MULTILAYERED ASSET PROTECTION SYSTEM

Description

STATEMENT OF GOVERNMENT INTEREST

Under paragraph 1(a) of Executive Order 10096, the conditions under which this invention was made entitle the Government of the United States, as represented by the Secretary of the Army, to an undivided interest therein on any patent granted thereon by the United States. This and related patents are available for licensing to qualified licensees.

BACKGROUND

Field of the Invention

The present invention relates to asset protection systems and, more specifically, to multilayered systems for protecting assets from attack including aerial attack.

Description of the Related Art

This section introduces aspects that may help facilitate a better understanding of the invention. Accordingly, the statements of this section are to be read in this light and are not to be understood as admissions about what is prior art or what is not prior art.

Kamikaze UAVs (Unmanned Aerial Vehicles) are widely used in combat operations. For example, drones can be equipped with destructive weapons, including explosives. They are difficult to fight due to their high speed and maneuverability. In one example, a defense system utilizes a lattice screen made of a lattice of flat extended metal elements. In another example, U.S. Pat. No. 8,857,309 discloses a netting of knotted and coated super strong fibers disposed in front of a protected object and configured to deform a rocket caught in the netting through strangulation, thereby disabling the detonator thereof.

SUMMARY

Embodiments of the present invention are directed to protective systems capable of withstanding an attack by a Group 3 unmanned aerial system (UAS) representing a typical drone. A Group 3 UAS can possess up to 4.2 MJ of kinetic energy and a 50 kg warhead. A conventional design would consist of a hardened structure to defeat all aspects of this threat. A hardened structure of sufficient robustness would be extremely challenging to design, prohibitively costly, and time consuming to construct.

To address this challenge, a multilayer system has been developed for protecting an asset from UAS drone attacks. In one embodiment, the system includes an outer tension based primary mesh member, two separated, structurally independent layers of netting (first or inner net and second or outer net) supported to be laterally interconnected rigid columns with controlled stiffness elements (springs) attached the top of each column, and a hard layer forming a rigid hardened enclosure encasing or enclosing the asset.

According to an aspect the present invention, an asset protection system comprising a first netting system and a second netting system. The first netting system includes first columns disposed around an asset disposed on a bottom surface, each first column having a first column bottom attached to the bottom surface and a first column top, first springs connected to first column tops of the first columns, first cables connected to the first springs, and first nets connected to the first cables, the first nets including one or more first interior nets and first peripheral nets which surround the one or more first interior nets and which are connected to one or more of the first cables which are connected to the bottom surface. The second netting system includes second columns disposed around the asset, each second column having a second column bottom attached to the bottom surface and a second column top, second springs connected to second column tops of the second columns, second cables connected to the second springs, and second nets connected to the second cables, the second nets including one or more second interior nets and second peripheral nets which surround the one or more second interior nets and which are connected to one or more of the second cables which are connected to the bottom surface. The first nets are disposed between the asset and the second nets.

In some embodiments, the first columns are disposed around the asset. The first springs are connected to first column tops of the first columns. The first cables are connected to the first springs connected to the first column tops, the first cables including first interior cables each being connected between one first spring connected to one of the first column tops and another first spring connected to another one of the first column tops, and first peripheral cables each connected at one end to one first spring connected to one of the first column tops and at another end to the bottom surface. The one or more first interior nets have first interior net edges connected to the first cables, each first interior net having a set of the first interior net edges connected to a set of the first interior cables surrounding said each first interior net. The first peripheral nets have first peripheral net edges connected to the first cables, each first peripheral net having a set of the first peripheral net edges connected to a set of the first cables which, together with the bottom surface, surround said each first peripheral net.

In specific embodiments, the second columns are disposed around the asset. The second springs are connected to second column tops of the second columns. The second cables are connected to the second springs connected to the second column tops, the second cables including second interior cables each being connected between one second spring connected to one of the second column tops and another second spring connected to another one of the second column tops, and second peripheral cables each connected at one end to one second spring connected to one of the second column tops and at another end to the bottom surface. The one or more second interior nets have second interior net edges connected to the second cables, each second interior net having a set of the second interior net edges connected to a set of the second interior cables surrounding said each second interior net. The second peripheral nets have second peripheral net edges connected to the second cables, each second peripheral net having a set of the second peripheral net edges connected to a set of the second cables which, together with the bottom surface, surround said each second peripheral net.

