Gravity balance technique of the docking ring in the spacecraft docking testbed

To simulate the zero-gravity activities of the docking ring in a spacecraft docking testbed, a gravity balance device with high respond speed and high precision was designed. Mechanism scheme and working principle of the gravity balance device are introduced. The characteristics of the follower mechanism, which may interfere with the gravity balance system, are analyzed in detail. The accuracy of the gravity balance system is experimented. Analysis and experiment results show that the gravity balance device meets the requirements on friction resistance and inertia resistance. The precision of the gravity balance reaches 1.1%.