JP2015195033A - Radio device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide techniques of accurate notification of approach of an emergency vehicle.SOLUTION: A modulating and demodulating section 54 receives, from another terminal device 14, a packet signal including at least position information regarding another vehicle on which the other terminal device 14 is mounted. A position information acquiring section 64 acquires position information regarding the vehicle on which the terminal device 14 is mounted. An estimating section 78 estimates a time taken for the vehicle and the other vehicle to encounter each other on the basis of the two pieces of position information. A deriving section 80 derives a distance between the vehicle and the other vehicle on the basis of the two pieces of position information. A determining section 84 provides notification of the encounter with the other vehicle in a case where the estimated time is equal to or less than a first threshold value or in a case where the derived distance is equal to or less than a second threshold value.

Description

  The present invention relates to communication technology, and more particularly to a radio apparatus that receives a signal including predetermined information.

  The emergency vehicle passage support service prompts the driver to perform an avoidance action for passing the emergency vehicle when the vehicle approaches the emergency vehicle. The approach of the emergency vehicle is predicted by calculation using the speed, position, and traveling direction of both vehicles (see, for example, Patent Document 1).

International Publication No. 11/013238 Pamphlet

  Until now, driving support has been provided when the vehicle and the emergency vehicle are in a positional relationship and the time until the vehicle and the emergency vehicle meet is within a predetermined time. However, when the relative speed of the vehicle and the emergency vehicle is low, there is a possibility that no assistance is generated even though the vehicle and the emergency vehicle are approaching.

  This invention is made | formed in view of such a condition, The objective is to provide the technique of notifying the approach of an emergency vehicle correctly.

  In order to solve the above problems, a wireless device according to an aspect of the present invention is a wireless device that can be mounted on a vehicle, is a packet signal from another wireless device, and is mounted with the other wireless device. A receiving unit that receives at least a packet signal including position information of another vehicle, an acquisition unit that acquires position information of a vehicle on which the wireless device is mounted, position information acquired by the acquisition unit, and a receiving unit Based on the position information included in the received packet signal, an estimation unit that estimates the time until the vehicle and another vehicle meet, the position information acquired by the acquisition unit, and the packet received by the reception unit A deriving unit for deriving a distance between the vehicle and another vehicle based on the position information included in the signal, and a case in which the time estimated by the estimating unit is equal to or less than the first threshold value, or the deriving unit Derived in If distance is less than or equal to the second threshold value, comprising a determination unit that notifies the encounter with another vehicle, a.

  It should be noted that any combination of the above-described constituent elements and a conversion of the expression of the present invention between a method, an apparatus, a system, a recording medium, a computer program, etc. are also effective as an aspect of the present invention.

  According to the present invention, it is possible to accurately notify the approach of an emergency vehicle.

It is a figure which shows the structure of the communication system which concerns on Example 1 of this invention. It is a figure which shows the structure of the base station apparatus of FIG. FIGS. 3A to 3D are diagrams showing frame formats defined in the communication system of FIG. It is a figure which shows the structure of the terminal device of FIG. It is a figure which shows the process outline | summary by the communication system of FIG. It is a figure which shows the data structure of the table hold | maintained at the determination part of FIG. It is a flowchart which shows the determination procedure by the terminal device of FIG. It is a flowchart which shows the derivation | leading-out procedure of the distance by the terminal device of FIG. It is a figure which shows the data structure of the table hold | maintained at the determination part which concerns on Example 2 of this invention. It is a figure which shows the data structure of the table hold | maintained at the determination part which concerns on Example 3 of this invention. It is a figure which shows the information contained in the packet signal which concerns on Example 4 of this invention. It is a figure which shows the information contained in the packet signal which concerns on Example 5 of this invention. It is a figure which shows the information contained in the packet signal which concerns on Example 6 of this invention. It is a flowchart which shows the determination procedure by the terminal device which concerns on Example 6 of this invention. It is a flowchart which shows the determination procedure by the terminal device which concerns on Example 7 of this invention. FIGS. 16A and 16B are diagrams illustrating the configuration of the communication system according to the eighth embodiment of the present invention. It is a flowchart which shows the determination procedure by the terminal device which concerns on Example 8 of this invention.

(Example 1)
Prior to specific description of the embodiments of the present invention, the underlying knowledge will be described. Embodiment 1 of the present invention relates to a communication system that executes vehicle-to-vehicle communication between terminal devices mounted on a vehicle and also executes road-to-vehicle communication from a base station device installed at an intersection or the like to a terminal device. Such a communication system is also called ITS (Intelligent Transport Systems). The communication system uses an access control function called CSMA / CA (Carrier Sense Multiple Access Collision Aviation), as well as a wireless LAN (Local Area Network) compliant with a standard such as IEEE 802.11. Therefore, the same radio channel is shared by a plurality of terminal devices. On the other hand, in ITS, it is necessary to transmit information to an unspecified number of terminal devices. In order to efficiently perform such transmission, the communication system broadcasts a packet signal.

  That is, as inter-vehicle communication, the terminal device broadcasts a packet signal that stores information such as the speed or position of the vehicle. In addition, the other terminal device receives the packet signal and recognizes the approach of the vehicle based on the above-described information. Here, in order to reduce interference between road-vehicle communication and vehicle-to-vehicle communication, the base station apparatus repeatedly defines a frame including a plurality of subframes. The base station apparatus selects any of a plurality of subframes for road-to-vehicle communication, and broadcasts a packet signal in which control information and the like are stored during the period of the head portion of the selected subframe.

  The control information includes information related to a period for the base station apparatus to broadcast the packet signal (hereinafter referred to as “road vehicle transmission period”). The terminal device specifies a road and vehicle transmission period based on the control information, and broadcasts a packet signal by the CSMA method in a period other than the road and vehicle transmission period (hereinafter referred to as “vehicle transmission period”). As a result, road-to-vehicle communication and vehicle-to-vehicle communication are time-division multiplexed. Note that a terminal device that cannot receive control information from the base station device, that is, a terminal device that exists outside the area formed by the base station device transmits a packet signal by the CSMA method regardless of the frame configuration.

  The terminal device receives a packet signal from another terminal device, and is information related to an existing position included in the packet signal and is based on information related to an existing position of another vehicle on which the other terminal device is mounted. In addition, the approach of another vehicle is detected. When the terminal device detects the approach of another vehicle, it notifies the driver to that effect. In addition to this, in the emergency vehicle passage support, when the vehicle is likely to approach the emergency vehicle, the driver is notified to that effect. More specifically, in the emergency vehicle passage support, provision of information is specified when the linear distance between the main vehicle and the emergency vehicle is within 300 m. For example, the presence of an emergency vehicle is notified by displaying an icon of the emergency vehicle at a position where the emergency vehicle exists on a map of a car navigation system mounted on the vehicle.

  Furthermore, emergency vehicle approach information is provided when the vehicle and the emergency vehicle encounter (intersection, passing, overtaking) in order to make assistance to the driver more effective. For example, the approach of an emergency vehicle is notified by displaying on the car navigation system an icon that is more emphasized than the icon described above and the direction in which the emergency vehicle approaches (from the rear, from the front, from the right, from the left, etc.). The Here, we focus on the timing of such support.

  Information is provided to the driver when it is determined that the vehicle and the emergency vehicle meet within a predetermined time according to the position, speed, and traveling direction of the vehicle and the emergency vehicle. In such a process, as described above, when the relative speed between the present vehicle and the emergency vehicle is low, there is a possibility that no assistance is generated even though the present vehicle and the emergency vehicle are approaching. To cope with this, the terminal device according to the present embodiment provides information to the driver when the occurrence of the encounter is later than a predetermined time and the distance between the vehicle and the emergency vehicle is equal to or less than the predetermined distance. Do.

