JP4867623B2 - Road-to-vehicle communication system, and optical beacon, in-vehicle device, and vehicle used therefor - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a road-to-vehicle communication system that performs bidirectional communication using an optical signal between an optical beacon installed on a roadside and an in-vehicle device mounted on the vehicle, and an optical beacon, an in-vehicle device, and a vehicle used therefor. It is.

As a traffic information service using a road-to-vehicle communication system, so-called VICS (registered trademark) (Vehicle Information and Communication System) using optical beacons, radio 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 bidirectional communication with the in-vehicle device is possible.
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.
The light beacon projector / receiver is attached to a construction bar installed horizontally on the road side from a support column standing on the side of the road, and is disposed immediately above the lane of the road. This projector / receiver is attached to the road so that it faces the upstream side in the vehicle traveling direction, so that the predetermined range on the upstream side in the vehicle traveling direction from the installation position of the projector / receiver is set as the communication area. Yes.
JP 2005-268925 A

In the road-to-vehicle communication system using the above-described optical beacon, information cannot be appropriately transmitted and received between the optical beacon and the in-vehicle device, and the in-vehicle device side may not be able to enjoy a predetermined service.
This is because optical beacons are easily affected by sunlight depending on the installation location and installation environment. For example, as shown in FIG. 7, in a lane having a traveling direction that faces north, conventionally, the light emitter / receiver 41 of the optical beacon 40 is installed in the south direction with respect to the road R. In addition, a communication area A is set on the south side. For this reason, particularly in the evening time zone, sunlight reflected on the road surface (solid line arrow in FIG. 7) is likely to enter the photosensor 42 of the light projecting / receiving device 41 of the optical beacon 40 and a reception error occurs on the optical beacon 40 side. It becomes easy.

On the contrary, in the lane with the south direction as the travel direction, the communication area A is set on the north side of the installation position of the light emitting / receiving device 41 of the optical beacon 40. And communication is performed between the vehicle equipment 2 mounted in the vehicle C which runs south. In this case, sunlight easily enters the photosensor of the light projector / receiver of the in-vehicle device 43 (broken arrow in FIG. 7), and a reception error is likely to occur on the in-vehicle device 43 side.
As described above, conventionally, the light beacon light emitter / receiver is installed in a direction facing the vehicle, the upstream side in the vehicle traveling direction is set as a communication area, and sunlight is transmitted to the photosensor of the light emitter / receiver. There is a problem that many communication errors occur due to incidence.

  In view of such circumstances, the present invention provides a road-to-vehicle communication system capable of reducing communication errors caused by the incidence of sunlight, and an optical beacon, an in-vehicle device, and a vehicle used therefor.

The road-to-vehicle communication system of the present invention includes an in-vehicle device for a vehicle traveling on a road, and a plurality of optical beacons each having a light emitter / receiver in which a communication area is set in a predetermined range of the road. A road-to-vehicle communication system that performs two-way communication with an optical signal between a machine and the optical beacon, wherein the plurality of optical beacons has a first communication region in an upstream range in a vehicle traveling direction from an installation position An optical beacon having a set first light emitter / receiver, an optical beacon having a second light emitter / receiver in which a range including a portion immediately below the installation position is set as a second communication area, and a vehicle traveling direction more than the installation position It consists of at least two types of optical beacons and a beacon having a third projector / receiver whose downstream range is set as the third communication region, and the at least two types of optical beacons include reflection of sunlight, etc. of Contains light beacon having the emitter and receiver of the communication area at a position hardly disturbed receiving the uplink beam is set in sound.

According to this road-to-vehicle communication system, the plurality of optical beacons includes an optical beacon having a first light emitter / receiver in which a range upstream of the installation position in the vehicle traveling direction is set as a first communication region, An optical beacon having a second light emitter / receiver in which the range including the portion immediately below is set as the second communication region, and a third light projector / receiver in which the range downstream in the vehicle traveling direction from the installation position is set as the third communication region Since the optical beacon has at least two types of optical beacons, the communication area of the optical beacon is set according to the location and environment where each optical beacon is installed. By setting the range upstream of the vehicle travel direction, the range including the portion immediately below the installation position of the light emitter / receiver, or the range downstream of the light transmitter / receiver installation position , Thick A light beacon having emitter and receiver of the communication area is set to effect hardly position where the light receiving is prevented uplink light such as reflection light.

The at least two types of optical beacons include an optical beacon having the light emitter / receiver in which the communication area is set at a position where it is difficult to prevent the reception of uplink light due to the reflection of sunlight or the like. Therefore, it is possible to reduce communication errors that occur due to the incidence of sunlight.

  In this case, it is preferable that the in-vehicle device has a projector / receiver directed in a direction in which communication can be performed with at least two types of the optical beacons. According to this, the vehicle-mounted device can communicate with each of at least two types of optical beacons having different communication areas.

