JP2015121967A - Vehicle communication device and communication method for vehicle communication device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique by which visible light communication between vehicles can be established on a road with poor visibility.SOLUTION: A vehicle communication device 1 comprises, as constitutions for transmitting information, a headlamp 3 installed on a vehicle 2 and a signal transmission device 10 which makes visible light V with a communication signal superimposed thereon to be emitted from the headlamp 3. The signal transmission device 10 executes signal superimposition processing of superimposing a communication signal on the visible light V emitted from the headlamp 3 when a road reflecting mirror 90 is within an arrival range of the visible light V emitted from the headlamp 3.

Description

  The present invention relates to a vehicle communication device for performing communication between vehicles, and a communication method for a vehicle communication device for performing communication between vehicles.

  As a vehicle communication apparatus as described above, one described in JP 2009-237944 A (Patent Document 1) is known. Patent Document 1 describes a configuration in which information is transmitted to another vehicle by modulating visible light emitted from an LED provided in the vehicle with a transmission signal. In addition, JP 2010-241311 A (Patent Document 2) is not communication between vehicles, but modulates visible light emitted from a headlight of a vehicle to provide a device outside the vehicle. A configuration for transmitting vehicle-specific identification information is described.

JP 2009-237944 A (paragraph 0030, etc.) JP 2010-241311 A (paragraphs 0025, 0034, etc.)

  By the way, in visible light communication in which communication is performed using visible light as a carrier wave, communication cannot be performed properly in a situation where light from a communication device on the transmission side is blocked. Therefore, when communicating between vehicles using visible light communication like the said patent document 1, there exists a possibility that it may become difficult to communicate appropriately on a road with bad visibility (for example, intersection with bad visibility). There is. However, Patent Documents 1 and 2 did not particularly recognize this point.

  Therefore, it is desired to realize a technology that makes it possible to establish visible light communication between vehicles on a road with poor visibility.

  A first characteristic configuration of a vehicle communication device for performing communication between vehicles according to the present invention is that a headlamp provided in a vehicle and visible light on which a communication signal is superimposed are emitted from the headlamp. And a signal transmission device that causes the visible light emitted from the headlight to be emitted when a road reflector is present within the reach of visible light emitted from the headlight. The point is to execute a signal superimposing process for superimposing the communication signal.

  Moreover, the 1st characteristic structure of the communication method of the vehicle communication apparatus which communicates between vehicles based on this invention is irradiated from the headlamp of a vehicle using the signal transmitter with which the said vehicle communication apparatus is provided. A signal superimposing step of superimposing a communication signal on visible light is provided, and the signal superimposing step is performed when a road reflector is present within the reachable range of visible light emitted from the headlamp.

  According to these characteristic configurations, without using a light source dedicated to visible light communication, the headlight provided in the vehicle is used as the light source of the carrier wave, and the visible light on which the communication signal is superimposed is communicated with other vehicles. Can be irradiated for. In addition, according to these characteristic configurations, the signal superimposing process (signal superimposing step) for superimposing the communication signal on the visible light emitted from the headlamp is within the reachable range of the visible light emitted from the headlamp. This is executed when there is a road reflector. Here, the road reflector is generally installed on a road with poor visibility, and is arranged so as to reflect a space that is a blind spot of a vehicle driver. Therefore, by performing signal superimposition processing when a road reflector exists within the visible light reachable range, the space that becomes the blind spot of the driver, that is, the space that cannot directly irradiate the visible light from the headlamp However, it is possible to irradiate visible light from the headlamp using reflection by the road reflector. As a result, it becomes possible to establish visible light communication between vehicles on a road with poor visibility.

  The second characteristic configuration of the vehicle communication device for performing communication between vehicles according to the present invention is to detect a light receiving device provided in the vehicle and a communication signal superimposed on visible light received by the light receiving device. A signal receiving device configured to receive the reflected light emitted from a headlamp of another vehicle and reflected by a road reflector, and the signal receiving device is superimposed on the reflected light. In other words, the detected communication signal is detected.

  According to the present invention, a second characteristic configuration of a communication method for a vehicle communication device that performs communication between vehicles is received by a light receiving device provided in the vehicle using a signal reception device provided in the vehicle communication device. A signal detection step for detecting a communication signal superimposed on the visible light, and the signal detection when the light receiving device receives reflected light that is irradiated from a headlamp of another vehicle and reflected by a road reflector. The point is to execute the process.

  According to these characteristic configurations, information transmitted from a vehicle at a position where the visible light from the headlight cannot be directly received can be received by receiving the reflected light of the visible light from the road reflector. . Since the road reflector is generally set on a road with poor visibility, according to these characteristic configurations, it is possible to establish visible light communication between vehicles on a road with poor visibility.

1 is a block diagram showing a schematic configuration of a vehicle communication device according to an embodiment of the present invention. It is a figure which shows the example of a setting of the irradiation range in the condition which approachs an intersection. It is explanatory drawing of the communication between vehicles in the condition shown in FIG. It is a figure which shows another example of the setting of the irradiation range in the condition which approachs an intersection. It is explanatory drawing of the communication between vehicles in the condition shown in FIG. It is explanatory drawing of the communication between vehicles in case an intersection is a T-shaped road. It is explanatory drawing of the communication between vehicles on a curve road. It is a flowchart which shows an example of the procedure of the signal transmission process which concerns on embodiment of this invention. It is a flowchart which shows an example of the procedure of the signal reception process which concerns on embodiment of this invention.

