JP2013009027A - Pedestrian terminal device, computer program, and radio communication method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively use a band for radio communication.SOLUTION: A pedestrian terminal device 1 is able to obtain positional information indicating a current location. The pedestrian terminal device 1 includes a communication unit 6 which can wirelessly transmit the positional information, and receives the positional information indicating the location of an on-vehicle device 8 transmitted by another radio communication device which is the on-vehicle device 8 in this case. An information acquisition unit 22 of the pedestrian terminal device 1 acquires relative positional information on a relative position of the on-vehicle device 8 to its own device on the basis of the positional information of the on-vehicle device 8 and the positional information of its own device. A communication control unit 21 of the pedestrian terminal device 1 performs control such as control of continuation, interruption, or an increase or a decrease in a transmission frequency of radio transmission by the communication unit 6 on the basis of the relative positional information acquired by the information acquisition unit 22.

Description

  The present invention relates to, for example, a pedestrian terminal device used for an intelligent transport system (ITS), a computer program for the pedestrian terminal device, and a wireless communication method executed by the pedestrian terminal device. About.

In order to promote traffic safety and prevent traffic accidents, advanced road traffic systems that receive information from infrastructure equipment installed on the road and use this information to improve vehicle safety are being studied. (For example, refer to Patent Document 1).
Such an intelligent road traffic system is mainly composed of a plurality of roadside devices that are wireless communication devices on the infrastructure side and a plurality of in-vehicle devices that are wireless communication devices mounted on a vehicle.

  In this case, the combination of communication performed between the communication subjects includes road-to-vehicle (or vehicle-road) communication performed by the roadside device and the vehicle-mounted device and vehicle-to-vehicle communication performed by the vehicle-mounted devices.

Japanese Patent No. 2806801

  In recent years, for the purpose of preventing traffic accidents between pedestrians and vehicles, terminal devices possessed by pedestrians (hereinafter referred to as pedestrian terminal devices) and in-vehicle devices perform wireless communication (communication between pedestrians). Has been proposed that transmits information indicating its own location and information indicating that the other party is nearby. That is, the in-vehicle device transmits position information indicating its own position, and this is received by the pedestrian terminal device. In addition, the pedestrian terminal device also transmits position information indicating its own position, The in-vehicle device receives it.

  In such inter-vehicle communication, it is conceivable to perform communication using CSMA (Carrier Sense Multiple Access) according to the communication procedure of inter-vehicle communication. However, in this case, as pedestrian terminal devices become widespread, especially in places where pedestrians gather, such as intersections, the number of pedestrian terminal devices increases, and when they try to start transmitting information for their own convenience, It is conceivable that the band of wireless communication becomes tight and the opportunity of information transmission by the in-vehicle device is taken away. As a result, there is a possibility that the purpose of preventing a traffic accident between a pedestrian and a vehicle by performing inter-pedal communication cannot be achieved.

  Accordingly, an object of the present invention is to provide a pedestrian terminal device capable of effectively using a wireless communication band, a computer program for the pedestrian terminal device, and wireless communication executed by the pedestrian terminal device. Provide a method.

(1) The present invention is a pedestrian terminal device capable of acquiring position information indicating a current position, wherein the position information can be wirelessly transmitted, and the other wireless communication device transmitted from another wireless communication device Relative position information on the relative position between the other wireless communication device and itself based on the communication unit that receives the position information indicating the position of the other wireless communication device, and the position information of the other wireless communication device and its own position information And a communication control unit that controls wireless transmission by the communication unit based on the relative position information acquired by the acquisition unit.

  According to the present invention, wireless transmission by a pedestrian terminal device is controlled based on relative position information regarding the relative position between another wireless communication device and itself. In other words, depending on the environment in which the pedestrian terminal device is used in relation to other wireless communication devices, control on continuation, interruption or increase / decrease of transmission frequency of the wireless transmission by the pedestrian terminal device Is done. For this reason, for example, when the pedestrian terminal device is used in an environment where the pedestrian terminal device moves together with another wireless communication device, the wireless communication by the other wireless communication device is refrained from wireless transmission by the pedestrian terminal device. Can be prioritized and the wireless communication band can be used effectively.

(2) Moreover, it is preferable that the said communication part can perform radio | wireless communication between the vehicle equipment which is said other radio | wireless communication apparatus which exists in the circumference | surroundings.
In this case, when the surrounding in-vehicle device receives the information wirelessly transmitted by the pedestrian terminal device, the presence of the pedestrian terminal device is recognized on the vehicle side on which the in-vehicle device is mounted, and the vehicle travels safely. It can be useful.

(3) Moreover, the said pedestrian terminal device determines whether the said other radio | wireless communication apparatus is a vehicle-mounted apparatus based on the information transmitted from the said other radio | wireless communication apparatus and the said communication part received. The relative position information indicating that the fluctuation of the relative position between itself and another wireless communication device determined to be an in-vehicle device by the determination unit is small over a predetermined time. When acquired by the unit, the communication control unit preferably executes control for interrupting the radio transmission by the communication unit or reducing the transmission frequency.
When relative position information indicating that a change in relative position between another wireless communication device determined to be an in-vehicle device by the determination unit and the pedestrian terminal device (self) is small over a predetermined time is acquired It is considered that a pedestrian terminal device (self) is also on a vehicle on which the other wireless communication device (on-vehicle device) is mounted. Therefore, in this case, the pedestrian terminal device (self) gives priority to wireless communication by another wireless communication device (on-vehicle device) by interrupting wireless transmission or reducing the transmission frequency.

(4) The pedestrian terminal device determines whether each of the plurality of other wireless communication devices is an in-vehicle device based on information transmitted from the other wireless communication devices and received by the communication unit. And a determination unit that determines whether a plurality of other wireless communication devices that are communication partners are not on-vehicle devices, and the acquisition unit is a communication partner. When the relative position information indicating that the relative position variation between each of the plurality of other wireless communication devices and itself is small over a predetermined time is acquired, the communication control unit performs wireless transmission by the communication unit. It is preferable to execute control to reduce interruption or transmission frequency.
A plurality of other wireless communication devices that are communication partners are not on-vehicle devices, and the relative position variation between each of the plurality of other wireless communication devices and the pedestrian terminal device (self) is small over a predetermined time. When the relative position information indicating is acquired, the plurality of other wireless communication devices that are communication partners are also pedestrian terminal devices, including themselves, on the same vehicle (for example, a bus) It is thought that there is. Therefore, in this case, the pedestrian terminal device (self) gives priority to wireless communication by another wireless communication device (other pedestrian terminal device) by interrupting wireless transmission or reducing the transmission frequency.

