JP4170180B2 - On-board device for narrow area communication - Google Patents

Description

  This field relates to an in-vehicle device for narrow area communication that is connected to, for example, an IP network and used for content browsing and large-capacity data transmission / reception.

An ETC system is known as an application using narrow area communication (see, for example, Patent Document 1).
According to the standard, for example, “Narrowband Communication (DSRC) System Standard ARIB STD-T75” defined by the Japan Radio Industry Association, a communication frame is time-divided into fixed-length sections called slots. The slot for controlling the communication frame is a reference for the slot in the communication frame, and is constantly transmitted periodically from the road device. The slot for controlling the communication frame includes information such as the configuration of the slot in the communication frame and the assignment of the on-vehicle device to each slot. The on-vehicle device includes information on the slot for controlling the received communication frame. Operate based on. When the vehicle-mounted device detects a communicable area based on the radio field strength, it uses a slot for requesting connection for data communication, and requests its own vehicle-mounted device to allocate a data transmission / reception slot. When the road device detects a new on-vehicle device in a slot that requires connection, the road device allocates a data transmission / reception slot to the on-vehicle device and starts data communication. In the initial stage of data communication, the road unit and the vehicle-mounted device exchange communication profiles and installed application lists with each other, and when the communication profiles that can be communicated are combined and the installed applications match, both continue communication.

  In these systems, vehicles equipped with in-vehicle devices must pass through a defined communication area where the radio wave environment is good, and the amount of data sent and received between road units and in-vehicle devices is small. Even when necessary communication is completed and there is a vehicle equipped with a plurality of vehicle-mounted devices in the communication area, the processing capability of the road unit is not exceeded.

  Therefore, the user does not need to enter into an area in which communication with the roadside device can be actively performed in consideration of communication, and the user does not need to know the communication area and communication state of the roadside device and the vehicle-mounted device.

JP 2002-353879 A

In the future, it is assumed that the narrow-area communication system is connected to, for example, an IP network and used for browsing content and transmitting / receiving large amounts of data.
In such a communication system, a vehicle equipped with a vehicle-mounted device moves to a communication area where it can actively communicate with a road device and receives a service. The area that can communicate with the road unit does not necessarily exist uniformly at a certain distance from the road unit, but there are places where the electric field strength is strong and weak within a certain distance of the road unit. There is a problem that it is generally difficult to determine whether a vehicle has entered an area.
There is a method of knowing whether or not the determination is made based on whether or not the service is started. However, since it generally takes time until the service is started after entering the communication area, there is a problem that it takes time until the determination.

  The communicable area includes an area where communication is possible but the radio wave environment is poor and the data transfer efficiency is low. In such a case, if the vehicle is moved to a position where the radio wave environment is good, communication can be performed with high transmission efficiency. However, the user has a means to know that the data transfer efficiency is low and that the data transfer efficiency is low. Therefore, there is a problem in that communication is continued with low data transfer efficiency and time is wasted.

  In addition, the radio wave environment may deteriorate due to another vehicle entering the communication area when receiving the service. In such a case, it is only necessary to move again to a communication area where the radio wave environment is good, but the user has no means of grasping the communication state and is forced to waste time by continuing communication with a low data transfer efficiency. There is a problem.

On the other hand, with the expansion of the narrow area communication standard and the increase of applications using the narrow area communication, it is possible that the applications installed between the road device and the vehicle-mounted device that have been made multi-applications may differ. Communication is not possible if the standards and applications differ between the road unit and the vehicle-mounted device.
In this case, the vehicle-mounted device needs to search for another communicable road device.

Further, when a road device is connected to the maximum number of on-vehicle devices that can be connected, the on-vehicle device that has newly entered the communication area cannot communicate with the road device.
However, if the connected vehicle-mounted device cuts off the communication, the vehicle-mounted device that has newly entered the communication area can communicate with the road device. Therefore, the vehicle-mounted device can wait for a state where it can communicate with the road device and communicate with the road device, and can search for another road device with which communication is possible.
However, there is a problem that the user cannot recognize the cause and the cause of the inability of the road unit and the vehicle-mounted device to communicate, and cannot determine whether or not the road device can be used thereafter. .

