Pacejka Tire Model

[Rainer Gericke]

Hello,

I have a question about the Pacejka tire model implemented in chrono.

When I define a new tire, is it necessary to provide the complete parameter set or is it possible to omit unknown parameters (for example when no combined slip data are available)?

Rainer

[Mike Taylor]

Rainer,

The Pacejka tire code was written by a previous lab member.  From what I could tell digging into it, the combined slip terms are always calculated and all of the Pacejka parameters are expected in the file in the correct order.  So that means you need values for all of the coefficients every time.

This means that if you do not have some of the coefficients, you can still use the code, but some extra preparation is required.  You will need to find the definition for the PAC2002 equations which will explain how each coefficient is used.  For the coefficients that you are missing, you'll need to determine how to ignore its effects.  For example, if it's a scaling factor, you might set it to 1 or if it was a curve shift the you could set it to 0.  The exact values to ignore those terms will have to be set uniquely for each coefficient.

Hopefully that helps,

Mike