Headlamp control device, headlamp control method and headlamp control program

Abstract

To provide a headlamp control device capable of appropriately setting a dimming region.SOLUTION: A headlamp control device comprises: a headlamp which emits light toward the front side of an own vehicle; an external sensor that detects the external environment of the own vehicle; a pedestrian recognition unit that recognizes a pedestrian region 51 including a pedestrian 5 positioned in front of the own vehicle on the basis of the detection results of the external sensor; a headlamp control unit that reduces the brightness of light irradiated to a dimming region 52 including an upper end of the pedestrian region 51; and a change determination unit that determines whether or not a height H1 of the pedestrian region 51 has changed on the basis of the detection results of the external sensor. When the height H1 of the pedestrian region 51 has changed, the headlamp control unit changes a ratio at which the dimming region 52 occupies the pedestrian region 51.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a headlamp control device, a headlamp control method, and a headlamp control program. [Background technology]

[0002] Conventionally, JP 2013-184614 A is known as a technical document related to headlights. JP 2013-184614 A discloses a technology for reducing the glare felt by a pedestrian by reducing the amount of illumination in a dimming area including approximately the upper body of the pedestrian. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2013-184614 A Summary of the Invention [Problem to be solved by the invention]

[0004] When the detection accuracy of the upper body of a pedestrian is insufficient, it may be difficult to set the dimming region. Therefore, for example, a predetermined percentage of the pedestrian's height may be set as the dimming region. However, even when a part of the pedestrian is blocked by an obstruction or the like, if a predetermined percentage of the pedestrian's height is set as the dimming region, the dimming region may be set inappropriately.

[0005] An object of the present disclosure is to provide a headlamp control device, a headlamp control method, and a headlamp control program that are capable of appropriately setting a dimming region. [Means for solving the problem]

[0006] The headlight control device disclosed herein includes a headlight that emits light forward of the vehicle, an external sensor that detects the external environment of the vehicle, a pedestrian recognition unit that recognizes a pedestrian area including pedestrians located in front of the vehicle based on the detection result of the external sensor, a headlight control unit that reduces the brightness of light emitted to a dimming area of ​​the pedestrian area including the upper end of the pedestrian area, and a change determination unit that determines whether the height of the pedestrian area has changed based on the detection result of the external sensor, and when the height of the pedestrian area has changed, the headlight control unit changes the proportion of the pedestrian area that is occupied by the dimming area.

[0007] The headlight control method disclosed herein is a headlight control method for a headlight control device that controls a headlight that emits light ahead of the host vehicle, and includes an illumination step of emitting light from the headlight, a recognition step of recognizing a pedestrian area including a pedestrian located in front of the host vehicle based on detection results of an external sensor of the host vehicle, a dimming step of reducing the brightness of light illuminated to a dimming area of ​​the pedestrian area including an upper end of the pedestrian area, a determination step of determining whether the height of the pedestrian area has changed based on the detection results of the external sensor, and a dimming area adjustment step of changing the proportion of the pedestrian area that the dimming area occupies when the height of the pedestrian area has changed.

[0008] The headlight control program disclosed herein is a headlight control program that operates an ECU of a headlight that emits light ahead of the vehicle, and operates ECU 10 as a pedestrian recognition unit that recognizes a pedestrian area including pedestrians located in front of the vehicle based on detection results from an external sensor of the vehicle, a headlight control unit that reduces the brightness of light emitted to a dimming area of ​​the pedestrian area including the upper end of the pedestrian area, and a change determination unit that determines whether the height of the pedestrian area has changed based on the detection results from the external sensor, and when the height of the pedestrian area changes, the headlight control unit changes the proportion of the pedestrian area that is occupied by the dimming area. Effect of the Invention

[0009] According to the present disclosure, it is possible to provide a headlamp control device, a headlamp control method, and a headlamp control program that are capable of appropriately setting a dimming region. [Brief description of the drawings]

[0010] [Figure 1] FIG. 2 is a block diagram of a functional configuration of a headlamp control device according to an embodiment. [Diagram 2] FIG. 13 is a schematic diagram showing an example of a pedestrian detection result. [Diagram 3] FIG. 13 is a schematic diagram showing an example of a pedestrian detection result. [Figure 4] FIG. 13 is a schematic diagram showing an example of a pedestrian detection result. [Diagram 5] FIG. 13 is a schematic diagram showing an example of a pedestrian detection result. [Figure 6] 2 is a flowchart showing steps of a headlamp control method using the headlamp control device shown in FIG. 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0012] [Headlamp control device] Fig. 1 is a block diagram of a functional configuration of a headlamp control device according to an embodiment. The headlamp control device 1 shown in Fig. 1 is used in, for example, an autonomous driving vehicle or a driving assistance vehicle. As shown in Fig. 1, the headlamp control device 1 includes an external sensor 2, an internal sensor 3, a headlamp 4, and an ECU [Electronic Control Unit] 10.

