JP5280907B2 - On-vehicle communication device, wireless connection method, and program - Google Patents

Description

  The present invention relates to communication between a wireless LAN ground communication device scattered along a railway line and a train communication device on a train.

  Patent Document 1 “Mobile LAN Device, Wireless LAN Connection Setting Method” (Japanese Patent Laid-Open No. 2008-271063) completes the wireless LAN setting of the mobile before entering the communicable range of the wireless LAN access point. Is. The location information and setting information of the access point are stored, and the setting of the access point to be connected soon from the current location information is performed in advance.

  In this technique, when a plurality of access points become candidates for connection, the user is allowed to select where to connect, and cannot be automatically selected. Further, the purpose is to quickly connect to an access point, and it is not intended to forcibly disconnect a connected radio and connect it to another access point.

  Patent Document 2 “Selection Method and Method for Calling in Mobile Communication” (Japanese Patent Application Laid-Open No. 2001-203829) searches the charge table from the current position of mobile communication and the receiving area, and is the cheapest carrier. This is a method of automatically selecting an access point.

  In this application, it is not intended to change the access point to be connected when the mobile terminal moves or to simultaneously connect to a plurality of access points.

  Many conventional technologies are based on the premise that terrestrial wireless LAN devices are connected by a backbone network, and any on-vehicle communication device (such as a wireless LAN access point) may be used as long as the on-vehicle communication device can be connected. Communication between the top was possible. Communication continuity has been ensured by so-called “high-speed handover technology”. As a result, the on-board computer connected to the on-board communication device can communicate with an arbitrary computer connected to the terrestrial backbone network at a necessary timing.

  On the other hand, when the backbone is not configured along the line or when it is not necessary to configure it, the on-board communication device needs to be connected to a specific ground communication device at a necessary timing. For example, it is a case where a railroad crossing or a station along the line creates an isolated wireless area. In this case, the train must be connected to the ground communication device at the level crossing when it reaches a certain distance (α meter) before the level crossing. Assumed communication traffic is the transfer of the image of the surveillance camera installed at the level crossing to the vehicle, the transmission of the level crossing operation state to the vehicle, the transmission of control information for controlling the operation of the level crossing from the vehicle, etc. is there.

  However, since there are many railroad crossings, it is not possible to determine the connection partner only by electrical conditions such as “strong radio waves”. In addition, the connection with the next level crossing must be immediately released after passing the level crossing, and the connection must be prepared for communication with the next level crossing. Prompt disconnection is also necessary in order to remove unnecessary communication traffic and smoothly perform communication with other trains. The connection / disconnection timing also varies depending on the traveling direction (see FIG. 15).

  FIG. 15 is a diagram showing an outline of the assumed case 1. Reference numerals 1501 and 1502 denote the wireless reach ranges of the ground communication devices at level crossings A and B, respectively. When the train passes in the direction from level crossing i to level crossing (1503 to 1505) and when the train passes from level crossing to the level crossing i (1506 to 1508), the connection timing and the disconnection timing differ. In particular, in the portion where the wireless coverage areas of both ground communication devices shown in 1509 overlap, which ground communication device is connected depends on the traveling direction.

Furthermore, since the railroad crossings may be installed close to each other, a plurality of communication means may be required. Therefore, it is necessary to schedule which communication means is used for connection with which ground communication device at which timing (see FIG. 16).

  FIG. 16 is a diagram schematically illustrating the assumed case 2. Reference numerals 1601, 1602, 1603, and 1604 denote the radio reachable ranges of the ground communication devices of level crossing A, level crossing B, level crossing C, and level crossing D, respectively. Reference numerals 1605, 1606, 1607, and 1608 denote sections of connection with the ground communication devices of level crossings I, level crossings B, level crossings C, and level crossings D, respectively. Since these connection sections overlap with the preceding and subsequent connection sections, a continuous connection state cannot be realized with only a single communication means. In addition, when there are a plurality of communication means, appropriate scheduling is required.

  The prior art cannot cope with any of the above-described use environments.

JP 2008-271063 A JP 2001-203829 A

  It is an object of the present invention to secure a necessary communication path with a communication partner by dynamically connecting / disconnecting based on the train position, traveling direction, position data of the ground communication device, and the like. .

An on-vehicle communication device according to one aspect of the present invention is an on-vehicle communication device mounted on a mobile body to perform wireless communication with a plurality of ground communication devices installed along a route of transportation, A plurality of wireless means that can be wirelessly connected to the ground communication device, a ground communication device table that stores a communication section on the route and a traveling direction with respect to the route in association with the plurality of ground communication devices, and a current position of the mobile unit , rare containing a communication section that is stored in association with the ground communication device is not connected, and the current traveling direction of the moving body, that matches the traveling direction stored in association with the ground communication unit If, the ground communication apparatus determines that the connection object, a connection establishment module for controlling the radio unit unconnected to transmit a connection request to the connection target determined to be ground communication device, the connection establishment module Work concurrently, if the current position of the moving body, included not in communication section that is stored in association with the ground communication unit being connected, connected to release the connection with the ground communication unit and a disconnect module for controlling the wireless unit in.

Wireless connection method according to one aspect of the present onset Ming is mounted on a mobile body in order to perform a plurality of ground communication devices and wireless communication which is installed along the transportation line, (i) ground communication apparatus by radio a plurality of radio means which can be connected by, Oite the on-board communication device and a ground communication device table for storing in association with the traveling direction to the plurality of ground communication devices to the communication section and line on (ii) route a reference is that the wireless connection method, the current position of the moving body, rarely contains a communication section that is stored in association with the ground communication device is not connected, and the current traveling direction of the moving body, the ground If that matches the traveling direction stored in association with the communication device, determines the ground communication apparatus and the connection target, non to transmit a connection request to the connection target determined to be ground communication device Control the wireless means of connection A connection establishment step that the connection establishment step and are concurrently performed, when the current position of the moving body, included not in communication section that is stored in association with the ground communication unit being connected, the ground and a disconnect step of controlling the radio unit being connected so as to release the connection with the communication device.

A program according to one aspect of the present onset Ming is mounted on a mobile body in order to perform a plurality of ground communication devices and wireless communication which is installed along the transportation line, connected by (i) ground communication apparatus by radio a plurality of radio means which can, in a program used in the on-board communication device and a ground communication device table for storing in association with the traveling direction to the plurality of ground communication devices to the communication section and line on (ii) route there are, current position of the moving body, rarely contains a communication section that is stored in association with the ground communication device is not connected, and the current traveling direction of the moving body, stored in association with the ground communication unit If that matches the traveling direction being determines the ground communication apparatus and the connection target, controls the radio unit unconnected to transmit a connection request to the connection target determined to be ground communication device A connection establishment procedure, the connection establishment procedure is performed simultaneously in parallel, if the current position of the moving body, included not in communication section that is stored in association with the ground communication unit being connected, the terrestrial communications The CPU is caused to execute a connection release procedure for controlling the wireless means being connected so as to release the connection with the apparatus.

  An appropriate wireless communication line can be reliably configured only in a necessary section, and unnecessary communication traffic can be suppressed.

It is a figure which shows the hardware constitutions of a vehicle-mounted communication apparatus. It is a figure which shows the module structure of the software of a vehicle-mounted communication apparatus. It is a figure which shows the example of a ground communication apparatus table. It is a figure which shows the structure of a ground communication apparatus. It is a figure which shows the example of an on-vehicle wireless means table. It is a figure which shows the data flow which concerns on a connection establishment process. It is a figure which shows the connection establishment process flow. It is a figure which shows a connection target determination processing flow. It is a figure which shows a connection request processing flow. It is a figure which shows a connection table update process flow. It is a figure which shows the data flow which concerns on a connection cancellation | release process. It is a figure which shows a connection cancellation | release process flow. It is a figure which shows an unconnected table update process flow. It is a figure which shows a device monitoring process flow. It is a figure which shows the outline | summary of the assumption case 1. FIG. It is a figure which shows the assumption case 2.

