Mechanical & Fluid Systems

Controlling the EMI Effects of Avionic Equipment

Devices that can cause interference in aircraft include laptops, tablets, and cell phones, and all have been suspected of causing events such as autopilot disconnects, erratic flight deck indications, and airplanes turning off course. Board level shielding has never been more important in maintaining the functionality and safety of avionic equipment.

Posted in: White Papers, White Papers

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Force Transfer Machines

There has been ongoing debate as to whether or not a hydraulic force machine that applies the force simultaneously to both the reference standard and the unit under test is more repeatable and reproducible when the force is applied and transferred with 3 bars versus 2 bars. The debate centers around alignment of the reference standard and the unit under test. There is no disagreement about the benefits of using a triangular configuration when using multiple load cells to weigh an object; however, there is a debate over any advantages that might be offered by using a 3 bar Universal Calibrating Machine (UCM) instead of a traditional 2 bar system. This paper provides test results for repeatability and reproducibility for a 2 bar UCM and a 3 bar UCM, showing the null hypothesis to be correct and proving that there is not a difference between either type of UCM.

Posted in: White Papers

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Driving Auto Performance Through Lubricant Selection

Underhood temperatures are gradually rising as aerodynamics dictate tighter packaging and large engines are being replaced by smaller turbocharged and supercharged engines for improved fuel efficiency. With ambient temperatures under the hood exceeding 120 °C (248 °F), finding a lubricant that can withstand the high temperatures for an extended period of time is key.

Posted in: White Papers, Coatings & Adhesives

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Unique Method for Orifice Production

To produce accurate, repeatable orifices, all the variables that might influence the Cd Value (Coefficient of Discharge) must be controlled during production. This includes the orifice hole length, edges, surface finishes, roundness and the elimination of all tool marks, burrs, ragged edges and irregularities. If any one of these areas is not perfectly managed, the orifice flow rates will vary from piece to piece thereby making it impossible to predict flow with any accuracy.

Posted in: Mechanics, White Papers, White Papers

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Minimum Incremental Motion and Holding Stability in Beamline Positioning

Many beamline applications such as X-ray microscopy and Computed Tomography (CT) require positioning of samples, detectors, and optics in order to perform measurements. Microscopy applications often require imaging of the structure of matter at the sub-micrometer and even nanometer level. Good holding stability, both short-term and long-term, is required because movement of the sample or optics over the time of measurement will cause poor images. Also, the ability to make small mechanical movements on the order of nanometers is often critical for alignment and adjustment of samples or optics.

Posted in: White Papers

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Use Metal Bellows To Replace Springs

Servometer metal bellows are utilized for metallic hermetic seals, volume compensators, pressure and temperature sensors, flexible connectors, and countless other applications where quality, dependability, and long life are critical requirements. In this whitepaper, we evaluate the use of an electrodeposited metal bellows as a replacement for a metal spring in mechanical and electrical systems. The bellows offers various benefits to create a cost-effective repeatable solution.

Posted in: White Papers

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Nonlinear Model Predictive Control

This whitepaper presents an automatic workflow for implementing Model Predictive Control (MPC) controllers. The process uses MapleSim to generate a model of the system, whose dynamic equations are then extracted using Maple. Next, Maple is used to formulate the MPC problem, and generate the solver, which it automatically converts into the C code of the MPC controller. The advantage of using Maple is that the required procedures and their corresponding derivatives are computed and optimized whenever there is a change in the dynamic equations. The use of Maple saves time, removes human error, and produces highly optimized controller code.

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