one of the vehicles was a TWMV and only one driver had committed a driving infraction. The infractor and non-infractor drivers constituted the case and control groups, respectively. Main outcome measures: Logistic regression analyses were used to obtain crude and adjusted odds ratio estimates for each of the driver related factors recorded in the registry (age, sex, nationality, psychophysical factors, and speeding infractions, among others). Results: Inappropriate speed was the variable with the greatest influence on the risk of causing a collision, followed by excessive speed and driving under the influence of alcohol. Younger and older drivers, foreign drivers, and driving without a valid license were also associated with a higher risk of causing a collision. In contrast, helmet use, female sex, and longer time in possession of a driving license were associated with a lower risk. Conclusions: Although the main driver dependent factors related to the risk of causing a collision for a TWMV were similar to those documented for four wheeled vehicles, several differences in the pattern of associations support the need to study moped and motorcycle crashes separately from crashes involving other types of vehicles. PMID:16081752

Axle Lubricant Efficiency

DTIC Science & Technology

2014-05-09

state or reflect those of the United States Government or the DoA, and shall not be used for advertising or product endorsement purposes...Engine Control Module FMTV Family of Medium Tactical Vehicles GO Gear Oil GPS Global Positioning System GVW Gross Vehicle Weight HDO Heavy Duty Oil

Multi-functional Electric Module for a Vehicle

NASA Technical Reports Server (NTRS)

Waligora, Thomas M. (Inventor); Fraser-Chanpong, Nathan (Inventor); Figuered, Joshua M. (Inventor); Reed, Ryan (Inventor); Akinyode, Akinjide Akinniyi (Inventor); Spain, Ivan (Inventor); Dawson, Andrew D. (Inventor); Herrera, Eduardo (Inventor); Markee, Mason M. (Inventor); Bluethmann, William J. (Inventor)

2015-01-01

A multi-functional electric module (eModule) is provided for a vehicle having a chassis, a master controller, and a drive wheel having a propulsion-braking module. The eModule includes a steering control assembly, mounting bracket, propulsion control assembly, brake controller, housing, and control arm. The steering control assembly includes a steering motor controlled by steering controllers in response to control signals from the master controller. A mounting feature of the bracket connects to the chassis. The propulsion control assembly and brake controller are in communication with the propulsion-braking module. The control arm connects to the lower portion and contains elements of a suspension system, with the control arm being connectable to the drive wheel via a wheel input/output block. The controllers are responsive to the master controller to control a respective steering, propulsion, and braking function. The steering motor may have a dual-wound stator with windings controlled via the respective steering controllers.

Improving Odometric Accuracy for an Autonomous Electric Cart.

PubMed

Toledo, Jonay; Piñeiro, Jose D; Arnay, Rafael; Acosta, Daniel; Acosta, Leopoldo

2018-01-12

In this paper, a study of the odometric system for the autonomous cart Verdino, which is an electric vehicle based on a golf cart, is presented. A mathematical model of the odometric system is derived from cart movement equations, and is used to compute the vehicle position and orientation. The inputs of the system are the odometry encoders, and the model uses the wheels diameter and distance between wheels as parameters. With this model, a least square minimization is made in order to get the nominal best parameters. This model is updated, including a real time wheel diameter measurement improving the accuracy of the results. A neural network model is used in order to learn the odometric model from data. Tests are made using this neural network in several configurations and the results are compared to the mathematical model, showing that the neural network can outperform the first proposed model.

Modelling generalisation and power dissipation of flexible-wheel suspension concept for planetary surface vehicles

NASA Astrophysics Data System (ADS)

Cao, Dongpu; Khajepour, Amir; Song, Xubin

2011-08-01

Flexible-wheel (FW) suspension concept has been regarded to be one of the novel technologies for future planetary surface vehicles (PSVs). This study develops generalised models for fundamental stiffness and damping properties and power consumption characteristics of the FW suspension with and without considering wheel-hub dimensions. Compliance rolling resistance (CRR) coefficient is also defined and derived for the FW suspension. Based on the generalised models and two dimensionless measures, suspension properties are analysed for two FW suspension configurations. The sensitivity analysis is performed to investigate the effects of the design parameters and operating conditions on the CRR and power consumption characteristic of the FW suspension. The modelling generalisation permits analyses of fundamental properties and power consumption characteristics of different FW suspension designs in a uniform and very convenient manner, which would serve as a theoretical foundation for the design of FW suspensions for future PSVs.

Inertia coupling analysis of a self-decoupled wheel force transducer under multi-axis acceleration fields.

PubMed

Feng, Lihang; Lin, Guoyu; Zhang, Weigong; Dai, Dong

2015-01-01

Wheel force transducer (WFT), which measures the three-axis forces and three-axis torques applied to the wheel, is an important instrument in the vehicle testing field and has been extremely promoted by researchers with great interests. The transducer, however, is typically mounted on the wheel of a moving vehicle, especially on a high speed car, when abruptly accelerating or braking, the mass/inertia of the transducer/wheel itself will have an extra effect on the sensor response so that the inertia/mass loads will also be detected and coupled into the signal outputs. The effect which is considered to be inertia coupling problem will decrease the sensor accuracy. In this paper, the inertia coupling of a universal WFT under multi-axis accelerations is investigated. According to the self-decoupling approach of the WFT, inertia load distribution is solved based on the principle of equivalent mass and rotary inertia, thus then inertia impact can be identified with the theoretical derivation. The verification is achieved by FEM simulation and experimental tests. Results show that strains in simulation agree well with the theoretical derivation. The relationship between the applied acceleration and inertia load for both wheel force and moment is the approximate linear, respectively. All the relative errors are less than 5% which are within acceptable and the inertia loads have the maximum impact on the signal output about 1.5% in the measurement range.

