Automatic Measurement Plane Size Based On Machine Vision

Dimension detection of parts is one of ordinary jobs of mechanical industry. At present, the detection of parts' dimensions is done manually, which not only increases the workers' labouring intension, but also is difficult to guarantee the quality of parts. Especially for the manual detection of form-position error, it takes much time and the precision is not high. In the recent years, with the application of machine vision in industry detection, it is a necessary trend of modern manufacture to apply computer technology to detect parts' dimensions.Based on the theory of machine vision, this paper presents a system of automatic detection of parts' form-position dimensions, which includes vidicon, image collecting clip, Personal Computer and software system. It can realize the automatic measurement of some form-position dimensions of parts. This paper is composed of three parts: image collecting, image processing and dimension measuring. Image collecting is to get images of the parts for the following image processing, the last two parts are the keystones of this paper.Image processing has three steps: pretreatment of images, edge extraction and character detection. As a key step, edge extraction affects the processing speed and precision of the whole system. By comparing the traditional methods of edge detection, this paper applies thresholding method for image segmentation and mathematical morphology for edge extraction to process the images and get continuous and single-pixel edges. This method has less calculation and high location precision.The detecting methods of straightness, parallelism, roundness and concentric degree are studied in this paper, so we need to detect beeline and circle. For the detection of beeline, based on the tactic of changed distinguishing rate, this paper applies Multi-level Hough...