A robust simplified backstepping control approach for pump-controlled electro-hydraulic systems

Abstract

Researches for improving both the control performance and energy efficiency of electro-hydraulic systems in industrial applications have been increasing in recent decades. Existence of nonlinearities, uncertainties, and unknown terms in the system dynamics are however the main obstacles to obtain the excellent performance. To contribute a high-accuracy tracking control by dealing with these problems, this paper proposes an advanced position controller for a pump-controlled electro-hydraulic system. Here, the nonlinearities are treated by a simplified backstepping technique while the unknown terms, including external disturbances and deviations of uncertainties, are covered by a robust law. An asymptotic tracking performance of the closed-loop system in the presence of bounded disturbances is then successfully validated by theoretical proof and extensive experiments.