Vehicle lighting system

Abstract

Provided is a vehicle lighting system for improving pedestrian visibility and providing a warning to pedestrians.　This vehicle lighting system comprises: a variable light-distribution headlamp; an object sensor configured to detect an object around a vehicle; and a controller connected to the object sensor and the headlamp and configured to control operation of the headlamp on the basis of a detection result of the object sensor, wherein the controller is configured to estimate, as the object, at least a position of a road lane marking, and controls the headlamp to irradiate, forward of the vehicle, a beam that at least partially overlaps the estimated position of the lane marking and has, in plan view, a shape that increases in width with distance from the vehicle.

Description

Vehicle lighting system

[0001] The present disclosure relates to a vehicle lighting system.

[0002] Japanese Patent Application Laid-Open No. 2020-142796 (Patent Document 1) describes a technique of irradiating light so as to overlap with each lane line such as a white line drawn on a road in order to indicate the range of a driving lane on the road.

[0003] According to the above prior art, it is considered that it contributes to improving the visibility of lane lines for the driver of a vehicle. However, when there are pedestrians trying to cross the road, there is room for improvement from the viewpoints of improving the visibility of pedestrians for the driver and giving a warning to pedestrians.

[0004] Japanese Patent Application Laid-Open No. 2020-142796

[0005] One of the objects of the specific aspect according to the present disclosure is to provide a technique capable of improving the visibility of pedestrians and giving a warning to pedestrians.

[0006] A vehicle lighting system according to an aspect of the present disclosure includes: a headlamp with variable light distribution; an object sensor configured to be able to detect an object around the vehicle; and a controller connected to each of the object sensor and the headlamp, and configured to control the operation of the headlamp based on a detection result by the object sensor. The controller is configured to be able to estimate at least the position of a lane line on a road as the object, and the controller controls the headlamp to irradiate the front of the vehicle with a beam that overlaps at least a part of the estimated position of the lane line and has a planar view shape in which the width increases as it moves away from the vehicle. It is a vehicle lighting system.

[0007] According to the above configuration, it is possible to improve the visibility of pedestrians and give a warning to pedestrians.

[0008] Figure 1 is a block diagram showing the configuration of a vehicle lighting system according to the first embodiment. Figure 2 is a block diagram showing an example of the configuration of a computer system. Figures 3(A) and 3(B) are schematic diagrams illustrating example configurations of the left and right headlights. Figure 4 is a diagram showing an example configuration of a high-beam unit capable of emitting selective high beams. Figure 5 is a diagram illustrating a specific example of illumination light emitted by a vehicle lighting system. Figure 6(A) is a schematic diagram showing the illumination status of a lane marking-enhancing beam as seen from the driver's seat of the vehicle. Figure 6(B) is a schematic diagram showing the illumination status of a lane marking-enhancing beam of a comparative example as seen from the driver's seat of the vehicle. Figure 7 is a flowchart showing the operation procedure of the vehicle lighting system according to the first embodiment. Figure 8 is a diagram illustrating a specific example of illumination light of a modified example. Figure 9(A) is a diagram illustrating a specific example of illumination light of a modified example. Figure 9(B) is a timing chart showing the illumination timing of each segment in the lane marking-enhancing beam of a modified example. Figure 10(A) is a diagram illustrating a specific example of illumination light of a modified example. Figure 10(B) is a timing chart showing the illumination timing of each segment in the modified lane marking-enhanced beam. Figure 11(A) is a diagram illustrating a specific example of the illumination light in the modified example. Figure 11(B) is a timing chart showing the illumination timing of each segment in the modified lane marking-enhanced beam. Figure 12(A) is a diagram illustrating a specific example of the illumination light in the modified example. Figure 12(B) is a timing chart showing the illumination timing of each segment in the modified lane marking-enhanced beam. Figure 13 is a diagram illustrating the relationship between two frames in apparent motion. Figure 14 is a diagram illustrating the relationship between presentation time, off time, and on-time interval at several frame rates. Figures 15(A) and 15(B) are diagrams illustrating specific examples of the illumination light in the modified example. Figures 16(A) to 16(D) are diagrams illustrating specific examples of the illumination light in the vehicle lighting system of the second embodiment. Figures 17(A) to 17(D) are diagrams illustrating modified examples of the illumination light in the vehicle lighting system of the second embodiment. Figure 18 is a flowchart showing the operation procedure of the vehicle lighting system of the second embodiment. Figures 19(A) to 19(C) show specific examples of the emitted light in the vehicle lighting system of the third embodiment.Figure 20 is a flowchart showing the operation procedure of the vehicle lighting system according to the third embodiment.

[0009] (First Embodiment) Figure 1 is a block diagram showing the configuration of a vehicle lighting system according to the first embodiment. The illustrated vehicle lighting system consists of a controller 1, a camera 2, a millimeter-wave radar 3, a LiDAR (Light Detection And Ranging) 4, a headlight switch 5, map data 6, a GPS sensor 7, a communication unit 8, and a pair of headlights, the right headlight 9R and the left headlight 9L. This vehicle lighting system illuminates the area in front of the vehicle using the right headlight 9R and the left headlight 9L in response to operation of the headlight switch 5 installed on the vehicle.

[0010] Controller 1 controls the illumination of the right headlight 9R and the left headlight 9L based on the position of an object obtained by the camera 2, etc. This controller 1 can be configured using a computer system that includes, for example, a processor 201, a ROM (Read Only Memory) 202, a RAM (Random Access Memory) 203, a storage device 204, an input / output unit (IF) 205, etc., as shown in Figure 2. The program 206 stored in the storage device 204 is read and executed by the processor 201, thereby realizing the functions described later.

[0011] Camera 2, millimeter-wave radar 3, and LiDAR 4 detect the position and type of objects present around the vehicle. These objects include, for example, pedestrians, bicycles (and their drivers), motorcycles, preceding vehicles, oncoming vehicles, and lane markings on the road surface. Lane markings refer to continuous or dashed lines, such as white or amber, placed on the road to delineate driving lanes. Furthermore, the position and type of objects may also be obtained by receiving information from external systems such as road infrastructure (for example, information detected by sensors at intersections) via the communication unit 8. In other words, in this embodiment, at least one of the cameras 2, millimeter-wave radar 3, LiDAR 4, and communication unit 8 functions as an "object sensor."

