Method and apparatus for improving the aim of a weapon station, firing a point-detonating or an air-burst projectile

Abstract

The method and apparatus for a remote weapon station or incorporated into manually-aimed weapons. The methodology requires use of a muzzle velocity sensor that refines the aiming of the second and subsequent fires or volleys fired from weapon systems. When firing the first volley a weapon uses an estimated velocity and, at firing, the muzzle velocity of a projectile is measured. When firing the second volley a weapon's fire control calculates an aiming point using the measured velocity of the first volley.

Claims

1. A method of aiming a weapon station when firing projectiles toward a target, said weapon station comprising a weapon barrel with a muzzle, a mechanical support for controlling the elevation and traverse of the barrel, sensing means for determining the muzzle velocity (MV) of a projectile when exiting the barrel and a fire control processor for calculating barrel elevation for ballistic flight of the projectile toward a desired target in dependence upon certain input parameters, said method comprising the steps of: (a) inputting to the processor, initially, an estimated default muzzle velocity for a given ammunition can of a selected type of ammunition projectile; (b) inputting to the processor a range to the target; (c) adjusting the barrel elevation based on the default MV and the range to the target for the ballistic flight toward the target of a projectile from said given ammunition can of projectiles; (d) firing at least one projectile from said given ammunition can of projectiles toward the target; (e) determining an actual MV for said at least one projectile; (f) adjusting the barrel elevation based on said actual measured muzzle velocity and said range to the target; (g) firing at least one additional projectile from said given ammunition can of projectiles toward the target.

2. The method defined in claim 1, further comprising the step of repeating steps (e) through (g) for at least one further projectile selected from said given ammunition can of projectiles.

3. The method defined in claim 1, further comprising the steps (a) through (g) for cartridges from another ammunition can of projectiles.

4. The method defined in claim 1, wherein said at least one projectile is a point-detonating projectile.

5. The method defined in claim 1, wherein said at least one projectile is a programmable air-burst projectile.

6. The method in claim 5, wherein the programmable projectile has an optical sensor or modem for receiving optical programming signals emitted from a transmitter electronically connected to, and physically adjacent to, the weapon station, and wherein said method further comprises the steps of generating and transmitting said programming signals to said programmable projectile for adjusting a time of projectile detonation after firing.

7. The method in claim 5, wherein the programmable projectile has an RF antenna that receives RF programming signals emitted from a transmitter electronically connected to, and physically adjacent to, the weapon station, and wherein said method further comprises the steps of generating and transmitting said programming signals to said programmable projectile for adjusting a time of projectile detonation after firing.

8. The method in claim 5, wherein the programmable projectile has a magnetic sensor that receives modulated electro-magnetic programming signals emitted from a magnetic modulating programmer electronically connected to, and physically adjacent to, the weapon station, and wherein said method further comprises the steps of generating and transmitting said programming signals to said programmable projectile for adjusting a time of projectile detonation after firing.

9. The method in claim 5, wherein the programmable projectile has an antenna that receives microwave band electro-magnetic programming signals emitted from a focused microwave programmer electronically connected to, and physically adjacent to, the weapon station, and wherein said method further comprises the steps of generating and transmitting said programming signals to said programmable projectile for adjusting a time of projectile detonation after firing.

10. The method of claim 1, wherein said given ammunition can of projectiles include a linked chain of projectiles.

11. A weapon station including a weapon with a barrel having a muzzle for firing ammunition projectiles from an ammunition can of projectiles and comprising: a mechanical support configured to elevate and averse said weapon barrel; a sensing device, disposed in or adjacent said barrel, for measuring an exit muzzle velocity (MV) of a fired ammunition projectile; a fire control unit coupled to the mechanical support and to the MV sensing device, said fire control unit having a processor for calculating the barrel elevation and traverse in dependence upon at least one input parameter including a default MV for a given ammunition can of projectiles and a measured MV of projectiles that are fired from said weapon.

