Modern Control Systems (9th Edition) (ISBN 0130306606)

Depends on what you are looking for:
If you want to learn about Modern Control Systems the first time around then use a book written by Ogata, Kuo or Nise. These three authors have some of the best books on this subject that you will ever see. As for this book GOOD: The Matlab part of the book I would give 4 stars. It is pretty good and lets you get acquainted with the control toolbox. There are a wide variety of problems in the book and it has a lot of design problems for the reader. Problems include exercise problems, regular problems (beats me why he didn't put them together), advance problems and Matlab Problems. If you already know the subject then it could possibly be a good design book. BAD: Worst book I have ever read. This book offers some of the worst explanations I have ever seen in a book. It is nearly impossible to do the problems with the information given to you. Reading the book is like solving an exercise problem in itself. A lot of times the math is skipped so you have no idea how he got to the answer. While other books happened to spend 4 pages on a topic, Dorf managed to compress it into a useless paragraph. Also, Dorf expects you to clairvoyantly know what a definition is. When reading through a chapter he talks about something without telling you what it is. Somehow he expected you to know that at the end of the chapter, AFTER you've read everything he'll give you a definition list. Very few exercise problems have answers to them so if you are doing something wrong then you will not know. If you are looking for self-study from this book then start crying now because you will throw over 100 bucks in the garbage. The most definitively annoying thing about the book is how it references other books. Dorf commonly gives you a sentence on a topic and then references the sentence to another book. Those sentences are meaningless and explain nothing, which gave me the impression that I was supposed to go to one of the hundreds of referenced books to learn what he was talking about. IN SUM: The only people who will like this book are the ones who already know the subject. I found that after I read Modern Control Engineering by Ogata and understood the subject, I appreciated a FEW of the examples Dorf gave, even though I could find a slew of books that could cover that material better. If you are a teacher looking to make this your class's book, reconsider because your students will not learn the subject.

...:
Not once in all my university courses have I had a text that is this frustrating. It presents results without justification, it uses examples with no explanation, it weighs a ton and yet refers you to their website on every other page because the necessary material isn't even included in the book. If you have a university/college course that requires this text PLEASE do your whole campus a favor and tell the prof. to change to something else.

Modern Control Systems Using Classical Methods:
I am a practicing systems engineer in industry. My company, Transpower Corporation, writes custom and commercial engineering and accounting software. Over the years I've purchased many, many control engineering books, including the fourth and seventh editions of Prof. Dorf's Modern Control Systems. At my request, Dr. Dorf sent me the solutions manual. Unlike the other reviewers here, I find the book to be easy reading, particularly because of the many fine illustrations which add immensely to the clarity of presentation. The 800 problems contained in the book cover a very wide range of modern real-life control systems; they are vastly better than the problems contained in any other control book I've purchased. The book is very strong on classical methods, but rather weak on the so-called "modern methods." I happen to prefer the Internal Model Principle and even wrote a software package, Optimal Control Designer, to make that method easy to apply. Unfortunately Dorf treats the Internal Model Principle only briefly. The same goes for LQR and other optimization methods. On the other hand, ITAE and deadbeat systems are treated rather well. The use of MATLAB in the book and problems is very welcome. However, Simulink is not used. Those of us in industry are likely to use Simulink to simulate a proposed system to death before production. Hopefully the forthcoming 10th edition will include example applications using Simulink. One other deficiency is the lack of treatment of real-time computer control (for example using Real-Time Workshop and Real-Time Windows Target). I haven't yet found any text on control which goes into any detail on this subject--those of us in industry would very much like such a text. In summary I highly recommend this book. It's worth the price just for the spectacular set of end-of-chapter problems.

Makes a nice paper weight:
That book was required for my course, and that was the $150.00 I wish I spent on something else. It still looks like new, because I almost never reffered to it. I found better explained info on the internet. I flanked the course the first time, then I found othe sources of information. Never, EVER buy this book, mine is alredy in the garbage.

34 Years Ago, This Was a Book to Save:
Yet, in a point of irony, somewhere, sometime, in my various consulting travels, Dorf's textbook was misplaced. The quality of a textbook on any technical book for students or practising professionals is critical mainly if the person doesn't use other humans to learn for them. Many organizations expect or demand their employees to use others for this purpose. This approach was in dire countpoint to my own approach: read the book, do the problems BEFORE class and almost never ask questions of profs. Sadly, self sufficiency in the large corporations is often seen either as a weakness or a threat. Anyway, three years ago I took the old version out of a library, and it was just as clear to me then as it had been 30 years before. I bought a companion volume to make connections with MatLab and other software tools. Here's a suggestion for those who don't like a book: do not use that book alone! If the book which you do not like or find incomprehensible is a textbook, then register your complaints, but find another, better book to complement the one you cannot use easily. 35 years ago I had a textbook on differential equations which was extremely difficult - I was not used to difficulties in math at all - and which caused many very talented student engineers, physicist, and mathematicians to bail. ONE book literally shattered their confidence after a lifetime of As and success. I took that book and copied every page of it by hand. If I still didn't understand the text well enough to solve the problems (this text had few examples, if any, and was even on the thin side for leavening text with equations!)... I copied the chapter again! And if I still didn't understand it, a third time! What I then knew: the DiffEq book was great if you wanted to be a theroetical mathematician, but not if you wanted to learn diff eq for anything else. So, it was a brilliant book, it really stretched me out... but of course, the next text in the math for engineers sequence was Kresyzig, which turned diff eq into relatively simple algebra with Laplace transforms... so, other than as a great intellectual 'gut check' the diff eq book was not for someone with five other problems courses to digest. What I know now: if one book isn't enough, then you get another from a library or wherever. Copying chapters of a math book letter for letter is not an efficient way to acquire knowledge or skills. A pointed question for students might be to ask their prof or TA if they used that textbook, AND, if they truly understand it easily. If memory serves, they really like students who find other resources to learn material: ask about other books - hell, they may even loan one to you!