Robust Control of Dual-Arm Space Robot Systems with Two Objects in Inertial Space

In this paper, the kinematics and dynamics of free-floating dual-arm space robot systems are analyzed, and it is shown that the dynamic equations of the system are nonlinearly dependent on inertial parameters. In order to overcome the problem proposed above, the system is modeled as under-actuated robot system, and the idea of augmentation approach is adopted. It is demonstrated that the dynamic equations of the system can be linearly dependent on a group of inertial parameters with augmented inputs and outputs. Based on the results, the robust control scheme for free-floating dual-arm space robot system with uncertain inertial parameters to implement the point-to-point motion in inertial space is developed, and a planar dual-arm space robot system with two objects is simulated to verify the proposed control scheme. The proposed control scheme is computationally simple, because we guarantee the controller robust to the uncertain inertial parameters rather than explicitly estimating them online. In particular, it need not require controlling the position and attitude of the floating base.