RU2762951C1 - Method for measuring the static capture threshold in a laser angular velocity sensor - Google Patents

Abstract

FIELD: laser equipment.

SUBSTANCE: invention relates to laser equipment, namely, to laser gyroscopy. The method for measuring the static capture threshold in a laser angular velocity sensor includes creation of sign-alternating dithering, extraction and processing of information on the frequency of beats of counterrunning waves, determination of the scale coefficient, determination of the difference in the nonlinear distortions of the scale coefficient, and calculation of the static capture threshold by the formula:

,

wherein Ω_L is the static capture threshold in the laser angular velocity sensor; K₁; K₂; K₃ are the scale coefficients of the laser angular velocity sensor; a, b, c are the coefficients determined based on the approximation of the dependence of the difference in the nonlinear distortions of the scale coefficient on the static capture threshold.

EFFECT: reduction in the time and decrease in the labour intensity of the process of measuring the static capture threshold in a laser angular velocity sensor due to the reduction in the amount of data required for calculation and the automation of the measurement process.

1 cl, 1 dwg, 2 tbl

Description

The invention relates to laser technology, namely to laser gyroscopy.

A known method of measuring the threshold of static capture in a laser sensor of angular velocity, which consists in the imposition of a longitudinal magnetic field on the active medium of the laser, which creates a frequency difference of counterpropagating waves in the absence of rotational motion, equivalent to the angular speed of rotation of the sensor. By measuring the current in the solenoids of a nonreciprocal device when entering the static capture zone, the static capture threshold is determined. [one].

The disadvantages of this method for measuring the static capture threshold in the laser angular velocity sensor are: a large error in the measured capture threshold caused by inaccuracy in determining the minimum current value in the solenoids of a nonreciprocal device, at which the difference in the frequencies of counterpropagating waves disappears and hysteresis phenomena at the entrance and exit of the ring laser from the capture zone ...

The closest in technical essence to the proposed method is a method for measuring the static capture threshold in a laser angular velocity sensor, including creating an alternating frequency bias, extracting and processing information about the beat frequency of counterpropagating waves, and determining the scale factor. The frequency response is obtained from known scale factors for different angular speeds of rotation. The frequency response is approximated using a known theoretical function and, according to one of the parameters of this function, the static capture threshold is determined [2].

The disadvantages of this method for measuring the static capture threshold in a laser angular velocity sensor are: long data collection time required for correct approximation of the frequency response, laborious processing of the data obtained, or the use of specialized software.

The objective of the invention is to reduce the time and reduce the complexity of the process of measuring the static capture threshold in the laser angular velocity sensor by reducing the amount of data required for the calculation and automating the measurement process.

The problem is solved by the fact that in the known method for measuring the static capture threshold in a laser angular velocity sensor, including creating an alternating frequency bias, extracting and processing information about the beat frequency of counterpropagating waves, and determining the scale factor, the difference in the nonlinear distortion of the scale factor is determined and the static threshold is calculated. capture according to the formula (1):

where:

Ω _L is the static capture threshold in the laser angular velocity sensor;

K ₁ is the scale factor of the laser angular velocity sensor at an angular velocity of rotation Ω ₁ , much greater than the angular velocity of rotation Ω ₀ , which coincides with the amplitude of the alternating frequency bias;

K ₂ is the scale factor of the laser angular velocity sensor at an angular velocity of rotation Ω ₂ less than the angular velocity of rotation Ω ₀ , which coincides with the amplitude of the alternating frequency bias;

K ₃ is the scale factor of the laser angular velocity sensor at an angular velocity of rotation Ω ₃ less than the angular velocity of rotation Ω ₂ ;

a, b, c - coefficients determined by approximating the dependence of the difference between the nonlinear distortions of the scale factor on the static capture threshold (2):

These dependences for laser sensors of angular velocity ZLK-20 and ZLK-16 [3], approximated by the relation (2), are shown in the drawing, where:

- разность нелинейных искажений масштабного коэффициента;

- the difference in nonlinear distortion of the scale factor;

Ω _L is the static capture threshold in the laser angular velocity sensor.

