FreeEMS Status and Capabilities?

FreeEMS topics that aren't specific to hardware development or firmware development.
tlhingan
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FreeEMS Status and Capabilities?

Post by tlhingan »

Hello,
I've been searching for this information for some time and was wondering if someone could give me a quick update.
All the info I find is 1 or 2 years old and most likely out of date.

1. What are the capabilities of this system?
Specifically, what restrictions exist on the types of engines it can run, what parameters are user controllable.

2. What is the electronics hardware that it runs on?
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Fred
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Re: FreeEMS Status and Capabilities?

Post by Fred »

Hello and welcome! :-)
tlhingan wrote:I've been searching for this information for some time and was wondering if someone could give me a quick update.
Sure thing :-)
tlhingan wrote:1. What are the capabilities of this system?
Many and varied, but quite basic, mostly. Best to tell us your application and we can go from there. Things get added on an as-needed-by-someone basis.
tlhingan wrote:Specifically, what restrictions exist on the types of engines it can run
No VVT control yet, direct injection and diesel not likely/difficult, can't run 12 cylinder, runs 8 and 10 in a basic way, runs 6 and lower well. viewtopic.php?f=54&t=1084
tlhingan wrote:what parameters are user controllable.
Everything that's in there is. If not, it's a bug. http://issues.freeems.org/view.php?id=180
tlhingan wrote:2. What is the electronics hardware that it runs on?
Jaguar is your best bet for now: viewforum.php?f=67

Features are going to be on the rise as soon as my daily driver is hardware-complete. Until then it's not worth me tuning it properly. Until it's tuned properly I can't add new features to it as I can't properly evaluate their performance.

Hope that helps.

Fred.
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tlhingan
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Re: FreeEMS Status and Capabilities?

Post by tlhingan »

Thank you for your response!

The schematics make the hardware seem much simpler than I expected.
I don't have a specific target application yet as it will depend on whether or not this project will be funded and undertaken by our R&D team (we love contributing to open-source) or if this will be a personal project.
If it is a personal project, the target application will most likely be my daily driver (B13 Nissan Sentra, 1.6L, auto tranny, fuel-injected, no ABS, OBD 1).
90% of the the vehicle list I've seen on this site are pre-OBD1 vehicles. Is that a system restriction, or is that just what hobbyists and contributors deployed this system to?
Is this system compatible with OBD2?
Our original concept for our in-house project before I stumbled across this site was for a touchscreen user interface that would allow the driver to change between sets of user-defined presets that include tranny shiftpoints, ignition timing, ABS disable, ABS timing, engine maps, seat position and mirror position (just to name a few) and would allow customizing of dashboard sounds and alarms. The idea was to allow the driver to define different sets of presets that suits his or her driving style separately for each of highway, city, high-octane, regular-octane, economy drive, performance drive, etc., and to allow users to even store their own profiles on the unit, allowing multiple drivers of the same vehicle to each have their own presets (that's where seat position and mirror settings come in handy).

Are these things doable with this system?
Is this system an add-on to current ECU's or is it a total replacement?
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Fred
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Re: FreeEMS Status and Capabilities?

Post by Fred »

