Headlamp 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

[Technical field]

[0001] The present disclosure relates to a headlamp control device that controls the headlamp of a host vehicle. [Background technology]

[0002] In conventional auto light systems, a light receiving sensor installed in the vehicle interior 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 surroundings in front of the vehicle are bright and automatically turns off the headlights, and if the illuminance falls below the threshold, the system determines that the surroundings in front of the vehicle are 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 in front of the vehicle, the outer area in the vehicle width direction, and the road area are set based on an image 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, running parallel to an overpass, or passing under an overpass (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 4937199 Summary of the Invention [Problem to be solved by the invention]

[0005] The new road transport vehicle safety standard, which requires the installation of an automatic light function after April 2020, stipulates that the headlights be turned on when the illuminance around the vehicle is less than 1000 Lx, and turned off when the illuminance around the vehicle exceeds 7000 Lx. According to this requirement, in the technology of Patent Document 1, even if the illuminance around the vehicle is sufficiently smaller than 1000 Lx, the headlights will be turned off if the area in front of the vehicle is bright. Conversely, even if the illuminance around the vehicle is sufficiently larger than 7000 Lx, the headlights will be turned on if the area in front of the vehicle is dark. This is because the auto light system uses only a specific threshold value to determine whether to turn on or off the headlights. Specifically, when the illuminance around the vehicle is sufficiently large or when the illuminance around the vehicle is sufficiently small, the headlights should be controlled taking into account the illuminance around the vehicle, but the judgment using the brightness of the image captured by the forward camera is prioritized. As a result, the lights will be turned on and off more than necessary, which may cause the driver to feel uncomfortable or may compromise driving safety.

[0006] In addition, in the technology of Patent Document 1, the brightness is determined based on the brightness of the road area in front of the vehicle, the outer area in the vehicle width direction, and the road area using an image captured by a forward camera. However, compared with illuminance, luminance is generally more susceptible to influences from the viewing direction, and to the reflectance of the material or color of the object on the illuminated surface, and errors are more likely to occur. Therefore, it is possible to control the headlights more accurately by comparing the brightness (illuminance) around the vehicle with the brightness (luminance) of the road area in front of the vehicle, the outer area in the vehicle width direction, and the road area using the same physical quantity, illuminance, rather than comparing them using different physical quantities.

[0007] As described above, in order to control the headlights with high accuracy, it is necessary to accurately judge the situation of the vehicle itself. However, the conventional techniques 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 is capable of accurately determining the situation of the host vehicle and controlling the headlights with high precision. [Means for solving the problem]

[0009] In order to solve the above problems, a headlamp control device according to the present disclosure includes an ambient illuminance information receiving unit that receives ambient illuminance information related to ambient illuminance, which is the illuminance around the host vehicle, from a light receiving sensor provided in the vehicle cabin of the host vehicle; a forward illuminance information receiving unit that receives forward illuminance information related to forward illuminance, which is the illuminance farther than the periphery of the host vehicle and forward in the traveling direction of the host vehicle; an outer illuminance information receiving unit that receives outer illuminance information related to outer illuminance, which is the illuminance farther than the periphery of the host vehicle and outside in the traveling direction of the host vehicle; a situation determination unit that determines a situation of the host vehicle based on the ambient illuminance information, the forward illuminance information, or the outer illuminance information; and a lighting control unit that controls turning on or off the headlamp of the host vehicle 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 in which the ambient illuminance is set as one axis and at least one of the forward illuminance and the outer illuminance is set as the other axis. The situation determination unit determines that the situation is such that 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. do. Effect of the Invention

[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. [Brief description of the drawings]

[0012] [Figure 1] 1 is a block diagram showing an example of an overall configuration including a headlamp control device according to an embodiment; [Diagram 2] FIG. 11 is a diagram for explaining setting of an area according to the embodiment. [Diagram 3]It is a block diagram showing an example of the hardware configuration of the headlight control device according to the embodiment. [Figure 4] It is a diagram for explaining the situation of passing under an overpass. [Diagram 5] It is a diagram for explaining the operation of the conventional auto-light system when passing under an overpass. [Figure 6] It is a diagram for explaining the operation of the headlight control device according to the embodiment when passing under an overpass. [Figure 7] It is a flowchart showing an example of the overall operation including the headlight control device according to the embodiment when passing under an overpass. [Figure 8] It is a diagram showing a map used for determination when passing under an overpass according to the embodiment. [Figure 9] It is a diagram for explaining the situation of running parallel under an overpass. [Figure 10] It is a flowchart showing an example of the overall operation including the headlight control device according to the embodiment when running parallel under an overpass. [Figure 11] It is a diagram showing a map used for determination when running parallel under an overpass according to the embodiment.

