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Fig.
7.9: View of the virtual-lab. |
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| System
description |
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| This
system is composed of a beam attached to a motor, and a ball placed on the
beam. The ball is allowed to roll with one degree of freedom along the length
of the beam. A diagram of this system is shown in Fig. 7.42. |
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Fig.
7.42: Schematic description of the system. |
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The
control goal is to place the ball at certain desired position ( )
, by changing the beam angle ( ).This
system type is often encountered in control applications. This unstable
system is a good example for learning how control techniques can be applied
to stabilize a plant. Two different control strategies have been implemented:
manual control and discrete PID control. |
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| Introduction |
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| The
virtual-lab introduction is shown in Fig. 7.43. |
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Fig.
7.43: Introduction of the virtual-lab. |
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| Model |
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| The
model that describes the ball movement has the following equations: |
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| The
discrete PID controller has two degree of freedom and anti-windup. The algorithm
of this controller can be found in “Computer Controlled Systems. Theory
and Design, Prentice Hall. Astrom, K. J. and Wittenmark, B. (1997)”. |
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| View |
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| The tree of elements is shown
in Fig 7.44. Open the virtual-lab and look at the properties of the tree
elements. |
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Fig.
7.44: View of the virtual-lab. |
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