Vibration reduction of flexible rope-driven mobile robot for safe faade operation

Abstract

In recent years, cable-driven-parallel robots (CDPRs) have been studied for faade operations. There are various types of CDPRs; however, under-constrained CDPRs are capable of wider operating in faade workspaces than over-constrained CDPRs. Therefore, in this study, a dual ascender robot (DAR) was used for faade operations. Herein, two suggestions for safe faade operations are presented. First, a flexible nylon fiber rope was modeled such that the vibration direction, natural frequency, and damping ratio of the DAR could be converted through a Jacobian matrix and modal decomposition from the rope model. Second, input shaping control was applied to reduce vibrations, based on the vibration model of a DAR using the rope model. Modal decomposition was verified using a verification experiment, and the effect of input shaping was evaluated by comparing the w/ input shaping and w/o input shaping experiments. w/ input shaping case was shown about 48% reducing robot vibration and about 35% shortening settling time compare with w/o input shaping case.