Aiming method for automotive headlight device and aiming system

Abstract

The present invention makes it possible to perform optical axis adjustment simply and accurately while ensuring the precision of a variable light distribution system in the aiming of an automotive headlight device provided with a variable light distribution system for controlling a light distribution pattern according to an image acquired by an in-vehicle camera.　Provided is an aiming method for an automotive headlight device for controlling a light distribution pattern of the headlight device according to an image of the area ahead of a vehicle, said image being captured by an in-vehicle camera. This method includes: a step of emitting a specific light distribution pattern in the headlight device toward a screen for aiming and acquiring an image of the specific light distribution pattern by means of the in-vehicle camera; a step of obtaining the coordinates of a specific position in the specific light distribution pattern in coordinates set in the image from the in-vehicle camera and calculating the deviation of the specific position from adjusted coordinates; and a step of adjusting the optical axis of the headlight device so as to eliminate the deviation.

Description

Aiming method and aiming system for vehicle headlamp device

[0001] The present invention relates to an aiming method and an aiming system for a vehicle headlamp device.

[0002] When a vehicle headlamp device is installed on a vehicle body, it undergoes aiming to adjust the direction of the optical axis. Conventionally, an automatic aiming system has been proposed to eliminate variations in aiming due to manual work. This system, with the vehicle in a fixed position, uses a lamp unit of the headlamp device to project a predetermined light distribution pattern onto a screen installed in front of the vehicle, acquires image information from an imaging device to determine the deviation between a focal point of the light distribution pattern and a corresponding reference position in front of the vehicle, and uses the acquired deviation information to drive an optical axis displacement unit so that the focal point of the light distribution pattern coincides with the reference position in front of the vehicle (see Patent Document 1 below).

[0003] Furthermore, recent vehicles are equipped with a variable light distribution system for vehicle headlights called ADB (Adaptive Driving Beam). This variable light distribution system variably controls the light distribution patterns of high beams and low beams based on images captured by an on-board camera that captures images in front of the vehicle in order to reduce glare for drivers of preceding and oncoming vehicles (see Patent Document 2 below).

[0004] Japanese Patent No. 5331803 Japanese Patent Application Laid-Open No. 2014-136505

[0005] In a headlamp device equipped with the above-mentioned adjustable light distribution system (ADB), aiming, which is performed when replacing the headlamp device, requires calibration to align the direction of the optical axis of the on-board camera that captures the image in front of the vehicle used to control the ADB with the direction of the optical axis of the headlamp device. If this were to be done with the above-mentioned conventional aiming system, in a first step, calibration would be performed to drive the optical axis displacement unit of the headlamp device so that the focus position of the light distribution pattern coincides with a reference position in front of the vehicle, and then in a second step, adjustment would be required to align the optical axis of the on-board camera with the reference position in front of the vehicle, posing a problem of requiring two complicated adjustment steps.

[0006] The present invention addresses these circumstances by making it possible to easily and accurately adjust the optical axis while ensuring the accuracy of the variable light distribution system when aiming a vehicle headlamp device equipped with a variable light distribution system that controls the light distribution pattern based on an image captured by an onboard camera.

[0007] In order to solve such problems, one aspect of the present invention is an aiming method for a vehicle headlight device that controls the light distribution pattern of the headlight device using an image ahead of the vehicle acquired by an on-board camera, and includes the steps of: illuminating an aiming screen with a specific light distribution pattern of the headlight device and acquiring an image of the specific light distribution pattern using the on-board camera; determining the coordinates of a specific position in the specific light distribution pattern using coordinates set on the image of the on-board camera; and determining the deviation of the specific position from the adjusted coordinates; and adjusting the optical axis of the headlight device so as to eliminate the deviation.

[0008] In another aspect, the present invention is an aiming system for a vehicle headlight device, comprising an on-board camera that acquires an image in front of the vehicle, a headlight device that projects a specific light distribution pattern in front of the vehicle, and a control device that controls the light distribution pattern of the headlight device based on the image in front of the vehicle acquired by the on-board camera, wherein the control device projects the specific light distribution pattern of the headlight device onto an aiming screen, acquires an image of the specific light distribution pattern with the on-board camera, determines the coordinates of a specific position in the specific light distribution pattern using coordinates set on the image of the on-board camera, and adjusts the optical axis of the headlight device so as to eliminate any deviation from the adjusted coordinates of the specific position.

