ece580 lecture 18

ece580 lecture 18 - Nov. 10, 2011 Feedback Control Systems...

Info iconThis preview shows pages 1–12. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Nov. 10, 2011 Feedback Control Systems (I) Douglas Looze 1 Lecture 18 ECE 580 Feedback Control Systems (I) MIE 444 Automatic Controls Doug Looze Nov. 10, 2011 Feedback Control Systems (I) Douglas Looze 2 Announce PS 6 due next Thursday Nov. 10, 2011 Feedback Control Systems (I) Douglas Looze 3 Last Time Bode plots constructed by adding individual factors ( 29 ( 29 ( 29 1 1 m n zi pi i i G j q j q j = = =- R R R ( 29 ( 29 ( 29 1 1 log log log log m n zi pi i i G j K q j q j = = = +- ( 29 ( 29 ( 29 1 1 m zi i n pi i q s G s K q s = = = Nov. 10, 2011 Feedback Control Systems (I) Douglas Looze 4 Construction Add asymptotes Sketch plot Use computer (Matlab) for detail RHP poles/zeros Gain same as LHP factor Phase Zero: mirrored Pole: + mirrored Interpretation Steady-state of closed-loop Gain/phase margins Nov. 10, 2011 Feedback Control Systems (I) Douglas Looze 5 Today Transient response objectives Step response of unity feedback system Measures of response Relate step response objective to Gain crossover Phase margin Frequency domain performance Limitations Reading FPE 6.5, 6.6, 6.7.7. 6.7.8 Nov. 10, 2011 Feedback Control Systems (I) Douglas Looze 6 Transient (Step) Response Unity feedback system- r u y m y e ( 29 D s d ( 29 G s Loop transfer function Frequency response ( 29 ( 29 ( 29 L s G s D s = (29 (29 (29 (29 (29 (29 1 Ls y s r s T s r s Ls = = + ( 29 ( 29 T s r s = Nov. 10, 2011 Feedback Control Systems (I) Douglas Looze 7 Objective ( 29 ( 29 ( 29 y t r t t = Can we do this? ( 29 ( 29 ( 29 ( 29 1 1 1 y t t T s s s T s This requires ( 29 ( 29 ( 29 1 1 L s T s L s = + ( 29 ( 29 1 L s L s + Approximate ( 29 1 L s ? Integral control But ( 29 L s ( 29 ( 29 ( 29 ( 29 1 1 1 y t t T s s s T s ( 29 ( 29 ( 29 ( 29 1 1 1 y t t T s s s T s Nov. 10, 2011 Feedback Control Systems (I) Douglas Looze 8 Typical Step Response 1 2 3 4 5 6 7 8 9 10 0.2 0.4 0.6 0.8 1 1.2 1.4 Step Response T ime (sec) Amplitude 0.1 ss y ss y 0.9 ss y d t } r t p t p M ss y } s t Dead Time Rise Time (10-90%) Peak Time Peak Overshoot Settling Time ( 29 ( 29 Measure how , , , , , d r p s ss p y t t t t t t y M 1 4 442 4 4 43 Nov. 10, 2011 Feedback Control Systems (I) Douglas Looze 9 Two-Dominant Pole Model Assume ( 29 2 2 2 2 n n n T s s s = + + Reasonable? Nov. 10, 2011 Feedback Control Systems (I) Douglas Looze 10- 1 Reasonable Must be stable Nyquist locus Re L Im L M 90 M < < 2 more poles than zeros 1 pole before gain crossover 1 pole after gain crossover Gain crossover Nov. 10, 2011 Feedback Control Systems (I) Douglas Looze 11 Two-Dominant Pole Model Assume ( 29 2 2 2 2 n n n T s s s = + + No zeros 2 poles 2 2 2 1 , 2 2 1 n n n...
View Full Document

This document was uploaded on 02/22/2012.

Page1 / 34

ece580 lecture 18 - Nov. 10, 2011 Feedback Control Systems...

This preview shows document pages 1 - 12. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online