Research on underwater pipe nozzle pose measurement based on stereo vision

Accurate localization of the underwater pipe nozzle is important for underwater pipeline inspection robots. Based on the requirements of pipeline inspection operations, a stereo-vision-based method for measuring the pose of underwater pipe nozzles is proposed. During calibration, underwater equivalent camera parameters are used to correct images, eliminating the effects of light refraction. For the corrected images, an ellipse detection method based on arc-supported line segment detection is employed to accurately identify the pipe nozzle contours. Corresponding points are matched through row pixel matching, and the pose is calculated by fitting the contour points. Experimental results show that the method achieves high pose measurement accuracy and meets the practical requirements for underwater pipe nozzle localization.