JP4760673B2 - Vehicle-to-vehicle communication system and vehicle-to-vehicle communication device - Google Patents

Description

  The present invention relates to a vehicle-to-vehicle communication system capable of appropriately performing communication between vehicles even when there are a plurality of vehicles ahead or when the light of an oncoming vehicle is received as noise.

2. Description of the Related Art Conventionally, there is known a travel control device that grasps a traffic situation ahead by information communication between vehicles and controls various devices existing in the vehicle based on this information.
In such a travel control device, a receiving means for receiving information from another vehicle existing ahead, and a transmission for transmitting the result of processing the information of the preceding vehicle and the own vehicle to another vehicle existing behind. Vehicle and vehicle information processing means connected to various controllers existing in the host vehicle, collecting information on surrounding vehicles and controlling the various controllers in the vehicle to support safe driving of the host vehicle There is a travel control device by communication (see, for example, Patent Document 1).

Further, in such a travel control device, a front light projecting / receiving unit that receives or transmits a laser light signal to the front of the vehicle, and a rear light projecting / receiving unit that receives or transmits a laser light signal to the rear of the vehicle, The laser beam signal including the signal received by the front light projecting and receiving unit is transmitted from the rear light projecting and receiving unit, and the laser beam signal including the signal received by the rear light projecting and receiving unit is transmitted from the front light projecting and receiving unit. There is a travel control device that enables signal forwarding between vehicles by providing a signal relay unit that relays a signal between a light receiving unit and a rear light projecting / receiving unit (see, for example, Patent Document 2).
JP 05-266399 A (3rd and 4th pages, FIG. 1) Japanese Patent Laid-Open No. 09-051309 (pages 3, 4 and FIG. 1)

  However, the above-described travel control device has a problem that when there are a plurality of vehicles ahead, the laser light is easily blocked by the vehicles, and thus it is difficult to appropriately perform light communication between vehicles. It was. Further, even when the light of the oncoming vehicle is received as noise, there is a problem in that it is difficult to appropriately perform communication using laser light between vehicles.

  The present invention has been made in view of such problems, and an object thereof is to provide a vehicle-to-vehicle communication system that appropriately performs communication between vehicles even when a plurality of vehicles are present ahead. It is in.

  The inter-vehicle communication system according to claim 1 made to solve the above-mentioned problem is characterized in that “communication with surrounding vehicles is performed based on communication conditions set for each vehicle”. The “communication conditions set for each vehicle” here means “control the communication distance in the front-rear direction according to the speed of the vehicle”, “the communication range in the left-right direction according to the number of lanes traveling ( "Determining the distance", and "position information of the communication partner for determining the communication partner and focusing communication with the partner communication device".

Specifically, the inter-vehicle communication system is configured by a plurality of inter-vehicle communication devices that are mounted on a vehicle and communicate with each other. Each inter-vehicle communication device (1: In this column, in order to facilitate understanding of the invention, the reference numeral used in the column “Best Mode for Carrying Out the Invention” is attached as necessary. of not meant to limit the scope.) were respectively, the communication wavelength storing means for storing the communication wavelength allocated to each vehicle (22), mounted around vehicles existing ambient other Communication means (14, 16, 18, 20) for performing communication with the vehicle-to-vehicle communication device, and communication control means (26). The water and the temperature on the road during communication, in accordance with the illuminance condition of sunlight, the amplification rate and the modulation method of communication waves may be adjusted. For example, when the weather is dense fog, for example, the attenuation due to moisture differs depending on the wavelength, so the wavelength dependency of the amplification factor is set. Then, the communication control means transmits various information to and controls the communication means other vehicle-to-vehicle communication device by the communication wavelength assigned to the vehicle to be stored in the communication wavelength storing means, the communication wavelength storing means at communication wavelength allocated to nearby vehicles to store received and controls the communication unit of each species the same kind of information transmitted from another vehicle-to-vehicle communication device.

  In the conventional travel control device, when there are a plurality of vehicles ahead, laser light is easily blocked by the vehicles, and thus there is a problem that it is difficult to appropriately perform light communication between vehicles. Further, even when the light of the oncoming vehicle is received as noise, there is a problem in that it is difficult to appropriately perform communication using laser light between vehicles. On the other hand, according to the inter-vehicle communication system of the present invention, communication conditions set for each vehicle (particularly, “control the communication distance in the front-rear direction according to the speed of the vehicle” and “the number of lanes to travel” Accordingly, communication with the surrounding vehicle is performed based on the determination of the communication range (distance) in the left-right direction according to the above. Therefore, even when there are a plurality of vehicles ahead, communication can be appropriately performed between the vehicles.

Also, for the communication wavelength to be used for the communications described above, it is considered that it is at least four sets (claim 2). In this way, different types of wavelengths can be assigned to adjacent vehicles and own vehicles.

By the way, when there are many surrounding vehicles traveling around the vehicle, it is necessary to communicate with many vehicles at the same time, and there is a problem that the load of the communication control means of the inter-vehicle communication device becomes large.
Therefore, it is conceivable to communicate with a preceding vehicle within a predetermined range. Specifically, as in claim 3 , the inter-vehicle communication device further includes vehicle speed detection means (10, 12) for detecting the traveling speed of the vehicle on which the inter-vehicle communication device is mounted, and vehicle speed detection means. Detection range setting means (26) for setting a detection range for detecting surrounding vehicles traveling around in accordance with the detected traveling speed, and other vehicles within the detection range set by the detection range setting means Vehicle presence determination means (26) for determining whether or not the vehicle exists, and the communication control means of the inter-vehicle communication device determines that another vehicle exists within the detection range by the vehicle presence determination means. It can be considered that the vehicle is regarded as a surrounding vehicle and communicates only with the inter-vehicle communication device mounted on the surrounding vehicle.

  In this way, it is possible to limit the number of vehicles that communicate at the same time by setting only the vehicles existing within the detection range as communication targets, and increase the load of the communication control means of the inter-vehicle communication device. Can be prevented.

