JP4835393B2 - Road-to-vehicle communication determination system and method, and determination device used therefor - Google Patents

Description

  The present invention relates to a road-to-vehicle communication determination system and method, and a determination apparatus used therefor, in which two-way communication is performed using an optical signal between an optical beacon installed on a roadside and an in-vehicle device mounted on a vehicle.

As a traffic information service using a road-to-vehicle communication system, so-called VICS (Vehicle Information and Communication System) using optical beacons, radio wave beacons or FM multiplex broadcasting has already been developed. Among these, the optical beacon employs optical communication using near infrared rays as a communication medium, and enables two-way communication with the in-vehicle device.
Specifically, uplink information including travel time information between beacons held by the vehicle is transmitted from the in-vehicle device to the optical beacon on the infrastructure side, and conversely, traffic jam information, section travel time information, event regulation information, and lanes Downlink information including notification information and the like is transmitted from the optical beacon to the vehicle-mounted device (see, for example, Patent Document 1).

The optical beacon includes a light projecting / receiving device (beacon head) that performs bidirectional communication with the vehicle-mounted device. The light projecting / receiving device includes a light emitting diode (LED) that transmits downlink information and a vehicle-mounted device. And a photo sensor for receiving the uplink information.
On the other hand, the in-vehicle device is also provided with a projector / receiver (vehicle-mounted head) having an LED and a photosensor in order to perform bidirectional communication with the projector / receiver of the optical beacon.
JP 2005-268925 A

In the road-to-vehicle communication system using the optical beacon, the optical beacon cannot receive the uplink information from the in-vehicle device, so the road-to-vehicle communication is not properly performed, and the vehicle may not be able to enjoy a predetermined service.
The cause is that if the photosensitivity of the photo sensor of the optical beacon projector / receiver decreases due to aging, the light receiving panel of the optical beacon projector / receiver becomes dirty and the light transmittance decreases, The signal is reflected in front of the projector / receiver of the in-vehicle device due to the deterioration of the light emitting diode of the projector / receiver of the vehicle due to aging, and the dirt on the windshield of the vehicle and the surrounding environment (rainfall, fog, etc.) It may be possible to

In this case, in the conventional road-to-vehicle communication system, even when the predetermined uplink information is not properly received due to the abnormality of the light receiver / receiver of the optical beacon, it is impossible to automatically detect the communication abnormality. In order to detect such communication anomalies, it was necessary for workers to visit all the optical beacons that make up the system to the site and inspect them manually.
Further, if the optical beacon does not properly receive the uplink information, the optical beacon switches the downlink and does not transmit the downlink information storing predetermined information to the in-vehicle device. In such a case, there is a risk that the vehicle will continue to travel as if an appropriate traffic information service has been obtained without the driver being aware of it.

On the other hand, a safe driving support system has been proposed in which signal information and distance information to a stop line are included as downlink information from an optical beacon, and vehicle braking control and deceleration instruction are performed using this information ( For example, Japanese Patent Application Nos. 2006-121692 and 2006-121700).
In the safe driving support system, when the uplink information for the optical beacon from the in-vehicle device has not been reached, the optical beacon cannot transmit the information for assisting operation such as the signal information to the in-vehicle device. Safe driving support operations such as warnings and brake control cannot be executed.

  In view of such circumstances, the present invention enables a system administrator to determine whether or not optical beacons need to be maintained by automatically determining whether road-to-vehicle communication is appropriate from the received contents of uplink information for a plurality of optical beacons. It is an object of the present invention to provide a road-to-vehicle communication determination system and method and a determination apparatus used therefor.

A road-to-vehicle communication determination system according to the present invention includes an in-vehicle device of a vehicle traveling on a road, and a projector / receiver in which a communication area is set in a predetermined range of the road, A determination system for road-to-vehicle communication comprising a plurality of optical beacons for performing communication and a determination device for determining a communication state of the road-to-vehicle communication, wherein the determination device uses the same vehicle ID transmitted by the in-vehicle device. A communication unit that receives uplink information including the plurality of optical beacons, and an uplink including the same vehicle ID in the optical beacons installed on the upstream side and the downstream side in the vehicle traveling direction in the plurality of optical beacons. when receiving the information, depending on whether the light beacon in the middle of the vehicle traveling direction is receiving uplink information including the same vehicle ID, the communication state of the light beacon in the middle And having a determination unit for determining whether.

