JP4080934B2 - Inter-vehicle communication system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an inter-vehicle communication system that transmits and receives various types of communication data between vehicles.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a vehicle-to-vehicle communication system that wirelessly connects a traveling vehicle and transmits and receives various types of communication data is known (see, for example, Patent Document 1). In this inter-vehicle communication system, a user who is on board a vehicle designates a region, and a near-vehicle communication mode and a far-field communication mode are used as two types of communication methods for communicating with a vehicle traveling in the region. I have. The near-vehicle communication mode is a communication method for transmitting and receiving communication data by wireless direct communication, and is used for communication with a relatively nearby vehicle. In the far-field communication mode, after specifying the area where the vehicle that is the communication partner exists, the telephone number of the vehicle running in this area is acquired, and communication data is transmitted / received by making a call using this telephone number. The communication method is used for communication with a relatively distant vehicle.
[0003]
When communicating with a specific vehicle using the above-mentioned near-vehicle communication mode, in principle, a vehicle that is traveling in a range where communication radio waves reach can be a communication destination. If communication data can be relayed, the communication range can be expanded.
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 10-47975 (pages 14-28, FIG. 1-44)
[0005]
[Problems to be solved by the invention]
By the way, in the conventional communication method for relaying communication data, it is generally necessary to specify a relay route in the transmission source terminal device, and for this purpose, a routing table necessary for setting the relay route is used. In a network using a wired telephone line or the like, the installation location of the relay device such as a router does not change in a short time, so the routing table created prior to communication is usually used until the communication is completed. There is no need to update. However, when considering a network in which communication data is relayed by a vehicle using the inter-vehicle communication system as shown in Patent Document 1, the position of the vehicle having the relay function changes from moment to moment. It becomes necessary to update the contents of the routing table at intervals. In this update process, for example, communication data including a confirmation message for collecting information necessary for content update is transmitted to neighboring vehicles by broadcast distribution each time, and communication data sent back from a neighboring vehicle capable of communication is transmitted. This is done by receiving and analyzing its contents. For this reason, when updating the contents of the routing table in a short cycle, there is a problem that the communication amount with surrounding vehicles increases and the communication band cannot be used effectively.
[0006]
The present invention was created in view of the above points, and an object of the present invention is to provide an inter-vehicle communication system capable of reducing the amount of communication and effectively using a communication band.
[0007]
[Means for Solving the Problems]
In order to solve the above-described problem, the inter-vehicle communication system of the present invention is equipped with communication data transmitted from a transmission source vehicle-mounted device mounted on another vehicle traveling around the vehicle on which the transmission source vehicle-mounted device is mounted. The transmission in-vehicle device detects route information storage means for storing route information related to the relay route via the relay terminal device and surrounding vehicles that enter and exit beyond a predetermined detection range. Vehicle detection means and route information update means for updating the contents of the route information stored in the route information storage means when the surrounding vehicle entering and exiting is detected by the vehicle detection means. Detecting the entry / exit of a surrounding vehicle by the vehicle detection means means that a change has occurred in the configuration of another vehicle that relays communication data, and by updating the contents of the route information at this detection timing, The change of the relay route can be reliably reflected in the route information. In particular, the content of route information is updated when the entry and exit of a nearby vehicle is detected, eliminating the need to update the content of route information at short predetermined intervals, reducing the amount of communication data transmitted and received between vehicles Thus, the communication band can be effectively used.
[0008]
Further, it is preferable that the above-described route information update unit updates the content of the route information by inquiring the state of another relay terminal device that cannot directly communicate with the relay terminal device that can directly communicate. As a result, it is possible to acquire information related to the relay terminal device mounted on another vehicle that cannot directly communicate, and it is possible to obtain route information in a wider range than a range in which direct communication is possible.
