Vehicle headlamp control device, vehicle headlamp control method, and vehicle headlamp system

Abstract

To provide a control device of a vehicular headlight which can adjust an optical axis according to the state of a vehicle.SOLUTION: A control device of a vehicular headlight comprises: a vehicle state specification unit 12 which specifies a state of a vehicle; and an optical axis adjustment unit 23 which adjusts an optical axis of irradiation light by receiving a specification result by the vehicle state specification unit 12. The vehicle state specification unit 12 performs processing of setting a reference value about acceleration to a first value when the vehicle is an engine vehicle and setting the reference value to a second value smaller than the first value when the vehicle is a vehicle other than the engine vehicle, specifying the state of the vehicle as the vehicle stop state when an absolute value of acceleration detected by using an acceleration sensor 21 is smaller than the reference value, and specifying the state of the vehicle as the non-vehicle stop state when the absolute value of the acceleration is equal to or greater than the reference value as the first processing.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a technique for controlling a vehicle headlamp. [Background technology]

[0002] Japanese Patent Laid-Open Publication No. 2013-71477 (Patent Document 1) describes a control device for a vehicle lamp that, when a signal output from a passenger compartment door sensor or a trunk door sensor is received while the vehicle is stopped, generates and outputs an adjustment signal that instructs the vehicle lamp to adjust the optical axis using the output value of an inclination sensor, and when the vehicle is moving, controls to avoid outputting an adjustment signal or to generate and output a maintenance signal that instructs the vehicle lamp to maintain the optical axis position. In this control device, the detection value of a vehicle speed sensor is used to determine whether the vehicle is stopped or moving.

[0003] Generally, vehicle speed sensors generate 10 or fewer pulse signals (for example, 2 to 8 pulses) per axle revolution. Therefore, when the vehicle is creeping or otherwise traveling at extremely low speeds (for example, 5 km / h or less), it takes some time for a pulse signal to be generated after the vehicle starts moving. During this time, the optical axis may be adjusted accordingly while the vehicle is stopped, which may result in an inappropriate optical axis. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-71477 Summary of the Invention [Problem to be solved by the invention]

[0005] One of the objects of a specific aspect of the present disclosure is to perform optical axis adjustment according to the state of the vehicle. [Means for solving the problem]

[0006] [1] A control device for a vehicle headlamp according to one aspect of the present disclosure is a control device for a vehicle headlamp, which includes: (a) a device for controlling the optical axis of light emitted by the vehicle's headlamp; (b) an acceleration sensor mounted on the vehicle; (c) an identification unit that identifies whether the vehicle is in a stopped state or a non-stopped state; and (d) an optical axis adjustment unit that adjusts the optical axis of the emitted light by control corresponding to each of the cases where the vehicle is in the stopped state and the non-stopped state based on the identification result by the identification unit; and (e) the identification unit performs, as a first process, a process of setting a reference value related to acceleration to a first value if the vehicle is an engine vehicle, and setting the reference value to a second value smaller than the first value if the vehicle is not an engine vehicle, and determining that the vehicle is in the stopped state if the absolute value of the acceleration detected using the acceleration sensor is smaller than the reference value, and determining that the vehicle is in the non-stopped state if the absolute value of the acceleration is equal to or greater than the reference value. [2] A control method for vehicle headlights according to one aspect of the present disclosure is a method for controlling the optical axis of light emitted by the vehicle headlights, the method including: (a) determining whether the vehicle is in a stopped state or a non-stop state; and (b) adjusting the optical axis of the emitted light by control corresponding to each of the cases where the vehicle is in the stopped state and the non-stop state based on the determination result of (a), wherein (a) is a first process that sets a reference value related to acceleration to a first value if the vehicle is an engine vehicle, and sets the reference value to a second value smaller than the first value if the vehicle is not an engine vehicle, and determines that the vehicle is in the stopped state if the absolute value of the acceleration detected using the acceleration sensor is smaller than the reference value, and determines that the vehicle is in the non-stop state if the absolute value of the acceleration is equal to or greater than the reference value. [3] A vehicle headlamp system according to one aspect of the present disclosure is a vehicle headlamp system including the control device according to [1] above and a headlamp whose optical axis is controlled by the control device.

