JP2009237944A - On-vehicle communication device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an on-vehicle communication device allowing a transmission partner to appropriately direct a light receiving range of a light receiving part. <P>SOLUTION: The on-vehicle communication device comprises: a first light receiving part for receiving a first optical signal with first directivity transmitted from a first light source of the other vehicle or road side equipment; a second light receiving part for receiving a second optical signal with second directivity higher than the first directivity, transmitted from a second light source of the other vehicle or the road side equipment; an information output part for demodulating the second optical signal received by the second receiving part and outputting information included in the second optical signal; and a control part for controlling the light receiving range of the second light receiving part. The control part detects the direction of the first light source based on the first optical signal received by the first light receiving part, and turns the light receiving range of the second light receiving part in the detected direction of the first light source. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an in-vehicle communication device that acquires information from another vehicle or roadside equipment having a first light source and a second light source by optical communication.

2. Description of the Related Art Conventionally, a technique for performing optical communication between vehicles by receiving optical data transmitted from a preceding vehicle with an optical receiver installed in the vehicle is known (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 9-81899

  However, since a single optical receiver can only receive light from a specific range, it is different from other vehicles (front vehicles) existing in a specific direction as in the configuration described in Patent Document 1 above. Can only communicate. On the other hand, although it is possible to install a plurality of optical receivers to cover all directions of the vehicle, it is also necessary to always operate all the optical receivers from the viewpoint of processing load and energy. Inefficient. On the other hand, it is possible to variably control the light receiving range of the optical receiver so as to cover all directions of the vehicle using a single optical receiver, but the light receiving range of the optical receiver is appropriately directed to the transmission partner. It is not easy to make it happen.

  Accordingly, an object of the present invention is to provide an in-vehicle communication device that can appropriately direct the light receiving range of a light receiving unit to a transmission partner.

To achieve the above object, the first invention is an in-vehicle communication device that acquires information from another vehicle or roadside equipment having a first light source and a second light source by optical communication,
A first light receiving unit that receives a first optical signal having a first directivity transmitted from the first light source;
A second light receiving unit that receives a second optical signal transmitted from the second light source and having a second directivity higher than the first directivity;
An information output unit that demodulates the second optical signal received by the second light receiving unit and outputs information included in the second optical signal;
A control unit for controlling a light receiving range of the second light receiving unit,
The control unit detects the direction of the first light source based on the first optical signal received by the first light receiving unit, and in the direction of the detected first light source, The light receiving range is directed.

2nd invention is the vehicle-mounted communication apparatus which concerns on 1st invention,
The second light receiving unit is composed of a plurality of light receiving units in which at least a part of the light receiving range is different from each other,
The control unit controls a light receiving range of the second light receiving unit by operating a specific light receiving unit among the plurality of light receiving units.

3rd invention is the vehicle-mounted communication apparatus which concerns on 1st invention,
The second light receiving unit includes a mechanism in which a light receiving direction is varied using an actuator as a power source,
The control unit drives the actuator to control a light receiving range of the second light receiving unit.

4th invention is the vehicle-mounted communication apparatus which concerns on 1st invention,
The second light receiving unit starts reception processing when the first light receiving unit receives a first optical signal.

5th invention is the vehicle-mounted communication apparatus which concerns on 1st invention,
The control unit starts control of a light receiving range of the second light receiving unit when the first light receiving unit receives a first optical signal.

6th invention is the vehicle-mounted communication apparatus which concerns on 1st invention,
The first light source is a diffused light source incorporated in a headlight or roadside equipment of another vehicle,
The second light source is a directional light source incorporated in a headlight or roadside equipment of another vehicle.

7th invention is the vehicle-mounted communication apparatus which concerns on 6th invention,
The second light source is an LED.

The eighth invention is the in-vehicle communication device according to the first invention,
The information included in the second optical signal includes a message from a driver of the other vehicle.

A ninth invention is the in-vehicle communication device according to the first invention,
The information included in the second optical signal includes traffic information generated by roadside equipment.

A tenth aspect of the present invention is the in-vehicle communication device according to the first aspect,
The first light source is a headlight of another vehicle;
The first optical signal is generated by a passing operation that alternately switches a headlight direction of another vehicle up and down.

