Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F41—WEAPONS
  • F41G—WEAPON SIGHTS; AIMING
  • F41G3/00—Aiming or laying means
  • F41G3/14—Indirect aiming means
  • F41G3/142—Indirect aiming means based on observation of a first shoot; using a simulated shoot
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F42—AMMUNITION; BLASTING
  • F42B—EXPLOSIVE CHARGES, e.g. FOR BLASTING, FIREWORKS, AMMUNITION
  • F42B12/00—Projectiles, missiles or mines characterised by the warhead, the intended effect, or the material
  • F42B12/02—Projectiles, missiles or mines characterised by the warhead, the intended effect, or the material characterised by the warhead or the intended effect
  • F42B12/36—Projectiles, missiles or mines characterised by the warhead, the intended effect, or the material characterised by the warhead or the intended effect for dispensing materials; for producing chemical or physical reaction; for signalling ; for transmitting information
  • F42B12/38—Projectiles, missiles or mines characterised by the warhead, the intended effect, or the material characterised by the warhead or the intended effect for dispensing materials; for producing chemical or physical reaction; for signalling ; for transmitting information of tracer type
  • F42B12/387—Passive tracers, e.g. using a reflector mounted on the projectile

Definitions

• the present invention relates to weaponry and fire control, Moe speci icall , it relates to an ammunition profec ile and a fire control device for tracing the path of a
• the U.S. Patent No. 8,074,555 discloses a system for tracking the lateral drift and vertical drop of an
• a projectile is provided with an optical emitter, in the rear of the projectile housing, which produces optical strobe signals at predetermined times (Tl, T2, T3.,.) following firing of the projectile (at time TO) .
• An optical detector receives the optical signals and an image processor determines the lateral drift ⁇ i.e. XI, X2, X3.,.) and vertical drop (i.e. Tl, T2, ⁇ 3... of the projectile at the predetermined times (Tl, T2, T3. soil) following time TO.
• This system uses the real time data to correct for aiming errors due to gun jump, wind turbulence, altitude-dependent wind conditions, lot-to-lot ammunition irregularitie , bore sight misalignment and the like, for use when firing subsequent projectiles.
• This system is optimized to function with projectiles thet have adequate energy to power XSED's to emit strobe light and where the ballistic trajectory angles are significant (e.g., with mortars, artillery and 40mm systems) .
• the principal object of the present invention is to improve the precision and accuracy of weaponry systems fay taking into account all the factors that affect the actual ballistic flight of a projectile.
• an otherwise conventional ammunition projectile with a coating of luorescent dye material, on or near its rear surface, whereby the dye re-emits radiation in response to excitation by laser light.
• the fluorescent; dye optimized to luminance in response to laser radiation, exploits * natural phenomenon known as *laser-nduced-fluorescence.
• the dye is coated on an exernal rear surface of the projectile. She coating is preferably covered by a transparent shield or coating and, for example, it may be disposed on the inside surface of a transparent window on the rear of the projectile.
• the present invention also provides a system for correcting the aim of a weapon that is operative to launch such a projectile on a ballistic path toward a target.
• the aim- correcting system preferably includes the following
• a source of short (strobe) radiation pulses directed toward the ballistic path of the projectile for excitation of the fluorescent dye material on the projectile, such pulses being emitted at
• ⁇ 4 ⁇ ft computer coupled to the processor, for calculating * lateral correction and a vertical correction in the aim of the weapon;
• this aim-correcting device the aim of the weapon may be adjusted after the launch of one projectile to
• either the signal processor or the computer calculates the lateral drift and the vertical drop of the projectile at the predetermined times.
• the radiation source is laser source adapted to be a xed to the weapon so that the cone of illumination of the laser source intersects with the ballistic path of the projectile and excites the photo-luminescent materia ,
• the radiation detector is a digital camera for producing an image of the ballistic path of the projectile.
• the requency of the excitation radiation may be in one of the W r visual and IR spectral bands.
