Deadband

I was wondering if anyone would have a calculation to establish a value for my "deadband" . I have read the section in the integrators manual and see the formula if using encoders, but we have resolvers on our machine, and i was not sure how to go about the math to establish a starting point.


Thanks

Rick

Deadband sets how much either way of my commanded position it is allowed to deviate from correct?

LAIR82 wrote:

I was wondering if anyone would have a calculation to establish a value for my "deadband" . I have read the section in the integrators manual and see the formula if using encoders, but we have resolvers on our machine, and i was not sure how to go about the math to establish a starting point.


Thanks

Rick

Take whatever your resolver converter produces when converted to axis units
and multiply by 1.5 for a starting value. So, if you have 4096 counts/rev and
a 5 TPI leadscrew, then your resolution is 1/(4096 * 5) = 0.0000488 inch.
So, a good starting value would be 7.32E-5
You want to keep this value as small as possible while suppressing annoying
servo dither. If it is too large, it adds a discontinuity in the servo transfer
function as it crosses zero, and can make the loop unstable.

And, of course, if you DON'T have any dither, then use zero.

Jon

I set it to zero and started from there going down on the count until it got "nervous" and then backed off a little bit. Nice and quiet now and no jitter on the display. The servo was humming before and I think it was "hunting" and I just did not realize what it was actually doing.


Thanks


Rick