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

Abstract

The device determines, by means of a processing unit, an engagement plan for an air defence system (2) comprising munitions (Mj) fired from launchers (4), the processing unit determining the engagement plan by implementing an auction algorithm that takes into account, on the one hand, the number of munitions (Mj) of the launcher (4), which is a first constraint relating to the munitions (Mj) of the launcher (4), and, on the other hand, a number of firing dates in availability windows, which is a second constraint relating to the firing dates, the engagement plan comprising, for each target (Ci), allocation, on the one hand, of a particular munition (Mj) of a particular launcher (4) and, on the other hand, of a firing date of this munition (Mj), this allocation meeting said first and second constraints.

Description

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

[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. 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.

[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 reception step consisting of receiving data concerning at least the available munitions and detected targets;and- a processing step consisting, using the data received in the receiving step, in 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 receiving step consists of also 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 ammunition, a so-called classic benefit which represents a parameter making it possible to quantify the interest of using the ammunition to neutralize the target, said classic benefit depending on a probability that the ammunition destroys the target;• a second sub-step consisting of determining, for each pair of target and ammunition, a so-called adapted benefit, by 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 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 arise, 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 slight 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 using the following expression: in which:- is the probability that a munition of index j destroys a target of index i, the probability depending on the munition and the date of firing of the latter; and- is a threat criterion assigned to the index target.

[0013] The classic benefit is 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 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 using the following expression: in which:- is the said classic benefit;- is 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 Ml allocated to target Ck); and- is a binary value that is 1 if the ammunition with index is allocated to the target with index and is 0 otherwise.

[0016] Furthermore, advantageously, the third sub-step implements the auction algorithm having the following characteristics: - each ammunition of index being characterized by a price , each target bets on the ammunition that maximizes its profit , with 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: with the following limitations on each target and each ammunition: according to which the auction algorithm allocates exactly ammunition to the index target and does not allocate more than times the type of index ammunition 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:

[0018] So, for example in the case of a stockpile of ammunition, the number 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 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 homing device for terminal guidance, a frequency for said homing device; 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 the 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 ammunition, a so-called classic benefit which represents a parameter making it possible to quantify the interest of using the ammunition to neutralize the target, said classic benefit depending on a probability that the ammunition destroys the target;• a second element configured to determine, for each pair of index target and ammunition, a so-called adapted benefit, by 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 on the one hand at least one particular ammunition of a particular launcher and on the other hand a date of firing 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.

[0028] This is the block diagram of a threat processing system in accordance with a particular embodiment of the invention, comprising a device for determining an engagement plan.

[0029] This is a schematic view of an example of an air defense system that protects a land area against airborne threats.

[0030] Schematically illustrates a threat processing method, implemented using the threat processing system of the.

[0031] This 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

[0032] The device 1 illustrating a particular embodiment of the invention and represented schematically on the is intended to determine an engagement plan for an air defense system 2 represented on the.

[0033] The air defense system 2 is intended to protect a given area, such as the ground zone Z0 shown in the figure, against air threats. The area to be protected can be a land area and / or a sea area.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] In the example of the, 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.

[0039] In the particular example of:- the zone Z0 to be protected is a polygonal zone on the ground;- the launchers 4 are mobile vehicles 4A launching missiles Mj, each of which is capable of firing a plurality of missiles Mj, the missiles Mj being fired one after the other for a launcher 4; and- the targets Ci (or aerial threats) correspond to fighter aircraft.

[0040] The 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. The engagement plan consists of allocating missiles Mj of the air defense system 2 to air threats (targets Ci), as specified below, that is to say to identify particular missiles Mj which will be used or can be used by the air defense system 2 to neutralize particular targets Ci.

[0041] To do this, the device 1 comprises the following units, as shown in the: - a data reception 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 reception unit 5. The engagement plan which can then be used by the air defense system 2 to defend the zone Z0 against air threats.

[0042] 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 Mj missiles of the launcher 4, this number representing a (first) constraint concerning the Mj missiles 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.

[0043] 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.

[0044] 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.

[0045] As for the system 3, it comprises, in addition to the device 1, as shown in the, 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.

[0046] 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, capable of automatically detecting aerial objects entering a monitored area of ​​the 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.

[0047] 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, etc., or any other usual means, associated for example with a screen, which allows an operator to enter data as specified below.

[0048] 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 way, into an availability window; and - a processing unit (in this case device 1) which is configured to determine an engagement plan taking into account the availability windows.

[0049] The device 1 then transmits the commitment 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.

[0050] 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).

[0051] System 3 uses the 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.

[0052] The connection between these different elements can be a wired connection or a radio connection.

[0053] System 3 faces multiple challenges that are likely to put it at fault, including:- saturating attacks, as shown in, 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.

[0054] 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.

[0055] On the, an example of implementation of such a method is 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 pair of missile and target, 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.;

[0056] The above steps of the aerial threat processing method are described in more detail below.

[0057] The detection step E1, implemented by the detection unit 10, therefore consists of detecting aerial objects in a given area of ​​space.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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).