Embodiments for Carrying Out the Invention

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

[0014] The driver monitor 7 includes an in-vehicle camera 8, a near-infrared light emitting unit 9, a pupil diameter detecting unit 10, and a gaze direction detecting unit 11. The in-vehicle camera 8 is a camera that captures the inside of the vehicle interior, and captures at least the face of the driver. The near-infrared light emitting unit 9 emits near-infrared light when the in-vehicle camera 8 captures an image. The pupil diameter detecting unit 10 detects the pupil diameter of the driver from the image captured by the in-vehicle camera 8. The gaze direction detecting unit 11 detects the gaze direction of the driver from the image captured by the in-vehicle camera 8. In this way, in the driver monitor 7, when the in-vehicle camera 8 captures an image of the driver, the in-vehicle camera 8 receives the near-infrared light emitted by the near-infrared light emitting unit 9, thereby detecting the pupil diameter of the driver and the gaze direction of the driver.

[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 transmission unit 15 measures the luminance in the direction of travel of the vehicle and further away from the surroundings of the vehicle based on the image captured by the front camera 13, and converts it into illuminance. The forward illuminance information transmission unit 15 also transmits the converted illuminance to the headlamp control device 1. That is, the forward illuminance information transmission unit 15 transmits forward illuminance information related to the illuminance (forward illuminance) in the direction of travel of the vehicle and further away from the surroundings of the vehicle.

[0017] The outside illuminance information transmission unit 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 transmission unit 16 also transmits the converted illuminance to the headlamp control device 1. That is, the outside illuminance information transmission unit 16 transmits outside illuminance information related 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-precision locator 19 includes a vehicle position estimation unit 20, a high-precision 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 a signal received by the GNSS receiver 17, the speed of the vehicle measured by the vehicle speed sensor 18, and a high-precision map stored in the high-precision map data storage unit 21. The GNSS receiver 17 receives a signal related to the position of the vehicle from a GNSS satellite. 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 will acquire 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 transmission unit 25. The automatic light system 23 operates when an automatic light switch 31 is in an ON state, and stops operating when the automatic light switch 31 is in an 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 transmitting unit 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 transmitting unit 25 also transmits the measured illuminance around the vehicle to the headlamp control device 1. That is, the surrounding illuminance information transmitting unit 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, an ambient 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 outer illuminance information receiving unit 3 receives outer illuminance information transmitted by the outer 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 outer illuminance information receiving unit 3 may determine the outer illuminance, or the surrounding illuminance information receiving unit 4 may determine the surrounding illuminance.

[0025] The situation judgment unit 5 judges 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 according to the driving conditions of the vehicle determined by the condition determination unit 5. The lighting control unit 6 may also control the turning on, off, or light distribution of the sidelights 27, taillights 28, instrument panel 29, and navigation display 30 according to 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) farther away than the surroundings of the host vehicle and forward in the traveling direction of the host vehicle in the image area captured by the forward camera 13. The forward illuminance information transmission unit 15 obtains the illuminance (forward illuminance) of the area FA.

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

[0030] The area SA is an area (surrounding area) around the vehicle itself, the brightness of which is detected by the light receiving sensor 24 of the automatic light system 23. The surrounding illuminance information transmitting unit 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 a 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 receiver 2, the outside illuminance information receiver 3, the surrounding illuminance information receiver 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, which operates the hardware according to software.

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

[0035] The storage medium 43 is, 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 defines the content of the processing to be executed by the processor 41.