  ADVANTAGE OF THE INVENTION According to this invention, the vehicle-mounted communication apparatus which makes it possible to make the light transmission range of a light-receiving part point appropriately at a transmission other party is obtained.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is a configuration diagram showing a main part of an embodiment of an in-vehicle communication device 1 according to the present invention. The in-vehicle communication device 1 is mounted on a vehicle. Below, the vehicle which becomes the center of description among the vehicles by which the vehicle-mounted communication apparatus 1 is mounted is also called "the own vehicle."

  The in-vehicle communication device 1 is configured around a control device 10. The control device 10 is configured by a microcomputer and includes a CPU, a ROM, a RAM, an I / O, a communication circuit, and the like. Note that the control device 10 may be embodied by another existing ECU such as a navigation ECU of the navigation device, or may be embodied as another new dedicated ECU, or by two or more ECUs. It may be realized in cooperation.

  The control device 10 includes, as main functional units, a transmission data input unit 11, a transmission content generation unit 12, a transmission unit 13, a continuous reception unit 14, a camera switching unit 15, a recording processing unit 16, a data analysis unit 17, and a reception data output. The unit 18 is provided. Each of these units 11 to 18 may be realized as software by the CPU executing a program in the ROM.

  A headlight 20 and an LED 22 are connected to the control device 10. The headlight 20 may be a normal headlight and includes a diffused light source that can illuminate a specified range. The LED 22 may be mounted in the vicinity of the headlight 20 and incorporated in the headlight 20. Here, in order to prevent the description from becoming complicated, the description will be continued assuming that the headlight 20 does not include the LED 22 therein. The LED 22 is an example of a directional light source having higher directivity than the headlight 20, and a laser light source or the like may be used.

  The control device 10 includes a headlight sensor 30 that detects light from the headlight 20 of another vehicle, and a camera 32.

  The headlight sensor 30 may be configured by an optical sensor or the like. The headlight sensor 30 is preferably a vehicle that can detect a wide range of light from the headlight 20 of another vehicle that can be emitted from all directions of the vehicle depending on the positional relationship between the vehicle (own vehicle) and the other vehicle. Are provided at a plurality of sites. That is, the headlight sensors 30 may be provided at the front and left and right sides of the vehicle so as to be able to detect light from the headlights 20 of other vehicles that can be irradiated from the front and left and right sides of the vehicle. It may be provided at the rear of the vehicle so that light from the headlight 20 of another vehicle that can be irradiated from the vehicle can be detected. In the following, as an example, the headlight sensor 30 detects the light from the headlight 20 of another vehicle that can be irradiated from the front, left and right sides of the vehicle, and the rear of the vehicle. Are provided respectively.

  The camera 32 constitutes a light receiving unit that receives light (transmission signal described later) from the LED 22 of another vehicle, and the vehicle and the image sensor such as a CCD (charge-coupled device) or a CMOS (complementary metal oxide semiconductor). Image the external environment. Preferably, the direction of the optical axis of the camera 32 may be variable so that light from the headlight 20 of another vehicle that can be irradiated from all directions of the vehicle can be detected in a wide range. In this case, the camera 32 includes a mechanism in which a light receiving direction is varied using an actuator (not shown) such as an electric motor as a power source. The degree of freedom of rotation of the camera 32 may be rotation about one axis in a substantially vertical direction so that the orientation can be adjusted in a horizontal plane. Alternatively, the camera 32 is preferably arranged at a plurality of locations in the vehicle in such a manner that at least a part of the light receiving range is different from each other so that light from the LED 22 of another vehicle that can be irradiated from all directions of the vehicle can be detected in a wide range. Provided. That is, the cameras 32 may be provided at the front and left and right sides of the vehicle so as to be able to detect light from the LED 22 of the other vehicle that can be emitted from both the front and left and right sides of the vehicle. You may provide in the vehicle rear part so that the light from LED22 of another vehicle can be detected. In the following, as an example, the cameras 32 are provided at the front part of the vehicle, the left and right side parts, and the rear part of the vehicle so that light from the LED 22 of the other vehicle that can be irradiated from the front side, the left and right sides and the rear side of the vehicle can be detected. It shall be.

