WO2026028410A1 - Vehicle light control device, vehicle light control method, and recording medium with light control program recorded thereon - Google Patents

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

This invention relates to a vehicle light control device that controls the lights installed in vehicles such as automobiles, a vehicle light control method, and a recording medium on which a light control program is recorded.

Traditionally, vehicles such as automobiles are equipped with various types of lighting. These various types of lighting are controlled appropriately by a lighting control device in response to, for example, changes in the vehicle's surrounding environment.

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

Generally, when fog lamps are illuminated yellow, they have the advantage of being more visible to the outside (other vehicles, etc.) in bad weather conditions such as fog, rain, snow, and blizzards, while also making it easier to check the road conditions in the immediate vicinity of the vehicle. Therefore, it has been found that in bad weather, it is more desirable to set fog lamps to yellow rather than white.

On the other hand, white fog lamps have the advantage of being able to provide a high amount of light. For this reason, it is considered desirable to set the fog lamp color to white in conditions where relatively good long-distance visibility can be maintained, even in bad weather.

In this way, fog lights, when turned on in bad weather, for example, not only ensure visibility but also alert nearby vehicles, such as preceding, following, and oncoming vehicles, to the presence of the vehicle.

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

For example, a vehicle lighting control device disclosed in JP 2019-125372 A controls the on/off switching of fog lights depending on the surrounding environment (such as weather conditions). Therefore, by controlling the fog lights to be off on sunny days, it is possible to reduce the negative impact of fog lights on other vehicles.

Furthermore, vehicle lighting control devices disclosed in Japanese Patent Application Laid-Open Nos. 5-278519 and 2008-213618, among others, control the light intensity of rear fog lamps according to weather conditions (such as light transmittance) and the distance between the vehicle and the following vehicle.

For example, in bad weather when the distance to the following vehicle is short, the system will control the light intensity of the rear fog lamps to dim them or even prohibit them from being turned on, thereby minimizing the impact of the rear fog lamps on following vehicles.

Meanwhile, in recent years, various lamps installed in vehicles, such as those using light-emitting diodes (LEDs) as light source elements, have been put into practical use and are beginning to become widespread. Lamps that use this type of LED have the advantage of being able to switch and control the lighting color.

In response to this, for example, a vehicle lighting control device disclosed in JP 2021-114463 A performs lighting control such as switching the headlight color from white to yellow depending on weather conditions, etc., to turn the headlights on as fog lights.

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

However, when controlling lights during bad weather, for example, there is a need for more precise, better, and appropriate light control by taking into account even more detailed conditions.

The present invention aims to provide a vehicle light control device, a vehicle light control method, and a recording medium on which a light control program is recorded that can contribute to improving safety when driving a vehicle in bad weather.

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

One aspect of the present invention is a vehicle lighting control method that performs lighting control including at least on/off control of vehicle-mounted lighting and light color change control to change the lighting color of the lighting, based on surrounding environment information acquired by a surrounding environment recognition device. When visibility measured based on the surrounding environment information falls below a first visibility, the lighting is turned on, and when visibility falls below a second visibility that is lower than the first visibility, the lighting color change control is performed. The start timing of the lighting color change control is changed depending on whether or not there is another vehicle ahead, or the relative conditions between the vehicle and the other vehicle ahead.

A recording medium having recorded thereon a light control program according to one embodiment of the present invention causes a computer to execute the following processes: measuring visibility based on ambient environmental information, and turning on lights 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 level, changing the start timing of the light color change control depending on whether or not there is another vehicle ahead, or the relative conditions between the vehicle and the other vehicle ahead.

The present invention provides a vehicle light control device, a vehicle light control method, and a recording medium on which a light control program is recorded that can contribute to improving safety when driving a vehicle in bad weather.

