JPS62274801A - Three-axis control antenna system - Google Patents

Abstract

PURPOSE:To set the maximum turning angular velocity around an orthogonal elevating axis smaller than the eye line angular velocity of a satellite by selecting the turnable range of a three-axis control antenna system around the elevating axis to be nearly 180 deg.. CONSTITUTION:The titled system is provided with an azimuth swing base 2 turned around an azimuth axis 3 fixed vertically, an elevating turning base 4 turnable around an elevating axis provided horizontally on the swing base 2 by nearly 180 deg. and a directivity antenna 6 fiftted to be turned within an angle limited around an orthogonal elevating axis 7 orthogonal to the axis 5 to the turning base 4. A satellite passing by a zenith having a predetermined elevating angle or over is traced by applying the turning around the elevating axis 5 continuously in excess of the elevating angle of 90 deg.. Thus, the antenna is turned by nearly 180 deg. in excess of the elevating angle 90 deg. around the elevating axis so as to limit the maximum turning angular velocity around the orthogonal elevating axis 7 to the eye line angle or below.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a 3@ control antenna device, and in particular, it is equipped with three axes: an azimuth axis, an elevation axis 41+, and an orthogonal elevation axis. The present invention relates to a three-axis control antenna device that can easily track a passing Nakajima satellite.

[Conventional technology]

Among the methods for supporting an all-sky directional antenna, a horizontal elevation axis (Ei axis) is provided on an azimuth swivel table that can rotate around a vertically fixed azimuth axis (Az axis). The Az-El mount system, in which the antenna is mounted on the mount so that it can rotate from the horizontal to the zenith, is the most structurally advantageous and is widely used. However, this method has a drawback in that when tracking all satellites passing near the zenith, the N rotation angular velocity per azimuth axis becomes very large.

On the other hand, there is a fixed axis (X-axis) fixed horizontally, and an Iij moving axis (
An X-Y mount with a Y-axis) has no problem in tracking satellites passing near the zenith, but it has difficulties in tracking satellites at low elevation angles, and the support structure is large. Ki l
It is unsuitable for large antennas.

One way to solve the above problem is to provide a 3-axis control antenna with an orthogonal elevation axis perpendicular to the elevation axis on the Ax-El mount, and the antenna can be rotated within a limited range around this orthogonal elevation axis. 9. A drive control method capable of reducing the rotatable range of the orthogonal elevation shaft rotor is proposed in Japanese Patent Laid-Open No. 60-22803. In this method, when tracking all satellites passing near the zenith, by driving the antenna in advance around the azimuth axis before the satellite reaches its maximum elevation angle, the antenna can be moved around the orthogonal elevation axis more easily than when no advance drive is performed. Choose something that can limit the rotatable range of the wheel to less than half.

[Problem that the invention seeks to solve]

However, even with the drive control method described above, there remains the problem that the maximum rotational angular velocity required for the rotation of the orthogonal elevation axis is greater than or equal to the line-of-sight angular velocity when looking at the satellite from the antenna, as will be described in detail later. has been done.

The object of the present invention is to rotate the antenna around the vertical axis by a vertical angle of 90°.
(In this specification, the angle of rotation per 1 axis of elevation is used as the angle of elevation to distinguish it from the normal angle of elevation, and when the rotation angle of the orthogonal axis of elevation is O, the antenna points toward the zenith. The state is approximately 180° beyond the elevation angle of 90.
An object of the present invention is to provide a complete three-axis control antenna device that can rotate up to 300 degrees and can limit the maximum rotational angular velocity of the above-mentioned orthogonal elevation and elevation axes rotation to below the line-of-sight angular velocity.

[Means for solving problems]

The three-axis control antenna device of the present invention includes an azimuth swivel base that can rotate around a vertically fixed azimuth axis, and an elevation axis that is horizontally provided on the azimuth swivel base and rotates approximately 180 degrees.
It is equipped with a rotatable elevating and elevating rotating pedestal, and a directional antenna attached to the elevating and elevating rotating mount so that it can rotate within a limited angular range around an orthogonal elevating and elevating axis that is orthogonal to the elevating and elevating axis. A satellite passing through the zenith region with a certain elevation angle or more will rotate around the elevation axis with an elevation angle of 9.
It is configured to continuously move and track beyond 0 degrees.

[Effect]

Next, the present invention will be explained in detail with reference to the drawings.

FIGS. 1(a) and 1(b) are vector diagrams showing changes in the rotation angle around the orthogonal elevation axis for a satellite passing near the zenith. Figure 1 (a) shows the case of tracking a satellite passing through the zenith from an azimuth angle of 0° to a direction of 180° at a line-of-sight angular velocity of 1.56/w. The black circles in the figure indicate the satellite's position every second. It shows. This satellite was installed using a conventional three-axis control antenna device with a movable range of elevation angle of up to about 90 degrees.
When tracking using the advance drive method described in Publication No. 0-22803, the maximum angular velocity is set on the azimuth axis from 9 seconds before the satellite reaches the zenith, so that the azimuth angle is 90 when the satellite reaches the zenith. Tracking is performed by advance driving at lO°/=, and the trajectory of the antenna azimuth and elevation angle at this time becomes a broken line, and the rotation angle about the orthogonal elevation axis 9 is shown by the length of the arrow vector. From this, it can be seen that when the satellite passes the zenith, it needs to be rotated around the orthogonal elevation axis 9 at the same speed as the line-of-sight angular velocity.

On the other hand, when tracking the same satellite group with the 3-axis control antenna device of the present invention, which can rotate the elevation axis by 180 degrees, the azimuth angle is fixed at θ° and the elevation angle is fixed at θ°. It is only necessary to rotate it beyond the angle 90, and tracking can be performed without rotating around the azimuth axis and the orthogonal elevation axis.

