DE3131111C2 - Gyro device for determining the north direction - Google Patents

Abstract

In the case of a tape-hung meridian gyro, the deflection α ↓ A of the gyroscopic twist axis is tapped from a housing reference by a tap and the tap signal is sent to a torque generator via a high-gain amplifier. This acts around the vertical axis on the meridian gyro and ties it to the housing reference. A Kalman filter (52) is provided, which simulates the system of the tethered meridian gyro. The difference between the signal Mg applied to the torque generator and an estimated value M g of this signal supplied by the Kalman filter (52) is applied as the filter input signal to the Kalman filter (52).

Description

value Mg of the signal switched to the torque generator (24),
(m) The sum formed in the sixth summing point (84) is integrated by integration means (96), as a result of which said estimated value Mg of the signal (Mg) connected to the torque generator (24) is obtained.

4. Gyroscope according to Claims 2 and 3, characterized in that

(n) in the second summing point (58) additionally the fiiit a zcitHuiiangigen ι an.tor λ ₂ ι rnuitized second filter input signal 'is added,

(o) In the fourth summing point (70) the second filter _{input signal multiplied by a time-dependent factor X n is added,}

(p) by the integration means (80), which _{supply an estimated value & 0 of} the angle between the device reference O) and north, the second filter input signal multiplied _{by a time-dependent factor AT 31 is also integrated and}

(q) In the sixth summing point (84), the second filter input signal multiplied by a time-dependent factor K _{41 is added.}

5. Gyroscope according to claim 4, characterized in that

(r) to form the first filter input signal in an eighth summing point (106) ai ". Sum is formed by

(r,) the signal Mg actually applied to the torque generator (24),

(T ₂ ) with a negative sign, the estimated value Mg supplied by the Kalman filter (52) of this signal applied to the torque generator (24) and

(r ₃ ) a signal which represents the variance of the measurement noise process of the signal applied to the torque generator (24), and
(s) to form the second filter input signal in a seventh summing point (108) the sum is formed from

(51) the signal a _A supplied by the tap (20) and representing the deviation of the meridian gyro (12) from the housing reference (y) ,

(5 ₂ ) with a negative sign, the estimated value a _A supplied by the Kalman filter (52), this signal representing the deviation of the meridian gyro (12) from the housing reference; z (y) and

(5 ₃ ) a signal which contains the variance of the measuring and Rausc'uyrozesses of the deviation of the meridian gyro (12) from the housing. The invention relates to a gyro device for determining the north direction

(a) a ίο meridian spinning top suspended in a housing,

(b) a tap that points to the deflection of the meridian gyro responds to a housing reference,

(c) a torque generator that

(C ₁ ) around the vertical axis on the meridian top

acts and

(C ₂ ) is acted upon by the signal of the tap in the sense of a fettering of the meridian circle to the housing reference, and
(d) a signal evaluation circuit, v'o

(d 1) from the one on the. Torque generator connected signal is applied,
(d ₂ ) a filter for suppressing interference

contains and

(d ₃ ) a filtered signa! delivers which the

Represents deviation of the housing reference from north.

DE-PS 19 41 808 is a gyroscope for Determination of the north direction with a meridian gyro suspended from a tape in a case known, in which a tap for generating a signal in accordance with the azimuth deflection of the Gyro opposite one of the

J5 housing reference is provided. A torque generator acts on the meridian gyro the signal from the tap is acted upon by a high-gain amplifier. This torque generator exerts a torque on the meridian gyro about the azimuth axis, which corresponds to the gyro directional moment, d. H. Something caused by the rotation of the earth, the centrifugal axis of rotation to the north counteracts. The meridian gyro then does not swing with its gyroscopic axis into the Nordrich-5 tion, which would be a lengthy procedure, since the meridian top hung on a ribbon is a practical represents undamped oscillation system with a long oscillation period. Rather, it becomes the meridian top electrically to the housing reference, d. H. the

> <> Tape zero position, tied up. That on the meridian gyro The torque to be exerted is proportional to the gyro straightening torque and therefore at small angles between the gyroscopic axis and north proportional to this Angle. If, given a sufficiently high amplification of the signal supplied by the tap, the The angle between the gyroscopic spin axis and the housing reference is the torque of the The torque generator is proportional to the angle between the housing reference and north. Can one assume that the torque generator works linearly, the amplified signal of the tap, the auC delivers Torque generator is connected, tin measure for this angle between housing reference and north. This signal can be used to display the north direction (DE-AS 20 08 702) or for navigation purposes (DE-AS 25 45 025) can be used.

