Showing papers on "Fibre optic gyroscope published in 2019"
TL;DR: The results of the analysis of both the static and dynamic signal tests indicate the effectiveness of the proposed denoising method, which is based on processing the intrinsic mode functions (IMFs) obtained by empirical mode decomposition (EMD).
Abstract: To suppress the random drift error of a gyroscope signal, this paper proposes a novel denoising method, which is based on processing the intrinsic mode functions (IMFs) obtained by empirical mode decomposition (EMD). Considering that a gyroscope signal contains colored noise in addition to Gaussian white noise, fractal Gaussian noise (FGN) was introduced to quantify the noise in the gyroscope data. The proposed denoising method combines the FGN energy model and the modified method of Hausdorff distance (HD) to adaptively divide the IMFs into three categories (pure noise, pure information, and mixed components of noise and information). Then, the information IMFs and the mixed components after thresholding were selected to give the optimal signal reconstruction. Static and dynamic signal tests of the fiber optic gyroscope (FOG) were carried out to illustrate the performance of the proposed method, and compared with other traditional EMD denoising methods, such as the Euclidean norm measure method (EMD- l 2 -norm) and the sliding average filtering method (EMD-SA). The results of the analysis of both the static and dynamic signal tests indicate the effectiveness of the proposed method.
19 citations
TL;DR: A resonant fiber optic gyro based on Kagome hollow-core fiber permits achieving a cavity finesse of 23 with a resonance linewidth of 700 kHz and an optimized Pound-Drever-Hall servo-locking scheme is used to probe the cavity in reflection.
Abstract: We build a resonant fiber optic gyro based on Kagome hollow-core fiber. A semi-bulk cavity architecture based on an 18-m-long Kagome fiber permits achieving a cavity finesse of 23 with a resonance linewidth of 700 kHz. An optimized Pound–Drever–Hall servo-locking scheme is used to probe the cavity in reflection. Closed-loop operation of the gyroscope permits reaching an angular random walk as small as 0.004°/h and a bias stability of 0.45°/h over 0.5 s of integration time.
18 citations
TL;DR: This new approach eliminates the need for phase modulation required in I-FOGs, and promotes easy photonics integration, enabling the development of low-cost FOGs for price-sensitive applications, such as autonomous and robotic vehicles.
Abstract: We report a different mechanism for rotation sensing by analyzing the polarization of light exiting from a Sagnac loop. Unlike in an interferometric fiber optic gyroscope (I-FOG), here the counter-propagating waves in the Sagnac loop are orthogonally polarized at the loop exit and, consequently, cannot directly interfere with each other when recombined at the exit. We show that the Stokes parameters s2 and s3 of the combined waves are simply the cosine and sine functions of the phase difference between the counter propagation waves, which is linearly proportional to the rotation rate, allowing precise determination of the rotation rate by polarization analysis. We build such a proof-of-concept polarimetry FOG and achieved key performance parameters comparable to those of a high-end tactical-grade gyroscope. In particular, the device shows a bias instability of 0.09°/h and an angular random walk of 0.0015°/h, with an unlimited dynamic range, demonstrating its potential use for rotation sensing. This new approach eliminates the need for phase modulation required in I-FOGs, and promotes easy photonics integration, enabling the development of low-cost FOGs for price-sensitive applications, such as autonomous and robotic vehicles.
17 citations
TL;DR: The results denote that the method provides a cost-efficient manner of performance improvement compared to the open-loop I-FOGs based on a piezoelectric modulator.
