Vehicle light control device, vehicle light control method, and recording medium with light control program recorded thereon

Abstract

The present invention is a vehicle light control device that, on the basis of surrounding environment information acquired by a surrounding environment recognition device, executes a light control at least including an on / off control of lights mounted on a vehicle and a lamp color switching control for switching the lighting colors of the lights. Said vehicle light control device comprises at least one processor including hardware. The processor performs an on-control of the lights when visibility as measured on the basis of the surrounding environment information becomes less than a first visibility. When performing the lamp color switching control of the lights when the visibility becomes less than a second visibility lower than the first visibility, the processor changes the start timing of the lamp color switching control according to the presence or absence of a preceding other vehicle, and relative conditions between the vehicle and the preceding other vehicle.

Description

Vehicle light control device, vehicle light control method, and recording medium recording a light control program

[0001] The present invention relates to a vehicle light control device for controlling lights mounted on a vehicle such as an automobile, a vehicle light control method, and a recording medium on which a light control program is recorded.

[0002] 2. Description of the Related Art Conventionally, vehicles such as automobiles are equipped with various types of lamps. These various lamps are appropriately controlled by a lamp control device in response to, for example, changes in the surrounding environment of the vehicle.

[0003] One example of various types of lighting mounted on a vehicle is a fog lamp, also known as a fog light. Fog lamps are used as auxiliary lighting for headlights and other lights when forward visibility is poor due to bad weather, such as fog, rain, snow, or a blizzard, and also serve as auxiliary lighting to alert surrounding vehicles to the presence of the vehicle. Fog lamps are illuminated in white or yellow, for example. Fog lamps used as auxiliary lighting for headlights are specifically referred to as front fog lamps.

[0004] Generally, when the fog lamps are illuminated in yellow, there are advantages in that they are more visible to the outside (other vehicles, etc.) and also make it easier to check the road conditions in the vicinity of the vehicle in bad weather conditions such as fog, rain, snow, blizzard, etc. Therefore, it has been found that in bad weather, it is more desirable to set the fog lamp illumination color to yellow rather than white.

[0005] On the other hand, white fog lamps have the advantage of being able to provide a high amount of light, so it is considered desirable to set the fog lamp color to white when relatively good long-distance visibility can be ensured even in bad weather.

[0006] In this way, by turning on the fog lamps, for example, in bad weather, the fog lamps not only ensure visibility but also have the function of notifying surrounding vehicles, such as preceding vehicles, following vehicles, and oncoming vehicles, of the presence of the vehicle.

[0007] Generally, fog lamps are designed to illuminate a wider area than headlights. For this reason, for example, driving with the fog lamps on during clear nighttime weather may have a negative impact on other vehicles in the vicinity. Furthermore, for example, if the fog lamps are too bright, they may also have a negative impact on other vehicles in the vicinity depending on weather conditions such as fog, rain, or snow.

[0008] Therefore, for example, Japanese Patent Application Laid-Open No. 2019-125372 discloses a vehicle lighting control device that controls the switching of fog lamps on and off depending on the surrounding environment (for example, weather conditions, etc.) Therefore, by controlling the fog lamps to be turned off on sunny days, it is possible to reduce the adverse effects of the fog lamps on other vehicles.

[0009] In addition, vehicle lighting control devices disclosed in Japanese Patent Application Laid-Open No. 5-278519, Japanese Patent Application Laid-Open No. 2008-213618, etc. control the light intensity of rear fog lamps according to weather conditions (light transmittance, etc.) and the distance between the vehicle and a following vehicle.

[0010] For example, in bad weather when the distance between the vehicle and the following vehicle is short, the light intensity of the rear fog lamps is controlled to be dimmed or the lamps are prohibited from being turned on, thereby reducing the impact of the rear fog lamps on the following vehicle.

[0011] Meanwhile, in recent years, various lamps mounted on vehicles, for example, those using light-emitting diodes (LEDs) as light source elements, have been put into practical use and are beginning to become widespread. Lamps using this type of LED have the advantage that the lighting color can be switched and controlled.

[0012] Therefore, for example, the vehicle lighting control device disclosed in Patent Publication No. 2021-114463 performs lighting control such as switching the headlight color from white to yellow depending on weather conditions, etc., to turn on the headlights as fog lights.

[0013] As described above, in the past, as shown in the above-mentioned publications, various disclosures have been made regarding lighting control, such as dimming or turning off the illumination light, depending on the surrounding environment (weather conditions, distance to other vehicles in the vicinity, etc.).

[0014] However, when controlling lights during bad weather, for example, it is required to perform light control that takes into account even more detailed conditions, thereby achieving more accurate, better, and more appropriate light control.

[0015] An object of the present invention is to provide a vehicle light control device, a vehicle light control method, and a recording medium having a light control program recorded thereon, which can contribute to improving safety when driving a vehicle in bad weather.

