Preliminary analysis for lunar roving vehicle study, ground data systems and operations. Volume 1 - Roving vehicle guidance /Remote driving study/
Remote driving of lunar roving vehicle by superimposing driving aids on TV panorama
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Analysis of the failure of a polyester peripheral drive belt on the Mariner Mars 1971 flight tape recorder
A peripheral drive belt on the Mariner Mars 1971 tape recorder failed when a thin longitudinal strip separated off one edge. Analysis showed that the most probable cause of failure occurred from flexural fatigue initiating in mechanically weak locations which are introduced into the belt during fabrication. Methyl ethyl ketone, which is employed as a cleaning solvent during fabrication, was found to cause permanent reduction in engineering properties of polyester and could have contributed to the reduction of the fatigue resistance. Fatigue properties of the polyester drive belt are reviewed for the operating condition, as well as the sensitivity of polyester to cleaning solvents and the origin of mechanically weak locations.
Cuddihy, E. F.↗
Digital tape drive monitor
Network checks skew and character spacing of digital tape drive systems automatically. Tape drive is set up and calibrated to check any written tape when tape is read back. It will indicate track errors or character spacing errors should they exceed specifications.
Mckenna, R. T.↗
Transient and steady-state velocity of domain walls for a complete range of drive fields
Approximate analytic solutions for transient and steady-state 180 deg domain wall motion in bulk magnetic material are obtained from the dynamic torque equations with a Gilbert damping term. The results for the Walker region in which the transient solution approaches the familiar Walker steady-state solution are presented in a slightly new form for completeness. An analytic solution corresponding to larger drive fields predicts an oscillatory motion with an average value which decreases with drive field for reasonable values of the damping parameter. These results agree with those obtained by a computer solution of the torque equation and those obtained with the assumption of a very large anisotropy field.
Bourne, H. C., Jr.↗
Transient and steady-state velocity of domain walls for a complete range of drive fields
Approximate analytic solutions for transient and steady-state 180 deg domain-wall motion in bulk magnetic material are obtained from the dynamic torque equations with a Gilbert damping term. The results for the Walker region in which the transient solution approaches the familiar Walker steady-state solution are presented in a slightly new form for completeness. An analytic solution corresponding to larger drive fields predicts an oscillatory motion with an average value of the velocity which decreases with drive field for reasonable values of the damping parameter. These results agree with those obtained by others from a computer solution of the torque equation and those obtained by others with the assumption of a very large anisotropy field.
Bourne, H. C., Jr.↗
Development of a drive system for a sequential space camera contract modification 4(S)
The brush type dc motor and clutch were eliminated from the design of the 16 mm space sequential camera design and replaced by an electronically commutated motor. The new drive system reduces the current consumption at 24 fps to 220 mA. The drive can be programmed and controlled externally from the multipurpose programmable timer/intervalometer, as well as being controlled locally from the camera.
Sharpsteen, J. T.↗
Drive Train Normal Modes Analysis for the ERDA/NASA 100-Kilowatt Wind Turbine Generator
Natural frequencies, as a function of power were determined using a finite element model. Operating conditions investigated were operation with a resistive electrical load and operation synchronized to an electrical utility grid. The influence of certain drive train components on frequencies and mode shapes is shown. An approximate method for obtaining drive train natural frequencies is presented.
Sullivan, T. L.↗
Noble gases in 60009-60010 drive tube samples - Trapped gases and irradiation history
Concentrations and isotopic composition of noble gases are reported for grain size separates: nine soils from the 60010-60009 double drive tube, two soils from the 60007 drill core section, and surface soil 65501. Data are reported on concentrations of solar wind gases, surface-correlated gases (involving solar wind and lunar atmosphere), surface maturity indices, cosmogenic gases, possible soil mixing, and irradiation by cosmic rays. Good correlation is found between solar wind gases in 60009 soils and such surface maturity indices as petrographic agglutinates, magnetic soil fraction, and fine-grained iron. Cosmogenic He-3, Ne-21, Ar-38, Kr-80, and Xe-126 all display close correlations in the drive tube soils.
Bogard, D. D.↗
Drive train dynamic analysis
A method for parametric variations in drive train dynamic analysis is described. The method models the individual components of a drive system, forms the appropriate system interface coordinates and, calculates the system dynamic response at particular frequencies. Application of the method for prediction of the dynamic response characteristics of a helicopter transmission, and a comparison of results with test data are also included.
Giansante, N.↗
Apparatus for providing a servo drive signal in a high-speed stepping interferometer
An analog voltage approximately linearly proportional to a desired offset from the present null position of a moving mirror in an interferometer is applied to the mirror moving means. As the mirror moves to the next null position, as determined by the analog voltage, the fringes of a laser reference interference pattern are detected. At the occurrence of each fringe the analog voltage is reduced proportionally so that when the next null position is reached, this driving analog is effectively zero. A binary up/down counter, by its internal count, causes a digital/analog converter to supply the analog voltage to the mirror moving means. Fringe detection and direction of movement logic cause the binary up/down counter to be decremented from its offset count as the mirror is moved to the new null position. Undesirable movement of the mirror due to vibration or other sources causes a correcting drive signal to be applied to the mirror moving means that is proportional to the distance of movement.
