LagLead Compensator Second Order Type 1, Step Response and Root Locus
Cuthbert Nyack
The applets here show the step response and Root Locus plot of a type 1 second
order system with LagLead Compensation.
The continuous system is discretised by the bilinear transform to get D(z) and a ZOH transformation of the
system transfer function.
eg parameters (2.0, 1.5, 1.5, 8.0, 1.0, 0.2, 1.0) show the response of the continuous and sampled uncompensated system.
(10.4, 1.5, 1.5, 8.0, 1.0, 0.2, 1.0) show the sampled uncompensated system becoming unstable at ~0.08 of the sampling frequency.
eg parameters (20.0, 1.5, 1.5, 8.0, 10.0, 0.01, 0.2) show
close correspondence between the cantinuous and sampled system with the
sampling time of 0.01s.
eg parameters (20.0, 1.5, 1.5, 8.0, 10.0, 0.2, 0.2) show
significant differences developing between the cantinuous and sampled system at small times with the
sampling time of 0.2s.
eg parameters (20.0, 1.5, 1.5, 8.0, 10.0, 1.18, 3.0) show the sampled
system becoming oscillatory at ~ 0.4 of the sampling frequency. For
K = 10 oscillation at half the sampling frequency occurs at Ts = 1.85s.
Applet below show an expanded view of the rhs of the above.
Gif images below show how the applets should appear.
Return to main page
Return to page index
COPYRIGHT © 2006 Cuthbert Nyack.