JP2003123189A - Communication system between road and vehicle and receiver on vehicle side - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a communication system between road and vehicle by which an erroneous reception is simply prevented from occurring. SOLUTION: The navigator ECU for vehicle navigation judges which road the present position of a vehicle detected by a position detector belongs to on road data (steps S1 to S7). When judging that the beacon of VICS is installed on a road which the vehicle travels presently based on road information received from the beacon, (step S7, 'YES'), the navigator ECU effectively processes a data frame received from the beacon (step S8).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roadside transmitter which is installed on a road and transmits a radio wave signal to a vehicle side, and a vehicle side receiver which is mounted on a vehicle and receives a radio wave signal transmitted from the roadside transmitter. And a vehicle-side receiver used in the system.

[0002]

DISCLOSURE OF THE INVENTION For example, DSRC (Ded
icated Short Range Communication: dedicated narrow band communication)
VICS (Veh
icle Information and Communication System), ETC
Services such as (Electronic Toll Collection) are already in operation, and in the future, AHS (Advanced Crui
se-Assist Highway System) is planned to start. All of these services are mainly for expressways, and roadside devices (roadside transmitters) are mainly installed on highways.

Therefore, for example, as shown in FIG. 4, when the highways 2 and 3 are laid on the general road 1 by an elevated structure, or when the highway and the general road run in parallel. Expressway 2 or 3
The radio signal transmitted from the on-road unit 4 installed in
There is a problem that it is received by the vehicle-mounted device (vehicle-side receiver) of the vehicle 5 traveling on the general road 1 that is not the service target.

As a measure to deal with such a problem, at present, it is necessary to install a roadside device at a position where leakage of electric waves to other roads is minimized or to arrange an electromagnetic wave absorbing material at a necessary place. And so on. The former is premised on allowing a certain degree of radio wave leakage, and the latter increases the cost because the radio wave absorber is expensive, and it cannot be said that they are sufficient measures. .

In addition to these, as possible measures, the radiation beam of the radio signal transmitted from the roadside machine is narrowed down to improve the directivity, and the roadside machine number included in the transmission signal of the roadside machine is systematized for each installed road. A plan to make a decision on the in-vehicle device side is under consideration. However, in the former case, it is expected that the transmission antenna of the roadside machine will become larger or more expensive, and in the latter case, a database for identifying the roadside machine number must be constructed in advance and placed on the vehicle side. Therefore, each of them has its own demerits when it is actually attempted.

Further, for example, in the technique disclosed in Japanese Patent Laid-Open No. 9-16888, the type of road on which the vehicle is currently traveling is determined, and if the road is a general road, the light transmitted from an optical beacon (roadside device) is used. The above problem is dealt with by receiving a signal and receiving a radio signal transmitted from a radio beacon (on-road device) on a highway. However, since the actual installation modes of the optical beacon and the radio beacon are not clearly classified according to the road type, in the above-described conventional technology, it is not always possible to correctly obtain the received signal corresponding to the road type. .

The present invention has been made in view of the above circumstances, and an object of the invention is to provide a road-vehicle communication system capable of preventing occurrence of erroneous reception more easily, and a vehicle-side receiver used in the system. To provide.

[0008]

According to the road-to-vehicle communication system of the first aspect, the roadside transmitter transmits road information for identifying the road on which the roadside transmitter is installed to the vehicle side. Then, the road determination means of the vehicle-side receiver determines which road on the road data the current position of the vehicle detected by the position detection means belongs to, and the signal processing means
When it is determined that the roadside transmitter is installed on the road on which the vehicle is currently traveling based on the received road information, the signal received from the roadside transmitter is effectively processed.

Therefore, it is possible to accurately determine whether or not the roadside transmitter that has transmitted the signal is installed on the road on which the vehicle is currently traveling, and the roadside transmitter is installed on a different road. This makes it possible to reliably avoid accidentally receiving a radio signal transmitted from a roadside transmitter.

According to the road-to-vehicle communication system of the second aspect, when the signal processing means of the vehicle-side receiver receives the transmitter number transmitted from the road-side transmitter, the number must be stored in the storage means. For example, the number and road information are stored in the storage means. Then, if the received transmitter number is already stored, the road information corresponding to that number is read from the storage means to make the determination.

For example, in the data transmitted from the roadside transmitter in VICS, the transmitter number is transmitted for each frame, but the VICS link corresponding to the road information is expressed by the formula 1
Transmission is performed only once every 0 to 100 frames. Therefore, according to the second aspect, when the transmitter number and the corresponding road information are stored in the storage means, the signal processing means does not wait until the road information is received from the storage means. Can be read and retrieved,
It is possible to quickly start the received signal processing.