FIG. 1 is a block diagram showing a schematic configuration of a vehicle control device including a vehicle lighting control device according to an embodiment of the present invention. 1 is a flowchart showing a part of the operation of a vehicle control device including a vehicle lighting control device according to an embodiment of the present invention. Subroutine of a first modified example of the operation of a vehicle control device including a vehicle light control device according to an embodiment of the present invention FIG. 10 is a flowchart showing a second modified example of the operation of a vehicle control device including a vehicle lighting control device according to an embodiment of the present invention.

The present invention will be described below using illustrated embodiments. The drawings used in the following description are schematic, and the dimensional relationships and scales of each component 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 forms in terms of the number of components shown in each drawing, the shape of each component, the size ratio of each component, or the relative positional relationships of each component.

First, the general configuration of a vehicle control device including a vehicle light control device according to one embodiment of the present invention will be briefly explained below using Figure 1. Figure 1 is a block diagram showing the general configuration of a vehicle control device including a vehicle light control device according to one embodiment of the present invention.

In order to avoid cluttering the drawing, Figure 1 shows only the components directly related to the present invention, and other components are omitted. In the following explanation, only the main components directly related to the present invention will be described in detail.

The configuration of the vehicle control device, including the vehicle lighting control device of this embodiment, is basically similar to that of conventional vehicle control devices of the same type.

The vehicle control device 1 is composed of a camera unit 10, a control unit 20, various sensors (described in detail below; 14, 15), and various control units (described in detail below; 21, 22).

The camera unit 10 is an in-vehicle camera device fixed to the upper center portion of the front interior of the vehicle (hereinafter referred to as the host vehicle; not shown) that is equipped with the vehicle control device 1. This camera unit 10 is composed of 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.

The stereo camera 11 is formed by 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 on either side of the center of the vehicle's width direction within the vehicle's cabin, facing forward (in the direction of travel) of the vehicle. The main camera 11a and the sub-camera 11b are each 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.

With this configuration, the stereo camera 11 uses the main camera 11a and sub-camera 11b to acquire two image data from two different viewpoints of the surrounding environment in a predetermined range in front of the vehicle at a predetermined imaging cycle that is synchronized with each other. Stereo image data is then generated based on the two image data acquired in this way. 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.

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

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 (host vehicle road) and the width between the left and right dividing lines (lane width), based on distance image information and other information input from the IPU 12. Various well-known methods are used to calculate this road curvature and lane width.

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 nearby vehicles, as well as the condition of the road surface (hereinafter referred to as road surface conditions, etc.).

Here, when recognizing a three-dimensional object in the image recognition unit 13, 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, and the relative distance between three-dimensional objects (for example, the lateral distance between a curb on the side of the road and a nearby dividing line, etc.). Furthermore, road surface conditions, such as whether the road surface is wet due to rain or melting snow, rainfall, snow accumulation, packed snow, or frozen road conditions, are recognized.

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

The control unit 20 is a structural unit or circuit unit that performs overall control of the vehicle control device 1. Various control units, such as a lighting control unit 21 and an operation input control unit 22, are connected to this control unit 20 via in-vehicle communication lines such as a CAN (Controller Area Network).

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

The light control unit 21 is a circuit unit that performs various controls on the various lights 31 installed on the vehicle, and is a light control device. For this reason, the various lights 31 are connected to the light control unit 21.

The various types of lighting 31 include, for example, floodlights, signal lights, and indicator lights. Of these, floodlights include, for example, headlights, front and rear fog lights, side lights, license plate lights, reversing lights, and interior lights. Signal lights include, for example, turn signals (blinkers or turn lamps), brake lights, tail lights, parking lights, side lights, and automatic driving indicator lights. Finally, indicator lights include indicator lighting for instruments, switches, air conditioning, audio equipment, and the like.

For example, the light control unit 21 controls various lighting functions, such as switching fog lamps and other lights on or off (on or off) depending on the vehicle's surrounding environment (weather, surrounding conditions of other vehicles, etc.), changing the timing of lighting, and switching the lighting color, as well as turning automatic driving marker lights on and off.

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

For this reason, light-emitting diodes (LEDs), for example, are used for the front fog lamps included in the lighting equipment 31. These front fog lamps can be controlled by the light control unit 21 to switch their illumination color between white and yellow.

