Search results for "State variable"
showing 10 items of 50 documents
Microprocessor-Based Suboptimal Control of Converter-Fed Hypo-Hypersynchronous Cascade Drives
1983
Abstract This work consists of a theoretic and experimental study of a possible practical realization of a microprocessor-based control system using a converter-fed hypo-hypersynchronous cascade drive. Firstly, the design of a microprocessor-based controller is carried out considering an approximate mathematical model, linear-type, of the drive in question, by using optimal control techniques. Several ρhysical constraints, such as input variables con straints, state variables constraints and processing time of microprocessor are taken into account. The approach followed allows us to obtain a suboptimal closed-looρ control system. In addition, in order to carry out a more accurate study of t…
Parameter estimation: an advanced simulation tool in biomedicine
1990
Parameter estimation as an advanced tool in biomedicine have become extremely important in the study of biological systems. With increasing physiological knowledge and more efficient computers, modelling, simulation, and estimation have grown during the past 20 years to one of the most powerful tools of biomedical system analysis. Moreover modelling, simulation and estimation is of growing importance for determination of non-measurable parameters and state variables of biomedical systems as well as for case studies research of biomedical processes, which have been developed by physicians and system engineers and have also been widely accepted by biomedical scientists. These models already d…
Multiplicative cases from additive cases: Extension of Kolmogorov–Feller equation to parametric Poisson white noise processes
2007
Abstract In this paper the response of nonlinear systems driven by parametric Poissonian white noise is examined. As is well known, the response sample function or the response statistics of a system driven by external white noise processes is completely defined. Starting from the system driven by external white noise processes, when an invertible nonlinear transformation is applied, the transformed system in the new state variable is driven by a parametric type excitation. So this latter artificial system may be used as a tool to find out the proper solution to solve systems driven by parametric white noises. In fact, solving this new system, being the nonlinear transformation invertible, …
Dynamic Output-Feedback Passivity Control for Fuzzy Systems under Variable Sampling
2013
Published version of an article in the journal: Mathematical Problems in Engineering. Also available from the publisher at: http://dx.doi.org/10.1155/2013/767093 Open Access This paper concerns the problem of dynamic output-feedback control for a class of nonlinear systems with nonuniform uncertain sampling via Takagi-Sugeno (T-S) fuzzy control approach. The sampling is not required to be periodic, and the state variables are not required to be measurable. A new type fuzzy dynamic output-feedback sampled-data controller is constructed, and a novel time-dependent Lyapunov-Krasovskii functional is chosen for fuzzy systems under variable sampling. By using Lyapunov stability theory, a sufficie…
On the dynamics of non-local fractional viscoelastic beams under stochastic agencies
2018
Abstract Non-local viscoelasticity is a subject of great interest in the context of non-local theories. In a recent study, the authors have proposed a non-local fractional beam model where non-local effects are represented as viscoelastic long-range volume forces and moments, exchanged by non-adjacent beam segments depending on their relative motion, while local effects are modelled by elastic classical stress resultants. Long-range interactions have been given a fractional constitutive law, involving the Caputo's fractional derivative. This paper introduces a comprehensive numerical approach to calculate the stochastic response of the non-local fractional beam model under Gaussian white no…
Solution to nonlinear MHDS arising from optimal growth problems
2011
Abstract In this paper we propose a method for solving in closed form a general class of nonlinear modified Hamiltonian dynamic systems (MHDS). This method is used to analyze the intertemporal optimization problem from endogenous growth theory, especially the cases with two controls and one state variable. We use the exact solutions to study both uniqueness and indeterminacy of the optimal path when the dynamic system has not a well-defined isolated steady state. With this approach we avoid the linearization process, as well as the reduction of dimension technique usually applied when the dynamic system offers a continuum of steady states or no steady state at all.
Sensorless induction machine drive for fly-wheel generation unit based on a TLS-based non-linear observer
2016
This paper proposes a sensorless technique for an induction machine Flywheel Energy Storage System (FESS) based on a non-linear observer integrated with a total least-squares speed estimator taking into consideration the IM (Induction Machine) saturation effects. The nonlinear observer is based on an original formulation of the dynamic model of the IM including the magnetic saturation, rearranged in a space-state form, after assuming as state variables the stator current and the rotor magnetizing current space-vectors in the stator reference frame. The choice of the observer gain has been made by the use of Lyapunov's method. The speed signal needed by the non-linear observer for the flux e…
The Closed-Form Solution for a Family of Four-Dimension Non-Linear MHDS
2002
In this paper I propose a method for solving in closed form a general class of four-dimension non-linear modified Hamiltonian dynamic systems. This method may be used to study several intertemporal optimization problems with a predetermined structure, involving unbounded technological constraints as well as multiple controls and state variables. The method is developed here by solving the first order conditions corresponding to the socially optimal solution to the Lucas (1988) two-sector model of endogenous growth.
Fiber Suspension Flows: Simulations and Existence Results
2016
Main result of this article is demonstrating the weak global in time well posedness result for the equations governing fiber suspension flows for sufficiently small initial data under mild assumptions about the nonlinear equation for fiber orientation dynamics and the constitutive law, thus extending the previous local in time results. The required estimate of growth of the H 2 norm is granted if the L ∞ norm of fiber orientation state variables remains bounded. This is the case for fiber orientation tensors.
Existence and uniqueness of solutions to a quasilinear parabolic equation with quadratic gradients in financial markets
2005
A quasilinear parabolic equation with quadratic gradient terms is analyzed. The equation models an optimal portfolio in so-called incomplete financial markets consisting of risky assets and non-tradable state variables. Its solution allows to compute an optimal portfolio strategy. The quadratic gradient terms are essentially connected to the assumption that the so-called relative risk aversion function is not logarithmic. The existence of weak global-in-time solutions in any dimension is shown under natural hypotheses. The proof is based on the monotonicity method of Frehse. Furthermore, the uniqueness of solutions is shown under a smallness condition on the derivatives of the covariance (?…