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Sensors Provide Early Diagnosis Of Microcracks In Aircraft |
 Today's aircraft are in service virtually around the clock and must operate reliably and safely at all times. An active sensor system helps to detect concealed fatigue cracks in aircraft bodies, thus reducing maintenance times considerably.
If a tiny crack in the hull of an aircraft remains undetected for a long time, it can easily spread and put passengers’ lives at risk. Each component is therefore subject to international maintenance regulations: Aircraft bodies must be thoroughly inspected every 15 to 18 months, depending on the type of plane. This often requires the technicians to dismantle an aircraft’s interior lining – an expensive and time-consuming process involving several days of downtime in the hangar. Researchers at the Fraunhofer Institute for Structural Durability and System Reliability LBF in Darmstadt are developing a sensor system that allows engineers to continuously monitor the condition of their aircraft and detect any damage at an early stage.
The system is based on piezoceramic sensors that are attached to the aircraft body in a network pattern. What is special about these sensors is that they start to oscillate when a voltage is applied to them – and when they are subjected to pressure, they generate voltage. The scientists make use of both effects: While the piezo foils cause part of the hull to oscillate, the others measure the component’s response to this stimulation. “We investigated the oscillation behavior of damaged struts and rivets in an aircraft body and compared it with that of intact parts,” explains LBF project manager Dirk Mayer. “If a component is defective, it oscillates at a different frequency from one that is intact when stimulated by the piezoceramics – just as a cracked glass sounds different from an undamaged one when you tap it with your fingernail.” In this way, the researchers can accurately track down faults and monitor their development – be it fatigue cracks in the hull and wings, or rivets and other joining parts coming loose. This form of observation is also referred to as ‘structural health monitoring’ (SHM).
“With the help of this system, any damage behind the lining or in difficult-to-reach places can be identified quickly and easily, thus reducing maintenance times and inspection costs,” says Mayer. The researchers have already performed tests on a hull component in the laboratory, and are now implementing the new technology with standardized piezo and electronic components. The system will then also be suitable for use in vehicle manufacture or engine and plant construction.
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Dear Editor,
I hope you can help me or at least point me in the right direction. My neighbor just put up a huge CB Radio antennea, the thing is higher that the roof of his home, the problem is, now I have interference through our television set speakers. We can hear him speaking although it is not too clear. How can I fix the problem so that we can watch t.v. without hearing this noise? Any help you can give me would be greatly appreciated.
Sincerly,
Donna R.
Dear Donna,
If your neighbor's transmissions are interfering with your TV, the best thing for you to do is complain to the Federal Communications Commission. The FCC investigates cases of interference and they will determine if your neighbor's transmissions contain out-of-band signals. You might also try talking to your neighbor. If his antenna is for amateur radio rather than Citizens Band, "ham" radio operators have a policy of supplying a free filter for your TV in such cases.
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ElectronicDesignNet News
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We scan the wires, web sites, blogs and news media for the most interesting and relevant information, then summarize it for you in a convenient format, organized by topic areas during the week:
You can stay on top of things without wasting your precious time sifting through lots of noise. Subscribe to our digest and receive it in your eMail, or come to our site and read it in your web browser. Digest eMail subscriptions can be managed on the Newsletters tab of the "My Settings - Edit Profile" page once you register.
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Adlink Debuts 4-Axis Stepping And Servo Motion Control Card |
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Product Showcase - Friday
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Thursday, 10 May 2007 |
Adlink Technology announced the PCI-8154, a 4-axis pulse train modularized motion control card for controlling steppers, servos, and linear motors. The PCI-8154 delivers high-frequency pulse rates of up to 6.55 MHz and features a hardware-controlled emergency stop to terminate movement in case of system malfunction, a software security protection to prevent illegal copying of custom software, and a card index switch to support multiple PCI-8154 cards in a single system....more  (0) Comments |
The Mathworks And Analog Devices Introduce Link Ffor Analog Devices VisualDSP++ |
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Product Showcase - Friday
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Wednesday, 09 May 2007 |
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The MathWorks and Analog Devices introduced Link for Analog Devices VisualDSP++, which integrates MATLAB and Simulink with the Analog Devices VisualDSP++-- integrated development and debugging software environment. Link for Analog Devices VisualDSP++, which is sold and supported by The MathWorks, lets engineers verify embedded code running on VisualDSP++ using MATLAB and generate VisualDSP++ projects from Simulink models. The tool accelerates development and verification of signal processing and control algorithms on Analog Devices processors by reducing or eliminating errors associated with hand coding. Link for Analog Devices VisualDSP++ brings Model-Based Design to engineers in the aerospace and defense, automotive, communications, and electronics industries who work with Analog Devices processors. The tool supports Analog Devices Blackfin, SHARC and TigerSHARC processor families. The same model can now be used in the four stages of Model-Based Design for embedded software development - executable specification, design with simulation, embedded code generation, and code verification - for Analog Devices processors....more (0) Comments |
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Tips And Tricks For Debugging Audio |
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Test & Measurement / Data Acquisition - Tuesday
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Wednesday, 09 May 2007 |
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Are you designing a system that involves audio? Maybe an audio product, or a product with an audio subsystem? Here are some tips and tricks that may help you. Designing audio systems and debugging audio presents some interesting challenges. Sound is ruthlessly real-time; the speaker cone will keep moving, even if your prototype isn't able to keep up with the flow of output samples required. The same is true of a microphone: the microphone diaphragm keeps moving and must be sampled often enough. If you skip one or more samples at the input or the output, then a (very loud) click or pop can result. What's more vexing, the human auditory system, which is the final judge of audio quality, is extremely sensitive, especially to unexpected sounds (or artifacts) that your implementation may introduce....more (0) Comments |
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Renesas Introduces Dual-Core 32-bit SuperH Microcontrollers |
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Product Showcase - Friday
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Wednesday, 09 May 2007 |
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Renesas Technology America announced five SuperH 32-bit microcontrollers that use multi-core technology to achieve the high levels of performance required by many embedded system applications such as consumer products, industrial equipment, and car audio and navigation systems. The SH7205 and SH7265 devices incorporate two superscalar SH2A-FPU CPU cores and a set of on-chip peripherals that includes USB, ATAPI, and image processing engine functions. When the dual-core microcontrollers are operating at their 200 MHz maximum operating frequency, each CPU delivers 480-MIPS (million instructions per second) processing performance in the Dhrystone v1.1 benchmark, and 400-MFLOPS (mega floating point number operations per second) floating-point operation performance....more (0) Comments |
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