U.S. patent application number 12/660087 was filed with the patent office on 2010-12-16 for applications of directional ammunition discharged from a low velocity cannon.
Invention is credited to Vladimir Smogitel.
Application Number | 20100313741 12/660087 |
Document ID | / |
Family ID | 43305254 |
Filed Date | 2010-12-16 |
United States Patent
Application |
20100313741 |
Kind Code |
A1 |
Smogitel; Vladimir |
December 16, 2010 |
Applications of directional ammunition discharged from a low
velocity cannon
Abstract
A method for destruction of hostile projectiles and a design of
a low velocity cannon firing projectiles that contain directional
ammunition. The method includes: firing from a low velocity cannon
at least one projectile containing directional ammunition and
detonating this directional ammunition at the optimal distance away
from the target.
Inventors: |
Smogitel; Vladimir;
(Manassas, VA) |
Correspondence
Address: |
VLADIMIR SMOGITEL
724 HARRINGTON ROAD
ROCKVILLE
MD
20852
US
|
Family ID: |
43305254 |
Appl. No.: |
12/660087 |
Filed: |
February 19, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61268726 |
Jun 16, 2009 |
|
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|
Current U.S.
Class: |
89/1.11 ;
102/475 |
Current CPC
Class: |
F42B 12/205 20130101;
F42B 12/32 20130101; F42C 19/095 20130101; F42B 12/56 20130101 |
Class at
Publication: |
89/1.11 ;
102/475 |
International
Class: |
F41H 11/02 20060101
F41H011/02; F42B 12/22 20060101 F42B012/22; F41A 19/00 20060101
F41A019/00 |
Claims
1. A method for protecting a second location from a first
projectile fired from a first location at the second location, the
method comprising: (a) firing at least one second projectile
towards the first projectile from a low velocity cannon, said low
velocity cannon discharging projectiles at a velocity substantially
lower than a velocity of a projectile being discharged from a
firearm of a similar caliber; (b) detonating at least one piece of
directional ammunition enclosed within said second projectile; (c)
destroying or damaging the first projectile with shrapnel pieces
generated after detonation of said at least one piece of
directional ammunition.
2. The method of claim 1, further comprising tracking the first
projectile.
3. The method of claim 1, wherein a plurality of second projectiles
being fired at the first projectile.
4. The method of claim 1, wherein said second location being
defined as an airborne vehicle carrying at least one low velocity
cannon, the method further comprising performing at least one
maneuver by said airborne vehicle carrying at least one low
velocity cannon, the purpose of said maneuver being to aim said at
least one low velocity cannon at said first projectile.
5. The method of claim 4, further comprising detonating said at
least one piece of directional ammunition via tension force of at
least one piece of wire, said at least one piece of wire connecting
said at least one second projectile either to said low velocity
cannon or to said airborne vehicle.
6. A counter-projectile weapons system comprising: (a) a low
velocity cannon, said low velocity cannon comprising at least one
firing tube, said at least one firing tube being substantially
lighter than a firing tube of a firearm of a similar caliber; (b)
at least one projectile being able to be discharged from said low
velocity cannon, said at least one projectile containing at least
one piece of directional ammunition; (c) at least one detonator
incorporated into said at least one piece of directional
ammunition; (d) a signal receiver incorporated into said at least
one projectile, said signal receiver being able to initiate
detonation of said at least one piece of directional ammunition
after receiving an appropriate signal.
7. The counter-projectile weapons system of claim 6, further
comprising: (a) a tracker being able to track an incoming
projectile; (b) an array of electronic circuits being able to
receive data from said tracker and being able to automatically fire
said low velocity cannon.
8. The counter-projectile weapons system of claim 6, wherein said
detonator being connected to either said low velocity cannon or any
other structure with at least one piece of wire, the tension force
of said at least one piece of wire acting as said appropriate
signal when said at least one piece of wire becomes fully
stretched.
9. The counter-projectile weapons system of claim 8, further
comprising a mechanism controlling the length of said at least one
piece of wire.
