JP3254538B2 - Gyro compass - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gyro compass suitable for use in measuring the course of a navigating body such as a ship.

[0002]

2. Description of the Related Art Conventionally, a gyrocompass is often used for measuring a course of a ship. FIG. 4 shows an example of a conventional gyrocompass. The gyro compass has a mechanism section A as shown in FIG. 4 and a control section as shown in FIG. First, the mechanism section A will be described with reference to FIG.

The mechanism section A of the gyro compass has a gyro case 1 having a built-in gyro rotor, and the gyro rotor is rotated at a high speed by an induction motor or the like at a constant rotational speed. The gyro rotor or gyro has a horizontal spin axis, and its rotation vector is southward (clockwise as viewed from the north side).

The gyro case 1 has a pair of vertical axes 2 and 2 ′ projecting up and down, and the vertical axes 2 and 2 ′ correspond to a vertical ring 3 disposed outside the gyro case 1. The ball bearings 4 and 4 'attached to the respective positions are fitted to the inner races. The upper vertical axis 2 is the suspension line 5
Is attached to the suspension line mounting base 5 'through the
Such suspension line mounting stand 5 ′ is supported on a vertical ring 3.

[0005] The total weight of the gyro case 1 is borne by the hanging wire 5 or the hanging wire mount 5 '.
Ball bearings 4, in which the vertical shafts 2 and 2 'are fitted,
No thrust load is applied to 4 ′, and the friction torque of the ball bearings 4, 4 ′ can be reduced.

[0006] A pair of liquid ballasts 6, 6 'are mounted on both the east and west sides of the vertical ring 3, and the liquid ballasts 6, 6' are mounted.
Functions as a finger northing device for moving the gyro case 1 northward as described in detail below.

The vertical ring 3 has a pair of horizontal axes 9, 9 ',
The horizontal axes 9, 9 'are perpendicular to both the vertical axes 2, 2' and the spin axis of the gyro and project outward from the east-west position, and the ends of the horizontal axes 9, 9 'are vertical rings. 3 are respectively fitted to inner rings of ball bearings 11 and 11 ′ attached to corresponding positions of a horizontal ring 10 arranged outside.

The horizontal ring 10 further has a pair of gimbal axes 12, 12 'orthogonal to the horizontal axes 9, 9' in a horizontal plane. Each of such gimbal shafts 12, 12 ′ is attached to a tracking ring 13 disposed outside the horizontal ring 10.
The pair of gimbal shaft ball bearings 14 and 14 ′ are fitted to the inner races.

The follower ring 13 has a pair of follower shafts 15 and 15 'projecting up and down.
Reference numeral 5 'is fitted to the inner ring of the following shaft ball bearings 17, 17' attached to the corresponding position of the panel device 16.

[0010] A compass card 18 is attached to the shaft end of the upper follow-up shaft 15.
The azimuth angle of the bow is read by the reference numeral 8 and the base line 18B fixed to the position corresponding to the bow side of the panel device 16. An azimuth gear 21 is attached to the lower tracking shaft 15 ',
The azimuth gear 21 is connected to the board 1 via the azimuth pinion 20.
6 is connected to a rotation axis 19A of an azimuth servomotor 19 attached to the lower part of the motor 6. The rotation shaft 22A of the direction transmitter 22 is engaged with the direction gear 21 via a gear train, and the direction signal of the direction transmitter 22 is converted into an electric signal and transmitted to the outside.

The inside of the horizontal ring 10, that is, the portion including the horizontal ring 10, the vertical ring 3, the gyro case 1, and the like is usually called a sharp feeling part. Such sharp parts are provided on the gimbal axes 12, 12 '.
Below, a heavy physical pendulum is configured so that the horizontal axes 9, 9 'are always kept in a horizontal plane regardless of the inclination of the hull.

A tracking pickup 8 is mounted on the east side of the gyro case 1. The tracking pickup 8 is composed of a primary coil 8-1 of a differential transformer arranged in the gyro case 1 and a vertical ring opposed thereto. And the secondary coil 8-2 of the differential transformer arranged at the position No. 3.

If there is a difference between the azimuth of the gyro case 1 and the azimuth of the vertical ring 3, such a difference is detected by a tracking pickup 8 provided on both, and the azimuth difference is converted into an electric signal 8A. And supplied to an external servo amplifier 23. The electric signal 8A is amplified by the servo amplifier 23 and supplied to the azimuth servomotor 19, whereby the azimuth servomotor 19 is controlled.

The rotation of the azimuth servomotor 19 is based on the rotation axis 1
9A, the gear train, and the azimuth gear 21, the power is transmitted to the follower ring 13, and further transmitted to the vertical ring 3 via the horizontal ring 10, the horizontal shafts 9, 9 ′, and so on.
Is always kept at zero. Thus, an azimuth servo system for controlling the azimuth servomotor 19 is configured.

By the operation of the azimuth servo system, the horizontal axis 9,
9 ′ and the spin axis of the gyro always maintain an orthogonal relationship, and the torsional torque of the suspension wire 5 is not applied to the gyro case 1. That is, the gyro case 1 is completely shut off from angular motions such as rocking of the hull by the action of the three axes of the vertical axes 2, 2 ', the horizontal axes 9, 9' and the gimbal axes 12, 12 'having the servo system. Thus, a gyroscope is formed.

The above-described liquid ballast 6 provides the gyroscope with a fingering force to provide a function as a compass.
It is.

The liquid ballast 6 is a kind of communication pipe, and is composed of two pots arranged on the north and south sides of the gyro case 1 and a liquid pipe connecting the two pots on the upper side with the air pipe communicating on the lower side. And The inside of the liquid ballast 6 is filled with a liquid having a high specific gravity, and the liquid level is arranged in two pots.

