DBW feedforward and P & I controls

[SteveC]

Questions on DBW feedforward.

1. Is it best to configure the Feedforward table to just below the Target Aim Idle ?

the idle aim main is set to 1500 cold and 1250 warm so the feed forward table has 3 entries for rpm 1100 1250 and 1500

I have set this at running temps to be as close as possible but it fluctuates around the target - is this normal for dbw and Big CAMS.

2. what do configure next - the idle ignition timing limit advance control proportional and integral gain ??
or
Idle Mass flow Integral and proportional gain (I before P in the help)

Now i have played with the idle ignition timing limit advance control and got the idle close to idle aim main and its good.

If i blip the throttle i get hugh oscillation to stall with 0 entries are in the Idle Mass flow gains and no matter what setting i use it never goes away. so I at 160 and P and 0 as a start as per the help.

Any help would be good.

[Stephen Dean]

Hi,

Can you send the logging from this to support @ motec.com.au and I'll have a look at it for you.

Usually if the FF table is correct, there is minimal amounts of P & I needed (most vehicles that I have done just use the base settings).

The FF table usually has a larger number of cells in it than you have described.

[SteveC]

Motec idle 2.png (6.91 KiB) Viewed 3973 times

Idle Aim

Motec idle 1.png (7.42 KiB) Viewed 3973 times

Ramp rate

Feed Forward

Motec idle 3.png (13.97 KiB) Viewed 3973 times

More than 3 cells

[SteveC]

I will send over the config and log file shortly