JP2007318433A - In-vehicle communication apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance the efficiency of road-vehicle communication by utilizing inter-vehicle communication. <P>SOLUTION: Its own vehicle C0 acquires a direction of a transmission base station A1 from another vehicle C1 driving in front of its own vehicle and making communication with the transmission base station A1 by the inter-vehicle communication. Its own vehicle C0 revises a direction of a directive antenna on the basis of the acquired direction and approaches the antenna in the direction of the transmission base station A1 to earlier and surely detect a radio wave transmitted from the transmission base station A1. Further, when map information around its own vehicle indicates a region of a sea wherein existence of a transmission base station is impossible, the in-vehicle communication apparatus excludes the region for searching a transmission base station to efficiently detect the transmission base station. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an in-vehicle communication device that communicates with the outside of a vehicle, and more particularly to an in-vehicle communication device that establishes communication with a target communication facility quickly and reliably.

  In recent years, technology that gives vehicles a communication function has been put into practical use, and the development of technology for vehicle-to-vehicle communication that communicates between vehicles and road-to-vehicle communication that communicates between specific facilities and access points and vehicles has advanced. Yes. Accordingly, for example, as disclosed in Patent Documents 1 to 3, a cooperative system of road-to-vehicle communication and vehicle-to-vehicle communication has been devised.

JP 2004-080383 A JP 2004-077281 A Japanese Patent No. 3094106

  Incidentally, in-vehicle communication devices have generally been difficult to improve in terms of cost and housing size. In addition, since communication is performed while moving at high speed, for example, a process of searching for a target transmission base station and establishing a connection frequently occurs.

  Therefore, in the communication in a vehicle, how quickly and efficiently establish a connection with a target communication destination with a limited performance is a very important issue.

  The present invention has been made to solve the above-described problems of the prior art, and an object thereof is to provide an in-vehicle communication device that makes road-to-vehicle communication more efficient through cooperation with vehicle-to-vehicle communication.

  In order to solve the above-described problems and achieve the object, the in-vehicle communication device according to the present invention acquires information on a target communication destination from another vehicle, and based on the information acquired from the other vehicle, the directional antenna of the own vehicle Control the direction of the.

  According to the present invention, the in-vehicle communication device acquires information on a target communication destination from another vehicle and controls the direction of the directional antenna of the own vehicle based on the information acquired from the other vehicle. There exists an effect that the vehicle-mounted communication apparatus which makes road-vehicle communication efficient by cooperation can be obtained.

  Exemplary embodiments of an in-vehicle communication device according to the present invention will be described below in detail with reference to the accompanying drawings.

  First, the concept of the present invention will be described with reference to FIG. In the figure, another vehicle C1 is traveling ahead of the host vehicle C0, and the other vehicle C1 communicates with the transmission base station A1. The own vehicle C0 acquires information on the transmission base station A1 from the other vehicle C1, and controls the direction of the directional antenna using the acquired information, map information around the own vehicle, and the like.

  By controlling the direction of the directional antenna, the directivity of the antenna can be made closer to the direction of the transmission base station A1, and radio waves emitted from the transmission base station A1 can be detected more quickly and reliably.

  Here, as the information of the transmission base station A1 acquired by the own vehicle C0 from the other vehicle C1, the position information of the transmission base station A1 can be used, but the direction of the transmission base station A1 from the other vehicle C1 is used. Also good. For example, if the other vehicle C1 is communicating with the transmission base station A1 using an antenna with variable directivity, the direction of the transmission base station A1 is estimated by acquiring the direction of the directional antenna of the other vehicle C1. can do.

  In addition, when the map information around the host vehicle indicates an area where there is no possibility of a transmission base station such as the sea, by searching for the transmission base station by excluding this area, the transmission base station Detection can be made more efficient.

  FIG. 2 shows a schematic configuration of the communication device mounted on the host vehicle C0. As shown in the figure, a communication device 1 mounted on a vehicle C0 is connected to a navigation device 2, a vehicle speed sensor 3, and another in-vehicle device 4.

  The navigation device 2 is an in-vehicle device that sets and guides a travel route using the position of the host vehicle specified by communicating with a GPS (Global Positioning System) artificial satellite and map data stored in advance. In addition, the navigation device 2 provides the communication device 1 with location information of the host vehicle, surrounding map information, a planned travel route, and the like.

