MathGroup Archive 2005

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: ControlSystems Wolfram application. Does it support root locus for discrete time systems?

  • To: mathgroup at smc.vnet.net
  • Subject: [mg60015] Re: ControlSystems Wolfram application. Does it support root locus for discrete time systems?
  • From: "Nasser Abbasi" <nma at 12000.org>
  • Date: Sun, 28 Aug 2005 03:07:56 -0400 (EDT)
  • References: <dek88k$aag$1@smc.vnet.net>
  • Sender: owner-wri-mathgroup at wolfram.com

 

"Nasser Abbasi" <nma at 12000.org> wrote in message 
news:dek88k$aag$1 at smc.vnet.net...
>
>
>
>
> Any ControlSystems package users out there?
>
> I can't seem to figure how to generate, using the ControlSystems
> package, the root locus for a sampled system. It works OK for
> continues-time system as you can here:
>
> http://12000.org/my_notes/mma_matlab_control/e45/HTML/e45.htm
>
> But when I try to sample the system, it gives the wrong root locus:
>
> http://12000.org/my_notes/mma_matlab_control/e68/HTML/e68.htm
>
> thanks,
> Nasser

The problem is resolved now.

I needed to use the correct plot range to 'see' the root locus. It was 
there all along, but was too small to see.
(If there was a good zoom option, I would probably have found this 
earlier).

I did not notice this, since in that 'other' system, the plot range 
for the root locus is determined automatically, for example, for a 
discrete system, one is mostly interested in what the root locus looks 
like inside and close to the unit circle.

Any way, Mathematica can for sure generate the correct root locus for 
a sampled time system, but one needs to be careful how to use the 
command.

The updated plot is found here:

http://www.12000.org/my_notes/mma_matlab_control/e68/HTML/e68.htm

Nasser 



  • Prev by Date: Re: help working with functions
  • Next by Date: Re: How to solve this type of equation in Mathematica?
  • Previous by thread: ControlSystems Wolfram application. Does it support root locus for discrete time systems?
  • Next by thread: inconsistency with Inequality testing and Floor