DE102013002320A1 - Method for assisting driver of motor vehicle e.g. car after glare in traffic, involves performing adaptation of illumination of detected objects in specified brightness differences at specific time - Google Patents

Abstract

The method involves finding a glare for the driver and determining the blend parameter. The minimal perceptible contrast is determined at specific time after the transition based on the blend parameters and the objects in the surroundings of the vehicle and the object contrasts are determined. The required brightness difference of each detected object is determined from the object contrast and the minimum perceptible contrast. The adaptation of illumination of detected objects is performed in specified brightness differences at specific time. An independent claim is included for an apparatus for assisting driver of motor vehicle.

Description

The invention relates to a method for supporting a vehicle driver of a motor vehicle after dazzling in traffic according to the preamble of claim 1 and to a corresponding device according to the preamble of claim 7.

When driving at night, it may come to dazzle the driver due to the oncoming traffic due to, for example, not switched off high beam, incorrectly adjusted headlights or highly reflective objects. This leads to a partially severely limited perception of the driver, which continues beyond the actual glare. For example, the eyes need about 30 minutes to adjust from a brightly lit workroom to the nighttime darkness outdoors. If the driver is dazzled by an oncoming vehicle, the readaptation time of the driver is indeed reduced by the headlights present on his own vehicle, but the driver has the problem of adapting from light to dark and the driver's visual performance is restricted in accordance with the duration of the readaptation. As a result of glare, traffic safety is drastically reduced.

The publication EP 2 329 974 A1 describes a method and apparatus for reducing the glare of a driver of a first vehicle by an oncoming second vehicle on a night cruise. By means of a first sensor, locations of high luminance are determined and an optimal line of sight of the driver is determined, taking into account, on the one hand, the driver's glare is minimized and, on the other hand, the driver maintains an overview of the traffic situation. To indicate the driver the optimal viewing direction, this is indicated by an optical signal. However, the success of the procedure must be questioned if the driver's glare has already occurred.

In the publication DE 199 52 945 A1 For example, a method and system for eliminating glare from a person behind a pane is described, wherein the subject observes a scene in front of the pane through the pane. This is the case with the driver of a motor vehicle blinded by an oncoming vehicle during night driving through the windshield. In this case, the scene is detected in front of the window with the aid of an optical device and it is determined whether an object of the scene, ie the headlights of the oncoming vehicle, dazzling danger for the person behind the disc, ie the driver of the vehicle emanates. If this is the case, the passage of the blinding light through the disc with respect to the eyes of the observer is determined. Since the disc is formed such that its transparency is controllable, the light transmission is reduced for this area of the disc. Although a dazzling of a driver of a motor vehicle is avoided in this way by reducing the local transparency of the disc, but the constant change in the transparency of the disc could interfere on the one hand for the driver and on the other hand, the effort to be operated including the electronically controllable transparency of the disc high. If the driver is dazzled, the method can not provide assistance to the driver.

The invention is therefore based on the object to provide a method and an apparatus by means of which an already occurring dazzling effect counteracted with efficient measures and traffic safety can be increased.

This object is achieved by a method having the features of claim 1 and by an apparatus having the features of claim 7. Preferred embodiments of the invention are subject of the dependent claims.

• – Feststellung einer Blendung des Fahrers und Bestimmung der Blendparameter,
• – Bestimmung des minimal wahrnehmbaren Kontrasts zu einer Zeit t nach der Blendung basierend auf den Blendparametern,
• – Bestimmung von Objekten im Umfeld des Kraftfahrzeugs und deren Objektkontraste,
• – Bestimmung der notwendigen Helligkeitsdifferenz jedes detektierten Objekts aus den Objektkontrasten und des minimal wahrnehmbaren Kontrasts, und
• – Adaptierung der Ausleuchtung der detektierten Objekte an die bestimmten notwendigen Helligkeitsdifferenzen zum Zeitpunkt t.

