Visualization of geospatially correct, remotely sensed data is a key element of many government and commercial applications. It enables a user to analyze and assess ground activities and other conditions of interest. Because remotely sensed data can include a diversity of data types reflecting many different data formats, users may experience difficulty visualizing and interpreting these varying data types and formats due to data structure complexity. In addition, important supplemental information often accompanies the data. This supplemental information—or metadata— may include pertinent information of significant value to the user with respect to where, when, and how data collection occurred. Whereas some applications require metadata to support geospatial analysis functions such as positioning and measurement, many others are unable to interpret such metadata and it may thus go unnoticed. Multiband data and motion imagery further compound the task of visualization with spectral components and complex video streams interlaced with other geospatial information.

Posted in: Briefs, Software, Data acquisition and handling, Imaging

New Capability to Characterize the Mechanical Properties of Explosive Materials

Improved targeting accuracy and the long-standing desire to minimize collateral damage are causing current and future munitions to become much smaller. As munitions size decreases, the explosive materials packed within bomb cases begin to carry a significant portion of the structural loads experienced by the warhead. In an ongoing program effort to determine the mechanical properties of explosives and other energetic materials, scientists at AFRL's High Explosives Research and Development (HERD) facility (Eglin Air Force Base, Florida) acquired a miniaturized split Hopkinson pressure bar (MSHPB) (see Figure 1). Designed and built by Mr. Clive Siviour under the guidance of Drs. John Field, Bill Proud, and Stephen Walley (of the United Kingdom's University of Cambridge, Physics and Chemistry of Solids Group), the MSHPB is capable of strain rates up to 105 s-1 in material samples. AFRL's European Office of Aerospace Research and Development sponsored the project.

Posted in: Briefs, Materials, Materials properties, Hazardous materials

Ceramic Matrix Composites Research

AFRL scientists characterized and evaluated the high-temperature mechanical behavior of fiber-reinforced ceramic matrix composite (CMC) materials used in aerospace structural applications. Researchers examined four principal characteristics of a porous matrix composite that General Electric developed for the aerospace industry. Their evaluations resulted in an increased understanding of the materials and their potential for applications in military and commercial aerospace products.

Posted in: Briefs, Materials, Research and development, Ceramics, Composite materials

Characterizing Mechanical Properties at the Microscale

Scientists from AFRL, Pratt & Whitney Aircraft, and General Electric Aircraft Engines, working under the Defense Advanced Research Projects Agency's Accelerated Insertion of Materials (AIM) program, have invented a new method for characterizing the single-crystal properties of aerospace alloys using micron-size test samples. The research team based the new characterization method on focused ion beam (FIB) microscopy and a commercially available nanoindentation-based test instrument. Further development of these methodologies, in conjunction with their continued integration with simulation methods devised under the AIM program, will enable engineers to consider local changes in material microstructure and their effect on properties in the design process. The integration of advanced mechanical property measurements, materials representation, and simulation methods will dramatically decrease the time required for new materials insertion and will transform microstructure into a design variable for engineered systems. These advancements will directly benefit combat systems and readiness.

A deformed single crystal of pure nickel after measurement of critical resolved shear stress under single-slip conditionsA primary challenge to the rapid insertion of new materials into the design cycle is the need to understand both the intrinsic properties of an engineering material at the microscopic level and the influence of defects on these properties at the macroscopic level. Historically, scientists have been unable to develop model parameters or validate continuum materials behavior models that are based upon discrete microstructural information. Continuum crystal plasticity models are at the frontier of techniques that incorporate direct microstructural information. However, a major deficiency of these models is the need to obtain required input information: the single-crystal mechanical properties of individual grains, or microconstituents. Acquiring this information is particularly difficult when such parameters must reflect the subtleties of material process history or the local influence of material defects.

Under the AIM program, AFRL researchers have sought to measure the single-crystal mechanical properties, such as the critical resolved shear stresses and strain hardening rates, of micro- and nanoscale samples extracted from relevantly processed structural alloys (see figure). Scientists are currently developing direct methods to automatically and rapidly characterize both the mechanical response of relevant microstructural elements and the stochastic nature of material property variation to establish the mechanical properties of a material's representative volume elements (RVE).

It is essential for scientists building continuum models to quickly determine the mechanical properties of RVEs in order to quantify the inherent variability in material properties, the observed variability in experimental measurements, and the uncertainty in predicted properties. They can then establish "confidence metrics" for the data they incorporate into the designer's knowledge base. Without such confidence, scientists can add new materials (or old materials in new applications) to the knowledge base only after extremely difficult and costly testing.

The new characterization method uses FIB milling to isolate and prepare single-crystal mechanical test specimens from individual grains, or precipitates, of a conventionally processed alloy. Scientists then move the prepared specimens to a conventional nanoindenter device outfitted with a flatpunch indentation tip. The nanoindenter imposes uniaxial compression on the microsamples and records highfidelity load-displacement measurements as the samples deform. With the development of this novel mechanical behavior test capability, researchers now envisage sampling the local mechanical effects of material microstructure and statistically incorporating these results in improved constitutive response surfaces, which could be used in simulations of critical component features.

