JPH07154128A - Antenna directing device - Google Patents

Abstract

PURPOSE:To direct an antenna to a satellite in an excellent way by providing a shake angle arithmetic section, a servo deviation correction arithmetic section and an adder in the device and correcting a detection angular velocity deviation caused in an output of a gyro based on a tracking difference around an azimuth axial line and an elevating axial line. CONSTITUTION:A servo deviation correction arithmetic section 120 receives a shake angle or the like calculated by a shake angle arithmetic section 94 to calculate deviations he, ha of a detection angle of an elevating angle gyro 44 and an azimuth gyro 45. The deviations (he), (ha) are fed respectively to adders 125, 126, an angular velocity outputted from the gyro 44 is corrected by the deviation (he) at the adder 125, and an angular velocity outputted from the gyro 45 is corrected by the deviation (ha) at the adder 126. An corrected output signal of the gyros 44, 45 is fed respectively to an elevating angle control integration device 54 and an azimuth angle control integration device 58. An instruction signal outputted from the integration devices 54, 58 is fed to servo motors 33, 23 respectively via amplifiers 55, 59. Thus, the antenna 14 is directed in the direction of a satellite in an excellent way.

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 pointing device is basically referred to as an azimuth-elevation system, and has a base 3 and an azimuth gimbal 40 attached to the base 3, and a mounting bracket attached to a U-shaped member at the upper end of the azimuth gimbal 40. 41 and the antenna 14 attached to such a mounting bracket 41.

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 21-1 and 21-2 is mounted inside the cylindrical portion 11. The azimuth axis 20 is fitted to the inner rings of the bearings 21-1 and 21-2, and the azimuth gimbal 40 is attached to the upper end of the azimuth axis 20 via the arm 13.

Thus, the azimuth axis 20 has the bearings 21-1, 21.
The azimuth gimbal 40 can rotate about an axis passing through the azimuth axis 20 while being supported by -2. The azimuth gimbal 40 has a lower support shaft portion 40-1 and an upper U-shaped portion 40-2, and the central axis of the support shaft portion 40-1, that is, the azimuth axis ZZ is as shown in the figure. It is arranged deviated from the axis passing through. The support shaft portion 40-1 may be configured to be aligned with the axis line passing through the azimuth axis 20.

On the U-shaped portion 40-2 of the orientation gimbal 40, a smaller U-shaped mounting member 41 is arranged, and the mounting member 41 has two legs 41-
The elevation angle axes 30-1 and 30-2 are provided on the respective 1 and 41-2. A suitable bearing is mounted on each of the two legs of the U-shaped portion 40-2 of the orientation gimbal 40, 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 YY, and thus the mounting bracket 41 is located between the two legs of the U-shaped portion 40-2 of the orientation gimbal 40. Is rotatably supported around the elevation axis Y-Y. The elevation axis Y-Y is arranged at right angles to the azimuth axis Z-Z.

The azimuth axis ZZ is perpendicular to the mounting surface of the antenna directing device, for example the hull surface, so that the elevation axis YY is always arranged parallel to the hull surface.

The leg portion 41 of the U-shaped mounting bracket 41
The antenna 14 is attached to the antennas 1 and 41-2.
It can rotate around Y. The antenna 14 has a central axis XX, which is the elevation axis Y-.
It is perpendicular to Y.

The mounting bracket 41 includes an elevation gyro 44.
And the azimuth gyro 45 are attached, and the rotation angular velocity of the antenna 14 rotating around the elevation axis YY is detected by the elevation gyro 44, and both the elevation axis YY and the center axis XX of the antenna 14 are detected by the azimuth gyro 45. The angular velocity of rotation of the antenna 14 around the axis orthogonal to is detected. The elevation gyro 44 and the azimuth gyro 45 may be, for example, an integral 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.

A first accelerometer 46, a second accelerometer 47, and a third accelerometer 48 are further mounted on the mounting bracket 41. The first accelerometer 46 detects the inclination angle of the central axis XX of the antenna 14 around the elevation axis YY, and the second accelerometer 47 detects the inclination angle x of the elevation axis YY with respect to the horizontal plane. It

If the second accelerometer 47 is mounted on the mounting bracket 41 so that its input axis is parallel to the elevation axis YY, its output is proportional to sinx. The second accelerometer 47 may be attached to the azimuth gimbal 40 so that its input axis is parallel to the elevation axis YY.

The third accelerometer 48 is the first accelerometer 46.
And the second accelerometer 47 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 46 and the input axis line of the second accelerometer 47. It is attached. Thus, the third accelerometer 48 has the central axis XX and the elevation axis Y- of the antenna 14.
The tilt angle of the axis line orthogonal to both Y with respect to the horizontal plane is detected.

An elevation gear 32 is mounted on one leg of the mounting bracket 41 coaxially with the elevation axis Y--Y. A pinion 35 is meshed with the elevation gear 32, and the pinion 35 is mounted on one leg of the U-shaped portion 40-2 of the azimuth gimbal 40.
It is attached to the rotating shaft of 3.

An elevation transmitter 34 is attached to one leg of the U-shaped portion 40-2 of the azimuth gimbal 40, and the elevation transmitter 34 mounts the elevation axis Y--Y of the antenna 14.
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 2 is provided at the lower end of the azimuth axis 20.
2 is attached, and the azimuth servo motor 23 and the azimuth transmitter 24 are attached on the bridge portion 3-1 of the base 3.
Pinions (not shown) attached to the rotating shafts of the azimuth servo motor 23 and the azimuth transmitter 24 are configured to mesh with the azimuth gear 22.

As shown, an elevation control loop and an azimuth control loop are provided to control the antenna pointing device. The angle formed by the central axis line XX of the antenna 14 with the horizontal plane is the elevation angle θ _A of the antenna, and the angle formed by the central axis line XX of the antenna 14 with the meridian line N on the horizontal plane is the azimuth angle φ _{A of the} antenna.

The elevation control loop is configured to rotate the antenna 14 about the elevation axis Y--Y so that the elevation angle θ _A of the antenna matches the satellite elevation angle θ _S , a fast control loop, namely elevation stabilization. A loop and a slow control loop, ie an elevation constraint loop. Fast control loop, ie
In the elevation stabilization loop, the output of the elevation gyro 44 is fed back to the elevation servomotor 33 via the elevation control integrator 54 and the amplifier 55. As a result, even if the hull oscillates, the angular velocity about the elevation axis YY of the antenna 14 with respect to the inertial space is always maintained at zero.

In the slow control loop, that is, the elevation angle restraint loop, the output signal of the orthogonal three-axis accelerometer consisting of the first accelerometer 46, the second accelerometer 47 and the third accelerometer 48 is the antenna elevation angle calculator. 81. The antenna elevation angle calculation unit 81 inputs the output signals g ₁ , g ₂ , g ₃ of the _three accelerometers 46, 47, 48, and outputs the elevation angle θ _A of the antenna 14, that is, the central axis X of the antenna 14 with respect to the horizontal plane.
Calculate the inclination angle θ _{A of} −X. Such an operation is executed based on the following equation (1).

[0019]

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

As is clear from the equation (1), such calculation includes 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. . For details of the function and configuration of the antenna elevation angle calculation unit 81, Japanese Patent Application No. 4-3487 filed by the same applicant as the applicant of the present application.
See No. 45.

The signal indicating the elevation angle θ _A of the antenna 14 output from the antenna elevation angle calculation unit 81 is reduced by, for example, the signal indicating the manually set satellite altitude angle θ _S , and further passed through the attenuator 56. Then, it is input to the elevation angle control integrator 54 and the amplifier 55. This loop is antenna 1
It has an appropriate time constant for matching the elevation angle θ _A of 4 with the satellite altitude angle θ _S. The attenuator 56 is attached to the elevation gyro 44.
It is also possible to provide an integral characteristic in order to compensate the drift fluctuation of the.

