JP2008217120A - Communication system, terminal unit, and on-vehicle unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a communication system, a terminal unit, and an on-vehicle unit for communicating between a terminal unit carried by a person and an on-vehicle unit mounted on a vehicle with an appropriate communication volume. <P>SOLUTION: A communication system having each terminal unit carried by a person and an on-vehicle unit 10 mounted on a vehicle to make communication between each of the terminal units and the on-vehicle unit 10 calculates a degree of a collision risk between each of the terminal units and the vehicle; each of terminal units in an A group having a high degree of the collision risk directly communicates with the on-vehicle unit 10; each of terminal units in a B group having a middle degree of the collision risk communicates with the on-vehicle unit 10 via a representative terminal unit in the B group, and each of terminal units in a C group having a low degree of the collision risk communicates with the on-vehicle unit 10 via a representative terminal unit in the C group. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a communication technique between a terminal device possessed by a person and an in-vehicle device mounted on a vehicle.

Conventionally, a vehicle communication system that performs wireless communication between a base station and a plurality of vehicles is known (see, for example, Patent Document 1). In this vehicle communication system, an area where a vehicle exists is divided into a plurality of areas according to the distance from the base station, and a longer communication interval is set for a vehicle in an area far from the base station. Thus, the communication frequency of vehicles that are not required to be frequently communicated is reduced, unnecessary communication is eliminated, and the concentration of reception at the base station is alleviated.
JP 2001-44922 A

  By the way, in the case of a system that avoids a collision between a person and a vehicle by communicating between a communication device possessed by the person and a communication device mounted on the vehicle, the person and the vehicle move differently (for example, moving speed) Therefore, even if the distance between the person and the vehicle is long, the necessity for communication is not necessarily low. Therefore, even if the above-mentioned conventional technology is applied to such a collision avoidance system and the communication interval is set according to the distance between the person and the vehicle, more than necessary communication is performed or information to be transmitted / received is insufficient. There is a risk of

  Accordingly, the present invention provides a communication system, a terminal, and an in-vehicle device that can perform communication between a terminal device possessed by a person and an in-vehicle device mounted in the vehicle with an appropriate communication amount. And

In order to achieve the above object, the first invention provides:
A communication system between the terminal and the in-vehicle device, comprising a terminal device carried by a person and an in-vehicle device mounted on the vehicle,
A collision risk calculating means for calculating a collision risk between the terminal and the vehicle;
The terminal and the in-vehicle device communicate with each other by a communication method in which the communication amount between the terminal and the in-vehicle device is an amount corresponding to the collision risk calculated by the collision risk calculating means. . Thereby, since it can be set as the communication amount according to the collision risk of the owner of a terminal and a vehicle, it can communicate with the appropriate communication amount which avoided excessive communication and insufficient communication.

A second invention is a communication system according to the first invention,
It is characterized by comprising notifying means for notifying proximity information between the owner of the terminal and the vehicle based on the collision risk calculated by the collision risk calculating means. Thereby, appropriate proximity information based on the collision risk can be notified to the owner side or the vehicle side.

The third invention is a communication system according to the first or second invention,
The collision risk calculation means calculates the collision risk based on the behavior of the owner of the terminal and the behavior of the vehicle. Thereby, the exact collision risk according to both behavior is computable.

A fourth invention is a communication system according to any one of the first to third inventions,
The amount of communication decreases as the collision risk decreases. Thereby, communication traffic can be moderated appropriately according to the collision risk.

A fifth invention is a communication system according to any one of the first to third inventions,
A terminal having a lower collision risk than other terminals communicates with a communication method in which the amount of communication with the in-vehicle device is smaller than that of the other terminals. Accordingly, communication traffic can be reduced by reducing the communication amount of the terminal having a low collision risk.

The sixth invention is a communication system according to the fourth or fifth invention,
Communication between the terminal and the in-vehicle device having the collision risk level equal to or higher than a predetermined level is performed directly,
The communication between the terminal having a collision risk level lower than the predetermined level and the in-vehicle device is performed through a representative terminal that is a representative of the terminals constituting the terminal group. Since the terminal device with a low collision risk communicates with the vehicle-mounted device via the representative terminal, communication traffic can be moderated appropriately. That is, a terminal with a high risk of collision can acquire sufficient information from the vehicle by performing direct communication, and a terminal with a low risk of collision can suppress communication with low necessity.

A seventh invention is a communication system according to the sixth invention,
According to the risk of collision, the ratio of the representative terminals in the terminal group to the terminals constituting the terminal group is changed. Accordingly, the number of representative terminals is not limited to one, and the higher the collision risk level, the more the terminal can communicate with the vehicle and can acquire sufficient information from the vehicle.

Further, an eighth invention is a communication system according to the sixth or seventh, wherein
The representative terminal acquires identification information of terminals belonging to the same terminal group as itself and transmits the identification information together with its own identification information to the in-vehicle device,
The on-vehicle device returns identification information of a terminal that should be notified of the approach of the vehicle.

In order to achieve the above object, the ninth invention provides
A terminal that is owned by a person and communicates with an in-vehicle device mounted on a vehicle,
A collision risk acquisition means for acquiring a collision risk between the terminal and the vehicle;
The communication amount between the terminal and the in-vehicle device communicates with the in-vehicle device by a communication method in which the communication amount becomes an amount corresponding to the collision risk acquired by the collision risk acquiring means. Thereby, since it can be set as the communication amount according to the collision risk of the owner of a terminal and a vehicle, it can communicate with the appropriate communication amount which avoided excessive communication and insufficient communication.

The tenth invention is a terminal according to the ninth invention,
Based on the collision risk obtained by the collision risk obtaining means, proximity information to the vehicle is notified to the owner of the terminal. Thereby, appropriate proximity information based on the collision risk can be notified to the owner side.

The eleventh invention is a terminal according to the ninth or tenth aspect,
When the collision risk level is lower than a predetermined level, the terminal device communicates with the in-vehicle device on behalf of another terminal device.

The twelfth invention is a terminal according to the ninth to eleventh inventions,
The communication interval with the in-vehicle device is changed according to the collision risk. By changing the communication interval, it is possible to set the communication amount according to the collision risk between the owner of the terminal and the vehicle, so that communication can be performed with an appropriate communication amount that avoids excessive communication or insufficient communication. .

