JPH0630403B2 - Parabolic antenna automatic tracking method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention changes the elevation angle and azimuth angle of a parabolic antenna mounted on a moving object such as a ship according to the movement of the moving object from an artificial satellite. The present invention relates to a tracking method for satisfactorily receiving radio waves of.

[Conventional technology]

Conventionally, the automatic tracking technology for parabolic antennas has
As disclosed in JP-A-46010, an AZ drive unit and an EL for driving an antenna in the AZ axis direction and the EL axis direction, respectively.
There is a drive unit and a control circuit that drives the antenna intermittently so that the electric field received from the artificial satellite is maximized.

[Problems to be solved by the invention]

However, the above technique has a problem that when a ship carrying an antenna moves, the antenna may not stop at that position, even though the position is at a position where the received electric field is maximum.

[Means for solving problems]

In order to solve the above problems, the present invention receives radio waves from an artificial satellite by a parabolic antenna to detect a reception level, and also detects an elevation angle and an azimuth angle of the parabolic antenna, thereby artificially constructing the parabolic antenna. In the method of tracking to a satellite, the initial elevation angle is set based on the longitude of the position where the moving object is stopped when the moving object is stopped, and the elevation angle and azimuth angle of the parabolic antenna mounted on the moving object are set. And changing the elevation angle and azimuth angle of the parabolic antenna when a azimuth angle at which a reception level equal to or higher than a set level is obtained within a predetermined elevation angle, and the elevation angle after the movement of the moving object is started. And a determination step of determining whether the reception level is equal to or higher than the set level in the azimuth adjustment stop state, and the reception step in the determination step. When it is determined that the bell is equal to or higher than the set level, the step of returning to the determination step, and when it is determined that the reception level is not equal to or higher than the set level in the determination step, the elevation angle and the azimuth elevation angle and The azimuth is changed linearly and spirally by a constant angle, and when the reception level becomes equal to or higher than the set level, the elevation angle and the azimuth of the parabolic antenna are stopped, and then the process returns to the determination step. It is equipped with.

[Action]

According to the present invention, first, the parabolic antenna is adjusted to an elevation angle and an azimuth angle at which the reception level becomes equal to or higher than the set level within a predetermined elevation angle after the initial elevation angle is set in the stopped state of the moving object, and the change is stopped in that state. It Then, when the moving object moves, it is determined in the determination step whether the reception level is equal to or higher than the set level in the state where the adjustment is performed, and if the received level is equal to or higher than the set level, the elevation angle and the azimuth angle are maintained. When the moving level of the moving object progresses and the reception level does not exceed the set level, until the receive level reaches the set level,
The elevation angle and azimuth angle of the parabolic antenna are changed linearly and spirally by a fixed angle within the allowable range based on the elevation angle and azimuth angle at that time, and the elevation angle and azimuth angle at which the reception level is above the set level are determined. , Stop changing elevation and azimuth at that position. Then, after that, the determination step is executed again. Therefore, when the movement of the moving object further progresses and the reception level is not higher than the set level again, the elevation angle and the azimuth angle are changed with reference to the azimuth angle and the elevation angle at that time, and the elevation angle and the reception level above the set level are changed. Search for azimuth.

〔Example〕

First, an apparatus used for carrying out this embodiment will be described with reference to FIG. In the figure, 2 is a moving object, for example, a parabolic antenna mounted on a ship,
The elevation angle of the parabolic antenna 2 can be changed by the hydraulic actuator 4, and its azimuth angle can be changed by the hydraulic actuator 6. Electromagnetic valves 8 and 10 are provided to change the flow direction of the oil supplied to the actuators 4 and 6. These solenoid valves 8 and 10 are controlled by the solid state relay unit 12
Is performed by a control signal from.

The hydraulic actuator 4 is provided with a potentiometer 14 for detecting the elevation angle of the parabolic antenna 2, and similarly, the hydraulic actuator 6 is provided with a potentiometer 16 for detecting the azimuth angle of the parabolic antenna 2. The output signals of these potentiometers 14 and 16 are A
The digital signal is converted by the / D converter 18 and supplied to the microcomputer 20. In addition, the signal from the geostationary satellite received by the parabolic antenna 2 is converted to a low frequency by the BS converter 22, and then the BS tuner is used.
At 24, the signal is reconverted into a signal receivable by the television receiver and supplied to the television receiver 26. The reconverted signal is detected in the BS tuner 24, and the reception level signal obtained is detected by the microcomputer via the A / D converter 18.
Supply to 20.

