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Closed loop boost control problem


Highlift

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Why does the positive integral term reduce the duty cycle instead of increase it for the boost target error in this run?

The base wg duty cycle from 4000rpm on is 30%. The positive I term is reducing the base wg duty cycle when it should be increasing it.

Settings used are in the bottom picture.

link_boost.thumb.jpg.6e0883877f9dcef3901link_boost_settings.thumb.jpg.b3da40d911

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Did you tune it open loop first? Need the base table close to reality before you do CL

You have set the "i" to do all the work and its clamped to 15%.

Need to tune the P also and possibly the D.

Also raise the Stage one duty...

Did you read the helpfile?

Edited by Steve
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Hi Highlift,

Do you have the actual log file that you can upload?

Looking at the current values in the log file you appear to be in stage two of closed loop boost control. In this stage the ECU uses P Gain and D Gain along with the value from the wastegate DC% table. Looking at your settings you have the P Gain and D Gain set to zero. Try putting some values in here and see if the system then moves the wastegate duty cycle to try and achieve the target. You might also try a higher 'Stage 1 Duty', this will commonly be aorund 80 or 90%.

Scott

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