JP2017174331A - Terminal device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique to support driving, taking the travel direction of a vehicle into consideration.SOLUTION: A first acquisition unit 40 acquires first positional information of a host vehicle. A reception unit 30 receives second positional information of another vehicle. A second acquisition unit 42 acquires gear information on a gear selected at the host vehicle. A derivation unit 46 derives time at which the other vehicle arrives at an encounter spot on the basis of the first positional information and the second positional information. A notification unit 48 gives a warning notice if the derived time is a threshold value or less. The notification unit 48 changes the threshold value depending on the gear information.SELECTED DRAWING: Figure 3

Description

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

  When there is a possibility of contact with an obstacle as driving assistance for preventing contact with an obstacle of the vehicle, the contact avoidance assistance device issues an alarm (see, for example, Patent Document 1).

JP 2012-221451 A

  When the vehicle moves backward as compared with the case where the vehicle moves forward, it is difficult for the driver to see the traveling direction, so it is difficult to confirm the traveling direction. Further, when the vehicle that has been moving backward moves forward, a direction change occurs. For this reason, it is preferable that the warning output when the vehicle moves backward is performed at a timing different from the warning output when the vehicle moves forward.

  This invention is made | formed in view of such a condition, The objective is to provide the technique which performs the driving assistance which considered the advancing direction of the vehicle.

  In order to solve the above problems, a terminal device according to an aspect of the present invention is a terminal device that can be mounted on a vehicle, and acquires first position information of the vehicle on which the terminal device is mounted. A receiving unit that receives second position information of another vehicle transmitted from another terminal device mounted on the other vehicle, and a second that acquires gear information related to a gear selected in the vehicle. Based on the acquisition unit, the first position information acquired by the acquisition unit, and the second position information received by the reception unit, another vehicle is located at an encounter point where the present vehicle and another vehicle can encounter. A derivation unit that derives the arrival time and a notification unit that notifies a warning when the time derived in the derivation unit is equal to or less than a threshold value are provided. A notification part changes a threshold value according to the gear information acquired in the 2nd acquisition part.

  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.

  ADVANTAGE OF THE INVENTION According to this invention, the driving assistance which considered the advancing direction of the vehicle can be performed.

It is a figure which shows the structure of the communication system which concerns on Example 1 of this invention. 2A to 2D are diagrams showing a frame format defined in the communication system of FIG. It is a figure which shows the structure of the terminal device of FIG. 4A to 4C are diagrams showing an outline of processing by the communication system of FIG. It is a flowchart which shows the notification procedure by the terminal device of FIG. FIGS. 6A to 6D are diagrams illustrating an outline of another process performed by the communication system according to the second embodiment of the present invention.

Example 1
Before describing the present invention in detail, an outline 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 position, speed, and traveling direction 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 broadcasts a packet signal using the CSMA method regardless of the frame configuration.

  Under such circumstances, the terminal device according to the present embodiment provides driving support when the support generation condition is satisfied based on the information included in the packet signal received from another terminal device or the base station device. decide. Here, an example of information included in the packet signal is position information of a vehicle on which another terminal device is mounted. The driving support is to support the driver for driving, and an example thereof is support for preventing collision at encounter. The encounter collision prevention support notifies the driver of the presence of an approaching vehicle when another vehicle is approaching so as to intersect when the vehicle goes straight. Although a plurality of types of driving support are defined, here, for the sake of clarity, the encounter collision prevention support is the target of the description.

  In the encounter collision prevention support, the time required for the other vehicle to reach a point where the vehicle going straight and another vehicle approaching from the intersecting direction can encounter (hereinafter referred to as “the encounter point”) is calculated. The When the time is equal to or less than the threshold value, the vehicle is determined to perform the encounter collision prevention support. Here, the threshold value is set on the assumption that the vehicle is moving forward. However, as described above, when the vehicle is moving backward, it is difficult for the driver to confirm the traveling direction, and a direction change may occur. Therefore, when the vehicle is moving backward as compared with the case where the vehicle is moving forward, it is preferable that the encounter collision prevention support is executed earlier.

  In order to cope with this, in the present embodiment, when the vehicle moves backward, driving assistance is executed at a timing different from that when moving forward. For example, when going backward from a parking lot to a public road, driving assistance is executed early on the assumption that it goes from the public road until it changes direction and moves forward. Specifically, the threshold value is changed depending on whether the vehicle is moving forward or backward. In other words, the threshold value for the backward travel is set to a larger value than the threshold value for the forward travel.

