Patent Publication Number: US-10775136-B2

Title: Edge-on armor system with translating and rotating armor panels

Description:
GOVERNMENT SUPPORT CLAUSE 
     This invention was made with United States Government support under Contract No. W56HZV15C0129 funded by the Defense Advanced Research Projects Agency (DARPA). The Government has certain rights in this invention. 
    
    
     TECHNICAL FIELD OF THE INVENTION 
     This invention relates to protection of vehicles and heavy equipment from ballistic weaponry and similar projectile threats, and more particularly to an armor system that has moveable armor panels that both translate and rotate to provide edge-on protection. 
     BACKGROUND OF THE INVENTION 
     Military vehicles are commonly armored to withstand the impact of shrapnel, bullets, missiles or shells, protecting the personnel inside from enemy fire. Armored military vehicles can include tanks, aircraft and ships. 
     Civilian vehicles may also be armored. These vehicles include cars used by reporters, officials and others in conflict zones or where violent crime is common. Civilian armored cars are also routinely used by security firms to carry money or valuables to reduce the risk of robbery or the hijacking. 
     Armor may also be used to protect vehicles or other equipment from threats other than a deliberate attack. Some spacecraft are equipped with specialized armor to protect them against impacts from micrometeoroids or fragments of space junk. Modern aircraft powered by jet engines usually have the engine fitted with a sort of armor near the engine to prevent damage should parts of an engine break free. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A more complete understanding of the present embodiments and advantages thereof may be acquired by referring to the following description taken in conjunction with the accompanying drawings, in which like reference numbers indicate like features, and wherein: 
         FIG. 1  is a side view of one armor panel installed on a vehicle, and further illustrates stages of deployment. 
         FIG. 2  is a perspective view, of the armor panel of  FIG. 1 . 
         FIG. 3  illustrates the dimensions of the armor panel. 
         FIG. 4  is a side view of a pike armor panel installed on a vehicle, in a deployed position. 
         FIG. 5  is a top view of a number of pike armor panels in deployed positions. 
         FIG. 6  illustrates the mechanical track, sleds, and linkages for attaching the armor panel to a vehicle and for facilitating motion of the armor panel. 
         FIG. 7  illustrates how the armor panel system of  FIG. 6  may be actuated with an actuator comprising linear motors. 
         FIGS. 8 and 9  illustrates how the armor panel system of  FIG. 6  may be actuated by, or have its actuation assisted by, an actuator comprising a gas generator. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     As indicated in the Background, for centuries there has been a need to armor vehicles of many types, including ground vehicles, water-going vehicles, aircraft, and now spacecraft. Today&#39;s armor systems must protect again serious threats, which include kinetic energy projectiles, shaped-charge-based warheads, and explosively formed penetrators. For this type of protection, the weight of conventional armor systems can be excessive. 
     The armor system described herein may be referred to as a “movable, rotatable, edge-on panel armor system”. The thick, heavy, static armor emplacements of conventional armors are replaced with movable armor panels that can be rapidly and automatically moved into the path of a projectile to meet it edge-on, instead of through an armor&#39;s thickness. This edge-on protection increases the effective thickness of the armor that is presented to the threat. 
     The armor system has less volume and weight than a conventional “flat plate” armor system. It has been demonstrated that, for a ground vehicle, the armor system can achieve accurate deployment and position of a two-hundred-pound armor panel over a six-foot range in less than 0.4 seconds. 
     Armor Panels 
       FIG. 1  illustrates one armor panel  100  installed on a vehicle, shown as a tank,  10 . The armor panel  100  has been fully deployed to a ninety-degree rotation, and is in position to protect vehicle  10  against a projectile  11 . Although vehicle  10  is shown with only one armor panel  100 , any number of panels may be installed in various locations on the exterior surface of vehicle  100 . 
     The illustration of armor panel  100  installed on a tank is for purposes of example. The same concepts apply to armor panels installed on other types of vehicles or other mobile or stationary equipment. The equipment on which one or more armor panels is installed may be referred to herein generally as the “protected equipment”. 
     Also, the illustration of projectile  11  is for purposes of example. Armor panel  100  could be used for protection against various types of projectiles, debris, or other impingements, all referred to herein as “threats”. Specific examples of threats include kinetic energy projectiles, shaped-charge-based warheads, such as found in RPGs and anti-tank guided missiles (ATGMs), and explosively formed projectiles (EFPs). 