It is assumed that the spin axis of the gyro is inclined by an angle θ with respect to a horizontal plane, and the north end of the finger is disposed above the horizontal plane. Liquid ballast 6 is configured to provide a ubiquitous torque Q _C in proportion to the inclination angle θ of the spin axis with respect to the horizontal plane to the gyro horizontal axis 9, 9 'around. Such ubiquitous torque Q _C is represented by the formula for a number 1.

[0019]

(Equation 1)

Where K is the ballast constant or the northern constant, τ
_B is a time constant when the liquid ballast 6 is approximated to a first-order lag system, and S is a Laplace operator.

In this way, a torque proportional to the inclination angle θ of the spin axis of the gyro with respect to the horizontal plane is generated in the liquid ballast 6, and this torque acts to rotate the gyro case 1 around the horizontal axis 9, 9 '. , Gyro case 1 has a northern force, thus forming a gyro compass. The loop that includes such a liquid ballast 6 is called a northern loop or an azimuth loop.

In this embodiment, a vibration damping loop is provided for damping the finger north movement of the gyro case 1 provided by the liquid stabilizer 6. Such a vibration suppression loop includes an inclinometer 30 and a torquer 32 mounted on the gyro case 1, an azimuth transmitter 22, and a gyro compass control unit B described below.

FIG. 5 shows a configuration of a vibration control loop and a control unit B of a conventional gyrocompass. The control unit B includes an error correction unit 10
It has 0 and a coefficient unit 31. The inclinometer 30 detects the inclination angle of the spin axis with respect to the horizontal plane, and outputs the detection signal SA indicating the inclination angle. The detection signal SA is supplied to the coefficient unit 31 and multiplied by the coefficient μ ′. The vibration suppression signal DS thus obtained is corrected by the correction signal A1 supplied from the error correction unit 100, and a Toruca signal TS is generated. The correction signal A1 corrects an equivalent bias error caused by the inclination angle of the spin axis with respect to the horizontal plane.

The Toruca signal TS is supplied to the Toruca 32. Torquer 32 in response to torquer signal TS, it generates a torque Q _D for rotating the gyro case 1 and the vertical ring 3 about a vertical axis 2,2 '. Torque Q _D produced by such torquer 32 is as the formula for a number of 2.

[0025]

## EQU2 ## Q _D (S) = μθ (S) μ = K _ACC · μ ′ · K _T SA = K _ACC · θ (S)

Here, μ is a damping constant, K _ACC is a gain of the inclinometer 30, μ ′ is a proportional constant of the coefficient unit 31, and _KT is a gain of the torquer 32.

In this way, the finger movement of the gyro case 1 imparted by the liquid ballast 6 is attenuated. Therefore, such a loop is called a damping loop or a damping loop.

The error correction unit 100 supplies the data from the inclinometer 30.
Indicating the tilt angle of the spin axis with respect to the horizontal plane
Outgoing signal SA and spin axis supplied from bearing transmitter 22
Azimuth signal Az indicating the azimuth angle of the
None) Speed signal indicating the speed of the vehicle supplied from
V ′ and a latitude setting value λ indicating the latitude of the navigation body₀’
To calculate and output the correction signal A1 and the true azimuth signal Azt.
Power. Latitude setting value λ ₀’Is set manually, for example
It is.

The true azimuth signal Azt is a value obtained by removing the estimated value φe of the azimuth error φ generated by the movement of the navigation vehicle from the azimuth of the spin axis detected by the azimuth transmitter 22.

Referring to FIG. 6, the configuration of error correcting section 100 is shown. The error correction unit 100 includes an error calculation unit 100A, a bias error correction unit 100B, and an azimuth error correction unit 100C. The error calculation unit 100A includes a model calculation unit 100A1, an error detection unit 100A2, and an external information processing unit 100A3.

Referring to FIGS. 7 to 11, error correction unit 100
The configuration and function of each section will be described. In such a diagram, g
Is the gravitational acceleration, R is the earth radius, Ω is the Earth's rotation angular velocity, H
Is the angular momentum of the gyro, and λ 'is the latitude of the vehicle.

V ′ is a velocity component, ω ′ is an angular velocity component, σ ′
Represents an acceleration component. The suffix N indicates the north-south axis direction of the earth coordinate system, and the north direction is positive. The subscript E represents the east-west axis direction of the earth coordinate system, and the east direction is positive.

Φe represents an estimated azimuth angle error with respect to true north of the spin axis, θe represents an estimated inclination angle of the spin axis with respect to a horizontal plane, Δe represents an estimated liquid surface inclination angle of the liquid ballast 6, and be represents an estimated equivalent bias value.

FIG. 7 shows a configuration example of the model calculation unit 100A1. The model calculation unit 100A1 has a mathematical model configuration equivalent to the gyro compass configuration. That is, the estimated inclination angle signal θe and the north-south acceleration component σ _N ′ generated by the movement of the navigation body are added to generate the estimated detection signal SB. The estimated detection signal SB is supplied to the coefficient unit 50 to generate the estimated liquid level inclination angle signal ξe. The coefficient unit 50 corresponds to the first-order lag element of the liquid ballast 6. The estimated liquid level inclination angle signal ξe is supplied to a coefficient unit 51, where the ballast constant K
Is multiplied by a value K / H, which is obtained by dividing the angular momentum H of the gyro,
The precession angular velocity Δe × K / H around the vertical axis is obtained.

The precession angular velocity Δe × K / H
The vertical component Ω _S ′ of the equivalent earth rotation angular velocity is added via the coordinate converter 40. Such an added value is supplied to the integrator 52 to generate an estimated azimuth angle error value φe. This corresponds to the fact that the vertical components of the precession angular velocity and the earth rotation angular velocity act on the vertical axis of the gyro case 1 to cause azimuth movement, thereby causing an azimuth error.