  Embodiments of the present invention will be described with reference to the drawings. Here, a case where the vehicle communication device according to the present invention is provided in an automobile (including a four-wheel automobile and a two-wheel automobile) as an example of the vehicle will be described as an example. In the present specification, that the device is provided (or provided) in the vehicle 2 is provided (or provided) in the vehicle 2 at least when the device is used (when used for communication between vehicles). This means that not only the case where the device is fixedly mounted on the vehicle 2 but also the case where the device is brought into the vehicle 2 only during use. Moreover, in this embodiment, communication between vehicles provided with the vehicle communication device 1 is two-way communication. Each vehicle 2 transmits information to another vehicle, and the information is transmitted to other vehicles. It can be any of the receiving side vehicle 2b that receives from the vehicle. In FIG. 1 and FIG. 3, etc., the sign “2a” is attached to the vehicle 2 that is transmitting information to the other vehicle in the assumed situation, and the sign is assigned to the vehicle 2 that is receiving information from the other vehicle in the situation. “2b” is attached.

1. Overall Configuration of Vehicle Communication Device The vehicle communication device 1 is a communication device for performing communication between vehicles. The vehicle communication device 1 is a device that performs communication using light in the visible light region as a carrier wave, and specifically, visible light (illumination light) emitted from the headlamp 3 of the vehicle 2. Communication is performed using the carrier wave. As shown in FIG. 1, the vehicle communication device 1 includes a headlamp 3 and a signal transmission device 10 as a configuration for transmitting information. In addition, the vehicle communication device 1 includes a light receiving device 4 and a signal receiving device 20 as a configuration for receiving information. In the present embodiment, each vehicle 2 is provided with a vehicle communication device 1 having both a configuration for transmitting information and a configuration for receiving information. In FIG. 1, in order to facilitate understanding of the invention, a configuration for transmitting information is described inside the transmission-side vehicle 2a, and a configuration for receiving information is described inside the reception-side vehicle 2b. . The configuration of the signal transmission device 10 will be described in detail in the section “2. Configuration of the signal transmission device” later, and the configuration of the signal reception device 20 will be described in detail in the section “3. Configuration of the signal reception device” later. Explained.

  The headlamp 3 is a lighting device provided in the vehicle 2. The headlamp 3 is configured to irradiate visible light V in front of the vehicle 2. The headlamp 3 is provided in the front part of the vehicle 2, for example. Visibility of the driver of the vehicle 2 is ensured by the visible light V emitted by the headlamp 3, and visibility of the vehicle 2 provided with the headlamp 3 is ensured. In the present specification, the “headlight” includes a light source for irradiating a so-called low beam (passing headlight) and a light source for irradiating a so-called high beam (traveling headlamp). The concept is not limited to a headlamp, and includes any lighting device that irradiates visible light V in front of the vehicle 2. For example, a front fog lamp (front fog lamp) used when the field of view is limited by fog or the like is also included in the headlamp.

  Here, as shown in FIG. 2, a range in which the intensity of the visible light V emitted from the headlamp 3 is equal to or higher than a predetermined first set intensity is defined as an irradiation range B. Strictly speaking, the irradiation range B is a three-dimensional region, but as shown in FIG. 2, the irradiation range B is represented by a two-dimensional region in a virtual plane orthogonal to the irradiation direction of the headlamp 3 (the vehicle longitudinal direction). be able to. The irradiation range B on the virtual plane is represented by a two-dimensional region surrounded by a light / dark boundary line (cut-off line). The first set intensity can recognize, for example, an object that exists at a predetermined distance from the vehicle 2 on the irradiation direction side of the headlamp 3 (front side of the vehicle) by a human visual sense. Set to strength.

  In the present embodiment, the headlamp 3 is configured to be able to change the irradiation range B. For example, the irradiation range is controlled by controlling the optical axis of the light source included in the headlamp 3, or by controlling the irradiation area of the light from the light source using a light modulation element, a light shielding member (shade, shutter, etc.), etc. It can be set as the structure by which B is changed. In addition, when the headlamp 3 includes a plurality of light sources, in addition to the above-described controls, the following configuration may be employed. That is, it can be set as the structure provided with the several light source from which an irradiation area mutually differs, and can be set as the structure by which the irradiation range B is changed by controlling the lighting state of each of the said several light source. In this case, the irradiation range B is configured by the sum of the irradiation regions (regions where the intensity of the visible light V is equal to or higher than the first set intensity) for each of the light sources that are turned on.

  The visible light V emitted from the headlamp 3 is modulated by the signal transmission device 10 by superimposing a communication signal. Therefore, it is preferable to use a light source having high response to modulation, such as an LED (Light Emitting Diode) or a xenon lamp, as the light source of the headlamp 3. As described above, when the headlamp 3 includes a plurality of light sources having different irradiation regions, all the light sources may be configured as light sources subject to modulation control by the signal transmission device 10. A plurality of partial light sources may be configured to be light sources to be modulated by the signal transmission device 10. In the latter configuration, the irradiation range B is configured by an irradiation region by the partial light source to be subjected to modulation control.

  The light receiving device 4 is a light detection device provided in the vehicle 2. The light receiving device 4 is provided, for example, at the front portion of the vehicle 2. Then, as will be described later, the signal receiving device 20 detects a communication signal superimposed on the visible light V received by the light receiving device 4. The light receiving device 4 is configured to receive reflected light that is irradiated from the headlamp 3 of another vehicle and reflected by the road reflecting mirror 90. In other words, the light receiving device 4 is configured to be able to adjust the optical axis and the light receiving range so as to receive the reflected light from the road reflecting mirror 90 when the road reflecting mirror 90 exists in front of the vehicle 2. Has been. The road reflecting mirror 90 is a reflecting mirror (curved mirror) installed at an intersection 80, a curved road 83 or the like in order to check other vehicles (see FIGS. 3 and 7). The road reflecting mirror 90 has a mirror surface formed in a convex spherical shape, for example.

