Method and system for simulating aerial targets

Abstract

- Method and system for simulating aerial targets. - The simulation system (1) for simulating aerial targets comprises at least one set (7) of drones (8A, 8B), at least one (8B) of the drones of the set (7) of drones being equipped with a signal generator (11) of a first type and at least one other drone (8A) of the set (7) being equipped with a signal generator (12) of a second type, the system (1) comprising a synchronization device configured to synchronize the drones (8A, 8B) of the set (7) of drones so that they simulate the same target (2A), the system (1) thus making it possible to test sensors (4, 5) of different types of a monitoring system (3) and thus being particularly suitable for forming part of a test system (9) intended to test a heterogeneous multi-sensor monitoring system (3).

Description

Method and system for simulating aerial targets.

[0001] The present invention relates to a method and system for simulating aerial targets.

[0002] Although not exclusively, such an aerial target simulation system can be used to test the ability of the systems specified below to detect and track aerial targets, i.e. flying machines (such as, for example, airplanes, helicopters, drones or missiles) also specified below. State of the art

[0003] Document EP3 296 760 B1 discloses a method and system for testing radar systems. This test system comprises a drone flown near the radar system under test. The drone is equipped with means capable of receiving radar signals from the radar system, processing the received radar signals, generating a radar response signal, and transmitting this radar response signal back to the radar. This radar response signal is configured to simulate a radar echo from a fictitious moving target. This fictitious moving target can represent a ballistic missile.

[0004] This test system has the disadvantage of only being able to test radar systems.

[0005] However, a protection system, designed in particular to protect a site or ships against potential air attacks, generally includes various means (or sensors) for detecting enemy targets, and not just radar systems. The aforementioned standard test system is therefore not capable of testing a surveillance system, such as those currently in use, particularly heterogeneous multi-sensor systems.

[0006] Therefore, there is a need to have a system available to help test a surveillance system, including means (or sensors) for detecting different types of aerial targets.

[0007] The present invention aims to satisfy this need. It relates to a simulation system for at least one aerial target, which comprises at least one set of drones, each drone being equipped with a signal generator capable of emitting a signal representative of an aerial target to be simulated.

[0008] According to the invention, at least one of the drones in the drone set is equipped with a signal generator of a first type and at least one other drone in the drone set is equipped with a signal generator of a second type (different from said first type), and said system includes a synchronization device configured to synchronize the drones in the drone set so that they simulate a single target.

[0009] Thus, thanks to the invention, the aerial target simulation system is able to generate and transmit, via different signal generators mounted on at least two drones, signals of different types (for example, at least one radio frequency signal and at least one infrared signal). Furthermore, the drones are synchronized, as detailed below, so that the different types of signals allow for the simulation of a single aerial target.

[0010] Thus, if this aerial target simulation system is used to test a system, particularly a surveillance system and / or the various components of a weapon system, it can simultaneously test different sensors (or detection devices), such as a radar and an infrared sensor, within that system. Furthermore, it allows for the testing of detection devices (or sensors) located in different places within the same area. It can also test sensors located in multiple areas. For example, the sensors can be mounted in fixed positions (permanently) or deployed on vehicles or ships (not permanently), for instance, by being mounted on tripods.

[0011] In the context of the present invention, "zone" means a portion of a surface (terrestrial or maritime) or elements installed on such a portion of a surface. This may include, in particular, a site, especially a terrestrial one, or one or more buildings or structures, whether terrestrial or maritime (such as ships or the area surrounding one or more ships). A mobile zone, such as a convoy, whether terrestrial or maritime, may also be considered.

[0012] The air target simulation system is therefore particularly suitable to be part of a test system intended to test a heterogeneous multi-sensor system (in particular, but not exclusively, for surveillance) (i.e., comprising a plurality of sensors (or detectors) employing different technologies, which use, for example, at least one radio frequency signal and one infrared signal).

[0013] More specifically, although not exclusively, an aerial target suitable for simulation by the simulation system may correspond to one of the following flying machines: - an aircraft, for example a fighter jet, an airliner or a tourist aircraft; - a glider, in particular a hypersonic glider, or an ultralight aircraft, and more generally any flying object of an aerobic type; - a missile, for example ballistic (maneuvering or not) or hypersonic or subsonic or supersonic; - a rocket.

[0014] In one particular embodiment, the aerial target can also be a moving object traveling at low speed and at a height (relative to the ground) close to 0 meters. Such a moving object could, in particular, be a ship.

[0015] Advantageously, the synchronization device is configured to synchronize the drones in the drone set, both: - in time (temporally); - in space (spatially, i.e., in position and attitude); and - to be consistent with the aerial target they simulate and to avoid risks of collision (between the drones and elements external to the system).

[0016] Furthermore, advantageously, the simulation system includes at least one of the following types of signal generator: - a radio frequency signal generator; - an infrared signal generator; - a visible signal generator; - a friendly identification signal generator.

[0017] In a preferred embodiment, the aerial target simulation system comprises a plurality of drone arrays, each of said drone arrays being configured to simulate an aerial target (different from the aerial target simulated by another drone array). This preferred embodiment thus makes it possible to simultaneously simulate a plurality of different aerial targets, such a situation corresponding, for example, to an attack scenario in which numerous enemy aerial targets (or threats) are sent at the same time to attack an area to be monitored and protected. In a particular embodiment, the aerial target simulation system comprises at least two drone arrays configured to simulate the same aerial target.

[0018] Furthermore, and advantageously, said aerial target simulation system also includes a mission management device configured to be able to communicate with drones from at least a set of drones.

[0019] Advantageously, the mission management system includes at least one of the following units: - at least one mission preparation unit; - at least one mission execution unit; - at least one mission control unit.

[0020] Furthermore, advantageously, the aerial target simulation system also includes at least one trajectory modification device configured to be able to modify (in real time) the trajectory of at least one drone. Advantageously, the aerial target simulation system includes: - at least one trajectory modification device that is part of the mission management system and is configured to issue trajectory correction commands to the drone, which are generated automatically and / or by an operator; and / or - at least one trajectory modification device that is mounted on the drone and is configured to modify the drone's trajectory.

[0021] In one particular embodiment, at least some of said drones are multicopter drones, which are very maneuverable.

[0022] The present invention also relates to a method for simulating aerial targets, said method using at least one set of drones, each of the drones being equipped with a signal generator capable of generating a signal representative of an aerial target to be simulated.

[0023] According to the invention, said method is such that: - at least one of the drones in the drone set is equipped with a signal generator of a first type and at least one other drone in the drone set is equipped with a signal generator of a second type different from the first type; and - all the drones in the drone set are synchronized to simulate one and the same target.

[0024] Advantageously, the drones in the drone set are synchronized, both: - in time; - in space; and - to be consistent with the aerial target they simulate, and to avoid risks of collision (between the drones and elements external to the system).

[0025] The present invention further relates to a test system for testing a surveillance system (of an area), in particular of a heterogeneous multi-sensor weapon system, which includes said surveillance system and at least one aerial target simulation system such as that described above.

[0026] Advantageously, the surveillance system includes as a sensor, at least one of the following: a radar, an optical sensor (infrared, TV or other), and for example a goniometer, a cooperative sensor (part of an identification friend or foe device, for example of type IFF (for "Identification Friend or Foe" in English) or infodrone, ADSB, … or a communication simulation system (for ELINT systems)).

[0027] The present invention further relates to a heterogeneous multi-sensor weapon system comprising at least one test system as mentioned above.

[0028] The said air target simulation system and / or said test system can be used in many different applications, and in particular: - for training, in particular of operators of the surveillance system and / or the weapon system; - for training, in particular of operators of the surveillance system and / or the weapon system; - for calibration of the surveillance system and / or the weapon system; - for testing of the surveillance system and / or the weapon system; - for validation of the surveillance system and / or the weapon system; and - for demonstration.

[0029] The present invention generally allows testing of the complete chain of a weapon system, from detection to engagement (excluding missiles in flight), and thus at least one of the following characteristics: - the surveillance, detection and tracking capability of sensors; - the proper behavior of the weapon system algorithms that perform data fusion, data processing for threat assessment, engagement planning, etc.; and - the engagement chain with the proper functioning of the algorithms and sensors during this phase. Brief description of the figures

[0030] The accompanying figures will clearly illustrate how the invention can be implemented. In these figures, identical reference numerals designate similar elements.

[0031] Lare represents schematically a first particular embodiment of an aerial target simulation system that is part of a test system.

[0032] This is the synoptic diagram of a drone that is part of the aerial target simulation system.

[0033] This is the synoptic diagram of a mission management device that is part of the aerial target simulation system.

[0034] Lare represents schematically a second particular embodiment of an aerial target simulation system that is part of a test system.

[0035] Lare represents schematically a third particular embodiment of an aerial target simulation system that is part of a test system.

[0036] This is the synoptic diagram of a process for simulating aerial targets.

[0037] This is the synoptic diagram of a radio frequency generator that is part of the aerial target simulation system. Detailed description

[0038] System 1 (for simulating aerial targets) which illustrates the invention and is schematically represented in particular embodiments in Figures 1, 4 and 5 is intended to simulate aerial targets 2.

[0039] Although not exclusively, this system 1 (for simulating aerial targets) may be part of a test system 9 intended to test a surveillance system 3 of at least one area (hereinafter "surveillance system 3"). The surveillance system 3 is preferably a heterogeneous multi-sensor surveillance system, that is, one that includes a plurality of heterogeneous (i.e., different types) sensors (or detectors). In the example shown, the surveillance system 3 includes, in particular, a radar 4 and an infrared sensor (or imager) 5. The surveillance system 3 may also include other sensors such as a direction finder or an identification friend or foe device, as specified below.

[0040] The surveillance system 3 is designed to monitor a specific geographical area around its installation. This geographical area is preferably a land-based area, but can also be, at least partially, a maritime area. It may include a site, a building, one or more ships, or one or more vehicles. A mobile area, such as a land or sea convoy, can also be considered.