The estimated azimuth angle error φe is supplied to a coefficient unit 53 and is multiplied by the horizontal component Ω _C ′ of the equivalent earth rotation angular velocity. The output signal from the coefficient unit 53 is added to the north-south angular velocity component ω _N ′ obtained by dividing the north-south velocity component V _N ′ of the navigation body by the earth radius R, and is supplied to the integrator 54.
Thus, the integrator 54 outputs the estimated inclination angle θe. This corresponds to the fact that the product of the azimuth error and the horizontal component of the earth rotation angular velocity is input as an angular velocity to a gyro element around the horizontal axis of the gyro.

The above corresponds to the north loop or the azimuth loop of the gyro compass. This loop consists of two integrators 5
Since it has 2, 54 and two poles, the response of the system is oscillatory.

Similarly, the estimated detection signal SB is supplied to a coefficient unit 55, and is multiplied by a value μ / H obtained by dividing the damping constant μ by the angular momentum H of the gyro, thereby obtaining a precession angular velocity SB × μ / H around the horizontal axis. Is obtained.

The precession angular velocity SB × μ / H
Is supplied to the output side of the coefficient unit 53 via the coordinate converter 40. Such a loop acts to reduce the estimated inclination angle θe which is the output signal of the integrator 54, and thus corresponds to attenuating the finger north movement. That is, such a loop corresponds to a damping loop or a vibration suppression loop.

Here, the function of the coordinate converter 40 will be described. When the navigation body moves, an acceleration component σ _E ′ in the east-west direction is generated, and the gyro case 1 tilts in the east-west direction. The coordinate converter 40 is provided for removing a modeling error generated by rotating the coordinate axis due to the east-west acceleration component σ _E ′.
The coordinate converter 40 has four coefficient units 40-1, 40-2, 4
Each coefficient unit multiplies the input signal by the sine value or cosine value of the east-west direction acceleration component σ _E ′.

The integrator 56 outputs an estimated equivalent bias value signal be. The estimated equivalent bias value signal be is an estimated value of the equivalent bias value signal b of the gyro compass,
Such an equivalent bias value signal b includes a mechanical unbalance torque amount around the horizontal axis, an error in the mounting angle of the inclinometer 30 with respect to a horizontal plane passing through the spin axis, a drift amount that changes according to the temperature of the inclinometer 30, and the like.

FIG. 8 shows a configuration example of the error detection section 100A2. Error detecting unit 100A2 comparators and the coefficient unit 109 having a coefficient of inverse 1 / K _ACC of inclinometer 30 of the gain K _ACC 1
01 and three coefficient units 102, 103 and 104. The three coefficient units 102, 103, and 104 have coefficients Kθ, Kφ, and Kb, respectively.

The coefficient unit 109 receives the detection signal SA for indicating the inclination angle of the spin axis with respect to the horizontal plane supplied from the inclinometer 30, and the coefficient 1 / K _ACC to match the unit system.
Multiply by The comparator 101 receives the estimated detection signal SB supplied from the model calculation unit 100A1 and compares it with the output signal of the coefficient unit 109. Thus, the comparator 101
Outputs an error signal ERR.

Based on the value of the error signal ERR, it can be determined whether or not the actual state of the gyro compass matches the state estimated by the model calculation unit 100A1. Such an error signal ERR is output to three coefficient units 102,
103 and 104, and the correction amounts εθ and ε, respectively.
φ and εb are generated.

Here, the first correction amount εθ is calculated by the model calculation unit 1
00A1 is a correction amount for correcting the estimated inclination angle signal θe calculated by the integrator 54, and a second correction amount ε
φ is a correction amount for correcting the estimated azimuth angle error signal φe calculated by the integrator 52 of the model calculation unit 100A1, and a third correction amount εb is a correction amount calculated by the integrator 56 of the model calculation unit 100A1. This is a correction amount for correcting the equivalent bias value signal be.

In the error detecting section 100A2, the mechanism section A
Is controlled so that the detection signal SA output from the inclinometer 30 corresponds to the estimated detection signal SB output from the model calculation unit 100A1, and thus has a function corresponding to a negative feedback loop. Three coefficient units 102, 103, 104
Are obtained as appropriate values by Kalman filter theory in control engineering (or observer theory, least squares method in statistics, etc.).

FIG. 9 shows a configuration example of the external information processing section 100A3. The external information processing unit 100A3 includes an azimuth signal Az supplied from the azimuth transmitter 22 for indicating the azimuth of the spin axis, and a speed signal V 'supplied from a log speedometer (not shown) for indicating the speed of the navigation vehicle. North and south speed calculator 60 and east-west speed calculator 70, and differentiators 61 and 71
And coefficient units 63 and 73 having a coefficient of a reciprocal of the earth radius R
And a coefficient unit 6 having a coefficient of the reciprocal 1 / g of the gravitational acceleration g
2, a coefficient unit 72 having a reciprocal 1 / g of the gravitational acceleration g and a coefficient −1 / g having an opposite polarity, and an integrator 64.
And the coefficients sinλ ′, tanλ ′, and cosλ ′, respectively.
, And adders.

As shown in FIG.
North-South velocity component V_N′ Is calculated and the north-south velocity component
V_NNorth-south acceleration component σ_N’, North-south angular velocity component
ω_N'And the latitude component λ' are sequentially obtained. East-west speed performance
The east-west velocity component V _E’Is calculated,
East-west velocity component V_EEast-west acceleration component σ_E’And east
West angular velocity component ω_E'Are sequentially obtained.

Earth's rotation angular velocity Ω, east-west angular velocity component ω _E '
And the horizontal component Ω of the equivalent earth rotation angular velocity from the latitude component λ '
_c ′ and the vertical component Ω _s ′ are calculated.

The equation calculated by the external information processing unit 100A3 is shown by the following equation (3).