The azimuth control loop controls the azimuth gimbal 4 so that the azimuth φ _A of the antenna 14 matches the satellite azimuth φ _S.
It is configured to control zero azimuth and includes a fast control loop, an azimuth stabilization loop and a slow control loop, an azimuth constraint loop. In the fast control loop, that is, the azimuth stabilization loop, the output signal of the azimuth gyro 45 is the secθ calculation unit 76 and the azimuth control integrator 5.
8 and the feedback to the azimuth servomotor 23 via the amplifier 59, which causes the antenna 14 to respond to the rotational movement of the hull about an axis orthogonal to both the central axis XX and the elevation axis YY of the antenna 14. Can be stabilized.

Slow control loop, ie azimuth constraint loop
Rotate the bearing gimbal 40 from the bearing transmitter 24 at
Outputs a rotation angle signal that indicates the angle (rotation angle of the antenna) φ
The rotation angle signal is supplied to the adder 61. Addition
In the calculator 61, the rotation angle φ and the magnetic compass or
Is the heading azimuth φ supplied by the gyro compass_CAnd inclination
Inclination correction value Δφ supplied from the inclination correction calculation unit 93_AAnd
Satellite azimuth φ from the sum_SIs subtracted. Addition
The output signal of the calculator 61 is further passed through the attenuator 60.
It is input to the position angle control integrator 58. Antenna rotation angle φ
And bow azimuth φ _CAnd tilt correction value Δφ_AIs the satellite direction
Angle φ_SThe direction of the antenna 14 is stationary when
It

The tilt correction calculation unit 93 is used for the elevation transmitter 3.
4 outputs a signal indicating the rotation angle θ of the antenna 14 about the elevation axis YY and a sine value sinx of the inclination angle x of the elevation axis YY with respect to the horizontal plane output from the second accelerometer 47. Signal and the central axis line XX and the elevation axis line YY of the antenna output from the third accelerometer 48.
Enter a signal indicating the sine value sin [theta _P inclination angle theta _P with respect to the horizontal plane of the axis perpendicular to both of, it calculates a tilt correction value [Delta] [phi _A.

The tilt correction value Δφ _A is obtained by the following equation (2).

[0026]

(2) tan Δφ _A = sin θ · sinx / sin θ _P

For the details of the construction and operation of the inclination correction calculation unit 93, refer to Japanese Patent Application No. 5-2581 filed by the same applicant as the present applicant.

The azimuth control loop has an appropriate time constant for matching the azimuth angle φ _A of the antenna 14 with the satellite azimuth angle φ _S. Incidentally, the attenuator 60 may be provided with an integral characteristic in order to compensate for the drift fluctuation of the azimuth gyro 45. That is, the outputs of the attenuators 56 and 60 correspond to the output of the integral gyro torquer.

In this way, the antenna 14 is constructed so that its central axis XX is directed toward the satellite by the elevation angle control loop and the azimuth angle control loop.

[0030]

In the antenna directing device, the center axis XX of the antenna may be parallel to the azimuth axis ZZ when the hull is shaken.
In such a case, in the conventional antenna directing device, the output of the secθ computing unit 76 in the third loop of the azimuth control loop becomes an extremely large value, and as a result, the central axis line XX of the antenna 14 should normally be directed. There was a drawback that it was offset from the direction of the satellite.

The problem will be described below. The control loop operates when the hull rotates (tilts) around the roll axis (the bow direction) at the roll angle β due to the roll motion and the central axis XX of the antenna deviates from the satellite direction. As a result, it is assumed that the antenna 14 rotates by the rotation angle φ around the azimuth axis ZZ and rotates by the rotation angle θ around the elevation axis YY so that the central axis XX of the antenna points in the satellite direction. To do.

At this time, the angular velocities ω _Y and ω _Z detected by the elevation angle gyro 44 and the azimuth gyro 45 are respectively expressed as follows.

[0033]

[Number 3] _{ω Y = -β 1 sinφ + θ} 1 ω Z = β 1 cosφ · sinθ + φ 1 cosθ

Β ₁ : Rotational (tilt) speed of the hull about the roll axis θ: Rotational angle of the antenna 14 around the elevation axis θ ₁ : Rotational speed of the antenna 14 around the elevation axis (= dθ
/ Dt) φ: rotation angle of the antenna 14 around the azimuth axis φ ₁ : rotation speed of the antenna 14 around the azimuth axis (= dφ
/ Dt)

In the fast control loop, that is, the azimuth stabilization loop, the output of the secθ calculation unit 76 becomes zero,
It functions to control the orientation of the orientation gimbal 40. s
When the output of the ecθ calculation unit 76 is zero, the angular velocity ω _Z represented by the equation 3 becomes zero (ω _Z = 0). Therefore, the following equation holds.

[0036]

[Equation 4] φ ₁ = −β ₁ cos φ · tan θ

Angular velocity φ ₁ represented by the equation (4)
Is the rotational speed φ ₁ about the azimuth axis ZZ of the antenna 14 (or the azimuth gimbal 40) to be achieved by the azimuth stabilization loop. Such a rotational speed φ ₁ is achieved by the azimuth servomotor 23, so this is the command signal supplied to the azimuth servomotor 23.

As is apparent from the equation (4), the command signal φ ₁ supplied to the azimuth servomotor 23 has a maximum value when the rotation angle θ of the antenna 14 around the elevation axis YY is close to 90 °. Become. For example, β ₁ = 20 ° / s, φ = 0
When θ and θ = 89 °, φ ₁ = 1146 ° / s.

Azimuth servomotor 2 actually used
3 does not have the ability to achieve such a large rotation speed φ ₁ . Therefore, even if the azimuth control loop operates, the central axis line XX of the antenna 14 cannot follow the satellite azimuth, and the output of the secθ calculation unit 76 does not become zero. The output of the secθ calculation unit 76 is input to the second integrator, that is, the elevation angle control integrator 58, as the azimuth servo deviation.

In the elevation stabilization loop which is a fast control loop, the angular velocity ω _Y represented by the equation (3) is zero (ω _Y
Functioning to control the elevation angle of the antenna 14 such that Therefore, the following equation holds.

[0041]

[Equation 5] θ ₁ = β ₁ sin φ

The angular velocity θ ₁ expressed by the equation (5)
Is the rotational speed θ ₁ about the elevation axis YY of the antenna 14 to be achieved by the first loop of the elevation control system. Such rotational speed θ ₁ is achieved by the elevation servomotor 23, and thus this is the command signal supplied to the elevation servomotor 33.

As is clear from the equation (5), the elevation servo
Command signal θ supplied to the motor 23 ₁The maximum value of
Rotation (tilt) speed around the roll axis β₁Degree, abbreviation
It is about 20 ° / s.

However, as is clear from the equation (5), such a command signal, that is, the rotational angular velocity θ ₁ includes the azimuth angle φ. As described above, the antenna 14 around the elevation axis YY
When the rotation angle θ of is close to 90 °, the rotation angle φ of the antenna 14 around the azimuth axis ZZ includes the azimuth servo deviation. Therefore, as represented by the equation (5), the command signal θ ₁ supplied to the elevation servomotor 33 also has a value biased by the azimuth servo deviation.

In this way, the elevation angle stabilizing loop causes the elevation angle servomotor 33 to output the command signal θ including the tracking error.
The central axis X of the antenna 14 is controlled by ₁
-X is deviated from the satellite elevation angle θ _S.

Similarly, as is clear from the equation (4), the command signal φ ₁ supplied to the azimuth servomotor 23 is the rotation angle φ of the antenna 14 around the azimuth axis ZZ and the elevation axis Y-.
It is a function of both the rotation angle θ of the antenna 14 around Y, and these two angles are affected by the azimuth servo deviation and the elevation servo deviation, respectively, as described above. In this way, the azimuth stabilization loop causes the azimuth servomotor 23 to operate.
Is controlled by a command signal φ ₁ including a tracking error, the center axis X-X of the antenna 14 has a satellite orientation φ.
It will be biased from _S.

Thus, in the conventional antenna directing device, when the rotation angle θ of the antenna 14 around the elevation axis YY approaches 90 °, an azimuth servo deviation occurs in the azimuth control loop, which also affects the elevation angle control loop. give. As a result, the central axis XX of the antenna 14 is deviated from the satellite direction.

In view of the above point, the present invention makes the antenna 14 a satellite even when the hull is shaken during navigation and the rotation angle θ of the antenna 14 around the elevation axis YY is close to 90 °. An object of the present invention is to provide an antenna directing device that can favorably direct to the antenna.

[0049]

According to the present invention, a support member 41 having a central axis XX, as shown in FIG.
The azimuth gimbal 40 that rotatably supports the antenna 14 supported on the antenna 14 and the supporting member 41 around the elevation axis YY orthogonal to the central axis XX, and the azimuth gimbal 40 on the elevation axis YY. A base 3 rotatably supporting the azimuth axis ZZ orthogonal to each other, a first gyro 44 having an input axis parallel to the elevation axis Y-Y and fixed to the support member 41, and a central axis X-. A second fixed to the support member 41 having an input axis orthogonal to both X and the elevation axis Y-Y.
Gyro 45, and a first accelerometer 46 that outputs a signal indicating the tilt angle of the central axis line XX with respect to the horizontal plane,
A second accelerometer 47 that outputs a signal that indicates the tilt angle of the elevation axis YY with respect to the horizontal plane, and a third accelerometer 47 that has an input axis orthogonal to both the center axis XX of the antenna and the elevation axis YY. The accelerometer 48, the azimuth oscillator 24 that outputs a signal indicating the rotation angle of the azimuth gimbal 40 about the azimuth axis ZZ, and the elevation axis YY with respect to the azimuth gimbal 40.
An elevation angle oscillator 34 that outputs a signal indicating the rotation angle θ of the surrounding antenna 14, an output signal of the second accelerometer 47, an output signal of the third accelerometer 48, and an output signal of the elevation angle oscillator 34. And a tilt correction calculation unit 93 that calculates a tilt correction value Δφ _A by inputting a signal obtained by subtracting a value corresponding to the altitude angle of the satellite from the output signals of the accelerometers 46, 47 and 48 in the first gyro. The output signal of the azimuth transmitter 24, the signal corresponding to the bow azimuth angle and the satellite azimuth angle, and the signal indicating the tilt correction value Δφ _A output from the tilt correction calculation unit 93 are fed back to the elevation angle control integrator 54 of 44. The adder 61 calculates the output signal and feeds back the output signal to the azimuth angle control integrator 58 of the second gyro 45, and the central axis X of the antenna
-In the antenna pointing device configured to direct X to the satellite, the tilt correction value Δφ _A supplied from the tilt correction calculation unit 93, the satellite altitude angle θ _S, and the elevation axis Y-supplied from the elevation transmitter 34. A swing angle calculation unit 94 that calculates the swing angles η and ξ of the mounting surface of the antenna pointing device based on the rotation angle θ of the antenna around Y, and the swing angles η and ξ supplied from the swing angle calculation unit 94 and tilt correction. The inclination correction value Δφ _A supplied from the calculation unit 93, the rotation angle θ of the antenna around the elevation axis Y-Y supplied from the elevation transmitter 34, the output value of the elevation control integrator 54, and the azimuth control integrator 58. The servo deviation correction calculation unit 120 that inputs the output value and calculates the detected angular velocity deviation of the first gyro 44 and the second gyro 45
And a third adder 125 for inputting and adding the output of the servo deviation correction calculator 120 and the output of the first gyro 44.
And a fourth adder 126 for inputting and adding the output of the servo deviation correction calculation unit 120 and the output of the second gyro 45.
And are provided, and the azimuth axis Z is generated by the motion of the hull or the like.
The detected angular velocity deviation generated in the output of the gyro is corrected by the following deviation around -Z and the following deviation around the elevation axis YY.

According to the present invention, in the antenna directing device, the swing angle calculating section 94 calculates the swing angles η and ξ of the mounting surface of the antenna directing device by the following equation. η = tan ⁻¹ (sin Δφ _A / tan θ) θ _S −ξ = tan ⁻¹ (tan Δφ _A / sin η) where η and ξ are the shaking angles of the mounting surface Δφ _A : the tilt correction value θ: the output signal of the elevation transmitter θ _S : Satellite altitude angle

According to the present invention, in the antenna pointing device, the servo deviation correction calculation unit 120 calculates the detected angular velocity deviations ha and he of the first gyro 44 and the second gyro 45 by the following equation. ha = −ξ ₁ [sin η {cos (θ−X _E ) −cos θ} + cos η {sin (Δφ _A + X _A ) · sin (θ−X _E ) −sin Δφ _A · sin θ}] + η ₁ {cos (Δφ _A + X _A ) · sin (θ−X _E ) −cos Δφ _A · sin θ} + dφ / dt {cos (θ−X _E ) −cos θ} he = ξ ₁ cos η {cos (Δφ _A + X _A ) −cos Δφ _A } + η ₁ { sin (Δφ _A + X _A ) −sin Δφ _A }

Θ: rotation angle of the antenna 14 around the elevation axis YY Δφ _A : rotation angle of the antenna 14 around the azimuth axis ZZ dθ / dt: rotation angular velocity of the antenna 14 around the elevation axis YY dφ / dt: rotational angular velocity of the antenna 14 around the azimuth axis Z-Z ξ ₁ : first-order derivative of the rocking angle ξ with respect to time η ₁ : first-order derivative of the rocking angle η with respect to time X _A : output of the azimuth control integrator 58 X _E : Output of elevation angle integrator 54

According to the present invention, in the antenna pointing device, the swing angles η and ξ output from the swing angle calculation unit 93, the tilt correction value Δφ _A output from the tilt correction calculation unit 93, and the preset estimated time. An azimuth servo deviation limiter value calculating unit for calculating the azimuth angle after the predicted time by inputting Δt _Y and calculating and outputting the azimuth servo deviation from the difference between the azimuth angle after the predicted time and the current azimuth angle. The output of the azimuth servo deviation limiter value calculation unit and the output of the integrator that inputs the second next output are input, and the azimuth servo deviation limiter value calculation unit 121 is input.
And a servo deviation limiter 122 that limits the output of the azimuth angle control integrator 58 by the output of the azimuth angle control integrator 58, and prevents the runaway of the azimuth servomotor 23 that rotates the antenna about the azimuth axis ZZ when the elevation angle of the antenna is large. Is configured.

According to the present invention, in the antenna pointing device, the azimuth servo deviation limiter value calculation unit 121 calculates the azimuth servo deviation limiter value Δφ _L by the following equation.

However, Δφ _L : azimuth servo deviation limiter value A = φ _S −φ _C −φ B = sin η _Y tan (θ _S −ξ _Y ) φ _S : satellite azimuth φ _C : bow azimuth φ: antenna 14 Rotation angles around the azimuth axis ZZ of ξ _Y , η _Y : Swing angle after the elapse of the predicted time Δt _Y

[0056]

According to the present invention, the servo deviation correction calculation unit 120 is provided.
In equation (15), the detected angular velocity deviations ha and he of the elevation gyro 44 and the azimuth gyro 45 are calculated,
The output angular velocities ω _Y2 and ω _{P2 of the} elevation angle gyro 44 and the azimuth gyro 45 are corrected by the detected angular velocity deviations ha and he, and the elevation angle control integrator 54 and the azimuth angle control integrator 58 are obtained.
The corrected command signals (elevation angle servo deviation, azimuth angle servo deviation) X _E and X _A are output from the command signals X _E and X A, respectively.
_The elevation angle servo motor 33 and the azimuth servo motor 23 are operated by _A , respectively.

According to the present invention, the azimuth servo deviation limiter value calculation unit 121 calculates the azimuth servo deviation limiter value Δφ _L according to the equation (18), and supplies the azimuth servo deviation limiter value Δφ _L to the azimuth servo motor 23. The command signal that is issued is limited.