       FIG. 2  is a perspective view of armor panel  100 . Referring to both  FIGS. 1 and 2 , in general, each armor panel  100  will be moveably attached to an associated track  110 , which is mounted on the protected equipment  10 , and which allows translational movement of armor panel  100 . Not explicitly shown are additional mechanisms used to attach armor panel  100  to vehicle  10 , and to allow translational and rotational movement of the panel. These mechanisms are described below in connection with  FIGS. 6-9 . 
     Each armor panel  100  further has an actuator  150  and a position monitor  140 . As discussed below, various actuation devices are possible for producing rapid motion of an armor panel. Examples include electromagnetic or gas-generator actuators, as well as a combined electromechanical/gas generator actuator. In  FIG. 1 , actuator  150  is represented as a single unit, but as explained below, actuator  150  may be a system of parts, such as motors and gas generators. 
     The position monitor  140  detects the current position of the panel  100 , particularly during deployment, and provides input to actuator  150 . Position monitor  140  may have various implementations, such as fiducials on track  110  read by an encoder, or an inertial measurement unit on panel  100 . As explained below, exact “edge-on” positioning of panel  100  toward an incoming threat is not required, but with appropriate threat detection and processing, actuator  150  could be programmed to provide edge-on or near edge-on positioning of panel  100 . 
     Other input to actuator  150  includes activation signals in response to an incoming threat. It is to be understood that the armor system described herein addresses the motion and positioning of armor panels. It is assumed that the armor panels are activated in response to an appropriate sensor and analysis system, which provides real time detection of incoming projectiles and other threats and generates activation signals to actuator  150 . 
       FIG. 3  illustrates the length, thickness, and width dimensions of an example armor panel  100 . An example of panel dimensions is 3 feet in width, 2 feet in length, and 2 inches in thickness. A wide range of variation is possible. A particular vehicle or other protected equipment can have multiple panels of varying dimensions. 
     As illustrated by the arrows in  FIG. 1 , armor panel  100  moves both translationally and rotationally to intercept projectile  11  edge-on. The panel  100  moves translationally on track  110  along the surface of vehicle  10  from Position C to Position D, or to any position between and beyond. The translational movement can be vertical relative to the base of the vehicle or other equipment, as shown herein. Alternatively, the translational motion can be horizontal, or even along a diagonal. Panel  100  moves rotationally from Position A to Position B, or to any position between. Rotational movement from Position E along the translational path is shown, but the rotational movement can be from any of its translational positions between Position C and Position D. 
     Typically, the rotational movement during deployment is around ninety degrees, that is, from angular Position A to angular Position B. In its undeployed position, armor panel  100  lies flat or nearly flat against the surface of the vehicle  10  (in angular Position A), positioned along any of the translational positions from Position C to Position D. 
     For the example dimensions of  FIG. 3 , a vehicle (or other protected equipment) protected with one or more armor panels  100  can provide two feet (its length) of armor thickness (with its panel deployed rotationally to Position B) to defeat a threat. This can be compared to a conventional two-to-three-inch armor plate mounted conventionally on the exterior of a vehicle. 
     Because of the high speed of most expected threats, the armor panel  100  need only “fly through” the desired location to meet the threat. A full edge-on deployment is illustrated as Position B, but a projectile can be effectively slowed even when the armor panel is not exactly edge-on. In other words, the panel  100  does not need to be stopped and held in a specific position. When the panel is not deployed (Position A) it can provide armor protection to the vehicle for lesser threats over a larger area. Less than full edge-on protection is provided in positions between Position A and Position B. 
     Armor panel  100  can be made from various materials. Examples are monolithic metal, spaced/angled plates, ceramics, encapsulated ceramics, glasses, encapsulated glasses, and/or composite material. Existing armor panels can be re-configured for the moveable use of this description. However, as compared to conventional armor, it is expected that a thinner and/or lighter panel will provide as good or better protection. 
     Experimentation with a tungsten alloy projectile indicates that striking an armor steel panel edge-on will erode the projectile and prevent damage to protected equipment. The protection is successful for both center and off-center hits. 