Figure 1(b) is an example of tracking a satellite passing through a maximum elevation angle of 87° in a direction with an azimuth angle of 90° using the three-axis control antenna device of the present invention. Normal tracking is performed using the azimuth axis and the elevation axis, and the azimuth angle is l.
When the satellite position reaches the maximum elevation angle, the azimuth angle is fixed and tracking is performed using the elevation axis and the orthogonal elevation axis, and the maximum angular velocity is set around the azimuth axis for 4 seconds from 2 seconds before the satellite position reaches the maximum elevation angle to 2 seconds after the satellite position reaches the maximum elevation angle. l of
The case is shown in which the azimuth angle is rotated in the negative direction by 5°/511C, which corresponds to /2, and when the azimuth angle reaches 110', the azimuth angle is fixed again and tracking is performed. As is clear from this figure, the rotation angle of the orthogonal elevation axis gradually increases, and once the satellite passes through the maximum elevation angle, it gradually decreases again. Therefore, it can be seen that the rotational angular velocity about the orthogonal elevation axis 9 may be smaller than the radial angular velocity of the satellite. Note that if the rotation angle of the orthogonal elevation and elevation angle rotation is tilted from the time of acquiring the satellite, the rotation angle may change even more slowly, and tracking can be performed mainly by rotation of the elevation and elevation axis rotation.

According to the above explanation, by setting the rotatable range of the 3-axis control antenna device around the elevation axis 9 to t'JtY180°, the maximum rotational angular velocity of the orthogonal elevation axis rotation is set to be smaller than the line-of-sight angular velocity of the satellite. It is clear that it can be done.

〔Example〕

FIG. 2 (al and (b)) shows the elevation angle θ of an embodiment of the present invention.
.

FIG. 2 is a side view of the vehicle at an angle of elevation of 90°, and a front view of the vehicle at an elevation angle of 90°. In Fig. 1 ta+ and (b), l is a support tower fixed on the ground, and 2 is a vertical azimuth axis 3 supported by the support tower l.
A 4ti azimuth swivel base with ±270° rotation
An elevation/rotation mount 4 that can rotate an elevation axis 5 horizontally on the azimuth swivel base 2 by 180°Ig1 and can direct the antenna in a horizontal direction opposite to the horizontal direction. The antenna is mounted so as to be rotatable by ±58 on the orthogonal elevation axis 7 which is provided above the elevation axis 5 and perpendicular to the elevation axis 5. Azimuth rotation and elevation rotation are performed via a large gear 8 fixed to the support tower 1 and a semicircular large gear 9 attached to the elevation rotation frame 4, respectively, but rotation of the orthogonal elevation axis 1 is performed in a straight line. Screwjacket that expands and contracts at the top 1
It is executed by 0.

Assuming that the maximum angular velocity of azimuth rotation is 10°/lec and the maximum angular velocity of elevation rotation is 5°/lec, for a satellite with a line-of-sight angular velocity of 1.5°/2, if the maximum elevation angle is about 80 or less, the normal Similar to the case of the Az-E L mount, tracking can be performed without rotation around the orthogonal elevation axis. On the other hand, as mentioned above, for satellites whose maximum elevation angle exceeds 85°,
-Tsoo's elevation and rotation can be tracked, 80~
If the tracking method described in the above-mentioned Japanese Patent Application Laid-Open No. 60-22803 is adopted for an 85° satellite, the maximum rotational angular velocity of the orthogonal elevation axis rotation is 0.8°/cut, which is about half of the line-of-sight angular velocity, which is sufficient for tracking. (In Figure 1, it is easy to see the position of a satellite passing at a maximum elevation angle of 85\r, one second before passing the maximum elevation angle.) In addition, there are great advantages in terms of disaster design and drive device design.

The above embodiment shows a case where the azimuth swivel table is attached to a support tower fixed on the ground via a bearing, but the azimuth swivel
It is also possible to have a trapezoidal frame structure installed with all wheels on a circular rail laid on the ground. In addition, the rotatable range around the orthogonal elevation axis is set to ±5°, and the
Although an example is shown in which the advance drive method described in JP-A No. 22803 is adopted, there is no problem even if the rotatable range is set to ±10° and the advance drive method is not used in combination.

〔Effect of the invention〕

As explained in detail above, the three-axis control antenna device of the present invention has the effect of limiting the rotational range of the orthogonal elevation axis rotation and setting the rotational angular velocity lower than the line-of-sight angular velocity of the satellite. Yes, this is a problem due to the design of the structure and drive device.

[Brief explanation of drawings]

Figures 1 (a) and (bl) are vector diagrams showing changes in the rotation angle of the orthogonal elevation 4141 eagle when tracking a satellite passing near the zenith; Example-9 = A side view and a front view of the example. l...Support tower, 2...Azimuth swivel table, 3
...Azimuth axis, 4...Elevation rotation mount, ...Elevation axis, 6...Antenna, 7...
... Orthogonal elevation axis, 8.9 ... Large gear, IO.
...Screwjack guy. =lO−

Claims (1)

[Claims] An azimuth swivel base that can rotate around a vertically fixed azimuth axis, an elevation rotation mount that can rotate approximately 180° around an elevation axis provided horizontally on the azimuth swivel base, and the above-mentioned elevation rotation mount. A satellite is equipped with a directional antenna mounted so as to be able to rotate within a limited angular range around an orthogonal elevation axis that is orthogonal to the elevation axis, and a satellite passing through a zenith region having a predetermined elevation angle or more is A three-axis control antenna device characterized by tracking by continuously rotating around an axis at an elevation angle exceeding 90°.