The electrical fettering of the meridian gyro makes the SchwinEuneso period of the system essential

shortened. It can then be hung up in a freely adjusting tape compared to previously known Meridian gyroscopes the north deviation for a short time, d. H. the angle between the device reference and north to be determined. Nevertheless, it still takes an undesirably long time before a steady-state value is actually achieved has set for the north deviation. The measurement is also affected by external interference.

In order to eliminate the influence of such external disturbances, it is known that on the torque generator connected signal, which serves as a measure for the north deviation, is sent to an analog-digital converter which supplies a digital signal corresponding to this signal. This digital signal is on a computer switched on, the one for recursive averaging from the digital signals sampled at specified time intervals is set up. The averaging suppresses the influence of interference. The fact that the averaging takes place recursively, however, ensures that a measured value is relatively fast is available (DE-OS 25 45 026 and DE-OS 26 18 868 and US-PS 40 75 764). If the reading may initially be flawed, however, it will be improved to the extent that how the averaging takes place. A low-pass filter is usually connected upstream of the analog-digital converter.

The invention is based on the object, in a gyroscope of the type defined at the outset, the time within which a measured value is obtained with a desired accuracy, to further shorten and the To suppress the influence of mechanical disturbances on the measurement.

According to the invention this object is achieved in that

(e) the interference suppression filter is a Kalman filter,

(e,) which is the system of the bound meridian gyro replicates,

(e ₂ ) to which the difference between the signal (Mg) applied to the torque generator and an estimated value (Mg) of this signal supplied by the Kalman filter is applied as the first filter input signal, and

(0 this estimated value (Mg) is output as a measure for the deviation of a device reference from north that quickly becomes a true value and is largely free of interference.

In the case of a Kalman filter, the system that supplies the measured variables is simulated by a model. An estimated value for one of the measured variables resulting from such a model is compared with the value of the measured variable actually measured in the system, and a filter input signal is formed from the difference. These filter input signals are multiplied by suitable time-dependent functions and applied to integration means and change parameters of the model until the filter input signals disappear. The model then corresponds to reality, and estimated values for measured variables of the system, e.g. B. can be obtained as in the present case for the angle Ct ₀ between the device reference and north.

It has been shown that by using such a Kalman filter to determine an estimated value Zt ₀ for the angle between the device reference and north in a gyro device of the present type compared to the known device described, a considerable improvement both in terms of the response time and in terms of the suppression of mechanical disturbances can be achieved.

Refinements of the invention are the subject of the subclaims.
An embodiment of the invention is explained in more detail below with reference to the accompanying drawings:

1 is a schematic perspective illustration of the mechanical structure of the gyroscope;
2 shows, as a block diagram, the combination of the various measured variables of the gyroscope and the Kalman filter for signal processing;

Fig. 3 illustrates the setting process in a known gyroscope and a gyro with a Kalman filter;

4 illustrates the influencing of the setting process by disturbances in a known gyroscope and the gyro with a Kalman filter. The gyro device contains a housing 10 in which a meridian gyro 12 with a mast 14 is suspended by means of a band 16. The housing 10 defines a coordinate system with the vertical axis ζ and the axes uiiJ mutually perpendicular to each other .vundj ·. The axis y represents a device reference. When the meridian gyro 12 with its gyro axis 18 in

The belt 16 is relaxed in the plane defined by the y and z axes. This position is therefore referred to as the belt zero position. The deflection of the meridian gyro 12 with respect to the device reference y is detected by means of a tap 20 indicated here as a potentiometer. The signal from the tap is switched to a torque generator 24 via a high-gain amplifier 22. The gyroscopic spin axis is denoted by 26.
The following designations are used in the following, which can also be seen from Fig. 1:

a = azimuth angle between centrifugal axis 26

and north,

a ₀ = azimuth angle between housing reference y and north,

a _A = deflection of the gyroscopic twist axis 26 with respect to the housing reference,

β = elevation angle of the gyroscopic axis 26,

c _a = torsion spring constant of the belt suspension, m = mass of the centrifugal pendulum formed by the meridian top i2,
r = length of the pendulum,

g = acceleration due to gravity,

I _x = moment of inertia of the centrifugal pendulum

X axis,

/. = Moment of inertia of the centrifugal pendulum by

?-Axis,

H = gyroscopic swirl,

a> _r = angular velocity of the earth's rotation,
ψ = latitude,

Mg = the signal supplied to the torque generator 24 by the amplifier 22,
My = Hω, sin φ, M _n - Hfj> _t cos e>,
V = gain of the amplifier,

