Control device of vehicular lighting fixture, control method of vehicular lighting fixture, and vehicular lighting fixture system

Abstract

To provide a technique that realizes a distribution of light according to a steering state of a driver.SOLUTION: A control device of a vehicular lighting fixture is a device for controlling operation of a vehicular lighting fixture that allows a distribution of light to be variably set. The control device includes a controller which is connected to the vehicular lighting fixture. The controller controls the vehicular lighting fixture so that a low beam is radiated, and further, controls the vehicular lighting fixture so that an additional beam 102 is radiated in a prescribed range in front of a vehicle 100, if the signal intensity of a first frequency band set in a range of 0.3 Hz to 0.6 Hz exceeds a reference value in a frequency analysis result of a steering signal acquired by the vehicle 100.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a control device for a vehicle lamp, a control method for a vehicle lamp, and a vehicle lamp system. [Background technology]

[0002] Japanese Patent No. 3768624 (Patent Document 1) describes a control device that sets an index representing the degree of corrective steering based on the power spectrum of the steering angle, and issues a warning to the driver using an alarm means when the index exceeds a first threshold, and reduces the vehicle speed using a deceleration means when the index exceeds a second threshold. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 3768624 Summary of the Invention [Problem to be solved by the invention]

[0004] One object of a specific aspect of the present disclosure is to provide a technology capable of realizing light distribution according to the steering state of a driver. [Means for solving the problem]

[0005] [1] A control device for a vehicle lamp according to one aspect of the present disclosure includes: A device for controlling the operation of a vehicle lamp capable of variably setting light distribution, comprising: A controller connected to the vehicle lamp, The controller controls the vehicle lamp to emit a low beam, and controls the vehicle lamp to emit an additional beam to a predetermined range in front of the vehicle when a signal strength of a first frequency band set within a range of 0.3 Hz to 0.6 Hz in a frequency analysis result of a steering angle signal acquired from the vehicle exceeds a reference value. A control device for a vehicle lamp. [2] A method for controlling a vehicle lamp according to one aspect of the present disclosure includes: A method for controlling an operation of a vehicle lamp capable of variably setting a light distribution, comprising: a control unit that controls the vehicle lamp to emit a low beam, and controls the vehicle lamp to emit an additional beam in a predetermined range in front of the vehicle when a signal strength of a frequency band set in a range of 0.3 Hz to 0.6 Hz in a frequency analysis result of a steering angle signal acquired from the vehicle exceeds a reference value; A method for controlling a vehicle lamp. [3] A vehicle lighting system according to one embodiment of the present disclosure, The vehicle lighting control device according to [1] above, A vehicle lamp controlled by the vehicle lamp control device; A vehicle lighting system comprising:

[0006] According to the above configuration, it is possible to realize light distribution according to the steering state of the driver. [Brief description of the drawings]

[0007] [Figure 1] Fig. 1A is a block diagram showing a configuration of a vehicle lighting system according to an embodiment, and Fig. 1B is a diagram showing an example of the configuration of a computer system. [Diagram 2] FIG. 2 is a diagram for explaining the light emitted by the headlight. [Diagram 3] FIG. 3 is a diagram illustrating an example of an illuminance distribution of light emitted by a headlight on a cross section in the vehicle travel direction. [Figure 4] Fig. 4(A) is a diagram showing a schematic diagram of a steering angle signal, and Fig. 4(B) is a diagram showing a schematic diagram of a power spectrum obtained by performing a fast Fourier transform on the steering angle signal. [Diagram 5] FIG. 5 is a flowchart showing an operation procedure of the vehicle lighting system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] 1(A) is a block diagram showing the configuration of a vehicle lighting system according to an embodiment. The vehicle lighting system shown in the figure includes a controller 10, a steering angle sensor 11, and a pair of headlights (vehicle lighting devices) 12L and 12R. This vehicle lighting system is for emitting light ahead of the vehicle.

