JP2004161082A - Light distribution controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light distribution controller capable of suitably adjusting an irradiation range of a headlight, without generating glare to a driver of a preceding vehicle and an oncoming vehicle. <P>SOLUTION: The light distribution controller comprises a vehicular detecting means for detecting the preceding vehicle and the oncoming vehicle, and a light distribution amount calculating means for calculating the light distribution amount of the headlight independently in right and left sides on the basis of information from the vehicular detecting means, so that the strength of a high beam and a low beam of the right and left headlights can be controlled independently in the right and left sides. Headlight control can be carried out at low cost, because an optical axis changing means is not used. In addition to the structure, a road information detecting means for detecting road information in front of an own vehicle, and a headlight optical axis changing means capable of changing the optical axis of the headlight are provided, so that in addition to strength control of the high beam and the low beam of the headlight, the optical axis of the headlight can be controlled in a lateral and vertical directions. Consequently, suitable light distribution control can be carried out. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a light distribution control device for headlights, and more particularly, to a light distribution control device that controls headlights independently from left and right based on the state of a preceding vehicle or an oncoming vehicle and road information.
[0002]
[Prior art]
The headlights on the vehicle can be switched between a high beam and a low beam in two stages. During traveling at night, it is common to use a high beam when there is no preceding vehicle or oncoming vehicle, and to use a low beam when there is a preceding vehicle or oncoming vehicle so that glare does not occur to the driver of the other party. However, it cannot be said that an optimum field of view can be secured only by these two-stage switching. Therefore, Japanese Patent Application Laid-Open
Japanese Patent Application Laid-Open No. 295601 proposes a method of setting a boundary between a portion where a headlight is irradiated to a preceding vehicle and a portion where the light is not irradiated to a preceding vehicle at a predetermined height or less.
[0003]
[Patent Document 1]
JP-A-6-295601
[Problems to be solved by the invention]
However, in the above-described control, it is difficult to detect a boundary line for a vehicle that is farther than the host vehicle, and thus the control may be unstable. Furthermore, since the left and right headlights are moved in the same direction, when the preceding vehicle is traveling on one side, the irradiation range on the opposite side of the preceding vehicle is not optimal. Further, since the optical axis in the horizontal direction is not controlled, it is not possible to control the optical axis corresponding to the curve. In addition, when only the intensity control of the high beam and the low beam is sufficient, a mechanism for adjusting the optical axis of the headlight is required, so that the cost increases. The present invention has been made in view of the above problems, and has a light distribution control apparatus and method capable of optimally adjusting the irradiation range of a headlight without causing glare to a driver of a preceding vehicle or an oncoming vehicle. The purpose is to provide.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, a light distribution control device according to the present invention includes a vehicle detection means for detecting a preceding vehicle or an oncoming vehicle, and a light distribution control device for independently calculating left and right light distribution amounts of headlights based on information from the vehicle detection means. It is characterized by having a light amount calculating means. With this configuration, the intensity of the high beam and the low beam of the left and right headlights can be controlled independently of the left and right, and the headlight can be controlled at low cost because the optical axis changing means of the headlight is not used.
[0006]
Furthermore, in addition to the above-described configuration, a road information detecting unit that detects road information ahead of the vehicle and a headlight optical axis changing unit that can change the optical axis of the headlight are provided, so that a high beam and a low beam of the headlight are provided. In addition to the intensity control described above, the optical axis of the headlight can be controlled left, right, up and down, and optimal light distribution control can be performed.
[0007]
Further, the above object is a light distribution control method for controlling light distribution of a plurality of lights installed in a vehicle, wherein the light distribution control method detects an object in a certain direction, and performs light distribution of the plurality of lights based on the detected information. Is individually controlled.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
[First embodiment]
Hereinafter, an embodiment of a light distribution control device that controls the intensities of a high beam and a low beam of a headlight independently of left and right according to the present invention will be described in detail with reference to the drawings.