[0016] In order to achieve the above-mentioned object, one embodiment of the present invention is a vehicle lighting control device that performs lighting control including at least on / off control of lights mounted on the vehicle and light color switching control that switches the lighting color of the lights based on surrounding environment information acquired by a surrounding environment recognition device, and is equipped with one or more processors including hardware, and the processor controls the lights to turn on when the visibility measured based on the surrounding environment information becomes less than a first visibility, and when the visibility becomes less than a second visibility at which visibility is lower than the first visibility, changes the start timing of the light color switching control depending on whether or not there is another vehicle ahead, or the relative situation between the vehicle and the other vehicle ahead.

[0017] One embodiment of the present invention is a vehicle light control method that performs light control that includes at least on / off control of lights mounted on the vehicle and light color switching control that switches the light color of the lights based on surrounding environment information acquired by a surrounding environment recognition device, and when the visibility measured based on the surrounding environment information becomes less than a first visibility, the lights are turned on, and when the visibility becomes less than a second visibility that is lower than the first visibility, the light color switching control is performed, and the start timing of the light color switching control is changed depending on whether or not there is another vehicle ahead, or the relative situation between the vehicle and the other vehicle ahead.

[0018] A recording medium having recorded thereon a light control program of one embodiment of the present invention has recorded thereon a light control program that causes a computer to execute the following processes: measuring visibility based on ambient environment information, and when the measured visibility falls below a first visibility, controlling the lights to be on; and when the visibility falls below a second visibility at which visibility is lower than the first visibility, changing the start timing of the light color switching control for the lights depending on whether or not there is another vehicle ahead or the relative situation between the vehicle and the other vehicle ahead.

[0019] According to the present invention, it is possible to provide a vehicle light control device, a vehicle light control method, and a recording medium having a light control program recorded thereon, which can contribute to improving safety when driving a vehicle in bad weather.

[0020] A block diagram showing a schematic configuration of a vehicle control device including a vehicle light control device according to one embodiment of the present invention. A flowchart showing a part of the operation of a vehicle control device including a vehicle light control device according to one embodiment of the present invention. A subroutine of a first modified example of the operation of a vehicle control device including a vehicle light control device according to one embodiment of the present invention. A diagram showing a part of a flowchart of a second modified example of the operation of a vehicle control device including a vehicle light control device according to one embodiment of the present invention.

[0021] The present invention will be described below with reference to the illustrated embodiments. The drawings used in the following description are schematic, and the dimensional relationships and scales of the components may be different for each component in order to show each component at a size that allows it to be recognized on the drawing. Therefore, the present invention is not limited to the illustrated embodiments in terms of the number of components shown in the drawings, the shapes of the components, the size ratios of the components, the relative positional relationships of the components, and so on.

[0022] First, the schematic configuration of a vehicle control device including a vehicle light control device according to one embodiment of the present invention will be briefly described below with reference to Fig. 1. Fig. 1 is a block diagram showing the schematic configuration of a vehicle control device including a vehicle light control device according to one embodiment of the present invention.

[0023] In order to avoid cluttering the drawing, only components directly related to the present invention are shown in Fig. 1, and other components are omitted. In the following description, only the main components directly related to the present invention will be described in detail.

[0024] The configuration of the vehicle control device including the vehicle lighting control device of this embodiment is basically similar to that of a conventional vehicle control device of the same type.

[0025] The vehicle control device 1 includes a camera unit 10, a control unit 20, various sensors (described in detail below; 14, 15), various control units (described in detail below; 21, 22), and the like.

[0026] The camera unit 10 is an in-vehicle camera device fixed to the upper center portion of the front interior of a vehicle (hereinafter referred to as the host vehicle; not shown) equipped with the vehicle control device 1. The camera unit 10 is configured to include a stereo camera 11, an image processing unit (hereinafter abbreviated as IPU) 12, an image recognition unit (image recognition ECU; Electronic Control Unit) 13, etc.

[0027] The stereo camera 11 is formed with two cameras, a main camera 11a and a sub-camera 11b. The main camera 11a and the sub-camera 11b are arranged, for example, in symmetrical positions with respect to the center of the vehicle width direction in the cabin of the vehicle, facing forward (in the direction of travel) of the vehicle. Each of the main camera 11a and the sub-camera 11b is composed of, for example, an imaging optical system, an imaging element such as a CMOS image sensor, and a processing circuit for processing imaging signals, etc.

[0028] With this configuration, the stereo camera 11 acquires two image data from two different viewpoints of the surrounding environment in a predetermined range ahead of the vehicle using the main camera 11a and the sub-camera 11b at a predetermined imaging period that is synchronized with each other. Then, stereo image data is generated based on the two image data acquired in this manner. This stereo image data is surrounding environment information that represents the surrounding environment while the vehicle is traveling. The surrounding environment information (image data) generated by the stereo camera 11 is output to the IPU 12.

