4,349 research outputs found

    Development of a Miniature Electrostatic Accelerometer /MESA/ for low g applications Summary report

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    Design, fabrication, and testing of miniature digital electrostatic accelerometer for low gravity measurements in spac

    Digital flight control research

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    The results of studies which were undertaken to contribute to the design of digital flight control systems, particularly for transport aircraft are presented. In addition to the overall design considerations for a digital flight control system, the following topics are discussed in detail: (1) aircraft attitude reference system design, (2) the digital computer configuration, (3) the design of a typical digital autopilot for transport aircraft, and (4) a hybrid flight simulator

    Development of a sensitive superconducting gravity gradiometer for geological and navigational applications

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    A sensitive and stable gravity gradiometer would provide high resolution gravity measurements from space. The instrument could also provide precision tests of fundamental laws of physics and be applied to inertial guidance systems of the future. This report describes research on the superconducting gravity gradiometer program at the University of Maryland from July 1980 to July 1985. The report describes the theoretical and experimental work on a prototype superconducting gravity gradiometer. The design of an advanced three-axis superconducting gravity gradiometer is also discussed

    A flight investigation of oscillating air forces: Equipment and technique

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    The equipment and techniques are described which are to be used in a project aimed at measuring oscillating air forces and dynamic aeroelastic response of a swept wing airplane at high subsonic speeds. Electro-hydraulic inertia type shakers installed in the wing tips will excite various elastic airplane modes while the related oscillating chordwise pressures at two spanwise wing stations and the wing mode shapes are recorded on magnetic tape. The data reduction technique, following the principle of a wattmeter harmonic analyzer employed by Bratt, Wight, and Tilly, utilizes magnetic tape and high speed electronic multipliers to record directly the real and imaginary components of oscillatory data signals relative to a simple harmonic reference signal. Through an extension of this technique an automatic flight-flutter-test data analyzer is suggested in which vector plots of mechanical admittance or impedance would be plotted during the flight test

    Biotelemetry of the triaxial ballistocardiogram and electrocardiogram in a weightless environment

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    Biotelemetry of triaxial ballistocardiogram and electrocardiogram in weightless environmen

    Vibration Isolation for Scanning Tunneling Microscope

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    Scanning Tunneling Microscopy (STM) works by scanning a fine metal wire over a conductive sample in order to image samples on the atomic level. The microscope uses a feedback loop with a PID controller to maintain a constant tunneling current between the sample and the tip. In order to obtain clear imaging at the atomic level, the microscope and the sample need to be isolated from external vibrations in a vacuum chamber. The scope for this project is to build and test a single-stage vibration isolation system that effectively attenuates the amplitude of external vibrations acting on the microscope. This document summarizes the preliminary design process, including the customer interviews we performed, the background research we collected about existing patents and designs, and the technical journal articles dealing with this subject that we read. In addition, this project defines the final design along with manufacturing and testing results to validate the design. The final design includes a final design description, design justification, manufacturing results, as well as the testing plan and results. These sections serve to overview the process for our final design selection and the results of the manufacturing and testing phases of the final design

    To perform a gyro test of general relativity in a satellite and develop associated control technology

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    Performance tests of gyroscope operations and gyroscope readout equipment are discussed. The gyroscope was tested for 400 hours at liquid helium temperatures with spin speeds up to 30 Hz. Readout by observing trapped magnetic flux in the spinning rotor with a sensitive magnetometer was accomplished. Application of the gyroscope to space probes and shuttle vehicles

    An automatic data system for vibration modal tuning and evaluation

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    A digitally based automatic modal tuning and analysis system developed to provide an operational capability beginning at 0.1 hertz is described. The elements of the system, which provides unique control features, maximum operator visibility, and rapid data reduction and documentation, are briefly described; and the operational flow is discussed to illustrate the full range of capabilities and the flexibility of application. The successful application of the system to a modal survey of the Skylab payload is described. Information about the Skylab test article, coincident-quadrature analysis of modal response data, orthogonality, and damping calculations is included in the appendixes. Recommendations for future application of the system are also made

    Analytical and experimental investigations of low level acceleration measurement techniques

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    Construction techniques for accelerometer with low level threshold sensitivit

    Apollo guidance, navigation and control - Design survey of the Apollo inertial subsystem

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    Design, development, and testing of inertial guidance and navigation systems for Apollo projec
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