  In the present invention, the on-board communication device mounted on the train acquires the train position information and the traveling direction from the train control signal and monitor device, and records the ground communication device table (communication with the ground communication device) in advance. Starting point and ending point, usable wireless communication means, wireless conditions, etc.) and on-board wireless means table (wireless communication means used by the wireless device, connected ground communication device if connected, etc.) Referring to Fig. 4, the ground communication device to be connected is determined, and connection and disconnection are performed.

  First, an outline of the operation will be described with reference to FIG. When traveling in the right direction in the figure, when the train approaches the railroad crossing ii, the on-board communication device is connected to the ground communication device of the railroad crossing ii (1503). Is disconnected and a new ground communication device is connected (1504). Then, when the railroad crossing passes, the connection with the ground communication device of the railroad crossing is disconnected (1505). On the contrary, when traveling in the left direction, when the train approaches the level crossing, the on-board communication device is connected to the ground communication device of the level crossing (1506), and immediately after passing the level crossing, the on-vehicle communication device The connection is disconnected and a new ground communication device is connected (1507). When the railroad crossing passes, the connection with the ground communication device of the railroad crossing is cut off (1508).

  Next, an outline of the operation will be described with reference to FIG. The on-board communication device has two wireless means (wireless LAN devices). Then, when the train approaches the railroad crossing ii, the on-board communication device is connected to the ground communication device of the railroad crossing ii using the first wireless means (1605). (1606) is connected to the ground communication device at the level crossing. Then, when the railroad crossing is passed, the connection of the first wireless means is disconnected. Next, when approaching level crossing C, the on-board communication device connects to the ground communication device of level crossing C using the first wireless means (1607), and disconnects the second wireless means when passing through level crossing B. In this way, a connection state is continuously secured with a plurality of approaching ground communication devices while switching between the two wireless means. In the figure, 1605 and 1607 are connection ranges by the first wireless means, and 1606 and 1608 are connection ranges by the second wireless means.

  FIG. 1 is a diagram illustrating a hardware configuration of the on-vehicle communication device. The on-vehicle communication device includes a CPU 101, a memory 102, an HDD 103, wireless LAN devices 104 a to 104 c, a position information receiving unit 105, and a traveling direction receiving unit 106. The CPU 101 is an example of an arithmetic device, and the memory 102 and the HDD 103 are examples of a storage device. The program is normally stored in the HDD 103, and is loaded into the memory 102 and sequentially read into the CPU 101 for processing. The wireless LAN device 104 is used for wireless LAN communication. Thereby, communication with an unrelated LAN access point of the ground communication device is controlled. The position information receiving unit 105 is configured to acquire the current position, and the traveling direction receiving unit 106 is configured to acquire the traveling direction of the train.

  FIG. 2 is a diagram showing a software module configuration of the on-board communication device. The on-board communication device includes a ground communication device table 201, an on-board wireless means table 202, a connection establishment module 203, a connection release module 204, a device monitoring module 205, and wireless LAN device drivers 206a to 206c. The ground communication device table 201 manages information related to the ground communication device, and the on-vehicle wireless device table 202 manages information related to the wireless device included in the on-vehicle communication device. The wireless LAN device driver 206 is a wireless LAN device driver. The connection establishment module 203 operates to establish a communication state with the ground communication device using the wireless LAN device driver 206 based on the ground communication device table 201 and the on-vehicle wireless means table 202, and the connection release module 204 Based on the ground communication device table 201 and the on-vehicle wireless means table 202, the wireless LAN device driver 206 is used to cancel the communication state with the ground communication device. The device monitoring module 205 operates to acquire the state of the wireless LAN device 104 via the wireless LAN device driver 206 and update the on-vehicle wireless means table 202. In this example, the connection establishment module 203, the connection release module 204, and the device monitoring module 205 operate simultaneously in parallel. However, these can be repeatedly operated sequentially.

