Headlamp system for vehicle

Abstract

To achieve both brightness securement at a front near side of an own vehicle and glare prevention for other vehicles during rainfall.SOLUTION: A headlamp system for a vehicle includes: a sensor configured to detect at least one of rainfall in the periphery of an own vehicle and a road surface wet state; and a controller connected to a pair of headlamps and the sensor respectively, and configured to control operation of the pair of headlamps. The pair of headlamps are configured to at least radiate a low beam to the front side of the own vehicle and change an illumination intensity of a partial range within an irradiation range of the low beam. The controller controls an irradiation state of the pair of headlamps so that an illumination intensity of the partial range of the low beam is relatively increased when a water screen is estimated to arise.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a vehicle headlamp system. [Background technology]

[0002] Japanese Patent No. 7177802 (Patent Document 1) describes a vehicle lamp that emits an additional low beam in addition to a normal low beam to ensure brightness on the near side of the vehicle (the side closest to the vehicle). The illumination range of this additional low beam is set by each of the left and right lamp units so that an optimal illumination state can be obtained, for example, within a range of 5 to 15 mm in front of the vehicle and 3.5 m on both sides.

[0003] When a water film forms on the road surface due to rainfall or other reasons, the amount of low beam light that is specularly reflected and travels farther increases. This results in insufficient brightness in front of the vehicle compared to when there is no water film and the low beam light is scattered by the road surface. To address this issue, the brightness in front of the vehicle can be ensured by using the supplemental low beam described above or by other means to increase the light irradiated to a portion of the normal low beam illumination range. However, depending on the relative position of the vehicle and the preceding vehicle or oncoming vehicle (hereinafter collectively referred to as "other vehicles"), the reflected light from the supplemental low beam or other light that specularly reflects off the road surface may cause glare to other vehicles. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 7177802 Summary of the Invention [Problem to be solved by the invention]

[0005] One of the objectives of a specific aspect of the present disclosure is to provide a technology that can ensure brightness on the near side ahead of a vehicle while preventing glare on other vehicles during rainy weather, etc. [Means for solving the problem]

[0006] A vehicle headlamp system according to one aspect of the present disclosure includes: a pair of headlights disposed at the front of the host vehicle; a sensor configured to detect at least one of rainfall and a wet road condition around the vehicle; a controller connected to each of the pair of headlights and the sensor and configured to be able to control the operation of the pair of headlights; Including, the pair of headlights are configured to be able to irradiate at least a low beam ahead of the vehicle and to change the illuminance of a part of an illumination range of the low beam, the controller controls the illumination state of the pair of headlights so as to relatively increase the illuminance of the partial range when it is estimated that a water film is generated based on the detection result of the sensor. A vehicle headlight system.

[0007] According to the above configuration, it is possible to ensure brightness on the near side ahead of the vehicle and prevent glare on other vehicles when it is raining or the like. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a block diagram for explaining the configuration of a vehicle headlamp system according to the first embodiment. [Figure 2] 2(A) to 2(C) are schematic diagrams for explaining configuration examples of the left and right headlights. [Figure 3] 3A and 3B are diagrams for explaining the irradiation range of the additional low beam in the first embodiment. [Figure 4]4A and 4B are overhead views for explaining the irradiation ranges of the additional low beams ALB1 and ALB2. [Figure 5] 5(A) and 5(B) are diagrams showing an example of the illumination range of the additional low beam. [Figure 6] 6(A) and 6(B) are overhead views for explaining the irradiation ranges of the additional low beams ALB1 and ALB2. [Figure 7] Fig. 7(A) is a diagram for explaining a method for setting the right boundary of the irradiation range of the additional low beam ALB1, and Fig. 7(B) is a diagram for explaining a method for setting the left boundary of the irradiation range of the additional low beam ALB1. [Figure 8] Fig. 8(A) is a diagram for explaining a method for setting the upper boundary of the irradiation range of the additional low beam ALB1, and Fig. 8(B) is a diagram showing the left boundary, right boundary, and upper boundary of the irradiation range of the additional low beam ALB1. [Figure 9] FIG. 9 is a flowchart showing the operation procedure of the vehicle headlamp system 1 of the first embodiment. [Figure 10] FIG. 10 is a schematic diagram for explaining a situation in which the host vehicle is traveling on a left-hand curve road and an oncoming vehicle is present. [Figure 11] FIG. 11 is a block diagram showing the configuration of a vehicle headlamp system according to the second embodiment. [Figure 12] FIG. 12 is a flowchart showing the operation procedure of the vehicle headlamp system 1A of the second embodiment. [Figure 13] FIG. 13 is a flowchart showing another operation procedure of the vehicle headlamp system 1A of the second embodiment. [Figure 14] FIG. 14 is a block diagram showing the configuration of a vehicle headlamp system according to the third embodiment. [Figure 15] Fig. 15(A) is a bird's-eye view showing the relative positional relationship between the host vehicle and an oncoming vehicle, and Fig. 15(B) and Fig. 15(C) are side views showing the relative positional relationship between the host vehicle and an oncoming vehicle. [Figure 16] Fig. 16(A) is a diagram showing the definition of the left-right angle θ1, and Fig. 16(B) is a diagram showing the definition of the up-down angle θ2. [Figure 17] FIG. 17 is a diagram for explaining the correspondence relationship on the screen between the left-right angle θ1 and the up-down angle θ2. [Figure 18] Fig. 18(A) is a diagram showing the transition of eye position on a screen, and Fig. 18(B) is a diagram showing an example of the illumination range of the additional low beam including the shaded area. [Figure 19] Fig. 19(A) is a diagram showing the definition of the left-right angle θ3, and Fig. 19(B) is a diagram showing the definition of the up-down angle θ4. [Figure 20] FIG. 20 is a flowchart showing the operation procedure of the vehicle headlamp system 1B of the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] (First embodiment) FIG. 1 is a block diagram illustrating the configuration of a vehicle headlight system according to a first embodiment. The vehicle headlight system 1 according to the first embodiment includes a controller 10, a pair of headlights, a left headlight 11L and a right headlight 11R, a rainfall sensor 12, and a road surface sensor 13. The controller 10 is connected to a lamp switch 14 provided on the vehicle and also to the rainfall sensor 12 and the road surface sensor 13. The controller 10 is also connected to the left headlight 11L and the right headlight 11R. In this specification, "connected" does not necessarily mean a direct connection via wiring, a communication line, or the like, but also includes an indirect connection such that an electrical signal can be received via another control device (not shown). In the first embodiment, the rainfall sensor 12 and / or the road surface sensor 13 correspond to "sensors."

[0010] The controller 10 controls the overall operation of the vehicle headlamp system 1, and is realized by executing a predetermined operation program on a computer having, for example, a processor and a memory. The controller 10 has, as functional blocks, an illumination state setting unit (illumination state setting function) 20 and a road surface condition estimating unit (road surface condition estimating function) 21.

[0011] The illumination state setting unit 20 sets the light illumination state of each of the left headlight 11L and the right headlight 11R based on the operation state of the lamp switch 14 and the estimation result of the road surface condition estimation unit 21, and supplies a control signal according to the set content to each of the left headlight 11L and the right headlight 11R.

