Software Suite for a Large Defense System

A suite of software tools was developed to enable networks composed of many hundreds, thousands, or even millions of commodity computers to protect themselves against a variety of security threats. These tools include Anagram, a content-based anomaly detection (AD) tool; ASSURE, which provides automatic software self-healing; and Aeolos, a distributed intrusion detection and event correlation infrastructure.

Posted in: Briefs, Software, Computer software / hardware, Cyber security, Neural networks

Wettability Tests of Polymer Films and Fabrics

High-strength polymer materials are useful components in many multifunctional materials applications. However, because of low reactivity, their use is inhibited in many processing techniques. Polymer films and fibers possess low surface energies and need to be modified through surface activation prior to being used in composite systems where adhesive bonding is an issue. Treatment of polymer materials through plasma processing is one route to greatly increase surface reactivity. Once the surface has been plasma-modified, wettability by liquids can be examined to determine the treatment effects on the polymer material’s surface reactivity.

Posted in: Briefs, Materials, Joining, Composite materials, Fibers, Materials properties, Polymers

Using a Steering Shaping Function to Improve Human Performance in By-Wire Vehicles

Currently, there is a performance issue regarding vehicle control at higher speeds for some indirect-vision, by-wire military vehicles; that is, those vehicles in which mechanical links between the driver and control devices are replaced by electronic or computerized signals. Work has been performed to assess the current state of knowledge regarding the shaping function. The overall goal was to identify design parameters critical to improving the current by-wire implementation for military tactical vehicles, and to ultimately optimize system (i.e., human-vehicle) performance for the execution of secure mobile operations.

Posted in: Briefs, Mechanical Components, Steer-by-wire, Human machine interface (HMI), Military vehicles and equipment, Vehicle dynamics

Automated Data Acquisition for a Prognostics and Diagnostics Health Monitoring System

A highly flexible automated prognostics and diagnostics sensor module (PDSM) prototype is presently under development to be incorporated for data acquisition in a Prognostics and Diagnostics Health Monitoring System (PDHMS). PDHMS acquires, stores, and communicates data gathered from sensors that monitor essential platform components to determine its current diagnostic status. This diagnostic data is used to make reliable prognostications of remaining operational life expectancy based on a platform usage profile.

Posted in: Briefs, Electronics & Computers, Data exchange, Sensors and actuators, Diagnostics, Prognostics

Tightly Coupled INS, GPS, and Imaging Sensors for Precision Geolocation

To address the issue of poor georegistration performance for small unmanned aerial vehicles (UAVs), navigation and target-location accuracy improvements achievable by tightly integrating an image-based feature-tracking algorithm with Global Positioning System (GPS) and a consumer-grade inertial navigation system (INS) sensor are being investigated. The image-aiding algorithms add to the solution across a wide variety of terrain types, thus allowing for additional estimates of camera position and orientation in the dynamic adjustment.

Posted in: Briefs, Physical Sciences, Mathematical models, Imaging, Navigation and guidance systems, Unmanned aerial vehicles

Measurement of Transient Heat Flux and Surface Temperature Using Embedded Temperature Sensors

A report describes approximate solutions for surface temperature and heat flux for two embedded temperature sensors. The solutions were verified and the range of validity was established using several methods including comparisons with an exact analytical solution for a linear problem and a numerical calculation for a non-linear problem.

Posted in: Briefs, Physical Sciences, Mathematical models, Sensors and actuators, Thermal testing

Considerations of Aeroacoustics in Turbojet-Engine Testing

A study of the aeroacoustics of a turbojet-engine test cell has been performed as one step in the development of a computational aeroacoustics capability (CAA) that could provide guidance for the design and operation of such cells. Ground testing of turbojet engines in test cells necessarily involves very high acoustic amplitudes, often severe enough to cause damage to test-cell equipment and to engines under test. Heretofore, the acoustic responses of test cells containing energetic jets have been poorly understood and generally unpredictable. The CAA capability is intended to enable prediction of deleterious acoustic events, making it possible to design test cells and choose operating conditions to prevent damage and thereby avoid the costly interruption of test schedules.

Posted in: Briefs, Physical Sciences, Acoustics, Turbojet engines, Performance tests, Aerodynamics

Imaging and Spectral Measurements of Explosions

A document describes experiments performed to investigate rates of delivery of energy onto targets from different explosive formulations. The experiments were designed to measure relative positions of blast fireballs and leading shock fronts; determine whether different explosive formulations exhibit unique spectral signatures; determine temperatures of gases and solids near fireball surfaces; and measure rates of heating as functions of time. In the experiments, unconfined explosions were observed using time-resolved laser shadowgraphy, spectrometry integrated over the first 50 ms following initiation, time-resolved three-wavelength pyrometry, and time-resolved heat-flux measurements.

Posted in: Briefs, Physical Sciences, Measurements, Imaging, Fire, Impact tests, Thermal testing

Fabricating Biologically Inspired Artificial Haircell Sensors

As electronics packaging and equipment have decreased in size and weight, so have the potential dimensions of unmanned aircraft. Specifically, a classification of micro air vehicles (MAVs) has emerged that limits the scale of the aircraft to approximately 6" (15 cm). A project is underway aimed at developing artificial haircell flow sensors following biological inspiration of insect flow sensors, and demonstrate the potential of these sensors for controlling the flight of MAVs.

Posted in: Briefs, Manufacturing & Prototyping, Downsizing, Sensors and actuators, Biological sciences, Unmanned aerial vehicles

Sensing for Controls and Propulsion Health Management in Turbine Engines

Advances in engine performance and reliability require sensor components that operate reliably under extreme engine operating conditions (e.g., takeoff, max thrust) and in harsh environments (e.g., high temperature and radiation). The design of advanced controls and Propulsion Health Man agement (PHM) also depend on the use of components with increased susceptibility to atmospheric radiation. Current and future engine operating temperature environments that provide major challenges in sensor design for control and propulsion health management are being explored.

Posted in: Briefs, Mechanical Components, Sensors and actuators, Diagnostics, Gas turbines, Durability, Reliability