[0007] According to the above-described configuration, the optical axis is adjusted in accordance with the state of the vehicle. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a block diagram showing the configuration of a vehicle headlamp system according to an embodiment. [Figure 2] FIG. 2 is a diagram showing an example of the configuration of a computer system that realizes a vehicle control ECU. [Figure 3] FIG. 3 is a diagram schematically illustrating the configuration and operation of the headlamp unit. [Figure 4] FIG. 4 is a diagram illustrating a configuration example of a wheel speed sensor. [Figure 5] 5(A) and 5(B) are waveform diagrams showing examples of detection signals output from the Hall elements of the wheel speed sensors. [Figure 6] FIG. 6 is a flowchart showing the operation procedure of the vehicle headlamp system. [Figure 7] FIG. 7 is a flowchart showing the detailed operation procedure of step S11 shown in FIG. [Figure 8] FIG. 8 is a flowchart showing the detailed operation procedure of step S13 shown in FIG. [Figure 9] FIG. 9 is a flowchart showing the detailed operation procedure of step S15 shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] 1 is a block diagram showing the configuration of a vehicle headlamp system according to one embodiment. The illustrated vehicle headlamp system includes a controller 10, a pair of headlamp units 30L and 30R, a vehicle speed sensor 40, a wheel speed sensor 41, a drive shaft rotation detection sensor 42, and a propeller shaft rotation detection sensor 43.

[0010] The controller 10 controls the on / off and optical axis control (leveling) of the headlamp units 30L and 30R. The controller 10 is realized by using a computer system having, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), etc., and executing a predetermined operating program on the computer system. The controller 10 of this embodiment has, as functional blocks realized by the CPU executing the operating program, an in-vehicle information acquisition unit 11, a vehicle state identification unit (identification unit) 12, an angle calculation unit 22, and an optical axis adjustment unit 23. The controller 10 of this embodiment also has a built-in acceleration sensor 21.

[0011] The headlamp units 30L, 30R are installed at predetermined positions on the left and right sides of the front of the vehicle to irradiate light ahead of the vehicle. Each of the headlamp units 30L, 30R in this embodiment includes a light source 31 and a leveling actuator 32. The headlamp units 30L, 30R are connected to a controller 10, which controls the on / off operation of the light source 31 and the operation of the leveling actuator 32 to adjust the optical axis of the light emitted from the light source 31.

[0012] The vehicle speed sensor 40 generates intermittent pulse signals (vehicle speed pulses) according to the rotation speed of the vehicle's axle (the axle on which the wheels are attached), and is connected to the controller 10. The vehicle speed sensor 40 generates several pulse signals per axle rotation, for example. For this reason, when the vehicle is moving at a very low speed of 5 km / h or less due to creeping or the like, it takes a relatively long time for the vehicle speed sensor 40 to generate a pulse signal.

[0013] The wheel speed sensor 41 detects the wheel speed, which is the rotational speed of a wheel attached to an axle of a vehicle, and is connected to the controller 10. The wheel speed sensor 41 of this embodiment may detect the rotational speed of the wheel indirectly by detecting the rotational speed of a part that rotates along with the wheel, such as an axle hub, a brake drum, or a drive shaft, or may detect the rotational speed directly from the wheel.

[0014] The drive shaft rotation detection sensor 42 detects the rotation speed of the vehicle's drive shaft and is connected to the controller 10. The drive shaft here is a device that transmits driving force generated by a power source such as an engine or a motor to the vehicle's wheels. Note that if the wheel speed sensor 41 detects the wheel speed based on the rotation speed of the drive shaft, the drive shaft rotation detection sensor 42 may be omitted.

[0015] Propeller shaft rotation detection sensor 43 detects the rotation speed of the vehicle's propeller shaft and is connected to controller 10. The propeller shaft here is a device that transmits driving force generated by a power source such as an engine or motor located at the front of the vehicle in, for example, a four-wheel drive vehicle or a rear-wheel drive vehicle, to a differential gear or the like at the rear of the vehicle. Note that in vehicles that do not have a propeller shaft, this propeller shaft rotation detection sensor 43 is omitted.

