Method and device for determining an engagement plan for an air defense system

Abstract

- Method and device for determining an engagement plan for an air defense system. - The device determines, using a processing unit, an engagement plan for an air defense system (2) comprising munitions (Mj) fired from launchers (4), the processing unit determining the engagement plan by implementing an auction algorithm taking into account, on the one hand, the number of munitions (Mj) from the launcher (4) representing a first constraint concerning the munitions (Mj) from the launcher (4), and on the other hand, a number of firing dates in availability windows representing a second constraint concerning the firing dates, the engagement plan comprising, for each target (Ci), the allocation of, on the one hand, a particular munition (Mj) from a particular launcher (4) and, on the other hand, a firing date for this munition (Mj), this allocation satisfying the said first and second constraints.

Description

Domain technical

[0001] The present invention relates to a method and a device for determining an engagement plan for an air defense system, as well as to a method and a system for processing air threats in the military field comprising, respectively, such a method and such a device. In the state of the art, such methods, devices and systems are for example known from document US 6,497,169 B1. State of the art

[0002] The present invention applies to the military field, and more precisely to an allocation of munitions, namely mainly missiles, to aerial targets (or threats) ("Weapon Target Assignment" in English). In a military context, the defense of an area against an enemy air offensive, sometimes with a high number of aerial threats representing a saturating attack, requires rapid and optimized processing in order to best allocate the available missiles to deal with the threats while maximizing the survival expectancy of the defended strategic points.

[0003] Depending on the threats, an engagement plan is generally determined taking into account operational and technical criteria.

[0004] Determining the engagement plan depends not only on allocating available missiles to targets, but also on choosing the date for launching these missiles. Such a determination can be very complicated due to the many constraints and uncertainties that exist in a complex situation of this type.

[0005] There are, in particular, constraints linked to the fact that a launcher can be equipped with several missiles and that a certain preparation time is necessary between the successive firings of two missiles and that the firings can only be carried out during specific availability windows.

[0006] Modeling such a scenario therefore poses a real problem that arms manufacturers encounter in developing solutions to this difficulty. The engagement plan must be feasible and optimal in terms of probability of success.

[0007] There is therefore a need to find a solution to determine an engagement plan that meets the above requirements. Display of the invention

[0008] The present invention relates to a method for determining an engagement plan for an air defense system, which makes it possible to meet the aforementioned need.

[0009] To this end, according to the invention, said method for determining an engagement plan for an air defense system comprising at least munitions (in particular missiles) capable of being fired from launchers, at least some of said launchers being capable of firing several munitions, the engagement plan consisting of allocating munitions of the air defense system to so-called target air threats, said method comprising the following steps, implemented automatically and successively: a data receiving step of receiving data relating to at least the available munitions and detected targets; and a processing step of, using the data received in the receiving step, forming the engagement plan, said engagement plan being used by the air defense system to defend a particular area against air threats, is remarkable in that: the data reception step also consists of receiving, for each munitions launcher of the air defense system, on the one hand the number of munitions of the launcher representing a first constraint concerning the munitions of said launcher, and on the other hand a number of firing dates in availability windows representing a second constraint concerning the firing dates; and the processing step consists of determining the engagement plan by taking into account said first and second constraints, said processing step comprising at least: a first sub-step consisting of determining, for each pair of target and munitions, a so-called classic benefit which represents a parameter making it possible to quantify the interest of using the munitions to neutralize the target, said classic benefit depending on a probability that the munitions destroy the target;a second sub-step consisting of determining, for each pair of target and ammunition, a so-called adapted profit, taking into account potential conflicts between allocators; and a third sub-step consisting of implementing an auction algorithm taking into account said first and second constraints and using said adapted profits for all the pairs of ammunition and target, in order to determine the engagement plan, said engagement plan comprising for each of said targets the allocation of on the one hand of at least one particular ammunition of a particular launcher and on the other hand of a firing date of this ammunition, this allocation satisfying said first and second constraints.;

[0010] Thus, thanks to the invention, an auction algorithm is used to determine the commitment plan. Such an auction algorithm has many advantages. In particular, it is very robust, its complexity allows saturating attacks to be understood in real time, and it converges towards a global maximum whereas the usual "greedy" type solutions only reach a local maximum, without any guarantee that this is close to the global maximum.

[0011] Furthermore, above all, thanks to the invention, the auction algorithm is made applicable to the determination of the commitment plan, in particular by determining the adapted profit. In the application considered, there are, in fact, two elements to be allocated (ammunition and firing date) which cannot be separated, and conflicts between allocations may appear, which could invalidate the commitment plan. The aforementioned method implementing the auction algorithm makes it possible to respond to such a situation: on the one hand, by satisfying said first and second constraints by implementing the auction algorithm; and on the other hand, by managing said potential allocation conflicts (or light conflicts) by calculating and taking into account the adapted profit instead of a classic profit (i.e. a usual profit of an auction algorithm).

[0012] Advantageously, the first sub-step determines the classic profit β ij using the following expression: β ij = u i p ij in which: p ij is the probability that an index ammunition j destroy a clue target i , the probability depending on the ammunition and the date of firing of the latter; and u i is a threat criterion assigned to the index target i .

[0013] The classic benefit β ijis therefore a parameter which makes it possible to quantify the interest in using a munition Mj to neutralize a target Ci. It weights the assignments in the objective function to be maximized (specified below).

