Robust Multivariable Control Of Helicopters

Classical design and analysis techniques, many of which date back to the 1950's, are still predominantly used in the aerospace industry for the design and analysis of automatic flight control and aero-engine control systems. The continued success and popularity of these techniques is particularly impressive considering the radical advances in aircraft and spacecraft design and avionics technology made over this period. Clearly, an understanding of both the advantages and limitations of these methods is essential in order to properly evaluate the likely usefulness of more modern techniques for the design and analysis of aerospace control systems. One of the themes of this book is that the multivariable robust control methods it describes are logical and natural extensions of the more classical methods, and not replacements for them. It is assumed that readers of this publication are already familiar with classical flight control techniques. Emphasis is on the philosophy, advantages and limitations of the classical approach to flight control system design and analysis. Abstracted in Inspec

The underlying theory on which much modern robust and nonlinear control is based can be difficult to grasp. This volume is a collection of lecture notes presented by experts in advanced control engineering. The book is designed to provide a better grounding in the theory underlying several important areas of control. It is hoped the book will help the reader to apply otherwise abstruse ideas of nonlinear control in a variety of real systems.

Multivariable Feedback Control: Analysis and Design, Second Edition presents a rigorous, yet easily readable, introduction to the analysis and design of robust multivariable control systems. Focusing on practical feedback control and not on system theory in general, this book provides the reader with insights into the opportunities and limitations of feedback control. Taking into account the latest developments in the field, this fully revised and updated second edition: * features a new chapter devoted to the use of linear matrix inequalities (LMIs); * presents current results on fundamental performance limitations introduced by RHP-poles and RHP-zeros; * introduces updated material on the selection of controlled variables and self-optimizing control; * provides simple IMC tuning rules for PID control; * covers additional material including unstable plants, the feedback amplifier, the lower gain margin and a clear strategy for incorporating integral action into LQG control; * includes numerous worked examples, exercises and case studies, which make frequent use of Matlab and the new Robust Control toolbox. Multivariable Feedback Control: Analysis and Design, Second Edition is an excellent resource for advanced undergraduate and graduate courses studying multivariable control. It is also an invaluable tool for engineers who want to understand multivariable control, its limitations, and how it can be applied in practice. The analysis techniques and the material on control structure design should prove very useful in the new emerging area of systems biology. Reviews of the first edition: "Being rich in insights and practical tips on controller design, the book should also prove to be very beneficial to industrial control engineers, both as a reference book and as an educational tool." Applied Mechanics Reviews "In summary, this book can be strongly recommended not only as a basic text in multivariable control techniques for graduate and undergraduate students, but also as a valuable source of information for control engineers." International Journal of Adaptive Control and Signal Processing

Historically, one of the basic issues in control systems design has been robustness: the ability of a controlled plant to withstand variations in or lack of knowledge of its dynamics. Even if the dynamics of a system are accurately known for purposes of implementation, it is often desirable to design a control system based on a simplified model. Consequently it is essential to be able to guarantee a reasonable performance not only for the nominal plant, but also for its neighbouring perturbations: this is the issue of robustness. Since the beginning of this decade major advances have been made in this area, notably using the H -approach; this term is meant to cover the solution of sensitivity reduction, approximation and model reduction, robustness and related control design problems using the mathematics of Hardy spaces and related areas in Harmonic Analysis. This book contains the proceedings of the NATO Advanced Research Workshop on "Modelling, Robustness and Sensitivity Reduction in Control Systems", which was held at the University of Groningen, December 1986. Its aim was to explore the development of H -design techniques and its ramifications in Systems Theory in a unified and systematic way with the emphasis on recent advances and future directions in this fast developing area. In particular the following inter-related aspects were addressed: H -mathematical foundations, model approximation and robustness in control design, optimal sensitivity reduction, modelling and system identification and signal processing.

The main topic of this thesis is to exhibit how robust control techniques can be applied to real time systems. Presently, the control techniques used in the industry are very simple even when applied to complex systems; these techniques are intuitive and not necessarily systematic. Moreover, the notion of optimality of robustness is absent. Control design procedures are mostly based on SISO techniques, thus, overlooking the intrinsic multivariable aspect of the design that a MIMO system requires. In this thesis a modern control technique is presented to manipulate a 3DOF birotor helicopter in real time. The objective of this research is to demonstrate the performance of more efficient control algorithms to control these kinds of systems. The robust method proposed in this thesis is an H infinity controller which exhibits robustness to plant model uncertainties, and good disturbance and noise rejection.