JP6103255B2 - Headlight control device - Google Patents

Description

  The present invention relates to a headlight control device, and more particularly, to a headlight control device that controls an LED headlight that is configured to vary the illuminance according to the irradiation range and irradiation position.

  Conventionally, various attempts have been made to improve driving comfort and safety in consideration of the driver's condition. For example, Patent Document 1 proposes a technique for assisting driving of a driver based on a state such as a pupil diameter or sweating of the driver. Further, for example, in Patent Document 2, glare (dazzle) due to external light from an oncoming vehicle or the like during night driving is reduced by irradiating the driver's eyes with light from the interior lighting and controlling the pupil diameter of the driver. Techniques to do this have been proposed.

JP 2008-217274 A JP 2007-1417 A

  Incidentally, in recent years, headlights to which LED (Light Emitting Diode) lamps that are brighter and have higher controllability than halogen lamps have been used (hereinafter referred to as “LED headlights”). A headlight to which a halogen lamp is applied is called a “halogen headlight”). According to an experiment conducted by the inventors of the present invention, when an LED headlight is used during night driving, the driver is tired by giving a tension to the driver, compared with the case of using a halogen headlight. It was suggested that this could happen.

  The present invention has been made to solve the above-described problems of the prior art, and by controlling the LED headlight based on the state of the driver, the driver tension caused by the use of the LED headlight. An object of the present invention is to provide a headlight control device capable of appropriately mitigating the state.

In order to achieve the above object, the present invention is a headlight control device for controlling an LED headlight configured to vary the illuminance according to the irradiation range and irradiation position, and detects the pupil diameter of the driver. The difference between the pupil diameter detection means, the sweat detection means for detecting the sweat of the palm of the driver, and the pupil diameter detected by the pupil diameter detection means is greater than or equal to a predetermined value, and the sweat detection means A headlight control means for controlling the irradiation range and / or the illuminance of the LED headlight so as to reduce the illuminance at the edge in the width direction in the irradiation range of the LED headlight when sweating is detected. Features.
In the present invention configured as described above, when the difference between the pupil diameter and the reference pupil diameter is equal to or greater than a predetermined value and palm sweating is detected, the driver is in a tension state (a state where the driver is concentrated). The same applies hereinafter), and the irradiation range and / or illuminance of the LED headlight is controlled to reduce the illuminance at the end in the width direction in the irradiation range of the LED headlight. The illuminance of light radiated to a reflector installed outside the roadway such as a roadside belt or road shoulder in front of the host vehicle located in a region corresponding to the end in the width direction of the irradiation range is reduced (irradiates the reflector). Including that the illuminance of the emitted light is substantially zero). Thereby, the illuminance of the reflected light from the reflecting plate by the irradiation light of the LED headlight can be reduced, that is, the illuminance of the reflected light from the reflecting plate entering the eyes of the driver can be reduced (irradiating the reflecting plate). When the illuminance of the reflected light is substantially zero, the illuminance of the reflected light from the reflecting plate is also substantially zero). Therefore, according to the present invention, the driver's tension caused by the use of the LED headlight can be moderated appropriately.
In addition, according to the present invention, the determination is made using both the pupil diameter of the driver and the sweating of the palm. Therefore, compared with the case where the determination is performed using only one of the pupil diameter and the sweating of the palm, the driver's tension The state can be determined with high accuracy.

In the present invention, preferably, the headlight control means performs control to reduce the irradiation range by the LED headlight to reduce the illuminance at the end in the width direction in the irradiation range of the LED headlight.
According to the present invention configured as described above, the irradiation range of the LED headlight is reduced, and the illuminance at the end in the width direction in the irradiation range of the LED headlight is reduced to almost zero, so that the light of the LED headlight is reduced. It is possible to prevent the reflector from being irradiated. Thereby, the reflected light from the reflecting plate is not generated, and the reflected light from the reflecting plate does not enter the driver's eyes. Therefore, the tension state of the driver caused by the use of the LED headlight can be effectively relieved.

In the present invention, preferably, the headlight control means performs control to change the optical axis of the LED headlight so that the irradiation range of the LED headlight is moved downward, and the height direction of the LED headlight is adjusted. Reduce the irradiation range.
According to the present invention configured as described above, the irradiation range in the height direction by the LED headlight is reduced by changing the optical axis of the LED headlight to move the irradiation range downward, so that the LED head It can suppress appropriately that the light of a light is irradiated to a reflecting plate.

