Active Disturbance Rejection Adaptive Command Filtered Control of Electrohydraulic Actuator

This paper proposed an active disturbance rejection adaptive command filtered control (CFC) scheme for tracking control of electrohydraulic actuator subjected to both parametric uncertainties and uncertain nonlinearities. The proposed controller is developed by combining extended observer technology and adaptive CFC backstepping method. The adaptive law is used to deal with parameter uncertainty; matching uncertainties and mismatching uncertainties are estimated by two extended state observers and compensated in a feedforward way. Parameter self-adaptation can greatly reduce parameter uncertainty and ease the estimation burden of the extended state observer. CFC technology is employed to deal with the inherently complex explosion problem of classic backstepping technology. Therefore, the design of the controller avoids high-gain feedback, reduces tracking errors, and decreases online calculation burden. The proposed controller can guarantee asymptotic stability and expected control performance. Comparative simulation results are acquired to verify the tracking performance of the proposed approach.