Headlight control device

Abstract

To suppress glare to a vehicle ahead or the like, even in headlights provided on a vehicle with a high ground height or headlights with high illuminance.　Provided is a headlight control device that controls a headlight unit. The headlight control device is provided with: a vehicle-to-vehicle distance acquisition unit that acquires a vehicle-to-vehicle distance (d) between the vehicle and a vehicle traveling ahead of the vehicle; and an irradiation control unit that, when the vehicle-to-vehicle distance falls below a predetermined distance (L1), reduces an irradiation quantity of low beams emitted by the headlight unit.

Description

Technical Field

[0001] The present invention relates to a headlamp control device that controls a headlamp mounted on a vehicle.

Background Art

[0002] A headlamp mounted on a vehicle irradiates light emitted from a light source forward of the vehicle through an optical system such as a lens, and can appropriately switch between a low beam and a high beam for irradiation (Patent Document 1). The irradiation ranges of the low beam and the high beam in the headlamp are adjusted in accordance with the regulations of the country in which the vehicle equipped with the headlamp travels. Generally, the low beam is adjusted so that the upper end (cut-off line) of the irradiation range is below the ground height of the headlamp in order to prevent glare from preceding vehicles or oncoming vehicles, and the high beam is adjusted to illuminate above and farther than the low beam.

[0003] In a vehicle equipped with a headlamp, for example, during night driving, usually the high beam is used to ensure the visibility of the driver, and when there are preceding vehicles such as preceding vehicles or oncoming vehicles or pedestrians, the low beam is used to suppress glare to the preceding vehicles or pedestrians. <C

[0004] Also, when performing light distribution control on the headlamp by ADB (Adaptive Driving Beam), during driving with the high beam, the presence and position of preceding vehicles and pedestrians are identified, and the irradiation range of the headlamp corresponding to the identified position is partially dimmed or turned off to suppress glare to the preceding vehicles and the like.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in vehicles with a high ride height or high-mounted headlights, the headlights are relatively higher off the ground, resulting in a higher illumination range for both low and high beams, which can easily cause glare on vehicles ahead. In particular, the high-intensity headlights that have become common in recent years tend to cause even more glare on vehicles ahead due to their higher illumination.

[0007] As mentioned above, low beams limit the illumination range downwards by adjusting the upper end of the illumination range to be below the ground clearance of the headlights. However, even with such low beams, glare may occur for vehicles ahead if the headlights are relatively high or if the headlights emit a large amount of light. On the other hand, if the illumination range of the low beams is adjusted downwards to compensate for the high ground clearance of the headlights, there is a risk that the driver's visibility will decrease. Furthermore, if the headlight's illumination range is located at a high position, even if the ADB partially dims or turns off the headlight's illumination range, glare suppression may not be sufficient.

[0008] The present invention aims to address these situations. Specifically, it aims to suppress glare to vehicles ahead, even when using headlights installed on vehicles with high ground clearance or headlights with high illumination. [Means for solving the problem]

[0009] To solve these problems, the optical axis adjustment device according to the present invention has the following configuration. In other words, one aspect of the present invention provides a headlight control device for controlling a headlight unit that emits light in front of a vehicle, comprising: a vehicle-to-vehicle distance acquisition unit that acquires the distance between the vehicle and a vehicle traveling in front of the vehicle; and an illumination control unit that reduces the amount of light emitted by the low beam of the headlight unit when the vehicle-to-vehicle distance falls below a predetermined distance L1. [Effects of the Invention]

[0010] With an optical axis adjustment device having these characteristics, even when the headlights are at a high ground clearance, the illumination range can be optimized and glare reduced. [Brief explanation of the drawing]

[0011] [Figure 1] This is an explanatory diagram showing a schematic configuration of a vehicle control system including a headlight ECU according to an embodiment of the present invention. [Figure 2] This is an explanatory diagram showing a schematic configuration of a headlight ECU according to an embodiment of the present invention. [Figure 3] This is a flowchart showing the control process of the headlight unit by the headlight ECU according to an embodiment of the present invention. [Figure 4] This flowchart shows the control process of the headlight unit by the headlight ECU according to a modified embodiment of the present invention. [Modes for carrying out the invention]

[0012] Embodiments of the present invention will now be described with reference to the drawings. In the following description, the same reference numerals in different figures indicate parts with the same function, and redundant explanations in each figure will be omitted as appropriate.

