WOLFRAM|DEMONSTRATIONS PROJECT

Bode, Nyquist, and Nichols Diagrams of Second-Order Systems

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Bode diagram
Nyquist diagram
Nichols diagram
process gain K
1
response time τ
1
damping coefficient ζ
1
Consider a second-order system given by the transfer function:
G(s)=
K
p
2
τ
2
s
+2ζτs+1
,
where
ζ
is the damping coefficient,
τ
is the response time, and
K
p
is the process steady-state gain.
This Demonstration plots the Bode, Nyquist, and Nichols diagrams for user-set values of the parameters
ζ
,
K
p
, and
τ
. Different behaviors are observed for
0≤ζ<1
(underdamped or oscillating system),
ζ=1
(critically damped system), and
ζ>1
(overdamped system).