The operation input control unit 22 is a component or circuit unit that receives instruction signals from a variety of operation input members 32 arranged inside the vehicle and transmits them to the control unit 20. In response, the control unit 20 outputs the necessary control instructions to the component unit corresponding to the received instruction signal. To this end, the operation input control unit 22 is connected to a variety of operation input members 32 arranged inside the vehicle.

The operation input members 32 include, for example, multiple switches for issuing commands to execute various driving assistance controls, and mode selector switches for switching driving modes (manual driving mode, autonomous driving mode, etc.). Other examples of the operation input members 32 include a steering touch sensor that detects the driver's steering state, a driver monitoring system (DMS) that detects the driver's facial recognition and line of sight, an in-vehicle monitor system consisting of an in-vehicle camera that recognizes the riding status of passengers including the driver, a touch panel display input device, various meters, etc.

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

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

The onboard radar device 14 is composed of multiple sensors, such as multiple millimeter-wave radars. The multiple millimeter-wave radars receive and analyze the radio waves they emit that are reflected from objects, primarily detecting three-dimensional objects such as pedestrians and vehicles traveling alongside, as well as structures (e.g., curbs, guardrails, building walls, plantings, and other three-dimensional objects) located on the edge of the road (e.g., the edge of the shoulder). 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 its representative point (relative position and distance to the vehicle), and its relative speed.

The multiple sensors (such as multiple millimeter-wave radars) included in the onboard radar device 14 are arranged, for example, on the left and right sides of the front bumper (referred to as front left and right side sensors) and 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 that exist 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 that exist in areas diagonally forward and to the left and right of the vehicle, which are difficult to recognize using the front left and right side sensors.

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

The locator unit 15 is composed of a GNSS sensor 15a and a high-precision road map database (road map DB) 15b.

The GNSS sensor 15a receives positioning signals transmitted from multiple positioning satellites to determine the vehicle's position (latitude, longitude, altitude, etc.).

Road map DB15b is a large-capacity storage medium such as an HDD (Hard Disk Drive) or SSD (Solid State Drive), and stores highly accurate road map information (dynamic maps). This road map DB15b holds 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.

The locator unit 15 can also communicate with an external system (not shown) to obtain real-time information about the surrounding environment at the vehicle's position measured by the GNSS sensor 15a (such as traffic congestion information and weather information). In this case, the weather information includes, for example, information about the occurrence of snowfall in the area including the vehicle's position, as well as information about rainfall, snowfall, snow accumulation, temperature and humidity.

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

The control unit 20 controls the vehicle's driving 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 onboard radar device 14, the locator unit 15, etc.

In addition, all or part of the image recognition unit 13, control unit 20, locator unit 15, light control unit 21, operation input control unit 22, etc. are configured using processors including hardware.

Here, the processor is composed of well-known components, such as a central processing unit (CPU), random access memory (RAM), read-only memory (ROM), non-volatile memory, non-volatile storage, and non-transitory computer readable medium, as well as peripheral devices.

The software programs executed by the CPU and fixed data such as data tables are pre-stored in ROM, non-volatile memory, non-volatile storage devices, etc. The CPU then reads the software programs stored in ROM, etc., expands them into RAM, and executes them. The software programs then refer to various data, etc. as appropriate, thereby realizing the functions of the above-mentioned components and units (13, 14, 15, 21, 22), etc.

Furthermore, the processor may be configured using semiconductor chips such as FPGAs (Field Programmable Gate Arrays). Furthermore, the above-mentioned components and units (13, 14, 15, 21, 22), etc. may be configured using electronic circuits.

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 portable disk media such as flexible disks, CD-ROMs, DVD-ROMs, or non-transitory computer-readable media such as card-type memory, HDD (Hard Disk Drive) devices, or SSD (Solid State Drive) devices.

The operation of the vehicle control device 1 including the vehicle light control device of this embodiment configured as described above will be explained below using Figure 2. Figure 2 is a flowchart showing part of the operation of the vehicle control device including the vehicle light control device of this embodiment.

