Research On Key Techniques Of Measurement System Base On Machine Vision

Machine vision inspection technique is a new technique based on computer vision theory. Characterized by its high precision, fast speed, contactless measurement, good flexibility, and high level of automation and intelligence, it well meets the inspection requirements of modern manufacturing industry. The precise servo system with sensors based 3D vision measurement system can conduct automatic on-line inspection of the dimension and form and position tolerance of large workpieces, thus showing great prosperity and potentiality in industrial inspection.This article revolves the development of "the large-scale, three dimensions, and digitized measurement system for modern ship manufacture", and did a deep research to several key problems of the machine vision inspection system.The main contents of the dissertation are as follows:1. Comprehensive expatiation was made on the multi-sensor based flexible on-line 3D coordinates measurement system about its principle, system composing and its applications, simultaneously gives the structure of this article and its content arrangement.2. Summarize the methods of image processing in the machine vision inspection technique.3. Go deep into the extraction technology of stripe center of line structure light, which is the key problem of the vision inspection towards line structure light. With the summarize of exist methods, proposed the curve fitting method with auto-adapted window, this method has the very strong robustness.4. Aim at characteristics of the large-scale structure of steel: measuring range is wide, but the structure of cross section is relatively simple. bring forward a new scan strategy to the key points of the workpiece section, this method solved some problems such as time of scan is too long and the image data is too large., improve the efficiency of inspect system, settle the difficult problem of applications in engineering. At the same time, considering the structure characteristic of the inspect system, with the original three dimensional data splicing method, developed new three dimensional data splicing method based on moved coordinate, this method settle the three dimensional data splicing problem took place in using little vision sensor to inspect the large-scale object, and the adaptability of the method is validated by experiments.