Well, the derivative part is distance/time dL/dt so that MUST BE velocity dependent!!! That is rate of change correction factor or so.
The Integral is cummulative, going slowly up/down. The output of I part of the PID is rising or falling with rate dependent on the difference between input values. The Proportional, is well, eh, PROPORTIONAL, taking part of the input value difference and putting it out. On 1/8/07, richard harris <[EMAIL PROTECTED]> wrote: > Hello, > > I am attempting to tune my machine, running rutex drives and emc2. > I command a drive to move 8 inches one direction reverse and return to zero. > G1 X-8.0 F10 G1 x0.0 F10. When I test with a dial indicator if the machine > returned I see that I over traveled .005". I retuned the drive and > increased the "i" value and adjusted p and d to reflect the increased i. I > rerun my 8 inch test and find I returned to zero. > I then run the same test but with twenty inches of motion and find myself 2 > thousands short. Just to see what would happen I increased my feed rate from > 10 to 15ipm. Suddenly the machine returns to zero. I increased the feed to > 30ipm and I overshoot. > It appears that I have a velocity dependent situation. I honestly have > little background in PID tuning, is this a drive tuning issue or is this an > EMC config issue? I am using the sample_inch.ini config and have only > changed the steps per inch, reduced the max acceleration, and max velocity > to reflect my machine. > > Thanks, > > __________________________________________________ > Do You Yahoo!? > Tired of spam? Yahoo! Mail has the best spam protection around > http://mail.yahoo.com > ------------------------------------------------------------------------- > 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 > [email protected] > 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 [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
