RU1838760C - Method of determination of heading correction of two-mode single-gyroscope course indicator - Google Patents

Abstract

The invention relates to the field of navigation instrumentation and can be used to determine the course correction of dual-mode single-gyro direction indicators, in particular, gyroazimuth compasses and gyroazimuth horizon compasses. The aim of the invention is to increase the accuracy of determining the course correction of a two-mode single-gyro guidance indicator while reducing its determination time. The proposed method for determining the course correction of a two-mode single-gyro course indicator includes starting the course indicator and holding it for a time, ensuring the achievement of a steady electric and thermal state, turning on the gyro azimuth mode with a control moment along the vertical axis of the gyroscope suspension proportional to the deviation of the main axis of the gyroscope from the horizon, orienting the main axis of the gyroscope in an arbitrary sequence east and west, fixing in each of these orientations tion, the main values of established deviations of the gyro axis from the horizontal and defining a constant rate as the arcsine correction by dividing the measured horizon indicator readings on the difference of these readings. ё

Description

The invention relates to the field of instrumentation and can be used to determine course correction. dual-mode single-gyro course indicators.

The aim of the invention is to improve the accuracy of determining the constant course correction of a dual-mode gyro pointer while reducing its determination time.

This goal is achieved in that in the method of determining the constant correction

the course of the dual-mode gyro-pointer, including starting the gyro-pointer and holding it for a time, ensuring the achievement of a steady electric and thermal state, after this exposure, the gyro-azimuth mode with a control moment along the vertical axis of the gyroscope proportional to the output of the horizon indicator is turned on. In the gyro azimuth mode, the orientation of the main axis of the gyroscope in

00 w 00

4J o o

with

arbitrary sequence to the East and West.

In each of the two indicated orientations, the steady-state value of the output signal of the horizon indicator is measured and the constant course correction is determined as the arcsine of the partial of dividing the sum of the measured readings of the horizon indicator by the difference of these readings, taken in the order in which the main axis of the gyroscope was oriented .

The theoretical justification of the proposed method for determining the constant correction rate of the dual-mode gyro course indicator is as follows.

Giving the gyro course indicator the selectivity to the direction of the true (geographical) meridian in the gyrocompass mode and the ability to maintain the specified azimuthal direction in the gyro azimuth mode is achieved by the corresponding formation of control moments. In the gyrocompass mode, according to the indications of the horizon indicator (accelerometer) /, the satellite Kx / and damping Kz / J moments are formed simultaneously, applied along the horizontal and vertical axis of the gyroscope, which gives it the properties of a gyrocompass. In the gyro azimuth mode, according to the indications of the horizon indicator, the moment Kz / J is applied only to the vertical axis, the horizontal of the gyroscope. In both modes, according to the latitude of the place and speed of the object relative to the Earth, the moments of latitudinal and speed correction are also formed.

The equations of motion of the gyroazimuth compass on a fixed base under the assumption that the angle of rotation of the axis of the gyroscope in azimuth is unlimited, and the angle B of the elevation of the axis of the gyroscope above the horizontal plane can be represented as:

M2corr MX corr — correction moments on the vertical and horizontal axes of the gyroscope, respectively;

MGkomp, Mkhkomp - moments of compensation

constant constituents of harmful moments on the vertical and horizontal axes of the gyroscope, respectively;

Mx, Mz are harmful moments on the vertical and horizontal axes of the gyroscope, respectively.

The presence of harmful moments in the axis of suspension of the gyroscope leads to instrumental errors in determining the geographic meridian in the gyrocompass mode and inaccuracies in the storage of the azimuthal direction in the gyro azimuth mode. The constant component of harmful moments on the horizontal axis of the gyroscope is compensated by the moment Mx in the gyro azimuth mode, eliminating the visible azimuthal deviation, which differs from the vertical component of the Earth's rotation speed Usln f. After that, the moment of latitudinal correction is compensated

the vertical component of the Earth's rotation speed, eliminating the apparent azimuthal departure completely. The influence of the constant component of harmful moments along the vertical axis of the gyroscope on the error in determining the geographical meridian in the gyrocompass mode is expressed by the well-known formula at small angles:

Yes

 No.

H U cozy

(3)

Mz Mz + MzK

40

or in the final corners

D "arcsin

Mf

N u costp

(4)

H (/ 3 + Ucos (a) - K2B + MZKOPP + MzK0

+ M2

(1)

-H (a + Usiny -ft Ucos p cos a) Kx / 3 + MXKOPP + MXComp + Mz (2)

where a, ft are the angles of deviation of the gyroscope axis from the meridian in the horizontal plane and from the horizon plane, respectively;

H - own kinetic moment of the gyroscope;

U is the Earth's rotation speed;

Uz-latitude of the place ;,

where Yes is the error in determining the direction of the geographic meridian;

Mz is a constant component of uncompensated harmful moments on the vertical axis of the gyroscope.

