Control of wheel slip ratio using sliding mode controller with pulse widthmodulation

For the control of anti-lock brake system (ABS), a longitudinal four-wheel vehicle model with brake actuator is described and a sliding mode controlle r with pulse width modulation (PWM) method has been developed for passenger vehicles. In our research, we introduce actuator dynamics of solenoid-sole noid valve type in system equation and derive the sliding mode control inpu t theoretically. We propose using PWM method to compensate for the discrete nature of actuator dynamics by duty control. The effectiveness of the prop osed control algorithms was confirmed by vehicle test on an in-door test be nch that was specially constructed for the purpose concerned.