In order to achieve the above object, the thirteenth invention is
An in-vehicle device that is mounted on a vehicle and communicates with a terminal owned by a person,
A collision risk acquisition means for acquiring a collision risk of the terminal and the vehicle;
The communication amount between the terminal and the vehicle-mounted device communicates with the terminal by a communication method in which the amount of communication according to the collision risk acquired by the collision risk acquisition means is used. Thereby, since it can be set as the communication amount according to the collision risk of the owner of a terminal and a vehicle, it can communicate with the appropriate communication amount which avoided excessive communication and insufficient communication.

The fourteenth invention is an in-vehicle device according to the thirteenth invention,
Based on the collision risk obtained by the collision risk obtaining means, the proximity information to the terminal is notified to the occupant of the vehicle. Thereby, appropriate proximity information based on the collision risk can be notified to the vehicle occupant.

  ADVANTAGE OF THE INVENTION According to this invention, communication between the terminal device which a person possesses, and the vehicle equipment mounted in the vehicle can be performed with appropriate communication amount.

  The best mode for carrying out the present invention will be described below.

[Outline of the approach notification system]
As an embodiment of a communication system according to the present invention, an approach notification system will be described as an example. FIG. 1 is a diagram showing a configuration of an approach notification system. As shown in FIG. 1, the approach notification system includes an in-vehicle device 10 provided with communication means, and a mobile terminal 12 provided with a communication means that is a mobile terminal possessed by a pedestrian. The approach notification system notifies the vehicle side such as the driver and the in-vehicle system and / or the owner side of the portable terminal 12 that the vehicle on which the vehicle-mounted device 10 is mounted and the owner of the portable terminal 12 are approaching each other. It is. A person who rides a motorcycle such as a light vehicle including a bicycle or a motor-driven bicycle may carry the portable terminal 12. The mobile terminal 12 may be a terminal dedicated to this system, or may be a mobile phone or a personal digital assistance (PDA) in terms of being portable.

  The vehicle-mounted device 10 starts to transmit radio waves intermittently or continuously at a predetermined constant output when the approach notification system is permitted to start after the vehicle engine is started. When the vehicle that was away from each other and a pedestrian carrying the mobile terminal 12 approached, the mobile terminal 12 entered the area where the transmission wave of the in-vehicle device 10 was reachable. An activation signal can be received. The mobile terminal 12 that has received the activation signal starts radio wave transmission for the vehicle-mounted device 10 to detect its presence. The transmission wave of the portable terminal 12 is transmitted intermittently with a predetermined constant output. And the transmission wave of the portable terminal 12 is received by the vehicle equipment 10. By operating in this way, the in-vehicle device 10 can grasp the presence of a pedestrian or the like carrying the portable terminal 12, while the portable terminal 12 can grasp the presence of a vehicle equipped with the in-vehicle device 10. Therefore, the in-vehicle device 10 can notify the driver of the vehicle of the presence of a pedestrian or the like, and the mobile terminal 12 can notify the owner of the vehicle of the presence of the vehicle.

[Configuration of mobile terminal 12]
FIG. 2 is a block diagram of the mobile terminal 12. The portable terminal 12 has an antenna 1 for transmitting / receiving radio waves having a predetermined frequency (for example, 2.4 GHz) to / from the outside. The duplexer 2 switches transmission / reception signals. When the antenna 1 is divided for transmission and reception, the duplexer 2 can be omitted. The receiving unit 17 receives a radio wave (that is, a carrier) transmitted by the in-vehicle device 10 via the antenna 1 (hereinafter, the radio wave transmitted by the in-vehicle device 10 is referred to as “in-vehicle device transmission wave”).

  The ID adding / detecting unit 18 detects an activation signal from information obtained by the receiving unit 17 demodulating the vehicle-mounted device transmission wave. The ID addition / detection unit 18 that has detected the activation signal adds its own terminal ID (identification information for identifying each mobile terminal 12) given to each mobile terminal 12 to the transmission data, and the transmission unit 16 modulates the transmission data. To start radio wave transmission for detecting the presence of the mobile terminal 12 via the antenna 1. Hereinafter, the radio wave transmitted by the mobile terminal 12 via the antenna 1 is referred to as “terminal transmission wave”. The terminal transmission wave is intermittently transmitted at a predetermined constant output.

  The ID adding / detecting unit 18 detects an ID from information obtained by the receiving unit 17 demodulating the vehicle-mounted device transmission wave. If the ID detected by the ID adding / detecting unit 18 includes its own terminal ID, the possibility of a collision between the vehicle that is the transmission source of the in-vehicle device transmission wave and the owner of the own terminal is determined. In order to do this, calculation of the collision risk described later is started. That is, in order for the vehicle-mounted device 10 that has received the terminal transmission wave including the terminal ID to inform the mobile terminal 12 that has the terminal ID that the vehicle is approaching, the vehicle approach including the terminal ID is performed. The in-vehicle device transmission wave is transmitted as information. The vehicle-mounted device transmission wave transmitted by the vehicle-mounted device 10 includes vehicle ID information given to each vehicle-mounted device 10 or each vehicle on which the vehicle-mounted device 10 is mounted so that the transmission source can be specified. May be.

  The collision risk degree calculation unit 13 is based on the behavior information of the mobile terminal 12 and the behavior information of the vehicle included in the in-vehicle device transmission wave, and there is a possibility that the owner of the own terminal and the vehicle that transmitted the in-vehicle device transmission wave collide. Is calculated. The vehicle behavior information includes vehicle ID, position information, speed information, acceleration / deceleration information, traveling direction information, brake state, accelerator state, and the like related to the vehicle. The behavior information of the mobile terminal 12 includes position information, speed information, acceleration / deceleration information, traveling direction information, altitude information, and the like regarding the mobile terminal 12. The collision risk calculation unit 13 acquires vehicle behavior information from the in-vehicle device transmission wave, and from a behavior detection sensor (for example, an orientation sensor, an acceleration sensor, a GPS device, a geomagnetic sensor, an atmospheric pressure sensor, etc.) provided in the terminal itself. Get behavior information of own terminal.