Therefore, the constant component of harmful moments on the vertical axis of the gyroscope — the main source of instrumental errors in the gyrocompass mode — is eliminated by measuring

of the stationary correction is the difference between the equilibrium position in the gyrocompass mode and the direction of the geographic meridian.

In the regime of gyro azimuth, the constant component of the uncompensated harmful moment on the vertical axis of the gyroscope leads to the appearance of an additional contribution proportional to its value to the steady reading of the horizon indicator. For arbitrary orientation of the gyroscope in azimuth in the steady state, equation (1) implies the equality

Kz / -HUcosy5slna + Mz, (5)

or d - HUcos psing, Mz, s.

P - --Ј-7 KG; (6)

where / is the angle of elevation of the kinetic moment of the gyroscope over the horizon plane in the steady state;

Kz is the steepness of the horizontal correction moment.

In the proposed method for determining the constant correction to eliminate the requirements for the exact determination of the angle a, the steady-state indicator of the horizontal indicator is measured with the gyro axis oriented to the East (course 270 ° degrees) or approximately West (course 90 ° degrees). In this case, the error in the azimuthal orientation of the gyroscope or its change during operation, even in units of degrees, does not lead to a noticeable violation of the balance of members in expression (3) (cos 90 ° 1.0000; cos 89 ° 0.9998; cos 88 ° - 0 9994 etc.). The use of any other azimuthal orientation would require precise alignment of the gyroscope with the geographic meridian direction. In the proposed method, measurements are made of the steady-state readings of the horizon indicator in two orientations / gyroscope in an arbitrary sequence:

1) with the orientation of the axis of the gyroscope to the East (course 270

„, HUcos CHI

and - T -------- 7f.

Kg

(7)

2) with the orientation of the axis of the gyroscope to the West (90 ° course).

  HUcos- (8) V

I.

| According to the results of these measurements, | This correction can be determined from j expressions (4), (7), (8), as the inverse trigonometric function (arcsine) of the quotient of

dividing the sum of the established indications of the horizon indicator in the eastern and western orientations by their difference in the same order

Aa arcsin

& + AV,

9)

Consider an example of a specific implementation of the method

The gyroazimutcompass in the gyrocompass mode came to the compass meridian. Then, in the gyro azimuth mode, the axis of the gyroscope was oriented eastward

4 min time Using a digital voltmeter, a steady reading of the horizon indicator was measured for 4 ... 6 minutes. Then, the gyro was oriented to the West for 8 minutes.

Using a digital voltmeter, a steady reading of the horizon indicator was measured for 6 ... 8 min. Further, a constant correction of the gyroazimuthcompass rate in the gyrocompass mode was determined

by the formula (8). The direction of the true meridian was determined as the sum of the compass meridian and the constant correction in this launch. The experiments were carried out with two gyroscopes. Between starts, constant correction was compensated by the additional current of the gyroscope torque sensor. In all launches, the body of the gyroazimuth compass maintained a constant orientation relative to the stationary

bases.

According to the results of experiments, the high efficiency of the proposed method was established. The time for determining the constant correction was from 23 to 24 minutes.

Time for determination of the constant correction of the serial gyroazimuth compass Vera-M BaO. 115.001TU using the proposed method was reduced from 12 hours to 40 minutes

In both cases, the error in determining the constant correction of the heading indicator when implementing the proposed method was less than the price of dividing the heading scale of 0.1 degrees.

Using the proposed method

constant rate correction

dual-mode gyro-pointer allows compared with the prototype sharply

reduce the time to determine the correction (in

20 times or more), to increase the accuracy of determining the correction. In a particular embodiment of the method, the error in determining the constant correction was less than the price of dividing the rate scale. Using

The proposed method eliminates the need for using external remote reference points, in the high-precision determination of their true bearings, and the dependence of the possibility of determining a constant correction on weather conditions is excluded.

The proposed method can be applied with equal success both in the conditions of the manufacturer and at the facility.

The application of the proposed method allows, in comparison with the prototype, to significantly increase the instrumental accuracy of the gyro course indicator, especially when swimming in high latitudes.

Claims (1)

Formula of the invention Method for determining course correction a dual-mode single-gyro course indicator, including starting the course indicator and holding it for the time of precision readiness, and so on, in order to increase the accuracy of determining the correction while reducing its time determination after said extract additionally in gyro azimuth mode form the control moment by. the vertical axis of the gyroscope is proportional to the main axis of the gyroscope and is aligned with the horizon, the main axis of the gyroscope is oriented east and west, the deviation of the main axis of the gyroscope from the horizon is fixed in each of these orientations, and the course correction is determined as the arcsine of the quotient from the division the sum of the values of the indicated deviations to their difference.