Headlamp control device, headlamp control method, and headlamp system

Abstract

The present invention further improves forward visibility in a host vehicle while reducing glare to a vehicle in front.　The present invention provides a headlamp control device in which a controller is configured to control a headlamp so as to emit a selective high beam, and to control the headlamp such that, when a vehicle in front is present on a first side, which is either a left side or a right side with respect to the host vehicle, a partial range within a low beam emission range is dimmed at a first dimming rate if it is estimated that the weather around the host vehicle is rainy, and is dimmed at a second dimming rate relatively smaller than the first dimming rate if it is estimated that the weather is not rainy, wherein: the low beam has an upper end in a position at or below the height of a horizontal line based on the position of the headlamp; the partial range is a range from the upper end to a position higher than the lower end of the low beam; and a high illumination intensity band is set to a range on the first side of a vertical line based on the position of the headlamp.

Description

Headlight control device, headlight control method, and headlight system

[0001] The present disclosure relates to a headlamp control device, a headlamp control method, and a headlamp system.

[0002] International Publication No. 2022 / 131044 (Patent Document 1) describes a vehicle lighting system that includes a low beam unit that is capable of forming a low beam light distribution pattern having a cutoff line and that is capable of independently adjusting the illuminance of multiple partial areas that are arranged below and along the cutoff line in the low beam light distribution pattern, and a light distribution control device that controls the low beam unit to form a first illuminance reduction section in a partial area among the multiple partial areas whose position in the vehicle width direction overlaps the position of a vehicle ahead in the vehicle width direction.

[0003] International Publication No. 2022 / 131044

[0004] One of the objectives of a specific aspect of the present disclosure is to provide a technology that can further improve forward visibility in a vehicle while reducing glare to a vehicle ahead.

[0005] [1] A headlamp control device according to one aspect of the present disclosure is a device for controlling the operation of a headlamp capable of emitting a low beam and a selective high beam, comprising: a controller connected to the headlamp; and a forward monitoring sensor connected to the controller and configured to detect a forward vehicle present in front of a host vehicle, wherein the controller is configured to: control the headlamp to emit the selective high beam including a dimming range according to the position of the forward vehicle detected by the forward monitoring sensor; and, when the forward vehicle is present on a first side, which is either the left or right side of the host vehicle, on the side of an oncoming lane, to control the headlamp to dim at least a partial range that partially overlaps with the low beam illumination range at a first dimming rate if the weather around the host vehicle is estimated to be rainy, and to dim at a second dimming rate relatively smaller than the first dimming rate if the weather is estimated not to be rainy; and, wherein light is irradiated onto the partial range in conjunction with irradiation of the high beam, and the low beam has an upper end at a position equal to or lower than the height of the horizon relative to the position of the headlamp, the partial range is a range from the upper end to a position higher than the lower end of the low beam, and at least a high illuminance band is set in the first range with respect to a vertical line based on the position of the headlamp.[2] A headlamp control method according to one aspect of the present disclosure is a method executed by a controller connected to the headlamp to control the operation of a headlamp capable of emitting a low beam and a selective high beam, the method comprising: controlling the headlamp to emit the selective high beam including a dimming range according to the position of a forward vehicle present ahead of the host vehicle; and controlling the headlamp to dim at least a partial range that partially overlaps with the low beam illumination range at a first dimming rate when the weather around the host vehicle is estimated to be rainy, and to dim at a second dimming rate relatively smaller than the first dimming rate when the weather is estimated not to be rainy, when the forward vehicle is present on a first side, that is, a oncoming lane, which is either to the left or right of the host vehicle; wherein light is irradiated onto the partial range in conjunction with irradiation of the high beam; and wherein the low beam has an upper end at a position equal to or lower than the height of the horizon based on the position of the headlamp; a headlamp control method for controlling a headlamp, the headlamp being capable of emitting a low beam and a selective high beam, the headlamp being controlled by the control device, and the partial range being a range from the upper end to a position higher than the lower end of the low beam, and at least a high illuminance band being set in the first range with respect to a vertical line based on the position of the headlamp.

[0006] In this specification, the concept of "dimming" includes reducing the brightness of the irradiated light to 0, that is, turning off the light.

