JP2010002260A - Position determination system and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To determine abnormality in the position of an own vehicle that an onboard device of a vehicle has autonomously at a road side. <P>SOLUTION: A position determination system determines abnormality in the position of an own vehicle that the onboard device 2 of a vehicle 5 corresponding to both of optical wireless communication and radio wave wireless communication has autonomously at a road side. In the system, a passage position X0 of the vehicle 5 to a communication area A of a beacon head 8 is identified at a road side, based on uplink light UO transmitted to the beacon head 8 by the onboard device 2, and utilizes the identified passage position X0 of the vehicle 5 to determine, at a road side, whether an own vehicle position X1 of the vehicle 5 included in a radio wave signal S5 transmitted by the onboard device 2 after optical wireless communication with the beacon head 8 is abnormal. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a position determination in which it is determined on the road side whether or not the vehicle position autonomously possessed by the in-vehicle device is abnormal by using optical wireless communication between the optical beacon and the in-vehicle device mounted on the vehicle. The present invention relates to a system and method.

As a traffic information service using a road-to-vehicle communication system, so-called VICS (Vehicle Information and Communication System: registered trademark of Road Traffic Information Communication System Center) using optical beacons, radio beacons or FM multiplex broadcasting has already been developed. ing. Among these, the optical beacon employs optical wireless communication using near infrared 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 in-vehicle device (see, for example, Patent Document 1).

The optical beacon includes a light emitting / receiving device (beacon head) in which a communication area for optical wireless communication is set to a predetermined range of a road, and the beacon head emits a downlink light (LED). And a photodiode (PD) that receives uplink light from the in-vehicle device.
On the other hand, the in-vehicle device is also provided with a light projecting / receiving device (in-vehicle head) having a light emitting diode and a photodiode in order to perform bidirectional optical wireless communication with the beacon head.

The present applicant uses the road-to-vehicle communication system using the above-described optical beacon to set the reference position of the uplink region set on the road (for example, the upstream end in the vehicle traveling direction) of the vehicle passing through the communication region. We have already proposed a technology that makes it possible to grasp accurate distance information on the vehicle side by including the distance information starting from the reference position as the starting position and including the distance information in the downlink information after downlink switching. (For example, refer to Patent Documents 2 and 3).
In this case, for example, if the distance information from the reference position to a predetermined position on the downstream side (for example, a stop line provided in front of the traffic light) is included in the downlink information, the in-vehicle device that has received this distance information Safe driving support can be provided by forcibly braking the vehicle before the stop line or by notifying the driver to stop or decelerate.

  According to the optical beacon interface standard, the total length of the uplink region in the vehicle traveling direction is defined as 1.6 m. Therefore, if the communication area of the beacon head is set according to this standard, the vehicle passage position relative to the communication area can be specified by regarding the light reception time of the uplink light and the passage time of the reference position as almost the same. In this case, the error of the passing position that can be measured on the beacon side is about 1.6 m at the maximum.

On the other hand, in-vehicle devices compatible with VICS often support not only optical wireless communication with an optical beacon but also radio wave wireless communication.
In this case, by exchanging information on the position of the host vehicle with other vehicles through inter-vehicle communication, a cooperative system can be configured to help prevent head-on collisions at intersections and collisions when turning left or right (see Patent Document 4). By notifying the traffic information center of the vehicle position by inter-road communication to the radio wave radio communication device, it can be used to improve the accuracy of the traffic information grasped by the center.

JP 2005-268925 A JP 2007-293660 A JP 2007-317166 A JP 2002-183889 A

By the way, in a VICS-compatible in-vehicle device, usually, the position of the vehicle is autonomously captured by positioning data received by a GPS (Global Positioning System) receiver. However, the GPS positioning data may include an error of about 10 m depending on the environment, and this error is less reliable than the error of the passing position obtained by the uplink light to the optical beacon.
Therefore, if GPS positioning data is directly adopted as the own vehicle position and transmitted to the outside during inter-vehicle communication or inter-road communication, the cooperative system with other vehicles or the infrastructure may be out of order.

Therefore, it is recommended that the more accurate passing position that can be specified by receiving the uplink light is included in the downlink information and notified to the in-vehicle device, and the vehicle position by GPS is corrected in the in-vehicle device based on this passing position. The
However, even if such a correction function is provided in the in-vehicle device, if the reception of the downlink light from the beacon head fails, the positioning data by the GPS with a relatively large error is followed as it is, In addition, when the vehicle position management function in the in-vehicle device is defective, an accurate vehicle position cannot be obtained regardless of the correction.

  In view of such a situation, the present invention enables determination of an abnormality of the own vehicle position autonomously possessed by the in-vehicle device of the vehicle on the road side so that the presence of the vehicle with an abnormal own vehicle position can be determined. An object of the present invention is to provide a position determination system and method capable of warning a vehicle.

  A position determination system according to the present invention (Claim 1) is a position determination system for determining, on the road side, an abnormality in the position of a host vehicle autonomously possessed by a vehicle-mounted device that supports both optical wireless communication and radio wave wireless communication. A communication area for performing radio wireless communication with the in-vehicle device and a beacon head in which a communication area for performing optical wireless communication with the in-vehicle device is set to a predetermined range of a road; A roadside communication device capable of receiving an uplink signal including a radio signal including information related to the vehicle position of the vehicle, which is transmitted by the in-vehicle device after optical wireless communication with the beacon head, and the beacon. A position specifying unit for specifying a passing position of the vehicle with respect to the communication area based on uplink light received by a head; and the specified passing position and the uplink signal On the basis of the difference between the vehicle position, characterized in that the vehicle position is and a position determination unit determines abnormal or not.

