Basilio Del-Muro-Cuellar

On the Control of Unstable First Order Linear Systems with Large Time Lag: Observer Based Approach

This work considers the problem of stabilization and control of a class of unstable first order linear systems subject to a relatively large input–output delay. As a first step, the conditions to ensure the stability of the system in closed loop with an output injection strategy are presented. In a second step, the stability conditions are used to design an observer-based scheme that provides a forward output estimation together with a feedback compensation to guarantee prediction convergence. The robustness of the overall observer-based strategy is analyzed when considering uncertainties on the magnitude of the time delay associated with the plant and the one considered on the design of the observer. A stability region as a function of these two time delays is obtained. The proposed prediction scheme is complemented by the use of a PI compensator to track step reference signals and to reject step disturbances.

Stabilisation and control of unstable first-order linear delay systems

This work considers the problem of stabilisation and control of first-order linear systems subject to input delay. As it is known, the stability analysis of this type of systems becomes difficult due to the term dead time considered. To solve the stabilisation problem as a first step are presented the conditions that assures the stability of the systems in closed-loop with a proportional feedback, these condition are derived with a novel methodology based on a discrete time approach. The stability conditions are used to design an observer (predicting) scheme that provides adequate convergent error. The proposed scheme results similar to the traditional Smith predictor that can be used on the case of stable systems. The observer scheme is complemented by the use of a PI compensator to follows step reference signals.

Stabilization Strategy for Unstable First Order Linear Systems with Large Time Delay

Abstract This work considers the problem of stabilization of a class of unstable first order linear systems subject to large input-output time delay. It is proposed a double output feedback one of then subject to time delay. Necessary and sufficient conditions are stated to guarantee the stability of proposed scheme based on two static gains. The stability conditions are derived by considering a discrete time approach, that under the assumption of a sampling time tending to zero, it is possible to infer the corresponding conditions for the continuous case.

Predictive current control of a four-wire, active power filter for an unbalanced utility load of metro railway

This paper presents a typical topology of medium-power, active power filter that utilizes a one-step ahead current controller to improve the power quality of a four-wire, unbalanced nonlinear load without using an additional switching limb to regulate the neutral current. In contrast to commonplace control techniques of shunt active filters, the one-step ahead strategy, or predictive control method of the presented circuit, determines the switching of the active filter and, thereby, the generation of its currents, such that the supply current waveforms become virtually sinusoidal waves, being its THD -% when the filter is operated with a 2kW load. The principle of operation of the switching control scheme is analysed, using a space vector technique for simple implementation together with a description of its practical development, showing experimental results obtained with a 2kW prototype.

Controlling spatial interacting populations

Prey-predator models can exhibit various forms of pattern formation. Spatio-temporal dynamics of prey-predator systems are relevant for several ecological applications. Spatial synchrony is one manifestation among a broader array of space-time patterns. In this work, we study the synchronisation of spatio-temporal dynamics via a control approach based on modelling error compensation ideas. Numerical simulations on two spatio-temporal models of prey-predator interactions, coupled and distributed parameter systems, are used to illustrate our findings.

CONTROL SCHEME BASED ON INTERNAL PREDICTION FOR UNSTABLE LINEAR TIME-DELAY SYSTEMS

Abstract This work considers the regulator problem for unstable linear input-delay systems. A discrete time control strategy intended to compensate the effects of the involved time delay and to stabilize the overall closed loop system, is designed. The proposed control strategy provides a prediction of “ all” the internal information in the system, which is used to solve the considered regulation problem in a similar way that it is used in a classical Smith predictor compensator

Model-based fault detection and identification: oriented sensor selection approach

This paper deals with continuous linear time-invariant systems and is focused on the model-based failure detection and identification problem, and more precisely, on the so-called residual generation problem. Our purpose is to present some new results concerning the practical situation arising when the problem cannot be solved using conventional tools for a given system. Thus, the residual generation must be done by choosing a new measured output matrix, that is, we are concerned with the development of sensor location methodologies that are oriented to guarantee the solution of the failure detection problem. Solvability conditions are presented and procedures for sensor location are developed. When the solvability conditions hold, the minimality of the associated residual generator is ensured. A geometric approach and the notions of fundamental and extended residual generation problems as stated by Massoumia are followed.