OPTRONIC EQUIPMENT TO ASSIST THE PILOTING OF AN AIRCRAFT

Description

[0001] The invention relates to optronic equipment for assisting in piloting an aircraft. TECHNOLOGICAL BACKGROUND OF THE INVENTION

[0002] In the military field, aircraft pilot assistance systems called "FLIR" (for Forward Looking InfraRed) are known. These systems usually include a long-wavelength infrared camera (better known by the English acronym LWIR) connected to the pilot's helmet so that a video stream is projected onto his visor from the data provided by the camera, thus allowing him to be able to guide himself at night or in difficult environmental conditions.

[0003] In particular, we know of systems in which the camera can be oriented in elevation and bearing, the orientation of the camera being controlled by the orientation of the pilot's helmet so that the video stream projected onto the helmet visor is linked to the orientation of the helmet.

[0004] However, such a system requires the implementation of sophisticated control between the headset and the camera.

[0005] Over the last ten years, another type of architecture known as "distributed architecture" or "distributed aperture architecture" (better known by its English term Distributed Aperture System) has emerged: the pilot assistance system includes several infrared cameras distributed across the front of the aircraft, the different fields of view of which interfere with each other so that a panoramic strip can be generated from the data provided by the different cameras.

[0006] A view corresponding to the orientation of the pilot's helmet is then extracted from this strip to project the corresponding view onto the helmet visor, thus artificially recreating a camera that can be oriented and controlled by the orientation of the helmet.

[0007] Such a system therefore eliminates the need for complex camera / headset control, but is also multi-user. Indeed, it is possible to extract as many independent views from the panoramic strip as there are users.

[0008] The difficulty with this system lies in creating a large panoramic strip without any noticeable defects. Currently, a large number of cameras and / or heavy and expensive cameras are used.

[0009] Documents US2014 / 0327733 A1 and US 2016 / 0088280 A1 describe prior art documents. SUBJECT OF THE INVENTION

[0010] One aim of the invention is to propose optronic equipment to assist in piloting an aircraft with simplified architecture and distributed pupils. BRIEF DESCRIPTION OF THE INVENTION

[0011] In order to achieve this aim, optronic equipment is proposed for assisting in piloting an aircraft comprising a first set of three cameras, called first camera, second camera and third camera, arranged on the aircraft to generate a panoramic strip from the data transmitted by the three cameras of the first set and a second set of three cameras, called fourth camera, fifth camera and sixth camera, arranged on the aircraft to generate a panoramic strip from the data transmitted by the three cameras of the second set, the cameras being mounted at the front of the aircraft at its nose, three cameras being located to the right of the aircraft's nose and three cameras being located to the left of its nose, the third camera and the fourth camera occupying an end position on the aircraft, with respect to the other four cameras of the first set and the second set, the third camera and the fourth camera being arranged so as to have a larger field of view horizontally than vertically, only the third camera and the fourth camera out of the six cameras of the two sets being arranged so as to have a larger field of view horizontally than vertically, the third camera and the fourth camera framing the other four cameras, the two sets being arranged so that the two strips overlap at least in part so as to provide stereoscopic vision to the pilot.

[0012] In this way, by cleverly rotating at least one of the external cameras in relation to the other cameras, it is possible to increase the field of view in the direction of the panoramic strip without increasing the number of cameras and all the while maintaining a large vertical field of view in the center of the strip.

[0013] This helps to limit the mass and size of the optronic equipment.

[0014] Optionally, at least two contiguous cameras are arranged with a concave arrangement.

[0015] Optionally, the two cameras arranged in the center of the six cameras are crossed so that a first camera of the first set and a first camera of the second set are arranged with a concave arrangement and a second camera of the first set and a second camera of the second set are arranged with a concave arrangement as well.

[0016] Optionally, two cameras belonging to a different set are offset in site relative to each other.

[0017] Advantageously then, the equipment comprises an electronic processing unit connected to the cameras and arranged to display the two image strips in a stereoscopic manner and / or to form at least one wide-field image from the two image strips.

