Optical axis control device for vehicle lighting, optical axis control method for vehicle lighting, vehicle lighting system

Abstract

To provide a vehicle headlight optical axis control device capable of shortening a time until optical axis control based on an accurate vehicle angle can be performed.SOLUTION: A controller uses output of a gyro sensor to obtain a pitch angle of a vehicle, and when an amount of change in the pitch angle is smaller than a predetermined reference value, calculates gravity acceleration components corresponding to at least a longitudinal direction and a vertical direction of the vehicle using the pitch angle, removes each of the gravity acceleration components from acceleration corresponding to the longitudinal direction and the vertical direction of the vehicle obtained by using the output of an acceleration sensor, and controls an optical axis of a headlight using the acceleration corresponding to the longitudinal direction and the vertical direction of the vehicle after removing each of the gravity acceleration components.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] This disclosure relates to a light axis control device for vehicle lighting, a method for controlling the light axis of vehicle lighting, and a vehicle lighting system. [Background technology]

[0002] Japanese Patent Publication No. 2019-073189 (Patent Document 1) describes an auto-leveling technology that variably controls the optical axis of the headlights in response to changes in the vehicle's attitude due to occupants, cargo, etc., and describes a technique to remove the gravitational acceleration component from the acceleration detected by an acceleration sensor in order to improve the accuracy of calculating the vehicle angle for optical axis control. However, in this conventional example, the gravitational acceleration component is acquired when the vehicle is in a constant speed state (vehicle speed change amount 0 km / h), but depending on the driving conditions, it may take time to reach a constant speed state. For this reason, it may take time to be able to perform optical axis control based on an accurate vehicle angle. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2019-073189 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] One of the specific aspects of this disclosure aims to shorten the time required to achieve accurate optical axis control based on vehicle angle when using auto-leveling technology. [Means for solving the problem]

[0005] [1] A headlight beam control device for a vehicle according to one embodiment of the present disclosure is a device for controlling the beam of a headlight mounted on a vehicle, comprising: (a) an acceleration sensor installed on the vehicle; (b) a gyro sensor installed on the vehicle; and (c) a controller connected to the acceleration sensor and the gyro sensor, respectively, wherein the controller (d1) determines the pitch angle of the vehicle using the output of the gyro sensor; (d2) if the amount of change in the pitch angle is smaller than a predetermined reference value, calculates a gravitational acceleration component corresponding to at least the longitudinal and vertical directions of the vehicle using the pitch angle; (d3) removes each of the gravitational acceleration components from each of the accelerations corresponding to the longitudinal and vertical directions of the vehicle obtained using the output of the acceleration sensor; and (d4) controls the beam of the headlight using the accelerations corresponding to the longitudinal and vertical directions of the vehicle after the gravitational acceleration components have been removed. [2] One embodiment of a vehicle lighting system relating to the present disclosure is a vehicle lighting system comprising the optical axis control device described in [1] above and a headlight controlled by the optical axis control device.

[0006] According to the above configuration, when using auto-leveling technology, it becomes possible to shorten the time required to achieve accurate optical axis control based on the vehicle angle. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 shows the configuration of a vehicle lighting system according to one embodiment. [Figure 2] Figure 2 is a schematic diagram showing an example of the configuration of a lamp unit. [Figure 3] Figure 3 shows an example of a computer configuration for implementing a vehicle lighting system controller. [Figure 4] Figure 4(A) is a schematic diagram illustrating the angle of a moving vehicle. Figure 4(B) is a diagram illustrating the output of an acceleration sensor corresponding to the state shown in Figure 4(A). [Figure 5]Figure 5 is a diagram illustrating the breakdown of the vehicle's pitch angle obtained using a gyro sensor. [Figure 6] Figure 6 is a schematic waveform diagram showing an example of the change in pitch angle when a vehicle is traveling on a flat road. [Figure 7] Figures 7(A) and 7(B) are schematic waveform diagrams illustrating other examples of changes in pitch angle when a vehicle is traveling on a flat road. [Figure 8] Figure 8 is a flowchart showing the operating procedure of a vehicle lighting system. [Modes for carrying out the invention]

[0008] Figure 1 shows the configuration of a vehicle lighting system according to one embodiment. This vehicle lighting system adjusts the optical axis according to the vehicle's attitude to provide light illumination, and includes a controller 10, a gyro sensor 11, an acceleration sensor 12, a memory 13, and a pair of lamp units 30L and 30R.

