A new control scheme of cable-driven parallel robot balancing between sliding mode and linear feedback

Abstract

This paper deals with the design of a robust control scheme for a suspended Cable-Driven Parallel Robot (CDPR), composed of eight cables and a moving-platform (MP), for a pick-and-place application of metal plates of various shapes, sizes and masses. The set composed of the MP and a metal plate can have a mass of up to 700 kg. In order to achieve good accuracy and repeatability of the MP pose despite the variability of the transported mass, a robust control scheme must be implemented on the robot. A recently developed controller balancing between sliding mode and linear algorithms (SML) is considered for the application. The performances of the SML controller are analyzed on a CDPR prototype located at IRT Jules Verne, Nantes, France, along a test trajectory for several payloads. The results obtained without any information on the platform or metal plate mass are compared to those of standard proportional-derivative (PD) based control schemes.