End-effector pose and arm-shape synchronous planning methods of a hyper-redundant manipulator for spacecraft repairing

Abstract

Compared with traditional industrial robots, a hyper-redundant manipulator (HRM) has better flexibility, especially in obstacle avoidance, narrow restricted space crossing and fault-tolerant control. However, mathematical modeling and trajectory planning methods for how a HRM can safety traverse these narrow-confined spaces are highly challenging. This paper proposes an end-effector pose and arm-shape synchronous planning method for a HRM passing through space narrow parallel slits based on extended Jacobian matrix redundancy decomposition(EJMRD). Firstly, for the limited confined space environment, the concept of end-effector poses and arm-shape synchronization constraint is introduced, and the overall framework of the method is given. Then, the kinematics model of the HRM is deduced, and the Jacobian matrix(JM) of this “hybrid active-passive driven-segmented linkage” structure is simplified. Further, the HRM is segmented by the dynamic segmentation method(DSM). Secondly, the arm-shape constraints of the inner arm segment(IAS) are integrated into the JM, and the extended Jacobian matrix(EJM) is established. In addition, the null-space of the EJM is redundantly decomposed to achieve obstacle avoidance of the outer arm segment(OAS). Finally, the Matlab-ADAMS co-simulation and experimental system is built. The above algorithm is verified by the simulation and experiment.