Aiming method and aiming system for vehicle headlight devices

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

Technical Field

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

Background Art

[0002] When a vehicle headlamp device is assembled to a vehicle body, aiming is performed to adjust the direction of the optical axis. Conventionally, in order to eliminate variations in aiming due to manual work, a system for automatically performing aiming has been proposed. This system irradiates a predetermined light distribution pattern on a screen installed in front of the vehicle by a lamp unit of the headlamp device in a fixed posture of the vehicle, acquires the deviation between the attention position of the light distribution pattern and the reference position in front of the vehicle corresponding thereto by the image information of an imaging device, and drives an optical axis displacement unit so that the attention position of the light distribution pattern and the reference position in front of the vehicle coincide with each other using the acquired deviation information (see Patent Document 1 below).

[0003] In addition, in recent vehicles, a light distribution variable system for vehicle headlamps called ADB (Adaptive Driving Beam) is installed. This light distribution variable system variably controls the light distribution pattern of high beam or low beam according to the acquired image of an in-vehicle camera that acquires an image in front of the vehicle in order to suppress glare for drivers of preceding vehicles or oncoming vehicles (Patent Document 2 below).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] In headlight systems equipped with the aforementioned adjustable beam pattern (ADB), calibration is required during aiming, such as when replacing the headlight system, to align the direction of the optical axis of the onboard camera that acquires the vehicle-front image used for ADB control with the direction of the optical axis of the headlight system. When this is done with the conventional aiming system described above, the first stage involves calibration by driving the optical axis displacement unit of the headlight system so that the point of interest in the beam pattern matches the reference position in front of the vehicle, and the second stage involves adjustment to align the optical axis of the onboard camera with the reference position in front of the vehicle. This results in a cumbersome two-stage adjustment process.

[0006] The present invention aims to address these circumstances. Specifically, in aiming a vehicle headlight device equipped with a variable light distribution system that controls the light distribution pattern using images acquired by an on-board camera, the present invention aims to enable simple and accurate adjustment of the optical axis while ensuring the accuracy of the variable light distribution system. [Means for solving the problem]

[0007] To solve these problems, the present invention provides, in part, an aiming method for a vehicle headlight device that controls the light distribution pattern of the headlight device using a forward image of the vehicle acquired by an on-board camera, comprising 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 with 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 to eliminate the deviation.

[0008] Furthermore, the present invention relates to an aiming system for a vehicle headlight device, comprising: an on-board camera that acquires an image of the front of the vehicle; a headlight device that illuminates 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 acquired by the on-board camera. The control device illuminates an aiming screen with the specific light distribution pattern of the headlight device, 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 from the on-board camera, and adjusts the optical axis of the headlight device to eliminate any deviation of the specific position from the adjusted coordinates. [Effects of the Invention]

[0009] According to the present invention, which has these features, in aiming a vehicle headlight device equipped with a variable light distribution system that controls the light distribution pattern using images acquired by an in-vehicle camera, the optical axis can be adjusted simply and accurately while ensuring the accuracy of the variable light distribution system. [Brief explanation of the drawing]

[0010] [Figure 1] An explanatory diagram showing an aiming system for a vehicle headlight device according to an embodiment of the present invention. [Figure 2] An explanatory diagram (front view) showing an example of the configuration of a headlight system. [Figure 3] An explanatory diagram showing the hardware configuration of the ECU. [Figure 4] An explanatory diagram showing the operation flow of the initial setting mode. [Figure 5] An explanatory diagram showing an image of a specific light distribution pattern (low beam light distribution pattern) during initial setup, along with the coordinates of a specific location. [Figure 6] An explanatory diagram showing an image of a specific light distribution pattern (high beam light distribution pattern) during initial setup, along with the coordinates of a specific location. [Figure 7] An explanatory diagram showing the operation flow of the optical axis adjustment operation mode. [Figure 8]An explanatory diagram showing an image of a specific light distribution pattern (low beam light distribution pattern) and specific position coordinates during optical axis adjustment. [Figure 9] A diagram illustrating the operation flow of the ADB control mode. [Modes for carrying out the invention]

[0011] 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.