[0009] According to the present invention having these characteristics, when aiming a vehicle headlamp device equipped with a variable light distribution system that controls the light distribution pattern based on an image acquired by an on-board camera, it is possible to easily and accurately adjust the optical axis while ensuring the accuracy of the variable light distribution system.

[0010] 1 is an explanatory diagram showing an aiming system of a vehicle headlamp device according to an embodiment of the present invention. FIG. 1 is an explanatory diagram (front view) showing an example configuration of a headlamp device. FIG. 2 is an explanatory diagram showing the hardware configuration of an ECU. FIG. 2 is an explanatory diagram showing the operation flow of an initial setting operation mode. FIG. 3 is an explanatory diagram showing an image of a specific light distribution pattern (light distribution pattern for low beam) at the time of initial setting and the coordinates of a specific position. FIG. 4 is an explanatory diagram showing an image of a specific light distribution pattern (light distribution pattern for high beam) at the time of initial setting and the coordinates of a specific position. FIG. 4 is an explanatory diagram showing the operation flow of an optical axis adjustment operation mode. FIG. 5 is an explanatory diagram showing an image of a specific light distribution pattern (light distribution pattern for low beam) at the time of optical axis adjustment and the coordinates of a specific position. FIG. 5 is an explanatory diagram showing the operation flow of an ADB control operation mode.

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same reference numerals in different drawings denote parts with the same functions, and duplicated descriptions in each drawing will be omitted as appropriate.

[0012] An aiming system (hereinafter referred to as the system) 1 for a vehicle headlight device according to an embodiment of the present invention is mounted on a vehicle B, and includes an on-board camera 2, a headlight device 3, and a control device 10. The system 1 also includes an aiming screen S, which serves as equipment for the aiming operation of the system 1, and faces the illuminated surface Sa toward the on-board camera 2 and the headlight device 3.

[0013] The on-board camera 2 is capable of capturing at least an image ahead of the vehicle B, which is the vehicle itself, and is, for example, a camera for acquiring detection images used in an ADAS (Advanced Driving Assistant System). When performing ADB control, the on-board camera 2 acquires an image ahead of the vehicle B in order to identify a preceding vehicle or an oncoming vehicle that is a target for glare suppression. Furthermore, during initial setup or optical axis adjustment, the on-board camera 2 captures an image of the light distribution pattern of the headlight device 3 illuminated on the illuminated surface Sa of the aiming screen S in a darkroom.

[0014] The headlight devices 3 are mounted on both the left and right front ends of the vehicle B. The right headlight device 3R and the left headlight device 3L of the headlight devices 3 are bilaterally symmetrical and have the same structure. Fig. 2 shows only one side of the headlight device 3 (the right headlight device 3R). As shown in Fig. 2, the headlight devices 3 (the right headlight device 3R and the left headlight device 3L) include a lamp housing 30, a low beam lamp unit 31, a high beam lamp unit 32, a heat sink member 33, a bracket 34, a beam axis adjustment device 35, a swivel device 36, and a lamp lens (not shown).

[0015] The optical axis adjustment device 35 allows the mounting angle of the bracket 34 to be adjusted with three-point support relative to the lamp housing 30, and can adjust the optical axes of the low beam lamp unit 31 and the high beam lamp unit 32. The swivel device 36 also includes a drive unit that uses a control signal to drive the rotation shaft 36A to rotate, and the rotation of the rotation shaft 36A drives the low beam lamp unit 31 and the high beam lamp unit 32, which are supported on the heat sink member 33, to rotate about a vertical axis.

[0016] The swivel device 36 is an actuator that adjusts the optical axis of the headlamp device 3 in cooperation with the optical axis adjustment device 35. The swivel device 36 also drives the low beam lamp unit 31 and the high beam lamp unit 32 to rotate around a vertical axis in response to the output of the control device 10 based on a signal from a steering angle sensor (not shown) as well as a signal from the in-vehicle camera 2.