10. A method for protecting a ground combat vehicle from a hostile
missile, the method comprising:(a) detecting and tracking said
incoming hostile missile; (b) firing at least one projectile from
at least one smoke grenade launcher, said at least one smoke
grenade launcher being mounted on said ground combat vehicle; (c)
detonating at least one piece of directional ammunition enclosed
within said at least one projectile; (d) destroying or damaging
said hostile missile via action of shrapnel being discharged by
said at least one piece of directional ammunition.
11. The method of claim 10, wherein said at least one piece of
directional ammunition being detonated via tension force of at
least one piece of wire, said at least one piece of wire connecting
said projectile either to said at least one smoke grenade launcher
or to said ground combat vehicle
12. The method of claim 10, further comprising detecting said
hostile missile via an array of heat sensors, each of said heat
sensors being located closer to a separate said smoke grenade
launcher than to any other smoke grenade launcher mounted on said
ground combat vehicle.
Description
[0001] This patent application claims the benefit of provisional
patent application 61/268,726 filed on Jun. 16, 2009.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to projectiles,
specifically to projectiles carrying directional ammunition, and to
application of low velocity cannons. The present invention also
relates to close-range counter-missile systems.
[0004] 2. Prior Art
[0005] Numerous systems have been developed or under development
for protection of vehicles against hostile guided missiles. Many
different navies possess fairly efficient active counter missile
systems that defeat incoming anti-ship missiles by a super-high
rate of small to medium caliber fire in either a pure kinetic mode
or with assistance of high explosives. Unfortunately, this method
is not applicable to defense of aircraft due to excessive weight of
modern automatic cannons and relative instability of all modern
aircraft, this instability complicating the targeting process. Most
modern aircraft anti-missile defense systems are passive in
nature--they rely upon maneuvering of the aircraft and deployment
of decoys. However, as anti-aircraft missiles are becoming smarter
and more agile these defense strategies are becoming obsolete.
[0006] A review of the existing counter missile systems clearly
indicate the lack of any lightweight and cost effective active
counter-missile systems. The development of efficient counter
missile systems is essential for protection of helicopters,
unmanned aerial vehicles, and fixed wing aircraft operating against
a sophisticated enemy air defense system. To a lesser degree even
ground based combat vehicle rely upon passive measures like armor
and decoys to defeat anti-tank missiles. A low cost, efficient
active anti-missile system is still needed on the modern
battlefield.
SUMMARY OF THE INVENTION
[0007] An objective of the present invention is to provide a novel
close range/extreme close range lightweight weapons system capable
to destroy enemy personnel and incoming hostile projectiles. The
integral part of this weapons system is a low velocity cannon
discharging directional projectiles. In this patent application a
"low velocity cannon" is a projectile discharging cannon operating
at barrel pressures significantly lower than barrel pressure of a
standard firearm. The novel methods incorporated into this design
are simple and effective means to detonate directional projectiles
at the correct distance away from the target thus taking full
advantage of the directional ammunition stored inside each
directional projectile. A number of methods to maintain correct
orientation of the projectiles, i.e. business end towards enemy,
are also discussed later in this patent application. A relatively
big kill-zone generated by detonation of directional ammunition
eliminates the need for precise targeting. Also, application of
directional ammunition allows safe usage of this weapons system at
close distance to the target, since all of the shrapnel travels
only towards the target.
[0008] This weapons system will be particularly useful under all
circumstances where each ounce of extra weight has critical
importance. An example of such circumstances would be deployment of
this weapon system onboard an aircraft that require protection from
incoming hostile projectiles, most likely air or ground launched
anti-aircraft missiles. This aircraft can be a fixed wing jet, a
helicopter, or an unmanned aerial vehicle. An unmanned aerial
vehicle equipped with an efficient counter-missile weapons system
can be effectively used in air combat against enemy aircraft.
[0009] Another advantage of this weapon system is its expected low
cost. The system consists of readily available components that
already exist in the market place and can be easily put together to
make a reliable weapons system. Last but not least, this weapons
system can be easily customized to effectively counter a given
specific threat. The components comprising this weapons system can
be easily replaced to modify weapons parameters. For instance
fire-control electronics can be connected to the target tracker of
the user's choice. By the same token, the same fire control
electronics can be easily used on any low-velocity cannon, provided
the user updates the new cannon's parameters stored in the memory
of the fire-control electronics.
