Lighting system and lamp control method

Abstract

In the present invention, a high-definition lamp unit (110) comprises a plurality of individually controllable pixels (PIX), and emits lamp light having a light distribution pattern (PTN) comprising a light-shielding portion (SHD) in accordance with states of the plurality of pixels (PIX). A sensor (120) is provided so as to be able to detect a dynamic component of the pitch angle of a vehicle body during travel. A first controller (160) generates light-shielding information including a target location of the light-shielding portion (SHD) on the basis of an output of an optical sensor (150). A second controller (200) turns off a pixel group, among the plurality of pixels (PIX), that corresponds to the light-shielding portion (SHD), and causes the location of the OFF pixel group corresponding to the light-shielding portion (SHD) to move in the up-down direction from the target location of the light-shielding portion (SHD) in accordance with the dynamic component of the pitch angle of the vehicle body.

Description

[Technical Field]

[0001] This disclosure relates to vehicle lighting equipment. [Background technology]

[0002] Vehicle lighting systems generally allow switching between low beams and high beams. Low beams illuminate the immediate vicinity of the vehicle with a predetermined illuminance, and their light distribution is regulated to avoid glare to oncoming or preceding vehicles. They are mainly used when driving in urban areas. High beams, on the other hand, illuminate a wide area and far ahead with a relatively high illuminance. They are mainly used when driving at high speeds on roads with few oncoming or preceding vehicles. Therefore, while high beams offer better visibility to the driver compared to low beams, they have the problem of causing glare to drivers of vehicles in front of the vehicle and to pedestrians.

[0003] In recent years, Adaptive Driving Beam (ADB) technology has been proposed, which dynamically and adaptively controls the high beam light distribution pattern based on the surrounding conditions of the vehicle. This system detects preceding vehicles, oncoming vehicles (collectively referred to as "vehicles ahead"), pedestrians, and signs (hereinafter collectively referred to as "objects"), and reduces glare on the vehicle by shading or dimming the area corresponding to the vehicle. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2019-116232 [Overview of the project] [Problems that the invention aims to solve]

[0005] The ADB control method investigated by the present inventors will be described as a comparative technique. In the ADB control method of the comparative technique, the field of view in front of the vehicle is sensed by an optical sensor such as a camera, and the output of the optical sensor (for example, the camera image) is processed to detect the position of objects that should not cause glare.

[0006] Figure 1 illustrates the ADB control related to the comparative technology. In the comparative technology, a camera is used as the optical sensor. Figure 1 shows an example of a camera image IMG and its corresponding light distribution pattern PTN. The ADB controller detects an object OBJ in the camera image IMG and determines the position (H,V) of the light-shielding portion (or light-reducing portion) according to its position (x,y). The resulting light distribution pattern PTN includes the light-shielding portion SHD at the position (H,V) corresponding to the object OBJ, thereby preventing glare. When the camera image IMG is updated and the position (x,y) of the object OBJ in the camera image IMG changes, the position (H,V) of the light-shielding portion SHD also moves in accordance with the object OBJ.

[0007] Figure 2 illustrates the ADB control related to the comparative technique. The upper part of Figure 2 shows the vertical coordinate y of the object OBJ included in the camera image IMG. The coordinate y is updated according to the camera's frame rate. The frame rate is 30fps to 60fps, and as fast as 120fps, but signal processing for object detection can have delays of several frames, or on the order of tens of milliseconds. Therefore, it is difficult for object detection based on camera images to track fast (e.g., 1Hz to several Hz) position changes of objects without delay. In the comparative technique, it was assumed that the vertical position y of the object OBJ in the camera image IMG does not change on time scales shorter than 500ms to 1s, and the coordinate y was smoothed using a filter with a long time constant to generate the vertical position V of the light-shielding portion SHD.

[0008] Between times t0 and t1, the vehicle's posture remains constant. Objects captured by a camera on a vehicle with no posture fluctuations tend to move relatively quickly horizontally (left-right) but slowly vertically (up-down). Therefore, the y-coordinate changes more slowly than the frame rate.

[0009] Now, let's assume that pitching vibration occurred between times t1 and t2. As the tilt angle of the vehicle changes during travel, the camera also pitches accordingly. Therefore, the vertical coordinate y of the object in the camera image will also vibrate.

[0010] However, due to the averaging process described above, the vertical position V of the light-shielding portion SHD remains constant, unaffected by the pitching vibrations of the vehicle body. Consequently, the light-shielding portion SHD of the high beam light distribution pattern PTN vibrates up and down in accordance with the pitching vibrations of the vehicle body.

[0011] Figures 3(a) to 3(c) illustrate the light distribution patterns generated by ADB control in the comparative technology. Figures 3(a) to 3(c) show the light distribution patterns PTN in the normal, nose-up, and nose-down (nose-dive) states, respectively. Even if pitching vibration occurs, it is not permissible to cause glare on the object OBJ. Therefore, in the comparative technology, assuming pitching vibration, it was necessary to set the vertical length (height) ΔH of the light-shielding portion SHD to be long by adding a margin to the height of the object OBJ, and light was shielded even in areas where the object OBJ was not present.

