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DE-102024133126-A1 - Warning a driver of a vehicle

DE102024133126A1DE 102024133126 A1DE102024133126 A1DE 102024133126A1DE-102024133126-A1

Abstract

The invention relates to a method and a warning device (100) for warning a driver (204) of a vehicle (201). In the method, images of the driver's (204) face are captured using an interior camera (101) arranged in the vehicle (201). In each image captured by the interior camera (101), the pupil size of the driver's (204) pupil is determined. A change in lighting conditions is associated with an expected pupillary light reflex of the driver (204), and the actual pupillary light reflex of the driver (204) in response to the change is determined based on the pupil sizes. If there is a significant deviation of the actual pupillary light reflex from the expected pupillary light reflex, a warning signal is issued to the driver (204).

Inventors

  • Karl Fellerer
  • Matthias Georgi

Assignees

  • JOYNEXT GMBH

Dates

Publication Date
20260513
Application Date
20241113

Claims (13)

  1. Method for warning a driver (204) of a vehicle (201), wherein - images of the driver's (204) face are taken with an interior camera (101) arranged in the vehicle (201), - the pupil size of a pupil of the driver (204) is determined in images taken by the interior camera (101), - the actual pupillary light reflex of the driver (204) in response to a change in lighting conditions is determined and compared with an expected pupillary light reflex, and - a warning signal is issued to the driver (204) if there is a significant deviation of the actual pupillary light reflex from the expected pupillary light reflex.
  2. Procedure according to Claim 1 , wherein a change in the lighting conditions is effected by means of a light source (105) arranged in the vehicle (201).
  3. Procedure according to Claim 2 , wherein the light source (105) emits a light pulse perceptible to the driver (204).
  4. Method according to one of the preceding claims, wherein images of an environment (206) in front of the vehicle (201) are taken with a front camera (102) arranged in or on the vehicle (201) and the images taken by the front camera (102) are evaluated to determine a change in the lighting conditions.
  5. A method according to one of the preceding claims, wherein - a road course of a road (202) travelled by the vehicle (201) is determined, - an expected steering behavior of the driver (204) is assigned to the road course, - the expected steering behavior is compared with an actual steering behavior of the driver (204), and - the warning signal is issued if the actual steering behavior deviates significantly from the expected steering behavior.
  6. Procedure according to Claim 5 , wherein the actual steering behavior of the driver (204) is determined on the basis of sensor signals from a steering angle sensor of the vehicle (201).
  7. Procedure according to Claim 5 or 6 , the road course is determined using images taken by a front camera (102) of the vehicle (201) or by means of a navigation device.
  8. Method according to one of the preceding claims, wherein - in images taken by the interior camera (101) an actual color of a sclera of an eye of the driver (204) is determined, - the actual color is compared with an expected color of the sclera, and - the warning signal is issued if the actual color differs significantly from the expected color of the sclera.
  9. Warning device (100) for warning a driver (204) of a vehicle (201), the warning device (100) comprising: - an interior camera (101) arranged in the vehicle (201), which is configured to take pictures of the driver's (204) face, - an image evaluation unit (103) which is configured to determine the pupil size of a driver's (204) pupil in each image taken by the interior camera (101), - a control unit (104) which is configured to correlate a change in lighting conditions with an expected pupillary light reflex of the driver (204), to determine the actual pupillary light reflex of the driver (204) in response to the change based on pupil sizes determined by the image evaluation unit (103), and to output a warning signal to the driver (204) in the event of a significant deviation of the actual pupillary light reflex from the expected pupillary light reflex. initiate, and - an output unit (106) arranged in the vehicle (201) which is equipped to output the warning signal.
  10. Warning device (100) according to Claim 9 with a light source (105) arranged in the vehicle (201) which is designed to change the lighting conditions.
  11. Warning device (100) according to Claim 10 , wherein the light source (105) is configured to emit a light pulse perceptible to the driver (204).
  12. Warning device (100) according to one of the Claims 9 until 11 with a front camera (102) arranged in or on the vehicle (201) which is designed to take pictures of an environment (206) in front of the vehicle (201), wherein the image evaluation unit (103) is designed to determine a change in the lighting conditions in pictures taken by the front camera (102).
  13. Warning device (100) according to one of the Claims 9 until 12 , wherein the image evaluation unit (103) is configured to determine the actual color of the sclera of the driver's eye (204) in images taken by the interior camera (101), and the control unit (104) is configured to compare the actual color with an expected color of the sclera and to initiate the output of the warning signal if the actual color differs significantly from the expected color of the sclera.