  When calculating / determining the collision risk level, the collision risk level calculation unit 13 collides with the vehicle on which the owner of the mobile terminal 12 has transmitted the in-vehicle device transmission wave based on the behavior information of the vehicle and the behavior information of the mobile terminal 12. Collision prediction time TTC (Time To Collision) until this is calculated. The collision risk calculation unit 13 calculates and determines the collision risk according to the calculated TTC. The TTC is generally obtained by dividing the distance between the mobile terminal 12 and the vehicle by the speed difference between them. That is, TTC corresponds to the time until the vehicle collides with the portable terminal 12 (the owner) when the speed difference between the portable terminal 12 and the vehicle at a certain moment continues as it is. Therefore, it can be regarded that the collision risk increases as the TTC value decreases. In addition, by using altitude information (which can be detected by an atmospheric pressure sensor, a geomagnetic sensor, or the like) included in the behavior information of the mobile terminal 12, the miscalculation of the collision risk when the owner of the mobile terminal 12 is located on a pedestrian bridge It is possible to prevent malfunctions based on the output. A specific method for calculating the collision risk will be described later.

  The belonging group determination unit 14 determines a group to which the mobile terminal 12 should belong based on the collision risk calculated by the collision risk calculation unit 13. Affiliation groups are classified according to the numerical value of the collision risk, and IDs (referred to as group IDs) such as A, B, and C are assigned to each group. For example, when the numerical value of the collision risk is 0 or more and less than 10, it is classified into Group C, when it is 10 or more and less than 20, it is classified into Group B, and when it is 20 or more, it is classified into Group A. The That is, the portable terminal 12 having a relatively high collision risk belongs to the group A, and the portable terminal 12 having a low collision risk belongs to the group C.

  The information providing unit 20 provides vehicle approach information and warning information to the owner of the terminal by voice information, visual display information, vibration, and the like according to the group ID determined by the belonging group determination unit 14. . When the group ID is A, the information providing unit 20 provides the vehicle with detailed access information for avoiding a collision with the vehicle because the collision risk is high. In addition, when the group ID is B or C, the information providing unit 20 provides the information that the owner is not necessarily required to provide detailed information because the risk of collision is lower than that of the group A. Limit the behavior of For example, when the group ID is B, the information providing unit 20 reduces the information provision content or lowers the warning level as compared with the case where the group ID is A, and does not provide the information when the group ID is C. Like that.

  The communication method determination unit 15 determines a communication method between the terminal itself and the vehicle according to the group ID determined by the belonging group determination unit 14. The communication method determination unit 15 determines to perform communication using a method in which the communication amount is reduced as the group ID has a lower collision risk. This is because if the risk of collision is low, the necessity of communication between the vehicle and the portable terminal 12 can be considered low.

  Since the collision risk is high when the group ID is A, the communication method determination unit 15 determines the communication method of the mobile terminal 12 as a communication method (for example, a peer-to-peer method) that directly communicates with the vehicle. Thereby, since it does not go through another communication apparatus, the communication delay between the A group portable terminal 12 and a vehicle can be suppressed as much as possible. When the group ID is B or C, the collision risk is lower than that of A, so the communication method of the mobile terminal 12 is determined to be the master / slave method. Thereby, since the amount of communication can be suppressed, it is possible to give priority to the communication of the group A mobile terminals 12 having a high collision risk, and to suppress the occurrence of congestion.

  The master / slave method is a communication method including a representative terminal (master terminal) that communicates directly with the vehicle and a slave terminal (slave terminal) that communicates with the representative terminal without directly communicating with the vehicle. The master terminal transmits the information of each slave terminal collectively to the vehicle-mounted device 10, or the master terminal transmits the information of the vehicle-mounted device transmission wave to each slave terminal, whereby each mobile terminal 12 transmits the information. The channel can be saved as compared with the case where the channel is used, and the channel can be used more effectively. Accordingly, when a plurality of portable terminals 12 belong to the same group, one or a plurality of neighboring terminal groups are formed, and one or a plurality of portable terminals 12 in the neighboring terminal group are master terminals of the neighboring terminal group. It is preferable to collect information on other mobile terminals 12 (slave terminals) in the proximity terminal group and transmit the information to the in-vehicle device 10.

  In this case, the master terminal acquires the ID of the slave terminal belonging to the same proximity terminal group as itself and transmits the ID to the in-vehicle device 10 together with its own ID, and the in-vehicle device 10 is the ID of the portable terminal 12 that should notify the approach of the vehicle. Is preferably returned. As a result, even if the slave terminal does not transmit itself to the in-vehicle device 10, the slave terminal can notify the terminal owner of the approach of the vehicle depending on whether the ID returned by the in-vehicle device 10 has its own ID or not. It is possible to determine whether the terminal is to be notified.

  Depending on the collision risk calculated by the collision risk calculation unit 13, the communication method determination unit 15 sets the own terminal as the master terminal of the own terminal group or the own terminal as the slave terminal of the own terminal group. Decide whether to set up the terminal. The communication method determination unit 15 of each mobile terminal 12 sets the self terminal as a master terminal when the collision risk of the self terminal is equal to or greater than a predetermined value, and sets the self terminal as a slave terminal when the collision risk is less than the predetermined value. . Thereby, the number of master terminals included in each affiliation group can be increased or decreased according to the collision risk. That is, even if it is the mobile terminal 12 of the B group or the C group, if the collision risk is high, if it is set as a master terminal capable of directly communicating with the vehicle, appropriate communication according to the collision risk is performed with the vehicle. be able to.

  Moreover, since the communication system determination part 15 adjusts communication amount according to group ID, you may set the transmission interval of a terminal transmission wave according to group ID. The communication method determination unit 15 sets the transmission ID of the terminal transmission wave to be shorter for the group ID having a higher collision risk. As a result, the closer the mobile terminal 12 belonging to the group having a higher collision risk, the closer the transmission and reception of approach information becomes possible.

  The mobile terminal 12 acquires the behavior information of the own terminal from the behavior detection sensor provided in the own terminal. However, according to the collision risk calculated by the collision risk calculation unit 13, the acquisition interval of the behavior information is acquired. May be changed. For example, the power consumption of the portable terminal 12 having a low collision risk can be suppressed by increasing the acquisition interval for the portable terminal 12 having a lower collision risk.