[0010] The basic components comprising this weapons system are the
following: directional ammunition, lightweight projectiles which
act as carriers for directional ammunition, low velocity cannon, at
least one device insuring detonation of directional ammunition at
the right distance away either from the target or from the cannon,
target tracker and/or distance measurement device, a fire-control
electronic circuit either pre-setting weapons system parameters
prior to projectile firing or issuing "detonate ammunition" command
after the projectile has been fired.
[0011] Directional ammunition is readily available and its design
parameters are already well known. Two examples of directional
ammunition are directional claymore mines and case/canister shots.
A case/canister shot is in essence a single shot shotgun firing
pellets forward. Both of these types of ammunition can be easily
designed to generate a stream of pellets of required shape. For
case/canister shot the shape of the canister defines the dispersion
pattern of shrapnel; for claymore mine the dispersion pattern is
defined by the curvature of the shape of the mine.
[0012] The projectiles themselves are just lightweight shells
housing directional ammunition, detonators, and devices required
for detonation of the enclosed ammunition at the right moment. The
projectiles might contain internal holding brackets required to
secure the above-mentioned components in place. The projectiles
need to show acceptable stability in fight therefore they need to
be properly shaped and weight balanced. A spherical shape can be
used or fins and winglets can be attached to the exterior of
projectiles to guarantee acceptable stability in flight. A
projectile carrying directional ammunition needs to be properly
oriented "face towards enemy" at the moment of detonation. An
aerodynamically correct projectile shape can be used to ensure that
the projectile will not tumble in flight and will face the enemy
missile with its business end. An alternative method is to use a
spherical projectile connected to the cannon with a section of wire
of correct length: tension pull of this stretched wire will
correctly orient the projectile at the last moment before
detonation. Other methods to detonate projectiles are discussed in
the "detailed description" section of the current specification.
These projectiles can be discharged from both smoothbore and rifled
firing tubes.
[0013] The projectiles storing directional ammunition are
discharged from a low velocity cannon operating at internal
pressure levels significantly lower than pressure levels imposed on
projectiles inside conventional firearms. In order to be able to
withstand high levels of pressure firearm projectiles, barrels, and
other components are made from strong and heavy materials.
Unfortunately, this requires increased weight of the entire weapons
system. The advantage of the proposed weapons system is its
lightness: a discharged projectile does not need to have enough
kinetic energy to destroy the target. Once the projectile has been
delivered close enough to the target the shrapnel will receive its
kinetic energy from the explosion inside the projectile. Numerous
types of low velocity cannons are available for the user of this
system: a recoilless rifle or a rocket assisted grenade launcher
can easily be used along with one of many spud gun designs
currently popular with hobbyists.
[0014] Once the distance to the target has been correctly estimated
the projectile has to either be pre-programmed to explode at a
certain moment after firing or it has to be detonated after firing
via an external command. It will be up to the user to select the
most appropriate method of projectile detonation out of all methods
presented in this patent application. The preferred method may be
detonating the projectile through tension force of a wire
connecting the projectile itself to the cannon. Another advantage
of this method is that the projectile gets correctly oriented in
space prior to detonation by the same tension force.
[0015] Multitude of various radar-, laser-, and infrared sensor
based distance estimators and trackers are available for any
potential user. If this weapons system is used on any combat
platform, it can be easily integrated with the combat platform's
distance estimators/target trackers and the on-board computer. For
a stand alone weapons system a separate distance estimator/target
tracker is required. Once information on distance to target becomes
available, a simple electronic circuit will be required to track
this parameter (and possibly other parameters) and fire the cannon
once the target gets in range. The user can also choose to control
this weapons system via a digital computer running software of any
level of complexity.
[0016] An array of low velocity cannons connected to target
tracker(s) and controlled electronically can be used for protection
of aircraft, ground vehicles, and fixed installations from hostile
projectiles.
[0017] A novel part of this weapons system is also suggested
methods to aim at a low-velocity cannon at a fast moving target.
Aiming of a fixed cannon can be achieved by maneuvering a craft
that carries this weapons system. A slow moving craft can also be
protected by placing arrays of firing tubes around the craft and
firing only one of these arrays closest to the target. This patent
application also sugstem with existing components onboard modern
fighting vehicles.
