Time-varying input shaping technique applied to vibration reduction of an industrial robot

Abstract

It is widely and frequently observed that industrial robots conducting fast motion involve serious residual vibration, the period of which varies with time. To this problem, this paper presents a practical solution by providing a practical design and application of time-varying input shaping technique (TVIST) for an industrial robot. To suppress the time-varying vibration, at first, a guideline for designing practical TVIST is presented. Following the guideline, then, we design TVIST for a large size 6 degrees of freedom industrial robot. In doing so, a simple yet effective equation is derived from robot dynamic equations to estimate the time-varying period. Furthermore, a simple payload adaptation scheme is also included. The TVIST thus designed is experimented on the industrial robot under spatial motion and payload variation conditions. The experimental results show that the residual vibration is reduced to less than 10% of original one in magnitude, demonstrating that the efficiency of the TVIST does not compromise its effectiveness.