One of the most common questions that I get asked as a simulation principle is what happens when I don’t have tyre data, or I have serious doubts about the tyre data I have been given. It’s an important question because if your base model is way off it can take a lot of time to get yourself back on track.
Fortunately the fix for this is actually pretty simple, and the basis of it comes as a spin off from using a second order curve fit of the traction circle radius vs load characteristic. If you can combine this with some baseline simulated or actual data, not only can you get a really good start point but you’ll also get a good idea of setup sensitivities.
This technique is something I’ve been using in the ChassisSim community recently to good effect. It’s a great example of hand calculations meeting computer aided engineering, which makes this discussion even more relevant.
To kick off this discussion it’s worth revisiting the second order fit of:
