Adaptive Sliding-Mode Control of Space Robot during Manipulating Unknown Objects

In the future space application, space robot is playing more and more important roles in on-orbital retrieval missions, such as catching an uncontrolled and unknown satellite. As well known, the contact and impact can not be avoided fully when the space robot captures the unknown objects. However, these unknown factors, such as the unknown payload and unknown contact force and the other uncertain dynamic parameters in the space robot system, especially, the contact ad impact reaction force to the hand of space robot, will affect the robustness of the controller and the security of the space robot. Therefore, it is significant to design a composite control law that can suppress these uncertainties, we propose an adaptive sliding-model control algorithm to take care of the unknown payload and impact force. An illustrative example shows that the proposed controller is robust and perfect to suppress the uncertainties from external environment.