JP2024096553A - Road surface illumination device and road surface illumination method - Google Patents

Abstract

[Problem] To provide a road surface illumination device and road surface illumination method that can reduce or prevent dazzle and annoyance to a driver of a vehicle traveling on a road surface when the driving environment of the vehicle traveling on the road surface becomes wet. [Solution] When the driving environment of a vehicle C traveling on a road surface T becomes wet, of the illumination light B that is irradiated toward an illumination area E divided into a plurality of segment areas S of the road surface T, the illumination light B that is irradiated toward some of the segment areas S corresponding to the vehicle C traveling on the road surface T is partially blocked or dimmed. [Selected Figure] Figure 1

Description

The present invention relates to a road surface illumination device and a road surface illumination method.

For example, when the road surface or vehicle is wet, such as during rainy weather, drivers of vehicles traveling on the road may feel dazzled or annoyed by the light emitted from road lights and street lamps onto the road surface.

Specifically, drivers may feel dazzled by the light reflected back towards the vehicle from the wet road surface ahead of the vehicle, or may feel annoyed by the light shining on the vehicle's wet windows.

Therefore, methods have been proposed to reduce or prevent dazzle and annoyance to drivers of vehicles traveling on wet roads (see, for example, Patent Document 1 below).

Specifically, the following Patent Document 1 proposes a road light luminaire that includes a normal beam unit that illuminates the road surface with its illumination center at a first road surface position, a pro beam unit that illuminates the road surface with its illumination center at a second road surface position that is closer to the vehicle's traveling direction than the first road surface position, a camera that photographs the road surface to obtain an image, and a control circuit that turns on the normal beam unit as the main illumination if it is determined based on the image that the road surface is not wet, and turns on the pro beam unit as the main illumination if it is determined based on the image that the road surface is wet.

JP 2019-114495 A

However, the invention described in the above-mentioned Patent Document 1 is premised on detecting the wetness of the road surface and switching from normal light distribution to pro-beam light distribution in order to suppress reflections from the road surface. For this reason, light distribution is set so that the road surface illuminance within a certain section is constant, and it is not possible to adjust the light distribution partially.

In addition, with pro-beam light distribution, the area of the road surface that can be illuminated is narrow. Therefore, in order to illuminate the required area as road lights, they need to be installed at closer intervals than road lights with normal light distribution.

On the other hand, if road lights with pro beam light distribution are installed at the same intervals as road lights with normal light distribution, when the road surface is wet (especially in bad weather), there will be areas on the road surface that are not illuminated by the pro beam light distribution, and these areas will be dark. In this case, there is a high possibility that drivers will be late in discovering dangerous situations, such as pedestrians, pedestrians crossing the road, or obstacles on the side of the road.

Furthermore, the invention described in Patent Document 1 is only functionally compatible with one lane when installed in an oncoming lane, so installation locations are limited, such as one-way streets and roads with median strips.

The present invention has been proposed in consideration of the above-mentioned conventional circumstances, and aims to provide a road surface illumination device and a road surface illumination method that can reduce or prevent dazzle and annoyance to the driver of a vehicle traveling on a road surface when the driving environment of the vehicle traveling on the road surface becomes wet.

In order to achieve the above object, the present invention provides the following means.
[1] A light source unit having a plurality of light sources that irradiate illumination light toward a road surface;
A lighting control unit that controls lighting of the plurality of light sources;
a vehicle detection unit that acquires position information of a vehicle traveling on the road surface;
a wetness detection unit that detects a wet state in a driving environment of the vehicle;
When the wetness detection unit detects the wet state,
The lighting control unit, based on the vehicle position information acquired by the vehicle detection unit,
Among the illumination light irradiated from the light source unit toward an illumination area divided into a plurality of segment areas of the road surface,
The illumination light irradiated toward the part of the segment area corresponding to the vehicle is partially blocked or dimmed.
A road surface illumination device characterized by controlling switching of the illumination states of the plurality of light sources.
[2] The lighting control unit, for the vehicle passing inside the illumination area,
The illumination light irradiated toward at least a portion of the segment area corresponding to the front window glass is partially blocked or dimmed.
The road surface illumination device according to claim 1, characterized in that it controls switching of the illumination states of the plurality of light sources.
[3] In order to partially block or dim the illumination light irradiated toward a part of the segment areas corresponding to the side window glass of the vehicle,
The road surface illumination device according to claim 2, characterized in that it controls switching of the illumination states of the plurality of light sources.
[4] The lighting control unit, for the vehicle passing inside the illumination area,
The illumination light is reflected by the road surface and then irradiated toward at least a portion of the segment area corresponding to the front window glass, so that the illumination light is partially blocked or dimmed.
The road surface illumination device according to claim 1, characterized in that it controls switching of the illumination states of the plurality of light sources.
[5] The lighting control unit, for the vehicle passing outside the illumination area,
The illumination light is reflected by the road surface and then irradiated toward at least a portion of the segment area corresponding to the front window glass, so that the illumination light is partially blocked or dimmed.
The road surface illumination device according to claim 1, characterized in that it controls switching of the illumination states of the plurality of light sources.
[6] A communication unit for communicating with the outside,
The road surface illumination device described in [1], wherein the vehicle detection unit acquires position information of vehicles traveling on the road surface via the communication unit.
[7] The road surface illumination device according to any one of [1] to [6], characterized in that illumination light is irradiated onto the road surface from road lights or street lights installed along the road surface.
[8] The road surface illumination device according to [7], characterized in that the lighting control unit performs lighting control of the plurality of light sources in a coordinated manner among the plurality of road lamps or street lamps lined up along the road surface.
[9] A road surface illumination method, characterized in that, when the driving environment of a vehicle traveling on a road surface becomes wet, illumination light that is irradiated toward an illumination area divided into a plurality of segment areas of the road surface and that is irradiated toward some of the segment areas corresponding to the vehicle traveling on the road surface is partially blocked or dimmed.

As described above, the present invention provides a road surface illumination device and a road surface illumination method that can reduce or prevent dazzle and annoyance to the driver of a vehicle traveling on a road surface when the driving environment of the vehicle traveling on the road surface becomes wet.

FIG. 1 is a schematic diagram showing a road light to which the present invention is applied. FIG. 2 is a functional block diagram showing a configuration of a road surface illumination device. FIG. 11 is a flowchart for explaining a road surface illumination method. FIG. 11 is a schematic diagram for explaining a road surface illumination method, showing a state in which illumination light is illuminated from a road light toward an illumination area on the road surface that is divided into a plurality of segment areas. 1A to 1D are schematic diagrams for explaining a road surface illumination method, showing states in which the lighting states of a plurality of light sources are switched sequentially in accordance with the movement of a vehicle. 1A and 1B are schematic diagrams for explaining a method of illuminating a road surface, in which (A) shows the illumination range of the illumination light from road lights lined up along the road surface, and (B) shows the state in which the lighting state of multiple light sources is switched according to the illumination light reflected from the road surface toward the vehicle. FIG. 11 is a functional block diagram showing another configuration example of the road surface illumination device.

The following describes an embodiment of the present invention in detail with reference to the drawings.

In the drawings used in the following description, each component may be shown diagrammatically to make it easier to see, and the dimensional ratios of each component may not be the same as in reality. Furthermore, the dimensions and other information given in the following description are merely examples, and the present invention is not necessarily limited to these, and may be modified as appropriate without departing from the spirit of the invention.

A road surface illumination device and a road surface illumination method according to one embodiment of the present invention will be described with reference to Figures 1 to 7.

FIG. 1 is a schematic diagram showing a road light 100 to which the present invention is applied. FIG. 2 is a functional block diagram showing the configuration of the road surface illumination device 1. FIG. 3 is a flow chart diagram for explaining the road surface illumination method. FIG. 4 is a schematic diagram for explaining the road surface illumination method, showing a state in which illumination light B is irradiated from the road light 100 toward an illumination area E divided into a plurality of segment areas e1 and e2 of the road surface T. FIG. 5 is a schematic diagram for explaining the road surface illumination method, showing a state in which the lighting state of the plurality of light sources 2 is sequentially switched according to the movement of the vehicle C. FIG. 6 is a schematic diagram for explaining the road surface illumination method, showing a diagram showing an illumination range of illumination light B by the road light 100 arranged along the road surface T, and a diagram showing a state in which the lighting state of the plurality of light sources 2 is switched according to the illumination light B reflected from the road surface T toward the vehicle C. FIG. 7 is a functional block diagram showing another configuration example of the road surface illumination device 1.

In this embodiment, as shown in FIG. 1, an example will be described in which the road surface illumination device and road surface illumination method of the present invention are applied to a plurality of road lights 100 installed along the road surface T of a road.

The road light 100 of this embodiment ensures visibility of the road surface T for the driver of a vehicle C traveling on the road surface T by emitting illumination light B toward the road surface T at night or during dark weather.

The road lamp 100 of this embodiment includes, for example, a road surface illumination device 1 as shown in FIG. 2, and according to a flow chart of a road surface illumination method as shown in FIG. 3, when the driving environment of a vehicle C traveling on a road surface T as shown in FIG. 1 becomes wet, among the illumination light B irradiated toward an illumination area E divided into a plurality of segment areas of the road surface T, the illumination light B irradiated toward a part of the segment area (enclosed area S in FIG. 1) corresponding to the vehicle C traveling on the road surface T is partially shaded or dimmed (shaded in this embodiment).

