JPH02299301A - Antenna system for tracing geostationary satellite - Google Patents

Abstract

PURPOSE:To attain sure reception and transmission with a geostationary satellite by comparing a position signal representing a present position of an antenna with a peak value signal representing the position with the strongest radio wave receiving thereat and driving the antenna so as to make the discrepancy zero. CONSTITUTION:When an antenna 8 is directed toward a geostationary satellite, a changeover switch 26 is switched to the position shown in solid lines in figure so as to control the attitude of the antenna 8 depending on the strength of the radio wave sent from the geostationary satellite. A giro sensor 30 measures the displacement speed of the antenna 8 in this state and an integration device 31 sends a position signal thetaf representing the present position of the antenna 8. The signal thetaf is sent to a comparator 27 and sent to a 2nd object setting device 32, where a peak value signal thetap representing a position with a strongest radio wave is obtained. The comparator 27 compares both the signals thetaf, thetap to obtain its difference being an error signal theta, which is sent to a drive signal generator 33. The generator 33 drives the antenna 8 with a driver 28 so that the signal theta is zero, in other words, the direction of the antenna 8 is thetap.

Description

[Detailed Description of the Invention] (Industrial Application Field) The geostationary satellite tracking antenna device according to the present invention
It is installed in a radio vehicle that is dispatched in the event of a disaster such as a typhoon and makes various communications using geostationary satellites in the sky, and is used to control the attitude of this antenna so that it always faces the geostationary satellite.

(Prior technology) Radio is used as a means of communication between the site and the emergency response headquarters in the event of a disaster such as an earthquake or typhoon, but in recent years, radio waves have been used to communicate far away using geostationary satellites launched into the sky. It is becoming increasingly common to enable clear communication between distant locations.

When performing wireless communication using such a geostationary satellite, it is necessary to correctly point an antenna (usually a parabolic antenna) toward a predetermined geostationary satellite. If anything,
Currently, there are many geostationary satellites being launched into the sky, and even if the direction of the antenna shifts slightly (about 5 degrees), the antenna will point to the geostationary satellite next to the one it should originally be facing. This is because wireless communication using geostationary satellites cannot be performed.

As a stationary star tracking antenna device to be used in such cases, the present inventor previously developed a geostationary satellite tracking antenna device as described in Japanese Patent Application Laid-open Nos. 63-197104 and 63-226101. proposed.

The geostationary satellite tracking antenna device according to the present invention is constructed, for example, as shown in FIGS. 3 to 7, and operates as shown in the flowchart of FIG. 8.

That is, the vertical support shaft 3 inserted into the inside of the support tube 2 provided on the upper part of the base 1 fixed on the roof of the radio vehicle, etc.
The radial bearing 4 and the thrust bearing 5 allow for free rotation in the torsional direction.

By connecting the middle part of the antenna support frame 7 to the upper end of the vertical support shaft 3, for example, via a universal joint 6 as shown in FIG. It is supported so that it can swing freely.

The antenna 8 is fixed to the upper side of one end of the antenna support frame 7, which is swingably supported on the upper end of the vertical support shaft 3 in this way.
As the antenna support frame 7 swings, the direction of the antenna 8 can be freely changed.

By fixing a balance weight 10.10 to the support arm 9 provided at the lower side of the antenna support frame 7, an antenna support is provided in which various parts such as the antenna 8, balance weight 10.10, and a plurality of nozzles to be described later are fixed. The center of gravity of frame 7 is
The center of the universal joint 6 (as shown in FIG. 4, the center of the universal joint 6
If there are two rotation center axes 11.12 perpendicular to each other, then both rotation centers! li! The intersection of 11 and 12. ).

Further, at the tip of the support arm 13 that protrudes from the side of the middle part of the antenna support frame 7 as shown in FIGS. Fixed. The jet ports of the pair of upper and lower nozzles 14.15 that constitute this first nozzle set 16 are opened in opposite directions to each other, and by selectively jetting compressed air from either of the jet ports, this The antenna support frame 7 is configured to be rotated in a twisting direction about the rotation center axis 11 of the universal joint 6.

On the other hand, at the end of the antenna support frame 7 opposite to the antenna 8, as shown in FIG.
is fixed. Of these, the second nozzle set 17 includes a pair of upper and lower nozzles 19.2 whose jet ports are opened in the opposite direction.
0, and any nozzle 19 (or 2
By selectively injecting compressed air from the jet nozzle 0), the antenna support frame 7 is rotated in a direction in which it swings about the horizontal axis (rotation center f!tht 2 of the universal joint 6). ing.