Inertia Coupling Analysis of a Self-Decoupled Wheel Force Transducer under Multi-Axis Acceleration Fields

PubMed Central

Feng, Lihang; Lin, Guoyu; Zhang, Weigong; Dai, Dong

2015-01-01

Wheel force transducer (WFT), which measures the three-axis forces and three-axis torques applied to the wheel, is an important instrument in the vehicle testing field and has been extremely promoted by researchers with great interests. The transducer, however, is typically mounted on the wheel of a moving vehicle, especially on a high speed car, when abruptly accelerating or braking, the mass/inertia of the transducer/wheel itself will have an extra effect on the sensor response so that the inertia/mass loads will also be detected and coupled into the signal outputs. The effect which is considered to be inertia coupling problem will decrease the sensor accuracy. In this paper, the inertia coupling of a universal WFT under multi-axis accelerations is investigated. According to the self-decoupling approach of the WFT, inertia load distribution is solved based on the principle of equivalent mass and rotary inertia, thus then inertia impact can be identified with the theoretical derivation. The verification is achieved by FEM simulation and experimental tests. Results show that strains in simulation agree well with the theoretical derivation. The relationship between the applied acceleration and inertia load for both wheel force and moment is the approximate linear, respectively. All the relative errors are less than 5% which are within acceptable and the inertia loads have the maximum impact on the signal output about 1.5% in the measurement range. PMID:25723492

49 CFR 393.130 - What are the rules for securing heavy vehicles, equipment and machinery?

Code of Federal Regulations, 2012 CFR

2012-10-01

..., equipment and machinery? 393.130 Section 393.130 Transportation Other Regulations Relating to Transportation... heavy vehicles, equipment and machinery? (a) Applicability. The rules in this section apply to the transportation of heavy vehicles, equipment and machinery which operate on wheels or tracks, such as front end...

49 CFR 393.130 - What are the rules for securing heavy vehicles, equipment and machinery?

Code of Federal Regulations, 2011 CFR

2011-10-01

..., equipment and machinery? 393.130 Section 393.130 Transportation Other Regulations Relating to Transportation... heavy vehicles, equipment and machinery? (a) Applicability. The rules in this section apply to the transportation of heavy vehicles, equipment and machinery which operate on wheels or tracks, such as front end...

49 CFR 393.130 - What are the rules for securing heavy vehicles, equipment and machinery?

Code of Federal Regulations, 2013 CFR

2013-10-01

..., equipment and machinery? 393.130 Section 393.130 Transportation Other Regulations Relating to Transportation... heavy vehicles, equipment and machinery? (a) Applicability. The rules in this section apply to the transportation of heavy vehicles, equipment and machinery which operate on wheels or tracks, such as front end...

Smart infrared inspection system field operational test.

DOT National Transportation Integrated Search

2014-04-01

The Smart InfraRed Inspection System (SIRIS) is a tool designed to assist inspectors in determining which vehicles : passing through the system are in need of further inspection by measuring the thermal data from the wheel : components. As a vehicle ...

ATHLETE: A Cargo-Handling Vehicle for Solar System Exploration

NASA Technical Reports Server (NTRS)

Wilcox, Brian H.

2011-01-01

As part of the NASA Exploration Technology Development Program, the Jet Propulsion Laboratory is developing a vehicle called ATHLETE: the All-Terrain Hex-Limbed Extra-Terrestrial Explorer. Each vehicle is based on six wheels at the ends of six multi-degree-of-freedom limbs. Because each limb has enough degrees of freedom for use as a general-purpose leg, the wheels can be locked and used as feet to walk out of excessively soft or other extreme terrain. Since the vehicle has this alternative mode of traversing through or at least out of extreme terrain, the wheels and wheel actuators can be sized for nominal terrain. There are substantial mass savings in the wheel and wheel actuators associated with designing for nominal instead of extreme terrain. These mass savings are comparable-to or larger-than the extra mass associated with the articulated limbs. As a result, the entire mobility system, including wheels and limbs, can be about 25% lighter than a conventional mobility chassis. A side benefit of this approach is that each limb has sufficient degrees-of-freedom to use as a general-purpose manipulator (hence the name "limb" instead of "leg"). Our prototype ATHLETE vehicles have quick-disconnect tool adapters on the limbs that allow tools to be drawn out of a "tool belt" and maneuvered by the limb. A power-take-off from the wheel actuates the tools, so that they can take advantage of the 1+ horsepower motor in each wheel to enable drilling, gripping or other power-tool functions. Architectural studies have indicated that one useful role for ATHLETE in planetary (moon or Mars) exploration is to "walk" cargo off the payload deck of a lander and transport it across the surface. Recent architectural approaches are focused on the concept that the lander descent stage will use liquid hydrogen as a propellant. This is the highest performance chemical fuel, but it requires very large tanks. A natural geometry for the lander is to have a single throttleable rocket engine on the centerline at the bottom, and to have the propellant tanks arranged as compactly as possible around and above that engine, with nearly-straight structural load paths that carry the heavy LO2 tanks as well as the ascent stage or cargo on a top deck. (The requirement for exactly one descent engine stems from the need to avoid symmetry planes in the exhaust plume that can entrain surface particles and loft them up into the system at hypervelocity.) This geometry is especially attractive since abort considerations drive the ascent stage to have as much open space around it as possible, in case the ascent stage needs to fire away from an out-of-control descent stage. These considerations lead to a configuration where the cargo deck of the lander is relatively high off the ground (over 6 meters in current concepts, using a 10-meter diameter launch shroud). These considerations have led some observers to presume that there is a "lander offloading problem". ATHLETE has been demonstrated as a solution to this problem, walking cargo off the high deck. This paper describes the applicability of the ATHLETE concept to exploration of the moon, Mars and even to Near- Earth Objects. Recent field test results for long-range traverse are described, along with plans for testing in the simulated microgravity environment of a NEO.

