Eliminate the surplus torque of electro-hydraulic load simulator using the actuator command dynamic compensation control

Electro-hydraulic load simulator (EHLS) is a typical closed-loop torque control system. It is used to simulate the load of aircraft actuator on ground hardware-in-the-loop simulation. In general, the movement of the actuator has interference torque for the EHLS named the surplus torque. The surplus torque is not only related to the velocity of the actuator movement, but also related to the frequency of actuator movement. Especially when the models of the actuator and the EHLS are dissimilar, the surplus torque is obviously different in the different frequencies. In order to eliminate the surplus torque for accurate load simulation, the actuator command dynamic compensation control (ACDC) is proposed in this paper. Under the condition of the velocity synchronization signal cannot be provided by the actuator control system, the actuator command is used for compensation of different frequency actuator movement to eliminate the surplus torque on different frequencies in this strategy. Firstly, the mathematical models of EHLS and the actuator system are established in detail, then the ACDC method is proposed. For verification, the simulations are conducted to prove that the new strategy performs well against low, medium and high frequency movement interference. The results show that this strategy can effectively eliminate the surplus torque in different frequencies actuator movement.