ELECTRONIC CONTROL DEVICE

Provided is an electronic control device that estimates a presence of a vehicle incapable of performing vehicle-to-vehicle communication ahead of a communication partner vehicle is estimated. An electronic control device 30 detects, on map data, an intersection 60 located ahead in a traveling direction of a host vehicle 10 based on location data and the map data of the host vehicle 10, calculates a stop position (first position) 71 where a communication partner vehicle 11 is supposed to pass through or stop when the communication partner vehicle 11 stops at the intersection 60, based on vehicle information of the communication partner vehicle 11 that is traveling toward the intersection 60, and determines whether or not there is another vehicle 13 ahead in the traveling direction of the communication partner vehicle 11, based on the stop position (first position) 71 and an intersection area 20 (second position 72) set before the intersection 60.

TECHNICAL FIELD

The present invention relates to an electronic control device.

BACKGROUND ART

Conventionally, use of a vehicle-to-vehicle communication system (V2V), a vehicle-to-vehicle and road-to-vehicle communication system (V2X), and the like are expected as a measure for preventing a vehicle contact accident at a blind spot such as an intersection.

The vehicle-to-vehicle communication system can prevent mutual contact accidents by exchanging vehicle information including mutual location data and velocity data between vehicles equipped with vehicle-to-vehicle communication devices. However, a sufficient purpose cannot be achieved in a case where there are vehicles incapable of vehicle-to-vehicle communication, such as a case where a vehicle-to-vehicle communication device is not mounted or a case where its communication function is not working.

JP 2007-137139 A describes that a traveling locus of a communication partner vehicle is drawn based on vehicle information of the communication partner vehicle obtained by a vehicle-to-vehicle communication system to estimate the presence of an obstacle on a road and secure safety for traveling of its own vehicle.

CITATION LIST

Patent Literature

SUMMARY OF INVENTION

Technical Problem

In the invention described in JP 2007-137139 A, an obstacle is detected based on a traveling locus of another vehicle (vehicle-to-vehicle communication partner vehicle) on which a vehicle-to-vehicle communication device is mounted, and a forward obstacle (for example, a vehicle that is not equipped with a vehicle-to-vehicle communication device, a person, a two-wheeled vehicle, a stationary object, or the like) cannot be found unless the vehicle-to-vehicle communication partner vehicle performs a non-linear avoidance operation (for example, overtaking operation) of avoiding the obstacle (forward obstacle) located ahead. For example, such a traveling locus is not drawn on a road of one lane that cannot be overtaken, and it is difficult to detect a forward obstacle. In a case where a host vehicle travels toward an intersection on a road and a vehicle-to-vehicle communication partner vehicle travels, toward the intersection, on another road intersecting at the intersection, the front obstacle cannot be detected only by the vehicle-to-vehicle communication, and there is a high possibility of collision with the host vehicle unless the front obstacle stops at the intersection.

The present invention has been made to solve such a problem, and an object of the present invention is to provide a technique for estimating the presence of a vehicle incapable of vehicle-to-vehicle communication traveling ahead of a vehicle-to-vehicle communication partner vehicle.

Solution to Problem

The present application includes a plurality of means for solving the above problems, and as an example thereof, there is provided an electronic control device that is mounted in a first vehicle having a vehicle-to-vehicle communication device and controls the first vehicle based on vehicle information of another vehicle, the vehicle information being received by the vehicle-to-vehicle communication device, in which the electronic control device detects, on map data, an intersection located ahead in a traveling direction of the first vehicle based on location data and the map data of the first vehicle, calculates a first position where a second vehicle is supposed to pass through or stop when the second vehicle is to stop before the intersection, based on second vehicle information that is vehicle information of the second vehicle traveling toward the intersection and that is vehicle information of the second vehicle received by the vehicle-to-vehicle communication device, and determines whether or not there is a third vehicle ahead in a traveling direction of the second vehicle based on the first position and a second position that is set in front of the intersection on a road on which the second vehicle is traveling.

