Incomplete differentiation-based improved adaptive backstepping integral sliding mode control for position control of hydraulic system

Abstract

In the hydraulic systems, the non-structural uncertainties such as the nonlinear friction will reduce the tracking accuracy for the hydraulic servo system. In this paper, an incomplete differential-based improved adaptive backstepping integral sliding mode control (ID-BIABISMC) is proposed to realize the position control for the hydraulic servo system based on the friction compensation. The backstepping-based control being integrated the integral sliding mode surface-based sliding mode control with the friction compensation are used to solve the problem of non-structural uncertainty of the hydraulic system. The incomplete differential is introduced to the adaptive update law, by which the low-pass filtering behavior in the incomplete differential is capable of effectively suppressing the interference caused by the pure differential mutation signal. Compared with the traditional adaptive backstepping control (ABC), adaptive sliding mode control (ASMC), the adaptive backstepping sliding mode control (ABSMC) and the proposed adaptive backstepping integral sliding mode control (IABISMC), the experimental results verify the high accuracy tracking performance of the proposed the incomplete differential-based improved adaptive backstepping integral sliding mode control (ID-BIABISMC). For the responses of the sinusoidal signal 40sin(0.2πt+1.5π)+40mm and step signal with 30 mm, the corresponding tracking accuracy for ID-BIABISMC are 0.005 mm and 2.15 mm, respectively.

Keywords: Backstepping integral sliding mode control; Friction compensation; Hydraulic servo systems; Incomplete differential.