[0012] The road surface condition estimation unit 21 estimates the condition of the road surface in the lane in which the vehicle is traveling based on the detection results of the rainfall sensor 12 and the road surface sensor 13. Specifically, the road surface condition estimation unit 21 estimates that a water film has formed on the road surface when there is rainfall (when the amount of rainfall is equal to or greater than a predetermined reference value) or when the road surface is wet. The presence or absence of rainfall and the amount of rainfall are determined based on the detection results of the rainfall sensor 12. The presence or absence of a wet road surface is determined based on the detection results of the road surface sensor 13.

[0013] The left and right headlights 11L and 11R are each installed at the front of the vehicle and are configured to be able to emit light ahead of the vehicle. The left headlight 11L is installed on the left front side of the vehicle 100, and the right headlight 11R is installed on the right front side of the vehicle. The left headlight 11L has a low beam unit 31L, an additional low beam unit 32L, and a high beam unit 33L. The right headlight 11R has a low beam unit 31R, an additional low beam unit 32R, and a high beam unit 33R.

[0014] The low beam units 31L and 31R are each configured to emit a low beam (passing light) ahead of the vehicle. In the following description, the combined light of the lights emitted from the low beam units 31L and 31R may be referred to as a low beam, and the light emitted from either the low beam unit 31L or 31R may be referred to as a low beam.

[0015] The additional low beam units 32L and 32R are each configured to emit an additional low beam ahead of the vehicle. The additional low beam here refers to light that is emitted to a portion of the low beam illumination range to relatively increase the illuminance in that portion. Note that "relatively increasing the illuminance" means that the illuminance in that portion of the range is increased compared to when the low beam is illuminated without the additional low beam.

[0016] High beam units 33L and 33R are units configured to emit high beams (driving lights) ahead of the vehicle. In the following description, the combined light emitted from high beam units 33L and 33R may be referred to as a high beam, or the light emitted from either high beam unit 33L or 33R may be referred to as a high beam. High beam units 33L and 33R may be units capable of emitting selective high beams with a dimming range set according to the positions of oncoming vehicles and leading vehicles, etc.

[0017] The rainfall sensor 12 is a sensor that detects the presence or absence of rainfall and the amount of rainfall around the vehicle. For example, an optical sensor that detects raindrops by irradiating the windshield with light such as infrared light and detecting the reflected light can be used as the rainfall sensor 12.

[0018] The rainfall sensor 12 may be a sensor that detects whether or not it is raining based on an image of the surroundings of the vehicle captured by a camera (not shown).The rainfall sensor 12 may also be a sensor that acquires weather information from an external source via wireless communication.

[0019] The road surface sensor 13 is a sensor that detects the road surface condition of the lane the vehicle is traveling in, specifically, whether the road surface is wet or not. As the road surface sensor 13, for example, an optical sensor that detects the road surface condition by irradiating light such as a laser beam onto the road surface and detecting the reflected light can be used.

[0020] Note that a sensor that detects road surface conditions based on an image of the road surface captured by a camera (not shown) may be used as the road surface sensor 13. Alternatively, a sensor that detects road surface conditions by detecting acceleration in the circumferential direction (rotational direction) of the tire using an acceleration sensor attached to the inner surface of the tire of the vehicle may be used as the road surface sensor 13.

[0021] 2(A) to 2(C) are schematic diagrams for explaining configuration examples of the left and right headlights. Note that each figure shows a configuration example of the left headlight 11L, but the right headlight 11R has a similar configuration. The configuration example shown in FIG. 2(A) corresponds to the left headlight 11L shown in FIG. 1, and the configuration examples shown in FIGS. 2(B) and 2(C) are modified embodiments that can achieve the same function.

[0022] FIG. 2(A) shows a schematic configuration of the left headlamp 11L in the vehicle lighting system 1 shown in FIG. 1. Specifically, the low beam unit 31L irradiates a low beam LB ahead of the vehicle, and the high beam unit 33L irradiates a high beam HB ahead of the vehicle. The high beam HB may be an optional high beam (ADB). The additional low beam unit 32L irradiates an additional low beam ALB within the illumination range of the low beam LB. In this configuration example, the low beam units 31L and 31R correspond to the "first unit," and the additional low beam units 32L and 32R correspond to the "second unit."

[0023] In the configuration example shown in Figure 2(B), the function of the additional low beam unit 32L is replaced by a high beam unit 33L. In this configuration example, the illumination range of the high beam HB emitted by the high beam unit 33L is expanded so that its bottom edge is closer to the bottom edge of the low beam LB compared to the configuration example shown in Figure 2(A). The additional low beam ALB is formed by relatively increasing the illuminance of a portion of the expanded illumination range of the high beam HB. In this configuration example, the low beam units 31L and 31R correspond to the "first unit," and the high beam units 33L and 33R correspond to the "second unit."

[0024] The configuration example shown in FIG. 2(C) is a configuration example in which the functions of the low beam unit 31L, the high beam unit 32L, and the additional low beam unit 32R are integrated into the high-definition light source unit 34L. In this configuration example, the illumination range of the high beam HB emitted by the high-definition light source unit 34L is expanded so that its bottom edge is closer to the bottom edge of the low beam LB compared to the configuration example shown in FIG. 2(A). The additional low beam ALB is formed by relatively increasing the illuminance of a portion of the expanded illumination range of the high beam HB. The low beam LB is also formed by the high-definition light source unit 34L. In this configuration example, the high-definition light source units 34L and 34R correspond to the "third unit."

[0025] In each of the above configuration examples, the high beam unit 32L (32R) capable of emitting selective high beams and the high-definition light source unit 34L (34R) can each be configured using, for example, a light source capable of emitting laser light and an optical deflector such as a MEMS mirror that scans the laser light. Alternatively, the high beam unit 32L, etc. can be configured using a light source (LED, laser, etc.) and a liquid crystal element that can partially control the transmittance of the light emitted from the light source. Furthermore, the high beam unit 32L, etc. can also be configured using a light source in which many extremely small LEDs are densely mounted and a lens optical system that projects the light emitted from the light source.

[0026] 3A and 3B are diagrams illustrating the irradiable range of the supplemental low beam in the first embodiment. Each diagram illustrates the irradiable range of the supplemental low beam on a screen assumed to be positioned vertically at a predetermined position (e.g., 25 m ahead) in front of the vehicle, with a pattern added. Specifically, FIG. 3A illustrates the irradiable range of the supplemental low beam ALB1 by the supplemental low beam unit 32L of the left headlight 11L, and FIG. 3B illustrates the irradiable range of the supplemental low beam ALB2 by the supplemental low beam unit 32R of the right headlight 11R. In each diagram, the cutoff line CL corresponds to the upper end position of the low beam. This specification assumes that the vehicle is legally required to drive on the left side of the road. In other words, in this specification, an oncoming vehicle corresponds to the "first vehicle ahead," and a leading vehicle corresponds to the "second vehicle ahead."

[0027] In the first embodiment, the additional low beams ALB1 and ALB2 are irradiated when rainfall and / or a wet road surface is detected, and it is estimated that a water film has formed on the road surface. At this time, the illumination ranges of the additional low beams ALB1 and ALB2 are set so as not to cause glare to drivers of oncoming vehicles or preceding vehicles due to specular reflection (regular reflection) of the additional low beams ALB1 and ALB2 on the road surface.

[0028] Using the installation positions of each additional low beam unit 32L, 32R as a reference, the eye position of the driver of an oncoming vehicle that is assumed to be present (first position) and the position of the mirror (rear mirror or side mirror) of a preceding vehicle that is assumed to be present (second position) are respectively set, and the boundary between the positions where reflected light due to specular reflection on the road surface enters each position and the positions where it does not enter is calculated, and the illumination range is set based on this boundary.