Advantageous Effects of Invention

According to the present invention, it is possible to provide a technique for estimating the presence of a vehicle incapable of vehicle-to-vehicle communication ahead of a vehicle-to-vehicle communication partner vehicle.

Problems, configurations, operations, and effects of the present invention other than those described above will be clarified by the following description of embodiments.

DESCRIPTION OF EMBODIMENTS

First Embodiment

FIG.1is a system configuration diagram of a vehicle-to-vehicle communication system according to a first embodiment of the present invention.FIG.2is a flowchart of a process executed in the vehicle-to-vehicle communication system according to the first embodiment of the present invention.

FIG.3is a diagram for describing an operation when the vehicle-to-vehicle communication system according to the first embodiment is applied to prevention of a collision accident at an intersection.

A vehicle10inFIG.3is a host vehicle (first vehicle), and is a vehicle equipped with the system illustrated inFIG.1. A vehicle11is a vehicle capable of transmitting its vehicle information (collectively referred to as data acquired by the vehicle11and including, for example, location data and velocity data) to the host vehicle10, and is equipped with a vehicle-to-vehicle communication device (wireless communication device)34(FIG.1). The vehicle11is a communicating vehicle (second vehicle) communicating with the host vehicle10in the vehicle-to-vehicle communication. The vehicle (third vehicle)13is a vehicle that cannot transmit its vehicle information (collectively referred to as data acquired by the vehicle13and including, for example, location data and velocity data) to the host vehicle10, and is a vehicle that is not equipped with the vehicle-to-vehicle communication device34, for example.

Here, the host vehicle10on which the system illustrated inFIG.1is mounted will be described.

As illustrated inFIG.1, the host vehicle10includes a GNSS receiver31and a map database32. GNSS is an abbreviation for Global Navigation Satellite System. The GNSS receiver31calculates location data (first location data) of the host vehicle10based on signals (navigation signals) from a plurality of positioning satellites received by an antenna. The map database32stores, as map data, location data of roads and intersections, and the like. The map database32may be stored in an external storage device capable of communicating with a control device30or may be stored in a storage device in the control device30.

The host vehicle10includes a vehicle-to-vehicle communication device34which is a wireless communication device. By using the vehicle-to-vehicle communication device34to communicate with another vehicle (for example, a vehicle-to-vehicle communication partner vehicle11(hereinafter, also referred to as a communication partner vehicle11)) also including the vehicle-to-vehicle communication device34, it is possible to transmit and receive vehicle information to and from the other vehicle. The vehicle information may include, for example, vehicle location data calculated by the GNSS receiver31, vehicle velocity data detected by a speed sensor, and brake data detected by a brake pedal operation amount sensor. The brake data may include, for example, a timing at which a brake operation is performed on the brake pedal and an operation amount (depression amount) of the brake operation.

The control device30is mounted on the host vehicle (first vehicle)10. The control device30controls the host vehicle10based on vehicle information of another vehicle (for example, the vehicle (second vehicle)11) received by the vehicle-to-vehicle communication device34. The control device30is, for example, an electronic control device (ECU). The control device30can calculate at which location on the map the host vehicle10exists based on the current position of the host vehicle10obtained from the GNSS receiver31and the map data from the map database32. In addition, the control device30can detect an intersection present ahead in the traveling direction of the host vehicle10using the location data of the host vehicle10acquired from the GNSS receiver31and the location data of the intersection acquired from the map database32.

The control device30can execute a plurality of processes33,35,36,37, and38indicated by blocks inFIG.1. The control device30includes an arithmetic device such as a CPU that executes a program and a storage device including a volatile memory and a nonvolatile memory, such as a RAM and a ROM. The control device30may have a configuration in which a program stored in the storage device is executed by the arithmetic device. The control device30may be configured in such a manner that processing is executed with hardware such as a logic circuit. The control device30may be configured to execute processing by a combination of software and hardware.

