silentbob
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« Reply #30 on: June 03, 2011, 12:44:18 AM »
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I need a little help with understanding the schematic. What is the circle with the plus or minus next to it? Also, what is the asterisk in the box? These aren't explained in the beginning. I have included my general understanding below.
The output from KFZW is input into the partial function ZW_NWS as zw_local.
The circle is just a summation point and the asterisk is the sign for a multiplication. Simple as that 
fnwue = 1 is the maximum possible overlap of the inlet camshaft and determines whether KFZW or KFZW2 is used in ZW_NWS. I have not completely figured out the origin of fnwue, but I didn't see any relation to KFNW.
If SY_NWS = 0, then zwnws = zw_local (does not apply).
If SY_NWS = 1 and fnwue < 1, then zwnws = zw_local?
If SY_NWS = 1 and fnwue = 1, then zwnws = the output from KFZW2?
If SY_NWS = 2, then zwnws = the output from DZWNWSUE (does not qpply)?
zwnws is effected by KFDZWKG, dzwoag, and dzwol (I believe all = 0) and is the output as zwgru - Basic ignition
fnwue is calculated in NWWUE. It's zero if the cam is in the basic position and 1 if it's max shifted. So what you see in the shematic is how the interpolation during the shifting process works. |
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« Last Edit: June 03, 2011, 01:06:56 AM by silentbob »
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phila_dot
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« Reply #31 on: June 03, 2011, 07:58:21 AM »
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Thank you for the reply silentbob. I apologize for not being clear in my post. I need a little help with understanding the schematic. What is the circle with the plus or minus next to it? Also, what is the asterisk in the box? These aren't explained in the beginning. I have included my general understanding below.
The output from KFZW is input into the partial function ZW_NWS as zw_local.
The circle is just a summation point and the asterisk is the sign for a multiplication. Simple as that How does the - circle + or + circle + effect the data and flow? I assumed the asterisk in the box was multiplication, but in the beginning it is defined as a box with an x.
fnwue = 1 is the maximum possible overlap of the inlet camshaft and determines whether KFZW or KFZW2 is used in ZW_NWS. I have not completely figured out the origin of fnwue, but I didn't see any relation to KFNW.
If SY_NWS = 0, then zwnws = zw_local (does not apply).
If SY_NWS = 1 and fnwue < 1, then zwnws = zw_local?
If SY_NWS = 1 and fnwue = 1, then zwnws = the output from KFZW2?
If SY_NWS = 2, then zwnws = the output from DZWNWSUE (does not qpply)?
zwnws is effected by KFDZWKG, dzwoag, and dzwol (I believe all = 0) and is the output as zwgru - Basic ignition
fnwue is calculated in NWWUE. It's zero if the cam is in the basic position and 1 if it's max shifted. So what you see in the shematic is how the interpolation during the shifting process works. I can see where fnwue is created, however, I have not yet worked out how it is set. If camshaft control is simply on/off, then why is there a need for interpolation. I just want to make sure that I have a complete understanding and I do not like to assume things. Thank you for your patience. |
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silentbob
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« Reply #32 on: June 03, 2011, 09:50:20 AM »
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How does the - circle + or + circle + effect the data and flow? I assumed the asterisk in the box was multiplication, but in the beginning it is defined as a box with an x.
It's just a summation (+1) + (-fnwue) for example.
I can see where fnwue is created, however, I have not yet worked out how it is set. If camshaft control is simply on/off, then why is there a need for interpolation.
I just want to make sure that I have a complete understanding and I do not like to assume things. Thank you for your patience.
The interpolation is only for the situation when the cam is shifted to the other position. Example: Cam is in it's normal position (fnwue=0 -> zwnsw = zw_local * (1-0) + KFZW2*0=zw_local) Cam half of the way to the end position (fnwue=0,5 -> zwnsw = zw_local (1-0,5) + KFZW2 * 0,5) Cam in end position (fnwue=1 -> zwnsw = zw_local* (1-1) + KFZW2 *1= KFZW2) |
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s5fourdoor
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« Reply #33 on: June 03, 2011, 10:19:44 AM »
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It seems to me that KFNW is fnwue. Thats my guess...
