Acceleration Slip Regulation And Torque Distribution Coordination Control For Rear-Wheel Independent Driving Electric Vehicle

The wheels of distributed driving electric vehicle could be controlled independently and exactly. So the distributed driving electric vehicles have obvious vehicle dynamics advantages compared to traditional internal combustion engine vehicles and centralized driving electric vehicles, all kinds of advanced control strategy would apply to it. The research object of this paper is rear-wheel independent driving electric vehicle. Its acceleration slip regulation and torque distribution coordination control have been researched, which solves the problem of driving wheels excessive slip and lateral stability druing the drving process. In addition, the CarSim and MATLAB/Simulink co-simulation test platform is established, which is used to verify the control strategy. The real wheel independent driving electric vehicle experiment platform is also designed, which is ready for testing the control strategy. The main research work includes the following five parts:(1) The electric vehicle dynamic model is established using CarSim software, and the model is parameterized based on the real vehicle experiment platform. The parameters of Magic Formula tire model are identified using the menthod of genetic algorithm based on the test data of tire in pure rolling condition and pure cornering condition. The resistance model is proposed, then parameters of this model are computed based on the vehicle sliding experiments.(2) Mechanism of electric vehicle acceleration slip has been researched, the fuzzy PID acceleration slip regulation controller based on the optimal slip ratio using slip ratio control is designed. In order to further improve the precision of acceleration slip regulation controller, using the theory of fuzzy control, an acceleration slip regulation based on wheel angular acceleration and slip ratio is proposed.(3) In order to ensure the lateral stability of vehicle when it enters into acceleration slip regulation condition on high speed or cornering, the acceleraton slip regulation based on dynamic torque distribution is proposed. Bases on the acceleration slip regulation controller which is proposed above, the under layer torque distribution controller is designed. The controller allocates the driving torque between right and left wheel dynamically with vehicle stability as the goal.(4) The CarSim and MATLAB/Simulink co-simulation test platform is established. The vehicle model is built in CarSim software, driving torque of motor is added to driving wheels directly as the external input of CarSim. The model of motor and control strategy is built in Simulink. The co-simulation test is run to verify the effect of acceleration slip regulation controller in some different conditions.(5) The design of the vehicle experiment platform is illustrated, including the scheme of overall layout, power system and the vehicle controller. The overall framework of signal acquisition system was introduced in detail, and the design of software system including data acquisition module and storage module.