Method for estimating the geographic coordinates of an aircraft, aircraft equipped with a geographic coordinate estimation device operating according to said method

Abstract

Method for estimating the geographic coordinates of an aircraft, aircraft equipped with a geographic coordinate estimation device operating according to said method. The invention relates to a method for estimating the geographic coordinates of an aircraft comprising, during a flight over an area (Z), a step of estimating the geographic coordinates of the aircraft (20) using satellite signals, a step of estimating the geographic coordinates of the aircraft from baro-inertial data of the aircraft and the last estimated geographic coordinates, at least one step of estimating the geographic coordinates of the aircraft (20) from at least one image captured of the area (Z) overflown by the aircraft (20) as well as a step of consolidating the estimates of the geographic coordinates of the aircraft (20) obtained during the steps of estimating the geographic coordinates from the baro-inertial data and at least one captured image.The invention also relates to an aircraft comprising a device enabling the implementation of said method for estimating the aircraft's geographic coordinates. Figure 5.

Description

Title of the invention: Method for estimating the geographical coordinates of an aircraft, aircraft equipped with a device for estimating geographical coordinates operating according to said method

[0001] The present application relates to a method for estimating the geographical coordinates of an aircraft and to an aircraft equipped with a device for estimating geographical coordinates operating according to said method. The latter is more particularly suitable for self-piloted vertical take-off and landing aircraft known as VTOL.

[0002] Some VTOL type aircraft are designed to provide passenger transport in an urban environment in the manner of a taxi. Such an aircraft, described in document FR3078554 for example, comprises a passenger compartment configured to transport 2 to 4 passengers as well as several rotors to enable the passenger compartment to fly.

[0003] According to one configuration, this type of aircraft is configured to move autonomously by following a flight plan and comprises a device for estimating in real time its geographical coordinates (latitude, longitude and altitude) in a terrestrial reference frame RT. According to an embodiment visible in [Fig.l], a device for estimating geographical coordinates of an aircraft 10 comprises at least one receiver 12 configured to receive signals 14 transmitted by several satellites 16. Knowing for each signal 14 received the propagation speed of the signal 14 as well as the propagation duration of the signal 14 between the satellite 16 and the receiver 12, it is possible to determine the distance between the receiver 12 (and therefore the aircraft 10) and the satellite 16 having transmitted the signal 14.Knowing the position in the terrestrial reference frame RT of each satellite 16 and the distance between the aircraft 10 and several satellites 16, it is possible to estimate the geographical coordinates of the aircraft 10 in the terrestrial reference frame RT.

[0004] In certain circumstances, the signals 14 transmitted by the satellites 16 do not make it possible to estimate the geographical coordinates of the aircraft 10 in the terrestrial reference frame RT.

[0005] Document AT511460 proposes a method for estimating geo coordinates graphics of an aircraft by comparing at least one image of the area flown over by the aircraft, captured by an image sensor attached to the aircraft, as well as at least one georeferenced image stored in a database corresponding to the captured image. This comparison makes it possible to estimate the geographical coordinates of the center of the captured image and then, knowing the approximate position of the aircraft relative to the center of the captured image, to estimate the geographical coordinates of the aircraft.

[0006] This method of estimating the geographical coordinates of an aircraft does not make it possible to obtain geographical coordinates that are sufficiently precise to allow autonomous navigation of the aircraft.

[0007] The present invention aims to remedy all or part of the drawbacks of the prior art.

[0008] To this end, the invention relates to a method for estimating the geographical coordinates of an aircraft comprising, during a flight over an area, a step of estimating the geographical coordinates of the aircraft using satellite signals, a step of storing at least the last estimated geographical coordinates of the aircraft, a step of determining baro-inertial data of the aircraft as well as a step of estimating the geographical coordinates of the aircraft from the determined baro-inertial data and the last estimated and stored geographical coordinates.

[0009] According to the invention, the method for estimating the geographical coordinates of the aircraft comprises at least one step of estimating the geographical coordinates of the aircraft from at least one captured image of the area flown over by the aircraft as well as a step of consolidating the estimates of the geographical coordinates of the aircraft obtained during the steps of estimating the geographical coordinates from the baro-inertial data and from at least one captured image.

