Abstract:
A system and method for communication between an emitting motor vehicle (Ve) and at least one target, the emitting vehicle (Ve) including at least one light device, the method comprising the step of automatically modulating a light signal (S) emitted by the light device for a communication between the vehicle (Ve) and the target; and the light device being chosen from: a lighting device, a daytime running light (DRL), a position light.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to French Application No. 1054574 filed Jun. 10, 2010, which application is incorporated herein by reference and made a part hereof. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The invention relates notably to a method for communication between an emitting motor vehicle and a target. 
         [0004]    2. Description of the Related Art 
         [0005]    It is commonplace to make headlight calls, for example to warn other drivers of a hazard, by rapidly and manually switching on and off, a certain number of times, the road lighting (or headlight). 
         [0006]    In the automotive domain, numerous lighting devices use halogen or discharge lamps, notably of Xenon type. 
         [0007]    On these devices, the headlight call usually presents the following drawbacks. 
         [0008]    The rise time when a Xenon lamp is switched on may be relatively lengthy, which does not make it possible to make headlight flashes that are as close together as would be desired. 
         [0009]    The rise and fall time, above all when cold, for a halogen lamp is also relatively lengthy, which raises the same type of problem as mentioned above. 
         [0010]    Furthermore, on this type of halogen and Xenon lamps, it is difficult to provide an additional light intensity, namely a light intensity greater than the normal operating intensity. 
         [0011]    Finally, repeated headlight calls greatly reduce the life of the lamps. 
         [0012]    Moreover, there is a need to communicate easily, for example, between two vehicles. 
       SUMMARY OF THE INVENTION 
       [0013]    The aim of the invention is notably to overcome the above-mentioned drawbacks. 
         [0014]    Thus, the subject of the invention is a method for communication between an emitting motor vehicle and at least one target, the emitting vehicle including at least one light device, the method comprising the following step: 
         [0015]    automatically modulating a light signal emitted by the light device for a communication between the vehicle and the target. 
         [0016]    According to the invention, the light device is preferentially chosen from: a lighting device such as a low beam, high beam or fog beam, or, as a variant, a signalling device such as a daytime running light (DRL) or a position light. 
         [0017]    By virtue of the invention, the communication with, for example, another vehicle, can be conducted without hindrance to the driver of the emitting vehicle. 
         [0018]    This may be particularly advantageous in the case of a headlight call, for example, because the light pulses for this headlight call can be generated automatically, without the driver having to carry out complicated movements with his fingers which may hamper the driving. 
         [0019]    The invention thus makes it possible to enhance safety during driving. 
         [0020]    Preferentially, the light device comprises at least one light-emitting diode arranged to participate in the modulated light signal. 
         [0021]    The invention thus offers various advantages. 
         [0022]    For example, it is possible to exploit, for the implementation of the invention, the presence of light-emitting diodes (LEDs) and an associated control device that are already present on the vehicle. 
         [0023]    Furthermore, a light-emitting diode has a rise time when switched on and a fall time when switched off that are very short compared, notably, to a halogen or discharge lamp. 
         [0024]    Finally, an LED makes it possible to produce frequent bursts of light pulses without degrading its life, unlike, for example, a halogen lamp or a discharge lamp. 
         [0025]    Advantageously, the modulated light signal from the light device is arranged to be perceptible to the human eye. 
         [0026]    If necessary, the wavelength of the modulated light signal duly produced by the light device is chosen to be in the visible domain of the light spectrum. 
         [0027]    In an exemplary implementation of the invention, the modulated light signal is modulated in light intensity, notably in a periodic manner. 
         [0028]    Advantageously, the duly modulated light signal comprises a train of light pulses, notably of periodic light pulses of constant or progressive period, the number of pulses being, for example, between 1 and 10 per pulse train. 
         [0029]    Preferentially, the time between two consecutive light intensity maxima is between 100 ms and 300 ms. 
         [0030]    In an exemplary implementation of the invention, the light device is arranged to fulfill a predetermined regulatory photometric function such as road lighting, dipped lighting, a daytime running light (DRL), a position light, fog lighting. 
         [0031]    The modulated light signal corresponds, in this case, to the modulation, for example in light intensity, of the predetermined photometric function. 
         [0032]    If desired, the light signal is modulated so as to reach light intensity values greater than the nominal light intensity value of the associated photometric function. 
         [0033]    Advantageously, the photometric function associated with the light device corresponds to a road lighting. 
         [0034]    In another exemplary implementation of the invention, the light device is arranged so as to participate only in the emission of the modulated light signal, without producing any regulatory photometric function. 
         [0035]    In an exemplary implementation of the invention, the modulated light signal has a maximum intensity that is high enough for the modulated light signal to be able to be differentiated from the ambient brightness and low enough not to be a nuisance to a person in the vicinity of the emitting vehicle. 
