The Study Of Cutting Chatter Recognition And Prior-Suppression Methodology

Manufacturing is developing in the direction of high-speed, high-precision and high-flexibility, but it is fundamentally limited by the onset of chatter, which causes deterioration of the surface quality, along with excessive tool wear, tool breakage and noise. Researching and seeking appropriate control methodology of chatter is a pressing problem in manufacturing field.The chatter mechanism is complicated and is a popular topic for both academic and industrial research. It is shown that regenerative chatter, which occurs when vibration between the cutting tool and work piece modulate the cutting force, leading to a self-excited vibration, is the main form in metal cutting process. It has great impact on cutting stability. Thereby, the study of recognition and online control of regenerative chatter is of great significance for improving cutting stability.The thesis presents a systemic study on regenerative chatter, including its mechanism, recognition and online monitoring. The cutting stability condition is studied to find the stable region, conditional stable region and unstable region, and how the structural dynamical parameters influence the stability is also analyzed by using computer numerical simulation, which provides the guidance for the chatter recognition and control. Also, it is studied and shown that chatter can be suppressed by regulating cutting parameters, and it is shown that the spindle speed regulation is the most convenient and effective way. On the basis of chatter characteristics analysis, the thesis puts forward a new way which includes the chatter signal characteristics in both time and frequency domain, to diagnose and predict chatter in the early stage. For the purpose of putting the researching results above into practice, the thesis gives software to monitor the chatter and stabilize the cutting process online.