JP2004140477A - Inter-vehicle network system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inter-vehicle network system capable of decreasing the facility and communication costs. <P>SOLUTION: The inter-vehicle network system is formed such that vehicle servers 100 to 120 are interconnected and a vehicle client 200 is connected to any of the vehicle servers. A vehicle client 240 desiring connection to the inter-vehicle network system accesses an address check server 500 to receive the address list of the vehicle servers 100 to 120 located in the vicinity of the vehicle client 240. The vehicle client 240 then establishes connection to the connectable vehicle server 120 on the basis of the address list. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an inter-vehicle network system for mutually connecting terminal devices mounted on a vehicle.
[0002]
[Prior art]
Recently, with the spread of mobile communication means such as a mobile phone, it has become possible to perform communication between vehicles using a navigation device or other in-vehicle computer. For example, a common management database manages information about each wireless terminal, and when performing communication between wireless terminals, a communication that accesses this management database from one wireless terminal to obtain information on a wireless terminal that is a communication partner. A system is known (for example, see Patent Document 1).
[0003]
[Patent Document 1]
JP 2001-112043 A (pages 2-5, FIG. 1-6)
[0004]
[Problems to be solved by the invention]
By the way, in the communication system disclosed in Patent Document 1 described above, communication is performed between a plurality of base stations whose installation locations are fixed and a wireless terminal. Therefore, in order to expand the communicable range of the wireless terminal, it is necessary to construct a base station in accordance with the increase, and there is a problem that construction of a communication system is costly.
[0005]
Patent Document 1 described above also discloses a communication system using a local wireless network that is accidentally formed by a plurality of wireless terminals. However, in this communication system, position information of all terminal devices is used. Are managed by the management database, and when one wireless terminal communicates with another wireless terminal, it is necessary to always make an inquiry to the management database, so that each wireless terminal frequently accesses the management database. Then, when the system is applied to a system such as a vehicle-to-vehicle network, there is a problem that a communication cost is required. For example, considering a case where a wireless terminal is mounted on a vehicle and a management database is installed at a predetermined place on the ground, it is convenient to use a mobile phone for inquiries from the wireless terminal to the management database in consideration of a communication range at present. It is. However, since the communication fee of the mobile phone is expensive, if the inquiry is frequently made, the communication fee is increased accordingly.
[0006]
The present invention has been made in view of such a point, and an object of the present invention is to provide an inter-vehicle network system capable of reducing equipment costs and communication costs.
[0007]
[Means for Solving the Problems]
In order to solve the above-described problem, an inter-vehicle network system according to the present invention includes a plurality of vehicle servers interconnected by a first wireless communication unit, and a second wireless communication with one of the plurality of vehicle servers. In response to an address transmission request from a car client connected by the means and a car client not connected to the car server, address information for specifying a car server existing around the car client is searched, and the search result is obtained. An address check server for transmitting the address transmission request to the car client. By connecting a car client to one of a plurality of mutually connected car servers, communication between the car clients becomes possible, and there is no need to install a base station connected to the car client, which reduces equipment costs. It becomes possible to reduce. Further, since the connection from the car client to the address check server only needs to be performed once at the time of the address transmission request, the communication cost required for this connection can be reduced.
[0008]
The address check server described above includes a car server monitoring unit that monitors an operation state of the car server at predetermined time intervals, and a car server that is confirmed by the car server monitoring unit to be communicable with the car client. It is desirable to have a car server search means for searching for address information for a target, and a search result transmitting means for transmitting the address information searched by the car server search means to a car client that is an address transmission request source. This makes it possible to always grasp the operating state of the car server and search for a car server to which the car client can reliably connect.
[0009]
Further, it is preferable that the car server search means selects a predetermined number of car servers from among a plurality of car servers existing around the address transmission request source when the number of car servers is larger than the predetermined number. Thereby, the connection between the car client and the car server can be more reliably realized.