According to this determination system, the communication unit of the determination device receives uplink information including the same vehicle ID transmitted from the in-vehicle device from the plurality of optical beacons, and the determination unit of the determination device includes the plurality of optical beacons. When the optical beacons installed on the upstream side and the downstream side in the vehicle traveling direction are receiving uplink information including the same vehicle ID , the optical beacon in the middle of the vehicle traveling direction is the same vehicle. Since whether or not the communication state of the intermediate optical beacon is determined is determined based on whether or not uplink information including the ID is received, the determination device automatically determines whether or not the road-to-vehicle communication performed by the specific optical beacon is performed. Can grasp.
For this reason, the system administrator can easily determine whether or not the optical beacon maintenance is necessary by providing the determination device with an output unit that notifies the system administrator of the suitability of the communication state determined by the determination unit.

In the determination system of the present invention, it is preferable that the determination device includes a stop unit that transmits operation stop information to the optical beacon that can be regarded as a communication abnormality from the determination result of the determination unit.
In this case, since the stop unit of the determination apparatus transmits the operation stop information to the optical beacon in which a communication abnormality has occurred or is highly likely, the operation of the optical beacon can be quickly stopped. The operation stop in this case includes not only the control so that the optical beacon does not operate at all, but also the case where the road-vehicle communication with the in-vehicle device is simply stopped, or specific information ( For example, the case where the transmission of the distance information to the stop line and the signal information) is simply stopped is also included.

Further, in the determination system of the present invention, if the determination device is provided with an output unit that notifies the system administrator of an optical beacon that can be regarded as a communication abnormality from the determination result of the determination unit, the system administrator The presence of an optical beacon can be immediately recognized.
As the output unit, a display that visually alerts a system administrator to an optical beacon that may have an abnormal communication state, a speaker device that alerts the optical beacon with sound, and the like can be employed.

The determination method of road-to-vehicle communication according to the present invention includes road-to-vehicle communication performed between an in-vehicle device of a vehicle traveling on a road and a plurality of optical beacon projectors and receivers in which a communication area is set in a predetermined range of the road. The uplink information including the same vehicle ID transmitted by the in-vehicle device is received from the plurality of optical beacons, and the upstream side and the downstream side in the vehicle traveling direction among the plurality of optical beacons, When the optical beacon installed in the vehicle receives uplink information including the same vehicle ID , is the optical beacon in the middle of the vehicle traveling direction receiving uplink information including the same vehicle ID? Whether or not the communication state of the optical beacon in the middle is determined based on whether or not it is.

In addition, the road-to-vehicle communication determination device of the present invention is a road that is performed between an in-vehicle device of a vehicle traveling on a road and a plurality of optical beacon projectors / receivers that have communication areas set in a predetermined range of the road. An inter-vehicle communication determination device, wherein a communication unit that receives uplink information including the same vehicle ID transmitted by the in-vehicle device from the plurality of optical beacons, and upstream in the vehicle traveling direction among the plurality of optical beacons When the optical beacons installed on the side and the downstream side receive uplink information including the same vehicle ID , the optical beacon in the middle of the vehicle traveling direction includes the same vehicle ID. And a determination unit that determines whether the communication state of the optical beacon in the middle is appropriate.

  According to these determination methods and apparatuses, uplink information including the same vehicle ID transmitted by the in-vehicle device is received from a plurality of optical beacons, and an optical beacon that is geographically intermediate among the plurality of optical beacons is a vehicle. Since whether or not the communication state of the optical beacon in the middle is determined based on whether or not uplink information including an ID is received, it is possible to automatically grasp the appropriateness of road-to-vehicle communication performed by a specific optical beacon. it can.

  As described above, according to the present invention, it is possible to determine whether road-to-vehicle communication is appropriate based on uplink information received from a plurality of optical beacons. In addition, by notifying the system administrator of the state of the road-to-vehicle communication, it is possible to easily determine whether or not the maintenance of the optical beacon is necessary.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[Overall system configuration]
FIG. 1 is a block diagram showing the overall configuration of a road-to-vehicle communication determination system according to the present invention.
As shown in FIG. 1, this road-to-vehicle communication determination system includes an infrastructure-side traffic control system 1 and an in-vehicle device 2 mounted on each vehicle C traveling on a road R. The traffic control system 1 includes a central device 3 having a function as a determination device provided in a control room, and optical beacons (optical vehicle detectors) 4 installed in many places on the road R. The optical beacon 4 performs bidirectional communication with the in-vehicle device 2 by optical communication using near infrared as a communication medium. The central device 3 is provided in the traffic control room.

