Headlight control device

Abstract

To suppress a sense of confusion or trouble to an occupant when an amount of change of a steering angle of an own vehicle is a specified value or more.SOLUTION: A controller 18 of a headlight control device 10 controls an irradiation range of auxiliary headlights 26L, 26R of an own vehicle based on a steering angle of the own vehicle. The controller 18 makes, when an amount of change of the steering angle of the own vehicle is more than a specified value, an irradiation light amount of the auxiliary headlights 26L, 26R be smaller, the auxiliary headlights 26L, 26R be turned off, or the irradiation range of the auxiliary head lights 26L, 26R be enlarged relative to a case that the amount of change of the steering angle of the own vehicle is the specified value or less.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a headlamp control device. [Background technology]

[0002] Patent document 1 describes a method of calculating the destination point of the vehicle after a predetermined time has elapsed based on the vehicle speed and steering angle, and controlling the headlight illumination direction so that the calculated destination point is within the illumination range of the vehicle's headlights. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2003-072460 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the technology for controlling the illumination range from the headlights according to the steering angle of the vehicle, including the technology described in Patent Document 1, when the change in the steering angle of the vehicle is equal to or greater than a predetermined value, such as when the vehicle approaches a curve, a control delay in the illumination range occurs in response to a change in the line of sight of the occupant. In this case, the control delay in the illumination range causes a delay in the movement of the illumination range in response to a change in the line of sight of the occupant, which may confuse or annoy the occupant. The control delay in the illumination range also occurs when turning the steering wheel at the exit of a curve or in the middle of an S-shaped curve, in addition to the entrance of the curve described above.

[0005] The present disclosure has been made in consideration of the above-mentioned facts, and aims to obtain a headlight control device that can suppress confusion and annoyance caused to occupants when the change in steering angle of the vehicle becomes greater than a predetermined value. [Means for solving the problem]

[0006] A headlight control device according to a first aspect includes a control unit that controls the illumination range from the headlights of the host vehicle based on the steering angle of the host vehicle, and when a change in the steering angle of the host vehicle is greater than a predetermined value, reduces the amount of light illuminated from the headlights, turns off the headlights, or expands the illumination range from the headlights compared to when the change in the steering angle of the host vehicle is equal to or less than the predetermined value.

[0007] In the first aspect, the control unit controls the illumination range from the headlights of the vehicle based on the steering angle of the vehicle. When the change in the steering angle of the vehicle is greater than a predetermined value, the control unit reduces the amount of light emitted from the headlights, turns off the headlights, or expands the illumination range from the headlights, compared to when the change in the steering angle is equal to or less than the predetermined value. This makes it difficult for the occupant to perceive a control delay in the illumination range from the headlights that occurs when the change in the steering angle of the vehicle is equal to or greater than the predetermined value, thereby preventing the occupant from feeling confused or annoyed.

[0008] In a second aspect, in the first aspect, when a change in the steering angle is less than or equal to the predetermined value, the control unit controls the illumination range from the headlight to form an illumination pattern on a road surface that is curved in accordance with the steering angle.

[0009] In the second mode, when the change in the steering angle of the vehicle is equal to or less than a predetermined value, the illumination range from the headlights is controlled so as to form an illumination pattern on the road surface that is curved according to the steering angle of the vehicle. This makes it possible to accurately illuminate the road on which the vehicle is about to travel from the illumination pattern that is curved according to the steering angle of the vehicle when the change in the steering angle of the vehicle is equal to or less than a predetermined value.

[0010] In a third aspect, in the second aspect, the irradiation pattern is an elongated pattern having a width corresponding to a vehicle width of the host vehicle.

