Abstract:

In order to find the wrench closed workspace boundary of the Planar Multibody Cable-Driven Mechanism, a matrix null space method is proposed. By analyzing the cable force Jacobian matrix, the condition for guaranteeing non-negative cable forces are derived, and the boundary of wrench closed workspace and wrench feasible workspace are solved according to the condition. The Monte Carlo method is used to optimize the the position of the motor and cable connection point to maximize the wrench feasible workspace and ensure that the trajectory of the mechanism is within the wrench feasible workspace. Parameter optimization and experimental verification of a configuration of the planar serial two-link mechanism show that the optimal configuration guarantees the desired trajectory in the wrench feasible workspace, and that the analytical method can accurately derive the boundary of the wrench closure workspace.

Key words: cable-driven, null space, wrench closure workspace, wrench feasible workspace