On the dynamic response at the wheel axle of a pneumatic tire

NASA Astrophysics Data System (ADS)

Kung, L. E.; Soedel, W.; Yang, T. Y.

1986-06-01

A method for calculating the steady state displacement response and force transmission at the wheel axle of a pneumatic tire-suspension system due to a steady state force or displacement excitation at the tire to ground contact point is developed. The method requires the frequency responses (or receptances)_of both tire-wheel and suspension units. The frequency response of the tire-wheel unit is obtained by using the modal expansion method. The natural frequencies and mode shapes of the tire-wheel unit are obtained by using a geometrically non-linear, ring type, thin shell finite element of laminate composite. The frequency response of the suspension unit is obtained analytically. These frequency responses are used to calculate the force-input and the displacement-input responses at the wheel axle. This method allows the freedom of designing a vehicle and its tires independently and still achieving optimum dynamic performance.

A third-order approximation method for three-dimensional wheel-rail contact

NASA Astrophysics Data System (ADS)

Negretti, Daniele

2012-03-01

Multibody train analysis is used increasingly by railway operators whenever a reliable and time-efficient method to evaluate the contact between wheel and rail is needed; particularly, the wheel-rail contact is one of the most important aspects that affects a reliable and time-efficient vehicle dynamics computation. The focus of the approach proposed here is to carry out such tasks by means of online wheel-rail elastic contact detection. In order to improve efficiency and save time, a main analytical approach is used for the definition of wheel and rail surfaces as well as for contact detection, then a final numerical evaluation is used to locate contact. The final numerical procedure consists in finding the zeros of a nonlinear function in a single variable. The overall method is based on the approximation of the wheel surface, which does not influence the contact location significantly, as shown in the paper.

Impact of a helmet law on two wheel motor vehicle crash mortality in a southern European urban area

PubMed Central

Ferrando, J.; Plasencia, A.; Oros, M.; Borrell, C.; Kraus, J.

2000-01-01

Background—In Spain, a federal road safety law went into effect in the fall of 1992 extending to urban areas the unrestricted use of safety helmets by all two wheel motor vehicle occupants. Objectives—To assess the effect of the law in reducing fatal motorcycle crash injuries; to estimate the number of lives saved; and to determine changes in the distribution of severity and anatomical location of injuries. Methods—Pre-test/post-test design of all deaths of two wheel motor vehicle occupants from 1990–92 (pre-law period) and from 1993–95 (post-law period) detected by the Barcelona Forensic Institute and the city police department. Injuries were coded using the 1990 version of the abbreviated injury scale. Poisson regression methods were used to model trends in mortality ratios and to provide estimates of the number of lives saved. Results—Between 1993 and 1995, 35 lives of two wheel motor vehicle occupants were spared, representing a decrease of 25% in the observed motorcycle crash mortality in the post-law period when compared with what would be expected if no such law had gone into effect. The proportion of deaths with severe head injuries was also reduced from 76% to 67% in the post-law period. Conclusions—This study offers the first evaluation of a helmet law using combined forensic and police data in a large south European urban area where there is widespread use of motorcycles. Our results confirm the effectiveness of the helmet law, as measured by the reduction in the number of deaths and mortality ratios after the law implementation. The findings reinforce the public health benefits of mandatory non-restricted motorcycle and moped helmet use, even in urban areas with lower traffic speeds. PMID:11003182

Mars Exploration Rovers as Virtual Instruments for Determination of Terrain Roughness and Physical Properties

NASA Technical Reports Server (NTRS)

Arvidson, R. E.; Lindemann, R.; Matijevic, J.; Richter, L.; Sullivan, R.; Haldemann, A.; Anderson, R.; Snider, N.

2003-01-01

The two 2003 Mars Exploration Rovers (MERs), in combination with the Athena Payload, will be used as virtual instrument systems to infer terrain properties during traverses, in addition to using the rover wheels to excavate trenches, exposing subsurface materials for remote and in-situ observations. The MERs are being modeled using finite element-based rover system transfer functions that utilize the distribution of masses associated with the vehicle, together with suspension and wheel dynamics, to infer surface roughness and mechanical properties from traverse time series data containing vehicle yaw, pitch, roll, encoder counts, and motor currents. These analyses will be supplemented with imaging and other Athena Payload measurements. The approach is being validated using Sojourner data, the FIDO rover, and experiments with MER testbed vehicles. In addition to conducting traverse science and associated analyses, trenches will be excavated by the MERs to depths of approximately 10-20 cm by locking all but one of the front wheels and rotating that wheel backwards so that the excavated material is piled up on the side of the trench away from the vehicle. Soil cohesion and angle of internal friction will be determined from the trench telemetry data. Emission spectroscopy and in-situ observations will be made using the Athena payload before and after imaging. Trenching and observational protocols have been developed using Sojourner results; data from the FIDO rover, including trenches dug into sand, mud cracks, and weakly indurated bedrock; and experiments with MER testbed rovers. Particular attention will be focused on Mini-TES measurements designed to determine the abundance and state of subsurface water (e.g. hydrated, in zeolites, residual pore ice?) predicted to be present from Odyssey GRS/NS/HEND data.

