JPH07202544A - Antenna system - Google Patents

Abstract

PURPOSE:To quickly control an antenna with a high precision by using infrared ray to transmit the signal of an oscillating sensor attached in the direction, to which a radiation part is directed, on a horizontal face perpendicular to the AZ axis and transmitting and receiving noiseless signals. CONSTITUTION:This antenna system controls the turning direction (AZ direction) and the elevation direction (EL direction) and consists of a rotating antenna part, a high frequency part which controls it, etc. The antenna part consists of a radiation part 3, an elevation control part 4, a control circuit 5, and an oscillating sensor 6. The high frequency part consists of a header detector 7, a turning sensor 8, a turning control part 9, an antenna control circuit 10, an RF part 11, and a modem 12. The antenna part and the high frequency part are connected by a rotary joint 13 for connection between the radiation part 3 and the RF part 11 and a transmission part 15 using infrared rays. This constitution minimizes the mechanical contact part in the antenna part as the rotating part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna device mounted on a ship or the like that is subject to shaking and tracking a target geostationary satellite or the like.

2. Description of the Related Art An antenna mounted on a ship must always be aimed and tracked at a target geostationary satellite or the like regardless of the movement of the ship, the rotation in the bow direction, the rolling of the ship, the pitching, or the like. As a method for controlling the attitude of the antenna, there is a two-axis method.

The biaxial system will be described with reference to FIG. An Az axis 1 perpendicular to the pedestal of the ship is rotatably provided, and an El axis 2 is rotatably provided on the Az axis 1. The Az axis 1 is rotated to match the azimuth angle with respect to the geostationary satellite S with respect to the vertical direction, and the El axis 2 is rotated to direct the antenna (radiating portion) 3 to an elevation angle with respect to the geostationary satellite S from a horizontal plane. .

Then, the inclination (pitching) of the vessel in the bow direction on the plane of the vessel and the inclination (rolling) in the direction orthogonal thereto are respectively detected by two attitude sensors to calculate a correction angle, which corresponds to the shaking of the vessel. Then, by correcting the rotation angles of the Az axis 1 and the El axis 2 based on the result of this calculation, the antenna 3 is always directed in the direction of the geostationary satellite S regardless of fluctuations such as pitching and rolling of the ship.

In this way, the antenna 3 receives the radio wave from the geostationary satellite and outputs it to the receiving circuit (not shown). The antenna 3 also transmits the output of a transmission circuit (not shown) to the geostationary satellite S. As for this electrical coupling, a rotary joint is realized as shown in FIG. The rotary joint is composed of a coupling member for coupling with a transmission / reception circuit fixed to the antenna device body and a coaxial cable. The coaxial cable of the antenna device body and the coaxial cable of the rotating portion provided at the center of the rotating portion are electromagnetically coupled. The main body and the rotating body are coupled by a plurality of bearings, and the rotating portion has a structure of rotating around the antenna device main body. The rotating part is mounted with a radiating part and is electrically coupled by a connector into which a coaxial cable is inserted.

A motion sensor for detecting the motion of a ship is called AZ
The antenna 3 may be attached in the directivity direction on a horizontal plane perpendicular to the axis 1. In that case, the detection signal of the motion sensor and the control signal for rotating the El shaft 2 of the antenna 3 are transmitted from the antenna device main body to the antenna 3 by an electric wire. However, since there is a rotating part, the wire is twisted and broken. Therefore, a means for connecting the detection signal and the control signal with a slip ring is adopted.

[0006]

However, the contact portion of the slip ring is carbonized due to sparks or the like. for that reason,
The slip ring needs to be replaced. Further, since the contact portion is mechanical, a pulsating flow is applied to the detection signal and the control signal,
It causes noise.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide an antenna device having means for transmitting a detection signal and a control signal without passing through a mechanical portion.

[0008]

In order to solve the above problems, the antenna device of the present invention uses means for transmitting a signal using infrared rays. Specifically, the biaxial antenna device has the following configuration.

On a horizontal plane perpendicular to the AZ axis, mounted on the radiation direction of the radiation part, a motion sensor for detecting motion of the ship, a transmission part for transmitting the signal of the motion sensor using infrared rays, and a transmission part An antenna control circuit that calculates the AZ axis rotation angle from the value of the motion sensor and the elevation angle of the EL axis obtained by the above, and a turning control unit that rotates the AZ axis according to the value calculated by the antenna control circuit.

