Helicopter control case study

Dear David

Thank you for your message.

Here are answers to some of your questions:

1.There are no reference demands on the rates which are fed back to the controller to
improve performance -- rate feedback good! Note the position of p and q in the output
vector. I think this is clearer in the book than the paper.

2. Different linearizations, I think.

3. I am afraid I don't have the time to check the code.

Hope this is of some help

Regards

Ian
************************************************
>From: O'CONNOR DAVID PATRICK <9514236@student.ul.ie>
>To: "'ixp@le.ac.uk'" <ixp@leicester.ac.uk>
>Subject: Date: Mon, 15 Feb 1999 16:02:02 -0000
>
>Dear Sir,
>I am a Final year student at the University of Limerick, Ireland,
>finishing a degree in Computer Engineering. As part of this degree I am
>doing a project on Helicopter Control. I am studying your 1990 paper
>entitled "Improvement of helicopter handling qualities using H-inf
>optimisation" and the example in chapter 12 of your book, "Mulitvariable
>Feedback control and analysis", as an introduction to the project. I
>have been able to reproduce most of the results that you obtained, a
>halving effect in the disturbances using the explicit disturbance
>rejection design, and the Singular Value plots, i.e Figures 12.3/12.5
>(a) and (b) using sysic and simulink. I was wondering if you wouldn't
>mind answering one or two questions that I have :
>
>1) In the 1990 paper you have as input vector v = [ coll 0 0 pedal
>long latt]. What are the two zeros for, do they represent any specific
>inputs, and why are they in those specific locations in the input
>matrix?
>
>2) In the 1990 paper the max. singular value of inv(I+GK)
>seem to be smaller than that of those in the book, chapter 12. Is there
>any particular reasoning behind this?
>
>3) The code on the Webpage for Sec12_2.m dosn't seem to
>work for the disturbance rejection design. The code stops at matrix B1
>for this design. I have what I believe to be a solution.
>B1=[zeros(n,p) Bg;
> bw1*dw3 zeros(bg1,bg2);
> zeros(n2,p) zeros(n2,bg2)];
>I am running Matlab version 5.2.1.1420. Is this code change correct in
>your opinion?
>
>Thank you for your time and consideration in reading this mail.
>Regards,
> David O'Connor
>

*******************************
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 Thu Feb 25 17:19:15 1999