Further, the vehicle-side receiver according to claim 3 has the position detecting means and the road data storing means, but these means are also generally included in the vehicle navigation device. Further, with respect to the road determination means and the signal processing means, it is possible to easily provide the control unit such as a microcomputer constituting the vehicle navigation device with those functions. Further, most of the information transmitted to the vehicle side by road-to-vehicle communication is related to vehicle navigation. Therefore, as in the vehicle-side receiver according to claim 4, if some of the components are shared with the vehicular navigation device, the vehicular navigation device can be efficiently configured by adding other necessary functions. You can

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment in which the present invention is applied to a VICS which is a road-vehicle communication system will be described below with reference to FIGS. FIG. 3 is a functional block diagram showing the electrical configuration of the vehicle navigation device. The vehicle navigation device 11 includes a position detector (position detection means) 12, a map data input device (road data storage means) 13, an operation switch group 14, and a navigation ECU (Electronic Control Unit, road determination means) connected to these. Signal processing means) 15, VICS receiver 16 connected to navigation ECU 15, display device 17, and external memory 18
Is equipped with.

The navigation ECU 15 is composed of a microcomputer, and has a well-known CP inside.
U, ROM (storage means) 15a, RAM (storage means) 1
5b, I / O, (not shown except ROM 15a, RAM 15a), a bus line for connecting these, and the like.

The position detector 12 is a gyroscope 1
9, vehicle speed sensor 20, GPS (Grobal Positioning Syste
m) A GPS receiver 21 for detecting the position of the vehicle based on the radio signal transmitted from the satellite is provided. Since each of these configurations 19 to 21 has an error based on its own property, the configurations 19 to 21 are configured to be used while interpolating the output results of each other. Depending on the required accuracy, some of these may be used, or a geomagnetic sensor, a vehicle steering sensor, etc. may be further added.

The map data input device 13 is a device for inputting various data including so-called map matching data for improving position detection accuracy and map data.
It is configured by including a CD-ROM, a DVD-ROM and the like. Map data includes road data, place names,
It consists of other data such as topography and buildings. Road data is
The links in the road map are divided into straight lines at predetermined distances and are stored as a unit. The link number is the identification number of each link, and the node coordinates are the coordinates of both end points of each link. , "Link direction" indicating the direction of each link, "connection information" indicating the link ID of another link connected to each link, "link attribute" indicating the type of road to which each link belongs, etc. .

The VICS receiver 16 includes an optical beacon receiver 22 and a radio beacon receiver 23. The optical beacon receiving unit 22 receives a light (infrared) signal mainly transmitted from an optical beacon installed in the vicinity of a general road by a light receiving element such as a photodiode, and the radio beacon receiving unit 23 mainly An antenna receives a radio wave signal transmitted from a radio wave beacon (roadside transmitter) installed near a highway. These transmitted signals are signals in digital form containing traffic information.

The information contained in the beacon signal received by any of the receivers 22 and 23 is transmitted to the navigation ECU 15 side as digital data and written in the reception buffer set in the RAM 15b by the navigation ECU 15. It has become. In addition, these receivers 2
2 and 23 are configured to transmit a response signal (upling data) to the beacon side as necessary (the former includes a transmission LED).

The information transmitted by the beacon signal includes traffic information such as highways, general roads, parking lots, and information specific to each beacon. The former traffic information includes traffic congestion information such as traffic congestion points and traffic congestion sections, required time information between major points, traffic obstacle information such as accidents, broken vehicles, road obstacles, construction and work, road closures, speed restrictions, and lane restrictions. It includes traffic regulation information including temporary regulations and their causes, and parking lot information on parking lots, service areas, and vacant conditions in parking areas. The latter information unique to each beacon includes the roadside machine number (transmitter number) uniquely assigned to each beacon and the VIC of the road on which each beacon is installed.
There is an S link ID and a direction of the link ID.

On the screen of the display device 17, the position detector 12
The mark indicating the current position of the vehicle input by the map data, the map data input by the map data input device 13, and the additional data such as the guide route displayed on the map and the guide route and the mark of the set point are superimposed. It is designed to be displayed. The operation switch group 14 includes, for example, a touch switch or a mechanical switch arranged integrally with the display device 17, and is used for various inputs. Then, in the navigation device 11, when the position of the destination is input by the operation switch group 14, the navigation ECU 15 automatically selects the optimum route from the current position of the vehicle to the destination, and calculates the guide route, The route guidance information is displayed on the display device 17.

