Underwater Large Tonnage Shipwreck Attitude Detection System

Large-scale ship is the current trend of marine transport,so to enhance the overall salvage ability of large-tonnage wrecks is extremely important.In order to ensure that the shipwreck can be quickly and efficiently recovered,the attitude detection and damage observation of the sunken ship are an important prerequisite for formulating the salvage plan.Therefore,the rapid and accurate determination of the shipwreck attitude and degree of damage using modem means of measurement is an important data guarantee to ensure the success rate of salvage.It is also an urgent task facing the salvage system.The subject is from the Ministry of Transport construction science and technology project "large-tonnage wrecks overall salvage detection,flotation technology and equipment." As an important part of the project,this project is mainly responsible for:realizing the three-dimensional modeling of the underwater appearance of the wreck before salvage,and providing technical support for the development of the salvage plan.The main contents of this paper include:Designing and constructing a set of large-tonnage wreck attitude and damage detection system,researching on the method of generating 3D point cloud model of wreck,so as to realize multi-directional 3D observed function.The detection system uses three-dimensional sonar to collect the surface information of the wreck.The underwater attitude instrument is used to measure the pitch,roll angle and azimuth of the detection system in real time.The system is combined with the ultra-short baseline positioning system and GPS to locate the system in real time and use the on-board attitude instrument to calibrate the positioning data.The shipwreck surface sonar data is used to calculate the local coordinates of the shipwreck,and the rotation matrix is constructed based on the attitude data and the positioning data of the underwater system.Through the coordinate transformation Way to reconstruct the 3D point cloud model of underwater wrecks.In order to verify the reliability of the detection method and the effectiveness of the point cloud generation algorithm,two different kinds of 3D sonar were used to perform underwater target detection experiments in the laboratory pool and the harbor basin,and the three-dimensional Reconstruction of point cloud model.