JPH07240618A - Antenna directing device - Google Patents

Abstract

PURPOSE:To accurately and quickly direct an antenna in a satellite direction by providing a coordinate transformer for transforming the gyro signals of an antenna coordinate system to instruction signals to respective servo motors. CONSTITUTION:This device is provided with three gyros 56-58 and accelerometers 66-68 and directs the antenna 14 in the satellite direction by a horizontal axis control loop, an elevation angle axis control loop and a bearing axis control loop. In this case, the coordinate transformer 83 computes the required rotation angle omegaX of the antenna 14 around a horizontal axis line X-X for performing supply to the horizontal axis control loop and a required rotational angular velocity omegaZ around a bearing axis line Z-Z for performing the supply to the bearing axis control loop by the rotation angle omegaXA around the center axis line XA-XA of the antenna 14 outputted from the gyro 56, the rotational angular velocity omegaZA around the axis line ZA-ZA of the antenna 14 outputted from the gyro 58 and the rotation angle theta around the elevation angle axis line YA-YA of the antenna 14 outputted from an elevation angle originator 34.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna directing device for directing an antenna suitable for use in maritime satellite communications or the like toward a satellite.

[0002]

2. Description of the Related Art FIG. 5 shows an example of a conventional antenna pointing device. This antenna directing device is basically called an azimuth-elevation system, and has an antenna 14 and a supporting device that rotatably supports the antenna 14 around two axes. Such supporting device has a bearing axis Z-Z perpendicular to the central axis X _A -X elevation axis perpendicular to the _A Y-Y and such elevation axis Y-Y of the antenna 14. The azimuth axis ZZ is perpendicular to the mounting surface of the navigation body (hull surface), and the elevation axis YY is parallel to the mounting surface of the navigation body (hull surface).

The supporting device is a base 3, an azimuth gimbal 41 mounted on the base 3, and a U at the upper end of the azimuth gimbal 41.
The mounting member 31 is attached to the character-shaped member, and the antenna 14 is mounted on the mounting member 31.

The base 3 may have a bridge portion 3-1.
The bridge portion 3-1 has a cylindrical portion 11 protruding upward.
Is mounted, and a pair of bearings 40A and 40B is mounted inside the cylindrical portion 11. This bearing 4
The azimuth axis 40 is fitted to the inner rings of 0A and 40B,
An azimuth gimbal 41 is attached to the upper end of the azimuth axis 40 via the arm 13.

Thus, the azimuth axis 40 has the bearings 40A and 40B.
The azimuth gimbal 41 can rotate about an axis passing through the azimuth axis 40 while being supported by the azimuth gimbal 41. The azimuth gimbal 41 has a lower support shaft portion 41-1 and an upper U-shaped portion 41-2, and the center axis line of the support shaft portion 41-1 is deviated from the center axis line of the azimuth axis 40. Support shaft 41-1
The central axis of the arrow forms the azimuth axis ZZ.

On the U-shaped portion 41-2 of the orientation gimbal 41, a smaller U-shaped mounting member 31 is arranged, and the mounting member 31 has two legs 31-.
1 and 31-2 have elevation axes 30-1 and 30-2, respectively. A suitable bearing is mounted on each of the two legs of the U-shaped portion 41-2 of the azimuth gimbal 41, and the elevation shafts 30-1 and 30-2 are rotatably supported by the bearings.

The central axes of the elevation axes 30-1 and 30-2 form an elevation axis Y-Y, and thus the fitting 31 is between the two legs of the U-shaped portion 41-2 of the orientation gimbal 41. Is rotatably supported around the elevation axis Y-Y.

The leg portion 31 of the U-shaped fitting 31
The antenna 14 is mounted on the antennas 1 and 31-2.
It can rotate around Y.

An elevation gear 32 is mounted on one leg of the fitting 31 coaxially with the elevation axis Y--Y. A pinion 33-1 is meshed with the elevation gear 32, and the pinion 33-1 is mounted on one leg of the U-shaped portion 41-2 of the azimuth gimbal 41. Is attached to.

An elevation transmitter 34 is mounted on one leg of the U-shaped portion 41-2 of the azimuth gimbal 41, and the elevation transmitter 34 attaches the elevation transmitter Y to the elevation axis YY.
A rotation angle θ around the rotation angle is detected and a signal indicating the rotation angle θ is output.

On the other hand, the azimuth gear 4 is provided at the lower end of the azimuth axis 40.
2 is attached, and the azimuth servo motor 43 and the azimuth transmitter 44 are attached on the bridge portion 3-1 of the base 3.
Pinions (not shown) attached to the rotation shafts of the azimuth servo motor 43 and the azimuth transmitter 44 are configured to mesh with the azimuth gear 42.

The mounting bracket 31 has an elevation gyro 57.
And an azimuth gyro 58 are attached. Antenna 1 which rotates around an elevation axis YY by an elevation gyro 57
4 the rotational angular velocity is detected and the center axis of the elevation axis Y-Y and the antenna 14 by the azimuth gyroscope 58 X _A -X _A
The angular velocity of rotation of the antenna 14 around the axis orthogonal to the two is detected.

The elevation gyro 57 and the azimuth gyro 58 are
For example, in addition to an integral type gyro such as a mechanical gyro and an optical gyro, an angular velocity detection gyro such as a vibration gyro, a rate gyro, and an optical fiber gyro may be used.

The mounting bracket 31 further includes a first accelerometer 66, a second accelerometer 67, and a third accelerometer 68.
Is installed. The inclination angle of the central axis X _A -X _A of the antenna 14 around the elevation axis Y-Y is detected by the first accelerometer 66, about the central axis X _A -X _A of the antenna 14 by the second accelerometer 67 The tilt angle is detected.

The third accelerometer 68 is the first accelerometer 66.
And the second accelerometer 67 are mounted so as to be orthogonal to each other, that is, to have an input axis line that is orthogonal to both the input axis line of the first accelerometer 66 and the input axis line of the second accelerometer 67. It is attached. Thus, the third accelerometer 68 detects an inclination angle with respect to the horizontal plane of the axis perpendicular to both the central axis X _A -X _A and elevation axis Y-Y of the antenna 14.

As shown, an elevation axis control loop and an azimuth axis control loop are provided to control the antenna 14. The angle formed by the center axis X _A -X _{A of} the antenna 14 and the horizontal plane is the elevation angle θ _A of the antenna, and the angle formed by the center axis X _A -X _{A of} the antenna 14 and the meridian N on the horizontal plane is the azimuth angle φ of the antenna. _A.

The azimuth axis control loop controls the azimuth gimbal 4 so that the azimuth angle φ _A of the antenna 14 matches the satellite azimuth angle φ _S.
1 (antenna 14) is configured to control the azimuth and includes a fast control loop, ie, an azimuth axis stabilization loop and a slow control loop, ie, an azimuth constraint loop.

The fast control loop, ie, the azimuth axis stabilization loop, includes an azimuth gyro 58, an integrator 47, an amplifier 46 and an azimuth servomotor 43, whereby the antenna 14
Is the central axis X _A -X _A and the elevation axis Y of the antenna 14.
It can be stabilized against rotational movement of the hull about an axis that is orthogonal to both -Y.

The slow control loop, that is, the azimuth angle constraining loop, includes an azimuth oscillator 44, an adder 49, an attenuator 48, and an integrator 4.
7, an amplifier 46, and an azimuth servo motor 43. The adder 49 subtracts the satellite azimuth angle φ _S from the sum of the bow azimuth angle φ _C and the rotation angle φ of the antenna 14 output from the azimuth transmitter 44, and outputs the deviation angle. When the deviation angle output from the adder 49 becomes zero, that is, the rotation angle φ of the antenna
And the bow azimuth angle φ _C becomes equal to the satellite azimuth angle φ _S , the azimuth of the antenna 14 is stationary.