Biomechanical effects of mobile computer location in a vehicle cab.

PubMed

Saginus, Kyle A; Marklin, Richard W; Seeley, Patricia; Simoneau, Guy G; Freier, Stephen

2011-10-01

The objective of this research is to determine the best location to place a conventional mobile computer supported by a commercially available mount in a light truck cab. U.S. and Canadian electric utility companies are in the process of integrating mobile computers into their fleet vehicle cabs. There are no publications on the effect of mobile computer location in a vehicle cab on biomechanical loading, performance, and subjective assessment. The authors tested four locations of mobile computers in a light truck cab in a laboratory study to determine how location affected muscle activity of the lower back and shoulders; joint angles of the shoulders, elbows, and wrist; user performance; and subjective assessment. A total of 22 participants were tested in this study. Placing the mobile computer closer to the steering wheel reduced low back and shoulder muscle activity. Joint angles of the shoulders, elbows, and wrists were also closer to neutral angle. Biomechanical modeling revealed substantially less spinal compression and trunk muscle force. In general, there were no practical differences in performance between the locations. Subjective assessment indicated that users preferred the mobile computer to be as close as possible to the steering wheel. Locating the mobile computer close to the steering wheel reduces risk of injuries, such as low back pain and shoulder tendonitis. Results from the study can guide electric utility companies in the installation of mobile computers into vehicle cabs. Results may also be generalized to other industries that use trucklike vehicles, such as construction.

Human machine interface to manually drive rhombic like vehicles such as transport casks in ITER

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lopes, Pedro; Vale, Alberto; Ventura, Rodrigo

2015-07-01

The Cask and Plug Remote Handling System (CPRHS) and the respective Cask Transfer System (CTS) are designed to transport activated components between the reactor and the hot cell buildings of ITER during maintenance operations. In nominal operation, the CPRHS/CTS shall operate autonomously under human supervision. However, in some unexpected situations, the automatic mode must be overridden and the vehicle must be remotely guided by a human operator due to the harsh conditions of the environment. The CPRHS/CTS is a rhombic-like vehicle with two independent steerable and drivable wheels along its longitudinal axis, giving it omni-directional capabilities. During manual guidance, themore » human operator has to deal with four degrees of freedom, namely the orientations and speeds of two wheels. This work proposes a Human Machine Interface (HMI) to manage the degrees of freedom and to remotely guide the CPRHS/CTS in ITER taking the most advantages of rhombic like capabilities. Previous work was done to drive each wheel independently, i.e., control the orientation and speed of each wheel independently. The results have shown that the proposed solution is inefficient. The attention of the human operator becomes focused in a single wheel. In addition, the proposed solution cannot assure that the commands accomplish the physical constrains of the vehicle, resulting in slippage or even in clashes. This work proposes a solution that consists in the control of the vehicle looking at the position of its center of mass and its heading in the world frame. The solution is implemented using a rotational disk to control the vehicle heading and a common analogue joystick to control the vector speed of the center of the mass of the vehicle. The number of degrees of freedom reduces to three, i.e., two angles (vehicle heading and the orientation of the vector speed) and a scalar (the magnitude of the speed vector). This is possible using a kinematic model based on the vehicle Instantaneous Center of Rotation (ICR): a geometric approach where, at each time instant, the vehicle describes a circumference (either with a finite or infinite radius). The inverse of the kinematic model transforms the three input parameters of the center of mass into the four parameters for the wheels, preserving the omni-directional capabilities. The solution is implemented and tested using a HMI with a control disk and an analog joystick with two axis. The control disk was specially designed for this solution and implemented using a programmable micro-controller. In the first set of experiments, the HMI communicates with a computer running a simulator of the CPRHS/CTS, with the vehicle kinematics and dynamics, moving in a map of the ITER buildings. In the second set of experiments, the HMI communicates with a scaled prototype of the CPRHS running in a mock-up scenario to obtain more realistic results. Several type of tests were performed to evaluate the usability of the HMI. Different human operators without knowledge neither experience with this interface were invited to test the HMI. The operators had to drive the vehicle from an initial place to a final destination under the following conditions: with a pre-computed path to help guidance, without any path, with the information of the closest obstacles and without any help. The performance was evaluated using the time duration of the operation, the energy required to perform the described path, the risk of collision and, in case of a pre-computed path, the comparison between paths. In addition, each operator tested the HMI several times to evaluate the performance along consecutive trials. (authors)« less

Design and testing of an innovative measurement device for tyre-road contact forces

NASA Astrophysics Data System (ADS)

Cheli, F.; Braghin, F.; Brusarosco, M.; Mancosu, F.; Sabbioni, E.