• Both the laser source and radiation detector may utilise narrow pass filters that provide for stealth in
• the radiation source preferably includes a narrow band-pass filter for selectively passing a narrow spectrum of laser light to the projectile to excite the fluorescent dye.
• the radiation detecting device preferably also includes a narrow band pass filter allowing only the re-emitted light from the fluorescent dye to pass to the detector, thereby minimising the data processing required of the detector outpu .
• the output device of the system may be a display for the operator who manually adjusts the aim in the weapon's bore sight ox it may automatically adjust the aim of the weapon, for example by passing the projectile drift and drop data to the fire control device of the weapon.
• Fig. 1 is a time diagram of laser induced fluorescence showing the delay in response to excitation.
• Fig. 2 is a representational diagram showing an ammunition projectile having a fluorescent dye at its rear sur ac .
• Fig. 3 is a diagram showing a weapon and the trajectory of a projectile fired from a weapon.
• Fig. 4 is * diagram showing a cone of illumination of strobe light emitted by a laser source tha intersects the ballistic flight path of a projectile fired front a weapon. The laser aim is slightly depressed from the bore sight for optimized intersection with the projectile's trajectory within the dispersion of the light cone *
• Fig. 5 is a diagram showing an optical detector which receives a light emission from a laser-illuminated
• Fig. 6 is a perspective view of a weapon having a laser source to illuminate a projectile in flight.
• Fig. 7 is a representational diagram showing an error imparted by a fire control device which uses ballistic tables and metrological sensors to calculate a predicted hit point ⁇ gunner aiming point) .
• Fig. 8 is a representational diagram showing how the system of the present invention identi ies the X and ? location of the detected fluorescent dye strobe signal against the sky or backdrop *
• Fig. 9 is a representational diagram showing how the system of the present invention uses the laser-induced and emitted strobe signal to correct for the actual dri t in the azimuth and inaccuracy in the ballistic fall of fired projectile (the view from fire control device at gunner's position) .
• Fig. 10 is a representational diagram shoving hew the system of the present invention is used, post firing, to shift fields of view. The system measures the angular changes of the platform or camera at the same moment that the tracer' s strobe signal is detected.
• Fig. 11 is a representational diagram showing how the fire control cooputer calculates a new fire control solution a ter measuring actual drif and drop of an observed
• Fig * 12 is a block diagram of the system according to the present invention which uses an algorithm that computes a solution for bore sight adjustment and/or automatically adjusts the aim point of * subsequently fired projectiles.
• the invention provides for a method and arrangement to collect optical location signals emitted by a projectile in flight fired from a weapon while simultaneously recording movement and/or acceleration. These optical signals are transmitted from a projectile in flight in either the visual, ultraviolet and infra-red spectrum.
• the signals are re-emitted from the projectile at predetermined times (Tlss, T2s, T3s, etc.) following the time of firing (TO).
• An optical detector incorporated into the weapon launcher or on an associated platform detects the angular geometry (pro ectile location in the sky) of the radiation re- emi ed by the photo-luminescent material on the projectile s well as the duration (time length) of this re-emitted s robe in its field of view.
• Fig. 1 is a time diagram illustrating the time delay of fluorescence in response to excitation by laser light. As may be seen, there is a delay of about 3 milliseconds between excitation and response, Th s period of delay is designated hereinafter by the letter
• Fig. 2 s ows an ammunition pro ectile 10 having a
• fluorescent dye preferably has a transparent or translucent coating to protect against damage or it is covered by a plastic shield or the like attached to the rear of the projectil .
• Th system has the capability to detect the laser- nduced fluorescence ("LXF") of a
• the system can utilize phosphor thermometry * By measuring this re-emitted light duration (*> the system can use temperature differences observed on projectiles in flight to farther differentiate between and among the locations of multiple projectiles when the rate of fire is such that multiple projectiles are in flight at the same time.
• Fig. 3 shows a weapon 12 capable of firing projectiles in the direction of a target 14» The projectiles impact in the region of the target in a
• Fig. 4 shows a laser scarce 18 mounted on the barrel of the weapon emitting pulses (strobes) of light in a cone of illumination 20 that intersects the projectile 10.
