JP2006130996A - Lighting fixture for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lighting fixture installed in a vehicle capable of eliminating the problem of the intra-vehicle space by conducting optical communication from/to the vehicle through utilization of the lighting fixture and precluding interference with an apparatus using electric waves. <P>SOLUTION: The lighting fixture for the vehicle includes a lighting control circuit 10 for lighting up a tail lamp TL using a light emitting element as a light source, and the lighting control circuit 10 is equipped with a high-frequency modulation part 103 to control lighting of the light source with a high frequency such as not able to be discerned by the visual sense of human being on the basis of the data to be transmitted. The tail lamp TL is lighted up with the lighting current modulated with high frequency during the data period set periodically in whichever case the tail lamp TL is lighted or put off, and it is possible to perform the optical communication to transmit the data to the following vehicle using the tail lamp TL, which allows eliminating any independent communication apparatus for inter-vehicle communication or the road-vehicle communication. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vehicular lamp that enables optical communication between a host vehicle and another vehicle in order to ensure safe driving of a vehicle such as an automobile.

In order to ensure safe driving of vehicles such as automobiles, for example, current position data, vehicle speed data, road surface monitoring data ahead, ID data for recognizing the own vehicle, etc. are given to subsequent vehicles and oncoming vehicles. It has been proposed to transmit using communication means. By receiving these data, the succeeding vehicle and the oncoming vehicle can obtain the current traveling state of the vehicle and the road surface condition of the traveling location, and the reference for the following vehicle and the oncoming vehicle to travel safely. It becomes possible to. As such communication between vehicles (hereinafter referred to as inter-vehicle communication), for example, Patent Literature 1 discloses an inter-vehicle communication device for performing communication with other vehicles traveling in front of or behind the host vehicle. Proposed technology has been proposed. The inter-vehicle communication device of Patent Document 1 employs a communication method using radio waves. On the other hand, in recent years, an optical communication system that performs inter-vehicle communication using light has also been proposed.
JP 2003-317198 A

  In inter-vehicle communication using radio waves as in the technology of Patent Document 1, it is necessary to equip the vehicle with an inter-vehicle communication device, and the vehicle must have a space for it, and the vehicle can be downsized or a living space can be secured. It becomes an obstacle when doing. In particular, inter-vehicle communication is often performed between the preceding vehicle and the following vehicle. To that end, it is necessary to equip the front and rear parts of the vehicle with inter-vehicle communication devices, but the front and rear parts of the vehicle are used for lighting. In addition to these lamps, it is extremely difficult to secure a space for arranging the inter-vehicle communication device separately from these lamps. In addition, when performing inter-vehicle communication using radio waves, the radio waves may cause interference with radio and other devices using radio waves, and may hinder the normal operation of these devices. In vehicle-to-vehicle communication using light, it is necessary to equip the vehicle with a vehicle-to-vehicle communication device for transmitting and receiving light, and in order to secure space for equipment in the vehicle, The same, no solution.

  An object of the present invention is to make it possible to eliminate the problem of space in a vehicle and prevent interference with radio wave equipment by enabling optical communication in the vehicle using a lamp mounted on the vehicle. The vehicular lamp is provided.

  The present invention is a vehicular lamp using a light emitting element as a light source, and includes a lighting control circuit for lighting the light source, and the lighting control circuit has a light source at a high frequency that cannot be recognized by human vision based on information. It is characterized by comprising high frequency modulation means for controlling the lighting of. Here, the lighting control circuit is a lighting control unit for turning on and off the light source according to the driving operation, a flashing control unit including a high frequency modulation means, and outputs of the lighting control unit and the flashing control unit. It is preferable to provide a connector branch circuit that integrates and turns on / off / flashes the light source. The high-frequency modulation means sets a periodic data period on the time axis and modulates the lighting current supplied to the light source in the data period. Moreover, in this invention, it is preferable to comprise so that the lane mark marked on the road surface where a vehicle drive | works with the light radiate | emitted from a light source may be illuminated.

