KR20190028950A - Diagnosys method for the fault of lamp of a car using a camera - Google Patents

Abstract

The present invention relates to a fault diagnosis method for a vehicle lamp using a camera and, more specifically, to a fault diagnosis method for a vehicle lamp, which can perform fault diagnosis with respect to lamp burnout in accordance with brightness of an image frame photographed by using images of a front camera or a rear camera in a vehicle.

Description

[0001] The present invention relates to a method of diagnosing a lamp failure in an automobile using a camera,

The present invention relates to a method of diagnosing a lamp failure in an automobile using an image capturing apparatus, and more particularly, to a method of diagnosing whether a lamp is broken or not according to the brightness of an image frame photographed using a front camera or a rear camera image A method for diagnosing a lamp failure in a vehicle is disclosed.

In general, automobiles are provided with lamps such as headlights, taillights, turn signals, etc., to ensure the visibility of the vehicle during day and night driving, and display lane change or direction change.

However, in the case where a lamp that provides an important function of the automobile has a failure as described above, conventionally, in order to check whether the lamp is open, a current applied to each lamp is sensed through a sensor, and SJB (Electronic control unit) of an automobile through a junction box (fuse and relay integrated box) or an IBU (integrated body unit) to determine whether or not the vehicle is disconnected. A warning pop-up, and the like. In the case of the turn signal lamp, the driving cycle of the direction indicator is rapidly blinked on the cluster to warn the driver.

Therefore, in order to determine whether the lamp is broken, the conventional lamp disconnection diagnostic method has a disadvantage in that a manufacturing cost is separately required because a current sensor for measuring the current applied to the lamp and an additional circuit according to the sensor are mounted.

In addition, the conventional lamp disconnection diagnostic method has a problem in that it is not possible to detect degradation of the lamp performance due to low luminance emission due to degradation of lamp life or leakage of light emitting gas in the lamp.

The present invention provides a method of diagnosing a lamp failure in a vehicle using a camera capable of diagnosing whether or not a lamp is disconnected by using a front camera or a rear camera image in an automobile, the method being provided to solve the above- The present invention has been made in view of the above problems.

According to another aspect of the present invention, there is provided a method of diagnosing a lamp failure of an automobile using an image taking apparatus, the method comprising: diagnosing whether a lamp is broken or not according to brightness of an image frame photographed using a front camera or a rear camera image; / RTI >

The method for diagnosing a lamp failure of an automobile using the camera of the present invention having the above-described configuration can diagnose whether a lamp is broken or not by using a front camera or a rear camera image in an automobile, It is possible to detect the deterioration of the lamp performance due to leakage of the luminescent gas inside the lamp or the like.

In addition, although a current sensing circuit or a sensor circuit is used to detect whether a lamp is broken, the present invention can detect whether the lamp is broken or deteriorated by using a camera image, And can perform excellent disconnection detection.

In addition, since it is unnecessary to mount a current sensing circuit or a sensor circuit for detecting whether a lamp is disconnected, it is a very advanced invention that can reduce manufacturing cost.

1 is a block diagram of a lamp failure diagnosis system of the present invention,
2 is a view showing emitted light of a light source emitter of a vehicle equipped with a lamp failure diagnosis system of the present invention,
3 is a flow chart of the lamp failure diagnosis method of the present invention,
4 is a view showing an image frame image of the lamp failure diagnosis method of the present invention,
5 is a diagram showing a divided area of the lamp failure diagnosis method of the present invention,
6 is a diagram showing a region of interest of the lamp failure diagnosis method of the present invention,
7 is a graph showing a contrast ratio of a data scan line of the lamp failure diagnosis method of the present invention,
8 is an example of a warning display of the lamp failure diagnosis method of the present invention,
FIGS. 9 and 10 show an example of a geometric graph showing the luminance output capability of a light source of a lamp in the lamp failure diagnosis method of the present invention.

Hereinafter, the configuration and operation of a lamp failure diagnosis method for a vehicle using the camera of the present invention will be described with reference to the drawings.

It is to be noted, however, that the disclosed drawings are provided as examples for allowing a person skilled in the art to sufficiently convey the spirit of the present invention. Accordingly, the present invention is not limited to the following drawings, but may be embodied in other forms.

In addition, unless otherwise defined, the terms used in the description of the present invention have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. In the following description and the accompanying drawings, A detailed description of known functions and configurations that may be unnecessarily blurred is omitted.

1 is a block diagram of a system in which the lamp failure diagnosis method of the present invention is performed.

The system in which the lamp failure diagnosis method of the present invention is performed can diagnose whether or not the lamp is disconnected by using the camera 10 such as a multi function camera (MFC) that shoots the front or rear of the automobile and generates an image signal .

