Research on Error Dynamic Amendment Method and Its Application in High-Accuracy Thickness Measurement System

The laser displacement sensor, as a non-contact thickness gauge, is extensively used in measuring the thickness of composite board. When dynamic scanning method is introduced, the high accuracy laser displacement sensor cannot give ideal measurement results for the reason of complex working condition and various measured body. In order to get accurate measurement result, this paper proposes an error dynamic amendment method and uses it in the online dynamic measurement system of clean surface composite board. The proposed error dynamic amendment method is based on the dynamic measurement of newly installed calibrated block and data automatic amendment using computer. A temperature compensation block whose character is same to measured board is installed in the position of "U" type bracket; the online measurement system can specify the composite board from the calibration block by judging the electrical signal generated by programmer; in each distance of run, the industry personal computer uses the difference between the calibrated compensation block and measured board to amend the dynamic error, the signal of board thickness, temperature compensation block thickness and bracket position is put into remote system. The thickness monitoring system is developed on the platform of Labview, and it has the function of parameter set-up, bar graph displaying, error alarming and marking, data analysis and management, it fulfills the integration of online dynamic precision measurement, condition monitoring and data management, the precision reaches to 0.01mm after applying error dynamic amendment method. The online condition monitoring and measuring system using error dynamic amendment method has the merits of real-time data acquisition, reliable system operation, exceeded error alarming, convenient module combination, credible monitoring and measuring result and friendly man-machine interface, it has been used in thickness measurement of composite board for several months, th- - e percentage of pass of board and productive efficiency is enhanced