Re: chapter 8 in discrete time?

Dear Sigurd

I think you are both OK

Ghassan Murad's thesis, which you examined and I think you may have a copy, has a lot of
useful discrete time formula if Josh prefers to stay in discrete-time.

I have spare copies and can send Josh a copy if he wants one.

I don't have his address

Regards

Ian

**************************************************************

>
>Dear Josh,
>
>I would have made a continous-time version and proceeded, but
>what you suggest may be OK (I will ask my coauthor).
>
>Both of these methods will only be an approximation, though.
>(but most likely OK!)
>
>To handle the discrete case exactly you would need to use the state-space
>mu test descibed on page 345 in the book.
>
>Good luck.
>
>-Sigurd Skogestad
>
>
>>>From kanterjm@seas.upenn.edu Mon Dec 21 23:55:39 1998
>>Delivered-To: skoge@ona.chembio.ntnu.no
>>
>>Hi again!
>>
>>I was wondering if you had any advice on the following:
>>
>>I have a discrete time MIMO system,H(z) and I'd like to check the robust
>>stability and robust performance conditions in chapter 8. How do I do
>>this? Do I just replace s=iw with z=exp(Tiw), replace lhp with inside
>>the unit circle, and replace for all w with 0<=w<=pi/T?
>>
>>I've been looking all over the book and all your references, but I
>>haven't found anmything about testing robust stability and robust
>>performance for discrete time MIMO systems. ANY ADVICE WOULD BE GREATLY
>>APPRECIATED!!!
>>
>>Thanks for your time and happy holidays
>>
>>Josh
>
>

*******************************
Professor Ian Postlethwaite
Head of Department
Department of Engineering
University of Leicester
Leicester LE1 7RH
UK

Tel: +44 (0)116 252 2547
Fax: +44 (0)116 252 2619
Email: ixp@le.ac.uk
Received on Tue Dec 22 09:43:51 1998