Inspection Of Aero Engine Blade Cross-sectional Feature Parameters

As one of the national strategic emerging industries,research and development of the aircraft engine and its related products will enter a rapidly increasing period in the next few years.The aircraft engine blade is one of the most core components of the engine,its manufacturing level directly determines the performance of aircraft engine,which is also the key of the future research.Blade is a typical free surface component,and it needs running continuously under a working condition of high temperature,pressure and speed,thus making it have strong distortion,thin-walled,easy to deformation,low damage and other technical characteristics.It also puts forward strict requirements on its machining process,and how to efficiently and fast detect processing quality is a difficult problem in the process of blade manufacture.In addition,the blade process and repair are also important work to guarantee its lifecycle improvement.Blade detection is the key to ensure the quality of processing,the surface detection is mainly about parameters of each cross section.In this paper research is mainly aimed at extracting characteristic parameters including the front and back edge,chord length,maximum leaf thickness.Considering the actual measurement,early period processing of the measurement data before parameters extraction is studied.Simulation experiment done with UG and VS2008 verifies the feasibility of the algorithm,the paper content includes:1.Analysis and comparison of the methods and technical difficulties on aircraft engine blade cross section parameters extraction,to improve the practicability,the complete process of extracting parameters is put forward.2.Interpreting the relative merits and scopes of sort algorithms based on distance,polar coordinates,dichotomy and mean line.The original mean line sorting method is improved,based on rectangular corrosion method,and the scope of the rectangle corrosion method and distance is discussed.Finally,the algorithm is verified.3.The unification of the workpiece measurement coordinate system and the CAD model coordinate system.Detail coarse and fine matching process of the point clouds,as well as the process of NURBS curve fitting and the point projecting to NURBS curve.Using a simulation realizes the unification of measurement coordinate system and the CAD model coordinate system,and the matching precision of the algorithm verified can be up to 10^-5 mm.4.Extracting aircraft engine blade section parameters.The partition of the blade section measurement data and the extraction of the various characteristic parameters?including front and back edge center,radius,chord length,type string dip angle,maximum leaf thickness?are studied and methods are put forward.The blade section measurement data is divided into four parts?the leading edge and trailing edge,basin,back?,characteristic parameters especially arc is in detailed research.In addition,the use of UG/Open Grip realizes the collection of blade measurement data,and the feasibility analysis of the algorithm.