Stephen Wille Padnos wrote: > Jon Elson wrote: > >> This is pid2, but it still doesn't solve the quantization noise in the >> encoder-derived velocity. >> >> > Actually, it does. The Mesa encoder counter has a timestamp of when the > last encoder edge was seen, so the velocity is based on accurate (to > some fraction of a microsecond) time sampling, not the servo loop rate > (with its associated jitter). The same method is also used in the > software encoder module, though the jitter will be much worse since the > base thread is also subject to interrupt latency issues. > OK, I wasn't sure that this ALSO solved the problem at higher speeds, it is clear the time stamp solves the problem at the lowest speeds. I was under the impression that when the velocity was above one count per servo cycle, the velocity estimation was "phased out". Oh well, wrong again!
(My HARDWARE has this, but the driver doesn't use it, yet!) Jon ------------------------------------------------------------------------------ This SF.net email is sponsored by Sprint What will you do first with EVO, the first 4G phone? Visit sprint.com/first -- http://p.sf.net/sfu/sprint-com-first _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
