JP2014223872A - Rear fog lamp controller and rear fog lamp system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel control technique of a rear fog lamp.SOLUTION: A rear fog lamp controller 300 of one embodiment comprises: a light curtain state acquisition part 310 for acquiring a detection result of a light curtain detection device 200 which detects a state of light curtain M formed by diffusion of light radiated from a rear fog lamp unit 100 toward a rear direction of an own vehicle by mist; and a brightness adjustment part 320 for outputting a brightness reduction signal for reducing the brightness of the light radiated from the rear fog lamp unit 100 so that the brightness becomes lower than that of the light radiated in the case where the light curtain state is in a standard state, when the light curtain state is different from the predetermined standard state, which is the state of the light curtain formed under the state that it is estimated that glare is not given to the surrounding vehicles of the own vehicle or pedestrians.

Description

  The present invention relates to a rear fog lamp control device and a rear fog lamp system, and more particularly to a rear fog lamp control device and a rear fog lamp system used in a vehicle such as an automobile.

  2. Description of the Related Art Conventionally, there has been known a rear fog lamp that functions as a marker lamp for irradiating light behind a vehicle and causing a subsequent vehicle or the like to visually recognize the presence of the host vehicle. For example, in Patent Document 1, the amount of light from a rear fog lamp is reduced when there is almost no fog, so that the driver of the following vehicle avoids being dazzled, and the amount of light is increased when fog is dark. Thus, there is disclosed a fog lamp control device intended to enable a driver of a following vehicle to visually recognize a vehicle ahead even in dense fog. This fog lamp device has a rear fog lamp that illuminates the rear of the vehicle, a radio wave radar that detects the inter-vehicle distance from the following vehicle, and a laser for the following vehicle a predetermined number of times when the inter-vehicle distance from the subsequent vehicle is detected by the radio wave radar. Transmits light and receives reflected laser to detect the distance between the vehicle and the following vehicle, and the surrounding light transmittance is detected from the number of times the reflected laser is received from the laser transmitted from the laser radar. And a control circuit that changes the amount of light of the rear fog lamp in accordance with the detected light transmittance.

  Further, Patent Document 2 discloses a fog lamp device intended to reduce discomfort to the following vehicle. In this fog lamp device, a rear fog lamp provided at the rear of the vehicle, a subsequent vehicle detecting means for detecting a succeeding vehicle, and a succeeding vehicle detected by the subsequent vehicle detecting means are traveling within a predetermined distance from the own vehicle. On this condition, there is provided lighting mode change control means for turning off the rear fog lamp in the lighting state or lowering the optical axis of the rear fog lamp.

JP-A-5-278519 JP 2008-213618 A

  As a result of intensive research on the rear fog lamp control device, the present inventors as a rear fog lamp control technology for reducing the possibility of giving glare to vehicles and pedestrians located around the back of the host vehicle, We came up with a new control technology.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a new control technology for a rear fog lamp.

  In order to solve the above problems, an aspect of the present invention is a rear fog lamp control device. The rear fog lamp control device acquires a detection result of a light curtain detection device that detects a state of a light curtain formed by diffusing light irradiated from the rear fog lamp unit to the rear of the host vehicle with fog. When the state acquisition unit and the light curtain state are different from a predetermined reference state that is a state of the light curtain formed under the condition that glare is not given to vehicles or pedestrians around the host vehicle, A brightness adjusting unit that outputs a brightness reduction signal so as to reduce the brightness of the light emitted from the fog lamp unit to be lower than the brightness of the light emitted when the light curtain state is in the reference state. . According to this aspect, a new rear fog lamp control technique can be provided.

  In the above aspect, the light curtain state includes at least one of the shape, brightness, and position of the light curtain, and the brightness adjusting unit determines that the brightness of the light curtain is a predetermined reference when the shape of the light curtain is different from the predetermined reference shape. The luminance reduction signal may be output when at least one of the case where the brightness is smaller and the case where the position of the light curtain is different from the predetermined reference position is satisfied. Further, in the above aspect, the brightness adjustment unit includes a fog density determination unit that determines the fog density based on the brightness of the light curtain, and a signal output unit that outputs a brightness reduction signal. When the curtain brightness is lower than the reference brightness, a low density signal indicating that the fog density is a predetermined low density is output to the signal output unit, and the signal output unit reduces the brightness when the low density signal is acquired. A signal may be output.