12. The weapon station of claim 11, wherein said ammunition can of projectiles includes a linked chain of projectiles.

13. The weapon station defined in claim 11, wherein said fire control processor is operative to calculate a new setting for the weapon barrel elevation after the MV of an initially fired projectile is measured, thereby to improve the aiming fidelity of the weapon for second and subsequent shots.

14. The weapon station defined in claim 11, wherein said fire control processor is further operative to calculate a new setting of the weapon barrel elevation after the MV of each further projectile volley is measured, thereby to produce finer adjustments in the barrel elevation and thus continuously improve aiming precision for subsequent volleys.

15. The weapon station defined in claim 11, wherein said ammunition projectiles are conventional point-detonating projectiles.

16. The weapon station defined in claim 11, wherein said ammunition projectiles are programmable air-burst projectiles.

17. The weapon station defined in claim 11, wherein said ammunition projectiles are programmable air-burst projectiles; wherein said fire control processor is operative to calculate a new setting of the weapon barrel elevation after the MV of each projectile volley is measured; and wherein the fire control processor is operative to record a histogram of projectile MV's, and to use said histogram to produce continuously improving elevation precision for subsequent volleys.

18. The weapon station defined in claim 11, wherein said ammunition projectiles are programmable air-burst projectiles; said weapon station comprising means for generating and transmitting a programming signal to fired projectiles in dependence upon their measured MV, thereby to improve the time-of-flight or burst accuracy of second and subsequent projectile volleys.

19. The weapon station defined in claim 11, wherein said ammunition projectiles are programmable air-burst projectiles and wherein said fire control processor adjusts the weapon barrel elevation for a terrestrial target to detonate said projectiles in the range of 1-3 meters above said desired target.

20. An apparatus, including a weapon having a barrel with a muzzle capable of firing ammunition projectiles, said apparatus comprising: hand-held binoculars and a range finder for determining range to a target; a mechanical support for the weapon configured to allow elevation and traverse of the weapon barrel; a sensing device, disposed in or adjacent the weapon barrel, for measuring an exit muzzle velocity (MV) of a fired ammunition projectile; a fire control unit, electronically coupled to hand-held binoculars and range finder and to the MV sensing device, having a fire control processor calculating a barrel elevation in dependence a range to the target and a measured muzzle exit velocity (MV) of a projectile fired from the weapon.

21. Apparatus as defined in claim 20, wherein said fire control processor is operative to calculate a new setting of the barrel elevation after the MV of an initial projectile volley is measured, thereby to improve the aiming fidelity of the weapon.

22. Apparatus as defined in claim 20, wherein said fire control processor is further operative to calculate a new setting of the barrel elevation after the MV of each further projectile volley is measured, thereby to produce ever finer adjustments in the barrel elevation and thus continuously improve aiming precision for subsequent volleys.

23. Apparatus as defined in claim 20, wherein said ammunition projectiles are point-detonating projectiles.

24. Apparatus as defined in claim 20, wherein said ammunition projectiles are programmable air-burst projectiles.

25. Apparatus as defined in claim 20, the fire control unit controls electronically coupled hand-held binoculars and a range finder, wherein said ammunition projectiles are programmable air-burst projectiles; wherein said fire control processor is further operative to calculate a new setting of the weapon barrel elevation after the MV of each further projectile volley is measured and to record a histogram of projectile MV's, and wherein the fire control processor uses said recorded histogram to produce continuously improving elevation precision so that the emitted time of flight or burst or distance programming signal improves the burst accuracy of second and subsequent projectile volleys.

26. Apparatus as defined in claim 20, wherein said fire control processor adjusts the weapon barrel elevation for a terrestrial target to detonate in the range of 1-3 meters above said target.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1A depicts a system diagram and function sequence for a prior Art Kongsberg Remote Weapon Station (RWS).

(2) FIG. 1B depicts 40 mm terrestrial target ballistics at 1000 meters for the RWS shown in FIG. 1A.

(3) FIG. 1C depicts a detail of the 40 mm terrestrial target ballistics at 1000 meters shown in FIG. 1B.

(4) FIG. 1D depicts 40 mm drone (UAS) target ballistics at 1000 meters for the RWS shown in FIG. 1A.