tlhingan wrote:Thank you for your response!
You're welcome! :-)
The schematics make the hardware seem much simpler than I expected.
That's a core goal of the FreeEMS project, to make the complex fairly simple to understand. It is true, though, that an ECU hardware design is simply a collection of discrete sub circuits in some combination of quantities, bridged together by a handful of interactions and a power and ground network. The latter being the tricky part that people have historically made a dog's breakfast of.
90% of the the vehicle list I've seen on this site are pre-OBD1 vehicles. Is that a system restriction, or is that just what hobbyists and contributors deployed this system to?
Is this system compatible with OBD2?
OBD is an American concept which means little to me. We've run some fairly late model engines, though. The engine doesn't care what electronic emissions interface is attached to it ;-)
Our original concept for our in-house project before I stumbled across this site was for a touchscreen user interface that would allow the driver to change between sets of user-defined presets that include tranny shiftpoints, ignition timing, ABS disable, ABS timing, engine maps, seat position and mirror position (just to name a few) and would allow customizing of dashboard sounds and alarms.
Ignition timing comes within the umbrella "engine maps" however a driver should not be involved in how the engine maps look. There is an optimal set of them and that's the end of that. Only things like DBW control, boost levels, traction control, and the like could benefit from being driver selectable. I'd be very wary of disabling ABS on a car designed for it. The hydraulics are different and it's not the same as not having it in the first place... As for the seat and mirror stuff, this is body control, and although you probably could control it, it makes no sense. The engine is the priority, and for good reason.
The idea was to allow the driver to define different sets of presets that suits his or her driving style separately for each of highway, city, high-octane, regular-octane, economy drive, performance drive, etc.
Octane should be automatic, really. Or consistent, optionally. I rock the second option, but our fuel is reasonably consistent here too, unlike other places.
Are these things doable with this system?
Probably, but I wouldn't recommend mixing body control with engine control, they're distinct and should stay that way.
Is this system an add-on to current ECU's or is it a total replacement?
viewtopic.php?f=54&t=1241 total replacement, known in the industry as a "standalone".

Fred.
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tlhingan
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Re: FreeEMS Status and Capabilities?

Post by tlhingan »

Sorry I haven't been able to continue this conversation, I was on holidays to a country that heavily filters the internets.
It sounds like this system will be a good basis for our project.
We are very much interested in the engine control (as a performance/economy toggle, and some optimizations), but the body controls are also very important to our concept of user experience. The two do not have to be integrated and could very well run on separate hardware, as you suggest, and only share the touchscreen interface. We also have a slew of other bells and whistles we were going to package, 90% of which has nothing to do with the engine.
You are correct that drivers shouldn't be messing with engine maps too much, but I believe there is some optimization to be done in there, not in the fuel-air ratio but in better compensating for intake air temp, moisture and pressure (for example). What I mean is, my daily driver seems more responsive on cool days. There seems to be a weather-related sweet-spot which I am guessing the MAF sensor reads more accurately at. Also, I am geographically located at over 1 km of altitude, and I'd like to think there is some further optimization to be done on the sensor readings. One selling feature of the system we have in mind is, since we have total control of the programming, to allow the swapping of sensors, injectors and such, or at the very least allowing the calibration of the sensors to provide optimum engine performance.
Our R&D team is funded from government grants, and we generally favour open-source software and hardware, not only so that we don't start projects from scratch, but also so the project already has buy-in from end-users and/or manufacturers, and also so other people could add to our work after we are done. We usually focus on proof-of-concept and alpha-prototype deliverables, so I think we would not only greatly benefit from the platform you have already developed, I think we can greatly contribute to it.
I'll pass this information along to the team shortly, I am excited at the prospect of this system.
Just so you know, the initial scope called for 2 or 3 different vehicles, so we will pick something that is not on the list already.
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Re: FreeEMS Status and Capabilities?

Post by sim »

tlhingan wrote:Sorry I haven't been able to continue this conversation, I was on holidays to a country that heavily filters the internets.
It sounds like this system will be a good basis for our project.
We are very much interested in the engine control (as a performance/economy toggle, and some optimizations), but the body controls are also very important to our concept of user experience. The two do not have to be integrated and could very well run on separate hardware, as you suggest, and only share the touchscreen interface. We also have a slew of other bells and whistles we were going to package, 90% of which has nothing to do with the engine.
You are correct that drivers shouldn't be messing with engine maps too much, but I believe there is some optimization to be done in there, not in the fuel-air ratio but in better compensating for intake air temp, moisture and pressure (for example). What I mean is, my daily driver seems more responsive on cool days. There seems to be a weather-related sweet-spot which I am guessing the MAF sensor reads more accurately at. Also, I am geographically located at over 1 km of altitude, and I'd like to think there is some further optimization to be done on the sensor readings. One selling feature of the system we have in mind is, since we have total control of the programming, to allow the swapping of sensors, injectors and such, or at the very least allowing the calibration of the sensors to provide optimum engine performance.
Our R&D team is funded from government grants, and we generally favour open-source software and hardware, not only so that we don't start projects from scratch, but also so the project already has buy-in from end-users and/or manufacturers, and also so other people could add to our work after we are done. We usually focus on proof-of-concept and alpha-prototype deliverables, so I think we would not only greatly benefit from the platform you have already developed, I think we can greatly contribute to it.
I'll pass this information along to the team shortly, I am excited at the prospect of this system.
Just so you know, the initial scope called for 2 or 3 different vehicles, so we will pick something that is not on the list already.
It is not surprising that your car feels more responsive on cool
days. This is not likely due to sensor calibration though, it is
because cool air is denser, and the engine can injest more of it,
all other things being equal, and make more power.