• Fig. 5 shows light 22 re-emitted by the fluorescent dye 11 on the projectile , reaching an optical detector 24 on or near the weapon 12.
• the laser strobe emits light at precise time intervals after launch or cartridge setback.
• the weapon fire control system compares the actual flight position at these precise post-firing intervals to the location that is forecasted by the original solution algorithm.
• the delta" positions are recorded (stored/registered) and the fire control provides a gunner with new "corrected” aim points using the
• the optical signals emitted by the fluorescent dye material on the projectile are collected by an optical detector f such as an IR camera, co-located with the weapon.
• the image is digitally processed and X and Y coordinates of the projectile's strobe signal are identified by collection at the predetermined time intervals.
• the computer associated with the system uses an algorithm to identify a precise aim point solution using the observed trajectory of previous shots, thereby re-measuring and re-calibrating the d stance and relative target elevation for subsequent firing of the weapon.
• Optical emissions include light in the ultraviolet, infra red and visual wavelengths.
• the weapon's fire control unit has the capability to emit a cone of light (modulated to strobe at a set time) that intersects with the ballistic path of the projectile, normally, the laser emission will be aligned vertically.
• the laser's horizontal alignment will drop slightly at an inclination so the top edge of the laser light illumination cone is aligned horizontally with the cantarline of the barrel. This geometry allows the laser light cone to cover the entire ballistic drop of the projectile.
• the laser emitter 18 transmits a short, intense light strobe signal at predetermined times a ter set back during the flight path of the projectile. This occurs at l » (time of emission + s) , T2 ** (time of emission ⁇ x) , S3 « (time of emission + *) , Tn » (time of emission + «) where s is the time delay in milliseconds, Using this technique it is possible to select dye combinations where the laser strobe transmits strobe signals at a given frequency and the dye's optical response differs in its response
• Projectile flight geometry provides for reflection of light rearward to the gunner' s position at pre-set intervals though the entire flight path *
• the fire control device associated with the weapon optically identifies the position ⁇ T1 » position xl,yl, T2 ⁇ osi o x2,y2, T3 » position x3, 3,...Tn « position xn, yn> of the projectile at set intervals.
• the invention provides for a system to collect optical location signals from a projectile in flight which are excited by an optical light source (visual, ultraviolet and in ra-red) ,
• the fire control uses observed time-location and angular observation data to compute an improved ballistic solution.
• the system allows the fire control computers to readily observe and calculate ire control solutions that reduce or eliminate (!) occasion- o ⁇ occasion errors, (2) ammunition lot-to-lot errors, and (3) bore sight misalignment.
• Fire control computers can readily adjust aim points using » «n»oxa to measure air temperature, pressur , firing geometry and standard mussle velocities; howeve , practical considerations still limit the accuracy of calculated solutions .
• Lot- o-Lot ammunition variations along with occasion - o-occasion errors still result In limitations In the accuracy of fire control solutions. Those errors also include those errors that result from varying
• Some ire control systems allow users to input manual dri and elevation offsets, but these manual offsets are generally linear> Hence, the current generation fire control devices continue to provide inaccurate aim points due to the fact that they only calculate a limited number of inputs while many "unsolved* sources of errors are not factored In.
• Unsolved errors include (a) bore sight misalignmen , (b) lot-to-lot errors, ⁇ c) occasion-to-occasion errors and id) limitations in existing wind sensor technology. All unsolved ⁇ xxoxs degrade the accuracy and precision of weapon fire control solutions, as illustrated in Fig. 7
• the projectile's stimulated dye response occurs at discrete intervals (at ⁇ 1+», T2+z, 3+*,...Tn+*., where a is the response delay) that are observed by ire control devices equipped with optical sensors.
• the dye's strobe response to laser illumination identi ies the position of the
• the system according to the invention optically collect the strobe light emissions at re eermined poet fixing (post set-back or launch) time ndows.
• he projectile's fluorescent dye emits light strobe o es that are collected by the optical detector 24 (e.g. a camera) and digitally recorded.
