On Determining Shortest Path in Joint Space of a Cable-Driven Parallel Robot for Point-to-Point Motion

This paper presents a methodology to determine the shortest path in the joint space of a cable-driven parallel robot for point-to-point motions. The formulation is based on the joint space domain i.e., cable length and the shortest path in joint space is determined between the two points. The path is constrained by the 4th degree polynomial in the Cartesian space and the objective function representing the total path length in the joint space is formulated. The parameters of the path are obtained by minimizing the objective function using genetic algorithm while satisfying the non-negative cable tension constraints. The proposed methodology is validated using a 3-DOF planar and a 6-DOF spatial cable-driven robot. The obtained optimized shortest path is compared to a straight-line path and the results obtained shows a significant reduction in the joint space path length of a cable-driven parallel robot for the optimized path. The reduction will be even more significant for the large-scale cable-driven parallel robot.