  The light receiving device 4 includes a sensor having sensitivity in the visible light region. This sensor is, for example, a photodiode or a phototransistor. In the present embodiment, the light receiving device 4 is configured by a camera 6 (vehicle camera) having an image sensor in which sensors are two-dimensionally arranged. The camera 6 is provided in the vehicle 2 so as to photograph at least a scene in front of the vehicle. The camera 6 is provided, for example, on the indoor side of the windshield. In FIG. 1, the light receiving device 4 is described as a device separate from the camera 6 for easy understanding of the invention. However, as described above, in the present embodiment, the camera 6 is also used as the light receiving device 4. ing.

2. Configuration of Signal Transmitting Device The signal transmitting device 10 is a device that irradiates the headlamp 3 with visible light V on which a communication signal is superimposed. The signal transmission device 10 includes an arithmetic processing device such as one or a plurality of CPUs (Central Processing Units) as a core member, and a storage device (for example, a RAM (Random Access Memory) or a ROM (e.g. Read Only Memory)). A signal transmission program executed by the arithmetic processing device of the signal transmission device 10, specifically, a function of irradiating the visible light V on which the communication signal is superimposed from the headlamp 3 is realized in the arithmetic processing device of the signal transmission device 10. The program for storing is stored in a storage device of the signal transmission device 10 or stored in a storage device from which the signal transmission device 10 can refer to data. In the present invention, such a program and a storage medium (for example, an optical disk, a flash memory, etc.) in which such a program is stored can also be targeted.

  The signal transmission device 10 is configured to be able to acquire information on the road reflector 90 existing within the reachable range of the visible light V with reference to the database 30 that stores information on the road reflector 90 installed in various places. Yes. The reachable range of the visible light V will be described later. Although FIG. 1 illustrates the case where the database 30 is provided in the vehicle, the database 30 may be provided in an external device (such as a server) that can communicate with the device provided in the vehicle 2. . The database 30 also stores map information. In the present embodiment, information on priority types is also stored. The priority type is a classification of a priority order related to traffic between a plurality of approach roads entering the same intersection 80. Information on the road reflector 90 is stored in the database 30 in association with information on a point (for example, an intersection 80) where the road reflector 90 is installed. In the present embodiment, the signal transmission device 10 can also reach the reach of the visible light V by the image recognition processing of the road reflector 90 included in the image captured by the camera 6 in front of the host vehicle (transmission side vehicle 2a). The information of the road reflecting mirror 90 existing inside can be acquired.

  The signal transmission device 10 superimposes a communication signal on the visible light V emitted from the headlamp 3 when the road reflector 90 is present within the reach of the visible light V emitted from the headlamp 3. Execute superimposition processing. The signal superimposing process is executed by the signal superimposing device 11 included in the signal transmitting device 10. By this signal superimposing process, the visible light V for illumination is modulated, and a communication signal is superimposed on the visible light V. At this time, by modulating at a frequency that cannot be recognized by human vision due to the afterimage phenomenon (for example, blinking in a short cycle), while ensuring the driver's visibility and the visibility of the vehicle 2 appropriately, Information can be transmitted using the headlamp 3.

  The signal superimposing device 11 performs a signal superimposing process by controlling a drive circuit (not shown) that drives the headlamp 3. Specifically, the signal superimposing device 11 superimposes the communication signal on the visible light V emitted from the headlamp 3 by superimposing the communication signal on the driving current or the driving voltage of the headlamp 3, and Modulate light V. At this time, various modulation schemes can be applied. For example, amplitude modulation, frequency modulation, pulse width modulation, pulse code modulation, and the like can be applied. The communication signal superimposed on the visible light V is a signal representing the information on the transmission-side vehicle 2a. Here, the information on the transmission side vehicle 2a is information to be notified to the reception side vehicle 2b. For example, the distance from the transmission side vehicle 2a to the point where the road reflector 90 is installed, the point on the transmission side vehicle 2a. The estimated arrival time, the vehicle speed of the transmitting vehicle 2a, and the like.

  In the present embodiment, the signal transmission device 10 includes an irradiation range changing device 12 in addition to the signal superimposing device 11. The irradiation range changing device 12 is a device that changes the irradiation range B. The irradiation range changing device 12 is configured to be able to control a configuration (mechanism or device) for changing the irradiation range B. As described above, the configuration for changing the irradiation range B is, for example, a configuration for controlling the optical axis of the light source of the headlamp 3, and an irradiation region of light from the light source using a light modulation element, a light shielding member, or the like. Or a configuration for controlling the lighting state of each of the plurality of light sources when the headlamp 3 includes a plurality of light sources.