[0009]
In addition, the elapsed time after the above-described update of the route information by the route information update unit is measured, and the update is performed when a predetermined time has passed without the detection of the surrounding vehicle entering and exiting by the vehicle detection unit. It is desirable to further include an additional update determination unit that outputs an instruction, and the route information update unit preferably updates the content of the route information when an update instruction is output from the additional update determination unit. As a result, there is no change in the directly detectable vehicle, and it is possible to update the contents of the route information even when other surrounding vehicles have changed. In addition, it is considered that there is no inconvenience even if the time interval at this time is set to be relatively long (usually because the contents of the route information are updated at the detection timing of the vehicle), the communication amount greatly increases. Without any problem, the communication band can be effectively used.
[0010]
The vehicle detection means described above is preferably an in-vehicle radar device that is installed in front of and behind the host vehicle and detects other vehicles traveling in front of and behind the host vehicle. This makes it possible to detect other vehicles before and after the host vehicle with high accuracy and in a short time, and to reduce the processing load by detecting the vehicle without performing complicated post-processing. it can.
[0011]
Moreover, it is desirable that the vehicle detection means described above detects another vehicle that is traveling in the same direction as the host vehicle. Vehicles traveling in a different direction from the host vehicle are often excluded from the scope of detection because the distance to the host vehicle increases and the vehicle is often out of the communicable range of the host vehicle. However, it is considered that there is not much trouble with updating the contents of effective route information, and it is possible to further reduce the amount of communication and effectively use the communication band by reducing the number of vehicles to be detected.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an inter-vehicle communication network system according to an embodiment to which the present invention is applied will be described in detail with reference to the drawings.
The in-vehicle terminal device installed in each vehicle constituting the vehicle-to-vehicle communication network system of the present embodiment is in-vehicle terminal device installed in another vehicle capable of direct communication by wireless communication, or direct communication is possible although direct communication is not possible. A routing table storing routing information (route information) indicating a relay route when transmitting communication data via an in-vehicle terminal device mounted on another vehicle that can communicate indirectly via the in-vehicle terminal device It has.
[0013]
FIG. 1 is a diagram illustrating a configuration of an in-vehicle device 100 mounted on each vehicle constituting the inter-vehicle communication system according to an embodiment. As shown in FIG. 1, the in-vehicle device 100 includes an in-vehicle terminal device 10, a GPS device 20, in-vehicle radar devices 22 and 24, and an application processing device 200.
[0014]
The in-vehicle terminal device 10 transmits and receives various types of communication data by performing wireless communication with the in-vehicle terminal device 10 mounted on another vehicle. For this purpose, the in-vehicle terminal device 10 includes a terminal control unit 11, a memory 12, a transmission unit 13, a reception unit 14, and an antenna switching unit 15.
[0015]
The terminal control unit 11 controls the overall operation of the in-vehicle terminal device 10 by executing a predetermined operation program stored in the memory 12. For example, when this in-vehicle terminal device 10 operates as a transmission source terminal device (transmission source in-vehicle device), processing for creating and transmitting communication data including a predetermined message is performed. When the in-vehicle terminal device 10 operates as a transmission destination terminal device, processing for extracting a message included in the received communication data is performed. The in-vehicle terminal device 10 operates as a relay terminal device when it does not correspond to either the transmission source terminal device or the transmission destination terminal device, and relays communication data transmitted from another vehicle to another vehicle. Process.
[0016]
In addition to the operation program executed by the terminal control unit 11, the memory 12 stores a unique identification number assigned to the in-vehicle terminal device 10 and various user information. In the present embodiment, the memory 12 stores a routing table 30 necessary for setting a communication route (relay route) when communication data is transmitted from the in-vehicle terminal device 10.
[0017]
The routing table 30 includes routing information necessary for specifying a relay route when transmitting communication data to a specific in-vehicle terminal device 10 mounted on another vehicle. For example, in the present embodiment, the routing information includes the identification number of another in-vehicle terminal device 10 existing in the communicable range with respect to the host vehicle and its location (the position of the vehicle in which this in-vehicle terminal device 10 is mounted). ), And the identification number of another in-vehicle terminal device 10 existing within the communicable range for these vehicles and the location thereof.
