Robust control of space robot for capturing objects using optimal control method

The capturing operation for the space object by space robot can not be avoided in order to complete the on-orbital services, such as repairing, maintaining, inspecting and exchanging orbital replace unit (ORU). However, there are some unknown factors, such as the unknown payload and unknown modeling of object and the other uncertain dynamic parameters in the space robot, will affect the performance and the security of the space robot when the space robot captures the unknown object. Therefore, it is significant to design a robust control law that will guarantee the performance and security of the space robot under these uncertainties. Here, we propose a new optimal control method to robust control of space robot. To design the robust control law, we translate the robust control problem into an optimal control problem, where the uncertainties are reflected in the objective function index. We optimize this objective function to realize the robust control. An illustrative example shows that the proposed approach is remarkable.