WO2014032933A1

WO2014032933A1 - Method for operating a vehicle

Info

Publication number: WO2014032933A1
Application number: PCT/EP2013/066649
Authority: WO
Inventors: Steffen HÄDRICH
Original assignee: Bayerische Motoren Werke Aktiengesellschaft
Priority date: 2012-08-29
Filing date: 2013-08-08
Publication date: 2014-03-06
Also published as: DE102012215287A1

Abstract

Disclosed is a method and a corresponding device for operating a vehicle, to which vehicle at least one camera is assigned, in which method an image data set (DATA) is produced that is assigned to an image recorded by the camera. On the basis of the image data set (DATA), a first measurement signal (R_SIG) is detected which represents the brightness of the light that reaches the vehicle from the outside relative to the vehicle. Alternatively or additionally, and on the basis of the image data set (DATA), a second measurement signal is detected which represents a state of rain outside the vehicle.

Description

description

Method for operating a vehicle

The invention relates to a method for operating a vehicle, which has at least one camera.

Modern vehicles often have a camera that is used by driver assistance systems. For example, cameras are often used for a parking aid, a lane recognition or a distance assistant.

In addition, a rain sensor is often installed in vehicles, which detects rain. By means of the rain sensor, for example, an automatic windscreen wiper control can be realized.

It is also often used for example for an automatic

Dipped beam control installed a light sensor in vehicles. The light sensor detects the brightness that hits the light sensor from the outside.

The object on which the invention is based, it is according to a first aspect of a method or a

To provide a device for operating a vehicle to easily determine a first measurement signal that is representative of the brightness incident on the vehicle from the outside of the vehicle and according to a second aspect to provide a method and a device for Operating a vehicle to easily determine a second measurement signal that is representative of a rain condition outside of the vehicle. The object is solved by the features of the independent claims. Advantageous embodiments are characterized in the subclaims.

The invention is characterized according to a first aspect by a method or by a

corresponding device for operating a vehicle. The vehicle has at least one camera. An image data set associated with an image captured by the camera is provided. Depending on that

Image data set, a first measurement signal is determined, which is representative of the brightness of the light incident with respect to the vehicle from the outside of the vehicle.

In this way it is possible to use a camera as a light sensor. It may be possible to dispense with a light sensor. In addition, as a camera can be used for a different purpose, such as

Example for lane detection, pedestrian protection or

Standstill warning anyway exists. The light sensor can be realized with the vehicle camera, this saves

possibly costs and installation space.

According to an advantageous embodiment, the first

Measurement signal determined depending on at least one manipulated variable and / or at least one characteristic of the camera.

By using at least one manipulated variable and / or a parameter of the camera for determining the first measuring signal, the brightness can optionally be determined more robustly and / or with less computational effort. According to a further advantageous embodiment

depending on the first measurement signal a tunnel entrance and / or a tunnel exit detected.

By a quick detection of the tunnel entrance and / or the tunnel exit, it is possible, for example, the

Turn on vehicle light in the tunnel.

According to a further advantageous embodiment

depending on the first measurement signal, a day / night state and / or a twilight state detected.

According to a further advantageous embodiment

depending on the first measurement signal, a control signal

provided. The control signal is provided for activating a day display view or a night display view of a display device and / or for

Enable or disable at least one

Vehicle headlights.

By providing a control signal, it is possible without much effort, the display device and / or

To control vehicle headlights.

According to a further advantageous embodiment, the first measurement signal is filtered. By filtering can

Disturbances of the measuring signal are suppressed. So can

for example, a sudden brightness

filtered out, for example, from the headlights of an oncoming vehicle.

According to a second aspect, the invention is characterized by a method or by a corresponding device for operating a vehicle having at least one camera. It will be a

An image data set associated with an image captured by the camera. Depending on that

Image data set, a second measurement signal is determined, which is representative of a rain condition outside the

Vehicle.

In this way, it is possible to use a camera as a rain sensor. It may be possible to dispense with a rain sensor. In addition, as a camera can be used for a different purpose, such as

Example for lane detection, pedestrian protection or

Distance warning exists anyway. The rain sensor can be realized with the vehicle camera, this saves

possibly costs and installation space.

According to a further advantageous embodiment, spatial frequencies of the image are determined as a function of the image data record. Depending on the determined spatial frequencies of the image, the second measurement signal is determined. By evaluating the spatial frequencies can with little computational effort

Conclusions about the state of rain can be drawn.

