Method for an aerial target simulation system.

Abstract

Method and system for simulating aerial targets. The aerial target simulation system (1) comprises at least one set (7) of drones (8A, 8B), at least one (8B) of the drones in the set (7) being equipped with a signal generator (11) of a first type and at least one other drone (8A) in the set (7) being equipped with a signal generator (12) of a second type, said system (1) comprising a synchronization device configured to synchronize the drones (8A, 8B) in the set (7) so that they simulate a single target (2A), said system (1) thus enabling the testing of sensors (4, 5) of different types of a surveillance system (3) and being particularly suitable for inclusion in a test system (9) intended for testing a heterogeneous multi-sensor surveillance system (3). Figure for the abstract: Fig 1.

Description

Title of the invention: Method and system for simulating aerial targets. technical field

[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] A method and system for testing radar systems are known from document EP3 296 760 B1. This test system comprises a drone that is flown in the vicinity of the radar system to be tested. This 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 toward the radar. This radar response signal is shaped 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 being able to test only 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 solely radar systems. The aforementioned standard test system is therefore not capable of testing a surveillance system, such as those currently in general use, particularly one of the heterogeneous multi-sensor type.

[0006] There is therefore a need to have a system available to help test a surveillance system, including in particular means (or sensors) for detecting aerial targets of different types. Description of the invention

[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 of the drones 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 set drones 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 of the set of drones 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 can be used to simulate a single aerial target.

[0010] Thus, if this air target simulation system is used to test a system, particularly a surveillance system and / or the various components of a weapon system, it is capable of testing different sensors (or detection means), for example, a radar and an infrared sensor, of that system. Furthermore, it allows for testing detection means (or sensors) located in different places within the same area. It is also capable of testing sensors located in multiple areas. By way of illustration, the sensors can be mounted in a fixed position (permanently), or deployed on vehicles or ships (not permanently), for example, 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 an 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 for being 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 light 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 a particular embodiment, the aerial target may also correspond to a mobile object moving at a low speed and at a height (relative to the ground) close to 0 meters. Such a mobile object may, in particular, correspond to a ship.

[0015] Advantageously, the synchronization device is configured to synchronize the drones of 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 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, said aerial target simulation system comprises a plurality of drone sets, each of said drone sets being configured to simulate an aerial target (different from the aerial target simulated by another drone set). 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, said aerial target simulation system comprises at least two drone sets configured to simulate the same aerial target.

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

[0019] Advantageously, the mission management system comprises 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, said 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 trajectory of said drone.

[0021] In a 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 array is equipped with a signal generator of a first type and at least one other drone in the drone array is equipped with a signal generator of a second type different from the first type; and - all drones in the drone set are synchronized to simulate a single 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 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 the IFF (Identification Friend or Foe) type or of infodrone, ADSB, .... or of a communication simulation system (for ELINT systems)).

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

[0028] 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 for operators of the surveillance system and / or the weapon system; - for calibrating the surveillance system and / or the weapon system; - for testing the surveillance system and / or the weapon system; - for the validation of the surveillance system and / or the weapon system; and - for a demonstration.

[0029] The present invention makes it possible, in general, to test 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 monitoring, detection and tracking capabilities of sensors; - the proper functioning of the weapon system's algorithms that perform data fusion, data processing for threat assessment, engagement planning, etc.; and - the chain of engagement 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] Fig. 1 schematically represents a first particular embodiment of an aerial target simulation system forming part of a test system.

[0032] Fig. 2 is the synoptic diagram of a drone forming part of the aerial target simulation system.

[0033] Fig. 3 is the synoptic diagram of a mission management device forming part of the air target simulation system.

[0034] Fig. 4 schematically represents a second particular embodiment of an aerial target simulation system forming part of a test system.

[0035] Fig. 5 schematically represents a third particular embodiment of an aerial target simulation system forming part of a test system.

[0036] Fig. 6 is the synoptic diagram of a method for simulating aerial targets.