[0029] Specifically, as shown in Fig. 3(A), the irradiable range of the additional low beam ALB1 is defined by a left boundary 50, a right boundary 51, an upper boundary 52, and a lower boundary 53. Similarly, as shown in Fig. 3(B), the irradiable range of the additional low beam ALB2 is defined by a left boundary 60, a right boundary 61, an upper boundary 62, and a lower boundary 63.

[0030] The left boundaries 50 and 60 define the left end of the illumination range and are the boundaries between positions where reflected light is incident on a preceding vehicle assumed to be located relatively to the left of the vehicle and where it is not incident thereon. The right boundaries 51 and 61 define the right end of the illumination range and are the boundaries between positions where reflected light is incident on an oncoming vehicle assumed to be located relatively to the right of the vehicle and where it is not incident thereon.

[0031] The left boundaries 50, 60 and the right boundaries 60, 61 are preferably set based on numerical conditions that do not cause glare to the driver of a preceding vehicle or an oncoming vehicle, even if the preceding vehicle or the oncoming vehicle is not a standard vehicle but a large vehicle such as a truck. Furthermore, the left boundaries 50, 60 and the right boundaries 60, 61 are preferably set so that the light is directed upward from the preceding vehicle or the oncoming vehicle. This is to prevent additional glare from being generated by the light hitting the body of the oncoming vehicle. A detailed method for setting the left boundaries 50, 60 and the right boundaries 60, 61 will be described later.

[0032] Each of the upper boundaries 52, 62 defines the upper end of the illumination range and is preferably set below the upper end of the low beam (i.e., the cut-off line CL). This is because the purpose of the additional low beams ALB1, ALB2 is to illuminate the road surface. Each of the lower boundaries 53, 63 defines the lower end of the illumination range and is preferably set at a position visible to the driver of the vehicle (for example, 5 m ahead of the vehicle).

[0033] The distance between the upper boundary 52 and the lower boundary 53, and the distance between the upper boundary 62 and the lower boundary 63 can be set so as to illuminate an area between 5 m and 35 m ahead of the vehicle, for example. Specifically, if the additional low beam units 32L and 32R are installed at a height of 0.9 m, the distance can be set within a range of -1.5° to -10.0° (1.5D to 10.0D). If the additional low beam units 32L and 32R are installed at a height of 0.6 m, the distance can be set within a range of -1.0° to -6.8° (1.0D to 6.8D). In other words, the distance can be set according to the vehicle model and specifications. Taking the preceding vehicle into consideration, the lower boundaries 53 and 63 are preferably set at -4.0° (4.0D).

[0034] The shape of the illumination range on the screen will be described in more detail. As shown in FIG. 3(A), the left boundary 50 and the right boundary 51 have different inclination angles relative to the vertical direction. Similarly, as shown in FIG. 3(B), the left boundary 60 and the right boundary 61 have different inclination angles relative to the vertical direction. Specifically, compared to when illuminating the entire lane width of the host vehicle's traveling lane, which is defined between the left edge 70 and the right edge 71 of the lane, the angle between the left boundary 50, 60 and the horizontal direction (left-right direction in the figure) is larger than the angle between the left edge 70 and the horizontal direction. Similarly, the angle between the right boundary 51, 61 and the horizontal direction (left-right direction in the figure) is larger than the angle between the right edge 71 and the horizontal direction. Furthermore, the length of each of the upper boundaries 52, 62 and the lower boundaries 53, 63 is shorter than the lane width (i.e., the length between the left edge 70 and the right edge 71 of the lane).

[0035] By irradiating each of the additional low beams ALB1 and ALB2 within the irradiation range thus set, it is possible to prevent glare caused by specular reflection of each of the additional low beams ALB1 and ALB2 on the road surface from being directed at drivers of oncoming vehicles. Note that the shapes of each of the additional low beams ALB1 and ALB2 on the screen may be asymmetrical. Furthermore, the luminous intensities of each of the additional low beams ALB1 and ALB2 may be different.

[0036] 4(A) and 4(B) are overhead views illustrating the illumination ranges of the additional low beams ALB1 and ALB2. Each figure shows a schematic plan view of the host vehicle 100, an oncoming vehicle 101, and a preceding vehicle 102 viewed from above. As shown in each figure, it is assumed that the host vehicle 100 is traveling in a lane defined by a left edge 70 and a right edge 71 of the lane, and that the oncoming vehicle 101 is present in the oncoming lane to the right of the host vehicle 100's lane, and the preceding vehicle 102 is present in the lane to the left of the host vehicle 100's lane.

[0037] The additional low beam ALB1 emitted from the left headlight 11L of the vehicle 100 is included in the illumination range of the low beam LB. The additional low beam ALB1 is emitted in the direction of the optical axis a1 of the additional low beam unit 32L. In the illustrated example, the left boundary 50 and the right boundary 51 of the illumination range of the additional low beam ALB1 are approximately parallel to the optical axis a1 and are set inside the left edge 70 and the right edge 71 of the lane. The position of the left boundary 50 is set to correspond to the mirror position of the preceding vehicle 102, so that light reflected by road surfaces does not enter the preceding vehicle 102. The right boundary 51 is set to correspond to the eye position of the driver of the oncoming vehicle 101, so that light reflected by road surfaces does not enter the oncoming vehicle 101. In this example, the additional low beam ALB1 is illuminated over a wide range so that its left and right ends approximately coincide with the left edge boundary 50 and the right edge boundary 51 of the illumination range, respectively.

[0038] Furthermore, the additional low beam ALB2 emitted from the right headlight 11R of the vehicle 100 is included within the illumination range of the low beam LB. The additional low beam ALB2 is emitted in the direction of the optical axis a2 of the additional low beam unit 32R. In this example, the left boundary 60 and the right boundary 61 of the illumination range of the additional low beam ALB2 are approximately parallel to the optical axis a2 and are set inside the left edge 70 and the right edge 71 of the lane. The position of the left boundary 60 is set to correspond to the mirror position of the preceding vehicle 102, so that light reflected by road surfaces does not enter the preceding vehicle 102. The right boundary 61 is set to correspond to the eye position of the driver of the oncoming vehicle 101, so that light reflected by road surfaces does not enter the oncoming vehicle 101. In this example, the additional low beam ALB2 is emitted over a wide range so that its left and right ends approximately coincide with the left and right boundaries 60 and 61 of the illumination range, respectively.

[0039] 5(A) and 5(B) are diagrams showing an example of the illumination range of the supplemental low beam. Each diagram shows the illumination range of the supplemental low beam on a screen assumed to be positioned vertically at a predetermined position ahead of the vehicle (e.g., 25 m ahead), with a pattern added. FIGS. 6(A) and 6(B) are overhead views for explaining the illumination range of each supplemental low beam ALB1, ALB2. FIGS. 5(A) and 6(A) show the illumination range of the supplemental low beam ALB1 by the supplemental low beam unit 32L of the left headlight 11L, while FIGS. 5(B) and 6(B) show the illumination range of the supplemental low beam ALB2 by the supplemental low beam unit 32R of the right headlight 11R. The symbols in the diagrams are the same as those described above, and detailed descriptions will be omitted.

