JP4489654B2 - Antenna control device for satellite tracking - Google Patents

Description

  The present invention relates to an antenna control apparatus for tracking satellites, and more particularly to an antenna control apparatus for tracking satellites that is mounted on a moving body such as a ship, a vehicle, or an aircraft and communicates with a satellite.

  As an antenna control device for tracking a satellite, for example, an antenna control posture device described in Patent Document 1 includes an angular velocity detection unit that detects an angular velocity component of motion of a moving body, and a moving body coordinate by integrating calculation of the detected angular velocity component. Computing means for calculating a coordinate transformation matrix representing the relationship between the coordinates of the earth and the earth, acceleration detecting means for detecting the acceleration component of the moving body motion, direction detecting means using a geomagnetic direction compass or gyrocompass, acceleration detecting means and direction detection The drift component removing means for removing the drift component of the coordinate transformation matrix calculated by the computing means based on the detection output of the means, and the command azimuth angle, command elevation angle, and command polarization angle to be taken by the antenna in the earth coordinate system The second calculation means for determining the command posture matrix and the coordinate conversion matrix A third computing means for converting the antenna attitude matrix into the antenna attitude matrix on the moving body coordinates, and a driving means for controlling the attitude of the antenna mounted on the moving body based on the element components of the antenna attitude matrix. .

Japanese Unexamined Patent Publication No. 7-79111 (paragraph 0005)

  A conventional satellite tracking antenna control apparatus is configured as described above, and generally, an elevation motor on an azimuth drive motor, and a polarization (polarization) motor and three motors on the elevation motor. Therefore, if the moving body rotates in the roll or pitch direction at a driving singularity such as near the zenith where the antenna drive axis yaw and the antenna command direction match, the azimuth drive motor cannot follow and directivity accuracy There was a problem of getting worse. For example, if the satellite direction is in the vicinity of the zenith and the roll direction fluctuates, it is necessary to rotate the azimuth drive motor in a short time in the vicinity of 180 deg, and a large torque is required instantaneously. There was a problem that it could not follow.

  In addition, for example, when rotation disturbance enters three motor shafts at the same time and exceeds the limit value of the motor drive angle of each shaft, a tracking reset operation is required and the tracking of the satellite needs to be interrupted. there were.

  The present invention has been made to solve the above-described problems, and provides a satellite tracking antenna control device that can be used at a driving singularity near the zenith without any problem and can realize a wide directivity control range. With the goal. Another object of the present invention is to provide a satellite tracking antenna control device that can reduce the interruption of satellite tracking by controlling the motor drive angle of each axis so as not to exceed the limit value.

A satellite tracking antenna control apparatus according to the present invention is a satellite tracking antenna control apparatus that tracks the satellite by controlling the attitude of an antenna reflector that is mounted on a moving body, and has three axes that determine the attitude of the antenna reflector. On the other hand, an antenna driving unit that has four motor axes that are one-axis redundant and drives the antenna reflector, an inertia reference unit that outputs posture angle information and position information of the moving body, and a posture angular velocity of the moving body A rate gyro that outputs information; position information of the moving object output by the inertial reference unit; attitude estimation information of the moving object output from the attitude estimation filter; and a position of the satellite that is held based on the information, a difference between the direction of the direction and the satellite the current of the antenna reflector, the antenna coordinate system fixed to the moving body A satellite-direction calculation section for calculating a direction cosine matrix,
Based on the direction cosine matrix given as a satellite direction command as seen from the antenna coordinate system, the motor angle command for each axis one sample before and each motor axis so as not to exceed the motor angle limit maximum value and minimum value for each axis. A redundant axis control processing unit that simultaneously calculates a matrix of motor angle commands for each motor axis using an evaluation function that calculates the command of the motor, and the antenna drive based on the motor angle command for each motor axis calculated by the redundant axis control processing unit. And a drive control unit for controlling the unit.

  According to the present invention, it is possible to realize an effect that a wide directivity control range can be realized and interruption of satellite tracking can be reduced.

An embodiment of the present invention will be described below.
Embodiment 1 FIG.
1 is a side view showing the mechanism of a satellite tracking antenna control apparatus according to Embodiment 1 of the present invention. This satellite tracking antenna control device controls an antenna reflector 21 that is mounted on a moving body 11 such as a ship, a vehicle, or an aircraft and tracks a beam from a satellite. The inertial reference unit (IRU) 1, the rate gyro 2, arithmetic unit 3, drive control unit 4, antenna mount 13, azimuth (AZ) drive motor 14, cross elevation (xEL) arm 15, cross elevation (xEL) motor 16, elevation (EL) arm 17, elevator A polarization (POL) arm 18, a polarization (POL) arm 19, and a polarization (POL) motor 20.

