On April 5, 2003, the University of Notre Dame hosted a one-day workshop in honor of Anthony N. Michel on the occasion of his retirement. Tony has been on the faculty at Notre Dame since 1984. He served as the Chair of the Department if Electrical Engineering from 1984 to 1988 and as the Matthew H. McCloskey Dean of Engineering from 1988 to 1998. Prior to that, he was on the faculty at Iowa State University for sixteen years and he was with General Motors' AC Electronics Division for six years.
Tony has been a pioneer in many research fields including large-scale dynamical systems, nonlinear systems stability analysis, recurrent neural networks, and recently, qualitative analysis of hybrid and discontinuous dynamical systems. He has also rendered extraordinary service to our community as General Chair of the IEEE Conference on Decision and Control, General Chair of the IEEE International Symposium on Circuits and Systems, Distinguished Lecturer of the IEEE Circuits and Systems Society, Editor of the IEEE Transactions on Circuits and Systems, President of the IEEE Circuits and Systems Society, and Vice-President of the IEEE Control Systems Society, just to name a few.
Tony has sustained a high level of significant research accomplishments, mostly in systems and controls, throughout his career. His work is characterized by great depth, as exemplified by his contributions to stability theory of dynamical systems, and by great breadth, as demonstrated by the wide range of problems that he addresses.
Tony has proved to be an excellent teacher and mentor, he has demonstrated to be an effective administrator, and he has rendered more than his share of service to his profession. He has received several lifetime career awards, including the 1995 Technical Achievement Award of the IEEE Circuits and Systems Society, the Distinguished Member Award of the IEEE Control Systems Society in 1998, the IEEE Centennial Medal in 1984, the 1999 Golden Jubilee Medal of the IEEE Circuits and Systems Society and the IEEE Third Millennium Medal in 2000.
The workshop provided a venue for researchers, colleagues, friends, and students to honor Tony's contributions while discussing contemporary issues in systems stability and control. Speakers at the workshop discussed topics ranging from stability analysis of dynamical systems to many application areas.
The workshop featured two keynote addresses and 16 technical presentations. The two keynote addresses were delivered by Irwin Sandberg and Alfred Fettweis. The 16 technical presentations were given by nine of Tony's friends and colleagues and by seven of Tony's former Ph.D. students. Due to the limited number of time slots available for technical presentations during the day of the workshop, not all papers accepted by the workshop were presented at the workshop. In particular, three of the papers included in this book were not presented at the workshop.
This book is divided into three parts. Part I contains seven chapters that deal with issues in stability analysis of dynamical systems. Part II contains six chapters about artificial neural networks as well as signal processing. Part III contains eight chapters that deal with power systems and control systems.
Chapter 1 introduces the wave-digital concepts and shows some interesting relationships to the relativity theory through some modifications to Newton's second law. Chapter 2 investigates the notion of time and establishes the so-called consistent Lyapunov methodology. The Physical Continuity and Uniqueness Principle and the Time Continuity and Uniqueness Principle are introduced as crucial for adequate modeling of physical systems. Chapter 3 develops a mathematical model for a multibody attitude system and provides asymptotic stability analysis results for such a system. The results of this chapter are motivated by a 1980 publication of R. K. Miller and A. N. Michel. Chapter 4 studies robust regulation of uncertain hybrid systems, provides a method for checking attainability, and applies the results to networked control systems. Chapter 5 uses Lyapunov stability theory to characterize and analyze swarm dynamics. In particular, it is shown that the swarm can achieve cohesion even under very noisy measurements. Chapter 6 establishes a necessary and sufficient stability condition for discrete time-varying uncertain delay systems and applies the result to communication network control problems. Chapter 7 conducts stability analysis and L/sub 2/ gain analysis for switched symmetric systems. It is established that when all subsystems are stable, the switched systems are exponentially stable under arbitrary switching.
Chapter 8 shows that some interesting families of shift-varying input-output maps can be uniformly approximated using Gaussian radial basis functions over an infinite time or space domain. Chapter 9 presents a generalized state-space formulation for blind source recovery where natural gradient neural learning is used. Various state-space demixing network structures are exploited to develop learning rules. Chapter 10 discusses the relationships, results, and challenges of various approaches under the theme of approximate dynamic programming. It also presents direct neural dynamic programming and its application to a challenging continuous state control problem of helicopter command tracking. Chapter 11 derives algorithms for estimating the aircraft state vector and for approximating the nonlinear forces and moments acting on the aircraft. Convergence of the present algorithms is shown using a Lyapunov-like function in this chapter. Chapter 12 proposes a novel evolutionary approach to multiobjective optimization problems called the dynamic multiobjective evolutionary algorithm. Qualitative analysis of the proposed algorithm is also performed. Chapter 13 introduces set-membership adaptive filtering which offers a viable alternative to traditional filtering techniques. Novel features of the set-membership adaptive filtering such as data-dependent selective update are highlighted.
Chapter 14 introduces trajectory sensitivity analysis techniques. Theoretical and practical applications of trajectory sensitivity analysis to power system dynamic security analysis are discussed in this chapter. Chapter 15 addresses the design of a corrective control strategy after large disturbances in large electric power systems where a system is separated into smaller islands at a slightly reduced capacity. Chapter 16 reviews control methods developed in the past for the purpose of maintaining the stability of the electric power generation-transmission-distribution grid. It also presents some new stability control possibilities. Chapter 17 uses data fusion modeling for groundwater systems identification. Kalman filtering methods are generalized using information filtering methods coupled with a Markov random field representation for spatial variations. Chapter 18 develops parameterizations of nominal (control, output) responses and provides results for feedback synthesis in an algebraic framework. Chapter 19 presents the adaptive dynamic programming algorithm and provides a complete proof for the adaptive dynamic programming theorem. Chapter 20 estimates the reliability of the supervisory control and data acquisition system used in offshore oil and gas platforms. Probabilistic risk assessment and fault tree analysis are used in obtaining these results. Chapter 21 develops call admission control algorithms for signal-to-interference ratio (SIR)-based power-controlled CDMA cellular networks based on calculated power control setpoints for all users in the network.
We would like to express our sincere thanks to the Department of Electrical Engineering, the Graduate School, and the Center for Applied Mathematics of the University of Notre Dame for providing the financial support that made this workshop possible. WE are grateful to all contributing authors for their timely and professional response to our numerous requests. Without their hard work, the workshop and this book would not have been possible.
Finally, we would like to thank Anthony N. Michel for his friendship, guidance, and support throughout the past many years. Please join us in wishing Tony the best of retirements!
Panos J. Antsaklis
Notre Dame, IndianaDerong Liu
Chicago, Illinois