20 September 2017 Eigenfrequency detecting method with sawtooth wave modulation theory for navigation grade fiber optic gyroscopes
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Abstract
Eigenfrequency is a key parameter for the fiber optic gyroscope (FOG). An eigenfrequency detecting method for FOGs, especially for high-grade FOGs, such as the navigation grade FOGs, is proposed. The eigenfrequency is detected with the sawtooth wave modulation theory. Adjusting the frequency of the sawtooth wave to an even integer of the eigenfrequency, the error signal caused by the sawtooth wave modulation will be zero, then the eigenfrequency can be calculated by the value of the sawtooth wave frequency exactly and the bias modulation frequency is at the eigenfrequency accurately. It is demonstrated experimentally with an FOG, the length of whose sensing coil is about 1200 m, that the accuracy of the eigenfrequency measurement is better than 1.2 ppm (0.1 Hz). With its high accuracy, not only can the frequency of the bias modulation be adjusted to the eigenfrequency precisely, but also this method can be used as an eigenfrequency detector for studying the characteristics of the sensing coil according to the eigenfrequency to study the mechanism of the errors generated in the FOGs.
© 2017 Society of Photo-Optical Instrumentation Engineers (SPIE)
Xiaxiao Wang, Xiang Wang, Jia Yu, Yue Zheng, "Eigenfrequency detecting method with sawtooth wave modulation theory for navigation grade fiber optic gyroscopes," Optical Engineering 56(9), 094109 (20 September 2017). https://doi.org/10.1117/1.OE.56.9.094109 . Submission: Received: 19 July 2017; Accepted: 6 September 2017
Received: 19 July 2017; Accepted: 6 September 2017; Published: 20 September 2017
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