Input Shaping to Reduce Vibration in Human-Operated Very-Flexible-Link Robot Manipulator

Abstract

Human-operated manipulators, such as construction crane, gantry crane, and tele-operated robot manipulator, are refrained from fast slewing because of the vibrations of its link and payload. To be long, light, fast, and to carry large payload, the manipulatorIs natural frequencies fall within the controller bandwidth resulting in resonance. In this paper, we apply the input shaping technique, in which the reference position signal is convolved with a properly designed impulse sequence to avoid exciting the natural frequencies, to a very-flexible-link robot manipulator to significantly reduce vibration. The technique is in real-time; therefore, the given reference position can be arbitrary and need not be known a priori, which suits the human-operated setting. Experimenting with a scale-down robot confirms the effectiveness of the technique in reducing slewing vibration. The result can be readily extended to a much-larger human-operated manipulator that vibrates.