A Design Approach for Observer-based Robust Traction Control with PMSM

Slip-ratio control of EV is one of the fundamental traction control problems especially for the unknown road condition. In order to regulate the slip-ratio around a constant value, a robust nonlinear control law at the torque level is proposed in this paper. In this control scheme, a nonlinear observation algorithm is designed to estimate the car velocity by using the wheel speed information. And an adaptive method is introduced to approximate the nonlinear friction parameters. Then, by means of the backstepping technology, a new torque control strategy for PMSM with vector transformation is presented to achieve the desired torque for the robust traction. The simulation results shows that the goal of traction control is achieved