  The antenna drive unit 12 includes an azimuth drive motor 14, a cross elevation arm 15, a cross elevation motor 16, an elevation arm 17, an elevation motor 18, a polarization arm 19, and a polarization motor 20. The antenna reflector 21 is driven with a redundant motor shaft with respect to the attitude of the reflector 21.

  The inertia reference unit 1 outputs roll, pitch, and yaw attitude angle information of the moving body 11 and position information of the moving body 11. The rate gyro 2 outputs roll, pitch, and yaw attitude angular velocity information of the moving body 11. The calculation unit 3 estimates the attitude of the moving body 11 based on the attitude angle information of the moving body 11 from the inertial reference unit 1 and the attitude angular velocity information of the moving body 11 from the rate gyro 2, and calculates the direction of the satellite to drive the antenna. The motor angle command of each motor shaft of the unit 12 is output. The drive control unit 4 controls each motor shaft of the azimuth drive motor 14, the cross elevation motor 16, the elevation motor 18, and the polarization motor 20 of the antenna drive unit 12 based on the motor angle command from the calculation unit 3. .

  The antenna mount 13 is attached to the moving body 11, the azimuth drive motor 14 is mounted on the antenna mount 13, the cross elevation arm 15 is attached to the motor shaft of the azimuth drive motor 14, and the cross elevation motor 16 is cross elevation. Attached to the arm 15, the elevation arm 17 is attached to the motor shaft of the cross elevation motor 16, the elevation motor 18 is attached to the elevation arm 17, and the polarization arm 19 is attached to the motor shaft of the elevation motor 18. The polarization motor 20 is attached to the polarization arm 19 and the antenna reflector 21.

FIG. 2 is a diagram showing the configuration of the motor of the antenna control device for tracking satellites, and reference numerals 14 to 21 correspond to FIG. In FIG. 2, x _A , y _A , and z _A are the antenna coordinate system A fixed to the moving body 11, and x _R , y _R , and z _R are the reflector coordinate system (antenna reflector coordinate system fixed to the antenna reflector 21. ) R. Further, q ₁ , q ₂ , q ₃ , and q ₄ indicate motor angle commands for the azimuth drive motor 14, the cross elevation motor 16, the elevation motor 18, and the polarization motor 20, respectively, and φ, θ, and ψ are The rotation angle of each axis in the reflector coordinate system R is shown.

FIG. 3 is a diagram showing a kinematic model of an antenna control device for satellite tracking. Reference numerals 14 to 21 correspond to FIG. 1, q ₁ , q ₂ , q ₃ , and q ₄ are motor angle commands, x _A , Y _A and z _A are the antenna coordinate system A, and x _R , y _R and z _R are the reflector coordinate system R. In addition, x ₁ , y ₁ , and z ₁ represent the azimuth drive motor coordinate system M ₁ fixed to the azimuth drive motor 14, and x ₂ , y ₂ , and z ₂ represent cross elevation fixed to the cross elevation motor 16. The motor coordinate system M ₂ is shown, x ₃ , y ₃ , and z ₃ show the elevation motor coordinate system M ₃ fixed to the elevation motor 18, and x ₄ , y ₄ , and z ₄ show the polarization motor 20. A fixed polarization motor coordinate system M ₄ is shown.

In FIG. 3, the rotation of the reflector coordinate system R about the z axis is the polarization motor coordinate system M ₄ , and the rotation of the polarization motor coordinate system M ₄ about the y axis is the elevation motor coordinate system M ₃ . , elevation motor coordinate system which the M ₃ is rotated in the x-axis cross elevation motor coordinate system M _2, and the cross elevation motor coordinate system M ₂ the azimuth drive motor coordinate system M ₁ becomes that rotates in the z-axis The azimuth drive motor coordinate system M ₁ and the antenna coordinate system A coincide with each other if they are in an ideal mounting state.

In FIG. 3, the azimuth drive motor coordinate system M ₁ rotated about the z-axis is the cross-elevation motor coordinate system M ₂ , and the cross-elevation motor coordinate system M ₂ rotated about the x-axis is the elevation motor. coordinate system M _3, and the elevation motor coordinate system M ₃ those rotating at y axis Polarization motor coordinate system M _4, and the Polarization motor coordinate system M ₄ is reflector coordinate system obtained by rotating the z axis R.

