JPS6214504A - Antenna directing device - Google Patents

Abstract

PURPOSE:To stabilize an antenna against the motion of a ship body around two axes orthogonal to each other and to make a system small-sized and low- cost by inputting the output of an elevation gyro having an input axis orthogonal to the antenna axis to an elevation servo and inputting the output of a bearing gyro to a bearing servo. CONSTITUTION:A bearing gimbals 40 is supported turnably around a perpendicular bearing shaft 10 on the base 3 of the system, and a fork part 40-1 having elevation shaft bearings 16 and 16' orthogonal to the shaft 10 is provided on the gimbals 40. Antenna attaching metallic fittings 41 are fitted turnably to bearings 16 and 16', and an antenna 14 having a bearing axis N and an elevation shaft X is attached to fittings 41. A bearing gyro 45, an elevation gyro 44, and the first and the second accelerometers 46 and 47 which have input axes parallel with or orthogonal to the axis N are attached to fittings 41. The output of the gyro 44 is fed back to an elevation servo motor 49 and the output of the gyro 45 is fed back to a bearing servo motor 52 to stabilize the antenna 14 against the motion of the ship body around two axes orthogonal to each other.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a device for directing an antenna toward a satellite, which is used in maritime satellite communications and the like.

[Conventional technology]

A conventional antenna directing device is configured as shown in FIG. 4, for example. That is, as shown in the figure, this pointing device consists of an antenna, a gimbal, etc., and is also called an antenna mount, and mainly consists of a mechanism section (1) installed on the ship and a control section (2) installed inside the ship. It consists of In the figure, (3) is a base, on which a support (3A) is erected, and a fork-shaped portion (3B) is attached to the upper end of the support. Roll shaft bearings (41,
(4') ((4') is not shown) is provided.

This base (3) is mounted on the hull. (5) is a roll gimbal, with a roll shaft (6) at a position corresponding to the roll shaft bearings (41, (4')).

(6') are fixedly installed, and these are the roll shaft bearings (6').
4) and (4') are rotatably fitted into each other. The roll gimbal (5) is connected to the roll axis (61, (6') and 9, respectively).
There are pitch shaft bearings (7+, (7')) at positions 0' apart, and pitch shafts +91. (9') fixed to these at the corresponding positions of the pitch gimbal (8) are rotatable, respectively. The pitch gimbal (8) is fitted to the bridge (8-1).
), and has a cylindrical part (10') projecting upward through the cylindrical part (10'), and the azimuth shaft bearings (9-1) and (9-1') are fixedly installed vertically apart from each other inside the cylindrical part (10').

(10) is an azimuth axis, which is rotatably fitted into the azimuth shaft bearings (9-1) and (9-1') in the cylindrical part (10'), and the azimuth gear ( 11), and a U-shaped member (12) is fixed to the upper end thereof. The U-shaped member (
12) has an elevation axis (1) at the same height as the roll axis (61, (6') or the pitch axis (9), (9').
3).

(13'). These elevational axes (13), (
13'), one end of which is rotated by the elevation shaft supports (16) and (16') provided at corresponding positions of the mounting members (15) and (15') to which the antenna (14) is attached, respectively. It fits perfectly.

(17) is a flywheel unit containing a flywheel that rotates at high speed around an axis parallel to the azimuth axis (10), and is fixed to the pitch gimbal (8).

By providing this flywheel unit (17),
The parts including the pitch gimbal (8), the U-shaped member (12), the antenna (14), etc. constitute a part of the gyro case, and the whole constitutes a gyro.

(18) is a pitch torquer, which is attached to the roll shaft bearing (4') of the fork-shaped part (3B) of the base (3), and when not in contact with the flywheel unit (17), Apply a torque proportional to its input current around the roll axis (61, (6')), resulting in a pinch gimbal (8) within the pitch axis (9).

A presetting effect is performed around (9').

