Study On The Wave Following Scanning Detection System For Underwater Shallow Layer

In underwater topographic surveys,due to the impact of draughts on large survey ships,underwater topographic surveys in shallow water areas such as near shore,shoals,islands,and reefs are difficult and difficult to cover all monitored waters,and the multi-beam detection equipment has high transmit power Leading to high energy consumption of traditional surveying vessels.Relatively speaking,small unmanned surveying ships cannot be equipped with large ultrasonic transducer array detection equipment due to limitations in size and energy consumption,and cannot be beamformed,but they can be equipped with a miniaturized singlebeam detection system for shallow water.Underwater terrain measurement of the area.In this paper,the research method of wave period and system sounding extreme value is given for the underwater shallow wave unmanned detection system independently developed by the laboratory;the compensation correction algorithm based on the system is studied to improve the system measurement accuracy;the research data is automatic Processing algorithms make the system more intelligent and better adapt to the actual working environment;a high-precision reconstruction method of underwater terrain based on the system is proposed;and the feasibility of the method is verified by simulation experiments.The detection field has certain technical reference value and engineering application significance.The main work and innovations of this thesis are as follows:(1)Aiming at the requirement of index measurement of system sounding extreme value,this thesis proposes to use the change law of hull attitude information to measure the wave period of the detection water area,and to calculate the system sounding extreme value under wave effect according to the wave period.The attitude information is converted into the angle between the plane of the ultrasonic transducer and the horizontal plane,and then the Fourier transform is used to analyze the change rule of the angle between the one-dimensional.For the lack of detection accuracy of the system,the state of the hull under the wave is used to propose A comprehensive compensation correction algorithm based on the ship speed delay effect,based on the attitude and position information of the hull at the time of transmission and reception,the angle between the transducer plane and the horizontal plane,through geometric calculations to compensate for the detection distance and detection point coordinates.(2)Based on the small ultrasonic transducer array developed by the laboratory,the detection mode of separation of transmission and reception and multiple transmission and reception is designed,so that multiple receiving transducers form a common projection area under the water that can receive the reflected signal at the same time,and according to the area Screening the detection points can reduce the measurement error caused by the system beam angle effect.In the aspect of automatic data processing,research on automatic data filtering and automatic data processing methods based on the system.(3)Aiming at the low accuracy of the underwater three-dimensional terrain of the underwater shallow wave scanning detection system,a high-precision reconstruction method of underwater terrain based on this system is proposed.By integrating and fusing multiple sounding data,and aiming at the fusion data The distribution rule of sample points is designed based on the surface interpolation method of sample point distribution,which makes the reconstructed 3D terrain more accurate.