Surrounding environment determination device

Abstract

The present invention provides a surrounding environment determination device that can determine with high accuracy and speed whether the surrounding environment of a vehicle is unfavorable, even when there are vehicles overtaking or passing by. [Solution] The surrounding environment determination device 20 includes a camera 7 and a surrounding environment detection unit 11 for detecting the environmental conditions around the vehicle 2, a camera 7, a target detection unit 12 and a vehicle detection unit 13 for detecting the presence or absence of other vehicles overtaking the vehicle 2 or passing the vehicle 2, and a bad environment determination unit 14 for determining whether the surrounding environment of the vehicle 2 is a bad environment based on the environmental conditions around the vehicle 2 and the presence or absence of other vehicles. The bad environment determination unit 14 determines whether the surrounding environment of the vehicle 2 is a bad environment by comparing the detection score of the environmental conditions around the vehicle 2 with a bad environment threshold corresponding to the environmental conditions around the vehicle 2, and the bad environment threshold differs depending on the presence or absence of other vehicles.

Description

Technical Field

[0001] The present invention relates to a peripheral environment determination device.

Background Art

[0002] As a conventional peripheral environment determination device, for example, the technique described in Patent Document 1 is known. The peripheral environment determination device described in Patent Document 1 includes an imaging device that images a predetermined range around a vehicle, and by analyzing the image captured by the imaging device, obtains recognition information of target ground objects including landmarks, and based on the recognition information of the target ground objects, determines whether the peripheral environment of the vehicle is a bad environment for object recognition using the image. When no target ground object is recognized within a predetermined distance from the imaging device, it is determined that the peripheral environment of the vehicle is a bad environment.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the above prior art, in order to determine whether the peripheral environment of the vehicle is a bad environment based on the detection state of landmarks (stationary objects), the responsiveness until it is determined to be a bad environment may be slow depending on the situation. Specifically, when the front visibility of the host vehicle is deteriorated by rain splashes or snow lifted by another vehicle (overtaking vehicle) trying to overtake the host vehicle or another vehicle (oncoming vehicle) passing by the host vehicle, it will be determined to be a bad environment due to the decreased visibility of the landmark. Also, at night or the like, since the detection performance of landmarks itself tends to decrease, the responsiveness until it is determined to be a bad environment may be further delayed, or it may become difficult to determine whether it is a bad environment.

[0005] The object of the present invention is to provide an ambient environment determination device that can determine with high accuracy and speed whether the ambient environment around a vehicle is unfavorable, even when there are vehicles overtaking or passing by. [Means for solving the problem]

[0006] (1) One aspect of the present invention is an ambient environment determination device for determining the environment around a vehicle when controlling the high beams of the vehicle, comprising: an ambient environment detection unit for detecting the ambient environment around the vehicle; an other vehicle detection unit for detecting the presence or absence of other vehicles overtaking the vehicle or passing the vehicle; and a bad environment determination unit for determining whether the ambient environment around the vehicle is a bad environment based on the ambient environment detected by the ambient environment detection unit and the presence or absence of other vehicles detected by the other vehicle detection unit, wherein the bad environment determination unit determines whether the ambient environment around the vehicle is a bad environment by comparing the detection score of the ambient environment around the vehicle with a bad environment threshold corresponding to the ambient environment around the vehicle, and the bad environment threshold differs depending on the presence or absence of other vehicles.

[0007] (2) In (1) above, the surrounding conditions detection unit detects whether it is raining or snowing as an environmental condition, and the adverse environment threshold may differ depending on the presence or absence of other vehicles and whether it is raining or snowing.

[0008] (3) In (2) above, the adverse environment threshold when other vehicles are present may be smaller than the adverse environment threshold when other vehicles are not present, and the adverse environment threshold for snowy conditions may be smaller than the adverse environment threshold for rainy conditions.

