DE102019008083A1 - Method for determining a fog density - Google Patents

Abstract

The invention relates to a method for determining a fog density in the surroundings of a vehicle (1) with at least one camera (3), the captured camera images being compared with information stored in a digital map. According to the invention it is provided that positions of light sources (L) present in the current surroundings of the vehicle (1) as well as their light intensity and size are stored in the digital map and halo effects of existing light sources (L) present in the camera images are taken into account whose light intensity and size are evaluated to determine the fog density.

Description

The invention relates to a method for determining a fog density in the surroundings of a vehicle with at least one camera, with captured camera images being compared with information stored in a digital map.

From the DE 10 2017 000 753 A1 a method for detecting moisture in a vehicle environment is known. In this case, at least one distance to objects in the vicinity of the vehicle is determined by means of at least one sensor unit arranged in and / or on the vehicle. In addition, a comparison of the recorded optical sensor data with the optical data of the objects stored in a digital map is carried out automatically.

The invention is based on the object of specifying a method, which is improved over the prior art, for determining a fog density in the surroundings of a vehicle.

The object is achieved according to the invention with a method which has the features specified in claim 1.

Advantageous embodiments of the invention are the subject of the subclaims.

A method for determining a fog density in the surroundings of a vehicle with at least one camera provides that captured camera images are compared with information stored in a digital map. According to the invention, positions of light sources present in the current surroundings of the vehicle as well as their light intensity and size are stored in the digital map and halo effects of existing light sources present in the camera images are evaluated to determine the fog density, taking into account their light intensity and size.

By using the method, the fog density can be determined comparatively easily and without additional components. To carry out the method, information is used that is required for autonomous driving of the vehicle, so that it is available to the vehicle if it has a device for autonomous driving.

If a relatively high fog density is determined, the autonomously driving vehicle can be put into a safe vehicle standstill, which can also be referred to as a state of rest, before the functionality of vehicle-side sensors is disturbed due to the fog density and problems can be caused as a result.

Based on the determined fog density, other sensors built into the vehicle, for example a lidar-based sensor and / or an active camera, can be optimally parameterized for changed weather conditions, e.g. B. in relation to an adaptation of a lighting power and / or a sensor noise level to the fog density, which enables a comparatively stable performance of these sensors with a low to moderately high fog density. The initiation of a safe vehicle standstill can thus be avoided in the case of low to moderately strong fog density and the safe vehicle standstill only in the case of significantly stronger fog, i.e. H. at a significantly higher fog density. Furthermore, in the case of a comparatively heavy fog, additional noises can be emitted by the vehicle in order to warn other road users about the approaching vehicle.

Embodiments of the invention are explained in more detail below with reference to a drawing.

• 1 schematisch ein in einem Nebelgebiet fahrendes Fahrzeug und eine Lichtsignalanlage.

The shows:

• 1 schematically a vehicle driving in a foggy area and a traffic light system.

The only figure shows one in a foggy area N moving vehicle 1 , which is moved in autonomous driving mode, and a traffic light system 2 , ie a traffic light. When driving through such a foggy area N there is a risk that a view of both detection units of a vehicle-side environmental sensor system and that of human eyes is restricted.

The foggy area N has a certain fog density, whereby by determining the fog density and thus by knowing the fog density, vehicle-side sensors can be adapted to the prevailing conditions, in particular to the adverse visibility conditions, or the vehicle 1 is automatically transferred to a safe vehicle standstill in the event of a relatively high fog density.

To ensure safe driving of the vehicle 1 To be able to ensure as far as possible in fog, a method described below for determining a fog density is provided, the determination with one in the vehicle 1 existing infrastructure.

In the vehicle 1 A digital map, in particular a so-called high-precision HD map, is stored on the basis of which, in conjunction with recorded signals from a position determination unit, a current position of the vehicle is determined 1 is captured.

In addition, there are light sources in the digital map L. , especially traffic lights 2 and lanterns, as well as their respective light intensity and size are stored. Thus it can be determined which light sources L. in a current environment of the vehicle 1 are located.

The vehicle also has 1 via a camera 3 that is part of the environmental sensor system and its detection area in front of the vehicle 1 is directed.

Depending on the prevailing fog density of the respective fog area N form light sources L. in recorded camera images of the camera 3 differently pronounced halo effects, the fog density increasing with the size of a halo. I.e. the greater the halo effect, the higher the fog density.

Based on the knowledge of the position of the traffic light system 2 , its light intensity and size as well as additional meta information, if necessary, can use the camera images to determine the fog density of the fog area present N to be determined.

The fog density determined in this way can, in particular, be used as a basis for the autonomous driving operation and used to set parameters of the detection units of the environmental sensor system, in particular with regard to lighting power and sensor noise. In addition, a noise level of noises emitted when driving can be adapted with regard to the fog density, so that the vehicle 1 can be recognized when approaching other road users. In particular, the noise level increases with increasing fog density, since visibility and the vehicle are reduced 1 thus represents an increased risk for road users, in particular for unprotected pedestrians and cyclists.

List of reference symbols

1

vehicle

2

Traffic lights

3

camera

L.

Light source

N

Foggy area

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was 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.

Patent literature cited

• DE 102017000753 A1 [0002]

Claims (2)

Method for determining a fog density in the surroundings of a vehicle (1) with at least one camera (3), wherein captured camera images are compared with information stored in a digital map, characterized in that - in the digital map positions of in the current surroundings of the Vehicle (1) existing light sources (L) as well as their light intensity and size are stored and - Halo effects of existing light sources (L) in the camera images are evaluated, taking into account their light intensity and size to determine the fog density. Procedure according to Claim 1 , characterized in that at least light signal systems (2) and lanterns are stored in the digital map as light sources (L).

Images