JP2022014611A - Control device for vehicular headlight, control method for vehicular headlight, and vehicular headlight system - Google Patents

Abstract

To provide a vehicular headlight system that makes optical axis adjustments according to vehicle states.SOLUTION: In a vehicular headlight system, a control device for vehicular headlight is configured to control the optical axis of irradiation light from a headlight unit 30 of a vehicle, and includes: a wheel speed sensor 41 which detects a wheel speed of the vehicle; a vehicle state determination part 11 which is connected to the wheel speed sensor 41, and determines whether the vehicle is in a stop state or travel state based upon the wheel speed; and an optical axis adjustment part 23 which receives the determination result of the vehicle state determination part 11, and adjusts the optical axis of the irradiation light under control adaptive to the stop state and travel state of the vehicle.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a technique for controlling vehicle headlights.

Japanese Patent Application Laid-Open No. 2013-71477 (Patent Document 1) uses the output value of the tilt sensor when a signal output by the vehicle interior door open / close sensor or a signal output by the trunk door open / close sensor is received while the vehicle is stopped. Controls to generate and output an adjustment signal that instructs the adjustment of the optical axis of the vehicle lighting equipment, and avoids the output of the adjustment signal or generates a maintenance signal that instructs the maintenance of the optical axis position while the vehicle is running. A control device for a vehicle lighting device that controls to output is described. In this control device, the detection value of the vehicle speed sensor is used to determine whether the vehicle is stopped or running.

By the way, in general, many vehicle speed sensors generate 10 or less (for example, 2 to 8) pulse signals per rotation of an axle. Therefore, when the vehicle speed is extremely low (for example, 5 km / h or less) such as when the vehicle is creeping, it takes a certain amount of time from the start of the vehicle movement to the generation of the pulse signal. During this time, the corresponding optical axis adjustment may be performed during the stop, and the optical axis may not be appropriate.

Japanese Unexamined Patent Publication No. 2013-71477

One of the specific aspects of the present disclosure is to perform optical axis adjustment according to the state of the vehicle.

[1] The control device for a vehicle headlight according to the present disclosure is (a) a device for controlling the optical axis of the irradiation light of the vehicle headlight, and (b) the vehicle. A wheel speed sensor that detects the wheel speed, and (c) a determination unit that is connected to the wheel speed sensor and determines whether the vehicle is in a stopped state or a running state based on the wheel speed. (D) An optical axis adjusting unit that adjusts the optical axis of the irradiation light by control corresponding to each of the case where the vehicle is in the stopped state and the case where the vehicle is in the traveling state in response to the determination result of the determination unit. Is a vehicle headlight control device, including.
[2] The vehicle headlight system according to the present disclosure is a vehicle headlight system including the control device of 1 above and a headlight whose optical axis is controlled by the control device. be.
[3] One aspect of the vehicle headlight control method according to the present disclosure is (a) a method for controlling the optical axis of the irradiation light of the vehicle headlight, and (b) the vehicle. Detecting the wheel speed, (c) determining whether the state of the vehicle is a stopped state or a running state based on the detected wheel speed, (d) the state of the vehicle is the stopped state. It is a control method of a headlight for a vehicle including adjusting the optical axis of the irradiation light by the control corresponding to each of the case of the above and the case of the traveling state.

According to the above configuration, the optical axis adjustment according to the state of the vehicle is executed.

FIG. 1 is a block diagram showing a configuration of a vehicle headlight system according to an embodiment. FIG. 2 is a diagram showing a configuration example of a computer system that realizes a vehicle control ECU. FIG. 3 is a diagram schematically showing the configuration and operation of the headlight unit. FIG. 4 is a diagram schematically showing a configuration example of the wheel speed sensor. 5 (A) and 5 (B) are waveform diagrams showing an example of a detection signal output from the Hall element of the wheel speed sensor. FIG. 6 is a flowchart showing an operating procedure of the vehicle headlight system.

FIG. 1 is a block diagram showing a configuration of a vehicle headlight system according to an embodiment. The illustrated vehicle headlight system includes a vehicle control ECU (Electronic Control Unit) 10, a leveling ECU (Electronic Control Unit) 20, a headlight unit 30, a vehicle speed sensor 40, a wheel speed sensor 41, and a drive shaft rotation detection sensor 42. , The propeller shaft rotation detection sensor 43, and the orientation sensor 44 are included. The headlight units 30 are actually installed one on each side of the front part of the vehicle, but only one headlight unit 30 is shown for the sake of simplification of the explanation.