Specifically, as shown in FIG. 2, the road surface illumination device 1 of this embodiment includes a light source unit 3 having multiple light sources 2 that irradiate illumination light B toward the road surface T, a lighting control unit 4 that controls the lighting of the multiple light sources 2, a vehicle detection unit 5 that acquires position information of a vehicle C traveling on the road surface T, a wet detection unit 6 that detects a wet state in the driving environment of the vehicle traveling on the road surface T, a communication unit 7 that communicates with the outside, and a power supply unit 8 that supplies power to each unit.

The light source unit 3 is composed of a matrix light source in which a plurality of light sources 2, such as light emitting diodes (LEDs), are arranged in a matrix. The illumination light B emitted from the light source 2 is generally white light, but may be orange light, for example.

As shown in FIG. 4, the light source unit 3 is disposed within the body of the street light 100, and irradiates the illumination light B emitted radially from the multiple light sources 2 toward an illumination area E on the road surface T from above to below. The illumination area E corresponds to the illumination range of the illumination light B from a normal street light 100.

The illumination area E is divided into a plurality of first segment areas e1 and second segment areas e2. Of these, the first segment area e1 is arranged by dividing the inside of the lane L of the road surface T in the traveling direction of the vehicle C.

On the other hand, the second segment area e2 is arranged on both sides (outside) of the road surface T in the traveling direction of the vehicle C, sandwiching the multiple first segment areas e1. In addition, the second segment area e2 is in a specular reflection area R1 where the illumination light B from the light source unit 3 toward the road surface T is specularly reflected by the wet road surface T.

Inside the regular reflection region R1 is an intermediate reflection region R2 in which the illumination light B is regular reflected depending on the unevenness of the road surface T, and inside the intermediate reflection region R2 is a matrix division region R3 in which at least a plurality of first segment regions e1 are arranged in a matrix.

In the light source unit 3, at least one or two or more light sources 2 are assigned to each segment area e1, e2 so that illumination light B is irradiated (distributed) toward each segment area e1, e2.

The lighting control unit 4 is composed of a computer such as a CPU, and controls the switching of the lighting state (on (ON)/off (OFF)) of each of the multiple light sources 2 using power supplied from the power supply unit 8.

In addition to switching each light source 2 on and off, the lighting control unit 4 may also control the light intensity and color tone of the illumination light B emitted from each light source 2.

The vehicle detection unit 5 detects a vehicle C traveling on a road surface T using, for example, a camera, millimeter wave radar, ToF, LiDAR, V2I (vehicle-to-infrastructure communication), etc., and obtains position information of the vehicle C. The position information of the vehicle C obtained by this vehicle detection unit 5 is supplied to the lighting control unit 4.

The vehicle detection unit 5 may also acquire position information of a vehicle C from outside the street light 100 via the communication unit 7 and supply it to the lighting control unit 4.

The wet detection unit 6 detects a wet state in the driving environment of the vehicle C traveling on the road surface T, for example, using a rain sensor. When the wet detection unit 6 detects a wet state, the detected signal is supplied to the lighting control unit 4.

The wet state may be a state in which the road surface T or the vehicle C is wet due to rainfall or snowfall during rainy weather. In this embodiment, when the road surface T is wet, it is determined that the vehicle C is also wet, and the wet state of the road surface T is detected. In addition, the wet state includes not only rainy weather, but also the beginning and end of the above-mentioned rainfall or snowfall (after rain).

The wet detection unit 6 may also supply a signal indicating a wet state detected from outside the street light 100 to the lighting control unit 4 via the communication unit 7. For example, the signal supplied from the outside may include information about rainy weather at the location where the street light 100 is installed (rainy weather information). In other words, it may be possible to determine that the road surface T or the vehicle C is in a wet state from this rainy weather information supplied from the outside, and detect a wet state in the driving environment of the vehicle C traveling on the road surface T.

The communication unit 7 is capable of performing wired or wireless (wired in this embodiment) communication between the street light 100 and the outside. The communication unit 7 is also capable of performing communication between multiple street lights 100 lined up along the road surface T.

Therefore, in the road surface illumination device 1 of this embodiment, it is possible to coordinate the lighting control of multiple light sources 2 among multiple road lights 100 lined up along the road surface T.

In the street light 100 of this embodiment having the above configuration, at night or during dark weather, all of the multiple light sources 2 in the light source unit 3 are turned on, thereby irradiating the illumination light B toward all of the segment areas e1 and e2 of the illumination area E.