[0037] Figure 7 is the block diagram of a radio frequency generator forming part of the aerial target simulation system. Detailed description

[0038] The 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 type surveillance system, that is to say, one which includes a plurality of heterogeneous (i.e., of different types) sensors (or detectors). In the example of [Fig. 1], 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 intended to monitor a specific geographical area around its installation. This geographical area is preferably a terrestrial area, but may also be, at least in part, a maritime area. It may, in particular, be a site, a building, or one or more ships or vehicles. A mobile area such as a convoy, whether on land or at sea, may also be considered.

[0041] In a 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 flying machines (especially hostile flying machines 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 chains 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 (in a fixed position, 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 2, to which the letters A, B, C, D have been added in the figures to differentiate them from each other) are represented in lines The hatched areas in Figures 1, 4, and 5 clearly indicate that these targets are simulated and therefore virtual, and do not correspond to a real aerial object. These aerial targets can represent any flying object that one wishes to simulate, and in particular a hostile (or enemy) object or aircraft. This could include 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 light 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.

[0046] In a particular embodiment, the aerial target may also correspond to a mobile object moving at a low speed and at a height (relative to the ground) close to 0 meters. Such a mobile object may, in particular, correspond to a ship.

[0047] System 1 comprises, as shown in [Fig. 1], at least one set 7 of drones. Set 7 comprises a plurality of drones 8. To differentiate the drones 8 from one another, 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 in [Fig. 1]). Of course, it is also conceivable that the set 7 of drones comprises more than two drones 8, for example three or four drones, as specified below with reference to the example in [Fig. 4].

[0049] Figure 2 shows, by way of non-limiting illustration, a drone 8, i.e., an unmanned aerial vehicle, forming part of system 1. All drones 8A, 8B, ..., 8J of system 1 can correspond to this drone 8 of Figure 2. The drone 8 comprises common means 10 (in particular means of lift (rotating wings 10A of the drone 8A (Fig. 1), ...) and means of generating a forward force), which are shown schematically in Figure 2 and which are configured to make the drone 8 fly.

[0050] Drone 8 includes other equipment specified below.

[0051] Each of the drones 8 of the assembly 7 of the 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 drone 8A in [Fig.1] which 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 drone 8B in [Fig.1] which 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 friendly identification signal generators and / or one or more communication signal generators (for direction finding, but also electronic eavesdropping of the ELINT type); - can be associated with many types of sensors, including: • radars; • optical sensors, such as infrared, TV or other types, and also goniometers; • cooperative sensors (part of an identification friend or foe system for example of type IFF (for "Identification Friend or Foe" in English) or infodrone, or ADSB, .... or of an ELINT system).

[0055] In addition, the system 1 includes a synchronization device 14 ([Fig.3]) 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 [Fig.1].

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

[0058] The synchronization device 14 is part of a mission management device 13, shown schematically in [Fig. 3]. The mission management device 13 mission which is part of system 1 is capable of communicating with each of the 8 drones of the set 7 of drones 8.

[0059] To this end, the device 13 comprises a transmitting / receiving unit 15 ([Fig. 3]) which cooperates with a transmitting / receiving unit 16 ([Fig. 2]) 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, the system 1 is capable of generating, via at least two drones 8, such as drones 8A and 8B of [Fig. 1], 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 make it possible to simulate a single aerial target, such as aerial target 2A of [Fig. 1].

[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 provided with a central unit 18, as shown in [Fig.2].

[0063] In a particular embodiment, the central unit 18 (or computer) is notably 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 intervention (or with limited intervention) from an operator, 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 that 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 it is the autopilot that sends the commands to the means 10.

[0064] The drone 8 can thus 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 transmission and reception. of electromagnetic waves, as illustrated by double arrows 24 in dotted lines on 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 provided); - either by going through device 13 on the ground (which acts as a router).

[0068] Preferably, the information exchanged is intended to prevent a collision between the two drones. To this end, the drones inform each other of their actual positioning.