According to the present invention, the servo deviation limiter 12
2, the azimuth servo deviation X _A is limited by the equation 20 and the azimuth servo deviation limiter value Δφ _L is supplied as a command signal to the azimuth servo motor 23 via the amplifier 59 instead of the azimuth servo deviation X _A.

[0059]

Embodiments of the present invention will be described below with reference to FIGS. 1 to 4, corresponding parts in FIG. 5 are designated by the same reference numerals, and detailed description thereof will be omitted.

FIG. 1 shows an example of an antenna directing device of the present invention. The antenna directing device is a base 3 and such a base 3.
The azimuth gimbal 40 mounted on the azimuth gimbal 40, the mounting bracket 41 mounted on the U-shaped member at the upper end of the azimuth gimbal 40, and the antenna 14 mounted on the mounting bracket 41.

The antenna 14 has a central axis line XX, and the assembly consisting of the antenna 14 and the mounting bracket 41 attached to the antenna 14 has an elevation axis line YY which is orthogonal to the central axis line XX. It is rotatably supported around. The azimuth gimbal 40 is supported by the base 3 so as to be rotatable about an azimuth axis ZZ orthogonal to the elevation axis YY.
In this way, a support mechanism rotatable about two axes is configured, and such a support mechanism is controlled so that the central axis line XX of the antenna 14 points the satellite.

The mounting bracket 41 includes an elevation gyro 44.
Further, an azimuth gyro 45, a first accelerometer 46, a second accelerometer 47 and a third accelerometer 48 are attached.

The elevation gyro 44 causes the elevation axis Y--Y.
The angular velocity of rotation of the antenna 14 rotating around is detected,
The azimuth gyro 45 detects the rotational angular velocity of the antenna 14 around an axis orthogonal to both the elevation axis YY and the center axis XX of the antenna 14, and the first accelerometer 46.
The central axis line XX of the antenna 14 with respect to the horizontal plane
Is detected, and the second accelerometer 47 detects the inclination angle of the elevation axis YY with respect to the horizontal plane.

The third accelerometer 48 is the first accelerometer 46.
Of the second accelerometer 47 and the input axis of the second accelerometer 47 are orthogonal to each other. Therefore, the third accelerometer 48 has a central axis X− of the antenna 14.
The tilt angle of the axis line orthogonal to both X and the elevation axis line Y-Y with respect to the horizontal plane is detected.

The elevation angle gyro 44 and the azimuth gyro 45 may be angular velocity detection type gyros such as a vibration gyro and a rate gyro.

The antenna pointing device of this example has an elevation angle control loop and an azimuth angle control loop. The elevation angle control loop controls the antenna 14 so that the elevation angle θ _A of the antenna matches the satellite elevation angle θ _S. Configured to rotate about -Y, the azimuth control loop is configured to rotate the antenna 14 about the azimuth axis ZZ such that the azimuth angle φ _A of the antenna matches the azimuth angle φ _{S of the} satellite. ing. still,
Detailed description of portions similar to those of the conventional example in FIG. 5 will be omitted.

According to the present example, as compared with the conventional control loop, the swing angle calculation unit 94 and the servo deviation correction calculation unit 1 are newly added.
20, an azimuth servo deviation limiter value calculation unit 121 and a servo deviation limiter 122 are provided. Further, third and fourth adders 125 and 126 for inputting the output signal of the servo deviation correction calculation unit 120 are provided.

The sway angle calculation unit 94 uses the signal indicating the tilt correction value Δφ _A output from the tilt correction calculation unit 93 and the rotation angle θ of the antenna 14 about the elevation axis YY output from the elevation transmitter 34. By inputting a signal for instructing and a signal for instructing the satellite altitude angle θ _S , the swing angles η, ξ of the hull surface, that is, the swing angles η, ξ of the mounting surface of the hull on which the antenna directing device is mounted are calculated.

The servo deviation correction calculation unit 120 determines the swing angle performance.
A signal indicating the shaking angles η and ξ calculated by the calculation unit 94.
And the output signal of the first integrator, that is, the elevation angle control integrator 54.
Issue X _EAnd the second integrator, namely the azimuth control integrator 58
Output signal X_AAnd the inclination output from the inclination correction calculation unit 93
Correction value Δφ_AOutput from the elevation transmitter 34
Rotation angle θ of the antenna 14 around the selected elevation axis YY
Input the signal to instruct the elevation gyro 44 and azimuth.
Detection angle ω of gyro 45_Y, Ω_ZThe deviation of he, ha
Calculate

The third adder 125 inputs the output signal ω _Y of the elevation gyro 44 and the deviation signal he, corrects the output signal ω _Y of the elevation gyro 44, and integrates the corrected value in the elevation control integration. Output to the device 54. The fourth adder 126 inputs the output signal ω _Z of the azimuth gyro 45 and the deviation signal ha, corrects the output signal ω _Z of the azimuth gyro 45, and outputs the corrected value via the secθ calculation unit 76. And outputs it to the azimuth control integrator 58.

The azimuth servo deviation limiter value calculation unit 121
Indicate the shaking angles η and ξ output from the shaking angle calculation unit 94.
Signal and the tilt correction value output from the tilt correction calculation unit 93
Δφ _ASignal to indicate the satellite altitude angle θ_SSignal to tell
And expected time Δt_YInput a signal to instruct
Thought time Δt_YCalculate the azimuth angle of the antenna 14 after the passage
It The predicted azimuth and the current azimuth φ_AAnd compare
If the difference between the two exceeds a specified value, the direction servo deviation
Mitter value Δφ_LGenerate a servo deviation limiter 1
22.

When the azimuth servo deviation limiter value calculation unit 121 outputs the azimuth servo deviation limiter value Δφ _L , the servo deviation limiter 122 limits the output of the azimuth angle control integrator 58, and the azimuth angle control integrator 58 is provided. The azimuth servo deviation limiter value Δφ _L is supplied to the amplifier 59 instead of the output of

The function and operation of the swing angle calculating section 94 of this example will be described with reference to FIG. FIG. 2 considers a unit spherical surface with a radius of 1, and considers the unit spherical surface and the central axis line XX of the antenna 14.
(Line segment OX in FIG. 2), elevation axis line YY (line segment OY, OY ′ in FIG. 2), azimuth axis line ZZ (line segment OZ in FIG. 2).
OZ ′), and an axis line orthogonal to both the center axis line XX of the antenna 14 and the elevation axis line YY (line segments OP and O in FIG. 2).
It is a figure which shows the relationship of P '). The azimuth axis ZZ is always perpendicular to the hull plane (plane parallel to the mounting surface of the antenna directing device), and the elevation axis YY is always parallel to the hull plane.

Consider a case where the hull rotates about the first rotation axis by the rotation angle (sway angle) ξ and further rotates about the second rotation axis by the rotation angle (sway angle) η. Due to such a rotational movement of the hull, for example, as shown in the figure, the hull surface is rotated about the elevation axis YY (OY) with respect to the horizontal plane by a rotation angle ξ.
It is assumed that the vehicle has rotated by a rotation angle η, and further has rotated by a rotation angle η around the hull OE line. At this time, the elevation axis YY is the first
Is parallel to the axis of rotation of the ship, and the hull's tail line OE is parallel to the second axis of rotation.

By the movement of the hull surface, the azimuth axis Z
-Z moves from line OZ to line OZ 'and elevation axis Y-Y moves from line OY to line OD. In addition, ∠XOY = ∠XOD
= 90 °. The central axis X-X of the antenna 14 also moves, but the central axis X of the antenna 14 is moved by the control loop.
-X is controlled to point in the satellite direction. That is, the central axis line XX of the antenna 14 moves to a position deviated from the line OX and moves to the line OX again.

By this control, the elevation axis Y-Y rotates about the azimuth axis OZ 'by the rotation angle Δφ _A and moves from the line OD to the line OY'. Incidentally, ∠XOY '= 90 °.
Eventually, the line OY moves to the line OY ′ via the line OD, and at the same time, the line OP orthogonal to both the central axis line XX and the elevation axis line YY of the antenna 14 becomes the line OP ′. Moving. ∠POP '= ∠Y'OY and arc PP' = arc Y '
It is Y.

