JP6727109B2 - Communication control device, communication control method, and communication control program - Google Patents

Description

The present invention relates to a technique for selecting an antenna that communicates with a vehicle.

For example, in an ETC (Electronic Toll Collection) system, information necessary for a billing process is transmitted and received by wireless communication between an antenna arranged near a tollgate and an on-vehicle device mounted in a vehicle.
On a wide road such as a three-lane road, two antennas may be used because one antenna cannot cover the entire road.
For example, the antenna installed on the left covers the left lane and the left side of the central lane of the road, and the antenna installed on the right covers the right lane and the right side of the central lane. At this time, the left antenna and the right antenna communicate at different frequencies.
From the antenna installed on the left side, strong radio waves reach the left lane and the left side of the central lane. In addition, strong radio waves reach the right lane and the right side of the central lane from the antenna installed on the right side. The area where these strong radio waves arrive is called the communication area.
Also, weak radio waves reach the right lane from the antenna installed on the left side. Furthermore, weak radio waves reach the left lane from the antenna installed on the right side. The region where this weak radio wave arrives is called the unstable region.
Due to the influence of the timing of frequency selection of the vehicle-mounted device, the vehicle-mounted device may communicate with weaker radio waves (radio waves in the unstable region). In this case, a weak radio wave may cause a communication error.
In order to avoid such a communication error, in Patent Document 1 and Patent Document 2, as illustrated in FIG. 6, a radio wave absorber is installed at the road edge to prevent communication with a vehicle traveling in an adjacent lane. I am taking measures against it.

JP, 2003-123111, A JP, 2003-218581, A

However, the radio wave absorbers disclosed in Patent Document 1 and Patent Document 2 have a problem that the cost is high including the material and installation work.
Further, there is a problem that it is necessary to replace the electromagnetic wave absorber due to deterioration over time.

The present invention has as its main object to solve such a problem, and has as its main object to avoid a communication error between an antenna and a vehicle without using a radio wave absorber.

The communication control device according to the present invention,
From the first antenna for estimating the horizontal arrival angle of the radio wave transmitted from the vehicle traveling on the road, the first arrival angle that is the horizontal arrival angle of the radio wave estimated by the first antenna is calculated. From the second antenna that is notified and is arranged at a position different from that of the first antenna and that estimates the horizontal arrival angle of the radio wave, the horizontal arrival angle of the radio wave estimated by the second antenna A vehicle position estimation unit that is notified of a certain second arrival angle and that estimates the position of the vehicle based on the notified first arrival angle and the second arrival angle,
An antenna selection unit that selects, from the first antenna and the second antenna, an antenna having better communication quality in communication with the vehicle, based on the position of the vehicle estimated by the vehicle position estimation unit; Have.

In the present invention, the position of the vehicle is estimated based on the arrival angle estimated by each antenna, and the antenna having better communication quality is selected based on the estimated position of the vehicle. Therefore, according to the present invention, it is possible to avoid a communication error between the antenna and the vehicle without using the radio wave absorber.

FIG. 3 is a diagram illustrating a positional relationship among a communication control device, an antenna, a lane, and a vehicle according to the first embodiment. FIG. 3 is a diagram illustrating a communication area and an unstable area according to the first embodiment. FIG. 3 is a diagram showing a configuration example of a communication control device according to the first embodiment. FIG. 3 is a diagram illustrating a vehicle position estimation principle according to the first embodiment. 3 is a flowchart showing an operation example of the communication control device according to the first embodiment. The figure explaining the positional relationship of an antenna, a radio wave absorber, a communication area, and an unstable area. The figure explaining the estimation method of a vehicle position. The figure explaining the estimation method of a vehicle position. The figure explaining the estimation method of a vehicle position. The figure explaining the estimation method of a vehicle position.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description of the embodiments and the drawings, the same reference numerals denote the same or corresponding portions.