Abstract: This paper presents a simple method for compensating the Sagnac phase shift in an interferometric fiber-optic gyroscope (I-FOG) with a piezoelectric modulator. The common advantages of I-FOGs with closed-loop compensation are linearized output characteristics and insensitivity to the light source power, including its time and thermal-induced fluctuations. Whereas closed-loop operation is normally achieved via ramp modulation requiring an electro-optic modulator, all-fiber architectures with a piezoelectric modulator are mostly limited to open loop. Nevertheless, such setups can more conveniently utilize a less expensive single-mode fiber with depolarized light and do not require any custom-made components. The proposed method allows us to combine the advantages of both approaches. Closed-loop compensation is ensured by adding further sinusoidal modulation to the common biasing modulation, such that the Sagnac phase shift is compensated solely at the sampling instants. We describe and experimentally demonstrate the proposed approach, utilizing a test setup to compare our closed-loop solution with open-loop operation. The results denote that the method provides a cost-efficient manner of performance improvement compared to the open-loop I-FOGs based on a piezoelectric modulator.
11 citations
TL;DR: In this paper, a modulation/demodulation algorithm was proposed to measure the response of a phase modulator in a closed-loop fiber-optic gyroscope (FOG) of navigation and tactical grade.
Abstract: A lithium niobate (LN) phase modulator is widely spread because ofhigh electro-optic coefficients. Particularly, it is a highly required component for a closed-loop fiber-optic gyroscope (FOG) of navigation and tactical grade. However, low-frequency distortions of LN phase modulator frequency response can degrade the FOG performance. This paper deals with the research and compensation of frequency response of an LN phase modulator. It is a complex task to measure the response of the LN phase modulator in a FOG because of its Sagnac interferometer. Therefore, the special and novel modulation/demodulation algorithm is proposed. To the best of our knowledge and belief, the proposed method is the first published method that provides the measurement of the pulse response of a phase modulator as a part of a closed-loop FOG. The pulse response obtained in the proposed way allows getting appropriate high order transfer function of a phase modulator. For the first time to the best of our knowledge, the humidity dependence of the LN phase modulator frequency response is found. Influence of the phase modulator frequency response on FOG angular random walk, bias drift, and scale factor nonlinearity and instability is theoretically analyzed and mathematically simulated. The algorithmic method of the phase modulator response compensation is proposed and experimentally confirmed. The experimental results show that the proposed measurement technique of the phase modulator transfer function allows creating the compensating inverse filter that provides phase modulator response being close to flat. The application of the proposed method in the FOG operating mode allows reducing unwanted spikes to the noise level.
10 citations
28 Aug 2019
TL;DR: In this paper, the status of three current efforts to develop optical gyroscopes with improved performance over state-of-the-art fiber optic gyroscope (FOGs) in terms of accuracy, size, and/or cost is summarized.
Abstract: This review summarizes the status of three current efforts to develop optical gyroscopes with improved performance over state-of-the-art fiber optic gyroscopes (FOGs) in terms of accuracy, size, and/or cost. The first approach consists in replacing the temporally incoherent Er-doped fiber source used in FOGs withy a low-coherence laser whose linewidth is broadened to tens of GHz by an external phase modulator driven by noise. A FOG with a 3.24-km coil interrogated by such a source has recently produced a noise and a drift approaching strategic-grade performance, and exhibits a source mean-wavelength stability below 1 ppm. The second approach is the use of a hollow-core fiber (HCF) in the sensing coil of a FOG to reduce thermal drift. A FOG utilizing 250 m of polarization-maintaining HCF and interrogated with a broadened laser is shown to exhibit a noise of 0.135 deg/√h limited by backscattering arising from surface modes in the fiber, and a drift of 1.2 deg/h dominated by polarization coupling. The third investigation is an optical gyroscope made of two coupled ring resonators, one exhibiting loss and the other one gain, operated at or near an exceptional point. Time-domain simulations predict that when operated below threshold and interrogated with a conventional biasing and read-out scheme, this gyroscope exhibits a rotation sensitivity at least 170 times larger than an optimized single-ring resonator with the same radius (5 mm) and loss (0.5 dB). Such systems have a great potential for producing a new generation of gyroscopes with significantly smaller footprints than FOGs.
10 citations
TL;DR: In this paper, a new kind pentagonal polarization-maintaining photonic crystal fiber, and its polarization characteristic under the influence of temperature was analyzed based on the theory of the thermal expansion effect and thermal optic effect.