[0013] As shown in Figures 1 and 2, the headlight ECU (headlight control unit) 11 according to the embodiment of the present invention controls the headlight unit 21 (described later) that is mounted on the vehicle 100, and functions as part of the vehicle control system 1 mounted on the vehicle 100. The vehicle control system 1 includes a plurality of on-board ECUs (Electronic Control Units) 10 that control various electronic devices necessary for the operation of the vehicle 100, and one of the on-board ECUs 10 is a headlight It is equipped with a lighting ECU 11 and an external monitoring ECU 12, etc.

[0014] Each on-board ECU 10, headlight ECU 11, and external monitoring ECU 12 are connected to each other via an on-board network 3 such as CAN (Controller Area Network) or LIN (Local Interconnect Network), and are also connected to a central gateway (CGW) 4 acting as a relay device to constitute a vehicle control system 1. Each in-vehicle ECU 10, headlight ECU 11, and external monitoring ECU 12 is connected to the electronic device that is the target of their respective control, and controls the operation of the connected electronic device based on information (data) acquired from the in-vehicle network 3. 10 It outputs information indicating the status of connected electronic devices, such as their operating status, to the in-vehicle network 3.

[0015] Each in-vehicle ECU 10, headlight ECU 11, and external monitoring ECU 12 can be configured to include, for example, a processor such as a CPU (Central Processing Unit) or MPU (Micro Processing Unit), electrical circuits, and memory elements such as RAM (Random Access Memory) or ROM (Read Only Memory). 10 Some or all of the operations performed by this system can also be implemented using hardware such as ASICs (application-specific integrated circuits), FPGAs (field-programmable gate arrays), and GPUs (graphics processing units). In the following explanation, detailed descriptions and illustrations of electronic devices and the in-vehicle ECU 10, etc., that are not directly involved in the operation of the headlight ECU 11 will be omitted.

[0016] The headlight ECU 11 is connected to the headlight unit 21, which is located at the front of the vehicle 100, and controls the headlight unit 21. The headlight ECU 11 is also connected to an optical axis adjustment unit 22, which adjusts the optical axis of the headlight unit 21 according to instructions from the headlight ECU 11. Details of the headlight ECU 11 will be described later.

[0017] The headlight unit 21 is usually provided on the left and right sides in front of the vehicle respectively, and includes a low beam unit 21A that irradiates a low beam, which is called a passing headlight, and a high beam unit 21B that irradiates a high beam, which is called a driving headlight. The low beam unit 21A and the high beam unit 21B include a light source such as an LED, a reflector that guides the light emitted from the light source to the front of the vehicle 100, and a lens that irradiates the light emitted from the light source in a predetermined light distribution pattern (none of them are shown in the figure).

[0018] The low beam unit 21A irradiates a range below and closer to the vehicle 100 than the irradiation range of the high beam in order to suppress glare to vehicles and pedestrians around the vehicle 100. Therefore, the irradiation range of the low beam by the low beam unit 21A is set so that, for example, it is possible to confirm those that may become obstacles when the vehicle 100 is running, such as a vehicle or a pedestrian existing at a distance of about 40 m in front of the vehicle 100.

[0019] The high beam unit 21B irradiates up to a distance with a higher illuminance than the irradiation range of the low beam in order to improve the visibility of the driver when the vehicle 100 is running. Therefore, the irradiation range of the high beam by the high beam unit 21B is set so that, for example, it is possible to confirm those that may become obstacles when the vehicle 100 is running, such as a vehicle or a pedestrian existing at a distance of about 100 m in front of the vehicle 100.

[0020] The optical axis adjustment unit 22 includes a drive mechanism such as an electric actuator, for example, and adjusts the optical axis of the low beam unit 21A and the optical axis of the high beam unit 21B by operating the drive mechanism according to an instruction from the headlight ECU 11. By swinging the optical axis of the low beam unit 21A and the optical axis of the high beam unit 21B in the vertical direction and changing the angle of each optical axis with respect to the horizontal direction, each irradiation range can be displaced.

