JP5251680B2 - Lighting control apparatus and program - Google Patents

Description

  The present invention relates to a lighting control device and a program, and more particularly, to a lighting control device and a program capable of setting an appropriate lighting region based on an image obtained by photographing a predetermined region.

  Conventionally, the high luminance part is detected from the image captured when the light is turned off, the other vehicle such as the preceding vehicle or the oncoming vehicle is determined based on the detected high luminance part, and the other vehicle is not dazzled when the other vehicle is determined. A headlamp system for controlling a headlamp has been proposed (see Patent Document 1).

  Also, an automobile head that detects the position of a light spot in an image photographed by a camera and controls the headlight so as to irradiate with a pattern that reduces the amount of light in a predetermined area above the detected light spot. A light control device has been proposed (see Patent Document 2).

  Also, dangerous objects for driving a vehicle are determined as dangerous objects using captured images and radars, and each of them illuminates different areas and changes the direction of multiple light sources that form a predetermined light distribution pattern as a whole. There has been proposed a vehicle illumination system that controls to illuminate the light (see Patent Document 3).

  In addition, when the degree of separation between the luminance value of the center of gravity of the bright area of the photographed image and the luminance value of the surrounding area exceeds a threshold value, the area centered on the center of gravity is used as a headlight or tail lamp of another vehicle. A pre-illumination device is proposed in which a horizontal line passing through the center of gravity of the true bright region is determined as the upper limit angle of the irradiation range (see Patent Document 4).

JP 2007-76429 A JP 2008-94127 A JP 2006-21631 A JP 2003-267125 A

  However, in the technique described in Patent Document 1, since the high-luminance portion is detected using an image taken when the light is turned off, reflectors such as guardrails, curbs, and bicycles cannot be detected, and the illumination range is appropriately set. There is a problem that it cannot be set to.

  In the technique described in Patent Document 2 and the technique described in Patent Document 4, there is a high possibility that the reflector will be detected in the same manner as the headlight and taillight. In that case, the reflector is located above the reflector. On the other hand, there is a problem in that the amount of light is reduced, and there is a possibility that pedestrians and bicycles may be overlooked because lighting is not sufficiently projected on the sidewalks and roadsides.

  In the technique described in Patent Document 3, since a bicycle or a pedestrian is not necessarily determined as a dangerous object, there is a possibility that illumination light is not projected to a bicycle or a pedestrian that is not determined as a dangerous object. There is a problem. Moreover, since the area where the illumination light should be projected is not limited to the area where the dangerous substance exists, there is a problem that the illumination range may not be set appropriately.

  The present invention has been made in order to solve the above-described problems, and the illumination area can be set so that illumination light is appropriately projected onto an area where the influence of the vehicle illumination has a large effect on the visibility. It is an object to provide a control device and a program.

  In order to achieve the above object, an illumination control device according to the present invention has a photographing means for photographing a target area in front of a vehicle, and projects illumination light in front of the vehicle when turned on, and when turned off. Illuminating means capable of light distribution control for stopping the projection of the illumination light, a lighting image taken by the photographing means when the illuminating means is turned on, and when the illuminating means is turned off The vehicle corresponding to a region including a difference image generation unit that generates a difference image with the extinguished image captured by the imaging unit, and a region including a pixel in which the pixel value of the difference image generated by the difference image generation unit is greater than a difference threshold value Setting means for setting the front area as an illumination area where illumination light should be projected, and illumination light is projected to the illumination area set by the setting means, and illumination light to areas other than the illumination area Is dimmed or flooded It said control means for controlling the light distribution of the illumination means, is configured to include a so as not to.

  Further, the illumination control program of the present invention is an illumination capable of light distribution control for projecting illumination light in front of the vehicle when the computer is turned on and stopping projection of the illumination light when the computer is turned off. A difference image between a lighting image taken by a photographing means for photographing a target area in front of the vehicle when the means is turned on and a light-off image photographed by the photographing means when the lighting means is turned off. A difference image generation means to generate, and an illumination area in which illumination light should be projected in an area in front of the vehicle corresponding to an area including pixels whose pixel values of the difference image generated by the difference image generation means are greater than a difference threshold And setting means for setting the illumination means so that the illumination light is projected to the illumination area set by the setting means and the illumination light is not dimmed or projected to areas other than the illumination area. the light Is a program for functioning as Gosuru control means.

