The Experts below are selected from a list of 2649 Experts worldwide ranked by ideXlab platform
Panos Y Papalambros - One of the best experts on this subject based on the ideXlab platform.
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a market systems analysis of the u s Sport Utility Vehicle market considering frontal crash safety technology and policy
Accident Analysis & Prevention, 2013Co-Authors: Steven Hoffenson, Bart D Frischknecht, Panos Y PapalambrosAbstract:Active safety features and adjustments to the New Car Assessment Program (NCAP) consumer-information crash tests have the potential to decrease the number of serious traffic injuries each year, according to previous studies. However, literature suggests that risk reductions, particularly in the automotive market, are often accompanied by adjusted consumer risk tolerance, and so these potential safety benefits may not be fully realized due to changes in consumer purchasing or driving behavior. This article approaches safety in the new Vehicle market, particularly in the Sport Utility Vehicle and Crossover Utility Vehicle segments, from a market systems perspective. Crash statistics and simulations are used to predict the effects of design and policy changes on occupant crash safety, and discrete choice experiments are conducted to estimate the values consumers place on Vehicle attributes. These models are combined in a market simulation that forecasts how consumers respond to the available Vehicle alternatives, resulting in predictions of the market share of each Vehicle and how the change in fleet mixture influences societal outcomes including injuries, fuel consumption, and firm profits. The model is tested for a scenario where active safety features are implemented across the new Vehicle fleet and a scenario where the U.S. frontal NCAP test speed is modified. While results exhibit evidence of consumer risk adjustment, they support adding active safety features and lowering the NCAP frontal test speed, as these changes are predicted to improve the welfare of both firms and society.
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a market systems analysis of the u s Sport Utility Vehicle market considering frontal crash safety technology and policy
DS 71: Proceedings of NordDesign 2012 the 9th NordDesign conference Aarlborg University Denmark. 22-24.08.2012, 2012Co-Authors: Steven Hoffenson, Bart D Frischknecht, Panos Y PapalambrosAbstract:Active safety features and adjustments to the New Car Assessment Program (NCAP) consumer-information crash tests have the potential to decrease the number of serious injuries on United States (U.S.) roadways each year, according to previous studies. However, literature suggests that risk reductions, particularly in the automotive market, are often accompanied by adjusted consumer risk tolerance, and so these potential safety benefits may not be fully realized due to changes in consumer purchasing or driving behaviour. This article approaches safety in the new Vehicle market, particularly in the Sport Utility Vehicle and Crossover Utility Vehicle segments, from a market systems perspective. Crash statistics and simulations are used to predict the effects of design and policy changes on occupant crash safety, and discrete choice experiments are conducted to estimate the values consumers place on Vehicle attributes. These models are combined in a market simulation to forecast how consumers respond to available Vehicle alternatives. The model is tested for a scenario where active safety features are implemented across the new Vehicle fleet and a scenario where the U.S. frontal NCAP test speed is modified. Results exhibit evidence of consumer risk adjustment and support adding active safety features and lowering the NCAP frontal test speed, as these changes are predicted to improve the welfare of both firms and society.
Rajesh Rajamani - One of the best experts on this subject based on the ideXlab platform.
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real time automotive slip angle estimation with extended h circle criterion observer for nonlinear output system
Advances in Computing and Communications, 2017Co-Authors: Gridsada Phanomchoeng, Ali Zemouche, Rajesh RajamaniAbstract:Many active Vehicle safety systems such as electronic stability control (ESC), rollover prevention, and lane departure avoidance could benefit from knowledge of the Vehicle slip angle. However, it is a challenge to design an observer to estimate slip angle reliably under a wide range of Vehicle maneuvers and operating conditions. This is due especially to nonlinear tire characteristics and system models which have nonlinear output equations. Hence this paper develops an extended H ∞ circle criterion observer for state estimation in systems with nonlinear output equations. The observer design approach utilizes a modified Young's relation to include additional degrees of freedom in the linear matrix inequality (LMI) used for observer gain design. This enhanced LMI is less conservative than others proposed in the literature for Lipschitz nonlinear systems, both with and without nonlinear output equations. The observer is applied to slip angle estimation and utilizes inexpensive sensors available in all modern Vehicles. Finally, experimental tests on a Volvo XC90 Sport Utility Vehicle are used to evaluate the developed approach. The experimental results show that the slip angle estimates for a variety of test maneuvers on road surfaces with different friction coefficients are reliable.