[0010] This method allows a more precise estimation of the geographical coordinates of an aircraft thanks to the consolidation of estimates from different sources.

[0011] According to another characteristic, the step of estimating the geographical coordinates of the aircraft from at least one captured image uses at least one of the baro-inertial data of the aircraft.

[0012] According to another characteristic, during a first step of estimating the geographical coordinates of the aircraft from at least one captured image, the aircraft occupying a first position then a second position after the first position, at least one captured image of the zone at the right of the second position is compared to at least one other captured image of the zone at the right of the first position to estimate relative geographical coordinates between the first and second positions then the geographical coordinates of the second position are estimated from the known geographical coordinates of the first position and the estimation of the relative geographical coordinates between the first and second positions.

[0013] According to another characteristic, during a second step of estimating the geographical coordinates of the aircraft from at least one captured image, at least one captured image of the area is compared to at least one stored and georeferenced image corresponding to the captured image to estimate geographical coordinates. absolute values ​​of the aircraft.

[0014] According to another characteristic, the method for estimating the geographical coordinates of the aircraft comprises a step of estimating the geographical coordinates of the aircraft using telecommunication signals.

[0015] According to another characteristic, the method for estimating the geographical coordinates of the aircraft comprises, in addition to the step of estimating the geographical coordinates of the aircraft from the baro-inertial data, at least two estimation steps among a step of estimating the geographical coordinates using the telecommunication signals, a step of estimating the geographical coordinates by comparing at least two captured images as well as a step of estimating the geographical coordinates by comparing at least one captured image and at least one stored and georeferenced image.

[0016] According to another characteristic, the method for estimating the aircraft comprises a step of estimating the geographical coordinates of the aircraft from the baro-inertial data, a step of estimating the geographical coordinates using the telecommunication signals, a step of estimating the geographical coordinates by comparing at least two captured images as well as a step of estimating the geographical coordinates by comparing at least one captured image and at least one stored and georeferenced image.

[0017] According to another characteristic, the estimation steps are carried out in parallel and make it possible to obtain several estimates which are consolidated so as to obtain a consolidated estimate of the geographical coordinates of the aircraft.

[0018] According to another characteristic, the method for estimating the geographical coordinates of the aircraft is an iterative method, the consolidated estimate of the geographical coordinates of the aircraft at a second position being obtained from the geographical coordinates of the aircraft at a first position prior to the second position, which are the last known geographical coordinates obtained from the satellite signals or a consolidated estimate of the geographical coordinates of the aircraft at the first position.

[0019] The invention also relates to an aircraft comprising a device for estimating the geographical coordinates of an aircraft allowing the implementation of the method according to one of the preceding characteristics. This device for estimating geographical coordinates comprises a system for estimating geographical coordinates using satellite signals configured to estimate the geographical coordinates of at least one position occupied by the aircraft using satellite signals, at least one system for estimating geographical coordinates using baro-inertial data configured to estimate geographical coordinates of at least one position occupied by the aircraft from baro- inertial coordinates of the aircraft and geographic coordinates of a position previously occupied by the aircraft, at least one system for estimating geographic coordinates by comparing images configured to estimate geographic coordinates of the aircraft by comparing at least two images and a processing system configured to consolidate different estimates of the geographic coordinates of the aircraft.

[0020] According to another characteristic, the device for estimating the geographical coordinates comprises at least one first system for estimating the geographical coordinates by comparing images configured to capture at least first and second images of at least part of the area flown over, compare the first and second captured images and estimate geographical coordinates of the aircraft at the time of capturing the second captured image from the known geographical coordinates of the aircraft at the time of capturing the first captured image and baro-inertial data.

[0021] According to another characteristic, the device for estimating the geographical coordinates comprises at least one second system for estimating the geographical coordinates by comparing images configured to capture at least one image of at least part of the area flown over, compare the captured image with at least one stored and georeferenced image corresponding to the captured image and estimate the geographical coordinates of the aircraft at the time of capturing the captured image from the comparison of the images and baro-inertial data.