[Configuration of central unit]
The central device 3 includes a communication unit 6 that is a communication interface connected to each optical beacon 4 via a communication line 5 such as a telephone line, a management computer 7 to which the communication unit 6 is connected, and system management of the control room. A display 8 and a speaker device 9 are provided as a human interface for a person.
The management computer 7 is a general-purpose large-sized computer (mainframe) having a CPU, a memory (RAM), and a storage device (ROM), and collects, processes and records various traffic information, controls signals, and provides information. Is going.

The management computer 7 also functions as a communication control unit that performs two-way communication with the optical beacon 4 via the communication unit 6, constantly transmits traffic jam information and regulation information to each optical beacon 4, and the vehicle C Is received from each optical beacon 4. The management computer 7 also functions as a drive control unit for the display 8 and the speaker device 9.
The display 8 has a display screen on which all traffic lights managed by the management computer 7 and the positions of the optical beacons 4 on the road map are displayed, and the lamp corresponding to the abnormal optical beacon 4 blinks. By doing so, the system administrator is notified of the abnormality of the optical beacon 4 and its position. In addition, the speaker device 9 notifies the system administrator of the occurrence of the abnormality of the optical beacon 4 simultaneously with voice.

  Further, the management computer 7 stores a program for executing predetermined functions related to the present invention in a storage device, and includes a determination unit 10, an identification unit 11, and a stop unit 12 as functional units to be executed by the program. ing. The processing contents of these functional units 10, 11, and 12 will be described later.

[Configuration of optical beacon]
The optical beacon 4 includes a communication unit 14 that is a communication interface connected to the central apparatus 3 via a communication line 5 such as a telephone line, a beacon controller 15 to which the communication unit 14 is connected, and the controller 15 A plurality of (four in the illustrated example) projector / receiver (beacon head) 16 connected to the sensor interface are provided.
Each projector / receiver 16 is configured by housing a light emitting diode (LED) 18 and a photosensor 19 inside a housing 17 (see FIG. 3). Among these, the LED 18 emits downlink information 26 and 28 made of near infrared rays to a communication area A described later, and the photosensor 19 receives uplink information 27 made of near infrared rays from the in-vehicle device 2.

FIG. 2 is a plan view of the optical beacon 4.
As shown in FIG. 2, the optical beacon 4 of this embodiment is installed on a road R having a plurality of lanes R1 to R4 (four in the illustrated example) in the same direction, and corresponds to each lane R1 to R4. The plurality of projectors / receivers 8 provided in this manner, and one beacon controller 15 serving as a control unit that collectively controls these projectors / receivers 8.
The beacon controller 15 is composed of a programmable microcomputer having a CPU, a memory (RAM), and a storage device (ROM). The beacon controller 15 is a two-way communication with the central device 3 by the communication unit 14 and the in-vehicle device 2 by each projector / receiver 16. It functions as a communication control unit that controls road-to-vehicle communication. The contents of road-to-vehicle communication by the beacon controller 15 will be described later.

The beacon controller 15 is installed on a support column 20 erected on the side of the road, and each projector / receiver 16 is attached to an installation bar 21 installed horizontally on the road R side from the support column 20, and each lane on the road R. Arranged immediately above R1 to R4.
The LED 18 of each projector / receiver 16 emits near-infrared light toward the upstream side of the lanes R <b> 1 to R <b> 4, and thereby a communication area for performing road-to-vehicle communication with the in-vehicle device 2. A is set on the upstream side (right side in FIG. 2) of the light emitter / receiver 16.

FIG. 3 is a side view showing the communication area A of the optical beacon 4.
As shown in FIG. 3, this communication area A is a downlink area (area provided with solid line hatching in FIG. 3) DA in which a light emitter / receiver 29 of the vehicle-mounted device 2 described later can receive downlink information. , And an uplink area (area provided with broken-line hatching in FIG. 3) UA from which the projector / receiver 16 of the optical beacon 4 can receive uplink information.