[0036] The input unit 44 is composed of, for example, a camera, a receiving unit, etc. The output unit 45 is composed of, for example, 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 makes it possible to realize each of the functions of the forward illuminance information receiver 2, the outer illuminance information receiver 3, the ambient illuminance information receiver 4, the situation determination unit 5, and the lighting control unit 6 in the headlamp control device 1.

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

[0039] <Operation of conventional automatic light systems when passing under an overpass> Fig. 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 headlights of the vehicle before, during, and after passing under the overpass and the surrounding illuminance of the vehicle (solid lines in the diagram). In Fig. 5, the horizontal axis shows time. Note that, for the sake of simplicity, Fig. 5 shows only the threshold value for lighting (the "lighting threshold value" shown by the dashed line in the diagram) as the threshold value for the surrounding illuminance, but in reality, the threshold values ​​for lighting and extinguishing are set separately.

[0040] Before passing under the overpass (from time 0 to time T1), the ambient illuminance is higher than the lighting threshold value. Therefore, the headlights of the host 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 continue to be turned on from time T3 until time T4, when the light-off operation time Toff by the automatic light system has elapsed. After that, the headlights of the vehicle are turned off at time T4.

[0043] When a vehicle passes under an overpass during the day as shown in Fig. 4, the conventional automatic light system shown in Fig. 5 automatically turns on the headlights because the unlit area under the overpass is dim, and 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 operation of turning the headlights on and off by the automatic light system causes discomfort to the driver.

[0044] <Operation of the headlamp control device according to the embodiment when passing under an overpass> Fig. 6 is a diagram for explaining the operation of the headlamp control device 1 according to the embodiment when passing under an overpass, and shows the relationship between the state of the headlamp 26 of the vehicle before passing under an overpass, during passing under an overpass, after passing under an overpass, and during night driving, and the surrounding illuminance of the vehicle (solid line in the figure) and the front illuminance of the vehicle (solid line in the figure). In Fig. 6, the horizontal axis shows time. Note that, for the sake of simplicity, Fig. 6 shows only the threshold value for turning on the vehicle (the "turning on threshold value" shown by the dashed line in the figure) as the threshold value for the surrounding illuminance, and only the threshold value for turning off the vehicle (the "turning off threshold value" shown by the dashed line in the figure) as the threshold value for the front illuminance, but in reality, multiple threshold values ​​are set by mapping the surrounding illuminance and the front illuminance.

[0045] Before passing under the overpass (from time 0 to time T5), the ambient illuminance is higher than the lighting threshold value. Therefore, the headlights 26 of the host 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, the headlights 26 of the vehicle are turned off from time T5 to time T6. Table 1 below shows the ambient illuminance, forward illuminance, and the state of the headlights 26.

[0047] [Table 1]

[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 host vehicle are turned off.

[0049] During night driving (after time T7), the ambient illuminance is lower than the turn-on threshold, and the forward illuminance is lower than the turn-off threshold. Therefore, the headlights 26 of the vehicle continue to be turned off from time T7 until time T8, when the turn-on operation time Ton by the automatic light system has elapsed. After that, the headlights 26 of the vehicle are turned on at time T8.

[0050] When the vehicle 50 passes under an overpass during the day as shown in Fig. 4, the conventional auto 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 passing under the overpass if the area after passing under the overpass is bright. This makes it possible to prevent the headlights 26 from being turned on unnecessarily, thereby reducing the 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, when 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. When the automatic light system 23 is in the ON state, the process proceeds to step S102. On the other hand, when the automatic light system 23 is not in the ON state (when 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 the 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.

[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 host vehicle from the forward camera 13.

[0055] In step S104, the forward illuminance information transmission unit 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). After that, the forward illuminance information transmission unit 15 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. Then, the situation determination unit 5 determines the traveling 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 traveling situation of the host vehicle based on the forward illuminance information, the surrounding illuminance information, and the map shown in FIG. 8. Details of the map shown in FIG. 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 host 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 state of the headlights 26 may be set to an initial value (for example, off) the first time.

[0060] In step S108, the situation determination unit 5 determines whether or not 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 one in which turning on the headlights 26 should be prohibited.