According to the position determination system of the present invention, the position specifying unit specifies the passing position of the vehicle with respect to the communication area based on the uplink light received by the beacon head, and the position determining unit is Since it is determined whether or not the vehicle position is abnormal based on the difference from the vehicle position included in the uplink signal, it is determined on the road side that the vehicle on-vehicle device has an autonomous vehicle position abnormality. Can do.
For this reason, when it is determined that the vehicle position of a certain vehicle is abnormal, for example, the presence of a vehicle with poor vehicle position accuracy is notified by notifying the determination result to the in-vehicle device of each vehicle through a roadside communication device. Can be warned to the vehicle and other vehicles.

That is, in the position determination system of the present invention, when the position determination unit determines that the own vehicle position is abnormal, a downlink signal including a radio signal including the determination result is directed toward the communication area. It is preferable to further include a transmission control unit that causes the computer to transmit by broadcast (claim 2).
In this case, when the in-vehicle device of the vehicle to be determined receives the downlink signal including the determination result, for example, by notifying the passenger of the determination result by an in-vehicle display or the like, the position of the own vehicle It is possible to warn the passenger of a malfunction of the rating function.

  In addition, when an in-vehicle device of a vehicle other than the target vehicle receives a downlink signal including the determination result, the operation is changed to ignore the radio signal from the vehicle corresponding to the determination result. Thus, it is possible to prevent the inter-vehicle cooperation system from continuing based on the erroneous information on the own vehicle position.

By the way, in the position determination system according to the present invention, the determination process in the position determination unit includes a passing position specified by the uplink light and a vehicle position included in the uplink signal of the same transmission source as the uplink light. This can be done depending on whether the difference is within a predetermined range.
However, since there is a time lag between the uplink light reception time and the uplink signal reception time, the difference between the passing position and the vehicle position is simply compared without taking this time lag into consideration. However, it is not possible to perform accurate abnormality determination processing.

Therefore, the position determination unit compares the difference between the passing position and the own vehicle position with the travel distance traveled by the vehicle between the next first time and the second time. It is preferable to determine whether or not the position is abnormal (claim 3).
(A) First time when the beacon head receives the uplink light (b) Second time when the roadside communication device receives the uplink signal from the in-vehicle device of the same transmission source as the uplink light

In the position determination system of the present invention, when the beacon head has one light receiving element that receives uplink light from the in-vehicle device in an uplink area included in the communication area, the position specifying unit Can specify the reference position set in the uplink region as the passing position of the vehicle (claim 4).
However, the communication area of optical beacons that are actually used, especially the uplink area, is much wider than the official dimensions according to the interface standard in order to receive uplink light from the in-vehicle device more reliably. There is.

If the communication area is wide in this way, there is a high possibility that the difference between the reference position set in the communication area and the transmission position of the uplink light will be large. The accuracy of the passing position of the actual vehicle to be identified decreases.
Therefore, even if the uplink area is set widely in the vehicle traveling direction, the beacon head is included in the communication area in order to be able to accurately identify the passing position of the vehicle on the road side. A plurality of light receiving elements each having a light receiving area corresponding to each divided area obtained by dividing the area in the vehicle traveling direction, and the position specifying unit receives the uplink light among the plurality of light receiving elements. It is preferable that the reference position set in the divided region corresponding to the light receiving element is specified as the passing position of the vehicle.

An optical beacon equipped with a plurality of light receiving elements corresponding to such a divided region (hereinafter, sometimes referred to as a “PD split type” optical beacon) has been proposed by the present applicant (Japanese Patent Application). (See the specification of 2007-20910).
If this PD split type optical beacon is used, in order to improve the light reception opportunity of the uplink light, even if the uplink region is set to be long in the vehicle traveling direction, the individual components constituting the uplink region are configured. About a divided area, it becomes possible to set this narrowly in a vehicle advancing direction.

In addition, in the PD split type optical beacon, it is determined in which divided region the traveling vehicle (in-vehicle device) is uplinked by determining which of the plurality of photodiodes actually receives the uplink light. Whether the light is emitted can be specified on the road side.
Therefore, in this case, the traveling position of the vehicle (on-vehicle device) that emits the uplink light can be obtained with an accuracy that is less than or equal to the length in the vehicle traveling direction of each divided region, and the passing position evaluation accuracy can be improved. it can.

The position determination method of the present invention (Claim 6) is a determination method performed by the position determination system of the present invention (Claim 1), and has the same effects as the determination system.
Also in the position determination method of the present invention, when it is determined that the vehicle position is abnormal, a downlink signal composed of a radio signal including the determination result is broadcast to the roadside communication device toward the communication area. By transmitting, it is possible to warn the passenger of a malfunction of the position evaluation function of the own vehicle, and it is possible to prevent the cooperation system between the vehicles from continuing with other vehicles based on the incorrect own vehicle position information.

  As described above, according to the present invention, it is possible to determine on the road side the abnormality of the own vehicle position that the in-vehicle device of the vehicle has autonomously. By transmitting this determination result wirelessly to the in-vehicle device of each vehicle, the own vehicle position Can warn the vehicle and other vehicles of the presence of an abnormal vehicle.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[First Embodiment]
[Overall system configuration]
FIG. 1 shows the overall configuration of a traffic signal control system exemplified as an example of the position determination system of the present invention.
As shown in FIG. 1, the traffic signal control system of this embodiment includes a traffic signal 1, an in-vehicle device 2 (see FIG. 2), a vehicle detector 3, a central device 4, a beacon head 8 of an optical beacon 11, and an in-vehicle device. The vehicle 5 etc. which mount the apparatus 2 are included.

Each traffic signal 1 is installed at each of a plurality of intersections Ci (i = 1 to 12), and is connected to a router 7 via a communication line 6 such as a telephone line. This router 7 is connected to a central device 4 in a traffic control center, and the central device 4 constitutes a local area network (LAN) with each traffic signal 1 at an intersection Ci in a predetermined area.
Therefore, the central device 4 can bidirectionally communicate with each traffic signal 1, and each traffic signal 1 can also communicate bidirectionally with other traffic signals 1. The central device 4 may be installed on the road instead of the traffic control center.

