U.S. patent application number 11/030649 was filed with the patent office on 2006-08-03 for rocket propelled barrier defense system.
Invention is credited to Richard O. Glasson.
Application Number | 20060169832 11/030649 |
Document ID | / |
Family ID | 36755484 |
Filed Date | 2006-08-03 |
United States Patent
Application |
20060169832 |
Kind Code |
A1 |
Glasson; Richard O. |
August 3, 2006 |
Rocket propelled barrier defense system
Abstract
A system providing a physical-barrier defense against
rocket-propelled grenades (RPGs). The system is suitable for use on
aircraft, ground vehicles, and ships.
Inventors: |
Glasson; Richard O.;
(Whippany, NJ) |
Correspondence
Address: |
Control Products Inc.
280 Ridgedale Avenue
East Hanover
NJ
07936
US
|
Family ID: |
36755484 |
Appl. No.: |
11/030649 |
Filed: |
January 6, 2005 |
Current U.S.
Class: |
244/3.1 ; 342/62;
342/67; 89/1.11 |
Current CPC
Class: |
F41H 13/0006 20130101;
F41H 11/04 20130101 |
Class at
Publication: |
244/003.1 ;
089/001.11; 342/062; 342/067 |
International
Class: |
F41G 7/00 20060101
F41G007/00 |
Claims
1. A system for intercepting a projectile comprising: a detecting
system for identifying the projectile; and a launch system for
launching at least one rocket-towed barrier to intercept the
projectile; wherein the rocket-towed barrier is launched in
response to an instruction of the detecting system.
2. The system of claim 1, wherein the projectile is a rocket
propelled grenade.
3. The system of claim 1, wherein the launch system includes a
plurality of launch pods.
4. The system of claim 1, wherein each of the plurality of the pods
provides a zone of coverage for defense against the projectile.
5. The system of claim 1, wherein the launch system is actively
adjusted to an optimal position for intercept of the
projectile.
6. The system of claim 1, wherein the detecting system is selected
from the group consisting of BAE system'ALQ-156 pulse-Doppler radar
system or ALQ-212 1R warning system.
7. The system of claim 1, wherein the at least one rocket-towed
barrier is actively guided.
8. The system of claim 1, wherein the at least one rocket-towed
barrier is a mesh material.
9. The system of claim 8, wherein the mesh material is selected
from the group consisting Kevlar fiber or stainless steel braided
cables.
10. The system of claim 1, wherein the at least one rocket-towed
barrier provides a wide radius of coverage for intercept of the
projectile along its flight path.
11. The system of claim 1, wherein the rocket-towed barrier is in
shape of a drogue parachute.
12. The system of claim 1, wherein the at least one rocket-towed
barrier is inflated by aerodynamic forces to its maximum
diameter.
13. The system of claim 1, wherein the rocket is mounted fixed
aspect aerodynamic fins to stabilize the rocket in its flight
path.
14. The system of claim 1, wherein the rocket carries flare or
other IR countermeasures.
15. The system of claim 1, wherein the system further includes an
explosive destruct charge.
16. A method for intercepting a launched projectile comprising the
steps of: identifying the launched projectile; predicting a path of
the projectile; and launching a rocket with a pulled barrier behind
the rocket for intercepting the projectile; wherein the barrier is
inflated by aerodynamic forces.
17. The method of claim 16, wherein the projectile is a rocket
propelled grenade.
18. The method of claim 16, wherein the barrier is made of a tear
resistant material.
19. The method of claim 18, wherein the tear resistant material is
a mesh material.
20. The method of claim 16, wherein the barrier provides a wide
radius of coverage for intercept of the projectile along its flight
path.
21. The method of claim 16, wherein the barrier is in shape of a
drogue parachute.
22. The method of claim 16, wherein the barrier is inflated by
aerodynamic forces to its maximum diameter.
23. The method of claim 16, wherein the rocket carries flare or
other IR countermeasures.
24. A method for intercepting a launched target comprising the
steps of: identifying the launched target; and launching more than
one non-explosive projectiles toward the launched targets path for
defense against the launched target; wherein each of the
non-explosive projectiles pulls a barrier that is adapted to
prevent the target from getting through.
25. The method of claim 24, wherein the launched target is a rocket
propelled grenade.
26. The method of claim 24, wherein the barrier is made of a tear
resistant material.
27. The method of claim 26, wherein the tear resistant material is
a mesh material.
