Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F42—AMMUNITION; BLASTING
  • F42C—AMMUNITION FUZES; ARMING OR SAFETY MEANS THEREFOR
  • F42C13/00—Proximity fuzes; Fuzes for remote detonation
  • F42C13/02—Proximity fuzes; Fuzes for remote detonation operated by intensity of light or similar radiation

Definitions

• the present invention relates to a method and a system for activating the charge of a munition. It also relates to a munition equipped with a high precision activation device. Finally, it concerns a system for neutralizing a target. The invention applies in particular to hit hidden targets where there is not necessarily a direct impact with these targets.
• the guided or unguided munitions fired remotely by any device can have a direct kinetic effect on the objective. This effect may be lethal or non-lethal depending on the shooting conditions and the nature of the projectile, such as metal or rubber.
• These ammunition can also have a reinforced or indirect effect by equipping the munition with a secondary device such as:
• a pyrotechnic charge which is hollow, explosive or dispersed with sub-projectiles, liquid or gas, for example a tear gas;
• indirect effects applications include, for example:
• An object of the invention is in particular to overcome the aforementioned drawbacks, in particular by allowing a sufficiently precise trigger position without implementation complexity.
• the subject of the invention is a method of activating a munition near a target using a laser beam that illuminates an object located near the target, firing the charge of the ammunition being activated from the detection by the munition of the laser spot backscattered by the object.
• the firing is activated a time ⁇ t1 after the detection time t 0 of the laser spot, possibly the time ⁇ t1 is substantially zero.
• the aiming direction of the munition preferably passes close to the object.
• the object can be an obstacle behind which hides the target.
• the head of the ammunition is equipped with at least one optical detector.
• the invention also relates to a system for activating a munition near a target, the system comprising at least: a laser source creating a beam that illuminates an object located near the target;
• an optical device equipping the munition to detect the laser spot backscattered by the object; a control block equipping the munition creating the activation signal from a detection signal received by the optical device.
• the laser source being coupled to the gun firing the ammunition, the aiming direction of the barrel passes close to the object.
• the control block transmits the firing signal a time ⁇ t1, possibly zero, after the instant t 0 for receiving the detection signal.
• the optical device comprises, for example optical detectors placed at the periphery of the head of the munition.
• the invention also relates to a munition comprising an activation device composed of at least one optical detector and a control block, the optical detector being intended to detect a signal produced by an object located near a target.
• the detectors are disposed at the periphery of the head of the munition.
• the optical detectors are for example located on the periphery of the same cross section.
• the optical opening of the detectors is elliptical, the major axis of the opening being oriented perpendicular to the axis of symmetry of the munition.
• the optical axis of a detector forms for example with the axis of the munition an angle ⁇ substantially equal to 60 °.
• the optical detector 43 and the control block are made for example in the form of a kit adaptable to ammunition existing instead of a control device originally equipping the munition.
• the invention finally relates to a system for neutralizing a target comprising at least one munition as defined above and a laser source for illuminating an object located near the target, the firing of the charge of the munition being activated by the control block from the detection of the laser spot backscattered by the object.
• FIG. 1 an exemplary implementation of the activation of the charge of a munition according to the prior art
• FIG. 2 an illustration of the method and of a system according to the invention for activating an ammunition
• FIG. 3 an illustration of the trajectory of a munition in the vicinity of an object located near a target
• FIG. 4 an illustration of the head of a munition equipped with an activation device according to the invention.
• FIG. 1 illustrates an exemplary implementation of a system for activating the charge of a munition according to the prior art.
• a munition 1 is fired at a distance by a gun 2.
• the purpose of the mission is to neutralize a target X hidden behind an obstacle 3, for example a wall.
• the gun 2 is located about one kilometer from the wall 3. Knowing the speed of the ammunition 1, it is theoretically possible to deduce at a time ⁇ t after firing the distance traveled by the ammunition. On the other hand, knowing the distance D to which the charge of the munition must explode, one deduces the corresponding delay ⁇ t 0 to apply to the firing.
• the speed of the ammunition can not, for example, be better than 1%.
• FIG. 2 illustrates a method and also a system for activating the charge of a munition 23 according to the invention.
• a laser beam 21 is used. This laser beam 21 illuminates not the target X, because it is hidden, but an object located in its vicinity and chosen by the shooter.
• the object may be the obstacle that hides the target, for example a wall or wall 3 behind which is hidden the target X.
• the chosen object could also be for example the frame of a window or a window. opening of a building.
• the aiming direction 22 of the ammunition 23 is chosen by the shooter. It passes close to the object 3. It aims for example the center of a window or a place located about a meter above a wall.
• the laser beam 21 is created by a laser source, for example coupled to the barrel 2.
• the munition 23 is equipped with a directional optical detector intended to detect the laser spot 24 backscattered by the neighboring object of the target X, in this case the wall 3 in the example of Figure 2, according to a predefined geometric configuration.
• a firing delay ⁇ t1 is engaged. At the end of this time ⁇ t1 the munition is fired and explodes 25.
• the time ⁇ t1 is very short but sufficient for the ammunition 23 to exceed the obstacle 3 and explode opposite the target X, close to the latter.
• the uncertainty of the distance traveled since the detection of the laser spot on the obstacle is extremely small because the distance in play predefined is no longer of the order of a kilometer but of the order of ten meters, even a few meters.