[0007] According to the above configuration, it is possible to further improve forward visibility in the host vehicle while reducing glare to the vehicle ahead.

[0008] FIG. 1(A) is a diagram illustrating the configuration of a headlight system according to an embodiment. FIG. 1(B) is a diagram illustrating an example of a computer system. FIG. 2 is a schematic front view illustrating an example of the configuration of a headlight. FIG. 3(A) is a diagram illustrating specific examples of the illumination ranges of the low beam, high beam, and additional beam. FIGS. 3(B) and 3(C) are diagrams illustrating an extracted illumination range of the additional beam. FIG. 4 is a diagram illustrating an example of the positional relationship between a vehicle and an oncoming vehicle. FIG. 5 is a flowchart illustrating the operation procedure of the headlight system. FIG. 6(A) is a diagram illustrating a schematic example of illumination of each beam when an oncoming vehicle is present but it is not raining. FIG. 6(B) is a diagram illustrating a schematic example of illumination of each beam when an oncoming vehicle is present but it is raining. FIG. 6(C) is a diagram illustrating a schematic example of illumination of each beam when a leading vehicle is present.

[0009] 1A is a diagram showing the configuration of a headlamp system according to one embodiment. The illustrated headlamp system includes a controller (control device) 10, a forward monitoring sensor 11, and a pair of headlamp 13L, 13R. This headlamp system is installed on a vehicle and is used to illuminate the area ahead of the vehicle. In this embodiment, the controller 10 and the forward monitoring sensor 11 are assumed to be installed on the vehicle side, but one or both of the controller 10 and the forward monitoring sensor 11 may be installed inside the housing of the headlamp 13L and / or the headlamp 13R.

[0010] The controller 10 is connected to the forward monitoring sensor 11 and each of the headlights 13L, 13R, and controls various operations of the headlight system. The controller 10 is also configured to detect the operating states of a wiper switch 12 and a lamp switch 14 provided on the vehicle. For example, the controller 10 detects the operating state of the lamp switch 14 provided on the driver's seat of the vehicle, and transmits a control signal corresponding to the detected state to each of the headlights 13L, 13R.

[0011] The forward monitoring sensor 11 is connected to the controller 10 and detects the position, size, type, etc. of an object present in front of the vehicle. Examples of objects to be detected and their types include vehicles ahead (leading vehicles, oncoming vehicles), pedestrians, bicycles, road signs, obstacles, etc. As an example, the forward monitoring sensor 11 can be configured using a camera that captures an image of the space ahead of the vehicle and an information processing device such as an image processor that determines the position, etc. of an object by performing image processing using the image captured by the camera.

[0012] The type of vehicle ahead, i.e., whether it is a leading vehicle or an oncoming vehicle, can be identified based on the color of its lamp. For example, if a pair of white or similar light spots is detected, it is an oncoming vehicle, and if a pair of red or similar light spots is detected, it is a leading vehicle.

[0013] The forward monitoring sensor 11 may be, for example, an optical distance measuring sensor such as LiDAR, or a radar or ultrasonic sensor, or these may be used in combination with the image processing described above.

[0014] The headlights 13L, 13R are capable of emitting a low beam and a selective high beam to the space ahead of the vehicle, and include a low beam unit 30, an ADB unit 31, and an additional beam unit 32. As shown in the schematic front view of FIG. 2, each headlight 13L, 13R has, for example, an integrated low beam unit 30 and an ADB unit 31, and a separate additional beam unit 32, which are arranged adjacent to each other in the vehicle width direction. Note that each unit may be configured as a separate unit, or all units may be configured as an integrated unit. In other words, there are no particular limitations on the configuration of each unit.

[0015] Each low beam unit 30 is configured to emit a low beam (low-beam) into the space ahead of the vehicle based on a control signal supplied from the control signal generating unit 21 of the controller 10. The low beam unit 30 of the headlight 13L is installed on the front left side of the vehicle, and the low beam unit 30 of the headlight 13R is installed on the front right side of the vehicle. The low beam is formed by combining the light emitted from each low beam unit 30 toward the front of the vehicle.