When the traveling speed of the vehicle is high, the inter-vehicle distance is widened, so that the number of vehicles existing in the above-described detection range is reduced, and there is a possibility that inter-vehicle communication cannot be performed. On the other hand, when the traveling speed of the vehicle is low, the inter-vehicle distance is narrowed, so that the number of vehicles existing in the above-described detection range increases, and it is necessary to communicate with many vehicles at the same time. There is a problem that the load on the control means increases. Thus, it is conceivable to set the detection range according to the traveling speed of the vehicle. Specifically, as in claim 4 , the detection range setting means of the inter-vehicle communication device widens the detection range when the traveling speed of the vehicle detected by the vehicle speed detection means increases, It is conceivable that the detection range is narrowed when the traveling speed of the vehicle becomes small. In this way, it can be expected that the number of surrounding vehicles existing within the detection range is appropriately maintained.

  By the way, while the vehicle is traveling, the same surrounding vehicle may enter or leave the detection range within a predetermined time. In such a case, the process regarding the surrounding vehicle is repeated, and there is a possibility that the load on the communication control means of the inter-vehicle communication device becomes large.

Therefore, if a “staggered state” in which the same surrounding vehicle enters or exits the detection range within a predetermined time is detected, the surrounding vehicle may not be a target for switching the communication wavelength. . Specifically, as in claim 5 , the inter-vehicle communication device further determines whether or not the surrounding vehicle determined to be present within the detection range by the vehicle presence determining unit is in the wobble state. (26), when the communication control means of the vehicle-to-vehicle communication device is determined to be in a wobble state by the wobble determination device, the vehicle-to-vehicle communication device mounted in the surrounding vehicle switches the communication wavelength. It is possible not to do it.

  In this way, even when a “fluctuation state” in which the same surrounding vehicle enters or exits within the detection range within a predetermined time is detected, frequent communication wavelength switching processing for the surrounding vehicle is repeated. As a result, it is possible to prevent the load on the communication control means of the inter-vehicle communication device from increasing.

By the way, for example, the communication wavelength assigned to the surrounding vehicle is changed to the same communication wavelength as that assigned to the own vehicle according to the communication wavelength assigned to the vehicle traveling around the surrounding vehicle. Sometimes. In this case, it is conceivable to change the communication wavelength assigned to the own vehicle to a communication wavelength different from the communication wavelength assigned to the surrounding vehicle. Specifically, as in claim 1 , the inter-vehicle communication device further refers to the storage content stored in the communication wavelength storage means and the communication wavelength assigned to the own vehicle and the communication wavelength assigned to surrounding vehicles. And the same judgment means (26) for judging whether or not the communication wavelength assigned to the vehicle and the communication wavelength assigned to the surrounding vehicle are the same. The communication wavelength storage means stores the communication wavelength assigned to the own vehicle after changing the wavelength assigned to the own vehicle so as not to be the same as the communication wavelength assigned to the surrounding vehicle. First storage control means (26) for updating the contents, and the communication control means of the inter-vehicle communication device controls the communication means to the surrounding vehicles for information on the communication wavelength assigned to the vehicle after the change. Then send Rukoto is considered. In this case, from the viewpoint of preventing adjacent neighboring vehicles from having the same wavelength, it is preferable that at least four types of communication wavelengths be used as described above.

In this way, the communication wavelength assigned to the vehicle can be maintained at a wavelength different from the communication wavelength assigned to the surrounding vehicle.
Further, for example, when the communication wavelength assigned to the surrounding vehicle is changed according to the communication wavelength assigned to the vehicle traveling around the surrounding vehicle, the storage content of the communication wavelength storage means is updated. It is preferable to keep it. Specifically, as in claim 6 , when the vehicle-to-vehicle communication device further receives a notification from another vehicle-to-vehicle communication device that the communication wavelength assigned to the surrounding vehicle has been changed, It is conceivable to include second storage control means (26) for updating the storage content of the communication wavelength storage means to the communication wavelength assigned to the surrounding vehicle after the change.

If it does in this way, the communication wavelength allocated to the own vehicle can be maintained at a communication wavelength different from the communication wavelength allocated to the surrounding vehicle.
By the way, when a plurality of vehicles approach within the set range, the vehicles switch the communication frequency so that interference does not occur. Further, the electromagnetic wave transmitted by the communication means described above is attenuated by the communication distance in an empty space. However, when communication is performed between vehicles traveling on the road, if electromagnetic waves are transmitted without considering the directivity of the electromagnetic waves, the electromagnetic waves may be reflected by vehicles or road structures and the like, which may interfere with communication.

Thus, it is conceivable to transmit electromagnetic waves toward the communication means of the transmission source device. Specifically, as in claim 7 , the communication means is configured to be able to change the transmission direction of the electromagnetic wave to be transmitted, and the communication control means is configured to change the various information based on the various information received by the communication means. It is conceivable that the position of the communication means included in the vehicle-to-vehicle communication apparatus that is the transmission source is specified, and the communication means is controlled to transmit electromagnetic waves toward the communication means of the vehicle-to-vehicle communication apparatus that is the specified transmission source.

  If comprised in this way, there exist the following effects. That is, as an example, since the height direction of a vehicle is different between a normal vehicle and a large vehicle, there is a case where the position of the communication device of the large vehicle viewed from the normal vehicle becomes a position to look up as the distance approaches. Therefore, it receives the installation position information of the communication device of the other vehicle, and performs communication aiming at the communication device of the other vehicle based on the data. In this case, the installation position of the communication device of the other vehicle is included in the communication data to the approaching vehicle. The position of the vehicle is the position of the center of gravity of the vehicle (this is not the position of the center of gravity but the center position of the tip), and the positions of a plurality of communication devices are represented by offset values. When the communication device position is set in this way, the communication device that transmits the vehicle can easily determine the position of the communication device of the other party by numerical calculation. Can be done.

A vehicle-to-vehicle communication device for use in a vehicle-to-vehicle communication system according to any one of claims 1 to 7 , as described in claim 8 , wherein the vehicle-to-vehicle communication device according to any one of claims 1 to 7 is used. If it is a vehicle-to-vehicle communication device having the configuration described with respect to the vehicle-to-vehicle communication device, the effects as described above can be derived by using in combination.

