For the purpose of controlling the yaw dynamics and lateral dynamics in a road
vehicle with electrically controlled four-wheel steering, in the case of which
the setting of the front axle steer angle v and of the rear axle
steer angle h is performed by means of mutually decoupled control
loops, a desired value vsoll for the lateral force Sv to
be built up at the front axle is determined in the control loop assigned to the
front axle and, for this desired value Svsoll, the value of the slip
angle, linked to the desired value Svsoll, is determined as desired
value vsoll from an Sv(v) characteristic
representing the dependence of the lateral force Sv, to be built up
at the front axle, on the slip angle v. In the control loop assigned
to the rear axle, a desired value Shsoll for the lateral force Sh
to be built up at the rear axle is determined in a control process in accordance
with a controller law of the form
##EQU1##
and, for this desired value Shsoll, the value of the slip angle,
linked to the desired value Shsoll, is determined as desired value hsoll
from an Sh(h) characteristic. These desired values
vsoll and hsoll are used to determine the desired
values vsoll and hsoll of the steer angle,
taking account of an estimated value of the sideslip angle at the center
of gravity of the vehicle, the position of the center of gravity and measured or
estimated values of the yaw velocity {dot over ()} and of the longitudinal
speed vx of the vehicle.