[0018]
FIG. 2 is a diagram showing an outline of the routing table 30 included in the in-vehicle terminal device 10 mounted on each vehicle. For example, attention is paid to the in-vehicle terminal device 10 mounted on the vehicle A.
In the routing table 30 of the in-vehicle terminal device 10 mounted on the vehicle A, information on the other vehicles B1 to B4 (first-stage vehicles) that are traveling in a range in which the vehicle A can be directly communicated, and these Information relating to another vehicle (second-stage vehicle) that is traveling in a range that can directly communicate with each of the vehicles B1 to B4 and information indicating the connection between the first-stage vehicle and the second-stage vehicle are routed. Included as information. For example, as shown in FIG. 2, since the vehicles C1 to C3 travel within the communicable range of the vehicle B1, information related to the vehicles C1 to C3 that cannot be directly communicated from the vehicle A is also mounted on the vehicle A. Stored in the routing table 30 of the in-vehicle terminal device 10.
[0019]
Therefore, the in-vehicle terminal device 10 mounted on the vehicle A is mounted on all surrounding vehicles when sending communication data to a vehicle traveling in a specific place by referring to the routing table 30 described above. The communication data can be transmitted by designating one or a plurality of vehicles existing in a direction approaching a specific place, instead of performing broadcast delivery to the in-vehicle terminal device 10 and transmitting the communication data. .
[0020]
Moreover, the transmission part 13 shown in FIG. 1 performs the process which transmits the signal which modulated the transmission data output from the terminal control part 11 from the antenna 17 via the antenna switching part 15 toward another vehicle. The receiving unit 14 receives a signal transmitted from another vehicle and reaching the antenna 17 via the antenna switching unit 15 and performs a predetermined demodulation process. The antenna switching unit 15 selectively connects the antenna 17 to the transmission unit 13 or the reception unit 14 based on the transmission / reception switching signal input from the terminal control unit 11.
In addition, a GPS device 20, on-vehicle radar devices 22 and 24, and an application processing device 200 are connected to the on-vehicle terminal device 10 described above. The GPS device 20 includes a GPS antenna and a calculation unit that analyzes radio waves of satellites received by the GPS antenna, and outputs the position (longitude, latitude) of the vehicle on which the in-vehicle device 100 is mounted.
[0021]
One on-vehicle radar device 22 is installed in the front part of the host vehicle, and transmits a radio wave having a predetermined wavelength in front of the vehicle and detects the reflected wave, thereby detecting a predetermined detection set in front of the vehicle. Detect the presence or absence of vehicles entering and leaving the range.
FIG. 3 is an explanatory diagram of the detection range of the in-vehicle radar device 22. As shown in FIG. 3, the in-vehicle radar device 22 installed in the front part of the host vehicle detects another vehicle that is traveling within a predetermined distance L1 in front of the vehicle. Further, by setting the radio wave transmission width to be narrow and setting the maximum detection width W1 to be approximately the same as the width of the traveling lane, it is possible to detect only the vehicle traveling in the same lane as the host vehicle. By using this in-vehicle radar device 22, (1) the presence or absence of other vehicles that have entered the front of the host vehicle from the intersection road or side road, and the presence or absence of the vehicle that has left the intersection road or side road from the traveling lane, (2 ) It is possible to know the presence or absence of a vehicle that has approached the inside from the outside beyond the detectable distance L1 and the presence or absence of a vehicle that has moved away.
[0022]
The other in-vehicle radar device 24 is installed at the rear of the host vehicle, and transmits a radio wave having a predetermined wavelength to the rear of the vehicle and detects a reflected wave thereof, thereby detecting a predetermined set at the rear of the vehicle. Detects the presence or absence of vehicles entering or leaving the detection range.