[0021] The external monitoring ECU 12, for example, constitutes part of the ADAS (Advanced Driver-Assistance Systems) that assists in the driving of the vehicle 100, and monitors the environment outside the vehicle 100 using a group of sensors including the camera 23, radar 24, and various other sensors included in the ADAS. Specifically, the external monitoring ECU 12 outputs images and various data acquired from the aforementioned group of sensors, or information obtained from these images and various data, such as moving objects including pedestrians and other vehicles around the vehicle, structures, road shapes, etc., as well as the distance and positional relationship between them and the vehicle, as surrounding information to the in-vehicle network 3.

[0022] Camera 23 is installed, for example, at the top of the windshield of vehicle 100 and in the center in the width direction of the vehicle, and captures a predetermined range in front of vehicle 100. Radar 24 is installed at multiple locations on vehicle 100 and measures the distance and direction to objects such as other vehicles, pedestrians, and structures located in front of, behind, and to the sides of vehicle 100 by transmitting radio waves of a predetermined wavelength and receiving the reflected waves.

[0023] (Regarding the headlight ECU) The headlight ECU 11, which functions as a headlight control device, will be described below. The headlight ECU 11 controls the headlight unit 21 by referring to information obtained from each of the above-mentioned in-vehicle ECUs via the in-vehicle network 3.

[0024] As shown in Figure 2, the headlight ECU 11 includes a CPU (Central Processing Unit) 111, a ROM 112, and a RAM 113. The CPU 111 performs various processes based on the program stored in the ROM 112. In this embodiment, the CPU 111 functions as the vehicle distance acquisition unit 121, the light distribution control unit 122, and the illumination control unit 123 shown in Figure 2 by reading the program stored in the ROM 112 into memory such as the RAM 113 and executing it. Hereinafter, the vehicle distance acquisition unit 121 , light distribution control unit 122, and The irradiation control unit 123 will now be described.

[0025] The vehicle distance acquisition unit 121 acquires the vehicle distance d between vehicle 100 and a vehicle traveling ahead of vehicle 100. The vehicle ahead includes oncoming vehicles traveling opposite to vehicle 100 and in the opposite direction to vehicle 100's direction of travel, and preceding vehicles traveling ahead of vehicle 100 in the same direction of travel.

[0026] The inter-vehicle distance acquisition unit 121 can, for example, acquire the inter-vehicle distance d, which is the distance between vehicle 100 and the vehicle in front, calculated based on an image captured by camera 23 over a predetermined range in front of vehicle 100, from the external monitoring ECU 12, or the inter-vehicle distance d measured based on transmitted and received waves from radar 24. The inter-vehicle distance acquisition unit 121 may also acquire the image captured by camera 23 via external monitoring ECU 12 and acquire the inter-vehicle distance d by performing predetermined image processing on the image.

[0027] The light distribution control unit 122 sets a light distribution pattern for the low beam unit 21A and the high beam unit 21B to illuminate their respective illumination ranges, and outputs a drive signal to the headlight unit 21 according to the set light distribution pattern. In addition, the light distribution control unit 122 can perform variable light distribution control called ADB (Adaptive Driving Beam) (hereinafter referred to as ADB control). For example, when the vehicle 100 is driving with its high beams on and there is a vehicle ahead, the light distribution control unit 122 sets the illumination range of the high beam unit 21B using ADB control, and sets a light distribution pattern that identifies an area within this illumination range corresponding to the position of the vehicle ahead as an area to be partially dimmed or blocked.

[0028] The illumination control unit 123 controls the headlight unit 21 to reduce the amount of light emitted by the low beam unit 21A when the vehicle-to-vehicle distance d between vehicle 100 and the vehicle in front, as acquired by the vehicle-to-vehicle distance acquisition unit 121, falls below a certain distance, that is, when the vehicle-to-vehicle distance d falls below a predetermined distance L1. The predetermined distance L1 can be set arbitrarily; for example, the predetermined distance L1 can be set to a distance shorter than the distance at which the switch from low beam to high beam occurs. In this way, the irradiation control unit 123 switches from high beam to low beam and irradiates with low beam, suppressing glare caused by the high beam for the vehicle in front. This also suppresses glare that may occur as the vehicle in front approaches vehicle 100 further.

