Vehicle travel assistance system, lamp control device, and computer program

Abstract

A vehicle travel assistance system 1 comprises an imaging device 2, an imaging control device 4, a low beam unit 6, a lamp control device 12, and a vehicle control device 14. The lamp control device 12 causes the low beam unit 6 to form a low-beam light distribution pattern, and the imaging control device 4 causes the imaging device 2 to capture an image with a first exposure time. When an object is included below a cutoff line in the obtained image IMG, the imaging control device 4 causes the imaging device 2 to capture an image with a longer second exposure time, and the lamp control device 12 causes the low beam unit 6 to decrease the illuminance of at least a part of the low-beam light distribution pattern. When the object in the image IMG obtained thereafter is a target mobile body, at least one control device transmits a travel assistance instruction signal INS.

Description

Vehicle Driving Support System, Lamp Control Device, and Computer Program

[0001] The present invention relates to a vehicle driving support system, a lamp control device, and a computer program.

[0002] Vehicle lamps play an important role in safe driving at night or in tunnels. If the driver's visibility is prioritized and the front of the vehicle is brightly illuminated over a wide range, there is a problem of causing glare to the drivers of preceding vehicles or oncoming vehicles. In contrast, conventional vehicle lamps have reduced the glare given to the drivers of preceding vehicles or the like by forming a light distribution pattern for low beam having a cut-off line (see, for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2012-134091

[0004] In recent years, as a vehicle driving support system, the installation of Autonomous Emergency Braking (AEB, also referred to as a collision damage mitigation brake) in vehicles has been promoted. In AEB, a target moving object such as a pedestrian who may collide with the vehicle is detected by an imaging device mounted on the vehicle. Then, when the target moving object is detected, the brakes are automatically applied. As a result of intensive studies on the detection of the target moving object by the imaging device, the present inventors have found that there is room for improving the detection accuracy of the target moving object under the formation of the light distribution pattern for low beam, and that the performance of the vehicle driving support system can be improved by improving the detection accuracy.

[0005] The present invention has been made in view of such circumstances, and one of its objects is to provide a technique for improving the performance of a vehicle driving support system.

[0006] 1. In order to solve the above problems, one aspect of the present invention is a vehicle driving support system. This vehicle driving support system comprises an imaging device that repeatedly images the area in front of the vehicle at a predetermined period; an imaging control device that controls the imaging by the imaging device; a low beam unit that can form a low beam light distribution pattern having a cutoff line and can change the illuminance of at least a portion below the cutoff line in the low beam light distribution pattern; a lighting control device that controls the light irradiation of the low beam unit; and a vehicle control device that controls the vehicle. The lighting control device controls the low beam unit to form a low beam light distribution pattern, the imaging control device controls the imaging device to take images for a first exposure time while the low beam light distribution pattern is being formed, and when an object is included in the area below the cutoff line in the image taken while the low beam light distribution pattern is being formed, the imaging control device controls the imaging device to take images for a second exposure time longer than the first exposure time, the lighting control device controls the low beam unit to reduce the illuminance of at least a portion of the area containing the object in the low beam light distribution pattern, and when the object included in the image taken under reduced illuminance conditions is a predetermined moving object, at least one of the vehicle control device, imaging control device, and lighting control device transmits a driving support instruction signal.

[0007] Another aspect of the present invention is a lighting device that controls the light irradiation of a low-beam unit capable of forming a low-beam light distribution pattern having a cutoff line, and capable of changing the illuminance of at least a portion of the area below the cutoff line in the low-beam light distribution pattern. This lighting device controls the low-beam unit to form a low-beam light distribution pattern, and when an object is included in the area below the cutoff line in an image captured by an imaging device, it controls the low-beam unit to reduce the illuminance of at least a portion of the area in the low-beam light distribution pattern that includes the object.

[0008] Another aspect of the present invention is a computer program executed by a lighting device control system that controls the light irradiation of a low beam unit capable of forming a low beam light distribution pattern having a cutoff line and changing the illuminance of at least a portion below the cutoff line in the low beam light distribution pattern. This computer program controls the low beam unit to form a low beam light distribution pattern and causes the lighting device control system to execute a function to control the low beam unit to reduce the illuminance of at least a portion of the area in the low beam light distribution pattern that contains an object when an object is included in the area below the cutoff line in an image captured by an imaging device.

[0009] 2. In order to solve the above problems, one aspect of the present invention is a vehicle driving support system. This vehicle driving support system comprises an imaging device that repeatedly images the area in front of the vehicle at a predetermined period, an imaging control device that controls imaging by the imaging device, a low beam unit capable of forming a low beam light distribution pattern having a cutoff line, an additional unit capable of forming an additional light distribution pattern in a region above the cutoff line, a lighting device control device that controls the light irradiation of the low beam unit and the additional unit, and a vehicle control device that controls the vehicle. The lighting device control controls the low beam unit to form a low beam light distribution pattern, the imaging control device controls the imaging device to repeatedly take images under the formation of the low beam light distribution pattern, and when an object is included in the region below the cutoff line in the image taken under the formation of the low beam light distribution pattern, the lighting device control device controls the additional unit to form an additional light distribution pattern in at least the region above the object, and when the object included in the image taken under the formation of the low beam light distribution pattern and the additional light distribution pattern is a predetermined moving object, at least one of the vehicle control device, imaging control device, and lighting device control device transmits a driving support instruction signal.

[0010] Another aspect of the present invention is a lighting device that controls the light irradiation of a low-beam unit capable of forming a low-beam light distribution pattern having a cutoff line, and the light irradiation of an additional unit capable of forming an additional light distribution pattern in a region above the cutoff line. This lighting device controls the low-beam unit to form a low-beam light distribution pattern, and when an object is included in a region below the cutoff line in an image captured by an imaging device, it controls the additional unit to form an additional light distribution pattern in at least a region above the object.

[0011] Another aspect of the present invention is a computer program executed by a luminaire control device that controls the light irradiation of a low-beam unit capable of forming a low-beam light distribution pattern having a cutoff line, and the light irradiation of an additional unit capable of forming an additional light distribution pattern in a region above the cutoff line. This computer program controls the low-beam unit to form a low-beam light distribution pattern, and also causes the luminaire control device to execute a function that controls the additional unit to form an additional light distribution pattern in at least the region above the object when an object is included in a region below the cutoff line in an image captured by an imaging device.

[0012] Furthermore, any combination of the above components, as well as conversions of the expression of the present invention between methods, apparatus, systems, etc., are also valid embodiments of the present invention.

[0013] According to the present invention, the performance of the vehicle driving support system can be improved.

[0014] This figure shows the schematic configuration of the vehicle driving support system according to Embodiments 1 and 2. This is a schematic diagram showing the light distribution pattern that each unit can form. Figures 3(A), 3(B), and 3(C) are schematic diagrams illustrating an example of the operation performed by the vehicle driving support system. This is a timing chart illustrating an example of the operation performed by the vehicle driving support system. This is a flowchart illustrating an example of the operation of the vehicle driving support system. This figure shows the schematic diagram showing the light distribution pattern that each unit can form. Figures 7(A), 7(B), and 7(C) are schematic diagrams illustrating an example of the operation performed by the vehicle driving support system. This is a timing chart illustrating an example of the operation performed by the vehicle driving support system. This is a flowchart illustrating an example of the operation of the vehicle driving support system.

[0015] The present invention will be described below with reference to the drawings, based on preferred embodiments. The embodiments are illustrative and not limiting, and not all features or combinations thereof described in the embodiments are necessarily essential to the invention. The same or equivalent components, members, and processes shown in each drawing are denoted by the same reference numerals, and redundant explanations are omitted as appropriate. Furthermore, the scale and shape of each part shown in each figure are set for convenience to facilitate explanation and are not to be interpreted restrictively unless otherwise specified. In addition, when terms such as "first," "second," etc. are used in this specification or claims, unless otherwise specified, these terms do not indicate any order or importance, but are used to distinguish one configuration from another. Furthermore, some components that are not important for explaining the embodiments are omitted from the drawings.

[0016] (Embodiment 1) Figure 1 is a diagram showing the schematic configuration of a vehicle driving support system 1 according to Embodiment 1. In Figure 1, at least a part of the components of the vehicle driving support system 1 are depicted as functional blocks. These functional blocks are realized in hardware configuration by elements and circuits such as the CPU and memory of a computer, and in software configuration by computer programs, etc. It will be understood by those skilled in the art that these functional blocks can be realized in various forms by combinations of hardware and software.

[0017] As an example, the vehicle driving support system 1 of this embodiment mainly comprises an imaging device 2, an imaging control device 4, a low beam unit 6, a high beam unit 10, a lighting device control device 12, a vehicle control device 14, and a notification device 16.

[0018] The imaging device 2 is, for example, an in-vehicle camera, which is sensitive to the visible light region and repeatedly captures images of the area in front of the vehicle at predetermined intervals. The imaging device 2 captures visible light that is illuminated by the low-beam unit 6 and the high-beam unit 10 and reflected by objects in front of the vehicle. The imaging device 2 also captures light emitted by vehicles in front, including preceding and oncoming vehicles, as well as light emitted by self-illuminating objects such as streetlights and electronic billboards.