[0041] In one particular embodiment, the surveillance system 3 is part of a weapon system 6, which is intended, for example, to protect this geographical area, and which includes, in addition to the surveillance system 3, weapons (not shown) enabling, in particular, the neutralization of hostile aircraft (specifically hostile aircraft detected by the surveillance system 3). In this case, the test system 9 is intended to test the surveillance system 3 and / or the various components of the weapon system 6, including sensors allocated solely to the engagement chain, for example.

[0042] The surveillance system 3 can therefore be deployed on land (at a fixed location, or mobilely on a land vehicle), or at sea (on a ship, military or civilian). It can also be used for non-military systems, for example an anti-drone system for a sensitive civilian site such as a power plant, an airport sensor network, etc.

[0043] In the context of the present invention, "simulating an aerial target" means generating and emitting signals, specified below, which make a surveillance system, such as surveillance system 3, believe that these signals come from a real aerial target.

[0044] Aerial targets (identified by a reference number 2, to which the letters A, B, C, and D have been added in the figures to differentiate them) are represented by hatched lines in Figures 1, 4, and 5 to clearly indicate that they are simulated and therefore virtual, and do not correspond to a real aerial object. These aerial targets 2 can represent any flying object that one wishes to simulate, and in particular a hostile (or enemy) object or aircraft. This could include, for example, a military aircraft, as in the example in Figures 1, 4, and 5, or a drone (not shown), a helicopter (not shown), or a missile (not shown).

[0045] More generally, within the framework of the present invention, an aerial target 2 may correspond to at least one of the following flying machines: - an aircraft, for example a fighter jet, an airliner or a tourist aircraft; - a glider, in particular a hypersonic glider, or an ultralight aircraft, and more generally any flying object of the aerobic type; - a missile, for example ballistic (maneuvering or not) or hypersonic or subsonic or supersonic; - a rocket.

[0046] In one particular embodiment, the aerial target can also be a moving object traveling at low speed and at a height (relative to the ground) close to 0 meters. Such a moving object could, in particular, be a ship.

[0047] System 1 comprises, as shown in Figure 1, at least one set 7 of drones. Set 7 comprises a plurality of drones 8. To differentiate the drones 8 from each other, the letters A, B, … have been added to the reference 8 in Figures 1, 4 and 5.

[0048] In one particular embodiment, each set 7 of drones comprises a pair of drones (namely two drones such as drones 8A and 8B of set 7 of the). Of course, it is also conceivable that set 7 of drones comprises more than two drones 8, for example three or four drones, as specified below with reference to the example of the.

[0049] A drone 8, i.e., an unmanned aerial vehicle (UAV) belonging to system 1, is shown schematically on the diagram as a non-limiting illustration. All drones 8A, 8B, …, 8J of system 1 can correspond to this drone 8. The drone 8 includes common means 10 (in particular means of lift (rotating wings 10A of drone 8A), …) and means of generating a forward force), which are shown schematically on the diagram and are configured to enable the drone 8 to fly.

[0050] Drone 8 includes other equipment specified below.

[0051] Each of the drones 8 in the set 7 of system 1 is equipped with a signal generator 11 or 12 capable of emitting a signal representative of an aerial target 2 to be simulated,

[0052] According to the invention, for each set 7 of drones, one of the drones in the set 7 of drones is equipped with a signal generator of a first type, such as for example the drone 8A of laqui is equipped with an infrared signal generator 12, and another drone in the set 7 of drones is equipped with a signal generator of a second type (different from the first type), such as for example the drone 8B of laqui is equipped with a radio frequency signal generator 11.

[0053] In the illustrative and non-limiting examples shown in the figures, radio frequency signal generators 11 and infrared signal generators 12 are shown, associated respectively with radars 4 and infrared sensors (or imagers) 5.

[0054] However, within the scope of the present invention, system 1: - may include, in addition to or instead of one or more radio frequency signal generators and / or one or more infrared signal generators, one or more visible signal generators and / or one or more friend identification signal generators and / or one or more communication signal generators (for direction finding, but also electronic intelligence (ELINT)); - may be associated with many types of sensors, and in particular with: • radars; • optical sensors, of infrared, TV or other type, and also with direction finders; • cooperative sensors (part of an identification friend or foe device for example of IFF (Identification Friend or Foe) or infodrone type, or ADSB, … or an ELINT system).

[0055] In addition, system 1 includes a synchronization device 14 () configured to synchronize the drones 8 of the set 7 of drones so that they simulate a single aerial target 2, as in the example of the.

[0056] More specifically, the synchronization device 14 is configured to synchronize the drones of the set 7 of drones, both:- in time (temporally);- in space (spatially); and- to be consistent with respect to the aerial target 2 which they simulate, and to avoid risks of collision between the drones 8 and elements external to the system 1.

[0057] The synchronization device 14 also synchronizes the payloads so that they are synchronized in time and in terms of parameters (which are linked to each type of payload).

[0058] The synchronization device 14 is part of a mission management device 13, shown schematically in the figure. The mission management device 13, which is part of system 1, is capable of communicating with each of the drones 8 in the set 7 of drones 8.

