RU2610022C1 - Stabilised gyrocompass system - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: stabilised gyrocompass system contains a vertical angular velocity sensor, a coordinate converter, and a yaw rate sensor consisting of the first integrator, the adjustable link and the second integrator, a closed loop of the stabilised gyrocompass system with the first pitching angles located at the output of the second integrator. The second output of the Earth rotational speed projection signal is inserted into the circuit of the stabilised gyrocompass system located between the adjustable link and the second integrator. A new closed loop of the derived calculation from the Earth's rotation speed projections is inserted into the stabilised gyrocompass system, and consists of the series-connected adders, an azimuth unit, a unit of filters and derivatives. The second circuit output of the stabilised gyrocompass system through the adder is connected with a new circuit of the derived calculation from the Earth's rotation speed projections. The filter parameters in the new circuit are set so that the useful output signal of the adder is independent from them. The unit of the derivatives is connected to the vertical angular velocity sensor, the azimuth unit output is an azimuth output of the stabilised gyrocompass system and is connected to the input of the coordinate converter. Two other input converters are connected to the first output circuit of the stabilised gyrocompass system and the course angle sensor, the output of the coordinate converter is the output of the stabilised gyrocompass system by course.

EFFECT: improved accuracy of the instrument azimuth generation and the object course, excluding the amplitude and phase distortion inserted by the filters.

1 dwg, 3 tbl

Description

The invention relates to the field of navigation, in particular to gyrocompasses, and is intended to improve the accuracy of determining the course.

Gyrocompasses are known with bringing the kinetic moments of gyroscopes into the meridian plane [1]. Such gyrocompasses have large dimensions and weight.

With the advent of accurate angular velocity sensors (DOSs), gyrocompasses appeared with tracking the minimum value of the eastern component of the Earth's rotation speed [2]. Their disadvantage is the limitation of accuracy with their own departures of gyroscopes.

The drift of gyroscopes is separated from the useful signal by auto-compensation by a limited rotation of the sensitive elements [3] or their unlimited rotation [4].

The disadvantage of the “Girohorizontkompasa” adopted as a prototype [4] is the excessive connection of the vertical channel with the azimuth channel. The gyrohorizon is a link in the azimuth channel, and, therefore, its output signal depends on the parameters of two filters. This leads to a loss of accuracy due to signal distortion by the filters of both channels and to the complexity of their optimal choice.

The aim of the invention is the creation of gyrohorizon compass, in which the determination of the azimuth is carried out without amplitude and phase distortion introduced by the filters.

The known gyrohorizon compass contains a vertical angular velocity sensor, a coordinate transducer, a heading angle sensor, and consisting of a first integrator, an adjustable link and a second integrator, a closed gyrohorizontal circuit, the output of which at the pitch angles is located between the second and first integrators. This goal is achieved by the fact that the second output located between the adjustable link and the second integrator is introduced into the gyrohorizon by the signal of the projections of the Earth's rotation speed, and a new closed loop for calculating the derivatives of the projections of the Earth's rotation speed is introduced into the gyrohorizontal compass. The derivative calculation loop consists of a series-connected summing device, an azimuth block, a derivative block, and a filter. A new circuit is connected via a summing device to the second output of the gyro horizon. The filter parameters are set so that the useful signal at the output of the summing device is independent of them. The derivative block is connected to a vertical angular velocity sensor. The output of the azimuth block is the azimuth gyrohorizon compass output and is connected to the input of the coordinate transformer, the other two inputs of which are connected to the first gyrohorizon horizon output and the course angle sensor. The output of the coordinate converter is the output of the gyrohorizon compass.

The technical effect is to increase the accuracy of the production of instrument azimuth and the course of the object.

The gyrohorizon compass device is shown in FIG. 1. It depicts the following elements: 1 - contour gyrohorizon,

2, 3, 4, 5, 6 - sources of information: 2 - accelerometers (ACS), 3 - sensors of horizontal components of angular velocity (ДУС), 4 - linear velocity sensor - satellite navigation system (SNA), 5 - vertical angular velocity sensor (ДУСв), 6 - heading angle sensor q

, 9 - регулируемое звено с передаточной функцией

,10, 11, 12 - масштабирующие устройства: 10, 11 - с коэффициентом передачи

, 12 - с коэффициентом передачи

, g, R - ускорение свободного падения и радиус Земли соответственно.7, 8, 9 - links of the circuit: 7, 8 - first and second integrators with transfer function

, 9 - an adjustable link with a transfer function

, 10, 11, 12 - scaling devices: 10, 11 - with transmission coefficient

, 12 - with transmission coefficient

, g, R - gravity acceleration and the radius of the Earth, respectively.