[0022] According to another characteristic, the device for estimating geographic coordinates comprises at least one system for estimating geographic coordinates using telecommunication signals.

[0023] Other characteristics and advantages will emerge from the description of the invention which follows, a description given by way of example only, with reference to the appended drawings, among which:

[0024] [Fig.l] is a side schematic representation of a VTOL type aircraft, which flies over an urban area and uses satellite signals to geolocate itself, illustrating an embodiment of the prior art,

[0025] [Fig.2] is a schematic representation from above of a VTOL type aircraft, which flies over an urban area and uses satellite signals to geolocate itself, illustrating one embodiment of the invention,

[0026] [Fig.3] is a diagram of a method for estimating the geographic coordinates of an aircraft illustrating an embodiment of the invention,

[0027] [Fig.4] is a schematic representation from above of a VTOL type aircraft, which flies over an urban area and uses the coordinates of points of interest to estimate the geographic coordinates of the aircraft, illustrating an embodiment of the invention,

[0028] [Fig.5] is a schematic representation from above of a VTOL type aircraft, which flies over an urban area and uses at least one captured image to estimate the geographical coordinates of the aircraft, illustrating an embodiment of the invention,

[0029] [Fig.6] is a schematic representation from above of a VTOL type aircraft, which flies over an urban area and uses telecommunication antennas to estimate the geographical coordinates of the aircraft, illustrating an embodiment of the invention.

[0030] Although described as applied to a VTOL type aircraft, the invention is in no way limited to this type of aircraft and can be applied to any type of aircraft, whether self-piloted or not.

[0031] As illustrated in [Fig.2], an aircraft 20 performs a journey by flying over an area Z which may be urbanized.

[0032] According to one configuration, this zone Z comprises a given relief RE (visible in [Fig.5]) in a terrestrial reference frame RT, points of interest POU, POI2, POI3, POI4,... (visible in [Fig.4]) each having known point of interest coordinates in the terrestrial reference frame RT, as well as at least telecommunication antennas ANT1, ANT2, ANT3,... (visible in [Fig.6]) each having known antenna coordinates in the terrestrial reference frame RT.

[0033] Any point in the terrestrial reference frame RT comprises three geographic coordinates: a latitude, a longitude and an altitude.

[0034] Each telecommunication antenna ANT1, ANT2, ANT3 is configured to transmit at least one telecommunication signal. According to one embodiment, the telecommunication antennas ANT1, ANT2, ANT3 and the transmitted telecommunication signals operate according to a mobile telephone network standard called “5G”. Of course, the invention is not limited to this telecommunication standard.

[0035] The aircraft 20 comprises a flight management system also called FMS (for Flight Management System in English) as well as a device for estimating geographical coordinates 22 of the aircraft 20 in the terrestrial reference frame RT which comprises a system for estimating geographical coordinates using satellite signals 24 configured to estimate the geographical coordinates in the terrestrial reference frame RT of at least one position occupied by the aircraft 20 during its journey using satellite signals. According to one mode of operation, the system for estimating geographical coordinates using satellite signals 24 is configured to regularly estimate, preferably in real time, the geographical coordinates in the terrestrial reference frame RT of different positions occupied by the aircraft 20 distributed over the journey.

[0036] This system for estimating geographic coordinates using satellite signals 24 comprises at least one satellite signal receiver 26 secured to the aircraft and configured to receive satellite signals transmitted by several satellites as well as a processing unit 28 configured to estimate the geographic coordinates, for at least one position of the aircraft, from the satellite signals. This system for estimating geographic coordinates using satellite signals 24 as well as its mode of operation are not further described because they are known to those skilled in the art.

[0037] The device for estimating the geographical coordinates 22 also comprises at least one storage system 30 configured to store at least the last geolocation coordinates determined in particular by the system for estimating the geolocation coordinates using satellite signals 24. According to one configuration, this storage system 30 is integrated into the flight management system.