In order to count the number of vehicles flowing into each intersection Ci, the vehicle detector 3 is installed on the upstream side of each corresponding intersection Ci and is connected to each corresponding traffic signal 1 via a dedicated communication line. Yes. The optical beacon 11 is installed at various locations on the road to exchange predetermined information with the in-vehicle device 2 through optical wireless communication, and the beacon head 8 of the optical beacon 11 is also connected to each traffic via a dedicated communication line. Connected to traffic light 1.
In FIG. 1, for simplification of illustration, only one signal lamp 1b is depicted at each intersection Ci, but each actual intersection Ci intersects each other as shown in FIG. 2, for example. Four signal lamps 1b are installed for going up and down the road.

[Central equipment]
FIG. 3 is a block diagram showing the configuration of the central device 4.
As illustrated in FIG. 3, the central device 4 includes a control unit 401, a display unit 402, a communication unit 403, a storage unit 404, and an operation unit 405.
The control unit 401 of the central device 4 includes a workstation (WS), a personal computer (PC), and the like, and is connected to each hardware unit via an internal bus, and controls the operation of each unit.

The control unit 401 of the central device 4 collects, processes (calculates) and records various traffic data from the vehicle detector 3 and the beacon head 8 connected to the traffic signal 1, and signals based on the data. Provides control and provision of traffic information.
For example, the control unit 401 controls the traffic signal 1 at the intersection Ci belonging to its own network with system control for adjusting a group of traffic signals on the same road, or wide area control (surface) that extends this system control to the road network. Control).

The display unit 402 of the central device 4 includes a road map of an area managed by the central device 4 and a display screen on which positions of all traffic signals 1, vehicle detectors 3, beacon heads 8 and the like are displayed on the road map. It notifies the central operator of traffic conditions such as traffic jams and accidents.
The communication unit 403 of the central device 4 is a communication interface connected to the LAN side via the communication line 6, and includes a signal control command S1 related to the timing of switching the color of the signal lamp 1b every predetermined time, traffic information, and the like. The traffic information S2 is transmitted to each traffic signal 1 (see FIGS. 1 and 2).

The signal control command S1 is transmitted every signal control parameter calculation cycle (for example, 1.0 to 2.5 minutes), and the traffic information S2 is transmitted every five minutes, for example.
Further, the communication unit 403 of the central device 4 transmits the beacon information S3 regarding the travel time of the vehicle 5 obtained from the beacon head 8 from each traffic signal 1 and the detection signal S4 of the vehicle detector 3 in almost real time (for example, , 0.1 to 1.0 second period) (see FIGS. 1 and 2).

The storage unit 404 of the central device 4 includes a hard disk, a semiconductor memory, and the like, and stores a traffic control program for performing the system control and wide area control, a traffic index calculation program used for the control, and the like. . The storage unit 404 temporarily stores the signal control command S1 and the traffic information S2 generated by the control unit 401, the beacon information S3 and the sensing signal S4 acquired from the LAN side, and the like.
The operation unit 405 of the central device 4 includes an input interface such as a keyboard and a mouse. The operation unit 405 allows the central operator to perform a display switching operation on the display unit 402.

[Traffic signal]
FIG. 2 is a road plan view showing an outline of the traffic signal 1.
FIG. 2 illustrates an intersection C where the main roads RM1 and RM2 having a relatively large traffic volume and the slave roads RS1 and RS2 having a relatively small traffic volume merge.
The traffic signal 1 includes four signal lamps 1b installed on the main roads RM1 and RM2 and secondary roads RS1 and RS2, and a traffic signal controller 1a connected to the signal lamp 1b via a communication line 9. It has.

As shown in FIG. 2, the traffic signal controller 1a of the present embodiment includes roadside communication capable of radio wave wireless communication with the vehicle detector 3, the beacon head 8, and the in-vehicle device 2 in addition to the signal lamps 1b. The machine 10 is connected via the communication line 9.
The traffic signal controller 1a receives the signal control command S1 from the central device 4, and based on the signal control command S1, turns on / off each signal light such as blue, yellow, red and right turn arrow of each signal lamp 1b. Control blinking.

Further, the traffic signal controller 1a includes the traffic information S2 received from the central device 4 and the intersection ID stored in the traffic information controller 1a in the downlink information transmitted by the beacon head 8, and transmits it to the in-vehicle device 2 by optical wireless communication. can do.
Furthermore, the traffic signal controller 1a can acquire the beacon information (uplink information) S3 received by the beacon head 8 from the in-vehicle device 2 from the beacon head 8, and can acquire the sensing signal S4 from the vehicle detector 5. .

FIG. 4 is a block diagram showing the configuration of the traffic signal controller 1a.
As shown in FIG. 4, the traffic signal controller 1 a includes a control unit 101, a lamp driving unit 102, a communication unit 103, and a storage unit 104.
The control unit 101 of the traffic signal controller 1a is composed of one or a plurality of microcomputers. The control unit 101 is connected to the lamp driving unit 102, the communication unit 103, and the storage unit 104 via an internal bus, and the control unit 101 controls operations of these hardware units.

The control unit 101 of the traffic signal controller 1a drives each signal lamp 1b in accordance with a signal control command S1 that is an output as a result of the central device 4 performing the system control and the wide area control, and performs a predetermined operation based on the command S1. The signal lamp color of each signal lamp 1b is switched at the timing.
The lamp drive unit 102 includes a semiconductor relay (not shown), and corresponds to each of the blue, yellow, and red lamps of the plurality of signal lamps 1b based on the signal output command S1 input from the control unit 101. Then, the AC voltage (AC 100 V) or DC voltage supplied to the signal lights of each color is turned on / off.

The communication unit 103 of the traffic signal controller 1a is connected to the central device 4, the vehicle detector 3, the beacon head 8, and the roadside communication device 10, and is a communication interface that performs bidirectional wired communication with them. .
The roadside communication device 10 is a transceiver that performs bidirectional radio communication with the in-vehicle device 2 of the vehicle 5 that flows into the intersection C, and is an uplink signal S5 that is a radio signal transmitted by the in-vehicle device 2. And a downlink signal S6 made up of a radio wave signal can be transmitted to the in-vehicle device 2 (see FIG. 2).

