Headlight control device

Abstract

The purpose of the present disclosure is to provide a headlight control device with which it is possible to accurately assess the situation of a host vehicle and control headlights with high precision. A headlight control device according to the present disclosure comprises: a periphery-illuminance-information-receiving unit that receives periphery illuminance information regarding periphery illuminance, which is illuminance in the periphery of a host vehicle; a forward-illuminance-information-receiving unit that receives forward illuminance information regarding forward illuminance, which is illuminance farther than the host vehicle periphery and forward in the traveling direction of the host vehicle; an outside-illuminance-information-receiving unit that receives outside illuminance information regarding outside illuminance, which is illuminance farther than the host vehicle periphery and outside of the host vehicle in the traveling direction; a situation assessment unit that assesses the situation of the host vehicle on the basis of the periphery illuminance information, the forward illuminance information, or the outside illuminance information; and a lighting control unit that controls the lighting or extinguishing of the headlights of the host vehicle in accordance with the situation of the host vehicle assessed by the situation assessment unit. The situation assessment unit assesses the situation of the host vehicle on the basis of a map of which one axis is periphery illuminance and the other axis is at least one of forward illuminance and outside illuminance.

Description

Headlamp control device

[0001] The present disclosure relates to a headlight control device that controls the headlights of a host vehicle.

[0002] In conventional auto light systems, a light receiving sensor installed inside the vehicle measures the illuminance of light shining from above the vehicle through the windshield. If the illuminance exceeds a predetermined threshold, the system determines that the area ahead of the vehicle is bright and automatically turns off the headlights. If the illuminance falls below the threshold, the system determines that the area ahead of the vehicle is dark and automatically turns on the headlights.

[0003] A technology has been disclosed in which, using the above-mentioned automatic light system, the road area ahead of the vehicle, the outer area in the vehicle width direction, and the road area are set based on images captured by a forward-facing camera installed on the vehicle, and the headlights are controlled by determining, based on the brightness of each area, whether the vehicle is traveling in a tunnel, traveling parallel to an overpass, or passing under an overpass (see, for example, Patent Document 1).

[0004] Patent No. 4937199

[0005] The new road vehicle safety standards, which came into effect in April 2020 and require the installation of automatic headlights, stipulate that the headlights be turned on when the illuminance around the vehicle is less than 1,000 Lx and turned off when the illuminance around the vehicle is greater than 7,000 Lx. According to this requirement, the technology of Patent Document 1 turns off the headlights if the area ahead of the vehicle is bright, even if the illuminance around the vehicle is sufficiently less than 1,000 Lx. Conversely, even if the illuminance around the vehicle is sufficiently greater than 7,000 Lx, the headlights are turned on if the area ahead of the vehicle is dark. This is because the automatic headlight system determines whether to turn the headlights on or off using only a specific threshold value. Specifically, when the illuminance around the vehicle is sufficiently high or sufficiently low, the headlights should be controlled taking into account the illuminance around the vehicle, but the determination based on the brightness of the image captured by the forward camera takes priority. Therefore, the lights will be turned on and off more than necessary, which may cause discomfort to the driver and may impair driving safety.

[0006] Furthermore, the technology of Patent Document 1 uses images captured by a forward camera to determine brightness based on the brightness of the road area ahead of the vehicle, the area outside the vehicle width direction, and the road area. However, compared to illuminance, luminance is generally more susceptible to influences from the viewing direction and the reflectance of the material or color of the object on the illuminated surface, which can easily lead to errors. Therefore, rather than comparing the brightness (illuminance) around the vehicle with the brightness (luminance) of the road area ahead of the vehicle, the area outside the vehicle width direction, and the road area using different physical quantities, it is possible to control the headlights more accurately by comparing them using the same physical quantity, illuminance.

[0007] As described above, in order to control the headlights with precision, it is necessary to accurately judge the situation of the vehicle, but conventional technologies including Patent Document 1 are not sufficient and there is room for improvement.

[0008] The present disclosure has been made to solve such problems, and aims to provide a headlight control device that can accurately determine the situation of the vehicle and control the headlights with high precision.

[0009] In order to solve the above problems, the headlamp control device according to the present disclosure includes a surrounding illuminance information receiving unit that receives surrounding illuminance information related to surrounding illuminance, which is the illuminance around the host vehicle, from a light receiving sensor provided inside the vehicle cabin; a forward illuminance information receiving unit that receives forward illuminance information related to forward illuminance, which is the illuminance farther from the host vehicle's periphery and ahead in the direction of travel of the host vehicle; an outer illuminance information receiving unit that receives outer illuminance information related to outer illuminance, which is the illuminance farther from the host vehicle's periphery and outside in the direction of travel of the host vehicle; a situation determination unit that determines the situation of the host vehicle based on the surrounding illuminance information, the forward illuminance information, or the outer illuminance information; and an illumination control unit that controls the turning on or off of the host vehicle's headlights depending on the situation of the host vehicle determined by the situation determination unit, and the situation determination unit determines the situation of the host vehicle based on a map that has surrounding illuminance as one axis and at least one of the forward illuminance and the outer illuminance as the other axis.

[0010] According to the present disclosure, it is possible to accurately determine the situation of the host vehicle and control the headlights with high precision.

[0011] The objects, features, aspects, and advantages of the present disclosure will become more apparent from the following detailed description and the accompanying drawings.