  FIG. 4 is a diagram showing a state in which the satellite tracking antenna control apparatus and the antenna reflector according to the first embodiment of the present invention track the satellite. Here, the satellite tracking antenna control device and the antenna reflector 21 track the satellite 22 which is a stationary satellite and perform communication.

  FIG. 5 is a block diagram showing a satellite tracking configuration of the satellite tracking antenna control apparatus according to the first embodiment of the present invention. This satellite tracking configuration includes an inertial reference unit (IRU) 1, a rate gyro 2, a calculation unit 3, and a drive control unit 4, and is the same as that shown in FIG. The calculation unit 3 includes an attitude estimation filter unit 33, a satellite direction calculation unit 36, and a redundant axis control processing unit 38.

The inertial reference unit (IRU) 1 determines the attitude angles (~) of the roll, pitch, and yaw of the mobile body 11 from the fluctuations (α, β, γ) applied to the roll, pitch, and yaw of the mobile body 11. (α, ~ β, ~ γ) is measured and the posture angle information 31 is output, and the latitude, longitude, and (altitude) position of the mobile object 11 are measured and the position information 35 of the mobile object 11 is output. The rate gyro 2 measures the three-axis posture angular velocity (˜ω _BX , ˜ω _BY , ˜ω _BZ ) of the roll, pitch, and yaw of the moving body 11 and outputs posture angular velocity information 32. The posture estimation filter unit 33 estimates the three-axis posture of the moving body 11 such as roll, pitch, and yaw based on the posture angle information 31 from the inertial reference unit (IRU) 1 and the posture angular velocity information 32 from the rate gyro 2. Then, posture estimation values (^ α, ^ β, ^ γ) are calculated and posture estimation information 34 is output.

The satellite direction calculation unit 36 holds the position information 35 of the moving body 11 output from the inertial reference unit (IRU) 1 and the attitude estimation information 34 of the moving body 11 output from the attitude estimation filter unit 33 and holds the satellite 22. The direction of the satellite 22 in the antenna coordinate system A is calculated on the basis of the position information, and the direction cosine matrix ΔΦ that is the difference between the current direction of the antenna reflector 21 and the direction of the satellite 22 in the antenna coordinate system A is calculated. Output as a matrix 37. Note that the position information of the satellite 22 which is a geostationary satellite is stored in a memory in several tables. The redundant axis control processing unit 38 uses the evaluation function related to the motor angle using the redundant motor axis based on the direction cosine matrix information 37 from the satellite direction calculation unit 36 and uses the motor angle of each motor axis of the antenna driving unit 12. The command (q ₁ , q ₂ , q ₃ , q ₄ ) 39 is calculated and output. The drive control unit 4 is based on the motor angle command 39 from the redundant axis control processing unit 38, and each motor shaft of the azimuth drive motor 14, the cross elevation motor 16, the elevation motor 18, and the polarization motor 20 of the antenna drive unit 12. Drive.

Next, the operation will be described.
The attitude of the antenna reflector 21 that tracks the beam of the satellite 22 is given by three angles: an azimuth angle, an elevation angle, and a polarization angle. Here, the azimuth angle, the elevation angle, and the polarization angle are directions of the satellite 22 as viewed from the antenna coordinate system A fixed to the moving body 11. On the other hand, in the first embodiment, there are four motors for driving the antenna reflector 21, the azimuth drive motor 14, the cross elevation motor 16, the elevation motor 18, and the polarization motor 20. It has a configuration having a motor shaft.

  As described above, the antenna drive unit 12 has a redundant motor shaft with respect to the azimuth angle, the elevation angle, and the polarization angle, which are the directions of the satellite 22 as viewed from the antenna coordinate system A. Even if the moving body 11 is rotated in the roll or pitch direction at a driving singularity such as the vicinity, it is not necessary to follow only by the azimuth driving motor 14, but as described later, it is wide by following other motors. A directional control range can be realized.

Here, in the kinematics model shown in FIG. 3, the motor angle command one sample before by the redundant axis control processing unit 38 of the azimuth drive motor 14, the cross elevation motor 16, the elevation motor 18, and the polarization motor 20. When q = [q ₁ , q ₂ , q ₃ , q ₄ ] ^T , the transformation of each coordinate system by the redundant axis control processing unit 38 is shown below.
First, conversion from the reflector coordinate system R to the polarization motor coordinate system M ₄ is expressed by the following equation (1).