  Further, in any one of the above aspects, the brightness adjustment unit includes an obstacle determination unit that determines the presence or absence of an obstacle based on the shape of the light curtain, and a signal output unit that outputs a luminance reduction signal. The unit outputs an obstacle signal indicating that an obstacle is present to the signal output unit when the shape of the light curtain is different from the reference shape, and the signal output unit reduces the brightness when the obstacle signal is acquired. A signal may be output. In any one of the above aspects, the brightness adjustment unit includes a road surface determination unit that determines a road surface shape based on at least one of the shape and position of the light curtain, and a signal output unit that outputs a luminance reduction signal. The determination unit outputs a slope signal indicating that the road surface shape is a slope when the shape of the light curtain is different from the reference shape and / or when the position of the light curtain is different from the reference position. The signal output unit may output the luminance reduction signal when the slope signal is acquired.

  Another aspect of the present invention is a rear fog lamp system. The rear fog lamp system includes a rear fog lamp unit that irradiates light behind the host vehicle, and a light curtain detection device that detects a state of a light curtain formed by diffusing light emitted from the rear fog lamp unit with fog. And a rear fog lamp control device that controls light irradiation of the rear fog lamp unit. The rear fog lamp control device is formed under a situation in which a light curtain state acquisition unit that acquires a detection result of the light curtain detection device and a state in which the light screen state is estimated not to give glare to a vehicle or a pedestrian around the host vehicle. The brightness of the light emitted from the rear fog lamp unit is reduced to be lower than the brightness of the light emitted when the light curtain state is in the reference state when it is different from the predetermined reference state which is the state of the light curtain. A luminance adjusting unit that outputs a luminance reduction signal. This aspect can also provide a new control technology for the rear fog lamp.

  ADVANTAGE OF THE INVENTION According to this invention, the control technology of a new rear fog lamp can be provided.

It is a lineblock diagram of a rear fog lamp system provided with a rear fog lamp control device concerning an embodiment. FIG. 2A is a schematic diagram illustrating image data acquired by the light curtain detection apparatus in a situation where the fog density is equal to or higher than the density reference value. FIG. 2B is a schematic diagram showing image data acquired by the light curtain detection apparatus in a situation where the fog density is lower than the density reference value. FIG. 3A is a schematic diagram illustrating image data acquired by the light curtain detection apparatus in a state where no obstacle exists. FIG. 3B is a schematic diagram illustrating image data acquired by the light curtain detection device in a situation where an obstacle exists. FIG. 4A is a schematic diagram showing image data acquired by the light curtain detection device in a state where the road surface is substantially horizontal. FIGS. 4B and 4C are schematic diagrams illustrating image data acquired by the light curtain detection device in a state where the road surface is inclined. FIG. 5A is a schematic diagram showing a relationship between a laser beam emission direction and a road surface in a vehicle traveling on a slope. FIG. 5B is a schematic diagram showing image data acquired by the light curtain detection device in a situation where the road surface is inclined. It is a flowchart which shows an example of the control performed by the rear fog lamp control apparatus which concerns on embodiment.

  The present invention will be described below based on preferred embodiments with reference to the drawings. The same or equivalent components, members, and processes shown in the drawings are denoted by the same reference numerals, and repeated descriptions are omitted as appropriate. The embodiments do not limit the invention but are exemplifications, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention.

  FIG. 1 is a conceptual diagram of a configuration of a rear fog lamp system including a rear fog lamp control device according to an embodiment. The rear fog lamp control device 300 is realized by elements and circuits such as a CPU and a memory of a computer as a hardware configuration, and is realized by a computer program as a software configuration. In FIG. It is drawn as a functional block to be realized. Therefore, those skilled in the art will understand that these functional blocks can be realized in various forms by a combination of hardware and software.

  The rear fog lamp system 1 according to the present embodiment includes a rear fog lamp unit 100, a light curtain detection device 200, and a rear fog lamp control device 300. Hereinafter, the configuration of each unit will be described in detail.