[0016] The in-vehicle information acquisition unit 10 of the controller 10 connects to a communication network (not shown) provided in the vehicle for data communication between multiple in-vehicle devices installed in the vehicle, and acquires various in-vehicle information (in-vehicle information data) 44 that can be transmitted and received over this communication network. The in-vehicle information 44 is configured to be able to be acquired appropriately from multiple in-vehicle devices installed in the vehicle. For example, various information about the vehicle (vehicle name, model, etc.) can be acquired from an electronic control system that controls the operation of the vehicle. Specific examples of the in-vehicle information used in this embodiment will be described later.

[0017] The vehicle state identification unit 12 of the controller 10 identifies whether the vehicle state is "stopped state" or "non-stopped state" using the pulse signal obtained from the vehicle speed sensor 40 and the wheel speed signal obtained from the wheel speed sensor 41. A specific identification method will be described later.

[0018] The acceleration sensor 21 of the controller 10 detects acceleration in each of three mutually orthogonal axes, and is installed in the vehicle so that the three axes correspond to the front-rear, left-right, and up-down directions of the vehicle, but is not limited to this. In this embodiment, the acceleration sensor 21 is built into the controller 10, but the acceleration sensor 21 may not be built into the controller 10 and may be attached externally.

[0019] An angle calculation unit 22 of the controller 10 calculates the attitude angle of the vehicle using the acceleration detected by the acceleration sensor 21. The attitude angle of the vehicle is the angle between the front-rear axis of the vehicle and the road surface (reference axis). The optical axis of the light emitted by the headlamp unit 30 is adjusted by the optical axis adjustment unit 23 in accordance with changes in this attitude angle.

[0020] The angle calculation unit 22 of this embodiment calculates the vehicle attitude angle when the vehicle is in a stopped state, but does not calculate the vehicle attitude angle when the vehicle is not stopped. As a method for calculating the vehicle attitude angle when the vehicle is in a stopped state, various known methods can be used, and there are no particular limitations. To give a simple example, if the acceleration corresponding to the vehicle's longitudinal direction obtained using the acceleration sensor 21 is Xa and the acceleration corresponding to the vehicle's vertical direction is Ya, the vehicle attitude angle θ is calculated as follows: θ=tan -1 (Xa / Ya). The attitude angle may also be calculated when the vehicle is not stopped. In this case, various known methods may be used for the calculation method, and there are no particular limitations.

[0021] The optical axis adjustment unit 23 of the controller 10 adjusts the optical axes of the lights emitted by the headlamp units 30L, 30R based on the attitude angle of the vehicle calculated by the angle calculation unit 22. Specifically, the optical axis adjustment unit 23 generates control signals for operating the leveling actuators 32 of the headlamp units 30L, 30R.

[0022] The light source 31 of the headlamp units 30L, 30R generates light by receiving power from a power source (not shown). The light source 31 may be any light source that can generate light, and may be, for example, a halogen lamp, a high-pressure mercury lamp, a metal halide lamp, a high-pressure sodium lamp, or a semiconductor light-emitting element such as an LED.

[0023] The leveling actuator 32 of the headlamp units 30L and 30R variably sets the orientation of the light source 31 to adjust the angle of the optical axis, which is the main direction of travel of the light from the light source 31, based on a control signal supplied from the optical axis adjustment unit 23.

[0024] FIG. 2 is a diagram illustrating an example of the configuration of a computer system that realizes a vehicle control ECU. The illustrated computer system includes a CPU 201, a ROM 202, a RAM 203, a storage device 204, an external interface (I / F) 205, and an acceleration sensor 207, all of which are interconnected to enable communication. The CPU 201 operates based on a basic control program read from the ROM 202 and reads and executes a program (application program) 206 stored in the storage device 204. This enables the functions of the in-vehicle information acquisition unit 10, the vehicle state identification unit 12, the angle calculation unit 22, the optical axis adjustment unit 23, and the like. The RAM 203 temporarily stores data used during operation of the CPU 201. The storage device 204 is a non-volatile data storage device, such as a hard disk or a solid-state drive (SSD), and stores various data, including the program 206. The external interface 205 is an interface that connects the CPU 201 to external devices. In this embodiment, the external interface 205 is used to connect the CPU 201 to the vehicle speed sensor 40, the wheel speed sensor 41, and the like. The acceleration sensor 207 corresponds to the acceleration sensor 21 described above.