In addition, the on-board unit can be used depending on the communication connection of multiple on-board units to the road unit, the use of each application by the plurality of on-board units, the data transmission / reception capability of the road unit, the amount of data transmission / reception errors between the on-road unit and the on-board unit, etc. The data transmission / reception speed changes.
The user decides whether to send / receive data on the spot based on the time required for transmission / reception, especially when sending / receiving large data, but it is necessary to know the transfer speed in advance and send / receive data. Can be predicted, whether data transmission / reception is performed or not can be determined according to the communication status.
However, at present, there is no provision of information such as data transmission / reception time and transfer speed to the user, and it is necessary to recognize the time required for data transmission / reception after data transmission / reception once. Accordingly, there is a problem in that it is impossible to select whether to perform data transmission / reception or to select a base station.

An object of the present invention is to solve the above-described problems, and provides information regarding a communication state with a road device to a user, and enables communication without waste. An on-vehicle device is provided.
Moreover, the information regarding the connection state with a roadside apparatus is provided to a user, and the vehicle-mounted device for narrow area communication which enabled the wasteless communication is provided.

An on-vehicle device for narrow area communication according to the present invention includes an antenna that transmits and receives to / from a road device, a wireless communication unit that is connected to the antenna and transmits / receives to / from the road device via an antenna, and is connected to the wireless communication unit. And a control microcomputer having a function of supplying a necessary control signal to the wireless communication unit and receiving a signal from the wireless communication unit and executing a predetermined application based on the built-in program, and the control microcomputer The control microcomputer is incapable of connection due to a difference in communication profile or application owned by the roadside device when the control microcomputer cannot be connected to the roadside device at the time of initial connection with the roadside device. It is a combination or connected to the maximum number of in-vehicle devices that can be connected to the roadside machine at once. It is determined whether the connection is impossible because it is in the middle, and the result is output to the human interface user, and the control microcomputer is connected to the communication frame transmitted from the roadside device. If there is no slot allocation requesting a connection, or there is a slot requesting connection but the connection is restricted by the control field associated with that slot, the control field in which the broadcast link address is registered is When there is at least one slot for performing data transmission / reception with the associated roadside device, and there is no slot for performing data transmission / reception with the associated roadside device with the control field registered with the individual communication link address, The on-road unit will decide to only send broadcast data. There.

  In the on-vehicle device for narrow area communication according to the present invention, the user can perform accurate and lean communication.

Embodiment 1.
FIG. 1 is a block diagram of a vehicle-mounted device for narrow area communication according to Embodiment 1 of the present invention.
The on-vehicle device for narrow area communication 1 is connected to an antenna 2, an electric field strength measuring unit 3 that is connected to the antenna 2 and measures the electric field strength of a received radio wave from each road device (not shown), and the antenna 2. Wireless communication based on a built-in program connected to the wireless communication unit 4 that transmits and receives data and the like to and from roadside devices around the narrow-range communication vehicle-mounted device 1 and the electric field strength measurement unit 3 and the wireless communication unit 4 A control microcomputer 5 having a function of supplying a necessary control signal to the unit 4 and receiving a signal from the wireless communication unit 4 and the electric field strength measuring unit 3 and executing a predetermined application, and the control microcomputer 5 A human interface (HMI) 6 is provided. The human interface 6 is, for example, a display or a sound generator.

The electric field strength measuring unit 3 transmits the measured electric field strength from the roadside device to the control microcomputer 5, and when the control microcomputer 5 receives the electric field strength of a certain level or more, the signal is output to the HMI 6 as a result. At this time, the measurement result is output as measurement data as it is, or the measured electric field strength is output to the control microcomputer 5 in a plurality of stages so that it can be easily understood by the user such as strong, medium and weak.
From this result, the user can immediately grasp the reception state of the radio wave of the vehicle-mounted device, and can move the vehicle to an appropriate position for communication.

Embodiment 2.
FIG. 2 is a flowchart showing the operation of the vehicle-mounted device for narrow area communication according to Embodiment 2 of the present invention. The configuration of the on-vehicle device for narrow area communication is the same as that of the first embodiment shown in FIG.
When the vehicle-mounted device is activated (step S11), when the wireless communication unit 4 receives a signal, the control microcomputer 5 determines whether or not a timer for managing a certain period is activated (step S13) and is not activated. Starts a timer (step S14).
The wireless communication unit 4 determines whether or not the received signal is a slot for controlling a communication frame (step S15), and transmits the result and data to the control microcomputer 5. When the received signal is a slot for controlling a communication frame, the control microcomputer 5 determines whether or not the data format matches the data format defined in the protocol of the narrow area communication system (step S16). Whether the reception is normal or not is determined based on whether or not it matches the protocol of the regional communication system.

