PID controller setup issue

A

ArmenM

Joined
Mar 1, 2021
Messages
18
Hello everyone,

I recently finished my build on my heat treating oven. Got everything wired up and started. After testing the controller(inkbird itc-106hv) my temps are overshooting like crazy in low temps(200-600) I then set temp to 1200 and it got there pretty quick and it overshot to about 1200-1210. Soon as it drops below 1200 the elements don’t get energized. It goes down to about 1160 and then it energizes. It keeps on doing that every time. I’ve tried auto tuning, nothing worked. Tried messing around with P I and D settings and I’m completely lost on what values to put there. If anyone can please help me understand how to tune this pid I would greatly appreciate it!! Thank you!
 
What kind of thermo couple do you have? Fluctuating plus minus 10 degrees isn't a big deal. The thermo couple is just heating up quickly when the elements are on. If you worried about fluctuations put a heat sink in the oven like a thick bar of steel.
My diy oven with an ink bird isn't happy at low temperatures either. I just use a toaster oven.
 
With that drop to 1160 it sounds like the integral function might be biting you. Search for the thread titled “everything you wanted to know about PID”. It should give you some insight on the behavior you are seeing, and also how to adjust those settings (sorry, I’m on an iPad right now, otherwise I would supply a link to the thread)
 
It’s a
scott kozub said:
What kind of thermo couple do you have? Fluctuating plus minus 10 degrees isn't a big deal. The thermo couple is just heating up quickly when the elements are on. If you worried about fluctuations put a heat sink in the oven like a thick bar of steel.
My diy oven with an ink bird isn't happy at low temperatures either. I just use a toaster oven.
Click to expand...
K type thermo couple. I may do that it’s just a headache because sometimes it’ll over shoot by 20 and sometimes 50-80°
 
Thank you for the reply. I will search for it now. I think I just have settings dialed in incorrectly. And I don’t understand exactly what P I and D do
Cushing H. said:
With that drop to 1160 it sounds like the integral function might be biting you. Search for the thread titled “everything you wanted to know about PID”. It should give you some insight on the behavior you are seeing, and also how to adjust those settings (sorry, I’m on an iPad right now, otherwise I would supply a link to the thread)
Click to expand...
 
So I did read it but I’m still having issues dialing the settings in. I’ve gotten to the point where the temp overshoots about 40-50° over and then about 5-10° under before it rises up again so for example it’ll pass 700° to 740 and then down to 695 and then back up to 740 when it’s set to 700. My p is set to 10, I is 10, and d is 240.
Cushing H. said:
you might have found it .... but in case not, here is the link...
https://www.bladeforums.com/threads...anted-to-know-but-were-afraid-to-ask.1716843/
Click to expand...
 
I had to scrap my Inkbird PID and buy an Auber Instruments because it never would work correctly. After reading several online reviews, I noticed others having similar problems. If all else fails, it might be a junk controller.
 
ER Sheldon said:
I had to scrap my Inkbird PID and buy an Auber Instruments because it never would work correctly. After reading several online reviews, I noticed others having similar problems. If all else fails, it might be a junk controller.
Click to expand...
I might just do that too. Do you have a part number for the auber?
 
thx. getting better, spend yesterday sleeping or being useless. I managed to get **every* *single* *one* of the listed side effects (so did my son, who got the shot on the same day). Good thing the side effects are actually an indication of the shot actually revving up the immune system.... :-)
 
That’s good to hear! So I fed the remaining portion of the link you sent me. Very well written. However soon as you got into I and d It confused me. I do understand P now though. I just want mine to work where as soon as it’s getting close to set point temp that it gradually gets it there. Right now it’s just going 100% to set temp and turns off. Therefore overshooting and driving me nuts!
 
I can find just the inkbird-106 manual .... but not one for an "hv" model. Is the basic 106 manual applicable?
(want to see if I can make sense of how they are definging the tuning parameters...)
 
Cushing H. said:
I can find just the inkbird-106 manual .... but not one for an "hv" model. Is the basic 106 manual applicable?
(want to see if I can make sense of how they are definging the tuning parameters...)
Click to expand...
Oh .... never mind. I just spotted where the HV is indicated...
 