Embodiments of the present invention will be described below with reference to the drawings.
[First embodiment]
FIG. 1 is a block diagram showing a schematic configuration of a vehicle-to-vehicle communication device 1 used by being mounted on a vehicle. Moreover, FIG.2 (b) is explanatory drawing for demonstrating clearly the difference in the color of light using visible light as an example of the difference in communication wavelength. FIG. 3 (a) is an explanatory diagram (1) showing communication areas of the front measurement radar and the rear measurement radar of the inter-vehicle communication device in the own vehicle, and FIG. 3 (b) is in the own vehicle and surrounding vehicles. It is explanatory drawing which shows the communication area of the measurement radar for the front of a vehicle-to-vehicle communication apparatus, and the measurement radar for the back, FIG.3 (c) is the communication area of the measurement radar for the front of the vehicle-to-vehicle communication apparatus in the own vehicle, and the measurement radar for back. FIG. 3D is an explanatory diagram (3) showing communication areas of the front measurement radar and the rear measurement radar of the inter-vehicle communication device in the own vehicle.

[Description of Configuration of Inter-Vehicle Communication Device 1]
As shown in FIG. 1, the inter-vehicle communication device 1 includes a front measurement radar 10, a side measurement radar 12, a front transceiver 14, a rear transceiver 16, a left transceiver 18, and a right Transceiver 20, memory 22, external I / F 24, and communication control unit 26. The front measurement radar 10, the side measurement radar 12, the front transmitter / receiver 14, the rear transmitter / receiver 16, the left transmitter / receiver 18, the right transmitter / receiver 20, the memory 22, and the external I / F 24 are as follows. It is connected to the communication control unit 26 and configured to be able to communicate with each other.

[Description of Configuration of Front Measurement Radar 10 and Side Measurement Radar 12]
Among these, the front measurement radar 10 sends a millimeter wave, a laser, or the like toward the front of the vehicle on which the inter-vehicle communication device 1 is mounted, and receives a reflected wave from an object existing in front of the vehicle.

The side measurement radar 12 sends a millimeter wave, a laser, or the like toward the side of the vehicle on which the inter-vehicle communication device 1 is mounted, and receives a reflected wave from an object existing on the side of the vehicle.
The front measurement radar 10 and the side measurement radar 12 correspond to vehicle speed detection means.

[Description of the configuration of a transceiver such as the forward transceiver 14]
As illustrated in FIG. 3A and FIG. 3B, the forward transmitter / receiver 14 communicates with electromagnetic waves (light for communication) with other inter-vehicle communication devices mounted on surrounding vehicles traveling forward. A transmitter 14a that transmits radio waves forward, a receiver 14b that receives radio waves from the front, and a communication wavelength switch 14c that switches the wavelength of the radio waves. The transmitter 14a, the receiver 14b, and the communication wavelength switch 14c constitute a communication device 14d (see FIG. 11A). Moreover, as shown to Fig.11 (a), the transmitter / receiver 14 for front is provided with the above-mentioned communication apparatus 14d, the camera 14e, and the reflector 14f. And the communication apparatus 14d and the reflector 14f are comprised so that the attitude | position can be changed integrally. The forward transceiver 14 may be movable by a mechanism, or the louver shape may be moved by a mechanical method to limit the traveling direction of the electromagnetic wave, or the electromagnetic wave communication may be performed by controlling the phase. The direction may be controlled, or a combination of these may be used. The camera 14e is configured such that its posture can be changed independently of the communication device 14d and the reflector 14f. Thus, the forward transceiver 14 is configured to be able to change the transmission direction of the electromagnetic wave to be transmitted in the vertical direction and the horizontal direction. Moreover, the front transceiver 14 can identify each other's position by receiving the electromagnetic wave reflected by the other reflector after transmitting (refer FIG.11 (b)).

  As illustrated in FIG. 3A and FIG. 3B, the rear transceiver 16 transmits and receives electromagnetic waves for communication with other inter-vehicle communication devices mounted on surrounding vehicles that run behind the vehicle. A device that includes a transmitter (not shown) that transmits electromagnetic waves to the rear, a receiver (not shown) that receives electromagnetic waves from the rear, and a communication wavelength switch (not shown) that switches the wavelength of the radio waves. ing.

  Similarly to the front transceiver 14, the rear transceiver 16 includes a communication device, a camera, and a reflector having a transmitter, a receiver, and a communication wavelength switch. Detailed descriptions of the communication device, the camera, and the reflector are omitted here.

  As illustrated in FIG. 3C and FIG. 3D, the left transceiver 18 transmits and receives electromagnetic waves for communication with other inter-vehicle communication devices mounted on surrounding vehicles that run on the left. A device that transmits radio waves to the left (not shown), a receiver that receives electromagnetic waves from the left (not shown), a communication wavelength switcher (not shown) that switches the wavelength of radio waves, It has.

  Similarly to the forward transceiver 14, the left transceiver 18 includes a communication device, a camera, and a reflector having a transmitter, a receiver, and a communication wavelength switch. Detailed descriptions of the communication device, the camera, and the reflector are omitted here.

  As illustrated in FIG. 3C and FIG. 3D, the right transceiver 20 transmits and receives electromagnetic waves for communication with other inter-vehicle communication devices mounted on surrounding vehicles traveling on the right. A transmitter that transmits radio waves to the right (not shown), a receiver that receives electromagnetic waves from the right (not shown), and a communication wavelength switcher (not shown) that switches the wavelength of the radio waves. It is equipped with.

  Similarly to the forward transceiver 14, the right transceiver 20 includes a communication device, a camera, and a reflector having a transmitter, a receiver, and a communication wavelength switch. Detailed descriptions of the communication device, the camera, and the reflector are omitted here.

Note that the front transmitter / receiver 14, the rear transmitter / receiver 16, the left transmitter / receiver 18, and the right transmitter / receiver 20 correspond to communication means.
[Description of Configuration of Memory 22]
The memory 22 is composed of a nonvolatile memory and is used for storing various data. As illustrated in FIG. 1, the memory 22 is not used for determining the communication wavelength of the own vehicle, three pieces of wavelength determination target vehicle data for determining the wavelength of the own vehicle in the forward direction, and wavelength determination. There is a region where non-target vehicles detected by the radar are recorded. As for information about the vehicle and surrounding vehicles, for the vehicle, the ID of the vehicle used for communication (transmission), the communication (transmission) wavelength of the vehicle, the vehicle position (position designation ID: center of gravity, tip, rear End), installation position of the communication device installed in the vehicle (offset value from the vehicle position), traveling direction of the vehicle, lane information of the vehicle (width direction information), movement of the vehicle: Degree of fluctuation), and information indicating whether or not the communication of the vehicle is valid (ON or OFF), and for the surrounding vehicle, the ID of the surrounding vehicle, the communication (transmission) wavelength of the surrounding vehicle, Surrounding vehicle position (position designation ID: center of gravity, front end, rear end), installation position of a communication device mounted on the surrounding vehicle (offset value from the surrounding vehicle position), traveling direction of the surrounding vehicle, traveling lane information (width) of the surrounding vehicle Directional information), driving blur of surrounding vehicles: degree of fluctuation in speed , And information around the vehicle communication indicating whether a valid (ON or OFF), in constructed. Further, among the vehicles recognized by the front measurement radar 10 and the side measurement radar 12, the communication wavelength is also recorded in the memory 22 for the vehicle whose communication wavelength is confirmed. Further, in the memory 22, when the inter-vehicle distance or the side distance with the wavelength determination target vehicle increases, the data of the vehicle is moved and recorded in the recording area of the non-target vehicle. These data are updated regularly (in units of 10 milliseconds).