According to another aspect the present invention, an asset protection system comprising a first netting system and a second netting system. The first netting system includes a plurality of first columns disposed around an asset which is disposed on a bottom surface. Each first column has a first column bottom attached to the bottom surface and a first column top. A plurality of first springs are connected to first column tops of the first columns. A plurality of first cables are connected to the first springs connected to the first column tops. The first cables include first interior cables each being connected between one first spring connected to one of the first column tops and another first spring connected to another one of the first column tops, and first peripheral cables each connected at one end to one first spring connected to one of the first column tops and at another end to the bottom surface. One or more first interior nets have first interior net edges connected to the first cables. Each first interior net has a set of the first interior net edges connected to a set of the first interior cables surrounding said each first interior net. A plurality of first peripheral nets have first peripheral net edges connected to the first cables. Each first peripheral net has a set of the first peripheral net edges connected to a set of the first cables which, together with the bottom surface, surround said each first peripheral net. The second netting system includes a plurality of second columns disposed around the asset. Each second column has a second column bottom attached to the bottom surface and a second column top. A plurality of second springs are connected to second column tops of the second columns. A plurality of second cables are connected to the second springs connected to the second column tops. The second cables include second interior cables each being connected between one second spring connected to one of the second column tops and another second spring connected to another one of the second column tops, and second peripheral cables each connected at one end to one second spring connected to one of the second column tops and at another end to the bottom surface. One or more second interior nets have second interior net edges connected to the second cables. Each second interior net has a set of the second interior net edges connected to a set of the second interior cables surrounding said each second interior net. A plurality of second peripheral nets have second peripheral net edges connected to the second cables. Each second peripheral net has a set of the second peripheral net edges connected to a set of the second cables which, together with the bottom surface, surround said each second peripheral net.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will become more fully apparent from the following detailed description, the appended claims, and the accompanying drawings in which like reference numerals identify similar or identical elements.

FIG. 1 is a perspective view of a first netting system for protecting an asset.

FIG. 2 is a top plan view of the first netting system of FIG. 1.

FIG. 2A is a perspective view of a first column with first springs connected to first column top in the first netting system of FIG. 1.

FIG. 3 is a perspective view of a second netting system for protecting the asset.

FIG. 4 is a top plan view of the second netting system of FIG. 3.

FIG. 5 is a perspective view of a mesh system for protecting the asset.

FIG. 6 is a top plan view of the mesh system of FIG. 5.

FIG. 7 is a schematic view of the asset protected by a multilayered asset protection system including a hard layer, the first netting system of FIGS. 1-2, the second netting system of FIGS. 3-4, and the mesh system of FIGS. 5-6.

FIG. 8 is a Table of UAS group comparison between five groups with Group 1 as the baseline.

FIG. 9 shows a protection scenarios overview.

FIG. 10 shows an example of a probability impact matrix.

FIG. 11 shows an example of a risk analysis overview.

FIG. 12 shows an example of protection scenarios for the threat of kinetic energy as part of the risk analysis.

FIG. 13 shows an example of protection scenarios for the threat of impact force as part of the risk analysis.

FIG. 14 shows an example of protection scenarios for the threat of overpressure as part of the risk analysis.

FIG. 15 shows an example of protection scenarios for the threat of fragmentation as part of the risk analysis.

FIG. 16 shows an example of extremely high risk for an UAS no capture with detonation.

FIG. 17 shows an example of high risk for an UAS impact no detonation.

FIG. 18 shows an example of low risk for a no detonation intact UAS capture.

FIG. 19 shows an example of low risk for a no detonation intact UAS capture.

FIG. 20 shows an example of low risk for a no detonation disintegrated UAS capture.

FIG. 21 shows an example of moderate risk for a no detonation disintegrated UAS capture.

FIG. 22 shows an example of low risk for a no detonation disintegrated UAS impact.

FIG. 23 shows an example of moderate risk for a detonation disintegrated UAS.

FIG. 24 shows an example of moderate risk for a detonation disintegrated UAS.

FIG. 25 shows an example of low risk for a detonation disintegrated UAS.

DETAILED DESCRIPTION

Detailed illustrative embodiments of the present invention are disclosed herein. However, specific structural and functional details disclosed herein are merely representative for purposes of describing example embodiments of the present invention. The present invention may be embodied in many alternate forms and should not be construed as limited to only the embodiments set forth herein. Further, the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments of the invention.