The process (intersection detection process)33of the control device30can detect, on the map data, an intersection60(seeFIG.3) located ahead in the traveling direction of the host vehicle10based on the current position (location data) of the host vehicle10acquired from the GNSS receiver31and the map data acquired from the map database32. In addition, the control device30can detect that the host vehicle10is approaching the intersection60on the map (for example, that the distance between the host vehicle10and the intersection60is getting shorter or become a predetermined value or less).

The process (partner vehicle information acquisition process)35of the control device30is to acquire the vehicle information of the communication partner vehicle from the vehicle of the communicating partner (for example, the communication partner vehicle11) by communicating via the vehicle-to-vehicle communication device34. The vehicle information includes at least location data of the communication partner vehicle. The velocity data and brake data may be included.

The process (stop position estimation process)36of the control device30is to calculate (estimate) a stop position (which may be referred to as a first stop position or a first position) when the vehicle (second vehicle) of the communication partner stops before the intersection60, based on the vehicle information (second vehicle information) of the vehicle (second vehicle (for example, the communication partner vehicle11)) traveling toward the intersection60detected in the process33on a route different from the host vehicle10, from pieces of the vehicle information of the communication partner vehicle acquired in the process35.

The process (a process for determining whether there is another vehicle)37of the control device30determines whether there is another vehicle (a third vehicle (for example, the vehicle13)) ahead in the traveling direction of the other vehicle (the second vehicle) based on a positional relationship between the stop position (the first stop position) of the communication partner vehicle (the second vehicle) calculated in the process36and the stop position (sometimes referred to as the second stop position or the second position) set before the intersection60on the road where the communication partner vehicle (the second vehicle) travels. More specifically, in the process37, when distance D between the second stop position and the first stop position (seeFIG.3) is greater than a predetermined value, it may be determined that another vehicle (third vehicle (for example, vehicle13)) is present.

In the process (predetermined control process)38of the control device30, the predetermined control process is performed on the host vehicle10when it is determined in the process37that there is another vehicle (third vehicle) ahead of the communication partner vehicle (second vehicle). The predetermined control process may include control of the host vehicle10and/or warning to the driver of the host vehicle10. The former control of the host vehicle10may include, for example, deceleration control and stop control of the host vehicle10by brake control of the host vehicle10. Examples of the latter warning include a warning display on a display (notification device) installed in the driver's seat of the host vehicle10and a warning sound output via a speaker (notification device) installed in the driver's seat of the host vehicle10.

When detecting an intersection60ahead in the traveling direction of the host vehicle10in the process33while the host vehicle10is traveling, the control device30of the host vehicle10acquires vehicle information including the location data of the communication partner vehicle11from the communication partner vehicle11located around the intersection via the vehicle-to-vehicle communication using the vehicle-to-vehicle communication device34. The communication partner vehicle11(second vehicle) in the example ofFIG.3is traveling toward the intersection60on a second road62(a road different from a first road61) intersecting the intersection60located ahead in the traveling direction of the host vehicle10(first vehicle) traveling on the first road61.

The control device30of the host vehicle10estimates an estimated stop position (first stop position)71(seeFIG.3) that is a position where the communication partner vehicle (second vehicle)11is estimated to stop based on the vehicle information including location data of the communication partner vehicle11acquired via the vehicle-to-vehicle communication. The first stop position71can be calculated based on location data and velocity data (vehicle information of the communication partner vehicle11) of the communication partner vehicle (second vehicle)11.

An intersection area (predetermined region)20is preset on the second road62on which the communication partner vehicle (second vehicle)11travels. A second stop position72is preset in the intersection area20. The second stop position72is set on the second road62before the intersection60(an area close to second vehicle11with intersection60as a reference). The intersection area20inFIG.3is set on the second road62so as to include the entire intersection60. However, the intersection area20is not limited to that illustrated inFIG.3. For example, the intersection area20may be set on the second road62so as to be adjacent to the intersection60as in a rectangular region22inFIG.3, or may be set on the second road62so as to include a part of the intersection60as in a fan-shaped region23inFIG.3. A point21inFIG.3is a center point of the circular intersection area20.