The lines OX, OY and OP are lines of length 1 which are 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, a point P and a point P'are connected by a straight line on the unit spherical surface. The arc XP is orthogonal to the horizontal plane at the point A, and further the point P
At right angles to the plane OY'P '. The arc XP ′ is orthogonal to the hull surface (mounting surface) at the point C, and further the surface OY ′ at the point P ′.
It is orthogonal to 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 ′.

Here, ∠XOA = θ ₀ = arc XA, ∠PO
A = θ _P0 = arc PA, ∠BOD = η = arc BD, ∠XOC =
θ = arc XC, ∠P'OA '= θ _P = arc P'A', ∠Y '
OB '= x = arc Y'B'.

The first accelerometer 46 is mounted along the line OX, and the second accelerometer 47 is mounted along the line OY.
The third accelerometer 48 is mounted along the line OP.
When the ship surface is the same as the horizontal surface, the elevation angle transmitter 34 outputs the inclination angle ∠XOA = θ ₀ of the central axis line XX of the antenna 14 with respect to the ship surface, and the first accelerometer 46 outputs sin∠XOA = sin θ. ₀ is detected, the second accelerometer 47 detects sin∠YOB = sin0 = 0, and the third accelerometer 48 detects sin∠POA.
= Sin θ _P0 is detected.

As described above, when the hull surface rotates about the elevation axis YY (OY) with respect to the horizontal plane by the rotation angle ξ, and further around the hull tail line OE by the rotation angle η,
The elevation angle transmitter 34 outputs the inclination angle ∠XOC = θ of the central axis XX of the antenna 14 with respect to the hull surface, and the first angle
Sin ∠XOA = sin θ ₀ is detected by the accelerometer 46 of the above, and sin ∠Y′O is detected by the second accelerometer 47.
B ′ = sinx is detected, and the third accelerometer 48 detects sin∠P′OA ′ = sin θ _P. First
Value detected by accelerometer 46 of sin∠XOA =
sin θ ₀ does not change because the satellite altitude angle θ _S (= θ
_A. ) Is unrelated to the motion of the hull surface.

Next, the relationship between the tilt correction value Δφ _A and the shaking angles η and ξ will be determined. Tilt correction value Δφ _A = arc EC = arc D
Y '. The inclination correction value Δφ _A is, as described above,
It is obtained by the formula of the equation 2. By applying the theorem of spherical trigonometry, the following equation 6 is obtained.

[0083]

## EQU6 ## sin Δφ _A = tan η · tan θ cos η = sin θ / sin (θ _S −ξ) cos Δφ _A · cos θ = cos (θ _S −ξ)

Here, η and ξ are swing angles, Δφ _A is a tilt correction value, and θ is a rotation angle of the antenna around the elevation axis YY with respect to the azimuth gimbal 40. If the shaking angles η and ξ are obtained from the equation (6), the following equation (7) is obtained.

[0085]

Η = tan ⁻¹ (sin Δφ _A / tan θ) θ _S −ξ = tan ⁻¹ (tan Δφ _A / sin η)

According to this example, the swaying angle calculation unit 94 executes the calculation of the equation (7) to obtain the swaying angles η and ξ. The signals instructing the fluctuation angles η and ξ are supplied from the fluctuation angle calculation unit 94 to the servo deviation correction calculation unit 120 and the azimuth servo deviation limiter value calculation unit 121.

The inclination correction value Δφ _A can be obtained as an output value of the inclination correction calculation unit 93, but is preferably obtained as follows. The fourth loop is configured to control the azimuth of the azimuth gimbal 40 so that the output of the adder 61 becomes zero. Therefore, when the output of the adder 61 is zero, the following equation 8 is used. Is established.

[0088]

[Equation 8] Δφ _A = φ _S −φ _C −φ

Here, φ _S is the satellite azimuth angle, φ _C is the bow azimuth angle, and φ is the rotation angle of the azimuth gimbal 40 output by the azimuth oscillator 24. Each term on the right side of the equation (8) can be obtained as a value that is not directly affected by the shaking acceleration or a value that is less affected by the shaking acceleration.
Therefore, the inclination correction value Δφ _A may be obtained by using the equation of Expression 8 instead of using the output value of the inclination correction calculation unit 93.

Next, the mechanism that causes the azimuth servo deviation will be described. The azimuth servo deviation occurs when the value of the rotation angle θ around the elevation axis YY of the antenna 14 becomes close to 90 ° due to the motion of the hull as described above. In particular, the satellite altitude angle θ
_It tends to occur when _S is high. The rotation angle θ is output from the elevation transmitter 34.

By eliminating the rotation angle θ from the equation (6), the following equation (9) is obtained.

[0092]

Tan Δφ _A = sin η · tan (θ _S −ξ)

The equation (9) is differentiated with respect to time, and the equation (6) is used to obtain the first-order differential value d of the inclination correction value Δφ _A with respect to time.
Calculate Δφ _A / dt.

[0094]

D Δφ _A / dt = η ₁ cos Δφ _A · tan θ−ξ ₁ (sin η + cos η · sin Δφ _A · tan θ)

Here, η ₁ and ξ ₁ are first-order derivatives of the fluctuation angles η and ξ with respect to time, that is, η ₁ = (dη / dt), ξ
₁ = (dξ / dt).

The value obtained by first-order differentiating the tilt correction value Δφ _A with respect to time is obtained by rotating the antenna 14 (or the azimuth gimbal 40) around the azimuth axis ZZ when the swaying angular velocities η ₁ and ξ ₁ occur in the hull. It represents the rotational angular velocity required for the rotation.

As is clear from the equation (10), when the rotation angle θ about the elevation axis Y-Y of the antenna 14 output by the elevation transmitter 34 is 90 °, the antenna 14 (or the azimuth gimbal 40). The rotational angular velocity dΔφ _A / dt (= −dφ / dt) about the azimuth axis line ZZ becomes infinite.

The rotational angular velocity that can be achieved by the actual azimuth servomotor 23 is finite, so that a tracking error or azimuth servo deviation occurs in the azimuth angle control of the antenna 14 by the azimuth control loop, and the central axis X of the antenna 14 is generated. -X will be deviated from the satellite direction.

When there is no azimuth servo deviation in the azimuth control by the azimuth control loop, and the azimuth of the central axis XX of the antenna 14 is accurately oriented in the satellite direction, the output of the azimuth control integrator 58 is When it is zero, but the azimuth servo deviation has occurred, the azimuth control integrator 58 outputs the azimuth servo deviation X _A.

The state of the antenna directing device when the azimuth servo deviation occurs will be described with reference to FIG. Similar to FIG. 2, FIG. 3 considers a unit spherical surface having a radius of 1, and considers the unit spherical surface and the central axis line XX of the antenna 14 (the line segment OX in FIG.
₁ , OX ₂ ), elevation axis Y-Y (segments OY, O in FIG. 3)
Y ₁ , OY ₂ ), azimuth axis ZZ (line segment OZ in FIG. 3,
OZ ₁ ), and an axis line orthogonal to both the central axis line XX of the antenna 14 and the elevation axis line YY (segments OP and O in FIG. 3).
P _1, OP _2), a diagram showing the relationship. Azimuth axis Z-
Z is always perpendicular to the hull surface, and the elevation axis YY is always parallel to the hull surface.

Due to the shaking of the hull, the hull surface rotates about the elevation axis YY (OY) with respect to the horizontal plane by the rotation angle ξ, whereby the azimuth axis ZZ changes from the line OZ to the line OZ _1.
And the hull surface further rotates about the hull's tail line OE by a rotation angle η, whereby the elevation axis YY is line OY.
Suppose we have moved from to line OD.

The antenna 14 is moved by the movement of the ship surface.
The central axis XX of the antenna 14 also moves, but the central axis XX of the antenna 14 is controlled by the control loop so as to point in the satellite direction. If the azimuth servo deviation and the elevation servo deviation do not occur in the control system, the central axis X-X of the antenna 14 accurately points in the satellite direction. That is, the central axis X-X of the antenna 14 is moved to a position offset from the line OX ₁ moves to the line OX ₁ again.

