Method for ascertaining the stress level of the driver
In a method for ascertaining the stress level of the driver, the setpoint trajectory of the vehicle is ascertained and compared to the actual trajectory. A higher stress level is inferred from an increasing frequency and/or magnitude of the deviation of the actual trajectory from the setpoint trajectory.
1. A method for ascertaining a stress level of a driver of a vehicle, comprising:
determining one of a setpoint trajectory of the vehicle and a state variable correlating with the setpoint trajectory;
comparing the one of the setpoint trajectory and the state variable respectively to at least one of an actual trajectory and a state variable correlating with the actual trajectory;
inferring a higher stress level from an increasing driver reaction, wherein the increasing driver reaction includes at least one of an increasing frequency and a magnitude of a deviation of one of the actual trajectory from the setpoint trajectory and the state variable correlating with the setpoint trajectory from the state variable correlating with the actual trajectory; and
taking a stress-reducing measure as a function of the stress level.
2. The method as recited in claim 1 , wherein the setpoint and actual trajectories, or state variables correlating therewith, are determined together in the transverse and longitudinal directions and compared.
3. The method as recited in claim 1 , wherein a variance is ascertained from the difference between the actual and the setpoint trajectory, or the correlating state variable, the variance being used as a measure of the stress level.
4. The method as recited in claim 3 , wherein a weighted sum of variances of multiple state variables is used as a measure of the stress level.
5. The method as recited in claim 1 , further comprising:
comparing setpoint and actual progressions of a steering angle.
6. The method as recited in claim 1 , wherein the setpoint trajectory, or the state variable correlating therewith, is determined from measuring data of a surroundings sensor system in the vehicle.
7. The method as recited in claim 1 , wherein the setpoint trajectory represents that driving line which is to be driven with minimal steering effort.
8. The method as recited in claim 1 , wherein driver inputs including steering inputs or pedal actuations are implemented in a reduced manner as the stress-reducing measure.
9. The method as recited in claim 1 , wherein characteristic curves in a vehicle unit or a driver assistance system are modified in a brake assistance system as the stress-reducing measure.
10. The method as recited in claim 9 , wherein characteristic curves are changed for the benefit of a higher driving comfort as the stress-reducing measure.
11. The method as recited in claim 1 , wherein the higher stress level is inferred additionally based on an intensified pedal actuation by the driver.
12. A control unit for carrying out a method for ascertaining a stress level of a driver of a vehicle, the method comprising:
determining one of a setpoint trajectory of the vehicle and a state variable correlating with the setpoint trajectory;
comparing the one of the setpoint trajectory and the state variable respectively to at least one of an actual trajectory and a state variable correlating with the actual trajectory;
inferring a higher stress level from an increasing driver reaction, wherein the increasing driver reaction includes at least one of an increasing frequency and a magnitude of a deviation of one of the actual trajectory from the setpoint trajectory and the state variable correlating with the setpoint trajectory from the state variable correlating with the actual trajectory; and
taking a stress-reducing measure as a function of the stress level.
13. A driver assistance system in a vehicle, comprising:
a control unit for carrying out a method for ascertaining a stress level of a driver of a vehicle, the method comprising:
determining one of a setpoint trajectory of the vehicle and a state variable correlating with the setpoint trajectory;
comparing the one of the setpoint trajectory and the state variable respectively to at least one of an actual trajectory and a state variable correlating with the actual trajectory;
inferring a higher stress level from an increasing driver reaction, wherein the increasing driver reaction includes at least one of an increasing frequency and a magnitude of a deviation of one of the actual trajectory from the setpoint trajectory and the state variable correlating with the setpoint trajectory from the state variable correlating with the actual trajectory; and
taking a stress-reducing measure as a function of the stress level.
14. The system as recited in claim 13 , wherein the setpoint and actual trajectories, or state variables correlating therewith, are determined together in the transverse and longitudinal directions and compared.
15. The system as recited in claim 13 , wherein the variance is determined from a sum of the deviations from a mean value squared, as follows:
s
2
=
1
n
-
1
∑
i
=
1
n
(
x
i
-
x
_
)
2
,
where n denotes the number of data points, x i denotes a respective data value, and x denotes a mean value of the data.
16. The system as recited in claim 15 , wherein a weighted sum of variances of multiple state variables is used as a measure of the stress level.
17. The system as recited in claim 13 , wherein setpoint and actual progressions of a steering angle are compared.
18. The system as recited in claim 13 , wherein the setpoint trajectory, or the state variable correlating therewith, is determined from measuring data of a surroundings sensor system in the vehicle.
19. The system as recited in claim 13 , wherein the setpoint trajectory represents that driving line which is to be driven with minimal steering effort.
20. The system as recited in claim 13 , wherein driver inputs including steering inputs or pedal actuations are implemented in a reduced manner as the stress-reducing measure.
21. The system as recited in claim 13 , wherein characteristic curves in a vehicle unit or a driver assistance system are modified in a brake assistance system as the stress-reducing measure.
22. The system as recited in claim 21 , wherein characteristic curves are changed for the benefit of a higher driving comfort as the stress-reducing measure.
23. The system as recited in claim 13 , wherein the higher stress level is inferred additionally based on an intensified pedal actuation by the driver.
24. The system as recited in claim 13 , wherein a variance is ascertained from the difference between the actual and the setpoint trajectory, or the correlating state variable, the variance being used as a measure of the stress level.
25. The control unit as recited in claim 12 , wherein a variance is ascertained from the difference between the actual and the setpoint trajectory, or the correlating state variable, the variance being used as a measure of the stress level.