  According to the illumination control device and the program of the present invention, the imaging unit images the target area in front of the vehicle, and the illumination unit projects illumination light in front of the vehicle when turned on and when the illumination unit is turned off. The light distribution is controlled so as to stop the projection of the illumination light. The difference image generating means generates a difference image between a lighting image taken by the photographing means when the lighting means is turned on and a non-lighting image taken by the photographing means when the lighting means is turned off, The setting unit sets a region in front of the vehicle corresponding to a region including a pixel in which the pixel value of the difference image generated by the difference image generating unit is larger than the difference threshold as an illumination region where illumination light is to be projected. Then, the control means controls the light distribution of the illumination means so that the illumination light is projected onto the illumination area set by the setting means, and the illumination light to areas other than the illumination area is not dimmed or projected. .

  As described above, a region in front of the vehicle corresponding to a region including a pixel in which the pixel value of the difference image between the lit image and the unlit image is larger than the difference threshold, that is, a region in which the vehicle lighting has a large influence on the driver's visibility. Since the illumination area is set as the illumination area to be projected, the illumination area can be appropriately set.

  Further, the setting means of the present invention includes a region including a pixel having a pixel value of the difference image equal to or less than the difference threshold and a pixel value of a corresponding pixel in the lit image or the unlit image being equal to or higher than a high luminance threshold. The area above the area in front of the vehicle corresponding to can be excluded from the illumination area and set as an area other than the illumination area. An area in front of the vehicle corresponding to an area including a pixel having a pixel value of a difference image equal to or lower than the difference threshold and a pixel value of the corresponding pixel in the lit image or the unlit image being equal to or higher than the high luminance threshold is a headlight of an oncoming vehicle. Therefore, it can be determined that it is a self-luminous object such as a taillight of a preceding vehicle or a light of a bicycle. Dazzling can be prevented.

  Further, the difference image generation means of the present invention may generate a difference image by correcting a positional shift accompanying a vehicle motion between when the lighting image is captured and when the extinguishing image is captured. it can. Thereby, it is possible to generate a difference image in which a position shift amount in which the position of the photographing target is shifted in the image with the vehicle motion is corrected.

  In order to correct such misalignment due to vehicle motion, the difference image generation means of the present invention captures a plurality of frames of the lit image or the unlit image at different times, and based on the captured images of the plurality of frames. With the optical flow obtained in this way, it is possible to correct the positional shift accompanying the vehicle motion.

  Further, the lighting control device of the present invention can be configured to include a vehicle motion measuring unit that detects at least one of a vehicle speed, an acceleration, and a yaw rate and measures a vehicle motion, and the difference image generating unit includes: Based on the vehicle movement measured by the vehicle movement measuring means, it is also possible to correct a positional shift accompanying the vehicle movement.

  In addition, the illumination control device of the present invention can be configured to include illuminance detection means for detecting the illuminance around the vehicle in time series, and the illuminance detection means performs time series with the illumination means turned off. When the change amount of the detected illuminance is equal to or greater than the illuminance threshold, the control by the control means can be started. As a result, when entering a tunnel or the like with the illumination means turned off during the daytime, etc., the amount of change in the illuminance detected by the illuminance detection means becomes large, and the light distribution control of the illumination means by the control means is performed. Since it is started, the present invention can be applied day and night.

  As described above, according to the illumination control device and program of the present invention, the vehicle illumination is visually recognized by the driver based on the difference image between the lighting image captured when the illumination light is lit and the extinguishing image captured when the illuminating light is extinguished. The effect that the illumination area can be set so that the illumination light is appropriately projected onto the area having a large influence on the property is obtained.

