Abstract:
A detection method, system and device for a motor vehicle (V 1 ). The method system and device uses at least one camera which has a predetermined field of vision. The method includes the following steps:
       receiving information which is representative of a driving state associated with the vehicle; and   modifying the field of vision of the camera, and in particular its orientation, according to the information.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to French Application No. 1050433 filed Jan. 22, 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 in particular to a detection method for a motor vehicle. 
         [0004]    2. Description of the Related Art 
         [0005]    In the field of driving assistance, a plurality of functions have arisen. These require as sensors cameras which can analyze the scene, and these functions thus provide assistance in making a decision, or permit automation of certain tasks which had hitherto been the responsibility of the driver of the vehicle. 
         [0006]    Reference can be made for example, non-exhaustively, to the automation of the high-beam/low-beam function, parking assistance functions, adaptive lighting functions, and detection of lines on the ground. 
         [0007]    In these different cases, and for each application, the field of vision of the camera is adapted to the situation. 
         [0008]    However, in view of the increasing concern for reduction of costs, and for standardization, motor vehicle manufacturers would like the sensors to be in common. This multi-functionality involves compromises in terms of the field of vision. The field of vision selected is the best compromise between the needs of each application. 
         [0009]    This compromise may not eliminate all the contradictions, and some functions are then downgraded in terms of performance. 
         [0010]    In addition, the solution to some functions has now been found in the form of use of specific sensors (for example: the front side view application provided by a front corner camera). 
         [0011]    Also in a concern for reduction of the costs, it is advantageous to propose solutions for this type of application which would use existing sensors, i.e., which already carry out other functions in the vehicle. 
         [0012]    Finally, some functions still do not have technical solutions, or have weaknesses which can be improved. 
         [0013]    A headlight which is fitted such as to rotate around a vertical axis is also known from patent FR 2 899 967, which is equivalent to U.S. Pat. No. 7,595,634, which is incorporated herein by reference and made a part hereof. 
         [0014]    What is needed, therefore, is an improved system and method for detection which improves driving of the vehicle. 
       SUMMARY OF THE INVENTION 
       [0015]    One object of the present invention is in particular to respond to the various above-described needs, for example, by putting several items of equipment of the vehicle in common. 
         [0016]    Another object of the invention is in particular a detection method for a motor vehicle, this method using at least one camera which has a field of vision, this method comprising the following steps:
       receiving information which is representative of a driving state associated with the vehicle; and   modifying, preferably automatically, a field of vision of the camera, and in particular its orientation, according to the information.       
 
         [0019]    The field of vision of the camera can be formed by a solid angle (or cone of perception) defined by the orientation of an optical axis of the camera and its viewing angle. 
         [0020]    The field of vision defines in particular the target space of the camera, i.e., the area of perception of the camera. 
         [0021]    A base of the solid angle can be for example rectangular. 
         [0022]    According to an embodiment of the invention, information which is representative of a driving state associated with the vehicle is selected from amongst: vehicle cornering information, information on the type of environment of the vehicle (this type of environment being able to be for example urban, i.e., the vehicle is in a town, or rural, i.e., the vehicle is in the countryside), information about conditions of climate or brightness, or information about control of a flashing light of the vehicle. 
         [0023]    If applicable, the information which is representative of a driving state associated with the vehicle is cornering information about the vehicle, selected from an angle on the vehicle steering wheel, or location data of the vehicle, such as GPS data. 
         [0024]    Advantageously, the vehicle comprises a headlight which can emit a light beam, the orientation of which can be modified in order to follow a bend, and the orientation of the field of vision of the camera is modified according to the modification of the orientation of the beam of the headlight when at a bend. 
         [0025]    If required, the camera is mobile simultaneously with displacement of the headlight, this displacement comprising, for example, of pivoting. 
         [0026]    The headlight can be associated with a DBL device, in order to displace the beam at a bend, and the camera can be associated with the DBL device, whilst, for example, being fitted on this DBL device, or being physically connected to this DBL device. 
         [0027]    According to an embodiment of the invention, the camera is fitted on an independent platform of the vehicle headlights, this platform being designed to permit movement of the camera relative to the vehicle. This platform is, for example, secured to the vehicle windscreen. 
         [0028]    If applicable the information which is representative of a driving state associated with the vehicle is information about the speed of the vehicle, or information about the brightness of the environment. 
         [0029]    Advantageously, the field of vision of the camera is modified, in particular its orientation, when the speed of the vehicle is below a predetermined threshold, in particular in order to widen visibility on one side of the road at least. 
         [0030]    For example, at least two cameras are provided, and, when the speed of the vehicle is below a predetermined threshold, the orientation of the cameras is modified so that the respective fields of vision move apart from one another in order to widen visibility on both sides of the vehicle. 