[0029] The illumination control unit 123 can gradually or stepwise reduce the amount of light emitted by the low beam unit 21A according to the distance d between vehicles. In other words, the illumination control unit 123 can control the amount of light emitted by the low beam unit 21A to decrease as the distance d between vehicles decreases. By doing so, glare on the vehicle in front can be suppressed more effectively.

[0030] Furthermore, regardless of whether the aforementioned ADB control is being performed, the illumination control unit 123 controls the headlight unit 21 to reduce the amount of light emitted by the headlight unit 21 when the distance d between vehicle 100 and the vehicle in front falls below a predetermined distance L1.

[0031] The amount of light emitted by the headlight unit 21 can be appropriately determined based on the ground clearance of the headlight unit 21 on the vehicle 100, the illumination capacity of the headlight unit 21, etc., for example, the amount of light emitted before reduction, the amount of light emitted after reduction, etc., and stored in the ROM 112 of the headlight ECU 11.

[0032] Furthermore, the irradiation control unit 123 reduces the amount of light emitted by the low beam when the distance d between vehicles falls below a predetermined distance L1, and then in the following cases reduction The headlight unit 21 is controlled to return to the previous illumination intensity.

[0033] The irradiation control unit 123, when the vehicle ahead is a preceding vehicle traveling ahead of vehicle 100 in the same direction of travel as vehicle 100, and the distance d between the preceding vehicle and vehicle 100 exceeds a predetermined distance L2, reduction Return to the previous light intensity. The irradiation control unit 123, when the vehicle ahead is an oncoming vehicle of vehicle 100, after vehicle 100 and the oncoming vehicle have passed each other, reduction Return to the previous light intensity. In this way, glare from vehicle 100 to vehicles in front of it is suppressed while ensuring visibility for the driver of vehicle 100.

[0034] The control process performed by the headlight ECU 11 configured in this way over the headlight unit 21 will be explained below in accordance with the flowchart in Figure 3. Vehicle 100 drives while emitting either low beams or high beams from the headlight unit 21 according to a light distribution pattern set by the light distribution control unit 122 of the headlight ECU 11, in dark external environments such as at night. In this embodiment, it is explained that the predetermined distance L1 is set to a distance shorter than the vehicle-to-vehicle distance d at which the vehicle switches from high beams to low beams.

[0035] At this time, in vehicle 100, camera 23 captures an image of the area in front of vehicle 100 at predetermined intervals, and radar 24 measures the positional relationship and distance to other vehicles (including the vehicle in front) and pedestrians present around vehicle 100 at predetermined intervals, and outputs this information to external monitoring ECU 12. Based on the image output from camera 23 or the measurement results from radar 24, the external monitoring ECU 12 outputs the inter-vehicle distance d, which indicates the distance between vehicle 100 and the vehicle in front, if another vehicle is present in front of vehicle 100.

[0036] In the headlight ECU 11, the vehicle distance acquisition unit 121 acquires the vehicle distance d from the external monitoring ECU 12 via the in-vehicle network 3 (step S11), and when the vehicle distance d is a predetermined distance The system monitors whether the distance between vehicles falls below L1 (step S12). If the vehicle-to-vehicle distance d falls below a predetermined distance L1 (YES in step S12), the vehicle-to-vehicle distance acquisition unit 121 notifies the illumination control unit 123 of this fact, and the illumination control unit 123 controls the headlight unit 21 to reduce the amount of illuminated light (step S13).

[0037] At this time, the headlight unit 21 is illuminated by the low beam from the low beam unit 21A. hand The irradiation control unit 123 reduces the irradiation amount of the low beam to a level lower than the current irradiation amount. The vehicle distance acquisition unit 121 continues to acquire the vehicle distance d between the vehicle in front and vehicle 100 even after the irradiation amount has been reduced (step S14).