[0051]

[Number 3] _{V N '= V'cosAz V E'} = V'sinAz σ N '= (dV N' / dt) / g σ E '= (dV E' / dt) / g ω N '= V N _{'/ R ω E' = V} E '/ R λ' = λ 0 + ∫ω N 'dτ Ω s' = Ωsinλ '+ ω E' tanλ 'Ω c' = Ωcosλ '+ ω E'

The first equation of the equation (3) is a north-south speed calculation unit 6
0, the second formula is calculated by the east-west speed calculator 70, the third formula is calculated by the differentiator 61 and the coefficient unit 62, and the fourth formula is calculated by the differentiator 71 and the coefficient unit 72. And
The fifth expression is calculated by the coefficient unit 63, and the sixth expression is calculated by the coefficient unit 73.
Is calculated by the integrator 64, and the seventh equation is calculated by the integrator 64.
The expression is calculated by the coefficient units 80 and 81 and the adder, and the ninth expression is calculated by the coefficient unit 82 and the adder.

FIG. 10 shows a configuration example of the bias error correction section 100B. The bias error correction unit 100B is configured to include coefficient units 107 and 108 having correction gains K _FB1 and K _FB2 , respectively. The modified gains K _FB1 and K _FB2 are represented by the following equation (4).

[0054]

## EQU4 ## K _FB1 = − (μ / K) · (1 / K _T ) K _FB2 = −μ / K

Here, μ is a damping constant, K is a ballast constant, and K _T is a proportional constant of the torquer 32.

In the bias error correction section 100B, the estimated equivalent bias value signal be supplied from the error calculation section 100A is input to coefficient units 107 and 108, respectively, thereby generating correction signals A1 and A2. The first correction signal A1 corrects the Toruca signal TS input to the Toruca 32 as shown in FIG. Thereby, the azimuth angle error φ caused by the equivalent bias value b of the gyro compass is removed. The second correction signal A2 corrects the output signal of the coefficient unit 55, that is, the precession angular velocity SB · μ / H, as shown in FIG. Thereby, the estimated azimuth angle error φe caused by the estimated equivalent bias value be is removed by the model calculation unit 100A1.

FIG. 11 shows a configuration example of the azimuth error correction unit 100C. The azimuth error correction unit 100C includes an azimuth signal A indicating the azimuth of the spin axis supplied from the azimuth transmitter 22.
The true azimuth angle signal Azt is generated by subtracting the estimated azimuth angle error signal φe from z. The estimated azimuth error signal φe will be described later. Thus, the azimuth error correction unit 100
A true azimuth signal indicating the true azimuth from which the azimuth error φ has been removed by C is obtained.

As described above, the error correction unit 100 applies the model calculation unit 100 to the detection signal SA supplied from the inclinometer 30.
The configuration is such that the estimated detection signal SB generated in A1 always follows. Therefore, the azimuth angle error φ of the unknown gyro compass which cannot be directly measured by the error correction unit 100 from the estimated azimuth angle error signal φe and the estimated equivalent bias value signal be generated by the model calculation unit 100A1. And an equivalent bias value signal b are obtained.

[0059]

If the navigating body equipped with the gyro compass makes a relatively gentle movement even if it makes a turn, a change of course, or the like, the true azimuth signal Azt output from the control unit B is provided. (Or the repeater signal) is substantially true, and there is no particular problem. An azimuth error φ occurs when the gyrocompass is accelerated by the movement of the navigation body.
00 external information processing unit 100A3 of the error calculation unit 100A
If the values of the velocity signal V ′, the azimuth signal Az, and the latitude setting value λ ′ input to the model calculation unit 100A are correct values,
This is because the estimated azimuth angle error φe generated at 1 is obtained as a value equal to the actual azimuth angle error φ.

However, in the case of a high-speed ship in which the navigation speed of the navigating body may exceed 20 knots, generally, when the navigating body makes a motion such as turning or changing the course, the bow direction speed V ′ is obtained.
In addition, a speed perpendicular to the bow direction, that is, a so-called skid speed occurs.

Referring to FIG. 12, the turning characteristics of a navigator, particularly a ship, will be described. First, reference numerals in FIG. 12 will be described.

[0062] OX _L Y _L is a global coordinate system, OX _L
Axis OY _L axis points to the north direction (N) is arranged to point to the east (E). The suffix L is attached to the speed, acceleration, and the like in the earth coordinate system.

[0063] OX _B Y _B is a navigation body coordinate system such as a ship, OX _B axis points to bow direction, OY _B shaft is disposed to point to the right direction to the bow. The suffix B is attached to the speed, acceleration, and the like in such a navigation body coordinate system.

OX_PY_PIs the trajectory coordinates of the navigating body such as a ship
OX_PThe axis is in the tangent direction of the trajectory of the vehicle
OY_PThe axis is curving in the normal direction of the trajectory
Heart O _PIt is arranged to point in the direction. Therefore, the trajectory
Center of curvature O_PIs always OY_POn the axis. Such a locus
The subscript P is attached to the speed, acceleration, and the like in the coordinate system.

As shown in the drawing, when the azimuth angle of the bow, that is, the azimuth angle signal is Az, and the trajectory angle or trajectory azimuth angle at that time is Az ', the side slip angle δ is δ = Az-Az'.

It is assumed that the direction of the true turning speed of the navigation body coincides with the OX _P axis and the direction of the centrifugal force (or centripetal force) coincides with the OY _P axis. It is also assumed that the tidal velocity is zero, and the actual bow speed V ′ is equal to the bow speed V _XB in the navigation body coordinate system.

The north-south axis velocity V _XL and the east-west axis velocity V _YL in the earth coordinate system acting on the gyro case 1 of the gyro compass are expressed by the following equation (5).

[0068]

(Equation 5)

In equation (5), it is assumed that the magnitude of the sideslip angle δ is sufficiently small.

The north-south velocity V _XL in the earth coordinate system
And the east-west axial speed V _YL are compared with the north-south speed component V _N ′ and the east-west speed component V _E ′ calculated by the external information processing unit 100A3 of the error calculation unit 100A. By rewriting the first expression and the second expression of the expression (3), the following expression (6) is obtained.

[0071]

(Equation 6)

The difference between the second equation of the equation (6) and the equation of the equation (5) is obtained.

