First, calibration
In high-precision measurement is generally required calibration, mainly divided into optical distortion calibration, projection distortion calibration, object-like space calibration, etc. , but the general calibration algorithm is based on plane calibration, for not plane is difficult to solve with calibration algorithm. There are also special measurement processes that do not use calibration boards, so calibration algorithms may not solve all problems.
Second, the measurement accuracy of the software
Measurement accuracy is generally 1/2-1/4 pixels, because the measurement software is too small, the less feature point information extracted from the image.
Through the above 5 problems can be seen in the machine vision system design will appear a lot of factors interference, so we need to constantly improve and upgrade technology to avoid these inevitable problems, but also believe that technology innovation, many problems can not be solved.
Third, the speed at which an object travels
During image acquisition, the accuracy of image blur depends on the speed of motion of the object and the exposure time of the camera, so the speed of motion of the object is likely to cause the image imaging to blur, in addition to other equipment (industrial cameras, industrial lenses, light sources, etc.) will indirectly affect detection.
Fourth, the consistency of the position of the work piece
Insistency in the position of the work piece is a particularly important concern leading to measurement detection. Industrial production line whether online or offline detection, machine vision system in obtaining product picture information need to ensure that the product arrived at the same location, otherwise there will be inaccurate positioning, measurement tools appear in an inaccurate position, resulting in a deviation in the measurement results, for the product's passability is difficult to control.
Fifth, the stability of lighting
In machine vision applications, light stability affects the accuracy of the measurement most, as the measurement results can vary by 1 to 2 pixels as long as there is a small change in light. The main reason is that the instability of lighting will affect the image acquisition edge position changes, so in the machine vision system design to eliminate the impact of ambient light to a minimum, while ensuring the stability of the supporting active light source.
It is not difficult to see through the above machine vision system design will appear a lot of factors interference, so we need to constantly improve and upgrade technology to avoid these inevitable problems