[0012] In addition, in the comparative technology, the sunshade portion (SHD) vibrated up and down when the vehicle body pitched, causing discomfort to the driver.

[0013] This disclosure is made in the context of the present circumstances, and one of its exemplary purposes is to provide a lighting system that can provide the driver with an improved field of view while preventing glare. [Means for solving the problem]

[0014] A lighting system in one aspect of the present disclosure includes: a variable-beam lamp that includes a plurality of individually controllable pixels and emits light having a light distribution pattern including a light-shielding portion according to the state of the plurality of pixels; a sensor that is capable of detecting the dynamic component of the pitch angle of the vehicle while it is in motion; an optical sensor; a first controller that generates light-shielding information including the target position of the light-shielding portion based on the output of the optical sensor; and a second controller that turns off a group of pixels corresponding to the light-shielding portion from among the plurality of pixels, and moves the position of the group of off pixels corresponding to the light-shielding portion vertically in accordance with the dynamic component of the pitch angle of the vehicle, with respect to the target position of the light-shielding portion.

[0015] Another aspect of the present disclosure relates to a control method for a variable-beam lamp that includes a plurality of individually controllable pixels and emits light having a light distribution pattern including a light-shielding portion depending on the state of the plurality of pixels. The control method includes the steps of: detecting a dynamic component of the pitch angle of the vehicle while it is moving; detecting an object located in front of the vehicle; generating a target position for the light-shielding portion based on the position of the object; and turning off a group of pixels corresponding to the light-shielding portion from among the plurality of pixels, and moving the position of the group of off pixels corresponding to the light-shielding portion in the vertical direction with respect to the target position of the light-shielding portion according to the dynamic component of the pitch angle of the vehicle.

[0016] Furthermore, any combination of the above components, or any substitution of components or expressions between methods, apparatus, systems, etc., are also valid as embodiments of the present invention or this disclosure. Moreover, the description in this section (means for solving the problem) does not describe all the indispensable features of the present invention, and therefore, subcombinations of these described features may also constitute the present invention. [Effects of the Invention]

[0017] According to certain aspects of this disclosure, it is possible to provide the driver with an improved field of view while preventing glare. [Brief explanation of the drawing]

[0018] [Figure 1] This is a diagram for explaining ADB control according to the comparative art. [Figure 2] This is a diagram for explaining ADB control according to the comparative art. [Figure 3] Figures 3(a) to (c) are diagrams for explaining light distribution patterns generated by ADB control according to the comparative art. [Figure 4] This is a block diagram of a lamp system according to an embodiment. [Figure 5] Figures 5(a) and (b) are diagrams for explaining the pitch angle θp of the vehicle body. [Figure 6] This is a functional block diagram of the second controller. [Figure 7] This is a diagram showing an example of a vehicle driving scene. [Figure 8] This is a diagram showing the waveform of the dynamic pitch angle θd and the waveform of the correction amount ΔV corresponding to the driving scene in Figure 7. [Figure 9] Figures 9(a) to (c) are diagrams for explaining light distribution patterns generated by ADB control according to the embodiment. [Figure 10] This is a diagram showing light rays corresponding to the boundary between the light-shielded portion SHD and the irradiation portion of the headlamp light (that is, the lower end or upper end of the light-shielded portion) in the driving scene of Figure 7. [Figure 11] Figures 11(a) to (c) are diagrams showing examples of the relationship (control characteristic) between the dynamic pitch angle θd and the correction amount ΔV. [Figure 12] This is a diagram showing a light distribution pattern PTN including a dimmed portion. [Mode for Carrying Out the Invention]

[0019] (Overview of Embodiment) This section outlines some exemplary embodiments of the present disclosure. This outline is intended to provide a basic understanding of the embodiments and to simplify some concepts of one or more embodiments, serving as a prelude to the more detailed descriptions that follow. It does not limit the scope of the invention or disclosure. Furthermore, this outline is not a comprehensive overview of all possible embodiments and does not limit the essential components of the embodiments. For convenience, "one embodiment" may refer to one or more embodiments (examples or variations) disclosed herein.

[0020] A lighting system according to one embodiment includes a variable-beam lamp that includes a plurality of individually controllable pixels and emits light having a light distribution pattern including a light-shielding portion according to the state of the plurality of pixels; a sensor that is provided to detect the dynamic component of the pitch angle of the vehicle while it is in motion; an optical sensor; a first controller that generates light-shielding information including the target position of the light-shielding portion based on the output of the optical sensor; and a second controller that turns off a group of pixels corresponding to the light-shielding portion from among the plurality of pixels, and moves the position of the group of off pixels corresponding to the light-shielding portion vertically in accordance with the dynamic component of the pitch angle of the vehicle, with respect to the target position of the light-shielding portion.

