JP6190210B2 - Headlight control device - Google Patents

Description

  The present invention relates to a headlamp control device that detects a situation in front of a host vehicle and automatically switches a light distribution pattern, and particularly appropriately detects a front vehicle even when a road gradient changes in front of the host vehicle. Regarding what is possible.

In general, a headlight of a vehicle such as an automobile can be switched between a traveling beam (high beam) and a passing beam (low beam), or the traveling beam can be turned off independently of the passing beam. ing.
In recent years, the situation in front of the host vehicle is recognized by a camera, radar, etc., and when a front vehicle such as an oncoming vehicle or a preceding vehicle where glare (dazzle) can be a problem is detected, it automatically switches from high beam to low beam (Auto high beam function) has been proposed.

  As a conventional technique related to such an auto high beam, for example, in Japanese Patent Application Laid-Open No. 2003-260260, a vehicle headlamp that detects a forward vehicle by an in-vehicle camera or the like and switches between a high beam light distribution pattern and a low beam light distribution pattern For driving on a low beam regardless of the presence or absence of the detection of the preceding vehicle in order to prevent the oncoming vehicle from being detected and glare on the oncoming vehicle when traveling on a sharply curved road where the oncoming vehicle approaches from outside the angle of view (dead angle) The selection of a light distribution pattern is described.

Also, when performing auto high beam control, it is important to accurately identify the light source of the vehicle ahead.
As a conventional technique related to such light source identification, for example, Patent Document 2 describes that a light source is identified as a moving light source or a stationary light source and reflected in auto high beam control.

JP 2011-255826 A Patent No. 3660877

In the headlight control device having the above-described auto high beam function, a horizontal line that is a boundary between the ground and space is set in an image obtained by imaging the front of the host vehicle, and a predetermined locus is set below the horizontal line. The high luminance pixel group shown is recognized as a forward vehicle such as an oncoming vehicle or a preceding vehicle.
However, when the road surface slope changes like a valley in front of the host vehicle, the forward vehicle may be imaged above the horizontal line, etc. There is concern about glare on the vehicle.
The subject of this invention is providing the headlamp control apparatus which can detect a front vehicle appropriately, even if it is a case where the gradient of a road changes ahead of the own vehicle.

The present invention solves the above-described problems by the following means .

The invention according to claim 1 is a headlamp control device that automatically switches the light distribution pattern of a headlamp that illuminates the front of the host vehicle, the imaging means for sequentially capturing images in front of the host vehicle, and the imaging The other light recognition means for recognizing the light source of the other vehicle from the images sequentially picked up by the means, and the light distribution pattern so that dazzling to the other vehicle is suppressed according to the recognition of the light source of the other vehicle by the other vehicle recognition means. A headlamp control device comprising a light distribution control means for switching, and a gradient change detecting means for detecting a change of a slope of a road surface ahead of the host vehicle in a lane in which the host vehicle is traveling with respect to a slope of the currently traveling road surface. The other vehicle recognition means sets a predetermined horizontal line in the image and recognizes a high-luminance pixel group satisfying a preset condition below the horizontal line as an other vehicle, The gradient change When the detecting means detects a change in gradient in the upward direction, the horizontal line is offset upward with respect to traveling on flat ground, and when the gradient change in the downward direction is detected, the horizontal line is offset with respect to traveling on flat ground. The headlamp control device is characterized by being offset downward.
According to this, when the horizontal line is appropriately set by offsetting the horizontal line upward and downward according to the gradient change ahead of the host vehicle, and the gradient change detecting means detects the gradient change in the upward direction. By offsetting the horizontal line upward with respect to traveling on flat ground, it becomes possible to appropriately detect the forward vehicle existing above the forward vehicle detection area during traveling on flat ground.
On the other hand, when a change in gradient in the downward direction is detected, the horizontal line is offset downward with respect to traveling on flat ground, so that a light source such as a street lamp existing above the ground is in front vehicle detection area when traveling on flat ground. It is possible to prevent the vehicle from being mistakenly recognized as a vehicle ahead.

According to a second aspect of the present invention, the imaging means has a stereo camera capable of sequentially detecting the relative distance of the imaged light source to the own vehicle, and the other vehicle recognition means is a transition of the relative distance of the light source to the own vehicle. The headlamp control device according to claim 1, wherein a light source of the other vehicle is recognized based on the headlight.
According to this, it is possible to accurately determine whether the detected light source is a moving light source such as an oncoming vehicle or a preceding vehicle or a fixed light source such as a streetlight.

  As described above, according to the present invention, it is possible to provide a headlamp control device that can appropriately detect a preceding vehicle even when the road gradient changes in front of the host vehicle.