  According to the present invention, it is possible to perform optical communication in a vehicle using the lamp by performing high-frequency modulation of the lighting of the lamp based on data transmitted during the data period when the lamp of the vehicle is turned on or off. . Therefore, it is only necessary to change a part of the circuit of the existing lighting control circuit, no new equipment for transmitting and receiving light is required, the problem of space in the vehicle can be solved, and the use of radio waves because of optical communication It is also possible to prevent interference with the device.

  Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a conceptual configuration diagram of an embodiment in which the present invention is applied to an automobile, and various lamps mounted on the rear part of the automobile CAR in order to enable information to be transmitted to the following vehicle by optical communication. A stop lamp SL, a tail lamp TL, a turn signal lamp TSL, and a backup lamp BUL are provided. As will be described later, these lamps are composed of light emitting elements capable of blinking control at a high frequency, for example, lamps using LEDs as light sources. In addition, a lighting control circuit 10 for lighting each of the lamps is provided, and the lighting control circuit 10 includes a lighting control unit 101 and a blinking control unit 102. The on / off control unit 101 includes a stop switch SSW interlocked with a brake pedal, a tail lamp switch TSW operated integrally with a head lamp switch, a turn signal switch TSSW operated when changing a traveling direction, and a reverse gear. A backup switch BSW that is operated when the switch is turned on is connected, and when these switches are turned on, the lamps are turned on or blinked with the vehicle battery BAT as a power source under the control of the lighting control unit 101. It is like that.

  Regarding the circuit configuration and operation of the on / off controller 101 for lighting or blinking the lamps SL, TL, BUL, TSL when the switches SSW, TSW, TSSW, BSW are turned on, the existing on / off control is performed. The detailed description is omitted here. On the other hand, in the present embodiment, the blinking control unit 102 provided in the lighting control circuit 10 is provided with a high frequency modulation unit 103, and the high frequency modulation unit 103 can modulate the blinking of each lamp. It is configured. In addition, the outputs of the on / off control unit 101 and the blinking control unit 102 are output to the connector branch circuit 11, and the outputs of the control units 101 and 102 are integrated in the connector branch circuit 11. Any one lamp or a plurality of lamps can be selected, and the selected lamp can be set to a state where it can be lit or blinked.

  A data multiplexing unit 12 is connected to the high-frequency modulation unit 103, and is configured to perform high-frequency modulation on the lighting current from the in-vehicle battery BAT using the modulation data output from the data multiplexing unit 12. The data multiplexing unit includes a current position sensor 21 for measuring the position of the vehicle such as GPS, a vehicle speed sensor 22 for measuring the vehicle speed of the vehicle, and a lane mark (white line, yellow line, etc.) marked on the road surface. A road surface monitoring sensor 23 that recognizes an image of a lane mark imaged by an image sensor 231 such as a CCD for imaging by an image recognition unit 232 and outputs road surface monitoring data such as a relative positional relationship between the lane mark and the vehicle. The current position data, vehicle speed data, and road surface monitoring data are input from the sensors 21, 22, and 23, respectively. Further, a memory 24 in which ID data for recognizing the own vehicle is recorded is connected. The data multiplexing unit 12 multiplexes the data inputted from each of the sensors 21, 22 and 23 and the ID data recorded in the memory 24 as needed based on the signal from the CPU 100, and the high frequency modulation unit To 103. Normally, the current position data, the vehicle speed data, and the road surface monitoring data are often analog signals, so that the output of each sensor is used to superimpose ID data that is digital data recorded in the memory. Is converted into digital data by an A / D (analog / digital) converter, but is not shown here.