[0009] The controller 10 is used to control the operation of the vehicle lighting system and is configured using, for example, a computer system capable of executing a predetermined operation program. Here, the functions realized by the controller 10 will be explained using functional blocks to make them easier to understand. The controller 10 has an attitude angle calculation unit 21, a vehicle state output unit 22, a gravity acceleration component processing unit 23, and an optical axis control unit 24. The controller 10 also receives signals or data indicating the vehicle's speed. The vehicle speed is detected by sensors (not shown) installed in the vehicle and obtained, for example, in the form of a vehicle speed pulse signal or vehicle speed data.

[0010] The gyro sensor 11 is a sensor (angular velocity sensor) that detects an angular velocity and outputs data or a signal according to its magnitude. The gyro sensor 11 of the present embodiment can detect angular velocities corresponding to the roll angle, pitch angle, and yaw angle of the vehicle. The gyro sensor 11 is installed at a predetermined position of the vehicle (for example, the back side of the glove box, etc.). Note that the roll direction is the direction of rotation around the longitudinal axis of the vehicle, the pitch direction is the direction of rotation around the lateral axis of the vehicle, and the yaw direction is the direction of rotation around the vertical axis of the vehicle.

[0011] The acceleration sensor 12 is a sensor that detects an acceleration and outputs data or a signal according to its magnitude. The acceleration sensor 12 of the present embodiment can detect accelerations corresponding to each of the longitudinal direction, vertical direction, and lateral direction of the vehicle. Note that each axis of the acceleration sensor 12 does not necessarily have to exactly coincide with each of the longitudinal direction, vertical direction, and lateral direction of the vehicle. In that case, correction processing may be appropriately performed on the detected values.

[0012] The memory 13 is connected to the controller 10 and stores data necessary for the arithmetic processing by the controller 10.

[0013] The attitude angle calculation unit 21 detects the attitude angle (pitch angle, roll angle, yaw angle) of the vehicle based on the data (or signal, the same applies hereinafter) output from the gyro sensor 11, and outputs data (or signal, the same applies hereinafter) according to its magnitude.

[0014] The vehicle state output unit 22 determines the vehicle state based on the pitch angle calculated by the attitude angle calculation unit 21, and supplies data (or signal, the same applies hereinafter) indicating the vehicle state to the gravitational acceleration component processing unit 22. In the present embodiment, the vehicle state output unit 22 outputs data indicating either a "stable" or "unstable" state of the pitch angle as the vehicle state. [[ID=]18]

[0015] The gravitational acceleration component processing unit 23 performs a process of removing the gravitational acceleration component from the acceleration data detected by the acceleration sensor 12, and provides the processed acceleration data to the optical axis control unit 24.

[0016] Based on the acceleration data output from the gravitational acceleration component processing unit 23, the optical axis control unit 24 obtains the vehicle angle (the angle obtained by excluding the road surface angle from the pitch angle), generates a control signal for controlling the optical axis of the irradiation light of each lamp unit 30L and 30R according to this vehicle angle, and supplies (outputs) it to each lamp unit 30L and 30R. At this time, the optical axis control unit 24 appropriately selects an arithmetic method according to the vehicle state output from the vehicle state output unit 22, and applies the selected arithmetic method to obtain the vehicle angle. A known method can be used as the arithmetic method for the vehicle angle.