FIG. 4 is an explanatory diagram of the detection range of the in-vehicle radar device 24. As shown in FIG. 4, the in-vehicle radar device 24 installed at the rear of the host vehicle detects another vehicle that is traveling within a predetermined distance L2 behind the vehicle. Further, by setting the radio wave transmission width to be narrow and setting the maximum detection width W2 to be approximately the same as the width of the traveling lane, it is possible to detect only the vehicle traveling in the same lane as the host vehicle. By using this in-vehicle radar device 24, (1) the presence or absence of other vehicles that have entered the back of the vehicle from the intersection road or side road, and the presence or absence of the vehicle that has left the intersection road or side road from the traveling lane, (2 ) It is possible to know the presence or absence of a vehicle that has approached the inside from the outside beyond the detectable distance L2 and the presence or absence of a vehicle that has moved away.
[0023]
The application processing device 200 outputs a message to be transmitted to the in-vehicle terminal device 10 or receives a message extracted from the received communication data and performs a predetermined process. For example, the application processing device 200 is configured by a navigation device, an in-vehicle computer, and the like.
[0024]
The in-vehicle device 100 mounted on the vehicle of interest (vehicle A in the example shown in FIG. 2) corresponds to the transmission-source in-vehicle device, and the in-vehicle terminal device 10 mounted in the surrounding vehicle corresponds to the relay terminal device. The memory 12 corresponds to the route information storage means, the in-vehicle radar devices 22 and 24 correspond to the vehicle detection means, and the terminal control unit 11 corresponds to the route information update means and the additional update determination means.
[0025]
The in-vehicle device 100 installed in each vehicle of the inter-vehicle communication network system of the present embodiment has such a configuration, and next, an update operation of the routing table 30 performed in the in-vehicle terminal device 10 of each vehicle will be described. To do.
FIG. 5 is a flowchart showing an operation procedure for updating the contents of the routing table 30 in the in-vehicle terminal device 10 mounted on the vehicle of interest.
[0026]
For example, in the in-vehicle terminal device 10 mounted on the vehicle A shown in FIG. 2, the terminal control unit 11 detects a vehicle that has newly entered and exited beyond these detection ranges based on the detection results of the in-vehicle radar devices 22 and 24. It is determined whether or not it has been detected (step 100). If not detected, a negative determination is made, and then the terminal control unit 11 determines whether or not a predetermined time has passed in an undetected state (step 101). This determination can be made by starting a timer (not shown) when the vehicle is detected last time and checking for the presence of a time-up signal that is output after a predetermined time has elapsed. If the predetermined time has not elapsed, a negative determination is made in the determination of step 101, and the process returns to step 100 to repeat the determination of the presence or absence of vehicle detection.
[0027]
If another vehicle approaches and is detected before and after the vehicle A and is detected by the on-vehicle radar devices 22 and 24, an affirmative determination is made in the determination of step 100. Alternatively, an affirmative determination is made in the determination in step 101 when a state in which no vehicle is detected elapses for a predetermined time. In these cases, the terminal control unit 11 transmits communication data including a predetermined confirmation message to the surrounding vehicles B1 to B4 that are traveling within the communication range (step 102), and then corresponds to this communication data. Then, communication data including a response message sent back from the surrounding vehicles B1 to B4 is received (step 103).
[0028]
In the example shown in FIG. 2, the vehicles B1 to B4 exist in the communicable range of the in-vehicle terminal device 10 mounted on the vehicle A, but at the time of transmitting communication data including a confirmation message, the in-vehicle terminal of the vehicle A Since the device 10 does not accurately grasp these vehicles, the communication data including the confirmation message is transmitted to all vehicles traveling within the communicable range by broadcast distribution.
[0029]
FIG. 6 is a diagram showing a format of communication data transmitted / received between the vehicles. As shown in FIG. 6, the communication data used in this embodiment includes a “header portion” and a “data portion” composed of “transmission destination address” and “transmission source address”.
[0030]
The “transmission destination address” stores an identification number that is mounted on the vehicle at the transmission destination when communication data is transmitted and received between the two vehicles and is given to the in-vehicle terminal device 10. Further, the “transmission source address” is given the identification number given to the in-vehicle terminal device 10 mounted on the transmission source vehicle when communication data is transmitted and received between the two vehicles. The transmission destination address and the transmission source address described above are used to identify one in-vehicle terminal device 10, but need not necessarily be the identification number of the in-vehicle terminal device 10, and may be information unique to each vehicle (for example, Vehicle number) and other unique information may be used. When communication data is transmitted by broadcast distribution to surrounding vehicles such as the vehicle A, a specific value indicating the broadcast distribution is stored in the “destination address” described above.
