Research on color space-time coded structured light for molded line evaluation in industrial site

The key for coded structured light 3D measurement technology in industrial site is to improve measurement accuracy, and sampling density and measurement speed are taken into account simultaneously. A color space-time encoding and decoding method for structured light system and its related technologies are proposed. Firstly, RGB stripes are used to encode, that have the minimal interaction, for improving anti-interference capability. Secondly, color transition between stripes ordered by Eulerian path is used to encode instead of own color of stripes, then four times more sampling density can be acquired in the same measured space. Thirdly, sub-pixel stripe edge and center detecting algorithms based on color component are proposed to improve measurement accuracy. Fourthly, only two encoding patterns ensure measurement speed. Measurement system was established according to mathematic model. Experimental results show that error of measured standard plane is less than 0.06 mm, and reconstructed complex surface has same visual effect as real surface. Finally, the method for turbine blade molded lines evaluation was explored.