Further, in this road-to-vehicle communication system, each of the optical beacons includes a plurality of projectors / receivers in which a plurality of different ranges are set as communication areas with respect to the vehicle traveling direction of the road, and the plurality of projectors / receivers It is preferable to have a selection unit that selects at least one projector / receiver to communicate with the vehicle-mounted device.
According to this, according to the place and environment where each optical beacon is installed, the selection unit selects the optical beacon transmitter / receiver to be communicated with the vehicle-mounted device, so that a communication region that is not easily affected by the incidence of sunlight can be obtained. You can choose. Thereby, the communication error which generate | occur | produces by incidence | injection of sunlight can be reduced.

The optical beacon of the present invention is an optical beacon used for road-to-vehicle communication that performs bidirectional communication using an optical signal with an in-vehicle device of a vehicle, and has an upstream range in the vehicle traveling direction from the installation position. The first light emitter / receiver set as one communication area, the second light emitter / receiver set as a second communication area in a range including the portion immediately below the installation position, and the range downstream of the installation position in the vehicle traveling direction At least two of the third projector / receiver set as the third communication area, and at least one of the at least two projector / receiver to communicate with the in-vehicle device is selected And a selection unit.

According to this optical beacon, the first projector / receiver in which the upstream range in the vehicle traveling direction from the installation position is set as the first communication area, and the range including the portion immediately below the installation position is set as the second communication area And at least two of the second projector / receiver and the third projector / receiver in which the downstream side in the vehicle traveling direction from the installation position is set as the third communication region. Depending on the location and environment where the beacon is installed, the communication area of the light beacon transmitter / receiver is set to the range upstream of the projector / receiver installation position in the vehicle traveling direction, or directly below the projector / receiver installation position. Or a range on the downstream side in the vehicle traveling direction from the installation position of the projector / receiver.

Then, the selection unit selects at least one of the at least two projectors / receivers to be communicated with the vehicle-mounted device. Thereby, according to the place and environment where an optical beacon is installed, it is possible to select a communication region that is not easily affected by the incidence of sunlight by selecting an optical beacon projector / receiver. Thereby, the communication error which generate | occur | produces by incidence | injection of sunlight can be reduced.

Further, the present invention is an in-vehicle device for a vehicle traveling on a road, and a plurality of ranges different from each other with respect to the vehicle traveling direction of the road are ranges upstream of the optical beacon installation position, the optical beacon installation position Two-way communication with an optical beacon having a plurality of light emitters / receivers set as a communication area in a range including a portion directly below and a range downstream of the installation position in the vehicle traveling direction. An in-vehicle device used for road-to-vehicle communication, having a plurality of in-vehicle side light emitters / receivers capable of communicating with each of the plurality of light beacon side light emitters / receivers, The side light emitter / receiver includes at least one light beacon side light emitter / receiver in which a range that is not easily affected by the incidence of sunlight among the plurality of light beacon side light emitters / receivers is set as a communication area. Between Directed towards that can be includes the emitter and receiver.

According to this vehicle-mounted device, at least one of the plurality of communication areas set in the plurality of light receivers / receivers of the optical beacon is set as a range that is not easily affected by the incidence of sunlight, and the communication area When the vehicle-mounted device performs communication in, communication errors that occur due to the incidence of sunlight can be reduced.

Their, it is possible to configure the vehicle body, and a control unit for controlling the vehicle driving and braking, the vehicle of the present invention by providing a on-board the vehicle device to said vehicle body.

  According to the present invention, the communication area can be set within a range that is not easily affected by the incidence of sunlight according to the installation location and the installation environment of the optical beacon, thereby reducing communication errors caused by the incidence of sunlight. can do.

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-vehicle communication system including an optical beacon according to the present invention.
As shown in FIG. 1, the road-to-vehicle communication system includes an infrastructure-side traffic control system 1 and an in-vehicle device 2 mounted on each vehicle C traveling on the road. The traffic control system 1 includes a central device 3 provided in a control room and a large number of optical beacons (optical vehicle detectors) 4 installed at various locations on the road. Two-way communication is performed with the in-vehicle device 2 by optical communication using as a communication medium. The central device 3 is provided in the traffic control room.

[Configuration of optical beacon]
FIG. 2 is a schematic configuration diagram of the optical beacon 4 and the in-vehicle device 2.
1 and 2, each optical beacon 4 includes a communication unit 6 that is a communication interface connected to the central device 3 via a communication line 5 such as a telephone line, and beacon control to which the communication unit 6 is connected. And a projector / receiver unit 9 that is a set of a plurality of projectors / receivers (beacon heads) 8 connected to the sensor interface of the controller 7. In the illustrated example, one projector / receiver unit 9 includes three projectors / receivers 8a, 8b, 8c. A first projector / receiver 8a, a second projector / receiver 8b, and a third projector / receiver 8c are provided side by side from the upstream side in the vehicle traveling direction, and are configured as an integrated projector / receiver unit 9.

FIG. 3 is a side view showing the optical beacon 4 and its communication area.
Each of the light emitters / receivers 8a, 8b, and 8c is configured by housing a light emitting diode (LED) 10 and a photosensor (light receiving element) 11 in a housing. Among them, the LED 10 emits downlink information (downlink light) made of near infrared rays to a communication area to be described later, and the photosensor 11 receives uplink information (uplink light) made of near infrared rays from the in-vehicle device 2. Receive light.

