1. Projet 4: Investigation of the vehicle dynamics stability
Simon Bauduin,
Pierre Duysinx,
LTAS-Automotive Engineering Research Group-University of Liège

2. Use the theoretical model to compute the behavior of the car
Calcul du comportement d’un véhicule en virage
Use the theoretical model to compute the behavior of the car
Characteristic of the car:
Wheelbase = 2.4 m
I = 1760 kgm2
b = m
M = 1190
Cαf = N/rad
Cαr = N/rad
Various response to calculate
Low speed cornering responses:
Evolution of steering angle, Lateral acceleration and yaw speed gain, sideslip angle for a turning radius of 150m and a speed going from 0-70 m/s
Modelize the car as a linear time invariant model (LTI)
Study the stability of the system for the speed going from 0-70 m/s
The step response of the dynamic system for a speed going from 0-50m/s
The impulse response of the dynamic system for a constant speed of 10,25,50 m/s
Modify the characteristic of the car to have a neutral, understeer and oversteer behavior

3. Low speed cornering responses
Use the bicycle model and its hypothesis.
For a speed going from 0 and 70 m/s and a turning radius of 150 m
Steering angle:
Lateral acceleration gain :
Yaw speed gain:
Sideslip angle :

4. Modelize the car by a LTI model
Use the LTI model to dertermine the stability responses.
with
-Study the stability of the model by analyzing the roots of the model
-The step response of the dynamic system for a speed going from 0-50m/s
-The impulse response of the dynamic system for a constant speed of 10,25,50 m/s
Compare with the three different behaviors:
-Understeer
-Neutral
-Oversteer