[0009] The controller 10 controls the operation of emitting light from each of the headlights 12L and 12R. The controller 10 can be configured using a computer system such as that shown in Fig. 1(B), that is, a computer system including a processor (CPU: Central Processing Unit) 201, a ROM (Read Only Memory) 202, a RAM (Random Access Memory) 203, a storage device 204 such as a flash memory, an input / output interface 205, and the like. The controller 10 of this embodiment is capable of performing each function described below by reading and executing a program 206 stored in advance in the storage device 204 by the processor.

[0010] The steering angle sensor 11 detects the steering angle, which is the rotation angle of the steering wheel that rotates in conjunction with the vehicle's steering wheel, and outputs a steering angle signal (steering angle data) according to the magnitude of the detection.

[0011] The controller 10 includes a signal analysis unit 21, a light distribution setting unit 22, and a control signal generation unit 23 as functional blocks realized by executing a program.

[0012] The signal analysis unit 21 performs a predetermined frequency analysis, specifically a fast Fourier transform, on the steering angle signal output over time from the steering angle sensor 11 to obtain a power spectrum for each predetermined frequency range (see FIG. 4(B) described later).

[0013] The light distribution setting unit 22 sets a light distribution pattern of the light irradiated by each of the headlights 12L, 12R based on the result of the frequency analysis by the signal analysis unit 21.

[0014] The control signal generating unit 23 generates a control signal for causing each of the headlights 12L, 12R to form irradiation light according to the light distribution pattern set by the light distribution setting unit 22, and supplies the control signal to each of the headlights 12L, 12R.

[0015] A pair of headlights 12L, 12R are mounted at predetermined positions on the left and right sides of the front of the vehicle, and operate in response to a control signal provided by the controller 10 to form light to be irradiated ahead of the vehicle. The headlight units 12L, 12R of this embodiment can variably set a light distribution pattern, and each includes a low beam unit 31 for irradiating a low beam (passing light), a high beam unit 33 for irradiating a high beam (driving light), and an additional beam unit 33 for irradiating an additional beam 102 within an irradiation range of the low beam 101 illustrated in Fig. 2 described later. The high beam unit 33 may be an ADB unit capable of forming a dimming range (or a light blocking range) according to the position of a vehicle ahead, etc.

[0016] Various known configurations can be adopted for each headlamp 12L, 12R. For example, a high beam, a low beam, and an additional beam can be formed by a lamp unit configured by combining a light source bulb with a reflector and a shielding plate. A lamp unit can also be used in which light emitting elements such as LEDs (Light Emitting Diodes) are arranged in one or two directions, and the lighting state of each light emitting element can be individually controlled. A lamp unit can also be used that includes a light source and a liquid crystal element, and that can individually control the light transmission state of each pixel of the liquid crystal element. A lamp unit can also be used that includes a light emitting element such as a laser diode, and a scanning element such as a mirror device that scans the light emitted from the light emitting element, and that can control the timing of turning on and off the light emitting element and the scanning timing by the scanning element.

[0017] FIG. 2 is a diagram for explaining the light emitted by the headlight. Here, a bird's-eye view of the host vehicle is shown in a schematic manner. As shown in the figure, a low beam 101 is emitted from the host vehicle 100 to the front thereof. In the illustrated example, the outer edge of the low beam 101 is at a position corresponding to 5 lx (lux). Furthermore, when the power spectrum of the steering angle signal satisfies a predetermined condition, an additional beam 102 is emitted from the host vehicle 100 to the front thereof. This additional beam 102 is irradiated within the irradiation range of the low beam 101 and to a predetermined range in front of the host vehicle 100, specifically, for example, within a range of 5 m to 40 m (in the illustrated example, within a range of 5 m to 35 m). Furthermore, the additional beam 102 is irradiated to a range including the driving lane of the host vehicle 100. For example, the additional beam 102 is irradiated with a width equal to or greater than the width W of the driving lane (for example, about 3.5 m).

