DSPMC Feedforward CFF and CDFF gains

[piv]

Does anyone have a definition of CFF and CDFF or a picture of the control loop that the DSPMC is using?

Has anyone had success with CFF or CDFF and what kind of values were used or what method did you use to find/calculate them?

FYI im using a linear motor, Elmo servo drive, operating in current control mode.

[Chestermarine]

Hello PIV:

Aside from using AxisWorks to tune the servos driven by dspmc, I have no experience. However, there are a lot of tutorials on the net, and much on WIKI, that explain the meaning of the multitude of terms in PID tuning.

AxisWorks helps to get the numbers in the ballpark. The motor sound tells a lot about how good the numbers are, as well as a good curve on the graph. There are commercial tuning programs available.

Having read many of the tutorials on the subject, it is clear that the PID tuning process involves a lot of trial and error, and patience. 

I came across a couple of good tutorials with graphical examples of the various tuning parameters.

http://digital.ni.com/public.nsf/allkb/806F6F0B775FAF32862572FA0052F2AB

http://zone.ni.com/devzone/cda/tut/p/id/2923

John

[piv]

Hi John,

Thanks, those are great documents. Ive got P, I and D set up pretty well but CFF and CDFF are not behaving like I thought they might so my thoughts are wrong!