The elevation axis control loop is configured to rotate the antenna 14 about the elevation axis Y--Y so that the antenna elevation angle θ _A matches the satellite elevation angle θ _S , a fast control loop, namely the elevation axis It includes a stabilization loop and a slow control loop, namely an elevation constraint loop. Fast control loop,
That is, in the elevation axis stabilization loop, the elevation gyro 57
Is fed back to the elevation angle servo motor 33 via the elevation angle axis control integrator 37 and the amplifier 36. As a result, even if the hull oscillates, the antenna 14 against the inertial space
The angular velocity about the elevation axis Y-Y of is always held at zero.

The slow control loop, that is, the elevation angle constraining loop includes an antenna elevation angle calculation unit 81, an adder 39, an attenuator 38, an integrator 37, an amplifier 36, and an elevation angle servomotor 33. The elevation angle θ _A of the antenna 14 obtained by the antenna elevation angle calculation unit 81 is reduced by a signal indicating the satellite altitude angle θ _S manually set by the adder 39,
The deviation angle is output.

When the deviation angle signal output from the adder 39 becomes zero, that is, the elevation angle θ of the antenna is the satellite altitude angle θ.
When equal to _S , the rotational movement of the antenna 14 about the elevation axis YY is stationary.

This loop has a suitable time constant for matching the elevation angle θ _{A of the} antenna 14 to the satellite elevation angle θ _S. It should be noted that the attenuator 38 may be provided with an integral characteristic in order to compensate for the drift fluctuation of the elevation angle gyro 57.

Thus, the antenna 14 is controlled by its elevation axis control loop and azimuth axis control loop so that the antenna 14 has its center axis X _A -X.
_A is configured to point toward the satellite.

The antenna elevation angle calculation unit 81 inputs the output signals of the three-axis accelerometers composed of the first, second and third accelerometers 66, 67 and 68 which are orthogonal to each other, and the elevation angle θ _{A of the} antenna 14, that is, , The tilt angle of the central axis X _A -X _A of the antenna 14 with respect to the horizontal plane is calculated. Such calculation includes performing arctangent calculation from the tangent of the elevation angle θ _A of the antenna 14, thereby obtaining the value of the elevation angle θ _A of the antenna 14 and its quadrant.

Referring to FIG. 6, the antenna elevation angle calculation unit of this example
The function and operation of 81 will be described. Figure 6 shows a unit spherical surface with a radius of 1.
Considering such a unit spherical surface and the central axis X of the antenna 14,_A
-X _A(Line segment OX in FIG. 2), elevation axis YY (see FIG. 2)
Line segment OY, OY ') and azimuth axis line ZZ (in FIG. 2)
It is a figure which shows the relationship of line segment OZ, OZ '.

The hull surface (mounting surface) is rotated about the elevation axis YY (OY) with respect to the horizontal plane by a rotation angle ξ, and is further rotated by another rotation angle η around another axis line, for example, the hull tail line OE. And The azimuth axis ZZ perpendicular to the hull surface (mounting surface) moves from the line OZ to the line OZ ', and the elevation axis YY moves from the line OY to the line OD. In addition, ∠XOD
= 90 °.

The antenna 1 is moved by the movement of the hull surface.
Although also moves the fourth central axis X _A -X _A, the center axis X _A -X _A of the antenna 14 is controlled to direct the satellite direction by the control loop. That is, the central axis X _A -X antenna 14 _A is moved from line OX to move again the line OX to position biased.

At this time, the elevation axis YY is the azimuth axis OZ '.
It rotates around the rotation angle Δφ and moves from the line OD to the line OY ′. Incidentally, ∠XOY '= 90 °. The line OP orthogonal to both the central axis X _A -X _A and elevation axis Y-Y of the antenna 14 is moved to line OP '.

The line OX, the line OY, and the line OP are lines of length 1 orthogonal to each other, and the triangle XYP is an equilateral spherical triangle with one side of π / 2. The line OX, the line OY ', and the line OP' are also lines of length 1 orthogonal to each other, and the triangle XY'P 'is an equilateral spherical triangle with one side of π / 2. A point X is connected to a point P and a point P ′ by a straight line on the unit spherical surface. The arc XP is orthogonal to the horizontal plane at the point A and further orthogonal to the plane OY'P 'at the point P. The arc XP ′ is orthogonal to the hull surface (mounting surface) at the point C, and is further orthogonal to the surface OY′P ′ at the point P ′. The foot of the perpendicular line drawn from the point P ′ to the horizontal plane is A ′, and the foot of the perpendicular line drawn from the point Y ′ to the horizontal plane is B ′.

When the hull surface is the same as the horizontal plane, sin ∠XOA is detected by the first accelerometer 66 and the second accelerometer 66 detects
The accelerometer 67 detects sin∠YOB, and the third accelerometer 68 detects sin∠POA. The elevation angle θ _{A of the} antenna 14 is equal to the altitude angle θ _S of the satellite and is the elevation angle of the satellite with respect to the horizontal plane, so ∠XOA = θ _A
Is. Also, since ∠XOP = 90 °, ∠POA = ∠
XOA−∠XOP = θ _A −90 °. Here, a positive angle was made in the direction of the satellite's altitude θ _S with respect to the horizontal plane, and a negative angle was made in the opposite direction. Therefore, the first accelerometer 66 detects sin θ _A , the second accelerometer 67 detects sin 0 = 0, and the third accelerometer 68 detects sin (θ _A −90 °) = − cos θ _A. To be done.

The value detected by the first value sin [theta _A detected by the accelerometer 66 third accelerometer _{68 sin (θ A -90 °)} = - relationship between cos [theta] _A is represented by the following formula It

[0033]

[Number 1] _{tanθ A = sinθ A / cosθ A} = -sinθ A / sin (θ A -90 °) = -sinθ A / sin∠POA

The hull surface is an elevation axis YY with respect to the horizontal plane.
When it rotates about (OY) by the rotation angle ξ, and further about the hull's tail line OE about the rotation angle η, sin ∠XOA is detected by the first accelerometer 46 and sin ∠ by the second accelerometer 47. Y'OB 'detected, third
Sin ∠P'OA 'is detected by the accelerometer 48 of. Since the altitude angle θ _S (= θ _A ) of the satellite is irrelevant to the motion of the hull surface, the value detected by the first accelerometer 66 is sin∠XOA = sin θ _A and does not change.

Let ε be the angle between the line OP and the line OP '. That is, ∠POP '= ∠Y'OY = ε. However,

[0036]

Tan ε = sin ∠Y'OB '/ sin ∠P'OA'

It is Applying the sine theorem of spherical trigonometry to ΔA'YP 'and ΔB'YY',

[0038]

(3) sin∠AYP = sin∠Y′OB ′ / sinε = sin∠P′OA ′ / cosε = sin∠POA

It becomes Therefore, the following two equations are required.

[0040]

(4) sin∠Y′OB ′ = sin∠POA · sinε sin∠P′OA ′ = sin∠POA · cosε

Here, the following replacement is performed.

[0042]

## EQU5 ## g ₁ = g ₀ sin θ _A g ₂ = g ₀ sin ∠Y'OB 'g ₃ = g ₀ sin ∠P'OA'

That is, the gravitational acceleration is g ₀ , the output signal of the first accelerometer 66 is g ₁ , the output signal of the second accelerometer 67 is g _2, and the output signal of the third accelerometer 68 is g ₃ Substituting these into the formula of Equation 4, si
By multiplying n ε and cos ε and solving for sin ∠ POA, the following equation is obtained.