In a case where the estimated stop position (first stop position)71is outside the intersection area20(seeFIG.3), the control device30of the present embodiment determines that there is the vehicle13for which vehicle-to-vehicle communication is not available (this can also be referred to as a vehicle13whose location data the host vehicle10cannot acquire) ahead of the communication partner vehicle11.

The purpose of setting the intersection area20in this manner is that, by determining whether or not the first stop position71is outside the intersection area20, it can be easily determined whether or not the distance D (seeFIG.3) between the first stop position71and the second stop position72exceeds a predetermined value. In other words, these two determination methods essentially determine the same. The “predetermined value” in this case is a distance between the first stop position and the second stop position in a case where the foremost part of second vehicle11is located on the boundary line of intersection area20.

The intersection area20in the example ofFIG.3is a circular region centered on the center21, which is the center position of the intersection detected in the process33, and having a radius of a predetermined distance corresponding to data (intersection scale data) indicating the size of the intersection60, data of a general size of various vehicles, and the like. The intersection scale data may include, for example, data such as a road width of a road and the number of roads that intersect in the intersection.

In a case where the control device30determines that there is the vehicle13incapable of vehicle-to-vehicle communication, the control device performs warning such as warning to the driver of the host vehicle10and/or performs deceleration control when the host vehicle10passes through the intersection60. As a result, the host vehicle10can pass through the intersection60without coming into contact with another vehicle (for example, the vehicle13).

The processes executed by the control device30will be further described with reference to the flowchart ofFIG.2.

The control device30executes the flowchart ofFIG.2at a predetermined cycle, calculates the location of the host vehicle10based on the data of the GNSS receiver31and the map database32, and executes the process33to detect the intersection60while the host vehicle10is traveling in step S101. The control device30repeats step S101when any intersection cannot be detected, and proceeds to step S102when the intersection60is detected.

In step S102, the control device30starts vehicle-to-vehicle communication using the vehicle-to-vehicle communication device34with the communication partner vehicle11approaching the intersection60detected in step101from, for example, a route different from the host vehicle10.

In step S103, the control device30acquires vehicle information (including, location data and velocity data for example) of the communication partner vehicle11by the process35, and calculates an estimated stop position (first stop position)71of the communication partner vehicle11before the communication partner vehicle11passes through the intersection60detected in step101(for example, the time at which the host vehicle10is estimated to pass through the intersection may be calculated and set based on the velocity data) by the process36. For example, the control device30can obtain the estimated stop position (first stop position)71by calculation based on the current position of the communication partner vehicle11included in the location data and the velocity data of the communication partner vehicle11included in the vehicle information. The control device30can more accurately obtain the estimated stop position (first stop position)71by considering the brake data of the communication partner vehicle11included in the vehicle information.

In step S104, the control device30determines in the process36whether the estimated stop position (first stop position)71of the communication partner vehicle11estimated in the process37is outside the intersection area20. The control device30proceeds to step S105when the determination result in step S104is YES (when it is determined that the estimated stop position71is outside the intersection area20), and proceeds to step S107when the determination result is NO (when it is determined that the estimated stop position71is not out of the intersection area20).

In step S105, the control device30determines, in the process37, that there may be the vehicle13that cannot perform vehicle-to-vehicle communication ahead of the communication partner vehicle11that is outside the intersection area20and stopped. In this case, whether the vehicle13enters the intersection cannot be determined on the host vehicle10side based on the location data of the vehicle13. Therefore, in some cases, a possibility that the host vehicle10comes into contact with the vehicle13when passing through the intersection cannot be denied.