[0012] FIG. 1 is a block diagram showing an example of an overall configuration including a headlight control device according to an embodiment. FIG. 2 is a diagram for explaining setting of an area according to an embodiment. FIG. 3 is a block diagram showing an example of a hardware configuration of a headlight control device according to an embodiment. FIG. 4 is a diagram for explaining a situation of passing under an overpass. FIG. 5 is a diagram for explaining the operation of a conventional auto light system when passing under an overpass. FIG. 6 is a diagram for explaining the operation of a headlight control device according to an embodiment when passing under an overpass. FIG. 7 is a flowchart showing an example of overall operation including a headlight control device according to an embodiment when passing under an overpass. FIG. 8 is a diagram for explaining a situation of parallel running under an overpass. FIG. 9 is a flowchart showing an example of overall operation including a headlight control device according to an embodiment when running side by side under an overpass. FIG. 10 is a diagram showing a map used for determination when passing under an overpass according to an embodiment.

[0013] <Embodiment> <Overall Configuration> Fig. 1 is a block diagram showing an example of an overall configuration including a headlight control device 1 according to an embodiment. The headlight control device 1 is connected to a forward recognition unit 12, a vehicle speed sensor 18, an auto light system 23, headlights 26, sidelights 27, taillights 28, an instrument panel 29, a navigation display 30, and an auto light switch 31. The headlight control device 1, a driver monitor 7, and a high-precision locator 19 are connected to the forward recognition unit 12. The high-precision locator 19 is connected to the forward recognition unit 12, a GNSS (Global Navigation Satellite System) receiver 17, and a vehicle speed sensor 18. It is assumed that each of these components is mounted on the host vehicle.

[0014] The driver monitor 7 includes an interior camera 8, a near-infrared light emitter 9, a pupil diameter detector 10, and a gaze direction detector 11. The interior camera 8 is a camera that captures images of the interior of the vehicle, capturing at least the face of the driver. The near-infrared light emitter 9 emits near-infrared light when the interior camera 8 captures an image. The pupil diameter detector 10 detects the driver's pupil diameter from the image captured by the interior camera 8. The gaze direction detector 11 detects the driver's gaze direction from the image captured by the interior camera 8. In this way, when the interior camera 8 captures an image of the driver, the driver monitor 7 detects the driver's pupil diameter and the driver's gaze direction by the interior camera 8 receiving near-infrared light emitted by the near-infrared light emitter 9.

[0015] The forward recognition unit 12 includes a forward camera 13, a white line detection unit 14, a forward illuminance information transmission unit 15, and an outside illuminance information transmission unit 16. The forward camera 13 captures an image of the area ahead of the vehicle. The white line detection unit 14 detects the position of a white line on the road on which the vehicle is traveling from the image captured by the forward camera 13.

[0016] The forward illuminance information transmitter 15 measures the luminance in an area farther away than the periphery of the host vehicle and in the forward direction of travel of the host vehicle based on the image captured by the forward camera 13, and converts the measured luminance into illuminance. The forward illuminance information transmitter 15 then transmits the converted illuminance to the headlamp control device 1. That is, the forward illuminance information transmitter 15 transmits forward illuminance information relating to the illuminance (forward illuminance) in an area farther away than the periphery of the host vehicle and in the forward direction of travel of the host vehicle.

[0017] The outside illuminance information transmitter 16 measures the luminance farther from the periphery of the host vehicle and outside in the traveling direction of the host vehicle based on the image captured by the front camera 13, and converts it into illuminance. The outside illuminance information transmitter 16 also transmits the converted illuminance to the headlamp control device 1. That is, the outside illuminance information transmitter 16 transmits outside illuminance information relating to the illuminance (outside illuminance) farther from the periphery of the host vehicle and outside in the traveling direction of the host vehicle.

[0018] The high-accuracy locator 19 includes a vehicle position estimation unit 20, a high-accuracy map data storage unit 21, and a map data output unit 22. The vehicle position estimation unit 20 estimates the position of the vehicle based on the signal received by the GNSS receiver 17, the speed of the vehicle measured by the vehicle speed sensor 18, and the high-accuracy map stored in the high-accuracy map data storage unit 21. The GNSS receiver 17 receives signals related to the position of the vehicle from GNSS satellites. The vehicle speed sensor 18 measures the speed of the vehicle.

[0019] The high-precision map data storage unit 21 is a storage medium such as a memory or an HDD (Hard Disk Drive), and stores map data including roads in lane units. The high-precision map data storage unit 21 may be provided outside the high-precision locator 19. In this case, the high-precision locator 19 acquires the high-precision map data from the external storage medium.

[0020] The map data output unit 22 outputs the vehicle position estimated by the vehicle position estimation unit 20 and the high-precision map data stored in the high-precision map data storage unit 21 to the forward recognition unit 12 .

[0021] The automatic light system 23 includes a light receiving sensor 24 and an ambient illuminance information transmitter 25. The automatic light system 23 operates when an automatic light switch 31 is in the ON state, and stops operating when the automatic light switch 31 is in the OFF state.

[0022] The light receiving sensor 24 is installed facing upward inside the vehicle cabin and converts the brightness around the vehicle into an electrical signal. The surrounding illuminance information transmitter 25 measures the illuminance around the vehicle (ambient illuminance) based on the electrical signal converted by the light receiving sensor 24. The surrounding illuminance information transmitter 25 also transmits the measured illuminance around the vehicle to the headlamp control device 1. In other words, the surrounding illuminance information transmitter 25 transmits surrounding illuminance information related to the illuminance around the vehicle.