[0014] The threat criterion u i quantifies the level of danger based on the target's classification. It is all the more important if the target represents an immediate danger or more generally a priority. It is set upstream of the auction algorithm based on the tactical situation and remains fixed throughout the calculation.

[0015] Furthermore, advantageously, the second sub-step determines the adjusted profit β' ij using the following expression: β ij ′ = β ij − 1 2 ∑ kl c ijkl x kl in which: β ij is the said classic benefit; c ijklis a coefficient greater than or equal to zero, which illustrates the importance of a conflict between two allocations [ij] (ammunition Mj allocated to target Ci) and [kl] (ammunition MI allocated to target Ck); and x h is a binary value that is 1 if the index ammunition l is allocated to the target with index k and which is 0 otherwise.

[0016] Furthermore, advantageously, the third sub-step implements the auction algorithm having the following characteristics: each index ammunition j being characterized by a price pj , each target bets on the ammunition that maximizes its profit argmax j β ′ ij − p j , with β' ij said adapted profit; the bet increases the price of the ammunition until all conflicts are resolved; this way of proceeding makes it possible to reach the overall maximum of the sum: ∑ ij β ij x ij , β ij ≥ 0 , x ij ≥ 0 with the following limitations on each target and each ammunition: ∑ j x ij = M i , ∑ i x ij ≤ N j according to which the auction algorithm allocates exactly Me ammunition to the index target i and does not allocate more than N j times the type of index ammunition j in a given launcher; and convergence is achieved when each target has allocated the desired number of munitions.

[0017] The said first and second constraints are taken into account in inequalities similar to the formulation: ∑ i x ij ≤ N j

[0018] So, for example in the case of a stockpile of ammunition, the number N j corresponds to the maximum number of ammunitions of the launcher in which the ammunition j is located. In the case of the number of firing dates, the number N j is the maximum number of shots that the launcher can make in the firing window where the firing date of the ammunition j is located in its launcher.

[0019] In a particular embodiment, the processing step also consists of determining, for the engagement plan, at least one of the following parameters for each of the munitions: if the munition is provided with a seeker for terminal guidance, a frequency for said seeker; and an uplink channel.

[0020] The present invention also relates to a method for dealing with air threats in the military field, using an air defense system comprising at least munitions capable of being fired from launchers.

[0021] According to the invention, said method comprises at least the following steps: a detection step consisting of detecting aerial objects (or flying objects) in a given area; an identification and classification step consisting of identifying, among the detected aerial objects, those which represent aerial threats called targets and determining a classification for each of the identified targets; a prediction step consisting of predicting a future trajectory for each of the identified targets, at least from the corresponding classification; a calculation step consisting of calculating an interception window, for each pair of munition and target, as a function of the predicted future trajectory of the target and an interception domain of the munition, each of said interception windows being transformed into an availability window;a processing step consisting of determining a commitment plan taking into account said availability windows, the processing step implementing a method for optimizing a commitment plan such as that mentioned above; and a step of executing the commitment plan.;

[0022] In a particular embodiment, each target corresponding to a particular type of target among types which may be different, the processing step takes into account, for each type of target, an engagement rule and / or a firing policy.

[0023] The present invention further relates to a device for determining an engagement plan for an air defense system comprising at least munitions capable of being fired from launchers, at least some of said launchers being capable of firing several munitions, the engagement plan consisting of allocating munitions from the air defense system to so-called target air threats.

[0024] According to the invention, said device for determining an engagement plan, which comprises at least the following units: a data receiving unit configured to receive data relating to at least available munitions and detected targets; and a processing unit configured to, using the data received from the data receiving unit, form the engagement plan, said engagement plan being used by the air defense system to defend a particular area against air threats, is remarkable in that: the data receiving unit is configured to also receive, for each munitions launcher of the air defense system, on the one hand the number of munitions of the launcher representing a first constraint concerning the munitions of said launcher, and on the other hand a number of firing dates in availability windows representing a second constraint concerning the firing dates; and the processing unit is configured to determine the engagement plan by taking into account said first and second constraints, the processing unit comprising at least: a first element configured to determine, for each pair of target and munitions, a so-called classic benefit which represents a parameter making it possible to quantify the interest of using the munitions to neutralize the target, said classic benefit depending on a probability that the munitions destroy the target;a second element configured to determine, for each pair of index target and ammunition, a so-called adapted profit, taking into account potential (so-called light) conflicts between allocations; and a third element configured to implement an auction algorithm taking into account said first and second constraints and using said adapted profits for all the pairs of ammunition and target, in order to determine the engagement plan, said engagement plan comprising for each target the allocation of at least one particular ammunition of a particular launcher and of a firing date of this ammunition, this allocation satisfying said first and second constraints. ;

[0025] Furthermore, the present invention also relates to a system for processing aerial threats in the military field, using an air defense system as mentioned above.

