Design and analysis of a class of planar cable-driven parallel robots with arbitrary rotation

摘要

This paper presents and analyzes a novel class of planar cable-driven parallel robots. The design allows an arbitrary rotation of the end-effector by wrapping the cables on a cylindrical fixture on the end-effector platform. In contrast to the state of the art, this results in a simple and robust design without additional moving parts attached to the end effector. Based on Burnside's lemma known from group theory, the set of all possible design configurations for a fixed number of cables is derived. Moreover, the workspace is analyzed by means of the classical manipulability measure known from the literature. In order to also capture the minimum tension in the cables and the directional dependence of the achievable forces, which are determining factors for the workspace, a new force manipulability measure is introduced. This yields results which are related to the well-known wrench-feasible workspace. The proposed concepts are demonstrated by two different designs for planar cable-driven parallel robots with 4 and 6 cables.