[Configuration of in-vehicle device 10]
FIG. 3 is a block diagram of the in-vehicle device 10. The in-vehicle device 10 has an antenna 21 for transmitting / receiving radio waves having a predetermined frequency to / from the outside. Moreover, it has the circulator 22 for isolate | separating a transmission wave and a received wave. The receiving unit 23 receives the radio wave from the mobile terminal 12 received by the antenna 21 and acquires the ID of the mobile terminal 12 in the received data. The reception level detection unit 24 connected to the reception unit 23 detects a reception level indicating the reception sensitivity of the radio wave received by the reception unit 23. A direction / distance estimation unit 25 is connected to the reception level detection unit 24. Information on the reception level detected by the reception level detection unit 24 is supplied to the direction / distance estimation unit 25.

  A directivity control unit 26 that controls the directivity of the antenna 21 is connected to the direction / distance estimation unit 25. The direction / distance estimation unit 25 sends information on the azimuth direction to be received to the vehicle. The directivity control unit 26 switches the directivity of the antenna 21 according to the azimuth angle direction supplied from the direction / distance estimation unit 25. The direction / distance estimating unit 25 possesses the arrival direction and distance of radio waves, that is, the portable terminal 12 when receiving levels for all azimuth directions are supplied from the receiving level detecting unit 24 by switching the directivity of the antenna 21. Estimate the direction in which the person is present and the distance to that person. For example, when the reception level of the terminal transmission wave when the directivity of the antenna 21 is switched to one direction among the reception levels of the terminal transmission wave when the directivity of the antenna 21 is switched in each direction is maximum. The direction / distance estimating unit 25 estimates that there is a pedestrian carrying the mobile terminal 12 in one direction, and sets the reception level value of the terminal transmission wave when the directivity of the antenna 21 is switched to the one direction. It is estimated that a pedestrian possessed by the portable terminal 12 exists at a point separated by a corresponding distance. Since the value of the reception level of the terminal transmission wave changes according to the distance between the vehicle and the portable terminal 12, the direction / distance estimation unit 25 is a map value that defines the relationship between the value of the reception level of the terminal transmission wave and the distance. The distance to the pedestrian carrying the mobile terminal 12 is estimated using the above. In addition, the directivity control unit 26 can control the radio wave to be transmitted toward the estimated direction of the mobile terminal 12. Furthermore, the directivity control unit 26 sets a region where radio waves are transmitted based on vehicle speed, turn signal information, and navigation information, which will be described later. In order to set a region where radio waves are transmitted, the directivity of the antenna 21 may be controlled, or a plurality of antennas having different directivity directions may be selectively controlled. Good.

  As described above, the terminal transmission wave may be received by controlling the directivity of the antenna 21 to estimate the direction in which the person holding the mobile terminal 12 exists and the distance to the person. The direction in which the person holding the portable terminal 12 is present by receiving the vehicle-mounted device transmission wave from the antenna 21 having the directivity of the vehicle-mounted device 10 by the portable terminal 12 and returning the reception level to the vehicle-mounted device 10. And the distance to the person may be estimated. That is, the gain of the directional antenna is high only in a specific direction, and the gain of the omnidirectional antenna is constant in almost all directions, and the direction in which the mobile terminal is present can be determined using the difference. The vehicle cannot grasp where the mobile terminal 12 is located with respect to the vehicle only by receiving the terminal transmission wave via the omnidirectional antenna. This is because if the distance from the vehicle is the same, the reception level is the same even if the location is different. However, when the vehicle transmits radio waves via a directional antenna having a high gain only in a specific direction, the reception level when the portable terminal 12 existing in the direction having the directivity receives the in-vehicle unit transmission wave is The mobile terminal 12 that does not exist in the direction having the directivity becomes higher than the reception level when the in-vehicle device transmission wave is received. Therefore, by comparing the reception level of the terminal transmission wave received by the vehicle via the omnidirectional antenna and the reception level of the in-vehicle device transmission wave transmitted by the vehicle via the directional antenna on the portable terminal 12 side, The direction in which the terminal 12 exists can be determined. In order to specify in more detail the direction in which the mobile terminal 12 exists, it is preferable to compare the reception level of the terminal transmission wave on the vehicle side with the maximum value of the reception level of the in-vehicle device transmission wave on the mobile terminal 12 side. And the presence position of the portable terminal 12 can be estimated based on the reception level on the portable terminal 12 side of the in-vehicle device transmission wave having directivity in the direction where the portable terminal 12 exists.

  An information provision determination unit 27 is also connected to the direction / distance estimation unit 25. Information on the presence direction and distance of the person holding the mobile terminal 12 estimated by the direction / distance estimation unit 25 is sent to the information provision determination unit 27. The information provision determination unit 27 includes information on the speed (vehicle speed) of the own vehicle detected using a vehicle speed sensor, vehicle turn signal information detected using a turn signal indicator, and a navigation system mounted on the vehicle. Navigation information such as road shape, road width, intersection shape, and lane number information in the vicinity of the current position of the vehicle detected by using the vehicle (particularly in the forward direction) is supplied. The navigation information is stored in advance in the map database of the navigation system.

  A pedestrian presence information provision area table 28 is connected to the information provision determination unit 27. In the pedestrian presence information provision area table 28, information on a pedestrian presence information provision area in which different areas are set using vehicle speed, blinker information, and navigation information as parameters is written in advance. Based on the acquired vehicle speed, turn signal information, and navigation information, the information provision determination unit 27 selects a pedestrian presence information provision area corresponding to the vehicle speed, turn signal information, and navigation information from the pedestrian presence information provision area table 28. Whether or not there is a person who possesses the portable terminal 12 in the read pedestrian presence information providing area based on the direction and distance of the person sent from the direction / distance estimating unit 25 after reading. Is determined. In addition, the pedestrian presence information providing area is not previously stored in the pedestrian presence information providing area table 28, but the pedestrian presence information providing areas corresponding to these parameters are sequentially derived according to a predetermined calculation formula. May be.

  The information provision determination unit 27 is connected to an information provision unit 29 that visually or audibly provides information to the driver of the host vehicle using a display or a speaker. When it is determined that a person is present in the pedestrian presence information provision area, the information provision determination unit 27 provides an instruction for notifying the vehicle driver that the person is present in the pedestrian presence information provision area. This is performed for the providing unit 29. When the information providing unit 29 receives an instruction to provide information from the information providing determining unit 27, the information providing unit 29 operates a display or a speaker, so that a person exists in the pedestrian presence information providing area for the own vehicle and the own vehicle is Inform the vehicle driver that there is a potential for human contact.