[0026] According to the invention, said aerial threat processing system comprises at least the following units: a detection unit configured to detect aerial objects in a given area; an identification and classification unit configured to identify, among the detected aerial objects, those which represent aerial threats called targets, and to determine a classification for each of the identified targets; a prediction unit configured to predict a future trajectory for each of the identified targets, at least from the corresponding classification; a calculation unit configured to calculate an interception window, for each pair of munition and target, as a function of the predicted future trajectory of the target and an interception domain of the munition, each of said interception windows being transformed into an availability window;and a processing unit configured to determine an engagement plan taking into account said availability windows, the processing unit comprising a device for determining an engagement plan such as that described above, said engagement plan being capable of being executed by said air defense system.; Brief description of the figures

[0027] Other characteristics and advantages of the device, system, process and / or method according to the invention will appear better on reading the following description of exemplary embodiments given for illustrative purposes and in no way limiting, appended to the following figures. There figure 1 is the block diagram of a threat processing system according to a particular embodiment of the invention, comprising a device for determining an engagement plan. The figure 2is a schematic view of an example of an air defense system that protects a land area against airborne threats. figure 3 schematically illustrates a threat processing method, implemented using the threat processing system of the figure 1 . There figure 4 is a graph illustrating, schematically and very partially, the relationships between missiles of the air defense system and targets corresponding to air threats. Detailed Description

[0028] The device 1 illustrating a particular embodiment of the invention and represented schematically on the figure 1 is intended to determine an engagement plan for an air defense system 2 shown on the figure 2 .

[0029] Air defense system 2 is intended to protect a given area, such as the ground zone Z0 shown in the figure 2, and this against aerial threats. The area to be protected can be a land area and / or a sea area.

[0030] To do this, the air defense system 2 comprises a plurality of launchers 4, each of which is capable of firing at least one munition and preferably a plurality of munitions.

[0031] In the context of the present invention, a munition corresponds to any object or neutralization device, for example a missile or a drone or more generally a set of effectors, capable of damaging or neutralizing (and destroying) an aerial threat. Preferably, the munitions correspond to missiles. Also, by way of non-limiting illustration, we will refer in the following description to Mi missiles as munitions. Of course, other munitions could be taken into account in a similar manner.

[0032] Concerning the Mi missiles used by the air defense system 2, these can be any usual type of missile, preferably but not exclusively surface-to-air. As for the launchers 4, these can be launchers installed in a fixed position or launchers mounted on mobile vehicles 4A, in particular vehicles capable of rolling on the ground.

[0033] Air threats (representing, in the context of this air, Ci targets for the air defence system 2) may correspond to all types of enemy weapons or aerial devices, and in particular to aircraft, missiles, drones, etc., likely to harm (damage, destroy, etc.) for example infrastructure or other elements located in the Z0 zone to be protected.

[0034] In the example of the figure 2, the air threats (or targets Ci) approach the zone Z0 to be protected by following trajectories Ti (called future, relative to the present moment), some of which have been represented as an example on this figure 2 .

[0035] In the particular example of the figure 2 : the zone Z0 to be protected is a polygonal zone on the ground; the launchers 4 are mobile vehicles 4A launching Mj missiles, each of which is capable of firing a plurality of Mj missiles, the Mj missiles being fired one after the other for a launcher 4; and the targets Ci (or aerial threats) correspond to fighter planes.

[0036] Device 1, which is intended to determine the engagement plan, is part of a system 3 for processing air threats in the military domain, represented on the figure 1The engagement plan consists of allocating Mj missiles of the air defense system 2 to air threats (Ci targets), as specified below, i.e. identifying particular Mj missiles which will be used or can be used by the air defense system 2 to neutralize particular Ci targets.

[0037] To do this, the device 1 comprises the following units, as shown in the figure 1 : a data receiving unit 5 configured to receive data relating to at least the available missiles Mj as well as detected targets Ci, as specified below; and a processing unit 6 configured to form the engagement plan, using the data received from the receiving unit 5. The engagement plan which can then be used by the air defense system 2 to defend the zone Z0 against air threats.

[0038] In addition, the data receiving unit 5 is configured to also receive, for each launcher 4 of Mj missiles of the air defense system 2: on the one hand, the number of missiles Mj of the launcher 4, this number representing a (first) constraint concerning the missiles Mj of said launcher 4; and on the other hand, a number of firing dates in availability windows, this number representing a (second) constraint concerning the firing dates.

[0039] Furthermore, the processing unit 6 is configured to determine the engagement plan by taking into account these first and second constraints for all the launchers 4 considered, and it comprises: an element 7 configured to determine, for each pair of target and missile, a so-called classic benefit; an element 8 configured to determine, for each pair of target and missile, a so-called adapted benefit from the classic benefit; and an element 9 configured to implement an auction algorithm using said adapted benefits for the different pairs of missile and target, so as to determine the engagement plan.

[0040] The engagement plan includes, for each target Ci, the allocation of a particular missile Mj from a particular launcher 4 and a firing date for the missile Mj, this allocation satisfying the aforementioned first and second constraints.

[0041] As for system 3, it includes, in addition to device 1, as shown in the figure 1 , the following units: a detection unit 10 configured to detect aerial objects in a given area of ​​space around the zone Z0 to be protected; and a data processing device 12, connected via a link 11 (for example a wired link or a radio link) to the detection unit 10, the data processing device 12 comprising the device 1.

[0042] The detection unit 10 comprises usual systems and means, and in particular one or more radars, such as a mobile radar 10A as shown in the figure 2 , capable of automatically detecting aerial objects entering a monitored area of ​​space which is located around the zone Z0 to be protected. The detection unit 10 automatically provides data (position, trajectory, etc.) relating to detected aerial objects to the data processing device 12.

