Performance Evaluation of Cable-Driven Wrench Applicators: Geometric and Experimental Analysis ^†

Cable-driven wrench applicators (CDWAs) are parallel robotic systems that apply controlled wrenches to the robot end-effector through cable actuation. The presented study introduces a framework for the performance evaluation of CDWAs based on dedicated metrics. It focuses on the geometric analysis of n-cable CDWAs controlling $n-2$ wrench components and on the experimental comparison of a 4-cable architecture with an 8-cable CDWA. The geometric analysis reveals intrinsic properties of the 4-cable system’s tension distribution and inherent limits in achieving specific control objectives. Both simulations and experimental validation demonstrate that the 4-cable CDWA attains comparable performance in wrench control while requiring higher tensions, yet offers greater ease of use and mechanical simplicity.