The method according to the invention for assisting a driver of a motor vehicle after a dazzling of the driver comprises the steps:

• Determination of dazzling of the driver and determination of the glare parameters,
• Determination of the minimum perceivable contrast at a time t after the glare based on the glare parameters,
• Determination of objects in the environment of the motor vehicle and their object contrasts,
• Determining the necessary brightness difference of each detected object from the object contrasts and the minimum perceivable contrast, and
• - Adaptation of the illumination of the detected objects to the determined necessary brightness differences at the time t.

In other words, at any time t after the glare is determined glare determined depending on the determined glare parameters of the minimum perceptible brightness difference or contrast, from which the driver can perceive an object. On the basis of this contrast threshold, objects detected in the direction of travel for each time point during the readaptation of the driver in the vehicle environment are visualized by adapting the illumination of these objects to the current contrast threshold.

Preferably, the blend parameters include at least the glare duration, the glare intensity and the background brightness. The glare parameters are needed for the parametric determination of the minimum perceivable contrast at each time t after glare.

Preferably, only safety-critical objects are taken into account. In this way it is avoided that unnecessary objects are illuminated, which are unimportant for the driver in the current Verkahrssituation.

Preferably, the minimum perceivable contrast is determined from a contrast perception model based on the blend parameters. The model includes a plurality of curves that represent the temporal dependence of the minimum required brightness for illuminating an object, wherein the blend parameter parametrically defines the curve needed to determine the minimum perceivable contrast.

Preferably, the adaptation of the illumination of the detected objects is continued until the contrast perception of the driver is readapted again. Depending on the glare, this is approximately between 6 and 10 seconds, whereby a longer readaptation period is also possible.

More preferably, the entire surrounding scenery for the duration of the readaptation of the driver can be illuminated with a corresponding temporally adapted brightness, with detected oncoming traffic is left out.

• – eine Einrichtung zur Feststellung einer Blendung des Fahrers und zur Bestimmung der Blendungsparameter,
• – eine Einrichtung zur Bestimmung des minimal wahrnehmbaren Kontrasts zu einer Zeit t nach der Blendung basierend auf den Blendparametern,
• – eine Einrichtung zur Bestimmung von Objekten im Umfeld des Kraftfahrzeugs und deren Objektkontraste,
• – eine Einrichtung zur Bestimmung der notwendigen Helligkeitsdifferenz jedes detektierten Objekts aus den Objektkontrasten und des minimal wahrnehmbaren Kontrasts, und
• – eine Einrichtung zur Adaptierung der Ausleuchtung der detektierten Objekte an die bestimmten Helligkeitsdifferenzen zum Zeitpunkt t durch Ansteuerung der aktorikgesteuerten Scheinwerfereinrichtung.

The device according to the invention, which is designed to carry out the method described above, comprises a vehicle directional camera and an actuator-controlled headlamp device, the device further comprising:

• - a device to detect dazzling of the driver and to determine the glare parameters,
• A device for determining the minimum perceivable contrast at a time t after the glare based on the glare parameters,
• A device for determining objects in the vicinity of the motor vehicle and their object contrasts,
• A device for determining the necessary brightness difference of each detected object from the object contrasts and the minimum perceptible contrast, and
• - A device for adapting the illumination of the detected objects to the determined brightness differences at time t by controlling the actuator-controlled headlamp device.

The device for determining the minimum perceptible contrast preferably has a model for contrast perception based on the blend parameters.

By adapting the illumination of critical objects to a brightness level above the driver's current contrast threshold during the driver's readaptation time, whereby the illumination is continuously adapted to the time-varying contrast threshold, the traffic safety is greatly increased and the driver is in during the readaptation time the current traffic situation, so to speak no longer "blind".

A preferred embodiment of the invention will be explained below with reference to the drawings. It shows

1a - 1d the time course of a limited contrast perception during a driving situation, and

2 a schematic representation of the procedure.