13, 14 - inputs of the gyrohorizon circuit according to the signals of the ACS and TLS, respectively,

15, 16 - inputs of the gyrohorizon contour according to the SNA signal,

17 - output contour gyrohorizon at the pitch angles α, β,

18 - output contour gyrohorizon horizontal projections of the speed of rotation of the Earth,

19 - contour of the derivatives of the projections of the speed of rotation of the Earth,

20 is a summing device,

21 - block azimuth

22 - block derivatives

23 - filter

24 - exit gyrohorizontkompasa in azimuth.

25 - coordinate converter (PC).

The gyrohorizontcompass contains a closed gyro-vertical circuit 1 and information sources: 2 - accelerometers, 3 - sensors of horizontal components of angular velocity, 4 - sensors of linear velocity, 5 - sensor of vertical component of angular velocity, 6 - heading angle sensor. The gyro-vertical circuit consists of a first integrator 7, a second integrator 8 and an adjustable link 9 located between them. Information signals are scaled: the accelerometer signal on the device 10, and the linear speed sensor (SNA) signal on the devices 11, 12. The circuit has four inputs: 13 - according to the signal of the accelerometers, 14 - according to the signal of the horizontal angular velocity sensors, 15 and 16 - according to the signal satellite navigation system, and two outputs: 17 - on pitching angles and 18 - on horizontal projections of the Earth's rotation speed. The gyro vertical is connected to the contour of the derivatives of the projections of the rotation speed of the Earth 19 through the summing device 20, which is part of a ring of series-connected azimuth blocks 21, the derivatives block 22 and the filter 23, which closes the ring by connecting its output to the input of the summing device. The derivative block is connected to a vertical rotation sensor. Output 24, located between the azimuth and derivative blocks, is the azimuth gyrohorizontal compass output and is connected to the coordinate transformer 25, the other two inputs of which are connected to the gyro vertical output by pitching and the heading angle sensor. The output of the coordinate converter is the output of the gyrohorizon compass at the heading.

, а ошибка его производной - на полосовом фильтре

:The universal property of circuit 1 is that if a useful signal, for example, a pitching angle, with an error α + Δ _{1 is} applied to its input 13, and a derivative of the same signal, with a different error pα + Δ ₂ , is fed to input 14, then the signal at the output 17 - W _1.1 will contain a signal that is invariant to the transfer function H, in particular, the pitch angle α. Signal error filtered on low pass filter

, and the error of its derivative is on a band-pass filter

:

Consider the operation of the gyrohorizon scheme. We assume that information sources measure the following signals

where V is the linear velocity of the ship over the Earth’s surface, Ω is the angular velocity, α are the pitching angles, ω _Зг are the horizontal components of the Earth’s rotation speed, and _pu are the portable pitching accelerations, Δа _ACS , Δ _TLS , ΔV _SNA are the errors of the corresponding sensors.

,

и масштабирования на входы контура 1 поступят сигналы:After replacing variables

,

and scaling the inputs of circuit 1 will receive signals:

- квадрат постоянной времени М. Шулера.Where

- the square of the time constant M. Schuler.

The output signals of circuit 1 are written in general form:

After substituting the input signals, we obtain

The useful signal of output 17 is invariant to the transfer function H. The circuit with this output is a gyro-vertical that is not disturbed by linear accelerations of maneuvering - pV.

The circuit with output 18 is a meter of horizontal components of the angular velocity of rotation of the Earth - ω _ЗГ , not disturbed by linear accelerations and pitch angles.

The SNS signals compensate for the signals generated by the ACS and TLS for the speed of the ship on the Earth's surface, ensuring the unperturbability of both outputs.

Consider the most general form of the transfer function of the adjustable link 9, without imposing any restrictions on it, except for the requirement to ensure the stability of the circuit

where: T _to - time constant, type-exponents, G _n and Q _m - polynomials of degrees pit, respectively, with single free terms:

The transfer functions of the circuit will have the form shown in Table 1. The table shows the general view of the functions and the form they acquire at high frequencies ω → ∞ and at low frequencies ω → 0.

For example, table 2 shows the transfer functions of the third-order circuit.

Table 3 shows the level of error suppression depending on the degrees n and m. In this table, the vibrations of the dynamic vertical α _{pu are} conditionally assigned to high-frequency errors, and the remaining errors to low-frequency ones.

The low-frequency error is suppressed due to differentiation, the frequency of which is given in the table, and the high-frequency error due to integration, the frequency of which is also given in the table. The table shows that to reduce the error in the design of the gyrohorizontal, it is desirable to increase m and n, and when developing a measuring instrument for the angular velocity of rotation of the Earth, it is advisable to increase n.