  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 200. Here, only the first vehicle 12 a is shown, but each vehicle 12 is equipped with a terminal device 14. An area 202 is formed around the base station apparatus 10, and an outside area 204 is formed outside the area 202.

  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 central portion. 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”. An intersection of 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. An example of the vehicle 12 is an automobile.

  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. For example, ten “100 msec” frames are generated by dividing the “1 sec” period indicated in the signal received from the GPS satellite into ten. 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 broadcasts and transmits a packet signal in the set road and vehicle transmission period. In the road and vehicle transmission period, a plurality of packet signals may be broadcast. 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 200.

  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 202. When the terminal device 14 exists in the area 202, 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 broadcasts and transmits a packet signal in a vehicle and vehicle transmission period that is 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 204, the terminal apparatus 14 broadcasts a packet signal by executing CSMA / CA regardless of the frame configuration. The terminal device 14 recognizes the approach of the other vehicle 12 on which the other terminal device 14 is mounted based on the packet signal from the other terminal device 14.

  2A to 2D show frame formats defined in the communication system 100. FIG. FIG. 2A 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 broadcast transmission 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.

  FIG. 2B shows a configuration of a frame generated by the first base station apparatus 10a (not shown). The first base station device 10 a is one of the base station devices 10. The first base station apparatus 10a sets a road and vehicle transmission period at the beginning of the first subframe. The road and vehicle transmission period is an organization in which the base station apparatus 10 can broadcast and transmit a packet signal. Moreover, the 1st base station apparatus 10a sets a vehicle transmission period following a road and vehicle transmission period in a 1st sub-frame. The vehicle transmission period is a period during which the terminal device 14 can broadcast the packet signal. That is, the first base station apparatus 10a can broadcast-transmit a packet signal in the road and vehicle transmission period that is the first period of the first subframe, and the terminal in the vehicle and vehicle transmission period other than the road and vehicle transmission period in the frame. It is defined that the device 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. 2C 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. 2D 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.

  FIG. 3 shows the configuration of the terminal device 14. The terminal device 14 includes a communication unit 20 and a processing unit 22. The communication unit 20 includes a receiving unit 30, a timing specifying unit 32, and a transmitting unit 34. The processing unit 22 includes a first acquisition unit 40, a second acquisition unit 42, a generation unit 44, a derivation unit 46, and a notification unit 48. As described above, the terminal device 14 can be mounted on the vehicle 12.

  The receiving unit 30 receives a packet signal from another terminal device 14 or the base station device 10 (not shown) via an antenna. The receiving unit 30 performs frequency conversion on the received radio frequency packet signal to generate a baseband packet signal. The receiving unit 30 also performs demodulation on the baseband packet signal. Here, since the communication system 100 corresponds to an OFDM (Orthogonal Frequency Division Multiplexing) modulation scheme, the receiving unit 30 also executes an FFT (Fast Fourier Transform). Further, the receiving unit 30 outputs the demodulated result to the processing unit 22 and the timing specifying unit 32.

  When the demodulation result from the receiving unit 30 is a packet signal from the base station apparatus 10 (not shown), the timing specifying unit 32 specifies the timing of the subframe in which the road and vehicle transmission period is arranged. At that time, the timing specifying unit 32 estimates that the area exists in the area 202 of FIG. The timing specifying unit 32 generates a frame synchronized with the frame formed in the base station apparatus 10 based on the information included in the packet signal from the base station apparatus 10. On the other hand, when the packet signal from the base station device 10 is not input, the timing specifying unit 32 estimates that the timing specifying unit 32 exists outside the area 204 in FIG.

  When it is estimated that the timing specifying unit 32 exists in the area 202, the timing specifying unit 32 selects the vehicle transmission period. Moreover, the timing specific | specification part 32 determines a transmission timing by starting CSMA / CA within a vehicle transmission period. The timing specifying unit 32 determines the transmission timing by executing CSMA / CA without considering the frame configuration. The timing specifying unit 32 notifies the transmission unit 34 of the determined transmission timing.

  The transmission unit 34 performs modulation on the data from the processing unit 22. As described above, since the communication system 100 supports the OFDM modulation scheme, the transmission unit 34 also executes IFFT (Inverse Fast Fourier Transform). Further, the transmission unit 34 performs frequency conversion on the baseband packet signal that is the result, and generates a radio frequency packet signal. Further, the transmission unit 34 broadcasts a radio frequency packet signal from the antenna at the transmission timing notified from the timing specifying unit 32.