[0017] Each lamp unit 30L and 30R is provided one by one on the left and right of the front part of the vehicle, and is for performing light irradiation in front of the vehicle. As each lamp unit 30L and 30R, various known lamp units can be adopted. For example, a lamp unit having a light source unit configured with a light source, a reflector, etc., and an actuator for adjusting the orientation of the light source unit up and down in the pitch direction of the vehicle to adjust the optical axis (main traveling direction) of the light emitted from the light source unit up and down can be used, and a lamp unit whose light irradiation range can be mechanically controlled can be used (see FIG. 2 described later). Note that as each lamp unit 30L and 30R, for example, a lamp unit having a configuration in which a light irradiation range can be controlled by combining a light source and a liquid crystal element, a lamp unit having a configuration in which a light irradiation range can be controlled by selectively lighting / extinguishing a plurality of LEDs, a lamp unit having a configuration in which the light from a laser element is scanned by a movable reflector and the laser element is rapidly turned on and off at that time to control the light irradiation range, etc., a lamp unit whose light irradiation range can be electronically controlled can also be used.

[0018] Figure 2 is a schematic diagram showing an example of the configuration of a lamp unit. In this embodiment, the headlight units 30L and 30R, as an example, each include a light source 31, a housing 33 that houses the light source 31, and a lens 34 that is positioned in front of the light source 31 (in the direction from which the light is emitted) and fixed to the housing 33. The inner surface of the housing 33 is provided with a reflective surface that reflects the 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 orientation of the housing 33. This makes it possible to set the optical axis a of the light from the light source 31 to be variable. For example, when the rear of the vehicle is relatively lower, the optical axis a is controlled to point downward, and when the front of the vehicle is relatively lower, the optical axis a is controlled to point upward. The degree to which it is pointed downward or upward is set according to the vehicle angle.

[0019] Figure 3 shows an example of the configuration of a computer that implements a controller for a vehicle lighting system. The illustrated computer consists of a CPU (Central Processing Unit) 201, ROM (Read Only Memory) 202, RAM (Random Access Memory) 203, storage device 204, and external interface (I / F) 205, all of which are connected to each other for communication. The CPU 201 operates based on a basic control program read from the ROM 202, and implements the functions of the controller 10 described above by reading and executing a program (application program) 206 stored in the storage device 204. The RAM 203 temporarily stores data to be used when the CPU 201 is operating. The storage device 204 is a non-volatile storage device such as a hard disk or solid-state drive, and stores various data such as the program 206. The external interface 205 is an interface that connects the CPU 201 to an external device.

[0020] Figure 4(A) is a schematic diagram illustrating the angle of a moving vehicle. Figure 4(B) is a diagram illustrating the output of an acceleration sensor corresponding to the state shown in Figure 4(A). Assume that vehicle 100 is traveling on road surface 101 as shown in Figure 4(A). Assume that road surface 101 is tilted at an angle θz with respect to the horizontal. Hereafter, this angle will be referred to as the road surface angle θz. Assume that vehicle 100 is also tilted at an angle θk with respect to road surface 101 depending on the condition of the load, etc. In the illustrated example, vehicle 100 is tilted backward, but it may also be tilted forward. Angle θk corresponds to the vehicle angle described above, and hereafter will simply be referred to as the vehicle angle θk.

[0021] As shown in Figure 4(A), assume that vehicle 100 is traveling on a road surface 101 with a road surface angle θz while accelerating. At this time, the X-axis (axis corresponding to the vehicle's longitudinal direction) and Z-axis (axis corresponding to the vehicle's vertical direction) of the acceleration sensor 12 are tilted in accordance with the change in the vehicle angle θk. On the other hand, the acceleration vector A generated by acceleration is not affected by the vehicle angle θk and is parallel to the road surface 101 indicated by the road surface angle θz. At this time, the output values ​​(output data or output signal) of the X-axis and Z-axis components of the acceleration sensor 12 can be expressed as follows. In the equation, "G" represents the acceleration due to gravity (the same applies below). X=-Gsin(θk+θz)-Acosθk ···(1) Z= Gcos(θk+θz)-Asinθk (2)

[0022] Here, if the vehicle 100 is moving at a constant speed (no change in vehicle speed), the acceleration vector A is 0. Therefore, the output values ​​X0 and Z0 of the X-axis and Z-axis components of the acceleration sensor 12 can be expressed as follows, based on equations (1) and (2) above. X0 = -Gsin(θk + θz) ... (3) Z0 = Gcos(θk+θz) ···(4)