Embodiment 1.
***Composition explanation***
FIG. 1 shows the positional relationship among the communication control device 100, antenna A201, antenna B202, lane, and vehicle 300 according to the present embodiment.
In the following, the three-lane road shown in FIG. 1 will be described as an example. In the three-lane road shown in FIG. 1, there are three traveling lanes, lane 1, lane 2, and lane 3.
In FIG. 1, the vehicle 300 is traveling in the lane 3. An in-vehicle device is mounted on the vehicle 300. The vehicle-mounted device communicates with the antenna A201 or the antenna B202. The communication of the vehicle-mounted device with the antenna A201 or the antenna B202 is also referred to as the communication of the vehicle with the antenna A201 or the antenna B202.
In the three-lane road of FIG. 1, two antennas (antenna A201 and antenna B202) cover the entire width of the road. That is, the antenna A201 and the antenna B202 are arranged at different positions, the antenna A201 covers the left side of the lane 1 and the lane 2, and the antenna B202 covers the right half of the lane 2 and the lane 3.
The communication area A which is the communication area of the antenna A201, the communication area B which is the communication area of the antenna B202, the unstable area A which is the unstable area of the antenna A201, and the unstable area B of the antenna B202 are as shown in FIG. It is distributed.
Good quality communication is possible within the communication area. In unstable areas, communication may or may not be possible with onboard equipment. That is, sufficient communication quality cannot be secured in the unstable region.

Although it is desirable that the vehicle 300 running in the lane 3 communicate with the antenna 2, the lane 3 also has an unstable area A. There may be communication.
In this case, the vehicle 300 may fail to secure sufficient communication quality with the antenna A201, resulting in a communication error.

Antenna A201 and antenna B202 according to the present embodiment each estimate the arrival angle in the horizontal direction of the radio wave transmitted from traveling vehicle 300. The arrival angle estimated by the antenna A201 is called an angle A (first arrival angle example), and the arrival angle estimated by the antenna B202 is called an angle B (second arrival angle example).
The antenna A 201 and the antenna B 202 notify the communication control device 100 of the estimated arrival angles as angle information.
The communication control device 100 estimates the position of the vehicle 300 based on the angle information. Then, the communication control device 100 selects an antenna having better communication quality in communication with the vehicle 300 from the antennas A201 and B202 based on the estimated position of the vehicle 300. More specifically, communication control device 100 selects an antenna in which the estimated position of vehicle 300 is included in the communication area.
Then, the communication control device 100 transmits a communication control instruction for permitting communication with the vehicle 300 to the selected antenna. Further, the communication control device 100 transmits a communication control instruction for prohibiting communication with the vehicle 300 to the antenna not selected.
As a result, only the antenna selected by the communication control device 100 communicates with the vehicle 300.
The operation performed by the communication control device 100 corresponds to a communication control method and a communication control program.

FIG. 3 shows a configuration example of the communication control device 100 according to the present embodiment.
The communication control device 100 is a computer, and includes a processor 91 and a storage device 92 as a hardware configuration.
Further, the communication control device 100 includes a communication unit A101, a communication unit B102, a vehicle position estimation unit 103, and an antenna selection unit 104 as functional configurations.
The storage device 92 stores programs that realize the functions of the communication unit A101, the communication unit B102, the vehicle position estimation unit 103, and the antenna selection unit 104.
Then, the processor 91 executes these programs to operate the communication unit A101, the communication unit B102, the vehicle position estimation unit 103, and the antenna selection unit 104, which will be described later.
FIG. 3 schematically shows a state in which the processor 91 is executing a program that realizes the functions of the communication unit A101, the communication unit B102, the vehicle position estimation unit 103, and the antenna selection unit 104.

The communication unit A101 receives angle information from the antenna A201, and also transmits a communication control instruction to the antenna A201.
The communication unit B102 receives the angle information from the antenna B202, and also transmits a communication control instruction to the antenna B202.