FIG. 4 is a plan view of the optical beacon 4 of FIG.
As shown in FIG. 4, the optical beacon 4 of the present embodiment is installed on a road R having a plurality of (four in the illustrated example) lanes R1 to R4 that have the same vehicle traveling direction. The plurality of projector / receiver units 9 provided corresponding to R4, and one beacon controller 7 serving as a control unit that collectively controls the projectors / receivers 8a, 8b, and 8c included in the projector units 9 respectively. And.

The beacon controller 7 is installed on a support column 12 erected on the side of the road, and each projector / receiver unit 9 is attached to an installation bar 13 installed horizontally on the road R side from the support column 12. It is arranged directly above the lanes R1 to R4.
In FIG. 2, a beacon controller 7 is composed of a programmable microcomputer having a CPU, a memory (RAM), and a storage device (ROM), and performs bidirectional communication with the central device 3 by the communication unit 6 and light projectors / receivers 8a and 8b. , 8c functions as a communication control unit that controls road-to-vehicle communication with the in-vehicle device 2. Further, the beacon controller 7 stores a program for executing each predetermined function in a storage device, and includes a selection unit 25 as a function unit to be executed by this program. The processing content by the selection unit 25 of the beacon controller 7 will be described later.

[Communication area]
As shown in FIGS. 3 and 4, in each projector / receiver unit 9 provided in each of the lanes R1 to R4, the LED 10 of the first projector / receiver 8a is installed at the position of the first projector / receiver 8a. Near-infrared light is emitted toward the upstream side in the vehicle traveling direction from directly below the vehicle. Further, the photosensor 11 of the first light projecting / receiving device 8a receives the near-infrared light of the in-vehicle device 2 sent from a position upstream in the vehicle traveling direction from directly below the installation position of the first light projecting / receiving device 8a. Is directed to. Thus, in the first light projecting / receiving device 8a, the first communication area A1 for performing road-to-vehicle communication with the in-vehicle device 2 is upstream of the installation position of the first light projecting / receiving device 8a in the vehicle traveling direction. (The right side of FIG. 3, the right side of FIG. 4) is set.

  The LED 10 of the second light emitter / receiver 8b emits near-infrared light directly below the installation position of the second light emitter / receiver 8b. Further, the photosensor 11 of the second light projecting / receiving device 8b is directed in a direction immediately below the installation position of the second light projecting / receiving device 8b. Thereby, in the second light projecting / receiving device 8b, the second communication area A2 for performing road-to-vehicle communication with the in-vehicle device 2 is set to a range including a portion directly below the installation position of the second light projecting / receiving device 8b. Has been.

The LED 10 of the third light projecting / receiving device 8c emits near infrared rays toward the downstream side in the vehicle traveling direction rather than directly below the installation position of the third light projecting / receiving device 8c. Further, the photosensor 11 of the third light emitter / receiver 8c receives the near infrared ray of the in-vehicle device 2 sent from a position downstream of the vehicle traveling direction from directly below the installation position of the third light emitter / receiver 8c. Is directed to. As a result, in the third projector / receiver 8c, the third communication region A3 for performing road-to-vehicle communication with the in-vehicle device 2 is downstream of the installation position of the third projector / receiver 8c in the vehicle traveling direction. (The left side of FIG. 3 and the left side of FIG. 4) are set.
In addition, at least one of the first communication area A1, the second communication area A2, and the third communication area A3 is prevented from receiving uplink light from the in-vehicle device 2 due to the influence of sunlight (such as reflection). It is set so that it is difficult to be placed.

  As shown in FIG. 3, each of the communication areas A1, A2, and A3 is provided with a downlink area (a solid line hatching is provided in FIG. 3) in which a projector / receiver of the vehicle-mounted device 2 described later can receive downlink information. Regions) DA1, DA2, DA3, and uplink regions in which the light emitters / receivers 8a, 8b, 8c of the optical beacon 4 can receive uplink information (regions provided with dashed hatching in FIG. 3) UA1, UA2 , UA3.

  In the "near-infrared interface standard" of the optical beacon (optical vehicle sensor) 4, the uplink areas UA1, UA2, and UA3 are upstream portions of the downlink areas DA1, DA2, and DA3 in the vehicle traveling direction (FIG. 3). And the upstream ends c1, c2, c3 of the downlink areas DA1, DA2, DA3 and the uplink areas UA1, UA2, UA3 coincide with each other. Therefore, the vehicle traveling direction lengths of the downlink areas DA1, DA2, and DA3 are equal to the entire lengths of the communication areas A1, A2, and A3 in the same direction.

