JP2814820B2 - Antenna control device - Google Patents

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 to track a communication satellite.
The present invention relates to an antenna control device capable of re-acquiring a communication satellite in a short time even when a mobile body travels in a non-receivable section.

[0002]

2. Description of the Related Art Heretofore, this kind of antenna control apparatus has searched for a satellite by driving an antenna at a high speed after an open loop tracking for a predetermined time.

[0003]

When such a conventional antenna control device travels in an unreceivable section, even if the section is a short section, it passes through the section as if stopped by a signal. If this takes 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, which increases the time required for line recovery. Was.

An object of the present invention is to solve such a problem, and an object of the present invention is to provide an apparatus capable of shortening the time required for re-acquisition of a communication satellite when a moving object travels in an unreceivable section. .

[0005]

SUMMARY OF THE INVENTION The present invention provides a tracking antenna, first control means for controlling the angle of the tracking antenna so that the intensity of radio waves received by the tracking antenna is maximized, and the tracking antenna. An angular velocity sensor for detecting an angular velocity of a moving body to which is attached; a second control means for controlling an angle of the tracking antenna according to an 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 of the first to third control means, when the first control means is selected, the intensity of the radio wave is equal to or less than a predetermined value And a control circuit for selecting the second control means, and selecting the third control means when the intensity of the radio wave is equal to or less than a predetermined value until a predetermined time has elapsed. 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 object is in a stopped state, the transceiver 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 becomes maximum. When the moving body is moving, the angular velocity sensor detects the angular velocity each time the moving body changes direction by the second control means, and controls the angle of the tracking antenna according to the output of the angular velocity sensor. In addition, when the mobile unit suddenly changes direction or enters the shadow of a large building and loses track of the satellite, a high-speed search signal is issued by the third control means to search for a radio wave received by the tracking antenna. 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 becomes equal to or less than a predetermined value, and when the intensity of the radio wave is equal to or less than the predetermined value until a predetermined time has elapsed, the third control means is selected. Select control means.

[0008] During the movement of the moving body, it may take time to pass even if the section is a short section, for example, when the vehicle is stopped at a traffic light. In such a situation, the value of the predetermined time is changed according to the speed of the moving object detected by the speed sensor, for example, the maximum duration of open loop tracking in the shadow wing section is increased as the speed is lower, and the open time is increased. The loop can be continued so that it can be quickly re-captured when it enters the receivable section again.

[0009]

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

The embodiment of the present invention comprises a tracking antenna 1 and a 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 an angular velocity of a moving object to which the tracking antenna 1 is attached; and a second control means 12 for controlling an angle of the tracking antenna 1 according to an output of the angular velocity sensor 4.
And third control means 13 for controlling the angle of tracking antenna 1 so as to search for a radio wave received by tracking antenna 1.
And a selecting means including an arithmetic unit 33 and a changeover switch 32 for selecting any one of the first to third control units 11 to 13. When the first control unit 11 is selected by the arithmetic unit 33, A control circuit for selecting the second control means when the radio wave intensity is equal to or lower than a predetermined value, and selecting the third control means when the radio wave intensity is equal to or lower than a predetermined value until a predetermined time has elapsed; 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 transmits the RF signal to the tracking antenna 1,
At the time of capturing a satellite, an automatic tracking signal for keeping the capturing state optimal is output, and a satellite capturing signal is output when the satellite is being captured.

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

An angular velocity sensor 4 detects the rotation of the moving body in the azimuth direction, a speed sensor 5 detects the speed of the moving body, a motor drive circuit 6 drives the antenna according to a signal from the antenna control device 3, and a speed reducer. 8 drives the tracking antenna 1 by reducing the rotation speed of the motor 7.

FIG. 2 is a flowchart showing the operation flow 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 starts, the tracking antenna 1 is operated at high speed.
Is driven to capture a satellite (S101). Next, the state of the satellite capture is determined based on the satellite capture signal from the transceiver 2, and if the satellite is being captured, 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.

If it is determined in step S102 that the satellite is not being captured, open-loop tracking is performed based on rotation information in the azimuth direction from the angular velocity sensor 4 (S10).
5), a timer 34 based on the speed information from the speed sensor 5
Is operated (S106 to S108). At this time, the timer 34 increases the elapsed time as the speed increases. Next, a timeout is detected (S109), and if the timeout has not occurred, the tracking by the open loop is continued.

In this way, by making the elapsed time of the open loop tracking faster as the speed of the moving body becomes faster, when passing through a relatively short shadow wing section at a low speed, the mobile station quickly re-enters the receivable section. Capture becomes possible.

If the rotation amount in the azimuth direction and the moving speed of the moving body can be detected from the rotation and the 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 the vehicle passes through a relatively short section of the shadow wing section at a low speed, and promptly when entering the receivable section again. Has the effect of being able to be captured again.

[Brief description of the drawings]

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

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tracking antenna 2 Transceiver 3 Antenna controller 4 Angular velocity sensor 5 Speed sensor 6 Motor drive circuit 7 Motor 8 Reducer 11 First control means 12 Second control means 13 Third control means 31 High-speed search signal generation circuit 32 Switching switch 33 Arithmetic unit 34 timer

Claims (1)

(57) [Claims] A tracking antenna; first control means for controlling an angle of the tracking antenna such that the intensity of radio waves received by the tracking antenna is maximized; and an angular velocity of a moving object to which the tracking antenna is attached. An angular velocity sensor that detects an angle of the tracking antenna; a second control unit that controls an angle of the tracking antenna according to an output of the angular velocity sensor; and a third control unit that controls an angle of the tracking antenna so as to search for a radio wave received by the tracking antenna. Control means, selecting means for selecting any of the first to third control means, and the second control means when the intensity of the radio wave becomes equal to or less than a predetermined value when the first control means is selected. A control circuit for selecting 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.