[0031]
Further, in the “data portion”, for the vehicle terminal device 10 of the vehicle (request vehicle) that is the transmission destination of this communication data, together with the identification number of the vehicle terminal device 10 of the request vehicle and the position of this request vehicle, A confirmation message for requesting the return of similar information (identification number, vehicle position) about other vehicles traveling within the communicable range of the requested vehicle is included.
[0032]
The vehicle-mounted terminal device 10 of each vehicle that has received this confirmation message creates a response message including the requested information and stores it in the data part, and also sets the identification number of the vehicle-mounted terminal device 10 of the vehicle A as the transmission destination address. Then, communication data in which the identification number of the own device is stored in the transmission source address is created and transmitted to the vehicle A.
[0033]
When the communication data including the response message is received from each surrounding vehicle, the terminal control unit 11 of the vehicle A next extracts the response message included in the received communication data, and based on the content of the routing table 30 The contents of the routing information are updated (step 104).
[0034]
As described above, in the inter-vehicle communication network according to the present embodiment, the contents of the routing information are updated when the in-vehicle radar devices 22 and 24 are used to detect the entry / exit of other vehicles with respect to the detection surroundings of the own vehicle. It is not necessary to update the contents of the routing information at predetermined intervals, the amount of communication data transmitted and received between vehicles can be reduced, and the communication band can be used effectively. In particular, when the in-vehicle radar devices 22 and 24 detect the entry and exit of a surrounding vehicle, this means that the configuration of another vehicle that relays communication data has changed, and the content of routing information is updated at this detection timing. By performing this, it is possible to reliably reflect the change of the relay route in the routing information.
[0035]
In addition, the terminal control unit 11 updates the contents of the routing information by inquiring the in-vehicle terminal device 10 of each vehicle capable of direct communication about the state of other vehicles that are not directly communicable. Routing information in a wider range than is possible can be obtained.
[0036]
In addition, when a predetermined time elapses when the on-vehicle radar devices 22 and 24 do not detect the entry or exit of another vehicle, the routing information is updated, so that the vehicle can be detected directly. Even if the other surrounding vehicles change, the contents of the routing information can be updated. In addition, since the time interval at this time is set to be relatively long, it is considered that there is not so much inconvenience (usually because the contents of the routing information are updated at the detection timing of the vehicle), the communication amount is greatly increased. Without any problem, the communication band can be effectively used.
[0037]
Further, by using the on-vehicle radar devices 22 and 24 installed before and after the own vehicle, it becomes possible to detect other vehicles before and after the own vehicle with high accuracy and in a short time, and perform complicated post-processing. The processing load can be reduced by detecting the vehicle without any trouble.
[0038]
Further, by detecting other vehicles traveling in the same direction as the own vehicle by the on-vehicle radar devices 22 and 24, further reducing the amount of vehicles to be detected and effectively using the communication band. Can be achieved. In particular, a vehicle traveling in a different direction from the host vehicle is often excluded from the detection target because the distance from the host vehicle increases and the vehicle is often out of the communicable range of the host vehicle. Even so, it is considered that there is no problem in updating the contents of effective routing information.
[0039]
In addition, this invention is not limited to the said embodiment, A various deformation | transformation implementation is possible within the range of the summary of this invention. In the above-described embodiment, the in-vehicle radar devices 22 and 24 are installed in front of and behind the vehicle. However, the in-vehicle radar device can be set to only one of them, or one or a plurality of in-vehicle radar devices having no directivity in detection direction can be installed. Other vehicles in the vicinity may be detected.
