SUBJECT: Ph.D. Dissertation Defense
BY: Austin Chen
TIME: Monday, March 13, 2006, 9:00 a.m.
PLACE: MARC Building, 201
COMMITTEE: Dr. Thomas R. Kurfess, Chair (ME)
Dr. Steven Y. Liang (ME)
Dr. Shreyes N. Melkote (ME)
Dr. Chen Zhou (ISYE)
Dr. Paul M. Griffin (ISYE)


This research develops a methodology for enhancing the performance of a precision computer numerically controlled (CNC) machine tool. The ability to precisely maintain the desired relative position between the cutting tool and the workpiece along the cutting trajectory dictates the dimensional accuracy of the finished part. It is important to ensure that the workpiece geometry satisfies tolerances before removing it from the machine tool, especially in manufacturing situations where accuracy drives production rather than quantity. Traditional manufacturing procedures do not catch bad parts until the post-process inspection stage, when the part has already been removed from the setup. The objective of this research is to develop a methodology that integrates pre-process calibration and process-intermittent gaging to enhance the ability of a two-axis vertical turning center to cut a circular arc trajectory. The developed methodology is straightforward and integrates the usage commercially available instrumentation. This research also identifies the capabilities of the ball bar and on-machine probe for error identification, prediction, and compensation.