[0016] Each ADB unit 31 is configured to emit a high beam into the space ahead of the vehicle based on a control signal supplied from the control signal generating unit 21 of the controller 10. The ADB unit 31 of the headlight 13L is installed on the front left side of the vehicle, and the ADB unit 31 of the headlight 13R is installed on the front right side of the vehicle. The high beam is formed when the light emitted by each ADB unit 31 overlaps in front of the vehicle. Furthermore, each ADB unit 31 is an adjustable light distribution unit, and when an object such as a preceding vehicle is present, a dimming range is set within the high beam illumination range according to the position of the object, thereby forming a selective high beam (adaptive driving beam).

[0017] Each ADB unit 31 may be, for example, an ADB unit configured to include a plurality of semiconductor light-emitting elements arranged in two directions and a lens that collects the light emitted from these light-emitting elements. Also, various types of known ADB units may be used, such as an ADB unit that uses a liquid crystal element to control the dimming range and light irradiation range, an ADB unit that uses an optical deflector to scan the light emitted from a laser element and controls the dimming range and light irradiation range by turning the laser element on and off at high speed, or an ADB unit that uses multiple shielding plates selectively to block part of the light emitted from the light source to control the dimming range and light irradiation range.

[0018] Each additional beam unit 32 is configured to be able to irradiate a partial area included in the low beam irradiation area with an additional beam based on a control signal supplied from the control signal generating unit 21 of the controller 10. Specific examples of partial areas irradiated with an additional beam will be described later.

[0019] The functions of the controller 10 will be described using functional blocks to make it easier to understand. As shown in Fig. 1, the controller 10 includes a light distribution pattern setting unit (light distribution pattern setting function) 20 and a control signal generating unit (control signal generating function) 21.

[0020] The light distribution pattern setting unit 20 sets the light reduction range (or light blocking range) and the light irradiation range in the ADB function of each ADB unit 31, depending on the position of a forward vehicle (a preceding vehicle or an oncoming vehicle) detected by the forward monitoring sensor 11. In addition, the light distribution pattern setting unit 20 variably controls the brightness of the additional beams from each additional beam unit 32.

[0021] The control signal generating unit 21 generates a control signal for causing each ADB unit 31 to form irradiation light according to the light distribution pattern set by the light distribution pattern setting unit 20, and supplies the control signal to each ADB unit 31. The control signal generating unit 21 also generates a control signal for causing each additional beam unit 32 to form irradiation light according to the brightness of the additional beam set by the light distribution pattern setting unit 20, and supplies the control signal to each additional beam unit 32. The control signal generating unit 21 also generates a control signal for causing each low beam unit 30 to emit a low beam according to the operating state of a lamp switch of the host vehicle, and supplies the control signal to each low beam unit 30.

[0022] In addition, if the vehicle is equipped with a function to automatically turn on and off the headlights 13L, 13R depending on the illuminance of the surrounding environment, the function may start lighting up each low beam unit 30, etc.

[0023] 1B is a diagram illustrating an example of a computer system. The illustrated computer system can be configured using a computer system including a processor (CPU: Central Processing Unit) 201, a ROM (Read Only Memory) 202, a RAM (Random Access Memory) 203, a storage device 204 such as a flash memory, an input / output interface 205, and the like. In this computer system, a program 206 stored in advance in the storage device 204 is read and executed by the processor, thereby enabling the computer system to perform various functions. The above-described controller 10 can be realized, for example, using such a computer system.

[0024] Figure 3(A) is a diagram showing specific examples of the illumination ranges of the low beam, high beam, and additional beam. Figures 3(B) and 3(C) are diagrams showing an extracted illumination range of the additional beam. These diagrams show the front view shapes of each beam on a virtual vertical screen assumed at a predetermined position ahead of the vehicle (e.g., 25 m ahead). In Figures 3(A) to 3(C), the horizontal line H and the vertical line V are based on the installation positions of the headlights 13L and 13R, respectively.