• the optical detector 24 e.g. a camera
• the device At each pre-set time window the device also records changes in the X and Y orientation of dye emission.
• the system's image processing software measures or signal processing algorithms calculate the X and ⁇ location of the optical strobe emission at the pre-set time window.
• the system' s signal processor identifies the X, v location of the detected dye strobe signal against the sky or backdrop as shown in Figs. 9 and 10, thereby determining the actual drift and drop of the projectile 10 as seen from the gunner's position.
• the measurement of observed pro ectile drift and vertical drop are obtained by an image processor to isolate the strobe tracer's positio . Simultaneously, angular changes in the detector are measured.
• the image processor search and detects the strobe images at pre-set intervals a ter firing. Alternatively, the signal processor detects the signal at pre-set intervals a ter firing.
• Post firing resonance can create shifting fields of view.
• the system measures the angular changes of the platform or optical detector ⁇ camera ⁇ at the same moment that the projectile's strobe signal is recorded.
• a weapon's fire control system can utilize two methods to provide improved fire control solution .
• the fire control system can (1) reset subsequent fixe control solutions to se actual observed drift and drop, or ⁇ 2) establish a correction factor which modifies the calculated fire control solution.
• ⁇ 2 a correction factor which modifies the calculated fire control solution.
• Fire control computer calculates a new ire control
• FIG. 11 shows projectile strobe signals from the next subsequently ired projectile as viewed om a gunner's position with the hit point corresponding to aim point.
• the system and methodology according to the invention allow fire control devices to adjust the aim point (in azimuth and elevation) so that subsequently ired cartridges hit the Intended target by using actual observed azimuth dri t and vertical drop.
• the fire control computer calculates improved solutions for new engagements.
• the fire control may use commonly known mathematical algorithms to further improve the precision of the corrected aim point as it repeatedly measures the actual position of cartridge drift and azimuth with a larger sample else.
• an algorithm computes a solution for bore sight adjustment and/or automatically adjusts the aim point of subsequently fired projectiles.
• the algorithm develops fire control eolations ⁇ aim points) using actual, observe azimuth and elevation.
• Figure 12 shows a system 30 according to the invention fox a weapon 12 comprising an emitter 33, one or more sensors 34, an optical detector (e.g. camera) 36, a signal
• processor 38 and a computer 40 operating with software 42 *
• the sensors 34 are used to identify various parameters of the weapon 12. Such sensors can be of various types, for example, position sensors, sensors for gun elevation, optical sensors and the like.
• the emitter 33 is a high- powered laser which is triggered by the computer 40 to produce a strobe of light.
• the optical detector 40 can be any type of image capturing device, for example a video camera, infrared camera or the like. It produces electronic signals representing the images and passes them to a signal processor 42.
• the processor 42 determines X,Y location and as well as the time duration of each received response from a projectile in flight. This information is passed to the computer 40 for calculating a lateral correction and a vertical correction in the aim of the weapon 12.
• the fire control device measures the angular position of the weapon 12 when the weapon fires a projectile aimed at a target.
• This angular position information includes a radial azimuth/elevation barrel centerline and elevation of barrel/ ire control elevation,
• the angular position is measured by the sensors 34 and this information is also passed to the computer 40.
• the computer determines the drift and drop of the fired projectile end passes this data to the fire control device for adjusting the aim point of for the next projectile to ibe " ' fired *
• the tine delay (a) of the re-emitted signal allows the computer 36 to disregard reflections received by the detector 40 front stray objects.
• the time duration of the re-emitted signal allows the computer to distinguish between multiple projectiles in flight which have been rapidly fired successively by the weapon 12. Closer (and therefore hotter) projectiles will have shorter duration re-emissions that the pro ectiles that are farther away (and therefore cooler) .

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• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Aiming, Guidance, Guns With A Light Source, Armor, Camouflage, And Targets (AREA)
• Optical Radar Systems And Details Thereof (AREA)

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• 2014
  • 2014-03-20 EP EP14797122.0A patent/EP2976593A4/de not_active Withdrawn

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