[0010]
In addition, the above-described address check server further includes a statistical information management unit that manages a statistical operation time for each of a plurality of time zones for each of the car servers, and the car server search unit performs a search for the address information. It is desirable to select a predetermined number of car servers in consideration of the statistical operation time corresponding to the time zone including the time to be performed. As a result, it is possible to reduce the chances of selecting a car server that is likely to end its operating state despite being connected to a car client.
[0011]
In addition, it is desirable that the above-mentioned car client and car server and the address check server be connected only while transmitting and receiving information. This makes it possible to reliably reduce the communication cost.
Further, it is desirable that the above-described car server is provided corresponding to a commercial vehicle. This makes it possible to realize a car server that is expected to continue operating for a relatively long time, thereby facilitating the maintenance of an inter-vehicle network.
[0012]
Further, the above-mentioned car server performs statistical processing of the connection state of the car client connected by the second wireless communication means and transmits this statistical data to the address check server, and the address check server transmits the statistical data from the car server. It is desirable to keep the statistical data that comes in. In particular, it is desirable that the address check server treats a car client whose connection state with the car server satisfies a predetermined criterion as a car server based on the statistical data. By statistically processing the connection status such as the time during which the car client is connected to the car server, it is possible to know the operating time of this car client, and operate the car client with the long operating time as the car server By doing so, it is possible to expand the vehicle-to-vehicle network without increasing equipment costs.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an inter-vehicle network system according to an embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a diagram schematically illustrating an inter-vehicle network system according to an embodiment. As shown in FIG. 1, an inter-vehicle network system according to the present embodiment includes one or more (three in FIG. 1) car servers 100, 110, and 120 connected to each other by using a predetermined communication unit. Management of one or more (four in FIG. 1) car clients 200, 210, 220, 230 interconnected with any one of the vehicle servers 100 to 120 and address information specifying each of the car servers 100 to 120. And the like.
[0014]
Each of the car clients 200 to 230 is a terminal device that is a transmission source or a transmission destination of various types of information transmitted and received via the inter-vehicle network. The car servers 100 to 120 are terminal devices that relay when transmitting and receiving information between car clients. For example, each of the car servers 100 to 120 is provided corresponding to a business vehicle such as a bus or a taxi. Each of the car servers 100 to 120 and the car clients 200 to 230 is realized by using an in-vehicle terminal device (described later) mounted on a moving vehicle. The address check server 500 is realized by a computer installed in a predetermined building.
[0015]
In the inter-vehicle network of the present embodiment, information can be transmitted and received between a plurality of car clients connected to one car server or a plurality of car clients connected to each of a plurality of car servers connected to each other. Will be possible. When transmitting and receiving information between a plurality of car clients connected to one car server, the information is relayed by the one car server. When transmitting and receiving information between a plurality of car clients connected to each of a plurality of car servers connected to each other, the information is relayed by each of the plurality of car servers connected to each other. .
[0016]
Also, in the present embodiment, the positional relationship between the car servers 100 to 120 and the car clients 200 to 230 changes as the vehicle on which they are mounted moves from moment to moment, so this positional relationship is always grasped. Therefore, the address check server 500 is used for this purpose.
[0017]
FIG. 2 is a diagram showing a detailed configuration of the car server 100. As shown in FIG. 2, the car server 100 is configured to include an in-vehicle terminal device 10, a GPS device 20, and a mobile phone 30 mounted on a vehicle. The other car servers 110 and 120 and the car clients 200 to 230 have basically the same configuration.
[0018]
The in-vehicle terminal device 10 transmits and receives various 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, an antenna switching unit 15, and a communication processing unit 16.
[0019]
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. The memory 12 stores address information for specifying the car server 100 in addition to the operation program executed by the on-board terminal device 11. For example, a unique ID assigned to the in-vehicle terminal device 10 is used as address information for identifying the car server 100.