[0009] (4) In any of (1) to (3) above, the other vehicle detection unit may detect whether another vehicle is within a specified distance from the vehicle, and the adverse environment determination unit may change the adverse environment threshold according to the surrounding environmental conditions of the vehicle when the other vehicle detection unit has detected that another vehicle is within a specified distance from the vehicle.

[0010] (5) In any of (1) to (4) above, the surrounding conditions detection unit may use a camera that takes images of the area around the vehicle to detect the environmental conditions around the vehicle, and the other vehicle detection unit may use a camera to detect the presence or absence of other vehicles. [Effects of the Invention]

[0011] According to the present invention, even when there are vehicles overtaking or passing by, it is possible to determine with high accuracy and speed whether or not the surrounding environment of one's own vehicle is in a bad environment. [Brief explanation of the drawing]

[0012] [Figure 1] This is a schematic diagram showing a vehicle headlight control device equipped with a surrounding environment determination device according to one embodiment of the present invention. [Figure 2] Figure 1 is a flowchart showing the procedure for the judgment and control processing performed by the ECU. [Figure 3] This figure shows an example of camera image data when an overtaking vehicle passes another vehicle. [Figure 4] This graph shows the snow conditions score when an overtaking vehicle overtakes your vehicle, along with the adverse conditions threshold. [Modes for carrying out the invention]

[0013] Embodiments of the present invention will be described in detail below with reference to the drawings.

[0014] Figure 1 is a schematic diagram showing a vehicle headlight control device equipped with a surrounding environment determination device according to one embodiment of the present invention. In Figure 1, the vehicle headlight control device 1 is mounted on the vehicle 2 which has an automatic high beam (ADB) function that automatically switches between high beam and low beam.

[0015] The vehicle headlight control device 1 is a device that controls two headlights 3 (headlamps) respectively arranged on the left and right sides at the front of the host vehicle 2. The vehicle headlight control device 1 detects the road conditions and surrounding environment in front of the host vehicle 2, and controls the headlights 3 to switch from high beam to low beam at an appropriate timing. The headlight 3 has a low beam light source 4 and a high beam light source 5.

[0016] The vehicle headlight control device 1 includes a camera 7, a vehicle speed sensor 8, an ADB switch 9, and an ECU (Electronic Control Unit) 10.

[0017] The camera 7 is an imaging unit that images the periphery of the host vehicle 2 and acquires image data of the periphery of the host vehicle 2. The periphery of the host vehicle 2 is the front, rear, and sides of the host vehicle 2. As the camera 7, for example, a monocular camera or a stereo camera is used.

[0018] The vehicle speed sensor 8 is a sensor that detects the traveling speed (vehicle speed) of the host vehicle 2. The ADB switch 9 is a manual changeover switch for the driver of the host vehicle 2 to activate (ON) or deactivate (OFF) the auto high beam function.

[0019] The ECU 10 is composed of a CPU, a RAM, a ROM, an input / output interface, etc. The ECU 10, for example, loads a program recorded in the ROM into the RAM, and executes the program loaded into the RAM with the CPU.

[0020] The ECU 10 has a surrounding environment detection unit 11, a target detection unit 12, an other vehicle determination unit 13, a bad environment determination unit 14, and a lamp control unit 15.

[0021] The camera 7, the surrounding environment detection unit 11, the target detection unit 12, the other vehicle determination unit 13, and the bad environment determination unit 14 constitute the surrounding environment determination device 20 of the present embodiment. The surrounding environment determination device 20 is a device that determines the environment around the host vehicle 2 when controlling the high beam of the host vehicle 2.

[0022] The surrounding environment detection unit 11 detects the environmental conditions around the host vehicle 2 based on the image data acquired by the camera 7. The surrounding environment detection unit 11 constitutes a surrounding situation detection unit that detects the environmental conditions around the host vehicle 2 in cooperation with the camera 7. That is, the surrounding situation detection unit uses the camera 7 to detect the environmental conditions around the host vehicle 2. The surrounding environment detection unit 11 detects the state of rain or snow around the host vehicle 2 as the environmental conditions around the host vehicle 2. Note that sleet, hail, and snow grains are included in rain.