[0017] The low beam lamp unit 31 and the high beam lamp unit 32 can, for example, individually turn on and off a plurality of subdivided irradiation units (lighting segments), and can be constructed using MEMS (Micro Electro Mechanical Systems) devices such as an LED (Light Emitting Diode) array or a DMD (Digital Micromirror Device).

[0018] The control unit 10 is composed of multiple on-board ECUs (Electronic Control Units). One of the on-board ECUs constituting the control unit 10 is an ECU 11 for controlling an on-board camera. Image data captured by the on-board camera 2 is transmitted to the ECU 11, and the on-board camera 2 is controlled by output from the ECU 11. The other ECU constituting the control unit 10 is an ECU 12 for controlling a headlamp device. The ECU 12 controls the lighting of the headlamp device 3 in each illumination unit to form a specific light distribution pattern, and also controls a beam axis adjustment device 35 and a swivel device 36, which are actuators that adjust the beam axis of the headlamp device 3.

[0019] The ECUs 11 and 12 in the control device 10 are connected to each other via an in-vehicle network 13 such as a Controller Area Network (CAN) or a Local Interconnect Network (LIN) so that they can communicate with each other, and are also connected to a central gateway (CGWECU) 14 as a relay device, and are also connected to other in-vehicle ECUs (not shown) so that they can communicate with each other.

[0020] As shown in FIG. 3 , the ECUs 11 and 12 each include a central processing unit (CPU) 100, a read-only memory (ROM) 101, a random access memory (RAM) 102, and an interface (I / F) 103, which are interconnected via a bus 104. The CPU 100 controls the operation of the ECUs 11 and 12 by executing various programs stored in the ROM 101. The ROM 101 is a non-volatile memory. For example, the ROM 101 stores programs executed by the CPU 100 and information required for the CPU 100 to execute the programs. The RAM 102 is a main storage device such as a dynamic random access memory (DRAM) or a static random access memory (SRAM). For example, the RAM 102 functions as a work area used by the CPU 100 when executing the programs. The I / F 103 controls the transmission and reception of information to and from external devices (e.g., the in-vehicle camera 2 and the headlight device 3).

[0021] The control of the system 1 performed by the control device 10 includes at least an initial setting operation mode, an optical axis adjustment operation mode, and an ADB control operation mode. The aiming method of the headlamp device 3 by the system 1 can be performed in the initial setting operation mode and the optical axis adjustment operation mode.

[0022] In the initial setting operation mode, as shown in Figure 1, vehicle B is placed in relation to the aiming screen S under initial setting conditions (such as the distance La from the aiming screen S to the tip of vehicle B), and in a darkroom, a specific light distribution pattern is projected from the headlight device 3 onto the illuminated surface Sa of the aiming screen S, and the specific light distribution pattern projected onto the illuminated surface Sa is captured by the vehicle-mounted camera 2.

[0023] During the initial setting of the initial setting operation mode, the optical axes of the headlamp device 3 properly mounted on the vehicle B and the on-board camera 2 are adjusted in advance. Therefore, as long as this initial setting state is maintained, the glare suppression function of the ADB control functions normally.

[0024] An example of the operation of the initial setting operation mode will be described with reference to FIG. 4. When the initial setting operation starts (START), the following steps are executed to end the process (END). The initial setting conditions described above are prepared (STEP_S01). A specific light distribution pattern is set for the headlight device 3 on the illuminated surface Sa of the aiming screen S, and the specific light distribution pattern is projected onto the illuminated surface Sa of the aiming screen S (STEP_S02). An image of the light distribution pattern projected onto the illuminated surface Sa of the aiming screen S is acquired by the vehicle-mounted camera 2 (STEP_S03). The acquired image is processed to determine the coordinates of a specific position of the specific light distribution pattern using the coordinates (X-Y coordinates) set on the image (STEP_S04). The coordinate information of the determined specific position is stored in the storage device of the control device 10 (STEP_S05). The coordinates of the specific position determined in the initial setting operation mode correspond to the adjusted coordinates of the specific position.

