A Force- and Position-Based Distortion Compensation Method for a Hardware-in-the-Loop Simulator of Space Docking

Hardware-in-the-loop simulation is an important way to test the complex contact process of two spacecraft docking in space. Hardware-in-the-loop simulations are known to be unstable and divergent because of various unexpected dynamics, including delays in the system. Existing force compensators for the force-sensing delay, dynamic response delay, and structural deformation of the upper and lower platforms require real-time identification of the contact parameters of the docking mechanisms (DMs), which is difficult because of the unknown contact model structure. However, the existing force- and position-based compensation methods do not consider the structural deformation of the upper platform. In this study, a force- and position-based compensation method is proposed to compensate for the force-sensing delay, actuation-response delay, and structural dynamic position error of the lower and upper platforms. It is not necessary to identify the contact parameters of the DMs. Many verifications by software and experiments show that by using the proposed method, a stable simulation with satisfactory accuracy can be achieved under different simulation conditions. Capture experiments on a space manipulator are provided to demonstrate the applications.