Anti-Lock Braking Control of an Electromagnetic Brake-by-Wire System

Abstract

This paper presents a nonlinear sliding mode type controller for slip regulation in a braking event for an electromagnetic brake-by-wire system equipped automobile. The electromagnetic brake -by-wire system under consideration consists of a set of eddy current brakes attached to the automobile wheels. The anti-lock braking controller modifies the brake torque command generated by a supervisory controller which, in turn, is based on the driver’s command sensed via brake pedal sensors. The modified brake torque command is then generated by a closed loop actuator control algorithm to control the eddy current brake (ECB) system. It is shown in this paper that the proposed anti-lock braking control system is stable in the sense of Lyapunov. Experimental results are presented for a test vehicle equipped with an electromagnetic brake-by-wire system. Experimental results show that the proposed anti-lock brake control algorithm provides very good slip regulation in a braking event on low friction coefficient surfaces (wet Jennite) when compared with that of a non anti-lock braking event. Experimental results also indicate that the proposed anti-lock braking control system provided a very smooth stop for the vehicle.