Robust control of dual-arm space robot system with two objects in joint space

In this paper, the robust control problem for free-floating dual-arm space robot system with two objects is discussed. Firstly, the kinematics and dynamics of free-floating dual-arm space robot system with two objects are analysed. In order to overcome the difficulty that the dynamic equations of the system are nonlinearly dependent on inertial parameters, 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. And then based on the above results, the robust control scheme for dual-arm space robot system with uncertain inertial parameters to track the desired trajectories in joint space is proposed. 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 addition to this, it need not require controlling the position and attitude of the floating base. Finally, a planar free-floating dual-arm space robot system with two objects is simulated to verify the proposed control scheme.