Wassim M. Haddad

Georgia Institute of Technology, Atlanta, Georgia, United States

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Publications (504)523.71 Total impact

  • V.S. Chellaboina · Wassim M. Haddad
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    ABSTRACT: Partial stability theorems for nonlinear dynamical systems are presented and showed a unification between partial stability theory for autonomous systems and stability theory for nonlinear time-varying systems. This unification allows for time-varying stability theory to be presented as a special case of autonomous partial stability theory so that time-varying and time-invariant stability theory can be discussed in juxtaposition in a first course on nonlinear systems. Furthermore, partial stability theory is a fundamental topic of nonlinear system theory and should be part of a nonlinear control course in its own right.
    No preview · Article · Jun 2003 · IEEE control systems
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    VijaySekhar Chellaboina · Sanjay P. Bhat · Wassim M. Haddad
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    ABSTRACT: In this paper we develop an invariance principle for dynamical systems possessing left-continuous flows. Specifically, we show that left-continuity of the system trajectories in time for each fixed state point and continuity of the system trajectory in the state for every time in some dense subset of the semi-infinite interval are sufficient for establishing an invariance principle for hybrid and impulsive dynamical systems. As a special case of this result we state and prove new invariant set stability theorems for a class of nonlinear impulsive dynamical systems; namely, state-dependent impulsive dynamical systems. These results provide less conservative stability conditions for impulsive systems as compared to classical results in the literature and allow us to address the stability of limit cycles and periodic orbits of impulsive systems.
    Full-text · Article · May 2003 · Nonlinear Analysis
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    Wassim M. Haddad · Tomohisa Hayakawa · James M. Bailey
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    ABSTRACT: Non-negative and compartmental dynamical system models are composed of homogeneous interconnected subsystems or compartments which exchange variable non-negative quantities of material with conservation laws describing transfer, accumulation, and elimination between the compartments and the environment. These models are widespread in biological and physiological sciences and play a key role in understanding these processes. In this paper, we develop a direct adaptive control framework for linear uncertain non-negative and compartmental systems. The proposed framework is Lyapunov-based and guarantees partial asymptotic set-point regulation; that is, asymptotic set-point stability with respect to part of the closed-loop system states associated with the plant. In addition, the adaptive controller guarantees that the physical system states remain in the non-negative orthant of the state space. Finally, a numerical example involving the infusion of the anesthetic drug propofol for maintaining a desired constant level of depth of anesthesia for non-cardiac surgery is provided to demonstrate the efficacy of the proposed approach. Copyright © 2003 John Wiley & Sons, Ltd.
    Full-text · Article · Apr 2003 · International Journal of Adaptive Control and Signal Processing
  • VS Chellaboina · Wassim M. Haddad
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    ABSTRACT: Not Available
    No preview · Article · Apr 2003 · IEEE Transactions on Automatic Control
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    ABSTRACT: A direct robust adaptive control framework for nonlinear uncertain systems with constant linearly parameterized uncertainty and nonlinear state-dependent uncertainty is developed. The proposed framework is Lyapunov-based and guarantees partial asymptotic robust stability of the closed-loop system; that is, asymptotic robust stability with respect to part of the closed-loop system states associated with the plant. Finally, a numerical example is provided to demonstrate the efficacy of the proposed approach.
    Full-text · Article · Mar 2003 · Automatica
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    Simon Hsu-Sheng Fu · Wassim M. Haddad
