Sliding mode control of a hydraulic servo system position using adaptive sliding surface and adaptive gain

In this paper, we propose a method to control the position of an electrohydraulic system rod. Our approach consists of using the sliding mode theory. First, we construct an integral sliding mode controller to obtain robustness against constant perturbation. Next, to simplify the controller expression we design an adaptive integral sliding surface. To diminish the unwanted chattering phenomenon due to high gain, we design an adaptive sliding controller that adaptively estimates the sliding gain which ensures sliding mode and will decrease as stability is achieved to decrease the chattering amplitude. All the proposed method's results are illustrated by numerical simulations.