車(chē)輛工程-大三自動(dòng)控制原理課件typical elements

5-3PlotofOpen-loopFrequencyInthisTypicalFrequencycharacteristicsoftypicalelementsOpen-loopamplitude-phaseplotOpen-looplogarithmicfrequencycharacteristicsDelayelementsanddelaysystemsExperimentaldeterminationofFC CH5Frequency 1.TypicalMinimum Non-minimum比例環(huán)

1/(-Ts+1) CH5Frequency 1.TypicalMinimum Non-minimumn1n00n1n00n1s s振蕩環(huán)

2s

s2 2sn1n1nn1n1n11

s2

2s

s 20n0n01

2snn00nn001

CH5Frequency TypicalOLTFtypical

G(s)H(s) Gi(s)i)) Frequencycharacteristics：Gi( Ai )e )) OLamplitude-frequency A

))Ai)) ()) ())iOL )) ))L 20lgA(

20lgAi

Li CH5Frequency （1）Proportional 0)j0KNyquist

)20lg0 Bode CH5Frequency Integral G(s) s [ (rad/ 1

j

(rad/0 Nyquist

Bode CH5Frequency Differential

G(s) 0

j-00

1

j(rad/ Nyquist

0Bode CH5Frequency 1Inertial 1Ts

T 0)1)11jjT1TG(j1000Nyquist

1( CH5Frequency Bode

1對(duì)數(shù)頻率特性曲 1T1G( T1j

[

(rad/ T T

0T

(rad/L( 20 2T

0T-20T

1 Lowfrequency1 Highfrequency

CrossoverT CH5Frequency T（5）1stDifferential

G(s) 1, 0 )j1 10

1

(rad/

TNyquist

450 TBode

(rad/ CH5Frequency G6）Oscillating (

n00 s2 2s n00 G(

nn j2nn n2n2 2 2 j 1njXdhence 1njXd2G( 2 dn CH5Frequency NyquistPlot(幅相曲線

G(j0 G( u幅相曲 CH5Frequency 2j2Frequency 2j2G(

242nn242nn22

2n22n2 CH5Frequency

drn122 2rn122rrPeak M

2

2nDimensionless 2nrn122Dimensionlessrn122frequency無(wú)因次諧振頻 CH5Frequency Frequency j2n)G( j2n)12nBode2n22n0-2n0-nnn40nnn22 22n22n

2n2nLowfrequencyasymptoteHighfrequencyasymptoteCrossover CH5Frequency 22nL( 20lg ) 22n

22nnn

nnn[ (rad/n[0-n400-n

2n22n 2n22n1

n1n

(rad/ CH5Frequency Bode CH5Frequency 00n12n2s1n（7）2nd00n12n2s1n[[n1 n1 n9n

(rad/0 0

(rad/ CH5Frequency （8）Non-minimumphaseNoteonNyquistplotissymmetricwithrealaxis(except（比例環(huán)節(jié)例外Samelogarithmicam-freLogarithmicpha-freissymmetricwith對(duì)數(shù)相頻曲線關(guān)于0°線對(duì)稱(chēng)（比例環(huán)節(jié)例外 CH5Frequency （a）

0) )j20lg0 Nyquist

Bode CH5Frequency 11 )（b11 )j )

T 0)

(rad/T1

[[1 101(

00

(rad/1( Nyquist Bode CH5Frequency Tj12、典型環(huán)節(jié)的 Tj1非最小相位一階微分環(huán)節(jié) j

T), 0 )j

(rad/T T j1 1450

1 T111 1

(rad/11

Bode CH5Frequency j

n00n1ns2 2sn00n1n 0n n (rad/ [[n n

(r