[0018] Optionally, the cameras of the first set are powered by a first power source and the cameras of the second set are powered by a second power source that is independent of the first power source.

[0019] Optionally, the equipment includes at least one block in which the cameras are arranged.

[0020] Optionally, the cameras work in the infrared range.

[0021] Optionally, the cameras are LWIR type.

[0022] Optionally, the cameras are uncooled.

[0023] Preferably, the equipment comprises a processing unit connected to the cameras and to a helmet equipped with an image display device visible to the eyes of the pilot wearing the helmet. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The invention will be better understood in light of the following description of a particular non-limiting embodiment of the invention with reference to the attached figures, among which: there figure 1 is a diagram of optronic equipment according to a particular embodiment of the invention, the figure 2 schematically illustrates the panoramic banner created using the equipment illustrated in figure 1 , there figure 3 is a view similar to that of the figure 2 taking into account the phenomena of distortions and spherical geometry of the fields of view of the equipment's cameras, the figure 4 is a schematic view of part of the equipment illustrated in figure 1 . DETAILED DESCRIPTION OF THE INVENTION

[0025] In reference to the figure 1 , the optronic equipment for assisting in piloting an aircraft according to a first embodiment of the invention comprises a first set 101 of three cameras 111, 112, 113 arranged on the aircraft and a second set 102 of three cameras 114, 115, 116 arranged on the aircraft. Each set strictly comprises three cameras so that the equipment strictly comprises six cameras.

[0026] It is noted that the cameras are mounted on the aircraft without the use of a turret.

[0027] The cameras are for example mounted independently on the aircraft or, on the contrary, the equipment comprises a first block in which three of the cameras are arranged and a second block in which the other three cameras are arranged, allowing the mounting in a single step of three cameras at once on the aircraft. Alternatively, the equipment comprises a single block in which the different cameras of the two sets are arranged, which allows the mounting in a single step of the six cameras at once on the aircraft. The cameras are fixed with respect to the aircraft.

[0028] Cameras are typically mounted at the front of the aircraft at its nose. Here we have three cameras located to the right of the aircraft's nose and three cameras located to the left of its nose.

[0029] Preferably, the cameras 111, 112, 113 of the first set 101 are powered by a first power source and the cameras 114, 115, 116 of the second set 102 are powered by a second power source which is independent of the first power source. In this way, the loss of one of the power sources makes it possible to keep the set which is powered by the other of the two power sources.

[0030] The first set 101 comprises a first camera 111, a second camera 112 and a third camera 113 and the second set 102 comprises a fourth camera 114, a fifth camera 115 and a sixth camera 116. The six cameras are identical here.

[0031] The six cameras are for example infrared. The six cameras are preferably LWIR type. This allows working in the LWIR band which gives better results in the case of degraded flight conditions (night, storm, fog, etc.)

[0032] Preferably, all six cameras are uncooled. This allows for less expensive and more robust cameras.

[0033] In the claimed invention, the first camera 111 and the second camera 112 are arranged so as to have a larger vertical field of view (elevation) than horizontal (bearing), the third camera 113 occupying a lateral end position with respect to the first camera 111 and the second camera 112 being arranged so as to have a larger horizontal field of view than vertical.

[0034] Symmetrically, the fifth camera 115 and the sixth camera 116 are arranged so as to have a larger vertical field of view than a larger horizontal field of view, the fourth camera 114, occupying a lateral end position with respect to the fifth camera 115 and the sixth camera 116, being arranged so as to have a larger horizontal field of view than a larger vertical field of view.

[0035] The third camera 113 and the fourth camera 114 are arranged as far outward as possible from the other four cameras and the longitudinal axis X of the aircraft, i.e. as far away as possible from the longitudinal axis X of the aircraft. The third camera 113 and the fourth camera 114 thus frame the other four cameras.

[0036] In this case, if we place ourselves in the pilot's position, the third camera 113 is located to the left of the longitudinal axis X of the aircraft and the fourth camera 114 to the right.

