An Omnidirectional Compliant Docking Strategy for Non-Cooperative On-orbit Targets: Principle, Design, Modeling, and Experiment

Aiming at the problems of excessive contact force and difficulty in compensating noncoaxial errors during rigid docking of noncooperative on-orbit targets, a 3R-1T omnidirectional compliant docking joint (OCDJ) with multidimensional decoupling springs-dampers is proposed. The OCDJ can not only generate passive flexible motion to compensate eccentricity and deflection, but also buffer and unload six-dimensional spatial impulses. The dynamic differential equations of spacecraft coupled with OCDJ are established by using the Kane method, and its effectiveness is verified. Under 20 typical noncoaxial operating modes, the rationality of applying OCDJ to the compliant docking tasks is verified through the comparative simulations of rigid and flexible docking. Moreover, the semi-physical system of compliant docking strategy is developed based on an air-floating platform and multi-DOF satellite simulators. The experimental results show that the compliant docking strategy can effectively reduce the peak value of the contact force and expand the docking range.