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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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Parameter identification algorithm identifying linear dynamic systems by digital computer used to identify human operator characteristics in closed loop control situation
Circuit, placed in the signal path of a closed-loop receiver to modulate telemetered data in the 10-MHz spectrum, improves signal-to-noise ratio by 3 db in a communication receiver. The switch enables bandwidth reduction which reduces noise overload on the following stages, giving the system greater dynamic range.
Position control of burning solid nonmetallized propellant strand in combustion bomb using closed loop servomechanism
Closed loop frequency response analyzer with steepest descent computing procedure to obtain in-phase and quadrature signal components in linear or nonlinear systems
Pilot/vehicle dynamics from flight test records, discussing close-loop attitude control tasks
Pilot-aircraft closed-loop characteristics, using pilot transfer functions for handling qualities prediction
Motion cue requirements in one and two axis closed loop compensatory control tracking tasks, discussing error rates
Output feedback control systems design, considering closed loop system sensitivity to plant parameters based on linear optimal control problem
Algorithm for trajectory analysis in closed loop terminal guidance of solar electrically thrusted interplanetary spacecraft
Solar cell array maximum power point in scientific satellites via closed loop conductance matching regulator
Circuit extends concept of redundant feedback control from type-0 to type-1 control systems. Inactive channels are slaves to the active channel, if latter fails, it is rejected and slave channel is activated. High reliability and elimination of single-component catastrophic failure are important in closed-loop control systems.
Fringe pattern motion is compensated by closed-loop servo system that adjusts a mirror mounted on piezoelectric crystal, so that path difference in interferometer is maintained at constant values at one point in the field. System is applicable to holography with continuous wave laser sources.
Monitor improves complex network reliability in computer data links and command transmission lines. System evaluates circuit performance against preselected criteria, identifies and stores data indicating out-of-tolerance conditions, conducts closed loop testing, and provides for operation under command of digital computer that determines restoration priorities.
Calibrator generates accurate flow velocities over wide range of gas pressure, temperature, and composition. Both pressure and flow velocity can be maintained within 0.25 percent. Instrument is essentially closed loop hydraulic system containing positive displacement drive.
Carbon dioxide concentrator subsystem for closed loop aircrew oxygen system
Closed loop servosystem for variable speed tape recorders on board spacecraft
Astronaut space nutrition, discussing Apollo mission short range nonregenerative mode, long range closed loop regenerative cycles and waste recycling
Discrete time finite dimensional autonomous linear systems, investigating controllability and pole assignment to closed loop transfer matrix by choice of state variable feedback gain