JP7602402B2 - Light distribution control device - Google Patents

Description

This disclosure relates to a light distribution control device that controls the light distribution of a headlamp.

Some vehicles perform headlamp light distribution control when being overtaken by another vehicle. For example, Patent Document 1 discloses a technology that uses radar to calculate the relative movement vector of the other vehicle relative to the vehicle itself, calculates the time until the other vehicle enters the headlamp's illumination range based on this relative movement vector, and performs light distribution control when the other vehicle enters the illumination range.

JP 2013-244892 A

As such, it is desirable for a light distribution control device to control the light distribution of headlamps, and it is expected that the light distribution control of headlamps will be performed effectively.

It is desirable to provide a light distribution control device that can effectively control the light distribution of headlamps.

A first light distribution control device according to an embodiment of the present disclosure includes a first detection unit, a second detection unit, and a light distribution control unit. The first detection unit is configured to detect a second vehicle in a predetermined area on the rear side of the first vehicle based on a detection result of a radar device provided on the first vehicle. The second detection unit is configured to detect a second vehicle behind the predetermined area based on a detection result of the radar device. The light distribution control unit is configured to determine a change timing for changing a light distribution state of a headlamp provided on the first vehicle based on a first timing at which the first detection unit detects the second vehicle. The light distribution control unit determines the change timing based on an elapsed time from a second timing at which the second detection unit detects the second vehicle to the first timing.

A second light distribution control device according to an embodiment of the present disclosure includes one or more processors and one or more memories. The one or more memories are communicatively connected to the one or more processors. The one or more processors perform a first detection to detect a second vehicle in a predetermined area on the rear side of the first vehicle based on a detection result of a radar device provided on the first vehicle, perform a second detection to detect the second vehicle behind the predetermined area based on the detection result of the radar device, and determine a change timing to change a light distribution state of a headlamp provided on the first vehicle based on an elapsed time from a second timing to the first timing when the second vehicle is detected by the second detection, using a first timing when the second vehicle is detected by the first detection as a reference.

The first and second light distribution control devices according to an embodiment of the present disclosure can effectively control the light distribution of the headlamp.

1 is a block diagram illustrating an example configuration of an in-vehicle system according to an embodiment of the present disclosure. 2 is an explanatory diagram illustrating a configuration example of a vehicle equipped with the in-vehicle system shown in FIG. 1 . 2 is an explanatory diagram illustrating detection target areas of a rear side vehicle detection unit and a rear vehicle detection unit illustrated in FIG. 1 ; FIG. 2 is an explanatory diagram illustrating an example of a light distribution state of the headlamp illustrated in FIG. 1 . 4 is an explanatory diagram illustrating another example of the light distribution state of the headlamp illustrated in FIG. 1 . FIG. 2 is a timing chart illustrating an example of an operation of the light distribution control device illustrated in FIG. 1 . 1. FIG. 4 is a timing diagram illustrating another example of the operation of the light distribution control device illustrated in FIG. 1. FIG. 4 is a timing diagram illustrating another example of the operation of the light distribution control device illustrated in FIG. 1. FIG. 4 is a timing diagram illustrating another example of the operation of the light distribution control device illustrated in FIG. 4 is a flowchart illustrating an example of an operation of a light distribution control unit illustrated in FIG. 1 . FIG. 11 is an explanatory diagram illustrating an example of a light distribution state of a headlamp according to a reference example.

The following describes in detail the embodiments of the present disclosure with reference to the drawings.

<Embodiment>
[Configuration example]
1 shows an example of the configuration of an in-vehicle system 1 equipped with a light distribution control device according to an embodiment. The in-vehicle system 1 includes a stereo camera 11, a radar device 12, a headlamp 13, and a processing unit 20. The in-vehicle system 1 is mounted on a vehicle 10 such as an automobile.

The stereo camera 11 is configured to capture an image of the area ahead of the vehicle 10, thereby generating a pair of images (a left image PL and a right image PR) that have a mutual parallax. The stereo camera 11 has a left camera 11L and a right camera 11R. Each of the left camera 11L and the right camera 11R includes a lens and an image sensor.

Figure 2 shows an example of the arrangement of the stereo camera 11 in the vehicle 10. In this example, the left camera 11L and the right camera 11R are arranged inside the vehicle 10 near the upper part of the windshield 9 of the vehicle 10, spaced a predetermined distance apart in the width direction of the vehicle 10. The left camera 11L generates a left image PL, and the right camera 11R generates a right image PR. The left image PL and the right image PR constitute a stereo image PIC. The stereo camera 11 performs an imaging operation at a predetermined frame rate (e.g., 60 [fps]) to generate a series of stereo images PIC, and supplies the generated stereo images PIC to the processing unit 20.

The radar device 12 (Fig. 1) is configured to detect objects such as vehicles around the vehicle 10 by irradiating the surroundings of the vehicle 10 with radio waves, such as millimeter waves, and detecting the radio waves reflected from the objects. The radar device 12 then supplies the processing unit 20 with position data POS that indicates the relative position of the object with respect to the vehicle 10.

