Lighting system

Abstract

A high-definition lamp unit (110) includes a plurality of individually controllable pixels PIX and emits lamp light having a light distribution according to the states of the plurality of pixels PIX. A leveling actuator (130) can control the mechanical position of the high-definition lamp unit (110). A controller (200) controls the leveling actuator (130) and the high-definition lamp unit (110) according to the pitch angle of a vehicle body.

Description

[Technical Field]

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

[0002] The beam pattern of a car's headlights is regulated by law to prevent them from glaring on surrounding traffic. The front-to-rear tilt of the vehicle body changes depending on the number of passengers and the weight of the cargo. This changes the angle between the road surface (ground) and the optical axis of the headlight, which in turn changes the vertical illumination range of the headlight. If the illumination range shifts upward, it may cause glare, and if it shifts downward, the illumination range in front of the vehicle narrows.

[0003] To compensate for changes in the optical axis of the headlights due to changes in the front-to-rear tilt of the vehicle body, a leveling actuator is built into the headlight. There is a technology called auto-leveling that automatically controls the leveling actuator according to the tilt of the vehicle body. Auto-leveling acquires the front-to-rear tilt of the vehicle body using sensors installed on the vehicle body, and corrects the optical axis of the lighting unit in the headlight using the leveling actuator to cancel out that tilt. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2017-56828 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] Conventional auto-leveling systems were designed primarily to meet regulations that would not cause glare to surrounding traffic, and glare caused by sudden vehicle vibrations while driving was often tolerated.

[0006] This disclosure is made in the circumstances described herein, and one of its exemplary purposes is to provide a lighting system capable of suppressing glare caused by rapid vehicle vibrations while driving. [Means for solving the problem]

[0007] A lighting system in one aspect of the present disclosure includes a variable-beam lamp that emits light having a light distribution corresponding to the state of a plurality of individually controllable pixels, a leveling actuator capable of controlling the mechanical position of the variable-beam lamp, and a controller that controls the leveling actuator and the variable-beam lamp according to the pitch angle of the vehicle body.

[0008] 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]

[0009] According to one aspect of this disclosure, glare associated with sudden vehicle body vibrations while driving can be suppressed. [Brief explanation of the drawing]

[0010] [Figure 1] This is a block diagram of the lighting system according to Embodiment 1. [Figure 2] Figures 2(a) and 2(b) illustrate the pitch angle θp of the vehicle body. [Figure 3] This is a functional block diagram of the controller. [Figure 4] This is a diagram illustrating an example of a vehicle in motion. [Figure 5] This figure shows the waveform of the dynamic pitch angle θd and the waveform of the correction amount ΔV corresponding to the driving scene in Figure 4. [Figure 6]This is a diagram showing the light rays corresponding to the cutoff line of the headlamp light beam in the driving scene of Figure 4. [Figure 7] Figures 7(a) to 7(c) are diagrams showing examples of the relationship (control characteristic) between the dynamic pitch angle θd and the correction amount ΔV. [Figure 8] This is a diagram illustrating glare that may occur as a result of optical axis correction during nose dive. [Figure 9] Figures 9(a) to 9(c) are diagrams showing examples of the relationship (control characteristic) between the dynamic pitch angle θd and the correction amount ΔV. [Figure 10] This is a diagram illustrating optical axis correction based on the control characteristic of Figure 9(a). [Figure 11] Figures 11(a) to 11(d) are diagrams showing examples of the relationship (control characteristic) between the dynamic pitch angle θd and the correction amount ΔV. [Figure 12] Figures 12(a) to 12(c) are diagrams explaining examples of control of the light distribution intensity distribution. [Figure 13] This is a block diagram of a lamp system according to Embodiment 2. [Figure 14] This is a functional block diagram of a controller according to Example 1. [Figure 15] This is a diagram for explaining the second pitch angle θa. [Figure 16] This is a diagram showing the second pitch angle θa sensed by the second sensor. [Figure 17] This is a functional block diagram of a controller according to Example 3. [Figure 18] This is a diagram showing an example of a design of a vehicle equipped with a lamp system. [Figure 19] This is a diagram showing another example of a design of a vehicle equipped with a lamp system. [Figure 20] This is a diagram illustrating signal transmission and processing in the design of Figure 18. [Figure 21] This is a diagram illustrating signal transmission and processing in the design of Figure 19. [Figure 22] This is a diagram illustrating prediction of the first pitch angle θj based on FFT. [Figure 23]This is a diagram showing an example of the structure of a headlamp. [Figure 24] This figure shows yet another example of a vehicle design equipped with a lighting system. [Figure 25] This is a diagram showing an example of the structure of a headlamp. [Figure 26] This is a diagram showing an example of the structure of a headlamp. [Figure 27] This is a diagram showing an example of the structure of a headlamp. [Figure 28] This is a block diagram of a lighting system compatible with hybrid leveling control. [Figure 29] This diagram illustrates a hybrid control system combining electronic and mechanical leveling. [Figure 30] This is a block diagram showing an example configuration of a lighting system controller. [Figure 31] This is a block diagram of a lighting system compatible with hybrid leveling control. [Figure 32] Figures 32(a) and (b) illustrate the light distribution control using the lighting system shown in Figure 31. [Figure 33] Figure 31 shows an example of the structure of a lighting system. [Figure 34] Figure 31 is a perspective view of the lighting system. [Modes for carrying out the invention]

