EP0161962B1 - Weapon system and missile for destroying the structure of an aeral target using a focussed charge - Google Patents

Abstract

The invention relates to a weapon system intended for the structural destruction of a target. According to the invention, this system comprises computing means which are mounted on board said missile and which, from the values of the velocity Ve of the missile and of the relative target-missile velocity VR, as well as from the angle D between the longitudinal axis of the missile and said relative velocity VR, calculate at an instant close to said instant of detection furnished by proximity detection means, a duration which is then counted down by said computer means from said instant of detection and at the end of which said computer means control said focussed charge.

Description

The present invention relates to a weapon system intended for the structural destruction, that is to say the cutting into two distinct sections, of a target by means of a controlled focused charge and comprising a missile carrying said focused charge .

• soit l'effet de souffle de l'explosion de ladite charge si celle-ci est importante et si la cible se trouve à proximité immédiate ;
• soit la projection, grâce à une charge importante, d'une gerbe d'éclats, largement ouverte, dans des zones sensibles de la cible. De tels systèmes sont par exemple décrits dans les brevets US-A-3 858 207 et US-A-4 168 663.

It is known that the destruction of an air target, such as an attack missile, by direct impact of a defense missile is very improbable, whatever the sophistication of the guidance system of said defense missile. Also, currently, the two main methods by which a defense missile can, by means of a conventional military charge, destroy such an air target, implement

• either the blast effect of the explosion of said charge if it is significant and if the target is in the immediate vicinity;
• or the projection, thanks to a large load, of a spray of shards, widely open, in sensitive areas of the target. Such systems are for example described in patents US-A-3,858,207 and US-A-4,168,663.

These two conventional methods have the drawback of requiring a high military load, so that the defense missiles that they use have a relatively large mass which affects their maneuverability. This is all the more detrimental since the attack missiles can exhibit great maneuverability and it is therefore desirable that the maneuverability of a defense missile is as great as possible to allow the interception of a missile of highly maneuvering attack.

To overcome this drawback of conventional interception methods, it has already been thought to project, from the defense missile and by means of a relatively low charge, a sheaf of shards focused in a fragile area of said target being in the immediate vicinity of said defense missile, in order to obtain the structural destruction of said target, that is to say its sectioning into two distinct sections. Such structural destruction of a target requires that a sufficient number of shards reach together a small area of the target and that the charge used is focused, that is to say that it projects, during the 'explosion, fragments whose trajectories form a substantially constant angle with the axis of the missile.

Such structural destruction allows the use of small missiles carrying only a small or medium charge (of the order of three to four times lower than that required by the first two effects mentioned above) and having great maneuverability, for example obtained by force control, that is to say using lateral nozzles whose line of action passes at least approximately through the center of gravity of the carrier missile. A missile known for a weapon system intended for structural destruction further comprises calculation means, first means capable of providing the value of the speed of said missile, second means capable of providing the value of the relative speed of the target relative to the missile, third means capable of providing the angle between the longitudinal axis of the missile and said relative speed, as well as fourth proximity detection means capable of indicating the instant of detection of an end of said missile target, said missile being provided with a system for triggering said charge activated with a certain delay after detection of the target.

Structural destruction would therefore seem to constitute the most effective method vis-à-vis fast targets with great maneuverability. However, it is not used in practice, because it requires, for the interception to be successful, that the impact area of the focused burst of shrapnel corresponds to a vulnerable area of the target. So far, it does not seem that we have managed to control the impact zone, on a target, of the fragments of a focused spray.

The object of the present invention is to remedy this drawback.