[0037] In this way, by turning the third camera 113 and the fourth camera 114 90 degrees in slope with respect to the other four, it is very simple to increase the horizontal field of view (i.e. in bearing) of the corresponding panoramic strips that we will describe later and this at the level of lateral vision while maintaining a significant frontal vision in site.

[0038] In order to further improve the dimensions of the panoramic strips, for each set 101, 102, one of the three cameras is frontal (for frontal vision) while the other two are lateral (for vision on the sides). We thus have a camera generally aligned on the longitudinal axis X of the aircraft and two cameras inclined with respect to this axis.

[0039] Preferably, the projection of the line of sight of the front camera in the horizontal plane of the aircraft is parallel to the longitudinal axis X of the aircraft. The lines of sight of the side cameras are inclined with respect to the longitudinal axis X of the aircraft.

[0040] In order to further improve the dimensions of the panoramic strips, the two side cameras of each respective set are oriented so that their respective viewing axes are inclined relative to each other. One of the side cameras of each set thus has its viewing axis oriented to the right and the other of the cameras of the same set has its viewing axis oriented to the left, thus ensuring a view of the right and left sides of the aircraft.

[0041] Typically the second camera 112 and the fifth camera 115 are front-facing and the other four cameras 111, 113, 114, 116 are side-facing.

[0042] Preferably, to limit the blind zones in the panoramic strip, the three cameras 111, 112, 113 of the first set 101 are arranged so that their different fields of view partially overlap at least to infinity. Preferably, this overlap zone is at least between 1 and 5 degrees horizontally, the overlap zone possibly being different for different zones of the first strip.

[0043] In the same way, the three cameras 114, 115, 116 of the second set 102 are arranged so that their different fields of view partially overlap at least to infinity. Preferably, this overlap zone is at least between 1 and 5 degrees horizontally, the overlap zone being able to be different for different zones of the second strip.

[0044] Preferably, the front cameras 112, 115 of the two sets are each arranged in a concave arrangement with at least one of the side cameras of the equipment being contiguous to it.

[0045] This further limits the risk of blind spots, i.e. those not covered by panoramic strips, particularly for short-distance vision.

[0046] In the present case, the two side cameras arranged in the center are crossed so that the first camera 111 of the first set 101 is associated with the fifth front camera 115 of the second set 102 and so that the sixth camera 116 of the second set 102 is associated with the second front camera 112 of the first set 101.

[0047] Typically, the first camera 111 is contiguous to the fifth camera 115 and oriented towards the fifth camera 115. Symmetrically, the sixth camera 116 is contiguous to the second camera 112 and oriented towards the second camera 112.

[0048] Thus the line of sight of the first camera 111 is oriented towards the line of sight of the fifth camera 115 and the line of sight of the sixth camera 116 is oriented towards the line of sight of the second camera 112.

[0049] There figure 4 thus illustrates one of the two blocks of equipment with the second camera 112 and the sixth camera 116 in concave architecture, the third camera 113 also being visible.

[0050] If we look at the pilot's level, the cameras are arranged from left to right as follows: third camera 113 which is lateral and oriented to the left with a larger field of view horizontally than vertically, second camera 112 which is frontal, sixth camera 116 which is lateral and oriented to the left, first camera 111 which is lateral and oriented to the right, fifth camera 115 which is frontal, fourth camera 114 which is lateral and oriented to the right with a larger field of view horizontally than vertically.

[0051] Each front camera is thus framed by two side cameras belonging respectively to different sets. Furthermore, on each side of the longitudinal axis of the aircraft there is a front camera and two side cameras (the third 113, the second 112 and the sixth cameras 116 for the left side and the first 111, the fifth 115 and the fourth cameras 114 for the right side). The two side cameras 113, 116 on the left side of the aircraft are also both oriented to the left and the two side cameras 111, 114 on the right side of the aircraft are both oriented to the right.

[0052] Thus the distribution of the cameras is symmetrical along the longitudinal axis X of the aircraft.

