An online chatter detection and control system for the high speed machining of moulds and dies

摘要

Workpiece surface roughness and dimensional accuracy are vital factors in the manufacture of moulds and dies. The occurrence of chatter when machining, particularly during a finishing operation, is detrimental and should be avoided. Following a review of relevant literature including that relating to commercial chatter-suppression systems, the paper details the design, development and implementation of an online system for chatter detection and control. The arrangement utilised a microphone to detect chatter (2-5 kHz) and used root mean square (RMS) and Fast Fourier Transform (FFT) techniques to analyse the signals. Chatter was suppressed by small changes in spindle speed and feedrate (1-10%). The system was implemented on a vertical machining centre and tested using different cutting environments. Initial results showed that chatter was successfully eliminated within 5 iterations (<3 seconds).