The uplink signal S5 includes at least a vehicle ID corresponding to the vehicle 5 on which the in-vehicle device 2 is mounted, and the vehicle position autonomously possessed by the vehicle 5, for example, a latitude, longitude, and altitude. Contains information about. When a position determination unit 101B described later determines that the host vehicle position X1 is abnormal, at least information related to the determination result is included in the downlink signal S6.
As in the case of optical wireless communication with the beacon head 8, the travel time information of the in-vehicle device 2 may be transmitted to the roadside communication device 10 with the uplink signal S5, and traffic jam information, event regulation information, etc. You may transmit to each vehicle-mounted apparatus 2 by downlink signal S6.

The roadside communication device 10 of the present embodiment includes, for example, a medium / wide area communication device such as a wireless LAN or WiMAX (World Interoperability for Microwave Access), and transmits various information to and from the in-vehicle device 2 mounted on the vehicle 5. Bidirectional communication can be performed using the signals S5 and S6.
The roadside communication device 10 can communicate with the in-vehicle device 2 of the vehicle 5 traveling on each road RM1, RM2, RS1, RS2 flowing into the intersection C (see FIG. 2). The communication area of the roadside communication device 10 has a size capable of including the communication area A (see FIG. 7) of the beacon head 9 installed on each road RM1, RM2, RS1, RS2 inside, for example, in the road extension direction It is set to about 50 to 200 m.

However, the communication area of the roadside communication device 10 does not necessarily include the entire communication area A of the beacon head 8, and may be partially overlapped with the communication area A, or at least downstream of the communication area A. It is sufficient if the area is close enough to the vicinity of the side.
The storage unit 104 of the traffic signal controller 1a is composed of a hard disk, a semiconductor memory, and the like. As the temporary storage data, the signal control command S1, the traffic information S2, the beacon information S3, the sensing signal S5, the uplink signal S5, and the like. The downlink signal S6 and the like are stored.

Further, the storage unit 104 of the traffic signal controller 1a has communication for executing optical wireless communication between the beacon head 8 and the in-vehicle device 2 and radio wave communication between the in-vehicle device 2 and the roadside communication device 10. Computer programs for control are stored, and the control unit 101 reads out these computer programs from the storage unit 104 and executes communication control for the beacon head 8 and the roadside communication device 10.
The computer program can execute a determination process for determining an abnormality of the own vehicle position that the in-vehicle device 2 of the vehicle 5 autonomously has, and as its function definition, the position specifying unit 101A, the position determination unit 101B, , And a transmission control unit 101C (see FIG. 4). The processing contents by these units will be described later.

[In-vehicle device]
The in-vehicle device 2 mounted on each vehicle 5 is compatible with VICS, and has a bidirectional communication function by optical wireless communication with the beacon head 8 and a bidirectional communication function by radio wave wireless communication with the roadside communication device 10. And a navigation function for guiding to a destination point set by the passenger.
FIG. 5 is a block diagram showing the configuration of the in-vehicle device 2 (VICS compatible).
As shown in FIG. 5, the in-vehicle device 2 includes a GPS processing unit 201, a direction sensor 202, a vehicle speed acquisition unit 203, an in-vehicle communication unit 204, a storage unit 205, an operation unit 206, a display unit 207, an audio output unit 208, a process. Part 209, the vehicle-mounted head 210, and the like.

The GPS processing unit 201 receives a GPS signal from a GPS satellite, and based on the time information included in the GPS signal, the orbit of the GPS satellite, positioning correction information, etc., the vehicle position (latitude, longitude, and altitude) of the vehicle 5 Measure.
The direction sensor 202 is constituted by an optical fiber gyro or the like, and measures the direction and angular velocity of the vehicle 5. The vehicle speed acquisition unit 203 acquires the speed data of the vehicle 5 measured by a vehicle speed sensor (not shown) detecting the angular speed of the wheels.

The in-vehicle communication unit 204 is a wireless communication device using a radio signal as a communication medium, and can perform inter-vehicle communication with the in-vehicle device 2 of the other vehicle 5 using, for example, a CSMA (Carrier Sense Multiple Access) method.
The in-vehicle communication unit 204 prioritizes wireless communication with the roadside communication unit 10 in the communication area of the roadside communication unit 10 and performs time division multiplexing (TDMA) according to the time slot set by the roadside communication device 10. ) Car-to-road and road-to-vehicle communication using the method.

The storage unit 205 of the in-vehicle device 2 includes a hard disk, a semiconductor memory, and the like, and stores various data received by the in-vehicle communication unit 204 and the in-vehicle head 210 as temporary storage data.
In addition, the storage unit 205 of the in-vehicle device 2 includes a computer program for controlling communication with the roadside optical beacon 11 and the roadside wireless device 10 and a computer program for executing an optimum route search (car navigation) to the destination point. And road map data and the like necessary for the optimum route search are stored.

The road map data includes intersection data and link data.
The intersection data is data in which the intersection ID is associated with the position of the intersection. The link data includes the link ID of the specific link, the position of the start point / end point / interpolation point of the specific link, the link ID of the upstream link connected to the start point of the specific link, and the downstream link connected to the end point of the specific link. The link ID and the link cost of the specific link are associated with each other.

For example, there are as many link costs as there are combinations of the specific link and the downstream link connected to the end point. After entering the start point of the specific link, exit the end point of the specific link and enter the start point of the downstream link. The time required to do is set.
That is, the link cost includes the cost (time) required to travel from the start point to the end point of the specific link and the cost (time) required to travel from the end point of the link to the start point of the next downstream link, that is, Costs required to pass the intersection are included.

