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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
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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
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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
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Polypeptide-Based Molecular Electronics

Polypeptide supramolecules that will self assemble from solution and will form molecular wires that exploit quantum mechanical transport mechanisms can enable the formation of molecular devices such as transistors, diodes, and sensors. The peptides were designed and then arranged on substrates using self-assembly, Dip-PEN nanolithography, and e-beam assisted lithography. The peptides were characterized using atomic force microscopy (AFM) and the electrical properties of the self-assembled interconnects are characterized as well. These peptides can be nanoengineered/nanoassembled individual building blocks at the molecular level to form conducting channels towards realization of molecular MOSFETs/CMOS device technology.

Posted in: Briefs, Electronics & Computers, Sensors and actuators, Transistors, Additive manufacturing, Forming, Materials properties, Semiconductors
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Photon-Counting Chirped Amplitude Modulation Ladar

This work is a follow-on to an effort to develop a method using Geiger-mode avalanche photodiode (GM-APD) photon-counting detectors in the U.S. Army Research Laboratory’s chirped amplitude modulation (AM) ladar receiver to yield sensitivities approaching the shot noise limit. Such sensitivities represent about four orders of magnitude improvement over the sensitivities of the currently used unity-gain, optoelectronic mixing (OEM) metal-semiconductor-metal (MSM) detectors. A variant of the chirped AM ladar has been experimentally assembled and tested, and new single photon-counting detector products were evaluated in terms of their benefits to the chirped AM ladar.

Posted in: Briefs, Photonics, Measurements, Radar, Semiconductor devices, Product development, Military vehicles and equipment
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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
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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
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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
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Audio Enrichment Technology

ARC International (San Jose, CA), has introduced the Virtual Bass™ audio enrichment technology that delivers a deep rich bass response on existing speakers or headphones, eliminating the need to add subwoofers or other audio components. Virtual Bass optimizes a product's bass rendering capabilities, taking into account the analog to digital converter, amplifier, speaker cavity, and speaker driver, resulting in audio that more accurately reflects the original performance without adding artificial signals or muffling voice articulation and audio clarity.

The low-power ARC® Sound Subsystem is a 100-hour audio playback solution for portable devices. When implemented on the ARC® Sound Subsystem, Virtual Bass offers a complete solution that lowers manufacturing cost while producing an enhanced listening experience. The complete solution includes an underlying silicon solution that cuts chip size and lowers power consumption, a complete set of software to provide playback of any digital music format, all the tools needed to develop the chip solution, and the complete Sonic Focus™ audio enrichment technology suite.

For Free Info Click Here.

Posted in: Products, Products, Electronics & Computers
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DSP Library

STMicroelectronics (Geneva, Switzerland) has released a new DSP library for its ARM Cortex-M3-based STM32 microcontrollers. The STM32 DSP library is license-free, royalty-free, and provides a large number of valuable functions coded in C or assembly language. These include a PID controller, Fourier transform functions, and a selection of digital filters such as 16-bit FIR, IIR direct-form, and IIR canonical-form filters. The functions are ready to use, easy to integrate, and are comprehensively documented to promote software maintainability and accelerate endproduct development. Operations such as multiply-accumulate or hardware divide can be executed within only two cycles. Demonstrations running on the STM32F103 Performance Line MCU have performed a complex 256-point 16-bit radix-4 Fast Fourier Transform (FFT) in only 362μs. Compared to alternative hybrid architectures such as digital signal controllers (DSC) with separate control- and signal-processing cores, the STM32 streamlines software development, enhances performance, and allows developers to use standard tools. The new DSP libraries can be used with the IAR, Keil, and Raisonance tool-chains for the STM32. The DSP library reduces cost and time-to-market for applications such as digital power conversion, including solar-energy projects, closed-loop control of switched-mode power supplies, audio and speech processing, and digital image processing.

For Free Info Click Here.

Posted in: Products, Products, Electronics & Computers
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