However, it is assumed that the central axis line XX of the antenna 14 is moved to the line OX ₂ instead of the line OX ₁ due to the azimuth servo deviation and the elevation angle servo deviation.

At this time, the azimuth control loop causes the antenna 14 (azimuth gimbal 40) to move the azimuth axis ZZ (line OZ).
₁ ) Around the rotation angle Δφ _A2 instead of the rotation angle Δφ _A1 , so that the elevation axis Y-Y rotates on the hull surface about the azimuth axis OZ _{1 by the} rotation angle Δφ _A2 instead of the rotation angle Δφ _A1. , Line OD to line OY ₂ instead of line OY ₁ .

The central axis line XX and the elevation axis line of the antenna 14
The line OP orthogonal to both Y-Y is the line OP.₁Not a line
OP₂Move to. In addition, ∠X₂OY₂= 90 °.
After all, the line OY passes through the line OD and the line OY₂Moved to
And ∠POP₂= ∠Y ₂OD and arc PP₂= Arc Y
₂It is Y.

Line OX₂, Line OY₂And line OP₂Are each other
A line with a length of 1 that intersects at right angles₂Y₂P₂Is one side
Becomes a π / 2 equilateral spherical triangle. Point X on the unit sphere
₂And point P₂Connect with a straight line. Arc X₂P₂Is point C₂At hull
Orthogonal to the surface (mounting surface), and point P₂At OY₂P
₂Orthogonal to. Similarly point X₁And point P₁Connect with a straight line. Arc
X₁P₁Is point C₁At right angles to the hull surface (mounting surface),
Further point P₁At OY ₁P₁Orthogonal to.

Further, the antenna 1 is controlled by the elevation control loop.
4 rotates about the elevation axis YY by the rotation angle θ. Here, ∠X ₂ OC ₂ = θ ₂ = arc X ₂ C ₂ , ∠X ₁ OC ₁ =
θ ₁ = arc X ₁ C ₁ . The angle of rotation θ of the antenna 14 around the elevation axis Y-Y or the angles θ ₁ and θ ₂ formed by the central axis X-X of the antenna 14 with the hull surface are detected by the elevation transmitter 34.

There is no azimuth servo deviation and elevation servo deviation.
If so, the elevation gyro 44 is the line OY.₁Are placed along
Therefore, the line OY₁Rotational angular velocity ω of the surrounding antenna 14_Y1
Azimuth gyro 45 detects line OP₁Arranged along
And therefore line OP₁Rotational angular velocity of the surrounding antenna 14
ω_P1To detect. However, azimuth servo deviation and elevation
If there is an angular servo deviation, the elevation gyro 44 will move to the line OY.₂To
Placed along the line OY₂Rotation angle of the surrounding antenna 14
Speed ω_Y2Azimuth gyro 45 detects line OP ₂Along
Placed, line OP₂Rotational angular velocity of the surrounding antenna 14
ω_P2To detect. The rotation angular velocity is expressed by the following equation.
To be done.

[0109]

[Number 11] _{ω Y1 = ξ 1 cosη · cosΔφ} A1 + η 1 sinΔφ A1 + dθ / dt ω P1 = -ξ 1 (sinη · cosθ 1 + cosη · sinΔφ A1 · sinθ 1) + η 1 cosΔφ A1 · sinθ 1 -dΔφ A1 / _{dt · cosθ 1 ω Y2 = ξ} 1 cosη · cosΔφ A2 + η 1 sinΔφ A2 + dθ / dt ω P2 = -ξ 1 (sinη · cosθ 2 + cosη · sinΔφ A2 · sinθ 2) + η 1 cosΔφ A2 · sinθ 2 -dΔφ A2 / dt ・ cos θ ₂

Next, the function of the servo deviation correction calculator 120
Will be explained. The servo deviation correction calculation unit 120
Detected angular velocity when there is no deviation or elevation servo deviation
ω_Y1, Ω _P1And azimuth servo deviation and elevation servo deviation
Detected angular velocity ω_Y2, Ω_P2Difference, that is, the detected angular velocity deviation
The differences ha and he are calculated. Such detected angular velocity deviation he,
ha is represented by the following formula.

[0111]

Equation 12 he = ω _Y1 −ω _Y2 ha = ω _P1 −ω _P2

The rotation angles θ ₁ and θ ₂ of the antenna 14 around the elevation axis YY and the elevation control integrator 54 of the elevation control loop.
Output (elevation angle servo deviation) X _E and the rotation angles Δφ _A1 , Δφ _A2 of the antenna 14 around the azimuth axis ZZ and the output of the azimuth control integrator 58 of the azimuth control loop (azimuth servo). The relationship between the deviation) X _A is represented by the following equation.

[0113]

[Equation 13] θ ₁ = θ ₂ −X _E Δφ _A1 = Δφ _A2 + X _A

Here, θ ₂ is replaced with θ, and Δφ _A2 is replaced with Δφ _A.

[0115]

[Equation 14] θ ₁ = θ−X _E Δφ _{A 1} = Δφ _A + X _A

By substituting the equations of the equation 11 and the equation 14 into the equation of the equation 12, the following equation is obtained.

[0117]

[Equation 15] ha = −ξ ₁ [sin η {cos (θ−X _E ) −cos θ} + cos η {sin (Δφ _A + X _A ) · sin (θ−X _E ) −sin Δφ _A · sin θ}] + η ₁ {cos (Δφ _A + X _A ) · sin (θ−X _E ) −cos Δφ _A · sin θ} + dφ / dt {cos (θ−X _E ) −cos θ} he = ξ ₁ cos η {cos (Δφ _A + X _A ) −cos Δφ _A } + Η ₁ {sin (Δφ _A + X _A ) −sin Δφ _A }

Θ: Rotation angle of the antenna 14 around the elevation axis YY Δφ _A : Rotation angle of the antenna 14 around the azimuth axis ZZ dθ / dt: Rotational angular velocity of the antenna 14 around the elevation axis YY dφ / dt: Rotational angular velocity of the antenna 14 around the azimuth axis Z-Z ξ ₁ : First-order derivative of the oscillation angle ξ with respect to time η ₁ : First-order derivative of the oscillation angle η with respect to time X _A : Output of the azimuth control integrator 58 ( Azimuth angle servo deviation) X _E : Output of elevation angle control integrator 54 (elevation angle servo deviation)

The detected angular velocity deviation he of the elevation gyro 44 and the detected angular velocity deviation ha of the azimuth gyro 45 are supplied to adders 125 and 126, respectively. In the third adder 125, the angular velocity ω _Y2 output from the elevation gyro 44 is corrected by the angular velocity deviation he, and in the fourth adder 126, the angular velocity ω _P2 output from the azimuth gyro 45 is corrected by the angular velocity deviation ha. To be done.

Therefore, the angular velocity output from the third adder 125 is the angular velocity ω _Y1 output from the elevation gyro 44, assuming that the central axis XX of the antenna 14 is oriented in the satellite direction. And the angular velocity output from the fourth adder 126 is the central axis line XX of the antenna 14.
Is the angular velocity ω _P1 output from the azimuth gyro 45 when it is assumed that is pointing in the satellite direction.

The corrected output signals of the elevation angle gyro 44 and the azimuth gyro 45 are supplied to the elevation angle control integrator 54 and the azimuth angle control integrator 58, respectively.
The command signals X _E and X _A output from the elevation angle control integrator 54 and the azimuth angle control integrator 58 are supplied to the elevation angle servo motor 33 and the azimuth servo motor 23 via amplifiers 55 and 59, respectively.

Thus, according to this example, the azimuth servo deviation and the elevation angle servo deviation occur, and the central axis X- of the antenna 14
Even when X is deviated from the satellite direction, the antenna 14
Assuming that the central axis line XX of the above is oriented in the satellite direction, the command signals X _E and X _A are supplied to the elevation angle servo motor 33 and the azimuth servo motor 23. Due to this, the central axis line XX of the antenna 14 is not further deviated from the satellite direction.