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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:- an engagement rule, that is to say in particular to define whether one wishes to fire as soon as possible, intercept as far away as possible or as late as possible, or to let the target approach; and- a firing policy ("Fire Policy" in English), 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 a missile, waiting for interception, then firing a new missile in the event of failure.

[0069] 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.

[0070] 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. When the firing order is given, the execution step E6 of the engagement plan is implemented by the launchers 4 of the air defense system 2.

[0071] 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.

[0072] A complete cycle of the method is implemented, in at most a few seconds.

[0073] As illustrated in the, 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") 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.

[0074] The method for determining an engagement plan, implemented by the device 1 in the processing step E5, is now described in more detail.

[0075] 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) considered;- the designation of a specific missile which is fired by a specific launcher 4 and which is intended to treat this target; and- a specific firing date, namely the exact moment when said missile must be fired by said launcher to treat (in particular neutralize) said target.

[0076] 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.

[0077] 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.

[0078] Moreover, it is not possible to separate the two constraints, because the probability 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.

[0079] 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 adapted profit that is used by the auction algorithm, as specified below.

[0080] To illustrate an allocation, some C1 to C4 targets of the air threat have been shown on the figure, 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 course, the firing dates should also be taken into account, as indicated previously.

[0081] 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.

[0082] Said method or processing step E5 () for determining an engagement plan, comprises the following steps, implemented automatically and successively: - a data reception step E5A, implemented by the 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 the unit 6, consisting, using the data received in the data reception step E5A, of forming the engagement plan.

[0083] The processing step E5B implemented by the 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 the element 7, consisting of determining, for each pair of target Ci of index i and missile Mj of index j, a so-called classic benefit which represents a parameter allowing to quantify the interest of using the missile Mj to neutralize the target Ci. This classic benefit depends on a probability that the ammunition Mj of index destroys the target Ci of index ;- a sub-step E5B2 implemented by element 8, consisting of determining, for each pair of target Ci of index i and missile Mj of index j, a benefit 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 adapted for all missile and target pairs, in order to determine the engagement plan.

[0084] In the first sub-step E5B1, element 7 determines the classic profit using the following expression: in which:- 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 date of launch; and- is a threat criterion assigned to the target with index i.

[0085] 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.

[0086] The threat criterion 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.

[0087] Further, in sub-step E5B2, element 8 determines the adjusted profit using the following expression: in which:- is the classic profit determined in sub-step E5B1;- 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 Ml allocated to target Ck); and- is a binary value that is 1 if the ammunition with index is allocated to the target with index and is 0 otherwise.

[0088] If allocation [kl] conflicts with allocation [ij] and if ammunition Ml is allocated to target Ck then is worth 1 and the profit is reduced by the value , which will push the algorithm to choose another ammunition Mj' for the target Ci. The coefficient 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.

[0089] Furthermore, in sub-step E5B3, element 9 implements the auction algorithm. The auction algorithm has the following characteristics: - each missile j being characterized by a price , each target bets on the missile that maximizes its profit , with the 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: with the following two limitations on each target and each missile: Under these two limitations, the auction algorithm allocates exactly missiles to the index target and does not allocate more than times the type of index missile in a given launcher; - convergence is obtained when each target has allocated the desired number of missiles.

[0090] In sub-step E5B3, said first and second constraints are taken into account in inequalities similar to the formulation:

[0091] So, for example in the case of a stockpile of ammunition, the number 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 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.

[0092] 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 provided 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 trajectory corridor for the missile, is said to be uplink, because the missile starts from the ground upwards in the direction of the target to be neutralized.

[0093] 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 process (neutralize) the target;- a particular firing date, i.e. the exact moment when said missile must be fired by said launcher to process (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.

[0094] 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.

[0095] 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.

[0096] Device 1, as described above, thus has many advantages. The same is true of system 3 which uses this device 1.

[0097] Device 1 carries out processing quickly and appropriately to the complex situation considered.

[0098] 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.

[0099] Furthermore, 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 slight conflicts) by calculating and taking into account the adapted profit instead of a classic profit (i.e. a usual profit of an auction algorithm).