[0011] (Summary of the 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.

[0012] A lighting system according to one embodiment includes a variable-beam lamp that emits light having a light distribution corresponding to the state of a plurality of individually controllable pixels, a leveling actuator capable of controlling the mechanical position of the variable-beam lamp, and a controller that controls the leveling actuator and the variable-beam lamp according to the pitch angle of the vehicle body.

[0013] By combining mechanical leveling using leveling actuators with electronic leveling through pixel control of variable-beam lamps, flexible and high-speed leveling control becomes possible.

[0014] In one embodiment, the controller may control a leveling actuator according to the static component of the vehicle body's pitch angle and control a variable light distribution lamp according to the dynamic component of the vehicle body's pitch angle.

[0015] In one embodiment, the lighting system may further include a first sensor, which may include a gyro sensor. The controller may control a variable-light distribution lamp according to the output of the first sensor.

[0016] In one embodiment, the lighting system may further include a second sensor, which may include a vehicle height sensor or an acceleration sensor. The controller may control the leveling actuator in response to the output of the second sensor.

[0017] In one embodiment, the lighting system may further include a fixed-beam lamp that forms a fixed light distribution, and a lamp bracket that supports the fixed-beam lamp and the variable-beam lamp. The leveling actuator may be able to control the position of the lamp bracket.

[0018] (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.

[0019] 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.

[0020] 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.

[0021] (Embodiment 1) Figure 1 is a block diagram of the lighting system 100 according to Embodiment 1. The lighting system 100 is a headlamp mounted on an automobile that illuminates the field of view in front of the vehicle with light. The tilt angle in the front-rear direction of an automobile changes according to the front-rear weight balance. The tilt angle in the front-rear direction corresponds to the rotation around a horizontal axis that extends from left to right on the vehicle body, and is called the pitch angle θp.

[0022] The lighting system 100 has a function (auto-leveling function) that automatically adjusts the optical axis of the headlamp in the pitch direction according to the pitch angle θp.

[0023] The lighting system 100 includes a high-definition lamp unit 110, a sensor 120, and a controller 200.

[0024] In this embodiment, the high-definition lamp unit 110 is a variable-distribution lamp configured to illuminate part or all of the low-beam region. In addition to part or all of the low-beam region, the high-definition lamp unit 110 may also cover 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 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.

[0025] 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.

[0026] 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.

[0027] Figure 1 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. A light distribution pattern PTN is formed on the virtual vertical screen 2 by the light from the high-definition lamp unit 110. 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 and the corresponding illumination 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.

[0028] The light distribution pattern PTN includes a cutoff line CL. In this example, the light distribution pattern PTN includes a horizontal cutoff line CLa and an oblique cutoff line CLb, which intersect at the elbow point LB.

[0029] In this embodiment, the controller 200 corrects the optical axis of the low beam in the pitch angle direction in response to fluctuations in the pitch angle θp caused by various factors while the vehicle is stationary and in motion.

[0030] Figures 2(a) and 2(b) illustrate the pitch angle θp of the vehicle body. Figure 2(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 a reference line 22 of the vehicle body 20, and the direction in which the reference line 22 points upward (the direction of nose-up) is taken as positive.

[0031] Figure 2(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

[0032] (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).

[0033] 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.

[0034] In conventional leveling control systems, vibrations exceeding approximately 0.5 Hz were filtered out as noise. Therefore, in conventional systems, among (i) to (iii), fast pitch angle fluctuations exceeding the filter's cutoff frequency were excluded from correction. As a result, when the vehicle's pitch angle changed sharply due to steep unevenness in the road surface while driving, the low beam's cutoff line would sink or rise.

[0035] In contrast, 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 actively included in the correction. In this specification, the optical axis correction for correcting pitch angle fluctuations during driving is referred to as dynamic leveling.

[0036] Returning to Figure 1, 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.

