CN111660918B - Control device and control method for vehicle headlamp, and vehicle headlamp system - Google Patents

Abstract

The present invention provides a control device and control method for a vehicle headlamp, and a vehicle headlamp system, which can take into account both the rapid recovery of visibility of pedestrians and the reduction of discomfort caused to the driver. A control device for a vehicle headlamp, the control device is used to control the light irradiation of the vehicle headlamp, wherein when the headlamp forms a first irradiation light and a second irradiation light at a position relatively lower than the first irradiation light, a first time required from the start of the formation until the brightness of the first irradiation light increases to a specified value is made longer than a second time required from the start of the formation until the brightness of the second irradiation light increases to a specified value.

Description

Control device and control method for vehicle headlamp, and vehicle headlamp system

Technical Field

The present invention relates to a lighting control technology for a vehicle lamp, wherein the vehicle lamp performs selective light irradiation according to the position of a preceding vehicle.

Background technique

As a vehicle lamp, a vehicle lamp is known that controls the light irradiation range of the driving light (high beam) emitted from the headlight in a variably manner according to the position of the oncoming vehicle or the preceding vehicle (hereinafter, collectively referred to as the "front vehicle") in front of the vehicle. In such a vehicle lamp, the light distribution state of the headlight of the vehicle is controlled so that, when there is a front vehicle, only the range corresponding to the position of the front vehicle is shielded (or dimmed) and the light is irradiated to the range outside the range. Such light distribution control is also called ADB (Adaptive Driving Beam) control.

Regarding the above-mentioned vehicle lamp, for example, Japanese Patent Publication No. 2017-81500 (Patent Document 1) describes a vehicle lamp system that dynamically controls light distribution so that the front vehicle adapts to the non-irradiated area, wherein the vehicle lamp system includes: a vehicle lamp that can form a plurality of light distribution patterns; a selection unit that selects a light distribution pattern to be formed by the vehicle lamp based on the plurality of light distribution patterns; and a setting unit that sets at least one switching time parameter based on the current light distribution pattern formed by the vehicle lamp and the new light distribution pattern newly selected by the selection unit, wherein the switching time parameter determines the time required to switch from the current light distribution pattern to the new light distribution pattern. The following description is made: In the vehicle lamp system, for example, when the front vehicle is about to enter the irradiation range (irradiation area), the light distribution pattern is quickly switched to reduce the irradiation range. On the other hand, when the irradiation area is expanded, the control of switching the light distribution pattern slowly can take into account both the strong light countermeasure for the front vehicle and the reduction of the discomfort caused to the driver of the vehicle.

However, when the light distribution pattern is switched slowly while the illumination area is expanded, a disadvantage such as a pedestrian on the road side may take time to be easily visible. On the other hand, when the light distribution pattern is switched quickly to solve this disadvantage, the driver may feel uncomfortable as described above. Therefore, the following technology is preferred: it is possible to take into account both the requirements of quickly restoring the visibility of pedestrians and the reduction of the discomfort caused to the driver.

Prior art literature

Patent Literature

Patent Document 1: Japanese Patent Application Publication No. 2017-81500

Summary of the invention

Problems to be solved by the invention

One of the objects of a specific aspect of the present invention is to provide a technology capable of achieving both rapid recovery of visibility of pedestrians and the like and reduction of discomfort given to the driver.

Means for solving problems

[1] One aspect of the present invention is a control device for a vehicle headlamp, (a) the control device is used to control light irradiation performed by the vehicle headlamp, wherein (b) when the headlamp is caused to form a first irradiation light and a second irradiation light at a position relatively lower than the first irradiation light, a first time required from the start of the formation until the brightness of the first irradiation light increases to a specified value is made longer than a second time required from the start of the formation until the brightness of the second irradiation light increases to a specified value.

[2] One aspect of the present invention is a control device for a vehicle headlamp, (a) the control device is used to control light irradiation performed by the vehicle headlamp, wherein (b) the control device includes: an indication unit that instructs the headlamp to form a first irradiation light and a second irradiation light at a position relatively lower than the first irradiation light; and (c) a lighting control unit that controls the lighting of the headlamp when the indication is given by the indication unit so that a first time required from the formation of the first irradiation light to the increase of its brightness to a specified value is longer than a second time required from the formation of the first irradiation light to the increase of its brightness to a specified value.

