Control device for vehicle lamp, control method for vehicle lamp, and vehicle lamp system

Abstract

Light distribution corresponding to the steering state of a driver is realized. A vehicle lamp control device for controlling the operation of a vehicle lamp in which light distribution can be variably set, the vehicle lamp control device having a controller connected to the vehicle lamp, the controller performing control so that the vehicle lamp irradiates low beams, and the controller being connected to the vehicle lamp. And when the signal intensity of a first frequency band set in the range of 0.3 Hz to 0.6 Hz exceeds a reference value in the frequency analysis result of a steering angle signal acquired from the vehicle, the control unit controls the vehicle lamp so as to irradiate an additional light beam to a predetermined range in front of the vehicle.

Description

Technical Field

[0001] This disclosure relates to control devices for vehicle lighting fixtures, control methods for vehicle lighting fixtures, and vehicle lighting fixture systems. Background Technology

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

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent No. 3768624 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] One of the specific purposes of this disclosure is to provide a technology that can achieve light distribution that corresponds to the driver's steering state.

[0008] Methods for solving problems

[0009] [1] One aspect of the vehicle lamp control device disclosed herein is a device for controlling the operation of a vehicle lamp whose light distribution can be variably set, wherein,

[0010] The control device for the vehicle lights includes a controller connected to the vehicle lights.

[0011] The controller controls the vehicle lights to illuminate with low beams, and if the signal strength of a first frequency band set in the range of 0.3 Hz to 0.6 Hz, as determined by frequency analysis of the steering angle signal obtained from the vehicle, exceeds a reference value, the controller controls the vehicle lights to illuminate an additional beam of light in a predetermined range in front of the vehicle.

[0012] [2] One aspect of the present disclosure is a method for controlling a vehicle lamp, wherein the operation of a vehicle lamp with variablely set light distribution is controlled.

[0013] The method for controlling the vehicle lights allows the vehicle lights to illuminate low beams. Furthermore, if the signal strength of a frequency band set between 0.3 Hz and 0.6 Hz, as determined by frequency analysis of the steering angle signal obtained from the vehicle, exceeds a reference value, the method controls the vehicle lights to illuminate an additional beam within a predetermined range in front of the vehicle.

[0014] [3] One aspect of the vehicle lighting system disclosed herein includes:

[0015] The control device for vehicle lighting described above [1]; and

[0016] Vehicle lighting fixtures, which are controlled by a control device for the vehicle lighting fixtures.

[0017] Based on the above structure, it is possible to achieve light distribution that corresponds to the driver's steering state. Attached Figure Description

[0018] Figure 1 (A) is a block diagram showing the structure of a vehicle lighting system according to one embodiment. Figure 1 (B) is a diagram showing an example of the structure of a computer system.

[0019] Figure 2 It is a diagram used to illustrate the illumination light of a headlight.

[0020] Figure 3 This is a diagram illustrating the illuminance distribution of the headlight beam across a cross section in the direction of vehicle travel.

[0021] Figure 4 (A) is a diagram schematically showing the steering angle signal. Figure 4 (B) is a schematic diagram showing the power spectrum obtained by performing a fast Fourier transform on the steering angle signal.

[0022] Figure 5 This is a flowchart illustrating the sequence of operations of a vehicle lighting system. Detailed Implementation

[0023] Figure 1 (A) is a block diagram illustrating the structure of a vehicle lighting system according to one embodiment. The illustrated vehicle lighting system is configured to include a controller 10, a steering angle sensor 11, and a pair of headlights (vehicle lighting fixtures) 12L and 12R. This vehicle lighting system is used to illuminate the area in front of the vehicle.

[0024] The controller 10 controls the illumination operation of each headlight 12L, 12R. This controller 10 can, for example, use... Figure 1The computer system shown in (B) is configured as such, that is, a computer system equipped with a processor (CPU: Central Processing Unit) 201, ROM (Read-Only Memory) 202, RAM (Random Access Memory) 203, a storage device 204 such as flash memory, and an input / output interface 205. In this embodiment, the controller 10 is able to perform the functions described later by reading and executing a program 206 pre-stored in the storage device 204 by the processor.

