JP3014910B2 - Directional direction control method for mobile receiving antenna - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention detects a receiving state of a mobile receiving antenna mounted on a moving body such as a vehicle, and controls the directional direction of the antenna in a stepwise manner so as to increase the receiving strength. The present invention relates to a direction control method for a mobile receiving antenna.

[0002]

2. Description of the Related Art When communicating via a satellite or receiving a satellite broadcast, it is necessary to sharpen the directivity of a terrestrial receiving antenna in order to obtain good reception quality. If the antenna is mounted on a moving body such as a vehicle, it is necessary to control the antenna so that it is accurately directed to the satellite in the elevation plane or the azimuth plane depending on the traveling state or reception state of the moving body. is there. As a method of controlling the directional direction of the mobile receiving antenna, conventionally,
A step-type satellite tracking method in which the direction of the antenna is controlled mechanically or electrically to cause the satellite to track in a step-wise manner so that the reception intensity of the antenna is increased is adopted.

FIGS. 2 and 3 are diagrams for explaining such a control technique. FIG. 2 is a block diagram showing an antenna device for mechanically controlling the directional direction of a mobile receiving antenna.
FIG. 3 is a block diagram showing an antenna device for electrically controlling the directivity of a mobile receiving antenna.

That is, in the case of a mobile receiving antenna capable of mechanically changing the directional direction, as shown in FIG. 2, when it is determined in the processing by the control device 1 that the directional direction of the antenna 4 needs to be changed, the control is performed. A pulse-like drive command signal and a drive direction designation signal are output from the device 1 to the drive circuit 2.
When one pulse of the drive command signal is input to the drive circuit 2, the drive circuit 2 rotates the antenna 4 by one step angle in the direction designated by the drive direction designation signal in the elevation plane or the azimuth plane. The drive mechanism 3 is activated so as to perform the operation. That is, the driving mechanism 3 connected to the antenna 4 rotates the antenna 4 in the elevation plane or the azimuth plane by an angle proportional to the step angle, and outputs a one-pulse drive command output from the control device 1. In response to the signal, the antenna 4 rotates by one step angle in the direction specified in the elevation plane or the azimuth plane, and the directivity direction is changed. Then, the signal received by the antenna 4 is sent to an A / D converter 6 via a receiver 5 and is sampled at a predetermined time interval by the A / D converter 6 and converted into a digital value. The strength of the received signal is taken into the control device 1 and used for controlling the directivity of the antenna 4.

[0005] In the case of a mobile receiving antenna whose directional direction can be changed electrically, as shown in FIG.
When it is determined that the directivity direction of the array antenna 9 needs to be changed in the processing in step 1 and the drive command signal is output by the control device 1 to the phase shifter control circuit 7 in one pulse, the phase shifter control circuit 7
Sets the phase shift amount of each phase shifter 8 so that the directivity of the array antenna 9 changes by one step angle in the direction specified by the drive direction specifying signal in the elevation plane or the azimuth plane. The received signals of the sub-arrays (or antenna elements) 10 constituting the array antenna 9 are input to each of the phase shifters 8, and the phases thereof are changed by the set phase shift amount. 8 are combined in a combiner 11 to obtain a received signal as an array antenna 9. That is, in response to the one-pulse drive command signal output from the control device 1, the directivity of the array antenna 9 changes by one step angle in the direction specified in the elevation plane or the azimuth plane, The received signal is output from the synthesizer 11 to the receiver 5, and thereafter, the same processing as in FIG. 2 is performed. That is, FIG. 2 and FIG. 3 are different from each other in a processing method of a portion surrounded by a broken line.

Next, a conventional control method for controlling the directional direction of the mobile receiving antenna will be described with reference to a flowchart of FIG. 4 by taking azimuth control as an example.