Dr. Dennis M. Dimiduk, Dr. Michael D. Uchic, and Dr. Peter S. Meltzer (Anteon Corporation), of the Air Force Research Laboratory's Materials and Manufacturing Directorate, wrote this article. For more information, contact TECH CONNECT at (800) 203-6451 or place a request at http://www.afrl.af.mil/techconn/index.htm. Reference document ML-H-04-10.

Posted in: Briefs, Materials

Current Loop Controller (CLC) Eases Industrial Automation Retrofits

Micronor Inc.’s (Newbury Park, CA) MR267 Current Loop Controller (CLC) option remotely controls a motorized potentiometer and/or rotary cam switch via current, voltage input, or external potentiometer.

Posted in: Products, Products, Electronics & Computers

Hardware Debug Software Adds 64-bit JTAG, Flash Support

Macraigor Systems LLC (Brookline, MA) has added JTAG debug and Flash memory programming support for several Freescale PowerPC and MIPS processor support, in addition to existing ARM microprocessor support to its OCDemon debug suite.

Full JTAG debug and Flash programming support has been added for the Freescale MPC5200 rev. B processor and the Freescale 83xx PowerQUICC II Pro family of processors. Flash programming capabilities also have been expanded to include the Freescale MPC5500 and MAC71xx families of processors, as well as MIPS 5Kc-based, 64-bit processors, including the Phillips PR1900, Toshiba TX49, and Broadcom BCM1250 and BCM1125 processors. The Flash programmer is supported under Windows 98/ME, NT, 2000, and XP operating systems, as well as under Red Hat Linux versions 7.2 and 9.0. The software may work with other operating systems and versions, but has not been verified against such and is not guaranteed to work.

Macraigor also has added support for these processors to its pre-built GNU tools suite, including sample configurations for standard evaluation boards. These examples contain source, gdbinit, and make files for each board. The included demo program allows developers to easily build, download, and debug a small application via gdb. Macraigor’s JTAG interface devices are immediately available for the ARM7, ARM9, ARM11, and Intel XScale processor families. Fully installable versions of the GNU toolkits for both Windows and Linux are immediately available. These include demo programs allowing the end-user to be up and running within minutes of the installation.

Also available is a version of OCDRemote, allowing users to use other versions of the GNU toolset with Macraigor’s hardware. GCC, the GNU Compiler Collection, includes front ends for C and C++ ARM compilers. The GNU Assembler, part of the GNU Tools software suite, is the assembler used to convert ARM assembly language source code into binary object files.

Other recent additions to OCDemon’s supported processor list include the AMCC PowerPC 440GP, 440EP, and 440GX processors. Macraigor has also updated their GNU tools suite to include example configurations for the AMCC Bamboo, Yosemite, Ebony, and Ocotea evaluation boards. Other recent additions include AMD Geode low-voltage NX processor and Freescale i.MX31 and i.MX31L multimedia application processors.

The OCDemon family of debug tools is immediately available for the listed processors and functions. OCD Commander, an assembly-level software debugger, and OCD Remote, the GNU tools suite, are available at no charge from the Macraigor Web site.

For Free Info Visit http://info.ims.ca/5655-404

Posted in: Products, Products, Electronics & Computers

USB Digital I/O Board Enables High-Speed Digital Monitoring and Control

ACCES I/O Products (San Diego, CA) offers the Model USB-IIRO-16, featuring 16 Form C (SPDT) electromechanical relays and 16 optically isolated digital inputs. The board is designed to meet the needs of industrial systems monitoring and control. The industrial I/O market commonly uses electromechanical Form C relays due to their robustness and ability to withstand unexpected surge currents, allowing for increased flexibility in switching capability. These relays also are used where small reed relays are inadequate due to their susceptibility to contact damage.

Posted in: Products, Products, Electronics & Computers

PLL/Synthesizer Includes VCO

Crystek Corporation’s (Fort Myers, FL) CPLL66 family is the company’s first foray into the PLL/Synthesizer market. Designed for digital radio equipment, fixed wireless access, satellite communications systems, base stations, personal communications systems, portable radios, and test instruments, the CPLL66 is a complete PLL/ Synthesizer that only needs an external frequency reference and supply voltages to operate the internal PLL (phase lock loop) and VCO (voltage controlled oscillator).

Posted in: Products, Products, Electronics & Computers

A Software Development Process for Small-Scale Embedded Systems

Developing software for small-scale embedded applications is different from developing large-scale software applications. Large-scale applications use commercially available ‘one fits all’ software development solutions that are difficult to scale downward and usually miss the desired process goals. In many cases, developing a small-scale software application development process within an existing corporate environment is quicker, less expensive, and results in superior developer productivity and product quality.

Posted in: Articles, Articles, Embedded Technology, Board-Level Electronics, Electronics & Computers, Software, Embedded software, Product development

Choosing Among ZigBee RF Power Options for Your Wireless Application

While often associated with home automation, the new ZigBee wireless data standard is making fast inroads into industrial, military, and aerospace applications. By supplying highly reliable, wireless mesh networking at very low cost, ZigBee enables improvements to traditional sensing and monitoring applications, and enables new applications that would otherwise be impractical.

Posted in: Articles, Articles, Electronics & Computers, Power electronics, Wireless communication systems