As used herein, the singular forms “a,” “an,” and “the,” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It further will be understood that the terms “comprises,” “comprising,” “includes,” and/or “including,” specify the presence of stated features, steps, or components, but do not preclude the presence or addition of one or more other features, steps, or components. It also should be noted that in some alternative implementations, the functions/acts noted may occur out of the order noted in the figures. For example, two figures shown in succession may in fact be executed substantially concurrently or may sometimes be executed in the reverse order, depending upon the functionality/acts involved.

1. Overview

The design of a physical asset protection system starts with defining the threat, the threat factors, the risk factors, and the goals. The system may be designed to protect against a variety of threats. One example of a threat is a 500-kg object with a 50-kg warhead, traveling at 129 m/s, with an estimated kinetic energy of 4.2 MJ (e.g., a 20-ton truck traveling at 50 mph). The asset protection system in this disclosure may be designed to protect the asset against a ground vehicle and/or an unmanned aerial system (UAS). Because conventional mechanisms are effective in countering ground vehicle attack (e.g., walls, columns, or other ground barriers), the focus of this disclosure is a counter UAS asset protection system.

The threat factors of a threat may include kinetic energy, impact force, overpressure, and fragmentation. The kinetic energy refers to the threat energy from motion. The impact force refers to the disintegration large byproducts with low-speed impacts. The overpressure refers to the blast wave importing force. The fragmentation refers to the detonation small byproducts at high-speed impacts.

The obvious risk factors associated with detonation are overpressure and fragmentation. With no detonation, the risk factors are that the UAS will remain intact and thus will remain an explosive threat or the UAS will remain disintegrate over time.

The goals of the physical asset protection system may include (i) preventing loss of the asset, (ii) preventing denial of use of the asset, (iii) protecting items inside the asset, (iv) minimizing the recovery time, and (v) minimizing the recovery cost.

2. Multilayered Asset Protection System

Embodiments of the invention are directed to a Multilayer Asset Protection System (MAPS) which provides multiple features each tailored to addressing a specific aspect of the threats posed by a UAS. The first feature is a tension based primary mesh member (e.g., a coarse mesh having 1-m holes configured to dismember drones, which may be configured as a cable mesh) to detach the wings or fragment from the UAS. The next two layers (e.g., an inner net and an outer net) absorb the kinetic energy of the UAS and provide a known detonation distance from the asset. The two nets are provided to increase the probability of capture and subsequent possible detonation of the warhead. The MAPS may include additional nets or netting layers. The rigid hardened structure (e.g., the hard layer), designed for the known detonation overpressure and enclosing the asset, absorbs and deflects any blast overpressure and detonation remnants from reaching the asset. Each layer, other than the tension based primary mesh member and outer net layer, are independent of each other to provide options based upon the group of the UAS threat, sensitivity of the asset to blast overpressure and detonation remnants, and constructability and ease of repair.

FIG. 1 is a perspective view of a first netting system 100 for protecting an asset 102. FIG. 2 is a top plan view of the first netting system of FIG. 1.

The first netting system 100 includes a plurality of first columns 110 disposed around the asset 102 which is disposed on a bottom surface 104 or ground 104. Each first column 110 has a first column bottom 112 attached to the bottom surface and a first column top 114. A plurality of first controlled stiffness elements or first springs 120 are connected to the first column tops 114 of the first columns 110. A plurality of first cables 130 are connected to the first springs 120 which are connected to the first column tops 114. The first cables 130 include first interior cables 130A each being connected between one first spring 120 connected to one of the first column tops 114 and another first spring 120 connected to another one of the first column tops 114. The first cables 130 further include first peripheral cables 130B each connected at one end to one first spring 120 connected to one of the first column tops 114 and at another end to the bottom surface 104.

FIG. 2A is a perspective view of a first column 110 with first springs 120 connected to the first column top 114 in the first netting system 100 of FIG. 1. The first column 110 may be an I-beam or some other structure having other shapes (e.g., square, circular, rectangular, etc.) that are solid or hollow. In the example shown, four first springs 120 are connected to each first column top 114 for simplicity. For some first column tops 114, all four first springs 120 are connected to the first cables 130. For other first column tops 114, fewer than four first springs 120 are connected to the first cables 130. In a different embodiment, three first springs 120 are connected to each first column top 114. In another embodiment, the number of first springs 120 connected to each first column top 114 may vary among the first column tops 114. The first springs 120 may be first coil springs. Each first spring 120 is connected at most to one first cable 130. Alternatively, at least one first spring 120 may be connected to a plurality of the first cables 130. Such a configuration may result in a weak spot for the first netting system 100, unless those first springs which are connected to multiple first cables are stronger springs capable of absorbing more energy than the other first springs which are each connected to only one first cable.