[3] One aspect of the present invention is a method for controlling a vehicle headlamp, (a) the method being used to control light irradiation by the vehicle headlamp, wherein (b) when the headlamp is caused to form a first irradiation light and a second irradiation light at a position relatively lower than the first irradiation light, a first time required from the start of the formation until the brightness of the first irradiation light increases to a specified value is made longer than a second time required from the start of the formation until the brightness of the second irradiation light increases to a specified value.

[4] One aspect of the present invention is a vehicle headlamp system including: the control device described above; and a vehicle headlamp that is controlled by the control device to form a first irradiation light and a second irradiation light.

According to the above-described configurations, it is possible to achieve both rapid recovery of visibility of pedestrians and the like and reduction of discomfort given to the driver.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing a configuration of a vehicle lighting system according to an embodiment.

FIG. 2 is a diagram for explaining an intermediate beam formed by an intermediate beam unit and a high beam formed by a high beam unit.

FIG. 3 is a diagram for explaining the lighting timing when turning on and off the lamp units 14L and 14R.

FIG. 4 is a schematic diagram for explaining the lighting control of the vehicle lighting system.

FIG. 5 is a flowchart showing a processing procedure of lighting control by the control device.

Description of symbols

10: Camera device; 11: Camera; 12: Image processing unit; 13: Control device; 14L, 14R: Light unit; 20: Vehicle detection unit; 21: Light distribution setting unit; 22: Lighting time setting unit; 23: Control signal generating unit; 30: Drive circuit; 31: Middle beam unit; 32: High beam unit; 100, 100L, 100R: Middle beam; 101: High beam; 110: Front vehicle

Detailed ways

Fig. 1 is a block diagram showing the configuration of a vehicle lamp system according to an embodiment of the present invention. The vehicle lamp system shown in the figure includes an imaging device 10, a control device (lighting control device) 13, and a pair of lamp units (vehicle lamps) 14L and 14R.

The camera device 10 includes a camera 11 and an image processing unit 12. The camera 11 is disposed at a predetermined position of the vehicle (e.g., above the front window glass in the vehicle compartment) to capture the front of the vehicle. The image processing unit 12 detects an object existing in front of the vehicle by performing predetermined image processing on the image (video) captured by the camera 11. The "object" referred to here refers to, for example, a vehicle in front, a pedestrian, a bicycle rider, an obstacle, a road marking such as a white line on the road surface, and the like.

Furthermore, when the vehicle is equipped with a device equivalent to the camera 10 for use in devices related to other purposes (for example, a steering assist function, an automatic braking function, etc.), the camera 10 may be omitted by using its output.

The control device 13 is implemented by a computer system having a CPU (central processing unit), a ROM (read only memory), a RAM (random access memory), etc., and is implemented by executing a predetermined action program in the computer system. The control device 13 includes a vehicle detection unit 20, a light distribution setting unit 21, a lighting time setting unit 22, and a control signal generation unit 23 as functional blocks.

The vehicle detection unit 20 determines whether there is a leading vehicle based on the image processing result output from the image processing unit 12 of the imaging device 10 , and acquires the position of the leading vehicle if there is one.

The light distribution setting unit 21 variably sets the light distribution pattern according to the position of the front vehicle detected by the camera device 10. The light distribution pattern includes a light irradiation range and a dimming range (light non-irradiation range). For example, a fixed range set corresponding to the position of the front vehicle is set as the dimming range, and a range corresponding to the position where there is no front vehicle is set as the light irradiation range.

The lighting time setting unit 22 sets the lighting time when turning on and off each lamp unit 14L, 14R. The lighting time referred to here is the time required from a predetermined state where the brightness of the light emitted by each lamp unit 14L is relatively low (for example, the lighting state) to a predetermined state where the brightness is relatively high (for example, the lighting state with 100% brightness).

The control signal generating unit 23 generates a control signal (light distribution control signal) for turning on and off each lamp unit 14L, 14R according to the light distribution pattern set by the light distribution setting unit 21 and the lighting time set by the lighting time setting unit 22, and outputs the control signal to each lamp unit 14L, 14R.

Each lamp unit 14R, 14L is provided one on each side of the front portion of the vehicle and is used to irradiate light in front of the vehicle. Each of the lamp units 14R, 14L includes a drive circuit 30, a center beam unit 31, and a high beam unit 32.

The drive circuit 30 drives the center beam unit 31 and the high beam unit 32 according to the control signal supplied from the control signal generating section 23 of the control device 13 .