[0018] FIG. 3 is a diagram illustrating an example of the illuminance distribution of the light irradiated by the headlight in a cross section in the vehicle travel direction. In the figure, the illuminance when only the low beam 101 is irradiated is indicated by a solid line, and the illuminance when the additional beam 102 is irradiated is indicated by a dotted line. As described above, the additional beam 102 is irradiated within the irradiation range of the low beam 101 and in a predetermined range in front of the vehicle 100 (for example, a range of 5 m to 40 m). At this time, the additional beam 102 is irradiated in the predetermined range in front so as to be 1.2 to 1.5 times brighter than the case where the low beam 101 is irradiated without the additional beam 102 being irradiated. The forward distance d1 at the position where the illuminance is the largest when the additional beam 102 is irradiated can be set to, for example, 20 m to 30 m.

[0019] Fig. 4(A) is a diagram showing a schematic diagram of a steering angle signal. Fig. 4(B) is a diagram showing a schematic diagram of a power spectrum obtained by performing a fast Fourier transform on the steering angle signal. As shown in Fig. 4(A), the steering angle signal changes over time in response to the driver's steering wheel operation. In this embodiment, the steering angle signal is subjected to a fast Fourier transform to calculate the signal strength (power) for each frequency. Then, as shown in Fig. 4(B), the signal strength in the frequency band of 0.1 Hz to 0.2 Hz and the signal strength in the frequency band of 0.3 Hz to 0.6 Hz are tallied.

[0020] Here, the reason for tabulating the signal strength in the 0.1-0.2 Hz frequency band and the 0.3-0.6 Hz frequency band will be described. According to the following paper by McLean, Hoffmann, et al., most of the steering angle signals during driving have a frequency of 1 Hz or less, and it has been found that the 0.1-0.2 Hz frequency band corresponds to preview steering, and the 0.3-0.6 Hz frequency band corresponds to compensation steering. For this reason, in this embodiment, the signal strength is tabulated separately for the 0.1-0.2 Hz frequency band and the 0.3-0.6 Hz frequency band, thereby obtaining information that can grasp the driver's state.

[0021] (1) McLean, JR and Hoffmann, ER (1971). Analysis of drivers' control movements. Human Factors, 13, 407-418. (2) McLean, JR and Hoffmann, ER (1973). The effects of restricted preview on driver steering control and performance. Human Factors, 15, 421-430.

[0022] In addition, the following paper shows that research results show that the peak of the steering angle signal shifts to the 0.3Hz to 0.6Hz band when the driver's lateral task demands increase. The "task" here refers to keeping the vehicle in the center of the lane (or on the driving path the driver wants to travel).

[0023] (3) Blaauw, GJ (1984). Car driving as a supervisory control task. Soesterberg, The Netherlands: Institute for Perception TNO.

[0024] In other words, since the steering angle signal reflects the driver's driving load, the driver's driving load state can be examined by frequency analysis of the steering angle signal. Also, an increase in the components in the frequency band of 0.3Hz to 0.6Hz in the steering angle signal indicates that the amount of compensation steering has increased because the amount of adjustment in the prior steering operation (preview steering appearing at 0.1Hz to 0.2Hz) was insufficient, and this indicates that the driver is not able to correctly recognize the driving position of his / her vehicle.

[0025] On the other hand, when comparing a vehicle equipped with HID lamps, which have a relatively bright light distribution in front of the vehicle, with a vehicle equipped with tungsten halogen lamps, which have a darker light distribution in front of the vehicle, the results of a survey have been published that show that the vehicle with a brighter light distribution in front of the vehicle is easier to drive (i.e., easier to recognize linearity) (UMTRI Report 2002-3). Therefore, by ensuring the brightness of the light distribution in front of the vehicle, it is expected that the driver will be able to easily grasp the driving position of the vehicle.

[0026] Therefore, in this embodiment, when the signal strength in the frequency band of 0.3 Hz to 0.6 Hz corresponding to the compensation steering exceeds a predetermined threshold, the above-mentioned additional beam 102 (see FIG. 2) is irradiated to a predetermined range in front of the vehicle, thereby assisting the driver in understanding the driving position.

[0027] Fig. 5 is a flowchart showing the operation procedure of the vehicle lighting system. The order of each process shown here can be changed as long as there is no contradiction or inconsistency in the results of the information processing, and other processes not shown here can be added. In the following description, the high beam is not mentioned, but it is assumed that the high beam is irradiated appropriately.

