On 13 January 2012 06:05, Jon Elson el...@pico-systems.com wrote:
I will have to try negative D values to see what they might do.
D might want to be negative or positive, depending on what you are
trying to achieve. You can use it to help catch a fast-moving setpoint
(positive D) or to reject
On 01/12/2012 10:05 PM, Jon Elson wrote:
I was just perusing some of the EMC docs, and wound up on the PID
hal component docs and source. I have never quite understood the
behavior of
the D term.
To (over) simplify:
error = commanded - feedback
errorD = error - previous error
output =
Karl Cunningham wrote:
I assume from your results there is a typo in the feedback -- it should
have been 4.9 this cycle and 4.8 last cycle. So
Terribly sorry, YES, that is what I MEANT to type!
If I'm missing the boat, please let me know.
Maybe I'd better refrain from doing even SIMPLE
I was just perusing some of the EMC docs, and wound up on the PID
hal component docs and source. I have never quite understood the
behavior of
the D term.
To (over) simplify:
error = commanded - feedback
errorD = error - previous error
output = error * P + errorI * I + errorD * D
Let's look at