[0061] In step S109, the lighting control unit 6 performs control so as to turn on the headlights 26 in accordance with the result of the determination by the situation determination unit 5.

[0062] In step S110, the lighting control unit 6 performs control so as to turn off the headlights 26 in accordance with the result of the determination by the situation determination unit 5.

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

[0064] In FIG. 8, the vertical axis indicates the forward illuminance, and a threshold value TH1 is set. The horizontal axis indicates the surrounding illuminance, and threshold values ​​TH2, TH3, and TH4 are set. Three states of the headlamp 26, "on", "off", and "maintained on or off", are set by the threshold values ​​TH1 to TH4. These states correspond to the driving conditions of the host vehicle. The threshold values ​​TH1 to TH4 are changeable parameter values.

[0065] For example, the threshold value TH3 of the surrounding illuminance is set to 1000 Lx, which is a requirement of the new road vehicle safety standards. Similarly, the threshold value TH4 is set to 7000 Lx, which is a requirement of the new 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 surrounding illuminance is sufficiently low and the surroundings of the vehicle are clearly dark.

[0066] Moreover, the threshold value TH1 of the forward illuminance is set to a value (for example, 500 Lx) at which it is possible to determine that the forward area is sufficiently bright when the ambient illuminance 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] <Operation when running parallel under the elevated tracks> As shown in FIG. 9, the operation of the host vehicle 50 when it runs parallel 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 judges whether the automatic light system 23 is in the ON state. Specifically, when the automatic light switch 31 is in the ON state, the headlamp control device 1 judges that the automatic light system 23 is in the ON state. When the automatic light system 23 is in the ON state, the process proceeds to step S202. On the other hand, when the automatic light system 23 is not in the ON state (when 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 host vehicle. Specifically, the surrounding illuminance information transmission unit 25 measures the illuminance of the 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 illuminance information transmission unit 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). After that, the forward illuminance information transmission unit 15 transmits the forward illuminance information to the headlamp control device 1.

[0075] In step S206, the forward illuminance information receiving unit 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 or not the forward illuminance is equal to or less than a predetermined value based on the forward illuminance information received by the forward illuminance information receiving unit 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 determination unit 5 determines whether or not the surrounding illuminance is equal to or lower 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 lower than the predetermined value, the process proceeds to step S208. On the other hand, if the surrounding illuminance is equal to or lower than the predetermined value, the process proceeds to step S209.

[0077] In step S208, the situation determination unit 5 determines whether the surrounding illuminance is equal to or greater than a predetermined value based on the surrounding illuminance information received by the surrounding illuminance information receiving unit 4. If the surrounding illuminance is equal to or greater than the predetermined value, the process proceeds to step S210. On the other hand, if the surrounding 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 performs control so as to turn on the headlights 26 in accordance with the determination result of the situation determination unit 5.

[0079] In step S210, the lighting control unit 6 performs control so as to turn off the headlights 26 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 state of the headlights 26 may be set to an initial value (for example, off) the first time.

[0081] In step S212, the outside illuminance information transmission unit 16 calculates the illuminance of the outside area (outside illuminance). After that, the outside illuminance information transmission unit 16 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 host 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 for the first time.

[0085] In step S215, the situation determination unit 5 determines whether or not 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 performs control so as to turn on the headlights 26 in accordance with the result of the determination by the situation determination unit 5.

[0087] In step S217, the lighting control unit 6 performs control so as to turn off the headlights 26 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 indicates the external illuminance, and a threshold value TH5 is set. The horizontal axis indicates the peripheral illuminance, and threshold values ​​TH6, TH7, and TH8 are set. Three states of the headlights 26, "on", "off", and "maintained on or off", are set by the threshold values ​​TH5 to TH8. These states correspond to the driving conditions of the host vehicle. The threshold values ​​TH5 to TH8 are changeable parameter values.

[0090] For example, the threshold value TH6 of the surrounding illuminance is set to 1000 Lx, which is a requirement of the new road vehicle safety standards. Threshold value TH8 is also set to 7000 Lx, which is a requirement of the new safety standards. Threshold value TH7 is set to a value (e.g., 3000 Lx) to specify the area in which the auto light system suppresses turning off the headlights when the vehicle is traveling side by side under an overpass during the daytime, as the incident light from the outside area, which is sufficiently bright, illuminates the area under the overpass, making the area around the vehicle bright.

