EP3415860B1 - Method for predicting the trajectory of a hostile aircraft, particularly in the context of anti-air defence - Google Patents

Method for predicting the trajectory of a hostile aircraft, particularly in the context of anti-air defence Download PDF

Info

Publication number
EP3415860B1
EP3415860B1 EP18175386.4A EP18175386A EP3415860B1 EP 3415860 B1 EP3415860 B1 EP 3415860B1 EP 18175386 A EP18175386 A EP 18175386A EP 3415860 B1 EP3415860 B1 EP 3415860B1
Authority
EP
European Patent Office
Prior art keywords
aircraft
point
hostile
trajectory
impact
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
EP18175386.4A
Other languages
German (de)
French (fr)
Other versions
EP3415860A1 (en
Inventor
Pierre STOLZ
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Thales SA
Original Assignee
Thales SA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Family has litigation
First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=62567271&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=EP3415860(B1) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Application filed by Thales SA filed Critical Thales SA
Publication of EP3415860A1 publication Critical patent/EP3415860A1/en
Application granted granted Critical
Publication of EP3415860B1 publication Critical patent/EP3415860B1/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F41WEAPONS
    • F41GWEAPON SIGHTS; AIMING
    • F41G7/00Direction control systems for self-propelled missiles
    • F41G7/20Direction control systems for self-propelled missiles based on continuous observation of target position
    • F41G7/22Homing guidance systems
    • F41G7/2206Homing guidance systems using a remote control station
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F41WEAPONS
    • F41GWEAPON SIGHTS; AIMING
    • F41G7/00Direction control systems for self-propelled missiles
    • F41G7/20Direction control systems for self-propelled missiles based on continuous observation of target position
    • F41G7/22Homing guidance systems
    • F41G7/224Deceiving or protecting means
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F41WEAPONS
    • F41HARMOUR; ARMOURED TURRETS; ARMOURED OR ARMED VEHICLES; MEANS OF ATTACK OR DEFENCE, e.g. CAMOUFLAGE, IN GENERAL
    • F41H11/00Defence installations; Defence devices
    • F41H11/02Anti-aircraft or anti-guided missile or anti-torpedo defence installations or systems

Definitions

  • the present invention relates to a method for predicting the trajectory of a hostile aircraft. It relates in particular to naval anti-aircraft defense by predicting the target targeted by a hostile aircraft attacking one of several possible ships, the aircraft possibly being for example a missile. More generally, the invention applies to all anti-aircraft defenses where it is necessary to foresee the attacked target among several.
  • a set of ships liable to be attacked by hostile aircraft consists, for example, of a frigate, a large armed naval vessel and several large naval vessels that are not necessarily armed.
  • the frigate is for example followed at a distance of approximately 15 km for the armed naval vessel, the two unarmed vessels following the frigate more closely.
  • the important armed building has powerful means of defense to protect itself, it is for example an aircraft carrier, but it nevertheless needs to be defended by a first defense barrier consisting of the frigate. The latter must, for example, eliminate 80% of the dangers.
  • US 2016/0131455 A1 discloses a method for determining the course of a hostile aircraft towards a given target.
  • the object of the invention is in particular to reduce this degree of uncertainty.
  • the subject of the invention is a method for predicting, at a given instant, the trajectory of a hostile aircraft vis-à-vis buildings, said hostile aircraft (H) has a heading angle ⁇ at moment considered and is located at a distance D from a predicted target point which corresponds to the building having the highest probability of being targeted by the aircraft according to the flight parameters of the latter at the moment considered, or which is the barycenter of the positions of the buildings likely to be targeted by the hostile aircraft, weighted by their probability of being targeted by the latter, characterized in that the predicted trajectory is defined from an extrapolation of a given type of trajectory and connects the position of the hostile aircraft to a fictitious point of impact, the fictitious point of impact being defined, according to the predicted objective point aimed by the aircraft, so as to reduce the curvature of the predicted trajectory taking into account the heading angle ⁇ of the aircraft and the distance this D between the aircraft and the predicted target point at the instant considered, the predicted trajectory then being supplied to calculation means of an air defense missile so as to determine its
  • the main advantages of the invention are that it can be applied to counter many types of hostile aircraft, that it adapts to different types of trajectories of these aircraft and that it can adapt to already existing systems. .
  • the figure 1 presents an example of a set of buildings represented by their location points F, C1, C2, HV.
  • a frigate F is ahead of a building with a high HV value capable of defending itself, an aircraft carrier for example.
  • a distance of about 15 km separates, for example, the frigate from the high-value building.
  • the consort buildings C1, C2 are for example located in a circular zone of 6.5 km radius centered on the frigate F. In the event of an alert, the frigate can only fulfill its mission if it knows what a hostile aircraft is aiming for. , hence the need to predict the intended target.
  • the figure 1 presents at a given instant, through a point H, the position of a hostile aircraft.
  • two trajectories T1, T2 are for example still possible.
  • the correct trajectory Once the correct trajectory has been defined, it can be transmitted, for example, to an anti-aircraft missile launching system. Knowing this trajectory, calculation means define the trajectory of a missile in such a way that the latter meets the predicted trajectory of the hostile aircraft, the point of impact between the two machines taking place at the intersection of the two trajectories .
  • Hostile aircraft are for example missiles with great maneuverability, especially for short turns.
  • the figure 2 illustrates the main steps for implementing the method according to the invention.
  • a first step 1 predicts an objective point targeted by a spotted, in particular hostile, aircraft.
  • a second step 2 determines a fictitious point of impact as a function of the predicted target target point.
  • a third step 3 determines a trajectory of the aircraft ending on the previously determined fictitious point of impact.
  • This trajectory is then taken into account by anti-aircraft means, a missile for example, to define a meeting point between the latter and the hostile aircraft to which this trajectory is attributed, the destruction of the hostile aircraft being done by example at this meeting point.
  • anti-aircraft means a missile for example
  • a fictitious point of impact to define the trajectory of the spotted aircraft and not using the predicted objective point, in fact improves the chances of hitting a hostile aircraft. Indeed, once the objective point of the predicted aircraft, several trajectories are possible between this aircraft and the predicted objective point. All these trajectories cannot for example be memorized by the calculation means associated with an anti-aircraft missile, these calculation means defining in particular from a predicted trajectory of the aircraft the meeting point of the latter with the missile.
  • a single trajectory can for example be memorized by the calculation means while by acting on one of the ends of this trajectory, the meeting point calculated on this trajectory can effectively correspond to the actual meeting of the missile or of any other air defenses and hostile aircraft.
  • One objective of the method according to the invention is therefore to provide the anti-aircraft missile, based on radar information and the position of the ships, with the predicted position of the impact between a hostile aircraft and the missile so as to promote the interception hostile aircraft.
  • the picture 3 illustrates an example of a possible implementation of the method according to the invention by two sub-steps 11, 12, a first sub-step 11 of classifying potentially attackable ships followed by a second sub-step of determining the targeted objective .
  • the figure 4 presents in the plane ( x , y ) the position O of an analyzed building and the position D of a hostile aircraft, all the buildings being analyzed successively.
  • Curve 41 represents a cubic trajectory, corresponding to relation (1), for which the definition of the boundary conditions makes it possible to define the coefficients of relation (1).
  • a principle adopted consists for example in associating with a ship a probability Pcap which is all the greater as the heading of the runway of the aircraft compared to the building analyzed is low.
  • the probability Pcap is equal to 0. If ⁇ is between ⁇ min and ⁇ max, the probability decreases linearly from 1 to 0 as illustrated by the figure 5 , it is 1 when ⁇ is less than ⁇ min.
  • Relation (4) thus ensures a fairly severe discrimination in distance between 5 km and 15 km.
  • the objective is to determine which ships the maneuver of the hostile aircraft is taking place towards. This detection is based for example on the exploitation of the results of a linear regression on the last estimated positions.
  • the purpose of the linear regression on the last estimated positions makes it possible to shelter as much as possible from an error in estimating the direction taken by the hostile aircraft. Only for example the window containing the last four positions estimated by the multifunction radar is considered.
  • the figure 6 illustrates the maneuver detection criterion.
  • a hostile aircraft H successively presents three speed vectors V 1 , V 2 , V 3 .
  • the maneuver probability depends for example on the relative position of the last three speed vectors V 1 , V 2 , V 3 with respect to the aforementioned straight line 61, this probability increasing when these vectors successively approach the straight line, that is to say that the angle they make with the straight line decreases.
  • the probability Pm freezes at 1, i.e. it no longer intervenes in the combination with the other criteria.
  • the probability Pm is fixed at 1 for example after a given number of speed vectors V 4 successive aircraft located on the same side of the right; this number can be equal for example to 3.
  • the classification of ships is done by combining for each of them the results of the three previously defined probabilities Pcap , Pdis and Pm.
  • the first possibility consists simply in retaining the ship with the highest probability of being targeted Pv .
  • the second possibility consists in carrying out the calculation of a barycenter from the position of each ship weighted by its probability of being targeted Pv , the calculated barycenter then being considered as the point targeted by the aircraft.
  • This second solution makes it possible in particular to eliminate discontinuities.
  • the second step 2 determines a fictitious point of impact as a function of this predicted target, this target possibly being for example the ship with the highest probability of be targeted or the barycenter as previously calculated.
  • the curvature of the cubic trajectory is therefore important.
  • the calculated cubic trajectory 73 moves away significantly from the true trajectory of the aircraft.
  • the second step 2 makes it possible to approximate the predicted cubic trajectory 73 of the actual trajectory, in particular by reducing its curvature.
  • the second step 2 consists in particular, from the targeted objective determined during step 1, in calculating a fictitious point of impact which reduces the curvature, by reducing the distance D and the heading angle ⁇ when these latter are too important. Reducing the curvature of the cubic trajectory thus brings it closer to the real trajectory.
  • the fictitious point of impact is for example located on the line segment between the predicted target target and the orthogonal projection of this predicted target on the line carried by the speed vector of the hostile aircraft as illustrated by the figure 8 .
  • the predicted targeted objective is for example either the ship having the highest probability of being targeted, or the barycenter of the vessels weighted by their probabilities of being targeted.
  • the second step determines for example a fictitious point of impact I located on the line segment 81 between the position 0 of the predicted objective, located for example at the center of the system of axes x , y , and the orthogonal projection N of this objective on the straight line 82 passing through the position P of the aircraft and carried by its speed vector V .
  • This fictitious point of impact is used as a new boundary condition to define the predicted cubic trajectory, starting from the fact that this trajectory ends at this fictitious point of impact.
  • the shape of the curvature is given by relation (5) and the decrease in D and ⁇ decreases the curvature.
  • the figure 9 shows that the new distance D ' between the aircraft and the fictitious point of impact is less than the distance D between the predicted target and the aircraft. The same is true for the heading angles ⁇ ', ⁇ .
  • the coefficient ⁇ is a function of the distance D and the heading angle ⁇ .
  • This coefficient ⁇ can for example be defined by neglecting the influence of the distance D . This may in particular be permitted by the fact that the targets concerned are for example located between 5 km and 15 km, in this distance range only the influence of the heading angle ⁇ being preponderant.
  • the figure 10 illustrates by a diagram an example of possible determination of the coefficient ⁇ represented on the ordinate as a function of the heading angle ⁇ represented on the abscissa.
  • the coefficient ⁇ is limited for example to 0.5, in particular so as not to reduce the length of the cubic trajectory too much.
  • the time taken by the hostile aircraft to travel the cubic trajectory to the fictitious point of impact must be large enough to allow an anti-aircraft missile to calculate the interception time.
  • the fictitious point of impact I is located on the first half of the segment [ ON ] starting from position O of the predicted target objective.
  • a new cubic trajectory 101 is calculated in the third step 3 of the method according to the invention taking into account a fictitious point of impact as defined above.
  • the radius of curvature of the new cubic trajectory 101 having clearly decreased compared to the first cubic trajectory 73, this new cubic trajectory is considerably closer to the real trajectory.
  • the trajectory 101 thus defined is then supplied, for example, to an anti-aircraft missile whose calculation means will determine its point of interception with the aircraft on this same trajectory.

