Abstract:
The present invention relates to produce a display of the environment of the aircraft by combining live shooting by replacing a window with a camera lens and an illumination of this environment in suitable radiation ranges, connected with a display. According to the invention, a system for displaying the environment of an aircraft includes in a door ( 4, 4   i   , 10 ) provided with a locking and opening system ( 41, 42, 6 ), at least one illumination source ( 7 ) illuminating areas of the environment in at least one radiation range, at least one video camera ( 1   a,    1   b ) provided with a lens capable of capturing the external environment illuminated by the source in order to provide a video signal, and at least one display screen ( 8 ) connected with the camera ( 1   a,    1   b ) for receiving the video signal. The camera ( 1   a,    1   b ), the illumination source ( 7 ) and the display screen ( 8 ) are linked to a calculation unit ( 5 ) capable of receiving information concerning the state of operation of the aircraft equipment and display parameters of the environment.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application is a national stage entry of PCT/EP2014/057223 filed Apr. 10, 2014, under the International Convention claiming priority over French Patent Application No. 1353323 filed Apr. 12, 2013. 
       TECHNICAL FIELD OF THE INVENTION 
       [0002]    The invention relates to a method and a system suitable for providing a display inside an airplane of the external environment of that airplane, and an airplane door equipped with this display system. 
         [0003]    In emergency situations in which the passengers have to be evacuated to the ground, for example in the event of an airplane fire, it is known practice to use escape slides which are moored to the emergency exit doors or fuselage of the airplane. In order to ensure that the external conditions of the airplane make it possible to deploy the escape slide in total safety, a direct view of the immediate environment of the airplane is conventionally produced through a window by the crew of the airplane, an air hostess or an in-charge flight attendant. 
         [0004]    Furthermore, the view of the environment close to the airplane is useful to avoid collisions on the ground, particularly at the wing ends when the airplane is pulled in reverse, for example in a parking zone, in a hanger for an overhaul or during maintenance. 
         [0005]    Generally, a view of the environment of the airplane makes it possible to monitor the approaches and anticipate certain risks or avoid hazardous situations: for example when taxiing on the taxiways, notably at intersections thereof, or when two airplanes cross on the same taxiway, when obstacles are present on the runway, objects or vehicles are present nearby, the environment is suspect, etc. 
       STATE OF THE ART  
       [0006]    The size of a window dedicated to the external view results from a trade-off between the constraints associated with the placement of this window in a door or the fuselage of the airplane and the aperture of the field of view which results from this size. 
         [0007]    It is also known practice, for example from the patent document GB 1290144, to use a camera to film objects outside of an airplane through a window. In order to pick up the field outside the direct view axis, a prism provided with a 45° inclined reflecting surface can be used between the window and the camera. In order to increase the aperture of the observed field, the input and output surfaces of the prism are curved. 
         [0008]    To observe the presence of ice or the presence of foreign bodies on the wings of an airplane, U.S. Pat. No. 6,052,056 describes also the transmission of a pulsed light to an optical sensor via an optical channel. When water, ice or a de-icing liquid covers the sensor, a variable quantity of pulsed light is reflected and strikes a photosensitive detector—for example photodiodes—after having returned through the optical channel. The photodiodes then provide a signal which varies as a function of the type of detection, in terms of nature and quantity. 
         [0009]    These documents do not make it possible to address the problem of the display of the space which surrounds the airplane with a degree that is sufficient to provide a guarantee of observation (day/night display, poor weather conditions, etc.) both of the immediate environment of the airplane—in particular to accurately check the impact on the ground of the escape slides when they are deployed—and of the environment of the wing ends in order to be able to rectify the trajectory of the airplane in time in case of a risk of collision. 
       SUMMARY OF THE INVENTION 
       [0010]    The invention aims to produce such a display of the environment of the airplane by combining a direct shot and illumination in light radiation ranges appropriate to this environment, in conjunction with a display suitable for providing immediately usable information. 
         [0011]    To this end, the object of the present invention is a method for displaying the external environment of an airplane and consisting in replacing a window of the airplane by at least one opening produced in at least one door of the airplane, in mechanically coupling a lens of a camera for transmitting a video signal in this opening, such that the lens directly picks up the light originating from said environment of the airplane. This environment is previously illuminated by zone with a directional lighting in at least one radiation range chosen as a function of display parameters of this environment. The method then consists in transmitting the video signal supplied by the camera(s) to at least one display screen to provide comprehensive information from this signal. The comprehensive information relates to the state of operation of the equipment of the airplane, and to the display of safety zones surrounding the airplane whose lighting is adjusted as a function of said parameters. 