The headlamp 13 has a light source such as a light-emitting diode and is configured to irradiate light in front of the vehicle 10. The headlamp 13 has a left headlamp 13L and a right headlamp 13R. As shown in FIG. 2, the left headlamp 13L is provided at the left front of the vehicle 10, and the right headlamp 13R is provided at the right front of the vehicle 10. The headlamp 13 is configured to be able to change the direction of light irradiation. Specifically, the headlamp 13 can irradiate light using so-called high beam or low beam based on, for example, the driver's operation or an instruction from an ECU (Electronic Control Unit) not shown. In high beam, the headlamp 13 irradiates light far in front of the vehicle 10. In low beam, the headlamp 13 irradiates light in a portion closer to the vehicle 10 in front of the vehicle 10 by lowering the light irradiation direction compared to high beam. This headlamp 13 is a headlamp with variable light distribution (ADB: Adaptive Driving Beam). Specifically, as described below, when the left headlamp 13L and the right headlamp 13R are emitting light using high beams, the left headlamp 13L and the right headlamp 13R can partially control the emission of light so as not to emit light at another vehicle 90 when the vehicle 10 is being overtaken by the other vehicle. This allows the driver of the vehicle 90 to feel less glare in the vehicle 10.

The processing unit 20 is configured to perform various processes based on the stereo image PIC supplied from the stereo camera 11 and the position data POS supplied from the radar device 12. The processing unit 20 is configured, for example, with a CPU (Central Processing Unit) that executes a program, a RAM (Random Access Memory) that temporarily stores processing data, and a ROM (Read Only Memory) that stores programs. The processing unit 20 has an exterior environment detection unit 21 and a light distribution control unit 24.

The vehicle exterior environment detection unit 21 is configured to detect the environment around the vehicle 10 based on the stereo image PIC supplied from the stereo camera 11 and the position data POS supplied from the radar device 12. Based on the information about the environment detected by the vehicle exterior environment detection unit 21, the vehicle 10 can, for example, perform driving control of the vehicle 10 or display information about the detected environment on a console monitor. The vehicle exterior environment detection unit 21 has a rear side vehicle detection unit 22 and a rear vehicle detection unit 23.

The rear side vehicle detection unit 22 is configured to perform rear side detection DA, which detects whether a vehicle is traveling in the detection target area RA on the left and right rear sides of the vehicle 10, based on the position data POS supplied from the radar device 12.

The rear vehicle detection unit 23 is configured to perform rear detection DB to detect whether a vehicle is traveling in the detection target area RB on the left and right rear of the vehicle 10 based on the position data POS supplied from the radar device 12.

Figure 3 shows an example of a detection target area RA for rear side detection DA and a detection target area RB for rear detection DB. In this example, the vehicle 10 is traveling in the center lane of a three-lane roadway 100.

The detection target area RA of the rear side detection DA includes two detection target areas RAL, RAR. The detection target area RAL is located behind the left side of the vehicle 10. The end of the detection target area RAL in the vehicle length direction of the vehicle 10 is located on the left side of the vehicle 10. The detection target area RAR is located behind the right side of the vehicle 10. The end of the detection target area RAR in the driving direction of the vehicle 10 is located on the left side of the vehicle 10. In this example, the width of the detection target areas RAL, RAR in the vehicle width direction of the vehicle 10 (the horizontal width in FIG. 3) is, for example, about the same as the width of the driving lane, and the length of the detection target areas RAL, RAR in the vehicle length direction of the vehicle 10 (the vertical length in FIG. 3) is, for example, about 10 meters. In this way, the detection target areas RAL, RAR are fixed, predetermined areas. The rear vehicle detection unit 22 detects whether a vehicle is traveling in the detection target areas RAL, RAR based on the position data POS supplied from the radar device 12.

Based on the results of this rear side detection DA, the vehicle 10 can perform so-called BSD (Blind Spot Detection) processing. That is, the detection target areas RAL, RAR are areas that correspond to so-called blind spots of the vehicle 10. Based on the results of this rear side detection DA, the vehicle 10 notifies the driver of the vehicle 10 that the vehicle is traveling in the detection target area RA. This allows the vehicle 10 to avoid colliding with a vehicle traveling in the blind spot of the vehicle 10.