[0053] In particular, the two front cameras 112, 115 are offset in elevation (and not in bearing) relative to each other. Thus, while the projections of the sighting axes of the two front cameras 112, 115 in the horizontal plane of the aircraft are parallel, the projections of the sighting axes of the two front cameras 112, 115 in the vertical plane of the aircraft are inclined relative to each other.

[0054] This makes it possible to increase the vertical field of view covered by the two assemblies 101, 102. Typically the axes of view of the two front cameras 112, 115 are offset (in elevation and not in bearing) by between 1 and 10 degrees and preferably between 3 and 5 degrees.

[0055] Preferably, the projection of the line of sight of the front camera in the longitudinal plane of the aircraft is parallel to the longitudinal axis X of the aircraft. The lines of sight of the side cameras are inclined with respect to the longitudinal axis X of the aircraft.

[0056] The optronic equipment further comprises an electronic processing unit 103, of the calculator type, connected to the three cameras 111, 112, 113 of the first set 101 to generate a first panoramic strip 104 from the data transmitted by the three cameras 111, 112, 113 of the first set 101 and connected to the three cameras 114, 115, 116 of the second set 102 to generate a second panoramic strip 105 from the data transmitted by the three cameras 114, 115, 116 of the second set 102. The processing unit 103 is arranged inside the aircraft and is connected to an image projection device fitted to a pilot's helmet to project images onto a visor of the latter in front of each eye of the pilot as will be seen later. This type of helmet is known in itself and will not be detailed further here.

[0057] A general panoramic banner, illustrated by the bold frame on the figure 2 , corresponding to the superposition of the first strip 104 and the second strip 105 can thus be defined. The figure 3 is a less schematic view than the figure 2 taking into account distortions and spherical geometries of the fields of view.

[0058] In this case, the figures 2 et 3 are there to facilitate the understanding of the embodiment described but in fact there is no creation of a general panoramic banner by the processing unit 103 or other calculation organs as indicated below.

[0059] It is noted that the first strip 104 and the second strip 105 overlap over large vertical and horizontal areas. In this way, it is possible to project images onto the pilot's visor, providing stereoscopic vision.

[0060] Here, the first set 101 is associated with the user's left eye and the second set 102 with the user's right eye. A view of the first strip 104 is extracted and displayed on the left side of the pilot's visor and a view of the second strip 105 is extracted and displayed on the right side of the pilot's visor, the pilot's brain naturally synthesizing the two views to obtain a relief view.

[0061] The image returned to the pilot is therefore no longer flat but stereoscopic, coming as close as possible to natural vision.

[0062] Once again, in the present embodiment, there is no generation of a general headband but only a generation of the first headband and the second headband, which is sufficient to allow the pilot to have stereoscopic vision by associating each eye with a respective one of said headbands.

[0063] As indicated above, the different cameras of the first set 101 and of the second set 102 are preferably arranged so that the first strip 104 and the second strip 105 overlap as much as possible in order to have the largest possible stereoscopic field of view.

[0064] Advantageously, if one of the assemblies were defective, the other assembly would continue to display images on the driver's visor (but without relief). Typically, the same images would be displayed on both the right and left sides of the visor or the images would only be displayed on one side of the visor.

[0065] The second embodiment thus described makes it possible to ensure redundancy. It is thus noted that each assembly 101, 102 is entirely capable of working alone without the other assembly. Thus the loss of one of the assemblies 101, 102 does not correspond to the loss of half of the field of view but only to the loss of stereoscopic vision, the field of view being substantially identical from one assembly to another.

[0066] Preferably, the location of the cameras is such that it respects an interpupillary distance between the redundant cameras (i.e. the distance separating the viewing axes of the cameras considered).

[0067] The interpupillary distance d1 between the two front cameras is preferably greater than 250 millimeters.