         [0012]    Advantageously, the camera associated with the lighting makes it possible to measure the weather conditions over the visual range RVR (Runway Visual Range) of the pilot, particularly by targeting the end winglets in order to measure the RVR automatically and local to the airplane. 
         [0013]    According to preferred embodiments: 
         [0014]    the lighting parameters are set, between the infrared or visible radiation range, as a function of the weather conditions (day/night; poor conditions: mist, rain, etc.) of the environment and of the specific state of orientation of the airplane as established by a piloting center with which the airplane is equipped; 
         [0015]    the radiation range is situated in the visible radiation spectrum when the solar radiation is above a determined threshold, particularly during the day, and the lighting is directed toward at least one passenger evacuation zone to guide the passengers and/or a zone surrounding the door(s) in order to facilitate maintenance activities; 
         [0016]    the radiation range is situated in the near IR (infrared) radiation in order to provide a usable display when the solar radiation is below a determined threshold, in particular at night; 
         [0017]    at least one double opening is produced in at least one door of the airplane, each opening being mechanically coupled to a camera lens so as to perform at least one video processing in three dimensions (3D) or enhanced 2D; 
         [0018]    the 3D display is produced through each front door and each rear door of the airplane, to assess the position of the wing ends on the ground respectively when the aircraft moves forward and when the aircraft reverses, the distance relative to an obstacle, or another assessment relative to the environment of the airplane; 
         [0019]    the video signal can also be transmitted to a display screen installed in the piloting cockpit of the airplane and/or to the screens of a video system with which the passenger cabin is equipped, this video signal being able to be accompanied by complementary information (assessment of the distances to the obstacles, recognition of forms, etc.); 
         [0020]    the screen or screens also displays/display information and/or alert messages linked to the state of operation of the equipment of the airplane, in particular the status of the door(s) (for example: locked, blocked or closed), the state of the escape slide arming/disarming system (nitrogen tank, etc.), the control mode of the camera and of the illumination (manual or automatic), and the state of the equipment for maintenance (state of the engine, state of the air conditioning system, etc.). 
         [0021]    The invention relates also to a system for displaying the external environment of an airplane comprising a passenger cabin, a cockpit, wings and passenger and service doors, this system being intended to apply the method defined above. Such a system comprises at least one source of illumination for zones of said environment in at least one radiation range, at least one video camera provided with a lens suitable for picking up a set of light rays originating directly from the external environment illuminated by the source to provide a video signal corresponding to said environment, and at least one display screen linked with the camera to receive the video signal. The camera, the illumination source and the display screen are linked to a computation unit suitable for receiving information on the state of operation of the equipment of the airplane and display parameters of said environment. 
         [0022]    According to preferred embodiments: 
         [0023]    at least one illumination zone surrounds an impact zone of the airplane escape slide determined by the computation unit, this zone remaining displayed on the screen by inclusion in the computation unit of the state of orientation of the essential structures of the airplane, for example of the landing gear, of the fuselage and of the engine pods; 
         [0024]    the illumination source or illuminator consists of light-emitting diodes or LEDs for lighting in the visible or infrared radiation range, arranged in a housing to light a zone that is sufficiently wide surrounding the impact zone of an escape slide of an airplane door; 
         [0025]    a 3D display is produced by a pair of cameras through a front door and a rear door of the airplane, to assess the position of the airplane relative to its environment during maneuvers on the ground, in particular to assess the position of the wing ends respectively when the airplane moves forward and when the airplane reverses; 
         [0026]    the video signal can also be transmitted to a display screen installed in the piloting cockpit of the airplane and/or to the screens of a video system with which the passenger cabin is equipped. 
         [0027]    Another subject of the present invention is an airplane door, namely passenger door or service door, comprising a locking system and a door opening/closing system by an articulation arm. This door is equipped with the display system defined above comprising at least one HD video camera. 
         [0028]    Preferably, the computation unit of the display system is also intended to drive and coordinate the movements of the articulation arm of the door via an assisted mechanical drive or an electric drive motor. 