  A microphone 40, a display 42 and a speaker 44 are connected to the control device 10. The microphone 40, the display 42, and the speaker 44 are provided in the vehicle interior. The display 42 may be shared with a display used in another device (for example, a navigation device), or may be a dedicated display. The display 42 may have a user interface such as a touch switch.

  Next, information transmission processing to other vehicles realized by the control device 10 will be described.

  FIG. 2 is a flowchart showing an example of information transmission processing to another vehicle realized by the control device 10.

  In step 100, transmission data from a user (typically a driver) is input to the transmission data input unit 11. The transmission data may be audio data input from the microphone 40 or data input via the display 42, for example. The transmission data is input when the driver of the vehicle wants to convey a message to the driver of another vehicle. For example, at the intersection, when a driver of a vehicle wants to give a message “You can turn” to another driver waiting for a right turn, he / she speaks to the microphone 40 “You can turn”. Thus, the transmission data is input, or the message “You can turn” is input or selected via the display 42, and the transmission data is input. There are a wide variety of contents of transmission data and input methods, and any form may be adopted.

  In step 102, the transmission content generation unit 12 generates a transmission signal for performing visible light communication this time, according to the transmission data input to the transmission data input unit 11.

  In step 104, the transmission unit 13 first performs a communication start signal transmission process by the headlight 20 prior to transmission of a transmission signal. Specifically, the transmission process of the communication start signal by the headlight 20 is performed by performing a passing operation that alternately switches the direction of the headlight 20 up and down in a short cycle. Note that the communication start signal may be a signal generated using the headlight 20 and may be generated by an operation other than the passing operation.

  In step 106, the transmission unit 13 executes transmission signal transmission processing (visible light communication processing) by the LED 22 subsequent to the communication start signal transmission processing by the headlight 20 in step 104. The transmission of the transmission signal by the LED 22 may be executed after the continuous transmission processing of the communication start signal by the headlight 20 in step 104 is executed for a predetermined time (for example, 1 to 2 seconds). Transmission of the transmission signal by the LED 22 is realized by modulating the frequency, amplitude, and the like of the light generated from the LED 22 with the transmission signal. The form of this visible light communication is arbitrary. For example, as described in JP-A-2007-207175, the transmission signal may be transmitted by controlling the blinking or the amount of light generated from the LED 22.

  Next, information reception processing from another vehicle realized by the control device 10 will be described.

  FIG. 3 is a flowchart illustrating an example of information reception processing from another vehicle realized by the control device 10.

  In step 200, the continuous reception unit 14 performs a reception process of a communication start signal (see step 104) transmitted from another vehicle. A communication start signal transmitted from another vehicle is received (detected) by the headlight sensor 30. This reception process is continuously executed. This is because the timing at which the communication start signal is transmitted from the other vehicle cannot be predicted on the own vehicle side.

  In step 202, the continuous reception unit 14 executes a specifying process of the source direction of the received communication start signal (that is, the direction in which the other vehicle that transmitted the received communication start signal exists). The transmission source direction is most simply specified by specifying which headlight sensor 30 of the plurality of headlight sensors 30 has received the communication start signal, and mounting the headlight sensor 30 that has received the communication start signal. It may be specified based on the position. For example, when the headlight sensor 30 at the front of the vehicle receives a communication start signal, it may be determined that the transmission source direction is the front of the vehicle. Of course, depending on the configuration and performance of the headlight sensor 30, a more detailed direction may be specified instead of a rough direction such as the front of the vehicle or the side of the vehicle.

  In step 204, the camera switching unit 15 executes a process of switching the light reception range of the camera 32. As a result, the light receiving range of the camera 32 is changed to a light receiving range in which a transmission signal from the LED 22 of the other vehicle can be received. Specifically, the light receiving range of the camera 32 is switched in the transmission source direction specified in step 202 above. For example, when the headlight sensor 30 in the front part of the vehicle receives a communication start signal, since the transmission source direction is the front of the vehicle, among the plurality of cameras 32, the camera 32 mounted on the front part of the vehicle is in an operating state. The other cameras 32 are maintained in a non-operating state. In the case of a configuration in which the orientation of the camera 32 is variable, the camera 32 is activated when a communication start signal is received, and then the optical axis is directed to the transmission source direction specified in step 202 above. The direction of the camera 32 is adjusted.

