Thank you Noel. Also for those interested in determining which one of six servo control system models their particular hardware falls into (so you know which parameters to change BEFORE tuning) buy this book: "Control System Design Guide" by George Ellis It helped me a great deal. Jim
----- Original Message ----- From: noel <[email protected]> To: 'Enhanced Machine Controller (EMC)' <[email protected]> Sent: Sat Jan 28 10:14:09 2012 Subject: Re: [Emc-users] Servo tuning - wtf? 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:[email protected]] 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 <[email protected]>: > > 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 <[email protected]>: > > 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 [email protected] 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 [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users This communication is for the use of the intended recipient only. It may contain information that is privileged and confidential. If you are not the intended recipient of this communication, the disclosure, copying, distribution or use hereof is prohibited. If you have received this communication in error, please advise me by return e-mail or by telephone and then delete it immediately.
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