🚀 go-pugleaf

   I have a question for those of you readers who have performed
optimal controller synthesis using the robust control and mutools
toolboxes available in matlab.  I am attempting to design a controller
for an "improper" system, i.e., the frequency response does not
roll-off at high frequencies.  Is there any such requirement on the
plant in order to use the 'hinfsyn', 'h2syn', musynfit, etc.
functions.

   The problem I am encountering does not seem to be related to this; I
have problems with the row rank test on the matrix, [a b1; c2, d21].
This matrix ends up being (7x5) and thus cannot have full row rank.
Obviously, I have formulated the problem incorrectly, but I am not sure
where I've gone astray.  There are three measurements available to the
controller and the "Z" vector (the measurements to be kept small) has
one measurement.  The performance specification (Wp) is second order,
is this okay??  Can anyone give me possible avenues to explore which I
might have missed??  The requirement indicates that the number (n+p)
must be equal to or less than (n+m1+m2), where;

	n  = number of states,
	p  = number of outputs,
	m1 = number of exogenous inputs,
	m2 = number of controls


   Any ideas would be greatly appreciated either by e-mail or via
posting.  Thanks in advance.

					Befuddled but not Defeated,

					-BJS-


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Brian J. Scallan,				  scallan@sweetpea.jsc.nasa.gov

When angry, count four; when very angry, swear.
Pudd'nhead Wilson - M. Twain

The opinions expressed 
should not be interpreted as those 
of my employer or any other (semi-)rational entity.			{-BJS-}
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