Research On The Measurement Technology And Experiment Of Large Scale Structure

This dissertation is focused upon the development of a complete theoretical package in terms of the surface modeling, measure planning, data processing and error analysis of large-scale structure measurement using a FARO laser tracker system. The following works have been completed:With the aid of the principle of computational geometry, the algorithm of characteristic points selected has been conducted by controlling the maximum tolerance between the approximate curves of quintic polynomial and all the points, then the contour line was constructed by interpolating the selected points with the quintic B spline, the surface was shaped rapidly through visual basic programming.Based on the coordinate transform theory, this work develops a digitized point sets registration method, which is used to matching the frame of measurement with the reference frame.Aiming at the error evaluation on positional tolerance and the profile error, the algorithm of plane fitting was developed according to the indirect adjustment theory, and the profile error for curved surface was estimated through calculating the vector between the measuring points and the nominal model.Based on the experiment of large scale jigs detection, the process of measuring was developed with the geometric modeling, measuring planning and error analysis . Simultaneity the factors affect the measurement precision was analyzed and the measurement uncertainty was estimated.These research results have some guiding effects on the measurement of large scale structure and provide theoretical foundation of the follow up error tracing and processing improvement ,therefore the study is of great significance theoretically and practically for large-scale parts agile manufacturing.