  The memory 22 is used to store communication wavelengths assigned to each vehicle. In this embodiment, as illustrated in FIG. 2B, four color optical communication devices of green (G), red (R), blue (B), and yellow (Y) are employed. However, five or more colors may be employed. The memory 22 is used to store communication conditions set in advance for each communication wavelength (corresponding to color in visible light) used by the vehicle for communication. In addition, as illustrated in FIG. 4, the memory 22 has a vehicle travel speed (km / hour), a limit distance F (m) that is a distance in the front-rear direction, and a limit distance M (m) that is a distance in the left-right width direction. Is stored in the “limit distance determination table”. The memory 22 corresponds to communication wavelength storage means and communication condition storage means.

  In the present embodiment, communication using visible light has been described as an example. However, four wavelengths that do not interfere can be used. Specifically, not only an infrared laser and a visible light laser but also a radio wave (medium wave, short wave, microwave, millimeter wave) can be selected as appropriate.

[Description of Configuration of External I / F 24]
The external I / F 24 is connected to other external devices and has a function of inputting / outputting information to / from these devices. In addition, it connects with various ECU (illustration omitted) as one of this external apparatus. As a result, the external I / F 24 can perform data communication with various ECUs via the in-vehicle LAN.

[Description of Configuration of Communication Control Unit 26]
The communication control unit 26 is configured around a well-known microcomputer comprising a CPU, ROM, RAM, I / O and a bus line connecting these components, and is based on a program stored in the ROM and RAM. Perform various processes.

  Further, the communication control unit 26 generates a transmission signal based on various data, causes the generated transmission signal to be transmitted as a radio wave to each transceiver at a communication wavelength assigned to the own vehicle, and other vehicle-to-vehicle communication devices. Has a function of transmitting data to the. At that time, the communication control unit 26 specifies the position of the transmitter / receiver included in the inter-vehicle communication device 1 that is the transmission source of the information related to the surrounding vehicle based on the information related to the surrounding vehicle received by each transmitter / receiver. Each transmitter / receiver is controlled to transmit electromagnetic waves toward the transmitter / receiver of the vehicle-to-vehicle communication device 1 that is a transmission source. In this case, the communication control unit 26 specifies the position of the transceiver with reference to the offset value included in the information related to the surrounding vehicle. More specifically, the position shifted by the offset value from the position of the center of gravity of the vehicle is regarded as the position of the transceiver (see FIG. 10B). Further, the communication wavelength assigned to the own vehicle is specified by referring to the storage contents of the memory 22. Further, the communication control unit 26 has a function of restoring data based on a reception signal output from each transmitter / receiver when each transmitter / receiver receives an electromagnetic wave emitted from another inter-vehicle communication device. The communication control unit 26 controls the front measurement radar 10 and the side measurement radar 12, and also transmits millimeter waves, lasers, and the like and the reflected waves transmitted from the front measurement radar 10 and the side measurement radar 12. It has a function of measuring the distance to an object existing in front of or on the side of the vehicle from the time until the vehicle returns.

  Further, the communication control unit 26 has a function of determining the wavelength of the electromagnetic wave transmitted by the transceivers 14, 16, 18, and 20 with reference to the stored contents of the memory 22. Moreover, the communication control unit 26 performs a communication wavelength change process and a vehicle-to-vehicle communication process.

  Further, the communication control unit 26 has the following operation. That is, for the detected vehicle, the amount of movement in the front-rear direction and the amount of movement in the lane width direction are periodically measured. When the measurement result is within the set range of the limit distance F (m) and the inter-vehicle distance increases or decreases, it is recorded in the memory 22 that the target vehicle has “blur” corresponding to the limit distance. For this blur width, data sampling is performed a set number of times to determine the blur tendency. In this case, a vehicle whose amount of blur monotonously increases and becomes larger than the set inter-vehicle distance is recorded in the “recording area of the non-target vehicle” in the memory 22, and further, the inter-vehicle distance with the own vehicle is increased and communication is performed. If the electromagnetic wave used is no longer detected, the data is deleted. On the other hand, when the amount of shake tends to vibrate, the vehicle is continuously recognized as a wavelength determination target vehicle. In this way, if no measures are taken, if the vehicle traveling ahead fluctuates around the set inter-vehicle distance, the communication wavelength of the own vehicle must be changed frequently. If the target vehicle is maintained, it is not necessary to frequently change the communication wavelength.

  The communication control unit 26 corresponds to a communication control unit, a detection range setting unit, a vehicle presence determination unit, a wobble determination unit, an identical determination unit, a first storage control unit, and a second storage control unit.

[Description of communication wavelength change processing]
Next, communication wavelength change processing executed by the communication control unit 26 of the inter-vehicle communication device 1 will be described with reference to the flowchart of FIG. 5 and FIG. FIG. 2A is an explanatory diagram for explaining the assignment of colors and communication wavelengths when visible light is used.

This communication wavelength changing process is executed when an ignition key is operated by the driver to enter the accessory power supply (ACC) state.
First, the information which shows the speed of the own vehicle is detected from the exterior of the inter-vehicle communication apparatus 1 via the external I / F 24 (S105).

