Light distribution control device for vehicle headlight

Abstract

This light distribution control device for a vehicle headlight sets a light-blocking range with respect to an oncoming vehicle on the basis of a frontward image of an ego vehicle, the image having been acquired by an on-vehicle camera. The light distribution control device ensures that no unpleasant glare is imparted to the oncoming vehicle, even at a time when the oncoming vehicle is out of the viewing angle of the camera.　if the oncoming vehicle is recognized in the frontward image on the basis of the ego-vehicle frontward image which has been acquired by the on-vehicle camera, the light distribution control device for a vehicle headlight specifies a light-blocking range corresponding to the recognized oncoming vehicle and performs light distribution control, and if the oncoming vehicle is not recognized in the frontward image and the light distribution control is being performed, the light distribution control device for a vehicle headlight predicts the location of the oncoming vehicle and continues the light distribution control until it is confirmed that the ego vehicle and the oncoming vehicle have passed each other.

Description

Light distribution control device for vehicle headlights

[0001] The present invention relates to a light distribution control device for a vehicle headlamp.

[0002] Conventionally, in light distribution control of vehicle headlights in ADB (Adaptive Driving Beam), in order to prevent glare on oncoming vehicles approaching the vehicle relatively close to the vehicle, it is known to obtain information indicating the movement of the oncoming vehicle, derive a light blocking range for the vehicle headlights based on the obtained information indicating the movement, and control the light distribution state of the vehicle headlights in accordance with the derived light blocking range (see Patent Document 1 below).

[0003] JP 2019-89386 A

[0004] According to the above-mentioned conventional technology, information indicating the movement of an oncoming vehicle is obtained based on an image of the area in front of the vehicle captured by an onboard camera. This allows for continuous acquisition of information indicating the ever-changing movement of the oncoming vehicle as long as the oncoming vehicle is within the field of view of the onboard camera. However, if the oncoming vehicle moves out of the field of view of the onboard camera, it becomes impossible to obtain information indicating the movement of the oncoming vehicle, and it becomes impossible to derive the shaded area of ​​the vehicle headlights.

[0005] For this reason, in conventional technology, there is a time when the light distribution control by the ADB is released after the oncoming vehicle moves out of the field of view of the onboard camera while the oncoming vehicle is approaching the vehicle and passing by it, and during that time, there is a problem in that glare is generated for the oncoming vehicle.

[0006] The present invention addresses this problem by providing a light distribution control device for vehicle headlights that sets a light blocking range for oncoming vehicles based on an image of the area ahead of the vehicle captured by an onboard camera, preventing oncoming vehicles from receiving unpleasant glare even when the oncoming vehicle moves out of the angle of view of the onboard camera.

[0007] In order to solve these problems, the present invention has the following configuration: A light distribution control device for a vehicle headlamp that sets a light blocking range for an oncoming vehicle based on an image of the vehicle ahead captured by an on-board camera, and if the oncoming vehicle is recognized in the forward image, the light distribution control device specifies a light blocking range in accordance with the recognized oncoming vehicle and performs light distribution control, and if the oncoming vehicle is not recognized in the forward image, and if light distribution control is in progress, predicts the position of the oncoming vehicle and continues light distribution control until it is confirmed that the vehicle ahead and the oncoming vehicle have passed each other.

[0008] According to the present invention having such characteristics, even when an oncoming vehicle moves out of the field of view of the onboard camera, light distribution control that specifies the shading range can be continued, thereby suppressing unpleasant glare for oncoming vehicles.

[0009] 1 is an explanatory diagram showing an example of the configuration of a light distribution control device for a vehicle headlamp according to an embodiment of the present invention; an explanatory diagram showing the hardware configuration of an ECU; an explanatory diagram showing an example of the control flow of a light distribution control device for a vehicle headlamp according to an embodiment of the present invention; an explanatory diagram showing a front image acquired by an in-vehicle camera and the light irradiation range of a headlamp device; an explanatory diagram showing the movement over time of an oncoming vehicle recognized in a front image and the corresponding light blocking range identified; an explanatory diagram showing an example of a light blocking range within the light irradiation range identified when an oncoming vehicle deviates from the angle of view of the front image; and an explanatory diagram showing another example of a light blocking range within the light irradiation range identified when an oncoming vehicle deviates from the angle of view of the front image.

[0010] 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.

[0011] As shown in FIG. 1 , a light distribution control device 1 for a vehicle headlamp according to an embodiment of the present invention is mounted on a vehicle B, and includes an on-board camera 2 , a headlamp device 3 , and a control device 10 .

[0012] The on-board camera 2 is capable of acquiring at least a forward image 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 light distribution control, the on-board camera 2 acquires a forward image of the vehicle B in order to identify a preceding vehicle, an oncoming vehicle, etc., which are targets for glare suppression.

