Static Analysis of a Two-Platform Planar Cable-Driven Parallel Robot with Unlimited Rotation

Abstract

Comparing cable-driven parallel robots (short CDPRs or cable robots) with conventional parallel mechanisms, CDPRs have advantages in terms of flexibility, dynamics, and workspace size. In general, the rotational capabilities of parallel mechanisms without any additional actuator system are limited. This paper presents an approach for the design and analysis of a CDPR which allows an unlimited rotation about one axis by actuating solely cables. The unlimited rotation consists of a relative positioning between multiple platforms. The kinematics, static force distribution, and the workspace of a planar cable robot are analyzed. A formulation of the structure matrix for cable robots with multiple platforms is given, allowing to use conventional algorithms for calculation of force distributions. The performed simulation shows different characteristics of the force distribution and workspace of this new type of cable robot contrary to conventional ones. Finally, the conclusion shows that the dextrous workspaces of the investigated CDPR is nonempty.