The road surface illumination device 1 of this embodiment controls switching of the illumination state of multiple light sources 2 according to the flowchart of the road surface illumination method shown in Figure 3.

Specifically, first, in step S101 shown in FIG. 3, the wetness detection unit 6 detects the wet state of the road surface T, and if the lighting control unit 4 determines based on this detection signal that the road surface T is not wet (No), it performs control to keep all of the multiple light sources 2 lit (ON).

On the other hand, if the lighting control unit 4 determines that the road surface T is wet due to rainfall or snowfall during rainy weather (Yes), the process proceeds to step S102 shown in FIG. 3.

Next, in step S102 shown in FIG. 3, if the vehicle detection unit 5 does not acquire the position information of the vehicle C (No), the lighting control unit 4 performs control to keep all of the multiple light sources 2 turned on (ON).

On the other hand, if the vehicle detection unit 5 acquires the position information of the vehicle C (Yes), as shown in Figures 5 (A) to (D), the lighting control unit 4 controls the light source 2 in the first segment area e1 corresponding to the vehicle C to be turned off (OFF) based on the position information of the vehicle C acquired by the vehicle detection unit 5.

The lighting control unit 4 also controls the light sources 2 in the first segment area e1 aligned in the travel direction of the vehicle C to be switched off in sequence in accordance with the movement of the traveling vehicle C.

This makes it possible to partially block the illumination light B irradiated toward a vehicle C passing inside the illumination area E.

In the road surface illumination device 1 of this embodiment, the lighting control unit 4 controls switching of the lighting state of the multiple light sources 2 so that the illumination light B irradiated toward at least the first segment area e1 corresponding to the front window glass is partially blocked or dimmed (blocked in this embodiment) for a vehicle C passing inside the illumination area E.

In addition, in this embodiment, the illumination light B irradiated toward the first segment area e1 corresponding to the window glass on the side of the vehicle C in addition to the front of the vehicle C may be partially blocked or dimmed (blocked in this embodiment).

Specifically, the light source 2 corresponding to the first segment area e1 that is more than 2/3 of the way from the front end of the vehicle C and the light source 2 corresponding to the first first segment area e1 forward from the front end of the vehicle C are turned off (OFF).

This makes it possible to prevent the driver from feeling annoyed by illumination light B being irradiated onto the wet window glass of vehicle C.

In this embodiment, when a vehicle C passing inside the illumination area E passes through 3/4 or more of the illumination area E, the illumination light B irradiated from the road light 100 toward the vehicle C is mainly irradiated from the rear of the vehicle C. In this case, the effect of partially blocking the illumination light B irradiated toward the vehicle C passing inside the illumination area E described above is weakened, so the lighting control by the lighting control unit 4 described above may be stopped.

In addition, in the road surface illumination device 1 of this embodiment, the lighting control unit 4 controls switching of the lighting state of the multiple light sources 2 so that the illumination light B that is reflected by the road surface T and then irradiated toward at least the first segment area e1 corresponding to the front window glass is partially blocked or dimmed (blocked in this embodiment) for a vehicle C passing inside the illumination area E.

Specifically, the light source 2 that corresponds to the second first segment area e1 forward from the front end of the vehicle C is turned off.

This makes it possible to prevent the driver from feeling dazzled by the illumination light B reflected toward the vehicle C from the wet road surface T ahead.

In addition, in the road surface illumination device 1 of this embodiment, as shown in Figures 6 (A) and (B), the lighting control unit 4 controls the switching of the lighting state of the multiple light sources 2 so that the illumination light B that is reflected by the road surface T and then irradiated toward at least the second segment area e2 corresponding to the front window glass is partially blocked or dimmed (blocked in this embodiment) for a vehicle C passing outside the illumination area E.

Specifically, the illumination areas E of multiple street lights 100 arranged at regular intervals D along the road surface T partially overlap each other.

In this embodiment, while communication is performed between these multiple street lights 100, for a vehicle C that passes outside the illumination area E of the two street lights 100 located in front of the vehicle C, the light source 2 corresponding to the second segment area e2 of this illumination area E is turned off.

This makes it possible to prevent the driver from feeling dazzled by the illumination light B reflected toward the vehicle C from the wet road surface T ahead.

As described above, the road surface illumination device 1 and road surface illumination method of this embodiment can eliminate or reduce risk factors when driving in rainy weather, etc., by partially blocking (or dimming) the light distribution in an area that may cause the driver of the vehicle C described above to feel dazzled or bothered.

