Performance Analysis of Cable-Driven Wrench Applicators

Cable-driven wrench applicators are widely used in robotics due to their lightweight design, large workspace, and ability to exert wrenches. Usually, a subset of wrench components needs to be precisely controlled depending on the application at hand, whereas the other wrench components need to be managed according to some criteria. This paper presents a framework for analyzing and comparing cable systems equipped with an arbitrary number of cables greater than the cardinality of the wrench subset they need to apply. Three performance metrics, including one for selecting the tension distribution and two for evaluating cable tensions and the quality of the applied wrench, are introduced. The proposed framework is applied to assess the feasibility of reducing the number of cables to be used in a rehabilitation task, enhancing accessibility and ease of use for the physiotherapist during the exercise. Simulation results validate this possibility.