A Calibration Method for System Parameters in Direct Phase Measuring Deflectometry

Applied Sciences

Nan Gao¹  Xiaoting Deng²  Zonghua Zhang² 

[1] School of Mechanical Engineering, Heibei University of Technology, Tianjin 300130, China;State Key Laboratory of Reliability and Intelligence of Electrical Equipment, Hebei University of Technology, Tianjin 300130, China;

关键词: system parameter calibration;    fringe reflection;    phase matching;    specular surface measurement;    direct phase measuring deflectometry;   

DOI  :  10.3390/app9071444

来源: DOAJ

【 摘 要 】

Phase measuring deflectometry has been widely studied as a way of obtaining the three-dimensional shape of specular objects. Recently, a new direct phase measuring deflectometry technique has been developed to measure the three-dimensional shape of specular objects that have discontinuous and/or isolated surfaces. However, accurate calibration of the system parameters is an important step in direct phase measuring deflectometry. This paper proposes a new calibration method that uses phase information to obtain the system parameters. Phase data are used to accurately calibrate the relative orientation of two liquid crystal display screens in a camera coordinate system, by generating and displaying horizontal and vertical sinusoidal fringe patterns on the two screens. The results of the experiments with an artificial specular step and a concave mirror showed that the proposed calibration method can build a highly accurate relationship between the absolute phase map and the depth data.

【 授权许可】

Unknown