Next, the azimuth servo deviation limiter value calculation unit 1
21 and the function of the servo deviation limiter 122 will be described.
The azimuth servo deviation limiter value calculation unit 121 and the servo deviation limiter 122 function so as to prevent the command signal supplied to the azimuth servo motor 23 from becoming maximum and the azimuth servo motor 23 from running out of control.

As described with reference to the equation (4), when the rotation angle θ of the antenna 14 about the elevation axis Y-Y output from the elevation transmitter 34 becomes close to 90 °, it is supplied to the azimuth servo motor 23. The value of the commanded angular velocity dφ / dt becomes maximum, and the azimuth servomotor 23 runs out of control.

According to this example, the azimuth servo motor 23 is provided.
The maximum command signal value delivered is limited, which
The azimuth servo motor 23 is configured to prevent runaway.
Has been. The direction servo deviation limiter value calculation unit 121 is
Position servo deviation limiter value Δφ _LCalculate and servo it
It is supplied to the deviation limiter 122. Such direction servo deviation
Limiter value Δφ_LIs supplied to the azimuth servo motor 23
Shows the maximum allowable value of the command signal.

According to this example, the azimuth servo deviation limiter value
Δφ_LIs the set expected time Δt _YDirection sir after passing
Bo deviation X_AIs used. Azimuth servo deviation limiter performance
The calculation unit 121 calculates the estimated time Δt._YDirection servo deviation after the passage
X_A(= Δφ_L) Is calculated.

[0127] The use of phi-X _A corrected by the azimuth servo polarized servo X _A instead of phi at the number 8 of the formula the following equation is obtained.

[0128]

[Expression 16] Δφ _A = φ _S −φ _C − (φ−X _A )

Substituting the expression of the equation 16 into the expression of the equation 9, the current motion
Expected time Δt instead of swing angles ξ and η _YSwing angle after passage ξ
_Y, Η_YWould be like this:

[0130]

Tan (φ _S −φ _C −φ + X _A ) = sin η
_Y tan (θ _S −ξ _Y )

From the equation (17), the direction servo deviation X_AAbout
The solution is as follows. However, the direction servo deviation X_A
Azimuth servo deviation limiter value Δφ_LReplace with. Immediately
C, X _A= Δφ_LAnd

[0132]

[Equation 18]

[0133] _{However, A = φ S -φ C -φ} B = sinη Y tan (θ S -ξ Y) η Y, ξ Y: expected time Delta] t _Y upset angle after phi _S: Satellite azimuth phi _C: Bow azimuth angle φ: Rotation angle of azimuth axis line ZZ of antenna 14

The value obtained by the arctangent calculation of the equation 18 is the azimuth servo deviation limiter value Δφ _L output from the azimuth servo deviation limiter value calculation unit 121.

Shaking angles η _Y , ξ _Y after the expected time Δt _{Y has} elapsed
Is expressed as follows for the first-order approximation of Taylor's expansion of the fluctuation angle as a function of time.

[0136]

[Formula 19] ξ _Y = ξ + ξ ₁ Δt _Y η _Y = η + η ₁ Δt _Y

The servo deviation limiter 122 outputs the absolute value of the azimuth servo deviation limiter value Δφ _L output from the azimuth servo deviation limiter value calculation unit 121 and the absolute value of the azimuth servo deviation X _A output from the azimuth angle control integrator 58. To compare. When the absolute value of the azimuth servo deviation X _A is greater than the absolute value of the azimuth servo deviation limit value [Delta] [phi _L, azimuth servo deviation X _A is limited. This can be expressed as follows.

[0138]

[Formula 20] | X _A |> | Δφ _L |: X _A = SGN (X _A ) · | Δφ _L | | X _A | ≦ | Δφ _L |: X _A = X _A

Here, SGN (X _A ) represents the code of X _A.

In this way, when the azimuth servo deviation X _A is limited, the azimuth servo deviation limiter value Δφ _L is supplied as a command signal to the azimuth servo motor 23 via the amplifier 59 instead of the azimuth servo deviation X _A.

At the same time, the azimuth servo deviation limiter value Δφ _L is also supplied to the azimuth angle control integrator 58, and the output output from the azimuth angle integrator 58 is replaced by this azimuth servo deviation limiter value Δφ _L. To be

Thus, according to this example, the command signal supplied to the azimuth servo motor 23 does not exceed the azimuth servo deviation limiter value Δφ _L.
The antenna 3 does not rotate at a high speed due to the runaway of the antenna 3.

According to this example, when the hull is swaying, the command signal supplied to the azimuth servo motor 23 is limited by the azimuth servo deviation limiter value Δφ _L. The azimuth servo deviation limiter value Δφ _L is, as expressed by the equation (18), the sway angle η of the hull after the expected time has elapsed.
It is a function of _Y and ξ _Y. Since the sway angles η _Y and ξ _Y of the hull after the elapse of the expected time are functions of the current sway angles ξ and η and the sway angular velocities ξ ₁ and η ₁ as represented by the equation (19), the azimuth servo The deviation limiter value Δφ _L is a function of the current shaking angles ξ and η and the shaking angular velocities ξ ₁ and η ₁ .

In this example, consider the case where the hull is not shaken. Even when the hull is stationary,
When the central axis line XX of the antenna 14 faces the zenith direction, the rotation angle θ output from the elevation angle transmitter 34 is 9
It approaches 0 °. Therefore, in the conventional device, the command signal supplied to the azimuth servo motor 23 becomes maximum according to the equation (9), and the azimuth servo motor 23 runs out of control.

However, according to this example, when the hull is stationary, the swing angles ξ and η and the swing angular velocities ξ ₁ and η ₁ of the hull are zero. The value Δφ _L (= X _A ) is − (φ _S −φ _C −
φ). When the hull is stationary, the inclination correction value Δφ _A (= φ _S −φ _C −φ) is zero as shown in the equation (6). Therefore, when the hull is stationary, the azimuth servo deviation limiter value Δφ _L is zero.

In this way, the command signal supplied to the azimuth servo motor 23 becomes zero, and the azimuth angle of the antenna 14 is prevented from gradually deviating from the satellite azimuth, and the antenna 1
The central axis line XX of 4 can be oriented in the satellite direction.

Next, FIG. 4 shows an actual calculation example showing the effect of the present invention. Satellite azimuth angle φ _S = 0 °, satellite altitude angle θ _S = 7
It is assumed to be 5 °. FIG. 4A shows the swaying motion of the hull, where the horizontal axis is the time and the vertical axis is the rotation inclination angle.
As shown in the figure, the hull surface is statically tilted about the pitch axis at a constant angle and dynamically tilted about the roll axis in a sinusoidal manner.

FIG. 4B shows the change in the value of the azimuth angle φ, the horizontal axis is the time, and the vertical axis is the azimuth angle of the antenna 14. The solid line shows the result of this example, and the broken line shows the result of the conventional example. As shown in the figure, the tracking error increases with time in the conventional example, but does not increase in this example.

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 is apparent to those skilled in the art that various other configurations can be adopted without departing from the gist of the present invention. Easy to understand.

[0150]

According to the present invention, the detected angular velocity deviations ha and he of the elevation gyro 44 and the azimuth gyro 45 are calculated by the equation 15 in the servo deviation correction calculator 120, and the detected angular velocity deviations ha and he are calculated. Output angular velocities ω _Y2 , ω of the elevation gyro 44 and the azimuth gyro 45
_P2 is corrected, and thereby the command signals X _E and X _A corrected by the elevation control integrator 54 and the azimuth control integrator 58.
Is output, and the elevation servomotor 33 and the azimuth servomotor 23 are operated by the command signals X _E and X _A , respectively, so that the central axis XX of the antenna 14 can favorably point in the satellite direction. There is.

