c1d4.wfm is an interesting file - two ion channels with two combustion detection channels but why is it so small? Was it intentional or is this an error?
i14.wfm is the other file where we have ion and combustion detection and again it's very small
Did you record the knock signal at all?
Thank you for the Dec 16 batch, please make another one with waves combining trigger signal with ion sense signal and combustion detection, also trigger signal with ion sense and knock sense channel.
Re: Ion Sense
Posted: Sun Dec 23, 2018 7:25 pm
by AndreyB
Re: Ion Sense
Posted: Sun Dec 23, 2018 10:10 pm
by AndreyB
AC coupling on ion sense signal, longer timeframes and better x-window
Re: Ion Sense
Posted: Sun Dec 23, 2018 10:27 pm
by andreika
ion_signal_match.jpg (73.35 KiB) Viewed 27423 times
Per the below, a 1mS to 2mS spark duration is normal. It looks like this spark is about 2mS at idle, which might be a bit high. It also appears we are seeing detonation pressures, as we occasionally see the combustion indicator trigger 2X in one combustion. This engine may have some problems, which are great to look at. This engine may be showing us thing the original engineers didn't get to see. http://crypton.co.za/Tto%20know/Ignition/burn%20time.html
The videos above are Saab - I think there is no point adding diesel into Saab's fuel tank since stock ECU would adjust too quickly. I plan to put diesel into red Miata running under rusEfi control hopefully this weekend.
Also looks like CDM is affecting the ion sense signal. Jared, can you get the schematics of CDM in terms of how is it affecting ion signal?
Re: Ion Sense
Posted: Wed Dec 26, 2018 11:02 am
by kb1gtt
I can try to schematic-ize the CDM for this signal. That was the yellow wire correct?
Also FYI, it's long hours for me at work until the end of the year. I'll try to get it in before the weekend, but I'm most likely to attempt it during the weekend.
Pieces joined together using https://www.openshot.org/ - this looks like nice softwar but video rotate did not work
Re: Ion Sense
Posted: Sun Dec 30, 2018 11:14 am
by kb1gtt
Do you have a snippet with the OEM pull up what ever that is? Perhaps just a series of pictures, OEM, no pullup, 1k ohm, etc. Pictures can be easier to look at then pausing the video. The video is great as it shows lots of great stuff relative to time, but when comparing the differences, it's nice to jump from one to the other very rapidly with the eyes.
Do you have a snippet with the OEM pull up what ever that is? Perhaps just a series of pictures, OEM, no pullup, 1k ohm, etc. Pictures can be easier to look at then pausing the video. The video is great as it shows lots of great stuff relative to time, but when comparing the differences, it's nice to jump from one to the other very rapidly with the eyes.
Audio says and video shows OEM module is connected in the beginning. Without audio narration it would be impossible for me to know which picture shows which conditions, hopefully there are options to work with the video. Maybe leave comments right on youtube with timestamps regions for each pull-up.
Re: Ion Sense
Posted: Tue Jan 01, 2019 1:24 am
by theflyingdutchp
Russian, can you connect a scope channel for the knock detection output signal of the CDM module? Also, I may have missed it, but what is the blue trace? Correct me if I'm wrong but its still wired as: red ignition demand #1 (CDM -> coil), green combustion detection #1 (CDM -> ECU), and yellow coil-feedback #1 (coil -> CDM).
Also, maybe for inducing knock you can purposefully tune the engine badly by reflashing the Trionic ECU? Obviously not for too long, but it might be nice to see what a good solid knock response looks like.
It may also be useful to log data from the SAAB ECU (such as ignition advance & knock count) once you get logging from the oscilloscope going. Perhaps you could tap another, user-controlled, system on each datastream to establish a common time reference IE: turning on the headlights, cranking the starter, etc.
Hallo.
I found this side by seachring "ion sensing" films on youtube.
Verry interesting. Thank you for your videos.
I have uploaded the CDM/COP wireing from Opel engine Z20NET. (same Trionic 8 that SAAB use) There is old analog and new digtial CDM wiring. The only difference i see, is the color of the ion sensing feedback cable (coil->CDM) of coil 2+3.
You listed up which cars are use ion sensing. There is also a Mecerdes Benz V12 engine. M137 - producend since 1998.
Have you seen this funny guy at youtube?
(he has a couple of ion sensing videos)
He build a closed loop basend on ion sensing. He can autotune the igniton timing to hit the optimal peak preassure point. For his rotary engine 52° after top dead center. I have read in the saab papers, that the optimal peak preassure point for pistion engines are at 10-15°.