  In step 206, the recording processing unit 16 performs a recording process of an image captured by the camera 32 whose light receiving range is controlled. Thereby, the reception data of the transmission signal from LED22 of another vehicle is accumulate | stored and memorize | stored.

  In step 208, the data analysis unit 17 analyzes the recorded image data and demodulates the transmission signal transmitted from the LED 22 of the other vehicle. The transmission signal from the LED 22 of the other vehicle may be demodulated in real time using a demodulation circuit without being subjected to recording processing.

  In step 210, the received data output unit 18 executes a process of notifying the driver of the analysis result in step 208. Specifically, based on the demodulation / decoding result of the transmission signal from the LED 22 of the other vehicle, the transmission data of the user (typically the driver) of the other vehicle is extracted, and the transmission data is displayed on the display 42 or It is output via the speaker 44. For example, in the above-described example, the message “You can turn” is output via the display 42 and the speaker 44.

  As described above, according to this embodiment, when the communication start signal is received by the headlight sensor 30, the recording process (or demodulation process) of the camera 32 is started, so that the camera 32 is always operated (continuous). Therefore, the power consumption and processing load can be reduced compared to the configuration in which recording is continuously performed.

  Further, according to the present embodiment, when the communication start signal is received by the headlight sensor 30, the light receiving range of the camera 32 is directed to the source direction by specifying the source direction of the communication start signal. Can do. As a result, a transmission signal transmitted from another vehicle can be reliably received, and power consumption and processing load can be reduced as compared with a configuration in which continuous recording of the camera 32 is performed in all directions, for example. it can.

  Next, visible light communication between road vehicles will be described.

  FIG. 4 shows an example of a roadside facility 70 that provides information to the in-vehicle communication device 1 according to the present embodiment by visible light communication. The roadside equipment 70 may be installed on the road or on the shoulder of the road, or may be installed at a high position on the road or around the road, such as a traffic light.

  In the example illustrated in FIG. 4, the roadside facility 70 includes a rotating lamp 72 as a diffusion light source, an LED display 74, and a display control device 76. The LED display 74 includes a plurality of LEDs as a directional light source, and outputs traffic information by a combination of LEDs that are lit. In the example shown in FIG. 4, a predetermined LED is lit so as to be a character “being under construction for 200 meters ahead”. The display control device 76 controls the display on the LED indicator 74 and transmits a transmission signal to the in-vehicle communication device 1 using the LED in the LED indicator 74. The transmission signal includes traffic information representing more detailed content than the display on the LED display 74. For example, in the above example, the traffic signal includes detailed traffic information such as "the road ahead is 200m ahead and the left lane is under construction". It's okay. In addition, when the display on the LED display 74 is “This is 2 km ahead, 3 km traffic jam”, the transmission signal is “There is a traffic accident ahead, 2 km ahead, and the left lane is closed. Detailed traffic information such as “3 km traffic jam” may be included. The transmission of the transmission signal by the LED of the LED display 74 is realized by modulating the frequency and amplitude of the light generated from the LED of the LED display 74 by the transmission signal, similarly to the transmission of the transmission signal by the LED 22. The form of this visible light communication is arbitrary. For example, as described in Japanese Patent Application Laid-Open No. 2007-207175, the transmission signal is transmitted by controlling the blinking or the amount of light generated from the LED of the LED display 74. Also good.

  When displaying some traffic information on the LED display 74, the display control device 76 turns on the rotation lamp 72 and uses the LED of the LED display 74 to provide more detailed traffic than the display on the LED display 74. A transmission signal including information is periodically transmitted (broadcast). At this time, the light from the rotating lamp 72 that is turned on functions as a communication start signal and is received by the headlight sensor 30 of the vehicle. Similarly, on the vehicle side, the processing from step 202 in FIG. 3 is executed, the transmission signal from the roadside equipment 70 is demodulated, and traffic information (detailed traffic information) from the roadside equipment 70 is displayed on the display 42 and the speaker 44. Will be output via.

  Thus, even in visible light communication between road vehicles, according to the present embodiment, when the communication start signal is received by the headlight sensor 30, the recording process (or demodulation process) of the camera 32 is started. Compared with a configuration in which the camera 32 is always operated (a configuration in which continuous recording is performed), power consumption and processing load can be reduced.

