A practical compound control strategy for electro-hydraulic load simulator

As an electro-hydraulic load simulator (EHLS) is a typical passive force or torque control system, strong motion disturbance has been the key problem. This paper constructs mathematical model of EHLS system and analyzes theoretically the root cause of extraneous torque. A compound control strategy is proposed to improve the loading performance of EHLS. The motion compensation controller based on the extended state observer (ESO) decouples actuator´s motion disturbance. And active disturbance rejection control (ADRC) is designed to cope with nonlinearities and uncertainties of EHLS. Simulation is performed to prove the validity of this method in eliminating extraneous torque.