[0009]
FIG. 1 is a control block diagram showing a basic configuration of the light distribution control device of the present embodiment. This apparatus comprises a vehicle detecting means 1 for detecting a preceding vehicle or an oncoming vehicle, and a light distribution calculating means 4 for calculating left and right headlight distribution amounts independently based on information from the vehicle detection means. A vehicle speed etc. detecting means 7 is provided. The vehicle detecting means 1 obtains the vehicle width of the preceding vehicle or the oncoming vehicle by the vehicle position calculating means 3 based on the information obtained from the imaging device 2, and calculates the relative angle or relative distance of the preceding vehicle or the oncoming vehicle with respect to the own vehicle. Things. The light distribution calculating means 4 calculates the high beam and low beam intensities of the left and right headlights 5, 6 based on the information obtained by the vehicle detecting means 1 and the own vehicle speed and the steering position which are information from the vehicle speed etc. detecting means 7. The right and left headlights 5 and 6 are respectively controlled by voltage control or PWM control.
[0010]
FIG. 2 illustrates how the vehicle detecting means 1 calculates the vehicle width of the preceding vehicle and calculates the relative angle and relative distance to the own vehicle. First, the image of the recognition target scene 8 is captured by the imaging device 2, and then the recognition target scene 8 is converted into the lateral edge image 9 by the vehicle position calculation means 3. Then, a lump of lateral edges can be extracted as the vehicle region 11. Since the center line of the host vehicle and the direction line of the preceding vehicle can be obtained, the relative angle θ of the preceding vehicle, which is the angle formed by the center line and the preceding vehicle direction line, can be calculated. Further, since the vehicle width W in the image can be obtained from the vehicle area 11, if the focal length of the lens is f, the actual vehicle width is L, and the relative distance from the preceding vehicle is X,
f: W = X: L Equation 1
Holds, the focal length f is known, and the relative distance X can be calculated when the actual vehicle width L is a fixed value (eg, 1.8 m 2). Also, taking advantage of the feature that the brightness of the tail lamp of the preceding vehicle and the headlight of the oncoming vehicle is brighter than the brightness of the road, etc. Image. Therefore, when the shutter is stopped down to capture the recognition target scene 8, a shutter-down image 10 is generated. The preceding vehicle direction line and the vehicle width W can be obtained from the pair of tail lamps 12, and the relative angle θ and the relative distance X can be obtained as in the case of the lateral edge image 9. When the preceding vehicle is distant, there is a possibility that the edge may not easily appear, so that the vehicle region 11 of the lateral edge image 9 may not be extracted. Therefore, when the preceding vehicle is distant, the shutter narrowed image 10 is used, and when the preceding vehicle is near, the lateral edge image 9 or the shutter narrowed image 10 is used, so that the leading vehicle can be accurately moved from near to far. Can be extracted.
[0011]
FIG. 3 is a graph for obtaining the target voltage value of the right high beam from the relative angle θ and the relative distance X obtained by the vehicle detecting means 1. When the voltage value of the light is low, it is dark, and when it is high, it is bright. The relative angle θ is positive in the clockwise direction from the vehicle center line. The graph of FIG. 3 is drawn when the relative distance is 0 m, 100 m, 200 m, and 300 m, but is smoothly connected at other relative distances. The headlight becomes darker as it goes farther and has a characteristic of irradiating a wider range. Therefore, as the relative distance becomes longer, the right high beam target voltage is increased and the low voltage range is further increased. Also, due to the difference in the light distribution range of the left and right headlights, the left and right headlights are not symmetrical about the relative angle 0, and the voltage is increased faster when the relative angle θ is negative than when it is positive. The target voltage value can be similarly determined for the left high beam and the left and right low beams.
[0012]
The control state of the present apparatus will be described based on the flowchart shown in FIG. First, in step 101, it is detected whether a preceding vehicle or an oncoming vehicle exists based on the edge image or the shutter-down image. If there is a preceding vehicle or an oncoming vehicle, the process proceeds to step 102, where the relative distance and relative angle of the preceding vehicle or oncoming vehicle are calculated. Then, in step 103, since the relative distance, the relative angle, and the target voltage have the relationship shown in FIG. 3, the target voltages of the high beam and low beam of the left and right headlights are determined. If no preceding or oncoming vehicle is detected in step 101, the target voltage of the left and right headlights is set to the maximum for the high beam and to the minimum for the low beam in step 104. Then, in step 105, the target voltage is output to each of the left and right headlights.