[0025] Steering angle sensor 11 detects the rotation angle of the steering system, which rotates in conjunction with the vehicle's steering wheel, i.e., the steering angle, and outputs a steering angle signal (steering angle data) corresponding to its magnitude.

[0026] The controller 10 includes a signal analysis unit 21, a light distribution setting unit 22, and a control signal generation unit 23, which are function blocks implemented by program execution.

[0027] Signal analysis unit 21 performs a prescribed frequency analysis on the steering angle signal output from steering angle sensor 11 over time. Specifically, it performs a fast Fourier transform to obtain the power spectrum for each prescribed frequency range (see description below). Figure 4 (B)

[0028] The light distribution setting unit 22 sets the light distribution pattern of the illumination light of each headlamp 12L and 12R based on the frequency analysis results of the signal analysis unit 21.

[0029] The control signal generation unit 23 generates a control signal for each headlamp 12L, 12R to form an illumination light corresponding to the light distribution pattern set by the light distribution setting unit 22, and provides it to each headlamp 12L, 12R.

[0030] A pair of headlights 12L and 12R are mounted at predetermined positions on the left and right sides of the front of the vehicle, and operate according to control signals provided by the controller 10 to generate light illuminating the front of the vehicle. In this embodiment, the headlight units 12L and 12R can be variably configured with light distribution patterns, and are respectively configured to include a low beam unit 31 for illuminating low beams (meeting lights), a high beam unit 33 for illuminating high beams (driving lights), and a unit for [other functions described later]. Figure 2 The example low beam 101 illuminates the additional beam 102 within its illumination range. The high beam unit 33 may also be an ADB unit capable of creating a light reduction range (or light blocking range) based on the position of vehicles ahead, etc.

[0031] Various known structures can be used for the 12L and 12R headlights. For example, a lamp unit that combines a light bulb, a reflector, and a shield can generate high beam, low beam, and additional beam. Alternatively, a lamp unit can be used where light-emitting elements such as LEDs (Light Emitting Diodes) are arranged in one or two directions and the illumination state of each element can be controlled individually. Another lamp unit can be used that includes a light source and a liquid crystal element, allowing individual control of the light transmission state of each pixel of the liquid crystal element. Furthermore, a lamp unit can be used that includes a laser diode or other light-emitting element and a scanning element such as a reflector that scans the light emitted from the light-emitting element, allowing control of the timing of the light-emitting element's on / off state and the scanning timing of the scanning element.

[0032] Figure 2 This diagram illustrates the illumination of the headlights. Here, a view of the vehicle from above is shown schematically. As shown, the low beam 101 illuminates the vehicle 100 from its front. In the illustrated example, the outer edge of the low beam 101 is at a position equivalent to 5 lx (lux). Additionally, when the power spectrum of the steering angle signal meets specified conditions, an additional beam 102 illuminates the vehicle 100 from its front. This additional beam 102 illuminates within the illumination range of the low beam 101 and within a specified range in front of the vehicle 100, specifically, for example, within a range of 5m to 40m (5m to 35m in the illustrated example). Furthermore, the additional beam 102 illuminates the area of ​​the driving lane including the vehicle 100. For example, the additional beam 102 illuminates with a width equal to or greater than the width W of the driving lane (e.g., approximately 3.5m).

[0033] Figure 3 This is a diagram illustrating the illuminance distribution of the headlight beam in a cross-section along the vehicle's direction of travel. In the diagram, solid lines represent the illuminance when only the low beam 101 is illuminated, and dashed lines represent the illuminance when the additional beam 102 is illuminated. As described above, the additional beam 102 illuminates a predetermined range (for example, 5m to 40m) in front of the vehicle 100 within the illumination range of the low beam 101. At this time, within this predetermined range in front, the additional beam 102 is illuminated with a brightness 1.2 to 1.5 times that of the low beam 101, without illuminating the additional beam 102, based on the case where the low beam 101 is illuminated but not the additional beam 102. The distance d1 in front of the position where the illuminance is greatest when the additional beam 102 is illuminated can be set, for example, to 20m to 30m.