= γ a £ = transfer function of the

^{1 +} T \ ^s stronger,

s - variable of the Laplace transform,

K, k (ι, k- 1, 2, 3, 4) = time-dependent functions,

V _Sh - the variance of the measurement noise process of the. Torque generator connected signal,

V _aA = the variance of the measurement noise process of the deviation of the gyroscopic twist axis 26 from the housing reference,

M _a - ■ = disturbance torque about vertical axis Z,

M _ß = disturbance torque around, v-axis

Wy.W. = Power layers of the systere noise inputs.

In the upper part of Fig. 2, the gyroscope, which is generally designated 28, is shown as a block diagram.

The moment equation for the moments about the vertical axis ζ (Fig. 1) reads

I ₁ O = Μ _α -Ηω, cos φ sin α -Hß- [VF _R (s) + C "] a _A.

So La is equal to the sum of the moments acting around the vertical axis ζ, namely the disturbance torques M _n , the gyroscopic directional moment due to the horizontal component of the earth's rotation H <u, cos ρ sin α, the gyroscopic moment due to a rotational speed around the .v axis Hβ and of the torque exerted on the meridian gyro 12 by the torque generator 24 and the belt 16. This latter torque is proportional to the angle a _A by which the centrifugal spin axis 26 is deflected from the housing reference. The proportionality factor contains the gain of the amplifier 22 (in which, for the sake of simplicity, the factor of the torque generator 24 is included). The gain of the amplifier 22 has a time response F _K (j) with a transfer function that is indicated as a factor in equation (1) (mathematically not entirely correct).

The equation of moments about the x-axis results

I _x ß = Mß + H ω, sin φ + Ha - mrg sin β. (2)

/ Jj is again equal to the sum of the moments acting around the x-axis, namely the disturbing moments Mß due to external influences, the gyroscopic moment H ω, sin φ, which is due to the vertical component of the earth's rotation, a gyroscopic moment Ha due to rotational speeds α around the vertical axis ζ as well as with the opposite sign of a pendulum moment P = mrgsinß, which occurs when the meridian gyro 12 with the mast 14 is deflected from the vertical direction and thus when the gyroscopic spin axis 26 is deflected from the horizontal plane. Since it is a heavy top, α and ß, ie the nutation, can be neglected. In the case of fine alignment, that is to say when the gyroscopic spin axis 26 is already oriented essentially to the north and 05 is small, sin α can be replaced by α and sinjS by β . The following linearized model equations then result from equations (1) and (2)

Hβ = -M _N aM _g + W _z

with the compensation torque or the signal applied to the torque generator 24

The torsion spring constant C ″ is negligible, since the gain V is in practice three powers of ten greater than C ₁₁ . The disturbing torques MSS and M _a are indicated in equations (3) and (4) as stochastic signals W, and W..

These model equations (3) and (4) are shown in the block diagram in the upper part of FIG.

ίο A summing point 30 represents equation (4). The deviation α of the centrifugal spin axis 26 from north, which, as will be seen later, appears at point 32 of the block diagram, is multiplied by M _s = H ω, cos φ, as shown by block 34. This product appears with a negative sign at the summing point. Another addition at the summation point is the torque M _r supplied by the torque generator 24, which is proportional to the deviation a _{A of} the gyroscopic twist axis 26 (with the azimuth angle a) from the housing reference (with the azimuth angle ^ ₀ ) and appears at point 36 of the block diagram. This deviation a ₀ , which is obtained from the tap 20, is multiplied by the gain factor of the amplifier 22, as represented by block 37, and also appears with a negative sign at the summing point 30. The third summand which takes effect at the summing point is the quantity W ₁ representing the disturbance torque about the z-axis . According to equation (4), the summing point 30 gives the sum Hβ. the

jo deviation of the gyroscopic spin axis from north in azimuth, ie around the z-axis thus results in an angular velocity ^ around the x- axis (FIG. 1). This angular velocity results from the sum signal at the summing point 30 by dividing by H, which is represented by a block 36. The deflection angle about the x-axis results therefrom by integration, represented by a block 38. The gyroscopic twist axis 26 thus seeks to change its elevation angle β at an angle α in azimuth with respect to north. However, according to equation (3), the elevation angle β causes an angular velocity α about the azimuth axis z through the pendulum moment P = m · τ · g.

