Anti-lock regenerative braking torque control strategy for electric vehicle

Abstract

Regenerative braking is one of the most effective deceleration control methods in case of electric and hybrid vehicles. The properly controlled regenerative braking force of the electric motor(s) brings better braking safety, shorter braking distance, and less depreciation of the brakes if accompanied by the hydraulic braking modules. When the brake pedal is pressed, the electric motor is treated as a generator to produce negative torque. In this scenario the produced energy can be either dissipated or used to charge the batteries. In this paper, based on the registered brake strength, the braking force is calculated. Accordingly, employing a braking torque distribution strategy between the regenerative braking torque and the hydraulic braking torque, the proper braking torques are determined and the optimal slip ratio is reached by adjusting the braking torques. An anti-lock regenerative braking strategy is proposed to attain anti-slip control for negative accelerations. The performance of the proposed system is evaluated using simulations. The attained simulation results show that optimal braking characteristics are achievable for a variety of conditions using the proposed method.