The conversion from the polarization motor coordinate system M ₄ to the elevation motor coordinate system M ₃ is expressed by the following equation (2).

The conversion from the elevation motor coordinate system M ₃ to the cross elevation motor coordinate system M ₂ is expressed by the following equation (3).

The conversion from the cross elevation motor coordinate system M ₂ to the azimuth drive motor coordinate system M ₁ is expressed by the following equation (4).

Conversion from the azimuth drive motor coordinate system M ₁ to the antenna coordinate system A is expressed by the following equation (5).

Here, the Jacobian matrix used when the redundant axis control processing unit 38 obtains a motor target command speed and a motor angle command, which will be described later, is defined.
Assuming that the unit vector in the rotation direction of each motor in the M _j coordinate system is q _{i <Mj>} , the Jacobian matrix is expressed by the following equation (6) using q _{i <R>} .
_{J 1 = [q 1 <R} > q 2 <R> q 3 <R> q 4 <R>] (6)

Here, q _{4 <R>} , q _{3 <R>} , q _{2 <R>} , and q _{1 <R>} are shown in the following formulas (7) to (10), respectively.

The direction of the satellite 22 in the antenna coordinate system A is a direction cosine matrix Φ _CMD in the antenna coordinate system A. During control, the difference between the direction of the direction and the satellite 22 of the current antenna reflector 21 is very small, if this is, as shown in FIG. 2, it expressed in rotation angle of each axis of the reflector coordinate system R, x ₁ = [Φ, θ, ψ] ^T , the direction cosine matrix ΔΦ that is the difference between the current direction of the antenna reflector 21 and the direction of the satellite 22 in the antenna coordinate system A calculated by the satellite direction calculation unit 36 is the reflector coordinates. In the system R, it can be expressed as the following formula (11).

ここで、Ｉは単位行列を示す。 When J ₁ is a Jacobian matrix for q of x ₁ , J ₁ ⁺ is a pseudo inverse matrix of Jacobian matrix J ₁ , x _1d is a target for variable x ₁ , and k ₁ is an n-dimensional arbitrary constant vector, motor target command speed Is given by the following equation (12).

Here, I represents a unit matrix.

ここで、１サンプル前のモータ角度指令ｑ_dkは冗長軸制御処理部３８内に記憶されており、Ｊ₁ ⁺は１サンプル前のモータ角度指令ｑ_dkより計算される。 One sample before the motor angle command _{(q 1, q 2, q} 3, q 4) a q _dk, this motor angle command a _{(q 1, q 2, q} 3, q 4) q dk + 1, a Δt Assuming the sampling time, the redundant axis control processing unit 38 obtains the current motor angle command q _{dk + 1} by the following equation (13) using the above equation (12).

Here, the motor angle command q _dk one sample before is stored in the redundant axis control processing unit 38, and J ₁ ⁺ is calculated from the motor angle command q _dk one sample before.

The third term on the right side of the above equation (13) is a redundant term, and in order to use this, the evaluation function p related to the motor angle represented by the angle vector q (corresponding to the motor angle command one sample before) is kept as large as possible. Like that. The k _p is a positive constant, gives an evaluation function p from the following equation (14) as in equation (17).
p = V (q) (14)
k ₁ = ξk _p (15)
ξ = [ξ ₁ , ξ ₂ , ξ ₃ , ξ ₄ ] ^T (16)
ξ _i = ∂V (q) / ∂q _i (i = 1, 2, 3, 4) (17)
Here, ξ ₁ , ξ ₂ , ξ ₃ , and ξ ₄ are obtained by partial differentiation of the evaluation function = V (q) by the angle vector q _i (i = ₁ , ₂ , ₃ , ₄ ) as shown in the equation (17). Ξ is a vector expressing ξ ₁ , ξ ₂ , ξ ₃ , and ξ ₄ as shown in equation (16).

  This redundant term is due to the fact that the antenna reflector 21 is controlled by three motor axes with one axis redundancy while the attitude of the antenna reflector 21 is determined by three axes. When a motor approaches the limit value of the drive angle, the motor can no longer operate, but the redundant axis control processing unit 38 operates using an evaluation function related to the motor angle using the redundant motor axis. By appropriately controlling with the other three motors that can be used, the limit value of the drive angle of a certain motor can be compensated. In this way, by defining the evaluation function p, a standard for using redundant motor shafts is given.

