Research On Four In-Wheel Driven Electric Vehicle Control Strategy Under The Wheel Pressure Imbalance Conditions

The difference of tire vertical excitation applied by Road can lead to different wheel pressure imbalance, which is the cause of the vehicle instability.The motors of four in-wheel driven electric vehicle are installed in the wheel directly, which provide four-wheel drive. The vehicle motion of yaw can be controlled by direct yaw moment control. This paper research the control strategy applied to the four in-wheel driven electric vehicle with the wheel pressure imbalance. The main work for research:1、Studied the influence on vehicle’s kinematic characteristics in wheel pressure imbalance situation. According to the road excitation on the wheel load, the influence of working condition of the car can be divided into wheel pressure balance condition and wheel pressure imbalance conditions. The simulation model can be build by CarSim-Matlab/Simulink simulation platform. The vehicle dynamics of wheel pressure balance and wheel pressure imbalance can be analyzed by the simulation model.2、Studied the traditional vehicle body stability control algorithm structure and control principle. Study the theory of stability control and determine the control targets. Research and design the direct yaw moment control strategy based on the PID, including direct yawing moment formulation layer design and torque distribution layer design. The control strategy of tracking ability and the ability to resist disturbance can be analyzed by Using CarSim-Matlab/Simulink simulation platform.3、Designed a stability control strategy Based on the control theory of ADRC. The principle of each component(ADRC) is studied. Yaw rate error controller and side-slip Angle controller are designed based on the ADRC. The CarSim-Matlab/Simulink simulation platform is Set up based on the theory of the ADRC. The vehicle control strategy based on the ADRC control algorithm is analyzed.4、Designed and built the hardware based on dSPACE in loop real-time simulation test platform. The real-time simulation system based on dSPACE is studied in this paper. the control theory based on the ADRC control algorithm is analyzed by the real-time simulation platform.This paper make full use of the characteristic(four-wheel independent drive control) of the Four in-wheel driven electric vehicle, study the four in-wheel driven electric vehicle stability control strategy under the wheel pressure imbalance situation. The ADRC control theory is introduced to overcome the defects of traditional PID control strategy, which has positive significance for the development of four in-wheel driven electric vehicles.