In more detail, Figure 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 that includes the light control device (light control unit 21) of this embodiment is traveling on a road or the like.

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

At this time, in step S11 of Figure 2, the control unit 20 continues driving while recognizing the environment surrounding 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 processing performed here is a well-known process that is commonly performed in conventional vehicle control devices.

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 conditions such as fog, rain, or snow 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, such as fog lamps, turned on.

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.

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

If it is confirmed in 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 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 step S14. In step S12, it is confirmed whether the visibility has fallen below a predetermined threshold (first visibility).

Next, in step S14, the control unit 20 checks via the light control unit 21 whether the fog lamps, which are part of the lamps 31, are on. 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.

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

On the other hand, 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.

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

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

In step S18, the control unit 20 executes a light control process to change the illumination color of the fog lamps, among the lights 31, from yellow to white via the light control unit 21. Then, the process proceeds to step S19.

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 (e.g., 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 fallen below a predetermined threshold (second visibility).

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 onboard 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.

In step S21, the control unit 20 checks the relative situation between the subject vehicle and the preceding vehicle based on information acquired by the camera unit 10 or the onboard radar device 14. The relative situation between the subject vehicle and the preceding vehicle includes, for example, the distance from the subject vehicle to the preceding vehicle, the approach speed of the subject vehicle to the preceding vehicle, or the width (length) or rear size (area) of the preceding vehicle.

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

Therefore, in the processing of step S21, the control unit 20 checks whether the distance from the host vehicle to the preceding vehicle is shorter than a predetermined distance, whether the host vehicle's approach speed to 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.

Note that the thresholds for the predetermined distance from the vehicle to the preceding vehicle, the approach speed of the vehicle to the preceding vehicle, and the width or rear size of the preceding vehicle are set to predetermined values as appropriate.

Here, in any of the following cases, when the distance from the subject vehicle to the preceding vehicle is shorter than a predetermined distance, when the subject vehicle is approaching the preceding vehicle at a high speed, or when the preceding vehicle has a large width or rear size, it is desirable to make the preceding vehicle aware of the presence of the subject vehicle as a following vehicle as early as possible.

For example, it is known that the shorter the distance from the vehicle to the preceding vehicle, or the faster the vehicle approaches the preceding vehicle, the greater the risk of collision between the vehicle and the preceding vehicle. Therefore, preceding vehicles want to be aware of the presence of the vehicle behind them as soon as possible.

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 rain droplets or snow smoke kicked up by the wheels of the preceding vehicle will be considerable. This tends to reduce rear visibility for the preceding vehicle and forward visibility for the following vehicle.

In this embodiment, the light control unit 21 therefore controls the fog lamps to change from white to yellow at an earlier timing 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. This allows the preceding vehicle to quickly become aware of the presence of the vehicle, which is the following vehicle. In other words, in bad weather conditions, the lower the visibility, the more yellow it is desirable to change the fog lamps to yellow.

Returning to Figure 2, if any of the above three situations is met in step S21, the process proceeds to step S23. If none of the above three situations is met, the process proceeds to step S24.

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

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 the 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. In other words, in step S21, it is determined whether the visibility has fallen below a predetermined threshold (third visibility). If the visibility has fallen below the predetermined threshold (third visibility), the process of step S23 (light color switching control process [white to yellow]) is executed.

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

In this embodiment, the predetermined visibility thresholds are exemplified as first visibility, second visibility, third visibility, and fourth visibility. In this case, each predetermined threshold is set to a value that decreases visibility in the order of first visibility, second visibility, third visibility, and fourth visibility (first visibility > second visibility > third visibility > fourth visibility).

Specifically, the first visibility is, for example, a visibility of less than 200 meters. The second visibility is, for example, a visibility of less than 150 meters. The third visibility is, for example, a visibility of less than 100 meters. The fourth visibility is, for example, a visibility of less than 50 meters.

