Hi Rainer, What happened to the transient extension of the Pacejka steady-state equations detailed in TR-2011-02 <https://sbel.wisc.edu/wp-content/uploads/sites/569/2018/05/TR-2011-02.pdf>? Is this what you are referring to as the features that no one uses?
Also, is this the MATLAB tool you are referring to: 111375-magic-formula-tyre-tool <https://www.mathworks.com/matlabcentral/fileexchange/111375-magic-formula-tyre-tool>. In vehicle modeling, tires are everything. If there are tools that are common to use to fit tire models to data, it would be very nice to have those same tire models supported in Chrono. Relaxation length is one of the most used tire properties in tire modeling (same with pneumatic trail). The Fiala tire model supports this. It looks like the ChPacejkaTire supports this in Release/8.0.0, but it has since been removed in main. Also, CarSim supports Pacejka 5.2 and MFSwift tire models. This would indicate these models are standards and seem far more conventional than some of the other tire models supported by Chrono. It would be nice to have them supported in Chrono too. On Sunday, January 7, 2024 at 2:05:51 AM UTC-8 [email protected] wrote: > Hi Rainer, > > thank you very much for the explanation! I'll try my luck with the Pac2002 > model. If I get around to validating the car and tire models after the > season, I may come back here and report on our results. > > Sincerely, > Thorsten > > [email protected] schrieb am Samstag, 6. Januar 2024 um 15:38:55 UTC+1: > >> Hi Thorsten, >> >> the MFTire class was a c++ port of the Matlab tool. It contained a lot of >> features, nearly all proposed bei Hans Pacejka in his book. The original >> authors know, that many of these features or not used by anybody. They made >> analyses of the commercial MFTire solutions used e. g. in ADAMS for this >> and privided a switch to deactivate those features. We decided not to >> maintain code that nobody ever is going to use, that is the main reason to >> drop c++-MFTire as tire model in chrono. The c++ port was extremely buggy, >> that showed a test a test with a validated vehicle model (Fed-Alpha) >> equipped with validated Pacejka 2002 tire files (donated by Goodyear). Btw. >> our former Pac02 model worked well with it! We decided to rewrite it yet, >> to give it a more readable structure and to implement a parser for >> ADAMS/Car compatible *.tir files. It should be easier to use now. >> >> We definitely don't have all possible functions implemented. Only steady >> state and combined forces can be used. Inflation pressure dependent data >> sets can be probably used but have not been tested, because we don't have >> validated example files for it. So if you have fitted tire parameters for >> your race car, you should Pac02 in chrono give a try. >> >> Best, >> Rainer >> >> [email protected] schrieb am Freitag, 5. Januar 2024 um 23:12:01 UTC+1: >> >>> Hi all, >>> >>> I am currently trying to simulate a racing car in Project Chrono. As >>> such the tire simulation is very important to me. I fitted a magic formula >>> v61 model to my experimental data and while browsing through the pull >>> requests I found that there is/was a MFTire class for the versions 61 and >>> 62 of the magic formula in Chrono. Since I didn't find this code in the >>> current main branch I did a little deep dive and found out that the >>> corresponding class was deleted in 4f7c0ea8f6b10896459c1867551858706f083632 >>> on the 8th of June 2023 in the process of reworking the Pacejka2002 tire. I >>> was a little confused by this since I thought that the MF version 61 and 62 >>> are way newer than 2002 (imo 2008 atleast). Therefore I wanted to ask >>> whether the Pac2002 tire contain all the formulas for the current MF >>> versions or what the process was behind removing this class. >>> >>> Sincerely, >>> Thorsten >>> >> -- You received this message because you are subscribed to the Google Groups "ProjectChrono" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/projectchrono/6710751f-1526-4eb1-bea4-9a031792456cn%40googlegroups.com.
