Process operating mode monitoring : switching online the right controller

This paper presents a structure which deals with process operating mode monitoring and allows the control law reconfiguration by switching online the right controller. After a short review of the advances in switching based control systems during the last decade, we introduce our approach based on the definition of operating modes of a plant. The control reconfiguration strategy is achieved by online selection of an adequate controller, in a case of active accommodation. The main contribution lies in settling up the design steps of the multicontroller structure and its accurate integration in the operating mode detection and accommodation loop. Simulation results show the effectiveness of the operating mode detection and accommodation (OMDA) structure for which the design steps propose a method to study the asymptotic stability, switching performances improvement, and the tuning of the multimodel based detector

An automatic control course without the Laplace transform. An operational point of view

The question is: Is the Laplace transform needed in an Automatic Control course? The answer is : Obviously, not! Based on an operational standpoint the first parts are about guidelines for a primer in automatic control. Beyond an undergraduate course, the two last parts, a little bit more technical, are devoted on the one hand to get the model of a computer controlled system and on the other hand to relate the operational standpoint to usual tables used in some cases

A design procedure for a single time-varying functional observer

The paper proposes an algorithm for the design of a single functional observer for a linear time-varying system. The proposed constructive procedure can be iterated to obtain a minmal order for the observer where the existence conditions are fufilled. As a specific feature, the proposed procedure does not require the solution of a differential Sylvester equation

Some contributions to estimation for model-free control

This paper describes some contributions to Model Free Control (MFC). For example,its properties about disturbance rejection are analyzed. It is also shown that it is possible to propose new estimation methods for an extended version for MFC using time-varying parameters of an ultra-local model. In particular it is emphasized that these parameters can be estimated using alternative and standard adaptation methods. An application to a thermal process model illustrates one specific point of the new adaptive approach

Bond graph modeling for the simulation of an electromechanical chain

In complex multi-physic systems such as electromechanical chains, it is necessary to establish clear and simple simulation models. This need is linked to the increase of hardware in the loop (HIL) development processes. Indeed, this way of design complex systems allows to reduce development costs. However, HIL development efficiency is linked to the accuracy of models. Consequently, complex systems must be modeled using a comprehensive approach such as bond graphs leading to equations easily implementable on simulators. This paper proposes a model of a whole electromechanical chain including some nonlinearities of parameters leading to an accurate representation of real systems

An operational standpoint in electrical engineering

In electrical engineering education exists a major difficulty for first level students, namely the Laplace transform. The question is: does this ubiquitous tool is needed in an electrical engineering course? Our answer is: Obviously, not. Based on an operational standpoint the paper describes some guidelines and results for a primer on handling signals and linear systems without using the Laplace transform. The main advantage is that the operational standpoint leads to simplified proofs for well-known results

A direct design procedure for linear state functional observers

We propose a constructive procedure to design a Luenberger observer to estimate a linear multiple linear state functional for a linear time-invariant system. Among other features the proposed design algorithm is not based on the solution of a Sylvester equation nor on the use of canonical state space forms. The design is based on the solution set of a linear equation and a realization method. The consistency of this equation and the stability of the observer can be used as a functional observability test

Du calcul opérationnel à l'opérateur de transfert

Le calcul opérationnel est un outil fondamental en Automatique. S'intéresser à son développement historique, qui est loin d'être linéaire, a peut-être des répercussions sur notre façon d'enseigner cette discipline. Quoi qu'il en soit, ces quelques notes permettent de situer rapidement les apports de beaucoup d'auteurs que nous connaissons et de préciser le rôle central joué par Oliver Heaviside

Some new standpoints in the design of asymptotic functional linear observers

The owl of Minerva spreads its wing only with the falling of the dusk. The aim of this work is to provide some new trends in the observation for linear systems. In the general framework of designing linear functional observers for linear systems the necessary and sufficient existence conditions are well known. Whether in the O'Reilly textbook or in the recently published ones on this topic, and, roughly speaking, the design methods can be categorized in two kinds. The first one is based on the solution of a Sylvester equation and a projection of the observed linear functional. The second one, based on the recent notion of functional observability, starts from the Darouach criterion which is an Popov-Belevitch-Hautus type one. Nevertheless, the main drawback of the deduced methods is that they cannot be used for linear time-varying systems. These models are of primary importance, for instance with linearization about a trajectory. Consequently, we cope with this problem by considering a new point of view for the design of linear functional observers. We see also that Darouach observers or Cumming-Gopinath observers are particular cases of the proposed methodology. For simplicity sake we suppose the system has no unknown inputs and is not described by a distributed parameters model as well. Nevertheless, these cases can be thought as possible extensions of the presented standpoints

Minimal single linear functional observers for linear systems

A constructive procedure to design a single linear functional observer for a time-invariant linear system is given. The proposed procedure is simple and is not based on the solution of a Sylvester equation or on the use of canonical state space forms. Both stable observers or fixed poles observers problems are considered for minimalit