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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Range switching digital filter with three predetermined quantization levels decreases quantization deadband. Mathematical program form implements the transfer function of the filter.
Sampled data control, quantization effects, and transfer function for Saturn 5 thrust vector control
The purpose of this report is twofold: (1) to survey the established analytic procedures for the simulation of controlled flexible space vehicles, and (2) to develop in detail methods that employ a combination of discrete and distributed ("modal") coordinates, i.e., the hybrid-coordinate methods. Analytic procedures are described in three categories: (1) discrete-coordinate methods, (2) hybrid-coordinate methods, and (3) vehicle normal-coordinate methods. Each of these approaches is described and analyzed for its advantages and disadvantages, and each is found to have an area of applicability. The hybrid-coordinate method combines the efficiency of the vehicle normal-coordinate method with the versatility of the discrete-coordinate method, and appears to have the widest range of practical application. The results in this report have practical utility in two areas: (1) complex digital computer simulation of flexible space vehicles of arbitrary configuration subject to realistic control laws, and (2) preliminary control system design based on transfer functions for linearized models of dynamics and control laws.
Derivation of transfer function for optical system relating image intensity to spatial autocorrelation
Pneumatic instrumentation line transfer function approximated by system model for simplifying reactor control system analysis
Feedback systems analysis, considering single phase and polyphase coupled and uncoupled commutation networks in forward loop and linear transfer function feedback loop
Network synthesis technique applied to structural dynamics design, using topological formulas to express systems response transfer functions
Coefficient quantization in digital continuous time process controllers, applying results to nominal transfer function approximation
Feedback controller for linear stationary differential systems with time lag and fixed unknown parameters, noting closed loop transfer function role
State variable feedback design of m-input, m- output time invariant linear systems requiring noninteraction and exact transfer functions, considering coupled core nuclear reactor
Filters, formed by combinations of distributed RC elements with positive-feedback voltage amplifiers, provide transfer functions similar to those the heavier LC filters ordinarily employ. They also provide signal amplification.
Digital controllers, one using a special-purpose computer and the other using a combination of digital and analog techniques, are designed around /1/ computers that simulate the transfer function and interface with the system, and /2/ analog and digital circuits, converters, amplifiers, constant multipliers, and delay lines that form a digital filter.
Transfer function relating control torques to attitudes angles considering structural flexibility
Vibro-acoustic transfer function correlation with structural and acoustic parameters
Linear networks fault detection and isolation using computerized test procedure and symbolic transfer function generation technique
Cylindrical shell response to random acoustic excitation, considering single point transfer functions and equivalent force power spectral densities
Distributed-lumped-active network to produce transfer function with pair of high Q zero real part sensitivity poles
Algorithm for inverse Laplace transformation of irrational transfer function via fast Fourier transform