[0013] The external sensor 2 is a detection device that detects the external environment of the host vehicle (the situation around the host vehicle). The external sensor 2 has, for example, a camera and a radar sensor. The camera is an imaging device that captures the external situation of the host vehicle. The camera is provided, for example, on the back side of the windshield of the host vehicle and captures the area in front of the host vehicle. The camera captures pedestrians and the like located in front of the host vehicle. The camera transmits the captured image relating to the external situation of the host vehicle to the ECU 10. The radar sensor is a detection device that detects objects around the host vehicle using radio waves (for example, millimeter waves) or light. The radar sensor is, for example, a millimeter wave radar or a LiDAR (Light Detection and Ranging), etc. The radar sensor detects the distance and relative position of a pedestrian located in front of the host vehicle. The radar sensor transmits information on the detected object to the ECU 10.

[0014] The internal sensor 3 is a detection device that detects the traveling state of the host vehicle. The internal sensor 3 has, for example, a vehicle speed sensor and a yaw rate sensor. The vehicle speed sensor is a detector that detects the speed of the host vehicle. The vehicle speed sensor transmits vehicle speed information to the ECU 10. The yaw rate sensor is a detector that detects the yaw rate (rotational angular velocity) around the vertical axis of the center of gravity of the host vehicle. The yaw rate sensor is, for example, a gyro sensor. The yaw rate sensor transmits yaw rate information of the host vehicle to the ECU 10.

[0015] The headlamp 4 is attached to the front of the vehicle. The headlamp 4 irradiates light ahead of the vehicle. The headlamp 4 has a plurality of light sources, a DMD [Digital Micromirror Device], a lens, and the like. The DMD reflects the light emitted from the plurality of light sources. The lens collects the light reflected by the DMD. The light collected by the lens is emitted ahead of the vehicle.

[0016] The light source is, for example, a high-intensity discharge (HID), a halogen lamp, or a light-emitting diode (LED). The DMD has a number of micromirrors arranged in a matrix. The direction of the optical axis of each micromirror is variable. Each micromirror can swing up and down and left and right. The direction of the optical axis of each micromirror is controlled by a control signal sent from the ECU 10.

[0017] The ECU 10 is an electronic control unit having a central processing unit (CPU) and a storage unit such as a read only memory (ROM) or a random access memory (RAM). In the ECU 10, for example, various functions are realized by the CPU executing a program stored in the storage unit. The ECU 10 is provided in, for example, a vehicle.

[0018] The ECU 10 includes, as its functional components, a pedestrian recognition unit 11, a change determination unit 12, and a headlamp control unit 13.

[0019] The pedestrian recognition unit 11 recognizes a pedestrian located in front of the vehicle based on the detection result of the external sensor 2. The pedestrian recognition unit 11 recognizes a pedestrian by pattern matching using a previously prepared image pattern of a pedestrian, or the like.

[0020] 2 is a schematic diagram showing an example of a pedestrian detection result. As shown in FIG. 2, when a pedestrian 5 is detected by the external sensor 2, the pedestrian recognition unit 11 recognizes a pedestrian area 51 including the pedestrian 5 as the pedestrian 5. The pedestrian area 51 is an area surrounding the pedestrian 5. The pedestrian area 51 has, for example, a rectangular shape. There are cases where a part of the pedestrian 5 (for example, the lower body) is obstructed by an obstruction 6. The pedestrian recognition unit 11 recognizes only a part of the pedestrian 5 that is exposed from the obstruction 6 as the pedestrian 5.

[0021] Fig. 3 is a schematic diagram showing an example of a pedestrian detection result. The part of the pedestrian 5 shown in Fig. 3 that is blocked by the obstruction 6 is larger than the part of the pedestrian 5 shown in Fig. 2 that is blocked by the obstruction 6, so the height H1 of the pedestrian area 51 (second pedestrian area) shown in Fig. 3 is smaller than the height H1 of the pedestrian area 51 (first pedestrian area) shown in Fig. 2. In this way, the height H1 of the pedestrian area 51 may decrease due to a change in the state of the obstruction 6, etc. Note that the height H1 of the pedestrian area 51 is, for example, the length of the pedestrian area 51 in the vertical direction.