[0023] The values ​​expressed by equations (3) and (4) above correspond to the gravitational acceleration component. That is, the gravitational acceleration components X0 and Z0 are expressed by a relational expression that includes the vehicle angle θk and the road surface angle θz. Therefore, if it can be detected that the vehicle 100 is in a constant speed state, the gravitational acceleration component can be obtained from the output value of the acceleration sensor 12. However, if, for example, an attempt is made to determine whether the vehicle 100 is in a constant speed state based on the vehicle speed obtained from the vehicle speed sensor (not shown) of the vehicle 100, a time difference will occur between the timing at which the gravitational acceleration component is obtained and the timing at which it is obtained, resulting in a decrease in the accuracy of the gravitational acceleration component. For this reason, in this embodiment, the constant speed state of the vehicle 100 is detected using the output value of the gyro sensor 11, as described below.

[0024] Figure 5 is a diagram illustrating the breakdown of the vehicle's pitch angle obtained using a gyro sensor. The gyro sensor 11 detects angular velocities corresponding to the vehicle's pitch, roll, and yaw directions, and by integrating (summarizing) these, the vehicle's pitch angle and other parameters can be determined. Furthermore, the accuracy of the calculation of the pitch angle and other parameters can be improved by applying corrections using various known filters (e.g., a Madgwick filter). As shown in the figure, the pitch angle θp, which is the angle in the longitudinal direction of the vehicle, includes the road surface angle θz and vehicle angle θk mentioned above, as well as the angle θud, which is a temporary angular change caused by head-up and head-down due to the vehicle's acceleration and deceleration. These relationships can be expressed as follows. θp = θz + θk + θud ... (5)

[0025] Here, θud is a temporary phenomenon caused by the acceleration generated in the longitudinal direction of the vehicle when the accelerator or brake is pressed while the vehicle is in motion. When the vehicle is traveling at constant acceleration, θud is maintained, but when the vehicle is traveling at a constant speed, the effect of acceleration disappears, and θud = 0. In other words, at a constant speed, θp = θz + θk.

[0026] The angle corresponding to the gravitational acceleration component is determined from the obtained pitch angle. The gravitational acceleration component can be determined from the angle θ0 which includes the road surface angle θz and the vehicle angle θk. In principle, the vehicle angle θk does not change during driving because there is no boarding or alighting of people or loading of luggage into the vehicle. Therefore, the change in pitch angle during driving is due to the change in the road surface angle θz or the angle θud due to the vehicle's acceleration. Accordingly, if a pitch angle θp can be obtained without the influence of these angle changes that may occur during driving, this pitch angle θp can be used as the angle θ0 corresponding to the gravitational acceleration component.

[0027] By using the angle θ0 corresponding to the gravitational acceleration component described above, and the roll angle θr obtained using the gyro sensor 11, the gravitational acceleration components X0, Y0, and Z0 corresponding to each of the X, Y, and Z axes can be determined as follows. X0 is the gravitational acceleration component corresponding to the longitudinal direction (direction of travel) of the vehicle, Y0 is the gravitational acceleration component corresponding to the lateral direction of the vehicle, and Z0 is the gravitational acceleration component corresponding to the vertical direction of the vehicle. Note that the roll angle θr is the angle in the roll direction of the vehicle. X0 = Gsinθ0 ···(6) Y0 = Gcosθ0sinθr ···(7) Z0 = Gcosθ0cosθr ···(8)

[0028] Figure 6 is a schematic waveform diagram showing an example of pitch angle change when a vehicle is traveling on a flat road. As mentioned above, the gravitational acceleration component can be obtained when the pitch angle is stable, that is, when there is no influence from angle changes during travel. Therefore, it is possible to detect when the pitch angle is stable and obtain the angle corresponding to the gravitational acceleration component at that time. Specifically, the following three patterns are possible when the pitch angle is stable. (a) Small change in pitch angle (b) There are instantaneous changes (jumps) in the pitch angle, but the amount of change is relatively small. (c) After changing due to changes in road surface angle, etc., the amount of change is small.