[0020]
The transmitting unit 13 performs a process of transmitting a transmission signal output from the terminal control unit 11 to another vehicle from the antenna 17 via the antenna switching unit 15. In addition, the receiving unit 14 performs a process of receiving a reception signal transmitted from another vehicle and reaching the antenna 17 via the antenna switching unit 15. 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.
[0021]
The communication processing unit 16 performs a process of transmitting and receiving various types of information between the car server 100 and the address check server 500 using the mobile phone 30. The communication using the mobile phone 30 is performed only when a request for transmitting and receiving information occurs.
Further, a GPS device 20 is connected to the above-mentioned in-vehicle terminal device 10. The GPS device 20 includes a GPS antenna and a calculation unit that analyzes a satellite radio wave received by the GPS antenna, and outputs the position (longitude and latitude) of the vehicle on which the vehicle server 100 is mounted.
[0022]
FIG. 3 is a diagram showing a detailed configuration of the address check server 500. As shown in FIG. 3, the address check server 500 includes a server control unit 510, an address DB (database) 520, a statistical information DB 530, and a communication processing unit 540. The server control unit 510 monitors the operating states of the car servers 100 to 120 and performs processing of searching for and answering a car server located around the car client when requested by the car client, A vehicle server monitoring unit 512, a vehicle server search unit 514, and a statistical information updating unit 516 are provided. The server control unit 510 has a configuration as a computer including a CPU, a ROM, a RAM, and the like, and performs a predetermined control operation by executing a predetermined program stored in the ROM or the RAM.
[0023]
The car server monitoring unit 512 performs an operation of monitoring the operating state of each of the registered car servers 100 to 120 at a predetermined time interval, that is, an operation of detecting whether each car server is operating. The car server search unit 514 performs a process of searching for a car server located around the car client (when the position information of the car client is sent together with the request) when requested by the car client. The statistical information updating unit 516 performs a process of updating statistical information indicating the operation state of each of the car servers 100 to 120.
[0024]
The address DB 520 stores information necessary for searching for address information of a car server located around each car client. For example, the address DB 520 stores at least address information and position information corresponding to each car server.
[0025]
In addition, the statistical information DB 530 stores statistical information indicating the operating state of each vehicle server. For example, as statistical information for each vehicle server, four time zones from 0:00 am to 6:00, 6:00 am to 0:00 pm, 0:00 pm to 6:00 pm, and 6:00 pm to 0:00 am The average value of the operating time of each car server is stored in the statistical information DB 530.
[0026]
The above-described car server monitoring unit 512 corresponds to a car server monitoring unit, the car server searching unit 514 corresponds to a car server searching unit, a search result transmitting unit, and the statistical information updating unit 516 corresponds to a statistical information managing unit.
The inter-vehicle network according to the present embodiment has such a configuration, and next, an operation required for the car clients to transmit and receive information using the inter-vehicle network will be described.
(1) The address check server 500 monitors the operation status and the current position of all the car servers. Further, the address check server 500 updates the statistical information corresponding to each car server.
(2) The car client sends a request for transmission of address information specifying a nearby car server to the address check server 500, and the car client specified by the address information sent from the address check server 500 Establish a connection between
[0027]
Hereinafter, the operation (1) of the above-described address check server 500 and the operation (2) of the car client will be described in detail.
(1) Operation of address check server
FIG. 4 is a flowchart showing an operation procedure in which the address check server 500 monitors the operation state of each car server.
[0028]
The car server monitoring unit 512 in the server control unit 510 determines whether a predetermined time (for example, 10 minutes) has elapsed from the previous monitoring operation (Step 100), and if not, a negative determination is made. And repeat this determination. Further, when a predetermined time has elapsed, an affirmative determination is made, and then the car server monitoring unit 512 inquires of one car server whether connection is possible (step 101) and then determines whether there is a response. (Step 102). If the inquiry server is in operation and a response is returned to the inquiry, an affirmative determination is made. Next, the automobile server monitoring unit 512 determines that connection is possible, and Is created (step 103). On the other hand, if the car server that is the inquiry destination is not operating and does not return a response to the inquiry, a negative determination is made in the determination of step 102, and then the car server monitoring unit 512 It is determined to be impossible, and car server information corresponding to this car server is created (step 104). The car server information includes at least address information of the car server, position information (longitude, latitude) of the car server, and information indicating whether connection is possible. The car server information is stored in the address DB 520.