A summing point 40 in FIG. 2 represents equation (3).

The elevation angle A which results from the integration symbolized by block 38 (performed by the system) is multiplied by P = mrg. This product becomes effective at the summing point 40 with a positive sign. With a negative sign becomes

so My = Hm, sin φ and the quantity My representing the disturbance torque continue to be effective. At the summing point 40 sr then results according to equation (3) Ha. The angular velocity α about the azimuth axis ζ is obtained by dividing by H, which is represented by block 44. Integrating the angular velocity a, represented by block 44, results in α at point 32. A summation point 48 represents the tap 2Θ, where the difference between the angle O ₀ between the housing reference and north and the angle α between the gyroscopic axis 26 and north is formed and the Angle a _A yields a quantity W ^ (i) = ß ₀ represents stochastic disturbances of βο, which when integrated, as represented by block 5β, result in the angle O ₀ . The initial value of the integration is given as O ₀ (Ό).

This block diagram thus represents the gyro device 28 shown in FIG.

A signal evaluation circuit contains a Kalman filter 52, which is shown in the lower part of FIG. 2 is shown.

This Kalman filter 52 simulates the model of the gyro device 28 illustrated by the block diagram. It supplies estimated values for the various variables, which are identified by a roof ("). Mg is, for example, an estimated value for the torque exerted by the torque generator 24 on the meridian gyro or the signal applied to the torque generator Signal Mg and the estimated value Λ / g of this signal supplied by the Kalman filter 52.

Optionally, the difference between a signal representing the deviation a _{A of} the meridian gyro 12 from the housing reference y and an estimated value a _{A of} this signal supplied by the Kalman filter 52 can be added to the Kalman filter 52 as a second filter input signal. This is indicated by dashed lines in FIG. 2.

The FiliCTcingärigsiigriäic are time-dependent with Factors multiplied and integrated, whereby the parameters of the model are changed by the integrals, until the filter input signals disappear. It can then be assumed that the modified in this way Model corresponds to the real system, so that the estimated values tapped from the model correspond to those in the Real values occurring in the system.

In the preferred exemplary embodiment, the Kalman filter 52 has the following structure:

In a first summing point 54, the difference is formed between a first signal, which represents an estimated value Mg for the signal switched to the torque generator 24, and a second signal, which multiplied by H ω, cos φ, the estimated value a of the angle between the gyroscopic axis 26 and north represents, where, as said, H is the circular twist, ω, the angular velocity of the earth's rotation and φ the geographical latitude. The difference obtained is divided by the gyroscopic swirl H , as indicated by block 56. At a second summing point 58, the sum is formed of the difference, divided by the gyroscopic twist, from the first summing point 54 and the _{first filter input signal multiplied by a time-dependent factor Af 22} , the multiplication being represented by block 60. And the sum formed in the second summing point 58 is integrated by integration means 62. The signal obtained in this way, which represents an estimated value β for the elevation angle of the gyroscopic swirl axis 26, is multiplied by a factor P = mrg, as shown by block 64, where m is the mass of the meridian gyro 12, r the length of the gyro pendulum (Fig. 1) and g is the acceleration due to gravity. In a third summing point 66, the sum is formed from the integral multiplied by / ″ from the integration means 62 and a signal M _v = Hm, sin φ.

The sum formed in the third summing point 66 is divided by the gyroscopic twist H , as indicated by block 68. In a fourth summing point 70, the sum is formed from the sum of the third summing point 66 divided by the gyroscopic twist H and the first filter input signal multiplied by a time-dependent factor K _n , the factor AT _{12 being represented} by block 72. The sum formed in the fourth summing point 70 is integrated by integration means 74, the signal thus obtained representing the said estimated value a of the angle between the gyroscopic axis and north, which, multiplied by the factor M _K = H o _e cos φ in represented by block 76 the first summing point 54 is subtracted. The first filter input signal is multiplied by a time-dependent factor AT ₃₂ , represented by block 78, and then integrated by integration means 80, a signal being obtained which represents the estimated value ₀ for the angle between device reference> »and north. In a fifth summing point 82 the difference is formed from the integrated sum of the fourth summing point 70 and the _{first filter input signal multiplied by the factor AT 32} and integrated, a signal being obtained,