[0013] The headlight devices 3 are mounted on both the left and right front ends of the vehicle B and form a predetermined light illumination range in front of the vehicle B. The right and left headlight devices of the headlight devices 3 are bilaterally symmetrical and have the same structure. The headlight devices 3 include, for example, a lamp housing, a lamp unit, and a lamp lens. The lamp unit can individually turn on and off a plurality of subdivided illumination units (lighting segments), and can be configured, for example, with a light-emitting diode (LED) array or a micro-electro-mechanical systems (MEMS) device such as a digital micromirror device (DMD).

[0014] The control device 10 is composed of multiple on-board ECUs (Electronic Control Units). One of the on-board ECUs constituting the control device 10 is an ECU 11 for an on-board camera. Image data acquired by the on-board camera 2 is transmitted to the ECU 11, and the ECU 11 performs image processing and the like on the transmitted image data. The on-board camera 2 is controlled by the output from the ECU 11. Another ECU constituting the control device 10 is an ECU 12 for a headlamp device. The ECU 12 controls the lighting of the headlamp device 3 in each illumination unit, thereby performing light distribution control to form a specific light distribution pattern.

[0015] 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.

[0016] As shown in FIG. 2 , 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).

[0017] 3 shows an example of a processing flow of ADB light distribution control by the control device 10. Here, a case is shown in which a specific oncoming vehicle is recognized from a forward image acquired by the onboard camera 2. When the control is started, a forward image of vehicle B acquired by the onboard camera 2 is input to the ECU 11 ("forward image acquisition": step S01). The ECU 11 processes the acquired forward image and performs a recognition process to determine whether or not an oncoming vehicle is present in the image ("oncoming vehicle recognition": step S02).

[0018] 4, when a specific oncoming vehicle G1 is recognized in the forward image G (step S02: YES in FIG. 3), the ECU 12 for the headlight device 3 identifies a portion corresponding to the oncoming vehicle G1 within the light irradiation range L of the headlight device 3, and identifies a light-blocked area S1 therein ("light-blocked area identification": step S03). Then, when the light-blocked area S1 is identified, the ECU 12 performs light distribution control (setting of a light distribution pattern) so that light is not irradiated into the identified light-blocked area S1 within the light irradiation range L of the headlight device 3 ("light distribution control": step S04).

[0019] The processes of steps S01 to S04 are executed at predetermined control timings as needed. As a result, as time passes, when a specific oncoming vehicle G1 approaches vehicle B, a light-blocking area S2 is identified at a position different from the light-blocking area S1 as the oncoming vehicle G1 moves in the acquired forward image G, as shown in FIG. 5 .

[0020] 6, the oncoming vehicle G1 moves out of the angle of view of the forward image G. In this case, the image processing by the ECU 11 will no longer be able to recognize the oncoming vehicle G1 that was recognized up until the previous processing. Therefore, the process in step S02 in FIG. 3 becomes "NO," and the process by the control device 10 proceeds to step S05.

[0021] In step S05, it is determined whether the light distribution control in step S04 was executed in the previous process (whether the light distribution control is in progress). If it is determined that the light distribution control is not in progress (step S05: NO), this means that the oncoming vehicle G1 was not present from the beginning, and in this case, the subsequent process is skipped and the process is terminated.

[0022] When it is determined in step S05 that light distribution control is in progress (step S05: YES), this corresponds to the case where the oncoming vehicle G1 recognized in the forward image G has moved out of the angle of view of the forward image G, as shown in FIG. 6 . In this case, the position of the oncoming vehicle is predicted in the next step ("oncoming vehicle position prediction": step S06). The prediction of the oncoming vehicle position can be performed based on the relative speed between the oncoming vehicle G1 recognized during light distribution control and the subject vehicle. The relative speed between the oncoming vehicle G1 and the subject vehicle (vehicle B) can be calculated from the change in the distance between the vehicles based on the positional relationship between the oncoming vehicle G1 and the subject vehicle, which is detected in three dimensions by various sensors mounted on vehicle B.

[0023] Furthermore, the position of the oncoming vehicle G1 can be predicted based on the movement trajectory of the oncoming vehicle G1 recognized in the forward image G during light distribution control. Specifically, by comparing the position of the oncoming vehicle G1 in the forward image G recognized in the processing before last (see FIG. 4 ) with the position of the oncoming vehicle G1 in the forward image G recognized in the previous processing (see FIG. 5 ), and taking into consideration the time difference between the control timing of the processing before last and the previous processing, the movement distance and movement direction of the position, the movement trajectory of the oncoming vehicle G1 can be grasped, and the position of the oncoming vehicle G1 can be predicted on an extension of that trajectory.