The operation unit 206 of the in-vehicle device 2 includes a touch panel, buttons, and the like, and a passenger of the vehicle 5 including a driver can set a destination.
The display unit 207 of the in-vehicle device 2 is composed of a monitor device (not shown) attached to the dashboard portion of the vehicle 5 and displays image data created by the processing unit 209 in the sensitive request process described later to the passenger. The audio output unit 208 outputs the audio data created by the processing unit 209 from a speaker (not shown).

The processing unit 209 of the in-vehicle device 2 includes one or a plurality of microcomputers and the like, and includes a GPS processing unit 201, a direction sensor 202, a vehicle speed acquisition unit 203, an in-vehicle communication unit 204, a storage unit 205, an operation unit 206, and a display. Each process of the unit 207 and the audio output unit 208 is controlled.
Further, the processing unit 209 of the in-vehicle device 2 displays the optimum route, which is the processing result of the optimum route search to the destination point, on the screen of the display unit 207, and displays the position of the vehicle 5 on the screen over the route display. Display above.

The matching process between the optimum route and the vehicle position of the vehicle 5 includes the vehicle position of the vehicle 5 measured by the GPS processing unit 201, the direction and angular velocity of the vehicle 5 measured by the direction sensor 202, and a vehicle speed acquisition unit. This is performed based on various data including the speed of the vehicle 5 acquired by the storage unit 203 and road map data stored in the storage unit 205.
Furthermore, the processing unit 209 of the in-vehicle device 2 is a vehicle for preventing a head-on collision at the intersection Ci (see FIG. 1) based on the vehicle position included in the received signal received from the other vehicle 5 in the in-vehicle communication unit 204. Inter-vehicle cooperative processing can be executed.

The in-vehicle head 210 of the in-vehicle device 2 is a projector / receiver for transmitting / receiving an optical signal composed of near-infrared light to / from the beacon head 8 in the communication area A of the optical beacon 11 described later. A light-emitting element such as a light-emitting diode (not shown) that transmits uplink light to be raised and a light-receiving element such as a photodiode (not shown) that receives downlink light from the beacon head 8 are provided inside. Yes.
The in-vehicle head 210 is installed on a dashboard in front of the windshield of the vehicle 5, for example.

[Configuration of optical beacon]
FIG. 6 is a plan view of an optical beacon 11 having the beacon head 8.
As shown in FIG. 6, the optical beacon 11 of the present embodiment includes a column 12 erected on the side of a road R having a plurality of lanes R1 to R4 (four in the example of FIG. 6) in the same direction, An erection bar 13 installed horizontally on the road R side from the column 12 and a plurality of beacon heads (light emitting and receiving devices) 8 fixed at positions corresponding to the lanes R1 to R4 in the erection bar 13 are provided.

Each beacon head 8 is connected to the traffic signal controller 1a and is collectively controlled by the controller 1a.
Inside each beacon head 8, a light emitting diode 14 and a photodiode 15 (see FIG. 7) are mounted. The light emitting diode 14 emits near-infrared light toward the upstream side of the lanes R1 to R4, so that the communication area A for performing optical wireless communication with the in-vehicle device 2 is the beacon. It is set on the upstream side of the head 8 (right side in FIG. 6).

FIG. 7 is a side view showing the communication area A of the optical beacon 11.
As shown in FIG. 7, the communication area A includes a downlink area DA in which the photodiode of the in-vehicle head 210 can receive downlink light (an area in which solid line hatching is provided in FIG. 7) DA, and a photo of the beacon head 8. The diode 15 is composed of an uplink area (area provided with a hatched area in FIG. 7) UA that can receive the uplink light UO.

According to the “near-infrared interface standard” of the optical beacon (optical vehicle sensor) 4, the uplink area UA overlaps with the upstream part (the right part in FIG. 7) 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 coincides with 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. 7, the upstream end c ′ of the downlink area DA may be positioned further upstream (right side in FIG. 7) than the upstream end c of the uplink area.

[Contents of bidirectional optical wireless communication]
FIG. 8 is a sequence diagram of bidirectional optical wireless communication performed between the beacon head 8 and the in-vehicle head 210. Hereinafter, the contents of this bidirectional optical wireless communication will be described with reference to FIG.
First, the control unit 101 of the traffic signal controller 1a uses the beacon heads 8 corresponding to the lanes R1 to R4 to obtain the first downlink information 34 including the lane notification information as the first information before downlink switching. , The transmission continues to the downlink area DA of each lane R1 to R4 at a predetermined transmission cycle (F1 in FIG. 8). At this stage, the vehicle ID is not yet stored in the lane notification information.

When the vehicle 5 enters the actual downlink area DA, the in-vehicle head 210 of the in-vehicle device 2 receives the first downlink information 34 including the lane notification information (no vehicle ID).
At this time, the processing unit 209 of the in-vehicle device 2 recognizes that the vehicle 5 exists in the actual communication area A. Thereafter, the processing unit 209 starts transmission of the uplink information 35 (F2 in FIG. 8), and transmits this uplink information 35 to the beacon head 8 at a predetermined transmission cycle (uplink transmission cycle) (FIG. 8). 8 F3).

When the processing unit 209 of the in-vehicle device 2 stores a specific vehicle ID for the vehicle 5 in the uplink information 35 and transmits the uplink information 35 and has travel time information between beacons, This information is also included in the uplink information 35.
Further, the processing unit 209 of the in-vehicle device 2 stores the uplink information 35 until the control unit 101 of the traffic signal controller 1a that is also a controller on the optical beacon 11 side recognizes that switching of the downlink has been performed. Keep sending.

  On the other hand, when the beacon head 8 of the optical beacon 11 receives the uplink information 35 (F4 in FIG. 8), the control unit 101 performs downlink switching and includes lane notification information having vehicle ID information as the second information. Then, the transmission of the second downlink information 36 is started (F5 in FIG. 8), and the transmission of the second downlink information 36 is repeated as much as possible within a predetermined time (F6 in FIG. 8).