It is a block diagram which shows the structure of Example 1 of the headlamp control apparatus to which this invention is applied. It is a figure which shows typically an example of the image ahead of the own vehicle in the headlamp control apparatus of Example 1. FIG. It is a flowchart which shows the auto high beam control in the headlamp control apparatus of Example 1. FIG. It is a schematic diagram which shows the positional relationship with an oncoming vehicle, the oncoming vehicle position on a captured image, and horizontal line correction | amendment when the own vehicle is drive | working the downhill. It is a schematic diagram which shows the positional relationship with an oncoming vehicle, the oncoming vehicle position on a captured image, and horizontal line correction | amendment when the own vehicle is driving | running the uphill.

  The present invention aims to provide a headlight control device capable of appropriately detecting a front vehicle even when the road gradient changes in front of the host vehicle, the road surface gradient on which the host vehicle is traveling, or The problem was solved by offset-correcting the horizontal line set in the captured image in accordance with the change in the gradient in front of the host vehicle.

Embodiment 1 of a headlamp control apparatus to which the present invention is applied will be described below.
The headlamp control device according to the first embodiment is provided at the front of a vehicle body of an automobile such as a passenger car, for example, and controls a headlamp that irradiates a predetermined area in front of the host vehicle.

FIG. 1 is a block diagram illustrating a configuration of a headlamp control apparatus according to an embodiment.
As shown in FIG. 1, the headlamp control device 1 includes a left headlamp 11, a right headlamp 12, a controller 20, a headlamp unit 30, a camera unit 40, a travel information detection unit 50, and a gradient detection means 60. Etc. are configured.

The left headlamp 11 and the right headlamp 12 are provided on the left and right of the front part of the vehicle body, respectively.
The left headlight 11 and the right headlamp 12 are, for example, a high beam (traveling beam) that irradiates the front of the host vehicle to, for example, 100 m or more, and a low beam (passing beam) that irradiates the front of the host vehicle, for example, by about 40 m. Can be selected.
The left headlight 11 and the right headlight 12 are, for example, a light source such as an LED for high beam and low beam, and a projector-type or reflector-type optical system that projects light generated by the light source in a predetermined light distribution pattern. Respectively.
The light source for high beam and low beam can be turned on and off independently, and the low beam is also turned on simultaneously when the high beam is turned on.

The controller 20 supplies power supplied from a power source such as a battery (not shown) to the light sources of the left headlight 11 and the right headlamp 12.
The controller 20 turns on and off the high beam light source and the low beam light source of the left headlamp 11 and the right headlamp 12 in accordance with a control signal from the headlamp control unit 30.

The headlamp control unit 30 is an information processing apparatus that comprehensively controls various electrical components provided on the vehicle body.
The headlamp control unit 30 includes an information processing device such as a CPU, storage means such as a RAM and a ROM, an input / output interface, a bus connecting these, and the like.
The headlight control unit 30 has a function of giving a control signal to the controller 20 and switching the left headlight 11 and the right headlight 12 between high beam lighting, low beam lighting, and extinguishing.

A switch 31, an illuminance sensor 32, and the like are connected to the headlamp control unit 30.
The switch 31 is, for example, an operation input means that is provided in a steering column portion or the like in the vehicle interior and that allows the driver to operate the headlamp.
For example, the switch 31 can select the auto mode in addition to manual selection of off (lights off), low beam lighting, and high beam lighting.
In the auto mode, the headlamp is automatically turned on and off by detecting light and darkness outside the vehicle.

The auto mode further includes an auto high beam mode.
In the auto high beam mode, the presence or absence of lights (light sources) of front vehicles such as an oncoming vehicle and a preceding vehicle, and urban driving are determined based on time-series images obtained by sequentially capturing the front of the host vehicle with the camera unit 40. During normal times, high beam lighting is performed, and when a vehicle ahead is detected within a predetermined range or when traveling in an urban area is detected, the light beam is automatically switched to low beam lighting.
The headlamp control unit 30 functions as other vehicle recognition means for recognizing the light source of another vehicle based on information from the camera unit 40 or the like, and as a light distribution control means for switching between high beam lighting and low beam lighting according to the recognition result. .

The illuminance sensor 32 is a brightness sensor that detects the brightness outside the vehicle.
The illuminance sensor 32 is provided, for example, in the passenger compartment at the peripheral edge of the front window glass.

