Model-Assisted Active Disturbance Rejection Control for Electro-Hydraulic Position Servo System With Mismatched Disturbances and Measurement Noise

This paper presents a model-assisted active disturbance rejection controller (MLADRC) to handle the control problem for the electro-hydraulic position servo (EHPS) system with mismatched disturbances and measurement noise. To solve the mismatched disturbances, the equivalent chain integral structure model is established, and the total disturbance in the system is revealed. Then a model-assisted linear extended state observer (MLESO), which has low bandwidth and noise sensitivity characteristics, is developed by introducing the model information. The stability of the MLESO is proved based on the Lyapunov stability theory. Moreover, a general industrial low-pass filter is employed to suppress the measurement noise further. Comparative simulation results show the superiority and practicability of the proposed control approach.