In the illustrated form, the downstream side of the first communication area A1 and the upstream side of the second communication area A2 do not overlap, and the downstream side of the second communication area A2 and the upstream side of the third communication area A3 Is a configuration that does not overlap, but a part of each communication area may be overlapped (not shown).
As described above, each of the projector / receiver units 9 of each optical beacon 4 has a plurality (three in the illustrated example) of the projector / receivers 8a, 8b, 8c, and these projectors / receivers 8a, 8b, 8c. Are a plurality of different ranges (three in the example) in the vehicle traveling direction of the road R, each set as a communication area. Then, at least one projector / receiver 8 that communicates with the vehicle-mounted device 2 is selected by the selection unit 25 of the beacon controller 7 described later. Thereby, it is possible to communicate with the in-vehicle device 2 in all of the three communication areas A1, A2, and A3, and to communicate with the in-vehicle device 2 in one or two of the three communication areas.

[Configuration of in-vehicle device and vehicle]
FIG. 5 is a schematic configuration diagram of the in-vehicle device 2 that communicates with the optical beacon 4 and the vehicle C in which the in-vehicle device 2 is mounted.
As shown in FIG. 5, the vehicle C includes a vehicle body 15 having a driver's boarding seat (not shown), the vehicle-mounted device 2 mounted on the vehicle body 15, and electronic control for integrally controlling each part of the vehicle C. A device (ECU) 16, an engine 17 that drives the vehicle body 15, a brake device 18 that brakes the vehicle body 15, and a speed detector 26 that constantly detects the current speed of the vehicle C are provided. The ECU 16 performs various controls on the vehicle C such as drive control of the engine 17 based on the accelerator operation of the driver and braking control based on the brake operation.

The in-vehicle device 2 includes an in-vehicle computer 19, a projector / receiver (in-vehicle head) 20 connected to the sensor interface of the computer 19, and a display 21 and a speaker device 22 as a human interface for the driver of the passenger seat. Yes.
The light emitter / receiver 20 of the in-vehicle device 2 also includes a light emitting diode (LED) and a photosensor (not shown), similar to the light receiver / receiver 8 of the optical beacon. Among these, the LED emits uplink information (uplink light) made of near infrared rays, and the photo sensor receives downlink information (downlink light) made of near infrared rays emitted in the communication area of the optical beacon 4. To do.

  The in-vehicle computer 19 includes a programmable microcomputer having a CPU, a memory (RAM), and a storage device (ROM), and performs control processing of road-to-vehicle communication with the optical beacon 4 by the light projector / receiver 20. The in-vehicle computer 19 stores a program for executing each predetermined function in a storage device, and includes a support control unit 24 as a function unit to be executed by this program. As will be described later, the support control unit 24 controls safe driving support for the driver based on the support information included in the downlink information received by the in-vehicle device 2.

  Further, the projector / receiver 20 of the in-vehicle device 2 is provided so as to be directed in a direction in which it can communicate with each of the three projectors / receivers 8 a, 8 b, 8 c of the optical beacon 4. For example, the in-vehicle device 2 includes three projectors / receivers 20, one of which is provided at the front of the vehicle body 15 such as on the dashboard on the near side of the windshield of the vehicle body 15, and the other is the vehicle body 15. The other one is provided at the rear part of the vehicle body 15 such as the front side of the rear glass of the vehicle body 15. Alternatively, one projector / receiver 20 may be installed on the roof of the vehicle body 15, thereby communicating with each of the three projectors / receivers 8 a, 8 b, 8 c of the optical beacon 4.

[Road-to-vehicle communication]
FIG. 6 shows a two-way road-to-vehicle communication procedure performed between at least one of the light projecting / receiving devices 8a, 8b, 8c of the optical beacon 4 and the light projecting / receiving device 20 of the in-vehicle device 2 in the communication area. . Hereinafter, the contents of this road-to-vehicle communication will be described with reference to FIG. The procedure of road-to-vehicle communication performed in each of the communication areas A1, A2, and A3 is the same. Below, the road-vehicle communication performed in 1st communication area | region A1 is demonstrated as a representative.
First, the beacon controller 7 of the optical beacon 4 sends the lane notification information as the first information before switching the downlink from the first projector / receiver 8a of each projector / receiver unit 9 corresponding to each lane R1 to R4. The first downlink information 28 is continuously transmitted to the downlink area DA1 of each lane R1 to R4 at a predetermined transmission cycle (F1 in FIG. 6). 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 DA1, the light emitter / receiver 20 of the vehicle-mounted device 2 receives the first downlink information 28 including the lane notification information (no vehicle ID). . At this time, the in-vehicle computer 19 of the in-vehicle device 2 recognizes that the vehicle C exists in the first communication area A1. Thereafter, the in-vehicle computer 19 starts transmission of the uplink information 29 (F2 in FIG. 6), and transmits this uplink information 29 to the first projector / receiver 8a of the optical beacon 4 at a predetermined transmission cycle (FIG. 6). 6 F3).

The in-vehicle computer 19 transmits the uplink information 29 in the uplink area UA1 (see FIG. 3), stores the specific vehicle ID in the vehicle C in the uplink information 29, and transmits the uplink information 29. .
In addition, when the vehicle-mounted computer 19 has the travel time information between beacons, this information is also included in the uplink information 29. The in-vehicle computer 19 continues to transmit the uplink information 29 until it recognizes that the beacon controller 7 of the optical beacon 4 has switched the downlink.