[0029] Period a in Figure 6 corresponds to the period corresponding to condition (a) described above, and period b corresponds to the period corresponding to condition (b) described above. In Figure 6, one cell on the horizontal axis corresponds to 0.2s, and one cell on the vertical axis corresponds to 0.01deg. In period a, the change in pitch angle is a small amount, less than 0.01deg. In period b, there are gaps in the values ​​at the four locations circled, and while each location cannot be considered stable if viewed instantaneously, it can be considered stable if the pitch angle values ​​are smoothed over a certain interval.

[0030] In this embodiment, as an example, the interval average value of the pitch angle is calculated every 1.0 seconds, and if the absolute value (change) of the difference between the interval average value of one interval and the interval average value of the next interval is less than or equal to a reference value (for example, 0.01 degrees), then the change in the pitch angle of the vehicle is small and stable. Note that the length of the interval and the magnitude of the reference value are not limited to the above and can be determined based on the results of simulations or experiments.

[0031] Figures 7(A) and 7(B) are schematic waveform diagrams illustrating other examples of pitch angle changes when a vehicle is traveling on a flat road. In Figures 7(A) and 7(B), one cell on the horizontal axis corresponds to 0.2s, and one cell on the vertical axis corresponds to 1.0deg. Figure 7(A) shows an example of pitch angle change when the road surface angle θz changes, and Figure 7(B) shows an example of pitch angle change when there is head-up or head-down due to acceleration or deceleration of the vehicle. These are examples of pitch angle changes corresponding to the above-described condition (c).

[0032] As shown in each figure, if there is a large change in the pitch angle, it may indicate that the vehicle's head is up or down, and in such cases, the gravitational acceleration component is unnecessary and should be excluded. Therefore, if the absolute value (amount of change) of the difference between the stable pitch angle at time A and the stable pitch angle at time B changes by more than a predetermined threshold, it is determined to be "unstable". The threshold can be set to 3.0 degrees as an example.

[0033] On the other hand, we want to ensure that the stable state after a simple change in the road surface angle is not excluded. Therefore, each time the difference in pitch angle exceeds the threshold mentioned above, the threshold is changed to a larger value. As a result, if the change in pitch angle remains small, as in period B to period C in Figure 7(A), it can be determined to be "stable." Conversely, if the change in pitch angle remains large, as in period B to period C in Figure 7(B), it can be determined to be "unstable." The threshold is reset to its initial value (3.0deg in the above example) whenever the pitch angle is determined to be "stable" at any point.

[0034] Figure 8 is a flowchart showing the operation procedure of the vehicle lighting system. These processes are repeatedly executed by the controller 10 at predetermined intervals (for example, every 100ms). In any of the operation procedures, the order of processing can be changed as appropriate, as long as it does not cause inconsistencies or contradictions in the results of the information processing, and other processes not mentioned here may be added, and such embodiments are not excluded. The operation of the vehicle lighting system will be described in detail below with reference to this flowchart.

[0035] The controller 10 reads angular velocity data from the gyro sensor 11 and acceleration data from the acceleration sensor 12 (step S11). Specifically, the angular velocity data is read by the attitude angle calculation unit 21, and the acceleration data is read by the attitude angle calculation unit 21 and the gravity acceleration component processing unit 23.

[0036] The attitude angle calculation unit 21 determines the pitch angle, roll angle, and yaw angle of the vehicle based on the angular velocity data (step S12).

[0037] The vehicle status output unit 22 calculates the interval average value of the pitch angle for the current cycle and the previous cycle (step S13). The interval average value for the current cycle is calculated as Av (n) , the interval average of the previous period is Av (n-1)Let it be so. The length of the interval is 1.0 s as described above as an example. In the case where the necessary and sufficient number of pitch angle data for the calculation has not been obtained (such as immediately after the start of processing), processing such as using a preset alternative value is performed.

[0038] The vehicle state output unit 22 obtains the absolute value |Av (n) -Av (n-1) | of the interval average value difference. When the absolute value of this difference is smaller than a predetermined reference value (0.01 deg as an example) (step S14; YES), the threshold B corresponding to the case of the above condition (c) is set (step S15).

[0039] Next, the vehicle state output unit 22 obtains the absolute value |D - Av (n) of the difference between the interval average value Av (n) of the pitch angle in the current cycle and the value of the previously stored stable angle D. When this is not less than the threshold B (step S16; NO), the count value, which is a parameter indicating the number of times the absolute value has become not less than the threshold B, is incremented and stored in the memory 13 (step S17).

