Method for Detecting Obstacles in Reservoir Culverts Based on Circular Structured Light
J-N. Chen, S-L. Cai, J. Wang, X-F. Wu and C-N Yu
To obtain position and size information about obstacles inside a reservoir culvert, and to make it convenient for pipeline robots to adjust their postures in real time to continue moving, we propose an obstacle detection method based on circular structured light suitable for the characteristics of reservoir culverts. Using a method of calibrating the circular structured light of a planar target, the equation of the circular structured light surface in the camera coordinate system is obtained. According to the measurement principle of structured light, the inner wall of the reservoir culvert is scanned by laser to obtain three-dimensional (3-D) information on the surface, and the position and size of the obstacles within the culvert are determined. The results show that the calibration error of circular structured light is less than 0.1 mm, which fulfils the requirements of obstacle detection in reservoir culverts. The obstacle detection method based on circular structured light can simultaneously detect the spatial position and size of obstacles inside the reservoir culvert, and the detection error rate is less than 5%, which is generally lower than that of other obstacle detection methods. Our results demonstrate that the proposed method can be applied to the detection of obstacles inside reservoir culverts.
Keywords: Laser projector, reservoir, obstacles, circular structured light, spatial position coordinates, circumferential size, radial size