Specifications

10 Design Case Studies
10-46
lsim(Pc(1:2,3:6),':',cl(1:2,3:6),'-',wxy,t)
The response reveals a severe deterioration in regulation performance along
the -axis (the peak thickness variation is about four times larger than in the
simulation without cross-coupling). Hence, designing for one loop at a time is
inadequate for this level of cross-coupling, and you must perform a joint-axis
MIMO design to correctly handle coupling effects.
MIMO LQG Design
Start with the complete two-axis state-space model Pc derived above. The
model inputs and outputs are
Pc.inputname
ans =
'u-x'
'u-y'
'w-ex'
'w-ix'
x