[0011] In the third aspect, the illumination pattern on the road surface is an elongated pattern with a width corresponding to the vehicle width of the vehicle, so that when there is a narrow spot on the route along which the vehicle is about to travel, the occupant can recognize whether or not the vehicle can pass through the narrow spot. Effect of the Invention

[0012] The present disclosure has an effect of suppressing confusion and annoyance felt by occupants when the amount of change in the steering angle of the vehicle becomes equal to or greater than a predetermined value. [Brief description of the drawings]

[0013] [Figure 1] 1 is a block diagram showing a schematic configuration of a vehicle headlamp system according to an embodiment; [Diagram 2] FIG. 2 is a schematic diagram showing an example of the configuration of an auxiliary headlamp. [Diagram 3] FIG. 4 is a schematic diagram showing an example of an irradiation pattern. [Figure 4] 5 is a flowchart showing the contents of an auxiliary headlamp control process. [Diagram 5] 6A to 6C are schematic diagrams showing an example of a transition of an amount of irradiated light and an irradiation pattern by an auxiliary headlamp control process. [Figure 6] 11 is a schematic diagram showing that the movement of the irradiation range is delayed due to a control delay of the irradiation range. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] An example of an embodiment of the present disclosure will be described in detail below with reference to the drawings. A vehicle headlamp system 10 shown in Fig. 1 is mounted on a vehicle (host vehicle) and includes a light switch 12, a steering angle sensor 14, a headlamp control ECU (Electronic Control Unit) 16, a pair of left and right headlamp 24L, 24R, and a pair of left and right auxiliary headlamp 26L, 26R.

[0015] In addition, the headlight control ECU 16 of the vehicle headlight system 10 is an example of a headlight control device according to the present disclosure, and the auxiliary headlights 26L and 26R are an example of a headlight in the present disclosure. An example of the vehicle on which the vehicle headlight system 10 is mounted is an emergency vehicle such as an ambulance, a fire engine, or a police vehicle.

[0016] The light switch 12 is connected to the headlamp control ECU 16 via a communication line such as a CAN (Controller Area Network) bus. The light switch 12 is provided with a plurality of contacts including a first contact for instructing the vehicle headlamp 24L, 24R to be turned on and a second contact for instructing the vehicle headlamp 24L, 24R to be turned off. When the light switch 12 is operated by an occupant of the vehicle, any of the plurality of contacts is turned on, and the light switch 12 outputs switch contact information indicating which contact is turned on to the headlamp control ECU 16.

[0017] The steering angle sensor 14 detects the steering angle of the host vehicle. The steering angle sensor 14 is connected to the headlamp control ECU 16 via a communication line (for example, a CAN bus) and outputs the steering angle of the host vehicle to the headlamp control ECU 16.

[0018] The headlights 24L and 24R are headlights that have a constant light distribution pattern and illuminate a constant range in front of the vehicle. The light source of the headlights 24L and 24R may be any of an LED (Light Emitting Diode), an HID (High Intensity Discharge), and a halogen bulb.

[0019] On the other hand, the auxiliary headlights 26L and 26R are auxiliary lights that emit light toward the road surface and can change the light irradiation pattern on the road surface. The auxiliary headlights 26L and 26R can adopt a configuration including an LED array 28 in which a plurality of LED chips 27 are arranged in a matrix and a lens 30 arranged on the light emission side of the LED array 28, as shown in FIG. 2(A) as a micro LED system. In this configuration (micro LED system), the light emitted from each LED chip 27 is arranged in a matrix on the road surface, and the irradiation pattern on the road surface can be changed to any pattern by controlling the turning on and off of each LED chip 27.

[0020] In this embodiment, a plurality of illumination patterns on the road surface by the auxiliary headlights 26L and 26R are determined as shown in FIG. 3. That is, the plurality of illumination patterns include an elongated (rectangular) pattern with a width corresponding to the vehicle width of the vehicle (see "illumination pattern when going straight" in FIG. 3) corresponding to the state in which the vehicle is going straight with a steering angle of 0. In addition, in a state in which the steering wheel is rotated counterclockwise and the vehicle is turning left, a plurality of elongated patterns with different curvatures according to different steering angles are prepared with a width corresponding to the vehicle width of the vehicle (see "illumination pattern when turning left" in FIG. 3). In addition, in a state in which the steering wheel is rotated clockwise and the vehicle is turning right, a plurality of elongated patterns with different curvatures according to different steering angles are prepared with a width corresponding to the vehicle width of the vehicle (see "illumination pattern when turning right" in FIG. 3).

