19.07.2014 Views

[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

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

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.

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!