Headlight control device

Abstract

The present invention suppresses glare by achieving an appropriate illumination range even in a vehicle having a high headlight ground level.　Provided is a headlight control device (11) for controlling a headlight unit, the headlight control device comprising: a vehicle (100) to which a headlight unit (21) is mounted; an inter-vehicular distance acquisition part (121) that acquires an inter-vehicular distance (d) to a preceding vehicle traveling in front of this vehicle; and an illumination control part (123) that displaces, when the inter-vehicular distance becomes shorter than a predetermined distance (L1), out of an illumination range of a low beam and an illumination range of a high beam set by the headlight unit, at least the illumination range of the low beam downward by a predetermined amount.

Description

Technical Field

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

Background Art

[0002] A headlight mounted on a vehicle irradiates light emitted from a light source in front of the vehicle through an optical system such as a lens, and can irradiate by appropriately switching between a low beam and a high beam (Patent Document 1). Each irradiation range of the low beam and the high beam in the headlight is adjusted according to the regulations of the country in which the vehicle equipped with the headlight 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 headlight in order to prevent glare from the preceding vehicle or oncoming vehicle, and the high beam is adjusted to illuminate above and farther than the low beam.

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

[0004] Also, when performing light distribution control on the headlight by ADB (Adaptive Driving Beam) while driving on the high beam, the presence and position of preceding vehicles and pedestrians are identified, and the irradiation range of the headlight 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 for vehicles ahead.

[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, if the headlights are relatively high, glare may be generated for vehicles ahead. 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 optimize the illumination range and suppress glare even on vehicles with high headlight ground clearance. [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 illuminates a predetermined range in front of a vehicle, comprising: a vehicle distance acquisition unit that acquires the distance between the vehicle equipped with the headlight unit and a vehicle traveling in front of the vehicle; and an illumination control unit that, when the vehicle distance falls below a predetermined distance L1, displaces at least the low beam illumination range of the headlight unit downward by a predetermined amount. [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. [Modes for carrying out the invention]

[0012] Embodiments of the present invention will be described below 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 are provided with 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 that is below the high beam irradiation range and close to the vehicle 100 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 in front or a pedestrian existing at a distance of about 40 m in front of the vehicle 100.

[0019] The high beam unit 21B irradiates far away with a higher illuminance than the low beam irradiation range 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 in front or a pedestrian existing at a distance of about 100 m in front of the vehicle 100.

[0020] The optical axis adjustment unit 22 is provided with 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 by the optical axis adjustment unit 22 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 uses ADB control to set the light distribution pattern so that the area of ​​the illumination range of the high beam unit 21B corresponding to the position of the vehicle ahead is partially dimmed or blocked.

[0028] When the vehicle-to-vehicle distance d between vehicle 100 and the vehicle ahead, 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 illumination control unit 123 controls the headlight unit 21 to displace the illumination range downward. At this time, the illumination control unit 123 displaces either only the low beam illumination range, or both the low beam illumination range and the high beam illumination range, downward by a predetermined amount.

[0029] Furthermore, regardless of whether the aforementioned ADB control is being performed, the illumination control unit 123 controls the headlight unit 21 to shift the illumination range downward when the distance d between vehicle 100 and the vehicle in front falls below a predetermined distance L1.

[0030] The predetermined amounts mentioned above, namely the displacement amounts of the low beam illumination range and the high beam illumination range, can be predetermined based on the ground clearance of the headlight unit 21 on the vehicle 100 and stored in the ROM 112 of the headlight ECU 11. In addition, the illumination control unit 123 can acquire the ground clearance of the headlight unit 21 during driving each time, based on the mounting position of the headlight unit 21 on the vehicle 100 and information obtained from a vehicle height sensor (not shown), and calculate the displacement amounts of each illumination range so that the low beam illumination range and the high beam illumination range are appropriate illumination ranges.

[0031] The irradiation control unit 123 can displace each irradiation range by adjusting the optical axes of the low beam unit 21A and the high beam unit 21B. In this case, the irradiation control unit 123 determines the adjustment amount for the optical axis of the low beam unit 21A and the optical axis of the high beam unit 21B, respectively, according to the amount of displacement of each irradiation range, and outputs a drive signal indicating each adjustment amount to the optical axis adjustment unit 22.

[0032] Furthermore, the illumination control unit 123 controls the headlight unit 21 to return each illumination range to its original position if, after displacing only the low beam illumination range or both the low beam illumination range and the high beam illumination range downwards due to the vehicle-to-vehicle distance d falling below a predetermined distance L1, in the following cases:

[0033] The irradiation control unit 123 returns each irradiation range to its position before displacement if the vehicle in front is a preceding vehicle traveling ahead of vehicle 100 in the same direction of travel, and the distance d between the preceding vehicle and vehicle 100 exceeds a predetermined distance L2. If the vehicle ahead is an oncoming vehicle to vehicle 100, the irradiation control unit 123 returns each irradiation range to its position before displacement after vehicle 100 and the oncoming vehicle have passed each other. 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.

[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 shift the illumination range downward (step S13).

[0037] In this case, if only the low beam from the low beam unit 21A is illuminating the headlight unit 21, the illumination range of the low beam will be shifted downward. Alternatively, if the high beam is illuminating the headlight while partially blocking the illumination range by ADB control, the illumination range of the high beam may be shifted downward.

