MembersPage/YasecElise (2006-06-03 23:50:35)

The car got an 1.6L 4cyl NA engine because it is believed to better compete in that class, compared to the 1.8L engine.

The deadlines are very tight, it should be ready for race before 2006-03-17

With a standard trigger, it should be no big deal, but this engine has a special trigger.


IAC

Simple bipolar stepper - should be straightforward


Ignition

Wasted spark. Coil on plug style. Yes, only 2 transformers, each have a second high voltage connection for the cyl pair (1-4 and 2-3).


MAP / AlphaN

The engine has a MAP sensor. However, because of very aggressive cams, some loadsites might need to be tuned from TPS (AlphaN).


Trigger - Rover K-series wheel (we refer to it as "elise" trigger)

The engine has camsync, but because of wasted spark, only primary trigger will be used for now.

This crankwheel is very smart construction, because it can sync in half revolution (often even earlier!).

We made some modifications to signalgen to generate the wav sound files to test the trigger setup on the table. Firmware code was tested against this.

Lotus_crank_wheel_36-hell_counted_s.jpg

The trigger is supported from 1.0.38 with the following setting (multitooth, no camsync) MAKE SURE YOU TRY THESE TOO, there is a mismatch right at the very first (primary_trigger=00 is not 01 although it might work with both edges if the sensor is HALL for sure):

Take InputTrigger/TriggerLog to check the tooth pulsetrain correctness. (upload the binary too, and possibly the output after formatted with perl binary.pl < terminal.log > terminal.txt )


A describtion of the trigger (HU; just to confirm the direction and position seen on the image):\n

Mind1, itt küldöm a képet, immáron dedikált lendkerékkel.
A felsõ holtpont fizikailag ott van, ahol a lendkerék tövében a csap van.
(azaz van 6db felfogató csavar + 1 tájoló csap, na a csap van felül
holtponton)
A jeladó ehez képest lejjebb van, gondoltam azt a bordát jelölöm meg, amit
"lát" a szenzor felsõ holtpontban. Komikus mód ez úgy semmilyen rendszerben
nincs semmivel se.
Utána a forgásirány szerint még kettõ bordát "olvas" a szenzor, és kezdõdik
az elsõ kihagyás.


Udv Yas

Azt hittem soha nem fox feliratkozni.:) Lenne 1 kersem:) Ha lehetne akkor kommentalnad magyarul is a torteneseket? Lassan azert tanulok angolul:)

A_Feri/Saybor:)


Here are the configuration files:

[config]

[tables]

InputTrigger/TriggerLog

Seems very nice, signal and polarity is correct. Analysis of the file, missing teeth:

3,13,2,14, ... pattern seems correct for the wheel.

worst case: (note that the log is very-very short read below! There are likely to be worse cases)

The problem is, that the engine stroke kicks the engine at the 169 position, so the crank accelerates (I guess it has a lightweight flywheel).

Therefore the 1318 (*4 usec) difference is followed by 1869 difference, which is LESS THAN 1.5 * 1328. Normally a missing tooth is 2x normal tooth, and the standard code only consides it missing if >1.5 x

We must use multitooth advanced filter (checking toothrel_ ... on GenBoard/UnderDevelopment/FirmwareChanges), and set the treshold, so 1869 / 1318=1.41 is accepted as missing tooth.


Explanation - N,n,M,m are one hexa digit each:

OLD semantics - before 1.0.40

If the tg (time-gap) between 2 teeth compared to tg_prev (previous time-gap)

NEW semantics - since 1.0.41

If the tg (time-gap) between 2 teeth compared to tg_prev (previous time-gap)

As you see, for the missing-tooth condition, original 1.5+m/8 changed to 1.25+m/8 in http://www.vems.hu/files/Firmware/release/v3_firmware_1.0.41.zip

In our case, it's critical than N is 6 or less. Thresholds for different config:

Apparently it's problematic to define a good threshold for this engine. 1.5 was too high by any means, 1.375 didn't work either (we don't know exactly why, it didn't improve from 1.5).

The best is somewhere between 1.16 and 1.41, my vote is to try

If it really doesn't want to work - note: longer triggerlog needed to decide -maybe (but this is hard, requires nontrivial firmware mod)

Also upload the binary triggerlog (before formatting with binary.pl). Use zip if fileyhingy otherwise does not allow upload.

Analysis of new [log2]

With improved binary.pl (see http://www.vems.hu/files/MembersPage/YasecElise/trig2_all.zip ) it's easier to spot MISSINGTOOTH for certain threshold (default 1.5, but any other (like 1.31) can be specified on the command line.

The right side is interesting (left side is rabbish), the 3,13,2,14 pattern is also shown:\nÿ2ÿ

This means that the pattern is recognized with the original 1.5 threshold (without the advanced filter). The * 1.41 that we've seen in the short log is not very typical.

So what's wrong with this setup ?