1
PID
Tuning of PID Controllers Based on Gain and Phase Margin Specifications Using Fuzzy Neural Network NSC87-2218-E009-026 86/08/01- 87/7/31 ( !":PID #$%&'() *#+,-.#/0-.) 12345+,-./0-.678 9:;<=$%&'()*>?@AB6CD
PID E6FGHIFGJ=KCD PID
E6LM;NOPQ+,-./0-.7 869:HR5ST+,-.U/0-.6V WXYQ6MFZ[\];X^_`ab cd@edf6ghiFGJ^jkl mndo6PQ789:HX^;p12q; rs;<=$%&'($tKuv78U PID ELMwx6 yHbz;<=$%&' ()*{|CD PID E6LM^}~ 6+,-./0-.678HIN =]6M 6FKiH I;UO6FG;$YX >?K6FGJ^kl6PQ9:mnd oH
(Keywords: PID Control, Fuzzy neural network, Gain margin, Phase margin)
In this project, we will give an effective PID tuning method using fuzzy neural network based on gain and phase margin specifications (FNGP). We will use the fuzzy neural networks to determine the parameters of PID controllers. Because of the analytical design method to achieve the specified gain and phase margins is not available to date.
In this study, we will use a fuzzy neural modeling method to identify the relationship for different gain and phase margin specifications. So that neither numerical methods nor graphical methods have to be used. This will make it easy and effective to tune the controller parameters to have the specified robustness and performance.
K;? ¡ PID EL MwCDFG;9¢£¤¥(¦§ ¨H©ªCoon Cohen >?@«ST¬* w®¯°±²³KCDLM6FG[1]´µ¶ J<=·¸¹º(Nyquist curve)K»¼L MH½¾ª¿;ÀÁFGÂN=fwÃgÄ Å;ƽG>ÇÈÉ6CDGÊËoHÌ K;ÍÈt Ziegler-Nichols G[2]ÎÏÐxÑ Ò6/0-.(Phase margin)G[3]ÓÔ>?;Õ ËÖ×½GÍØH +,-.(Gain margin)/0-.@A= KÙVfÚÛÜ6Ý9GÊHmi EKÞß+,-./0-.(GPM)78Æ @ABFG;pàáâN=KC DELM;À@AãÐãä6FG;Æ ½G=på±LM{|CDGÊH æ Ì ç è é ê 6 $ % & '( ) * (Fuzzy neural network);ëìw;í@«'()*; ÕD«'()*6îïª@«$% f;Iàáðwñ$%&'()*Hò d'()*6óôõöJ÷#Jøù## ú´Óûd$%E6üôýöþ5# þ5i#d6å±(Adaptive)#Û
(Robustness)Æd6(Fault tolerance)
úHI±=p PID E6LMCD j{b6H p1 2;àá<=$%&'()* >?@ë do6 PID LMCDGÊH IFG345+,-./0-.678 (specification)9:;±=$%&'()*KCD PIDELMHàá<=À«FGK :]6Gw;ÆÍ Ø6;^PQÈÉ6ËoH
2 +,-./0-.Gñ C. C. Hang ú [4]p 1995 >?;O±=@ÁÌMKë ;^:Yϱ6LMHR5 C. C. Hang ú [4]w$ËYO;JX>?w FGÆ@«do#J6FG;Iàá >?@«do6FG;IFG<=$ %&'()*K{|CD PID LM;^PQ àá678H rs@fEw y; 1. @«D6 *fHOVWf E6 !" M (Transfer function) g# ñ ) (s GP UGC(s);m+,-./0-.678ñ m m A ,φ H^$Ê+,-./0-.6VW , )] ( ) ( arg[Gc jwp Gp jwp =−π (1) ) ( ) ( 1 p p p c m jw G jw G A = (2) ) ( ) ( g p g c jw G jw G =1 (3) π φm=arg[Gc(jwg)Gp(jwg)]+ (4) wp (phase crossover