To this end, as shown in FIG. 1, a system in which the lamp failure diagnosis method of the present invention is performed includes a camera 10 installed in a vehicle and photographing the front or rear of the vehicle; A video signal input unit 20 for receiving an image signal generated by the photographing apparatus 10 and converting the image signal into a digital signal to generate an image frame at a predetermined time interval; A fault diagnosis unit (30) for receiving a video frame from the video signal input unit (20) and determining whether the automobile lamp is faulty through brightness analysis of the video; And a warning display unit (40) for displaying a failure of the lamp in the cluster (50) of the vehicle according to a result of the determination by the failure diagnosis unit (30).

FIG. 2 is a view showing an area of light emitted from a lamp of a vehicle to which the lamp failure diagnosis method of the present invention can be applied, and a sensing area of the photographing apparatus.

Referring to the drawings, first, the sensing area of the camera 10 is installed in a car C, and the front camera sensing area A1 of the photographing device 10 photographing the front side and the back camera 9 of the photographing device 10 photographing the rear side There is a sensing area A2.

In addition, there are an area B1 of the headlight emitted from the headlight of the automobile and an area B2 of the backlight of the automotive vehicle.

In addition, there are an area D1 where the light emitted from the forward direction indicator of the automobile is incident and an area D2 where the light emitted from the rearward direction indicator light is reflected.

Therefore, the front camera sensing area A1 and the rear camera sensing area A2 of the photographing machine 10 of the lamp failure diagnosis system of the present invention can take at least the headlight output light area B1 and the rear light output area B2 It is desirable to have a sensing area that is large enough to allow the sensing area.

In addition, it is preferable that the photographing device 10 is a conventional digital camera.

3 is a flowchart of a lamp failure diagnosis method of the present invention.

A method for diagnosing a lamp failure according to an embodiment of the present invention includes an image frame generation procedure for receiving an image signal generated by an image capturing apparatus installed in an automobile and photographing the front or rear of an automobile and converting the image signal into a digital signal, And a failure diagnostic procedure for receiving the image frame and determining whether the lamp of the automobile is broken through the brightness analysis of the image.

In addition, the lamp failure diagnosis method of the present invention having the above-described procedure comprises: a photographing machine 10 installed in an automobile and photographing the front or rear of the automobile; A video signal input unit 20 for receiving an image signal photographed by the photographing apparatus 10 and generating an image frame at a predetermined time interval; A fault diagnosis unit (30) for receiving a video frame from the video signal input unit (20) and determining whether the automobile lamp is faulty through brightness analysis of the video; And a warning display unit (40) for displaying a failure of the lamp in a cluster (50) of the vehicle according to a result of the determination by the failure diagnosis unit (30).

Referring to the drawing, the image frame generation procedure is a procedure in which a video signal of an outgoing light region of a lamp in front of or behind a vehicle taken by the camera 10 is input to the video signal input unit 20, (S10), and the transformed image frames are transmitted to the fault diagnosis unit 30. [0033]

Next, the above-described failure diagnosis procedure comprises steps S20 to S100, which will be described in detail below.

First, the failure diagnosis unit 30 measures a contrast ratio for each input image frame (S20).

Preferably, according to the 'Simple Contrast' method of dividing the maximum luminance of the image frame by the minimum luminance for each image frame of the present invention, the contrast ratio for each image frame is measured using Equation 1 below.

(1)

C / R (contrast ratio) = Ymax / Ymin

* Ymax: maximum luminance (white luminance)

  Ymin: minimum luminance (black luminance)

For example, if the white luminance of the image frame received from the camera 10 by the output of the headlight is 100.0 cd / m ² and the luminance of black is 1.0 cd / m ² , the contrast ratio (C / R) of the image frame is 100.0 / 1.0 = 100. The calculated contrast ratio of the image frame has a meaning of the detection resolution of the image frame image of the photographing device 10.

Here, the luminance represents the brightness of the light emitted from the light source, and the luminance is a value defined by the luminous intensity per area projected on the plane light source, the reflection plane, and the plane perpendicular to the viewing direction from the transmission plane. cd / m ² (nit).

Illuminance is the brightness of an object receiving light from a light source, which is defined as the amount of light reaching a unit area, and the unit is lux or lx.

FIG. 4 shows an example of a gray scale (gray scale) of an image frame input by the image capturing apparatus 10. As described above, according to the simple contrast method, the white luminance of Ymax of the corresponding image frame Brightness) and the black luminance of Ymin (i.e., the minimum luminance) are calculated to calculate the contrast ratio C / R.

Next, if the contrast ratio is calculated for each corresponding image frame in step S2, the contrast sensitivity of the corresponding image frame is measured (S30).

Preferably, the contrast sensitivity of the image frame of the present invention is measured by using the following formula (2) according to the 'Weber Constrast' method of dividing the difference between the maximum luminance and the minimum luminance by the minimum luminance, The contrast sensitivity is measured. Contrast sensitivity generally refers to the visual ability to sense different light intensities.