[0025] The low beam 50 is irradiated light that is formed with a relatively wide width below the cutoff line CL. In this embodiment, the cutoff line CL corresponds to the upper end of the low beam 50, i.e., the boundary line where the illuminance of the low beam 50 on a virtual vertical screen becomes equal to or less than a predetermined value. The cutoff line CL includes a first portion located to the right of the vertical line V in the drawing and extending in a substantially horizontal direction so as to substantially overlap with the horizontal line H, a second portion located to the left of the vertical line V in the drawing and extending in a substantially horizontal direction below the first portion, and a third portion connecting the ends of the first and second portions and extending obliquely so as to overlap with the vertical line V.

[0026] The high beam 51 is a beam of light that is formed mainly above the horizon H and has a narrower width than the low beam 50. In this embodiment, the high beam 51 includes a portion above the horizon H and a portion below the horizon H. The portion of the high beam 51 below the horizon H partially overlaps with the low beam 50 and the additional beams 52a and 52b. The illumination range of the high beam 51 is partially dimmed depending on the position of the vehicle ahead (see dimming range 53 in FIG. 6A etc. described later).

[0027] The additional beams 52a and 52b are irradiated light beams that are formed in a range that is shorter in both width (horizontal length) and height (vertical length) than the low beam 50. In this embodiment, the upper ends of the additional beams 52a and 52b are each substantially aligned with the horizontal line H, and the lower ends are positioned higher in the drawing than the lower end of the low beam 50, and are formed with a width narrower than that of the low beam 50.

[0028] 3B, the high-illuminance band 55a of the additional beam 52a is a portion of the additional beam 52a that is relatively long in the vertical direction (height), and is located to the right of the vertical line V in the drawing. The low-illuminance band 55b of the additional beam 52a is a portion of the additional beam 52a that is relatively short in the vertical direction (height), and most of it is located to the left of the vertical line V in the drawing. The high-illuminance band 55a is a portion with relatively higher illuminance than the low-illuminance band 55b.

[0029] 3C, the high illuminance band 56a of the additional beam 52b is a portion of the additional beam 52b that is relatively long in the vertical direction (height), and is located to the left of the vertical line V in the drawing. The low illuminance band 56b of the additional beam 52b is a portion of the additional beam 52b that is relatively short in the vertical direction (height), and most of it is located to the right of the vertical line V in the drawing. The high illuminance band 56a is a portion with relatively higher illuminance than the low illuminance band 56b.

[0030] In this embodiment, there is no gap between the additional beam 52a and the vertical line V, and between the additional beam 52b and the vertical line V, and each extends to the other. However, the range of each additional beam 52a, 52b may be set so that there is no gap between each of the additional beams 52a, 52b and the vertical line V. This indicates that there are no particular restrictions on the shape of each of the additional beams 52a, 52b as long as a high-intensity band, which is a relatively bright range (e.g., the brightest range) within each range of the additional beams 52a, 52b, is positioned in a specific position. It is preferable to set the height of each of the additional beams 52a, 52b to, for example, one-third or less of the height of the low beam 50. This makes it possible to further reduce the range of the additional beams 52a, 52b even when dimming them, thereby minimizing the reduction in forward visibility.

[0031] In this embodiment, the low beam 50 is supplemented by the additional beam 52a on the right side, resulting in illumination light with an illuminance distribution equivalent to that of a typical low beam. Furthermore, by dimming (or turning off) the additional beam 52a, a partial range of the low beam (the range illuminated by the additional beam 52a) is dimmed. Meanwhile, the additional beam 52b on the left side is illuminated (turned on) in conjunction with the illumination (turned on) of the high beam 51, and is turned off in conjunction with the illumination (turned off) of the high beam 51.

[0032] FIG. 4 is a diagram schematically illustrating an example of the positional relationship between a host vehicle and an oncoming vehicle. As illustrated, in this embodiment, it is assumed that traffic regulations stipulate that an oncoming vehicle 110 travels on the left side of the host vehicle 100. That is, in this embodiment, the left side corresponds to the "first side" of the oncoming lane, and the right side corresponds to the "second side" of the host vehicle's lane. Note that, in a case where traffic regulations stipulate that an oncoming vehicle travels on the right side of the host vehicle, low beam 50, high beam 51, and additional beams 52a and 52b having shapes inverted from those shown in FIG. 3 may be used. In this case, the right side corresponds to the "first side" of the oncoming lane, and the left side corresponds to the "second side" of the host vehicle's lane.