  The vehicle speed sensor 3 detects the traveling speed of the vehicle C0 from the rotational speed of the tire and outputs it to the communication device 1. The in-vehicle device 4 is, for example, various devices of a vehicle travel control system that performs engine control and brake control based on data from the communication device 1.

  The communication device 1 includes a control unit 10, a communication unit 11, an antenna 14, a data storage unit 17, a gateway unit 18, and a directivity control unit 20 therein.

  The communication unit 11 is a communication processing unit that can be shared for communication with other vehicles (communication between vehicles) and communication with a base station (communication between road vehicles), WiMAX (world interoperability for microwave access), CDMA (Code Division Multiple Access), DSRC (Dedicated Short Range Communication), communication processing by w-LAN, etc., and data is decoded. The data storage unit 17 is a storage unit that stores various types of information such as information acquired by the communication unit 11.

  The antenna 14 has directivity, and the directivity direction and directivity strength can be changed. Specifically, the antenna 14 may be configured by an ESPAR antenna, a Yagi antenna, a parabolic antenna, or the like. The directivity control unit 20 executes the directivity control of the antenna 14 based on an instruction from the control unit 10.

  The gateway unit 18 is a device for transmitting data from the communication unit 11 connected by the control unit 10 to the in-vehicle device 4 or the navigation device 2 in the subsequent stage. For example, if the communication data is a map update, data is transmitted to the navigation device 2 via the gateway unit 18, and if the communication data is engine control maintenance data, it is transmitted to the in-vehicle device 4 via the gateway unit 18.

  The control unit 10 is realized by a microcomputer including a CPU, and is a control unit that performs network control for connecting, disconnecting, and monitoring the communication unit 11, and includes a base station information standby unit 10a, a base station search unit 10b, A base station communication unit 10c is included.

  The base station information standby unit 10a outputs a control instruction to the directivity control unit 20 to control the directivity of the antenna 14, and performs a process of waiting for the communication unit 11 to receive information about the base station from another vehicle.

  When the base station search unit 10b receives information about the base station from another vehicle, the base station search unit 10b outputs a control instruction to the directivity control unit 20 to control the directivity of the antenna 14, and performs a process of searching for the base station.

  The base station communication unit 10c performs communication with the base station when receiving a radio wave from the base station by searching for the base station, and outputs a control instruction to the directivity control unit 20 to control the directivity of the antenna 14. And improve the efficiency of communication with the base station.

  The processing operation of the control unit 10 will be described with reference to the flowchart of FIG. The processing flow shown in the figure is preferably part of a main routine that is repeatedly executed by the control unit 10, for example.

  When the process is started, the base station information standby unit 10a first executes base station information reception standby control (step S101). If base station information is received by this base station information reception standby control (Yes in step S102), the base station search unit 10b executes base station search control using the received base station information (step S103).

  As a result, when a radio wave from the transmission base station is detected and a communication connection with the transmission base station is established (step S104, Yes), the base station communication unit 10c executes communication control with the transmission base station (step S104). S105) When the communication with the transmission base station is completed (step S106, Yes), the process is terminated.

  Next, the specific contents of each control will be described. First, in the base station information reception standby control by the base station information standby unit 10a, as shown in FIG. 4, the antenna 14 is directed in front of the host vehicle C0 to wait for information reception regarding the base station from another vehicle. In this initial state, directivity is directed to the front of the host vehicle because the host vehicle is traveling, there is a possibility that the front vehicle establishes communication with the base station earlier than the host vehicle. This is because it is expensive.

  And if the direction of a base station is received from the other vehicle C1, the direction of directivity of the antenna 14 will be changed so that it may become the same direction as the antenna direction of the other vehicle C1. At this time, the direction of the antenna 14 is gradually changed while radio waves are detected by the communication unit 11 to search for a base station.

  Since the host vehicle C0 is located behind the other vehicle C1, the direction from the host vehicle C0 to the base station is more likely to be ahead of the direction from the other vehicle C1 to the base station. Therefore, in the stage before the communication with the base station is established, the direction from the own vehicle C0 to the base station is changed from the direction acquired from the other vehicle C1 by gradually changing the direction of the antenna 14 while performing radio wave detection. Even if it is shifted forward, communication with the base station can be established reliably and efficiently.

