JPH05199027A - Rolling compensation antenna system - Google Patents

Abstract

PURPOSE:To provide the small sized rolling compensation antenna system immune to a reflected wave on a sea surface with excellent maintenance performance. CONSTITUTION:A tilt array antenna 56 long lengthwise is employed for the antenna. The antenna 56 is made closer to a support 58 by the tilt angle and a radome 42 is made small in size while keeping a lengthwise long shape immune to a reflection wave on the sea surface. A rolling sensor 60 sensing a rolling angle is arranged on an AZ frame and a control algorithm is simplified.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motion compensation antenna device mounted on a marine vehicle.

[0002]

2. Description of the Related Art Conventionally, various systems such as satellite communication and satellite broadcasting have been developed and implemented. In this type of system, in which the station is mounted on a mobile unit, the attitude of the antenna or the beam direction is controlled to capture a satellite.

4 and 5 show the structure of an antenna device according to a conventional example. Figure 4 of these figures
4A is a side view of the antenna device with the antenna facing downward, FIG. 4B is a rear surface when facing the zenith, FIG. 4C is a radome base upper surface, and FIG. 5 is a gimbal. The configuration of each part is shown.

In this conventional example, as an antenna,
An array antenna 10 in which a plurality of antenna elements are arranged and connected in a plane is used. The beam of the array antenna 10 is parallel to the normal to the aperture plane of the antenna 10. The array antenna 10 rotates about the EL axis by the rotation of an elevation angle (hereinafter, referred to as EL: Elevation) 14. That is, the EL motor 14 is connected to the EL shaft 12 via the belt 16 and the gear 18.

The EL shaft 12 is AZ (hereinafter, AZ: Azimut
It is attached to the frame 20 (referred to as h). The AZ frame 20 is rotated by the AZ motor 22 so that the AZ axis 24
Rotate around. A belt and a gear are used to connect the AZ motor 22 and the AZ shaft 24, similarly to the connection between the EL motor 14 and the EL shaft 12.

The AZ axis 24 is connected to a gimbal portion 26 having a structure as shown in FIG. AZ axis 24
Is connected to the Y-axis 28 at the gimbal portion 26, and is rotated around the Y-axis 28 by the Y-axis motor 30. Y
The shaft 28 is rotated around the X-axis 34 by the X-axis motor 32. As shown in FIGS. 5 and 4B, the X-axis 34 is fixed to a branch portion above the column 36. Post 36
Are attached to the radome base 40 by the column flanges 38.

The radome base 40 constitutes the bottom surface of the radome 42, and covers the antenna 10 and its peripheral structure together with the radome 42. This conventional apparatus is mounted on a marine moving body such as a ship, and the radome 42 and the like protect the antenna 10 and the like from weather and bad weather. The radome 42 is formed of a material, such as FRP, that is permeable to the satellite radio waves and has a certain strength.

The radome base 40 also has a hinge 46.
An access hatch 44 that can be opened and closed is provided. As shown in FIG. 4B, electronic devices such as a low noise amplifier (LNA) 48 that amplifies the reception output of the antenna 10 and a preamplifier (PA) 50 for transmission are provided around the antenna 10. It is arranged. The access hatch 44 is
It is a hatch for maintenance, inspection, etc. of the antenna 10 and its peripheral configuration, and requires a certain size because it is necessary to insert a hand or the like. The access hatch 44 is provided on the radome base 40 in order to facilitate maintenance and the like in the case of rain.

Reference numeral 52 is a cable hole for wiring, and 54 is a motion sensor unit for motion compensation described later.

As in this conventional example, the X-axis 3
4, Y-axis 28, AZ-axis 24, EL-axis 12 antenna 10
A mount that supports the antenna 10 and allows the antenna 10 to rotate about each axis is called an XY-AZ-EL mount. In the case of this mount, the satellite can be tracked / captured by rotating the antenna 10 exclusively around the AZ axis 24 and the EL axis 12, and moved by rotating the antenna 10 exclusively around the X axis 34 and the Y axis 28. It can compensate for body sway. The motion compensation is performed by the motion sensor unit 5
4 output. That is, the motion sensor unit 54 detects the motion of the mounted moving body and outputs a signal to a control unit (not shown), and the control unit drives the X-axis motor 32 and the Y-axis motor 30 in response to the signal to control the antenna. Control 10 postures.