[0029] The IPU 12 is a circuit unit that performs predetermined image processing on the surrounding environment information (image data) acquired by the stereo camera 11. The IPU 12 performs processing to detect the edges of various objects, such as objects depicted in the image, road markings, or boundary lines (hereinafter abbreviated as "marking lines") marked on the road surface or parking lot premises. Through this processing, the IPU 12 recognizes three-dimensional objects and marking lines around the vehicle. Furthermore, the IPU 12 acquires distance information from the positional deviation of corresponding edges in the left and right images based on the stereo image data, and generates image information (distance image information) including the distance information. The distance image information generated by the IPU 12 is output to the image recognition unit 13.

[0030] The image recognition unit 13 calculates the road curvature [1 / m] of the left and right dividing lines of the road on which the vehicle is traveling (the vehicle's traveling path) and the width between the left and right dividing lines (lane width), based on the distance image information and the like input from the IPU 12. Various well-known methods are used to calculate the road curvature and lane width.

[0031] In addition, the image recognition unit 13 performs predetermined pattern matching on the distance image information to recognize three-dimensional objects such as guardrails and curbs extending along the road and other vehicles in the vicinity, as well as the condition of the road surface (hereinafter referred to as road surface conditions, etc.).

[0032] Here, the recognition of three-dimensional objects by the image recognition unit 13 includes, for example, the type of three-dimensional object, the height of the three-dimensional object, the width of the three-dimensional object, the distance to the three-dimensional object, the speed of the three-dimensional object, the relative speed between the three-dimensional object and the vehicle, the relative distance between three-dimensional objects (for example, the lateral distance between a curb on the road edge and a nearby dividing line), etc. In addition, the road surface conditions, etc., are recognized, for example, whether the road surface is wet due to rain or melting snow, rainfall, snow accumulation, packed snow, or frozen road surface.

[0033] The various types of information recognized by the image recognition unit 13 are output as first surrounding environment information to the control unit 20. Therefore, the camera unit 10 functions as a surrounding environment recognition device that recognizes the surrounding environment around the vehicle.

[0034] The control unit 20 is a configuration unit or circuit unit that comprehensively controls the entire vehicle control device 1. Various control units, such as a light control unit 21 and an operation input control unit 22, are connected to the control unit 20 via an in-vehicle communication line such as a CAN (Controller Area Network).

[0035] Note that various control units other than the light control unit 21 and the operation input control unit 22 shown in FIG. 1 are also connected to the control unit 20, but since these control units are not directly related to the present invention, they will not be shown or described here.

[0036] The light control unit 21 is a circuit unit and a light control device that performs various controls on various lights 31 mounted on the vehicle. For this purpose, the light control unit 21 is connected to the various lights 31.

[0037] The various types of lights 31 include, for example, illuminating lights, signal marker lights, and indicator lights. Among these, illuminating lights include, for example, headlights, front and rear fog lights, side lights, license plate lights, back-up lights, and interior lights. Furthermore, signal marker lights include, for example, turn signals (blinkers or turn lamps), brake lights, tail lights, parking lights, side lights (low beam lights), and automatic driving indicator lights. Furthermore, indicator lights include, for example, indicator lights for meters, switches, air conditioning, audio equipment, and the like.

[0038] For example, the lighting control unit 21 performs various lighting controls, such as switching fog lamps and the like on or off (on or off) depending on the surrounding environment of the vehicle (weather, surrounding conditions of other vehicles nearby, etc.), changing the timing of lighting, switching the lighting color, and also controlling the on / off of automatic driving marker lights.

[0039] Here, among the light controls performed by the light control unit 21, the light color switching control is, for example, a control for switching the lighting color of the front fog lamps between white and yellow at any timing.

[0040] For this purpose, for example, light-emitting diodes (LEDs) are used as the front fog lamps included in the lamps 31. The front fog lamps can be controlled by the light control unit 21 to switch their illumination color between white and yellow.

[0041] The operation input control unit 22 is a component or circuit unit that receives instruction signals from a plurality of various operation input members 32 arranged inside the vehicle and transmits them to the control unit 20. In response to these signals, the control unit 20 outputs appropriate control instructions to the component units corresponding to the received instruction signals. To this end, the operation input control unit 22 is connected to a plurality of various operation input members 32 arranged inside the vehicle.

[0042] The operation input member 32 may be, for example, a plurality of switches for issuing instructions to execute various driving assistance controls, mode selector switches for switching driving modes (manual driving mode, automatic driving mode, etc.), etc. Other examples of the operation input member 32 include a steering touch sensor that detects the driver's steering state, a driver monitoring system (DMS) that detects the driver's face authentication and line of sight, etc., an in-vehicle monitor system including an in-vehicle camera that recognizes the riding status of passengers including the driver, a touch panel display input device, various meters, etc.

[0043] The operation input control unit 22 outputs input information such as various operation instructions (on / off instructions, etc.) input by the driver using the operation input member 32 to the control unit 20 .

