EP0800054B1 - Projectile the warhead of which is triggered by means of a target designator - Google Patents

Description

The technical field of the invention is that of projectiles comprising an explosive charge, the operation of which is triggered by a rocket.

Explosive projectiles are known to generate shrapnel (for example conventional artillery shells). The initiation of these projectiles is most often caused by an impact rocket or a proximity rocket which detects approach to the ground.

These projectiles are intended for attacking light vehicles or for anti-personnel combat. Their effectiveness is reduced due to the great dispersion of both fragments and projectiles. This leads to a high consumption of projectiles, therefore to significant logistics and cost.

In addition, such projectiles cannot be used precisely in an urban type environment. Indeed, they generally use a rocket detecting not the target but the proximity of the ground.

It is not possible to reliably and economically modify such projectiles by providing them with target detection means.

In fact, the known target detection means use radar or infrared technology detectors.

These detectors are expensive and can only be used for attacking targets whose radar or infrared signature is important and well known. They are therefore only used in the context of the anti-tank fight.

Semi-autonomous projectiles are also known (such as the American “Copperhead” projectile), the terminal guidance of which is enabled by means of a laser designation of the targeted target, designation which is ensured by an advanced observer.

The patent US5023888 thus describes a device for coding a signal transmitted by a target designator to a projectile to ensure its guiding towards a target.

Such projectiles are also very expensive due to the complexity of the guidance and piloting functions.

In addition, projectiles are known which are intended for anti-tank combat and which disperse several sub-projectiles at core-generating charge over an area of land on which targets are located.

The sub-projectiles used are generally equipped with radar or infrared technology target detection means. They include a computer which implements complex algorithms allowing the recognition of the target. The document DE4108057 which serves as a basis for the preamble of the main claim describes such a sub-projectile.

These projectiles are very expensive and are reserved for attacking targets whose radar or infrared signature is important and well known.

However, their effectiveness is reduced when the targets are camouflaged or stopped (reduced infrared signature).

They also risk losing their effectiveness due to the possibility of engagement by two different sub-projectiles of a single target.

It is the aim of the invention to propose a projectile with a burst-generating charge and / or a core-generating charge which does not have such drawbacks.

Thus, the projectile according to the invention is inexpensive because it implements simple detection means and it does not impose the use of guidance / piloting means.

The projectile according to the invention allows a precise attack on light targets.

The invention also makes it possible to carry out a precise attack on targets camouflaged or provided with decoy means, and this in both open terrain and urban areas. It thus allows a "surgical strike" of the targets while avoiding maximum collateral damage.

According to different variants, the projectile according to the invention can be defined to act in anti-tank or anti-personnel mode exclusively or alternatively in anti-tank or anti-personnel mode.

Thus the subject of the invention is a projectile comprising at least one explosive charge generating fragments and / or a nucleus and the operation of which is triggered by a rocket, the charge having at least one direction of action and the rocket comprising at least one detector having a detection direction the orientation of which is close to that of a direction of action of the charge, the projectile being intended to be driven by a rotational movement which allows scanning of a area of ground by the directions of detection and action, projectile characterized in that the detector is sensitive to laser radiation reflected by a target and coming from a designator placed on the ground, the detection of laser radiation reflected by a target causing the initiation of the charge.

The rocket may advantageously include means for decoding a signal transmitted by the laser radiation reflected by the target.

The projectile may include an emission means capable of controlling the activation of a laser designator placed on the ground.

According to another embodiment, the charge comprises at least two different operating modes which can be initiated as desired by the rocket.

Advantageously, the means for decoding the rocket can determine the desired operating mode from a signal carried by the laser radiation reflected by the target.

According to another embodiment, the load comprises at least two different directions of action and at least two directions of detection associated with the directions of action.

According to a particular embodiment, the charge is a charge which generates a nucleus.

The projectile may be a sub-projectile dispersed by a vector over a terrain area, it may also be a projectile with a curved trajectory such as an artillery shell or a mortar projectile, or a projectile dropped by aircraft and with a free falling or planing trajectory like a bomb.

The projectile according to the invention may finally be a projectile with a stretched trajectory fired by a tank gun, or a light rocket launcher.