[0019] The image IMG generated by the imaging device 2 is sent to the image control device 4. The image IMG acquired by the image control device 4 from the imaging device 2 may be RAW image data or image data that has undergone predetermined image processing by the imaging device 2. The image control device 4 controls the imaging performed by the imaging device 2. For example, the image control device 4 is composed of a camera ECU (Electronic Control Unit) and can be housed in the same enclosure as the imaging device 2. Alternatively, the image control device 4 can be composed of a digital processor, for example, a combination of a microcontroller including a CPU (Central Processing Unit) and a software program. The image control device 4 may also be composed of an FPGA (Field Programmable Gate Array) or an ASIC (Application Specified IC).

[0020] The low-beam unit 6 and the high-beam unit 10 can each irradiate visible light in front of the vehicle to form a specific light distribution pattern. Figure 2 is a schematic diagram showing the light distribution patterns that each unit can form. The light distribution pattern is understood as the two-dimensional illuminance distribution of the irradiation pattern that each unit forms on a virtual vertical screen 900 in front of the vehicle.

[0021] The low beam unit 6 is capable of forming a low beam light distribution pattern LP having a cutoff line CL. Furthermore, the low beam unit 6 can change the illuminance of at least a portion below the cutoff line CL in the low beam light distribution pattern LP. As an example, the low beam light distribution pattern LP is composed of a diffusion pattern L1, a focusing pattern L2, and an overhead sign light distribution pattern OHS. The low beam unit 6 has a diffusion pattern forming section 18 for forming the diffusion pattern L1, a focusing pattern forming section 20 for forming the focusing pattern L2, and an overhead sign forming section 21 for forming the overhead sign light distribution pattern OHS.

[0022] For example, the diffusion pattern L1 extends in the vehicle width direction at a predetermined distance below the H-H line, forming the base of the low beam light distribution pattern LP. For example, the diffusion pattern L1 extends further outward in the vehicle width direction than the focusing pattern L2, the overhead sign light distribution pattern OHS, and the high beam light distribution pattern HP.

[0023] As an example, the focusing pattern L2 extends in part between the H-H line and the upper end of the diffusion pattern L1, while the other part overlaps with the diffusion pattern L1. The focusing pattern L2 has a cutoff line CL at its upper end. Figure 2 illustrates a cutoff line CL for right-hand traffic as an example. The cutoff line CL consists of a driving lane side cutoff line that overlaps with the H-H line to the right of the V-V line, an oncoming lane side cutoff line that extends parallel to the H line to the left of the V-V line and at a lower position than the driving lane side cutoff line, and a diagonal cutoff line connecting the driving lane side cutoff line and the oncoming lane side cutoff line. The oncoming lane side cutoff line overlaps with the upper end of the diffusion pattern L1.

[0024] For example, the overhead sign light distribution pattern OHS has its lower end overlapping with the H-H line and extends above the cutoff line CL and beyond the concentrating pattern L2 in the vehicle width direction. The illuminance of the overhead sign light distribution pattern OHS is lower than that of the diffusion pattern L1 and the concentrating pattern L2. For example, the luminous intensity of the light forming the diffusion pattern L1 is 500 cd to 20000 cd, and the luminous intensity of the light forming the concentrating pattern L2 is 10000 cd to 50000 cd, while the luminous intensity of the light forming the overhead sign light distribution pattern OHS is approximately 60 cd to 2700 cd.

[0025] The high beam unit 10 can form a high beam light distribution pattern HP in the region above the cutoff line CL. For example, the lower end of the high beam light distribution pattern HP overlaps with the upper end of the diffusion pattern L1 and extends above the H-H line. In this embodiment, the formation range of the high beam light distribution pattern HP is wider than the formation range of the overhead sign light distribution pattern OHS, and the high beam light distribution pattern HP encompasses the entire overhead sign light distribution pattern OHS.

[0026] Each unit of the low beam unit 6 and the high beam unit 10, as well as each forming section of the diffusion pattern forming section 18, the focusing pattern forming section 20, and the overhead sign forming section 21, can employ various known luminaire structures, as long as they can form their respective light distribution patterns. Examples of luminaire structures include those having a reflective optical system such as a reflector, those having a transmissive optical system such as a projection lens, those having multiple light sources arranged in a matrix, those having a matrix-type pattern forming device such as a DMD (Digital Mirror Device) or liquid crystal device, and those having a scanning optical type pattern forming device that scans the area in front of the vehicle with light from a light source. In addition, each unit is housed in the same lamp chamber as an example, but the configuration is not limited to this and they may be housed in separate lamp chambers. Furthermore, each unit and each forming section may be physically independent of each other, or they may share parts of their structure, for example, each light source may be mounted on a single substrate, or the light from each light source may pass through a single projection lens.

[0027] The light source mounted on each unit may be a semiconductor light source such as an LED (light-emitting diode), LD (laser diode), or organic or inorganic EL (electroluminescence), or it may be an incandescent bulb, halogen lamp, discharge bulb, etc. The cutoff line CL can be formed by known methods. For example, the cutoff line CL may be formed by a shade that partially blocks the light emitted by the light source of the light-gathering pattern forming unit 20, or it may be formed by turning off some of the light sources among a plurality of light sources arranged in a matrix.

[0028] The lighting control device 12 controls the light irradiation of the low beam unit 6 and the high beam unit 10. For example, the lighting control device 12 is composed of a lamp ECU and can be housed in the same lighting compartment as each unit. Alternatively, the lighting control device 12 can be composed of a digital processor, for example, a combination of a microcontroller including a CPU and a software program. The lighting control device 12 may also be composed of an FPGA or ASIC. The lighting control device 12 includes a control unit 22 composed of a CPU or the like, and a storage medium 24 composed of memory or storage. The storage medium 24 stores computer programs, etc., that are executed by the lighting control device 12, or more specifically, the control unit 22. The control unit 22 operates by having its constituent integrated circuits execute the programs held in the storage medium 24. Although not shown in the figures, the imaging control device 4 and the vehicle control device 14 also have a control unit and a storage medium, similar to the lighting control device 12.

[0029] The vehicle control device 14 controls various operations of the vehicle. For example, the vehicle control device 14 is composed of a vehicle ECU (also called an on-board ECU) and is mounted on the vehicle body. The vehicle control device 14 can be composed of a digital processor, for example, a combination of a microcontroller including a CPU and a software program. The vehicle control device 14 may also be composed of an FPGA or ASIC. The vehicle control device 14 issues various instructions to the brake system 26, steering system 28, notification system 16, etc., which are mounted on the vehicle. The vehicle control device 14 can also receive the vehicle speed signal SPD transmitted by the vehicle speed sensor 30, which detects the vehicle speed.

[0030] The braking device 26 performs the braking action. The steering device 28 performs the steering operation. The notification device 16 can notify the driver of the vehicle of the presence of a moving object, which will be described later. The notification method is not particularly limited, and known methods such as auditory notification methods, such as the generation of a notification sound, or visual notification methods, such as the illumination of a notification light, can be adopted.

[0031] Next, we will explain the operations performed by the vehicle driving support system 1 under the formation of the low beam light distribution pattern LP. Figures 3(A), 3(B), and 3(C) are schematic diagrams illustrating an example of the operations performed by the vehicle driving support system 1. Figure 4 is a timing chart illustrating an example of the operations performed by the vehicle driving support system 1. Figures 3(A) to 3(C) schematically show the view in front of the vehicle as observed by the imaging device 2, in other words, the image IMG captured by the imaging device 2. The upper part of Figure 4 shows the change in exposure amount of the imaging device 2, and the lower part of Figure 4 shows the change in illuminance of the focusing pattern L2.

[0032] First, the lighting control device 12 controls the low beam unit 6 to form a low beam light distribution pattern LP. As a result, as shown in Figure 3(A), a low beam light distribution pattern LP, which includes a diffusion pattern L1, a focusing pattern L2, and an overhead sign light distribution pattern OHS, is formed in front of the vehicle. The imaging control device 4 controls the imaging device 2 to take an image at a first exposure time T1 while the low beam light distribution pattern LP is being formed. The imaging device 2 repeats the imaging, for example, at a period of 33 ms.

[0033] Assume that in the image IMG captured at a first exposure time T1 while the low beam light distribution pattern LP is being formed, object X is included in the region below the cutoff line CL. In this case, the imaging control device 4 controls the imaging device 2 to take images at a second exposure time T2 which is longer than the first exposure time T1. The lighting control device 12 also controls the low beam unit 6 to reduce the illuminance of at least a portion of the region containing object X in the low beam light distribution pattern LP.

[0034] As an example, the lighting control device 12 controls the low beam unit 6 to reduce the illuminance of the focusing pattern L2 as at least a part of the low beam light distribution pattern LP, as shown in Figure 3(B). As a result, under conditions where the illuminance of the focusing pattern L2 is reduced, the area in front of the vehicle is imaged at the second exposure time T2, and an image IMG is generated. The amount of illuminance reduction, the first exposure time T1, and the second exposure time T2 can be set as appropriate based on the designer's empirical knowledge or experiments and simulations conducted by the designer.

