Analysis of wire elasticity for wire-driven parallel robots

Abstract

This paper presents an experimental study of the elasticity of wires that may be used for wire-driven parallel robot. Although wire behavior have been studied since a long time (e.g. in civil engineering) their use in parallel robots are quite different as they are submitted to large changes in length and tension while being usually much lighter than the one used in civil engineering. These experiments show that the tension in a wire submitted to a given change in length ΔL is a function of ΔL but also of time and we propose an empiric model to characterize this deformation. However we show that an appropriate elastic model may still be used for control purposes, provided that the zero-tension wire lengths are regularly updated through calibration. © Springer Science+Business Media B.V. 2009.