[0034] Figure 4 (A) is a schematic diagram illustrating the steering angle signal. Additionally, Figure 4 (B) is a schematic diagram showing the power spectrum obtained by performing a fast Fourier transform on the steering angle signal. Figure 4As shown in (A), the steering angle signal changes over time according to the driver's steering wheel operation. In this embodiment, a Fast Fourier Transform is performed on the steering angle signal to calculate the signal strength (power) at each frequency. Then, as... Figure 4 As shown in (B), the signal strength in the 0.1Hz to 0.2Hz frequency band and the signal strength in the 0.3Hz to 0.6Hz frequency band are summarized respectively.

[0035] Here, we explain the reason for summarizing the signal strength in the 0.1Hz–0.2Hz band and the 0.3Hz–0.6Hz band, respectively. According to the paper by McLean and Hoffmann, the frequency of the steering angle signal during driving is mostly below 1Hz; therefore, the 0.1Hz–0.2Hz band corresponds to preview steering, and the 0.3Hz–0.6Hz band corresponds to compensation steering. Therefore, in this embodiment, by summarizing the signal strength in the 0.1Hz–0.2Hz band and the 0.3Hz–0.6Hz band, information that allows us to understand the driver's state is obtained.

[0036] (1)McLean, JR and Hoffmann, ER (1971). Analysis of drivers' control movements. Human Factors, 13, 407-418.

[0037] (2)McLean, JR and Hoffmann, ER (1973). The effects of restricted preview on driver steering control and performance. Human Factors, 15, 421-430.

[0038] Furthermore, according to the following paper, research results show that if the driver's lateral task requirements for the vehicle increase, the peak value of the steering angle signal shifts towards the 0.3Hz to 0.6Hz band. Here, "task" refers to keeping the vehicle in the center of its lane (or the driving trajectory the driver intends to take).

[0039] (3) Blaauw, GJ (1984). Car driving as a supervisory control task. Soesterberg, The Netherlands: Institute for Perception TNO.

[0040] In other words, since the driver's driving load is reflected in the steering angle signal, the driver's driving load status can be investigated by performing frequency analysis on the steering angle signal. Furthermore, an increase in the 0.3Hz–0.6Hz frequency band components in the steering angle signal indicates insufficient adjustment in the prior steering operation (preview steering occurring at 0.1Hz–0.2Hz), resulting in increased compensating steering input. This can be interpreted as a situation where the driver cannot accurately identify the vehicle's driving position.

[0041] On the other hand, the following survey results were also disclosed (UMTRI Report 2002-3): When comparing a vehicle equipped with HID lamps that have a brighter beam distribution near the front of the vehicle and a vehicle equipped with tungsten halogen lamps that have a dimmer beam distribution near the front, the vehicle with the brighter beam distribution near the front is easier to drive (i.e., easier to perceive linearly). Therefore, it is anticipated that by ensuring the brightness of the beam distribution near the front of the vehicle, the driver can more easily judge the vehicle's driving position.

[0042] Therefore, in this embodiment, when the signal strength in the 0.3Hz to 0.6Hz frequency band corresponding to the compensation steering exceeds a predetermined threshold, the additional beam 102 (see reference) is used to... Figure 2 It illuminates a specified area in front of the vehicle to assist the driver in determining the vehicle's position.

[0043] Figure 5 This is a flowchart illustrating the sequence of operations of a vehicle's lighting system. Furthermore, the order of the processes shown here can be rearranged as long as they do not result in contradictions or mismatches in the information processing results. Additionally, other processes not explicitly shown here can be added. Moreover, while mentions of high beams are omitted in the following description, the appropriate application of high beams will be discussed.