The detection target area RB of the rear detection DB includes two detection target areas RBL, RBR. The detection target area RBL is located rearward of the detection target area RAL on the left side of the vehicle 10. In this example, a part of the detection target area RBL overlaps with a part of the detection target area RAL. The detection target area RBR is located rearward of the detection target area RAR on the right side of the vehicle 10. In this example, a part of the detection target area RBR overlaps with a part of the detection target area RAR. In this example, the width of the detection target areas RBL, RBR in the vehicle width direction of the vehicle 10 (the horizontal width in FIG. 3) is approximately the same as the width of the driving lane, for example. The length of the detection target areas RBL, RBR in the vehicle length direction of the vehicle 10 (the vertical length in FIG. 3) is variable. Specifically, for example, when the vehicle 90 is traveling behind the vehicle 10, the rear vehicle detection unit 23 calculates the time (arrival time) that the position of the vehicle 90 in the traveling direction of the vehicle 10 will reach the position of the vehicle 10. Then, when the arrival time is a predetermined time (for example, 4 seconds), the rear vehicle detection unit 23 determines that the vehicle 90 has entered the detection target area RB. The positions of the final ends of the detection target areas RBL, RBR in the traveling direction of the vehicle 10 are thus positions of the vehicle 90 at which the vehicle 90 will reach the position of the vehicle 10 after a predetermined time (for example, 4 seconds). Therefore, for example, the greater the speed difference ΔSP (=SP90-SP10) between the speed SP90 of the vehicle 90 and the speed SP10 of the vehicle 10, the longer the length of the detection target areas RBL, RBR, and the smaller the speed difference ΔSP, the shorter the length of the detection target areas RBL, RBR. In this way, the detection target areas RBL, RBR are variable areas. The rear vehicle detection unit 23 detects whether a vehicle is traveling in the detection target areas RBL, RBR based on the position data POS supplied from the radar device 12.

Based on the results of this rear detection DB, the vehicle 10 can perform so-called LCA (Lane Change Assist) processing. Based on the results of this rear detection DB, the vehicle 10 notifies the driver of the vehicle 10 that the vehicle is traveling in the detection target area RB. This allows the vehicle 10 to avoid colliding with a vehicle traveling behind the vehicle 10, for example, when the driver of the vehicle 10 is trying to change the driving lane.

The light distribution control unit 24 (FIG. 1) is configured to control the light distribution of the headlamp 13 based on the results of the rear side detection DA and rear detection DB. The rear side vehicle detection unit 22, the rear vehicle detection unit 23, and the light distribution control unit 24 constitute a light distribution control device 25.

Figures 4 and 5 show an example of the light distribution state of the headlamp 13, with Figure 4 showing an example of light distribution state SA and Figure 5 showing light distribution state SB. In this example, vehicle 10 is traveling in the left lane of a two-lane roadway 101. In Figure 4, there are no other vehicles traveling around vehicle 10, and vehicle 90 is traveling behind vehicle 10, away from vehicle 10, in the same direction as vehicle 10. In Figure 5, vehicle 90 is overtaking vehicle 10. In Figures 4 and 5, the shaded areas indicate the illumination range of the headlamp 13. Area RC indicates the angle of view of the stereo camera 11.

When the headlamps 13 are emitting light using high beams and the vehicle 90 is overtaking the vehicle 10, the light distribution control unit 24 performs light distribution control to change the light distribution state S of the headlamps 13 from light distribution state SA (FIG. 4) to light distribution state SB (FIG. 5). In light distribution state SB, the light emission is partially controlled so that the high beams are not emitted to the vehicle 90. The light distribution control unit 24 determines the timing to change the light distribution state S of the headlamps 13 from light distribution state SA to light distribution state SB based on the detection timing of the rear side detection DA, and controls the light distribution state S of the headlamps 13 to be changed at the determined timing. This allows the driver of the vehicle 90 to feel less glare in the vehicle 10.

The light distribution control unit 24 also determines the length of time (time T) for which the light distribution state S is maintained at light distribution state SB based on the length of time (time Ton) for which the vehicle 90 continues to be detected in the rear side detection DA, thereby determining the timing for returning the light distribution state S of the headlamp 13 from light distribution state SB to light distribution state SA. In this example, the light distribution control unit 24 measures time by counting the number of frames of the stereo image PIC. The light distribution control unit 24 starts a counting operation at the timing when the light distribution state S is changed from light distribution state SA to light distribution state SB, and returns the light distribution state S of the headlamp 13 from light distribution state SB to light distribution state SA at the determined timing based on the count value.

Here, the rear side vehicle detection unit 22 corresponds to a specific example of a "first detection unit" in this disclosure. The rear vehicle detection unit 23 corresponds to a specific example of a "second detection unit" in this disclosure. The light distribution control unit 24 corresponds to a specific example of a "light distribution control unit" in this disclosure. The vehicle 10 corresponds to a specific example of a "first vehicle" in this disclosure. The vehicle 90 corresponds to a specific example of a "second vehicle" in this disclosure. The radar device 12 corresponds to a specific example of a "radar device" in this disclosure. The headlamp 13 corresponds to a specific example of a "headlamp" in this disclosure.

[Actions and Functions]
Next, the operation and function of the in-vehicle system 1 of this embodiment will be described.