(Rear fog lamp unit)
The rear fog lamp unit 100 is a lamp unit that irradiates light behind the host vehicle, and is provided at a predetermined position at the rear of the vehicle. The rear fog lamp unit 100 is turned on when fog is generated around the host vehicle, and functions as a marker lamp that makes it easier for the following vehicle to visually recognize the presence of the host vehicle.

  The rear fog lamp unit 100 includes a lamp body (not shown) having an opening on the rear side of the vehicle, and a translucent cover (not shown) attached so as to cover the opening of the lamp body. Placed in. The rear fog lamp unit 100 includes a light source 102, a reflector 104, and a lens 106.

  The light source 102 of the present embodiment is a laser light source that emits red laser light L, and is configured by, for example, a laser diode. The light source 102 may be configured by a laser device other than a laser diode, such as a solid-state laser or a gas laser. The light source 102 is not limited to a laser light source, and may be configured by an LED, a laser light source, a combination of an LED and a phosphor using these as an excitation light source, or the like.

  The reflector 104 has a reflecting surface that reflects the laser light L, and the positional relationship between the light source 102 and the lens 106 is determined so as to reflect the laser light L emitted from the light source 102 toward the lens 106. . The lens 106 is an optical member that emits the laser light L reflected by the reflector 104 to the outside of the rear fog lamp unit 100. The lens 106 emits the laser light L downward from the horizontal direction. For example, the laser beam L is emitted toward a point of 2 to 10 m behind the host vehicle. The lens 106 is constituted by, for example, a cylindrical lens, and the laser light L is diffused by the lens 106 in the vehicle width direction.

  When the laser light L is irradiated from the rear fog lamp unit 100 to the rear of the host vehicle in a state where fog is generated around the host vehicle, the laser beam L is diffused by the fog and a light curtain M is formed. For example, the light curtain M is inclined so as to approach the road surface as the distance from the vehicle increases, and has a planar shape having a predetermined width in the vehicle width direction. The rear fog lamp system 1 according to the present embodiment forms a light curtain M by irradiating the fog with laser light L having high brightness and high directivity, and this light curtain M (particularly the main surface of the light curtain M) is formed. Visible to the driver of the following vehicle. Thereby, the improvement of the visibility by the said driver | operator etc. and reduction of the possibility of giving a glare can be aimed at.

  As described above, in the present embodiment, the light curtain M is formed by diffusing the laser light L in the vehicle width direction by the lens 106 formed of a cylindrical lens. However, the structure for forming the light curtain M is used. Is not particularly limited to this. For example, the posture is determined such that the light source 102 emits the laser light L downward from the horizontal direction, and the installation of the reflector 104 is omitted. The lens 106 is composed of a diffraction grating having a predetermined light diffusion capability. In such a configuration, when the laser beam L is emitted from the light source 102, it is diffused by the lens 106 and irradiated to the outside of the rear fog lamp unit 100 with a predetermined spread. Thereby, the light curtain M can be formed.

  Further, the reflector 104 is composed of a MEMS mirror, a galvano mirror, a polygon mirror, or the like, and a light curtain M having a predetermined shape is formed by continuously displacing the traveling direction of the laser light L by high-speed vibration or high-speed rotation of the reflecting surface. can do.

(Light curtain detection device)
The light curtain detection device 200 detects a state of the light curtain M formed by the laser light L emitted from the rear fog lamp unit 100 being diffused by fog (hereinafter, referred to as “light curtain state” as appropriate). It is. In the present embodiment, the light curtain state includes the shape and brightness of the light curtain M. The light curtain detection device 200 is configured by an imaging device such as a camera, for example, and has a posture determined so that the light curtain M can be imaged and is mounted on a vehicle. The light curtain detection device 200 is disposed below the rear fog lamp unit 100, for example. The image data acquired by the light curtain detection device 200 is sent to the rear fog lamp control device 300. The light curtain detection device 200 may be built in the rear fog lamp unit 100.