[0038] The device for estimating the geographical coordinates 22 comprises at least one system for estimating the geographical coordinates using baro-inertial data 32 configured to estimate geographical coordinates in the terrestrial reference frame RT of at least one position occupied by the aircraft 20 during its journey from baro-inertial data of the aircraft 20 and the geographical coordinates of the position previously occupied by the aircraft 20, which are for example determined by the system for estimating the geographical coordinates using satellite signals 24.

[0039] This system for estimating geographic coordinates using baro-inertial data 32 comprises at least one navigation sensor 34 chosen from accelerometers, gyrometers, magnetometers or barometric altimeters. This list is not exhaustive.

[0040] According to one embodiment, the system for estimating geographic coordinates using baro-inertial data 32 comprises a set of navigation sensors 34 which may be an attitude and heading reference system also called AHRS (for attitude and heading reference system in English) or an inertial unit. Whatever the embodiment, the system for estimating geographic coordinates using baro-inertial data 32 is configured to determine an attitude vector between first and second successive positions occupied by the aircraft 20 and, knowing the geographic coordinates of the first position, determine the geographic coordinates of the second position. The attitude vector comprises at least one component along an axis of the terrestrial reference frame RT, generally three components along the three orthonormal axes of the terrestrial reference frame RT.According to one configuration, the geographic coordinate estimation system using baro-inertial data 32 is configured to determine the altitude of the aircraft 20.

[0041] The geographical coordinate estimation device 22 comprises at least one database 36 storing, for each telecommunications antenna ANT1, ANT2, ANT3, its antenna coordinates in the terrestrial reference frame RT as well as at least one georeferenced image of the zone Z flown over by the aircraft 20. By georeferenced, it is meant that at least certain points of the image have known geographical coordinates in the terrestrial reference frame RT.

[0042] According to one arrangement, this database 36 is stored in the flight management system.

[0043] According to one embodiment, each stored and georeferenced image of the zone Z comprises data from relief data relating to the relief RE of the zone Z, the coordinates of points of interest in the terrestrial reference frame RT of each point of interest POU, POI2, POI3, POI4 present on the image or the antenna coordinates in the terrestrial reference frame RT of each telecommunications antenna ANT1, ANT2, ANT3 present on the image. This list of data is not exhaustive.

[0044] According to one embodiment, the geographical coordinate estimation device 22 comprises at least one system for estimating geographical coordinates using telecommunication signals 38 configured to estimate, from the known positions of the telecommunication antennas ANT1, ANT2, ANT3, geographical coordinates in the terrestrial reference frame RT of at least one position occupied by the aircraft 20 during its journey. According to one mode of operation, the system for estimating geographical coordinates using telecommunication signals 38 is configured to regularly estimate, preferably in real time, the geographical coordinates in the reference frame RT of different positions occupied by the aircraft 20 distributed over the journey from the known positions of the telecommunication antennas ANT1, ANT2, ANT3, as illustrated in [Fig. 6].

[0045] This system for estimating geographic coordinates using telecommunication signals 38 comprises at least one telecommunication signal receiver 40 configured to receive signals transmitted by several telecommunication antennas ANT1, ANT2, ANT3 as well as a processing unit 42 configured to estimate the geographic coordinates in the terrestrial reference frame RT, for at least one position of the aircraft 20, from the received telecommunication signals, knowing the antenna coordinates in the terrestrial reference frame RT of each telecommunication antenna ANT1, ANT2, ANT3. This system for estimating geographic coordinates using telecommunication signals 38 as well as its mode of operation are not described further because they are known to those skilled in the art.

[0046] According to one embodiment, the device for estimating geographic coordinates 22 comprises at least a first system for estimating geographic coordinates by comparing images 44 configured to capture at least first and second images of at least part of the zone Z flown over, comparing the first and second captured images and estimating geographic coordinates of the aircraft 20 at the time of capturing the second captured image from the known geographic coordinates of the aircraft 20 at the time of capturing the first captured image as well as baro-inertial data (altitude and attitude vector of the aircraft) estimated by the geographic coordinate estimation system using baro-inertial data 32.