[0068] Similarly, the interpupillary distance d2 between the two right-facing side cameras on the one hand and the interpupillary distance d3 between the two left-facing side cameras on the other hand are also greater than 250 millimeters. In the present case, the lateral interpupillary distance d2, d3 is the same for the right-facing cameras and for the left-facing cameras. The lateral interpupillary distance d2, d3 is approximately 280 millimeters.

[0069] Preferably, the frontal interpupillary distance d1 is greater than the lateral interpupillary distance d2, d3. Typically the frontal interpupillary distance d1 is greater than 350 millimeters and preferably greater than or equal to 400 millimeters.

[0070] In operation, the cameras transmit their data to the processing unit 103 which generates the first banner 104 and the second banner 105 from this data. Depending on the position of the user's headset, the processing unit 103 extracts from the banners a corresponding right view and a left view which it displays in the user's headset.

[0071] It is thus possible to advantageously have multi-user use of the optronic equipment by extracting from the strips as many independent views as there are users.

[0072] This embodiment offers stereoscopic vision over a wide horizontal and vertical field of view with very good resolution, and this with only six cameras.

[0073] The inventors were thus able to obtain a prototype with a field of view of approximately 180 degrees by 90 degrees (plus or minus 5 degrees for the horizontal field of view of 180 degrees and plus or minus 2 degrees for the vertical field of view of 90 degrees) and with a resolution of between 1 and 1.5 milliradians.

[0074] This application is of course not limiting. The equipment according to a particular embodiment of the invention can thus be shaped so as to have an overall field of view of substantially 240 degrees by 90 degrees (plus or minus 5 degrees for the horizontal field of view of 240 degrees and plus or minus 2 degrees for the vertical field of view of 90 degrees) and with a minimum resolution of 1.1 milliradian. The stereoscopic portion of this field is substantially 205 degrees horizontally (plus or minus 5 degrees) by 69 degrees vertically at the lateral level (plus or minus 2 degrees) and 90 degrees vertically at the frontal level (plus or minus 2 degrees).

[0075] Of course, the invention is not limited to what has been described and variations can be made without departing from the scope of the invention as defined by the claims.

[0076] In particular, although in the various embodiments described, the cameras are of the LWIR type, the cameras may of course be different and be of the cooled, uncooled, infrared in the mid-infrared band (better known by the English acronym MWIR) type... In the same way, the optronic equipment may work in other areas of the electromagnetic spectrum than the infrared range. The optronic equipment may thus, as a variant or in addition, operate in the visible, ultraviolet range... The cameras will then be of the corresponding type. Within the same assembly or from one assembly to another, the cameras may not be identical to each other.

[0077] Although only one camera per set is rotated in relation to the other two, a greater number of cameras can be rotated so as to have a larger horizontal field of view than a vertical one.

[0078] Although the six cameras are connected to a single processing unit, each set can be connected to a dedicated processing unit, each control unit then generating the panoramic banner of the associated set. In the event of failure of one of the sets of cameras, it will be possible to use for display only the panoramic banner provided by the non-failing set of cameras (the left eye and the right eye of the user will then see the same image banner). It will also be possible to provide that each of the two processing units, if necessary, can communicate with each of the camera sets: thus in the event of loss of one of the processing units, the other can continue to ensure the generation of the panoramic banner of each of the sets. The processing units will thus be redundant. For example, it will be possible to integrate each processing unit into one of the boxes grouping the cameras of the associated set.

[0079] Although here each set of cameras is assigned to one eye of the user to have a right channel and a left channel, both sets can be assigned to both eyes. A single view will then be projected onto the viewfinder, synthesizing the two sets. For example, a general panoramic strip can be generated from the strips generated for each set and a view extracted that will be projected onto the viewfinder (the strips generated for each set can be generated individually and then associated or can be generated so as to be directly integrated into the general panoramic strip).

[0080] The arrangement of the cameras may differ from what has been indicated. For reasons of layout, space, etc., it may be preferable to have cameras arranged convexly rather than concavely as indicated. The cameras of the first set would thus be on one side and the cameras of the second set on the other side.