  The information provision determination unit 27 is further connected to a transmission unit 30 that transmits information for notifying the mobile terminal 12 of the approach of the vehicle. When it is determined that there is a person in the pedestrian presence information provision area, the information provision determination unit 27 is in the pedestrian presence information provision area from the ID of the portable terminal 12 acquired by the reception unit 23. An instruction for transmitting the ID of the portable terminal 12 is given to the transmission unit 30. When receiving the ID transmission instruction, the transmitting unit 30 transmits the ID of the portable terminal 12 in the pedestrian presence information providing area from the antenna 21 on the radio wave.

  In addition, what is necessary is just to set the above-mentioned pedestrian presence information provision area similarly to the setting method of the alarm area disclosed by Unexamined-Japanese-Patent No. 2005-202893.

[Collision risk calculation and affiliation group determination]
FIG. 4 is a diagram illustrating a positional relationship between a vehicle on which the vehicle-mounted device 10 is mounted and a holder (pedestrian) of the mobile terminal 12. The collision risk degree calculation unit 13 is configured such that the pedestrian is at an arrival distance L1 until the vehicle reaches a collision position where a collision between the vehicle and the pedestrian is predicted, and a collision position where the collision between the vehicle and the pedestrian is predicted. The collision prediction time TTC is calculated based on the reach distance L2, the vehicle speed Va, and the walking speed Vp. The predicted collision position (cross point) is a point Z1 where the traveling track Ca in the traveling direction of the vehicle and the traveling track Cp in the traveling direction of the pedestrian intersect. However, even if the trajectories cross each other, there is no collision if the time of passing through the cross point Z1 is different. Therefore, the collision risk calculation unit 13 calculates the time for the vehicle to pass the cross point Z1 based on the reach distance L1 and the vehicle speed Va, and the pedestrian determines whether the crosspoint is based on the reach distance L2 and the walking speed Vp. The time for passing through Z1 is calculated, and the position when the respective passing times are approximately the same (when the difference between the passing times is within a predetermined value) is set as a cross point Z1.

When the cross point Z1 is detected in this way, the collision prediction time TTC until reaching the cross point Z1 can be calculated by “collision prediction time TTC = L1 / Va (= L2 / Vp)”. When the vehicle decelerates due to braking, downshifting, or the like, it may be corrected by “L1 = Va ² / (2 · d)” (d is the deceleration of the vehicle).

  Further, the collision risk calculation unit 13 may calculate the collision prediction time TTC based on a map as shown in FIG. FIG. 5A is a map showing the TTC relationship with respect to the relative speed Vr between the vehicle and the pedestrian when the relative position (relative distance) Pr between the vehicle and the pedestrian is a constant value. FIG. 5B is a map showing the TTC relationship with respect to the relative position Pr between the vehicle and the pedestrian when the relative speed Vr between the vehicle and the pedestrian is a constant value. FIG. 5C is a map showing the TTC relationship with respect to the pedestrian approach angle γ in the direction of the cross point Z1 when the relative position Pr and the relative speed Vr are constant values. FIG. 5A shows that the TTC is calculated on the assumption that the TTC decreases as the relative speed Vr increases. FIG. 5B shows that the TTC is calculated on the assumption that the TTC increases as the relative position Pr increases. FIG. 5C shows that the TTC is calculated by assuming that the TTC decreases as the pedestrian approach angle γ increases toward the current point P1 side of the vehicle with respect to the cross point Z1, and the cross is calculated. This indicates that the TTC is calculated on the assumption that the TTC increases as the pedestrian approach angle γ increases on the side opposite to the current point of the vehicle with respect to the point Z1 direction. The collision risk degree calculation unit 13 calculates TTC1 estimated from the relative speed Vr and the map of FIG. 5A based on the relative speed Vr, and the relative position based on the relative position Pr and the map of FIG. 5B. The TTC2 estimated from Pr is calculated, and the TTC3 estimated from the approach angle γ is calculated based on the approach angle γ and the map of FIG. Then, the collision risk calculation unit 13 sets the minimum value of TTC1, 2, 3 as the predicted collision time TTC as the TTC estimated based on each estimation element such as the relative speed Vr.

  The collision risk level calculation unit 13 calculates the collision risk level according to the TTC set as described above based on a predetermined map or calculation formula that defines the relationship between the TTC and the collision risk level. The collision risk level is calculated so as to decrease as the TTC value increases. The collision risk calculation unit 13 may correct the collision risk according to the brake state. For example, the collision risk calculation unit 13 corrects the collision risk so as to decrease as the braking force of the brake increases. Further, the collision risk calculation unit 13 may correct the collision risk according to the accelerator state. For example, the collision risk calculation unit 13 corrects the collision risk so as to decrease as the accelerator value decreases.

  The belonging group determination unit 14 determines a group to which the mobile terminal 12 should belong based on the collision risk calculated by the collision risk calculation unit 13. Here, the affiliation group determination unit 14 does not determine the affiliation group based only on the collision risk calculated by the collision risk calculation unit 13, but the pedestrian and vehicle behavior information such as the pedestrian approach angle γ described above. May be reflected in the determination of the affiliation group. FIG. 6 is a diagram showing the relationship between the vehicle on which the in-vehicle device 10 is mounted and the group to which the mobile terminal 12 belongs. As shown in FIG. 6, when the collision risk is 20 or more, the affiliation group determination unit 14 assigns the identification information ID-A of the A group to the own terminal, assuming that the own terminal is the A group. In addition, when the collision risk is less than 20 and the traveling direction of the own terminal and the traveling direction of the vehicle intersect, the belonging group determining unit 14 determines that the own terminal is the B group and uses the identification information ID-B of the B group. Give to the terminal. In addition, when the collision risk is less than 20 and the traveling direction of the own terminal does not intersect the traveling direction of the vehicle, the belonging group determining unit 14 determines that the own terminal is the C group and uses the identification information ID-C of the C group. Give to the terminal.