The above numerical settings are based on the fact that the standard visibility for dense fog, etc. is generally defined as 200 meters, but these setting values are not limited to the example values and can be set as appropriate.

As described above, according to the embodiment, when a vehicle is driven in 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.

In this case, if the presence of a preceding vehicle is confirmed, the timing for starting light color change control is changed depending on the condition of the preceding vehicle (for example, the distance from the vehicle to the preceding vehicle, the approaching speed of the vehicle to the preceding vehicle, or the width of the preceding vehicle).

In other words, if the distance from the vehicle to the preceding vehicle is short, if the vehicle is approaching the preceding vehicle at a high speed, or if the preceding vehicle is large in width, the light color change process is performed early.

By controlling the lights in this way, it is possible to contribute to improving the visibility of the surroundings of the vehicle. At the same time, it is possible to make the presence of the vehicle more easily recognized by those around it (especially other vehicles ahead, etc.). This therefore contributes to ensuring the driving safety of the vehicle and other vehicles in the vicinity.

Incidentally, the process of step S23 in Figure 2 (light color switching control process from white to yellow) simply switches the light color. However, when executing the light color switching control process, a processing step such as that shown in Figure 3 (light color alternating lighting process) may be added.

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 that includes a light color alternating lighting processing step that is executed during the processing of step S23 in Figure 2 (light color switching control processing [switching from yellow to white]).

In this first variant, when the light color change control process is executed to change from white to yellow, a specified light color change control is performed, providing a function to more clearly notify nearby vehicles that the light color has changed.

That is, in step S31 of FIG. 3, the light control unit 21 checks whether a switch instruction signal for switching the lighting color of the currently lit fog lamps 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).

In step S32, the control unit 20 starts executing a light control process to change the illumination color of the fog lamps, among the lights 31, from white to yellow via the light control unit 21.

In the processing of step S32, first, the light control unit 21 switches the lighting color of the currently lit fog lamps from white to yellow. Then, after switching the lighting color, the yellow lighting continues for a predetermined time (e.g., several seconds). After the predetermined time (e.g., several seconds) has elapsed, the lighting color is switched from yellow to white, and similarly the white lighting continues for a predetermined time (e.g., several seconds). In this way, the yellow lighting and white lighting are alternated for a predetermined time (e.g., several seconds each) a predetermined number of times (e.g., five times each). Then, the processing proceeds to step S33.

Next, in step S33, the control unit 20 causes the fog lamps, among the lamps 31, to continue to illuminate yellow via the light control unit 21. Then, the series of processes ends (return).

In this way, when visibility is reduced due to bad weather, for example, by performing the process of step S23 in Figure 2 (light color switching process), and also adding the process of alternating light colors (processing steps of steps S32 and S33 in Figure 3), it is possible to contribute to making the presence of the host vehicle more clearly visible to the surrounding area (especially other vehicles ahead, etc.). At the same time, it is possible to obtain effects substantially similar to those of the first embodiment described above. This can therefore further contribute to ensuring the driving safety of the host vehicle and other vehicles in the vicinity.

Furthermore, in this process, the illumination color is alternately switched between yellow and white, allowing continuous illumination of the area ahead of the vehicle. This therefore ensures continuous forward visibility for the vehicle. At the same time, other vehicles ahead can continuously recognize the vehicle.

Furthermore, the alternating light color lighting process (the processing step shown as step S32 in Figure 3) is not limited to the above-mentioned form. For example, the alternating light color lighting process can be applied even in the following example situations.

Figure 4 shows a second modified example of the operation of a vehicle control device including the vehicle lighting control device of this embodiment, and shows the alternating light color lighting processing step added after the processing of step S23 in Figure 2.

In this second variant, when the vehicle is traveling with its fog lights illuminated in yellow and it is detected that the vehicle is approaching a preceding vehicle, the system executes alternating light color illumination processing.

First, after processing 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 onboard 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. The process then returns to step S11 in FIG. 2.

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 similarly the yellow illumination continues for a predetermined time (e.g., several seconds). In this way, the yellow illumination and white illumination are alternated 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.