DESCRIPTION OF THE DRAWINGS
[0018] This invention is further described in the following
drawings:
[0019] Drawing 1--an engagement of a hostile missile where 1 is the
friendly aircraft, 2 is the low-velocity cannon mounted on a
friendly aircraft, 3 is the wire connecting the counter-missile
projectile to the aircraft, 4 is the projectile discharged from the
low-velocity cannon, 5 is the kill zone saturated with shrapnel, 6
is the hostile missile, said hostile missile positioned within the
kill zone,
[0020] Drawing 2--illustrates that a low-velocity cannon having 2
diverging barrels creates a combined kill zone Dtotal much greater
in size than a kill zone d1 created by a single directional
projectile.
[0021] Drawing 3--two examples of projectiles carrying directional
ammunition where 1 is the wire connecting the cannon to the safety
pin, 2 is the droplet shaped projectile with winglets, 3 is the
safety pin, 4 is the detonator attached to the canister shot, 5 is
the explosives inside the canister shot, 6 is the shrapnel
compartment of the canister shot, 7 is the wire connecting the
cannon to the safety pin inside a spherical projectile, 8 is the
safety pin, 9 is the detonator of the directional claymore mine, 10
is the directional claymore mine stored inside the spherical
projectile, 11 are two kill zones generated by either type of
directional ammunition.
DETAILED DESCRIPTION OF THE INVENTION
[0022] Let me examine a couple of applications of a given weapons
system. One of such applications would be destruction of a fast
moving projectile/missile closing in on a friendly aircraft
equipped with this weapons system. One of the novel ideas behind
this weapons system is to take a relatively inaccurate weapon
discharging slow moving counter-projectiles and destroy a fast
moving target, preferably with one shot.
[0023] Since most anti-aircraft missiles are equipped with remote
fuses the most important parameter to consider is the range of the
missile's warhead. It is possible for the missile's fuse to be
triggered by the explosion of the counter-projectile. Therefore the
missile needs to be intercepted at the minimum distance "D-minimum"
where its explosion is harmless to the aircraft. Of course, the
missile can be intercepted at greater distances as well. This
parameter "D-minimum" will define characteristics of the cannon--at
all altitudes where the threat is likely to be faced by the
aircraft the cannon should be able to deliver a projectile close to
the incoming missile along predictable trajectory within a
reasonable amount of time. The altitude of engagement is important,
since thinner air will offer less resistance to a relatively large
projectile. Although a low velocity cannon will not be able to
discharge a projectile at a high speed, the effective speed of the
projectile will be the sum of its speed and the speed of the
aircraft trying to move away from the incoming missile, assuming
the back hemisphere of the aircraft will be under attack. The first
parameter that the users of this method have to consider is the
maximum desirable distance, which may be greater than "D-minimum",
of missile intercept for a given velocity of the aircraft.
[0024] Once this parameter has been finalized, an appropriate
cannon can be selected. Obviously, the lightest possible cannon
will be chosen for the job. A recoilless rifle or rocket propelled
grenade launcher on board an aircraft will be undesirable due to
generated flame/back blast. Modern day spud gunners use variety of
low velocity cannons using either combustion of gaseous fuel or
compressed gas pressure to propel projectiles. A cannon operated by
compressed gas pressure seems the most desirable element of this
weapons system for the following reason: (a) safety, since there
will be no gaseous fuel on board the aircraft; (b) power, since
compressed gas cannons generate more power than combustion based
low velocity cannons. Compressed gas low velocity cannon offers
another advantage--the power of the discharge blast can be easily
regulated via controlling pressure inside the firing chamber via
remote control valves. Also, an electronically controlled valve
connecting the firing chamber to the firing tube may allow multiple
shots fired from the same cannon without re-pressurizing the firing
chamber. In other words, a longer burst from a lower pressure
chamber can be used as opposed to a short burst of compressed gas
from a high pressure chamber. Alternatively, multiple pressure
chambers can be connected to one firing tube/projectile storage
clip assembly. This arrangement will allow rapid firing of multiple
projectiles from the same firing tube. After every shot a new
projectile will be loaded into the firing tube and a new fully
pressurized chamber will be selected for the next discharge. The
chamber just used will be quickly re-pressurized while other
chambers are being used for firing projectiles. There is another
point that the user of this weapons system may find useful: the
aircraft carrying this weapons system may already have a tank of
pressurized gas to power its own pneumatic devices. If so, the
cannon can be integrated into the pneumatic system of the aircraft
saving the effort of attaching an extra tank of compressed gas to
the cannon.
