JP2007076429A - Head lamp system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a head lamp system for enabling control of irradiation characteristics in real time by quickly determining a light source of another vehicle or a reflected light of an own vehicle. <P>SOLUTION: The head lamp system comprises a control unit (CPU) 1 for generating timing signals at arbitrary time intervals; a lamp control part 2 for turning on/off head lamps LL and RL of the own vehicle based on the timing signals; a camera control part 4 for imaging the front of the own vehicle with a camera 3 based on the timing signals; and an image processing part 5 for detecting a high-luminance part in an image imaged by the camera 3. The camera control part 4 performs imaging when the lights are turned off. The control unit 1 determines another vehicle, such as a preceding vehicle or an oncoming vehicle, based on the high-luminance part detected by the image processing part 5. When another vehicle is determined, the lamp control part 2 is controlled so that head lamps have irradiation characteristics preventing dazzlement of another vehicle. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a headlamp system for controlling lighting of a headlamp of a vehicle such as an automobile, and more particularly to control irradiation characteristics of a headlamp of the own vehicle in real time and to safely drive the own vehicle and other vehicles. It relates to the secured headlamp system.

  From the standpoint of safe driving of an automobile, an illumination characteristic in which the brightness of the headlamp is high and the illumination range is wide is preferable. However, such an illumination characteristic increases the risk of dazzling other vehicles such as an oncoming vehicle and a preceding vehicle. In recent years, in order to satisfy these conflicting requirements, a headlamp system has been proposed in which the irradiation characteristics during normal driving are enhanced while the irradiation characteristics are limited when another vehicle approaches. For example, in Patent Document 1, a bright area with high brightness corresponding to a headlamp or tail lamp of another vehicle is detected from an image obtained by imaging the front of the own vehicle with a camera, and the direction of the bright area is obtained to determine the direction of the bright area. Dazzling other vehicles is prevented by controlling the irradiation characteristics of the car headlamps. In the technique of this patent document 1, since it is not premised that the bright area in the image is a light source other than another vehicle such as a street lamp, the irradiation characteristics are limited even when the bright area by the street lamp is recognized. There are cases where the irradiation characteristics of the own vehicle are restricted more than necessary. On the other hand, Patent Document 2 performs signal processing on an image obtained by imaging, and performs a required calculation so that a bright area in the image is either a street light or a light source (lamp light) of another vehicle. A technique for determining whether or not the irradiation characteristics of the vehicle are not unnecessarily restricted has been proposed. As this signal processing, the captured image is binarized to extract a contour line, a pair having symmetry is extracted from the size of the bright region, and when this symmetry can be traced, these are extracted. This is a technology for obtaining the distance between vehicles as a light source of another vehicle and recognizing a preceding vehicle and an oncoming vehicle by a change in the distance between vehicles.

Patent Document 3 discloses a technique for determining whether a bright region in a captured image is a light source of another vehicle, or whether light from the light source of the own vehicle is reflected light reflected by a road sign or the like. Is described. In this technique, when a bright area is detected in the image, the light source of the own vehicle is dimmed, and when the brightness of the bright area decreases following the correlation, the correlation between the bright area and the light source of the own vehicle is established. And the bright area is determined as the reflected light of the own vehicle.
JP 2003-267125 A JP-A-8-166221 Japanese Patent No. 3568210

  In the technique of Patent Document 2, in order to determine a bright region of an image captured by a camera as a light source of another vehicle, it takes too much time for signal processing for performing the determination, and it is difficult to control real-time irradiation characteristics. In order to realize this, it is necessary to provide a high-accuracy camera and a high-speed CPU for performing processing at high speed, which causes high costs. On the other hand, the technique of Patent Document 3 is effective in avoiding high costs because it is only necessary to determine the correlation between the two by measuring the brightness of the bright area when the light source of the vehicle is dimmed. . However, even in the technique of Patent Document 3, the light area of the own vehicle is dimmed and then the bright area of the image captured by the camera is determined again to determine whether the light is the reflected light of the own vehicle or the light source of the other vehicle. Therefore, it takes time to perform this determination, and it is difficult to control the irradiation characteristics in real time.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a headlamp system that can control irradiation characteristics in real time by quickly determining the light source of another vehicle and the reflected light of the own vehicle.

  The present invention includes a control device that generates timing signals at arbitrary time intervals, a lamp control unit that turns on and off the headlamps of the host vehicle based on the timing signals, and a camera in front of the host vehicle based on the timing signals. A camera control unit that captures an image, and an image processing unit that detects a high-luminance portion in the image captured by the camera. The camera control unit captures an image with the camera when the headlamp of the host vehicle is turned off, and the control device Determines other vehicles such as preceding cars and oncoming vehicles based on the high-intensity part detected by the image processing unit, and when other vehicles are determined, controls the lamp control unit to dazzle other vehicles in the headlamp illumination characteristics It is characterized in that it is configured to control to a characteristic that does not.