Coil springs are readily available. Coil springs have a self-healing feature in that they get re-tensioned automatically. The resilient feature of the springs 120 causes incoming objects to be redirected. The energy may be largely deflected instead of being fully absorbed by the protection system. The length of each coil spring may be about 0 meter, although it may range from 0.8-1.5 meters or 0.6 to 2 meters, or beyond in other embodiments.

One or more first interior nets 140 have first interior net edges 142 connected to the first cables 130. Each first interior net 140 has a set of the first interior net edges 142 connected to a set of the first interior cables 130A surrounding that first interior net 140. In the example shown, most of the first interior nets 140 have four first interior net edges 142 connected to a set of four first interior cables 130A.

A plurality of first peripheral nets 150 have first peripheral net edges 152 connected to the first cables 130. Each first peripheral net 150 has a set of the first peripheral net edges 152 connected to a set of the first cables 130 which, together with the bottom surface 104, surround that first peripheral net 150. The set of the first cables 130 may include at least one first interior cable 130A and/or at least two first peripheral cables 130B.

FIG. 3 is a perspective view of a second netting system 300 for protecting the asset. FIG. 4 is a top plan view of the second netting system of FIG. 3.

The second netting system 300 includes a plurality of second columns 310 disposed around the asset 102. Each second column 310 has a second column bottom 312 attached to the bottom surface 104 and a second column top 314. A plurality of second springs 320 are connected to the second column tops 314 of the second columns 310. A plurality of second cables 330 are connected to the second springs 320 which are connected to the second column tops 314. The second cables 330 include second interior cables 330A each being connected between one second spring 320 connected to one of the second column tops 314 and another second spring 320 connected to another one of the second column tops 314. The second cables 330 further include second peripheral cables 330B each connected at one end to one second spring 320 connected to one of the second column tops 314 and at another end to the bottom surface 104.

In the example shown, four second springs 320 are connected to each second column top 314 for simplicity. For some second column tops 314, all four second springs 320 are connected to the second cables 330. For other second column tops 314, fewer than four second springs 320 are connected to the second cables 330. In a different embodiment, three second springs 320 are connected to each second column top 314. In another embodiment, the number of second springs 320 connected to each second column top 314 may vary among the second column tops 314. The second springs 320 may be second coil springs. Each second spring 320 is connected at most to one second cable 330. Alternatively, at least one second spring 320 may be connected to a plurality of the second cables 330. Such a configuration may result in a weak spot for the second netting system 300, unless those second springs which are connected to multiple second cables are stronger springs capable of absorbing more energy than the other second springs which are each connected to only one second cable.

One or more second interior nets 340 have second interior net edges 342 connected to the second cables 330. Each second interior net 340 has a set of the second interior net edges 342 connected to a set of the second interior cables 330A surrounding that second interior net 340. In the example shown, most of the second interior net 340 have four second interior net edges 342 connected to a set of four second interior cables 330A.

A plurality of second peripheral nets 350 have second peripheral net edges 352 connected to the second cables 330. Each second peripheral net 350 has a set of the second peripheral net edges 352 connected to a set of the second cables 330 which, together with the bottom surface 104, surround that second peripheral net 350. The set of the first cables 130 may include at least one second interior cable 330A and/or at least two second peripheral cables 330B.

The one or more first interior nets 140 and the first peripheral nets 150 are disposed between the asset 102 and the one or more second interior nets 340 and the second peripheral nets 350. The first nets (140, 150) surround the asset 102. The second nets (340, 350) surround the first nets (140, 150). The second columns 310 extend to the second column tops 314 above the one or more first interior nets 140 and the first peripheral nets 150. The one or more first interior nets 140 and the first peripheral nets 150 may be formed with openings through which the second columns 310 extend to the second column tops 314. Alternatively, the second columns 310 may be positioned between the first cables 130 to allow the first interior net edges 142 and the first peripheral net edges 152 connected to the first cables 130 to surround the second columns 310.

