Research On Key Techniques Of Reverse Engineering Machining Of Large Ellipsoid Complex Surface

In core equipment manufacturing of China’s aerospace,energy,heavy carrier and other major engineering fields,there are generally a class of large ellipsoidal complex surface parts of high-performance requirements.Because of large geometric dimensions,low structural rigidity,difficult material processing and other manufacturing characteristics,these large ellipsoidal complex surface parts are easy to produce large structural deformation in the processing stage.Therefore,it is necessary to use the idea of reverse engineering processing,that is,"data acquisition-point cloud pre-processing-CNC machining" integrated manufacturing methods to ensure its processing accuracy.This paper focus on the research on the key technology of reverse engineering large ellipsoidal complex surface parts and performs functional validation of the data processing software to address the problems in reverse engineering large ellipsoidal complex surface parts.The research has laid the foundation for the reverse engineering of large ellipsoidal complex surface parts,which has important theoretical significance and practical application value.In this paper,the following research and analysis was conducted.(1)A study to determine the data acquisition scheme in the reverse engineering of large ellipsoidal complex surfaces.By analyzing the advantages and disadvantages of different devices and measurement methods,the data acquisition method is determined by combining the structural characteristics of the workpiece and the requirements of the processing technology,and the conversion of the data acquisition and subsequent processing data is determined.(2)A study of point cloud data denoising and smoothing methods in reverse engineering of large ellipsoidal complex surfaces.To address the problem of low efficiency and accuracy of the existing denoising and smoothing methods for the smoothing of point cloud data on large ellipsoidal complex surfaces,a denoising and smoothing method based on the S-H-ESD algorithm and bilateral filtering algorithm is proposed,and the experimental results prove that the algorithm can quickly and effectively denoise and smoothing large ellipsoidal complex surface data.(3)A study of point cloud data streamlining methods in large ellipsoidal complex surface reverse engineering techniques.To address the problem that the existing point cloud refinement algorithms cannot preserve the fine feature points in the point clouds of ellipsoidal surfaces,a point cloud refinement algorithm based on principal component analysis(PCA)and adaptive mean drift is proposed.(4)The design and development of point cloud data processing software for large ellipsoidal complex surface reverse engineering technology.A comparative analysis determines the development environment and development software for the point cloud data processing software,designs the module composition and functions of the point cloud data processing software,and conducts interface development and functional design and functional validation of the software.(5)A study of the workpiece point cloud data CNC machining method,and the experiment with the actual equipment manufacturing site to carry out large ellipsoidal complex surface reverse engineering processing technology verification.This section analyzes the advantages and disadvantages of the existing point cloud for CNC machining methods,combines the structural characteristics of large elliptical parts and the overall process of reverse machining technology,selects the appropriate method for CNC machining simulation and CNC machining program generation.According to the workpiece point cloud data acquisition scheme,point cloud data denoising smooth method,point cloud streamlining method and point cloud CNC processing method designed in this paper,the large ellipsoidal parts of the actual manufacturing equipment site is manufactured by reverse engineering machining method and this section analysis of processing results.The results prove that the large ellipsoidal complex surface reversal engineering processing technology proposed in this paper meets the processing requirements of actual engineering projects,and complies with site operation procedures and specifications,which has the significant theoretical significance and practical application value.