  When the received signal is a slot for controlling a communication frame, the control microcomputer 5 counts the number of times of normal reception and not normal reception for a certain period (step S19) from that point (steps S17 and S18). After a certain period, the timer is ended and the counter is reset (step S20). The ratio of the number of normal receptions is calculated from the total number of receptions from the data counted for a certain period (step S21). In consideration of the case where the slot data for controlling the communication frame received by the antenna 2 is not determined as the slot for controlling the communication frame in the wireless communication unit 4 during the fixed period of counting, the slot for originally controlling the communication frame is determined. It may be included in the total number of receptions at the reception timing. The control microcomputer 5 causes the HIM 6 to output the calculated ratio result of the number of times of normal reception (step S22).

  From this result, the user can immediately grasp the data reception state of the vehicle-mounted device, and can move the vehicle to a position where transmission and reception can be performed with a higher normal reception rate in communication.

Embodiment 3 FIG.
FIG. 3 is a flowchart showing the operation of the vehicle-mounted device for narrow area communication according to Embodiment 3 of the present invention. The configuration of the on-vehicle device for narrow area communication is the same as that of the first embodiment shown in FIG.
In this embodiment, when the connection at the initial connection is impossible, the user is immediately notified through the HMI 6 whether the connection between the vehicle-mounted device and the road device is not established, or whether the road device is a road device that can communicate. Is.
When the road device and the vehicle-mounted device are not connected in the initial state and cannot be connected (step S31), the control microcomputer 5 first has a communication profile or mounted between the road device and the vehicle-mounted device. It is determined whether the application is different (step S32). At this time, if the communication profile or installed application is different between the roadside device and the vehicle-mounted device, the vehicle-mounted device cannot communicate with the roadside device. The user is notified through the HMI 6 (step S35).
If there is a matching combination of the communication profile and application between the road device and the vehicle-mounted device, and there is no problem in connection, the control microcomputer 5 only transmits the broadcast data next by the road device. It is determined whether it is a road machine to perform (step S33).
If the road device is a road device that only transmits broadcast data, the user is notified through the HMI 6 that the road device cannot perform individual communication (step S37).
If the road device is not a road device that only transmits broadcast data, the control microcomputer 5 next determines whether or not the road device is connected to the maximum number of vehicle-mounted devices that can be connected at one time (step). S34). If the road unit is not connected to the maximum number of on-board units that can be connected at once, the road unit is regarded as abnormal, and the user is notified through the HMI 6 that communication with the road unit cannot be performed (step S35). . When the road unit is connected to the maximum number of OBEs that can be connected at once, communication is possible when one of the connected OBEs disconnects communication. The user is notified through the HMI 6 that the device is a machine (step S36).

  As described above, the user can connect to the roadside device that cannot be connected even after a while because the roadside device to be connected is a roadside device that only transmits a communication profile or application or broadcast data. It can be immediately recognized at the initial connection between the road device and the vehicle-mounted device whether it is connected to the maximum number of vehicle-mounted devices and can be connected with time.

FIG. 4 shows the type of road equipment as a judgment criterion in order to notify the user whether the connection between the vehicle-mounted device and the road equipment is not established or whether the road equipment is communicable on the initial connection. It is a flowchart for discriminating.
When the connection between the road device and the vehicle-mounted device is not established in the initial state (step S41), the control microcomputer 5 checks whether there is a slot for requesting connection on the communication frame (step S42).
If there is a slot for requesting connection, it is checked whether the connection is restricted in the control field associated with the slot (step S43). If there is a slot for requesting connection on the communication frame and the connection is not restricted in the control field of that slot, the signal transmitted by the vehicle-mounted device cannot be received by the road unit in that communication slot. Therefore, the in-vehicle device continues to request connection.

  When the road unit is connected to the maximum number of on-board units that can be connected to the on-board unit, the allocation of the slot that requests connection is interrupted, or the connection is limited by the control field of the slot that requires connection. At this time, if a vehicle-mounted device being connected disconnects, another vehicle-mounted device can be connected. Therefore, when there is no slot for requesting connection on the communication frame, or when the connection is restricted by the control field of the slot for requesting connection, a link address for individual communication different from the on-vehicle device is set on the communication frame. It is checked whether there is a normal or priority data transmission / reception slot (step S44). At this time, if there is a normal or priority data transmission / reception slot for the individual communication link address, it can be determined that the road unit is capable of individual communication. Therefore, in the above case, it is determined that the road device is a connectable road device (step S45).