In the present invention, it is preferable to further include a reflector detection unit that detects a reflector present in front of the host vehicle, and the headlight control unit includes a difference between the pupil diameter detected by the pupil diameter detector and the reference pupil diameter. Is greater than or equal to a predetermined value, and when the perspiration of the palm is detected by the perspiration detection means and the reflection plate is detected by the reflection plate detection means, the illuminance at the end in the width direction in the irradiation range of the LED headlight is reduced. In this manner, the irradiation range and / or illuminance of the LED headlight is controlled.
According to the present invention thus configured, the driver's tension state is determined based on the driver's pupil diameter and palm sweating, and the environment ahead of the host vehicle is determined based on the presence or absence of the reflector in front of the host vehicle. It is determined whether the situation is a situation that makes the driver tense, and if it is determined that the driver is in a tense condition and the environmental situation is a situation that makes the driver tense, the LED Control to change the irradiation mode of the headlight is performed. Thereby, the illumination mode of the LED headlight can be changed only when the driver's tension state is caused by the environmental situation, and the LED headlight is wasted when the driver's tension state is not caused by the environmental situation. Changes in the irradiation mode can be suppressed.

  According to the headlight control device of the present invention, by controlling the LED headlight based on the state of the driver, it is possible to appropriately relieve the driver's tension caused by the use of the LED headlight.

1 is a schematic configuration diagram of a headlight control system to which a headlight control device according to an embodiment of the present invention is applied. FIG. 2 is a diagram for explaining a configuration of a high beam LED according to an embodiment of the present invention. FIG. 2A is a plan view showing a schematic configuration of the high beam LED, and FIGS. It is a schematic diagram which shows the specific example of the irradiation pattern by LED. It is a figure for demonstrating the structure of the low beam LED by embodiment of this invention. It is a figure which shows the change of the pupil diameter of the driver obtained when carrying out steady driving | running | working on the circumference circuit at night. It is a figure which shows the sweating state of the driver obtained when carrying out steady driving | running | working on the circumference circuit at night. It is a figure for demonstrating the control method by the headlight control part in embodiment of this invention. It is a flowchart which shows the headlight control process by embodiment of this invention. It is a figure for demonstrating the control method by the headlight control part in the other example of embodiment of this invention.

  Hereinafter, a headlight control device according to an embodiment of the present invention will be described with reference to the accompanying drawings.

[Device configuration]
First, a specific configuration of a headlight control apparatus according to an embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is a schematic configuration diagram of a system (headlight control system) to which a headlight control device according to an embodiment of the present invention is applied.

  As shown in FIG. 1, the headlight control system 100 mainly includes a control unit 10, a front camera 21, an illuminance sensor 22, a driver monitoring camera 23, a steering sweat sensor 24, a vehicle speed sensor 25, and an LED. A headlight 30. The headlight control system 100 is a system applied to various vehicles.

  The front camera 21 is a camera that captures a landscape in front of the vehicle, and supplies a signal corresponding to the captured image data to the control unit 10. The illuminance sensor 22 is a sensor that detects the illuminance in front of the vehicle, and supplies a signal corresponding to the detected illuminance to the control unit 10. The driver monitoring camera 23 is a camera that captures the driver's eyes (such as the pupil), and supplies a signal corresponding to the captured image data to the control unit 10. The steering sweat sensor 24 is a sensor that is provided in a part of the steering (for example, a part that is likely to be gripped when the driver is driving) and detects the sweat of the palm of the driver gripping the steering. Specifically, the steering sweat sensor 24 detects a skin conductance corresponding to the degree of sweat (amount of sweat water) of the palm of the driver, and supplies a signal corresponding to the detected skin conductance to the control unit 10. The vehicle speed sensor 25 detects the vehicle speed and supplies a signal corresponding to the detected vehicle speed to the control unit 10.

  The LED headlight 30 is a first high beam LED 31a, a second high beam LED 31b, a third high beam LED 31c, and a fourth high beam LED 31d for irradiating light far upwards. And a low beam LED 32 for irradiating light in the vicinity of the host vehicle downward from the high beam LED 31. The high beam LED 31 and the low beam LED 32 are controlled by the control unit 10 (strictly speaking, the low beam LED 32 may be controlled by the control unit 10 via an actuator (not shown)).

  Here, with reference to FIG. 2, the high beam LED 31 according to the embodiment of the present invention will be described in detail. FIG. 2A is a plan view showing a schematic configuration of the high beam LED 31, and FIGS. 2B to 2D are schematic views showing specific examples of irradiation patterns by the high beam LED 31. Specifically, FIGS. 2B to 2D are diagrams of the irradiation range of the high beam LED 31 as viewed from above.

