SYSTEM DYNAMICS & CONTROL
CHAPTER 4
TRANSFER FUNCTIONS
Dr. Vo Tuong Quan
HCMUT - 2011
Transfer Functions
Purpose of transfer function???
A block diagram composes of 3 components
Summing point
Function block
Pickoff point
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Transfer Functions
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Serial transfer functions
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Transfer Functions
Parallel transfer functions
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Transfer Functions
Transfer functions of feedback systems
Negative feedback
Unity Negative feedback
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Transfer Functions
Transfer functions of feedback systems
Positive feedback
Unity Positive feedback
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Transfer Functions
Moving a pickoff point behind a block
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Transfer Functions
Moving a pickoff point behind a block
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Transfer Functions
Moving a summing point behind a block
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Transfer Functions
Moving a summing point behind a block
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Transfer Functions
Interchange the position of two consecutive summing points
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Transfer Functions
Splitting the summing point
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Transfer Functions
Prohibit: Do not interchange the positions of a pickoff
point and a summing point
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Transfer Functions
Example 1
Find the equivalent transfer function of the following system
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Transfer Functions
Example 1: Solution
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Transfer Functions
Example 1: Solution
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Transfer Functions
Example 1: Solution
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Transfer Functions
Example 2
Find the equivalent transfer function of the following system
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Transfer Functions
Example 2: Solution
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