• les figures 1a et 1b représentent de façon schématique la mise en oeuvre sur le terrain d'un projectile selon l'invention,
• la figure 2 est une vue en coupe longitudinale d'un projectile suivant un premier mode de réalisation de l'invention,
• la figure 3 représente une variante de la précédente.
• la figure 4 représente un projectile suivant un deuxième mode de réalisation de l'invention,
• la figure 5 représente un projectile suivant un troisième mode de réalisation de l'invention,
• la figure 6 est une coupe transversale de la charge du projectile selon la figure 5.
• la figure 7 représente un projectile suivant un quatrième mode de réalisation de l'invention.

Other advantages of the invention will appear on reading the following description of different modes , description made with reference to the accompanying drawings and in which:

• FIGS. 1a and 1b schematically represent the implementation on the ground of a projectile according to the invention,
• FIG. 2 is a view in longitudinal section of a projectile according to a first embodiment of the invention,
• Figure 3 shows a variant of the previous one.
• FIG. 4 represents a projectile according to a second embodiment of the invention,
• FIG. 5 represents a projectile according to a third embodiment of the invention,
• FIG. 6 is a cross section of the charge of the projectile according to FIG. 5.
• FIG. 7 represents a projectile according to a fourth embodiment of the invention.

Referring to Figures 1a and 1b, a weapon system 1, such as a howitzer, fires a projectile 2 according to the invention towards a target 3, which is here a command post.

The command post includes several weakly protected targets with high tactical value, such as one or more shelters 4, transmission means 5, light vehicles 6, 7.

These targets, most often camouflaged, have a weak infrared signature and cannot be engaged with known projectiles.

The projectile 2 according to the invention is a cargo projectile which ejects a sub-projectile 2a above the objective 3.

Ejection is controlled in a known manner by a timed rocket programmed before firing.

The sub-projectile 2a is braked by the deployment of a parachute 8, which also gives it a substantially vertical orientation XX ′ with respect to the objective 3. The sub-projectile is driven by a speed of rotation R of the order of 15 revolutions / second around this axis XX '(residual speed given by the cargo projectile 2).

An advanced observer 9 is at a distance from objective 3 of the order of 1 to 2 km. It has a laser designator 10 which allows it to send a thin laser beam 11 to a chosen target 4.

Target 4 reflects part of the beam energy laser to sub-projectile 2a.

This is provided with a directive detector 12 of laser radiation (such as a photodiode), which has an observation direction (d) close to the direction of action (D) of an explosive charge 13 of the sub-projectile 2a.

Due to the rotation of the sub-projectile during its descent, the direction of observation d (as well as the direction of action D) sweep the ground according to spiral curves.

When the detector 12 receives the radiation reflected by the target 4, it causes the initiation of the charge 13 which will have maximum efficiency due to the orientation of its direction of action D towards the target 4.

Figure 2 shows a first embodiment of such a sub-projectile.

This comprises two burst-generating charges 13a, 13b which each have an action direction Da, Db parallel to the direction of observation (d) of the detector 12.

Each shine generating charge 13a, 13b comprises in a known manner an envelope 14, containing an explosive 15, and closed by a weakened coating 16 (for example by electronic bombardment) along a grid.

During the initiation of such a charge, the shock wave communicated to the coating by the explosive causes its dislocation and the projection of splinters.

The curvature given to the coating makes it possible to focus the burst of splinters in the direction of action (Da, Db) which is also the axis of symmetry of the coating and of the load.

The coating will preferably be made of a dense material, such as Tantalum, or of steel.

Each explosive charge 15 is initiated by a detonator primer 17.

The rocket of the sub-projectile 2a comprises a detector 12 whose direction of observation (d) is substantially parallel to the directions of action Da, Db. It also includes a computer 18 and an altimeter 19 (for example a radar altimeter).

Altimeter 19 prohibits ignition of charges explosive if the distance between the sub-projectile and the ground is too great. Thus the signals received by the detector 12 are only taken into account if the sub-projectile is at a sufficiently low distance from the ground for the efficiency of the flash charges to be maximum.

Such an arrangement also makes it possible to protect the sub-projectile against attempts to deceive.

The computer 18 receives the signals transmitted by the detector 12 and it causes the ignition of the charges when a laser beam is reflected towards it by the designated target (if the altimeter authorizes this ignition).

Advantageously, coding can be provided, transmitted by the laser designator 10, and carried by the beam, for example a modulation of the phase or of the frequency of the beam. This coding is received by the detector 12 with the signal reflected by the target and it is detected by the computer 18, which then constitutes a decoding means, and authorizes the firing of the charges only if the coding is present.

This increases the resistance of the sub-projectile to countermeasures implemented possibly around the target (for example laser sources directed towards the sub-projectile).