[0025] FIG. 3 is a diagram illustrating the configuration and operation of a headlamp unit. Each of the headlamp units 30L and 30R of this embodiment includes the light source 31 described above, a housing 33 that houses the light source 31, and a lens 34 that is disposed in front of the light source 31 (in the direction in which light is emitted) and fixed to the housing 33. The inner surface of the housing 33 is provided with a reflective surface that reflects light from the light source 31 forward. The actuator 32 is connected to the housing 33 that houses the light source 31 and changes the attitude of the housing 33. This allows the optical axis a of the light from the light source 31 to be variably set. For example, when the rear of the vehicle is relatively lowered, the optical axis a is controlled to point downward, and when the front of the vehicle is relatively lowered, the optical axis a is controlled to point upward. The degree to which the optical axis a points downward or upward is set according to the attitude angle of the vehicle. The optical axis a can also be referred to as the direction of light irradiation.

[0026] FIG. 4 is a diagram illustrating a schematic configuration example of a wheel speed sensor. The wheel speed sensor 41 of this embodiment includes a magnetic sensor rotor 50, a Hall element (detection element) 51, and a signal processing circuit 52. The magnetic sensor rotor 50 is made of, for example, magnetized rubber, and has north and south poles arranged alternately along the circumferential direction. The magnetic sensor rotor 50 is mounted on a part (rotating body) that rotates in conjunction with the rotation of the wheel, such as the axle hub. The smaller the installation range r of a pair of magnetic poles (one north pole and one adjacent south pole), the more preferable it is. This is because the smaller the installation range r, the more easily the wheel speed can be detected in response to slight wheel rotations. Specifically, the installation range r may be set to, for example, 1 / n of the circumference of the magnetic sensor rotor 50, where n can be at least a number greater than 4, and can also be a number greater than 8 or 16. The larger n, the earlier the wheel speed can be detected. The Hall element 51 detects changes in the magnetic field generated by the rotation of the magnetic sensor rotor 50, and is disposed with a predetermined gap between it and the surface of the magnetic sensor rotor 50. The signal processing circuit 52 is connected to the Hall element 51, and generates a wheel speed signal by performing predetermined signal processing on the detection signal of the Hall element 51. Note that the configuration shown in Fig. 4 is one example, and the configuration of the wheel speed sensor 41 is not limited to this.

[0027] 5(A) and 5(B) are waveform diagrams showing examples of detection signals output from the Hall element of the wheel speed sensor. In the wheel speed sensor 41 of this embodiment, the Hall element 51 outputs a sinusoidal detection signal that alternates between positive and negative in response to continuous changes in the magnetic field caused by the rotation of the magnetic sensor rotor 50. The detection signal waveform shown in FIG. 5(A) is the detection signal when the rotation speed is relatively slow, while the detection signal waveform shown in FIG. 5(B) is the detection signal when the rotation speed is relatively fast. The higher the rotation speed, the higher the frequency of the detection signal. In principle, this detection signal can be obtained even when the rotation speed of the magnetic sensor rotor 50 is extremely slow. This is because one cycle of signal is obtained each time the north and south poles facing the Hall element 51 are interchanged, and the north and south poles can be arranged alternately within a relatively narrow range. In the wheel speed sensor 41 of this embodiment, the detection signal from the Hall element 51 is appropriately amplified and shaped by the signal processing circuit 52 and then converted into a square wave signal. In this embodiment, this square wave signal is used as the wheel speed signal. Specifically, when a wheel speed signal in the form of a square wave signal is input to the controller 10, the controller 10 calculates the frequency of the square wave based on the wheel speed signal, and obtains the wheel speed based on the magnitude of this frequency. Note that the signal processing method shown here is an example and is not limited to this.

