User`s guide

damp
11-52
11damp
Purpose Compute damping factors and natural frequencies
Syntax [Wn,Z] = damp(sys)
[Wn,Z,P] = damp(sys)
Description damp calculates the damping factor and natural frequencies of the poles of an
LTI model
sys. W hen invoked without lefthand arguments, a table of the
eigenvalues in increasing frequency, along with their damping factors and
natural frequencies, is displayed on the screen.
[Wn,Z] = damp(sys) returns column vectors Wn and Z containing the natural
frequencies and damping factors of the poles of
sys. For discrete-time
systems with poles and sample time ,
damp computes “equivalent”
continuous-time poles by solving
The values
Wn and Z are then relative to the continuous-time poles . Both Wn
and Z areemptyifthesampletimeisunspecified.
[Wn,Z,P] = damp(sys) returns an additional vector P containing the (true)
poles of
sys.NotethatPreturns the same values as pole(sys) (up to
reordering).
Example Compute and display the eigenvalues, natural frequencies, and damping
factors of t he continuous transfer function
Type
H = tf([2 5 1],[1 2 3])
Transfer function:
2 s^2 + 5 s + 1
---------------
s^2 + 2 s + 3
ω
n
ζ
z
T
s
s
ze
sT
s
=
s
Hs()
2s
2
5s 1++
s
2
2s3++
-------------------------------=