  In addition, the affiliation group determination unit 14 calculates the collision risk and the affiliation group when the behavior information of the pedestrian and the vehicle acquired after determining the affiliation group of the mobile terminal 12 satisfies a predetermined affiliation group change condition. Without changing the decision process, the current group is quickly changed to a group with a high or low risk of collision (reassignment of identification information). For example, the affiliation group determination unit 14 in FIG. 4 reads: “(1) reach distance L2 <predetermined reference value, (2) 0 ≦ pedestrian approach angle γ ≦ α (α is determined according to the control upper limit speed), ( 3) When all of the belonging group changing conditions (1), (2), and (3) of “walking speed Vp> predetermined reference value” are satisfied, the group B identification information is changed to the group A identification information. As a result, when the belonging group changing condition from the B group to the A group is established, the mobile terminal 12 of the B group can be moved to the A group having a high degree of risk, so there is no delay in the arithmetic processing and there is a risk of a collision. A pedestrian whose height is high can be extracted early.

[Operation of mobile terminal 12]
7 to 10 are flowcharts showing the operation of the mobile terminal 12. FIG. 7 is a flow showing the operation of the mobile terminal 12 from activation to group determination. The portable terminal 12 is started from the sleep mode, which is a standby state for the activation signal, by receiving the activation signal of the in-vehicle device transmission wave (step 10). The mobile terminal 12 that has received the activation signal starts transmitting a terminal transmission wave to which its own terminal ID is assigned. The in-vehicle device 10 that has received the terminal transmission wave transmits the in-vehicle device transmission wave including the terminal ID, the vehicle ID, and the vehicle behavior information given to the terminal transmission wave. The mobile terminal 12 that has received the vehicle-mounted device transmission wave including its own terminal ID acquires vehicle behavior information (step 12). On the other hand, the portable terminal 12 acquires behavior information of the own terminal by a behavior detection sensor such as a GPS device or an acceleration sensor provided in the portable terminal 12 (step 14). The portable terminal 12 calculates the TTC related to the own terminal as described above based on the behavior information of the vehicle and the behavior information of the own terminal (step 14). Then, the mobile terminal 12 calculates the collision risk based on the vehicle behavior information, the behavior information of the own terminal, and the TTC (step 18), and sets the belonging group of the own terminal (step 20). The mobile terminal 12 changes the information providing method and communication method as shown in FIGS. 8 to 10 according to the group to which the mobile terminal 12 belongs (step 24).

  FIG. 8 is a flow showing the operation of the mobile terminal 12 in which the affiliation group is set as the A group. The portable terminal 12 determines the communication method of its own terminal as the direct communication method described above (step 32). And the portable terminal 12 transmits the presence information containing the behavior information of a self-terminal with respect to the vehicle equipment 10 in order to make a vehicle driver and its vehicle-mounted system recognize the presence of self (step 34). On the other hand, the portable terminal 12 acquires vehicle behavior information from the in-vehicle device 10 in order to make the owner of the terminal recognize the presence of the vehicle, and based on the acquired vehicle behavior information, the vehicle presence information Is provided to the owner of the terminal (step 36). And the portable terminal 12 judges whether the change conditions of an affiliation group are satisfied based on the behavior information of a vehicle, and the behavior information of an own terminal (step 38). When the change condition is satisfied, the process returns to step 24 in FIG. 7 to change the group ID of the own terminal to the group ID corresponding to the result of establishment. For example, when the change condition from the A group to the C group is satisfied because the traveling direction of the own terminal does not intersect the traveling direction of the vehicle, the own terminal of the A group changes the belonging group to the C group, Operate as a portable terminal 12. When the change condition is not satisfied, the process returns to step 34 and the transmission / reception of the presence information is continued with the in-vehicle device 10 as the mobile terminal of the group A.

  FIG. 9 is a flow showing the operation of the mobile terminal 12 in which the affiliation group is set as the B group. As described above, the mobile terminal 12 sets the self terminal as either the master terminal or the slave terminal according to the collision risk of the self terminal (step 52). The master terminal acquires presence information including behavior information of slave terminals belonging to the same neighboring terminal group as that of the master terminal (step 54). Then, the master terminal transmits presence information including behavior information of the own terminal and the slave terminal to the in-vehicle device 10 in order to make the driver of the vehicle and the in-vehicle system recognize the presence of itself and its own slave terminal ( Step 56). On the other hand, the master terminal acquires the behavior information of the vehicle from the in-vehicle device 10 in order to make the owner of the own terminal and the slave terminal of the own terminal recognize the presence of the vehicle, and based on the acquired behavior information of the vehicle. The vehicle presence information is provided to the owner of the terminal (step 58), and the vehicle presence information is transmitted to the slave terminal based on the acquired vehicle behavior information (step 60). On the other hand, the slave terminal transmits the presence information including the behavior information of the own terminal to the master terminal belonging to the same neighboring terminal group as itself (step 64). The slave terminal may provide vehicle presence information received from the master terminal to the owner of the terminal. After the end of step 60 or 64, the portable terminal 12 determines whether or not the belonging group changing condition is satisfied based on the behavior information of the vehicle and the behavior information of the own terminal (step 66). When the change condition is satisfied, the process returns to step 24 in FIG. 7 to change the group ID of the own terminal to the group ID corresponding to the result of establishment. For example, “(1) reaching distance L2 <predetermined reference value, (2) 0 ≦ pedestrian approach angle γ ≦ α (α is determined according to the control upper limit speed), (3) walking speed Vp> predetermined reference value. When all belonging group changing conditions of (1), (2), and (3) are established, the own terminal of the B group changes the belonging group to the A group and operates as the mobile terminal 12 of the A group. When the change condition is not satisfied, the process returns to step 54 or 64, and the master terminal continues to transmit / receive presence information to / from the in-vehicle device 10 or the slave terminal as the mobile terminal of the B group. As a portable terminal, it continues to send and receive presence information to and from the master terminal.

