Large The Workpiece Curvature Of The Precision Measurement

Measurement for curvature of workpiece is an important topic in geometry measurement,it has been widely applicated in parts manufacturing,quality audit and deformation detection. In recent years, with the implementation of four trillion plan for boosting the economy, large-scale projects increased rapidly, so for the large curved parts, and the measurement for large workpiece curvature is being payed more and more attention to.This paper analyzes the current reasurch status of large parts curvature, designs and demonstrates the overall measuring program, proposes the method of using optical bar code positioning to measure the discrete points on the large parts precisely, builts a mathematica model for this kind of measurement, analyzes many methods for plane circle fitting and chooses the least-squares for this project. What's more, this paper discusses the deviation relationship for circle radius with the accuracy of measurement and the configuration of the measuring points, and verficates the accuracy of the bar code positioning system with experiments. With Matlab simulation experiments, we got the relationship for the number of measuring with the average value and the variance of the fitting radius, and explored the suitable measuring points to obtain that ensure the accuracy of measurement while minimize the amount of project work, which can give an important basis to improve the efficiency of this kind of project.In addition, this paper didn't have the actual measurement because that the using side didn't sign the formal agreement yet, but it has analyed the engineering problems may be emerged in the future, which has made a certain foundation for the engineer practice.