[0021] With this configuration, glare can be prevented by moving the light-blocking portion downwards when the rear of the vehicle sinks (nose up) and upwards when the front of the vehicle sinks (nose dive). In addition, when the vehicle pitches, the light-blocking portion is maintained at the same height as the road surface, which reduces the discomfort felt by the driver. Note that "light blocking" and "pixels off" do not mean that the illuminance or brightness is completely zero, but include illuminance and brightness that do not cause glare.

[0022] In one embodiment, the second controller may move the group of on pixels corresponding to the illuminated portion surrounding the light-shielding portion in the vertical direction in conjunction with the group of off pixels. In other words, the entire light distribution formed by the variable light distribution lamp may be moved in the vertical direction.

[0023] In one embodiment, the second controller generates dimming information including the target position of the dimmed portion based on the output of the optical sensor, and the second controller may reduce the brightness of the pixel group corresponding to the dimmed portion among the plurality of pixels compared to the on-pixel group, and move the position of the pixel group corresponding to the dimmed portion vertically in accordance with the dynamic component of the pitch angle of the vehicle body, with respect to the target position of the dimmed portion.

[0024] The target position of the light-shielding portion changes at frequencies lower than 5 Hz, and the dynamic component of the pitch angle may include frequencies higher than 0.5 Hz.

[0025] In one embodiment, the sensor may include a gyro sensor. The gyro sensor can acquire the angular velocity in the pitch direction, and by integrating it, the dynamic pitch angle can be obtained.

[0026] (Embodiment) Preferred embodiments will be described below with reference to the drawings. The same or equivalent components, members, and processes shown in each drawing will be denoted by the same reference numerals, and redundant descriptions will be omitted where appropriate. Furthermore, the embodiments are illustrative and not limiting, and not all features or combinations thereof described in the embodiments are necessarily essential to the disclosure.

[0027] In this specification, "member A connected to member B" includes not only cases where member A and member B are directly connected physically, but also cases where member A and member B are indirectly connected via other members that do not substantially affect their electrical connection or impair the functions or effects produced by their combination.

[0028] Similarly, "the state in which member C is provided between member A and member B" includes not only cases where member A and member C, or member B and member C, are directly connected, but also cases where they are indirectly connected via other members that do not substantially affect their electrical connection state or impair the functions or effects produced by their combination.

[0029] Figure 4 is a block diagram of the lighting system 100 according to the embodiment. The lighting system 100 is a headlamp mounted on an automobile that illuminates the field of view in front of the vehicle with a beam, and is equipped with an ADB (Adaptive Driving Beam) function.

[0030] The lighting system 100 includes a high-definition lamp unit 110, a sensor 120, an optical sensor 150, a first controller 160, and a second controller 200.

[0031] In this embodiment, the high-definition lamp unit 110 is a variable-beam lamp configured to illuminate part or all of the high-beam region, and is also referred to as an ADB lamp. The high-definition lamp unit 110 may cover part or all of the low-beam region in addition to part or all of the high-beam region. The high-definition lamp unit 110 includes a plurality of individually controllable pixels PIX and emits light having a light distribution pattern according to the state of the plurality of pixels PIX. For example, the high-definition lamp unit 110 includes a light-emitting element array 112 and an illumination optical system 114. An LED array can be used as the light-emitting element array 112.

[0032] The brightness of each pixel PIX may be controllable in two tones (on and off) or in multiple tones. Furthermore, when controllable in two tones (on and off), multiple tones may be expressed by PWM dimming by rapidly switching each pixel PIX and changing the time ratio (duty cycle) between the on and off times.

[0033] The illumination optical system 114 projects the output light from the light-emitting element array 112 forward of the vehicle. The illumination optical system 114 may be a lens optical system, a reflective optical system, or a combination thereof.

[0034] Figure 4 shows a virtual vertical screen 2. The virtual vertical screen 2 is assumed to be a coordinate system based on the road surface. The distance between the virtual vertical screen 2 and the vehicle (lighting fixture) can be 10m or 25m. On the virtual vertical screen 2, the light from the high-definition lamp unit 110 forms a high-beam light distribution pattern PTN. The light distribution pattern PTN is the intensity distribution of the light on the virtual vertical screen 2 and is based on the on / off patterns of multiple pixels PIX of the light-emitting element array 112. The correspondence between the position of a certain pixel PIX and the corresponding illuminated area on the virtual vertical screen 2 is determined by the illumination optical system 114, and may be a mirror image (left-right inversion), up-down inversion, or up-down-left-right inversion.

[0035] The optical sensor 150 senses the field of view in front of the vehicle. The optical sensor 150 can be an optical camera, but other optical sensors such as LiDAR, ToF cameras, gating cameras, or stereo cameras may also be used.

[0036] The first controller 160 determines the position and type of an object OBJ in front of the vehicle based on the image data IMG generated by the optical sensor 150. For example, the frame rate of the optical sensor 150 is about 30 to 120 fps, and the object OBJ detection process is performed for each frame. Signal processing for object detection may take longer than tens of milliseconds. If the object OBJ is one that should not cause glare, such as an oncoming or preceding vehicle, then shading information INFO_SHD is generated, which includes the target position of the shading portion SHD of the light distribution pattern. The vertical target position of the shading portion SHD is generated by filtering the y coordinate of the object OBJ in the image data IMG. Due to the delay in the object detection process and the filtering, the position of the shading portion SHD changes at a rate of 5 Hz or slower. The position information of the shading portion SHD may indicate the center coordinate of the shading portion SHD. If the shading portion SHD is rectangular, it may indicate the coordinates of the two diagonal vertices of the shading portion SHD.

[0037] The tilt angle (vehicle posture) of an automobile changes depending on the front-to-rear weight balance. The tilt angle also changes due to unevenness and bumps in the road surface while driving. The tilt angle in the front-to-rear direction corresponds to the rotation around the horizontal axis extending from left to right of the vehicle body and is called the pitch angle (also called the posture angle) θp. Sensor 120 is installed to detect the dynamic component of the pitch angle θp of the vehicle body on which the lighting system 100 is mounted while driving.

[0038] The second controller 200 receives light-shielding information INFO_SHD from the first controller 160. The second controller 200 turns off the group of pixels PIX of the light-emitting element array 112 that correspond to the light-shielding portion SHD, and turns on the group of pixels that correspond to the illuminated portion other than the light-shielding portion in the high beam light distribution pattern.

[0039] The second controller 200 detects the dynamic component of the vehicle body's pitch angle θp in accordance with the output (detection signal) S1 of the sensor 120. The second controller 200 moves the position of the off-pixel group corresponding to the light-shielding portion SHD vertically in accordance with the dynamic component of the vehicle body's pitch angle θp, using the target position obtained from the light-shielding information INFO_SHD as a reference.

[0040] The high-definition lamp unit 110 and the second controller 200 may be integrated into the headlamp 510.

[0041] For example, the sensor 120 may be installed on the headlamp side or on the vehicle side. If installed on the headlamp side, it may be built into the headlamp housing (lamp body) or attached externally to the lamp body. If installed on the vehicle side, it may be placed inside the passenger compartment or outside the passenger compartment, for example, in the engine compartment. The optical sensor 150 may be installed on the vehicle side or built into the headlamp 510. If the optical sensor 150 is built into the headlamp, the first controller 160 can also be built into the headlamp 510. In this case, the first controller 160 and the second controller 200 may be made of the same hardware. If the optical sensor 150 is installed on the vehicle side, the first controller 160 may also be installed on the vehicle side.

[0042] In this embodiment, the second controller 200 corrects the position of the light-shielding portion SHD in response to variations in the pitch angle θp caused by various factors while the vehicle is stationary and in motion.

[0043] Figures 5(a) and 5(b) illustrate the pitch angle θp of the vehicle body. Figure 5(a) shows the pitch angle θp when the vehicle is stationary. The pitch angle θp when the vehicle is stationary is called the static pitch angle θs. The static pitch angle θs indicates the attitude of the vehicle when it is stopped, and is therefore also called the stationary vehicle attitude angle. The static pitch angle θs is determined by the number of passengers, their positions, the weight of the luggage in the cargo compartment, the stiffness of the front and rear suspensions, etc. In this embodiment, the pitch angle θp is taken as the angle between a straight line 12 parallel to the road surface 10 and the reference line 22 of the vehicle body 20, and the direction in which the reference line 22 points upward (the nose-up direction) is taken as positive.

[0044] Figure 5(b) shows the pitch angle θp of the vehicle while it is in motion. The pitch angle θp of the vehicle while it is in motion can be understood as the sum of the static pitch angle θs and the dynamic component (also called the dynamic pitch angle or the amount of variation in the pitch angle) θd. The dynamic pitch angle θd may include the following components. (i) Nose-up during acceleration and nose-down during deceleration (ii) Changes in vehicle load (weight balance) caused by factors such as road surface incline. (iii) High-speed vehicle vibrations caused by uneven road surfaces

[0045] (i) Pitch angle changes due to acceleration and deceleration of the vehicle body, or (ii) Changes in the load of the vehicle body Because the pitch angle change persists for several seconds, it is typically a DC fluctuation, and its frequency component is very low (below 0.5 Hz).

[0046] In contrast, (iii) vibrations of the vehicle body caused by uneven road surfaces can be attributed to the stiffness of the suspension and While it depends on the vehicle's weight, the frequency generally falls within the range of approximately 0.5 to 5 Hz. For example, a sharp vehicle vibration is typically in the range of 0.9 to 2 Hz.

[0047] In this embodiment, frequency components of pitch angle fluctuations exceeding 0.5 Hz (generally 0.5 to 5 Hz, for example 1 to 2 Hz), which were conventionally removed as noise, are not removed as noise but are included in the correction. In this specification, the position correction of the light-shielding portion for correcting pitch angle fluctuations during driving is referred to as dynamic leveling.

[0048] Returning to Figure 4, the following section will describe in detail dynamic leveling, particularly leveling in response to high-speed pitch angle fluctuations caused by road surface irregularities. Sensor 120 is provided to detect the dynamic component θd of the pitch angle θp while the vehicle is in motion.