(5) Moreover, the pedestrian terminal device further includes a detection unit that detects that the terminal holder is not in a walking state where the terminal holder is walking, but is in a traveling state where the terminal holder is moving on a vehicle. And the detection unit detects that the vehicle is in the traveling state, and the acquisition unit has a large relative position variation between each of the plurality of other wireless communication devices that are communication partners. When the relative position information indicating this is acquired, it is preferable that the communication control unit performs control to continue the radio transmission by the communication unit or increase the transmission frequency.
Relative indicating that the terminal holder is traveling while riding on a vehicle, and that the relative position variation between each of a plurality of other wireless communication devices that are communication partners is large. When the position information is acquired, there are a plurality of wireless communication devices around as a communication partner, but it is considered that they are not on the vehicle (bus) on which they are riding. In this case, since the pedestrian terminal device (self) is the only device having a wireless communication function in the vehicle (bus), the pedestrian terminal device (self) functions as an in-vehicle device. Therefore, active wireless transmission can be performed. The terminal owner is a person who has a pedestrian terminal device.

(6) In addition, the communication unit receives movement information indicating one or both of a movement speed and a movement direction of the other wireless communication device together with the position information of the other wireless communication device, and acquires the information. The unit preferably acquires the relative position information by using the movement information as an auxiliary.
As described above, the acquisition of the relative position information by the acquisition unit is based on the relative position between the other wireless communication device and itself, but by using the movement information as a supplement, the relative position regarding the relative position is obtained. The accuracy of information increases. For this reason, it is possible to accurately control wireless transmission by the communication control unit.

  (7) Further, the present invention is a computer program for causing a computer to function as a pedestrian terminal device that includes a processing unit that performs various processes including control of wireless transmission and that can acquire position information indicating a current position. And receiving the position information indicating the position of the other wireless communication device transmitted from the other wireless communication device, and the position information of the other wireless communication device and the position information of the other wireless communication device. A step of acquiring relative position information relating to a relative position between the wireless communication apparatus and the wireless communication apparatus, and a step of controlling the wireless transmission based on the acquired relative position information.

  According to the present invention, wireless transmission by a pedestrian terminal device is controlled based on relative position information regarding the relative position between another wireless communication device and itself. In other words, depending on the environment in which the pedestrian terminal device is used in relation to other wireless communication devices, control on continuation, interruption or increase / decrease of transmission frequency of the wireless transmission by the pedestrian terminal device Is done. For this reason, for example, when the pedestrian terminal device is used in an environment where the pedestrian terminal device moves together with another wireless communication device, the wireless communication by the other wireless communication device is refrained from wireless transmission by the pedestrian terminal device. Can be prioritized and the wireless communication band can be used effectively.

  (8) Moreover, this invention is a radio | wireless communication method performed by the pedestrian terminal device which is provided with the process part which performs various processes including control of radio | wireless transmission, and can acquire the positional information which shows a present position, Receiving the position information indicating the position of the other wireless communication device transmitted from the other wireless communication device, and based on the position information of the other wireless communication device and the position information of the other wireless communication device, Relative position information relating to a position relative to itself is acquired, and the wireless transmission is controlled based on the acquired relative position information.

  According to the present invention, wireless transmission by a pedestrian terminal device is controlled based on relative position information regarding the relative position between another wireless communication device and itself. In other words, depending on the environment in which the pedestrian terminal device is used in relation to other wireless communication devices, control on continuation, interruption or increase / decrease of transmission frequency of the wireless transmission by the pedestrian terminal device Is done. For this reason, for example, when the pedestrian terminal device is used in an environment where the pedestrian terminal device moves together with another wireless communication device, the wireless communication by the other wireless communication device is refrained from wireless transmission by the pedestrian terminal device. Can be prioritized and the wireless communication band can be used effectively.

  According to the present invention, the wireless transmission by the pedestrian terminal device is controlled according to what environment the pedestrian terminal device is used in relation to other wireless communication devices. Depending on the use environment of the device, for example, the wireless transmission by the pedestrian terminal device can be refrained, and the wireless communication by another wireless communication device can be prioritized, and the wireless communication band can be used effectively. .

It is the schematic which shows the whole structure of an intelligent road traffic system (ITS). It is a block diagram which shows one Embodiment of a roadside apparatus and a vehicle-mounted apparatus. It is a block diagram which shows one Embodiment of a pedestrian terminal device. It is a flowchart explaining a radio | wireless communication method (1st Embodiment). It is a figure which shows a part of FIG. 1, and the holder who has the pedestrian terminal device has shown the state which has got on the vehicle carrying the vehicle-mounted apparatus. It is a flowchart explaining a radio | wireless communication method (2nd Embodiment). It is a figure which shows a part of FIG. 1, and has shown the state in which the holder who has the pedestrian terminal device is on the bus | bath which is not carrying in-vehicle apparatus. It is a figure which shows a part of FIG. 1, and the one pedestrian terminal device is on the bus | bath, and the other pedestrian terminal device of the circumference | surroundings has shown the state which is not on this bus | bath.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[Overall system configuration]
FIG. 1 is a schematic diagram showing the overall configuration of an intelligent road traffic system (ITS). This intelligent road traffic system includes a traffic signal 13, a roadside device 10 that is a wireless communication device, an in-vehicle device 8 that is a wireless communication device, a vehicle 41 equipped with the in-vehicle device 8, and a pedestrian H who is a wireless communication device. A person terminal device 1 and a central device 9 are included.