  FIG. 3 is a diagram illustrating an example of the ground communication device table. The terrestrial communication device table 201 has a record for each terrestrial communication device, the name of the terrestrial communication device, the traveling direction, the communication section (upstream end point, downstream end point), wireless system, SSID (Service Set Identifier), authentication / security. Information, channels, and connection status items are stored in association with each other. Further, when the ground communication device has a plurality of wireless means (wireless LAN access points) as in a railroad crossing C, the wireless method, SSID (Service Set Identifier), authentication / security information, channel, and The connection state is associated and stored. The SSID is an example of an access point identifier in the wireless LAN. The traveling direction is the traveling direction of the train and is “up” or “down”. The communication section is a communication range, and is specified by an upstream end point and a downstream end point that are positions on the route. The position on the route is represented by the distance from the reference point on the route. The connection status distinguishes between “connected” and “not connected”.

  FIG. 4 is a diagram illustrating a configuration of the ground communication device. The ground communication device includes a wireless LAN access point 401x, a wireless LAN access point 401y, a switching hub 402, and a railroad crossing control device 403. In this example, an example having two wireless LAN access points 401 is shown, but there may be three or more. There may also be a singular.

  FIG. 5 is a diagram showing an example of the on-vehicle wireless means table. A record is provided for each wireless means (wireless LAN device), and the name of the wireless means, the wireless system, the operation state, the connection state, and the connection partner items are stored in association with each other. The operating state distinguishes between “operating” that is operating and “stopping” that is not operating. The connection status distinguishes between “connected” and “not connected”. The connection partner identifies the name of the connection destination ground communication device when connected (example of ground communication device identification information), and when not connected, distinguishes the partnerless code.

  Subsequently, each operation will be described in order. First, the operation of the connection establishment module 203 will be described. FIG. 6 is a diagram illustrating a data flow related to the connection establishment process. The connection establishment module 203 acquires information for determining a connection target and information for requesting connection from the ground communication device table 201 and the on-vehicle wireless means table 202, and when connected, the ground communication device table 201 And the connection state and connection partner of the on-board wireless means table 202 are updated. Further, the position information is acquired from the position information receiving unit 105, and the traveling direction is acquired from the traveling direction receiving unit 106. Further, a connection is requested via the wireless LAN device driver 206.

  FIG. 7 is a diagram showing a connection establishment process flow. First, in the connection target ground communication device determination process (S701), the ground communication device to be connected is determined. This process will be described later with reference to FIG. And when there exists a connection object, the process (S703-S707) which performs a connection request | requirement is repeated as needed about each of the ground communication apparatus (S702).

  Information regarding the wireless means of the ground communication device to be connected is acquired from the ground communication device table 201. If there are a plurality of wireless means, the following processing is repeated for each of the wireless means (S703). If the connection state of the wireless means is “connected”, the processing for the ground communication device is finished. On the other hand, when the connection state of the wireless unit is “not connected”, a connection request is made to the wireless unit (S705). This process will be described later with reference to FIG. As a result, when the connection is successful, the processing for the ground communication device is finished. On the other hand, if the connection fails, the processing by other wireless means is repeated. Then, when the connection fails by any unrelated means (S707), the processing for the ground communication device is finished. Then, when all the ground communication devices to be connected are processed (S708), the process returns to S701. In this way, the connection establishment process continues to operate during train operation.

  FIG. 8 is a diagram illustrating a flow of the connection target determination process (S701). First, position information is acquired (S801), and a traveling direction is specified (S802). Then, the following processing is repeated for each ground communication device in the ground communication device table 201 (S803). The identified traveling direction matches the traveling direction associated with the ground communication device in the ground communication device table 201 (S804), and the acquired position information is associated with the ground communication device in the communication device table 201. When it is included in the communication section (S805), it is determined that the ground communication device is connected to the ground communication device (S806). If the traveling directions do not match and the position information is not included in the communication section, it is not a connection target. Then, the process ends when all the ground communication devices have been processed (S807).

