ABSTRACT The vision for the future automotive chassis is to interconnect the lateral, longitudinal, and vertical dynamics by separately controlling driving, braking, steering, and damping of each individual wheel. A major advantage of all wheel drive electric vehicles with four in-wheel motors is the possibility to control the torque and speed at each wheel independently. This paper proposes a traction controller for such a vehicle. It estimates the road’s adhesion potential at each wheel and adjusts each motor voltage, such that the longitudinal slip is kept in an optimal range. For development and validation, a full vehicle model is designed in ADAMS/View software, in co-simulation with motor and control elements, modeled in MATLAB/Simulink . INTRODUCTION Recently, electric vehicles (EV) have attracted a great deal of interest as an elegant solution to environmental and energy concerns. Thanks to substantial improvements in electric motor and battery technologies, EVs now have driving performance and efficiency metrics that are comparable to those of internal combustion (IC) engine vehicles. EVs have no tailpipe emissions because they have no fuel, combustion, or exhaust systems. Further benefits of EVs include a reduction in noise pollution as well as the noise, vibration, and harshness (NVH) of the vehicle itself, due to the elimination of the engine and other powertrain components. In addition, EVs are the most exciting platforms on which to apply advanced motion control techniques, since not only the torque but also the motor speed can be generated and controlled quickly and precisely. The torque response of an electric motor is on the order of a few milliseconds and, therefore, 10 to 50 times faster than that of the IC engines and hydraulic braking systems in use today [1]. Hence, the most advanced traction control system can be implemented by controlling the electric motors’ torques to maintain the optimal traction of each tire. This applies in particular to vehicles with independently driven in-wheel motors, since the ratio of drive torque between the wheels can be adjusted quickly to meet the requirements of the current driving situation. As part of an ongoing Auto21 (a Canadian Network Center of Excellence) project, Collaborative Design Tools for Distributed, Multi-disciplinary Design Projects, an electric vehicle (AUTO21EV) is being designed. It is equipped with four direct drive in-wheel motors, an active steering system, and passive suspension systems on the front and rear axles (Figure 1). All Wheel Drive, In-Wheel Motors with Regenerative Braking Active Steering SystemPassive Double Wishbone Front Suspension Passive Multi-Link Rear Suspension Lithium-Ion Battery Packs Anti-Roll BarLight Weight Tube Chassis Structure All Wheel Drive, In-Wheel Motors with Regenerative Braking Active Steering SystemPassive Double Wishbone Front Suspension Passive Multi-Link Rear Suspension Lithium-Ion Battery Packs Anti-Roll BarLight Weight Tube Chassis Structure Figure 1: AUTO21EV concept Table 1 demonstrates the relevant vehicle parameters of the AUTO21EV used in the simulations. Based on this vehicle concept, a novel traction control system is introduced, which estimates the road’s adhesion potential at each tire and adjusts the motor voltage on each wheel to maintain the longitudinal slip within an ideal range. The performance of the controller has been verified based on a full vehicle model, using ADAMS/View and Pecejka tire models. Electric motors, as well as the control system elements, are modeled in a 2008-01-0589 Design of an Advanced Traction Controller for an Electric Vehicle Equipped with Four Direct Driven In-Wheel Motors Kiumars Jalali University of Waterloo Kai Bode Technical University of Braunschweig Steve Lambert and John McPhee University of Waterloo Copyright © 2008 SAE International SAE Int. J. Passeng. Cars - Electron. Electr. Syst. | Volume 1 | Issue 1 211Downloade