视觉自动化检测原理:精确检测产品裂纹与划痕

发布时间:

2023-02-10 11:26

  在机器视觉自动检测技术中最大的技术调整就是检测物品表面的裂纹、划痕、变色、烧蚀等表面缺陷。难点在于形状不规则,深度与光线对比度低,经常受到产品表面自然纹理或图案的干扰。
  In the machine vision automatic inspection technology, the biggest technical adjustment is to detect the surface defects such as cracks, scratches, discoloration, ablation and so on. The difficulty lies in the irregular shape, low depth and light contrast, which is often disturbed by the natural texture or pattern of the product surface.
  因此,表面缺陷的检测需要高精度的照明、摄像机分辨率、被检测部件与摄像机的相对位置以及复杂的机器视觉自动检测技术。
  Therefore, the detection of surface defects requires high-precision lighting, camera resolution, the relative position between the detected parts and the camera, as well as complex machine vision automatic detection technology.
视觉自动检测技术
  光照是产品表面缺陷检测中一个极其重要的因素,因为表面缺陷通常具有低对比度的特点,使用正确的光照可以将其与背景分离。对于平面凸面缺陷,可以使用低角度照明来“照亮”凸面部分的边缘。
  Illumination is an extremely important factor in the detection of surface defects of products, because surface defects usually have the characteristics of low contrast and can be separated from the background by using the correct illumination. For planar convex defects, you can use low angle lighting to "illuminate" the edges of convex parts.
 
  水平检测功能(玻璃盘)
  水平螺牙检测功能
  头部检测功能(分度盘)
  漫射光可用于检测光滑缺陷或曲面缺陷。在采集的图像中,裂纹或划痕应至少覆盖三个或更多像素。在某些情况下,多个高分辨率相机或单个相机用于多个拍摄,或者更常见的是,使用1K到16K的线扫描相机以指定的分辨率检测零件的整个表面,以满足用户的精度要求。
  Diffuse light can be used to detect smooth defects or surface defects. Cracks or scratches should cover at least three or more pixels in the captured image. In some cases, multiple high-resolution cameras or a single camera are used for multiple shots, or more commonly, a line scan camera from 1K to 16K is used to detect the entire surface of the part at a specified resolution to meet the user's accuracy requirements.
  为了利用机器视觉自动检测技术检测产品的裂纹和划痕,首先要了解产品表面缺陷是如何产生的,并在图像中清晰地分类这些缺陷可能的形状。例如,粉末金属零件材料较薄时,在烧结过程中会出现裂纹。基于经验知识,可以将机器视觉自动检测技术集中到缺陷产生区域,明确检测方向,有助于提高缺陷检测的可靠性。
  In order to detect the cracks and scratches of products by machine vision automatic detection technology, it is necessary to understand how the surface defects of products are generated, and clearly classify the possible shapes of these defects in the image. For example, when powder metal parts are thin, cracks will appear during sintering. Based on the experience knowledge, the machine vision automatic detection technology can be concentrated in the defect producing area, and the detection direction is clear, which is helpful to improve the reliability of defect detection.
  在人工检测过程中,通过直觉和经验可以预测缺陷的形状。例如,划痕通常表现为一系列的直线或略微弯曲的线,这些线往往潜意识地通过心理上的“格式塔”能力连接成一条线。在机器视觉自动检测技术中,这种“格式塔”能力可以用视觉微积分粗略地表现出来。
  In the process of manual inspection, the shape of defects can be predicted by intuition and experience. For example, scratches usually appear as a series of straight lines or slightly curved lines, which are often subconsciously connected into a line by a psychological Gestalt ability. In machine vision automatic detection technology, this "Gestalt" ability can be roughly expressed by visual calculus.
  在高难度测试过程中,测试人员可能会有不同的意见——哪是擦伤?或者只是碰巧形成一条线的亮点?这说明需要考虑缺陷检测的可靠性。如果表面缺陷清晰,缺陷成分清晰,机器视觉自动检测技术的检测结果的一致性和可靠性高于人工视觉检测。
  In the course of a difficult test, testers may have different opinions - which is a scratch? Or is it just a bright spot that happens to form a line? This shows that the reliability of defect detection needs to be considered. If the surface defects are clear and the defect components are clear, the consistency and reliability of the detection results of machine vision automatic detection technology are higher than that of artificial vision inspection.
  为了检测产品表面上的小缺陷,确保零件表面始终处于相机的焦点区域是非常重要的。视觉自动检测技术用于准确检测产品的裂纹和划痕,有关机器视觉自动检测技术的更多信息,请访问山东红宝自动化有限公司官方网站:http://www.hongbaozdh.com
  In order to detect small defects on the product surface, it is very important to ensure that the part surface is always in the focus area of the camera. Visual automatic detection technology is used to accurately detect cracks and scratches on products. For more information about machine vision automatic detection technology, please visit the official website of Shandong Hongbao Automation Co., Ltd.

视觉自动检测技术