Hello Tom.
I have been playing with the Kflop and Snap Amp combination Trying to get a handle on servo tuning. I have been following along in the Optimizing Servo Tuning thread started by Judleroy. But I did not want to clutter his thread up with my pictures and questions as well.
This tuning is done with very little load on the shaft of the motor.
With Tom's Help calculaing.
Start of the caculation to figure velocity, acceleration and jerk
I wanted to start out at 100ipm
my encoders are 1250CPR or 5000pulses/revolution
ball screws are .125 lead
1inch/.125" per revolution= 8 revolutions per inch
8 x 5000 = 40,000 pulses per inch
Settings to enter into Step Response
Velocity = (desired feedrate/60) x steps per unit(number of encoder in a inch)
( 100ipm/60 ) x 40,000
(1.666666667) x 40,000 = 66666.66 rounded up to 670000
Acceleration = 2 x velocity = 133333.3333 rounded to 133000
Jerk = 10 x Acceleration = 1333333.333 rounded to 1330000 or 1.33e+006
This is how I understand the math for these settings.
Now for max limits
I think it was mentioned
OUTPUT = MAX Current/1024 or 35/1024 = 0.034179688amps/per bits
so 200 x 0.034179668 = 6.8359375 amps max output. Is this right?
Is this where you would set constant current limit?
INTERGRATOR = limits the amount of output to this number. so
anything that is put into P,I,or D. the output
(green line) is limited to a max swing of this
Setting. Is this correct?
ERROR = Position error Is this correct when ever the encoder
and comanded are not with in this setting it will fault
Is this correct?
Feed Forward
Velocity = ?
Acceleration = ?
Not sure when to use these or how to calculate what is needed.
I have attached a few of pictures of my tuning attempts. step responce and bode plot. I don't understand how to read the bode or what it is telling me.
And how would I fugure up filters for improved responce. I tried the setting for a lowpass filter on the other thread and it sent the servo into violent oscillations. so took that out.
Thank you
Rob