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Aviation & Aerospace Engineering (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Radar Systems Or Details Thereof (AREA)
  • Regulating Braking Force (AREA)

Description

La présente invention concerne un procédé de prédiction de la trajectoire d'un aéronef hostile. Elle concerne notamment la défense antiaérienne navale par la prédiction de l'objectif visé par un aéronef hostile attaquant un navire parmi plusieurs possibles, l'aéronef pouvant être par exemple un missile. Plus généralement l'invention s'applique à toutes défenses antiaériennes où il est nécessaire de prévoir la cible attaquée parmi plusieurs.The present invention relates to a method for predicting the trajectory of a hostile aircraft. It relates in particular to naval anti-aircraft defense by predicting the target targeted by a hostile aircraft attacking one of several possible ships, the aircraft possibly being for example a missile. More generally, the invention applies to all anti-aircraft defenses where it is necessary to foresee the attacked target among several.

Un ensemble de navires susceptible d'être attaqué par des aéronefs hostiles est constitué par exemple d'une frégate, d'un bâtiment naval important armé et de plusieurs bâtiments navals importants non nécessairement armés. La frégate est par exemple suivie à une distance d'environ 15 km pour le bâtiment naval armé, les deux bâtiments non armés suivant la frégate de façon plus rapprochée. Le bâtiment important armé a de puissants moyens de défense pour se protéger, c'est par exemple un porte-avions, mais il nécessite néanmoins d'être défendu par une première barrière de défense constituée de la frégate. Cette dernière doit par exemple supprimer 80 % des dangers.A set of ships liable to be attacked by hostile aircraft consists, for example, of a frigate, a large armed naval vessel and several large naval vessels that are not necessarily armed. The frigate is for example followed at a distance of approximately 15 km for the armed naval vessel, the two unarmed vessels following the frigate more closely. The important armed building has powerful means of defense to protect itself, it is for example an aircraft carrier, but it nevertheless needs to be defended by a first defense barrier consisting of the frigate. The latter must, for example, eliminate 80% of the dangers.

En cas d'attaque aérienne, des systèmes permettent actuellement de prévoir lequel des bâtiments est visé par l'aéronef hostile, ce peut être a priori indifféremment la frégate, le bâtiment important armé ou un des bâtiments importants. Ces systèmes utilisent notamment des radars qui effectuent des mesures échantillonnées de la trajectoire d'un aéronef hostile, par exemple toutes les secondes. A chaque échantillonnage, un vecteur vitesse de l'aéronef est déduit. Une donnée constituée de la position mesurée et de la vitesse de l'aéronef est généralement appelée une piste. Le système de défense utilise la suite des pistes d'un aéronef hostile repéré pour prédire lequel des bâtiments est visé par cet aéronef. Les systèmes actuels présentent encore un taux d'incertitude qui constitue un point faible de leur action de défense antiaérienne.In the event of an air attack, systems currently make it possible to predict which of the buildings is targeted by the hostile aircraft, this can a priori be the frigate, the large armed building or one of the large buildings. These systems notably use radars which perform sampled measurements of the trajectory of a hostile aircraft, for example every second. At each sampling, a speed vector of the aircraft is deduced. A datum consisting of the measured position and the speed of the aircraft is generally called a track. The defense system uses the sequence of tracks of a spotted hostile aircraft to predict which of the buildings is targeted by this aircraft. Current systems still have a level of uncertainty which constitutes a weak point in their anti-aircraft defense action.

