On Fri, 10 Jul 2009, Leslie Newell wrote: > Date: Fri, 10 Jul 2009 22:34:37 +0100 > From: Leslie Newell <les.new...@fastmail.co.uk> > Reply-To: "Enhanced Machine Controller (EMC)" > <emc-users@lists.sourceforge.net> > To: "Enhanced Machine Controller (EMC)" <emc-users@lists.sourceforge.net> > Subject: Re: [Emc-users] Hostmot2 homing > > Hi Peter, > > I can't see any way of achiving a trip in 20ms. I have the PID > saturation limit hooked to my estop chain but it only trips once the amp > reaches full output (BTW, the hostmot2 example config does not implement > this). If the I term doesn't build up quickly to saturate the output > then the axis can travel a long way.
With a small error (1 count or so) thats possible but that also most likely indicates that your integral term is way too low. > > I just ran some tests and I could easily get my X axis to travel from > near one limit to the other limit by disconnecting the encoder, just > driven by I term. Good job I've got good limits :-) > > Interestingly, reducing the I term limit actually makes things worse. > The I term limit doesn't trip an error but it does limit the output. > Therefore you can end up with the output near maximum but not enough to > trip an error. Thats probably something that should be fixed in the PID component (indicate saturate also when integral term is in limit) > > Les > >> >> No, PID saturate can get that in 20 mS or less... > > > ------------------------------------------------------------------------------ > Enter the BlackBerry Developer Challenge > This is your chance to win up to $100,000 in prizes! For a limited time, > vendors submitting new applications to BlackBerry App World(TM) will have > the opportunity to enter the BlackBerry Developer Challenge. See full prize > details at: http://p.sf.net/sfu/Challenge > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > Peter Wallace Mesa Electronics (\__/) (='.'=) This is Bunny. Copy and paste bunny into your (")_(") signature to help him gain world domination. ------------------------------------------------------------------------------ Enter the BlackBerry Developer Challenge This is your chance to win up to $100,000 in prizes! For a limited time, vendors submitting new applications to BlackBerry App World(TM) will have the opportunity to enter the BlackBerry Developer Challenge. See full prize details at: http://p.sf.net/sfu/Challenge _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