The external memory 18 is composed of, for example, an IC card reader / writer, and the navigation ECU 1
The information acquired by 5 can be written and stored in the IC card, and the information stored in the C card can be read by the navigation ECU 15. In the above configuration, the position detector 12 and the map data input device 1
3. The navigation ECU 15 and the radio beacon beacon receiver 23 of the VICS receiver 16 constitute a vehicle-side receiver 24.

Next, the operation of this embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a flow chart showing the processing contents by the navigation ECU 15, and shows only the part related to the gist of the present invention. First, the navigation ECU 15 determines whether or not the vehicle has entered the beacon signal reception area (step S1). The judgment here is, for example, VICS.
This is performed depending on whether the received power level in the receiver 16 is above a predetermined level, or whether the number of normal received frames is above a predetermined number.

When it is determined in step S1 that the vehicle has entered the reception area ("YES"), the navigation ECU 15
Sends the signal transmitted from the beacon to the VICS receiver 16
(Step S2).

FIG. 2 shows the structure of the data frame 25 of the beacon signal. The data frame 25 includes a synchronization code 26, a header part 27, an actual data part 28 and a CR.
It is composed of a C (Cyclic Redundancy Cord) 29. The synchronization code 26 is a code for synchronizing the road-to-vehicle communication, and the header section 27 is a data header including the above-mentioned road machine number and the like. The actual data section 28 is data including current position information, road traffic information, etc.
Is a code used for error detection.

The data frame 25 is transmitted from the beacon in 38 to 76 frames as one cycle. The VICS is set so that a reception period of about 3 cycles can be secured while the vehicle passes through the beacon reception area.

Referring again to FIG. 1, the navigation ECU 15
When the data frame 25 is received in step S2, the internal RAM 15b is referred to, and it is determined whether or not the roadside machine number included in the header portion 27 of the data frame 25 is already registered in the RAM 15b (step S3). . Then, if the road machine number is not registered (“NO”), it is determined whether or not the installation location information (link ID) is included in the actual data section 28 (step S4).

That is, in the VICS, the link ID, which is the information on the road where the beacon is installed, is transmitted only about once out of several tens of frames transmitted in one cycle. Therefore, since the installation location information is not always included in the data frame 25 received in step S2, if the installation location information is not included (step S4, “NO”), the process returns to step S1 and a new operation is performed. Data frame 25 is received.

Then, in step S4, if the received data frame 25 includes the installation location information ("YES"), the navigation ECU 15 outputs the roadside machine number and the installation location information of the data frame 25 to the internal RAM1.
5b is written and registered (step S5). Then, the process proceeds to the next step S6, and the installation location information of the beacon is compared with the road on which the vehicle is currently traveling.

In step S6, the navigation ECU 15
Indicates whether the road on which the beacon transmitting the data frame 25 is installed and the road on the map corresponding to the current position of the vehicle detected by the position detector 12 match (whether the roads are the same). ) It is determined whether or not (step S)
7). Various determination methods can be considered depending on the format of road data in the map data input device 13. For example, when the same road ID as the VICS is added to the road data of the map data input device 13, it may be determined whether or not the link IDs of the two match. Alternatively, if the VICS link ID is not assigned to the road data side, it is determined whether the road attributes match. For example, if the road attributes of the data frame 25 and the road data side are both "highway", it may be determined that they match.

When it is determined in step S7 that both roads are on the same route ("YES"), the navigation ECU 15 considers that the received data frame 25 is valid and continues the process (step S8). . That is,
Based on the content of the actual data section 28, processing such as displaying the transmitted traffic information on the display device 17 is performed. on the other hand,
If it judges that both roads are not the same route ("N
O ”), the navigation ECU 15 receives the data frame 2
5 is considered invalid and the processing is stopped (step S
9). That is, the data frame 25 is discarded.

As a result of performing the processing in steps S3 to S5, the data frame 2 received in step S3 is received.
If the on-road machine number included in 5 is already registered in the RAM 15b (“YES”), the navigation ECU 15
Since it suffices to read the corresponding installation location information registered in the RAM 15b, the process proceeds to step S6 and the information is collated.

Further, if the data content of the RAM 15b is not retained when the vehicle navigation device 11 is powered off, the power source OF is turned off.
The data written in the RAM 15b in the F processing is RO
Data may be transferred to M (in this case, EEPROM) 15a for backup, or data may be written to the ROM 15a from the beginning. Further, when a hard disk device or the like is separately provided, the data may be written in the hard disk.

As described above, according to the present embodiment, the navigation ECU 15 of the vehicular navigation device 11 determines which road on the road data the current position of the vehicle detected by the position detector 12 belongs to. , If it is determined that the beacon is installed on the road on which the vehicle is currently traveling based on the road information received from the VICS beacon, the data frame 25 received from the beacon is effectively processed. . Therefore, data frame 2
It is possible to accurately determine whether the beacon that transmitted 5 is installed on the road where the vehicle is currently traveling, and the radio wave transmitted from the beacon installed on a different road. It is possible to surely avoid receiving the signal by mistake.

