control.margin¶

control.
margin
(sysdata)¶ Calculate gain and phase margins and associated crossover frequencies
Parameters: sysdata (LTI system or (mag, phase, omega) sequence) –  sys : StateSpace or TransferFunction
 Linear SISO system
 mag, phase, omega : sequence of array_like
 Input magnitude, phase (in deg.), and frequencies (rad/sec) from bode frequency response data
Returns:  gm (float) – Gain margin
 pm (float) – Phase margin (in degrees)
 wg (float) – Frequency for gain margin (at phase crossover, phase = 180 degrees)
 wp (float) – Frequency for phase margin (at gain crossover, gain = 1)
 Margins are calculated for a SISO openloop system.
 If there is more than one gain crossover, the one at the smallest
 margin (deviation from gain = 1), in absolute sense, is
 returned. Likewise the smallest phase margin (in absolute sense)
 is returned.
Examples
>>> sys = tf(1, [1, 2, 1, 0]) >>> gm, pm, wg, wp = margin(sys)