(Rear fog lamp control device)
The rear fog lamp control device 300 is a device that controls light irradiation of the rear fog lamp unit 100 according to the state of the light curtain M. That is, the rear fog lamp control device 300 determines whether or not the situation around the host vehicle is highly likely to give glare to vehicles, pedestrians, and the like that are located around the host vehicle by light irradiation of the rear fog lamp unit 100. The determination is made based on the light curtain state, and the brightness of the laser light L is adjusted according to the determination result. The rear fog lamp control device 300 may be incorporated in the rear fog lamp unit 100.

  For example, when a rear fog lamp switch (not shown) provided in the vehicle is turned on by a driver, the rear fog lamp control device 300 performs irradiation control of the laser light L. The rear fog lamp control device 300 includes a light curtain state acquisition unit 310, a brightness adjustment unit 320, and a lighting control module 330.

(Light curtain status acquisition part)
The light curtain state acquisition unit 310 acquires image data as a detection result of the light curtain detection device 200. Then, the light curtain state acquisition unit 310 performs image processing such as BG correction (color correction for blue and green) on the image data, detects the light curtain M from the image data, and acquires data regarding the state of the light curtain M. calculate. In the present embodiment, the light curtain state acquisition unit 310 calculates data relating to the brightness and shape of the light curtain M as data relating to the state of the light curtain M. The calculated light curtain state data is sent to the brightness adjustment unit 320.

(Lighting control module)
The lighting control module 330 is configured by a power supply circuit or the like, and supplies power necessary for lighting the light source 102. Moreover, the lighting control module 330 reduces the electric power supplied to the light source 102 when the luminance reduction signal transmitted from the luminance adjusting unit 320 is received as will be described later. Thereby, the brightness of the laser light L emitted from the light source 102 can be reduced. When the lighting control module 330 receives the luminance reduction signal, the lighting control module 330 may reduce the luminance of the laser light L to 0 (that is, turn off the light), or glare to the driver of the following vehicle while the lighting state of the light source 102 is maintained. You may reduce to such an extent that the possibility of giving may be reduced. The degree to which the luminance is reduced can be appropriately set according to the results of experiments and simulations by the designer based on whether glare is given to the driver of the following vehicle or the like.

(Brightness adjuster)
The luminance adjustment unit 320 adjusts the luminance of the laser light L based on the light curtain state data calculated by the light curtain state acquisition unit 310. Specifically, the brightness adjusting unit 320 has information indicating a predetermined reference state in advance in a memory (not shown) as information relating to the light curtain state. Then, the brightness adjustment unit 320 reduces the brightness of the laser light L when the light curtain state is different from the predetermined reference state than the brightness of the laser light L emitted when the light curtain state is in the reference state. A luminance reduction signal is output so that the The “predetermined reference state” refers to a state of the light curtain M formed under a situation where glare is not given to a vehicle or a pedestrian around the host vehicle.

  In the present embodiment, the reference shape and the reference luminance are included in the predetermined reference state of the light curtain M. Further, in the “predetermined reference state”, the fog density around the own vehicle is equal to or higher than the predetermined density reference value, and obstacles including the following vehicles, pedestrians, buildings, etc. are present in the extension range of the light curtain M. The state of the light curtain M formed in a situation where the traveling road surface is a substantially horizontal road surface. The “concentration reference value” can be appropriately set according to the results of experiments and simulations by the designer based on the viewpoint of whether or not to give glare to the driver or the like of the following vehicle. Then, the luminance adjustment unit 320 outputs a luminance reduction signal when at least one of the case where the shape of the light curtain M is different from the predetermined reference shape and the case where the luminance of the light curtain M is smaller than the predetermined reference luminance is satisfied. .

  More specifically, the brightness adjustment unit 320 includes a fog density determination unit 322, an obstacle determination unit 324, a road surface determination unit 326, and a signal output unit 328.

(Fog density determination part)
FIG. 2A is a schematic diagram illustrating image data acquired by the light curtain detection apparatus in a situation where the fog density is equal to or higher than the density reference value. FIG. 2B is a schematic diagram showing image data acquired by the light curtain detection apparatus in a situation where the fog density is lower than the density reference value.