  Further, as shown in FIG. 1, a light receiving element 31 such as a photodiode that receives light transmitted from a preceding vehicle and a light receiving current received by the light receiving element 31 are amplified at the front of the car CAR. An amplifier 32, an extractor 33 that extracts only current during a specific time axis from the amplified received light current, a data separator 34 that separates the extracted data into individual data, and high-frequency demodulation of the separated data A high-frequency demodulator 35 that inputs individual demodulated data that has been demodulated at a high frequency to the CPU 100 and allows the CPU 100 to decode the data.

  In this configuration, when the various switches are selectively or simultaneously turned on, the on / off control unit 101 supplies the power of the in-vehicle battery BAT to the corresponding lamp via the connector branch circuit 11 to turn on the lamp. At the same time, the current position data measured by the current position sensor 21 is input to the high frequency modulation unit 103 in the lighting control circuit 10 as modulation data through the data multiplexing unit 12. The high frequency modulation unit 103 performs high frequency modulation on the lighting current supplied from the in-vehicle battery BAT based on the current position data, and supplies it to one of the lamps selected in the connector branch circuit 11, for example, the tail lamp TL. In this case, the high-frequency modulation is performed by performing on / off control of the lighting current at high speed based on the modulation data. As a result, the tail lamp TL is controlled to be turned on / off by the high-frequency modulated lighting current.

  That is, when the tail lamp TL is in an extinguished state, a high-frequency modulated current is supplied as a lighting current to the tail lamp TL. Here, so-called PWM (pulse width modulation) is used as the high-frequency modulation, which controls the on / off time of the lighting current based on the data value. Here, as shown in FIG. 2 (a), the lighting current is set such that one period T is set to 200 to 300 mS (milliseconds), and a period of 1 to 2 mS of the one period T is set as a data period D. The period is defined as an effective period E for turning on / off the lamp. Then, the time for actually supplying the lighting current with respect to the time of the data period D, that is, the pulse width PW of the lighting current is controlled based on the modulation data. As a result, the tail lamp TL is turned on with a pulse width PW over the whole or a part of the data period D corresponding to the modulation data, and is turned off during the remainder. Therefore, the tail lamp TL flashes at a high frequency and transmits a modulation signal, but since this flashing is less than the resolution on the time axis of the human eye, the occupant of the following vehicle cannot recognize the flashing, A passenger in the following vehicle does not recognize that the tail lamp TL is lit.

  On the other hand, the succeeding vehicle receives the blinking light of the tail lamp TL by the light receiving element 31 of the succeeding vehicle and outputs a received light current. Of the current obtained by amplifying the received light current by the amplifier 32, only the current in the data period D is obtained. Is extracted by the extractor 33, and only the target data is separated by the separator 34, and the high frequency demodulator 35 executes high frequency demodulation based on the separated pulse width PW of the lighting current. The extraction of the current in the data period D in the extractor 33 is performed by a timing signal (synchronization signal) or the like. However, since this technique is a known technique in a normal communication technique, detailed description thereof is omitted. . The same applies to the configuration and operation of the separator 34 that separates data. Then, the demodulated data is decoded by the CPU 100, so that the succeeding vehicle can recognize the current position data transmitted from the preceding vehicle. By referring to this current position data, the succeeding vehicle can compare the current position of the own vehicle with the current position of the preceding vehicle, and determine whether the inter-vehicle distance from the preceding vehicle is appropriate, etc. It can be used for safe driving.

  On the other hand, even when the tail lamp TL is turned on when traveling at night or the like, it is possible to perform optical communication with the following vehicle by supplying a modulation current that is high-frequency modulated to the tail lamp TL. In this case, as shown in FIG. 2B, during the effective period E, the lighting current is continuously supplied to turn on the tail lamp TL, and in the remaining data period D of about 1 to 2 mS, the data The time (pulse width) PW of the lighting current in the period D is controlled based on the modulation data. As a result, the tail lamp TL is turned on with a pulse width PW extending over all or part of the data period, and is turned off during the remainder. In the data period D, the tail lamp TL blinks at a high frequency, but since this blinking is less than the resolution on the time axis of the human eye, the occupant of the following vehicle recognizes that the tail lamp TL is blinking. There is no, and it seems that it lights continuously, so there is no danger.