[0021] The headlamp control ECU 16 includes a CPU (Central Processing Unit), memories such as a ROM (Read Only Memory) and a RAM (Random Access Memory), a non-volatile storage unit 20 such as a HDD (Hard Disk Drive) and an SSD (Solid State Drive), and a communication I / F (Interface). The storage unit 20 stores a program (not shown) for causing the CPU of the headlamp control ECU 16 to function as the control unit 18, and irradiation pattern control information 22. The irradiation pattern control information 22 is information that defines a control pattern for turning on and off the individual LED chips 27 for each irradiation pattern so that the irradiation pattern on the road surface by the auxiliary headlamp 26L, 26R becomes one of the above-mentioned multiple irradiation patterns.

[0022] The control unit 18 turns on the headlights 24L, 24R when a first contact of the light switch 12 is on based on switch contact information input from the light switch 12. The headlight control ECU 16 turns off the headlights 24L, 24R when a second contact of the light switch 12 is on. The control unit 18 may turn on the headlights 24L, 24R when the illuminance around the vehicle falls below a threshold value.

[0023] Further, for example, while the headlights 24L, 24R are turned on, the control unit 18 also turns on the auxiliary headlights 26L, 26R. When turning on the auxiliary headlights 26L, 26R, the control unit 18 acquires the steering angle of the vehicle from the steering angle sensor 14, and controls the illumination range from the auxiliary headlights 26L, 26R to be an illumination pattern corresponding to the acquired steering angle of the vehicle. However, when the amount of change in the steering angle of the vehicle is greater than a predetermined value, the control unit 18 reduces the amount of illumination from the auxiliary headlights 26L, 26R compared to when the amount of change in the steering angle of the vehicle is equal to or smaller than the predetermined value.

[0024] Next, as an operation of this embodiment, an auxiliary headlamp control process executed by the control unit 18 (CPU of the headlamp control ECU 16) while the ignition switch of the host vehicle is on will be described with reference to FIG.

[0025] In step 50 of the auxiliary headlight control process, the control unit 18 determines whether or not the lighting conditions for the auxiliary headlights 26L and 26R are satisfied. In the determination in step 50, for example, when the headlights 24L and 24R are turned on, it can be determined that the lighting conditions for the auxiliary headlights 26L and 26R are satisfied. In addition, for example, when the illuminance around the vehicle becomes less than a threshold value, it can be determined that the lighting conditions for the auxiliary headlights 26L and 26R are satisfied. Furthermore, for example, it is also possible to determine that the lighting conditions for the auxiliary headlights 26L and 26R are satisfied when a switch for instructing turning on and off the auxiliary headlights 26 is provided and a predetermined contact for instructing turning on the auxiliary headlights 26 is turned on in the switch.

[0026] If the determination in step 50 is negative, the process proceeds to step 52. In step 52, the control unit 18 turns off the auxiliary headlights 26L, 26R. After the process of step 52 is completed, the process returns to step 50, and steps 50 and 52 are repeated until the determination in step 50 is positive. If the conditions for turning on the auxiliary headlights 26L, 26R are met, the determination in step 50 is positive, and the process proceeds to step 54.

[0027] In step 54, the control unit 18 acquires the steering angle of the host vehicle from the steering angle sensor 14. In step 56, the control unit 18 selects an irradiation pattern corresponding to the direction and magnitude of the steering angle of the host vehicle acquired in step 54 as the irradiation range (irradiation pattern on the road surface) from the auxiliary headlights 26L, 26R. Then, the control unit 18 reads out the irradiation pattern control information 22 corresponding to the selected irradiation pattern.

[0028] In step 58, the control unit 18 again acquires the steering angle of the host vehicle from the steering angle sensor 14, and calculates the amount of change in the steering angle of the host vehicle from the steering angles of the host vehicle acquired in steps 54 and 58. In step 60, the control unit 18 determines whether or not the amount of change in the steering angle (the absolute value of the amount of change) calculated in step 58 is greater than a predetermined value. If the determination in step 60 is negative, the process proceeds to step 62.

[0029] In step 62, the control unit 18 judges whether or not the "state in which the amount of change in the steering angle is equal to or less than a predetermined value" continues for a predetermined time or more. If the judgment in step 62 is positive, the process proceeds to step 64. Then, in step 64, the control unit 18 sets the amount of light irradiated from the auxiliary headlights 26L, 26R to a normal amount of light. On the other hand, if the judgment in step 60 is positive or the judgment in step 62 is negative, the process proceeds to step 66. In step 66, the control unit 18 sets the amount of light irradiated from the auxiliary headlights 26L, 26R to a value that is less bright than the normal amount of light.

