Active disturbance rejection control for hydraulic systems with full‐state constraints and input saturation

Abstract

Abstract Input saturation and disturbances often exist in hydraulic systems, reducing internal state stability and tracking response performances of the system as well as complicating the design of advanced non‐linear controllers. A practical method named active disturbance rejection controller is proposed by backstepping method for full‐state constrained hydraulic systems to constrain tracking errors in the desired boundaries and deal with input saturation as well as disturbances. To achieve the previously mentioned objectives, the disturbance compensation strategy and dynamic auxiliary systems are integrated into the barrier Lyapunov theory for the first time. It is proved that all states of hydraulic systems are kept within the ultimate boundaries with satisfactory dynamic performance and high steady‐state accuracy. In addition, when disturbances are constants, asymptotic tracking is theoretically achieved. The performance of the control strategy is verified by experimental results.