  Therefore, the blinking light of the tail lamp TL is received by the light receiving element 31 of the succeeding vehicle, and the received light current is output. Only the current in the data period is extracted from the current obtained by amplifying the received light current, and is required. By separating high-frequency demodulated data and decoding the demodulated data, the succeeding vehicle can recognize the current position data transmitted from the preceding vehicle in the same way as when the tail lamp TL is extinguished. It can be used for driving.

  As described above, the lighting current is high-frequency modulated for the data period D periodically set on the time axis when the tail lamp TL is turned off and when the tail lamp TL is turned on, so that the tail lamp TL is turned off or turned on. Optical communication is also possible. Since the blinking of the tail lamp TL due to the high frequency modulation is not visually recognized by the passengers of other vehicles, the passengers of other vehicles are not confused. In addition, since the lamps already installed in the vehicle are used for the communication between the vehicles in this way, the communication between the vehicles can be performed only by partially changing the circuit of the lighting control circuit installed in the existing vehicle. Thus, an independent vehicle-to-vehicle communication device is not required, so that the problem of in-vehicle space can be solved, and since it is an optical communication, it is possible to prevent interference with a radio wave using device.

  As shown in FIG. 3, the high-frequency modulation in the present invention is a PCM (modulation that performs modulation so as to become a PC (pulse code) in which a plurality of pulsed lighting signals are code-arranged on the time axis in the data period D. Pulse code modulation) can be used. Or although illustration is abbreviate | omitted, it is also possible to use the light intensity modulation which makes the intensity | strength (brightness) of the lighting signal in a data period differ, ie, AM (amplitude modulation). Further, the lighting current in the data period may be an AC signal, and this AC signal may be FM (frequency modulation) or PM (phase modulation). However, in AM, it may be difficult to accurately transmit and receive data because the light intensity changes due to optical communication obstacles such as dirt on the surface of the lamp and rainy weather. Also, FM and PM require a configuration for generating an AC signal, and each circuit for transmission and reception tends to be complicated.

  The above configuration shows an example in which optical communication is performed by performing high-frequency modulation of the lighting current of the tail lamp TL with the current position data. However, as described above, the present invention can be in any of the lamp lighting state and the lighting off state. However, since data can be transmitted by optical communication, the present invention can be similarly applied to other stop lamps SL, turn signal lamps TSL, and backup lamps BUL that are irregularly turned on or off. Nor. Further, the present invention can be configured to transmit data to a preceding vehicle. In this case, the present invention can be applied to a turn signal lamp, a fog lamp, and a clearance lamp provided at the front of the vehicle. it can. Of course, when the headlamp is composed of a light emitting element, it can be applied to the headlamp.

  Moreover, in the said Example, since the lighting-off control part 101 and the blink control part 102 are set as the independent structure, a failure | failure arises in the system | strain of the blink control part 102 for various reasons, and the transmission of data as mentioned above cannot be performed. Even if a situation occurs, the lighting control unit 101 is not affected, and it is possible to ensure normal lighting of stop lamps, turn signal lamps and the like important for traffic safety.

  In the above embodiment, the current position data of the own vehicle is transmitted to the following vehicle by optical communication. However, the vehicle speed data of the own vehicle detected by the vehicle speed sensor 22 may be transmitted. Alternatively, it is possible to transmit the ID data of the own vehicle recorded in the memory 24. Furthermore, it is also possible to transmit road surface monitoring data obtained by image recognition of the road surface lane mark imaged by the image sensor 231 by the image recognition unit 232. In particular, since the data multiplexing unit 12 is provided in the present embodiment, the current position data, vehicle speed data, road surface monitoring data, and ID data may be time-division multiplexed in the data multiplexing unit to form modulation data, and a plurality of data may be simultaneously transmitted. It is possible to send.