[0013]
According to the first embodiment, the relative distance and the relative angle of the preceding vehicle or the oncoming vehicle can be calculated with high accuracy from the video information obtained from the imaging device 2. By setting the target voltage for each of the left and right headlights, the intensity of the high beam and low beam of the left and right headlights can be controlled independently for the left and right. Furthermore, since the optical axis changing means of the headlight is not used, the headlight can be controlled at low cost.
[0014]
[Second embodiment]
Next, an embodiment of a light distribution control device that controls the optical axes of a high beam and a low beam of a headlight in right, left, up, and down directions will be described.
[0015]
FIG. 5 is a control block diagram showing a basic configuration of the light distribution control device of the present embodiment. In addition to the control block diagram of the first embodiment (see FIG. 1), the present device further includes a road information detecting means 13 for determining the position where the host vehicle travels, and the left and right headlights based on the position information or steering information where the host vehicle travels. Left and right headlight optical axis changing means 14 and 15 capable of changing the axis are provided. Next, the vertical movement of the optical axis will be described. The vehicle detecting means 1 calculates the relative distance and the relative angle of the preceding vehicle or the oncoming vehicle with respect to the own vehicle as in the first embodiment, and the light distribution calculating means 4 calculates the relative distance and the relative angle obtained by the vehicle detecting means 1. Based on this information, the vertical movement amount of the optical axis of the left and right headlights can be calculated from the graph in FIG. 3 in which the right high beam target voltage value is the right headlight vertical optical axis movement amount. Based on the vertical optical axis movement amount, the optical axis changing means 14 and 15 of the left and right headlights control the axis of the light. Next, the movement of the optical axis in the left-right direction will be described. When the road information detecting means 13 performs Hough transform or the like on the road image input from the imaging device 2, the own vehicle traveling lane shown in FIG. 6 can be detected. Based on the detection result of the lane, the travel distance 17 of the host vehicle, which is the difference between the travel point 16 50 m ahead and the current travel position, is calculated. Next, when the amount of movement of the steering is equal to or more than a predetermined value, the light distribution amount calculation means 4 determines that the amount of movement of the optical axis in the left-right direction is positive when the steering wheel is turned right, and Calculate as positive when the axis is tilted. When the amount of movement of the steering is equal to or less than a certain value, the amount of movement of the optical axis in the left-right direction is calculated as a positive value when moving right 50 m ahead of the own vehicle from the upper graph of FIG. The optical axis control of the right and left headlights is performed by the optical axis changing means 14 and 15 based on the moving amount of the optical axis in the left and right direction.
[0016]
Next, a control state of the present apparatus will be described based on a flowchart shown in FIG. First, in step 201, a lane in which the host vehicle is traveling is detected using Hough transform or the like with respect to a road image input from the imaging device 2, and a traveling point 50 m ahead shown in FIG. Is calculated from the position of the own vehicle. Next, in steps 202, 203, 204, and 205, the amount of vertical optical axis movement of the left and right headlights is calculated from the relative distance and relative angle of the preceding vehicle or oncoming vehicle, as in the first embodiment. Next, when the amount of steering movement detected by the vehicle speed etc. detecting means 7 in step 206 is equal to or smaller than a predetermined value, the process proceeds to step 207. If the calculation of the moving amount M of the host vehicle is successful in step 207, the process proceeds to step 208, and the moving amount of the headlight optical axis in the left-right direction is set based on the upper graph in FIG. If the calculation of the movement amount M of the host vehicle has not been successful in step 207, the movement of the headlight optical axis in the left-right direction is set as the center in step 209. If the amount of movement of the steering is equal to or more than the predetermined value in step 206, the amount of movement of the headlight optical axis in the left-right direction is set based on the lower graph of FIG. In step 211, the left and right headlight optical axis changing means 14 and 15 control the headlights in the vertical and horizontal directions.
[0017]
According to the second embodiment, the relative distance and the relative angle of the preceding vehicle or the oncoming vehicle can be calculated with high accuracy from the video information obtained from the imaging device 2, and the position of the own vehicle in the future 50m ahead can be calculated. The own vehicle movement amount M, which is the difference between the current traveling positions, can be calculated. The upper, lower, left and right optical axes of the left and right headlights can be optimally controlled based on this information and the steering information.
[0018]
In the present embodiment, the distance for calculating the own vehicle movement amount M is set to 50 m. However, this is merely an example, and it is possible to change the distance to another distance. good.