  Here, the control device preferably generates the timing signal at random time intervals. In addition, the control device is configured to determine the high luminance part as another vehicle based on the detected luminance of the high luminance part, position change in the image, or the like. In addition, the lamp control unit is configured to turn off the headlamp for a predetermined short time in response to the timing signal and dimm the headlamp when the control device determines another vehicle.

  According to the present invention, since the front image captured by the camera of the own vehicle is an image when the headlamp of the own vehicle is turned off, the light emitted from the headlamp of the own vehicle is a road sign or the like. There is no high-luminance part due to the reflected light reflected at. Therefore, the control device can determine that the high-intensity part in the image is the light source of the other vehicle, and does not require image processing for removing the high-intensity part by reflected light as in the past, or the high-intensity part is reflected light. Therefore, it is not necessary to control the lamp control unit in order to determine that As a result, the time required for image processing for determining other vehicles and related processing can be shortened, and the time required to control the irradiation characteristics of the headlamp of the own vehicle to prevent dazzling for other vehicles can be shortened. In addition, lamp control in real time becomes possible.

  Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a conceptual configuration diagram of an embodiment in which the present invention is applied to an automobile headlamp system. The left and right headlamps LL, RL of the car CAR are configured by lamps using light emitting elements such as LEDs (light emitting diodes) such as LEDs (light emitting diodes) that rise and fall quickly when turned on and off. These headlamps LL , RL is connected to a lamp control unit 2, and the lamp control unit 2 is configured to turn on the headlamps LL, RL, or to reduce or turn off the lights. The car CAR includes a camera 3 including a CCD image pickup device that picks up the front of the vehicle, a camera control unit 4 that controls the image pickup timing of the camera 3, and an image picked up by the camera 3. An image processing unit 5 is provided. As will be described later, the image processing unit 5 is capable of recognizing a bright area in a captured image and detecting the brightness (brightness) of the bright area. In addition, the lamp control unit 2, the camera control unit 4, and the image processing unit 5 are connected to a CPU (central processing unit) 1. The CPU 1 turns on and off the headlamps LL and RL by the lamp control unit 2. At the same time, the camera control unit 4 controls the imaging timing of the camera 3, and further determines the presence of other vehicles around the host vehicle based on the output of the image processing unit 5 that has processed the image captured by the camera 3. Is configured to do.

  FIG. 2 is a block diagram showing the configuration of the CPU 1, lamp control unit 2, camera control unit 4, and image processing unit 5. The CPU 1 includes a random number generator 11 that generates random numbers, and a timing signal generator 12 that generates random timing signals by arranging the generated random numbers on a time axis. To the camera control unit 4. The lamp control unit 2 performs control to turn off the headlamps LL and RL for a very short time when a timing signal is input. The camera control unit 4 performs a release operation (imaging operation) in the camera 3 when a timing signal is input. Further, the CPU 1 includes a determination unit 13 that determines another vehicle such as a preceding vehicle or an oncoming vehicle based on a high-intensity unit detected by image processing described later in the image processing unit 5. Moreover, the irradiation characteristic control part 14 into which the determination result in the said determination part 13 is input is provided, This irradiation characteristic control part 14 is the irradiation characteristic of headlamps LL and RL by the said lamp control part 2, and each lamp here. To control the light intensity.

  Control of the headlamp irradiation characteristics by the headlamp system having the above configuration will be described with reference to the main flowchart of FIG. When a timing signal is output from the timing signal generator 12 of the CPU 1 (S101), the lamp control unit 2 instantaneously turns off the headlamps LL and RL in response to the timing signal (S102). It should be noted that this time for turning off the light is a short time that cannot be determined by the human eye to be turned off, and is set in advance. In response to the timing signal, the camera control unit 4 releases the camera 3 to image the front of the vehicle (S103). Therefore, imaging is performed when the head lamps LL and RL are both turned off by the lamp control unit 2. FIG. 4A is a timing chart showing that the headlamps LL and RL are turned off at random time intervals, and imaging by the camera 3 is performed at the turn-off timing.