ここで、ｋ_pは正の定数、ｆ_iは各モータの駆動角度に対する重みをあらわす定数、ｑ_iはモータの駆動角度値（モータ角度指令）である。また、ｑ_imaxはモータの駆動角度の制限最大値、ｑ_iminはモータの駆動角度の制限最小値、ｑ_imidはモータの駆動角度の制限中央値であり、それぞれ定数である。ｎ＝２，４，６，．．．は偶数で設定する。 The redundant axis control processing unit 38 controls other motors by using the evaluation function of the following equation (18) as the evaluation function p = V (q) for the motor having the limit value of the drive angle. Control can be performed so as not to exceed the limit value of the drive angle.

Here, k _p is a positive constant, f _i is a constant representing a weight for the driving angle of each motor, and q _i is a driving angle value (motor angle command) of the motor. Further, q _imax is limited to a maximum value of the driving angle of the motor, q _imin limit the minimum value of the driving angle of the motor, q _imid is limited median driving angle of the motor, respectively constant. n = 2, 4, 6,. . . Is an even number.

Here, a simulation is shown for a case where an antenna control device for satellite tracking and an antenna reflector 21 are mounted on a ship as an example of the mobile object 11 and shaken. _A coordinate system obtained by rotating a certain coordinate system Σ _A around the z _A axis by an angle α is Σ _A ′, a coordinate system obtained by rotating Σ _A ′ around the y _A ′ axis by an angle β is Σ _A ′, _A coordinate system obtained by rotating Σ _A '' around the x _A '' axis by an angle γ is Σ _A '''. Assuming that the rotation matrix between the coordinate system obtained by rotating around an axis W by an angle α is Φ (W, α), the roll angle α, pitch angle β, yaw angle calculated by the satellite direction calculation unit 36. A direction cosine matrix Φ _CMD indicating the direction of the satellite 22 in the antenna coordinate system A with respect to the fluctuation of γ can be expressed by the following equation (19).
Φ _CMD = Φ (z _A , γ) Φ (y _A ′, β) Φ (x _A ′ ′, α) (19)

FIG. 6 shows the angle of oscillation input for the ship roll (x axis), pitch (y axis), and yaw (z axis) when the satellite tracking antenna control device and antenna reflector 21 are mounted on the ship. FIG. As shown in FIG. 6, the satellite direction calculation unit 36 performs calculation when α, β, and γ are input to the rocking roll input (x axis), pitch (y axis), and yaw (z axis). The antenna direction cosine matrix Φ _CMD indicating the direction of the satellite 22 in the antenna coordinate system A is given by the matrix shown in the following equation (20).

The simulation when the ship is shaken according to the above equations (19) and (20) is as follows.
The rotation angle of each axis is expressed as λ = [α, β, γ], and when the roll (x axis) ± 30 deg / 8 sec, pitch (y axis) 0 deg, yaw (z axis) ± 8 deg / 6 sec, It can be expressed by equation (21).
λ = [α, β, γ] = λ ₀ + λ ₁ = [α ₀ , β ₀ , γ ₀ ]
+ [30 sin2π (t−4) / 8,0,8sin2π (t−4) / 6] deg (21)
Here, λ ₀ is an initial angle, and λ _t is a rocking angle with respect to time t. The initial angle λ ₀ is set to the following two conditions.
λ ₀ = [α ₀ , β ₀ , γ ₀ ] = [0, 0, 0] deg
λ ₀ = [α ₀ , β ₀ , γ ₀ ] = [ ₀ , 30, 30] deg

As the drive angle limit value of each motor shaft, the azimuth motor is −270 deg ≦ q ₁ ≦ 270 deg, the cross elevation motor is −35 deg ≦ q ₂ ≦ 35 deg, the elevation motor is −15 deg ≦ q ₃ ≦ 125 deg, polarization The motor is given by −120 deg ≦ q ₄ ≦ 120 deg. The control constants are sampling Δt = 0.001 sec, k _p = 3 × 10 ⁻⁵ , f ₁ = 0, f ₂ = 1000, f ₃ = 100, and f ₄ = 0.