  As shown in FIG. 2A, the high beam LED 31 includes four segments (packages) in which a first high beam LED 31a, a second high beam LED 31b, a third high beam LED 31c, and a fourth high beam LED 31d are arranged in parallel in the vehicle width direction. ing. The high beam LED 31 is configured to be switched on / off separately for each of the first high beam LED 31a, the second high beam LED 31b, the third high beam LED 31c, and the fourth high beam LED 31d under the control of the control unit 10. The first high beam LED 31a, the second high beam LED 31b, the third high beam LED 31c, and the fourth high beam LED 31d can be individually changed in illuminance (light quantity). Such a high beam LED 31 is applied to each of the right and left LED headlights 30 of the vehicle.

  2B to 2D, the symbol R1 indicates the irradiation range of the right first high beam LED 31a, the symbol R2 indicates the irradiation range of the right second high beam LED 31b, and the symbol R3 indicates the right third high beam LED 31c. The reference symbol R4 indicates the irradiation range of the right fourth high beam LED 31d. Further, symbol L1 indicates an irradiation range of the left first high beam LED 31a, symbol L2 indicates an irradiation range of the left second high beam LED 31b, symbol L3 indicates an irradiation range of the left third high beam LED 31c, and symbol L4 indicates The irradiation range of the left fourth high beam LED 31d is shown.

  FIG. 2B shows an irradiation pattern when all of the first high beam LED 31a, the second high beam LED 31b, the third high beam LED 31c, and the fourth high beam LED 31d are turned on for both the right and left high beam LEDs 31. . FIG. 2C shows an irradiation pattern when only the fourth high beam LED 31d is turned off and all the other high light LEDs 31 are turned on for both the right and left high beam LEDs 31. This irradiation pattern is applied, for example, when a preceding vehicle exists on the traveling lane of the host vehicle. In FIG. 2D, for the right high beam LED 31, all of the first high beam LED 31a, the second high beam LED 31b, the third high beam LED 31c, and the fourth high beam LED 31d are turned on, and for the left high beam LED 31, the second high beam LED 31b. And the irradiation pattern at the time of making 3rd high beam LED31c light-extinguish and turning on others is shown. This irradiation pattern is applied, for example, when an oncoming vehicle exists on the opposite lane of the traveling lane of the host vehicle.

  Next, the low beam LED 32 according to the embodiment of the present invention will be described in detail with reference to FIG. FIG. 3 is a side view showing an irradiation range of the low beam LED 32 as seen from the side of the vehicle. In FIG. 3, symbols Ar <b> 11 and Ar <b> 12 each indicate an example of an irradiation range of the low beam LED 32.

  The low beam LED 32 is configured such that the optical axis is variable in the vertical direction by an actuator under the control of the control unit 10. Specifically, when the irradiation range Ar11 is applied, when the optical axis of the low beam LED 32 is raised, the irradiation range Ar11 is switched to the irradiation range Ar12 (see arrow B1). Thereby, the irradiation range by low beam LED32 will expand in the direction away from the own vehicle. For example, when the vehicle speed increases, the optical axis of the low beam LED 32 is raised, and the irradiation range by the low beam LED 32 is extended far away so that the far field of view is secured. On the other hand, when the irradiation range Ar12 is applied, when the optical axis of the low beam LED 32 is lowered, the irradiation range Ar12 is switched to the irradiation range Ar11 (see arrow B2). Thereby, the irradiation range by low beam LED32 will reduce in the direction approaching the own vehicle. For example, when the vehicle speed decreases, the optical axis of the low beam LED 32 is lowered so that the irradiation range by the low beam LED 32 is pulled back to the host vehicle side.

  In the example shown in FIG. 3, the optical axis of the low beam LED 32 is switched to two stages, but in reality, the optical axis of the low beam LED 32 can be switched to three or more stages, for example, depending on the vehicle speed, The optical axis of the low beam LED 32 is appropriately switched to a plurality of stages of 3 or more.

  Next, returning to FIG. 1, the controller 10 of the headlight control system 100 will be specifically described. The control unit 10 includes a memory such as a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). For example, the control part 10 is comprised by ECU (Electronic Control Unit) in a vehicle. The control unit 10 functionally includes a determination unit 11 and a headlight control unit 12.

