JPH05232206A - Antenna control apparatus - Google Patents

Abstract

PURPOSE:To shorten the time required for repicking-up of a satellite by means of a mobile station in a moving-body satellite communication. CONSTITUTION:When radio waves from a satellite cannot be received due to the shadow of a building or the like, an antenna control device 3 for an antenna 1 for satellite communication use which is mounted on a moving body such as a vehicle or the like and which is provided with the tracking function of the satellite detects the azimuth of the moving body by means an angular- velocity sensor 4, directs the antenna 1 to the direction of the satellite and, at the same time, detects the velocity of the moving body by means of a velocity sensor 5. Then, the maximum continuation time, of a tracking operation, which has been detected by means of the angular-velocity sensor 4 is controlled by means of the velocity of the moving body. When the velocity of the moving body is comparatively slow, the maximum continuation time is made long. When a state that the radio waves cannot be received is continued for many hours even at a short distance such as a stop due to a traffic signal or the like, a tracking operation by means of the angular-velocity sensor 4 is continued.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for controlling an antenna mounted on a moving body such as a vehicle for tracking a communication satellite.
The present invention relates to an antenna control device capable of reacquiring a communication satellite in a short time even when a mobile body travels in an unreceivable section.

[0002]

2. Description of the Related Art Conventionally, this type of antenna control device has been searching for a satellite by driving the antenna at high speed after open loop tracking for a certain period of time.

[0003]

Such a conventional antenna control device, when traveling in an unreceivable section, passes through the section as if the vehicle was stopped by a signal even if the section is a short section. If it takes a long time, the open-loop tracking time elapses, and the antenna must be driven at high speed to search for the satellite again for initial acquisition.Therefore, there is a problem that it takes a long time to restore the line. It was

The present invention solves such a problem, and an object of the present invention is to provide an apparatus capable of shortening the time required for reacquisition of a communication satellite when a mobile unit travels in an unreceivable section. ..

[0005]

According to the present invention, there is provided a tracking antenna, first control means for controlling the angle of the tracking antenna so that the intensity of a radio wave received by the tracking antenna is maximized, and the tracking antenna. An angular velocity sensor for detecting an angular velocity of a moving body attached to the moving body, second control means for controlling the angle of the tracking antenna according to the output of the angular velocity sensor, and the tracking so as to search for a radio wave received by the tracking antenna. Third control means for controlling the angle of the antenna, selection means for selecting any one of the first to third control means, and the strength of the radio wave not more than a predetermined value when the first control means is selected. Control circuit that selects the second control means, and selects the third control means when the intensity of the radio wave is below a predetermined value until a predetermined time elapses. In the control device, a speed sensor for detecting the speed of the movable body is provided, wherein the control circuit is characterized in that it comprises a means for changing the value of the predetermined time according to the output of the speed sensor.

[0006]

When the moving body is in a stopped state, the transmitter / receiver receives the radio wave from the tracking antenna by the first control means and controls the angle of the tracking antenna so that the intensity of the radio wave is maximized. When the moving body is moving, the angular velocity sensor detects the angular velocity each time the moving body changes its direction by the second control means, and the angle of the tracking antenna is controlled according to the output of the angular velocity sensor. Further, when the moving body suddenly changes its direction or when it loses sight of the satellite's direction due to the shadow of a large building, the high-speed search signal is used to search the radio wave received by the tracking antenna by the third control means. The generation circuit is operated to control the angle of the tracking antenna.

As described above, one of the first to third control means is selected according to the situation at that time. For example, when the first control means is selected, the second control means is selected when the intensity of the radio wave falls below a predetermined value, and when the intensity of the radio wave is below the predetermined value until a predetermined time elapses, the third control means is selected. Select control means.

[0008] While the moving body is moving, it may take a long time to pass through even if the section is a short section, for example, when the vehicle stops at a signal. In such a situation, the value of the predetermined time is changed according to the speed of the moving body detected by the speed sensor, and for example, the maximum duration of open loop tracking in the shadow wing section is made longer as the speed is lower, The loop can be continued so that it can be promptly re-acquired when it enters the receivable section again.

[0009]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the embodiment of the present invention.

