JP7161337B2 - vehicle lamp - Google Patents

Description

The present invention relates to a vehicle lamp.

Vehicle lights play an important role in safe driving at night and in tunnels. If the area in front of the vehicle is illuminated brightly over a wide area, prioritizing the visibility of the driver, it will give glare to the drivers and pedestrians of the preceding and oncoming vehicles (hereinafter referred to as "front vehicles") in front of the vehicle. There's a problem.

In recent years, ADB (Adaptive Driving Beam) technology has been proposed that dynamically and adaptively controls a light distribution pattern based on the surrounding conditions of a vehicle. ADB technology detects the presence or absence of vehicles and pedestrians in front, and dims or turns off the area corresponding to the vehicles and pedestrians in front to reduce glare to drivers and pedestrians in front. be.

When the headlamp is turned on when it is snowing (or when it is raining), the snow grains reflect the beam, giving the driver glare, which in turn makes it difficult to see ahead. In order to solve this problem, the present inventors have investigated the control of detecting snow grains and shielding the surroundings from light.

A system capable of ultra-high-speed control can make the shaded area as close as possible to the size of a snowflake. However, such systems would be very expensive and impractical. Therefore, in a realistic system, the shaded area must be the extended range around the snow grains. If the light-shielding portion becomes large, the object overlapping behind the snowflake is not irradiated with the beam, resulting in a problem of reduced visibility.

The present invention has been made in view of such circumstances, and one exemplary purpose of certain aspects thereof is to improve visibility in front of the vehicle during snowfall.

One aspect of the present invention relates to a vehicle lamp. The vehicle lighting includes a light distribution controller that generates a light distribution pattern that includes a light-shielding portion with a margin area added around the snow grains, and a variable light distribution lamp that can generate a beam having an intensity distribution according to the light distribution pattern. , provided. At least one of the size and shape of the margin area is variable.

Any combination of the above constituent elements, and conversion of expressions of the present invention between methods, devices, systems, etc. are also effective as aspects of the present invention.

According to the present invention, visibility in front of the vehicle can be improved during snowfall.

1 is a block diagram of a vehicle lamp according to an embodiment; FIG. 2A and 2B are diagrams for explaining the operation of the vehicle lamp of FIG. 1. FIG. FIGS. 3(a) to 3(c) are enlarged views of the light shielding portion. FIG. 10 is a flow chart illustrating control of margin regions based on position; FIG. It is a photograph taken from a vehicle running during snowfall. FIGS. 6(a) and 6(b) are diagrams for explaining the improvement of the visibility of the gaze object. 1 is a block diagram of a vehicle lamp according to an embodiment; FIG.

(Overview of Embodiment)
A vehicle lamp according to an embodiment disclosed in this specification includes a light distribution controller that generates a light distribution pattern including a light-shielding portion with a margin area added around snow grains, and an intensity distribution controller that generates a light distribution pattern that includes a light-shielding portion with a margin area added around snow grains. a variable light distribution lamp capable of producing a beam having a distribution. In such a lighting device, if the margin area is increased, the followability to the snow grains is improved, but the surroundings of the snow grains become dark and the visibility decreases. Conversely, if the margin area is made smaller, the beam can be emitted around the snow grains, improving the visibility, but lowering the ability to follow the snow grains. Therefore, by controlling the margin area depending on the situation, it is possible to balance the followability and the visibility.

At least one of the size and shape of the margin area may be set according to its position. The trajectory of the running snow grain moves radially from the vanishing point. The closer to the vehicle, in other words, the farther away from the vanishing point, the longer the apparent length of the snowdrop trajectory (movement amount per unit time). Therefore, the margin area may be increased as the snow grains are farther from the vanishing point. As a result, it is possible to improve the ability to follow snow particles close to the vehicle.

Since snow falls from the sky, the vanishing point of snow grains is located above the image. Therefore, the size of the margin area may be smaller at the upper position of the snow grain and larger at the lower position. This simplifies control.

Also, the size and shape of the margin area may reflect the vehicle speed. As a result, it is possible to improve the followability of snow particles during high-speed driving, and to improve visibility during low-speed driving or when the vehicle is stopped.

The size and shape of the margin area may reflect the output of the raindrop sensor. It is difficult to accurately detect the size of snow grains. Therefore, by assuming that there is a correlation between the output of the raindrop sensor and the size of the snow grains, and adjusting the margin area, the size of the snow grains can be reflected in the size of the shaded portion.