[0012] Camera 2 detects the position of the aforementioned objects, their type (pedestrians, bicycles, preceding vehicles, oncoming vehicles, etc.), and the distance between the objects and the vehicle by analyzing the images obtained from capturing the space around the vehicle. The image analysis function may also be provided on the controller 1 side.

[0013] The millimeter-wave radar 3 emits radio waves in the frequency band of, for example, 30 GHz to 300 GHz, and detects the position, type, and distance between objects based on the reflected waves generated.

[0014] LiDAR4 detects the position, type, and distance between objects based on the reflected light generated by irradiating them with laser light.

[0015] Map data 6 is data that associates road-related information, specifically road type (national roads, prefectural roads, etc.), number of road lanes, and the location and type of road markings, with the location of each road. By referring to map data 6 according to the location of the vehicle, which is determined by a GPS sensor (not shown), data about the road the vehicle is traveling on can be obtained. This map data 6 may be the map data from a navigation system (not shown) installed in the vehicle, or dedicated map data may be provided.

[0016] The GPS sensor 7 detects the current location by receiving radio waves from the Global Positioning System. This allows the vehicle's current location to be determined.

[0017] The communication unit 8 transmits and receives information via wireless communication. This allows it to receive information from road infrastructure and other external systems.

[0018] The right headlight 9R and the left headlight 9L are mounted at predetermined positions on the left and right sides of the front of the vehicle and operate in accordance with control signals provided by the controller 1 to illuminate the front of the vehicle with a desired light distribution pattern.

[0019] The right-side headlight 9R includes an ADB unit 51R and a low-beam unit 52R. The ADB unit 51R is configured to emit a normal high beam within the illumination range of the high beam (driving light), and to emit light with a light distribution pattern in which the light illumination range and dimming range can be freely set. In other words, the ADB unit 51R is configured to emit a variable light distribution beam. The low-beam unit 52R is configured to emit a low beam (passing light).

[0020] Similarly, the left headlight 9L includes an ADB unit 51L and a low beam unit 52L. The ADB unit 51L is configured to emit a normal high beam within the illumination range of the high beam (driving light), and to emit light with a light distribution pattern in which the light illumination range and dimming range can be freely set. In other words, the ADB unit 51L is configured to emit a variable light distribution beam. The low beam unit 52L is configured to emit a low beam (passing light).

[0021] The controller 1 described above includes the following functions obtained by program execution in the processor: an illumination state setting unit (illumination state setting function) 11, a light distribution control unit (light distribution control function) 12, an object position acquisition unit (object position acquisition function) 13, a road surface condition determination unit (road surface condition determination function) 14, a glare detection unit (glare detection function) 15, and an object position estimation unit (object position estimation function) 16.

[0022] The irradiation state setting unit 11 sets the light distribution pattern (irradiation state) within the irradiation range of the high beams by each ADB unit 51R, 51L based on the detection results from the camera 2, which functions as an object sensor, specifically the position, type, and distance between the detected objects.

[0023] The light distribution control unit 12 generates control signals to realize the light distribution pattern set by the irradiation state setting unit 11 and outputs them to each ADB unit 51R, 51L. The light distribution control unit 12 also outputs control signals to the low beam units 52R, 52L to irradiate them with low beams.

[0024] The object position acquisition unit 13 acquires the position of a specific object among the objects detected by the camera 2, which functions as an object sensor. The acquisition of the position of a specific object, as used here, means acquiring the position of at least the lane markings on the road, and may further include acquiring the positions of pedestrians, oncoming vehicles, preceding vehicles, etc.

[0025] The road surface condition determination unit 14 determines whether the road surface is wet based on the image captured by the camera 2. For example, the road surface condition determination unit 14 can determine whether the road surface is wet based on the brightness of the portion of the road surface included in the image. The road surface condition determination unit 14 may also determine the road surface condition based on weather information obtained through communication with an external source, or based on the detection result of another sensor (e.g., a wetness sensor) not shown.

[0026] The glare detection unit 15 detects the possibility of glare generation caused by the illumination light formed by the right headlight 9R or the left headlight 9L. Further details will be described later.

[0027] The object position estimation unit 16 estimates the position of lane markings when they cannot be partially detected on the road. For example, the position of lane markings is estimated in various cases, such as when part of the lane markings is faded and cannot be detected, when the lane markings disappear due to bending, etc., when driving straight at an intersection or on an uphill slope, when lane markings cannot be detected except in the vicinity or far from the vehicle due to bad weather, ambient light, or obstruction by other vehicles, or when lane markings are not approximately parallel to the direction of travel of the vehicle in a parking lot, etc.

[0028] As a method for estimating the position of lane markings by the object position estimation unit 16, for example, the position of lane markings can be estimated based on road data of the current location that can be identified using map data 6 and GPS sensor 7. In this case, the position of lane markings may also be estimated based on the number of lanes, road width and road structure regulations. Furthermore, based on the position of lane markings already detected by the object position acquisition unit 13, the portion of the lane markings that has not been detected can also be estimated by methods such as straight line approximation. In addition, the position of lane markings can also be estimated from the positions of road structures (curbs, guardrails, walls, etc.) and surrounding vehicles that can be detected by the object position acquisition unit 13. Moreover, lane markings can also be estimated by setting a virtual line that is approximately parallel to the direction of travel of the vehicle.

