Applet shows the frequency response(Nyquist plot) of second order type 0 and 1 systems with PD control.

The eg parameters (10.0, 1.0, 0.5, 0.0, 1.0, 3.0) show the Bode plot with P control and the resulting transient oscillations. The phase margin for type 0 ~ 40°, and for type 1 ~ 18°.

Parameters (2.0, 1.0, 0.5, 0.0, 1.0, 0.76 ) show the difference between types 0 and 1 on Nyquist plots and (2.0, 1.0, 0.5, 1.0, 1.0, 2.0) show what happens when the zero of the controller cancels one of the poles of the system.

Parameters (10.0, 1.0, 0.5, 0.4, 1.0, 4.5) show the phase margin for type 0 increasing to ~93° and for type 1 to ~ 74° with a reduction of the transient oscillations.

Gif image below show how the applet should appear.

COPYRIGHT © 2006 Cuthbert Nyack.