The Research On The Surface Reconstruction Of Thetip-defective Areo-engine Blade

In the aero engine,aviation blade is the core component of the compressor and turbine,it works under high temperatures、pressures and high speed,the harsh environment will easily cause damage on the blade,including pits、distortion、worn and so on,a small change in the blade geometry may significantly affect the dynamics performance of the aviation engine.So the precision repair for the defected blade become a key problem during the maintenance of the aviation engine.The current research status mainly focus on the repair for a tip-defective blade or the middle part-defective blade.This article works on the repair for a tip-defective blade,carried out some research on the reconstruction of the surface and path planning for the grinding,The main contents are as follows:Firstly,based on the analysis for the defected blade,we confirmed the advantage and disadvantage of the contact measurement and non-contact measurement,using the Renishaw REVO Coordinate measuring machine inspect the defected blade,and get the point cloud data,and then use the Imageware to make the radius compensation of the data.After that,we propose the ICP(Iterative Closest Point)algorithm based on KD-tree acceleration,calculate the transformation matrix and translation vector,and match the point cloud we inspect.Secondly,make a point cloud stratification for the matched point cloud,which is intercept by a series of plane that perpendicular to the stacked axis.After that,in order to rise the accuracy of the profile curve which is fitting by the section point cloud,we make a sorting for the section point cloud,which is based on the principle to solve the TSP(Travelling Salesman Problem)by genetic algorithm,in this way,we find an order of the point that the distance by connecting all the points is the shortest.Then we smooth the section point cloud by Gaussian Smoothing,which is implement by the Imageware.Thirdly,make some research on the free curves and surfaces modeling technology,and use the method to interpolate the point cloud to get NURBS curves.After that,on the base of a set of NURBS curves,using the lofting method to reconstruction the NURBS surface of the blade.Then,we compute out the target control point in the direction of V,and extend the blade surface to the target control point,get the reconstructed surface of the tip-defective area.Finally,implement those algorithm above to finish the whole reconstruction process and make some plans for the path of grinding the blade.