According to a further advantageous embodiment, a sequence of image data sets is provided. The respective image data set is a respective image of a

assigned sequence associated with images. Depending on the respective image data set of a respective image of the sequence of images, respective spatial frequencies of the respective image are determined. Depending on the spatial frequencies of the

each image is a characteristic value determined, the

It is characteristic for the sharpness of the respective picture. Depending on the determined characteristic values of the respective images, a sharpness profile of the sequence of the images is determined. Depending on the sharpness, the second measurement signal is determined.

By observing the sharpness course, the rain condition is determined more reliably if necessary.

According to a further advantageous embodiment, an image area is determined depending on the spatial frequencies of the respective images, in which the spatial frequencies change strength than in other image areas. Depending on the spatial frequencies of the image area, the respective characteristic value of the image is determined.

Due to the limitation of the image area, the

Computing costs are reduced.

According to a further advantageous embodiment, the camera is designed as a stereo camera. Depending on that

Image data set is determined by depth information that is characteristic of a distance of individual points of objects that are shown on the image.

Depending on the depth information, the second will be

Measurement signal determined.

If a stereo camera is installed in the vehicle, the depth information can be used to determine the rain condition more robust and possibly with less computational effort.

According to a further advantageous embodiment, the camera is a front camera of the vehicle. With If necessary, raindrops can be detected on the windshield of a front camera.

The first aspect and its configurations can be arbitrarily combined with the second aspect and its embodiments,

Embodiments of the invention are explained in more detail below with reference to the schematic drawings. Show it:

FIG. 1 shows a vehicle,

FIG. 2 shows a first flow chart,

3 shows a second flowchart.

Elements of the same construction or function are

cross-figures with the same reference numbers

marked.

A vehicle 1 (FIG. 1) has at least one camera KAM. The camera KAM is designed and arranged to detect at least a portion of the surroundings of the vehicle 1. The camera KAM can also be designed as a stereo camera. The camera KAM is arranged, for example, at the front of the vehicle 1.

The vehicle 1 further has a control unit SE, which is signal-technically coupled to the camera KAM in such a way that it stores an image data record DATA and / or a sequence of

Image data sets DATAS from the camera KAM can receive.

The control unit SE has a data and program memory and also has a computing unit in which programs are executed during operation of the vehicle 1. In addition, the control unit SE preferably has an output interface via which it is signal-wise coupled, for example with a display device KOM.

The display device KOM is for example

designed to provide a tag display view or a night view view.

The control device is for example alternatively or additionally coupled with at least one vehicle headlight SW1 and / or a second vehicle headlight SW2 and / or further vehicle headlights signal technology. For example, the controller may activate and

Deactivate daytime running lights and / or dipped headlights and / or control high beam.

A first program, which is executed in the control unit SE, is started in a step S1 (FIG. 2), in which variables can be initialized if necessary.

In a step S3, the image data set DATA

provided associated with an image captured by the camera KAM. The image data set DATA comprises Image information and / or camera information. The

Image information includes, for example, pixel values for pixels of the image, such as color values or gray levels of the pixels. The camera information has, for example, control variables and / or characteristics of the camera. You have, for example, the exposure time and / or the

Photosensitivity and / or a f-number and / or saturation.

In a step S5, depending on the image data record DATA, a first measurement signal INT is determined, which is representative of the brightness of the light which occurs with respect to the vehicle 1 from the outside on the vehicle 1. So can one

Tunnel entrance and / or a tunnel exit and / or a day / night state and / or a twilight state are detected depending on the first measurement signal INT.

For example, from the image information of the

Image data set DATA the pixel values directly evaluated and possibly taking into account one or more control variables and / or one or more characteristics of the camera KAM, such as the exposure time, the first measurement signal INT is determined.

Alternatively or additionally, pixel values of the image which are present, for example, in the R / G / B color space, can be converted into the Y / Cb / Cr color space. With an evaluation of the

Basic brightness values (Y) of the pixels and optionally taking into account at least one control variable and / or at least one characteristic of the camera KAM, such as the sensitivity of the sensor chip of the camera KAM and / or the exposure time, for example, then the first

Measurement signal INT are determined. The pixel values can also be converted into another color space or directly into a gray value representing the brightness. By evaluating these converted pixel values, it may be possible, taking into account at least one control variable and / or at least one

Parameter such as the exposure time and / or the sensitivity of the sensor chip of the camera KAM

For example, then the first measurement signal INT are determined.

Alternatively, it is also possible if the pixel values have no color information but only gray values, depending on an evaluation of the gray values and optionally taking into account at least one control variable and / or at least one characteristic such as, for example

Exposure time and / or the sensitivity of the sensor chip of the camera CAM to determine the first measurement signal INT, since the gray value reflects the brightness of the pixel.