frequency) wg (gain crossover frequency) PI ) 1 1 ( ) ( I c c sT K s G = + KCTI Ls dp dp d d d d nq nq n n n n p p e s w s w s w s w s w s w K s G − + + + + + + = ) 1 ( ) 1 ( ) 1 ( ) 1 ( ) 1 ( ) 1 ( ) ( 2 2 1 1 2 2 1 1 L L . wni, wdi L !" #$(zero)% $(pole)&'() *+,-./0 1(loop transfer function)
Ls dp dp d d d d I nq nq n n n n I p c p c sT w s w s ws e s w s w s w sT K K s G s G − + + + + + + + = ) 1 ( ) 1 ( ) 1 ( ) 1 ( ) 1 ( ) 1 )( 1 ( ) ( ) ( 2 2 1 1 2 2 1 1 L L . 2345678(1-4) L w w w n w w n T wp I + p n + + q p nq − p
+tan−( ) tan−( ) tan−( ) 2 1 1 1 1 1 1 L π 0 ) ( tan ) ( tan ) ( tan 1 2 1 2 1 1 1 − − − = − − − − dp p p d p d pw d ww d w w w d L ,(5) dp dp p d d p d d p nq nq p n n p I p I p p c m w w w w w w w w w w T w T w K K A ) 1 ( ) 1 ( ) 1 ( ) 1 ( ) 1 ( 1 2 2 2 2 2 2 1 2 1 2 2 2 1 2 1 2 2 2 + + + + + + = L L , (6) nq nq g n n g I g dp dp g d d g d d g I g p c w w w w T w w w w w w w T w K K ) 1 ( ) 1 ( ) 1 ( ) 1 ( ) 1 ( ) 1 ( 2 2 1 2 1 2 2 2 2 2 2 2 2 2 1 2 1 2 + + + − + + = L L , (7) L w w w n w w n T wg I g n q g nq g m= + + + + − − − − ) ( tan ) ( tan ) ( tan 2 1 1 1 1 1 1 L π φ ) ( tan ) ( tan ) ( tan 1 2 1 2 1 1 1 wgwd d wgwd dp wgwdp d − − − − − − − L . (8) (Am,φm)(5)-(8) !"#$%&'() PI *+,-.# (KC,TI)/0123(wp,wg)456789 :;<=#(arctan function)>?&@ABC &D&E 5FGHI&JK(coupled):;<= #@LMNI'AOP(5)-(8)&Q RSTUVW"XYZ[\]^_() `a=#(5)-(8)bc 2dc 2 5efghE ic 2 7>W"XYZ[\]^5B Cjk]^lmnbc 3E[\]^oBk p Linguistic term layerqrsXYtEV W"uv=#5wx=#(bell function)Eoy kTzXY%{|}~BC node zEokp;tVoykr ;tEok!"%zE ojk{p&XYtW%z' r E iV!"OP %(linear least-squares method)AO (off-line learning)'[\]^7-.#$Ei ? FNN 5 g B r 5 output=F(I,S),l7 I 5rsS 5.#E .# S ¡¢£¤¥¦iB=# H §'¨©=# HoF 5BOP=#{ !" %_ª«?.#E¬fAO %® ¯°B®' M ±²³´XP=Yl
3 7 [ ,...., ] , [ ,...., , ,..., ,..., 1,..., ] 1 1 1 0 1 0 2 1 n k k n n T P p p p p p p y y Y = = E ¯°y®!"%_µ¶.# P Y X X X P*=( T )−1 T E ¯°®§"¬·¸6% z . #$ M i i T i i T i i i i i i i i i i i i P P M i x Q x Q x x Q Q Q P x y x Q P P = − = + − = ⋅ − + = + + + + + + + + + + 1 ,...., 1 , 0 , 1 ) ( 1 1 1 1 1 1 1 1 1 1 l7¹º$»5 P0=0,Q0=α⋅I (α 5B¼; #)E(½¾z .¿ÀÁ[5]) NÂW"Ã~%(Gradient Method) O (on-line learning) § Ä Å = # 2 2 1[ ] I P I y y E = − tl7 y pi2Æ-P r y pXYZ[\]^ FNGP r (ÇcI 2.)EÃ~% fb¬®ÈÉI'Ä Å=#-Ã~(gradient) . ) ( ) ( ) ( ) ( ) ( ) ( 1 1 1 1 S k O k e S k y k e S k e k e S E I I I I I I I ∂ ∂ ∂ ∂ ∂ ∂ ∂ ∂ − = − = = FNN7 Ê.