Assessment method for optimal installation configuration of inertial measurement unit with two-frequency mechanically-dithered laser gyroscopes

Abstract

The invention discloses a dithering sensitivity-based assessment method for the dithering sensitivities of two-frequency mechanically-dithered laser gyroscopes, and belongs to the field of inertial navigation, guidance and control. The method comprises the steps that 1, the target dithering amplitudes of the two-frequency mechanically-dithered laser gyroscopes are set; 2, the driving voltage of the two-frequency mechanically-dithered laser gyroscopes is collected; 3, the actual dithering amplitudes of the two-frequency mechanically-dithered laser gyroscopes are collected; 4, the dithering sensitivities of the two-frequency mechanically-dithered laser gyroscopes installed on an inertial measurement unit under the different installation configurations are calculated; 5, the dithering sensitivities of the two-frequency mechanically-dithered laser gyroscopes under the different configurations are compared, and then the optimal installation configuration scheme of the inertial measurement unit with the two-frequency mechanically-dithered laser gyroscopes is obtained. When the method is used for designing the inertial measurement unit composed of the two-frequency mechanically-dithered laser gyroscopes, the configuration scheme with the most suitable dithering frequency and installation positions is selected, it is guaranteed that the inertial measurement unit can work in the best state, the using precision of the two-frequency mechanically-dithered laser gyroscopes is improved, and the service life of the two-frequency mechanically-dithered laser gyroscopes is prolonged.

Description

technical field [0001] The invention relates to an evaluation method for optimal installation and configuration of a two-frequency machine-jittered laser gyro inertial measurement unit based on shaking sensitivity, and belongs to the field of inertial navigation, guidance and control. Background technique [0002] The laser gyroscope is a device for measuring angular rate and angle based on the Sagnac effect and composed of a ring laser resonator. Among the error sources of laser gyroscopes, the region-locking effect is one of the main error sources that limit the practical application of laser gyroscopes. The lock-in effect refers to the phenomenon that the output of the laser gyroscope is zero under the condition of low input angular rate. There are many ways to overcome the lock-in effect, such as rate bias, mechanical jitter bias, Zeeman bias, magnetic mirror bias and Faraday bias, etc. The basic idea is to make the working state of the laser gyroscope quickly cross the...

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Problems solved by technology

The disadvantage of the digital jitter control system of square wave jitter is that square wave jitter has rich high-order harmonics, which can easily interfere with other circuits

[0007] However, the above-mentioned documents all start with the shaking control of a single two-frequency machine-jittered laser gyroscope, aiming at how to make the mechanical shaker frequency bias mechanism of the two-frequency machine-jittered laser gyroscope work in a normal state

In the actual construction of a two-frequency machine-jittered laser gyro strapdown inertial navigation system, the two-frequency machine-jittered laser gyroscope is always installed on the same mounting base in the inertial measurement unit, and usually three orthogonal installations or three More than two redundant installations, in this way, the high-frequency angular vibrations of the mechanical vibration bias mechanism of each two-frequency machine-jitter laser gyroscope will excite each other to generate coupling vibration, and at the same time, the high-frequency angular vibration of the mechanical vibration bias mechanism of the two-frequency machine-shake laser gyro The frequency angular vibration will also excite the installation base to generate coupling vibration. When these coupling vibrations are large, that is, when the shaking frequency of any second-frequency machine shake laser gyro is similar to the natural frequency of the installation base, it will cause the second-frequency machine The shaking drive signal of the shaking laser gyro becomes larger, and when the shaking driving signal reaches the set upper limit and still cannot work normally, it will even damage the mechanical shaking bias mechanism of the second-frequency machine shaking laser gyro, reducing the use of the second-frequency machine shaking laser gyro life

[0008] In order to better apply the high-precision and cost-effective product of the two-frequency machine-dithered laser gyroscope to a wider range of fields, especially the fields that have special requirements for volume and weight and are relatively sensitive to vibration and noise, it is necessary to have a An overall evaluation method for the optimal installation and configuration scheme of the inertial measurement unit composed of a two-frequency machine-jittered laser gyroscope, so as to solve the problem of long-term working reliability and accuracy reduction of the inertial navigation system caused by arbitrary installation or installation based on experience alone. question

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