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does anyone in the Miata/Megasquirt-world have some first hand experiences with the new (I think type B?) PID in the newer MS3 firmware's?
How do you set this up correctly? It looks like it is way better working when set up - but as usual with Megasquirt, nobody gives you a correct tuning advice to beginn with.
Has anyone on here tried?
firmware 1.5.1 - PID Type C "The I-term seems to behave like the classical P-term, and the D like the classical I-term iirc. For my setup some I-term plus a little D-term seems to be all that's needed, P didn't seem to make any noticeable difference." from msextra
"These use a type “C” loop, and the P part doesn't get the system to converge on its own. So the third approach is the recommended one – you'll want to focus mostly on the “I” term." Matt Cramer DIYAutoTune Support
"It is recommended to start by tuning the 'I' term until the target is reached with minimal oscillation.Additionally, since the response of most wideband controllers and sensors is linear with AFR, a larger 'P' term can be used to help correct for fast changes in AFR. Caution must still be used however since there is a significant delay between the amount of fuel being injected changing and Megasquirt registering an AFR
change as a result.Finally, a small amount of 'D' term can be used to help slow response during very fast changes. This helps reduce overshoot of the target" from MS Manual
firmware 1.5.2 betas - PID Type B (Ideal)
I am not sure but should be like that
firmware 1.5.1 - PID Type C "The I-term seems to behave like the classical P-term, and the D like the classical I-term iirc. For my setup some I-term plus a little D-term seems to be all that's needed, P didn't seem to make any noticeable difference." from msextra
"These use a type “C” loop, and the P part doesn't get the system to converge on its own. So the third approach is the recommended one – you'll want to focus mostly on the “I” term." Matt Cramer DIYAutoTune Support
"It is recommended to start by tuning the 'I' term until the target is reached with minimal oscillation.Additionally, since the response of most wideband controllers and sensors is linear with AFR, a larger 'P' term can be used to help correct for fast changes in AFR. Caution must still be used however since there is a significant delay between the amount of fuel being injected changing and Megasquirt registering an AFR
change as a result.Finally, a small amount of 'D' term can be used to help slow response during very fast changes. This helps reduce overshoot of the target" from MS Manual
firmware 1.5.2 betas - PID Type B (Ideal)
I am not sure but should be like that
That is an excellent lil gif, have a poscat.
Now if we could get some actual gain scheduling going too...
Now, if you are cruising around and locked in at 90% correction and floor it into boost it will stay locked at 90% fueling till you return to your defined correctable conditions. Sure hope it don't vent the block.
Customer request. Don't like it? Suck it. There's no way to turn the "feature" off.
@ Deezums - So I guess this was your question at msextra:
Downloaded RC15, was surprised to see that ego correction remains at the previously calculated value when the AFR exceeds the AFR set in "And Correct Below:AFR".
So if EGO Corr is calculated at 90, and the AFR exceeds 16.0 ( "And Correct Below:AFR" is set at 16), ego Corr stays at 90 until AFR returns under 16.
Behaviour in 1.5.1 is if AFR exceeds this setting...EGO Correction turns off (100%).
Is this working as designed in RC15?
So - I think the margin for the EGO correction below AFR should be set quite high?
No, that one isn't me. Though I did post a similar one before that one, except mine was holding corrections while cranking after a stall. Any time it used to snap back to zero/100% on older firmwares, it now sticks at it's last value. I do not believe it respects the authority table, either. So if you give it 15% at cruise and 5% in boost, it can possibly run 15% under while in boost.
I've noticed this too, where the EGO correction "sticks", especially during transients. I've somewhat worked around it by using split authority tables and setting negative authority to zero in certain areas. It also seems to wreck VEAL to the point that I used autotune only for very coarse rough-in a few areas and then hand-tuned from logs. I was getting places, mostly in off-idle and lift-off decel at high RPM, where it was pulling or adding stupid amounts of fuel.
03-08-2021, 03:31 AM
Experiences with new PID type for EGO and idle?
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