         [0036]    The maximum intensity of the modulated light signal is preferentially high enough for this signal to be able to be differentiated from the regulatory photometric functions of the vehicle. 
         [0037]    In an exemplary implementation of the invention, the automatic modulation of the light signal is generated by the light device, without the help of any mobile mechanism. 
         [0038]    For example, the modulation of the light signal is generated electronically, notably using a microcontroller or a computer driver. 
         [0039]    In another exemplary implementation of the invention, the modulated light signal is arranged to be imperceptible to the human eye. 
         [0040]    For example, the light signal is modulated according to a frequency that is high enough to make the variations of its intensity invisible to the human eye. 
         [0041]    If appropriate, the amplitude variations of the light signal are low enough for them to be imperceptible to the human eye. 
         [0042]    If desired, the modulated light signal has a wavelength outside the visible domain of the light spectrum. 
         [0043]    If appropriate, the target of the communication includes at least one photosensitive electronic sensor, capable of receiving the modulated light signal. 
         [0044]    In an exemplary implementation of the invention, the target of the communication is a third-party vehicle, notably situated in the vicinity of the emitting vehicle. 
         [0045]    In another exemplary implementation of the invention, the target of the communication is a fixed installation, such as a terminal or a relay, for example, installed on the side of a road. 
         [0046]    If desired, the emitting vehicle includes a photosensitive electronic sensor arranged to receive a modulated light signal emitted, for a communication, by a light device of a third-party vehicle or of a fixed installation. 
         [0047]    If appropriate, the communication is both uplink and downlink, the emitting vehicle and the target being both emitter and receiver. 
         [0048]    Advantageously, the modulated light signal is arranged to carry at least one information item, notably binary, and the photosensitive electronic sensor of the target is linked to a processing unit capable of processing this information item. 
         [0049]    For example, the information item carried by the modulated light signal relates: 
         [0050]    to the environment of the emitting vehicle, for example to the traffic condition around the emitting vehicle or to climatic conditions; 
         [0051]    to the state of the emitting vehicle, for example a failure state of the vehicle; and 
         [0052]    to a message, for example a personal message. 
         [0053]    In an exemplary implementation of the invention, the emission of the modulated light signal is triggered by a manual control device, that is to say, a device that can be controlled by a person. A manual control device may, if appropriate, signify a device that can be controlled by the voice of a person. 
         [0054]    The manual control device may be a device internal to the vehicle chosen from the following nonlimiting list: 
         [0055]    a pedal; 
         [0056]    a hand lever; 
         [0057]    a knob; 
         [0058]    a handle; 
         [0059]    a lever; 
         [0060]    a slider; 
         [0061]    a control wheel; and 
         [0062]    a touch screen. 
         [0063]    In another exemplary implementation of the invention, the control device may be external to the vehicle and chosen from the following nonlimiting list: 
         [0064]    a remote control; 
         [0065]    a telephone; 
         [0066]    a PDA/smartphone; and 
         [0067]    a computer. 
         [0068]    In another exemplary implementation of the invention, the emission of the modulated light signal is triggered by an automatic control device. 
         [0069]    If appropriate, the automatic control device is arranged to process an information item concerning the environment of the vehicle, such as, for example, the presence of an accident on the road. 
         [0070]    This information concerning the environment of the vehicle may be obtained by an acquisition device, chosen for example from the following nonlimiting list: 
         [0071]    a sensor such as, for example, a CCD; 
         [0072]    an infrared detector; 
         [0073]    one or more photodiodes; 
         [0074]    a geolocation system; 
         [0075]    an accelerometer; 
         [0076]    a vehicle speed measurement system; 
         [0077]    a goniometer; and 
         [0078]    an LED. 
         [0079]    The subject of the invention is also a system for communication between an emitting motor vehicle and a target, this system comprising: 
         [0080]    at least one light device; and 
         [0081]    a modulation device for automatically modulating the light signal emitted by the light device for a communication between the vehicle and the target. 
         [0082]    The invention can be better understood from reading the following detailed description of nonlimiting exemplary implementations of the invention, and from studying the appended drawing, in which: 
     
    
     
       BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS 
         [0083]      FIG. 1  schematically and partially represents a communication system according to an exemplary implementation of the invention; 
           [0084]      FIG. 2  schematically and partially represents a timing diagram of a light signal emitted within the system of  FIG. 1 ; 
           [0085]      FIG. 3  schematically and partially represents a timing diagram of a light signal emitted in extra-intensity mode within the system of  FIG. 1 ; 
           [0086]      FIG. 4  schematically and partially represents a communication system using binary data, according to another exemplary implementation of the invention; 
           [0087]      FIG. 5  schematically and partially represents a timing diagram of a light signal emitted in the system of  FIG. 4 ; 
           [0088]      FIG. 6  schematically and partially represents an emitter-receiver communication system according to another exemplary implementation of the invention; and 
           [0089]      FIGS. 7 ,  8  and  9  schematically and partially represent various control devices of a communication system according to exemplary implementations of the invention 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0090]      FIG. 1  represents a communication system  1  according to an exemplary implementation of the invention, this system  1  being mounted on an emitting vehicle Ve and enabling communication between the emitting vehicle Ve and a target  4 . 