[0040] The additional low beam ALB1 shown in Figures 5(A) and 6(A) has an illumination range set inside the illumination range defined by left boundary 50, right boundary 51, upper boundary 52, and lower boundary 53. Compared to the additional low beam ALB1 shown in Figures 3(A) and 4(A) above, the illumination range is set to be relatively small and closer to the center of the illumination range. The shape of the additional low beam ALB1 on the screen is rectangular with its long sides approximately parallel to the vertical direction and its short sides approximately parallel to the horizontal direction.

[0041] The additional low beam ALB2 shown in Figures 5(B) and 6(B) has an illumination range set inside the illumination range defined by a left boundary 60, a right boundary 61, an upper boundary 62, and a lower boundary 63. Compared to the additional low beam ALB2 shown in Figures 3(B) and 4(B) above, the area of ​​the illumination range is set relatively smaller and is set closer to the center of the illumination range. The shape of the additional low beam ALB2 on the screen is rectangular with its long sides approximately parallel to the vertical direction and its short sides approximately parallel to the horizontal direction.

[0042] In addition, the additional low beam ALB1 shown in Figure 5(A) etc. and the additional low beam ALB2 shown in Figure 5(B) etc. have symmetrical shapes. As in this example, the additional low beams ALB1 and ALB2, which have a small area relative to the irradiable range and are set closer to the center of the irradiable range, are suitable for use as a fixed light distribution regardless of the situation of preceding or oncoming vehicles, for example.

[0043] FIG. 7(A) is a diagram illustrating a method for setting the right boundary of the illumination range of the supplemental low beam ALB1. FIG. 7(B) is a diagram illustrating a method for setting the left boundary of the illumination range of the supplemental low beam ALB1. Here, the presence of an oncoming vehicle is assumed to the right of the host vehicle, and the eye position of the driver is estimated. The presence of a preceding vehicle is assumed to the left of the host vehicle, and the mirror position is estimated. In this embodiment, the eye position of the driver of a large vehicle such as a truck is assumed to prevent glare from occurring even in large vehicles. The eye position of the driver of a large vehicle is, for example, 2.2 m above ground level.

[0044] As an example, the line segment e1 in FIG. 7A indicates the driver's eye position when an oncoming vehicle is located anywhere between 220 m and 15 m ahead relative to the vehicle. When the additional low beam emitted from additional low beam unit 32L is specularly reflected on the road surface and reflected light is incident on the eye position indicated by line segment e1, the reflection position of the reflected light on the road surface becomes the right boundary 51 of the illumination range. In other words, right boundary 51 is determined based on a line segment that is a collection of reflection positions (road surface coordinates) on the road surface between 220 m and 15 m ahead. If only oncoming vehicles are considered, the illumination range becomes the range d1 (shown with a pattern) to the left of right boundary 51 and below cutoff line CL.

[0045] Similarly, as an example, the mirror position when the preceding vehicle is located somewhere between 220 m and 15 m ahead relative to the host vehicle is shown by line segment e2 in Figure 7(B). When the additional low beam emitted from the position of additional low beam unit 32L is specularly reflected on the road surface and reflected light is incident on the mirror position shown by line segment e2, the reflection position of the reflected light on the road surface becomes the left boundary 50 of the illumination range. In other words, left boundary 50 is determined based on a line segment that is a collection of reflection positions (road surface coordinates) on the road surface between 220 m and 15 m ahead. If only the preceding vehicle is considered, the illumination range becomes the range d2 (shown with a pattern) to the right of left boundary 50 and below cutoff line CL.

[0046] The specific positions of the left boundary 50 and the right boundary 51 can be calculated by setting conditions such as the installation position (ground clearance) of the additional low beam unit 32L, the vehicle width, and the lane width based on general numerical values. A detailed calculation example will be described in detail in the third embodiment described later. Note that, although not explained further, the left boundary 60 and the right boundary 61 of the additional low beam ALB2 by the additional low beam unit 32R can be obtained in a similar manner.

[0047] 7(C) is a diagram showing the left and right boundaries of the illumination range of the additional low beam ALB1. Range d3 is the range defined by the left boundary 50, the right boundary 51, and the cutoff line CL, i.e., the overlapping range of the above-mentioned ranges d1 and d2. When a preceding vehicle in the vehicle's lane is not taken into consideration, range d3 can be used as the illumination range.

[0048] FIG. 8(A) is a diagram for explaining a method for setting the upper boundary of the illumination range of the additional low beam ALB1. Here, a preceding vehicle in the driving lane of the host vehicle is assumed, and the mirror position of the preceding vehicle is estimated. In this embodiment, the mirror position of a large vehicle such as a truck is assumed to prevent glare from occurring even in the case of such a large vehicle. The mirror position of a large vehicle is, for example, 2.2 m above ground level.

[0049] As an example, the position of the mirror when a preceding vehicle is 220 m ahead is shown in Figure 8(A) by line segment e3. When the additional low beam emitted from the position of additional low beam unit 32L is specularly reflected on the road surface and reflected light is incident on the mirror position shown by line segment e3, the position of the reflected light on the road surface becomes upper boundary 52 of the illumination range. If only preceding vehicles in the host vehicle's driving lane are considered, the illumination range is a range d4 (shown with a pattern) below upper boundary 52 and below cutoff line CL.

[0050] The specific position of the upper boundary 52 can be calculated by setting conditions such as the installation position (ground clearance) of the additional low beam unit 32L, the vehicle width, and the lane width based on general numerical values. Note that, although not explained here, the upper boundary 62 of the additional low beam ALB2 by the additional low beam unit 32R can be calculated in a similar manner.

[0051] FIG. 8(B) is a diagram showing the left, right, and upper boundaries of the illumination range of the additional low beam ALB1. Range d5 is the overlapping range of range d3 (see FIG. 7(C)) defined by left boundary 50 and right boundary 51 and range d4 defined by upper boundary 52. ​​By using range d5 as the illumination range, it is possible to obtain an illumination range that assumes a preceding vehicle in the left lane of the host vehicle, a preceding vehicle in the host vehicle's lane, and an oncoming vehicle to the right of the host vehicle. As described above, the lower end of range d5 (i.e., lower boundary 53) can be appropriately set to a position that is visible to the driver of the host vehicle.

[0052] 9 is a flowchart showing the operation procedure of the vehicle headlamp system 1 according to the first embodiment. In the first embodiment, a case where an additional low beam with a preset fixed illumination range is used will be described. Note that the order of the processes shown here can be changed as long as no contradictions or inconsistencies occur in the results of the information processing, and other processes not explicitly shown here can also be added.

[0053] When the driver operates the lamp switch 14 of the vehicle to instruct illumination of the headlights (step S11; YES), the illumination state setting unit 20 of the controller 10 supplies a control signal to the low beam units 31L, 31R of the headlights 11L, 11R to illuminate the low beams. As a result, the low beams are illuminated ahead of the vehicle (step S12). Note that the illumination state setting unit 20 also supplies an appropriate control signal to the high beam units 33L, 33R.

[0054] Furthermore, if the road surface condition estimation unit 21 estimates the road surface conditions based on the detection results of the rainfall sensor 12 and the road surface sensor 13 and determines that there is at least one of rainfall around the vehicle and a wet road surface on which the vehicle is traveling, and that a water film has formed on the road surface (step S13; YES), the illumination state setting unit 20 supplies control signals to the additional low beam units 32L and 32R of the headlights 11L and 11R to cause them to emit additional low beams. This causes the additional low beams to be emitted in front of the vehicle (step S14). Here, the additional low beams are emitted within a preset fixed illumination range within the illumination range of the additional low beams (see, for example, FIGS. 5A and 5B). Then, the process returns to step S11.