  The brightness of the light curtain M and the fog density have a correlation. Specifically, the higher the fog density, the easier the laser light L diffuses, so the brightness of the light curtain M increases. Therefore, when the fog density reference value and the reference brightness of the light curtain M corresponding to the density reference value are set, the brightness of the light curtain M is equal to or higher than the reference brightness when the fog density is equal to or higher than the density reference value ( On the other hand, when the fog density is less than the density reference value, the brightness of the light curtain M is less than the reference brightness (see FIG. 2B). Therefore, based on whether or not the brightness of the light curtain M is equal to or higher than the reference brightness, it is possible to determine whether or not the fog density is equal to or higher than the density reference value.

  Therefore, the fog density determination unit 322 determines the fog density around the host vehicle based on the brightness of the light curtain M. The fog density determination unit 322 outputs a low density signal indicating that the fog density is a predetermined low density to the signal output unit 328 when the brightness of the light curtain M is lower than the reference brightness. The signal output unit 328 outputs a luminance reduction signal to the lighting control module 330 when the low density signal is acquired. Here, the “reference brightness” is the brightness of the light curtain M formed when the fog density is at the density reference value. The “predetermined low concentration” is a concentration lower than a concentration reference value.

  When the fog density is lower than the density reference value, the light quantity of the laser light L that travels behind the host vehicle without being diffused by the fog among the laser lights L emitted from the rear fog lamp unit 100 increases. As a result, the driver of the following vehicle is more likely to receive glare due to the laser beam L. On the other hand, when the brightness of the light curtain M is lower than the reference brightness as described above, that is, when the fog density is a predetermined low density, the brightness of the laser light L is reduced, so that the driver of the following vehicle Etc. can be less likely to receive glare by the laser light L.

(Obstacle determination part)
FIG. 3A is a schematic diagram illustrating image data acquired by the light curtain detection apparatus in a state where no obstacle exists. FIG. 3B is a schematic diagram illustrating image data acquired by the light curtain detection device in a situation where an obstacle exists. 3A and 3B, the outline shape of the light curtain M is highlighted with a broken line.

  When an obstacle N such as a following vehicle, a pedestrian, or a building on the road including a power pole or a signboard is present in the region where the light curtain M behind the host vehicle is formed, the obstacle N causes the laser light L to travel. Be disturbed. Therefore, with respect to the shape of the light curtain M formed in a state where no obstacle N exists, that is, the shape of the light curtain M when the light curtain M is in the reference state (hereinafter referred to as “reference shape” as appropriate) The shape of the light curtain M formed in the situation where the obstacle N exists is deformed (see FIG. 3A) (see FIG. 3B). The deformation of the light curtain M at this time includes, for example, a deformation in which a concave portion is formed in a part of the outline of the light curtain M or the light curtain M is divided into a plurality of parts. Therefore, it is possible to determine the presence or absence of an obstacle based on whether or not the shape of the light curtain M is the same as the reference shape.

  Therefore, the obstacle determination unit 324 determines the presence or absence of an obstacle based on the shape of the light curtain M. The obstacle determination unit 324 outputs an obstacle signal indicating that there is an obstacle behind the host vehicle to the signal output unit 328 when the shape of the light curtain M is different from the reference shape. The signal output unit 328 outputs a luminance reduction signal to the lighting control module 330 when the obstacle signal is acquired.

  When the obstacle N is present in the area where the light curtain M is formed, the laser light L emitted from the rear fog lamp unit 100 is reflected by the obstacle N, and thereby a pedestrian existing ahead of the reflected laser light L. There is a risk of glare. Alternatively, when the obstacle N is a following vehicle or a pedestrian, the laser light L may be directly applied to the following vehicle or pedestrian, which may cause glare to the driver or pedestrian of the following vehicle. On the other hand, as described above, when the shape of the light curtain M is different from the reference shape, that is, when there is an obstacle N, the brightness of the laser light L is reduced, so that The possibility of giving glare to a vehicle or a pedestrian that is positioned can be reduced.

