Authors: None

Abstract:

Keywords:

Digital Object Identifier (DOI): 10.3182/20071017-3-BR-2923.90001

Conference: 3rd IFAC Symposium on Power System, Structure and Control (2007)

Location: Mabu Thermas Convention Center, Brazil

Start Date: Wed Oct 17 2007 - End Date: Fri Oct 19 2007

Page Numbers: ---

Authors: None

Abstract:

Keywords:

Digital Object Identifier (DOI): 10.3182/20071017-3-BR-2923.90002

Conference: 3rd IFAC Symposium on Power System, Structure and Control (2007)

Location: Mabu Thermas Convention Center, Brazil

Start Date: Wed Oct 17 2007 - End Date: Fri Oct 19 2007

Page Numbers: ---

Authors: Akcay, Huseyin; Turkay, Semiha

Abstract: In this paper, we study interpolation of rational matrix functions which are analytic at infinity and discuss the properties of a recently proposed interpolation algorithm related to the frequency-domain subspace-based identification methods. The efficiency of the algorithm is illustrated with a step-by-step numerical example.

Keywords: rational interpolation,subspace-based,identification

Digital Object Identifier (DOI): 10.3182/20071017-3-BR-2923.00096

Conference: 3rd IFAC Symposium on Power System, Structure and Control (2007)

Location: Mabu Thermas Convention Center, Brazil

Start Date: Wed Oct 17 2007 - End Date: Fri Oct 19 2007

Page Numbers: 596-601

Authors: Alazard, Daniel; Apkarian, Pierre

Abstract: In this paper, it is proposed to implement a given controller using observer-based structures in order to estimate or to monitor some unmeasured plant states or external disturbances. Such a monitoring can be used to perform in-line or off-line analysis (supervising controller modes, capitalizing flight data to improve disturbance modelling, ...). This observer-based structure must involve a judicious onboard model selected to be representative of the physical phenomenon one want to monitor. This principle is applied to an aircraft longitudinal flight control law to monitor wind disturbances and to estimate the angle-of-attack.

Keywords: monitoring,flight control law,observer-based,estimation

Digital Object Identifier (DOI): 10.3182/20071017-3-BR-2923.00016

Conference: 3rd IFAC Symposium on Power System, Structure and Control (2007)

Location: Mabu Thermas Convention Center, Brazil

Start Date: Wed Oct 17 2007 - End Date: Fri Oct 19 2007

Page Numbers: 94-99

Authors: Aleixo, J. C.; Rocha, P.

Abstract: The properties of reconstructibility and forward-observability for systems over the whole time axis Z are introduced and characterized in terms of appropriate rank conditions. A comparison is made with the existing results in the behavioral setting as well as in the classical state space framework.

Keywords: behavior,difference equations,discrete-time systems,dynamic systems,linear systems,mathematical systems theory,time-invariant systems

Digital Object Identifier (DOI): 10.3182/20071017-3-BR-2923.00062

Conference: 3rd IFAC Symposium on Power System, Structure and Control (2007)

Location: Mabu Thermas Convention Center, Brazil

Start Date: Wed Oct 17 2007 - End Date: Fri Oct 19 2007

Page Numbers: 374-379

Authors: Araujo, Jose M.; Castro, Alexandre C.; Silva, Fabricio G. S.; Santos, Eduardo T. F.; Dorea, Carlos E. T.

Abstract: State feedback is a modern control technique that, amongst diverse applications, is distinguished by its arbitrary pole-placement of a controllable, linear time-invariant system. This benefit brings a series of consequences, such as the stabilization of a system or designing control using one single technique. On the other hand, the state-derivative feedback was introduced later, and it is capable to arbitrarily place poles, with some restrictions in particular cases. This work aims to establish a comparative study between these two techniques, from the point of view of simple, but important concepts in control theory, as well as confirming some relations between respective advantages from these two techniques.

