[Luyben] Process Mod.. - Student subdomain for University of Bath
[Luyben] Process Mod.. - Student subdomain for University of Bath
[Luyben] Process Mod.. - Student subdomain for University of Bath
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570 MULTIVARIABLE PROCESSES<br />
TABLE 16.2 (continued)<br />
C<br />
SUBROUTINE PROCTF(GM,W,N,KP,TAU,D)<br />
DIMENSION KP(4,4),TAU(4,4,4),D(4,4)<br />
COMPLEX GM(4,4),ZL,ZD<br />
REAL KP<br />
ZL(X)=CMPLX(l.,X*W)<br />
ZD(X)=CMPLX(COS(W*X),-SIN(W*X))<br />
DO 10 I=l,N<br />
DO 10 J=l,N<br />
10 GM(I,J)=KP(I,J)*ZD(D(I,J))*ZL(TAU(l,I,J))/ZL(TAU(2,I,J))<br />
+ /ZL(TAU(3,I,J))/ZL(TAU(4,I,J))<br />
RETURN<br />
END<br />
Results<br />
W WQl) WQl) RE(Q2) IWQ2)<br />
.OlOOO -10.93861 -73.93397 -.69893 -10.97331<br />
.01259 -10.77362 -57.94015 -.70154 -8.69403<br />
.01585 -10.52296 -45.07131 -.70426 -6.87520<br />
.01995 -10.15061 -34.67506 -.70560 -5.41860<br />
.02512 -9.61544 -26.25261 -.70209 -4.24563<br />
.03162 -8.88105 -19.43858 -.68745 -3.29489<br />
.03981 -7.93375 -13.98019 -.65334 -2.52193<br />
.05012 -6.80296 -9.70591 -.59328 -1.89904<br />
.06310 -5.56933 -6.48106 -.50896 -1.41125<br />
.07943 -4.34690 -4.16391 -.41292 -1.04679<br />
.10000 -3.24441 -2.58527 -.32303 -.78823<br />
.12589 -2.33036 -1.56020 -.25321 -.61188<br />
.15849 -1.62209 -.91593 -.20913 -.49410<br />
.19953 -1.09771 -.51329 -.19052 -.41728<br />
.25119 -.71786 -.25031 -.19364 -.37372<br />
.31623 -.19787 -.35982 -.45773 -.06077<br />
.39811 -.19106 -.33411 -.29072 .05551<br />
.50119 -.19649 -.28201 -.16390 .10739<br />
.63096 -.20761 -.20640 -.06256 .10977<br />
.79433 -.19927 -.11268 .00200 .07250<br />
1 .ooooo -.14416 -.03580 .00868 .03019<br />
1.25893 -.10863 -.03576 .02118 .04213<br />
1.58489 -.10893 .01474 .04596 -.01127<br />
1.99526 -.05624 .03026 -.00732 -.01991<br />
2.51189<br />
.06183 -.02432 -.01433<br />
Note that these eigenvalues are neither the openloop eigenvalues nor the closedloop<br />
eigenvalues <strong>of</strong> the system! They are eigenvalues <strong>of</strong> a completely different<br />
matrix, not the 4 or the 4cL matrices.<br />
Characteristic loci plots <strong>for</strong> the Wood and Berry column are shown in Fig.<br />
16.3. They show that the empirical controllers settings give a stable closedloop<br />
system, but the ZN settings do not since the q1 eigenvalue goes through the<br />
(- JO) point.<br />
A brief justification <strong>for</strong> the characteristic loci method (thanks to C. C. Yu) is<br />
sketched below. For a more rigorous treatment see McFarland and Belletrutti<br />
(Automatica 1973, Vol. 8, p. 455). We assume an openloop stable system so the<br />
closedloop characteristic equation has no poles in the right half <strong>of</strong> the s plane.