2011-08-01

The measurement of tyre-road contact forces is the first step towards the development of new control systems for improving vehicle safety and performances. Tyre-road contact forces measurement systems are very expensive and significantly modify the unsprung masses of the vehicle as well as the rotational inertia of the tyres. Thus, vehicle dynamics results are significantly affected. As a consequence, the measured contact forces do not correspond to the contact forces under real working conditions. A new low-cost tyre-road contact forces measurement system is proposed in this paper that can be applied to passenger cars. Its working principle is based on the measurement of three deformations of the wheel rim through strain gauges. The tyre-rim assembly is thus turned into a sensor for tyre-road contact forces. The influence of the strain gauges position onto the measurement results has been assessed through finite element simulations and experimental tests. It has been proven that, for a large variety of rims, the strain gauge position that leads to high signal-to-noise ratios is almost the same. A dynamic calibration procedure has been developed in order to allow the reconstruction of contact force and torque components once per wheel turn. The capability of the developed device to correctly estimate tyre-road contact forces has been assessed, in a first stage, through indoor laboratory experimental test on an MTS Flat-Trac ® testing machine. Results show that the implemented measuring system allows to reconstruct contact forces once per wheel turn with a precision that is comparable to that of existing high-cost measurement systems. Subsequently, outdoor tests with a vehicle having all four wheels equipped with the developed measuring device have also been performed. Reliability of the measurements provided by the developed sensor has been assessed by comparing the global measured longitudinal/lateral forces and the product of the measured longitudinal/lateral accelerations times the vehicle mass. A good agreement has been found during all the performed manoeuvres.

Strain features and condition assessment of orthotropic steel deck cable-supported bridges subjected to vehicle loads by using dense FBG strain sensors

NASA Astrophysics Data System (ADS)

Wei, Shiyin; Zhang, Zhaohui; Li, Shunlong; Li, Hui

2017-10-01

Strain is a direct indicator of structural safety. Therefore, strain sensors have been used in most structural health monitoring systems for bridges. However, until now, the investigation of strain response has been insufficient. This paper conducts a comprehensive study of the strain features of the U ribs and transverse diaphragm on an orthotropic steel deck and proposes a statistical paradigm for crack detection based on the features of vehicle-induced strain response by using the densely distributed optic fibre Bragg grating (FBG) strain sensors. The local feature of strain under vehicle load is highlighted, which enables the use of measurement data to determine the vehicle loading event and to make a decision regarding the health status of a girder near the strain sensors via technical elimination of the load information. Time-frequency analysis shows that the strain contains three features: the long-term trend item, the short-term trend item, and the instantaneous vehicle-induced item (IVII). The IVII is the wheel-induced strain with a remarkable local feature, and the measured wheel-induced strain is only influenced by the vehicle near the FBG sensor, while other vehicles slightly farther away have no effect on the wheel-induced strain. This causes the local strain series, among the FBG strain sensors in the same transverse locations of different cross-sections, to present similarities in shape to some extent and presents a time delay in successive order along the driving direction. Therefore, the strain series induced by an identical vehicle can be easily tracked and compared by extracting the amplitude and calculating the mutual ratio to eliminate vehicle loading information, leaving the girder information alone. The statistical paradigm for crack detection is finally proposed, and the detection accuracy is then validated by using dense FBG strain sensors on a long-span suspension bridge in China.

Propulsion and Levitation with a Large Electrodynamic Wheel

NASA Astrophysics Data System (ADS)

Gaul, Nathan; Lane, Hannah

We constructed an electrodynamic wheel using a motorized bicycle wheel with a radius of 12 inches and 36 one-inch cube magnets attached to the rim of the wheel. The radial magnetic field on the outside of the wheel was maximized by arranging the magnets into a series of Halbach arrays which amplify the field on one side of the array and reduce it on the other side. Rotating the wheel produces a rapidly oscillating magnetic field. When a conductive metal ``track'' is placed in this area of strong magnetic flux, eddy currents are produced in the track. These eddy currents create magnetic fields that interact with the magnetic fields from the electrodynamic wheel. The interaction of the magnetic fields produces lift and drag forces on the track which were measured with force gauges. Measurements were taken at a variety of wheel speeds, and the results were compared to the theoretical prediction that there should be a linear relationship between the lift and drag forces with increasing wheel speed. Partial levitation was achieved with the current electrodynamic wheel. In the future, the wheel will be upgraded to include 72 magnets rather than 36 magnets. This will double the frequency at which the magnetic field oscillates, increasing the magnetic flux. Electrodynamic wheels have applications to the transportation industry, since multiple electrodynamic wheels could be used on a vehicle to produce a lift and propulsion force over a conductive track.

Defeating the IED: JIEDDO’s Mission Impossible, the Lure of Technology, and the Emergence of the COIN Solution

DTIC Science & Technology

2011-04-12

8 Figure 4 : MaxxPro MRAP Vehicle ......................................................... 13...armored military vehicles , to demonstrate, often through the dissemination of video clips of attacks, the ability of overmatched irregular fighters to...34 vehicles , such as main battle tanks, were designed for. Additionally, the U.S. military is dependent on wheeled vehicles and roads for almost all combat

Microgrid and Plug in Electric Vehicle (PEV) with Vehicle to Grid (V2G) Power Services Capability (Briefing Charts)

DTIC Science & Technology

2015-09-01

unclassified Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 AGENDA 1. Non-Tactical Vehicle-to-Grid (V2G) Projects • Smart Power...Vehicle Technology Expo and the Battery Show Conference Novi, MI, 15-17 Sep 2015 2 For the Nation • Help stabilize smart grid and can generate revenue...demonstration of a smart , aggregated, ad-hoc capable, vehicle to grid (V2G) and Vehicle to Vehicle (V2V) capable fleet power system to support

A parametric study of golf car and personal transport vehicle braking stability and their deficiencies.

