Road surface recognition based slip rate and stability control of distributed drive electric vehicles under different conditions

Abstract

Distributed drive vehicles are prone to wheel slip during driving on low adhesion coefficient roads. Wheel slip will not only cause energy loss, but also the different driving states of the two sides of the wheels will lead to a sharp deterioration in vehicle stability, which will adversely affect the dynamics and safety of the vehicle. For the control characteristics of distributed drive vehicles, a slip rate controller is designed on the basis of slip rate estimation, and a stability control strategy adapted to straight and steering driving are proposed. Firstly, the road surface is identified based on the Burckhardt tire model, and the optimal slip rate of the current road surface is estimated. And the optimal wheel speed corresponding to the current vehicle speed is calculated. An active disturbance rejection controller (ADRC) is established, which controls the four-wheel speeds by adjusting the motor output torque and tracks the optimal wheel speed corresponding to the optimal slip rate. The sliding-mode controller is designed considering the stability requirements of the vehicle during high-speed steering. And the wheel output torque is optimally allocated based on the quadratic programing method. Finally, joint simulations and hardware-in-the-loop tests verify the effectiveness of the control strategy proposed in this paper.