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Air conditioner compressor load and idle up


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Air conditioner compressor load
and idle up

When the AC compressor clutch is connected while the car is idling at a standstill, the idling value will gradually decrease.


I have tried increasing the AC fuel correction a little, but there is not much change.
Is there anything else I can do to adjust the idle?

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In g4x you can increase your target idle rpm if you are running close loop idle control.

to go with that you should increase the value a bit in AC offset.

https://drive.google.com/file/d/1sXRUYuNwvMurabYIoaiBlnml4zIYfrdf/view?usp=sharing

if you are experiencing a rpm dip right when you turn on the AC you should increase the clutch delay.

https://drive.google.com/file/d/1A4pxclzBfgtxftpzlxn4TQ4g40xaM2E6/view?usp=sharing

maybe post you calibration file and a log that we take a look.

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Thank you very much.
I'm aiming for 850 rpm idle, but it stalls a bit, so I'm keeping it high.

I've tried my best, but idle control is difficult.

 

When I challenge the clamp value to work up to idle, the idle value jumps as soon as the AC compressor is turned off and does not return for a while.

On the other hand, if I lower the clamp too much, the idle will not increase.

I've tried adjusting the gain and throttle targets from the base position, but I can't figure out where to set it.

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Your idle overshoots because of too high PID values.

Try the following (in the screenshot).
*You also need to change the Idle Speed Control Max Clamp (you may need this a little bit higher) & Min Clamp (you may need this lower) accordingly. The idle base position values should be adjusted when AC off.

Idle.jpg

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Thank you.
I've made the changes and logged the data based on your advice.

What I'm wondering is that when the AC compressor clutch is disengaged, the idle goes high for a few seconds to 1500 RPM.

 

This is a log while driving with the air conditioner on.
If the idling value rises abnormally when the car is about to come to a stop, it can be dangerous, so I'd like to do something about it.

https://drive.google.com/file/d/12obUIP-TgK6O-4Dx9hunIHsOKgEwvja_/view?usp=drivesdk

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You have no output assigned to AC Clutch.  What is controlling the clutch?  In the log the AC request is off but you obviously have some load turning on/off that the ecu doesnt know about? 

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The clutch is controlled by the stock ECU.
The AC clutch and compressor are working.

Should I transfer all control to the LINK side?  The wiring is already done.

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You could try leaving the AC controled by the factory ecu, but connect a wire from the AC Clutch or relay to the ecu DI so that the Link ecu then knows when the clutch is engaged.  It wont work quite as well as it would with full ecu control but that may also be difficult depending on how complicated the factory climate control system is.  

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On 4/3/2021 at 4:05 PM, Adamw said:

You could try leaving the AC controled by the factory ecu, but connect a wire from the AC Clutch or relay to the ecu DI so that the Link ecu then knows when the clutch is engaged.  It wont work quite as well as it would with full ecu control but that may also be difficult depending on how complicated the factory climate control system is.  

I made it possible to control the air conditioning compressor on the LINK side.

However, only the idle up setting does not work properly.

Normal idling seems to have settled down.

The idle up setting with only the electric fan drive works fine, but I am having trouble with it.

 

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18 hours ago, Adamw said:

Can you try this map, I have changed many of your settings to more typical values.  Can you log some idle time with AC on/off and some throttle blips etc, I will make some further adjustments once I see the log.

1617581754051_LA400Kkurosiba16ttt idle test.pclx 428.5 kB · 2 downloads

Logged.
1 is A/C off and idle only.
The others were logged with the A/C on, but the car stalled and I could not get a good log.

 

 

Longer logs will be from Googledrive.

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Sorry for the slow reply.  

I see a possible problem in the way the AC offset is applied, it only gets added when the AC request is made, rather than added and removed everytime the AC clutch turns on & off.  So I may have to talk to the engineers about changing the way this works, but I still dont think that is all of the problem.  It is quite unusual for the engine to need 2% extra throttle to idle with AC on.  My car needs only 0.3% for example.  Maybe it is more difficult for the small, low torque engine.  

Your lambda is very erratic also, and I think that is due to the closed loop lambda rate being too high at idle.  Can you drop the closed loop lambda update rate to 1 as a test.  Can you also increase idle ignition max clamp to 35deg.    The MAP signal also seems to be very erratic at idle, im not sure if this is a function of the 3 cylinders?  Is the MAP sensor connected to a plenum?  Could you try setting the MAP filter to medium and see if that helps idle AFR too.  

Can you do a new log with these changes and attach your latest when done.

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Thank you very much.
The engine is made by Daihatsu.
KF-VET three-cylinder engine with a displacement of 660cc.


As you pointed out, the MAP value is unstable, but it is almost the same as the stock ECU.

I will adjust the MAP sensor filter, ignition clamp, lambda gain, etc. and try logging again.

 

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On 4/7/2021 at 5:59 PM, Adamw said:

Sorry for the slow reply.  

I see a possible problem in the way the AC offset is applied, it only gets added when the AC request is made, rather than added and removed everytime the AC clutch turns on & off.  So I may have to talk to the engineers about changing the way this works, but I still dont think that is all of the problem.  It is quite unusual for the engine to need 2% extra throttle to idle with AC on.  My car needs only 0.3% for example.  Maybe it is more difficult for the small, low torque engine.  

Your lambda is very erratic also, and I think that is due to the closed loop lambda rate being too high at idle.  Can you drop the closed loop lambda update rate to 1 as a test.  Can you also increase idle ignition max clamp to 35deg.    The MAP signal also seems to be very erratic at idle, im not sure if this is a function of the 3 cylinders?  Is the MAP sensor connected to a plenum?  Could you try setting the MAP filter to medium and see if that helps idle AFR too.  

Can you do a new log with these changes and attach your latest when done.

Good morning, sir.
I took two logs, one with the air conditioner on and one with it off.

Please help me.

 

https://drive.google.com/file/d/1TDlD-9yqQhfplDSXrFUJWji7nZQA_Y7Z/view?usp=drivesdk

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On 4/9/2021 at 1:13 PM, Adamw said:

Can I get a copy of your current tune too please.

One is the first map data that you reworked. (I've corrected the points you pointed out, such as lambda and idle ignition.

The other is the map data I'm currently using.
The other is the map data that I am currently using. I have managed to get it to work by having it read a different electronic throttle map when the air conditioner is running.
In the end of the YouTube video, when you open and close the electric roof with the air conditioner running, it becomes quite unstable.

I'm wondering if it's possible to turn off the air conditioner compressor when opening and closing the electric roof.
I'm trying to figure out if it's possible to digitally input the roof switch to the link.

 

 

The video shows how it works with the data I created.
I also tried to close the roof when the air conditioner is moving and get the log.

 

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On 4/9/2021 at 1:13 PM, Adamw said:

Can I get a copy of your current tune too please.

I've been trying to adjust the settings by referring to this page, but I'm still far from the standard electronic throttle settings.
It's hard to make a good adjustment.

 

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Good morning, sir.

General electronic throttle settings and
I tried a combination of general electronic throttle settings and throttle target value map switching.

I turned off the lambda completely to check the effect of the lambda, and it seemed to stabilize.

The engine stalled and stopped when the air conditioner was turned off.

I also took a log.
I turned off the lambda completely as an experiment.
During the measurement, I changed the dead zone from 10 to 30 and the integral gain from 0.05 to 0.3.

 

 

https://drive.google.com/file/d/10lK19WZ39mexQxkxfmn7UXemktLRZq2g/view?usp=drivesdk

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