A Topological Approach to Workspace and Motion Planning for a Cable-Controlled Robot in Cluttered Environments

Abstract

There is a rising demand for multiple-cable controlled robots in stadiums or warehouses due to its low cost, longer operation time, and higher safety standards. In a cluttered environment, the cables can wrap around obstacles, but careful choice needs to be made for the initial cable configurations to ensure that the workspace of the robot is optimized. The presence of cables makes it imperative to consider the homotopy classes of the cables both in the design and motion planning problems. In this letter, we study the problem of workspace planning for multiple-cable controlled robots in an environment with polygonal obstacles. This letter's goal is to establish a relationship between the boundary of the workspace and cable configurations of such robots and solve related optimization and motion planning problems. We first analyze the conditions under which a configuration of a cable-controlled robot can be considered valid, discuss the relationship between cable configuration, the robot's workspace and its motion state, and using graph search based motion planning in h-augmented graph perform workspace optimization and compute optimal paths for the robot. We demonstrated the algorithms in simulations.