Le document US 2016/0131455 A1 divulgue une méthode pour déterminer la trajectoire d'un aéronef hostile vers une cible donnée.The document US 2016/0131455 A1 discloses a method for determining the course of a hostile aircraft towards a given target.

Le but de l'invention est notamment de réduire ce taux d'incertitude.The object of the invention is in particular to reduce this degree of uncertainty.

A cet effet, l'invention a pour objet un procédé de prédiction, à un instant donné, de la trajectoire d'un aéronef hostile vis-à-vis de bâtiments, ledit aéronef hostile (H) présente un angle de cap Ψ à l'instant considéré et est situé à une distance D d'un point d'objectif prédit qui correspond au bâtiment ayant la plus forte probabilité d'être visé par l'aéronef en fonction des paramètres de vol de ce dernier à l'instant considéré, ou qui est le barycentre des positions des bâtiments susceptibles d'être visés par l'aéronef hostile, pondérés par leur probabilité d'être visés par ce dernier, caractérisé en ce que la trajectoire prédite est définie à partir d'une extrapolation d'un type de trajectoire donné et relie la position de l'aéronef hostile à un point d'impact fictif, le point d'impact fictif étant défini, en fonction du point d'objectif prédit visé par l'aéronef, de façon à réduire la courbure de la trajectoire prédite compte tenu de l'angle de cap Ψ de l'aéronef et de la distance D entre l'aéronef et le point d'objectif prédit à l'instant considéré, la trajectoire prédite étant ensuite fournie à des moyens de calcul d'un missile de défense aérienne de façon à déterminer son point d'interception avec l'aéronef hostile sur ladite trajectoire prédite.To this end, the subject of the invention is a method for predicting, at a given instant, the trajectory of a hostile aircraft vis-à-vis buildings, said hostile aircraft (H) has a heading angle Ψ at moment considered and is located at a distance D from a predicted target point which corresponds to the building having the highest probability of being targeted by the aircraft according to the flight parameters of the latter at the moment considered, or which is the barycenter of the positions of the buildings likely to be targeted by the hostile aircraft, weighted by their probability of being targeted by the latter, characterized in that the predicted trajectory is defined from an extrapolation of a given type of trajectory and connects the position of the hostile aircraft to a fictitious point of impact, the fictitious point of impact being defined, according to the predicted objective point aimed by the aircraft, so as to reduce the curvature of the predicted trajectory taking into account the heading angle Ψ of the aircraft and the distance this D between the aircraft and the predicted target point at the instant considered, the predicted trajectory then being supplied to calculation means of an air defense missile so as to determine its point of interception with the aircraft hostile on said predicted trajectory.

L'invention a pour principaux avantages qu'elle s'applique pour contrer de nombreux types d'aéronefs hostiles, qu'elle s'adapte à différents types de trajectoires de ces aéronefs et qu'elle peut s'adapter à des systèmes déjà existants.The main advantages of the invention are that it can be applied to counter many types of hostile aircraft, that it adapts to different types of trajectories of these aircraft and that it can adapt to already existing systems. .

D'autres caractéristiques et avantages de l'invention apparaîtront à l'aide de la description qui suit faite en regard des dessins annexés qui représentent :

  • la figure 1 : un ensemble de bâtiments navals et un aéronef hostile repérés par leur position ;
  • la figure 2 : une succession d'étapes pour un exemple de mise en œuvre possible du procédé selon l'invention ;
  • la figure 3 : une décomposition possible d'une première étape du procédé selon l'invention ;
  • la figure 4 : une trajectoire possible d'un aéronef hostile ;
  • la figure 5 : une loi de probabilité élémentaire fonction de l'angle de cap d'un aéronef hostile ;
  • la figure 6 : une évolution possible de vecteurs vitesses d'un aéronef hostile par rapport à un navire donné ;
  • la figure 7 : une trajectoire estimée d'un aéronef hostile et la trajectoire réelle de ce dernier ;
  • les figures 8 et 9 : une illustration d'une méthode possible pour obtenir un point d'impact fictif fonction d'un objectif visé par un aéronef hostile ;
  • la figure 10 : une illustration d'un exemple de loi possible donnant la position du point d'impact fictif précité en fonction de l'angle de cap de l'aéronef ;
  • la figure 11 : les trajectoires de la figure 7 ainsi qu'une trajectoire de l'aéronef tenant compte du point d'impact fictif précité.
Other characteristics and advantages of the invention will appear with the aid of the following description given with regard to the appended drawings which represent:
  • the figure 1 : a set of naval buildings and a hostile aircraft identified by their position;
  • the figure 2 : a succession of steps for an example of possible implementation of the method according to the invention;
  • the picture 3 : a possible breakdown of a first step of the method according to the invention;
  • the figure 4 : a possible trajectory of a hostile aircraft;
  • the figure 5 : an elementary probability law as a function of the heading angle of a hostile aircraft;
  • the figure 6 : a possible evolution of speed vectors of a hostile aircraft with respect to a given ship;
  • the figure 7 : an estimated trajectory of a hostile aircraft and the actual trajectory of the latter;
  • them figures 8 and 9 : an illustration of a possible method to obtain a fictitious point of impact depending on an objective targeted by a hostile aircraft;
  • the figure 10 : an illustration of an example of a possible law giving the position of the aforementioned fictitious point of impact as a function of the heading angle of the aircraft;
  • the figure 11 : the trajectories of the figure 7 as well as a trajectory of the aircraft taking into account the aforementioned fictitious point of impact.

La figure 1 présente un exemple d'ensemble de bâtiments représentés par leurs points d'emplacement F, C1, C2, HV. Une frégate F devance un bâtiment de haute valeur HV capable de se défendre, un porte-avions par exemple. Une distance d'environ 15 km sépare par exemple la frégate du bâtiment de haute valeur. Deux bâtiments C1, C2, appelés par la suite bâtiments consorts, suivent la frégate. Les bâtiments consorts C1, C2 sont par exemple situés dans une zone circulaire de 6,5 km de rayon centrée sur la frégate F. En cas d'alerte, la frégate ne peut remplir sa mission que si elle connaît ce que vise un aéronef hostile, d'où la nécessité de prédire la cible visée.The figure 1 presents an example of a set of buildings represented by their location points F, C1, C2, HV. A frigate F is ahead of a building with a high HV value capable of defending itself, an aircraft carrier for example. A distance of about 15 km separates, for example, the frigate from the high-value building. Two buildings C1, C2, subsequently called consort buildings, follow the frigate. The consort buildings C1, C2 are for example located in a circular zone of 6.5 km radius centered on the frigate F. In the event of an alert, the frigate can only fulfill its mission if it knows what a hostile aircraft is aiming for. , hence the need to predict the intended target.

La figure 1 présente à un instant donné, par un point H, la position d'un aéronef hostile. A cet instant, deux trajectoires T1, T2 sont par exemple encore possibles. Il est nécessaire néanmoins de prédire le plus tôt possible quelle est la bonne trajectoire. Une fois la bonne trajectoire définie, celle-ci peut être transmise par exemple à un système de lancement de missiles antiaériens. Connaissant cette trajectoire, des moyens de calcul définissent la trajectoire d'un missile de telle sorte que celle-ci rencontre la trajectoire prédite de l'aéronef hostile, le point d'impact entre les deux engins ayant lieu à l'intersection des deux trajectoires. Les aéronefs hostiles sont par exemple des missiles présentant de grandes facilités de manœuvres, notamment pour des virages courts.The figure 1 presents at a given instant, through a point H, the position of a hostile aircraft. At this instant, two trajectories T1, T2 are for example still possible. However, it is necessary to predict the correct trajectory as soon as possible. Once the correct trajectory has been defined, it can be transmitted, for example, to an anti-aircraft missile launching system. Knowing this trajectory, calculation means define the trajectory of a missile in such a way that the latter meets the predicted trajectory of the hostile aircraft, the point of impact between the two machines taking place at the intersection of the two trajectories . Hostile aircraft are for example missiles with great maneuverability, especially for short turns.