As can be seen from this figure, the coefficients a, b, c for laser angular velocity sensors ZLK-20 and ZLK-16 [3] differ significantly from each other by the type of sensor. The values of the coefficients a, b, c are given in table 1.

(на 1 град/сек) и

(на 1 град/сек), где Ω₀ - угловая скорость вращения, совпадающая с амплитудой знакопеременной частотной подставки. То есть должно соблюдаться следующее неравенство угловых скоростей (3):An example of the implementation of the proposed method. The laser angular velocity sensor is fixed on the turntable, the discharge is ignited in the sensor resonator, a longitudinal magnetic field is applied to the active medium of the laser (an alternating frequency bias is created). Then the sensor is rotated on a turntable with angular velocities: Ω ₁ >> Ω ₀ (for example, 400 deg / s),

(by 1 degree / sec) and

(by 1 degree / sec), where Ω ₀ is the angular velocity of rotation, which coincides with the amplitude of the alternating frequency bias. That is, the following inequality of angular velocities must be observed (3):

During the rotation of the sensor, information about the beat frequency of counterpropagating waves is extracted and processed, the scale factors K ₁ , K ₂ , K ₃ are measured, respectively, of the angular velocity, given in Table 2.

Further, the scale factors are used in calculating the static capture threshold according to the formula stated in the method: For ZLK-20 (4):

For ZLK-16 (5):

This method of measuring the static capture threshold in the laser angular velocity sensor allows to significantly (2-3 times) reduce the measurement time, reduce the labor intensity and automate the process of measuring the static capture threshold in the laser angular velocity sensor.

The initial data were obtained as a result of processing statistical information based on a significant number of measurements carried out on serial laser angular velocity sensors.

The reliability of the static capture threshold values, measured by the method described above, is confirmed by tests on commercial laser angular velocity sensors.

Sources of information:

1. A.O. Sinelnikov, E.M. Ermak, A.P. Rusty. Features of frequency capture in a laser gyroscope with a frequency bias on the Zeeman effect. Science-intensive technologies, no. 10, 2012, p. 40-45.

2.S.E. Beketov, A.S. Bessonov, E.A. Petrukhin, I.N. Khokhlov, N.I. Khokhlov. The influence of backscattering on nonlinear distortions of the scale factor of a laser gyroscope with a rectangular support // Quantum electronics, vol. 49, no. 11, 2019, p. 1059-1067. - prototype

3. V.V. Azarova, Yu.D. Golyaev, I.I. Saveliev. Zeeman laser gyroscopes // Quantum electronics, vol. 45, no. 2, 2015, p. 171-179.

Claims (7)

A method for measuring the static capture threshold in a laser angular velocity sensor, including creating an alternating frequency bias, extracting and processing information about the beat frequency of counterpropagating waves, and determining a scale factor, characterized in that the difference in nonlinear distortion of the scale factor is determined and the static capture threshold is calculated using the formula

where Ω _L is the static capture threshold in the laser angular velocity sensor; K ₁ is the scale factor of the laser angular velocity sensor at an angular velocity of rotation Ω ₁ , much greater than the angular velocity of rotation Ω ₀ , which coincides with the amplitude of the alternating frequency bias; K ₂ is the scale factor of the laser angular velocity sensor at an angular velocity of rotation Ω ₂ less than the angular velocity of rotation Ω ₀ , which coincides with the amplitude of the alternating frequency bias; K ₃ is the scale factor of the laser angular velocity sensor at an angular velocity of rotation Ω ₃ less than the angular velocity of rotation Ω ₂ ; a, b, c - coefficients determined by approximating the dependence of the difference in nonlinear distortion of the scale factor on the static capture threshold.

Images