[0043] The system 3 also comprises a data input unit 13 which is connected via a link 14 (for example a wired link or a radio link) to the data processing device 12 and which allows an operator to enter data into the system 3. The data input unit 13 may comprise a keyboard, a mouse, a touchpad, ..., or any other usual means, associated for example with a screen, which allows an operator to enter data as specified below.

[0044] Furthermore, the data processing device 12 comprises: an identification and classification unit 15 configured to identify, among the aerial objects detected by the detection unit 10 and received via the link 11 (wired or radio), those which represent aerial threats (called targets) and to define a classification for each of the identified targets; a prediction unit 16 configured to predict a future trajectory for each of the identified targets, at least from the corresponding classification; a calculation unit 17 configured to calculate an interception window, for each missile and target pair, as a function of the predicted future trajectory of the target and an interception domain of the missile. Each of the interception windows is transformed, in the usual manner, into an availability window; and a processing unit (in this case the device 1) which is configured to determine an engagement plan taking into account the availability windows.

[0045] The device 1 then transmits the engagement plan, via a link 18 (for example a wired link or a radio link) to user means 19, for example to display means (which display this optimal allocation plan on a screen available to an operator) or to a man / machine interface. In particular, the elements 13 and 19 may be part of the same man / machine interface.

[0046] The air threat processing system 3 aims to respond in real time and continuously to attack situations in a zone Z0 to be defended, by associating with each target identified as such, at least one missile Mj from a launcher 4. This system 3 can be located in a command and calculation center 20 ( figures 2 And 3 ).

[0047] System 3 uses Air Defense System 2 which includes: one or more radars 10A; several launchers 4 of Mj missiles; one or more uplinks (not shown) to guide the missiles; and the command and calculation center 20 which determines the engagement plan.

[0048] The connection between these different elements can be a wired connection or a radio connection.

[0049] System 3 faces multiple challenges that are likely to cause it to fail, including: saturating attacks, as shown in the figure 2 , for which the number of targets Ci is close to or equal to the number of munitions Mj; unpredictable targets, which maneuver at the last moment; and new aerial threats, such as drones evolving in swarms.

[0050] The system 3 is capable of implementing a method for dealing with air threats in the military domain, using an air defense system 2 comprising at least Mj missiles capable of being fired from launchers 4.

[0051] On the figure 3 , an example of the implementation of such a method has been shown. More precisely, in this example, the method presents the following steps, implemented successively: a detection step E1, implemented by the detection unit 10, consisting of detecting aerial objects in a given area; an identification and classification step E2, implemented by the identification and classification unit 15, consisting of identifying, among the detected aerial objects, those which represent aerial threats called targets, and of defining a classification for each of the identified targets; a prediction step E3, implemented by the prediction unit 16, consisting of determining a future trajectory for each of the identified targets, at least from the corresponding classification; a calculation step E4, implemented by the calculation unit 17, consisting of calculating an interception window for each missile and target pair, as a function of the predicted future trajectory of the target and an interception domain of the missile, each of said interception windows being transformed into an availability window;a processing step E5, implemented by the device 1, consisting of determining an engagement plan taking into account said availability windows, the processing step E5 using a method for determining an engagement plan as specified below; and a step of executing the engagement plan, implemented by at least some of the launchers 4 of the air defense system 2.;

[0052] The above steps of the aerial threat processing method are described in more detail below.

[0053] The detection step E1, implemented by the detection unit 10, therefore consists of detecting aerial objects in a given area of ​​space.

[0054] To do this, the detection unit 10 comprising, for example, the radars 10A, continuously receives information on the position of aerial (or flying) objects entering said zone or already there, i.e. a position in space on a given date.

[0055] Position information is merged together when it represents the same aerial object. It is then combined with previous position information to form distinct aerial objects or craft, essentially by correlation. The arrival frequency of position information is generally a few seconds at most, depending on the rotation speed of the 10A radar(s) used.

[0056] When a new aerial object is detected in the detection step E1 by the detection unit 10, the identification and classification unit 15 firstly carries out an identification in the usual manner in the identification and classification step E2 which follows. The purpose of the identification is to determine whether the aerial object detected by the detection unit 10 is a friendly object or an enemy object, i.e. a threat. This usual identification can, for example, be carried out by IFF (Identification Friend or Foe) type interrogation, the absence of a response from the aerial object however not necessarily meaning that it is an enemy.

[0057] If the identified aerial object is determined to be an enemy object, i.e. a target, the identification and classification unit 15 performs a classification at the identification and classification step E2. For this purpose, the identification and classification unit 15 determines the type (or class) of the target. Knowledge of the type (fighter, helicopter, missile, etc.) of the target makes it possible, in particular, to determine its trajectory and its danger. For example, a fighter, which can instantly release around ten bombs, is potentially more dangerous than a simple missile. In this case, the fighter will therefore be assigned a higher threat index (specified below) than a missile.

[0058] When one or more aerial objects are designated as targets Ci, the prediction unit 16 determines, in the prediction step E3 which follows, in the usual manner, the future trajectory of each of these targets. To do this, it can use the classification of the target, obtained in the identification and classification step E2. Indeed, an aerial object, for example a fighter or a missile, is constrained in its evolution by its flight dynamics, which makes it possible to predict its future trajectory.

[0059] The prediction unit 16 can also use to predict the future trajectory of a target Ci, if applicable, a point aimed at by the target Ci, in particular in the naval field.

