Dynamic coordinate measuring machine error analysis and improvement strategies

modern mechanical systems such as machine tools, mechanical manipulators, and Coordinate Measuring Machines (CMMs) are supported by motion controllers to achieve the desired repeatability and tolerance remthernents. Various techniques have been applied to improve the machine performance such as calibration, geometric error compensation, and thermal error compensation. For CMMs, repeatability, precision, and accuracy are essential and efforts are continuously heing made to improve the machine performance.;A retrofit open architecture system that provides following improvement strategies is proposed and implemented: (1) Continuous geometric error compensation and parallel drive capability were developed and integrated to the CMM system to support new sensors and to improve the dynamic behaviour of the machine. Cross-coupling control was used to link the master and slave control loops to provide improved coordinated motion, The extended slave compensation corrects the remaining angular yaw error. (2) The dynamic angular errors were detected by using a pair of 2 dimensional (2-D) lateral effect photodiodes, also known as Position Sensitive Detectors (PSDs), and laser source devices. The system is integrated to the CMM controller to provide real time measurement. The angular errors can he used in the geometric error compensation function to correct the coordinates of the CMM.;The objective of this thesis is to analyze the dynamic error effects on CMMs, then propose methods that can itnprove the overall measuring performance for the inspection system. Finally the proposed methods are implemented and tested to validate the improvements.