[0073]

(Equation 7)

Thus, the north-south speed component V _N 'and the east-west speed component V _E ' calculated by the external information processing section 100A3.
Is the north-south velocity error component Δ
V _N ′ and the east-west speed error component ΔV _E ′ are included. Number 7
As is clear from the equation, the error components ΔV _N ′, Δ
V _E ′ is due to the sideslip speed δ.

[0075] In general, the magnitude of the slip angle δ is proportional to the path velocity V _P and the turning angular velocity dAz '/ dt. Therefore, in the conventional gyrocompass, when the speed of the navigating body is increased, the values of the north-south speed error component ΔV _N ′ and the east-west speed error component ΔV _E ′ expressed by the equation (7) become large and may be ignored. become unable.

Conventionally, the estimated equivalent bias value signal be and the estimated azimuth angle error signal φe calculated by the error correction section 100 have errors due to the north-south speed error component ΔV _N ′ and the east-west speed error component ΔV _E ′. And there is a disadvantage that an accurate value cannot be obtained as the true azimuth signal Azt.

Since the north-south speed error component ΔV _N ′ and the east-west speed error component ΔV _E ′ are present even when the vehicle is traveling at medium to low speeds, the true azimuth signal A with high accuracy is obtained.
When zt is required, there is a disadvantage that conventional gyrocompasses cannot cope.

In view of the above, the present invention provides a gyro compass that can always obtain an accurate true azimuth angle signal Azt (or a repeater signal) even when a navigation body such as a ship makes a turn or a change of course. The purpose is to provide.

[0079]

According to the present invention, for example, as shown in FIG. 1, a gyro case incorporating a gyro having a substantially horizontal spin axis and a gyro case are provided with three degrees of freedom. A supporting device for supporting, and a detection signal S for detecting an inclination angle of the spin axis with respect to a horizontal plane and indicating the inclination angle;
An inclinometer 30 that outputs A, a fingering device that applies a torque proportional to the tilt angle of the spin axis with respect to the horizontal plane to the gyro case about a horizontal axis orthogonal to the spin axis, and a toka signal TS that is input. Mechanism A having a torquer 32 for applying a torque around the vertical axis of the gyro case, and an azimuth transmitter 22 for detecting the azimuth of the spin axis with respect to the heading of the navigating body and outputting an azimuth signal Az indicating the same. An antenna 90-1 installed on a navigation body to receive radio waves from GPS satellites;
1, a preamplifier 90-2 for amplifying and outputting the radio wave received by the antenna 1, a GPS latitude signal for inputting an output signal from the preamplifier 90-2 to indicate the latitude of the antenna installation position, and a speed of the antenna installation position. GPS speed signal to instruct and GPS to instruct azimuth of antenna installation position
A reception processing unit 90-that outputs a GPS signal including a direction signal;
3, a detection signal SA output from the inclinometer 30, an azimuth signal Az output from the azimuth transmitter 22, and a GP output from the GPS unit.
And a control unit B ′ that receives the S signal GS, outputs a Toruca signal TS to the Toruca, and generates a true azimuth signal Azt indicating the true heading of the bow of the navigation body.

According to the present invention, in the gyro compass, for example, as shown in FIG.
Correction unit 10 which inputs the azimuth signal Az and the GPS signal GS and outputs the true azimuth signal Azt and the correction signal A1.
It is configured to generate a Toruca signal TS by generating a damping signal DS by multiplying the detection signal SA by a constant μ ′ and correcting the damping signal DS by the correction signal A1.

According to the present invention, in the gyro compass, the error correcting unit 100 ′ includes the equivalent bias value b caused by the inclination of the gyro spin axis with respect to the horizontal plane and the azimuth error caused by the motion of the navigation body. φ is determined by the detection signal SA, the azimuth signal Az, and the GPS signal GS.
Estimated equivalent bias value b which is an estimated value of equivalent bias value b
It is configured to calculate as an estimated azimuth angle error φe which is an estimated value of e and the azimuth angle error φ.

According to the present invention, in the gyro compass, the error correcting unit 100 'multiplies the estimated equivalent bias value be by a constant to generate a correction signal A1, and the azimuth angle caused by the equivalent bias value b by the correction signal A1. It is configured to correct the error φ.

According to the present invention, in the gyro compass, the error correcting unit 100 'receives the azimuth signal Az and the estimated azimuth error signal φe, and obtains the true azimuth angle which does not include the azimuth error φ from the difference between them. It is configured to generate a signal Azt.

[0084]

According to the present invention, instead of inputting the speed signal V 'and the latitude setting value λ ₀ ', the error calculating unit 100 'uses the GPS
Since the GPS signal GS received from the satellite is input, the Toruca signal TS is obtained as a value that does not include an error due to the inclination of the spin axis with respect to the horizontal plane, and the true azimuth signal Azt is obtained from the navigation vehicle. It is obtained as a value that does not include the azimuth error φ due to motion.

[0085]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a gyro compass of the present invention will be described below with reference to FIGS. 1 to 3
In FIG. 7, the same reference numerals are given to portions corresponding to FIGS. 4 to 11, and the detailed description thereof is omitted.

FIG. 1 shows an example of a gyro compass according to the present invention. The gyro compass has a mechanical section A and a control section B ′. The control unit B ′ has an error correction unit 100 ′ and a coefficient unit 31.

The difference between the configuration of the gyro compass of this embodiment shown in FIG. 1 and the configuration of the conventional gyro compass shown in FIG. 5 is that the error correction unit 100 of the present embodiment is used instead of the conventional error correction unit 100. A unit 100 'is provided, and in this example, a GPS unit 90 is newly provided. The mechanical section A of the gyrocompass of this example may be the same as the mechanical section A of the conventional gyrocompass.

The error correction unit 100 ′ of this embodiment includes a detection signal SA indicating the inclination angle of the spin axis with respect to the horizontal plane supplied from the inclinometer 30 and an azimuth indicating the azimuth of the spin axis supplied from the azimuth transmitter 22. The angle signal Az and the GPS signal supplied from the GPS unit 90 are input, and the correction signal A1 and the true azimuth signal Azt are calculated and output.