The lane notification information includes a field for storing a vehicle ID for each lane R1 to R4 (FIG. 2), and a lane number can be assigned to each vehicle ID. For this reason, the processing unit 209 of the in-vehicle device 2 of each vehicle 5 that travels in different lanes R1 to R4 determines which vehicle ID of the vehicle is included in the storage field, thereby determining which vehicle is It can be recognized whether the vehicle is traveling in lanes R1 to R4.
The second downlink information 36 includes traffic information, section travel time information, event regulation information, and support information for safe driving support for the driver, in addition to the lane notification information including the vehicle ID. The support information includes signal information and travel position information.

Among these, the signal information is timing information at which the lamp color (blue, red, yellow, blue arrow, etc.) of the signal lamp 1b downstream from the optical beacon 11 changes.
The travel position information is information regarding the actual travel position of the vehicle 5 (passage position with respect to the communication area A) when the beacon passes. In the present embodiment, the upstream end c (see FIG. 7) of the uplink area UA is set as the reference position, and this reference position c is regarded as the passing position of the vehicle 5 when the beacon passes. The travel position information also includes a distance L0 from the reference position c to a predetermined position P0 (for example, the stop line 40) downstream thereof.

As shown on the right side of FIG. 8, the second downlink information 36 includes a single or a plurality of minimum frames 37. According to the “near infrared interface standard”, the data amount of the minimum frame 37 is defined as a total of 128 bytes, and 5 bytes are allocated to the header portion 38 and 123 bytes are allocated to the actual data portion 39.
According to the standard, the second downlink information 36 can be composed of 1 to 80 minimum frames 37, and the transmittable time is set to 250 ms. The downlink information 36 includes an arbitrary number of minimum frames 37 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 37 is about 1 ms. Therefore, for example, when one downlink information 36 is constituted by three minimum frames 37, the transmission period of the downlink information 36 is about 3 ms. Therefore, the downlink information 36 has a predetermined transmittable time (250 ms). ) Will be repeatedly transmitted about 80 times during this period.
The processing unit 209 of the in-vehicle device 2 recognizes the downlink switching in the optical beacon 11 at the time of receiving the second downlink information 36 (F7 in FIG. 8), and transmits the uplink information 35 at this time. Stop.

When receiving the second downlink information 36, the processing unit 209 of the in-vehicle device 2 extracts the signal information and the traveling position information from the information 36 and performs position location (F8 in FIG. 8), and based on the information. Provide safe driving support to the driver.
For example, when the processing unit 209 of the in-vehicle device 2 detects that the downstream signal lamp 1b will soon become a red signal based on the signal information, the display unit 207 and the audio output unit 208 notify the driver accordingly. Or a deceleration for stopping before the stop line 40 is calculated from the distance L0 included in the travel position information and the current travel speed of the vehicle 5, and the vehicle 5 is braked with the deceleration to stop the line 40. Safe driving support can be executed by forcibly stopping the vehicle before.

  In the present embodiment, the processing unit 209 of the in-vehicle device 2 is always captured by the GPS processing unit 201 based on the passing position (reference position c) in the traveling position information included in the downlink information 36. It has a function of correcting the vehicle position for correcting positioning data.

[Vehicle position abnormality determination process]
FIG. 9 is a side view of the optical beacon 11 and the roadside radio 10 for showing the contents of the vehicle position abnormality determination process performed by the control unit 101 of the traffic signal controller 1a. Hereinafter, the abnormality determination process of the present embodiment will be described with reference to FIG.
As shown in FIG. 9 (a), first, the control unit 101 of the traffic signal controller 1a determines the beacon head 8 based on the uplink optical UO received by the beacon head 8 used for the exchange of optical wireless communication. The passing position X0 of the vehicle 5 with respect to the communication area A is specified.

That is, as described above, the upstream end c of the uplink area UA is regarded as the actual passing position X0 of the vehicle 5 when the beacon passes, and at the light receiving time t0 when the beacon head 8 receives the uplink light UO from the in-vehicle device 2. It is estimated that the vehicle 5 is at the passing position X0.
Thereafter, for example, as shown in FIG. 9B, within a predetermined time after the light reception time t0 (for example, within 2 seconds), the uplink signal S5 from the vehicle 5 in which the passing position X0 is specified is transmitted to the roadside receiver. 10 receives, the control part 101 of the traffic signal controller 1a extracts the information regarding the own vehicle position X1 contained in the uplink signal S5.
Note that the association between the uplink light UO and the uplink signal S5 is performed based on the vehicle ID included in both.

Then, the control unit 101 of the traffic signal controller 1a uses the passing position X0, which is more accurate position information, to determine whether there is an abnormality in the own vehicle position X1 that the in-vehicle device 2 of the vehicle 5 has autonomously. Determine.
Specifically, the control unit 101 determines the difference between the passing position X0 and the own vehicle position X1 from the reception time (first time) t0 of the uplink optical UO to the reception time (second time) t1 of the uplink signal S5. It is determined whether or not the host vehicle position X1 is abnormal by comparing with the travel distance traveled by the vehicle 5 until then.
That is, the control unit 101 compares the absolute value of (X1−X0) with V × (t1−t0) (where V is the traveling speed of the vehicle), for example, the absolute value is V × (t1−T1). If it is greater than t0), it is determined that the vehicle position X1 of the vehicle 5 is abnormal, and if it is less than that, it is determined that the vehicle position X1 of the vehicle 5 is normal.

As the traveling speed V of the vehicle 5, a set value recorded in advance in the storage unit 104 is used. Alternatively, the traveling speed V can also be set variably by determining the traffic jam situation on the road R based on the number of passing vehicles obtained from the vehicle detector 3. Further, the traveling speed V of the vehicle 5 may be actually measured on the road side by the method described in the second embodiment to be described later. Further, the vehicle speed autonomously possessed by the vehicle 5 may be included in the uplink light UO or the uplink signal S6, and the traveling speed V of the vehicle 5 may be notified to the road side.
Next, when it is determined that the host vehicle position X1 is abnormal, the control unit 101 of the traffic signal controller 1a reduces the information of the determination result and the vehicle ID of the vehicle 5 to be determined. The downlink signal S6 included in the link signal S6 is broadcasted to the communication area through the roadside communication device 10.