Description

The invention relates to a method and a warning device for warning a driver of a vehicle. To participate safely in road traffic, a driver must possess sufficient skills in terms of reaction time, concentration, perception, and attention. These skills can be impaired by factors such as illness, medication, alcohol or drug use, or driver fatigue. For example, such impairments can cause microsleep, where the driver briefly falls asleep and thereby causes a traffic accident. Furthermore, deficits in reaction time, concentration, perception, or attention can lead to the driver failing to avoid an obstacle or other road user in time, or braking too late. The invention is based on the objective of reducing hazards to road traffic caused by impairments to the driving ability of a driver of a vehicle, for example due to illness, medication intake, alcohol consumption, drug use or fatigue. The problem is solved according to the invention by a method having the features of claim 1 and a warning device having the features of claim 9. Advantageous embodiments of the invention are the subject of the dependent claims. The problem is solved according to the invention by a method for warning a driver of a vehicle, wherein - images of the driver's face are taken using an interior camera installed in the vehicle, - in images taken by the interior camera, the pupil size of each of the driver's pupils is determined, - a change in lighting conditions is assigned an expected pupillary light reflex of the driver, and an actual pupillary light reflex of the driver in response to the change is determined based on the pupil sizes, and - if there is a significant deviation of the actual pupillary light reflex from the expected pupillary light reflex, a warning signal is issued to the driver. A pupillary light reflex refers to a change in the pupil size of a person's eye in response to a change in light conditions, more precisely, a change in the amount of light entering the eye. This change in pupil size occurs with a delay after the change in light conditions, for example, 1 to 3 seconds. Normal ranges for pupillary light reflexes can be defined for changes in light conditions, which are characteristic of individuals whose pupillary light reflexes are not impaired by illness or other factors such as medication, alcohol consumption, drug use, or fatigue. Therefore, a pupillary light reflex response to a change in light conditions that falls outside the normal range associated with that change may indicate an underlying illness or an impairment caused by factors such as medication, alcohol consumption, drug use, or fatigue. The method according to the invention aims to detect indications of impairments to a driver's ability to drive and to warn the driver when such an indication is detected. The method utilizes the indicator properties of the driver's pupillary light reflexes for certain illnesses and impairments, as described above. Therefore, according to the invention, the driver's pupillary light reflex is determined in response to a change in lighting conditions and compared with an expected pupillary light reflex. The expected pupillary light reflex is, for example, related to the normal range associated with this change in lighting conditions. For example, the expected pupillary light reflex is a mean pupillary light reflex within the normal range. To determine the driver's pupillary light reflex, images of the driver's face are captured using an interior camera mounted in the vehicle, and the driver's pupil size is measured in these images. If the driver's actual pupillary light reflex deviates significantly from the expected pupillary light reflex, a warning signal is issued to the driver. A significant deviation is defined, for example, with respect to the normal range. An actual pupillary light reflex is considered significantly different from the expected pupillary light reflex if it falls outside the normal range or exceeds a suitably defined maximum relative or absolute deviation. The mean pupillary light reflex deviates from the normal range. For example, a significant deviation of the actual from the expected pupillary light reflex can also be derived from a variance in a statistical distribution of pupillary light reflexes in different people, in particular from the variance of a statistical distribution from which the normal range was derived. A warning signal can be, for example, a visual signal, an acoustic signal, or a combination of a visual signal and an acoustic signal. An optical signal is displayed, for example, on a screen located in the vehicle. This optical signal might be a graphical alarm and/or a written instruction for the driver to stop driving. An acoustic signal is emitted, for example, through a loudspeaker unit located in the vehicle. This acoustic signal could be, for instance, an audible alarm and/or a spoken prompt for the driver to stop. In one embodiment of the method according to the inventio