In a two-layer embodiment, the system has an inner layer (first layer) and an outer layer (second layer). In a three-layer embodiment, the system has an inner layer (first layer), an intermediate or middle layer (second layer), and an outer layer (third layer). In an N-layer embodiment, the system has an inner or innermost layer (first layer), N-2 intermediate layers (second layer to N-1th layer), and an outer or outermost layer (Nth layer).

FIG. 5 is a perspective view of a mesh system 500 for protecting the asset. FIG. 6 is a top plan view of the mesh system of FIG. 5. The mesh system 500 includes one or more interior meshes 540 disposed above the asset 102, the one or more first interior nets 140, and the one or more second interior nets 340. A plurality of peripheral meshes 550 are disposed around the asset 102, the first peripheral nets 140, and the second peripheral nets 340. The one or more first interior nets 140, the first peripheral nets 150, the one or more second interior nets 340, and the second peripheral nets 350 are disposed between the asset 102 and the one or more interior meshes 540 and the peripheral meshes 550.

A plurality of column extensions 516 extend upward from the second column tops 314 to a plurality of column extension tops 520. A plurality of mesh cables 530 are connected to the column extension tops 520. The mesh cables 530 include interior mesh cables 530A each being connected between one of the column extension tops 520 and another one of the column extension tops 520, and peripheral mesh cables 530B each connected at one end to one of the column extension tops 520 and at another end to the bottom surface 104.

The one or more interior meshes 540 have interior mesh edges 542 connected to the mesh cables 530. Each interior mesh 540 has a set of the interior mesh edges 542 connected to a set of the interior mesh cables 530A surrounding that interior mesh 540. In the example shown, most of the interior meshes 540 have four interior mesh edges 542 connected to a set of four second interior cables 530A.

A plurality of peripheral meshes 550 have peripheral mesh edges 552 connected to the mesh cables 530. Each peripheral mesh 550 has a set of the peripheral mesh edges 552 connected to a set of the mesh cables 530 which, together with the bottom surface 104, surround that peripheral mesh 550.

2.1. Materials & Sizes of the Mesh and Netting System Components

The material for the nets (140, 150, 340, 350) is selected to meet the energy load requirement. The layers may be made of one or more materials including metal (e.g., steel cables), polymers, and composites. In specific embodiments, the layers may be made of 100% nylon or a combination of nylon and one or more other materials (e.g., hemp). One commercially available material is Frictape from Frictape Ltd of Finland. One Frictape product is a nylon net with 5-cm openings or holes. The one or more first interior nets 140, the first peripheral nets 150, the one or more second interior nets 340, and the second peripheral nets 350 may include nylon and may have 5-cm openings. The size of the openings may vary. A different size may be selected (e.g., 4 cm to 6 cm).

The one or more interior meshes and the peripheral meshes may have 1-m openings. The one or more interior meshes and the peripheral meshes may comprise polymer or polymer-hemp material. The first cables 130, the second cables 330, and the mesh cable 530 may comprise metal or polymer material. The first columns 110 and the second columns 310 may comprise metal, composite, or metal and composite hybrid material.

2.2. Connections and Spacings of the Mesh and Netting System Components

The one or more first interior nets 140 and the first peripheral nets 150 may be connected to the first cables 130 by polymer straps, polymer-hemp straps, polymer cables or metal (e.g., steel) cables. The one or more second interior nets 340 and the second peripheral nets 350 may be connected to the second cables 330 by polymer straps, polymer-hemp straps, polymer cables, or metal (e.g., steel) cables.

The one or more first interior nets 140 and the first peripheral nets 150 may be spaced from the one or more second interior nets 340 and the second peripheral nets 350 by a minimum distance of about three feet (e.g., +10%).

The one or more interior meshes 540 and the peripheral meshes 550 may be connected to the mesh cables 530 by polymer straps, polymer-hemp straps, polymer cables, or metal (e.g., steel) cables.

The one or more interior meshes 540 and the peripheral meshes 550 may be spaced from the one or more second interior nets 340 and the second peripheral nets 350 by a minimum distance of about three feet (e.g., +10%).

2.3. Hard Layer

FIG. 7 is a schematic view of the asset protected by a multilayered asset protection system 800 including a hard layer 700, the first netting system 100 of FIGS. 1-2, the second netting system 300 of FIGS. 3-4, and the mesh system 500 of FIGS. 5-6. The use of a hard layer 700 and a plurality of nets delivers the maximum protection at a minimum cost in general. Increasing distance to detonation decreases the TBI (Traumatic Brain Injury) occurrence and risk.

