Hybrid Feedback Linearization Slip Control for Anti-lock Braking System

The Anti-lock braking system (ABS) is an active safety device in road vehicles, which during hard braking maximizes the braking force between the tyre and the road irrespective of the road conditions. This is accomplished by regulating the wheel slip around its optimum value. Due to the high non-linearity of the tyre and road interaction, and uncertainties from vehicle dynamics, a standard PID controller will not suffice. This paper therefore proposes a non-linear control design using input-output feedback linearization approach. To enhance the robustness of the non-linear controller, an integral feedback method was employed. The stability of the controller is analysed in the Lyapunov sense. To demonstrate the robustness of the proposed controller, simulations were conducted on two different road conditions. The results from the proposed method exhibited a more superior performance and reduced the chattering effect on the braking torque compared to the performance of the standard feedback linearization method.