(Road surface judgment part)
FIG. 4A is a schematic diagram showing image data acquired by the light curtain detection device in a state where the road surface is substantially horizontal. FIGS. 4B and 4C are schematic diagrams illustrating image data acquired by the light curtain detection device in a state where the road surface is inclined. FIG. 5A is a schematic diagram showing a relationship between a laser beam emission direction and a road surface in a vehicle traveling on a slope. FIG. 5B is a schematic diagram showing image data acquired by the light curtain detection device in a situation where the road surface is inclined. In FIG. 4B and FIG. 4C, the reference shape of the light curtain M is indicated by a broken line. In FIG. 5A, the imaging direction of the light curtain detection device is indicated by a broken line. FIG. 5B corresponds to the image data in the situation shown in FIG. 5A, and the reference position of the light curtain M is indicated by a broken line.

  When the road surface R on which the host vehicle travels changes, for example, from a substantially horizontal state to a slope, the position where the laser light L reaches the road surface R, that is, the position of the boundary line P between the light curtain M and the road surface R is It moves in the direction approaching or moving away from the vehicle. Therefore, the light curtain M is deformed so as to be shorter or longer vertically with respect to a reference shape (a shape when the light curtain M is in the reference state) formed in a state where the road surface is substantially horizontal. For example, when the host vehicle approaches a downhill from a state where the host vehicle is traveling on a substantially horizontal road surface R (see FIG. 4A), the position of the boundary line P is displaced in a direction away from the host vehicle, thereby The curtain M changes to a shape extending downward from the reference shape. In the case of a steep downhill, the road surface R is out of the imaging range of the light curtain detection device 200, and a light curtain M having a shape extending further downward than the state shown in FIG. 4B is formed. (See FIG. 4C). Therefore, it is possible to determine the road surface shape based on whether or not the shape of the light curtain M is the same as the reference shape.

  Therefore, the road surface determination unit 326 determines the road surface shape based on the shape of the light curtain M. When the shape of the light curtain M is different from the reference shape, the road surface determination unit 326 outputs a slope signal indicating that the road surface shape is a slope to the signal output unit 328. The signal output unit 328 outputs a luminance reduction signal to the lighting control module 330 when the slope signal is acquired.

  Even when the traveling direction of the laser beam L is set to be lower than the horizontal direction in a state where the vehicle is positioned on a substantially horizontal road surface, when the road surface R on which the host vehicle is located is an inclined surface, On the road surface R, the traveling direction of the laser light L may be more than horizontal. In this case, the driver or pedestrian of the following vehicle may directly irradiate the laser beam L, and glare may be given to the driver or pedestrian of the following vehicle. On the other hand, as described above, when the shape of the light curtain M is different from the reference shape, that is, when the road surface shape is an inclined surface, the brightness of the laser light L is reduced, so that it is located behind the host vehicle. The possibility of giving glare to vehicles, pedestrians and the like can be reduced.

  The road surface determination unit 326 may determine the road surface shape based on the position of the light curtain M. That is, as shown in FIG. 5A, when the road surface R on which the host vehicle is located is an inclined surface, the position of the light curtain M may be displaced up and down with respect to the reference position as shown in FIG. is there. Therefore, the road surface determination unit 326 determines the road surface shape based on the position of the light curtain M. The road surface determination unit 326 outputs a slope signal indicating that the road surface shape is a slope to the signal output unit 328 when the position of the light curtain M is different from the reference position. The signal output unit 328 outputs a luminance reduction signal to the lighting control module 330 when the slope signal is acquired.

  For example, the road surface determination unit 326 compares the position of the current lower end portion M1 of the light curtain M with the lower end portion M1 of the light curtain M at the reference position on the image data of the light curtain detection device 200. It can be determined that the shape is a slope. Alternatively, the road surface determination unit 326 detects the position of the lower end M1 of the light curtain M with respect to the position of the upper end R1 of the road surface R, and positions of the upper end R1 and the lower end M1 when the light curtain M is at the reference position. By comparing with the relationship, it can be determined that the road surface shape is a slope. The road surface determination unit 326 may determine the road surface shape using the position of a portion other than the lower end portion of the light curtain M (such as the upper end portion of the light curtain M). The road surface determination unit 326 may determine the road surface shape based only on the shape of the light curtain M, may determine the road surface shape based only on the position of the light curtain M, The road surface shape may be determined by combining the shape and position.