[0023] The target detection unit 12 detects the targets existing around the host vehicle 2 based on the image data acquired by the camera 7. The targets include other vehicles, motorcycles, people, obstacles, and the like.

[0024] The other vehicle determination unit 13 determines whether there is an other vehicle (overtaking vehicle) that overtakes the host vehicle 2 or an other vehicle (oncoming vehicle) that passes by the host vehicle 2 based on the detection result of the target detection unit 12. The other vehicle determination unit 13 determines whether the overtaking vehicle or the oncoming vehicle exists within a specified distance from the host vehicle 2.

[0025] The target detection unit 12 and the other vehicle determination unit 13 constitute an other vehicle detection unit that detects the presence or absence of an other vehicle that overtakes the host vehicle 2 or an other vehicle that passes by the host vehicle in cooperation with the camera 7.

[0026] The bad environment determination unit 14 determines whether the surrounding environment of the host vehicle 2 is a bad environment based on the environmental conditions around the host vehicle 2 detected by the surrounding environment detection unit 11 and the presence or absence of the overtaking vehicle or the oncoming vehicle determined by the other vehicle determination unit 13.

[0027] The bad environment determination unit 14 determines whether the surrounding environment of the host vehicle 2 is a bad environment by comparing the detection score of the environmental conditions around the host vehicle 2 with a bad environment threshold value corresponding to the environmental conditions around the host vehicle 2.

[0028] The adverse environment threshold varies depending on the presence or absence of overtaking or passing vehicles and the condition of the road (rain or snow). The adverse environment threshold when overtaking or passing vehicles are present is lower than the adverse environment threshold when neither is present. The adverse environment threshold in snowy conditions is lower than the adverse environment threshold in rainy conditions. The adverse environment threshold will be explained in more detail later.

[0029] When the adverse environment determination unit 14 determines that an overtaking vehicle or a passing vehicle is within a specified distance from the vehicle 2, it changes the adverse environment threshold according to the environmental conditions around the vehicle 2.

[0030] When the auto high beam function is activated (ON) by the ADB switch 9, the lamp control unit 15 controls the low beam light source 4 and high beam light source 5 of the headlight 3 to switch between high beam and low beam based on the surrounding environment conditions of the vehicle 2 detected by the surrounding environment detection unit 11, the detection results of the target detection unit 12, the determination results of the other vehicle determination unit 13, and the vehicle speed of the vehicle 2 detected by the vehicle speed sensor 8. The lamp control unit 15 has a low beam control unit 16 that controls the low beam light source 4 and a high beam control unit 17 that controls the high beam light source 5.

[0031] The high beam control unit 17 controls the high beam light source 5 to activate the high beams when the following conditions are met: there are no oncoming or preceding vehicles in front of the vehicle 2; the surroundings of the vehicle 2 are unnecessarily dark due to the absence of streetlights or other light sources; and the vehicle 2 is traveling at a specified speed or higher. The high beam control unit 17 controls the high beam light source 5 to stop illuminating the high beams when any of the above three conditions are not met.

[0032] The low beam control unit 16 controls the low beam light source 4 to stop illuminating the low beam when the following conditions are met: there are no oncoming or preceding vehicles in front of the vehicle 2; the surroundings of the vehicle 2 are unnecessarily dark due to the absence of streetlights or other light sources; and the vehicle 2 is traveling at a specified speed or higher. The low beam control unit 16 controls the low beam light source 4 to activate the low beam when any of the above three conditions are not met.

[0033] Figure 2 is a flowchart showing the procedure for the judgment and control processing performed by the ECU 10. The process shown in Figure 2 involves determining the surrounding environment of the vehicle 2 and controlling the high beam light source 5 according to the determination result.

