A fast tool servo design for precision turning of shafts on conventional CNC lathes

• Published in: International journal of machine tools & manufacture 2001-05, Vol.41 (7), p.953-965
• Main Authors: Zhu, Wen-Hong, Jun, Martin B., Altintas, Yusuf
• Format: Article
• Language: English
• Subjects: Actuator; Actuators; Applied sciences; Computer control systems; Control system analysis; Control system synthesis; Cross-disciplinary physics: materials science; rheology; Cutting; Exact sciences and technology; Laboratory procedures; Laser position sensor; Machining, milling; Materials science; Materials synthesis; materials processing; Metals. Metallurgy; Metrology, measurements and laboratory procedures; Numerical control systems; Other machining methods; Physics; Piezo-electronics; Piezoelectric devices; Precision; Precision engineering; Production techniques; Robustness (control systems); Servomotors; Sliding mode control; Turning; Turret lathes; Workshop procedures (welding, machining, lubrication, bearings, etc.)
• ISSN: 0890-6955; 1879-2170
• DOI: 10.1016/S0890-6955(00)00118-8

A technique for precision turning of shafts on conventional CNC turning centers is presented. The shaft is semi-turned on a conventional CNC lathe. The precision finish turning operation is delivered by a piezoelectric based fast tool servo which is mounted on the same CNC lathe's turret. The precision tool tip motion is delivered by a proposed sliding mode controller which is robust to changes in the cutting process and hysteresis in the piezo actuator. Sliding mode controller is also quick to compensate the cutting force disturbances, and keeps the tool tip at the desired location within the displacement measurement sensor resolution (±0.1 μm). The fast tool servo system is packaged in a PC, and its effectiveness is demonstrated on a bearing location turning.