Hi Paul, Sorry if I confused you, the Catalytic Converter is indeed a passive device in the sense that it is not controlled by electrical signals, however it has properties that are controlled by the vehicle's ECU sending alternating leaner and richer exhaust mixture and maintaining operational temperature of the Cat, to utilize its ability to combine (burn) stored Oxygen and (rich) exhaust gas. I won't go into the reason that exhaust is alternating between lean and rich deliberately (to reduce unwanted elements forming) but the fact that the Cat is part of the feedback loop of the ECM, controlling the exhaust gases to be alternating rich and lean by injecting an appropriate amount of fuel for the amount of air for the current engine RPM that is controlled by the throttle butterfly and metered by the MAF/MAP sensor and to verify that the mixture is correct by measuring the exhaust with the signals from the Oxygen sensors upstream and downstream of the Cat, that is a bit of a challenge to simulate in software in a controller to keep the ECM happy without ICE connected to it... I had to learn all this operation of the ICE when my Prius was failing its self-tests (even though it was still driving great) due to the upstream Oxygen sensor having a flaky heater. And I wanted to fix it myself instead of shelling out for a mechanic or selling it as "does not pass smog".
I suggest you get some wiring diagrams of some popular vehicles that you want to simulate the "engine" of and trace all the signals in and out of the ECM to their sensors/actuators and then see if you need to add some standard analog interfaces (input and output that can handle 12V signals) and choose a controller that has enough analog I/O with A/D and D/A converters or add external (serial bus) controlled interface chips so you can also expand the system if you need more signals. Note that I suggest to build a complete analog and digital (on/off signals) engine replacement simulator and *not* include CAN bus or try to simulate a computer of the car, because as soon as you do that, you are locked into a specific brand or even model of car. Also the ECM is typically the computer that is "coded" to one or two other computers in the car. In the Nissan Leaf you need the combination of LBC, BCM, VCM and smart key to make a Leaf work. LBC = battery computer (BMS) probably included to avoid battery stealing, BCM = Body Control Module, VCM = Vehicle Control Module which is essentially the ECM without engine. So, avoiding to get into the endless search of the correct CAN bus codes, you should be able to simulate analog signals from sensors and provide a simulation of (part of) the engine. I have the suspicion that hot rodders also use such simulators as many modified vehicles no longer have all the sensors (or even the Catalytic Converter) so they need to do something to keep the car working. Success! Cor van de Water Chief Scientist Proxim Wireless office +1 408 383 7626 Skype: cor_van_de_water XoIP +31 87 784 1130 private: cvandewater.info http://www.proxim.com This email message (including any attachments) contains confidential and proprietary information of Proxim Wireless Corporation. If you received this message in error, please delete it and notify the sender. Any unauthorized use, disclosure, distribution, or copying of any part of this message is prohibited. -----Original Message----- From: paul dove [mailto:dov...@bellsouth.net] Sent: Tuesday, January 03, 2017 4:08 AM To: Cor van de Water; Electric Vehicle Discussion List Subject: Re: [EVDL] Recent Model EV Conversion - CAN and accesories to work.. Cor, that was a goo summary but you make a catalytic converter sound like an active device based on feedback. I am not sure what you mean because a catalytic converter is a passive device that converters the gas as it passes through. There are no controls. Sent from my iPhone > On Jan 3, 2017, at 4:02 AM, Cor van de Water via EV <ev@lists.evdl.org> wrote: > > Marco, > Every car is a little different, so you are wise to use a controller > that you can program to simulate signals from a recent car's engine, > whether 3, 4, 5, 6 or 8 cylinder (there are 10 and 12 cylinder cars, not > many though) > Modern sparkplugs are driven individually with an ignition coil that > gets a pulse from the ECM and gives feedback whether a spark was > detected. > Regarding injectors - the ones I have seen have no feedback and are > simply 2-wire with a pulse to open, no error is generated if one is > unplugged. But they are in the feedback loop for lean/rich mixture so > you will need to use the pulses to control the Oxygen sensor feedback. > MAP/MAF is slightly tricky since it is also in the feedback loop. > Throttle control: ECM driving the throttle opening motor, I have never > tried to unplug it to see if there is an error. > Oxygen sensor: most are heated and the ECM will measure and report an > error if the sensor is not drawing the heater current (failed open). > The oxygen sensor output of the upstream sensor(s) *must* vary from lean > to rich with the modulation of the injectors. > Downstream oxygen sensor(s) typically generate a continuous (non > varying) signal because the Catalytic Converter stores/releases oxygen > for complete combustion, in the rhythm of the lean/rich modulation of > the injectors, except that occasionally the car's diagnostics will try > to determine how well the Cat still stores oxygen by deliberately > running rich and measuring how long it takes for the downstream oxygen > sensor(s) to detect that the Cat is no longer emitting complete > combusted products. > Then there are knock sensors, timing sensors, vacuum, temperature and so > on. > Don't forget the valves and sensors that measure if the fuel tank is > sealed, valves that purge early (cold, rich) exhaust as re-circulation > through the engine again and all kinds of other emissions reduction > tricks. > The fuel tank level sender, sometimes pressure sensors for example for > oil pressure, oil temperature sensor(s), (automatic) gearbox control > signals and feedback, speed sensor on the gearbox output RPM, and so on. > It better be configurable because there are a lot of differences between > different cars. Some cars have a hot coolant storage thermos bottle that > has a pump and 3-way valves. > More and more cars are (mild) Hybrids that have electric motors, > controller and battery - not sure that you want to simulate all that... > Best is to get a hold of the service docs of a couple cars and figure > out what is involved in their engine and how to keep the ECM happy. > Success! > > Cor van de Water > Chief Scientist > Proxim Wireless > > office +1 408 383 7626 Skype: cor_van_de_water > XoIP +31 87 784 1130 private: cvandewater.info > > http://www.proxim.com > > This email message (including any attachments) contains confidential and > proprietary information of Proxim Wireless Corporation. If you received > this message in error, please delete it and notify the sender. Any > unauthorized use, disclosure, distribution, or copying of any part of > this message is prohibited. > > > -----Original Message----- > From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of Marco Gaxiola > via EV > Sent: Tuesday, January 03, 2017 12:03 AM > To: Electric Vehicle Discussion List > Subject: [EVDL] Recent Model EV Conversion - CAN and accesories to > work.. > > I'm in the middle of a 2013 EV conversion project (well is not a very > recent), but as some of you may know; newer vehicles comes with more and > more electronics that operation of some devices and features of the > vehicle > relies on the ICE data and information being generated by the ECM (OEM > computer) thru the CAN Bus. > > When you convert a vehicle like this, you face some problems by the > abscence of the running engine such: > - non electric powered steering. > - non operation of the AC unit (assuming the AC compressor and > everything > is there like original). > - non working turn signals.(some models with digital turn signals) > - missing gauges on the instrument cluster like RPMs, speedometer, etc. > plus a bunch of red and amber known warning lights on. (and of course a > lot > of DTC codes when reading the OBD port) > - etc... > > I tryed to find other threads about this subject but did not find any, > at > least not recently. So I decided to post this one, hope that someone has > already face this problem and become able to fully convert newer models > without affect most OEM features from the vehicle. > > If someone has done this, please share your experience. But if not, let > me > explain my thoughs and share your comments/feedback of what you think or > suggest me to do: > > - My first idea is to design a small PCB with a micro on it, that would > simulate most ot the analog and digital signals that the ECM needs from > all > the sensors on the gas engine to keep it running like the water > temperature > sensor, oil pressure, cranckshaft sensor, oxigen and manifold sensors > (MAF > and MAP), etc. My theory is that this could be a simple way (since most > sensors are analog 0-12V, 0-5V of On/off outputs) that are not so > complex > to emulate, and doing this way; the ECM would believe the ICE is there > running all fine and perfectly. > > Of course, the algorithm and maybe some of the simulated PCB outputs > would have to be changed on every different model of vehicle. (every > manufacturer uses many different sensors). But it would be a nice device > if > same vehicle is beeing converted, like in a fleet project. > > - The second thing, would be to go on a higher leve of > microcomputer-microcontroller design that would allow to talk to many of > other units on the vehicle thru the CAN bus, trying to replace those > specific commands and data generated by the ICE, needed by those devices > to > correctly operate, Such RPM and speed for the electric power steering as > example. > > The challenge here would be that, like the one before; every model and > vehicle brand, has propietary CAN communication protocols that would be > a > monumental job to reverse engineer and interpret those codes, isn't it? > > > I'm not so familiar with automotive CAN procols altough I undestand CAN > bus > at the communication/physical level. > > Any thougths or suggestions? > > > Marco Gaxiola > EnergyEV.com > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: > <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20170103/4914 > d072/attachment.htm> > _______________________________________________ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > http://lists.evdl.org/listinfo.cgi/ev-evdl.org > Read EVAngel's EV News at http://evdl.org/evln/ > Please discuss EV drag racing at NEDRA > (http://groups.yahoo.com/group/NEDRA) > > _______________________________________________ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > http://lists.evdl.org/listinfo.cgi/ev-evdl.org > Read EVAngel's EV News at http://evdl.org/evln/ > Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA) > _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org Read EVAngel's EV News at http://evdl.org/evln/ Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
