On Kinetostatics and Workspace Analysis of Multi-platform Cable-Driven Parallel Robots with Unlimited Rotation

Abstract

Cable-driven parallel robots are a special kind of parallel mechanism which use cables instead of rigid prismatic actuators to control a single platform. This paper presents a modeling approach to replace the single platform by multiple platforms. With this approach, it is possible to perform unlimited rotation with cable robots end-effector by relatively positioning these multiple platforms. We show how this class of cable robots can be modeled as multi-body system, where platforms are connected with linkages by using revolute joints. These linkages can be seen as coupling elements. For example, using a crankshaft as coupling element, cable robots can perform novel motions such as unlimited rotation. We find a generic approach describing such multi-platform cable robot systems, after which force distribution and workspace of a case study are analyzed. Finally, we find out that inclusion and total orientation workspace are nonempty, considering joint reaction forces and platform and linkage masses. Furthermore, our modeling approach can be used for spatial multi-platform cable robots with revolute joints.