A Systems Engineering Approach to Design a Smart Tool Post Structure

Abstract

Precision machining has received more and more industry-wide attention as dimensional accuracy becomes a significant measure of quality in a product. The key in achieving today's quality requirement is, therefore, precision of a machine tool. Since the invention of the first CNC machine tool in the 1960s, machine tool research has entered an almost stagnant stage. There are numerous reasons for the slow progress, and the lack of system- wide studies of the machine tool performance is one of them.<P>The research presented in this thesis focuses on improving machining accuracy using a systems engineering approach. A conventional lathe during machining is taken under consideration as a machining system. The tool post is identified as a critical component in the machining system to achieve the defined machining accuracy. Smart material made actuators are used to design a new tool post structure that is capable of carrying out an active vibration control during machining.<P>In this thesis research, the fabrication of the designed tool post is completed. Results obtained from the initial tests strongly demonstrate its capability to attenuate tool vibration during machining in an active and intelligent way. Thus, the smart tool post system fulfills the design objective of achieving microscopic level machining precision on a low-cost conventional machine tool platform. Suggestions on the actuator specifications are made for further improvement on vibration compensation.