Articles

Optimizing Finite Element Material Models in a Crash Test Dummy

Finite element representations of crash test dummies are widely used in the simulation of vehicle safety systems. The biofidelity of such models is strongly dependent on the accurate representation of the nonlinear behavior of the constituent rubber, plastic, and foam materials. Advanced material models are often needed to capture the dynamic response of the various parts of the dummy. The process of calibrating a finite element material model is resource-intensive, as it involves optimizing model parameters to achieve good correlation with test data under different loading conditions and rates.

Posted in: Articles, Test & Measurement, Calibration, Finite element analysis, Optimization, Anthropometric test devices
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The Evolution of AdvancedTCA How Far Has It Come?

AdvancedTCA (ATCA) continues to evolve to meet not just the market demands for the telecom central office, but networking, data center, medical, and military communications applications. The two main goals that ATCA suppliers have been trying to solve often conflict with each other: offering more performance in less space, while meeting the specific market and compliance requirements for each industry.

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Designing CompactPCI Systems with Serial Interfaces

With more than a year under its belt since it was officially ratified by PICMG in March of 2011, CompactPCI Serial (PICMG CPCI-S.0) has proven to be a good example of how an industry standard can be upgraded to meet the needs of evolving computing parameters while protecting the historical investments tied to the original architecture. The fact that it has found a new home in a wider variety of application environments is just one more benefit that this new computing standard offers.
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New Standards Allow More CPU Options in Embedded Computing

Embedded system designers often find themselves trapped by CPU design choices they made years earlier, since switching costs can be astronomical. Hardware development often involves processor-specific interface chips and board design. Software switching costs can be even more onerous, since CPU architectures drive the purchase of development tools and the requirement for customized software. However, a couple of industry trends have opened up the CPU platform, and system designers are gaining the ability to mix and match CPU suppliers or even change CPU instruction sets to optimize products across a wider range of applications.
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Reducing Machine Controller Design and Deployment

Machine design and deployment requires integration of various technologies such as controls, mechanics, vision, lasers, data acquisition, and software, to mention only a few. These mechatronic solutions usually target a specific purpose such as part manufacturing, marking, packaging, etc. Often the controller is a key focus in the design because it must connect and coordinate all of the processes on the machine. Using separate programmable logic controllers (PLCs) and motion controllers necessitates integration, which is costly and time-consuming. Using a single controller for the machine eliminates the need for integration and shortens design and deployment time and cost.

Posted in: Articles, Motion Control, Computer software and hardware, Automation
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The Engineering of IndyCar Racing

IndyCar racing features some of the most technologically sophisticated automobiles in the world today. Weighing just 1,565 pounds and powered by single- or twin-turbocharged 2.2L V6 engines that produce anywhere from 550 to 700 HP, the sleek, aerodynamic vehicles are capable of speeds in excess of 220 mph.

Not surprisingly, all of the space-age technology used in modern IndyCars tends to attract high-tech companies to the sport. Two such companies – Mouser Electronics and Littelfuse – have joined forces this year with the KV Racing Technology team. The team’s chief technology director, Eric Cowdin, spoke with Tech Briefs Media Group editor Bruce A. Bennett to answer some typical questions an engineer might ask.

NASA Tech Briefs: How big a role does electronics play in an IndyCar?

Eric Cowdin: Electronics are actually the backbone of running an IndyCar — everything from the engine management to the data acquisition system. It’s really the basis of controlling everything that’s going on in the IndyCar, as well as feeding us information back to make it perform better. Because of all the electronics on the car, there’s a very important circuit protection system on our car: the PDU, or power distribution unit. That PDU has eight outputs and each one has a pre-set current on it. Each one of those outputs is designed specifically to the electronic system that it’s providing control to, or current to, and that PDU protects every one of those delicate circuits. The other thing that allows us to do is monitor that output, via telemetry or recorded data, which gives us a chance to help the driver avoid a serious problem.

Posted in: Articles, Automotive, Systems engineering, Racing engines, Racing vehicles
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Ensuring Safe Operation and Accurate Characterization of Laser Diodes

Laser diodes are very sensitive to electrostatic discharge (ESD), current/ voltage transients, and temperature changes, and extra care must be taken to ensure the laser diode is protected during all operating conditions. Unlike general-purpose power supplies or current supplies, laser diode drivers, mounts, and cables greatly improve the protection of laser diodes and allow low noise operation. A temperature controller helps stabilize the temperature of the laser diode packages, which provides for safe operation and wavelength stability of the laser. For fast and reliable characterization, an optical power meter and integrating sphere-based photodiode detectors are often employed where a good understanding of optical measurements is required.

Posted in: Articles, Features, Photonics, Lasers, Optics, Thermal management, Mountings
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Think Outside the Chip: MEMS-Based Systems Solutions

MEMS is an acronym for Microelectro mechanical Systems; however, most MEMS implementations to date have not been systems at all, but rather devices. This article reports the constituents and some applications of what is defined as MEMS-based systems solutions, or MBSS. In Europe, this concept is commonly referred to as ”Smart Systems In tegration.” These MBSS use front-end MEMS devices — either one or a combination of many sensors, actuators, and/or structures — that work in conjunction with several other devices including signal conditioning commonly using application specific integrated circuits (ASICs), digital signal processing (DSP) with embedded microcontrollers and software, energy creation and storage, and networking communications functions.

Posted in: Articles, MEMs, Microelectromechanical devices, Sensors and actuators
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LED Binning Using a Single Pulse Tester

LEDs are considered to be the light technology of the future due to their low energy consumption and long lifetime compared to traditional light sources. As LED luminous intensity levels increase, the range of applications for LEDs expands as well.

Posted in: Articles, Lighting, Materials & Packaging, Test & Inspection
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How Substrate Materials Affect LED Reliability

The solid-state lighting industry continues to develop LEDs with higher lumens per watt, in alignment with Haitz Law, which states that the cost per lumen falls by a factor of 10 every decade and the amount of light generated per LED increases by a factor of 20. These advancements are driving the need for packaging and thermal substrate technologies that deliver better thermal management, are more reliable, and are cost-efficient.

Posted in: Articles, Lighting, Materials & Packaging, Test & Inspection
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