[0019]
【The invention's effect】
As can be understood from the above description, the light distribution control device of the present invention can accurately determine the relative distance and the relative angle of the preceding vehicle or the oncoming vehicle detected by the detection device such as the imaging device installed in the own vehicle. It can calculate the intensity of the high beam and low beam of the left and right headlights independently on the left and right based on this calculation result, and perform optimal light distribution control without causing glare to the driver of the oncoming vehicle or the preceding vehicle Can be. Further, a low-cost apparatus can be provided because an actuator or the like required for changing the optical axis is not required. Furthermore, by adding road information detecting means for detecting road information ahead of the vehicle and optical axis changing means for headlights, it becomes possible to independently control the upper, lower, left and right optical axes of the left and right headlights. Alternatively, optimal light distribution control can be performed without causing glare to the driver of the preceding vehicle.
[Brief description of the drawings]
FIG. 1 is a basic control block diagram of an embodiment of a first embodiment of a light distribution control device of the present invention.
FIG. 2 is a diagram showing an example for calculating a relative angle and a relative distance of a preceding vehicle.
FIG. 3 is a graph showing an example for obtaining a target voltage value of a right high beam.
FIG. 4 is a control flowchart for determining high-beam and low-beam voltages of left and right headlights from information on a preceding vehicle or an oncoming vehicle according to the first embodiment.
FIG. 5 is a basic control block diagram of an embodiment of a second embodiment of the light distribution control device of the present invention.
FIG. 6 is a diagram showing an example for grasping the moving amount of the own vehicle.
FIG. 7 is a graph showing an example for calculating the amount of movement of the optical axis in the left-right direction.
FIG. 8 is a control flowchart for determining the up / down / left / right control amounts of the left and right headlights from the own vehicle movement amount, the preceding vehicle or oncoming vehicle information, and the steering movement amount in the second embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Vehicle detection means, 2 ... Imaging device, 3 ... Vehicle position calculation means, 4 ... Light distribution amount calculation means, 5 ... Left headlight, 6 ... Right headlight, 7 ... Vehicle speed etc. detection means, 8 ... Scene to be recognized, 9: lateral edge image, 10: shutter aperture image, 11: vehicle area, 12: pair of tail lamps, 13: road information detecting means, 14: left headlight optical axis changing means, 15: right headlight optical axis changing means , 16... A traveling point 50 m ahead, 17...

Claims (10)

Light distribution control comprising: vehicle detection means for detecting a preceding vehicle or an oncoming vehicle; and light distribution calculation means for calculating the left and right light distribution of headlights of the vehicle independently based on information from the vehicle detection means. apparatus. 2. The light distribution control device according to claim 1, wherein the light distribution amount calculation means calculates the intensities of the high beam and the low beam of the left and right headlights. A vehicle detecting means for detecting a preceding vehicle or an oncoming vehicle; a road information detecting means for detecting road information ahead of the own vehicle; and a light distribution amount of a headlight based on information of the vehicle detecting means and the road information detecting means. A light distribution control device comprising: a light distribution amount calculation means for independently calculating; and a headlight optical axis changing means for changing an optical axis of a headlight. 4. The light distribution control device according to claim 3, wherein the light distribution calculation unit calculates the intensities of the high beam and the low beam of the left and right headlights and the optical axis direction of the left and right headlights. The light distribution control device according to any one of claims 1 to 4, wherein the vehicle detection device of the vehicle detection unit is an imaging device. 5. The light distribution control device according to claim 3, wherein the road information detecting device of the road information detecting means is an image pickup device. 7. The light distribution control device according to claim 1, wherein the information obtained by the vehicle detection means calculates a relative position of the preceding vehicle or the oncoming vehicle with respect to the own vehicle from known size information of the oncoming vehicle. 7. The system according to claim 1, wherein the information obtained by the vehicle detection means calculates a relative position with respect to the own vehicle from a vehicle width, a left and right light width, and a number plate width of a preceding vehicle or an oncoming vehicle. Light control device. A light distribution control method for controlling light distribution of a plurality of lights installed in a vehicle,
Detect an object in a certain direction,
A light distribution control method for individually controlling the light distribution of the plurality of lights based on the detected information. In claim 8,
A light distribution control method, wherein the object is detected by analyzing a captured image.

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