In the “near-infrared interface standard” of the optical beacon (optical vehicle detector) 4, the uplink area UA overlaps with the upstream part (right side part of FIG. 3) of the downlink area DA in the vehicle traveling direction, The upstream end c of the downlink area DA and the uplink area UA coincide with each other.
Therefore, the vehicle traveling direction length of the downlink area DA matches the same direction length of the entire communication area A.

In the above standard, in the case of the optical beacon 4 for general roads, the downstream end a of the downlink area DA is located 1.0 to 1.3 m upstream immediately below the light emitter / receiver 8, and the downlink area The distance from the downstream end a of the DA to the downstream end b of the uplink area UA is defined as 2.1 m, and the distance from the downstream end b of the uplink area UA to the upstream end c of the area UA is defined as 1.6 m. Has been. In this case, the total length of the communication area A in the vehicle traveling direction is 3.7 m.
However, the vehicle traveling direction lengths of the areas DA and UA are not limited to the above numerical values. Further, as indicated by a virtual line in FIG. 3, the upstream end c ′ of the downlink area DA may be positioned further upstream (right side in FIG. 3) than the upstream end c of the uplink area.

[Configuration of in-vehicle device]
The in-vehicle device 2 mounted on the vehicle C includes an in-vehicle computer 23 (see FIG. 4) and a projector / receiver (in-vehicle head: see FIGS. 3 and 4) 24 connected to the computer.
The projector / receiver 24 of the in-vehicle device 2 also includes a light emitting diode (LED) and a photosensor (not shown), like the projector / receiver (beacon head) 8 of the optical beacon 4. Among these, the LED emits uplink information 27 made of near infrared rays, and the photosensor receives downlink information 26 and 28 made of near infrared rays emitted to the communication area A. The in-vehicle computer 23 of the in-vehicle device 2 performs control processing for road-to-vehicle communication with the optical beacon 4 by the light projector / receiver 24.

[Processing contents of the management computer]
[Judgment processing for road-to-vehicle communication]
The management computer 7 of the central device 3 constantly collects and monitors the vehicle ID information included in the uplink information 27 from the in-vehicle device 2 received by all the optical beacons 4 managed by the central device 3 from each optical beacon 4. And the determination part 10 of the management computer 7 determines the propriety of the road-vehicle communication in the specific optical beacon 4 based on the vehicle ID information. Hereinafter, the determination process by the determination unit 10 will be described.

FIG. 5A shows an example of an actual installation position of the optical beacon 4, and FIG. 5B shows a position table created corresponding to the installation position of the optical beacon 4. As shown in FIG. 5A, it is assumed that optical beacons B1 to B4 are installed in that order from the upstream side to the downstream side of a certain main road R, respectively.
In the matrix constituting the position table shown in FIG. 5 (b), in the left column (beacon name), the optical beacons B1 to B4 are arranged in order from the top, and in the central column (upstream beacon) The optical beacons positioned upstream from the optical beacons B1 to B4 are arranged in order from the top, and the optical beacons positioned downstream from the optical beacons B1 to B4 are arranged in the right column (downstream beacons). They are arranged in order from the top.

For example, since there is no other optical beacon on the upstream side of the optical beacon B1, and there is an optical beacon B2 on the downstream side of the beacon B1, in the row of “B1” in the position table, the upstream beacon column Is “× (absent)” and the downstream beacon column is “B2”.
In addition, since the optical beacon B1 exists on the upstream side of the optical beacon B2 and the optical beacon B3 exists on the downstream side of the beacon B2, the upstream beacon column in the row of “B2” in the position table indicates “ “B1” and the downstream beacon column is “B3”.

In the following, in the “B3” row of the position table, the upstream beacon column is “B2” and the downstream beacon column is “B4”, and in the “B4” row of the position table, the upstream The column for the side beacon is “B3” and the column for the downstream beacon is “× (not present)”.
The management computer 7 stores in advance in the storage device the position table relating to all the optical beacons 4 installed on the road R that it has jurisdiction over.

Therefore, when the communication unit 6 of the computer 7 receives the same vehicle ID from any two optical beacons (for example, B1 and B3 in FIG. 5) within a predetermined time, the determination unit 10 of the management computer 7 It is determined based on the position table whether there is another optical beacon 4 between the two optical beacons B1 and B3.
If it is determined that there is a corresponding optical beacon 4 (for example, B2 in FIG. 5), the determination unit 10 determines whether or not the same vehicle ID is transmitted from the optical beacon B2 within a predetermined time. To monitor.