Further, in this conventional example, the antenna 10 has a vertically long shape. This is to reduce the effect of multipath fading due to sea surface reflection. That is, in order to effectively reduce the influence of sea surface reflection, the antenna beam around the elevation axis may be narrowed down. For this purpose, a relatively large number of antenna elements may be arranged in the vertical direction of the antenna 10 to form a vertically long shape. Good.

[0012]

However, when the antenna has a vertically long shape, when the antenna is oriented at a low elevation angle and wobbling occurs, the lower portion of the antenna and the support column for supporting the antenna compete with each other. In order to avoid this competition, it is necessary to increase the distance between the antenna and the column, and therefore the radome becomes large. Further, in order to make the access hatch sufficiently large, it is necessary to widen the radome base, which also causes the radome to become large.

The present invention has been made to solve the above problems, and provides a vibration compensating antenna device which is less susceptible to the influence of sea surface reflection, allows the radome to be downsized, and has good maintainability. The purpose is to provide.

[0014]

In order to achieve such an object, the present invention configures an antenna as a tilt beam antenna in which the beam direction is deviated by a certain angle around the EL axis with respect to the normal to the aperture plane. However, the present invention is characterized by including an eccentric support column that eccentrically supports the antenna on the radome base.

Further, the second aspect is characterized in that the swing angle detecting means for detecting the swing of the moving body is arranged so as to rotate with the rotation of the antenna around the AZ axis.

[0016]

According to the present invention, even if the antenna is swayed in a state where the antenna is oriented at a low elevation angle, since the antenna is a tilt beam antenna, the angle formed between the antenna and the column is small during the sway. Therefore, the distance between the antenna and the column can be reduced, and the radome can be downsized even if the antenna is vertically long. Further, since the support is an eccentric support as a means for reducing the distance between the antenna and the support, an access hatch of a sufficient size can be provided in the radome base despite the downsizing of the radome.

By the way, in the structure for performing the motion compensation using the AZ axis and the EL axis like the AZ-EL mount, for example, a complicated motion of converting the detected motion angle into an angle around the AZ axis and an angle around the EL axis is complicated. Arithmetic is required. According to the second aspect of the present invention, the swing angle detecting means that rotates around the AZ axis together with the moving body is used, whereby complicated calculation is eliminated.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings. The same components as those of the conventional example shown in FIGS. 4 and 5 are designated by the same reference numerals and the description thereof will be omitted.

FIG. 1 shows the configuration of a motion compensation antenna apparatus according to the first embodiment of the present invention. This embodiment is characterized in that a tilt type array antenna 56 is used in place of the array antenna 10 and an eccentric support type support column 58 is used in place of the support column 36.

As shown in FIG. 2B, the tilt type array antenna 56 in this embodiment has a beam (tilt beam) directed downward by 18 ° with respect to the normal to the aperture plane. As shown in FIG. 2A, the antenna element 5
According to the vertically long 8 element array antenna 56 using 4 vertically × 2 horizontally, the phase difference of 70 ° is given to each stage, so that a gain of 15 dBi and a tilt are obtained as shown in FIG. An angle of 18 ° can be realized. The phase difference is given by a phase shifter (not shown).

This tilt beam makes it possible to bring the lower part of the antenna 56 close to the support column 58. For example, in the conventional example shown in FIG. 4, the antenna 10 has an elevation angle of 5 °.
When a swing of 25 ° is applied around the EL axis 12 while capturing the satellite of FIG.
As shown in (a), the direction is 5 ° −25 ° = −20 °. On the other hand, in the embodiment, when the antenna 56 captures a satellite with an elevation angle of 5 °, the antenna 56 moves around the EL axis 12.
When a 5 ° sway is applied, the normal to the aperture plane of the antenna 56 is oriented at 5 ° + 18 ° −25 ° = −2 °. Therefore, in this embodiment, competition between the lower portion of the antenna 56 and the support column 58 is unlikely to occur, and the antenna 56 can be arranged closer to the support column 58. As a result, the radome 42 can be downsized.

Further, in this embodiment, an eccentric support structure by the support column 58 is adopted as a means for bringing the support column 58 close to the antenna 56. That is, the support column 58 is not attached to the radome base 40 immediately below the gimbal portion 26, but the antenna 5 as shown in FIG.
It is attached eccentrically to the 6 side. Also, FIG.
As shown in (b), it is slightly eccentric to the side.