[0034] In Figure 2, the ECU 10 first detects the presence or absence of other vehicles based on the image data from camera 7 (procedure S101). The ECU 10 also detects whether it is raining or snowing based on the image data from camera 7 (procedure S102). Next, the ECU 10 determines whether the other vehicle detected in procedure S101 was an overtaking vehicle or a passing vehicle (procedure S103).

[0035] If the ECU10 determines that no overtaking or passing vehicles have been detected, it determines whether the snow condition score detected in step S102 is equal to or greater than the threshold Pa for adverse snow conditions without other vehicles (step S104).

[0036] The snow condition score is one of the detection scores for the environmental conditions around vehicle 2. The snow condition score is a numerical representation of the snow conditions in front of vehicle 2. The more snow there is in front of vehicle 2, the higher the snow condition score. The adverse environment threshold Pa for snow without other vehicles is the adverse environment threshold for snow when there are no overtaking or passing vehicles. The adverse environment threshold Pa for snow without other vehicles is, for example, 30.

[0037] When the ECU 10 determines that the snow condition score is above the adverse snow environment threshold Pa for vehicles without other vehicles, it determines that the surrounding environment of its own vehicle 2 is an adverse environment (procedure S105). Then, the ECU 10 controls the high beam light source 5 to turn off the high beams (procedure S106) and repeats the above procedure S101.

[0038] If the ECU10 determines in step S104 that the snow condition score is not equal to or greater than the adverse environment threshold Pa for snow without other vehicles, it then determines in step S102 whether the rain condition score detected is equal to or greater than the adverse environment threshold Pb for rain without other vehicles (step S107).

[0039] The rain condition score is another score for detecting the environmental conditions around vehicle 2. The rain condition score is a numerical representation of the rain conditions in front of vehicle 2. The more rain there is in front of vehicle 2, the higher the rain condition score. The adverse environment threshold Pb for rain without other vehicles is the adverse environment threshold for rain when there are no overtaking or passing vehicles. The adverse environment threshold Pb for rain without other vehicles is, for example, 40.

[0040] In snowy weather, visibility ahead of vehicle 2 is more likely to be poor compared to rainy weather. Therefore, to ensure that snowy scenes are more likely to be judged as adverse conditions than rainy scenes, the adverse environment threshold Pa for snow without other vehicles is smaller than the adverse environment threshold Pb for rain without other vehicles.

[0041] When ECU10 determines that the rain condition score is equal to or greater than the adverse environment threshold Pb for rain without other vehicles, it determines that the surrounding environment of its own vehicle 2 is an adverse environment (procedure S105). Then, ECU10 controls the high beam light source 5 to turn off the high beam (procedure S106) and repeats procedure S101 above.

[0042] When ECU10 determines that the rain condition score is not above the adverse environment threshold Pb for rain without other vehicles, it determines that the surrounding environment of its own vehicle 2 is not an adverse environment (procedure S108). Then, ECU10 controls the high beam light source 5 to turn on the high beam (procedure S109) and performs procedure S101 again.

[0043] If the ECU 10 determines in step S103 that an overtaking vehicle or a passing vehicle has been detected, it determines whether the overtaking vehicle or the passing vehicle is within a specified distance from its own vehicle 2 (step S110). The specified distance is, for example, 30m. If the ECU 10 determines that neither the overtaking vehicle nor the passing vehicle is within the specified distance from its own vehicle 2, it executes the steps from S104 onwards described above.

[0044] When the ECU 10 determines that an overtaking vehicle or a passing vehicle is within a specified distance from its own vehicle 2, it determines whether the overtaking vehicle or the passing vehicle is within one lane to the left or right of its own vehicle 2 (procedure S111). If the ECU 10 determines that the overtaking vehicle and the passing vehicle are not within one lane to the left or right of its own vehicle 2, it executes the above procedure S104 onwards.