  The traffic signal 13 and the roadside apparatus 10 are installed at each of a plurality of intersections Ji (i = 1 to 12 in the figure). The roadside apparatus 10 installed at each intersection can communicate with the signal controller 12 that controls the traffic signal apparatus 13 installed at the intersection. The signal controller 12 controls the change of the light color of the traffic signal 13.

The central device 9 constitutes a local area network (LAN) with the traffic signal device 13 (signal controller 12) and the roadside device 10 at the intersection Ji included in the area under its control.
The central device 9 has a control unit composed of a workstation (WS), a personal computer (PC), etc., and this control unit collects, processes (calculates) and records various traffic information from the roadside device 10. , Signal control and information provision.

Each roadside device 10 has a communication area extending around it, and between the vehicle-mounted device 8 of the vehicle 41 traveling in its own communication area and between the pedestrian terminal device 1 in the communication area. Perform wireless communication.
Each in-vehicle device 8 moves because it is mounted on the vehicle 41, but forms a communication area extending around the vehicle device 8, and wireless communication is possible with the pedestrian terminal device 1 in its own communication area. Further, the in-vehicle device 8 can wirelessly communicate with other in-vehicle devices 8 in a state where communication areas overlap.
That is, in the intelligent transportation system of the present embodiment, road-to-vehicle (or road) communication performed by the roadside device 10 and the vehicle-mounted device 8, vehicle-vehicle communication performed by the vehicle-mounted devices 8 and the pedestrian terminal device 1 And communication between the pedestrians (or road walks) performed by the roadside device 10 and communication between the pedestrians (or vehicle walks) performed by the pedestrian terminal device 1 and the in-vehicle device 8 are included.

[About in-vehicle devices]
FIG. 2 is a block diagram showing the roadside device 10 and the in-vehicle device 8. In addition, the block diagram of the pedestrian terminal device 1 is shown in FIG.
In FIG. 2, an in-vehicle device 8 includes a communication unit 72 connected to an antenna 71 for wireless communication, a control unit 73 including a processor (CPU: Central Processing Unit) that performs communication control on the communication unit 72, and the like. A storage unit 74 including a storage device such as a ROM or a RAM connected to the control unit 73 is provided.

The storage unit 74 stores a computer program for communication control executed by the control unit 73, identification information (in-vehicle device ID) for identifying the in-vehicle device (self) 8, and the in-vehicle device (self) 8. The identification information (vehicle ID) for identifying the vehicle on which the vehicle is mounted is stored.
And the control part 73 performs radio | wireless communication using CSMA (Carrier Sense Multiple Access) as a communication procedure. That is, the control unit 73 causes the communication unit 72 to perform wireless communication based on the carrier sense method for inter-vehicle communication and inter-pedal communication.
For this reason, the communication unit 72 always senses the reception level of a predetermined carrier frequency, and does not perform wireless transmission when the value is equal to or higher than a certain threshold, and performs wireless transmission only when the value is less than the threshold. I do.

  Furthermore, the in-vehicle device 8 includes a position acquisition unit 75 that acquires position information indicating its current position. The position acquisition unit 75 has, for example, a GPS positioning unit, and the GPS positioning unit receives radio waves from GPS satellites and measures its current position. In addition, the position acquisition unit 75 includes an azimuth sensor and an acceleration sensor, and can detect a movement direction, a movement speed, and a movement distance based on outputs from these sensors.

Each in-vehicle device 8 wirelessly transmits vehicle information including position information indicating the current position of the measured position and vehicle information including the detected movement speed and movement direction to the outside via the communication unit 72. ing. The vehicle information includes the vehicle ID, and may also include the in-vehicle device ID.
This vehicle information is received by the roadside device 10 and the pedestrian terminal device 1, and the pedestrian terminal device 1 executes various processes described later based on this vehicle information.

[About roadside equipment]
The roadside device 10 includes a wireless communication unit 62 to which an antenna 61 for wireless communication is connected, a wired communication unit 63 that performs bidirectional communication with the central device 9 and the signal controller 12, and a processor that performs communication control thereof. And a storage unit 65 including a storage device such as a ROM or a RAM connected to the control unit 64.

  The storage unit 65 of the roadside device 10 can temporarily store the vehicle information of the in-vehicle device 8 received by the wireless communication unit 62, and broadcast this information to the surroundings via the wireless communication unit 62. It has a function. That is, the vehicle information may be given directly to the pedestrian terminal device 1 from the in-vehicle device 8, but may be given to the pedestrian terminal device 1 via the roadside device 10.

[About pedestrian terminal devices]
The pedestrian terminal device 1 is a device possessed by a pedestrian, measures the position of the terminal owner (the pedestrian who owns the pedestrian terminal device 1), and is based on position information obtained by positioning. It is possible to estimate its own position (current position) on the map. Moreover, this pedestrian terminal device 1 can display its own position (that is, the walking position of the terminal owner) and a road map around it, and carries this display with the pedestrian terminal device 1. The pedestrian can be guided by seeing the pedestrian.
Furthermore, this pedestrian terminal device 1 also has a function of searching for a walking route from the position of the device itself to the destination. And the pedestrian terminal device 1 can guide a pedestrian by alert | reporting the searched walking route with respect to the pedestrian who is carrying the said pedestrian terminal device 1 at the time of a walk. In the following, when a pedestrian (terminal owner) who has the pedestrian terminal device 1 gets on the vehicle, the pedestrian is also referred to as the owner.

  In FIG. 3, a pedestrian terminal device 1 includes a central processing unit 2 that executes various processes, an input unit 3 that is operated by a pedestrian to input information, and measures its own position (current position) to determine the position. Wirelessly between the position acquisition unit 4 that acquires the position information to be shown, the storage device 5 in which map information (map data) and a computer program are stored, the communication unit 72 of the in-vehicle device 8 and the communication unit 62 of the roadside device 10. The communication part 6 which performs communication, and the output part 7 which outputs various information with respect to a pedestrian are provided.

  A pedestrian terminal device 1 according to the present embodiment includes a mobile phone (smart phone) having a function as a computer, and the mobile phone includes the central processing unit 2 that performs various processes including control of wireless communication. A computer program for functioning is configured by being installed in a mobile phone. Note that the pedestrian terminal device 1 may be a portable navigation device having a function as a computer.

