ABS and active suspension control via high order sliding modes and linear geometric methods for disturbance rejection

In this work, high order sliding mode techniques are used to control an Anti-lock Brake System (ABS) which is assisted with an active suspension. The main objective is to modify the slip rate of a vehicle and ensure a shorter stopping distance in the braking process. The control system is designed in independent way for the ABS and the suspension subsystem. For the ABS subsystem a second order sliding mode controller is used. On the other hand, for the active suspension subsystem the supertwisting algorithm combined with regular form and linear geometric techniques is proposed. The use of sliding mode controllers allows that both closed-loop subsystems are robust against a class of external perturbations and system uncertainties, furthermore the chattering effect is reduced and higher tracking accuracy is obtained. The effectiveness of the proposed control strategy is confirmed via simulations.