All interested in Servo Tuning. Have a look at: http://support.motioneng.com/Downloads-Notes/Tuning/default.htm
Regards, Noel. -----Original Message----- From: Viesturs Lācis [mailto:viesturs.la...@gmail.com] Sent: Saturday, January 28, 2012 1:25 AM To: Enhanced Machine Controller (EMC) Subject: Re: [Emc-users] Servo tuning - wtf? Hello! I have spent some time with the machine and have tried some of the suggestions. 2012/1/27 andy pugh <bodge...@gmail.com>: > > At that speed with a 2-pole motor a 1ms servo period ought to be OK, > but you should try 500uS to see if that helps. > This was the only thing that helped - I reduced servo period to 500 us and the motor oscillation borderline shifted from 3660 mm/min to 5114 mm/min. Reducing servo period down to 250 us did not provide any additional improvement. > > What happens if you disconnect the PID (and the motors from the > machine!) and setp bldc.0.value 0.95 ? > I did the following: # net motor.00.command pid.0.output => bldc.0.value setp bldc.0.value 0.95 Result: nothing. Motor does not move. If I change back: net motor.00.command pid.0.output => bldc.0.value # setp bldc.0.value 0.95 Then I can jog motor. I tried 3 times switching back and forth - with PID disconected and BLDC value set to 0,95 motor does not move. 2012/1/27 Peter C. Wallace <p...@mesanet.com>: > > So if you set the PID comps MAX_OUTPUT to 158 (and PWM scale is > 166.67) that will limit maximum PWM to the desired 95% > I reduced those values and also set max output to be less than 95% of output scale: OUTPUT_SCALE = 125 OUTPUT_OFFSET = 0.0 MAX_OUTPUT = 118 It did not provide any additional improvement. So this far only reducing servo period did help. Unfortunately that is coming with RTAI error warning messages. I ran latency test for a while and got 12000 ns max jitter on servo thread. Viesturs ---------------------------------------------------------------------------- -- Try before you buy = See our experts in action! The most comprehensive online learning library for Microsoft developers is just $99.99! Visual Studio, SharePoint, SQL - plus HTML5, CSS3, MVC3, Metro Style Apps, more. Free future releases when you subscribe now! http://p.sf.net/sfu/learndevnow-dev2 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------------ Try before you buy = See our experts in action! The most comprehensive online learning library for Microsoft developers is just $99.99! Visual Studio, SharePoint, SQL - plus HTML5, CSS3, MVC3, Metro Style Apps, more. Free future releases when you subscribe now! http://p.sf.net/sfu/learndevnow-dev2 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