[0010]

According to the antenna device configured as described above,
Minimal mechanical contact and less frequent replacement of mechanical parts. Moreover, a signal without noise can be transmitted and received, and the antenna can be controlled accurately and quickly.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

First Embodiment (Structure) FIG. 1 is a block diagram showing the first embodiment. Since the antenna device tracks the geostationary satellite S, it controls the turning direction (AZ direction) and the elevation angle direction (EL direction). The antenna device is composed of a rotating antenna unit, a high frequency unit for controlling the antenna unit, and the like. The antenna section includes a radiation section 3 (antenna element), an elevation angle control section 4, a control circuit 5, and a motion sensor 6. The high frequency unit includes the header detector 7, the turning sensor 8, the turning control unit 9, the antenna control circuit 10, the RF unit 11, and the MOD.
It is composed of EM12.

The antenna section and the high frequency section are connected by a rotary joint 13 for the radiation section RF signal, a slip ring 14 for power supply, an elevation angle control signal and a detection signal of the motion sensor 6 by a transmission section 15 using infrared rays. To do. As a result, the mechanical contact part in the antenna part, which is the rotating part, is minimized.

(Description of Operation) The transmission section 15 is composed of a light emitter 15a made of an infrared light emitting diode and a light receiver 15b made of a photodiode. FIG. 2 shows an outline of transmission of detection signals by infrared rays. (A) is a block diagram on the light emitting side, (b) is a block diagram on the light receiving side, (c) is an output (modulation signal) of a detection signal on the light emitting side, (d) is a carrier wave of an oscillator,
(E) shows the output waveform of the infrared light emitting diode, (f) shows the input waveform of the light receiving side photodiode, and (g) shows the output waveform of the light receiving side comparator.

A case where the detection signal of the motion sensor 6 is transmitted to the antenna control circuit 10 will be described. On the light emitting side, the modulator 5a modulates the carrier wave (d) of the oscillator 5a with the detection signal (c) from the motion sensor 6. The modulated signal (e) is output via the driver 5c. Infrared light emitting diode 15
The a transmits the modulated signal (e) to the receiving side. On the receiving side, the photodiode 15b detects the infrared modulation signal (f). After the signal is amplified by the amplifier 10a, it is demodulated by the detector 10c through the BPF 10b (bandpass filter) having the same frequency as the carrier wave of the detection signal. The demodulated signal (f) is reproduced by the comparator 10d into a digital waveform (g).

The rotation control signal for the EL shaft 2 is transmitted from the antenna control circuit 10 to the control unit 5. A predetermined elevation angle is set based on the position information of the own ship from the navigation device (not shown). These transmissions are performed by a normal communication method. For example, the detection signal of the motion sensor 6 has a resolution of 0.
At 2 degrees / bit, the elevation angle switching signal is output at 2 bits.

FIG. 3 is a schematic diagram for explaining the detection signal transmission section 15 using infrared rays. The carrier frequency of infrared rays is 30 KHz to 60 KH, which is less affected by sunlight.
z. Further, in order to reliably transmit the infrared control signal, a cover 16 that reflects infrared light is attached.

[Second Embodiment] The configuration of the second embodiment will be described with reference to FIG. (A) is a conceptual diagram showing a schematic structure, and (b) is a block diagram showing a circuit configuration. The power supply charges the battery BT of the antenna unit using electromagnetic waves. The output of the oscillator 17 placed in the antenna device body is guided to the iron core 19 via the coil 18. Further, the antenna 21 is guided to the coil 21 placed around the upper surface of the turntable 20. The induction waveform generated at the output end of the coil 21 is charged in the battery BT by the rectifier 22, the capacitor C, the resistor R, and the diode D. The battery BT supplies power to the control circuit 5, the motion sensor 6, and the elevation angle control unit. The ground is the rotary joint 13
Bearing and turntable 20 for antenna
Connected via bearings.

[Explanation of Antenna Device] An elliptic beam pattern in which the elevation angle direction of the radiation beam of the radiation unit 3 is widened is set, and the elevation angle is set to a predetermined angle. By subjecting the AZ axis 1 to optimum rotation control based on the combined rolling, which is the component of the motion sensor roll or pitch that is orthogonal to the antenna direction, and the elevation angle of the set radiation part, rolling and pitching of ± 15 degrees is received. However, the geostationary satellite S does not deviate from the range of the elliptical beam pattern. In the range of elevation angle of about 18 degrees, the EL axis can be used with the axis fixed. Also,
For use in a wider area, the EL axis may be preset. Also, the speed of the EL axis at the time of switching may be slow in consideration of the moving speed of the ship, and a small output drive motor is sufficient. Therefore, the battery BT of the second embodiment can be of a small capacity.