The intermediate beam unit 31 is configured to include a plurality of light emitting elements (LEDs) arranged in a matrix, for example, and a lens for focusing and projecting light emitted from these light emitting elements, and receives driving power from the driving circuit 30 to form an intermediate beam (see FIG. 2 described later). Each light emitting element of the intermediate beam unit 31 can be turned on and off independently, and by turning each light emitting element on and off appropriately, a dimming range can be selectively set for a part of the intermediate beam.

The high beam unit 32 includes a plurality of light emitting elements (LEDs) arranged in a matrix, for example, and a lens for focusing and projecting light emitted from these light emitting elements, and receives drive power from the drive circuit 30 to form a high beam (see FIG. 2 described later).

Fig. 2 is a diagram for explaining the intermediate beam formed by the intermediate beam unit and the high beam formed by the high beam unit. Fig. 2 schematically shows the shapes and arrangements of the beams on a virtual screen at a predetermined position (e.g., 25 meters in front) in front of the vehicle. Although not shown in the figure, the low beam as a conventional low beam lamp is also appropriately formed at a relatively lower side than the intermediate beam and the high beam.

Fig. 2 (A) shows an intermediate beam formed by the intermediate beam unit 31 of the lamp unit 14L. The intermediate beam 100L is formed in a range deviated to the left with respect to the front of the vehicle (0° on the horizontal axis), and is formed in a range from a position slightly exceeding the horizontal line (0° on the vertical axis) (around 1°) to the lower side.

2B shows an intermediate beam formed by the intermediate beam unit 31 of the lamp unit 14R. The intermediate beam 100R is formed in a range deviated to the right with respect to the front of the vehicle (0° on the horizontal axis) and is formed in a range from a position slightly exceeding the horizontal line (0° on the vertical axis) (around 1°) to the lower side.

By combining these intermediate light beams 100L and 100R, one intermediate light beam 100 is formed as shown in Fig. 2(D) . The intermediate light beam 100 can be switched on and off for each of a plurality of regions in the left-right direction (horizontal direction) in the figure.

FIG2(C) shows the high beam formed by each high beam unit 32 of the lamp unit 14L, 14R. The high beam 101 is formed in a range that is equal to the left and right based on the front of the vehicle (0° on the horizontal axis), and is formed in a range from a position slightly below the horizontal line (0° on the vertical axis) (position around -2°) to a position higher than the horizontal line (position of 5 to 6° on the vertical axis). The light from each high beam unit 32 is superimposed into one to form the high beam 101.

As shown in FIG. 2 (D), the high beam 101 partially overlaps the middle beam 100. In the present embodiment, the lower ends of the middle beam 100 and the high beam 101 are at substantially the same position, and the upper end of the high beam 101 is relatively at an upper position. The high beam 101 is irradiated in the same range as the conventional high beam as a running light, and is used to illuminate a position farther from the vehicle.

In contrast, the intermediate beam 100 is formed at a position lower than the conventional high beam and higher than the conventional low beam as a low beam. The intermediate beam 100 is formed at a height position intermediate between the conventional high beam and low beam, and is formed wider than the high beam 101. The intermediate beam 101 is suitable for making it easier to see pedestrians, cyclists, obstacles, etc. located beside the road, in a roadside divider, etc.

In addition, in the present embodiment, a difference is provided in brightness between the middle beam 100 and the high beam 101. Specifically, when the middle beam 100 and the high beam 101 are compared, the high beam 101 is made relatively brighter than the middle beam 100. The "difference in brightness" referred to here may be a difference in brightness of the emitted light from the middle beam unit 31 and the high beam unit 32 (for example, brightness at the emission surface of the light emitting element), or a difference in illumination of the middle beam 100 and the high beam 101 actually irradiated onto the road surface (or virtual screen) by these emitted lights. In addition, the "difference in brightness" may be a difference between the brightest parts of the middle beam 100 and the high beam 101, or a difference in average values of the entire irradiation range of the middle beam 100 and the high beam 101.

FIG3 is a diagram for explaining the lighting time when the lamp units 14L and 14R are turned on and off. The lighting time here refers to the time required for the brightness of each light beam to reach the maximum value (lighting rate of 100%) from 0 (lighting rate of 0%) when the light beam is formed. In each of FIG3 (A) and FIG3 (B), the solid line represents the time change of the lighting rate of the light emitted from the middle beam unit 31, and the single-dot chain line represents the time change of the lighting rate of the light emitted from the high beam unit 32.