         [0029]    Advantageously, the illuminator consists of an LED lighting assembly, advantageously arranged in proximity to the door, and the camera(s) and the display screen are installed on the door, preferably substantially in the middle of the door. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0030]    Other features and advantages of the invention will emerge on reading the following description which relates to an exemplary embodiment, with reference to the attached figures which illustrate: 
           [0031]      FIGS. 1   a  and  1   b , cross-sectional views of two examples of fixing of the lens of a video camera through an airplane door; 
           [0032]      FIG. 2 , a front view of the internal face of an exemplary passenger door equipped with two cameras, an IR/visible illuminator and a display screen; 
           [0033]      FIG. 2   a , a lateral cross-sectional view of the illuminator; 
           [0034]      FIG. 3 , a perspective view of an airplane environment illustrating the range of the light radiation from the illuminator on the impact on the ground of a deployed escape slide; 
           [0035]      FIG. 3   a , a display screen showing the shot taken by the camera with, in particular, the display of the impact zone of the escape slide on the ground, and 
           [0036]      FIGS. 4   a  and  4   b , a top view and a side view of an airplane whose doors are equipped with two 3D display cameras. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0037]    Referring to the cross-sectional view of  FIG. 1   a , the HD (high definition) video camera  1  of an exemplary display system according to the invention comprises a lens  11  and an electronic housing  12  containing a charge coupled photosensitive sensor (CCD) linked with a collector or, alternatively, a CMOS sensor, this photosensitive sensor being coupled to a signal convertor. At the camera output, a cable  13  makes it possible to transmit an HD video signal to a display screen (see  FIG. 2 ). 
         [0038]    The lens  11  is fixed in a circular opening  21  of a passenger door of the airplane (not represented). The opening  21  is produced previously by cutting anticipated for this purpose on the skin of the fuselage  10 . A cylindrical framing  22  of the same material as the skin  10 —here of composite material—is provided to receive the lens  11  clad in a matching ring  14 . Alternatively, the framing can be formed in a different material from that of the skin, for example aluminum. 
         [0039]    The framing  22  has a widened portion  22   a  passed through by rivets  3  for fixing (or other fixing means: screws, etc.) to the skin  10 . The ring  14  and the framing  22  are joined together via a coupling of thread/tapping type or equivalent (snap fitting, seal, etc.). Furthermore, the electronic housing  12  is advantageously fixed to the skin  10  by lateral ties  15 . 
         [0040]    As a variant, as illustrated by  FIG. 1   b  which denotes the elements that are identical or equivalent in  FIG. 1   a  by the same reference symbols, the framing  22  is replaced by a housing  23 . This housing  23  is passed through by a bore  2   a  suitable for housing the lens  11 . The coupling between the lens  11  and the skin  10  is of the same type as the coupling between the lens  11  and the framing  22  of  FIG. 1 . 
         [0041]    Moreover, the housing  23  bears peripherally against the inner face  10   i  of the skin  10  and is fixed to this skin  10  by appropriate screws  25 . An o-ring seal  26  is housed in a space E 1  formed between the housing  23  and the skin  10  to produce a seal-tight link between the housing  23  and the skin  10 . 
         [0042]    Referring to the front view of  FIG. 2 , the inner face  4   i  of an exemplary passenger door  4 , equipped with two cameras  1 A and  1 B, an IR/visible illuminator  7  and a display screen  8 , is illustrated. The structure of the door  4  consists of a skin  10  reinforced by stiffeners  4   r  in the case where—as in the example illustrated the thickness of the door  4  is too thin to ensure sufficient rigidity. In other embodiments, the door of sufficient thickness may be rigid in itself and not require the reinforcement. 
         [0043]    The passenger door  4  comprises a locking system with safety catch  41 , a door opening/closing system by an articulation arm  42 , and a door computation unit  5  intended to drive and coordinate the movements of the door  4 . The computation unit  5  also drives and coordinates the movements of the articulation arm of the door  42  by an electric drive motor  6 . 
         [0044]    This door  4  is equipped with two HD display video cameras  1   a  and  1   b , each camera being arranged in the manner described above through door openings  21 . The cameras and the display screen are installed substantially in the middle of the door, the cameras  1   a  and  1   b  under the arm  42  and the screen  8  above the arm  42 . 
         [0045]    The distance between the cameras  1   a  and  1   b  is computed so as to allow the processing of the HD video signals in three-dimensional (3D) mode by the computation unit  5 . Such processing makes it possible to accurately measure the distances between objects, in particular between the ends of the wings and the surrounding structures as explained later in conjunction with  FIG. 4   a.    
         [0046]    The display screen  8  also displays information and/or alert messages in conjunction with the state of operation of the equipment of the airplane, namely: the status of the doors—locked, blocked or closed—, the state of the escape slide arming/disarming system, nitrogen tank level, the control mode of the camera and of the illumination—manual or automatic—and the maintenance (state of the engine, of the roll/pitch detection system, state of operation of the weather sensor) and equivalent. 
