Research On Precision Calibration Technology Of Large-Volume Coordinate Measuring Systems

In modern industry such as aerospace in particular, large-volume coordinate measuring systems are used more and more widely, meanwhile, the research on its calibration technology is increasingly urgent. Laser tracking system is becoming a leader in large-volume coordinate measuring systems because of its advantages such as wide measuring range, high accuracy and portable, and its calibration technology is the main object of this thesis.In this thesis research on basic theory of laser tracking system has been done,contributory factors that influence measurement accuracy of Laser Tracker has been analyzed. A method and device for calibrating the length-measuring accuracy in the whole measurement range of laser tracking system is proposed; measurement model of multi-station laser tracking system has been established, and several common algorithms for station transform have been simulated and the results proved station-transform errors that solved by weighted total least square are minimum; method of using WTLS to solve station-transform parameters first and then utilizing data fusion and Monte Carlo method to calibrate the measurement accuracy of multi-station laser tracking system is proposed.Here are the results of simulation and experiments of calibrating method proposed in this thesis: the measuring range in the simulation experiment is limited to 5m, uncertainty of length measurement, azimuth angle and elevation angle is respectively 0.0218 mm, 4.4''and2.1'',relative error of uncertainty of length measurement is 2.3%; the measuring range in the real experiments is limited to 6m, uncertainty of length measurement, azimuth angle and elevation angle is respectively 0.038 mm, 2.8'' and 2.7'',relative error of uncertainty of length measurement is 27%; the uncertainty of measurement obtained by simulation and real experiments is close to theory value and in the same number level, which verify that the method of using WTLS to solve station-transform parameters first and then utilizing data fusion and Monte Carlo method proposed in this thesis can be implied in calibrating the measurement accuracy of multi-station laser tracking system.