High precision composite control of electro-hydrostatic actuator based on extended state observer–model predictive control strategy

Electro-hydrostatic actuator (EHA) serve as crucial effectors in more-electric and all-electric aircraft, where high-precision displacement control is essential for system stability and flight safety. However, the dynamic characteristics of EHA exhibit pronounced nonlinearities, unmodeled dynamics, and susceptibility to external disturbances, which limit the effectiveness of traditional control approaches. To address these challenges, this study proposes a composite control strategy that integrates model predictive control (MPC) with an extended state observer (ESO). The ESO estimates unmodeled dynamics and external disturbances in real time, and the estimated total disturbance is fed forward into the MPC loop for active compensation. This integration enhances both robustness and transient performance. The proposed method is verified using a co-simulation platform. The results show that, compared with PID, MPC, and ESO–ADRC, the settling time of ESO–MPC under step input is reduced by 87.78%, 68.57%, and 59.26%, respectively, while the phase lag under sinusoidal input is reduced by 87.55%, 50.43%, and 32.94%, respectively. The disturbance estimation results show that the ESO can effectively reconstruct both composite sinusoidal and step-varying disturbances. The co-simulation results verify the effectiveness of ESO–MPC in high-precision EHA position control and provide a reference for controller design under complex operating conditions.