Control of oscillating multi-mass system with gear backlash by digital observer

Abstract

On a variable speed control of motors used in industrial plants and industrial robots, a shaft torsional oscillation is often generated when a motor and a load are elastically coupled with a shaft. Such an oscillation may result in damage to the machine. This paper is intended to theoretically explain the fact that a shaft torsional oscillation can be suppressed by using the digital observer regardless of the presense of the gear. In this paper, we conducted tests on two shafts with resonant frequencies at 10.5 Hz and 16 Hz using a full-digital control equipment for controlling DC motors with the digital observer in order to confirm the oscillation control effects. © 1990, The Institute of Electrical Engineers of Japan. All rights reserved.