PROJECT TITLE :

Moiré-Based Interferometry for Magnification Calibration of Bitelecentric Lens System

ABSTRACT:

The bitelecentric lens system is widely employed in several domains, like three-D measurements and tube inspection. The magnification calibration for such a system may be a crucial problem for its further application in achieving precise measurements. However, it's tough to obtain an accurate result using a general magnification calibration method. During this paper, the Moiré-based mostly interferometry is demonstrated to accurately calibrate the magnification of bitelecentric lens system that increases the speed and precision of the measurement. 2 special grating marks containing higher and lower elements with slightly different periods are designed to generate Moiré fringes. By analyzing the finally obtained Moiré fringes, the magnification may be determined through Fourier-based mostly section analysis and a section unwrapping algorithm, and also the more the deviation is from the theoretical price, the additional obvious the variations between higher and lower periods will be. Both simulations and experiments are conducted to verify the feasibility and effectiveness of the proposed approach. Results indicate that the magnification might be calibrated at the accuracy of zero.four% with extraordinary sensitivity.