Joint 0 on limit switch
18 Jan 2013 09:49 #28792
by cmorley
Replied by cmorley on topic Joint 0 on limit switch
In your config's main hal file, can you check for a line something like this line:
net x-vel-fb => pid.x.command-deriv
It should be changed to:
net x-vel-fb => pid.x.feedback-deriv
The other axes are similar.
This is a bug that was fixed awhile ago but has not been released yet.
It makes good servo tuning impossible.
Chris M
net x-vel-fb => pid.x.command-deriv
It should be changed to:
net x-vel-fb => pid.x.feedback-deriv
The other axes are similar.
This is a bug that was fixed awhile ago but has not been released yet.
It makes good servo tuning impossible.
Chris M
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18 Jan 2013 10:23 - 18 Jan 2013 10:24 #28793
by marsheng
Replied by marsheng on topic Joint 0 on limit switch
Whooha
That has completely freaked out my motors.
Ok, For testing I'm using some ex-printer motors. 15 volt, 4 amp with 500 cpr encoders. They are quite light weight motors but very good quality ones (Cost me a whole $10 from a computer wrecker. I bought 12 of them)
What do you suggest I use to start with for the motor tuning.
With net x-vel-fb => pid.x.command-deriv and P=1 I=0.05 D=0.01
it was quite good.
net x-vel-fb => pid.x.feedback-deriv
That has completely freaked out my motors.
Ok, For testing I'm using some ex-printer motors. 15 volt, 4 amp with 500 cpr encoders. They are quite light weight motors but very good quality ones (Cost me a whole $10 from a computer wrecker. I bought 12 of them)
What do you suggest I use to start with for the motor tuning.
With net x-vel-fb => pid.x.command-deriv and P=1 I=0.05 D=0.01
it was quite good.
Last edit: 18 Jan 2013 10:24 by marsheng.
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18 Jan 2013 11:03 #28794
by cmorley
Replied by cmorley on topic Joint 0 on limit switch
I will let others counsel you on PID tuning (it's kind of an art).
Though it might help to know your analog max scaling ( A PNCconf term for PWM scale)
It's scaled to 10 by default which is voltage.
And I think you are using velocity mode Copley amps that have there own feedback ?
In other words the encoder or a tach is connected to the Copley amp?
and Linuxcnc sees it's own encoder or a copy of the amps encoder?
Chris M
Though it might help to know your analog max scaling ( A PNCconf term for PWM scale)
It's scaled to 10 by default which is voltage.
And I think you are using velocity mode Copley amps that have there own feedback ?
In other words the encoder or a tach is connected to the Copley amp?
and Linuxcnc sees it's own encoder or a copy of the amps encoder?
Chris M
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18 Jan 2013 11:39 #28795
by PCW
This is the correct connection, if it freaks out your motors it
is because you have too much D term
(you may not need any if the drives have tachometer feedback)
Replied by PCW on topic Joint 0 on limit switch
net x-vel-fb => pid.x.feedback-deriv
That has completely freaked out my motors.
This is the correct connection, if it freaks out your motors it
is because you have too much D term
(you may not need any if the drives have tachometer feedback)
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