[0023] The headlamp control device 1 includes a forward illuminance information receiving unit 2, an outside illuminance information receiving unit 3, a surrounding illuminance information receiving unit 4, a situation determination unit 5, and a lighting control unit 6. Note that each function of the headlamp control device 1 may be processed by another ECU (Electronic Control Unit), such as an ADAS (Advanced Driver-Assistance Systems) unit.

[0024] The forward illuminance information receiving unit 2 receives forward illuminance information transmitted by the forward illuminance information transmitting unit 15 of the forward recognition unit 12. The outside illuminance information receiving unit 3 receives outside illuminance information transmitted by the outside illuminance information transmitting unit 16 of the forward recognition unit 12. The surrounding illuminance information receiving unit 4 receives surrounding illuminance information transmitted by the surrounding illuminance information transmitting unit 25 of the auto light system 23. Note that the forward illuminance information receiving unit 2 may determine the forward illuminance, the outside illuminance information receiving unit 3 may determine the outside illuminance, or the surrounding illuminance information receiving unit 4 may determine the surrounding illuminance.

[0025] The situation determination unit 5 determines the driving situation of the vehicle based on the forward illuminance information received by the forward illuminance information receiving unit 2, the external illuminance information received by the external illuminance information receiving unit 3, or the peripheral illuminance information received by the peripheral illuminance information receiving unit 4.

[0026] The lighting control unit 6 controls the turning on or off of the headlights 26 of the vehicle in accordance with the driving conditions of the vehicle determined by the condition determination unit 5. The lighting control unit 6 may also control the turning on, turning off, or light distribution of the sidelights 27, taillights 28, instrument panel 29, and navigation display 30 in accordance with the driving conditions of the vehicle determined by the condition determination unit 5.

[0027] 2 is a diagram for explaining the setting of areas according to the embodiment. In FIG. 2, virtual areas divided into a grid pattern correspond to image areas captured by the forward camera 13 of the forward recognition unit 12.

[0028] The area FA is an area (forward area) that is farther away from the surroundings of the vehicle and in front of the vehicle in the direction of travel in the image area captured by the forward camera 13. The forward illumination information transmitter 15 calculates the illumination intensity (forward illumination intensity) of the area FA.

[0029] The area DA is an area (outer area) that is farther away from the vicinity of the vehicle and outside the traveling direction of the vehicle in the image area captured by the front camera 13. The outside illuminance information transmitter 16 calculates the illuminance (outer illuminance) of the area DA.

[0030] The area SA is an area (surrounding area) around the vehicle where brightness is detected by the light receiving sensor 24 of the auto light system 23. The surrounding illuminance information transmitter 25 obtains the illuminance (surrounding illuminance) of the area SA.

[0031] <Hardware Configuration of Headlamp Control Device> FIG. 3 is a block diagram showing an example of the hardware configuration of the headlamp control device 1. As shown in FIG.

[0032] The headlamp control device 1 includes a processor 41, a memory 42, and a storage medium 43 in order to realize the functions of the forward illuminance information receiving unit 2, the outside illuminance information receiving unit 3, the surrounding illuminance information receiving unit 4, the situation determination unit 5, and the lighting control unit 6. The headlamp control device 1 may further include an input unit 44 and an output unit 45 as necessary.

[0033] The processor 41 is the core of a well-known computer that operates the hardware according to software.

[0034] The memory 42 is configured by, for example, a dynamic random access memory (DRAM) or a static random access memory (SRAM).

[0035] The storage medium 43 is configured by, for example, an HDD, a solid state drive (SSD), a read only memory (ROM), etc. The storage medium 43 stores a program 46. The program 46 is a group of instructions that define the content of the processing to be executed by the processor 41.

[0036] The input unit 44 is configured, for example, by a camera or a receiving unit, etc. The output unit 45 is configured, for example, by a transmitting unit, etc.

[0037] In the hardware configuration of the headlamp control device 1 described above, the processor 41 executes the program 46 stored in the storage medium 43 on the memory 42, and controls the operation of the input unit 44 and the output unit 45 as necessary. This enables the functions of the forward illuminance information receiving unit 2, the outside illuminance information receiving unit 3, the ambient illuminance information receiving unit 4, the situation determination unit 5, and the lighting control unit 6 in the headlamp control device 1 to be realized.

[0038] <Operation> The following describes the operation when the host vehicle passes under an overpass (see FIG. 4) and the operation when the host vehicle runs parallel to the overpass (see FIG. 9). Note that the operation when the host vehicle passes under an overpass will be described separately as the operation of a conventional auto light system and the operation of the headlamp control device 1 according to the embodiment.

[0039] <Operation of a conventional automatic light system when passing under an overpass> Figure 5 is a diagram for explaining the operation of a conventional automatic light system when passing under an overpass, showing the relationship between the state of the vehicle's headlights and the ambient illuminance of the vehicle (solid lines in the figure) before, during, and after passing under the overpass. In Figure 5, the horizontal axis represents time. Note that for simplicity's sake, Figure 5 only shows the threshold value for lighting (the "on threshold" indicated by the dashed line in the figure) as the threshold value for ambient illuminance, but in reality, threshold values ​​for lighting and lighting are set separately.

[0040] Before passing under the overpass (time 0 to time T1), the ambient illuminance is higher than the lighting threshold, so the headlights of the vehicle are turned off until time T1.

[0041] While passing under the overpass (time T1 to time T3), the ambient illuminance is lower than the lighting threshold. Therefore, the headlights of the vehicle remain off from time T1 until time T2, when the lighting operation time Ton by the automatic light system has elapsed. After that, the headlights of the vehicle are turned on at time T2 and remain on until time T3.