As shown in FIG. 4, first, the strength of a signal received by a mobile receiving antenna pointing at a certain azimuth is measured, and it is determined whether or not the received strength LEV1 is equal to or greater than a predetermined strength TH. As a result, if LEV1 ≧ TH, reception is continued without changing the pointing direction of the antenna, but LEV1 <
In the case of TH, after changing the directivity of the antenna by one step in a predetermined direction (left direction in this example), the reception intensity LEV2 is measured and the first reception intensity LEV is set.
Compare with 1. Then, as a result of the comparison, LEV2 ≧ LE
In the case of V1, it is determined that the direction of the antenna has been changed to the left, and the direction of the satellite has been approached. So, LEV
2 is compared with the predetermined intensity TH, and if LEV2 is less than TH, the LEV2 is set to a new LEV1 and the process returns to the previous step of changing the direction of the antenna leftward by one step. Thereafter, the directional direction of the antenna is changed to the left one step at a time until the reception intensity equal to or higher than the predetermined intensity TH is obtained.

However, LEV2 and the first measured LEV
When LEV2 <LEV1 as a result of comparison with 1, it is determined that the antenna has been moved away from the satellite direction by changing the pointing direction of the antenna to the left. Therefore, after changing the directivity of the antenna by two steps in a direction opposite to the direction defined in advance (to the right in this example), the reception intensity LEV3
Is measured, and the value is compared with the first reception intensity LEV1. Then, when it is determined in this comparison that LEV3 ≧ LEV1, it is determined that the direction of the antenna has been changed to the right to approach the satellite. So, LEV
3 is compared with the predetermined intensity TH. If LEV3 is less than TH, the LEV3 is set to a new LEV1, the directivity direction of the antenna is changed rightward by one step, and then the new reception intensity LEV3 is set again. Return to the previous step of measuring. Thereafter, the directional direction of the antenna is changed to the right one step at a time until a reception intensity equal to or higher than the predetermined intensity TH is obtained.

Note that LEV3 and LEV1 initially measured are
As a result, when LEV3 <LEV1, it can be determined that the initial reception intensity LEV1 is the maximum intensity even if the intensity is less than the predetermined intensity TH. Return to the state.

FIG. 5 is a characteristic diagram showing the relationship between the directional direction of a mobile receiving antenna and the strength of a received signal in order to specifically explain the conventional control method described above.

In FIG. 5, assuming that the direction of the antenna initially set is the direction A and the direction of the satellite is the direction C which is shifted to the right by one step from the direction A, the antenna pointing in the direction A is first set. Is measured when receiving the signal transmitted from the satellite, and the value is compared with a predetermined intensity TH. In this case, since LEV1 is smaller than the value of TH, the directivity direction of the antenna is changed from the A direction to the predetermined leftward by one step to the B direction, and the reception intensity LEV2 measured in that state is changed.
Is compared with the previous LEV1. As a result, LEV2 becomes LE
It is smaller than V1 and it is determined that if the direction of the antenna is changed from A to left, it will move away from the satellite.
Since the cross-sectional, and C direction was changed by two steps the pointing direction of the antenna from the B direction to the right, comparing the reception intensity LEV3 measured in that state preceding LEV1 with. As a result, it is determined that LEV3 ≧ LEV1 and LEV3
Is compared with the predetermined strength TH, the determination that LEV3 ≧ TH is made, so that the reception is continued with the directivity direction of the antenna set to the C direction.

In FIGS. 4 and 5, the conventional directional control method of the mobile receiving antenna is described by taking the azimuth control as an example. However, the control of the elevation angle is performed in the same manner.

[0013]

By the way, in such a step-type satellite tracking system, when the intensity of a signal received first by an antenna is lower than a predetermined intensity, the directivity of the antenna is changed by one step for the time being. In the past, since the change direction at the time of the first change of the pointing direction has been defined in advance, it is first defined when a situation in which a change in the direction opposite to the change direction is required continues. The procedure of changing the directivity of the antenna in the direction and then reversing the change direction has to be repeated, so that it takes a long time to adjust the directivity of the antenna, and there is a problem that the reception quality is likely to deteriorate.