In step S106, since there is a possibility of occurrence of a collision accident in which the host vehicle collides with another vehicle (the vehicle13in the case through step S105, and the communication partner vehicle11in the case through later described step S108), the control device30alerts the driver of the host vehicle10by outputting a warning sound or the like in the process38. Instead of or in addition to the alerting process, the vehicle may be decelerated by brake control to ensure safety when passing through the intersection.

On the other hand, in step S107, the control device30determines that there is no possibility that the vehicle13incapable performing vehicle-to-vehicle communication enters the intersection from the side of the intersection when the host vehicle10passes through the intersection.

In step S108, the control device30determines that there is no vehicle13incapable of vehicle-to-vehicle communication, but there is a possibility of contact with the communication partner vehicle11. Therefore, the control device30confirms the vehicle information (including the location data and the velocity data) of the communication partner vehicle11again in the process35, and determines whether there is a possibility that the communication partner vehicle11enters the intersection in the process36. The control device30can perform the determination in step S108based on, for example, three of the location of the communication partner vehicle11, the velocity of the communication partner vehicle11, and the distance between the communication partner vehicle11and the intersection. In the host vehicle10, the process proceeds to step S106when the determination result in step S108is YES (when it is determined that the communication partner vehicle11is likely to enter the intersection), and proceeds to step S109when the determination result is NO (when it is determined that the communication partner vehicle11is not likely to enter the intersection).

In step S109, according to the determination in the process37and the vehicle information (including the location data and the velocity data) of the communication partner vehicle11acquired in the process35, since there is no vehicle13incapable of performing vehicle-to-vehicle communication, and there is no possibility of a collision accident with the communication partner vehicle11, the control device30determines that the vehicle can safely pass through the intersection at the current speed.

As described above, according to the present embodiment, even when there is the vehicle13that cannot perform vehicle-to-vehicle communication ahead of the communication partner vehicle11of vehicle-to-vehicle communication, the host vehicle10can detect the presence of the vehicle13that cannot perform the vehicle-to-vehicle communication. In addition, when detecting that there is the vehicle13incapable of vehicle-to-vehicle communication, the host vehicle10performs alerting the driver, deceleration control, and the like. As a result, the host vehicle10can pass through the intersection without coming into contact with the vehicle13incapable of vehicle-to-vehicle communication.

Second Embodiment

FIG.4is a flowchart of a process executed in the vehicle-to-vehicle communication system according to a second embodiment of the present invention.FIG.5is a diagram for explaining the operation of the vehicle-to-vehicle communication system according to the second embodiment of the present invention. Note that the configurations ofFIGS.1and3used in the first embodiment are the same in the second embodiment, and thus the following description will be made with reference toFIGS.1and3.

An outline of the second embodiment will be described with reference toFIG.5.FIG.5is a diagram illustrating a distance from the communication partner vehicle11to a specified stop position50(for example, a position of a stop line before entering an intersection) with respect to an elapsed time from a timing51, which is a timing at which the host vehicle10starts vehicle-to-vehicle communication with the communication partner vehicle11. Note that, according to the present embodiment, the specified stop position50is the second position.

The control device30of the host vehicle10acquires the vehicle information (including location data, velocity data, and brake data) of the communication partner vehicle11which is the communication partner after the timing51when the vehicle-to-vehicle communication is started. The control device30of the host vehicle10calculates, based on the acquired vehicle information of the communication partner vehicle11, a deceleration start estimation timing52which is a timing at which it is estimated that deceleration (brake operation) needs to be started in order for the communication partner vehicle11to stop at the specified stop position50, an estimated path53which is estimated values of subsequent position changes of the communication partner vehicle11, and a stop time (which may be referred to as a reference time)57which is a time when the communication partner vehicle11stops at the specified stop position50.