[0044] In addition, the control unit 20 is connected to various sensors such as an on-board radar device 14 and a locator unit 15 .

[0045] The onboard radar device 14 is composed of multiple sensors, such as multiple millimeter-wave radars. The multiple millimeter-wave radars detect three-dimensional objects, primarily pedestrians and vehicles traveling alongside, as well as structures (e.g., curbs, guardrails, building walls, plants, and other three-dimensional objects) located on the edge of the road (e.g., the edge of the shoulder) by receiving and analyzing reflected waves from objects in response to output radio waves. Furthermore, the multiple millimeter-wave radars also detect three-dimensional obstacles on the road. In this case, the multiple millimeter-wave radars detect specific information about the three-dimensional object, such as the width of the three-dimensional object, the position of a representative point of the three-dimensional object (relative position and distance to the vehicle), and the relative speed.

[0046] The onboard radar device 14 includes a plurality of sensors (such as a plurality of millimeter-wave radars) disposed, for example, on the left and right sides of the front bumper (referred to as front left and right side sensors) and on the left and right sides of the rear bumper (referred to as rear left and right side sensors). The front left and right side sensors detect, as second surrounding environment information, three-dimensional objects present in areas diagonally forward and to the left and right of the vehicle, which are difficult to recognize in images from the stereo camera 11. The rear left and right side sensors detect, as second surrounding environment information, three-dimensional objects present in areas diagonally forward and to the left and right of the vehicle, which are difficult to recognize with the front left and right side sensors.

[0047] In this way, the on-board radar device 14 functions as a surrounding environment recognition device that recognizes the surrounding environment of the vehicle. Information acquired by each sensor of the on-board radar device 14 is sent to the control unit 20.

[0048] The locator unit 15 includes a GNSS sensor 15a and a high-precision road map database (road map DB) 15b.

[0049] The GNSS sensor 15a receives positioning signals transmitted from a plurality of positioning satellites to determine the position (latitude, longitude, altitude, etc.) of the vehicle.

[0050] The road map DB 15b is a large-capacity storage medium such as a hard disk drive (HDD) or a solid state drive (SSD), and stores high-precision road map information (dynamic map). This road map DB 15b stores lane data required for autonomous driving, such as lane width data, lane center position coordinate data, lane heading angle data, and speed limits. This lane data is stored at intervals of several meters for each lane on the road map.

[0051] Locator unit 15 can also acquire real-time information about the surrounding environment at the vehicle position measured by GNSS sensor 15 a (e.g., traffic congestion information, weather information, etc.) by communicating with an external system (not shown). In this case, the weather information includes, for example, information about the occurrence of snowfall in the area including the vehicle position, rainfall information, snowfall information, snow accumulation information, temperature and humidity information, etc.

[0052] Then, for example, based on a request signal from the control unit 20, the road map DB 15b outputs road map information of a set range based on the vehicle position measured by the GNSS sensor 15a as third surrounding environment information to the control unit 20. In this way, the locator unit 15 has a function as a surrounding environment recognition device that recognizes the surrounding environment around the vehicle.

[0053] The control unit 20 controls the vehicle's running based on the information acquired by the various sensors. The control unit 20 also controls the lighting of the lights 31 as needed based on the surrounding environment information recognized by the camera unit 10, the on-board radar device 14, the locator unit 15, etc.

[0054] All or part of the image recognition unit 13, the control unit 20, the locator unit 15, the light control unit 21, the operation input control unit 22, etc. are configured by a processor including hardware.

[0055] Here, the processor is composed of a well-known configuration including, for example, a central processing unit (CPU), a random access memory (RAM), a read-only memory (ROM), a non-volatile memory, a non-volatile storage, a non-transitory computer readable medium, and peripheral devices thereof.

[0056] Software programs to be executed by the CPU and fixed data such as data tables are stored in advance in ROM, nonvolatile memory, nonvolatile storage devices, etc. The CPU reads out the software programs stored in ROM, etc., expands them into RAM, and executes them. The software programs also refer to various data, etc. as appropriate, thereby realizing the functions of the above-mentioned components and components units (13, 14, 15, 21, 22), etc.

[0057] The processor may be configured by a semiconductor chip such as an FPGA (Field Programmable Gate Array), etc. The above-mentioned components and units (13, 14, 15, 21, 22) may be configured by electronic circuits.

[0058] Furthermore, the software program may be in a form in which it is recorded in whole or in part as a computer program product on a portable disk medium such as a flexible disk, CD-ROM, or DVD-ROM, or on a non-transitory computer readable medium such as a card-type memory, HDD (Hard Disk Drive) device, or SSD (Solid State Drive) device.

[0059] The operation of the vehicle control device 1 including the vehicle light control device of this embodiment configured as described above will be described below with reference to Fig. 2. Fig. 2 is a flowchart showing part of the operation of the vehicle control device including the vehicle light control device of this embodiment.