  As illustrated in FIG. 2, the irradiation range changing device 12 sets the irradiation range B so as to include the road reflector 90 during the execution of the signal superimposing process. Specifically, the irradiation range B is set so as to include the road reflector 90 existing within the reachable range of the visible light V. Further, the irradiation range B is set so as to include a part or the whole of the mirror surface of the road reflecting mirror 90. In the present embodiment, the irradiation range B is set so as to include the entire mirror surface of the road reflecting mirror 90. . By setting the irradiation range B so as to include the road reflector 90 in this way, the visible light V on which the communication signal is superimposed is transmitted by the road reflector 90 during execution of the signal superimposition process, as shown in FIG. It can be reflected and supplied to the other vehicle (receiving vehicle 2b). The irradiation range changing device 12 may be configured to reset the irradiation range B to different ranges as needed according to the distance from the vehicle 2 (transmission-side vehicle 2a) to the road reflector 90. FIG. 2 shows an example in which the irradiation range B is set so as to include many road surfaces in front of the vehicle, assuming that the vehicle travels at night. For example, when the headlamp 3 includes a light source for irradiating a high beam, the irradiation range B can be set so that the road reflector 90 is included in the high beam irradiation region. In this case, only the latter light source of the light source for irradiating the low beam and the light source for irradiating the high beam can be configured to be subject to modulation control by the signal transmission device 10. At this time, the irradiation range B is configured by an irradiation region by a light source for irradiating a high beam.

  In the present embodiment, when there are a plurality of road reflectors 90 within the reachable range of the visible light V, the irradiation range changing device 12 basically includes all of the plurality of road reflectors 90. An irradiation range B is set. For example, in the situation shown in FIGS. 2 and 3, the intersection 80 in front of the transmission-side vehicle 2 a is a crossroad 81. At the intersection 80, a road reflecting mirror 90 (the left road reflecting mirror 90 in FIG. 2) for reflecting the right approach road entering the intersection 80 from the right side with respect to the transmission side vehicle 2a, and the transmission side vehicle 2a. On the other hand, a road reflecting mirror 90 (the right road reflecting mirror 90 in FIG. 2) for reflecting the left approach road entering the intersection 80 from the left side is installed. Note that “right side” means the right side in the traveling direction of the transmission-side vehicle 2a, and “left side” means the left side in the traveling direction of the transmission-side vehicle 2a. The same applies hereinafter. In this case, as shown in FIG. 2, the irradiation range B is basically set so as to include both of the two road reflectors 90. Therefore, as shown in FIG. 3, it is possible to supply visible light V on which a communication signal is superimposed to another vehicle entering the intersection 80 from the right approach road (see the solid arrow representing the visible light V). ), It is possible to supply the visible light V on which the communication signal is superimposed to other vehicles entering the intersection 80 from the left approach road (see the broken line arrow indicating the visible light V). In other words, it is possible to transmit information from the transmission-side vehicle 2a to the vehicle 2 entering the intersection 80 from any of the right approach road and the left approach road.

  As shown in FIG. 4, in the present embodiment, the irradiation range changing device 12 performs the signal superimposing process when the oncoming vehicle 2c exists in the irradiation range B set to include the road reflector 90 during execution of the signal superimposing process. Is configured to set the irradiation range B so as not to include the oncoming vehicle 2c. Thereby, it is possible to set the irradiation range B so that the glare given to the driver of the oncoming vehicle 2c is suppressed. In addition, the following two cases are included in “when the oncoming vehicle 2c exists within the irradiation range B set to include the road reflector 90”. The first is a case where the oncoming vehicle 2c already exists within the scheduled setting range when the irradiation range B is set. In this case, the irradiation range B that does not include the oncoming vehicle 2c is set from the beginning. The second is a case where when the irradiation range B is set, the oncoming vehicle 2c does not exist within the scheduled setting range, and then the oncoming vehicle 2c included in the set irradiation range B appears. In this case, the irradiation range B is reset so as not to include the oncoming vehicle 2c. Note that the oncoming vehicle 2c as a target here is an oncoming vehicle that exists within the reach of the visible light V.

  FIG. 4 shows a situation where the oncoming vehicle 2c exists at the same intersection 80 as in FIG. In this case, since the oncoming vehicle 2c is included in the irradiation range B when the irradiation range B is set as shown in FIG. 2, the irradiation range B is set so as not to include the oncoming vehicle 2c as shown in FIG. The In the example shown in FIG. 4, of the two road reflectors 90 that are separately arranged on the left and right sides with respect to the center of the intersection 80, the opposite side to the oncoming vehicle 2 c in the left-right direction with respect to the center of the intersection 80 ( The irradiation range B is set so as to include only the road reflector 90 on the left side in this example. That is, in the example shown in FIG. 4, the irradiation range B is set so as not to include the road reflector 90 on the oncoming vehicle 2c side (right side in this example) in the left-right direction with respect to the center of the intersection 80. In this case, as shown in FIG. 5, the visible light V on which the communication signal is superimposed is supplied to other vehicles entering the intersection 80 from the right approach road, as in the examples shown in FIGS. (See solid arrows representing visible light V). That is, it becomes possible to transmit information from the transmission-side vehicle 2a to the vehicle 2 entering the intersection 80 from the right approach road.

  On the other hand, the visible light V on which the communication signal is superimposed cannot be directly supplied to other vehicles entering the intersection 80 from the left approach road. However, part of the visible light V emitted from the headlamp 3 becomes leaked light outside the irradiation range B. Therefore, depending on the intensity of the visible light V emitted from the headlamp 3 and the optical path length from the transmission-side vehicle 2a to the other vehicle, the light is reflected by the road reflector 90 outside the irradiation range B and supplied to the other vehicle. The intensity of the leaked light can be set to such a magnitude that the signal receiving device 20 of the other vehicle can detect the communication signal. In this case, similar to the example shown in FIG. 3, in the example shown in FIG. 5, the transmission is made to the vehicle 2 entering the intersection 80 from any of the right approach road and the left approach road. Information can be transmitted from the side vehicle 2a. Further, in this case, the visible light V on which the communication signal is superimposed is emitted from the headlamp 3 of the vehicle 2 entering the intersection 80 from the left approach road, and the irradiation range B of the visible light V is shown in FIG. By setting so as to include the right side road reflector 90, information can be transmitted from the vehicle 2 entering the intersection 80 from the left approach road to the transmitting vehicle 2a in FIG.