It is a block diagram which shows the structure of the illumination control apparatus which concerns on 1st Embodiment. It is a flowchart which shows the content of the illumination control processing routine in the illumination control apparatus which concerns on 1st Embodiment. (A) Vehicle front image, (B) It is an image figure which shows an example of the set illumination area | region. It is a block diagram which shows the structure of the illumination control apparatus which concerns on 2nd Embodiment. It is a flowchart which shows the content of the illumination control processing routine in the illumination control apparatus which concerns on 2nd Embodiment. It is a block diagram which shows the structure of the illumination control apparatus which concerns on 3rd Embodiment. It is a flowchart which shows the content of the illumination control processing routine in the illumination control apparatus which concerns on 3rd Embodiment. It is a block diagram which shows the structure of the illumination control apparatus which concerns on 4th Embodiment. It is a flowchart which shows the content of the illumination lighting control processing routine in the illumination control apparatus which concerns on 4th Embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the present embodiment, a case where the present invention is applied to an illumination control apparatus that is mounted on a vehicle and controls a headlight based on a captured front image will be described as an example.

  As shown in FIG. 1, the illumination control apparatus 10 according to the first embodiment includes an imaging device 12 including a CCD camera that captures an image in front of the host vehicle, and a head that projects illumination light in front of the vehicle. A light 16 and a computer 18 for controlling the light distribution of the headlight 16 based on the photographed front image are provided. The photographing device 12 is not particularly limited with respect to the number of cameras and the angle of view, and may have an arbitrary configuration. Further, the image output by the photographing device 12 may be either a gray image or a color image.

  The headlight 16 has a configuration in which a plurality of lights are arranged in an array so that illumination light is distributed in various irradiation patterns. Note that a configuration in which the irradiation direction can be changed by a mirror or the like, or a configuration in which an irradiation region can be arbitrarily set by a projector method may be used. When the headlight 16 is turned on, illumination light is projected onto the set illumination area in front of the vehicle. When the headlight 16 is turned off, illumination light projection is stopped. The lighting and extinguishing can be switched at high speed so that it is hardly recognized by the driver or the surrounding people. The front image (lighted image) and the headlight 16 when the headlight 16 is turned on and the headlight 16 are turned off by capturing an image in front of the vehicle with the photographing device 12 in synchronization with the lighting and turning-off timing of the headlight 16. A front image (light-out image) when the camera is in the middle is photographed.

  The computer 18 stores a CPU that controls the entire illumination control apparatus 10, a ROM as a storage medium that stores various programs such as a program of an illumination control processing routine that will be described later, a RAM that temporarily stores data as a work area, and various types of information. The memory includes a memory as storage means, an I / O (input / output) port, and a bus connecting them.

  If the computer 18 is described by function blocks divided for each function realizing means determined based on hardware and software, as shown in FIG. 1, an image input unit 20 for inputting a front image output from the photographing device 12. A difference image generation unit 22 that generates a difference image between a lit image and an unlit image, a self-luminous object recognition unit 24 that recognizes a self-luminous object based on the difference image generated by the difference image generation unit 22, a difference image and recognition Based on the emitted light, the illumination light is projected onto the illumination area setting unit 26 that sets the illumination area where the illumination light from the headlight 16 is to be projected, and the illumination area set by the illumination area setting unit 26. In this way, it can be represented by a configuration including an illumination control unit 28 that controls the light distribution of the headlight 16.

  The image input unit 20 includes, for example, an A / D converter and an image memory that stores image data for one screen.

  The difference image generation unit 22 generates a difference image between the lit image and the unlit image input by the image input unit 20. Since the lighting and extinguishing of the headlight 16 can be switched at high speed, it can be considered that the lighting image and the extinguishing image are taken almost simultaneously.