(5) FIG. 1E depicts a detail of the 40 mm UAS target ballistics at 1000 meters shown in FIG. 1D.

(6) FIG. 1F depicts prior art 40 mm terminal ballistics using the methodology described in the U.S. Pat. No. 9,600,900.

(7) FIG. 1G is a graph of theoretical versus measured muzzle velocity and P(hit).

(8) FIG. 1H shows modeling results for 40 mm53 uncorrected volleys.

(9) FIG. 2A shows a US M151 Remote Weapon Station (RWS) with a muzzle velocity (MV) measurement device on a MK19 firing an ammunition projectile.

(10) FIG. 2B shows a US M151 RWS with an MV measurement device on a MK19 firing an optically programmed projectile.

(11) FIG. 2C shows a US M151 RWS with an MV measurement device on a MK19 firing an RF or extended range magnetically programmed projectile.

(12) FIG. 2D shows a US M151 RWS with an MV measurement device.

(13) FIG. 2E depicts 40 mm UAS target ballistics at 1000 meters for the US M151 RWS with an MV measurement device shown in FIG. 2D.

(14) FIG. 2F depicts the average miss distance resulting from a 40 mm (lot) muzzle velocity variation from a ballistic solution's theoretical solution.

(15) FIG. 3A is a system block diagram for a US M151 RWS, improved with the addition of a muzzle velocity measurement and an air-burst programmer.

(16) FIG. 3B is a system block diagram for a US M151 RWS, firing a second volley with an improved system function to measure muzzle velocity, adjusting elevation and firing a programmable air-burst projectile. The table in the top left corner of the figure depicts a method of computation used in the fire control ballistic computer and a resulting elevation solution.

(17) FIG. 3C is a system function sequence diagram for an exemplary initial commutation, based on an algorithm or table, identifying an elevation solution for a second volley with a re-adjusted elevation, where the weapon system previously measured the first volley muzzle velocity.

(18) FIG. 3D is a system function sequence diagram for a second volley elevation solver using a histogram of prior shots data, producing a revised solution for a second and subsequent volleys. The diagram depicts sequencing of volleys and fire control sub-routines where a first volley calculates a solution based on a default muzzle velocity and second and subsequent volleys use actual measured muzzle velocity.

(19) FIG. 4A depicts a manually-adjusted weapon, with a muzzle velocity sensor, a fire control and range finder incorporated into external binoculars.

(20) FIG. 4B depicts two views of an MK19 weapon from the gunner's perspective, showing a range output and an adjustment indicator.

(21) FIG. 4C is a system function sequence diagram showing an initial and subsequent elevation solutions.

(22) FIG. 4D depicts a manually-adjusted weapon, with a muzzle velocity sensor and a fire control device with a range finder incorporated into external binoculars. The weapon system is fitted with an optical programmer to set the detonation time of a programmable projectile.

(23) FIG. 4E depicts a manually-adjusted weapon, with a muzzle velocity sensor and a fire control device with range finder incorporated into external binoculars. The system is fitted with an RF or Extended Range Magnetic Induction programmer to set the detonation time of a programmable projectile.

(24) FIG. 4F depicts a manually-adjusted weapon, with a muzzle velocity sensor and a fire control device with range finder incorporated into external binoculars. The system is fitted with an Oerlikon AHEAD type of programmer to set the detonation time of a programmable projectile.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(25) The relevant prior art as well as the preferred embodiments of the present invention will now be described with reference to FIGS. 1A-4F of the drawings. Identical elements are designated with the same reference numerals.

Prior Art

(26) For context and for an understanding of the present state of the art, it is useful to examine the existing remote weapon station configurations to illuminate how lot-to-lot variation of mean muzzle velocity in 40 mm cartridges influences calculated aiming solutions. FIGS. 1A-1F depict benchmarks and performance characteristics delivered in existing systems.

(27) FIG. 1A includes diagrams similar to those in the U.S. Pat. No. 8,286,872 for a remote weapon station optimized to fire air-burst ammunition. FIG. 1B depicts a 40 mm AGL ballistic flight path when aimed to impact near a ground target at 1000 meters.

(28) Most fire control algorithms, presently in use, use encoded reference elevation tables and algorithms with an assumed standard muzzle velocity to calculate elevation. Unfortunately, the lot-to-lot variations of 40 mm53 ammunition often result in the remote weapon station's missing their targets at extended ranges. FIG. 1B shows both the ballistic flight 44mva of a cartridge fired with a 1 sigma muzzle velocity (lower muzzle velocity compared to the firing table algorithm) and the ballistic flight path 44mvb of a cartridge fired with a 1 sigma muzzle velocity (above the firing tables average muzzle velocity). FIG. 1C is an enlarged view of the terminal ballistics resulting from the varying muzzle velocities 44mv0, 44mva and 44mvb, depicting the detonation of a programmable 40 mm53 air-burst ammunition projectile when fired along the ballistic flight path.

(29) FIG. 1D depicts the ballistic path 44 of a 40 mm AGL projectile firing at a target at an elevation of 90 meters and, for a set time, the detonation locations 46mva, 46mv0 and 46mvb along the flight paths 44mva, 44mv0 and 44mvb, respectively, for ammunition without adjusted programmed time to detonation and without and second volley elevation adjustment. FIG. 1E illustrates the burst point variation transposed over a target UAV 42. FIG. 1F depicts the utility of adjusting the programmed flight time (to detonation) T2 in accordance with the method disclosed in the U.S. Pat. No. 9,600,900, and an automated elevation adjustment according to the present invention.

(30) FIG. 1G is a simple graph, produced from modeling, identifying the mean miss distance of 40 mm high velocity ammunition for known projectile mean lot variation. FIG. 1H is a table showing the calculated probability of the average and adjusted miss distance for a first volley, as the muzzle velocity of a lot varies from the mean.

(31) The purpose of the present invention is to improve a gunner's aiming for second and subsequent volleys. I may be incorporated into both remote weapon stations and manually-controlled weapon and fire control combinations.

(32) FIGS. 2A, 2B, 2C and 2D, with reference to corresponding FIGS. 3A, 3B, 3C and 3D, respectively, depict several embodiments 10 of the subject invention incorporated into a remote weapon station, with a muzzle velocity measurement device 52, that fires a projectile 60. The unfired projectiles are fitted in cartridges 66, that are stored in an ammunition can 68, in the rack of a Remote Weapon Station (FIG. 2A). These embodiments include a fire control computer 12, having a memory storage 12B and running a fire control algorithm 12D, mounted into a mechanical support 18 on a weapon. The muzzle velocity measurement device 52 feeds data to the memory storage 12B and the fire control algorithm 12D calculates the ballistic flight path. The system preferably incorporates a programmer 54 capable of programming ammunition projectiles 64 when they are fired from the weapon.

(33) FIG. 2C depicts an RF programmer 54B on the muzzle of the weapon that programs an RF programmable projectile 64B. After a first volley V1, the system automatically re-aims, the mounted weapon producing an improved aiming elevation.

(34) The embodiments of the invention shown in FIGS. 2A, 2B, 2C and 2D operate to fire a projectile 60, which may be conventional 62 or programmable 64. These embodiments include a muzzle velocity measurement device 52 that measures each projectile's muzzle velocity MV, stores this muzzle velocity in the memory 12B, and then employs the ballistic algorithm 12D to recalculate and reset the elevation 22B after firing. The second and subsequent volleys thus have an improved aim elevation, compared to the first volley.

(35) FIG. 2D depicts an in-bore programmed projectile 64D, with an in-bore muzzle velocity measurement and programmer 54D as provided for in the Oerlikon (AHEAD) patents referred to above, which are licensed to STK (Singapore) and to General Dynamics Ordnance and Tactical Systems (US).