[0047] The first system for estimating geographic coordinates by comparing images 44 comprises at least one image sensor 46 connected to the aircraft 20 configured to capture at least one image as well as at least one image analysis unit 48 configured to analyze several successive captured images in order to estimate the geographic coordinates in the terrestrial reference frame RT of the aircraft 20. According to one embodiment, the first system for estimating geographic coordinates by comparing images 44 comprises a set of image sensors 46 from among conventional cameras, infrared cameras, thermal cameras or laser remote sensing devices called LIDAR. This list of image sensors 46 is not exhaustive. Each image sensor 46 connected to the aircraft 20 may be fixed or mobile relative to the aircraft 20.

[0048] For the remainder of the description, the term “image” means a single image or several successive images. In addition, a captured image may come from a single image sensor 46 or be obtained by consolidating several captured images coming from different image sensors 46.

[0049] Each image sensor 46 comprises a sighting axis A46 (visible in [Fig.5]) having a direction which is known in a reference frame linked to the aircraft 20.

[0050] According to a first embodiment, the image analysis unit 48 is configured to identify at least one same fixed point in successive first and second images and estimate geographical coordinates of the aircraft at the time of capturing the second captured image from the known geographical coordinates of the aircraft at the time of capturing the first captured image, from data of at least one stored and georeferenced image corresponding to the first and second captured images as well as from the altitude and the attitude vector of the aircraft 20 evaluated by the geographical coordinate estimation system using baro-inertial data 32.

[0051] According to a configuration of this first embodiment, the fixed point is a point of interest POU, POI2, POI3, POI4 and / or the image analysis unit 44 is configured to identify three points of interest POU, POI2, POI3, POI4 in the first and second captured images.

[0052] According to this first mode of operation, from data of at least one image stored and georeferenced corresponding to the first and second captured images such as the distance between two points of the stored and georeferenced image or the distance of a building from the stored and georeferenced image for example, it is possible to estimate a scale and then from this scale to evaluate the distance traveled between the first and second captured images. Knowing the attitude vector and the altitude of the aircraft 20 and the distance traveled between the first and second captured images, it is possible to estimate the geographical coordinates of the aircraft 20 at the time of the second captured image from the geographical coordinates of the aircraft 20 at the time of the first captured image.

[0053] According to a second mode of operation visible in [Fig. 4], the image analysis unit 48 is configured to identify at least one same fixed point in successive first and second images, evaluate a direction of the line of sight of the image sensor 46 for each of the first and second captured images knowing the direction of the line of sight relative to the aircraft 20 and the attitude vector of the aircraft 20 at the time of capturing each of the first and second captured images and estimate, by triangulation, geographical coordinates of the aircraft at the time of capturing the second captured image from the known geographical coordinates of the aircraft 20 at the time of capturing the first captured image.

[0054] Of course, the invention is not limited to these embodiments and operating modes for the first system for estimating geographic coordinates by comparing images 44. Whatever the embodiment and operating mode, the first system for estimating geographic coordinates by comparing images 44 makes it possible to estimate relative geographic coordinates between the first and second positions of the aircraft 20 from the first and second images captured at right angles to the first and second positions respectively as well as from the attitude vector of the aircraft 20 estimated by the system for estimating geographic coordinates using baro-inertial data 32.

[0055] According to one embodiment, the device for estimating the geographical coordinates 22 comprises at least one second system for estimating the geographical coordinates by comparing images 50 configured to capture at least one image of at least a portion of the zone Z flown over, compare the captured image with at least one stored and georeferenced image corresponding to the captured image and estimate the geographical coordinates of the aircraft 20 at the time of capturing the captured image from the comparison of the images and the baro-inertial data (altitude and attitude vector of the aircraft 20) estimated by the system for estimating the geographical coordinates using baro-inertial data 32.

[0056] The second system of estimating geographic coordinates by comparison image 50 comprises at least one image sensor 46' connected to the aircraft 20 configured to capture at least one image as well as at least one image analysis unit 48' configured to analyze at least one captured image and at least one stored and georeferenced image corresponding to the captured image in order to estimate the geographic coordinates in the terrestrial reference frame RT of the aircraft 20.

