Study On Three Dimensional Reconstruction And Evaluation Technology Of Aero Engine Blades

Aero engine blades are one of the important components of aero engine.Not only in high speed and high pressure environment,aero engine blades are also vulnerable to foreign objects damage because of hostile working environment.Therefore,it’s significant for the maintenance and reprocessing of aero engine blades to obtain the information of engine blades profile and damage.The working part of blades are made of free-form surfaces and the blades must has a precise size and shape based on working environment which makes the blade manufacturing technology to become one of the most complex manufacturing technology of aircraft.So getting accurate blade three-dimensional model becomes the primary precondition for blade manufacturing.Reverse engineering generally refers to the procedure that transforming the physical model into a digital model by using some three-dimensional modeling methods combined with measurement equipments and methods.This thesis studied the areas of measurement and reconstruction for aero engine blades which considered the blades’ free-form surface and high precision with reverse engineering.According to the principle and method of point cloud registration,a virtual axis and center point are calculated by using high precision location-based technology.Coordinate of Measurement data is transformed by constructing quaternion and quaternion transformation.The fitting error caused by turntable mechanical error is eliminated with ICP(Iterative Closest Point)algorithm.The point clouds of complex blades’ surface could be matched automatically which has high precision in the manner of 360 degrees scanning.The three-dimensional measurement system of aero engine blades is designed with the method as the core.The three-dimensional measurement system was used to collect the point cloud data of the high pressure turbine blades and the compressor blades.The 3D digital model of blades are reconstructed by the reverse software Geomagic Studio.Finally,not only the accuracy and stability of the blade measurement system,but also the smoothness and error of the blades reconstruction model both are analyzed.It is proved that the high precision automatic fusion algorithm has the advantages of precision and efficiency by this paper.And the error ofreconstructed model can meet the requirements of precision.The data supporting of the maintenance,processing and manufacturing for blades is provided by the digital reconstructed model of blades.