  4 illustrates the case where the irradiation range B is set so as not to include the road reflector 90 on the oncoming vehicle 2c side (right side in this example) in the left-right direction with respect to the center of the intersection 80. Even when the oncoming vehicle 2c exists, the irradiation range B may be set so as to include both of the two road reflecting mirrors 90 arranged separately on the left and right sides with respect to the center of the intersection 80. In this case, for example, on the virtual plane orthogonal to the irradiation direction of the headlamp 3, the irradiation range B is configured by a U-shaped region.

  With reference to FIG. 8, the procedure of the signal transmission process which the signal transmission apparatus 10 which concerns on this embodiment performs is demonstrated. This signal transmission processing is executed by the arithmetic processing device of the signal transmission device 10 performing an operation according to a program stored in the storage device.

  As illustrated in FIG. 8, when it is determined that the road reflector 90 exists within the reachable range of the visible light V (step # 01: Yes), the processes of steps # 02 to # 04 are performed in order. Here, the reachable range of the visible light V is a range in which the visible light V having a predetermined second set intensity or higher can be irradiated from the headlamp 3, and the vehicle 2 (transmission side vehicle 2a) is irradiated. On the other hand, it is a range set to extend forward. The second set intensity is set based on, for example, the detection limit of the light receiving device 4. Specifically, the visible light is reflected so that the intensity of the reflected light from the road reflector 90 existing in the reachable range of the visible light V when reaching the light receiving device 4 is equal to or higher than the detection limit of the light receiving device 4. The reach range of V is set. The detection limit is a detection limit under a condition that a communication signal superimposed on the visible light V can be detected. For the sake of simplicity, the intensity of the visible light V reaching the light receiving device 4 is set to an intensity in a situation where the distance from the road reflector 90 to the light receiving device 4 is equal to the distance from the headlamp 3 to the road reflector 90. Can do. When considered with such a simplified model, for example, when visible light V having a detection limit intensity is detected in the light receiving device 4, the light passes through the road reflector 90 from the headlamp 3 to the light receiving device 4. The half of the length of the optical path to be made can be the size of the reachable range of the visible light V in the irradiation direction of the headlamp 3 (vehicle longitudinal direction). At this time, when the road reflector 90 is disposed at the boundary portion on the vehicle front side in the reachable range of the visible light V, the intensity of the visible light V reaching the light receiving device 4 becomes equal to the detection limit of the light receiving device 4. . In addition, you may set the 1st setting intensity | strength mentioned above regarding the irradiation range B to the same value as a 2nd setting intensity | strength.

  The distance from the vehicle 2 to the road reflector 90 used in the process of step # 01 is stored in the database 30 and the current position of the vehicle 2 obtained by calculation based on information acquired from the position information detection device 5, for example. It can be set as the structure acquired based on the installation position of the road reflector 90. FIG. Alternatively, a configuration in which the distance from the vehicle 2 to the road reflector 90 is acquired based on the size of the road reflector 90 recognized by the image recognition process on the captured image of the camera 6, or a vehicle using these two methods in combination. The distance from 2 to the road reflector 90 may be acquired. Then, when the acquired distance from the vehicle 2 to the road reflector 90 does not exceed the size of the visible light V reachable range (the size in the vehicle front-rear direction), the road reflection is within the visible light V reachable range. It is determined that the mirror 90 exists (step # 01: Yes). The position information detection device 5 includes various devices for detecting position information, such as a GPS (Global Positioning System) receiver, a distance sensor, and an orientation sensor.

  If it is determined that the road reflector 90 is present within the reachable range of the visible light V (step # 01: Yes), the signal transmission device 10 executes an oncoming vehicle detection process (step # 02). In the oncoming vehicle detection process, for example, based on the image recognition process of the vehicle 2 included in the photographed image of the camera 6 or the presence or absence of detection by the camera 6 or other detector of the irradiation light from the headlamp 3 of another vehicle. Thus, the presence or absence of the oncoming vehicle 2c within the reachable range of the visible light V is detected.

  Based on the result of the oncoming vehicle detection process in step # 02, the visible light V irradiated from the headlamp 3 so that the irradiation range changing device 12 includes the road reflector 90 within the visible light V reachable range. Is set (step # 03). At this time, when the presence of the oncoming vehicle 2c is detected by the process of step # 02, the irradiation range B is set so as not to include the oncoming vehicle 2c. Further, when setting the irradiation range B, information on the height or elevation angle of the road reflector 90 (elevation angle with respect to the horizontal plane passing through the vehicle 2) is referred to the database 30 or image recognition processing for the image taken by the camera 6 is performed. Obtained by It is good also as a structure where the information of the feature-value (for example, the curvature of a mirror surface etc.) of the road reflector 90 is also acquired. And the signal superimposition apparatus 11 performs the signal superimposition process which superimposes a communication signal on the visible light V irradiated from the headlamp 3 of the vehicle 2 (step # 04). The process of step # 04 corresponds to the “signal superimposing process” in the present invention, and this signal superimposing process is performed when the road reflector 90 exists within the reachable range of the visible light V emitted from the headlamp 3. Executed.