On the other hand, when the first projector / receiver 8a of the optical beacon 4 receives the uplink information 29 (F4 in FIG. 6), the beacon controller 7 has the vehicle ID information as the second information after the downlink switching. The transmission of the second downlink information 30 including the lane notification information for the in-vehicle device 2 is started (F5 in FIG. 6), and the transmission of the downlink information 30 is repeated as much as possible within a predetermined time (FIG. 6). F6).
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 vehicle-mounted computer 19 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 30 includes, in addition to the lane notification information including the vehicle ID, traffic jam information, section travel time information, event regulation information, the support information for safe driving support for the driver, and the like. ing.
This support information includes the traffic signal information, which is timing information that changes the color of the traffic light downstream of the optical beacon 4, and a predetermined position downstream of the optical beacon 4 from the downlink area DA1 (for example, before the front intersection). Distance information that is length information to a certain stop line) is included.

  As shown in FIG. 6, the second downlink information 30 includes a single or a plurality of minimum frames 31. According to the “near infrared interface standard”, the data amount of the minimum frame 31 is defined as a total of 128 bytes, and 5 bytes are allocated to the header portion 32 and 123 bytes are allocated to the actual data portion 33.

According to the standard, the second downlink information 30 can be composed of 1 to 80 minimum frames 31, and the transmittable time is set to 250 ms. The downlink information 30 is composed of an arbitrary number of minimum frames 31 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 31 is about 1 ms. Therefore, for example, when one downlink information 30 is composed of the three minimum frames 31, the transmission period of the downlink information 30 is about 3 ms. Therefore, the downlink information 30 has a predetermined transmittable time (250 m). ) Will be repeatedly transmitted about 80 times during this period.

The in-vehicle computer 19 of the in-vehicle device 2 recognizes the downlink switching in the optical beacon 4 at the time when the second downlink information 30 is received (F7 in FIG. 6), and at this time, transmits the uplink information 29. Stop.
Thus, the in-vehicle computer 19 of the in-vehicle device 2 receives the downlink information 30 including the support information, and starts safe driving support control based on the support information, for example (F8 in FIG. 6).

[Processing contents of beacon controller]
The selection unit 25 (see FIG. 2) of the beacon controller 7 includes at least one projector / receiver that communicates with the vehicle-mounted device 2 among the three projectors / receivers 8a, 8b, and 8c in one projector / receiver unit 9. Process to select one. The selection unit 25 automatically selects the light emitter / receiver 8 to communicate with the in-vehicle device 2 according to the place where the light emitter / receiver unit 9 is installed and the surrounding environment. Specifically, the selection unit 25 is less susceptible to the incidence of sunlight among the three communication areas A1, A2, and A3 (see FIG. 3) by the three projectors 8a, 8b, and 8c, respectively. Select at least one.

A selection method by the selection unit 25 will be described.
In FIG. 2, first, the selection unit 25 determines the number of occurrences of reception errors in a predetermined time in the uplink information received by the first light emitter / receiver 8a, the second light emitter / receiver 8b, and the third light emitter / receiver 8c. It is detected, and a predetermined threshold value set in advance is compared with each measured value. If any measured value is equal to or smaller than the threshold value, it is determined that it is daytime and is affected by sunlight. This is because there is no influence of sunlight at night, so all measured values are equal to or greater than the threshold value. Note that the received light level may be used instead of the number of occurrences of the reception error.
And if the selection part 25 discriminate | determines that it has received the influence of sunlight, the selection part 25 will select a light projector / receiver with the following selection methods.
If it is determined that there is no influence of sunlight at night, a good communication environment is ensured in all of the first light emitter / receiver 8a, the second light emitter / receiver 8b, and the third light emitter / receiver 8c. The selection unit 25 automatically selects at least one preset projector / receiver 8.

As a first selection method, the selection unit 25 detects the number of occurrences of reception errors in each predetermined time of the first light projecting / receiving device 8a, the second light projecting / receiving device 8b, and the third light projecting / receiving device 8c. The projector / receiver 8 having a small number of occurrences is selected. Thereby, the incident direction of sunlight can be discriminated. Then, communication with the in-vehicle device 2 is performed using the selected projector / receiver 8.
As a second selection method, the selection unit 25 detects the number of occurrences of reception errors in each predetermined time of the first projector / receiver 8a, the second projector / receiver 8b, and the third projector / receiver 8c, and presets them. A predetermined threshold value and each measured value are compared, and the projector / receiver 8 that has a measured value higher than the threshold value is selected. Then, communication with the in-vehicle device 2 is performed using the selected projector / receiver 8. In this case, two or three projectors / receivers 8 may be selected.

  In each of the above selection methods, the selection unit 25 detects the number of occurrences of reception errors, thereby selecting the projector / receiver 8 to be used on the optical beacon 4 side and determining the communication area. Instead of the number of occurrences, the light reception level in the light projector / receiver may be detected. That is, in a state where road-to-vehicle communication is not performed, the selection unit 25 detects the light reception levels of the first light projecting / receiving device 8a, the second light projecting / receiving device 8b, and the third light projecting / receiving device 8c, A low light emitter / receiver may be selected, or a predetermined threshold value set in advance and a measured value of each light reception level may be compared to select a light emitter / receiver having a measured value lower than the threshold value. This is because “the light receiving level is high” in the projector / receiver in a state in which road-to-vehicle communication is not performed is because more noise light such as sunlight is received.