       FIGS. 4 and 5  illustrate a “pike” configuration of armor panels  400  installed on a vehicle  40 . In this configuration, the width and thickness of each panel  400  are similar. 
       FIG. 4  is a side view, with one panel  400  deployed.  FIG. 5  is a top view, showing a number of panels  400  deployed. 
     As with the flat armor panels of  FIGS. 1-3 , the armor panels  400  move rotationally to point out from the vehicle  10  when deployed. When not deployed, panels  400  are folded against vehicle  10 . 
     Each panel  400  is supported and transported by an arm  401 , which is attached to vehicle  40  at one end and to panel  400  at the other. As indicated by the arrows in  FIGS. 4 and 5 , the arm  401  moves panel  400  both rotationally and translationally. 
     Armor Panel Mechanics and Actuation 
     There are several possible strategies for rapidly activating the translational and rotational motion of the armor panel. The description below is directed to the following three approaches: 1) electromechanical approach, 2) gas generator approach, and 3) combined electromechanical and gas generator approach. Each of these activation approaches can be used with similar mechanical linkages to moveably attach the armor panel to the protected equipment. 
       FIG. 6  illustrates an example of a mechanical implementation for both rotational and translational movement of an armor panel  500 . In addition to armor panel  500 , the same concepts apply to the armor panels described above. 
     A track  510  is mounted on the protected equipment, a portion of whose surface is shown. The translational movement is vertical in  FIG. 6 . Two sleds, a lower sled  520  and an upper sled  540 , move translationally along, and are guided by, track  510 . Two arms  530  connect armor panel  500  to lower sled  520 , one arm  530  on each side of armor panel  500  (along its length). Each arm  530  has pivotal connections to armor panel  500  at both ends of arm  530 , so that panel  500  can move rotationally. In the example of  FIG. 6 , the attachment of an upper end of each arm  530  is approximately at the midpoint of the side of the armor panel. At the upper corner of the armor panel, a pivotal connection is made to the upper sled  540 . 
     The two sleds  520  and  540  move independently on track  510 . Their relative spacing from each other along track  510  provides the rotational movement of armor panel  500 , via arms  530 . The closer the spacing between sleds  520  and  540 , the greater the rotation angle of the armor panel  500 . Sleds  520  and  540  are made from a lightweight and rigid material. In the example of this description, sleds  520  and  540  are plates with openings to reduce their weight. Lower sled  520  has bars  521  protruding toward armor panel  500 , against which armor panel  500  rests when not deployed. 
     In  FIG. 6 , armor panel  500  is shown in a 45-degree position, which is not an edge-on (90 degree) position, but does provide protection as described above. Linkage arms  530  allow panel to be nearly flat against surface  50  when not deployed, or to be rotated to and optionally past 90 degrees. A typical undeployed position of panel  500  is about 8 degrees, with the angle of linkage  530  providing a moment arm to start rotational motion. Other linkage designs can be used if it is desired to stow panel  500  in a flat (vertical) position against the surface of the vehicle. 
     As alternatives to the mechanical configuration of  FIG. 6 , various other mechanisms, such as linkages, rails, bearings, shafts, cables, and/or wheels, are possible. In general, each armor panel has some sort of translational track, and some sort of rotational arm(s). By “track” is meant a rail to which one or more sleds can be attached in a manner such that the sled is attached to and can move along the track. 
     Referring again to  FIG. 1 , monitor  140  provides data to actuator  150  representing the current position and/or velocity of the armor panel  500 . Various methods of ensuring that the armor panel  500  is in the correct place are possible. Examples of position monitoring devices are optical cameras, encoders on tracks and rotary wheels. Motion monitoring devices such as inertial measurement sensors, accelerometers and gyroscopes can be mounted on the armor panel. 
     For activating movement of armor panel  500 , in general, each actuation approach implements an actuator  150  that allows independent movement of upper sled  540  and lower sled  520 . Thus, actuator  150  may comprise a system of motors, or gas generators, or a combination of both. 
     One implementation of actuator  150  is an electromechanical actuator. In this case, actuator  150  comprises at least one electric motor, connected to panel  100  through mechanical linkages. The motor can be linear or rotary and can interface to the mechanism with the use of tracks, pulleys, cables, etc. Current to the motor is controlled to control the motion to ensure the armor panel  100  is in the correct place at the correct time. Batteries, flywheels, or explosive generators or other means can provide the required electrical power on the vehicle. 