[0069] This positioning information can also be used to correct the positioning of the drones 8 in real time so as to remain representative of a target. Thus, 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 ([Fig.2]) 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 ([Fig.1]), 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 able to follow all desired trajectories, and in particular 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] In addition, they are: - either connected to the mission management device 13 (located for example on the ground), and this by a specific link, as illustrated by the double arrows 17 in dotted lines on 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 connected to other drones by a specific link, as illustrated by the double arrows 24 in dashed 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 specified 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, although not exclusively, a single operator is provided. However, one operator per drone of system 1 may also be provided.

[0077] The mission management device 13 comprises, as shown in [Fig.3]: - 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] With unit 20 is also carried out a phase of positioning of the sensors (on fixed ground), of defining the flight zones, and of verifying the consistency of the trajectories of the drones, and of fine calibration of the trajectory of the aerial targets in relation to the position of the sensors.

[0080] The mission execution unit 21 of the mission management device 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 correctly simulate the target.

[0082] The system 1, as described above, allows the implementation of a method P for simulating aerial targets. This method P comprises, as shown in [Fig. 6], in particular a mission preparation step E1 and a mission execution step E2, during which a mission control substep E2A is implemented.

[0083] During the mission preparation step 11, 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 which 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 mission preparation, are recorded: - in a database 29 of device 13, and for example of unit 21, as shown in [Fig. 3]; and / or - in a database 30 ([Fig.2]) of the central unit 18 of the drone 8.

[0085] During step E2 of mission execution, these mission parameters are transmitted to the means 10 (via the autopilot) and to the signal generator 11, 12 of the drone 8 to implement 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 step E2 of mission execution, each drone 8 of the drone set(s) 7 of system 1 is flown in close proximity (generally at a distance of less than 2 kilometers) to the surveillance system 3. More specifically, each drone 8 flies (autonomously or under the control of a ground operator) along the corresponding predetermined trajectory (defined by the mission parameters). Furthermore, during this flight, the signal generator 11, 12 of each drone 8 emits the corresponding signals (radio frequency or 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 7 of drones are synchronized to simulate a single aerial target. For example, in the embodiment of [Fig. 1], drones 8A and 8B in set 7 are synchronized to simulate aerial target 2A.

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

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

[0092] During step E2 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 conventional device capable of emitting an infrared signal, as illustrated by a dashed arrow 25 in [Fig. 1]. 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, a helicopter, a drone, a missile, or other mobile object that one wishes to simulate. In a particular embodiment, the infrared signal generator 12 generates several bright spots to be as representative as possible. possible depending on the shape of the target. In this case, each light point is controlled by amplitude.

[0094] This infrared signal, when emitted by the infrared generator 12 of the drone, is detected by an infrared sensor 5 of the monitoring 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 ([Fig.1]), to detect a hot area of ​​a real aerial target (for example its engines or another part having a characteristic and known infrared signature) and therefore to 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 as a function of 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 a 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 [Fig.7]: - 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 1 IA can also attenuate the received signal; - a processing unit 1 IB 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, the 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 1 IB can also perform a transposition (frequency downsampling) to adapt to DRFM technology, and a frequency upsampling after analog-to-digital conversion for retransmission; and - a transmitter 1 IC to transmit this radio frequency (response) signal to the radar 4, as illustrated by dashed arrows 27 in figures 1, 4 and 5. The transmitter 1 IC can also amplify or attenuate the signal if required.

[0099] When it detects this radio frequency (reply) signal, the radar 4 believes it is detecting the echo of an aerial target and thus detecting an aerial target which has the characteristics (in particular of distance and speed) taken into account by the processing unit 1 IB to determine the radio frequency (reply) signal.

[0100] These characteristics taken into account by the processing unit 1 IB may correspond to mission parameters which are defined during mission preparation.

[0101] The site surveillance system 3 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 [Fig.1], 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 device (or IFF for "Identification Friend or Foe" in English) is an identification device which makes it possible to recognize, among detected flying machines, friendly flying machines and enemy flying machines.

