Hello, I'm Thomas Sanguinetti with Siemens PLM Software, and today I'm going to show you
how OEMs will be able to estimate the emissions fuel consumption for
real driving cycles, using LMS Imagine.Lab Amesim 15.
So in order to do that, we have two possible scenarios.
First to use recorded data from GPS logs, or use maps, open street maps,
to configure yourself your own response for your car.
So, to begin we open some standard demo, provided with LMS Amesim.
So first go to your help menu, and then get LMS Amesim demos.
Then go to your libraries tree, drive library, and select the gasoline vehicle
and manual gearbox on real cycles.
Press the "copy and open" button, and your demo will open in LMS Amesim.
From here, we start with the first option where we will use a GPS logs.
For my example, I just looked over the Internet for some GPS tracks recordings,
with waypoints in the death valley.
So I will open my folders, look for my death valley files and you can see
here I found some GPX file, where all the different coordinates was told.
You can have the same information using your own GPS.
First step with LMS Amesim will be to create the road from those GPS tracks.
So first we will use the AMETrack tool, provided by the vehicle dynamics library.
So, click on the AMETrack link to open the app.
First we will select the GPX file, so I'm going directly into my folder,
select the GPX file.
Then I will create some folder to store all the different visualization and the file generated by the tool.
Press "generate" and the tool will work by itself.
It takes only a few sets of seconds. I had to compute the road.
When it is done, now the second tip will be to define the territory
for the vehicle, and generate some speed profile
which will be used during the simulation.
For that, we launch an additional tool in Python.
So you need to click on the blue label on top of your toolbar.
It will launch the territory import tool.
Go to the second tab, and click on the "GPS log or track file".
From there, we go again in our death valley file, and select way1.data.
This is the file generated by the previous tool, which will be used in our simulation.
You can see that it has found one track,
with a total lenght of 227 kilometers.
Then we go to the third tab, where our GPX file was analyzed and shown on this interface.
Ok, so now, I will compute the velocity profile.
We only need a set of few parameters.
First the maximum allowed driving speed we will use for our car,
then the maximum acceleration our car can go in curves, its mass, maximum power and top speed.
From that, you can see here we have the speed profile as
a function of our distance, for the entire GPX file.
If we zoom in, we can see, here, that we are
almost always at the top allowed speed, and then for some curves there is a deceleration.
From here we save this file. So click on the "save data file"
over your plot window, and in the same folder, you will save the speed profile.
Just typing some name, death valley, 227 kilometers.
Once this step is done, we have a few adjustments to make, for the speed profile.
we will use the table editor, within LMS Amesim,
to open the file and edit some few values.
So, I will load the previous file.
One of the conditions is that must start at a the new vehicle speed,
and also finish at the new vehicle speed.
So first value, as you can see, that initial value, so we just typing "0",
and we will do the same for the last part. You can save the file.
Then also interesting point for real driving emissions,
is that we need to add some stops: traffic signs, stop signs.
so we will choose some points, here for instance, and at this moment,
we will enter a new vehicle speed to simulate a vehicle stop.
So it's about one hundred and eighty-two kilometers,
so I change the value around here.
As you can see, a stop has been added to the file. Then save, and close the table editor.
Now that we have created our own file or cycle,
we need to enter some parameters to simulate our vehicle.
So first, I will generate some engine maps. In case you don't have any data,
there is an extra tool, which should allow with macro parameters, to create the maps.
Click on your IFP-engine drive model, and launch the first app.
As you can see, in six steps we will be able to create our own engine.
So in my case, I used in-line engine, regular car, not turbocharged, simple dynamic,
4 cylinders, 1.4 liters. The only parameter question here is the stroke.
Then we will define if it is a gasoline or a diesel engine.
In our case it is a gasoline engine.
We will also need to define some maximum torque,
and maximum power at different engine speed.
So, for that, we will look into my data saved through set of information.
So, it's, as I said 1.4 liters and we have a maximum power of 110 kilowatts.
You know, that it is the case between 5000 and 6000 thousand rpm.
So we enter the value accordingly,
say 5000, and for the maximum power, we will for maximum torque reuse these
values so 250 Newton meters at 1500 rpm.
Then go to the fourth step where we will compute all the different maps.
You can then visualize the table created, so this one is for the torque.
You also have the fuel consumption map. Finally, the final step is to generate those maps.
So I will click on the "generated selected tables",
create some folders for this engine; called new engine.
The tables are correctly generated.
We will see that the parameters settings are already done, within this submodel.
So this is over for the engine part.
Now we will need to find the gear ratio for a vehicle gearbox.
As for the engine I found those values over the internet, there are difficult to find.
Also for the final gear issue, it is also provided, so no difficulty here.
For the vehicle part, three main information are requested;
tire dimension, mass and also the front surface and the drag of your vehicle.
Also provided usually on the manufacturers website, or on some journals,
automotive publications where those information are available.
So in our case, we are about 1.3 tonnes for the vehicle mass, and I found
the air penetration coefficient and also the front area.
So, that's the only parameter requested here,
and finally to launch the simulation, I will use in our mission profile,
the speed profile we generated previously.
So, the one with one stop,
and also, for each stop we need to set up a file saying how long we stayed at this position.
So this file is quite simple for each stop. So, in our case we have a first stop
at the beginning, a stop at the end, and the extra stop we added in the middle of our cycle.
So, we will have three values in this file.
So, for the first stop, I will stay three seconds,
second stop it's about a minute and then, at the end, so it has not so much
importance, but we will just put zero second.
Now we have set up all our sketchs, and we can launch the simulation.
As you can see, simulation is running and we can directly open some plot configuration
saved within the demo, to see the evolution through time, over speed.
As you can see we have the reference speed target,
the vehicle target speed we have in our simulation.
Also the gearbox management, gear ratio and the upper and lower shift engine speed.
Driver outputs, acceleration, brake control and finally
the fuel consumption and emissions for the whole simulation.
So here are final results, where we can see the cumulative fuel consumption over the 220 kilometers.
So, with the assumption that we had no data at all to simulate the engine, the result
does not seem incoherent with such consumption, and we can also zoom in for the instantaneous
fuel consumption to see, regarding our cycles,
where are the points where we used too much fuel.
Also for engineers, it would be a good way to detect
which operating points for the engine are not optimized.
Well, that's it for me, so just as a remember
with the new real driving emissions cycles, what you about to do.
First use recordings, so GPS logs directly within LMS Amesim.
We can also use open street maps, we can import from the open
street maps database layouts, and then use the same process, using AMETrack,
to create the ways, then the territory tool to compute the velocity profile and
then use our LMS Amesim sketch to compute fuel consumption and emissions.
Thank you for watching, and for more information please visit our website.