[0030] After the processing of step 64 or step 66 is performed, the process proceeds to step 68. In step 68, the control unit 18 turns on the auxiliary headlights 26L, 26R in the irradiation pattern selected in step 56 and with the light amount set in step 64 or step 66, based on the irradiation pattern control information 22 read out in step 56. After the processing of step 68 is performed, the process returns to step 50, and the processing from step 50 onwards is repeated.

[0031] By the above-described auxiliary headlight control process, as shown in Fig. 5(A), when the vehicle is traveling on a straight road, the auxiliary headlights 26L, 26R are controlled to emit a normal amount of light. Also, the illumination range of the auxiliary headlights 26L, 26R is controlled according to the steering angle (=0) of the vehicle so that the illumination pattern on the road surface is an elongated (rectangular) pattern with a width corresponding to the vehicle width of the vehicle.

[0032] Also, when the vehicle approaches a left curve, as shown in FIG. 5(B), the illumination range of the auxiliary headlights 26L, 26R is controlled so that the illumination pattern on the road surface is an elongated pattern that curves to the left in accordance with the steering angle of the vehicle with a width corresponding to the vehicle width of the vehicle. However, at this time, the change in the steering angle of the vehicle becomes equal to or greater than a predetermined value, so that a control delay in the illumination range (illumination pattern) occurs in response to a change in the line of sight of the occupant, as shown in FIG. 5(B) and FIG. 6. In contrast, when the change in the steering angle of the vehicle becomes equal to or greater than a predetermined value, the illumination amount of the auxiliary headlights 26L, 26R is reduced from the normal amount of light, so that the above-mentioned control delay is less noticeable to the occupant, and confusion and annoyance to the occupant are suppressed.

[0033] In addition, when the vehicle is turning a curve at a constant steering angle, the control delay of the illumination range (illumination pattern) in response to the change in the line of sight of the occupant is eliminated, as shown in Fig. 5(C). In addition, the change in the steering angle of the vehicle becomes less than a predetermined value, and the illumination light amount of the auxiliary headlights 26L, 26R is restored to the normal light amount, so that the road on which the vehicle is about to travel can be accurately illuminated.

[0034] In this manner, in this embodiment, the control unit 18 of the vehicle headlamp system 10 controls the illumination range from the auxiliary headlamp 26L, 26R of the vehicle based on the steering angle of the vehicle. When the change in the steering angle of the vehicle is greater than a predetermined value, the control unit 18 reduces the amount of illumination from the auxiliary headlamp 26L, 26R compared to when the change in the steering angle of the vehicle is equal to or less than the predetermined value. This makes it difficult for the occupant to perceive a delay in the control of the illumination range from the auxiliary headlamp 26L, 26R, which occurs when the change in the steering angle of the vehicle is equal to or greater than the predetermined value, and thus makes it possible to suppress confusion and annoyance for the occupant.

[0035] In this embodiment, the control unit 18 controls the illumination range from the auxiliary headlights 26L, 26R to have an illumination pattern curved on the road surface according to the steering angle of the vehicle when the change in the steering angle of the vehicle is equal to or less than a predetermined value. This allows the road on which the vehicle is about to travel to be accurately illuminated from the illumination pattern curved according to the steering angle of the vehicle when the change in the steering angle of the vehicle is equal to or less than a predetermined value.

[0036] In addition, in this embodiment, the illumination pattern on the road surface is an elongated pattern with a width corresponding to the vehicle width of the vehicle. This allows the occupant to recognize whether the vehicle can pass through a narrow place when there is a narrow place on the route on which the vehicle is about to travel. In detail, when an emergency vehicle equipped with the vehicle headlamp system 10 is running in an emergency by weaving through a gap between other vehicles parked on the road, which is an example of the narrow place, the occupant can recognize whether the vehicle can pass through the gap between the other vehicles. This allows the emergency vehicle to be supported in running smoothly.

[0037] In the above embodiment, an emergency vehicle has been described as an example of a vehicle equipped with the vehicle headlight system 10, but the present disclosure is not limited thereto, and the headlight control device according to the present disclosure may be installed in a vehicle other than an emergency vehicle.