, исключаются при однократном или двукратном дифференцировании. В результате на втором выходе получим сигналAt the output 18, by choosing the order of n, the high-frequency error can be made negligible, the error of the accelerometer and the error of the SNA containing the factor

are excluded with single or double differentiation. As a result, we get a signal at the second output

Using auto compensation [4], we separate the gyro drift from the useful signal and obtain

вносит амплитудные и фазовые искажения в измерения. Выражение (9) можно раскрыть в проекциях на приборные оси X, YThe error Δ _{SNS is} not amenable to either filtering or auto-compensation. At the same time, the transfer function

introduces amplitude and phase distortion into the measurements. Expression (9) can be revealed in projections on the instrument axes X, Y

where: A - azimuth of the platform

Δ _snsh , Δ _snsu - SNA errors in projections on the instrument axes,

- модуль,

- module

- ошибка по фазе, вносимая сигналом СНС.

- phase error introduced by the SNA signal.

In order to exclude the dependence on the transfer function, it is possible, by analogy with (1), to construct a circuit 19, in which block 22 generates signals of derivatives:

, то на его выходе получимIf the filter 23 set the transfer function

then on its output we get

When adding in the adder 20 the signal at the output of the filter with the output signal 18 of the horizontal horizon, we obtain a signal that is invariant to the transfer function.

Based on these signals, the azimuth and module are calculated in the azimuth block 21

Independent of the transfer function, the signal A + ε is fed to the output 24 of the azimuth circuit 19 and at the same time to the derivative block 22. The signal of the azimuth rate of change with the corresponding error is sent to the same block from the vertical angular velocity sensor 5

, и на его выходе получимAs a result, functions (11) are generated, which are transmitted to the filter 23 in a cycle. A transfer function is formed in the filter

, and at its output we get

, вносимых датчиком вертикальной угловой скорости 5.Expressions (16) differ from formulas (12) by the presence of an error

introduced by the vertical angular velocity sensor 5.

Turning to table 1, we can conclude that with a high order m at the output of the filter 23, the error from the drift of the vertical gyroscope will be arbitrarily small due to the multiple differentiation of the low-frequency signal.

Ultimately, at the output 24 of circuit 19, we obtain the azimuth with the only significant error due to an error in measuring the speed of the SNA.

For example, with ΔV _CHC = 0.2 m * s ^-1 , ϕ = 60 °, the error will not exceed ε = 10 ^-3 = 3 angles. min

Based on the azimuth A obtained in block 21, the pitch angles α, β coming from the output of the gyrohorizon 17, and the heading angle q generated by the sensor 6, the K course is calculated in the coordinate transformer 25, for example, by the formula

where Q is the heading angle in the instrument horizontal coordinate system is calculated from the equation

where Ψ, θ is keel and roll.

The course K from the output of the coordinate transformer goes to the consumer.

Improving accuracy is achieved by reducing errors when increasing the order of the filters and eliminating the amplitude and phase distortions introduced by the filters.

Information sources

1. Rivkin S.S. Theory of gyroscopic devices. Part 2. Shipbuilding. L., 1964, p. 379-435.

2. Application CN 204177391. Marine gyrocompass control device. Priority date 2014-11-11.

3. Patent RU No. 2550592. Gyrohorizontcompass.

4. Ignatiev S.V. Girogorizontkomas on fiber-optic gyroscopes with rotation of the block of sensitive elements. Navigation and traffic control. Sat reports of the IV conference of young scientists. SPb .: SSC RF Central Research Institute Electropribor, 2002, p. 291-298.

Claims (1)

A gyrohorizontcompass containing a vertical angular velocity sensor, a heading angle sensor, a closed gyrohorizontal circuit, consisting of a first integrator, an adjustable link and a second integrator with a first output at the pitch angles located at the output of the second integrator, and a coordinate transformer, two inputs of which are connected to the first output the contour of the gyrohorizon and the heading angle sensor, characterized in that a second output is inserted into the circuit of the gyrohorizon located between the adjustable link and the second integrator by the signal the projections of the Earth’s rotation speed, and a new closed loop for calculating the derivatives of the projections of the Earth’s rotation speed has been introduced into the gyrohorizontal compass, consisting of a summing device, an azimuth block, a derivative block and a filter connected in series, the second output of the gyrohorizon circuit through a summing device is connected to a new calculation circuit of derivatives of projections of the Earth's rotation speed, the filter parameters are set so that the useful signal at the output of the summing device is independent of them, the block of derivatives with union of a vertical angular velocity sensor, an azimuth output unit is an output girogorizontkompasa azimuth and connected to the third input coordinate converter output is the output of the coordinate converter girogorizontkompasa Exchange.

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