Robust Control of Anti-Lock Brake System for an Electric Vehicle Equipped with an Axle Motor

As the main power source of the electric vehicle, the electric motor has outstanding characteristics including rapid response, accurate control and four-quadrant operation. Being introduced into the dynamic chassis control of electrified vehicles, the electric motor torque can be used not only for driving and regenerative braking during normal operating conditions, but also offers a great potential to improve the dynamic control performance of the anti-lock braking under emergency deceleration situations.

This paper presents a robust control algorithm for anti-lock braking of a front-wheel-drive electric vehicle equipped with an axle motor. The hydraulic and regenerative braking system of the electric vehicle is modeled as a LPV (linear parameter varying) system. The nonlinearities of the control system are considered as uncertain parameters of a linear fractional transformation. A static-state feedback control algorithm which is robust against the uncertainties is designed to achieve the maximum braking capability of the vehicle. To validate the control performance of the proposed algorithm, simulations are carried out. Based on the simulation results, the proposed anti-lock braking control algorithm can achieve the good robustness and control performance under different road adhesion coefficients, guaranteeing the brake stability of the electric vehicle.