High precision system calibration is the premise and foundation for precision measurement and detection of machine vision system, and the application of calibration plate can improve the accuracy index of measurement system. The so-called calibration plate is a flat plate with a fixed spacing pattern array, also known as a calibration template. The geometric model of the camera can be obtained through the camera shooting calibration plate and the calculation of the calibration algorithm, so as to obtain high-precision measurement and reconstruction results.
According to different application requirements, the types of calibration boards are diversified. What are the types of calibration boards? What are the characteristics of each type of calibration board?
1. Ceramic calibration plate
The reflective rate of the calibration plate made of ceramic materials can be reduced to 80%, which has excellent characteristics of high temperature resistance, wear resistance, chemical corrosion resistance, and low density. Therefore, both the whiteness and glossiness of the optical performance are very good. Therefore, in terms of price, ceramic materials are far more expensive than optical glass materials, but the accuracy of the calibration plate made of ceramic materials is not as good as that of optical glass materials in terms of the accuracy of the calibration plate, This is the lack of ceramic calibration plates.
AFT-MCT-SR series high-precision grid ceramic calibration plate The standard plate with ceramic substrate has the characteristics of small thermal expansion coefficient, high strength, high hardness, good wear resistance, low thermal conductivity, good acid and alkaline resistance, and its good surface diffuse reflection treatment solves the problem of reflective glass calibration plate in the case of front light source in the application process, It can better identify the details of the calibration plate pattern to achieve higher calibration accuracy and measurement accuracy. It is a special high-precision calibration tool developed for colleges and universities, research institutions and machine vision integrators. Through the calibration software, the camera calibration result data can be easily obtained.
2. Optical glass calibration plate
The calibration plate made of optical glass is the most commonly used one. The chemical property of the calibration plate made of optical glass is very stable, and the accuracy is the best. The material is free of impurities and bubbles. It is the best material for high-precision calibration plates, and the price is not expensive. The refractive index of the calibration plate is 1.6x10 minus 6 power. Its disadvantage is that it is a little transparent, reflective, and easy to break.
AFT-MCT-HC series high-precision Halcon calibration plate is a calibration plate with high-performance glass substrate, which can be widely used in the transmission visual measurement system. It has the characteristics of small thermal expansion coefficient, high accuracy, high hardness, good corrosion resistance, etc.
3. Calibration plate made of matte material
Matte is relative to polishing, that is, non bright surface. It can avoid light pollution and is easy to maintain. The matte surface is a little hairy, like the surface of frosted glass. Reflected light is diffuse reflection, no glare, not dazzling, giving people a sense of stability and elegance, bright light makes the surface smooth and clean, reflective light mirror reflection, glare, giving people a bright and gorgeous feeling.
4. Metal calibration plate
The biggest advantage of this calibration plate is that it is resistant to falling and durable, but its accuracy is slightly inferior. The AFT-MCT-OV series high-precision OpenCV metal substrate calibration plate is mainly aimed at the calibration scheme of the large field of view visual measurement system. It uses high-precision processing technology to process test standard drawings on metal materials with low thermal expansion coefficient to meet customers' needs for large field of view calibration and measurement.