According to the present invention, the azimuth servo deviation limiter value calculator 121 calculates the azimuth servo deviation limiter value Δφ _L according to the equation (18) and supplies the azimuth servo deviation limiter value Δφ _L to the azimuth servo motor 23. Since the command signal to be generated is limited, there is an advantage that the azimuth servo motor 23 does not run away even when the rotation angle θ of the antenna 14 around the elevation axis YY becomes close to 90 ° as in the conventional case. is there.

According to the present invention, the servo deviation limiter 12
2, the azimuth servo deviation X _A is limited by the equation 20 and the azimuth servo deviation limiter value Δφ _L is supplied as a command signal to the azimuth servo motor 23 via the amplifier 59 instead of the azimuth servo deviation X _A. , The rotation angle θ of the antenna 14 around the elevation axis YY is 9 as in the conventional case.
There is an advantage that the azimuth servo motor 23 does not run away even when the angle is close to 0 °.

[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 an antenna directing device on a unit spherical surface.

FIG. 3 is an explanatory diagram illustrating an operation of the antenna directing device on a unit spherical surface.

FIG. 4 is a diagram showing the performance of the antenna pointing device of the present invention.

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

[Explanation of symbols]

 3 pedestal 3-1 bridge part 11 cylindrical part 13 arm 14 antenna 20 azimuth axis 21-1, 21-2 bearing 22 azimuth gear 23 azimuth servo motor 24 azimuth transmitter 30-1, 30-2 elevation angle shaft 32 elevation angle gear 33 Elevation servo motor 34 Elevation transmitter 35 Pinion 40 Azimuth gimbal 40-1 Support shaft part 40-2 U-shaped part 41 Mounting brackets 41-1, 41-2 Legs 44 Elevation gyro 45 Azimuth gyro 46 First accelerometer 47 No. 2 accelerometer 48 third accelerometer 54 (elevation angle control) integrator 55 amplifier 56 attenuator 58 (azimuth angle control) integrator 59 amplifier 60 attenuator 61 adder 76 secθ calculation unit 81 antenna elevation angle calculation unit 93 tilt correction Calculation unit 94 Swing angle calculation unit 120 Servo deviation correction calculation unit 121 Direction servo deviation limiter value calculation 122 servo deviation limiter 125 and 126 adders X-X antenna center axis Y-Y elevation axis Z-Z orientation axis

Claims (5)

[Claims] 1. An antenna having a central axis and supported by a supporting member, an azimuth gimbal for rotatably supporting the antenna and the supporting member about an elevation axis orthogonal to the central axis, and the azimuth gimbal. A pedestal rotatably supported around an azimuth axis orthogonal to the elevation axis, a first gyro having an input axis parallel to the elevation axis and fixed to the support member, and both the center axis and the elevation axis. A second gyro fixed to the support member having an input axis orthogonal to the first axis, a first accelerometer for outputting a signal indicating an inclination angle of the central axis with respect to the horizontal plane, and an inclination of the elevation axis with respect to the horizontal plane. A second accelerometer for outputting a signal indicating an angle; a third accelerometer having an input axis orthogonal to both the central axis of the antenna and the elevation axis; and the azimuth axis of the azimuth gimbal. The azimuth transmitter that outputs a signal that indicates a rotation angle around the line, the elevation angle transmitter that outputs a signal that indicates a rotation angle of the antenna about the elevation axis with respect to the azimuth gimbal, and the second accelerometer. And a tilt correction calculation unit for calculating a tilt correction value by inputting the output signal, the output signal of the third accelerometer and the output signal of the elevation angle transmitter, and calculating the tilt correction value from the output signal of the accelerometer of the satellite. The signal obtained by subtracting the value corresponding to the altitude angle is fed back to the elevation control integrator, and the output signal of the above azimuth transmitter, the signal corresponding to the heading azimuth angle and the satellite azimuth angle, and the tilt correction output from the tilt correction calculator the calculated and a signal for instructing the values [Delta] [phi _a by the adder and the output signal is fed back to the azimuth control integrator central axis of the antenna to the antenna directing device configured to direct to the satellite Then, the tilt correction value supplied from the tilt correction calculation unit, the satellite altitude angle, and the rotation angle of the antenna around the elevation angle axis supplied from the elevation angle transmitter and the swing angle of the mounting surface of the antenna pointing device are calculated. And a rotation angle of the antenna around the elevation axis supplied by the elevation transmitter and the inclination correction value supplied by the inclination correction calculation section, the inclination correction value supplied by the inclination correction calculation section, And the output value of the elevation angle control integrator and the output value of the azimuth angle control integrator are input to calculate the detected angular velocity deviation of the first gyro and the second gyro. A third adder for inputting and adding the output of the deviation correction calculation unit and the output of the first gyro, and for inputting and adding the output of the servo deviation correction calculation unit and the output of the second gyro 4 is provided to correct the detected angular velocity deviation generated in the output of the gyro by the tracking error around the azimuth axis and the tracking error around the elevation angle axis, which are caused by the motion of the hull and the like. Antenna pointing device. 2. The antenna directing device according to claim 1, wherein the swing angle calculating section calculates a swing angle of a mounting surface of the antenna directing device according to the following equation. η = tan ⁻¹ (sin Δφ _A / tan θ) θ _S −ξ = tan ⁻¹ (tan Δφ _A / sin η) where η and ξ are the shaking angles of the mounting surface Δφ _A : the tilt correction value θ: the output signal of the elevation transmitter θ _S : Satellite altitude angle 3. The antenna directing device according to claim 1, wherein the servo deviation correction calculator calculates a detected angular velocity deviation between the first gyro and the second gyro according to the following equation. Pointing device. ha = −ξ ₁ [sin η {cos (θ−X _E ) −cos θ} + cos η {sin (Δφ _A + X _A ) · sin (θ−X _E ) −sin Δφ _A · sin θ}] + η ₁ {cos (Δφ _A + X _A ) · sin (θ−X _E ) −cos Δφ _A · sin θ} + dφ / dt {cos (θ−X _E ) −cos θ} he = ξ ₁ cos η {cos (Δφ _A + X _A ) −cos Δφ _A } + η ₁ { _{sin (Δφ a + X a)} -sinΔφ a} θ: rotation angle [Delta] [phi _a elevation axis Y-Y around the antenna 14: rotation angle d [theta] / dt of the azimuthal axis Z-Z around the antenna 14: elevation axis Y-Y about Angular velocity of the antenna 14 of dφ / dt: The angular velocity of rotation of the antenna 14 around the azimuth axis ZZ ξ ₁ : The first derivative of the rocking angle ξ with respect to time η ₁ : The first derivative of the rocking angle η with respect to time X _A : Azimuth output X _E of the corner control integrator 58: elevation angle control Output of the frequency 54 4. The antenna directing device according to claim 1, 2 or 3, wherein the swing angle output from the swing angle calculation unit, the tilt correction value output from the tilt correction calculation unit, and a preset estimated time. And an azimuth angle after the predicted time is calculated by inputting, and an azimuth servo deviation limiter value calculation unit for calculating and outputting the azimuth servo deviation from the difference between the azimuth angle after the predicted time and the current azimuth, and the azimuth. A servo deviation limiter for inputting the output of the servo deviation limiter value calculation unit and the output of the azimuth angle control integrator, and limiting the output of the azimuth angle control integrator by the output of the azimuth servo deviation limiter value calculation unit, An antenna pointing device, which is provided so as to prevent runaway of an azimuth servomotor for rotating the antenna around an azimuth axis. 5. The antenna directing device according to claim 1, 2, 3 or 4, wherein the azimuth servo deviation limiter value calculation unit calculates the azimuth servo deviation limiter value by the following equation. . However, Δφ _L : Azimuth servo deviation limiter value A = φ _S −φ _C −φ B = sin η _Y tan (θ _S −ξ _Y ) φ _S : Satellite azimuth φ _C : Bow azimuth φ: Antenna 14 azimuth axis Rotation angles around Z-Z ξ _Y , η _Y : Swing angle after prediction time Δt _{Y has} elapsed