[0029] Figures 3(A) and 3(B) are schematic diagrams illustrating the configuration examples of the left and right headlights. While each figure shows the configuration example of the left headlight 9L, the configuration is similar for the right headlight 9R. Figure 3(A) schematically shows the configuration of the left headlight 9L in the vehicle lighting system 1 shown in Figure 1. Specifically, the low beam unit 52L illuminates the area in front of the vehicle with a low beam LB, and the high beam unit 51L illuminates the area in front of the vehicle with a high beam HB. The high beam HB may be a selective high beam (ADB). In this configuration example, the illumination range of the high beam HB illuminated by the high beam unit 51L is set such that its lower end position is close to the lower end position of the low beam LB. Furthermore, the configuration example shown in Figure 3(B) is one in which the functions of the low beam unit 52L and the high beam unit 51L are integrated into a high-definition light source unit 53L. In this configuration example, the irradiation range of the high beam HB, which is irradiated by the high-definition light source unit 53L, is set such that its lower end position is close to the lower end position of the low beam LB.

[0030] In each of the above configuration examples, the high-beam unit 51L (51R) and the high-definition light source unit 53L (53R), which are capable of emitting a selective high beam, 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 51L, 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 51L, etc., can also be configured using a light source with a large number of extremely small LEDs densely mounted and a lens optical system that projects the light emitted from the light source.

[0031] Figure 4 shows an example configuration of a high-beam unit capable of selectively emitting high beams. The illustrated high-beam unit 51L (51R) can be configured using a variable light distribution unit that has a light source 60 equipped with a plurality of light-emitting elements (e.g., LEDs: Light Emitting Diodes) and a lens 61 that projects the light emitted from the light source 60, and is configured to allow individual control of the on / off state and luminous intensity (brightness) of each light-emitting element. By individually controlling the on / off state and luminous intensity of each light-emitting element, it is possible to generate illumination light with a variable light distribution that includes a dimming range 63 at any position in the light irradiation range 62. In this specification, "dimming" is a concept that includes not only relatively reducing the brightness but also reducing the brightness to zero (i.e., blocking the light).

[0032] Figure 5 is a diagram illustrating a specific example of illumination light emitted by a vehicle lighting system. Figure 5 shows a schematic plan view of the vehicle traveling on a road, viewed from above. More specifically, it schematically shows a situation where the vehicle 100 is traveling on a single-lane road and a pedestrian b is located to the right front of the vehicle 100. The vehicle 100 is illuminated by a lane marking beam 110 and a low beam 120. The low beam 120 is formed by low beam units 52L and 52R and illuminates a range relatively close to the vehicle 100. In addition, the lane marking beam 110 in the illustrated example is illuminated on the road surface to the right front of the vehicle 100. A portion of the lane marking beam 110 on the side closer to the vehicle 100 overlaps with the illumination range of the low beam 120. The lane marking beam 110 is formed by the ADB unit 51R of the right headlight 9R.

[0033] In a plan view, the lane marking enhancement beam 110 is illuminated such that its inner outer edge (first outer edge) 110a, that is, the side closer to the vehicle 100's driving lane (the side closer to the lane marking d), is approximately parallel to the driving lane. The outer edge (second outer edge) 110b, that is, the side further from the vehicle 100's driving lane (the side further from the lane marking d), is illuminated such that it is not parallel to the driving lane. In other words, the outer edge 110b is illuminated such that the distance from the lane marking d gradually increases as it moves away from the vehicle 100. As a result, the lane marking enhancement beam 110 as a whole has a plan view shape in which its width increases as it moves away from the vehicle 100. The width of the lane marking enhancement beam 110 here refers to its length in the direction of the lane width in the figure. It is preferable that the inner outer edge 110a of the lane marking enhancement beam 110 is set relatively outward in the area in front of the vehicle 100 so as not to exceed the optical axis c1 of the ADB unit 51R of the right headlight 9R. This suppresses the reduction in driver visibility due to the light curtain phenomenon in rainy weather, etc. The illumination mode of the white line enhancement beam 110 can be, for example, continuous illumination, but it may also be flashing illumination (intermittent illumination).

[0034] Figure 6(A) schematically shows the illumination of the lane marking enhancement beam as seen from the driver's seat of the vehicle. By illuminating with a lane marking enhancement beam 110 that spreads outward from the vehicle, in addition to the effect of highlighting the lane marking d, if a pedestrian b crossing the road is near the lane marking d, the area 150 at the feet of the pedestrian b is illuminated. The size (area) of this area 150 at the feet of the pedestrian b is larger than that of the comparative example illustrated in Figure 6(B), namely, the area 1150 at the feet of the pedestrian b when light is illuminated by a beam 1110 that narrowly illuminates only the lane marking d. As a result, the visibility of the pedestrian b from the driver's side is improved. Also, the pedestrian will be more likely to notice the approaching vehicle, so it can effectively alert them.

[0035] Figure 7 is a flowchart showing the operation procedure of the vehicle lighting system according to the first embodiment. Note that the order of the processes shown here can be changed as long as it does not result in inconsistencies or contradictions in the information processing results, and other processes not explicitly shown here can also be added.

[0036] If the headlight switch is not in the ON state (step S11; NO), the process in step S11 is repeated. If, after the processes described later in step S12 have been executed and the left headlight 9L and right headlight 9R have been illuminated, the headlight switch becomes not ON (i.e., OFF), the right headlight 9R and left headlight 9L are turned off based on the control signal from the light distribution control unit 12.

[0037] When the headlight switch 5 is turned on by the driver (step S11; YES), the object position estimation unit 16 of the controller 1 estimates the position of the lane markings using the detection results of the camera 2 and other object sensors, data obtained from the map data 6, the current position detected by the GPS sensor 7, and information acquired by the communication unit 8 as appropriate (step S12).

[0038] The illumination state setting unit 11 sets the illumination state of the lane marking enhancement beam 110 according to the position of the lane markings estimated by the object position estimation unit 16. A control signal based on this set illumination state is generated by the light distribution control unit 12 and output to the ADB unit 51R of the right headlight 9R, thereby illuminating the lane marking enhancement beam 110 (step S13).

[0039] When a preceding vehicle and / or an oncoming vehicle (collectively referred to as "surrounding vehicles") is detected by the camera 2 or other object sensor (step S14), the object position acquisition unit 13 acquires the position of the surrounding vehicles (step S15). The position of the surrounding vehicles is determined, for example, by the relative angle and relative distance with respect to the vehicle itself.

