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Modeling and Analysis of Dynamic Systems

  1. Oct 7, 2003 #1

    Tom Mattson

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    This lonely little Forum hasn't seen much traffic, and I suspect it's because most of you don't know exactly what the field of Systems Engineering actually entails. Given the importance of "the systems approach" to modern engineering, I think a tutorial thread is in order.

    The discussion will be based on the book, Modeling and Analysis of Dynamic Systems, 2ed, by Close and Frederick, Houghton Mifflin, 1993.

    The topics in this introduction are going to be as follows:
    1. Introduction
    2. Translational Mechanical Systems
    3. Standard Forms for System Models
    4. Rotational Mechanical Systems
    5. Electrical Systems
    6. Analytical Solution of Linear Models
    7. The Laplace Transform
    8. Transfer Function Analysis
    9. Developing a Linear Model (from a nonlinear system)
    10. Electromechanical Systems
    11. Thermal Systems
    12. Hydraulic Systems

    And if I can figure out how to post diagrams online:
    13. Block Diagrams
    14. Feedback System Modeling and Design Tools
    15. Computer Analysis
  2. jcsd
  3. Oct 7, 2003 #2

    Tom Mattson

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    Section 1.1 Rationale

    The first thing to establish is why one would want to learn how to model dynamic systems, and why one would put such a diverse array of such systems all together in the same discussion.

    The first answer comes almost instantly upon asking the question: System models are valuable heuristic devices to estimating the response of engineering systems before they are built. This enables engineers to predict whether or not a system is up to the task for which it is designed before any precious material resources are committed to the project.

    Second, there is a need to educate engineers in the analysis of systems that components of different types, such as mechanical, electrical, thermal, and hydraulic (the four types that will be discussed in this thread). It is essential that a mechanical engineer, for instance, knows how his system will interface with electrical components, such as controllers. It may even be desirable that he learn how to design controllers himself. Neither does an electrical engineer work in a vacuum. Any electrical system generates heat, and the engineer designing the system must know how to include the thermal aspect of his system into the system model.

    Third, the equations that describe the different types of systems are strikingly similar, and learning how to analyze one type automatically gives the student the ability to analyze the others. For instance, consider the equation:


    The above equation models a damped mechanical oscillatorif:

    u=x, the displacement of the oscillator from equilibrium
    c1=m, the mass of the oscillator
    c2=b, the damping coefficient
    c3=k, the spring constant.

    The same models an LRC circuit if:

    u=q, the charge on the capacitor
    c1=L, the inductance
    c2=R, the resistance
    c3=1/C, the reciprocal of the capacitance.

    As we shall come to see, the above equation has analogs in rotational mechanical systems, thermal systems, and hydraulic systems as well.

    Given both the necessity of analyzing systems outside of one's explicit discipline, and of the mathematical similarity of such diverse system models, it only makes sense to include discussion of the various types all in one place.

    edit: fixed superscript bracket
  4. Apr 5, 2004 #3
    Recommend - Feedback Controls Systems Book

    Mr. Mattson,

    Can you recommend a good control systems book at the associate degree level.

    I have books by Ogatta, Dorf, Schaum's, Phillips & Nagel, etc.

    I am looking for book which describes controls at a basic level ... similar to the way cutnell & Johnson's Physics book 5th edition describes Physics.

    I do have a Master's Degree in Systems Engineering, but am trying to obtain a more fundamental understanding of the subject.

    Note: I have the 1st edition of Close and Frederick (1978), great book.

    Thanks for any input.
  5. Apr 9, 2004 #4

    I toy a bit with Earth science and climate. It occurs to me that those all react as physical systems, quite obviously, however I think there is too little modelling and analysis done.

    Let me give an example. Please take not of this link,http://jlevine.lbl.gov/BenStackintro.html [Broken]

    This is the system to analyse:

    Now let's http://jlevine.lbl.gov/BenStackCompare.html [Broken]
    Please check the graph

    We could consider the ocean being a lineair higher order open loop system, I guess with a very low eigen freqency. Now since the SPECMAP and Low lattitude stack represent the variations of the ocean surface, we could assume that they are the input forcing function of that ocean system, whilst the Benthic stack acts as the response or output part of that systems.

    With that in mind I think we see something that can't be, can it?
    Last edited by a moderator: May 1, 2017
  6. Apr 10, 2004 #5

    Tom Mattson

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    I think that Close and Frederick is the most suitable (I was lucky enough to take the course from Close himself). It is meant to be a first course in systems analysis, with differential equations as a co-requisite.
  7. Apr 13, 2004 #6
    This thread is right on!

    I'm an former EET student I like the systems approach to problems and simulation. I'm in majoring in physics now and I can see the need to grasp this subject. I was at the lab and I saw several positions offered in robotics astronomy and computational physics which depends heavily on simulation of dynamical systems.

    I have been working with STELLA by High Performance Systems. The book,Dynamic Modeling by Bruce Hannon and Matathias Ruth is a great. The book comes a run-time version of Stella.

    Another book is Modeling Engineering Systems; I forget the author. The book uses EXCEL to simulate systems up to 4th order.
  8. Apr 13, 2004 #7

    Tom Mattson

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    Hi, glad you think so. Now that there is some interest, I'll have to get back to presenting notes.
  9. Aug 9, 2011 #8
    hello Tom

    can u provide me some questions for chs 7 8 10?
    ive done the book but i want more practice
    thank you
  10. Aug 10, 2011 #9


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    good topic!
    and to continue I'd like to get some parts of the book, because I have an examanition comming and want to prepare myself as max as I can

    I have a mechanical background,so analysis os one big aspect of it,you're review made it look like this must be a grat book for analysis !

    so where could I geat parts/ebook ?

    thank you vm

  11. Aug 10, 2011 #10


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    Please note that the last post, before yours, in this thread is over 7yrs old. Tom is no longer active. Don't hold your breath waiting for a reply.
  12. Aug 10, 2011 #11


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    ow never watch the date, sorry :surprised
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