The object of the present invention relates to a weapon system making it possible to send the shards of a focused charge into a zone of the target, specified in advance and chosen for its vulnerability. For an aerial target, such a vulnerable zone corresponds, for example, to the part of the fuselage which is between the wing and the tail.

dans lesquelles :

• T = durée décomptée à partir de l'instant de détection d'une extrémité de la cible par lesdits quatrièmes moyens et au bout de laquelle l'explosion de la charge focalisée est désirée pour que ses éclats atteignent une partie vulnérable prédéterminée de ladite cible ;
• d = distance séparant, le long de l'axe X-X du missile, le centre F des quatrièmes moyens de détection de proximité du centre 0 de la charge focalisée ;
• Io = constante, homogène à une longueur, caractéristique de la cible à détruire
• Ve = vitesse du missile ;
• V_R = vitesse relative de la cible par rapport au missile ;
• D = angle entre l'axe du missile et V_R.

To this end, according to the invention, the weapon system of the type described above is characterized in that it comprises additional calculation means which are mounted on board said missile and which, from the values of the speed of the missile and the target-missile relative speed, as well as from said angle between the longitudinal axis of the missile and said relative speed, calculate at a time close to said detection instant provided by said fourth means a duration, which is then counted by said additional calculation means from said detection instant and at the end of which said additional calculation means control said focused load, said calculation means calculating said duration from the following formulas:

in which :

• T = duration counted down from the instant of detection of one end of the target by said fourth means and at the end of which the explosion of the focused charge is desired so that its fragments reach a predetermined vulnerable part of said target;
• d = distance separating, along the axis XX of the missile, the center F of the fourth proximity detection means from the center 0 of the focused load;
• Io = constant, homogeneous at a length, characteristic of the target to be destroyed
• Ve = speed of the missile;
• V _R = relative speed of the target with respect to the missile;
• D = angle between the axis of the missile and V _R.

It can thus be seen that, according to the invention, the explosion of the focused charge is controlled, from said instant of detection of one end of the target, with a delay time which is calculated as a function of the real parameters of the interception of the target by the missile and which, in reality, corresponds to a predetermined length of said target from its end detected by said fourth means.

In this way, the fragments of the focused charge can reach the predetermined region of said target in order to achieve structural destruction of the latter. In the event that this calculated duration is zero or negative, the firing will be carried out immediately.

It will be noted that the known missiles, as described for example in the patents US-A-3,933,097 and DE-A-2,527,368, are generally provided with a charge trigger system actuated with a certain delay, after detection of the target; however, in this case, this delay is foreseen by construction or possibly introduced during the launching of the missile, taking into account the supposed speed of the target and the type of attack carried out by the missile on the target (attack from the front or rear). On the other hand, according to the invention, the delay in the explosion of the focused charge is determined according to the circumstances of the interception, in order to optimize the effects of said charge and to obtain the structural destruction of the target.

Preferably, said first, second and third means are provided to be able to supply their information continuously and then said additional calculation means calculate said duration continuously to provide a series of values, and, from said detection instant provided by said fourth means, said additional calculation means count down the last value of this duration available before said detection instant.

In known manner, said additional calculation means and / or said proximity detection means exhibit an inherent delay in the exposure of said focused charge and in the detection of a target, respectively. If all of these known delays inherent in the system are equal to (To), said additional calculation means send the focused load a firing signal after a period of time (T _I ), which is equal to the difference between the duration (T), at the end of which the explosion of the focused charge is desired, and the delay duration (To).

Thus, said additional calculation means possibly correct the duration (T) of the value (To) of the inherent delays to provide a firing signal at the expiration of the duration (T,).

In order to be able to supply the constant Io to the calculation means, the system according to the invention includes means capable of indicating this constant. Such means may be display means actuated manually when the missile is launched. Preferably, they consist of automatic means for recognizing the target, either carried by the missile itself, or arranged at a fixed station. In the latter case, these automatic recognition means are advantageously linked to the missile launching and remote control station, which transmits to it by electromagnetic waves the value of to of the target to be destroyed, together with the other information. usual.

