Can two first order transfer functions be added together in matlab to make a second order transfer function
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As the title says is this possible I have
g=(31.2)/(155*s+1)
and
g1=(4)/(172*s+1)
if i then do
g2=(g+g1) does this give the correct second order tf
回答（3 个）
Yes, unlike Mischa said you do get a second order tf because g and g1 do not have a common denominator. The result is:
g2 =
5986 s + 35.2
---------------------
26660 s^2 + 327 s + 1
4 个评论
Mischa Kim
2014-2-4
Paul is correct. Of course, the order of the denominator determines the order of the system. Unless you have other effects (e.g. pole-zero cancellation).
Azzi Abdelmalek
2014-2-4
Mischa, when I read Paul's answer, something is wierd. Did I by accident, delete your answer?
Walter Roberson
2014-2-4
Is the numerator the one with 5986 s in it, or is the 124.8 that has no s in the numerator ?
Paul
2014-2-4
Depends on what you do. Add them and you get this one, multiply and you get the 124.8 one. In the question Daniel said he wanted to add them, but in a reply he said he wanted two transfer functions in series so you have to multiply.
Daniel
2014-2-4
0 个投票
1 个评论
Azzi Abdelmalek
2014-2-4
Daniel, If you want to add a comment, just click on [comment on this answer]
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2014-2-4
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