When the determination unit 10 of the management computer 7 does not receive the vehicle ID from the optical beacon B2 within a predetermined time, the determination unit 10 increments the “number of times of omission” of the vehicle ID in the optical beacon B2 by one. In addition, when the vehicle ID is normally received, the determination unit 10 increments the “number of receptions” in the optical beacon B2 by one.
Then, the determination unit 10 of the management computer 7 determines that the “missing frequency” of the vehicle ID exceeds a predetermined threshold value within a predetermined time or the “missing frequency” of the “reception frequency” of the vehicle ID is a predetermined ratio. When it is above, it determines with the road-to-vehicle communication of optical beacon B2 being bad (abnormal), and conversely, when that is not right, it determines with the road-to-vehicle communication of optical beacon B2 being favorable (normal).
Note that the position table need not be used as long as it indicates the geographical relationship between the installation points of the optical beacons. Further, the adjacent optical beacon may not be the upstream beacon or the downstream beacon. For example, “B4” may be used as the downstream beacon of the “B2” optical beacon, or the upstream beacon of “B3”. “B1” may be used.

Here, for example, consider determining whether the optical beacon B2 is in the road-to-vehicle communication state. In the upstream optical beacon B1, an uplink storing a certain vehicle ID is received, but when an uplink storing the vehicle ID is not received in the downstream optical beacon B3, the vehicle having the vehicle ID is B1 It is thought that the travel route was changed to a road other than the road R after passing through the point. In this case, it cannot be specified whether the vehicle has changed the travel route before the optical beacon B2 or has changed the travel route after passing through the optical beacon B2.
In this way, the road-to-vehicle communication state of the optical beacon located in the middle is determined by using both optical beacons instead of using the uplink received only in one of the upstream or downstream optical beacons. can do.

In addition, it is assumed that after the vehicle changes the travel route to a road other than the road R after passing through the optical beacon B1, the vehicle returns to the road R again and passes through the optical beacon B3. Further, it is only necessary to separately provide a time measuring means for monitoring the time when the uplink is received and calculating the required time between B1 and B3.
That is, since the required time between B1 and B3 can be estimated from the traveling speed of the vehicle on the road R and the distance between the optical beacons B1 and B3, the estimated time and the required time obtained by the time measuring means are different from each other by a predetermined amount or more. In the case of being present, the uplink can be prevented from being used for determination of the road-to-vehicle communication state of the optical beacon B2.

[Optical beacon operation stop processing]
As described above, the determination unit 10 of the management computer 7 determines whether or not the road-to-vehicle communication of the specific optical beacon 4 is appropriate. By performing the above determination on a plurality of vehicle ID information obtained from the plurality of vehicle-mounted devices 2. The road-to-vehicle communication state can be determined more accurately.
In other words, in the present embodiment, the identification unit 11 of the management computer 7 determines that the total communication abnormality rate related to a certain optical beacon 4 is greater than or equal to a predetermined threshold within a predetermined period for the vehicle IDs of the plurality of in-vehicle devices 2. The optical beacon 4 is identified as the optical beacon 4 having a communication abnormality.

In this case, road-to-vehicle communication using the optical beacon 4 is optical communication using near-infrared light, and therefore, the frequency of errors increases only during the daytime due to the influence of daytime sunlight, and the number of frames transmitted and received normally decreases. There is also. Therefore, it is preferable to determine whether or not communication is performed by the determination unit 10 for each time period, and to store the determination history for each time period in the storage device.
It is also possible to receive weather-related information from a weather information distribution server (not shown) of the Japan Meteorological Agency or a sensor (not shown) that detects the weather installed on the road and accumulate the information together. . For example, if the driver operates the wiper during rainy weather, an optical signal in road-to-vehicle communication may be temporarily interrupted by the wiper. It is considered that the probability of not reaching the beacon 4 is increased.

Further, for example, even when dense fog or the like occurs, it is considered that the optical signal emitted by the in-vehicle device 2 does not reach the optical beacon 4 and the probability that the optical beacon 4 cannot receive an uplink from the in-vehicle device 2 is increased. In this way, storing information related to the weather at the same time is useful because it is possible to analyze in detail the basis of changes in the actual measurement information 36.
The management computer 7 displays the position of the optical beacon 4 with the communication abnormality identified by the identification unit 11 on the display 8 of the central device 3 or outputs a sound from the speaker device 9 to detect the communication abnormality. The system administrator is notified of the presence and position of the optical beacon 4 that has been regarded.

