Classification of Vision Sensor Technology
1) Passive Vision
Passive vision usually uses natural light or welding arc light as the light source, which can directly obtain the image of the welding area, and obtain a large amount of information. However, strong noise interference, such as smoke and arc spatter, brings great challenges to the later image processing. However, the acquired information has good synchronization and no hysteresis, so it can be used to collect molten pool images to obtain the relationship between molten pool characteristics, welding parameters, and welding quality, so that the welding process has the ability to adjust in real time.
2) Active vision
Active vision usually uses structured light as the measurement light source, which is projected onto the surface of the measurement object, and the CCD camera captures and analyzes the surface image of the object to obtain the geometric structure characteristics of the workpiece. According to the different light sources used for measurement, the active vision method can be divided into laser method measurement and structured light method measurement. The laser method uses laser as the scanning light source, and the structured light method uses structured light such as stripes or speckles as the scanning light source.