That is, comparing the error correction unit 100 ′ of the present example with the conventional error correction unit 100, the detection signal SA indicating the tilt angle of the spin axis with respect to the horizontal plane supplied from the inclinometer 30 and the azimuth transmitter 22 Although the azimuth signal Az indicating the azimuth of the spin axis supplied from the input unit is the same, the conventional error correction unit 100 uses the speed signal V ′ supplied from the log speedometer to indicate the speed of the navigator. And a latitude setting value λ ₀ ′ that indicates the latitude of the navigation object set manually or the like.
However, the difference is that the error correction unit 100 ′ of this example receives the GPS signal supplied from the GPS unit 90 instead. It is the same in that the correction signal A1 and the true azimuth signal Azt are calculated and output.

In recent years, GPS (Global Positi)
oning System) has been proposed. GPS
Is configured to detect the position, speed, azimuth, and the like of a navigating body such as a ship using radio waves from a satellite. In this method, radio waves transmitted from three to four satellites are constantly received, and the position, speed, azimuth, and the like of the vehicle are three-dimensionally measured based on data obtained thereby. 199
It is expected that GPS will be put into practical use when the launch of the satellite is completed in the 0's. GPS uses a C / A code, which is a private code.

Referring to FIG. 2, the configuration and function of the GPS unit 90 will be described. The GPS receiver used for the GPS is described in, for example, the document “Overview of GPS and Receiver”, No. 90 (December 1986), and refer to such document for details.

The GPS unit 90 may be configured to include an antenna 90-1, a preamplifier 90-2, and a reception processing unit 90-3.

The reception processing unit 90-3 includes the frequency conversion amplifier 9
0-4, spectrum despread demodulator 90-5, distance measuring device 90-6, Doppler measuring device 90-7, and orbit data collecting device 9
0-8, a position calculation unit 90-9, a speed calculation unit 90-10, a display unit 90-11, and an azimuth calculation unit 90-12 may be configured.

15575.42 by the antenna 90-1
MHz (L ₁ ) GPS signal is received and the GPS signal
The signal is supplied to a preamplifier 90-2, where it is amplified. In a navigation body such as a ship, the distance between the installation position of the antenna 90-1 and the reception processing unit 90-3 may be several tens of meters, and the GPS signal may be attenuated by the coaxial cable connecting the two. is there. Preamplifier 90-2
Is provided to compensate for such GPS signal attenuation.

The output signal of the preamplifier 90-2 is supplied to the frequency conversion amplifier 90-4 of the reception processing unit 90-3, where it is converted to an intermediate frequency and further amplified. The GPS signal thus frequency-converted and amplified includes a spread spectrum signal received from all satellites flying above the antenna. Therefore, it is necessary to extract a desired signal transmitted from, for example, four satellites from the GPS signal.

The output signal of the frequency conversion amplifier 90-4 is G
The PS signal is supplied to a spectrum despread demodulator 90-5 for spectrum despread demodulation. In the spectrum despread demodulator 90-5, the specific C / A codes assigned to the four satellites are generated in the reception processing unit 90-3, and the C / A codes and the frequency conversion amplifier 90- are generated. 4 to determine a correlation with the GPS signal output from the control unit 4.

For example, when trying to obtain GPS signals from desired four satellites, the received signals are subjected to the above-described spectrum despread demodulation to thereby obtain the same frequency (L) transmitted from the four satellites. The GPS signals of ₁ ) can be separated and demodulated.

The output signal of the spectrum despread demodulator 90-5 is supplied to a distance measuring device 90-6, a Doppler measuring device 90-7, and an orbit data collecting device 90-8.

The distance measuring device 90-6 is configured to measure the distance between the antenna and the satellite by, for example, the following method. The above-described spectrum despread demodulator 90
-5, for example, the phase of the C / A code is controlled such that the correlation between the C / A code generated in the reception processing unit 90-3 and the received GPS signal is maximized. It is assumed to be configured as Under such control, the phase of the C / A code generated in the reception processing unit 90-3 matches the phase of the received GPS signal. Therefore, C / C generated in the reception processing unit 90-3
By detecting the phase of the A code, the distance between the antenna and the satellite is measured.

The orbit data collector 90-8 is configured to detect orbit information at a transmission rate of 50 bps contained in the GPS signal subjected to the spectrum despread demodulation, and to collect the orbit data.

The output signals of the distance measuring device 90-6 and the trajectory data collecting device 90-8 are supplied to a position calculating section 90-9. In the position calculation unit 90-9, the orbit data collector 90-8 is used.
The orbital positions of the three satellites currently being received are accurately calculated from the orbital data supplied from the satellite, and the position data of the three satellites currently received and the distance between the antenna and the satellite supplied from the distance measuring device 90-6 are calculated. A quaternary simultaneous equation is established with the distance data. By solving such an equation by the successive approximation method, the position, latitude, and longitude of the antenna are obtained. The thus obtained latitude of the antenna is defined as GPS latitude signal λ _G ′
It is output from the S unit 90.

The Doppler measuring device 90-7 is configured to measure the frequency of the carrier wave included in the GPS signal subjected to the spectrum despread demodulation and calculate the Doppler shift of the GPS signal. Such a Doppler shift determines the rate of change of the distance between the antenna and the satellite.

Output signals from the Doppler measuring device 90-7 and the orbit data collecting device 90-8 are supplied to a speed calculating section 90-10. The speed calculator 90-10 includes a trajectory data collector 90.
The orbital motions of the four satellites currently being received are accurately calculated from the orbital data supplied from -8, and the motion data of the satellites and the antenna and satellite supplied from the Doppler measuring device 90-7 are calculated. The moving speed of the navigating body equipped with the antenna is calculated based on the change rate data of the distance between the two. The moving speed of the navigation body thus obtained is output from the GPS unit 90 as a GPS speed signal V _G ′.