Keywords: linear systems,state feedback,state-derivative feedback,pole-placement

Digital Object Identifier (DOI): 10.3182/20071017-3-BR-2923.00005

Conference: 3rd IFAC Symposium on Power System, Structure and Control (2007)

Location: Mabu Thermas Convention Center, Brazil

Start Date: Wed Oct 17 2007 - End Date: Fri Oct 19 2007

Page Numbers: 28-33

Authors: Assuncao, Edvaldo; Andrea, Cristiano Quevedo; Teixeira, Marcelo Carvalho Minhoto; Cardim, Rodrigo; Pinto, Joao Onofre Pereira

Abstract: The problem of signal tracking and disturbance rejection in linear continuous time-invariant systems with uncertain parameters is solved using a zero variation and dynamic output feedback, considering polytopic uncertainties in the plant parameters. It is used a feedback controller Kp(s) to minimize the H2 guaranteed cost from the disturbance input to the output signal. And so, one uses the zeros of the controller in order to design the tracking system. The design is formulated in Linear Matrix Inequality (LMI) framework, such that the optimal solution of the stated control problem is obtained. Simulation of a practical problem illustrates the effectiveness of the proposed method.

Keywords: zeros variation,tracking,polytopic uncertain,LMIs

Digital Object Identifier (DOI): 10.3182/20071017-3-BR-2923.00101

Conference: 3rd IFAC Symposium on Power System, Structure and Control (2007)

Location: Mabu Thermas Convention Center, Brazil

Start Date: Wed Oct 17 2007 - End Date: Fri Oct 19 2007

Page Numbers: 626-631

Authors: Augusta, P.; Hurak, Z.; Rogers, E.

Abstract: In this paper we develop new results on control systems design for spatially distributed linear systems using an n-D systems approach. The basic ideas are explained using as an example heat conduction in a rod where the measurements and control action applied are based on an array of sensors and heaters. The first part of the analysis given shows how the process dynamics for this case can be approximately described by a 2-D transfer function, i.e. a fraction of two bivariate polynomials. This is followed by stability analysis and tests. Finally, a Youla-Kučera parametrization of all stabilizing controllers is used to develop a simple design procedure for H2-optimal control laws.

Keywords: distributed-parameter systems,spatially distributed systems,multidimensional systems,multivariate polynomials

Digital Object Identifier (DOI): 10.3182/20071017-3-BR-2923.00033

Conference: 3rd IFAC Symposium on Power System, Structure and Control (2007)

Location: Mabu Thermas Convention Center, Brazil

Start Date: Wed Oct 17 2007 - End Date: Fri Oct 19 2007

Page Numbers: 196-201

Authors: Azevedo-Perdicoulis, Teresa Paula; Jank, Gerhard

Abstract: The aim of this paper is to represent the dynamics, as well as the coupling, of a gas network through a DAE system, with the intention to model the optimisation of the same network as a LQ game with disturbances. The DAE system is formed by the two Kirchhoff Laws and a discretised hyperbolic model which represents the gas transients in the pipeline. We consider a complex network, i.e. a network with loops and nonpipe elements with some of them being controllable. To conclude, the whole modelling process is illustrated by a simple example network.

Keywords: coupling nonpipe elements,DAE systems,gas network modelling,singular systems

Digital Object Identifier (DOI): 10.3182/20071017-3-BR-2923.00007

Conference: 3rd IFAC Symposium on Power System, Structure and Control (2007)

Location: Mabu Thermas Convention Center, Brazil

Start Date: Wed Oct 17 2007 - End Date: Fri Oct 19 2007

Page Numbers: 40-45

Authors: Bazanella, A. S.; Gevers, M.; Miskovic, L.; Anderson, B. D. O.

Abstract: An H2 control performance criterion dependent on a controller parameter vector is analyzed from the point of view of evaluating the domain of attraction of its global minimum when a gradient-based algorithm is used in tuning the parameters. The objective of this analysis is twofold: (i) examine how some design parameters of the criterion can be used to enlarge the domain of attraction; (ii) examine how the minimization of a sequence of intermediate criteria can possibly lead to the global minimum of the original criterion without the danger of entrapment in a local minimum.