(2)

WC (contrast sensitivity) = (Ymax - Ymin) / Ymin

* Ymax: maximum luminance (white luminance)

  Ymin: minimum luminance (black luminance)

By measuring the contrast sensitivity of the corresponding image frame, the regions having different luminance are distinguished.

As shown in an example of a divided area of an image frame of the lamp failure diagnosis method of the present invention in Fig. 5, the reference lines by the luminance difference of the right and left headlights of the vehicle are set by the above-described measurement of the contrast sensitivity.

That is, the area of the light of the left side headlight of the automobile and the area of the light of the right side headlight are divided by the second dividing line L2 and the left edge of the area of the light of the left headlight is divided into the first dividing line L1, And the right edge of the area of the light of the right headlight is set as the third dividing line L3 so that a section between the first dividing line L1 and the second dividing line L2, The divided sections of the corresponding image frame are selected as the section between the second division line L2 and the third division line L3. The regions of interest S1 and S2 to be described later are set in the area of the divided sections.

Next, in step S40, the failure diagnosis unit 30 determines whether the contrast sensed image frame is a significant image frame.

Specifically, if the differences in luminance of each of the predetermined n or more image frames are within the allowable error, it is determined that the image frame is significant. By judging the meaningfulness of the image frame, the driver is required to process the image frame or the like when the lamp is turned off, such as the headlight for a while, into a meaningless image frame in the lamp failure diagnosis.

Then, the failure diagnosis unit 30 selects a maximum contrast ratio range (Contrast Ration Max) existing within a reference distance of the corresponding image frame (S50).

In the embodiment of the present invention, the available area of the image frame is set to 3000 mm ± 100 mm to 6000 mm ± 200 mm, and the area having the maximum contrast ratio within the available area is selected to select the area of interest (S1, S2) So as to enable faster processing.

At this time, in order to select the maximum contrast ratio area, it is preferable to measure the luminance by applying a calibration value according to a specification of an image cell of the camera 10.

In addition, the failure diagnosis unit 30 sets a high magnification macro zone and a low magnification macro zone of the image frame (S60). The setting of the high magnification macro area and the low magnification macro area is intended to reduce the data sampling rate for fast signal processing when selecting the area of interest S1 or S2 to be described later.

Next, the failure diagnosis unit 30 selects at least one region of interest, which is a region to extract a luminance value in a divided section set according to the contrast sensitivity measured in the corresponding image frame, (S70).

FIG. 6 is a diagram showing a region of interest of the lamp failure diagnosis method of the present invention, in which a section between a first division line L1 and a second division line L2 shown in FIG. 5 and a second division line The first and second interest regions S1 and S2 for extracting the luminance value in the section between the first to fourth divided lines L2 to L3 are selected.

A data scan line (DSL) representing a point at which a luminance value is to be extracted is set in a region of each of the selected interest regions (S1, S2), and a first interest region The luminance values of the first and second regions of interest S1 and S2 are extracted.

Next, the failure diagnosis unit 30 calculates the peak value of the first interest region S1 and the second interest region S2 using the extracted luminance values of the first interest region S1 and the second interest region S2, (Peak-to-Peak Contrast) is calculated (S80).

Preferably, the calculation of the peak-to-peak ratio of the first region of interest S1 and the second region of interest S2 of the present invention is based on the Michelson Contrast method defined by the following equation (3) .

The Mickelson contrast method is a method of dividing the difference between the maximum luminance and the minimum luminance by the sum of the maximum luminance and the minimum luminance.

(3)

Peak-to-Peak contrast = (Ymax - Ymin) / (Ymax + Ymin)

* Ymax: maximum luminance (white luminance)

  Ymin: minimum luminance (black luminance)

Then, the failure diagnosis unit 30 calculates a peak-to-peak contrast value of the calculated first and second areas of interest S1 and S2 and a peak-to- It is determined whether the predetermined reference value is satisfied (S90), and it is determined whether or not the lamp is faulty. The reference value is defined in the form of a look-up table (LUT) in the failure diagnosis unit 30. [

FIG. 7 is a graph showing a luminance value and a reference value for each region of interest in the data scan line of the lamp failure diagnosis method of the present invention. The peak-to-peak ratio of the first region of interest S1 shown in FIG. 6 is a predetermined reference value The peak-to-peak ratio of the second area of interest S2 exceeds the warning reference value R. However, if the failure diagnosis section 30 determines that the failure has not occurred, ) Determines that the left front headlight, which is the light source of the second area of interest S2, is out of order.