         [0031]    If applicable, the field of vision of the camera is modified when the vehicle location information indicates the presence of a complex urban environment around the vehicle, in particular in order to widen visibility on one side of the road at least. 
         [0032]    If required, the angular clearance permitted by the camera is between 0 and 15° or between 0 and 30°. 
         [0033]    Still another object of the invention is also a detection device for a motor vehicle, this device comprising at least one camera which has a field of vision, this device being designed to:
       receive information which is representative of a driving state associated with the vehicle; and   modify the field of vision of the camera, in particular its orientation, according to the information.       
 
         [0036]    Advantageously, the device comprises a DBL device which is associated with a headlight of a vehicle, the camera being coupled kinematically to the DBL device. 
     
    
     
       BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS 
         [0037]    The invention will be able to be better understood by reading the following detailed description of non-limiting embodiments of it, and by examining the attached drawing, in which: 
           [0038]      FIG. 1A  represents, schematically and partially, the situation on the road of a vehicle which is equipped with a camera according to the prior art, without a rotary headlight; 
           [0039]      FIG. 1B  represents, schematically and partially, the situation on the road of a vehicle which is equipped with a camera according to the prior art, with rotary headlights or DBLs; 
           [0040]      FIG. 1C  represents, schematically and partially, the situation on the road of a vehicle which is equipped with a detection device according to the invention, with rotary headlights or DBLs; 
           [0041]      FIGS. 2 and 3  represent, schematically and partially, in perspective, devices according to two embodiments of the invention; and 
           [0042]      FIG. 4  represents, schematically and partially, a situation on an urban road of a vehicle which is equipped with a device according to another embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Night-time Context 
       [0043]    An application specific to night-time is known, which consists of automation of the lighting, that is, an application which makes it possible to tilt from the low-beam light to the high-beam light or vice versa, according to vehicles which are potentially arriving opposite and which vehicles are detected automatically by a camera. 
         [0044]    In certain cases of very tight bends, it has been shown that vehicles VI which are passing the vehicle V 1  which is equipped with the lighting automation function can be in the high beam Fr of the headlights of V 1 , and not be in the field of vision  1  of the camera  40  for a very short period of time (see  FIG. 1A ). 
         [0045]    The vehicles VI are in a situation of potentially being dazzled, which is reinforced by the action of a DBL (Dynamic Bending Light) device, as illustrated in  FIG. 1B . 
         [0046]    In this example in  FIG. 1B , the camera is fixed, that is, it cannot pivot relative to the vehicle. 
         [0047]    In contrast to  FIGS. 1A and 1B , the DBL device in a motor vehicle headlight of the embodiment shown in FIGS.  1 C and  2 - 3  makes it possible to make an optical module pivot within the headlight. 
         [0048]    The optical module can be of a low-beam light type and can pivot according to the trajectory which is being followed by the vehicle, in particular when the latter is cornering, in order to obtain a so-called “bending beam” or DBL. 
         [0049]    Association of the movement of the camera with that of the DBL device reduces this risk of dazzling (as illustrated in  FIG. 1C ). 
         [0050]    According to all of the functions which are present in the vehicle V 1 , and in a non-limiting manner, a single camera is situated in the headlight on the passenger side or on the driver&#39;s side or two cameras are placed each in a headlight, or the camera is placed at the top of a windscreen W ( FIG. 4 ) on a platform. 
         [0051]    In the case of one or more cameras which are placed in the headlights, the cameras can be fitted directly on the DBL device or can be physically connected to this device, as will be seen in greater detail hereinafter with reference to  FIGS. 2 and 3 . 
         [0052]    In the case of a camera at the top of the windscreen W, the movement of the camera is created by another platform which acquires information from the DBL device, or obtains directly the information concerning the steering wheel angle, which information controls the DBL device. 
         [0053]    In general, all the information which is necessary for control of the movement of the DBL device, as well as the laws which govern this information, can be acquired by this platform. 
         [0054]    In order to reduce the costs, it is possible to give precedence to implantation in the headlight(s), so as to benefit from the existing mechanical movement platforms. 
         [0055]    Hereinafter in the description, there will be adoption on a non-limiting basis of a longitudinal, vertical and transverse orientation which is fixed relative to the motor vehicle bodywork, and is indicated by the trihedron L, V, and T in  FIG. 2 . 
         [0056]      FIG. 2  shows a motor vehicle headlight  10  which in this case comprises a reflector  12 , inside which a lamp  14  is fitted. The headlight  10  can emit a light beam according to an optical axis O with a globally longitudinal orientation. 
         [0057]    The reflector  12  and the lamp  14  form an optical module  15 . 
         [0058]    The module  15  is fitted such as to rotate around a vertical axis A, relative to the bodywork  16  of the motor vehicle. For this purpose, the headlight  10  comprises, for example, two lower and upper journals  18  with the axis A. 