[0022] Fig. 4 is a schematic diagram showing an example of a pedestrian detection result. The part of the pedestrian 5 shown in Fig. 4 that is blocked by the obstruction 6 is smaller than the part of the pedestrian 5 shown in Fig. 2 that is blocked by the obstruction 6, so the height H1 of the pedestrian area 51 (third pedestrian area) shown in Fig. 4 is larger than the height H1 of the pedestrian area 51 (first pedestrian area) shown in Fig. 2. In this way, the height H1 of the pedestrian area 51 may increase due to a change in the state of the obstruction 6, etc.

[0023] In this embodiment, the height H1 of the pedestrian area 51 is a value calculated based on the positional relationship, such as the distance, between the host vehicle and the pedestrian 5. In other words, the height H1 of the pedestrian area 51 is a value that corresponds to the actual height of the pedestrian 5, regardless of the positional relationship between the host vehicle and the pedestrian 5. The height H1 of the pedestrian area 51 does not substantially change according to the change in the positional relationship between the host vehicle and the pedestrian 5.

[0024] The change determination unit 12 determines whether or not the height H1 of the pedestrian area 51 has changed based on the detection result of the external sensor 2. The change determination unit 12 determines whether or not there is a difference between the height H1 of the pedestrian area 51 at the first time and the height H1 of the pedestrian area 51 at the second time. The change determination unit 12 determines whether or not the height H1 of the pedestrian area 51 has decreased, or whether or not the height H1 of the pedestrian area 51 has increased. The change determination unit 12 determines whether or not the height H1 of the pedestrian area 51 at the second time is smaller than the height H1 of the pedestrian area 51 at the first time, or whether or not the height H1 of the pedestrian area 51 at the second time is larger than the height H1 of the pedestrian area 51 at the first time.

[0025] The headlamp control unit 13 sets the dimming region 52 within the pedestrian region 51. The dimming region 52 is a region of the pedestrian region 51 that includes the upper end of the pedestrian region 51. That is, the dimming region 52 is a region of the pedestrian region 51 that extends from the upper end of the pedestrian region 51 to a position between the upper end and the lower end of the pedestrian region 51. The dimming region 52 is a region of the pedestrian region 51 that has a height that is a preset ratio of the height H1 of the pedestrian region 51 to the upper end of the pedestrian region 51. The dimming region 52 has, for example, a rectangular shape. The headlamp control unit 13 sets the ratio of the pedestrian region 51 that the dimming region 52 occupies in the pedestrian region 51 (in this embodiment, the value obtained by dividing the height H2 of the dimming region 52 by the height H2 of the pedestrian region 51). The height H2 of the dimming region 52 is, for example, the length of the dimming region 52 in the vertical direction.

[0026] The headlamp control unit 13 controls the operation of the headlamp 4. The headlamp control unit 13 executes dimming control to reduce the brightness of the light irradiated to the dimming region 52. The headlamp control unit 13 changes the optical axis of a micromirror that corresponds to the dimming region 52, among the multiple micromirrors of the headlamp 4. As a result, the light reflected by the micromirror is emitted toward a region other than the dimming region 52. Therefore, the illuminance of the dimming region 52 decreases.

[0027] When the height H1 of the pedestrian area 51 changes, the headlight control unit 13 changes the ratio (hereinafter referred to as "ratio (H2 / H1)") of the dimming area 52 to the pedestrian area 51. When the height H1 of the pedestrian area 51 decreases, the headlight control unit 13 increases the ratio (H2 / H1). For example, when the height H1 of the pedestrian area 51 at the second time (e.g., see FIG. 3) is smaller than the height H1 of the pedestrian area 51 at the first time (e.g., see FIG. 2), the headlight control unit 13 makes the ratio (H2 / H1) at the second time larger than the ratio (H2 / H1) at the first time.

[0028] The headlight control unit 13 decreases the ratio (H2 / H1) when the height H1 of the pedestrian area 51 increases. For example, when the height H1 of the pedestrian area 51 at the second time (e.g., see FIG. 4) is greater than the height H1 of the pedestrian area 51 at the first time (e.g., see FIG. 2), the headlight control unit 13 makes the ratio (H2 / H1) at the second time smaller than the ratio (H2 / H1) at the first time.