  The self-luminous object recognizing unit 24 is a pixel in which the pixel value of the difference image generated by the difference image generating unit 22 is equal to or less than the difference threshold, and the pixel value of the corresponding pixel in the lit image or the unlit image is equal to or higher than the high luminance threshold. Is recognized as a self-luminous object such as a headlight of an oncoming vehicle, a taillight of a preceding vehicle, or a bicycle light. When the pixel value of the difference image is equal to or greater than the difference threshold, the luminance change is large between when the headlight 16 is turned on and when the headlight 16 is turned off, and this indicates that the vehicle illumination has a large influence on driver visibility. This region includes a region where there is a reflector that returns the reflected light of the vehicle illumination.

  On the other hand, when the pixel value of the difference image is smaller than the difference threshold value, the luminance change is small between when the headlight 16 is turned on and when the headlight 16 is turned off, indicating that the vehicle lighting has a small influence on the driver's visibility. . This region includes a region such as a distant structure or sky, and a region where the above-described self-luminous object exists. As described above, whether the pixel is a region such as a distant structure or the sky, or a region where a self-luminous object exists is a pixel whose corresponding pixel value in the lit image or the unlit image is equal to or higher than the high luminance threshold value. It can be determined by whether or not it is a region including the pixel. If the pixel value is equal to or higher than the high luminance threshold, it can be determined that the light is a self-luminous object.

  Therefore, a value that can determine whether the influence on the visibility is large or small is set in advance as the difference threshold, and a value that can determine whether or not it is a luminescent object is set in advance as the high luminance threshold.

  The illumination area setting unit 26 is an area including pixels whose pixel values of the difference image are equal to or greater than the difference threshold, and excluding the area above the area recognized as the self-luminous object by the self-luminous object recognition unit 24. Set as. The vehicle front area corresponding to the area including the pixel having the pixel value of the difference image equal to or larger than the difference threshold is an area in which the vehicle illumination has a large influence on the driver's visibility, and therefore is an illumination area to which illumination light should be projected. Set. Furthermore, since it can be assumed that drivers of oncoming vehicles and preceding vehicles and bicycle drivers exist above the region recognized as the self-luminous object, the illumination region is used to prevent dazzling of drivers of these other vehicles. Exclude from Note that self-luminous objects include street lights, building lights, electric signboards, etc., but it is unlikely that there are objects that need to be viewed by drivers such as pedestrians above these objects. There is no problem even if it is excluded from.

  The illumination control unit 28 projects the illumination light of the headlight 16 to the illumination region set by the illumination region setting unit 26, and prevents the illumination light to the region other than the illumination region from being dimmed or projected. Furthermore, the light distribution of the headlight 16 is controlled by adjusting the light projection angle and lighting or extinguishing of each of the plurality of lights. The illumination control unit 28 also performs control to switch on and off of the headlight 16 at the time of shooting the above-described lighting image and extinguishing image in synchronization with the timing of imaging by the imaging device 12.

  Next, an illumination control processing routine in the illumination control apparatus 10 according to the first embodiment will be described with reference to FIG. This routine is performed by the CPU executing the lighting control program stored in the ROM when the vehicle on which the lighting control device 10 is mounted is running on the road with the headlights 16 turned on at night. .

  In step 100, a lighting image in front of the vehicle when the headlight 16 is lit, which is photographed by the photographing device 12, is acquired.

  Next, in step 102, the headlight 16 is turned off instantaneously. Next, in step 104, a turn-off image in front of the vehicle when the headlight 16 is turned off is acquired, and the headlight 16 is turned on again.

  Next, in step 106, a difference image between the lighting image acquired in step 100 and the extinguishing image acquired in step 104 is generated.

  Next, in step 108, the difference image is divided into a plurality of regions by grouping together pixels having the same pixel value or within a predetermined range in adjacent images in the difference image as a group of pixels.