The characteristics of the laser designator, in particular its power and its emission frequency are a function of the rotation speed of the sub-projectile, the altitude at which the shot can be fired and the angle of inclination of the directions d and D with respect to the vertical.

These parameters will be readily determined by those skilled in the art based on operational needs.

For example, we could use a designator operating at a frequency of the order of 20 kHz, associated with a sub-projectile animated with a rotation speed of 15 t / s and a descent speed of 50 m / s. The angles of inclination of the directions d and D relative to the vertical will be 40 ° and 41 ° respectively.

The initiation of such a flash charge will generally be caused at a distance from the target of the order of 150 to 200m.

The directions d and D are not necessarily parallel. Practically these two directions are close and form an angle which is a function of the speed of descent of the projectile and the speed of the fragments (this angle is of the order of 1 °). The axis D of inclination of the flash charge will be slightly further from the vertical than the detection axis d. Indeed, the combination of the speed of the flakes with the speed of descent then makes it possible to ensure an arrival of the spray in the vicinity of the detected point.

Advantageously, the sub-projectile will be provided with a self-destruction by delay (pyrotechnic or electronic) or else with a rocket triggering the firing following the impact on the ground of the sub-projectile. We will then ensure in all cases the destruction of the sub-projectile which has not detected a target.

As a variant, it is of course possible to define a more rustic sub-projectile without an altimeter. The latter can be supplemented by transmitting with the laser beam an additional coding relating to the altitude measured by known ground means and not shown. The additional coding may be a fire authorization signal which will only be sent by the designator when the altitude of the sub-projectile is correct.

We can also provide a more or less large number of flash charges in the sub-projectile.

Regarding the cargo shell 2, it is possible to replace the chronometric rocket by a rocket equipped with a radio receiver and which will receive an order to eject the sub-projectile transmitted by a transmitter carried by the advanced observer.

As a variant, it is also possible to limit the exposure of the observer 9, to provide in the sub-projectile a radio transmitter intended to control the emission of the designation beam by the laser designator 10.

The duration of target designation can thus be greatly reduced, which limits the risks of detection by the target as well as of response. Optionally the designator can stay alone on the ground, pointed at the target that the operator has chosen.

FIG. 3 represents a variant of the sub-projectile 2a which contains a single charge 13 generating splinters whose direction of action D is radial with respect to the sub-projectile, therefore here substantially horizontal.

The detection direction d is also radial.

Again, the charge comprises an explosive 15 and a weakened coating 16. This sub-projectile is also provided with an altimeter 19.

This variant is more particularly intended for attacking light aircraft such as helicopters (on the ground or in flight) or for a lateral attack on light targets (vehicles, access doors to shelters).

It is possible to define a charge according to the invention which has at least two different operating modes (flash charge and anti-tank charge).

FIG. 4 thus represents a sub-projectile whose charge 20 comprises an explosive charge 21 placed in an envelope and on which a coating 22 is applied.

The charge 20 can be initiated as desired by a detonator primer 23 disposed axially or by the simultaneous initiation of one or more primers 24a, 24b, 24c ... (possibly of different powers) and arranged at a distance from the axis D of the charge (at least one primer 24).

When the charge is initiated by the primer 23, the detonation wave which propagates in the explosive charge is perfectly symmetrical around the axis D and it transforms the coating 22 into a nucleus animated at high speed (2000 to 2500 m / s). The charge then functions as an anti-tank charge (core-generating charge).

When the charge is initiated by the primers 24, the detonation waves generated cause the coating to break up into a multitude of fragments (such a charge concept is described in patent DE3625967). The load then functions as an anti light vehicle, anti personal or anti aircraft charge.

The load 20 therefore has two operating modes distinct both having the same direction of action D.

The direction of action D of the charge is inclined relative to the vertical XX 'and the sub-projectile is animated by a rotational movement of speed R around the axis XX'. This rotation is the residual rotation communicated to the sub-projectile by the cargo projectile 2. It can also be caused by a stabilizing parachute (as in patent FR2679643) or by another stabilization means (such as those described by EP587970 or US4858532) . The stabilization and / or braking means are not shown here. Reference may be made in particular to patents FR2590663, US4807533, EP587970, US4858532 and FR2679643 for details, in particular on the aerodynamic stabilization and braking means.

The sub-projectile according to the invention is equipped with extremely simple processing electronics.