The second nozzle set 1 is installed at the opposite end of the antenna support frame 7.
The third nozzle set 18, which is fixed in the same manner as Nozzle 7, is composed of nozzles 21 and 22 that open in opposite left and right directions, and compressed air can be selected from the ejection port of either nozzle 21 (or 22). By spraying the support frame 7 vertically, It is configured to rotate around i[i13.

Furthermore, the antenna support frame 7 has this antenna support frame 7.
In order to detect the direction of the antenna 8 fixed to one end, a detection means 23 having a built-in azimuth sensor and a vertical sensor is fixed. The orientation sensor detects the horizontal orientation of the antenna 8 (north, south, east, west, As this azimuth sensor capable of detecting the size, various conventionally known devices for detecting north, south, east, west, etc., such as an azimuth gyro or a geomagnetic azimuth sensor, can be employed.

Further, the vertical sensor detects the vertical direction of the antenna 8, so that when the elevation angle of the antenna 8 and the height position of the geostationary satellite deviate, the direction and magnitude of this deviation can be detected. . As this vertical sensor, various conventionally known devices such as an inclinometer, a vertical gyro for detecting the horizontal state of the antenna support frame 7, a spirit level, etc. can be employed.

Furthermore, a geostationary satellite is stationary approximately 36,000 km above the equator, and the direction of the geostationary satellite as seen from the radio vehicle varies depending on the position (longitude, latitude, altitude) of the radio vehicle (from several tens of kilometers to a hundred kilometers in the horizontal direction). In the case of a vehicle-mounted antenna, vertical deviation (altitude difference) cannot actually be a problem.
By controlling the direction of the antenna 8 based on the signal from the detection means 23 consisting of the azimuth sensor and the vertical sensor, practical communication can be performed.

That is, in the geostationary satellite tracking antenna device according to the earlier invention, the signal output from the detection means 23 consisting of the azimuth sensor and the vertical sensor is transmitted to the first to third nozzle sets 1.
Nozzles 14, which constitute 6 to 18,! 5. Solenoid valve provided in the middle of the compressed air flow path from 19 to 22 (in actual case, the solenoid valve is built in a part close to the injection port of each nozzle.

) is manually operated by a controller (not shown) that controls the opening and closing of the Based on the signal sent from the detection means 23, this controller opens a solenoid valve leading to a suitable nozzle among the six nozzles, injects compressed air from this nozzle, and generates a reaction of this ejection. The antenna support frame 7 is rotated or swung in an appropriate direction as shown in FIG.
The antenna 8 fixed at one end of the antenna always faces the geostationary satellite in the sky.

In the geostationary satellite tracking antenna device according to the prior invention configured as described above, when the wireless vehicle, etc. equipped with this antenna device travels, the running direction of the wireless vehicle, etc. changes, or Rolling and pitching occur as a result of driving on rough roads, but due to changes in the running direction, rolling, and pitching, the antenna support frame 7 with the antenna 8 fixed to one end
The orientation of the antenna 8 will not deviate from the stationary satellite due to a change in the direction of the satellite or rolling or pitching of the support frame 7.

That is, the vertical support shaft 3 supporting the antenna support frame 7 at its upper end is rotatable in the torsional direction, and the antenna support frame 7 attached to the upper end of the vertical support shaft 3 via the universal joint 6 The center of gravity is the center of the universal joint 6, that is, this universal joint 6
The antenna support frame 7 tends to maintain its posture unless an external force is applied, and the antenna support frame 7 including the antenna 8 and the balance weight 10 Since the inertial mass of the frame 7 is sufficiently large, 50 to 100 kg or more,
The tendency of the antenna support frame 7 to maintain the same position became noticeable, and the direction of the radio vehicle carrying the antenna device suddenly changed, or rolling or pitching occurred due to driving on rough roads. Even in this case, the antenna support frame 7 maintains its posture because of its large inertial mass.

Since the antenna support frame 7 maintains the same attitude even though the attitude of the radio vehicle etc. changes, the antenna support frame 7 and the radio vehicle are displaced relative to each other, but this displacement is caused by the vertical support shaft 3. This is compensated by rotation of the universal joint 6 or displacement of the universal joint 6.

