question about robustness of LQR controllers

Dear,

I'm working as a research engineer at LMS in Leuven, Belgium (a sofware and
engineering company with a focus on noise, vibrations, durability and
mechanical simulation for the automotive industry) and I'm currently reading
your book 'Multivariable Feedback Control. Analysis and Design' which is of
great interest to my work.

In this context, I have a question about section 9.2.2. where it is
mentioned that LQR controllers exhibit certain (excellent) robustness
properties. My question is if this is also true for a discrete controller
design (so starting from a discrete-time state space model and using for
example 'dlqr' in Matlab) ? It seems to me that this is NOT the case. Can
you provide me with some more information on this ?

Thanks in advance,

Joris De Cuyper

++++++++++++++++++++++++++++++++++++++++++++++++
Joris De Cuyper
Research Engineer
LMS International
Interleuvenlaan 68
B - 3001 Leuven
tel. +32 16 384 233
fax. +32 16 384 350
Received on Fri Apr 21 18:03:56 2000