8 citations
01 Apr 2019
TL;DR: In this article, a multifunctional, photonic integrated circuit (PIC) is developed, specially designed for low-cost manufacturing of high-end tactical-grade fiber optic gyroscopes (FOGs).
Abstract: A multifunctional., photonic-integrated circuit (PIC) is developed., specially designed for low-cost manufacturing of high-end tactical-grade fiber optic gyroscopes (FOGs). The PIC comprises functional integrated FOG components that compose the so-called “heart of the interferometer” based on a highly polarization-maintaining (PM) waveguide. FOGs with different fiber coil sizes are built using the PICs; the PIC FOGs are also called photonic gyros. A photonic gyro with a 110-meter-Ionz fiber coil of 6cm diameter is demonstrated to have $\pmb{0.59^{\circ}/\mathrm{hour}/\surd\mathrm{Hz}}$ angle random walk., 0.048°/hour bias drift, 15.44 ppm scale factor error, 0.24°/hour bias instability, and 43.09 ppm scale factor instability over a temperature range of −40 to 75°C.
8 citations
04 Mar 2019
TL;DR: In this paper, a new gyroscope architecture inspired by parity-time-symmetric optics is proposed and theoretically modeled, which consists of two ring resonators coupled together, one with loss and the other with gain, with a loss and gain selected such that the device does not lase.
Abstract: A new gyroscope architecture inspired by parity-time-symmetric optics is proposed and theoretically modeled. It consists of two ring resonators coupled together, one with loss and the other with gain, with a loss and gain selected such that the device does not lase. A narrow-linewidth laser is coupled into the loss ring to probe the coupled resonator’s rotation-dependent resonances, and a detector measures the rotation-induced change in the power transmitted by the device. Assuming that the small-signal gain is smaller than the loss, a common radius for the two rings of 5 cm, and imposing that the power in the gain medium never exceeds 10% of the saturation power to avoid gain saturation, we demonstrate that this structure has a sensitivity to rotation ~170 times larger than an optimized resonant fiber optic gyroscope of equal ring radius and loss. Such loss-gain coupled resonators are known to exhibit an exceptional point at a critical value of the coupling between resonators, at which point the device’s resonances become extremely sensitive to external perturbations such as a rotation. However, we demonstrate that the maximum rotation sensitivity of this paritytime- symmetric structure does not occur at the exceptional point. Instead, for the aforementioned parameter values and the imposition of a small circulating power, it is maximum when the inter-ring coupling is ~11% stronger than the exceptional-point coupling. This significant increase in rotation sensitivity is found to result to a much larger degree from a strong enhancement in the power circulating in the gain ring (although there is not a one-to-one correspondence), and to a much lower extent from an enhancement in the rotation-induced resonance-frequency shift.
8 citations
TL;DR: In this article, the results of a fiber-optic gyroscope prototype with 0.01-0.001deg/h drift are presented. And the authors propose to use the fourth and the fifth feedback loops which will suppress the parasitic effects in the integrated optic phase modulators.
Abstract: The results of study of a fiber-optic gyroscope prototype with 0.01–0.001deg/h drift are presented. The gyroscope comprises three feedback loops: one for Sagnac phase difference compensation, the second one for the scale factor stabilization, and the third (fast-response) one for the compensation of constant component of optical signal on the photodetector, affecting the measurement channel. To increase the accuracy of the prototype gyroscope up to the level of 0.001 deg/h, it is proposed to use the fourth and the fifth feedback loops which will suppress the parasitic effects in the integrated optic phase modulators.
8 citations
TL;DR: For a typical D-IFOG, the experimental results showed a cross-coupling degree exceeding 170% when the temperature varied from -20 °C to 60 °C, as predicted in the simulations, and verified the results experimentally.