(Overall operation overview)
1, the stereo camera 11 captures an image of the area in front of the vehicle 10 to generate a stereo image PIC, and supplies the generated stereo image PIC to the processing unit 20. The radar device 12 detects an object around the vehicle 10 by irradiating an area around the vehicle 10 with radio waves and detecting radio waves reflected from the object. The radar device 12 then supplies the processing unit 20 with position data POS indicating a relative position of the object as viewed from the vehicle itself. The external environment detection unit 21 of the processing unit 20 detects the environment around the vehicle 10 based on the stereo image PIC supplied from the stereo camera 11 and the position data POS supplied from the radar device 12. The rear side vehicle detection unit 22 performs rear side detection DA to detect whether a vehicle is traveling in a detection target area RA on the left and right rear sides of the vehicle 10 based on the position data POS supplied from the radar device 12. The rear vehicle detection unit 23 performs rear detection DB to detect whether a vehicle is traveling in a detection target area RB on the left and right rear of the vehicle 10, based on the position data POS supplied from the radar device 12. The light distribution control unit 24 controls the light distribution of the headlamps 13 based on the results of the rear lateral detection DA and rear detection DB. The headlamps 13 irradiate light forward of the vehicle 10. When irradiating light using high beams, each of the left headlamp 13L and the right headlamp 13R changes the light distribution based on an instruction from the light distribution control unit 24.

(Detailed operation)
When the headlamps 13 are emitting light using high beams and the vehicle 90 is overtaking the vehicle, the light distribution control unit 24 changes the light distribution state S of the headlamps 13 from light distribution state SA (FIG. 4) to light distribution state SB (FIG. 5) in which the high beams are not emitted to the vehicle 90. The operation of the light distribution control device 25 will be described in detail below with some examples.

(Case C1)
6 shows an example of the operation of the light distribution control device 25 when the speed difference ΔSP (=SP90-SP10) between the speed SP90 of the vehicle 90 and the speed SP10 of the vehicle 10 is large, where (A) shows the result of the rear detection DB by the rear vehicle detection unit 23, (B) shows the result of the rear side detection DA by the rear side vehicle detection unit 22, (C) shows the light distribution state S of the headlamp 13, and (D) shows the counting operation in the light distribution control unit 24. In Fig. 6(A), "on" indicates that the rear vehicle detection unit 23 has detected the vehicle 90 in the detection target area RB. In Fig. 6(B), "on" indicates that the rear side vehicle detection unit 22 has detected the vehicle 90 in the detection target area RA.

Before timing t11, vehicle 90 is traveling behind vehicle 10. The light distribution control unit 24 sets the light distribution state S of the headlamp 13 to light distribution state SA (FIG. 4). Since the speed SP90 of vehicle 90 is faster than the speed SP10 of vehicle 10, the distance between vehicle 10 and vehicle 90 becomes shorter as time passes.

At timing t11, the rear vehicle detection unit 23 detects a vehicle 90 in the detection target area RB (detection target area RBR in this example) based on the position data POS supplied from the radar device 12 (FIG. 6(A)). Thereafter, the distance between the vehicle 10 and the vehicle 90 decreases as time passes. Then, the vehicle 90 approaches the detection target area RA (detection target area RAR in this example).

Then, at a timing t12, which is a time longer than a predetermined time T1 from the timing t11, the rear vehicle detection unit 22 detects a vehicle 90 in the detection target area RAR based on the position data POS supplied from the radar device 12 (FIG. 6(B)). Here, the predetermined time T1 can be, for example, a time equivalent to 30 frames.

In this way, when the time ΔT from when rear detection DB is turned on until rear side detection DA is turned on is longer than the predetermined time T1 (ΔT>T1), the light distribution control unit 24 changes the light distribution state S from light distribution state SA (FIG. 4) to light distribution state SB (FIG. 5) at timing t12 when rear side detection DA is turned on (FIG. 6(C)). In light distribution state SB (FIG. 5), the illumination range of the headlamp 13 is more limited than in light distribution state SA (FIG. 4). In this example, vehicle 90 is traveling behind the right side of vehicle 10, so the illumination range is limited so that the right side of the illumination range is missing.

Then, at this timing t12, the light distribution control unit 24 starts a counting operation by counting the number of frames of the stereo image PIC (FIG. 6(D)). As a result, the count value increases over time.

Then, at timing t13, the rear vehicle detection unit 23 detects that the vehicle 90 has disappeared from the detection target area RBR based on the position data POS supplied from the radar device 12 (FIG. 6(A)). That is, the vehicle 90 passes through the detection target area RBR and travels ahead of the detection target area RBR, so the rear vehicle detection unit 23 detects that the vehicle 90 has disappeared from the detection target area RBR.

Then, at timing t14, the rear side vehicle detection unit 22 detects that the vehicle 90 has disappeared from the detection target area RAR based on the position data POS supplied from the radar device 12 (FIG. 6B). That is, the vehicle 90 passes through the detection target area RAR and travels ahead of the detection target area RAR, so the rear side vehicle detection unit 22 detects that the vehicle 90 has disappeared from the detection target area RAR. The light distribution control unit 24 measures the length of the period (time Ton) during which the rear side detection DA is on from timing t12 to t14.

