| Submarine pipeline is an important part of the offshore oil and gas exploitation equipment,due to the impact of the longtime current erode,geological disasters and human activity,the working environment of submarine pipeline is too complicated to be suspended easily,once the pipeline suspended span exceeds a special limit,the submarine pipeline will easily rupture,resulting in huge economic losses and serious environmental pollution.Therefore,it is necessary to carry out regular detection to locate the exact location and the state of the pipeline.This paper introduces the acoustic traveling theory in seawater,the sonar propagation theory and its equation,analyzes the influencing factors of pipeline suspended height calculation error from the backscattering strength of seabed and the submarine pipeline.Supply the traditional expression based on the submarine pipeline detection results from a variety of acoustic detection equipment,and establishes a three-dimensional visualization model of submarine pipeline.The main research contents and results are as follows:1.The error propagation formula of submarine pipeline’s suspended height is deduced based on the scan sonar image record;analyzes the influence of variation of wave grazing angle on backscattering intensity of seabed and submarine pipeline.The exists of acoustic glancing angle optimal interval is proved in the submarine pipeline inspection.The test experiment of submarine pipeline under different grazing angles is designed and the suspended height and its error are calculated.2.The gray value of the side sonar detection image is proportional to the backscattering intensity of seabed soil and the pipeline,The gray value of the pipeline image,seabed image and pipeline acoustic shadow were calculated by Photoshop software.The existence of the optimal interval of grazing angle is proved from the experimental data.Lastly the optimal interval of the submarine pipeline detecting grazing angle in the sandy seabed environment is obtained according to the experimental data and acoustic theory.3.The 3D coordinates of the submarine pipeline is obtained based on the detecting result of a variety of acoustic detection equipment.Supply the traditional expression of submarine pipeline,draw the plane deviation profile and vertical angle profile of the submarine pipeline.Lastly establish the vertical coordinates of thepipeline according to the vertical coordinates of the submarine pipeline.4.Based on the decument of the submarine pipeline detected by multi-beam system,scan sonar system and shallow layer profiler,the seabed terrain model under the submarine pipeline and the model of the submarine pipeline is established used the Navimodel software,the 3D coordinates of submarine pipeline inspection point is obtained.Then the three-dimensional model of ocean platform created by the 3dmax software is introduced into the model.Finally,the three-dimensional visualization system of submarine pipeline is established based on multi-source decument. |