In general, when driving at night it may come to dazzle the driver due to the oncoming traffic due to non-switched-off high beam, incorrectly adjusted headlights or highly reflective objects. This results in a partially severely limited perception of the driver, which continues beyond the actual glare, which drastically reduces traffic safety. Special driver support for glare does not currently take place.

If dazzling occurs on the road, this is supported during its readaptation phase after glare by additional marking of safety-critical objects and the negative influence of glare on perception and object recognition is reduced.

By a vehicle camera oncoming light sources are detected and their intensities and the ambient brightness determined. It is thus possible to record the time span and how much the driver is exposed to glare.

In the case of glare, the contrast perception of the driver is restricted, certain differences in brightness can no longer be perceived as such. Based on studies on readaptation duration, it can be quantified how long this perception restriction after the glare still lasts and which contrasts are recognizable to the driver at which time are. This knowledge about the current state of perception restriction of the vehicle driver can be used to continuously regulate the brightness of individual safety-critical objects.

The 1a to 1d show on the basis of an exemplary driving situation, the effect of dazzling a driver of a motor vehicle in a night driving, in which, for example, suddenly an oncoming vehicle turns up in a curve, this vehicle only fades by 1.5 seconds delayed, so that the driver of the ego vehicle for this duration is blinded. After dazzling, the driver is severely limited in his perception and has no way to detect, for example, a pedestrian appearing at the roadside at this moment or a traffic sign.

1a shows the contrast situation immediately after the dazzling of the driver, ie at the time t = 0. The contrast perception of the driver is greatly reduced, which is reflected in 1a expresses that, despite the usual illumination of lying in front of the vehicle of the vehicle lane 1 essentially only the marker 2 the right-hand side of the road, the middle mark 3 , the mark 4 the left-hand side of the road, and also the lower part of a right-hand roadway post due to the white color 5 and that of a left roadway post 6 can be seen. Everything else lies in the dark in the truest sense of the word due to the diminished vision due to the glare and the resulting lack of contrast perception for the driver. In the 1a areas represented by borders 7 and 8th represent places in the surrounding situation where critical objects are located for the driver, but which are currently not recognizable to the driver. So hides behind the area 7 a road sign above the road and behind the area 8th a pedestrian. In other words, the driver can not perceive critical objects such as a traffic sign and a pedestrian, because their object brightness does not stand out strong enough from the background.

As in 1b is shown, the contrast situation changes after one second, ie at time t = 1 s, only insignificantly. The contrast due to the illumination of the road 1 has increased somewhat, so that the edges of the road are slightly more prominent, but still are really only the right side lane marking 2 , the middle mark 3 , the left side marker 4 and the lower parts of the nearby right and left carriageway posts 5 . 6 to recognize. The in the fields 7 . 8th Safety-related critical objects Road signs and pedestrians are not visible for one second after glare because of the lack of contrast.

Only in 1c that the contrast situation for the driver 5 Seconds after the glare shows, the contrast has improved. The road edges with the right and left marks 2 . 4 , the middle mark 3 as well as the edge posts 5 and 6 stand out stronger, now including the top of the edge posts 5 . 6 can be seen. Furthermore, in the critical areas 7 . 8th now a traffic sign and a pedestrian visible. Also, now the left side is a sign 9 as well as the demarcation 10 between heaven 11 and landscape 12 recognizable. The rectangular area 13 on the right side of the road is to indicate a possible support of the driver by appropriately dynamically guided headlights, which additionally illuminate the driver's side roadway via a suitable adaptation without leading to dazzling oncoming traffic. However, such a measure does not have a targeted effect on critical objects.

1d shows the contrast situation 10 seconds after the glare. After 10 seconds, the driver has adjusted to the night driving situation with normal visibility and the contrasts are back in the usual range. In the critical areas 7 and 8th you can see the traffic sign and the pedestrian. Further, not only the demarcation 10 between heaven 11 and landscape 12 but there are also individual contours of trees 14 . 15 in the area of the landscape 12 out. The contrast perception has returned to the normal value after about 10 seconds, this value being only an example. Contrast perception may return to normal at an earlier time or at a later time, depending, for example, on the intensity of the glare.