  Thus, according to the communication system of the present embodiment, the control unit 101 of the traffic signal controller 1a that is a roadside infrastructure device is based on the uplink light UO transmitted from the in-vehicle device 2 to the beacon head 8. The passing position X0 of the vehicle 5 is identified, and based on the difference between the passing position X0 of the vehicle 5 thus identified and the own vehicle position X1 of the vehicle 5 included in the uplink signal S5, Since the quality is determined, the abnormality of the own vehicle position X1 that the in-vehicle device 2 of the vehicle 5 autonomously has can be determined on the road side.

  Then, according to the communication system of the present embodiment, when the own vehicle position X1 of the vehicle 5 is abnormal, the control unit 101 transmits the downlink signal S6 including the determination result and the vehicle ID corresponding thereto. Since the broadcast is transmitted to the communication area of the roadside communication device 10, the vehicle 5 as the determination target can be notified of the malfunction of the position evaluation function of the own vehicle. The presence of the vehicle 5 whose position X1 is inaccurate and its vehicle ID can be notified.

For this reason, in the case of the vehicle 5 to be determined, for example, the determination result is output by the display unit 207 or the audio output unit 208 to warn the passenger of a failure of the position evaluation function of the in-vehicle device 2 or the like. be able to.
Further, in the case of another vehicle 5, for example, by adopting an operation of ignoring the radio signal S6 from the vehicle 5 having a bad determination result, it is based on the information of the wrong own vehicle position X1. It is possible to prevent the cooperation system between vehicles from continuing.

[Second Embodiment]
FIG. 10 is a side view of the optical beacon 11 and roadside communication devices 10A and 10B used in the position determination system of the second embodiment.
The difference between the second embodiment and the first embodiment is that the traveling speed V of the vehicle 5 is measured on the road side by using a Doppler shift generated between the signal frequencies received by the two roadside radio devices 10A and 10B. It is in the point which made it possible.

That is, in the present embodiment, two roadside radio devices 10A and 10B are installed at positions separated in the vehicle traveling direction, and the first roadside radio device 10A is installed at a far position downstream of the beacon head 8. The second roadside radio device 10B is installed in the proximity position on the downstream side of the beacon head 8.
Here, the original frequency of the uplink signal S5 transmitted by the in-vehicle device 2 of the vehicle 5 is ν0, the frequency received by the first roadside radio 10A is νA, and the frequency received by the second roadside radio 10B is νB. If the speed of light is c, νA and νB can be calculated by the following equation (1), respectively.

Therefore, taking the difference between νA and νB, the following equation (2) is obtained.

In the above equations (1) and (2), θA and θB are relative to the roadside radio devices 10A and 10B as viewed from the vehicle 5 passing through the communication area A of the beacon head 8, as shown in FIG. This is the elevation angle, and this value can be determined in advance as a set value if the installation locations of the roadside radio devices 10A and 10B are determined.
Accordingly, if the frequencies νA and νB measured by the roadside radio devices 10A and 10B are substituted into the equation (2), the traveling speed V can be actually measured on the roadside.

[Third Embodiment]
FIG. 11 is a plan view of the optical beacon 11 used in the position determination system of the third embodiment, and FIG. 12 is a side view showing the communication area A of the optical beacon 11.
As shown in FIGS. 11 and 12, in this embodiment, the optical beacon 11 is of the so-called “PD split type”, and the entire distance from the downstream end b of the uplink area UA to the upstream end c of the area UA. Is set longer to the upstream side and the downstream side than the above definition. As a result, the uplink area UA extends in the vehicle traveling direction from the above definition, and the downlink area DA also extends in the vehicle traveling direction from the above definition.

Thus, if the uplink area UA and the downlink area DA are widened, the certainty of transmission / reception of the uplink information 35 and the downlink information 34 and 36 between the in-vehicle device 2 and the optical beacon 4 is increased. The accuracy of the travel position information (passing position X0 and distance L0) decreases.
Therefore, in the present embodiment, the uplink area UA is divided into a plurality of divided areas UA1 to UA4 arranged in the vehicle traveling direction so that the passing position X0 can be specified as accurately as possible.

Specifically, the uplink area UA of the present embodiment is divided into four in total by three boundary lines (boundary portions) BL having the position d as the upper end and the positions e1 to e3 on the road R as the lower ends. ing. In the present embodiment, as shown in FIG. 12, the reference positions P1 to P4 of the divided areas UA1 to UA4 are set at intermediate points of the areas.
Also, inside the beacon head 8, four photodiodes 15A to 15D having the respective divided areas UA1 to UA4 of the uplink area UA as light receiving areas are accommodated.

Therefore, for example, if the in-vehicle head 210 transmits the uplink light UO in the divided area UA1 located on the most upstream side, the uplink light UO (solid arrow in FIG. 12) corresponds to the divided area UA1. Light is received by the photodiode 15A.
When the photodiode 15A corresponding to the upstream area UA1 receives the uplink light UO and is recognized as the uplink information 35 by the control unit 101 of the traffic signal controller 1a, the traffic signal controller 1a The control unit 101 specifies the reference position P1 corresponding to the most upstream divided area UA1 as the passing position X0 of the vehicle 5, selects the distance L1 from the reference position P1 to the predetermined position P0, and sets the downlink position After switching, the reference position P1 and the distance L1 are included in the second downlink information 36, and the downlink light DO is transmitted from the light emitting diode 14 to the in-vehicle device 2.