[0044]

[Equation 6] sin ∠ POA = (g ₂ / g ₀ ) sin ε +
(G ₃ / g ₀ ) cosε

Substituting this into the denominator of the equation (1) and substituting the first equation of the equation (5) into the numerator of the equation (1), the following equation (7) is obtained.

[0046]

Tan θ _A = −g ₁ / (g ₂ sin ε + g ₃ cos ε) tan ε = g ₂ / g ₃

[0047] Thus, the value of the tangent of the elevation angle theta _A of the antenna 14 by the number 7 expression in this example is determined, the elevation angle theta _A of the antenna 14 is obtained by determining the value of the arctangent of the value. Since the right side of the first expression of Expression 7 has positive and negative values, it is possible to determine the quadrant of the elevation angle θ _A up to the fourth quadrant.

[0048]

In the conventional antenna directing device, the antenna 14 is mounted on the elevation axis YY and the azimuth axis Z.
Since the antenna is controlled around the two axes of -Z, it takes time to accurately orient the antenna 14 in the satellite direction, and the antenna 14 has to be frequently rotated around the two axes.

There is also known an example in which the antenna 14 is controlled to rotate about three axes. However, in such a three-axis control system, since the antenna 14 is independently controlled around the three axes, the antenna 14 cannot be oriented in the satellite direction with high accuracy.

Further, the conventional antenna directing device uses the gyros 57 and 58, and therefore has a drawback that an error caused by the drift of the gyro occurs.

Instead of using the elevation and azimuth control loops as described above to orient the antenna 14 in the satellite direction, step track control is known. This step track type control is performed by the antenna 14
The antenna 14 is rotated periodically around the rotation axis.
Is configured to measure the radio field intensity received by the antenna and rotate the antenna 14 in a direction in which the radio field intensity increases.

Therefore, such step-track control has the advantage that the error due to the gyro drift does not occur because the antenna 14 can be directed toward the satellite without using the gyro. However, it has a drawback that it does not operate when the navigation body is traveling in a tunnel or near a building and the reception of radio waves is interrupted.

In view of such a point, the present invention is directed to the antenna 14
It is an object of the present invention to provide an antenna directing device capable of accurately and quickly directing a satellite toward a satellite.

[0054]

According to the present invention, for example,
As shown in FIG. 1, the central axis X_A-X_AAnte with
And the central axis X of the antenna 14._A-X_AOrthogonal to
Elevation axis Y_A-Y _AAnd the horizontal axis XX and the horizontal axis
The azimuth axis ZZ orthogonal to
The antenna 14 is rotatably supported around the above three axes.
Support device and the central axis X_A-X_AInput axis parallel to
The first gyro 56 having the_A-Y
_AA second gyro 57 having an input axis parallel to
Center axis X_A-X_AAnd the elevation axis Y above_A-Y_ABoth
A third gyro 58 having an input axis orthogonal to the
Elevation axis Y above the line_A-Y_AAnte above
Elevator transmitter 3 that outputs a signal that indicates the rotation angle of the rotor 14
4 and the antenna 14 around the horizontal axis XX.
The horizontal axis control loop for turning control and the antenna 14 are
Elevation axis Y_A-Y_AElevation axis control loop to control rotation around
And the antenna 14 are rotated around the azimuth axis ZZ.
And an azimuth axis control loop for controlling the antenna 14.
Central axis X_A-X_ATo orient the satellite toward the satellite
And a device configured to be mounted on a navigation body.
In the antenna-oriented device, from the first gyro 56
The central axis X of the output antenna 14 is output._A-X_A
Rotational angular velocity around ω_XAAnd from the third gyro 58 above
The center axis X of the antenna 14 under force_A-X_AWhen
Above elevation axis Y_A-Y_AAxis Z orthogonal to both_A-Z
_ARotational angular velocity around ω_ZAAnd output from the elevation transmitter 34 above
The elevation axis Y of the antenna 14_A-Y_AAround
The rotation angle θ of the
Of the antenna 14 around the horizontal axis X-X for
Rotational angular velocity ω_XAnd to feed the above azimuth control loop
Required angular velocity ω around the azimuth axis Z-Z_ZCalculate
A coordinate converter 83 is provided for this purpose.

According to the present invention, as shown in, for example, FIG. 1 and FIG.
4, a step track control unit 84-1 for generating a step track signal in order to direct 4 to the satellite direction by the step track system, and the three gyros 56, 57,
And a gyro drift calculation unit 84 having a gyro drift correction unit for correcting the gyro drift of 58, and the step track control unit 84-1 has a radio field intensity signal E indicating the radio field intensity received by the antenna 14.
A step track signal ΔS _Y for inputting _S to correct the output signal of the second gyro 57 and a step track signal ΔS _Z for correcting the output signal of the third gyro 58.
And the gyro drift correction unit inputs the step track signal to correct a drift correction signal Δω _Y for correcting the output signal of the second gyro 57 and a drift correction signal for correcting the output signal of the third gyro 58. Correction signal Δ
and is configured to generate ω _Z and.

According to the present invention, for example, as shown in FIGS. 1 and 3, in the antenna directing device, the gyro drift correction section holds the drift correction signals Δω _Z and Δω _Y by a hold device 84-6. , 84-7,
When the radio wave intensity signal E _S is cut off, the drift correction signals Δω _Z and Δω _Y stored in the hold devices 84-6 and 84-7 are output.

According to the present invention, for example, as shown in FIG. 1, in the antenna directing device, the first accelerometer 6 for detecting the inclination angle of the central axis X _A -X _A with respect to the horizontal plane.
6, a second accelerometer 67 for detecting an inclination angle of the elevation axis Y _A -Y _A with respect to the horizontal plane, perpendicular to both the elevation axis Y _A -Y _A and the center axis X _A -X _A with respect to the horizontal plane _A third accelerometer 68 for detecting the inclination angle of the axis Z _A -Z _A , and an antenna elevation angle calculator 81 for calculating the elevation angle of the antenna 14 from the output signals of the three accelerometers 66, 67, 68. , And the antenna elevation angle calculation unit 8
The elevation angle signal θ _A of the antenna obtained by 1 is supplied to the elevation axis control loop.

[0058]

According to the present invention, the coordinate converter 83 is provided, and the coordinate converter 83 includes three gyros 56,
The angular velocity signals ω _XA , ω _YA , and ω _ZA of the antenna coordinate system obtained by 57 and 58 are supplied to the servo motors 23, 33, and 34, respectively.
Is configured to be converted into the angular velocity signals ω _X , ω _Y , and ω _Z supplied to the.

According to the present invention, the gyro drift computing unit 84 is provided, and the gyro drift computing unit 84 corrects the error caused by the gyro drift and the error caused by the movement of the satellite. It has a correction function, and such a gyro drift correction function is configured to use step track control.

[0060]

Embodiments of the present invention will be described below with reference to FIGS. FIG. 1 shows an example of an antenna pointing device of the present invention. This antenna directing device has an antenna 14 and a supporting device that rotatably supports the antenna 14 around three axes. Such a support device has an azimuth axis ZZ perpendicular to the mounting surface (hull surface) of the navigation body and a horizontal axis X-X orthogonal to the azimuth axis ZZ and parallel to the mounting surface (hull surface) of the navigation body. And the central axis X _A of the antenna 14
And a elevation axis Y _A -Y _A perpendicular to the _A.

[0061] Antenna 14 can be rotated in the elevation axis Y _A -Y _A, around three axes of the horizontal axis X-X and azimuthal axis Z-Z. The azimuth axis Z-Z is fixed with respect to the mounting surface (hull surface) of the navigation body, but the horizontal axis X-
X is the azimuth axis Z with respect to the mounting surface of the navigation body (hull surface)
It rotates around -Z and is always on a plane perpendicular to the azimuth axis ZZ. The elevation axis Y _A -Y _A rotating in the horizontal axis X-X about always lies on a plane perpendicular to the horizontal axis X-X.