ίο that represents an estimated value α _λ for the deflection of the meridian gyro 12 against the housing reference.y. At a sixth summing point 84, the sum is

VT ₀
formed from that multiplied by a factor ~ zr

Signal that is generated at point 86 by dividing the sum of the third summing point 66 by the gyroscopic swirl H.

which was multiplied by a factor of ^

t \

Difference from the fifth summing point 82, the _{filter input signal multiplied by a time-dependent factor λ '42} and, with a negative sign,

the estimated value Mg, multiplied by a factor, of the signal switched to the torque generator 24. Here is the factor - ^ through block 88, the

'ι

Factor - through block 90, the factor AT ₄₂ through block 92

^Ά 1

and the factor γ is symbolized by block 94. The sum formed in the sixth summing point is integrated by integration means 96, as a result of which said estimated value Mg of the signal connected to the torque generator 24 is obtained.

Optionally, in the second summing point 58, this can also be done with a time-dependent factor AT _2! , Multiplied second filter input signal are added represented by the dashed block 98, which, as said, the difference of the deviation of the meridian gyro 12 of the housing ^"f erence, y representative signal and one of the Kalman filter 52 estimated value of a _A supplied this Signal is. In the fourth summing point 70, the second filter input signal multiplied by a time-dependent factor K _n , represented by the dashed block 100, would then be added. The integration means 80, which _{supply an estimated value S 0 of} the angle between the device reference.) 'And North, would also add the second multiplied _{by a time-dependent factor AT 31}

so integrated filter input signal. The factor AT ₃ is symbolized by block 102. Finally, in the sixth summing point 84, the _{second filter input signal multiplied by a time-dependent factor AT 41} , represented by block 104, would also be added.

To form the first filter input signal, in an eighth summing point 106 the sum of the signal Mg actually applied to the torque generator 24, with a negative sign the estimated value Mg delivered by the Kalman filter 52 of this signal applied to the torque generator 24 and a signal V _Up which represents the variance of the measurement noise process of the signal Mg applied to the torque generator 24 To form the second filter input signal, the sum is formed in a seventh summing point 108 of the signal a supplied by the tap 20 and representing the deviation of the meridian gyro 12 from the housing reference y _A , with the negative sign that of that

H

Kalma-ii filter 52 supplied estimated value a _{A of} this signal representing the deviation of the meridian gyro M from the housing reference y and a signal V _aA representing the variance of the measurement noise process of the deviation of the meridian gyro from the housing reference.

As can be seen, the Kalman filter 52 simulates the linearized system of the gyroscope 28. The blocks 88, 90, 94 with the integrator 96 are a replica of the amplifier 22, its transfer function with

(6)

1 + T \ s

assumed v / ird. This model is given by the filter input signals from the summing points 106 and 108 with time-dependent factors, represented by the blocks 60, 98, 72, 100, 102, 78, 92 and 104, which are applied to the inputs of integration means 62, 74, 80 and 96 will »., varied until the filter input signals disappear and the model is adapted to reality.

The F i g. 3 and 4 illustrate the signal processing means resulting from the design according to the invention advantages achieved over the prior art.

In Fig. 3, the line 110 represents the real value of the angle ar ₀ between the device reference and north. Curve 112 shows how the display of a device, for example according to DE-OS 19 41 808, runs into this value a ₀ when it affects the torque generator 24 switched signal Mg is only passed through a low-pass filter for signal processing. Curve 114 shows the arrival of the measured value if, in addition to the low-pass filter, a mean value filter according to the type of US Pat. No. 4,075,764 is provided. Finally, curve 116 shows the progression of the display into the real value when using the described Kalman filter 52. It can be seen that the signal processing described is approximately three times as fast as the signal processing according to the prior art. The signal processing described allows the angle α ₀ to be estimated to an accuracy of 1 ~ after approximately 20 seconds, while the known arrangement only yields an accuracy of approximately 3 "after 60 seconds.

4 shows the behavior with regard to the suppression external disturbances again in comparison to the previously known solutions.

Line 118 shows the real value of the angle ao. Curve 120 shows the course of the estimated value a ₀ when interference occurs when the signal Mg is only passed through a low-pass filter. Curve 122 shows the course of the estimated value for the same interference using a low pass with an average filter according to US Pat. No. 4,075,764. Curve 124 finally shows the course over time of the estimated value when a Kalman filter 52 of the type described is used.