The hard layer 700 may be made of concrete, steel reinforced concrete, metal(s), or composite material(s). In embodiments, a standard or regular hard layer includes 5 inches of concrete. A heavy layer includes 12 inches of concrete. An extra heavy layer includes 24 inches of concrete.

The hard layer 700 is a structure disposed around the asset 102 and disposed between the asset 102 and the at least first interior net 140 and the first peripheral nets 150. The one or more first interior nets 140 and the first peripheral nets 150 may be spaced from the hard layer structure 700 by a minimum distance of about twenty feet (e.g., +10%).

3. Threat Factor Analysis

FIG. 8 is a Table of UAS group comparison between five groups with Group 1 as the baseline. Each group has its associated energy, mass, speed, and payload. Group 3 represents an example of a typical drone.

FIG. 9 shows a protection scenarios overview. The threat response measure involves utilizing two net layers or utilizing two net layers plus one hard layer (5 inches of concrete) at reasonable costs. The overpressure and fragmentation are not issues for two net layers.

The threat factor analysis and the risk analysis in this disclosure are presented for a multilayered asset protection system without the mesh layer. Additional protection at much higher costs include utilizing one extra heavy layer (12 inches of concrete) to absorb the threat, utilizing one or more net layers plus multiple extra heavy layers (12 inches and 24 inches of concrete), or utilizing a blast resistant robust structure as new construction. These measures further reduce the threats of kinetic energy, impact force, overpressure, and fragmentation.

4. Risk Analysis

FIG. 10 shows an example of a probability impact matrix. It is a risk assessment matrix involving probability (expected frequency) categories of frequent (continuous, regular, or inevitable occurrences), likely (several or numerous occurrences), occasional (sporadic or intermittent occurrences), seldom (infrequent occurrences), and unlikely (possible occurrences but improbable), and severity (expected consequence) categories of catastrophic (mission failure, unit readiness eliminated, death, unacceptable loss of damage), critical (significantly degraded unit readiness or mission capability, severe injury, illness, loss, or damage), moderate (somewhat degraded unit readiness or mission capability, minor injury, illness, loss, or damage), and negligible (little or no impact to unit readiness or mission capability, minimal injury, loss, or damage).

Extremely high risk exists for catastrophic and critical severity levels under frequent on the frequency scale and catastrophic severity level under likely on the frequency scale. High risk exists for moderate severity level under frequent on the frequency scale, critical severity level under likely on the frequency scale, catastrophic and critical severity levels under occasional on the frequency scale, and catastrophic severity level under seldom on the frequency scale. Medium risk exists for negligible severity level under frequent on the frequency scale, moderate severity level under likely and occasional on the frequency scale, critical severity level under seldom on the frequency scale, and catastrophic severity level under unlikely on the frequency scale. Low risk exists for negligible severity level under likely and occasional on the frequency scale, moderate and negligible severity levels under seldom on the frequency scale, and critical, moderate, and negligible severity levels under unlikely on the frequency scale.

FIG. 11 shows an example of a risk analysis overview. The current risk is extremely high at catastrophic severity level under frequent on the frequency/probability scale because the asset is not protected from the UAS has detonated and the UAS impact has caused damage to the asset with threat effects of kinetic energy, impact force, overpressure, and fragmentation. The current risk is high at catastrophic severity level under seldom on the frequency/probability scale because the asset Is not protected from the UAS remains intact and the UAS impact has caused damage to the asset with threat effects of kinetic energy and impact force.

The risk is moderate at moderate severity level under occasional on the frequency/probability scale because the UAS has detonated and the UAS impact has caused damage to the inner net and the hard layer with threat effects of kinetic energy, impact force, overpressure, and fragmentation. The risk is moderate at negligible severity level under frequent on the frequency/probability scale because the UAS has detonated and the UAS impact has caused damage to the outer net and the hard layer with threat effects of kinetic energy, impact force, overpressure, and fragmentation. The risk is moderate at negligible severity level under seldom on the frequency/probability scale because there is no UAS detonation and the UAS impact has caused damage to the outer net and the hard layer with threat effects of kinetic energy and impact force.

The risk is low at critical severity level under unlikely on the frequency/probability scale because there is no UAS detonation and the UAS impact has caused damage to the outer net and the inner net with threat effects of kinetic energy and impact force, or because the UAS has detonated and the UAS impact has caused damage to the outer net, the inner net, and the hard layer with threat effects of kinetic energy, impact force, overpressure, and fragmentation.