[0040] Here, the above count value is used when setting the threshold B in step S15 described above. Specifically, if the current count value is C n the threshold B is set to, for example, 3.0×(C n +1)[deg]. And each time the process of step S17 is performed, this count value C n increases by 1. Therefore, the threshold is set to increase each time the number of times the absolute value becomes not less than the threshold B in step S16 increases. Thereby, it corresponds to the case of the above condition (c) and the threshold can be gradually increased.

[0041] On the other hand, when the absolute value |D - Av (n) of the difference between the interval average value Av (n) of the pitch angle in the current cycle and the previously stored stable angle D is smaller than the threshold B (step S16; YES), the interval average value Av (n)The value of the new stable angle D is stored in memory 13 (step S18). In step S16, if the previously stored stable angle D does not exist, such as immediately after the start of the calculation, a predetermined alternative value may be used as the stable angle D.

[0042] Next, the vehicle status output unit 22 outputs the count value C n Initialize it to 0 (step S19). This ensures that when the next threshold B is set, threshold B is returned to its initial value (for example, 3.0deg).

[0043] Next, the gravity acceleration component processing unit 23 uses the value of the stable angle D as the angle θ0 corresponding to the gravity acceleration component, and uses the roll angle θr obtained using the gyro sensor 11 to calculate the gravity acceleration components X0, Y0, and Z0 corresponding to each of the X, Y, and Z axes (step S20), and stores these calculated gravity acceleration component values ​​X0, Y0, and Z0 in the memory 13 (step S21).

[0044] On the other hand, in step S14 described above, the absolute value of the interval mean difference |Av (n) -Av (n-1) If | is greater than or equal to a predetermined reference value (step S14; NO), the gravity acceleration component processing unit 23 reads the values ​​of gravity acceleration components X0, Y0, and Z0 stored in the memory 13 and removes them from the acceleration of the acceleration sensor 12 read in step S11 (step S22). Specifically, if the accelerations obtained from the acceleration sensor 12 are X, Y, and Z, the calculations X-X0, Y-Y0, and Z-Z0 are performed. The data of each calculated acceleration is output to the optical axis control unit 24.

[0045] Next, the optical axis control unit 24 determines the vehicle angle based on the acceleration data output from the gravity acceleration component processing unit 23 (step S23), and generates and outputs a control signal to control the optical axis of the light emitted by each lamp unit 30L, 30R according to this vehicle angle (step S24). In step S23, various known methods can be used; for example, a certain number of acceleration data can be collected and statistically processed, and the vehicle angle can be determined using the results.

[0046] According to the embodiments described above, when using auto-leveling technology, it is possible to reduce the time required to achieve accurate optical axis control based on the vehicle angle.

[0047] This disclosure is not limited to the embodiments described above, and can be implemented in various modified forms within the scope of the gist of this disclosure. For example, the above embodiment illustrates a case where the XYZ axes of the acceleration sensor substantially coincide with the longitudinal, lateral, and vertical directions of the vehicle, but the arrangement of the axes is not limited to this, and the XYZ axes may be arranged in a way that they do not coincide with the longitudinal, lateral, and vertical directions of the vehicle. In that case, appropriate correction processing can be performed on the output of each axis of the acceleration sensor 12.

[0048] This disclosure has the following features:

[0049] (Note 1) A device for controlling the optical axis of the headlights mounted on a vehicle, An acceleration sensor installed in the aforementioned vehicle, A gyro sensor installed in the aforementioned vehicle, A controller connected to the acceleration sensor and the gyro sensor, Includes, The aforementioned controller, Using the output of the gyro sensor, the pitch angle of the vehicle is determined. When the amount of change in the pitch angle is smaller than a predetermined reference value, the gravitational acceleration component corresponding to at least the longitudinal and vertical directions of the vehicle is calculated using the pitch angle. From each of the accelerations corresponding to the longitudinal and vertical directions of the vehicle, obtained using the output of the acceleration sensor, the respective gravity acceleration components are removed. The optical axis of the headlight is controlled using the accelerations corresponding to the longitudinal and vertical directions of the vehicle after removing each of the aforementioned gravity acceleration components. Headlight beam control device for vehicles.

