A Force and Displacement Compensation Method Toward Divergence and Accuracy of Hardware-in-the-Loop Simulation System for Manipulator Docking

The hardware-in-the-loop (HIL) simulation system for manipulator docking is an important means to simulate the flexible manipulator on-orbit docking dynamics process. However, the delay of the HIL simulation system leads to the accuracy loss and divergence problems of the system; in this paper, a force and displacement compensation method was proposed toward these problems of the manipulator docking HIL simulation system for single-mass, multi-stiffness, and multi-damping contact. First, time delays including the contact force delay and the force measurement delay were considered. The real-time on-line identification method was applied in the time-varying HIL simulation system, and the contact force delay was compensated by the identification parameters and the discrete force compensation model. The force measurement delay was compensated by a phase lead based force compensation model. The dynamic response model of the motion simulator was not required in the force compensation. In addition, the displacement phase lead compensation model was used to reduce the displacement phase delay of the motion simulator, which improved the reproduction accuracy of the HIL simulation system. Based on the simulation and experimental results, it is shown that the proposed method can effectively and satisfactorily prevent the divergence and improve the accuracy of the reproduction.