The risk is low at negligible severity level under seldom on the frequency/probability scale because the UAS remains intact and the UAS impact has caused damage to the outer net with threat effects of kinetic energy and impact force. The risk is low at negligible severity level under unlikely on the frequency/probability scale because the UAS remains intact and the UAS impact has caused damage to the outer net and the inner net with threat effects of kinetic energy and impact force. The risk is low at negligible severity level under likely on the frequency/probability scale because there is no UAS detonation and the UAS impact has caused damage to the outer net with threat effects of kinetic energy and impact force.

The use of a hard layer and a plurality of nets delivers the maximum protection of the asset at a minimum cost in general. Increasing distance to detonation decreases the TBI (Traumatic Brain Injury) occurrence and risk.

In sum, the multilayered asset protection system should eliminate or mitigate each of the four threats of kinetic energy, impact force, overpressure, and fragmentation. The design should provide the highest protection at the lowest cost and achieve an acceptable risk tolerance.

FIG. 12 shows an example of protection scenarios for the threat of kinetic energy as part of the risk analysis. FIG. 13 shows an example of protection scenarios for the threat of impact force as part of the risk analysis. FIG. 14 shows an example of protection scenarios for the threat of overpressure as part of the risk analysis. FIG. 15 shows an example of protection scenarios for the threat of fragmentation as part of the risk analysis. For each threat, the threat response measure involves utilizing two net layers ($1) or utilizing two net layers plus one hard layer (5 inches of concrete) ($2) at reasonable costs. Additional protection at much higher costs include utilizing one extra heavy layer (12 inches of concrete) ($6) to absorb the threat, utilizing one or more net layers plus multiple extra heavy layers (12 inches and 24 inches of concrete) ($9), or utilizing a blast resistant robust structure as new construction.

The kinetic energy represents the threat energy from motion. Preventing contact with the asset is prudent. Capturing the incoming objects eliminates the threat factor. Disintegration lessens the threat factor. The impact force represents the threat of piece(s) impacting asset. Preventing contact with the asset is prudent. Keeping the impact pieces small limits the damage potential. Overpressure represents the blast wave imparting a force on the asset. Increasing the distance of detonation from the asset is prudent. Fragmentation represents the threat of detonation byproducts impacting the asset. Preventing contact with the asset is prudent.

FIG. 16 shows an example of extremely high risk for an UAS no capture with detonation. The detonation location is at the asset. The UAS is disintegrated. Threats to the asset include kinetic energy, impact force, overpressure, and fragmentation. The damage level is complete destruction.

FIG. 17 shows an example of high risk for an UAS impact no detonation. The impact location is at the asset. Threats to the asset include kinetic energy and impact force. The UAS is intact. The damage level is loss of use.

FIG. 18 shows an example of low risk for a no detonation intact UAS capture. The capture location is at the outer layer. The UAS is intact. The damage level is none since sufficient inherent protection exists.

FIG. 19 shows an example of low risk for a no detonation intact UAS capture. The capture location is at the inner layer. The UAS is intact. The damage level is none since sufficient inherent protection exists.

FIG. 20 shows an example of low risk for a no detonation disintegrated UAS capture. The capture location is at the outer layer. The UAS is disintegrated. Threats to the asset include kinetic energy and impact force. The damage level is none since sufficient inherent protection exists.

FIG. 21 shows an example of moderate risk for a no detonation disintegrated UAS capture. The capture location is at the inner layer. The UAS is disintegrated. Threats to the asset include kinetic energy and impact force. The damage level is none since sufficient inherent protection exists.

FIG. 22 shows an example of low risk for a no detonation disintegrated UAS impact. The capture location is at the hard layer. The UAS is disintegrated. Threats to the asset include kinetic energy and impact force. The damage level is none since sufficient inherent protection exists.

FIG. 23 shows an example of moderate risk for a detonation disintegrated UAS. The detonation location is at the outer layer. The UAS is disintegrated. Threats to the asset include kinetic energy, impact force, overpressure, and fragmentation. The damage level is none since sufficient inherent protection exists.

FIG. 24 shows an example of moderate risk for a detonation disintegrated UAS. The detonation location is at the inner layer. The UAS is disintegrated. Threats to the asset include kinetic energy, impact force, overpressure, and fragmentation. The damage level is none since sufficient inherent protection exists.