  The determination unit 11 determines whether or not the irradiation mode of the LED headlight 30 should be changed based on the state of the driver and the environmental situation ahead of the host vehicle. Specifically, the determination unit 11 determines whether or not the driver is in a tension state, determines whether or not the environmental situation is a situation that causes the driver to be in a tension state, and the driver enters the tension state. If there is a situation in which the driver is in a tension state, the irradiation mode of the LED headlight 30 is determined to be changed. In this case, the determination unit 11 determines the tension state of the driver based on signals supplied from the driver monitoring camera 23 and the steering sweat sensor 24. In addition, the determination unit 11 determines whether or not a reflector (reflector) installed outside the roadway such as a roadside belt or a road shoulder exists in front of the host vehicle based on signals supplied from the front camera 21 and the illuminance sensor 22. When the reflector is present, it is determined that the environmental condition is such that the driver is in a tension state. Then, the headlight control unit 12 causes the LED head to relieve the driver's tension when the determination unit 11 determines that the irradiation mode of the LED headlight 30 should be changed. The irradiation range and / or illuminance of the light 30 is controlled.

  Although details will be described later, the driver monitoring camera 23 and the determination unit 11 correspond to the “pupil diameter detection unit” in the present invention, and the steering sweat sensor 24 and the determination unit 11 serve as the “sweat detection unit” in the present invention. The front camera 21, the illuminance sensor 22, and the determination unit 11 correspond to “reflecting plate detection means” in the present invention. The headlight control unit 12 corresponds to “headlight control means” in the present invention.

[Events discovered by the inventor]
Next, before explaining the contents of control according to the embodiment of the present invention, an event discovered by the inventor of the present invention will be described with reference to FIGS. 4 and 5.

  FIG. 4 shows changes in the pupil diameter of the driver obtained during steady running on a peripheral circuit including a straight portion and a corner portion at night. In FIG. 4, the horizontal axis indicates the elapsed time since the start of the circuit travel, and the vertical axis indicates the pupil diameter and the vehicle speed. Specifically, the graph G11 shows the temporal change of the pupil diameter obtained when the LED headlight 30 is used, and the graph G12 shows the temporal change of the pupil diameter obtained when the halogen headlight is used. The graph G13 shows the time change of the vehicle speed. Note that the pupil diameter is obtained, for example, by image analysis of the driver's pupil portion included in the image captured by the driver monitoring camera 23.

  As shown in the graphs G11 and G12 in FIG. 4, it can be seen that the pupil diameter of the driver is substantially larger when the LED headlight 30 is used than when the halogen headlight is used. Here, since the illuminance of the LED headlight 30 is generally larger than that of the halogen headlight, from the viewpoint of the illuminance, the case of using the LED headlight 30 is more than the case of using the halogen headlight. It is assumed that the pupil diameter of the driver is small (because the pupil diameter is small when the human eye is dazzling). However, from the results shown in FIG. 4, the driver's pupil diameter is actually larger when the LED headlight 30 is used than when the halogen headlight is used. The pupil diameter is increased by the action of the sympathetic nerve, and this sympathetic nerve becomes dominant when the person is nervous (conversely, the parasympathetic nerve becomes dominant when the person relaxes and the pupil diameter becomes smaller). Therefore, from the above-described experimental results on the pupil diameter, it is considered that when the LED headlight 30 is used, the driver tends to be more tensioned than when the halogen headlight is used. In other words, the driver's tension is likely to increase.

  Next, FIG. 5 shows the sweating state of the driver obtained during steady running on a circuit similar to the above at night. Specifically, FIG. 5 shows the skin conductance corresponding to the sweating state of the palm of the driver holding the steering wheel on the vertical axis, and the skin conductance obtained when the LED headlight 30 is used on the left side. The right side shows the skin conductance obtained when a halogen headlight is used.

  As shown in FIG. 5, it can be seen that the skin conductance of the palm of the driver is larger when the LED headlight 30 is used than when the halogen headlight is used, that is, the level of the degree of sweating (in other words, It can be seen that the amount of sweat water in the palm of the hand increases. The degree of sweating of the palm is also increased by the action of the sympathetic nerve that becomes dominant during human tension. Therefore, also from the experimental results on the degree of sweating of the palm, as with the pupil diameter, when the LED headlight 30 is used, the driver tends to be more tensioned than when the halogen headlight is used. It can be said that

  The present inventor has found that the driver's tension generated when the LED headlight 30 as described above is used is reflected light in the vicinity of a sharp cut line peculiar to the LED headlight 30, specifically, a roadside belt or a road shoulder. It was considered that the reflected light from the reflection plate provided in, for example, was generated by intermittently entering the driver's eyes.

[Control method]
Next, a headlight control method according to an embodiment of the present invention based on the above-described event discovered by the present inventor will be described.

