- #1

synMehdi

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Hi, I'm simulating the behavior of a car and I have some troubles with the tires. Specially with slip when the car is accelerating.

I've seen many documents over the internet and I understood 2 main things: Wheel slip is necessary to accelerate & the coefficient of friction depends on the slip.

To model a Tyre I'm using Pacejka magic formula which describes the relation between the coefficient of friction and the slip.

If I put torque (car speed=0 & wheel speed=0) in the wheel, there is no slip initially and no force to push the car. The wheel will slip due to the torque, and friction will occur which accelerates the car.This will eventually decrease slip. At some point an equilibrium will occur.

Am I right?

If my torque is bigger than the maximum force of the Pacejka formula (around slip=8%), Am I going to diverge?because friction will decrease when slip increases after that point.

I don't feel that this is what occurs in real life or maybe I didn't understand the wheel model.

I've seen many documents over the internet and I understood 2 main things: Wheel slip is necessary to accelerate & the coefficient of friction depends on the slip.

To model a Tyre I'm using Pacejka magic formula which describes the relation between the coefficient of friction and the slip.

If I put torque (car speed=0 & wheel speed=0) in the wheel, there is no slip initially and no force to push the car. The wheel will slip due to the torque, and friction will occur which accelerates the car.This will eventually decrease slip. At some point an equilibrium will occur.

Am I right?

If my torque is bigger than the maximum force of the Pacejka formula (around slip=8%), Am I going to diverge?because friction will decrease when slip increases after that point.

I don't feel that this is what occurs in real life or maybe I didn't understand the wheel model.

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