The camera unit 40 includes, for example, a stereo camera that images the front of the host vehicle with a pair of cameras that are spaced apart in the vehicle width direction, and a stereo image processing unit that performs image processing on the captured image.
The camera unit 40 sequentially captures a range included in a predetermined angle of view at a predetermined frame rate by using a solid-state image sensor such as a CMOS or CCD, and sequentially controls the obtained time-series image data. Provide to unit 30.
Further, the camera unit 40 can detect the relative distance from the own vehicle to the subject by the principle of triangulation based on the parallax on the stereo image of the pixel group corresponding to the specific subject by a known stereo image processing technique. It has become.
For example, the camera unit 40 is provided adjacent to a room mirror base (upper end portion of the front window glass) in the vehicle interior.

A vehicle speed sensor, a steering angle sensor, a vehicle body lateral acceleration sensor, a vehicle body yaw rate sensor, and the like (not shown) are connected to the travel information detection unit 50.
Based on the output of each of these units, the travel information detection unit 50 informs the headlamp control unit 30 of vehicle state information such as vehicle speed, rudder angle (handle angle), vehicle body lateral acceleration (lateral G), vehicle body yaw rate, etc. provide.

The inclination detecting means 60 detects a gradient (inclination) in the front-rear direction of the road surface on which the host vehicle is traveling.
For example, the inclination detection unit 60 detects the gradient based on information on an acceleration sensor that detects acceleration in the longitudinal direction of the vehicle and transmission torque that is not shown in the figure, which is acquired from a transmission control unit (not shown) that comprehensively controls the transmission of the vehicle. It has an estimation means for estimation and the like.

Next, light source recognition for auto high beam control in the headlamp control apparatus of the embodiment will be described.
FIG. 2 is a diagram schematically illustrating an example of an image in front of the host vehicle in the headlamp control apparatus according to the embodiment.
The image 100 includes, for example, pixel groups corresponding to the own vehicle traveling lane 101, the oncoming lane 102, the guard rail 103, the reflector 104, the streetlight 105, the oncoming vehicle 106, and the like.

Further, in the image 100, a horizontal line H that is a reference line in image processing is provided.
The horizontal line H is a line indicating the boundary between the road surface portion and the space portion, and extends in the horizontal direction at the center of the image 100.
In the nighttime, in the image 100, a pixel group mainly corresponding to the light source is detected.
When the images 100 sequentially captured are compared in time series, the light from the reflector 104 and the street lamp 105 existing on the left side of the host vehicle is displaced in the lower left direction and the upper left direction from the center of the screen with time.
Moreover, the light of the reflecting plate 104 existing on the right side (opposite lane side) of the host vehicle is displaced from the center of the screen to the lower right direction with the passage of time.

On the other hand, the headlamp of the oncoming vehicle 106 is characterized by being brighter than other light sources and being displaced from the center of the screen in the lower right direction below the horizontal line H.
The headlamp control unit 30 can recognize and detect the oncoming vehicle 106 based on such characteristics.
When a red high-luminance pixel group corresponding to the tail lamp is detected on the traveling lane ahead of the host vehicle and below the horizontal line H, the vehicle is recognized as a preceding vehicle.
Further, when light sources other than the vehicle such as the street lamp 105 are distributed more than a predetermined reference, it is determined that the vehicle is traveling in the city, and the headlamp control unit 30 determines that the left headlamp 11 and the right front lamp Both the illumination lamps 12 are set to low beam lighting.

In the first embodiment, the horizontal line H is corrected to be offset up and down in accordance with the gradient in the front-rear direction of the road surface on which the host vehicle is traveling.
FIG. 3 is a flowchart showing auto high beam control in the headlight control apparatus of the embodiment.
Hereinafter, the steps will be described step by step.
In the initial state, the left and right headlamps 11 and 12 are in a high beam lighting state.
<Step S01: Light Source Detection>
The headlamp control unit 30 extracts a pixel group having a predetermined luminance or higher from the image captured by the camera unit 40 as a light source.
Thereafter, the process proceeds to step S02.

<Step S02: gradient detection>
The headlamp control unit 30 acquires information regarding the gradient of the road surface on which the host vehicle is currently traveling from the gradient detection means 60.
This information includes information regarding the gradient value, which is a parameter regarding the magnitude of the gradient.
Thereafter, the process proceeds to step S03.

<Step S03: Slope determination>
The headlamp control unit 30 recognizes that the vehicle is traveling on a slope when the slope value acquired in step S02 is equal to or greater than a predetermined value, and proceeds to steps S04 and S05.
On the other hand, if the gradient value is less than the predetermined value, it is recognized that the vehicle is traveling on a flat ground, and the process proceeds to step S07.