[0040] The road surface condition determination unit 14 determines whether the road surface is wet or not based on the road portion of the image captured by the camera 2 (step S16). If the road surface is wet (step S16; YES), the glare detection unit 15 detects whether or not there is glare to surrounding vehicles due to specular reflection of the light forming the lane marking enhancement beam on the road surface (step S17).

[0041] Here, the presence or absence of glare due to specular reflection on the road surface is determined by calculating the trajectory of light traveling from the headlight towards the road surface based on, for example, the illumination state (illumination position) of the lane marking enhancement beam on the road surface, the position of the headlight forming this lane marking enhancement beam (in the above example, the position of the ADB unit 51R of the right headlight 9R), and the relative position of the driver's seat of the surrounding vehicle. If the light can enter the driver's seat of the surrounding vehicle, it is determined as "glare present," and if it does not enter, it is determined as "no glare."

[0042] On the other hand, if the road surface is not wet (step S16; NO), the process in step S17 is omitted and the process proceeds to step S18. In this case, the glare detection unit 15 detects whether or not there is glare on surrounding vehicles due to the direct irradiation of light that forms the lane marking enhancement beam (step S18).

[0043] Here, the presence or absence of glare on surrounding vehicles due to direct illumination can be determined by calculating the trajectory of light traveling from the headlight based on the relative positional relationship between the position of the headlight forming the lane marking enhancement beam (in the above example, the position of the ADB unit 51R of the right headlight 9R) and the position of the driver's seat of the surrounding vehicle. If the light can enter the driver's seat of the surrounding vehicle, it is determined as "glare present," and if it does not enter, it is determined as "no glare."

[0044] When there is glare caused by at least one of specular reflection and direct irradiation (step S19; YES), the irradiation state setting unit 11 sets the irradiation state so as to reduce the light intensity of the portion of the irradiation range of the lane line highlighting beam 110 that causes the glare based on the detection result of the glare detection unit 15. A control signal based on this set irradiation state is generated by the light distribution control unit 12 and output to the ADB unit 51R of the right front headlamp 9R, whereby the lane line highlighting beam 110 is partially dimmed (step S20). Note that the concept of "dimming" in this specification includes reducing the brightness (luminance, illuminance, etc.) of the portion to zero. On the other hand, when there is no glare (step S19; NO), the process returns to step S11 without performing partial dimming of the lane line highlighting beam.

[0045] Next, a modified example of the irradiation mode of the lane line highlighting beam will be described. FIGS. 8 and 9(A) are diagrams for explaining specific examples of the illumination light of the modified example. In FIG. 8, as in FIG. 5, a schematic plan view shows a state of the host vehicle traveling on the road as viewed from above. The lane line highlighting beam 111 of the modified example is divided into three segments seg1 to seg3 along the traveling direction of the host vehicle 100 and is sequentially irradiated from the front segment seg1 close to the host vehicle 100. FIG. 9(A) schematically shows this sequential irradiation state. The lane line highlighting beam 111 of this modified example finally reaches a state where all of the segments seg1 to seg3 are irradiated. That is, the lane line highlighting beam 111 is finally irradiated in the same state as the lane line highlighting beam 110 illustrated in FIG. 5 described above. Also, in the illustrated example, the lane line highlighting beam 111 is irradiated so as not to overlap with the low beam 120, but the lane line highlighting beam 111 and the low beam 120 may be irradiated so as to partially overlap with each other.

[0046] Figure 9(B) is a timing chart showing the illumination timing of each segment in a modified lane marking enhancement beam. First, segment seg1, which is closest to the vehicle 100, is illuminated (ON), then segment seg2 is illuminated while segment seg1 is still illuminated, and finally segment seg3 is illuminated while segments seg1 and seg2 are still illuminated. In other words, each segment seg1 to seg3 is illuminated at a different time. The illumination period for each segment seg1 to seg3 can be set arbitrarily, but as an example, if the unit time is 1 frame, segment seg1 is illuminated for 3 frames, segment seg2 is illuminated for 2 frames, and segment seg3 is illuminated for 1 frame. After that, illumination of all segments seg1 to seg3 ends (OFF). This pattern of sequential illumination of segments seg1 to seg3 and then complete blackout may be repeated at regular intervals.

[0047] Figure 10(A) is a diagram illustrating a specific example of the illumination light of the modified example. Figure 10(B) is a timing chart showing the irradiation timing of each segment in the lane marking enhancement beam of the modified example. The lane marking enhancement beam 112 of this modified example is divided into eight segments seg1 to seg8 along the direction of travel of the vehicle 100, and is irradiated sequentially starting from segment seg1, which is closer to the vehicle 100. In detail, in the lane marking enhancement beam 112 of this modified example, segment seg1 is irradiated first, then in the next frame, segment seg2 is irradiated while the irradiation of segment seg1 is maintained, and in the next frame, segment seg3 is irradiated while the irradiation of segments seg1 and seg2 is maintained.

[0048] In the next frame, the irradiation of segment seg1 irradiated for three frames is stopped, and while the irradiation of segments seg2 to seg3 is maintained, segment seg4 is newly irradiated. Hereinafter, every time the next frame is reached, the irradiation of the segment irradiated for three frames is stopped, and the irradiation of each segment is controlled in a pattern in which the third segment counted from the segment whose irradiation has been stopped is newly irradiated. In FIG. 10(B), a timing chart of the irradiation patterns of segments seg1 to 5 is shown. The irradiation of segments seg6 and subsequent segments whose illustration is omitted is similarly controlled.

[0049] At this time, the section line highlighting beam 112 composed of segments seg1 to 8 has the same planar shape as the section line highlighting beam 110 described above as a whole. Further, in this modification, each segment is provided with a gap between adjacent segments along the direction away from the host vehicle. And when comparing two adjacent segments, the width of each segment is set so that the width of the segment farther from the host vehicle becomes wider. For example, when comparing segments seg1 and seg2, segment seg2, which is farther from the host vehicle, is wider than segment seg1. Also, in this example, the planar shape of each of segments seg1 to 8 is a rectangular shape (square shape). Note that the features of the width and planar shape of each segment are common also in the modifications shown in FIGS. 11(A) and 12(A) described later.

