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[EN] In this work the design of a linear observer–linear controller robust output feedback scheme is introduced for simultaneous trajectory tracking of position and force in fully actuated robot manipulators. The unknown state–dependent additive nonlinearity influencing the input–output description is modeled as an absolutely bounded “time–varying perturbation”. Generalized Proportional Integral (GPI) observers are shown to naturally estimate the unknown perturbation and a certain number of its time derivatives in an arbitrarily close manner. This information is used to advantage on the linear feedback controller design via a simple cancelation effort. To the best of the authors’ knowledge GPI observers have not been used before for robot force control. A comparison experimental analysis is presented to show the good performance of the proposed approach. [ES] En este trabajo se presenta el diseño de un controlador lineal robusto para el seguimiento simultáneo de posición y fuerza de robots manipuladores completamente actuados. Las no linealidades aditivas, posiblemente dependientes del estado, se modelan como una perturbación variante en el tiempo absolutamente acotada. Los observadores Proporcionales Integrales Generalizados (GPI, por sus siglas en inglés) son capaces de estimar esta perturbación desconocida y un cierto número de sus derivadas temporales de forma aproximada, aunque arbitrariamente cercana. Esta estimacińo del controlador para cancelar los efectos de los términos desconocidos. Hasta donde los autores saben, los observadores GPI no se han utilizado para el control de fuerza de robots manipuladores. Se presenta un análisis comparativo experimental para mostrar el buen desempeño del esquema propuesto Este trabajo se realizo en el marco del proyecto PAPIIT No.IN116314. Alejandro Gutiérrez–Giles agradece al Conacyt bajo la beca doctoral con CVU No. 334785. H. Sira–Ramírez agradece al Cinvestav (México) y al Conacyt bajo el proyecto No. 80777.

In this Letter, we propose an observer-based synchronization scheme for a class of chaotic systems. This class of systems are given by piecewise-linear dynamics. By using some properties of such systems, we give a procedure to construct the gain of the observer. We prove various stability results and comment on the robustness of the proposed scheme. We also present some simulation results. © 2002 Elsevier Science B.V. All rights reserved.

We consider the control of a class of chaotic systems, which covers the forced chaotic oscillators. We focus on two control problems. The first one is to change the dynamics of the system to a new one which exhibits a desired behavior, and the second one is the tracking problem, i.e., to force the solutions of the chaotic system to track a given trajectory. To solve these problems we use observers which could be used to estimate the unknown states of the system to be controlled. We apply the proposed method to the control of Duffing equation and the Van der Pol oscillator and present some simulation results. © 2001 Elsevier Science B.V.