Specifications

allmargin
16-12
16allmargin
Purpose Compute all crossover frequencies and corresponding stability margins
Syntax S = allmargin(sys)
Description allmargin computesthe gain,phase,and delaymarginsandthe corresponding
crossoverfrequenciesof the SISO open-loopmodel
sys.allmargin isapplicable
to any SISO model, including models with delays.
The output
S is a structure with the following fields:
• GMFrequency — All -180 degree crossover frequencies (in rad/sec)
• GainMargin — Corresponding gain margins, defined as 1/G where G is the
gain at crossover
• PMFrequency — All 0 dB crossover frequencies in rad/sec
• PhaseMargin — Corresponding phase margins in degrees
• DMFrequency and DelayMargin — Critical frequencies and the
corresponding delay margins. Delay margins are given in seconds for
continuous-time systems and multiples of the sample time for discrete-time
systems.
• Stable — 1 if the nominal closed-loop system is stable, 0 otherwise.
See Also ltimodels Help on LTI models
ltiview LTI system viewer
margin Gain and phase margins for SISO open-loop systems