       FIG. 7  illustrates how a linear electric motor actuator  150  may be used for both translation and rotation. Actuator  150  comprises two electromagnetic linear motors  61  and  62 . Each sled  520  and  540  has an associated motor. Armor panel  500  is shown in a deployed edge-on (90 degree rotation) position. 
     Motors  61  and  62  are attached to and travel along a center magnetic shaft  63 , which is parallel to track  510 . As stated above, sleds  520  and  540  move along track  510  independently. Both sleds move translationally, but not necessarily the same distance along track  510 . The relative distance between them determines the rotational position of armor panel  500 . 
     Experimentation with an electric motor actuator  150  has resulted in rotation from 8 degrees (folded down) to 110 degrees of panel  500  with three foot translational motion. This deployment was achieved in less than 0.5 seconds. Six feet of motion with 90 degrees of rotation has been achieved in 0.7 seconds. 
     Another implementation for actuator  150  is with one or more gas generators. Examples of gas generators are airbag inflators, dilute explosives, or traditional high explosives, to provide an energetic impulsive motion of the armor panel. A piston/cylinder configuration, in which the expanding gas moves a piston inside of a cylinder, can be used to provide locomotion to the armor panel through linkages, cables, or directly driving motion with gaseous exhaust. This method can be used to induce both linear and rotational motion on tracks or shafts. It is expected that each sled would have an associated gas generator. For gas generator actuator, motion can be controlled and tuned with the use of a mechanical friction braking system that slows panel rotation or translation to position it at the required location at the required time. 
     A third implementation of actuator  150  is with a combined electromechanical and gas generator approach. One or more gas generators provide an initial impulse to the armor panel, with subsequent motion and control supplied by linear electric motors similar to those of  FIG. 6 . In experimentation, with a 200 pound panel, this type of actuator achieved controlled motion of 6 feet of translational motion and 90 degrees of rotary motion in less than 0.4 seconds. 
       FIG. 8  illustrates panel  500  deployed into an edge-on position, using an actuator  150  that is a combination of a gas generator  70  and electric motors  71  and  72 . The gas assist provided by the gas generator  70  provides both rotational and upward translational movement of both sleds. The extent of which type of motion is more assisted depends on timing control of motors  71  and  72 . 
     Gas generator  70  is shown in its post-burn deployed state in  FIG. 8 , with armor panel  500  deployed.  FIG. 9  illustrates armor panel  500  in a pre-ignited undeployed state. 
     Referring to both  FIGS. 8 and 9 , gas generator  70  comprises a cylinder  70   a  and piston  70   b . In the non-exploded state of gas generator  70  piston  70   b  fits tightly inside cylinder  70   a . When gas generator  70  is triggered, piston  70   b  is rapidly and explosively pushed apart from cylinder  70   a . These two elements separate after several inches of travel. Cylinder  70   a  is attached to the bottom of track  510 , and does not move. Piston  70   b  is attached to bottom sled  520  and travels with bottom sled  520 . 
     For all implementations of actuator  150 , actuator  150  is assumed to have appropriate software and hardware to receive input regarding when to activate in response to an incoming projectile, as well as input from monitor  140 . Actuator  150  is further programmed to process this input, and to trigger actuation of armor panel  500  achieve the desired motion in the desired time. 
     Actuator  150  may be programmed to optimize the translational position, the rotational position, and the timing of movement of the armor panel. Once an incoming threat is sensed, the control parameters for moving armor panel  500  must be optimized. The control parameters optimized for one target (e.g. 6′ of translation, 90 degrees rotation, in 0.4 seconds) do not necessarily translate for other targets (e.g. 1′ translation, 90 degrees rotation, in 0.3 seconds). The target is known only moments before the armor panel must move, thus real time response is required. Simulations may be used to pre-compute optimal position/angle/time of the armor panel in response to various threats. Actuator  150  can then store look-up tables representing these optimizations, to aid in real-time activation. Similarly, for gas generator implementations, simulations can be used to determine optimal times to trigger brakes, if any, to result in a desired position/angle/time.