[0035] The detection of object X can be performed, for example, by the imaging control device 4 using a known method. When the imaging control device 4 detects object X, it controls the imaging device 2 to change its exposure time to a second exposure time T2, and also transmits a signal to the lighting control device 12 via the vehicle control device 14 indicating the presence of object X. The imaging control device 4 and the lighting control device 12 may communicate directly with each other. When the lighting control device 12 receives the signal, it controls the low beam unit 6 to reduce the illuminance of the focusing pattern L2. In the example shown in Figure 4, object X is detected at time Ta.

[0036] Alternatively, an image IMG may be sent from the imaging control device 4 to the vehicle control device 14, and the vehicle control device 14 may detect object X. In this case, when the vehicle control device 14 detects object X, it sends a signal to both the imaging control device 4 and the lighting control device 12 indicating the presence of object X. Note that if the imaging control device 4 detects object X, it is possible to avoid control delays caused by sending an image IMG from the camera ECU to the vehicle ECU.

[0037] Under the formation of the low-beam light distribution pattern LP, the regions where the diffusion pattern L1 and the focusing pattern L2 are formed are bright enough for imaging due to these patterns. Therefore, if an object X exists in that region, the object X will be clearly captured in the image IMG to the extent that its presence and shape can be determined. On the other hand, the overhead sign light distribution pattern OHS has a lower illuminance than the diffusion pattern L1 and the focusing pattern L2. Therefore, even if the object X extends above the cutoff line CL, the portion above the cutoff line CL is unlikely to be captured in the image IMG to the extent that its presence and shape can be determined.

[0038] Therefore, when the imaging control device 4 and the vehicle control device 14 apply target detection processing to the image IMG captured at the first exposure time T1 under the formation of the low beam light distribution pattern LP, they can detect the portion of object X below the cutoff line CL, but they cannot grasp the entire object X, making it difficult to determine whether or not object X is a predetermined target moving object. A target moving object is a moving object such as a pedestrian, bicycle, or animal that is expected to interfere with the vehicle's movement, in other words, a moving object for which vehicle driving assistance is desired.

[0039] In response to this, one might consider extending the exposure time of the imaging device 2 so that the area above the cutoff line CL can be clearly imaged. However, in this case, there is a risk that so-called "blown-out" highlights will occur in the area below the cutoff line CL. Blurred highlights are a phenomenon in which an area is completely whited out because the maximum amount of light that the imaging device 2 can capture is exceeded. If blurred highlights occur in the area below the cutoff line CL, even if the part of object X above the cutoff line CL can be detected, it is ultimately impossible to grasp the entire object X, and it remains difficult to determine whether or not object X is a predetermined moving object.

[0040] Therefore, in the vehicle driving support system 1 of this embodiment, the exposure time is extended, and the illuminance of at least a portion of the area including object X in the low beam light distribution pattern LP, for example, the focusing pattern L2, is reduced. As a result, the illuminance of the focusing pattern L2 approaches that of the overhead sign light distribution pattern OHS. In other words, for at least the area including object X, the illuminance of the light illuminating below the cutoff line CL and the illuminance of the light illuminating above the cutoff line CL become closer. Thus, it becomes easier to clearly image the entire object X.

[0041] Therefore, the imaging control device 4 or the vehicle control device 14 can more accurately determine whether the object X is a predetermined target moving object by performing known target detection processing on the image IMG captured at the second exposure time T2 under the situation where the illuminance of the light collection pattern L2 is reduced. The target detection processing includes, for example, predetermined image processing, algorithm recognition, deep learning, and the like.

[0042] For example, when the imaging control device 4 determines whether it is a target moving object, if the imaging control device 4 determines that the object X is a target moving object, it transmits a signal indicating the presence of the target moving object to the vehicle control device 14. In addition, the imaging control device 4 or the vehicle control device 14 transmits the signal to the lamp control device 12 as necessary. Alternatively, the image IMG may be sent from the imaging control device 4 to the vehicle control device 14, and the vehicle control device 14 may determine whether it is a target moving object. In this case, when the vehicle control device 14 determines that the object X is a target moving object, it transmits a signal indicating the presence of the target moving object to each of the imaging control device 4 and the lamp control device 12 as necessary. When the imaging control device 4 determines the target moving object, it is possible to avoid the control delay caused by sending the image IMG from the camera ECU to the vehicle ECU. In addition, the lamp control device 12 may also determine the presence or absence of the object X or the target moving object.

[0043] When the object X included in the image IMG is a target moving object, at least one of the vehicle control device 14, the imaging control device 4, and the lamp control device 12 transmits a predetermined driving support instruction signal INS. As an example, the driving support instruction signal INS includes at least one of a brake instruction signal for the brake device 26, a steering instruction signal for the steering device 28, and a passing instruction signal for at least one of the low beam unit 6 and the high beam unit 10. In addition, since the vehicle driving support system 1 of the present embodiment includes the notification device 16, the driving support instruction signal INS may be a notification instruction signal for the notification device 16.

[0044] For example, if a target moving object is present in front of the vehicle, a brake instruction signal is transmitted from the vehicle control device 14 to the brake device 26. Upon receiving the brake instruction signal, the brake device 26 performs a braking action. This enables automatic emergency braking. Also, if a target moving object is present in front of the vehicle, a steering instruction signal is transmitted from the vehicle control device 14 to the steering device 28. Upon receiving the steering instruction signal, the steering device 28 performs a steering operation. This helps to avoid the vehicle colliding with the target moving object. Furthermore, if a target moving object is present in front of the vehicle, a notification instruction signal is transmitted from the vehicle control device 14 to the notification device 16. Upon receiving the notification instruction signal, the notification device 16 performs a notification action. This allows the driver to be notified of the presence of the target moving object.

[0045] Furthermore, if a target moving object is present in front of the vehicle, a passing instruction signal is transmitted from the lighting control device 12 to at least one of the low beam unit 6 and the high beam unit 10. Upon receiving the passing instruction signal, the low beam unit 6 repeatedly increases or decreases the illuminance of at least a portion of the low beam light distribution pattern LP to perform a passing flash. Upon receiving the passing instruction signal, the high beam unit 10 repeatedly increases or decreases the illuminance of at least a portion of the high beam light distribution pattern HP to perform a passing flash. This allows the presence of the vehicle to be communicated to the target moving object. Braking, steering, notification, and passing operations may be performed individually or in combination of two or more. In addition, the driving support instruction signal INS that instructs each operation may be transmitted by the imaging control device 4.

[0046] When at least one of the braking operation by the braking device 26, the steering operation by the steering device 28, the passing by at least one of the low beam unit 6 and the high beam unit 10, and the notification operation by the notification device 16 is executed, the lamp control device 12 controls the low beam unit 6 to increase the reduced illuminance of the low beam light distribution pattern LP. For example, the lamp control device 12 controls the low beam unit 6 so as to restore the illuminance of the condensing pattern L2. Thereby, it is possible to avoid that the state in which the visibility in front of the host vehicle is reduced due to the reduction of the illuminance of the condensing pattern L2 continues uselessly.

[0047] For example, the braking device 26 transmits a signal indicating that the braking operation has been executed to the lamp control device 12. The steering device 28 transmits a signal indicating that the steering operation has been executed to the lamp control device 12. The low beam unit 6 and the high beam unit 10 transmit a signal indicating that the passing has been executed to the lamp control device 12. The notification device 16 transmits a signal indicating that the notification operation has been executed to the lamp control device 12. When receiving these signals, the lamp control device 12 restores the illuminance of the condensing pattern L2 as shown in FIG. 3(C). In the example shown in FIG. 4, the lamp control device 12 receives these signals at time Tb.

[0048] When the lamp control device 12 restores the illuminance of the condensing pattern L2, it transmits a signal indicating that the normal low beam light distribution pattern LP has been formed to the imaging control device 4. When receiving the signal, the imaging control device 4 controls the imaging device 2 to perform imaging with the first exposure time T1. Note that the braking device 26, the steering device 28, the low beam unit 6, the high beam unit 10, and the notification device 16 may transmit a signal indicating that each operation has been executed to the imaging control device 4. Also in this aspect, the imaging control device 4 can grasp the timing for instructing the change from the second exposure time T2 to the first exposure time T1.

[0049] Furthermore, the driving support instruction signal INS may include a brake instruction signal for the brake device 26 and a notification instruction signal for the notification device 16. A notification instruction signal may be transmitted when the vehicle speed detected by the vehicle speed sensor 30 is below a predetermined value, and a brake instruction signal may be transmitted when the vehicle speed exceeds the predetermined value. The predetermined value can be appropriately set based on the designer's empirical knowledge or experiments and simulations conducted by the designer.

[0050] This control system allows the driver to be notified of the presence of a target object and to perform braking or steering actions when the vehicle speed is below a predetermined value and it is expected that the time it will take for the vehicle to reach the target object will be relatively long. Conversely, if the vehicle speed is above a predetermined value and it is expected that the time it will take for the vehicle to reach the target object will be relatively short, automatic emergency braking can be applied. If the vehicle is equipped with a distance measuring sensor such as millimeter-wave radar or LiDAR, the distance from the vehicle to the target object may be used in addition to the vehicle speed to determine whether to send a notification signal or a brake signal. For example, the time it will take to reach the target object may be calculated from the vehicle speed and distance, and a notification signal may be sent when the time it takes to reach the target object exceeds a predetermined value, and a brake signal may be sent when the time it takes to reach the target object is below the predetermined value.