[0050] By continuously switching the segments to be irradiated in this way, it is possible to generate a virtual motion phenomenon, which is a phenomenon in which something that is originally not moving appears to be moving virtually. Thereby, it is possible to make the driver and pedestrians feel that the bright spots by each segment move on the road surface from the host vehicle toward the pedestrians. Particularly, from the perspective of pedestrians, the bright spots appear to be coming toward themselves, so it is possible to strongly draw the attention of pedestrians. As a result, it is possible to suppress pedestrians from suddenly jumping out in front of the vehicle.

[0051] Figure 11(A) is a diagram illustrating a specific example of the modified illumination light. Figure 11(B) is a timing chart showing the irradiation timing of each segment in the modified lane marking enhancement beam. This modified lane marking enhancement beam 113 has multiple bright spots that change similarly to the modified lane marking enhancement beam 112 described above. Specifically, in the illustrated example, at each time, there are multiple bright spots, such as bright spots composed of two to three adjacent segments irradiated and bright spots composed of one segment irradiated, and these bright spots change continuously so that they move away from the position close to the vehicle. The same effect as described above can be obtained with such a lane marking enhancement beam.

[0052] Figure 12(A) is a diagram illustrating a specific example of the illumination light of the modified example. Figure 12(B) is a timing chart showing the irradiation timing of each segment in the modified example's border-enhancing beam. This modified example's border-enhancing beam 114 is configured such that, at one time, the odd-numbered segments seg1, 3, 5, and 7 of segments seg1 to 8 are irradiated, at the next time, the even-numbered segments seg2, 4, 6, and 8 of segments seg1 to 8 are irradiated, and thereafter, the odd-numbered segments and even-numbered segments are irradiated alternately. Considering the transition between the two time periods, each segment is irradiated in such a way that apparent motion occurs between two adjacent segments. For example, considering the relationship between segments seg1 and seg2, at one time segment seg1 is irradiated, and at the next time segment seg2 is irradiated, and this relationship is repeated, causing apparent motion to occur between segments seg1 and seg2. The same effect as described above can be obtained with such a border-enhancing beam.

[0053] Here, the favorable conditions for apparent motion will be explained in detail. Figure 13 is a diagram illustrating the relationship between two frames in apparent motion. Here, the first frame is referred to as "frame 1," and the next frame as "frame 2." The duration of each frame is defined as "presentation time (X)," the blackout time between frame 1 and frame 2 is defined as "ISI (Y)," and the on-time interval between the start of frame 1 and the start of frame 2 is defined as "SOA (Z)." All units are in milliseconds.

[0054] Let's assume there are two frames like this. If the frame rate (FPS), which is the number of frames per second, is greater than 20 FPS, a strong apparent motion is generated by creating a blackout period (non-illumination period) between frame 1 and frame 2. On the other hand, if the frame rate is less than 20 FPS, a strong apparent motion is generated by switching the illumination on a frame-by-frame basis. Note that this is just one example, and a blackout period may or may not be included regardless of the frame rate.

[0055] When the presentation time (X) is short (X < 100 msec), the intensity of apparent motion is mainly determined by the on-time interval SOA(Z). The preferred value for the on-time interval is 50 to 200 msec. When the presentation time (X) is long (X ≥ 100 msec), the intensity of apparent motion is mainly determined by the off-time ISI(Y). The peak value for the off-time is 0 msec.

[0056] Figure 14 illustrates the relationship between presentation time, blackout time, and on-time interval at several frame rates. For example, when the frame rate is 10 FPS or more but less than 20 FPS, the presentation time and blackout time for frames 1 and 2 are approximately the same length. When the frame rate is 20 FPS, the presentation times for frames 1 and 2 are the same, and the blackout time is 0 msec. When the frame rate is 40 FPS, the presentation time and blackout time for frames 1 and 2 are also approximately the same length. When the frame rate is 80 FPS, the presentation times for frames 1 and 2 are approximately the same length, and these presentation times are shorter compared to their respective blackout times.

[0057] Figures 15(A) and 15(B) show specific examples of modified illumination. As shown in Figure 15(A), in addition to the lane marking enhancement beam 110R for the lane marking located on the right side (driver's side) relative to the vehicle 100, a lane marking enhancement beam 110L located on the left side (farther from the driver's seat) relative to the vehicle 100 may also be illuminated. In this case, the lane marking enhancement beam 110R may be formed by the right headlight 9R, and the lane marking enhancement beam 110L may be formed by the left headlight 9L. Alternatively, as shown in Figure 15(B), only the lane marking enhancement beam 110L on the left side relative to the vehicle 100 may be illuminated. Although a continuously illuminated lane marking enhancement beam has been described as an example here, illumination on the left side relative to the vehicle 100 may also be added in the same manner for lane marking enhancement beams that are illuminated in sections.

[0058] Furthermore, in each irradiation mode of the lane marking enhancement beam, a difference in illumination may be provided between the portion directly above the lane marking and the portion other than it. Specifically, the portion other than the portion directly above the lane marking may be made relatively brighter. Also, the irradiation mode may be switched depending on the presence or absence of pedestrians. For example, if there are no pedestrians among the objects detected by the camera 2 as an object sensor, etc., a continuous irradiation lane marking enhancement beam may be irradiated, and if pedestrians are present, the system may be switched to a lane marking enhancement beam that is irradiated section by section.

[0059] Furthermore, if it can be determined from the map data 6 that the vehicle is traveling on a highway, the illumination of the lane markings using the illumination modes described above may be stopped, and the system may switch to the conventional enhancement beam that selectively illuminates only the lane markings. This is because it can be determined that there are no pedestrians on the road when traveling on a highway.