  FIG. 10 is a flow showing the operation of the mobile terminal 12 in which the affiliation group is set as the C group. As described above, the mobile terminal 12 sets the self terminal as either the master terminal or the slave terminal according to the collision risk of the self terminal (step 72). The master terminal acquires presence information including behavior information of slave terminals belonging to the same neighboring terminal group as that of the master terminal (step 74). Then, the master terminal transmits presence information including behavior information of the own terminal and the slave terminal to the in-vehicle device 10 in order to make the driver of the vehicle and the in-vehicle system recognize the presence of itself and its own slave terminal ( Step 76). On the other hand, the master terminal acquires the behavior information of the vehicle from the in-vehicle device 10 in order to make the slave terminal of the terminal recognize the presence of the vehicle, and based on the acquired behavior information of the vehicle, Transmit to the slave terminal (step 78). On the other hand, the slave terminal transmits the presence information including the behavior information of the own terminal to the master terminal belonging to the same neighboring terminal group as that of the slave terminal (step 80). After the end of step 78 or 82, the portable terminal 12 determines whether or not the belonging group changing condition is satisfied based on the behavior information of the vehicle and the behavior information of the own terminal (step 86). When the change condition is satisfied, the process returns to step 24 in FIG. 7 to change the group ID of the own terminal to the group ID corresponding to the result of establishment. For example, when the belonging group changing condition from the C group to the B group is satisfied, the own terminal of the C group changes the belonging group to the B group and operates as the mobile terminal 12 of the B group. If the change condition is not satisfied, the master terminal or the slave terminal determines whether or not a predetermined time has elapsed after setting in the belonging group C in step 72 (step 88). If the predetermined time has not elapsed, the process returns to step 74 or 82, and the master terminal continues to transmit / receive presence information to / from the in-vehicle device 10 or the slave terminal as the mobile terminal of the C group. As a portable terminal, it continues to send and receive presence information to and from the master terminal. If the predetermined time has elapsed, the master terminal or the slave terminal shifts to the sleep mode, assuming that there is no vehicle that may cause a collision (step 90). Due to the transition to the sleep mode, the on-board unit transmission wave activation signal reception standby state is entered again.

[Operation of vehicle-mounted device 10]
FIG. 11 is a flow showing the operation of the in-vehicle device 10. The in-vehicle device 10 intermittently transmits an activation signal (step 100). The in-vehicle device 10 acquires the behavior information of the owner included in the terminal transmission wave of the mobile terminal 12 that has received the activation signal (step 102). The in-vehicle device 10 acquires the behavior information of the mobile terminals 12 in the A group from the terminal transmission wave transmitted by each mobile terminal in the A group, and the behavior information of the mobile terminals 12 in the B group and the C group is the master of the group. Acquired from the terminal transmission wave transmitted by the terminal. Then, the in-vehicle device 10 confirms the position of the terminal owner based on the behavior information of the owner of the portable terminal 12, and the owner is in the pedestrian presence information provision area corresponding to the vehicle speed, the blinker information, and the navigation information. It is determined whether or not it exists (step 104). When the vehicle-mounted device 10 determines that the owner of the mobile terminal 12 is present in the pedestrian presence information providing area, the vehicle-mounted device 10 provides the presence information of the owner to the occupant (step 106). The in-vehicle device 10 includes the terminal ID of the mobile terminal 12 in the pedestrian presence information providing area and the vehicle behavior information in order to inform the owner of the mobile terminal 12 in the pedestrian presence information providing area that the vehicle is approaching. Vehicle presence information is transmitted (step 108). Here, the in-vehicle device 10 may provide the passenger with the presence information of the owner based on the risk of collision with the mobile terminal 12. For example, only the presence information of the mobile terminal 12 having a collision risk level equal to or higher than a predetermined level (for example, group A) is provided to the occupant. Thereby, only a portable terminal with high risk of collision can be made to recognize a passenger appropriately. Moreover, as shown in FIG. 6, the in-vehicle device 10 obtains behavior information of all terminals included in the group from the master terminal of each group for the B group and the C group having a relatively low risk level. In addition, the behavior of the entire B group and the entire C group can be captured as vectors of the entire group (the traveling direction vector Db of the B group and the traveling direction vector Dc of the C group). Thereby, the vehicle equipment 10 can provide information corresponding to the behavior of each group as a whole to the passenger and each mobile terminal 12 of each group according to the vector of the entire group.

  As described above, according to the approach notification system, the in-vehicle device 10 and the portable terminal 12, the necessity of notifying each other's approach to the owner of the portable terminal 12 and the driver changes according to the collision risk. Accordingly, by making the communication amount variable, excessive communication and insufficient communication can be avoided. As a result, the occupation frequency of the channel is reduced and the channel can be used efficiently. On the other hand, the power saving effect of the portable terminal 12 increases as the transmission interval of the terminal transmission wave increases. Moreover, the occurrence of congestion can be suppressed.

  Further, according to the above-described communication system, the in-vehicle device 10 and the mobile terminal 12, it is possible to notify only the pedestrian who has the mobile terminal 12 present in the pedestrian presence information providing area of the approach of the vehicle, A pedestrian carrying the mobile terminal 12 existing outside the area can not be notified of the approach of the vehicle. As a result, a pedestrian who needs to be notified of the approach of the vehicle can surely be notified of this, and a pedestrian who does not need much notification of the approach of the vehicle (particularly a position that is not related to the approach of the vehicle (for example, a straight-ahead vehicle) It is possible to reduce the annoyance felt by the pedestrian by the notification to the subject who is in the back).

  Furthermore, according to the above-described approach notification system, the in-vehicle device 10 and the mobile terminal 12, the presence of a pedestrian with respect to the vehicle driver only when there is a pedestrian carrying the mobile terminal 12 in the pedestrian presence information provision area. Information can be provided, and when there is no pedestrian carrying the mobile terminal 12 in the area, it is possible not to provide pedestrian presence information to the vehicle driver. As a result, when there is a pedestrian at a position that should be notified to the vehicle driver during vehicle driving, the vehicle driver can be surely notified of this, and the vehicle driver need not be informed so much. When there are pedestrians, it is possible to reduce the annoyance felt by the driver by providing the pedestrian presence information.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the present invention. Can be added.

  For example, the mobile terminal 12 may perform the collision risk degree calculation, the affiliation group determination, and the communication method determination, instead of the in-vehicle device 10. The in-vehicle device 10 only needs to include means having the same functions as the collision risk calculation unit 13, the belonging group determination unit 14, and the communication method determination unit 15 of the mobile terminal 12 described above. Similarly to the above, the in-vehicle device 10 may transmit / receive the calculation / determination results obtained by these means to / from each portable terminal 12.

