What is visual inspection system? Most of our applications of visual inspection system only stay in the aspect of product appearance defect detection. In fact, the visual inspection system technology also includes the use of industrial cameras to complete product identification, measurement, positioning and other functions.
A typical PC based industrial machine vision inspection system consists of five parts: light source, lens, camera (including CCD camera and COMS camera), acquisition card and visual processing system. Each part cooperates with each other to complete the testing requirements.
Light source is an important factor that affects the input of machine vision inspection system. Light source directly affects image quality and effect. For each specific application example, the corresponding light source and lighting mode should be selected to achieve the best effect. Lighting methods can be divided into light field lighting and dark field lighting.
The function of the lens is to image the workpiece onto the photosensitive chip of the camera. The lens is mainly divided into CCT lens and telecentric lens.
The camera converts optical signals into electrical signals. The early cameras did not have the function of converting analog electrical signals into digital electrical signals, so they were called analog cameras. Generally, the analog camera needs to be used together with the image acquisition card, which transfers the electrical signal of the analog camera into a digital signal and transmits it to the computer.
In recent years, the digital camera of machine vision inspection system has the function of analog conversion and follows certain communication protocol, so it can directly transmit the collected image signal to the camera. This kind of camera is called digital camera, which has become the mainstream camera of machine vision system.
Visual processing system includes hardware and software. According to the different hardware, it is divided into intelligent camera and PC based vision system. The core technology of the software is image processing algorithm, which includes image enhancement, image segmentation, feature extraction, image recognition and understanding.
Through image processing and analysis, the machine vision inspection system can judge the product quality and size measurement, and transmit the result signal to the corresponding hardware for display or execution.