FIG. 25 shows an example of low risk for a detonation disintegrated UAS. The detonation location is at the hard layer. The UAS is disintegrated. Threats to the asset include kinetic energy, impact force, overpressure, and fragmentation. The damage level is critical.

6. Conclusions

A multilayer system has been developed for protecting an asset from UAS drone attacks. In one embodiment, the system includes an outer tension based primary mesh member, at least two separated, structurally independent layers of netting (e.g., first or inner net and second or outer net) supported to be laterally interconnected rigid columns with controlled stiffness elements (coil springs) attached the top of each column, and a hard layer forming a rigid hardened structure enclosing the asset.

There are significant commercial applications to protect various assets from UAS attacks. These assets include, for instance, electrical transformers, munition storage, living quarters, gas production equipment, vehicles, and satellite equipment in unstable areas of the world.

The inventive concepts taught by way of the examples discussed above are amenable to modification, rearrangement, and embodiment in several ways. Accordingly, although the present disclosure has been described with reference to specific embodiments and examples, persons skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the disclosure.

An interpretation under 35 U.S.C. § 112(f) is desired only where this description and/or the claims use specific terminology historically recognized to invoke the benefit of interpretation, such as “means,” and the structure corresponding to a recited function, to include the equivalents thereof, as permitted to the fullest extent of the law and this written description, may include the disclosure, the accompanying claims, and the drawings, as they would be understood by one of skill in the art.

To the extent the subject matter has been described in language specific to structural features and/or methodological steps, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or steps described. Rather, the specific features and steps are disclosed as example forms of implementing the claimed subject matter. To the extent headings are used, they are provided for the convenience of the reader and are not to be taken as limiting or restricting the systems, techniques, approaches, methods, devices to those appearing in any section. Rather, the teachings and disclosures herein can be combined, rearranged, with other portions of this disclosure and the knowledge of one of ordinary skill in the art. It is the intention of this disclosure to encompass and include such variation.

The indication of any elements or steps as “optional” does not indicate that all other or any other elements or steps are mandatory. The claims define the invention and form part of the specification. Limitations from the written description are not to be read into the claims.

Unless explicitly stated otherwise, each numerical value and range should be interpreted as being approximate as if the word “about” or “approximately” preceded the value or range.

Unless otherwise indicated, all numbers expressing quantities of ingredients, properties such as molecular weight, percent, ratio, reaction conditions, and so forth used in the specification and claims are to be understood as being modified in all instances by the term “about,” whether or not the term “about” is present. Accordingly, unless indicated to the contrary, the numerical parameters set forth in the specification and claims are approximations that may vary depending upon the desired properties sought to be obtained by the present disclosure. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the disclosure are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements.

It will be further understood that various changes in the details, materials, and arrangements of the parts which have been described and illustrated in order to explain embodiments of this invention may be made by those skilled in the art without departing from embodiments of the invention encompassed by the following claims.

In this specification including any claims, the term “each” may be used to refer to one or more specified characteristics of a plurality of previously recited elements or steps. When used with the open-ended term “comprising,” the recitation of the term “each” does not exclude additional, unrecited elements or steps. Thus, it will be understood that an apparatus may have additional, unrecited elements and a method may have additional, unrecited steps, where the additional, unrecited elements or steps do not have the one or more specified characteristics.

It should be understood that the steps of the exemplary methods set forth herein are not necessarily required to be performed in the order described, and the order of the steps of such methods should be understood to be merely exemplary. Likewise, additional steps may be included in such methods, and certain steps may be omitted or combined, in methods consistent with various embodiments of the invention.

Although the elements in the following method claims, if any, are recited in a particular sequence with corresponding labeling, unless the claim recitations otherwise imply a particular sequence for implementing some or all of those elements, those elements are not necessarily intended to be limited to being implemented in that particular sequence.

All documents mentioned herein are hereby incorporated by reference in their entirety or alternatively to provide the disclosure for which they were specifically relied upon.

Reference herein to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the invention. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments necessarily mutually exclusive of other embodiments. The same applies to the term “implementation.”

The embodiments covered by the claims in this application are limited to embodiments that (1) are enabled by this specification and (2) correspond to statutory subject matter. Non-enabled embodiments and embodiments that correspond to non-statutory subject matter are explicitly disclaimed even if they fall within the scope of the claims.