The supporting device has a base 3 and an azimuth axis 40 mounted on the upper surface of the bridge portion of the base 3, and the azimuth axis 40 is perpendicular to the mounting surface (hull surface) of the navigation body. It is arranged. At the upper end of the azimuth axis 40, the azimuth gimbal 41
Is attached, and the azimuth gear 42 is attached to the lower end. An azimuth servo motor 43 is arranged on the upper surface of the bridge portion of the base 3, and the azimuth servo motor 43
A pinion (not shown) attached to the rotating shaft of the is configured to mesh with the azimuth gear 42.

The horizontal gimbal 21 is rotatably mounted on the azimuth gimbal 41. The horizontal gimbal 21 has a horizontal shaft 20, and a horizontal gear 22 is mounted on the horizontal shaft 20. Horizontal servo motor 2 is used for the azimuth gimbal 41.
3 is mounted, and the pinion 23-1 mounted on the rotary shaft of the horizontal servomotor 23 is configured to mesh with the horizontal gear 22.

An elevation gimbal 31 is rotatably mounted on the horizontal gimbal 21. The elevation gimbal 31 has an elevation axis 30, and an elevation gear 32 is mounted on the elevation axis 30. The elevation gimbal 31 has an elevation servo motor 3
3 is mounted, and the pinion (not shown) mounted on the rotary shaft of the elevation servomotor 33 is an elevation gear 32.
Is configured to mesh with.

[0065] central axis of the horizontal shaft 20 constitutes a horizontal axis X-X, the central axis of the elevation shaft 30 constitutes an elevation axis Y _A -Y _A, the center axis of the azimuth axis 40 and azimuth axis Z-Z Constitute.

The antenna 14 is attached to the elevation gimbal 31. Elevation pinion (not shown) mounted on the servo motor 33 is actuated rotating shaft elevation servomotor 33 and elevation axis Y _A -Y _A around relative elevation gimbal 31 is horizontal gimbal 21 via the elevation gear 32 Rotate to. Whereby the antenna 14 also rotates the elevation axis Y _A -Y _A about the horizontal gimbal 21.

When the horizontal servomotor 23 is operated, the pinion 23-mounted on the rotary shaft of the horizontal servomotor 23-
The horizontal gimbal 21 rotates about the horizontal axis XX with respect to the azimuth gimbal 41 via the 1 and the horizontal gear 22. Thereby, the antenna 14 also rotates about the horizontal axis XX with respect to the azimuth gimbal 41.

When the azimuth servo motor 23 is actuated, the azimuth axis 40 and the azimuth gimbal 41 are attached via the pinion (not shown) attached to the rotary shaft of the azimuth servo motor 43 and the azimuth gear 42 to the mounting surface of the navigation body (hull). Rotation about the azimuth axis ZZ with respect to the (plane). Antenna 1
4 is the azimuth axis Z with respect to the mounting surface of the navigation body (hull surface)
-Rotate around Z.

An elevation transmitter 34 is attached to one leg of the elevation gimbal 31, and a pinion (not shown) attached to the rotary shaft of the elevation transmitter 34 is configured to mesh with the elevation gear 32. Has been done. The elevation angle transmitter 34 detects the rotation angle θ of the antenna 14 around the elevation angle axis Y _A -Y _{A and} outputs a signal indicating the rotation angle θ.

On the other hand, an azimuth transmitter 44 is mounted on the upper surface of the bridge portion of the base 3, and a pinion (not shown) attached to the rotary shaft of the azimuth transmitter 44 is engaged with the azimuth gear 42. Is configured. The azimuth transmitter 44 detects the rotation angle φ of the antenna 14 (azimuth gimbal 41) around the azimuth axis ZZ and outputs a signal indicating the rotation angle φ.

For the antenna 14 or the elevation gimbal 31,
First, second and third gyros 56, 57 and 58 and first, second and third accelerometers 66, 67 and 68 are mounted. As shown, such a gyro and accelerometer have triaxial input axes (indicated by arrows) that are orthogonal to each other.

The first gyro 56 is the center of the antenna 14.
Axis X_A-X_AWith an input axis parallel to
Center axis X of tenor 14_A-X_AAround the antenna 14 around
Detects angular velocity. The second gyro 57 has an elevation axis Y.
_A-Y_AHas an input axis parallel to, that is, the elevation axis Y
_A-Y_AThe rotational angular velocity of the surrounding antenna 14 is detected.
The third gyro 58 has an elevation axis Y._A-Y_AAnd antenna
14 center axis X_A-X_AAxis Z orthogonal to both_A−
Z_AWith an input axis parallel to, ie axis Z _A-Z_A
The rotational angular velocity of the surrounding antenna 14 is detected.

The first, second and third gyros 56, 5
Reference numerals 7 and 58 may be, for example, an integral type gyro such as a mechanical gyro or an optical gyro, or an angular velocity detection gyro such as a vibration gyro, a rate gyro, or an optical fiber gyro.

The first accelerometer 66 is used to measure the horizontal plane.
Central axis X of the antenna 14_A-X _AAngle of inclination detected
And the elevation angle with respect to the horizontal plane is set by the second accelerometer 67.
Axis Y_A-Y_AThird accelerometer for detecting the tilt angle of
The elevation axis Y with respect to the horizontal plane by 68_A-Y_AAnd
Center axis X of antenna 14_A-X_AAxis orthogonal to both
Z_A-Z_AIs detected.

As shown in the figure, the antenna directing device of this example includes a horizontal axis control loop for supplying a command signal to the horizontal servo motor 23 and an elevation angle control loop for supplying a command signal to the elevation servo motor 33. Azimuth servo motor 4
And an azimuth control loop for supplying a command signal.

The central axis X of the antenna 14_A-X_ABut
The angle between the antenna and the horizontal plane is θ _AAnd antenna 1
Central axis X of 4_A-X_AIs an angle with the meridian N on a horizontal plane
The azimuth angle φ of the antenna_AAnd Also, in the figure, the antenna
Elevation angle calculation unit 81, elevation angle axis inclination calculation unit 82, coordinate converter
83 and functions of the gyro drift calculator 84.
I will explain later.

[0077] Horizontal axis control loop is configured to rotate the antenna 14 as the elevation axis Y _A -Y _A is horizontal to the horizontal axis X-X around fast control loop, i.e., the horizontal axis X- It includes a horizontal axis stabilization loop about X and a slow control loop, ie, a horizontal axis constraining loop about horizontal axis XX.

The fast control loop, ie, the horizontal axis stabilization loop, includes a coordinate converter 83, an integrator 27, an amplifier 26 and a horizontal servomotor 23. This allows the antenna 14
Can be stabilized with respect to the inertial space even if the navigation body makes a rotational movement about the horizontal axis XX, that is, the angular velocity about the horizontal axis XX of the antenna 14 with respect to the inertial space is always zero. Held in.

The slow control loop, that is, the horizontal axis constraining loop includes the elevation axis tilt calculator 82, the attenuator 28, the integrator 27, the amplifier 26, and the horizontal servomotor 23. When the rotation angle signal ψ (the rotation angle of the antenna 14 around the horizontal axis XX) output from the elevation axis tilt calculator 82 becomes zero,
The antenna 14 is stationary about the horizontal axis XX.

The elevation axis control loop is configured to rotate the antenna 14 about the elevation axis Y _A -Y _A so that the elevation angle θ _A of the antenna matches the satellite elevation angle θ _S , a fast control loop, namely: It includes an elevation stabilization loop and a slow control loop, namely an elevation constraint loop.