[0059] To achieve this, the device 13 includes a transmitting / receiving unit 15 ( ) which cooperates with a transmitting / receiving unit 16 ( ) of the drone 8 with which it wishes to communicate. The transmitting / receiving units 15 and 16 are capable of exchanging information, via the transmission and reception of electromagnetic waves, as illustrated by the double dashed arrows 17 in Figures 1 to 5.

[0060] Thus, system 1 is capable of generating, via at least two drones 8, such as drones 8A and 8B, signals of different types (for example, at least one radio frequency signal and at least one infrared signal). Furthermore, the drones 8 are synchronized so that the signals of different types can simulate a single aerial target, such as aerial target 2A.

[0061] If system 1 is part of a test system 9, it is thus able to test both a radar 4 and an infrared sensor 5 of the surveillance system 3, i.e., detection means of different types. It also allows for testing detection means (radar 4 and infrared sensor 5) located in different places on the same site.

[0062] In a preferred embodiment, the drone 8 is also equipped with a central unit 18, as shown in the.

[0063] In one particular embodiment, the central unit 18 (or computer) is specifically capable of automatically determining guidance commands used by the means 10 to guide the drone 8. The drone 8 can thus be guided automatically without (or with limited) operator intervention, for example, to avoid a collision with another drone and simply to fulfill its mission, since it is the central unit 18 that periodically sends commands to the means 10 to ensure the simulated trajectory is correct. More precisely, the central unit 18 sends commands to the autopilot (which is installed on the flight control computer), and the autopilot then sends the commands to the means 10.

[0064] The drone 8 can therefore fly autonomously in this particular embodiment.

[0065] The central unit 18 is also configured to generate commands to the signal generator 11, 12 so that it emits the appropriate signal.

[0066] Furthermore, in a particular embodiment, the drone 8 also includes a transmitting / receiving unit 19 which cooperates with a transmitting / receiving unit 19 of another drone 8 with which it wishes to communicate. The transmitting / receiving units 19 of two drones 8 (or of all the drones 8 of the assembly 7 or of all the drones 8 of the system 1) are thus capable of exchanging information, via the transmission and reception of electromagnetic waves, as illustrated by the double dashed arrows 24 in Figures 1, 2 and 5.

[0067] Exchanges between two drones 8 can be implemented in two ways: - either directly between the drones 8 via their transmitting / receiving units 19. In this case, exchanges can also be carried out with the device 13 on the ground (if it is provided); - or by going through the device 13 on the ground (which serves as a router).

[0068] Ideally, the information exchanged aims to prevent a collision between the two drones. To do this, the drones inform each other of their actual positioning.

[0069] This positioning information can also be used to correct the positioning of the drones in real time so that they remain representative of a target. For example, if drone 8A deviates from its trajectory, for instance due to wind, the computer 18 of drone 8B will correct the trajectory of drone 8B to maintain consistent target behavior.

[0070] Furthermore, in a particular embodiment, the drone 8 is equipped with a positioning device 31 configured to determine the (geographic) position of the drone 8 in space. Preferably, the positioning device 31 uses a satellite positioning system, for example of the GNSS (Global Navigation Satellite System) type, to which it adds a solution for improving localization accuracy, such as, for example, a real-time kinematic technique of the RTK (Real-Time Kinematic) type.

[0071] Furthermore, in a preferred embodiment, at least some of the drones 8 of system 1, and preferably all of the drones 8 of system 1, are multicopter or multirotor drones, i.e. drones with more than two rotating wings 10A ( ), i.e. more than two lift-generating rotors, and for example four, six or eight rotating wings 10A. This makes use of highly maneuverable drones 8, which are capable of following all desired trajectories, including complex trajectories.

[0072] Each drone 8 and the signal generator 11, 12 mounted on this drone 8 are controlled by the central unit 18 which is an on-board computer.

[0073] Furthermore, they are: - either connected to the mission management system 13 (located, for example, on the ground), via a specific link, as illustrated by the double dashed arrows 17 in Figures 1 to 5; - or autonomous. In this case, it is planned that a pilot can take over if necessary.

[0074] In both cases, they can also be directly linked to other drones by a specific link, as illustrated by the double arrows 24 in dotted lines on figures 1, 2 and 5.

[0075] As for the mission management device 13, it is preferably installed on the ground. In an alternative embodiment detailed below, it can also be installed on a ship. Consequently, the actions described below, which are performed by an operator from the ground, could also be performed by an operator on a ship.

[0076] The mission management system 13, and in particular one or more mission execution units 21, can be used by one or more operators to control the drones from the ground or from a ship during a mission execution phase, as specified below. Preferably, though not exclusively, a single operator is planned. However, one operator per drone of system 1 may also be provided.

[0077] The mission management system 13 includes, as shown on the: - at least one mission preparation unit 20; - at least one mission execution unit 21; - at least one mission control unit 22.

[0078] The mission preparation unit 20 of the mission management device 13 is used by an operator to prepare the mission (for simulation of aerial targets and more generally for testing) and in particular to define the trajectory of the drones 8, the trajectory of the aerial target or aerial targets and the characteristics of the signal emitted by the generator 11, 12 of each of the drones 8.