Further, the stop unit 12 of the management computer 7 transmits operation stop information 33 (see FIG. 1) via the communication unit 6 to the optical beacon 4 having the communication abnormality specified by the identification unit 11. The beacon controller 15 of the optical beacon 4 that has received the operation stop information 33 ends the light emission and reception of the light projector / receiver 16 and immediately stops the operation of the optical beacon 4.
However, when the operation stop information 33 is received, in addition to controlling the optical beacon 4 not to operate at all as described above, the road-to-vehicle communication with the in-vehicle device 2 is simply stopped, or specific information For example, the transmission of the distance information to the stop line and the signal information to the in-vehicle device 2 may be stopped.

[Road-to-vehicle communication]
FIG. 4 shows a bidirectional road-to-vehicle communication procedure performed between the light projector / receiver 16 of the optical beacon 4 and the light projector / receiver 24 of the in-vehicle device 2 in the communication area A. Hereinafter, the contents of this road-to-vehicle communication will be described with reference to FIG.
First, the beacon controller 15 of the optical beacon 4 receives first downlink information 26 including lane notification information from each projector / receiver 16 corresponding to each lane R1 to R4 as first information before downlink switching. Is continuously transmitted to the downlink area DA of each lane R1 to R4 at a predetermined transmission cycle (F1 in FIG. 5). At this stage, the vehicle ID is not yet stored in the lane notification information.

When the vehicle C equipped with the vehicle-mounted device 2 enters the upstream portion of the downlink area DA, the light emitter / receiver 29 of the vehicle-mounted device 2 receives the first downlink information 26 including the lane notification information (no vehicle ID). .
At this time, the in-vehicle computer 23 of the in-vehicle device 2 recognizes that the vehicle C exists in the communication area A. Thereafter, the in-vehicle computer 23 starts transmission of the uplink information 27 (F2 in FIG. 5), and transmits this uplink information 27 to the projector / receiver 16 of the optical beacon 4 at a predetermined transmission cycle (in FIG. 5). F3).

The in-vehicle computer 23 transmits the uplink information 27 in the uplink area UA (see FIG. 3), stores the specific vehicle ID in the vehicle C in the uplink information 27, and transmits the uplink information 27. .
In addition, when the in-vehicle computer 23 has travel time information between beacons, this information is also included in the uplink information 27. Moreover, the vehicle-mounted computer 23 continues to transmit the uplink information 27 until it recognizes that the beacon controller 15 of the optical beacon 4 has switched the downlink.

On the other hand, when the projector / receiver 15 of the optical beacon 4 receives the uplink information 27 (F4 in FIG. 5), the beacon controller 15 has the vehicle ID information as the second information after the downlink switching. 2 starts transmission of the second downlink information 28 including the lane notification information for F2 (F5 in FIG. 5), and repeats the transmission of this downlink information 28 as much as possible within a predetermined time (F6 in FIG. 5). ).
The lane notification information includes a field for storing a vehicle ID for each lane R1 to R4, and a lane number can be assigned to each vehicle ID. For this reason, the in-vehicle computer 23 of each vehicle C traveling in different lanes R1 to R4 determines which lane R1 to R4 the host vehicle is in by determining which of the storage fields includes the vehicle ID of the host vehicle. Can recognize if you are driving.

The second downlink information 28 includes traffic information, section travel time information, event regulation information, support information for safe driving support for the driver, and the optical beacon 4 in addition to the lane notification information including the vehicle ID. The identification number etc. which identify are included.
The support information includes the signal information, which is timing information at which the downstream signal of the optical beacon 4 changes, and length information from the downlink area DA to a predetermined position (for example, a stop line) downstream of the optical beacon 4. The distance information etc. which are are included.

As shown in FIG. 4, the second downlink information 28 includes a single or a plurality of minimum frames 29. According to the “near infrared interface standard”, the data amount of the minimum frame 29 is defined as a total of 128 bytes, and 5 bytes are allocated to the header section 30 and 123 bytes are allocated to the actual data section 31.
According to the standard, the second downlink information 28 can be composed of 1 to 80 minimum frames 29, and the transmittable time is set to 250 ms. The downlink information 28 is composed of an arbitrary number of minimum frames 29 corresponding to the amount of information to be transmitted, and is repeatedly transmitted within the range of the transmittable time.

