Online detection method for circular plate casting based on machine vision

Abstract

The invention discloses an online detection method for a circular plate casting based on machine vision, and the method comprises the steps: obtaining the front and back images of a circular plate casting sample through collecting the image of the circular plate casting sample, and performing the preprocessing of the images; detecting the size of the sample according to the collected sample image,performing the preliminary discrimination of defects, and performing the next detection; performing the amplification of a gap through the image processing, extracting the coordinates, and achievingthe detection marking of the sample gap; performing the detection of the rag defects of the sample according to the comparison between the degree of deviation of the edge from the reference and a setthreshold value; and finally completing the discrimination of whether the sample is qualified or not. The method can achieve the real-time quick recognition of the gap and rags of the circular plate casting, and is suitable for a high-speed online detection system.

Description

technical field [0001] The invention belongs to the field of machine vision, and in particular relates to an online detection method for brake disc castings based on machine vision. Background technique [0002] In the production process of castings, due to various reasons, it is difficult to avoid defects such as flashes, burrs, and defects on the outer contour of castings. These defects seriously affect the surface quality and physical and mechanical properties of products; in terms of dimensional accuracy, castings may appear Insufficient pouring, thin-wall deformation, etc., lead to unqualified overall size and weight of castings. [0003] At present, the quality inspection of casting factories mostly adopts online manual inspection or offline sampling inspection. Manual online detection has a strong dependence on the working ability and fatigue degree of workers, and the accuracy cannot be guaranteed. Moreover, the labor cost of manual inspection occupies a considerab...

AI Technical Summary

Problems solved by technology

[0006] (2) The brake disc casting is a mechanical part with circular features, and its outer edge has defects such as gaps, seams and flash burrs, which have a certain impact on the circle fitting of the inner and outer diameters

The previous methods used to detect circles mainly include the geometric center method, the least square method, and the circle Hough transform. The geometric center method has a simple calculation process, but requires that the known points be evenly distributed, or used when the accuracy is not high; the minimum The square method is easily affected by the missing part of the actual object boundary or curve, image noise, and fitting deviation; while the traditional Hough circle detection has strong noise resistance and high precision, its main disadvantage is that the calculation and storage requirements of the algorithm increase with the curve dimension. The number increases exponentially, not suitable for high-speed online detection system

[0007] (3) The shape of casting surface defects is relatively complex, and it is difficult to detect

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