The vehicle position estimation unit 103 estimates the position of the vehicle 300 based on the angle A estimated by the antenna A201 and the angle B estimated by the antenna B202. More specifically, as shown in FIG. 4, the vehicle position estimating unit 103 defines an intersection of a straight line drawn at an angle A from the position of the antenna A201 and a straight line drawn at an angle B from the position of the antenna B202, The position of the vehicle 300 is estimated. The angles A and B are the arrival angles in the horizontal direction of the radio waves transmitted from the vehicle 300, as described above.
The operation performed by the vehicle position estimation unit 103 corresponds to the vehicle position estimation step.

The antenna selection unit 104 selects an antenna having better communication quality in communication with the vehicle 300 from the antennas A201 and B202 based on the position of the vehicle 300 estimated by the vehicle position estimation unit 103. More specifically, the antenna closer to the position of the vehicle 300 in the width direction of the road estimated by the vehicle position estimation unit 103 is selected. That is, if the antenna is located near the position of the vehicle 300 in the width direction of the road, it is possible to communicate with the vehicle 300 in the communication area. By selecting the antennas that are arranged close to each other, the antenna having better communication quality can be selected. In the example of FIG. 1, since the antenna B202 is closer to the position of the vehicle 300 in the width direction, the antenna selection unit 104 determines that the antenna B202 has better communication quality and selects the antenna B202. ..
Then, antenna selection section 104 transmits a communication control instruction that permits communication with vehicle 300 to the selected antenna, and transmits a communication control instruction that prohibits communication with vehicle 300 to the antenna that is not selected.
In the case of FIG. 1, the antenna selection unit 104 transmits a communication control instruction for prohibiting communication with the vehicle 300 to the antenna A201 and a communication control instruction for permitting communication with the vehicle 300 to the antenna A201. As a result, the vehicle 300 can secure sufficient communication quality with the antenna B202.
The operation performed by the antenna selection unit 104 corresponds to the antenna selection step.

***Description of operation***
FIG. 5 shows an operation example of the communication control device 100 according to the present embodiment.
Hereinafter, an operation example of the communication control device 100 will be described with reference to FIG.

First, the communication unit A101 receives angle information indicating the angle A from the antenna A201 (step S501). The communication unit A101 outputs the received angle information to the vehicle position estimation unit 103.
Next, the communication unit B102 receives the angle information indicating the angle B from the antenna B202 (step S502). The communication unit B102 outputs the received angle information to the vehicle position estimation unit 103.
Note that, here, although an example in which the communication unit B101 receives the angle information from the antenna B202 after the communication unit A101 receives the angle information from the antenna A201, the communication unit B102 first receives the angle information from the antenna B202. Good. Further, the communication unit A101 and the communication unit B102 may simultaneously receive the angle information.

Next, the vehicle position estimation unit 103 estimates the position of the vehicle 300 based on the angle A indicated by the angle information from the antenna A201 and the angle B indicated by the angle information from the antenna B202 (step S504).
That is, the position of the vehicle 300 is estimated by performing the geometric calculation as shown in FIG.
The vehicle position estimation unit 103 outputs the estimated position of the vehicle 300 to the antenna selection unit 104.

Next, the antenna selection unit 104 selects an antenna that communicates with the vehicle 300 based on the estimated position of the vehicle 300 obtained by the vehicle position estimation unit 103 (step S504).
When the antenna A201 is selected (YES in step S505), the antenna selection unit 104 transmits a communication control instruction permitting communication of the antenna A201 from the communication unit A101 to the antenna A201 (step S506).
Further, the antenna selection unit 104 transmits a communication control instruction to prohibit the communication of the antenna B202 from the communication unit B102 to the antenna B202 (step S507).
On the other hand, when the antenna B202 is selected (NO in step S505), the antenna selection unit 104 transmits a communication control instruction permitting communication of the antenna B202 from the communication unit B102 to the antenna B202 (step S508).
Further, the antenna selection unit 104 transmits a communication control instruction to prohibit the communication of the antenna A201 from the communication unit A101 to the antenna A201 (step S509).

Here, a method of estimating the position of the vehicle 300 in step S504 will be described.