  Next, in step 110, it is determined whether or not the pixel value of the pixel included in the region is larger than the difference threshold for each divided region of the difference image. In addition, when the pixel values of the pixels included in the region are not the same, the determination is performed using values such as an average value, a maximum value, a minimum value, and a mode value of the pixel values of the pixels included in the region. When the pixel value is larger than the difference threshold value, the process proceeds to step 112, and the area is identified as an area where the influence of the vehicle illumination on the driver's visibility is large. On the other hand, if the pixel value is equal to or smaller than the difference threshold value, the process proceeds to step 114, and the area is specified as an area where the influence of the vehicle lighting on the driver's visibility is small. Then, the process proceeds to step 116, and it is determined whether or not the pixel value of the pixel included in the region corresponding to the region in the lit image or the unlit image is equal to or higher than the high luminance threshold. If the pixel value is greater than or equal to the high brightness threshold value, the process proceeds to step 118 and the area is recognized as a self-luminous object.

  Next, in step 120, it is determined whether or not the processing has been completed for all the regions of the difference image. If not, the processing returns to step 110, and the processing is repeated for the next region. Proceeds to step 122.

  In step 122, an area where the own vehicle illumination has a large influence on the driver's visibility and excluding the upper area of the self-luminous object is set as an illumination area. For example, when the lighting image acquired in step 100 is an image as shown in FIG. 3A, an illumination area is set as shown in FIG.

  Next, at step 124, the illumination light is projected onto the illumination area set at step 122, and the headlight 16 is arranged so that the illumination light to areas other than the illumination area is not dimmed or projected. Control the light.

  The above routine is repeated while driving with the headlight 16 turned on. By repeating the above routine, the headlight 16 is turned on and off in steps 100 to 104 repeatedly. This switching between turning on and off is executed at high speed, so that the driver and peripheral Is almost unrecognizable.

  As described above, according to the illumination control device of the first embodiment, the influence of the vehicle illumination on the driver visibility in the region where the pixel value of the difference image between the lit image and the unlit image is larger than the difference threshold. Is specified as a large area and is set as an illumination area where illumination light is to be projected, so that an appropriate illumination area can be set. Further, when the pixel value of the difference image is an area that is equal to or smaller than the difference threshold value and the pixel value of the corresponding pixel of the lit image or the unlit image is equal to or greater than the high luminance threshold value, the area is recognized as a self-luminous object and self-luminous Since the upper side of the object is excluded from the illumination area, it is possible to prevent dazzling the driver of other vehicles.

  Next, a second embodiment will be described. In addition, about the structure and process same as 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  In the illumination control device of the first embodiment, the case where the lighted image and the light-off image are regarded to have been taken substantially simultaneously and the difference image is generated has been described. In the second embodiment, The difference from the first embodiment is that a difference image is generated by correcting the positional deviation from the unlit image. Switching between turning on and off the headlights is done at high speed, so the time difference between when the lit image is taken and when the unlit image is taken is very small, but when the vehicle moves at high speed, etc. Since the position shift due to the vehicle motion during this time is reflected in the difference image, the difference image is corrected to generate a difference image.

  As shown in FIG. 4, the illumination control device 210 according to the second embodiment is configured to include an imaging device 12, a headlight 16, and a computer 218. The computer 218 can be represented by a configuration including a misalignment correction unit 221.

  The misalignment correction unit 221 acquires two frames of the lit image, calculates an optical flow from the lit image of the two frames, and shoots the lit image and then the unlit image based on the calculated optical flow. The vehicle motion up to is calculated, and a lighting image is generated in which the positional deviation associated with the calculated vehicle motion is corrected.

  The difference image generation unit 22 generates a difference image between the lit image and the unlit image whose position shift has been corrected by the position shift correction unit 221.

  Next, an illumination control processing routine in the illumination control apparatus 210 according to the second embodiment will be described with reference to FIG. This routine is performed by the CPU executing the illumination control program stored in the ROM when the host vehicle equipped with the illumination control device 210 is running on the road with the headlights 16 turned on at night. .

  In step 230, a lighting image in front of the vehicle when the headlight 16 is lit, which is photographed by the photographing device 12, is acquired. Let the lighting image acquired here be a lighting image (1).

  Next, in step 102, the headlight 16 is turned off instantaneously. Next, in step 104, a turn-off image in front of the vehicle when the headlight 16 is turned off is acquired, and the headlight 16 is turned on again.