[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 comprises an on-board camera 2, a headlight device 3, and a control device 10. Furthermore, as equipment for the aiming operation of the system 1, an aiming screen S is provided which positions the illuminated surface Sa facing the on-board camera 2 and the headlight device 3.

[0013] The on-board camera 2 is capable of capturing images of the front of at least the vehicle B, which is the vehicle itself. One example is a camera used to acquire detection images for ADAS (Advanced Driving Assistant System). When performing ADB control, the on-board camera 2 acquires images of the front of vehicle B in order to identify the vehicle ahead or oncoming vehicle that is the target of glare suppression. In addition, 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 illuminating the illuminated surface Sa of the aiming screen S in a darkroom.

[0014] The headlamp device 3 is mounted on the left and right ends in the front of the vehicle B. The right headlamp device 3R and the left headlamp device 3L of the headlamp device 3 are symmetrical about the left and right and have the same structure. In FIG. 2, only one side (the right headlamp device 3R) of the headlamp device 3 is shown. As shown in FIG. 2, the headlamp device 3 (the right headlamp device 3R and the left headlamp device 3L) includes a lamp housing 30, a low beam lamp unit 31, a high beam lamp unit 32, a heat sink member 33, a bracket 34, an optical axis adjustment device 35, a swivel device 36, and a lamp lens (not shown).

[0015] The optical axis adjustment device 35 is configured to adjust the attachment angle of the bracket 34 with respect to the lamp housing 30 in a three-point support manner, and can adjust the optical axes of the low beam lamp unit 31 and the high beam lamp unit 32. Further, the swivel device 36 includes a drive unit that rotationally drives a rotation shaft 36A by a control signal, and rotation of the rotation shaft 36A rotationally drives the low beam lamp unit 31 and the high beam lamp unit 32 supported by the heat sink member 33 around a vertical axis.

[0016] The swivel device 36 is an actuator that cooperates with the optical axis adjustment device 35 to adjust the optical axis of the headlamp device 3. Further, the swivel device 36 rotationally drives the low beam lamp unit 31 and the high beam lamp unit 32 around a vertical axis according to the output of a control device 10 based on signals from not only the in-vehicle camera 2 but also a steering angle sensor (not shown).

[0017] The low beam lamp unit 31 and the high beam lamp unit 32 can individually turn on and off, for example, a plurality of subdivided irradiation units (lighting segments), and can be constituted by 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 a plurality of in-vehicle ECUs (Electronic Control Units). One of the in-vehicle ECUs that make up the control unit 10 is the ECU 11 for in-vehicle camera control. Image data captured by the in-vehicle camera 2 is transmitted to the ECU 11, and the in-vehicle camera 2 is controlled by the output from the ECU 11. Another one of the ECUs that make up the control unit 10 is the ECU 12 for headlamp device control. The ECU 12 controls the lighting of the headlamp device 3 in each irradiation unit to form a specific light distribution pattern, and controls the optical axis adjustment device 35 and the swivel device 36, which are actuators for adjusting the optical axis of the headlamp device 3.

[0019] The ECUs 11 and 12 in the control device 10 are interconnected communicably via an in-vehicle network 13 such as CAN (Controller Area Network) or LIN (Local Interconnect Network), and are connected to a central gateway (CGW ECU) 14 as a relay device, and are also interconnected communicably with other in-vehicle ECUs not shown in the figure.

[0020] As shown in Figure 3, ECUs 11 and 12 are equipped with a CPU (Central Processing Unit) 100, ROM (Read Only Memory) 101, RAM (Random Access Memory) 102, and I / F (Interface) 103, and these hardware components are interconnected via a bus 104. The CPU 100 controls the operation of ECUs 11 and 12 by executing various programs stored in ROM 101. ROM 101 is a non-volatile memory. For example, ROM 101 stores programs executed by the CPU 100, information necessary for the CPU 100 to execute programs, etc. RAM 102 is a main memory such as DRAM (Dynamic Random Access Memory) or SRAM (Static Random Access Memory). For example, RAM 102 functions as a work area used by the CPU 100 when executing programs. I / F 103 controls the transmission and reception of information to and from external devices (for example, the in-vehicle camera 2 and the headlight device 3).