[0049] In this embodiment, the sensor 120 includes a gyro sensor. The gyro sensor can be mounted in any direction, but preferably one of its detection axes is oriented horizontally to the left and right of the vehicle body, and it generates a detection signal S1 indicating the angular velocity ωp of the rotational motion around this detection axis. The gyro sensor may have three axes or one axis.

[0050] The second controller 200 is an ECU (Electronic Control Unit) that integrates functions related to optical axis correction and performs processing related to dynamic leveling. The leveler 200 may be a leveling-dedicated ECU (also called a leveling ECU), an ECU integrated with a controller having other functions, or it may be configured by dividing it into multiple ECUs.

[0051] The functions of the second controller 200 may be implemented by software processing, by hardware processing, or by a combination of software and hardware processing. Specifically, the software processing may involve the CPU (Central Processing Unit) and M PU (Micro Processing Unit), microcontrollers, and other processors (hardware (a) is implemented as a combination of a) and a software program executed by a processor (hardware). The second controller 200 may be a combination of multiple processors (microcontrollers).

[0052] Hardware processing is specifically implemented using hardware such as ASICs (Application Specific Integrated Circuits), controller ICs, and FPGAs (Field Programmable Gate Arrays).

[0053] The second controller 200 detects the dynamic component θd of the pitch angle θp during vehicle movement by integrating the angular velocity ωp indicated by the detection signal S1. Here, the dynamic component θd can be considered as the component of the pitch angle θp fluctuation that falls within a predetermined frequency band higher than 0.5 Hz. For example, the component of the pitch angle θp fluctuation that falls within a predetermined frequency band is to be corrected as the dynamic component. The predetermined frequency band can be set, for example, in the range of approximately 0.5 Hz to 5 Hz. Which frequency band to correct should be determined based on factors such as the stiffness of the suspension and the mass of the vehicle body.

[0054] The second controller 200 then moves the position of the light-shielding portion SHD of the light distribution pattern PTN (position in the vertical direction V) upward and / or downward, based on the target position V0 indicated by the light-shielding information INFO_SHD, according to the dynamic component θd of the pitch angle θp of the moving vehicle body.

[0055] The second controller 200 moves the light-shielding portion SHD downward in response to a positive dynamic pitch angle θd. Conversely, the second controller 200 moves the light-shielding portion SHD upward in response to a negative dynamic pitch angle θd.

[0056] More specifically, the second controller 200 moves the position of the light-shielding portion SHD upward and downward with respect to a predetermined position V0 in order to cancel out the dynamic component θd of the pitch angle θp. The predetermined position V0 is the vertical coordinate where the light-shielding portion SHD should be located when the variation in the pitch angle θp is zero.

[0057] The second controller 200 changes the position of the off-pixel group of multiple pixels PIX of the light-emitting element array 112 in order to raise and lower the light-shielding portion SHD of the light distribution pattern PTN on the virtual vertical screen 2. The number of pixels to shift the off-pixel group for a certain range of variation in the pitch angle θp can be determined geometrically and optically. Let the amount of pixel shift be Δy.

[0058] Figure 6 is a functional block diagram of the second controller 200. The second controller 200 includes a pitch angle calculation unit 210 and a light shielding position correction unit 220.

[0059] The pitch angle calculation unit 210 detects the dynamic component θd of the pitch angle θp based on the output of the sensor 120. For example, the pitch angle calculation unit 210 integrates the angular velocity ωp indicated by the detected signal S1. Furthermore, the pitch angle calculation unit 210 performs calculation processing on the integrated value as needed to calculate the dynamic pitch angle θd. This calculation processing may include filtering (bandwidth limiting) and moving average processing.

[0060] The light-shielding position correction unit 220 moves the position of the light-shielding portion SHD up and down based on the dynamic pitch angle θd. The light-shielding position correction unit 220 includes a correction amount calculation unit 222 and a correction unit 224. The correction amount calculation unit 222 calculates the amount of vertical movement (correction amount ΔV) of the light-shielding portion SHD on the virtual vertical screen 2 based on the dynamic pitch angle θd. In this embodiment, a positive correction amount ΔV corresponds to an upward shift of the light-shielding portion SHD, and a negative correction amount ΔV corresponds to a downward shift of the light-shielding portion SHD. The correction unit 224 controls the light-emitting element array 112 so that the light-shielding portion SHD moves by the correction amount ΔV.

[0061] For example, the light-emitting element array 112 has an interface that takes image data as input, specifying the on / off (or brightness) states of multiple pixels PIX. In this case, the correction unit 224 may shift the positions of the off-pixel group corresponding to the light-shielding portion SHD included in the image data up or down by a number of pixels Δy corresponding to the correction amount ΔV. In other words, the correction unit 224 moves the positions of the off-pixel group of the light distribution pattern included in the image data upward and downward with respect to a predetermined position y0, so as to cancel out the dynamic component θd of the pitch angle θp. The predetermined position y0 is a reference position corresponding to V0.

[0062] The above describes the configuration of the lighting system 100. Next, we will explain its operation.

