A Motion Control Scheme in Wire Length Coordinates for Parallel Wire Drive Systems.

Abstract

Some types of parallel wire robots have been already proposed so far. Those parallel wire robot are useful for fast motion, heavy load and so on. Since each wire generates one directional force (tension), parallel wire drive system must be redundant actuating. In this paper, we analyze stability on a motion control scheme in wire length coordinates for parallel wire drive system. Taking account of such redundancy on actuation, motion stability is analyzed.by using a Lyapunov function. Basing on “Vector Closure”, it is proven that each wire length converges to the corresponding desired value and the internal force also converges to desired one. Finally, we experimentally investigate the motion accuracy on the proposed control scheme by using a parallel wire robot with seven wires.