  In this embodiment, in order to relieve the driver's tension that occurs when the LED headlight 30 is used as described above, that is, to reduce the driver's tension, the light from the LED headlight 30 The LED headlight 30 is controlled so that the reflection plate provided outside the roadway such as a road shoulder is not irradiated, in other words, the reflected light is not generated by the reflection plate by the light from the LED headlight 30. Specifically, in this embodiment, the headlight control unit 12 of the control unit 10 controls the lowering of the optical axis of the low beam LED 32 in the LED headlight 30 to move the irradiation range of the low beam LED 32 downward. Thus, the light from the low beam LED 32 is prevented from being applied to the reflecting plate.

  Specifically, in the present embodiment, the determination unit 11 of the control unit 10 determines whether or not the driver is in a tension state, and the environmental situation in front of the host vehicle places the driver in a tension state. When it is determined by the determination unit 11 that the driver is in a tension state and the environmental state is a state that causes the driver to be in a tension state, the headlight control unit 12 Control is performed to lower the optical axis of the low beam LED 32 so that the irradiation range of the low beam LED 32 is moved downward.

  More specifically, the determination unit 11 determines the driver's tension state based on signals supplied from the driver monitoring camera 23 and the steering sweat sensor 24. In this case, the determination unit 11 determines that the pupil diameter obtained from the image captured by the driver monitoring camera 23 is larger than the reference pupil diameter (for example, the pupil diameter obtained when the vehicle is stopped) by a predetermined value or more and the steering When sweating of the palm of the driver is detected by the sweating sensor 24, it is determined that the driver is in a tension state.

The reason why the tension state is determined based on the pupil diameter and the perspiration of the palm as described above is as follows. Since the pupil diameter responds quickly to the tension state (that is, the reactivity / responsiveness is high), the driver's tension state can be quickly determined by using the pupil diameter. Further, since the pupil diameter can be detected without contact, the driver is not burdened. However, since the pupil diameter is also affected by external illuminance, the pupil diameter decreases instantaneously in response to an increase in external light, particularly at night. Therefore, the tension state of the driver cannot be accurately determined only by the pupil diameter. It can be said. Therefore, in the present embodiment, the tension state of the driver is accurately determined by using palm perspiration in addition to the pupil diameter.
The reason why only the sweating of the palm is not used is that the sweating of the palm has low reactivity / responsiveness to the tension state, and the steering sweating sensor 24 is provided only in a part of the steering (the entire sweating is provided). This is because it is impossible to detect the sweating of the palm if the driver's palm leaves the part.

  Furthermore, when the determination unit 11 determines that the driver is in a tension state according to the above-described procedure, the environmental situation in front of the host vehicle tensions the driver based on the signals supplied from the front camera 21 and the illuminance sensor 22. It is further determined whether or not the situation is in a state. In this way, it is determined whether or not the tension state of the driver is caused by an environmental situation, and whether or not the environmental situation in front of the host vehicle causes the driver to be in a further tension state. ing. Specifically, when the determination unit 11 determines from the image captured by the front camera 21 and the illuminance in front of the host vehicle detected by the illuminance sensor 22 that the reflector is in front of the host vehicle, Determines that the driver is nervous. Thereafter, the headlight control unit 12 moves the irradiation range by the low beam LED 32 downward when the determination unit 11 determines that the environmental condition in front of the host vehicle is a situation in which the driver is in a tension state. Control to lower the optical axis of the low beam LED 32 is performed so that the

  Next, an example of a control method by the headlight control unit 12 in the embodiment of the present invention will be described with reference to FIG. FIG. 6 is a cross-sectional view of the irradiation light from the low beam LED 32 viewed from the traveling direction of the host vehicle at a position where the reflection plate 70 is installed outside the roadway such as a roadside belt or a shoulder, in other words, the reflection plate 70 is connected to the low beam LED 32. The figure (screen light distribution diagram) which distributed the screen light to the installed position is shown.

  The left side of FIG. 6 shows the irradiation range Ar21 by the low beam LED 32 when the control by the headlight control unit 12 in the present embodiment is not performed. In this case, the light from the low beam LED 32 is applied to the reflection plate 70. Therefore, the light from the low beam LED 32 is reflected by the reflecting plate 70. On the other hand, the right side of FIG. 6 shows an irradiation range Ar22 by the low beam LED 32 when the control by the headlight control unit 12 in the present embodiment is performed. In this case, the headlight control unit 12 performs control to lower the optical axis of the low beam LED 32 via the actuator, and moves the irradiation range of the low beam LED 32 downward. Specifically, the headlight control unit 12 determines only the appropriate angle such that the light from the low beam LED 32 is not irradiated on the reflecting plate 70 based on the height from the road surface of the reflecting plate 70 stipulated by laws and regulations. Then, control is performed to lower the optical axis of the low beam LED 32.

