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: Sira-Ramirez, Hebertt

Abstract: On-line closed loop system parameter identification for linear systems may be approached from an algebraic viewpoint based on non-commutative ring theory, module theory, and operational calculus. The approach can be made also robust with respect to a large class of system perturbation inputs and measurement noises. In this tutorial introduction to the algebraic approach for system identification and fast adaptive control, we illustrate, by means of simple examples, the use of the technique and some of its possible extensions.

Keywords: differential algebra,systems identification,fast adaptation and estimation

Digital Object Identifier (DOI): 10.3182/20071017-3-BR-2923.00003

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: 1-21

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: 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: Mendez, D. Hugo; Bonilla, E. Moises; Malabre, Michel

Abstract: In some control and observations problems, it is convenient, at least from the analysis point of view, to use non proper systems. However, for their implementation, proper approximations have to be designed. We show here how exponential approximations can be rather easily designed.

Keywords: linear systems,PD controllers,proper approximations

Digital Object Identifier (DOI): 10.3182/20071017-3-BR-2923.00006

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: 34-39

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: Kubalcik, Marek; Bobal, Vladimir

Abstract: The paper presents a comparison of two approaches applied to self - tuning control of a continuous - time two - input two - output system. In first case a continuous - time controller is used and since derivatives of an input and output of a controlled process can not be directly determined, the differential filters and filtered variables are established to substitute primary variables. The filtered variables are then used in the recursive identification procedure. The second method approximates the continuous - time system by a discrete linear model of the same order and a discrete controller is used. The classical recursive least squares method with the directional forgetting is then used to identify the system. Both discrete and continuous - time controllers which were applied to control the system are based on polynomial methods.

Keywords: self-tuning control,polynomial methods,multivariable control,pole assignment,adaptive control

Digital Object Identifier (DOI): 10.3182/20071017-3-BR-2923.00008

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: 46-51

Authors: Hua, Yunjie; Bara, Gabriela Iuliana; Boutayeb, Mohamed; Laroche, Edouard

Abstract: This paper addresses the problem of the observer synthesis for a class of discrete-time multimodel systems. The multimodel system is built using two subsystems with Lipschitz nonlinearities. Using a particular Lyapunov function, a sufficient condition for the existence of the observer is proposed. The problem is easily tractable by solving Linear Matrix Inequalities. A numerical example illustrates the applicability of our results.

Keywords: discrete-time multimodel system,Lipschitz nonlinear system,linear matrix inequalities

Digital Object Identifier (DOI): 10.3182/20071017-3-BR-2923.00009

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: 52-57

Authors: Sausen, Airam; Barros, Pericles Rezende

Abstract: In this paper a condition is determined for the nonlinear gain of the error-squared controller so that a nonlinear closed-loop system with such controller is asymptotically stable in the Lyapunov sense. Simulations had been made comparing the tuning method presented in this paper with tuning methods found in the literature.

Keywords: Lyapunov stabilization,nonlinear control,error-squared controllers

Digital Object Identifier (DOI): 10.3182/20071017-3-BR-2923.00010

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: 58-63

Authors: El'youssef, Ebrahim Samer; Moreno, Ubirajara F.; De Pieri, Edson R.; Neto, Eugenio B. Castelan

Abstract: In this work the application of a high-gain observer approach to the robust feedback linearization control is proposed to control a class of nonlinear systems, which all states can not be measured. The robust feedback linearization technique is used to transform the nonlinear system into its linear approximation around an equilibrium and the high-gain observer to estimate the states of the system.

Keywords: robust feedback linearization,high-gain observer,nonlinear systems

Digital Object Identifier (DOI): 10.3182/20071017-3-BR-2923.00011

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: 64-69

Authors: Franco, Ana Lucia Driemeyer; Bourles, Henri; De Pieri, Edson Roberto

Abstract: Robust feedback linearization of nonlinear systems without full state information is studied in this paper. The state is reconstructed from the output and the input by a linear observer combined with a diffeomorphism. It is shown that a separation principle holds, i.e., the estimated state can be used for performing robust feedback linearization, which exactly transforms the nonlinear system into a linear system equal to its linear approximation around a nominal operating point. Local stability of the resulting closed loop is proved by theoretical arguments and its robustness is illustrated through an example.