Abstract: We propose a theory of cross-coupling drift in depolarized interferometric fiber optic gyroscopes (D-IFOGs) under the joint influence of magnetic field and temperature. The magnetic field and temperature cross-coupling drift (MTCD) originates from the interaction of the nonreciprocal circular birefringence produced by the magnetic field, the thermal stress birefringence from the varying temperature, and the inherent residual birefringence in the fiber coil. The MTCD is much greater than the sum of the individual drifts induced by magnetic field and temperature. We established a relevant theoretical model and carried out numerical simulations, and verified the results experimentally. For a typical D-IFOG, the experimental results showed a cross-coupling degree exceeding 170% when the temperature varied from -20 °C to 60 °C, as predicted in the simulations.
TL;DR: In this paper, a novel interferometric fiber optic gyro (I-FOG) sensor coil consisting of multi-core fiber (MCF) spliced with fan-in/fan-out (FIFO) devices was proposed.
Abstract: We proposed a novel interferometric fiber optic gyro (I-FOG) sensor coil consisting of multi-core fiber (MCF) spliced with fan-in/fan-out (FIFO) devices. We fabricated a 102-m long, seven-core MCF coil with FIFO devices and demonstrated the operation of the proposed I-FOG for the first time to our knowledge. The angular random walk performance of 0.002 deg/√h was achieved, thereby confirming that the seven-core waveguide loop works successfully as a Sagnac interferometer as expected.
TL;DR: The photonic crystal fiber (PCF) with better thermal stability and polarization-maintaining performance is applied to the resonant fiber optic gyroscope (RFOG) to reduce MFD-mismatch-induced splicing loss.
Abstract: The photonic crystal fiber (PCF) with better thermal stability and polarization-maintaining performance is applied to the resonant fiber optic gyroscope (RFOG). A hybrid fiber ring resonator is fabricated using the conventional polarization-maintaining fiber (PMF) and PCF with close mode field diameters (MFDs) to reduce MFD-mismatch-induced splicing loss. Furthermore, the temperature-dependent birefringence coefficients of the PMF and the PCF are measured to differ almost four times in absolute value and be opposite in sign. The polarization stability of the hybrid PCF-PMF ring resonator is improved by a factor of 7 compared with the PMF ring resonator with the same length of PMF. The RFOG equipped with this hybrid PCF-PMF ring resonator achieves a bias stability of 1.67°/h.
TL;DR: A novel and simple combined frequency-locking technology based on a phase-modulated feedback loop and a laser feedback loop is proposed by using the high-precision tuning of a phase modulator to improve the resolution and suppress the low-frequency drift.
Abstract: In the resonator fiber optic gyroscope (RFOG), the conventional laser feedback loop is realized by adjusting the laser central frequency to tracking the resonance point of the resonator. This method generally relies on the laser tuning coefficient and digital-to-analog converter, which inevitably produces quantization error and limits frequency-locking accuracy and gyro resolution. In addition, the output drift caused by low-frequency noise also is a problem with long-term lock-in tests. In this paper, a novel and simple combined frequency-locking technology based on a phase-modulated feedback loop and a laser feedback loop is proposed by using the high-precision tuning of a phase modulator to improve the resolution and suppress the low-frequency drift. Furthermore, it has been proved by experiments that the resolution is increased by 10 times, while the frequency-locking accuracy is improved from 10°/s to 0.5°/s by using the combined frequency-locking mode. In addition, the low-frequency drift is eliminated with the long-term lock-in of RFOG, and the system resolution from 1°/s to 0.1°/s is accurately displayed.
TL;DR: In this article, a new type of magnetic shield with annular cavity structure is designed based on the study of the factors affecting the shielding effectiveness for fiber optic gyroscope (FOG).
TL;DR: In this paper, a coupling effect in the singlemode fiber coil (SMFC) of a depolarized interference fiber optic gyroscope (De-IFOG) under time-varying temperature and magnetic field, which can cause a serious non-reciprocal phase error is revealed.