The vehicle control ECU 10 is for performing control related to the vehicle such as turning on / off control of the headlight unit 30. The vehicle control ECU 10 is realized by using, for example, a computer system having a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like, and executing a predetermined operation program in the computer system. Is to be done. The vehicle control ECU 10 of the present embodiment has a vehicle state determination unit 11 as a functional block realized by executing an operation program on the CPU. Further, the vehicle control ECU 10 of the present embodiment has a built-in acceleration sensor 12.

The leveling ECU 20 is for controlling the optical axis (leveling) of the headlight unit 30. The leveling ECU 20 is realized by using, for example, a computer system having a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like, and executing a predetermined operation program in the computer system. It is a thing. The leveling ECU 20 of the present embodiment has an angle calculation unit 22 and an optical axis adjustment unit 23 as functional blocks realized by executing an operation program on the CPU. Further, the leveling ECU 20 of the present embodiment has a built-in acceleration sensor 21.

The headlight unit 30 is installed at a predetermined position in the front part of the vehicle and is for irradiating the front of the vehicle with light. The headlight unit 30 of the present embodiment includes a light source 31 and a leveling actuator 32. The headlight unit 30 is connected to each of the vehicle control ECU 10 and the leveling ECU 20, and the vehicle control ECU 10 controls the on / off operation of the light source 31, and the leveling ECU 20 controls the operation of the leveling actuator 32. As a result, the optical axis of the emitted light of the light source 31 is adjusted.

The vehicle speed sensor 40 generates a pulse signal (vehicle speed pulse) which is an intermittent signal according to the rotation speed of the axle (shaft for mounting the wheel) of the vehicle, and is connected to the vehicle control ECU 10. The vehicle speed sensor 40 generates, for example, several pulse signals per rotation of the axle. Therefore, for example, when the vehicle is moving at a very low speed such as 5 km / h or less due to a creep phenomenon or the like, it takes a relatively long time to generate a pulse signal from the vehicle speed sensor 40.

The wheel speed sensor 41 detects the wheel speed, which is the rotational speed of the wheels attached to the axle of the vehicle, and is connected to the vehicle control ECU 10. The wheel speed sensor 41 of the present embodiment indirectly detects the rotation speed of the wheel by detecting the rotation speed of a portion rotating with the wheel, such as an axle hub, a brake drum, and a drive shaft. It may be the one which detects the rotation speed directly from a wheel.

The drive shaft rotation detection sensor 42 detects the rotation speed of the drive shaft of the vehicle, and is connected to the vehicle control ECU 10. The drive shaft referred to here is for transmitting the driving force generated by a power source such as an engine or a motor to the wheels of a vehicle. When the wheel speed sensor 41 described above detects the wheel speed based on the rotation speed of the drive shaft, the drive shaft rotation detection sensor 42 may be omitted.

The propeller shaft rotation detection sensor 43 detects the rotation speed of the propeller shaft of the vehicle, and is connected to the vehicle control ECU 10. The propeller shaft referred to here is for transmitting the driving force generated by a power source such as an engine or a motor arranged at the front of the vehicle to a differential gear at the rear of the vehicle, for example, in a four-wheel drive vehicle or a rear-wheel drive vehicle. It is a thing. In the case of a vehicle not provided with a propeller shaft, the propeller shaft rotation detection sensor 43 is omitted.

The direction sensor 44 is for detecting the vehicle direction, and is connected to the vehicle control ECU 10. As the directional sensor 44, for example, a geomagnetic directional sensor can be used.

The vehicle state determination unit 11 of the vehicle control ECU 10 uses the pulse signal obtained from the vehicle speed sensor 40 and the wheel speed signal obtained from the wheel speed sensor 41 to determine whether the vehicle state is the "stop state" or the "running state". Is determined. The specific determination method will be described later. The vehicle state determination unit 11 may determine the state of the vehicle by using one or more of the detection results of the drive shaft rotation detection sensor 42, the propeller shaft rotation detection sensor 43, and the orientation sensor 44. In this embodiment, a case where a pulse signal and a wheel speed signal are used will be described as an example, but other embodiments are not excluded.

