Measurement Of Aviation Blade Based On Nondiffraction Grating Structured Light With Adjustable Parameters And The Related Theory Study

Aviation blade is very important to the engine. However, the existing measurement method for aviation blade can not meet the demand of high efficiency and resolution. To solve those problems, a new generation method for non-diffraction grating structured light(NGSL) with adjustable parameters has been proposed here. Major techniques and prospect application are in-depth studied in the dissertation. The main outlines are as follows:A new method based on two optical plane mirrors for generating grating structured light with adjustable parameters and non-diffraction characteristic is proposed. Theoretical analysis and simulations have been carried out to verify the feasibility of the system.Beam expanding method and image speckle suppression algorithm have been carried out for the generated strips, and the phase information can be obtained with both phase error-compensation algorithm based on five images with ?/2 phase shift between each otherand path unwrap algorithm based on special path. Factors which affect the phase precision are also analyzed and the further improvement measures are put forward.System calibration has been studied with telemetric projection measurement model,and its calibration relationship is obtained according to pinhole camera model and the projection optical geometry. Height information of object's surface can be obtained by the deformed strips. Feasibility and accuracy of the model are verified through calibration experiments. Error analysis is also studied.Measurement platform has been set up and some specific surfaces of the aviation blade have been measured as well as their surface matching, Error analysis and compensation method are also studied with good results. This paper will be provided as a new research direction to solve the problem of non-contact on-line measurement for free-curve surface.