Adaptive Dynamic Surface Funnel Control of Hydraulic Systems With Finite-Time Prescribed Tracking Performance
Zhangbao Xu, Zhenle Dong, Hao Shen, Jianyong Yao
Abstract
Hydraulic servo systems are generally affected by disturbances, parametric uncertainties, and unmodeled dynamics. In order to improve the tracking performance of hydraulic servo systems, a new adaptive output feedback funnel control method with uncertainty compensation is proposed based on dynamic surface technology, which avoids the differential explosion problem generated in backstepping control and keeps the tracking performance always within a predetermined range. The observers and adaptive control are fused together to compensate for system model uncertainties and estimate unknown states; Meanwhile, a new control error variable with finite-time performance function is used to constrain system performance. The closed-loop system using this controller has high accuracy and strong robustness. It has been proven that the estimation errors are bounded and the control error of the closed-loop system is kept within the bound of funnel function. Experiments were conducted to test the high-performance properties of the proposed algorithm. Note to Practitioners—Hydraulic servo systems have received increasing research attention in recent years because of their widespread range of applications. In this paper, the high transient performance and precise steady-state tracking control of hydraulic servo system are studied. We propose a new adaptive output feedback funnel control method with uncertainty compensation based on dynamic surface technology. the associated stability proof is then presented. Experiments are conducted to demonstrate the effectiveness of the approach. In future research, we will address the problem of high precision control of hydraulic manipulator.