A Novel Cable-Driven Parallel Robot With Movable Anchor Points Capable for Obstacle Environments
Hao An, Han Yuan, Kai Tang, Wenfu Xu, Xin Wang
Abstract
Cable-driven parallel robots (CDPRs) have the characteristics of large workspace and fast response speed, which attracted lots of interests in the past decade. Most of the CDPRs use flexible cables to manipulate the moving platform while the length of cables is changed by the winches fixed on the base. Consequently, interferences among the driving cables, the moving platform, and the environment become inevitable problems, which significantly limit the effective workspace of CDPRs and its performance in complex multiobstacle environment. This article proposes a novel CDPR with movable anchor points (M-CDPR). The movable anchor point of each driving cable can move along the track on the fixed frames. Besides, we establish the kinematics and dynamics of the M-CDPR, and propose the collision detection method and the obstacle avoidance algorithm. Simulation analyzes indicate that the wrench-feasible workspace of the M-CDPR increases 456.06% compared with traditional CDPRs in the same dimension. Moreover, the M-CDPR can realize obstacle avoidance without changing the desired trajectory under different conditions when there exist multiple static obstacles, or both moving and static obstacles. In addition, a prototype is fabricated, consisting of eight driving cables and eight movable anchor points. Experimental results show that the proposed M-CDPR performed well in an environment containing a number of static and/or moving obstacles without any interference.