For example, when the angle estimation is estimated by using the phase difference in each antenna, the following relationship is given to the phase difference Δα when considering the coordinate system of FIG. 7.
sin θ·sin φ=Δα·λ/2π/d Equation 1
(D: Distance between antennas used inside each antenna)
The optical path difference between the antennas separated by d on the y-axis is as follows.
Optical path difference: d·sin θ·sin φ (approximate value when R is large)
Here, as shown in FIG. 10, the position of the vehicle 300 (vehicle-mounted device) is located 4 to 5 m below the antenna. Therefore, the range is 4≦Z≦5. In addition, considering that the communication area of the antenna is 20 m or less at the maximum (x-axis direction) and communication must be started at the position of 4 m, and the road width is about 3.5 m (y-axis direction), θ is 80. It is in the range of ° to 30 °.
Since it is when θ is large that the radio wave is first captured, when θ is 80° and 70°, φ1 (antenna 1) and φ2 (antenna 2) are first obtained from Expression 1.
Then, x, y, and z are as follows.
y=(tan(π/2−φ2)+tan(π/2−φ1))/(tan(π/2−φ2)−tan(π/2−φ1))
x=tan(π/2−φ1)(y−D/2)
z=r/tan θ
The position of the vehicle 300 (vehicle-mounted device) can be estimated by changing θ in this equation and determining where z is at a position of 4 to 5 m.

Example 1
When the distance between the antenna 1 and the antenna 2 is 3.5 m and the position of the vehicle-mounted device is (x, y, z)=(15, 5, 5), θ is in the range of FIG. ..
It can be estimated that y is about 5 m when θ is in the range of 77.5° to 70°.

Example 2
When the distance between the antenna 1 and the antenna 2 is 3.5 m and the position of the vehicle-mounted device is (x, y, z)=(10, 5, 5), θ is in the range of FIG. 9. ..
When θ is in the range of 72.5° to 62.5°, y can be estimated to be about 4.8 m.

***Explanation of the effect of the embodiment***
As described above, in the present embodiment, the intersection of the arrival angles estimated by the antennas can be estimated as the radio wave emission point=vehicle. Then, it is possible to select an antenna that does not cause a communication error based on the estimated position of the vehicle. Therefore, according to the present embodiment, it is possible to avoid a communication error between the antenna and the vehicle without using the radio wave absorber.
As a method of estimating the arrival angle, it is possible to estimate the angles in two directions, horizontal and vertical, with one antenna, but in this case, the angle accuracy of each is required. However, by estimating the arrival angle in the horizontal direction at a distant place as in the present embodiment, it is possible to improve the position estimation accuracy of the vehicle even if the demand for the angle accuracy is reduced.

100 communication control device, 101 communication unit A, 102 communication unit B, 103 vehicle position estimation unit, 104 antenna selection unit, 201 antenna A, 202 antenna B, 300 vehicle.

Claims (7)