[0029] The headlight control unit 13 reduces the ratio (H2 / H1) by setting a predetermined threshold as the lower limit of the ratio (H2 / H1). That is, even if the height H1 of the pedestrian area 51 increases, the headlight control unit 13 does not reduce the ratio (H2 / H1) to a value smaller than the predetermined threshold. The predetermined threshold is, for example, 25%. FIG. 5 is a schematic diagram showing an example of a pedestrian detection result. As shown in FIG. 5, there are cases where the pedestrian 5 is not blocked by the obstruction 6 (see FIG. 2, etc.) (the entire body of the pedestrian 5 is recognized). In such a case, if the ratio (H2 / H1) is reduced too much, the head of the pedestrian 5 may not be located inside the dimming area 52. Therefore, as described above, the headlight control unit 13 does not reduce the ratio (H2 / H1) to a value smaller than the predetermined threshold.

[0030] The headlight control unit 13 does not change the ratio (H2 / H1) when there is no change in the height H1 of the pedestrian area 51. In other words, the headlight control unit 13 maintains the ratio (H2 / H1) when the height H1 of the pedestrian area 51 is maintained.

[0031] [ECU processing of headlamp control device, headlamp control method, and headlamp control program] Next, an example of processing by the ECU 10 of the headlamp control device 1 will be described. Fig. 6 is a flowchart showing each step of processing by the ECU 10 (a headlamp control method using the headlamp control device 1). As shown in Fig. 6, in step S1 (illumination step), the ECU 10 causes the headlamp 4 to emit light ahead of the host vehicle. For example, when the brightness outside the host vehicle becomes smaller than a predetermined threshold, the ECU 10 operates the headlamp 4. In step S2 (recognition step), the ECU 10 recognizes a pedestrian area 51 including a pedestrian 5 located ahead of the host vehicle based on the detection result of the external sensor 2.

[0032] In step S3 (dimming region setting step), the ECU 10 sets the dimming region 52 within the pedestrian region 51. In step S4 (dimming step), the ECU 10 reduces the brightness of the light irradiated to the dimming region 52 in the pedestrian region 51. In step S5 (determination step), the ECU 10 determines whether the height H1 of the pedestrian region 51 has changed based on the detection result of the external sensor 2. If the height H1 of the pedestrian region 51 has changed, the ECU 10 changes the ratio (H2 / H1) of the dimming region 52 in the pedestrian region 51 in step S6 (dimming region adjustment step). If the height of the pedestrian region 51 has decreased, the ECU 10 increases the ratio (H2 / H1). If the height of the pedestrian region 51 has increased, the ECU 10 decreases the ratio (H2 / H1).

[0033] The headlamp control program causes the ECU 10 to function (operate) as the pedestrian recognition unit 11, the change determination unit 12, and the headlamp control unit 13. The headlamp control program is provided by a non-transitory recording medium such as a ROM or a semiconductor memory. The headlamp control program may be provided via communication such as a network.

[0034] As described above, in the headlamp control device 1 of this embodiment, when the height H1 of the pedestrian area 51 changes, the headlamp control unit 13 changes the ratio (H2 / H1) of the dimming area 52 to the pedestrian area 51. As a result, when the area including the upper body of the pedestrian 5 is not recognized sufficiently due to the performance of the external sensor 2, for example, even if part of the pedestrian 5 is blocked by an obstruction 6 or the like, the dimming area 52 including the head of the pedestrian 5 can be appropriately set. Therefore, the headlamp control device 1 can appropriately set the dimming area 52.

[0035] When the height H1 of the pedestrian region 51 is reduced, the ECU 10 increases the ratio (H2 / H1). When the height H1 of the pedestrian region 51 is reduced, there is a possibility that a part of the pedestrian 5 is blocked by an obstruction 6, or the range of the obstruction 6 is increased, in which case the proportion of the head of the pedestrian 5 in the pedestrian 5 tends to increase. Therefore, when the height H1 of the pedestrian region 51 is reduced, by increasing the ratio (H2 / H1), the region including the head of the pedestrian 5 can be appropriately set as the dimming region 52.

