Anti-skid control for EV using dynamic model error based on back-EMF observer

In this paper, a novel anti-skid controller for EV without speed sensor is proposed to prevent the slip between tire and road. Based on back-EMF observer and dynamic model error observer, an anti-skid controller with PI regulator is designed and analyzed. When skid occurs, the equivalent inertia of the EV system changes, and the acceleration of the wheels also changes. A back EMF observer is constructed to acquire the information of speed as well as the acceleration. Then a dynamic model error observer is setup using the signal of back EMF to regulate the torque (current) command, and keep the status of EV within a safe area. By selecting the gains of proportional item and integral item of the regulator, the torque (current) reduction can be adjusted freely in some range, and it is proved that the controller with integral item has better performance in skid restraining. The experimental results of the vehicle simulator utilizing motor-generator system verified the effectiveness of our proposed method.