  FIG. 1 shows a configuration of a communication system 100 according to Embodiment 1 of the present invention. This corresponds to a case where one intersection is viewed from above. The communication system 100 includes a base station device 10, a first vehicle 12a, a second vehicle 12b, a third vehicle 12c, a fourth vehicle 12d, a fifth vehicle 12e, a sixth vehicle 12f, and a seventh vehicle 12g, collectively referred to as a vehicle 12. , The eighth vehicle 12h, and the network 202. Here, only the first vehicle 12 a is shown, but each vehicle 12 is equipped with a terminal device 14. An area 212 is formed around the base station apparatus 10, and an outside area 214 is formed outside the area 212.

  As shown in the drawing, the road that goes in the horizontal direction of the drawing, that is, the left and right direction, intersects the vertical direction of the drawing, that is, the road that goes in the up and down direction, at the center. Here, the upper side of the drawing corresponds to the direction “north”, the left side corresponds to the direction “west”, the lower side corresponds to the direction “south”, and the right side corresponds to the direction “east”. The intersection of the two roads is an “intersection”. The first vehicle 12a and the second vehicle 12b are traveling from left to right, and the third vehicle 12c and the fourth vehicle 12d are traveling from right to left. Further, the fifth vehicle 12e and the sixth vehicle 12f are traveling from the top to the bottom, and the seventh vehicle 12g and the eighth vehicle 12h are traveling from the bottom to the top.

  In the communication system 100, the base station apparatus 10 is fixedly installed at an intersection. The base station device 10 controls communication between terminal devices. The base station apparatus 10 receives a frame including a plurality of subframes based on a signal received from a GPS (Global Positioning System) satellite (not shown) or a frame formed by another base station apparatus 10 (not shown). Generate repeatedly. Here, the road vehicle transmission period can be set at the head of each subframe.

  The base station apparatus 10 selects a subframe in which the road and vehicle transmission period is not set by another base station apparatus 10 from among a plurality of subframes in the frame. The base station apparatus 10 sets a road and vehicle transmission period at the beginning of the selected subframe. The base station apparatus 10 notifies the packet signal in the set road and vehicle transmission period. In the road and vehicle transmission period, a plurality of packet signals may be notified. The packet signal includes, for example, accident information, traffic jam information, signal information, and the like. Note that the packet signal also includes information related to the timing when the road and vehicle transmission period is set and control information related to the frame.

  As described above, the terminal device 14 is mounted on the vehicle 12 and is movable. When receiving the packet signal from the base station apparatus 10, the terminal apparatus 14 estimates that the terminal apparatus 14 exists in the area 212. When the terminal device 14 exists in the area 212, the terminal device 14 generates a frame based on the control information included in the packet signal, in particular, the information on the timing when the road and vehicle transmission period is set and the information on the frame. As a result, the frame generated in each of the plurality of terminal devices 14 is synchronized with the frame generated in the base station device 10. The terminal device 14 notifies the packet signal in the vehicle transmission period that is a period different from the road and vehicle transmission period. Here, CSMA / CA is executed in the vehicle transmission period. On the other hand, when it is estimated that the terminal apparatus 14 exists outside the area 214, the terminal apparatus 14 notifies the packet signal by executing CSMA / CA regardless of the frame configuration.

  The terminal device 14 recognizes the approach of the vehicle 12 on which the other terminal device 14 is mounted based on the packet signal from the other terminal device 14. In particular, when one of the vehicles 12, for example, the first vehicle 12a is the main vehicle and the other one, for example, the eighth vehicle 12h is an emergency vehicle, the terminal device 14 mounted on the first vehicle 12a is Notify you of encounters with emergency vehicles.

  FIG. 2 shows the configuration of the base station apparatus 10. The base station apparatus 10 includes an antenna 20, an RF unit 22, a modem unit 24, a processing unit 26, a control unit 28, and a network communication unit 30. Further, the processing unit 26 includes a frame defining unit 32, a selecting unit 34, and a generating unit 36.

  The RF unit 22 receives a packet signal from a terminal device 14 (not shown) or another base station device 10 by the antenna 20 as a reception process. The RF unit 22 performs frequency conversion on the received radio frequency packet signal to generate a baseband packet signal. Further, the RF unit 22 outputs a baseband packet signal to the modem unit 24. In general, baseband packet signals are formed by in-phase and quadrature components, so two signal lines should be shown, but here only one signal line is shown for clarity. Shall be shown. The RF unit 22 includes an LNA (Low Noise Amplifier), a mixer, an AGC, and an A / D conversion unit.

  As a transmission process, the RF unit 22 performs frequency conversion on the baseband packet signal input from the modem unit 24 to generate a radio frequency packet signal. Further, the RF unit 22 transmits a radio frequency packet signal from the antenna 20 during the road-vehicle transmission period. The RF unit 22 also includes a PA (Power Amplifier), a mixer, and a D / A conversion unit.

  The modem unit 24 demodulates the baseband packet signal from the RF unit 22 as a reception process. Further, the modem unit 24 outputs the demodulated result to the processing unit 26. The modem unit 24 also modulates the data from the processing unit 26 as a transmission process. Further, the modem unit 24 outputs the modulated result to the RF unit 22 as a baseband packet signal. Here, since the communication system 100 corresponds to an OFDM (Orthogonal Frequency Division Multiplexing) modulation scheme, the modem unit 24 also performs FFT (Fast Fourier Transform) as reception processing and IFFT (Inverse Fast Forward) as transmission processing. Also execute.

  The frame defining unit 32 receives a signal from a GPS satellite (not shown), and acquires time information based on the received signal. In addition, since a well-known technique should just be used for acquisition of the information of time, description is abbreviate | omitted here. The frame defining unit 32 generates a plurality of frames based on the time information. For example, the frame defining unit 32 generates ten “100 msec” frames by dividing the “1 sec” period into ten on the basis of the timing indicated by the time information. By repeating such processing, the frame is defined to be repeated. The frame defining unit 32 may detect control information from the demodulation result and generate a frame based on the detected control information. Such processing corresponds to generating a frame synchronized with the timing of the frame formed by another base station apparatus 10.

  3A to 3D show frame formats defined in the communication system 100. FIG. FIG. 3A shows the structure of the frame. The frame is formed of N subframes indicated as the first subframe to the Nth subframe. This can be said that the terminal device 14 forms a frame by multiplexing a plurality of subframes that can be used for notification for a plurality of hours. For example, when the frame length is 100 msec and N is 8, a subframe having a length of 12.5 msec is defined. N may be other than 8. The description of FIGS. 3B to 3D will be described later and returns to FIG.

  The selection part 34 selects the sub-frame which should set a road and vehicle transmission period among several sub-frames contained in the flame | frame. More specifically, the selection unit 34 receives a frame defined by the frame defining unit 32. The selection unit 34 receives an instruction regarding the selected subframe via an interface (not shown). The selection unit 34 selects a subframe corresponding to the instruction. Apart from this, the selection unit 34 may automatically select a subframe. At this time, the selection unit 34 inputs a demodulation result from another base station device 10 or the terminal device 14 (not shown) via the RF unit 22 and the modem unit 24. The selection part 34 extracts the demodulation result from the other base station apparatus 10 among the input demodulation results. The selection unit 34 specifies the subframe that has not received the demodulation result by specifying the subframe that has received the demodulation result.