[0100] 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

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 of allocating munitions (Mj) of the air defense system (2) to aerial threats called targets (Ci), each allocation being a group of elements representing adjustment parameters of the air defense system (2) for processing aerial threats, said method comprising the following steps, implemented 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 of receiving data concerning at least the munitions (Mj) available and detected targets (Ci);and- a processing step (E5B) implemented by a processing unit (6) of the device (1) for determining an engagement plan and consisting, using 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 aerial threats,characterized in that:- the data reception step (E5A) consists of 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 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 step (E5B) consists of determining the engagement plan by taking into account said first and second constraints, said processing step (E5B) comprising at least:• a first sub-step (E5B1) consisting of determining, for each pair of target (Ci) and munition (Mj), a so-called classic benefit which represents a parameter making it possible to quantify the interest of using the munition (Mj) to neutralize the target (Ci), said classic benefit depending on a probability that the munition (Mj) destroys the target (Ci);• a second sub-step (E5B2) consisting of determining, for each pair of target and munition, a so-called adapted benefit, by taking into account potential conflicts between allocations;and• a third sub-step (E5B3) consisting of implementing an auction algorithm taking into account said first and second constraints and using said adapted profits for all the ammunition and target pairs, 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 ammunition (Mj) of a particular launcher (4) and on the other hand of a firing date of this ammunition (Mj), this allocation satisfying said first and second constraints.; Method according to claim 1, characterized in that the first sub-step (E5B1) determines the conventional profit using the following expression: in which:- is the probability that a munition (Mj) of index j destroys a target (Ci) of index i, the probability depending on the munition (Mj) and the date of firing of the latter; and- is a threat criterion assigned to the target (Ci) of indexi. Method according to one of claims 1 and 2, characterized in that the second sub-step (E5B2) determines the adapted profit using the following expression: in which:- is the said classic benefit;- is a coefficient greater than or equal to zero, which illustrates the importance of a conflict between two allocations [ij] and [kl]; and- is a binary value that is 1 if the ammunition with index is allocated to the target with index and is 0 otherwise. 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 being characterized by a price , each target (Ci) bets on the ammunition (Mj) which maximizes its profit , with said adapted profit;- the bet increases the price of the ammunition (Mj) until all conflicts are resolved;- this way of proceeding makes it possible to reach the overall maximum of the sum: with the following limitations on each target (Ci) and each munition (Mj): according to which the auction algorithm allocates exactly ammunition to the index target and does not allocate more than times the type of index ammunition in a given launcher (4); and- convergence is obtained when each target has allocated the desired number of munitions. Method according to any one of the preceding claims, characterized in that the processing step (E5) consists of also determining, for the engagement plan, at least one of the following parameters for each of the munitions (Mj): - if the munition (Mj) is provided with a homing device for terminal guidance, a frequency for said homing device; - an uplink channel. 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 of detecting aerial objects in a given area; - an identification and classification step (E2) consisting of identifying, among the detected aerial objects, those which represent aerial threats called targets (Ci), and determining a classification for each of the targets (Ci) thus identified; - a prediction step (E3) consisting of predicting a future trajectory for each of the targets (Ci) identified, at least from the corresponding classification;- a calculation step (E4) consisting of calculating an interception window, for each pair of ammunition and target, as a function of the predicted future trajectory of the target (Ci) and of an interception domain of the ammunition (Mj), each of said interception windows being transformed into an availability window; - a processing step (E5) consisting of determining an engagement plan taking into account said availability windows, the processing step (E5) implementing a method for determining an engagement plan according to any one of claims 1 to 5; and - a step (E6) of executing the engagement plan.; Method according to claim 6, characterized in that, each target (Ci) corresponding to a particular type of target among different types, the processing step (E5) takes into account, for each type of target, an engagement rule and / or a firing policy. 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 of allocating munitions (Mj) of the air defense system (2) to aerial threats called targets (Ci), each allocation being a group of elements representing adjustment parameters of the air defense system (2) for processing aerial threats, said device (1) comprising at least the following units: - a data reception unit (5) configured to receive data relating to at least the munitions (Mj) available and detected targets (Ci);and- a processing unit (6) configured to, using the data received from the data receiving unit (5), form the engagement plan, the engagement plan consisting of allocating to each detected target (Ci) one or more munitions (Mj), said engagement plan being used by the air defense system (2) to defend a particular area (Z0) against aerial threats,characterized in that:- the data receiving unit (5) is 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) is configured to determine the engagement plan by taking into account said first and second constraints, the processing unit (6) comprising at least:• a first element (7) configured to determine, for each pair of target (Ci) and ammunition (Mj), a so-called classic benefit which represents a parameter making it possible to quantify the interest of using the ammunition (Mj) to neutralize the target (Ci), said classic benefit depending on a probability that the ammunition (Mj) destroys the target (Ci);• a second element (8) configured to determine, for each pair of index target and ammunition, a so-called adapted benefit, by 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 adapted profits for all the ammunition and target pairs, in order to determine the engagement plan, said engagement plan comprising for each target (Ci) the allocation on the one hand of at least one particular ammunition (Mj) of a particular launcher (4) and on the other hand of a firing date of this ammunition (Mj), this allocation satisfying said first and second constraints.; System 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 units: - a detection unit (10) configured to detect aerial objects in a given area; - an identification and classification unit (15) configured to identify, among the detected aerial objects, those which represent aerial threats called targets (Ci), and to define a classification for each of the identified targets (Ci); - a prediction unit (16) configured to predict a future trajectory for each of the identified targets (Ci), at least from the corresponding classification;- a calculation unit (17) configured to calculate an interception window, for each pair of ammunition and target, as a function of the predicted future trajectory of the target (Ci) and of an interception domain of the ammunition (Mj), each of said interception windows being transformed into an availability window; and - a processing unit (1) configured to determine an engagement plan 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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