  FIG. 9 is a diagram showing a flow of connection request processing (S705). The following processing is repeated for each wireless means in the on-vehicle wireless means table 202 (S901). The wireless method of the wireless means of the on-board communication device matches the wireless method of the wireless means of the ground communication device (S902), the operating state of the wireless means of the on-board communication device is operating (S903), When the connection state of the wireless means of the communication apparatus is not connected (S904), the SSID, authentication information, channel, etc. are set in the wireless LAN device via the wireless LAN device driver 206 to start communication (S905). ). The wireless LAN device accesses a wireless LAN access point specified by the SSID through a designated channel. Then, a connection request command including security information is transmitted. When the authentication result is successful (S906), the terrestrial communication device table 201 and the on-board wireless means table 202 are updated by the connecting table update process (S908), and the end status is terminated as success (S909). On the other hand, when the wireless method of the wireless means of the on-board communication device does not match the wireless method of the wireless means of the ground communication device (S902), the operation state of the wireless means of the on-board communication device is stopped (S903). If the connection state of the wireless means of the on-board communication device is being connected (S904), the process is repeated for other wireless means of the on-board communication device (S907). If all wireless means have been processed and no connection has succeeded, the end status is set as failure (S910).

  FIG. 10 is a diagram showing a flow of the connected table update process (S908). The connection state corresponding to the wireless means in the on-vehicle wireless means table is updated to “connected” (S1001), and the ground communication device is written to the connection partner corresponding to the wireless means in the on-vehicle wireless means table (S1002). . Furthermore, the connection state corresponding to the wireless means in the ground communication device table is updated to “connected” (S1003).

  Next, the operation of the connection release module 204 will be described. FIG. 11 is a diagram illustrating a data flow related to the connection release processing. The connection release module 204 acquires information for determining a target to be disconnected from the terrestrial communication device table 201 and the on-vehicle wireless means table 202, and when the connection is released, the terrestrial communication device table 201 and the on-vehicle wireless The connection state and connection partner in the means table 202 are updated. In addition, the location information is acquired from the location information receiving unit 105, and the connection is instructed via the wireless LAN device driver 206.

  FIG. 12 is a diagram illustrating a connection release processing flow. The following processing is repeated for each wireless means in the on-vehicle wireless means table 202 (S1201). When the wireless device is operating (S1202), the wireless device is connected (S1203), and the current position is outside the communication section of the wireless device, the connection is disconnected. In order to determine whether the current position is outside the communication section of the wireless means, the name of the ground communication device is read from the connection partner of the wireless means (S1204), and the communication section corresponding to the ground communication device is determined from the ground communication device table 201. Read (S1205). Further, the position information is acquired from the position information receiving unit 105 (S1206), and it is determined whether the position information is included in the communication section (S1207). If it is determined to disconnect, the wireless LAN device 104 terminates communication via the wireless LAN device driver 206 (S1208). As a result, the wireless LAN device 104 transmits a connection release command to the ground communication device. Then, the ground communication device table 201 and the on-board wireless means table 202 are updated by the unconnected table update process (S1209). On the other hand, when the operation state of the wireless means is stopped (S1202), when the connection state of the wireless means is not connected (S1203), and when the current position is not outside the communication section of the wireless means, connection release processing is performed. Do not do. When these processes are performed for all wireless means, the process is terminated (S1210).

  FIG. 13 is a diagram showing the flow of the unconnected table update process (S1209). The connection state corresponding to the wireless means in the on-vehicle wireless means table 202 is updated to “not connected” (S1301), and the partnerless code is written to the connected counterpart corresponding to the wireless means in the on-vehicle wireless means table 202 (S1302). ). Further, the connection state corresponding to the wireless means in the ground communication device table 201 is updated to “not connected” (S1303).

  Finally, processing of the device monitoring module 205 will be described. FIG. 14 is a diagram showing a device monitoring process flow. The following processing is repeated for each wireless means in the on-vehicle wireless means table (S1401). The operating state is acquired from the wireless LAN device 104 via the wireless LAN device driver 206 (S1402), and the wireless unit in the on-board wireless unit table 202 is updated to the acquired operating state (S1403). When all the wireless means are processed (S1404), after waiting for a predetermined time (S1405), the above process is repeated.

