Wheel Slip Control for ABS with Time Delay Input using Feedback Linearization and Adaptive Sliding Mode Control

The anti-lock braking system is an important subsystem in the brake system. Using the quarter car model, we derive the dynamic system model considering the time delay on the brake torque input. A nonlinear controller with full state feedback is proposed to maintain the wheel slip ratio at the desired slip ratio. Since, in practice, we cannot measure all the state variables, we introduce an output feedback controller utilizing the nonlinear sliding observer. The nonlinear controller with the sliding observer exhibits better performance compared with the conventional controller considering no time delay input.