  Subsequently, referring to the limit distance determination table (see FIG. 4) stored in the memory 22, the safe inter-vehicle distance F and the safe inter-vehicle distance M are set based on the traveling speed of the host vehicle (S110). For example, when the traveling speed is 50 km / hour, the limit distance F (m) that is the distance in the front-rear direction is set to a numerical value “50”, and the limit distance M (m that is the distance in the left-right width direction is set. ) Is set to a numerical value “7”. In this case, referring to the limit distance determination table, when the traveling speed of the host vehicle increases, the detection range is expanded, while when the traveling speed of the host vehicle decreases, the detection range is narrowed. Become. Based on the output signal from the front measurement radar 10, the distance from the own vehicle to the preceding vehicle is detected, and based on the output signal from the side measurement radar 12, the distance from the own vehicle to the side vehicle is determined. Detect (S115).

  Further, it is determined whether or not the distance from the host vehicle to the preceding vehicle is within the travel direction limit distance F (S120). If it is determined that the distance from the host vehicle to the preceding vehicle is not within the travel direction limit distance F (S120: NO), it is determined that the host vehicle and the preceding vehicle are not approaching, and the process returns to S105.

  On the other hand, if it is determined that the distance from the host vehicle to the preceding vehicle is within the travel direction limit distance F (S120: YES), it is determined that the host vehicle and the preceding vehicle are approaching, and then It is determined whether or not the distance from the host vehicle to the side vehicle is within the width direction limit distance M (S125). If it is determined that the distance from the host vehicle to the side vehicle is not within the width direction limit distance M (S125: NO), it is determined that the host vehicle is not approaching the side vehicle and the process returns to S105. .

  On the other hand, if it is determined that the distance from the host vehicle to the side vehicle is within the width direction limit distance M (S125: YES), it is determined that the host vehicle and the side vehicle are approaching, With reference to the data stored in the memory 22, it is determined whether or not the communication wavelength assigned to the own vehicle and the communication wavelength assigned to the preceding vehicle are the same (S130). If it is determined that the communication wavelength assigned to the host vehicle is not the same as the communication wavelength assigned to the preceding vehicle (S135: NO), the process returns to S105. On the other hand, when it is determined that the communication wavelength assigned to the own vehicle and the communication wavelength assigned to the preceding vehicle are the same (S135: YES), the type of color assigned to the own vehicle is set. While selecting the communication wavelength to change, the memory content regarding the own vehicle in the memory 22 is updated to the selected communication wavelength (S140). Then, the selected communication wavelength is transmitted to another vehicle via the external I / F 24 (S145). In that case, based on the various information which each transmitter / receiver received, the position of the transmitter / receiver with which the vehicle-to-vehicle communication apparatus 1 which is the transmission source of the various information is equipped is specified, and the vehicle-to-vehicle communication apparatus 1 which is the specified transmission source of Each transmitter / receiver is controlled to transmit electromagnetic waves toward the transmitter / receiver (see FIGS. 12 and 13).

  Further, it is determined whether or not there is a notification from the vehicle ahead to change the communication wavelength (S150). If it is determined that there is no notification from the preceding vehicle that the communication wavelength is to be changed (S150: NO), the system waits until it is determined that there is a notification from the preceding vehicle that the communication wavelength is to be changed. If it is determined that there is a communication to change the communication wavelength (S150: YES), the communication wavelength changed in the vehicle ahead is confirmed with reference to the communication (S155).

  And it is judged whether the communication wavelength changed in the front vehicle is the same as the communication wavelength allocated to the own vehicle (S160). When it is determined that the communication wavelength changed in the preceding vehicle is not the same as the communication wavelength assigned to the own vehicle (S160: NO), the process returns to S150. On the other hand, when it is determined that the communication wavelength changed in the preceding vehicle is the same as the communication wavelength assigned to the own vehicle (S160: YES), the communication wavelength assigned to the own vehicle is changed to another communication. The wavelength is changed (S165). Then, the selected communication wavelength is transmitted to another vehicle via the external I / F 24 (S170). In that case, based on the various information which each transmitter / receiver received, the position of the transmitter / receiver with which the vehicle-to-vehicle communication apparatus 1 which is the transmission source of the various information is equipped is specified, and the vehicle-to-vehicle communication apparatus 1 which is the specified transmission source of Each transmitter / receiver is controlled to transmit electromagnetic waves toward the transmitter / receiver (see FIGS. 12 and 13). Then, the process returns to S105.

[Description of inter-vehicle communication processing]
Next, the vehicle-to-vehicle communication process executed by the communication control unit 26 of the vehicle-to-vehicle communication device 1 will be described with reference to the flowchart in FIG. 6 and FIG. Note that FIG. 2A is an explanatory diagram illustrating communication wavelengths and assignment of communication wavelengths using visible light as an example.

This inter-vehicle communication process is executed when the ignition key is operated by the driver to enter the accessory power supply (ACC) state.
First, based on the output signal from the front measurement radar 10, it is determined whether or not there is a vehicle ahead (S205). If it is determined that no vehicle is present ahead (S205: NO), the process waits until it is determined that a vehicle is present ahead. On the other hand, when it is determined that there is a vehicle ahead (S205: YES), the distance to the vehicle ahead is measured based on the output signal from the front measurement radar 10 (S210). Subsequently, it is determined whether or not the distance to the vehicle ahead is a safe inter-vehicle distance (S215). Specifically, it is determined whether or not the distance from the host vehicle to the preceding vehicle is within the travel direction limit distance F.

  When it is determined that the distance from the host vehicle to the preceding vehicle is within the travel direction limit distance F, the host vehicle and the preceding vehicle are close to each other, and the distance between the preceding vehicle and the preceding vehicle is safe. It is determined that the distance is not reached (S215: NO). And the communication wavelength from the vehicle ahead is detected with reference to the memory content of the memory 22 (S220). If the communication wavelength from the vehicle ahead is not the same as the communication wavelength of the own vehicle (S225: YES), it is determined that there is no need to change the communication wavelength of the own vehicle, and the communication wavelength of the own vehicle is set to another Communication processing to be transmitted to the inter-vehicle communication device 1 is executed (S260). In that case, based on the various information which each transmitter / receiver received, the position of the transmitter / receiver with which the vehicle-to-vehicle communication apparatus 1 which is the transmission source of the various information is equipped is specified, and the vehicle-to-vehicle communication apparatus 1 which is the specified transmission source of Each transmitter / receiver is controlled to transmit electromagnetic waves toward the transmitter / receiver (see FIGS. 12 and 13). Then, the process proceeds to S205.