• an inaccuracy of 1% leads to an inaccuracy of distance traveled only 0.1 meters.
• the optical detector of the munition detects the laser spot 24 and with the preset delay ⁇ t1, the charge of the ammunition is fired. If necessary ⁇ t1 can be taken equal to 0. In this case the delay created is the natural firing delay which is sufficient for the charge to explode a few meters after time t 0 .
• the ammunition has an optical device. It also comprises a control block for processing the detection signals received by the optical device, creating the possible delay ⁇ t1 and creating the activation signal for firing the charge of the munition from a received detection signal .
• the obstacle 3 is rough, that is to say that it comprises, in particular, surface irregularities of dimensions greater than the wavelength of the laser, and that it is not totally absorbent; which causes a backscattering laser signal 24 little directive and sufficient intensity to allow detection a few meters. These conditions are often encountered in reality and are therefore not very restrictive.
• FIG. 3 illustrates the trajectory of the munition 23, assumed to be coincidental with the firing axis 22, and the optical axis 26 of a detector equipping the munition near the obstacle 3, for example a wall.
• the two axes 22, 26 form a substantially constant angle ⁇ .
• M 0 represents the first point of the trajectory 22 where the detector detects the laser spot 24 on the obstacle, corresponding to the instant t 0 above.
• the spot is located at a point I on the surface of the obstacle.
• the point H represents the projection of the point I on the trajectory 22 of the munition and the point M F the desired point of ignition on this same trajectory.
• the distance M 0 H depends on the height of overflight of the munition with respect to the obstacle, the point illuminated on the obstacle and the angle ⁇ of orientation of the detector, assumed to be perfectly known. It follows that:
• the uncertainty ⁇ (IH) is notably a function of the pointing errors of the laser sighting axis and the firing axis, the characteristics of the laser spot on the obstacle 3 and the characteristics of the detector embedded in the munition 23
• the error ⁇ (IH) may be of the order of 2 meters.
• angle ⁇ is important. This angle ⁇ depends in fact on the arrangement of the detector in the munition 23 and more particularly on the inclination of its optical axis with respect to the axis of the munition. If ⁇ is weak, the term 1 / tg ⁇ becomes very large and tends to infinity when ⁇ tends to 0.
• the backscattered laser signal is weaker and more dependent on the surface state of the obstacle
• FIG. 4 illustrates the head of a munition according to the invention, equipped with a high precision activation device.
• a munition detonates at a location that can be precisely defined, including a precision as previously expressed.
• the activation device comprises in particular optical detectors and an associated electronic processing and control unit.
• the munition is composed of a body, not shown, for example comprising the pyrotechnic charge and the head 41.
• the head has a substantially conical appearance around the axis of symmetry 42 of the munition which merges with the axis of its axis. trajectory during the shooting phase.
• the head 41 of the munition comprises an optical device intended in particular to detect the laser spot reflected by an obstacle 3.
• This optical device comprises optical detectors 43 placed at the periphery of the head 41 of the ammunition.
• the optical detectors are for example infrared detectors.
• the optical axis 26 of a detector 43 forms the angle ⁇ with the axis 42 of the munition. According to what has been specified above, the angle ⁇ is for example of the order of 60 °.
• the field of optics is a parameter to adjust according to the characteristics of the mission.
• the optical detectors are for example disposed on the same cross section of the head and distributed around the perimeter of this section.
• detectors can be distributed regularly and in sufficient number to cover the entire space, and more particularly to take into account the roll of the ammunition. Indeed, the rolling position of the ammunition is generally not known. It is then necessary to use several detectors distributed around the perimeter of the head, preferably on the same cross section. These detectors may be distributed regularly and symmetrically with respect to the axis 42 of the munition. In order to limit the number of detectors, especially for cost reasons, it is advantageous to use optics with asymmetrical aperture, for example having a large field in the plane perpendicular to FIG. 4 passing through the optical axis 26. The opening of a detector is then elliptical, the major axis being oriented perpendicular to the axis of symmetry 42 of the munition.
• the device with several detectors is also useful to reduce uncertainty in the instant of detection.
• this rotation speed usually reaches values greater than 1000 revolutions per second. Under these conditions, two detectors can suffice.
• the head furthermore comprises an electronic block intended in particular to process the optical signals supplied by the detectors and then to create the activation signal for firing the charge of the munition, possibly with the delay ⁇ t1.
• the electronic block is connected to the optical detectors.
• An ammunition whose head is illustrated in FIG. 3 can be used in a system substantially different from that of FIG. 2 provided that it can detect a signal, for example a laser spot, located near a target. Such an ammunition associated with a laser source composes an effective neutralization system of a target.
• the optical detector 43 and the control block are for example made for example in the form of a kit adaptable to existing ammunition instead of a control device originally equipping the ammunition, for example to the place of a chronometric rocket or an impact detector.
• the old control device is then removed, unscrewed for example, and replaced by the adaptable kit.

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• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Aiming, Guidance, Guns With A Light Source, Armor, Camouflage, And Targets (AREA)

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• 2004
  • 2004-07-23 FR FR0408188A patent/FR2873438B1/fr active Active
• 2005
  • 2005-07-22 WO PCT/EP2005/053582 patent/WO2006010741A1/fr active Application Filing
  • 2005-07-22 US US11/572,565 patent/US8146499B2/en active Active
  • 2005-07-22 EP EP05774192A patent/EP1782018A1/de not_active Ceased
• 2007
  • 2007-01-22 IL IL180868A patent/IL180868A0/en active IP Right Grant

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