Analysis on Steering Gain and Vehicle Handling Performance with ...

Fig.9 Lane change during circular turning
with and without VGS during circular turning with
constant lateral acceleration is carried out. The computer
simulation model consists of 14 degrees of freedom
vehicle nonlinear model with combined slip type of tire
model. The tire model is a brush type one in which the
combined lateral and longitudinal forces are obtained by
integrating the distributed tire deformations in the
contact-patch. A small size passenger cars equipped with
VGS1 and VGS2 respectively are considered and the
1 st -order preview model is adopted for a human driver in
the simulation.
The simulated lane change responses during circular
turnings with lateral accelerations of 0.3G and 0.7G are
shown in Figs.11 and 12. It is found that the vehicle
responses with VGS1 become oscillatory with the increase
of the lateral acceleration from 0.3G to 0.7G as is pointed
out in the simulator study. However, the vehicle responses
with VGS2 still remains almost the same responses as that
of the conventional vehicle even under circular turning
with high lateral acceleration.
Fig.10 Results of simulator study
COMPUTER SIMULATION
In order to show the effects and the limit of the gain
adjustment of VGS, a computer simulation of the lane
change response of a closed-loop driver-vehicle-system
Fig.11 Lane change responses in turning with 0.3G lat.acc.
The yaw rate response of the vehicle with VGS1
compared with the response of the other vehicles in Fig.
13 shows unsymmetrical aspect between the lane changes
to inner and outer lanes especially during turning with
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