  On the other hand, when the communication wavelength from the preceding vehicle is the same as the communication wavelength of the own vehicle (S225: YES), it is determined that the communication wavelength of the own vehicle needs to be changed, and the communication wavelength of the own vehicle is set. The communication wavelength is changed to a communication wavelength different from the communication wavelength from the vehicle ahead, and the changed communication wavelength is stored in the memory 22 (S230). Furthermore, the communication process which transmits the communication wavelength after the change to the other inter-vehicle communication apparatus 1 is performed (S260). In that case, based on the various information which each transmitter / receiver received, the position of the transmitter / receiver with which the vehicle-to-vehicle communication apparatus 1 which is the transmission source of the various information is equipped is specified, and the vehicle-to-vehicle communication apparatus 1 which is the specified transmission source of Each transmitter / receiver is controlled to transmit electromagnetic waves toward the transmitter / receiver (see FIGS. 12 and 13). Then, the process proceeds to S205.

  By the way, when it is determined in S215 that the distance from the own vehicle to the preceding vehicle is not within the travel direction limit distance F, the own vehicle and the preceding vehicle are not close to each other, Is determined to be a safe inter-vehicle distance (S215: YES). And when the communication process which transmits the communication wavelength of the own vehicle to the other inter-vehicle communication apparatus 1 is not performed (S235: NO), it transfers to S205. On the other hand, when the communication process which transmits the communication wavelength of the own vehicle to the other inter-vehicle communication device 1 is performed (S235: YES), the degree of fluctuation of the inter-vehicle distance is determined (S240). Specifically, the amount of movement of the surrounding vehicle in the front-rear direction and the amount of movement in the lane width direction are periodically measured, and the measurement result is F or M as a value close to the travel direction limit distance F or the width direction limit distance M. When it is determined that there is a behavior that approaches or leaves, the operation is recorded as “blurring” in the memory 22, and the data is sampled a set number of times for this blur width, and the tendency of “blur” is determined. If the amount of blurring tends to vibrate, it is determined that there is a wobbling state. If it is determined that it is in the wobbling state (S245: YES), the communication processing for holding the communication wavelength of the own vehicle and transmitting it to the other inter-vehicle communication device 1 is executed as it is (S260). In that case, based on the various information which each transmitter / receiver received, the position of the transmitter / receiver with which the vehicle-to-vehicle communication apparatus 1 which is the transmission source of the various information is equipped is specified, and the vehicle-to-vehicle communication apparatus 1 which is the specified transmission source of Each transmitter / receiver is controlled to transmit electromagnetic waves toward the transmitter / receiver (see FIGS. 12 and 13). Then, the process proceeds to S205.

  On the other hand, when it is determined that the vehicle is not in a wobbling state (when the surrounding vehicle moves away from the host vehicle) (S245: NO), it is determined whether the communication stop condition is satisfied (S250), and the communication stop condition Is determined (S250: YES), the communication process is stopped (S255), and the process proceeds to S205.

  On the other hand, when it is determined that the communication stop condition is not satisfied (S250: NO), a communication process for transmitting the communication wavelength of the own vehicle to the other inter-vehicle communication device 1 is executed (S260). In that case, based on the various information which each transmitter / receiver received, the position of the transmitter / receiver with which the vehicle-to-vehicle communication apparatus 1 which is the transmission source of the various information is equipped is specified, and the vehicle-to-vehicle communication apparatus 1 which is the specified transmission source of Each transmitter / receiver is controlled to transmit electromagnetic waves toward the transmitter / receiver (see FIGS. 12 and 13). Then, the process proceeds to S205.

[Example of communication wavelength change processing and inter-vehicle communication processing]
Next, the communication wavelength changing process and the inter-vehicle communication process described above will be described with reference to FIGS. 7 to 9 by taking as an example a case where the vehicles A to E are traveling on a road having three lanes. . 7A is an explanatory diagram (1) showing an example in which the vehicles A to E are traveling on a road having three lanes, and FIG. 7B is a three-lane vehicle. It is explanatory drawing (2) which shows the example which vehicles AE drive | working the road. FIG. 8A is an explanatory diagram (1) showing an example in which vehicles A to C are traveling on a road having two lanes, and FIG. 8B is a diagram showing two lanes. It is explanatory drawing (2) which shows the example which vehicles AC drive on a certain road. FIG. 9 is an explanatory diagram showing an example in which vehicles A to G are traveling on a road having one lane.

  First, as illustrated in FIG. 7, a case will be described in which vehicles A to E are traveling on a road having three lanes. In this case, the communication wavelength of the vehicle A is green, the communication wavelength of the vehicle B is blue, the communication wavelength of the vehicle C is blue, the communication wavelength of the vehicle D is green, and the communication wavelength of the vehicle E is yellow. It is. When the vehicle C moves to the right and approaches the vehicles A, B, D, the vehicle C changes its communication wavelength from blue to yellow so that the communication wavelength is not the same as the communication wavelength assigned to the surrounding vehicles. change. Subsequently, similarly, the vehicle D changes its communication wavelength from green to red so that the communication wavelength is not the same as the communication wavelength assigned to the surrounding vehicle.

  Subsequently, when the vehicle E moves forward and approaches the vehicles C and D, the vehicle E changes its communication wavelength from yellow to blue so that the communication wavelength is not the same as the communication wavelength assigned to the surrounding vehicles. Is transmitted to the vehicles C and D. Then, the vehicle E changes its communication wavelength from yellow to blue.

  Next, as illustrated in FIG. 8, a case where the vehicles A to C are traveling on a road having two lanes will be described. In this case, the communication wavelength of the vehicle A is green, the communication wavelength of the vehicle B is blue, and the communication wavelength of the vehicle C is green. When the vehicle C moves forward and approaches the vehicles A and B, the vehicle C changes its communication wavelength from green to red so that the communication wavelength is not the same as the communication wavelength assigned to the surrounding vehicles. The effect is transmitted to vehicles A and B. Then, the vehicle C changes its communication wavelength from green to red.