Keywords: nonlinear systems,feedback linearization,robust control,observers,magnetic bearings

Digital Object Identifier (DOI): 10.3182/20071017-3-BR-2923.00012

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: 70-75

Authors: Monzon, Pablo; Canale, Eduardo

Abstract: In this work, we analyze the almost global synchronization property of sinusoidally coupled oscillators. In contrast with previous works, we introduce an approach that uses the strong basic facts of algebraic graph theory to prove dynamical properties of the standard symmetric Kuramoto model. We show how we can interconnect two (or several) systems via bridges, keeping the almost global synchronization. These ideas can be used to explore other kinds of interconnections.

Keywords: almost global stability,Kuramoto coupled oscillators,nonlinear systems

Digital Object Identifier (DOI): 10.3182/20071017-3-BR-2923.00013

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: 76-81

Authors: Lam, H. K.; Seneviratne, L. D.

Abstract: This paper presents the stability and performance design of fuzzy-model-based control systems subject to parameter uncertainties. A nonlinear controller with a favorable characteristic to relax the stability conditions is proposed to drive the system states of the nonlinear plant to follow those of a stable reference model. Stability and performance conditions in terms of bilinear matrix inequalities are derived based on a Lyapunov-based approach. A genetic-based convex programming technique process is developed to solve the solution to the bilinear matrix inequalities. An application example is given to show the merits of the proposed approach.

Keywords: fuzzy control,stability

Digital Object Identifier (DOI): 10.3182/20071017-3-BR-2923.00014

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: 82-87

Authors: De Caigny, J.; Camino, J. F.; Paijmans, B.; Swevers, J.

Abstract: This work investigates an application of interpolating gain-scheduling control for a structural acoustic problem. The dynamics of the system under consideration are highly sensitive to variation in the temperature. Therefore, linear time invariant H2 output feedback controllers are designed for different temperature conditions. Afterwards, these controllers are interpolated to provide a global discrete-time linear parametervarying controller. The closed-loop stability is a posteriori guaranteed using recent less conservative analyses that consider bounds on the rate of variation of the temperature.

Keywords: active noise control,time varying system,parametric variation,discrete-time

Digital Object Identifier (DOI): 10.3182/20071017-3-BR-2923.00015

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: 88-93

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: Puyou, Guilhem; Jeanneau, Matthieu

Abstract: The works presented in this paper focus on implementation issues of complex dynamic flight control laws. Ambitious multi-criteria objectives and the need to cover the full flight domain of a transport aircraft increase implementation difficulties: interpolation of the control laws, numerical and discretization issues and fast retuning. Relevant methods for MIMO dynamic control laws are proposed, which proved their efficiency on both lateral and longitudinal aircraft control.

Keywords: flight control laws,real-time implementation,interpolation,predictor form,observer-state compensator

Digital Object Identifier (DOI): 10.3182/20071017-3-BR-2923.00017

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: 100-105

Authors: Poussot-Vassal, C.; Sename, O.; Dugard, L.; Gaspar, P.; Szabo, Z.; Bokor, J.

Abstract: In this paper we consider the design and analysis of a semi-active suspension controller. In the recent years different kinds of semi-active control strategies, like two-state Skyhook, LQ-clipped or model-predictive, have already been developed in the literature. In this paper we introduce a new semi-active suspension control strategy that achieves a priori limitations of a semi-active suspension actuator (dissipative constraint and force bounds) through the Linear Parameter Varying (LPV) theory. This new approach exhibits some interesting advantages compared to already existing methods (implementation, performance flexibility, robustness etc.). Both industrial criterion evaluation and simulations on nonlinear quarter vehicle model are performed to show the efficiency of the method and to validate the theoretical approach.