[0060] Then, in the following calculation step E4, the calculation unit 17 calculates an interception window for each missile and target pair, using the predicted future trajectory of the target, determined in the prediction step E3, as well as an interception domain of the missile. The interception window concerns a sequence (continuous or discrete) of interception points (or dates).

[0061] As for the interception domain of a missile, it corresponds to a three-dimensional domain around the position of the missile in which the probability of it reaching the target is at least a predetermined percentage, preferably 90%. This interception domain is, for example, determined in calculation step E4, by a usual “Monte Carlo” type simulation.

[0062] Then, in the following processing step E5, the device 1 determines the commitment plan taking into account the availability windows determined in the calculation step E4. The processing step E5 implements a method for determining a commitment plan described in more detail below.

[0063] The engagement plan consists of optimally associating (or allocating) one or more missiles to each target, taking into account the interception windows, transformed into availability windows. The calculation time must not exceed a few hundred milliseconds, typically 200 ms.

[0064] An operator, in particular from the command and calculation chain 20, can intervene at the processing step E5 to configure, for each type of target, as illustrated by an arrow 21 on the figure 3 : a rule of engagement, that is to say in particular defining whether one wishes to fire as soon as possible, intercept as far away as possible or as late as possible, or let the target approach; and a fire policy, providing: an "SSL" type firing strategy (for "Shoot-Shoot Look" in English) consisting of firing two missiles and waiting for interception; or an "SLS" firing strategy (for "Shoot Look Shoot" in English) consisting of firing one missile, waiting for interception, then firing a new missile in the event of failure.

[0065] To do this, the operator can use the data input unit 13 to enter into the data processing device 12 the data allowing the configuration of the engagement rule and the firing policy.

[0066] Once the engagement plan has been calculated, i.e. a set of valid allocations has been obtained, the question of its execution arises when the firing date of an allocated missile expires. An operator, in particular from the command and calculation chain 20, can intervene at the execution step E6 to give a firing order, as illustrated by an arrow 22 on the figure 3 When the firing order is given, execution step E6 of the engagement plan is implemented by launchers 4 of air defense system 2.

[0067] Once the engagement plan has been executed (or not), the aforementioned method can be implemented again, starting with the detection of aerial objects. Missiles previously allocated, but not fired, can be reallocated, following the optimum that continuously adapts to the new situation.

[0068] A complete cycle of the method is implemented, in at most a few seconds.

[0069] As illustrated in the figure 1 , the method may also include an intermediate step E12 between steps E1 and E2. When a previously fired missile arrives at its interception point, step E12 ("Kill Assessment" in English) checks whether the target has been treated (neutralized) as planned, which makes it possible to know whether or not it is necessary to take this target into account as a new target in the rest of the method.

[0070] The method for determining an engagement plan, implemented by the device 1 in the processing step E5, is now described in more detail.

[0071] The engagement plan includes, for each target, a specific allocation. Each allocation (or association) of elements intended for the treatment (or neutralization of a target) is a group of elements representing adjustment parameters of the air defense system 2 for the treatment of air threats. Each allocation includes: the designation of the target (i.e. a detected air threat) in question; the designation of a particular missile which is fired by a particular launcher 4 and which is intended to deal with this target; and a particular firing date, namely the exact moment when said missile must be fired by said launcher to deal with (in particular neutralize) said target.

[0072] It is therefore necessary for the air defense system 2 to know, for each target, the missile which is intended to neutralize it and the date (or time) of firing of this missile. Indeed, in the context of the present invention, a launcher 4 comprises several missiles Mj and several availability windows within which a certain number of missile firings can be carried out, knowing that the launcher 4 can only fire a single missile at a time and that due to a preparation time for a new firing, two successive firings are spaced apart by a certain duration.

[0073] For each launcher 4 of Mj munitions of the air defense system 2, it is thus necessary to take into account the number (or stock) of Mj munitions of the launcher 4, which represents a (first) constraint concerning the Mj munitions of said launcher 4, and on the other hand a number of firing dates in availability windows, which represents a (second) constraint concerning the firing dates.

[0074] Moreover, it is not possible to separate the two constraints, because the probability p ij whether the missile Mj destroys the target Ci depends as much on the characteristics of the missile Mj (and the position of the launcher 4) as on the date on which it is fired.

[0075] Furthermore, when two missiles face each other when igniting their seekers, they risk targeting each other, and if their seekers are electromagnetic and of close frequencies, they will interfere. These conflicts that occur between allocations (missiles) are called soft conflicts, as opposed to hard (or resource) conflicts that occur between targets. Thanks to the invention, hard conflicts are resolved by using an auction algorithm and soft conflicts by determining an appropriate profit that is used by the auction algorithm, as specified below.

[0076] To illustrate an allocation, we have represented on the figure 4 , certain C1 to C4 targets of the air threat to which M1 to M6 missiles of the air defense system 2 can be allocated. Only the links concerning the C1 and C2 targets have been shown for reasons of clarity of the figure 4. Of course, the shooting dates should also be taken into account, as mentioned above.

[0077] As specified below, the method for determining an engagement plan, implemented by the device 1 in the processing step E5, will use an algorithm (or method or system) called an auction. Since the object of the auctions is not only the missile, but the missile and launch date pair, it is not possible to use a conventional auction algorithm as such because the latter only integrates a single type of constraint per object. This problem is solved by the method (for determining the engagement plan) in the manner described below.