[0050] (Note 2) A device for controlling the optical axis of the headlights mounted on a vehicle, An acceleration sensor installed in the aforementioned vehicle, A gyro sensor installed in the aforementioned vehicle, A controller connected to the acceleration sensor and the gyro sensor, Includes, The aforementioned controller, An angle calculation unit that uses the output of the gyro sensor to determine the pitch angle of the vehicle, When the amount of change in the pitch angle is smaller than a predetermined reference value, the removal processing unit calculates the gravitational acceleration component corresponding to at least the longitudinal and vertical directions of the vehicle using the pitch angle, and removes each of the gravitational acceleration components from each of the accelerations corresponding to the longitudinal and vertical directions of the vehicle obtained using the output of the acceleration sensor. An optical axis control unit controls the optical axis of the headlight using the accelerations corresponding to the longitudinal and vertical directions of the vehicle after removing each of the aforementioned gravity acceleration components, A headlight beam control device for vehicles, including a headlight beam control device.

[0051] (Note 3) The removal processing unit calculates the gravitational acceleration component corresponding to at least the longitudinal and vertical directions of the vehicle using the second average value of the pitch angle when the amount of change between the first average value of the pitch angle in the first period and the second average value of the pitch angle in the second period is smaller than a predetermined reference value. Headlight beam control device for vehicles as described in Appendix 2.

[0052] (Note 4) The removal processing unit sets the second average value of the pitch angle as the new stable angle value when the amount of change between the second average value of the pitch angle and a predetermined stable angle value is smaller than a predetermined threshold. Headlight beam control device for vehicles as described in Appendix 3.

[0053] (Note 5) The removal processing unit changes the threshold to a larger value if the amount of change between the second average value of the pitch angle and the stable angle value is greater than or equal to the threshold. Headlight beam control device for vehicles as described in Appendix 4.

[0054] (Note 6) The removal processing unit, in a processing opportunity after the threshold has been changed, changes the threshold back to its initial value if the amount of change between the second average value of the pitch angle and a predetermined stable angle value is smaller than the threshold. Headlight beam control device for vehicles as described in Appendix 5.

[0055] (Note 7) If the pitch angle is θ and the acceleration due to gravity is G, The gravitational acceleration component X0 corresponding to the longitudinal direction of the vehicle can be obtained by the relationship X0 = -Gsinθ. The gravitational acceleration component Z0 corresponding to the vertical direction of the vehicle can be obtained by the relationship Z0 = Gcosθ. A headlight beam control device for vehicles as described in any of the appendices 1 to 6.

[0056] (Note 8) To control the beam axis of the headlights mounted on the vehicle, the vehicle is equipped with Canada Speed ​​sensor and Ji A method performed by a controller connected to each of the gyro sensors, The pitch angle of the vehicle is determined using the output of the gyro sensor. When the amount of change in the pitch angle is smaller than a predetermined reference value, The Using the pitch angle at one time point, calculate the gravitational acceleration component corresponding to at least the longitudinal and vertical directions of the vehicle. To remove the gravity acceleration component from each of the accelerations corresponding to the longitudinal and vertical directions of the vehicle, respectively, which are obtained using the output of the acceleration sensor, The optical axis of the headlight is controlled using the accelerations corresponding to the longitudinal and vertical directions of the vehicle after removing each of the aforementioned gravity acceleration components. A method for controlling the optical axis of a vehicle's headlight, including the method described above.