[0042] After passing under the overpass (after time T3), the ambient illuminance is higher than the lighting threshold. Therefore, the headlights of the vehicle remain on from time T3 until time T4, when the automatic light system's lighting-off operation time Toff has elapsed. Then, at time T4, the headlights of the vehicle are turned off.

[0043] When a vehicle passes under an overpass during the day as shown in Figure 4, the conventional automatic light system shown in Figure 5 automatically turns on the headlights because the area under the overpass is dimly lit, and then turns off the headlights after the vehicle passes under the overpass because the area around the vehicle becomes bright. However, if the driver is aware that the area after passing under the overpass is bright before passing under the overpass, the driver's visibility is good, so in such a case, the automatic light system's operation of turning the headlights on and off can cause discomfort to the driver.

[0044] <Operation of Headlight Control Device According to an Embodiment When Passing Under an Overpass> Figure 6 is a diagram for explaining the operation of the headlight control device 1 according to an embodiment when passing under an overpass, and shows the relationship between the state of the headlights 26 of the host vehicle before passing under an overpass, during passing under an overpass, after passing under an overpass, and during nighttime driving, and the surrounding illuminance of the host vehicle (solid lines in the figure) and the front illuminance of the host vehicle (solid lines in the figure). In Figure 6, the horizontal axis represents time. Note that for simplicity of explanation, Figure 6 only shows a threshold value for turning on the surrounding illuminance (the "on threshold" indicated by the dashed line in the figure) and a threshold value for turning off the front illuminance (the "off threshold" indicated by the dashed line in the figure). However, in reality, multiple threshold values ​​are set that map the surrounding illuminance and the front illuminance.

[0045] Before passing under the overpass (time 0 to time T5), the ambient illuminance is higher than the lighting threshold, so the headlights 26 of the vehicle are turned off until time T1.

[0046] While passing under the overpass (time T5 to time T6), the ambient illuminance is lower than the on threshold, but the forward illuminance is higher than the off threshold. Therefore, from time T5 to time T6, the headlights 26 of the vehicle are turned off. Table 1 below shows the ambient illuminance, forward illuminance, and the state of the headlights 26.

[0047]

[0048] After passing under the overpass (time T6 to time T7), the ambient illuminance is higher than the turn-on threshold and the forward illuminance is higher than the turn-off threshold. Therefore, from time T6 to time T7, the headlights 26 of the vehicle are turned off.

[0049] During nighttime driving (after time T7), the ambient illuminance is lower than the on threshold and the forward illuminance is lower than the off threshold. Therefore, the headlights 26 of the vehicle remain off from time T7 until time T8, when the lighting operation time Ton by the automatic light system has elapsed. Then, at time T8, the headlights 26 of the vehicle are turned on.

[0050] When a vehicle 50 passes under an overpass during the day as shown in Fig. 4, the conventional automatic light system shown in Fig. 5 turns on the headlights because the area under the overpass is dim and unlit. On the other hand, the headlight control device 1 according to the embodiment does not turn on the headlights 26 while the vehicle is passing under the overpass if the area after passing under the overpass is bright. This prevents the headlights 26 from being turned on unnecessarily, thereby reducing annoyance to the driver and improving comfort.

[0051] FIG. 7 is a flowchart showing an example of the overall operation including the headlamp control device 1 according to the embodiment when passing under an overpass.

[0052] In step S101, the headlamp control device 1 determines whether the automatic light system 23 is in the ON state. Specifically, if the automatic light switch 31 is in the ON state, the headlamp control device 1 determines that the automatic light system 23 is in the ON state. If the automatic light system 23 is in the ON state, the process proceeds to step S102. On the other hand, if the automatic light system 23 is not in the ON state (if the automatic light system 23 is in the OFF state), the process of step S101 is repeated.

[0053] In step S102, the surrounding illuminance information transmission unit 25 of the auto light system 23 measures the surrounding illuminance of the vehicle. Specifically, the surrounding illuminance information transmission unit 25 measures the illuminance of an area SA shown in Figure 2. Thereafter, the surrounding illuminance information transmission unit 25 transmits the surrounding illuminance information to the headlamp control device 1.

[0054] In step S103 , the forward illumination information transmission unit 15 of the forward recognition unit 12 acquires an image of the area ahead of the vehicle from the forward camera 13 .

[0055] In step S104 , the forward illumination information transmitter 15 sets a forward area (area FA shown in FIG. 2 ) based on the image captured by the forward camera 13 .

[0056] In step S105, the forward illuminance information transmission unit 15 calculates the illuminance of the forward area (forward illuminance), and then transmits the forward illuminance information to the headlamp control device 1.

[0057] In step S106, the forward illuminance information receiving unit 2 of the headlamp control device 1 receives forward illuminance information from the forward recognition unit 12. The surrounding illuminance information receiving unit 4 receives surrounding illuminance information from the auto light system 23. The situation determination unit 5 then determines the driving situation of the host vehicle based on the forward illuminance information received by the forward illuminance information receiving unit 2 and the surrounding illuminance information received by the surrounding illuminance information receiving unit 4. Specifically, the situation determination unit 5 determines the driving situation of the host vehicle based on the forward illuminance information, the surrounding illuminance information, and the map shown in Figure 8. Details of the map shown in Figure 8 will be described later.

[0058] The situation determination unit 5 determines whether the determination result based on the map shown in FIG. 8 is "keep on or keep off." If the determination result based on the map shown in FIG. 8 is "keep on or keep off," the process proceeds to step S107. In this case, the situation determination unit 5 determines that the vehicle is in a driving situation in which the headlights 26 should be "kept on or keep off." On the other hand, if the determination result based on the map shown in FIG. 8 is not "keep on or keep off," the process proceeds to step S108.