  FIG. 7 is a diagram showing a simulation result of the drive angle of each motor when the ship is shaken under the above conditions. In FIG. 7 (a), the azimuth drive motor (AZ) 14, the cross elevation motor (xEL) 16, the elevation motor (EL) 18, near the zenith where the initial antenna direction is directly above, Each axis of the polarization motor (POL) 20 is well controlled. In FIG. 7B, the initial antenna direction is a result at a position of 30 deg from the zenith, and the control can be performed well within the motor angle limit. For example, in FIG. 7B, when the cross-elevation motor (xEL) 16 approaches the limit value of the drive angle around 5 seconds, the drive of the cross-elevation motor (xEL) 16 is suppressed. A drive motor (AZ) 14, an elevation motor (EL) 18, and a polarization motor (POL) 20 are driven.

  When there is no redundant axis, for example, when there is no motor shaft of the cross-elevation motor (xEL) 16, for example, when the direction of the satellite 22 is shaken in the roll direction near the zenith, the azimuth drive motor 14 is moved 180 degrees in a short time. Although it is necessary to rotate it close and a large torque is required instantaneously, it cannot be followed due to the limit of the torque performance of the azimuth drive motor 14. However, as described above, a wide directivity control range can be realized by following other motors.

  As described above, according to the first embodiment, the antenna driving unit 12 is redundant with respect to the azimuth angle, elevation angle, and polarization angle of the satellite 22 as viewed from the antenna coordinate system A fixed to the moving body 11. The redundant axis control processing unit 38 uses the evaluation function relating to the motor angle using the redundant motor axis based on the direction cosine matrix ΔΦ calculated by the satellite direction calculating unit 36. By calculating the motor angle command 39 of the shaft, it is possible to eliminate the deterioration of the pointing accuracy at the driving singularity such as near the zenith that has occurred in the three-axis driving without the redundant motor shaft, and the wide pointing control range The effect that can be realized is obtained.

  Further, according to the first embodiment, the redundant axis control processing unit 38 uses the evaluation function related to the motor angle using the redundant motor axis so as not to exceed the limit value of the motor driving angle of each axis. By controlling each motor shaft, it is possible to reduce the tracking interruption of the satellite 22.

Embodiment 2. FIG.
The diagram showing the mechanism of the satellite tracking antenna control apparatus according to the second embodiment of the present invention is the same as that of FIG. 1 of the first embodiment, and the block diagram showing the configuration of the satellite tracking is the diagram of the first embodiment. Same as 5.
FIG. 8 is a diagram showing limit value characteristics of the drive angle of the cross elevation motor with respect to the elevation angle of the satellite 22 in the satellite tracking antenna control apparatus according to the second embodiment of the present invention and the third embodiment described later.

  In FIG. 8, the ◯ marks indicate the characteristics in the case of the second embodiment, and the ▲ marks indicate the characteristics in the case of the third embodiment. The characteristics indicated by ◯ represent the limit value of the driving angle of the cross elevation motor 16 with respect to the elevation angle x of the satellite 22 as viewed from the antenna coordinate system A by switching between a quadratic function and a constant. This assumes a case in which the limit value of the drive angle of the cross elevation motor 16 is changed with respect to the elevation angle x of the satellite 22 due to, for example, interference of mechanical parts.

In the example indicated by a circle in FIG. 8, the limit value of the driving angle q ₂ of the cross elevation motor 16 used in the equation (18) of the first embodiment is expressed by the following equations (22) and (23). Give by switching.
_{q 2max, q 2min = ± (} -0.0253 (x-90) 2 +36) deg
(Abs (x−90) ≦ 55 deg) (22)
_{q 2max, q 2min = ± 5} deg
(Abs (x-90)> 55 deg) (23)

  FIG. 9 is a diagram showing a simulation result of the drive angle of each motor when the ship is shaken in the satellite tracking antenna control apparatus according to the second embodiment of the present invention. FIG. 9A shows a case where a swaying is given near the zenith, and FIG. 9B shows a case where a swaying is given at a position of 30 deg from the zenith. As shown in FIGS. 9A and 9B, it can be seen that both can be controlled well.

In the above example, the case where the limit value of the driving angle of the cross elevation motor 16 is changed by the elevation angle x of the satellite 22 has been described. However, the following equations (24) and (25) are applied to all motor shafts. It is also possible to set a limit value of the drive angle as shown in FIG.
q _imax , q _imin = ± (a _i (x−90) ² + b _i ) deg
(Abs (x−90) ≦ d _i deg) (24)
q _imax , q _imin = ± c _i deg
(Abs (x−90)> d _i deg) (25)
Here, a _i is a negative constant, b _i and c _i are positive constants, and d _i is the elevation angle of the satellite 22 for switching functions.