<Step S04: Horizontal line offset according to the gradient value>
The headlamp control unit 30 performs correction for offsetting the horizontal line H used in the above-described light source recognition in the vertical direction according to the gradient value acquired in step S02.

FIG. 4 is a schematic diagram showing the positional relationship with the oncoming vehicle, the oncoming vehicle position on the captured image, and the horizontal line correction when the host vehicle is traveling downhill.
4A is a schematic side view of the road surface, the host vehicle 200, and the oncoming vehicle 106, and FIG. 4B is a schematic diagram illustrating an example of the captured image (in FIG. 5 described later). The same).
As shown in FIG. 4A, when the host vehicle 200 is traveling on a downhill, the flat road existing in front of the downhill looks up above the vehicle longitudinal direction of the host vehicle 200. You will see the direction.
If the oncoming vehicle 106 is traveling in such an area, the oncoming vehicle 106 exists above the horizontal line H in the image 100, and the oncoming vehicle 106 approaches the horizontal line in normal light source recognition. Recognition as an oncoming vehicle is not established until the vehicle is below H, and the high beam state is maintained and glare is imparted.
Thus, in the first embodiment, when the host vehicle 200 is traveling on a downhill, correction is performed to shift the horizontal line H upward according to the gradient value.
This shift amount is set so as to increase as the gradient value increases.

FIG. 5 is a schematic diagram showing the positional relationship with the oncoming vehicle, the oncoming vehicle position on the captured image, and the horizontal line correction when the host vehicle is traveling uphill.
As shown in FIG. 5A, when the host vehicle 200 is traveling on an uphill, the lane ahead of the host vehicle is imaged only up to the vicinity of the end of the uphill on the image 100. However, it is practically impossible to capture and detect a forward vehicle traveling far away. For this reason, even if the horizontal line H is offset downward, the detection performance of the preceding vehicle is not affected.
On the other hand, as shown in FIG. 5 (b), a part of the light source such as the street lamp 105 existing farther from the end of the uphill is imaged below the horizontal line H when traveling on a flat road. If light source recognition is performed without correcting the horizontal line H, there is a concern that this may be erroneously recognized as a forward vehicle.
Therefore, in the first embodiment, when the host vehicle 200 is traveling uphill, correction is performed to shift the horizontal line H downward according to the gradient value.
This shift amount is set so as to increase as the gradient value increases.
After performing the offset of the horizontal line H described above, the process proceeds to step S07.

<Step S05: Light Source Relative Distance Calculation>
The camera unit 20 detects the relative distance from the host vehicle to the light source by known stereo image processing, and sequentially transmits it to the headlamp control unit 30.
Thereafter, the process proceeds to step S06.

<Step S06: Dynamic Light Source Determination>
The headlamp control unit 30 calculates the relative speed and the relative movement direction of the light source with respect to the host vehicle based on the time history of the relative distance from the host vehicle to the light source acquired in step S05.
The headlamp control unit 30 calculates the ground movement speed and direction of the light source based on the relative speed of the light source with respect to the host vehicle and the vehicle speed and turning state of the host vehicle provided from the travel information detection unit 50.
And when the ground movement speed of a light source is more than predetermined value, it recognizes that the said light source is moving light sources, such as an oncoming vehicle and a preceding vehicle, and progresses to step S09.
On the other hand, when the ground moving speed of the light source is less than the predetermined value, the light source is recognized as a stationary light source such as a streetlight, and the process proceeds to step S07.

<Step S07: Normal vehicle detection>
The headlamp control unit 30 performs the above-described normal vehicle detection (light source recognition).
Thereafter, the process proceeds to step S08.

<Step S08: Forward vehicle judgment>
The headlamp control unit 30 proceeds to step S09 if a forward vehicle (an oncoming vehicle or a preceding vehicle) is detected in step S07, and returns to step S01 if no forward vehicle is detected. Repeat the process.

<Step S09: High beam off>
The headlamp control unit 30 outputs a control signal to the controller 20 so that both the left headlamp 11 and the right headlamp 12 are turned off in a high beam and in a low beam.
Thereafter, the series of processing is terminated (returned).

According to the first embodiment described above, when the host vehicle 200 is traveling on a road surface having a downward slope, the front vehicle existing in the direction of looking up from the host vehicle 200 by offsetting the horizontal line H upward. Can be detected appropriately.
As a result, the vehicle ahead can be found early and the high beam can be turned off, and glare can be prevented.
On the other hand, when the host vehicle 200 is traveling on an uphill road surface, by offsetting the horizontal line H downward, a light source such as a street lamp 105 existing above the ground is erroneously recognized as a preceding vehicle. Can be prevented.
In addition, by detecting the speed of the light source using a stereo camera, it is possible to accurately determine whether the detected light source is a moving light source such as an oncoming vehicle or a preceding vehicle or a fixed light source such as a streetlight. .

