Managing the redundancy of N—1 wire-driven parallel robots

Abstract

We consider wire-driven parallel robot with N 4 wires that are connected at the same point on the platform. Such robot has 3 d.o.f. but it is non-redundant (e.g. we cannot control the tension in the wires) as there will always be only at most 3 wires under tension simultaneously. We consider in this paper three approaches that make this robot really redundant: Elasticity in the wires, using counterweights in the wires or attaching the redundant wires to a fixed point on the other wires. We show that these methods may be effective but still require further studies.