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nyet
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« Reply #34 on: June 03, 2011, 12:09:48 PM »
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I'm still confused. Like phila_dot says, the 2.7t cams are in one of only two positions.
its either a*0 + b*1 or a*1 + b*0
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silentbob
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« Reply #35 on: June 03, 2011, 12:34:16 PM »
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During the switching process it's not (thought it's only a short amount of time).
The engine has a cam sensor on each bank. The ECU knows exactly were the cam is. It's not just 0->1
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s5fourdoor
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« Reply #36 on: June 03, 2011, 02:13:27 PM »
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Perhaps its the zero-one thresholding which is a basic algebraic technique. If you have two states, you can create an arbitrary combination of values between the two state values, by using a sliding amount of weight place on each state.
so: A * state_1 + B * state_0 given that: A + B = 1 and A > 0 and B > 0
Another basic way of saying this is that values are being Blended. I would guess the "blending" is being handled by the KNFW table, possibly with the RPM as some input. Thats my guess anyways...
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phila_dot
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« Reply #37 on: June 03, 2011, 11:06:44 PM »
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It seems to me that KFNW is fnwue. Thats my guess...
KFNWSE does in fact become fnwue after going through NWSOLLE, BGARNW, GGNW, and NWWUE. There are alot of influences along the way. However, the source for KLFNWE is fnwue. I have not been able to locate this characteristic though. |
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Rick
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« Reply #38 on: June 04, 2011, 04:13:08 AM »
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The interpolation is used when the cam is switching.
Although it can only be controlled between 2 positions, when it changes state from one position to another, it takes a finite amount of time for this to happen. During this time, it will not be at either position, but somewhere in between and so the ignition angle is calculated for this point.
Rick
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vwaudiguy
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« Reply #39 on: June 04, 2011, 10:37:02 AM »
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How long does this transition take? I assume it would be expressed in engine cycles? Does oil pressure have any effect (ie. lower rpm transition takes longer) Or I guess the transition always takes place at the same rpm/coolant temp? This transition is primarily for emmisions? Sorry for 20 ?'s  |
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"If you have a chinese turbo, that you are worried is going to blow up when you floor it, then LOL."
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setzi62
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« Reply #40 on: June 13, 2011, 01:49:54 AM »
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How long does this transition take? I assume it would be expressed in engine cycles?
I monitored camshaft switchover and for the monitored car (150PS 1.8T) it takes roughly 120ms for the changeover, see attached image. |
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phila_dot
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« Reply #41 on: June 14, 2011, 10:54:24 AM »
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I have worked out KFNW's "influence" on zwgru in the spreadsheet that I use. I will post it when I get the chance.
Setzi, have you compared the fnwue values that you logged vs KFNW? I have not gotten the chance to work out everything between KFNW and fnwue yet. If you can post the log I would like to compare it to my theoretical values.
Edit: Tuning KFZW and KFZW2 based off of my integrated KFNW values has worked as desired.
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« Last Edit: June 14, 2011, 10:59:10 AM by phila_dot »
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s5fourdoor
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« Reply #42 on: June 14, 2011, 11:13:29 AM »
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I have worked out KFNW's "influence" on zwgru in the spreadsheet that I use. I will post it when I get the chance.
Setzi, have you compared the fnwue values that you logged vs KFNW? I have not gotten the chance to work out everything between KFNW and fnwue yet. If you can post the log I would like to compare it to my theoretical values.
Edit: Tuning KFZW and KFZW2 based off of my integrated KFNW values has worked as desired.
boss! its amazing to watch this unravel. |
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setzi62
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« Reply #43 on: June 16, 2011, 03:32:52 AM »
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I have worked out KFNW's "influence" on zwgru in the spreadsheet that I use. I will post it when I get the chance.
Setzi, have you compared the fnwue values that you logged vs KFNW? I have not gotten the chance to work out everything between KFNW and fnwue yet. If you can post the log I would like to compare it to my theoretical values.
Here are the logs. In this case I logged only small number of other values, don't know if this would reveal something. I did not yet look at the contents of the related maps (KFNWSE, FNWTME, ...) to understand at which conditions the camshaft change should take place. |
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playgoods
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« Reply #44 on: June 16, 2011, 01:14:01 PM »
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Sorry if I am off topic here. I am reading and seeing all the codes KFNW, KFZWOP ect.
I take it these are names of maps. Are these locations or what exactly are the meanings?
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