Dynamic analysis of cable-driven parallel mechanisms

A cable-driven parallel mechanism (CDPM) possesses a number of promising advantages over the conventional rigid-link mechanisms, such as simple and light-weight mechanical structure, high-loading capacity, and large workspace. However, the formulations and results obtained for the rigid-link mechanisms cannot be directly applied to CDPMs due to the unilateral property of cables. For a CDPM, dynamic formulation is only valid as actuators exert positive torques. In this paper, cable winding method is studied as it improves the whole dynamic performance of the system. This is followed by dynamic formulation. A generic approach based on dimension reduction technique, which is successfully implemented through a computationally effective recursive algorithm, is proposed to check the existence of positive torques. Since torque optimization problem is modeled in a standard linear programming form, the optimal solution can be efficiently obtained. Two simulation examples are provided to demonstrate the effectiveness of the proposed solution approach