Keywords: optimal control,control system synthesis,performance indices

Digital Object Identifier (DOI): 10.3182/20071017-3-BR-2923.00032

Conference: 3rd IFAC Symposium on Power System, Structure and Control (2007)

Location: Mabu Thermas Convention Center, Brazil

Start Date: Wed Oct 17 2007 - End Date: Fri Oct 19 2007

Page Numbers: 190-195

Authors: Benallouch, Mohamed; Outbib, Rachid; Boutayeb, Mohamed; Hernandez, Andreas

Abstract: This paper is a contribution to the problem of state estimation. More precisely, it concerns the case of time-varying linear systems. The goal is twofold. First to improve some results on state estimation. Second, to use this strategy to investigate the problem of diagnosis for PEM fuel cells process. Simulations results are given in order to illustrate the performances of the proposed approach.

Keywords: time-varying systems,state estimation,functional observer,linear matrix inequalities,fuel cells

Digital Object Identifier (DOI): 10.3182/20071017-3-BR-2923.00080

Conference: 3rd IFAC Symposium on Power System, Structure and Control (2007)

Location: Mabu Thermas Convention Center, Brazil

Start Date: Wed Oct 17 2007 - End Date: Fri Oct 19 2007

Page Numbers: 500-505

Authors: Bender, Fernando Augusto; da Silva, Joao Manoel Gomes

Abstract: A method for synthesizing dynamic output feedback controllers for discrete time systems presenting actuators constrained in amplitude, rate and acceleration is proposed. The considered controller structure, composed by two saturating integrator blocks and a linear compensator, allows to deliver to the actuator input a signal inside all its bounds. Anti-windup loops in the controller are simultaneously designed and add degrees of freedom to the synthesis process, besides improving performance. Sufficient LMI conditions for such stabilizing controller existence are derived and exemplified. Optimization problems for maximizing disturbance tolerance and rejection are considered.

Keywords: anti-windup,saturation,L2 performance,discrete time,LMI

Digital Object Identifier (DOI): 10.3182/20071017-3-BR-2923.00082

Conference: 3rd IFAC Symposium on Power System, Structure and Control (2007)

Location: Mabu Thermas Convention Center, Brazil

Start Date: Wed Oct 17 2007 - End Date: Fri Oct 19 2007

Page Numbers: 512-517

Authors: Bourles, Henri

Abstract: Two complete and intrinsic definitions of linear systems are existing: (i) in the behavioral approach, a linear system is the kernel B of a matrix-valued operator R in a power of a signal space W; (ii) in the module theoretic setting, a linear system is the cokernel M of R (thus, M is a finitely presented module over a ring of operators). These two formulations have connections and under certain conditions the knowledge of M is equivalent to that of B. The minimal conditions under which such an equivalence exists are investigated in this paper and the case of convolution systems is especially considered.

Keywords: linear systems,duality,time delay,controllability

Digital Object Identifier (DOI): 10.3182/20071017-3-BR-2923.00063

Conference: 3rd IFAC Symposium on Power System, Structure and Control (2007)

Location: Mabu Thermas Convention Center, Brazil

Start Date: Wed Oct 17 2007 - End Date: Fri Oct 19 2007

Page Numbers: 380-385

Authors: Boyarski, S.; Shaked, U.

Abstract: This paper addresses a robust H∞ Linear Time-Invariant (LTI) filter synthesis problem for an affinely parameter-dependent LTI system, under the requirement that the filtering performance attained over the uncertainty polytope is guaranteed to a prescribed probability. The solution is based on a novel filtering-type Linear Matrix Inequality (LMI) formulation of the Bounded-Real Lemma (BRL) that guarantees an upper bound on the disturbance effect on the estimation error. The approach applies parameter-dependent Lyapunov functions and provides general full-order stationary filtering estimates; filters of reduced order are also obtained. The core of the probability aspect is a search for a truncated parameters- polytope which provides both the required probability and the best robust filtering performance level. The search for an appropriate truncated parameter-box - that has already been used for probabilistic performance analysis, state-feedback control synthesis, and structured disturbances modeling - leads to Bi-Linear Matrix Inequalities (BLMIs) which are solved by (convex) iterations. The probability requirement is expressed as a set of simple LMIs by recursively using a reduction lemma; these LMIs are concurrently solved with the above BLMIs. The features of the proposed probability-guaranteed robust filtering approach are demonstrated via an example.