  This corresponds to specifying a subframe in which the road and vehicle transmission period is not set by another base station apparatus 10, that is, an unused subframe. When there are a plurality of unused subframes, the selection unit 34 selects one subframe at random. When there are no unused subframes, that is, when each of a plurality of subframes is used, the selection unit 34 acquires reception power corresponding to the demodulation result, and gives priority to subframes with low reception power. Select

  FIG. 3B shows a configuration of a frame generated by the first base station apparatus 10a (not shown). The first base station apparatus 10a sets a road and vehicle transmission period at the beginning of the first subframe. Moreover, the 1st base station apparatus 10a sets a vehicle transmission period following the road and vehicle transmission period in a 1st sub-frame. The vehicle transmission period is a period during which the terminal device 14 can notify the packet signal. That is, the first base station apparatus 10a can notify the packet signal in the road and vehicle transmission period which is the first period of the first subframe, and the terminal apparatus in the vehicle and vehicle transmission period other than the road and vehicle transmission period in the frame. It is specified that 14 can broadcast the packet signal. Furthermore, the first base station apparatus 10a sets only the vehicle transmission period from the second subframe to the Nth subframe.

  FIG. 3C shows a configuration of a frame generated by the second base station apparatus 10b (not shown). The second base station apparatus 10b sets a road and vehicle transmission period at the beginning of the second subframe. Also, the second base station apparatus 10b sets the vehicle transmission period from the first stage of the road and vehicle transmission period in the second subframe, from the first subframe and the third subframe to the Nth subframe. FIG. 3D shows a configuration of a frame generated by a third base station apparatus 10c (not shown). The third base station apparatus 10c sets a road and vehicle transmission period at the beginning of the third subframe. In addition, the third base station apparatus 10c sets the vehicle transmission period from the first stage of the road and vehicle transmission period in the third subframe, the first subframe, the second subframe, and the fourth subframe to the Nth subframe. As described above, the plurality of base station apparatuses 10 select different subframes, and set the road and vehicle transmission period at the head portion of the selected subframe. Returning to FIG. The selection unit 34 outputs the selected subframe number to the generation unit 36.

  The generation unit 36 receives a subframe number from the selection unit 34. The generation unit 36 sets a road and vehicle transmission period in the subframe of the received subframe number, and generates a packet signal to be notified during the road and vehicle transmission period. When a plurality of packet signals are transmitted in one road and vehicle transmission period, the generation unit 36 generates them. The packet signal is composed of control information and a payload. The control information includes a subframe number in which a road and vehicle transmission period is set. The payload includes, for example, accident information, traffic jam information, signal information, and the like. These data are acquired from the network 202 (not shown) by the network communication unit 30. The processing unit 26 broadcasts the packet signal to the modem unit 24 and the RF unit 22 during the road and vehicle transmission period. The control unit 28 controls processing of the entire base station device 10.

  This configuration can be realized in terms of hardware by a CPU, memory, or other LSI of any computer, and in terms of software, it can be realized by a program loaded in the memory, but here it is realized by their cooperation. Draw functional blocks. Accordingly, those skilled in the art will understand that these functional blocks can be realized in various forms only by hardware, or by a combination of hardware and software.

  FIG. 4 shows the configuration of the terminal device 14. The terminal device 14 includes an antenna 50, an RF unit 52, a modem unit 54, a processing unit 56, and a control unit 58. The processing unit 56 includes a timing specifying unit 60, a transfer determining unit 62, a position information acquiring unit 64, a generating unit 66, a state determining unit 76, and a notification unit 70. The timing specifying unit 60 includes an extracting unit 72, a carrier sense unit 74. including. The state determination unit 76 includes an estimation unit 78, a derivation unit 80, a storage unit 82, and a determination unit 84. The terminal device 14 can be mounted on the vehicle 12 as described above. The vehicle 12 may be an emergency vehicle. The antenna 50, the RF unit 52, and the modem unit 54 execute the same processing as the antenna 20, the RF unit 22, and the modem unit 24 in FIG. Here, the difference will be mainly described.

  The modem unit 54 and the processing unit 56 receive a packet signal from another terminal device 14 or the base station device 10 (not shown) in the reception process. As described above, the modem unit 54 and the processing unit 56 receive a packet signal from the base station apparatus 10 during the road-to-vehicle transmission period, and receive packet signals from other terminal apparatuses 14 during the vehicle-to-vehicle transmission period. To do. The packet signal from the other terminal device 14 includes at least the presence position, traveling direction, moving speed, etc. (hereinafter collectively referred to as “position information”) of the other vehicle 12 on which the other terminal device 14 is mounted. It is. Since a known technique may be used for acquiring the position information in the other terminal device 14, the description thereof is omitted here.

  The packet signal includes type information for indicating the type of the vehicle 12 on which the terminal device 14 is mounted. In particular, when the other vehicle 12 is an emergency vehicle, the type information included in the packet signal transmitted from the other terminal device 14 mounted on the emergency vehicle indicates the emergency vehicle.

  When the demodulation result from the modem unit 54 is a packet signal from the base station apparatus 10 (not shown), the extraction unit 72 specifies the timing of the subframe in which the road and vehicle transmission period is arranged. In that case, the extraction part 72 estimates that it exists in the area 212 of FIG. The extraction unit 72 generates a frame based on the timing of the subframe and the content of the message header of the packet signal, specifically, the content of the road and vehicle transmission period length. Note that the generation of the frame only needs to be performed in the same manner as the frame defining unit 32 described above, and thus the description thereof is omitted here. As a result, the extraction unit 72 generates a frame synchronized with the frame formed in the base station device 10. When the notification source of the packet signal is another terminal device 14, the extraction unit 72 extracts the position information and the type information included in the packet signal, although the synchronized frame generation process is omitted. Here, since emergency vehicle passage support is an object of explanation, hereinafter, the type information indicates an emergency vehicle. The extraction unit 72 outputs emergency vehicle position information to the state determination unit 76.

  On the other hand, when the extraction unit 72 has not received a packet signal from the base station apparatus 10, the extraction unit 72 estimates that the extraction unit 72 exists outside the area 214 in FIG. When it is estimated that the extraction unit 72 exists in the area 212, the extraction unit 72 selects the vehicle transmission period. When it is estimated that the extraction unit 72 exists outside the area 214, the extraction unit 72 selects a timing unrelated to the frame configuration. When the vehicle transmission period is selected, the extraction unit 72 outputs information on the frame and subframe timing and the vehicle transmission period to the carrier sense unit 74. When selecting the timing unrelated to the frame configuration, the extraction unit 72 instructs the carrier sense unit 74 to execute carrier sense.

  The carrier sense unit 74 receives information about the timing of the frames and subframes and the vehicle transmission period from the extraction unit 72. The carrier sense unit 74 determines the transmission timing by starting CSMA / CA within the vehicle transmission period. On the other hand, when the carrier sense unit 74 is instructed by the extraction unit 72 to execute carrier sense not related to the frame configuration, the carrier sense unit 74 performs transmission timing by executing CSMA / CA without considering the frame configuration. To decide. The carrier sense unit 74 notifies the modem unit 54 and the RF unit 52 of the determined transmission timing, and broadcasts the packet signal.

  The transfer determination unit 62 controls transfer of control information. The transfer determination unit 62 extracts information to be transferred from the control information. The transfer determination unit 62 generates information to be transferred based on the extracted information. Here, the description of this process is omitted. The transfer determination unit 62 outputs information to be transferred, that is, a part of the control information, to the generation unit 66.

  The position information acquisition unit 64 includes a GPS receiver, a gyroscope, a vehicle speed sensor, and the like (not shown), and the presence position of the vehicle 12 (not shown), that is, the vehicle 12 on which the terminal device 14 is mounted, by data supplied from them. The traveling direction, the moving speed, and the like (collectively referred to as “position information” as described above) are acquired. The existence position is indicated by latitude and longitude. Since a known technique may be used for these acquisitions, description thereof is omitted here. The position information acquisition unit 64 outputs the position information to the generation unit 66 and the state determination unit 76.