  The first acquisition unit 40 includes a GPS receiver, a gyroscope, a vehicle speed sensor, and the like (not shown). The first acquisition unit 40 uses the data supplied from the first acquisition unit 40 to determine the presence position, traveling direction, moving speed, and the like (hereinafter collectively referred to as “first position information”) of the vehicle 12 on which the terminal device 14 is mounted. get. The existence position is indicated by latitude and longitude. The traveling direction is indicated by an azimuth angle, with north as a reference azimuth (0 degree) and clockwise as a positive angle. Since a known technique may be used for these acquisitions, description thereof is omitted here. The first acquisition unit 40 outputs the first position information to the generation unit 44 and the derivation unit 46.

  As described above, the demodulated result is output from the receiving unit 30. The demodulated result includes the presence position, traveling direction, moving speed, etc. of the other vehicle 12 transmitted from the other terminal device 14 mounted on the other vehicle 12 (hereinafter collectively referred to as “second position information”). ) Is included. The second position information is input to the derivation unit 46. The 2nd acquisition part 42 acquires gear information about the gear currently selected in this vehicle 12 from ECU (Electronic Control Unit) via CAN (Controller Area Network). The gear information indicates forward or reverse. Similar to the first acquisition unit 40, the second acquisition unit 42 outputs gear information to the generation unit 44 and the derivation unit 46.

  The derivation unit 46 inputs the first position information from the first acquisition unit 40, the gear information from the second acquisition unit 42, and the second position information from the reception unit 30. The deriving unit 46 estimates the route that the vehicle 12 will travel from the first position information, and estimates the route that the other vehicle 12 will travel from the second position information. In addition, the deriving unit 46 associates these routes with map data to identify points where the present vehicle 12 and other vehicles 12 can encounter (hereinafter referred to as “encounter points”).

  The deriving unit 46 derives the time for the vehicle 12 to reach the encounter point by dividing the distance between the presence position in the first position information and the encounter point by the moving speed in the first position information. Further, the deriving unit 46 derives the time for the other vehicle 12 to reach the encounter point by dividing the distance between the presence position and the encounter point in the second position information by the moving speed in the second position information. To do. Furthermore, the deriving unit 46 derives a difference between the time when the vehicle 12 reaches the encounter point and the time when the other vehicle 12 reaches the encounter point, and the derived time difference is within a predetermined time difference, for example, within 3 seconds. If there is, it is determined that the present vehicle 12 and another vehicle 12 encounter each other. When it is determined that the vehicle encounters, the derivation unit 46 outputs the gear information of the vehicle 12 to the notification unit 48 for the time when the other vehicle 12 reaches the encounter point.

  The notification unit 48 inputs the gear information of the vehicle 12 from the derivation unit 46 for the time when the other vehicle 12 reaches the encounter point. The notification unit 48 sets a threshold value according to the gear information. For example, when the gear information indicates a forward gear, the derivation unit 46 sets the threshold value to “A”. On the other hand, when the gear information indicates the reverse gear, the deriving unit 46 sets the threshold value to “A + B”. That is, the notification unit 48 increases the threshold value in the case where the gear information indicates the reverse gear than in the case where the gear information indicates the forward gear.

  When the time for the other vehicle 12 to reach the encounter point is equal to or less than the threshold value, the notification unit 48 determines the presence of driving assistance. On the other hand, when the time for the other vehicle 12 to reach the encounter point is larger than the threshold value, the notification unit 48 determines that there is no driving support. When it is determined that there is driving support, the notification unit 48 notifies a warning. The warning is notified by at least one of a screen and sound. Since the threshold value is larger in the case of the backward movement than in the case of the forward movement, the warning is notified at an earlier timing in the case of the backward movement than in the forward movement.

  The generation unit 44 inputs the first position information from the first acquisition unit 40 and the gear information from the second acquisition unit 42. The generation unit 44 generates a packet signal including these. The generation unit 44 outputs the packet signal to the transmission unit 34.

  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.

