James Beall and Forum's experts
About Integrating Process response's Tuning, I met some problems. There is a article about Integrating Process response by James, Based on this articles: "Kp = (final slope – initial slope)/ Δ%OUT", I calculate My KP as follows:
First time, I gave a 20% Step Out, then measure PV value's slope, First Slope=1.994, Second, I gave a 10% Step Out and test it's slope again Second Slope=0.922, I think the Δ%OUT=10%, Then I calculate my Kp=(0.922-1.994)/10%= -10.72 , Based on this test result I got the Integral time and Controller gain, but these parameters cannot let my PID reach stead state. I think Root Cause is my Kp value. I noticed James's Kp= 0.000216, it's very small, but my Kp value is big, I think my calculation exist problems.
In addition, I notice James's APD=30 Percent, How to select the APD value, it's value=Dead time?
Another question: How to select MLD, I notice the article using 40%, this value is a experienced Parameter?
I will appreciate if you can give me a help.
Best Regards
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