ACTIVE CHATTER SUPPRESSION OF SLENDER BORING BAR USING PIEZOELECTRIC ACTUATORS

The chatter suppression described in this paper is based on the applic ation of active dampers to a slender boring bar. Chatter vibration sig nals detected by a pickup are fed to a computer. After calculating the chatter frequency and the corresponding phase shift parameter, the co mputer supplies the amplified signals to piezoelectric actuators with the same phase as that of the vibration velocity of the boring bar. As a result of this, the actuators generate damping forces; that is, the y act as active dampers. It has been confirmed in cutting tests that t he active damping system adapts to change and fluctuation of the chatt er frequency and suppresses chatter well. Furthermore, it has become c lear that there is an optimum position of the active damper for chatte r suppression.