[0033] 5 is a flowchart showing the operation procedure of the headlamp system. 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.

[0034] When the lamp switch 14 is on, i.e., in a state instructing the operation of the headlights 13L, 13R (step S11; YES), and in a state instructing the irradiation of selective high beam (ADB) (step S12; YES), the light distribution pattern setting unit 20 of the controller 10 instructs the control signal generating unit 21 to emit a low beam and an additional beam. In response to this instruction, the control signal generating unit 21 supplies control signals to each low beam unit 30 and each additional beam unit 32, thereby emitting a low beam and an additional beam.

[0035] If the lamp switch 14 is not on (step S11; NO), or if the state is not one in which selective high beam irradiation is instructed (step S12; NO), the process returns to step S11.

[0036] The light distribution pattern setting unit 20 also instructs the control signal generating unit 21 to emit a selective high beam using a light distribution pattern having a dimming range that corresponds to the position of a forward vehicle (an oncoming vehicle or a preceding vehicle) detected by the forward monitoring sensor 11. In response to this instruction, the control signal generating unit 21 supplies a control signal to each ADB unit 31, causing the selective high beam to be emitted, and at the time the selective high beam is emitted, the additional beam 52b is emitted in conjunction with this (step S13). At this time, the emission of the additional beam 52a emitted from the additional beam unit 32 is stopped (or dimmed).

[0037] When the relative position of the forward vehicle output from the forward monitoring sensor 11 is on the left side of the vehicle (step S14; YES), and when it is estimated that it is raining around the vehicle based on the operating state of the wiper switch 12 (step S15; YES), the light distribution pattern setting unit 20 instructs the control signal generating unit 21 to dim the additional beam 52b located relatively to the left side at a first dimming rate.

[0038] In response to this instruction, the control signal generating unit 21 supplies a control signal to each additional beam unit 32, thereby dimming the additional beam 52b (step S16). When it is raining, the dimming rate (degree of dimming) is set to be greater than when it is not raining, which will be described later. For example, the additional beam 52b is dimmed so that its luminous intensity is reduced by 50% compared to normal times (when not dimmed). In other words, the first dimming rate can be set to, for example, 50%. When step S16 is completed, the process returns to step S11.

[0039] The forward vehicle in step S14 may be either an oncoming vehicle or a preceding vehicle. Regarding the relative position of the forward vehicle, for example, if half or more of the width of the forward vehicle in a front view is located to the left of the vertical line V, it can be determined that the forward vehicle is located to the left relative to the host vehicle. This is because the preceding vehicle functions not only when the lane is a straight road but also when the lane is a curved road, and the preceding vehicle is located in front of the host vehicle on a straight road, but is located to the left of the host vehicle on a left-curved road.

[0040] In addition, if the light distribution pattern setting unit 20 estimates that it is not raining around the vehicle based on the operating state of the wiper switch 12 (step S15; NO), it instructs the control signal generating unit 21 to dim the additional beam 52b located relatively to the left at the second dimming rate.

[0041] In response to this instruction, the control signal generator 21 supplies a control signal to each additional beam unit 32, thereby dimming the additional beam 52b (step S17). When it is not raining, the dimming rate is set to be smaller than when it is raining. For example, the additional beam 52b is dimmed so that its luminous intensity is reduced by 25% compared to normal conditions (when not dimmed). In other words, the second dimming rate can be set to, for example, 25%. When step S17 is completed, the process returns to step S11.

[0042] On the other hand, if the relative position of the forward vehicle is not on the left side (step S14; NO), the light distribution pattern setting unit 20 instructs the control signal generating unit 21 to maintain the current luminous intensity of the left additional beam 52b. In response to this instruction, the control signal generating unit 21 supplies a control signal to each additional beam unit 32, thereby maintaining the additional beam in its current state, i.e., in an undimmed state (step S18). When step S18 is completed, the process returns to step S11.