[0038] Vehicle distance acquisition unit 121 Based on the distance d between vehicles, the system determines whether vehicle 100 has passed the vehicle in front (step S15). If vehicle 100 has not passed the vehicle in front (NO in step S15), it determines whether the distance d between vehicles exceeds a predetermined distance L2 (step S16). If the distance d between vehicles exceeds the predetermined distance L2 (YES in step S16) or if vehicle 100 has passed the vehicle in front (YES in step S15), the system notifies the illumination control unit 123 of this fact, and the illumination control unit 123 controls the headlight unit 21 to return the reduced illumination light amount to the illumination light amount before reduction (step S17).

[0039] (modified version) For the low beam unit 21A and the high beam unit 21B, a light source unit including multiple segments arranged in a matrix and each of which can be independently controlled for illumination, or an array light source in which multiple light-emitting elements are arranged in a matrix can be applied. In this case, the light distribution control unit 122 can set a light distribution pattern that includes the illumination range of the low beam unit 21A and a specific area within this illumination range that corresponds to the position of the vehicle in front, etc., when the vehicle distance d between vehicle 100 and the vehicle in front, as acquired by the vehicle distance acquisition unit 121, falls below a certain distance, that is, when the vehicle distance d falls below a predetermined distance L1.

[0040] The illumination control unit 123 outputs a drive signal to the headlight unit 21 indicating the lighting state of each segment or each light-emitting element corresponding to the illumination range of the low beam unit 21A, according to the light distribution pattern set by the light distribution control unit 122. This makes it possible to control the low beam unit 21A so that a specific area within its illumination range corresponding to the position of a vehicle in front is partially dimmed or blocked.

[0041] Specifically, the irradiation control unit 123 controls the headlight unit 21 to reduce the amount of light emitted from each segment or light-emitting element corresponding to a specific area among the segments or light-emitting elements corresponding to the irradiation range of the low beam unit 21A, or to change each segment or light-emitting element corresponding to a specific area from an illuminated state to an unilluminated state.

[0042] The control process performed by the headlight ECU 11 on the headlight unit 21 in this modified example will be explained below in accordance with the flowchart in Figure 4. Vehicle 100 drives with either low beams or high beams illuminating from the headlight unit 21 according to a light distribution pattern set by the light distribution control unit 122 of the headlight ECU 11, in dark external environments such as at night. In this modified example, the predetermined distance L1 is set to a distance shorter than the vehicle-to-vehicle distance d at which the vehicle switches from high beams to low beams.

[0043] At this time, in vehicle 100, camera 23 captures an image of the area in front of vehicle 100 at predetermined intervals, and radar 24 measures the positional relationship and distance to other vehicles (including the vehicle in front) and pedestrians present around vehicle 100 at predetermined intervals, and outputs this information to external monitoring ECU 12. Based on the image output from camera 23 or the measurement results from radar 24, the external monitoring ECU 12 outputs the inter-vehicle distance d, which indicates the distance between vehicle 100 and the vehicle in front, if another vehicle is present in front of vehicle 100.

[0044] In the headlight ECU 11, the vehicle distance acquisition unit 121 acquires the vehicle distance d from the external monitoring ECU 12 via the in-vehicle network 3 (step S21), and when the vehicle distance d is a predetermined distance The system monitors whether the distance between vehicles falls below L1 (step S22). If the vehicle-to-vehicle distance d falls below a predetermined distance L1 (YES in step S22), the vehicle-to-vehicle distance acquisition unit 121 notifies the light distribution control unit 122 and the irradiation control unit 123 of this fact.

[0045] The light distribution control unit 122 sets a light distribution pattern that defines the illumination range of the low beam unit 21A and a specific area within this illumination range that corresponds to the position of a vehicle in front, etc., to be partially dimmed or blocked (step S23). The illumination control unit 123 controls the headlight unit 21 according to the light distribution pattern set by the light distribution control unit 122 to reduce the amount of light illuminating the specific area or to block the specific area (step S24).

[0046] The vehicle distance acquisition unit 121 continues to acquire the vehicle distance d between the vehicle in front and vehicle 100 even after reducing the amount of illuminated light (step S25). Vehicle distance acquisition unit 121 Based on the distance d between vehicles, it is determined whether vehicle 100 has passed the vehicle in front (step S26). If they have not passed each other (NO in step S26), it is determined whether the distance d between vehicles exceeds a predetermined distance L2 (step S27).