[0057] According to one mode of operation, the image analysis unit 48' is configured to: a. make the captured image coincide with at least one stored and georeferenced image so as to associate with each point of the captured image a point of the stored and georeferenced image whose geographical coordinates in the terrestrial reference frame RT are known, b. estimate geographic coordinates of at least one point of the captured image whose position relative to the aircraft 20 is known, then c. estimating the geographic coordinates of the aircraft 20 from the geographic coordinates of the point of the captured image, the direction of the line of sight A46' of the image sensor 46' having captured the image, the attitude vector and the altitude of the aircraft 20 estimated by the geographic coordinate estimation system using baro-inertial data 32.

[0058] Relief data are used to match the captured image with at least one stored and georeferenced image. The image analysis unit 48' is configured to determine the geographic coordinates of the center of the captured image from the known coordinates of the point of the stored and referenced image corresponding to the center of the captured image. Knowing the direction of the line of sight A46' relative to the aircraft 20, the altitude and the attitude vector of the aircraft 20 at the time of capturing the captured image, it is possible to estimate the geographic coordinates of the aircraft 20 from the geographic coordinates of the center of the captured image.

[0059] Of course, the invention is not limited to these embodiments and operating modes for the second system for estimating geographic coordinates by comparing images 50. Whatever the embodiment and operating mode, the second system for estimating geographic coordinates by comparing images 50 makes it possible to estimate absolute geographic coordinates of the aircraft 20 from at least one captured image, from at least one stored and georeferenced image corresponding to the captured image, from the altitude and from the attitude vector of the aircraft 20 estimated by the system for estimating geographic coordinates using baro-inertial data 32.

[0060] The method for estimating the geographic coordinates of an aircraft 20 comprises, during a flight over a zone Z, a step of estimating the geo coordinates graphics of the aircraft 20 using satellite signals, a step of storing at least the last geographical coordinates of the aircraft 20 in the event of it being impossible to estimate the geographical coordinates using the satellite signals, a step of determining baro-inertial data of the aircraft 20 as well as a step of estimating the geographical coordinates of the aircraft from the determined baro-inertial data and the last stored estimated geographical coordinates.

[0061] To remedy a possible drift, the method for estimating the geographical coordinates of the aircraft 20 comprises at least one step of estimating the geographical coordinates of the aircraft 20 from at least one captured image of the zone Z flown over by the aircraft 20 as well as a step of consolidating the geographical coordinates of the aircraft 20 from the estimations of the geographical coordinates obtained during the steps of estimating the geographical coordinates from the baro-inertial data and from at least one captured image.According to a first variant, during a first step of estimating the geographical coordinates of the aircraft 20 from at least one captured image, at least one captured image of the zone Z at right angles to a second position of the aircraft 20 is compared to at least one other captured image of the zone Z at right angles to a first position prior to the second of the aircraft 20 to estimate relative geographical coordinates between the first and second positions, then the geographical coordinates of the second position are estimated from the known geographical coordinates of the first position and the estimation of the relative geographical coordinates between the first and second positions.

[0062] According to a second variant, during a second step of estimating the geographical coordinates of the aircraft (20) from at least one captured image, at least one captured image of the zone Z is compared to at least one stored and georeferenced image corresponding to the captured image to estimate absolute geographical coordinates of the aircraft 20.

[0063] Whatever the variant, to improve the accuracy of the estimation of the geographical coordinates obtained from at least one captured image of the zone Z flown over by the aircraft, the step of estimating the geographical coordinates of the aircraft 20 from at least one captured image uses at least one of the baro-inertial data of the aircraft, in particular the attitude vector of the aircraft. Thus, the estimation obtained from the baro-inertial data is consolidated by data obtained from at least one captured image of the zone Z flown over by the aircraft. In parallel, the estimation obtained from at least one captured image is consolidated by at least one of the baro-inertial data.