28. The method of claim 24, wherein the barrier provides a wide
radius of coverage for intercept of the target along its flight
path.
29. The method of claim 24, wherein the barrier is in shape of a
drogue parachute.
30. The method of claim 24, wherein the barrier is inflated by
aerodynamic forces to its maximum diameter.
31. The method of claim 24, wherein the non-explosive projectiles
carry flare or other IR countermeasures.
Description
BACKGROUND OF THE INVENTION
[0001] Recent conflicts around the world highlight the combat
effectiveness of RPGs. The RPG is often the key "force multiplier"
for terrorist or extremist hostile forces. Helicopter downings by
RPGs have become an increasingly deadly factor in recent major
conflicts. Multiple incidents in Somalia, Afghanistan, and Iraq
have involved significant loss of life. Such incidents provide
encouragement and disproportionate stature to hostile forces.
Additionally, missiles and RPGs pose an emerging threat to
passenger and cargo aviation as well as to ground transports.
SUMMARY OF THE INVENTION
[0002] The present invention describes an expendable Rocket-Towed
Barrier (RTB) system designed to prevent RPGs from reaching their
targets. The system is comprised of: [0003] Vehicular-mounted
launch pod(s) [0004] Multiple RTB expendable countermeasures
[0005] The system utilizes existing technologies for the
identification and targeting of threats. The system takes advantage
of the fact that RPGs and personnel-fired missiles are, in terms of
combat projectiles, relatively slow-moving and there is a short
time available to identify threats and launch countermeasures. Each
RTB launch pod provides a zone of coverage. The actual RTB
projectile does not need to precisely intercept the incoming
munition. Furthermore, the launch of several RTB projectiles in a
pattern toward the path of the incoming threat will provide a very
high likelihood of interception. Unlike other proposals, such as
explosive ball bearing grenades, this system presents an effective
counter to lethal munitions while maintaining a low probability of
collateral damage to non-combatants in the launch vicinity.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The present invention is described with reference to the
following figures, in which:
[0007] FIG. 1 shows the area of coverage provided by several
rocket-towed barriers, superimposed upon the outline of a
helicopter;
[0008] FIG. 2 shows the Launch sequence of a single rocket-towed
barrier;
[0009] FIG. 3 shows a rocket-towed barrier on an intercepting
course between a helicopter and a threat missile.
DETAILED DESCRIPTION OF THE INVENTION
[0010] In one embodiment, the launch pod is a simple weatherproof
cluster of thermoplastic tubes. Launch pods are attached to the
host vehicle in such a way that the launch tubes are directed
toward the zone from which RPG protection is desired. The system
interfaces with a threat identification system, such as the BAE
Systems ALQ-156 pulse-Doppler radar system, or the ALQ-2I2 IR
warning system, both of which are now in widespread use. Threat
direction and time-to-go data are used to determine the optimum
firing time for the RTB countermeasures. In this respect, the
system is almost identical to current chaff or IR decoy
countermeasure systems, with the distinction that the present
system is designed to physically intercept the threat munition,
thereby providing a significantly greater degree of security.
Additionally, IR and chaff decoy systems provide no defense against
RPGs, which are essentially ballistic projectiles having no
in-flight seek or guidance capabilities. In another embodiment, the
countermeasure-firing pod is actively aimed using rapid-acting
electromechanical or fluid powered actuators similar to systems in
current use such as the Raytheon Phalanx Close In Weapon System
(CIWS). Data from the radar system is used to point the
countermeasure launch tube(s) on an approximate intercepting
trajectory, taking account of velocities of the threat, the
countermeasure, and the host vehicle. The present system would be
smaller and simpler than current CIWS systems primarily because the
rate of fire is much lower and the projectiles are self-propelled,
requiring only a launch tube. An additional simplifying factor is
that precise threat intercept (hitting a bullet with a bullet) is
not a requirement of the present system. In yet a more complex
embodiment, the RTB countermeasure may employ active guidance. This
system would offer tracking and in-flight course correction.
Assuming active guidance combined with accurate data on the flight
path of the threat, it may be possible to deliver the threat
munition back to its point of origin.
Expendable Countermeasure
[0011] The expendable RTB utilizes a quick firing, single-stage
solid-fueled rocket. The RTB rocket is similar in most respects to
a hobby rocket, with necessary enhancements for sizing, flight
stability, and mission reliability. The RTB rocket tows a mesh
barrier that, after launch, is inflated by aerodynamic forces. The
inflated barrier provides a wide radius of coverage for intercept
of incoming threats along the RTB flight path.