[0025] Modern day compressed gas cannons routinely hurl projectiles
for hundreds of yards within seconds. This distance combined with
the distance traveled by even a slow moving UAV or helicopter
should be sufficient to intercept any incoming missile at the safe
distance "D-minimum" or even at much greater distances. The firing
tube of a compressed gas cannon can be made either out of plastic
or thin metal thus making the cannon itself very light. The first
design conflict that the user has to resolve is the one between the
power of the cannon and the weight and size of the cannon and
projectiles. The size of the cannon is very important since the
length of the firing tube is directly proportional to the initial
velocity of a discharged projectile and therefore to the effective
range of the cannon.
[0026] According to this method the pilot of the protected aircraft
should become an integral part of the cannon targeting. In other
words once the incoming missile has been detected the pilot has to
perform a maneuver that will ideally make both the aircraft and the
missile move in one line. Ideally, at the end of this maneuver the
cannon affixed to the aircraft should be pointed directly at the
incoming missile. The pilot's task should be made easier by the
fact that most self-guiding missiles are designed to approach the
aircraft along the shortest trajectory. A special display may show
the pilot the relative positions of the aircraft and the missile in
real time, thus helping the pilot to gauge the progress of the
maneuver. This approach appears counter-intuitive since nowadays
pilots are trained to perform evasive maneuvers once a hostile
missile has been detected. However, an airplane equipped with
counter-missile cannon just needs to lure the incoming missile in
the cannon's range for missile's destruction.
[0027] Once the maneuver has been completed the cannon will fire at
least one projectile at the missile. Once the projectile reaches a
pre-determined point directional ammunition on board the projectile
will detonate creating an approximately conical kill zone with its
base turned towards the incoming missile. The kill zone
effectiveness is defined by 2 parameters: size and saturation with
shrapnel. The size of the kill zone is also defined by 2
parameters: the area of the base of the conical kill ("lateral"
dimension of the kill zone) zone and the length of the conical kill
zone ("longitudinal" dimension of the kill zone). The designed
"lateral" dimension of the kill zone should be defined by the
accuracy of the cannon--i.e. the incoming missile has to be inside
the kill zone for the worst probable accuracy of the cannon.
Assuming cannon characteristics are known, the most important
factors affecting accuracy are stability of the airplane during
cannon firing and the type of maneuver being performed by the
aircraft during cannon firing. The type of maneuver executed by the
pilot will be defined partially by the direction from which the
threat is coming. For instance, if a low flying aircraft comes
under attack from ground launched missile the pilot may not have
enough time to complete all necessary maneuvering that will bring
the aircraft in line with the missile's trajectory. Under these
circumstances the user may require a weapons system that will be
able to destroy the incoming missile while the aircraft is
performing a 3D movement relative to the incoming missile.
Obviously, the movement of the aircraft will affect the initial
velocity of the discharged projectile and therefore the accuracy
and aerodynamic characteristics of this weapons system. It is up to
the user to calculate inaccuracy of the cannon for all likely
engagements and compensate for this inaccuracy with the size of the
kill zone.
[0028] The shape of directional ammunition generally defines the
"lateral" dimension of the generated kill zone. Case/canister shots
and directional claymore mines have been around for a long time and
it should be trivial to design a piece of ammunition that will
generate lateral dispersion of shrapnel within required conical
shape. However, there may be a conflict between the size of
ammunition required to generate a kill zone of required size and
the caliber of the low velocity cannon. Also, a bigger projectile
will have to overcome greater resistance of air and may be moving
too slow for the given power of the cannon. The following methods
are suggested to help user generate a required kill zone with
relatively small projectiles: (a) a cannon able to fire multiple
projectiles in rapid succession from the same firing tube; (b) a
cannon firing multiple projectiles from the same firing tube with
one shot; (c) several projectiles fired from different firing tubes
at the same time; (d) a combination of the above-mentioned
methods.
