Author Topic: MaxTyre - A tool to visualize/edit the GPB tyre model  (Read 7837 times)

HornetMaX

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MaxTyre - A tool to visualize/edit the GPB tyre model
« on: December 27, 2014, 05:57:50 PM »
Hi all,

I've made a little tool to visualize the tyre model (Magic Formula) used by GPB. If you don't know what the Magic Formula is, the tool is *not* for you :)

NOTE: the tool is very much beta. The equations involved are messy and I cannot grant an error has not slipped in. If anybody with knowledge of this stuff wants to double check, that would be appreciated. I can send you the relevant source code for that, just PM me. Of course, if Piboso could validate all that, that would be ideal (but he probably has other things to do).

It can load two set of parameters (two .tyre files) to compare and modify them (only the Magic Formula parameters). It has 4 tabs, one for each graph:
  • Longitudianl force: as function of longitudinal slip (x axis) and of vertical load, side slip and camber (sliders).
  • Lateral force: as function of lateral slip (x axis) and of vertical load, longitudinal slip and camber (sliders).
  • Aligning torque: as function of lateral slip (x axis) and of vertical load, longitudinal slip and camber (sliders).
  • Lateral force vs Longitudinal  force: as function of vertical load, side slip, side slip and camber (sliders). Line is plotted for longitudinal slip between -1.00 and +1.00.
Any time a value is modified, the graphs are updated. Same any time a slider is moved. Double clicking on a slider will bring it back to its default position.

On each graph there are 4 lines: 2 for the 1st model (in blue), 2 for the second model (in red).
On the longitudinal force graph (for example), it draws (for each model) the line with zero side slip and zero camber (dashed line) and the line with the values of side slip and camber specified by the sliders.

Using shift+mousewheel and ctrl+mousewheel you can zoom in/out of the X/Y axes. shit/ctrl+drag will pan the X/Y axes. A double click will zoom out to full graph.



DOWNLOAD v1.6b (2017/05/16) : <<-- THIS if for GPB beta9/10/11 and MXB beta5/6 (subsequent versions TBC).

INSTALLATION: this is not a plugin, it's a standalone tool. Just copy it in a folder where you have write rights (i.e. avoid "Program Files" and similar). The sample files provided are the ones of the 3 default bikes in GPB beta8.

IMPORTANT: in case of issues like missing dlls or things not showing up, please install Microsoft Visual C++ 2015 Redistributable Package (x86). It's available in the .zip (vcredist_x86.exe) or you can download it at https://www.microsoft.com/en-US/download/details.aspx?id=48145 (download the x86 version, "vcredist_x86.exe", not the x64 version).
« Last Edit: May 16, 2017, 07:15:16 PM by HornetMaX »

JC#21

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Re: MaxTyre - A tool to visualize/edit the GPB tyre model
« Reply #1 on: December 27, 2014, 06:06:30 PM »
Nice work, I will try.
Thx Max

HornetMaX

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Re: MaxTyre - A tool to visualize/edit the GPB tyre model
« Reply #2 on: December 27, 2014, 11:48:32 PM »
v1.3 out: fixed a couple of things that should make things more correct at large side slip and/or camber angles.

I think I've found something strange, I'm making a post in the physics section.

MaX.

BOBR6 84

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Re: MaxTyre - A tool to visualize/edit the GPB tyre model
« Reply #3 on: December 29, 2014, 12:50:15 AM »
Very impressive stuff here MaX! Clearly not for me as it stands..
Could this be adapted in any way to work as some sort of telemetry? Would be really great to monitor what is actually happening with the tyres.. Not sure if that exists in real life but, who cares..

Ps.. Could you create a programe that sends all tax payers money to my bank acount? Thanks :)

HornetMaX

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Re: MaxTyre - A tool to visualize/edit the GPB tyre model
« Reply #4 on: December 29, 2014, 04:06:54 PM »
Very impressive stuff here MaX! Clearly not for me as it stands..
Could this be adapted in any way to work as some sort of telemetry? Would be really great to monitor what is actually happening with the tyres..
No, GPB only sends to the plugins the data you'd have on a real bike (well, I guess on a real bike you cold have some tyre data in the telemtry, like temp and pressure).

Ps.. Could you create a programe that sends all tax payers money to my bank acount? Thanks :)
As soon as I have some spare time :)

MaX.