[0081] The two sets can be arranged so that the first strip and the second strip overlap completely, in order to have the largest possible stereoscopic field of view, or only partially, in order to widen the overall field of view.

[0082] When the aircraft is equipped with several sets of cameras distributed around its perimeter (for example two front sets as described here, and two sets arranged at the rear, and possibly two sets arranged on each side of the aircraft), the processing unit is arranged to control the display of the images coming from the cameras positioned on the aircraft in the direction of the pilot's gaze. The direction of the pilot's gaze is estimated as a function of the orientation of the pilot's helmet relative to the cockpit of the aircraft.As examples for detecting the orientation of the helmet relative to the aircraft cockpit, the helmet may be equipped with an inertial unit which makes it possible to detect the orientation of the helmet in space (knowing the orientation of the aircraft in space by the aircraft's inertial unit, it is possible to determine the orientation of the helmet relative to the cockpit) or the cockpit may be equipped with cameras to detect optical targets carried by the helmet and thus determine the orientation of the helmet relative to the cockpit).

[0083] The invention can be used with any display device connected to the processing unit 103. Instead of a projection device on the visor of the pilot's helmet, the pilot's helmet can comprise two displays, each placed in front of one of the pilot's eyes to display the panoramic banners.

Claims

1. Optronic equipment for assisting with piloting an aircraft, the equipment including a first set (101) of three cameras, called first camera, second camera, and third camera, arranged on the aircraft to generate a first panoramic strip from data transmitted by the three cameras of the first set and a second set (102) of three cameras, called fourth camera, fifth camera, and sixth camera, arranged on the aircraft to generate a second panoramic strip from data transmitted by the three cameras of the second set, the cameras being mounted at the front of the aircraft at its nose, three cameras being situated on the right of the nose of the aircraft and three cameras being situated on the left of its nose, the third camera (113) and fourth camera (114) occupying an extreme lateral position on the aircraft, relative to the other fourth cameras of the first and second sets, the third camera (113) and fourth camera (114) being arranged so as to have a field of view that is greater horizontally than vertically, wherein only the third camera and fourth camera of the six cameras in the two sets are arranged so as to have a field of view that is greater horizontally than vertically, the third camera (113) and the fourth camera (114) bracketing the other four cameras (111, 112, 115, 116), wherein the two sets are arranged in such a manner that the two strips overlap, at least in part, to provide the pilot with stereoscopic vision.

2. Equipment according to claim 1, wherein at least two contiguous cameras (112, 116, 111, 115) are arranged in a concave configuration.

3. Equipment according to claim 2, wherein the two cameras arranged at the center of the six cameras are crossed so that a first camera (112) of the first set and a first camera (116) of the second set are arranged in a concave configuration and so that a second camera (111) of the first set and a second camera (115) of the second set are also arranged in a concave configuration.

4. Equipment according to any one of claims 1 to 3, wherein two cameras (112, 115) belonging to respective different sets are offset relative to each other in elevation.

5. Equipment according to claim 1, comprising an electronic processor unit connected to the cameras and arranged to form at least one image from the two image strips.

6. Equipment according to claim 5, wherein the image formed from the two image strips is a wide-field image.

7. Equipment according to claim 1, comprising an electronic processor unit connected to the cameras and arranged to display the two image strips in stereoscopic manner.

8. Equipment according to any one of claims 1 to 7, wherein the cameras (111, 112, 113) of the first set (101) are powered by a first power supply, and the cameras (114, 115, 116) of the second set (102) are powered by a second power supply that is independent of the first power supply.

9. Equipment according to any preceding claim, including at least one block in which the cameras are arranged.

10. Equipment according to any preceding claim, wherein the cameras operate in the infrared range.

11. Equipment according to the preceding claim, wherein the cameras are of the LWIR type.

12. Equipment according to any preceding claim, wherein the cameras are not cooled.

13. Equipment according to any preceding claim, comprising a processor unit connected to the cameras and to a helmet fitted with a device for displaying an image visible to the eyes of the pilot wearing the helmet.