[0025] 5 illustrates an example in which a low-beam light distribution pattern LBP is set as a specific light distribution pattern. The low-beam light distribution pattern LBP projected onto the aiming screen S by the headlamp device 3 has a horizontal cutoff line CL1 and an oblique cutoff line CL2, and has an elbow point E which is the intersection of the horizontal cutoff line CL1 and the oblique cutoff line CL2. In the illustrated example, the coordinate E (X0, Y0) of the elbow point E, which is a specific position of the low-beam light distribution pattern LBP, is determined using X-Y coordinates set on the image G captured by the on-board camera 2, and these coordinates are stored in the storage device of the control device 10 as adjusted coordinates.

[0026] Here, the specific position of the low beam light distribution pattern LBP is the elbow point E, but the specific position is not limited to this, and part or all of the horizontal cutoff line CL1, or part or all of the oblique cutoff line CL2, etc. can be set as the specific position.

[0027] 6 illustrates an example in which a high-beam light distribution pattern HBP is set as a specific light distribution pattern. The high-beam light distribution pattern HBP projected onto the aiming screen S by the headlamp device 3 has a horizontal cutoff line CH1 and a vertical cutoff line CH2, and has an intersection point P between the horizontal cutoff line CH1 and the vertical cutoff line CH2. In the illustrated example, the coordinate P (X00, Y00) of the intersection point P, which is a specific position of the high-beam light distribution pattern HBP, is determined using X-Y coordinates set on the image G captured by the on-board camera 2, and this coordinate is stored in the storage device of the control device 10 as an adjusted coordinate.

[0028] Here, the specific position of the high beam distribution pattern HBP is the intersection point P, but the specific position is not limited to this, and part or all of the horizontal cutoff line CH1, or part or all of the vertical cutoff line CH2, etc. can be set at the specific position.

[0029] The optical axis adjustment operation mode is an operation mode that is performed when, for example, the headlight device 3 is replaced, and detects any deviation that occurs between the coordinates (adjusted coordinates) of a specific position of the light distribution pattern stored in the initial setting operation mode and the coordinates of the specific position of the light distribution pattern determined after the headlight device 3 is replaced, and performs optical axis adjustment so that the deviation is eliminated.

[0030] An example of operation in the optical axis adjustment operation mode will be described with reference to Fig. 7. When the optical axis adjustment operation is started (START), the following steps are executed to end the process (END). The initial setting conditions described above are reproduced (STEP_S11). A specific light distribution pattern of the headlamp device 3 is projected onto the illuminated surface Sa of the aiming screen S (STEP_S12). An image of the light distribution pattern projected onto the illuminated surface Sa of the aiming screen S is acquired by the on-board camera 2 (STEP_S13).

[0031] The acquired image is processed to determine the coordinates of a specific position of a specific light distribution pattern using coordinates (X-Y coordinates) set on the image (STEP_S14). Then, a deviation between the determined coordinates of the specific position and the coordinates of the specific position (adjusted coordinates) stored in the initial setting operation mode is detected (STEP_S15). If a deviation is detected (STEP_S16: YES), the actuators for optical axis adjustment (optical axis adjustment device 35 and swivel device 36) are driven to adjust the optical axis to eliminate the deviation (STEP_S17). Thereafter, the aforementioned STEP_S12 to S15 are performed, and if the deviation is eliminated (STEP_S16: NO), the process ends (END).

[0032] When replacing the headlight device 3, the optical axis of the headlight device 3 may be misaligned from the initial installation. In this case, when the initial setting conditions are reproduced and the light distribution pattern of the headlight device 3 projected onto the aiming screen S is captured by the in-vehicle camera 2 and the coordinates of a specific position on the light distribution pattern are obtained, the coordinates of the specific position will be shifted from E(X0, Y0) to E(X1, Y1), as shown in Fig. 8, and the optical axis adjustment is performed based on this shift.

[0033] The ADB control operation mode is variable light distribution control of the headlamp device 3 performed while the vehicle is traveling. As shown in Fig. 9, when ADB control is started (START), the following steps are executed to end the process (END). A forward image is acquired by the on-board camera 2 (STEP_S21). The acquired forward image is subjected to image processing to identify shaded objects in the acquired image (STEP_S22). A shaded area on the acquired image is determined (STEP_S23).