[0060] Furthermore, in the embodiment in which the lane marking enhancement beam is irradiated in sections, in addition to irradiating each segment from the side closer to the vehicle and moving away from it as described above, each segment may also be irradiated from the side further away from the vehicle and moving towards it, or each segment may be irradiated to move back and forth between a position close to the vehicle and a position far away from it. In any of these cases, the irradiation of the segments in a constant pattern may be repeatedly performed. The light irradiation to each segment may be instantaneous or blinking. The size of the bright spot and the apparent movement speed may be constant or not.

[0061] Alternatively, the system may irradiate with a first beam (enhanced beam) that is irradiated in a linear planar shape that mainly overlaps with the lane lines, and a second beam (laminated with lane line enhanced beam) that is irradiated in such a way that it creates apparent motion through partial irradiation as described in the above embodiment.

[0062] According to the first embodiment described above, a vehicle lighting system is provided that can improve the visibility of pedestrians and also alert pedestrians to the dangers of the vehicle.

[0063] (Second Embodiment) It is also preferable to set the illumination range of the lane marking enhancement beam to be variable according to the position of the oncoming vehicle. The vehicle lighting system of this second embodiment will be described below. Note that the configuration of the vehicle lighting system is the same as that of the first embodiment described above, so the explanation will be omitted here.

[0064] Figures 16(A) to 16(D) show specific examples of the emitted light in the vehicle lighting system of the second embodiment. In this embodiment, as shown in Figure 16(A), the maximum irradiable distance K of the lane marking enhancement beam is defined. This maximum irradiable distance K is a value that can be determined by assuming the vehicle speed of the vehicle 100, the pedestrian's crossing speed, the road width, etc. As a preferred example, the maximum irradiable distance K can be set to 75 m. For example, on a straight road, assuming a vehicle speed of 60 km / h, a pedestrian's crossing speed of 1.2 m / s (assuming an elderly person), and a road width of 3.5 m, and assuming a pedestrian crossing the road from the right, if the lateral distance between the center position of the vehicle 100 in the left-right direction and the pedestrian's position is 5.25 m, then it takes 4.4 seconds to cross this 5.25 m. The distance the vehicle travels in 4.4 seconds is approximately 73 m. By adding a small margin to this value of approximately 73 m, the above example value of K = 75 m is obtained.

[0065] In this embodiment, if an oncoming vehicle 200 is closer than the illumination limit distance described above, the illumination of the lane marking enhancement beam is stopped. This state is shown in Figures 16(A) and 16(B). This prevents glare to the oncoming vehicle 200. On the other hand, if the rear position of the oncoming vehicle 200 is closer than the position k which is the illumination limit distance K from the vehicle 100, the lane marking enhancement beam can be illuminated into the empty space to improve the visibility of pedestrians and draw their attention. This state is shown in Figures 16(C) and 16(D). As can be seen by comparing the figures, the length of the lane marking enhancement beam 210 can be set to be variable according to the distance between position k and the rear position of the oncoming vehicle 200. In these cases, the lane marking enhancement beam 210 is formed by the right headlight 9R.

[0066] Figures 17(A) to 17(D) show modified examples of the illumination light in the vehicle lighting system of the second embodiment. As shown in each figure, on the right side where an oncoming vehicle 200 is present, a lane marking enhancement beam 210R, which is set to be variable in the same manner as shown in Figures 16(A) to 16(D) above, may be illuminated, while on the left side where no oncoming vehicle 200 is present, a lane marking enhancement beam 210L may be continuously illuminated. In these cases, the lane marking enhancement beam 210R is formed by the right headlight 9R, and the lane marking enhancement beam 210R is formed by the left headlight 9L.

[0067] In addition, while Figures 16(A) to 16(D) and 17(A) to 17(D) show an example of continuous irradiation for the section line enhancement beam 210 (210R, 210L), the section line enhancement beam may also be formed by sequentially irradiating partial regions in a time-division manner, as described in the first embodiment above.

[0068] Figure 18 is a flowchart showing the operation procedure of the vehicle lighting system of the second embodiment. Note that the order of the processes shown here can be changed as long as it does not result in contradictions or inconsistencies in the information processing results, and other processes not explicitly shown here can be added. This section describes additional information processing performed on the premise that the information processing according to the operation procedure shown in the vehicle lighting system of the first embodiment described above has already been executed.

[0069] The object position acquisition unit 13 of the controller 1 acquires the position of the oncoming vehicle from a camera 2 or the like, which acts as an object sensor (step S30). The glare detection unit 15 detects whether or not there is a possibility of glare occurring due to light distribution within the illumination limit distance, depending on the position of the oncoming vehicle (step S31). It is preferable to detect both the possibility of glare due to direct illumination and the possibility of glare due to specular reflection from the road surface (the same applies below).

[0070] If glare is present (step S32; YES), the illumination state setting unit 11 sets the illumination state to dim or turn off the lane marking enhancement beam. A control signal based on this set illumination state is generated by the light distribution control unit 12 and output to the right headlight 9R and the left headlight 9L, causing the lane marking enhancement beam to dim or turn off (step S33).

[0071] The object position acquisition unit 13 acquires the position of the oncoming vehicle from the camera 2 or other object sensor (step S34). The glare detection unit 15 compares whether the position at the limit of illumination distance or the rear position of the oncoming vehicle is closer to the vehicle 100 (step S35).

[0072] If the rear of the oncoming vehicle is closer (step S36; YES), the glare detection unit 15 detects the presence or absence of glare due to the light distribution (step S37). The illumination state setting unit 11 sets the illumination state so that the lane marking enhancement beam is irradiated only to the rear area of ​​the oncoming vehicle, which is an area within the range determined by the illumination limit distance that does not produce glare. A control signal based on this set illumination state is generated by the light distribution control unit 12 and output to the right headlight 9R and the left headlight 9L, thereby irradiating the lane marking enhancement beam (step S38).

[0073] The object position acquisition unit 13 acquires the position of the oncoming vehicle from the camera 2 or other object sensor (step S39). The glare detection unit 15 compares whether the position at the limit of illumination distance or the rear position of the oncoming vehicle is closer to the own vehicle 100, depending on the position of the oncoming vehicle (step S40).