Next, as illustrated in FIG. 9, a case where the vehicles A to G are traveling on a road having one lane number will be described. In this case, the communication wavelength of the vehicle A is green, the communication wavelength of the vehicle B is blue, the communication wavelength of the vehicle C is yellow, the communication wavelength of the vehicle D is red, and the communication wavelength of the vehicle E is blue. The communication wavelength of the vehicle F is green, and the communication wavelength of the vehicle G is yellow. When vehicle E moves forward and approaches vehicles C and D, vehicle E changes its communication wavelength to blue so that the communication wavelength is not the same as the communication wavelength assigned to the surrounding vehicles. It is transmitted to vehicles A and B. Then, the vehicle E changes its communication wavelength to blue.
[effect]
(1) Thus, according to the vehicle-to-vehicle communication device 1 of the first embodiment, the following effects are obtained. That is, the conventional travel control device has a problem that when there are a plurality of vehicles ahead, the laser light is easily blocked by the vehicles, and thus it is difficult to appropriately perform light communication between vehicles. Further, even when the light of the oncoming vehicle is received as noise, there is a problem in that it is difficult to appropriately perform communication using laser light between vehicles. On the other hand, according to the inter-vehicle communication device 1 of the first embodiment, based on the communication conditions set for each vehicle (that is, the position of the counterpart vehicle and the offset position information of the communication device), the communication device positions of the surrounding vehicles. Therefore, even when there are a plurality of vehicles ahead, communication can be performed appropriately between vehicles.

  (2) According to the inter-vehicle communication device 1 of the first embodiment, at least four types of communication wavelengths are set. This makes it possible to assign different communication wavelengths to the adjacent vehicle and the own vehicle.

  (3) Moreover, according to the vehicle-to-vehicle communication device 1 of the first embodiment, it is configured to communicate only with a preceding vehicle within a predetermined range from the own vehicle. As a result, only the vehicles existing within the detection range are targeted for communication, so that the number of vehicles communicating simultaneously can be limited, and the load on the communication control unit 26 of the inter-vehicle communication device 1 increases. Can be prevented.

  (4) Further, according to the inter-vehicle communication device 1 of the first embodiment, the communication control unit 26 refers to the limit distance determination table and widens the detection range when the traveling speed of the host vehicle increases. On the other hand, when the traveling speed of the host vehicle becomes small, the detection range is narrowed. Thus, it can be expected that the number of surrounding vehicles existing in the detection range is appropriately maintained.

  (5) Further, according to the inter-vehicle communication device 1 of the first embodiment, when the communication control unit 26 detects a “fluctuation state” in which the same surrounding vehicle enters or exits within the detection range. The surrounding vehicles are not subject to communication. As a result, even when the “staggered state” is detected, it is possible to prevent the processing related to the surrounding vehicle from being repeated, and as a result, the load on the communication control unit 26 of the inter-vehicle communication device 1 increases. Can be prevented.

  (6) According to the inter-vehicle communication device 1 of the first embodiment, if it is determined that the communication wavelength assigned to the own vehicle and the communication wavelength assigned to the surrounding vehicle are the same, Change the communication wavelength assigned to the vehicle so that it is not the same as the communication wavelength assigned to the vehicle, and update the stored content of the memory 22 to the communication wavelength assigned to the vehicle after the change, Information on the communication wavelength assigned to the vehicle after the change is transmitted to surrounding vehicles. As a result, the communication wavelength assigned to the host vehicle can be maintained at a communication wavelength different from the communication wavelengths assigned to the surrounding vehicles.

  (7) Moreover, according to the inter-vehicle communication apparatus 1 of the first embodiment, when the communication control unit 26 receives from the other inter-vehicle communication apparatus 1 that the communication wavelength assigned to the surrounding vehicle has been changed. In this case, the storage content of the memory 22 is updated to the communication wavelength assigned to the surrounding vehicle after the change. Thus, for example, even if the communication wavelength assigned to the vehicle traveling around the surrounding vehicle is changed, the communication wavelength assigned to the own vehicle is changed to the communication wavelength assigned to the surrounding vehicle. Can be maintained at a different communication wavelength.

  (8) Moreover, according to the inter-vehicle communication apparatus 1 of the first embodiment, each transmitter / receiver such as the front transmitter / receiver 14 is configured to be able to change the transmission direction of the electromagnetic wave to be transmitted in the vertical direction and the horizontal direction. The communication control unit 26 identifies the position of the transceiver included in the inter-vehicle communication device 1 that is the transmission source of the various information based on the various information received by each transceiver, and the vehicle that is the identified transmission source. Each transceiver is controlled to transmit electromagnetic waves toward the transceiver of the inter-vehicle communication device 1. In this case, the communication control unit 26 specifies the position of the transmitter / receiver with reference to the offset value included in various information.

  This produces the following effects. That is, as an example, since the height direction of a vehicle is different between a normal vehicle and a large vehicle, there is a case where the position of the communication device of the large vehicle viewed from the normal vehicle becomes a position to look up as the distance approaches. Therefore, it receives the installation position information of the communication device of the other vehicle, and performs communication aiming at the communication device of the other vehicle based on the data. In this case, the installation position of the communication device of the other vehicle is included in the communication data to the approaching vehicle. The position of the vehicle is the position of the center of gravity of the vehicle (this is not the position of the center of gravity but the center position of the tip), and the positions of a plurality of communication devices are represented by offset values. When the communication device position is set in this way, the communication device that transmits the vehicle can easily determine the position of the communication device of the other party by numerical calculation. Can be done.

[Other Embodiments]
As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment, It is possible to implement in various aspects. For example, even when the vehicle does not have an ignition key or the like like an electric vehicle, the communication process can be started by starting the vehicle starting device.

  (1) As illustrated in FIG. 10A, the inter-vehicle communication device 1 includes a rear transceiver 16 installed at the rear part of the vehicle, and a left transceiver 18 installed at the left front corner of the vehicle. It is good also as a structure provided with the transmitter / receiver 20 for right installed in the front left corner of a vehicle. In this example, the left transceiver 18 and the measurement radar are integrated, and the right transceiver 20 and the measurement radar are integrated.