  As described above, according to the second embodiment, the redundant axis control processing unit 38 can be used even when the limit value of the driving angle of each motor changes with respect to the elevation angle x of the satellite 22. By appropriately using an evaluation function that uses redundant motor shafts, a wide directivity control range can be realized, and the tracking interruption of the satellite 22 can be reduced.

Embodiment 3 FIG.
The diagram showing the mechanism of the satellite tracking antenna control device according to the third embodiment of the present invention is the same as that of FIG. 1 of the first embodiment, and the block diagram showing the configuration of the satellite tracking is the diagram of the first embodiment. Same as 5.

In Figure 8 shown in the second embodiment, ▲ characteristics of mark represents the limit value of the driving angle of the cross elevation motor 16 against the angle of elevation x satellite 22 as viewed from the antenna coordinate system A in exp function Yes. As in the second embodiment, this is a case where the limit value of the driving angle of the cross-elevation motor 16 with respect to the elevation angle x of the satellite 22 is restricted due to, for example, interference of mechanical parts. Assumed.

In the example shown by the ▲ mark in FIG. 8, the limit value of the drive angle q ₂ of the cross elevation motor 16 used in the equation (18) of the first embodiment is given by the following equation (26).

  FIG. 10 is a diagram showing a simulation result of the drive angle of each motor when the ship is shaken in the satellite tracking antenna control apparatus according to the third embodiment of the present invention. As shown in FIG. 10A, when the initial antenna position is shaken near the zenith, it can be seen that the control can be satisfactorily performed so as not to exceed the limit value of the motor drive angle. Further, as shown in FIG. 10 (b), it can be seen that when the initial position is 30 deg from the zenith, the motor is controlled well so as not to exceed the limit value of the driving angle of the motor.

ここで、ａ_i，ｂ_iは正の定数である。 In the above example, the case where the limit value of the drive angle of the cross elevation motor 16 is changed by the elevation angle x of the satellite 22 has been shown, but the drive is performed as shown in the following equation (27) for all motor shafts. It is also possible to set an angle limit value.

Here, a _i and b _i are positive constants.

  As described above, according to the third embodiment, the redundant axis control processing unit 38 can be used even when the limit value of the driving angle of each motor changes with respect to the elevation angle x of the satellite 22. By appropriately using an evaluation function that uses redundant motor shafts, a wide directivity control range can be realized, and the tracking interruption of the satellite 22 can be reduced.

It is a side view of the mechanism of the antenna control apparatus for satellite tracking by Embodiment 1 of this invention. It is a figure which shows the structure of the motor of the antenna control apparatus for satellite tracking by Embodiment 1 of this invention. It is a figure which shows the kinematics model of the antenna control apparatus for satellite tracking by Embodiment 1 of this invention. It is a figure which shows a mode that the antenna control apparatus and antenna reflector for satellite tracking by Embodiment 1 of this invention track a satellite. It is a block diagram which shows the structure of the satellite tracking of the antenna control apparatus for satellite tracking by Embodiment 1 of this invention. It is a figure which shows the angle of the fluctuation | variation input about the roll of a ship, a pitch, and a yaw, when the antenna control apparatus and antenna reflector for satellite tracking by Embodiment 1 of this invention are mounted in a ship. It is a figure which shows the simulation result of the drive angle of each motor at the time of giving shake to a ship in the antenna control apparatus for satellite tracking by Embodiment 1 of this invention. In the satellite tracking antenna control apparatus according to the second and third embodiments of the present invention, it is a diagram illustrating a limit value characteristic of the driving angle of the cross elevation motor with respect to the elevation angle of the satellite. It is a figure which shows the simulation result of the drive angle of each motor at the time of giving a shake to a ship in the antenna control apparatus for satellite tracking by Embodiment 2 of this invention. It is a figure which shows the simulation result of the drive angle of each motor at the time of giving a shake to a ship in the antenna control apparatus for satellite tracking by Embodiment 3 of this invention.

  DESCRIPTION OF SYMBOLS 1 Inertial reference unit (IRU), 2 rate gyro, 3 calculating part, 4 drive control part, 11 mobile body, 12 antenna drive part, 13 antenna mount, 14 azimuth drive motor, 15 cross elevation arm, 16 cross elevation motor , 17 Elevation arm, 18 Elevation motor, 19 Polarization arm, 20 Polarization motor, 21 Antenna reflector, 22 Satellite, 31 Attitude angle information, 32 Attitude angular velocity information, 33 Attitude estimation filter section, 34 Attitude estimation information , 35 position information, 36 satellite direction calculation unit, 37 direction cosine matrix, 38 redundant axis control processing unit, 39 motor angle command.