The transmission period of the minimum frame 29 is about 1 ms. Therefore, for example, when one downlink information 28 is constituted by three minimum frames 29, the transmission period of the downlink information 28 is about 3 ms. Therefore, the downlink information 28 has a predetermined transmittable time (250 m). ) Will be repeatedly transmitted about 80 times during this period.
The in-vehicle computer 23 of the in-vehicle device 2 recognizes the downlink switching in the optical beacon 4 at the time when the second downlink information 28 is received (F7 in FIG. 5), and at this time, transmits the uplink information 27. Stop.

  As described above, according to the determination system of the present embodiment, the communication unit 6 of the central device 3 receives the uplink information 27 including the same vehicle ID transmitted by the in-vehicle device 2 from the plurality of optical beacons 4, and Depending on whether the determination unit 10 of the device 3 receives the uplink information 27 including the vehicle ID, the optical beacon B2 that is geographically intermediate among the plurality of optical beacons B1 to B3 Since the suitability of the communication state of the beacon B2 is determined, the central device 3 can automatically grasp the suitability of the road-to-vehicle communication performed by the specific optical beacon 4.

Further, according to the determination system of the present embodiment, the system administrator is notified of the abnormality in the communication state determined by the determination unit 10 of the central device 3 through the display 8 or the speaker device 9 (output unit) of the central device 3. Therefore, the system administrator can easily determine whether the maintenance of the optical beacon 4 is necessary.
Furthermore, according to the determination system of the present embodiment, the optical beacon 4 having the communication abnormality determined by the determination unit 10 is notified to the system administrator by the display 8 or the speaker device 9. A person can immediately recognize the presence of the optical beacon 4 having a communication abnormality.

[Other Embodiments]
The present invention is not limited to the above embodiment.
For example, in the above-described embodiment, the central device 3 of the traffic control system 1 is adopted as a determination device that determines the suitability of road-to-vehicle communication. However, the determination device is another infrastructure that can communicate with a plurality of optical beacons 4. A control device (such as a signal controller) on the side can also be employed.

In addition, in order to accurately grasp whether or not road-to-vehicle communication is properly performed and perform maintenance, lane regulation or the like is performed on the road R where the optical beacon 4 is installed for a predetermined period, and the optical beacon 4 Therefore, it is necessary to measure the amount of light reaching from the vehicle, the light reception level of the optical signal from the vehicle-mounted device 2, and the like. However, performing lane restrictions and the like cause traffic congestion and require a large amount of cost.
Therefore, a maintenance vehicle (maintenance car) C mainly intended to cause the central device (determination device) 3 to determine the suitability of the road-to-vehicle communication state is provided. It is very useful if it is possible to determine the suitability of road-to-vehicle communication by passing under the light emitter / receiver 8 of the optical beacon 4 on the route to be judged as appropriate.

In this case, the vehicle ID of the maintenance car C is preferably defined as a maintenance car dedicated vehicle ID that is different from that of a general vehicle or the like.
Further, the determination device 3 extracts the uplink information storing the vehicle ID dedicated to the maintenance car from the large amount of uplink data received from the general vehicle or the like, and then uses the extracted data to determine the road-vehicle communication state. If the determination is made, the determination can be made efficiently, which is very useful.

Also, whether or not the planned travel route and planned travel time of the maintenance car C are stored in advance in the storage unit of the determination device 3 and the uplink information from the vehicle ID dedicated to the maintenance car matches the stored information. Thus, it is possible to determine whether road-to-vehicle communication is appropriate.
Since the maintenance car C travels for the purpose of determining the road-to-vehicle communication state, for example, the maintenance car C can travel in a specific lane in order or can travel while maintaining a predetermined speed. It can also be made to determine more accurately whether the inter-vehicle communication state is normal.

When the optical beacon 4 is continuously installed on the main road with a lot of traffic, it is considered very effective to introduce the determination system of the present invention. This is because, on a highway with a lot of traffic, the light receiving / emitting panel of the light emitting / receiving device 16 of the optical beacon 4 is very dirty, and it is necessary to perform maintenance at a short cycle.
Moreover, since it is considered that there are many drivers who expect the traffic information providing service by the optical beacon 4 on a highway with a large traffic volume, it is very useful to accurately determine whether maintenance is necessary.