The azimuth calculation unit 90-12 calculates the Doppler shift of the carrier wave included in the GPS signal, obtains a velocity vector based on the Doppler shift, and measures the azimuth of the movement of the navigation vehicle from the direction of the velocity vector. Is configured. Such an azimuth is output from the GPS unit 90 as a GPS azimuth signal Az _G ′.

Thus, the GPS signal GS provided by the GPS unit 90 is the GPS latitude signal λ _G ′
It includes a speed signal V _G ′ and a GPS azimuth signal Az _G ′.
The GPS speed signal V _G ′ is not affected by the tidal current speed, and therefore can be used as the speed V ′ of the navigating body in the model calculation unit 100A1. In addition, GPS
The speed signal V _G ′ corresponds to the trajectory speed V _P of the navigation body in FIG. 12, and the GPS azimuth signal Az _G ′ corresponds to the trajectory azimuth signal Az ′ of the navigation body.

Referring to FIG. 3, external information processing section 10 of the present embodiment
The configuration and operation of 0A3 'will be described. The external information processing unit 100A3 'of the present example of FIG. 3 and the conventional external information processing unit 1 of FIG.
The difference from the conventional external information processing unit 100A3 is that the conventional external information processing unit 100A3 inputs a latitude setting value λ ₀ ′, a speed signal V ′, and an azimuth signal Az. _{G includes a} GPS latitude signal λ _G ′, a GPS speed signal V _G ′, and a GPS azimuth signal Az _G ′.
The point is that the PS signal GS is input.

Further, the external information processing section 100A3 'of this example
The difference is that the integrator 64 for calculating the latitude λ ′ of the conventional navigator is eliminated. Therefore, the configuration of the external information processing unit 100A3 ′ in this example may be the same as that of the conventional external information processing unit 100A3 except that the three input signals and the integrator 64 are eliminated.

The operation of the external information processing section 100A3 'of this embodiment will be described with reference to FIGS. The GPS latitude signal λ _G ′ included in the GPS signal GS corresponds to the latitude signal λ ′ in FIG. 3, and the GPS speed signal V _G ′ and the GPS azimuth signal Az _G ′ are the trajectory velocity _VP and the trajectory azimuth in FIG. A
z '. This is represented by the following equation (8).

[0109]

[Equation 8] _{λ '= λ G' Az '} = Az G' V P = V G '

When the north-south velocity component V _N ′ and the east-west velocity component V _E ′ of the earth coordinate system are obtained, they are expressed by the following equation (9).

[0111]

[Equation 9] _{V N '= V P cosAz'} = V XL V E '= V P sinAz' = V YL

Thus, as shown by the equation (9),
Velocity component V_N′ And the east-west velocity component V _E’Is the trajectory azimuth A
z '. That is, according to this example,
Velocity component V_N′ And the east-west velocity component V_E’Is the skidding speed δ
Is determined in consideration of In addition, such a velocity component
V_N’, V_E'Is a value which is not affected by the tidal current speed.

Similarly, the external information processing section 100A of this example
In 3 ′, other signals calculated using the north-south velocity component V _N ′ and the east-west velocity component V _E ′ represented by the equation (9), that is, the north-south acceleration component σ _N ′ and the east-west acceleration component σ _E ', North-south angular velocity component ω _N ' and east-west angular velocity component ω
_E ′, the horizontal component Ω _c ′ and the vertical component Ω _s ′ of the equivalent earth rotation angular velocity are determined as accurate values.

Further, the estimated inclination angle signal θe, the estimated azimuth error signal φe, and the estimated equivalent bias value signal be calculated using the velocity components V _N ′ and V _E ′ in the model calculation unit 100A1 are accurate. Value.

As described above, according to the gyro compass of the present embodiment, the true azimuth signal Azt output from the error calculation unit 100 'of the control unit B' is an error caused by the movement of the navigation body such as a ship, such as turning and changing the course of a course. Since it does not contain any components, a very accurate heading azimuth can be provided to the outside.

Although the embodiments of the present invention have been described in detail, it is easy for those skilled in the art that the present invention is not limited to the above-described embodiments and can adopt various other configurations without departing from the gist of the present invention. Will be understood.

[0117]

According to the present invention, the gyro compass error caused by the movement of a navigation body such as a ship or the movement of a changing course is eliminated or minimized, so that the azimuth can be measured with high accuracy. There is an advantage that a gyro compass can be provided.

According to the present invention, since the GPS latitude signal λ _G ′ is used, an accurate latitude can be obtained, and further, there is an advantage that it is not necessary to manually set the latitude setting value λ ₀ as in the related art.

The gyro compass of the present invention is simply a G gyro without changing or modifying the mechanism of the conventional gyro compass.
Since it can be configured simply by adding the PS knit 90 and connecting the GPS knit 90 to the control unit by the GPS signal cable, there is an advantage that the manufacturing can be performed easily and inexpensively.

According to the present invention, when the speed signal of the conventional log signal is obtained, there is an advantage that the power flow speed can be obtained by using the first expression of the expression (8).

According to the present invention, when the speed signal of the conventional log signal is obtained, there is an advantage that the side slip speed and the side slip angle can be obtained by using the first equation of the equation (8).

According to the present invention, the equivalent bias value included in the detection signal indicating the inclination of the spin axis with respect to the horizontal plane, for example, the amount of mechanical unbalance torque around the horizontal axis, the inclination of the spin axis with respect to the horizontal plane including the spin axis There is an advantage that the drift amount that changes due to the mounting error angle of the meter 30 and the temperature of the inclinometer 30 can be corrected by the estimation calculation.

