AOI detection, also known as automatic optical detection technology, also known as machine vision detection technology or automatic vision detection, is based on the optical principle to detect the common defects in the welding production. When automatic detection, the machine automatically scans PCB through camera.
Collect images, compare the tested solder joints with the qualified parameters in the database, check the defects on the PCB after image processing, and display / mark the defects through the display or automatic mark for repair by the maintenance personnel.
AOI system is a simple optical imaging and processing system which is composed of camera, lens, light source, computer and other general devices. Under the illumination of light source, the camera is used to image directly, and then the detection is realized by computer processing. The advantages of this simple system are low cost, easy integration and relatively low technical threshold. It can replace manual detection in the manufacturing process and meet the requirements of most occasions.
According to different imaging methods, AOI can be divided into three-dimensional (3D) AOI and two-dimensional (2D) AOI. The three-dimensional AOI is mainly used for measuring geometric parameters of object shape, grouping parts, positioning, identification, robot guidance and other occasions; the two-dimensional AOI is mainly used for product appearance (color, defect, etc.) detection, different objects or appearance classification, detection and classification of good and bad products and other occasions.
However, due to the mutual restriction of field of view and resolution (or accuracy), or the special requirements of production beat on detection speed, the AOI system composed of single camera is sometimes not competent for the visual detection of large-scale or complex structure objects. Therefore, it may need to have multiple basic units integrated together to work together to complete the high difficulty detection task. That is to say, a multi-sensor imaging, high-speed distributed processing AOI system integration architecture is adopted.