Next, in step S43, the control unit 20 causes the fog lamps, among the lamps 31, to continue to illuminate yellow via the light control unit 21. Then, the process returns to step S11.

Note that the processes in steps S42 and S43 in Figure 4 are the same as those in steps S32 and S33 in Figure 3 described above.

In this way, for example, in situations 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 yellow after the processing of step S23 in FIG. 2 (light color switching processing), the additional processing 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 known to those around it (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 other surrounding vehicles.

The present invention is not limited to the above-described embodiments, and various modifications and applications can be made without departing from the spirit of the invention. Furthermore, the above-described embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining the multiple disclosed constituent elements. For example, if the problem that the invention aims to solve 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 combined as appropriate. This invention is not restricted by specific embodiments other than as limited by the appended claims.

Claims (10)

A vehicle lighting control device that executes lighting control including at least on/off control of lighting devices mounted on a vehicle and lighting color switching control that switches the lighting colors of the lighting devices based on surrounding environment information acquired by a surrounding environment recognition device,
one or more processors including hardware;
The processor:
When the visibility measured based on the surrounding environment information becomes shorter than a first visibility, the lamps are turned on;
A vehicle lighting control device characterized in that, when performing lighting color change control of the lights when visibility falls below a second visibility range that is lower than the first visibility range, the start timing of the lighting color change 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. the surrounding environment recognition device is a camera unit,
the camera unit includes a stereo camera device;
2. The vehicle lighting control device according to claim 1, wherein the surrounding environment information acquired by the surrounding environment recognition device is distance image information. The vehicle lighting control device described in claim 1, characterized in that the lighting devices mounted on the vehicle include at least fog lamps. The vehicle lighting control device described in claim 1, characterized in that the lighting color switching control performs lighting control to switch the lighting color of the lighting elements between white lighting and yellow lighting. The light color switching control is
When the visibility becomes shorter than the first visibility range, the lights are turned on in white light;
2. The vehicle light control device according to claim 1, wherein the lamps are turned on in yellow when the visibility is less than the second visibility range. The vehicle light control device described in claim 1, characterized in that the relative situation between the host vehicle and the other preceding vehicle is at least the distance between the host vehicle and the other preceding vehicle, the approach speed of the host vehicle to the other preceding vehicle, or the width size or rear area of the other preceding vehicle. When the visibility becomes less than a second visibility that is lower than the first visibility and the light color change control of the lamps is performed, if the presence of the preceding vehicle is detected,
When the distance between the subject vehicle and the preceding vehicle is short, when the subject vehicle approaches the preceding vehicle at a high speed, or when the width or rear area of the preceding vehicle is large, the lighting color switching control of the lamps is immediately performed;
When the distance between the host vehicle and the preceding vehicle is short, when the approaching speed of the host vehicle to the preceding vehicle is high, or when the width size or rear area of the preceding vehicle is large, the lighting color switching control of the lamps is performed when the visibility becomes less than a third visibility range that is lower than the second visibility range,
7. A vehicle lighting control device according to claim 6, wherein when the presence of the preceding vehicle is not detected, the light color switching control of the lamps is performed when the visibility falls below a fourth visibility range that is lower than the third visibility range. When the light switching control is executed,
5. The vehicle light control device according to claim 4, wherein 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. 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,
When the visibility measured based on the surrounding environment information becomes shorter than a first visibility, the lamps are turned on;
A vehicle lighting control method characterized in that, when performing lighting color change control of the lights when the visibility falls below a second visibility that is lower than the first visibility, the start timing of the lighting color change 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. a process of measuring visibility based on surrounding environment information, and turning on lights when the measured visibility is less than a first visibility;
a process for changing a start timing of the light color change control in accordance with the presence or absence of a preceding vehicle or the relative situation between the subject vehicle and the preceding vehicle when the visibility becomes less than a second visibility that is lower than the first visibility;
A recording medium on which a lighting control program is recorded that causes a computer to execute the above.