La figure 2 illustre des étapes principales pour la mise en œuvre du procédé selon l'invention.The figure 2 illustrates the main steps for implementing the method according to the invention.

Une première étape 1 prédit un point d'objectif visé par un aéronef repéré, notamment hostile.A first step 1 predicts an objective point targeted by a spotted, in particular hostile, aircraft.

Une deuxième étape 2 détermine un point d'impact fictif fonction du point prédit d'objectif visé.A second step 2 determines a fictitious point of impact as a function of the predicted target target point.

Enfin, une troisième étape 3 détermine une trajectoire de l'aéronef finissant sur le point d'impact fictif précédemment déterminé.Finally, a third step 3 determines a trajectory of the aircraft ending on the previously determined fictitious point of impact.

Cette trajectoire est par la suite prise en compte par des moyens antiaériens, un missile par exemple, pour définir un point de rencontre entre ce dernier et l'aéronef hostile à qui est attribuée cette trajectoire, la destruction de l'aéronef hostile se faisant par exemple en ce point de rencontre. Faire appel à un point d'impact fictif pour définir la trajectoire de l'aéronef repéré et non pas faire appel au point d'objectif prédit, améliore en fait les chances de succès de frapper un aéronef hostile. En effet, une fois le point d'objectif de l'aéronef prédit, plusieurs trajectoires sont possibles entre cet aéronef et le point d'objectif prédit. Toutes ces trajectoires ne peuvent pas par exemple être mémorisées par les moyens de calcul associés à un missile antiaérien, ces moyens de calcul définissant notamment à partir d'une trajectoire prédite de l'aéronef le point de rencontre de celui-ci avec le missile. Selon l'invention, une seule trajectoire peut par exemple être mémorisée par les moyens de calcul tandis qu'en jouant sur une des extrémités de cette trajectoire, le point de rencontre calculé sur cette trajectoire peut effectivement correspondre à la rencontre réelle du missile ou de tout autre moyen de défense antiaérienne et de l'aéronef hostile. Un objectif du procédé selon l'invention est donc de fournir au missile antiaérien, à partir d'informations radar et de la position des navires, la position prédite de l'impact entre un aéronef hostile et le missile de façon à favoriser l'interception de l'aéronef hostile.This trajectory is then taken into account by anti-aircraft means, a missile for example, to define a meeting point between the latter and the hostile aircraft to which this trajectory is attributed, the destruction of the hostile aircraft being done by example at this meeting point. Using a fictitious point of impact to define the trajectory of the spotted aircraft and not using the predicted objective point, in fact improves the chances of hitting a hostile aircraft. Indeed, once the objective point of the predicted aircraft, several trajectories are possible between this aircraft and the predicted objective point. All these trajectories cannot for example be memorized by the calculation means associated with an anti-aircraft missile, these calculation means defining in particular from a predicted trajectory of the aircraft the meeting point of the latter with the missile. According to the invention, a single trajectory can for example be memorized by the calculation means while by acting on one of the ends of this trajectory, the meeting point calculated on this trajectory can effectively correspond to the actual meeting of the missile or of any other air defenses and hostile aircraft. One objective of the method according to the invention is therefore to provide the anti-aircraft missile, based on radar information and the position of the ships, with the predicted position of the impact between a hostile aircraft and the missile so as to promote the interception hostile aircraft.

La figure 3 illustre un exemple de mise en œuvre possible du procédé selon l'invention par deux sous-étapes 11, 12, une première sous-étape 11 de classement des navires potentiellement attaquables suivie d'une deuxième sous-étape de détermination de l'objectif visé.The picture 3 illustrates an example of a possible implementation of the method according to the invention by two sub-steps 11, 12, a first sub-step 11 of classifying potentially attackable ships followed by a second sub-step of determining the targeted objective .

Un des buts de la première sous-étape 11 est de classer les navires potentiels en fonction de leur probabilité d'être visés par l'aéronef hostile. Les critères pour définir une trajectoire de l'aéronef sont par exemple les suivants :

  • l'accélération maximale de l'aéronef hostile ;
  • l'alignement de la trajectoire ou du vecteur vitesse de l'aéronef avec la ligne de visée ;
  • la distance entre l'hostile et son but ;
  • la détection de manœuvre.
One of the aims of the first sub-step 11 is to classify the potential ships according to their probability of being targeted by the hostile aircraft. The criteria for defining a trajectory of the aircraft are for example the following:
  • the maximum acceleration of the hostile aircraft;
  • the alignment of the trajectory or the velocity vector of the aircraft with the line of sight;
  • the distance between the enemy and its goal;
  • maneuver detection.

Concernant l'accélération maximale de l'aéronef hostile, celui-ci est supposé ne pas pouvoir dépasser une accélération maximale notée Γ max par exemple égale à 10 g, g étant l'accélération de la pesanteur. Cette limitation de l'accélération permet de ne pas prendre en considération les navires trop improbables dans la mesure où l'accélération maximale donne le rayon de courbure minimum de l'aéronef.Concerning the maximum acceleration of the hostile aircraft, the latter is assumed not to be able to exceed a maximum acceleration noted Γ max for example equal to 10 g, g being the acceleration due to gravity. This limitation of the acceleration makes it possible not to take into consideration ships that are too improbable insofar as the maximum acceleration gives the minimum radius of curvature of the aircraft.

Une trajectoire cubique de l'aéronef hostile est par exemple définie dans le plan horizontal (x, y) par la relation cubique suivante : y = ax 3 + bx 2 + cx + d

Figure imgb0001
A cubic trajectory of the hostile aircraft is for example defined in the horizontal plane ( x , y ) by the following cubic relation: there = ax 3 + bx 2 + cx +
Figure imgb0001

La figure 4 présente dans le plan (x, y) la position O d'un bâtiment analysé et la position D d'un aéronef hostile, tous les bâtiments étant analysés successivement. La courbe 41 représente une trajectoire cubique, répondant à la relation (1), pour laquelle la définition des conditions aux limites permet de définir les coefficients de la relation (1). L'aéronef présente un vecteur vitesse V faisant un angle Ψ avec la droite x passant par les points O et D précités, tel que la distance OD vaut D.
on a alors : Ψ = 0,5 a r c sin 2 Γ 0 D 3 V 2

Figure imgb0002
The figure 4 presents in the plane ( x , y ) the position O of an analyzed building and the position D of a hostile aircraft, all the buildings being analyzed successively. Curve 41 represents a cubic trajectory, corresponding to relation (1), for which the definition of the boundary conditions makes it possible to define the coefficients of relation (1). The aircraft has a speed vector V making an angle Ψ with the line x passing through the aforementioned points O and D, such that the distance OD equals D.
we then have: Ψ = 0.5 has r vs sin 2 Γ 0 D 3 V 2
Figure imgb0002

Par conséquent, un navire n'est plus atteignable par l'aéronef hostile si l'angle Ψ est supérieur en valeur absolue à l'angle Ψ max = 0,5 a r c sin 2 Γ max D 3 V 2

Figure imgb0003
Γ max étant l'accélération maximale de l'aéronef.Consequently, a ship is no longer reachable by the hostile aircraft if the angle Ψ is greater in absolute value than the angle Ψ max = 0.5 has r vs sin 2 Γ max D 3 V 2
Figure imgb0003
Γ max being the maximum acceleration of the aircraft.