According to the present invention, the gains Kθ, Kφ, and Kb of the coefficient units 102, 103, and 104 of the error correction unit 100
Is adjusted to an appropriate value, the estimated azimuth angle error φb of the model calculation unit 100A1 can be changed to the azimuth angle error φ of the gyro compass.
Can be adjusted, so that the adjustment time until it becomes usable is short. For example, such an adjustment has an advantage that the adjustment is completed within one hour, which normally takes two hours.

The conventional log velocimeter has a drawback that when it is mounted on the fuselage of a ship, it must be machined and maintenance costs are high. However, according to the present invention, the GPS unit is easily mounted. It also has the advantage of low maintenance costs.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration example of a gyro compass of the present invention.

FIG. 2 is a diagram illustrating a configuration example of a GPS unit.

FIG. 3 is a diagram illustrating a configuration example of an external information processing unit of the present invention.

FIG. 4 is a diagram illustrating a configuration example of a mechanical unit of a conventional gyrocompass.

FIG. 5 is a diagram illustrating a configuration example of a conventional gyrocompass.

FIG. 6 is a diagram illustrating a configuration example of a conventional error correction unit.

FIG. 7 is a diagram illustrating a configuration example of a conventional model calculation unit.

FIG. 8 is a diagram illustrating a configuration example of a conventional error detection unit.

FIG. 9 is a diagram illustrating a configuration example of a conventional external information processing unit.

FIG. 10 is a diagram illustrating a configuration example of a conventional bias error correction unit.

FIG. 11 is a diagram illustrating a configuration example of a conventional azimuth error correction unit.

FIG. 12 is an explanatory diagram illustrating turning characteristics of a ship.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Gyro case 2, 2 'Vertical axis 3 Vertical ring 4, 4' Ball bearing 5 Suspension wire 5 'Suspension wire mount 6, 6' Liquid stabilizer 8 Tracking pickup 9, 9 'Horizontal axis 10 Horizontal ring 11, 11' Ball bearing 12, 12 'Gimbal shaft 13 Follower ring 14, 14' Ball bearing 15, 15 'Follower shaft 16 Board device 17, 17' Ball bearing 18 Compass card 18B Baseline 19 Azimuth servo motor 19A Rotation axis 20 Azimuth pinion 21 Azimuth gear Reference Signs List 22 direction transmitter 23 servo amplifier 30 inclinometer 31 coefficient unit 32 torquer 40 coordinate converter 50, 51 coefficient unit 52 integrator 53 coefficient unit 54 integrator 55 coefficient unit 56 integrator 60 north-south speed calculation unit 61 differentiator 62, 63 Coefficient unit 64 Integrator 70 East-West speed calculation unit 71 Differentiator 72 Coefficient unit 80, 81, 2 Coefficient unit 90 GPS unit 100, 100 'Error correction unit 100A Error calculation unit 100A1 Model calculation unit 100A2 Error detection unit 100A3 External information processing unit 100B Bias error correction unit 100C Azimuth error correction unit 101 Comparator 102, 103, 104, 107 , 108,109 Coefficient unit

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-178516 (JP, A) JP-A-3-245076 (JP, A) JP-A-62-169013 (JP, A) JP-A-63-1988 154914 (JP, A) JP-A-2-193011 (JP, A) JP-A-2-193012 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01C 19/00-19 / 54

Claims (5)

(57) [Claims] A gyro case having a built-in gyro having a substantially horizontal spin axis, a support device for supporting the gyro case with three degrees of freedom, and detecting an inclination angle of the spin axis with respect to a horizontal plane. An inclinometer that outputs a detection signal indicating the same, and a finger north device that applies a torque proportional to the inclination angle of the spin axis with respect to a horizontal plane to the gyro case around a horizontal axis orthogonal to the spin axis, A torquer that applies torque around the vertical axis of the gyro case based on the input torquer signal, and an azimuth transmitter that detects the azimuth of the spin axis with respect to the heading of the navigating body and outputs an azimuth signal indicating the direction. An antenna installed in the navigation body for receiving radio waves from GPS satellites, and amplifying the radio waves received by the antenna. A GPS unit having a preamplifier for outputting, a reception processing unit for inputting an output signal from the preamplifier and outputting a GPS signal, a detection signal output from the inclinometer, and an azimuth output from the azimuth transmitter A control unit that inputs a signal and the GPS signal output from the GPS unit, outputs a Toruca signal to the Toruca, and further generates a true azimuth signal indicating a true heading of the bow of the navigation body. The GPS signal includes a GPS latitude signal indicating the latitude of the installation position of the antenna, a GPS speed signal indicating the speed of the installation position of the antenna, and a GPS azimuth signal indicating the azimuth of the installation position of the antenna. And the ToruCa signal and the true azimuth signal are obtained as values that do not include errors caused by the tidal speed and the skidding speed of the vehicle. Gyro compass, wherein the door. 2. The gyro compass according to claim 1, wherein the control unit includes an error correction unit that inputs the detection signal, the azimuth signal, and the GPS signal, and outputs the true azimuth signal and a correction signal. A gyro compass, wherein the gyro compass is configured to generate a damping signal by multiplying the detection signal by a constant, and to correct the damping signal by the correction signal. 3. The gyro compass according to claim 2, wherein the error correction unit includes an equivalent bias value caused by the inclination of the spin axis of the gyro with respect to a horizontal plane and an azimuth error caused by the motion of the navigation vehicle. Is calculated as the estimated equivalent bias value that is the estimated value of the equivalent bias value and the estimated azimuth error that is the estimated value of the azimuth error using the detection signal, the azimuth signal, and the GPS signal. A gyrocompass characterized by being done. 4. The gyro compass according to claim 2, wherein the error correction unit generates the correction signal by multiplying the estimated equivalent bias value by a constant, and causes the correction signal to generate the correction signal. A gyrocompass configured to correct an azimuth error. 5. The gyro compass according to claim 2, wherein the error correction unit inputs the azimuth signal and a signal indicating the estimated azimuth error, and calculates the azimuth error based on a difference between the two signals. A gyro compass configured to generate a true azimuth signal that does not include the following.