Is in the combustion signal (CDM->ECU) the peak preassure point included and visible?
Has the saab a autotune to reach optimal peak preasure point?
(like the youtube guy)
I've seen one of his videos but that's a good point that I should poke him. Just left a couple of comments on his videos
At the moment the ion project is a bit on hold, need to spend some time on other projects but definitely planning to get back into this in a few months!
Re: Ion Sense
Posted: Tue Feb 12, 2019 7:08 pm
by kenzone
@russian May I ask whether you managed to test the fitment of the Demio COPs on the miata valve cover?
Also what are the chances the Demio COPs' outputs play nice with the Saab CDM?
Another youtube user who appears to have implemented Ion Sensing successfully is Nathan Coleman.
Their more recent video showcases a filtered clean pressure signal.
Notes from most recent video:
"Modified Ion testing circuit, passing the full wave signal limited to +/-5V. Full wave allows the low pass filter to kill the ignition noise to zero with no DC offset, as you can see when I adjust the filter it disappears entirely. The ion current flow is positive, spark current is negative. Bias voltage is now 180V, up from 90V, seeing a maximum of 300uA ion current, fluctuating between 50-100 at idle. In the video I'm adjusting the sensing resistor to give the strongest signal without hitting the 5V limit. Spark current peaks at approx 70mA. I thought it would be more, good news as now I don't need as many zener diodes to dissipate the energy. Will probably use 3x50V 5W instead of 12x15V 5W. Almost ready to finish the processing circuit to collect the peak current per cycle to feed into the ecu for datalogging."
@russian May I ask whether you managed to test the fitment of the Demio COPs on the miata valve cover?
Also what are the chances the Demio COPs' outputs play nice with the Saab CDM?
Lack of time and priority for this is the only reason why I have not tried I would say very little chance of me trying this in February or March, some chance in April+.
Another youtube user who appears to have implemented Ion Sensing successfully is Nathan Coleman.
Their more recent video showcases a filtered clean pressure signal.
Thank you for the link! Just poked asking for updates
There is written:
"Empirical studies [7], under steady stateconditions in a dynamometer, indicate that this isapproximately true but that the model has difficultiesdescribing low load phenomena, even if data is collectedunder ideal external conditions and then averaged. Thiscomplication is due to the fact that the post flame peakessentially vanishes if the load is less than 20% MBT2(see Fig. 3). It is worth mentioning, in this context, thatnormal driving on the highway is close to the low loadsituation."
"An ion current signal sampled during a single cycle on boardthe SAAB car while driving on the highway (solid line). The enginespeed was 1500 RPM and the load was approximately 25% of MBT.There are several wide peaks in the signal and the post flame phase isnot visible. The pressure trace is shown for comparison (dashed line)."
i think this the reason why you cant see peak preassure point in the oszilloskop videos.
To low load in idle and rev up while car is standing still.
Re: Ion Sense
Posted: Tue Apr 23, 2019 3:20 am
by AndreyB
Bosch (7330) F5KE0 Industrial Combustion Sensor $8.75 & FREE Shipping on Amazon for Measures Ionic current to determine combustion efficiency "CATERPILLAR CAT 3600 SERIES" - they use ion sensing in large diesels natural gas engines?
So far we have not mentioned the fact that Mercedes S600 v12 m275 engine has 24 coils with Ionic current sensing. Yes, 24 - they had two coils per cylinder. 2751500780 integrated coil pack for 6 cylinders costs about $600-$1200
You can pick up these ion sense coils from Harley for about $40 or OEM for about $65 Mine is marked Delphi 28058097 with a serial number of aE141028 48
I could reasonably easily have soldered wires to the connector, then filled it in with hot glue. I didn't do that and got a bunch of arcing in the connector. I didn't notice it until it was toasted. See attached schematic that I created for it.
From the ohms meter, I find this coil is just 2 coils, it did not appear to have the diodes, but it would have the coils in such a way that you can obtain the ion signal.
I know it has been a while, but did you ever get an ion sense signal out of the Harley coil before frying it?
Do you happen to know what the voltage range of the ion sense pin is: 0-5v, 0-12v, something else entirely?
Re: Ion Sense
Posted: Fri Dec 27, 2019 10:43 pm
by AndreyB
At the moment all our ion sense success is with latest generation Saab 9-3 COPs. @andreika is looking at raw signal from the coil with Kinetis MCU and I am being lazy with Saab CDM. Very slow progress because progress is slow
