SEARCH · Engineering Papers
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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Laser feedback control automatically maintains silicon melt levels. During long-term growth of dendritic-web silicon, silicon melt level controlled and held nearly constant using laser feedback system to sense level of melt and control silicon-pellet feed rate.
Nonlinear system suboptimal feedback control technique based on method for determining approximate solutions for Hamilton-Jacobi- Bellman equation
Control system response improvement by state variable feedback illustrated by frequency and transient response tests data from analog model
Feedback control systems synthesis by three parameter space, using two dimensional graphic techniques
Liapunov design technique for model reference adaptive control systems with feedback and prefilter adjustable gains
A thermodynamically efficient garment for cooling and/or heating a human body. The thermodynamic efficiency is provided in part by targeting the heat exchange capabilities of the garment to specific areas and/or structures of the human body. The heat exchange garment includes heat exchange zones and one or more non-heat exchange zones, where the heat exchange zones are configured to correspond to one or more high density tissue areas of the human body when the garment is worn. A system including the garment can be used to exchange heat with the adjacent HD tissue areas under the control of a feedback control system. Sensed physiological parameters received by the feedback control system can be used to adjust the characteristics of heat exchange fluid moving within the heat exchange garment.
Linear and nonlinear control systems via state variable feedback with applications in nuclear reactor control
Linear optimal feedback control synthesis for nuclear reactor system models
The problem of controlling a time-invariant system with parameter uncertainty is considered with incomplete state feedback. The controller is designed by minimaximizing a quadratic performance criterion and a sensitivity (or loss) criterion, involving the state of the system, the control, and the uncertainty vector. The resulting optimal controller is linear and optimal feedback gain matrix must satisfy a set of nonlinear algebraic equations. some algorithms for algebraic minimax problems are presented.
System theory - matrices, feedback control system, network synthesis, set theory, stability, shift registers, coding, theorem proving, polynomial roots, channels, and signal flow graphs
Desensitized linear servo model following feedback control systems design using specific optimal control concepts
Comparison of relative effects of cascade and feedback compensation on steady-state and dynamic performance of feedback control systems
Parameter-plane method analysis of nonlinear equations of asymmetric oscillations in adaptive feedback control systems
Nonlinear dynamic compensation scheme enhances stability of feedback control system in which feedback signal includes quantization noise. Compensator slows response of control system at low error signals to diminish effect of quantization noise but provides faster response at large error signals to speed correction of large errors.
Matrix method for optimal feedback control of linear systems
Stability theory for nonlinear time-varying feedback control systems
Theorems on stabilities of feedback control systems proved. Paper presents recent developments regarding theorems of absolute stability and hyperstability of feedforward-and-feedback control system. Theorems applied in analysis of nonlinear, adaptive, and robust control. Extended to provide sufficient conditions for stability in system including nonlinear feedback subsystem and linear time-invariant (LTI) feedforward subsystem, state space of which is Hilbert space, and input and output spaces having finite numbers of dimensions. (In case of absolute stability, feedback subsystem memoryless and possibly time varying. For hyperstability, feedback system dynamical system.)
Integral and peak sensitivities defined for state- variable feedback control system