  Next, in step 232, a lighting image when the headlight 16 is turned on is acquired again. Let the lighting image acquired here be a lighting image (2).

  Next, in step 234, an optical flow is calculated using the lit image (1) and the lit image (2). Based on the calculated optical flow, the lit image (1) is captured and then the unlit image is captured. The vehicle motion until it is calculated is calculated, and a lighting image is generated in which the positional deviation accompanying the calculated vehicle motion is corrected.

  Next, in step 236, a difference image between the lighting image whose position shift is corrected in step 234 and the extinguishing image acquired in step 104 is generated. Hereinafter, similarly to the first embodiment, an appropriate illumination area is set based on the difference image, and the light distribution control of the headlight 16 is performed.

  As described above, according to the illumination control apparatus according to the second embodiment, the optical flow is calculated using the lighting image for two frames, and the lighting image is captured based on the calculated optical flow. The position difference is corrected in order to correct the displacement caused by the vehicle movement between when the image is turned off and when the unlit image is captured, and to prevent the difference image from being affected by the displacement caused by the vehicle movement. The illumination area can be set more appropriately based on the image.

  In the second embodiment, the optical flow is calculated from two frames of the lighting image, but may be calculated using an image of three frames or more. Alternatively, the optical flow may be calculated using the unlit image of two or more frames, and the positional deviation may be corrected in the unlit image. In the above routine, a lit image, a lit image, and a lit image are captured in the order of two frames to obtain a lit image for two frames. However, it is sufficient if a plurality of frames of images for calculating the optical flow can be acquired. The order does not matter.

  Next, a third embodiment will be described. In addition, about the structure and process same as 1st and 2nd embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  In the illumination control apparatus of the second embodiment, the case where the optical flow is calculated and the positional deviation between the lighting image and the non-lighting image is corrected to generate the difference image has been described. The embodiment is different from the second embodiment in that the vehicle motion is measured and the positional deviation is corrected based on the measured vehicle motion.

  As shown in FIG. 6, the illumination control device 310 according to the third embodiment includes an imaging device 12, a vehicle motion measurement sensor group 14 that measures vehicle motion, a headlight 16, and a computer 318. It is configured. The computer 318 can be represented by a configuration including a misalignment correction unit 321.

  The vehicle motion measurement sensor group 14 includes a vehicle speed sensor that detects a vehicle speed, an acceleration sensor that detects acceleration, and a yaw rate sensor that detects a yaw rate. The detection value detected by each sensor is input to the computer 318.

  Based on each of the detection values detected by the vehicle motion measurement sensor group 14, the position deviation correction unit 321 calculates the vehicle motion from when the lit image is captured until when the extinguished image is captured, and the calculated vehicle The position shift accompanying the movement is corrected in at least one of the lighting image and the lighting image.

  The difference image generation unit 22 generates a difference image between the lit image and the unlit image whose position shift has been corrected by the position shift correction unit 321.

  Next, with reference to FIG. 7, an illumination control processing routine in the illumination control apparatus 310 according to the third embodiment will be described. This routine is performed by the CPU executing the lighting control program stored in the ROM when the host vehicle equipped with the lighting control device 310 is running on the road with the headlights 16 turned on at night. .

  In step 100, a lighting image in front of the vehicle when the headlight 16 is lit, which is photographed by the photographing device 12, is acquired.

  Next, in step 102, the headlight 16 is turned off instantaneously. Next, in step 104, a turn-off image in front of the vehicle when the headlight 16 is turned off is acquired, and the headlight 16 is turned on again.

  Next, in step 330, the vehicle motion measurement sensor group 14 detects from the time when the lighting image acquired in step 100 is captured to the time when the extinguishing image acquired in step 104 is captured. Get each of the detection values.

  Next, in step 332, based on each of the detection values detected by the vehicle motion measurement sensor group 14, the vehicle motion from when the lit image is captured until when the extinguished image is captured is calculated. The position shift accompanying the movement is corrected in at least one of the lighting image and the lighting image. Here, it is assumed that the positional deviation is corrected in the lighting image.