[0063] Figure 7 shows an example of a vehicle driving scene. In this example, vehicle 30 is traveling from left to right on the page, and is shown crossing a step 14 on the road surface 10. Figure 7 shows the posture of vehicle 30 at multiple times t0 to t4. Each time t0 to t4 shows the following state.

[0064] Time t0: The vehicle is driving just before step 14. Time t1: Front wheel is on top of step 14. Time t2: The front wheel has gone over a step of 14. Time t3: The rear wheel is on top of step 14. Time t4: The rear wheel has gone over a step of 14.

[0065] The dynamic pitch angle θd at times t0, t2, and t4 is 0. The dynamic pitch angle θd at time t1 is a positive value θd1, and the dynamic pitch angle θd at time t3 is a negative value θd3.

[0066] Figure 8 shows the waveform of the dynamic pitch angle θd and the waveform of the correction amount ΔV corresponding to the driving scene in Figure 7. As shown in Figure 7, the dynamic pitch angle θd swings in the positive direction, then in the negative direction, and eventually returns to 0.

[0067] A correction amount ΔV is generated in response to this variation in the dynamic pitch angle θd.

[0068] Figures 9(a) to 9(c) illustrate the light distribution patterns generated by the ADB control according to this embodiment. Figures 9(a) to 9(c) show the light distribution patterns PTN in the normal, nose-up, and nose-down (nose-dive) states, respectively. According to this embodiment, even if pitching vibration occurs, the positional relationship between the light-shielding portion SHD and the object OBJ does not change. Therefore, a margin to account for pitching vibration is not required in the vertical length (height) ΔH of the light-shielding portion SHD, and the height ΔH of the light-shielding portion can be made smaller compared to the comparative technology.

[0069] Furthermore, in the comparative technology, the light-shielding portion SHD vibrated up and down when the vehicle body pitched, causing discomfort to the driver. However, in this embodiment, the vibration of the light-shielding portion SHD is suppressed, thus reducing discomfort and unease for the driver.

[0070] Furthermore, there may be multiple light-shielding sections (SHDs), and if there are multiple SHDs, the vertical position of each section is corrected to follow the changes in the pitch angle.

[0071] Figure 10 shows the light rays corresponding to the boundary between the light-shielding portion SHD and the illuminated portion of the headlamp light in the driving scene of Figure 7 (i.e., the lower or upper end of the light-shielding portion). By adaptive light distribution control that follows the dynamic pitch angle θd, the light rays 32 at the boundary of the light-shielding portion SHD can always be kept at a constant angle with respect to the road surface 10.

[0072] The above describes the operation of the lighting system 100. With this lighting system 100, as shown at time t1 in Figure 10, when the rear of the vehicle 30 sinks, glare can be prevented by lowering the light-shielding portion SHD. Also, as shown at time t3 in Figure 10, when the front of the vehicle 30 sinks, glare can be prevented by raising the light-shielding portion SHD.

[0073] Furthermore, by performing this control in accordance with the dynamic fluctuations of the vehicle's pitch angle θ, even when the vehicle 30 vibrates (pitches) in the longitudinal direction, the position of the light-shielding portion SHD on the virtual vertical screen in front of the vehicle can always be kept constant, preventing objects in front of the vehicle from becoming brighter or darker, and ultimately providing an improved field of view.

[0074] The static pitch angle θs can be considered as a reference value for the pitch angle θp, and the dynamic pitch angle θd can be understood as a dynamic deviation of the pitch angle θp from the reference value. Therefore, the second controller 200 controls the high-definition lamp unit 110 in accordance with this deviation θd so that the angle between the light ray 32 corresponding to the light-shielding portion SHD and the road surface 10 remains constant.

[0075] The following describes an example of light distribution control that follows the variation in pitch angle θp by the second controller 200.

[0076] Figures 11(a) to (c) show examples of the relationship between the dynamic pitch angle θd and the correction amount ΔV (control characteristics).

[0077] When the correction amount ΔV is the amount of movement of the shading portion SHD on the virtual vertical screen, and L is the distance to the virtual vertical screen, then equation (1) must hold. ΔV = L × tanθd …(1) When θd ≈ 0, tanθd ≈ θd, so we obtain equation (2). ΔV ≈ L × θd …(2)

[0078] Therefore, in the simplest form, as shown in Figure 11(a), the correction amount ΔV can be defined as a linear equation with respect to the dynamic pitch angle θd, having a proportionality constant (referred to as the reference gain g0) based on the distance L. As described above, when correcting the image data supplied to the light-emitting element array 112, the off-pixel group corresponding to the light-shielding portion SHD on the image data is shifted vertically so that this correction amount ΔV is obtained (Figure 7). The pixel shift amount Δy at this time can be determined based on the design of the illumination optical system 114, and the relationship Δy = f(θd) holds using a geometrically determined function f(). If the illumination optical system 114 is a simple optical system, f() can be approximated by a linear function and can be expressed by equation (3). Δy = α·θd …(3)

[0079] If the illumination optical system 114 is a complex optical system that includes a reflecting mirror having a hyperbolic paraboloid, an elliptic paraboloid, a paraboloid of revolution, and a free paraboloid, the correction amount ΔV may be defined by a piecewise linear function with respect to the dynamic pitch angle θd, as shown in Figure 11(b).

