[enviroCar-discuss] Adding a new car and few other questions

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[enviroCar-discuss] Adding a new car and few other questions

Landswellsong
Hello,
When I first read about your project I was very thrilled since it's something I always thought of implementing and I must say your implementation of the idea is totally great. Since it's open-sourced, I thought I wanted to contribute a bit. My car is a Renault Kangoo dCi diesel and I wanted to write the diesel consumption support. Therefore I have a few questions to ask:

1) Is there a way to add the car to the car list? As far as I've understood, the car list is fetched from JSON or something and there's no way the userspace Android app may redefine it. Is it right? If so, how do I add a car?

2) From what I read in the relevant literature, the viable way to estimate ECU-controlled injection diesels is by analyzing 0x01 0x04 Engine Load PID. For the diesels, this value should be proportinal to the relation between the current fuel flow rate and the reference maximum fuel flow rate. The only problem, that this value is unitless and in order to produce real data one must calibrate their car. The usual recipe for that is to estimate the consumption between 2 full tank fuelings and thus devise the proportinality coefficent given the distance and average speed and rpm. I thought of a more accurate alternative if we could make the user fill the tank and run the enviroCar every time the engine is running until the next fueling with it systematically recording the engine load values. After that, the "area under curve" for the plot of the values recorded should be proportional to the fuel consumed and thus we can get the relation. Is it for me ok to add such a functionality to the program, I mean the engine-load based consumption calculator and 2 ways of estimating the proportionality coefficient.

3) In theory, there's a set of nonstandard PIDs for Renaults that I can use to obtain instand fuel consumption per stroke. I'm still struggling with obtaining this data via a simple python script, but there are success reports on the web. Ideally, it may be an even more accurate measure of consumption or at least one can use this data to estimate the relation between the engine load and consumption without having user to actually fill the car. But I'm not a law expert and I'm unsure if it's ok to publicaly use nonstandart PIDs in an opensource app. Could anybody comment?

Kind regards,
-- 
Oleksiy Protas
National University «Kyiv-Mohyla Academy»

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Re: Adding a new car and few other questions

MatthesRieke
Hi Oleksiy,

welcome to the enviroCar community! Your will for contributions is highly appreciated. Find some answers and opinions to your questions inline.

Best regards,
Matthes


2014/1/9 Oleksiy Protas <[hidden email]>
Hello,
When I first read about your project I was very thrilled since it's something I always thought of implementing and I must say your implementation of the idea is totally great. Since it's open-sourced, I thought I wanted to contribute a bit. My car is a Renault Kangoo dCi diesel and I wanted to write the diesel consumption support. Therefore I have a few questions to ask:

1) Is there a way to add the car to the car list? As far as I've understood, the car list is fetched from JSON or something and there's no way the userspace Android app may redefine it. Is it right? If so, how do I add a car?

Yes, you are able to add a new car from the App. Based on your feedback, I have the feeling that it is a bit hidden :-) From the menu bar on the left, go to "Settings". The very last entry is for configuring the car. It opens a new view with two sections (you might have to scroll, depending on your device's display size). The section "New car profile" allows the definition of the required parameters. After filling these in, tap "Register Car" (you need to be logged in).
 

2) From what I read in the relevant literature, the viable way to estimate ECU-controlled injection diesels is by analyzing 0x01 0x04 Engine Load PID. For the diesels, this value should be proportinal to the relation between the current fuel flow rate and the reference maximum fuel flow rate. The only problem, that this value is unitless and in order to produce real data one must calibrate their car. The usual recipe for that is to estimate the consumption between 2 full tank fuelings and thus devise the proportinality coefficent given the distance and average speed and rpm. I thought of a more accurate alternative if we could make the user fill the tank and run the enviroCar every time the engine is running until the next fueling with it systematically recording the engine load values. After that, the "area under curve" for the plot of the values recorded should be proportional to the fuel consumed and thus we can get the relation. Is it for me ok to add such a functionality to the program, I mean the engine-load based consumption calculator and 2 ways of estimating the proportionality coefficient.

Of course you are very welcome to add functionality. Thats one reason why we're all into open source software :-) Your approach sounds very interesting and also promising. We have not digged too much into alternative or advanced formula for calculating diesel consumption. Engine Load sounds good and the app is already pulling that value from the car if it supports this (e.g. see [1]). The "full tank fueling" approach is also something we are investigating currently together with a student (for his Bachelor thesis). He developes a concept for test drives (same route, same gas station, etc... ), but from a general perspective and not with a focus on Diesel consumption. We might establish some contact here if you are interested!

I am currently not aware of specific enviroCar contriibution guidelines. So maybe for the moment the approch could be to fork the enviroCar-app GitHub repository and simply start with some stuff. Once you have code you feel that should make it to the upstream, we can see how to include that.
 

3) In theory, there's a set of nonstandard PIDs for Renaults that I can use to obtain instand fuel consumption per stroke. I'm still struggling with obtaining this data via a simple python script, but there are success reports on the web. Ideally, it may be an even more accurate measure of consumption or at least one can use this data to estimate the relation between the engine load and consumption without having user to actually fill the car. But I'm not a law expert and I'm unsure if it's ok to publicaly use nonstandart PIDs in an opensource app. Could anybody comment?

I am also not sure from a legal perspective. I will try to get some feedback from colleagues who are a bit more familiar with legal issues. From a programming perspective I think this approach is a valuable alternative and we may be able to set up a sort of database for vendor-specific PIDs in the future - with the help people like you who are excited to contribute!


 

Kind regards,
-- 
Oleksiy Protas
National University «Kyiv-Mohyla Academy»

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Matthes Rieke
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