(19) is a roll torquer, which is attached to the position of the pitch shaft bearing (7') of the pitch gimbal (5), and is attached to the pitch axis <9), (9) in a non-contact manner with respect to the flywheel unit (17). ') around the pitch gimbal (8), applying a torque proportional to its input current
(20) is a roll inclination needle which is attached to the pitch gimbal (8) and has the function of presetting the roll axis (6), (6') of the pitch gimbal (8) around the roll axis +61. (6') and its output is fed back to the roll torquer (19) through the amplifier (22), which moves the pitch gimbal (8) to the roll axis! 61, (6') Always keep it horizontal. (21) is a pitch tilt needle, which is mounted on the pitch gimbal (8) and detects the tilt around the pitch axis (9), (9') of the pitch gimbal (8), and its output is sent to the amplifier (23). is fed back to the pitch torquer (18) through the feedback loop, and the pinch gimbal (8) is always held horizontally around the pitch axis (91, (9'). In other words, by the feedback loop of 2 (11i1), the pitch gimbal (8) is always held horizontally, so that the azimuth axis (10) is always
It will be held vertically.

The azimuth angle of the U-shaped member (12) with respect to the pitch gimbal (8) is determined by an azimuth angle transmitter provided on the bridge (8-1) whose rotor (not shown) meshes with the azimuth gear (11). is detected by the device (24) and sent to the control unit (2). Also, the elevation angle of the antenna (14) with respect to the U-shaped member (12) is such that its rotor (not shown) is on one elevation axis (13).
) is detected by an elevation transmitter (26) provided on one of the mounting members (15) that meshes with an elevation gear (25) fixed to the motor, and simultaneously sent to the control unit (2). Control part (2)
, calculations are made based on the heading from a gyro compass (not shown), the azimuth angle of the satellite, the elevation angle, etc., and the azimuth servo motor (27) installed on the bridge (8-1) and the mounting member ( Elevation angle servo motor (28) installed in 15)
A command is given to the antenna (14) via amplifiers (27A) and (28A) to direct the antenna (14) in the desired satellite direction.

[Problem that the invention seeks to solve]

However, such a conventional antenna pointing device has two horizontal control systems for keeping the pitch gimbal horizontal around the roll and pitch axes, an azimuth control system for directing the antenna toward the satellite, and an antenna. Four elevation angle control systems are required to control the elevation angle of the plane, making the system expensive and reducing reliability. In addition, there is a pitch gimbal with a flywheel attached to the center, and around it are a roll gimbal, a fork-shaped part attached to a base with roll shaft bearings, a U-shaped member, etc., and a large gimbal on the outside. Since the antenna has a large diameter, the mechanical part becomes large, and there are various problems such as restrictions on installation locations and difficulty in equipment.

[Means for solving problems]

The present invention provides an antenna directing device including a base, a support mechanism, and an antenna, in which the support mechanism is rotatably supported around an azimuth axis perpendicular to the base, and the azimuth axis is mounted on an upper part. an azimuth gimbal constituted by a fork-like member having horizontal shaft bearings perpendicular to the horizontal shaft bearings; and an antenna support having a fixed horizontal shaft rotatably fitted to the horizontal shaft bearings and having an antenna axis perpendicular to the horizontal shaft. a first gyro fixed to the antenna support member and having an input axis parallel to the horizontal axis; and a first gyro fixed to the antenna support member and having an input axis perpendicular to both the antenna axis and the horizontal axis. a second gyro having a second gyro, an accelerometer fixed to the antenna support member and generating an output corresponding to the inclination of the antenna axis with respect to a horizontal plane, and transmitting a rotation angle of the azimuth gimbal about the azimuth axis with respect to the base. and an azimuth transmitter, and feeds back a signal obtained by subtracting a value corresponding to the altitude angle of the satellite from the output signal of the accelerometer to the substantial torquer of the first gear; This antenna directing device feeds a signal obtained by calculating an output signal, a signal corresponding to the ship's heading, and a satellite azimuth to the substantial torquer of the second gyro.

[Effect]

An elevation angle controller with an input axis orthogonal to the antenna axis.
The output of the gyro is input to the elevation servo motor, and the output of the azimuth gyro is input to the azimuth servo motor, respectively, to stabilize the antenna from the ship's motion around two axes perpendicular to the antenna axis. The satellite altitude angle is subtracted from the output of the accelerometer attached directly to the antenna so that the input axis is parallel to the antenna axis, and the result is fed back to the equivalent torquer of the gyro to match the antenna's elevation angle to the satellite altitude. The satellite azimuth and the bow azimuth from the gyro compass are added to and subtracted from the output of the azimuth transmitter that transmits the azimuth of the antenna relative to the hull, and the result is fed back to the equivalent torquer of the azimuth gyro to align the antenna with the satellite azimuth.