[0078] Said method or processing step E5 ( figure 3 ) for the determination of an engagement plan, includes the following steps, implemented automatically and successively: a data reception step E5A, implemented by unit 5, consisting of receiving data relating to at least the available missiles and the detected targets. The data reception step E5A also consists of receiving, for each missile launcher of the air defense system, on the one hand the number of missiles of the launcher representing a first constraint concerning the missiles of said launcher, and on the other hand a number of firing dates in availability windows representing a second constraint concerning the firing dates; and a processing step E5B, implemented by unit 6, consisting, using the data received in the data reception step E5A, of forming the engagement plan.

[0079] The processing step E5B implemented by unit 6 consists of determining the engagement plan by taking into account said first and second constraints, and this processing step E5B comprises at least: a sub-step E5B1 implemented by element 7, consisting of determining, for each pair of targets Ci of index i and Mj missile index j , a so-called classic benefit β ij which represents a parameter allowing to quantify the interest of using the missile Mj to neutralize the target Ci. This classic benefit β ij depends on a probability that the ammunition Mj of index j destroys the target Ci of index i ; a sub-step E5B2 implemented by element 8, consisting of determining, for each pair of targets Ci of index i and Mj missile index j , a benefit β' ij said adapted which takes into account the potential slight conflicts between the allocations; and a sub-step E5B3 implemented by element 9, consisting of implementing an auction algorithm taking into account said first and second constraints and using said profits β' ijadapted for all missile and target pairs, in order to determine the engagement plan.

[0080] In the first sub-step E5B1, element 7 determines the classic profit β ij using the following expression: β ij = u i p ij in which: p ij is the probability that a missile Mj of index j destroys a target Ci of index i , the probability depending on the missile Mj and the firing date; and u i is a threat criterion assigned to the index target i .

[0081] This threat criterion is a factor that represents the dangerousness of the threat (or target). The dangerousness depends mainly on the type (or class) of the target. It is all the more important if the target represents an immediate danger or more generally a priority. It is set upstream of the bidding algorithm according to the tactical situation and remains fixed throughout the calculation.

[0082] The threat criterion u i quantifies the level of danger based on the target's classification. It is all the more important if the target represents an immediate danger or more generally a priority. It is set upstream of the auction algorithm based on the tactical situation and remains fixed throughout the calculation.

[0083] Further, in sub-step E5B2, element 8 determines the adjusted profit β' ij using the following expression: β ij ′ = β ij − 1 2 ∑ kl c ijkl x kl in which: β ij is the classic profit determined in sub-step E5B1; c ijkl is a coefficient greater than or equal to zero, which illustrates the importance of the conflict between two allocations [ij] (ammunition Mj allocated to target Ci) and [kl] (ammunition MI allocated to target Ck); and x h is a binary value that is 1 if the index ammunition l is allocated to the target with index k and which is 0 otherwise.

[0084] If allocation [kl] conflicts with allocation [ij] and if the MI ammunition is allocated to target Ck then x h is worth 1 and the profit β ij is reduced by the value c ijkl , which will push the algorithm to choose another ammunition Mj' for the target Ci. The coefficient c ijkl is determined from the safety rules between the different trajectories of munitions. For example, it can represent the distance that two munitions must respect between them for safety.

[0085] Furthermore, in substep E5B3, element 9 implements the auction algorithm. The auction algorithm has the following characteristics: each missile j being characterized by a price pj , each target bets on the missile that maximizes its profit argmax j β ′ ij − p j , with β' ijthe adjusted profit determined in sub-step E5B2; the bet increases the price of the ammunition until all conflicts are resolved; this way of proceeding makes it possible to reach the overall maximum of the sum: ∑ ij β ij x ij , β ij ≥ 0 , x ij ≥ 0 with the following two limitations on each target and each missile: ∑ j x ij = M i , ∑ i x ij ≤ N j Under these two limitations, the auction algorithm allocates exactly Me missiles to the index target i and does not allocate more than N j times the type of index missile j in a given launcher; convergence is achieved when each target has allocated the desired number of missiles.

[0086] In sub-step E5B3, said first and second constraints are taken into account in inequalities similar to the formulation: ∑ i x ij ≤ N j

[0087] So, for example in the case of a stockpile of ammunition, the number N jcorresponds to the maximum number of ammunitions of the launcher in which the ammunition j is located. In the case of the number of firing dates, the number N j is the maximum number of shots that the launcher can make in the firing window where the firing date of the ammunition j is located in its launcher.

[0088] In a particular embodiment, the processing step E5 also consists of determining, in the engagement plan, at least one of the following parameters for each of the missiles: a seeker frequency if the missile is equipped with a seeker (with electromagnetic guidance) for terminal guidance; and an uplink channel. A channel is an area in space surrounding a flight path that is intended to be followed by a missile. This channel, which presents a corridor for the missile to move, is said to be uplink, because the missile starts from the ground upwards towards the target to be neutralized.

[0089] In this particular embodiment, the engagement plan comprises, for each target, a particular allocation. Each allocation (or association) of elements is a group of elements representing adjustment parameters of the air defense system 2 for processing air threats. Each allocation comprises, in this case: the target; a particular missile capable of being fired from a particular launcher to treat (neutralize) the target; a particular firing date, that is to say the exact moment when said missile must be fired by said launcher to treat (in particular neutralize) said target; a particular seeker frequency if the missile is provided with a seeker for terminal guidance (electromagnetic guidance); and a particular uplink channel, for the movement of the missile towards the target.