Les navires qui ne sont plus atteignables ne sont pas pris en compte dans le classement des navires potentiels.Ships that are no longer reachable are not taken into account in the ranking of potential ships.

Concernant l'alignement de la trajectoire ou du vecteur vitesse de l'aéronef avec la ligne de visée, un principe retenu consiste par exemple à associer à un navire une probabilité Pcap d'autant plus forte que le cap de la piste de l'aéronef par rapport au bâtiment analysé est faible.Concerning the alignment of the trajectory or of the speed vector of the aircraft with the line of sight, a principle adopted consists for example in associating with a ship a probability Pcap which is all the greater as the heading of the runway of the aircraft compared to the building analyzed is low.

Si le cap de la piste par rapport au bâtiment analysé est noté Ψ, selon le principe retenu précédemment, si Ψ est supérieur à l'angle Ψmax défini par la relation (3) précédente, la probabilité Pcap est égale à 0. Si Ψ est compris entre Ψmin et Ψmax, la probabilité décroît linéairement de 1 à 0 comme l'illustre la figure 5, elle vaut 1 quant Ψ est inférieur à Ψ min.If the heading of the runway in relation to the building analyzed is denoted Ψ, according to the principle retained previously, if Ψ is greater than the angle Ψmax defined by the relation (3) above, the probability Pcap is equal to 0. If Ψ is between Ψmin and Ψmax, the probability decreases linearly from 1 to 0 as illustrated by the figure 5 , it is 1 when Ψ is less than Ψ min.

Concernant la distance entre l'aéronef hostile et son but, l'hypothèse est par exemple faite que plus une cible est proche d'un navire, plus celui-ci est susceptible d'être visé.Concerning the distance between the hostile aircraft and its target, the assumption is for example made that the closer a target is to a ship, the more the latter is likely to be targeted.

En notant Pdis la probabilité du navire d'être visé par l'aéronef hostile selon le critère distance, Pdis est défini par la relation suivante : Pdis = e d 2 7

Figure imgb0004
avec d = D Df
Figure imgb0005

  • D est la distance de l'aéronef au navire
  • Df est une distance déterminée, par exemple Df =5.000m
By noting Pdis the probability of the ship being targeted by the hostile aircraft according to the distance criterion, Pdis is defined by the following relationship: Pdis = e 2 7
Figure imgb0004
with = D df
Figure imgb0005
  • D is the distance from the aircraft to the ship
  • Df is a determined distance, for example Df =5.000 m

La relation (4) assure alors ainsi une discrimination assez sévère en distance entre 5 km et 15 km.Relation (4) thus ensures a fairly severe discrimination in distance between 5 km and 15 km.

Concernant la détection de manœuvre, l'objectif est de déterminer quels sont les navires vers lesquels se déroule la manœuvre de l'aéronef hostile. Cette détection repose par exemple sur l'exploitation des résultats d'une régression linéaire sur les dernières positions estimées. Le but de la régression linéaire sur les dernières positions estimées permet de se mettre autant que possible à l'abri d'une erreur d'estimation de la direction prise par l'aéronef hostile. Seule par exemple la fenêtre contenant les quatre dernières positions estimées par le radar multifonctions est considérée.With regard to maneuver detection, the objective is to determine which ships the maneuver of the hostile aircraft is taking place towards. This detection is based for example on the exploitation of the results of a linear regression on the last estimated positions. The purpose of the linear regression on the last estimated positions makes it possible to shelter as much as possible from an error in estimating the direction taken by the hostile aircraft. Only for example the window containing the last four positions estimated by the multifunction radar is considered.

La figure 6 illustre le critère de détection de manœuvre. Un aéronef hostile H présente successivement trois vecteurs vitesses V 1, V 2, V 3. Plus le vecteur vitesse de l'aéronef s'approche de la droite 61, passant par le navire Ni considéré et l'aéronef, plus la probabilité Pm, appelée probabilité de manœuvre, augmente. La probabilité de manœuvre dépend par exemple de la position relative des trois derniers vecteurs vitesses V 1, V 2, V 3 par rapport la droite précitée 61, cette probabilité augmentant quand ces vecteurs se rapprochent successivement de la droite, c'est-à-dire que l'angle qu'ils font avec la droite diminue.The figure 6 illustrates the maneuver detection criterion. A hostile aircraft H successively presents three speed vectors V 1 , V 2 , V 3 . The more the speed vector of the aircraft approaches the straight line 61, passing through the ship Ni considered and the aircraft, the more the probability Pm , called probability of maneuver, increases. The maneuver probability depends for example on the relative position of the last three speed vectors V 1 , V 2 , V 3 with respect to the aforementioned straight line 61, this probability increasing when these vectors successively approach the straight line, that is to say that the angle they make with the straight line decreases.

Dès qu'un vecteur vitesse V 4 franchit la droite, c'est-à-dire que son angle relatif avec celle-ci change de signe, la probabilité Pm se fige à 1, c'est-à-dire qu'elle n'intervient plus dans la combinaison avec les autres critères. Pour réduire la sensibilité à des valeurs erronées, la probabilité Pm est figée à 1 par exemple après un nombre donné de vecteurs vitesse V 4 successifs de l'aéronef situé du même côté de la droite ; ce nombre peut être égal par exemple à 3.As soon as a velocity vector V 4 crosses the line, i.e. its relative angle with it changes sign, the probability Pm freezes at 1, i.e. it no longer intervenes in the combination with the other criteria. To reduce the sensitivity to erroneous values, the probability Pm is fixed at 1 for example after a given number of speed vectors V 4 successive aircraft located on the same side of the right; this number can be equal for example to 3.

Le classement des navires se fait, en combinant pour chacun d'eux les résultats des trois probabilités précédemment définies Pcap , Pdis et Pm. The classification of ships is done by combining for each of them the results of the three previously defined probabilities Pcap , Pdis and Pm.

Ainsi pour le navire n°i, sa probabilité Pv(i) d'être visé est égale au produit Pcap(i), Pdis(i), Pm(i). Thus for vessel n°i, its probability Pv ( i ) of being targeted is equal to the product Pcap ( i ), Pdis ( i ), Pm ( i ) .

Les navires sont par exemple classés selon la probabilité Pv = Pcap × Pdis × Pm .

Figure imgb0006
For example, ships are ranked according to the probability HP = P cap × Pdis × PM .
Figure imgb0006

Pour la deuxième sous-étape 12 de détermination de l'objectif visé, deux possibilités sont par exemple possibles.For the second sub-step 12 of determining the targeted objective, two possibilities are for example possible.

La première possibilité consiste simplement à retenir le navire ayant la probabilité d'être visé Pv la plus élevée.The first possibility consists simply in retaining the ship with the highest probability of being targeted Pv .

La seconde possibilité consiste à réaliser le calcul d'un barycentre à partir de la position de chaque navire pondérée par sa probabilité d'être visé Pv, le barycentre calculé étant alors considéré comme le point visé par l'aéronef. Cette seconde solution permet notamment d'éliminer des discontinuités.The second possibility consists in carrying out the calculation of a barycenter from the position of each ship weighted by its probability of being targeted Pv , the calculated barycenter then being considered as the point targeted by the aircraft. This second solution makes it possible in particular to eliminate discontinuities.

Dans le cas de quatre navires potentiels, la position O de l'objectif visé est alors par exemple donné par la relation suivante : O = i = 1 4 Pv i . X i i = 1 4 Pv i

Figure imgb0007
X (i) indiquant la position du ième navire.In the case of four potential vessels, the position O of the targeted objective is then for example given by the following relationship: O = I = 1 4 HP I . X I I = 1 4 HP I
Figure imgb0007
X ( i ) indicating the position of the i th vessel.