In a range where there are objects to be watched, such as preceding vehicles, oncoming vehicles, and pedestrians (hereafter referred to as objects to be watched), it may be preferable to give priority to the visibility of the object to be watched over the ability to follow snow particles. . Conversely, in a range in which there is no gaze object, for example, in a range where the background is empty or an object is located far away, there is no problem in prioritizing followability. Therefore, the size of the margin area may be reduced in the range where the gaze object exists.

(Embodiment)
The above is the outline of the vehicle lamp. BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below based on preferred embodiments with reference to the drawings. The embodiments are illustrative rather than limiting the invention, and not all features and combinations thereof described in the embodiments are necessarily essential to the invention. The same or equivalent constituent elements, members, and processes shown in each drawing are denoted by the same reference numerals, and duplication of description will be omitted as appropriate. In addition, the scale and shape of each part shown in each drawing are set for convenience in order to facilitate the explanation, and should not be construed as limiting unless otherwise mentioned. Also, when terms such as "first" and "second" are used in this specification or in the claims, these terms do not represent any order or importance, and one configuration is different from another configuration. It is for distinguishing between

FIG. 1 is a block diagram of a vehicle lamp according to an embodiment. The vehicle lamp 100 includes a variable light distribution lamp 110 and a light distribution controller 140 .

The variable light distribution lamp 110 is a white light source, receives data indicating a light distribution pattern PTN from the light distribution controller 140, and emits a beam L3 having an intensity distribution (beam profile) corresponding to the light distribution pattern PTN, thereby An illuminance distribution corresponding to the light distribution pattern PTN is formed forward. The configuration of variable light distribution lamp 110 is not particularly limited, and may include, for example, a semiconductor light source such as an LD (laser diode) or LED (light emitting diode), and a lighting circuit that drives and lights the semiconductor light source. The variable light distribution lamp 110 may include a matrix type pattern forming device such as a DMD (Digital Mirror Device) or a liquid crystal device for forming an illuminance distribution according to the light distribution pattern PTN. The variable light distribution lamp 110 has a resolution to the extent that it can shade only the snow grain portion.

The light distribution controller 140 dynamically and adaptively controls the light distribution pattern PTN supplied to the variable light distribution lamp 110 . The light distribution pattern PTN is understood as a two-dimensional illuminance distribution of a white light irradiation pattern 902 formed on a virtual vertical screen 900 in front of the vehicle by the variable light distribution lamp 110 . The light distribution controller 140 can be composed of a digital processor. For example, it may be composed of a combination of a microcomputer including a CPU and a software program, or composed of an FPGA (Field Programmable Gate Array), an ASIC (Application Specified IC), or the like. may

In the present embodiment, light distribution controller 140 detects snow grains and generates light distribution pattern PTN in which portions corresponding to the snow grains are shaded. "Light shielding a certain part" includes not only the case where the luminance (illuminance) of that part is completely zero, but also the case where the luminance (illuminance) of that part is reduced.

The method of detecting snow grains is not limited. The light distribution controller 140 can detect snow grains by image processing based on a camera image IMG obtained by a camera (not shown). A snow grain detection algorithm is not particularly limited. Light distribution controller 140 may detect snow grains based on a plurality of consecutive frames of camera image IMG.

2A and 2B are diagrams for explaining the operation of the vehicle lamp 100 of FIG. 1. FIG. FIG. 2(a) shows the camera image IMG, and FIG. 2(b) shows the light distribution pattern PTN corresponding to the camera image of FIG. 2(a). A snow grain 6, a person 8, and a vehicle 10 are shown in the camera image IMG. The light distribution controller 140 detects the snow grains 6 in the camera image IMG and shields the corresponding portion (referred to as the light shielding portion) 7 of the light distribution pattern PTN.

The light distribution controller 140 may perform so-called ADB control. In this case, when a target such as the vehicle 10 that should not give glare is detected, the corresponding portion 11 is also shaded.

The light distribution pattern PTN is updated, for example, at a rate of 30 fps or more, and can move the light shielding portion 7 following the snow grains 6 . As a result, the reflected light of the snow grains 6 can be reduced, and forward visibility can be improved.