The fast control loop, that is, the elevation axis stabilization loop includes an adder 71, an integrator 37, an amplifier 36, and an elevation servomotor 33. The adder 71, the elevation axis output from the second gyro 57 Y _A -Y angular velocity omega _YA and step tracking signal supplied from the gyro drift calculator 84 of _A around the antenna 14 [Delta] S _Y the gyro drift correction signal Δω _Y is added and the signal is output.

[0082] This antenna 14 also sail body is rotational movement about the elevation axis Y _A -Y _A, can be stabilized against inertial space, that is, the elevation axis of the antenna 14 with respect to inertial space Y _a -Y _a angular velocity around is always held at zero.

The slow control loop, that is, the elevation angle restraint loop includes an antenna elevation angle calculation unit 81, an adder 39, an attenuator 38, an integrator 37, an amplifier 36, and an elevation angle servomotor 33. The adder 39 subtracts, for example, the manually set satellite altitude angle θ _S from the elevation angle θ _{A of the} antenna 14 output from the antenna elevation angle calculation unit 81, and outputs the deviation angle obtained thereby.

When the deviation angle signal output from the adder 39 becomes zero, that is, the elevation angle θ _{A of} the antenna changes to the satellite altitude angle θ.
Becomes equal to _S, the antenna 14 is the elevation axis Y _A -Y _A
Still around. This loop is the elevation angle θ of the antenna 14.
_It has an appropriate time constant for matching _A to the satellite altitude angle θ _S.

The azimuth axis control loop is arranged so that the azimuth angle φ _A of the antenna 14 matches the satellite azimuth angle φ _S.
It is configured to control the azimuth angle of the (azimuth gimbal 41) and includes a fast control loop, ie, the azimuth axis stabilization loop and a slow control loop, ie, the azimuth axis constraint loop.

The fast control loop, that is, the azimuth axis stabilization loop, includes the coordinate converter 83, the integrator 47, the amplifier 46, and the azimuth servomotor 43. This allows the antenna 14
Can be stabilized with respect to the inertial space even if the navigation body makes a rotational movement about the azimuth axis ZZ, that is, the angular velocity about the azimuth axis ZZ of the antenna 14 with respect to the inertial space is always zero. Held in.

The slow control loop, that is, the azimuth axis constraint loop includes an adder 49, an attenuator 48, an integrator 47, an amplifier 46, and an azimuth servo motor 43. The adder 49 uses the antenna azimuth φ _C and the antenna 14 output from the azimuth transmitter 44.
The satellite azimuth angle φ _S is subtracted from the sum of the rotation angle φ and the rotation angle φ, and the resulting deviation angle is output. When the deviation angle signal output from the adder 49 becomes zero, that is, when the azimuth angle φ of the antenna becomes equal to the azimuth angle φ _{S of the} satellite, the antenna 1
4 rests around the azimuth axis ZZ.

According to this example, step-track type control is further provided. Such step-track control will be described later. Thus, the horizontal axis control loop, elevation angle axis control loop, and azimuth axis control loop
Antenna 14 is the central axis X _A -X _A is configured to direct the satellite direction by the control of the axis control and step tracking method.

Referring to FIG. 2, the operation of the coordinate converter 83 of the present example.
Explain the work. Where azimuth gimbal coordinates and antenna seat
Set the mark. The azimuth gimbal coordinates are fixed on the azimuth gimbal 41.
It is a fixed coordinate system, and the horizontal axis X-X is the X axis and the horizontal axis.
The axis line orthogonal to both the line XX and the azimuth axis line ZZ is Y.
The axis and the azimuth axis Z-Z are the Z axis. Antenna coordinates are
It is a coordinate system fixed to the tenor 14, inside the antenna 14.
Core axis X_A-X_AX axis, elevation axis Y_A-Y_AIs the Y-axis,
Center axis X of antenna 14_A-X_AAnd elevation axis Y _A-Y
_AAxis Z orthogonal to both_A-Z_AIs the Z axis.

[0090] The three gyros 56, 57, 58 is attached directly to the antenna 14, the output signal, the three-axis (X _A -X _A of the antenna _{coordinates, Y A -Y A, Z A} -Z
_A ) Rotational angular velocity signals of the antenna 14 around ω _XA , ω _YA ,
It is ω _ZA . On the other hand, in the three control loops, the command signal supplied to the horizontal servo motor 23 is the angular velocity signal around the X axis of the azimuth gimbal coordinate, and the elevation servo motor 3
The command signal supplied to 3 is an angular velocity signal around the Y axis of the antenna coordinates, and the command signal supplied to the azimuth servomotor 43 is an angular velocity signal around the Z axis of the navigation body coordinates.

The coordinate converter 83 is obtained by a gyro.
Angular velocity signal ω in the antenna coordinate system_XA, Ω_YA, Ω_ZAEach service
Command angular velocity signal supplied to servomotors 23, 33, 34
Issue ω _X, Ω_Y, Ω_ZIs configured to convert to.

[0092] The second gyro 57, so that its input axis is parallel to the elevation axis Y _A -Y _A, assumed to be mounted on the antenna 14. Since the command signal supplied to the elevation angle servo motor 33 is the angular velocity signal around the Y axis of the antenna coordinates, the angular velocity signal ω _YA (= ω _Y ) output from the second gyro 57 does not need to be converted and should be used as it is. You can

Therefore, here, the command angular velocity signals ω _X supplied to the respective servo motors 23, 33, 34 using the rotational angular velocity signals ω _XA , ω _ZA output from the first and third gyros 56, 58. , Ω _Y , ω _Z are generated.

As shown, when the gyro output signal expressed in the antenna coordinate system is expressed in the azimuth gimbal coordinate system, the following equation holds.

[0095]

[Formula 8] ω _X = ω _XA cos θ−ω _ZA sin θ ω _Y = ω _YA ω _Z = ω _XA sin θ + ω _ZA cos θ

Here, ω _XA , ω _YA , and ω _ZA are gyro 5
Antenna coordinate system of the angular velocity obtained by 6,57,58, ω _X, ω _Y, the omega _Z orientation thereof gimbal coordinate system of the angular velocity, theta is the angle of rotation of the antenna 14 around the elevation axis Y _A -Y _A .

The coordinate converter 83 of this example is configured to perform the operation of the equation (8) and has an adder and a coefficient unit.

Next, the function and configuration of the gyro drift calculator 84 of this example will be described with reference to FIG. The gyro drift calculator 84 has a step track control function for directing the antenna 14 toward the satellite by the step track method, and a gyro drift correction function for correcting an error caused by the gyro drift and an error caused by the movement of the satellite. Have.

First, the step track control function will be described. The step track control measures the radio field intensity received by the antenna 14 while periodically moving the antenna 14 around a predetermined rotation axis, and rotates the antenna 14 in a direction in which the radio field intensity increases. a central axis X _a -X _a is configured to direct the satellite direction.

In this example, the step track control is used in combination with three control loops of a horizontal axis control loop, an elevation axis control loop and an azimuth axis control loop. For simplicity, the control function of the horizontal axis control loop, the elevation axis Y _A -Y _A is assumed to be arranged horizontally. Therefore, the step track control operates for the elevation axis control loop and the azimuth axis control loop.

According to the step track control of this example,
Without changing the antenna 14 to the elevation axis Y_A-Y_AAnd azimuth axis Z
-Periodically with a predetermined angular amplitude ± δθ and ± δφ around Z
Rotate to find the direction of rotation in which the radio field strength increases. Next
The antenna 14 to the elevation axis Y _A-Y_AAnd azimuth axis Z
-A predetermined rotation angle in the rotation direction where the radio field intensity increases around Z
Rotate at. Repeat these two steps
The central axis X of the antenna 14 so that the strength is maximized_A−
X_ATo move.

