Method for ascertaining the stress level of the driver

Patent metadata

Field	Value
Publication number	US-9475501-B2
Application number	US-201414574569-A
Country	US
Kind code	B2
Filing date	Dec 18, 2014
Priority date	Dec 19, 2013
Publication date	Oct 25, 2016
Grant date	Oct 25, 2016

Abstract

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.

First claim

What is claimed is:

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

Assignees

• Bosch Gmbh Robert

Inventors

• Flehmig Folko
• Marberger Claus
• Gussner Thomas

Classifications

• B60W2556/50

  of positioning data, e.g. GPS [Global Positioning System] data · CPC title

• B60W2540/22

  Psychological state; Stress level or workload · CPC title

• B62D6/00

  Arrangements for automatically controlling steering depending on driving conditions sensed and responded to, e.g. control circuits (means for initiating a change in direction B62D1/00; steering valves B62D5/06; combined with means for inclining the vehicle body or wheels on bends B62D9/00) · CPC title

• B60T7/22

  initiated by contact of vehicle, e.g. bumper, with an external object, e.g. another vehicle {, or by means of contactless obstacle detectors mounted on the vehicle} · CPC title

• B60W2050/0083

  Setting, resetting, calibration · CPC title