[0044] The light distribution setting unit 22 of the controller 10 obtains the signal strength of each frequency of the steering angle signal obtained by the signal analysis unit 21. If the signal strength in the frequency band (first frequency band) of 0.3Hz to 0.6Hz does not exceed a predetermined threshold (step S11; no), the light distribution setting unit 22 sets the current light distribution pattern, that is, sets the light distribution pattern that maintains the state of irradiating the near beam without irradiating the additional beam (step S12). Then, it returns to step S11.

[0045] Here, the threshold in step S11 can be set as follows. For example, the average signal strength of the 0.3Hz to 0.6Hz frequency band during normal times (e.g., daytime) can be obtained through experiments, and the threshold can be set based on that result. As another example, the signal strength of the 0.1Hz to 0.2Hz frequency band (the second frequency band) obtained simultaneously can be used as the threshold. That is, whether the relationship between the signal strength of the first frequency band and the signal strength of the second frequency band holds can be used as a criterion for judgment.

[0046] When the signal strength in the 0.3Hz to 0.6Hz frequency band exceeds a predetermined threshold (step S11; Yes), the light distribution setting unit 22 switches the setting of the headlight's illumination light light to illuminate an additional beam in addition to the low beam (step S13). As a result, the additional beam 102 is illuminated.

[0047] Then, if the signal strength in the 0.3Hz to 0.6Hz frequency band continues to exceed a predetermined threshold (step S14; Yes), the light distribution setting unit 22 sets a light distribution pattern to maintain the illumination of the additional beam (step S15). Then, it returns to step S14. That is, during the period when the signal strength in the 0.3Hz to 0.6Hz frequency band continues to exceed the predetermined threshold, the illumination of the additional beam continues.

[0048] On the other hand, if the state of signal strength exceeding the predetermined threshold in the 0.3Hz to 0.6Hz frequency band no longer continues (step S14; no), the light distribution setting unit 22 restores the setting of the light distribution pattern to its original state, that is, the state of illuminating near light without illuminating the additional beam (step S16). Then, it returns to step S11.

[0049] According to the above implementation method, when compensating for increased steering input, that is, when it is presumed that the driver cannot correctly identify the vehicle's driving position, an additional beam is irradiated in addition to the low beam within a specified range in front of the vehicle, thus enabling the light distribution to correspond to the driver's steering state.

[0050] Furthermore, this disclosure is not limited to the embodiments described above, and various modifications can be made within the scope of the spirit of this disclosure. For example, in the above embodiments, the frequency band of the steering angle signal is divided into a first frequency band of 0.3Hz to 0.6Hz and a second frequency band of 0.1Hz to 0.2Hz, but these values ​​are merely examples and are not limited thereto. Specifically, the first frequency band can be in the range of 0.3Hz to 0.6Hz, for example, set to 0.3Hz to 0.5Hz, and the second frequency band can be appropriately set in a range less than 0.3Hz.

[0051] This disclosure has the following features.

[0052] (Note 1)

[0053] A control device for vehicle lighting fixtures, which is used to control the operation of vehicle lighting fixtures with variable light distribution settings.

[0054] The control device for the vehicle lights includes a controller connected to the vehicle lights.

[0055] The controller controls the vehicle lights to illuminate with low beams, and if the signal strength of a first frequency band set in the range of 0.3 Hz to 0.6 Hz, as determined by frequency analysis of the steering angle signal obtained from the vehicle, exceeds a reference value, the controller controls the vehicle lights to illuminate an additional beam of light in a predetermined range in front of the vehicle.

[0056] (Note 2)

[0057] According to the control device for vehicle lights described in Appendix 1

[0058] The reference value is a value pre-calculated as the average signal strength of the first frequency band from the frequency analysis results of the steering angle signal during the day.

[0059] (Note 3)

[0060] According to the control device for vehicle lighting as described in Appendix 1, the reference value is a value set based on the signal strength of the second frequency band set in the range of less than 0.3 Hz in the frequency analysis results of the steering angle signal.