Keywords: semi-active suspension,linear parameter varying (LPV),H∞ control,linear matrix inequality (LMI)

Digital Object Identifier (DOI): 10.3182/20071017-3-BR-2923.00018

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: 106-111

Authors: Perez-Cruz, J. Humberto; Poznyak, Alexander

Abstract: In this paper, the automatic startup of a nuclear reactor subjected to period scram constraint is considered. To achieve this operation in a minimum time avoiding the difficulties associated with the application on-line of maximum principle or dynamic programming, first the optimal trajectory is calculated off-line. Next, the nuclear plant considered as a black box is identified by a differential neural network. The structure provided by this neural identifier is fed back to follow the optimal trajectory. The modeling error is compensated by the usage of the power derivative. Thus, the asymptotic stability of the tracking error can be guaranteed.

Keywords: nuclear reactor,differential neural network,constrained control

Digital Object Identifier (DOI): 10.3182/20071017-3-BR-2923.00019

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: 112-117

Authors: Silveira, H. B.; da Silva, P. S. Pereira

Abstract: This paper shows that, for flat affine time-invariant continuous-time nonlinear systems with two controls and five or less state variables, there exists a smooth change of coordinates and a time-invariant regular static state feedback such that the system is described by a triangular form. The presentation is based on an infinite-dimensional differential geometric approach to nonlinear control systems.

Keywords: nonlinear control systems,structural properties,control theory,differential geometric methods,co-ordinate transformations,state feedback

Digital Object Identifier (DOI): 10.3182/20071017-3-BR-2923.00020

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: 118-123

Authors: Marro, G.; Morbidi, F.; Prattichizzo, D.

Abstract: The paper proposes a very straightforward change of the general layout of the geometric approach to the feedforward and feedback model following problems for nonminimum-phase systems. The design technique relies on the replacement of the output matrix of the controlled system with an equally dimensioned matrix ensuring H2-optimality in the standard disturbance decoupling problem, while maintaining the relative degree and the steady-state gain of the original system. The new matrix is derived by applying the standard geometric approach tools to the Hamiltonian system instead of the original plant.

Keywords: linear systems,geometric approach,model following,nonminimum-phase systems,optimal tracking

Digital Object Identifier (DOI): 10.3182/20071017-3-BR-2923.00021

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: 124-129

Authors: de Souza, Eric Conrado; Maruyama, Newton

Abstract: In what follows, we employ a geometrical approach to the modeling of a proposed class of multibody systems through the Lagrangian setting. This approach yields an interesting decomposition of the system equations of motion in the shape, or relative coordinate, space and the inertial coordinate space.

Keywords: geometric mechanics,systems with symmetry,Lagrangian modeling

Digital Object Identifier (DOI): 10.3182/20071017-3-BR-2923.00022

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: 130-135

Authors: Malabre, Michel; Zou, Runmin

Abstract: The objective of this paper is to enhance new geometric properties which hold when the Almost Disturbance Decoupling Problem is solvable by state feedback (ADDP). The most important ones are summarized in a lattice description which, as usually, expresses algebraic relations based on sums and intersections, but also points out fundamental properties like exact or almost invariance, as well as exact or almost controllability.

Keywords: linear control systems,geometric approach,system structure,almost disturbance rejection,pole assignment

Digital Object Identifier (DOI): 10.3182/20071017-3-BR-2923.00023

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: 136-141

Authors: Kim, Sehjeong; Song, Insop

Abstract: Feedback control design is considered for stabilizing a discrete-time switched system with time-varying delay and time-varying uncertainty. In particular, we establish a practical method to construct feedback controllers to stabilize the system without requiring knowledge of the time-varying delay. First, we design feedback controllers which stabilize a non delayed switched system with time-varying uncertainty for any switching rule. Then, we quantify the maximum size of the time-varying delay which guarantees stability of the system of interest regardless of time-varying uncertainty. We achieve this via multiple Lyapunov functionals and the linear matrix inequalities framework.

Keywords: discrete-time switched systems,feedback control,Lyapunov functionals,time-varying uncertainty,time-varying delay,linear matrix inequalities (LMIs)

Digital Object Identifier (DOI): 10.3182/20071017-3-BR-2923.00024

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: 142-147

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