[0045] When the ECU 10 determines that an overtaking or passing vehicle is within one lane to the left or right of its own vehicle 2, it determines whether the snow condition score detected in step S102 is equal to or greater than the adverse snow conditions threshold Qa for vehicles present (step S112). The adverse snow conditions threshold Qa for vehicles present is the adverse snow conditions threshold when an overtaking or passing vehicle is present. For example, the adverse snow conditions threshold Qa for vehicles present is 10.

[0046] When an overtaking or passing vehicle approaches vehicle 2, snow is kicked up by the overtaking or passing vehicle, which can easily cause poor visibility ahead of vehicle 2. Therefore, when an overtaking or passing vehicle is within one lane to the left or right of vehicle 2, the adverse environment threshold Qa for snow with other vehicles is smaller than the adverse environment threshold Pa for snow without other vehicles, making it more likely to be judged as an adverse environment.

[0047] When ECU10 determines that the snow condition score is equal to or greater than the adverse environment threshold Qa for snow with other vehicles present, it determines that the surrounding environment of its own vehicle 2 is an adverse environment (procedure S105). Then, ECU10 controls the high beam light source 5 to turn off the high beam (procedure S106) and repeats the above procedure S101.

[0048] If the ECU 10 determines in step S112 that the snow condition score is not equal to or greater than the adverse environment threshold Qa for snow with other vehicles, it then determines in step S102 whether the rain condition score detected is equal to or greater than the adverse environment threshold Qb for rain with other vehicles (step S113). The adverse environment threshold Qb for rain with other vehicles is the adverse environment threshold for rain when there are overtaking or passing vehicles. The adverse environment threshold Qb for rain with other vehicles is 20.

[0049] When an overtaking or passing vehicle approaches vehicle 2, rain spray is kicked up by the overtaking or passing vehicle, which can easily cause poor visibility ahead of vehicle 2. Therefore, when an overtaking or passing vehicle is within one lane to the left or right of vehicle 2, the adverse environment threshold Qb for rain with other vehicles is smaller than the adverse environment threshold Pb for rain without other vehicles, making it more likely to be judged as an adverse environment.

[0050] Furthermore, snow is lighter than rain. Therefore, the time that whipped snow remains airborne is longer than the time that whipped rain remains airborne. Consequently, the duration of poor visibility in front of vehicle 2 due to whipped snow is considered to be longer than the duration of poor visibility in front of vehicle 2 due to whipped rain. For this reason, the adverse environment threshold Qa for snow with other vehicles present is smaller than the adverse environment threshold Qb for rain with other vehicles present, so that snow scenes are more likely to be judged as adverse environments than rain scenes.

[0051] When ECU10 determines that the rain condition score is equal to or greater than the adverse environment threshold Qb for rain with other vehicles present, it determines that the surrounding environment of its own vehicle 2 is an adverse environment (procedure S105). Then, ECU10 controls the high beam light source 5 to turn off the high beam (procedure S106) and repeats procedure S101.

[0052] If the ECU 10 determines that the rain condition score is not equal to or greater than the adverse environment threshold Qb for rain with other vehicles present, it determines that the surrounding environment of its own vehicle 2 is not an adverse environment (procedure S108). Then, the ECU 10 controls the high beam light source 5 to turn on the high beam (procedure S109) and performs the above procedure S101 again.

[0053] Here, the surrounding environment detection unit 11 executes procedure S102. The target detection unit 12 executes procedure S101. The other vehicle determination unit 13 executes procedures S103, S110, and S111. The adverse environment determination unit 14 executes procedures S104, S105, S107, S108, S112, and S113. The high beam control unit 17 of the lamp control unit 15 executes procedures S106 and S109.

[0054] In the vehicle headlight control device 1 described above, when driving on a snowy road at night, if there are no oncoming or preceding vehicles in front of the vehicle 2, and the surroundings of the vehicle 2 are dark and the vehicle 2 is traveling at a specified speed or higher, the high beam of the headlight 3 is turned ON.