Vehicle 90 continues traveling toward the right front of vehicle 10. At this time, in light distribution state SB, the illumination range of headlamp 13 is limited so that the right side of the illumination range is missing, as shown in FIG. 5. This reduces the possibility that the driver of vehicle 90 will feel glare due to light reflected by, for example, the door mirror of vehicle 90. Vehicle 90 then continues traveling at speed SP90, which is faster than vehicle 10's speed SP10, and vehicle 90 moves away from vehicle 10.

Then, at timing t15, which is N times the time Ton (= Ton × N) after timing t12, the light distribution control unit 24 changes the light distribution state S from the light distribution state SB ( FIG. 5 ) back to the light distribution state SA ( FIG. 4 ) based on the count value in the counting operation ( FIG. 6 (C)). Here, "N" can be, for example, "5." That is, at this timing t15, the vehicle 90 is sufficiently far away from the vehicle 10, so the light distribution control unit 24 changes the light distribution state S back to the light distribution state SA from the light distribution state SB.

(Case C2)
7 and 8 show an example of the operation of the light distribution control device 25 when the speed difference ΔSP between the speed SP90 of the vehicle 90 and the speed SP10 of the vehicle 10 is medium. Before timings t21 and t31, the vehicle 90 is traveling behind the vehicle 10. Then, the vehicle 90 approaches the detection target region RBR.

At timings t21 and t31, the rear vehicle detection unit 23 detects the vehicle 90 in the detection target region RBR based on the position data POS supplied from the radar device 12 (FIGS. 7(A) and 8(A)). After that, the distance between the vehicle 10 and the vehicle 90 continues to decrease as time passes.

Then, at timings t22 and t32, which are longer than the predetermined time T2 and shorter than the predetermined time T1 after timings t21 and t31, the rear vehicle detection unit 22 detects a vehicle 90 in the detection target area RAR based on the position data POS supplied from the radar device 12 (FIGS. 7(B) and 8(B)). Here, the predetermined time T2 can be, for example, a time equivalent to 20 frames.

At timings t24 and t34, the rear vehicle detection unit 23 detects that the vehicle 90 has disappeared from the detection target area RBR based on the position data POS supplied from the radar device 12 (FIGS. 7(A) and 8(A)). Then, at timings t25 and t35, the rear side vehicle detection unit 22 detects that the vehicle 90 has disappeared from the detection target area RAR based on the position data POS supplied from the radar device 12 (FIGS. 7(B) and 8(B)). The light distribution control unit 24 measures the length of the period during which the rear side detection DA is on (time Ton).

In this way, when the time ΔT from when the rear detection DB is turned on until the rear side detection DA is turned on is longer than the predetermined time T2 and shorter than the predetermined time T1 (T2<ΔT<T1), the light distribution control unit 24 changes the light distribution state S from the light distribution state SA (FIG. 4) to the light distribution state SB (FIG. 5) at the earlier of the time t23 (FIG. 7) when the predetermined time T3 (e.g., the time equivalent to 20 frames) has elapsed from the time t22, t32 when the rear side detection DA is turned on, and the time t35 (FIG. 8) when the rear side detection DA is turned off (FIGS. 7(C) and 8(C)). In the light distribution state SB (FIG. 5), the illumination range of the headlamp 13 is limited compared to the light distribution state SA (FIG. 4).

Then, at these timings t23 and t35, the light distribution control unit 24 starts a counting operation by counting the number of frames of the stereo image PIC (FIGS. 7(D) and 8(D)). As a result, the count value increases over time.

The vehicle 90 continues traveling from the right side of the vehicle 10 toward the right front. At this time, in the light distribution state SB, as shown in FIG. 5, the illumination range of the headlamp 13 is limited so that the right side of the illumination range is missing. This reduces the possibility that the driver of the vehicle 90 will feel glare due to light reflected by, for example, the door mirror of the vehicle 90.

Then, based on the count value in the counting operation, the light distribution control unit 24 changes the light distribution state S from the light distribution state SB (FIG. 5) back to the light distribution state SA (FIG. 4) at the timing t15 when the time T (=Ton×N) that is N times the time Ton has elapsed from the timings t23 and t35 (FIGS. 7(C) and 8(D)). Here, "N" can be, for example, "5".

(Case C3)
9 shows an example of the operation of the light distribution control device 25 when the speed difference ΔSP between the speed SP90 of the vehicle 90 and the speed SP10 of the vehicle 10 is small. Before timing t41, the vehicle 90 is traveling behind the vehicle 10. Then, the vehicle 90 approaches the detection target region RBR.

At timing t41, the rear vehicle detection unit 23 detects the vehicle 90 in the detection target region RBR based on the position data POS supplied from the radar device 12 (FIG. 9(A)). After that, the distance between the vehicle 10 and the vehicle 90 continues to decrease as time passes.

Then, at a timing t42, which is a time period shorter than the predetermined time T2 after the timing t41, the rear vehicle detection unit 22 detects a vehicle 90 in the detection target area RAR based on the position data POS supplied from the radar device 12 (Figure 9 (B)).