  The generation unit 66 receives position information from the position information acquisition unit 64 and receives part of the control information from the transfer determination unit 62. The generation unit 66 generates a packet signal including these, and broadcasts the generated packet signal via the modem unit 54, the RF unit 52, and the antenna 50 at the transmission timing determined by the carrier sense unit 74. To do. This corresponds to inter-vehicle communication. Further, the generation unit 66 includes type information in the packet signal, and the type information here indicates, for example, a general vehicle.

  The estimation unit 78 receives position information from the transfer determination unit 62 and also receives position information from the extraction unit 72. The estimation unit 78 estimates the time until the main vehicle 12 and the emergency vehicle meet based on the position information of the emergency vehicle and the position information of the main vehicle 12. A known technique may be used for time estimation. For example, as a first stage, the estimation unit 78 estimates whether to encounter each other based on the presence position and the traveling direction of both. In the second stage, the estimation unit 78 estimates an encounter time based on the moving speed when it is estimated that the encounter will occur. The estimation unit 78 outputs the estimated time to the determination unit 84.

  The storage unit 82 stores road information of a road on which the vehicle 12 is traveling. The road information includes intersection position information. Road information is a known technique. Further, the road information may be stored in a car navigation system mounted on the vehicle 12 without being stored in the terminal device 14. Similarly to the estimation unit 78, the deriving unit 80 receives position information from the transfer determination unit 62 and also receives position information from the extraction unit 72. The deriving unit 80 derives the distance between the main vehicle and the emergency vehicle based on the position information of the emergency vehicle and the position information of the main vehicle 12. Here, the deriving unit 80 may derive a straight-line distance between the vehicle and the emergency vehicle, and also uses the road information stored in the storage unit 82 so as to determine the distance between the vehicle and the emergency vehicle. May be derived.

  In addition, the deriving unit 80 derives the journey distance, and when there is an intersection between the two, instead of the distance between the present vehicle and the emergency vehicle, the present position of the present vehicle and the intersection Based on the location, the distance between the vehicle and the intersection is derived. This is a case where the vehicle and the emergency vehicle are in a positional relationship of facing and following traveling, and when the vehicle and the emergency vehicle cross each other, the distance between the vehicle and the emergency vehicle is determined as the distance between the vehicle and the emergency vehicle. Equivalent to the distance to the intersection. FIG. 5 shows an outline of processing by the communication system 100. The vehicle 12 in the figure corresponds to the main vehicle, and is traveling from the bottom to the top, and the emergency vehicle 16 is traveling from the left to the right. Since the traveling directions of the two intersect at an intersection, the location of the emergency vehicle 16 is assumed to be the location of the virtual emergency vehicle 18. The deriving unit 80 derives the distance between the vehicle 12 and the virtual emergency vehicle 18. Returning to FIG. By such processing, the distance between the main vehicle and the emergency vehicle is made shorter than the actual distance. The deriving unit 80 outputs the derived distance to the determining unit 84.

  The determination unit 84 receives time from the estimation unit 78 and receives a distance from the derivation unit 80. The determination unit 84 determines that an emergency vehicle is encountered when the time estimated by the estimation unit 78 is less than or equal to the first threshold value or when the distance derived by the derivation unit 80 is less than or equal to the second threshold value. In cases other than these, the determination unit 84 determines that the vehicle is not encountered with the emergency vehicle. The first threshold value and the second threshold value are predetermined by simulation calculation or experiment. FIG. 6 shows the data structure of the table held in the determination unit 84. As illustrated, a condition column 300 and a status column 302 are included. When the condition shown in the condition column 300 is satisfied, the state shown in the state column 302 is determined. Further, the approach corresponds to the aforementioned encounter, and the non-approach corresponds to the aforementioned non-encounter.

  This means that if the time to encounter is less than or equal to the first threshold, assistance occurs and even if the time to encounter is longer than the first threshold, the distance between them is within the second threshold This corresponds to the occurrence of support in this area. Furthermore, support is generated in the area where the distance between the two is within the second threshold, and even if the distance between the both is not within the second threshold, the time until the encounter is less than the first threshold If this is the case, it corresponds to the occurrence of support. Returning to FIG.

  The notification unit 70 displays the contents of the received packet signal on a display (not shown) or the like. The notification unit 70 inputs the determination result from the determination unit 84. The notification unit 70 notifies the determination result to the driver via a monitor or a speaker. Furthermore, the notification unit 70 also notifies the driver of information included in the packet signal from the base station device 10 via a monitor or a speaker.

  The operation of the communication system 100 configured as above will be described. FIG. 7 is a flowchart illustrating a determination procedure performed by the terminal device 14. The estimation unit 78 estimates time (S10). The deriving unit 80 derives the distance (S12). If the time is equal to or less than the first threshold value (Y in S14), the determination unit 84 determines that it is approaching (S20). Even if the time is not less than or equal to the first threshold value (N in S14), if the distance is less than or equal to the second threshold value (Y in S16), the determination unit 84 determines that it is approaching (S20). If the distance is not less than or equal to the second threshold value (N in S16), the determination unit 84 determines that it is not approaching (S18).

  FIG. 8 is a flowchart illustrating a distance deriving procedure by the terminal device 14. If there is an intersection between the vehicle 12 and the emergency vehicle (Y in S40), the determination unit 84 changes the position of the emergency vehicle to the position of the intersection (S42). On the other hand, if there is no intersection between the vehicle 12 and the emergency vehicle (N in S40), step 42 is skipped. The deriving unit 80 derives the distance (S44).

  According to the embodiment of the present invention, since an encounter is notified based on the time until the emergency vehicle is encountered and the distance from the emergency vehicle, it is possible to accurately notify the approach of the emergency vehicle. In addition, since the presence / absence of an encounter is determined by the logical sum of two conditions such as time and distance, each condition can be made stricter. Moreover, since each condition becomes severe, erroneous determination can be reduced. Also, if there is an intersection with the emergency vehicle, the distance to the emergency vehicle is shortened, so the possibility of notification can be improved.

(Example 2)
Next, a second embodiment of the present invention will be described. As in the first embodiment, the second embodiment also relates to a communication system that performs emergency vehicle passage assistance. In the first embodiment, whether or not the vehicle is approaching is determined by comparing the time with the first threshold value and the distance with the second threshold value. In particular, the first threshold value and the second threshold value are fixed values. The terminal device according to the second embodiment changes the first threshold value and the second threshold value according to the direction in which the emergency vehicle approaches. For example, when an emergency vehicle approaches from behind, since it is necessary to pay attention to the rear, it is likely to be unsafe driving than usual. For this reason, it is necessary to accelerate the determination of approach and the generation of support. Further, when the emergency vehicle approaches from the front, the movement of the line of sight is small, so the influence on driving is small. For this reason, it is possible to delay the determination of approach and to generate support more slowly than when approaching from behind. Furthermore, when the vehicle intersects with an emergency vehicle, it is difficult to visually recognize the emergency vehicle, which may result in sudden braking. For this reason, it is necessary to accelerate the determination of approach and the generation of support. The communication system 100 according to the second embodiment is the same type as that in FIG. 1, the base station apparatus 10 according to the second embodiment is the same type as that in FIG. 2, and the terminal apparatus 14 according to the second embodiment is This is the same type as 4, and here, the difference will be mainly described.

