Page 159 - MATLAB an introduction with applications

144 ——— MATLAB: An Introduction with Applications

Example E3.4: Determine the pole locations for the unity feedback system shown below using MATLAB.

150
() =
Gs
(s + 5)(s + 7)(s + 9)(s + 11)
Solution:
>> %MATLAB Program
>> numg =150

numg = 150
>> deng =poly ([–5 –7 –9 –11]);
>> ‘G(s)’
ans =
G(s)
>> G=tf (numg, deng)
Transfer function:
150
∧
∧
∧
s 4 + 32 s 3 + 374 s 2 + 1888 s + 3465
>> ‘Poles of G(s)’
ans =
Poles of G(s)
>> pole (G)
ans =
–11.0000
–9.0000
–7.0000
–5.0000
>> ‘T(s)’
ans =
T(s)
>> T=feedback (G, 1)
Transfer function:
150
∧
∧
∧
s 4 + 32 s 3 + 374 s 2 + 1888 s + 3615
>> pole (T)
ans =
–10.9673+1.9506i
–10.9673–1.9506i
–5.0327+1.9506i
–5.0327–1.9506i

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