  Next, in step 236, a difference image between the lighting image whose position shift is corrected in step 332 and the extinguishing image acquired in step 104 is generated. Hereinafter, similarly to the first embodiment, an appropriate illumination area is set based on the difference image, and the light distribution control of the headlight 16 is performed.

  As described above, according to the illumination control device according to the third embodiment, when the lighting image is captured and when the extinction image is captured based on each of the detection values of the vehicle motion measurement sensor group. In order to correct the positional deviation accompanying the vehicle movement between the two and the difference image, and to prevent the positional deviation due to the vehicle movement from affecting the difference image, the illumination region is more appropriately based on the differential image corrected for the positional deviation. Can be set.

  In the second and third embodiments, the case where the difference image is generated after correcting the positional deviation in the lit image or the unlit image has been described. However, the positional deviation correction unit calculates the positional deviation amount. The difference image generation unit may generate the difference image using the acquired lighting image and extinguishing image and the calculated positional deviation amount.

  Next, a fourth embodiment will be described. In addition, about the same structure and process as 1st-3rd embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  In the lighting control devices of the first to third embodiments, the lighting control process executed when the headlight 16 is turned on at night has been described. However, in the fourth embodiment, the lighting control process described above is performed. Is applied when entering a place with low illuminance such as a tunnel in the daytime.

  As shown in FIG. 8, the illumination control device 410 according to the fourth embodiment includes an imaging device 12, an illuminometer 15 that measures the illuminance around the vehicle in time series, a headlight 16, and a computer 418. It is configured to include. The computer 418 can be expressed by a configuration including an illuminance change amount determination unit 430 that determines whether or not the illuminance change amount measured by the illuminometer 15 is equal to or greater than an illuminance threshold.

  The illuminance change amount determination unit 430 acquires the illuminance measured in time series by the illuminometer 15, calculates the illuminance change amount, and determines whether the calculated change amount is equal to or greater than the illuminance threshold. For example, when entering a tunnel while traveling outdoors in the daytime, the illuminance around the vehicle changes greatly, and the calculated change in illuminance becomes equal to or greater than the illuminance threshold. The illuminance threshold value is set in advance to a value that can determine a change in illuminance to the extent that the headlight 16 should be turned on.

  In addition to controlling the light distribution of the headlight 16 so that the illumination light is projected to the set illumination area, the illumination control unit 428 is turned off based on the determination result of the illuminance change amount determination unit 430. Control is performed to turn on the headlight 16 that has been turned on.

  Next, an illumination lighting control process routine in the illumination control apparatus 410 according to the fourth embodiment will be described with reference to FIG. When the engine is started, this routine starts when the CPU executes an illumination lighting control program stored in the ROM.

  In step 440, it is determined whether or not the headlight 16 is turned off. If the light is off, the process proceeds to step 442. If the light is on, the process proceeds to step 448.

  In step 442, the illuminance measured by the illuminometer 15 is acquired as time-series data. Next, in step 444, it is determined whether the amount of change in illuminance is greater than or equal to the illuminance threshold. If the amount of change in illuminance is greater than or equal to the illuminance threshold, the process proceeds to step 446 and the headlight 16 is turned on. If it is smaller than the illuminance threshold, the process returns to step 442.

  If it is determined in step 440 that the headlight 16 is turned on, and if the headlight 16 is turned on in step 446, in step 448, the first embodiment or the second implementation is performed. The illumination control process in the form is executed. In addition, a vehicle motion measurement sensor group may be provided to execute the illumination control process in the third embodiment.

  When the vehicle leaves the tunnel, the headlight 16 is automatically turned off when the pixel value of the difference image is equal to or less than the difference threshold in the illumination control process. In addition, since the process of the said step 442 and step 444 is a process performed when the headlight 16 is extinguished, even if the illumination intensity around a vehicle changes large when exiting a tunnel, illumination lighting control There is no effect on the processing and lighting control processing.