[0051] Furthermore, the vehicle driving support system 1 may include an additional unit capable of forming an additional light distribution pattern AP in the region above the cutoff line CL. The lighting control device 12 may control the low beam unit 6 to reduce the illuminance of at least a portion of the region including object X, and may also control the additional unit to form the additional light distribution pattern AP. This makes it possible to create a situation in which the entire object X can be clearly imaged while suppressing the reduction in the illuminance of the focusing pattern L2. Thus, it is possible to improve the detection accuracy of the moving target while suppressing a decrease in visibility in front of the vehicle. The amount of reduction in the illuminance of the focusing pattern L2 can be determined according to the illuminance of the additional light distribution pattern AP. The second exposure time T2 can also be determined according to the illuminance of the focusing pattern L2 after reduction and the illuminance of the additional light distribution pattern AP.

[0052] In this embodiment, the overhead sign light distribution pattern OHS can be interpreted as functioning as an additional light distribution pattern AP. In other words, the overhead sign forming unit 21 can be interpreted as functioning as an additional unit. When using the overhead sign light distribution pattern OHS as an additional light distribution pattern AP, the illuminance of the overhead sign light distribution pattern OHS may be increased as needed before using it as an additional light distribution pattern AP. The vehicle driving support system 1 may also be equipped with a dedicated lighting unit for forming the additional light distribution pattern AP. Furthermore, the additional light distribution pattern AP may be formed locally in a region that includes the portion of object X above the cutoff line CL.

[0053] This embodiment includes a computer program executed by the lighting control device 12. This computer program controls the low beam unit 6 to form a low beam light distribution pattern LP, and also causes the lighting control device 12 to execute a function to control the low beam unit 6 to reduce the illuminance of at least a portion of the area containing object X in the low beam light distribution pattern LP when object X is included in the area below the cutoff line CL in the image IMG captured by the imaging device 2. This embodiment also includes a storage medium 24 on which the computer program is stored.

[0054] Figure 5 is a flowchart illustrating an example of the operation of the vehicle driving support system 1. This flow is executed repeatedly, for example, at predetermined timings. First, a low beam light distribution pattern LP is formed (S101). Also, the area in front of the vehicle is imaged by the imaging device 2 for a first exposure time T1 (S102). Then, it is determined whether an object X exists in the region below the cutoff line CL in the image IMG (S103). If no object X exists (N in S103), this routine ends.

[0055] If object X is present (Y in S103), the illuminance of the focusing pattern L2 is reduced, for example (S104). Also, the area in front of the vehicle is imaged by the imaging device 2 for a second exposure time T2 (S105). Then, it is determined whether object X is the target moving object based on the obtained image IMG (S106). If object X is not the target moving object (N in S106), this routine ends. If object X is the target moving object (Y in S106), a driving support instruction signal is transmitted (S107).

[0056] Next, it is determined whether driving assistance has been implemented (S108). Whether or not driving assistance has been implemented can be determined based on whether or not a signal indicating operation has been received from at least one of the brake device 26, steering device 28, low beam unit 6, and notification device 16. If driving assistance has not been implemented (N in S108), the determination in step S108 is repeated. If driving assistance has been implemented (Y in S108), the illuminance of the focusing pattern L2 is restored, the exposure time is changed to the first exposure time T1 (S109), and this routine ends.

[0057] As described above, the vehicle driving support system 1 according to this embodiment, when an object X is included in the region below the cutoff line CL in the image IMG captured under the formation of the low beam light distribution pattern LP, reduces the illuminance of at least a part of the region containing object X in the low beam light distribution pattern LP and extends the exposure time for imaging, and determines whether or not object X is a target moving object based on the image obtained thereby. When the object is a predetermined target moving object, it transmits a driving support instruction signal. This makes it possible to improve the detection accuracy of target moving objects under the formation of the low beam light distribution pattern LP and improve the performance of the vehicle driving support system 1.

[0058] Furthermore, in this embodiment, the illuminance of the focusing pattern L2 is reduced as part of the low-beam light distribution pattern LP. By reducing the illuminance of only the focusing pattern L2 while maintaining the illuminance of the diffusion pattern L1, it is possible to suppress an excessive decrease in visibility below the H-H line. The luminaire control device 12 may also make the focusing pattern L2 disappear. In other words, the illuminance of the focusing pattern L2 may be set to 0. When the focusing pattern L2 is made disappear, control can be simplified compared to when the formation of the focusing pattern L2 is maintained while reducing its illuminance. Also, if the focusing pattern forming unit 20 has a structure that can partially increase or decrease the illuminance of the focusing pattern L2, only the illuminance of the part of the focusing pattern L2 that overlaps with object X may be reduced. Furthermore, the illuminance of the diffusion pattern L1 may be reduced as needed.

[0059] Embodiment 1 of the present invention has been described in detail above. Embodiment 1 described above is merely a specific example of how to implement the present invention. The content of the embodiment does not limit the technical scope of the present invention, and many design changes such as changes, additions, and deletions of components are possible as long as they do not depart from the spirit of the invention as defined in the claims. A new embodiment with design changes will have the effects of both the combined embodiment and the modification. In the embodiments described above, the content in which such design changes are possible is emphasized with notations such as "in this embodiment" or "in this embodiment," but design changes are also permitted even if there are no such notations. Any combination of the above components is also valid as an embodiment of the present invention. The hatching applied to the cross-section in the drawing does not limit the material of the object to which the hatching is applied.

[0060] (Modification) In Embodiment 1, the imaging control device 4 is composed of a camera ECU, the lighting control device 12 is composed of a lamp ECU, and the vehicle control device 14 is composed of a vehicle ECU. However, the configuration of each control device is not limited to this. For example, an ECU that functions as any of the control devices may function as all or part of the other control devices.

[0061] For example, instead of a camera ECU, a simple control circuit that controls the imaging timing and exposure time of the imaging device 2 may be mounted on the imaging device 2. In this case, for example, the image IMG is sent from the imaging device 2 to the vehicle ECU, which then performs object X detection and target moving object determination. In other words, the vehicle ECU functions not only as a vehicle control device 14 but also as an imaging control device 4. The vehicle ECU then sends a signal to the control circuit of the imaging device 2 that triggers a change in exposure time. The vehicle ECU also sends a signal to the lighting control device 12 that triggers a change in illuminance. Alternatively, the vehicle ECU may directly control the exposure time.

[0062] Alternatively, instead of a lamp ECU, a simple lighting circuit such as an LDM (LED Driving Module) may be installed in the low beam unit 6 or the high beam unit 10. In this case, for example, the vehicle ECU controls the light illumination of the low beam unit 6 and the high beam unit 10. In other words, the vehicle ECU functions not only as a vehicle control device 14 but also as a lighting device control device 12. The vehicle ECU then transmits a signal to the lighting circuit of the low beam unit 6 to instruct a change in the illuminance of the low beam light distribution pattern LP, or transmits a passing instruction signal, etc., to the lighting circuit of at least one of the low beam unit 6 and the high beam unit 10.

[0063] Alternatively, a simple control circuit may be mounted on the imaging device 2 instead of the camera ECU, and a simple lighting circuit may be mounted on the low beam unit 6 or high beam unit 10 instead of the lamp ECU. In this case, the vehicle ECU functions not only as the vehicle control device 14 but also as the imaging control device 4 and the lighting device control device 12.

[0064] The invention according to Embodiment 1 described above may be specified by the following items. [Item 1] An imaging device (2) that repeatedly images the area in front of a vehicle at a predetermined period; an imaging control device (4) that controls imaging by the imaging device (2); a low beam unit (6) that can form a low beam light distribution pattern (LP) having a cutoff line (CL) and can change the illuminance of at least a portion below the cutoff line (CL) in the low beam light distribution pattern (LP); a lighting device control device (12) that controls the light irradiation of the low beam unit (6); and a vehicle control device (14) that controls the vehicle, wherein the lighting device control device (12) controls the low beam unit (6) to form a low beam light distribution pattern (LP), and the imaging control device (4) controls the imaging device (2) to take images at a first exposure time (T1) under the formation of the low beam light distribution pattern (LP). A vehicle driving support system (1) wherein, when an object (X) is included in an area below the cutoff line (CL) in an image (IMG) captured under the formation of a low beam light distribution pattern (LP), the imaging control device (4) controls the imaging device (2) to capture an image with a second exposure time (T2) longer than a first exposure time (T1), and the lighting control device (12) controls the low beam unit (6) to reduce the illuminance of at least a portion of the area containing the object (X) in the low beam light distribution pattern (LP), and when the object (X) included in the image (IMG) captured under reduced illuminance conditions is a predetermined moving object, at least one of the vehicle control device (14), imaging control device (4), and lighting control device (12) transmits a driving support instruction signal (INS). [Item 2] The vehicle driving support system (1) comprises a high beam unit (10) capable of forming a high beam light distribution pattern (HP), and the driving support instruction signal (INS) includes at least one of a brake instruction signal to a brake device (26) mounted on the vehicle, a steering instruction signal to a steering device (28) mounted on the vehicle, and a passing instruction signal to at least one of the low beam unit (6) and the high beam unit (10), as per Item 1.[Item 3] The vehicle driving support system (1) according to Item 2, wherein the lighting control device (6) controls the low beam unit (6) to increase the reduced illuminance of the low beam light distribution pattern (LP) when at least one of the following is performed: braking by the brake device (26), steering by the steering device (28), and flashing by at least one of the low beam unit (6) and the high beam unit (10). [Item 4] The vehicle driving support system (1) comprises a notification device (16) mounted on the vehicle that notifies the driver of the presence of a target moving object, and the driving support instruction signal (INS) includes a brake instruction signal to the brake device (26) mounted on the vehicle and a notification instruction signal to the notification device (16), wherein the notification instruction signal is transmitted when the vehicle speed is below a predetermined value, and the brake instruction signal is transmitted when the vehicle speed exceeds a predetermined value. [Item 5] A vehicle driving support system (1) comprising an additional unit capable of forming an additional light distribution pattern (AP) in an area above the cutoff line (CL), and a lighting control device (12) controlling the low beam unit (LP) to reduce the illuminance of at least a portion of the area including the object (X), and controlling the additional unit to form an additional light distribution pattern (AP), the vehicle driving support system (1) according to any one of items 1 to 4. [Item 6] A lighting device (12) that controls the light irradiation of a low beam unit (6) capable of forming a low beam light distribution pattern (LP) having a cutoff line (CL) and capable of changing the illuminance of at least a portion below the cutoff line (CL) in the low beam light distribution pattern (LP), wherein the lighting device (12) controls the low beam unit (6) to form a low beam light distribution pattern (LP), and when an object (X) is included in the region below the cutoff line (CL) in an image (IMG) captured by an imaging device (2), controls the low beam unit (6) to reduce the illuminance of at least a portion of the region in the low beam light distribution pattern (LP) that includes the object (X).[Item 7] A computer program executed by a lighting device control device (12) that controls the light irradiation of a low beam unit (6) capable of forming a low beam light distribution pattern (LP) having a cutoff line (CL) and capable of changing the illuminance of at least a portion below the cutoff line (CL) in the low beam light distribution pattern (LP), wherein the computer program controls the low beam unit (6) to form a low beam light distribution pattern (LP), and when an object (X) is included in the region below the cutoff line (CL) in an image (IMG) captured by an imaging device (2), causes the lighting device control device (12) to execute a function to control the low beam unit (6) to reduce the illuminance of at least a portion of the region in the low beam light distribution pattern (LP) that includes the object (X).

[0065] (Embodiment 2) Figure 1 is a diagram showing the schematic configuration of a vehicle driving support system 1 according to Embodiment 2. In Figure 1, at least a part of the components of the vehicle driving support system 1 are depicted as functional blocks. These functional blocks are realized in hardware configuration by elements and circuits such as the CPU and memory of a computer, and in software configuration by computer programs, etc. It will be understood by those skilled in the art that these functional blocks can be realized in various forms by combinations of hardware and software.

[0066] As an example, the vehicle driving support system 1 of this embodiment mainly comprises an imaging device 2, an imaging control device 4, a low beam unit 6, a high beam unit 10, a lighting device control device 12, a vehicle control device 14, and a notification device 16.

[0067] The imaging device 2 is, for example, an in-vehicle camera, which is sensitive to the visible light region and repeatedly captures images of the area in front of the vehicle at predetermined intervals. The imaging device 2 captures visible light that is illuminated by the low-beam unit 6 and the high-beam unit 10 and reflected by objects in front of the vehicle. The imaging device 2 also captures light emitted by vehicles in front, including preceding and oncoming vehicles, as well as light emitted by self-illuminating objects such as streetlights and electronic billboards.

[0068] The image IMG generated by the imaging device 2 is sent to the image control device 4. The image IMG acquired by the image control device 4 from the imaging device 2 may be RAW image data or image data that has undergone predetermined image processing by the imaging device 2. The image control device 4 controls the imaging performed by the imaging device 2. For example, the image control device 4 is composed of a camera ECU (Electronic Control Unit) and can be housed in the same enclosure as the imaging device 2. Alternatively, the image control device 4 can be composed of a digital processor, for example, a combination of a microcontroller including a CPU (Central Processing Unit) and a software program. The image control device 4 may also be composed of an FPGA (Field Programmable Gate Array) or an ASIC (Application Specified IC).

[0069] The low-beam unit 6 and the high-beam unit 10 can each irradiate visible light in front of the vehicle to form a specific light distribution pattern. Figure 6 is a schematic diagram showing the light distribution patterns that each unit can form. The light distribution pattern is understood as the two-dimensional illuminance distribution of the irradiation pattern that each unit forms on a virtual vertical screen 900 in front of the vehicle.

[0070] The low beam unit 6 is capable of forming a low beam light distribution pattern LP having a cutoff line CL. For example, the low beam light distribution pattern LP consists of a diffusion pattern L1, a focusing pattern L2, and an overhead sign light distribution pattern OHS. The low beam unit 6 has a diffusion pattern forming section 18 for forming the diffusion pattern L1, a focusing pattern forming section 20 for forming the focusing pattern L2, and an overhead sign forming section 21 for forming the overhead sign light distribution pattern OHS.

[0071] For example, the diffusion pattern L1 extends in the vehicle width direction at a predetermined distance below the H-H line, forming the base of the low beam light distribution pattern LP. For example, the diffusion pattern L1 extends further outward in the vehicle width direction than the focusing pattern L2, the overhead sign light distribution pattern OHS, and the high beam light distribution pattern HP.

[0072] As an example, the focusing pattern L2 extends in part between the H-H line and the upper end of the diffusion pattern L1, while the other part overlaps with the diffusion pattern L1. The focusing pattern L2 has a cutoff line CL at its upper end. Figure 6 illustrates an example of a cutoff line CL for right-hand traffic. The cutoff line CL consists of a driving lane side cutoff line that overlaps with the H-H line to the right of the V-V line, an oncoming lane side cutoff line that extends parallel to the H line to the left of the V-V line and at a lower position than the driving lane side cutoff line, and a diagonal cutoff line connecting the driving lane side cutoff line and the oncoming lane side cutoff line. The oncoming lane side cutoff line overlaps with the upper end of the diffusion pattern L1.

[0073] For example, the overhead sign light distribution pattern OHS has its lower end overlapping with the H-H line and extends above the cutoff line CL and beyond the concentrating pattern L2 in the vehicle width direction. The illuminance of the overhead sign light distribution pattern OHS is lower than that of the diffusion pattern L1 and the concentrating pattern L2. For example, the luminous intensity of the light forming the diffusion pattern L1 is 500 cd to 20000 cd, and the luminous intensity of the light forming the concentrating pattern L2 is 10000 cd to 50000 cd, while the luminous intensity of the light forming the overhead sign light distribution pattern OHS is approximately 60 cd to 2700 cd.

[0074] The high beam unit 10 can form a high beam light distribution pattern HP in the region above the cutoff line CL. For example, the lower end of the high beam light distribution pattern HP overlaps with the upper end of the diffusion pattern L1 and extends above the H-H line. In this embodiment, the formation range of the high beam light distribution pattern HP is wider than the formation range of the overhead sign light distribution pattern OHS, and the high beam light distribution pattern HP encompasses the entire overhead sign light distribution pattern OHS.

[0075] Each unit of the low beam unit 6 and the high beam unit 10, as well as each forming section of the diffusion pattern forming section 18, the focusing pattern forming section 20, and the overhead sign forming section 21, can employ various known luminaire structures, as long as they can form their respective light distribution patterns. Examples of luminaire structures include those having a reflective optical system such as a reflector, those having a transmissive optical system such as a projection lens, those having multiple light sources arranged in a matrix, those having a matrix-type pattern forming device such as a DMD (Digital Mirror Device) or liquid crystal device, and those having a scanning optical type pattern forming device that scans the area in front of the vehicle with light from a light source. Furthermore, each unit and each forming section is housed in the same lamp chamber as an example, but the configuration is not limited to this and they may be housed in separate lamp chambers. In addition, each unit and each forming section may be physically independent of each other, or they may share parts of their structure, for example, each light source may be mounted on a single substrate, or the light from each light source may pass through a single projection lens.

[0076] The light source mounted on each unit may be a semiconductor light source such as an LED (light-emitting diode), LD (laser diode), or organic or inorganic EL (electroluminescence), or it may be an incandescent bulb, halogen lamp, discharge bulb, etc. The cutoff line CL can be formed by known methods. For example, the cutoff line CL may be formed by a shade that partially blocks the light emitted by the light source of the light-gathering pattern forming unit 20, or it may be formed by turning off some of the light sources among a plurality of light sources arranged in a matrix.

[0077] The lighting control device 12 controls the light irradiation of the low beam unit 6 and the high beam unit 10. For example, the lighting control device 12 is composed of a lamp ECU and can be housed in the same lighting compartment as each unit. Alternatively, the lighting control device 12 can be composed of a digital processor, for example, a combination of a microcontroller including a CPU and a software program. The lighting control device 12 may also be composed of an FPGA or ASIC. The lighting control device 12 includes a control unit 22 composed of a CPU or the like, and a storage medium 24 composed of memory or storage. The storage medium 24 stores computer programs, etc., that are executed by the lighting control device 12, or more specifically, the control unit 22. The control unit 22 operates by having its constituent integrated circuits execute the programs held in the storage medium 24. Although not shown in the figures, the imaging control device 4 and the vehicle control device 14 also have a control unit and a storage medium, similar to the lighting control device 12.

[0078] The vehicle control device 14 controls various operations of the vehicle. For example, the vehicle control device 14 is composed of a vehicle ECU (also called an on-board ECU) and is mounted on the vehicle body. The vehicle control device 14 can be composed of a digital processor, for example, a combination of a microcontroller including a CPU and a software program. The vehicle control device 14 may also be composed of an FPGA or ASIC. The vehicle control device 14 issues various instructions to the brake system 26, steering system 28, notification system 16, etc., which are mounted on the vehicle. The vehicle control device 14 can also receive the vehicle speed signal SPD transmitted by the vehicle speed sensor 30, which detects the vehicle speed.

[0079] The braking device 26 performs the braking action. The steering device 28 performs the steering operation. The notification device 16 can notify the driver of the vehicle of the presence of a moving object, which will be described later. The notification method is not particularly limited, and known methods such as auditory notification methods, such as the generation of a notification sound, or visual notification methods, such as the illumination of a notification light, can be adopted.

[0080] Next, we will explain the operations performed by the vehicle driving support system 1 under the formation of the low beam light distribution pattern LP. Figures 7(A), 7(B), and 7(C) are schematic diagrams illustrating an example of the operations performed by the vehicle driving support system 1. Figure 8 is a timing chart illustrating an example of the operations performed by the vehicle driving support system 1. Figures 7(A) to 7(C) schematically show the view in front of the vehicle as observed by the imaging device 2, in other words, the image IMG captured by the imaging device 2. The upper part of Figure 8 shows the change in exposure amount of the imaging device 2, and the lower part of Figure 8 shows the change in illuminance of the overhead sign light distribution pattern OHS.

[0081] First, the lighting control device 12 controls the low beam unit 6 to form a low beam light distribution pattern LP. As a result, as shown in Figure 7(A), a low beam light distribution pattern LP, which includes a diffusion pattern L1, a focusing pattern L2, and an overhead sign light distribution pattern OHS, is formed in front of the vehicle. The imaging control device 4 controls the imaging device 2 to repeatedly take images while the low beam light distribution pattern LP is being formed. The imaging device 2 repeats imaging, for example, with a period of 33 ms and a first exposure time T1.

[0082] Assume that in the image IMG captured under the formation of the low beam light distribution pattern LP, object X is included in the region below the cutoff line CL. In this case, the lighting device control unit 12 controls the additional unit to form an additional light distribution pattern AP in the region above the cutoff line CL and at least in the region above object X. In this disclosure, "the region above object X" is the region above the cutoff line CL where the position of object X in the vehicle width direction coincides.

[0083] In this embodiment, as an example, the overhead sign forming unit 21 functions as an additional unit capable of forming an additional light distribution pattern AP. As shown in Figure 7(B), the luminaire control device 12 controls the overhead sign forming unit 21 as an additional unit to form the additional light distribution pattern AP by increasing the illuminance of the overhead sign light distribution pattern OHS. In other words, the additional unit of this embodiment is capable of forming the overhead sign light distribution pattern OHS and is also capable of forming the additional light distribution pattern AP by increasing the illuminance of the overhead sign light distribution pattern OHS. By using the overhead sign forming unit 21 as an additional unit, it is possible to reduce the complexity of the system structure and the increase in costs that would result from adding additional units.

[0084] The vehicle driving support system 1 may also include a dedicated lighting unit for forming the additional light distribution pattern AP. The additional light distribution pattern AP may also be formed locally in the area above the object X. If the overhead sign forming unit 21 has a structure that allows the illuminance of the overhead sign light distribution pattern OHS to be partially changed, the illuminance of only the portion above the object X in the overhead sign light distribution pattern OHS may be increased.

[0085] As a result, the area in front of the vehicle is imaged under conditions where the low-beam light distribution pattern LP and the additional light distribution pattern AP are formed, and an image IMG is generated. The amount of increase in illuminance of the overhead sign light distribution pattern OHS, i.e., the illuminance of the additional light distribution pattern AP, and the first exposure time T1 can be set appropriately based on the designer's empirical knowledge or experiments and simulations conducted by the designer.

[0086] Furthermore, the additional light distribution pattern AP, which is formed by increasing the illuminance of the overhead sign light distribution pattern OHS, can be said to include the overhead sign light distribution pattern OHS. In other words, the illuminance of the additional light distribution pattern AP is ＡＰ This includes the illuminance I of the overhead sign light distribution pattern OHS. ＯＨＳ and the difference in illuminance between the two patterns I ＡＰ-ＯＨＳ This includes and this difference I ＡＰ-ＯＨＳIt can be said that the additional light distribution pattern AP is the overhead sign light distribution pattern OHS that has been added to it. Therefore, the state in which the diffusion pattern L1, the focusing pattern L2, and the additional light distribution pattern AP are formed can be interpreted as the state in which the low beam light distribution pattern LP and the additional light distribution pattern AP are formed.

[0087] The detection of object X can be performed, for example, by the imaging control device 4 using a known method. When the imaging control device 4 detects object X, it transmits a signal to the lighting control device 12 via the vehicle control device 14 indicating the presence of object X. The imaging control device 4 and the lighting control device 12 may communicate directly with each other. Upon receiving the signal, the lighting control device 12 controls the overhead sign forming unit 21 to form an additional light distribution pattern AP. In the example shown in Figure 8, object X is detected at time Ta.

[0088] Alternatively, an image IMG may be sent from the imaging control device 4 to the vehicle control device 14, and object X may be detected by the vehicle control device 14. In this case, when the vehicle control device 14 detects object X, it sends a signal to the lighting control device 12 indicating the presence of object X. Note that if the imaging control device 4 detects object X, control delays caused by sending an image IMG from the camera ECU to the vehicle ECU can be avoided.

[0089] Under the formation of the low-beam light distribution pattern LP, the regions where the diffusion pattern L1 and the focusing pattern L2 are formed are bright enough for imaging due to these patterns. Therefore, if an object X exists in that region, the object X will be clearly captured in the image IMG to the extent that its presence and shape can be determined. On the other hand, the overhead sign light distribution pattern OHS has a lower illuminance than the diffusion pattern L1 and the focusing pattern L2. Therefore, even if the object X extends above the cutoff line CL, the portion above the cutoff line CL is unlikely to be captured in the image IMG to the extent that its presence and shape can be determined.

[0090] Therefore, when the imaging control device 4 and the vehicle control device 14 apply target detection processing to the image IMG captured at the first exposure time T1 under the formation of the low beam light distribution pattern LP, they can detect the portion of object X below the cutoff line CL, but they cannot grasp the entire object X, making it difficult to determine whether or not object X is a predetermined target moving object. A target moving object is a moving object such as a pedestrian, bicycle, or animal that is expected to interfere with the vehicle's movement, in other words, a moving object for which vehicle driving assistance is desired.

[0091] In response to this, one might consider extending the exposure time of the imaging device 2 so that the area above the cutoff line CL can be clearly imaged. However, in this case, there is a risk that so-called "blown-out" highlights will occur in the area below the cutoff line CL. Blurred highlights are a phenomenon in which an area is completely whited out because the maximum amount of light that the imaging device 2 can capture is exceeded. If blurred highlights occur in the area below the cutoff line CL, even if the part of object X above the cutoff line CL can be detected, it is ultimately impossible to grasp the entire object X, and it remains difficult to determine whether or not object X is a predetermined moving object.

[0092] Therefore, in the vehicle driving support system 1 of this embodiment, an additional light distribution pattern AP is formed in the region above the cutoff line CL while maintaining the exposure time. As a result, the illuminance of the light illuminating below the cutoff line CL and the illuminance of the light illuminating above the cutoff line CL become closer in area, at least for the region including object X. Thus, even when imaging at a first exposure time T1 adjusted to match the illuminance of the diffusion pattern L1 and the focusing pattern L2, it becomes easier to image the entire object X clearly.

[0093] Therefore, the imaging control device 4 or the vehicle control device 14 can determine with higher accuracy whether an object X is a predetermined moving target by applying known target detection processing to the image IMG captured under the condition that an additional light distribution pattern AP is additionally formed on the low beam light distribution pattern LP. The target detection processing includes, for example, predetermined image processing, algorithmic recognition, deep learning, etc.

