Method for expanding optical fibre gyroscope dynamic range

Abstract

The invention discloses a method for expanding dynamic fiber optic gyro range, the method comprises the steps as follows: an assistant gyroscope is added into the fiber optic gyro which works independently originally; the measurement of angular rate is divided into the measurement of the angular rate in the single-valued range of the fiber optic gyro and the measurement of the ordinal number of the single-valued range, the measurement of the angular rate in the single-valued range is realized by the fiber optic gyro, while the output of the assistant gyro is treated with quantized treatment, the integer after the quantized treatment is the measured value of the ordinal number of the single-valued range; the two measurement results are treated with data fusion, and the practical value of the angular rate is obtained and used as the new output of the fiber optic gyro, the new output expands the original dynamic range which can be measured by the fiber optic gyro. By reasonably combiningthe advantage of a microgyro of measuring large angular rate with the high static property of the fiber optic gyro, the method realizes the aim of expanding the measurement of the angular rate on the basis of keeping the static precision, meets the requirements of the guidance and navigation of a high mobility carrier, and has low cost, high benefit and popularization and application value.

Description

technical field [0001] The invention relates to a processing method for improving the dynamic performance of a system in an optical fiber gyroscope sensor, in particular to a method for expanding the dynamic range of an optical fiber gyroscope. Background technique [0002] Fiber optic gyroscope is a new type of angular rate measuring instrument. It is widely used in navigation and attitude control systems due to its advantages of all solid state, wide bandwidth and digital output with multiple protocols. The working principle of the fiber optic gyro is a fiber optic interferometer based on the optical Segneck effect, that is, when the ring interferometer rotates, a Segneck phase difference proportional to the rotation angular rate is generated. By detecting the phase difference, it can be calculated The angular rate of the system in which the ring interferometer is located. Segneck phase shift φ Sag . The relationship with the system angular rate Ω is as follows: [000...

AI Technical Summary

Problems solved by technology

If it is necessary to expand the dynamic range and measure a larger range of angular rates, it is necessary to reduce the length of the optical fiber or the diameter of the ring, and too small a ring diameter will increase the bending loss of the system and reduce the detection signal-to-noise ratio, thus weakening the output angular rate signal of the fiber optic gyroscope The accuracy of the static accuracy deteriorates, that is, the minimum measurable angular rate. This method of extending the dynamic range reduces the measurement accuracy at the expense of

[0005] The micro-gyroscope is a gyroscope based on micro-processing technology. It benefits from the large-scale integrated circuit processing technology, small size, low power consumption, and large measurement range. The existing tuning-fork micro-gyroscope can measure angular rates up to 6000° / s. But its static measurement accuracy is poor, the typical value is in the order of ° / s, which is more than 3 orders of magnitude larger than that of the fiber optic gyroscope; such as the micro gyroscope of Analog Company, the typical static accuracy is between 0.1° / s and 1° / s, The typical value of the static accuracy of the fiber optic gyroscope is 0.1° / h, and the micro-gyroscope is thousands of times that of the fiber-optic gyroscope. Therefore, the micro-gyroscope is generally used in low-precision applications and cannot be used in navigation and guidance systems that require high static accuracy.

[0006] In some navigation and guidance application systems, the system carrier is a high-mobility carrier. For the angular rate sensor used, it is required not only to be able to measure a large angular rate range, but also to have high static measurement accuracy. For example, it can measure angles up to 1500° / s It has a static accuracy of less than 0.01° / h, and its measurement range spans 8 to 9 orders of magnitude. It is difficult for existing gyroscope technology, including fiber optic gyroscopes, to take into account such a large measurement dynamic range. As mentioned above, it is generally through Sacrificing static accuracy to obtain a large measurement range does not really improve the dynamic range. A new method is needed to effectively expand the dynamic range of angular rate measurement without reducing the static accuracy, so as to meet the application of high-mobility motion carriers need

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