  According to such control according to the present embodiment, the light from the low beam LED 32 is not applied to the reflecting plate 70, and the reflected light from the reflecting plate 70 is not generated. Therefore, the reflected light from the reflecting plate 70 does not enter the driver's eyes, and the driver's tension caused by the use of the LED headlight 30 can be appropriately relaxed, that is, the driver can be in a resting state. it can.

  Next, a headlight control process executed by the control unit 10 in the embodiment of the present invention will be described with reference to FIG. FIG. 7 is a flowchart showing a headlight control process according to the embodiment of the present invention. This flow is repeatedly executed by the control unit 10 at a predetermined cycle.

  First, in step S11, a value obtained by subtracting the reference pupil diameter obtained in advance from the current pupil diameter obtained from the image captured by the driver monitoring camera 23 by the determination unit 11 of the control unit 10 is a predetermined value. It is determined whether or not the value (threshold) or more. In this case, the determination unit 11 obtains the current pupil diameter by performing image analysis on the pupil portion of the driver included in the image currently captured by the driver monitoring camera 23. In addition, the determination unit 11 obtains a reference pupil diameter in advance by performing image analysis on the pupil portion of the driver included in the image captured when the vehicle is stopped by the driver monitoring camera 23.

  As a result of the determination in step S11, when the value obtained by subtracting the reference pupil diameter from the current pupil diameter is equal to or larger than the predetermined value (step S11: Yes), the process proceeds to step S12, and the determination unit 11 uses the steering sweat sensor 24 to It is determined whether or not palm sweating is detected. In this case, the determination unit 11 determines whether or not the skin conductance detected by the steering sweat sensor 24 and corresponding to the degree of sweating of the driver's palm (sweating water amount) is greater than or equal to a predetermined value. Execute the judgment.

  As a result of the determination in step S12, when palm sweating is detected (step S12: Yes), the process proceeds to step S13, and the determination unit 11 determines the own vehicle based on the signals supplied from the front camera 21 and the illuminance sensor 22. It is determined whether or not the reflecting plate 70 exists outside the roadway such as a roadside belt or a road shoulder ahead. For example, the determination unit 11 includes an image corresponding to the reflection plate 70 in the image taken by the front camera 21 based on the position (stored in advance) where the reflection plate 70 specified by the law is installed. And whether or not the illuminance detected by the illuminance sensor 22 includes the light corresponding to the reflected light from the reflecting plate 70 is determined.

  If the reflection plate 70 is present as a result of the determination in step S13 (step S13: Yes), the process proceeds to step S14. Thus, in the situation that has proceeded to step S14, it can be said that the driver is in a tense state, and the environmental situation in front of the host vehicle is a situation in which the driver is in a tense state. Therefore, the headlight control unit 12 of the control unit 10 performs control to lower the optical axis of the low beam LED 32 via the actuator, and moves the irradiation range by the low beam LED 32 downward (step S14). Specifically, the headlight control unit 12 is based on the height from the road surface of the reflecting plate 70 defined by laws and regulations, the result of analyzing the image of the front camera 21 and the illuminance of the illuminance sensor 22 in step S13. Then, control is performed to lower the optical axis of the low beam LED 32 by an appropriate angle such that the light from the low beam LED 32 is not irradiated onto the reflection plate 70.

  On the other hand, as a result of the determination in step S11, when the value obtained by subtracting the reference pupil diameter from the current pupil diameter is not equal to or larger than the predetermined value (step S11: No), and as a result of the determination in step S12, palm sweating is detected. If not (No at Step S12), the process is terminated. In this case, since it can be said that the driver is not in a tension state, that is, the tension degree of the driver is not so large, the headlight control unit 12 does not perform control for changing the irradiation mode by the low beam LED 32. If the result of determination in step S13 is that there is no reflector 70 (step S13: No), the process ends. In this case, since it can be said that the environmental situation in front of the host vehicle is not a situation in which the driver is in a tense state, the headlight control unit 12 does not perform control to change the irradiation mode by the low beam LED 32.