Each of the below-described functional units included in the central processing unit 2 is exhibited when the computer program is executed by the central processing unit 2. That is, this computer program is for causing a mobile phone (smart phone) having a function as a computer to function as the pedestrian terminal device 1.
The computer program can be sold and transferred by being downloaded to the pedestrian terminal device 1 from a server in which the computer program is stored so as to be downloadable via a network. The computer program may be stored in a recording medium such as a CD-ROM or DVD-ROM, and sold or transferred. Each functional unit of the central processing unit 2 will be described later.

  The output unit 7 includes a display 7a and a speaker 7b. The display 7a outputs various information such as information on route guidance and presence information indicating that the in-vehicle device 8 (vehicle) is nearby as an image. To do. The speaker 7b outputs information on route guidance, the presence information, and the like as sound.

  The input unit 3 includes an operation device that functions as a user interface for a pedestrian. In the present embodiment, the input unit 3 is a touch panel device using the display 7a. When the pedestrian operates the input unit 3, various information such as a destination for searching for a walking route is input to the central processing unit 2 through the input unit 3. The input unit 3 may be a button provided separately from the display 7a (touch panel device).

  The position acquisition unit 4 includes, for example, a GPS positioning unit. The GPS positioning unit receives radio waves from GPS satellites and measures its current position. Further, the position acquisition unit 4 includes an azimuth sensor and an acceleration sensor, and can also detect a movement direction, a movement speed, and a movement distance based on the outputs of these sensors. And the position of the self based on a self-contained navigation is possible by the output of these sensors. Further, the position acquisition unit 4 gives the central processing unit 2 position information indicating the acquired position.

The storage device 5 includes a memory such as a ROM, a RAM, and a hard disk, and stores map information and the like in addition to the computer program.
Based on the current position acquired by the position acquisition unit 4 (the position information), the current position and the surrounding map (map information) are displayed on the display 7a, and route guidance is provided to the pedestrian. .

  The communication unit 6 has a narrow-area communication function for performing wireless communication with the in-vehicle device 8 (the communication unit 72) that is a surrounding wireless communication device. Furthermore, this narrow area communication function also has a function of performing communication between the roadside device 10 (the communication unit 62), which is a surrounding wireless communication device, and other surrounding pedestrian terminal devices 1. . This narrow area communication function is a communication function using a frequency band used for inter-vehicle communication communicating with the in-vehicle device 8 and inter-step communication communicating with the roadside device 10 as a road traffic information communication system.

Thereby, the communication part 6 can receive the information transmitted from the vehicle-mounted apparatus 8, the pedestrian terminal device 1, and the roadside apparatus 10 which are other radio | wireless communication apparatuses, and transmits information with respect to these. be able to. For example, the communication unit 6 can receive transmission information including position information indicating the position of the in-vehicle device 8 transmitted from the in-vehicle device 8 which is another wireless communication device. Since the position acquisition unit 4 has acquired its own position information, the communication unit 6 can wirelessly transmit its own position information to the surroundings.
In addition, when the pedestrian terminal device 1 is a mobile phone (smartphone), the communication unit 6 also has a wide area communication function for causing it to function as a mobile phone, and other wireless communication is performed using this wide area communication function. Information from the device may be received.

[About each functional unit of the central processing unit 2]
In FIG. 3, the central processing unit 2 includes a communication control unit 21, an information acquisition unit 22, a determination unit 23, and a detection unit 24 as functional units.

  The information acquisition unit 22 obtains relative position information regarding the relative position between the other wireless communication device and itself based on the position information of the other wireless communication devices existing in the vicinity and the position information of the information acquisition unit 22. get. For example, since the in-vehicle device 8 mounted on a vehicle traveling around transmits vehicle information including position information indicating the current position of the in-vehicle device 8 as described above, the vehicle information is If the communication part 6 receives, the information acquisition part 22 will acquire the relative position information regarding the relative position of the said vehicle-mounted apparatus 8 and self based on this vehicle information. The own position information is information acquired by the position acquisition unit 4.

  As for the relative position information, for example, even if a predetermined time elapses with respect to the relative position between the in-vehicle device 8 that has transmitted the vehicle information including the position information and itself, the relative position variation is small ( Or information indicating that the variation is large).

Moreover, as above-mentioned, the vehicle-mounted apparatus 8 has also transmitted the movement information which shows a moving speed and a moving direction in vehicle information with the position information. Therefore, the communication unit 6 can receive vehicle information including movement information indicating one or both of the movement speed and the movement direction of the vehicle-mounted device 8 together with the position information of the vehicle-mounted device 8.
Then, the information acquisition unit 22 may acquire the relative position information by using the acquired movement information as an auxiliary. In this case, the acquisition of the relative position information by the information acquisition unit 22 is based on the relative position between the in-vehicle device 8 and itself, but by using the movement information as a supplement, the relative position information regarding the relative position is obtained. Accuracy can be increased.

The communication control unit 21 performs wireless communication using CSMA (Carrier Sense Multiple Access) as a communication procedure. That is, the communication control unit 21 causes the communication unit 6 to perform wireless communication based on the carrier sense method for inter-vehicle communication.
For this reason, the communication control unit 21 constantly senses the reception level of a predetermined carrier frequency, and in a normal state (that is, except when the below-described restriction control is executed), the value is equal to or greater than a certain threshold value. In this case, wireless transmission is not performed, and wireless transmission is performed only when the threshold is less than the threshold value.

The communication control unit 21 controls wireless transmission by the communication unit 6 based on the relative position information acquired by the information acquisition unit 22. As control of wireless transmission, there is control for continuing wireless transmission by the communication unit 6 or increasing the transmission frequency, in addition to restriction control for interrupting wireless transmission by the communication unit 6 or reducing the transmission frequency. A specific example of communication control by the communication control unit 21 will be described by a wireless communication method executed by the pedestrian terminal device 1 described later.
Information transmitted to the surroundings by the wireless transmission performed by the pedestrian terminal device 1 includes position information of the pedestrian terminal device 1 (self).