[0060] In detail, FIG. 2 shows the fog lamp light control process that is performed in accordance with the surrounding environment while a vehicle equipped with a vehicle control device 1 including the light control device (light control unit 21) of this embodiment is traveling on a road or the like.

[0061] First, it is assumed that a vehicle equipped with the vehicle control device 1 including the light control unit 21 of this embodiment is traveling on a road or the like (not shown).

[0062] At this time, in step S11 of Fig. 2, the control unit 20 continues traveling while recognizing the surrounding environment of the vehicle based on surrounding environment information acquired from time to time using the surrounding environment recognition device (10, 14, 15, etc.). The surrounding environment recognition process executed here is a well-known process that is generally performed in conventional vehicle control devices.

[0063] In step S12, the control unit 20 checks the weather conditions around the vehicle while it is traveling. Here, bad weather conditions are assumed to be, for example, foggy conditions, rainy conditions, or snowy conditions accompanied by a snowstorm. In other words, bad weather conditions are assumed to be conditions in which it is appropriate to drive with the vehicle's lights 31, for example, the fog lamps, turned on.

[0064] Specifically, for example, in step S12 , the control unit 20 measures the visibility ahead of the vehicle based on the image information acquired by the camera unit 10 .

[0065] Here, visibility refers to the distance to a clearly visible object ahead of the vehicle (e.g., another preceding vehicle, etc.) Visibility is calculated, for example, by measuring the distance to a clearly visible object ahead of the vehicle based on stereo image information acquired by camera unit 10.

[0066] If it is confirmed in the process of step S12 that the measured visibility is less than the first visibility (for example, 200 meters (m)), it is determined that the weather conditions are bad, and the process proceeds to the process of step S13. On the other hand, if it is confirmed that the measured visibility is equal to or greater than the first visibility, it is determined that the weather conditions are good (or that the weather conditions have improved), and the process proceeds to the process of step S14. In the process of step S12, it is confirmed whether the visibility has decreased below a predetermined threshold (first visibility).

[0067] Next, in step S14, the control unit 20 checks whether the fog lamps among the lamps 31 are on or not through the light control unit 21. If it is confirmed that the fog lamps are on, the process proceeds to step S15. If it is not confirmed that the fog lamps are on (they are off), the process returns to step S11.

[0068] In step S15, the control unit 20 executes a light control process to turn off the fog lamps among the lamps 31 via the light control unit 21. Thereafter, the process returns to step S11.

[0069] Meanwhile, in step S13, the control unit 20 checks whether the fog lamps are on, similar to the process in step S14 described above. If it is confirmed that the fog lamps are on (ON), the process proceeds to step S16. If it is not confirmed that the fog lamps are on (OFF), the process proceeds to step S17.

[0070] In step S17, the control unit 20 executes a light control process to turn on the fog lamps among the lamps 31 in white lighting color via the light control unit 21. Then, the process proceeds to step S19.

[0071] On the other hand, in step S16, the control unit 20 checks via the light control unit 21 whether the lighting color of the fog lamps that are turned on among the lamps 31 is yellow. If it is confirmed that the lighting color of the fog lamps is yellow, the process proceeds to step S18. If it is confirmed that the lighting color of the fog lamps is not yellow (is white), the process proceeds to step S19.

[0072] In step S18, the control unit 20 executes a light control process to change the lighting color of the fog lamps, among the lamps 31, from yellow to white via the light control unit 21. Thereafter, the process proceeds to step S19.

[0073] In step S19, the control unit 20 measures the visibility ahead of the vehicle based on the image information acquired by the camera unit 10. If it is determined that the measured visibility is less than the second visibility (for example, 150 meters (m)), the process proceeds to step S20. If it is determined that the measured visibility is equal to or greater than the second visibility, the process returns to step S12. In step S19, it is determined whether the visibility has decreased below a predetermined threshold (second visibility).

[0074] In step S20, the control unit 20 checks whether or not there is another vehicle ahead based on information acquired by the camera unit 10 or the on-board radar device 14. If the presence of another vehicle ahead is confirmed, the process proceeds to step S21. If the presence of another vehicle ahead is not confirmed, the process proceeds to step S22.

[0075] In step S21, the control unit 20 checks the relative situation between the host vehicle and the other preceding vehicle based on information acquired by the camera unit 10 or the on-board radar device 14. The relative situation between the host vehicle and the other preceding vehicle is, for example, the distance from the host vehicle to the other preceding vehicle, the approach speed of the host vehicle to the other preceding vehicle, or the width size (length) or rear size (area) of the other preceding vehicle.

[0076] Here, the distance to the other preceding vehicle, the approach speed to the other preceding vehicle, the width size or rear size of the other preceding vehicle, etc. can be calculated using various sensors, such as the camera unit 10.