The acceleration sensor 12 of the vehicle control ECU 10 detects, for example, the acceleration in each of the three axes orthogonal to each other, and is installed in the vehicle so that each of the three axes corresponds to the front-rear direction, the left-right direction, and the up-down direction of the vehicle. Orthogonal. In the present embodiment, the acceleration sensor 12 is built in the vehicle control ECU 10, but the acceleration sensor 12 may be externally attached without being built in the vehicle control ECU 10.

The acceleration sensor 21 of the leveling ECU 20 detects, for example, the acceleration in each of the three axes orthogonal to each other, and is installed in the vehicle so that each of the three axes corresponds to the front-rear direction, the left-right direction, and the up-down direction of the vehicle. .. In the present embodiment, the acceleration sensor 21 is built in the leveling ECU 20, but the acceleration sensor 21 may be externally attached without being built in the leveling ECU 20.

The angle calculation unit 22 of the leveling ECU 20 calculates the posture angle of the vehicle based on the acceleration detected by the acceleration sensor 21. The posture angle of the vehicle is the angle formed by the front-rear axis of the vehicle and the road surface (reference axis). The optical axis of the irradiation light from the headlight unit 30 is adjusted by the optical axis adjusting unit 23 according to the change in the posture angle.

The angle calculation unit 22 of the present embodiment calculates the posture angle of the vehicle when the state of the vehicle is in the stopped state, but does not calculate the posture angle of the vehicle when the state of the vehicle is in the running state. Various known methods can be used for calculating the posture angle of the vehicle in the stopped state, and the method is not particularly limited. As a simple example, assuming that the acceleration corresponding to the vehicle front-rear direction obtained by the acceleration sensor 21 is Xa and the acceleration corresponding to the vehicle vertical direction is Ya, the posture angle θ of the vehicle is θ = tan ^-1 (Xa /). It can be calculated as Ya). The posture angle may be calculated even when the vehicle is in a traveling state. As the calculation method in that case, various known methods can be used, and there is no particular limitation.

The optical axis adjusting unit 23 of the leveling ECU 20 adjusts the optical axis of the irradiation light by the headlight unit 30 based on the posture angle of the vehicle obtained by the angle calculation unit 22. Specifically, the optical axis adjusting unit 23 generates a control signal for operating the leveling actuator 32 of the headlight unit 30.

The light source 31 of the headlight unit 30 receives electric power from a power source (not shown) to generate light. The light source 31 may be any one that can generate light, and 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 is used.

The leveling actuator 32 of the headlight unit 30 directs the light source 31 in order to adjust the angle of the optical axis, which is the main traveling direction of the light by the light source 31, based on the control signal supplied from the optical axis adjusting unit 23. Set to variable.

FIG. 2 is a diagram showing a configuration example 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 connected to each other so as to be communicable with each other. The CPU 201 operates based on the basic control program read from the ROM 202, reads the program (application program) 206 stored in the storage device 204, and executes the program (application program) 206. As a result, the functions of the vehicle state determination unit 11 and the like described above are realized. The RAM 203 temporarily stores data to be used during the operation of the CPU 201. The storage device 204 is a non-volatile data storage device such as a hard disk or SSD (Solid State Drive), and stores various data such as a program 206. The external interface 205 is an interface for connecting the CPU 201 and an external device. In this embodiment, it is used for connecting the vehicle speed sensor 40, the wheel speed sensor 41, and the like to the CPU 201. The acceleration sensor 207 corresponds to the above-mentioned acceleration sensor 12.

The computer system that realizes the leveling ECU 20 also has the same configuration as that illustrated in FIG. 2, and the angle calculation unit 22 and the optical axis adjustment unit described above are executed by executing the program (application program) 206 in the CPU 201. Functions such as 23 are realized. Further, the acceleration sensor 207 corresponds to the above-mentioned acceleration sensor 21.

FIG. 3 is a diagram schematically showing the configuration and operation of the headlight unit. The headlight unit 30 of the present embodiment is arranged in front of the light source 31, the housing 33 accommodating the light source 31, and the light source 31 (in the direction in which light is emitted), and is fixed to the housing 33. A lens 34 is provided. A reflective surface that reflects light from the light source 31 forward is provided on the inner surface of the housing 33. The actuator 32 is connected to a housing 33 that houses the light source 31, and changes the posture of the housing 33. Thereby, the optical axis a of the light from the light source 31 can be set variably. For example, when the rear part of the vehicle is relatively lowered, the optical axis a is controlled to face downward, and when the front part of the vehicle is relatively lowered, the optical axis a is controlled to face upward. Be controlled. At that time, how much downward or upward is set according to the posture angle of the vehicle.

FIG. 4 is a diagram schematically showing a configuration example of the wheel speed sensor. The wheel speed sensor 41 of the present 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 configured by using, for example, magnetized rubber, and N poles and S poles are alternately arranged along the circumferential direction. The magnetic sensor rotor 50 is provided in a portion (rotating body) that rotates in conjunction with the rotation of wheels such as the axle hub described above. The smaller the installation range r of the pair of magnetic poles (one pair of N poles and one pair of S poles adjacent to it) is preferable. This is because the smaller the installation range r, the more the wheel speed can be detected corresponding to the slight rotation of the wheel. Specifically, the installation range r may be set to, for example, 1 / n of the circumference of the magnetic sensor rotor 50, and n in this case can be at least a number larger than 4 and a number larger than 8. It can also be a number larger than 16. The larger n is, the earlier the wheel speed can be detected. The Hall element 51 detects a change in the magnetic field caused by the rotation of the magnetic sensor rotor 50, and is arranged with a predetermined gap between the Hall element 51 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. The configuration shown in FIG. 4 is an example, and the configuration of the wheel speed sensor 41 is not limited to this.

5 (A) and 5 (B) are waveform diagrams showing an example of a detection signal output from the Hall element of the wheel speed sensor. In the wheel speed sensor 41 of the present embodiment, a sinusoidal detection signal that repeats positive and negative alternately is obtained from the Hall element 51 in response to a continuous change in the magnetic field accompanying the rotation of the magnetic sensor rotor 50. The waveform of the detection signal shown in FIG. 5A is a detection signal when the rotation speed is relatively small, and the waveform of the detection signal shown in FIG. 5B is a detection signal when the rotation speed is relatively high. be. The higher the rotation speed, the higher the frequency of the detection signal. In principle, this detection signal can be obtained even if the rotation speed of the magnetic sensor rotor 50 is extremely small. This is because a signal for one cycle is obtained every time the N pole and the S pole at the positions facing the Hall element 51 are exchanged, and the N pole and the S pole can be alternately arranged in a relatively narrow range. .. In the wheel speed sensor 41 of the present embodiment, the detection signal by 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 a wheel speed signal. Specifically, when the wheel speed signal of the square wave signal is input to the vehicle control ECU 10, the vehicle control ECU 10 calculates the frequency of the square wave based on the wheel speed signal, and the wheel is based on the magnitude of this frequency. Get speed. The signal processing method shown here is an example, and is not limited thereto.

FIG. 6 is a flowchart showing an operating procedure of the vehicle headlight system. As long as there is no contradiction or inconsistency in the results of information processing, the order of each step may be changed as appropriate, or other steps (not shown) may be added.

The vehicle state determination unit 11 of the vehicle control ECU 10 determines whether or not a pulse signal (vehicle speed pulse) is obtained from the vehicle speed sensor 40 (step S11). As described above, when the vehicle speed sensor 40 generates several pulses for each rotation of the axle, for example, when the vehicle starts to move slightly, from the time when the vehicle starts to move until a pulse signal is obtained. It takes a considerable amount of time. In such a case, or when the vehicle is really stopped, it is determined that the pulse signal has not been obtained in this step.

When the vehicle speed pulse is not obtained (step S11; NO), the vehicle state determination unit 11 determines whether or not the wheel rotation is detected based on the wheel speed signal from the wheel speed sensor 41 (step S11; NO). Step S12). As described above, the wheel speed signal is obtained promptly if the wheel rotation has started. Therefore, for example, even when the vehicle starts to move slightly, it can be dealt with.

If the rotation of the wheels is not detected (step S12; NO), the vehicle state determination unit 11 determines that the vehicle state is "stopped" and outputs the determination result to the leveling ECU 20 (step). S13).

Upon receiving the determination result that the vehicle state is the "stop state", the angle calculation unit 22 of the leveling ECU 20 uses the acceleration value obtained by the acceleration sensor 21 and uses the calculation method corresponding to the stop state to determine the posture angle of the vehicle. Is calculated. Then, the optical axis adjusting unit 23 generates a control signal for adjusting the optical axis a of the headlight unit 30 according to the posture angle obtained by the angle calculation unit 22, and outputs the control signal to the headlight unit 30. .. By operating the leveling actuator 32 based on this control signal, the optical axis a of the light from the light source 31 is adjusted. That is, the optical axis control corresponding to the stop is executed (step S14).