3A to 3C are enlarged views of the light blocking portion 7. FIG. The light-shielding portion 7 includes a portion X of the snow grain 6 and a margin area Y added therearound. The light-shielding portion 7 can be a rectangle whose long side is in the moving direction of the snow grains (indicated by the arrow in the figure) and whose short side is in the direction perpendicular to it. In this embodiment, at least one of the size and shape of the margin region Y is variable and dynamically and/or adaptively controlled. The light-shielding portion 7 in FIG. 3(a) has the smallest size of the margin region Y, which increases in order in FIGS. 3(b) and 3(c). 3A to 3C, the length W of the margin area Y in the width direction is fixed, and the length L of the margin area Y in the length direction is variable.

Specific control of the margin area Y will be described below.

1. Position-Based Control At least one of the size and shape of the margin region Y can be variable depending on the position of the snow grain (shading object).

FIG. 4 is a flow chart illustrating position-based margin region control. The front of the vehicle is photographed by a camera (S100). Then, snow grains are detected based on the camera image (S102). Then, the size and shape of the margin area Y are set according to the position of each snow grain (S104). Then, the light shielding area is set and the light distribution pattern is updated (S106). This operation is repeated.

FIG. 5 is a photograph taken from a vehicle running during snowfall. A snow grain moves radially from a certain vanishing point DP. In a photograph, snow grains are observed as trajectories in the exposure time. The length of the trajectory is the apparent moving distance (apparent speed) of the snowflake per unit time, and it can be said that the closer the trajectory is to the vanishing point DP, the shorter the trajectory is, and the farther from the vanishing point DP is, the longer the trajectory is. Therefore, the margin area Y may be increased as the snow grain is farther from the vanishing point. Thereby, followability can be improved.

The vanishing point DP may be detected by image processing according to the driving situation. Alternatively, since snow falls from the sky, the vanishing point DP of snow grains may be fixed. Then, it may be considered that the position of the snow grain is closer to the vanishing point DP at the top of the image, and farther from the vanishing point DP at the bottom. Based on this assumption, the size of the margin area Y may be made smaller as the position of the snow grain is higher and larger as the position of the snow grain is lower. This simplifies control.

In a range where there are objects to be watched, such as preceding vehicles, oncoming vehicles, and pedestrians (hereafter referred to as objects to be watched), it may be preferable to give priority to the visibility of the object to be watched over the ability to follow snow particles. . Conversely, in a range in which there is no gaze object, for example, in a range where the background is empty or an object is located far away, there is no problem in prioritizing followability. Therefore, the size of the margin area may be reduced in the range where the gaze object exists.

FIGS. 6(a) and 6(b) are diagrams for explaining the improvement of the visibility of the gaze object. FIG. 6(a) shows the camera image IMG, and FIG. 6(b) shows the light distribution pattern PTN. There is a high possibility that gaze object OBJ exists in area B including the road. On the contrary, since the background of the area A above the area B is the sky (or far), it can be said that the possibility that the gaze object exists is low.

Therefore, the light distribution controller 140 divides the area into an area B in which the gaze object can exist and an area A in which the gaze object cannot exist, and controls the margin area according to the position of the snowflake for the area A, and excludes the area B from the control. You may As for region B, the smaller the size of the margin region, the better. Furthermore, region B may be excluded from light shielding control based on snow grains.

2. Control based on driving conditions In addition to the position of the snow grains, driving conditions can be reflected in the control of the margin area. As an example, the apparent speed of snow particles increases as the vehicle speed v increases, and decreases as the vehicle speed v decreases. Therefore, the length L of the margin area may be controlled according to the vehicle speed v. The length L of the margin area can be expressed by a function f(y, v), where y is the y-coordinate of the snowflake and v is the vehicle speed.
L=f(y,v)
The light distribution controller 140 may calculate the value of the function f(y,v) or may have a lookup table.

In addition to or instead of the vehicle speed, the output of the raindrop sensor may be reflected in control of the margin area. When the output of the raindrop sensor is large, that is, when the amount of snowfall is large, the length L of the margin area may be relatively large. It is difficult to accurately detect the size of snow grains based only on the camera image IMG. Therefore, by assuming that there is a correlation between the output of the raindrop sensor and the size of the snow grains, and adjusting the margin area, the size of the snow grains can be reflected in the size of the shaded portion.

If the amount of snowfall is large, that is, the number of snow grains is large, setting the light shielding portion 7 for each of them would result in a huge computational cost. Therefore, when the output of the raindrop sensor is large, by enlarging the length L (and/or width W) of the marginal area, it is possible to collectively process multiple snowflakes in one shaded area 7. There are also advantages.