As the relative displacement between the radio vehicle, etc. and the antenna support frame 7 is repeated many times, the rotational resistance of the radial bearing 4, thrust bearing 5, and universal joint 6 that support the vertical support shaft 3, as well as the conductor and compressed air supply. The force generated by the twisting of the feeding tube, as well as the wind hitting the antenna 8 and the antenna support frame 7 (in the illustrated example, the antenna 8 is covered by the windbreak plate 24, but there is a slight draft or wind that hits the antenna support frame 7). It is unavoidable that air flow occurs near the antenna support frame 7 due to convection generated inside the antenna support frame 7.) The antenna support frame 7 is displaced, and the direction of the antenna 8 supported by the antenna support frame 7 is changed. When the satellite deviates from the geostationary satellite, a difference occurs between the signal sent by the detection means 23 attached to the antenna support frame 7 to a controller (not shown) and the signal representing the position of the geostationary satellite stored in this controller in advance. .

When the controller receives a signal that deviates from the pre-stored signal, it determines the direction and magnitude of the deviation, and selects the first to third nozzle groups according to the direction and magnitude of the deviation. 16
A solenoid valve in the compressed air flow path leading to a suitable nozzle among the plurality of nozzles constituting the nozzles 18 to 18 is opened for an appropriate time depending on the magnitude of the deviation.

For example, if the angle of elevation of the antenna 8 becomes too small and the antenna 8 faces below the geostationary satellite, the controller will select the upper nozzle 19 of the two nozzles 19 and 20 that constitute the second nozzle set 17. A solenoid valve in the middle of the flow path leading to is opened, and compressed air is injected from this nozzle 19. This injection causes the antenna support frame 7 to rotate in the direction of arrow a in FIG. 3, and the angle of elevation of the antenna 8 increases.

Even if the antenna 8 is shifted in other directions, the three sets 6
Compressed air is ejected from one to three appropriate nozzles among the nozzles, swinging or rotating the antenna support frame 7,
Aim antenna 8 at the geostationary satellite.

As described above, the antenna 8 can be directed toward the geostationary satellite by the signal indicating the direction of the antenna 8 from the detection means 23, and it is possible to perform practically sufficient wireless communication using this geostationary satellite. I can do it.

(Problems to be Solved by the Invention) However, in the case of the geostationary satellite tracking antenna device according to the previous invention, which is configured and operates as described above, the following problems still exist to be solved.

That is, when the direction of the antenna 8 is controlled by the detection means 23 incorporating a gyro sensor, the direction of the antenna 8 determined by the detection means 23 (calculated value ) and the actual direction of the antenna 8 (actual value). Unless some kind of correction is made, this error will gradually accumulate, and the deviation between the calculated value and the actual value will gradually become larger.

As described above, as a result of the deviation between the calculated value and the actual value increasing over time, in the case of the antenna device for tracking a geostationary satellite according to the earlier invention, after a certain amount of time has passed, the direction of the geostationary satellite cannot be detected by the means for detecting the direction of the geostationary satellite. 23, and it was not possible to continue communication with the geostationary satellite without having to bother each other for a long time.

JP-A-63-197104 and JP-A-63-22610
No. 1 describes a means for directing the antenna 8 toward a geostationary satellite by changes in the strength of radio waves reaching the antenna from the geostationary satellite, regardless of the signal from the detection means 23, but these In the case of this method, it is necessary for the antenna 8 to continuously receive radio waves from the geostationary satellite.

That is, in the case of the means for directing the antenna 8 toward the geostationary satellite according to the previous invention, as long as the radio waves from the geostationary satellite continue to reach the antenna 8, the antenna 8 can continue to be correctly directed toward the geostationary satellite, but if the vehicle If radio waves from the geostationary satellite no longer reach the antenna 8 due to entering a tunnel or the shadow of a mountain, the attitude of the antenna 8 cannot be controlled.

In such a case, the attitude (orientation) of the antenna 8 is controlled by a detection means 23 incorporating a gyro sensor, and the control by this detection means 23 is made to be performed correctly even after a lapse of time. That is the present invention.

(Means for Solving the Problems) The geostationary satellite tracking antenna device of the present invention has a control mechanism configured as shown in the block diagram of FIG. As shown in FIG. 3, it is fixed to an antenna support frame 7, and this control mechanism controls the attitude of an antenna 8 that communicates with a geostationary satellite.