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    ABSTRACT: Dr. Wassim M. Haddad received the B.S., M.S., and Ph. D. degrees in mechanical engineering from Florida Institute of Technology, Melbourne, FL in 1983, 1984, and 1987, respectively, with specialization in dynamical systems and control. From 1987 to 1994 he served as a consultant for the Structural Controls Group of the Government Aerospace Systems Division, Harris Corporation, Melbourne, FL. In 1988 he joined the faculty of the Mechanical and Aerospace Engineering Department at Florida Institute of Technology where he founded and developed the Systems and Control Option within the graduate program. Since 1994 he has been a member of the faculty in the School of Aerospace Engineering at Georgia Institute of Technology where he holds the rank of Professor. Dr. Haddad's research contributions in linear and nonlinear dynamical systems and control are documented in over 370 archival journal and conference publications. Among these contributions are the statespace formulation of mixed H2/H∞ mixed H2/∞ control, fixed-structure control, and multivariable generalizations of absolute stability theory using parameterized Lyapunov functions to capture phase information in robust control. His recent research is concentrated on nonlinear robust and adaptive control, saturation control, hierarchical nonlinear switching control, hybrid and impulsive control for nonlinear systems with combined logical and continuous processes, and nonlinear analysis and control for biological and physiological systems. Dr. Haddad is an NSF Presidential Faculty Fellow, a member of the Russian Academy of Nonlinear Sciences, and a coauthor of the book Hierarchical Nonlinear Switching Control Design with Applications to Propulsion Systems (Springer-Verlag, 2000).
    Preview · Article · Feb 2003 · Asian Journal of Control
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    Wassim M. Haddad
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    ABSTRACT: The authors proposed the development of a general multiechelon hierarchical nonlinear switching control design framework that minimizes control law complexity subject to the achievement of control law robustness. In particular, a unified dynamical systems framework for a general class of systems possessing left-continuous flows was developed. This report also discusses hybrid control, impulsive dynamical systems, nonnegative dynamical systems, compartmental systems, nonlinear switching control, and adaptive control. Areas of application for these control systems include biological systems, physiological systems, pharmacological systems, ecological systems, vibration control of aerospace structures, spacecraft stabilization, and control of combustion in jet engines. ( 7 figures, 125 refs.)
    Preview · Article · Feb 2003
  • W.M. Haddad · T. Hayakawa · J.M. Bailey
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    ABSTRACT: The potential clinical applications of adaptive control for pharmacology in general, and anesthesia and critical care unit medicine in particular, are clearly apparent. Specifically, monitoring and controlling the depth of anesthesia in surgery is of particular importance. Nonnegative and compartmental models provide a broad framework for biological and physiological systems, including clinical pharmacology, and are well suited for developing models For closed-loop control of drug administration. In this paper, we develop a direct adaptive control framework for nonlinear uncertain nonnegative and compartmental systems. The proposed framework is Lyapunov-based and guarantees partial asymptotic set-point regulation; that is, asymptotic set-point regulation with respect to part of the closed-loop system states associated with the plant. In addition, the adaptive controller guarantees that the physical system states remain in the nonnegative orthant of the state space. Finally, a numerical example involving the infusion of the anesthetic drug midazolam for maintaining a desired constant level of depth of anesthesia for noncardiac surgery is provided to demonstrate the efficacy of the proposed approach.
    No preview · Conference Paper · Feb 2003
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    ABSTRACT: Nonnegative and compartmental dynamical system models are widespread in biological, physiological, and ecological sciences and play a key role in understanding these processes. In the specific field of pharmacokinetics involving the study of drug concentrations (in various tissue groups) as a function of time and dose, nonnegative and compartmental models are vital in understanding system wide effects of pharmacological agents. Since drug concentrations are often assumed to monotonically decline after discontinuation of drug administration, standard pharmacokinetic modeling may ignore the possibility of system oscillation. However, nonnegative and compartmental system models may exhibit non-monotonic solutions resulting in differences between model predictions and experimental data. In this paper, we present necessary and sufficient conditions for identifying nonnegative and compartmental systems that only admit nonoscillatory and monotonic solutions.
    No preview · Conference Paper · Jan 2003
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    W.M. Haddad · T. Hayakawa · J.M. Bailey
