AIA Loops. What are they all about?

[Keith D]

I'm probably sticking my neck on the chopping block here, but here goes anyhow.

Has anyone here really worked with adaptive integral action control loops? I see these are a feature on the Honeywell
spyders and most of the larger controls companies have some sort of likewise offering.

Now I have spent a many few years dealing with PID loops and I like to think I have a good understanding of what flavour to pick and how to set one up. Then this AIA thing comes along and presents itself as another option.
My problem is that whoever I ask, either has not heard of them or keeps well away because they are in the same boat as me and do not really know enough about them, so I stay in a kind of limbo; not wanting to risk using them on a floor full of fan coil units in case it all goes wrong.

I did pick up a snippet of info once that their real benefit is in VAV terminal unit volume damper control. I could see this point, as I have many times witnessed the ever hunting belimo actuator on vav unit trying to keep a stable airflow when supplied by a badly installed primary air supply. the deadband and minimum analog output feature could well settle the actuator down and allow a small amount of offset to exist.

A Google search returns fairly sparse results in regard to HVAC applications.

Does anybody have any feedback?

[digo]

Has anyone here really worked with adaptive integral action control loops?

In the HW buildingsforum, under Lon Spyder, look for the "Spyder AIA Function Block" tech tip.
Positive experience with flow control is all I have.
Supposedly suitable for mixed air and modulating discharge air temp control with sequenced heating and cooling.

NOT suitable for water loop DP, Bldg Pressure, Duct Static, or Room Temp control.

Adaptive Integral Action is not to be confused with Auto Tuning. "The method of the adaptation is fixed but is adjusted/optimized by the parameters entered."

[viceman]

i did spyders a few years back. i tried the aia a few times and never had much luck with them. i tried it on mixed air control and a steam valve. i quickly abandoned it and never used it again.