A two-arm flexible space manipulator system for post-grasping manipulation operations of a passive target object

Space Manipulator Systems (SMSs) are complex systems made of a platform equipped with one or more deployable robotic arms and they will be playing a major role in future autonomous on-orbit missions. The latter may as well involve manipulation operations of the target object which needs to be moved from an initial configuration to a final one suitable for the specific task under consideration. In the present study, the mission being analyzed concerns the manipulation of a passive body by means of a flexible SMS after grasping operations have been performed. The dynamics model is derived in a three-dimensional context (non-linear formulation for the rigid-body motions and linear for the elastic dynamics). The SMS involved in the investigation has two actuated seven-degree of freedom arms. Furthermore, the modeling of the grasp constraint existing between the SMS end-effectors and the target object is a critical issue which is addressed in the present paper. A combination of Jacobian Transpose and Proportional-Derivative Control is synthesized to accomplish the desired mission goals. Numerical results proving the effectiveness of the proposed strategy are presented and discussed.