A method of underwater terrain matching based on the histogram of edge corners of sonar images

Abstract

The invention relates to the field of digital image processing, in particular to an underwater terrain matching method based on a sonar image edge corner histogram applied to an underwater submersible navigation system. The present invention includes: (1) normalizing and interpolating the original multi-beam data, and converting the depth value to the range of 0-255 through linear transformation; (2) projecting the three-dimensional model onto the XY plane, if The gray value of each projection point is set to the height value of the point in the 3D model, then the projection is the gray image of the underwater terrain; (3) traverse each gray level, and count the number of pixels under the same gray level , form a grayscale histogram, and obtain the total number of pixels at each grayscale. The invention uses the histogram theory to analyze each gray level of the image respectively, and overcomes the disadvantage of poor resolution of the traditional gray histogram. Using the edge corner histogram as the image feature, the position of the underwater vehicle is located according to the similarity calculation results. In the presence of noise, orientation errors and scale changes, the reliability of the results can still be maintained.

Description

technical field [0001] The invention relates to the field of digital image processing, in particular to an underwater terrain matching method based on a sonar image edge corner histogram applied to an underwater submersible navigation system. Background technique [0002] In recent years, the world's scientific and technological powers are focusing on the research and development of underwater unmanned submersible technology, and plan to use it as the main tool for exploring and utilizing the ocean. As far as the current research focus is concerned, the underwater navigation technology of submersibles is one of the most important technical challenges in this field. [0003] There are two main types of commonly used underwater navigation and positioning methods: one is the navigation method based on acoustics, and the other is the navigation method based on dead reckoning. Although both can realize the positioning function, due to their inherent defects, such as the cumulati...

AI Technical Summary

Problems solved by technology

Although both can realize the positioning function, due to their inherent defects, such as the cumulative error increases with time, the use area is small and the maintenance cost is expensive, etc., they are not suitable for independently completing long-term and long-distance underwater positioning tasks. Instead, it needs to be periodically corrected by assisted navigation technology

Images