  4A to 4C show an outline of processing by the communication system 100. FIG. FIG. 4A shows the operation of the first vehicle 12a, which is a precondition for processing by the communication system 100. FIG. The first vehicle 12a is in a state where the first vehicle 12a is parked by moving forward with respect to the parking lot facing the public road (road), and is about to exit the public road on the parking lot side. In the initial state, the first vehicle 12a is located in the parking lot (point P1). From this state, the first vehicle 12a moves backward to the point P3 through the point P2 by changing the direction after entering the public road while moving backward. Furthermore, the 1st vehicle 12a moves to the point P2 by moving forward. Here, it is assumed that time “B” is required until the first vehicle 12a reaches the point P3 through the point P2 and moves again to the point P2. The point P2 is a position corresponding to a point P4 described later.

  FIG. 4B shows a case where the first vehicle 12a enters the public road while moving forward from the parking lot. On the other hand, the second vehicle 12b is traveling on the public road. The encounter point between the first vehicle 12a and the second vehicle 12b is indicated as a point P4. If the time until the second vehicle 12b reaches the point P4 is equal to or less than the threshold “A”, the driving assistance is executed in the first vehicle 12a.

  FIG. 4C shows a case where the first vehicle 12a enters the public road while moving backward from the parking lot, as in FIG. 4A. In this case, the time from turning on the public road to changing the direction and moving forward is set to “B”, as described above. Driving assistance should be generated at an early timing in one vehicle 12a. Specifically, if the time until the second vehicle 12b reaches the point P4 is equal to or less than the threshold value “A + B”, the driving assistance is executed in the first vehicle 12a. That is, the threshold value is increased as compared with the case of FIG.

  The operation of the communication system 100 configured as above will be described. FIG. 5 is a flowchart showing a notification procedure by the terminal device 14. When the vehicle 12 is moving forward (Y of S10), the notification unit 48 sets the threshold value to “A” (S12), and when the vehicle 12 is not moving forward (N of S10), the notification unit 48 sets the threshold value to "A + B" (S14). If it is determined in the derivation unit 46 (Y in S16) that the time is equal to or less than the threshold value (Y in S18), the notification unit 48 notifies a warning (S20). If it is not determined in the derivation unit 46 (N in S16), or if the time is not less than or equal to the threshold value (N in S18), the process is terminated.

  According to the embodiment of the present invention, since the threshold value is changed according to the vehicle gear information, the warning notification timing can be changed according to the traveling direction of the vehicle. In addition, since the warning notification timing is changed according to the traveling direction of the vehicle, it is possible to perform driving support in consideration of the traveling direction of the vehicle. In addition, since the threshold value is increased in the case of backward travel than in the case of forward travel, the warning notification timing can be made earlier in the backward travel direction than in the forward travel. In addition, since the warning notification timing is earlier in the case of backward travel than in the case of forward travel, the safety of driving support can be increased.

(Example 2)
Next, Example 2 will be described. In the second embodiment, as in the first embodiment, a communication system that performs inter-vehicle communication between terminal devices mounted on a vehicle and also performs road-to-vehicle communication from a base station device installed at an intersection or the like to a terminal device About. In addition, support for encounter collision prevention will be covered. On the other hand, in the first embodiment, the warning is in one stage, but in the second embodiment, it is assumed that the warning has two stages. The communication system 100 and the terminal device 14 according to the second embodiment are the same type as those in FIGS. Here, it demonstrates centering on the difference with Example 1. FIG.

  The notification unit 48 defines a first threshold value and a second threshold value as threshold values. Here, the second threshold value is larger than the first threshold value. The notification unit 48 sets the first threshold value and the second threshold value according to the vehicle gear information. For example, when the gear information indicates a forward gear, the derivation unit 46 sets the first threshold value to “A” and the second threshold value to “A + B”. On the other hand, when the gear information indicates the reverse gear, the deriving unit 46 sets the first threshold value to “A + B” and sets the second threshold value to “A + B + C”. “A” and “B” may be different from those in the first embodiment. As described above, the notification unit 48 uses the first threshold value and the second threshold value in the case where the gear information indicates the reverse gear than in the case where the gear information indicates the forward gear. Increase

  When the time for the other vehicle 12 to reach the encounter point is equal to or less than the first threshold value, the notification unit 48 notifies the driver of “warning” as a warning. When the time for the other vehicle 12 to reach the encounter point is greater than the first threshold value and less than or equal to the second threshold value, the notification unit 48 “provides information” to the driver as a warning. To be notified. Furthermore, when the time for the other vehicle 12 to reach the encounter point is longer than the second threshold value, the notification unit 48 determines that there is no driving support.