It will be noted that at moments very close to interception, that is to say when the missile and the target pass through the same vertical, the relative speed V _R and the angle D between the axis of the missile and this relative speed V _R undergo rapid and insignificant variations: V _R goes through a zero value and D goes through 90 °. Thus, for the calculated explosion delay T _{1 to} have a meaning, it is necessary that the measurements of Ve, V _R and D have been carried out a certain time before the interception, this time having to be neither too large nor too small for V _R and D to represent the real values appreciably despite the accelerations of the missile and the target.

Also, according to an advantageous embodiment of the invention, the value of the duration (T or T _i ) applicable at a given instant is calculated from measurements of the speed (Ve) of the missile, of the target relative speed - missile (V _R ) and of the angle (D) carried out at an earlier instant and said additional calculation means generate an additional delay time t which is counted from the instant of said measurements and whose expiration allows the start from the countdown of the delay (T or T ₁ ) to the ignition of the charge, as soon as the proximity detection means have detected the target.

In practice, Ve, V _R and D are measured and the calculations necessary are carried out at a rate controlled by time t and a delay T, periodically renewed, which is used after detection of the target by the detection means, is developed. proximity, to trigger the charge at the optimal time.

Preferably, said additional delay time t is calculated by said additional calculation means and is proportional to the inverse of the square root of the relative speed (V _R ).

• Les figures du dessin annexé feront bien comprendre comment l'invention peut être réalisée. Sur ces figures, des références identiques désignent des éléments semblables.
• La figure 1 est une vue schématique générale illustrant la mise en oeuvre du système d'arme de défense aérienne selon l'invention.
• La figure 2 montre schématiquement un missile de défense aérienne selon l'invention.
• La figure 3 est une vue schématique montrant deux paramètres intervenant dans l'interception d'une cible par le missile selon l'invention.
• La figure 4 est un schéma représentant l'interception d'une cible par le missile selon l'invention, dans le cas où cette interception est effectuée par l'avant de la cible et où la cible et le missile selon l'invention se trouvent dans un même plan.
• La figure 5 est un diagramme de vitesses pour le schéma de la figure 4.
• La figure 6 est un schéma représentant l'interception d'une cible par le missile selon l'invention, dans le cas où cette interception est effectuée par l'arrière de la cible et où la cible et le missile selon l'invention se trouvent dans un même plan.
• La figure 7 est un diagramme de vitesses pour le schéma de la figure 6.
• La figure donne le schéma synoptique des moyens de calcul du système selon l'invention, embarqués à bord du missile.

Said calculation means can be composed of a first circuit controlling the measurements of the various parameters and carrying out the necessary calculations, a second circuit determining the instant from which the delay time can be used and a third circuit allowing the operation of this delay time. Such calculation means can be constituted, at least in part, by a microprocessor.

• The figures of the appended drawing will make it clear how the invention can be implemented. In these figures, identical references designate similar elements.
• Figure 1 is a general schematic view illustrating the implementation of the air defense weapon system according to the invention.
• FIG. 2 schematically shows an air defense missile according to the invention.
• Figure 3 is a schematic view showing two parameters involved in the interception of a target by the missile according to the invention.
• FIG. 4 is a diagram representing the interception of a target by the missile according to the invention, in the case where this interception is carried out from the front of the target and where the target and the missile according to the invention are found in the same plane.
• Figure 5 is a speed diagram for the diagram in Figure 4.
• FIG. 6 is a diagram representing the interception of a target by the missile according to the invention, in the case where this interception is carried out from the rear of the target and where the target and the missile according to the invention are found in the same plane.
• Figure 7 is a speed diagram for the diagram in Figure 6.
• The figure gives the block diagram of the calculation means of the system according to the invention, on board the missile.

The weapon system according to the invention, shown in FIG. 1 and intended for air defense, comprises a detection and guidance device 1, arranged on the ground, as well as a set of air defense missiles 2. When an air enemy 3 (missile, plane, helicopter, etc.) is detected by the device 1, which determines using the computer and the radar that it includes the opportunity and the conditions for an interception of the enemy 3.

