Nyquist Plot and Step Response for 5 Real Poles

Cuthbert Nyack

Applet shows the Nyquist plot for a system with 5 real poles.
This system is stable for K less than some value which depends on the pole locations and unstable at higher K'. Some example parameters for oscillation is shown below:-

(20.0, 1.0, 2.0, 3.0, 1.0, 1.0, 2.0, 1.0) oscillates at ~1rad/s.
(6.1, 1.0, 2.0, 1.0, 1.0, 1.0, 2.0, 0.82) oscillates at ~0.82rad/s.
(2.9, 1.0, 1.0, 1.0, 1.0, 1.0, 2.0, 0.72) oscillates at ~0.73rad/s.
(12.7, 1.0, 1.0, 1.0, 2.0, 2.0, 2.0, 0.94) oscillates at ~0.94rad/s.
(25.7, 1.0, 1.0, 2.0, 2.0, 2.0, 2.0, 1.08) oscillates at ~1.08rad/s.
(13.1, 1.0, 1.0, 2.0, 2.0, 2.0, 2.0, 0.64) has phase margin of 60° at ~0.64rad/s.

Gif image below shows how applet should appear.

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