Active milling chatter control based on a modified comb filter and robust mixed sensitivity controller

Abstract

Active control approaches based on comb filters have been widely employed to suppress the chatter issue in milling industry. However, due to the limitations in real-time regulations and filtering accuracy induced by conventional comb filter, the automation of active control for chatter still remains to be challenging. Additionally, the current chatter controllers are generally constructed based on theoretical models, making it complex and costly. Herein, a facile yet effective milling chatter active control approach is proposed based on modified comb filter and robust hybrid sensitivity controller. The modified comb filter, which can follow the spindle speed change and accurately detect /filter out the spindle rotation frequency and frequency multiplications, is developed based on the second-order generalized integrator-frequency locked loop (SOGI-FLL) technique. Meanwhile, a robust hybrid sensitivity controller based on an empirical model is proposed. A systematic simulation is conducted to elucidate the performance of the filter and controller, with emphasis on the frequency tracking accuracy, filtering effect, and chatter frequency control effect of the SOGI-FLL. The subsequently experimental results demonstrated that chatter can be suppressed effectively upon low control voltage of actuator, which are in good accordance with the theoretical results. The work highlights the feasibility of this control method in suppressing chatter, providing a new perspective for developing automated active control strategies for chatter.