[0077] Therefore, in the processing of step S21, the control unit 20 checks whether the distance from the vehicle to the preceding vehicle is shorter than a predetermined distance, whether the speed at which the vehicle is approaching the preceding vehicle is higher than a predetermined speed, and whether the width size or rear size of the preceding vehicle is larger than a predetermined size.

[0078] The threshold values ​​for the predetermined distance from the own vehicle to the other preceding vehicle, the approach speed of the own vehicle to the other preceding vehicle, and the width size or rear size of the other preceding vehicle are set to predetermined values ​​as appropriate.

[0079] Here, in any case where the distance from the own vehicle to the other preceding vehicle is shorter than a predetermined distance, or the own vehicle's approach speed to the other preceding vehicle is high, or the other preceding vehicle has a large width size or rear size, it is desirable to make the other preceding vehicle aware of the presence of the own vehicle, which will be the following vehicle, as early as possible.

[0080] For example, it is known that the shorter the distance from the host vehicle to the preceding vehicle, or the higher the host vehicle's approach speed to the preceding vehicle, the greater the risk of collision between the host vehicle and the preceding vehicle. Therefore, the preceding vehicle desires to be aware of the presence of the host vehicle as soon as possible.

[0081] Furthermore, if the preceding vehicle has a large width or rearward dimension, i.e., if the preceding vehicle is a large vehicle, the amount of raindrops or snow smoke kicked up by the wheels of the preceding vehicle will be considerable, which will tend to reduce rearward visibility for the preceding vehicle and forward visibility for the following vehicle.

[0082] Therefore, in the light control unit 21 of this embodiment, when the presence of a preceding vehicle is confirmed, if the preceding vehicle is close, if the approaching speed to the preceding vehicle is high, or if the preceding vehicle is large, the timing of controlling the fog lamps to change from white to yellow is set earlier. This allows the preceding vehicle to quickly become aware of the presence of the vehicle, which is the following vehicle. That is, in bad weather conditions, the lower the visibility, the more yellow it is desirable for the fog lamps to be illuminated.

[0083] 2, if any of the three situations described above is met in step S21, the process proceeds to step S23. If none of the three situations is met, the process proceeds to step S24.

[0084] Then, in step S23, the control unit 20 executes a light control process to change the lighting color of the fog lamps among the lamps 31 from white to yellow via the light control unit 21. Thereafter, the process returns to step S11.

[0085] Meanwhile, in step S24, the control unit 20 measures the visibility ahead of the vehicle based on the image information acquired by the camera unit 10. If it is determined that the visibility is less than a third visibility (for example, 100 meters (m)), the process proceeds to step S23. If it is determined that the visibility is equal to or greater than the third visibility, the process returns to step S12. That is, in step S21, it is determined whether the visibility has decreased below a predetermined threshold (third visibility). If the visibility has decreased below the predetermined threshold (third visibility), the process of step S23 (light color switching control process [from white to yellow]) is executed.

[0086] On the other hand, if the presence of a preceding vehicle is not confirmed in the processing of step S20 and the process proceeds to step S22, the control unit 20 measures the visibility ahead of the host vehicle based on the image information acquired by the camera unit 10 in step S22. If it is confirmed that the visibility is less than a fourth visibility (e.g., 50 meters (m)), the process proceeds to step S23. If it is confirmed that the visibility is equal to or greater than the fourth visibility, the process returns to step S20. That is, in the processing of step S22, it is confirmed whether the visibility has decreased below a predetermined threshold (fourth visibility). If the visibility has decreased below the predetermined threshold (fourth visibility), the process of step S23 (light color switching control process [from white to yellow]) is executed.

[0087] In this embodiment, the predetermined visibility thresholds are exemplified as a first visibility, a second visibility, a third visibility, and a fourth visibility. In this case, the predetermined thresholds are set to values ​​that decrease visibility in the order of the first visibility, the second visibility, the third visibility, and the fourth visibility (first visibility > second visibility > third visibility > fourth visibility).

[0088] Specifically, the first visibility is, for example, less than 200 meters, the second visibility is, for example, less than 150 meters, the third visibility is, for example, less than 100 meters, and the fourth visibility is, for example, less than 50 meters.

[0089] Generally, the standard visibility for dense fog, etc. is defined as 200 meters, and the numerical settings above are given as examples based on this definition. However, these setting values ​​are not limited to the example values ​​and can be set as appropriate.

[0090] As described above, according to the embodiment, when a vehicle is driven under conditions where visibility is reduced due to bad weather or the like, lighting control is performed to switch the fog lamp color from white to yellow in accordance with the results of recognition of the surrounding environment.

[0091] In this case, if the presence of another vehicle ahead is confirmed, the timing for starting the light color change control is changed depending on the condition of the other vehicle ahead (for example, the distance from the vehicle to the other vehicle ahead, the approaching speed of the vehicle ahead to the other vehicle ahead, or the width size of the other vehicle ahead, etc.).