[0028] Fig. 6 is a flowchart showing the operation procedure of the vehicle headlamp system. Note that the order of the steps may be changed as appropriate, and other steps not shown may be added, as long as no contradictions or inconsistencies arise in the results of information processing (the same applies to the flowcharts shown in Figs. 7 to 9).

[0029] The vehicle state identification unit 12 performs a process based on the vehicle speed and wheel speed as one of the processes for identifying the vehicle state (step S11). The process in step S11 will be described in detail later (see FIG. 7). If the vehicle state obtained as a result of the process in step S11 is a "stopped state" (step S12; YES), the process proceeds to the next step S13. The process here corresponds to the "third process."

[0030] The vehicle state identification unit 12 performs a process based on information related to the vehicle transmission as one of the processes for identifying the vehicle state (step S13). The process at step S13 will be described in detail later (see FIG. 8). If the vehicle state obtained as a result of the process at step S13 is "stopped state" (step S14; YES), the process proceeds to the next step S15. The process here corresponds to the "second process."

[0031] As one of the processes for identifying the vehicle state, the vehicle state identification unit 12 performs a process based on the acceleration obtained using the acceleration sensor 21 provided in the vehicle (step S15). Details of the process in step S15 will be described later (see FIG. 9). If the vehicle state obtained as a result of the process in step S15 is a "stopped state" (step S16; YES), the vehicle state identification unit 12 identifies the vehicle state as a "stopped state". The process in step S11 corresponds to the "first process".

[0032] When the state of the vehicle is identified as a "stopped state," the angle calculation unit 22 of the controller 10 calculates the attitude angle of the vehicle by a calculation method corresponding to the stopped state, using the acceleration value obtained by the acceleration sensor 21. Then, the optical axis adjustment unit 23 generates a control signal for adjusting the optical axis a of the headlamp units 30L, 30R in accordance with the attitude angle obtained by the angle calculation unit 22, and outputs the signal to the headlamp units 30L, 30R. The leveling actuator 32 operates based on this control signal, thereby adjusting the optical axis a of the light from the light source 31. That is, optical axis control corresponding to the stopped state is executed (step S17).

[0033] On the other hand, if the vehicle state obtained in any of steps S12, S14, and S16 is not a "stopped state" (steps S12, S14, and S16; NO), the vehicle state identification unit 12 identifies the vehicle state as a "non-stopped state." The "non-stopped state" here may include both a case where the vehicle is in a traveling state and a case where the vehicle is not in a stable stopped state.

[0034] When the vehicle state is determined to be a "non-stopped state," the angle calculation unit 22 of the controller 10 does not calculate the vehicle attitude angle. In this case, the optical axis adjustment unit 23 does not output a control signal for adjusting the optical axis a of the headlamp units 30L, 30R according to the attitude angle calculated by the angle calculation unit 22, or continues to output a control signal according to the attitude angle calculated in the previous calculation. This keeps the optical axis a of the light from the light source 31 unchanged. That is, optical axis control appropriate for driving is executed (step S18). The angle calculation unit 22 may calculate the vehicle attitude angle using various known methods suitable for when the vehicle state is a "non-stopped state." In this case, the optical axis adjustment unit 23 outputs a control signal according to the obtained attitude angle.

[0035] Fig. 7 is a flowchart showing the detailed operation procedure of step S11 shown in Fig. 6. Hereinafter, with reference to Fig. 7, a process based on the vehicle speed and wheel speed as one of the processes for identifying the vehicle state will be described in detail.

[0036] The vehicle state identification unit 12 of the controller 10 determines whether the vehicle speed is 0 km / h or less based on the pulse signal (vehicle speed pulse) output from the vehicle speed sensor 40 (step S31). As described above, if the vehicle speed sensor 40 generates several pulses per axle revolution, for example, when the vehicle starts to move slightly, it takes a considerable amount of time from the time the vehicle starts to move until a pulse signal is obtained. In such a case, or when the vehicle is actually stopped, no pulse signal is obtained in this step, so it can be determined that the speed is not 0 km / h or more (the vehicle is stopped).

[0037] If the vehicle speed based on the vehicle speed pulse is 0 km / h or less (step S31; YES), the vehicle state identification unit 12 determines whether the wheel speed is 0 km / h or less based on the wheel speed signal from the wheel speed sensor 41 (step S32). As described above, the wheel speed signal is obtained promptly once the wheels have started to rotate. Therefore, it is possible to deal with, for example, a situation where the vehicle has started to move slightly.

[0038] If the wheel speed based on the wheel speed signal is equal to or less than 0 km / h (step S32; YES), the vehicle state specifying unit 12 specifies that the vehicle state is a "stopped state" (step S33).

[0039] On the other hand, if the vehicle speed based on the vehicle speed pulse is greater than 0 km / h (step S31; NO), or if the wheel speed based on the wheel speed signal is greater than 0 km / h (step S32; NO), the vehicle state identification unit 12 identifies the vehicle state as "non-stopped state" (step S34).

[0040] As described above, when the processing based on the vehicle speed and the wheel speed is completed and the vehicle state is determined to be either a "stopped state" or a "non-stopped state," the process proceeds to step S12 (see FIG. 6). Note that in this processing, only one of the processing based on the vehicle speed or the processing based on the wheel speed may be performed.

[0041] Fig. 8 is a flowchart showing the detailed operation procedure of step S13 shown in Fig. 6. Hereinafter, with reference to Fig. 8, a process based on information relating to the transmission as one of the processes for identifying the vehicle state will be described in detail.

[0042] The vehicle state identification unit 12 determines whether the vehicle is an automatic vehicle using the in-vehicle information acquired by the in-vehicle information acquisition unit 11 from other in-vehicle devices via the in-vehicle network (step S41). In this specification, an "automatic vehicle" refers to a vehicle in which gear changes are performed automatically from the time the vehicle starts moving until normal driving. Whether the vehicle is an automatic vehicle can be identified based on, for example, vehicle model information, which is an example of in-vehicle information. In this case, the vehicle model information includes information that can identify whether the transmission installed in the vehicle is automatic, such as the vehicle name, grade, year, and model.

[0043] If the vehicle is an automatic vehicle (step S41; YES), the vehicle state identification unit 12 uses the in-vehicle information acquired from the in-vehicle network by the in-vehicle information acquisition unit 11 to determine whether the position of the shift lever of the vehicle is "P (parked)" (step S42). The position of the shift lever can be identified based on shift position information indicating the position of the vehicle's shift lever. The shift position information can be received via the in-vehicle network depending on the position of the shift lever.

[0044] If the position of the shift lever is "P" (step S42; YES), the vehicle state specifying unit 12 specifies that the state of the vehicle is "parked state" (step S43).

[0045] On the other hand, if the vehicle is a manual vehicle or the like and not an automatic vehicle (step S41; NO), or if the position of the shift lever of the vehicle is other than "P" (step S42; NO), the vehicle state identification unit 12 identifies the vehicle state as "non-stopped state" (step S44).

[0046] As described above, when the processing based on the information about the transmission is completed and the vehicle state is identified as either a "stopped state" or a "non-stopped state," the process proceeds to step S14 (see FIG. 6).

[0047] Fig. 9 is a flowchart showing the detailed operation procedure of step S15 shown in Fig. 6. Hereinafter, with reference to Fig. 9, a process based on acceleration obtained using acceleration sensor 21 provided in the vehicle, which is one of the processes for identifying the vehicle state, will be described in detail.

[0048] The vehicle condition identification unit 12 determines whether the vehicle is an engine vehicle or not by using the in-vehicle information acquired by the in-vehicle information acquisition unit 11 from other in-vehicle devices via the in-vehicle network (step S51). In this specification, an "engine vehicle" refers to a vehicle that uses only an engine (internal combustion engine) as its main power source, such as a vehicle equipped with a gasoline engine or a diesel engine. Whether the vehicle is an engine vehicle or not can be determined based on, for example, vehicle model information, which is an example of in-vehicle information. In this case, the vehicle model information includes information that can identify whether the vehicle is an engine vehicle or not, such as the vehicle name, grade, year, and model.