  When there is no slot for requesting connection on the communication frame, or when the connection is restricted by the control field of the slot for requesting connection, and the link address for individual communication different from the OBE on the communication frame. If there is no normal or priority data transmission / reception slot, the control microcomputer 5 checks whether there is a data transmission / reception slot of the broadcast link address (step S46). A roadside device that only transmits broadcast data does not perform individual communication. Therefore, a slot for requesting connection is not necessary and a slot for requesting connection is not allocated. Therefore, the control microcomputer 5 does not have a slot for requesting connection on the communication frame or the connection is restricted by the control field of the slot for requesting connection, and is used for individual communication on the communication frame. When there is no normal or priority data transmission / reception slot for the link address and there is a data transmission / reception slot for the broadcast link address, it can be determined that the roadside machine only transmits broadcast data (step S47). .

  In addition, when there is no normal or priority data transmission / reception slot of the individual communication link address different from that of the vehicle-mounted device and the data transmission / reception slot of the broadcast link address on the communication frame, a connection is requested on the communication frame. If the slot is not allocated or the connection is restricted by the control field of the slot that requires connection, there is a problem in the system of the road machine. Therefore, the control microcomputer 5 is not the road machine. It is determined that the connection cannot be made (step S48).

Embodiment 4.
FIG. 5 is a flowchart showing the operation of the vehicle-mounted device for narrow area communication according to Embodiment 4 of the present invention. The configuration of the on-vehicle device for narrow area communication is the same as that of the first embodiment shown in FIG.
FIG. 6 is a flowchart showing means for providing communication traffic to a user. Here, it is assumed that the communication traffic is the number of connected vehicle-mounted devices. After starting up the OBE system, the timer, the number of connected roadside devices and the OBE list are initialized (steps S51 and S52). When a slot for controlling a communication frame is received (step S53), the timer is within a predetermined monitoring time. (Step S61) The number of other vehicle-mounted devices connected to the roadside device is counted, and the counted result is notified to the user (Step S62). From reception of the slot for controlling the communication frame to calculation of the number of connected units, steps S53 to S60 are performed during the monitoring time. First, the number of data transmission / reception slots is registered (step S54), and a variable for counting slots is initialized (step S55). A variable for counting the slots is added in order (step S56), and the data transmission / reception slots corresponding to the value are the same as the number of data transmission / reception slots, and the link address associated with normal or priority is the link address for individual communication. (Step S57) is repeatedly checked (step S57).
If the slot address is normal or preferred and the associated link address is an individual communication link address and the address is not registered in the OBE list, the link address is registered in the OBE list (step S58) and connected. The number is incremented (step S59). When the timer exceeds a predetermined time, the timer, the vehicle-mounted device list, and the number of connected devices are initialized (step S63).

  From the above, the user can always recognize the number of connected road devices.

Embodiment 5.
FIG. 6 is a flowchart showing the operation of the vehicle-mounted device for narrow area communication according to the fifth embodiment of the present invention. The configuration of the on-vehicle device for narrow area communication is the same as that of the first embodiment shown in FIG.
FIG. 6 is a flowchart showing the process until the maximum transfer capacity of the roadside device is calculated and the result is notified to the user. Here, the maximum transfer capability is the transfer rate per unit time.
When the control microcomputer 5 receives a slot for controlling a communication frame of a new roadside device after starting up the vehicle-mounted device system (step S71), the number of data transmission / reception slots per communication frame and per data transmission / reception slot The maximum transfer rate per unit time is calculated from the read value (step S72). Then, the calculated result is notified to the user through the HMI 6 (step S73).

  As described above, the user can immediately recognize the maximum transfer capability of the roadside device.

Embodiment 6.
FIG. 7 is a flowchart showing the operation of the vehicle-mounted device for narrow area communication according to Embodiment 6 of the present invention. The configuration of the on-vehicle device for narrow area communication is the same as that of the first embodiment shown in FIG.
FIG. 7 is a flowchart showing the process until the data transfer efficiency during communication is calculated and notified to the user.
The control microcomputer 5 initializes the amount of received data after starting up the system of the vehicle-mounted device (step S81), and stores the effective amount of data in the slot when the data transmission / reception slot is normally received (step S82). (Step S83). The accumulation of the data amount is performed within a certain time (step S84), and after the lapse of the certain time, the data transfer amount per unit time is calculated based on the accumulated data amount and the elapsed time (step S85). Then, the calculated result is notified to the user through the HMI 6 (step S86).
Although an example in which the transfer efficiency in data reception is calculated is shown here, the transfer efficiency in data transmission may be calculated.