Similarly, there is not much point to two sets of maps, one for
performance and one for economy. The better the tune is, the
closer the timing and fueling are to ideal; the more power the
engine will make for a given input of fuel. When you get the map
right, it will be right for economy and performance at the same
time.

With FreeEMS, it is possible to get very accurate calibrations of
the sensors, especially if you put some time into measuring them.
The complete ability to read and modify the code is also an
amazing advantage, no matter what the project goals.
<@TekniQue> but in the end, it's code that makes a computer useful
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Fred
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Re: FreeEMS Status and Capabilities?

Post by Fred »

sim wrote:It is not surprising that your car feels more responsive on cool
days. This is not likely due to sensor calibration though, it is
because cool air is denser, and the engine can injest more of it,
all other things being equal, and make more power.
Yep, this is why. Also cold air means more possible timing and more efficiency from the engine, especially if it's higher compression.
sim wrote:Similarly, there is not much point to two sets of maps, one for
performance and one for economy. The better the tune is, the
closer the timing and fueling are to ideal; the more power the
engine will make for a given input of fuel. When you get the map
right, it will be right for economy and performance at the same
time.
Not quite true, but true for all intents and purposes. There are two optimal tunes. In summary: most of the time you want the efficient one, and only at WOT do you ever want the powerful one. The trick comes in finding the blend point/range. This is the only area where choosing could have a benefit. Hence power buttons in old cars. Other cars use WOT switches to determine your desire and hunger for torque. Modern stuff likely has a heuristic, or possibly ignores your desires in favour of emissions. viewtopic.php?f=8&t=1768
sim wrote:With FreeEMS, it is possible to get very accurate calibrations of
the sensors, especially if you put some time into measuring them.
Time very well spent, too.
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Re: FreeEMS Status and Capabilities?

Post by DonTZ125 »

You seem to be arguing both sides of the question ... ;)

My thought is that for most part-throttle conditions the difference between 'max achievable power' and 'power achievable at max economy' really isn't that much. For street or track, the ability to roll on smoothly at any rate from any position is far more important than raw power.
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Re: FreeEMS Status and Capabilities?

Post by Fred »

Yes, you're exactly right. So then it's just down to obtaining these two tunes (the hard part), and a strategy to move between them. Assuming that you can obtain them (most can't even come close), the most naive strategy of a manual blend near WOT or into boost leaves very little room for further gains. Which I guess is my point. The other part of my point was that this can be automatic in various ways so the driver need not be involved.

With respect to part-throttle torque, even if it's less it doesn't matter, you just roll on a little more. Only once you reach WOT and can't add more, is it important to have the last little bit, thus it should already be applied by the time you get there.
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Re: FreeEMS Status and Capabilities?

Post by Hentai »

What I had found a lot of times on certain cars it will be usually TPS and\or MAP based as well Time factored in there.
The oem strategies have a lot in there to control this operation.

on a chevy cruz 1.4 turbo, I could be at full boost as low as 1500 revs and as long as I was under 70% throttle absolute it would still command stoich, once I got past that it would drop down to 11s
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