With such a structure, the access hatch 44 can be provided on the radome base 40 in a sufficient size even though the radome 42 is downsized. Therefore, the maintainability of the antenna 56 and its peripheral parts does not deteriorate.

FIG. 3 shows the configuration of a motion compensation antenna apparatus according to the second embodiment of the present invention. This embodiment is an AZ-EL mount, unlike the XY-AZ-EL mount of the first embodiment, and is different in that the motion sensor 60 is mounted on the AZ frame 20.

In the XY-AZ-EL mount as in the first embodiment, the motion compensation is performed exclusively by the rotational drive around the X axis 34 and the Y axis 28. On the other hand, in the AZ-EL mount as in the second embodiment, the motion compensation is performed in the AZ axis 2
4 and the EL shaft 12 are driven to rotate. In the second embodiment, as the motion sensor 60 is mounted on the AZ frame 20, the AZ axis motor 22 and the EL axis motor 1
The control algorithm of 4 is simplified. Since this point is the same as the prior application of the applicant of the present application: Japanese Patent Application No. 3-57070, description thereof will be omitted here.

In this embodiment, the motion sensor 60 is set to A
Although it is mounted on the Z frame 20, it is also possible to separately provide a rotary table on which a motion sensor is mounted (see Japanese Patent Application No. 3-57070).

[0027]

As described above, according to the present invention,
By using the tilt beam antenna as the antenna, the pillar and the antenna can be arranged close to each other while the antenna shape is vertically long, and it is possible to obtain a small vibration compensation type antenna device that is strong against sea surface reflection and small. further,
Since the eccentric support post is used as a means to place the antenna close to the support post, despite the downsizing of the radome, a sufficiently large access hatch can be installed on the radome base, facilitating maintenance and inspection in rainy weather. Can be maintained.

Further, according to the second aspect, since the motion detecting means is rotated about the AZ axis like the antenna, the control algorithm is simplified.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a motion compensation type antenna device according to a first embodiment of the present invention, FIG. 1 (a) is a side view showing a state where a lower part of an antenna is closest to a column, and FIG. ) Is a rear view when the antenna is directed toward the zenith, and FIG. 1C is a top view of the radome base.

2A and 2B are views for explaining a tilt-type array antenna used in this embodiment. FIG. 2A shows an element arrangement, FIG. 2B shows a tilt angle, and FIG. 2C shows an antenna pattern. It is a figure which respectively shows.

FIG. 3 is a diagram showing a configuration of a motion compensation type antenna device according to a second embodiment of the present invention, FIG. 3 (a) is a side view showing a state where a lower part of the antenna is closest to a column, and FIG. ) Is a rear view when the antenna is directed toward the zenith, and FIG. 3C is a top view of the radome base.

FIG. 4 is a diagram showing a configuration of a motion compensation type antenna device according to a conventional example, FIG. 4 (a) is a side view showing a state in which a lower part of an antenna is closest to a column, and FIG. 4 (b) shows an antenna. FIG. 4C is a top view of the radome base, which is a rear view when facing the zenith direction.

FIG. 5 is a top view showing a configuration of a gimbal portion.

[Explanation of symbols]

 12 elevation angle (EL) axis 14 EL axis motor 20 azimuth (AZ) frame 22 AZ axis motor 24 AZ axis 26 gimbal part 28 Y axis motor 30 Y axis 32 X axis motor 34 X axis 40 radome base 42 radome 44 access hatch 56 tilt Type array antenna 58 prop (supporting eccentricity) 60 motion sensor

Claims (2)

[Claims] 1. An antenna having a vertically long shape, which is rotatably supported around at least an azimuth axis and an elevation angle axis, a radome that covers at least an upper surface of the antenna, and a bottom surface of the radome to access the antenna and its peripheral components. A radome base that opens the access hatch, a motion detection means that detects the motion of the mounted marine vehicle, and an axis control that rotates at least one of the axes that support the antenna to compensate for the motion of the marine vehicle. And a eccentric support for eccentrically supporting the antenna on a radome base, wherein the antenna is a tilt beam antenna in which the beam direction is deviated by a certain angle around the elevation axis with respect to the normal to the aperture plane. An oscillation compensation type antenna device comprising: 2. The motion compensation antenna device according to claim 1, wherein the motion angle detection means is arranged so as to rotate with the rotation of the antenna around the azimuth axis.