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Real-time automotive slip angle estimation with extended $H_\infty$ circle criterion observer for nonlinear output system
2017Co-Authors: Gridsada Phanomchoeng, Ali Zemouche, Rajesh RajamaniAbstract:Many active Vehicle safety systems such as electronic stability control (ESC), rollover prevention, and lane departure avoidance could benefit from knowledge of the Vehicle slip angle. However, it is a challenge to design an observer to estimate slip angle reliably under a wide range of Vehicle maneuvers and operating conditions. This is due especially to nonlinear tire characteristics and system models which have nonlinear output equations. Hence this paper develops an extended H_∞ circle criterion observer for state estimation in systems with nonlinear output equations. The observer design approach utilizes a modified Young’s relation to include additional degrees of freedom in the linear matrix inequality (LMI) used for observer gain design. This enhanced LMI is less conservative than others proposed in the literature for Lipschitz nonlinear systems, both with and without nonlinear output equations. The observer is applied to slip angle estimation and utilizes inexpensive sensors available in all modern Vehicles. Finally, experimental tests on a Volvo XC90 Sport Utility Vehicle are used to evaluate the developed approach. The experimental results show that the slip angle estimates for a variety of test maneuvers on road surfaces with different friction coefficients are reliable.
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algorithms for real time estimation of individual wheel tire road friction coefficients
IEEE-ASME Transactions on Mechatronics, 2012Co-Authors: Rajesh Rajamani, Gridsada Phanomchoeng, Damrongrit PiyabongkarnAbstract:It is well recognized in the automotive research community that knowledge of the real-time tire-road friction coefficient can be extremely valuable for active safety applications, including traction control, yaw stability control and rollover prevention. Previous research results in literature have focused on the estimation of average tire-road friction coefficient for the entire Vehicle. This paper explores the development of algorithms for reliable estimation of independent friction coefficients at each individual wheel of the Vehicle. Three different observers are developed for the estimation of slip ratios and longitudinal tire forces, based on the types of sensors available. After estimation of slip ratio and tire force, the friction coefficient is identified using a recursive least-squares parameter identification formulation. The observers include one that utilizes engine torque, brake torque, and GPS measurements, one that utilizes torque measurements and an accelerometer and one that utilizes GPS measurements and an accelerometer. The developed algorithms are first evaluated in simulation and then evaluated experimentally on a Volvo XC90 Sport Utility Vehicle. Experimental results demonstrate the feasibility of estimating friction coefficients at the individual wheels reliably and quickly. The sensitivities of the observers to changes in Vehicle parameters are evaluated and comparisons of robustness of the observers are provided.
Damrongrit Piyabongkarn - One of the best experts on this subject based on the ideXlab platform.
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algorithms for real time estimation of individual wheel tire road friction coefficients
IEEE-ASME Transactions on Mechatronics, 2012Co-Authors: Rajesh Rajamani, Gridsada Phanomchoeng, Damrongrit PiyabongkarnAbstract:It is well recognized in the automotive research community that knowledge of the real-time tire-road friction coefficient can be extremely valuable for active safety applications, including traction control, yaw stability control and rollover prevention. Previous research results in literature have focused on the estimation of average tire-road friction coefficient for the entire Vehicle. This paper explores the development of algorithms for reliable estimation of independent friction coefficients at each individual wheel of the Vehicle. Three different observers are developed for the estimation of slip ratios and longitudinal tire forces, based on the types of sensors available. After estimation of slip ratio and tire force, the friction coefficient is identified using a recursive least-squares parameter identification formulation. The observers include one that utilizes engine torque, brake torque, and GPS measurements, one that utilizes torque measurements and an accelerometer and one that utilizes GPS measurements and an accelerometer. The developed algorithms are first evaluated in simulation and then evaluated experimentally on a Volvo XC90 Sport Utility Vehicle. Experimental results demonstrate the feasibility of estimating friction coefficients at the individual wheels reliably and quickly. The sensitivities of the observers to changes in Vehicle parameters are evaluated and comparisons of robustness of the observers are provided.
