JPH07186818A - Automatic light distribution device for vehicle head lamp - Google Patents

Abstract

PURPOSE:To perform illumination which corresponds to the corner state of a road, and perform suitable illumination without dazzling a forward running car by setting the illuminating direction, utilizing the forward running car when the forward running car exists, and utilizing a white line on the road when the forward running car does not exist. CONSTITUTION:A CCD camera 11 takes a picture of the road state, by which a road state recognition unit 1 recognizes the road state ahead, and the recognized results are inputted to a control unit 3. At this time, a driving signal is fed from the control unit 3 to a head lamp driving unit 2A to change the illuminating direction of a head lamp 2. The control unit 3 is composed of a controller 31 and a motor driver 32 for driving the head lamp driving unit 2A, and is structured to be able to recognize a white line on the road in front of a vehicle, and a forward running car. The control unit 3 is structured to select either of control based on the recognized white line and control based on the recognized forward running car, and optical illumination is performed in answer to the presence or absence.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for automatically controlling a light distribution characteristic of a headlight of a vehicle such as an automobile, and more particularly, it automatically recognizes a road condition to control an irradiation direction of the headlight. For equipment.

[0002]

2. Description of the Related Art In general, when traveling on a curved road (corner) in an automobile, it is preferable from the viewpoint of safe driving to direct the irradiation direction of the headlight toward the corner. Therefore, conventionally, there has been proposed one in which the irradiation direction of the headlight is changed in association with the steering wheel of the automobile so that the corner side is irradiated. However, in this system, since the irradiation direction is changed by actually rotating the handle,
Immediately before entering the corner, the irradiation direction cannot be directed to the corner side, and there is a problem that the driver cannot confirm the corner in advance. In particular, such a problem becomes remarkable in an operating state in which the steering wheel is rapidly switched like an S-shaped road.

In order to solve such a problem, in recent years, there has been proposed a vehicle which automatically recognizes a road condition ahead, particularly a curved road, and controls the irradiation direction of a headlight. For example, in Japanese Unexamined Patent Publication No. 4-260106, CC is attached to an automobile.
Equipped with a D camera, the CCD camera performs image recognition of, for example, a white line for distinguishing lanes on a road, and based on the curved road information obtained from this recognition, deflect the headlight along a curved road in the irradiation direction. It is what

[0004]

In the irradiation direction control by the automatic recognition method, since the irradiation direction of the headlight is determined in accordance with the actual curved state of the road, the irradiation direction must be controlled before the steering wheel is operated. And is superior in terms of safe driving compared to the one that follows the steering wheel operation. However, in this method, since the CCD camera recognizes the white line on the road to control the irradiation direction, the irradiation direction may be unilaterally controlled regardless of an oncoming vehicle or a preceding vehicle. Even if there is an oncoming vehicle ahead of the vehicle, or if there is a preceding vehicle ahead of the vehicle ahead of the corner, the irradiation direction will be uniquely controlled, resulting in dazzling the oncoming vehicle or the preceding vehicle. There is. Further, in the method of recognizing the white line by the CCD camera, since the white line illuminated by the headlight light of the vehicle is image-recognized, the range in which sufficient illuminance for recognition is obtained is 10 to 30 m in front of the vehicle. There is also a problem that the irradiation control cannot follow the traveling of the own vehicle at the time of high-speed traveling, and satisfactory control cannot be performed, because the irradiation control is only within a certain range. It is an object of the present invention to provide a headlight automatic light distribution device capable of recognizing a far range in front of the vehicle and appropriately controlling the irradiation direction of the headlight.

[0005]

According to the present invention, there is provided an image pickup means for picking up an image of a road condition in front of a vehicle, and a light distribution characteristic thereof which can be changed by changing a direction of irradiation of a part of a headlight light of the vehicle. The headlight drive means and the control means for recognizing the road condition based on the image pickup signal of the image pickup means and controlling the drive of the headlight drive means are provided, and the control means is at least the white line on the road ahead of the vehicle and the preceding line. The vehicle is recognizable, and the control for driving the headlight driving means based on the recognized white line and the control for driving the headlight driving means based on the recognized preceding vehicle are selectable.

[0006]

When the preceding vehicle is present in the predetermined area, the light irradiation direction is set by using the preceding vehicle, and when the preceding vehicle is not present or is outside the predetermined area, the light irradiation direction is set by using the white line. By doing so, it is possible to realize the light irradiation corresponding to the corner condition of the road, and it is also possible to perform the suitable light irradiation to the far range in front of the own vehicle.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. FIG. 1 is a schematic block diagram showing the overall configuration of the headlight automatic light distribution device of the present invention. This control device controls the irradiation direction of the headlamp 2 based on the road condition recognition unit 1, the headlight 2 whose irradiation direction can be changed by the drive unit 2A, and the recognition result of the road condition recognition unit. It is composed of the control unit 3. The road condition recognition unit 1 has a CCD camera 11 arranged at a relatively high position in front of the car CAR, for example, at the upper edge of the windshield, and images the road surface in front of the vehicle. . A vehicle speed sensor 12 that detects the speed of the vehicle is also provided.

