I have something to add to this thread.

Just giving KFLDIMX the "WGDC value to reach target" is not going to give good results when the wastegate behaviour (KFLDRL) is fairly non-linear.
This is because after initial ramp up most of the duty cycle comes from I.

Now if for example at a point with a value of 70 KFLDIMX your KFLDRL reads 85, then effective WGDC will be way too high, as the 70 maximum in the KFLDIMX map will be "amplified" up by KFLDRL, resulting in a 85% max DC at that value, and not 70%.

The solution is to reverse lookup the "WGDC value to reach target" map through KFLDRL.

For example, taking the original resulting boost target -> wastegate duty map:


And running it in reverse through KFLDRL:


Results in:


This allows the PID to maintain much better control and all but eliminates overshoot on spoolup.

Does anyone keep pictures with prj's examples?

I don't understand, and I would like to see these pictures that aren't showing up.  I have seen how reducing the values of KFLDRL down to about 80% over 3000 rpm in the furthest column does get rid of the boost spikes on the freeway in the high gears, however it does seem to make spool slower in the lower gears, and does seem to make response slower as well in place of the over boost (pin the thorttle on the freeway and boost takes longer to build back up).

I think your definitions of P, I, and D are not very good :/

PID on ME7 as simply as I can think of it:

I -> Integral.  No need to go into integrals or calculus.  Stock coefficients Q1DY and Q1ST will output numbers that reach a limit in a very short amount of time.

We know that given intake air temperature (IAT), ambient pressure and humidity, once target boost is achieved, there is a WGDC that produces "X" amount of boost at "Y" rpm on a given engine/turbo/wastegate setup.

For all practical purposes there is a map for this and it's also the limit of that integral output above.  It's KFLDIMX. "X" boost is the X-axis of this map and "Y" RPM is the Y-axis. 

P -> Proportional.  P maps are Q0DY = dynamic and Q0ST = Static) and are a proportion of boost error.  What level of boost error divides them?  This is defined by UMDYLDR.

Q0DY allows rapid correction of large boost errors and flexibility on spool and change in throttle for different gears, IAT, and altitude (more specifically ambient pressure), each of which cause target boost to be reached at a different RPM.   

Q0ST needs to be large enough to make effective changes to WGDC (KFLDIMX), once target boost is attained.  Too low and adjustments won't be adequate and boost will stray from target.  Too high and boost will fluctuate around target (sine curve-ish).

SO:
I effectively gives a base WGDC
P gives the positive/negative change for flexibility to correct all errors very quickly.

D -> Derivative.  P and I are plenty potent enough to control boost but tuning will be a compromise between slower response near where error approaches zero and overshoot the target.   Hence, the Derivative Component.

D is used to "dampen" boost with a lower WGDC just before that larger error closes on target boost so you don't overshoot/undershoot your target.  The map KFLDRQ2 needs to be adjusted to be active at the rpm close to and above where your boost starts to meet requested and just large enough and at error values to eliminate overshoot.   

Now finally, KFLDRL.  Boost Linearization.  WTF is that?   In the RPM range that requested boost can be reached, there is no need for the full range of 0% to 100% WGDC.   This is where KFLDRL comes in. The map serves to magnify the area of WGDC that effectively makes a difference in controlling boost.   

It's impossible to understand PID and how it all works together without spending the time to see how changes in each component affect boost and wastegate duty cycle.   Start at the beginning of this thread and log, log, log.

Just as important, all that logging at different fixed WGDC to build your KFLDRL map will provide nearly all the data points to adjust the other PID maps for your setup.

Hope this helps.

Definitely. Take some logs using KFLDRAPP, use the spreadsheet to populate KFLDRL, and then reverse lookup DIMX values from logs.

Greetings ,

On the stock S3 BAM ECU , 366847 , KFLRAPP is already filled with zeros , any reason why ? I assumed this map is used to test purposed only when CWMDAPP is configured to 8 so it didn't matter , correct ?

Also , why did you need to log various gears , in my case I could get good resolution using ME7 logger in 3rd gear at WOT ? I could do this on my pal's dyno .. however that's also a pain ..
I guess the road is the best ..

Thanks