Real-time chatter detection and automatic suppression for intelligent spindles based on wavelet packet energy entropy and local outlier factor algorithm

• Published in: International journal of advanced manufacturing technology Vol. 103; no. 1-4; pp. 297 - 309
• Main Authors: Yao, Yung-Chen, Chen, Yu-Hsuan, Liu, Chien-Hao, Shih, Wen-Pin
• Format: Journal Article
• Language: English
• Published: London Springer London 01.07.2019; Springer Nature B.V
• Subjects: Algorithms; CAE) and Design; Chatter; Computer-Aided Engineering (CAD; Data analysis; Dimensional stability; End milling; Engineering; Entropy; Frequencies; Industrial and Production Engineering; Machine tools; Mechanical Engineering; Media Management; Milling (machining); Milling machines; Modules; Numerical controls; Original Article; Real time; Spindles; Three dimensional models; Vibration; Wavelet analysis; Automatic chatter suppression; Intelligent spindle; Stability lobe diagram; Chatter identification; Relative wavelet packet energy entropy; Local outlier factor; Real-time monitoring; Anomaly detection
• ISSN: 0268-3768; 1433-3015
• DOI: 10.1007/s00170-019-03551-2

In this research, we proposed a real-time chatter detection and suppression module for intelligent spindle to increase machining efficiency and processing yield. For early detections of chatters, the relative wavelet packet energy entropy with high sensitivity in the high-frequency band and the local outlier factor (LOF) algorithm were utilized as chatter features and classifications, respectively. Based on the pre-obtained three-dimensional stability lobe diagram (SLD) and a LOF-based trained model, the module could real-time monitor and suppress chatter during machining processes. The module was implemented and experimentally examined with the CNC end-milling machine under five different cutting conditions for verifying the capabilities of real-time chatter identifications and suppressions. It was demonstrated that the module could detect the onset of chatter and suppress it by changing the cutting conditions to avoid damages on the surfaces of working piece due to severe chatters.