As shown in FIG. 2, the CCD camera 11 is an optical system 111 for image formation for picking up an image of the front of the vehicle.
A beam splitter 112 for separating the imaged light into light having a longer wavelength than red light (hereinafter referred to as red light) and light having a wavelength shorter than red light (hereinafter referred to as blue light),
A pair of CCDs that convert each separated light imaged into an electric signal
It is composed of 113 and 114. The beam splitter 112 has a structure in which an interference film or the like is formed on a transparent substrate, and is configured as a dichroic mirror that transmits blue light and reflects red light. Therefore, one CC
D113 is configured as a blue light CCD for detecting blue light, and the other CCD 114 is a red CCD for detecting red light.
Configured as.

The headlight 2 is applied to a headlight called a low beam of an automobile. As shown in FIG. 3 which shows a schematic structure of one side of the left and right headlights, a lamp body 21 and a lens 22 are provided. Defines a light room, and a light bulb 23 is supported in the light room, and a main reflecting mirror 24 disposed behind the light bulb 23.
Is configured to reflect the bulb light toward the front of the headlight. Further, between the main reflecting mirror 24 and the light bulb 23, a sub-reflecting mirror 25 which is rotatable around the light bulb in a small angle in the horizontal direction is arranged. Also, the lamp body 2
A motor 26 is disposed inside one side of the crankshaft 1, and a crank 27 rotated by the motor 26 and the sub-reflecting mirror 25 are connected by a connecting rod 28.

Therefore, when the motor 26 is rotated by a required angle, the sub-reflecting mirror 25 is rotated around the light bulb by a slight angle via the crank 27 and the connecting rod 28, and a part of the light from the light bulb 23 is partially rotated. The reflected direction, that is, the irradiation direction of a part of the irradiation light of the headlight can be changed to the left and right. Although not described in detail, a potentiometer 29 as an irradiation direction detecting sensor is connected to the crank 27, and the output of the potentiometer 29 causes the crank 27 to rotate, that is, the sub-reflecting mirror 25. It is possible to detect the rotation position of, and more specifically, the irradiation direction of a part of the irradiation light in the headlight 2. The sub-reflecting mirror 25, the motor 26, and the like constitute the headlamp irradiation direction drive unit 2A.

The control unit 3 includes a controller 31 including a microcomputer, and the controller 31.
And a motor driver 32 for driving the motor 26 of the headlight drive section 2A. The controller 31 receives signals from the CCDs 113 and 114 of blue and red lights of the road condition recognizing unit and a detection signal of the vehicle speed sensor 12, respectively. Further, the detection signal of the irradiation direction detection sensor 29 provided in the headlight drive unit 2A is input as a feedback signal. Then, the controller 31 recognizes the road condition ahead of the own vehicle based on these signals and also recognizes the irradiation condition at that time, and based on this, the motor driver 32 changes the irradiation direction of the headlight 2. Executes an operation that controls change.

The operation of controlling the headlamp irradiation direction by the apparatus of the present invention having the above-mentioned structure will be described. First, in the road condition recognition unit 1, the optical system 11 of the CCD camera 11 is set on the road in front of the vehicle.
Image by 1. Then, the blue light and the red light separated by the beam splitter 112 are detected by the blue light CCD 113 and the red light CCD 114, respectively, and when the detected signals are input to the controller 31, the controller 31 outputs C
Each CCD 11 at a corresponding position on the screen of the CD camera 11
The signal intensities of 3,114, that is, the amounts of light are compared. Figure 4
(A) and (b) are blue light CCD 113 and red light CCD 1
It is a figure which shows each image of 14 typically, and has shown the state where a signal is output from the light receiving element corresponding to the lane part of each figure. In this case, on the road ahead of the host vehicle, the ratio R of the amount of blue light and the amount of red light in the CCD that formed the white line of the road
C which imaged DR and headlight (white or yellow) of oncoming vehicle
Comparing the ratio HLR of blue light and red light in the CD element with the ratio TLR of blue light and red light in the CCD element that images the taillight (red) of the preceding vehicle, the following relationship is obtained. is there. HLR> TLR ... (1-1) RDR> TLR ... (1-2)

Further, there is a relationship of HLV>TLV> RDV (2) among the light quantities RDV, HLV, TLV of the CCD elements which image the white line, the oncoming vehicle and the preceding vehicle. Therefore, it is possible to recognize the white line, the oncoming vehicle, and the preceding vehicle existing in front of the own vehicle by sequentially comparing the light amounts of blue light and red light in each CCD and their ratios. However, in the image recognition by the current CCD camera, it is difficult to distinguish road lights and city lights from the lights of an oncoming vehicle and a preceding vehicle ahead of 100 m or more because the imaged light becomes small. And its accuracy is somewhat reduced.