[0047] If the distance d between vehicles exceeds a predetermined distance L2 (YES in step S27) or if vehicle 100 passes a vehicle in front (YES in step S26), the illumination control unit 123 is notified of this fact, and the illumination control unit 123 controls the headlight unit 21 to return the amount of illumination light in the dimmed or shielded specific area back to the amount of illumination light before the dimming or shielding (step S28).

[0048] In this way, by reducing the amount of light illuminating a specific area corresponding to the vehicle ahead, or by blocking light from a specific area, illumination range Since it is possible to dim or block light in areas that may cause glare to vehicles ahead, even vehicles with high ground clearance for their headlights or high-intensity headlights can optimize the illumination range and suppress glare to oncoming or preceding vehicles.

[0049] Furthermore, when the vehicle ahead is an oncoming vehicle, if the vehicle 100 and the oncoming vehicle pass each other after the specific area has been dimmed or shielded, the amount of light illuminating the dimmed or shielded specific area is restored to its original level, thereby ensuring the visibility of the driver of the vehicle 100. Similarly, when the vehicle in front is a preceding vehicle, if, after dimming or shielding a specific area, the distance d between vehicles exceeds a predetermined distance L2 and a sufficient distance is secured so that the low-beam illumination from vehicle 100 does not cause glare to the preceding vehicle, the amount of light illuminating the dimmed or shielded specific area is restored to its original level, thereby ensuring the visibility of the driver of vehicle 100.

[0050] While embodiments of the present invention have been described in detail with reference to the drawings, the specific configurations are not limited to these embodiments, and any design changes, etc., that do not depart from the spirit of the present invention are also included. Furthermore, the above-described embodiments can be combined by utilizing each other's technologies, as long as there are no particular contradictions or problems in their purpose and configuration. [Explanation of Symbols]

[0051] 1: Vehicle control system, 3: In-vehicle network 11: Headlight ECU, 12: External monitoring ECU 21: Headlight unit, 21A: Low beam unit, 21B: High beam unit 22: Optical axis adjustment unit, 23: Camera, 24: Radar 121: Vehicle distance acquisition unit, 122: Light distribution control unit, 123: Irradiation control unit

Claims

1. A headlight control device that controls a headlight unit that illuminates light in front of the vehicle, A vehicle distance acquisition unit that acquires the distance between the vehicle itself and a vehicle traveling in front of the vehicle itself, A light distribution control unit that partially dims or blocks light in the range corresponding to the position of the vehicle ahead, The system includes an illumination control unit that reduces the amount of light emitted by the low beam from the headlight unit when the distance between vehicles falls below a first distance, The illumination control unit reduces the amount of light emitted from at least the low beam illumination range of the headlight unit, regardless of the operation of the light distribution control unit, when the distance between vehicles falls below a first distance.

2. The headlight control device according to claim 1, wherein the irradiation control unit dims or blocks light from a specific area of ​​the irradiation range of the low beam that corresponds to the vehicle in front.

3. The headlight unit includes an array light source in which multiple light-emitting elements are arranged in a matrix, The headlight control device according to claim 2, wherein the irradiation control unit controls the lighting state of the light-emitting element to dim or block light in the specific area.

4. The headlight unit comprises a light source unit including multiple segments, each of which can be independently controlled to light up. The headlight control device according to claim 2, wherein the irradiation control unit controls the lighting state of a plurality of segments to dim or block light in the specific area.

5. The headlight control device according to any one of claims 1 to 4, wherein the irradiation control unit gradually or stepwise reduces the amount of irradiated light according to the distance between vehicles when the distance between vehicles falls below a first distance.

6. If the preceding vehicle is a vehicle traveling ahead of the aforementioned vehicle in the same direction of travel as the aforementioned vehicle, The irradiation control unit, A headlight control device according to any one of claims 1 to 4, wherein when the distance between the preceding vehicle and the vehicle itself exceeds a second distance, the reduced amount of illuminating light is returned to the amount of illuminating light before the change.

7. If the vehicle ahead is an oncoming vehicle to the vehicle in question, The irradiation control unit, A headlight control device according to any one of claims 1 to 4, wherein after the vehicle and the oncoming vehicle have passed each other, the reduced amount of illumination light is returned to the amount of illumination light before the change.

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