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Author Topic: Actual pre-control in LDRPID  (Read 37979 times)
prj
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« Reply #225 on: July 31, 2018, 12:50:22 AM »

Push it WOT 1000 rpm later and overlay the two graphs that you get.
If they are identical, then nothing to worry about, that's what linearization is for.

If they are not identical, and you have the same "mountain" in a different place, then your wastegate preload is so high that you've limited the available wastegate travel and the wastegate is unable to open fully.
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aef
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« Reply #226 on: July 31, 2018, 01:35:10 AM »

great explanation, thank you prj

can fueling have such a great influence on the boost? I mean extremely lean/rich which influences spool?
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prj
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« Reply #227 on: July 31, 2018, 03:31:04 AM »

great explanation, thank you prj

can fueling have such a great influence on the boost? I mean extremely lean/rich which influences spool?
Not really.
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cgramme
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« Reply #228 on: July 31, 2018, 10:44:09 AM »

Push it WOT 1000 rpm later and overlay the two graphs that you get.
If they are identical, then nothing to worry about, that's what linearization is for.

If they are not identical, and you have the same "mountain" in a different place, then your wastegate preload is so high that you've limited the available wastegate travel and the wastegate is unable to open fully.

Thanks for the help, prj. I have a few graphs I overlaid at 30% wgdc, two in 2nd gear and one in 3rd. If I tried to tune KFLDRL it would be unstable depending on what gear im in, because there is at least a 250 rpm difference in when boost comes on. I'm going to assume it is my wg preload being too high, because I did tighten it a few months ago.
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prj
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« Reply #229 on: July 31, 2018, 01:19:02 PM »

Looks normal enough to me and easily linearizeable with KFLDRL.
Of course it would be easier if the response was more linear.
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!nfern0
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« Reply #230 on: August 12, 2018, 09:31:19 AM »

Hello all together,

I had some issues with some copy paste errors and was sometimes confused and changed the wrong areas when fine tuning the PID. So I made a simple excel sheet.

Here you can:

1. Insert your pressure axis and I values like in the LDRPIDTool
2. Insert your generated KFLDRL (or out of your tune/bin file)
3. Put a desired pressure and engine speed and see which WG DC comes out of the maps

At least for me it's useful to check very fast if all the values are giving me the DC I want at the end. Maybe some of you could use it too. I don't give you my word that it's 100% bug free  Grin
attached the file and screenshot.
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Dejw0089
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« Reply #231 on: January 20, 2019, 06:16:12 AM »

Can anyone tell me what profit i has when edited IMX and DRL on stok k04-23 turbo? If I understand good it's for beter working of PID controller? So i can ignore original maps and make IMX linear and then altered DRL for new IMX map?

I edited KFLDIMX map to linear and I get somethink like this
« Last Edit: January 20, 2019, 11:57:32 AM by Dejw0089 » Logged
Gaghunfv2
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« Reply #232 on: January 21, 2019, 05:43:21 AM »

Read the thread and you will find out...
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Dejw0089
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« Reply #233 on: January 21, 2019, 11:04:38 AM »

Read the thread and you will find out...
I read but i think better to ask because english is not my National language so better to ask not only do everything wrong. So I must linearize imx then set CWMDAPP to 8 and set in KFLDRAPP to my fixed dc for log yes?
« Last Edit: January 21, 2019, 11:08:34 AM by Dejw0089 » Logged
stein
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« Reply #234 on: January 21, 2019, 08:48:41 PM »

I read but i think better to ask because english is not my National language so better to ask not only do everything wrong. So I must linearize imx then set CWMDAPP to 8 and set in KFLDRAPP to my fixed dc for log yes?
This isn't really a direct answer to your questions, but hopefully it helps fill in gaps that maybe can help you answer your own questions. Or maybe you already know this. Anyway:

In general the theory here (with pre-control, aka feedforward) is that if you know how your system responds, you can be more aggressive with your control inputs "ahead of time" rather than the reactionary nature of feedback (PID in this case) control, which relies on reading measurements of the system state and using those to determine what control input to use. In this case, you know approximately what boost control solenoid inputs cause what boost pressures at various operating states.
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Dejw0089
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« Reply #235 on: January 22, 2019, 03:08:17 AM »

This isn't really a direct answer to your questions, but hopefully it helps fill in gaps that maybe can help you answer your own questions. Or maybe you already know this. Anyway:

In general the theory here (with pre-control, aka feedforward) is that if you know how your system responds, you can be more aggressive with your control inputs "ahead of time" rather than the reactionary nature of feedback (PID in this case) control, which relies on reading measurements of the system state and using those to determine what control input to use. In this case, you know approximately what boost control solenoid inputs cause what boost pressures at various operating states.
Ok. I understand what is for but I'm still thinking how to log I mean i must set KFLDRAPP to DC which I want to log? I'm understand this correct?
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Gaghunfv2
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« Reply #236 on: January 22, 2019, 10:31:59 AM »

Please sit back and learn more before you try, you could easily kill your piston rods with too much duty cycle at once...
Sorry, normally I'm very helpful. But I won't explain it to you, if everything is explained above. And if you don't understand this then you won't understand my answer anyway.  Wink
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nyet
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« Reply #237 on: January 22, 2019, 10:34:55 AM »

Ok. I understand what is for but I'm still thinking how to log I mean i must set KFLDRAPP to DC which I want to log? I'm understand this correct?


No, you should start by learning how PIDs work. Do not touch any map until then.
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Dejw0089
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« Reply #238 on: January 22, 2019, 12:27:57 PM »

Please sit back and learn more before you try, you could easily kill your piston rods with too much duty cycle at once...
Sorry, normally I'm very helpful. But I won't explain it to you, if everything is explained above. And if you don't understand this then you won't understand my answer anyway.  Wink
I understand Your answer and what doing this maps. When we set in IMX map 70 % on all rpms is 800 mbar boost then axis in DRL maps is represent that boost and then we set on each rpms DC when that boost is reached for example on 2500 rpms is 95 DC but on 4500 is 70 DC so PID only compensate deviation from that pressure for reach desired pressure as we want to make. But I want to know how to log properly for LDRPIDtool tool. Do I need to set stable DC or I can just log with linearized IMX map and CWMDAPP to 8 or I need then set in KFLDRAPP map each axis DC in DRL map and repeat loging for each value and then I received properly DRL map.
I don't care about connecting rods because I has forged connecting rods.
And if I irritated you I'm sorry.
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aef
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« Reply #239 on: February 12, 2019, 06:29:18 AM »

What will happen if I log fixed 90 or 95% duty only until lets say 3500rpm. Will the tool use this logfile because there is WOT from start to 3500?
Or in general: should i log this 90% with a K03/K04 because it will overspool and get damaged maybe.

In PRJs first post there is 90% in the last column of KFLDIMX and 95% in the last column of KFLDRL.
I understand that you will have to set 95% in KFLDRL because of spoolup and for the absolut maximum duty.

Why is there 90% duty in the last column of DIMX? Is it because of the logic: the last column (pressure value) is higher than what you are planning to run so it doesnt matter if its 90 or 95?

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