An experimental study of the dual-loop control of electro-hydraulic load simulator (EHLS)

This paper investigates motion coupling disturbance (the so called surplus torque) in the hardware-in-the-loop (HIL) experiments. The “velocity synchronization scheme” was proposed by Jiao for an electro-hydraulic load simulator (EHLS) in 2004. In some situations, however, the scheme is limited in the implementation for certain reasons, as is the case when the actuator’s valve signal is not available or it is seriously polluted by noise. To solve these problems, a “dual-loop scheme” is developed for EHLS. The dual-loop scheme is a combination of a torque loop and a position synchronization loop. The role of the position synchronization loop is to decouple the motion disturbance caused by the actuator system. To verify the feasibility and effectiveness of the proposed scheme, extensive simulations are performed using AMESim. Then, the performance of the developed method is validated by experiments.