At timing t43, the rear vehicle detection unit 23 detects that the vehicle 90 has disappeared from the detection target area RBR based on the position data POS supplied from the radar device 12 (FIG. 9(A)). Then, at timing t44, the rear side vehicle detection unit 22 detects that the vehicle 90 has disappeared from the detection target area RAR based on the position data POS supplied from the radar device 12 (FIG. 9(B)). The light distribution control unit 24 measures the length of the period during which the rear side detection DA is on (time Ton).

In this way, when the time ΔT from when the rear detection DB is turned on until the rear side detection DA is turned on is shorter than the time T2 (ΔT<T2), the light distribution control unit 24 changes the light distribution state S from the light distribution state SA (FIG. 4) to the light distribution state SB (FIG. 5) at the timing t44 when the rear side detection DA is turned off (FIG. 9(C)). In the light distribution state SB (FIG. 5), the illumination range of the headlamp 13 is more limited than in the light distribution state SA (FIG. 4).

Then, at this timing t44, the light distribution control unit 24 starts the counting operation by counting the number of frames of the stereo image PIC (FIG. 9(D)). As a result, the count value increases over time.

The vehicle 90 continues traveling from the right side of the vehicle 10 toward the right front. At this time, in the light distribution state SB, as shown in FIG. 5, the illumination range of the headlamp 13 is limited so that the right side of the illumination range is missing. This reduces the possibility that the driver of the vehicle 90 will feel glare due to light reflected by, for example, the door mirror of the vehicle 90.

Then, based on the count value in the counting operation, at timing t45, which is N times the time Ton (= Ton × N) after timing t44, the light distribution control unit 24 changes the light distribution state S from the light distribution state SB ( FIG. 5 ) back to the light distribution state SA ( FIG. 4 ) ( FIG. 9 (C)). Here, "N" can be, for example, "5".

In the above, three cases C1 to C3 have been considered according to the speed difference ΔSP between the speed SP90 of vehicle 90 and the speed SP10 of vehicle 10. In this way, in this example, the focus has been on the speed difference ΔSP, but the results of rear-side detection DA and rear-side detection DA may change depending on the road shape, such as a curve, for example. Even in this case, the operation is performed as in cases C1 to C3.

In this way, the light distribution control unit 24 determines the timing for changing the light distribution state S from the light distribution state SA (FIG. 4) to the light distribution state SB (FIG. 5) based on the detection timing of the rear side detection DA. As shown in cases C1 to C3, the light distribution control unit 24 adjusts the timing for changing the light distribution state S from the light distribution state SA (FIG. 4) to the light distribution state SB (FIG. 5) depending on the length of the time ΔT from when the rear detection DB is turned on to when the rear side detection DA is turned on. The light distribution control unit 24 adjusts the timing for changing the light distribution state S from the light distribution state SA (FIG. 4) to the light distribution state SB (FIG. 5) within the timing range from when the rear side detection DA is turned on to when the rear side detection DA is turned off.

Here, the time ΔT corresponds to a specific example of "elapsed time" in this disclosure. The predetermined time T1 corresponds to a specific example of "first time" in this disclosure. The predetermined time T2 corresponds to a specific example of "second time" in this disclosure.

(Operation of light distribution control unit 24)
FIG. 10 shows an example of the operation of the light distribution control unit 24.

First, the light distribution control unit 24 checks whether the rear detection DB by the rear vehicle detection unit 23 is on (step S101). If the rear detection DB is off ("N" in step S101), the process of step S101 is repeated until the rear detection DB is on.

If the rear detection DB is on in step S101 ("Y" in step S101), the light distribution control unit 24 checks whether the rear side detection DA by the rear side vehicle detection unit 22 is on (step S102). If the rear side detection DA is off ("N" in step S102), the process of step S102 is repeated until the rear side detection DA is on.

In step S102, if the rear side detection DA is on ("Y" in step S102), the light distribution control unit 24 checks whether the time ΔT from when the rear detection DB is turned on until the rear side detection DA is turned on is shorter than a predetermined time T2 (ΔT<T2) (step S103). If the time ΔT is shorter than the predetermined time T2 ("Y" in step S103), the light distribution control unit 24 checks whether the rear side detection DA is off (step S104). If the rear side detection DA is still on ("N" in step S104), the process of step S104 is repeated until the rear side detection DA is turned off. If the rear side detection DA is turned off ("Y" in step S104), the light distribution control unit 24 changes the light distribution state S from the light distribution state SA to the light distribution state SB (step S108). That is, if the time ΔT is shorter than the predetermined time T2, the light distribution control unit 24 changes the light distribution state S from the light distribution state SA to the light distribution state SB when the rear side detection DA is turned off. This operation corresponds to case C3 (FIG. 9). Then, after the time T (=Ton×N) has elapsed since the light distribution state S was changed in step S109, the light distribution state S is returned to the light distribution state SA (step S109).