  4 compares the presence position and the traveling direction in the position information from the positional information acquisition unit 64 with the presence position and the traveling direction in the position information from the extraction unit 72. The determination unit 84 estimates a relative direction when encountering an emergency vehicle. Here, the traveling direction of the vehicle 12 is defined as 0 degrees, and coordinates where the angle increases clockwise are defined. At that time, 90 degrees corresponds to the right, 180 degrees corresponds to the back, 270 degrees corresponds to the left, and 360 degrees corresponds to 0 degrees. For example, the determination unit 84 defines 350 degrees to 360 degrees, 0 degrees to 10 degrees as the front area, and 170 degrees to 190 degrees as the rear area. Further, the determination unit 84 derives the relative direction based on the angle in such a coordinate system. The determination unit 84 specifies “approach from the front” when the relative direction is included in the front area, and specifies “approach from the rear” when the relative direction is included in the rear area. Further, the determination unit 84 also specifies “approaching at a front intersection” based on the road information stored in the storage unit 82, similarly to the above-described derivation unit 80.

  The determination unit 84 adjusts the first threshold value and the second threshold value according to the specified content. FIG. 9 shows a data structure of a table held in the determination unit 84 according to the second embodiment of the present invention. As illustrated, a condition column 310 and a processing column 312 are included. When the condition shown in the condition column 310 is satisfied, the determination unit 84 changes the first threshold value and the second threshold value as shown in the processing column 312. Returning to FIG. As the first threshold value and the second threshold value become smaller, it becomes more difficult to detect the approach of the emergency vehicle, and as the first threshold value and the second threshold value become larger, the approach of the emergency vehicle becomes easier to detect.

  According to the embodiment of the present invention, since the first threshold value and the second threshold value are adjusted according to the relative direction, notification according to the situation can be executed. Moreover, when approaching from the front, the first threshold value and the second threshold value are reduced, so that it is difficult to detect the approach of the emergency vehicle. Moreover, since the approach of an emergency vehicle becomes difficult to be detected, generation | occurrence | production of an unnecessary notification can be suppressed. Further, when approaching from behind or approaching at a front intersection, the first threshold value and the second threshold value are increased, so that the approach of the emergency vehicle can be easily detected. Moreover, since the approach of the emergency vehicle is easily detected, the driver can be alerted.

(Example 3)
Next, a third embodiment of the present invention will be described. As in the first embodiment, the third embodiment also relates to changing the first threshold value and the second threshold value. When the light color of the front signal where the vehicle is traveling is blue, if the recognition of the approach of the emergency vehicle is delayed, sudden braking before the intersection is required. In the third embodiment, when the vehicle and the emergency vehicle intersect, when the intersection prediction point is the intersection and the traveling direction signal of the vehicle is “blue”, the timing for generating the support is made earlier. The first threshold value and the second threshold value are changed. The communication system 100 according to the third embodiment is the same type as that shown in FIG. 1, the base station device 10 according to the third embodiment is the same type as that shown in FIG. 2, and the terminal device 14 according to the third embodiment is shown in FIG. This is the same type as 4, and here, the difference will be mainly described.

  As described above, the modem unit 54 and the processing unit 56 in FIG. 4 receive the packet signal from the base station apparatus 10. The packet signal is associated with information on the light color of a traffic light installed at an intersection or the like (hereinafter referred to as “light color information”) and information for identifying the traffic light (hereinafter referred to as “traffic signal information”). While included. In the lamp color information, “red”, “yellow”, and “blue” are indicated, and “a schedule for changing the lamp color” is indicated. In addition, the traffic signal information includes information on the position where the traffic signal is installed, or includes identification information for identifying the traffic signal. The extraction unit 72 extracts lamp color information and traffic signal information from the packet signal, and outputs them to the determination unit 84. That is, the extraction unit 72 receives the light color information of the traffic light installed in the traveling direction of the vehicle 12.

  The determination unit 84 receives the lamp color information and the traffic signal information from the extraction unit 72. Based on the traffic signal information, the determination unit 84 determines whether the traffic signal corresponding to the traffic signal information is a traffic signal to be passed. Therefore, when the traffic signal information includes position information, it is used. When the traffic signal information includes identification information, the position is specified based on the identification information, and the specified position is used. The In addition, in order to specify the position based on the identification information, a table in which these are associated is stored in the determination unit 84 in advance. When the determination unit 84 determines that the traffic light is to pass from now on, the determination unit 84 specifies the lamp color indicated by the lamp color information.

  FIG. 10 shows a data structure of a table held in the determination unit 84 according to the third embodiment of the present invention. As shown, a condition column 320 and a processing column 322 are shown. When the condition indicated in the condition column 320 is indicated, the processing indicated in the processing column 322 is performed. Returning to FIG. The determination unit 84 increases the first threshold value and the second threshold value when the lamp color is blue. That is, the determination unit 84 adjusts the first threshold value and the second threshold value according to the lamp color information. In the emergency vehicle, signal information of the intersection on the emergency vehicle route may be acquired, and the information may be added to the packet signal and transmitted. At this time, the vehicle side determines whether it intersects or is in the same direction with respect to the route of the emergency vehicle, and determines the signal light color on the route side of the vehicle.

  According to the embodiment of the present invention, since the first threshold value and the second threshold value are adjusted according to the lamp color, notification according to the lamp color can be executed. In the case of blue, since the first threshold value and the second threshold value are increased, the possibility of notification can be increased. In addition, since the possibility of notification increases, safety can be improved.

Example 4
Next, a fourth embodiment of the present invention will be described. The fourth embodiment relates to communication between the terminal device mounted on the emergency vehicle and the terminal device mounted on the vehicle, as before. When an emergency vehicle passes through an intersection, if the light color in the traveling direction is red, the danger increases compared to when it is blue. The fourth embodiment aims to reduce the risk of collision when an emergency vehicle enters an intersection whose light color is red. The terminal device according to the fourth embodiment, particularly the terminal device mounted on the emergency vehicle, is shown to be approaching with a red signal when the emergency vehicle enters the intersection and the signal on the approach side direction is red. Information (hereinafter referred to as “red signal entering information”) is included in the packet signal and transmitted. The communication system 100 according to the fourth embodiment is the same type as that in FIG. 1, the base station apparatus 10 according to the fourth embodiment is the same type as that in FIG. 2, and the terminal apparatus 14 according to the fourth embodiment is This is the same type as 4, and here, the difference will be mainly described.

  The terminal device 14 shown in FIG. 4, in particular, the modem unit 54 and the processing unit 56 of the terminal device 14 mounted in an emergency vehicle, as in the third embodiment, are packet signals including lamp color information and traffic signal information. Is received from the base station apparatus 10. The extraction unit 72 extracts lamp color information and traffic signal information from the packet signal, and outputs them to the generation unit 66. The generation unit 66 receives the lamp color information and the traffic signal information from the extraction unit 72. Based on the traffic signal information, the generation unit 66 determines whether the traffic signal corresponding to the traffic signal information is a traffic signal to be passed. This is the same as the processing performed in the determination unit 84 of the third embodiment. When the generation unit 66 determines that the traffic signal is to be passed from now on, the generation unit 66 specifies the lamp color indicated by the lamp color information. When the specified lamp color is red, the generation unit 66 inserts red signal approaching information into the packet signal. FIG. 11 shows information included in a packet signal according to the fourth embodiment of the present invention. As shown in the figure, the “incoming red signal” information is included in the packet signal.

  The modem unit 54 and the processing unit 56 of the terminal device 14 illustrated in FIG. 4, particularly the terminal device 14 mounted on the vehicle 12 other than the emergency vehicle, receive packet signals from the terminal device 14 mounted on the emergency vehicle. . The extraction unit 72 extracts red signal approaching information from the packet signal. The extraction unit 72 outputs red signal approaching information to the notification unit 70. The notification unit 70 notifies the driver that the emergency vehicle enters the intersection even if the signal is a red signal based on the red signal approaching information.

  According to the embodiment of the present invention, since the red signal approaching information is included in the packet signal, it is possible to notify the driver of the surrounding vehicle even when entering the intersection with the red signal. In addition, since the driver of the surrounding vehicle is notified of the approach to the intersection with a red light, the possibility of a collision accident can be reduced.

