On 21 December 2012 08:42, Viesturs Lācis <[email protected]> wrote:
> What I observed is that pid got saturated as the motor was 20-30 > degrees from its commanded position. I guess that tuning is pretty > tight. Actually, that doesn't sound particularly tight. I would expect to be hitting full scale rather earlier than 30 degrees of shaft movement. > How can I make those lines smoother? I am trying to play with P, I and > D, but I do not see any improvement. I can get the overall ferror > bigger or smaller, but I would like to make the line itself smoother - D _ought_ to damp the movement. I would try increasing that, then try some more P too. > This motor moves the Z axis, which has plasma torch mounted > on it, so the load should remain approximately as it already is there. It is possibly worth looking at what the steady-state duty-cycle is, (ie what PID output is needed to support the weight of the head) then put that value in the PID bias (or is it called offset). That should allow the PID to operate more symmetrically. -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto ------------------------------------------------------------------------------ LogMeIn Rescue: Anywhere, Anytime Remote support for IT. Free Trial Remotely access PCs and mobile devices and provide instant support Improve your efficiency, and focus on delivering more value-add services Discover what IT Professionals Know. Rescue delivers http://p.sf.net/sfu/logmein_12329d2d _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