(36) FIGS. 2E and 2F depict the expected improvement in firing with an unmanned system located at a range of 1000 meters and at an altitude of 90 meters. FIG. 2E depicts the projectile's improved ballistic path 44C, and the projectile's detonation at an adjusted time T2 in close proximity to the target 42. FIG. 2F depicts the forecasted improvement of a remote weapon station with the remote adjustment of the second volley, where the first volley V1 has a low probability of hit and the second volley V2 has an improved probability of hit P1. The initial aim point 12E for the initial firing test uses the assumed muzzle velocity for the lot of ammunition.

(37) FIG. 3A depicts a remote weapon station system with a muzzle velocity measurement device 52A, 52B, 52C and programmer 54. With reference to FIG. 3B, the remote weapon station firing a first engagement volley aims the weapon using a theoretical or default muzzle velocity 12C and may adjust the users aiming point 12F. As represented in FIG. 3C, a second volley is aimed using a ballistic solution algorithm 12D that runs, based on the measured muzzle velocity. FIG. 3C depicts the sequence of fire control sub-routines of a first, second and subsequent volley.

(38) FIG. 3A is an external view of improved remote weapon configuration according to the invention, with a muzzle velocity measurement device 52 mounted on a weapon's muzzle. FIG. 3B shows a system diagram for US M151 RWS Remote Weapon Station that includes a conventional muzzle velocity measurement device 52A, or a radar device 52B that may include a position sensor 52C, such as that disclosed in U.S. Pat. No. 8,074,555. This RWS system operates with a projectile programmer 54.

(39) The initial commutation in the system of FIG. 3B is based on an algorithm or table 12C, identifying an elevation solution 22C. The table (left top) identifies the theoretical elevation for a 40 mm AGL cartridge where the solution is derived from a firing table.

(40) FIG. 3C is a process flow diagram illustrating the remote weapon station's control sequencing when firing volleys V, with control sub-routines identified. The exit velocity of the first volley V1 is measured at 52 and a fire control computer 12B then calculates a fire control solution 12C based on an algorithm that uses a default muzzle velocity. When firing a second volley V2, an alternative fire control algorithm 12D re-adjusts the elevation 22B.

(41) FIG. 3D shows a system in which the muzzle velocity of an initial volley is measured at 52A and a fire control computer 12, using measured velocity V1, re-adjusts the weapon and mechanical support 18 to a second elevation solution. This system relies on a histogram of prior shot muzzle velocity data stored in the fire control memory.

(42) FIGS. 4A, 4B, 4C, 4D and 4E depict an alternative embodiment of the invention having a manually-elevated mounted weapon 18, with a display 08, connected to a fire control system 12D with a projectile velocity measurement sensor 52, where the system includes external range-finding binoculars with a data link 06A (either galvanic or wireless). This system may fire conventional cartridges 60 as depicted in FIG. 4A or programmable cartridges 64A, 64B and 64D as depicted in FIGS. 4D, 4E and 4F. FIG. 4F, similar to FIG. 2D, depicts the sequencing of firing the manually-elevated weapon with an in-bore muzzle velocity measurement and programmer 54D.

(43) Range-finding binoculars with a data link output (for example, Bluetooth wireless or an RS232 cable connection) that are suitable for use with this system are available commercially. Examples are:

(44) 1. Zeiss Victory 1045 T RF range-finding binoculars (with laser ballistic information systemBIS);

(45) 2. Nikon Laser force 1042 mm range-finding binoculars (with a 905 nm laser range finder);

(46) 3. Leica Geovid 1046/1056 range-finder binoculars;

(47) 4. Steiner 830 military LRF binoculars (with laser range-finder and RS232 cable output for a galvanic interface connection); and

(48) 5. Newcon Optik LRB 4000 CI laser range-finder binoculars with an RS232 cable output interface.

(49) The binoculars are used manually to determine range to the target and transmit the range to the fire control system 12D.

(50) There has thus been shown and described a novel method and apparatus for improving the aim of a remote weapon station (RWS), when firing either a point-detonating or a programmable air-burst projectile, that fulfills all of the objects and advantages sought therefor. Many changes, modifications, variations and other uses and applications of the subject invention will, however, become apparent to those skilled in the art after considering this specification and the accompanying drawings which disclose the preferred embodiments thereof. All such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention, which is to be limited only by the claims which follow.