To those in the 1a to 1d To defuse the critical situation presented, the assistance system intervenes, recognizing through the camera recordings both the previous glare from oncoming traffic and the pedestrian at the roadside and the traffic sign. The limited contrast sensitivity of the driver is continuously determined and compared with the measured brightness of the pedestrian and the traffic sign. In this situation, the pedestrian and the traffic sign is now lightened by additional actuators and thus visible to the driver again. He can now react accordingly and avoid an accident.

2 shows the sequence or the process control of the method for assisting a driver of a motor vehicle after a glare in a schematic representation. In a first step A presents a vehicle camera 20 detects a glare of the driver in the camera image and determines the glare intensity, the glare duration and the adaptation brightness. The time of the glare sets the time zero point of the procedure. The contrast perception ability of the driver is greatly reduced in the first two seconds after the glare, then gradually improves again and reaches the original value after approx. 6 to 10 seconds depending on the driver and glare.

In a second step B is by means of a model 21 for contrast perception and readaptation determines the minimum perceptible contrast that the driver can currently perceive t. In the model 21 for the perception of contrast curves are stored to the minimum required brightness MH for the perception of an object as a function of time t. As can be seen from the examples of the model, the minimum brightness required is small for small times and decreases at longer times. The time axis t of the model 21 Here, in the example, the unit has seconds, while the axis of the necessary minimum brightness has any units. The in the model 21 shown curves show a substantially exponential decrease in the minimum required brightness as a function of time, in other words, the driver's visibility readaptiert. The curves also depend parametrically on at least the glare intensity, the glare duration and the adaptation brightness. In other words, as a function of the camera 20 In the first step A measured parameter is selected a parametrically appropriate curve or function. From their time course, the minimum perceptible contrast to time t can be determined, which forms a contrast threshold at time t.

In a third step C, the camera detects 20 of the vehicle Objects in the camera image. The contrasts of the detected objects are determined and a list of the detected objects is created. For detected objects whose contrasts lie below the contrast threshold determined in step B, the brightness difference necessary to raise the contrast of the object to a value above the contrast threshold at time t is determined. From this comparison results whether the contrast of the detected object at time t after glare is sufficient to be perceived by the driver can. If highly reflective objects have been detected, which reflection may be caused by the vehicle headlamp, then these objects can be determined in the same way by which amount the brightness must be lowered in order to provide an acceptable contrast and reduce the strong reflection.

The brightness differences determined for the detected objects are converted in a control of the actuators of the headlights in order to adapt the illumination of the detected objects to the necessary contrast in a fourth step D. In other words, the lighting of the critical objects is adjusted so that the driver in his dazzling state can see the objects with sufficient contrast at time t. Due to the adapted brightness values, the scene is optimally illuminated by the ego headlights at this time t.

Since the readaptation of the driver changes continuously, as from the model 21 As can be seen, the adaptation of the brightness no longer fits at time t + 1 at time t. Therefore, at the next time t + 1, the method returns to step B and determines from the contrast perception model the minimum perceivable contrast at time t + 1, ie the contrast thresholds are again determined for the time t + 1 and an adaptation of the illumination by means of the steps C and D is performed. The procedure is terminated when the driver is readapted, usually after about 10 seconds.

