Research On Fast 3D Measurement Method Based On Color Structure Light Projection

In aero-engine,blade is a key component which is responsible for airflow guidance,and its profile directly affects the performance of the engine.How to realize high-precision,high-efficiency and automatic measurement of engine blade has become a hot issue in current research.In this paper,the existing 3D measurement methods for aero-engine blades are studied.Combining the phase theory with phase measurement profilometry,a phase measurement method based on color-trapezoidal structured light and a phase unwrapping method based on color-bar-coding structured light are proposed.In this method,only two structural light images are demanded to obtain 3D information of discontinuous objects.The main work includes:1?Analyzed the current situation of the aviation industry and its demand for 3D measurement technology.Discussed the current 3D measurement methods applicable to the measurement of aero-engine blades according to the requirements of high precision,high efficiency and automation.The research direction based on color structured light projection is determined.2?The phase distribution acquisition methods which are commonly used in optical 3D measurement are studied and analyzed,including wrapped phase acquisition method and phase unwrapping method.Then the accuracy and efficiency of each method are compared.3?Combining phase measurement profilometry with phase theory,a wrapped phase acquisition method based on color trapezoidal coding structured light was proposed,and a phase unwrapping method based on color stripe coding structured light was proposed for discontinuous surface measurement.4?According to the 3D measurement theory in this paper,the hardware system is designed and built.The software is coded with QT and MATLAB.5?The 3D measurements of the aero-engine high pressure compressor rotor blade and low pressure turbine rotor blade are realized,and the measurement result of high pressure compressor rotor blade is compared with the result of the product-level CMM.The accuracy of this method is verified and the measurement efficiency is analyzed.