         [0091]    This system  1  comprises: 
         [0092]    a light device  2 , capable of emitting a light signal S; and 
         [0093]    a modulation device  3 , for automatically modulating the light signal S. 
         [0094]    The target  4  is, in the example described, a road user, for example a pedestrian or a driver of another vehicle. 
         [0095]    The light device  2  comprises at least one LED  100 . 
         [0096]    This light device  2  is arranged to produce a regulatory ‘road lighting’ photometric function. 
         [0097]    The automatic modulation device  3  is, for example, a microcontroller or a driver. 
         [0098]    The automatic modulation device  3  makes it possible to modulate a light signal emitted by the light device  2  in the manner described in  FIG. 2 . 
         [0099]    As can be seen, the modulated light signal S comprises a train T of periodic light pulses, comprising, for example, 9 pulses, the period of the pulses of the train T being, for example, equal to 200 ms. 
         [0100]    The maximum light intensity of the modulated light signal, in the example described, is substantially equal to that of the ‘road lighting’ function produced by the light device  3 . 
         [0101]    As a variant, as can be seen in  FIG. 3 , the maximum intensity of the light signal is greater than that of the ‘road lighting’ function. 
         [0102]    For example, this maximum intensity is equal to 1.5 times that of the ‘road lighting’ function. 
         [0103]    In the example that has just been described, the communication system  1  makes it possible to produce a signal headlight call S by automatically modulating the road lighting. 
         [0104]      FIG. 4  represents a first communication system  51 , mounted on an emitting vehicle Ve, and a second communication system  52 , mounted on a target  4 , according to another exemplary implementation of the invention. 
         [0105]    The systems  51  and  52  allow communication between the emitting vehicle Ve and the target  4 . 
         [0106]    In the example described, the target  4  is a third-party vehicle or a fixed installation. 
         [0107]    The first communication system  51  comprises: 
         [0108]    a light device  2 , capable of emitting a light signal S; 
         [0109]    a modulation device  3 , for automatically modulating the light signal S; and 
         [0110]    a control unit  10 , linked to the modulation device  3 . 
         [0111]    The light device  2  comprises at least one LED, not represented here. 
         [0112]    The light device  2  is arranged to produce a modulated light signal S whose optical characteristics differ from any regulatory photometric function. 
         [0113]    The wavelength of the light signal S is outside the visible spectrum of light, making this signal S imperceptible to the human eye. 
         [0114]    The control unit  10  is arranged to generate binary information relating to the environment of the emitting vehicle, such as, for example, the road traffic condition, intended for the target  4 . 
         [0115]    The second communication system  52  comprises:
       a photosensitive electronic sensor  6 , capable of receiving the modulated light signal S; and       
 
         [0117]    a processing unit  7 , linked to the sensor  6 . 
         [0118]    The photosensitive electronic sensor  6  is, for example, a camera or a photodiode  6 . 
         [0119]    The processing unit  7  is arranged to process the modulated light signal S in order to decode the information generated by the control unit  10  of the emitting vehicle Ve. 
         [0120]    This processing unit  7  is, for example, a demodulator associated with a decoder. 
         [0121]    The automatic modulation device  3  modulates a light signal emitted by the light device  2 , according to the binary information produced by the control unit  10 , in the manner described in  FIG. 5 . 
         [0122]    As can be seen in this figure, the modulated light signal S comprises a train of light pulses. 
         [0123]    The modulation is paced at a frequency that is high enough, for example approximately 1000 Hz, to make it imperceptible to the human eye. 
         [0124]    In the example described, the modulation used is an all-or-nothing modulation, also called ‘On-Off Keying’, in which each information bit generated by the control unit  10  is transmitted without being coded. 
         [0125]    As a variant, other modulations may be used, in conjunction with correcting or compressing coding units. 
         [0126]    In the example that has just been described, the communication systems  51  and  52  make it possible to transmit the binary information by automatically modulating a light signal emitted by the emitting vehicle Ve. 
         [0127]      FIG. 6  represents a communication system  13  mounted on a vehicle Ve, according to another exemplary implementation of the invention. 
         [0128]    The communication system  13  allows for an uplink communication between the vehicle Ve and a target  4  and a downlink communication between the vehicle Ve and the third-party emitter  9 . 