[0043] 6A is a diagram schematically illustrating an example of the illumination of each beam when an oncoming vehicle is present but it is not raining, showing the front view shapes of each beam on a virtual vertical screen similar to that described above. When an oncoming vehicle 110 is present relatively to the left of the vehicle, a dimming range 53 corresponding to the position of the oncoming vehicle 110 is provided within the illumination range of the high beam 51. In addition, the low beam 50 is illuminated, but the additional beam 52b is dimmed at a second dimming rate. This reduces the glare to the driver of the oncoming vehicle 110. In this case, since it is not raining, the second dimming rate of the additional beam 52b is set to a smaller value than when it is raining (for example, 25% as shown in the example).

[0044] 6(B) is a diagram schematically illustrating an example of the illumination of each beam when an oncoming vehicle is present and it is raining, showing the front view shapes of each beam on a virtual vertical screen similar to that described above. When an oncoming vehicle 110 is present relatively to the left of the vehicle, a dimming range 53 corresponding to the position of the oncoming vehicle 110 is provided within the illumination range of the selective high beam 51. In addition, the low beam 50 is illuminated, but the additional beam 52b is dimmed at a first dimming rate. This reduces glare for the driver of the oncoming vehicle 110. In this case, because it is raining, the first dimming rate of the additional beam 52b is set to a higher value than when it is not raining (for example, 50% as shown in the example).

[0045] 6A and 6B, an oncoming vehicle is shown as a vehicle ahead relatively to the left, but the vehicle ahead may also be a preceding vehicle. For example, this may be the case when there are two or more lanes in the direction of travel of the vehicle.

[0046] 6(C) is a diagram showing a schematic example of the illumination of each beam when a preceding vehicle is present. When a preceding vehicle 120 is present relatively to the right of the host vehicle, a dimming range 53 is provided within the illumination range of the high beam 51 according to the position of the preceding vehicle 120. In addition, the low beam 50 is illuminated, and the additional beam 52b is not dimmed, maintaining a predetermined illuminance. As a result, glare for the driver of the preceding vehicle 120 is reduced, and the additional beam 52b is illuminated below the horizon H without being dimmed until it is close to the horizon H, improving long-distance visibility for the driver of the host vehicle.

[0047] In other words, in the headlamp system of this embodiment, the scene in which the additional beam 52b, which is a portion of the beam that partially overlaps with the low beam, needs to be dimmed is limited to when the vehicle ahead is located relatively to the left of the vehicle, so the period during which the additional beam 52b does not need to be dimmed, in other words, the period during which the portion of the beam that partially overlaps with the low beam does not need to be dimmed, can be secured longer. Furthermore, because the dimming rate is greater in rainy weather than in non-rainy weather, glare caused by road surface reflection in rainy weather can be further reduced.

[0048] This will be explained using specific numerical examples. For example, assume that a vehicle ahead is located to the left of the vehicle, as shown in FIG. 6B above. As an example, assume that the vehicle ahead is 50 meters ahead and to the left. In this case, light traveling 2.2 degrees below the horizontal line H and 4 degrees to the left of the vertical line V is reflected by the road surface, which may cause glare to the vehicle ahead.

[0049] Considering the luminous intensity distribution on the virtual vertical screen described above, when an undimmed additional beam 52b is irradiated, the luminous intensity of light traveling under the above conditions, i.e., 2.2° downward from the horizontal line H and 4° left from the vertical line V, is, for example, 15,000 cd for the low beam 50 and 10,000 cd for the additional beam 52b, for a total of 25,000 cd. In contrast, when an additional beam 52b is irradiated with a dimming of, for example, about 50% compared to before dimming, the luminous intensity decreases from 25,000 cd to 20,000 cd, resulting in a 20% reduction in glare. Furthermore, when the additional beam 52b is dimmed by, for example, about 25% compared to before dimming, the luminous intensity decreases from 25,000 cd to 22,500 cd, resulting in a 10% reduction in glare.

[0050] According to the above-described embodiment, it is possible to further improve forward visibility in the host vehicle while reducing glare to the vehicle ahead.

[0051] The present disclosure is not limited to the above-described embodiment, and various modifications can be made within the scope of the gist of the present disclosure. For example, the above-described embodiment is based on the premise that an oncoming vehicle is traveling on the left side of the host vehicle (see FIG. 4 ). However, the relative relationship between the host vehicle and the oncoming vehicle may be reversed. That is, the technical concept of the present disclosure can also be applied to a case where an oncoming vehicle is traveling on the right side of the host vehicle. In this case, it is sufficient to use low beams, high beams, and additional beams with shapes that are inverted from those shown in FIG. 3 , as described above.