[0074] If the rear of the oncoming vehicle is closer (step S41; YES), the glare detection unit 15 detects the presence or absence of glare due to the light distribution (step S42). Then, if there is no glare in the entire area within the limit of the illumination distance (step S43; YES), the illumination state setting unit 11 sets the illumination state so that the lane marking-enhanced beam is illuminated in the entire area within the limit of the illumination distance. A control signal based on this set illumination state is generated by the light distribution control unit 12 and output to the right headlight 9R and the left headlight 9L, thereby illuminating the lane marking-enhanced beam (step S44). After that, the process returns to step S30.

[0075] If there is no glare in step S32 (step S32; NO), proceed to step S44. Also, if the rear of the oncoming vehicle is further away in step S36 (step S36; NO), or if the rear of the oncoming vehicle is further away in step S41 (step S41; NO), return to step S34. If there is glare in step S43 (step S43; NO), return to step S34.

[0076] The second embodiment described above also provides a vehicle lighting system that improves pedestrian visibility and can alert pedestrians to the vehicle's presence. Furthermore, when an oncoming vehicle is present, the illumination range of the lane marking enhancement beam is variably set according to its position, thereby preventing glare to oncoming vehicles.

[0077] (Third Embodiment) It is also preferable to set the illumination range of the lane marking enhancement beam to be variable according to the position of the preceding vehicle. The vehicle lighting system of this third embodiment will be described below. Note that the configuration of the vehicle lighting system is the same as that of the first embodiment described above, so the explanation will be omitted here.

[0078] Figures 19(A) to 19(C) show specific examples of the illuminated light in the vehicle lighting system of the third embodiment. As shown in Figure 19(A), when a preceding vehicle 300 is in the same travel lane as the vehicle 100, the lane marking enhancement beams 310R and 310L are illuminated in front of the rear position of the preceding vehicle 300. Also, as shown in Figure 19(B), when the preceding vehicle 300 is located relatively to the right of the vehicle 100 (on the side where the driver's seat is located), the lane marking enhancement beam 310R is not illuminated to the right side of the vehicle 100, and the lane marking enhancement beam 310L is illuminated to the left side of the vehicle 100. Furthermore, as shown in Figure 19(C), if a preceding vehicle 300 is parked in the roadside area to the left of the vehicle 100, the lane marking enhancement beam 310R is directed to the right of the vehicle 100, and the lane marking enhancement beam 310L is directed to an area in front of the front position of the preceding vehicle 300. These illumination methods prevent glare to the preceding vehicle 300. In either case, the lane marking enhancement beam 310R is formed by the right headlight 9R, and the lane marking enhancement beam 310R is formed by the left headlight 9L.

[0079] Figure 20 is a flowchart showing the operation procedure of the vehicle lighting system of the third embodiment. Note that the order of the processes shown here can be changed as long as it does not result in contradictions or inconsistencies in the information processing results, and other processes not explicitly shown here can be added. This section describes additional information processing performed on the premise that the information processing according to the operation procedure shown in the vehicle lighting system of the first embodiment described above has already been executed.

[0080] The object position acquisition unit 13 of the controller 1 acquires the position of the preceding vehicle from a camera 2 or the like, which acts as an object sensor (step S50). The glare detection unit 15 detects whether or not there is a possibility of glare occurring due to light distribution according to the position of the preceding vehicle (step S51). It is preferable to detect both the possibility of glare due to direct illumination and the possibility of glare due to specular reflection from the road surface (the same applies below).

[0081] If glare is present (step S52; YES), the illumination state setting unit 11 sets the illumination state to dim or turn off the lane marking enhancement beam. A control signal based on this set illumination state is generated by the light distribution control unit 12 and output to the right headlight 9R and the left headlight 9L, causing the lane marking enhancement beam to dim or turn off (step S53).

[0082] The object position acquisition unit 13 acquires the position of the preceding vehicle from the camera 2 or the like, which acts as an object sensor (step S54). The glare detection unit 15 compares whether a predetermined position in front of the vehicle (for example, 40 m in front) or the position behind the preceding vehicle is closer to the vehicle 100, according to the position of the preceding vehicle (step S55).

[0083] If the rear of the preceding vehicle is further away (step S56; YES), the glare detection unit 15 detects the presence or absence of glare due to the light distribution (step S57). The illumination state setting unit 11 sets the illumination state so that the lane marking enhancement beam is irradiated only in the rear area of ​​the preceding vehicle, which is an area that does not produce glare. A control signal based on this set illumination state is generated by the light distribution control unit 12 and output to the right headlight 9R and the left headlight 9L, thereby irradiating the lane marking enhancement beam (step S58).

[0084] The object position acquisition unit 13 acquires the position of the preceding vehicle from the camera 2 or the like, which acts as an object sensor (step S59). The glare detection unit 15 compares whether a predetermined position in front of the vehicle or a position behind the vehicle is closer to the vehicle 100, according to the position of the preceding vehicle (step S60).

[0085] If the rear position of the preceding vehicle is farther away (step S61; YES), the glare detection unit 15 detects the presence or absence of glare due to the light distribution (step S62). Then, if there is no glare in the entire area within the limit of the irradiable distance (step S63; YES), the illumination state setting unit 11 sets the illumination state so that the lane marking-enhancing beam is irradiated in the entire area within the limit of the irradiable distance. A control signal based on this set illumination state is generated by the light distribution control unit 12 and output to the right headlight 9R and the left headlight 9L, thereby irradiating the lane marking-enhancing beam (step S64). After that, the process returns to step S50.

[0086] If there is no glare in step S52 (step S52; NO), proceed to step S64. Also, if the rear position of the preceding vehicle is closer in step S56 (step S56; NO), or if the rear position of the preceding vehicle is closer in step S61 (step S61; NO), return to step S54. If there is glare in step S63 (step S63; NO), return to step S54.