[0055] In such a situation, as shown in Figure 3(a), if there is an overtaking vehicle A in the lane to the right of the lane in which vehicle 2 is traveling, it is determined whether the surrounding environment of vehicle 2 is adverse by comparing the snow condition score with the adverse environment threshold Qa for snow with other vehicles. At this time, as shown in Figure 4(a), if the snow condition score is lower than the adverse environment threshold Qa for snow with other vehicles, it is determined that the surrounding environment of vehicle 2 is not adverse. Also, overtaking vehicle A is not yet traveling in front of vehicle 2. For this reason, the high beam of the headlight 3 remains ON.

[0056] Subsequently, as shown in Figure 3(b), vehicle 2 is overtaken by vehicle A. At this time, as shown in Figure 4(b), if the snow condition score does not change, it is determined that the environment around vehicle 2 is not adverse because the snow condition score is lower than the adverse environment threshold Qa for snow with other vehicles. However, vehicle A is traveling ahead of vehicle 2. Therefore, the high beam of the headlight 3 switches from the ON state to the OFF state.

[0057] Subsequently, as shown in Figure 3(c), when overtaking vehicle A passes vehicle 2, snow is kicked up from the road surface. As a result, as shown in Figure 4(c), the snow condition score increases, but since the snow condition score is lower than the adverse environment threshold Qa for snow with other vehicles, it is determined that the surrounding environment of vehicle 2 is not adverse. Also, since overtaking vehicle A is traveling in front of vehicle 2, the high beam of the headlight 3 remains OFF.

[0058] Subsequently, as shown in Figure 3(d), the visibility in front of vehicle 2 deteriorates due to the kicked-up snow. Then, as shown in Figure 4(c), the snow condition score increases further. When the snow condition score becomes higher than the adverse environment threshold Qa for snow with other vehicles, it is determined that the environment around vehicle 2 is adverse. For this reason, the high beam of the headlight 3 remains OFF, regardless of whether or not there is an overtaking vehicle A traveling in front of vehicle 2.

[0059] Subsequently, as shown in Figure 3(e), the kicked-up snow further worsens the forward visibility of vehicle 2, making it barely possible to see the streetlights and traffic lights in front of vehicle 2. Then, as shown in Figure 4(e), the snow condition score increases further. In this case as well, since the snow condition score is higher than the adverse environment threshold Qa for snow with other vehicles, the surrounding environment of vehicle 2 is determined to be adverse, and the high beam of the headlight 3 is kept OFF.

[0060] Incidentally, if there is an overtaking or passing vehicle, the recognition performance of camera 7 becomes unstable due to rain spray or snow being kicked up. Therefore, even when there is an oncoming or preceding vehicle in front of vehicle 2, there is a risk that the high beams will shine in front of vehicle 2. For this reason, it is necessary to determine whether the surrounding environment of vehicle 2 is adverse.

[0061] However, when determining whether the surrounding environment of vehicle 2 is a bad environment by comparing the snow condition score with the adverse snow environment threshold Pa for vehicles without other vehicles during snowy weather, the following problem occurs.

[0062] In other words, even if the visibility in front of vehicle 2 is impaired by the kicked-up snow (see Figure 3(d)), the snow condition score is lower than the adverse environment threshold Pa for snow without other vehicles, so the surrounding environment of vehicle 2 is determined not to be adverse (see Figure 4(d)). Also, because the visibility in front of vehicle 2 is impaired by the kicked-up snow, camera 7 fails to detect overtaking vehicle A, even though overtaking vehicle A is driving in front of vehicle 2. As a result, the high beam of the headlight 3 switches from the OFF state to the ON state.

[0063] Subsequently, when the streetlights and traffic lights in front of vehicle 2 become barely visible (see Figure 3(e)), the snow condition score becomes higher than the adverse snow environment threshold Pa for vehicles without other vehicles, and the surrounding environment of vehicle 2 is determined to be adverse (see Figure 4(e)). At this point, the high beam of the headlight 3 is switched from the ON state to the OFF state.

