Study On Measurement Of 3D Photography In Aero Engine Vane

The quality of aero engine vane is important for the performance of plane system, the method how to measure the 3D photography of aero engine vane automatically is a new research trend. Based on the current status of making and measurement in aero engine vane, this paper presents the optical non-contact method for the aero engine vane and summarizes the current status and developmental trend. For the grating projected method can get the objects high information by analyzing the change grating and its theory is very easy, measurement speed is quick, information data is large etc, we choose the grating projected phase method ,then the important thing is to measure the vane aero engine by the method.Analyzing the grating projected phase method particularly and considering the system of aero engine vane, the paper presents the structure of all measurement system. The optical projected technology is very good and based on the original mechanical sine wave projected system, we design an all digital (DLP) sine wave grating projected system, it is very useful for the developing of measurement theory and much experiment.Phase calculating and unwrapping are important in the grating projected measurement, based on the classical phase calculating, we design an error compensation phase calculating based on average method. This method is testified for restraining the imaging noise effectively and advancing the phase calculating precision by experiments; On the phase unwrapping side, considering the disconnected point in the phase map and imaging noise, we design an area correlative phase unwrapping and describe the unwrapping method, this method is also testified for restraining the disconnected point in the phase map and imaging noise effectively.Referring to the trend of grating projected method, the two phase projected method and encoding phase method is described in this paper. In the first part, two phases method are designed particularly and testified effectively for complex object shape by much experiment. In the other part, the encoding grating projected method is also designed for measuring the complex object shape, at the same time , the encoding method, code character, particular stepping are all designed.In the calibration of the measurement system, all calibration parameters of system are described particularly and correcting the space between grating. In the experiment of measuring the aero engine vane, three experiments described and the grating projected method testified effectively for measuring 3D of aero engine vane. at last, we analyze the error reason and present the method for resolving the error.