[0021] The control of 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 headlight device 3 by System 1 can be performed by the initial setting operation mode and the optical axis adjustment operation mode.

[0022] In the initial setup mode, as shown in Figure 1, vehicle B is positioned relative to the aiming screen S under initial setup conditions (such as the distance La from the aiming screen S to the front of vehicle B), and in a darkroom, a specific light distribution pattern is irradiated from the headlight device 3 onto the illuminated surface Sa of the aiming screen S, and the specific light distribution pattern irradiated onto the illuminated surface Sa is captured by the on-board camera 2.

[0023] During the initial setup of the initial operating mode, the optical axis adjustment between the headlight unit 3, which is properly mounted on vehicle B, and the on-board camera 2 is performed in advance. Therefore, if this initial state is maintained, the glare suppression function of the ADB control will function normally.

[0024] An example of the operation in the initial setup mode is explained in Figure 4. When the initial setup operation starts (START), the following steps are executed and the process ends (END). The initial setup conditions described above are prepared (STEP_S01). A specific light distribution pattern is set in the headlight device 3 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 onboard camera 2 (STEP_S03). By processing the acquired image, the coordinates of a specific position in the specific light distribution pattern are determined using the coordinates (XY 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 obtained in the initial setup mode correspond to the adjusted coordinates of the specific position.

[0025] Figure 5 illustrates a case where a specific light distribution pattern, the low beam light distribution pattern LBP, is set. The low beam light distribution pattern LBP, projected onto the aiming screen S by the headlight device 3, has a horizontal cutoff line CL1 and an oblique cutoff line CL2, and 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 coordinates E(X0,Y0) of the elbow point E, which is a specific position of the low beam light distribution pattern LBP, are determined by the XY coordinates set on the image G captured by the onboard camera 2, and these coordinates are stored as adjusted coordinates in the memory device of the control device 10.

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

[0027] Figure 6 illustrates a case where a specific light distribution pattern, HBP for high beams, is set. The HBP for high beams, projected onto the aiming screen S by the headlight 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 coordinates P(X00,Y00) of the intersection point P, which is a specific position of the HBP for high beams, are determined by the XY coordinates set on the image G captured by the onboard camera 2, and these coordinates are stored in the memory device of the control device 10 as adjusted coordinates.

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

[0029] The optical axis adjustment operation mode is an operation mode performed when replacing the headlight unit 3, etc. It detects the discrepancy between the coordinates of a specific position in the light distribution pattern (adjusted coordinates) stored in the initial setting operation mode and the coordinates of a specific position in the light distribution pattern obtained after replacing the headlight unit 3, and performs optical axis adjustment to eliminate that discrepancy.

[0030] An example of the operation mode of the optical axis adjustment operation mode is explained in Figure 7. When the optical axis adjustment operation starts (START), the following steps are performed and the process ends (END). The initial setting conditions described above are reproduced (STEP_S11). A specific light distribution pattern from the headlight device 3 is irradiated onto the illuminated surface Sa of the aiming screen S (STEP_S12). An image of the light distribution pattern irradiated onto the illuminated surface Sa of the aiming screen S is acquired by the onboard camera 2 (STEP_S13).

[0031] By processing the acquired image, the coordinates of a specific position in a specific light distribution pattern are determined using the coordinates (XY coordinates) set on the image (STEP_S14). Then, the difference between the coordinates of the specific position determined here and the coordinates of the specific position stored in the initial setting operation mode (adjusted coordinates) is detected (STEP_S15). If there is a difference (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 so that the difference is eliminated (STEP_S17). After that, the above steps S12 to S15 are performed, and when the difference is eliminated (STEP_S16:NO), the process is terminated (END).

[0032] When replacing the headlight unit 3, the optical axis of the headlight unit 3 may be misaligned compared to its initial installation. In this case, the initial setup conditions are reproduced, and the light distribution pattern of the headlight unit 3 projected onto the aiming screen S is captured by the on-board camera 2. When the coordinates of a specific position in the light distribution pattern are obtained, as shown in Figure 8, the coordinates of the specific position will shift from E(X0,Y0) to E(X1,Y1). Based on this shift, the optical axis is adjusted.