However, even in this case, the speed at which the detected light is moved on the CCD screen and the vehicle speed sensor 12 are used.
By comparing the vehicle speed of the own vehicle obtained from the controller 31 with the controller 31, it is possible to calculate the absolute speed of the detection light that is moving. If the absolute speed of the detection light is zero, the road sign is displayed. If the absolute speed of the detected light is other than zero, it can be determined that it is a city light or
Alternatively, it can be determined that the vehicle is an oncoming vehicle.

When the white line is recognized, the controller 31 can detect the state of the white line by edge-processing the signal from the CCD camera 11. Examples of this edge processing include those described in "Automatic driving system by computer vision" (corporation incorporated body, Society of Automotive Engineers of Japan, Pre-Academic Lecture Collection 924, 1992-10) and the like. As a result,
It is possible to recognize the white line state in front of -30 m.

The CCD camera 11 that recognizes the preceding vehicle
The distance to the preceding vehicle is detected by using the signal from. That is, as shown in FIG. 5, the focal length of the optical system of the CCD camera provided in the own vehicle is f, the height of the optical axis O from the road surface is H, and the preceding vehicle is recognized with respect to this optical axis. Done C
The length of the CD element in the upward direction from the optical axis is h. Further, the height of the tail light TL of the preceding vehicle is set to H '(the height of the tail light is slightly different depending on the vehicle type, but the difference in the degree does not have a great influence from the recognition accuracy in the present invention).
The distance D from the own vehicle to the preceding vehicle is D = (H−H ′) × f / h (3) For example, as shown by the chain line in FIG. 4, this distance D
Corresponds to the Y coordinate on the CCD screen. Although detailed description is omitted, the distance D and the horizontal length of the CCD element that recognizes the preceding vehicle from the optical axis are used to determine whether the preceding vehicle is on the left or right of the own vehicle. It is possible to detect the position and how much the position is displaced.

Then, the controller 31 recognizes the white line, the oncoming vehicle, and the preceding vehicle based on the signal from the CCD camera 11, and the motor driver 32 operates the sub-reflecting mirror 25 of the headlight 2 based on the result. Control the light irradiation direction. In this control, here, two types of control, that is, a "preceding vehicle following mode" and a "road surface processing mode" can be performed.

In the former "preceding vehicle following mode", the light irradiation direction is controlled toward the position where the preceding vehicle exists so as not to dazzle the preceding vehicle. That is, by recognizing the preceding vehicle, the following vehicle can recognize the corner condition of the road on which the vehicle is going to travel. Therefore, by controlling the light irradiation direction toward this preceding vehicle, it is as far as possible. Suitable light irradiation toward the front position is possible. Also, the latter "road surface processing mode" recognizes the white line of the road as described above,
The corner state of the road is recognized from this white line, and the irradiation direction is controlled in the direction of the bending point of this corner. FIG. 6 shows an example thereof. In this case, suitable light irradiation is possible within a range of 30 m ahead of the own vehicle.

Next, the actual control of the irradiation direction will be described with reference to the flowchart of FIG. First, when the controller 31 takes in a signal from the CCD camera 11, the presence / absence of an oncoming vehicle is determined by using the equations (1-1), (1-2) and (2). When there is an oncoming vehicle, the "road surface treatment mode" is performed in order to reliably prevent the oncoming vehicle from being dazzled. As a result, light irradiation is performed within a range of 30 m in front of the vehicle. If there is no oncoming vehicle, it is next determined whether or not there is a preceding vehicle. As a result, when neither the oncoming vehicle nor the preceding vehicle is present, there is no fear of dazzling, and the high beam headlight (not shown) is turned on.

On the other hand, when the preceding vehicle is present, the distance from the oncoming vehicle to the own vehicle and the left or right position of the oncoming vehicle in front of the own vehicle are determined based on the equation (3). It is recognized and then it is determined whether or not the preceding vehicle is within the first specified distance range (for example, the distance from the own vehicle is 10 to 80 m). When the preceding vehicle does not exist within the first designated distance range but exists ahead in the distance, the CCD camera 1
From the relationship between the recognition angle of view of 1 and the distance between the preceding vehicle and the road ahead, it can be estimated that the road is close to a straight line, so the "road surface processing mode" is performed. This is because there is no steep corner in such a road condition, and therefore even if the irradiation direction is controlled based on the recognition information of the white line within 30 m obtained in the "road surface processing mode", it is safe driving. This is because sufficient light irradiation can be performed.

