Research On Solution Method And Performance Of The Workspace Of Redundant Cable-Driven Parallel Robots

Cable-driven parallel robots possess a number of promising advantages over the conventional strut-support parallel robots, such as simple and light-weight mechanical structure, high-loading capacity, large reachable workspace and fast movement velocity. Redundant cable-driven parallel robot can reduce singnlar configuration of the workspace and advance the workspace performance. So solution method and performance of their workspace become a research emphasis in this thesis.This paper deduces the forcescrew equilibrium equations of cable-driven parallel robots and studies the similarity relationship between muti-fingered robotic grasping mechanisms and cable-driven parallel robots. The convex condition of muti-fingered robotic grasping are applied on cable-driven parallel robots and achieve the decision theorem of forcescrew in cable-driven parallel robots. In addition, this thesis expounds definition and theorem of the force wrench-closed workspace and the wrench-feasible workspace, put forward a new method based on the theory of dimension reduction to solve above two kinds of workspace, and verifies the validity of this method through the traditional method or theorem.Finally, various kinds of evaluation methods including Global Condition Index, Local Condition Index and the workspace area or volume are used to evaluate workspace performance. By changing tension range of the cable, attitude angle of end-effector, external force screw and redundancy rate their influence on the workspace performance are analyzed and obtain a general conclusion used to design a good performance mechanism.