[0036] When the height H1 of the pedestrian area 51 increases, the ECU 10 decreases the ratio (H2 / H1). When the height H1 of the pedestrian area 51 increases, the range of the obstruction 6 blocking the pedestrian 5 may have decreased, or the obstruction 6 may have disappeared, in which case the proportion of the head of the pedestrian 5 in the pedestrian 5 tends to decrease. Therefore, when the height H1 of the pedestrian area 51 increases, the ratio (H2 / H1) is decreased, so that the area including the head of the pedestrian 5 can be appropriately set as the dimming area 52.

[0037] The ECU 10 reduces the ratio (H2 / H1) with a predetermined threshold set as the lower limit of the ratio (H2 / H1). This prevents the dimming region 52 from being excessively reduced when, for example, the entire body of the pedestrian 5 is recognized.

[0038] According to the headlamp control method and headlamp control program of the present embodiment, similarly to the headlamp control device 1, the dimming region 52 can be appropriately set.

[0039] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above embodiments.

[0040] Although the direction of the optical axis of each micromirror of the headlight 4 is variable, the direction of the optical axis of each micromirror of the headlight 4 may be fixed. In this case, the reflectance of each micromirror of the headlight 4 may be variable. In other words, the brightness of the light irradiated to the dimming region 52 may be controlled by adjusting the reflectance of the micromirror of the headlight 4.

[0041] Although the external sensor 2 includes a radar sensor, the external sensor 2 does not have to include a radar sensor.

[0042] The ECU 10 may execute the dimming control only when the vehicle speed detected by the internal sensor 3 is within a predetermined range. For example, the ECU 10 may not execute the dimming control when the vehicle speed detected by the internal sensor 3 is greater than a predetermined threshold (e.g., 100 km / h).

[0043] The headlamp control device 1 does not necessarily have to include the internal sensor 3 .

[0044] The ECU 10 does not have to increase the ratio (H2 / H1) even if the height H1 of the pedestrian area 51 decreases. The ECU 10 does not have to decrease the ratio (H2 / H1) even if the height H1 of the pedestrian area 51 increases. The ECU 10 only has to change the ratio (H2 / H1) when the height H1 of the pedestrian area 51 changes. [Explanation of symbols]

[0045] 1...headlight control device, 2...external sensor, 4...headlight, 5...pedestrian, 11...pedestrian recognition unit, 12...change determination unit, 13...headlight control unit, 51...pedestrian area, 52...dimming area.

Claims

1. A headlamp that emits light forward of the vehicle; An external sensor for detecting an external environment of the host vehicle; a pedestrian recognition unit that recognizes a pedestrian area including a pedestrian located in front of the vehicle based on a detection result of the external sensor; a headlamp control unit that reduces the brightness of the light irradiated to a dimming region including an upper end of the pedestrian area in the pedestrian area; a change determination unit that determines whether or not a height of the pedestrian area has changed based on a detection result of the external sensor, The headlight control device is configured to change a proportion of the pedestrian area that is occupied by the dimming area when a height of the pedestrian area changes.

2. The headlamp control device according to claim 1 , wherein the headlamp control unit increases the ratio when a height of the pedestrian area decreases.

3. The headlamp control device according to claim 1 , wherein the headlamp control unit decreases the ratio when a height of the pedestrian area increases.

4. The headlamp control device according to claim 3 , wherein the headlamp control unit reduces the ratio by setting a predetermined threshold value as a lower limit value of the ratio.

5. A headlamp control method for a headlamp control device that controls a headlamp that irradiates light forward of a vehicle, comprising: an illumination step of illuminating the light by the headlight; a recognition step of recognizing a pedestrian area including a pedestrian located in front of the host vehicle based on a detection result of an external sensor of the host vehicle; a dimming step of reducing brightness of the light irradiated to a dimming region including an upper end of the pedestrian area in the pedestrian area; a determination step of determining whether or not a height of the pedestrian area has changed based on a detection result of the external sensor; and a dimming area adjusting step of changing a proportion of the pedestrian area that is occupied by the dimming area when a height of the pedestrian area changes.

6. A headlamp control program for operating an ECU of a headlamp that irradiates light forward of a vehicle, comprising: The ECU is operated as a pedestrian recognition unit that recognizes a pedestrian area including a pedestrian located in front of the vehicle based on a detection result of an external sensor of the vehicle, a headlight control unit that reduces the brightness of the light irradiated to a dimming area including an upper end of the pedestrian area, and a change determination unit that determines whether or not a height of the pedestrian area has changed based on the detection result of the external sensor, The headlamp control unit changes a proportion of the pedestrian area that is occupied by the dimming area when a height of the pedestrian area changes.

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