〔Example〕

FIG. 1 is a perspective view showing an embodiment of the antenna directing device of the present invention. In this figure, the same symbols as in FIG. 2 indicate the same elements.

In the example of the present invention shown in the figure, a blip part (3-1) is provided on the base (3), a cylindrical part (10') is planted on the blip part (3-1) so as to protrude upward, and the cylindrical part (10') is arranged inside the blip part (3-1). The orientation axis (1) is attached to the two orientation axis bearings (9-1) and (9-1').
0), and the azimuth gimbal (40) is rotatably supported around the axis of the azimuth axis (10) via the arm (40-1) at its upper end. A fork-shaped portion (40-2) is fixed to the upper end of the azimuth gimbal (40). This fork-shaped portion (40-2) has two elevation angle bearings (16), (
16'). Both legs (41-1) of the U-shaped mounting bracket (41) for attaching the antenna (14).

Elevation axis (13) installed at the corresponding position of (41-1')
.

(13') is rotatably fitted into the elevation shaft bearings (1B) and (16'), respectively. An elevation axis (13) is attached to this mounting bracket (41).

an elevation gyro (44) that detects the angle of the antenna (14) around (13') and an elevation axis (13), (
an azimuth gyro (45) for detecting the angle of the antenna (14) about an axis perpendicular to both the axis (X-X) of the antenna (13') and the axis (X-X) of the antenna (14); and the elevation axis (13) of the antenna (14). , (13') and a second accelerometer (47) to detect the tilt angle around the antenna axis (X-X) of the antenna (14), respectively. To be fixed.

The mounting bracket (41) also has an elevation gear (48) coaxial with one elevation axis (13). Azimuth gimbal (40)
A pinion (5
0) meshes with the elevation gear (48). on the other hand,
The azimuth gear (11) is attached to the lower end of the azimuth axis (1o), the azimuth servo motor (52) and the azimuth transmitter (53) are attached to the bridge part (3-1>) of the base (3), etc. A pinion (not shown) provided on the rotating shaft of the azimuth tooth N (
11) and engage each other.

FIG. 1 also shows a control loop when a differential type gyro such as a vibration gyro or a rate gyro is used as the elevation gyro (44) and the azimuth gyro (45). The output of the elevation gyro (44) is passed through an integrator (54) and an amplifier (55).
) to the elevation servo motor (49), and the elevation axis (13), (
13') is kept at zero.

On the other hand, the output of the first accelerometer (46) is passed through an arcsine calculator (57), and after subtracting a signal corresponding to the satellite altitude angle θS by manual setting etc., the output is sent to an attenuator (56).
The signal is input to the integrator (54) through the integrator (54).

This loop has a time constant that makes the elevation angle θ of the antenna (14) match the satellite altitude angle θS, and the attenuator (5
6) can also be provided with an integral characteristic in order to compensate for drift fluctuations of the elevation gyro (44).

On the other hand, the output of the azimuth gyro (45) is sent to the integrator (58)
, through an amplifier (59) to the azimuth servo motor (52), which rotates the antenna (14) around an axis perpendicular to both the antenna axis (X-X) and the elevation axes (13), (13'). stabilize against angular motion. On the other hand, a direction transmitter (
After the heading φC from the magnetic compass or gyro compass and the satellite azimuth φS determined by manual setting are subtracted from the output of 53), the signal is input to the integrator (58) through the attenuator (60). This loop has a time constant to match the antenna orientation φ with the satellite orientation φS, and the attenuator (60) can also be provided with integral characteristics in order to compensate for drift fluctuations of the orientation gyro (45). . That is, in FIG. 1, attenuator (56).

The output end of (60) corresponds to the torquer of the integral type gyro.

The elevation gyro (44) and the azimuth gyro (45) may be a conventional mechanical gyro, a two-axis degree-of-freedom type gyro such as a tuned dry gyro (TDG), or a rate-integrating gyro whose output is not an angular velocity ( , when using gyros with angles, their pickup outputs are directly passed through the amplifier (55) without passing through the integrators (54), (58).