Claims (8)

In the satellite control antenna control device for tracking the satellite by controlling the attitude of the antenna reflector mounted on the moving body,
An antenna drive unit for driving the antenna reflector having four motor axes that are one-axis redundant with respect to the three axes that determine the attitude of the antenna reflector;
An inertial reference unit that outputs posture angle information and position information of the moving body;
A rate gyro that outputs posture angular velocity information of the moving body;
A posture estimation filter unit that estimates the posture of the moving body based on posture angle information measured by the inertial reference unit and posture angular velocity information measured by the rate gyro and outputs posture estimation information of the moving body;
Based on the position information of the moving object output by the inertial reference unit, and the orientation estimate of the moving object outputted from the posture estimation filter unit, the position information of the satellites that holds, the current above A satellite direction calculation unit that calculates a difference between the direction of the antenna reflector and the direction of the satellite as a direction cosine matrix in an antenna coordinate system fixed to the moving body ;
Based on the direction cosine matrix given as a satellite direction command as seen from the antenna coordinate system, the motor angle command for each axis one sample before and each motor axis so as not to exceed the motor angle limit maximum value and minimum value for each axis. A redundant axis control processing unit that simultaneously calculates a matrix of motor angle commands of each motor axis by an evaluation function that calculates the command of
An antenna control device for satellite tracking, comprising: a drive control unit that controls the antenna drive unit based on a motor angle command of each motor axis calculated by the redundant axis control processing unit. The satellite drive unit for satellite tracking according to claim 1, wherein the antenna drive unit has four motor shafts by an azimuth drive motor, a cross elevation motor, an elevation motor, and a polarization motor. Antenna control device.   2. The satellite tracking antenna control device according to claim 1, wherein the limit value of the driving angle of each motor shaft of the antenna driving unit changes with respect to the elevation angle of the satellite. The redundant axis control processing unit sets x ₁ = [φ, θ, ψ] ^T when the difference between the direction of the antenna reflector and the direction of the satellite is expressed by the rotation angle of each axis in the coordinate system of the antenna reflector. when one sample before the motor angle reference, the Jacobian matrix relates angle vector q of the x _1, using the evaluation function for the motor angle, according to claim 1, characterized in that for calculating the motor angle command of each motor shaft Antenna control device for satellite tracking. The redundant axis control processing unit samples q _dk as the motor angle command one sample before, J ₁ is the Jacobian matrix for the angle vector q of x ₁ , J ₁ ⁺ is the pseudo inverse matrix of J ₁ , I is the unit matrix, and Δt is sampled _5. The satellite tracking according to claim 4, wherein a motor angle command q _{dk + 1} of each motor shaft is calculated by the following formula, where time, p is an evaluation function relating to motor angle, and k _p is a positive constant. Antenna control device.

p = V (q)
k ₁ = ξk _p
ξ = [ξ ₁ , ξ ₂ , ξ ₃ , ξ ₄ ] ^T
ξ _i = ∂V (q) / ∂q _i (i = 1, 2, 3, 4) The redundant axis control processing unit is a constant representing f _i , q _i is a motor angle value, q _imax is a motor angle limit maximum value, q _imin is a motor angle limit minimum value, q _imid is a motor angle limit median value, n 6. The satellite tracking antenna control device according to claim 5, wherein an evaluation function of the following formula is used as the evaluation function p regarding the motor angle when.

When the redundant axis control processing unit uses the evaluation function, a _i is a negative constant, b _i and c _i are positive constants, and d _i is an elevation of the satellite as viewed from the antenna coordinate system fixed to the moving object. The angle limit value of the i-th motor of the following equation that switches to a quadratic function and a constant with respect to the elevation angle of the satellite is used as the angle of the satellite. Antenna control device.
q _imax , q _imin = ± (a _i (x−90) ² + b _i ) deg
(Abs (x−90) ≦ d _i deg)
q _imax , q _imin = ± c _i deg
(Abs (x-90)> d _i deg) When the ai and bi are positive constants when using the evaluation function, the redundant axis control processing unit uses the following exp function for the satellite elevation angle as seen from the antenna coordinate system fixed to the moving body: 7. The satellite tracking antenna control device according to claim 6, wherein the angle limit value of the i-th motor in the equation is used.

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