Accordingly, if it is determined that the lamp of the light emitting source of the first area of interest S1 or the second area of interest S2 is malfunctioning, the failure diagnosis unit 30 outputs information indicating that the corresponding lamp is in a failure state, The warning display unit 40 transmits a warning indication to the cluster 50 of the vehicle 50 indicating that the headlamp FR of the car C is broken as shown in Fig. So that it is possible for the driver to easily recognize whether the lamp is broken or the function is deteriorated.

Meanwhile, the failure diagnosis unit 30 of the present invention can display the brightness output capability of the lamp in the form of geometric data.

9 is a geometric data indicating that the lamp is in a steady state, and FIG. 10 is a graph showing the performance degradation of the light source or the performance of the light source, And is geometric data indicating that the current lamp is in an abnormal state according to the disconnection.

Therefore, the lamp failure diagnosis method of the present invention can display the luminance output capability of the lamp as geometrical data as described above, thereby providing the lamp performance to the driver or maintenance person intuitively and visually, and quantitatively expressing the fractional deviation of the luminance But also a cut-off plane, which is an area to warn of a lamp failure, may be allocated to such geometrical data.

Description of the Related Art [0002]
10; Camera
20; The video signal input unit
30; The fault diagnosis unit
40; Warning Display
50; cluster
60; Cluster window
C; car
A1; Front camera sensing area
A2; Rear camera detection area
B1; Head light
B2; Tail light
D1; Forward direction indicator light
D2; Backward direction indicator light
DSL; Data scan line
S1; The first region of interest
S2; The second region of interest
L1; The first dividing line
L2; The second dividing line
L3; The third dividing line

Claims (12)

A method for diagnosing a lamp failure in an automobile,
An image frame generation step of receiving an image signal generated by an image capturing device installed in an automobile and photographing the front or rear of an automobile, converting the digital image signal into a digital signal, and generating an image frame at a predetermined time interval; And
A fault diagnosis procedure for receiving the image frame and determining whether the lamp of the automobile is faulty through brightness analysis of the image;
The lamp failure diagnosis method comprising the steps of:
2. The method according to claim 1,
A video signal of an outgoing light region of a front or rear lamp of a vehicle photographed by a camera installed in an automobile is input to the video signal input unit 20 and converted into an image frame (S10) and transmitted to the failure diagnosis unit 30 ;
The lamp failure diagnosis method comprising the steps of:
The fault diagnosis method according to claim 1,
The fault diagnosis unit 30 measures the contrast sensitivity of the image frame (S30);
A step (S70) of the luminance value existing in the region of interest by the fault diagnosis unit (30);
Calculating a peak-to-peak ratio of the ROI using the extracted luminance value of the ROI (S80);
(S90) of determining whether the lamp, which is a light emitting cause of the region of interest, is faulty according to whether the fault diagnosis unit (30) satisfies a predetermined reference value and a peak-to-peak ratio value of the calculated region of interest;
Wherein the lamp failure diagnosis method comprises the steps of:
4. The method of claim 3, wherein in the step of extracting the luminance value existing in the ROI (S70)
The region of interest is a region to extract a luminance value in a divided section set according to the contrast sensitivity measured in the image frame,
Wherein the at least one region of interest is selected.
4. The method of claim 3,
If the lamp of the area of interest is determined to be faulty, the fault diagnosis unit 30 displays a warning indicating failure of the lamp through the warning indication unit 40 (S100);
The method of claim 1, further comprising:
The fault diagnosis method according to claim 3,
(S20) the failure diagnosis unit 30 measures a contrast ratio for each input image frame; The method of claim 1, further comprising:
The fault diagnosis method according to claim 3,
(S40) determining whether the failure diagnosis unit (30) judges whether the image frame in which the contrast sensitivity is measured is a significant image frame; Further comprising:
The determination of the significant image frame may include:
Wherein the failure diagnosis unit (30) determines that the image frame is a significant image frame if the difference between the luminance values of the predetermined n or more image frames is within the allowable error.
The fault diagnosis method according to claim 6,
The failure diagnosis unit 30 selects a maximum contrast ratio range (Contrast Ration Max) existing within a reference distance of the image frame (S50); The method of claim 1, further comprising:
The fault diagnosis method according to claim 3,
The fault diagnosis unit 30 sets a high magnification macro zone and a low magnification macro zone of the image frame (S60); The method of claim 1, further comprising:
5. The method of claim 4, wherein the step (S70) of extracting a luminance value existing in the predetermined region of interest in operation S70 comprises:
A data scan line (DSL) indicating a point at which a luminance value is to be extracted is set in a region of a selected region of interest, and a luminance value of a region of interest is extracted along a data scan line (DSL) A method for diagnosing a lamp failure in an automobile.
The method of claim 3,
Wherein the failure diagnostic unit (30) displays the luminance output capability of the lamp as geometric data.
A recording medium containing a program for a method for diagnosing a lamp failure of an automobile according to any one of claims 1 to 11.

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