[0029]
Next, the statistical information updating unit 516 updates the statistical information stored in the statistical information DB 530 based on the created car server information (Step 105). As described above, the statistical information stored in the statistical information DB 530 includes the address of each car server and the average operating time for each time zone, and indicates the time (10 seconds) from the previous monitoring operation to the current monitoring operation. A process is performed to reflect the operating state of (minute) on the statistical information. For example, when the number of days from the start of monitoring of this car server to the present time is D, and the average operating time in the time zone including the current time is H (minutes), this car server performs this monitoring operation. If it is in operation, it is determined that it has been in operation for 10 minutes, and an update process of adding 10 / D to the average operation time H up to that time is performed. On the other hand, if the car server is not in operation in this monitoring operation, it is determined that the car server has been in the non-operation state for 10 minutes, and an update process of subtracting 10 / D from the average operation time H so far is performed. .
[0030]
Next, the car server monitoring unit 512 determines whether or not the inquiry has been completed for all the car servers (Step 106). If there is a car server that has not made an inquiry, a negative determination is made, the process returns to step 101, and the processing after the inquiry to another car server is repeated. If the inquiry to all the car servers 100 to 120 has been completed, an affirmative determination is made in the determination of step 106, and the process returns to step 100 and the processing after the determination of the elapse of the predetermined time is repeated.
[0031]
Dotted lines extending from the address check server 500 to the three car servers 100 to 120 shown in FIG. 1 indicate the outline of the inquiry operation in step 101 performed by the address check server 500. First, an inquiry is made to the car server 100 (1), then an inquiry is made to the car server 110 (2), and finally, an inquiry is made to the car server 120 (3). . In this way, the operation states of all the car servers 100 to 120 are monitored.
[0032]
(2) Car client operation
FIG. 5 is a flowchart showing an operation procedure until a connection is established between a car client and a nearby car server. It is assumed that a connection is established in, for example, a new car client 240, and the description will be made assuming that the car client 240 has the same configuration as the car server 100 shown in FIG.
[0033]
First, the terminal control unit 11 in the car client 240 transmits an address list of a predetermined number of car servers located around the own vehicle from the mobile phone 30 to the address check server 500 via the communication processing unit 16. Request (step 200). When the request for transmitting the address list ends, the terminal control unit 11 determines whether or not the address list transmitted in response to the request has been received (step 201). If not received, a negative determination is made and this determination is repeated.
[0034]
In the address check server 500, a predetermined number (for example, five) of car servers located around the car client 240 which is the transmission request source of the address list is searched by the car server search unit 514 in the server control unit 510, The address list of these car servers is sent back to the client 240. In addition, when searching for a predetermined number of car servers, the car server search unit 514 extracts the car servers in order from the one closest to the car client 240, and based on the statistical information stored in the statistical information DB 530. The vehicle server may be extracted in the order in which the average value of the operation time corresponding to the time zone including the time is large, that is, the operation time is long. In the example shown in FIG. 1, since there are only three car servers 100 to 120 around the car client 240, an address list of up to three (when all are in operation) car servers 100 to 120 is created. Is done.
[0035]
In this way, when the address list is created by the car server search unit 514 and sent back to the car client 240, the terminal control unit 11 in the car client 240 makes an affirmative decision in the determination of step 201, and based on the address list. A connection is requested from one car server (step 202). Next, the terminal control unit 11 determines whether or not a connection has been established (step 203). If the connection has not been established, a negative determination is made, and the process returns to step 202 and returns to the next car server. The processing after the connection request is performed. If the connection has been established, an affirmative determination is made in the determination at step 203, and a series of processes relating to the connection establishment between the car client 240 and any of the car servers ends.