[0059] In step S107, the lighting control unit 6 controls the headlights 26 to maintain the previous state of the headlights 26 in accordance with the determination result of the situation determination unit 5. Note that the initial state of the headlights 26 may be set to an initial value (for example, off).

[0060] In step S108, the situation determination unit 5 determines whether the determination result based on the map shown in Fig. 8 is "on." If the determination result based on the map shown in Fig. 8 is "on," the process proceeds to step S109. On the other hand, if the determination result based on the map shown in Fig. 8 is not "on," the process proceeds to step S110. In this case, the situation determination unit 5 determines that the situation is such that turning on the headlights 26 should be prohibited.

[0061] In step S109, the lighting control unit 6 controls the headlights 26 to be turned on in accordance with the determination result of the situation determination unit 5.

[0062] In step S110, the lighting control unit 6 controls the headlights 26 to be turned off in accordance with the determination result of the situation determination unit 5.

[0063] Here, the map shown in FIG. 8 will be described.

[0064] In Fig. 8, the vertical axis represents forward illuminance, and a threshold value TH1 is set. The horizontal axis represents ambient illuminance, and threshold values ​​TH2, TH3, and TH4 are set. The threshold values ​​TH1 to TH4 set three states of the headlights 26: "on," "off," and "maintained on or off." These states correspond to the driving conditions of the vehicle. The threshold values ​​TH1 to TH4 are changeable parameter values.

[0065] For example, the threshold value TH3 for the ambient illuminance is set to 1000 Lx, which is a requirement of the new road vehicle safety standards. The threshold value TH4 is also set to 7000 Lx, which is a requirement of the new road vehicle safety standards. The threshold value TH2 is set to a value (e.g., 500 Lx) such that the headlights 26 are always turned on regardless of the value of the forward illuminance when the ambient illuminance is sufficiently low and the area around the vehicle is clearly dark.

[0066] The threshold value TH1 of the forward illumination is set to a value (for example, 500 Lx) that allows the forward area to be determined to be sufficiently bright when the ambient illumination is dark and falls between the threshold values ​​TH2 and TH3.

[0067] By setting the threshold values ​​TH1 to TH4 as described above, when the ambient illuminance is between the threshold value TH2 (500 Lx) and the threshold value TH3 (1000 Lx) and the forward illuminance is greater than the threshold value TH1 (500 Lx), the situation determination unit 5 determines that the vehicle is passing under an overpass. In this case, the lighting control unit 6 controls the headlights 26 to be turned on. This makes it possible to accurately determine the situation of the vehicle and control the headlights 26 with high precision.

[0068] <Operations when traveling side by side under an overpass> As shown in FIG. 9, operations when the vehicle 50 travels side by side under an overpass will be described.

[0069] FIG. 10 is a flowchart showing an example of the overall operation including the headlamp control device 1 according to the embodiment when vehicles are traveling side by side under an overpass.

[0070] In step S201, the headlamp control device 1 determines whether the automatic light system 23 is in the ON state. Specifically, if the automatic light switch 31 is in the ON state, the headlamp control device 1 determines that the automatic light system 23 is in the ON state. If the automatic light system 23 is in the ON state, the process proceeds to step S202. On the other hand, if the automatic light system 23 is not in the ON state (if the automatic light system 23 is in the OFF state), the process of step S201 is repeated.

[0071] In step S202, the surrounding illuminance information transmission unit 25 of the auto light system 23 measures the surrounding illuminance of the vehicle. Specifically, the surrounding illuminance information transmission unit 25 measures the illuminance of an area SA shown in Fig. 2. Thereafter, the surrounding illuminance information transmission unit 25 transmits the surrounding illuminance information to the headlamp control device 1.

[0072] In step S203, the forward illumination information transmission unit 15 of the forward recognition unit 12 acquires an image of the area ahead of the host vehicle from the forward camera 13.

[0073] In step S204, the forward illumination information transmitter 15 sets a forward area (area FA shown in FIG. 2) and an outer area (area DA shown in FIG. 2) based on the image captured by the forward camera 13.

[0074] In step S205, the forward illuminance information transmission unit 15 calculates the illuminance of the forward area (forward illuminance), and then transmits the forward illuminance information to the headlamp control device 1.

[0075] In step S206, the forward illuminance information receiver 2 of the headlamp control device 1 receives forward illuminance information from the forward recognition unit 12. Then, the situation determination unit 5 determines whether the forward illuminance is equal to or less than a predetermined value based on the forward illuminance information received by the forward illuminance information receiver 2. If the forward illuminance is not equal to or less than the predetermined value, the process proceeds to step S207. On the other hand, if the forward illuminance is equal to or less than the predetermined value, the process proceeds to step S212.

[0076] In step S207, the surrounding illuminance information receiving unit 4 receives surrounding illuminance information from the auto light system 23. Then, the situation determining unit 5 determines whether the surrounding illuminance is equal to or less than a predetermined value based on the surrounding illuminance information received by the surrounding illuminance information receiving unit 4. If the surrounding illuminance is not equal to or less than the predetermined value, the process proceeds to step S208. On the other hand, if the surrounding illuminance is equal to or less than the predetermined value, the process proceeds to step S209.

[0077] In step S208, the situation determination unit 5 determines whether the ambient illuminance is equal to or greater than a predetermined value based on the ambient illuminance information received by the ambient illuminance information receiving unit 4. If the ambient illuminance is equal to or greater than the predetermined value, the process proceeds to step S210. On the other hand, if the ambient illuminance is not equal to or greater than the predetermined value, the process proceeds to step S211. Note that the predetermined value in step S207 and the predetermined value in step S208 may be the same value or different values.