(Example 5)
Next, a fifth embodiment of the present invention will be described. The fifth embodiment relates to communication between the terminal device mounted on the emergency vehicle and the terminal device mounted on the vehicle, as before. In particular, a case where a field emergency support system (FAST) is executed is targeted. The on-site express support system is a system that performs signal control for preferentially driving an emergency vehicle, and is a system aimed at shortening the time to arrive at the site and preventing traffic accidents caused by emergency driving. For example, optical beacons (optical vehicle detectors) installed before and after an intersection are used in the field express support system. Specifically, when an emergency vehicle equipped with a transmitter travels urgently, a receiver installed on the road senses this. The result is transmitted to the traffic control center, and the red light in the direction of travel of the vehicle is shortened or the green light is extended.

  However, when the on-site express support system is executed, a driver of a vehicle other than the emergency vehicle may feel uncomfortable because the change interval of the signal color is different from the normal one. For this reason, when the on-site express support system is being executed, it is preferable that the driver of the vehicle other than the emergency vehicle is informed. To cope with this, the terminal device according to the fifth embodiment, particularly the terminal device mounted in the emergency vehicle, uses information indicating that FAST control is being performed (hereinafter, “FAST control information”) as a packet signal. Include and send. The communication system 100 according to the fifth embodiment is the same type as that shown in FIG. 1, the base station device 10 according to the fifth embodiment is the same type as that shown in FIG. 2, and the terminal device 14 according to the fifth embodiment is shown in FIG. This is the same type as 4, and here, the difference will be mainly described.

  The generation unit 66 of the terminal device 14 shown in FIG. 4, particularly the terminal device 14 mounted on an emergency vehicle, detects that FAST control is being performed. In response to this, the generation unit 66 inserts the FAST controlling information into the packet signal. FIG. 12 shows information included in a packet signal according to the fifth embodiment of the present invention. As shown in the figure, “FAST control in progress” information is included in the packet signal.

  The modem unit 54 and the processing unit 56 of the terminal device 14 illustrated in FIG. 4, particularly the terminal device 14 mounted on the vehicle 12 other than the emergency vehicle, receive packet signals from the terminal device 14 mounted on the emergency vehicle. . The extraction unit 72 extracts information during FAST control from the packet signal. The extraction unit 72 outputs the FAST controlling information to the notification unit 70. The notification unit 70 notifies the driver that the FAST control is being performed based on the FAST control in-progress information. When the terminal device 14 receives the FAST control in-progress information, when the terminal device 14 is traveling in the same direction (true reverse direction) as the course of the emergency vehicle, the driver knows that the vehicle 12 is traveling on the route under FAST control. As well as a notification that there is a possibility that the emergency vehicle is traveling at a faster speed than usual. On the other hand, when the route of the vehicle 12 intersects the route of the emergency vehicle, the terminal device 14 is fixed in red by the FAST control at the front intersection signal and does not change to blue until the emergency vehicle passes. Notify the driver.

  According to the embodiment of the present invention, since the FAST control in-progress information is included in the packet signal, the situation can be notified to the driver of the vehicle other than the emergency vehicle.

(Example 6)
Next, a sixth embodiment of the present invention will be described. The sixth embodiment relates to communication between the terminal device mounted on the emergency vehicle and the terminal device mounted on the vehicle, as before. The terminal device mounted on the vehicle notifies the encounter with the emergency vehicle based on the position information. For example, when facing an emergency vehicle, it is notified that there is a possibility of a frontal collision with the emergency vehicle. However, such a notification is not necessary when a median strip is provided on the traveling road. In order to cope with this, the terminal device according to the sixth embodiment, particularly the terminal device mounted on the emergency vehicle, packetizes information indicating that there is a central separation band (hereinafter, “information with central separation band”). Include in the signal and transmit. The communication system 100 according to the sixth embodiment is the same type as that in FIG. 1, the base station apparatus 10 according to the sixth embodiment is the same type as that in FIG. 2, and the terminal apparatus 14 according to the sixth embodiment is This is the same type as 4, and here, the difference will be mainly described.

  The modem unit 54 and the processing unit 56 of the terminal device 14 illustrated in FIG. 4, particularly the terminal device 14 mounted on the emergency vehicle, receive the packet signal including the road information from the base station device 10. The road information indicates that, for example, a median strip is provided on the road. The extraction unit 72 extracts road information from the packet signal and outputs it to the generation unit 66. The generation unit 66 receives road information from the extraction unit 72. The generation unit 66 specifies that a median strip is provided on the traveling road based on the road information. When the central band is provided, the generation unit 66 inserts information with the central band into the packet signal. FIG. 13 shows information included in a packet signal according to Embodiment 6 of the present invention. As shown in the figure, “with median” information is included in the packet signal.

  The modem unit 54 and the processing unit 56 of the terminal device 14 illustrated in FIG. 4, particularly the terminal device 14 mounted on the vehicle 12 other than the emergency vehicle, receive packet signals from the terminal device 14 mounted on the emergency vehicle. . The extraction unit 72 extracts information with a median strip from the packet signal. The extraction unit 72 outputs the information with the median strip to the determination unit 84. The determination unit 84 does not perform avoidance support when it receives information indicating that there is a median and when it is traveling straight ahead against the emergency vehicle. This corresponds to not providing emergency vehicle approach information.

  FIG. 14 is a flowchart illustrating a determination procedure by the terminal device 14 according to the sixth embodiment of the present invention. The determination unit 84 detects an approach from the front (S60). If there is a median strip (Y in S62), the determination unit 84 does not cause the notification unit 70 to perform notification (S64). On the other hand, if there is no median strip (N in S62), the determination unit 84 causes the notification unit 70 to perform notification (S66).

  According to the embodiment of the present invention, when there is a median strip, the support is not executed, so that the unnecessary support can be suppressed.

(Example 7)
Next, a seventh embodiment of the present invention will be described. The seventh embodiment relates to a communication system that performs emergency vehicle passage assistance in the same manner as the first to third embodiments. The terminal device mounted on the emergency vehicle transmits that it is “emergency traveling” together with information such as its position, traveling direction, and speed by wireless communication. The terminal device that has received it, and the terminal device mounted on the vehicle, when it is determined that the emergency vehicle reaches the vicinity of the host vehicle within a certain time, or when both are present within a certain distance, Notify the driver accordingly. Here, if the emergency vehicle is temporarily reduced in speed when entering an intersection, etc., it will be determined that the arrival time will be longer on the receiving vehicle, and the driver will be supported despite the situation that the emergency vehicle is approaching. Is temporarily interrupted.

  In order to prevent this, the terminal device according to the present embodiment, the terminal device mounted on the vehicle is in a positional relationship with the emergency vehicle, for example, in which direction the emergency vehicle is approaching and in which direction Once the support is generated, the support is maintained even if the speed of the emergency vehicle drops extremely as long as the positional relationship is maintained. Thereby, support is continued without interruption during the approach of the emergency vehicle. The communication system 100 according to the seventh embodiment is the same type as in FIG. 1, the base station apparatus 10 according to the seventh embodiment is the same type as in FIG. 2, and the terminal apparatus 14 according to the seventh embodiment is the same as FIG. This is the same type as 4, and here, the difference will be mainly described.

  As described above, the estimation unit 78 of FIG. 4 estimates the time until the main vehicle 12 and the emergency vehicle meet, and outputs the estimated time to the determination unit 84. As described above, the derivation unit 80 derives the distance between the vehicle and the emergency vehicle and outputs the derived distance to the determination unit 84. The determination unit 84 receives time from the estimation unit 78 and receives a distance from the derivation unit 80. The determination unit 84 determines that an emergency vehicle is encountered when the time estimated by the estimation unit 78 is less than or equal to the first threshold value or when the distance derived by the derivation unit 80 is less than or equal to the second threshold value. In cases other than these, the determination unit 84 determines that the vehicle is not encountered with the emergency vehicle.