[0094] For example, when the imaging control device 4 determines whether or not an object is a moving object, if the imaging control device 4 determines that object X is a moving object, it transmits a signal to the vehicle control device 14 indicating the presence of the moving object. The imaging control device 4 or the vehicle control device 14 also transmits the same signal to the lighting control device 12 as needed. Alternatively, an image IMG may be sent from the imaging control device 4 to the vehicle control device 14, and the vehicle control device 14 may determine whether or not an object is a moving object. In this case, if the vehicle control device 14 determines that object X is a moving object, it transmits a signal to both the imaging control device 4 and the lighting control device 12 as needed, indicating the presence of the moving object. Note that when the imaging control device 4 determines whether or not an object is a moving object, it is possible to avoid control delays caused by sending an image IMG from the camera ECU to the vehicle ECU. It is also possible that the lighting control device 12 performs the determination of whether or not object X is present and whether or not it is a moving object.

[0095] When the object X included in the image IMG is a moving object, at least one of the vehicle control device 14, the image capture control device 4, and the lighting control device 12 transmits a predetermined driving support instruction signal INS. As an example, the driving support instruction signal INS includes at least one of a brake instruction signal to the brake device 26, a steering instruction signal to the steering device 28, and a passing instruction signal to at least one of the low beam unit 6 and the high beam unit 10. Furthermore, since the vehicle driving support system 1 of this embodiment is equipped with a notification device 16, the driving support instruction signal INS may also be a notification instruction signal to the notification device 16.

[0096] For example, if a target moving object is present in front of the vehicle, a brake instruction signal is transmitted from the vehicle control device 14 to the brake device 26. Upon receiving the brake instruction signal, the brake device 26 performs a braking action. This enables automatic emergency braking. Also, if a target moving object is present in front of the vehicle, a steering instruction signal is transmitted from the vehicle control device 14 to the steering device 28. Upon receiving the steering instruction signal, the steering device 28 performs a steering operation. This helps to avoid the vehicle colliding with the target moving object. Furthermore, if a target moving object is present in front of the vehicle, a notification instruction signal is transmitted from the vehicle control device 14 to the notification device 16. Upon receiving the notification instruction signal, the notification device 16 performs a notification action. This allows the driver to be notified of the presence of the target moving object.

[0097] Furthermore, if a target moving object is present in front of the vehicle, a passing instruction signal is transmitted from the lighting control device 12 to at least one of the low beam unit 6 and the high beam unit 10. Upon receiving the passing instruction signal, the low beam unit 6 repeatedly increases or decreases the illuminance of at least a portion of the low beam light distribution pattern LP to perform a passing flash. Upon receiving the passing instruction signal, the high beam unit 10 repeatedly increases or decreases the illuminance of at least a portion of the high beam light distribution pattern HP to perform a passing flash. This allows the presence of the vehicle to be communicated to the target moving object. Braking, steering, notification, and passing operations may be performed individually or in combination of two or more. In addition, the driving support instruction signal INS that instructs each operation may be transmitted by the imaging control device 4.

[0098] The lighting control device 12 controls the additional unit to reduce the illuminance of the additional light distribution pattern when at least one of the following is performed: braking by the brake device 26, steering by the steering device 28, flashing by at least one of the low beam unit 6 and the high beam unit 10, and notification by the notification device 16. In this embodiment, where the illuminance of the overhead sign light distribution pattern OHS is increased to form the additional light distribution pattern AP, for example, the lighting control device 12 controls the overhead sign forming unit 21 to return the illuminance of the additional light distribution pattern AP to the illuminance of the overhead sign light distribution pattern OHS. If the additional light distribution pattern AP is formed by a dedicated lighting unit, the additional light distribution pattern AP may be made to disappear. This avoids the unnecessary continuation of a state in which the formation of the additional light distribution pattern AP may cause glare to vehicles ahead, etc.

[0099] For example, the brake device 26 transmits a signal to the lighting control device 12 indicating that braking has been performed. The steering device 28 transmits a signal to the lighting control device 12 indicating that steering has been performed. The low beam unit 6 and the high beam unit 10 transmit signals to the lighting control device 12 indicating that flashing has been performed. The notification device 16 transmits a signal to the lighting control device 12 indicating that a notification operation has been performed. When the lighting control device 12 receives these signals, it reduces the illuminance of the additional light distribution pattern AP and returns to the overhead sign light distribution pattern OHS, as shown in Figure 7(C). In the example shown in Figure 8, the lighting control device 12 receives these signals at time Tb.

[0100] Furthermore, the driving support instruction signal INS may include a brake instruction signal for the brake device 26 and a notification instruction signal for the notification device 16. A notification instruction signal may be transmitted when the vehicle speed detected by the vehicle speed sensor 30 is below a predetermined value, and a brake instruction signal may be transmitted when the vehicle speed exceeds the predetermined value. The predetermined value can be appropriately set based on the designer's empirical knowledge or experiments and simulations conducted by the designer.

[0101] This control system allows the driver to be notified of the presence of a target object and to perform braking or steering actions when the vehicle speed is below a predetermined value and it is expected that the time it will take for the vehicle to reach the target object will be relatively long. Conversely, if the vehicle speed is above a predetermined value and it is expected that the time it will take for the vehicle to reach the target object will be relatively short, automatic emergency braking can be applied. If the vehicle is equipped with a distance measuring sensor such as millimeter-wave radar or LiDAR, the distance from the vehicle to the target object may be used in addition to the vehicle speed to determine whether to send a notification signal or a brake signal. For example, the time it will take to reach the target object may be calculated from the vehicle speed and distance, and a notification signal may be sent when the time it takes to reach the target object exceeds a predetermined value, and a brake signal may be sent when the time it takes to reach the target object is below the predetermined value.

[0102] This embodiment includes a computer program executed by the lighting device control unit 12. This computer program controls the low beam unit 6 to form a low beam light distribution pattern LP, and also causes the lighting device control unit 12 to execute a function to control the additional unit to form an additional light distribution pattern AP in at least the area above object X when object X is included in the area below the cutoff line CL in the image IMG captured by the imaging device 2. This embodiment also includes a storage medium 24 on which the computer program is stored.

[0103] Figure 9 is a flowchart illustrating an example of the operation of the vehicle driving support system 1. This flow is executed repeatedly, for example, at predetermined timings. First, a low beam light distribution pattern LP is formed (S101). Also, the area in front of the vehicle is imaged by the imaging device 2 for a first exposure time T1 (S102). Then, it is determined whether an object X exists in the region below the cutoff line CL in the image IMG (S103). If no object X exists (N in S103), this routine ends.

[0104] If object X is present (Y in S103), for example, the illuminance of the overhead sign light distribution pattern OHS is increased, and an additional light distribution pattern AP is added to the low beam light distribution pattern LP (S104). Also, the area in front of the vehicle is imaged by the imaging device 2 for a first exposure time T1 (S105). Then, it is determined whether object X is the target moving object based on the obtained image IMG (S106). If object X is not the target moving object (N in S106), this routine ends. If object X is the target moving object (Y in S106), a driving support instruction signal is transmitted (S107).

[0105] Next, it is determined whether driving assistance has been performed (S108). Whether or not driving assistance has been performed can be determined based on whether or not a signal indicating operation has been received from at least one of the brake device 26, steering device 28, low beam unit 6, and notification device 16. If driving assistance has not been performed (N in S108), the determination in step S108 is repeated. If driving assistance has been performed (Y in S108), the additional light distribution pattern AP is returned to the overhead sign light distribution pattern OHS, that is, the formation of the additional light distribution pattern AP is stopped (S109), and this routine ends.

[0106] As described above, the vehicle driving support system 1 according to this embodiment, when an object X is included in the region below the cutoff line CL in the image IMG captured under the formation of the low beam light distribution pattern LP, forms an additional light distribution pattern AP above the cutoff line CL and captures an image, and determines whether or not the object X is a target moving object based on the image obtained thereby. When the object is a predetermined target moving object, it transmits a driving support instruction signal. This makes it possible to improve the detection accuracy of target moving objects under the formation of the low beam light distribution pattern LP and improve the performance of the vehicle driving support system 1.

[0107] Embodiment 2 of the present invention has been described in detail above. Embodiment 2 described above is merely a specific example of how to implement the present invention. The content of the embodiment does not limit the technical scope of the present invention, and many design changes such as changes, additions, and deletions of components are possible as long as they do not depart from the spirit of the invention as defined in the claims. A new embodiment with design changes will have the effects of both the combined embodiment and the modification. In the embodiments described above, the content in which such design changes are possible is emphasized with notations such as "of this embodiment" or "in this embodiment," but design changes are also permitted even if there are no such notations. Any combination of the above components is also valid as an embodiment of the present invention. The hatching applied to the cross-section in the drawing does not limit the material of the object to which the hatching is applied.

[0108] (Modification) In Embodiment 2, the imaging control device 4 is composed of a camera ECU, the lighting control device 12 is composed of a lamp ECU, and the vehicle control device 14 is composed of a vehicle ECU. However, the configuration of each control device is not limited to this. For example, an ECU that functions as any of the control devices may function as all or part of the other control devices.