Next, a method for detecting snow grains will be described. FIG. 7 is a block diagram of a vehicle lamp 100A according to one embodiment. The vehicle lamp 100</b>A includes an infrared illumination 120 and an infrared camera 130 . The infrared light 120 and the infrared camera 130 may be built in the housing (lamp body) of the vehicle lamp 100, or may be externally attached. The infrared illumination 120 may be built into the housing, and the infrared camera 130 may be attached to the rear side of the rearview mirror.

The infrared illumination 120 is a probe light source that emits infrared probe light L1 in front of the vehicle. The probe light L1 may be near-infrared light or light with a longer wavelength. The infrared camera 130 captures the reflected light L2 of the probe light L1 from the object 2 in front of the vehicle. The infrared camera 130 only has to be sensitive to at least the wavelength range of the probe light L1, and is preferably insensitive to visible light.

Light distribution controller 140 detects snow grains by image processing based on camera image IMG obtained by infrared camera 130 .

Advantages of the vehicle lamp 100A will be described. When white (visible) probe light is used to detect snow grains, the snow grains shine white every time the probe light is irradiated, causing glare and poor visibility. According to this embodiment, since infrared rays are used as probe light, there is an advantage that glare can be prevented.

In addition, since infrared light is used as the probe light, there is an advantage that even if the probe light is emitted continuously, it is difficult for the driver to recognize it. Therefore, it is possible to track and detect snow particles moving at high speed.

The present invention has been described above based on the embodiments. It should be understood by those skilled in the art that this embodiment is merely an example, and that various modifications can be made to the combination of each component and each treatment process, and that such modifications are within the scope of the present invention. be. Such modifications will be described below.

(Modification 1)
In the embodiment, light shielding control for snowdrops has been described, but raindrops may also be subject to light shielding control.

(Modification 2)
In the embodiment, only the length L of the margin area is variable, but in addition, the width W may be variable, and the shape of the margin area may be variable.

(Modification 3)
Although infrared rays are used as the probe light in the embodiments, the present invention is not limited to this. It is also possible to detect snow grains by using the beam L3 emitted by the variable light distribution lamp 110 as probe light. In this case, if the irradiation time of the probe light is long, glare is caused to the driver. Therefore, the emission time of the probe light may be shortened to such an extent that the reflected light L2 cannot be detected by the driver.

(Modification 4)
Although the present invention has been described using specific terms based on the embodiment, the embodiment only shows one aspect of the principle and application of the present invention, and the embodiment does not include the claims. Many variations and rearrangements are permissible without departing from the spirit of the invention as defined in its scope.

REFERENCE SIGNS LIST 100 vehicle lamp 110 variable light distribution lamp 120 infrared lighting 130 infrared camera 140 light distribution controller L1 probe light L2 reflected light L3 beam

Claims (6)

a light distribution controller that generates a light distribution pattern including a light-shielding portion with a margin area added around the snow grain;
a variable light distribution lamp capable of generating a beam having an intensity distribution according to the light distribution pattern;
with
at least one of the size and shape of the margin region is variable;
at least one of the size and shape of the margin area is dependent on its location;
The vehicular lamp, wherein the position of the snow grain in the margin area is smaller toward the upper side and larger toward the lower side. a light distribution controller that generates a light distribution pattern including a light-shielding portion with a margin area added around the snow grain;
a variable light distribution lamp capable of generating a beam having an intensity distribution according to the light distribution pattern;
with
at least one of the size and shape of the margin region is variable;
at least one of the size and shape of the margin area is dependent on its location;
The vehicular lamp, wherein the margin area increases with distance from the vanishing point of the snow grain. 3. The vehicle lamp according to claim 1 , wherein at least one of the size and shape of the margin area reflects vehicle speed. a light distribution controller that generates a light distribution pattern including a light-shielding portion with a margin area added around the snow grain;
a variable light distribution lamp capable of generating a beam having an intensity distribution according to the light distribution pattern;
with
at least one of the size and shape of the margin region is variable;
The vehicular lamp, wherein at least one of the size and shape of the margin area reflects vehicle speed. 5. The vehicle lamp according to claim 1 , wherein at least one of the size and shape of said margin area reflects the output of a raindrop sensor. 6. The light distribution controller according to any one of claims 1 to 5 , wherein the light distribution controller detects the snow grains based on an image captured by an infrared camera of reflected light obtained in response to the probe light emitted by the infrared illumination. 1. The vehicle lamp according to .

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