[0055] On the other hand, in the above-mentioned step S11, if the driver operates the lamp switch 14 of the vehicle to instruct the headlights to stop illuminating (step S11; NO), the illumination state setting unit 20 of the controller 10 supplies a control signal to turn off all units, such as the low beam units 31L, 31R of each headlight 11L, 11R. As a result, all units of each headlight 11L, 11R are turned off (step S15). Thereafter, the process returns to step S11.

[0056] Furthermore, in the above-mentioned step S13, if it is estimated that there is no rainfall around the vehicle, or that the road surface on which the vehicle is traveling is not wet and no water film is present on the road surface (step S13; NO), the illumination state setting unit 20 supplies a control signal to the additional low beam units 32L, 32R of each headlamp 11L, 11R to turn off the additional low beams. This turns off the additional low beams in front of the vehicle (step S16). Note that the additional low beams may be completely turned off or may be controlled to reduce illuminance to an extremely low level (the same applies below). Then, the process returns to step S11.

[0057] According to the first embodiment as described above, a technique is provided that can ensure brightness on the near side ahead of the vehicle and prevent glare on other vehicles when it is raining or the like.

[0058] (Second embodiment) In the vehicle headlamp system of the first embodiment described above, it is also preferable to control the vehicle so that the additional low beam is not emitted when the vehicle 100 is traveling on a left-hand curve and an oncoming vehicle 101 is present, as shown in the schematic diagram of Fig. 10. A vehicle headlamp system that performs such control will be described in detail below. Note that descriptions of matters common to the first embodiment will be omitted where appropriate.

[0059] 11 is a block diagram showing the configuration of a vehicle headlight system according to the second embodiment. The basic configuration of the illustrated vehicle headlight system 1A is the same as that of the vehicle headlight system 1 according to the first embodiment, but differs in that it includes a camera 15 and a millimeter-wave radar 16, each connected to a controller 10, and that it is configured to be able to acquire road information from a navigation system (not shown) or the like. The main differences will be described below. In the second embodiment, the rainfall sensor 12 and / or the road surface sensor 13 correspond to the "first sensor."

[0060] The camera 15 detects oncoming vehicles, preceding vehicles, etc. based on images obtained by capturing images of the space ahead of the host vehicle. The millimeter-wave radar 16 detects objects such as oncoming vehicles and preceding vehicles that exist ahead of the host vehicle by emitting radio waves (e.g., microwaves) into the space ahead of the host vehicle and detecting the reflected waves. In the second embodiment, the camera 15 and / or the millimeter-wave radar 16 correspond to a "second sensor."

[0061] 12 is a flowchart showing the operation procedure of the vehicle headlamp system 1A of the second embodiment. In the second embodiment, a case where an additional low beam with a preset fixed illumination range is used will also be described. It should be noted that the order of the processes shown here can be changed as long as no contradictions or inconsistencies occur in the results of the information processing, and other processes not explicitly shown here can also be added.

[0062] When the driver operates the lamp switch 14 of the vehicle to instruct illumination of the headlights (step S21; YES), the illumination state setting unit 20 of the controller 10 supplies a control signal to the low beam units 31L, 31R of the headlights 11L, 11R to illuminate the low beams. As a result, the low beams are illuminated ahead of the vehicle (step S22). Note that the illumination state setting unit 20 also supplies an appropriate control signal to the high beam units 33L, 33R.

[0063] Furthermore, if the road surface condition estimation unit 21 estimates that there is at least one of rainfall around the vehicle and a wet road surface on which the vehicle is traveling, and that a water film has formed on the road surface (step S23; YES), and there is no oncoming vehicle (step S24; NO), the illumination state setting unit 20 supplies a control signal to the additional low beam units 32L and 32R of the headlights 11L and 11R to cause them to emit additional low beams. This causes the additional low beams to be emitted in front of the vehicle (step S26). Here, the additional low beams are emitted within a preset fixed illumination range within the illumination range of the additional low beams (see, for example, FIGS. 5A and 5B). Then, the process returns to step S11.

[0064] Also, if there is an oncoming vehicle (step S24; YES) and the oncoming vehicle is not located directly in front of the host vehicle (step S25; YES), the illumination state setting unit 20 also supplies a control signal to the additional low beam units 32L, 32R of the headlights 11L, 11R to cause them to emit additional low beams. As a result, the additional low beams are emitted in front of the host vehicle (step S26). Then, the process returns to step S21.

[0065] The determination of the presence or absence and position of an oncoming vehicle in steps S24 and S25 can be made based on either or both of the detection results of the camera 15 and the millimeter wave radar 16.

[0066] On the other hand, if it is estimated in step S23 that there is no rainfall around the host vehicle, or that the road surface on which the host vehicle is traveling is not wet and no water film has formed on the road surface due to wetness (step S23; NO), the illumination state setting unit 20 supplies a control signal to the additional low beam units 32L, 32R of each headlamp 11L, 11R to turn off the additional low beams. In other words, the illumination state setting unit 20 does not perform control to relatively increase the illuminance in a partial range. As a result, the additional low beams in front of the host vehicle are turned off (step S27). Then, the process returns to step S21.

[0067] Furthermore, if an oncoming vehicle is present (step S24; YES) and the oncoming vehicle is located directly in front of the host vehicle (step S25: YES), the illumination state setting unit 20 supplies a control signal to the additional low beam units 32L, 32R of the headlights 11L, 11R to turn off the additional low beams. That is, the illumination state setting unit 20 does not perform control to relatively increase the illuminance in a partial range. As a result, the additional low beams in front of the host vehicle are turned off (step S27). Then, the process returns to step S21.

[0068] On the other hand, if the headlight illumination stop command is issued in step S21 (step S21; NO), the illumination state setting unit 20 of the controller 10 supplies a control signal to turn off all units, such as the low beam units 31L and 31R of the headlights 11L and 11R. As a result, all units of the headlights 11L and 11R are turned off (step S28). Then, the process returns to step S21.

[0069] 13 is a flowchart showing another operational procedure of the vehicle headlamp system 1A of the second embodiment. In the second embodiment, a case where an additional low beam with a preset fixed illumination range is used will also be described. Note that the order of the processes shown here can be changed as long as no contradictions or inconsistencies occur in the results of the information processing, and other processes not explicitly shown here can also be added.

[0070] When the driver operates the lamp switch 14 of the vehicle to instruct illumination of the headlights (step S31; YES), the illumination state setting unit 20 of the controller 10 supplies a control signal to the low beam units 31L, 31R of the headlights 11L, 11R to illuminate the low beams. As a result, the low beams are illuminated ahead of the vehicle (step S32). Note that the illumination state setting unit 20 also supplies an appropriate control signal to the high beam units 33L, 33R.

[0071] Furthermore, when the road surface condition estimation unit 21 estimates that there is at least one of rainfall around the vehicle and a wet road on which the vehicle is traveling, and that a water film has formed on the road surface (step S33; YES), and there is no left-hand curve ahead of the vehicle (step S34; NO), the illumination state setting unit 20 supplies a control signal to the additional low beam units 32L, 32R of the headlights 11L, 11R to emit additional low beams. As a result, the additional low beams are emitted ahead of the vehicle (step S35).

[0072] Here, the supplemental low beam is irradiated within a preset fixed irradiation range within the range where the supplemental low beam can be irradiated (see Fig. 5(A) and Fig. 5(B) as an example). Whether or not there is a left curve in step S34 can be determined based on road information (road data) obtained from a navigation system (not shown) or the like. The presence or absence of a left curve may also be detected by camera 15. After step S35 is executed, the process returns to step S31.