[0092] That is, when the distance from the vehicle to the preceding vehicle is short, when the vehicle approaches the preceding vehicle at a high speed, or when the preceding vehicle is large in width, the light color change process is performed early.

[0093] Such lighting control can contribute to improving the visibility of the surroundings of the vehicle. At the same time, it can make the surroundings (especially other vehicles ahead) more aware of the presence of the vehicle. Therefore, this can contribute to ensuring the driving safety of the vehicle and other surrounding vehicles.

[0094] 2 (white-to-yellow light color switching control process) is a process for simply switching the light color. However, when the light color switching control process is executed, a processing step (alternating light color lighting process) as shown in FIG. 3 may be added.

[0095] Figure 3 shows a first modified example of the operation of a vehicle control device including the vehicle lighting control device of this embodiment, and is a subroutine including a light color alternating lighting processing step executed during the processing of step S23 in Figure 2 (light color switching control processing [switching from yellow to white]).

[0096] In this first variant, at the timing of switching from white to yellow light color control processing, a predetermined light color switching control is performed to more clearly notify other vehicles in the vicinity that the light color has changed.

[0097] 3, the light control unit 21 checks whether or not a switch instruction signal for switching the lighting color of the fog lamps that are currently turned on has been received from the control unit 20. If a light color switch instruction signal has been received, the process proceeds to step S32. If a light color switch instruction signal has not been received, the process exits (returns).

[0098] In step S32, the control unit 20 starts the execution of a light control process in which the light control unit 21 switches the lighting color of the fog lamps, among the lights 31, from white to yellow.

[0099] In the process of step S32, the light control unit 21 first switches the illumination color of the currently lit fog lamp from white to yellow. Then, after switching the illumination color, the yellow illumination continues for a predetermined time (e.g., several seconds). After the predetermined time (several seconds) has elapsed, the illumination color is switched from yellow to white, and the white illumination continues for a similar predetermined time (e.g., several seconds). In this way, the yellow illumination and the white illumination are alternately switched for a predetermined time (e.g., several seconds each) a predetermined number of times (e.g., five times each). Then, the process proceeds to step S33.

[0100] Subsequently, in step S33, the control unit 20 causes the fog lamps among the lamps 31 to continue to light in yellow through the light control unit 21. Thereafter, the series of processes ends (return).

[0101] In this way, for example, under conditions where visibility is reduced due to bad weather or the like, when the process of step S23 in FIG. 2 (light color switching process) is performed, the addition of the light color alternating process (processing steps of steps S32 and S33 in FIG. 3) can contribute to making the presence of the host vehicle more clearly recognized by the surroundings (especially other vehicles ahead, etc.). At the same time, substantially the same effects as those of the first embodiment described above can be obtained. This can further contribute to ensuring the driving safety of the host vehicle and other vehicles in the vicinity.

[0102] In addition, in this process, the illumination color is alternately switched between yellow and white, so that the area ahead of the vehicle can be continuously illuminated. This allows the vehicle to continuously ensure forward visibility. At the same time, other preceding vehicles can continuously recognize the vehicle.

[0103] Furthermore, the alternating light color lighting process (the process step shown in step S32 in FIG. 3) is not limited to the above-described form. For example, the alternating light color lighting process can be applied even in the following example situation.

[0104] FIG. 4 shows a second modified example of the operation of a vehicle control device including the vehicle light control device of this embodiment, and shows an alternating light color lighting processing step added after the processing of step S23 in FIG.

[0105] In this second variant, when the vehicle is traveling with its fog lamps illuminated in yellow and it is detected that the vehicle is approaching another vehicle ahead, the alternating light color illumination process is executed.

[0106] First, after the process of step S23 in Fig. 2, the process proceeds to step S41 in Fig. 4. In step S41, the control unit 20 checks whether the host vehicle is approaching the preceding vehicle based on information acquired by the camera unit 10 or the on-board radar device 14. If it is confirmed that the host vehicle is approaching the preceding vehicle within a predetermined distance, the process proceeds to the next step S42. If the host vehicle is further away from the preceding vehicle than the predetermined distance, the processes of steps S42 and S43 in Fig. 4 are skipped. Then, the process returns to step S11 in Fig. 2.

[0107] In step S42, the control unit 20 switches the illumination color of the currently lit fog lamps from yellow to white. Then, after switching the illumination color, the white illumination continues for a predetermined time (e.g., several seconds). After the predetermined time (e.g., several seconds) has elapsed, the illumination color is switched from white to yellow, and the yellow illumination continues for a similar predetermined time (e.g., several seconds). In this way, the yellow and white illuminations are alternately turned on for a predetermined time (e.g., several seconds each) a predetermined number of times (e.g., five times each). Then, the process proceeds to step S43.

[0108] Subsequently, in step S43, the control unit 20 causes the fog lamps, among the lamps 31, to continue to light in yellow via the light control unit 21. Thereafter, the process returns to step S11.