[0036]
FIG. 6 is a diagram showing an outline of establishing a connection between the car client 240 and the car server. First, the car client 240 requests the address check server 500 to transmit the address list of the car server, and the address list is sent from the address check server 500 to the car client 240 in response to this request. The car client 240 and the address check server 500 are connected only while these pieces of information are transmitted and received.
[0037]
Next, the car client 240 makes a connection request (1) to the car server having the highest rank in the received address list, for example, the car server 110. If for some reason there is no response from the car server 110 and the connection is not established, the car client 240 sends a connection request to the car server with the next highest rank in the address list, for example, the car server 120. Perform (2). When the connection permission is sent from the car server 120 to the car client 240, the connection is established. Thereafter, the car client 240 is connected via the car server 120 to the car clients 220 and 230 connected to the car server 120 and the car clients 200 and 210 connected via the network between the car servers. It is possible to transmit and receive information to and from.
[0038]
When the car client 240 wants to disconnect the connection established with the car server, the car client 240 may transmit its own address information to the car server and then disconnect.
(3) Other operations
When the inactive car server joins the inter-vehicle network, it is necessary to find another car server that can communicate with each other and establish a connection with this car server. The search for the car server and the establishment of the connection are basically the same as the operation of the car client 240 searching for a nearby car server and establishing the connection. Therefore, such a car server can participate in the inter-vehicle network by establishing a connection with another nearby car server by performing an operation according to the operation procedure shown in FIG.
[0039]
When a car server participating in the inter-vehicle network receives a new connection request from a car client and sends a notice of connection permission to the car client, the car server adds the connection request to the list of car clients connected to the car server. Add the address information of the newly established car client. Conversely, when the car server receives the disconnection notification from the car client connected to the car server, the car server deletes the address information of the car client from the list of car clients connected to the car server.
[0040]
When the car server participating in the inter-vehicle network disconnects the connection with the inter-vehicle network, the car server sends a disconnection request and an address list of other car servers to all car clients connected to the car server. At the same time, it transmits a disconnection request and its own address information to another connected car server. After that, when the disconnection completion notification is received from all the car clients, the connection with another car server is disconnected. The other car server deletes the address information of the car server to which the disconnection request has been sent. Also, the car client receiving the disconnection request from the car server attempts to establish a connection to another car server included in the address list sent at that time, and at the stage when the connection is established, the own client address. The information is transmitted to the car server with which the connection has been established, and a notice of disconnection completion is sent to the original car server.
[0041]
As described above, by connecting the car client to any of the plurality of car servers connected to each other, communication between the car clients becomes possible, so that there is no need to install a base station connected to the car client. This makes it possible to reduce equipment costs. Further, since the connection from the car client to the address check server only needs to be performed once at the time of the address transmission request, the communication cost required for this connection can be reduced.
[0042]
In addition, in a building town or a mountainous area, it is often difficult to make a conventional connection using a mobile phone or the like. In particular, since a vehicle moves, in a conventional communication using a mobile phone or the like, if the vehicle enters such an area during the connection, the network connection is often cut off. Even in the case of entering such an area, the connection is not interrupted by using the inter-vehicle network system of the present embodiment, once the inter-vehicle network is constructed.
[0043]
Note that the present invention is not limited to the above embodiment, and various modifications can be made within the scope of the present invention. For example, in the above-described embodiment, a case has been described in which the car server is provided corresponding to a commercial vehicle. However, the car server may be provided corresponding to a non-business vehicle such as a private vehicle.