[0033] The ADB control operation mode is variable light distribution control of the headlight device 3 performed while the vehicle is in motion. As shown in Figure 9, when ADB control is started (START), the following steps are performed and the process ends (END). A forward image is acquired by the onboard camera 2 (STEP_S21). The acquired forward image is processed to identify the light-blocking target within the acquired image (STEP_S22). The light-blocking area on the acquired image is determined (STEP_S23).

[0034] Once the light-shielding area on the image is determined, the light distribution pattern of the headlight device 3 corresponding to the light-shielding area is determined (STEP_S24). Based on the determined light distribution pattern, the headlight device 3 is controlled to light up (STEP_S25). This enables proper ADB control that suppresses glare on the light-shielding target. If this ADB control is to be continued (STEP_S26:NO), the above steps STEP_S21 to S25 are repeated, and if the ADB control is to be terminated (STEP_S26:YES), the control operation is terminated (END).

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

[0036] In the embodiment described above, optical axis adjustment was performed in the optical axis adjustment operation mode. However, it is also possible to correct the position of the light distribution pattern in ADB control based on the deviation of a specific position of the light distribution pattern obtained in the optical axis adjustment operation mode, without performing optical axis adjustment. This allows for proper ADB control to suppress glare on the object being shielded, even when the optical axis of the headlight device 3 and the optical axis of the on-board camera 2 are misaligned.

[0037] Although 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 any design changes, etc., that do not depart from the gist 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]

[0038] 1: Aiming system (system), 2: In-car camera, 3: Headlight device, 3R: Right side headlight device, 3L: Left side headlight device, 10: Control unit, 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 component, 34: Bracket, 35: Optical axis adjustment device, 36: Swivel device, 36A: Rotation axis, 100: CPU, 101: ROM, 102: RAM, 103: I / F, 104: Bus, B: Vehicle, S: Aiming screen, Sa: Surface to be illuminated LBP: Low beam light distribution pattern, HBP: High beam light distribution pattern, CL1, CH1: Horizontal cutoff line, CL2: Diagonal cutoff line, CH2: Vertical cutoff line, G: Image

Claims

1. A method for aiming a vehicle headlight system, which controls the light distribution pattern of the headlight system based on a forward image of the vehicle acquired by an onboard camera, During initial setup, A step of illuminating an aiming screen with a specific light distribution pattern from the headlight device and acquiring an image of the specific light distribution pattern with the on-board camera. A step of determining the adjusted coordinates of a specific position in the specific light distribution pattern using coordinates set on the image of the in-vehicle camera, When replacing the aforementioned headlight device, A step of illuminating an aiming screen with the specific light distribution pattern of the headlight device and acquiring an image of the specific light distribution pattern with the on-board camera. A step of determining the coordinates of a specific position in the specific light distribution pattern using coordinates set on the image of the in-vehicle camera, and determining the deviation of the specific position from the adjusted coordinates, A method for aiming a vehicle headlight device, comprising the step of adjusting the optical axis of the headlight device to eliminate the aforementioned misalignment.

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

3. The aiming method for a vehicle headlight device according to claim 1, wherein the specified position is part or all of the cutoff line of the low beam light distribution pattern.

4. The aiming method for a vehicle headlight device according to claim 1, wherein the specified position is part or all of the cutoff line of the high beam light distribution pattern.

5. An in-vehicle camera that acquires images of the front of the vehicle, A headlight device that projects a specific light distribution pattern in front of the vehicle, The vehicle includes a control device that controls the light distribution pattern of the headlights based on the forward image of the vehicle acquired by the onboard camera. The control device is During initial setup, A specific light distribution pattern of the headlight device is projected onto the aiming screen, an image of the specific light distribution pattern is acquired by the on-board camera, and the adjusted coordinates of a specific position in the specific light distribution pattern are determined using coordinates set on the image from the on-board camera. When replacing the aforementioned headlight device, An aiming system for a vehicle headlight device, comprising: illuminating an aiming screen with the specific light distribution pattern of the headlight device; acquiring an image of the specific light distribution pattern with the on-board camera; determining the coordinates of a specific position in the specific light distribution pattern using coordinates set on the image from the on-board camera; and adjusting the optical axis of the headlight device to eliminate any deviation of the specific position from the adjusted coordinates.

Images