Keywords: robust estimation,LMI,polytopic uncertainty,H∞ filtering,probabilistic performance

Digital Object Identifier (DOI): 10.3182/20071017-3-BR-2923.00054

Conference: 3rd IFAC Symposium on Power System, Structure and Control (2007)

Location: Mabu Thermas Convention Center, Brazil

Start Date: Wed Oct 17 2007 - End Date: Fri Oct 19 2007

Page Numbers: 326-331

Authors: Briat, C.; Sename, O.; Lafay, J.-F.

Abstract: This paper deals about the synthesis of parameter dependent observers for linear parameter varying time delay systems. These observers are computed to satisfy an H∞ performance attenuation from the disturbances to the state estimation error. First a stability test is proposed using the Lyapunov-Krasovskii approach and the Newton's formula. It is provided in terms of gridded parameter dependent LMIs. Second, this stability test is derived to obtain a sufficient condition to the existence of a (parameter dependent) observer. Our results are illustrated through an example which demonstrates the benefits of this approach.

Keywords: LPV time delay systems,gain-scheduling,observers,LMI

Digital Object Identifier (DOI): 10.3182/20071017-3-BR-2923.00025

Conference: 3rd IFAC Symposium on Power System, Structure and Control (2007)

Location: Mabu Thermas Convention Center, Brazil

Start Date: Wed Oct 17 2007 - End Date: Fri Oct 19 2007

Page Numbers: 148-153

Authors: Canitrot, S.; Boukhobza, T.; Hamelin, F.; Martinez-Martinez, S.

Abstract: This work is dedicated to the study of control/fault diagnosis interactions for structured bilinear systems using a graph-theoretic approach. According to the fact that constant control inputs make possible the representation of a bilinear system by a linear one, some propositions provide the sufficient conditions for active-BFPRG (Bilinear Fundamental Problem of Residual Generation) in this particular case. These conditions are easy to check because they are based on the comparison of expressions and on finding paths in a digraph.

Keywords: structural properties,bilinear systems,fault diagnosis,graph theory

Digital Object Identifier (DOI): 10.3182/20071017-3-BR-2923.00106

Conference: 3rd IFAC Symposium on Power System, Structure and Control (2007)

Location: Mabu Thermas Convention Center, Brazil

Start Date: Wed Oct 17 2007 - End Date: Fri Oct 19 2007

Page Numbers: 655-660

Authors: Cardim, Rodrigo; Teixeira, Marcelo C. M.; Assuncao, Edvaldo; Covacic, Marcio R.

Abstract: A simple method for designing a state-derivative feedback gain and a feedforward gain such that the control law is equivalent to a known and adequate state feedback and reference feedforward control law is presented. It is assumed that the plant is a linear controllable, time-invariant, Single-Input (SI) or Multiple-Input (MI) system. This procedure allows the use of well-known state feedback design methods to directly design state-derivative feedback control systems. The state-derivative feedback can be useful in the control of mechanical systems, using accelerometers as sensors. Three examples considering the pole-placement and decoupling problems illustrated the proposed method.