[0024] After predicting the position of the oncoming vehicle G1 after it has left the angle of view of the forward image G, the next step is to confirm whether or not the host vehicle and the oncoming vehicle G1 have passed each other ("passing confirmation": step S07). The passing confirmation here can be confirmed by checking whether the predicted position of the oncoming vehicle G1 has left the light irradiation range L of the headlamp device 3. If the position of the oncoming vehicle G1 has left the light irradiation range L (step S07: YES), there is no longer a possibility that glare will be caused to the oncoming vehicle G1, so the light distribution control is released from shading in the next step (step S08), and the process ends.

[0025] Then, if it is determined during the passing check that the predicted position of the oncoming vehicle G1 is not outside the light irradiation range L (step S07: NO), the light blocking range is identified taking into account the predicted position of the oncoming vehicle G1 (step S03), and light distribution control is continued in accordance with the identified light blocking range (step S04).

[0026] In this case, for example, as shown in Fig. 6, a shaded area S3 is specified within the light irradiation area L so as to surround the predicted position of the oncoming vehicle G1. Alternatively, as shown in Fig. 7, a shaded area S30 may be specified within the light irradiation area L by enlarging the shaded area S2 specified immediately before the oncoming vehicle G1 moves out of the angle of view of the forward image G. In this case, it is preferable that the enlargement direction be two different directions according to the movement trajectory of the oncoming vehicle G1 so as to include the predicted position of the oncoming vehicle G1.

[0027] Here, the processing when a specific oncoming vehicle G1 is recognized from the forward image G acquired by the on-board camera 2 has been described, but if another oncoming vehicle G2 is recognized during this processing as shown in Fig. 7, the above-described processing is performed in parallel to identify a light-blocking area S10 for the oncoming vehicle G2, and light distribution control is performed according to the multiple light-blocking areas identified in each processing. Also, if a glare suppression target other than an oncoming vehicle (for example, a vehicle ahead) is recognized in the forward image G, a light-blocking area for that target is identified, and light distribution control is performed including this light-blocking area.

[0028] As described above, according to the light distribution control device 1 for a vehicle headlamp of an embodiment of the present invention, light distribution control can be continued up to that point even when an oncoming vehicle moves out of the field of view of the forward image, so that unpleasant glare can be suppressed at all times for oncoming vehicles that are within the light irradiation range L of the headlamp device 3.

[0029] Furthermore, with the light distribution control device 1 for a vehicle headlamp according to the embodiment of the present invention, when an oncoming vehicle leaves the light irradiation range L of the headlamp device 3 and it is confirmed that the oncoming vehicle will pass the driver's vehicle, the light distribution control shading is immediately canceled, thereby minimizing the risk of shading the vicinity of the driver's vehicle. This allows the light to be quickly illuminated on a person or the like who appears from behind the oncoming vehicle, making the driver aware of the person.

[0030] 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.

[0031] 1: Light distribution control device, 2: In-vehicle camera, 3: Headlight device, 10: Control device, 11, 12: ECU, 13: In-vehicle network, 14: Central gateway, 100: CPU, 101: ROM, 102: RAM, 103: I / F, 104: Bus, B: Vehicle, G: Forward image, G1: Oncoming vehicle, S1, S2, S3, S30: Light blocking area, L: Light irradiation area

Claims

1. A light distribution control device for a vehicle headlamp that sets a light shielding range for an oncoming vehicle based on a front image of the host vehicle acquired by an in-vehicle camera. When the oncoming vehicle is recognized in the front image, the light distribution control is performed by specifying the light shielding range according to the recognized oncoming vehicle. When the oncoming vehicle is not recognized in the front image, if the light distribution control is in progress, the position of the oncoming vehicle is predicted, and the light distribution control is continued until the passing of the host vehicle and the oncoming vehicle is confirmed. A light distribution control device for a vehicle headlamp.

2. The light distribution control device for a vehicle headlamp according to claim 1, wherein the passing is confirmed by the predicted position of the oncoming vehicle being outside the light irradiation range of the vehicle headlamp.

3. In the light distribution control when the oncoming vehicle is not recognized in the front image, the light shielding range is specified according to the predicted position of the oncoming vehicle. The light distribution control device for a vehicle headlamp according to claim 1.

4. In the light distribution control when the oncoming vehicle is not recognized in the front image, the light shielding range is specified by expanding the light shielding range specified immediately before. The light distribution control device for a vehicle headlamp according to claim 1.

5. The position of the oncoming vehicle is predicted based on the relative speed between the recognized oncoming vehicle and the host vehicle during the light distribution control. The light distribution control device for a vehicle headlamp according to claim 1.

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