Investigation of the influence of elastic cables on the force distribution of a parallel cable-driven robot

Cable-driven parallel robots rely on cables instead of rigid links to manipulate the endeffector in the workspace. The cable force distribution is the result of cable elongation and the force coupling at the endeffector. In this paper, the experimental investigation of the force coupling is presented. In the experiment, the cable length in each individual cable was varied, and the resulting progression of the force distribution and the deflection were measured. With this approach, the steady state gain matrix for the transfer function between a delta in cable length and the resulting changes in the cables forces can be determined. Furthermore, the impact of the observed force coupling on cable force control is discussed