Furthermore, together with each of the selection methods, the selection unit 25 is based on which of the reception of uplink information from the in-vehicle device 2 and the transmission of downlink information from the optical beacon 4 side should be prioritized. It is preferable to select a communication area. For example, in FIG. 3, in the case of a lane in which the vehicle C is traveling northward, sunlight from the south side is easily reflected on the road surface and is incident on the first light emitter / receiver 8a. When the uplink information from 2 is received using the first projector / receiver 8a, a reception error is more likely to occur than when the information is received by the third projector / receiver 8c.
However, in this case, since the sunlight from the south side and the near-infrared direction from the LED of the third projector / receiver 8c are likely to be in the same direction, the projector / receiver 20 of the vehicle-mounted device 2 is down from the optical beacon 4. When the link information is received using the third projector / receiver 8c, a reception error is more likely to occur than when the link information is received by the first projector / receiver 8a.

Therefore, in the bidirectional communication between the optical beacon 4 and the vehicle-mounted device 2, the uplink information received by the optical beacon 4 is more important, and when it is necessary to prioritize the reception of the uplink information, the selection unit 25 selects the third projector / receiver 8c that is unlikely to cause a reception error with respect to the uplink information. Conversely, when the downlink information received by the in-vehicle device 2 is more important and it is necessary to prioritize the reception level of the downlink information, the selection unit 25 is less likely to generate a reception error for the downlink information. The light emitter / receiver 8a is selected.
Alternatively, the selection unit 25 selects the third projector / receiver 8c so that the optical beacon 4 receives the uplink information, and selects the first projector / receiver 8a so that the in-vehicle device 2 receives the downlink information. You may make it do.

  In this way, the selection unit 25 automatically selects the projector / receiver 8 so as to use the downlink region or the uplink region set in a range that is not easily affected by the incidence of sunlight for communication. As a result, communication errors caused by the incidence of sunlight can be reduced.

  As described above, according to the embodiment, a plurality of optical beacons 4 are installed at various locations on the road (see FIG. 1). The road-to-vehicle communication system includes an optical beacon that is different from other optical beacons with respect to a relative position with respect to the communication area by the light projector / receiver 8. That is, since the plurality of optical beacons 4 can include optical beacons that are different from other optical beacons with respect to the mounting direction of the projector / receiver 8 at the installation position of the projector / receiver 8 of the optical beacon 4, Depending on the location and environment where each optical beacon 4 is installed, the mounting direction of the light emitter / receiver 8 of the optical beacon 4 may be set differently from that of other optical beacons and less likely to be affected by the incidence of sunlight. it can. As a result, a communication area (uplink area) is set in the plurality of optical beacons 4 at positions where it is difficult to prevent the reception of the uplink light from the in-vehicle device 2 due to the influence of sunlight (such as reflection). A road-to-vehicle communication system including an optical beacon 4 having a light projector / receiver 8 is configured.

Specifically, the plurality of optical beacons 4 includes an optical beacon that communicates using the first light projector / receiver 8a, an optical beacon that communicates using the second light projector / receiver 8b, and the first It consists of at least two types of optical beacons out of optical beacons that communicate using the triple throw light receiver 8c.
In FIG. 1, in the first optical beacon 4a and the fifth optical beacon 4e, the first light emitter / receiver 8a is used, and the upstream side in the vehicle traveling direction is set as the communication area A1. In the second optical beacon 4b, the third light projector / receiver 8c is used, and the downstream side in the vehicle traveling direction is set as the communication area A3. Moreover, in the 3rd optical beacon 4c, the 2nd light projector / receiver 8b is utilized, and the range including the part directly under the installation position of this 2nd light projector / receiver 8b is set as communication area A2. In the fourth optical beacon 4d, the first light projecting / receiving device 8a and the second light projecting / receiving device 8b are used, and the upstream range in the vehicle traveling direction (communication area A1) and the portion immediately below the installation position of the light projecting / receiving device 8b are used. Both of the included ranges (communication area A2) are set as the communication area A4. This setting may be performed in advance when installing each optical beacon 4 at various locations on the road, or automatically by the function of the selection unit 25 after each optical beacon 4 is installed. It may be performed manually.

  When the optical beacon 4 is installed in various places on the road, the case where the communication area is set in advance will be specifically described. When the second optical beacon 4b is installed, the second optical beacon 4b is set. In the projector / receiver 8c, the range on the downstream side in the vehicle traveling direction from the installation position of the projector / receiver 8c is preset as the communication area A3. And the vehicle equipment 2 has the light projector / receiver 20 orient | assigned to the direction which can communicate between the light projector / receiver 8c of this optical beacon 4b.