[0064] On the other hand, in this embodiment, when an overtaking vehicle A is present, the snow condition score is compared with a threshold Qa for a bad snow environment with other vehicles, which is smaller than the threshold Pa for a bad snow environment without other vehicles, to determine whether the surrounding environment of the vehicle 2 is a bad environment. Therefore, if the visibility in front of the vehicle 2 deteriorates due to snow kicked up when the overtaking vehicle A passes the vehicle 2, it becomes easier to determine that the surrounding environment of the vehicle 2 is a bad environment. Consequently, even if the camera 7 fails to detect the overtaking vehicle A due to poor visibility in front of the vehicle 2, the high beam of the headlight 3 will turn OFF.

[0065] As described above, according to this embodiment, the environmental conditions around the vehicle 2 are detected, as well as the presence or absence of other vehicles overtaking the vehicle 2 (overtaking vehicles) or other vehicles passing the vehicle 2 (passing vehicles). Then, by comparing the detection score of the environmental conditions around the vehicle 2 with a bad environment threshold corresponding to the environmental conditions around the vehicle 2, it is determined whether the environment around the vehicle 2 is a bad environment. In this way, by comparing the detection score of the environmental conditions with a bad environment threshold corresponding to the environmental conditions, it is quickly determined whether the environment around the vehicle 2 is a bad environment. Here, the bad environment threshold differs depending on the presence or absence of overtaking vehicles or passing vehicles. Therefore, since the detection score of the environmental conditions is compared with a bad environment threshold appropriate for the presence or absence of overtaking vehicles or passing vehicles, it is possible to determine with high accuracy whether the environment around the vehicle 2 is a bad environment. As a result, even when overtaking vehicles or passing vehicles are present, it is possible to determine with high accuracy and quickly whether the environment around the vehicle 2 is a bad environment. As a result, it is possible to suppress the illumination of the high beams in front of vehicle 2 even when another vehicle is driving in front of vehicle 2.

[0066] Furthermore, in this embodiment, the surrounding environmental conditions of the vehicle 2 include detection of rain or snow, and the adverse environment threshold differs depending on the presence or absence of overtaking or passing vehicles and the rain or snow conditions. Therefore, in rainy or snowy weather, if there are overtaking or passing vehicles, it is foreseen that the visibility in front of the vehicle 2 will be reduced due to the kick-up of rain or snow, and then it is determined whether the surrounding environment of the vehicle 2 is adverse. Consequently, even in rainy or snowy weather, it is possible to determine with high accuracy whether the surrounding environment of the vehicle 2 is adverse.

[0067] Furthermore, when an overtaking vehicle passes vehicle 2, and when a passing vehicle passes vehicle 2, rain or snow is kicked up, which can easily cause poor visibility in front of vehicle 2. Also, snow is kicked up for a longer period of time than rain. For this reason, in snowy weather, the period of poor visibility in front of vehicle 2 tends to be longer than in rainy weather. Therefore, in this embodiment, the adverse environment threshold when an overtaking or passing vehicle is present is made smaller than the adverse environment threshold when an overtaking or passing vehicle is not present, and the adverse environment threshold in snowy conditions is made smaller than the adverse environment threshold in rainy conditions, thereby enabling a more accurate determination of whether the surrounding environment of vehicle 2 is adverse in rainy or snowy weather.

[0068] Furthermore, in this embodiment, when it is detected that an overtaking vehicle or a passing vehicle is within a specified distance from the vehicle 2, the adverse environment threshold is changed according to the environmental conditions around the vehicle 2. Therefore, when the overtaking vehicle or passing vehicle is further than the specified distance from the vehicle 2, the adverse environment threshold is not changed. Consequently, in rainy or snowy weather, when the overtaking vehicle or passing vehicle is far from the vehicle 2, and therefore poor visibility in front of the vehicle 2 is unlikely to occur, the surrounding environment of the vehicle 2 is less likely to be determined to be an adverse environment. This prevents the unnecessary deactivation of the high beams illuminating the front of the vehicle 2.