  As described above, according to the illumination control device according to the fourth embodiment, it is determined whether or not the amount of change in illuminance around the vehicle is equal to or greater than the illuminance threshold, and the headlight is turned on when the illuminance threshold is greater than or equal to Then, since the lighting control process is executed, the present invention can be applied even during daytime running.

  In the first to fourth embodiments, the case has been described in which the difference image is divided into regions and it is determined for each region whether the pixel value included in the region is larger than the difference threshold value. It is also possible to make a determination by comparing each pixel with a difference threshold value, and to make an area in which pixels adjacent to each other whose pixel value is determined to be larger than the difference threshold value are grouped into a group of pixels. Further, it may be divided into regions for each predetermined block (for example, a block of 8 pixels × 8 pixels) regardless of the pixel value.

10, 210, 310, 410 Illumination control device 12 Imaging device 14 Vehicle motion measurement sensor group 15 Illuminometer 16 Headlight 18, 218, 318, 418 Computer 22 Difference image generation unit 24 Self-luminous object recognition unit 26 Illumination area setting unit 28 428 Illumination control units 221, 321 Position shift correction unit 430 Illuminance change amount determination unit

Claims (7)

Photographing means for photographing a target area in front of the vehicle;
Illumination means capable of projecting illumination light in front of the vehicle when turned on and capable of light distribution control for stopping projection of the illumination light when turned off;
Differential image generation for generating a difference image between a lighting image taken by the photographing means when the lighting means is turned on and a light-off image taken by the photographing means when the lighting means is turned off Means,
A setting means for setting an area in front of the vehicle corresponding to an area including a pixel having a pixel value of a difference image generated by the difference image generation means larger than a difference threshold as an illumination area to which illumination light is projected;
Control means for controlling the light distribution of the illumination means so that the illumination light is projected onto the illumination area set by the setting means and the illumination light to areas other than the illumination area is not dimmed or projected. ,
Including a lighting control device.   The said setting means is the said vehicle corresponding to the area | region containing the pixel whose pixel value of the said difference image is a pixel below the said difference threshold value, and the pixel value of the corresponding pixel in the said lighting image or the said light extinction image is more than a high-intensity threshold value The illumination control device according to claim 1, wherein an upper area of a front area is excluded from the illumination area and set as an area other than the illumination area.   3. The difference image generation unit generates a difference image by correcting a positional shift accompanying a vehicle motion between when the lighting image is captured and when the extinguishing image is captured. The lighting control device described.   The difference image generation means captures a plurality of frames of the lit image or the unlit image at different times, and corrects a positional shift caused by the vehicle motion by an optical flow obtained based on the captured images of the plurality of frames. Item 4. The lighting control device according to item 3. Vehicle movement measurement means for measuring vehicle movement by detecting at least one of vehicle speed, acceleration, and yaw rate;
The illumination control device according to claim 3, wherein the difference image generation unit corrects a positional shift associated with the vehicle motion based on the vehicle motion measured by the vehicle motion measurement unit. Including illuminance detection means for detecting illuminance around the vehicle in time series,
The control by the control unit is started when the amount of change in the illuminance detected in time series by the illuminance detection unit becomes equal to or greater than the illuminance threshold in a state where the illumination unit is turned off. The lighting control device according to claim 1. Computer
The target area in front of the vehicle when the illumination means capable of light distribution control that projects illumination light in front of the vehicle when turned on and stops light projection of the illumination light when turned off A difference image generating means for generating a difference image between a lit image taken by a photographing means for photographing and an unlit image photographed by the photographing means when the illumination means is turned off;
A setting means for setting an area in front of the vehicle corresponding to an area including a pixel having a pixel value of a difference image generated by the difference image generation means larger than a difference threshold as an illumination area to which illumination light is projected;
Control means for controlling the light distribution of the illumination means so that the illumination light is projected onto the illumination area set by the setting means and the illumination light to areas other than the illumination area is not dimmed or projected. ,
Lighting control program to make it function.