  Further, on the road where the safe driving support system that receives the safe driving support information from the optical beacon 4 and performs brake control and warning to the driver on the vehicle C side is operated, the necessity of maintenance of the optical beacon 4 is determined. It is extremely important to judge. This is because the safe driving operation such as the brake control on the vehicle C side depends on the suitability of information provision from the optical beacon 4 to the vehicle C.

  In addition, each said embodiment is an illustration and is not restrictive. The scope of the present invention is defined by the claims, and all modifications within the scope equivalent to the configurations described therein are also included in the scope of the present invention.

It is a block diagram which shows the whole structure of the determination system of the road-vehicle communication of this invention. It is a top view of an optical beacon. It is a side view which shows the communication area | region of the said optical beacon. It is a conceptual diagram which shows the procedure and data content of the road-vehicle communication performed in a communication area. (A) is a schematic diagram which shows an example of the actual installation position of an optical beacon, (b) is a figure which shows the position table produced corresponding to the installation position of the optical beacon.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Traffic control system 2 Onboard machine 3 Central apparatus (judgment apparatus)
4 Optical beacon 6 Central unit communication unit 7 Management computer 8 Display (output unit)
9 Speaker device (output unit)
10 Judging Unit 11 Identification Unit 12 Stopping Unit 16 Light Emitter / Receiver (Beacon Side)
23 On-vehicle computer 29 Emitter / receiver (on-vehicle device side)
26 First downlink information 27 Uplink information 28 Second downlink information 33 Operation stop information A Communication area C Vehicle R Road DA Downlink area UA Uplink area

Claims (5)

An in-vehicle device of a vehicle traveling on a road, and a plurality of light beacons that have road-to-vehicle communication with the in-vehicle device having a projector / receiver in which a communication area is set in a predetermined range of the road; A determination system for road-to-vehicle communication comprising a determination device for determining a communication state of communication,
The determination device includes a communication unit that receives uplink information including the same vehicle ID transmitted by the in-vehicle device from the plurality of optical beacons, and an upstream side and a downstream side in the vehicle traveling direction among the plurality of optical beacons. When the optical beacon installed in and receives the uplink information including the same vehicle ID , the optical beacon in the middle of the vehicle traveling direction receives the uplink information including the same vehicle ID. And a determination unit that determines whether the communication state of the optical beacon in the middle is appropriate.   2. The road-to-vehicle communication determination system according to claim 1, wherein the determination device includes a stop unit that transmits operation stop information to the optical beacon that can be regarded as a communication abnormality from a determination result of the determination unit.   3. The road-to-vehicle communication determination system according to claim 1, wherein the determination device includes an output unit that notifies a system administrator of the optical beacon that can be regarded as a communication abnormality from the determination result of the determination unit. A determination method of road-to-vehicle communication performed between an in-vehicle device of a vehicle traveling on a road and a plurality of light beacon projectors / receivers in which a communication area is set in a predetermined range of the road,
Uplink information including the same vehicle ID transmitted by the in-vehicle device is received from the plurality of optical beacons, and the optical beacons installed on the upstream side and the downstream side in the vehicle traveling direction among the plurality of optical beacons. When receiving uplink information including the same vehicle ID, depending on whether an optical beacon in the middle of the vehicle traveling direction is receiving uplink information including the same vehicle ID, A determination method for road-to-vehicle communication, which determines whether or not a communication state of a certain optical beacon is appropriate. A determination device for road-to-vehicle communication performed between an in-vehicle device of a vehicle traveling on a road and a plurality of light beacon projectors / receivers in which a communication area is set in a predetermined range of the road,
A communication unit that receives uplink information including the same vehicle ID transmitted by the in-vehicle device from the plurality of optical beacons, and is installed on the upstream side and the downstream side in the vehicle traveling direction in the plurality of optical beacons . When the optical beacon receives uplink information including the same vehicle ID, whether or not the optical beacon in the middle of the vehicle traveling direction has received the uplink information including the same vehicle ID, The determination apparatus of the road-to-vehicle communication characterized by having the determination part which determines the suitability of the communication state of the said optical beacon in the middle.

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