The determination unit 23 has a function of determining whether another wireless communication device that is a communication partner is an in-vehicle device based on transmission information that is transmitted from other wireless communication devices around and received by the communication unit 6. have.
For example, since the transmission information transmitted by the surrounding in-vehicle device 8 is vehicle information including the vehicle ID as described above, when the communication unit 6 receives this transmission information (vehicle information), the determination unit 23 It can be determined whether or not the vehicle information is included in the transmission information. Since the vehicle ID is defined in a predetermined format, the determination unit 23 determines whether or not the vehicle ID is included in the transmission information based on the transmission information transmitted from the communication partner, that is, communication. It can be determined whether or not the partner wireless communication device is an in-vehicle device.

When there are a plurality of other wireless communication devices around the pedestrian terminal device 1, the pedestrian terminal device 1 receives transmission information from each of these wireless communication devices. Therefore, the determination unit 23 determines whether each of the plurality of other wireless communication devices is an in-vehicle device based on transmission information transmitted from the plurality of other wireless communication devices and received by the communication unit 6. Can do. For example, if a vehicle ID is included in the transmission information, it is determined that the wireless communication device that is the communication counterpart is an in-vehicle device in association with each vehicle ID.
The determination as to whether or not the vehicle is an in-vehicle device may be based on information other than the vehicle ID, or may be performed based on vehicle information unique to the vehicle (for example, information related to the operation of the blinker).

  The detection unit 24 is not in a walking state where the terminal holder who owns the pedestrian terminal device 1 (self) is walking, but the terminal owner who owns the pedestrian terminal device 1 (self) moves on the vehicle. It has a function to detect that it is a running state. That is, the detection unit 24 can determine whether the terminal owner is walking or moving on a vehicle (vehicle).

  Since the pedestrian terminal device 1 has an acceleration sensor, the detection unit 24 determines the presence / absence of a walking feature based on a detection signal from the sensor and combines the movement speed (or acceleration). It is possible to determine whether the person is walking or riding a vehicle. For example, if the moving speed is fast but it is determined that the vehicle is stationary based on the walking feature, it is determined that the possibility of riding on the vehicle is high. The processing by the detection unit 24 may use other means.

In this way, if the moving speed is fast but it is determined that the vehicle is stationary based on walking characteristics, it is determined that the vehicle is likely to be on the vehicle. The detection unit 24 can also determine the type of vehicle such as
That is, although not shown, a cradle for mounting the pedestrian terminal device 1 is provided for each vehicle, and the characteristics (shape) of the mounting portion of the cradle are changed depending on the type of vehicle. And on the pedestrian terminal device 1 side, it is comprised so that the signal line supplied with electricity may change with the difference in this characteristic. By this change in the signal line, the detection unit 24 can determine the type.
Alternatively, the characteristics of the mounting portion of the cradle are the same for each type of vehicle, but the first signal line for identifying whether or not the vehicle is mounted and the second signal line for determining the type include the cradle and the pedestrian terminal device 1. The type may be determined based on the signal of the second signal line. For example, if there is a signal on the first signal line and it can be determined that it is worn, but if there is no signal on the second signal line, it can be determined that the bicycle is a bicycle.
Alternatively, whether or not the user has boarded a bus or a train may be determined based on whether or not electronic payment performed when getting on and off the transportation means using the pedestrian terminal device 1 is executed.
In particular, when taking a train, it is considered that the position of the pedestrian is not on the normal road or building but on the track, so the detected position of the pedestrian terminal device 1 is on the train line. If it is determined, it may be recognized that the user is on the train.

  In addition, although the pedestrian terminal device 1 is on the vehicle, the pedestrian terminal device 1 may function as an in-vehicle device. Therefore, although not shown, the detection unit 24 may detect whether or not the pedestrian terminal device 1 is functioning as an in-vehicle device based on the attachment of the pedestrian terminal device 1 to a cradle mounted on the vehicle. it can. For example, when the detection unit 24 determines that the pedestrian terminal device 1 is supplied with power from the vehicle-side battery (external power source) through the cradle, the vehicle uses the pedestrian terminal device 1 as an in-vehicle device. It can be determined that In this case, the communication control unit 21 transmits information according to a communication procedure by CSMA if there is a transmission opportunity.

[First Embodiment of Wireless Communication Method]
A wireless communication method executed by the pedestrian terminal device 1 having the above configuration will be described.
FIG. 4 is a flowchart illustrating the wireless communication method. FIG. 5 is a diagram illustrating a part of FIG. 1, and it is assumed that the terminal owner is on a vehicle 41-1 on which the in-vehicle device 8-1 is mounted. The vehicle 41-1 is traveling toward the intersection J4, and the traffic signal 13, the signal controller 12, and the roadside device 10 are installed at the intersection J4. Furthermore, another vehicle 41-2 exists in the vicinity of the intersection J4, and the vehicle-mounted device 8-2 is mounted on the vehicle 41-2. Each of the in-vehicle devices 8-1 and 8-2 has the above-described configuration.

  A wireless communication method executed by the pedestrian terminal device 1 riding on the vehicle 41-1 will be described. The detection unit 24 of the pedestrian terminal device 1 determines whether the terminal holder is walking (walking state) or moving on a vehicle (vehicle) (running state) (step S1). This determination means is as described above, and the description thereof is omitted here. In the present embodiment, the detection unit 24 detects that the terminal holder is not in a walking state but in a traveling state on the vehicle 41-1 (Yes in step S1).

  And the position acquisition part 4 of the pedestrian terminal device 1 acquires the positional information which shows own present position (step S11 of FIG. 4). The acquisition of the position information is repeatedly executed, and continues to be acquired while updating information about the current position that changes every moment, and new position information is given to the central processing unit 2.

  Further, the communication unit 6 receives transmission information transmitted from other wireless communication apparatuses existing in the vicinity (step S2). This transmission information includes position information indicating the position of another wireless communication device. In the case of FIG. 5, the communication part 6 receives the transmission information transmitted from each of the vehicle-mounted devices 8-1 and 8-2 (step S2). The transmission information is vehicle information including position information indicating the positions of the in-vehicle devices 8-1 and 8-2.