The case where the communication area is automatically set in each optical beacon 4 by the function of the selection unit 25 will be further described. Each of the optical beacons 4 includes a light projecting / receiving unit 9 having a plurality of light projecting / receiving units 8a, 8b, 8c, and each of these light projecting / receiving units 8a, 8b, 8c is in the vehicle traveling direction on the road R. A plurality of different ranges are set as communication areas. And the selection part 25 of the beacon controller 7 selects a plurality of communication areas that are not easily affected by the incidence of sunlight according to the place where each optical beacon 4 is installed, the installed environment, and the time zone. At least one projector / receiver 8 to be communicated with the vehicle-mounted device 2 is selected from the projectors / receivers 8a, 8b, 8c.
For example, according to the selection method, the selection unit 25 sets the communication area in each optical beacon 4 as a range on the upstream side in the traveling direction of the vehicle, a range including a portion directly below the installation position of the projector / receiver unit 9, It can be a range on the downstream side of the traveling direction, or can be selected and switched.

Thereby, in each optical beacon 4 installed in each place, the communication error which arises by incidence of sunlight can be reduced. In particular, in the evening time zone, the sunlight reflected on the road surface is likely to enter the light projecting / receiving device 8 of the optical beacon 4, but the selecting unit 25 selects the light projecting / receiving device 8 used for communication with the in-vehicle device 2. By selecting, a communication error due to the influence of sunlight can be reduced.
In addition, communication errors can be reduced in this way, and when one projector / receiver unit 9 simultaneously uses a plurality of the three projectors / receivers 8a, 8b, 8c, one projector / receiver is used. The range of the communication area can be widened compared to the case where only the data is used, and a large amount of data can be transmitted and received.

  In addition, since communication errors caused by the incidence of sunlight can be reduced in this way, the optical beacon 4 can accurately receive uplink information from the in-vehicle device 2, and the in-vehicle device 2 can receive the optical beacon. 4 can correctly receive downlink information. For this reason, the optical beacon 4 side (traffic control system 1 side) can accurately obtain predetermined information from the in-vehicle device 2, and the in-vehicle device 2 side receives a predetermined service from the optical beacon 4 side. be able to. Thereby, the support control part 24 of the said vehicle-mounted computer 19 can perform appropriately the control of the safe driving assistance with respect to a driver based on the support information contained in the downlink information which the vehicle-mounted apparatus 2 received.

  As described above, according to the present invention, it is possible to improve the quality of road-to-vehicle communication between the optical beacon 4 and the vehicle-mounted device 2. Even in a place where the quality of the vehicle-to-vehicle communication is deteriorated and the in-vehicle device 2 cannot receive a useful service, this service can be provided by adopting the road-to-vehicle communication system.

  The safe driving support includes, for example, deceleration control of the vehicle C and notification control to the driver based on support information such as traffic signal information and distance information. This traffic signal information is timing information or the like at which the lamp color of the traffic light on the downstream side of the optical beacon 4 changes, and the distance information is a predetermined position on the downstream side of the optical beacon 4 from the communication area (for example, in front of the vehicle traveling direction). This is the length information up to the stop line provided before the intersection.

  In addition, the operation of a system that supports safe driving is greatly affected by the quality of road-to-vehicle communication. This is because if the quality of road-to-vehicle communication deteriorates, the information required by the in-vehicle device 2 cannot be received from the infrastructure without a shortage. For example, it is impossible to determine whether or not the vehicle C should stop near the stop line before the intersection because it cannot receive all or part of the information related to the timing of changing the light color of the traffic light, and it relates to the distance to the stop line. Since all or part of the information cannot be received, it may be impossible to determine the braking method of the brake control performed to stop before the stop line (the braking method may be wrong).

Therefore, according to the present invention, for example, in one optical beacon 4, the signal information, distance information, and the like are transmitted in each of the first communication area A1 and the third communication area A3. Even if there is a shortage of information received in the first communication area A1, if the information can be received in the third communication area A3 without a shortage, it is possible to implement safe driving support control, which is very useful.
Thus, the certainty of the information transmission from the optical beacon 4 to the vehicle equipment 2 can be further improved by having a plurality of communication areas. For this reason, it is extremely useful in a safe driving support system that greatly depends on the quality of road-to-vehicle communication.

In addition, when transmitting the said traffic signal information, distance information, etc. in each of the first communication area A1 and the third communication area A3 as described above, for example, the distance information transmitted in the first communication area A1 includes The distance from one communication area A1 to the stop line may be included, and the distance information transmitted in the third communication area A3 may include the distance from the third communication area A3 to the stop line. According to this, compared with the case where the same information is transmitted uniformly, the accuracy of information can be further improved. For example, information about VICS (registered trademark) can be transmitted to the first communication area A1, and information about safe driving support can be transmitted to the third communication area A3. By transmitting information according to the application to different communication areas in this way, the amount of information transmitted in road-to-vehicle communication can be increased, which is very useful.

  As described above, since the traffic signal information and the distance information are included in the downlink information, the support control unit 24 of the in-vehicle computer 19 has entered the intersection at the time when the traffic signal ahead changes to red. In order to prevent this, the ECU 16 operates the brake device 18 to decelerate the vehicle C and notifies the driver that the traffic light turns red by the display 21 and the speaker device 22.