Une fois réalisée la première étape 1 de prédiction d'un objectif visé par l'aéronef, la deuxième étape 2 détermine un point d'impact fictif fonction de cet objectif prédit, cet objectif pouvant être par exemple le navire de plus forte probabilité d'être visé ou le barycentre tel que calculé précédemment.Once the first step 1 of predicting a target targeted by the aircraft has been carried out, the second step 2 determines a fictitious point of impact as a function of this predicted target, this target possibly being for example the ship with the highest probability of be targeted or the barycenter as previously calculated.

Il a été vu précédemment que la trajectoire d'un hostile a été approximée à bord d'un missile de défense, par exemple, par une trajectoire cubique 41.It was seen previously that the trajectory of a hostile was approximated on board a defense missile, for example, by a cubic trajectory 41.

Pour D et Ψ grands, la courbure de la trajectoire cubique est donc importante. Ainsi, comme l'illustre la figure 7, si l'on se place au début de la manœuvre 72 sur la trajectoire 71 d'un aéronef hostile à une distance d'environ 20 km avec un angle de cap Ψ environ égal à 60°, la trajectoire cubique calculée 73 s'éloigne de façon importante de la trajectoire vraie de l'aéronef.For large D and Ψ, the curvature of the cubic trajectory is therefore important. Thus, as illustrated by the figure 7 , if one places oneself at the start of the maneuver 72 on the trajectory 71 of a hostile aircraft at a distance of approximately 20 km with a heading angle Ψ approximately equal to 60°, the calculated cubic trajectory 73 moves away significantly from the true trajectory of the aircraft.

Néanmoins, si les moyens de calcul du missile de défense antiaérienne ne peuvent extrapoler qu'un seul type de trajectoire, en l'occurrence par exemple une trajectoire cubique, la deuxième étape 2 selon l'invention, permet de rapprocher la trajectoire cubique prédite 73 de la trajectoire réelle, notamment en réduisant sa courbure.Nevertheless, if the calculation means of the anti-aircraft defense missile can only extrapolate a single type of trajectory, in this case for example a cubic trajectory, the second step 2 according to the invention, makes it possible to approximate the predicted cubic trajectory 73 of the actual trajectory, in particular by reducing its curvature.

La deuxième étape 2 consiste notamment, à partir de l'objectif visé déterminé lors de l'étape 1, à calculer un point d'impact fictif qui réduit la courbure, en réduisant la distance D et l'angle de cap Ψ lorsque ces derniers sont trop importants. La réduction de la courbure de la trajectoire cubique rapproche ainsi cette dernière de la trajectoire réelle.The second step 2 consists in particular, from the targeted objective determined during step 1, in calculating a fictitious point of impact which reduces the curvature, by reducing the distance D and the heading angle Ψ when these latter are too important. Reducing the curvature of the cubic trajectory thus brings it closer to the real trajectory.

Le point d'impact fictif est par exemple situé sur le segment de droite compris entre l'objectif visé prédit et la projection orthogonale de cet objectif prédit sur la droite portée par le vecteur vitesse de l'aéronef hostile comme l'illustre la figure 8. L'objectif visé prédit est par exemple soit le navire ayant la plus forte probabilité d'être visé, soit le barycentre des navires pondérés de leurs probabilités d'être visés.The fictitious point of impact is for example located on the line segment between the predicted target target and the orthogonal projection of this predicted target on the line carried by the speed vector of the hostile aircraft as illustrated by the figure 8 . The predicted targeted objective is for example either the ship having the highest probability of being targeted, or the barycenter of the vessels weighted by their probabilities of being targeted.

Dans un système d'axes horizontaux perpendiculaires qui ne sont plus orientés comme ceux de la figure 4, la figure 8 représente par un point P et un vecteur V , la position et le vecteur vitesse d'un aéronef hostile, le couple (P, V ) étant encore appelé piste comme il a été vu précédemment.In a system of perpendicular horizontal axes which are no longer oriented like those of the figure 4 , the figure 8 represented by a point P and a vector V , the position and velocity vector of a hostile aircraft, the torque ( P , V ) being still called track as seen previously.

La deuxième étape détermine par exemple un point d'impact fictif I situé sur le segment de droite 81 compris entre la position 0 de l'objectif prédit, situé par exemple au centre du système d'axes x, y, et la projection orthogonale N de cet objectif sur la droite 82 passant par la position P de l'aéronef et portée par son vecteur vitesse V . Ce point d'impact fictif est utilisé comme nouvelle condition aux limites pour définir la trajectoire cubique prédite, partant du fait que cette trajectoire finit en ce point d'impact fictif. L'allure de la courbure est donnée par la relation (5) et la diminution de D et Ψ en diminue la courbure. La figure 9 montre que la nouvelle distance D' entre l'aéronef et le point d'impact fictif est inférieure à la distance D entre l'objectif prédit et l'aéronef. Il en est de même pour les angles de cap Ψ', Ψ.The second step determines for example a fictitious point of impact I located on the line segment 81 between the position 0 of the predicted objective, located for example at the center of the system of axes x , y , and the orthogonal projection N of this objective on the straight line 82 passing through the position P of the aircraft and carried by its speed vector V . This fictitious point of impact is used as a new boundary condition to define the predicted cubic trajectory, starting from the fact that this trajectory ends at this fictitious point of impact. The shape of the curvature is given by relation (5) and the decrease in D and Ψ decreases the curvature. The figure 9 shows that the new distance D ' between the aircraft and the fictitious point of impact is less than the distance D between the predicted target and the aircraft. The same is true for the heading angles Ψ', Ψ.

La position du point d'impact fictif I sur le segment [ON] 81, est donné par la relation suivante : OI = αON

Figure imgb0008
The position of the fictitious point of impact I on the segment [ ON ] 81, is given by the following relation: OI = αON
Figure imgb0008

D'après les caractéristiques de la trajectoire cubique, le coefficient α est fonction de la distance D et de l'angle de cap Ψ. Ce coefficient α peut par exemple être défini en négligeant l'influence de la distance D. Cela peut être notamment permis par le fait que les cibles concernées sont par exemple situées entre 5 km et 15 km, dans cette plage de distance seule l'influence de l'angle de cap Ψ étant prépondérante.According to the characteristics of the cubic trajectory, the coefficient α is a function of the distance D and the heading angle Ψ. This coefficient α can for example be defined by neglecting the influence of the distance D . This may in particular be permitted by the fact that the targets concerned are for example located between 5 km and 15 km, in this distance range only the influence of the heading angle Ψ being preponderant.

La figure 10 illustre par un diagramme un exemple de détermination possible du coefficient α représenté en ordonnée en fonction de l'angle de cap Ψ représenté en abscisse.The figure 10 illustrates by a diagram an example of possible determination of the coefficient α represented on the ordinate as a function of the heading angle Ψ represented on the abscissa.

Aux petits angles Ψ, par exemple pour Ψ<20°, l'utilisation d'un point d'impact I ne se justifie par exemple pas. Dans ce cas α = 0, I = 0. II n'y a pas de point d'impact fictif. Le point d'impact pris en compte est l'objectif visé prédit.At small angles Ψ, for example for Ψ<20°, the use of an impact point I is not justified, for example. In this case α =0 , I =0. There is no fictitious point of impact. The point of impact taken into account is the predicted target objective.

Quand l'angle Ψ est supérieur à 70° par exemple, le coefficient α est limité par exemple à 0,5, notamment pour ne pas trop réduire la longueur de la trajectoire cubique. En effet, le temps que met l'aéronef hostile pour parcourir la trajectoire cubique jusqu'au point d'impact fictif doit être suffisamment grand pour permettre à un missile antiaérien de calculer le temps d'interception. Dans ce cas, le point d'impact fictif I est situé sur la première moitié du segment [ON] en partant de la position O de l'objectif visé prédit.When the angle Ψ is greater than 70° for example, the coefficient α is limited for example to 0.5, in particular so as not to reduce the length of the cubic trajectory too much. Indeed, the time taken by the hostile aircraft to travel the cubic trajectory to the fictitious point of impact must be large enough to allow an anti-aircraft missile to calculate the interception time. In this case, the fictitious point of impact I is located on the first half of the segment [ ON ] starting from position O of the predicted target objective.

