User`s guide

ord2
11-163
11ord2
Purpose Generate continuous second-order systems
Syntax [A,B,C,D] = ord2(wn,z)
[num,den] = ord2(wn,z)
Description [A,B,C,D] = ord2(wn,z) generates the state-space description (A,B,C,D) of
the second-order system
given the na tural frequency
wn ( ) and damping factor z ( ). Use ss to turn
this description into a state-space object.
[num,den] = ord2(wn,z) returns the numerat or a nd denominator of the
second-order transfer function. Use
tf to form the corresponding transfer
function object.
Example To generate an LTI model of the second-order transfer function with damping
factor and natural frequency , type
[num,den] = ord2(2.4,0.4)
num =
1
den =
1.0000 1.9200 5.7600
sys = tf(num,den)
Transfer function:
1
-------------------
s^2 + 1.92 s + 5.76
See Also rmodel, rss Generate random stable continuous models
ss Create a state-space LTI model
tf Create a transfer function LTI model
hs()
1
s
2
2ζω
n
s ω
n
2
++
---------------------------------------------=
ω
n
ζ
ζ
0.4
= ω
n
2.4 rad/sec.
=