  Based on the transmission information received by the communication unit 6, the determination unit 23 determines whether another wireless communication device that is a communication partner is an in-vehicle device (step S3). In the present embodiment, the transmission information is vehicle information transmitted from each of the in-vehicle devices 8-1 and 8-2. As described above, the vehicle information includes the vehicle ID. For this reason, the determination unit 23 can determine that both of the wireless communication devices that are transmission sources of the transmission information are in-vehicle devices (Yes in step S3). In step S3, when it is determined that at least one wireless communication device is an in-vehicle device (Yes in step S3), the process proceeds to the next step S4.

  With respect to the wireless communication devices (in-vehicle devices 8-1 and 8-2) determined to be in-vehicle devices, the information acquisition unit 22 uses these in-vehicle devices 8-1 and 8- in accordance with the transmission information (vehicle information). Based on the position information of No. 2 and its own position information, acquisition of relative position information regarding the relative position between each of the in-vehicle devices 8-1 and 8-2 and itself is started (step S4).

That is, based on the position information of the in-vehicle device 8-1 included in the transmission information from the in-vehicle device 8-1 and the own position information acquired by the pedestrian terminal device 1, the information acquisition unit 22 Preliminary information indicating the distance between the in-vehicle device 8-1 and itself is acquired (step S5). Further, the acquisition of the preliminary information is repeatedly performed every predetermined time (for example, every second).
Even if this process of obtaining the preliminary information is repeated, the in-vehicle device 8-1 and itself (the pedestrian terminal device 1) are present in the same vehicle 41-1, and therefore the in-vehicle device 8-1 and itself. The distance to is constant (almost constant) without changing. For this reason, the information acquisition part 22 acquires the relative position information (information A) which shows that the fluctuation | variation of a relative position is small over predetermined time regarding the vehicle equipment 8-1 (step S7).

  For example, the information acquisition unit 22 compares the distance change Δ for each predetermined time based on the preliminary information with a preset threshold value α (step S6), and the distance change Δ is less than the threshold value α. If there is (Yes in step S6), it can be determined that the distance remains constant over a predetermined time, and the information A is acquired (step S7). The threshold value can be a general vehicle length (for example, 4.5 m).

On the other hand, regarding the in-vehicle device 8-2 in FIG. 5, in step S5, the position information of the in-vehicle device 8-2 included in the transmission information from the in-vehicle device 8-2 and the pedestrian terminal device 1 are included. The information acquisition unit 22 also acquires preliminary information indicating the distance between the in-vehicle device 8-2 and itself based on the acquired position information. Further, the acquisition of the preliminary information is repeatedly performed every predetermined time.
Since both the vehicle 41-1 and the vehicle 41-2 are traveling in different directions, the distance between the in-vehicle device 8-2 and itself changes every moment. Accordingly, the information acquisition unit 22 makes a “No” determination in step S6 when the change Δ in the distance for each predetermined time based on the preliminary information is compared with a preset threshold value α. In this case, the information acquisition unit 22 acquires relative position information (information B) indicating that the relative position variation is large with respect to the in-vehicle device 8-2 (step S8).

And the communication control part 21 controls radio | wireless transmission by the communication part 6 based on the said relative position information which the information acquisition part 22 acquired (step S9, step S10).
That is, as described above, the relative position indicating that the variation in relative position between the wireless communication device (on-vehicle device 8-1) determined to be an in-vehicle device by the determination unit 23 and the self is small over a predetermined time. Since the information (information A) is acquired by the information acquisition unit 22 (step S7), in this case, the communication control unit 21 executes restriction control for interrupting wireless transmission by the communication unit 6 or reducing the transmission frequency. (Step S10).

  If at least one piece of the information A has been acquired by the information acquisition unit 22 (Yes in step S9), the restriction control is executed. That is, in the present embodiment, information B is also acquired in relation to the in-vehicle device 8-2. However, since the information A is acquired in relation to the in-vehicle device 8-1, the restriction control is executed. Is done.

In the pedestrian terminal device 1, in a normal state until execution of restriction control is started, information is transmitted if there is a transmission opportunity according to the communication procedure by CSMA, but when restriction control is started, Cancel this transmission. This canceling process is a wireless transmission interruption. In this case, the communication unit 6 is in a reception-only state.
Further, the transmission frequency reduction executed as the restriction control is a case where information transmission is performed at the next transmission opportunity without transmission of information even if there is a transmission opportunity by CSMA.

As described above, in step S3 in FIG. 4, the relative relationship between the other wireless communication device (the vehicle-mounted device 8-1) determined by the determination unit 23 as the vehicle-mounted device and the pedestrian terminal device 1 (self). When the relative position information (information A) indicating that the variation in position is small over a predetermined time has been acquired (step S7), the vehicle 41 on which the other wireless communication device (on-vehicle device 8-1) is mounted. It is considered that the pedestrian terminal device 1 (self) is also on -1 (see FIG. 5).
Therefore, in this case, the pedestrian terminal device 1 gives priority to the wireless communication by the in-vehicle device 8-1 by interrupting the wireless transmission or reducing the transmission frequency. That is, in the vehicle 41-1, the in-vehicle device 8-1 is representative and transmits information to the surroundings. This makes it possible to effectively use the wireless communication band.

[Second Embodiment of Wireless Communication Method]
FIG. 6 is a flowchart illustrating the wireless communication method. FIG. 7 is a diagram illustrating a part of FIG. 1, and the terminal owner who has the pedestrian terminal device 1 </ b> A is on a vehicle not equipped with the in-vehicle device. This vehicle is a bus 41a, and a plurality of terminal owners (pedestrians) each carrying another pedestrian terminal device 1B (another wireless communication device) are on the bus 41a.

  A wireless communication method executed by the pedestrian terminal device 1A on the bus 41a will be described. The detection unit 24 of the pedestrian terminal device 1A determines whether the terminal holder carrying the pedestrian terminal device 1A is walking (walking state) or moving on a vehicle (vehicle) (running). State) is determined (step S20). This determination means is as described above, and the description thereof is omitted here. In the present embodiment, the detection unit 24 detects that the terminal holder is not in the walking state but in the traveling state on the bus 41a (Yes in step S20).