[0028] The light distribution setting unit 22 of the controller 10 acquires the signal strength for each frequency of the steering angle signal obtained by the signal analysis unit 21, and if the signal strength in the frequency band of 0.3 Hz to 0.6 Hz (first frequency band) does not exceed a predetermined threshold (step S11; NO), the light distribution setting unit 22 sets the light distribution pattern so as to maintain the current light distribution pattern, that is, the state in which the low beam is irradiated and the additional beam is not irradiated (step S12). Then, the process returns to step S11.

[0029] Here, the threshold value in step S11 can be set, for example, as follows. As one example, the average value of the signal strength in the frequency band of 0.3 Hz to 0.6 Hz during normal times (for example, during the day) can be obtained by experiment or the like, and the threshold value can be set based on the results. As another example, the signal strength in the frequency band of 0.1 Hz to 0.2 Hz (second frequency band) obtained during the same period can be used as the threshold value. In other words, the determination criterion can be whether or not the relationship of signal strength in the first frequency band > signal strength in the second frequency band is established.

[0030] When the signal strength in the frequency band of 0.3 Hz to 0.6 Hz exceeds a predetermined threshold (step S11; YES), the light distribution setting unit 22 switches the setting of the light distribution pattern of the light irradiated by the headlight so that an additional beam is irradiated in addition to the low beam (step S13). As a result, the additional beam 102 is irradiated.

[0031] Thereafter, if the state in which the signal strength in the frequency band of 0.3 Hz to 0.6 Hz exceeds the predetermined threshold continues (step S14; YES), the light distribution setting unit 22 sets the light distribution pattern to maintain the state of irradiating the additional beam (step S15). Then, the process returns to step S14. In other words, the irradiation of the additional beam continues while the state in which the signal strength in the frequency band of 0.3 Hz to 0.6 Hz exceeds the predetermined threshold continues.

[0032] On the other hand, when the state where the signal strength in the frequency band of 0.3 Hz to 0.6 Hz exceeds the predetermined threshold value no longer continues (step S14; NO), the light distribution setting unit 22 returns the setting of the light distribution pattern to the original state, that is, the state where the additional beam is not irradiated and the low beam is irradiated (step S16). Then, the process returns to step S11.

[0033] According to the above embodiment, when the compensation steering amount increases, that is, when it is presumed that the driver is unable to correctly recognize the vehicle's traveling position, an additional beam is irradiated to a specified range in front of the vehicle in addition to the low beam, so that light distribution according to the driver's steering state can be achieved.

[0034] The present disclosure is not limited to the contents of the above-mentioned embodiment, and various modifications can be made within the scope of the gist of the present disclosure. For example, in the above-mentioned embodiment, the frequency band of the steering angle signal is divided into a first frequency band of 0.3 Hz to 0.6 Hz and a second frequency band of 0.1 Hz to 0.2 Hz, but each numerical value is merely an example and is not limited to these. Specifically, the first frequency band may be set within a range of 0.3 Hz to 0.6 Hz, for example, 0.3 Hz to 0.5 Hz, and the second frequency band can be appropriately set within a range smaller than 0.3 Hz.