The lighting times exemplified in FIG. 3 (A) and FIG. 3 (B) have the following basic characteristics: the lighting rate of the middle beam reaches 100% in a relatively short time, and the lighting rate of the high beam reaches 100% in a relatively long time. In addition, various methods have been considered for continuously changing the lighting rate. For example, in the present embodiment, each light emitting element of the middle beam unit 31 and the high beam unit 32 is driven by pulse width modulation (PWM control) and its duty ratio is increased or decreased to achieve this.

In the example shown in (A) of FIG. 3 , it is indicated (judged) that each light emitting element of the intermediate beam unit 31 and the high beam unit 32 should be lit at a time point of time 0, and a waiting time T0 is set between the time 0 and the time t1 when the lighting rate actually starts to increase. The waiting time can be set to, for example, about 100 ms. The intermediate beam unit 31 is controlled to light up so that the lighting rate increases from 0% to 100% between the time t1 when the lighting rate starts to increase and the time t2. The time required from the time t1 to the time t2 can be set to, for example, about 100 ms. In contrast, from the time t1 when the lighting rate starts to increase, the high beam unit 32 is controlled to light up so that the lighting rate increases from 0% to 100% until the time t3. The time required from the time t1 to the time t3 can be set to, for example, about 1200 ms (1.2 s).

In the example shown in (B) of FIG. 3 , from the time 0 when it is indicated (judged) that each light emitting element of the middle beam unit 31 and the high beam unit 32 should be lit at the time 0, lighting is started without setting a waiting time. The middle beam unit 31 is controlled to light up so that the lighting rate increases from 0% to 100% from the time t0 when the lighting rate starts to increase to the time t21. The time required from the time t0 to the time t21 can be set to, for example, about 1000ms (1.0s). In contrast, the high beam unit 32 is controlled to light up so that the lighting rate increases from 0% to 100% from the time t0 when the lighting rate starts to increase to the time t3. The time required from the time t0 to the time t3 is, for example, about 3000ms (3.0s).

Here, it is desirable that, assuming that the time difference between the time when the lighting rate of the middle beam unit 31 reaches 100% and the time when the lighting rate of the high beam unit 32 reaches 100% in each of the above examples is time T1, the time T1 is set to be 200 ms or more. In the case of FIG. 3 (A) above, the time T1 is 1100 ms (1.1 s), and in the case of FIG. 3 (B) above, the time T1 is 2000 ms (2.0 s). In this way, by setting the time T1, the driver or the like can recognize the middle beam and the high beam as different lights when viewing the respective beams.

The setting of the above time T1 is based on the results of Wertheimer's light spot flickering experiment. Specifically, Wertheimer's light spot flickering experiment used an experimental device that flickered two light spots alternately to investigate how the visual observer's perception changed after changing the interval between the flickers. The results are as follows:

(a) When the interval between the flashing of the light spots is about 30 ms (about 33 frames/second) or less, it feels like the two light spots are lighting up at the same time (simultaneous phase).

(b) When the interval between light spot flashes is about 60 ms (about 16 frames/second), the two light spots appear to move smoothly (the most suitable phase).

(c) When the interval between light spot flashes is about 200 ms (about 5 frames/second) or more, the two light spots are seen as different light spots and no motion is perceived (continuous phase).

In addition, the method of changing the lighting rate of each of the middle beam unit 31 and the high beam unit 32 is not limited to the above-mentioned example. That is, in the above-mentioned example, the lighting rate is changed in such a way that the degree of increase of the lighting rate is small at the beginning and the degree of increase of the lighting rate is large as time goes by and gradually increases, but it is also possible to change in such a way that the degree of increase of the lighting rate is large at the beginning and the degree of increase of the lighting rate is small as time goes by and gradually increases. In addition, the lighting rate may increase linearly or in stages as time passes.

FIG. 4 is a schematic diagram for explaining the lighting control of the vehicle lighting system. FIG. 4 schematically shows the situation in front of the vehicle. As shown in FIG. 4 (A), when the front vehicle 110 (in this example, the oncoming vehicle) is detected, the dimming range is set on the right side of the figure in the middle beam 100 according to the position of the front vehicle 110, and the dimming range is turned off. In addition, the high beam 101 is also turned off. Next, as shown in FIG. 4 (B), when the front vehicle 110 leaves and cannot be detected, the range of the middle beam 100 that is turned off as the dimming range is quickly turned on, and the lighting rate reaches 100%. At this time, the high beam 101 also starts to light up, but because there is a difference in the lighting time, it is in a darker state than the middle beam 101. Thereafter, as shown in FIG. 4 (C), the lighting rate of the high beam 101 also gradually increases, and after the prescribed lighting time has passed, the lighting rate reaches 100%.