The step track controller 84-1 inputs the signal indicating the radio field intensity E _S and the periodic signal output from the oscillator to generate a step track signal. The oscillator may be built in the step track controller 84-1. Elevation axis step track signal antenna 14 Y _A -Y _A and azimuthal axis Z-Z around the predetermined angle amplitude ± .delta..theta, ± elevation axis a periodic signal and an antenna 14 for periodically rotating at .delta..phi Y _A rotation angle signal [Delta] S _Y for radio field intensity E _S rotates in the direction of increasing the -Y _a and azimuthal axis Z-Z around and a [Delta] S _Z.

Such a step track rotation angle signal Δ
S _Y and ΔS _Z are supplied to the adder 71 of the elevation axis stabilization loop and the adder 72 of the azimuth axis stabilization loop, respectively, and output signals ω _YA and ω _{ZA of} the second and third gyros 57 and 58.
Is added to.

Therefore, the signal supplied from the adder 71 to the integrator 37 is the output signal ω _YA of the second gyro 57 to which the step track rotation angle signal ΔS _Y is added. The signal supplied to the converter 83 is the output signal ω _ZA of the third gyro 58 to which the step track rotation angle signal ΔS _Z is added.

For the sake of simplicity, it is assumed that the navigation body has no sway, and the satellite altitude angle θ _S = 0. The output signal θ of the elevation transmitter 34 is zero. In this case, step tracking rotational angle signal [Delta] S _Y, elevation axis of the [Delta] S _Z Y _A -
Y step tracking the rotation angle [Delta] S _Y around _A is zero, the antenna 14 is the rotation angle [Delta] S _Z to azimuthal axis Z-Z around
Just rotate.

However, normally the satellite altitude angle θ_S> 0
And the output signal θ of the elevation transmitter 34 is not zero. Servant
The angular velocity component obtained by the coordinate converter 83
ω_X, Ω _Y, Ω_ZStep track rotation angle signal ΔS
_Y, ΔS_ZAre superimposed.

[0107] When the elevation axis Y _A -Y _A is not horizontal, even operate step tracking control in the horizontal axis control loop. Thus, according to this example, the horizontal axis X-
X, step track control the elevation axis Y _A -Y _A and azimuthal axis Z-Z around is performed, when the radio field intensity E _S is maximized, the rotation movement of the antenna 14 by the step track control is stopped.

Next, the gyro drift correction function will be described. As described above, in the antenna directing device of this example, in addition to the three-axis control by the three control loops,
Step track type control is provided in an overlapping manner. The step track type control is provided to complement the three-axis control or to correct the error generated by the three control loops.

[0109] For simplicity here, the control function of the horizontal axis control loop, the elevation axis Y _A -Y _A is assumed to be arranged horizontally. Therefore, consider two control loops, an elevation axis control loop and an azimuth axis control loop.
Antenna 14 by two-axis control by two control loops
If is correctly pointed to the satellite, the step-track control will not work. Therefore, the rotation angle signal ΔS generated by the step track controller 84-1
_Z and ΔS _Y represent pointing errors generated by the two control loops.

Such pointing error includes an error caused by drift of each gyro and an actual satellite altitude angle θ when the satellite moves.
Errors due to changes in _S and satellite azimuth φ _S are included. The gyro drift correction function is provided to correct the error caused by the gyro drift and the error caused by the movement of the satellite.

The gyro drift correction function of this example corrects the error caused by the gyro drift in the elevation angle control loop and the azimuth axis control loop. According to the gyro drift correction function of this example, the rotation angle signals ΔS _Z and ΔS _Y generated by the step track controller are used to correct the error caused by the gyro drift. Gyro drift correction signals Δω _Z and Δω _Y are generated from the rotation angle signals ΔS _Z and ΔS _Y , whereby drifts of the second gyro 57 of the elevation axis control loop and the third gyro 58 of the azimuth axis control loop are generated. Will be corrected.

Step track controller as shown in FIG.
84-1 The rotation angle signal ΔS generated by_Z, ΔS_Y
Is integrated by integrators 84-2 and 84-3,
Smoothed by smoothing circuits 84-4 and 84-5,
Lo-drift correction signal Δω_Z, Δω_YIs generated. Ja
Irodrift correction signal Δω_Z, Δω_YHold device 84
It is output via -6 and 84-7. Hold device 84
-6 and 84-7 are from the step track controller 84-1
When the hold signal H supplied is input, the smoothing circuit 84
-4, 84-5 Gyro drift correction signal supplied from
Issue Δω_Z, Δω _YHold and output it.

[0113] The navigation body navigates in a tunnel or near a building.
Then, the radio wave is interrupted and the radio field intensity signal E_SI can not get
Rotation angle signal ΔS_Z, ΔS_YIs not generated. Such
If the gyro drift correction signal Δω_Z, Δω_YGot
Error due to drift increases during that time.
The Rukoto. According to this example, in such a case, the hold device
Gyro drift held in 84-6, 84-7
Correction signal Δω_Z, Δω _YIs output as an estimated value. E
The field signal H is, for example, the radio field intensity E._SIs below a certain value
May occur when an error occurs.

Gyro drift correction signals Δω _Z , Δω _Y
Are supplied to the adder 71 of the elevation axis stabilization loop and the adder 72 of the azimuth axis stabilization loop, respectively, whereby the output signals ω _YA and ω _{ZA of} the second and third gyros are respectively corrected. Therefore, from the adders 71 and 72 to the integrator 37
And the signals supplied to the coordinate converter 83 are the second
And output signals ω _YA and ω _ZA of the third gyros 57 and 58, and gyro drift correction signals Δω _Y and Δω _Z are added.

Next, the above-mentioned gyro drift correction will be described with reference to FIG. FIG. 4 is a block diagram of the azimuth axis control loop. The gyro drift correction in the azimuth axis control loop will be described below, but the same applies to the gyro drift correction in the elevation axis control loop.

For simplicity, the position of the satellite is unchanged,
Accurate values are obtained for the satellite altitude angle θ _S and the satellite azimuth angle φ _S. In addition, it is assumed that there is no shaking of the navigation body,
The satellite altitude angle θ _S is assumed to be zero. Elevator transmitter 3
The output θ of 4 is zero. In the third expression of the expression (8), θ
Substituting = 0, we obtain ω _Z = ω _ZA . That is, the output ω _Z of the coordinate converter 83 is equal to the output ω _ZA of the third gyro 58. Therefore, in FIG. 4, the coordinate converter 83 is removed.

As shown in the figure, in the azimuth axis constraint loop, the gain of the azimuth axis control amplifier 46 is -k, the gain of the azimuth axis control integrator 47 is 1 / S, the gain of the attenuator 48 is K _T ,
The gain of the azimuth oscillator 44 is 1 / S, the gain of the azimuth gear 42 and the azimuth servomotor 43 is 1, and the drift of the third gyro 58 is U _Z. In the gyro drift calculator 84, the gain of the integrator 84-2 is set to 1 / (T
_ST S), and 1 the gain of the smoother 84-4 and hold circuit 84-6.

The adder 72 receives the third error including the drift error U _Z.
The output ω _Z = ω _ZA of the gyro 58 and the outputs Δω _Z and ΔS _{Z of the} gyro drift calculator 84 are added. Adder 4
7-1 adds the output of the attenuator 48 and the output of the adder 72. This adder 47-1 is included in the integrator 47 in FIG. The adder 49 subtracts the satellite azimuth angle φ _S from the sum of the azimuth angle φ output from the azimuth transmitter 44 and the bow azimuth angle φ _C.

