Coordinated stabilization for space robot after capturing a noncooperative target with large inertia

A noncooperative target with large inertia grasped by space robot may contain a large unkonwn initial angular momentum, which will cause the compound system unstable. Unloading the unkonwn angular momentum of the compound system is a necessary and diffcult task. In the paper, a coordinated stabilization scenario is introduced to reduce the angular momentum, which has two stages, Momentum Reduction and Momentum Redistribution. For the Momentum Reduction, a modified adaptive sliding mode control algorithm is proposed and used to reduce the unknown angular momentum of target, which uses a new signum function and time-delay estimation to assure fast convergence and achieve good performance with small chattering effect. Finally, a plane dual-arm space robot is simulated, the numerical simulations show that the proposed control algorithm is able to stabilize a noncooperative target with large inertia successfully, while the attitude disturbance of base is small. The control algorithm also has a good robust performance.