PubMed

Seluga, Kristopher J; Baker, Lowell L; Ojalvo, Irving U

2009-07-01

This paper describes research and parametric analyses of braking effectiveness and directional stability for golf cars, personal transport vehicles (PTVs) and low speed vehicles (LSVs). It is shown that current designs, which employ brakes on only the rear wheels, can lead to rollovers if the brakes are applied while traveling downhill. After summarizing the current state of existing safety standards and brake system designs, both of which appear deficient from a safety perspective, a previously developed dynamic simulation model is used to identify which parameters have the greatest influence on the vehicles' yaw stability. The simulation results are then used to parametrically quantify which combination of these factors can lead to yaw induced rollover during hard braking. Vehicle velocity, steering input, path slope and tire friction are all identified as important parameters in determining braking stability, the effects of which on rollover propensity are presented graphically. The results further show that when vehicles are equipped with front brakes or four-wheel brakes, the probability of a yaw induced rollover is almost entirely eliminated. Furthermore, the parametric charts provided may be used as an aid in developing guidelines for golf car and PTV path design if rear brake vehicles are used.

Proceedings of the European ISTVS Conference (6th), OVK Symposium (4th), on "Off Road Vehicles in Theory and Practice". Held at Vienna, Austria on 28-30 September 1994. Volume 2.

DTIC Science & Technology

1994-09-30

experimental proof-of-concept series hybrid thermo-mechano-elec- tromechanical and/or electromechanical All-Wheel-Driven (AWD) pro- pulsion, All-Wheel...caterpillar-tracks’ motorized sprocket-, road- and tensioner- wheels form a complete proof-of-concept series hybrid thermo- mechano-electromechanical and/or...tromechanical AWA supension spheres and skid-steering conversion spheres used as integral spheres together with future new concept hybrid thermo

Fully decentralized estimation and control for a modular wheeled mobile robot

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mutambara, A.G.O.; Durrant-Whyte, H.F.

2000-06-01

In this paper, the problem of fully decentralized data fusion and control for a modular wheeled mobile robot (WMR) is addressed. This is a vehicle system with nonlinear kinematics, distributed multiple sensors, and nonlinear sensor models. The problem is solved by applying fully decentralized estimation and control algorithms based on the extended information filter. This is achieved by deriving a modular, decentralized kinematic model by using plane motion kinematics to obtain the forward and inverse kinematics for a generalized simple wheeled vehicle. This model is then used in the decentralized estimation and control algorithms. WMR estimation and control is thusmore » obtained locally using reduced order models with reduced communication of information between nodes is carried out after every measurement (full rate communication), the estimates and control signals obtained at each node are equivalent to those obtained by a corresponding centralized system. Transputer architecture is used as the basis for hardware and software design as it supports the extensive communication and concurrency requirements that characterize modular and decentralized systems. The advantages of a modular WMR vehicle include scalability, application flexibility, low prototyping costs, and high reliability.« less

Wheelchair users' perceptions of and experiences with power assist wheels.

PubMed

Giacobbi, Peter R; Levy, Charles E; Dietrich, Frederick D; Winkler, Sandra Hubbard; Tillman, Mark D; Chow, John W

2010-03-01

To assess wheelchair users' perceptions of and experiences with power assist wheels using qualitative interview methods. Qualitative evaluations were conducted in a laboratory setting with a focus on users' experiences using power assist wheel in their naturalistic environments. Participants consisted of seven women and 13 men (M(age) = 42.75, SD = 14.68) that included one African American, one Hispanic, 17 whites, and one individual from Zambia. Qualitative interviews were conducted before, during, and after use of a power assist wheel. Main outcome measures included the wheelchair users' evaluations and experiences related to the use of power assist wheels. The primary evaluations included wheeling on challenging terrains, performance of novel activities, social/family aspects, fatigue, and pain. These descriptions indicated that most participants perceived positive experiences with the power assist wheels, including access to new and different activities. Secondary evaluations indicated that the unit was cumbersome and prohibitive for some participants because of difficulties with transport in and out of a vehicle and battery life. Most participants felt that power assist wheels provided more independence and social opportunities. The power assist wheel seems to offer physical and social benefits for most wheelers. Clinicians should consider users' home environment and overall life circumstances before prescribing.

75 FR 45089 - Rogue River-Siskiyou National Forest, Oregon; Motorized Vehicle Use on the Rogue River-Siskiyou...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-02

... Establishing and Designating a System of Roads, Trails and Areas for Wheeled Motorized Vehicles AGENCY: Forest... Management Rule requires designation of those roads, trails, and areas that are open to motor vehicle use by... completed an inventory of existing open roads and trails. Currently, there are approximately 4,620 road...

78 FR 65761 - General Motors, LLC, Receipt of Petition for Decision of Inconsequential Noncompliance

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-01

... vehicles does not fully comply with paragraph S9.1.1 of FMVSS No. 108, which requires an active turn signal to cancel when the steering wheel is rotated. On some of the vehicles, the turn signal may... The turn signal operating unit installed on passenger cars, multipurpose passenger vehicles, trucks...

