Automatic Control Systems

Abstract

This is the ninth edition of the text but the first with Farid Golnaraghi as the lead author. For this edition, we increased the number of examples, added MATLAB'" ' toolboxes, and enhanced the MATLAB GUI software, ACSYS. We added more computer-aided tools for students and teachers. The prepublication manuscript was reviewed by many professors, and most of the relevant suggestions have been adopted. In this edition, Chapters 1 through 4 are organized to contain all background material, while Chapters 5 through 10 contain material directly related to the subject of control. In this edition, the following materials have been moved into appendices on this book's Web site at www.wiley.com/college/golnaraghi. Appendix A: Elementary Matrix Theory and Algebra Appendix B: Difference Equations Appendix C: Laplace Transform Table Appendix D: z-Transform Table Appendix E: Properties and Construction of the Root Loci Appendix F: General Nyquist Criterion Appendix G: ACSYS 2008: Description of the Software Appendix H: Discrete-Data Control Systems In addition, the Web site contains the MATLAB files for ACSYS, which are software tools for solving control-system problems, and PowerPoint files for the illustrations in the text. The following paragraphs are aimed at three groups: professors who have adopted the book or who we hope will select it as their text; practicing engineers looking for answers to solve their day-to-day design problems; and, finally, students who are going to live with the book because it has been assigned for the control-systems course they are taking. To the Professor: The material assembled in this book is an outgrowth of senior-level control-system courses taught by the authors at their universities throughout their teaching careers. The first eight editions have been adopted by hundreds of universities in the United States and around the world and have been translated into at least six languages. Practically all the design topics presented in the eighth edition have been retained. This text contains not only conventional MATLAB toolboxes, where students can learn MATLAB and utilize their programming skills, but also a graphical MATLAB-based software, ACSYS. The ACSYS software added to this edition is very different from the software accompanying any other control book. Here, through extensive use of MATLAB GUI programming, we have created software that is easy to use. As a result, students will need to focus only on learning control problems, not programming! We also have added two new applications, SIMLab and Virtual Lab, through which students work on realistic problems and conduct speed and position control labs in a software environment. In SIMLab, students have access to the system parameters and can alter them (as in any simulation). In Virtual Lab, we have introduced a black-box approach in which the students iv 1 MATLAB " is a registered trademark of The Math Works. Inc. Preface v have no access to the plant parameters and have to use some sort of system identification technique to find them. Through Virtual Lab we have essentially provided students with a realistic online lab with all the problems they would encounter in a real speed- or positioncontrol lab—for example, amplifier saturation, noise, and nonlinearity. We welcome your ideas for the future editions of this book. Finally, a sample section-by-section for a one-semester course is given in the Instructor's Manual, which is available from the publisher to qualified instructors. The Manual also contains detailed solutions to all the problems in the book. To Practicing Engineers: This book was written with the readers in mind and is very suitable for self-study. Our objective was to treat subjects clearly and thoroughly. The book does not use the theorem-proof-Q.E.D. style and is without heavy mathematics. The authors have consulted extensively for wide sectors of the industry for many years and have participated in solving numerous control-systems problems, from aerospace systems to industrial controls, automotive controls, and control of computer peripherals. Although it is difficult to adopt all the details and realism of practical problems in a textbook at this level, some examples and problems reflect simplified versions of real-life systems.