| Titre : | Modern control systems |
| Auteurs : | Richard C. Dorf, Auteur ; Robert H. Brshop, Auteur |
| Type de document : | texte imprimé |
| Mention d'édition : | 9e éd |
| Editeur : | New Jersy : Prentice hall, 2001 |
| ISBN/ISSN/EAN : | 0‐13‐030660‐6 |
| Format : | 1 vol. (XXIII-831 p.) / ill. / 24 cm |
| Langues originales: | |
| Index. décimale : | 621 (Physique appliquée) |
| Catégories : | |
| Mots-clés: | Commande(système de) |
| Résumé : |
This edition of the book Modern Control Systems follows the same objective as the eight preceding editions: a textbook for introductory courses to control systems. The book is a good textbook for courses at an undergraduate level which focus on classical control theory, employing linear transforms. The strongest topics dealt within the book are signal flow graphs, the root locus method, and stability in the frequency domain. A strong plus for the book is the large number of examples, and exercises with an increasing degree of difficulty. The book covers most of the initial topics in control systems in a linguistic manner, there are very few proofs, even of the simplest results. It is very disappointing to find that topics like the state space modelling and the control system design in state space are not sufficiently discussed. This edition introduces three new features to improve student learning and lecturer access to book resources. These features are: (a) access via a website, to student and lecturer book related exercises, exam problems, MATLAB and Simulink files, and some additional written material; (b) the use of Simulink in two chapters to illustrate the analysis of feedback control systems, and the design of state variable feedback control systems; (c) two approaches, throughout the book, to introduce the student into real world design problems via a sequential design example for a hard disk, and a continuous design problem to employ the tools covered in each chapter. The book is organized in thirteen chapters which are: an introduction to control systems, mathematical models of systems, state variable models, feedback control systems characteristics, performance of feedback control systems, stability of linear feedback systems, root locus method, frequency response methods, stability in the frequency domain, design of feedback control systems, design of state variable feedback systems, robust control systems, and digital control systems. Chapter 1 is a very good introduction into the science and art of control systems. It gives a brief historical review of automatic control, and then illustrates the evolution of control systems until our days by providing examples of increasing complexity. The chapter also provides a vision of a probable future for this science and introduces the sequential design example which will be used throughout the book. Chapter 2 contains a brief introduction into the mathematical modelling of systems using differential equations, and the Laplace transform. In addition, block diagrams and signal‐flow graphs representation are also covered. An interesting feature of this chapter is the choice of examples. They are very illustrative of real world systems and increase in complexity and problem size as the chapter progresses, which is an incentive to keep on reading. Even though the chapter covers the two ways of modelling linear systems, there is no reference to the impulse response. This would be useful for more advanced studies in other topics of control systems, and the authors should consider including this topic in future editions. Chapter 3 presents the modelling of systems in state space. The chapter begins with state variables and the state equations and follows to signal flow graphs, and the transfer function and state equation relationship. The chapter also presents the solution of the state equations using the Laplace transform, the calculation of the state transition matrix using the same method, and the relationship between transfer function and state space. This chapter is a very basic introduction into state space methods. Chapter 4 is a review of characteristics of feedback control systems. It covers topics such as sensitivity, transient response, disturbance signals, steady state error and it contains a brief discussion on the cost of feedback.Chapter 5 covers the performance of control systems, mainly of second‐order systems, as most books do. It begins with a discussion of test input signals and then describes the response of second‐order systems. The chapter continues with the effects of increasing the order of the system by the addition of poles and zeroes, the estimation of the damping ratio, the analysis of pole‐zero location and its effect on the transient response, steady‐state error, performance indices and the simplification of linear systems. The discussion on performance indices leads to a set of tables for optimum response under different test inputs. I find this very handy for comparing the response of design examples with the optimum response using those indices in laboratory sessions.In Chapter 6 the authors introduce the concept of stability of linear feedback systems, mainly bounded‐input bounded‐output (BIBO) stability. The chapter contains brief discussion on the Routh–Hurwitz criterion and relative stability, and presents several examples to illustrate these concepts.The root locus method is presented in detail in Chapter 7. There are several topics dealt with in this chapter, regarding the use of the root locus method for analysis and design. Of particular interest is the discussion of three term controllers (PID). This chapter is probably the strongest of the whole book.Chapter 8 covers frequency response analysis methods, which include Bode diagrams, frequency response measurements, and performance specifications in the frequency domain.In Chapter 9, the Nyquist stability criterion is introduced. The chapter covers contours in the s‐plane, relative stability, time‐domain performance specified in the frequency domain, bandwidth, stability with time delays, and a discussion of PID controllers in the frequency domain. This chapter is beautifully written, with very illustrative examples, which enormously facilitate the student comprehension and use of the Nyquist criterion. Chapter 10 covers design of compensators. Some illustrative examples of design have been presented in previous chapters. This is a good way of helping the student to understand the underlying principles before he/she can design control systems with rock solid criteria. As stated previously, design in this book is mainly focused on the use of root locus and bode diagram for pole placement, so this chapter employs these tools to illustrate the design of phase‐lead, phase‐lag and phase‐lead‐lag controllers. The discussion on the use of the Bode diagram for compensation is perhaps not the strongest part of this book. Chapter 11, covers the design in state space. The chapter begins by introducing structural properties as controllability and observability, and then moves immediately into optimal control. Pole placement design methods are presented after this, and internal model control afterwards. Even though observability is discussed, there is no reference to observers and their design. Chapter 12 covers an introduction to robust control systems. The topics include analysis of robustness and the design of robust control systems with special emphasis in PID controllers. This chapter contains more examples than in previous chapters. Chapter 13 is an introduction to digital control systems, using transform methods. It includes topics as the Z‐transform, characteristics of sampled‐data feedback control systems, performance of sampled‐data second‐order systems, the use of the root‐locus and a brief discussion on the implementation of digital controllers. In general, I would strongly recommend this book for and introductory course to control systems, maybe for courses which do not require a strong background in control, but do require some knowledge. Due to the large number of topics covered, some have not been discussed deep enough; however the authors do let the reader know there is much more to what is presented. |
| Côte titre : | S8/59757-59758 |
Exemplaires (2)
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| S8/59757 | Livre | Bibliothèque centrale | Disponible |
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