Industrial applications of chatter stability prediction and monitoring system for turning processes

Chatter vibrations result in poor surface finish, reduced productivity, and shortened tool life in metal cutting. Although chatter stability and monitoring techniques are broadly studied in literature, the deployment of process monitoring system in the shop floor still presents a challenge. In this paper, we have constructed an online prototype system for industrial applications including two independent modules of chatter stability prediction and monitoring cooperatively. Turning processes are considered. Firstly, the stability charts are evaluated analytically by the application of the Laplace transform. The charts obtained can assist the operators in choosing appropriate cutting parameters before machining. Secondly, the characteristics of chatter are extracted in the time and frequency domains. The norm of chatter arising is formulated in accordance with the variance and spectrum of vibration signals. The corresponding threshold is confirmed relatively in comparison with the characteristics of stable cutting states recorded in the reference database. Thirdly, the algorithms and modules introduced are implemented with the combination of the advantages of MATLAB and C# programming, in which delay strategy and overlap processing can improve the accuracy and performance of the system. Finally, the effectiveness of the techniques and system presented here was verified by experimental results of the industrial machining trials.