[0044]
Further, a car client having a long operating state may be operated as a car server. Specifically, each of the car servers 100 to 120 performs statistical processing of the connection state of the car client 200 and the like connected to the own server, and temporarily stores the resulting statistical data at an appropriate timing. The information is transmitted to the address check server 500 (for example, at the next timing when some information other than the statistical data is transmitted and received to and from the address check server 500). The server control unit 510 in the address check server 500 stores and holds the statistical data sent from the vehicle server 100 or the like in the statistical information DB 530, and connects to the vehicle server 100 or the like based on the statistical data. A car client whose status satisfies a predetermined criterion (for example, a day's connection time is equal to or longer than a predetermined time) is upgraded to a car server, and information on the newly upgraded car server is stored in the address DB 520. As a result, a car client that actually has a long operating time can be treated as a car server, so that it is possible to expand a car-to-car network without increasing equipment costs.
[0045]
【The invention's effect】
As described above, according to the present invention, by connecting a car client to any one of a plurality of mutually connected car servers, communication between the car clients becomes possible. There is no need to set up a station, and equipment costs can be reduced. Further, since the connection from the car client to the address check server only needs to be performed once at the time of the address transmission request, the communication cost required for this connection can be reduced.
[Brief description of the drawings]
FIG. 1 is a diagram schematically illustrating an inter-vehicle network system according to an embodiment.
FIG. 2 is a diagram showing a detailed configuration of a car server.
FIG. 3 is a diagram showing a detailed configuration of an address check server.
FIG. 4 is a flowchart showing an operation procedure in which an address check server monitors an operation state of each car server.
FIG. 5 is a flowchart showing an operation procedure until a connection is established between a car client and a nearby car server.
FIG. 6 is a diagram showing an outline of establishing a connection between a car client and a car server.
[Explanation of symbols]
10 In-vehicle terminal device
11 Terminal control unit
12 memory
13 Transmitter
14 Receiver
15 antenna switching unit
16,540 Communication processing unit
17 antenna
20 GPS device
30 mobile phone
100, 110, 120 car server
200, 210, 220, 230, 240 car clients
500 @ address check server
510 Server control unit
512 Car server monitoring unit
514 Car server search section
516 Statistical information update section
520 @ address DB
530 Statistics information DB

Claims (8)

A plurality of car servers interconnected by a first wireless communication means;
A car client connected to any of the plurality of car servers by a second wireless communication unit;
In response to an address transmission request from the car client not connected to the car server, address information for identifying the car server existing around the car client is searched, and the search result is used as an address transmission request source. An address check server for transmitting to the car client;
A vehicle-to-vehicle network system comprising: In claim 1,
The address check server,
Car server monitoring means for monitoring the operation state of the car server at predetermined time intervals,
A car server search unit that searches the address information for the car server that is confirmed by the car server monitoring unit to be in a state capable of communicating with the car client;
A search result transmitting unit that transmits the address information searched by the car server searching unit to the car client that is the address transmission request source;
A vehicle-to-vehicle network system comprising: In claim 1 or 2,
The vehicle-to-vehicle network, wherein the vehicle server search means selects the predetermined number of the vehicle servers from among the vehicle servers existing around the address transmission request source when the number of the vehicle servers is larger than a predetermined number. system. In claim 3,
The address check server further includes, for each of the car servers, statistical information management means for managing a statistical operation time for each of a plurality of time zones,
The car server search means selects the predetermined number of the car servers in consideration of a statistical operation time corresponding to the time zone including a time at which the address information is searched. Vehicle-to-vehicle network system. In any one of claims 1 to 4,
The vehicle-to-vehicle network system is connected between the vehicle client and the vehicle server and the address check server only while transmitting and receiving information. In any one of claims 1 to 5,
An inter-vehicle network system, wherein the car server is provided corresponding to a commercial vehicle. In any one of claims 1 to 5,
The car server performs statistical processing of the connection state of the car client connected by the second wireless communication unit, and transmits the statistical data to the address check server,
The inter-vehicle network system, wherein the address check server holds the statistical data sent from the car server. In claim 7,
The inter-vehicle network system, wherein the address check server treats, as the car server, the car client whose connection state with the car server satisfies a predetermined criterion based on the statistical data.

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