On the other hand, when the preceding vehicle is present within the first designated distance range, the preceding vehicle is further moved to the second designated distance range (for example, own vehicle) based on the recognition result obtained in the previous process. (The distance between the vehicle and the vehicle is 10 to 30m, and it is in the same lane as your vehicle)
Is present in the. When the vehicle does not exist in the second specified distance range, even if the headlight light of the host vehicle is emitted toward the vicinity of the preceding vehicle, the influence on the preceding vehicle is small, so that the "preceding vehicle following mode" is set. Perform processing. As a result, it becomes possible to appropriately irradiate the road on which the vehicle is going to travel with the preceding vehicle.

If the preceding vehicle is within the second specified distance range, the preceding vehicle is likely to be affected, so the "road surface processing mode" is executed. Of course, in this case, the traveling speed is often relatively low in view of the vehicle-to-vehicle distance from the preceding vehicle.
Even if the irradiation direction is controlled while recognizing the white line in the range of 0 m, it does not adversely affect the safe driving, and the irradiation direction can be controlled appropriately.

Therefore, by controlling the light irradiation direction by the white line recognition method and the light irradiation control by using the preceding vehicle according to the road condition, the front of the own vehicle, which has been insufficient by the conventional white line recognition method, is controlled. Even in the distant range, it is possible to perform suitable light irradiation in accordance with the road condition, and it is possible to realize extremely effective control of the irradiation direction of the headlight in terms of safe driving. Needless to say, oncoming vehicles and preceding vehicles are not dazzled.

In the CCD camera, the beam splitter may be composed of a half mirror, and a red filter and a blue filter may be provided in front of each CCD. In addition, the drive unit that controls the irradiation direction of the headlight is a cam,
Various structures such as a screw mechanism can be adopted. Further, the first and first designated distance ranges are not limited to the values in the embodiment, and the distance ranges are arbitrarily set according to the sensitivity of the CCD camera, the illuminance level of the headlight of the vehicle, and the like. It is possible.

[0025]

As described above, the present invention is configured to recognize the white line on the road ahead of the vehicle and the preceding vehicle to control the irradiation direction of the headlight of the vehicle, and the white line recognized at this time. Since the control for driving the headlight drive means based on the above and the control for driving the headlight drive means based on the recognized preceding vehicle are selected to control the irradiation direction, When the vehicle exists in a predetermined area, the light irradiation direction is set using the preceding vehicle, and when there is no preceding vehicle or the area is outside the predetermined area, the white irradiation line is used to set the light irradiation direction. There is an effect that the light irradiation corresponding to the corner condition of the road can be realized, and the suitable light irradiation can be performed even in the far area in front of the own vehicle without dazzling the preceding vehicle.

[Brief description of drawings]

FIG. 1 is a block configuration diagram showing an overall configuration of the present invention.

FIG. 2 is a diagram showing a configuration of a CCD camera.

FIG. 3 is a schematic diagram showing a configuration of a headlamp driving unit.

FIG. 4 is a diagram of a CCD screen for explaining a method of recognizing a road condition in a CCD camera.

FIG. 5 is a diagram for explaining a method of calculating a distance to a preceding vehicle.

FIG. 6 is a diagram for explaining control of a headlamp irradiation direction in a road surface processing mode.

FIG. 7 is a flow chart for explaining the operation of the present invention.

[Explanation of symbols]

 1 Road condition recognition unit 2 Headlight 2A Headlight drive unit 3 Control unit 11 CCD camera 12 Vehicle speed sensor 23 Light bulb 24 Main reflecting mirror 25 Sub-reflecting mirror 31 Controller 32 Motor driver

Claims (1)

[Claims] 1. An image pickup means for picking up an image of a road condition in front of a vehicle, a headlight drive means for changing a light distribution characteristic by changing an irradiation direction of a part of a headlight light of the vehicle, and the image pickup. In a headlight automatic light distribution device, which comprises a control means for recognizing a road condition based on an image pickup signal of the means and drivingly controlling the headlight driving means, the control means is at least ahead of a white line on a road ahead of the vehicle. A control for driving the headlight driving means based on the recognized white line, which is configured to recognize the vehicle,
A headlamp automatic light distribution device for a vehicle, characterized in that a control for driving a headlamp driving means based on the recognized preceding vehicle is selectable.