959 B
959 B
- create a stepped schedule
200 220 200 220
- set i=0
- set d=0
- set p=5
run schedule if oscillation is sustained stop otherwise, double p
once oscillation is sustained
- record P as Ku
- record period of oscillation as Pu
set p=Ku/1.7 set i=Pu/2 set d=Pu/8
another method (for just PI control) https://pdfs.semanticscholar.org/e719/f259f6c93b9a897a214824e562c886aa80b9.pdf
use step schedule set d=0 set p=1 you should see some overshoot and barely observable undershoot if not, change p until that's true (up or down)
next measure T between high peak and low peak set i=T1.5 set p=.8lastp
p=1*.8 = .8 i=1040-315 = 725s * 1.5 = 1088
https://www.eurotherm.com/pid-control-made-easy
similar to above for PI
p=225=50 (that's 25F overshoot times 2) i=7251.5 = 1088 d = 1088/5 = 217