[0078] In step S209, the lighting control unit 6 controls the headlights 26 to be turned on in accordance with the determination result of the situation determination unit 5.

[0079] In step S210, the lighting control unit 6 controls the headlights 26 to be turned off in accordance with the determination result of the situation determination unit 5.

[0080] In step S211, the lighting control unit 6 controls the headlights 26 to maintain the previous state of the headlights 26 in accordance with the determination result of the situation determination unit 5. Note that the initial state of the headlights 26 may be set to an initial value (for example, off).

[0081] In step S212, the outside illuminance information transmitter 16 calculates the illuminance of the outside area (outside illuminance), and then transmits the outside illuminance information to the headlamp control device 1.

[0082] In step S213, the outside illuminance information receiving unit 3 receives outside illuminance information from the forward recognition unit 12. Then, the situation determination unit 5 determines the traveling situation of the host vehicle based on the outside illuminance information received by the outside illuminance information receiving unit 3 and the surrounding illuminance information received by the surrounding illuminance information receiving unit 4. Specifically, the situation determination unit 5 determines the traveling situation of the host vehicle based on the outside illuminance information, the surrounding illuminance information, and the map shown in Fig. 11. Details of the map shown in Fig. 11 will be described later.

[0083] The situation determination unit 5 determines whether the determination result based on the map shown in Fig. 11 is "keep on or keep off." If the determination result based on the map shown in Fig. 11 is "keep on or keep off," the process proceeds to step S214. In this case, the situation determination unit 5 determines that the vehicle is in a driving situation in which the headlights 26 should be "kept on or keep off." On the other hand, if the determination result based on the map shown in Fig. 11 is not "keep on or keep off," the process proceeds to step S215.

[0084] In step S214, the lighting control unit 6 controls the headlights 26 to maintain the previous state of the headlights 26 in accordance with the determination result of the situation determination unit 5. Note that the initial value of the headlights 26 (for example, off) may be set.

[0085] In step S215, the situation determination unit 5 determines whether the determination result based on the map shown in FIG. 11 is "on." If the determination result based on the map shown in FIG. 11 is "on," the process proceeds to step S216. In this case, the situation determination unit 5 determines that the situation requires the headlights 26 to be turned on. On the other hand, if the determination result based on the map shown in FIG. 11 is not "on," the process proceeds to step S217.

[0086] In step S216, the lighting control unit 6 controls the headlights 26 to be turned on in accordance with the determination result of the situation determination unit 5.

[0087] In step S217, the lighting control unit 6 controls the headlights 26 to be turned off in accordance with the determination result of the situation determination unit 5.

[0088] Here, the map shown in FIG. 11 will be described.

[0089] In Fig. 11, the vertical axis represents the external illuminance, and a threshold value TH5 is set. The horizontal axis represents the ambient illuminance, and threshold values ​​TH6, TH7, and TH8 are set. The threshold values ​​TH5 to TH8 set three states of the headlights 26: "on," "off," and "maintained on or off." These states correspond to the driving conditions of the vehicle. The threshold values ​​TH5 to TH8 are changeable parameter values.

[0090] For example, the threshold value TH6 for the ambient illuminance is set to 1000 Lx, which is a requirement of the new road vehicle safety standards. The threshold value TH8 is also set to 7000 Lx, which is a requirement of the new safety standards. The threshold value TH7 is set to a value (e.g., 3000 Lx) that defines the area within which the automatic light system will not turn off the headlights when the vehicle is traveling alongside the vehicle under an overpass during the daytime, due to the bright light coming from the outside illuminating the underpass and brightening the area around the vehicle.

[0091] As shown in FIG. 9 , when a vehicle is traveling parallel to another vehicle under an overpass during the day, incident light from a sufficiently bright outer area illuminates the underpass, brightening the area around the vehicle. In such a case, conventional automatic light systems turn off the headlights. However, when the area ahead is dark, it may be better to turn on the headlights to ensure the driver's visibility. In the headlight control device 1 according to the embodiment, by setting the threshold values ​​TH5 to TH8 as described above, if the ambient illuminance is between threshold values ​​TH7 (3000 Lx) and TH8 (7000 Lx) and the outer illuminance is greater than threshold value TH5 (7000 Lx), the situation determination unit 5 determines that the vehicle is traveling parallel to another vehicle under an overpass. In this case, the lighting control unit 6 controls the headlights 26 to be turned on. This improves driver comfort. In other words, the situation of the vehicle can be accurately determined and the headlights 26 can be controlled with precision.

[0092] <Modification 1> The forward illumination information receiving unit 2 may receive forward illumination information relating to forward illumination based on the pupil diameter of the driver of the vehicle.

[0093] Specifically, the pupil diameter detection unit 10 of the driver monitor 7 detects the driver's pupil diameter from the video captured by the in-vehicle camera 8. Generally, the pupil diameter of a human pupil changes depending on the brightness during natural vision (when no light is directly incident on the eye). Specifically, the higher the brightness, the smaller the pupil diameter. The pupil diameter detection unit 10 transmits information regarding the detected pupil diameter of the driver to the forward recognition unit 12.

[0094] The forward illuminance information transmission unit 15 of the forward recognition unit 12 calculates the luminance of the area ahead from the pupil diameter of the driver received from the driver monitor 7, and converts the calculated luminance into illuminance. Then, the forward illuminance information transmission unit 15 transmits forward illuminance information related to the converted illuminance (forward illuminance) to the headlamp control device 1. In this way, the forward illuminance can be obtained using the pupil diameter of the driver.

