Field ice thickness and ice velocity automatic measuring method based on variable-focus image method

Abstract

The invention relates to a field ice thickness and ice velocity automatic measuring method based on a variable-focus image method. The field ice thickness and ice velocity automatic measuring method belongs to the technical field of ocean engineering. The field ice thickness and ice velocity automatic measuring method comprises the steps of: step 1, calibrating a function K in a laboratory; step 2, and carrying out actual measurement on ice thickness and ice velocity in the field, wherein the function K which is calibrated in the laboratory is automatically invoked according to focal length information f fed back by a variable-focus high-definition camera and distance information D fed back by a distance measuring instrument when processing images, and length or displacement distance H of an object can be calculated accurately with the combination of pixel size h of the displacement distance of a sea ice fracture surface or a feature point within a certain period of time. The field ice thickness and ice velocity automatic measuring method avoids system errors made in the actual measurement process, can be used for measuring the distance between the camera and the ice surface accurately, improves the measurement precision, is high in system adaptability, simple in structure and high in reliability, can adapt to harsh offshore working conditions of high humidity and high salinity, ensures the reliable operation of the system so as to obtain complete ice thickness and ice velocity data, and provides an important basis for the safety monitoring of an offshore platform.

Description

technical field [0001] The invention belongs to the technical field of marine engineering, and relates to an automatic measurement method of field ice thickness and ice velocity, in particular to an automatic measurement method of field ice thickness and ice velocity based on a zoom image method. Background technique [0002] The oil and gas resources in the Bohai Sea are rich, but they are scattered overall. Considering the principle of maximizing benefits, most of my country's oil and gas platforms put into production in the Bohai Sea are marginal oil fields, with less steel consumption. Since the Bohai Sea is a high-latitude sea area, there are relatively serious sea ice disasters in winter, and marginal oilfields will generate relatively serious ice-induced vibrations under the impact of sea ice, which seriously threatens the safe production of platforms. Relevant studies have shown that the exciting force generated when sea ice hits the platform is mainly related to ice...

AI Technical Summary

Problems solved by technology

However, in practical applications, due to the influence of tides, the distance from the sea ice to the camera and the broken position of the sea ice actually change, and d≠f, so there is a large error in the calibration value ξ

At the same time, because the lens is far away from the sea surface, sometimes it is necessary to change the focal length f of the lens to obtain the best sea ice image information, which brings difficulties to the on-site calibration work and directly affects the field use of the method

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