Motion Planning Method of Redundant Dual-Chain Manipulator with Multiple Constraints

Redundant and dual-arm manipulators exhibit good flexibility and excellent cooperation ability, respectively. Therefore, both these manipulators are used to design a redundant dual-chain manipulator with two kinematic chains and a fixed base. In addition, a motion planning method is proposed using a manifold analysis based on the characteristics of this designed manipulator to resolve the difficulty associated with motion planning for a dual-chain manipulator under multiple constraints. Firstly, the paths of the two end-effectors of the dual-chain manipulator are planned synchronously by the Rapidly-exploring Random Tree Star (RRT*) in the Cartesian space. Then, joint trajectories that correspond to the paths are generated by the manifold analysis in the joint space. In this method, the manifold continuity constraint is added to the end-effector path planning of RRT* to ensure that the planned paths have continuous joint trajectories. The joint trajectories are optimised by analysing the performance of the manipulator on the manifolds to improve their motion performance. The prototype experiments of loose coordination and tight coordination are provided in the experimental section; these experiments prove the feasibility and practicability of the motion planning method proposed in this study.