Keywords: state-derivative feedback,state feedback,linear multi-input (MI) systems,decoupling problem,pole assignment,eigenvalue placement

Digital Object Identifier (DOI): 10.3182/20071017-3-BR-2923.00004

Conference: 3rd IFAC Symposium on Power System, Structure and Control (2007)

Location: Mabu Thermas Convention Center, Brazil

Start Date: Wed Oct 17 2007 - End Date: Fri Oct 19 2007

Page Numbers: 22-27

Authors: Casagrande, Daniele; Kotta, Ulle; Wyrwas, Malgorzata

Abstract: The paper studies the nonlinear control systems on time scales that serve as models of time and unify the continuous and discrete time. The realization problem for single-input single-output nonlinear delta differential systems is studied through the language of differential forms. Necessary and sufficient conditions are given for the existence of a state-space realization of the nonlinear input-output delta differential equation, i.e. a higher order delta differential equation relating the input, the output and a finite number of their delta-derivatives. The sufficiency part of the proof gives a constructive procedure (up to the integration of one-forms) for obtaining an observable state-space description.

Keywords: nonlinear control systems,continuous-time systems,discrete-time systems,observability,realization,time scale

Digital Object Identifier (DOI): 10.3182/20071017-3-BR-2923.00059

Conference: 3rd IFAC Symposium on Power System, Structure and Control (2007)

Location: Mabu Thermas Convention Center, Brazil

Start Date: Wed Oct 17 2007 - End Date: Fri Oct 19 2007

Page Numbers: 356-361

Authors: Castelan, Eugenio B.; Moreno, Jones Corso Ubirajara F.; De Pieri, Edson R.

Abstract: This paper presents some results on stability and stabilization of a class of uncertain nonlinear discrete-time systems under control saturations. The studied control law consists of the feedback of both the states and of the nonlinearity present in the dynamics of the controlled system. Saturations are taken into account by modeling the nonlinear saturated system through a deadzone nonlinearity satisfying a modified sector condition. Thus, as for precisely known systems, LMI stability and stabilization conditions are proposed, which can be cast into convex programming problems. Some relations of the proposed results with the poly-quadratic stability concept are included.

Keywords: nonlinear systems,saturations,parameter dependent Lyapunov functions,LMIs,robustness

Digital Object Identifier (DOI): 10.3182/20071017-3-BR-2923.00083

Conference: 3rd IFAC Symposium on Power System, Structure and Control (2007)

Location: Mabu Thermas Convention Center, Brazil

Start Date: Wed Oct 17 2007 - End Date: Fri Oct 19 2007

Page Numbers: 518-523

Authors: Castillo-Toledo, B.; Loukianov, A. G.; Di Gennaro, S.

Abstract: In a general command tracking and disturbance rejection problem, it is known that a sampled-data controller using zero-order hold may only guarantee asymptotic tracking at the sampling instances, but in general cannot guarantee the absence of ripples between the sampling instants. In this paper, a sampled-data robust controller using slide modes techniques and exponential holder is presented. It is shown that this controller ensures asymptotic tracking when applied to the continuous-time system.

Keywords: sliding-mode control,regulator theory,discretization,exponential holder

Digital Object Identifier (DOI): 10.3182/20071017-3-BR-2923.00060

Conference: 3rd IFAC Symposium on Power System, Structure and Control (2007)

Location: Mabu Thermas Convention Center, Brazil

Start Date: Wed Oct 17 2007 - End Date: Fri Oct 19 2007

Page Numbers: 362-367

Authors: Chalh, Z.; Achir, A.; Sueur, C.

Abstract: The paper deals with the characterization of invariant zeros of MIMO linear time varying systems using the bond graph methodology. Thanks to the exploitation of the algebraic framework of modules, a direct procedure for the computation of the invariant zeros is developed. The paper ends with an example illustrating the implementation of the proposed approach.

Keywords: invariant zeros,bond graphs,modules,LTV systems

Digital Object Identifier (DOI): 10.3182/20071017-3-BR-2923.00087

Conference: 3rd IFAC Symposium on Power System, Structure and Control (2007)

Location: Mabu Thermas Convention Center, Brazil

Start Date: Wed Oct 17 2007 - End Date: Fri Oct 19 2007

Page Numbers: 542-547

Authors: Colaneri, Patrizio; de Souza, Valeska M.

