Re: From Ouiserg,Kim

Dear Ouisberg

The scaling Wi below should ensure that the steady state error is
zero to steps.

After reducing the controller you will need to recalculate Wi with
the new K1 and K2. Assuming the controller still stabilises the
system the steady state error to steps will again be zero.

Regards

IP

> > From oskim@amed.snu.ac.kr Wed May 17 08:11:49 2000
> > org:Institute of Advanced Machinery and Design, Seoul National Univ.;Advanced
> Machine Elem ents Design Lab.
> > Subject: [Q]Steady state gain matching with controller reduction
> >
> >Dear Skogestad and Postlethwaite,
> >
> >I have adopted a 2dof Hinf control to my system successfully and it
> >shows good tracking performance.
> >The controller has a little bit high state order so that I reduced the
> >states of the controller using optimal Hankel norm approximation. In
> >that case, reduced controller can't follow the reference command in
> >SIMULINK simulation. I guess that there needs some modification for
> >steady state gain matching.
> >The scaling constant matrix Wi given by (remark3 :eq(9.89), pp.388)
> >doesn't match.
> >How can I modify the scaling matrix Wi ?
> >
> >Best Regards,
> >
> >Ouiserg,Kim
>
>
-------------------------------------------
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)116 223 1369
Email: ixp@le.ac.uk
Received on Thu May 18 09:54:20 2000