The control device30of the host vehicle10calculates a timing (brake operation detection timing)54at which the brake operation is performed in the communication partner vehicle11based on the brake data included in the acquired vehicle information of the communication partner vehicle11. The brake data includes, for example, an operation amount of the brake pedal (a depression amount of the brake pedal) of the communication partner vehicle11detected by an operation amount sensor, and the brake operation detection timing54can be calculated based on the brake data. When the brake operation detection timing54is earlier than the deceleration start estimation timing52, the control device30of the host vehicle10calculates the stop position (first position)58of the communication partner vehicle11at the reference time (stop time) calculated before the brake operation detection timing54based on the vehicle information (including the location data and the velocity data) of the communication partner vehicle11acquired by the vehicle-to-vehicle communication after the brake operation detection timing54(that is, after the brake operation).

In calculating the stop position58, the control device30may calculate a path55that is location changes of the communication partner vehicle11after the brake operation detection timing54. The path55may be an estimated path calculated based on the location data and velocity data (vehicle information) of the communication partner vehicle11, or may be an actual path defined by actual location data of the communication partner vehicle11. The former method is advantageous in that the stop position58can be calculated earlier than the latter method, and the latter method is advantageous in that the stop position58can be calculated more accurately than the former method.

Next, the control device30of the host vehicle10calculates a distance D56between the stop position (first position)58of the communication partner vehicle11and the specified stop position (second position)50at the reference time (stop time), and determines whether or not the distance exceeds a predetermined value dl. The predetermined value dl can be determined based on the length of one vehicle, and can be longer than the length of one vehicle.

In a case where the distance D56exceeds the predetermined value dl, the control device30determines that the communication partner vehicle11stops before the specified stop position50and there is the vehicle13incapable of vehicle-to-vehicle communication ahead of the communication partner vehicle11. As a result, the control device30performs alerting the driver of the host vehicle10or deceleration control, similarly to the first embodiment.

Note that the specified stop position50is not limited to the stop line at the intersection60, and may be another stop line, a boundary line of the intersection, or any other position where the vehicle should stop.

The processes executed by the control device30according to the second embodiment will be further described with reference to the flowchart ofFIG.4. The same processes as those in the flowchart ofFIG.1are denoted by the same reference numerals, and the description thereof may be omitted as appropriate.

In step201, the control device30calculates the deceleration start estimation timing52and the stop time (reference time)57when the communication partner vehicle11stops at the specified stop position50based on the location data and the velocity data (vehicle information) of the communication partner vehicle11acquired from step S102.

In step202, the control device30starts to detect whether or not the brake operation has been performed on the communication partner vehicle11based on the brake data (vehicle information) of the communication partner vehicle11acquired from step S102. In a case where the brake operation is detected, the process proceeds to step S203, and otherwise, the process remains in step S202.

In step203, the control device30determines whether or not the brake operation detection timing54detected in step S202is earlier than the deceleration start estimation timing52calculated in step S201. If the brake operation detection timing54is earlier than the deceleration start estimation timing52, the process proceeds to step S204, and if not, the process proceeds to step S107.

In step204, the control device30calculates the stop position (first position)58of the communication partner vehicle11at the stop time57calculated in step S201based on the location data and the velocity data (vehicle information) after the brake operation among the location data and the velocity data (vehicle information) of the communication partner vehicle11acquired in step S102.

In step205, the control device30calculates the distance D56between the stop position (first position)58calculated in step S204and the specified stop position (second position)50, and determines whether or not the distance D56exceeds a predetermined value dl. When it is determined that the distance D56exceeds the predetermined value dl, the process proceeds to step S105to perform the process for a case where another vehicle13is present ahead of the communication partner vehicle11. Otherwise, the process proceeds to step S107to perform the process for a case where another vehicle13is not present. Since the subsequent processes are the same as those of the first embodiment, the description thereof is omitted.

With the processes of the control device30described above, the presence of the vehicle13can be detected even when there is the vehicle13incapable of vehicle-to-vehicle communication ahead of the communication partner vehicle11, as in the first embodiment. According to the present embodiment, since the stop time (reference time)57is calculated in real time and the distance D56at that time is calculated, the detection accuracy of the vehicle13can be improved as compared with the first embodiment. Furthermore, according to the present embodiment, since the process of detecting the vehicle13is performed only when the brake operation is detected, the detection accuracy of the vehicle13can be improved also from this viewpoint.