  Here, the determination part 84 acquires the positional relationship at the time of this vehicle 12 and an emergency vehicle encounter, when it determines with encountering. The positional relationship corresponds to a relative angle when the vehicle 12 and the emergency vehicle meet. Specifically, when the traveling direction of the vehicle 12 is 0 degree and a coordinate system in which the angle increases in the clockwise direction is defined, the angle at which the emergency vehicle enters is shown as a relative angle. It is. The determination unit 84 stores the positional relationship at that time, that is, the relative angle as an “initial angle”. Thereafter, the determination unit 84 continuously performs the determination based on the periodically acquired time and distance.

  When the first encounter is determined by the time estimated by the estimating unit 78 being equal to or less than the first threshold value, the time estimated by the estimating unit 78 is the first threshold when the traveling speed of the emergency vehicle decreases. It can be greater than the value. In this case, it is assumed that the distance derived by the deriving unit 80 is not less than the second threshold value. In that case, the state determined to be an encounter transitions to non-encounter. Thereafter, when the traveling speed of the emergency vehicle increases and the time estimated by the estimation unit 78 is equal to or less than the first threshold value, or the distance that the emergency vehicle travels and is derived at the deriving unit 80 is equal to or less than the second threshold value. , Transition from the state determined as non-encounter to encounter. That is, despite the situation that an emergency vehicle is approaching the host vehicle, the determination unit 84 determines that encounter → non-encounter → encounter, and the support for the driver is temporarily interrupted. In order to prevent this, after the encounter determination is made, the determination unit 84 determines the positional relationship (hereinafter referred to as “target angle”) when the time estimated by the estimation unit 78 becomes larger than the first threshold value. "). The deriving unit 80 defines a range of angles including the initial angle. The range of the angle is determined to be ± 15 degrees with the initial angle as the center, for example. When the target angle is included in the angle range, the deriving unit 80 determines that the positional relationship between the vehicle and the emergency vehicle is maintained, and continues the encounter state. On the other hand, when the target angle is not included in the angle range, the deriving unit 80 determines that the positional relationship is not maintained, and changes the encounter state to non-encounter.

  FIG. 15 is a flowchart illustrating a determination procedure by the terminal device 14 according to the seventh embodiment of the invention. The determination part 84 determines with this vehicle 12 and the emergency vehicle approaching (S80). Even if the approach state is not satisfied (N in S82), if the relationship is maintained (Y in S84), the determination unit 84 maintains the approach and returns to Step 82. When the approach state is satisfied (Y in S82), the determination unit 84 maintains the approach and returns to Step 82. On the other hand, if the relationship is not maintained (N in S84), the determination unit 84 determines non-contact (S86).

  According to the embodiment of the present invention, once the encounter determination is made, it is determined that the vehicle is approaching if the positional relationship (initial angle) between the vehicle and the emergency vehicle is maintained. Even if the speed is temporarily reduced due to approaching an intersection or the like, the driver can be continuously notified of the approach without assistance being interrupted. In addition, since the driver is continuously notified of the approach, it is possible to reliably notify the approach of the emergency vehicle.

(Example 8)
Next, an eighth embodiment of the present invention will be described. The eighth embodiment relates to a communication system that determines approach of a vehicle by transmitting position information between a plurality of terminal devices, similarly to the first to third embodiments. In particular, the approach is determined based on the time until encounter and the distance between the vehicles. On the other hand, in the first to third embodiments, it is assumed that the vehicle and the emergency vehicle approach each other, but in the eighth embodiment, a case where vehicles that are not emergency vehicles approach each other is assumed. Here, two cases will be described in particular. The first is a case where a vehicle traveling in a traveling lane changes to a passing lane, and the second is a case where a vehicle traveling in a merged lane joins the traveling lane. The communication system 100 according to the eighth embodiment is the same type as in FIG. 1, the base station apparatus 10 according to the eighth embodiment is the same type as in FIG. 2, and the terminal apparatus 14 according to the eighth embodiment is This is the same type as 4, and here, the difference will be mainly described.

  FIGS. 16A and 16B show the configuration of the communication system 100 according to the eighth embodiment of the present invention. In FIG. 16A, the first vehicle 12a is traveling in the traveling lane, and the second vehicle 12b is traveling in the overtaking lane behind the first vehicle 12a. Here, the notification at the terminal device 14 (not shown) mounted on the first vehicle 12a is an object of explanation. The configuration of the terminal device 14 mounted on the first vehicle 12a is shown in FIG. 4 as described above, but the state determination unit 76 includes an acquisition unit (not shown).

  The acquisition unit acquires a trigger for changing the lane in which the vehicle 12 on which the terminal device 14 is mounted is traveling. Here, three types of methods are illustrated as acquisition of the lane change trigger. The first is a case where the driver uses a direction indicator to instruct a change in the direction of travel to the right. The acquisition unit is connected to a direction indicator or a control device that controls the direction indicator, and receives an instruction to change the traveling direction. When the acquisition unit receives the direction change instruction, it recognizes that the lane change trigger has been acquired. The direction of travel direction change may be a change to the left instead of a change to the right. This corresponds to a case where the vehicle 12 traveling in the overtaking lane changes to a traveling lane.

  The second case is a case where the acquisition unit is connected to an in-vehicle camera (not shown) and the determination is based on an image captured by the in-vehicle camera. More specifically, the in-vehicle camera is mounted on the vehicle 12 so as to capture an image of 90 degrees or around 270 degrees from the traveling direction of the vehicle 12. Therefore, the in-vehicle camera images a white line (continuous line, broken line) or a yellow line (hereinafter collectively referred to as “white line”) provided along the lane in which the vehicle 12 is traveling. The acquisition unit measures the distance from the captured image to the white line on the right side in the traveling direction by the image recognition process. Such distance measurement is continuously performed. The acquisition unit detects that the vehicle 12 is approaching the white line through continuous measurement. For example, if the distance is shortened over a certain period and the final distance is shorter than a threshold value, the acquisition unit recognizes that a lane change trigger has been acquired.

  The third is a case where a combination of a rotation angle from the steering and an image captured by the in-vehicle camera is used. In this case, the acquisition unit receives an image captured by the in-vehicle camera as before. Here, the in-vehicle camera is mounted on the vehicle 12 so that the traveling direction of the vehicle 12 can be imaged. The acquisition unit detects whether the lane in which the vehicle 12 is traveling is a straight line and how many times it is curved from the captured image by image recognition processing. The acquisition unit is connected to the steering or a control device that controls the steering, and receives information on the rotation angle of the steering.

  The acquisition unit derives an angle obtained by subtracting the angle of the curve from the rotation angle of the steering (hereinafter referred to as “evaluation angle”) when the rotation angle of the steering and the angle of the curve are in the same direction. On the other hand, the acquisition unit derives an angle obtained by adding the angle of the curve to the rotation angle of the steering (hereinafter referred to as “evaluation angle”) when the rotation angle of the steering and the angle of the curve are in opposite directions. In addition, when the lane is a straight line, the acquisition unit sets the rotation angle of the steering as the “evaluation angle”. These evaluation angles correspond to the angles at which the vehicle 12 is inclined with respect to the lane. The acquisition unit recognizes that the lane change trigger has been acquired when the absolute value of the evaluation angle is larger than the threshold value. The determination unit 84 starts the above-described notification when the acquisition unit acquires a trigger.

