Synchronizing compensation control of electro-hydraulic load simulator using command signal of actuator

Electro-hydraulic load simulator is a typical case of the force (torque) servo system which is strongly coupled with a hydraulic position system. How to eliminate the extraneous torque from motion disturbances is the key difficulty in electro-hydraulic load simulators. Based on theoretical analysis of traditional synchronizing compensation controllers, the improved synchronizing compensation algorithm was put forward. This algorithm can make full use of actuator's velocity command signal and load simulator's torque feedback signal, which does not need actuator's velocity signal, acceleration signal and servo-valve current signal. Due to utilizing load simulator's torque feedback signal, it can effectively eliminate the extraneous torque and achieve a more accurate synchronizing compensation than traditional velocity synchronizing controller in big gradient loading conditions. The comparison results based on simulations and experiments show that this algorithm is more effective to eliminate extraneous torque from motion disturbances and improve the dynamic torque tracking accuracy in various typical operating conditions.