Horacio J. Marquez

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In this paper, a robust controller design method is first formulated to deal with both performance and robust stability specifications for multivariable processes. The optimum problem is then dealt with using a loop-shaping H∞ approach, which gives a sub-optimal solution. Then a PID approximation method is proposed to reduce a high-order controller. The(More)
A version of the input-to-output stability (IOS) small gain theorem is derived for interconnections where the subsystems communicate asynchronously over multiple channels, and the communication is subject to multiple time-varying possibly unbounded communication delays. It is shown that a “multi-dimensional” version of the small gain condition guarantees(More)
proach, by R.J. Vaccaro: McGraw Hill Inc., ISBN 0-07-066781-0,455 pages, 1995. Reviewed by H.J. Marquez, Department of Engineering, Royal Roads Military College, FMO Victoria, B.C. VOS lB0, Canada. Digital Control is intended to serve as a text for a senior-level course on the analysis and design of digital control systems. There are many books on this(More)
The problem of stabilization of a force-reflecting telerobotic system in presence of time delay in the communication channel is addressed. We introduce an approach that is based on application of the input-to-output stability (IOS) small gain theorem for functional differential equations (FDEs). A version of the stabilization algorithm as well as its two(More)
A new approach for the design of robust H∞ filter for a class of discrete-time Lipschitz nonlinear systems with time-varying uncertainties is proposed based on linear matrix inequalities. Thanks to the linearity of the proposed LMIs in both the admissible Lipschitz constant of the system and the disturbance attenuation level, they can be simultaneously(More)
The problem of sensor fault diagnosis in the class of nonlinear Lipschitz systems is considered. A dynamic observer structure is used with the objective to make the residual converge to the faults vector achieving detection and estimation at the same time. It is shown that, unlike the classical constant gain structure, this objective is achievable by(More)
Criteria based on disturbance rejection and system robustness are proposed to assess the performance of PID controllers. A simple robustness measure is defined and the integral gains of the PID controllers are shown to be a good measure for disturbance rejection. An analysis of some well-known PID tuning formulas reveals that the robustness measure should(More)