美国麻省理工大学：《航空系统的估计与控制》教学资源（讲义）Handout 3：Gain and Phase Margins for unstable

Handout 3: Gain and Phase Margins for unstable systems Eric feron Feb9,2004 Gain and Phase Margins exist for all systems, including the unstable ones Examplel: H(s) S Sketch the Bode plot(Gain and Phase) to the left of next page. Sketch root-locus to the right of the page, above the Nyquist plot Phase margin for K=-1.3 is

Handout 3: Gain and Phase Margins for unstable systems Eric Feron Feb 9, 2004 Gain and Phase Margins exist for all systems, including the 1 unstable ones Example1: H(s) = 1 − s/1 Sketch the Bode plot (Gain and Phase) to the left of next page. Sketch root­locus to the right of the page, above the Nyquist plot. Phase margin for K = −1.3 is 1

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H(s)= 3(s-0.1)(s2+0.2s+1) Figure 1: 1 cm of space 3

s2 + 0.2s + 3 H(s) = 3(s − 0.1)(s2 + 0.2s + 1) Figure 1: 1 cm of space 3