For this purpose 4 sheets of drawings

65

Claims (1)

Patent claims: 1. Containing gyro to determine north direction (a) a meridian top (12) suspended in a housing (10) in a pendulous manner, (b) a tap (20) which responds to the deflection (a _A ) of the meridian gyro with respect to a housing reference (y), (c) a torque generator (24), the (C ₁ ) acts around the vertical axis (z) on the meridian gyro (12) and (C ₂ ) is acted upon by the signal from the tap (20) in the sense of tying the meridian gyro (12) to the housing reference (y) , and (d) a signal evaluation circuit that (d,) is acted upon by the signal (Mg) applied to the torque generator, (d ₂ ) contains a filter for suppressing interference and (d ₃ ) supplies a filtered signal which represents the deviation (σ ₀ ) of the housing reference (y) from north,
characterized in that (e) the Plier for interference suppression is a Kalman filter (52), M (e,) which the system of the fettered meri- diankreiseh, (M) simulates,
(e ₂ ) to which as e. jth filter input signal is the difference between the signal (Mg) applied to the torque generator and an estimated value (Mg) of this signal supplied by the Kalman filter (52), and
(0 this estimated value (Mg) is output as a measure for the deviation of a device reference from north that quickly becomes a true value and is largely free of interference. 3. Gyro device according to claim 1, characterized in that on the Kalman filter, in addition, as a second filter input signal, the difference of a signal (a _A ) representing the deviation of the meridian gyro (12) from the housing reference un <i one of the Kalman filter (52 ) delivered estimated value (a _A ) of this signal is applied. 3. Gyroscope according to claim 1, characterized in that the Kalman filter (52) has the following structure owns: (a) The difference is formed at a first summing point (54) (a,) a first signal which represents an estimated value Mg for the signal switched to the torque generator (24), and fee (A ₂ ) a second signal which represents the estimated value a, multiplied by Ηω, cos φ , of the angle between the gyroscopic axis (26) and north, where
H the gyro twist b5 ω, the angular velocity of the earth's rotation and
Φ is the latitude. (b) The difference obtained is divided by the gyroscopic twist H. (c) The sum is formed at a second summing point (58) (cj) the difference from the first summing point (54) and divided by the gyroscopic swirl H (C ₂ ) of the first filter input signal multiplied by a time-dependent factor K _n. (d) The sum formed in the second summing point (58) is obtained by integration means (62) integrated, (e) the signal obtained in this way, which represents an estimated value jj for the elevation angle of the gyroscopic twist axis, is multiplied by a factor P = m · τ-g , where m is the mass of the meridian top,
r is the length of the pendulum and
g is the acceleration due to gravity.
(0 In a third summing point (66) the sum is formed from
(fj) with the multiplied integral of P the integration means (62) and
(f ₂ ) a signal M, = Ha, sin φ.
(g) The sum formed in the third summing point (66) is divided by the gyroscopic twist H. (h) In a fourth summing point (70) the sum is formed from (hi) the sum of the third summing point (66) and divided by the gyroscopic twist H (h ₂ ) the first filter input signal multiplied by a time-dependent factor K _n. (i) The sum formed in the fourth summation point (70) witu integrated by integration means (74), the signal thus obtained representing said estimated value a of the angle between the gyroscopic axis (26) and north,
(j) The first filter input becomes (j,) with a time-dependent factor K ₃₂ multiplied and then U ₂ ) integrated by integration means (80), whereby a signal is obtained which represents the estimated value a ₀ for the angle between the device reference (y) and north,
(k) In a fifth summing point (82) the difference is formed from
(k i) the integrated sum of the fourth Summing point (70) and
(k ₂ ) the first filter input signal multiplied by the factor K _n and integrated, whereby a signal is obtained which represents an estimated value a _A for the deflection of the meridian gyro (12) against the housing reference (y) ,
(I) In a sixth summing point (84) the sum is formed from (1 ₁ ) the signal multiplied by a factor \ ~~ f ~) that was obtained by dividing the sum of the third summing point (66) by the gyroscopic swirl //, (1 ₂ ) that multiplied by a factor -! Difference from the fifth summing point (82), (1 ₃ ) the filter input signal multiplied by a time-dependent factor K _{42 and,} (1 ₄ ) with a negative sign, the one with represents the estimation reference 00 multiplied by a factor hpi.