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Emerald Group Publishing Limited
Copyright © 2009, Emerald Group Publishing Limited
Mechatronic Systems, Sensors, and Actuators: Fundamentals and Modeling
Article Type: Book review From: Sensor Review, Volume 29, Issue 1
The Mechatronics Handbook (2nd ed.),Robert H. Bishop,CRC Press,Boca Raton, FL,2007,$99.95,712 pp.,ISBN: 978-1-60456-315-3,web site: www.crcpress.com/shopping_cart/products/product_detail.asp?sku=9258& isbn=9780849392580&parent_id = &pc = ,
This book certainly appears to be comprehensive, a weighty tome containing contributions from 49 authors on every imaginable facet of the topic. But as a result it lacks a consistency of style and has no unified objective. The varied ingredients have been stirred together to make something of a Mulligatawny soup. Like the curate’s egg, parts of it are excellent.
I found it hard to understand the reasons for deciding on the order of the 21 chapters. The first four are obvious enough, rather superficial “scene setting” chapters with concept diagrams including the ubiquitous Venn-style map of the overlaps between electrical, mechanical and software engineering. But why throw in a chapter on nanotechnology before even the first mention of conventional sensors and actuators?
In Chapter 6, the theme seems to be breast-beating about how mechatronics should be taught, but without any regard for actual content. The Venn diagrams come thick and fast, but it is hard to penetrate talk of “the ability to synergistically combine knowledge and skills” to realise that an adept graduate should be able to trade a few watts of motor power against a slicker software algorithm.
The second section of ten chapters gives the appearance of an intention to get down to the nitty gritty. The first of these gives a rather perfunctory treatment to electromagnetic forces and kinematics (but with no clear mention of kinematic chains). I must admit that I had not previously been aware that the instability of static magnetic or electrical levitation had been announced by Earnshaw in 1829. Once again, the target of attention seems to be the Comb-drive MEMS actuator.
A chapter on structures and materials manages to combine the topics of deformable materials and Maxwell’s laws. In the days of metal typesetting, the compositor would have had to send out for more symbols for the partial-differential operator.
Chapter 9 promises to present ways to model mechanical systems, but degenerates into a treatise on bond graphs and causality, topics that are interesting in themselves but of little assistance if the aim is to steer the studies of undergraduates.
Chapters 10 and 11 at last start to attend to the needs of the undergraduate, with a useful but brief overview of fluid power that any electrical engineer can grasp and a panorama of electrical engineering that should illuminate any mechanical engineer.
I was a little surprised to meet a chapter on thermodynamics. It started humbly, with conversions between Fahrenheit and Celsius, but rapidly built up to entropy, exergy and other manifestations of the laws. If an appreciation of this subject can save us from being approached by proud inventors of perpetual motion machines, it will be well worth the study.
At last I reached a chapter on numerical simulation. This has long been an enthusiasm of mine. I am always keen to show students how easily the state variables of a dynamic system can be identified and their performance simulated with a few lines of computer code. (You might like to visit www.jollies.com) Imagine my disappointment when I found nothing more than some screenshots plugging a commercial package, requiring no more understanding than drag-and-drop.
Two more chapters on MEMS did not restore any belief that the book could support a mechatronics course. The section winds up with a philosophical discussion of the nature of analogies. Perhaps, the next section on sensors and actuators would have more to offer.
Chapter 17, with an overview of a variety of practical technologies for sensors and actuators, should surely be placed much earlier in such a book. On the other hand, the following chapter does not treat the fundamentals of time and frequency in any way that could underpin mechatronics. Instead of comparing state transition against transfer functions, as it should, it wanders-off into the accuracy of quartz oscillators and atomic clocks.
Chapter 19 is another of the “good bits,” but is all too brief. Resolution, sensitivity, linearity and accuracy are all treated in an intelligent way. The depredations of friction, backlash, saturation and dead-band are all given a mention, followed by a brief dose of classical second-order control theory.
Now things have taken a turn for the better. A multi-author chapter on sensors contains a wide-ranging overview, though perhaps the section on integrated micro-sensors is excessively concerned with their fabrication, rather than their use.
In its turn, a substantial Chapter 21 presents actuators of all shapes and sizes. But yet another extended treatment of MEMS brings the book to a close.
If you have a fascination with the applications of nanotechnology, then this is certainly the book for you. If you want to get some relief from a class of mechatronics students by giving them something instructive to read, then I am afraid that you must look elsewhere.
John BillingsleyUniversity of Southern Queensland, Australia