[0052] Furthermore, in the above embodiment, the additional beams 52a and 52b emitted from the additional beam unit 32 are superimposed and irradiated within the irradiation range of the low beam emitted from the low beam unit 30, but the additional beam unit 32 can be omitted by using a variable light distribution unit as the low beam unit 30. In this case, by selectively dimming a partial range corresponding to the additional beams 52a and 52b using the low beam unit 30, which is a variable light distribution unit, it is possible to irradiate the partial range with irradiation light corresponding to the dimmed additional beams 52a and 52b.

[0053] In the above embodiment, the weather is estimated based on the operating state of the wiper switch 12, but the method of estimating the weather is not limited to this. For example, the weather may be estimated using a detection signal from a sensor that can directly detect raindrops due to rain, such as a raindrop sensor, or the weather may be estimated based on weather information at the current location of the vehicle obtained from an external device via a communication device, or the weather may be estimated based on an image of the area around the vehicle captured by a camera.

[0054] The present disclosure has the following additional configurations. (Supplementary Note 1) A device for controlling the operation of a headlamp capable of emitting a low beam and a selective high beam, comprising: a controller connected to the headlamp; and a forward monitoring sensor connected to the controller and configured to detect a forward vehicle present in front of a host vehicle, wherein the controller is configured to: control the headlamp to emit the selective high beam including a dimming range according to the position of the forward vehicle detected by the forward monitoring sensor; and when the forward vehicle is present on a first side, which is either the left or right side of the host vehicle, of an oncoming lane, control the headlamp to dim at least a partial range that partially overlaps with the illumination range of the low beam at a first dimming rate if the weather around the host vehicle is estimated to be rainy, and to dim at a second dimming rate relatively smaller than the first dimming rate if the weather is estimated not to be rainy; wherein light is irradiated onto the partial range in conjunction with irradiation of the high beam; and the low beam has an upper end at a position equal to or lower than the height of the horizon relative to the position of the headlamp, a first portion located on a second side opposite to the first side with respect to the vertical line and extending in a substantially horizontal direction so as to substantially overlap with the horizontal line, a second portion located on the first side with respect to the vertical line and extending in a substantially horizontal direction relatively lower than the first portion, and a third portion connecting ends of the first portion and the second portion and obliquely intersecting the vertical line so as to overlap with the horizontal line. (Supplementary Note 4) The headlamp control device according to any one of Supplementary Notes 1 to 3, wherein the controller estimates the weather based on an operating state of a wiper switch provided in the host vehicle.(Supplementary Note 5) The headlamp control device according to any of Supplementary Notes 1 to 3, wherein the controller estimates the weather based on a detection signal from a sensor that can directly detect raindrops, weather information at the current position of the vehicle acquired via communications, or an image obtained by photographing the area around the vehicle. (Supplementary Note 6) The headlamp control device according to any of Supplementary Notes 1 to 5, wherein the headlamp includes a first unit that irradiates the low beam, a second unit that irradiates the selective high beam, and a third unit that irradiates the partial area with an additional beam, and the controller dims the partial area by dimming the additional beam from the third unit. (Supplementary Note 7) A method executed by a controller connected to a headlamp to control the operation of the headlamp capable of emitting a low beam and a selective high beam, the method comprising: controlling the headlamp to emit the selective high beam including a dimming range according to the position of a forward vehicle present in front of the host vehicle; controlling the headlamp to dim at least a partial range that partially overlaps with the illumination range of the low beam at a first dimming rate when the weather around the host vehicle is estimated to be rainy, and at a second dimming rate relatively smaller than the first dimming rate when the weather is estimated not to be rainy, when the forward vehicle is present on a first side, which is either the left or right side of the host vehicle, in an oncoming lane; wherein light is irradiated onto the partial range in conjunction with irradiation of the high beam; the low beam has an upper end at a position equal to or lower than the height of the horizon based on the position of the headlamp; a headlamp control method, wherein the partial range is a range from the upper end to a position higher than the lower end of the low beam, and at least a high illuminance band is set in the first range with respect to a vertical line based on the position of the headlamp. (Supplementary Note 8) A headlamp system comprising: the control device according to any of Supplements 1 to 6; and a headlamp capable of emitting a low beam and a selective high beam, the operation of which is controlled by the control device.

