Input Shaping for Feed-Forward Control of Cable-Driven Parallel Robots

Abstract

This paper deals with the use of input-shaping filters in conjunction with a feed-forward control of cable-driven parallel robots (CDPRs), while integrating cable tension calculation to satisfy positive cable tensions along the prescribed trajectory of the moving platform. This method aims to attenuate the oscillatory motions of the moving platform. Thus, the input signal is modified to make it self-cancel residual vibrations. The effectiveness, in terms of moving-platform oscillation attenuation, of the proposed closed-loop control method combined with shaping inputs is experimentally studied on a suspended and nonredundant CDPR prototype. This confirms residual vibration reduction improvement with respect to the unshaped control in terms of peak-to-peak amplitude of velocity error, which can achieve 72% while using input-shaping filters.