JP2004289377A - Method and device for inter-vehicle communications - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent from receiving the same message twice or more and to prevent from distributing the same message twice or more in the inter-vehicle communications. <P>SOLUTION: The inter-vehicle communication device, which prepares a message and transmits it first, adds identification information to the message and transmits it. A double transmission/reception determining part (92) of the inter-vehicle communication device receiving the message checks whether the identification information of the message is preserved in a built-in memory (83). When it is preserved, the message is discarded. When it is not preserved, a message reception part (82) processes the message without discarding it, it preserves the identification information of the message in the memory (83), and at the same time, it transmits the message. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a vehicle-to-vehicle communication method and a vehicle-to-vehicle communication device, and more particularly to a vehicle-to-vehicle communication method and a vehicle-to-vehicle communication device that can prevent the same message from being received repeatedly.
[0002]
[Prior art]
In an existing network, information is transmitted and received by specifying a partner by an IP address. The same applies to a wireless LAN, in which data transmission / reception is performed after specifying each other's address.
By the way, with the development of communication technology, communication between mobile bodies such as between vehicles (vehicle-to-vehicle communication) has become possible. In such inter-vehicle communication, information is transmitted without specifying the other party, and the receiving vehicle receives and displays the information as appropriate and transmits the received information to another vehicle. This makes it possible to expand the communication range even in the case of inter-vehicle communication having a limited communication distance.
[0003]
7 and 8 are explanatory diagrams of a conventional inter-vehicle communication method.
{Circle around (1)} In FIG. 1 and send the information.
(2) Vehicles 2 and 3 receive the message No. from vehicle 1. Obtain 1 directly and send the information to other vehicles. In advance, the vehicle 2 generates a message No. created by its own. 2 and the vehicle 3 have their own message No. 3 respectively, the message No. The message to be transmitted by the vehicle 2 and the vehicle 3 at the time of reception is Vehicle 2: Message No. 1 + Message No. 2
Vehicle 3: Message No. 1 + Message No. 3
It becomes. The vehicle 2 and the vehicle 3 transmit the message.
[0004]
{Circle around (3)} Vehicle 4 was transmitted from vehicle 3 [Message No. 1 + Message No. 3] directly and send information to other vehicles. In advance, the vehicle 4 has a message No. created by itself. 4 is stored, [Message No. 1 + Message No. 3] The message to be transmitted by the vehicle 4 at the time of reception is the message No. 1 + Message No. 3 + Message No. 4
It becomes. The vehicle 4 transmits the message.
{Circle around (4)} Then, the vehicle 5 receives the message No. 1 + Message No. 3 + Message No. 4] directly and send information to other vehicles. In advance, the vehicle 5 has a message No. created by itself. 5 is stored, [Message No. 1 + Message No. 3 + Message No. 4] The message to be transmitted by the vehicle 5 at the time of reception is the message No. 1 + Message No. 3 + Message No. 4 + Message No. 5
It becomes. The vehicle 5 transmits the message.
[0005]
{Circle around (5)} After a short time, when the vehicle enters the state shown in FIG. 1 + Message No. 2
To another car.
(6) The vehicle 5 directly obtains the information transmitted from the vehicle 2 and transmits the information to another vehicle.
At this time, the vehicle 5 receives and distributes “Message No. 1”, but the vehicle 5 has already received this “Message No. 1” in the state of (4). As a result, the same information may be received twice or more, or the same information may be transmitted twice or more.
That is, in the conventional vehicle-to-vehicle communication that does not specify a partner,
・ Receive the same message more than once,
・ Deliver the same message more than once,
There was a problem. And consequently,
・ Unnecessary transmission volume in vehicle-to-vehicle communication increases,
・ The user's workload increases because the user reads the same message multiple times.
The problem has occurred.
Broadcasting and multicasting are techniques for transmitting information without specifying a partner (for example, see Non-Patent Document 1).
[Non-patent Document 1] Supervised by Haruhisa Ishida, "Internet Textbooks, Volume 1", I & E Shinzo Research Laboratory, June 25, 2000, P119-120
[0006]
[Problems to be solved by the invention]
However, the prior art merely performs multicasting and broadcasting, and the receiving device does not perform multicasting one after another, and cannot solve the above problem.
Accordingly, it is an object of the present invention to prevent the same message from being received more than once and the same message not to be distributed more than once.