[0064] According to one embodiment, the method for estimating the geo- coordinates aircraft graphics comprises, in addition to the step of estimating the geographic coordinates of the aircraft from the baro-inertial data, a step of estimating the geographic coordinates of the aircraft 20 using telecommunication signals.

[0065] According to another embodiment, the method for estimating the geographical coordinates of the aircraft 20 comprises, in addition to the step of estimating the geographical coordinates of the aircraft from the baro-inertial data, at least two estimation steps among a step of estimating the geographical coordinates using the telecommunication signals, a step of estimating the geographical coordinates by comparing at least two captured images as well as a step of estimating the geographical coordinates by comparing at least one captured image and at least one stored and georeferenced image.

[0066] According to another embodiment, the method for estimating the aircraft comprises a step of estimating the geographical coordinates of the aircraft from the baro-inertial data, a step of estimating the geographical coordinates using the telecommunication signals, a step of estimating the geographical coordinates by comparing at least two captured images as well as a step of estimating the geographical coordinates by comparing at least one captured image and at least one stored and georeferenced image. In addition, the device for estimating the geographical coordinates of an aircraft comprises a processing system 52 configured to consolidate different estimates of the geographical coordinates.

[0067] Whatever the embodiment, as illustrated in [Fig.3], the estimation steps are carried out in parallel and respectively make it possible to obtain several estimates E1, E2, E3, E4 which are consolidated so as to obtain a consolidated estimate EC corresponding for example to a weighted or unweighted average of the estimates E1, E2, E3, E4.

[0068] As illustrated in [Fig. 3], the method for estimating the geographical coordinates of the aircraft 20 is an iterative method, the consolidated estimate ECi of the geographical coordinates of the aircraft 20 at a position i being obtained from the geographical coordinates of the aircraft at the previous position i-1, which may be the last known geographical coordinates obtained from the satellite signals or a consolidated estimate ECi-1 of the geographical coordinates of the aircraft at the previous position i-1. This iterative estimation method allows a consolidated estimate of the geographical coordinates of the aircraft, regular over time, potentially in real time.

[0069] Whatever the embodiment, the method for estimating the geographic coordinates of an aircraft allows a more precise estimation thanks to the consolidation estimates from different sources, which helps to significantly improve flight safety.

Claims

Claims

1. Method for estimating the geographical coordinates of an aircraft (20) comprising, during a flight over an area (Z), a step of estimating the geographical coordinates of the aircraft (20) using satellite signals, a step of storing at least the last estimated geographical coordinates of the aircraft (20), a step of determining baro-inertial data of the aircraft (20) as well as a step of estimating the geographical coordinates of the aircraft from the determined baro-inertial data and the last estimated and stored geographical coordinates;characterized in that the method for estimating the geographical coordinates of the aircraft (20) comprises at least one step of estimating the geographical coordinates of the aircraft (20) from at least one captured image of the zone (Z) flown over by the aircraft (20) as well as a step of consolidating the estimates of the geographical coordinates of the aircraft (20) obtained during the steps of estimating the geographical coordinates from the baro-inertial data and from at least one captured image.;

2. Method for estimating the geographical coordinates of an aircraft according to claim 1, characterized in that the step of estimating the geographical coordinates of the aircraft (20) from at least one captured image uses at least one of the baro-inertial data of the aircraft.

3. Method for estimating the geographical coordinates of an aircraft according to one of the preceding claims, characterized in that during a first step of estimating the geographical coordinates of the aircraft (20) from at least one captured image, the aircraft (20) occupying a first position then a second position subsequent to the first position, at least one captured image of the zone (Z) at the right of the second position is compared to at least one other captured image of the zone (Z) at the right of the first position to estimate relative geographical coordinates between the first and second positions, then the geographical coordinates of the second position are estimated from the known geographical coordinates of the first position and the estimation of the relative geographical coordinates between the first and second positions.

4. Method for estimating the geographic coordinates of an aircraft according to one of the preceding claims, characterized in that during a second step of estimating the geographical coordinates of the aircraft (20) from at least one captured image, at least one captured image of the zone (Z) is compared to at least one stored and geo-referenced image corresponding to the captured image to estimate absolute geographical coordinates of the aircraft (20).