If the interception is decided, the device 1 proceeds to launch a missile 2 against the enemy 3, which then becomes the target to be shot down. As shown diagrammatically in FIG. 2, each air defense missile 2 comprises electronic guide means 4 capable of cooperating with the device 1 and a seeker 5 provided with an inertial unit 5 '. Also, initially, a missile 2 follows a launch trajectory entirely determined by the cooperation of the device 1 and on-board guidance means 4. Then, again thanks to this cooperation, the device 1 directs the missile 2 towards the target 3 by making it follow a trajectory 7. Finally, when the missile 2 is sufficiently well oriented, its guidance towards the target 3 is taken care of by its seeker 5.

It will be noted that, in FIG. 1, we have illustrated the case where the missile 2 goes against the target 3 to attack it from the front, which corresponds to the diagrams of FIGS. 4 and 5. It goes without saying that missile 2 can also attack target 3 from the rear, chasing and catching it, as shown in the diagrams in Figures 6 and 7.

• des moyens de détection de proximité 8 dont le front de détection 9 est voisin d'une surface conique concave d'axe confondu avec l'axe longitudinal X-X dudit missile 2 et d'angle au sommet A ;
• une charge militaire focalisée 10 susceptible de projeter des éclats selon une surface de révolution d'axe confondu avec l'axe longitudinal X-X du missile et d'angle B ;
• des codeurs angulaires 12 disposés sur le bâti de l'autodirecteur 5 ; et
• des moyens de calcul 13 pour la commande de la charge focalisée 10.

Each missile 2 includes:

• proximity detection means 8, the detection front 9 of which is close to a concave conical surface of axis coincident with the longitudinal axis XX of said missile 2 and of angle at the apex A;
• a focused military charge 10 capable of projecting fragments along a surface of revolution of axis coincident with the longitudinal axis XX of the missile and of angle B;
• angular encoders 12 arranged on the frame of the seeker 5; and
• calculation means 13 for controlling the focused load 10.

The object of the invention, as was specified above, is to control the explosion of the focused charge 10 at an instant following the detection of the target 3 by the proximity detection means 8, such as the fragments of said charge 10 reach a structurally fragile region of said target, in order to cut the latter in two. In general, the front and middle parts of an attacking machine 3 are structurally resistant because they include navigation and measuring devices, fuel tanks, military load, etc., so that, in order to obtain structural destruction of said machine 3, it is preferable to project the fragments of the load 10 into a zone 14 of the rear part thereof (see FIGS. 4 and 6). Thus, the object of the invention is to determine a time T of delay in the explosion of the charge 10, after the detection of the target 3 by the proximity detection means 8, such as the bursts of said focused charge 10 can reach zone 14, placed at a distance from the first point 15 of the target 3 detected by the front 9 of said proximity detection means 8.

It will be noted that the explosion of the charge 10 after firing by the calculation means 13 is not instantaneous and that, moreover, there is a delay in the detection of a target 3 by the detection means of proximity 8; as a result, the delay time T to the explosion must be corrected by a time To, known for a charge 10 and proximity detection means 8 given and corresponding to the explosion delays after ignition and detection by proximity detection means 8.

In reality, the firing control instant must take place with a delay time:

• la vitesse Ve du missile de défense aérienne 2 ;
• la vitesse VB de la cible 3 ;

If one seeks to mathematically determine the distance I between the first detected point 15 and the area 14, at least the following parameters must be used:

• the speed Ve of the air defense missile 2;
• the speed VB of the target 3;