Abstract: A coupling effect in the single-mode fiber coil (SMFC) of a depolarized interference fiber optic gyroscope (De-IFOG) under time-varying temperature and magnetic field, which can cause a serious nonreciprocal phase error, is revealed. In this paper, the mechanism of the coupling effect is thoroughly studied and the related theory is derived in detail. Simulations and experiments are carried out to verify the validity. The experiments show a peak-to-peak value error of about 50 °/h in the SMFC when the magnitude of magnetic field is 10 Gauss and the temperature uniformly increases from 10 to 60 °C at the rate of 36 °C/h, which cannot be neglected in the applications of De-IFOGs.
TL;DR: In this article, a closed-loop fiber optic gyroscope (FOG) driven by two broadband sources simultaneously was demonstrated and the dispersion characteristic of half-wave voltage of multifunction integrated optical circuit was investigated theoretically and experimentally.
Abstract: We propose and demonstrate experimentally a low-noise closed-loop fiber optic gyroscope (FOG) driven by two broadband sources simultaneously. The basic characteristic of built-up super broadband light source (SBLS) consisting of two superluminescent diodes (SLDs) with different wavelengths was designed and analyzed. The dispersion characteristic of half-wave voltage of multifunction integrated optical circuit (MIOC) was investigated theoretically and experimentally. The tested results agree well with the theoretical model and confirm that the customized MIOC can operate well over a large spectral bandwidth. An experimental FOG driven by the SBLS was built with a solid-core polarization maintaining photonic crystal fiber coil and the closed-loop operation was realized well. Its bias drift and scale factor were tested preliminarily, and high performance is achieved compared with the FOGs with a single SLD source.
01 Sep 2019
TL;DR: In this article, the development and testing of a SiP-based three-laser source for use in a next generation compact resonator fiber optic gyroscope (RFOG) targeted for commercial navigation applications is discussed.
Abstract: This paper covers latest progress in the development and testing of a Silicon Photonics (SiP) based three-laser source for use in a next generation compact resonator fiber optic gyroscope (RFOG) targeted for commercial navigation applications.In recent years, significant progress has been made in the development of compact RFOGs using phase locked diode lasers and miniaturized optics on a silicon optical bench (SiOB) [1–3]. While we have been able to demonstrate near or at civil navigation grade performance with the technology, one of our biggest remaining hurdles is to do so using a miniaturized SiP-based multi-frequency laser source.Here we discuss the development of a compact SiP-based three-laser source based on a low-noise implementation of the Pound-Drever-Hall (PDH) method and comprising high-bandwidth optical phase-locked loops [4, 5]. These are highly coherent narrow linewidth lasers with very low differential frequency noise, which is essential to achieve the desired performance. For the first time ever, we demonstrate RFOG performance with a compact SiP-based multi-frequency laser source. Test results including angle random walk and bias results are presented and compared against past discrete laser and optic configurations.
TL;DR: A performance evaluation system for DAM of FOG based on a high accuracy single-axis rotary table is proposed and an algorithm for signal delay measurement is proposed in order to solve the problem of multi-path signal synchronization.
TL;DR: In this paper, a four-state modulation scheme is proposed to improve the stability performance of a dual-polarization fiber optic gyroscope (IFOG) operating under an open-loop configuration.
TL;DR: A double-electrode-pair multifunction integrated-optic circuit, which contains an additional pair of short electrodes besides the conventional electrode-pair, is proposed and implemented, which provides the potential of the applications in high-speed measuring and controlling systems for high-precision FOGs.
Abstract: The measuring accuracy of the fiber optic gyroscope (FOG) for weak signals under very short sampling time is significantly impacted by the quantization error, impeding its application in high-speed measurement and real-time control. In this work, we propose and implement a double-electrode-pair multifunction integrated-optic circuit (MIOC), which contains an additional pair of short electrodes besides the conventional electrode-pair. Taking advantage of the better modulating precision of the additional electrode-pair, the digital feedback is more refined and the quantization error in the FOG output is significantly suppressed. The driving circuits and the control scheme of the proposed MIOC are specially designed for FOGs. Experimental results show that the resolution for extremely small angular rates at short smoothing times is significantly improved. This work provides the potential of the applications in high-speed measuring and controlling systems for high-precision FOGs.