As in the previous embodiment, the detector 12 detects the laser beam transmitted by the designator and which is reflected by the designated target. The beam is coded to allow resistance of the sub-projectile to countermeasures. The computer 18 causes the load 21 to fire when the detector 12 receives the coded signal reflected by the target.

As in the previous embodiment, the sub-projectile may be provided with an altimeter which blocks the initiation of the charge when the distance to the ground is too great.

The target designator will emit a laser beam which will carry (in addition to the protection against countermeasures coding) information relating to the type of operation desired for the load (core-generating charge or flash charge).

The detector 12 transmits the signal reflected by the target to the computer 18 which isolates (for example by filtering) the operating mode information carried by the signal and which causes, as appropriate, the initiation of the primer 23 or the primers 24 .

This embodiment allows the infantryman ensuring the target designation to choose the desired operating mode at the last moment while always using the same type of sub-projectile.

As a variant, provision may be made for a memory 25 connected to the computer and in which the desired operating mode for the charge will be introduced by the weapon system before firing or else transmitted by radio by the advanced observer at the time of the ejection of the sub-projectile (the memory is then connected to a radio receiver and an electronic decoder).

FIG. 5 represents a third embodiment of the invention in which the load 26 has two operating modes each having a different direction of action Da, Db.

The casing 27 of this charge contains an explosive 28 and it has undergone localized embrittlement at the level of a cylindrical sector 29 (see the section of the charge in FIG. 6).

It is closed at one of its ends by a coating of heavy material (iron, tantalum) intended to form a core.

A single primer 17 initiates this charge which simultaneously projects a nucleus in the direction of action Db and a burst of splinters in the direction Da.

The sub-projectile 2a is provided with two detectors 12a, 12b. The detector 12a has a detection direction (da) close to the direction of action Da, the detector 12b has a detection direction (db) close to the direction of action Db.

Here again, the target designator transmits a code to the sub-projectile with the laser beam which allows it to determine which mode of action to favor (flash charge or charge generating nucleus).

The computer then causes the load 26 to be fired when the detector associated with the direction of action which corresponds to the chosen operating mode receives the signal reflected by the target (and when the altimeter 19 authorizes the firing).

Thus, if it is a light target which is designated, the charge will be triggered only by the detection of the beam of designation by detector 12a. The effectiveness of the flash charge is then maximum with respect to the target.

If on the contrary the designated target is a tank, the charge will only be triggered by the detection of the designation beam by the detector 12b. The efficiency of the nucleus-generating charge is then maximum with respect to the target.

As a variant, it is possible to replace the coating 22 with a weakened coating which also generates splinters. The flash charge 26 then has two preferred anti-light vehicle action directions.

It is also possible, for example to improve the distribution of the flakes formed by the sector 29, to provide two different primers which can be initiated by the computer 18.

The primer 17 will be initiated for the firing of the core-generating charge, and another primer 30, arranged in a median plane of the charge and opposite the sector 29, will be initiated for the firing of the flash charge.

FIG. 7 shows a sub-projectile 2a which is dispersed in a known manner over a terrain area by a vector (not shown) such as an artillery cargo shell, a rocket, a mortar projectile, a bomb or a cruise missile.

The sub-projectile 2a is braked at the time of its ejection by the deployment of a parachute (not shown) which also gives it a substantially vertical orientation XX ′ with respect to the ground. The sub-projectile is driven by a rotational speed R of the order of 15 revolutions / second around this axis XX '.

The sub-projectile 2a comprises an explosive charge 31 generating a nucleus. Such a charge comprises, in a known manner, an explosive charge 32 placed in an envelope and to which a coating 33 is applied.

In such a charge, the initiation of the explosive charge 32 by a primer 34 causes the deformation of the coating 33 which turns into a projectile (or core) animated by a high speed (of the order of 2000 m / s).

Such a charge is intended to attack tanks, the aerodynamic stability of the nucleus and its precision allow it to be fired at distances from the target of the order of 200m.

A sub-projectile ejected by a cargo shell and provided with a nucleus-generating charge is known in particular from patents FR2590663, US4807533, EP587970, US4858532 and FR2679643, which may be referred to for details, in particular on the means of aerodynamic stabilization and braking.

As in the embodiment described with reference to FIG. 4, the direction of action D of the charge is inclined relative to the vertical XX 'and the sub-projectile 2a is driven by a rotational movement of speed R around of axis XX '.

Again, the sub-projectile is provided with a rocket which includes a directional detector 12 of laser radiation (such as a photodiode), which has an observation direction (d) close to the direction of action (D) of the charge. 31.