[0079] Unit 20 also carries out a phase of positioning the sensors (on fixed ground), defining the flight zones, and verifying the consistency of the drone trajectories, and fine-tuning the trajectory of the aerial targets relative to the position of the sensors.

[0080] Mission execution unit 21 of mission management system 13 is intended for the implementation of the mission (simulation of aerial targets and more generally of testing).

[0081] As for the mission control unit 22 of the mission management device 13, its purpose is to control the mission during its execution. To this end, the mission control unit 22 includes (or is associated with) at least one trajectory modification device 23, which is configured to modify the trajectory of at least one drone 8, as specified below. If the trajectory modification device 23 is used to modify the trajectory of the simulated target, it must modify (via the link 17) the trajectory of all the drones 8 (simulating this target) and all the corresponding signal generators in order to continue to simulate the target correctly.

[0082] System 1, as described above, enables the implementation of a method P for simulating aerial targets. This method P includes, as shown in the figure, a mission preparation step E1 and a mission execution step E2, during which a mission control sub-step E2A is implemented.

[0083] During the E1 mission preparation stage, an operator uses the mission preparation unit 20 to define mission parameters, and in particular to define: - the characteristics enabling unit 20 to determine the trajectory to be followed by each drone 8 of system 1, which will be used during the execution of the mission; and - the characteristics of the signal that will be emitted by the generator (radio frequency or infrared) 11, 12 of each drone 8 of system 1.

[0084] The mission parameters, and in particular the trajectory of the drones and the aerial target or targets to be simulated and the characteristics of the signal to be emitted, determined during the preparation of the mission, are recorded:- in a database 29 of the device 13, and for example of the unit 21, as shown on the ; and / or- in a database 30 () of the central unit 18 of the drone 8.

[0085] During mission execution step E2, these mission parameters are transmitted to the means 10 (via the autopilot) and to the signal generator 11, 12 of the drone 8 to carry out the mission. These mission parameters are transmitted to the means 10 and the signal generator 11 or 12 either as is (if they are usable as is) via the central unit 18, or, if necessary, after processing by the central unit 18 to adapt them to commands usable by the means 10 and the signal generator 11, 12.

[0086] More specifically: - if they are recorded in the database 29 of device 13, they are transmitted to the drone 8 (and in particular to the central unit 18 drone 8) via the transmitting / receiving unit 15 of device 13 which cooperates with the transmitting / receiving unit 16 of drone 8; and - if they are recorded in the database 30, they are transmitted directly to the means 10 and to the signal generator 11, 12.

[0087] During mission execution step E2, each drone 8 of the drone array(s) 7 of system 1 is flown in close proximity (generally within 2 kilometers) to the surveillance system 3. More specifically, each drone 8 flies (autonomously or under the control of a ground operator) along its corresponding predetermined trajectory (defined by the mission parameters). Furthermore, during this flight, the signal generator 11, 12 of each drone 8 transmits the corresponding signals (radio frequency, infrared, or other) (defined by the mission parameters).

[0088] The trajectory followed and the signal emitted by each drone 8 are such that a sensor (for example, a radar 4 or an infrared sensor 5) of the surveillance system 3 believes it has detected a flying object (i.e., an aerial target 2) flying at a greater distance from the surveillance system 3, as specified below, and considers this flying object to be real. The drone 8 thus simulates an aerial target 2.

[0089] Furthermore, all drones in each set of 7 are synchronized to simulate a single aerial target. For example, in embodiment A, drones 8A and 8B in set 7 are synchronized to simulate aerial target 2A.

[0090] This synchronization involves adapting the flights of drones 8A and 8B to each other, as well as the signal emissions from signal generators 11 and 12. The drones in assembly 7 are controlled to fly and emit signals to achieve this synchronization. This synchronization of all the drones in assembly 7 is achieved both: - spatially. The drones in assembly 7 are controlled to move in space to follow prescribed trajectories so as to be at a prescribed position (on the corresponding prescribed trajectory); - temporally. The drones in assembly 7 are controlled to move in space to follow prescribed trajectories so as to be at the prescribed position at a given time; and - to be coherent with respect to the aerial target 2 that they simulate and avoid the risk of collision.

[0091] Through this (triple) synchronization, the drones in the set of 7 drones are controlled to effectively simulate a single aerial target.

[0092] During the E2 stage of mission execution, each drone 8 therefore emits a signal, either by a radio frequency generator 11, or by an infrared signal generator 12, which is intended to be detected by a corresponding sensor (for example a radar 4 or an infrared sensor 5).

[0093] More specifically, the infrared signal generator 12 is an infrared illuminator, that is, a standard device capable of emitting an infrared signal, as illustrated by a dashed arrow 25 on the diagram. The characteristics of this infrared signal, and in particular its amplitude, are determined so that the infrared signal is similar to an infrared signal (or hot spot) emitted by a real aerial target, for example, an airplane, helicopter, drone, missile, or other mobile object that one wishes to simulate. In a particular variant, the infrared signal generator 12 generates several bright spots to be as representative as possible of the target's shape. In this case, the amplitude of each bright spot is controlled.