Thorsten Benter - One of the best experts on this subject based on the ideXlab platform.
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investigation on the potential generation of ultrafine particles from the tire road interface
Atmospheric Environment, 2011Co-Authors: Marcel Mathissen, Volker Scheer, Rainer Vogt, Thorsten BenterAbstract:Abstract There has been some discussion in the literature on the generation of ultrafine particles from tire abrasion of studded and non-studded tires tested in the laboratory environment. In the present study, the potential generation of ultrafine particles from the tire road interface was investigated during real driving. An instrumented Sport Utility Vehicle equipped with summer tires was used to measure particle concentrations with high temporal resolution inside the wheel housing while driving on a regular asphalt road. Different driving conditions, i.e., straight driving, acceleration, braking, and cornering were applied. For normal driving conditions no enhanced particle number concentration in the size range 6–562 nm was found. Unusual maneuvers associated with significant tire slip resulted in measurable particle concentrations. The maximum of the size distribution was between 30 and 60 nm. An exponential increase of the particle concentration with velocity was measured directly at the disc brakes for full stop brakings. A tracer gas experiment was carried out to estimate the upper limit of the emission factor during normal straight driving.
John R Spletzer - One of the best experts on this subject based on the ideXlab platform.
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ATRS - A Technology-based Solution to Automobility for Wheelchair Users
2007Co-Authors: C. Gao, I. Hoffman, T. Panzarella, John R SpletzerAbstract:In this paper, we present the Automated TranSport and Retrieval System (ATRS). ATRS represents an alternative to van conversions for automobile drivers with lower body disabilities. It employs robotics and automation technologies that integrate into a standard minivan or Sport Utility Vehicle (SUV). At the core of ATRS is a “smart” wheelchair that navigates between the driver's position and a powered lift at the rear of the Vehicle - eliminating the need for an attendant. From an automation perspective, autonomously docking the wheelchair onto the lift platform presented the most significant technical challenge during system development. This was driven by geometry constraints, which limited clearance between the chair wheels and the lift platform rails. To solve this problem, we employed an LMS291 LIDAR in conjunction with an Extended Kalman Filter for reliable and accurate wheelchair localization. Coupled with a hybrid controller design, the system has proven to be exceptionally robust. This was validated through extensive simulation and experimental results, culminating in a three-day demonstration at the 2006 World Congress and Exposition on Disabilities where the system completed over 300 consecutive cycles without a failure.
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vision based control of a smart wheelchair for the automated tranSport and retrieval system atrs
International Conference on Robotics and Automation, 2006Co-Authors: H Sermenovillalta, John R SpletzerAbstract:In this paper, we present a vision-based control approach for autonomously docking a wheelchair onto a Vehicle lift platform. This is a principle component of the automated tranSport and retrieval system (ATRS) - an alternate mobility solution for drivers with lower body disabilities. The ATRS employs robotics, automation, and machine vision technologies, and can be integrated into a standard minivan or Sport Utility Vehicle (SUV). At the core of the ATRS is a "smart" wheelchair system that autonomously navigates between the driver's position and a powered lift at the rear of the Vehicle eliminating the need for an attendant. From an automation perspective, autonomously docking the wheelchair onto the lift platform presented the most significant technical challenge for the proof-of-concept ATRS. This was driven primarily by geometry constraints, which limited clearance between the chair wheels and the lift platform rails. We present significant simulation and experimental results for our approach. These indicate that the coupling of vision-based localization for feedback and input/output feedback linearization techniques for controller design can provide for accurate wheelchair navigation and reliable docking under a range of ambient illumination conditions