  And the position acquisition part 4 of 1 A of pedestrian terminal devices acquires the positional information which shows own present position (step S31). The acquisition of the position information is repeatedly executed, and continues to be acquired while updating information about the current position that changes every moment, and new position information is given to the central processing unit 2.

  In addition, the communication unit 6 receives transmission information transmitted from other wireless communication devices existing in the vicinity (step S21). This transmission information includes position information indicating the position of another wireless communication device. In the case of FIG. 7, the communication part 6 receives the transmission information transmitted from each of a plurality of other pedestrian terminal devices 1B (step S21). The transmission information includes position information indicating the position of each pedestrian terminal device 1B.

  Based on the transmission information received by the communication unit 6, the determination unit 23 determines whether or not each of the plurality of other wireless communication devices that are communication partners is an in-vehicle device (step S22). In the present embodiment, since the vehicle ID is not included in the transmission information of the pedestrian terminal device 1B, the determination unit 23 is configured so that all of the plurality of other wireless communication devices that are communication partners are in-vehicle devices. It is determined that there is no (No in step S22).

  For each wireless communication device (pedestrian terminal device 1B) determined not to be an in-vehicle device, the information acquisition unit 22 uses the transmission information received by the communication unit 6 to determine the position information of each of these pedestrian terminal devices 1B. And acquisition of the relative position information regarding the relative position of each pedestrian terminal device 1B and itself is started based on own position information (step S23).

That is, based on the position information of the pedestrian terminal device 1B included in the transmission information from each pedestrian terminal device 1B and the own position information acquired by the pedestrian terminal device 1A, the information acquisition unit 22 The preliminary information indicating the distance between the pedestrian terminal device 1B and itself (1A) is acquired (step S24). Further, the acquisition of the preliminary information is repeatedly performed every predetermined time (for example, every second).
Even if this preliminary information acquisition process is repeated, the other pedestrian terminal device 1B and itself (the pedestrian terminal device 1) exist in the same bus 41a. The distance from itself (1A) remains constant (almost constant). Therefore, the information acquisition unit 22 acquires relative position information (information A) indicating that the relative position variation is small over a predetermined time (step S26).

  For example, the information acquisition unit 22 compares the change in distance Δ for each predetermined time based on the preliminary information with a preset threshold value α (step S25), and the change in distance Δ is less than the threshold value α. If there is (Yes in Step S25), it can be determined that the distance remains constant over a predetermined time, and the information A is acquired (Step S26).

And the communication control part 21 controls radio | wireless transmission by the communication part 6 based on the said relative position information which the information acquisition part 22 acquired (step S27).
That is, the determination unit 23 determines that all of the plurality of other wireless communication devices are not on-vehicle devices (that is, all are pedestrian terminal devices 1B) (No in step S22), and the information acquisition unit 22 Accordingly, when the relative position information (information A) indicating that the relative position variation between each of the plurality of other wireless communication devices serving as communication partners and the communication partner is small over a predetermined time is acquired (step S26). ), The communication control unit 21 executes restriction control for interrupting wireless transmission by the communication unit 6 or reducing the transmission frequency (step S27).

  In particular, in the present embodiment, relative to another wireless communication device (pedestrian terminal device 1) that is determined not to be an in-vehicle device by the determination unit 23 and relative to the fluctuation of the position relative to itself is small over a predetermined time. Since the position information (information A) is acquired by the information acquisition unit 22, the communication control unit 21 thereby performs restriction control for interrupting wireless transmission by the communication unit 6 or reducing the transmission frequency (step S27). ). The restriction control is the same as the restriction control described in the embodiment of FIG.

As described above, relative position information (information A) indicating that a change in relative position between each of a plurality of other wireless communication devices that are not in-vehicle devices and the pedestrian terminal device 1A (self) is small over a predetermined time. (Step S26), it is considered that these other wireless communication devices are also pedestrian terminal devices 1B and are on the same bus 41a including themselves (FIG. 7). reference).
Therefore, in this case, the pedestrian terminal device 1A gives priority to the wireless communication by the other pedestrian terminal device 1B by interrupting the wireless transmission or reducing the transmission frequency. That is, on the bus 41a, the other pedestrian terminal device 1B represents information and transmits information to the surroundings. This makes it possible to effectively use the wireless communication band.

FIG. 7 shows a case where the surrounding pedestrian terminal device 1B serving as the communication partner is on the same bus 41a. Unlike this, the surrounding pedestrian terminal device 1B serving as the communication partner is illustrated in FIG. As shown in FIG. 8, the case where the pedestrian terminal device 1A is not on the bus 41a on which the pedestrian terminal device 1A is on, and is present around the bus 41a will be described.
In this case, since the surrounding pedestrian terminal device 1B is a communication partner of the pedestrian terminal device 1A, the same processing as that up to step S23 is executed in FIG. Preliminary information indicating the distance between each person terminal device 1B and itself is acquired (step S24). And acquisition of this preliminary information is repeatedly performed for every predetermined time (for example, every 1 second).

In the case of FIG. 8, when the process of acquiring the preliminary information is repeatedly performed, the other pedestrian terminal device 1B does not exist in the same bus 41a as itself (pedestrian terminal device 1). The distance between 1B and itself (the pedestrian terminal device 1A) changes every moment.
Therefore, the information acquisition unit 22 compares the distance change Δ for each predetermined time based on the preliminary information with a preset threshold value α (step S25). Since it exceeds (No in step S25), the information acquisition unit 22 acquires relative position information (information B) indicating that the relative position variation between each pedestrian terminal device 1B and itself is large (step B). S28).

In this case, as control of radio transmission by the communication control unit 21, the communication control unit 21 executes control to continue radio transmission by the communication unit 6 or increase the transmission frequency (step S29).
This is because relative position information (information B) indicating that the relative position variation between each of the plurality of pedestrian terminal devices 1B as communication partners and the pedestrian terminal device 1A (self) is large is acquired. Therefore, although there are a plurality of pedestrian terminal devices 1B around as a communication partner, it is considered that they are not on the bus 41a on which they are riding, and in this case, in the bus 41a As a device having a wireless communication function, there is only one pedestrian terminal device 1A (self). Therefore, this pedestrian terminal device 1 </ b> A (self) performs active wireless transmission to function as an in-vehicle device. As this aggressive radio transmission, control is performed to continue the radio transmission instead of stopping it or to increase the transmission frequency.

