Control of Micro-Vibrations of A Machine Head by Using Piezoelectric Actuators

Abstract

This paper discusses vibration control problems of a spindle of various machines. A system for controlling micro-vibrations of the spindle has been presented in which piezoelectric actuators are applied. In this case, three forces act on the spindle simultaneously. One of those is generated by the driving mechanism. It applies to the spindle passing through the arm of the machine. The second is the centrifugal force, and the third is the cutting force which apply to the spindle directly. For the fine cutting, the cutting force is small, so that a controller can be designed with consideration of first two vibration forces. In the present article, the vibration by the driving mechanism is controlled by using the disturbance cancellation method given in our previous work, and a method for controlling the centrifugal force is presented, in which the addition of height of resonance peaks in a frequency domain and the height of control voltages is taken to be a cost function. The coefficients of the transfer function of the controller are decided by minimizing the cost function. Numerical calculations are carried out for some important cases.