[0029] A cannon firing multiple projectiles should be easy to
build. As long as firing tube/projectile clip assembly is airtight
the clip can be separated from the firing tube with partially
closed spring-loaded plates. After every shot either electrical
solenoids or pneumatic device will retract the plates and a new
projectile will be pushed into the firing tube by the clip spring.
The whole firing tube assembly can be made as one airtight piece
and the projectiles will be loaded into the clip on the ground.
[0030] A sabot full of smaller projectiles can be loaded into the
firing tube. Upon firing the projectiles will start diverging in
flight and after detonation a cluster of possibly overlapping kill
zones will be generated.
[0031] A better dispersion can be achieved by an array of firing
tubes. The angle between longitudinal axes of the firing tubes, the
number and positioning of the tubes, and the design of each
individual projectile will define the size of total kill zone. The
whole assembly may be powered by one pressure chamber connected to
all firing tubes at the same time.
[0032] Firing tubes can be located further apart from each other.
If each firing tube will be aimed at the target and all firing
tubes are used at the same time the target will likely end up in
the area where individual kill zones overlap. If not, the target is
likely to end up in a single non-overlapping kill zone. All of
these methods can be combined together any way the user
desires--for instance, the clip attached to the firing tube may be
loaded with sabots full of projectiles as opposed to projectiles
themselves. Last but not least--the user may choose to load single
counter-missile projectile with more than one piece of directional
ammunition, said pieces being positioned at an angle to each other
and projecting multiple kill zones from one projectile. A variation
of this approach will be using a cluster projectile containing
smaller projectiles, each smaller projectile firing its own
directional/omni-directional ammunition once appropriate projectile
dispersion has been achieved.
[0033] The longitudinal dimension of the kill zone is defined by
the power of explosives of directional ammunition. Effective
longitudinal dimension of the kill zone is the area of the kill
zone where shrapnel elements stay close enough together to
guarantee a hit of the incoming missile that enters the kill zone.
Just like the cannon has to be powerful enough to intercept a
missile at the farthest probable distance, the kill zone has to be
saturated with shrapnel well enough to destroy the smallest
probable threat. The task of missile destruction is facilitated by
the forward motion of the missile thus magnifying the velocity of
the impact between the missile and a piece of shrapnel. Shrapnel
elements made out of lightweight plastic should be sufficient for
this task thus making the ammunition relatively light. Also,
shrapnel can be loaded into the ammunition in multiple layers to
ensure a rough checkerboard pattern of the kill zone. One more
point--if the counter missile projectile is detonated off-center of
the incoming missile then the whole side of the missile becomes
vulnerable to the shrapnel.
[0034] Once the size of the kill zone has been established
counter-missile projectile(s) needs to be detonated at the right
moment after having been fired from the low-velocity cannon.
Obviously, at the moment of the projectile's detonation the missile
has to be close enough to the projectile to end up in the effective
kill zone. A couple of approaches can be used to achieve this task.
All possible methods can be generally broken into 2 categories: the
projectile can be detonated via an external command or the
projectile's detonation parameters can be set prior to firing of
the projectile. There is another method to achieve correct
detonation--making the projectiles themselves "smart" and putting
all necessary target trackers and electronic decision makers
onboard each projectile. However, this method does not seem cost
effective since all smart gear will be lost after explosion of each
projectile.
[0035] Detonating the counter-missile projectile via an external
command may offer better accuracy but will probably be more
complicated and more expensive. Both the incoming missile and the
counter-missile projectile need to be tracked and the "detonate"
command needs to be generated by a dedicated electronic circuit or
by a digital computer running software designed for this task. If a
wireless method to transfer "detonate" command is chosen, the
projectile will have to carry at least one command detector and
extra hardware to convert the command into an actual explosion. A
better way to detonate a projectile via an external command will
probably be sending an electric pulse to the projectile via a
trailing wire. The task of tracking the projectile may be
facilitated by placing a beacon on board the projectile.
