Re: [Linuxptp-devel] Optimal P, I constants

[Richard C. <ric...@gm...>]

On Fri, May 10, 2013 at 05:00:17PM +0200, Miroslav Lichvar wrote:
> On Fri, May 10, 2013 at 04:23:21PM +0200, Richard Cochran wrote:
> > 
> > According to the analysis in the Eidson book, the constants marked
> > with * are not stable, and my simplistic servo simulator also confirms
> > this.
> 
> Can you please share the code and settings that show the instability?
> I see no problems with:
> 
> pi_sim -s 0.25 -p 2.5 -i 1.5
> pi_sim -s 0.125 -p 5.0 -i 1.5
> pi_sim -s 0.0625 -p 6.1 -i 1.2

Yes, you are right, I neglected the -s setting.

I am beginning to think that there is an error in Eidson's analysis,
because I noticed another unexpected detail regarding the estimated
settling time.

For now, we can leave off any limits on the user PI constants. My
focus now is to generate a set of reasonable defaults.

Thanks,
Richard