As described above, the user can immediately recognize the data transfer efficiency in data transmission / reception during communication.

It is a block diagram which shows the vehicle-mounted device for narrow area communication of Embodiment 1 of this invention. It is a flowchart which shows operation | movement of the onboard equipment for narrow region communication of Embodiment 2 of this invention. It is a flowchart which shows operation | movement of the onboard equipment for narrow region communication of Embodiment 3 of this invention. It is a flowchart which shows operation | movement of the onboard equipment for narrow region communication of Embodiment 3 of this invention. It is a flowchart which shows operation | movement of the onboard equipment for narrow region communication of Embodiment 4 of this invention. It is a flowchart which shows operation | movement of the onboard equipment for narrow region communication of Embodiment 5 of this invention. It is a flowchart which shows operation | movement of the onboard equipment for narrow region communication of Embodiment 6 of this invention.

Explanation of symbols

  1 Narrow-range communication vehicle-mounted device, 2 antenna, 3 electric field strength measuring unit, 4 wireless communication unit, 5 control microcomputer, 6 HMI.

Claims (3)

An antenna that transmits and receives to / from a road device, a wireless communication unit that is connected to the antenna and transmits / receives to / from the road device via an antenna, and a wireless communication unit that is connected to and built in the wireless communication unit A control microcomputer that has a function of supplying a necessary control signal and receiving a signal from a wireless communication unit and executing a predetermined application, and a human interface connected to the control microcomputer,
When the control microcomputer cannot be connected to the road machine at the initial connection with the road machine, the control microcomputer is a combination that cannot be connected due to a difference in communication profile or application owned by the road machine, or the road machine has already been once It is determined whether it is impossible to connect because it is connected to the maximum number of on-board devices that can be connected to, and the result is output to the human interface user,
The control microcomputer, when there is no allocation of a slot for requesting connection in the communication frame transmitted from the roadside device, or there is a slot for requesting connection, but the connection is made in the control field associated with the slot. In the case of restriction, there is at least one slot for transmitting / receiving data to / from the roadside equipment accompanied by the control field in which the broadcast link address is registered, and the control in which the individual communication link address is registered. If the field is a slot to perform data transmission and reception with the accompanying been road equipment does not exist, the road device is mounted device for short range communication that have adapted to determine and perform only transmitting the broadcast data. An antenna that transmits and receives to / from a road device, a wireless communication unit that is connected to the antenna and transmits / receives to / from the road device via an antenna, and a wireless communication unit that is connected to and built in the wireless communication unit A control microcomputer that has a function of supplying a necessary control signal and receiving a signal from a wireless communication unit and executing a predetermined application, and a human interface connected to the control microcomputer,
When the control microcomputer cannot be connected to the road machine at the initial connection with the road machine, the control microcomputer is a combination that cannot be connected due to a difference in communication profile or application owned by the road machine, or the road machine has already been once It is determined whether it is impossible to connect because it is connected to the maximum number of on-board devices that can be connected to, and the result is output to the human interface user,
The control microcomputer, when there is no allocation of a slot for requesting connection in the communication frame transmitted from the roadside device, or there is a slot for requesting connection, but the connection is made in the control field associated with the slot. In the case of restriction, if there is at least one slot for transmitting / receiving data to / from a roadside device accompanied by a control field in which the individual communication link address is registered, an individual communication link address in the slot is selected. OBE is narrow area OBE communication that have adapted to determine a possible new connection at the time of cutting the connection with. An antenna that transmits and receives to / from a road device, a wireless communication unit that is connected to the antenna and transmits / receives to / from the road device via an antenna, and a wireless communication unit that is connected to and built in the wireless communication unit A control microcomputer that has a function of supplying a necessary control signal and receiving a signal from a wireless communication unit and executing a predetermined application, and a human interface connected to the control microcomputer,
When the control microcomputer cannot be connected to the road machine at the initial connection with the road machine, the control microcomputer is a combination that cannot be connected due to a difference in communication profile or application owned by the road machine, or the road machine has already been once It is determined whether it is impossible to connect because it is connected to the maximum number of on-board devices that can be connected to, and the result is output to the human interface user,
The control microcomputer restricts connection by a control field associated with the slot when there is no slot allocation requesting connection in the communication frame transmitted from the roadside device or when there is a slot requesting connection. In this case, all slots are configured as slots for transmitting / receiving data to / from road units set as idle channels or idle channels, or slots for transmitting / receiving identification codes as unique devices. If narrow area OBE communication that looks like determines that it is unable to connect with the roadside device.

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