[0007]
[Means for Solving the Problems]
In the vehicle-to-vehicle communication device of the present invention, the vehicle-to-vehicle communication device that creates a message and transmits the message first transmits the message with identification information added thereto, and the vehicle-to-vehicle communication device that receives the message transmits the message identification information. Is stored in a built-in memory, if it is stored, the message is discarded, if not stored, the message is processed without being discarded, and the identification information of the message is stored in the memory. , Send the message.
According to the vehicle-to-vehicle communication device and the vehicle-to-vehicle communication method of the present invention, it is possible to prevent the same message from being received more than once or to distribute the same message more than once. As a result, it is possible to suppress an unnecessary increase in the amount of transmission in vehicle-to-vehicle communication, and to prevent the user from reading the same message a plurality of times, thereby reducing the amount of user work.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
(A) Vehicle-to-vehicle communication device FIG. 1 is a configuration diagram of a vehicle-mounted device according to the present invention, in which a navigation device 50 and a vehicle-to-vehicle communication device 60 are communicably provided.
The vehicle-to-vehicle communication device 60 manages communication means (for example, Bluetooth device, wireless LAN means, etc.) 61 for communicating with surrounding vehicles, a vehicle-to-vehicle communication control unit 62 for controlling vehicle-to-vehicle communication, and communication with a navigation device. An interface unit 63, an operation unit 64, various detection units 65, and the like are provided. The storage device 71 of the inter-vehicle communication control unit 62 has a program storage unit 71a and a data storage unit 71b in which various programs and data are stored. Message identification information (referred to as a message key) and a storage time described later are stored in the data storage unit 71b.
[0009]
The navigation device 50 performs map display control around the vehicle, search control for searching for a guidance route to a destination, route guidance control along the searched guidance route, and the like. It has a function to detect time and the like and notify the inter-vehicle communication device 60.
[0010]
Bluetooth used for inter-vehicle communication is a wireless link intended to replace a cable between a mobile object and a fixed object, or between a mobile object and an electronic device of the mobile object, or between them, and transmits data to a TDD (Time-Time) of 625 μs per slot. Packets are transferred by the Division Duplex method, and frequency hopping in which the frequency changes for each packet is adopted. Using the same frequency hopping sequence, one master and up to seven slaves form a network and perform communication. The details of the Bluetooth specification are described in Specification of the Bluetooth System Version 1.0A.
[0011]
(B) Transmission of Unique Message FIG. 2 is a functional configuration diagram of the inter-vehicle communication device 60 for transmitting an independently created message, and FIG. 3 is a flowchart of a uniquely created message transmission process.
If a uniquely created message has not been sent yet (step 101), the message key generator 81 creates a message key to be added to the message (step 102). The message key identifies a uniquely created message. Preferably, (1) the latitude and longitude of the point where the message is transmitted first, (2) the time when the message is transmitted, and (3) the size of the message in order. Create side by side. That is, the message key generation unit 81 acquires the longitude / latitude and the current time of the vehicle from the navigation device 50, calculates the message size (in terms of the number of bytes), and creates a message key including these. As an example, assuming that data of 120 bytes is to be transmitted at 6:35 pm at a latitude of 36 degrees 40 minutes north and 135 degrees 12 minutes east longitude, the message key is N03640E135121183500120.
It becomes.
[0012]
Then, the created message key is added to the head of the message (text) and passed to the message transmitting unit 82 as transmission data (step 103). The message transmitting unit 82 transmits the transmission data without specifying the other party (step 104). After transmitting the data, the message transmitting unit 82 associates the message key of the transmitted data with the current time and stores it in the message DB (message DB) 83 (step 105). Thus, the transmission of the uniquely created message ends.
[0013]
(C) Reception and Transmission of Message FIG. 4 is a functional configuration diagram of the inter-vehicle communication device 60 that receives a message and transmits the received message, and FIG. 5 is a message transmission / reception processing flow.
If the message receiving unit 91 receives a message (step 201), the duplex transmission / reception determining unit 92 extracts a message key from the received message and checks whether the same message key as the message key exists in the message DB 83 (step 201). 202). If there is, the message is discarded (step 203), and the process ends. Here, the discarding process means that neither the message is read nor transmitted.