Moreover, when the uplink information 35 is acquired by the uplink light UO received by the photodiodes 15B to 15D corresponding to the other divided areas UA2 to UA4, the control unit 101 of the traffic signal controller 1a has the divided area UA2 The reference positions P2 to P3 and the distances L2 to L4 corresponding to UA4 are selected, are included in the second downlink information 36, and the downlink DO is transmitted from the light emitting diode 14 to the in-vehicle device 2.
When such a PD split type optical beacon 11 is used, even if the uplink area UA is set longer in the vehicle traveling direction in order to improve the opportunity of receiving the uplink light UO, the individual divided areas UA1 to UA4 are This can be set narrowly in the vehicle traveling direction.

Then, according to the PD split type optical beacon 11, by determining which one of the plurality of photodiodes 15 actually receives the uplink light UO, the traveling vehicle 5 (on-vehicle device 2) It can be identified on the road side which of the divided areas UA1 to UA4 has emitted the uplink light UO.
Therefore, in the roadside control unit 101, the passing position X0 of the vehicle 5 (on-vehicle device 2) that has emitted the uplink light UO can be obtained with an accuracy equal to or less than the vehicle traveling direction length of each of the divided areas UA1 to UA4. The accuracy of the evaluation of the passing position X0 performed in step 1 is improved.

  When the PD split type optical beacon 11 is used, the vehicle 5 is detected by detecting the change rate of the light receiving position of the uplink light UO with respect to the photodiodes 15A to 15D corresponding to the divided areas UA1 to UA4. There is also an advantage that the traveling speed V can be measured on the road side.

[Other variations]
The embodiments disclosed thus far are all illustrative and not restrictive. The scope of the present invention is indicated by the scope of claims for patent, and all modifications within the scope equivalent to the structure of the claims for patent are included in the present invention.
For example, in each of the above-described embodiments, the control unit 101 of the traffic signal controller 1a performs the abnormality determination process. However, the main body of the abnormality determination process is not particularly limited as long as the processing subject is the roadside. The control unit 401 may be a beacon controller that individually controls the optical beacon 11.

It is a schematic diagram which shows the whole structure of a traffic signal control system. It is a road top view which shows the outline | summary of a traffic signal. It is a block diagram which shows the structure of a central apparatus. It is a block diagram which shows the structure of a traffic signal controller. It is a block diagram which shows the structure of a vehicle-mounted apparatus. It is a top view of the optical beacon which has a beacon head. It is a side view which shows the communication area | region of an optical beacon. It is a sequence diagram of bidirectional optical wireless communication. It is a side view of an optical beacon and a roadside radio for showing abnormality judging processing of a self-vehicle position of vehicles. It is a side view of the optical beacon and roadside communication apparatus which are used for the position determination system of 2nd Embodiment. It is a top view of the optical beacon used for the position determination system of a 3rd embodiment. It is a side view which shows the communication area | region of the said optical beacon.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Traffic signal device 1a Traffic signal controller 101 Control part 101A Position specific | specification part 101B Position determination part 101C Transmission control part 2 In-vehicle apparatus 5 Vehicle 8 Beacon head 10 Roadside communication apparatus 11 Optical beacon 14 Light emitting diode (light emitting element)
15 Photodiode (light receiving element)
A Communication area UA Uplink area UA1-UA4 Divided area DA Downlink area UO Uplink light DO Downlink light S5 Uplink signal (Radio signal)
S6 Downlink signal (radio signal)
X0 Passing position X1 Own vehicle position t0 Reception time (first time)
t1 Reception time (second time)
V Traveling speed

Claims (6)

A position determination system for determining, on the road side, an abnormality in the position of the vehicle that the in-vehicle device of the vehicle corresponding to both optical wireless communication and radio wave wireless communication has autonomously,
A beacon head in which a communication area for performing optical wireless communication with the in-vehicle device is set to a predetermined range of the road,
A radio wave including information relating to the position of the vehicle of the vehicle, which has a communication area for performing radio wave wireless communication with the vehicle-mounted device and is transmitted by the vehicle-mounted device after optical wireless communication with the beacon head A roadside communicator capable of receiving uplink signals consisting of signals,
A position specifying unit for specifying a passing position of the vehicle with respect to the communication area based on uplink light received by the beacon head;
A position determination unit that determines whether the vehicle position is abnormal based on a difference between the identified passing position and the vehicle position included in the uplink signal;
A position determination system comprising:   When the position determination unit determines that the vehicle position is abnormal, a transmission control unit that broadcasts a downlink signal including a radio signal including the determination result toward the communication area to the roadside communication device, The position determination system according to claim 1, further comprising: The position determination unit compares the difference between the passing position and the own vehicle position with a travel distance traveled by the vehicle between the next first time and the second time, so that the own vehicle position is determined. The position determination system according to claim 1 or 2, wherein it is determined whether or not there is an abnormality.
(A) First time when the beacon head receives the uplink light (b) Second time when the roadside communication device receives the uplink signal from the in-vehicle device of the same transmission source as the uplink light The beacon head has one light receiving element that receives uplink light from the in-vehicle device in an uplink region included in the communication region,
The position determination system according to any one of claims 1 to 3, wherein the position specifying unit specifies a reference position set in the uplink region as a passing position of the vehicle. The beacon head has a plurality of light receiving elements each having a light receiving area corresponding to each divided area obtained by dividing the uplink area included in the communication area in the vehicle traveling direction;
The said position specific | specification part specifies the reference position set to the said division area corresponding to the said light receiving element which received the said uplink light among several said light receiving elements as a passing position of the said vehicle. The position determination system according to any one of the above. It is a position determination method in which an abnormality of the own vehicle position autonomously possessed by the in-vehicle device of the vehicle corresponding to both optical wireless communication and radio wave wireless communication is determined on the road side,
Based on the uplink light transmitted by the in-vehicle device to the beacon head, the passing position of the vehicle with respect to the communication area of the beacon head is specified on the road side,
The vehicle-mounted device transmits after the optical wireless communication with the beacon head, receives a radio signal including information on the vehicle position of the vehicle on the road side,
A position determination method, wherein, based on a difference between the specified passing position and the own vehicle position included in the received radio signal, it is determined on the road side whether or not the own vehicle position is abnormal.

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