  Further, even in visible light communication between road vehicles, when the communication start signal is received by the headlight sensor 30, the light receiving range of the camera 32 is directed to the transmission source direction by specifying the transmission source direction of the communication start signal. Can be made. Thereby, the transmission signal transmitted from the roadside equipment 70 can be reliably received, and the power consumption and the processing load can be reduced compared to the configuration in which the camera 32 continuously records in all directions, for example. Can do.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the present invention. Can be added.

  For example, in the embodiment described above, communication is performed using the headlamp 20 and the surrounding LEDs 22, but the present invention is not limited to this. For example, it is possible to perform communication using a brake lamp and its surrounding or built-in LED. In this case, the communication start signal may be transmitted to the other vehicle behind by turning on or blinking the brake lamp, and thereafter, the transmission signal may be transmitted to the other vehicle behind by the surrounding LED or the built-in LED.

  In the above-described embodiment, the camera 32 functions as a light receiving unit, but a light receiving unit that does not have a lens like the camera 32 may be configured.

It is a block diagram which shows the principal part of one Example of the vehicle-mounted communication apparatus 1 by this invention. 3 is a flowchart illustrating an example of information transmission processing to another vehicle realized by the control device 10; 3 is a flowchart illustrating an example of information reception processing from another vehicle realized by the control device 10; It is a figure which shows an example of the roadside equipment 70 which provides information with respect to the vehicle-mounted communication apparatus 1 of a present Example by visible light communication.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 In-vehicle communication apparatus 10 Control apparatus 11 Transmission data input part 12 Transmission content generation part 13 Transmission part 14 Continuous reception part 15 Camera switching part 16 Recording processing part 17 Data analysis part 18 Reception data output part 20 Headlight 30 Headlight sensor 32 Camera 40 Microphone 42 Display 44 Speaker 70 Roadside equipment 72 Rotating lamp 74 LED display 76 Display control device

Claims (10)

An in-vehicle communication device that acquires information from another vehicle or roadside equipment having a first light source and a second light source by optical communication,
A first light receiving unit for receiving a first optical signal having a first directivity transmitted from the first light source;
A second optical signal transmitted from the second light source and receiving a second optical signal having a second directivity higher than the first directivity;
An information output unit that demodulates the second optical signal received by the second light receiving unit and outputs information included in the second optical signal;
A control unit for controlling a light receiving range of the second light receiving unit,
The control unit detects the direction of the first light source based on the first optical signal received by the first light receiving unit, and in the direction of the detected first light source, A vehicle-mounted communication device characterized by directing a light receiving range. The second light receiving unit is composed of a plurality of light receiving units in which at least a part of the light receiving range is different from each other,
The in-vehicle communication device according to claim 1, wherein the control unit controls a light receiving range of the second light receiving unit by operating a specific light receiving unit among the plurality of light receiving units. The second light receiving unit includes a mechanism in which a light receiving direction is varied using an actuator as a power source,
The in-vehicle communication device according to claim 1, wherein the control unit drives the actuator to control a light receiving range of the second light receiving unit.   The in-vehicle communication device according to claim 1, wherein the second light receiving unit starts a reception process when the first light receiving unit receives the first optical signal.   The in-vehicle communication device according to claim 1, wherein the control unit starts control of a light receiving range of the second light receiving unit when the first light receiving unit receives the first optical signal. The first light source is a diffused light source incorporated in a headlight or roadside equipment of another vehicle,
The in-vehicle communication device according to claim 1, wherein the second light source is a directional light source incorporated in a headlight or roadside equipment of another vehicle.   The in-vehicle communication device according to claim 6, wherein the second light source is an LED.   The in-vehicle communication device according to claim 1, wherein the information included in the second optical signal includes a message from a driver of the other vehicle.   The in-vehicle communication device according to claim 1, wherein the information included in the second optical signal includes traffic information generated by roadside equipment. The first light source is a headlight of another vehicle;
The in-vehicle communication device according to claim 1, wherein the first optical signal is generated by a passing operation that alternately switches a headlight direction of another vehicle up and down.

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