Abstract: An efficient computation method of the force-closure workspace is proposed to improve the solution efficiency of the existing methods for determining the force-closure workspace of 6-DOF cable-driven manipulators. The proposed method is realized by calculating the null space of the structure matrix and solving the linear matrix inequalities. The detailed calculation procedures of the force-closure workspace for the incompletely restrained, completely restrained and redundantly restrained 6-DOF cable-driven parallel manipulators are given respectively. The proposed method is implemented on the 6-DOF cable-driven parallel manipulator with eight cables, and the rapidity of the method is validated through simulation results.

Key words: Cable-driven, Force-closure workspace, Linear matrix inequalities, Null space of matrix, Parallel manipulators