[0080] Alternatively, even when using a simple optical system, control characteristics like those shown in Figure 11(b) may be defined with the aim of reducing the correction amount ΔV for the unit variation of the dynamic pitch angle θd in the region where the amount of variation (absolute value of θd) is large. In this case, it is possible to suppress glare when a control delay occurs in a situation where the aircraft assumes a nose-up attitude immediately after a nose-dive.

[0081] If the illumination optical system 114 is a complex optical system that includes a reflecting mirror having an elliptical paraboloid or a free paraboloid, more complex control characteristics may be defined, as shown in Figure 11(c).

[0082] Depending on the driving conditions, the movement of the light-shielding portion SHD may be disabled. For example, if the dynamic pitch angle θd contains frequency components that exceed the response speed of the second controller 200, glare can be suppressed by disabling the movement of the light-shielding portion SHD.

[0083] Furthermore, if road surface irregularities occur continuously (for example, for 3 seconds or more), it is assumed that the road surface is special and different from normal road driving (for example, a dirt course or an unpaved mountain road). In such cases, if a steep pitch angle change occurs continuously for a predetermined time (for example, 3 seconds or more), the pitch angle control may be fixed to the control acquired in a stationary or stable driving state. When returning to the original state, it is better to return to the original state gradually over several seconds rather than immediately. In the case of the high-definition lamp unit 110, which can control the intensity distribution with multiple gradations, it is better to return to the original state gradually by applying blurring or gradation.

[0084] (modified version) The embodiments described are illustrative, and various modifications exist. The following describes modifications of the lighting system 100.

[0085] (Variation 1) In the embodiment, a gyro sensor was used to detect the dynamic component of the pitch angle, but this disclosure is not limited thereto. For example, the dynamic component of the pitch angle may be detected based on a combination of a front ride height sensor provided on the front suspension of the vehicle body and a rear ride height sensor provided on the rear suspension of the vehicle body.

[0086] (Modification 2) In this embodiment, the high-definition lamp unit 110 is configured with a light-emitting element array 112, but the disclosure is not limited thereto. For example, the high-definition lamp unit 110 may include a light source that generates light having a substantially flat intensity distribution, and a spatial light modulator that spatially patterns the light emitted from the light source. Examples of spatial light modulators include DMDs (Digital Micromirror Devices) and liquid crystal devices.

[0087] (Variation 3) In this embodiment, the illuminated portion of the high-beam light distribution pattern PTN was fixed, and only the light-shielding portion SHD was moved up and down; however, this is not limited to this configuration. The second controller 200 moves the group of on pixels corresponding to the illuminated portion surrounding the light-shielding portion SHD in the vertical direction in conjunction with the group of off pixels corresponding to the light-shielding portion SHD. In other words, the entire image data of the light distribution pattern PTN is shifted up and down according to the pitch angle θp.

[0088] (Modification 4) In the embodiments described the generation and correction of a high-beam light distribution pattern PTN including a light-shielding portion SHD, but this disclosure is also applicable to light distribution patterns including a light-reducing portion.

[0089] Figure 12 shows a light distribution pattern PTN including the dimmed portion. Figure 12 shows an example of a camera image IMG and its corresponding light distribution pattern PTN. The ADB controller detects objects OBJ1 to OBJ3 in the camera image IMG. Objects OBJ1 and OBJ2 are signs with high reflectivity, and object OBJ3 is the head of a pedestrian; these are defined as objects to be dimmed. The first controller 160 controls object OBJ i (i=1,2,3) Each position (x i ,y i ) Depending on the position of the dimming portion DIM (H i ,V i The ) is determined. The resulting light distribution pattern PTN includes dimming portions DIM1 to DIM3 at positions corresponding to objects OBJ1 to OBJ3.

[0090] By targeting objects OBJ1 and OBJ2, such as signs with high reflectivity, with the light-reducing (DIM) portion, glare from reflected light can be suppressed for drivers. Additionally, by targeting object OBJ3, which corresponds to the heads of pedestrians and cyclists (referred to as "pedestrians, etc."), with the light-reducing (DIM) portion, glare can be prevented for pedestrians, etc.

[0091] The second controller 200 moves the vertical positions V1 to V3 of the respective dimming portions DIM1 to DIM3 up and down so as to follow the variation of the vehicle body, that is, the variation of the pitch angle. As a result, the relative positional relationship in the vertical direction between the objects OBJ1 to OBJ3 and the corresponding dimming portions DIM1 to DIM3 is always kept unchanged.