  In addition, the mobile terminal 12 that has received the activation signal from the in-vehicle device 10 detects its own position by a GPS device or the like, and transmits the position information to the in-vehicle device 10, so that the in-vehicle device 10 possesses the mobile terminal 12. You may estimate the position of the pedestrian who does. Therefore, the present invention determines whether or not there is a danger based on the relative positional relationship between the pedestrian and the vehicle obtained by the GPS device or the like, and if it is judged as dangerous, the driver of the vehicle or the owner of the portable terminal 12 It is also applicable to a system that provides information to the side.

  Further, the information providing unit 20 of the mobile terminal 12 may specifically notify which vehicle is approaching from which direction as well as the fact of the approach. The information provision part 20 determines the content to alert | report based on the information contained in a vehicle equipment transmission wave.

  The antenna 21 may be a directional antenna having directivity only in one direction in front of the vehicle, or may be a directional antenna having directivity in two directions in front of the vehicle and rear of the vehicle. As a result, even when the vehicle moves backward instead of when the vehicle moves forward, the pedestrian in the backward direction (that is, the traveling direction) can be informed of the presence of the vehicle, and the pedestrian can be notified to the driver. The presence of

  In the above embodiment, the road environment such as the road shape and the number of lanes is acquired based on the navigation information sent from the navigation system. It is good also as acquiring based on communication data by vehicle-to-vehicle communication, road-to-vehicle communication from infrastructure, communication with an information management center).

It is the figure which showed one structure of the approach alerting | reporting system. 2 is a block diagram of a mobile terminal 12. FIG. 2 is a block diagram of the in-vehicle device 10. FIG. It is the figure which showed the positional relationship of the vehicle carrying the vehicle equipment 10 and the holder (pedestrian) of the portable terminal 12. FIG. It is the map which showed the relationship of TTC with respect to relative speed Vr of a vehicle and a pedestrian. It is the map which showed the relationship of TTC with respect to the relative position Pr of a vehicle and a pedestrian. It is the map which showed the relationship of TTC with respect to the pedestrian approach angle (gamma) of cross point Z1 direction. It is the figure which showed the relationship between the vehicle carrying the vehicle equipment 10 and the group to which the portable terminal 12 belongs. It is a flow which shows operation | movement of the portable terminal 12 from starting to affiliation group determination. It is a flow which shows operation | movement of the portable terminal 12 which set the affiliation group to the A group. It is a flow which shows operation | movement of the portable terminal 12 which set the affiliation group to B group. It is a flow which shows operation | movement of the portable terminal 12 which set the affiliation group as C group. It is a flow which shows operation | movement of the vehicle equipment 10. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,21 Antenna 2 Duplexer 10 Vehicle-mounted apparatus 12 Portable terminal 13 Collision risk calculation part 14 Affiliation group determination part 15 Communication system determination part 16 Transmission part 17 Reception part 18 ID addition and detection part 20 Information provision part 22 Circulator 23 Reception part 24 Reception level detection unit 25 Directional distance estimation unit 26 Directivity control unit 27 Information provision determination unit 28 Pedestrian presence information provision area table 29 Information provision unit 30 Transmission unit

Claims (14)

A communication system between the terminal and the in-vehicle device, comprising a terminal device carried by a person and an in-vehicle device mounted on the vehicle,
A collision risk calculating means for calculating a collision risk between the terminal and the vehicle;
The terminal and the in-vehicle device communicate with each other by a communication method in which the communication amount between the terminal and the in-vehicle device is an amount corresponding to the collision risk calculated by the collision risk calculating means. ,Communications system. The communication system according to claim 1,
A communication system comprising notification means for notifying proximity information between the owner of the terminal and the vehicle based on the collision risk calculated by the collision risk calculation means. The communication system according to claim 1 or 2,
The collision risk calculation means calculates the collision risk based on the behavior of the owner of the terminal and the behavior of the vehicle. The communication system according to any one of claims 1 to 3,
The communication system, wherein the communication amount decreases as the collision risk decreases. The communication system according to any one of claims 1 to 3,
A communication system in which a terminal having a lower risk of collision than other terminals communicates with a communication method in which the amount of communication with the in-vehicle device is smaller than that of the other terminals. The communication system according to claim 4 or 5,
Communication between the terminal and the in-vehicle device having the collision risk level equal to or higher than a predetermined level is performed directly,
A communication system in which communication between a terminal having a collision risk level lower than the predetermined level and an in-vehicle device is performed via a representative terminal that is a representative of the terminals constituting the terminal group. The communication system according to claim 6,
A communication system that changes a ratio of a representative terminal in the terminal group to a terminal constituting the terminal group according to the collision risk. The communication system according to claim 6 or 7,
The representative terminal acquires identification information of terminals belonging to the same terminal group as itself and transmits the identification information together with its own identification information to the in-vehicle device,
The in-vehicle device is a communication system that returns identification information of a terminal to be notified of the approach of the vehicle. A terminal that is owned by a person and communicates with an in-vehicle device mounted on a vehicle,
A collision risk acquisition means for acquiring a collision risk between the terminal and the vehicle;
A terminal that communicates with the in-vehicle device by a communication method in which a communication amount between the terminal and the in-vehicle device is an amount corresponding to the collision risk acquired by the collision risk acquiring means. The terminal according to claim 9, wherein
A terminal that informs the owner of the terminal of proximity information to the vehicle based on the collision risk acquired by the collision risk acquisition means. The terminal according to claim 9 or 10, wherein
A terminal that communicates with the in-vehicle device on behalf of another terminal when the collision risk is lower than a predetermined level. The terminal according to any one of claims 9 to 11,
A terminal that changes a communication interval with the in-vehicle device according to the collision risk. An in-vehicle device that is mounted on a vehicle and communicates with a terminal owned by a person,
A collision risk acquisition means for acquiring a collision risk of the terminal and the vehicle;
The in-vehicle device, wherein the communication amount between the terminal and the in-vehicle device communicates with the terminal by a communication method in which the communication amount becomes an amount corresponding to the collision risk acquired by the collision risk acquiring means. The in-vehicle device according to claim 13,
An in-vehicle device that notifies proximity information of the terminal to the vehicle occupant based on the collision risk acquired by the collision risk acquisition means.

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