Research On Digital Design Method Of Ship Surface Based On Reverse Engineering

In recent years,with the development of science and technology,reverse engineering technology has developed rapidly.More and more industries have made comprehensive innovations by using reverse engineering technology.Due to its advanced technology and innovation,reverse engineering has been widely used in automobile,aerospace,medicine,cultural relic restoration and other fields.During the process of ship design and construction,a lot of manpower and time are needed in new ship design,construction quality inspection and parts inspection and repair.In order to speed up the pace of absorbing advanced technology,shorten the development cycle of new ship and improve the efficiency and quality of ship construction,reverse engineering is applied to ship design and construction,and the digital design method of ship surface based on reverse engineering is studied in this paper.This paper mainly studies the progress of data preprocessing;surface reconstruction and surface parameter extraction.Firstly,the point cloud data of propeller and ship model are obtained.According to the characteristics of the measured data,methods of multi-view cloud alignment,point cloud de-noising and simplification are mainly researched.The general methods of point cloud preprocessing are introduced.The multi-view point cloud is aligned by the improved ICP algorithm,and the point cloud is de-noised and simplified by the chord deviation method.In this paper,these point cloud processing methods are applied to the data processing of propeller and ship model.The pre-processed point cloud data can meet the accuracy requirements of curve and surface reconstruction.Surface reconstruction is carried out on the basis of data preprocessing and the processed point cloud data is imported into CATIA.The propeller and ship model is reconstructed by the digitized shape editor and powerful surface modeling function in CATIA.Using the mixed surface modeling method,the data are triangulated firstly,then the data are segmented according to the characteristics of point cloud data and the characteristic wireframe is created.On the basis of characteristic wireframe,surface slices are fitted in different ways.At last,the reconstructed surface of the propeller and ship are obtained by operations of split and join.After surface reconstruction,the causes of the errors in each step are discussed.The smoothness and accuracy of the reconstructed surface are analyzed and evaluated.Through surface correlation evaluation,the smoothness and accuracy of the reconstructed surface of propeller and ship model can meet the requirements.Finally,the parameters of the reconstructed surface are extracted by the secondary development technology of CATIA.The three-dimensional points of propeller and ship model are obtained,and the two-dimensional profile diagrams are generated to realize the redesign of the surface.On the basis of the key technologies of reverse engineering,this paper applies reverse engineering to ship engineering.Through the two examples of surface reconstruction of propeller and ship model,this paper expounds the main steps of digital design method of ship surface based on reverse engineering,and the method adopted can be referenced in actual ship design and detection.