[0073] Furthermore, in the above-mentioned step S33, if it is estimated that there is no rainfall around the host vehicle, or that the road surface on which the host vehicle is traveling is not wet and no water film has formed on the road surface (step S33; NO), the illumination state setting unit 20 supplies a control signal to the additional low beam units 32L, 32R of each headlamp 11L, 11R to turn off the additional low beams. In other words, the illumination state setting unit 20 does not perform control to relatively increase the illuminance in a partial range. As a result, the additional low beams in front of the host vehicle are turned off (step S36). Then, the process returns to step S31.

[0074] Furthermore, if there is a left-hand curve ahead of the vehicle (step S34; YES), the illumination state setting unit 20 supplies a control signal to the additional low beam units 32L, 32R of the headlights 11L, 11R to turn off the additional low beams. That is, the illumination state setting unit 20 does not perform control to relatively increase the illuminance in a partial range. As a result, the additional low beams ahead of the vehicle are turned off (step S36). Then, the process returns to step S31.

[0075] On the other hand, if the headlight illumination stop command is issued in step S31 (step S31; NO), the illumination state setting unit 20 of the controller 10 supplies a control signal to turn off all units, such as the low beam units 31L and 31R, of the headlights 11L and 11R. As a result, all units of the headlights 11L and 11R are turned off (step S37). Then, the process returns to step S31.

[0076] The second embodiment as described above also provides a technology that can ensure brightness on the near side ahead of the vehicle and prevent glare to other vehicles during rainy weather, etc. Furthermore, when there is a left-hand curve ahead of the vehicle and the oncoming vehicle is positioned in front of the vehicle, the additional low beam is turned off, thereby preventing glare to oncoming vehicles.

[0077] As a modification of the second embodiment, the additional low beam may be controlled to be turned off when a leading vehicle is present within a predetermined distance ahead of the host vehicle.

[0078] (Third embodiment) In the first and second embodiments described above, it is assumed that supplemental low beams are used with a fixed illumination range set in advance within the range in which the supplemental low beams can be irradiated. However, it is also preferable to dynamically estimate the eye position of the driver of an oncoming vehicle and variably set the illumination range of the supplemental low beams based on the estimation results. A vehicle headlamp system that performs such control will be described in detail below. Explanations of matters common to the first and second embodiments will be omitted where appropriate.

[0079] 14 is a block diagram showing the configuration of a vehicle headlamp system according to the third embodiment. The basic configuration of the illustrated vehicle headlamp system 1B is the same as that of the vehicle headlamp system 1A according to the second embodiment, but differs in that the controller 10 has, as its functional block, an eye position estimation unit 22 that estimates the eye position of the driver of an oncoming vehicle (hereinafter simply referred to as "eye position") in real time, and that the illumination range of the supplemental low beam is variably set by the illumination state setting unit 20 based on the estimation result by the eye position estimation unit 22. The main differences will be described below.

[0080] The eye position estimation unit 22 estimates the eye position based on the relative distance (distance from the vehicle) and vehicle type (e.g., sedan, SUV, truck, etc.) of the oncoming vehicle detected by the camera 15 and / or millimeter-wave radar 16. The eye position is estimated at regular intervals (e.g., every few tens of milliseconds). The eye position can be estimated by referring to a data table stored in a memory (not shown) that indicates the vertical position (i.e., height) and horizontal position relative to the vehicle position for each vehicle type and relative distance. Such a data table can be created using publicly available information. The relative distance to the oncoming vehicle is also obtained by the camera 15 or millimeter-wave radar 16.

[0081] Fig. 15(A) is an overhead view showing the relative positional relationship between the host vehicle and an oncoming vehicle. Fig. 15(B) and Fig. 15(C) are side views showing the relative positional relationship between the host vehicle and an oncoming vehicle. As shown in each figure, the installation position of the left headlamp 11L of the host vehicle 100, more specifically the light emission center of the additional low beam, is set as the origin (0,0,0), and the eye position of the driver of the oncoming vehicle 101 is set as (x,y,z). The x-axis corresponds to the longitudinal direction of the host vehicle 100, the y-axis corresponds to the lateral direction of the host vehicle 100, and the z-axis corresponds to the height direction (vertical direction) of the host vehicle 100.

[0082] If the eye position (x, y, z) of the oncoming vehicle 101 is expressed in terms of the left-right angle θ1 [deg] and the up-down angle θ2 [deg] relative to the origin (0, 0, 0), which is the light emission center of the additional low beam, it can be expressed by the following equations.

number

[0083] 16(A) is a diagram showing the definition of the left-right angle θ1. A plane (t1-y plane) is created by a line t1 connecting the projected eye position (x,0,z) obtained by projecting the eye position (x,y,z) onto the xz plane and the origin (0,0,0), and the y-axis. On this t1-y plane, the angle formed by the line t1 connecting the origin (0,0,0) and the eye position (x,y,z) and the line t1 is defined as θ1.

[0084] Figure 16(B) is a diagram showing the definition of the vertical angle θ2. A plane (t2-z plane) is created by a line t2 connecting the projected eye position (x,y,z) obtained by projecting the eye position (x,y,z) onto the xy plane to the origin (0,0,0) and the z axis, and the line t2. On this t2-z plane, the angle formed by the line connecting the origin (0,0,0) and the eye position (x,y,z) and the line t2 is defined as θ2.

[0085] FIG. 17 is a diagram illustrating the correspondence relationship between the left-right angle θ1 and the up-down angle θ2 on the screen. The distance between the light-emitting center p of the supplemental low beam and the screen SC is, for example, 15 m to 220 m. At the intersection point between the optical axis a of the supplemental low beam and the screen SC, both the horizontal direction H and the vertical direction V are assumed to be 0. That is, at the intersection point, the up-down angle θ1 and the left-right angle θ2 are assumed to be 0 (UD=LR=0). The point on the screen identified by the left-right angle θ1 and the up-down angle θ2 corresponds to the eye position (x, y, z). The transition of this eye position is shown on the screen as a line segment g1 in FIG. 18(A). By using the up-down angle θ1 and the left-right angle θ2, which can be calculated in real time in this way, direct light directed at the driver of an oncoming vehicle can be controlled taking into account the depth.

[0086] Next, as shown in Figure 15(C), assuming that the additional low beam is specularly reflected (regularly reflected) on the road surface, the road surface coordinates of the reflection position of the reflected light incident on the eye position of the oncoming vehicle 101 are (x1, y1, z1).

[0087] If the position of the road surface coordinates (x1, y1, z1) based on the origin (0, 0, 0), which is the light emitting center of the additional low beam, is expressed as the left-right angle θ3 [deg] and the up-down angle θ4 [deg], then it can be expressed by the following equations.

number

[0088] 19(A) is a diagram showing the definition of the left-right angle θ3. A plane (t3-y plane) is created by a line t3 connecting the origin (0,0,0) and the projected road surface coordinates (x1,0,z1) obtained by projecting the road surface coordinates (x1,y1,z1) onto the xz plane, and the y-axis. On this t3-y plane, the angle formed by the line connecting the origin (0,0,0) and the road surface coordinates (x1,y1,z1) and the line t3 is defined as θ3.