As described above, the step track rotation angle signal is received.
Issue ΔS_ZIs the azimuth angle φ of the antenna 14. _AIs the satellite azimuth φ_S
Step track controller 84-
1 may be generated. Azimuth angle φ of antenna 14_AGae
Star azimuth φ_SIf it is more offset, the antenna 14 will receive
Radio wave strength E_SDecreases. So, for example,
Radio field strength E_SIs less than the specified value
Step track rotation angle signal ΔS_ZIs generated
You can be.

The step track rotation angle signal ΔS _Z of the azimuth axis control system is assumed as follows.

[0121]

[Formula 9] ΔS _Z = K _ST (φ + φ _C −φ _S ) = K _ST (φ _A −φ _S ) = K _ST (φ + Δφ _C )

K_STIs a constant of proportionality. φ is the azimuth transmitter 4
Output of 4, φ_CIs the azimuth angle of the bow, φ_SIs the satellite azimuth angle, φ_A
(= Φ + φ_C) Is the azimuth angle of the antenna 14. Also,
Δφ _C= Φ_C-Φ_SIs.

When the azimuth angle φ is calculated from the equation (9), it becomes as follows.

[0124]

[Equation 10]

However, a = T _ST / K _ST and b = K _T / K _ST . When the output Δω _Z of the integrator 84-2 is calculated,

[0126]

[Equation 11]

Here, φ _C = φ _C '/ S, φ _S = φ _S '
Substituting / S, U _Z = U _Z '/ S to calculate the final value,

[0128]

[Formula 12] Δω _Z = −U _Z 'φ = φ _S ' −φ _C '

In this way, the fixed error of the third gyro 58 (the error caused by the gyro drift) is compensated by the integrator 84-2 of the gyro drift calculating section 84.
Therefore, the azimuth angle φ _A (= φ + φ _C ) of the antenna 14 becomes equal to the set satellite azimuth angle φ _S.

By the way, as described above, the pointing error of the antenna 14 includes the error caused by the drift of the gyro and the error caused by the change of the absolute position of the satellite.
Here, the error caused by the change in the absolute position of the satellite is considered. Usually, the satellite is a geostationary satellite, and as the satellite azimuth angle φ _S and the satellite altitude angle θ _S , constant values obtained by observation with a moving body are used. The set satellite azimuth angle φ _S and the satellite altitude angle θ _S are set manually, for example.

Therefore, when the absolute position of the satellite changes, a deviation occurs between the actual satellite azimuth angle φ _SR and satellite altitude angle θ _SR and the set satellite azimuth angle φ _S and satellite altitude angle θ _S.
This causes a pointing error of the antenna 14.

The pointing error of the antenna 14 includes an error caused by a change in the actual satellite azimuth angle φ _SR and an actual satellite altitude angle θ _SR.
Although there is an error due to the change of, here again, for simplification, only the error due to the change of the satellite azimuth φ _SR will be considered. Let Δφ _SR be the actual change in satellite azimuth angle φ _SR . Δ
When φ _SR is the amount of change in the actual satellite azimuth angle φ _SR , φ _S is the set satellite azimuth angle, and φ _SR is the actual satellite azimuth angle, the following equation holds.

[0133]

[Equation 13] Δφ _SR = φ _SR −φ _S φ _SR = φ _S + Δφ _SR

The set satellite azimuth angle supplied to the adder 49 is φ _S. In the control by the azimuth axis control loop, since the set satellite azimuth angle φ _S is used, the actual satellite azimuth angle φ
_{Although the} pointing error occurs when _SR changes, the actual satellite azimuth angle φ _SR changes because the step track control uses the radio wave intensity E _S and does not use φ _S as the set satellite azimuth angle. Even if there is no pointing error.

Therefore, it is considered that the satellite azimuth angle φ _S included in the step track rotation angle signal ΔS _Z obtained by the step track control expressed by the equation (9) represents the actual satellite azimuth angle φ _SR. To be Therefore, φ _S in the equation (9) is replaced by φ _{SR in} the equation (13).

[0136]

[Expression 14] ΔS _Z = K _ST (φ + φ _C −φ _S −Δφ _SR )

The equation (14) is used to solve for φ and Δω _Z.

[0138]

[Equation 15]

However, a = T _ST / K _ST and b = K _T / K _ST . When the output Δω _Z of the integrator 84-2 is calculated,

[0140]

[Equation 16]

Here, φ _C = φ _C '/ S, φ _S = φ _S '
Substituting / S, Δφ _SR = Δφ _SR '/ S, U _Z = U _Z ' / S to calculate the final value,

[0142]

[Expression 17] Δω _Z = -U _Z '-K _T Δφ _SR ' φ = φ _S '+ Δφ _SR ' -φ _C '

As is clear from the second equation of the equation (17),
The azimuth angle φ _A (= φ + φ _C ) of the antenna 14 is φ _S '+ Δ
φ _SR ', which is equal to the actual azimuth angle φ _S + Δφ _SR of the satellite after the satellite position changes. That is, the antenna 14
The central axis X _A -X _A of the arrow points in the actual satellite direction.

As is clear from the first equation of the equation (17),
The drift correction value Δω _Z is the original gyro drift U _Z '
The second term K _T Δφ _SR 'is added to. K _T Δ
φ _SR 'can be considered as a correction value due to the change in the satellite position. If this is divided by the gain K _T of the attenuator 48, the amount of change in satellite azimuth angle Δφ _SR 'is obtained. Therefore, the first expression of the expression (17) is the adder 49
At, indicates that satellite azimuth angle φ _S + Δφ _SR corrected in place of the satellite azimuth angle phi _S 'is equivalent to that supplied.

As described above, according to this example, the drift correction value Δω _Z generated by the gyro drift calculating section 84.
Has a function of correcting an error caused by the original gyro drift and a function of correcting an error caused by a change in the position of the satellite.

When radio waves cannot be received, the drift correction value Δω _Z output from the gyro drift calculator 84 is a fixed value held by the hold device 84-6. Also in such a case, the azimuth angle φ is represented by the equation (17). Therefore, the central axis X of the antenna 14
_A- X _A points in the actual satellite direction.

Normally, the period during which radio waves cannot be received is short, and during that period, it can be considered that the gyro drift is constant. But the gyro drift U _Z changed,
Assuming that U _Z + ΔU _Z , the azimuth angle φ is

[0148]

[Number 18] _{φ = φ S '+ Δφ SR} ' -φ C '-ΔU Z' / K T

Therefore, assuming that the gyro drift U _Z is constant, an error will occur by the fourth term ΔU _Z ′ / K _{T of} this equation. However, the attenuator 48
It is also possible to suppress the occurrence of error by adding an integration function to.

According to this example, a step track control for complementing the azimuth axis control loop is provided, but consider a case where the azimuth axis constraint loop is removed.
When the electric wave cannot be received and the step track control cannot be performed, the equation of Formula 18 is differentiated,

[0151]

## EQU19 ## dφ / dt = -ΔU _Z '

The antenna 14 rotates around the azimuth axis ZZ at an angular velocity corresponding to the amount of change in drift.
Next, when the radio wave is received and the step track control is started, the antenna 14 is largely deviated from the satellite direction. According to the present invention, such a phenomenon does not occur because the step track control is superimposed on the azimuth axis restraint loop and the azimuth axis stabilization loop.

Next, the function and configuration of the antenna elevation angle calculation unit 81 will be described. The antenna elevation angle calculator 81 in this example may be the same as that described with reference to FIG.

Next, the function and structure of the elevation axis tilt calculating section 82 will be described. Rotation angle ψ of the antenna 14 of the elevation axis tilt calculator 82 around the horizontal axis X-X, i.e., is configured to determine the tilt angle ψ of the elevation axis Y _A -Y _A relative to the horizontal plane. Elevation axis tilt calculator 82 inputs the 'sine sinψ about' inclination angle ψ of the elevation axis Y _A -Y _A relative to a horizontal plane that is output by the second accelerometer 67, the inclination angle ψ by calculating the arctangent Output a signal that represents'.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-mentioned embodiments, and it will be understood by those skilled in the art that various other configurations can be adopted without departing from the gist of the present invention. Easy to understand.

