Hi all, I got my x-axis servo motor mounted today and ran some tests. There is a video and some hal-scope screen shots here: http://www.anderswallin.net/2008/04/x-axis-test/
This is a system with no motor current, motor voltage, or velocity feedback. An m5i20 generates PWM output for pico-systems DC-brush amps and 4000 pulse/rev encoders provide feedback. This might make the system a bit different to tune from other systems which run another loop on current/voltage/velocity. I found FF1 worked quite predictably and reduced the cruise-phase error to very little. Only P and FF1 was needed for that. (2nd pic on page) Then I added a lot of I-gain which helped a bit for the acc/dec phases. With FF2 I became confused on a higher level (3rd pic on page). It seems to either fix the acc. phase or the dec. phase but not both. The last pic shows moves at different feed-rates. All of them show around 16 to 25 count spikes during the acc/dec. phases. Presumably at the moment when acceleration changes and jerk is infinite. How much have other people been able to reduce these spikes? regards, Anders ------------------------------------------------------------------------- This SF.net email is sponsored by the 2008 JavaOne(SM) Conference Don't miss this year's exciting event. There's still time to save $100. Use priority code J8TL2D2. http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
