Sign of tire forces in sumN for MP vehicle model

Benchmark & Challenges
1

Hi,

on page 18 vehicleModels_commonRoad.pdf · master · tum-cps / commonroad-vehicle-models · GitLab (lrz.de), in the auxiliary variables sprung mass the sumN considers to my understanding the induced torques around the z-axis of the vehicle body frame by the tire forces. It appears to me, that the signs of the tire forces in x-direction are accounted with a wrong sign.

My assumption is that the body frame of the vehicle is such that x points in longitudinal direction, z points upwards and by right.hand rule y points to the left.

For example, the tire force left rear Fx,LR is regarded with a positive sign in the equation, i.e. accelerating the yaw-angle in positive direction (increasing it), although from the defintion of the yaw-angle it should accelerate it in the negative direction (decrease it).
The inverse is the case for Fx,RR and Fx,LF, Fx,RF rotated by x3 respectively.

Can someone explain to me the sign of these forces in the equation for sumN?

Thanks and best regards,
Timo

2

Hi Timo,

I had a brief look at the equations and it seems you are right: The signs for the longitudinal tire forces which are multiplied with the front and rear track widths should be reversed. We will check it again in detail and correct it in the PDF and the code.

Thanks for notifying us.
Best,
Gerald