[0038] In the above embodiment, the amount of light emitted from the auxiliary headlights 26L and 26R is reduced when the change in the steering angle of the vehicle is greater than a predetermined value, compared to when the change in the steering angle of the vehicle is equal to or less than the predetermined value. However, the present disclosure is not limited to this. For example, when the change in the steering angle of the vehicle is greater than a predetermined value, the auxiliary headlights 26L and 26R may be turned off or the illumination range from the auxiliary headlights 26L and 26R may be expanded compared to when the change in the steering angle of the vehicle is equal to the predetermined value. In these cases, the control delay in the illumination range from the auxiliary headlights 26L and 26R is less noticeable to the occupant, and confusion and annoyance to the occupant can be suppressed. The illumination range when the illumination range is expanded may be, for example, a range equivalent to the low beam of the headlights 24L and 24R.

[0039] In addition, in the above embodiment, the micro LED system shown in FIG. 2(A) has been described as the configuration of the auxiliary headlights 26L, 26R that can change the illumination pattern on the road surface, but the present disclosure is not limited to the micro LED system.

[0040] For example, in the DMD (Digital Mirror Device) method shown in FIG. 2B, the DMD 34 and the lens 30 are arranged in this order on the light emission side of the LED light source 32. The DMD 34 has a plurality of micromirrors 36 whose angles can be changed arranged in a matrix, and each micromirror 36 is controlled to a first angle that reflects incident light into the lens 30, or a second angle that reflects incident light out of the lens 30. When the DMD method is adopted for the auxiliary headlights 26L and 26R, the light reflected by each micromirror 36 of the DMD 34 is arranged in a matrix on the road surface while each micromirror 36 is controlled to a first angle. Therefore, by controlling the angle of each micromirror 36 to a first angle or a second angle, it is possible to change the illumination pattern on the road surface to any pattern.

[0041] Also, for example, in the laser scanning method shown in FIG. 2(C), a MEMS (Micro Electro Mechanical System) mirror 40, a phosphor 42, and a lens 30 are arranged in this order on the light emission side of the blue laser light source 38. The angle of the MEMS mirror 40 is controlled so that the laser light incident on the mirror is scanned two-dimensionally. The phosphor 42 converts the wavelength of the incident scanning laser light. When the laser scanning method is adopted for the auxiliary headlights 26L and 26R, the laser light reflected by the MEMS mirror 40 and passing through the phosphor 42 and the lens 30 in this order scans the road surface two-dimensionally. Therefore, it is possible to change the irradiation pattern on the road surface to any pattern by controlling the turning on and off of the blue laser light source 38 at the timing when the laser light scans each position on the road surface.

[0042] 2(D), for example, a liquid crystal panel 48 having a liquid crystal layer 44 sandwiched between a pair of polarizing plates 46 on the front and rear sides, and a lens 30 are arranged in this order on the light emission side of an LED array 28 having a plurality of LED chips 27 arranged in a matrix. When a liquid crystal system is adopted for the auxiliary headlights 26L, 26R, light transmitted through each liquid crystal cell of the liquid crystal panel 48 is arranged in a matrix on the road surface, and by controlling the light transmittance of each liquid crystal cell of the liquid crystal panel 48, it is possible to change the illumination pattern on the road surface to any pattern. [Explanation of symbols]

[0043] 10. Vehicle headlamp system 14 Steering angle sensor 16 Headlight control ECU (headlight control device) 18 Control Unit 26L, 26R Auxiliary headlight

Claims

1. A headlight control device including a control unit that controls an illumination range from the headlights of a vehicle based on a steering angle of the vehicle, and when a change in the steering angle of the vehicle is greater than a predetermined value, reduces the amount of light illuminated from the headlights, turns off the headlights, or expands the illumination range from the headlights compared to when the change in the steering angle of the vehicle is equal to or less than the predetermined value.

2. 2. The headlamp control device according to claim 1, wherein the control unit controls the illumination range from the headlamp to have an illumination pattern on a road surface that is curved in accordance with the steering angle when the change amount of the steering angle is equal to or less than the predetermined value.

3. The headlamp control device according to claim 2 , wherein the illumination pattern is an elongated pattern having a width corresponding to a vehicle width of the host vehicle.

Images