[0014] For example, as shown in FIG. 6, the left bending road
When approaching, the moving direction E of the moving object is changed to the direction D of the satellite.
, The pointing direction of the mobile reception antenna 13 is first changed to the left and then to the right again, so that every time the control for obtaining good reception quality is performed, Inefficient control is performed such that an unnecessary process of lowering the reception intensity is performed. In some cases, there is a problem that the adjustment of the pointing direction cannot keep up with the rotation of the moving body.

[0015] Even when the first change direction of the directivity control of the mobile receiving antenna is defined to be rightward,
When a moving object equipped with the antenna travels on a road that makes a right turn with respect to the direction of the satellite, the same inefficient control as described above must be performed.

The present invention has been made in view of such problems of the prior art, and an object of the present invention is to provide a pointing direction of a mobile receiving antenna capable of always obtaining good reception quality regardless of a traveling environment of a moving body such as a vehicle. It is to provide a control method.

[0017]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a control method for controlling the directivity of a mobile receiving antenna mounted on a mobile object in a stepwise manner. Predetermined intensity
And the directional direction of the mobile receiving antenna is changed
When that is achieved by the rotation direction of the start in the same direction as the rotation of the immediately preceding.

[0018]

Further, the object of the present invention is to provide a control method for controlling the directivity of a mobile receiving antenna mounted on a moving body in a stepwise manner so that the strength of a signal received by the mobile receiving antenna is equal to or higher than a predetermined strength. A first step of changing the pointing direction of the antenna by one step to a designated direction when the strength of a signal received by the mobile receiving antenna is less than a predetermined strength, and changing the pointing direction by one step in the first step; A second step of comparing the changed reception strength of the antenna with a comparison strength that is the reception strength of the antenna before the change, and the reception strength after the change in the directivity direction is greater than or equal to the comparison strength in the comparison in the second step. And when the reception intensity is less than the predetermined intensity, the reception intensity is set as a new comparison target intensity and the first intensity is set.
When the reception strength after changing the directivity in the third step and the second step returns to the step, the change direction of the directivity control of the antenna is changed to the opposite direction. A fourth step in which the pointing direction of the antenna is changed by two steps in the newly specified direction, and the reception intensity of the antenna in which the pointing direction is changed by two steps in the fourth step is compared with the comparison target. A fifth step of comparing the received intensity with the intensity, and when the received intensity after the change in the directivity direction is greater than or equal to the intensity to be compared and less than the predetermined intensity in the comparison in the fifth step, the received intensity is set as a new intensity to be compared. And returning to the first step.

[0020]

According to the above means, the receiving intensity of the mobile receiving antenna becomes less than the predetermined intensity, and
When the direction is changed, since the desired reception strength change direction control before <br/> round of the orientation control is set to the same direction as the change direction obtained, for example, orientation control of the azimuth angle In the case where the moving object equipped with the antenna travels on a road that turns left with respect to the direction of the satellite, the change direction of the directional control of the antenna will be set rightward from the next time, and When the mobile body travels on a road that turns right with respect to the direction of the satellite, the change direction of the directivity control of the antenna is set to the left from the beginning.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method for controlling the directivity of a mobile receiving antenna according to the present invention will be described below with reference to the flowchart of FIG.

As shown in FIG. 1, first, in S1, the reception strength LEV1 of a mobile receiving antenna mounted on a moving body such as a vehicle is measured. Next, in S2, the reception intensity L
It is determined whether EV1 is equal to or greater than a predetermined strength TH. And
If it is determined in step S2 that LEV1 ≧ TH, the reception is continued without changing the directivity of the antenna. On the other hand, LE
When it is determined that V1 <TH, the process proceeds to S3, in which the pointing direction of the antenna is changed by one step in the designated direction (the antenna is rotated by one step angle in the case of mechanical control), and further one step is performed in S4. Received intensity LE after change
Measure V2.