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    ABSTRACT: Nonnegative and compartmental dynamical system models are composed of homogeneous interconnected subsystems or compartments which exchange variable nonnegative quantities of material with conservation laws describing transfer, accumulation, and excretion between the compartments and the environment. These models are widespread in biological and physiological sciences and play a key role in understanding these processes. In this paper, we develop a direct adaptive control framework for linear uncertain nonnegative and compartmental systems. The proposed framework is Lyapunov-based and guarantees partial asymptotic set-point regulation; that is, asymptotic set-point regulation with respect to part of the closed-loop system states associated with the plant. In addition, the adaptive controller guarantees that the physical system states remain in the nonnegative orthant of the state space. Finally, the proposed approach is used to control the infusion of the anesthetic drug propofol for maintaining a desired constant level of depth of anesthesia for noncardiac surgery.
    Full-text · Conference Paper · Jan 2003
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    Wassim M. Haddad · Joseph R. Corrado · Alexander Leonessa
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    ABSTRACT: We develop linear fixed-order (i.e., full and reduced order) pressure rise feedback dynamic compensators for axial flow compressors with throttle valve actuation. Unlike the nonlinear static controllers proposed in the literature possessing gain at all frequencies, the proposed dynamic compensators explicitly account for compressor performance versus sensor accuracy, compressor performance versus processor throughput, and compressor performance versus disturbance rejection. Furthermore, the proposed controller is predicated on only pressure rise measurements, providing a considerable simplification in the sensing architecture over the bifurcation-based and backstepping controllers proposed in the literature
    Full-text · Article · Oct 2002 · IEEE Transactions on Control Systems Technology
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    ABSTRACT: The pole-sensitivity approach is a general method for analyzing the stability of the discrete-time control system with a finite wordlength (FWL) implemented digital controller. It leads to a non-smooth and non-convex optimization framework, where an optimal controller realization can be designed by maximizing some stability related measure. In this contribution, a new stability related measure is derived, which is more accurate in estimating the closed-loop stability robustness of an FWL implemented controller than the existing measures of pole-sensitivity analysis. This improved stability related measure provides a better criterion to find the optimal FWL realizations for a generic controller structure that includes output feedback and observer-based controllers. An efficient global optimization strategy called the adaptive simulated annealing (ASA) is adopted to solve for the resulting optimization problem. A numerical example is included to verify the theoretical analysis and to illustrate the design procedure.
    No preview · Article · Jun 2002
  • V. Chellaboina · W. M. Haddad
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    ABSTRACT: The paper derives guaranteed gain, sector and disk margins for discrete-time nonlinear optimal and inverse optimal regulators that minimize a nonlinear–non-quadratic performance criterion. The proposed results provide a generalization of the classical discrete-time, linear–quadratic optimal regulator gain and phase margins.
    No preview · Article · Jun 2002 · International Journal of Systems Science
  • Wassim M. Haddad · Tomohisa Hayakawa
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    ABSTRACT: A direct adaptive non-linear control framework for multivariable non-linear uncertain systems with exogenous bounded disturbances is developed. The adaptive non-linear controller addresses adaptive stabilization, disturbance rejection and adaptive tracking. The proposed framework is Lyapunov-based and guarantees partial asymptotic stability of the closed-loop system; that is, asymptotic stability with respect to part of the closed-loop system states associated with the plant. In the case of bounded energy L2 disturbances the proposed approach guarantees a non-expansivity constraint on the closed-loop input–output map. Finally, several illustrative numerical examples are provided to demonstrate the efficacy of the proposed approach. Copyright © 2002 John Wiley & Sons, Ltd.
    No preview · Article · Mar 2002 · International Journal of Adaptive Control and Signal Processing
  • W.M. Haddad · S.G. Nersesov · V.S. Chellaboina
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    ABSTRACT: One of the most fundamental results in analyzing the stability properties of periodic orbits and limit cycles of dynamical systems is Poincare's theorem. The proof of this result involves system analytic arguments along with the Hartman-Grobman theorem. In this paper, using the notions of stability of sets, we construct lower semicontinuous Lyapunov functions to provide a Lyapunov function proof of Poincare's theorem.