In step S103, if the time ΔT is not shorter than the predetermined time T2 ("N" in step S103), the light distribution control unit 24 checks whether the time ΔT is longer than the predetermined time T2 and shorter than the predetermined time T1 (T2<ΔT<T1) (step S105). If the time ΔT is longer than the predetermined time T2 and shorter than the predetermined time T1 ("Y" in step S105), the light distribution control unit 24 checks whether the rear side detection DA is off (step S106). If the rear side detection DA is still on ("N" in step S106), the light distribution control unit 24 checks whether a predetermined time T3 has elapsed since the rear side detection DA was turned on (step S107). If the predetermined time T3 has not yet elapsed ("N" in step S107), the process returns to step S106. When the rear side detection DA is on ("Y" in step S106) or when a predetermined time T3 has elapsed ("Y" in step S107), the light distribution control unit 24 changes the light distribution state S from the light distribution state SA to the light distribution state SB (step S108). That is, when the time ΔT is longer than the predetermined time T2 and shorter than the predetermined time T1, the light distribution control unit 24 changes the light distribution state S from the light distribution state SA to the light distribution state SB at the earlier of the timing when the predetermined time T3 has elapsed since the rear side detection DA was turned on and the timing when the rear side detection DA was turned off. This operation corresponds to case C2 (FIGS. 7 and 8). Then, after the time T (=Ton×N) has elapsed since the light distribution state S was changed in step S109, the light distribution state S is returned to the light distribution state SA (step S109).

In step S105, if the time ΔT does not satisfy the condition that it is longer than the predetermined time T2 and shorter than the predetermined time T1 ("N" in step S105), the time ΔT is longer than the predetermined time T1 (ΔT>T1), so the light distribution control unit 24 changes the light distribution state S from the light distribution state SA to the light distribution state SB (step S108). That is, if the time ΔT is longer than the predetermined time T1, the light distribution control unit 24 changes the light distribution state S from the light distribution state SA to the light distribution state SB when the rear side detection DA is turned on. This operation corresponds to case C1 (FIG. 6). Then, after the time T (=Ton×N) has elapsed since the light distribution state S was changed in step S109, the light distribution state S is returned to the light distribution state SA (step S109).

This completes the process.

In this way, the light distribution control device 25 includes a rear side vehicle detection unit 22 that detects vehicles 90 within a predetermined detection target area RA on the rear side of the vehicle 10 based on the detection results of the radar device 12 provided on the vehicle 10, and a light distribution control unit 24 that determines the change timing (e.g., timings t12, t23, t35, t44) for changing the light distribution state S of the headlamp 13 provided on the vehicle 10 based on the first timing (e.g., timings t12, t22, t32, t42) at which the rear side vehicle detection unit 22 detects the vehicle 90. This allows the light distribution control device 25 to effectively control the light distribution of the headlamp.

That is, for example, when the processing unit 20 detects a vehicle 90 passing the vehicle 10 based on the imaging result of the stereo camera 11, the light distribution state S of the headlamp 13 may be changed from the light distribution state SA (FIG. 4) to the light distribution state SB (FIG. 5). At night, for example, the processing unit 20 can detect the vehicle 90 by detecting the tail lamp of the vehicle 90. However, in this case, as shown in FIG. 11, even if the vehicle 90 is traveling diagonally ahead of the vehicle 10, if the tail lamp of the vehicle 90 is not within the range corresponding to the angle of view of the stereo camera 11, the processing unit 20 cannot detect the vehicle 90. Therefore, since the light distribution state S is maintained at the light distribution state SA, the driver of the vehicle 90 may feel glare due to light reflected by, for example, the door mirror of the vehicle 90.

On the other hand, the light distribution control device 25 detects the vehicle 90 in a predetermined detection target area RA on the rear side of the vehicle 10 based on the detection result of the radar device 12, and determines the change timing for changing the light distribution state S of the headlamp 13 based on the first timing when the vehicle 90 is detected. As a result, as shown in Figures 4 and 5, the change timing for changing the light distribution state S of the headlamp 13 is determined based on the timing when the vehicle 90 enters the predetermined detection target area RA, so that when the vehicle 90 is traveling diagonally ahead of the vehicle 10, the light distribution state S can be changed to the light distribution state SB. This makes it possible for the driver of the vehicle 90 to feel less glare in the vehicle 10, so that the light distribution control of the headlamp can be performed effectively.

The light distribution control device 25 further includes a rear vehicle detection unit 23 that detects vehicles behind the detection target area RA based on the detection results of the radar device 12. The light distribution control unit 24 determines the timing to change the light distribution state S of the headlamp 13 based on the time ΔT from the second timing (e.g., timings t11, t21, t31, t41) at which the rear vehicle detection unit 23 detects the vehicle 90 to the first timing. This makes it possible to adjust the timing to change the light distribution state S depending on, for example, the road shape, such as a curve, and the speed difference ΔSP between the speed SP90 of the vehicle 90 and the speed SP10 of the vehicle 10.

