Tuning Boost Control With Bias Table

[aidandj]

I've found minimum duty is not as important. And it will constantly be stuck at the minimum duty. The point of setting max duty is to keep integral windup at bay. Setting max duty made the biggest difference so far. Along with setting the freq to 19.5Hz.

[muythaibxr]

Keep bumping up the duty until it affects boost. Then set the min slightly lower (1-2%) than the smallest number that affects boost.

[muythaibxr]

I've found minimum duty is not as important. And it will constantly be stuck at the minimum duty. The point of setting max duty is to keep integral windup at bay. Setting max duty made the biggest difference so far. Along with setting the freq to 19.5Hz.

We need to fix the min duty issue so that off boost it uses 0% instead of the min.

Ken

[aidandj]

Keep bumping up the duty until it affects boost. Then set the min slightly lower (1-2%) than the smallest number that affects boost.

Is the solenoid supposed to constantly be at minimum? Even when not targeting boost? My solenoid just clicks and gets hot if I set minimum over 0%.[/s]

EDIT: Saw your last post

[muythaibxr]

Here is a test version of beta 15 with less sensitive boost control.

Ken

[E30_Driv3r]

Awesome. Will load this up and test/log this afternoon.

[E30_Driv3r]

I think lowering the overall sensitivity will help in my case. I could test the change as early as this weekend. Now that you mention it, it does seem like my setup is very sensitive especially if I set the slider to zero and the code still so aggressively tries to reach my targets resulting just overboost every time.

I think a lot of your problem is that you have the lower limit delta set too high... so when PID engages, it's really far from the target, and its trying really hard to get up to the target by blasting the duty as high as it will go.

You're also likely suffering from the same windup problem that aidandj was suffering from. Lowering the max duty will help with that.

Ken

I will also try a lower delta number as well. I will start at 30 and work my way up if needed.

[aidandj]

Try even lower. 20 worked well for me 10 was too low it would go in and out of closed loop.

[E30_Driv3r]

Try even lower. 20 worked well for me 10 was too low it would go in and out of closed loop.

If 20 worked for you I'll start from there.

[E30_Driv3r]

Typing this from my iPhone so I can't show logs but just tested out the "test" code and finally basic mode works for me! I have my slider at about 118. I have a bit of initial overshoot but working on tuning that out. After the overshoot I'm -/+ 2-5kpa of my target. 20kpa lower limit delta was too low and I was hitting overboost protection. 30 seems to be working with no overboost even when shifting fast between gears. If I get the initial overshoot tuned out I don't think I'll need to even use advanced mode.

Will continue to log.

[aidandj]

Great news! I can't wait to try it out.

[E30_Driv3r]

Well. I made a small adjustment to my bias table but its not enough to flatten out the overshoot, I'm thinking:

-Go advanced and start at 100-100-100 and tweak D to fight off the initial overshoot.
-Increase delta? this is probably not recommended.
-play with the slider? I think its pretty good as is as it does sit right on target once settled from the overshoot.

Thoughts? Every once in awhile I will hit overboost protection shifting gears as well.

At this point however i'm excited it works!

[muythaibxr]

Good to hear it is working better. As for the overboost. I would follow the tuning method I outlined for aidandj. Doing this may let you reduce your lower limit delta.

[muythaibxr]

Next beta will also have a fix for the valve going to min when off boost. Instead it'll shut off to 0% when not in boost (Closed loop).

[aidandj]

Next beta will also have a fix for the valve going to min when off boost. Instead it'll shut off to 0% when not in boost (Closed loop).

Will the next beta also have the slider changes? Or should I use the test code?

[muythaibxr]

Yes next beta will have those changes, but if you want to try without waiting for that you can try this test code.

[aidandj]

I'll give it a shot tomorrow.

[aidandj]

Here are some logs with different slider settings. The log name tells you the slider setting in order.

[aidandj]

I'm pretty happy with this one.

Slider setting: 225

[muythaibxr]

That is certainly looking better.

Was that with Basic mode?

nathaninwa: Could you give this code a shot? IT's going to require retuning the slider for you probably and I want to make sure you can actually get it working properly.

You should be able to leave the PID numbers alone and just adjust the slider up to get back the old behavior.

Ken