High dynamic feedback linearization control of hydraulic actuators with backstepping

Abstract

This article concerns the high dynamic tracking control of hydraulic servo systems. Unlike previous works usually dealing with high-accuracy tracking control, the proposed feedback linearization controller in this article guarantees excellent tracking performance even with high-frequency tracking demand. To handle unmatched disturbances in hydraulic systems, backstepping method is synthesized in the proposed controller. Typically, in the hydraulic systems, there also exist direct-current unmodeled disturbances which may lead to steady-state errors. An integral-like feedback term is added in the controller to cancel this unexpected effect. The stability of the closed-loop system is guaranteed via frequency-domain analysis. Three controllers, that is, the proportional–integral controller, the proportional–integral controller with velocity feed-forward scheme and the proposed feedback linearization controller, are compared. Extensive comparative experimental results demonstrate the high dynamic tracking performance of the proposed control strategy.