For example, it is alternatively or additionally possible to determine the first measurement signal as a function of the saturation of the sensor chip of the camera KAM and of the exposure time.

For example, in a dark environment, the sensor chip of the camera KAM has a low saturation despite being long

Shutter speed up.

In an optional step S7, the first measurement signal INT is filtered. The first measurement signal INT is, for example, by means of a moving average filter and / or a

Low pass filter filtered. Filtering can be used to filter faults. For example, if a vehicle with bright spotlights, this sudden change in brightness is filtered out.

In a step S9, a control signal S_SIG is provided depending on the first measurement signal INT and / or depending on the filtered first measurement signal. The control signal S_SIG is provided, for example, for activating the day display view or the night display view of

Display device KOM and / or to the active or

Deactivating at least one vehicle headlight SW1.

After the step S9, the first program is terminated in a step Sil and can optionally be started again in step S1.

A second program, in the control unit SE

is executed, is started in a step S21 (Figure 3), in which variables can be initialized if necessary.

In a step S23, the image data set DATA

provided associated with an image captured by the camera KAM. Additionally or alternatively, a sequence of image data records DATAS can be provided, wherein the respective image data record DATA is assigned to a respective image from an associated sequence of images. The sequence of images can be a sequence of directly temporally successive images. The sequence of pictures can also be pictures in a given temporal

Have distance.

In an optional step S25, depending on the

Image data set DATA spatial frequencies FRQ of the image determined. In order to determine the spatial frequencies FRQ, for example, the pixel values of the image or pixel values of partial areas of the image are transformed into another color space, for example, if the pixel values are present in the R / G / B color space, in the Y / Cb / Cr color space. After

Color transformation, for example, the rows and / or the columns of the basic brightness values (Y) of the pixels are transformed into the frequency domain, for example by means of a Discrete Cosine Transform (DCT) or a Discrete Sine Transform (DST) or a Discrete

Fourier transformation (DFT) or fast

Fourier transformation (FFT). The frequency transformation can also make sense with pixel values from any the expert

appear color space may be performed, optionally without color transformation or optionally from gray values. From the frequency transformation, the spatial frequencies FRQ appearing in the image or in the image part can be obtained

remove .

From the spatial frequencies FRQ can close on the sharpness of the image, because sharp edges in the rows or columns in an image have high spatial frequencies FRQ on. From the sharpness in turn can draw conclusions about a

Rain condition are drawn because the more blurred the picture is, the more likely it is raining.

The more high spatial frequencies FRQ appear in the image, the more likely it is that the image is sharp. But it can also be that with a monotonous picture no high

Spatial frequencies occur FRQ and the image is still sharp because the image has no or only a few edges in the rows or columns. This can be the case, for example, if a road or the sky is depicted. Therefore Often it makes sense to consider a sharpness progression SH of a sequence of images, as in steps S27 to S29.

In the optional step S27, depending on the

respective image data set DATA, to which a respective image is assigned to a sequence of images, determines respective spatial frequencies FRQ of the respective image. Depending on the

Spaces FRQ of each image is determined in each case a characteristic KW, which is characteristic of the

Sharpness of the respective picture.

Depending on the spatial frequencies FRQ of the respective image, in addition to or as an alternative to step S27, an image region is determined in step S28 in which the spatial frequencies FRQ change more than in other image regions.

Subsequently, the parameter KW is determined depending on the Orsfrequenzen FRQ of the image area. This minimizes the amount of computation required, as only one image area or a so-called "region of interest" (ROI) is considered for the calculations, for example, the area is mapped to the street in an area of the image another area the environment

Considering the sharpness, it may now be useful not to look at the road, for example, this image area for the calculation of the characteristic KW does not

considered .

In step S29, the sharpness profile SH is dependent on those determined in step S27 and / or step S28

Characteristic values KW of the respective images. This allows a conclusion to be drawn on a rain condition. If the sharpness drops in the sharpness progression SH, then it is probable that it rains. If the sharpness increases, so it is

probably that the rain wears off.

In a step S31, a second measurement signal R_SIG is determined. The second measurement signal R_SIG is determined, for example, as a function of the sharpness profile SH ascertained in step S29 and / or dependent on those in step S25

determined spatial frequencies FRQ of the image. The second

Measurement signal R_SIG can also alternatively or additionally

are determined from depth information that

characteristic of the removal of points from objects depicted in the picture. The

Depth information, for example, from the

Image data set DATA determined, if the camera KAM is a stereo camera. For example, a so-called disparity map is determined from the image data set DATA. The disparity map assigns a distance value to each pixel of the image that maps a point of an object. On the disparity card are, for example, the

Raindrops on the windshield as faults

identifiable. It is not just the condition that it rains that can be determined, but also the intensity, for example, by counting the raindrops.