[0069] Furthermore, in this embodiment, a camera 7 that images the area around the vehicle 2 is used to detect the environmental conditions around the vehicle 2 and the presence or absence of overtaking or passing vehicles. By using a camera 7 that images the area around the vehicle 2 in this way, detection of the environmental conditions around the vehicle 2 and detection of the presence or absence of overtaking or passing vehicles can be achieved with simple processing and at low cost.

[0070] It should be noted that the present invention is not limited to the above embodiments. For example, in the above embodiments, rain or snow is detected as the environmental condition around the vehicle 2, but in addition to rain or snow, conditions such as dense fog may also be detected.

[0071] Furthermore, in the above embodiment, the presence or absence of overtaking or passing vehicles is detected using a camera 7 that captures images of the area around the vehicle 2, but the system is not limited to this configuration. For example, the presence or absence of overtaking or passing vehicles may be detected using a distance measuring sensor such as LiDAR.

[0072] Furthermore, in the above embodiment, the rain or snow conditions are detected using a camera 7 that captures images of the area around the vehicle 2, but the system is not limited to this configuration. Instead of the camera 7, or together with the camera 7, the rain or snow conditions may be detected based on information about the operation status of the wipers. [Explanation of Symbols]

[0073] 2...Own vehicle, 7...Camera (surrounding situation detection unit, other vehicle detection unit), 11...Surrounding environment detection unit (surrounding situation detection unit), 12...Object detection unit (other vehicle detection unit), 13...Other vehicle determination unit (other vehicle detection unit), 14...Adverse environment determination unit, 20...Surrounding environment determination device, A...Overtaking vehicle (other vehicle), Pa...Adverse environment threshold for snow with no other vehicles (adverse environment threshold), Pb...Adverse environment threshold for rain with no other vehicles (adverse environment threshold), Qa...Adverse environment threshold for snow with other vehicles (adverse environment threshold), Qb...Adverse environment threshold for rain with other vehicles (adverse environment threshold).

Claims

1. A surrounding environment determination device for determining the surrounding environment of a vehicle when controlling the high beams of the vehicle, The surrounding conditions detection unit detects the environmental conditions around the vehicle, A vehicle detection unit that detects the presence or absence of other vehicles overtaking the vehicle or other vehicles passing the vehicle, The system includes a bad environment determination unit that determines whether the surrounding environment of the vehicle is a bad environment based on the surrounding environment conditions of the vehicle detected by the surrounding environment detection unit and the presence or absence of other vehicles detected by the other vehicle detection unit, The adverse environment determination unit determines whether the environment around the vehicle is an adverse environment by comparing the detection score of the environmental conditions around the vehicle with an adverse environment threshold corresponding to the environmental conditions around the vehicle. The aforementioned adverse environment threshold is different depending on the presence or absence of other vehicles in the surrounding environment determination device.

2. The aforementioned surrounding conditions detection unit detects rain or snow as the environmental conditions, The surrounding environment determination device according to claim 1, wherein the adverse environment threshold differs depending on the presence or absence of other vehicles and the condition of rain or snow.

3. The adverse environment threshold when other vehicles are present is smaller than the adverse environment threshold when other vehicles are not present. The surrounding environment determination device according to claim 2, wherein the adverse environment threshold for the snowy state is smaller than the adverse environment threshold for the rainy state.

4. The aforementioned other vehicle detection unit detects whether the other vehicle is within a specified distance from the vehicle itself, The surrounding environment determination device according to claim 1, wherein the adverse environment determination unit changes the adverse environment threshold according to the surrounding environmental conditions of the vehicle when the adverse environment determination unit detects that the other vehicle is within the specified distance from the vehicle itself.

5. The surrounding conditions detection unit uses a camera that captures images of the area around the vehicle to detect the environmental conditions around the vehicle. The surrounding environment determination device according to claim 1, wherein the other vehicle detection unit detects the presence or absence of the other vehicle using the camera.

Images