Lecture7

# Cannot achieve regulation if gs is large open loop

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Unformatted text preview: m is to keep the error small when the reference is at a present. Regulation: E = (1 − GD)R − GW most constant set point and disturbances are ⇒ The controller D(s) has no inﬂuence on how the disturbance w affects the error e(t). ⇒ Cannot achieve regulation if G(s) is “large”. Open-loop control is no good unless G(s) is stable and w(t) is small. 3 5 Feedback Control Y= GD G −GD R+ W+ V 1 + GD 1 + GD 1 + GD Denominator of closed-loop transfer function is common: 1 + GD. Numerators are as follows, R W V Y GD G −GD E 1 −G GD U D −GD −D Stability: G(s) = a(s) , b (s ) D ( s) = c (s ) d (s ) GD a (s )c (s ) = 1 + GD a(s)c(s) + b(s)d(s) Characteristic equation: a(s)c(s) + b(s)d(s) = 0. Poles: a...
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## This note was uploaded on 01/27/2014 for the course MAE 171A taught by Professor Idan during the Winter '09 term at UCLA.

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