  The on-vehicle communication device and the ground communication device are computers, and each element can execute processing by a program. Further, the program can be stored in a storage medium so that the computer can read the program from the storage medium.

  In the above-described example, the case where the present invention is applied to a railway has been described.

101 CPU
102 Memory 103 HDD
104a to 104c Wireless LAN device 105 Position information receiving unit 106 Traveling direction receiving unit 201 Ground communication device table 202 On-vehicle wireless means table 203 Connection establishment module 204 Connection release module 205 Device monitoring module 206a to 206c Wireless LAN device driver 401x, 401y Wireless LAN access point 402 Switching hub 403 Railroad crossing control device

Claims (6)

An on-vehicle communication device mounted on a mobile body to perform wireless communication with a plurality of ground communication devices installed along a route of transportation,
A plurality of wireless means connectable to the ground communication device wirelessly;
A ground communication device table for storing a communication section on a route and a traveling direction for the route in association with the plurality of ground communication devices ;
Current position of the moving body, rarely contains a communication section that is stored in association with the ground communication device is not connected, and the current traveling direction of the moving body, are stored in association with the ground communication unit If that matches the traveling direction, connection establishment module determines the ground communication apparatus and the connection target, controls the radio unit unconnected to transmit a connection request to the connection target determined to be ground communication device When,
The connection establishing module operates simultaneously in parallel and, when the current position of the moving body, no included in the communication section that is stored in association with the ground communication unit being connected, the connection with the ground communication unit A disconnection module that controls the wireless means being connected to release ;
An on-vehicle communication device . Before Symbol ground communication device table further stores wireless communication conditions of the ground communication system,
The connection establishment module selects a wireless unit conforming to the wireless communication conditions of the connection object and the determined ground communication device, transmits a connection request according to the wireless communication conditions using the radio means selected, claims 1 Symbol placement on-board communication device. It said plurality of radio unit is a wireless LAN device, the on-board communication device according to claim 1 or 2, wherein. The route is a railroad, the moving body is a train, the on-board communication device of any one of claims 1 to 3. (I) a plurality of wireless means mounted on a mobile body for wireless communication with a plurality of ground communication devices installed along a route of transportation , and (ii) a route connected to the ground communication device by radio; a wireless connection method that is used Oite the on-board communication device and a ground communication device table for storing the traveling direction to the communication section and routes above in association with the plurality of ground communication devices,
Current position of the moving body, rarely contains a communication section that is stored in association with the ground communication device is not connected, and the current traveling direction of the moving body, are stored in association with the ground communication unit If that matches the traveling direction, connection establishment step of determining the ground communication apparatus and the connection target, controls the radio unit unconnected to transmit a connection request to the connection target determined to be ground communication device When,
The connection establishment step and are concurrently performed, when the current position of the moving body, no included in the communication section that is stored in association with the ground communication unit being connected, the connection with the ground communication unit A connection release step for controlling the wireless means being connected to release ;
A wireless connection method . (I) a plurality of wireless means mounted on a mobile body for wireless communication with a plurality of ground communication devices installed along a route of transportation , and (ii) a route connected to the ground communication device by radio; a program used in a vehicle on a communication device having a ground communication device table for storing the traveling direction to the communication section and routes above in association with the plurality of ground communication devices,
Current position of the moving body, rarely contains a communication section that is stored in association with the ground communication device is not connected, and the current traveling direction of the moving body, are stored in association with the ground communication unit If that matches the traveling direction, connection establishment procedure determines the ground communication apparatus and the connection target, controls the radio unit unconnected to transmit a connection request to the connection target determined to be ground communication device When,
The connection establishment procedure is performed simultaneously in parallel, if the current position of the moving body, no included in the communication section that is stored in association with the ground communication unit being connected, the connection with the ground communication unit A disconnection procedure for controlling the connected wireless means to cancel ,
That causes the CPU to execute .

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