[0090] During the first phase of flight after launch, the missile is guided to the target from the ground through the uplink channel. By assigning each missile a separate channel, interference between the missiles, which could invalidate the engagement plan, is prevented.

[0091] In the terminal phase of flight, the missile's seeker, which relies on electromagnetic or infrared detection of the target, is activated and is used to guide the missile until it intercepts the target. Therefore, care must be taken to ensure that the missiles use distinct electromagnetic frequencies, otherwise they could interfere and derail the engagement plan.

[0092] Device 1, as described above, thus has many advantages. The same is true of system 3 which uses this device 1.

[0093] Device 1 carries out processing quickly and appropriately to the complex situation considered.

[0094] To do this, device 1 uses an auction algorithm to determine the commitment plan and thus benefits from the advantages of such an auction algorithm. In particular, the auction algorithm is very robust, its complexity allows for real-time detection of saturating attacks, and it converges towards a global maximum whereas the usual "greedy" type solutions only reach a local maximum, without any guarantee that this is close to the global maximum.

[0095] Moreover, above all, the auction algorithm is made applicable to the determination of the commitment plan, in particular by determining the adapted profit, taking into account the two aforementioned constraints. In the applications considered, there are, in fact, two elements (ammunition and firing date) that cannot be dissociated, and conflicts between allocations may appear, which could invalidate the commitment plan. The aforementioned method implementing the auction algorithm makes it possible to respond to such a situation: on the one hand, by satisfying said first and second constraints by implementing the auction algorithm; and on the other hand, by managing said potential allocation conflicts (or light conflicts) by calculating and taking into account the adapted profit instead of a classic profit (i.e. a usual profit of an auction algorithm).

[0096] Device 1 and system 3 therefore make it possible to respond in real time and continuously to situations of attack on an area to be defended, by associating with each target identified as such, a missile in a launcher with a firing date. They make it possible to resolve a complex situation that is difficult to resolve by usual means, and in particular both heavy conflicts and light conflicts that may arise in the envisaged applications.

Claims

1. A method for determining an engagement plan for an air defense system (2) comprising at least munitions (Mi) capable of being fired from launchers (4), at least some of said launchers (4) being capable of firing several munitions (Mj), the engagement plan consisting in allocating munitions (Mj) from the air defense system (2) to aerial threats referred to as targets (Ci), each allocation being a group of elements representing parameters for adjusting the air defense system (2) in order to deal with the aerial threats, said method comprising the following steps, carried out automatically and successively, by a device (1) for determining an engagement plan: - a data reception step (E5A) implemented by a data reception unit (5) of the device (1) for determining an engagement plan and consisting in receiving data concerning at least the available munitions (Mj) and of the targets (Ci) detected; and - a processing step (E5B) implemented by a processing unit (6) of the device (1) for determining an engagement plan and consisting, with the aid of the data received in the reception step (E5A), in forming the engagement plan, said engagement plan being used by the air defense system (2) to defend a particular zone (Z0) against the aerial threats, - the data reception step (E5A) consisting in also receiving, for each launcher (4) of munitions (Mj) of the air defense system (2), on the one hand the number of munitions (Mj) of the launcher (4) representing a first constraint concerning the munition (Mj) of said launcher (4), and on the other hand a number of firing dates in the availability window representing a second constraint concerning the firing dates; and - the processing step (E5B) consisting in determining the engagement plan, taking into account said first and second constraints, characterized in that said processing step (E5B) includes at least: • a first sub-step (E5B1) consisting in determining, for each pair of target (Ci) and munition (Mj), a so-called conventional benefit which represents a parameter allowing quantification of the interest of using the munition (Mj) to neutralize the target (Ci), said conventional benefit depending on a probability that the munition (Mj) destroys the target (Ci); • a second sub-step (E5B2) consisting in determining, for each pair of target and munition, a so-called adapted benefit, taking into account potential conflicts between allocations; and • a third sub-step (E5B3) consisting in implementing an auction algorithm taking into account said first and second constraints and using said adapted benefits for all the pairs of munition and target, in order to determine the engagement plan, said engagement plan comprising, for each of said targets (Ci), the allocation, on the one hand, of at least one particular munition (Mj) from a particular launcher (4) and, on the other hand, of a firing date of this munition (Mj), this allocation satisfying said first and second constraints.

2. The method according to claim 1, characterized in that the first sub-step (E5B1) determines the conventional benefit βij using the following expression: β ij = u i p ij wherein: - pij is the probability of a munition (Mj) of index j destroying a target (Ci) of index i, the probability depending on the munition (Mj) and the firing date of this latter; and - ui is a threat criterion assigned to the target (Ci) of index i.

3. The method according to one of claims 1 and 2, characterized in that the second sub-step (E5B2) determines the adapted benefit β'ij using the following expression: β ij ′ = β ij − 1 2 ∑ kl c ijkl x kl wherein : - βij is said conventional benefit; - cijkl is a coefficient greater than or equal to zero, which illustrates the importance of a conflict between two allocations [ij] and [kl]; and - xkl is a binary value which is 1 if the munition of index l is allocated to the target of index k and is 0 otherwise.