[0036] At this point it would be appropriate to mention another
technical problem: at the moment of detonation the projectile
carrying directional ammunition needs to be turned to the incoming
missile with its business end. Assuming the counter-missile
projectile is fired from a smoothbore firing tube, the task of
keeping the projectile correctly oriented can be solved by giving
the projectile an appropriate aerodynamic shape and attaching to
the projectile winglets, fins, or other devices ensuring
projectile's stability in flight. Spin stabilized projectiles can
be used as well, however light plastic is unlikely to survive the
pressures generated by the spinning motion of the projectile inside
the firing tube. This problem can be fixed by enclosing the
projectile into a metal jacket and inserting a metal liner inside
the firing tube. This design change will increase the weight of the
weapons system and will effectively decrease the power of the
discharge since the projectile will have to overcome much higher
friction forces while traveling inside the firing tube.
[0037] Assuming the incoming missile is moving at a steady speed
along well predicted trajectory and assuming consistent performance
of this weapons system, the projectile can be pre-set to explode at
a certain distance away from the aircraft or after a certain period
of time following the projectile's discharge from the firing tube.
The easiest to build detonation system is a spherical projectile
connected to the cannon with a lightweight wire. The wire can be
wound on a spool to prevent wrapping of loose wire around the
projectile in flight--the length of loose wire following the
projectile will be equal to the distance from the projectile to the
cannon. The length of the wire will be the distance away from the
aircraft at which the wire becomes stretched. The tension force of
stretched wire will correctly orient the projectile (which can be
made spherical in shape) and will initiate a train if events
leading to the projectile's detonation, like pulling out a safety
pin. The length of the wire may have to be adjusted for the speed
of the aircraft and the incoming missile to ensure that at the
moment of detonation the projectile is located at a pre-determined
distance away from the aircraft and at the optimal distance away
from the incoming missile. A combination of 2 spinning spools,
spool stoppers, and remotely controlled motors can easily make the
length of the wire that can be stretched easily adjustable in
either way, i.e. longer or shorter. If the length of the wire needs
to be adjusted only in one direction, a single motor driven spool
will suffice. The advantages of such an arrangement are the
following: high reliability (since the detonation system is purely
mechanical), low cost, ease of implementation. Light nylon threads
or other lightweight material can be used to make the wire
connecting each projectile to the cannon. If the cannon is designed
to fire multiple projectiles attached to the firing tube via a
clip, every projectile needs to either be connected to a separate
spool arrangement or an extra mechanical device is required to
connect every new projectile to the single wire/spool combination.
The wire detonation system can be simplified if the length of the
wire is fixed. The drawback of this arrangement is that if the
first missile intercept fails, there will be no way to reprogram
the next projectile and intercept the missile closer to the
aircraft.
[0038] Alternatively, each projectile can be detonated by a command
from an on-board timer. Once a projectile is loaded into the cannon
it will be connected to the aircraft with a short stretch of
conducting wire. This wire will be used to program the timer on
board the projectile prior to firing. Once the projectile leaves
the barrel the tension force of this wire will activate the timer
and the projectile will be detonated when the pre-defined time
period expires. The same stretch of conducting wire can also be
used to recharge projectile's battery needed to set off an electric
blasting cap.
[0039] The decision to fire a counter-missile projectile can be
made either by the pilot of the aircraft, an autonomous electronic
circuit, or a combination of both. A display showing the position
of the incoming missile relative to the aircraft can also show in
real time locations of the kill zone(s). Once the incoming missile
gets close enough to the cannon's range the pilot can activate an
electronic firing circuit that will fire the cannon. If the missile
has been detected while outside the cannon's range, and if a
targeting maneuver has been successfully completed by the pilot the
electronic circuit should make relatively simple calculations to
decide when to discharge a counter-missile projectile. Assuming
both the missile and the aircraft move at a constant speed along
the same flat straight trajectory, the physics of the problem
becomes trivial. The aircraft can be considered to be relatively
motionless in the coordinate system centered around the aircraft
itself. In this coordinate system the missile will be approaching
the aircraft along a straight line, the missile's relative velocity
equal to its real velocity minus the real velocity of the aircraft.
The electronic firing circuit should have access to the cannon's
parameters and it should know how much time it takes a
counter-missile projectile to reach the cannon's maximum range.
