Method for partially or fully autonomously guiding a motor vehicle
A method for partially or fully autonomously guiding a motor vehicle includes setting a target steering angle for guiding along a target trajectory. It is checked whether a zero point shift exists between a current position of the motor vehicle with respect to the target trajectory. The set target steering angle is adjusted on the basis of a correction constant in the event that a determined zero point shift exceeds a predefined threshold.
1. A method for partially or fully autonomously guiding a motor vehicle, comprising:
setting a target steering angle for guiding the motor vehicle along a target trajectory;
determining a zero point shift between a current position of the motor vehicle and the target trajectory; and
adjusting the set target steering angle based on a correction constant in response to the determined zero point shift exceeding a predefined threshold,
wherein the correction constant is determined on the basis of the determined zero point shift and a factor, wherein the factor is determined by a single-track model and subsequently adjusted to vehicle-specific parameters of the motor vehicle.
2. The method according to claim 1 , wherein a static zero point shift is exclusively corrected on the basis of the correction constant, wherein in order to establish a zero point shift as static, an offset curve with respect to the target trajectory is determined over a specified time window and the determined offset curve is averaged, wherein the mean value is acquired as a static zero point shift in the event that the latter has exceeded a predefined correction threshold, wherein a correction offset is specified by means of the acquired zero point shift, by means of said correction offset the set target steering angle is adjusted.
3. The method according to claim 2 , wherein the determined zero point shift is corrected in a stable manner.
4. The method according to claim 3 , wherein the adjustment of the set target steering angle on the basis of the correction constant is excluded in the event that interference effects have been determined, which adversely affect the determination of a static zero point shift.
5. The method according to claim 4 , wherein a check of a zero point shift and adjustment of the correction constant take place cyclically, wherein in the case of delay signals which influence the zero point shift, these are considered in a subsequent cycle.
6. The method according to claim 4 , wherein the determined interference effects are determined by sensors of the motor vehicle and comprise at least one of crosswind or an inclined roadway.
7. The method according to claim 1 , wherein the zero point shift with respect to the target trajectory is determined based on camera image data of a vehicle camera unit.
8. The method according to claim 1 , wherein the factor is based upon at least one of mass of the motor vehicle, a distance between a center of gravity of the motor vehicle and a front axle thereof, a distance between the center of gravity and a rear axle of the motor vehicle, transverse stiffness of the front axle, transverse stiffness of the rear axle, or a speed of the motor vehicle.
9. The method according to claim 1 , wherein the factor is represented by
Factor
=
l
+
m
l
(
l
h
C
a
h
-
l
v
C
a
v
C
a
v
C
a
h
)
v
2
where m is motor vehicle mass, l v is a distance between a center of gravity of the motor vehicle and a front axle thereof, l h is a distance between the center of gravity and a rear axle of the motor vehicle, C av is a transverse stiffness of the front axle, C ah is a transverse stiffness of the rear axle, and v is motor vehicle speed.
10. The method according to claim 1 , wherein the correction constant is represented by
Correction
constant
=
f
a
c
t
o
r
+
zero
point
shift
f
a
c
t
o
r
.
11. A device for partially or fully autonomously guiding a motor vehicle along a target trajectory, comprising:
a servo drive having a motor; and
an electronic control unit for actuating the motor;
wherein the electronic control unit is configured to carry out a method comprising
setting a target steering angle for guiding the motor vehicle along a target trajectory,
determining a zero point shift between a current position of the motor vehicle and the target trajectory, and
adjusting the set target steering angle based on a correction constant in response to the determined zero point shift exceeding a predefined threshold,
wherein the correction constant is determined based on the determined zero point shift and a factor, wherein the factor is determined by a single-track model and subsequently adjusted to vehicle-specific parameters of the motor vehicle.
12. The device according to claim 11 , wherein a static zero point shift is exclusively corrected on the basis of the correction constant, wherein in order to establish a zero point shift as static, an offset curve with respect to the target trajectory is determined over a specified time window and the determined offset curve is averaged, wherein the mean value is acquired as a static zero point shift in the event that the latter has exceeded a predefined correction threshold, wherein a correction offset is specified by means of the acquired zero point shift, by means of said correction offset the set target steering angle is adjusted.
13. The device according to claim 11 , wherein the adjustment of the set target steering angle on the basis of the correction constant is excluded in the event that interference effects have been determined, which adversely affect the determination of a static zero point shift, the determined interference effects are determined by sensors of the motor vehicle and comprise at least one of crosswind or an inclined roadway.
14. The device according to claim 11 , wherein the factor is based upon at least one of mass of the motor vehicle, a distance between a center of gravity of the motor vehicle and a front axle thereof, a distance between the center of gravity and a rear axle of the motor vehicle, transverse stiffness of the front axle, transverse stiffness of the rear axle, or a speed of the motor vehicle.
15. The device according to claim 11 , wherein the factor is represented by
Factor
=
l
+
m
l
(
l
h
C
a
h
-
l
v
C
a
v
C
a
v
C
a
h
)
v
2
where m is motor vehicle mass, l v is a distance between a center of gravity of the motor vehicle and a front axle thereof, l h is a distance between the center of gravity and a rear axle of the motor vehicle, C av is a transverse stiffness of the front axle, C ah is a transverse stiffness of the rear axle, and v is motor vehicle speed.
16. The device according to claim 11 , wherein the correction constant is represented by
Correction
constant
=
f
a
c
t
o
r
+
zero
point
shift
f
a
c
t
o
r
.