Fiber Optic Gyro Technology Research Articles

Analyze the Difference Between Rotational and Translational Motions Produced by High-speed Train

The development of fiber optic gyroscope technology makes it possible to directly measure the rotational ground-motion. The joint observation of the three-component rotational seismometer and the traditional three-component translational seismometer is a trend of future. In this paper, the translational and rotational signals generated during the high-speed trainway are studied, and the three-component translational and rotational seismometers are fixed together to realize the joint recording of the high-speed trainway signal. Comparing the translational and rotational three-component data, we find that only one component waveforms and the spectrum have certain consistency. However, the difference between them indicates that the rotation and translation signals generated by the shallow surface wave signal have different frequency bands.

Systematic Measurement of Temperature Errors of Positive and Negative FOG Scale Factors Using a Low-Precision Turntable

Measurement of temperature errors of fiber optic gyro (FOG) scale factor is important in FOG technology. In traditional methods, the measurement errors of FOG scale factors are greatly affected by the turntable’s orientation control errors. This article proposes a systematic method to measure the positive and negative FOG scale factor errors using a low-precision turntable. The relationship between the inertial navigation errors and the complete inertial measurement unit errors is revealed. A simplified tracking algorithm is devised to obtain the change rates of the velocity errors with lower computation. A measurement procedure is designed, with three groups of π and -π rotations around the east axis of the turntable at each temperature. Observation equations are derived to estimate the positive and negative FOG scale factor errors. Simulation and experimental results show that a low-precision turntable can accurately measure the FOG scale factor errors at each temperature. Furthermore, temperature errors of accelerometer biases, scale factors, and nonlinear scale factors can also be measured at the same time using the rotation sequences and formulas in this article without additional rotations.

Eigen frequency measurements of a fiber optic gyroscope based on a staircase waveform with large temperature range.

The eigen frequency is a key parameter of a fiber optic gyroscope (FOG). We present an online eigen frequency tracking method for FOG technology based on the staircase waveform and a four-step frequency perturbation. Results show that the measurement accuracy of the eigen frequency does not exceed 1.7Hz for a temperature range of 27.5°C-62.5°C and a variation rate of 0.24°C/min. This is in good agreement with the theoretical model. The method, which exhibits a low time-space complexity, simply requires the addition of a low-rate digital-to-analog converter to the existing gyro system. There is no requirement for the type of staircase waveform in the phase modulation, and the staircase waveform remains unchanged. Thus, this method can be easily transplanted into other algorithms.

Interferometric Fiber Optic Gyro Technology (IFOG)

Life cycle cost containment of the Strategic Weapons System (SWS), without loss of ultra high performance, is a very important goal of the entire Navy Strategic Systems Program community. Boeing is responding by guiding large advances in the state-of-the-art of fiber optic gyro technology and developing a new associated navigation system. All of the very stringent Strategic Weapons System (SWS) performance, reliability, and maintainability requirements continue to be exceeded by the Electrostatically Supported Gyro Navigator (ESGN). The Electrostatically Supported Gyro (ESG), in production for over 25 years, is the most critical and costly component of the current inertial navigation system. ESGs, however, are extremely expensive to manufacture and repair. Furthermore, the system-level electronic components are difficult to replace because they are rapidly becoming obsolete. The current initiative is focused on containing total ownership costs, especially maintenance costs, without any relaxation of performance, reliability, or maintainability requirements. The key element of this initiative is new gyro technology based on rapidly improving precision Interferometric Fiber Optic Gyro IFOG performance, along with cost reduction of fiber and manufacturing processes. This paper discusses the challenges and the approach currently being taken to further the development of high precision IFOG technology and its associated inertial navigation system for application to the SSBN.

Topical Papers on Progress in Fiber-Optic Gyro Technology

Topical Papers on Progress in Fiber-Optic Gyro Technology

Utilization of Fiber Optic Gyros in Inertial Measurement Units

Fiber optic gyro technology has been developed to a point where these gyros are now being introduced into advanced engineering models of the next generation of inertial measurement units (IMUs). This paper covers the operating principles of the interferometric type of fiber optic gyroscopes, together with a brief comparison against ring-laser gyroscopes. Recent flight test data of an IMU employing fiber optic gyro sensors are presented. Finally, the unique characteristics of the fiber optic gyro are discussed, with particular emphasis on the role they will play in future fault-tolerant IMUs.

Test Results of Prototype Fiber Optic Gyros

Fiber Optic Gyro performance has progressed sufficiently to allow production engineering for several applications. Data from a prototype gyro are presented showing a stable bias (< 0.1 deg/h) over 0 to 40 °C environment with low random noise (0.006 deg/√h) and modest open-loop scale factor stability (0.2 percent). The low power consumption, light weight, and potential for low cost and high reliability of Fiber Optic Gyro technology make it ideal for many applications. Research and development is ongoing to improve scale factor stability to the ppm range. A brassboard closed-loop gyro with 30 ppm scale factor accuracy is described.