Secure Partitioning Safeguards Real-time Performance

High performance multi-core processors are providing opportunities to consolidate multiple applications into a single system. However, embedded applications often have real-time requirements that cannot be put in jeopardy by other software clamoring for the same system resources such as CPU cycles and memory.

Posted in: Articles, Articles, Electronics & Computers, Architecture, Computer software / hardware, Reliability

Visualization Tools Aid Multi-core Development

Multi-core processing is a "disruptive technology", transforming the way embedded systems are architected, developed, and debugged. With greatly improved performance and lower power, multi-core processors have caught the attention of designers who don't think twice about putting two, four, or even eight processor cores into a system. But many software developers are playing catch up, working hard to quickly parallelize code. They are finding traditional debug methods aren't sufficient to profile the complex interactions between concurrently running tasks. "In a system with interacting applications running simultaneously on multiple processor cores, breakpoints have reduced applicability as a tool for understanding system behavior," says Rob McCammon, Director of Advanced Technology Planning at Wind River Systems.

Posted in: Articles, Articles, Electronics & Computers, Design processes, Architecture, Embedded software, Displays

Solid-State Viscosity Sensors For Military and Aerospace Applications

Embedded OEM application markets such as the military and aerospace industries are experiencing a growing demand for sensors that provide instantaneous and continuous process control and machine health information. For a large segment of these industries, fluid viscosity is the key physical parameter that can assist in final process control and machine diagnostics. To that end, it is imperative that a solid-state chip be cost-effective and provide the functionality and scalability that is demanded.

Posted in: Briefs, Physical Sciences, Sensors and actuators

Self-Lubrication of Hot YSZ-Ag-Mo Nanocomposite Coatings

An experimental study has been performed to learn about the physical and chemical mechanisms of self-lubrication of coatings that comprise nanostructured composites of yttria-stabilized zirconia (YSZ), silver, and molybdenum. These and other YSZ-based nanocomposite coatings have received increasing attention in recent years because they offer a combination of hardness, toughness, resistance to wear, and low-friction C properties that make them attractive for reducing wear and friction and increasing the lifetimes of hot, sliding components of mechanical systems. In addition to the excellent mechanical and thermal stability of the basic YSZ ceramic material, the nanocomposite structures of these coatings, consisting of combinations of amorphous and crystalline phases, provide a “chameleon” surface adaptation, in which different phases turn into lubricants in response to different test environments, contact loads, sliding speeds, and temperatures. Moreover, proper sizing of nanocrystalline grains can restrict crack sizes and create large volumes of grain boundaries, thereby increasing the toughness and contact-load-bearing capabilities of these coatings.

Posted in: Briefs, Materials, Lubricants, Coatings Colorants and Finishes, Composite materials, Nanomaterials, Wear

Autonomous Vehicles Would Learn by Mimicking Human Drivers

A program initiated by the Defense Advanced Research Projects Agency (DARPA) and now also pursued by other agencies called “Learning Applied to Ground Robots” (LAGR), is developing control algorithms that would enable a robotic land vehicle, robotic underwater crawler, or other similar autonomous mobile robot to traverse terrain safely. Among the algorithms needed are navigation algorithms for finding and then following a safe path across terrain from a starting or current position to a destination.

Posted in: Briefs, Information Technology, Vehicle drivers, Robotics, Autonomous vehicles

Advances in Algorithms for CFD and Finite-Element Simulation

A program of research and development has resulted in some advances in algorithms for computational fluid dynamics (CFD), finite-element simulation of solid objects undergoing large deformations, and some related topics. The main advances are summarized as follows:

Posted in: Briefs, Information Technology, Computational fluid dynamics, Finite element analysis

Shape-Based Recognition of 3D Objects in 2D Images

An object-recognition algorithm analyzes data from two-dimensional (2D) images to locate and identify possibly complexly shaped three-dimensional (3D) objects in possibly highly cluttered scenes depicted in the images. More specifically, the algorithm implements a relatively simple, effective, and fast process for recognizing 2D objects that may be partly occluded and that have shapes that can be modeled by use of sets of line segments (see figure). Because the algorithm tolerates a fair amount of perspective distortion, it is also applicable to 3D objects represented by sets of viewpoint- dependent 2D models.

Posted in: Briefs, Information Technology, Mathematical models, Imaging

Hybrid Three-Axis Vibration Reducers

Hybrid (passive/active) devices have been developed to reduce the magnitudes of possibly threedimensional vibrations coupled from vibrating equipment on platforms to bases that support the platforms. These hybrid devices are three-axis generalizations of singleaxis hybrid vibration reducers developed and reported previously. Each hybrid device includes rubber passive vibration-isolator pads, piezoelectric actuators, optional piezoelectric force sensors, and accelerometers. Each device operates in conjunction with a computer and control-and-actuation circuitry, which process accelerometer readings using feedforward and/or feedback control laws to excite the piezoelectric actuators with signals having amplitudes and phases chosen to minimize acceleration of the base.

Posted in: Briefs, Mechanical Components, Vibration

Some Advances in Reducing Drag and Suppressing Convection

Theoretical and computational research has yielded some advances in the art of designing active feedforward and feedback controllers to suppress thermal convection and reduce drag (by suppressing turbulence) in boundary-layer flows. The advances include (1) improved means for designing reduced-order (and, hence, computationally more efficient) controllers and (2) discovery of a previously unknown phenomenon that could be exploited for feedforward control to reduce drag.

Posted in: Briefs, Mechanical Components, Electronic control systems, Drag

Dense Functionalized-Nanowire Biosensor Arrays

Progress has been made in the development of compact sensor arrays containing molecular electronic devices for detecting molecules of interest (especially biomolecules) with high sensitivity and selectivity. As described in somewhat more detail below, the sensory devices in these arrays are based on chemically functionalized semiconductor nanowires. Because of the small sizes of nanowire-based devices, these arrays could be extremely dense, enabling simultaneous detection of multiple molecular species of interest. In addition, in some cases, it should be possible to extend the limits of detectability to quantities as small as a single molecule.

Posted in: Briefs, Electronics & Computers, Semiconductor devices, Sensors and actuators