  Here, “notice” and “information provision” are common in terms of notifying the driver, but the level of urgency of the notification is different. “Warning” has a higher level of urgency than “information provision”. Therefore, for example, when “information provision” is notification by one of the screen and sound, “attention” is notification by both screen and sound. Further, the notification content in “calling attention” may be more urgent than the notification content in “providing information”.

  FIGS. 6A to 6D show an outline of another process performed by the communication system 100 according to the second embodiment of the present invention. FIG. 6A shows a case where the first vehicle 12a enters the public road while moving forward from the parking lot, as in FIG. 4B. If the time until the second vehicle 12b reaches the point P4 is equal to or less than the threshold value “A + B”, driving assistance by providing information is executed in the first vehicle 12a. FIG. 6B shows a state following FIG. If the time until the second vehicle 12b reaches the point P4 is equal to or less than the threshold “A”, driving assistance by alerting is executed in the first vehicle 12a.

  FIG. 6C shows a case where the first vehicle 12a enters the public road while moving backward from the parking lot, similarly to FIG. 4C. If the time until the second vehicle 12b reaches the point P4 is equal to or less than the threshold value “A + B”, driving assistance by alerting is executed in the first vehicle 12a. That is, although information was provided in FIG. 6A, attention is given in FIG. 6C, and therefore driving assistance at a higher level of danger is executed in the case of reverse travel than in the case of forward travel. FIG. 6D shows a state following FIG. Even if the time until the second vehicle 12b reaches the point P4 is equal to or less than the threshold value “A”, the driving assistance by alerting is continuously executed in the first vehicle 12a.

  According to the embodiment of the present invention, the first threshold value and the second threshold value are increased in the case where the vehicle is traveling backward than in the case where the vehicle is traveling forward. But you can be alerted in case you go backwards. In addition, since alerting is notified instead of providing information, the safety of driving support can be increased.

  The outline of one embodiment of the present invention is as follows. A terminal device according to an aspect of the present invention is a terminal device that can be mounted on a vehicle, and is mounted on another vehicle and a first acquisition unit that acquires first position information of the vehicle on which the terminal device is mounted. Received by the receiving unit that receives the second position information of the other vehicle transmitted from the other terminal device, the second acquiring unit that acquires the gear information related to the gear selected in the vehicle, and acquired by the acquiring unit A derivation unit for deriving a time for the other vehicle to reach an encounter point where the present vehicle and the other vehicle can encounter based on the first position information and the second position information received by the receiving unit. And a notifying unit for notifying a warning when the time derived by the deriving unit is equal to or less than the threshold value. A notification part changes a threshold value according to the gear information acquired in the 2nd acquisition part.

  According to this aspect, since the threshold value is changed according to the gear information of the vehicle, it is possible to execute driving support in consideration of the traveling direction of the vehicle.

  The notification unit sets the threshold value in the case where the gear information acquired in the second acquisition unit indicates a reverse gear than in the case where the gear information acquired in the second acquisition unit indicates a forward gear. You may enlarge it. In this case, since the threshold value is set larger in the case of the backward movement than in the case of the forward movement, the warning notification timing can be made earlier in the case of the backward movement than in the case of the forward movement.

  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 first and second embodiments, the example in which the vehicle 12 goes out to the public road on the same side as the parking lot where the vehicle is parked is not limited to this. You may apply to

  10 base station devices, 12 vehicles, 14 terminal devices, 20 communication units, 22 processing units, 30 receiving units, 32 timing specifying units, 34 transmitting units, 40 first acquiring units, 42 second acquiring units, 44 generating units, 46 Deriving unit, 48 notifying unit, 100 communication system.

Claims (2)

A terminal device that can be mounted on a vehicle,
A first acquisition unit that acquires first position information of the vehicle on which the terminal device is mounted;
A receiving unit that receives the second position information of the other vehicle transmitted from another terminal device mounted on the other vehicle;
A second acquisition unit that acquires gear information related to a gear selected in the vehicle;
Based on the first position information acquired by the acquisition unit and the second position information received by the reception unit, the other vehicle is located at an encounter point where the vehicle and the other vehicle can encounter. A derivation unit for deriving the time at which
When the time derived in the deriving unit is equal to or less than a threshold value, a notification unit that notifies a warning,
The said notification part changes a threshold value according to the gear information acquired in the said 2nd acquisition part, The terminal device characterized by the above-mentioned.   In the case where the gear information acquired in the second acquisition unit indicates a reverse gear than in the case where the gear information acquired in the second acquisition unit indicates a forward gear. The terminal device according to claim 1, wherein the threshold value is increased.

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