Third Embodiment

Next, a third embodiment which is a modification of the second embodiment will be described.FIG.6is a flowchart of processes executed by the control device30according the third embodiment of the present invention.FIG.7is a diagram for explaining the operation of the vehicle-to-vehicle communication system according to the third embodiment of the present invention.

According to the second embodiment, the presence or absence of the vehicle13is detected from the distance D between the first position (specified stop position)50and the second position (stop position)58when the communication partner vehicle11stops (stop time57). However, according to the third embodiment, the presence or absence of the vehicle13is detected from the distance D between the first position (passing position71) and the second position (specified passing position72) at a predetermined time (passing time59) before the communication partner vehicle11stops (while traveling).

The processes executed by the control device30according to the third embodiment will be further described with reference to the flowchart ofFIG.6. Description of the same processes as those in the flowcharts ofFIGS.2and4may be omitted.

In step301, the control device30calculates a deceleration start estimation timing52when the communication partner vehicle11stops at the specified stop position50and a passing time (reference time)59(seeFIG.7) at which the communication partner vehicle11passes through the specified passing position (second position)72(seeFIG.7) based on the location data and the velocity data (vehicle information) of the communication partner vehicle11acquired from step S102. The calculation of the passing time (reference time)59is performed as follows. In other words, as mentioned in the description of the second embodiment, the control device30calculates the estimated path53, which is estimated values of the location changes of the communication partner vehicle11, based on the location data and the velocity data (vehicle information) of the communication partner vehicle11acquired in step S102, searches for and detects the time of passing through the specified passing position (second position)72separately set in advance from the estimated path53, and sets the detected time as the passing time (reference time)59. Only the passing time59may be determined in advance without setting the specified passing position72in advance. For example, the passing time (reference time)59may be after a lapse of a predetermined time from the deceleration start estimation timing52.

Although the description of steps S202,203following step S301is simplified, if the brake operation detection timing54of the communication partner vehicle11is earlier than the deceleration start estimation timing52, the process proceeds to step S302.

In step302, the control device30calculates the passing position (first position)71of the communication partner vehicle11at the passing time (reference time)59calculated in step S301based on the location data and the velocity data (vehicle information) after the brake operation among the location data and the velocity data (vehicle information) of the communication partner vehicle11acquired from step S102.

In step303, the control device30calculates the distance D56between the passing position (first position)71calculated in step S302and the specified passing position (second position)72, and determines whether or not the distance D56exceeds a predetermined value dl. When it is determined that the distance D56exceeds the predetermined value dl, the process proceeds to step S105to perform the process for a case where another vehicle13is present ahead of the communication partner vehicle11. Otherwise, the process proceeds to step S107to perform the process for a case where another vehicle13is not present. Since the subsequent processes are the same as those of the first embodiment, the description thereof is omitted.

With the processes of the control device30described above, the presence of the vehicle13can be detected even when there is the vehicle13incapable of vehicle-to-vehicle communication ahead of the communication partner vehicle11, as in the first embodiment. In particular, according to the present embodiment, since the vehicle13can be detected before the communication partner vehicle11stops, the excellent immediacy is an advantage.

The embodiments described above are merely examples, and the present invention is not limited to these contents as long as the features of the invention are not impaired. The present invention is not limited to the above-described embodiments, and combinations thereof and other aspects conceivable within the scope of the technical idea of the present invention are also included in the scope of the present invention.

For example, although the intersection60of the above embodiment is a cross (four-way junction), the intersection may be a multi-way junction including a three-way junction and a five-way junction.

According to the above embodiment, the vehicle11and the vehicle13approach the intersection60via a route different from that of the host vehicle10, but it is also possible to detect the vehicle13ahead of the vehicle11even when the vehicle11and the vehicle13approach the intersection60via the same route.

REFERENCE SIGNS LIST