This makes it possible to reduce or prevent glare and annoyance caused by the illumination light B irradiated from the road light 100 toward the road surface T for the driver of the vehicle C traveling on the road when the road surface T is wet, such as during rainy weather.

In addition to eliminating or reducing risk factors when driving in the rain, it is also possible to ensure safer traffic by preventing the driver from being unable to see surrounding vehicles and pedestrians.

The present invention is not necessarily limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

For example, the road surface illumination device 1 is not necessarily limited to the configuration shown in FIG. 2 above, and may be configured as shown in FIGS. 7(A) to (C), for example.

Specifically, the configuration shown in FIG. 7(A) is a configuration in which the wetness detection unit 6 is provided in the street light 100. In addition, in the case of this configuration, a signal that detects the wet state of the road surface T may be obtained from outside the street light 100 via the communication unit 7.

On the other hand, in the configuration shown in FIG. 7(B), an illuminance detection unit 9 is provided in the street light 100 instead of the wetness detection unit 6. The illuminance detection unit 9 detects when it is dark around the street light 100 and supplies this detected signal to the lighting control unit 4. This makes it possible to respond individually to sudden bad weather, etc.

On the other hand, in the configuration shown in FIG. 7(C), the communication unit 7 communicates with the outside world wirelessly. In this configuration, wireless communication is possible between multiple street lights 100 lined up along the road surface T.

In addition, in the above embodiment, an example is given of the case where the road surface illumination device and road surface illumination method of the present invention are applied to a plurality of road lights 100 installed along the road surface T of the above-mentioned road, but the road surface illumination device and road surface illumination method of the present invention can also be applied to street lights, similar to the above-mentioned road lights 100.

1...Road surface illumination device 2...Light source 3...Light source section 4...Lighting control section 5...Vehicle detection section 6...Wet detection section 7...Communication section 8...Power supply section 9...Illuminance detection section E...Illumination area e1...First segment area e2...Second segment area 100...Road light B...Illumination light T...Road surface C...Vehicle L...Lane S...Segment area

Claims (9)

a light source unit having a plurality of light sources that irradiate illumination light toward a road surface;
A lighting control unit that controls lighting of the plurality of light sources;
a vehicle detection unit that acquires position information of a vehicle traveling on the road surface;
a wetness detection unit that detects a wet state in a driving environment of the vehicle;
When the wetness detection unit detects the wet state,
The lighting control unit, based on the vehicle position information acquired by the vehicle detection unit,
Among the illumination light irradiated from the light source unit toward an illumination area divided into a plurality of segment areas of the road surface,
The illumination light irradiated toward the part of the segment area corresponding to the vehicle is partially blocked or dimmed.
A road surface illumination device characterized by controlling switching of the illumination states of the plurality of light sources. The lighting control unit, for the vehicle passing inside the illumination area,
The illumination light irradiated toward at least a portion of the segment area corresponding to the front window glass is partially blocked or dimmed.
The road surface illumination device according to claim 1, further comprising control for switching the illumination states of the plurality of light sources. The illumination light irradiated toward a part of the segment area corresponding to the side window glass of the vehicle is partially blocked or dimmed.
The road surface illumination device according to claim 2 , further comprising control for switching the illumination states of the plurality of light sources. The lighting control unit, for the vehicle passing inside the illumination area,
The illumination light is reflected by the road surface and then irradiated toward at least a portion of the segment area corresponding to the front window glass, so that the illumination light is partially blocked or dimmed.
The road surface illumination device according to claim 1, further comprising control for switching the illumination states of the plurality of light sources. The lighting control unit, for the vehicle passing outside the illumination area,
The illumination light is reflected by the road surface and then irradiated toward at least a portion of the segment area corresponding to the front window glass, so that the illumination light is partially blocked or dimmed.
The road surface illumination device according to claim 1, further comprising control for switching the illumination states of the plurality of light sources. A communication unit is provided for communicating with the outside,
2. The road surface illumination device according to claim 1, wherein the vehicle detection unit acquires position information of a vehicle traveling on the road surface via the communication unit. The road surface illumination device according to any one of claims 1 to 6, characterized in that illumination light is emitted toward the road surface from road lights or street lights installed along the road surface. The road surface illumination device according to claim 7, characterized in that the lighting control unit controls the lighting of the plurality of light sources in a coordinated manner among the plurality of road lamps or street lamps lined up along the road surface. A road surface illumination method characterized by partially blocking or dimming illumination light irradiated toward a portion of the segment areas corresponding to the vehicle traveling on the road surface, out of illumination light irradiated toward illumination areas divided into a plurality of segment areas of the road surface, when the driving environment of the vehicle traveling on the road surface becomes wet.

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