  When the road surface determination unit 326 determines the road surface shape based on the position of the light curtain M, the light curtain state detected by the light curtain detection device 200 includes information regarding the position of the light curtain M. Further, the light curtain state acquisition unit 310 calculates data relating to the position of the light curtain M as data relating to the state of the light curtain M. The “reference position” is the position of the light curtain M when the light curtain M is in the reference state.

  The rear fog lamp control device 300 executes the irradiation control of the laser light L as follows, for example. FIG. 6 is a flowchart illustrating an example of control executed by the rear fog lamp control device according to the embodiment. This flow is repeatedly executed at a predetermined timing by the rear fog lamp control device 300 when the rear fog lamp switch is turned on.

  First, the fog density determination unit 322 determines whether or not the fog has a predetermined low density based on the brightness of the light curtain M (S101). When the mist has a predetermined low concentration (Y in S101), the mist concentration determination unit 322 outputs a low concentration signal to the signal output unit 328. When the signal output unit 328 receives the low density signal, the signal output unit 328 outputs a luminance reduction signal to the lighting control module 330. When receiving the luminance reduction signal, the lighting control module 330 adjusts the power supplied to the light source 102 to reduce the luminance of the laser light L (S104).

  When the fog is not at a predetermined low concentration (N in S101), the obstacle determination unit 324 determines the presence or absence of an obstacle based on the shape of the light curtain M (S102). When there is an obstacle (Y in S102), the obstacle determination unit 324 outputs an obstacle signal to the signal output unit 328. Then, a luminance reduction signal is output from the signal output unit 328 to the lighting control module 330, and the lighting control module 330 reduces the luminance of the laser light L (S104).

  When there is no obstacle (N in S102), the road surface determination unit 326 determines whether the road surface shape is a slope based on the shape of the light curtain M (S103). When the road surface shape is a slope (Y in S103), the road surface determination unit 326 outputs a slope signal to the signal output unit 328. Then, a luminance reduction signal is output from the signal output unit 328 to the lighting control module 330, and the lighting control module 330 reduces the luminance of the laser light L (S104). When the road surface shape is not a slope (N in S103), the brightness of the laser light L is maintained, and this routine is finished.

  As described above, in the rear fog lamp control device 300 according to the present embodiment, the light curtain state acquisition unit 310 acquires the state of the light curtain M. Then, when the light curtain state is different from the predetermined reference state, the luminance adjustment unit 320 reduces the luminance of the laser light L from the luminance in the reference state. Thereby, a possibility that glare may be given to vehicles, pedestrians, etc. which are located around the back of the own vehicle can be reduced. Therefore, according to the present embodiment, it is possible to provide a new rear fog lamp control technique in which the brightness of the laser beam L is adjusted based on the state of the light curtain M formed by the laser beam L.

  The present invention is not limited to the above-described embodiments, and various modifications such as design changes can be added based on the knowledge of those skilled in the art. Embodiments to which such modifications are added Are also included within the scope of the present invention. A new embodiment obtained by modifying the above-described embodiment has the effects of the combined embodiment and modification.

  In the above-described embodiment, the fog concentration determination unit 322, the obstacle determination unit 324, and the road surface determination unit 326 determine the fog concentration, the presence / absence of an obstacle, and the road surface shape, respectively. It is not limited to this. For example, the brightness adjustment unit 320 may include only one or two of the fog density determination unit 322, the obstacle determination unit 324, and the road surface determination unit 326. In addition, instead of the fog density determination unit 322, the obstacle determination unit 324, and the road surface determination unit 326, the luminance adjustment unit 320 has a shape of the light curtain M different from the reference shape when the luminance of the light curtain M is different from the reference luminance. A light curtain determination unit that instructs the signal output unit 328 to output a luminance reduction signal when at least one of the case and the case where the position of the light curtain M is different from the reference position is satisfied.

  When the brightness of the light curtain M is measured as the light curtain state, the light curtain detection device 200 may be a photodetector configured with, for example, a photodiode having sensitivity only to the wavelength region of the laser light L. .