In the block diagram of FIG. 1, reference numeral 25 indicates a first target setting device that indicates the direction of the geostationary satellite. Indicates the direction. First goal setter 25
and a comparator 27, which will be described later, is switched to the state shown by the chain line when the geostationary satellite tracking antenna device starts to be used, and the setting signal from the first target setting device 25 is transferred to the comparator. Send it to 27.

28, by displacing the antenna support frame 7,
An antenna drive device that changes the direction of the antenna 8, for example, the first to third nozzle sets 16 shown in Fig. 3.5.6.7.
17.18. The antenna driving device 28 changes the direction of the antenna movement system 29, that is, the antenna support frame 7 and the antenna 8 fixed thereto (FIG. 3).

30 is a gyro sensor, and this gyro sensor 30 is
Detection means 23 (third
It detects the speed at which the direction of the antenna 8 changes. The speed signal θ9 detected by this gyro sensor 30 is sent to an integrator 31 connected to Dalian, and
The signal is sent to a drive signal generator 33, which will be described later.

The integrator 31 integrates the speed signal θ9 sent from the gyro sensor 30, that is, the displacement speed (speed and direction) of the antenna 8, and generates a position signal representing the position (direction at the present time) of the antenna 8. Or is output to the comparator 27.

Further, 32 is a second target setting device for indicating the direction of the geostationary satellite while the geostationary satellite tracking antenna device is in continuous use. The relationship between the strength of the radio wave reaching 8 and the antenna position determined by the integrator 31 is determined, and the position of the antenna 8 where the strength of the radio wave is the highest is output as a peak value signal θ.

That is, this second goal setter 32 is equipped with storage means.
is a signal E representing the reception sensitivity of radio waves from a geostationary satellite sent to the receiver 35 via the electric system 34 of the antenna 8, and the position (orientation) of the antenna 8 at that moment sent from the integrator 31. The peak value signal θ2 is determined from the relationship between the two signals E and θf. For example, as shown in Figure 2, multiple signals are plotted in a coordinate system in which the horizontal axis represents the signal θf representing the position of the antenna 8, and the vertical axis represents the signal E representing the reception sensitivity of radio waves from a geostationary satellite. The position signal of the antenna 8 at the time when the signal E representing the reception sensitivity of radio waves from the geostationary satellite, which is plotted on the vertical axis, becomes the highest is determined as the peak value signal θ2, and the changeover switch 26 is via comparator 27
send to.

The comparator 27 then compares the peak value signal θ sent from the second target setting device 32 with the position signal θt sent from the integrator 31 and representing the antenna position at that moment. , the difference between the two signals θ2,of and its direction are output as an error signal Δθ.

The error signal Δθ sent out from the comparator 27 in this way is
The drive signal generator 33 is manually inputted together with the speed signal θ9, and the drive signal generator 33 sends both signals in a direction (to eliminate the difference between the peak value signal θ and the position signal θ) based on θ9. A drive signal for changing the direction of the antenna in the direction in which Δθ becomes zero is determined, and this drive signal is sent to the drive device 28.

Furthermore, the second target setter 32 outputs a peak value signal θ,
When the size of reaches a certain level or more, perform coordinate transformation and set the peak value at that moment as the origin of the coordinates (
θ in Figure 2. θ.

At the same time, the integrator 31 is reset (the deviation between the direction of the geostationary satellite and the direction of the antenna is set to zero).

(Function) The function of the geostationary satellite tracking antenna device of the present invention configured as described above in keeping the antenna always directed toward the geostationary satellite is as follows.

When starting to use the geostationary satellite tracking antenna device, switch the changeover switch 26 to the state shown by the chain line in Figure 1, and turn on the signal θA indicating the direction of the geostationary satellite through a control panel (not shown) or the like. When input, the antenna 8 is directed toward the geostationary satellite based on this signal θ. The operation itself at the beginning of use is the same as that of the antenna device according to the previous invention described above, and there are no separate features.

When the antenna 8 is directed toward the geostationary satellite based on the signal θ6, the selector switch 26 is switched to the state shown by the solid line in FIG. antenna 8 so that it is input.
The attitude of the satellite will be controlled by the strength of the radio waves sent from the geostationary satellite.