  In a situation where the vehicle 2 enters the intersection 80, the approach road on which the vehicle 2 travels has priority over the intersection approach road that intersects the approach road (excluding the approach road facing the approach road). When the road is a road, signal transmission processing (signal superimposition processing) by the signal transmission device 10 is executed, and when the approach road on which the vehicle 2 travels is not a priority road for the intersection approach road, signal transmission by the signal transmission device 10 A configuration in which processing is not executed may be employed.

  Although detailed description is omitted, when the intersection 80 is a T-shaped road 82 as shown in FIG. 6 or when the road reflector 90 is provided on the curved road 83 instead of the intersection 80 as shown in FIG. Similarly, the signal transmission processing by the signal transmission device 10 described above can be executed.

3. Configuration of Signal Reception Device The signal reception device 20 is a device that detects a communication signal superimposed on visible light received by the light receiving device 4. Similarly to the signal transmission device 10, the signal reception device 20 includes an arithmetic processing device such as one or a plurality of CPUs as a core member, and also includes a storage device that can be referred to by the arithmetic processing device. Note that a CPU, a storage device, or the like may be shared by the signal transmission device 10 and the signal reception device 20. A signal reception program executed by the arithmetic processing device of the signal receiving device 20, specifically, a function of detecting a communication signal superimposed on visible light received by the light receiving device 4 is realized in the arithmetic processing device of the signal receiving device 20. The program for storing is stored in a storage device of the signal reception device 20 or stored in a storage device from which the signal reception device 20 can refer to data. In the present invention, such a program and a storage medium (for example, an optical disk, a flash memory, etc.) in which such a program is stored can also be targeted.

  The signal receiving device 20 is configured to be able to acquire information on the road reflector 90 with reference to the database 30. Further, in the present embodiment, the signal receiving device 20 also performs the information of the road reflector 90 by the image recognition process of the road reflector 90 included in the image taken by the camera 6 in front of the host vehicle (receiving vehicle 2b). Is configured to be obtainable. And the signal receiver 20 is comprised so that the communication signal superimposed on reflected light may be detected based on the information of the acquired road reflector 90. FIG. Here, the reflected light is reflected light that is irradiated from the headlamp 3 of another vehicle and reflected by the road reflecting mirror 90, and is simply referred to as “reflected light” hereinafter.

  The signal receiving device 20 executes a communication signal detection process when the light receiving device 4 receives reflected light. The communication signal detection process is executed by the communication signal detection device 21 included in the signal reception device 20. In the communication signal detection process, the visible light received by the light receiving device 4 is demodulated, and the communication signal superimposed on the visible light is read. At this time, the light receiving device 4 converts the received visible light V into an electric signal and outputs the electric signal, and the communication signal detecting device 21 detects the communication signal from the electric signal. In the present embodiment, as described above, the light receiving device 4 is the camera 6 having an image sensor. Therefore, the communication signal detection device 21 acquires an image signal of a pixel corresponding to the road reflector 90 from the image signal (electric signal) acquired by the image sensor, and detects the communication signal from the image signal. . And in this embodiment, the signal receiver 20 notifies the passenger | crew of the receiving side vehicle 2b the information based on the received communication signal. The content of the notified information is, for example, the content for notifying the presence of another vehicle and calling attention. The information notification method includes, for example, display of an image by a display device (not shown), output of sound by a speaker (not shown), and application of vibration to an occupant by a vibration device (not shown). The In addition, it is good also as a structure which controls the speed etc. of the receiving side vehicle 2b based on the communication signal which the signal receiver 20 received.

  With reference to FIG. 9, the procedure of the signal reception process which the signal receiver 20 which concerns on this embodiment performs is demonstrated. This signal receiving process is executed by the arithmetic processing unit of the signal receiving device 20 performing an operation according to a program stored in the storage device.

  As shown in FIG. 9, when it is determined that the road reflector 90 is present within the light receiving range of the light receiving device 4 (step # 11: Yes), the signal receiving device 20 executes reflected light detection processing (step #). 12). Here, the light receiving range of the light receiving device 4 is a range in which the light receiving device 4 can receive reflected light, and is a range set to extend forward with respect to the vehicle 2 (receiving side vehicle 2b). is there. The size of the light receiving range is set based on the detection limit of the light receiving device 4. It is also possible to set the size of the light receiving range to the same size as the visible light V reachable range described above. When the distance from the vehicle 2 to the road reflector 90 does not exceed the size of the light receiving range of the light receiving device 4 (size in the vehicle front-rear direction), the road reflector 90 is within the light receiving range of the light receiving device 4. It is determined that it exists (step # 11: Yes). The distance from the vehicle 2 to the road reflector 90 used in the process of step # 11 is the same as that of step # 01 of FIG.

  In the reflected light detection process of step # 12, the height or elevation information of the road reflector 90 is acquired by referring to the database 30 or the image recognition process for the captured image of the camera 6 as necessary. The optical axis and the light receiving range of the light receiving device 4 are adjusted so that the mirror 90 is included in the light receiving range of the light receiving device 4. At this time, it is also possible to obtain a feature amount (for example, the curvature of a mirror surface) of the road reflecting mirror 90 together. And when reflected light is detected by the reflected light detection process of step # 12 (step # 13: Yes), the communication signal detection apparatus 21 is superimposed on the visible light V (reflected light) received by the light receiving device 4. The communication signal detection process for detecting the transmitted communication signal is executed (step # 14). The step # 14 corresponds to the “signal detection step” in the present invention, and this signal detection step is reflected from the headlamp 3 of the other vehicle (transmission side vehicle 2a) and reflected by the road reflector 90. Performed when receiving light.