The second measurement signal R_SIG is representative of one

Rain condition outside the vehicle 1. Thus, depending on the second measurement signal R_SIG can be determined whether it is raining, in addition or alternatively, but also the intensity of the rain can be determined. It can be an alternative to a

Rain sensor already installed in the vehicle 1 Camera KAM be used to detect rain for example

To control windscreen wipers of the vehicle 1. In a step S33, the second program is ended and may optionally be restarted in step S21.

The second measurement signal R_SIG can be additionally or alternately determined depending on a detection of

Light sources. If the light sources are distorted in the picture, or if their uniform! Tat is disturbed, then conclusions can be drawn regarding a state of rain and a

Rain intensity can be obtained.

The second measurement signal R_SIG can additionally or alternatively be determined depending on predetermined edge shapes and / or reflections. Run detected edges, for example, from vehicles ahead, not how

given, conclusions can be drawn from it on a rain condition and a rain intensity. Additionally or alternatively, reflections, for example, reflections of the sky on a wet roadway can be detected and from this conclusions about the rain condition can be determined.

List of reference numbers:

1 vehicle

SE control unit

KOM display device

Came camera

SW1, SW2 vehicle headlights

DATA image data set

DATAS sequence of image records

INT first measurement signal

S_SIG control signal

R_SIG second measuring signal

SH sharpness course

FRQ spatial frequency

KW characteristic value

Claims

claims

A method of operating a vehicle (1)

at least one camera (KAM), in which

- An image data set (DATA) is assigned, which is associated with an image, which is detected by the camera (KAM) and

- Depending on the image data set (DATA), a first measurement signal (INT) is determined, which is representative of the

Brightness of the light impinging on the vehicle (1) from the outside with respect to the vehicle (1).

2. The method of claim 1, wherein the first measurement signal (INT) depending on at least one control variable and / or at least one characteristic of the camera (KAM) is determined.

3. The method according to claim 1 or 2, wherein a

Tunnel entrance and / or a tunnel exit is detected depending on the first measurement signal (INT).

4. The method according to any one of the preceding claims, in which a day / night state and / or a twilight state is detected depending on the first measurement signal (INT).

5. The method according to any one of the preceding claims, wherein depending on the first measurement signal (INT), a control signal S_SIG is provided for activating a day display view or a night display view of a

Display device (KOM) and / or to activate or

Deactivating at least one vehicle headlight (S 1).

6. The method according to any one of the preceding claims, wherein the first measurement signal (INT) is filtered.

7. A method for operating a vehicle (1) having at least one camera (KAM), in which - An image data set (DATA) is assigned, which is associated with an image, which is detected by the camera (KAM) and

- Depending on the image data set (DATA) a second

Measuring signal (R_SIG) is representative, which is representative of a rain condition outside the vehicle (1).

8. The method according to claim 7, wherein depending on the

Image data set (DATA) spatial frequencies (FRQ) of the image

be determined and depending on the determined

Local frequencies (FRQ) of the image, the second measurement signal (R_SIG) is determined.

9. The method according to claim 7 or 8, wherein

- A sequence of image sets (DATAS) is provided, wherein the respective image data set (DATA) a

associated with each image from an associated sequence of images,

- Depending on the respective image data set (DATA) of a respective image of the sequence of images respectively

Spatial frequencies (FRQ) of the respective image are determined

- Depending on the spatial frequencies (FRQ) of the respective image in each case a characteristic value (KW) is determined, the

characteristic of the sharpness of the respective image,

- A sharpness profile (SH) of the sequence of images depending on the determined characteristic values (KW) of the respective images

is determined and

the second measuring signal (R_SIG) depends on the

Sharpness is determined.

10. The method according to claim 9, wherein depending on the

Local frequencies (FRQ) of the respective images an image area is determined in which the spatial frequencies (FRQ) change more than in other image areas and depending on the spatial frequencies (FRQ) of the image area of the respective characteristic value of the image is determined.

11. The method according to claim 7-10, wherein

- the camera (KAM) is designed as a stereo camera,

depending on the image data set (DATA), depth information is determined that is characteristic for the

Removal of points from objects in the picture

are shown and

- Depending on the depth information, the second measurement signal (R_SIG) is determined.

12. The method according to any one of the preceding claims, wherein the camera (KAM) is a front camera of the vehicle (1).

13. A device for operating a vehicle (1), wherein the device is adapted to perform a method according to one of claims 1 to 12.