[0087] The third embodiment described above also provides a vehicle lighting system that improves pedestrian visibility and can alert pedestrians to the vehicle's presence. Furthermore, when a preceding vehicle is present, the illumination range of the lane marking enhancement beam is variably set according to its position, thereby preventing glare on the preceding vehicle.

[0088] Furthermore, this disclosure is not limited to the contents of each embodiment described above, and can be implemented in various modified forms within the scope of the gist of this disclosure.

[0089] Examples of the features of the present disclosure are given below. (Note 1) A vehicle lighting system comprising: a headlight with variable light distribution; an object sensor configured to detect objects around a vehicle; and a controller connected to the object sensor and the headlight, respectively, and controlling the operation of the headlight based on the detection results of the object sensor, wherein the controller is configured to estimate the position of at least a road marking as the object, and the controller controls the headlight to irradiate the front of the vehicle with a beam that at least a portion overlaps the estimated position of the road marking and has a plan view shape that increases in width as it moves away from the vehicle. (Note 2) The vehicle lighting system according to Note 1, wherein the controller estimates the position of the road marking that has not been detected by the object sensor based on the detection results of the road marking that have been detected by at least the object sensor and road data corresponding to the current position of the vehicle. (Note 3) The vehicle lighting system according to Note 1 or 2, wherein the plan view shape of the beam has a first outer edge near the lane line that is substantially parallel to the lane line, and the distance from the lane line to the second outer edge, which is farther from the lane line, gradually increases as it moves away from the vehicle. (Note 4) The vehicle lighting system according to Note 3, wherein the first outer edge of the beam is set to be located outside the vehicle relative to the optical axis of the headlight. (Note 5) The vehicle lighting system according to any one of Notes 1 to 4, wherein the beam is composed of continuously irradiated light. (Note 6) The vehicle lighting system according to any one of Notes 1 to 4, wherein the beam, in a plan view, has multiple divided parts that are irradiated at different times, and then all of each part is irradiated. (Note 7) The vehicle lighting system according to Note 6, wherein the plurality of parts of the beam are illuminated sequentially from the side closest to the vehicle, or illuminated sequentially from the side furthest from the vehicle, until all of each part is illuminated. (Note 8) The vehicle lighting system according to any one of Notes 1 to 4, wherein the beam is illuminated in a time-division manner such that several parts of the plurality of divided parts in a plan view produce apparent motion.(Note 9) The vehicle lighting system according to any one of Notes 1 to 8, wherein the beam's illumination range is variably set according to the position of other vehicles when other vehicles are present around the vehicle. (Note 10) A vehicle lighting system comprising: a headlight with variable light distribution; an object sensor configured to detect objects around the vehicle; and a controller connected to the object sensor and the headlight, respectively, which controls the operation of the headlight based on the detection result by the object sensor, wherein the object sensor detects at least road markings as objects; and the controller controls the headlight to illuminate the front of the vehicle with a first beam that illuminates an area overlapping with the markings in a plan view and a plurality of second beams that are illuminated in a time-division manner to produce apparent motion.

[0090] 1: Controller, 2: Camera, 3: Millimeter-wave radar, 4: LiDAR, 5: Headlight switch, 6: Map data, 7: GPS sensor, 8: Communication unit, 9L: Left headlight, 9R: Right headlight, 11: Illumination state setting unit, 12: Light distribution control unit, 13: Object position acquisition unit, 14: Road surface condition determination unit, 15: Glare detection unit, 21: Camera, 22: Millimeter-wave radar, 23: LiDAR, 51L, 51R: ADB unit, 52L, 52R: Low beam unit, 100: Own vehicle, 110: Lane marking enhancement beam, 120: Low beam

Claims

1. A vehicle lighting system comprising: a headlight with variable light distribution; an object sensor configured to detect objects around the vehicle; and a controller connected to the object sensor and the headlight, respectively, which controls the operation of the headlight based on the detection result by the object sensor, wherein the controller is configured to estimate the position of at least a road marking as the object, and the controller controls the headlight to illuminate the front of the vehicle with a beam that at least a portion of which overlaps with the estimated position of the road marking and has a plan view shape that increases in width as it moves away from the vehicle.

2. The vehicle lighting system according to claim 1, wherein the controller estimates the position of the lane markings not detected by the object sensor based on at least the detection result of the lane markings detected by the object sensor and road data corresponding to the current position of the vehicle.

3. The vehicle lighting system according to claim 1, wherein the plan view shape of the beam has a first outer edge near the lane marking that is substantially parallel to the lane marking, and the distance of the second outer edge farther from the lane marking gradually increases as it moves away from the vehicle.

4. The vehicle lighting system according to claim 3, wherein the first outer edge of the beam is set to be located outside the vehicle relative to the optical axis of the headlight.

5. The vehicle lighting system according to claim 1, wherein the beam is composed of continuously irradiated light.

6. The vehicle lighting system according to claim 1, wherein the beam, when viewed from above, is divided into multiple parts, each of which is illuminated at a different time, until all of the parts are illuminated.

7. The vehicle lighting system according to claim 6, wherein the plurality of portions of the beam are illuminated sequentially from the side closest to the vehicle, or are illuminated sequentially from the side furthest from the vehicle, and then all of the portions are illuminated.

8. The vehicle lighting system according to claim 1, wherein the beam is irradiated in a time-division manner such that several parts of a plurality of divided parts in a plan view produce apparent motion.

9. The vehicle lighting system according to claim 1, wherein the beam's illumination range is variably set according to the position of other vehicles when other vehicles are present in the vicinity of the vehicle.

10. A vehicle lighting system comprising: a headlight with variable light distribution; an object sensor configured to detect objects around the vehicle; and a controller connected to the object sensor and the headlight, respectively, which controls the operation of the headlight based on the detection results of the object sensor, wherein the object sensor detects at least road markings as the objects; and the controller controls the headlight to illuminate the front of the vehicle with a first beam that illuminates an area overlapping with the road markings in a plan view and a plurality of second beams that are illuminated in a time-division manner to produce apparent motion.

Images