TL;DR: This paper theoretically analyzes the factors that influence the result of the noise subtraction method and deduces the function to calculate the noise suppression ratio that can be achieved.
Abstract: An essential issue for the low-noise system application of the fiber optic gyroscope (FOG) is to reduce its noise level. The relative intensity noise (RIN) of the light source is the dominant noise of the FOG when the light power on the detector reaches a certain level. The noise subtraction method is effective for RIN reduction and easy to implement in a FOG. This paper theoretically analyzes the factors that influence the result of the method and deduces the function to calculate the noise suppression ratio that can be achieved. A method that uses an optimum filter design based on the Wiener filter in the reference detector signal is proposed to improve the subtraction result. A FOG system is set up to test the feasibility of the method. The experiment results meet with the theoretical analysis, and by using the Wiener filter, the achieved noise subtraction factor reaches the limitation that restrains the optical system and detection circuit.
TL;DR: In this article, the DAC demodulation error is modelled as a piecewise function according to its characteristic, i.e., it appears to be a constant value when the staircase ramp ranges from 2 n−2 to 2n−1 and remains zero when the stairs ramp outs of this range, where n is the bit length of the register.
TL;DR: In this article, a model between the phase modulation actuator and temperature was proposed for high-precision interferometric fiber optic gyroscope (IOC) phase error.
Abstract: An integrated optical chip (IOC) is the phase modulation actuator in a closed-loop interferometric fiber optic gyroscope (IFOG). Research on temperature characteristic of IOC is meaningful for high-precision IFOG working in harsh environment. We focus on the temperature modeling of the IOC modulation phase error. In theoretical analysis, based on the temperature dependence of the IOC equivalent capacitance, a model between IOC modulation phase error and temperature is proposed. Through experiments, the variation tendency of the IOC equivalent capacitance with temperature is first presented. Subsequently, the IOC modulation phase error is demonstrated to be linear with temperature, which verifies the effectiveness of the proposed model. We provide an error research direction of IOC for high-precision fiber optic gyroscopes.
TL;DR: In this article, a scale factor real-time calibration and angle measurement scheme based on self-collimator is proposed to eliminate the error caused by the fluctuation of the scale factor.
Patent•
25 Oct 2019
TL;DR: In this article, a fiber-optic gyroscope system level temperature compensation method and device is proposed to solve the technical problem that existing temperature compensation is inaccurate, and the measurement deviation formed by system temperature is obtained on the basis of fully reflecting systematic temperature change and a temperature alteration ratio, and is eliminated, thus the north-seeking precision of an optical fiber inertial group is ensured.
Abstract: The invention provides a fiber-optic gyroscope system level temperature compensation method and device and solves the technical problem that existing temperature compensation is inaccurate. The fiber-optic gyroscope system level temperature compensation method includes the following steps: a system level temperature compensation platform is constructed; working condition and temperature data of the temperature compensation platform are acquired and processed; a zero-offset evaluation model is formed by using the working condition and temperature data; and zero-offset compensation is performedthrough the zero-offset evaluation model. The zero-offset evaluation model of a fiber-optic gyroscope is established in an environment having working conditions of a fiber-optic strapdown inertial group, and measurement deviation formed by system temperature is obtained on the basis of fully reflecting systematic temperature change and a temperature alteration ratio, and is eliminated, thus the north-seeking precision of an optical fiber inertial group in an environment of a total temperature range is ensured.
18 Dec 2019
TL;DR: In this article, an ASE light source with high power, high stability, high spectral symmetry and low coherence has been proposed for high precision fiber optic gyroscope (FOG) applications.