• le temps T de retard à l'explosion de la charge focalisée 10 après détection du point 15 de la cible 3 par le front 9 des moyens de détection de proximité 8 ;
• la vitesse Vi des éclats de la charge focalisée 10, projetés selon la surface de révolution 11 ;
• l'angle B de la surface de révolution 11 par rapport à l'axe X-X du missile 2 ;
• l'angle A du front de détection 9 des moyens de détection de proximité 8, par rapport à l'axe X-X du missile 2 ;
• la distance d le long de l'axe X-X du missile 2, entre le cente F des moyens de détection de proximité 8 et le centre 0 de la charge focalisée 10 ;
• la position axiale h du point 15 de la cible 3 détecté par des moyens de détection de proximité 8, par rapport à l'axe X-X du missile 2 ; et
• l'angle a définissant la position angulaire dudit point 15 par exemple par rapport à la direction H-H perpendiculaire commune à Ve et V_B (sur les figures 4 et 5, a = 90°).
• Il va de soi que la connaissance à l'instant de la détection du point 15 par le front 9 de tous les paramètres ci-dessus, sauf T, permet de calculer T pour que 1 ait une valeur donnée à l'avance. Il est donc possible théoriquement d'atteindre une zone 14 déterminée à l'avance, du moins dans le cas où le calcul de T₁ donne un résultat positif. Cependant, en pratique, un tel calcul de T n'est pas possible, car, quoique certains paramètres, tels que Vi, A, B et d, soient connus par construction et que d'autres, tels que Ve, V_B et P, puissent être mesurés sur le missile 2 à des instants proches de l'interception, il subsiste une grande indétermination due à la méconnaissance de h et a.

the angle P of the presentation of the target 3 relative to the missile 2, that is to say the angle between the direction of the speed Ve and that of the speed VB (see FIGS. 5 and 7);

• the time T of delay in the explosion of the focused charge 10 after detection of the point 15 of the target 3 by the front 9 of the proximity detection means 8;
• the speed Vi of the fragments of the focused charge 10, projected along the surface of revolution 11;
• the angle B of the surface of revolution 11 with respect to the axis XX of the missile 2;
• the angle A of the detection front 9 of the proximity detection means 8, with respect to the axis XX of the missile 2;
• the distance d along the axis XX of the missile 2, between the center F of the proximity detection means 8 and the center 0 of the focused load 10;
• the axial position h of point 15 of the target 3 detected by proximity detection means 8, relative to the axis XX of the missile 2; and
• the angle a defining the angular position of said point 15 for example with respect to the perpendicular direction HH common to Ve and V _B (in FIGS. 4 and 5, a = 90 °).
• It goes without saying that knowing at the instant of the detection of point 15 by the edge 9 of all the above parameters, except T, makes it possible to calculate T so that 1 has a value given in advance. It is therefore theoretically possible to reach a zone 14 determined in advance, at least in the case where the calculation of T ₁ gives a positive result. However, in practice, such a calculation of T is not possible because, although some parameters, such as Vi, A, B and d, are known by construction and others, such as Ve, V _B and P , can be measured on missile 2 at times close to interception, there remains a great indeterminacy due to the ignorance of h and a.

tels que :The present invention overcomes this difficulty. Indeed, the Applicant has demonstrated by studying the quantity I, a function of the ten preceding parameters, that it could be written in the form of a sum of three terms:

such as :

Io is a constant, having the dimension of a length and independent of the parameters Ve, V _B and P; lo is attached to each type of target 3 and characteristic of it. The detection and guidance device 1, which performs an at least partial image recognition of the target 3, knows the type of the latter and can therefore send to the calculation means 13 of the missile 2, the value lo suitable for the target 3 being intercepted. The different values 10 respectively correspond to the different types of possible targets are preferably predetermined and stored in the device 1. Each type of target 3 can be associated with a value of 10 for a forward attack and another value lo for a rear attack. Optionally, the missile 2 may include the means for detecting the type of the target 3 and determining the value to be adopted for the constant lo;

Dl ₁ = ± V _B · te, term in which te is the time taken by the bursts of the focused charge 10 to reach zone 14 of the target 3. The + sign is used for a forward attack and the sign - for a rear attack. The detection and guidance device 1 knows the type of attack (from the front or from the rear) that the missile 2 will carry out on the target 3 and it is therefore able to communicate to the calculation means 13 the sign appropriate. Note that te is an implicit function of h, a and T; and

DI ₂ is a variation in length due to the parameters h and a.

