ONLINE CONTROL OF MACHINE-TOOL VIBRATION IN TURNING

This paper presents a system developed for on-line vibration control o n a turning lathe. Relative vibration between the workpiece and the cu tting tool is sensed with the help of a bifurcated bunch of optical fi bres which is then phase shifted, amplified and fed back to a speciall y designed piezoelectric vibrator supporting the tool. Whenever a vibr ation occurs, leading the machine tool-cutting process system to insta bility, the closed-loop feedback contour, with the help of the vibrato r-exciter, generates an equal and opposite force to stabilize the vibr ation. Results obtained by mathematical modelling and experimental inv estigations indicate a significant improvement in the dynamic characte ristics of the machine tool resulting in considerably higher productiv ity, accuracy and finish. (C) 1997 Elsevier Science Ltd.