In any case, a low beam 102 (indicated by a dotted line in the figure) is irradiated by another lamp unit not shown in FIG. 1 at a relatively lower position than the intermediate beam 100 and the high beam 101. The low beam 102 referred to here is a low beam lamp, the lower end of which is set at a lower position than the lower ends of the intermediate beam 100 and the high beam 101, and is a light that can irradiate a relatively short distance in front of the vehicle.

By lighting the intermediate beam 101 relatively quickly, visibility of pedestrians can be ensured. Since the intermediate beam 101 illuminates a relatively low position, the effect on perception is small, so the discomfort of the driver can be suppressed to a small extent. In contrast, the high beam 101, which is light that illuminates a relatively high position and affects perception, is lit relatively slowly to reduce the discomfort of the driver.

In addition, when the next vehicle 110 ahead is detected while the lighting rate of the high beam 101 increases to 100%, the high beam 101 is turned off at that time, so the brightness difference caused by the lighting of the high beam 101 becomes smaller, and the driver's discomfort can be reduced from this point. As such a situation, for example, there are several vehicles ahead, the relative position of the vehicle ahead moves up and down on a slope and repeatedly enters and exits the target range of image recognition, and the vehicle ahead repeatedly appears and disappears when driving on a curve with many obstacles.

FIG5 is a flowchart showing the processing steps of the lighting control of the control device. Next, referring to the flowchart, the processing steps after the intermediate beam unit 31 and the high beam unit 32 of each lamp unit 14L, 14R are lit by the lighting operation of the light switch of the vehicle are described in detail. In addition, as long as the results do not cause contradictions or inconsistencies, the various processes shown in the figure can also be executed in a reverse order, and such a form is not excluded.

The vehicle detection unit 20 obtains the result of image processing outputted from the image processing unit 12 of the camera device 10, and determines whether there is a vehicle ahead based on the result (step S11). If there is no vehicle ahead, the process is repeated (step S11: No). If there is a vehicle ahead (step S11: Yes), the vehicle detection unit 20 obtains the position of the vehicle ahead.

When the position of the vehicle ahead is obtained by the vehicle detection unit 20, the light distribution setting unit 21 sets the light distribution pattern corresponding to the position of the vehicle ahead, that is, the light irradiation range and the dimming range (non-irradiation range) (step S12). Here, a fixed range corresponding to the position of the vehicle ahead in the full irradiation range of the intermediate light beam 100 is set as the dimming range, a range corresponding to the position where there is no vehicle ahead is set as the light irradiation range, and the full irradiation range of the high beam 101 is set as the dimming range, and the formation instructions of each light beam are given to the control signal generation unit 23 (refer to (A) of FIG. 4).

Next, the control signal generating unit 23 generates a control signal (light distribution control signal) for turning on and off each lamp unit 14L, 14R based on the light distribution pattern set by the light distribution setting unit 21, and outputs it to each lamp unit 14L, 14R. Therefore, the high beam 101 is turned off in the entire range, and the middle beam 101 is turned off in the dimming range (step S13). The illumination range in the middle beam 101 is kept on.

Next, the vehicle detection unit 20 obtains the image processing result output from the image processing unit 12 of the camera device 10, and determines whether the vehicle ahead has disappeared based on the result (step S14). If the vehicle ahead has not disappeared (step S14: No), the process returns to the above-mentioned step S12, and the illumination range and dimming range are set according to the position of the vehicle ahead at the current time point (step S12), and the corresponding on/off control is performed (step S13).

When the vehicle ahead disappears (step S14: Yes), the light distribution setting unit 21 sets the light distribution pattern when the vehicle ahead does not exist. That is, the dimming range in the middle beam 100 is set as the irradiation range, and the full irradiation range of the high beam 101 is set as the irradiation range, and the formation instruction of each beam is given to the control signal generating unit 23. In addition, the lighting time setting unit 22 sets the lighting time when each lamp unit 14L, 14R is turned on and off (step S15), and the control signal generating unit 23 generates a control signal for turning each lamp unit 14L, 14R on and off according to the set lighting time, and outputs it to each lamp unit 14L, 14R. Therefore, the middle beam 100 is turned on relatively quickly, and the high beam 101 is turned on relatively slowly (step S16).