Abstract: Based on the application field of high precision Fiber optic gyroscope (FOG), high requirements are put forward for the accuracy of FOG, the stability of scale factor and the nonlinearity of scale factor. The performance of light source is closely related to the performance of these gyroscopes. Therefore, the requirements of high power, high stability, high spectral symmetry and low coherence are put forward for light source. According to the characteristics of high precision FOG, an ASE source is proposed. In the light path aspect, the physical model of ASE light source, the influence of Erbium-doped fiber length, optical path structure scheme, pump wavelength and pump power on the average wavelength of the light source are analyzed. The optical path structure and the length and pump power range of Erbium-doped fiber are determined. Through the analysis of spectral coherence, the Gauss spectrum with no sub-peak of the coherence function is selected as the filtering scheme through orthogonality. Optimize the parameters of light source by experiment and filter simulation. In the aspect of power control, improving power stability by power feedback with controlling the temperature characteristics of the feedback loop device. The ASE light source designed above can provide power output of more than 20 mW. Within operation temperature of high precision FOG, the change of wavelength stability is less than 5 ppm and the change of power output is less than 1%. It is an ideal light source for high precision FOG.
TL;DR: The frequency dependence of the halfwave voltage is proposed and a new error research direction for the improvement of the MIOC in a high-precision IFOG is provided.
Abstract: The multifunction integrated optical chip (MIOC) is one of the most critical parts of the interferometric fiber optic gyroscope (IFOG), and research on the halfwave voltage of the MIOC is meaningful for a high-precision IFOG. In this paper, the correlation between the frequency and halfwave voltage, which affects the interference light intensity of IFOG, is presented theoretically. A widespread measurement method for frequency dependence of the halfwave voltage, based on lock-in amplification and sinusoidal modulation, is proposed. Further, the measurement result and the oscillation of interference light intensity in the Sagnac interferometer are presented, which are in great agreement with the theory. This paper proposes the frequency dependence of the halfwave voltage and provides a new error research direction for the improvement of the MIOC in a high-precision IFOG.
01 Oct 2019
TL;DR: In this paper, an improved particle swarm optimization (PSO) algorithm is proposed to optimize the parameters of the segmentation delay model with the temperature range of -15 °C~50 °C.
Abstract: The temperature error mechanism of fiber optic gyroscope (FOG), and the influence of the heat transfer time delay on the temperature error modeling are analyzed. Considering heat transfer delay, a new temperature error model of FOG is established. For parameters optimization of temperature error model, an improved particle swarm optimization (PSO) algorithm is proposed. The improved PSO iterative process is divided into three stages, which sets parameters and updates particle velocity respectively. It performs an optimized search in the same number of iterations to optimize the temperature model parameters. Based on the measured data of the FOG, the improved PSO algorithm is used to optimize the parameters of the segmentation delay model with the temperature range of -15 °C~50 °C. Compared with the traditional model and algorithm, the results show that the proposed delay compensation model and improved PSO algorithm can effectively improve the accuracy of the fiber optic gyroscope, and the post-compensation drift standard deviation is reduced by 77.5%.
TL;DR: The experimental and the calculated results agree well with each other, which illustrates that the transverse magneto-optic error derives mainly from the bend-induced asymmetry distribution of the refractive index in fiber.
Abstract: The transverse magneto-optic error is a significant nonreciprocal error of fiber optic gyroscopes, particularly for the miniature fiber optic gyroscope. In this paper, the transverse magneto-optic error of a solid-core photonic-crystal fiber optic gyroscope is theoretically analyzed and experimentally measured, as well as compared with that of the conventional fiber optic gyroscopes. The results show that the transverse magneto-optic error per turn of the miniature photonic-crystal fiber optic gyroscope is ~ 3.5 times smaller than that of the conventional fiber optic gyroscopes. A thinner $\mu $ -metal shield can be used in a miniature photonic-crystal fiber optic gyroscope, resulting in less cost and weight. Meanwhile, the experimental and the calculated results agree well with each other, which illustrates that the transverse magneto-optic error derives mainly from the bend-induced asymmetry distribution of the refractive index in fiber. Considering the remarkable properties of the solid-core photonic-crystal fibers, they are the good candidates for the future miniature fiber optic gyroscopes.