La figure 11 reprend les trajectoires 71, 73 de la figure 7. Une nouvelle trajectoire cubique 101 est calculée dans la troisième étape 3 du procédé selon l'invention en tenant compte d'un point d'impact fictif tel que défini précédemment. Le rayon de courbure de la nouvelle trajectoire cubique 101 ayant nettement diminué par rapport à la première trajectoire cubique 73, cette nouvelle trajectoire cubique s'est considérablement rapprochée de la trajectoire réelle.The figure 11 resumes trajectories 71, 73 of the figure 7 . A new cubic trajectory 101 is calculated in the third step 3 of the method according to the invention taking into account a fictitious point of impact as defined above. The radius of curvature of the new cubic trajectory 101 having clearly decreased compared to the first cubic trajectory 73, this new cubic trajectory is considerably closer to the real trajectory.

La trajectoire 101 ainsi définie est ensuite fournie par exemple à un missile antiaérien dont les moyens de calcul vont déterminer son point d'interception avec l'aéronef sur cette même trajectoire.The trajectory 101 thus defined is then supplied, for example, to an anti-aircraft missile whose calculation means will determine its point of interception with the aircraft on this same trajectory.

La mise en œuvre du procédé selon l'invention a été illustrée pour la défense antiaérienne de navires. Néanmoins, le procédé selon l'invention peut s'appliquer à la défense antiaérienne d'un ensemble de bâtiments terrestres, mobiles ou non.The implementation of the method according to the invention has been illustrated for the anti-aircraft defense of ships. Nevertheless, the method according to the invention can be applied to the anti-aircraft defense of a set of land buildings, mobile or not.

Claims (16)

  1. A method for predicting, at a given instant, the trajectory of a hostile aircraft (H) with respect to vessels (HV, C1, C2, F), said hostile aircraft (H) having a heading angle Ψ at the considered instant and being located at a distance D from a predicted objective point (O) that corresponds to the vessel (HV, C1, C2, F) with the highest likelihood of being targeted by the aircraft (H) as a function of the flight parameters of said aircraft at the considered instant or that is the barycentre of the positions of the vessels (HV, C1, C2, F) likely to be targeted by the hostile aircraft (H), weighted by their likelihood of being targeted by said aircraft, characterised in that the predicted trajectory (101) is defined on the basis of an extrapolation of a given type of trajectory and connects the position of the hostile aircraft to a fictitious point of impact (I), the fictitious point of impact being defined, as a function of the predicted objective point (O) targeted by the aircraft (H), so as to reduce the curvature of the predicted trajectory taking into account the heading angle Ψ of the aircraft and the distance D between the aircraft and the predicted objective point (O) at the considered instant, with the predicted trajectory then being sent to computation means of an air defence missile so as to determine its point of interception with the hostile aircraft (H) on said predicted trajectory.
  2. The method according to claim 1, characterised in that it comprises a first step (1) of predicting an objective point (O) targeted by an aircraft, a second step (2) of determining a fictitious point of impact (I) as a function of the predicted objective point and a third step (3) of determining a trajectory (101) ending at the fictitious point of impact (I).
  3. The method according to claim 2, characterised in that the first step (1) comprises a first sub-step (11) of classifying the vessels (HV, C1, C2, F) as a function of their likelihood of being targeted by the hostile aircraft (H).
  4. The method according to claim 3, characterised in that the likelihood is a function of the maximum acceleration of the hostile aircraft (H).
  5. The method according to any one of claims 3 or 4, characterised in that the likelihood is a function of the heading angle Ψ of the hostile aircraft (H) defined by the angle formed by the velocity vector of the aircraft with its line of sight.
  6. The method according to any one of claims 3 to 5, characterised in that the likelihood is a function of the distance from the hostile aircraft (H) to the vessel (HV, C1, C2, F).
  7. The method according to any one of claims 3 to 6, characterised in that the likelihood is a function of a manoeuvring likelihood (Pm), which itself is a function of the evolution of the velocity vector relative to the straight line connecting the hostile aircraft (H) to the vessel, with the likelihood increasing when the vector approaches this straight line, and remaining set at 1 when it crosses the straight line.
  8. The method according to claim 7, characterised in that the manoeuvring likelihood (Pm) sets at 1 after a given number of successive velocity vectors ( V 4)has remained on the same side of the straight line.
  9. The method according to any one of the preceding claims, characterised in that the fictitious point of impact (I) is located on the straight line segment (81) ranging between the predicted objective point (O) and the projection (N) of this point on the straight line (82) covered by the velocity vector ( V ) of the hostile aircraft (H).
  10. The method according to claim 9, characterised in that, when the heading angle Ψ of the hostile aircraft (H) is large, the fictitious point of impact (I) forms the middle of the segment (81).
  11. The method according to any one of claims 9 or 10, characterised in that, when the heading angle Ψ of the hostile aircraft (H) is small, the fictitious point of impact (I) is equal to the predicted objective point (O).
  12. The method according to any one of claims 9 to 11, characterised in that, when the heading angle Ψ ranges between two given angles, the position of the fictitious point of impact (I) varies from the predicted objective point (O) for the smallest heading angle Ψ to the middle of the segment (61) for the largest heading angle Ψ.
  13. The method according to claim 12, characterised in that the position of the fictitious point of impact (I) varies linearly as a function of the heading angle Ψ.
  14. The method according to any one of claims 12 to 13, characterised in that the position of the fictitious point of impact (I) varies for the heading angles ψ that substantially vary between 20° and 70°.
  15. The method according to any one of the preceding claims, characterised in that the predicted trajectory (101) of the aircraft is defined by a cubic equation.
  16. The method according to any one of the preceding claims, characterised in that the vessels (HV, C1, C2, F) are ships.
EP18175386.4A 2017-06-16 2018-05-31 Method for predicting the trajectory of a hostile aircraft, particularly in the context of anti-air defence Active EP3415860B1 (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR1700646A FR3067840B1 (en) 2017-06-16 2017-06-16 METHOD FOR PREDICTING THE TRAJECTORY OF A HOSTILE AIRCRAFT PARTICULARLY WITHIN THE FRAMEWORK OF ANTI-AIRCRAFT DEFENSE

Publications (2)

Publication Number Publication Date
EP3415860A1 EP3415860A1 (en) 2018-12-19
EP3415860B1 true EP3415860B1 (en) 2022-11-16

Family

ID=62567271

Family Applications (1)

Application Number Title Priority Date Filing Date
EP18175386.4A Active EP3415860B1 (en) 2017-06-16 2018-05-31 Method for predicting the trajectory of a hostile aircraft, particularly in the context of anti-air defence

Country Status (3)

Country Link
EP (1) EP3415860B1 (en)
ES (1) ES2932621T3 (en)
FR (1) FR3067840B1 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111783358B (en) * 2020-07-02 2022-10-04 哈尔滨工业大学 Bayesian estimation-based long-term trajectory prediction method for hypersonic aircraft

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1610152A1 (en) 2004-05-28 2005-12-28 Saab Ab Tracking of a moving object for a self-defence system
US20160131455A1 (en) 2013-05-28 2016-05-12 Bae Systems Bofors Ab Method of fire control for gun-based anti-aircraft defence
KR20160070573A (en) 2014-12-10 2016-06-20 국방과학연구소 Real-time prediction method of impact point of guided missile