[0057] (Note 9) A vehicle lighting system comprising a light axis control device described in any of the appendices 1 to 7, and a headlight controlled by said light axis control device. [Explanation of Symbols]

[0058] 10: Controller, 11: Gyro sensor, 12: Accelerometer, 13: Memory, 21: Attitude angle calculation unit, 22: Vehicle status output unit, 23: Gravity acceleration component processing unit, 24: Optical axis control unit, 30L, 30R: Lamp unit

Claims

1. A device for controlling the optical axis of the headlights mounted on a vehicle, An acceleration sensor installed in the aforementioned vehicle, A gyro sensor installed in the aforementioned vehicle, A controller connected to the acceleration sensor and the gyro sensor, Includes, The aforementioned controller, Using the output of the gyro sensor, the pitch angle of the vehicle is determined. When the amount of change in the pitch angle is smaller than a predetermined reference value, the gravitational acceleration component corresponding to at least the longitudinal and vertical directions of the vehicle is calculated using the pitch angle. From each of the accelerations corresponding to the longitudinal and vertical directions of the vehicle, obtained using the output of the acceleration sensor, the respective gravity acceleration components are removed. The optical axis of the headlight is controlled using the accelerations corresponding to the longitudinal and vertical directions of the vehicle after removing each of the aforementioned gravity acceleration components. Headlight beam control device for vehicles.

2. A device for controlling the optical axis of the headlights mounted on a vehicle, An acceleration sensor installed in the aforementioned vehicle, A gyro sensor installed in the aforementioned vehicle, A controller connected to the acceleration sensor and the gyro sensor, Includes, The aforementioned controller, An angle calculation unit that uses the output of the gyro sensor to determine the pitch angle of the vehicle, When the amount of change in the pitch angle is smaller than a predetermined reference value, the removal processing unit calculates the gravitational acceleration component corresponding to at least the longitudinal and vertical directions of the vehicle using the pitch angle, and removes each of the gravitational acceleration components from each of the accelerations corresponding to the longitudinal and vertical directions of the vehicle obtained using the output of the acceleration sensor. An optical axis control unit controls the optical axis of the headlight using the accelerations corresponding to the longitudinal and vertical directions of the vehicle after removing each of the aforementioned gravity acceleration components, A headlight beam control device for vehicles, including a headlight beam control device.

3. The removal processing unit calculates the gravitational acceleration component corresponding to at least the longitudinal and vertical directions of the vehicle using the second average value of the pitch angle when the amount of change between the first average value of the pitch angle in the first period and the second average value of the pitch angle in the second period is smaller than a predetermined reference value. The optical axis control device for a vehicle headlight according to claim 2.

4. The removal processing unit sets the second average value of the pitch angle as the new stable angle value when the amount of change between the second average value of the pitch angle and a predetermined stable angle value is smaller than a predetermined threshold. The optical axis control device for a vehicle headlight according to claim 3.

5. The removal processing unit changes the threshold to a larger value when the amount of change between the second average value of the pitch angle and the stable angle value is greater than or equal to the threshold. The optical axis control device for a vehicle headlight according to claim 4.

6. The removal processing unit, in a processing opportunity after the threshold has been changed, changes the threshold back to its initial value if the amount of change between the second average value of the pitch angle and a predetermined stable angle value is smaller than the threshold. The optical axis control device for a vehicle headlight according to claim 5.

7. If the pitch angle is θ and the acceleration due to gravity is G, The gravitational acceleration component X0 corresponding to the longitudinal direction of the vehicle can be obtained by the relationship X0 = -Gsinθ, The gravitational acceleration component Z0 corresponding to the vertical direction of the vehicle can be obtained by the relationship Z0 = Gcosθ. The optical axis control device for a vehicle headlight according to claim 1 or 2.

8. A method for controlling the optical axis of a headlight mounted on a vehicle, performed by a controller connected to an acceleration sensor and a gyro sensor installed on the vehicle, The pitch angle of the vehicle is determined using the output of the gyro sensor. When the amount of change in the pitch angle is smaller than a predetermined reference value, the gravitational acceleration component corresponding to at least the longitudinal and vertical directions of the vehicle is calculated using the pitch angle in the first period. To remove the gravity acceleration component from each of the accelerations corresponding to the longitudinal and vertical directions of the vehicle, which are obtained using the output of the acceleration sensor, The optical axis of the headlight is controlled using the accelerations corresponding to the longitudinal and vertical directions of the vehicle after removing each of the aforementioned gravity acceleration components. A method for controlling the optical axis of a vehicle's headlight, including the method described above.

9. A vehicle lighting system comprising an optical axis control device according to claim 1 or 2, and a headlight controlled by the optical axis control device.

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