Computer-vision-based underwater laser datum line measuring system

Abstract

The invention, which belongs to the underwater special measurement field, discloses a computer-vision-based underwater laser datum line measuring system for measuring a relative position parameter for underwater structure installation and assisting in underwater engineering building. According to the measuring system, a laser ray generated by a high-power laser is used as a preset datum line and a measuring scale, thereby providing an image feature for computer vision software measurement. An underwater camera carried by the system obtains an underwater on-the-spot picture; the computer vision software extracts an image feature; a relative distance between an underwater structure and a preset position is obtained by using a built-in algorithm; and a difference of elevation or a tooth malocclusion parameter between two adjacent regular structures is measured by extracting other features of the picture. Therefore, a plane attitude or relative position of a structure can be reflected; and an objective of assisting in precise installation of underwater work can be achieved.

Description

technical field [0001] The invention belongs to the technical fields of computer vision and underwater engineering, and in particular relates to computer vision recognition and measurement of underwater structures. Background technique [0002] Gravity wharf is a type of wharf structure that is widely distributed and widely used in my country. The main forms are block structure and caisson structure. Among them, the block-structured wharf generally uses prefabricated large concrete blocks as the basic components, and the blocks are prefabricated in the prefabrication yard, and then transported to the site for installation. The installation accuracy and efficiency of the blocks directly affect the quality and progress of the entire block dock construction. [0003] At present, in the construction of gravity block wharf, there are several traditional block installation measurement and positioning methods: underwater datum line method, front reference object control method, wa...

AI Technical Summary

Problems solved by technology

The first four methods are all physical contact methods, which require a large number of personnel and ship machinery, which requires a large investment and low efficiency, and the surface hoisting commander can only obtain the position information of the underwater block through the underwater intercom and the diver’s voice communication , the construction quality cannot be effectively supervised

On the basis of this demand, a fifth method has been further developed - the measuring frame positioning method, that is, an extension frame (rod) above the water surface is set on each corner of the block, and a signal transmitter is installed on the top of the frame, and a water surface receiver The plane position of the underwater block is determined by receiving position signals from different rod heads, but this method has strong limitations-it is only suitable for shallow water operations below 5 meters in depth. For the installation of base blocks with deeper water depths, then still need to use the above positioning method

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