Further, according to the present embodiment, the navigation ECU 15
When receiving the road unit number transmitted from the beacon,
If the number is not registered in the RAM 15b, the road unit number and the road information are registered. If the received road unit number is already registered, the road information corresponding to the number is read from the RAM 15b, and the data frame is read. The beacon transmitting 25 is determined whether or not the beacon is installed on the road on which the vehicle is currently traveling.

That is, in the data transmitted from the beacon in VICS, the road unit number is transmitted for each frame, but since the VICS link is transmitted only once per cycle, By processing
If the roadside machine number and the road information are stored in the RAM 15b, the RAM 15b does not have to wait until the road information is received.
It can be read and acquired from 15b, and the reception signal processing can be started quickly.

Since the vehicle-side receiver 24 is constructed integrally with the vehicle navigation device 11, the components such as the position detector 12 as the position detecting means and the map data input device 13 as the road data storing means are made common. The navigation ECU 15 can also be configured to have those functions as well as the road determination means and the signal processing means. Further, since the traffic information transmitted to the vehicle side in the VICS is information related to the navigation of the vehicle, the vehicle side receiver 24 can be efficiently configured by integrating the two.

The present invention is not limited to the embodiments described above and shown in the drawings, and the following modifications or expansions are possible. The vehicle-side receiver is not limited to being integrally formed with the vehicle navigation device, but may be a vehicle-side receiver alone. In that case, the road data storage means may store only road data. The processes in steps S3 and S5 may be executed as necessary. The position detecting means may be composed of only the GPS receiver 21. Further, if it is possible to intermittently correct the deviation from the absolute position, the position detector 12 detects the GPS
The receiver 21 may be excluded. The function of the signal processing means may be provided on the VICS receiver 16 side. The present invention is not limited to VICS, and can be applied to any road-to-vehicle communication system in which information about the current position of the vehicle is transmitted from the roadside transmitter to the vehicle side.

[Brief description of drawings]

FIG. 1 is a flow chart showing an embodiment of the present invention, the processing contents of a portion related to the gist of the present invention by a navigation ECU constituting a vehicle navigation device;

FIG. 2 is a diagram showing a structure of a data frame of a beacon signal.

FIG. 3 is a functional block diagram showing an electrical configuration of a vehicle navigation device.

FIG. 4 is a perspective view showing a state in which a highway is laid on an ordinary road by an elevated structure in the prior art.

[Explanation of symbols]

Reference numeral 11 is a vehicle navigation device, 12 is a position detector (position detection means), 13 is a map data input device (road data storage means), 15 is a navigation ECU (road determination means, signal processing means), and 15a is a ROM (storage). Means), 15b is R
AM (storage means), 24 is a vehicle-side receiver.

Continued front page    F-term (reference) 2F029 AA02 AB01 AB07 AC02 AC14                       AC19 AD07                 5H180 AA01 BB02 BB04 CC12 EE03                       EE18 FF04 FF05 FF07 FF12                       FF13 FF14 FF22 FF27 FF33                 5K067 BB21 BB36 DD17 EE02 EE10                       HH23 JJ52 JJ56

Claims (4)

[Claims] 1. A roadside transmitter which is installed on a road and transmits a radio wave signal to a vehicle side, and a vehicle side receiver which is mounted on a vehicle and receives a radio wave signal transmitted from the roadside transmitter. In the road-to-vehicle communication system, the roadside transmitter transmits road information for identifying the road on which the vehicle is installed to the vehicle side, and the vehicle side receiver detects the current position of the vehicle. Position detection means, road data storage means in which road data is stored, and road determination means for determining which road on the road data the current position of the vehicle detected by the position detection means belongs to. When it is determined that the roadside transmitter is installed on the road determined by the road determination means based on the road information received from the roadside transmitter, the signal received from the roadside transmitter is determined. And a signal processing means for effectively processing the signal. 2. The roadside transmitter transmits the transmitter number assigned to itself to the vehicle side, and the vehicle side receiver has a storage means for storing the transmitter number and the road information. When the signal processing means receives the transmitter number, if the number is not stored in the storage means, the number and the road information are stored in the storage means, and the received transmitter number is The road-to-vehicle communication system according to claim 1, wherein when the information is already stored, the road information corresponding to the number is read from the storage means to make the determination. 3. A vehicle-side receiver used in the road-vehicle communication system according to claim 1. 4. The vehicle-side receiver according to claim 3, wherein some of the constituent elements are shared with the vehicular navigation device.