[0055] 10: Controller, 11: Forward monitoring sensor, 12: Steering angle sensor, 13L, 13R: Headlight, 14: Lamp switch, 20: Light distribution pattern setting unit, 21: Control signal generation unit, 30: Low beam unit, 31: ADB unit, 32: Additional beam unit, 50: Low beam, 51: High beam, 52a, 52b: Additional beam, 53: Dimming range, 100: Vehicle, 110: Oncoming vehicle, 120: Leading vehicle

Claims

1. A device for controlling the operation of a headlamp capable of emitting a low beam and a selective high beam, comprising: a controller connected to the headlamp; and a forward monitoring sensor connected to the controller and configured to detect a forward vehicle present in front of a host vehicle, wherein the controller is configured to: control the headlamp to emit the selective high beam including a dimming range according to the position of the forward vehicle detected by the forward monitoring sensor; and when the forward vehicle is present on a first side, which is either the left or right side of the host vehicle, of an oncoming lane, control the headlamp to dim at least a partial range that partially overlaps with the illumination range of the low beam at a first dimming rate if the weather around the host vehicle is estimated to be rainy, and to dim at a second dimming rate relatively smaller than the first dimming rate if the weather is estimated not to be rainy; wherein light is irradiated onto the partial range in conjunction with irradiation of the high beam; and the low beam has an upper end at a position below the height of the horizon based on the position of the headlamp, the partial range is a range from the upper end to a position higher than the lower end of the low beam, and at least a high illuminance band is set in the first range with respect to a vertical line based on the position of the headlamp.

2. The headlamp control device according to claim 1, wherein the controller further controls the headlamp so as to maintain brightness in the partial range without dimming when the forward vehicle is not present on the first side.

3. A headlamp control device as described in claim 1, wherein the upper end of the low beam includes a first portion located on a second side opposite the first side with respect to the vertical line and extending in a substantially horizontal direction so as to substantially overlap with the horizontal line, a second portion located on the first side with respect to the vertical line and extending in a substantially horizontal direction relatively lower than the first portion, and a third portion connecting each end of the first portion and the second portion and intersecting the vertical line obliquely so as to overlap with the vertical line.

4. The headlamp control device according to claim 1, wherein the controller estimates the weather based on the operating state of a wiper switch provided on the vehicle.

5. A headlamp control device as described in claim 1, wherein the controller estimates the weather based on either a detection signal from a sensor that can directly detect raindrops, weather information at the current location of the vehicle obtained via communication, or an image obtained by photographing the area around the vehicle.

6. A headlamp control device according to claim 1, wherein the headlamp includes a first unit that irradiates the low beam, a second unit that irradiates the selective high beam, and a third unit that irradiates the partial range with an additional beam, and the controller dims the partial range by dimming the additional beam emitted by the third unit.

7. A method executed by a controller connected to a headlamp for controlling the operation of a headlamp capable of emitting a low beam and a selective high beam, comprising: controlling the headlamp to emit the selective high beam including a dimming range according to the position of a forward vehicle present in front of the host vehicle; and controlling the headlamp to dim at least a partial range that partially overlaps with the low beam illumination range at a first dimming rate when the weather around the host vehicle is estimated to be rainy, and at a second dimming rate relatively smaller than the first dimming rate when the weather is estimated not to be rainy, when the forward vehicle is present on a first side, which is either the left or right side of the host vehicle, in an oncoming lane; wherein light is irradiated onto the partial range in conjunction with the irradiation of the high beam; and wherein the low beam has an upper end at a position below the height of the horizon based on the position of the headlamp; the partial range is a range from the upper end to a position higher than the lower end of the low beam, and at least a high illuminance band is set in the first range with respect to a vertical line based on the position of the headlamp.

8. A headlamp system comprising: the control device according to claim 1; and a headlamp capable of emitting a low beam and a selective high beam, the operation of which is controlled by said control device.

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