  Further, as shown in FIG. 5, when the direction of the base station is received from the other vehicle C1, the communication unit 11 changes the directivity direction of the antenna 14 so as to be the same direction as the antenna direction of the other vehicle C1. The base station may be searched by gradually changing the direction of the antenna 14 to the front side while performing radio wave detection.

  This base station information reception standby control and base station search control will be further described. As shown in FIG. 6, the other vehicle C1 first establishes communication with the base station A1 (enters the communication area of the base station A1). The antenna direction θ1 with respect to the traveling direction of the vehicle C1 is recorded.

  The establishment of communication means that the direction in which the reception efficiency is most optimal in the environment at that time is the antenna direction θ1. In addition, the position coordinates of the other vehicle C1 and the position coordinates of the base station, the communication form of the base station, the communication area, and the traveling speed of the other vehicle are also recorded. Further, after that time, the antenna direction changes each time another vehicle travels, but the changed antenna direction may be recorded as needed.

  Data (position information, traveling speed, antenna direction (θ1), base station position, base station communication mode, communication area, etc.) recorded by the other vehicle C1 is transmitted to the own vehicle C0 as information related to the communication destination, and the own vehicle C1 Uses information on the communication destination as communication preparation information for communicating with the target communication destination (base station A1).

  That is, the host vehicle C1 once records the received data and prepares to change the antenna direction based on the data. For example, the position when the other vehicle C1 establishes communication with the base station A1 is different from the predicted position of the own vehicle C1 (for example, when the traveling lanes of the other vehicle C1 and the own vehicle C0 are different). If there is, the deviation is calculated to correct the direction, and the antenna is directed to the obtained direction θ0.

  The predicted position where the host vehicle C0 enters the communication area of the communication base station A1 is the communication area predicted from the communication area of the base station received from the other vehicle C1 and the communication form (for example, base station coordinates and communicable distance) of the base station. And the position coordinates of the host vehicle can be specified and calculated by the GPS of the navigation device 2.

  In addition, you may memorize | store in advance in the navigation apparatus 2 in the own vehicle C0 about the position of a base station, a communication form, and a communication area.

  In addition to recording the position and antenna direction when another vehicle C1 enters the communication area of the base station A1 as shown in FIG. 6, and calculating the antenna direction when the own vehicle C0 also enters the communication area. For example, as shown in FIG. 7, the other vehicle C1 in the communication area records the antenna direction (direction of the base station A1) at that time, and the own vehicle C0 immediately controls the antenna direction to transmit the transmission base. The station A1 may be searched.

  By these operations, the optimum antenna direction corresponding to the environment at that time can be received from another vehicle, and the optimum antenna direction can be prepared in advance. Further, when the own vehicle establishes communication with the base station, the data may be transmitted to the subsequent other vehicle.

  In the transmission base station communication control after the communication with the base station is established, the base station communication unit 10c changes the direction of the antenna 14 following the change in the direction of the base station accompanying the movement of the host vehicle as shown in FIG. By controlling, it is controlled to be able to communicate with the base station longer and stably. In addition, what is necessary is just to acquire the movement state of the own vehicle from the navigation apparatus 2 or the vehicle speed sensor 3. FIG.

  Further, in the control of the directivity of the antenna 14, the strength of directivity may be changed in addition to the direction. For example, as shown in FIG. 9, in the base station information standby control, the base station information can be acquired from a wide range (wide angle) by directing the vehicle C0 forward and weakening directivity. In the communication control, the antenna is directed in the direction of the base station method, and the directivity is enhanced to enable stable communication farther.

  Next, the configuration and control of the communication apparatus when there are a plurality of directional antennas will be described. FIG. 10 is a schematic configuration diagram illustrating a schematic configuration of a communication apparatus having a plurality of directional antennas. As shown in the figure, the communication device 1a includes a control unit 10, communication units 11 to 16, antennas 14 to 16, a data storage unit 17, and a directivity control unit 21 therein.