  The obstacle determination unit 324 and the road surface determination unit 326 use a common reference shape, but are not particularly limited thereto. For example, the road surface determination performed by the road surface determination unit 326 can determine the road surface shape if the displacement of the lower end portion of the light curtain M can be detected. Therefore, the reference shape used by the road surface determination unit 326 is the lower end of the light curtain M. Only a partial region of the light curtain M including at least a part of the portion may be used.

  DESCRIPTION OF SYMBOLS 1 Rear fog lamp system, 100 Rear fog lamp unit, 102 Light source, 200 Light curtain detection apparatus, 300 Rear fog lamp control apparatus, 310 Light curtain state acquisition part, 320 Brightness adjustment part, 322 Fog density determination part, 324 Obstacle determination part, 326 Road surface determination unit, 328 signal output unit, M light curtain, N obstacle, R road surface.

Claims (6)

A light curtain state acquisition unit that acquires a detection result of a light curtain detection device that detects a state of the light curtain formed by diffusing the light emitted from the rear fog lamp unit to the rear of the vehicle with fog;
Irradiated from the rear fog lamp unit when the light curtain state is different from a predetermined reference state which is a state of the light curtain formed under the condition that glare is not given to vehicles or pedestrians around the host vehicle. A luminance adjustment unit that outputs a luminance reduction signal so as to reduce the luminance of the emitted light to be lower than the luminance of the light irradiated when the light curtain state is in the reference state;
A rear fog lamp control device comprising: The light curtain state includes at least one of the shape, brightness, and position of the light curtain,
The brightness adjusting unit may be configured such that when the shape of the light curtain is different from a predetermined reference shape, when the luminance of the light curtain is smaller than a predetermined reference luminance, and when the position of the light curtain is different from a predetermined reference position. The rear fog lamp control device according to claim 1, wherein the brightness reduction signal is output when at least one of them is satisfied. The brightness adjustment unit includes a fog density determination unit that determines a fog density based on the brightness of a light curtain, and a signal output unit that outputs the brightness reduction signal,
The fog density determination unit outputs a low density signal indicating that the fog density is a predetermined low density to the signal output unit when the brightness of the light curtain is lower than the reference brightness.
The rear fog lamp control device according to claim 2, wherein the signal output unit outputs the luminance reduction signal when the low density signal is acquired. The luminance adjustment unit includes an obstacle determination unit that determines the presence or absence of an obstacle based on the shape of a light curtain, and a signal output unit that outputs the luminance reduction signal,
The obstacle determination unit outputs an obstacle signal indicating that an obstacle is present to the signal output unit when the shape of the light curtain is different from the reference shape,
The rear fog lamp control device according to claim 2 or 3, wherein the signal output unit outputs the luminance reduction signal when the obstacle signal is acquired. The luminance adjustment unit includes a road surface determination unit that determines a road surface shape based on at least one of the shape and position of a light curtain, and a signal output unit that outputs the luminance reduction signal,
The road surface determination unit indicates that the road surface shape is a slope when at least one of the case where the shape of the light curtain is different from the reference shape and the case where the position of the light curtain is different from the reference position is satisfied. Output the slope signal to the signal output unit,
The rear fog lamp control device according to any one of claims 2 to 4, wherein the signal output unit outputs the luminance reduction signal when the slope signal is acquired. A rear fog lamp unit that irradiates light behind the host vehicle;
A light curtain detection device for detecting a state of a light curtain formed by diffusing the light emitted from the rear fog lamp unit with fog; and
A rear fog lamp control device for controlling the light irradiation of the rear fog lamp unit,
The rear fog lamp control device
A light curtain state acquisition unit for acquiring a detection result of the light curtain detection device;
Irradiated from the rear fog lamp unit when the light curtain state is different from a predetermined reference state which is a state of the light curtain formed under the condition that glare is not given to vehicles or pedestrians around the host vehicle. A luminance adjustment unit that outputs a luminance reduction signal so as to reduce the luminance of the emitted light to be lower than the luminance of the light irradiated when the light curtain state is in the reference state;
A rear fog lamp system comprising:

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