C21

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Re: MaxTyre - A tool to visualize/edit the GPB tyre model
« Reply #5 on: December 30, 2014, 09:08:24 AM »
Nice and really impressive work MAX.  :)
# Member of the CAWS Racing Team #


HornetMaX

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Re: MaxTyre - A tool to visualize/edit the GPB tyre model
« Reply #6 on: December 31, 2014, 11:10:36 AM »
v1.4 out:
  • Added slider for Fz factor (Fz = Fz_factor * Fz0).
  • Added Fy vs Fx plot.
  • Added options to en/disable warning in comuptations and to mark points in graphs.
  • Some layout changes.
  • Minor improvements.

MaX.

h106frp

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Re: MaxTyre - A tool to visualize/edit the GPB tyre model
« Reply #7 on: January 01, 2015, 10:44:40 PM »
Found this looking for 'steering stuff', though it might be interesting as it builds on the magic formula. Bit (way) beyond anything i need though  ::)
http://alexandria.tue.nl/repository/books/598144.pdf

HornetMaX

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Re: MaxTyre - A tool to visualize/edit the GPB tyre model
« Reply #8 on: January 03, 2015, 09:03:40 PM »
Found this looking for 'steering stuff', though it might be interesting as it builds on the magic formula. Bit (way) beyond anything i need though  ::)
http://alexandria.tue.nl/repository/books/598144.pdf

Thanks for the link ! I'll take the time to read through it as soon as possible.

I took a very quick look at the content and noticed that one area of improvement was about taking into account the tyre profile: that's interesting (I posted a while ago about that), but keep in mind that GPB (overall, not only its tyre model) uses tyres with round profile, so ...

MaX.

Wh1t34Gl3(SAS)

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Re: MaxTyre - A tool to visualize/edit the GPB tyre model
« Reply #9 on: January 04, 2015, 01:50:18 AM »
I don't really know what's magic formula thing, but i see an incredible amount of work here. Great tool. ;D

h106frp

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Re: MaxTyre - A tool to visualize/edit the GPB tyre model
« Reply #10 on: January 04, 2015, 10:02:37 PM »
Found this looking for 'steering stuff', though it might be interesting as it builds on the magic formula. Bit (way) beyond anything i need though  ::)
http://alexandria.tue.nl/repository/books/598144.pdf

Thanks for the link ! I'll take the time to read through it as soon as possible.

I took a very quick look at the content and noticed that one area of improvement was about taking into account the tyre profile: that's interesting (I posted a while ago about that), but keep in mind that GPB (overall, not only its tyre model) uses tyres with round profile, so ...


MaX.

It seems a critical area to get right for a bike that behaves in a realistic manner, neat dodge having a round tyre but surely the important bit of the tyre that is in contact with the track is anything but round at this point? I would have thought this (profile) tied in with tyre pressures when setting up the bike?

HornetMaX

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Re: MaxTyre - A tool to visualize/edit the GPB tyre model
« Reply #11 on: January 04, 2015, 10:20:25 PM »
It seems a critical area to get right for a bike that behaves in a realistic manner, neat dodge having a round tyre but surely the important bit of the tyre that is in contact with the track is anything but round at this point?
Critical I don't know. The fact one assumes the tyre profile is round does not mean that the effects of tyre deformation (under vertical load) are neglected.
For sure a more general profile (the paper you linked uses elliptical) would be more "theoretically correct". Would it make a difference for us ? Don't know.

As we have the virtual rider in between us and the bike, the effect of a non-round profile could be not that visible to the player (the virtual rider taking care of it).

MaX.

HornetMaX

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Re: MaxTyre - A tool to visualize/edit the GPB tyre model
« Reply #12 on: October 30, 2015, 02:28:27 PM »
Replaced Google Drive download link with Mega download link (due to false positive virus detection on Google Drive).

MaX.

P.S.
If you want to check that the file has no virus, you can download it and check it on virustotal.com (free).
There's only 1 AV out of 55 that thinks it's a virus (ClamAV, I've contacted them and notified about the false positive).

Phathry25

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Re: MaxTyre - A tool to visualize/edit the GPB tyre model
« Reply #13 on: February 09, 2016, 03:15:54 AM »
Would it be possible to have this tool updated to support WRS?

As it stands it will only display the longitudinal curve.  And throws a bunch of unexpected key lines when loading.

HornetMaX

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Re: MaxTyre - A tool to visualize/edit the GPB tyre model
« Reply #14 on: February 09, 2016, 07:37:13 AM »
As it stands it will only display the longitudinal curve.  And throws a bunch of unexpected key lines when loading.
Not surprisingly, as it is done for GPB :) (bike tyres and car tyres do have different models).

I guess it is possible in principle at least for WRS and KRP, MXB would be a bit more complex, unless Piboso becomes unusually cooperative on the subject (but MXB is the sims has probably the smallest need for this tool). At them moment however development of all my tools is as dead as it can be, sorry.