4. The method according to any one of the preceding claims, characterized in that the third sub-step (E5B3) implements the auction algorithm having the following characteristics: - each munition (Mj) of index j being characterized by a price pj, each target (Ci) bets on the munition (Mj) which maximises its profit argmax j β ′ ij − p j with β'ij said adapted benefit; - the stake raises the price of munition (Mj) until all conflicts are resolved; - this method ensures that the overall maximum amount is reached: ∑ ij β ij x ij , β ij ≥ 0 , x ij ≥ 0 with the following limitations on each target (Ci) and each munition (Mj): ∑ j x ij = M i , ∑ i x ij ≤ N j according to which the auction algorithm allocates exactly Mi munitions to the target of index i and allocates no more than Nj times the type of munition of index j in a given launcher (4); and - the convergence is achieved when each target has allocated the desired number of munitions.

5. The method according to any one of the preceding claims, characterized in that the processing step (E5) consists in also determining, for the engagement plane, at least one of the following parameters for each munition (Mj): - if the munition (Mj) is provided with a homing head for terminal guidance, a frequency for said homing head; - an uplink channel.

6. The method for processing aerial threats in the military field, using an air defense system (2) comprising at least munitions (Mj) capable of being fired from launchers (4), characterized in that it comprises at least the following steps: - a detection step (E1) consisting in detecting aerial objects in a given zone; - an identification and classification step (E2) consisting in identifying, from among the aerial objects detected, those which represent aerial threats known as targets (Ci), and in determining a classification for each of the targets (Ci) thus identified; - a prediction step (E3) consisting in predicting a future trajectory for each of the targets (Ci) identified, at least on the basis of the corresponding classification; - a calculation step (E4) consisting in calculating an interception window, for each pair of munition and target, as a function of the predicted future trajectory of the target (Ci) and of an interception domain of the munition (Mj), each of said interception windows being transformed into an availability window; - a processing step (E5) consisting in determining an engagement plan taking into account said availability windows, the processing step (E5) implementing a method of determining an engagement plan according to any one of claims 1 to 5; and - an execution step (E6) for executing the engagement plan.

7. The method according to claim 6, characterized in that, each target (Ci) corresponding to a particular type of target from among different types, the processing step (E5) takes into account, for each type of target, a rule of engagement and / or a firing policy.

8. A device for determining an engagement plan for an air defense system (2) comprising at least munitions (Mj) capable of being fired from launchers (4), at least some of said launchers (4) being capable of firing several munitions (Mj), the engagement plan consisting in allocating munitions (Mj) from the air defense system (2) to aerial threats referred to as targets (Ci), each allocation being a group of elements representing parameters for adjusting the air defense system (2) in order to deal with the aerial threats, said device (1) comprising at least the following units : - a data reception unit (5) configured to receive data concerning at least the available munitions (Mj) and detected targets (Ci); and - a processing unit (6) configured to, using the data received from the data reception unit (5), form the engagement plan, the engagement plan consisting in allocating to each target (Ci) detected one or more munitions (Mj), said engagement plan being used by the air defense system (2) to defend a particular zone (Z0) against aerial threats, - the data reception unit (5) being configured to also receive, for each launcher (4) of munitions (Mj) of the air defense system (2), on the one hand the number of munitions (Mj) of the launcher (4) representing a first constraint concerning the munitions (Mj) of said launcher (4), and on the other hand a number of firing dates in availability windows representing a second constraint concerning the firing dates; and - the processing unit (6) being configured to determine the engagement plan by taking into account said first and second constraints, characterized in that the processing unit (6) comprises at least: • a first element (7) configured to determine, for each pair of target (Ci) and munition (Mj), a so-called conventional benefit which represents a parameter allowing quantification of the interest of using the munition (Mj) to neutralize the target (Ci), said conventional benefit depending on a probability that the munition (Mj) destroys the target (Ci); • a second element (8) configured to determine, for each pair of target and munition, a so-called adapted benefit, taking into account potential conflicts between allocations; and • a third element (9) configured to implement an auction algorithm taking into account said first and second constraints and using said benefits adapted for all pairs of munition and target, in order to determine the engagement plan, said engagement plan comprising for each target (Ci) the allocation of on the one hand at least one particular munition (Mj) from a particular launcher (4) and on the other hand a firing date for this munition (Mj), this allocation satisfying said first and second constraints.

9. System for dealing with aerial threats in the military field, using an air defense system (2) comprising at least munitions (Mj) capable of being fired from launchers (4), characterized in that it comprises at least the following units: - a detection unit (10) configured to detect aerial objects in a given zone; - an identification and classification unit (15) configured to identify, from among the aerial objects detected, those which represent aerial threats known as targets (Ci), and to define a classification for each of the targets (Ci) identified; - a prediction unit (16) configured to predict a future trajectory for each of the identified targets (Ci), at least on the basis of the corresponding classification; - a calculation unit (17) configured to calculate an interception window, for each pair of munition and target, as a function of the predicted future trajectory of the target (Ci) and of an interception domain of the munition (Mj), each of said interception windows being transformed into an availability window; and - a processing unit (1) configured to determine an engagement plan by taking into account said availability windows, the processing unit comprising a device (1) for determining an engagement plan according to claim 8, said engagement plan being capable of being executed by said air defense system (2).

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