    No preview · Conference Paper · Feb 2002
  • J.R. Corrado · W.M. Haddad
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    ABSTRACT: In this paper we explore the performance improvements that can be achieved by using multi-objective optimization. Specifically, we optimize a convex combination of a guaranteed cost bound and the nominal H<sub>2</sub> cost to improve performance over standard robust control designs. In those standard designs, performance degrades as robustness levels are increased. However, once we have designed a controller with a desired robustness level, applying the multi-objective optimization can enhance performance levels while still maintaining the original guaranteed robustness level. This procedure is demonstrated on several numerical examples.
    No preview · Conference Paper · Feb 2002
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    ABSTRACT: Poincare's method is well known for analyzing the stability of continuous-time dynamical systems with periodic solutions by studying the stability properties of a fixed point as an equilibrium point of a discrete-time system. In this paper we generalize Poincare's method to dynamical systems possessing left-continuous flows to address the stability of limit cycles and periodic orbits of left-continuous, hybrid, and impulsive dynamical systems.
    Preview · Conference Paper · Feb 2002
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    W.M. Haddad · V. Chellaboina · S.G. Nersesov
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    ABSTRACT: Nonnegative and compartmental dynamical systems are governed by conservation laws and comprise homogeneous compartments which exchange variable nonnegative quantities of material via intercompartmental flow laws. These systems typically possess hierarchical (and possibly hybrid) structures and are remarkably effective in capturing the phenomenological features of many biological and physiological dynamical systems. We develop several results on stability and dissipativity of hybrid nonnegative and compartmental dynamical systems.
    Preview · Conference Paper · Feb 2002
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    Wassim M. Haddad · Takeshi Hayakawa · A. Leonessa
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    ABSTRACT: A direct adaptive nonlinear control framework for discrete-time multivariable nonlinear uncertain systems with exogenous bounded disturbances is developed. The adaptive nonlinear controller addresses adaptive stabilization, disturbance rejection, and adaptive tracking. The proposed framework is Lyapunov-based and guarantees partial asymptotic stability of the closed-loop system; that is, asymptotic stability with respect to part of the closed-loop system states associated with the plant. Finally, two illustrative numerical examples are provided to demonstrate the efficacy of the proposed approach.
    Full-text · Conference Paper · Feb 2002
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    Wassim M. Haddad · VijaySekhar Chellaboina
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    ABSTRACT: A nonlinear dynamic compensator framework for Hammerstein systems with passive nonlinear dynamics is proposed. For this class of systems controlled by passive nonlinear dynamic compensators we prove the global closed-loop stability by modifying the dynamic compensator to include a suitable input nonlinearity. The proof of this result is based on the dissipativity theory and shows that the nonlinear controller modification counteracts the effects of the input nonlinearity by recovering the passivity of the plant and the compensator
    Full-text · Article · Nov 2001 · IEEE Transactions on Automatic Control

Publication Stats

8k Citations
523.71 Total Impact Points

Institutions

  • 1993-2015
    • Georgia Institute of Technology
      • School of Aerospace Engineering
      Atlanta, Georgia, United States
  • 2009
    • Indian Institute of Technology Madras
      Chennai, Tamil Nādu, India
  • 1987-2007
    • Florida Institute of Technology
      • Department of Mechanical and Aerospace Engineering
      Melbourne, Florida, United States
  • 2006
    • Villanova University
      • Department of Mechanical Engineering
      노리스타운, Pennsylvania, United States
  • 2000-2004
    • University of Missouri
      • Department of Mechanical and Aerospace Engineering
      Columbia, MO, United States
  • 2001
    • Florida Atlantic University
      Boca Raton, Florida, United States
  • 1999
    • Florida State University
      • Department of Mechanical Engineering
      Tallahassee, FL, United States
  • 1994
    • Massachusetts Institute of Technology
      • Department of Aeronautics and Astronautics
      Cambridge, MA, United States
    • Stanford University
      • Department of Aeronautics and Astronautics
      Stanford, CA, United States
  • 1988-1994
    • Harris Corporation
      Melbourne, Florida, United States