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1610152A1 (en) 2004-05-28 2005-12-28 Saab Ab Tracking of a moving object for a self-defence system
US20160131455A1 (en) 2013-05-28 2016-05-12 Bae Systems Bofors Ab Method of fire control for gun-based anti-aircraft defence
KR20160070573A (en) 2014-12-10 2016-06-20 국방과학연구소 Real-time prediction method of impact point of guided missile

Also Published As

Publication number Publication date
EP3415860A1 (en) 2018-12-19
ES2932621T3 (en) 2023-01-23
FR3067840B1 (en) 2022-05-27
FR3067840A1 (en) 2018-12-21

Similar Documents

Publication Publication Date Title
EP2092366B1 (en) Method of estimating the elevation of a ballistic projectile
US8550346B2 (en) Low-altitude low-speed small target intercepting method
US20070250260A1 (en) Method and system for autonomous tracking of a mobile target by an unmanned aerial vehicle
CN105022035A (en) Trajectory target launch point estimate apparatus based on model updating and method
EP3415860B1 (en) Method for predicting the trajectory of a hostile aircraft, particularly in the context of anti-air defence
FR3000238A1 (en) METHOD WITH A SYSTEM FOR DETERMINING AND PREDICTING A MOVEMENT OF A TARGET OBJECT
CN109297497B (en) Method and system for tracing unmanned aerial vehicle controller
FR2978282A1 (en) Method for filtering alarms from on-board ground collision detection system of aircraft in phase of approach of landing strip, involves inhibiting ground alarm when factor is positive and incidence angle is lower than preset threshold
US20140067312A1 (en) Launch Origin and Apparent Acceleration Determination Technique
EP2354753A1 (en) Method for determining the trajectory of a ballistic missile
EP3239656B1 (en) Method for optimising the detection of sea targets and airborne radar implementing such a method
FR3097973A1 (en) RADAR DEVICE FOR THE DETECTION OF REFERENCE BEHAVIOR OF TRACKED TARGETS; PROCESS AND PRODUCT ASSOCIATED COMPUTER PROGRAM
Pohasii et al. UAVs intercepting possibility substantiation: economic and technical aspects
EP2612103A1 (en) Device and method for detecting and neutralizing a naval threat
FR2929700A1 (en) Surface-surface emergency response defense units driving device for e.g. boat, has processing units determining direction proceeded by defense units, from direction data provoking from visual pointing units
FR3050539A1 (en) METHOD FOR OPTIMIZING SHOOTING PERFORMED BY A RADAR IMAGING AIRPORT DEVICE, AND MISSION SYSTEM IMPLEMENTING SAID METHOD
EP0809084B1 (en) Apparatus for determining the roll angle position of a flying device, especially of an ammunition
FR3103305A1 (en) Method and device for predicting at least one dynamic characteristic of a vehicle at a point in a road segment.
FR2619634A1 (en) METHOD AND DEVICE FOR TRACKING TARGET WITH INFRARED EMISSION AND AMMUNITION COMPRISING APPLICATION
FR2569858A1 (en) Display device and method for a system which detects moving objects
WO2019112406A1 (en) Flight planning for an unmanned aircraft guided by a rotary camera with the aim of optimising the search for targets
FR2726360A1 (en) METHOD FOR PRODUCING AN AUTOMATIC IGNITION ORDER FOR AN ANTICHARNE AND IGNITER TRAP FOR IMPLEMENTING THE PROCESS
US12025691B2 (en) Systems and methods for radar detection having intelligent acoustic activation
EP4425211A1 (en) System for classifying radar tracks in animated runways, corresponding to radar traps, and other tracks corresponding to targets of interest such as aircraft or missiles
US20180180385A1 (en) System, method and computer program for timing interceptor missile warhead initiation

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN PUBLISHED

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

AX Request for extension of the european patent

Extension state: BA ME

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE

17P Request for examination filed

Effective date: 20190613

RBV Designated contracting states (corrected)

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: EXAMINATION IS IN PROGRESS

17Q First examination report despatched

Effective date: 20210201

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: EXAMINATION IS IN PROGRESS

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: GRANT OF PATENT IS INTENDED

INTG Intention to grant announced

Effective date: 20220714

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE PATENT HAS BEEN GRANTED

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

Free format text: NOT ENGLISH

REG Reference to a national code

Ref country code: CH

Ref legal event code: EP

REG Reference to a national code

Ref country code: DE

Ref legal event code: R096

Ref document number: 602018043051

Country of ref document: DE

REG Reference to a national code

Ref country code: IE

Ref legal event code: FG4D

Free format text: LANGUAGE OF EP DOCUMENT: FRENCH

REG Reference to a national code

Ref country code: AT

Ref legal event code: REF

Ref document number: 1531998

Country of ref document: AT

Kind code of ref document: T

Effective date: 20221215

REG Reference to a national code

Ref country code: ES

Ref legal event code: FG2A

Ref document number: 2932621

Country of ref document: ES

Kind code of ref document: T3

Effective date: 20230123

REG Reference to a national code

Ref country code: SE

Ref legal event code: TRGR

REG Reference to a national code

Ref country code: LT

Ref legal event code: MG9D

REG Reference to a national code

Ref country code: NL

Ref legal event code: MP

Effective date: 20221116

REG Reference to a national code

Ref country code: AT

Ref legal event code: MK05

Ref document number: 1531998

Country of ref document: AT

Kind code of ref document: T

Effective date: 20221116

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: PT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20230316

Ref country code: NO

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20230216

Ref country code: LT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20221116

Ref country code: FI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20221116

Ref country code: AT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20221116

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: RS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20221116

Ref country code: PL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20221116

Ref country code: LV

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20221116

Ref country code: IS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20230316

Ref country code: HR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20221116

Ref country code: GR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20230217

P01 Opt-out of the competence of the unified patent court (upc) registered

Effective date: 20230427

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20221116

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SM

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20221116

Ref country code: RO

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20221116

Ref country code: EE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20221116

Ref country code: DK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20221116

Ref country code: CZ

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20221116

REG Reference to a national code

Ref country code: DE

Ref legal event code: R026

Ref document number: 602018043051

Country of ref document: DE

PLBI Opposition filed

Free format text: ORIGINAL CODE: 0009260

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20221116

Ref country code: AL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20221116

PLAX Notice of opposition and request to file observation + time limit sent

Free format text: ORIGINAL CODE: EPIDOSNOBS2

26 Opposition filed

Opponent name: BAE SYSTEMS BOFORS AB

Effective date: 20230807

REG Reference to a national code

Ref country code: CH

Ref legal event code: PK

Free format text: TITRE

PLAB Opposition data, opponent's data or that of the opponent's representative modified

Free format text: ORIGINAL CODE: 0009299OPPO

R26 Opposition filed (corrected)

Opponent name: BAE SYSTEMS BOFORS AB

Effective date: 20230807

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20221116

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

PLBB Reply of patent proprietor to notice(s) of opposition received

Free format text: ORIGINAL CODE: EPIDOSNOBS3

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MC

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20221116

REG Reference to a national code

Ref country code: BE

Ref legal event code: MM

Effective date: 20230531

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MC

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20221116

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20230531

Ref country code: LI

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20230531

Ref country code: CH

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20230531

REG Reference to a national code

Ref country code: IE

Ref legal event code: MM4A

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20230531

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20230531

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: BE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20230531

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20240418

Year of fee payment: 7

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20240416

Year of fee payment: 7

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: ES

Payment date: 20240613

Year of fee payment: 7

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: IT

Payment date: 20240426

Year of fee payment: 7

Ref country code: FR

Payment date: 20240422

Year of fee payment: 7

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: SE

Payment date: 20240429

Year of fee payment: 7