  Similar to the communication unit 11, the communication units 12 and 13 are communication processing units that can be shared for communication with other vehicles (inter-vehicle communication) and communication with a base station (road-to-vehicle communication). Moreover, the antennas 15 and 16 have directivity like the antenna 14, and can change the direction of directivity and the strength of directivity. And the directivity control part 21 controls the directivity of the antennas 14-16 separately.

  Since other configurations and operations are the same as those of the communication apparatus 1 shown in FIG. 2, the same components are denoted by the same reference numerals and description thereof is omitted, and the antennas 14 to 16 by the directivity control unit 21 are hereinafter described. Control will be described.

  First, in base station information reception standby control, one of a plurality of antennas is directed forward to wait for information reception regarding a base station from another vehicle. Then, directions other than the front are distributed at equal intervals (equal angles) by other antennas.

  For example, in the base station information reception standby control when there are two antennas, one antenna is directed forward and the other antenna is directed rearward of the host vehicle as shown in FIG. When there are three antennas, control is performed so that one antenna is directed forward and the directions of the other antennas are shifted by 120 degrees as shown in FIG.

  Here, when there is a region where there is no possibility that the base station exists (and there is no possibility that another vehicle exists), for example, when the own vehicle is traveling along the coast, FIG. As shown in FIG. 4, by determining the directivity distribution of the antennas 14 to 16 by excluding the direction of the area, it is possible to efficiently wait for base station information.

  Also in base station search control and base station communication control, directivity control can be performed by excluding the direction of a region where there is no possibility that a base station exists. In addition, what is necessary is just to acquire and use the information around this own vehicle from the navigation apparatus 2, for example.

  When the direction of the base station is acquired from the other vehicle C1, as shown in FIG. 14, the directivity control unit 21 searches the base station for the antenna closest to the acquired direction from the antennas 14 to 16, and the base station. It is in charge of communication with. Here, the directivity control of the antenna in charge of searching for the base station is the same as in the communication apparatus 1.

  In base station communication control after communication with the transmitting base station is established, as shown in FIG. 15, the direction of the antenna in charge of communication with the base station follows the change in the direction of the base station as the vehicle moves. And control. Furthermore, the antenna in charge of communication with the base station may be switched depending on a change in the positional relationship between the host vehicle and the base station.

  Here, during the base station communication control, the directivity of the antenna other than the antenna in communication with the base station is set so that the directions other than the antenna in communication are equally spaced (equal angle) as shown in FIG. As shown in FIG. 16, as shown in FIG. 16, at least one of the antennas other than the communicating antenna may be directed in the front direction of the host vehicle so that communication with another vehicle in front is possible. .

  In this way, even when communicating with a base station, by making it possible to acquire base station information from other vehicles (particularly ahead vehicles), the direction of the base station to be connected next to the currently communicating base station can be determined. It is possible to acquire the information in advance and continue communication with the base station.

  By the way, in the communication apparatus 1 and the communication apparatus 1a, the case where this invention is applied using the antenna which can change the directionality of directivity was demonstrated, However, even if it switches and uses a directional antenna with a fixed direction, this communication is also demonstrated. The invention can be implemented.

  FIG. 17 is a schematic configuration diagram illustrating a schematic configuration of a communication apparatus when a directionally fixed directional antenna is switched. As shown in the figure, the communication device 1b includes a control unit 10, communication units 11 to 16, antennas 31 to 33, a data storage unit 17, a directivity control unit 22, and a switching mechanism 23 therein.

  The antennas 31 to 33 are directional antennas whose directions are fixed, and the directions thereof are different from each other. The antennas 31 to 33 are connected to the communication units 11 to 13 via the switching mechanism 23.

  The switching mechanism 23 is a switch that arbitrarily switches the connection between the communication units 11 to 13 and the antennas 31 to 33, and the directivity control unit 22 realizes switching of the communication direction by the control of the switching mechanism 23.

  Since other configurations and operations are the same as those of the communication device 1 shown in FIG. 2 and the communication device 1a shown in FIG. 10, the same components are denoted by the same reference numerals and description thereof is omitted.

  As described above, the communication devices 1, 1a, 1b according to the present embodiment acquire information on the transmission base station from other vehicles, for example, the direction of the base station, and use the acquired information to determine the direction of the directional antenna. Since control is performed and communication with the target base station, communication with the base station can be established more quickly and reliably, and efficient road-to-vehicle communication can be performed.