The condition for I to be considered as the sum of the terms lo, DI, and D1 ₂ is then as follows:

c'est-à-dire s'il s'agit d'une attaque par l'avant (voir les figures 4 et 5), ou par la formule :

c'est-à-dire s'il s'agit d'une attaque par l'arrière (voir figures 6 et 7).Condition (1) is easy to achieve by construction, since it involves only parameters available to the manufacturer of missile 2. If this condition (1) is met, the delay time T is given by the formula

that is to say if it is an attack from the front (see Figures 4 and 5), or by the formula:

that is to say if it is a rear attack (see Figures 6 and 7).

In addition, the applicant has shown that if the relation (1) is verified at least with a good approximation, the term Dl ₂ remains small before Io and Dl ₁ , at least in a wide range of the parameters Ve, V _B and P and could therefore be overlooked.

Thus, if condition (1) is respected and if the time T has been chosen according to the appropriate relation (2 ₁ ) or (2 ₂ ), the zone 14 reached by the splinters will be defined from point 15, by the relationship :

Consequently, if as a function of the diameter of the area covered by the proximity detection means 8 and considerations of efficiency of structural destruction, a maximum time t _m of travel of the fragments of the focused charge 10 is chosen, one obtains a high probability of hitting target 3 in a zone delimited between Io and lo ± VB · tM.

en appelant V_R, la vitesse relative de la cible 3 par rapport au missile 2 et D, l'angle entre la vitesse Ve du missile et cette vitesse relative V_R. Par suite, on peut écrire :

avec

It will be noted that the calculation of T can be easily carried out on board the missile 2. Indeed, as shown in FIGS. 5 and 7, we have:

by calling V _R , the relative speed of the target 3 relative to the missile 2 and D, the angle between the speed Ve of the missile and this relative speed V _R. As a result, we can write:

with

• V_R est disponible de l'autodirecteur 5, qui comporte par exemple un radar à effet Doppler. La vitesse relative V_R est une donnée toujours présente à bord d'un missile (2), car nécessaire à l'élaboration du guidage en navigation proportionnelle au moyen de l'autodirecteur 5 ;
• Ve peut être connue de plusieurs façons différentes, par exemple à partir de la centrale inertielle 5' de l'autodirecteur (5) du missile 2 ou à partir d'accéléromètres ; elle pourrait également être tabulée en fonction du temps de parcours effectué par ledit missile 2 ;
• l'angle D est donné par les codeurs angulaires 12 disposés sur le bâti de l'autodirecteur 5 ; de tels codeurs sont généralement prévus sur le missile 2, à cause de la nécessité d'orienter préalablement celui-ci (trajectoire 7) avant que la cible 3 puisse être accrochée par l'autodirecteur 5.
• Sur les figures 4 et 7, on a représenté schématiquement une interception avant et une interception arrière et l'on peut y voir qu'à l'instant de l'explosion de la charge localisée 10, le centre 0 de celle-ci se trouve en 0' de façon que les éclats localisés 11 puissent atteindre la zone prédéterminée 14.
• Sur la figure 8, on a représenté un exemple de réalisation des moyens de calcul 13 pour la commande de la charge focalisée 10. Ces moyens 13 sont constitués d'un circuit de mesure et de calcul 16 et de deux compteurs-décompteurs 17 et 18, ainsi que de deux horloges 19 et 20 émettant des impulsions à des cadences respectives c₁ et c₂.

