Extremum-seeking control strategy for ABS system with time delay

In this paper, an improved extremum-seeking control is developed via sliding mode to apply to systems with time delay and to avoid the problem of excessive oscillation. With such a control strategy, systems are kept working near the peak value of their performance index without priori knowledge of the performance index function. Stability for such controller design is investigated. The proposed method is applied to a pneumatic Anti-lock brake system (ABS) example to achieve better braking performance and avoid the lock-up phenomenon.