In addition to the above, the present east longitude and north latitude positions of the ship supplied from the digital switches 28 and 30 are also input to the microcomputer 20. Note that the east longitude position is absolutely 100 degrees or more in the sea near Japan, so enter the digit of 100 without entering it.

The microcomputer 20 outputs the potentiometers 14 and 16, the BS tuner 24 and the digital switch 2.
A control signal is generated in the solid-state relay 12 via the driver unit 32 according to the outputs of 8 and 30. Incidentally, 34 is a reset switch, and 36 is a follow-up stop switch.

Next, a method of determining the elevation angle and the azimuth angle of the parabolic antenna 2 when the ship is stopped will be described with reference to FIG. First, in step 40, the east longitude and north latitude positions input from the digital switches 28 and 30 are read, and in step 42, the elevation angle of the parabolic antenna 2 is set to the elevation angle corresponding to this position. Then step
At 43, the azimuth of the parabolic antenna 2 is mechanically rotated to a position of 0 °, and at step 44, the parabola antenna 2 is rotated to the left to change the azimuth by 0.5 °. In step 46, it is determined whether or not one revolution has been performed, and if it has not yet completed one revolution, it is determined in step 48 whether or not the reception level is equal to or higher than α, which is a level at which the image can be properly received by the television receiver. , Α, the parabola antenna 2 is stopped in step 50. If it is not more than α, steps 44, 46 and 48 are repeated until the parabolic antenna 2 makes one rotation. If there is no azimuth angle of α or more during one rotation, the process proceeds from step 46 to step 52. In step 52, it is determined whether or not the previous one rotation is the first one rotation. Now 1
Since it was the rotation, the value x of the counter representing the change angle of the elevation angle above the set elevation angle is set to 0.5 which is the predetermined elevation angle change angle in step 54, and the value of x is greater than the set angle of elevation angle in step 56. I give only (0.5 at the moment). Then, in step 58, it is determined whether x is a predetermined upper limit elevation angle of 5 °, but since it is not 5 ° at this time, step
At step 62, x is increased by an elevation angle change angle of 0.5 in preparation for the next elevation angle change. So at the moment,
The value of x is 1.

Then, in step 64, the parabolic antenna 2 is rotated to the right, the azimuth angle is changed, and in step 66, it is determined whether or not it has made one rotation. If it has not made one rotation, the reception level is α or more in step 68. If it is α or more, step
Go to 50 and stop. If it is not more than α, steps 64, 66 and 68 are repeated. If α is not exceeded during one rotation, the process proceeds from step 66 to step 70, and it is determined whether it is the first right rotation. Since it was the first rotation now,
Moving to step 72, the value y of the counter representing the angle of change of the elevation angle below the set elevation angle is set to a predetermined elevation angle change angle −0.
5, and the elevation angle is lowered by y (currently −0.5 °) from the set elevation angle in step 74. Then, in step 76, it is determined whether y is the lower limit elevation angle of -5 °. Since it is not -5 ° at this point, in step 78, y is decreased by -0.5 in preparation for the next downward elevation angle change. At this point, the value of y is -1. Then, the process returns to step 44.

While steps 44, 46, and 48 are repeated, that is, while the second left rotation of the azimuth angle is being performed, the reception level is α
If not, step 56 is executed again from step 46 through step 52. At this time, since the value of x is 1 as described above, the elevation angle is raised by 1 ° above the set elevation angle. Then, through step 58, step 62 is executed, and the value of x is increased by the elevation angle change angle 0.5, that is, 1.5, in preparation for the next elevation angle change to the upper side. And
Steps 64, 66, and 68 are repeated, and the second right rotation is performed. If the reception level does not become α or higher during this time, step 74 is executed through steps 66 to 70.
At this time, since the value of y is -1, the elevation angle is lowered by 1 ° from the set elevation angle, and it is determined in step 76 whether the value of y is -5. Since it is not -5 °, the next step 78 is performed. The value of y is reduced by -0.5 in preparation for a downward elevation change. Therefore, the value of y is -1.5. And step 4
Steps 4, 46 and 48 are repeated and the third left rotation is performed. Similarly, 0.5 ° within ± 5 ° of the set elevation angle
The elevation angle is changed up and down one by one, and the elevation angle and the azimuth angle at which the reception level becomes α or more are determined. If the reception level does not exceed α within ± 5 °, the movement of the parabolic antenna 2 is stopped and the settings are reset.