         [0129]    The communication system  13  comprises: 
         [0130]    a light device  8 , capable of emitting a light signal S 1  and of receiving a light signal S 2 ; 
         [0131]    a modulation device  3 , for automatically modulating the light signal S 1 ; and 
         [0132]    a processing unit  11  linked to the modulation device  3 . 
         [0133]    In the example described, the third-party emitter  9  and/or the target  4  are mounted on third-party vehicles or fixed installations. 
         [0134]    The third-party emitter  9  is capable of emitting a modulated light signal S 2 , carrying an information item intended for the emitting vehicle Ve. 
         [0135]    The light device  8  comprises at least one LED, not represented here, and at least one photosensitive electronic sensor  101 , for receiving the signal S 2 . 
         [0136]    The light device  8  may be arranged to produce a modulated light signal S 1  whose optical characteristics differ from any regulatory photometric function. 
         [0137]    The wavelength of the light signal S 1  may be outside the visible spectrum of light, making this signal S 1  imperceptible to the human eye. 
         [0138]    The processing unit  11  is arranged to: 
         [0139]    generate binary information relating to the environment of the emitting vehicle, such as, for example, the road traffic condition, intended for the target  4 ; and 
         [0140]    processing the modulated light signal S 2  received in order to decode the information transmitted by the third-party emitter  9 . 
         [0141]    This processing unit  11  is, for example, a coder/decoder. 
         [0142]    In the example that has just been described, the communication system  13  enables binary information to be transmitted to a target  4  by automatically modulating a light signal emitted by the emitting vehicle Ve and/or binary information transmitted by a third-party emitter  9  to be received and processed. 
         [0143]    Advantageously, the target  4  and the third-party emitter  9  are incorporated in one and the same communication system, this communication system being, for example, mounted on another vehicle. 
         [0144]    The invention therefore allows, in this case, an uplink and downlink communication between the two vehicles in order to improve driving and road safety. 
         [0145]      FIG. 7  represents a communication system  14  mounted on a vehicle Ve, according to another exemplary implementation of the invention. 
         [0146]    The system  14  allows for a manually triggered communication, between the emitting vehicle Ve and the target  4 . 
         [0147]    In the example described, the target  4  is a third-party vehicle or a fixed installation. 
         [0148]    The communication system  14  comprises: 
         [0149]    a light device  2 , capable of emitting a light signal S; 
         [0150]    a modulation device  3 , for automatically modulating the light signal S; and 
         [0151]    a manual control device, mounted in the passenger compartment of the emitting vehicle Ve. 
         [0152]    The manual control device is chosen from the following list: a button  18 , a hand lever  15 , pedals  16 , a lever  17  or a control wheel  19 . 
         [0153]    The emission of the modulated light signal S is triggered as soon as the manual control device is activated. 
         [0154]    In the example that has just been described, the communication system  14  allows for an automatic headlight call to be made, manually triggered, for example when a dedicated button is activated. 
         [0155]    The invention is not limited to the manual control devices described above. 
         [0156]    For example,  FIG. 8  represents a communication system  22  mounted on an emitting vehicle Ve. 
         [0157]    This communication system  22  is identical to the communication system  14  represented in  FIG. 7 , apart from the fact that the manual control device  20  is hand-held and that a signal acquisition device  21  is provided in the emitting vehicle Ve. 
         [0158]    The manual control device  20  is, for example, a remote control  20 , which can be used to remotely open the doors of the emitting vehicle Ve. 
         [0159]    The signal acquisition device  21  is capable of receiving a signal from the manual control device  20  and thus of triggering, upon the detection of this signal, the emission of the modulated light signal S. 
         [0160]    This makes it possible, for example, for the owner of the vehicle to easily identify his vehicle, for example in a car park. 
         [0161]    In the example that has just been described, the communication system  22  can be triggered from outside the passenger compartment of the vehicle Ve. 
         [0162]      FIG. 9  represents a communication system  25  mounted on an emitting vehicle Ve, according to another exemplary embodiment of the invention. 
         [0163]    The communication system  25  is identical to the communication system  14  represented in  FIG. 7 , apart from the fact that the associated control device is automatic. 
         [0164]    The automatic control device is arranged to process information concerning the environment of the vehicle, such as, for example, the presence of an accident on the road. 
         [0165]    This information concerning the environment of the vehicle may be obtained by an acquisition device, such as a geolocation system  23  or a camera  22 . 
         [0166]    While the method herein described, and the form of apparatus for carrying this method into effect, constitute preferred embodiments of this invention, it is to be understood that the invention is not limited to this precise method and form of apparatus, and that changes may be made in either without departing from the scope of the invention, which is defined in the appended claims.