The Proliferation of Unmanned Aerial Vehicles: Terrorist Use, Capability, and Strategic Implications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ball, Ryan Jokl

There has been unparalleled proliferation and technological advancement of consumer unmanned aerial vehicles (UAVs) across the globe in the past several years. As witnessed over the course of insurgency tactics, it is difficult to restrict terrorists from using widely available technology they perceive as advantageous to their overall strategy. Through a review of the characteristics, consumer market landscape, tactics, and countertactics, as well as operational use of consumer-grade UAVs, this open-source report seeks to provide an introductory understanding of the terrorist-UAV landscape, as well as insights into present and future capabilities. The caveat is evaluating a developing technology haphazardly usedmore » by terrorists in asymmetric conflicts.« less

Corrosion Control of Central Vehicle Wash Facility Pump Components Using Alternative Alloy Coatings

DTIC Science & Technology

2016-07-01

military installations are es- sential for supporting the readiness of tactical vehicles. Steel wash-rack pumps are vulnerable to accelerated...Management Command (IMCOM). The technical monitors were Daniel J. Dunmire (OUSD(AT&L)), Bernie Rodriguez (IMPW-FM), and Valerie D. Hines (DAIM-ODF...statement Large steel water pumps are used to pump water into the Central Vehicle Wash Facility (CVWF) for vehicle washing at Fort Polk, LA. The interior

Impact of overweight vehicles (with heavy axle loads) on bridge deck deterioration.

DOT National Transportation Integrated Search

2012-03-01

Bridge deck slabs develop compressive stresses from global flexural deformation and locally from high-level : wheel loads when it is subjected to overweight trucks. This study quantified the impact of overweight vehicles : with heavy axle loads on br...

76 FR 62356 - Certain New Pneumatic Off-the-Road Tires From the People's Republic of China: Preliminary Results...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-07

...-steer loaders are four-wheel drive vehicles with the left-side drive wheels independent of the right... exporter can demonstrate that it is sufficiently independent so as to be entitled to a separate rate.\\28... separate rate analysis is not necessary to determine whether it is independent from government control.\\29...

Saturn Apollo Program

NASA Image and Video Library

1970-03-20

Under the direction of Marshall Space Flight Center (MSFC), the Lunar Roving Vehicle (LRV) was designed to allow Apollo astronauts a greater range of mobility during lunar exploration missions. During the development process, LRV prototype wheels underwent soil tests in building 4481 at Marshall Space Flight Center (MSFC). Pictured from left to right are the wheels for: LRV, Bendix Corporation, Local Scientific Survey Module (LSSM), and Grumman Industries.

Intelligence and Electronic Warfare (IEW) System Fact Sheets

DTIC Science & Technology

1994-04-06

unattended ground sensor system that detects, classifies, and determines direction of movement of intruding personnel and vehicles . It uses remotely...fixed and moving target locations, speed and direction of movement, and classification of tracked/wheeled vehicles . The GSM is equipped with standard... Vehicle The Pointer is a Hand-Launched Unmanned Aerial Vehicle (HL-UAV) to be employed by battalion scouts for t"over-the-hillll reconnaissance and

Spring 2008 Industry Study. Land Combat Systems Industry

DTIC Science & Technology

2008-01-01

fabrication and deployment of wheeled and tracked vehicles with a focus on the increase production requirements consequent to the conflicts in Iraq...industry. The paper first looks at issues of globalization and of the increased demand for military vehicles during wartime. After a brief assessment of...tracked combat vehicles with UDLP’s expertise in light and medium-weight vehicles , was created to ensure the survival of these two remaining military

Smart Infrared Inspection System Field Operational Test Final Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Siekmann, Adam; Capps, Gary J; Franzese, Oscar

2011-06-01

The Smart InfraRed Inspection System (SIRIS) is a tool designed to assist inspectors in determining which vehicles passing through the SIRIS system are in need of further inspection by measuring the thermal data from the wheel components. As a vehicle enters the system, infrared cameras on the road measure temperatures of the brakes, tires, and wheel bearings on both wheel ends of commercial motor vehicles (CMVs) in motion. This thermal data is then presented to enforcement personal inside of the inspection station on a user friendly interface. Vehicles that are suspected to have a violation are automatically alerted to themore » enforcement staff. The main goal of the SIRIS field operational test (FOT) was to collect data to evaluate the performance of the prototype system and determine the viability of such a system being used for commercial motor vehicle enforcement. From March 2010 to September 2010, ORNL facilitated the SIRIS FOT at the Greene County Inspection Station (IS) in Greeneville, Tennessee. During the course of the FOT, 413 CMVs were given a North American Standard (NAS) Level-1 inspection. Of those 413 CMVs, 384 were subjected to a SIRIS screening. A total of 36 (9.38%) of the vehicles were flagged by SIRIS as having one or more thermal issues; with brakes issues making up 33 (91.67%) of those. Of the 36 vehicles flagged as having thermal issues, 31 (86.11%) were found to have a violation and 30 (83.33%) of those vehicles were placed out-of-service (OOS). Overall the enforcement personnel who have used SIRIS for screening purposes have had positive feedback on the potential of SIRIS. With improvements in detection algorithms and stability, the system will be beneficial to the CMV enforcement community and increase overall trooper productivity by accurately identifying a higher percentage of CMVs to be placed OOS with minimal error. No future evaluation of SIRIS has been deemed necessary and specifications for a production system will soon be drafted.« less