[0089] 19(B) is a diagram showing the definition of the vertical angle θ4. A plane (t4-y plane) is created by a line t4 connecting the origin (0,0,0) and the projected road surface coordinates (x1,y1,z1) obtained by projecting the road surface coordinates (x1,y1,z1) onto the xy plane, and the z axis. On this t4-z plane, the angle formed by the line connecting the origin (0,0,0) and the road surface coordinates (x1,y1,z1) and the line t4 is defined as θ4.

[0090] The transition of eye position determined by the horizontal angle θ3 and the vertical angle θ4 in this way can be displayed on a screen as shown by line segment g2 in Figure 18(B). Using the vertical angle θ3 and horizontal angle θ4 that can be calculated in this way makes it possible to dynamically prevent glare caused by reflected light from reaching the driver of an oncoming vehicle. Specifically, within the illumination range of the supplemental low beam, road surface coordinates determined based on the vertical angle θ3 and horizontal angle θ4 are calculated in real time, and control is performed so that the illuminance in the shaded area 80 (see Figure 18(B)) that includes the position of the road surface coordinates does not increase relatively. This makes it possible to ensure a larger illumination range d of the supplemental low beam within the illumination range while also preventing glare from reaching oncoming vehicles.

[0091] Although detailed explanation will be omitted to avoid redundancy, the shading range in which the illuminance should be relatively reduced in relation to the right headlight 11R can be determined using logic similar to that in relation to the left headlight 11L described above.

[0092] 20 is a flowchart showing the operation procedure of a vehicle headlamp system 1B according to a third embodiment. In the third embodiment, a case will be described in which a supplemental low beam is used with a preset fixed illumination range d (see FIG. 18(B)), and a shaded area 80 (see FIG. 18(B)) is dynamically set within the illumination range of this supplemental low beam so that the illuminance of the shaded area 80 is not relatively increased. Note that the order of the processes shown here can be changed as long as no contradiction or inconsistency occurs in the results of the information processing, and other processes not explicitly shown here can also be added.

[0093] When the driver operates the lamp switch 14 of the vehicle to instruct illumination of the headlights (step S41; YES), the illumination state setting unit 20 of the controller 10 supplies a control signal to the low beam units 31L, 31R of the headlights 11L, 11R to illuminate the low beams. As a result, the low beams are illuminated ahead of the vehicle (step S42). Note that the illumination state setting unit 20 also supplies an appropriate control signal to the high beam units 33L, 33R.

[0094] Furthermore, if the road surface condition estimation unit 21 estimates that there is at least one of rainfall around the vehicle and a wet road surface on which the vehicle is traveling, and that a water film has formed on the road surface (step S43; YES), the illumination state setting unit 20 supplies a control signal to the additional low beam units 32L and 32R of the headlights 11L and 11R to cause them to emit additional low beams. This causes the additional low beams to be emitted in front of the vehicle (step S44). Here, the additional low beams are emitted within a preset fixed illumination range d (see FIG. 18(B) for an example) within the illumination range of the additional low beams.

[0095] If the presence of an oncoming vehicle is detected by either or both of the camera 15 and the millimeter wave radar 16 (step S45; YES), the eye position estimation unit 22 estimates the eye position of the driver of the oncoming vehicle (step S46). On the other hand, if the presence of an oncoming vehicle is not detected (step S45; NO), the process returns to step S41.

[0096] The light distribution state setting unit 20 calculates road surface coordinates (x1, y1, z1) based on the eye position (x, y, z) estimated by the eye position estimation unit 22 (step S47), and sets the shading area 80 based on these road surface coordinates (step S48). The shading area 80 may be set, for example, as a circle of a predetermined radius centered on the road surface coordinates, or as a square or rectangle with the road surface coordinates as its center of gravity, or may be set to any other shape. The size (area) of the shading area 80 may be determined appropriately based on experiments, simulations (theoretical calculations), etc.

[0097] The illumination state setting unit 20 supplies a control signal to the additional low beam units 32L, 32R of the headlights 11L, 11R to cause them to emit an additional low beam that includes the shaded area 80. As a result, the additional low beam that includes the shaded area 80 (see FIG. 18(B) as an example) is emitted ahead of the vehicle (step S49). Then, the process returns to step S41.

[0098] The processes from step S41 onwards are repeated at predetermined intervals (for example, every few tens of milliseconds), whereby the light blocking range 80 is dynamically reset in response to changes over time in the position of the oncoming vehicle.

[0099] On the other hand, if the headlight illumination stop command is issued in step S41 (step S41; NO), the illumination state setting unit 20 of the controller 10 supplies a control signal to turn off all units, such as the low beam units 31L and 31R of the headlights 11L and 11R. As a result, all units of the headlights 11L and 11R are turned off (step S50). Then, the process returns to step S41.

[0100] Furthermore, if it is estimated that there is no rainfall around the host vehicle, or that the road surface on which the host vehicle is traveling is not wet and no water film is present on the road surface (step S43; NO), the illumination state setting unit 20 supplies a control signal to the additional low beam units 32L, 32R of each headlamp 11L, 11R to turn off the additional low beams. In other words, the illumination state setting unit 20 does not perform control to relatively increase the illuminance in a partial range. As a result, the additional low beams in front of the host vehicle are turned off (step S51). Then, the process returns to step S41.

[0101] The third embodiment as described above also provides a technology that can ensure brightness on the near side ahead of the vehicle and prevent glare to other vehicles during rainy weather, etc. Furthermore, since the shading range 80 is set in real time in the illumination range d of the supplemental low beam in accordance with changes over time in the position of oncoming vehicles, it is possible to ensure a wider illumination range d of the supplemental low beam while preventing glare to oncoming vehicles.

[0102] (Modified embodiment) The present disclosure is not limited to the content of the above-described embodiments, and various modifications can be made within the scope of the gist of the present disclosure. For example, in the above-described embodiments, it is assumed that the host vehicle is required by law to drive on the left side of the road and the oncoming lane is located on the right side of the host vehicle. However, the content of the present disclosure can also be applied to a case where the host vehicle drives on the right side of the road and the oncoming lane is located on the left side of the host vehicle. In this case, it is sufficient to interchange the left-right positional relationship and the positional relationship between the leading vehicle and the oncoming vehicle in the above-described embodiments (see the following supplementary notes).