  In a situation where the vehicle 2 enters the intersection 80, the approach road on which the vehicle 2 travels has priority over the intersection approach road that intersects the approach road (excluding the approach road facing the approach road). A configuration in which signal reception processing by the signal reception device 20 is executed when the road is not a road, and signal reception processing by the signal reception device 20 is not executed when the approach road on which the vehicle 2 travels is a priority road with respect to the intersection approach road It can also be.

4). Outline of Embodiment of Present Invention The vehicle communication device (1) for performing communication between vehicles in the embodiment of the present invention described above has at least the following configuration as a configuration for transmitting information. Prepare.

  That is, a vehicle communication device (1) for performing communication between vehicles has a headlamp (3) provided in the vehicle (2) and a visible light on which a communication signal is superimposed. ), And the signal transmission device (10) has a road reflector (90) within the reach of visible light emitted from the headlamp (3). When doing, the signal superimposition process which superimposes the said communication signal on the visible light irradiated from the said headlamp (3) is performed.

  According to this configuration, without providing a light source dedicated to visible light communication, the headlight provided in the vehicle is used as a light source for the carrier wave, and the visible light on which the communication signal is superimposed is used for communication with other vehicles. Can be irradiated. In addition, according to this configuration, the signal superimposing process for superimposing the communication signal on the visible light emitted from the headlamp has a road reflector within the reach of the visible light emitted from the headlamp. If executed. Here, the road reflector is generally installed on a road with poor visibility, and is arranged so as to reflect a space that is a blind spot of a vehicle driver. Therefore, by performing signal superimposition processing when a road reflector exists within the visible light reachable range, the space that becomes the blind spot of the driver, that is, the space that cannot directly irradiate the visible light from the headlamp However, it is possible to irradiate visible light from the headlamp using reflection by the road reflector. As a result, it becomes possible to establish visible light communication between vehicles on a road with poor visibility.

  Moreover, in the vehicle communication device (1) according to the embodiment of the present invention, the signal transmission device (10) is such that the intensity of visible light emitted from the headlamp (3) is equal to or higher than a predetermined intensity. An irradiation range changing device (12) for changing the irradiation range (B) is provided, and the irradiation range changing device (12) includes the road reflector (90) during execution of the signal superimposing process. It is preferable that the range (B) is set.

  According to this configuration, visible light having an intensity required for visible light communication can be reliably irradiated onto the road reflector, so that visible light communication between vehicles on a road with poor visibility is established. It becomes easy.

  In the vehicle communication device (1) according to the embodiment of the present invention, the irradiation range changing device (12) is set to include the road reflector (90) during the execution of the signal superimposing process. When the oncoming vehicle (2c) exists in the irradiation range (B), it is preferable to set the irradiation range (B) so that the oncoming vehicle (2c) is not included.

  According to this configuration, it is possible to irradiate the road reflector with visible light having an intensity necessary for visible light communication while suppressing glare given to the driver of the oncoming vehicle. Therefore, it is possible to avoid the use of visible light communication between vehicles being restricted by the presence of oncoming vehicles.

  Further, in the vehicle communication device (1) according to the embodiment of the present invention, the signal transmission device (10) is obtained by referring to the database (30) storing information of the road reflectors (90) installed in various places. Alternatively, it is preferable that information of the road reflector (90) existing within the reachable range is acquired by image recognition processing of the road reflector (90) included in the image obtained by photographing the front of the host vehicle.

  According to this configuration, it is possible to appropriately acquire information on the road reflector, such as the installation position and the installation height, which is necessary when the road reflector is appropriately irradiated with visible light from the headlamp. it can. And when acquiring the information of a road reflector by referring to a database, the information of a road reflector can be acquired reliably. In addition, when acquiring the information of the road reflector by the image recognition process for the captured image in front of the host vehicle, the information of the road reflector including the relative relationship with the position of the host vehicle that can be changed every moment, Can be acquired.

  In the embodiment of the present invention, a vehicle communication device (1) for performing communication between vehicles includes at least the following configuration as a configuration for receiving information.

  That is, the vehicle communication device (1) for performing communication between vehicles includes a light receiving device (4) provided in the vehicle (2) and a communication superimposed on visible light received by the light receiving device (4). A signal receiving device (20) for detecting a signal, wherein the light receiving device (4) receives reflected light that is irradiated from a headlamp (3) of another vehicle and reflected by a road reflector (90). The signal receiving device (20) detects the communication signal superimposed on the reflected light.

  According to this structure, the information transmitted from the vehicle of the position which cannot receive the visible light from a headlamp directly can be detected by receiving the reflected light of the said visible light by the road reflector. Since the road reflector is generally set on a road with poor visibility, this configuration makes it possible to establish visible light communication between vehicles on a road with poor visibility.

  Further, in the vehicle communication device (1) according to the embodiment of the present invention, the signal receiving device (20) is obtained by referring to a database (30) storing information of road reflectors (90) installed in various places. Alternatively, the information of the road reflector (90) is acquired by the image recognition process of the road reflector (90) included in the image taken in front of the host vehicle, and is superimposed on the reflected light based on the acquired information. It is preferable that the communication signal is detected.

  According to this configuration, information on the road reflector, such as the installation position and the installation height, which is necessary when appropriately receiving the reflected light irradiated from the headlamps of other vehicles and reflected by the road reflector, Can be obtained. And when acquiring the information of a road reflector by referring to a database, the information of a road reflector can be acquired reliably. In addition, when acquiring the information of the road reflector by the image recognition process for the captured image in front of the host vehicle, the information of the road reflector including the relative relationship with the position of the host vehicle that can be changed every moment, Can be acquired.

