Control and Estimation of In-Wheel Motor Electric Vehicles: Utilizing the Actuation Redundancy

Electric ground vehicle (EGV) with four independently-actuated in-wheel motors has been considered as one of the promising future vehicle architectures. Besides the energetic and environmental advantages offered by the electric propulsion systems, the actuation flexibility and redundancy furnished by the independently-actuated in-wheel motors also provide new opportunities for further elevating EGV operating energy efficiency and safety. This talk presents some recent research results on the estimation and control of in-wheel motor EGVs emphasizing the utilization of actuation redundancy. Tire-road friction coefficient (TRFC) is a critically important parameter for vehicle control but cannot be measured onboard. By employing the in-wheel motor actuation redundancy, it is possible to reliably estimate the TRFC with no interference on the EGV longitudinal motion. The ways of using redundant actuators can influence the EGV operating efficiency. An energy-efficient control allocation method is developed to distribute the total control efforts among the available in-wheel motors with explicit considerations of the actuator efficiencies and operating modes. With the increased number of actuators on in-wheel motor EGVs, the probability of actuator faults also rises. Active fault diagnosis and fault-tolerant control approaches for in-wheel motor EGVs will be discussed. Simulation and experimental results demonstrate the effectiveness of the actuation-redundancy-based EGV estimation and control methods.

: Junmin Wang received the B.E. degree in Automotive Engineering and M.S. degree in Power Machinery and Engineering from the Tsinghua University, Beijing, China in 1997 and 2000, respectively, the M.S. degrees in both Electrical Engineering and Mechanical Engineering from the University of Minnesota, Twin Cities in 2003, and the Ph.D. degree in Mechanical Engineering from the University of Texas at Austin in 2007. He has five years of full-time industrial research experience (May 2003–August 2008) with the Southwest Research Institute, San Antonio, TX. Since September 2008, he has been an Assistant Professor with the Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus. His research interests include control, modeling, estimation, and diagnosis for engine, powertrain, after-treatment, ground vehicles, sustainable mobility, and mechatronic systems. He serves as an Associate Editor for the IEEE Transactions on Vehicular Technology and the ASME Dynamic Systems and Control Division Conference Editorial Board. He is an author or co-author of over 90 peer-reviewed papers in journals and conference proceedings and holds 10 U.S. patents. He received the Office of Naval Research Young Investigator Program (ONR-YIP) Award and the Oak Ridge Associate Universities Ralph E. Powe Junior Faculty Enhancement Award in 2009. He is one of the recipients of the 2009 SAE International Vincent Bendix Automotive Electronics Engineering Award.