#Ë "¬%{_ÊÌ ( 1) ( ) ( ) ( ) ( ) S E k S k S k S k S I I ∂ ∂ η − + = ∆ + = + l7ηI 53(Learning rate). pÍ PI *+,.#-ÊÎ PID *+,ÊÎ.#% PI *+,Ͻ¾Ð ÑÒÓ ÔÕÐÖ×.Ø.¿ÀÁ[4]E i?!">Ù % C. C. Hang ÚÓ>-XÛÜÝÞBßeB à C. C. Hang ÚÓ>Ù-ÄÅ$á¼â% ãäå"iæçè éê-%{¼¼ë ì?Bí §-LîïEXÛ7ðñ =#® ) 1 ( ) ( 0.1 s e s Gp s + = − E c 4 c 5 òó5ôÏ - X Û Ü Ý d ¯ õ ö å h l 5 ) 45 , 3 ( ) , ( 0 = m m A φ ( , 0)=(5,60) m m A φ E QRSTU÷!"XYZ[\_ª« ø PID *+,.#-ùúE@!"XYZ[\]^ÔûÊÎ PID *+,.#üKôÏ E4?ôýþ§"a#$z ×pUc6_T*+,E?V l%Þße L9 þIì ' PID *+,. #E?TU §æçè PID *+,§" Lô.#ÊÎE4 5!"?RSTU©ÝVô\ ÊÎ ' PID *+,.#E
[1] G. H. Cohen and G. A. Coon, “Theoretical Consideration of Retarded Control,” Trans. ASME, Vol. 75, pp. 827-834, 1953.
[2] C. C. Hang, K. J. Astrom, and W. K. Ho, “Reinements of the Ziegler-Nichols Tuning Formula,” IEE Proc. D, Vol. 138, No. 2, pp.111-118, 1991.
[3] K. J. Astrom, “Automatic Tuning of Simple Regulator with Specification on Phase and Amplitude Margins,” Automatica, Vol. 20, No. 5, pp.645-651, 1984.
[4] W. K. Ho, C. C. Hang, and L. S. Cao, “Tuning of PID Controller Based on Gain and Phase Margin Specification,” Automatica, Vol. 31, No. 3, pp. 497-502, 1995.
[5] T. C. Hsia, System Identification : Least-Squares Methods (New York, Heath, 1977).
4 r e u yp open loop
G s
c( )
G s
p( )
+ -. 1 1 2 0 1 1 1 1 1 2 2 2 2 2 2 2 2 2 π τ τ τ φ π τ + − − = = ++ = + + = + − − arctan ( ) arctan ( ) , , , arctan ( ) arctan ( ) . w T w w L A K K w T w Tw K K w T w w T w T w w L p I p p m c p p I p p I c p g I g g I m g I g g FNGP ( , )K Tc I yp yI e + -( , )Amφm ( $ , $ )K Tc I 2. lay er 1layer 2 layer 3 layer 4 layer 5
Am φm A1 An Ai n+ A2n ∏ ∏ N N ∑ w1 wn2 wn2 w1 w f1 1 w fn2 n2 yI Am φm Am φm R R µA1 µAn µAi n+ µA2n 3. Step response Magni tu de ___ uncom pensated - - - GPM - . - FNGP e s s − + 01 1 . ( ,3 45o) Process Spec. Tim e ( sec) 4. 3dB,45o Step response M agn it ud e Time (sec) e s s − + 01 1 . ( ,5 60o) Process Spec. ___ uncompensated - - - GPM - . - FNGP 5. 5dB,60o m A o m φ Kc TI wg wp A*m * m φ Am′ φ ′m GPM 3 45 4.908 0.352 5.398 12.78 3.307 40.30 10.2% 10.4% 5 60 3.054 0.541 3.341 13.53 5.990 58.14 19.8% 3.10% FNGP 3 45 6.198 0.562 6.243 13.58 2.978 45.41 0.71% 0.91% 5 60 3.785 0.660 3.921 13.77 5.029 60.03 0.58% 0.07% 1.