On Fri, 27 Jan 2012, Viesturs L?cis wrote: > Date: Fri, 27 Jan 2012 22:22:33 +0200 > From: "[UTF-8] Viesturs L?cis" <viesturs.la...@gmail.com> > 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] Servo tuning - wtf? > > 2012/1/27 andy pugh <bodge...@gmail.com>: >> On 27 January 2012 19:54, Peter C. Wallace <p...@mesanet.com> wrote: >> >>> What BLDC mode are you using? >> ... >>> If not you may somehow have lost encoder counts, this should be checked >> >> Try mode "h" and comment-out the rawcounts lines, that ought to make >> it stick in Hal-sensor mode, and then it can't lose synch. >> > > Hmm, I used "h" mode, when I tried to set up bldc component to move > motors properly. How is that going to help me? > Motors move smoothly up to ~1500RPM, but my ideal target is 4000RPM. > minimum target is 3000RPM, so I would like to find out, if there is a > place to read about the strategy, how to tune servos from this point. > I tried increasing/decreasing P and D parameters, but do not see > improvement. > > Viesturs
This is not likely a tuning problem... More likely that you have either run out of headroom (what is the motor voltage vs supply voltage?) or you have a commutation problem. Commutation problems will happen if you have encoder count errors in q, qi, or qh mode Of course if you have encoder count problems these need to be fixed whatever commutation mode you use, but using h mode will eliminate encoder count problems as a suspect in you oscillation troubles. Another detail that can cause strange behavior if you are close to the maximum RPM because of voltage limits, is the maximum PWM duty cycle. This should be limited via the PID components max_output parameter to about 95% of the PWM components full scale value. > > ------------------------------------------------------------------------------ > Try before you buy = See our experts in action! > The most comprehensive online learning library for Microsoft developers > is just $99.99! Visual Studio, SharePoint, SQL - plus HTML5, CSS3, MVC3, > Metro Style Apps, more. Free future releases when you subscribe now! > http://p.sf.net/sfu/learndevnow-dev2 > _______________________________________________ > 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. ------------------------------------------------------------------------------ Try before you buy = See our experts in action! The most comprehensive online learning library for Microsoft developers is just $99.99! Visual Studio, SharePoint, SQL - plus HTML5, CSS3, MVC3, Metro Style Apps, more. Free future releases when you subscribe now! http://p.sf.net/sfu/learndevnow-dev2 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