Abstract: In this paper we study the almost sure stability of continuous-time jump linear systems with a finite-state Markov form process. A new sufficient condition is derived based on an extended Lyapunov-Metzler inequality. This condition is proven to be less conservative with respect to the existing sufficient conditions. The inequalities generalize those associated with mean square stability and establish a clear link between the two notions. The problem of almost sure stabilizability and detectability is finally discussed.

Keywords: Markov jump systems,switched systems,Lyapunov functions,stochastic stability

Digital Object Identifier (DOI): 10.3182/20071017-3-BR-2923.00041

Conference: 3rd IFAC Symposium on Power System, Structure and Control (2007)

Location: Mabu Thermas Convention Center, Brazil

Start Date: Wed Oct 17 2007 - End Date: Fri Oct 19 2007

Page Numbers: 244-249

Authors: Commault, Christian; Dion, Jean-Michel; Agha, Sameh Yacoub

Abstract: In this paper we deal with the observer based Fault Detection and Isolation problem. When this FDI problem is solvable with the existing sensors, we will classify these sensors according to their importance for the solvability of the considered FDI problem. The sensors will be classified into essential sensors, useless sensors and useful sensors. We tackle this problem when the system under consideration is structured, that is, the entries of the system matrices are either fixed zeros or free parameters. With such structured systems one can associate a graph. Simple algorithms allow to get from the graph the above sensor classification.

Keywords: linear systems,structured systems,fault detection and isolation,sensor classification

Digital Object Identifier (DOI): 10.3182/20071017-3-BR-2923.00107

Conference: 3rd IFAC Symposium on Power System, Structure and Control (2007)

Location: Mabu Thermas Convention Center, Brazil

Start Date: Wed Oct 17 2007 - End Date: Fri Oct 19 2007

Page Numbers: 661-666

Authors: Coutinho, D. F.; de Souza, C. E.; Barbosa, K. A.

Abstract: This paper proposes an improved robust H∞ filter design for the class of discrete-time linear parameter varying systems with the state-space model matrices depending rationally on time-varying parameters. The system is described by a difference-algebraic representation and the parameters admissible values and variations are assumed to belong to given intervals. A convex optimization approach in terms of linear matrix inequalities, and which incorporates information on available bounds on the parameters variation, is devised to the filter design based on Lyapunov functions with rational dependence on the system parameters. A numerical example illustrates the effectiveness of the proposed method.

Keywords: robust H∞ filter,linear parameter varying systems,discrete-time systems,parameter-dependent Lyapunov function

Digital Object Identifier (DOI): 10.3182/20071017-3-BR-2923.00053

Conference: 3rd IFAC Symposium on Power System, Structure and Control (2007)

Location: Mabu Thermas Convention Center, Brazil

Start Date: Wed Oct 17 2007 - End Date: Fri Oct 19 2007

Page Numbers: 320-325

Authors: da Silva, Jaidilson Jo; Lima, Antonio Marcus Nogueira; da Rocha Neto, Jose Sergio

Abstract: Fouling detection is a relevant problem for chemical, oil, food and pharmaceutical industries. Fouling consists of the deposition of heavy organic materials and other dissolved solids or in suspension in fluid transport system. The ultrasonic guided waves present specific characteristics and have demonstrated good results in detection of flaws in pipelines. This work presents the results of the parameters estimation, based on the Gaussian pulses model, of a system that uses guided waves for fouling detection in pipelines. Initially are made simulations and the use of FFT (Fast Fourier Transformer) of the ultrasound signal is proposed to determine the present frequencies and to reduce the number of parameters estimated. With the obtained estimation model, it intends to observe the modifications of the parameters when the fouling occurs in the monitored pipeline.

Keywords: fouling detection,ultrasonic waves,parameter estimation

Digital Object Identifier (DOI): 10.3182/20071017-3-BR-2923.00092

Conference: 3rd IFAC Symposium on Power System, Structure and Control (2007)

Location: Mabu Thermas Convention Center, Brazil

Start Date: Wed Oct 17 2007 - End Date: Fri Oct 19 2007

Page Numbers: 572-577