L1 Adaptive Control Theory

This book presents a comprehensive overview of the recently developed L1 adaptive control theory, including detailed proofs of the main results. The key feature of the L1 adaptive control theory is the decoupling of adaptation from robustness. The architectures of L1 adaptive control theory have guaranteed transient performance and robustness in the presence of fast adaptation, without enforcing persistent excitation, applying gain-scheduling, or resorting to high-gain feedback.

A systematic and unified presentation of the fundamentals of adaptive control theory in both continuous time and discrete time Today, adaptive control theory has grown to be a rigorous and mature discipline. As the advantages of adaptive systems for developing advanced applications grow apparent, adaptive control is becoming more popular in many fields of engineering and science. Using a simple, balanced, and harmonious style, this book provides a convenient introduction to the subject and improves one's understanding of adaptive control theory. Adaptive Control Design and Analysis features: Introduction to systems and control Stability, operator norms, and signal convergence Adaptive parameter estimation State feedback adaptive control designs Parametrization of state observers for adaptive control Unified continuous and discrete-time adaptive control L1+a robustness theory for adaptive systems Direct and indirect adaptive control designs Benchmark comparison study of adaptive control designs Multivariate adaptive control Nonlinear adaptive control Adaptive compensation of actuator nonlinearities End-of-chapter discussion, problems, and advanced topics As either a textbook or reference, this self-contained tutorial of adaptive control design and analysis is ideal for practicing engineers, researchers, and graduate students alike.

This book details the designing of hybrid control strategies for practical systems containing time varying uncertainties, disturbances, nonlinearities, unknown parameters, unmodelled dynamics, delays, etc., concurrently. In this book, the advantages of different controllers will be brought together to produce superior control performance for the practical systems. Being aware of the advantages of adaptive controller to tackle unknown constant, time varying uncertainties and time varying disturbances, a variant of adaptive controller, namely L1 adaptive controller, is hybridized with other strategies. In this book, to facilitate optimal parameter setting of the basic L1 adaptive controller, stochastic optimization technique will be hybridized with it. The stability of the optimization technique along with the controller will be guaranteed analytically with the help of spectral radius convergence. The proposed method exhibits satisfactory exploration and exploitation capabilities. Again, this book will throw light on tackling nonlinearities along with uncertainties and disturbances by hybridizing fuzzy logic with L1 adaptive controller. The performances of the designed controllers will be compared with different control methodologies to validate their effectiveness. The overall stability of the nonlinear system with the designed controller will be guaranteed with the help of fuzzy Lyapunov function to retain the zonal behaviour of the system. This fuzzy PDC-L1 adaptive controller is efficient to tackle nonlinearities and at the same time cancels unknown constant, time varying uncertainties and time varying disturbances adequately. This book will also contain four simulation case studies to validate fruitfulness of the designed controllers. To demonstrate the superior control ability of these controllers in tackling practical system, three experimental case studies will also be provided.

Adaptive control is no longer just an important theoretical field of study, but is also providing solutions to real-world problems. Adaptive techniques will transform the world of control. The leading world practitioners of adaptive control have contributed to this handbook which is the most important work yet in this field. Not only are techniques described in theory, but detailed control algorithms are given, making this a practical cookbook of adaptive control for both control professionals and practising engineers.The book presents the most advanced techniques and algorithms of adaptive control. These include various robust techniques, performance enhancement techniques, techniques with less a-priori knowledge, nonlinear adaptive control techniques and intelligent adaptive techniques. Each technique described has been developed to provide a practical solution to a real-life problem. This volume will therefore not only advance the field of adaptive control as an area of study, but will also show how the potential of this technology can be realised and offer significant benefits. Practical cookbook of adaptive control Contains important research