[0109] For example, instead of a camera ECU, a simple control circuit that controls the imaging timing and exposure time of the imaging device 2 may be mounted on the imaging device 2. In this case, for example, the image IMG is sent from the imaging device 2 to the vehicle ECU, which then performs object X detection and determination of the target moving object. In other words, the vehicle ECU functions not only as a vehicle control device 14 but also as an imaging control device 4. Then, a signal that triggers the formation of the additional light distribution pattern AP is transmitted from the vehicle ECU to the lighting device control device 12.

[0110] Alternatively, instead of a lamp ECU, a simple lighting circuit such as an LDM (LED Driving Module) may be installed in the low beam unit 6 or the high beam unit 10. In this case, for example, the vehicle ECU controls the light illumination of the low beam unit 6 and the high beam unit 10. In other words, the vehicle ECU functions not only as a vehicle control device 14 but also as a lighting device control device 12. The vehicle ECU then transmits a signal to the lighting circuit of the low beam unit 6 to instruct a change in the illuminance of the overhead sign light distribution pattern OHS, or transmits a passing instruction signal, etc., to the lighting circuit of at least one of the low beam unit 6 and the high beam unit 10.

[0111] Alternatively, a simple control circuit may be mounted on the imaging device 2 instead of the camera ECU, and a simple lighting circuit may be mounted on the low beam unit 6 or high beam unit 10 instead of the lamp ECU. In this case, the vehicle ECU functions not only as the vehicle control device 14 but also as the imaging control device 4 and the lighting device control device 12.

[0112] The invention according to Embodiment 2 described above may be specified by the following items. [Item 1] An imaging device (2) that repeatedly images the area in front of a vehicle at a predetermined period; an imaging control device (4) that controls imaging by the imaging device (2); a low beam unit (6) that can form a low beam light distribution pattern (LP) having a cutoff line (CL); an additional unit (21) that can form an additional light distribution pattern (AP) in a region above the cutoff line (CL); a lighting device control device (12) that controls the light irradiation of the low beam unit (6) and the additional unit (21); and a vehicle control device (14) that controls the vehicle, wherein the lighting device control device (12) controls the low beam unit (6) to form a low beam light distribution pattern (LP), and the imaging control device (4) controls the imaging device (2) to repeatedly take images under the formation of the low beam light distribution pattern (LP). When an object (X) is included in the region below the cutoff line (CL) in an image (IMG) captured under the formation of a low beam light distribution pattern (LP), the lighting device control unit (12) controls the additional unit (21) to form an additional light distribution pattern (AP) in at least the region above the object (X), and when the object (X) included in the image (IMG) captured under the formation of the low beam light distribution pattern (LP) and the additional light distribution pattern (AP) is a predetermined moving object, at least one of the vehicle control unit (14), the image capture control unit (4), and the lighting device control unit (12) transmits a driving support instruction signal (INS), the vehicle driving support system (1). [Item 2] The vehicle driving support system (1) comprises a high beam unit (10) capable of forming a high beam light distribution pattern (HP), and the driving support instruction signal (INS) includes at least one of a brake instruction signal to a brake device (26) mounted on the vehicle, a steering instruction signal to a steering device (28) mounted on the vehicle, and a passing instruction signal to at least one of the low beam unit (6) and the high beam unit (10), as per Item 1.[Item 3] The vehicle driving support system (1) according to Item 2, wherein the lighting control device (12) controls the additional unit (21) to reduce the illuminance of the additional light distribution pattern (AP) when at least one of the following is performed: braking by the brake device (26), steering by the steering device (28), and flashing by at least one of the low beam unit (6) and the high beam unit (10). [Item 4] The vehicle driving support system (1) according to any one of Items 1 to 3, wherein the vehicle driving support system (1) includes a notification device (16) mounted on the vehicle that notifies the driver of the presence of a target moving object, and the driving support instruction signal (INS) includes a brake instruction signal to the brake device (26) mounted on the vehicle and a notification instruction signal to the notification device (16), wherein the notification instruction signal is transmitted when the vehicle speed is below a predetermined value and a brake instruction signal is transmitted when the vehicle speed is above a predetermined value. [Item 5] An additional unit (21) capable of forming an overhead sign light distribution pattern (OHS), and an additional light distribution pattern (AP) is formed by increasing the illuminance of the overhead sign light distribution pattern (OHS), the vehicle driving support system (1) according to any of Items 1 to 4. [Item 6] A lighting device (12) that controls the light irradiation of a low beam unit (6) capable of forming a low beam light distribution pattern (LP) having a cutoff line (CL), and the light irradiation of an additional unit (21) capable of forming an additional light distribution pattern (AP) in a region above the cutoff line (CL), wherein the low beam unit (6) is controlled to form a low beam light distribution pattern (LP), and when an object (X) is included in a region below the cutoff line (CL) in an image (ING) captured by an imaging device (2), the additional unit (21) is controlled to form an additional light distribution pattern (AP) in a region above the object (X).[Item 7] A computer program executed by a lighting device control device (12) that controls the light irradiation of a low beam unit (6) capable of forming a low beam light distribution pattern (LP) having a cutoff line (CL), and the light irradiation of an additional unit (21) capable of forming an additional light distribution pattern (AP) in a region above the cutoff line (CL), wherein the computer program causes the lighting device control device (12) to execute a function that controls the low beam unit (6) to form a low beam light distribution pattern (LP), and when an object (X) is included in a region below the cutoff line (CL) in an image (IMG) captured by an imaging device (2), controls the additional unit (21) to form an additional light distribution pattern (AP) in a region above the object (X).

[0113] This invention can be used in vehicle driving support systems, lighting control devices, and computer programs.

[0114] 1. Vehicle driving support system, 2. Imaging device, 4. Imaging control device, 6. Low beam unit, 12. Lighting device control device, 14. Vehicle control device, 16. Notification device, 26. Brake device, 28. Steering device.

Claims

1. The system comprises: an imaging device that repeatedly images the area in front of a vehicle at a predetermined interval; an imaging control device that controls imaging by the imaging device; a low beam unit capable of forming a low beam light distribution pattern having a cutoff line and capable of changing the illuminance of at least a portion below the cutoff line in the low beam light distribution pattern; a lighting device control device that controls the light irradiation of the low beam unit; and a vehicle control device that controls the vehicle, wherein the lighting device control controls the low beam unit to form the low beam light distribution pattern; the imaging control device controls the imaging device to take images for a first exposure time under the formation of the low beam light distribution pattern; when an object is included in the region below the cutoff line in the image taken under the formation of the low beam light distribution pattern, the imaging control device controls the imaging device to take images for a second exposure time longer than the first exposure time; and the lighting device control device controls the low beam unit to reduce the illuminance of at least a portion of the region including the object in the low beam light distribution pattern. A vehicle driving support system in which, when the object included in an image captured under the reduced illumination conditions is a predetermined moving object, at least one of the vehicle control device, the image capture control device, and the lighting device control device transmits a driving support instruction signal.

2. The vehicle driving support system according to claim 1, wherein the vehicle driving support system comprises a high beam unit capable of forming a light distribution pattern for high beams, and the driving support instruction signal includes at least one of a brake instruction signal for a brake device mounted on the vehicle, a steering instruction signal for a steering device mounted on the vehicle, and a passing instruction signal for at least one of the low beam unit and the high beam unit.

3. The vehicle driving support system according to claim 2, wherein the lighting device controls the low beam unit to increase the reduced illuminance of the low beam light distribution pattern when at least one of the following is performed: braking by the brake device, steering by the steering device, and flashing by at least one of the low beam unit and the high beam unit.

4. The vehicle driving support system according to claim 1, comprising a notification device mounted on the vehicle for notifying the driver of the presence of the target moving object, wherein the driving support instruction signal includes a brake instruction signal to a brake device mounted on the vehicle and a notification instruction signal to the notification device, wherein the notification instruction signal is transmitted when the vehicle speed is less than or equal to a predetermined value, and the brake instruction signal is transmitted when the vehicle speed exceeds a predetermined value.

5. The vehicle driving support system according to any one of claims 1 to 4, wherein the vehicle driving support system comprises an additional unit capable of forming an additional light distribution pattern in a region above the cutoff line, and the lighting control device controls the low beam unit to reduce the illuminance of at least a portion of the region including the object, and controls the additional unit to form the additional light distribution pattern.

6. A lighting device control for controlling the light irradiation of a low beam unit capable of forming a low beam light distribution pattern having a cutoff line and changing the illuminance of at least a portion below the cutoff line in the low beam light distribution pattern, wherein the device controls the low beam unit to form the low beam light distribution pattern and, when an object is included in the region below the cutoff line in an image captured by an imaging device, controls the low beam unit to reduce the illuminance of at least a portion of the region in the low beam light distribution pattern that includes the object.

7. A computer program executed by a lighting device control device that controls the light irradiation of a low beam unit capable of forming a low beam light distribution pattern having a cutoff line and changing the illuminance of at least a portion below the cutoff line in the low beam light distribution pattern, wherein the computer program controls the low beam unit to form the low beam light distribution pattern and, when an object is included in the region below the cutoff line in an image captured by an imaging device, causes the lighting device control device to execute a function to control the low beam unit to reduce the illuminance of at least a portion of the region in the low beam light distribution pattern that includes the object.

Images