[0014]
On the other hand, if the message key identical to the message key of the received message does not exist in the message DB 83, the double transmission / reception determination unit 92 takes in the received message and inputs it to the message reception determination unit 93 (step 204). The message reception judging unit 93 judges whether the received message is a message required by the user (step 205), saves the message if necessary, and displays it on the message display unit 94 (step 206). Next, the message reception determination unit 93 inputs [received message + message key] to the message transmission unit 82. As a result, the message transmitting unit 82 transmits [received message + message key] (step 207). Next, or in the case of “NO” in step 205, the message transmitting unit 82 associates the message key of the data with the current time and stores it in the message DB 83 (step 208). Thus, the message transmission / reception processing ends.
[0015]
(D) Message Key Deletion Processing FIG. 6 is a message key deletion processing flow of the message DB 83.
Since the message DB 83 is limited, the message key is deleted from the message DB when a predetermined time elapses after storing the message key and there is no possibility of receiving the same message again. That is, if it is assumed that the message DB 83 performs the message deletion process every hour, it checks that the monitoring time has come every hour (step 301). If the monitoring time has not come, the process returns to the beginning. On the other hand, if the monitoring time has come, it is checked whether there is a message key for which the storage time has passed 24 hours (step 302). If the message exists, the message is deleted (step 303), and the process returns to the beginning and deletes the message thereafter.
[0016]
【The invention's effect】
According to the present invention, the inter-vehicle communication device that creates a message and transmits the message first with identification information added to the message and transmits the message, and the inter-vehicle communication device that receives the message incorporates the identification information of the message. Check whether the message is stored in the memory of the server, if the message is stored, discard the message, otherwise store the message without discarding the message, store the identification information of the message, and transmit the message The same message can be received twice or more, or the same message can be prevented from being distributed more than once. As a result, it is possible to suppress an unnecessary increase in the amount of transmission in vehicle-to-vehicle communication, prevent the user from reading the same message a plurality of times, and reduce the amount of user work.
[0017]
Further, according to the present invention, since the storage time of the identification information is stored and the identification information is deleted when the set time has elapsed, the number of message identification data to be stored can be reduced, and the collation work and the memory can be performed. Capacity can be reduced.
Further, according to the present invention, since the message identification information is composed of the latitude and longitude of the point where the message was first transmitted, the time when the message was transmitted, and the size of the message, it is assumed that exactly the same message identification information appears. Never miss a message you really need, and you can reliably discard already confirmed messages.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a vehicle-mounted device of the present invention.
FIG. 2 is a functional configuration diagram of a vehicle-to-vehicle communication device that transmits a uniquely created message.
FIG. 3 is a flowchart of a message transmission process uniquely created.
FIG. 4 is a functional configuration diagram of an inter-vehicle communication device that receives a message and transmits the received message.
FIG. 5 is a message transmission / reception processing flow.
FIG. 6 is a message key deletion processing flow.
FIG. 7 is an explanatory view (part 1) of a conventional inter-vehicle communication method.
FIG. 8 is an explanatory diagram (part 2) of a conventional inter-vehicle communication method.
[Explanation of symbols]
82 Message transmission unit 83 Message DB
91 Message receiving unit 92 Duplex transmission / reception determining unit 93 Message receiving determining unit 94 Message display unit

Claims (4)

In a vehicle-to-vehicle communication method for storing a message received in vehicle-to-vehicle communication and transmitting the received message,
A vehicle-to-vehicle communication device that creates a message and transmits it first transmits identification information to the message,
Upon receiving the message, the inter-vehicle communication device checks whether the identification information of the message is stored in the built-in memory,
If the message is stored, discard the message; if not, process the message without discarding; store the identification information of the message in the memory; and transmit the message.
A vehicle-to-vehicle communication method, comprising: The storage time of the identification information is stored, and the identification information is deleted when a set time has elapsed.
The inter-vehicle communication method according to claim 1, wherein: The identification information is specified by the latitude and longitude of the point where the message was first transmitted, the time when the message was transmitted, and the size of the message.
The inter-vehicle communication method according to claim 1, wherein: In the vehicle-to-vehicle communication device that stores the message received by the vehicle-to-vehicle communication and transmits the received message,
Means for creating identification information of the message when the message is created and transmitted for the first time,
Means for adding identification information to the message and transmitting the message;
Means for storing identification information added to the received message,
When a message is received, it is checked whether the identification information of the message is stored in the storage means. If the identification information is stored, the message is discarded. If not stored, the message is processed without discarding. Control means for storing the identification information in the storage means,
A vehicle-to-vehicle communication device comprising:

Images