An automatic restart control system for an axisymmetric mixed-compression inlet
Automatic restart control system for axisymmetric mixed compression inlet
Cole, G. L.↗
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Performance evaluation of an evaporative water-recovery subsystem utilizing an automatic feed control
Performance evaluation of evaporative water recovery subsystem utilizing automatic feed control
Hall, J. B., Jr.↗
High stability FM TV transmitter with sampled automatic frequency control
S band frequency modulated television transmitter with sampled automatic frequency control designed to drive traveling-wave-tube amplifier
Honnell, M. A.↗
An automatic frequency control loop using overlapping DFTs (Discrete Fourier Transforms)
An automatic frequency control (AFC) loop is introduced and analyzed in detail. The new scheme is a generalization of the well known Cross Product AFC loop that uses running overlapping discrete Fourier transforms (DFTs) to create a discriminator curve. Linear analysis is included and supported with computer simulations. The algorithm is tested in a low carrier to noise ratio (CNR) dynamic environment, and the probability of loss of lock is estimated via computer simulations. The algorithm discussed is a suboptimum tracking scheme with a larger frequency error variance compared to an optimum strategy, but offers simplicity of implementation and a very low operating threshold CNR. This technique can be applied during the carrier acquisition and re-acquisition process in the Advanced Receiver.
Aguirre, S.↗
Studies and analyses of automatic command control communications and applications of time reference systems for automatic flight management Final report
Data links and time reference systems in automatic navigation and flight management
Boardman, C. H.↗
Wind modeling and lateral control for automatic landing
For the purposes of aircraft control system design and analysis, the wind can be characterized by a mean component which varies with height and by turbulent components which are described by the von Karman correlation model. The aircraft aero-dynamic forces and moments depend linearly on uniform and gradient gust components obtained by averaging over the aircraft's length and span. The correlations of the averaged components are then approximated by the outputs of linear shaping filters forced by white noise. The resulting model of the crosswind shear and turbulence effects is used in the design of a lateral control system for the automatic landing of a DC-8 aircraft.
Holley, W. E.↗
Automatic Frequency Control For DMSK Receiver
Report discusses performance of automatic frequency-control (AFC) subsystem of differential minimum-shift-keying receiver described in "DMSK Receiver for Moblile/Satellite Service," NPO-16659. Describes efforts to quantify behavior of system during acquisition of carrier signal; including theoretical analysis leading to numerical simulation, and measurements of performance of receiving equipment.
Davarian, Faramaz↗
Space tug automatic docking control study
A study was conducted to investigate the space tug automatic docking control capabilities. The subjects considered are: (1) docking sensor requirements, (2) the influence of the docking mechanism, and (3) the implications and effects of a docking abort. A digital computer simulation, was developed which included the primary aspects of the docking maneuver.
Wohl, J.↗
Automatic focus control for facsimile camera
Focus control performs function of automatically focusing facsimile camera throughout object field being scanned. It does this by determining and adjusting focus of imaging sensor accordingly. Since facsimile camera images a scene by scanning discrete strips, it is possible to have entire three-dimensional scene in perfect focus at point of imaging by use of focus control.
Sinclair, A. R.↗
Digital automatic gain control
Performance analysis, used to evaluated fitness of several circuits to digital automatic gain control (AGC), indicates that digital integrator employing coherent amplitude detector (CAD) is best device suited for application. Circuit reduces gain error to half that of conventional analog AGC while making it possible to automatically modify response of receiver to match incoming signal conditions.
Uzdy, Z.↗
Investigation of technical problems related to deployment and retrieval of spinning satellites
Quantitative analyses were developed to the point where numerical results can be easily obtained in the optimal transfer trajectory problem. Analyses of deployment dynamics and control of the paired satellite concept are progressing. Automatic control in space, optimal retrieval transfer trajectories, deployment attitude dynamics and control, and automatic control systems for retrieval are also considered.
Kaplan, M. H.↗
Solar electric propulsion thrust subsystem development
The Solar Electric Propulsion System developed under this program was designed to demonstrate all the thrust subsystem functions needed on an unmanned planetary vehicle. The demonstration included operation of the basic elements, power matching input and output voltage regulation, three-axis thrust vector control, subsystem automatic control including failure detection and correction capability (using a PDP-11 computer), operation of critical elements in thermal-vacuum-, zero-gravity-type propellant storage, and data outputs from all subsystem elements. The subsystem elements, functions, unique features, and test setup are described. General features and capabilities of the test-support data system are also presented. The test program culminated in a 1500-h computer-controlled, system-functional demonstration. This included simultaneous operation of two thruster/power conditioner sets. The results of this testing phase satisfied all the program goals.
Masek, T. D.↗
Furnace and support equipment for space processing
A core facility capable of performing a majority of materials processing experiments is discussed. Experiment classes are described, the needs peculiar to each experiment type are outlined, and projected facility requirements to perform the experiments are treated. Control equipment (automatic control) and variations of the Czochralski method for use in space are discussed.
Mazelsky, R.↗
Flight through thunderstorm outflows
Computer simulation of aircraft landing through thunderstorm gust fronts is carried out. The two-dimensional, nonlinear equations or aircraft motion containing all wind shear terms are solved numerically. The gust front spatial wind field inputs are provided in the form of tabulated experimental data which are coupled with a computer table lookup routine to provide the required wind components and shear at any given position within an approximate 500 m by 1 km vertical plane. The aircraft is considered to enter the wind field at a specified position under trimmed conditions. Both fixed control and automatic control landings are simulated. Flight paths, as well as control inputs necessary to maintain specified trajectories, are presented and discussed for aircraft having characteristics of a DC-8, B-747, augmentor-wing STOL, and a DHC-6.
Frost, W.↗
Flight through thunderstorm outflows
Computer simulation of aircraft landing through thunderstorm gust fronts is carried out. The 3 degree-of-freedom, nonlinear equations of aircraft motion for the longitudinal variables containing all two-dimensional wind shear terms are solved numerically. The gust front spatial wind field inputs are provided in the form of tabulated experimental data which are coupled with a computer table lookup routine to provide the required wind components and shear at any given position within an approximate 500 m x 1 km vertical plane. The aircraft is considered to enter the wind field at a specified position under trimmed conditions. Both fixed control and automatic control landings are simulated. Flight paths, as well as control inputs necessary to maintain specified trajectories, are presented and discussed for aircraft having characteristics of a DC-8, B-747, and a DHC-6.
Frost, W.↗
An approach to the synthesis of separate surface automatic flight control systems.
A method is presented for the analysis of separate surface automatic flight control systems. The feasibility of such systems is demonstrated by the analysis of an example system, a separate surface wing-leveler for a Cessna 172. This example system employs a separate surface aileron with 15% of the basic airplane roll control power. A 90% reduction in bank-angle gust response can be obtained when compared with the basic airplane. The system does not feed back to the pilot's wheel. When failed (even hardover) the pilot retains more than adequate control of the airplane.
Roskam, J.↗
Course and sequelae of body cooling by controlled hypothermia
Manual and automatic control of hypothermia - observations of dogs for one year after cooling experiments
HYPOTHERMIA↗
Automatic reel controls filler wire in welding machines
Automatic reel on automatic welding equipment takes up slack in the reel-fed filler wire when welding operation is terminated. The reel maintains constant, adjustable tension on the wire during the welding operation and rewinds the wire from the wire feed unit when the welding is completed.
Millett, A. V.↗