Durability-aware trajectory planning and quasi-static control of a continuum parallel robot for industrial applications

Overview & Synopsis

This paper addresses durability-aware trajectory planning and tracking strategies for the motion of the platform in an extensible planar tendon-actuated continuum parallel robot (CPR). The proposed planning approach combines the A* algorithm with the Geometric Variable Strain (GVS) static Cosserat rod model, incorporating a durability-related cost alongside Euclidean distance to enhance the durability of the robot's legs in pick-and-place applications. Simulation results demonstrate a 23% reduction in the durability-related cost compared to the shortest-path trajectory. Additionally, the same GVS static model is used to extend the classical Jacobian-based controller to the CPR case, with multiple legs geometrically constrained, for precise and robust quasi-static tracking of the planned trajectories. Experimental validation is conducted under nominal conditions and in the presence of external disturbances, including end-effector loading and temporary manual perturbations, demonstrating the effectiveness and robustness of the proposed strategies, achieving a mean tracking error below 0.84% and a maximum error below 4.2%, with respect to the length of the CPR leg.