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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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Necessary conditions for optimal lunar trajectories with discontinuous state variables and intermediate point constraints
State variable feedback design of control system for coupled core nuclear reactor
Monograph on state variable approach to continuous estimation of random processes with applications to analog communication theory
A model-following, state variable feedback controller is designed for the roll axis of the X-14. The approach is to define a criterion on roll axis performance and to find the gradient of this criterion in the space of parameters (the feedback gains) of the controller. The gradient is then used in a conjungate gradient descent sequence to numerically optimize the parameters.
Linear and nonlinear control systems via state variable feedback with applications in nuclear reactor control
Conference proceedings on applying differential equation or state variable techniques to radar and communication system problems
Modified perturbation method for solving optimal control boundary value problems with state variable inequality constraints, noting application to reentry trajectories
Absolute stability of dynamic control systems with single nonlinear element function of two feedback state variables, giving sufficient conditions
Sufficient conditions derived for absolute stability of dynamic systems containing nonlinear functions of several state variables
Popov type nonlinear control systems from synthesis viewpoint, using state variable feedback results to insure absolute stability
Slack variable to transform optimal control problem with scalar inequality constraint on state variables into unconstrained problem of higher dimension
Slack variable to transform optimal control problem with scalar inequality constraint on state variables into unconstrained problem
Digital computer program based on matrix formulation for analysis and design of linear state variable feedback systems
Thermodynamic properties effects on transverse acceleration wave propagation in inhomogeneous isotropic elastic bodies with internal state variables
The paper describes methods for extracting unknown state variables and parameters from dynamic rotor model tests given transient cyclic pitch stirring inputs, blade root flap-bending measurements, and the form of the dynamic rotor equations, including a rotor dynamic inflow description, when none of the physical parameters are known. A simplified version of the maximum likelihood method seems best suited for this purpose. The measurement equation error covariance matrix is assumed constant during each iteration, but updated for the subsequent iteration. A detailed analysis of the suitability of the derived techniques for studying various rotor dynamic inflow effects is provided.
This paper derives three discrete state variable representations for a continuous-time plant driven by a zero-order hold with a combination of instantaneous measurements and measurements prefiltered by a multiinput/multioutput moving average (MA) process. These representations allow the control system engineer to model plants of this type accurately in a form which permits him to use standard techniques to design digital feedback controllers for them. An example is presented which illustrates how to obtain the coefficient matrices in each representation. Guidelines are presented for choosing the best representation to use for any given plant of this type.
Optimum state variable selection to determine constraints for nonlinear system stability, using Liapunov second method
Markov parametric algorithm for effective construction of minimal realizations of linear state-variable finite-dimensional dynamical systems from input-output data