(59), attenuator (56), (
The output of 60) can be input to the torquer of the corresponding gyro, and is not limited to the gyro type.

Also, elevation and azimuth servo motors (49), (52
), but a direct drive type that does not require a gear system may be used instead, and step motors, pulse motors, etc. may also be used.
Of course it is possible.

Further, as the azimuth transmitter (53), a synchro electric machine is generally used, but any device with a similar function such as a potentiometer or an encoder can be used.

The level control system in Fig. 1 also includes an arcsine calculator (5
7) was used to linearize the inclination angle of the antenna axis (X-X) from a sine function, but the same function can be obtained by conversely performing a sine calculation on the satellite altitude angle θS.

Incidentally, methods such as a step trunk method have been put into practical use in which the antenna is correctly directed toward the satellite by utilizing changes in the sensitivity of the antenna, and it goes without saying that such a feedback loop can also be used in conjunction with the present invention.

Furthermore, the output of the second accelerometer (47) is sent to the level control system and azimuth control system via a signal path (not shown) to correct the influence of the hull tilt around the antenna axis (X-X). used for

〔Effect of the invention〕

The effects of the antenna directing device according to the present invention are as follows. The roll gimbal and pitch gimbal in conventional antenna pointing devices are no longer necessary, allowing for significant downsizing and cost reduction. Additionally, since the number of components such as gear systems, servo motors, angle transmitters, and amplifiers has been reduced by half, the reliability of the entire device can be improved. In addition, due to the miniaturization, the equipment space is small, and since the overall weight is reduced, the installation location does not require much strength, which greatly simplifies the equipment work.

In addition, since the azimuth gimbal and antenna are driven by a high-torque servo motor, it is possible to completely eliminate the influence of the rigidity of the coaxial cable, etc. that sends signals from the antenna, on reception performance.

In addition, a feedback loop using an accelerometer is provided for the elevation system, and a gyro compass feedback loop is provided for the azimuth system, making it possible to use low-cost, low-accuracy gyros such as rate gyros for the elevation gyro and azimuth gyro. .

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an example of the antenna directing device of the present invention, and FIG. 2 is a perspective view of a conventional antenna directing device. In the figure, (3) is the base, (10) is the azimuth axis, (11)
is the azimuth gear, (13) and (13') are the elevation axes, (
14) is the antenna, (40) is the azimuth gimbal, (40-
2) is the fork-shaped part, (41) is the mounting bracket, (44)
is the elevation gyro, (45) is the azimuth gyro, (46)
, (47) is the accelerometer, (48) is the elevation gear,
(49) is the elevation servo motor, (50) is the binion, (
52) is a direction servo motor, (53) is a direction transmitter, (
54). (58) is an integrator, (55) and (59) are amplifiers, and (56). (60) represents an attenuator, and (57) represents an arcsine calculator.

Claims (1)

[Claims] In an antenna directing device including a base, a support mechanism, and an antenna, the support mechanism is rotatably supported around an azimuth axis perpendicular to the base, and a horizontal an azimuth gimbal constituted by a fork-like member having shaft bearings; an antenna support member having a horizontal shaft fixed thereto that rotatably fits into the horizontal shaft bearing and having an antenna axis perpendicular to the horizontal shaft; a first gyro fixed to the antenna support member and having an input axis parallel to the horizontal axis; and a second gyro fixed to the antenna support member and having an input axis perpendicular to both the antenna axis and the horizontal axis. a gyro; an accelerometer that is fixed to the antenna support member and generates an output corresponding to the inclination of the antenna axis with respect to a horizontal plane; and an azimuth transmitter that transmits a rotation angle of the azimuth gimbal about the azimuth axis with respect to the base; A signal obtained by subtracting a value corresponding to the altitude angle of the satellite from the output signal of the accelerometer is fed back to the substantial torquer of the first gyro, and the output signal of the azimuth transmitter, the heading direction and An antenna pointing device characterized in that a signal obtained by calculating a signal corresponding to a satellite azimuth angle is fed back to a substantial torquer of the second gyro.