[0109] The processes in steps S42 and S43 in FIG. 4 are the same as the processes in steps S32 and S33 in FIG.

[0110] In this way, for example, under conditions where visibility is reduced due to bad weather or the like, if the approach of the host vehicle to a preceding vehicle is detected while the fog lamps are lit in yellow after the process of step S23 in FIG. 2 (light color switching process), the additional process of alternating light colors (processing steps shown in steps S42 and S43 in FIG. 4) can be added to contribute to making the presence of the host vehicle more clearly visible to the surroundings (especially the preceding vehicle, etc.). At the same time, effects substantially similar to those of the first embodiment described above can be obtained. This can further contribute to ensuring the driving safety of the host vehicle and surrounding vehicles.

[0111] The present invention is not limited to the above-described embodiments, and various modifications and applications can be made without departing from the spirit and scope of the invention. Furthermore, the above-described embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining the disclosed multiple constituent elements. For example, if the problem to be solved by the invention can be solved and the effects of the invention can be obtained even if some constituent elements are deleted from all the constituent elements shown in one embodiment, the configuration from which these constituent elements are deleted can be extracted as the invention. Furthermore, constituent elements from different embodiments may be appropriately combined. The present invention is not limited by specific embodiments other than as limited by the appended claims.

Claims

1. A vehicle lighting control device that performs lighting control, including at least on / off control of lights mounted on the vehicle and light color switching control to switch the lighting color of the lights, based on surrounding environment information acquired by a surrounding environment recognition device, and is equipped with one or more processors including hardware, wherein the processor controls the lights to turn on when the visibility measured based on the surrounding environment information falls below a first visibility, and when the visibility falls below a second visibility that is lower than the first visibility, changes the start timing of the light color switching control depending on whether or not there is another vehicle ahead, or the relative situation between the vehicle and the other vehicle ahead.

2. The vehicle lighting control device according to claim 1, characterized in that the surrounding environment recognition device is a camera unit, the camera unit includes a stereo camera device, and the surrounding environment information acquired by the surrounding environment recognition device is distance image information.

3. The vehicle lighting control device according to claim 1, wherein the lighting devices mounted on the vehicle include at least fog lamps.

4. A vehicle lighting control device according to claim 1, characterized in that the lighting color switching control performs lighting control to switch the lighting color of the lamps between white lighting and yellow lighting.

5. A vehicle lighting control device as described in claim 1, characterized in that the light color switching control turns on the lights in white when the visibility is less than the first visibility range, and turns on the lights in yellow when the visibility is less than the second visibility range.

6. A vehicle lighting control device as described in claim 1, characterized in that the relative situation between the subject vehicle and the preceding vehicle is at least the distance between the subject vehicle and the preceding vehicle, or the approach speed of the subject vehicle to the preceding vehicle, or the width size or rear area of ​​the preceding vehicle.

7. A vehicle light control device as described in claim 6, characterized in that when the visibility falls below a second visibility where visibility is lower than the first visibility and light color change control is performed, if the presence of the other preceding vehicle is detected, the light color change control of the lights is performed immediately if the distance between the host vehicle and the other preceding vehicle is short, or if the host vehicle's approaching speed towards the other preceding vehicle is high, or if the other preceding vehicle has a large width or rear area; if the distance between the host vehicle and the other preceding vehicle is not short, or if the host vehicle's approaching speed towards the other preceding vehicle is high, or if the other preceding vehicle has a large width or rear area, the light color change control of the lights is performed when the visibility falls below a third visibility where visibility is lower than the second visibility; and if the presence of the other preceding vehicle is not detected, the light color change control of the lights is performed when the visibility falls below a fourth visibility where visibility is lower than the third visibility.

8. A vehicle lighting control device as described in claim 4, characterized in that when executing the light switching control, the yellow light and the white light are alternately turned on a predetermined number of times for a predetermined period of time, and then the yellow light or the white light is continued.

9. A vehicle light control method that performs light control including at least on / off control of lights mounted on the vehicle and light color switching control that switches the lighting color of the lights based on surrounding environment information acquired by a surrounding environment recognition device, characterized in that when visibility measured based on the surrounding environment information falls below a first visibility, the lights are turned on, and when visibility falls below a second visibility that is lower than the first visibility, the light color switching control is performed, and the start timing of the light color switching control is changed depending on whether or not there is another vehicle ahead, or the relative situation between the vehicle and the other vehicle ahead.

10. A recording medium having recorded thereon a light control program that causes a computer to execute the following processes: measuring visibility based on ambient environment information, and controlling the lights to turn on when the measured visibility falls below a first visibility; and when the visibility falls below a second visibility level at which visibility is lower than the first visibility, changing the start timing of the light color change control depending on whether or not there is another vehicle ahead, or the relative situation between the vehicle and the other vehicle ahead.

Images