[0091] As shown in FIG. 9, when the vehicle runs parallel under an overpass during the day, the incident light from the sufficiently bright outer area illuminates the underpass, so that the surrounding area of ​​the vehicle becomes bright. In such a case, the conventional auto light system turns off the headlights. However, when the area ahead is dark, it may be better to turn on the headlights to ensure the visibility of the driver of the vehicle. In the headlight control device 1 according to the embodiment, by setting the threshold values ​​TH5 to TH8 as described above, when the surrounding illuminance is between the threshold value TH7 (3000 Lx) and the threshold value TH8 (7000 Lx) and the outer illuminance is greater than the threshold value TH5 (7000 Lx), the situation determination unit 5 determines that the vehicle runs parallel under an overpass. In this case, the lighting control unit 6 controls the headlights 26 to be turned on. This makes it possible to improve the comfort of the driver. That is, it is possible to accurately determine the situation of the vehicle and control the headlights 26 with high accuracy.

[0092] <Variation 1> The forward illuminance information receiving unit 2 may receive forward illuminance information relating to forward illuminance 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 pupil diameter of the driver from the image captured by the in-vehicle camera 8. Generally, the pupil diameter of a human pupil changes depending on the luminance in natural vision (a state in which no light is directly incident on the eye). Specifically, the higher the luminance, 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 forward area from the driver's pupil diameter 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 by using the driver's pupil diameter.

[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 transmission unit 15 may receive information on the driver's line of sight direction from the line of sight direction detection unit 11 of the driver monitor 7. In this case, the forward illuminance information transmission unit 15 calculates the forward illuminance based on the driver's pupil diameter when the driver's line of sight is directed in the same direction for a predetermined period of time or more, 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 the area in front of the vehicle.

[0097] Specifically, the forward illuminance information transmission unit 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 obtains the illuminance (forward illuminance) of the identified forward area. Similarly, the outer illuminance information transmission unit 16 obtains the illuminance (outer illuminance) of the outer area.

[0098] In this way, the forward illuminance and the external illuminance can be obtained by utilizing the brightness of the image captured in front of the vehicle.

[0099] In addition, for an image captured in front of the vehicle, a range of 20 degrees to the left and right from the front may be defined as the front area, and a range 70 degrees or more away to the left and right from 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 transmission unit 15 of the forward recognition unit 12 identifies the forward area based on the driver's line of sight direction received from the line of sight direction detection unit 11 of the driver monitor 7 and the brightness of the image of the area in front of the vehicle captured by the forward camera 13. Similarly, the outer illuminance information transmission unit 16 identifies the outer area.

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

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

[0104] Specifically, the forward illuminance information transmission unit 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 in front of the host vehicle captured by the forward camera 13. Similarly, the outer illuminance information transmission unit 16 identifies the outer area.

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

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

[0107] Specifically, the forward illuminance information transmission unit 15 of the forward recognition unit 12 identifies the forward area based on the position of the white line received from the white line detection unit 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 transmission unit 16 identifies the outer area.

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

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

[0110] When the brightness of the on-board device screen is adjusted to a darker level in bright conditions around the vehicle, the driver may find it difficult to recognize the displayed content. By adjusting the brightness of the on-board device according to the driving conditions of the vehicle as described above, the sense of incongruity caused by the brightness of the surroundings of the vehicle can be reduced.

[0111] <Variation 7> The situation determination unit 5 may determine that the headlights 26 should be turned on when a first situation determined based on a first map (map shown in FIG. 8) having peripheral illuminance as one axis and forward illuminance as the other axis does not match a second situation determined based on a second map (map shown in FIG. 11) having peripheral illuminance as one axis and outer illuminance as the other axis, and either the first situation or the second situation is a situation in which the headlights 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 each modified example may be freely combined, and the embodiments and each modified example 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. [Explanation of symbols]

[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 Width light, 28 Tail light, 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 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 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 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 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 does not match 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 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.

Images