Hello, folks! I would appreciate some advice on servo tuning. I have Keling Nema23 BLDC servo motors attached to Mesa 7i39. And also zero experience with this :)
The way I am doing the tuning is: 1) start Emc, hit F1 and F2; 2) open Machine -> Calibration; 3) change P value, for example, from 1 to 3, press "Test" and then try jogging the joint; 4) my target max velocity is 10m/min, which would require 4000 rpm on motor, so I start jogging at 1100 mm/min - seems fine, increase speed to ~3000 mm/min and motor starts oscillating; When motor starts oscillating, I hit F2 to disable any movement and motor stops; So here I would like to change some PID values and then try again. The problem I have encountered is: Motor starts oscillating again as soon as I hit F2 regardless of what are the PID settings. If I restart Emc and start over, it is fine with the same PID settings until the moment it gets a chance to start oscillating again - then I cannot stop it from doing that. Setting PID values back to default also does not help - it will oscillate anyway. Why on earth would it oscillate as soon as motion is enabled? Is there a way to aviod it? Default PID values are: DEADBAND = 0.000 P = 1 I = 0 D = 0 FF0 = 1 FF1 = 1 FF2 = 0 BIAS = 0 I have been playing only with P parameter so far, following this guideline: 1) increase P up to the moment, when motor becomes unstable; 2) add I to make it stable; 3) add D to make the loop stiffer; In my previous attempts I had: DEADBAND = 0.0005 P = 90 I = 40 D = 1,65 FF0 = 0 FF1 = 1,5 FF2 = 0 BIAS = 0,0005 >From previous discussions I recall that FF1 should be very close to 1, like 1,001 or something like that. Since I have it larger, I decided to start over, because the motor still was oscillating at 2700 mm/min. Viesturs P.S. How hard would it be to create some kind of auto-tuning routine? ------------------------------------------------------------------------------ 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
