Reconstruction of sampled input of a linear system from its sampled output
Computer processing which reconstructs sampled input of linear system from its sampled output and its unit step response
SAMPLED DATA↗
SEARCH · Search NASA
Results for “LINEAR SYSTEM”
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.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
On the design of optimal linear systems using only output-variable feedback.
Optimal control of linear systems with state variables generated by linear feedback from output variables, considering time variance
Athans, M.↗
Fixed order dynamic compensation for multivariable linear systems
This paper considers the design of fixed order dynamic compensators for multivariable time invariant linear systems, minimizing a linear quadratic performance cost functional. Attention is given to robustness issues in terms of multivariable frequency domain specifications. An output feedback formulation is adopted by suitably augmenting the system description to include the compensator states. Either a controller or observer canonical form is imposed on the compensator description to reduce the number of free parameters to its minimal number. The internal structure of the compensator is prespecified by assigning a set of ascending feedback invariant indices, thus forming a Brunovsky structure for the nominal compensator.
Kramer, F. S.↗
Perfect decoupling of linear systems with discrete parameter uncertainties
A design procedure based on Gilbert's decoupling parameters for determining a fixed state feedback control law which decouples a linear system with discrete parameter uncertainties is described. Perfect decoupling conditions are established which involve a test for the existence of a solution to a system of linear equations. An actual solution of the linear equations yields the decoupling control law.
Dorato, P.↗
Iterative solution of large, sparse linear systems on a static data flow architecture - Performance studies
The applicability of static data flow architectures to the iterative solution of sparse linear systems of equations is investigated. An analytic performance model of a static data flow computation is developed. This model includes both spatial parallelism, concurrent execution in multiple PE's, and pipelining, the streaming of data from array memories through the PE's. The performance model is used to analyze a row partitioned iterative algorithm for solving sparse linear systems of algebraic equations. Based on this analysis, design parameters for the static data flow architecture as a function of matrix sparsity and dimension are proposed.
Reed, D. A.↗
Optimal output-feedback controllers for linear systems
Matrix method for optimal feedback control of linear systems
Levine, W. S.↗
Invariance in linear systems
Invariance conditions and state transition matrix of linear systems
Aggarwal, J. K.↗
Polynomial matrices, representations, and linear system theory
Frequency domain analogies, polynomial matrices, and linear systems
Wolovich, W. A.↗
On a stochastic control method for weakly coupled linear systems
The stochastic control of two weakly coupled linear systems with different controllers is considered. Each controller only makes measurements about his own system; no information about the other system is assumed to be available. Based on the noisy measurements, the controllers are to generate independently suitable control policies which minimize a quadratic cost functional. To account for the effects of weak coupling directly, an approximate model, which involves replacing the influence of one system on the other by a white noise process is proposed. Simple suboptimal control problem for calculating the covariances of these noises is solved using the matrix minimum principle. The overall system performance based on this scheme is analyzed as a function of the degree of intersystem coupling.
Kwong, R. H.↗
Linear system identification - The application of Lion's identification scheme to a third order system with noisy input-output measurements
A linear system identification technique developed by Lion is adapted for use on a third-order system with six unknown parameters and noisy input-output measurements. A digital computer is employed so that rapid identification takes place with only two state variable filters. Bias in the parameter estimates is partially eliminated by a signal-to-noise ratio testing procedure.
Brown, C. M., Jr.↗
Recursive inversion of externally defined linear systems
The approximate inversion of an internally unknown linear system, given by its impulse response sequence, by an inverse system having a finite impulse response, is considered. The recursive least squares procedure is shown to have an exact initialization, based on the triangular Toeplitz structure of the matrix involved. The proposed approach also suggests solutions to the problems of system identification and compensation.
Bach, Ralph E., Jr.↗
A program for identification of linear systems
A program has been written for the identification of parameters in certain linear systems. These systems appear in biomedical problems, particularly in compartmental models of pharmacokinetics. The method presented here assumes that some of the state variables are regularly modified by jump conditions. This simulates administration of drugs following some prescribed drug regime. Parameters are identified by a least-square fit of the linear differential system to a set of experimental observations. The method is especially suited when the interval of observation of the system is very long.
Buell, J.↗
Adaptive stochastic control for linear systems. I - Solution method
Linear discrete time stochastic system with unknown gain parameters, interpreting open loop feedback optimal control identifier and controller equations
Athans, M.↗
Analysis of piece-wise linear systems by the method of integral equations
Digital computer approximation of automatic control piecewise linear systems by integral equations
INTEGRAL EQUATION↗
Observer-based robust-H-infinity control laws for uncertain linear systems
Based on the algebraic Riccati equation approach, this paper presents a simple and flexible method for designing observer-based robust-H-infinity control laws for linear systems with structured parameter uncertainty. The observer-based robust-H-infinity output-feedback control law, obtained by solving three augmented algebraic Riccati equations, provides both robust stability and disturbance attenuation with H-infinity-norm bound for the closed-loop uncertain linear system. Several tuning parameters are embedded into the augmented algebraic Riccati equations so that flexibility in finding the symmetric positive-definite solutions (and hence, the robust-H-infinity control laws) is significantly increased. A benchmark problem associated with a mass-spring system, which approximates the dynamics of a flexible structure, is used to illustrate the design methodologies, and simulation results are presented.
Shieh, Leang S.↗
Solution of linear systems by a singular perturbation technique
An approximate solution is obtained for a singularly perturbed system of initial valued, time invariant, linear differential equations with multiple boundary layers. Conditions are stated under which the approximate solution converges uniformly to the exact solution as the perturbation parameter tends to zero. The solution is obtained by the method of matched asymptotic expansions. Use of the results for obtaining approximate solutions of general linear systems is discussed. An example is considered to illustrate the method and it is shown that the formulas derived give a readily computed uniform approximation.
Ardema, M. D.↗
Algorithm for worst error in linear systems with bounded input and its rate of change.
Computational worst error algorithm for linear systems and quadratic error criteria, showing flowgraph and computer execution results
ERROR DETECTING CODE↗
Linear control design for guaranteed stability of uncertain linear systems
In this paper, a linear control design algorithm based on the elemental perturbation bounds developed recently is presented for a simple second order linear uncertain system satisfying matching conditions. The proposed method is compared with Guaranteed Cost Control (GCC), Multistep Guaranteed Cost Control (MGCC) and the Matching Condition (MC) methods and is shown to give guaranteed stability with lesser values for the control gains than some of the existing methods for the example considered.
Yedavalli, R. K.↗