         [0047]    An illuminator  7 , consisting of an LED housing  71  and a support bushing  72 , is arranged through the door  4 , as shown by the lateral cross-sectional view of  FIG. 2   a . The support bushing  72  is of cylindrical form to be fitted and fixed in a corresponding opening formed in the skin  10  of the door  4 , in a manner similar to the camera lens. 
         [0048]    The LED housing  71  forms a directional lighting part through the presence of a cover with variable angular aperture  73  which channels the radiation toward a zone of the external environment. This part  71  is coupled to the support bushing  72 . 
         [0049]    The illuminator  7  is arranged in the door  4  ( FIG. 2 ). The LEDs can operate in two lighting radiation ranges, covering the visible range and the IR range. The roll/pitch data are supplied to the computation unit from a piloting center through appropriate cabling in order to retain the framing of the escape slide impact zone (see below). The computation unit  5  automatically activates the radiation of the lighting in the infrared range—as long as the airplane is moving on the ground (to allow the crew to correctly display the external conditions)—then in the visible as soon as the door is open (to light the escape path for the passengers on the escape slide). 
         [0050]      FIG. 3  more specifically illustrates an airplane environment  100  when an escape slide  9  is deployed for an evacuation of the passengers from the door  4 . The range of the illuminator  7  makes it possible to light an evacuation zone  91  that is sufficiently wide to surround the impact zone on the ground  101  of the escape slide  9 . 
         [0051]    The illuminated zone  91  makes it possible to target the impact zone  101  and retain the display  101   a  of this zone on the screen  8 , as represented in  FIG. 3   a . On this screen  8 , the image also comprises a dashboard  81  which provides the main safety information: door closure state, cabin pressurization state, external illumination state, escape slide disarming state, etc. 
         [0052]    When the visibility conditions are correct, particularly in daytime, the radiation range of the illuminator  7  is in the visible and the lighting remains directed toward the evacuation zone of the passengers  91  to guide them. Advantageously, a zone surrounding the door  4  is lit by the illuminator  7  in order to facilitate maintenance activities. 
         [0053]    The radiation range is situated in the near IR (infrared) radiation in order to provide a usable display when the visibility conditions of the environment do not allow sufficient visibility in the visible radiation range. Thus, the radiation range is chosen by the computation unit  5  as a function of the display parameters conventionally: sharpness, contrast, brightness—which define the conditions of visibility. 
         [0054]      FIGS. 4   a  and  4   b  respectively illustrate a top view and a side view of the airplane  100  whose doors  4 A to  4 D are each equipped with two high definition (HD) 3D display cameras  1 A and  1 B, each camera being identical to the camera  1  of  FIG. 1 . Thus, as described previously with reference to  FIG. 2 , the lenses  11  of the cameras  1 A,  1 B of a same door are mounted through openings  21  at a distance that makes it possible to produce, by virtue of the computer, the HD 3D display by a processing of the video signals, in order to determine the distances, notably in depth, which would not be possible with a single camera. 
         [0055]    The HD 3D display is thus produced by each pair of cameras  1 A,  1 B through a double opening of each of the front doors  4 A and  4 B and each of the rear doors  4 C and  4 D of the airplane, with wide angular apertures ΔA and ΔB, the rear cameras being directed in the example illustrated so as to be able to also display the wing ends  102  and  103 . The position of the wing ends  102  and  103  is thus assessed on the ground, respectively when the airplane moves forward and when the airplane reverses, through the processing of the video signals by the computation unit  5  ( FIG. 2 ) and provided by the cameras  1 A,  1 B. 
         [0056]    The invention is not limited to the examples described and represented. In particular, the video signal(s) can also be transmitted to a display screen installed in the piloting cockpit of the airplane and/or to the screens of a video system with which the passenger cabin is equipped. 
         [0057]    Furthermore, the 3D display can be useful when the airplane is required to perform more complex maneuvers on the ground, for example when it has to negotiate turns. The use of two cameras per door can also be useful for the airplane transmission in case of failure of the electronic equipment. 
         [0058]    The 3D display can be replaced by a 2D display enhanced by an indication of the depth by a suitable symbol system, for example a color code or equivalent on the display screen. 
         [0059]    Advantageously, the display system according to the invention can be used equally in emergency door opening conditions and in nominal operation, for example to detect the presence of a walkway or of an operator working facing the door. 
         [0060]    Moreover, the screen(s) also displays/display information and/or alert messages in conjunction with the state of operation of the equipment of the airplane chosen from the status of the door(s) (for example: locked, blocked or closed), the status of the escape slide arming/disarming system (nitrogen tank, etc.), the control mode of the camera and of the illumination (manual or automatic) and/or maintenance (state of the engine, of the detection system, etc.).