In the embodiment of the present invention, the tracking antenna 1 and the first control means 11 for controlling the angle of the tracking antenna 1 so that the intensity of the radio wave received by the tracking antenna 1 is maximized.
An angular velocity sensor 4 for detecting the angular velocity of a moving body to which the tracking antenna 1 is attached, and a second control means 12 for controlling the angle of the tracking antenna 1 according to the output of the angular velocity sensor 4.
And third control means 13 for controlling the angle of the tracking antenna 1 so as to search the radio wave received by the tracking antenna 1.
And a selecting unit configured by the arithmetic unit 33 and the changeover switch 32 for selecting any one of the first to third control units 11 to 13, and when the first controlling unit 11 is selected for the arithmetic unit 33. When the intensity of the radio wave is below a predetermined value, the second control means 12 is selected, and when the intensity of the radio wave is below the predetermined value until a predetermined time elapses, a control circuit for selecting the third control means 13 is included. A speed sensor 5 for detecting the speed of the body is provided, and the control circuit includes means for changing the value of the predetermined time according to the output of the speed sensor.

The tracking antenna 1 has a driving device and tracks a communication satellite. The transceiver 2 receives the RF signal from the tracking antenna 1 and also transmits the RF signal to the tracking antenna 1,
At the time of satellite acquisition, an automatic tracking signal for keeping the acquisition state optimal is output, and a satellite acquisition signal is output while the satellite is being acquired.

The antenna control device 3 generates and outputs an antenna drive command based on the satellite capture signal from the transceiver 2, the automatic tracking signal, and the signals detected by various sensors.
The high speed search signal generating circuit 31 generates a high speed search signal for driving the antenna required for initial acquisition at high speed. The arithmetic unit 33 is connected to the timer 34, and switches the changeover switch 32 based on the satellite capture signal from the transceiver 2 and the speed information from the speed sensor 5.

The angular velocity sensor 4 detects the rotation of the moving body in the azimuth direction, the velocity sensor 5 detects the speed of the moving body, and the motor drive circuit 6 drives the antenna by the signal from the antenna control device 3 to reduce the speed. Reference numeral 8 decelerates the rotation speed of the motor 7 to drive the tracking antenna 1.

FIG. 2 is a flow chart showing the flow of operation of the embodiment of the present invention. The operation of the embodiment of the present invention will be described with reference to FIG.

First, after the operation is started, the tracking antenna 1 is operated at high speed.
To capture satellites (S101). Next, the state of satellite capture is determined based on the satellite capture signal from the transceiver 2, and when capture is in progress, automatic tracking is performed by the automatic tracking signal (S103), and the timer 34 used for open loop tracking is initialized. Perform (S104). This operation is sequentially repeated during satellite acquisition.

When the satellite is not captured in S102, open loop tracking is performed based on the azimuth direction rotation information from the angular velocity sensor 4 (S10).
5), the timer 34 based on the speed information from the speed sensor 5
Is operated (S106 to S108). At this time, the faster the timer 34, the faster the elapsed time. Next, a time-out is detected (S109), and when the time-out has not occurred, open-loop tracking is continued, and when the time-out has occurred, the process returns to the high-speed search in S101 to capture the satellite again.

In this way, by increasing the elapsed time of open loop tracking as the satellite speed is faster, when passing through a relatively short shadow wing section at a low speed, it is quickly reacquired after entering the receivable section again. Will be possible.

If the amount of rotation in the azimuth direction and the moving speed of the moving body can be detected from the rotation and steering angle of the tire of the vehicle, the information can be used.

[0019]

As described above, according to the present invention, the open loop can be continued when passing through a relatively short shadow wing section at a low speed, and when the receivable section is re-entered, the open loop can be promptly performed. There is an effect that can be recaptured.

[Brief description of drawings]

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

FIG. 2 is a flowchart showing a flow of operations of the embodiment of the present invention.

[Explanation of symbols]

 1 Tracking Antenna 2 Transceiver 3 Antenna Control Device 4 Angular Velocity Sensor 5 Speed Sensor 6 Motor Drive Circuit 7 Motor 8 Speed Reducer 11 First Control Means 12 Second Control Means 13 Third Control Means 31 High Speed Search Signal Generation Circuit 32 Changeover Switch 33 Arithmetic device 34 timer

Claims (1)

[Claims] 1. A tracking antenna, first control means for controlling the angle of the tracking antenna so that the intensity of a radio wave received by the tracking antenna is maximized, and an angular velocity of a moving body to which the tracking antenna is attached. An angular velocity sensor for detecting the angle, second control means for controlling the angle of the tracking antenna according to the output of the angular velocity sensor, and a third controller for controlling the angle of the tracking antenna so as to search the radio wave received by the tracking antenna. Control means, selecting means for selecting any one of the first to third control means, and the second control means when the intensity of the radio wave becomes a predetermined value or less when the first control means is selected. In an antenna control device comprising: a control circuit that selects the third control means when the intensity of the radio wave is equal to or less than a predetermined value until a predetermined time elapses, Serial speed sensor which detects the speed of the moving body, the control circuit antenna control device which comprises a means for changing the value of the predetermined time according to the output of the speed sensor.