ArmenM said:
So I did read it but I’m still having issues dialing the settings in. I’ve gotten to the point where the temp overshoots about 40-50° over and then about 5-10° under before it rises up again so for example it’ll pass 700° to 740 and then down to 695 and then back up to 740 when it’s set to 700. My p is set to 10, I is 10, and d is 240.
Click to expand...
So - going back to this posting, where you had p=10, I=10, d=240, and refreshing my memory on the inkbird manual .... here is what I am thinking (some of which might be considered wild speculation. Like I said in the thread, I am really not impressed with the clarity of the inkbird manual. Also, like I said in the thread, I really do not trust the autotune algorithms, and suggest that you approach control at first with 1) proporitional band mainly controlling, 2) integral term minimized, and 3) derivative term minimized. My wild speculation is, just based on the units cited in the manual for the integral term and the differential term,that they are using the standard form of the PID equation, and that to minimize the integral term you want to make it really big, and on the other hand to minimize the differential term you need to make it really small. thus, your integral term of 10 out of 9999 means the integral term is highly active, and a differential term of 240, while not being as bad as it could, be, is definitely not zeroed out.

if my guess is right about their equation I would suggest:
  • set the integral term to 9999 (its largest value). This does not turn off the integral term, but makes its influence as small as possible.
  • set the differential term to zero (which should eliminate its influence).
  • then play with the proportional band term "P". I *think* that this, in their usage, is not closely tied to degrees width of the proportional band, but rather that it is an arbitrary number that multiplies the difference from setpoint, and any resulting value greater than 100 turns the output on "full". To test this, I would suggest setting the I and D terms as above, then set the proportional term to some big value .... say 500. What I *think* you will see is the oven being full on until it hits setpoint, then overshooting as you are now seeing. THEN set the P value to something really, really, small, like P=1. What I *think* you will see is a slow rise towards your setpoint, with the temperature leveling out at something less than then setpoint (unfortunately, the integral term can still bite you because the long slow rise to temperature can accumulate a lot of error, and the term just can not be turned off. If you get overshoot followed by oscillations, try bringing the oven up to temperature, then turn the controller off for 30 seconds. this should clear the accumulated error and stop the oscillations.
Let us know how it goes?

(I have definitely seen people with inkbirds that appeared to just be faulty .... struggling with them for a long time only to replace with Auber then having immediate success. But I figure it is worth just a little experimenting with the one you have to see if it can be gotten to work.....?? )
 
Last edited:
Cushing H. said:
So - going back to this posting, where you had p=10, I=10, d=240, and refreshing my memory on the inkbird manual .... here is what I am thinking (some of which might be considered wild speculation. Like I said in the thread, I am really not impressed with the clarity of the inkbird manual. Also, like I said in the thread, I really do not trust the autotune algorithms, and suggest that you approach control at first with 1) proporitional band mainly controlling, 2) integral term minimized, and 3) derivative term minimized. My wild speculation is, just based on the units cited in the manual for the integral term and the differential term,that they are using the standard form of the PID equation, and that to minimize the integral term you want to make it really big, and on the other hand to minimize the differential term you need to make it really small. thus, your integral term of 10 out of 9999 means the integral term is highly active, and a differential term of 240, while not being as bad as it could, be, is definitely not zeroed out.

if my guess is right about their equation I would suggest:
  • set the integral term to 1 (its minimal value). This does not turn off the integral term, but makes its influence as small as possible.
  • set the differential term to zero (which should eliminate its influence).
  • then play with the proportional band term "P". I *think* that this, in their usage, is not closely tied to degrees width of the proportional band, but rather that it is an arbitrary number that multiplies the difference from setpoint, and any resulting value greater than 100 turns the output on "full". To test this, I would suggest setting the I and D terms as above, then set the proportional term to some big value .... say 500. What I *think* you will see is the oven being full on until it hits setpoint, then overshooting as you are now seeing. THEN set the P value to something really, really, small, like P=1. What I *think* you will see is a slow rise towards your setpoint, with the temperature leveling out at something less than then setpoint (unfortunately, the integral term can still bite you because the long slow rise to temperature can accumulate a lot of error, and the term just can not be turned off. If you get overshoot followed by oscillations, try bringing the oven up to temperature, then turn the controller off for 30 seconds. this should clear the accumulated error and stop the oscillations.
Let us know how it goes?

(I have definitely seen people with inkbirds that appeared to just be faulty .... struggling with them for a long time only to replace with Auber then having immediate success. But I figure it is worth just a little experimenting with the one you have to see if it can be gotten to work.....?? )
Click to expand...
Thanks for the insight! I’ll definitely give the above a try and give you my input!
 
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