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Research On Miniaturization Of Resonator Fiber Optic Gyro

Posted on:2016-11-01Degree:MasterType:Thesis
Country:ChinaCandidate:Q LiFull Text:PDF
GTID:2308330482972531Subject:Electronic Science and Technology
Abstract/Summary:PDF Full Text Request
A resonant fiber optic gyro (R-FOG) is a high-precision inertial rotate angular velocity sensor, which is based on the Sagnac effect. Compared with interferometric fiber optic gyro (I-FOG), it has the potential to achieve the same high accuracy with a shorter sensing coil, which is an advantage in terms of miniaturization and integration. At present, R-FOG is still in the experimental research stage. In addition, the optic and electronic devices with large volumes are still discrete which constitute an obstacle to encapsulation and integration of the system. This paper constructs an R-FOG prototype by the miniaturization design and research of the optic and electronic devices. The main achievements of this article are as follows:(1) The miniaturization design of the FPGA digital signal processing board is completed. It includes two parallel high-speed 14 bits analog-to digital, an FPGA signal processing chip, a PROM memory chip, a 40MHz fixed output ocillator, high-speed 14 bits digital-to-analog, 4-way operational amplifier circuit to amplify the signal to ±12V, and a power management module. The driver circuit of the photodetector (PD) is designed and tested and the miniaturization of the PD module is realized.(2) Through the theoretical derivation and simulation, this paper analyzed the error caused by the accompany modulation effect. The R-FOG system’s demodulation curve induces a zero-deviation under the residual intensity modulation (RIM) effect. Moreover, the deviation will get larger as the RIM coefficient increases. Meanwhile, the error resulted from the RIM effect is also related with the modulation frequency. A group of the best modulation frequencies with a fixed RIM coefficient is obtained by numerical simulation to reduce the system error introduced by the RIM effect to zero.(3) The accompany intensity modulation effect in the semiconductor laser is analyzed and quantified by numerical simulation. The accompany intensity modulation effect will make the demodulation curve asymmetric, which deteriorates the linearity of the scale factor. The scale factor will get larger when the resonator frequency of the FRR increases which introduces an error test the system’ performance, such as bias-zero stability. Simulation result shows that the error is 0.29°/s when the input angular velocity is 2°/s and the frequency drift is 5FSR (Free Spectrum Range).(4) Based on the miniaturized optical devices, hardware circuit, and the encapsulation structure, this article establishes an R-FOG prototype machine. Then, the performance of the miniaturized R-FOG system is tested, including the test of the scale factor nonlinearity, dynamic range, and zero bias stability. The equivalent locking precision of the resonant frequency servo loop reaches 2.65°/h (1σ) and the zero-bias stability of the gyro output achieves 89.1°/h with an integration time of Is. The zero-bias stability of the gyro output is better than 13.6°/h with an integration time of 163s. The dynamic range of the system is ±84°/s, and the nonlinearity of the scale factor is 0.354%.The results of the study provide a reference for the research of the R-FOG system’ miniaturization and intensity modulation induced noise.
Keywords/Search Tags:Resonator fiber optic gyro, Miniaturization, Intensity modulation induced noise, Digital signal processing system, Package
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