Next, in step S5, the reception intensity LEV2 is compared with the reception intensity LEV1 before the change, and LEV2 ≧ LEV
If it is determined to be 1, it is determined that the direction of the antenna has been changed to the specified direction, and that it has approached the direction of the satellite.
Then, the process proceeds to S6, where the LEV2 is compared with the predetermined intensity TH. If the LEV2 is equal to or more than TH, the reception is continued as it is, but if the LEV2 is less than TH, the process proceeds to S7 to replace the LEV2 with a new LEV1, After setting the comparison target intensity, the process returns to S3 in which the directivity direction of the antenna is changed to the designated direction by one step. Thereafter, the directional direction of the antenna is changed to a fixed direction one step at a time until a reception intensity equal to or higher than the predetermined intensity TH is obtained.

On the other hand, as a result of comparing LEV2 with the reception intensity LEV1 before the change in S5, if LEV2 <LEV1, it is determined that the antenna was moved away from the direction of the satellite by changing the pointing direction of the antenna to the specified direction. to decide. Therefore, in S8, the change direction of the antenna directional control is specified in the opposite direction, then in S9, the directional direction of the antenna is changed by two steps to the newly specified direction, and in S10, the reception intensity LEV3 is measured. I do.

At S11, the reception strength LEV3
Is compared with the reception intensity LEV1 before the change, and LEV3 ≧ LE
If it is determined to be V1, it is determined that the direction of the antenna has been changed to the direction opposite to the direction up to that and the vehicle has approached the direction of the satellite. Then, the process proceeds to S12, where the LEV3 is compared with the predetermined strength TH. If the LEV3 is equal to or more than TH, the reception is continued, but if the LEV3 is less than TH, the process proceeds to S13, where the LEV3 is compared with the new comparison target strength. LEV
After setting to 1, the process returns to S3 in which the directional direction of the antenna is changed to the designated direction by one step. Thereafter, the directional direction of the antenna is changed to a fixed direction one step at a time until a reception intensity equal to or higher than the predetermined intensity TH is obtained.

If it is determined in step S11 that LEV3 is smaller than LEV1, it is determined that LEV3 <LEV1.
Even if the intensity is less than the predetermined intensity TH, the comparison target intensity LEV1 can be determined to be the maximum intensity. Therefore, the process proceeds to S14, in which the change direction of the directivity control of the antenna is specified in the opposite direction, and then the process proceeds to S15. Is changed to the newly designated direction by one step, and the original state is restored.

As described above, in the above embodiment, the change direction of the directivity control performed first when the reception intensity of the mobile reception antenna is less than the predetermined intensity TH is not defined in advance, and the desired direction is not determined by the previous control. The receiving intensity is set to the same direction as the last change direction obtained. That is, when the direction of the antenna deviates from the direction of the satellite and the reception intensity decreases below the predetermined intensity TH, the first change of the direction of the direction is first performed in S3 of the flowchart of FIG. Since the direction is the same as the change direction finally specified in the previous directional control, if, for example, the directional direction of the antenna is changed to the right when the previous control is completed, the first time of FIG. The change direction in S3 is also rightward, and if the last last change direction is leftward, the current first change direction is also leftward.

Therefore, when the above-described embodiment is applied, a moving object such as a vehicle equipped with an antenna is traveling on a road that turns left with respect to the satellite direction. In the case of a shift to the left, the change direction of the pointing direction control is set to the right from the beginning, so that it is unnecessary to change the pointing direction to a direction that decreases the reception intensity (in this case, the left direction). Efficient control without steps can be performed. Further, when the moving body is traveling on a right-turn road with respect to the direction of the satellite, the direction of change of the directional control of the antenna is set to the left from the beginning. Efficient control without unnecessary steps can be performed.