The present invention is not limited to the above embodiment.
For example, the plurality of optical beacons 4 installed in various places on the road are composed of at least two types of optical beacons 4 having different relative positions between the installation position of the light projecting / receiving device 8 and the communication area of the light projecting / receiving device 8. Well, in the said embodiment, although it is the structure which consists of three types of optical beacons 4 of 1st communication area | region A1, 2nd communication area | region A2, and 3rd communication area | region A3, it consists of 2 types of optical beacons 4 of these. It may be a configuration. And the vehicle equipment 2 should just be equipped with the light projector / receiver 20 orient | assigned to the direction which can communicate between these at least 2 types of said optical beacons 4. FIG. Thereby, the vehicle equipment 2 can communicate with each of at least two types of optical beacons 4 having different communication areas.

  Furthermore, in the above embodiment, one projector / receiver unit 9 of each optical beacon 4 has three projectors / receivers 8a, 8b, 8c. However, these projectors / receivers 8 have at least two. It is sufficient that the projector / receiver 8 is selected and used by the function of the selection unit 15.

It is a block diagram which shows the whole structure of the road-vehicle communication system containing the vehicle equipment of this invention. It is a schematic block diagram with an optical beacon and vehicle equipment. It is a side view which shows an optical beacon and its communication area. It is a top view of an optical beacon. It is a schematic block diagram of the vehicle equipment which communicates with an optical beacon, and the vehicle by which this vehicle equipment is mounted. It is a conceptual diagram which shows the procedure and data content of the road-vehicle communication performed in a communication area. It is explanatory drawing explaining the conventional road-vehicle communication system.

Explanation of symbols

2 Onboard equipment 4 Optical beacon 8 Emitter / receiver (beacon side)
8a First light emitter / receiver 8b Second light emitter / receiver 8c Third light emitter / receiver 15 Car body 16 Electronic control unit (ECU)
19 On-vehicle computer 20 Emitter / receiver (on-vehicle device side)
25 Selection part A1, A2, A3, A4, A5 Communication area C Vehicle R Road

Claims (6)

An in-vehicle device of a vehicle traveling on a road, and a plurality of optical beacons each having a light emitter / receiver having a communication area set in a predetermined range of the road, between the in-vehicle device and the optical beacon A road-vehicle communication system that performs two-way communication using optical signals,
The plurality of optical beacons includes an optical beacon having a first light emitter / receiver in which a range upstream in the vehicle traveling direction from the installation position is set as a first communication area, and a second range including a portion immediately below the installation position. An optical beacon having a second light emitter / receiver set as a communication area, and an optical beacon having a third light emitter / receiver in which a range downstream of the installation direction from the installation position is set as a third communication area Consisting of at least two types of optical beacons,
The at least two types of optical beacons include an optical beacon having the light emitter / receiver in which the communication area is set at a position where it is difficult to prevent the reception of uplink light due to the reflection of sunlight or the like. A road-vehicle communication system characterized by the above.   The road-to-vehicle communication system according to claim 1, wherein the in-vehicle device includes a light projector / receiver directed in a direction in which communication can be performed between at least two types of the optical beacons.   Each of the optical beacons communicates with the in-vehicle device from a plurality of projectors / receivers in which a plurality of different ranges in the vehicle traveling direction on the road are set as communication areas, respectively. The road-to-vehicle communication system according to claim 1, further comprising: a selection unit that selects at least one projector / receiver. An optical beacon used for road-to-vehicle communication, which performs bidirectional communication with an in-vehicle device of a vehicle using an optical signal,
A first projector / receiver in which a range upstream of the installation position in the vehicle traveling direction is set as a first communication region, a second projector / receiver in which a range including a portion directly below the installation position is set as a second communication region, And, at least two of the third projector and receiver, the range of the downstream side of the vehicle traveling direction from the installation position is set as the third communication region, and
An optical beacon comprising: a selection unit that selects at least one light projecting / receiving device to be communicated with the vehicle-mounted device from the at least two light projecting / receiving devices. An in-vehicle device for a vehicle traveling on a road, and a plurality of ranges different from each other with respect to the vehicle traveling direction of the road, including a range upstream of the optical beacon installation position and a portion immediately below the optical beacon installation position. For road-to-vehicle communication, the range downstream from the installation position in the vehicle traveling direction performs two-way communication using optical signals with an optical beacon having a plurality of light emitters / receivers set as a communication area. An in-vehicle device to be used,
A plurality of vehicle-side projectors / receivers that can communicate with each of the plurality of light-beacon-side projectors / receivers,
The plurality of on-vehicle side light emitters / receivers have at least one of the plurality of light beacon side light emitters / receivers set as a communication area that is not easily affected by the incidence of sunlight. An in-vehicle device characterized by including a light projecting / receiving device oriented in a direction in which communication with the light projecting / receiving device can be performed . A vehicle comprising: a vehicle body; a control device that controls driving and braking of the vehicle body; and the in-vehicle device according to claim 5 mounted on the vehicle body.

Images