[0094] This infrared signal, when emitted by the drone's infrared generator 12, is detected by an infrared sensor 5 of the surveillance system 3.

[0095] The infrared sensor 5 of the surveillance system 3 thus grows, by detecting this infrared signal 25 emitted by the drone 8A (), to detect a hot area of ​​a real aerial target (for example its engines or another part with a characteristic and known infrared signature) and therefore detect this real aerial target.

[0096] The central unit 18 (or, in another variant, the device 13) determines the characteristics of the infrared signal to be emitted based on the position and presentation of the simulated aerial target relative to the infrared sensor 5. This improves the representativeness of the simulated aerial target. In a simplified embodiment, the light level is assumed to remain constant.

[0097] As for the radio frequency generator 11, which is made for example from DRFM technology (for "Digital Radio Frequency Memory" in English), its purpose is in particular to simulate an aerial target for a radar 4.

[0098] To achieve this, the radio frequency generator 11 comprises, as schematically represented in Figure 1: - a detector 11A to detect an initial radio frequency signal emitted by the radar 4, as illustrated by dashed arrows 26 in Figures 1, 4, and 5. Detector 11A can also attenuate the received signal; - a processing unit 11B to determine and generate a response radio frequency signal, based on the initial radio frequency signal detected by detector 11A and the characteristics (distance from the radar, speed) of the aerial target to be simulated. To do this, processing unit 11B first converts the received signal into a digital signal, processes it, and recreates a radio frequency signal (digital-to-analog conversion).Depending on the frequency of the received signal, the processing unit 11B can also perform a transposition (frequency downsampling) to adapt to the DRFM technology, and a frequency upsampling after analog-to-digital conversion for retransmission; and - a transmitter 11C to transmit this radio frequency (response) signal to the radar 4, as illustrated by dashed arrows 27 on figures 1, 4 and 5. The transmitter 11C can also amplify or attenuate the signal if necessary.

[0099] When it detects this radio frequency (reply) signal, radar 4 believes it is detecting the echo of an aerial target and thus detecting an aerial target which has the characteristics (of distance and speed in particular) taken into account by the processing unit 11B to determine the radio frequency (reply) signal.

[0100] These characteristics taken into account by the processing unit 11B may correspond to mission parameters that are defined during mission preparation.

[0101] The surveillance system 3 (of site) may include as a sensor using a radio frequency signal, such as the radio frequency signal 27 emitted by the radio frequency signal generator 11 of the, a radar 4, but also a goniometer (not shown) or an identification friend or foe device (also not shown).

[0102] The Identification Friend or Foe (IFF) device is an identification device that allows the recognition of friendly and enemy flying objects among detected aircraft.

[0103] In an embodiment intended to emit, during step E2 of mission execution, a signal to a goniometer or a friend or foe identification device, these sensors are used in a usual way and the radio frequency generator 11 emits a signal appropriate for their use.

[0104] Therefore, system 1 is capable of simulating an aerial target which is simulated as being located at a high distance from surveillance system 3 from drones 8 flying at a much shorter distance from surveillance system 3.

[0105] By way of non-limiting illustration: - each drone 8 of system 1 can be located at a distance from the surveillance system 3, such as the distance D1 on the for drone 8B, which is between 50 meters and 2 kilometers; and - system 1 can simulate an aerial target which is located (virtually) at a distance from the surveillance system 3, such as the distance D2 on the for aerial target 2A, which is between 1 kilometer (or, at a minimum, a distance close to the distance between the drone and the surveillance system 3) and several hundred kilometers.

[0106] In the very schematic figures 1, 4 and 5, the drones and aerial targets, as well as their distances from the surveillance system 3, are not represented at the same scale for reasons of clarity in these figures.

[0107] During the E2 stage of mission execution, the central unit 18 therefore uses the trajectory (or prescribed trajectory) determined in mission preparation to send orders to the means 10 (via the autopilot) so that they fly the drone 8 as close as possible to this prescribed trajectory.

[0108] During mission execution phase E2, mission control is performed (sub-phase E2A), notably from the ground using mission control unit 22. This mission control allows, in particular, the detection of when the drone deviates from the prescribed trajectory (which it must follow).

[0109] In this case, the drone's trajectory is corrected (in real time) by a trajectory modification device so that the drone returns to the prescribed trajectory and follows it again.

[0110] In a first embodiment, the trajectory correction device 23 is part of the mission management device 13. This trajectory correction device 23 is configured to automatically detect, from the ground, a deviation from the prescribed trajectory of the drone 8, determine (trajectory correction) commands to bring the drone back onto the prescribed trajectory, and transmit these commands to the drone 8 (and in particular to the central unit 18 of the drone 8) via the transmitting / receiving unit 15 of the device 13, which cooperates with the transmitting / receiving unit 19 of the drone 8. These (trajectory correction) commands are then applied to the means 10 of the drone 8.

[0111] In a second embodiment, in addition to or as a variant of the first embodiment, the system 1 includes a trajectory modification device 28 which is mounted on the drone 8 and which is preferably integrated at least in part into the central unit 18. This trajectory modification device 28 is configured to detect on the drone 8 (in particular using the positioning device 31) a deviation between its current trajectory and the prescribed trajectory, to determine correction (trajectory) commands to bring the drone back onto the prescribed trajectory and to transmit these (trajectory correction) commands to the means 10.