The rocket also includes a computer 18 to which the detector 12 is connected and which controls the initiation of the primer 34.

Due to the rotation of the sub-projectile during its descent, the direction of observation d (as well as the direction of action D) sweep the ground according to spiral curves.

The detector 12 is intended to receive the radiation coming from a laser designator (not shown) placed on the ground, radiation reflected by a target.

The designator is implemented by an advanced observer who is at a distance of the intended target of the order of 1 to 2 km.

When the detector 12 receives the radiation reflected by the target, it causes the initiation of the charge 31 which will have maximum efficiency due to the orientation of its direction of action D towards the target.

The laser beam transmitted by the designator will again be preferably coded to allow resistance of the sub-projectile to countermeasures. The computer 18 does will cause the charge 31 to fire only when the detector 12 receives the coded signal reflected by the target.

Here again, it is advantageously possible to provide the sub-projectile with an altimeter which blocks the initiation of the charge when the distance to the ground is too great.

It is thus seen that thanks to the invention, it is possible to attack targets when stationary or camouflaged. It is also possible to avoid engaging targets that are already out of state.

The invention also gives great operational flexibility.

Indeed, the infantryman who manipulates the designator can choose (depending on operational needs) to designate a target which is not an armored vehicle and which it would not be possible to engage with known autonomous sub-projectiles equipped with tank detectors.

The various embodiments described above were in an application to one or more sub-projectiles dispersed above the objective by a cargo shell. These sub-projectiles could obviously be dispersed by an artillery rocket, an airborne bomb or even a cruise missile.

It is also possible to define artillery or mortar projectiles, of general design similar to that of the sub-projectiles described in particular with reference to FIGS. 2, 3 and 5, provided that these projectiles are provided with means enabling them to adopt a substantially vertical attitude above the lens.

It will suffice for this to add aerodynamic braking means whose operation will be controlled by the chronometric rocket of the projectile.

It is also possible to define projectiles generally conforming to those described above but animated by a trajectory in which the axis XX 'is substantially horizontal above the objective. The operating mode is then the same as that previously described, the rotation of the projectile allows the terrain to be scanned by the detection direction d (the scanning is then carried out in bands parallel rather than spiral).

Such projectiles could be feathered artillery shells or projectiles launched by a tank cannon or by a light rocket launcher or even sub-projectiles dispersed over an area of land by cruise missiles.

Claims (11)

1. A projectile incorporating at least one splinter-generating and/or explosively-formed charge (13, 13a, 13b, 20, 26, 31) triggered by a fuse, said charge having at least one direction of action (D) and said fuse incorporating at least one detector (12) having a detection direction (d) whose orientation is similar to the direction of action (D) of the charge, said projectile being intended to be made to spin thereby allowing an area of ground to be scanned by the directions of detection and action, characterised in that the detector (12) is sensitive to laser radiation reflected by a target and coming from a targeter placed on the ground, said detection of laser radiation reflected by a target causing the charge (13, 13a, 13b, 20, 31 to ignite.
2. A projectile according to Claim 1, characterised in that the fuse incorporates means (18) to decode a signal transmitted by the laser radiation reflected by the target.
3. A projectile according to one of Claims 1 or 2, characterised in that the projectile incorporates emission means able to control the start-up of a laser targeter (10) positioned in the field.
4. A projectile according to one of Claims 1 to 3, characterised in that the charge (13, 20, 26) incorporates at least two different operating modes able to be activated selectively by the fuse.
5. A projectile according to Claim 4, characterised in that the decoding means of the fuse determine the required operating mode according to the signal of the laser radiation reflected by the target.
6. A projectile according to one of Claims 1 to 3, characterised in that the charge incorporates at least two different directions of action (Da, Db) and at least two directions of detection (da, db) associated with the directions of action.
7. A projectile according to one of Claims 1 to 3, characterised in that the charge (31) is an explosively-formed charge.
8. A projectile according to one of Claims 1 to 7, characterised in that it is a sub-projectile scattered by a vector over an area of ground.
9. A projectile according to one of Claims 1 to 7, characterised in that it is a projectile having an curved trajectory such as an artillery projectile or mortar projectile.
10. A projectile according to one of Claims 1 to 7, characterised in that it is a projectile released by an aircraft and with a free fall trajectory or gliding trajectory such as a bomb.
11. A projectile according to one of Claims 1 to 7, characterised in that it is a direct trajectory projectile fired from a tank, or light rocket-launcher.