Tech Briefs

CryoSim

John F. Kennedy Space Center, Florida In the context of systems health management, simulations serve many uses. For one, the underlying physical models can be used by model-based health management tools to develop diagnostic and prognostic models. These simulations should incorporate both nominal and faulty behavior with the ability to inject various faults into the system. Such simulations can therefore be used for operator training, as well as for developing and prototyping health management algorithms.

Posted in: Briefs, TSP, Electronics & Computers, Simulation Software

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Building Blocks for the Rapid Development of Parallel Simulations

Goddard Space Flight Center, Greenbelt, Maryland Scientists need to be able to quickly develop and run parallel simulations without writing low-level message passing codes using compiled languages such as C/C++/Fortran. Traditionally, high-level languages that support rapid development, such as MATLAB, IDL, Mathematica, and Python, have not addressed parallel computing needs. Other parallel tools for high-level languages are very early in the development process and not mature, are very expensive and not open source, are typically limited to one or two models of parallel computing, do not allow collaborative parallel computing, have not fully addressed error handling, and are not asynchronous in nature.

Posted in: Briefs, TSP, Electronics & Computers, Simulation Software

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Automated Multibody Response (AMBER)

Lyndon B. Johnson Space Center, Houston, Texas AMBER is an automated tool for performing transient loads analysis of structural systems composed of one or more flexible bodies. Each body is initially supplied in Craig-Bampton form. Two basic solution approaches are available: traditional system assembly and multibody. The traditional approach is better suited for linear systems or for comparison to legacy analysis; the multibody approach is better suited for systems having gap or friction nonlinearities at the body-to-body interfaces, or for non-traditional damping.

Posted in: Briefs, Electronics & Computers

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Automotive Circuit Protection Using High-Reliability TVS Diodes

Diode technology eliminates transient surges and enhances vehicle safety. Littelfuse, Chicago, Illinois Designing automotive electronics presents numerous technical challenges, including the need to protect against electrical hazards. The three major sources of electrical hazards in automotive systems are electrostatic discharge (ESD), switching loads in power electronics circuits, and lightning. Overcoming these transient surges that can harm the vehicle’s electronics, whether under the hood or in the cabin, is one of the biggest obstacles of system design.

Posted in: Briefs, Power Management

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A Resistive, High-Voltage, Differential Input Interface in a 3.3-V BiCMOS 0.5-μm Process for Extreme Environments

NASA’s Jet Propulsion Laboratory, Pasadena, California Wide-temperature and extreme-environment electronics are crucial to future missions. These missions will not have the weight and power budget for heavy harnesses and large, inefficient warm boxes. In addition, extreme-environment electronics, by their inherent nature, allow operation next to sensors in the ambient environment, reducing noise and improving precision over the warm-box-based systems employed today.

Posted in: Briefs, TSP, Power Management, Sensors

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Precision Current Input With Well-Defined Current Limiting for Extreme Environment Applications

NASA’s Jet Propulsion Laboratory, Pasadena, California Wide temperature and extreme environment electronics are crucial to future missions. These missions will not have the weight and power budget for heavy harnesses and large, inefficient warm boxes. In addition, extreme environment electronics, by their inherent nature, allow operation next to sensors in the ambient environment, reducing noise and improving precision over the warm-box-based systems employed today.

Posted in: Briefs, TSP, Power Management, Sensors

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Algorithm for Estimating PRC Wavefront Errors from Shack-Hartmann Camera Images

Phase retrieval is used for the calibration and the fine-alignment of an optical system. NASA’s Jet Propulsion Laboratory, Pasadena, California Phase retrieval (PR) and Shack-Hartmann Sensor (SHS) are the two preferred methods of image-based wavefront sensing widely used in various optical testbeds, adaptive optical systems, and ground- and space-based telescopes. They are used to recover the phase information of an optical system from defocused point source images (PR) and focused point source or extended scene images (SHS). For example, the Terrestrial Planet Finder Coronagraph’s (TPF-C’s) High-Contrast Imaging Testbed (HCIT) uses a PR camera (PRC) to estimate, and subsequently correct, the phase error at the exit pupil of this optical system. Several other test-beds at JPL were, and will be, equipped with both a PRC and a Shack-Hartmann camera (SHC).

Posted in: Briefs, TSP, Cameras, Optics, Sensors

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