5. Method for estimating the geographical coordinates of an aircraft according to one of the preceding claims, characterized in that the method for estimating the geographical coordinates of the aircraft comprises a step of estimating the geographical coordinates of the aircraft (20) using telecommunication signals.

6. Method for estimating the geographical coordinates of an aircraft according to one of the preceding claims, characterized in that the method for estimating the geographical coordinates of the aircraft (20) comprises, in addition to the step of estimating the geographical coordinates of the aircraft from the baro-inertial data, at least two estimation steps among a step of estimating the geographical coordinates using the telecommunication signals, a step of estimating the geographical coordinates by comparing at least two captured images as well as a step of estimating the geographical coordinates by comparing at least one captured image and at least one stored and georeferenced image.

7. Method for estimating the geographical coordinates of an aircraft according to the preceding claim, characterized in that the method for estimating the aircraft comprises a step of estimating the geographical coordinates of the aircraft from the baro-inertial data, a step of estimating the geographical coordinates using the telecommunication signals, a step of estimating the geographical coordinates by comparing at least two captured images as well as a step of estimating the geographical coordinates by comparing at least one captured image and at least one stored and georeferenced image.

8. Method for estimating the geographical coordinates of an aircraft according to one of the preceding claims, characterized in that the estimation steps are carried out in parallel and make it possible to obtain several estimates (El, E2, E3, E4) which are consolidated so as to obtain a consolidated estimate (EC) of the geographical coordinates of the aircraft (20).

9. Method for estimating the geographical coordinates of an aircraft according to the preceding claim, characterized in that the method for estimating the geographical coordinates of the aircraft (20) is an iterative method, the consolidated estimate (ECi) of the geographical coordinates of the aircraft (20) at a second position (i) being obtained from the geographical coordinates of the aircraft at a first position (i-1) prior to the second position, which are the last known geographical coordinates obtained from the satellite signals or a consolidated estimate (ECi-1) of the geographical coordinates of the aircraft at the first position (i-1).

10. Aircraft comprising a device for estimating the geographical coordinates (22) of an aircraft enabling the implementation of the method according to one of the preceding claims, characterized in that the device for estimating the geographical coordinates (22) comprises a system for estimating the geographical coordinates using satellite signals (24) configured to estimate the geographical coordinates of at least one position occupied by the aircraft (20) using satellite signals, at least one system for estimating the geographical coordinates using baro-inertial data (32) configured to estimate geographical coordinates of at least one position occupied by the aircraft (20) from baro-inertial data of the aircraft (20) and geographical coordinates of a position previously occupied by the aircraft (20),at least one system for estimating geographic coordinates by comparing images (44) configured to estimate geographic coordinates of the aircraft (20) by comparing at least two images as well as a processing system (52) configured to consolidate different estimates of the geographic coordinates of the aircraft (20).,

11. Aircraft according to the preceding claim, characterized in that the device for estimating the geographical coordinates (22) comprises at least a first system for estimating the geographical coordinates by comparing images (44) configured to capture at least first and second images of at least a part of the zone (Z) flown over, compare the first and second images captured and estimate geographical coordinates of the aircraft (20) at the time of capturing the second image captured from the known geographical coordinates of the aircraft (20) at the time of capturing the first captured image and baro-inertial data.

12. Aircraft according to one of claims 10 to 11, characterized in that the device for estimating the geographical coordinates (22) comprises at least one second system for estimating the geographical coordinates by comparing images (50) configured to capture at least one image of at least part of the zone (Z) flown over, compare the captured image with at least one stored and georeferenced image corresponding to the captured image and estimate the geographical coordinates of the aircraft (20) at the time of capturing the captured image from the comparison of the images and baro-inertial data.

13. Aircraft according to one of claims 10 to 12, characterized in that the device for estimating geographic coordinates (22) comprises at least one system for estimating geographic coordinates using telecommunication signals (38).

Images