Since the incoming missile's position and velocity are consistently
being tracked, the time of the cannon's firing becomes the time it
takes the missile to enter the cannon's range, counting from now,
minus the time it takes a counter-missile projectile to reach the
maximum range.
[0040] Granted, the calculations will be more complicated if the
missile and the aircraft are involves in maneuvering relative to
the ground and relative to each other. For instance, if the angle
of attack of the aircraft is not zero, the relative wind will
affect the trajectory of a fired slow-moving projectile. The cannon
firing circuit, therefore, has to have access to all aircraft
parameters, missile tracker, and valves connecting the firing tube
to pressure chambers, if a compressed gas cannon is used. However,
these calculations should be easy to accomplish provided all
necessary information is available to correctly model the physics
of the engagement. Once the first projectile or a batch of
projectiles has been fired at the missile, an assumption has to be
made that follow up shots may be required. For a counter-projectile
detonated by a wire it means that the length of the wire for the
next available projectile needs to be consistently adjusted under
an assumption that the missile has not been defeated yet. This
continuous adjustment will minimize the time required to perform
the second shot from the cannon. Ideally, the missile will have to
be engaged at a maximum possible distance to allow follow up shots
from the cannon or an arrangement of cannons. Instead of mounting a
separate tracking device on the cannon, this weapons system can be
integrated with the aircraft avionics and use the aircraft radar to
track the incoming missile or, if needed, discharged
counter-missile projectiles.
[0041] Although the targeting of the cannon is mainly performed by
the pilot of the aircraft the user may find it useful to mount the
cannon on a targeting platform. Such a platform may be able to
adjust the cannon's elevation only. Also, the targeting platform
may be able to move the cannon only in pre-set positions as opposed
to allowing the user continuous movement. An advantage of such an
arrangement is that the same cannon can be rapidly moved to a new
position and defeat a threat coming from a totally different
direction. For instance, a helicopter pilot flying his craft close
to the ground may choose to make the cannon point downwards to be
ready for an RPG attack coming from the ground. A targeting
platform capable of continuous adjustment of the cannon's position
can also be used for fine tuning of the targeting process.
[0042] A low velocity cannon discharging directional ammunition can
be used on the ground as well. The same methods to ensure proper
detonation of projectiles can be used for all ground applications.
Arrays of diverging short firing tubes, similar to smoke grenade
launchers can be positioned around an armored vehicle for defense
against anti-tank projectiles. Alternatively, existing smoke
grenade launchers can be easily modified for firing directional
ammunition projectiles as opposed to smoke grenades For simplicity
sake this system can be designed to intercept incoming projectiles
at fixed distance away from the vehicle. This will mean that each
firing tube will be loaded by a projectile connected to the vehicle
with a wire of fixed length. Once a hostile projectile has been
detected one of the arrays of firing tubes will be fired and the
missile will be intercepted at the distance equal to the length of
the wire connecting projectiles to the vehicle. Diverging firing
tubes will create excellent dispersion of the projectiles. Since
most modern armored vehicles carry sophisticated sensors,
application of directional ammunition will ensure that the
vehicle's equipment or friendly troops will not be damaged by
"friendly fire." Obviously, the user can choose omni-directional
ammunition as well. If compressed gas discharge system is selected,
all arrays of firing tubes can be integrated with the vehicle's
pneumatic system, just like it was suggested for application
onboard an aircraft. Incoming missile detection can be easily
achieved by attaching at least one heat sensor to every array of
firing tubes--the heat sensor collecting most IR radiation will be
the heat sensor closest to the incoming missile and associated low
velocity cannon(s) will be fired once the missile gets close enough
to the vehicle. Range estimation based on the heat signature of an
incoming missile/rocket propelled grenade should be trivial to
achieve.
[0043] Low velocity cannons can also be used for defense of any
fixed installation. The overall lightweight of these cannons makes
them easy to move and aim. If mounted on targeting platforms and if
connected to a tank of compressed air with flexible conduits, the
firing tubes can be aimed by relatively low-power motors within
fractions of a second. Of course, the cannons need to be integrated
with hostile projectile detectors and necessary electronic
estimators/fire controllers.
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