An improved velocity synchronization control on electro-hydraulic load simulator

The issues of surplus torque in the hardware-in-loop loading simulation are studied. The mathematical model of electro-hydraulic loading simulator (EHLS) is built up. The concepts of surplus torque disturbance coefficients are put forward for the quantitative analysis of the composition of surplus torque, and definition method for the disturbance coefficients is given. Mechanism of suppression of the surplus torque by traditional velocity synchronization scheme and its drawback are analyzed. An improved scheme based on the traditional velocity synchronization scheme is proposed which uses the velocity error between the rudder and loading system to conduct secondary compensation for surplus torque. Effectiveness of the proposed scheme is proved by experimental results. EHLS with the proposed scheme has an ideal effect on dynamic loading, and the ability to suppress surplus torque is improved by more than 25% compared with the traditional velocity synchronization scheme.