5. Other Embodiments Finally, other embodiments according to the present invention will be described. Note that the configurations disclosed in the following embodiments can be applied in combination with the configurations disclosed in other embodiments as long as no contradiction arises.

(1) In the above embodiment, whether or not the road reflector 90 exists within the reachable range of the visible light V is determined based on whether the distance from the vehicle 2 to the road reflector 90 is the size of the reachable range of the visible light V. An example of a configuration that is determined based on whether or not is exceeded has been described. However, the embodiment of the present invention is not limited to this. For example, when the first set distance that is smaller than the size of the reachable range of the visible light V is used and the distance from the vehicle 2 to the road reflector 90 is equal to or less than the first set distance, the visible light V is within the reachable range. It can also be set as the structure determined with the road reflector 90 existing. Similarly, when a second set distance smaller than the size of the light receiving range of the light receiving device 4 is used and the distance from the vehicle 2 to the road reflector 90 is equal to or less than the second set distance, the light receiving range of the light receiving device 4 It can be configured that it is determined that the road reflector 90 exists. In this case, the first set distance and the second set distance can be set to the same distance.

(2) In the above embodiment, the case where the light receiving device 4 is configured by the camera 6 has been described as an example. However, the embodiment of the present invention is not limited to this, and it is also possible to use, as the light receiving device 4, a dedicated visible light detection device that receives reflected light separately from the camera 6 for detecting a communication signal.

(3) In the above embodiment, each of the signal transmission device 10 and the signal reception device 20 is configured to be able to acquire the information of the road reflector 90 by referring to the database 30 and is included in an image captured by the camera 6. The case where the information of the road reflector 90 can be acquired also by the image recognition processing of the road reflector 90 is described as an example. However, the embodiment of the present invention is not limited to this, and the configuration in which at least one of the signal transmission device 10 and the signal reception device 20 acquires the information of the road reflector 90 only by image recognition processing without referring to the database 30. Alternatively, the road reflector 90 information may be acquired only by referring to the database 30 without performing image recognition processing.

(4) In the above embodiment, the case where the vehicle communication device according to the present invention is provided in an automobile as an example of the vehicle 2 has been described as an example. However, the embodiment of the present invention is not limited to this, and the vehicle communication device according to the present invention may be provided in a vehicle 2 (for example, a bicycle) other than an automobile.

(5) Regarding other configurations as well, the embodiments disclosed herein are illustrative in all respects, and embodiments of the present invention are not limited thereto. In other words, configurations that are not described in the claims of the present application can be modified as appropriate without departing from the object of the present invention.

  INDUSTRIAL APPLICABILITY The present invention can be used for a vehicle communication device for performing communication between vehicles and a communication method for a vehicle communication device for performing communication between vehicles.

1: Vehicle communication device 2: Vehicle 2c: Oncoming vehicle 3: Headlamp 4: Light receiving device 10: Signal transmitting device 12: Irradiation range changing device 20: Signal receiving device 30: Database 90: Road reflector B: Irradiation range V: Visible light

Claims (8)

A vehicle communication device for performing communication between vehicles,
A headlamp on the vehicle,
A signal transmission device for irradiating visible light superimposed with a communication signal from the headlamp,
The signal transmission device is configured to superimpose the communication signal on the visible light emitted from the headlamp when a road reflector is present within the reach of the visible light emitted from the headlamp. Vehicle communication apparatus for executing The signal transmission device includes an irradiation range changing device that changes an irradiation range in which the intensity of visible light emitted from the headlamp is equal to or higher than a predetermined intensity,
The vehicle communication device according to claim 1, wherein the irradiation range changing device sets the irradiation range so as to include the road reflector during execution of the signal superimposing process.   When the oncoming vehicle is present in the irradiation range set to include the road reflector during execution of the signal superimposing process, the irradiation range changing device does not include the oncoming vehicle. The vehicle communication device according to claim 2, wherein an irradiation range is set.   The signal transmission device is within the reach range by referring to a database storing information of road reflectors installed in various places, or by image recognition processing of a road reflector included in an image taken in front of the host vehicle. The communication apparatus for vehicles as described in any one of Claim 1 to 3 which acquires the information of the road reflector which exists in the. A vehicle communication device for performing communication between vehicles,
A light receiving device provided in the vehicle;
A signal receiving device for detecting a communication signal superimposed on visible light received by the light receiving device,
The light receiving device is configured to receive reflected light that is irradiated from a headlamp of another vehicle and reflected by a road reflector,
The signal receiving device is a vehicle communication device that detects the communication signal superimposed on the reflected light.   The signal receiving device may be configured to refer to a database storing information of road reflectors installed in various places, or to perform image recognition processing of a road reflector included in an image obtained by photographing the front of the host vehicle. The vehicle communication device according to claim 5, wherein the communication signal superimposed on the reflected light is detected based on the acquired information. A communication method for a vehicle communication device that performs communication between vehicles,
Using a signal transmission device provided in the vehicle communication device, comprising a signal superimposing step of superimposing a communication signal on visible light emitted from a vehicle headlamp;
A communication method for executing the signal superimposing step when a road reflector is present within a range of visible light emitted from the headlamp. A communication method for a vehicle communication device that performs communication between vehicles,
Using a signal receiving device provided in the vehicle communication device, comprising a signal detection step of detecting a communication signal superimposed on visible light received by a light receiving device provided in the vehicle;
A communication method for executing the signal detection step when the light receiving device receives reflected light that is irradiated from a headlamp of another vehicle and reflected by a road reflector.

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