From the first antenna for estimating the horizontal arrival angle of the radio wave transmitted from the vehicle traveling on the road, the first arrival angle that is the horizontal arrival angle of the radio wave estimated by the first antenna is calculated. From the second antenna that is notified and is arranged at a position different from that of the first antenna and that estimates the horizontal arrival angle of the radio wave, the horizontal arrival angle of the radio wave estimated by the second antenna It is notified certain second arrival angle, a straight line drawn at the second arrival angle from the position of the first of said first arrival angle drawn straight line and the second antenna from the position of the antenna A vehicle position estimating unit that estimates the intersection of the position of the vehicle,
An antenna selection unit that selects, from the first antenna and the second antenna, an antenna having better communication quality in communication with the vehicle, based on the position of the vehicle estimated by the vehicle position estimation unit; A communication control device having. From the first antenna for estimating the horizontal arrival angle of the radio wave transmitted from the vehicle traveling on the road, the first arrival angle that is the horizontal arrival angle of the radio wave estimated by the first antenna is calculated. From the second antenna that is notified and is arranged at a position different from that of the first antenna and that estimates the horizontal arrival angle of the radio wave, the horizontal arrival angle of the radio wave estimated by the second antenna A vehicle position estimation unit that is notified of a certain second arrival angle and that estimates the position of the vehicle based on the notified first arrival angle and the second arrival angle,
Said first antenna and one of the second antenna, the communication control device having a said antenna selecting unit for selecting a closer antenna to the position of the vehicle in the width direction of the road estimated by the vehicle position estimating section .. The antenna selection unit,
The communication control according to claim 1 or 2 , wherein a communication control instruction for permitting communication with the vehicle is transmitted to the selected antenna, and a communication control instruction for prohibiting communication with the vehicle is transmitted to the antenna not selected. apparatus. A computer estimates a horizontal arrival angle of a radio wave transmitted from a vehicle traveling on a road from a first antenna to a first arrival angle which is a horizontal arrival angle of the radio wave estimated by the first antenna; From the second antenna which is notified of the arrival angle and is arranged at a position different from that of the first antenna and estimates the horizontal arrival angle of the radio wave, the horizontal direction of the radio wave estimated by the second antenna is detected. A second arrival angle, which is an arrival angle, is notified , and a straight line drawn at the first arrival angle from the position of the first antenna and a second arrival angle drawn from the position of the second antenna are drawn. A vehicle position estimation step of estimating the intersection with the straight line as the position of the vehicle,
The computer selects, from the first antenna and the second antenna, an antenna having a better communication quality in communication with the vehicle, based on the position of the vehicle estimated by the vehicle position estimating step. A communication control method comprising: an antenna selecting step. A computer estimates a horizontal arrival angle of a radio wave transmitted from a vehicle traveling on a road from a first antenna to a first arrival angle which is a horizontal arrival angle of the radio wave estimated by the first antenna; From the second antenna which is notified of the arrival angle and is arranged at a position different from that of the first antenna and estimates the horizontal arrival angle of the radio wave, the horizontal direction of the radio wave estimated by the second antenna is detected. A vehicle position estimation step of notifying a second arrival angle that is an arrival angle, and estimating the position of the vehicle based on the notified first arrival angle and the second arrival angle,
The computer is, among the first antenna and the second antenna, and an antenna selection step of selecting a closer antenna to the position of the vehicle in the width direction of the road estimated by the vehicle position estimating step A communication control method having. From the first antenna for estimating the horizontal arrival angle of the radio wave transmitted from the vehicle traveling on the road, the first arrival angle that is the horizontal arrival angle of the radio wave estimated by the first antenna is calculated. From the second antenna that is notified and is arranged at a position different from that of the first antenna and that estimates the horizontal arrival angle of the radio wave, the horizontal arrival angle of the radio wave estimated by the second antenna It is notified certain second arrival angle, a straight line drawn at the second arrival angle from the position of the first of said first arrival angle drawn straight line and the second antenna from the position of the antenna A vehicle position estimation step of estimating the intersection point of the vehicle position and the vehicle position;
An antenna selecting step of selecting, from the first antenna and the second antenna, an antenna having a better communication quality in communication with the vehicle, based on the position of the vehicle estimated in the vehicle position estimating step; A communication control program that causes a computer to execute. From the first antenna for estimating the horizontal arrival angle of the radio wave transmitted from the vehicle traveling on the road, the first arrival angle that is the horizontal arrival angle of the radio wave estimated by the first antenna is calculated. From the second antenna that is notified and is arranged at a position different from that of the first antenna and that estimates the horizontal arrival angle of the radio wave, the horizontal arrival angle of the radio wave estimated by the second antenna A vehicle position estimation step of notifying a certain second arrival angle, and estimating the position of the vehicle based on the notified first arrival angle and the second arrival angle,
Among the first antenna and the second antenna, to perform the antenna selection step of selecting a closer antenna to the position of the vehicle in the width direction of the road estimated by the vehicle position estimation step in the computer Communication control program.

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