[0049] If the host vehicle is an engine vehicle (step S51; YES), the vehicle state identification unit 12 uses in-vehicle information acquired by the in-vehicle information acquisition unit 11 from other in-vehicle devices via the in-vehicle network to determine whether the host vehicle is in a state other than a so-called idle stop state (step S52). Note that the "idle stop state" in this specification refers to a state in which, in a vehicle equipped with a function that automatically stops the engine when the engine vehicle is temporarily stopped, the function is activated. Whether the host vehicle is in an idle stop state can be determined based on vehicle status information received via the in-vehicle network.

[0050] If the host vehicle is not in an idle-stop state (step S52; YES), the vehicle state identification unit 12 sets the reference value used in the determination process of step S55, which will be described later, to a first value (step S53). On the other hand, if the host vehicle is a vehicle other than an engine vehicle, such as a so-called hybrid vehicle or an electric vehicle (step S51; NO), or if the host vehicle is in an idle-stop state (step S52; NO), the vehicle state identification unit 12 sets the reference value used in the determination process of step S55, which will be described later, to a second value (step S54).

[0051] Here, the "reference value" is used as a threshold value when determining whether the host vehicle is in a stopped state based on acceleration. When the host vehicle is an engine vehicle and is not in an idle-stop state, the vibration of the vehicle becomes relatively large, so a value relatively larger than the second value is used as the first value. When the host vehicle is not an engine vehicle or is in an idle-stop state, the vibration of the vehicle becomes relatively small, so a value relatively smaller than the first value is used as the second value.

[0052] The first value and the second value can be set appropriately based on experiments, simulations, etc., and it is also preferable to set different values ​​depending on the vehicle model. As an example, in this embodiment, the first value is set to 5 mG in absolute value, and the second value is set to 2 mG in absolute value. Note that these numerical values ​​are merely examples.

[0053] The vehicle state identification unit 12 determines whether the absolute value of the acceleration (for example, the acceleration corresponding to the vehicle's vertical direction) obtained using the acceleration sensor 21 is smaller than a reference value (first value or second value) (step S55). The acceleration corresponding to the vehicle's vertical direction hardly fluctuates when the host vehicle is traveling at a constant speed or when the vehicle is stopped, but fluctuates when accelerating or decelerating. Therefore, by comparing the acceleration with the reference value, it is possible to determine whether the vehicle is stopped.

[0054] If the absolute value of the acceleration is smaller than the reference value (step S55; YES), the vehicle state specifying unit 12 specifies that the state of the vehicle is a "stopped state" (step S56).

[0055] On the other hand, if the absolute value of the acceleration is equal to or greater than the reference value (step S55; NO), the vehicle state specifying unit 12 specifies that the state of the vehicle is a "non-stopped state" (step S57).

[0056] As described above, when the processing based on the acceleration is completed and the vehicle state is specified as either a "stopped state" or a "non-stopped state," the process proceeds to step S16 (see FIG. 6).

[0057] According to the above-described embodiment, the optical axis adjustment is performed according to the vehicle state. Specifically, the accuracy of identifying the vehicle state is improved by performing processing based on the vehicle speed and wheel speed, processing based on information related to the transmission, and processing based on acceleration, thereby improving the accuracy of the optical axis adjustment.

[0058] The present disclosure is not limited to the contents of the above-described embodiment, and various modifications can be made within the scope of the gist of the present disclosure. For example, in the above-described embodiment, three processes are performed: a process based on vehicle speed and wheel speed, a process based on information related to the transmission, and a process based on acceleration. However, only one of the processes may be performed, or two of the processes may be combined.

[0059] Furthermore, in the above embodiment, control was performed based on the wheel speed detected by the wheel speed sensor, but instead, the vehicle may be determined to be in a "non-stopped state" when the rotation of the drive shaft or propeller shaft is detected by each of the above sensors, and the vehicle may be determined to be in a "stopped state" when no rotation is detected.