Next, a method of determining the elevation angle and the azimuth angle of the parabolic antenna 2 when the ship moves will be described with reference to FIGS. 3 and 4. In this method, the azimuth angle and the elevation angle are in a clockwise spiral from the 0 point shown in FIG. 4 (the position determined in the flow chart shown in FIG. 2) in the range of azimuth angle ± 10 ° and elevation angle ± 5 °. When the reception level becomes α or higher while changing 0.5 degree at a time, the parabolic antenna 2 is stopped at that position.

First, as shown in FIG. 3, the process moves from step 50 to step 80, and it is determined whether or not the reception level is α or more. If it is α or more, the process returns to step 50 and the parabolic antenna 2 is set to 0.
Stay in the point position. If it is not more than α, the azimuth is determined in step 82, but the initial number of movements n in the azimuth direction is predetermined to "1", and since it is an odd number, the azimuth angle is moved 0.5 ° to the right in step 84. Then, the parabolic antenna 2 is oriented in the direction of point a in FIG. Next, in step 86, it is determined whether the azimuth angle is within 10 °, but currently it is 10 °.
Since it is within the range, the process proceeds to step 88. In step 88, it is determined whether or not the reception level is α or higher, and if α or higher, the process returns to step 50. If it is not greater than α, it is judged in step 90 whether or not it has moved a predetermined number of times n (currently 1). Since it has moved a predetermined number of times n, in step 92 a predetermined elevation angle ±
Determine if it is within 5 °. Since it is currently within 5 °, the elevation direction is determined in step 94. Here, the number of movements of the elevation angle is also set to "1", and since it is an odd number, it is moved upward by 0.5 ° in step 96 and moved to the point b. Then, in step 98, it is determined whether or not the reception level is α or more, and if it is α or more, the process proceeds to step 50. If not more than α, step
At 100, it is judged whether or not it has moved n times (currently "1"), but since it has moved, the process returns to step 82.

In step 82, the azimuth direction is determined again. However, the next azimuth movement number n is set to "2", which is an even number, so in step 102, it is moved 0.5 ° to the left and moved to point c. Next, steps 86 and 88 are executed. If the reception level is α or more in step 88, the process returns to step 50, and if it is not α or more, it is determined in step 90 whether n times (currently “2”) have been moved. Since we have only moved once, steps 82, 1
Execute 02 and move to point d. Next, through step 86, if the reception level is equal to or higher than α in step 88, the process returns to step 50, and if it is not equal to or higher than α, it is determined in step 90 whether n times (currently “2”) have been moved. Since it has moved, the process proceeds to step 94 after step 92. Step 94
Then, the elevation angle direction is determined again, but the next azimuth movement number n is set to "2" and is an even number. Therefore, in step 104, the azimuth movement number is moved downward by 0.5 ° and moved to the point e. Next, at step 98, if the reception level is α or higher, the process returns to step 50. If it is not greater than or equal to α, move to step 100 and judge whether or not it has moved n times (currently “2”). However, since it has moved only once, execute steps 92, 94 and 104, and set f point. Move to. Next, in step 98, if the reception level is α or higher, the process returns to step 50, and if it is not α or higher, the step
At 100, it is judged whether or not it has moved n times (currently "2"), but since it has moved, it returns to step 82. Similarly, the elevation angle and the azimuth angle are changed spirally as shown in FIG. 4 until the reception level becomes α or higher. The allowable range of azimuth is ± 10 °, while the allowable range of elevation is ± 5 °. Therefore, from the point of exceeding ± 5 ° of azimuth, if it is perfect as shown in FIG. It does not become spiral. Also,
If the reception level does not exceed α even if the azimuth angle is changed by ± 10 °, return to the start in Fig. 2. When the reception level becomes α or more in step 88 or 98, step 50 is executed to maintain the parabolic antenna at the elevation angle and the azimuth angle at which the reception level is α or more. Then, step 80 is executed, and when the reception level is not higher than α again, step 82 and the subsequent steps are executed to again adjust the elevation angle and azimuth angle of the parabolic antenna in a spiral shape. That is,
Each time the reception level is no higher than α, the elevation angle and azimuth angle are adjusted in a spiral manner starting from the elevation angle and azimuth angle at that time.

