Aperture and pitch measuring device and measuring method for large-sized tube sheet

Abstract

Provided in the invention is an aperture and pitch measuring device and measuring method for a large-sized tube sheet. The measuring device comprises a two-dimensional translation mechanism, a measuring head mechanism, a controller and a computer. The two-dimensional translation mechanism moves according to a path planned in advance; the measuring head mechanism completes image collection and uploads the image to the computer; and the computer processes the image information to obtain the aperture of a tube sheet and pitch data of adjacent holes, and then displays a measuring result and completes storage and printing outputting of a detection report. In addition, the measuring method includes: step one, carrying out identification and separation of a target hole; step two, extracting the edge of the target hole by using a sub-pixel edge extraction method and carrying out fitting of the centers of all holes by using hole edges; step three, on the basis of plane projection transformationand polar line constraint, carrying out target hole matching; step four, carrying out local plane determination; step five, carrying out three-dimensional coordinate calculation of hole edges; ad step six, selecting and determining an aperture and a pitch preferably by using a redundant measurement result. The aperture and pitch measuring device and measuring method have advantages of high reliability and high measurement result accuracy.

Description

technical field [0001] The invention belongs to the field of machine vision measurement, and relates to a large-size tube plate aperture and pitch measurement device and measurement method. Background technique [0002] The size inspection of mechanical parts is one of the important links in the field of mechanical processing, and its inspection results will directly affect the quality of the product, and even play a decisive role in the quality of subsequent reprocessing and assembly. Traditional mechanical parts size inspection tools mainly include calipers, gauges, universal tool microscopes, profilers, etc. At present, most manufacturers still use manual inspection to measure the size of industrial parts. Manual inspection has disadvantages such as high labor intensity, high labor cost, slow inspection speed, and strong subjectivity, which not only affects the work efficiency of the production line, but also wastes a lot of labor resources. The working status of inspect...

AI Technical Summary

Problems solved by technology

At present, the commonly used method for tube sheet inspection is the manual plug gauge method, that is, to measure one by one by manpower using plug gauges, and it takes an average of 4 days to detect a large tube sheet

The manual plugging method has high labor intensity, high labor cost, low degree of automation, and low efficiency. It is also easily affected by human subjective factors, and it is prone to missed and wrong detections.

Measuring instruments for aperture and pitch measurement include three-coordinate and image-based aperture measuring instruments. Although the three-coordinate is high in accuracy, it is costly, complicated to operate, and low in efficiency; the efficiency of image-based aperture measuring instruments has been significantly improved, but Due to the limitation of the measurement range, these two types of instruments cannot measure parts with large dimensions.

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