  Thereby, on the bus 41a, the pedestrian terminal device 1A transmits information to the surroundings. In addition, when increasing transmission frequency, you may change the frequency according to the moving speed of the bus | bath 41a, ie, the moving speed which the acceleration sensor of the pedestrian terminal device 1 detects. For example, the transmission frequency may be increased as the moving speed increases.

  In FIG. 8, since no on-vehicle device is mounted on the bus 41a, “No” is determined in step S22. However, if the in-vehicle device is mounted on the bus 41a, “Yes” is determined in step S3 based on the communication control method shown in FIG. 4, and as a result, the restriction control in step S10 in FIG. Is executed. That is, priority is given to the in-vehicle device 41a of the bus.

  The wireless communication method by the pedestrian terminal device 1 (1A) according to each of the above embodiments will be described with reference to FIG. 4. Position information indicating the position of the other wireless communication device transmitted from the other wireless communication device is obtained. The received transmission information is received (step S2), and based on the position information of the other wireless communication apparatus and its own position information, the relative position information regarding the relative position between the other wireless communication apparatus and itself is acquired (Steps S4 to S8), and wireless transmission is controlled based on the acquired relative position information (Step S10).

Thereby, 1 A of pedestrian terminal devices identify what kind of environment is used by relationship with another radio | wireless communication apparatus, and the radio | wireless transmission by the said pedestrian terminal device 1A is controlled according to this. . Therefore, as described in FIG. 5, when the pedestrian terminal device 1 is used in an environment in which the pedestrian terminal device 1 moves on the same vehicle 41-1 as the in-vehicle device 8 that is another wireless communication device, the pedestrian terminal device 1. The wireless communication by the in-vehicle device 8 can be prioritized in advance of the wireless transmission by, and the wireless communication band can be used effectively.
The information about the vehicle 41 is transmitted from the in-vehicle device 8 to the surroundings, and the surrounding pedestrian terminal devices that have received this information can know the presence of the vehicle 41 and execute processing for safe walking. It becomes possible to do.

  The above-described embodiments are all illustrative and do not limit the scope of the present invention. The scope of the present invention is shown not by the above embodiment but by the scope of claims for patent, and includes modifications within the scope equivalent to the configurations of the scope of claims for patent.

  1: Pedestrian terminal device 2: Central processing unit (processing unit) 6: Communication unit 8: In-vehicle device 8-1, 8-2: In-vehicle device 21: Communication control unit 22: Information acquisition unit (acquisition unit) 23: Determination Part 24: Detection part

Claims (8)

A pedestrian terminal device capable of acquiring position information indicating a current position,
A communication unit capable of wirelessly transmitting the position information and receiving position information indicating the position of the other wireless communication apparatus transmitted from another wireless communication apparatus;
Based on the position information of the other wireless communication device and its own position information, an acquisition unit that acquires relative position information regarding the relative position between the other wireless communication device and itself;
Based on the relative position information acquired by the acquisition unit, a communication control unit that controls wireless transmission by the communication unit;
A pedestrian terminal device comprising:   The pedestrian terminal device according to claim 1, wherein the communication unit is capable of wireless communication with an in-vehicle device that is the other wireless communication device existing around. Based on information transmitted from the other wireless communication device and received by the communication unit, further includes a determination unit that determines whether the other wireless communication device is an in-vehicle device,
When the acquisition unit acquires the relative position information indicating that the fluctuation of the relative position between itself and another wireless communication device determined to be an in-vehicle device by the determination unit is small over a predetermined time. ,
The pedestrian terminal device according to claim 1, wherein the communication control unit executes control for interrupting wireless transmission by the communication unit or reducing transmission frequency. A determination unit that determines whether each of the plurality of other wireless communication devices is an in-vehicle device based on information transmitted from a plurality of other wireless communication devices and received by the communication unit;
The determination unit determines that a plurality of other wireless communication devices serving as communication partners are not on-vehicle devices, and the acquisition unit includes the plurality of other wireless communication devices serving as communication partners. When the relative position information indicating that a change in position relative to itself is small over a predetermined time is acquired,
The pedestrian terminal device according to claim 1, wherein the communication control unit executes control for interrupting wireless transmission by the communication unit or reducing transmission frequency. The terminal owner is not in a walking state where he / she is walking, but the terminal holder is further provided with a detection unit for detecting that the terminal owner is in a traveling state where he / she is moving on a vehicle,
The detection unit detects that the vehicle is in the traveling state, and the acquisition unit has a large variation in relative position between each of the plurality of other wireless communication devices that are communication partners. When the relative position information shown is acquired,
The pedestrian terminal device according to claim 4, wherein the communication control unit executes control to continue radio transmission by the communication unit or increase a transmission frequency. The communication unit receives movement information indicating one or both of a movement speed and a movement direction of the other wireless communication device together with the position information of the other wireless communication device,
The pedestrian terminal device according to any one of claims 1 to 5, wherein the acquisition unit acquires the relative position information by using the movement information in an auxiliary manner. A computer program for causing a computer to function as a pedestrian terminal device including a processing unit that performs various processes including control of wireless transmission and capable of acquiring position information indicating a current position,
Receiving position information indicating the position of the other wireless communication device transmitted from the other wireless communication device;
Acquiring relative position information on the relative position between the other wireless communication device and itself based on the position information of the other wireless communication device and the position information of the other wireless communication device;
Controlling the wireless transmission based on the acquired relative position information;
A computer program comprising: A wireless communication method provided by a pedestrian terminal device that includes a processing unit that performs various processes including control of wireless transmission and that can acquire position information indicating a current position,
Receiving position information indicating the position of the other wireless communication device transmitted from the other wireless communication device;
Based on the position information of the other wireless communication device and its own position information, obtain relative position information regarding the relative position between the other wireless communication device and itself,
A wireless communication method, wherein the wireless transmission is controlled based on the acquired relative position information.

Images