[0040]
In the embodiment described above, another vehicle traveling in the same lane as the vehicle of interest is detected. However, when the range where direct communication is possible is wide, the vehicle is traveling in the opposite lane or another adjacent lane. Since it is possible to relay communication data using the in-vehicle terminal device 10 mounted on the vehicle, the detection range of the on-vehicle radar devices 22 and 24 may be expanded so that these vehicles can also be detected. .
[0041]
In the above-described embodiment, the in-vehicle radar devices 22 and 24 are used to detect surrounding vehicles, but the vehicle may be detected using other methods. For example, the surroundings may be photographed with a camera, and the photographed image may be analyzed to detect that surrounding vehicles have entered or exited a predetermined range.
[0042]
Further, in the above-described embodiment, the information about the surrounding vehicles from the target vehicle to the second stage ahead is acquired and the contents of the routing information are updated. However, the contents of the routing information are updated for the vehicles up to what stage. This can be changed as appropriate. For example, when only the information related to the first-stage vehicle in the range that can be directly communicated is acquired to update the contents of the routing information, or the information about the surrounding vehicles up to the third stage or more is acquired and the contents of the routing information It is possible to update.
[0043]
Further, in the above-described embodiment, the case where the content of the routing information is updated while paying attention to the vehicle A has been described. However, the content of the routing information having the same content is also updated in parallel for each of the other vehicles.
[0044]
【The invention's effect】
As described above, according to the present invention, the content of the route information is updated when the entry / exit of the surrounding vehicle is detected, and it is not necessary to update the content of the route information at a short predetermined interval. The amount of communication data transmitted can be reduced, and the communication band can be used effectively.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of an in-vehicle device mounted on each vehicle constituting an inter-vehicle communication system according to an embodiment.
FIG. 2 is a diagram showing an outline of a routing table included in an in-vehicle terminal device mounted on each vehicle.
FIG. 3 is an explanatory diagram of a detection range of the in-vehicle radar device.
FIG. 4 is an explanatory diagram of a detection range of the in-vehicle radar device.
FIG. 5 is a flowchart showing an operation procedure for updating the contents of a routing table in an in-vehicle terminal device mounted on a vehicle of interest.
FIG. 6 is a diagram showing a format of communication data transmitted / received between the vehicles.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 In-vehicle terminal device 11 Terminal control part 12 Memory 13 Transmission part 14 Reception part 15 Antenna switching part 20 GPS apparatus 22, 24 In-vehicle radar apparatus 30 Routing table 200 Application processing apparatus

Claims (5)

A vehicle-to-vehicle communication system that relays communication data transmitted from a transmission source vehicle-mounted device by a relay terminal device mounted on another vehicle traveling around the vehicle on which the transmission source vehicle-mounted device is mounted,
The transmission in-vehicle device is
Route information storage means for storing route information related to the relay route via the relay terminal device;
Vehicle detection means for detecting a surrounding vehicle that enters and exits beyond a detection range that is set to the same extent as a range in which the transmission in-vehicle device can communicate directly without using the relay terminal device ;
Route information update means for updating the contents of the route information stored in the route information storage means when the vehicle detection means detects the entry / exit of a surrounding vehicle ;
A vehicle-to-vehicle communication system comprising: In claim 1,
The route information update means updates the content of the route information by inquiring of the status of the other relay terminal device that is not directly communicable to the relay terminal device that is capable of direct communication. Inter-vehicle communication system. In claim 1 or 2,
The elapsed time after the update of the content of the route information by the route information update unit is measured, and an update instruction is issued when a predetermined time has passed without the surrounding vehicle being detected by the vehicle detection unit being detected. Is further provided with additional update determination means for outputting
The inter-vehicle communication system according to claim 1, wherein the route information update unit updates the content of the route information when the update instruction is output from the additional update determination unit. In any one of Claims 1-3,
The inter-vehicle communication system characterized in that the vehicle detection means is an on-vehicle radar device that is set before and after the own vehicle and detects other vehicles traveling in front and behind the own vehicle. In claim 4,
The inter-vehicle communication system characterized in that the vehicle detection means detects another vehicle traveling in the same direction as the own vehicle.

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