Hello Firstly another time many thanks for your help !
Yesterday the kbmg was delivered after so much waiting and i'm really happy (with your help) now the motor run again and i have now both direction !!! Finally i have do some little change in the proposed config like use more pwm scale (140) and allow more max_output (60) with a offset 64 (~DAC at 0rpm). and added a limit2 component on the pid.command, the result seems to be good : asked RPM can't be more than 3300 for pid input, and pid is able to deliver more power for compensation. (in other way ask rpm higher than max_output saturate the pid) I can reach the max rpm with some DAC output near +-8.5v. I need to study PID now because is really not perfect (maybee too slow) for now with these default settings P = 0 I = 1.0 D = 0.0 FF0 = 1.0 FF1 = 0.0 FF2 = 0.0 BIAS = 0.0 DEADBAND = 0.0 I have play a little with deadband, bias, FF0, I without big success. from linuxcnc forum PCW user says : > For the normal spindle in velocity mode I would use only FF0 and P and I, > and only add I when you are quite close to correct velocity following. > (FF0 only is pure open loop voltage mode with a PWM driven servo motor) > So for this mode I would get the spindle speed as accurate as possible > over the > full speed range with just FF0 and then add feedback with some P (as much > as it > stable) and then some I > > For position mode you use As much D&P (more D allows more P) as is stable > then > adjust FF1 for minimum following error vs velocity. Then finally add as > much I as is stable https://forum.linuxcnc.org/10-advanced-configuration/36891-need-help-adding-pid-to-advanced-spindle-config Maybee try to use http://www.linuxcnc.org/docs/html/man/man9/at_pid.9.html or Ziegler-Nichols method One things i'm unsure it is better to tune the kbmg firstly as best as possible with original potentiometer ? IMH with PID and limit2 component including max_accel i need to set the drive as : --maximum or near value for Max Facc Racc --default value or lower for FWD-CL REV-CL --tune value DB with enable closed and 0rpm ~0v DAC --tune as best IR-Comp RESP Br -- website: http://www.machinekit.io blog: http://blog.machinekit.io github: https://github.com/machinekit --- You received this message because you are subscribed to the Google Groups "Machinekit" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/machinekit/4f07a30d-673e-4a9f-ade1-af3263322414%40googlegroups.com.
