High-Resolution Angular Displacement Technology Based on Varying Moiré Figure Phase Positions

• Published in: IEEE sensors journal Vol. 19; no. 6; pp. 2126 - 2132
• Main Authors: Yu, Hai, Jia, Xingdan, Wan, Qiuhua, Liang, Lihui, Zhao, Changhai
• Format: Journal Article
• Language: English
• Published: New York IEEE 15.03.2019; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Angular measurement; Angular position; Arithmetic; Calibration; Coders; Displacement measurement; Gratings; High resolution; Image resolution; Measuring instruments; moiré figure; phase difference; Phase measurement; Sensors; Signal resolution
• ISSN: 1530-437X; 1558-1748
• DOI: 10.1109/JSEN.2018.2886309

Angular displacement measurement is a popular research subject. The grating of traditional angular measurement devices uses multi-circle code and is difficult to miniaturize. This paper proposes a novel angular displacement technology based on varying moiré figure phase positions which allows for reduced volume and high-resolution angle measurements in small-size gratings. First, a moiré figure phase model is established and the calculation arithmetic is written. Second, the proposed arithmetic based on differences in moiré figure phase positions is completed accordingly. At last, a test device was fabricated based on the proposed theory with a total diameter of 35 mm and grating diameter of 25 mm. These tests show that angular displacement method based on differences of moiré figure phase positions can achieve a high resolution measurement when the diameter of calibration grating is small. We hope the results of this paper provide a workable theoretical foundation for future photographic encoders.