[0034] Once the light-blocked area on the image is determined, a light distribution pattern for the headlight device 3 corresponding to the light-blocked area is determined (STEP_S24). The headlight device 3 is controlled to turn on based on the determined light distribution pattern (STEP_S25). This allows appropriate ADB control that suppresses glare on the light-blocked object to be performed. If such ADB control is to be continued (STEP_S26: NO), the above-described STEP_S21 to S25 are repeated. If ADB control is to be ended (STEP_S26: YES), the control operation is ended (END).

[0035] When ADB control is performed, the light distribution pattern of the headlight device 3 is determined so as to block (or reduce light) the shading area determined from the image acquired by the on-board camera 2. Even if a misalignment occurs between the optical axis of the headlight device 3 and the optical axis of the vehicle body or the on-board camera 2 due to replacement of the headlight device 3 or the like, by performing the optical axis adjustment operation mode described above, the optical axis of the headlight device 3 can be aligned with the optical axis of the on-board camera 2 without performing complicated two-stage adjustment, and appropriate ADB control can be performed to suppress glare on the shading target.

[0036] In the above-described embodiment, the optical axis adjustment is performed in the optical axis adjustment operation mode, but the position of the light distribution pattern in the ADB control may be corrected based on the deviation of a specific position of the light distribution pattern determined in the optical axis adjustment operation mode without performing the optical axis adjustment. In this way, even when the optical axis of the headlamp device 3 and the optical axis of the in-vehicle camera 2 are misaligned, appropriate ADB control can be performed to suppress glare on a light-blocking target.

[0037] Although the embodiments of the present invention have been described in detail above with reference to the drawings, the specific configurations are not limited to these embodiments, and the present invention also includes design changes within the scope of the present invention. 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 purposes, configurations, etc.

[0038] 1: Aiming system (system), 2: In-vehicle camera, 3: Headlight device, 3R: Right-side headlight device, 3L: Left-side headlight device, 10: Control device, 11, 12: ECU, 13: In-vehicle network, 14: Central gateway, 30: Lamp housing, 31: Low-beam lamp unit, 32: High-beam lamp unit, 33: Heat sink member, 34: Bracket, 35: Optical axis adjustment device, 36: Swivel device, 36A: Rotating shaft, 100: CPU, 101: ROM, 102: RAM, 103: I / F, 104: Bus, B: Vehicle, S: Aiming screen, Sa: Illuminated surface, LBP: Low-beam light distribution pattern, HBP: High-beam light distribution pattern, CL1, CH1: Horizontal cutoff line, CL2: Oblique cutoff line, CH2: Vertical cutoff line, G: Image

Claims

1. An aiming method for a vehicle headlight device that controls the light distribution pattern of the headlight device using an image of the front of the vehicle captured by an on-board camera, comprising the steps of: projecting a specific light distribution pattern of the headlight device onto an aiming screen and capturing an image of the specific light distribution pattern using the on-board camera; determining the coordinates of a specific position in the specific light distribution pattern using coordinates set on the image of the on-board camera, and determining a deviation of the specific position from the adjusted coordinates; and adjusting the optical axis of the headlight device so as to eliminate the deviation.

2. The aiming method for a vehicle headlamp device according to claim 1, wherein the specific position is an elbow point of a low beam light distribution pattern.

3. The aiming method for a vehicle headlamp device according to claim 1, wherein the specific position is a part or the whole of a cut-off line of a low beam light distribution pattern.

4. The aiming method for a vehicle headlamp device as described in claim 1, wherein the specific position is a part or all of a cut-off line of a high beam light distribution pattern.

5. An aiming system for a vehicle headlight device comprising: an on-board camera that captures an image of the front of the vehicle; a headlight device that projects a specific light distribution pattern in front of the vehicle; and a control device that controls the light distribution pattern of the headlight device based on the image of the front of the vehicle captured by the on-board camera, wherein the control device projects the specific light distribution pattern of the headlight device onto an aiming screen, captures an image of the specific light distribution pattern using the on-board camera, determines the coordinates of a specific position in the specific light distribution pattern using coordinates set on the image of the on-board camera, and adjusts the optical axis of the headlight device so as to eliminate any deviation from the adjusted coordinates of the specific position.

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