Towed Barrier
[0012] In one embodiment, the towed barrier is in the shape of a
small, flat drogue parachute. The drogue-shaped barrier is
aerodynamically symmetric, resembling an aircraft-braking
parachute, but is constructed of a mesh material that presents a
physical barrier to oncoming munitions, while allowing most
oncoming air to pass through. The mesh material may be Kevlar
fiber, stainless steel braided cable, or a combination of
materials. The mesh is optimized for strength and aerodynamic drag
characteristics. The drogue tethers are fixed to the tow rocket
fuselage in such a way as to provide uniform pull force when the
drogue is inflated. The tethers are constructed to withstand the
initial shock of encountering an RPG. The tether system may employ
an elastic element to partially dissipate the kinetic energy of a
captured or diverted RPG. The drogue exploits aerodynamic forces to
maintain maximum frontal area with respect to the RTB flight path.
The drogue/rocket package is optimized for threat interdiction. The
drogue is intentionally designed to slow the RTB rocket to the
optimum velocity for maximum time-in-the-path of incoming threats.
Mesh barriers of other shapes are operable with this system. In a
further embodiment, a mesh barrier of rectangular frontal aspect is
deployed. Larger barriers may employ multiple tow rockets in order
to maintain the desired cross-section during threat
interdiction.
Stowage
[0013] In one embodiment the towed barrier is packed with the RTB
rocket as a unit. The barrier is folded and wrapped into a compact
package that is formed around the rocket. At launch, the rocket
first leaves the launch tube pulling the barrier tethers along
behind it. The tethers in turn pull the drogue out of its folded
state and out of the launch tube. As the drogue clears the launch
tube and proceeds along the flight path, aerodynamic forces cause
it to inflate to its maximum diameter. Certain areas of the towed
barrier may be subject to high heat from the tow rocket. In
particular, the area directly behind the tow rocket. Since the
countermeasure is expendable, and the flight duration is on the
order of a few seconds, this would not seriously degrade the
effectiveness of the system. In RTB systems with more demanding
mission requirements, the towed barrier may be fitted with a heat
protective coating in the area of the rocket exhaust. The
drogue/rocket package may be stored as a unit, in its own
expendable launch tube. Such a system would facilitate quick and
easy replacement of discharged countermeasures, much as current
chaff dispensing system. In another embodiment, the complete launch
tube units may be incorporated into a magazine, or an ammunition
belt configuration.
Guidance
[0014] Rocket stabilization and guidance may take one of several
forms depending on the system complexity as described above. In one
embodiment fixed aspect aerodynamic fins are used to stabilize the
RTB rocket on its flight path. The fins may extend via spring
pressure after ejection from the launch tube. Another embodiment
provides inertial stabilization through the use of a spinning mass.
A tubular section of the rocket fuselage spins around the axis of
flight. The spin motion may be imparted via an ablative multi-vane
impeller that is coupled to the rotating section and situated along
the rocket axis. A portion of the rocket exhaust drives the
impeller. Active guidance via moveable control surfaces may also be
employed. Active guidance methods are established in the art, and
are not an object of the present invention.
Additional Defensive Capabilities
[0015] The RTB rocket may carry flare or other IR countermeasures,
thus doubling as a decoy for heat-seeking threats and attracting
those threats into the effective radius of the RTB
countermeasure.
Explosive Interdiction
[0016] The RTB may additionally be equipped with an explosive
destruct charge that destroys or disables threat munitions that are
in the vicinity of the RTB. The destruct charge triggers when force
on drogue tethers exceeds a predetermined value. The destruct
charge combines with the physical barrier to provide enhanced
capabilities to the RTB system. Explosive RTBs may be effective
against threats that could defeat the drogue netting alone (such as
SAMs and personnel fired missiles). In-flight arming of the
destruct charge safeguards the host vehicle from accidental
detonation and from detonation during the initial shock of the
inflation of the towed barrier. In one embodiment, a MEMS G sensor
integrates flight time away from host to provide a safe arming
distance. Hall-effect sensors and spring-mounted magnet provide
non-contacting force trigger. The towed barrier tethers are
connected to the spring-mounted magnet. After arming, the
appropriate force on the tethers brings the magnet sufficiently
close to the hall-effect sensors to trigger an electrical impulse
to the destruct charge. Additional destruct charge fusing methods
could be employed including heat sensing, proximity, or time-delay
methods.
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