Energy analysis of electric vehicles using batteries or fuel cells through well-to-wheel driving cycle simulations

NASA Astrophysics Data System (ADS)

Campanari, Stefano; Manzolini, Giampaolo; Garcia de la Iglesia, Fernando

This work presents a study of the energy and environmental balances for electric vehicles using batteries or fuel cells, through the methodology of the well to wheel (WTW) analysis, applied to ECE-EUDC driving cycle simulations. Well to wheel balances are carried out considering different scenarios for the primary energy supply. The fuel cell electric vehicles (FCEV) are based on the polymer electrolyte membrane (PEM) technology, and it is discussed the possibility to feed the fuel cell with (i) hydrogen directly stored onboard and generated separately by water hydrolysis (using renewable energy sources) or by conversion processes using coal or natural gas as primary energy source (through gasification or reforming), (ii) hydrogen generated onboard with a fuel processor fed by natural gas, ethanol, methanol or gasoline. The battery electric vehicles (BEV) are based on Li-ion batteries charged with electricity generated by central power stations, either based on renewable energy, coal, natural gas or reflecting the average EU power generation feedstock. A further alternative is considered: the integration of a small battery to FCEV, exploiting a hybrid solution that allows recovering energy during decelerations and substantially improves the system energy efficiency. After a preliminary WTW analysis carried out under nominal operating conditions, the work discusses the simulation of the vehicles energy consumption when following standardized ECE-EUDC driving cycle. The analysis is carried out considering different hypothesis about the vehicle driving range, the maximum speed requirements and the possibility to sustain more aggressive driving cycles. The analysis shows interesting conclusions, with best results achieved by BEVs only for very limited driving range requirements, while the fuel cell solutions yield best performances for more extended driving ranges where the battery weight becomes too high. Results are finally compared to those of conventional internal combustion engine vehicles, showing the potential advantages of the different solutions considered in the paper and indicating the possibility to reach the target of zero-emission vehicles (ZEV).

Injury pattern in lethal motorbikes-pedestrian collisions, in the area of Barcelona, Spain.

PubMed

Rebollo-Soria, M Carmen; Arregui-Dalmases, Carlos; Sánchez-Molina, David; Velázquez-Ameijide, Juan; Galtés, Ignasi

2016-10-01

There are several studies about M1 type vehicle-pedestrian collision injury pattern, and based on them, there has been several changes in automobiles for pedestrian protection. However, the lack of sufficient studies about injury pattern in motorbikes-pedestrian collisions leads to a lack of optimization design of these vehicles. The objective of this research is to study the injury pattern of pedestrians involved in collisions with motorized two-wheeled vehicles. A retrospective descriptive study of pedestrian's deaths after collisions with motorcycles in an urban area, like Barcelona was performed. The cases were collected from the Forensic Pathology Service database of the Institute of Legal Medicine of Catalonia. The selected cases were categorized as pedestrian-motorcycle collision, between January 1st, 2005 and December 31st, 2014. Data were collected from the autopsy, medical, and police report. The collected information was then analyzed using Microsoft Excel statistical functions. Traumatic Brain Injury is the main cause of death in pedestrian hit by motorized two-wheeled vehicles (62.85%). The most frequent injury was the subarachnoid hemorrhage, in 71.4% of cases, followed by cerebral contusions and skull base fractures (65.7%). By contrast, pelvic fractures and tibia fractures only appeared in 28.6%. The study characterizes the injury pattern of pedestrians involved in a collision with motorized two-wheeled vehicles in an urban area, like Barcelona, which has been found to be different from other vehicle-pedestrian collisions, with a higher incidence of brain injuries and minor frequency of lower extremities fractures in pelvis, tibia and fibula. Copyright © 2016 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Saturn Apollo Program

NASA Image and Video Library

1971-01-01

The Lunar Roving Vehicle (LRV) was designed to transport astronauts and materials on the Moon. It was a collapsible open-space vehicle about 10 feet long with large mesh wheels, anterna, appendages, tool caddies, and cameras. Powered by two 36-volt batteries, it has four 1/4-hp drive motors, one for each wheel. The vehicle was designed to travel in forward or reverse, negotiate obstacles about 1 foot high, cross crevasses about 2 feet wide, and climb or descend moderate slopes. Its speed limit was about 9 miles (14 kilometers) per hour. An LRV was used on each of the last three Apollo missions (Apollo 15, Apollo 16, and Apollo 17) and permitted the crew to travel several miles from the Lunar Module. The LRV was designed, developed, and tested by the Marshall Space Flight Center, and built by the Boeing Plant in Kent, Washington.

Saturn Apollo Program

NASA Image and Video Library

1971-01-01

The Lunar Roving Vehicle (LRV) was designed to transport astronauts and materials on the Moon. It was a collapsible open-space vehicle about 10 feet long with large mesh wheels, anterna, appendages, tool caddies, and cameras. Powered by two 36-volt batteries, it has four 1/4-hp drive motors, one for each wheel. The vehicle was designed to travel in forward or reverse, negotiate obstacles about 1 foot high, cross crevasses about 2 feet wide, and climb or descend moderate slopes. Its speed limit was about 9 miles (14 kilometers) per hour. An LRV was used on each of the last three Apollo missions (Apollo 15, Apollo 16, and Apollo 17) and permitted the crews to travel several miles from the Lunar Module. The LRV was designed, developed, and tested by the Marshall Space Flight Center, and built by the Boeing Plant in Kent, Washington.