[0095] The driver's line of sight is not fixed in a certain direction but changes depending on the situation. Therefore, the forward illuminance information transmitter 15 may receive information regarding the driver's line of sight from the line of sight direction detector 11 of the driver monitor 7. In this case, the forward illuminance information transmitter 15 calculates the forward illuminance based on the driver's pupil diameter when the driver's line of sight remains in the same direction for a predetermined period of time or longer, based on the driver's pupil diameter and the driver's line of sight direction.

[0096] <Variation 2> The forward illuminance information receiving unit 2 or the external illuminance information receiving unit 3 may receive forward illuminance information or external illuminance information relating to forward illuminance or external illuminance based on the brightness of an image captured by a forward camera 13 that captures an image in front of the vehicle.

[0097] Specifically, the forward illuminance information transmitter 15 of the forward recognition unit 12 identifies a forward area based on the brightness of the image captured by the forward camera 13, and calculates the illuminance of the identified forward area (forward illuminance). Similarly, the outside illuminance information transmitter 16 calculates the illuminance of an outside area (outside illuminance).

[0098] In this way, the brightness of the image captured in front of the vehicle can be used to determine the forward illuminance and the outside illuminance.

[0099] In addition, for an image taken in front of the vehicle, the range of 20 degrees to the left and right of the front may be defined as the front area, and the range of 70 degrees or more to the left and right of the front may be defined as the outer area.

[0100] <Modification 3> The forward area and the outer area may be identified based on the line of sight of the driver of the vehicle and the brightness of an image captured of the area ahead of the vehicle.

[0101] Specifically, the forward illuminance information transmitter 15 of the forward recognition unit 12 identifies the forward area based on the driver's line of sight received from the line of sight direction detector 11 of the driver monitor 7 and the brightness of the image of the area ahead of the vehicle captured by the forward camera 13. Similarly, the outside illuminance information transmitter 16 identifies the outside area.

[0102] In this way, the driver's line of sight can be used to identify the front area and the outside area.

[0103] <Modification 4> The forward area and the outer area may be identified based on map information, position information of the host vehicle, and brightness of an image captured in front of the host vehicle.

[0104] Specifically, the forward illuminance information transmitter 15 of the forward recognition unit 12 identifies the forward area based on the high-precision map data and the position of the host vehicle received from the high-precision locator 19, and the brightness of the image of the area ahead of the host vehicle captured by the forward camera 13. Similarly, the outer illuminance information transmitter 16 identifies the outer area.

[0105] In this way, the forward area and the outer area can be identified using map information and the position information of the vehicle.

[0106] <Modification 5> The forward area and the outer area may be identified based on the position information of the white lines and the brightness of the image.

[0107] Specifically, the forward illuminance information transmitter 15 of the forward recognition unit 12 identifies the forward area based on the position of the white line received from the white line detector 14 and the brightness of the image of the area ahead of the vehicle captured by the forward camera 13. Similarly, the outer illuminance information transmitter 16 identifies the outer area.

[0108] In this way, the forward area and the outer area can be identified using the position information of the white lines.

[0109] <Modification 6> The lighting control unit 6 may adjust the brightness of the on-board devices of the host vehicle according to the driving situation of the host vehicle determined by the situation determination unit 5. Examples of the on-board devices include the instrument panel 29 and the navigation display 30 shown in FIG.

[0110] If the brightness of the in-vehicle device screen is dimmed when the surroundings of the vehicle are bright, the driver may have difficulty recognizing the displayed content. By dimming the brightness of the in-vehicle device according to the driving conditions of the vehicle as described above, the sense of incongruity with the surrounding brightness of the vehicle can be reduced.

[0111] <Variation 7> When a first situation determined based on a first map (the map shown in FIG. 8 ) having peripheral illuminance on one axis and forward illuminance on the other axis does not match a second situation determined based on a second map (the map shown in FIG. 11 ) having peripheral illuminance on one axis and outer illuminance on the other axis, and either the first situation or the second situation is a situation in which the headlights 26 should be turned on, the situation determination unit 5 may determine that the headlights 26 should be turned on. This can contribute to safe driving of the host vehicle.

[0112] Within the scope of the present disclosure, the embodiments and modifications may be freely combined, and the embodiments and modifications may be modified or omitted as appropriate.

[0113] Although the present disclosure has been described in detail, the above description is illustrative in all respects and is not restrictive. It is understood that countless variations not illustrated can be envisioned.

[0114] 1 Headlamp control device, 2 Forward illuminance information receiving unit, 3 Outside illuminance information receiving unit, 4 Surrounding illuminance information receiving unit, 5 Situation judgment unit, 6 Lighting control unit, 7 Driver monitor, 8 In-vehicle camera, 9 Near-infrared light emitting unit, 10 Pupil diameter detection unit, 11 Gaze direction detection unit, 12 Forward recognition unit, 13 Forward camera, 14 White line detection unit, 15 Forward illuminance information transmitting unit, 16 Outside illuminance information transmitting unit, 17 GNSS receiver, 18 Vehicle speed sensor, 19 High-precision locator, 20 Vehicle position estimation unit, 21 High-precision map data storage unit, 22 Map data output unit, 23 Auto light system, 24 Light receiving sensor, 25 Surrounding illuminance information transmitting unit, 26 Headlamp, 27 Sidelight, 28 Taillight, 29 Instrument panel, 30 Navigation display, 31 Auto light switch, 41 Processor, 42 Memory, 43 Storage medium, 44 input unit, 45 output unit, 46 program, 50 host vehicle.

