Deep-sea structure pose measurement's error analysis and experimental study

摘要

The relative distance and angle of two subsea structures is often determined using a deep-sea structure pose measurement system; thus, the high accuracy of pose measurement has important significance for the success of deep-sea operations. Here, we take two subsea pipelines for example to design their overall measurement schemes, the parameters of their detection methods, and the operation procedures for the deep-sea operating environments they service. We furthermore show the theoretical calculation formulas of their measurement results. The theoretical error of the transition matrix algorithm is calculated using the error propagation relations theory, and an example is used to verify the accuracy of the results calculated in this study. The study presents a segmented, least squares method for pose measurement systems, calculates the error correction coefficient, and revises the resulting function of both the relative distance and the angle. After the experimental platform is established, the measured value and the true value of two pipelines' pose parameters are contrasted in order to verify the measurement method and the error correction theory. The experimental results show that the distance error is in the range of ± 25 mm, and that the angle error is in the range of ± 0.6° within 7 m after correction. We reduce the measurement error of the pose measurement system, and verify the correctness of the theoretical. In doing so, we ensure the precision parameter for the connection between two submarine pipelines.