raw data for misfire detection based on crank timing

[AndreyB]

2003 miata. I know that stock OEM can detect misfire in specific cylinder with just that four tooth crank trigger wheel.

in https://github.com/rusefi/rusefi_documentation/tree/master/OEM-Docs/Mazda/2003_Miata/digital-recordings folder we now have crank/cam data from logic analyzer, would anyone be interested to run whatever processing magic and see what could be extracted?

.sal is file extension of Saleae v2
.csv is plain text export of same

nb2-happy-warmup-idle: good spark plugs, everything good

nb2-idle-without-injector-2: same good spark plugs but injector #2 disable in software

nb2-suspected-bad-sparkplug-1: injector #2 re-enabled but now spark plug #1 is suspected bad

nb2-sparkplug-1-completely-removed-zero-compression-in-1: now spark plug #1 is removed and injector #1 disabled in software

This is all part of the https://github.com/rusefi/rusefi/issues/936 dream

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[puff]

Снимок экрана 2021-07-19 в 18.17.42.png (26.29 KiB) Viewed 3680 times

it's 10.82ms. (previous 'tooth' was 6.80). next cylinders:
6.74-10.75
6.67-10.63
6.62-10.75 and then again the one with disconnected injector:
6.79-10.83
on average, for a larger tooth the difference is somewhat 100µs?
i'm wondering how it would behave under load or in other engines (with 5,6 8 cylinders? with a heavier flywheel?)
I was just thinking of building something similar – a standalone gadget capturing pulses from Hall sensor, with an array (a ring buffer(?)), to get an average timing for each cylinder.

[AndreyB]

ArtemB has done some initial processing see visualization at https://github.com/rusefi/rusefi_documentation/tree/master/OEM-Docs/Mazda/2003_Miata/digital-recordings/Artem-processing

[AndreyB]

good revving and revving with artificial misfire data added

[AndreyB]

We have a python prototype using https://en.wikipedia.org/wiki/Savitzky%E2%80%93Golay_filter at https://github.com/rusefi/rusefi_documentation/tree/master/OEM-Docs/Mazda/2003_Miata/digital-recordings/Artem-processing2

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[AndreyB]

https://github.com/rusefi/rusefi_documentation/blob/master/OEM-Docs/Mazda/2003_Miata/digital-recordings/Artem-processing2/sig.py leverages https://numpy.org/ which has a C++ implementation https://github.com/dpilger26/NumCpp