In the above embodiment, the azimuth angle and the elevation angle are changed in the counterclockwise spiral shape, but the azimuth angle and the elevation angle may be changed in the clockwise rotation spiral shape. In the above embodiment, the azimuth angle is changed first, but the elevation angle may be changed first to change the azimuth angle and the elevation angle in a clockwise or counterclockwise spiral shape. Moreover, although the elevation angle and the azimuth angle are moved by 0.5 °, the invention is not limited to this. Also, the allowable range of elevation angle and azimuth angle is ± 5.
It is not limited to ° and ± 10 °. Further, although the hydraulic actuators 4 and 6 are used, a servo motor or the like may be used instead.

〔effect〕

As described above, according to the present invention, the elevation angle and the azimuth angle of the parabolic antenna are adjusted so that the reception level becomes equal to or higher than the set level when the moving object is stopped. After that, when the moving object moves, it is determined in the determination step whether the reception level is equal to or higher than the set level. When the reception level is equal to or higher than the set level, the elevation angle and azimuth angle at that time are maintained. If the reception level is not above the set level,
The elevation level and azimuth are linearly and spirally changed by a fixed angle based on the elevation angle and azimuth at that time so that the reception level is above the set level. Adjust to azimuth. Then, the process returns to the judgment stage. Therefore, whenever the moving object moves and the reception level is no higher than the set level, the elevation angle and the azimuth angle are adjusted linearly and spirally at a constant angle with respect to the elevation angle and the azimuth angle at that time. The reception level can be promptly raised to the set level or higher. Furthermore, instead of always adjusting the reception level to the maximum value, the adjustment is performed when the reception level is no higher than the set level, so the drive unit of the parabolic antenna does not always operate,
Drive energy loss is reduced. Moreover, since the tracking method of the present invention does not detect a deviation from the reference elevation angle or azimuth angle, only the reception level needs to be monitored, so the configuration of the device used for implementing this method is simplified. it can.

[Brief description of drawings]

FIG. 1 is a block diagram of an apparatus used for one embodiment of the parabolic antenna automatic tracking method according to the present invention, FIG. 2 is a flow chart showing a part of the same embodiment, and FIG. 3 is the rest of the same embodiment. A flow chart, FIG. 4 is a view showing a changed state of the azimuth angle and the elevation angle of the parabolic antenna according to the embodiment. 2 ... Parabolic antenna, 4, 6 ... Hydraulic actuator, 14, 16 ... Potentiometer, 20 ... Microcomputer.

Claims (1)

[Claims] 1. A method in which a parabolic antenna receives radio waves from an artificial satellite to detect a reception level, and also detects an elevation angle and an azimuth angle of the parabolic antenna to track the parabolic antenna to the artificial satellite. Is set to an initial elevation angle based on the longitude of the stop position of the moving object in a stopped state, the elevation angle and the azimuth angle of the parabolic antenna mounted on the moving object are changed, and within a predetermined elevation angle, a set level or more is set. When the azimuth angle at which the reception level is obtained is obtained, the step of stopping the adjustment of the elevation angle and the azimuth angle of the parabolic antenna, and the reception level in the elevation angle and azimuth angle adjustment stop state after the start of the movement of the moving object is At the determination step of determining whether or not it is above the set level, it is determined that the reception level is above the set level at this determination step. If it is determined that the reception level is not equal to or higher than the set level in the step of returning to the determination step and that in the determination step, the elevation angle and the azimuth angle of the elevation angle and the azimuth angle at that time are fixed linearly and spirally. A method of automatically tracking a parabolic antenna, which comprises changing the angle by angle, stopping the elevation angle and azimuth angle of the parabolic antenna when the reception level becomes equal to or higher than the set level, and then returning to the determination step. .