It is a block diagram which shows the structure of a vehicle-to-vehicle communication apparatus. (A) is explanatory drawing explaining the allocation of a communication wavelength and a communication wavelength as an example of the difference of a wavelength, (b) is explanatory drawing which shows a communication wavelength. (A) is explanatory drawing (1) which shows the communication area of the measurement radar for the front of the inter-vehicle communication apparatus in the own vehicle, and the measurement radar for the back, (b) is the front of the inter-vehicle communication apparatus in the own vehicle and a surrounding vehicle. It is explanatory drawing which shows the communication area of the measurement radar for back and the measurement radar for back, (c) is explanatory drawing (2) which shows the communication area of the measurement radar for front of the inter-vehicle communication apparatus in the own vehicle, and the measurement radar for back. (D) is explanatory drawing (3) which shows the communication area of the measurement radar for the front of the inter-vehicle communication apparatus in the own vehicle, and the measurement radar for the back. It is explanatory drawing which shows a limiting distance determination table. It is a flowchart for demonstrating a communication wavelength change process. It is a flowchart for demonstrating a vehicle-to-vehicle communication process. (A) is explanatory drawing (1) which shows the example in which vehicles AE drive | working the road with three lanes, (b) is the vehicle AE using the road with three lanes. It is explanatory drawing (2) which shows the example which is drive | working. (A) is explanatory drawing (1) which shows the example which vehicles AC drive on the road where the number of lanes is 2 lanes, (b) is the road where vehicles A-C are 2 lanes. It is explanatory drawing (2) which shows the example which C is drive | working. It is explanatory drawing which shows the example which vehicles AG drive on the road whose number of lanes is 1 lane. It is explanatory drawing which shows the structure of a vehicle-to-vehicle communication apparatus. (A) is explanatory drawing which shows the structure of the transmitter / receiver 14 for front, (b) is explanatory drawing which shows allocation of a communication wavelength. It is explanatory drawing which shows the example which the vehicles 1-6 drive on the road whose number of lanes is 3 lanes. (A) is explanatory drawing (1) which shows the condition where the vehicle-to-vehicle communication apparatus is communicating with each other, (b) is explanatory drawing (2) which shows the condition where the vehicle-to-vehicle communication apparatus is communicating with each other. is there.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Inter-vehicle communication apparatus, 10 ... Front measurement radar, 12 ... Side measurement radar, 14 ... Front transmitter / receiver, 14a ... Transmitter, 14b ... Receiver, 14c ... Communication wavelength switcher, 16 ... Backward Transceiver, 18 ... transceiver for left, 20 ... transceiver for right, 22 ... memory, 24 ... external I / F, 26 ... communication control unit

Claims (8)

A vehicle-to-vehicle communication system configured by a plurality of vehicle-to-vehicle communication devices mounted on a vehicle and communicating with each other,
Each inter-vehicle communication device is
A communication wavelength storage means for storing a communication wavelength assigned to each vehicle;
And communication means for communicating with the other vehicle-to-vehicle communication device mounted around vehicles existing ambient,
Transmits the various information Previous SL controls the communication unit in the communication wavelength assigned to the vehicle communication wavelength storing means for storing other vehicle-to-vehicle communication device, around the vehicle by the communication wavelength storing means for storing and other communication control means for the respective species the same kind of information transmitted from the vehicle-to-vehicle communication device receives and controls the communication unit at assigned communication wavelength,
A communication wavelength identical judgment means for judging whether or not the communication wavelength assigned to the own vehicle and the communication wavelength assigned to the surrounding vehicle are the same with reference to the storage content stored in the communication wavelength storage means;
If the communication wavelength identification means determines that the communication wavelength assigned to the host vehicle and the communication wavelength assigned to the surrounding vehicle are the same, the type of the communication wavelength assigned to the surrounding vehicle The communication wavelength type assigned to the vehicle is changed so as not to be the same, and the stored content of the communication wavelength storage means is updated to the communication wavelength type assigned to the vehicle after the change. Memory control means,
The vehicle-to-vehicle communication system, wherein the communication control means of the inter-vehicle communication device controls the communication means to transmit information about the communication wavelength assigned to the vehicle after the change to the surrounding vehicle .   The inter-vehicle communication system according to claim 1,
  At least four types of wavelengths used for the communication are set.   In the inter-vehicle communication system according to any one of claims 1 to 2,
  The inter-vehicle communication device further includes:
  Vehicle speed detecting means for detecting the traveling speed of the vehicle on which the inter-vehicle communication device is mounted;
  Detection range setting means for setting a detection range for detecting surrounding vehicles traveling around the vehicle according to the traveling speed detected by the vehicle speed detecting means;
  Vehicle presence determination means for determining whether or not another vehicle exists within the detection range set by the detection range setting means;
  With
  The communication control means of the inter-vehicle communication device is mounted on the surrounding vehicle by regarding the vehicle as a surrounding vehicle when the vehicle presence determining means determines that another vehicle exists within the detection range. Communicate only with the inter-vehicle communication device
  A vehicle-to-vehicle communication system.   The inter-vehicle communication system according to claim 3,
  The detection range setting means of the inter-vehicle communication device widens the detection range when the traveling speed of the own vehicle detected by the vehicle speed detection means increases, while the traveling speed of the own vehicle decreases. The vehicle-to-vehicle communication system is characterized in that the detection range is narrowed in the case of occurrence.   In the inter-vehicle communication system according to claim 3 or claim 4,
  The inter-vehicle communication device further includes:
  Stirring determination means for determining whether or not a surrounding vehicle determined to be within the detection range by the vehicle presence determination means is in a wandering state,
  The communication control means of the vehicle-to-vehicle communication device does not change the communication wavelength with the vehicle-to-vehicle communication device mounted in the surrounding vehicle when it is determined that the wobble determination device is in a wobble state.
  A vehicle-to-vehicle communication system.   In the inter-vehicle communication system according to any one of claims 1 to 5,
  The inter-vehicle communication device further includes:
  When the communication means receives from the other inter-vehicle communication device that the communication wavelength assigned to the surrounding vehicle has been changed, the communication wavelength is changed to the communication wavelength assigned to the surrounding vehicle after the change. Provided with second storage control means for updating the storage contents of the storage means
  A vehicle-to-vehicle communication system.   The inter-vehicle communication system according to any one of claims 1 to 6,
  The communication means is configured to be able to change the transmission direction of electromagnetic waves to be transmitted,
  The communication control means specifies the position of the communication means included in the vehicle-to-vehicle communication device that is the transmission source of the various information based on the various information received by the communication means, and the vehicle-to-vehicle communication that is the specified transmission source. Controlling said communication means to transmit electromagnetic waves towards the communication means of the apparatus
  A vehicle-to-vehicle communication system.   A vehicle-to-vehicle communication device for use in a vehicle-to-vehicle communication system according to any one of claims 1 to 7, comprising the configuration described with respect to the vehicle-to-vehicle communication device according to any one of claims 1 to 7. A vehicle-to-vehicle communication device characterized by the above.