[0061] (Note 4)

[0062] The control device for vehicle lights as described in Appendix 3

[0063] The first frequency band is in the range of 0.3Hz to 0.6Hz.

[0064] The second frequency band is in the range of 0.1Hz to 0.2Hz.

[0065] (Note 5)

[0066] Control device for vehicle lights according to any one of Appendices 1 to 4

[0067] The specified range is defined as a distance of 5m to 40m in front of the vehicle.

[0068] (Note 6)

[0069] The control device for vehicle lights as described in Appendix 5

[0070] The specified range is defined as the width above the driving lane width of the vehicle.

[0071] (Note 7)

[0072] Control device for vehicle lighting according to any one of Appendices 1 to 6

[0073] The additional beam is irradiated such that the illuminance at the reference position within the specified range is 1.2 times greater and 1.5 times less than that of the low beam without irradiating the additional beam.

[0074] (Note 8)

[0075] A method for controlling vehicle lighting fixtures, which is a method for controlling the operation of vehicle lighting fixtures whose light distribution can be variably set.

[0076] The method for controlling the vehicle lights allows the vehicle lights to illuminate low beams. Furthermore, if the signal strength of a frequency band set between 0.3 Hz and 0.6 Hz, as determined by frequency analysis of the steering angle signal obtained from the vehicle, exceeds a reference value, the method controls the vehicle lights to illuminate an additional beam within a predetermined range in front of the vehicle.

[0077] (Note 9)

[0078] A vehicle lighting system comprising:

[0079] Control device for vehicle lamps as described in any one of Annexes 1 to 7; and

[0080] Vehicle lighting fixtures, which are controlled by a control device for the vehicle lighting fixtures.

[0081] Explanation of reference numerals in the attached figures

[0082] 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: This vehicle; 101: High beam; 102: Additional beam

Claims

1. A control device of a vehicle lamp, which is a device for controlling an operation of a vehicle lamp capable of variably setting a distribution of light, wherein the control device of the vehicle lamp comprises a controller connected to the vehicle lamp, the controller controls the vehicle lamp to irradiate low beam, and in a case where a signal intensity of a first frequency band set in a range of 0.3 Hz or more and 0.6 Hz or less in a frequency analysis result of a steering angle signal obtained from a vehicle exceeds a reference value, controls the vehicle lamp to irradiate an additional light beam to a prescribed range in front of the vehicle.

2. The control device of the vehicle lamp according to claim 1, wherein the reference value is a value previously calculated as an average value of the signal intensity of the first frequency band in the frequency analysis result of the steering angle signal in daytime.

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

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

5. The control device of the vehicle lamp according to claim 1, wherein the prescribed range is set to a range of 5 m or more and 40 m or less in front of the vehicle.

6. The control device of the vehicle lamp according to claim 5, wherein the prescribed range is set to a width of a width of a travel lane of the vehicle or more.

7. The control device of the vehicle lamp according to claim 1, wherein the additional light beam is irradiated so that an illuminance at a reference position in the prescribed range becomes 1.2 times or more and 1.5 times or less compared to a case where the additional light beam is not irradiated and the low beam is irradiated.

8. A control method of a vehicle lamp, which is a method for controlling an operation of a vehicle lamp capable of variably setting a distribution of light, wherein in the control method, the vehicle lamp is controlled to irradiate low beam, and in a case where a signal intensity of a frequency band set in a range of 0.3 Hz or more and 0.6 Hz or less in a frequency analysis result of a steering angle signal obtained from a vehicle exceeds a reference value, the vehicle lamp is controlled to irradiate an additional light beam in a prescribed range in front of the vehicle.

9. A vehicle lamp system comprising: the control device of the vehicle lamp according to claim 1; and the vehicle lamp controlled by the control device of the vehicle lamp. ​ ​ ​ ​ ​ ​ ​ ​

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