[0092] Consider a case where position correction associated with vehicle body vibration is not performed for the dimming portion DIM. An object OBJ with high reflectance j (j=1,2) and the dimming portion DIM j If the relative positional relationship in the vertical direction changes in accordance with the pitching of the vehicle body, the dimming portion DIM reciprocates up and down over the object OBJ when viewed from the driver of the own vehicle. j Above the object OBJ, the dimming portion DIM j reciprocates up and down. In the course of this reciprocation, the illumination portions vertically adjacent to the dimming portion DIM j illuminate the object OBJ by the illumination portions adjacent in the vertical direction, and the driver of the own vehicle will receive glare due to the reflected light. j is illuminated, and the driver of the own vehicle will receive glare from the reflected light. In addition, since the illuminance of the light applied to the object OBJ changes over time, the driver will feel annoyed. According to Modification 4, such a problem can be solved by correcting the position of the dimming portion DIM in accordance with the pitching of the vehicle body. j the illuminance of the light applied to the object OBJ changes over time, so the driver will feel annoyed. According to Modification 4, by correcting the position of the dimming portion DIM in accordance with the pitching of the vehicle body, such a problem can be solved. j for the dimming portion DIM, such a problem can be solved by correcting the position in accordance with the pitching of the vehicle body.

[0093] In addition, if the relative positional relationship in the vertical direction between the object OBJ3, which is the head of a pedestrian, and the dimming portion DIM3 changes in accordance with the pitching of the vehicle body, glare will be imparted to the pedestrian and the like. In contrast, according to Modification 4, it is possible to suppress glare imparted to a pedestrian or the like by correcting the position of the dimming portion DIM3 in accordance with the pitching of the vehicle body.

[0094] (Modification 5) The method by which the second controller 200 shifts the position of the light shielding portion SHD in the vertical direction is not limited to correcting the image data supplied to the light emitting element array 112. For example, the light emitting element array 112 may have a pixel shift function. In this case, the reference image data and the pixel shift amount Δy may be provided to the light emitting element array 112.

[0095] Although this disclosure has been described using specific terminology based on embodiments, embodiments merely illustrate the principles and applications of this disclosure, and many modifications and changes in arrangement are permitted in embodiments, provided they do not deviate from the spirit of this disclosure as defined in the claims. [Industrial applicability]

[0096] This disclosure relates to vehicle lighting equipment. [Explanation of Symbols]

[0097] 100...Lighting system, 110...High-definition lamp unit, 112...Light-emitting element array, 114...Irradiation optical system, PIX...Pixel, 120...Sensor, 150...Optical sensor, 160...First controller, 200...Second controller, 210...Pitch angle calculation unit, 220...Shading position correction unit, 222...Correction amount calculation unit, 224...Correction unit, 2...Virtual vertical screen.

Claims

1. A variable-light distribution lamp that includes a plurality of individually controllable pixels and emits light having a light distribution pattern including a light-shielding portion according to the state of the plurality of pixels, A sensor is provided to detect the dynamic component of the pitch angle of the vehicle while it is in motion, Optical sensors and, A first controller generates light-shielding information, including the target position of the light-shielding portion, based on the output of the optical sensor. A second controller that turns off the group of pixels corresponding to the light-shielding portion among the plurality of pixels, and moves the position of the group of off pixels corresponding to the light-shielding portion vertically in accordance with the dynamic component of the pitch angle of the vehicle body, with reference to the target position of the light-shielding portion. A lighting system characterized by having the following features.

2. The lighting system according to Claim 1, characterized in that the second controller moves the position of the off-pixel group corresponding to the light-shielding portion while maintaining the shape of the off-pixel group.

3. The lighting system according to claim 1, characterized in that the second controller moves the group of on pixels corresponding to the illuminated portion surrounding the light-shielding portion in the vertical direction in conjunction with the group of off pixels.

4. The second controller generates dimming information, including the target position of the dimmed portion, based on the output of the optical sensor. The lighting system according to any one of claims 1 to 3, characterized in that the second controller reduces the brightness of the pixel group corresponding to the dimmed portion among the plurality of pixels compared to the on-pixel group, and moves the position of the pixel group corresponding to the dimmed portion in the vertical direction according to the dynamic component of the pitch angle of the vehicle body, with respect to the target position of the dimmed portion.

5. The lighting system according to any one of claims 1 to 3, characterized in that the target position of the light-shielding portion changes at a frequency lower than 5 Hz, and the dynamic component of the pitch angle includes a frequency higher than 0.5 Hz.

6. The lighting system according to any one of claims 1 to 3, characterized in that the sensor includes a gyro sensor.

7. A control method for a variable light distribution lamp that includes a plurality of individually controllable pixels and emits light having a light distribution pattern including a light-shielding portion according to the state of the plurality of pixels, A step of detecting the dynamic component of the pitch angle of the vehicle while it is in motion, A step of detecting an object located in front of the vehicle, A step of generating a target position for the light-shielding portion based on the position of the object, The steps include: turning off the group of pixels corresponding to the light-shielding portion among the plurality of pixels, and moving the position of the group of off pixels corresponding to the light-shielding portion vertically in accordance with the dynamic component of the pitch angle of the vehicle body, with reference to the target position of the light-shielding portion; A control method characterized by comprising:

8. The control method according to claim 7, characterized in that the position of the off-pixel group corresponding to the light-shielding portion is moved while maintaining the shape of the off-pixel group.

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