[0156]

According to the present invention, three gyros 56,
57,58 and three accelerometers 66,67,68,
In an antenna directing device configured to direct the antenna 14 in the satellite direction by a three-axis control loop including a horizontal axis control loop, an elevation angle control loop, and an azimuth axis control loop, a gyro signal of an antenna coordinate system is transmitted to each servo motor 2.
A coordinate converter 83 for converting into command signals to 3, 33, 43 is provided, whereby gyro signals from the three gyros 56, 57, 58 mounted on the antenna 14 are transmitted to the servo motors 23, Since it is converted into the command signals to 33 and 43, there is an advantage that the antenna 14 can be rotationally controlled around the three axes to accurately orient the antenna 14 in the satellite direction.

According to the present invention, the gyro drift calculator 84 is provided in the antenna directing device in which the step track type control system is provided so as to be superposed on the three-axis control loop, and such a gyro drift calculator is provided. Since 84 uses the step track control to simultaneously correct both the error caused by the gyro drift and the error caused by the movement of the satellite, there is an advantage that the antenna 14 can be accurately pointed toward the satellite.

According to the present invention, in an antenna directing device provided with a step track type control system superimposed on a three-axis control loop, both an error caused by a gyro drift and an error caused by a satellite movement are caused. A gyro drift calculator 84 for correcting the gyro drift is provided, and the gyro signals output from the three gyros 56, 57, 58 are corrected by the gyro drift calculator 84.
4 has the advantage that it can be accurately oriented in the satellite direction.

According to the present invention, the navigation body is
When navigating near buildings, the radio wave is interrupted and the radio field strength signal E
_SEven when the
Is held by the holding devices 84-6 and 84-7 of
Gyro drift correction value ω _Z, Ω_YIs output and it
Output from three gyros 56, 57, 58
Since the gyro signal is corrected, the antenna 14
Has the advantage that it can be pointed in the direction of the satellite.

According to the present invention, in an antenna directing device in which a step-track type control system is provided so as to be superimposed on a three-axis control loop, each control loop has a restraint system and a stabilizing system. The control loop is always operating, and the antenna 14 can be accurately directed toward the satellite even when the radio field intensity signal E _S is not obtained and the step track control does not operate and the drift of the gyro changes during that time. There are advantages.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of an antenna pointing device of the present invention.

FIG. 2 is an explanatory diagram illustrating an operation of a coordinate converter.

FIG. 3 is a diagram showing a configuration of a gyro drift calculator.

FIG. 4 is a block diagram of a part of a control system of the antenna directing device of the present invention.

FIG. 5 is a diagram showing an example of a conventional antenna directing device.

FIG. 6 is an explanatory diagram illustrating an operation of an antenna elevation angle calculator.

[Explanation of symbols]

3 Base stand 3-1 Bridge part 13 Arm 14 Antenna 20 Horizontal axis 21 Horizontal gimbal 22 Horizontal gear 23 Horizontal servo motor 23-1 Pinion 26 Amplifier 27 Integrator 28 Attenuator 29 Adder 30, 30-1, 30-2 Elevation angle Axis 31 Mounting bracket, Elevation gimbal 31-1, 31-2 Leg 32 Elevation gear 33 Elevation servo motor 33-1 Pinion 34 Elevation transmitter 36 Amplifier 37 Integrator 38 Attenuator 39 Adder 40 Azimuth 40A, 40B Bearing 41 Azimuth gimbal 41-1 Support shaft part 41-2 U-shaped part 42 Azimuth gear 43 Azimuth servomotor 44 Azimuth oscillator 46 Amplifier 47 Integrator 48 Attenuator 49 Adder 56 First gyro 57 Second gyro 58 Third Gyro 66 1st accelerometer 67 2nd accelerometer 68 3rd acceleration Total 71,72 adder 81 antenna elevation angle calculating unit 82 elevation axis inclined calculating unit 83 coordinate converter 84 gyro drift calculator X-X horizontal axis Y _A -Y _A elevation axis Z-Z orientation axis X _A -X _A antenna center axis perpendicular to both the axis Z _a -Z _a antenna center axis and elevation axis

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasuo Tsukoshi 2-16-46 Minami Kamata, Ota-ku, Tokyo Within Tokimec Co., Ltd. (72) Inventor Koichi Umeno 2-16-46 Minami Kamata, Ota-ku, Tokyo In stock company Tokimec (72) Inventor Yoshinori Kamiya 2-16-46 Minami Kamata, Ota-ku, Tokyo In stock company Tokimec (72) Inventor Kazuya Arai 2-16-46 Minami Kamata, Ota-ku, Tokyo Tokimec Co., Ltd. Within

Claims (4)

[Claims] 1. An antenna having a central axis, three axes of an elevation axis orthogonal to the central axis of the antenna, a horizontal axis and an azimuth axis orthogonal to the horizontal axis, and the antenna having the three axes around the three axes. A rotatably supporting device, a first gyro having an input axis parallel to the central axis, a second gyro having an input axis parallel to the elevation axis, and the central axis and the elevation axis. A third gyro having an input axis orthogonal to the two, an elevation transmitter that outputs a signal that indicates a rotation angle of the antenna around the elevation axis with respect to the navigation body, and the antenna is rotationally controlled around the horizontal axis. It includes a horizontal axis control loop, an elevation axis control loop for controlling rotation of the antenna about the elevation axis, and an azimuth axis control loop for controlling rotation of the antenna about the azimuth axis. A control device for directing the central axis of the antenna in the direction of the satellite, and the antenna directing device configured to be mounted on a navigation body, wherein the antenna output from the first gyro Rotational angular velocity about a central axis, rotational angular velocity about an axis orthogonal to both the central axis and the elevation axis of the antenna output from the third gyro, and the elevation angle of the antenna output from the elevation transmitter. From the rotation angle around the axis, the required rotation angular velocity of the antenna around the horizontal axis for supplying to the horizontal axis control loop and the required rotation angular velocity around the azimuth axis for supplying to the azimuth axis control loop are calculated. An antenna directing device, which is provided with a coordinate converter for performing. 2. The antenna pointing device according to claim 1, wherein a step track control unit for generating a step track signal for pointing the antenna in a satellite direction by a step track method and a gyro drift of the three gyros are corrected. And a gyro drift calculation section having a gyro drift correction section for correcting the output signal of the second gyro by inputting a radio field intensity signal indicating the radio field intensity received by the antenna. And a step track signal that corrects the output signal of the third gyro, and the gyro drift correction section inputs the step track signal and corrects the output signal of the second gyro. Correct the correction signal and the output signal of the third gyro. Antenna pointing apparatus characterized by being configured to generate a drift correction signal. 3. The antenna directing device according to claim 1, wherein the gyro drift correction section has a hold unit for holding the drift correction signal, and the hold unit is provided when the radio field intensity signal is cut off. An antenna pointing device configured to output the drift correction signal stored in a container. 4. The antenna directing device according to claim 1, 2 or 3, wherein a first accelerometer for detecting an inclination angle of the central axis with respect to a horizontal plane and a second accelerometer for detecting an inclination angle of the elevation axis with respect to a horizontal plane. For calculating the elevation angle of the antenna from the output signals of the three accelerometers, the third accelerometer for detecting the inclination angle of the axis orthogonal to both the center axis and the elevation axis with respect to the horizontal plane. An antenna elevation angle calculation section is provided, and the antenna elevation angle signal obtained by the antenna elevation angle calculation section is configured to be supplied to the elevation angle axis control loop.