Specifically, for example, when the time ΔT is longer than a predetermined time T1, the light distribution control device 25 can determine the change timing based on the first timing (timing t12) when the rear side vehicle detection unit 22 detects the vehicle 90, as shown in case C1 (FIG. 6). That is, when the speed difference ΔSP between the speed SP90 of the vehicle 90 and the speed SP10 of the vehicle 10 is large, the light distribution state S can be changed to the light distribution state SB at an early timing. This enables the vehicle 10 to make it difficult for the driver of the vehicle 90 that is quickly overtaking the vehicle 10 to feel glare.

For example, when the time ΔT is shorter than the predetermined time T2, the light distribution control device 25 can determine the change timing based on the timing when the rear side vehicle detection unit 22 no longer detects the vehicle 90, as shown in case C3 (FIG. 9). That is, when the speed difference ΔSP between the speed SP90 of the vehicle 90 and the speed SP10 of the vehicle 10 is small, the light distribution state S can be changed to the light distribution state SB at a late timing. This allows the vehicle 10 to make it difficult for the driver of the vehicle 90 slowly overtaking the vehicle 10 to feel glare.

In this example, as shown in Figures 6 to 9, the timing for changing the light distribution state S can be adjusted within a timing range from the timing when the rear side vehicle detection unit 22 detects the vehicle 90 to the timing when the rear side vehicle detection unit 22 no longer detects the vehicle 90.

In this way, the light distribution control device 25 can adjust the timing for changing the light distribution state S according to the speed difference ΔSP between the speed SP90 of the vehicle 90 and the speed SP10 of the vehicle 10, thereby effectively controlling the light distribution of the headlamps.

[effect]
As described above, this embodiment is equipped with a rear side vehicle detection unit that detects vehicles within a specified area on the rear side of the vehicle based on the detection results of a radar device installed in the vehicle, and a light distribution control unit that determines the timing to change the light distribution state of the headlamps installed in the vehicle based on the first timing at which the rear side vehicle detection unit detects a vehicle, so that light distribution control of the headlamps can be performed effectively.

In this embodiment, a rear vehicle detection unit is further provided that detects vehicles behind the area based on the detection results of the radar device. Then, the timing for changing the light distribution state of the headlamps is determined based on the time from the second timing at which the rear vehicle detection unit detects a vehicle to the first timing. This allows for effective light distribution control of the headlamps.

Although the present technology has been described above using embodiments, the present technology is not limited to these embodiments and can be modified in various ways.

For example, in the above embodiment, the light distribution control unit 24 measures time using the number of frames of the stereo image PIC, but this is not limited to this, and instead, time can be measured based on, for example, a clock signal having an arbitrary frequency.

Note that the effects described in this specification are merely examples and are not limiting, and other effects may also be present.

1...In-vehicle system, 9...Windshield, 10...Vehicle, 11...Stereo camera, 11L...Left camera, 11R...Right camera, 12...Radar device, 13...Headlamp, 13L...Left headlamp, 13R...Right headlamp, 20...Processing unit, 21...Exterior environment detection unit, 22...Rear side vehicle detection unit, 23...Rear vehicle detection unit, 24...Light distribution control unit, DA...Rear side detection, DB...Rear detection, PIC...Stereo image, PL...Left image, POS...Position data, PR...Right image, RA, RAL, RAR, RB, RBL, RBR...Detection target area, S, SA, SB...Light distribution state.

Claims (5)

a first detection unit that detects a second vehicle within a predetermined area on a rear side of the first vehicle based on a detection result of a radar device provided in the first vehicle;
a second detection unit that detects the second vehicle behind the predetermined area based on a detection result of the radar device;
a light distribution control unit that determines a change timing for changing a light distribution state of a headlamp provided in the first vehicle based on a first timing at which the first detection unit detects the second vehicle ,
The light distribution control unit determines the change timing based on an elapsed time from a second timing at which the second detection unit detects the second vehicle to the first timing.
Light distribution control device. When the elapsed time is longer than a first time, the light distribution control unit determines the change timing based on the first timing.
The light distribution control device according to claim 1 . When the elapsed time is shorter than a second time, the light distribution control unit determines the change timing based on a timing at which the first detection unit no longer detects the second vehicle.
The light distribution control device according to claim 1 or 2 . When the elapsed time is shorter than the first time and longer than the second time, the light distribution control unit determines the change timing based on the earlier of a timing when a predetermined length of time has elapsed from the first timing and a timing when the first detection unit no longer detects the second vehicle.
The light distribution control device according to claim 1 . one or more processors; and one or more memories communicatively coupled to the one or more processors,
The one or more processors:
performing a first detection for detecting a second vehicle within a predetermined area on a rear side of the first vehicle based on a detection result of a radar device provided on the first vehicle;
performing a second detection to detect the second vehicle behind the predetermined area based on a detection result of the radar device;
Using a first timing at which the second vehicle is detected by the first detection as a reference, a change timing for changing a light distribution state of a headlamp provided on the first vehicle is determined based on an elapsed time from a second timing at which the second vehicle is detected by the second detection to the first timing .
Light distribution control device.

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