  On the other hand, the process proceeds to step S15 after the control in step S14. In steps S15 to S17, the same determination as in steps S11 to S13 described above is performed. As a result, when the value obtained by subtracting the reference pupil diameter from the current pupil diameter is not equal to or greater than the predetermined value (step S15: No), or when sweating of the palm is not detected (step S16: No), or the reflector 70 is When it does not exist (step S17: No), it progresses to step S18. In this case, the driver's tension state has been alleviated or the environmental situation ahead of the host vehicle is no longer in a situation where the driver is in a tension state, so the headlight control unit 12 is based on the optical axis of the low beam LED 32. Return control is performed (step S18). Specifically, the headlight control unit 12 performs control to raise the optical axis of the low beam LED 32 lowered in step S14 to the original angle before being lowered, and moves the irradiation range by the low beam LED 32 upward.

  On the other hand, the value obtained by subtracting the reference pupil diameter from the current pupil diameter is equal to or greater than a predetermined value (step S15: Yes), and sweating of the palm is detected (step S16: Yes), and the reflector 70 is present. If yes (step S17: Yes), the process returns to step S15. In this case, since the driver's tension state has not been eased and the environmental situation in front of the host vehicle is still in a situation where the driver is in a tension state, the headlight control unit 12 is lowered in step S14. The optical axis of the low beam LED 32 is maintained, that is, the current irradiation range by the low beam LED 32 is maintained.

  In the headlight control process shown in FIG. 7, the value obtained by subtracting the reference pupil diameter from the current pupil diameter is equal to or greater than a predetermined value (step S11: Yes), and palm sweating is detected (step S12: Yes). In addition, when the reflector 70 is present (step S13: Yes), control is performed to lower the optical axis of the low beam LED 32 (step S14). In another example, the presence or absence of the reflector 70 is determined. Regardless, if the value obtained by subtracting the reference pupil diameter from the current pupil diameter is equal to or greater than a predetermined value and palm sweating is detected, control to lower the optical axis of the low beam LED 32 may be performed. That is, when the LED headlight 30 is used when it is determined that the driver is in a tension state regardless of whether or not the environmental situation in front of the host vehicle is a situation in which the driver is in a tension state. You may perform control for relieving the tension state of the driver who arises.

[Function and effect]
Next, functions and effects of the headlight control apparatus according to the embodiment of the present invention will be described.

  According to the present embodiment, when the value obtained by subtracting the reference pupil diameter from the current pupil diameter is equal to or larger than a predetermined value, palm sweating is detected, and the reflector 70 is present, the driver is in a tension state. It is determined that the environment condition in front of the host vehicle is a situation in which the driver is in a tension state, and control is performed to lower the optical axis of the low beam LED 32 so that the irradiation range by the low beam LED 32 is moved downward. Therefore, the light from the low beam LED 32 is not irradiated to the reflecting plate 70, and the reflected light from the reflecting plate 70 is not generated. As a result, the reflected light from the reflecting plate 70 does not enter the driver's eyes, and the driver's tension caused by the use of the LED headlight 30 can be moderated properly, in other words, the driver can be rested. be able to.

  Further, in this embodiment, since the determination is made using both the pupil diameter of the driver and the sweating of the palm, the tension state of the driver is compared with the case where the determination is performed using only one of the pupil diameter and the sweating of the palm. Can be determined with high accuracy. Further, in the present embodiment, in addition to the determination of the driver's tension state, the environmental situation in front of the host vehicle is also determined. Specifically, the presence / absence of the reflector 70 in front of the host vehicle is determined. Only when the tension state of the LED headlight 30 is caused by the environmental situation, the irradiation mode of the LED headlight 30 can be changed. Therefore, the useless change of the illumination mode of the LED headlight 30 when the driver's tension state is not caused by the environmental situation can be suppressed.

[Modification]
In the above-described embodiment, control is performed to lower the optical axis of the low beam LED 32 so that the light of the LED headlight 30 is not irradiated to the reflector 70, and the irradiation range by the low beam LED 32 is moved downward. This control corresponds to control for reducing the irradiation range of the LED headlight 30 in the height direction. In another example, instead of reducing the irradiation range of the LED headlight 30 in the height direction, control is performed to reduce the irradiation range of the LED headlight 30 in the width direction, and the light of the LED headlight 30 is reflected by the reflector 70. May not be irradiated. Specifically, in this example, the headlight control unit 12 performs control to reduce the irradiation range in the width direction by the high beam LED 31 of the LED headlight 30.

  Here, with reference to FIG. 8, an example of a control method by the headlight control unit 12 in another example of the embodiment of the present invention described above will be described. FIG. 8 shows a view of the irradiation range of the high beam LED 31 from above (references R1 to R4 and L1 to L4 are the same as those in FIGS. 2B to 2D).