In Hubschraubern kommen mitunter aufwändige regelungstechnische Verfahren zum Einsatz, um ein intuitiv steuerbares und stabiles Verhalten der Maschine zu erzeugen. Klassische Ansätze in der Entwicklung setzen dabei auf Iterationen aus Systemidentifikation und Auslegung des Systems im Frequenzbereich. In diesem Buch wird vor dem Hintergrund der nur zu gerne unterschätzten Problematik der begrenzten Bandbreiten eine robuste adaptive Regelung eingeführt. Dazu wird ein hochfrequent-aktualisierender L1-adaptiver Regler entsprechend angepasst, ein neues adaptives Gesetz der Ausgangsrückführung eingeführt, eine neue Strategie zur Auslegung der Zustandsrückführung vorgestellt, und für den sicherheitskritischen Aspekt Effekte von Ungenauigkeiten im Rechentakt und von Sensorrauschen evaluiert. Während klassische Ansätze durch nichtlineare Optimierung weitestgehend automatisierbar sind und dennoch die Notwendigkeit wiederholter Flugtests nicht verhindern können, ist der L1-adaptive Regler bei entsprechendem Systemverständnis besonders geeignet, Entwicklungszeiten zu verkürzen. Strenge mathematische Beweise untermauern die Stabilität und Robustheit der eingeführten Algorithmen, wobei die Flugeigenschaften in einem Forschungssimulator verifiziert werden. Often, very complex controller techniques are applied to helicopters for generating an intuitively controllable and stable behavior of the aircraft. In legacy controllers, a number of iterations of system identification and loop shaping methods in frequency domain have to be conducted. In this book, a robust adaptive control theory is introduced, with the often underestimated fact of only limited available bandwidths in mind. To this end, the high-frequency adapting L1-adaptive controller is adjusted, a new adaptive law for output feedback is introduced, a new strategy for defining the design of a state feedback controller is proposed, and effects of uncertainties in the processor clock rate and of sensor noise are evaluated for taking the safety critical nature of the system into account. While legacy approaches can be automated by nonlinear optimization techniques and yet cannot eliminate the necessity of repeated flight tests, the L1-adaptive controller is particularly suitable to reduce development time, provided a sufficiently deep understanding of the system is available. Rigorous mathematical proofs substantiate the stability and robustness of the algorithms as shown, while performance and handling qualities are verified in a research simulator.

Adaptive control is the control method used by a controller which must adapt to a controlled system with parameters which vary, or are initially uncertain. An adaptive control system utilizes on-line identification of which either system parameter or controller parameter, which does not need a priori information about the bounds on these uncertain or time-varying parameters. These approaches consider their control design in the sense of Lyapunov. Besides, there are still some branches by combining adaptive control and other control methods, i.e., nonlinear control methods, intelligent control methods, and predict control methods, to name but a few. Addresses some original contributions reporting the latest advances in adaptive control. It aims to gather the latest research on state-of-the-art methods, applications and research for the adaptive control theory, and recent new findings obtained by the technique of adaptive control. Apparently, the book cannot include all research topics. Different aspects of adaptive control are explored. Chapters includes some new tendencies and developments in research on a adaptive formation controller for multi-robot systems; L1 adaptive control design of the the longitudinal dynamics of a hypersonic vehicle model; adaptive high-gain control of biologically inspired receptor systems; adaptive residual vibration suppression of sigid-flexible coupled systems; neuro-hierarchical sliding mode control for under-actuated mechanical systems; neural network adaptive PID control design based on PLC for a water-level system; and fuzzy-based design of networked control systems with random time delays and packet dropout in the forward communication channel--

This tutorial-style presentation of the fundamental techniques and algorithms in adaptive control is designed to meet the needs of a wide audience without sacrificing mathematical depth or rigor. The text explores the design, analysis, and application of a wide variety of algorithms that can be used to manage dynamical systems with unknown parameters. Topics include models for dynamic systems, stability, online parameter estimation, parameter identifiers, model reference adaptive control, adaptive pole placement control, and robust adaptive laws. Engineers and students interested in learning how to design, stimulate, and implement parameter estimators and adaptive control schemes will find that this treatment does not require a full understanding of the analytical and technical proofs. This volume will also serve graduate students who wish to examine the analysis of simple schemes and discover the steps involved in more complex proofs. Advanced students and researchers will find it a guide to the grasp of long and technical proofs. Numerous examples demonstrating design procedures and the techniques of basic analysis enrich the text.