  When the image is captured by the camera 3 in this way, the image processing unit 5 uses the captured image to detect a high-intensity part in the image (S104), and determines another vehicle for the detected high-intensity part. The process to perform is executed (S105). FIG. 5 is a flowchart of the high luminance portion detection step S104, and FIG. The image processing unit 5 divides the entire image V captured by the camera 3 into a large number of blocks as a predetermined matrix configuration, and detects the luminance of each block (S201). In this example, it is assumed that a high luminance part P1 by the light source of the preceding vehicle and a high luminance part P2 by the light source of the oncoming vehicle are imaged in the image V. Then, the average brightness of all the blocks is calculated and set as a threshold value (S202), and the individual brightness of each block is compared with the threshold value (S203) to detect a block in which a high brightness portion exists. (S204). The brightness of each block can be detected at the light and dark levels in the image, and the high brightness portion can be detected by comparing the light and dark levels with each other. The detected block having the high luminance portion is recorded in the memory (S205). Next, the same high-luminance portion is detected for the image shown in FIG. 6B captured at the next timing, and sequentially recorded in the memory (S205). As will be described later, since the headlamps LL and RL of the own vehicle are turned off when the image is captured by the camera 3, the light emitted from the headlamps LL and RL of the own vehicle is reflected by a road sign or a fixed object. Therefore, there is no high luminance part due to the reflected light that appears in the image. In addition, since the luminance portion having a luminance lower than the middle, such as street lamps and house lighting, is removed by the above-described averaging process, it is not detected as a high luminance portion.

  Next, in the determination step S105, the CPU 1 determines whether the high-intensity part existing in the image recorded in the memory is the light source of the preceding vehicle or the oncoming vehicle. In this determination, as shown in FIGS. 6A and 6B, the determination is made based on the high-intensity portions P1 and P2 of a plurality of images captured continuously. In this case, it is preferable to associate whether the high-luminance portion in each image is due to the same target light source, and this association is, for example, a high-luminance in each image when a plurality of images are temporally compared. This can be done by detecting the relative position change of the part. That is, among the high-intensity parts existing in a plurality of temporally preceding and following images, the high-intensity part P1 with a small positional change is estimated to have a substantially constant distance between the host vehicle and the preceding vehicle. The high luminance part P1 is determined to be a light source such as a tail lamp of a preceding vehicle. In addition, the high-intensity part P2 that moves to the right or lower right of the screen at a very high speed in a plurality of images and changes in the luminance direction in accordance with the movement is estimated to be a light source that passes by the own vehicle. Therefore, it is determined that the high brightness portion P2 is a light source such as a headlamp of an oncoming vehicle.

  After determining the other vehicle, the irradiation characteristic control 106 is performed. In this irradiation characteristic control S106, when it is determined that the high-luminance part is a preceding vehicle, the headlamps LL and RL of the own vehicle are dimmed to a predetermined luminous intensity. That is, in the case of a preceding vehicle, there is less glare due to the headlamps LL and RL of the own vehicle than in the case of an oncoming vehicle. Thereby, while reducing the luminous intensity of the headlamps LL and RL of the own vehicle to such an extent that the preceding vehicle is not dazzled, the illumination in front of the own vehicle can be maintained at the brightness required for safe driving. Further, when it is determined that the light source is the oncoming vehicle, the light reduction amount of the headlamps LL and RL of the own vehicle is made larger than that for the preceding vehicle. Thereby, the dazzling with respect to an oncoming vehicle is prevented reliably. Although the light in front of the host vehicle becomes dark due to this dimming, other vehicles can be confirmed by the light source of the oncoming vehicle, and safe driving is ensured with the minimum brightness required.

  Thus, since the image captured by the camera 3 mounted on the host vehicle is an image captured at the timing when the headlamps LL and RL of the host vehicle are turned off, the image is emitted from the headlamps LL and RL of the host vehicle. There is no high luminance part due to the reflected light in which the emitted light is reflected by a road sign or the like. For this reason, the CPU 1 can determine that the high-luminance portion in the image detected by the image processing unit 5 is the light source of another vehicle, and thus there is no need for image processing for removing the high-luminance portion due to reflected light as in the prior art. Or, it is not necessary to control the lamp control unit to determine that the high-intensity part is reflected light, thereby reducing the time required for image processing and the time required for determination. In order to prevent dazzling other vehicles, it is possible to control the irradiation characteristics of the headlamp of the own vehicle in real time.

  Here, when the oncoming vehicle is equipped with the same headlamp system, the light source of the other vehicle is imprinted as a high brightness part in the image captured by the own vehicle when the imaging timing of the own vehicle and the oncoming vehicle coincide. There is a risk that the headlamp system of the embodiment will not function properly. However, in the headlamp system of the embodiment, as shown in FIG. 4A, the headlamps LL and RL are turned off and the imaging timing of the camera 3 is based on a randomly generated timing signal. As shown in FIG. 4B, the headlamp extinguishing timing and the camera imaging timing of the oncoming vehicle rarely match the headlamp extinguishing timing and imaging timing of the host vehicle, and the headlamp has a probability close to 100%. The system operates normally.