[0038] The vehicle-to-vehicle distance acquisition unit 121 continues to acquire the vehicle-to-vehicle distance d between the vehicle in front and vehicle 100 even after displacing the illumination range downward (step S14). Based on the vehicle-to-vehicle distance d, it is determined whether or not vehicle 100 has passed the vehicle in front (step S15). If they have not passed each other (NO in step S15), it is determined whether or not the vehicle-to-vehicle distance d exceeds a predetermined distance L2 (step S16). If the vehicle-to-vehicle distance d exceeds the predetermined distance L2 (YES in step S16) or if vehicle 100 has passed the vehicle in front (YES in step S15), the illumination control unit 123 is notified accordingly, and the illumination control unit 123 controls the headlight unit 21 to return the illumination range that has been displacing downward to the illumination range before the displacement (step S17).

[0039] (modified version) A light source with multiple light-emitting elements arranged in a matrix can be used as the light source for the low beam unit 21A and the high beam unit 21B. In this case, the irradiation control unit 123 outputs a drive signal to the headlight unit 21 indicating whether each light-emitting element is lit or not, according to the light distribution pattern set for the respective irradiation ranges of the low beam unit 21A and the high beam unit 21B.

[0040] Furthermore, when the irradiation control unit 123 displaces each irradiation range, it controls the lighting state of each light-emitting element according to the amount of displacement, thereby displacing the irradiation range of the low beam and the high beam. In other words, the irradiation control unit 123 displaces the irradiation range of the low beam and the high beam by changing the light distribution patterns of the low beam unit 21A and the high beam unit 21B set by the light distribution control unit 122.

[0041] Specifically, the irradiation control unit 123 sets a corrected light distribution pattern in which, among the multiple light-emitting elements of the light sources of the low beam unit 21A and the high beam unit 21B, the light-emitting elements that were illuminating the upper part of the irradiation range in the light distribution pattern before displacement are changed from an illuminated state to an unilluminated state, and the light-emitting elements located even lower than the light-emitting elements that were illuminating the lower part of the irradiation range are changed from an unilluminated state to an illuminated state.

[0042] In this way, the irradiation control unit 123 sets a corrected light distribution pattern such that the irradiation range of the low beam and the irradiation range of the high beam are lower, and the irradiation range can be displaced by controlling the headlight unit 21 based on this corrected light distribution pattern.

[0043] According to the above-described embodiment and its modified form, when the distance d between the vehicle itself, i.e., vehicle 100, and the vehicle in front falls below a predetermined distance L1, the illumination range of the low beam is shifted downwards. Therefore, even for vehicles with high headlight ground clearance, the illumination range can be optimized to suppress glare to oncoming or preceding vehicles.

[0044] If the vehicle ahead is an oncoming vehicle, the illumination range is shifted downwards, and then returned to its original position when vehicle 100 and the oncoming vehicle pass each other, thereby ensuring visibility for the driver of vehicle 100. Similarly, if the vehicle in front is a preceding vehicle, and after the illumination range is displaced downwards, if the distance d between vehicles exceeds a predetermined distance L2 and a sufficient distance is secured so that the low beam or high beam illumination from vehicle 100 does not cause glare to the preceding vehicle, the displaced illumination range is returned to its original position, thereby ensuring the visibility of the driver of vehicle 100.

[0045] 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]

[0046] 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 a predetermined range in front of the vehicle, A vehicle distance acquisition unit that acquires the distance between the vehicle equipped with the headlight unit and a vehicle traveling in front of the vehicle, When the distance between vehicles falls below a first distance, the illumination control unit displaces at least the low beam illumination range of the headlight unit downward by a predetermined amount, and The system includes a light distribution control unit that partially dims or blocks light in the range of the high beam illumination area corresponding to the position of the vehicle in front, The illumination control unit, when the distance between vehicles falls below a first distance, displaces at least the low beam illumination range of the headlight unit downward by a predetermined amount, regardless of whether control by the light distribution control unit is being performed.

2. A headlight control device for controlling a headlight unit that illuminates a predetermined range in front of the vehicle, A vehicle distance acquisition unit that acquires the distance between the vehicle equipped with the headlight unit and a vehicle traveling in front of the vehicle, When the distance between vehicles falls below a first distance, the illumination control unit displaces at least the low beam illumination range of the headlight unit downward by a predetermined amount calculated based on the ground clearance of the headlight unit, among the low beam illumination range and high beam illumination range of the headlight unit. The system includes a light distribution control unit that partially dims or blocks light in the range of the high beam illumination area corresponding to the position of the vehicle in front, The illumination control unit, when the distance between vehicles falls below a first distance, displaces at least the low beam illumination range of the headlight unit downward by a predetermined amount, regardless of the operation of the light distribution control unit.

3. The headlight control device according to claim 1 or 2, wherein the irradiation control unit adjusts the optical axis of the headlight unit to displace the irradiation range of the low beam.

4. The headlight unit comprises a light source having multiple light-emitting elements arranged in a matrix, The headlight control device according to claim 1 or 2, wherein the irradiation control unit displaces the irradiation range of the low beam by controlling the lighting state of the light-emitting element.

5. 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, The headlight control device according to claim 1 or 2, wherein when the distance between the preceding vehicle and the vehicle itself exceeds a second distance, the headlight control device returns the downwardly displaced illumination range of the low beam and high beam illumination range of the headlight unit back to its position before displacement.

6. If the vehicle ahead is an oncoming vehicle to the vehicle in question, The irradiation control unit, The headlight control device according to claim 1 or 2, wherein, after the vehicle and the oncoming vehicle have passed each other, the illumination range of the headlight unit, which has been displaced downward, is returned to its position before displacement, as described above.

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