Relative vibration suppression in a positioning machine using acceleration feedback control

Abstract

A method to suppress the residual vibration of relative displacement is proposed. In factory automation, the positioning machines are precisely controlled by servo motors; however, their reaction force will unavoidably vibrate the machine stand on which the motors are mounted. A common problem is that the resulting residual vibrations cause disturbances that prevent high speed and accurate positioning, due to the inherent flexible structures in the machine stand, thereby unexpectedly extending the settling time in some industrial applications. This paper presents machine stand acceleration feedback (MSAFB) control, which detects the acceleration signal of the machine stand using an accelerometer to improve the robustness against disturbances from the environment and uncertainty in the system. This feedback strategy is superior to input shaping strategy, which is based on feedforward control. Simulations and experiments show the effectiveness of the proposed MSAFB controller, which was designed specifically for mechanical plants with rocking mode vibration.