  In FIG. 16A, it is assumed that the first vehicle 12a travels at 60 km / h and the second vehicle 12b travels at 100 km / h. Under such circumstances, when the acquisition unit of the first vehicle 12a acquires a trigger, the difference between both speeds is large and the distance is long, so the determination unit 84 of the first vehicle 12a takes time to approach The judgment process is executed with. In FIG. 16A, it is assumed that the first vehicle 12a travels at 60 km / h and the second vehicle 12b also travels at 60 km / h. Under such circumstances, when the acquisition unit of the first vehicle 12a acquires a trigger, the determination unit 84 of the first vehicle 12a executes the determination process at the distance between the two because the speed difference between the two is small.

  In FIG. 16 (b), the first vehicle 12a travels in the confluence lane at 60km / h, and the second vehicle 12b travels in the travel lane at 100km / hr behind the first vehicle 12a. Under such circumstances, when the acquisition unit of the first vehicle 12a acquires the trigger, the difference between the speeds of both is large, so the determination unit 84 of the first vehicle 12a executes the determination process in the time until approaching. To do. Further, in FIG. 16B, it is assumed that the first vehicle 12a travels at 60 km / h and the second vehicle 12b also travels at 60 km / h. Under such circumstances, when the acquisition unit of the first vehicle 12a acquires a trigger, the determination unit 84 of the first vehicle 12a executes the determination process at the distance between the two because the speed difference between the two is small.

  FIG. 17 is a flowchart illustrating a determination procedure by the terminal device 14 according to the eighth embodiment of the present invention. When the acquisition unit receives the trigger (Y in S100), the determination unit 84 performs notification (S102). If the acquisition unit does not accept the trigger (N in S100), step 102 is skipped.

  According to the embodiment of the present invention, the notification is started when the trigger for changing the lane in which the vehicle is traveling is acquired, so that the erroneous determination is reduced and even when a vehicle other than the emergency vehicle is notified. , Can accurately notify the approach of the vehicle.

  In the above, this invention was demonstrated based on the Example. This embodiment is an exemplification, and it will be understood by those skilled in the art that various modifications can be made to each of those constituent elements or combinations of processing processes, and such modifications are also within the scope of the present invention. .

  In the second and third embodiments of the present invention, the determination unit 84 adjusts the first threshold value and the second threshold value. However, the present invention is not limited to this. For example, the determination unit 84 may adjust only one of the first threshold value and the second threshold value. According to this modification, processing can be simplified.

  In the third embodiment, the determination unit 84 specifies the lamp color of the signal based on the lamp color information included in the packet signal from the base station device 10. However, the present invention is not limited to this. For example, the vehicle 12 includes an imaging device that captures a traffic light ahead, and the determination unit 84 analyzes the image captured by the imaging device, thereby causing the traffic signal included in the image. You may specify the lamp color. According to the present modification, the first threshold value and the second threshold value can be adjusted in accordance with the lamp color in a situation where the packet signal from the base station apparatus 10 is not received.

  Any combination of Examples 1 to 8 is also effective. According to this modification, it is possible to obtain an effect obtained by arbitrarily combining the first to eighth embodiments.

  The outline of one embodiment of the present invention is as follows. A wireless device according to an aspect of the present invention is a wireless device that can be mounted on a vehicle, is a packet signal from another wireless device, and includes position information of another vehicle on which the other wireless device is mounted. Included in the reception unit that receives at least the packet signal included, the acquisition unit that acquires the position information of the vehicle on which the wireless device is mounted, the position information acquired in the acquisition unit, and the packet signal received in the reception unit Based on the position information, an estimation unit that estimates a time until the vehicle and another vehicle meet, the position information acquired by the acquisition unit, and the position information included in the packet signal received by the reception unit; And the derivation unit for deriving the distance between the vehicle and the other vehicle, and the time estimated by the estimation unit is less than or equal to the first threshold value, or the distance derived by the derivation unit is second. Below threshold In some cases, it includes a determination unit that notifies the encounter with another vehicle, a.

  According to this aspect, since an encounter is notified based on the time until the other vehicle is encountered and the distance from the other vehicle, the approach of the other vehicle can be notified accurately.

  You may further provide the memory | storage part which memorize | stores the positional information on an intersection. The deriving unit, when there is an intersection between the vehicle and another vehicle, instead of the distance between the vehicle and the other vehicle, the position information acquired in the acquisition unit, and the position information stored in the storage unit Based on the above, the distance between the vehicle and the intersection may be derived. In this case, if there is an intersection with another vehicle, the distance to the other vehicle is shortened, so the possibility of notification can be improved.

  The packet signal received by the receiving unit also includes information regarding the traveling direction of the other vehicle, the acquiring unit also acquires information regarding the traveling direction of the vehicle, and the determining unit relates to the traveling direction acquired by the acquiring unit. Based on the information and information on the traveling direction included in the packet signal received by the receiving unit, a relative direction when encountering another vehicle is estimated, and the first is determined according to the estimated relative direction. The threshold value and the second threshold value may be adjusted. In this case, since the first threshold value and the second threshold value are adjusted according to the relative direction, notification according to the situation can be executed.

  You may further provide the reception part which receives the information regarding the light color of the traffic signal installed in the advancing direction of a vehicle. The determination unit may adjust the first threshold value and the second threshold value according to information on the lamp color received in the reception unit. In this case, since the first threshold value and the second threshold value are adjusted according to the lamp color, notification according to the lamp color can be executed.

  You may further provide the acquisition part which acquires the trigger which changes the lane in which the vehicle carrying this radio | wireless apparatus is drive | working. The determination unit may start notification when the acquisition unit acquires a trigger. In this case, since the notification is started when the trigger is acquired, erroneous determination is reduced, and even when the approach of a vehicle other than the emergency vehicle is notified, the approach of the vehicle can be notified accurately.

  10 base station devices, 12 vehicles, 14 terminal devices, 16 emergency vehicles, 18 virtual emergency vehicles, 20 antennas, 22 RF units, 24 modem units, 26 processing units, 28 control units, 30 network communication units, 32 frame defining units, 34 selection unit, 36 generation unit, 50 antenna, 52 RF unit, 54 modulation / demodulation unit, 56 processing unit, 58 control unit, 60 timing identification unit, 62 transfer determination unit, 64 position information acquisition unit, 66 generation unit, 70 notification unit 72 extraction unit, 74 carrier sense unit, 76 state determination unit, 78 estimation unit, 80 deriving unit, 82 storage unit, 84 determination unit, 100 communication system, 202 network, 212 area, 214 area outside.

Claims (3)

A wireless device that can be mounted on a vehicle,
A receiver for receiving a packet signal from another wireless device and including at least position information of another vehicle on which the other wireless device is mounted;
An acquisition unit for acquiring position information of a vehicle on which the wireless device is mounted;
Based on the position information acquired in the acquisition unit and the position information included in the packet signal received in the reception unit, an estimation unit that estimates the time until the vehicle and another vehicle meet,
A derivation unit for deriving a distance between the vehicle and another vehicle based on the positional information acquired by the acquisition unit and the positional information included in the packet signal received by the reception unit;
A determination unit that notifies an encounter with another vehicle using both the time estimated in the estimation unit and the distance derived in the deriving unit;
A wireless device comprising:   The determination unit determines an encounter with another vehicle when the time estimated by the estimation unit is less than or equal to a first threshold value or when the distance derived by the derivation unit is less than or equal to a second threshold value. When the time estimated by the estimating unit is larger than the first threshold value and the distance derived by the deriving unit is larger than the second threshold value, it is determined that the vehicle does not encounter another vehicle. The wireless device according to claim 1. A storage unit for storing intersection position information;
When there is an intersection between the vehicle and another vehicle, the deriving unit stores the position information acquired in the acquisition unit and the storage unit instead of the distance between the vehicle and the other vehicle. The wireless device according to claim 1, wherein a distance between the vehicle and the intersection is derived based on the position information.

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