[0060] Furthermore, in the above-described embodiment, the headlamp unit to be controlled is exemplified as one that mechanically adjusts the optical axis (light irradiation direction) using an actuator, but the configuration of the headlamp unit is not limited to this. For example, a headlamp unit that can freely control the light irradiation range using multiple light-emitting elements may be used, and the optical axis may be adjusted by controlling the on / off of each light-emitting element. Alternatively, a lamp unit may be used that includes a light source and a light modulation device (such as a liquid crystal device) with multiple shutter elements that can transmit and block (or dim) light from the light source in sections, and the optical axis may be adjusted by controlling the light blocking area of ​​the light modulation device. Alternatively, a lamp unit may be used that includes a laser element, a controller that controls the on / off of the light emitted from the laser element, a scanning device that scans the direction of the laser light and makes it incident on a phosphor, and a phosphor that generates fluorescence in response to the laser light, and the optical axis may be adjusted by controlling the scanning state of the laser light. [Explanation of symbols]

[0061] 10: Controller, 11: In-vehicle information acquisition unit, 12: Vehicle state identification unit, 21: Acceleration sensor, 22: Angle calculation unit, 23: Optical axis adjustment unit, 30L, 30R: Headlight unit, 31: Light source, 32: Leveling actuator, 40: Vehicle speed sensor, 41: Wheel speed sensor, 42: Drive shaft rotation detection sensor, 43: Propeller shaft rotation detection sensor

Claims

1. A device for controlling the optical axis of light emitted by a vehicle headlight, an acceleration sensor mounted on the vehicle; an identification unit that identifies whether the vehicle is in a stopped state or a non-stop state; an optical axis adjusting unit that adjusts the optical axis of the irradiated light by control corresponding to each of the cases where the vehicle is in the stopped state and the non-stop state, in response to the identification result by the identifying unit; Including, The identification unit performs, as a first process, a process of setting a reference value related to acceleration to a first value if the vehicle is an engine vehicle, and setting the reference value to a second value smaller than the first value if the vehicle is not an engine vehicle, and identifying the state of the vehicle as the stopped state if the absolute value of the acceleration detected using the acceleration sensor is smaller than the reference value, and identifying the state of the vehicle as the non-stop state if the absolute value of the acceleration is equal to or greater than the reference value. A control device for vehicle headlights.

2. In the first processing, the identification unit sets the reference value to the first value when the vehicle is an engine vehicle and is not in an idle stop state, and sets the reference value to the second value when the vehicle is an engine vehicle but is in an idle stop state. The vehicle headlamp control device according to claim 1 .

3. The acceleration detected by the acceleration sensor is an acceleration corresponding to a vertical direction of the vehicle. The vehicle headlamp control device according to claim 1 or 2.

4. the identification unit performs, as a second process, a process of identifying the state of the vehicle as the stopped state without performing the first process if the vehicle is an automatic vehicle and the position of the shift lever of the vehicle is a position corresponding to stopping, and a process of identifying the state of the vehicle as the non-stop state if the vehicle is not an automatic vehicle and / or the position of the shift lever of the vehicle is not a position corresponding to stopping, the identification unit further performs the first process to identify the state of the vehicle when the state of the vehicle is identified as the non-stop state in the second process. The vehicle headlamp control device according to any one of claims 1 to 3.

5. the determination unit performs, as a third process, a process of determining whether a state of the vehicle is the stopped state or the non-stop state based on a vehicle speed and / or a wheel speed of the vehicle; When the state of the vehicle is determined to be the non-stop state in the third process, the determination unit further performs the second process to determine the state of the vehicle. The vehicle headlamp control device according to claim 4.

6. A method for controlling an optical axis of light emitted by a vehicle headlight, comprising: (a) Identifying whether the vehicle is in a stationary or non-stationary state; (b) adjusting the optical axis of the irradiated light by control corresponding to each of the cases where the state of the vehicle is the stopped state and the non-stop state, based on the identification result obtained by (a); Including, (a) performs, as a first process, a process of setting a reference value related to acceleration to a first value if the vehicle is an engine vehicle, and setting the reference value to a second value smaller than the first value if the vehicle is not an engine vehicle, and determining that the state of the vehicle is the stopped state if the absolute value of the acceleration detected using the acceleration sensor is smaller than the reference value, and determining that the state of the vehicle is the non-stop state if the absolute value of the acceleration is equal to or greater than the reference value; A method for controlling a vehicle headlamp.

7. The control device according to any one of claims 1 to 5, a headlamp whose optical axis is controlled by the control device; A vehicle headlamp system comprising:

Images