Robust Periodic Observer-based Control For Periodic Discrete-time Ltv Systems

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)New conditions for the design of robust periodic observer-based controllers for periodic discrete-time linear time-varying (LTV) systems are proposed in this paper. The control system is designed to be robust to external noises, and such robustness is achieved by minimizing the H-infinity norm from the input noise to the error output in the observer design, and the H-infinity norm from the error and disturbance signal to the output in the control design. Concerning the observer, two LMI (Linear Matrix Inequality) conditions are proposed. As part of the main contribution, an LMI condition, based on a dual representation of the LTV system, is also proposed for the synthesis of a robust state-feedback controller that makes use of the observed states rather than the actual states. A numerical example illustrates the validity of the proposed technique.29422947Brazilian agency CAPES [2014/03669-1, 2015/00269-5]Brazilian agency CNPq [2014/03669-1, 2015/00269-5]Brazilian agency Sao Paulo Research Foundation (FAPESP) [2014/03669-1, 2015/00269-5]Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)American Control Conference (ACC)JUL 06-08, 2016Boston, M

Robust periodic observer-based control for periodic discrete-time LTV systems

New conditions for the design of robust periodic observer-based controllers for periodic discrete-time linear time-varying (LTV) systems are proposed in this paper. The control system is designed to be robust to external noises, and such robustness is achieved by minimizing the H-infinity norm from the input noise to the error output in the observer design, and the H-infinity norm from the error and disturbance signal to the output in the control design. Concerning the observer, two LMI (Linear Matrix Inequality) conditions are proposed. As part of the main contribution, an LMI condition, based on a dual representation of the LTV system, is also proposed for the synthesis of a robust state-feedback controller that makes use of the observed states rather than the actual states. A numerical example illustrates the validity of the proposed technique29422947CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPsem informaçãosem informação2014/03669-1; 2015/00269-5American Control Conference (ACC)2016-07-06Boston, MA, Estados Unido

Robust Performance and Observer Based Control for Periodic Discrete-Time Uncertain Systems

This paper presents an approach for the synthesis of observer-based controllers for discrete-time periodic linear systems. The H2 performance criterion has been employed to design both the observer and the controller. For the periodic observer design, two conditions in the form of Linear Matrix Inequalities (LMIs) are proposed, which stem from the Lyapunov Theory applied over the dynamics of the estimation error. The LMI condition obtained for the periodic state-feedback controller results from the application of the duality principle over the periodic system, under the assumption that only the estimated states are available to be used in the state-feedback compensation. Numerical experiments illustrate the potential of the proposed observer-based control technique

An Adaptive Run Length Encoding Method For The Compression Of Electrocardiograms.

A compression method, based on the choice of a wavelet that minimizes the distortion of compression for each electrocardiogram considered, is proposed in this paper. The scaling filter used on the determination of the wavelet function is obtained from the resolution of an optimization problem, which is unconstrained since the scaling filter is parametrized in a way that the constraints applied to the scaling filter are embedded on the parameters. The coefficients of projection of the signal over the wavelet subspaces are calculated and only the most significant ones are retained, being the significant coefficients determined in order to satisfy a pre-specified distortion measure. The bitmap that informs the positions of the retained coefficients is encoded along with the values of the coefficients by using an improved version of the Run Length Encoding technique. Experiments that compare the proposed approach with other techniques illustrate the efficiency of the method.35145-5