[0112] This second embodiment, relating to automatic trajectory correction without intervention from the ground station (i.e., without intervention from the mission management device 13), can also be implemented in the event of a risk of collision between two drones of system 1. Such a risk may arise, in particular, when system 1 comprises a large number of drones, for example, several dozen drones, operating in a restricted geographical area. In this case, the two drones can communicate with each other, via their respective transmit / receive units 19 ( ), as illustrated by the double arrows 24 in Figures 1 and 5, or via device 13, and they can, in particular, transmit their respective positions, determined, for example, using their positioning devices 31.

[0113] In the first and second embodiments described above, the trajectory of a single drone is corrected to align with the trajectory defined during mission preparation. This implies a transitional phase during which the drones (simulating the same aerial target) are not synchronized.

[0114] Also, in an alternative embodiment of these first and second modes, the trajectories and parameters of all drones (simulating the same aerial target) are corrected simultaneously to maintain target consistency. In this alternative embodiment, the calculation can be performed on the ground (via the mission management device 13) or on board the drones (via the central unit 18).

[0115] In another embodiment, the trajectory modification device 23 of the mission management device 13 is used by an operator to modify the trajectory of the simulated aerial target in real time. Correction commands are transmitted via links 17 to all drones simulating the aerial target, in order to modify the trajectories of all drones, as well as the parameters of the signal generators used, according to the new trajectory of the simulated aerial target. This trajectory modification is performed in response to a command issued by an operator using a control device, such as a joystick, which will control the modification of the aerial target's trajectory, or to the activation by the operator of one or more different scenarios (or segments of scenarios, such as requesting a maneuver).Furthermore, the scenario can be put on hold (with the drone brought into a hover), and then can be resumed when necessary.

[0116] In the simplified example, system 1 comprises a single set 7 including two drones 8A and 8B.

[0117] Within the framework of the present invention, the system 1 may comprise a plurality of sets 7 (each of which is intended to simulate a particular aerial target), and in particular, among them, one or more sets 7 which comprise more than two drones.

[0118] Thus, in a particular embodiment, represented by way of simple non-limiting illustration on the, to simulate the same aerial target 2B, the system 1 comprises, in addition to a drone 8C equipped with a signal generator of a first type, in this case an infrared signal generator 12, and a drone 8D equipped with a signal generator of a second type (different from the first type), in this case a radio frequency signal generator 11, two additional drones each equipped with a signal generator, in this case a drone equipped 8E with an infrared signal generator 12 and a drone 8E equipped with a radio frequency signal generator 14.

[0119] In this particular embodiment, drones 8C, 8D, 8E and 8F of set 7 are synchronized to simulate aerial target 2B.

[0120] In the specific example shown, system 1 is thus able to stimulate four sensors of the surveillance system 3 (namely two radars 4 and two infrared imagers 5). It is also conceivable that the additional drone(s) could each be equipped with a signal generator of a type other than those of drones 8C and 8D. In the diagram, the links 17 that exist between the different drones 8C, 8D, 8E and 8F of the assembly 7 are not shown for the sake of simplicity in the drawing.

[0121] Furthermore, in another particular embodiment, represented on the, system 1 comprises both: - a set 7A of drones including drones 8G and 8H which are intended to simulate the same aerial target 2C, drone 8G being equipped with an infrared signal generator 12 and drone 8H being equipped with a radio frequency signal generator 11; and - a set 7B of drones including drones 8I and 8J which are intended to simulate the same aerial target 2D, drone 8I being equipped with an infrared signal generator 12 and drone 8J being equipped with a radio frequency signal generator 11.

[0122] In this particular embodiment, drones 8G and 8H of set 7A are synchronized to simulate aerial target 2C and drones 8I and 8J of set 7B are synchronized to simulate aerial target 2D.

[0123] System 1 is thus capable of simultaneously simulating two different aerial targets, 2C and 2D. In the example shown, the aerial targets 2C and 2D are represented as airplanes. Of course, the aerial targets 2C and 2D could correspond to two different types of aircraft.

[0124] More generally, system 1 is capable of simultaneously simulating more than two aerial targets and each set of drones can include two or more drones, with each set of drones having two or more different types of signal generators.

[0125] Within the framework of the present invention, the surveillance system 3 and / or the weapon system 6, for which system 1 must simulate aerial targets, can be installed in different locations. System 1 is therefore adaptable to various situations and / or to various surveillance systems 3 and / or various weapon systems 6, within the limits of the characteristics of the communication means used.

[0126] Thus, within the framework of the present invention, the sensors of system 1, such as a radar or an infrared sensor, can be installed in a fixed position on the ground. They can also be mounted on a mobile device, for example a land vehicle, a ship, or a static flying device such as a balloon tethered to the ground by a tether.

[0127] In a preferred embodiment, the surveillance system 3 and the weapon system 6 (which includes the surveillance system 3) are installed on the ground (not shown) and represent ground-to-air (defense) systems.

