Overview of Fundamentals of Machine Vision Application Principles
Application of Machine Vision
The application of machine vision mainly includes two aspects: detection and robot vision:1. Testing: It can also be divided into high-precision quantitative testing (such as cell classification in micrographs, size and position measurement of mechanical components) and qualitative or semi quantitative testing without measuring tools (such as product appearance inspection, component identification and positioning on assembly lines, defect detection, and assembly completeness detection).2. Robot vision: used to guide the robot's operations and actions over a large range, such as picking workpieces from the disorderly pile of workpieces sent out by the hopper and placing them in a certain direction on the conveyor belt or other equipment (i.e. hopper picking problem). As for small-scale operations and actions, tactile sensing technology is also needed.In terms of industry applications, there are mainly industries such as pharmaceuticals, packaging, electronics, automotive manufacturing, semiconductors, textiles, tobacco, transportation, logistics, etc. Replacing manual labor with machine vision technology can provide production efficiency and product quality. For example, in the logistics industry, machine vision technology can be used for sorting and classification of express delivery, which will not result in most express delivery companies manually sorting, reducing the damage rate of items, improving sorting efficiency, and reducing manual labor.Machine Vision FeaturesThe camera's photography speed automatically matches the speed of the object being measured, capturing the ideal image;2. The size range of the parts is 2.4mm to 12mm, and the thickness can vary;3. The system selects workpieces of different sizes according to the operator, calls the corresponding visual program for size detection, and outputs the results;4. For parts of different sizes, sorting devices and conveying devices can accurately adjust the width of the material channel, allowing the parts to move on a fixed path and undergo visual inspection;5. Machine vision system resolution reaches 2448 × 2048, the dynamic detection accuracy can reach 0.02mm;6. The missed inspection rate of waste products is 0;7. This system can monitor the detection process by displaying images, and can also dynamically view the detection results through the detection data displayed on the interface;8. It has the function of timely and accurate sending out rejection control signals for incorrect workpieces and eliminating waste products;9. The system can self check whether the status of its main devices is normal, equipped with status indicator lights; At the same time, it is possible to set different operation permissions for system maintenance personnel and users;Real time display of detection screen, Chinese interface, capable of browsing images of non-conforming products several times, with the function of storing and real-time viewing incorrect workpiece images;11. Can generate error result information files, including corresponding error images, and be able to print and output.Composition of Machine Vision SystemThe literal meaning of machine vision system can be seen as mainly divided into three parts: machine, vision, and system.Machines are responsible for the movement and control of machinery; Vision is achieved through light sources, industrial lenses, industrial cameras, image acquisition cards, etc; A system mainly refers to software, which can also be understood as a complete set of machine vision equipment.Image acquisition: light source, lens, camera, acquisition card, mechanical platformImage processing and analysis: industrial control host, image processing and analysis software, and graphical interaction interface.Judgment execution: telex unit, mechanical unitInput Device for Machine VisionIncluding: imaging equipment - scene detection imagingDigital device - converts the analog signal output by the imaging device into 2D/3D digital imagesCommonly used imaging equipment: CCD color/black and white cameras, digital scanners, ultrasound imaging detectors, CT imaging equipment, infrared imaging systems, laser imaging systems, computational imaging systems, etcThe optical band used by the observation system can range from visible light, infrared, X-ray, microwave, ultrasound to γ Radiation.Observation objects: stationary, moving, planar, three-dimensional high-definitionThe working principle of machine visionThe machine vision detection system uses a CCD camera to convert the detected target into an image signal, which is transmitted to a dedicated image processing system. Based on pixel distribution, brightness, color, and other information, it is converted into a digital signal, The image processing system performs various operations on these signals to extract the features of the target, such as area and quantity, and then finds the degree based on the preset allowable degree and other conditions, including size, angle, number, qualified/unqualified grid, will have or not, to achieve automatic recognition function.The maximum features of machine vision systemsBy using various knowledge such as feature models, imaging models, object models, and relationships between objects, automatic operations should be carried out at all stages of vision as much as possible. The system should use knowledge that can be clearly represented, which will make the system more adaptable and robust, and can also solve difficult problems in machine vision.