Study on fault-tolerant control of distributed drive electric vehicle based on motor fault diagnosis and torque distribution

Abstract

This paper presents a fault-tolerant control approach for distributed drive electric vehicle (DDEV) with motor fault diagnosis and torque distribution, whose purpose is to preserve vehicle stability under motor fault. A motion controller composed of sliding mode control (SMC) and PID is designed based on vehicle dynamics model. An observation model is established by unscented Kalman filter (UKF) to identify the degree of motor failure. A coordinated fault-tolerant control scheme based on torque optimal distribution and active front steering (AFS) is proposed. This scheme uses torque optimal distribution solved by quadratic programming to realize torque redistribution during motor faults, and applies front wheel steering to achieve coordinated fault-tolerant control when the motor torque is saturated. A co-simulation model including the vehicle and controller is implemented in CarSim and Simulink software. To verify the effectiveness of proposed control scheme, the simulations are performed in co-simulation environment under double lane change, straight line and other working conditions to evaluate the control approach. The results illustrate the vehicle stability in various driving scenarios during motor faults. Compared with the fuzzy PID-based stability control, the peak values of the sideslip angle and yaw rate of vehicle are reduced by 18.9% and 16.7%, respectively.