[0029]

As described above, according to the present invention,
The reception intensity of mobile reception antenna becomes less than the predetermined intensity
When the directivity direction of the moving receiving antenna is changed, because it is set in the same direction as the last change direction desired reception intensity obtained in the finger <br/> control change direction countercurrent direction control is last,
For example, when a mobile object such as a vehicle equipped with an antenna travels on a road that turns left with respect to the direction of the satellite, the direction in which the directional control of the antenna is changed is set rightward from the beginning, and When the mobile body travels on a right-turn road with respect to the direction of the satellite, the direction of change of the directivity control of the antenna is set to the left from the beginning, and it is unnecessary to lower the reception strength. Therefore, it is possible to provide a directivity control method for a mobile receiving antenna that can always obtain good reception quality regardless of the traveling environment of a mobile object.

[Brief description of the drawings]

FIG. 1 is a flowchart for explaining an embodiment of the present invention.

FIG. 2 is a block diagram illustrating an antenna device that mechanically controls a directional direction of a mobile receiving antenna.

FIG. 3 is a block diagram showing an antenna device for electrically controlling a directional direction of a mobile receiving antenna.

FIG. 4 is a flowchart for explaining a conventional technique.

FIG. 5 is a characteristic diagram showing a relationship between a directivity direction of a mobile receiving antenna and a received signal strength.

FIG. 6 is an explanatory diagram showing a state in which a moving object equipped with an antenna is traveling on a road that turns left with respect to the direction of the satellite.

[Explanation of symbols]

 12 Moving object (vehicle) 13 Mobile receiving antenna

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-188126 (JP, A) JP-A-61-118675 (JP, A) JP-A-5-232205 (JP, A) JP-A-4- 307381 (JP, A) JP-A-62-165170 (JP, A) JP-A-3-175385 (JP, A) JP-A-4-204169 (JP, A) JP-A-4-64074 (JP, A) (58) Field surveyed (Int.Cl. ⁷ , DB name) G01S 3/00-3/74 H01Q 1/00-1/52

Claims (3)

(57) [Claims] 1. A control method for controlling the directivity of a mobile receiving antenna mounted on a mobile body in a stepwise manner, wherein the strength of a received signal received by the mobile receiving antenna is preset.
A directivity control method for a mobile reception antenna, comprising: setting the first rotation direction to be the same as the immediately preceding rotation direction when the directivity direction of the mobile reception antenna is changed to be less than a predetermined strength. . 2. A mobile receiver antenna mounted on the mobile body
The antenna is controlled so that the strength of the received signal is equal to or higher than a predetermined strength.
In a control method that controls the direction of the tena in a step-wise manner.
The strength of the signal received by the mobile receiving antenna
Less than the designated direction of the antenna.
A first step of changing only one step at a time,
Of the antenna whose directivity is changed by one step in the process
Comparison target which is the reception strength of the antenna before changing the signal strength
A second step of comparing the strength and the second step
Is the reception strength after changing the pointing direction in comparison higher than the comparison target strength?
When the received power is less than the predetermined strength,
A third step of setting the elephant intensity and returning to the first step;
In the comparison in the second step, the reception strength after changing the pointing direction
When the degree is less than the comparison target strength,
Specify the direction of direction control change in the opposite direction
In addition, the pointing direction of the antenna is changed to the newly specified direction.
A fourth step of changing only two steps, and the fourth step
The reception strength of the above antenna whose directivity has been changed by two steps
A fifth step of comparing the degree with the comparison object intensity;
In the comparison in step 5, the reception intensity after changing the pointing direction
When the reception strength is equal to or higher than the comparison target strength and lower than the predetermined strength,
Set the degree to the new comparison target intensity and return to the first step.
Sixth step and orientation control method for a mobile reception antenna which comprises a that. 3. The method according to claim 2, wherein the fifth step
Of the receiving strength after changing the pointing direction
Change the direction control of the antenna when the intensity is less than
The direction is specified in the opposite direction, and this new
One step in the direction of the antenna in the direction specified in
Seventh directivity direction control method for a mobile reception antenna, which comprises a step of only changed.