  In addition, as shown in the timing Tx of FIGS. 4A and 4B, there is a situation in which the turn-off of the own vehicle and the oncoming vehicle coincide with each other by chance, and the light source of the oncoming vehicle is imprinted as a high luminance part. Even when an image that does not fall is captured, the headlamp system of the embodiment detects each high-brightness part of a plurality of continuously captured images and determines other vehicles, so that the high-brightness part is copied. It is possible to determine the oncoming vehicle from the high-intensity part existing in the images before and after the image not inserted.

  In addition, when a random timing signal is generated, a state in which the time interval between the turn-off and the imaging timing is extremely short may occur continuously. In this case, the state in which the headlamp is turned off may be detected with the naked eye. Therefore, the CPU 1 may be configured not to output the timing signal unless the time interval is not less than a predetermined time. Further, the timing signal may be a timing signal that is generated periodically instead of using a random number as in the embodiment as long as measures are taken so that the timing with other vehicles does not match.

  In addition, when a state in which the high luminance portion does not exist over a plurality of continuous images among a plurality of captured images continues, there is no preceding vehicle or oncoming vehicle immediately before the host vehicle. Therefore, the lamp control unit 2 may be turned off and the camera control unit 4 may be stopped for a predetermined time set in advance regardless of the timing signal.

  In the embodiment, the image processing unit divides the captured image into a plurality of blocks to detect the high-intensity part and its movement, but it is a method that enables high-speed and high-precision processing with fewer processing steps. If there is, it is not limited to the system of the embodiment. For example, the distance and direction of the movement may be obtained by vector calculation of the position change of the high luminance part. Even with such a method, the number of processing steps is small and high speed processing is possible.

  In the example, since the headlamp is turned off at a high speed so that it cannot be seen with the naked eye, the headlamp is composed of light emitting elements such as LEDs so as to be able to cope with this, but the headlamp is turned off instantaneously. It goes without saying that the headlamp may be composed of a light source other than the light emitting element as long as it can be turned on. Further, in the present invention, it is sufficient that a high-luminance portion is not generated due to the reflected light of the headlamp light of the own vehicle in the image captured by the camera, so that an image similar to that when the headlamp is turned off when captured by the camera is obtained. If it is a thing, you may make it reduce to a predetermined level instead of turning off a headlamp, when imaging with a camera.

  In the embodiment, as control of the headlamp illumination characteristics when the other vehicle is determined, the light intensity of the headlamp is reduced, but the illumination characteristics are controlled in a direction to prevent dazzling the other vehicle. If so, the headlamp may be temporarily turned off, or the irradiation direction and irradiation range of the headlamp may be controlled. For example, in the case of the irradiation direction, the irradiation direction is deflected stepwise to the left. In the case of the irradiation range, the irradiation range in the right direction may be narrowed stepwise.

It is a conceptual diagram of the system of this invention. It is a block block diagram of the system of this invention. It is a flowchart which shows the control flow of this invention. It is a figure which shows the light extinction of the own vehicle and another vehicle (opposite vehicle), and an imaging timing. It is a flowchart of a high-intensity detection step. It is a figure explaining the high-intensity part in the imaged image.

Explanation of symbols

1 CPU
2 Lamp control unit 3 Camera 4 Camera control unit 5 Image processing unit LL, RL Headlamp CAR Car

Claims (4)

  A control device that generates a timing signal at an arbitrary time interval, a lamp control unit that turns on and off the headlamp of the host vehicle based on the timing signal, and a camera that images the front of the host vehicle based on the timing signal A control unit, and an image processing unit that detects a high-luminance part in an image captured by the camera, wherein the camera control unit performs imaging with the camera when the headlamp of the host vehicle is turned off, and the control device The other vehicle such as the preceding vehicle or the oncoming vehicle is determined based on the high luminance portion detected by the image processing unit, and when the other vehicle is determined, the lamp control unit is controlled to determine the irradiation characteristics of the headlamp. A headlamp system that is configured to be controlled so as not to be dazzled.   The headlamp system according to claim 1, wherein the control device generates a timing signal at random time intervals.   3. The headlamp system according to claim 1, wherein the control device determines the high-luminance portion as another vehicle based on the detected luminance of the high-luminance portion, a position change in the image, or the like. 2. The lamp control unit according to claim 1, wherein the lamp control unit turns off the headlamp for a predetermined short time in response to the timing signal, and dims the headlamp when the control device determines another vehicle. 4. The headlamp system according to any one of 3.

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