Schindler, R. A.↗
The Apollo 16 drive tube 60009/60010. I - Modal petrology
Detailed petrographic examination of 22 thin sections from the impregnated portion of the Apollo 16 double drive tube supports the findings of previous workers. A well-gardened unit exists at the top of 60010, indicated petrographically by an increase in agglutinates near the lunar surface. There is a coarse-grained anorthositic layer near the bottom of 60009. Few, if any, of the modal variations are stratigraphically correlatable with the deep drill core 60002-7, which was recovered 50 m southwest of drive tube 60009/60010.
Simon, S. B.↗
Quiet Clean Short-haul Experimental Engine (QCSEE): Hamilton Standard cam/harmonic drive variable pitch fan actuation system detail design report
A variable pitch fan actuation system was designed which incorporates a remote nacelle-mounted blade angle regulator. The regulator drives a rotating fan-mounted mechanical actuator through a flexible shaft and differential gear train. The actuator incorporates a high ratio harmonic drive attached to a multitrack spherical cam which changes blade pitch through individual cam follower arms attached to each blade trunnion. Detail design parameters of the actuation system are presented. These include the following: design philosophies, operating limits, mechanical, hydraulic and thermal characteristics, mechanical efficiencies, materials, weights, lubrication, stress analyses, reliability and failure analyses.
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Application of laser ranging and VLBI data to a study of plate tectonic driving forces
The measurability of changes in plate driving or resistive forces associated with plate boundary earthquakes by laser rangefinding or VLBI is considered with emphasis on those aspects of plate forces that can be characterized by such measurements. Topics covered include: (1) analytic solutions for two dimensional stress diffusion in a plate following earthquake faulting on a finite fault; (2) two dimensional finite-element solutions for the global state of stress at the Earth's surface for possible plate driving forces; and (3) finite-element solutions for three dimensional stress diffusion in a viscoelastic Earth following earthquake faulting.
Solomon, S. C.↗
Computer program documentation D1FLTD to drive SINDA boundary nodes: User's guide
The thermal model correlation process begins when measured thermocouple data is available from the orbital flight tests of the shuttle. For this effort, it is necessary to convert some of the system improved numerical differencing analyzer (SINDA) diffusion or arithmetic nodes to boundary nodes and then drive these boundary nodes to the temperature profile of a flight measurement. An efficient way to provide this capability within the SINDA and OFT software systems is to provide a new SINDA routine, D1FLTD, for use in VARIABLES 1 of SINDA, to access the processed (word-addressable) orbital data reduction center flight data and store the appropriate measurement temperature in the desired SINDA temperature location. The ODRC flight data that is to be used for driving the boundary nodes must be assigned a logical unit number and must reside on a word-addressable file. The user must also provide two SINDA constants for the word positions of the first and last words of the temperature record for each measurement identifier (MID), i.e. each call to D1FLTD, used in the model. D1FLTD is then called from the VARIABLES 1 block to obtain the SINDA boundary node temperature for any MID on the file at any time point.
Damico, S. J.↗
Axial force and efficiency tests of fixed center variable speed belt drive
An investigation of how the axial force varies with the centerline force at different speed ratios, speeds, and loads, and how the drive's transmission efficiency is affected by these related forces is described. The tests, intended to provide a preliminary performance and controls characterization for a variable speed belt drive continuously variable transmission (CVT), consisted of the design and construction of an experimental test rig geometrically similar to the CVT, and operation of that rig at selected speed ratios and power levels. Data are presented which show: how axial forces exerted on the driver and driven sheaves vary with the centerline force at constant values of speed ratio, speed, and output power; how the transmission efficiency varies with centerline force and how it is also a function of the V belt coefficient; and the axial forces on both sheaves as normalized functions of the traction coefficient.
Bents, D. J.↗
High frequency drive mechanism for an active controls systems aircraft control surface
The mechanism was successfully utilized on a wind tunnel model tested in the transonic blow down tunnel. The mechanism is also applicable to a flying aircraft. Several interrelated mechanical subsystems were utilized, including a low inertia antibacklash drive mechanism for high frequency oscillation and a compact antibacklash drive mechanism for conversion of rotary motion to linear motion.
Smith, H. E.↗
Characterization, performance, and prediction of a lead-acid battery under simulated electric vehicle driving requirements
A state-of-the-art 6-V battery module in current use by the electric vehicle industry was tested at the NASA Lewis Research Center to determine its performance characteristics under the SAE J227a driving schedules B, C, and D. The primary objective of the tests was to determine the effects of periods of recuperation and long and short periods of electrical regeneration in improving the performance of the battery module and hence extendng the vehicle range. A secondary objective was to formulate a computer program that would predict the performance of this battery module for the above driving schedules. The results show excellent correlation between the laboratory tests and predicted results. The predicted performance compared with laboratory tests was within +2.4 to -3.7 percent for the D schedule, +0.5 to -7.1 percent for the C schedule, and better than -11.4 percent for the B schedule.
Ewashinka, J. G.↗
The 34-meter antenna drive control system
Detailed definitions of the baseline antenna drive and control/instrumentation equipment for 34 meter antennas included in Network Consolidation Program of the Deep Space Network are presented. The overall antenna control and monitor system and its interfaces with other higher level control and monitor equipment is described. Explicit descriptions of the antenna axis drive motors and motor controllers, the axis angle encoding systems, and miscellaneous antenna located components are presented, and related to system functional and performance requirements. Some potential alternates to the baseline system configuration are described and discussed.
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