Claims

1. a surrounding illuminance information receiving unit that receives surrounding illuminance information related to surrounding illuminance, which is illuminance around the host vehicle, from a light receiving sensor provided in a vehicle interior of the host vehicle; a forward illuminance information receiving unit that receives forward illuminance information relating to forward illuminance, which is illuminance farther than the periphery of the host vehicle and forward in a traveling direction of the host vehicle; an outside illuminance information receiving unit that receives outside illuminance information relating to outside illuminance, which is illuminance farther than the periphery of the host vehicle and outside in a traveling direction of the host vehicle; a situation determination unit that determines a situation of the host vehicle based on the surrounding illuminance information, the forward illuminance information, or the outside illuminance information; a lighting control unit that controls turning on or off a headlight of the host vehicle according to the situation of the host vehicle determined by the situation determination unit; Equipped with the situation determination unit determines a situation of the host vehicle based on a map having the peripheral illuminance as one axis and at least one of the forward illuminance and the outer illuminance as another axis; The headlight control device, wherein the situation determination unit determines that a situation exists in which turning on of the headlights should be prohibited when the ambient illuminance is less than a predetermined value and the forward illuminance is equal to or greater than a predetermined value.

2. A surrounding illuminance information receiving unit that receives surrounding illuminance information relating to surrounding illuminance, which is illuminance around the host vehicle, from a light receiving sensor provided in a vehicle interior of the host vehicle; a forward illuminance information receiving unit that receives forward illuminance information relating to forward illuminance, which is illuminance farther than the periphery of the host vehicle and forward in a traveling direction of the host vehicle; an outside illuminance information receiving unit that receives outside illuminance information relating to outside illuminance, which is illuminance farther than the periphery of the host vehicle and outside in a traveling direction of the host vehicle; a situation determination unit that determines a situation of the host vehicle based on the surrounding illuminance information, the forward illuminance information, or the outside illuminance information; a lighting control unit that controls turning on or off a headlight of the host vehicle according to the situation of the host vehicle determined by the situation determination unit; Equipped with the situation determination unit determines a situation of the host vehicle based on a map having the peripheral illuminance as one axis and at least one of the forward illuminance and the outer illuminance as another axis; The headlight control device, wherein the situation judgment unit judges that the situation requires the headlights to be turned on when the ambient illuminance is equal to or greater than a predetermined value, the external illuminance is equal to or greater than a predetermined value, and the forward illuminance is less than a predetermined value.

3. A surrounding illuminance information receiving unit that receives surrounding illuminance information relating to surrounding illuminance, which is illuminance around the host vehicle, from a light receiving sensor provided in a vehicle interior of the host vehicle; a forward illuminance information receiving unit that receives forward illuminance information relating to forward illuminance, which is illuminance farther than the periphery of the host vehicle and forward in a traveling direction of the host vehicle; an outside illuminance information receiving unit that receives outside illuminance information relating to outside illuminance, which is illuminance farther than the periphery of the host vehicle and outside in a traveling direction of the host vehicle; a situation determination unit that determines a situation of the host vehicle based on the surrounding illuminance information, the forward illuminance information, or the outside illuminance information; a lighting control unit that controls turning on or off a headlight of the host vehicle according to the situation of the host vehicle determined by the situation determination unit; Equipped with the situation determination unit determines a situation of the host vehicle based on a map having the peripheral illuminance as one axis and at least one of the forward illuminance and the outer illuminance as another axis; The headlight control device, wherein the situation judgment unit judges that the headlights should be turned on when a first situation judged based on a first map having the peripheral illuminance as one axis and the forward illuminance as the other axis is not consistent with a second situation judged based on a second map having the peripheral illuminance as one axis and the outer illuminance as the other axis, and when either the first situation or the second situation is a situation in which the headlights should be turned on.

4. The headlamp control device according to claim 1 , wherein the forward illuminance information receiving unit receives the forward illuminance information relating to the forward illuminance based on a pupil diameter of a driver of the host vehicle.

5. 4. The headlamp control device according to claim 1, wherein the forward illuminance information receiving unit or the external illuminance information receiving unit receives the forward illuminance information or the external illuminance information relating to the forward illuminance or the external illuminance based on the brightness of an image captured by a forward camera that captures the view ahead of the vehicle.

6. The headlamp control device according to claim 5, wherein a forward area, which is an area farther away from the periphery of the vehicle and forward in the direction of travel of the vehicle, or an outer area, which is an area farther away from the periphery of the vehicle and outside in the direction of travel of the vehicle, is identified based on the line of sight of the driver of the vehicle and the brightness of the image.

7. The headlight control device according to claim 5, wherein a forward area, which is an area farther away from the periphery of the vehicle and forward in the direction of travel of the vehicle, or an outer area, which is an area farther away from the periphery of the vehicle and outside in the direction of travel of the vehicle, is identified based on map information, position information of the vehicle, and brightness of the image.

8. The headlamp control device according to claim 5, wherein a forward area, which is an area farther away from the periphery of the vehicle and forward in the direction of travel of the vehicle, or an outer area, which is an area farther away from the periphery of the vehicle and outside in the direction of travel of the vehicle, is identified based on position information of white lines and brightness of the image.

9. The headlamp control device according to claim 1 , wherein the lighting control unit adjusts brightness of an in-vehicle device of the host vehicle according to the situation of the host vehicle determined by the situation determination unit.