The time T therefore depends only on the three variables V _R , Ve and D, since d and Io are fixed either by construction (d), or by predetermination (lo). Gold :

• V _R is available from the seeker 5, which includes, for example, a Doppler radar. The relative speed V _R is a datum always present on board a missile (2), since it is necessary for the development of guidance in proportional navigation by means of the seeker 5;
• Ve can be known in several different ways, for example from the inertial unit 5 ′ of the seeker (5) of the missile 2 or from accelerometers; it could also be tabulated as a function of the travel time made by said missile 2;
• the angle D is given by the angular encoders 12 arranged on the frame of the seeker 5; such coders are generally provided on the missile 2, because of the need to orient it beforehand (trajectory 7) before the target 3 can be hooked by the seeker 5.
• In FIGS. 4 and 7, a front interception and a rear interception have been shown diagrammatically, and it can be seen there that at the moment of the explosion of the localized charge 10, the center 0 thereof is found. at 0 'so that the localized flakes 11 can reach the predetermined area 14.
• FIG. 8 shows an exemplary embodiment of the calculation means 13 for controlling the focused load 10. These means 13 consist of a measurement and calculation circuit 16 and two up-down counters 17 and 18 , as well as two clocks 19 and 20 emitting pulses at respective rates c ₁ and c ₂ .

Circuit 16 controls the measurements and performs the calculations. The up-down counter 17 determines. the instant from which the explosion delay time can be used, while the up-down counter 18 allows the exploitation of this delay.

• sur l'entrée 21, l'autodirecteur 5 applique un signal indiquant qu'il fonctionne et qu'il a accroché la cible 3 ;
• sur l'entrée 22, une impulsion de l'horloge 19 est présente ;
• le circuit 17 adresse une autorisation de mesure sur l'entrée 23 ;

The circuit 16 has three inputs 21, 22 and 23 respectively connected to the seeker 5, to the clock 19 and to the up-down counter 17, as well as an input 24 and an output 25 connected to the sensors 5, 5 ', 12 and three inputs 26, 27 and 28, respectively for the parameters lo, d and To. It is implemented when the following conditions are met:

• on input 21, the seeker 5 applies a signal indicating that it is operating and that it has caught the target 3;
• on input 22, a pulse from clock 19 is present;
• circuit 17 addresses a measurement authorization on input 23;

• la lecture de Ve, V_R et D sur les capteurs 5, 5' et 12 par l'entrée 24 ;
• le calcul du temps de retard T₁ à la mise à feu et du temps de retard supplémentaire t ;
• le chargement du compteur-décompteur 17 par le temps de retard t ;
• l'autorisation de décrémenter ce compteur-décompteur 17 ;
• la mise en mémoire du temps de retard T_i.

Circuit 16 then successively causes:

• reading of Ve, V _R and D on sensors 5, 5 'and 12 through input 24;
• calculating the delay time T ₁ at ignition and the additional delay time t;
• loading the up-down counter 17 by the delay time t;
• authorization to decrement this up-down counter 17;
• the storage of the delay time T _i .

• initialisation du compteur-décompteur 18 (liaison 30) ;
• chargement de T, dans le compteur-décompteur 18 ;
• autorisation de mesure sur l'entrée 23, pour débloquer le circuit 16.

The up-down counter 17 is initialized to the number of pulses N, = (t / c ₁ ) -1. Its loading by the circuit 16 causes the measurement to be prohibited by the input 23. The up-down counter 17 is decremented by 1 at each pulse of the clock 19 (link 29). When its content becomes negative, the following operations are carried out:

• initialization of the up-down counter 18 (link 30);
• loading of T, in the up-down counter 18;
• measurement authorization on input 23, to unlock circuit 16.

The up-down counter 18 is initialized by the up-down counter 17 at a number of pulses N ₂ = (T1 / c2) -1. It is decremented by 1 at each pulse of the clock 20 (link 31) as soon as the proximity detection means 8 detect the target 3 and send a signal corresponding to the up-down counter 18 by the link 32. When its content is negative , the explosive charge 10 is ignited.

The measurement authorization signal (input 23) is initialized at the time of launching or during the search for seeker 5.