On the other hand, when the vehicle speed pulse is obtained (step S11; YES), or when the rotation of the wheels is detected (step S12; YES), the vehicle state determination unit 11 determines that the vehicle state is ". It is determined that the vehicle is in a "running state", and the determination result is output to the leveling ECU 20 (step S15).

The angle calculation unit 22 of the leveling ECU 20 that has received the determination result that the state of the vehicle is the "running state" does not calculate the posture angle of the vehicle. In this case, the optical axis adjusting unit 23 does not output a control signal for adjusting the optical axis a of the headlight unit 30 according to the attitude angle obtained by the angle calculation unit 22, or obtains it in the previous calculation. The output of the control signal according to the determined attitude angle is continued. As a result, the optical axis a of the light from the light source 31 is maintained unchanged. That is, the optical axis control corresponding to the traveling time is executed (step S16).

According to the above embodiment, the optical axis adjustment according to the state of the vehicle is executed.

It should be noted that the present disclosure is not limited to the contents of the above-described embodiment, and can be variously modified and implemented within the scope of the gist of the present disclosure. For example, in the above embodiment, the control is performed based on the wheel speed detected by the wheel speed sensor, but instead of this, when the rotation of the drive shaft or the propeller shaft is detected by each of the above sensors, the vehicle It may be determined that the vehicle is in the "running state", and the vehicle may be determined to be in the "stopped state" when the rotation is not detected. Similarly, it may be determined that the vehicle is in the "running state" when the change in the directional sensor of the vehicle is detected, and the vehicle may be determined to be in the "stopped state" when the change in the directional sensor is not detected. ..

10: Vehicle control ECU, 11: Vehicle condition determination unit, 12: Acceleration sensor, 20: Leveling ECU, 21: Acceleration sensor, 22: Angle calculation unit, 23: Optical axis adjustment unit, 30: 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, 44: Direction sensor

Claims (6)

It is a device for controlling the optical axis of the irradiation light from the headlights of the vehicle.
A wheel speed sensor that detects the wheel speed of the vehicle and
A determination unit that is connected to the wheel speed sensor and determines whether the vehicle is in a stopped state or a running state based on the wheel speed.
An optical axis adjusting unit that adjusts the optical axis of the irradiation light by control corresponding to each of the case where the vehicle is in the stopped state and the case where the vehicle is in the traveling state in response to the determination result of the determination unit.
Vehicle headlight controls, including. The wheel speed sensor is
A magnetic sensor rotor provided in association with the circumferential direction of a rotating body that rotates in conjunction with the rotation of the wheel, and
A detection element that detects changes in the magnetic field due to rotation of the magnetic sensor rotor, and
A signal processing circuit that generates a wheel speed signal based on the change in the magnetic field detected by the detection element, and
The vehicle headlight control device according to claim 1. Further equipped with a vehicle speed sensor that outputs a number of pulse signals according to the vehicle speed of the vehicle.
When the pulse signal is obtained, the determination unit determines that the vehicle is in a running state without making a determination based on the wheel speed, and when the vehicle speed pulse is not obtained, the determination unit determines the wheel speed. Judging the state of the vehicle based on
The vehicle headlight control device according to claim 1 or 2. Further equipped with an acceleration sensor, which detects acceleration corresponding to at least the front-rear direction and the vertical direction of the vehicle.
The optical axis adjusting unit adjusts the optical axis of the irradiation light based on the detection result of the acceleration sensor.
The control device for a vehicle headlight according to any one of claims 1 to 3. The control device according to any one of claims 1 to 4,
A headlight whose optical axis is controlled by the control device,
Headlight system for vehicles, including. It is a method for controlling the optical axis of the irradiation light from the headlight of the vehicle.
To detect the wheel speed of the vehicle,
Determining whether the vehicle is in a stopped state or a running state based on the detected wheel speed.
Adjusting the optical axis of the irradiation light by control corresponding to each of the case where the vehicle is in the stopped state and the state in which the vehicle is in the running state.
How to control vehicle headlights, including.

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