A method of calculating the combined rolling will be described with reference to FIG. 5A is a frequency characteristic diagram of the motion sensor 6, and FIG. 5B is a functional block diagram showing processing of the motion sensor 6. The motion sensor 6 for detecting the motion of the ship is A
It is composed of a rate sensor 101 and a level sensor mounted on the horizontal plane perpendicular to the Z-axis 1 in the antenna pointing direction (FIG. 6). The rate sensor 101 and the level sensor detect a combined rolling angle DR that is a component of the roll or pitch perpendicular to the antenna direction. The antenna part and the high frequency part are installed at a high position apart from the center of gravity of the ship.
Therefore, the shaking detection error due to the lateral acceleration is removed, and the shaking with a fast cycle is detected. The rate sensor 101 takes charge of the fluctuation of the fast cycle, and the level sensor takes charge of the fluctuation of the slow cycle. Therefore, the sensor response is shown in FIG.
The frequency characteristics are as shown in (a).

The signals detected by the rate sensor 101 and the level sensor are A / D-converted by the antenna control circuit 10 and are combined through the signal processing shown in FIG. 5 (b). Due to the characteristics of the rate sensor 101, the output signal is
Although the C drift offset voltage is superimposed, it is removed by DC cut and high pass filter processing.

The elliptical beam pattern is realized as follows. The radiation unit 3 and the reflector are composed of the radiators of one row and four rows fixed to the reflector. The center of each radiator is arranged on a straight line perpendicular to the EL axis, and by radiating in-phase beams, it is possible to form an elliptical antenna pattern of 60 degrees in the EL direction and 20 degrees in the AZ direction. it can.

As shown in FIG. 6, as sensors for detecting the turning of the ship, there are a rate sensor 201 attached in the AZ-axis direction of the radiation part (antenna) 3 and a magnetic direction sensor. The rate sensor 201 detects the turning direction and the rotational angular velocity of the AZ axis 1. The magnetic sensor detects the azimuth angle of the antenna by geomagnetism.

[0024]

As described above, according to the antenna device of the present invention, infrared rays are used as the signal of the motion sensor which is mounted on the horizontal plane perpendicular to the AZ axis in the radiation direction, and which detects motion of the ship. A transmission unit for transmitting the data is provided. Therefore, a signal without noise can be transmitted and received, and the antenna can be controlled accurately and quickly. Further, since the mechanical contact portion is minimized, the frequency of exchanging mechanical parts can be reduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention.

FIG. 2 is a diagram showing an outline of transmission of a detection signal by infrared rays.

FIG. 3 is a schematic diagram for explaining a detection signal transmission unit 15 using infrared rays.

FIG. 4 is a block diagram showing a second embodiment of the present invention.

5A is a frequency characteristic diagram of the motion sensor, and FIG. 5B is a functional block diagram showing processing of the motion sensor.

FIG. 6 is a diagram showing a relationship between sensor sway directions.

FIG. 7 is a schematic diagram of a rotary joint showing an RF signal connection between a rotating unit and an antenna device main body.

FIG. 8 is a principle view showing a conventional AZ-EL type antenna device.

[Explanation of symbols]

1 ... AZ axis, 2 ... EL axis, 3 ... Radiating section, 4 ... Elevation angle control section, 5 ... Control section, 6 ... Motion sensor, 7 ... Header detector,
8 ... Rotation sensor, 9 ... Rotation control unit, 10 ... Antenna control circuit, 11 ... RF unit, 12 ... MODEM, 13 ... Rotary joint, 14 ... Slip ring, 15 ... Transmission unit.

Claims (1)

[Claims] 1. An antenna device comprising a radiator (3) mounted on a ship, an EL axis (2) for controlling rotation of the radiator, and an AZ axis (1), wherein a horizontal plane perpendicular to the AZ axis. In the above, a motion sensor (6) that is attached in the radiation direction, and detects a motion of the ship, a transmission unit (15) that transmits a signal of the motion sensor using infrared rays, and a transmission unit (15) An antenna control circuit (10) for calculating the AZ axis rotation angle from the obtained value of the motion sensor and the elevation angle of the EL axis, and a turning control section (9) for rotating the AZ axis according to the value calculated by the antenna control circuit. ) And an antenna device.