  The left side of FIG. 8 shows an irradiation range by the high beam LED 31 when the control by the headlight control unit 12 in another example of the present embodiment is not performed. In this case, all of the first high beam LED 31a, the second high beam LED 31b, the third high beam LED 31c, and the fourth high beam LED 31d are turned on for both the right and left high beam LEDs 31. Therefore, the light from the high beam LED 31 is applied to the reflection plate 70, specifically, the light from the left first high beam LED 31a and the second high beam LED 31b is applied to the reflection plate 70, and the reflected light from the reflection plate 70 is generated. It will be.

  On the other hand, the right side of FIG. 8 shows an irradiation range by the high beam LED 31 when the control by the headlight control unit 12 in another example of the present embodiment is performed. In this case, the headlight control unit 12 turns off the first high beam LED 31a and the second high beam LED 31b for the left high beam LED 31 and reduces the third high beam LED 31c and the fourth high beam to reduce the irradiation range in the width direction of the high beam LED 31. Only the LED 31d is turned on. By doing so, the light from the high beam LED 31 is not irradiated to the reflecting plate 70, and the reflected light from the reflecting plate 70 is not generated. Therefore, the reflected light from the reflecting plate 70 does not enter the driver's eyes, and the driver's tension caused by the use of the LED headlight 30 can be moderated appropriately.

  Further, in the above-described embodiment and other examples, control is performed to reduce the irradiation range of the LED headlight 30 in the height direction or the width direction so that the light from the LED headlight 30 is not irradiated onto the reflection plate 70. However, in yet another example, control is performed to reduce the illuminance of the portion of the light from the LED headlight 30 that irradiates the reflector 70, and the illuminance of the reflected light from the reflector 70 is reduced. You may make it make it. Specifically, in this example, since the reflecting plate 70 is positioned in a region corresponding to the end portion in the width direction of the irradiation range by the LED headlight 30, in principle, the headlight control unit 12 determines the irradiation range of the LED headlight 30. Control is performed to reduce the illuminance at the end in the width direction. For example, the headlight control unit 12 controls to reduce the illuminance (light amount) of the first high beam LED 31a and the second high beam LED 31b (only the first high beam LED 31a) of the high beam LED 31 that constitutes the light that irradiates the end in the width direction. I do. When such control is performed, the illuminance of the reflected light from the reflecting plate 70 due to the light of the high beam LED 31 is reduced, so that the driver's tension caused by the use of the LED headlight 30 can be moderated appropriately. it can. Moreover, according to this other example, since the irradiation range by the LED headlight 30 is not reduced, the wide irradiation range of the LED headlight 30 can be maintained.

DESCRIPTION OF SYMBOLS 10 Control part 11 Judgment part 12 Headlight control part 21 Front camera 22 Illuminance sensor 23 Driver monitoring camera 24 Steering sweat sensor 25 Vehicle speed sensor 30 LED headlight 31 High beam LED
31a First high beam LED
31b Second high beam LED
31c 3rd high beam LED
31d 4th high beam LED
32 Low beam LED
70 reflector 100 headlight control system

Claims (4)

A headlight control device for controlling an LED headlight configured to vary the illuminance according to the irradiation range and irradiation position,
Pupil diameter detection means for detecting the pupil diameter of the driver;
Sweat detection means for detecting driver's palm sweat;
When the difference between the pupil diameter detected by the pupil diameter detection means and the reference pupil diameter is equal to or larger than a predetermined value and palm sweating is detected by the sweat detection means, the width in the irradiation range by the LED headlight Headlight control means for controlling the illumination range and / or illuminance of the LED headlight so as to reduce the illuminance at the direction end,
A headlight control device comprising:   2. The headlight control according to claim 1, wherein the headlight control unit performs control to reduce an irradiation range of the LED headlight to reduce an illuminance at an end in a width direction in the irradiation range of the LED headlight. apparatus.   The headlight control means performs control to change the optical axis of the LED headlight so that the irradiation range by the LED headlight is moved downward, and thereby sets the irradiation range in the height direction by the LED headlight. The headlight control device according to claim 1, wherein the headlight control device is reduced. It further includes a reflector detection means for detecting a reflector present in front of the host vehicle,
In the headlight control means, the difference between the pupil diameter detected by the pupil diameter detection means and the reference pupil diameter is not less than the predetermined value, and palm sweating is detected by the sweat detection means, and The irradiation range and / or the illuminance of the LED headlight is controlled so that the illuminance at the end in the width direction in the irradiation range of the LED headlight is reduced when the reflection plate is detected by the reflection plate detection means. Item 4. The headlight control device according to any one of Items 1 to 3.

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