When the control signal generating unit 23 outputs the control signal to each lamp unit 14L, 14R in step S16, the process returns to the above-mentioned step S11 and the subsequent processing is performed. Therefore, for example, when the next vehicle ahead appears during the period when the lighting rate of the high beam 101 has not reached 100% (step S11), the dimming range is set accordingly (step S12), and the high beam 101 is turned off (step S13).

According to the above-described embodiment, it is possible to achieve both rapid recovery of visibility of pedestrians and the like and reduction of discomfort given to the driver.

In addition, the present invention is not limited to the contents of the above-mentioned embodiments, and can be implemented in various modifications within the scope of the main purpose of the present invention. For example, in the above-mentioned embodiments, non-irradiation (lighting rate 0%) is shown as a typical example of dimming corresponding to the position of the vehicle in front, but as another example of dimming, the brightness of the light can also be reduced to a level that does not give strong light.

In addition, in the above-mentioned embodiment, as for the intermediate beam, an intermediate beam unit having a plurality of light emitting elements is cited as a structural example for selectively irradiating light for each portion, but the present invention is not limited thereto. For example, a light modulating device (liquid crystal device, etc.) may be used, wherein the light modulating device has a light source and a plurality of light shielding elements capable of transmitting and shielding light from the light source for each portion.

Furthermore, in the above-described embodiment, selective light irradiation is performed on the intermediate light beam, but the present invention is not limited thereto, and the entire intermediate light beam may be controlled to either be turned off or turned on.

Claims (8)

1. A control device for a vehicle headlamp, the control device being used to control light irradiation by the vehicle headlamp, wherein: When the headlight forms a first irradiation light and a second irradiation light at a relatively lower position than the first irradiation light, a first time required from the start of the formation until the brightness of the first irradiation light increases to a predetermined value is made longer than a second time required from the start of the formation until the brightness of the second irradiation light increases to a predetermined value, When there is another vehicle ahead, the first illumination light is dimmed, and a portion of the second illumination light is dimmed according to the position of the other vehicle. From the time when the other vehicle disappears, the brightness of the first illumination light is increased by the first time, and the brightness of a portion of the second illumination light is increased by the second time. 2. The vehicle headlamp control device according to claim 1, wherein: The second irradiation light is formed such that at least the upper end thereof is located lower than the upper end of the first irradiation light. 3. The vehicle headlamp control device according to claim 1 or 2, wherein: The first time is longer than the second time by more than 200 milliseconds. 4. The vehicle headlamp control device according to claim 1 or 2, wherein: During the first time period, the brightness of the first irradiation light gradually increases. 5. The vehicle headlamp control device according to claim 1 or 2, wherein: The first irradiation light and the second irradiation light are formed to partially overlap. 6. A control device for a vehicle headlamp, the control device being used to control light irradiation by the vehicle headlamp, wherein: The control device comprises: an instruction unit for instructing the headlamp to form a first irradiation light and a second irradiation light at a position relatively lower than the first irradiation light; and a lighting control unit that controls the lighting of the headlight when the instruction from the instruction unit is received so that a first time required from the start of formation of the first irradiation light until its brightness increases to a predetermined value is longer than a second time required from the start of formation until the brightness of the second irradiation light increases to the predetermined value, The lighting control unit dims the first illumination light when there is another vehicle ahead, and dims a portion of the second illumination light according to the position of the other vehicle, and from the time when the other vehicle disappears, increases the brightness of the first illumination light by the first time, and increases the brightness of a portion of the second illumination light by the second time. 7. A method for controlling a vehicle headlamp, the method for controlling light irradiation by the vehicle headlamp, wherein: When the headlight forms a first irradiation light and a second irradiation light at a relatively lower position than the first irradiation light, a first time required from the start of the formation until the brightness of the first irradiation light increases to a predetermined value is made longer than a second time required from the start of the formation until the brightness of the second irradiation light increases to a predetermined value, When there is another vehicle ahead, the first illumination light is dimmed, and a portion of the second illumination light is dimmed according to the position of the other vehicle. From the time when the other vehicle disappears, the brightness of the first illumination light is increased by the first time, and the brightness of a portion of the second illumination light is increased by the second time. 8. A vehicle headlamp system, the vehicle headlamp system comprising: A control device as claimed in any one of claims 1 to 6; and The vehicle headlamp is controlled by the control device to form the first irradiation light and the second irradiation light.