[0035] The present disclosure has the following features. (Appendix 1) A device for controlling the operation of a vehicle lamp capable of variably setting light distribution, comprising: A controller connected to the vehicle lamp, The controller controls the vehicle lamp to emit a low beam, and controls the vehicle lamp to emit an additional beam to a predetermined range in front of the vehicle when a signal strength of a first frequency band set within a range of 0.3 Hz to 0.6 Hz in a frequency analysis result of a steering angle signal acquired from the vehicle exceeds a reference value. A control device for vehicle lighting. (Appendix 2) The reference value is a value previously obtained as an average value of the signal strength of the first frequency band in a result of frequency analysis of the steering angle signal during the daytime. 2. A control device for a vehicle lamp as described in appendix 1. (Appendix 3) The reference value is a value set based on the signal strength of a second frequency band set within a range smaller than 0.3 Hz in a frequency analysis result of the steering angle signal. 2. A control device for a vehicle lamp as described in appendix 1. (Appendix 4) the first frequency band is in the range of 0.3 Hz to 0.6 Hz; The second frequency band is in the range of 0.1 Hz to 0.2 Hz. 4. A control device for a vehicle lamp as described in appendix 3. (Appendix 5) The predetermined range is set to a range of 5 m to 40 m in front of the vehicle. 5. A control device for a vehicle lamp according to any one of claims 1 to 4. (Appendix 6) The predetermined range is set to a width equal to or greater than the width of the lane on which the vehicle is traveling. 6. A control device for a vehicle lamp as described in appendix 5. (Appendix 7) The additional beam is irradiated so that the illuminance at a reference position within the predetermined range is 1.2 to 1.5 times that of a case in which the low beam is irradiated without irradiating the additional beam. 7. A control device for a vehicle lamp according to any one of claims 1 to 6. (Appendix 8) A method for controlling an operation of a vehicle lamp capable of variably setting a light distribution, comprising: a control unit that controls the vehicle lamp to emit a low beam, and controls the vehicle lamp to emit an additional beam in a predetermined range in front of the vehicle when a signal strength of a frequency band set in a range of 0.3 Hz to 0.6 Hz in a frequency analysis result of a steering angle signal acquired from the vehicle exceeds a reference value; A method for controlling a vehicle lamp. (Appendix 9) A control device for a vehicle lamp according to any one of appendixes 1 to 7, A vehicle lamp controlled by the vehicle lamp control device; A vehicle lighting system comprising: [Explanation of symbols]

[0036] 10: controller, 11: steering angle sensor, 21: signal analysis unit, 22: light distribution setting unit, 23: control signal generation unit, 31: low beam unit, 32: high beam unit, 33: additional beam unit, 100: host vehicle, 101: high beam, 102: additional beam

Claims

1. A device for controlling the operation of a vehicle lamp capable of variably setting light distribution, comprising: A controller connected to the vehicle lamp, The controller controls the vehicle lamp to emit a low beam, and controls the vehicle lamp to emit an additional beam to a predetermined range in front of the vehicle when a signal strength of a first frequency band set in a range of 0.3 Hz to 0.6 Hz in a frequency analysis result of a steering angle signal acquired from the vehicle exceeds a reference value. A control device for vehicle lighting.

2. the reference value is a value calculated in advance as an average value of the signal strength of the first frequency band in a result of frequency analysis of the steering angle signal during daytime; The vehicle lighting control device according to claim 1 .

3. the reference value is a value set based on a signal strength of a second frequency band set within a range smaller than 0.3 Hz in a result of frequency analysis of the steering angle signal; The vehicle lighting control device according to claim 1 .

4. the first frequency band is in the range of 0.3 Hz to 0.6 Hz; The second frequency band is in the range of 0.1 Hz to 0.2 Hz. The vehicle lamp control device according to claim 3.

5. The predetermined range is set to a range of 5 m to 40 m in front of the vehicle. The vehicle lighting control device according to claim 1 .

6. The predetermined range is set to a width equal to or greater than the width of the lane on which the vehicle is traveling. The vehicle lamp control device according to claim 5.

7. The additional beam is irradiated so that the illuminance at a reference position within the predetermined range is 1.2 to 1.5 times that in the case where the low beam is irradiated without irradiating the additional beam. The vehicle lighting control device according to claim 1 .

8. A method for controlling an operation of a vehicle lamp capable of variably setting a light distribution, comprising: a control unit that controls the vehicle lamp to emit a low beam, and controls the vehicle lamp to emit an additional beam in a predetermined range in front of the vehicle when a signal strength of a frequency band set in a range of 0.3 Hz to 0.6 Hz in a frequency analysis result of a steering angle signal acquired from the vehicle exceeds a reference value; A method for controlling a vehicle lamp.

9. The vehicle lighting control device according to claim 1 ; A vehicle lamp controlled by the vehicle lamp control device; A vehicle lighting system comprising:

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