Research of the Low Impact Space Docking Mechanism Based on Impedance Control Strategy

In order to solve the violent collision and energy consumption problems of conventional space docking mechanism in the docking process, we developed a set of low impact docking mechanism based on impedance control. The docking mechanism adopts the peripheral docking type, the active end of which is a 6-UPS parallel mechanism which is driven by six electric cylinders installed on the fixed platform. For the purpose of the safety of the docking mechanism in the process of docking buffer, we need to monitor the contact force between the active end and environment, so tension-pressure sensor is installed on the end of each electric cylinder. This paper designed a kind of highly efficient force coupling algorithm to convert the six separate force into a six-dimensional integral contact force and then established the dynamic relationship between the contact force and the adjustment of the position and posture to ensure the contact force in the docking process not appear large overshoot. Finally, we completed the compliant docking experiments, which proved that the scheme of low impact docking mechanism is feasible and that the docking mechanism can finish the expected mission.