[0128] In a first embodiment variant, the surveillance system 3 and the weapon system 6 comprising the surveillance system 3 can be installed (or mounted) on one or more ships (not shown) and represent sea-to-air (defense) systems.

[0129] In addition, in a second embodiment variant, for example at a port, part of the surveillance system 3 and / or the weapon system 6 can be installed on the ground (not shown) and the rest of the surveillance system 3 and / or the weapon system 6 can be installed on one or more ships (not shown).

[0130] System 1, as described above, offers numerous advantages. In particular, this system 1 is capable of: - simultaneously simulating many aerial targets; - simulating the same aerial target to simultaneously stimulate a plurality of sensors, and more specifically sensors of different types; - simulating any type of aerial target (or flying machine), such as, for example, an airplane, a helicopter, a drone, a missile, etc.; and - simulating aerial targets flying along any type of trajectory.

[0131] Test system 9 is thus able to test the complete chain of weapon system 6, from detection to engagement (excluding missiles in flight), and thus at least one of the following characteristics: - the surveillance, detection and tracking capability of sensors; - the proper behavior of the weapon system algorithms which perform data fusion, data processing for threat assessment, engagement plan, etc.; and - the engagement chain with the proper functioning of the algorithms and sensors during this phase.

[0132] System 1 and / or test system 9 can be used in many different applications, and in particular: - for training, especially of operators of surveillance system 3 and / or weapon system 6; - for training, especially of operators of surveillance system 3 and / or weapon system 6; - for calibration of surveillance system 3 and / or weapon system 6; - for testing of surveillance system 3 and / or weapon system 6; - for validation of surveillance system 3 and / or weapon system 6; and - for demonstration.

Claims

A system for simulating at least one aerial target, said system (1) comprising at least one set (7) of drones (8A to 8J), each of said drones (8A to 8J) being equipped with a signal generator (11, 12) capable of emitting a signal representative of an aerial target (2A to 2D) to be simulated, characterized in that at least one of said drones in the set (7) of drones (8A to 8J) is equipped with a signal generator (11) of a first type and at least one other drone in the set (7) of drones (8A to 8J) is equipped with a signal generator (12) of a second type different from said first type and in that said system (1) includes a synchronization device (14) configured to synchronize the drones in the set (7) of drones so that they simulate one and the same target (2A to 2D). System according to claim 1, characterized in that the synchronization device (14) is configured to synchronize the drones (8A to 8J) of the set (7) of drones, both:- in time;- in space; and- to be coherent with respect to the aerial target (2A to 2D) which they simulate and to avoid risks of collision. System according to any one of claims 1 and 2, characterized in that it comprises at least one of the following types of signal generator: a radio frequency signal generator (11); an infrared signal generator (12); a visible signal generator. System according to any one of the preceding claims, characterized in that it comprises a plurality of sets (7A, 7B) of drones, each of said sets (7A, 7B) of drones being configured to simulate an aerial target (2C, 2D). System according to any one of the preceding claims, characterized in that it comprises at least two sets of drones configured to simulate the same aerial target. System according to any one of the preceding claims, characterized in that it comprises a mission management device (13) configured to be able to communicate with drones from at least one set (7) of drones. System according to claim 6, characterized in that the mission management device (13) comprises at least one of the following units: - at least one mission preparation unit (20); - at least one mission execution unit (21); - at least one mission control unit (22). System according to any one of the preceding claims, characterized in that it comprises at least one trajectory modification device (23, 28) which is configured to modify the trajectory of at least one drone. System according to claim 8, characterized in that it comprises at least one trajectory modification device (23) which is part of the mission management device (13) and which is configured to issue trajectory correction commands to the drone (8), which are generated automatically and / or by an operator. System according to any one of claims 7 and 8, characterized in that it comprises at least one trajectory modification device (28) which is mounted on the drone (8) and which is configured to modify the trajectory of said drone (8). System according to any one of the preceding claims, characterized in that at least some of said drones (8A to 8J) are multicopter drones. Method for simulating aerial targets, said method (P) using at least one set (7) of drones, each of said drones (8A to 8J) being equipped with a signal generator (11, 12) capable of generating a signal representative of an aerial target (2A to 2D) to be simulated, characterized in that at least one of the drones in the set (7) of drones is equipped with a signal generator (11) of a first type and at least one other drone in the set (7) of drones (8A to 8J) is equipped with a signal generator (12) of a second type different from said first type, and in that said drones in the set (7) of drones (8A to 8J) are synchronized to simulate one and the same aerial target (2A to 2D). Method according to claim 12, characterized in that the drones (8A to 8J) of the set (7) of drones are synchronized, both:- in time;- in space; and- to be coherent with respect to the aerial target (2A to 2D) which they simulate and to avoid risks of collision. Test system for testing a surveillance system, in particular a heterogeneous multi-sensor weapon system, characterized in that it comprises said surveillance system (3) and at least one aerial target simulation system (1) according to any one of claims 1 to 11. System according to claim 14, characterized in that the monitoring system (3) comprises as a sensor, at least one of the following elements: a radar (4); an optical sensor (5); a cooperative sensor.

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