On 1 November 2012 06:51, EBo <e...@sandien.com> wrote: > > OK Now the question is should the ferror be calculated based on the > current encoder position, or the PID on the previous position? >
The PID error has a well-defined meaning, and is the difference between the current command position and the current feedback position. This will, of necessity, be non zero during any active control. (Because if PID error is zero, PID output is zero). I am not sure that the current f-error calculation is wrong. There was a new command position. The system moved for a servo period. The f-error is how closely the new position matched the commanded position. PID-error looks forward, f-error looks backwards. I think the aim is to reduce F-error rather than PID error, because PID error is what makes PID output. -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto ------------------------------------------------------------------------------ Everyone hates slow websites. So do we. Make your web apps faster with AppDynamics Download AppDynamics Lite for free today: http://p.sf.net/sfu/appdyn_sfd2d_oct _______________________________________________ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers
