Lateral stability and energy-saving integrated control of distributed drive vehicles with four wheel hub motors

Abstract: In order to improve the lateral stability and energy optimization of four-wheel hub motor distributed drive vehicles under complex road conditions, a layered control strategy for yaw stability is proposed. The upper controller is designed based on the sliding mode control principle to create a yaw moment controller, establishing both a two-degree-of-freedom model and a seven-degree-of-freedom model for the vehicle, tracking the desired yaw rate, desired center of mass side slip angle, actual yaw rate, and actual center of mass side slip angle to obtain the corresponding additional yaw moment. Moreover, the state of the vehicle is analyzed using the phase plane method of the center of mass side slip angle and yaw rate, and the total additional yaw moment for the vehicle is computed based on weighted calculations according to the state. Additionally, an unscented Kalman filter observer is established to enhance the tracking accuracy of the actual yaw rate and actual center of mass side slip angle in the seven-degree-of-freedom model. The lower controller uses vehicle torque distribution as the design variable, with tire load rate, torque variation rate, and motor energy consumption optimization as the multi-objective optimization target function to allocate torque to each hub motor. Finally, a combined vehicle simulation model is established using CarSim and Simulink, and simulation analyses are performed under double lane change and angular step response conditions to evaluate the lateral stability and energy consumption of the vehicle. The results indicate that the proposed layered control strategy for four-wheel hub motor distributed drive vehicles exhibits good lateral stability and satisfactory energy-saving effects. Keywords: Four-wheel hub motor distributed drive vehicles, lateral stability, sliding mode control, multi-objective optimization, energy optimization .