In this state, the gyro sensor 30 constantly measures the displacement speed of the antenna 8 and sends a speed signal θ9 representing the result to the integrator 31. Therefore, the integrator 31 outputs a position signal Of representing the current position of the antenna 8. Send out constantly.

This position signal θf is sent directly to the comparator 27 and also to the second target setter 32, which determines the peak value signal θ representing the position where the radio waves are strongest. The peak value signal θ, represents the correct direction of the geostationary satellite at an approximate point in time.

The comparator 27 compares the two signals θf and θ2 to find the difference, and sends it to the drive signal generator 33 as an error signal 3 and 8. The antenna 8 is driven by the driving device 28 so that the angle becomes zero, in other words, the direction of the antenna 8 becomes 02.

As a result, the antenna 8 is correctly oriented toward the geostationary satellite, regardless of errors in the gyro sensor 30 caused by the earth's rotation, drift, and the like.

As a result of controlling the attitude of the antenna 8 in such a state, the value of the peak value signal θ2 gradually increases, and there is a risk that accurate control will not be possible.
2 is the peak value signal θ.

When the size of the integrator 31 reaches a certain level or more, coordinate transformation is performed to set the peak value at that moment as the origin of the coordinates, and at the same time, the integrator 31 is reset, so that the integrator 31 is reset after a long time. Even in this case, reliable operation is always performed, and the antenna 8 continues to face the geostationary satellite.

(Effects of the Invention) The antenna device for tracking a geostationary satellite of the present invention is configured and operates as described above, so that the transmission and reception of radio waves between the antenna and the geostationary satellite does not require human intervention even after a lapse of time. This can be done automatically and reliably.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the control part of the geostationary satellite tracking antenna device of the present invention, FIG. 2 is a diagram showing the state in which the peak value signal is obtained by the second target setter, and FIG. FIG. 4 is a schematic side view showing the mechanical device part of the antenna device, FIG. 4 is a perspective view showing an example of a universal joint that connects the vertical shaft and the support frame, and FIG. A section plan view,
Fig. 6 is a view of section A in Fig. 3 viewed from the side, Fig. 7 is a view of section B in Fig. 3 showing the second to third nozzle sets, viewed from the right, and Fig. 8 is a view of section A in Fig. 3 viewed from the right. It is a flowchart which shows the operation|movement at the time of attitude control of the antenna apparatus of a prior invention. 1: Base, 2: Support cylinder, 3: Vertical support shaft, 4 Niradial bearing, 5: Thrust bearing, 6 Universal joint, 7: Antenna support frame, 8: Antenna, 9: Support arm, 10: Balance weight, 11.12: Rotation center axis, 13: Support arm, 14
．． 15: nozzle, 16: first nozzle group, 17: second nozzle group, 18: third nozzle group, 19.20,21.
22: Nozzle, 23: Detection means, 24: Windbreak plate, 25:
First target setter, 26: changeover switch, 27: comparator, 28; antenna drive device, 29: antenna movement system, 30: gyro sensor, 31: integrator, 32: second target setter, 33; Drive signal generator, 34: Antenna electrical system, 35: Receiver.

Claims (1)

[Claims] (1) An antenna that is fixed to a support frame and communicates with a geostationary satellite, a first target setter that indicates the direction of the geostationary satellite, and a first target setter that directs the direction of the geostationary satellite.By displacing the support frame, the antenna direction can be adjusted. a gyro sensor that is fixed to the support frame and detects the speed at which the antenna changes direction; and a gyro sensor that integrates the speed signal sent from the gyro sensor and outputs a position signal that represents the position of the antenna. an integrator that determines the relationship between the strength of radio waves reaching the antenna from the geostationary satellite and the antenna position determined by the integrator, and outputs the antenna position where the strength of the radio waves is greatest as a peak value signal; A second target setter compares the peak value signal sent from the second target setter with the position signal representing the antenna position at that moment sent from the integrator, and compares both signals. a comparator that outputs the difference and its direction as an error signal, and a comparator that changes the direction of the antenna in a direction that eliminates the difference between the peak value signal and the position signal based on the error signal sent from this comparator. and a drive signal generator that obtains a drive signal and sends this drive signal to the drive device, and the second target setter performs coordinate transformation when the magnitude of the peak value signal reaches a certain level or more. An antenna device for tracking a geostationary satellite, which performs an operation of setting the peak value at that moment as the origin of coordinates and resetting the integrator at the same time.