Research On Multi-view Point Cloud Alignment And Registration Technology Under The Environment Of CATIA

Digital assembly technology is a key point of modern assembly method, representing thedevelopment direction of aircraft manufacturing technology. At the same time, digital qualityinspection technology of the aircraft assembly is taking on an increasingly important rolethroughout the entire process of aircraft manufacturing. Existing inspection methods cannotmeet the requirements of full range testing on the assembly quality, so that the appropriateoperating specifications must be established and based on the characteristics of inspectionmethod appropriate to digital assembly design. The topic of this thesis focuses on thedifficulties in current aircraft digital assembly quality inspection, and the multi-view dataalignment and surface registration methods are researched. The main contents of this thesisare as follows:The principles of multi-view measurement point cloud data alignment are analyzed, andcombined with advanced instruments in school lab, the new data alignment method isproposed by the use of joint multi-view measurement system comprising of three-dimensionallaser tracker and3D scanning measurement equipment. Firstly, the basic principles of pointdata alignment is introduced, then the composition of the measurement system is described,and finally the system workflow and multi-angle measurement data coordinate unified methodis approached to achieve the final completion of data alignment.The registration of aligned point cloud data with CAD model is studied. The classicalregistration methods are analyzed, and combined with the research background, a newregistration method is proposed. Three pre-processing steps of the point cloud and CADmodel registration are proposed, then two-step registration method of the preprocessed pointcloud and the CAD model is raised: firstly, combining with research background of thisthesis, the coarse registration method is introduced by the use of laser tracker to measurelocation reference point’s coordinates in the measurement coordinate system.Then accordingto the coordinates of location reference points in the theoretical model coordinate system,thecoarse registration is completed. Then an improved ICP algorithm is raised to realize the ultimately precise registration of point cloud data and CAD models.Based on CATIA\CAA software secondary development platform, the digitalmeasurement prototype system is developed. Firstly the principle of secondary developmentis introduced, and then the structure and function is analyzed and workflow of the system isresearched. At last, related functions modules of the digital detection system are developed.