Papers by Keyword: Fiber Optic Gyroscope (FOG)

Abstract: Aiming at the problem of modeling and compensation of the fiber optic gyroscope (FOG) drift caused by temperature, a novel compensation method for FOG temperature drift based on transformed unscented Kalman filter (TUKF) is proposed. Elman network with faster convergence speed is used to modeling and TUKF algorithm is adopted to train the weights of Elman network, which effectively solves the problem of numerical instability. The results prove that the proposed method has higher precision compared with Elman network and IUKF network models. By using the TUKF algorithm, the root mean square errors (RMSE) are improved by 60%  in temperature rise period and 50.5% in fall period.

Abstract: Two-position north determining scheme for FOG north seeker can effectively eliminate the impact of drift, and can be easily implemented. But the angle between the base and the horizontal plane will induce tilt error and reduce the north seeking accuracy. In order to eliminate the tilt error and to improve the north seeking accuracy, the corresponding tilt compensation scheme is designed in this paper. A tilt sensor is used to measure the angle between the base and the horizontal plane, and the DSP is used to collect the output of the tilt sensor and solve real-time compensation. North seeking experiments proved that this tilt compensation scheme can compensate the base plane tilt error, and improve the north seeking accuracy effectively.

Abstract: This paper used the timing analysis to statistically analyze the output sequences of many FOGs which were using in the north-finding system. We confirm an optimal model basing the statistic characteristics, and finally advance a fixed algorithm to estimate the parameters of the model. The results show that the modeling method has the universality to the output data of FOGs in the north-finding system, and also can be used to get the precise parameters in order to serve the following filter.

Abstract: Allan variance based spline fit method is designed to determine some key technical specification of fiber optic gyroscope including random walk coefficient, bias stability, rate ramp, quantum noise, rate random walk, and so on. LabView based visualization data collection program is developed to sample the output digital data of KVH E•Core 2000 fiber optic gyroscope. The test results show that the method is good for improving the specification determination accuracy, and can simplify the test flow as well.

Abstract: The basic working principle and the two-position north-seeking method based on single-axis FOG(fiber optic gyroscope) is researched in this paper. Improved north-seeking method was proposed to solve the problem in the two-position FOG north-seeking scheme. To Sample in three positions of 0º, 90ºand 180ºseparately and obtain the measurement values of angular rate in these three positions. Then according to the measurement values of angular rate in the first and the third positions to calculate the north-seeking angle, and using the positive and negative pulse outputs of the FOG in the second position to obtain the specific direction information of carrier. So that, accomplish the north-seeking in the range of 0～360° for single-axis FOG. The experiment results showed that the accuracy of the improved two-position north-seeking program based on single-axis FOG is 0.101 (1σ) within 4 minutes.

Abstract: Digital open-loop fiber-optic gyroscope detection scheme based on sinusoidal phase modulation is introduced. A novel implementation of the detection scheme is developed with digital signal processor (DSP) and field programmable gate array (FPGA). The design and implementation of the detection system are discussed. Timing control and open-loop signal preprocessing are realized in FPGA. Rotation rate calculation is finished in DSP. Experiments result shows that good performances have been achieved and the implementation scheme is of great practical value.

Abstract: To reduce the noise error existing in the output signal of fiber optic gyroscopes (FOGs) and increase the precision of the FOGs, this paper established a mathematical model of the FOGs output signal, analyzed the error characteristics of the FOGs output signal, put forward a new de-noising arithmetic based on the wavelet transform, soft and hard threshold compromise filtering, threshold values were determined by multi-dimensions recursion arithmetic. Through experiment, it has been already validated that the proposed approach had the competitive performances on visual quality, signal to noise ratio (SNR) and the standard variation, it is effective in eliminating the white noises existing in the output signal of the FOG.

Abstract: . We propose a new concept of a micro gyroscope which is made by a nonlinear micro ring resonator (i.e. 5-10 microns). The nonlinear behavior of polarized light known as polarization mode dispersion in the micro ring device is introduced by material birefringence (i.e. refractive index), which is described. In practice the measurement of polarization mode dispersion can be performed by projecting the output light into a polarizing beam splitter and detectors, where the change in phase is occurred, and then the birefringence is calculated. In addition, the property of the two orthogonal components (i.e. horizontal (H) and vertical (V) components) can be formed the photon entanglement. Which means the entangled photon can be generated, where the state timing walk-off can also be measured and compensated. The design of micro gyroscope is now capable to reduce the device scale in the micron regime to meet more possible applications such as for the measurement of temperature, pressure, and force based on birefringence sensor, which will be discussed in details.