Test & Measurement

Application of a Physics-Based Stabilization Criterion to Flight System Thermal Testing

This innovation consists of a procedure and set of equations that allows thermal balance steady-state temperatures to be predicted hours before the balance is reached based on current temperature and rate-of-change measurements. This will allow tests to run faster, since thermal plateau settings may be adjusted prior to reaching an equilibrium state. Additionally, it will allow the test conductors to identify future limit violations hours before they may happen, which would increase flight hardware safety. A similar methodology can be used to predict component temperatures in flight, assuming a relatively constant sink temperature condition, which would be useful for long cool-down missions such as the James Webb Space Telescope (JWST).

Posted in: Briefs, TSP, Test & Measurement, Mathematical analysis, Flight control systems, Thermal testing


Trajectory Specification for High-Capacity Air Traffic Control

Automating separation monitoring and guidance would relieve human controllers of the primary responsibility for safe separation. The doubling or tripling of airspace capacity that will be needed over the next several decades will require that tactical separation guidance be automated for appropriately equipped aircraft in high-density airspace. Four-dimensional (4D) trajectory assignment (three-dimensional position as a function of time) will facilitate such automation. A standard trajectory specification format based on XML (Extensible Markup Language) is proposed for that purpose.

Posted in: Briefs, TSP, Electronics & Computers, Test & Measurement, Computer software and hardware, Flight guidance systems, Air traffic control


Numerical Evaluation of Near-Hypersingular Integrals

A document discusses a method for simple and efficient numerical integration (quadrature) of integrals characterized by a near-hypersingularity. Near-hypersingular integrals arise in gradients of Newton-type potentials when the fields at a desired observation point are close to the source. The method designed here provides for accurate and efficient integration for both the strongly and weakly singular terms. Suitable cancellation techniques for numerical computation of weakly-singular integrals have been identified, and this method is a cancellation type and handles multiple singularity types.

Posted in: Briefs, TSP, Information Sciences, Test & Measurement, Mathematical analysis, Research and development


Ultrasonic Intake Airflow Meter for Testbeds

The airflow meter measures extremely dynamic phenomena of combustion engines without being affected by ambient influences or sensor contamination. An ultrasonic intake airflow meter for engine testbed applications was developed. An automotive intake airflow meter must fulfill a series of requirements differentiating it from typical ultrasonic flow meters. First, the data sampling rate of the device must be as high as possible to be able to measure dynamic phenomena of the combustion engine. It is therefore necessary to use broadband ultrasonic transducers capable of sending short signals without post-pulse oscillations. The state-of-the-art piezoelectric transducers cannot fulfill these requirements. For this reason, the FLOWSONIX

Posted in: Briefs, Physical Sciences, Test & Measurement, Combustion and combustion processes, Engines, Test procedures


Rapid Infrared Pixel Grating Response Testbed

A test array has been developed to measure the response of pixel-integrated infrared gratings over a wavelength range from 3 to 13 μm for multiple grating geometries. This array allows for testing and for determining the performance of an infrared focal plane array camera before resources have been committed to the design and fabrication of the final array.

Posted in: Briefs, TSP, Test & Measurement, Optics, Test equipment and instrumentation


JWST Integrated Simulation and Test (JIST) Core

Modeling techniques and hardware models have potential commercial applications for projects that deploy similar solutions. The James Webb Space Telescope (JWST) Integrated Simulation and Test (JIST) environment is a software-only system simulator that provides an environment to exercise JWST flight software subsystems and interfaces. JIST is capable of executing the unmodified flight software binaries in an operational environment that can be configured on a single personal computer. JIST utilizes the JWST ground system, ground system command and telemetry databases, simulated flight computers, instrument simulators, and environment simulators. Some of the capabilities provided by JIST include the ability to load and run any version of the flight software, inject errors (faults) from ground system test procedures, save simulation state (processor and simulators), and simulate external hardware devices. Many components are potentially reusable on future missions. In addition, the modeling techniques and models have potential commercial applications for projects that deploy similar hardware solutions.

Posted in: Briefs, TSP, Test & Measurement, Computer simulation, Flight control systems, Test equipment and instrumentation


JWST IV&V Simulation and Test (JIST) Solid State Recorder (SSR) Simulator

Dynamic analysis capabilities are provided with no hardware in the loop.As described in “JWST Integrated Simulation and Test (JIST) Core” (GSC-16739-1) on page 25, the JIST system is a software-based simulator that uses the James Webb Space Telescope (JWST) operational ground system, ground system command/telemetry databases, simulated flight computers, and unmodified flight software binaries to provide dynamic analysis capabilities. There is no hardware in the loop; the flight software communicates over a simulated MIL-STD-1553 and Spacewire port. The JIST SSR Simulator is a reusable component of the JIST system, and is responsible for simulating basic SSR functionality.

Posted in: Briefs, TSP, Test & Measurement, Computer simulation, Flight control systems, Test equipment and instrumentation


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