         [0059]    The beam of the headlight  10  can thus be oriented according to a plurality of angular positions around the axis A, in a clearance interval which is delimited by two end angular positions. 
         [0060]    Hereinafter in the description, a neutral angular position is defined, which corresponds to the angular position which the headlight  10  occupies when it lights the road according to the longitudinal axis L of the vehicle. 
         [0061]    The neutral angular position occupies a median position in the clearance interval. 
         [0062]    Thus, the optical axis O of the beam of the headlight  10  can pivot on both sides of the longitudinal axis L of the motor vehicle. 
         [0063]    The headlight  10  is rotated by a DBL drive device  20 , which in this case comprises an electric motor  22 , for example a step-by-step or stepper motor, which comprises a rotary vertical shaft  24 . The motor  22  is fitted fixed relative to the bodywork  16  of the motor vehicle. A pinion  26  is provided at a free upper end of the shaft  24 . 
         [0064]    The DBL drive device  20  also comprises a circular toothed sector  28  which extends on a horizontal plane in the form of a fan, from a top  29  to a toothed peripheral arc  31 , with a top  29  forming a center of a peripheral arc  31 . 
         [0065]    A top  29  of the toothed sector  28  is fitted such as to rotate around the axis A, such that a toothed sector  28  is integral in rotation with the headlight  10 . The teeth  31  of the toothed sector  28  are engaged with the teeth of a pinion  26 , such that the motor  22  can rotate the headlight  10  by means of the toothed sector  28 . 
         [0066]    The DBL drive device  20  optionally also comprises a printed circuit board  30 , which extends on a transverse vertical plane, and in this case is secured to the motor  22 . 
         [0067]    If required, the drive device  20  comprises at least two Hall-effect sensors which are provided on the printed circuit board  30 . 
         [0068]    With reference to the role of the sensors which make it possible to measure the angular position of the headlight beam in its clearance interval, reference can be made to patent FR 2 899 967, which is equivalent to U.S. Pat. No. 7,595,634, which is incorporated herein by reference and made a part hereof. 
         [0069]    In the example in  FIG. 2 , the camera  40  is placed in the headlight  10 , and is fitted directly on the DBL device  20 , for example, integrally with the axis of pivoting A of the lighting module. 
         [0070]    As a variant, as illustrated in  FIG. 3 , the camera  40  is placed in the headlight  10 , and is physically connected to the DBL device  40 , for example, by means of a toothed sector  41  that can rotate around an axis B, which, for example, is parallel to the axis A. 
       Town/Low Speed 
       [0071]    Within the context of driving in town, both by day and by night, the cameras which are coupled to the DBL device can also be used in order to improve the visibility at low speed when vehicles are passing one another. In fact, when approaching narrow crossroads, in town, it happens frequently that there is no visibility to the left and/or to the right. In the case for example of driving on a narrow road in town, the buildings which are on the right or the left of the road can make the visibility difficult at the approach to a crossing, as shown in  FIG. 4 . 
         [0072]    The invention thus proposes to orient the cameras  40 , in particular in the right and left headlights, by means of the DBL device, in order to widen the visibility on both sides of the crossing. 
         [0073]    As soon as the vehicle is in town at low speed (information available in the vehicle, or speed information, or GPS information for example), the DBL devices can automatically be oriented towards the exterior, in order to widen the field of visibility. In town, at low speed, since the need for lighting is less great than on the road in the countryside (because of the exterior lighting), the fact of moving the light beams apart does not cause any problem. 
         [0074]    It will be appreciated that, in order to be more efficient, this device requires putting into place of a machine interface, which makes it possible to inform the driver of the presence of an obstacle or a vehicle. A display screen in the vehicle can be an appropriate interface for providing the driver with this information. The two images (left and right cameras) can be coupled to the same screen. 
         [0075]    The camera is advantageously associated with the movement of the DBL device, in order to follow the beam at night, or to increase the cover of visibility of the cameras by day. 
         [0076]    The night-time and daytime functions can be made compatible. 
         [0077]    It will be appreciated that the invention is not limited to the above-described embodiments. 
         [0078]    For example, the mobility of the light beam can be assured by use of an FBL (Fixed Bending Light) device. 
         [0079]    In this case, there is no movement which is specific to the headlight. 
         [0080]    In a non-limiting manner, the beam can be modified in its orientation and form by the successive activation or deactivation of different sources of light (which can for example be LEDs), or by movement inside the headlight (for example movement of a shield which is mobile inside the headlight). 
         [0081]    In this case, the movement of the camera can be controlled by information concerning activation of the FBL (for example information concerning the angle on the steering wheel, or GPS data). 
         [0082]    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.