  Examples of the lane mark include a rear road center line of the own vehicle and a rear road shoulder lane mark. Sunlight is used in the daytime as the main illumination light when the lane mark is imaged by the image sensor, but the taillight or other lamp illumination light is used as the main illumination light or auxiliary illumination light at night or in a tunnel. Is done. For example, FIG. 4 is a schematic plan view of a state in which the rear road surface shoulder lane mark LM is monitored, and the road surface shoulder lane mark LM is illuminated with light emitted from the tail lamp TL when the tail lamp TL is continuously lit. The road surface monitoring data can be obtained by capturing the road shoulder lane mark LM with the image sensor 231 of the road surface monitoring sensor 23 and recognizing the image. Then, the obtained road surface monitoring data is monitored by the CPU 100 of the own vehicle, and the CPU 100 determines whether or not the own vehicle is traveling at an appropriate position along the lane mark LM, and gives a warning to the driver depending on the situation. It can be set to do. In addition, the road surface monitoring data is modulated at a high frequency as described above, and the tail lamp TL or other lamps are flashed at a high frequency and transmitted to the following vehicle. For example, it can be estimated that the preceding vehicle is dozing, etc., and can be used for safe driving.

  Other stop lamps, turn signal lamps, and backup lamps other than the tail lamp can be used as the main illumination light or auxiliary illumination light of the lane mark when lit. In addition, even when each lamp is extinguished, when optical communication using the above-described high frequency modulation is performed, the light is turned on during a data period in which high frequency modulation is performed. It can be used as illumination light or auxiliary illumination light. However, since the lighting time by high frequency modulation is as extremely short as 1 to 2 mS as described above, it can be used when the imaging capability of the image sensor has a sensitivity corresponding to this short lighting time. In this case, the shutter speed of the shutter that opens and closes the light receiving path of the image sensor is set appropriately in accordance with the frequency of the high frequency modulation, and the light receiving sensitivity is increased by increasing the charge accumulation time in the image sensor. Good.

  In the above description, inter-vehicle communication has been explained. However, each vehicle transmits data to a traffic monitoring sensor that is fixedly installed on the road, and the traffic monitoring sensor is under the jurisdiction based on the received data of each vehicle. The present invention can be similarly applied even when a system for sending road information and the like to other vehicles in the vehicle is constructed.

It is a block block diagram of the principal part of the Example which applied this invention to the lamp | ramp of a motor vehicle. It is a timing waveform diagram of a lighting current when PWM is adopted for high frequency modulation. It is a timing waveform diagram of a lighting current when PCM is adopted for high frequency modulation. It is a schematic plan view of the state which monitors a lane mark.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Lighting control circuit 11 Connector branch circuit 12 Data multiplexing part 21 Present position data 22 Vehicle speed data 23 Road surface monitoring data 24 Memory (ID data)
31 Photodetector 32 Amplifier 33 Extractor 34 Separator 35 High Frequency Demodulator 100 CPU
101 ON / OFF control unit 102 Flashing control unit 103 High frequency modulation unit

Claims (4)

  A vehicular lamp using a light emitting element as a light source, comprising a lighting control circuit for lighting the light source, wherein the lighting control circuit is in a lighting state of the light source at a high frequency that cannot be recognized by human vision based on information A vehicle lamp comprising high frequency modulation means for controlling   The lighting control circuit integrates the lighting control unit for turning on and off the light source according to the driving operation, the blinking control unit including the high-frequency modulation means, and the outputs of the lighting control unit and the blinking control unit. The vehicle lamp according to claim 1, further comprising a connector branch circuit that turns on, turns off, and blinks the light source.   3. The vehicular lamp according to claim 1, wherein the high-frequency modulation means sets a periodic data period on a time axis and modulates a lighting current supplied to the light source in the data period. 4. The vehicular lamp according to claim 1, wherein a lane mark marked on a road surface on which the vehicle travels is illuminated with light emitted from the light source.

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