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

[0105] By way of non-limiting illustration: - each drone 8 of system 1 can be located at a distance from the monitoring system 3, such as the distance DI on [Fig. 1] 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 [Fig.1] 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 the aerial targets, as well as their distances from the surveillance system 3, are not represented at the same scale for reasons of clarity of these figures.

[0107] During step E2 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 step E2, mission control is performed (in mission control substep E2A), notably from the ground using mission control unit 22. This mission control makes it possible, in particular, to detect 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 collisions 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 ([Fig. 2]), as illustrated by the double arrows 24 in Figures 1 and 5, or via the 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 a variant of these first and second embodiments, the trajectories and parameters of all drones (simulating the same aerial target) are corrected simultaneously in order to always maintain the consistency of the target. In In this variant of implementation, the calculation can be done 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 the links 17 to all the drones simulating the aerial target, in order to modify the trajectories of all the 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 carried out in response to a command issued by an operator using a control device, in particular a manual one 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, for example, to perform a maneuver).Furthermore, the scenario can be put on hold (with the drone hovering), and then resumed when necessary.

[0116] In the simplified example of [Fig.1], system 1 comprises a single assembly 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 in [Fig.4], 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 8E equipped with an infrared signal generator 12 and a drone 8E equipped with a radio frequency signal generator 14.

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

[0120] In the particular example of [Fig. 4], 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 [Fig. 4], the links 17 that exist between the different Drones 8C, 8D, 8E and 8F from set 7 are not shown for the sake of simplifying the drawing.

[0121] Furthermore, in another particular embodiment, shown in [Fig. 5], system 1 comprises both: - a set 7A of drones comprising 8G and 8H drones which are intended to simulate the same aerial target 2C, the 8G drone being equipped with an infrared signal generator 12 and the 8H drone being equipped with a radio frequency signal generator 11; and - a set 7B of drones comprising drones 81 and 8J which are intended to simulate the same 2D aerial target, drone 81 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 81 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 of [Fig. 5], the aerial targets 2C and 2D are represented as airplanes. Of course, the aerial targets 2C and 2D can correspond to two flying machines of different types.

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

[0125] Within the scope of the present invention, the surveillance system 3 and / or the weapon system 6, for which the system 1 must simulate aerial targets, can be installed in different locations. The 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 attached 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, 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] Furthermore, in a second embodiment, 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, has many advantages. In particular, this system 1 is able to: - to simulate, simultaneously, numerous aerial targets; - to simulate the same aerial target to simultaneously stimulate a plurality of sensors, and more particularly sensors of different types; - to simulate all types of aerial targets (or flying machines), such as, for example, an airplane, a helicopter, a drone, a missile, ...; and - to simulate aerial targets flying along any type of trajectory.

[0131] The test system 9 is thus able to test the complete chain of the weapon system 6, from detection to engagement (excluding missiles in flight), and thus at least one of the following characteristics: - the monitoring, detection and tracking capabilities of sensors; - the proper functioning of the weapon system's algorithms that perform data fusion, data processing for threat assessment, engagement planning, etc.; and - the chain of engagement 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, in particular for operators of the surveillance system 3 and / or the weapon system 6; - for training, in particular for operators of the surveillance system 3 and / or the weapon system 6; - for the calibration of the surveillance system 3 and / or the weapon system 6; - for testing of the surveillance system 3 and / or the weapon system 6; - for the validation of the surveillance system 3 and / or the weapon system 6; and - for a demonstration.

Claims

Demands

1. 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) comprises a synchronization device (14) configured to synchronize the drones in the set (7) of drones so that they simulate a single target (2A to 2D).

2. 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.

3. 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; - a friendly identification signal generator.

4. 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).

5. A 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.

6. System according to any one of the preceding claims, characterized in that it includes a mission management device (13) configured to be able to communicate with drones from at least a set (7) of drones.

7. 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).

8. 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.

9. 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.

10. 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).

11. System according to any one of the preceding claims, characterized in that at least some of said drones (8A to 8J) are multicopter drones.

12. 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).

13. 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 consistent with the aerial target (2A to 2D) that they simulate and to avoid risks of collision.

14. 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.

15. 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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