  In addition, when the map information around the host vehicle indicates an area where there is no possibility of a transmission base station such as the sea, by searching for the transmission base station by excluding this area, the transmission base station Detection can be made more efficient.

  As described above, the in-vehicle communication device according to the present invention is useful for communication control in a vehicle and is particularly suitable for improving the efficiency of road-to-vehicle communication.

It is a conceptual diagram explaining the concept of this invention. It is a schematic block diagram which shows the schematic structure of the communication apparatus concerning the Example of this invention. It is a flowchart explaining the processing operation of the control part 10 shown in FIG. It is explanatory drawing explaining the search operation of a base station (the 1). It is explanatory drawing explaining the search operation of a base station (the 2). It is a detailed example of base station information reception standby control and base station search control (part 1). This is a detailed example of base station information reception standby control and base station search control (part 2). It is explanatory drawing explaining the directivity control at the time of communication with a base station. It is explanatory drawing explaining the change of directivity intensity | strength. It is a schematic block diagram which shows the schematic structure of the communication apparatus which has a some antenna. It is explanatory drawing explaining the base station information reception standby by two antennas. It is explanatory drawing explaining the base station information reception waiting by three antennas. It is explanatory drawing explaining the base station information reception standby using map information. It is explanatory drawing explaining the base station search control in the case of a multiple antenna. It is explanatory drawing explaining the directivity control at the time of communication with a base station (the 1). It is explanatory drawing explaining the directivity control at the time of communication with a base station (the 2). It is a schematic block diagram which shows the schematic structure of the communication apparatus in the case of switching a directionally fixed directional antenna.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Communication apparatus 2 Navigation apparatus 3 Vehicle speed sensor 4 In-vehicle apparatus 10 Control part 10a Base station information standby part 10b Base station search part 10c Base station communication part 11-13 Communication part 14-16, 31-33 Antenna 17 Data storage part 18 Gateway Unit 20-22 Directivity control unit 23 Switching mechanism A1 Transmission base station C0 Own vehicle C1 Other vehicle

Claims (10)

Information acquisition means for acquiring communication preparation information for communicating with the communication destination from another vehicle for a communication destination communicating with the own vehicle;
Directivity control means for controlling the direction of a directional antenna that communicates with a communication destination provided in the host vehicle based on communication preparation information acquired from the other vehicle;
An in-vehicle communication device comprising:   2. The information acquisition unit according to claim 1, wherein the information acquisition unit acquires a direction from the other vehicle to the communication destination, and the directivity control unit controls the directional antenna based on the acquired direction. The vehicle-mounted communication apparatus of description.   The in-vehicle communication device according to claim 2, wherein the directivity control unit controls the direction of the directional antenna in the same direction as the acquired direction while performing radio wave detection by the directional antenna.   4. The directivity control unit according to claim 2 or 3, wherein the directivity control means performs radio wave detection while controlling the directional antenna in a direction in front of the host vehicle after directing the directional antenna in the same direction as the acquired direction. In-vehicle communication device.   A plurality of the directional antennas are provided, and the directivity control unit causes a directional antenna in a direction closest to the acquired direction to be in charge of communication with the target communication destination among the plurality of directional antennas. The in-vehicle communication device according to claim 2, 3 or 4.   The in-vehicle communication device according to claim 1, wherein the information acquisition unit receives communication preparation information transmitted from the other vehicle by the directional antenna.   The in-vehicle communication device according to claim 6, wherein the directivity control unit directs the directional antenna in a forward direction of the host vehicle in a state in which information from the other vehicle is on standby.   A plurality of the directional antennas, wherein the directivity control means directs at least one of the plurality of directional antennas forward of the host vehicle in a state of waiting for information from the other vehicle. The in-vehicle communication device according to claim 6.   When the communication with the target communication destination is established, the directivity control means controls the direction of the directional antenna following the change in the communication destination direction accompanying the movement of the host vehicle. The in-vehicle communication device according to any one of claims 1 to 8.   A plurality of the directional antennas are provided, and the directivity control means directs at least one of the directional antennas other than the directional antenna in communication with the target communication destination in the forward direction of the host vehicle. The in-vehicle communication device according to claim 9.

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