It will be noted that this system makes it possible to keep the last known value of T if the seeker 5 loses the target 3. If the calculation of T leads to a negative number, the delay in explosion is then zero after detection of the target 3 by proximity detection means 8.

Claims (7)

1. Weapon system intended for the structural destruction, i. e.for the cutting off into two distinct sections, of a target (3) by means of a controlled focussed charge (10) and comprising a missile (2) carrying said focussed charge and carrying computing means, first means (5') for furnishing the value of the velocity (Ve) of said missile (2), second means (5) for furnishing the value of the relative velocity (V_R) of the target (3) with respect to said missile (2), third means (12) for furnishing the angle (D) between the longitudinal axis of the missile (2) and said relative velocity, and fourth means (8) for proximity detection, adapted to indicate the instant of detection of one end of said target (3), said missile (2) being provided with a system for triggering the charge actuated with a delay after the detection of the target, characterized in that it comprises additional computing means (13) which are mounted on board said missile (2) and which, from the values of the velocity (Ve) of the missile and of the relative target-missile velocity (V_R), as well as from said angle (D) between the longitudinal axis of the missile (2) and said relative velocity (V_R), calculate at an instant close to said instant of detection furnished by said fourth means (8), a duration (T) which is then counted down by said additional computing means (13) from said instant of detection and at the end of which said additional computing means (13) control said focussed charge (10), said computing means (13) calculating the duration (T) from the following formulae :

in which:

T = duration counted down from the instant of detection of one end of the target (3) by said fourth means (8) and at the end of which the explosion of the focussed charge is desired for its splinters to reach a predetermined vulnerable part of said target (3) ;

d = distance separating, along axis X-X of the missile (2), the centre F of the fourth proximity sensing means (8) from the centre 0 of the focussed charge (10) ;

lo = constant, homogeneous to a length, characteristic of the target (3) to be destroyed ;

Ve = velocity of the missile (2) ;

V_R = relative velocity of the target (3) with respect to the missile (2) ;

D = angle between the axis of the missile (2) and V_R.

2. Weapon system according to claim 1, in which said first, second and third means furnish their information continuously, characterized in that said additional computing means (13) calculate said duration (T) continuously and furnish a series of values thereof, and in that, from said instant of detection furnished by said fourth means, said additional computing means (13) countdown the last value of this duration available before said instant of detection.

3. Weapon system according to one of claims 1 or 2, in which said additional computing means (13) and/or said proximity sensing means present a delay inherent in the explosion of said focussed charge and in the detection of a target (3), respectively, characterized in that if the totality of these known delays inherent in the system is equal to (To), said additional computing means (13) address to the focussed charge (10) a firing signal at the end of a duration (T_I), which is equal to the difference between the duration (T), at the end of which the explosion of the focussed charge is desired, and the duration of delay (To).

4. Weapon system according to claim 1, characterized in that it comprises means (1) adapted to recognize the type of the target (3) and to furnish the constant lo.

5. Weapon system according to one of claims 1 or 4, characterized in that the value of the duration (T or T) applicable at a given instant is calculated from measurements of the velocity (Ve) of the missile, of the relative target-missile velocity (V_R) and of the angle (D), made at an earlier instant, and in that said additional computing means (13) elaborate an additional delay time t which is counted down from the instant of said measurements and of which the expiration allows the beginning of the count-down of the delay (T or T,) of firing of the charge (10), as soon as the proximity sensing means (8) have detected the target (3).

6. Weapon system according to claim 5, characterized in that said supplementary delay time t is calculated by said additional computing means (13) and is proportional to the reciprocal of the square root of the relative speed (V_R).

7. Weapon system according to one of claims 5 or 6, characterized in that said additional computing means (13) are composed of a first circuit (18) controlling the measurements of the different parameters and effecting the necessary calculations, of a second circuit (19) determining the instant from which the duration of delay (T or T,) is exploitable and a third circuit (20) allowing exploitation of this duration of delay (T or T_I).

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