Proportional, Integral, Differential... those are the words behind PID regulator... so, observe: it is a REGULATOR, so it does some transfer functions, which are named above. Tuning PID regulator is a science, but when done right it does the job properly. I would look into the Integration part of the regulator... well, at least in the analog PID counterpart. And... if the encoder is sensed by measuring time between intervals, it provides more speed resolution at lower speeds. (I do not think the endoder sensing can be done by any other way on a PC.)
On 12/28/06, Anders Wallin <[EMAIL PROTECTED]> wrote: > > Hi all, > > With a servo system using quadrature encoder feedback, what is the > slowest speed that can reliably be used ? > > I would imagine that there is a problem if there are no counts between > successive calls to the PID loop ? resulting in jerky instead of smooth > slow motion ? > > any way to improve on this using some smart HAL code ? > > The setup I'm planning would use a 1000 line encoder (4000counts/rev) > motor directly coupled to a 2.5mm/rev ballscrew. If I require one count > for each call to the PID loop (1 kHz count rate) then that works out to > 0.25rev/s or 15 rpm or a feedrate of 37.5mm/min which does not seem that > low ?? > > comments appreciated ! > > Anders > > ------------------------------------------------------------------------- > Take Surveys. Earn Cash. Influence the Future of IT > Join SourceForge.net's Techsay panel and you'll get the chance to share your > opinions on IT & business topics through brief surveys - and earn cash > http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