• – registriert die Fahrzeugkamera eine Blendung durch den Gegenverkehr, wird der minimal wahrnehmbare Kontrast des Fahrzeugführers bestimmt,
• – für die Dauer der Readaptionsphase werden die Kamerabilder ausgewertet und sicherheitskritische Objekte detektiert, wie Fußgänger, Tiere, Schilder oder sonstige Hindernisse,
• – basierend auf den berechneten Kontrastschwellen können für den Fahrer derzeit nicht wahrnehmbare Objekte zusätzlich aufgehellt und so erkennbar gemacht werden,
• – umgekehrt kann bei Eigenblendung durch starke Reflektionen punktuell die Scheinwerferhelligkeit reduziert und so eine weitere Blendung vermieden werden, so dass abhängig von den ermittelten Kontrastschwellen eine Sichtbarkeit des reflektierenden Objektes weiterhin sichergestellt wird.

In summary, objects below the threshold of perception are lightened adaptively, and strongly reflecting surfaces are partially dimmed according to the following scheme:

• If the vehicle camera registers glare due to oncoming traffic, the driver's minimum perceivable contrast is determined,
• - For the duration of the readaptation phase, the camera images are evaluated and safety-critical objects are detected, such as pedestrians, animals, signs or other obstacles,
• Based on the calculated contrast thresholds, objects which are currently imperceptible to the driver can be additionally lightened and thus made recognizable,
• - Conversely, when self-glare by strong reflections selectively reduced the headlight brightness and so a further glare can be avoided, so that depending on the determined contrast thresholds visibility of the reflective object is still ensured.

Since, as already described, currently driver are not supported in the event of dazzling by oncoming traffic separately, the advantage of the system described is the reduction of glare on the perception of the driver and thus in minimizing the risk of glare security. Visibility of critical objects after glare is ensured, allowing the driver to react accordingly.

LIST OF REFERENCE NUMBERS

1

roadway

2

Marking on the right

3

center mark

4

Mark left

5

Post right

6

Post left

7

Area road sign

8th

Pedestrian area

9

Information sign curve

10

demarcation

11

sky

12

landscape

13

additional illumination

14

tree silhouette

15

tree silhouette

20

camera

21

Model for contrast perception

22

adaptable headlight

A

first process step

B

second process step

C

third process step

D

fourth process step

MH

minimum required brightness for the perception of an object

t

time in seconds

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 2329974 A1 [0003]
• DE 19952945 A1 [0004]

Claims (8)

Method for assisting a driver of a motor vehicle after a dazzling of the driver, characterized by the steps: Determination of glare of the driver and determination of the glare parameters, Determining the minimum perceivable contrast at a time t after glare based on the glare parameters Determination of objects in the environment of the motor vehicle and their object contrasts, Determining the necessary brightness difference of each detected object from the object contrasts and the minimum perceivable contrast, and Adaptation of the illumination of the detected objects to the determined brightness differences at time t. A method according to claim 1, characterized in that the blend parameters include at least the glare duration, the glare intensity and the background brightness. Method according to one of the preceding claims, characterized in that only safety-critical objects are taken into account. Method according to one of the preceding claims, characterized in that the minimum perceptible contrast is determined from a model for contrast perception based on the blend parameters. Method according to one of the preceding claims, that the adaptation of the illumination of the detected objects is continued until the contrast perception of the driver is readapted again. Method according to one of the preceding claims, characterized in that the entire surrounding scenery is illuminated for the duration of the readaptation of the driver with a correspondingly temporally adapted brightness, with detected oncoming traffic being omitted. Device designed to carry out the method according to one of the preceding claims with a vehicle camera oriented in the direction of travel ( 20 ) and an actuator-controlled headlamp device ( 22 ), characterized in that the apparatus further comprises means for detecting dazzling of the driver and for determining dazzling parameters, means for determining the minimum perceivable contrast at a time t after glaring based on the glare parameters means for determining objects in the vicinity of the motor vehicle and its object contrasts, a device for determining the necessary brightness difference of each detected object from the object contrasts and the minimum perceptible contrast, and means for adapting the illumination of the detected objects to the determined brightness differences at time t by driving the actuator-controlled headlamp device ( 22 ). Device according to Claim 7, characterized in that the device for determining the minimum perceivable contrast comprises a model ( 21 ) for contrast perception based on the blend parameters.

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