Research On Fast Measurement And Error Analysis Of Forging Blade

Aero blades are manufactured by procedure of forging forming,machining center milling,grinding and surface preparation.Eliminating unqualified blade and adjusting forging hammer by forging error feedbacks are the key factors of cost reduction and blade yield rate improvement.Based on characteristics of forging blades,this study offers solutions for key problems like 3D point-cloud alignment,blade section analysis,etc.This study programs the data processing software according to the object-oriented programming and plug-in class ideas.The specific research and innovation including:Research in 3D point-cloud alignment algorithm.In order to solve the problem caused by mark hole feature extraction and machining allowance difference between blade end bosses and blade surface,this study proposes a mark hole nodes extraction algorithm based on Dijkstra’s algorithm.Mark hole nodes fitting completes the extraction of mark point.Alignment based on SVD algorithm can solve the problem of getting refection transformation instead of getting alignment transformation,which is caused by the coplanarity of mark points.The accuracy of feature extraction is verified by comparing the experimental results of the precision of mark points extraction.The accuracy of the alignment algorithm is verified by comparing the experimental results of the error distribution and the error calculation results of the sample points.According to the alignment of forging blades without mark hole,put forward iterative closest point alignment algorithm(ICP)based on manual selection.Research in blade section analysis algorithm.Because of the points of blade sections are non-uniform and the trailing edges are square,it is not convenient to use the conventional fitting analysis method to analyze the sections.To solve this problem,this study presents an algorithm for the segmentation of the blade section points.The moving least square method is used to encrypt the section points set,and then the characteristic parameters of the blade section are obtained by the method of point set segmentation and enumeration.The accuracy of the section data segmentation and analysis algorithm is verified by the experiment of section characteristic parameters’ results comparison.To calculate unclosed distance and lateral displacement of forging hammer,this study presents an algorithm based on non-rotating 2-D ICP alignment algorithm.In this algorithm,by introducing the point-to-plane error metric,the requirement of non-rotating translation calculation is obtained.Data analysis software programming.Applying the algorithms in this study,blade data processing software,which is developed in C++ with Qt programing environment,meets the demand of automatic measurement of forging blade.The accuracy of the data processing software is verified by comparing the error calculation results with the three coordinate measuring machine’s.