Next, a second embodiment of the headlamp control apparatus to which the present invention is applied will be described.
In the following, portions that are substantially the same as those of the first embodiment described above are denoted by the same reference numerals, description thereof is omitted, and differences are mainly described.
The headlamp control device according to the second embodiment uses a navigation device (not shown) instead of the gradient detection unit 60 according to the first embodiment, and the gradient of the road surface on which the vehicle is currently traveling is the gradient of the traveling lane of the vehicle ahead of the vehicle. Is detected, and the horizontal line H is offset-corrected in accordance with the change in gradient.
The navigation device holds terrain data (map data) including a lane shape and a gradient, and includes own vehicle position detection means such as GPS.

When the gradient in front of the host vehicle changes in the upward direction, the headlamp control unit 30 performs correction for offsetting the horizontal line H upward according to the amount of change.
Here, when the slope changes in the upward direction, for example, when the vehicle is currently traveling on a downhill and is a flat road ahead, the vehicle is currently traveling on a downhill and the slope is gentle ahead For example, a case where the vehicle is currently traveling on a downhill or a flat road and is an uphill in front, a case where the vehicle is currently traveling on an uphill and the slope is steep in front, and the like.

On the other hand, when the gradient in front of the host vehicle changes in the downward direction, the headlamp control unit 30 performs correction for offsetting the horizontal line H downward according to the amount of change.
Here, when the slope changes in the downward direction, for example, when the vehicle is currently traveling uphill and is a flat road ahead, the vehicle is currently traveling uphill and the slope is gentle ahead For example, a case where the vehicle is currently traveling on an uphill or a flat road and has a downhill in front, a case where the vehicle is currently traveling on a downhill, and the slope is steep in front is applicable.

  According to the second embodiment described above, the horizontal line H is appropriately set by offsetting the horizontal line H upward and downward in accordance with the gradient change in front of the host vehicle. Therefore, the same effect can be obtained more reliably.

(Modification)
The present invention is not limited to the embodiments described above, and various modifications and changes are possible, and these are also within the technical scope of the present invention.
(1) The configuration of the headlamp control device and the headlamp is not limited to the embodiment described above, and can be changed as appropriate.
For example, in the embodiment, the automatic high beam control switches between the high beam and the low beam. However, the present invention is not limited to this. For example, in a headlamp having a plurality of light distribution patterns for a high beam, the high beam distribution pattern is moved forward. It may be switched so that glare is suppressed according to the recognition result of the light source.
(2) In the embodiment, the LED light source is used as the light source of the headlamp. However, the present invention is not limited to this, and other types of light sources may be used. Also, the type of optical system is not particularly limited.

DESCRIPTION OF SYMBOLS 1 Headlamp control apparatus 11 Left side headlamp 12 Right side headlamp 20 Controller 30 Headlamp control unit 31 Switch 32 Illuminance sensor
40 camera unit 50 travel information detection unit 100 image 101 own vehicle travel lane 102 opposite lane 103 guardrail 104 reflector 105 street light 106 oncoming vehicle 200 own vehicle

Claims (2)

A headlamp control device that automatically switches the light distribution pattern of a headlamp that illuminates the front of the host vehicle,
Imaging means for sequentially capturing images ahead of the host vehicle;
Other vehicle recognition means for recognizing the light source of another vehicle from the images sequentially captured by the imaging means;
A headlamp control device comprising: a light distribution control means for switching the light distribution pattern so that dazzling to another vehicle is suppressed in accordance with recognition of a light source of the other vehicle by the other vehicle recognition means,
Gradient change detecting means for detecting a change in the gradient of the road surface in front of the vehicle in the lane in which the vehicle is traveling with respect to the gradient of the currently running road surface,
The other vehicle recognizing unit sets a predetermined horizontal line in the image, recognizes a high-luminance pixel group satisfying a preset condition below the horizontal line as an other vehicle, and the gradient. When the change detecting means detects a gradient change in the upward direction, the horizontal line is offset upward with respect to traveling on flat ground, and when the gradient change in the downward direction is detected, the horizontal line is offset with respect to traveling on flat ground. The headlamp control device is characterized in that it is offset downward. The imaging means has a stereo camera capable of sequentially detecting the relative distance of the imaged light source to the vehicle,
The headlamp control device according to claim 1, wherein the other vehicle recognition unit recognizes a light source of the other vehicle based on a transition of a relative distance of the light source to the host vehicle.

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