[0103] The present disclosure has the following additional features. (Appendix 1) a sensor configured to detect at least one of rainfall and a wet road condition around the vehicle; a controller connected to each of the pair of headlights and the sensor and configured to be able to control the operation of the pair of headlights; Including, the pair of headlights are configured to be able to irradiate at least a low beam ahead of the vehicle and to change the illuminance of a part of an illumination range of the low beam, the controller controls the illumination state of the pair of headlights so as to relatively increase the illuminance of the partial range when it is estimated that a water film is generated based on the detection result of the sensor. Vehicle headlight system. (Appendix 2) The partial range is set so as to be included in an illumination range defined between a right boundary set based on a first road surface coordinate, which is a reflection position of light from the pair of headlights on the road surface when the light is specularly reflected by the road surface and incident on a first position of a first forward vehicle assumed to be located on the right side of the host vehicle, and a left boundary set based on a second road surface coordinate, which is a reflection position of light from the pair of headlights on the road surface when the light is specularly reflected by the road surface and incident on a second position of a second forward vehicle assumed to be located on the left side of the host vehicle. 10. The vehicle headlamp system of claim 1. (Appendix 3) The partial range is set as a fixed range. 3. A vehicle headlamp system according to claim 1 or 2. (Appendix 4) The partial range is set to a range smaller than the irradiatable range. Attachment 1 - 3: A vehicle headlamp system according to any one of attachments 1 to 3. (Appendix 5) the right boundary is determined based on a first line segment as a collection of the first road surface coordinates obtained by setting a relative distance between the first forward vehicle and the host vehicle within a predetermined distance, the left boundary is determined based on a second line segment as a collection of the second road surface coordinates obtained by setting the relative distance between the second forward vehicle and the host vehicle within a predetermined distance, 6. A vehicle headlamp system according to any one of appendices 1 to 5. (Appendix 6) The first front vehicle is an oncoming vehicle, and the second front vehicle is a leading vehicle. 6. A vehicle headlamp system according to any one of appendices 1 to 5. (Appendix 7) the first position is a position estimated as the eye position of the driver of the oncoming vehicle, The second position is a position estimated as a mirror position of the preceding vehicle. 7. A vehicle headlamp system as described in appendix 6. (Appendix 8) The controller does not perform control to relatively increase the illuminance of the partial range when the road on which the vehicle is traveling is a left-hand curve, even if the generation of the water film is estimated. 7. A vehicle headlamp system as described in appendix 6. (Appendix 98) the controller does not perform control to relatively increase the illuminance of the partial range when an oncoming vehicle is present directly ahead of the host vehicle, even when the generation of the water film is estimated. A vehicle headlamp system according to any one of appendices 1 to 8. (Appendix 10) The pair of headlights includes a first unit capable of emitting the low beam and a second unit capable of emitting light to the partial range. A vehicle headlamp system according to any one of appendices 1 to 9. (Appendix 11) The pair of headlights are configured to include a third unit that is capable of emitting the low beam and is configured to be able to increase or decrease the illuminance of the partial range. A vehicle headlamp system according to any one of appendices 1 to 9. (Appendix 12) a pair of headlights disposed at the front of the host vehicle; a first sensor configured to detect at least one of rainfall and a road surface wetness around the vehicle; a second sensor configured to detect the position, vehicle type, and relative distance from the host vehicle of another vehicle present at least on the front right or front left of the host vehicle; a controller connected to each of the pair of headlights, the first sensor, and the second sensor, and configured to be able to control the operation of the pair of headlights; Including, the pair of headlights are configured to be able to irradiate at least a low beam ahead of the vehicle and to change the illuminance of a part of an illumination range of the low beam, The controller When it is estimated that a water film is generated based on the detection result of the first sensor, the illumination state of the pair of headlights is controlled so as to relatively increase the illuminance of the partial range; and an eye position of the driver of the other vehicle is estimated based on the position, vehicle type, and relative distance of the other vehicle detected by the second sensor; and, according to the estimated eye position, a first road surface coordinate is calculated in real time, which is a reflection position of the light from the pair of headlights on the road surface when the light is specularly reflected from the road surface and incident on a first position of the other vehicle; a light-blocking range is set based on the first road surface coordinate calculated in real time; and the illumination state of the pair of headlights is controlled so as not to relatively increase the illuminance in the light-blocking range. Vehicle headlight system. [Explanation of symbols]

[0104] 1: Vehicle headlamp system, 10: Controller, 11L: Left headlamp, 11R: Right headlamp, 12: Rainfall sensor, 13: Road surface sensor, 14: Lamp switch, 20: Illumination state setting unit, 21: Road surface condition estimation unit, 31L, 31R: Low beam unit, 32L, 32R: Additional low beam unit, 33L, 33R: High beam unit

Claims

1. a pair of headlights disposed at the front of the host vehicle; a sensor configured to detect at least one of rainfall and a wet road condition around the vehicle; a controller connected to each of the pair of headlights and the sensor and configured to be able to control the operation of the pair of headlights; Including, the pair of headlights are configured to be able to irradiate at least a low beam ahead of the vehicle and to change the illuminance of a part of an illumination range of the low beam, the controller controls the illumination state of the pair of headlights so as to relatively increase the illuminance of the partial range when it is estimated that a water film is generated based on the detection result of the sensor. Vehicle headlight system.

2. The partial range is set so as to be included in an illumination range defined between a right boundary set based on a first road surface coordinate, which is the reflection position of light from the pair of headlights on the road surface when the light is specularly reflected by the road surface and incident on a first position of a first forward vehicle assumed to be located on the right side of the vehicle, and a left boundary set based on a second road surface coordinate, which is the reflection position of light from the pair of headlights on the road surface when the light is specularly reflected by the road surface and incident on a second position of a second forward vehicle assumed to be located on the left side of the vehicle. The vehicle headlamp system according to claim 1 .

3. The partial range is set as a fixed range. The vehicle headlamp system according to claim 1 .

4. The partial range is set to a range smaller than the irradiatable range. The vehicle headlamp system according to claim 1 .

5. the right boundary is determined based on a first line segment as a collection of the first road surface coordinates obtained by setting a relative distance between the first forward vehicle and the host vehicle within a predetermined distance, the left boundary is determined based on a second line segment as a collection of the second road surface coordinates obtained by setting a relative distance between the second forward vehicle and the host vehicle within a predetermined distance, The vehicle headlamp system according to claim 1 .

6. The first front vehicle is an oncoming vehicle, and the second front vehicle is a leading vehicle. The vehicle headlamp system according to claim 1 .

7. the first position is a position estimated as the position of the eyes of the driver of the oncoming vehicle, the second position is a position estimated as a mirror position of the preceding vehicle; 7. The vehicle headlamp system according to claim 6.

8. The controller does not perform control to relatively increase the illuminance of the partial range when the road on which the vehicle is traveling is a left-hand curve, even if the generation of the water film is estimated.

7. The vehicle headlamp system according to claim 6.

9. the controller does not perform control to relatively increase the illuminance of the partial range when an oncoming vehicle is present directly ahead of the host vehicle, even when the generation of the water film is estimated. The vehicle headlamp system according to claim 1 .

10. The pair of headlights includes a first unit capable of emitting the low beam and a second unit capable of emitting light to the partial range. The vehicle headlamp system according to claim 1 .

11. The pair of headlights are configured to include a third unit that is capable of emitting the low beam and is configured to be able to increase or decrease the illuminance of the partial range. The vehicle headlamp system according to claim 1 .

12. a pair of headlights disposed at the front of the host vehicle; a first sensor configured to detect at least one of rainfall and a road surface wetness around the vehicle; a second sensor configured to detect the position, vehicle type, and relative distance from the host vehicle of another vehicle present at least on the front right or front left of the host vehicle; a controller connected to each of the pair of headlights, the first sensor, and the second sensor, and configured to be able to control the operation of the pair of headlights; Including, the pair of headlights are configured to be able to irradiate at least a low beam ahead of the vehicle and to change the illuminance of a part of an illumination range of the low beam, The controller When it is estimated that a water film is generated based on the detection result of the first sensor, the illumination state of the pair of headlights is controlled so as to relatively increase the illuminance of the partial range; and an eye position of the driver of the other vehicle is estimated based on the position, vehicle type, and relative distance of the other vehicle detected by the second sensor; and, in accordance with the estimated eye position, first road surface coordinates are calculated in real time, which are the reflection positions of the light from the pair of headlights on the road surface when the light is specularly reflected from the road surface and incident on a first position of the other vehicle; a light-blocking range is set based on the first road surface coordinates calculated in real time; and the illumination state of the pair of headlights is controlled so as not to relatively increase the illuminance in the light-blocking range. Vehicle headlight system.

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