[0037] 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.

[0038] Controller 200 is an ECU (Electronic Control Unit) that integrates functions related to optical axis correction and performs processing related to dynamic leveling. ECU 0 may be a dedicated leveling ECU (also called a leveling ECU), an ECU integrated with a controller that has other functions, or it may be configured by dividing it into multiple ECUs.

[0039] The functions of the controller 200 may be implemented by software processing, by hardware processing, or by a combination of software and hardware processing. Specifically, software processing may involve the CPU (Central Processing Unit) and MPU. (Micro Processing Unit), processors such as microcontrollers (hardware) This is implemented as a combination of a processor (hardware) and a software program. The controller 200 may also be a combination of multiple processors (microcontrollers).

[0040] Hardware processing is specifically implemented using hardware such as ASICs (Application Specific Integrated Circuits), controller ICs, and FPGAs (Field Programmable Gate Arrays).

[0041] The 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.

[0042] The controller 200 then moves the position of the cutoff line CL of the light distribution pattern PTN (the position in the vertical direction V, i.e., the optical axis) relative to a predetermined position v0, according to the dynamic component θd of the pitch angle θp of the moving vehicle body. Conventional leveling control only moves the optical axis downward in order to suppress glare. In contrast, the dynamic leveling according to this embodiment actively moves the position of the cutoff line CL not only downward but also upward.

[0043] Controlling the position of the cutoff line CL includes (1) fixing the lower end of the lamp's light distribution and only changing the position of the cutoff line vertically, and (2) changing the position of the lower end of the lamp's light distribution vertically in accordance with the position of the cutoff line, in other words, moving the entire light distribution of the lamp vertically.

[0044] The controller 200 moves the cutoff line CL downward in response to a positive dynamic pitch angle θd. In this embodiment, the controller 200 further actively moves the cutoff line CL upward in response to a negative dynamic pitch angle θd.

[0045] More specifically, the controller 200 moves the position of the cutoff line CL upward and downward relative to a predetermined position V0 so as to cancel out the dynamic component θd of the pitch angle θp. The predetermined position V0 is the vertical coordinate where the cutoff line CL should be located when the variation in the pitch angle θp is zero.

[0046] For example, the controller 200 changes the on / off boundary 116 of multiple pixels PIX of the light-emitting element array 112 in order to raise or lower the cutoff line CL on the virtual vertical screen 2. The number of pixels to shift the boundary 116 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.

[0047] Figure 3 is a functional block diagram of the controller 200. The controller 200 comprises a pitch angle calculation unit 210 and a cutoff line control unit 220.

[0048] 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.

[0049] The cutoff line control unit 220 moves the position of the cutoff line CL up and down based on the dynamic pitch angle θd. The cutoff line control 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 cutoff line CL 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 cutoff line CL, and a negative correction amount ΔV corresponds to a downward shift of the cutoff line CL. The correction unit 224 controls the light-emitting element array 112 so that the cutoff line CL moves by the correction amount ΔV.

[0050] For example, the light-emitting element array 112 has an interface that takes image data as input, specifying whether multiple pixels PIX are on or off (or their brightness). In this case, the correction unit 224 may shift the position of the boundary 116 between on and off pixels 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 position of the cutoff line CL (boundary 116) 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.

[0051] The correction unit 224 may shift the position (height) of the boundary between on-pixels and off-pixels corresponding to the cutoff line CL, as well as the position (height) of the boundary between on-pixels and off-pixels corresponding to the lower end of the light distribution pattern, up or down by a number of pixels Δy corresponding to the correction amount ΔV. In other words, the correction unit 224 may shift the entire light distribution pattern up or down by a number of pixels Δy corresponding to the correction amount ΔV.

[0052] The above describes the configuration of the lighting system 100. Next, we will explain its operation.

[0053] Figure 4 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 4 shows the posture of vehicle 30 at multiple times t0 to t4. Each time point t0 to t4 shows the following state.

[0054] 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.

[0055] 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 t2 is a negative value θd3.

[0056] Figure 5 shows the waveform of the dynamic pitch angle θd and the waveform of the correction amount ΔV corresponding to the driving scene in Figure 4. As shown in Figure 4, the dynamic pitch angle θd swings in the positive direction, then in the negative direction, and eventually returns to 0.

[0057] A correction amount ΔV is generated in response to this variation in the dynamic pitch angle θd.

[0058] Figure 6 shows the light rays corresponding to the cutoff line of the headlamp light in the driving scene shown in Figure 4. By adaptive light distribution control that follows the dynamic pitch angle θd, the light rays 32 of the headlamp can always be kept at a constant angle with respect to the road surface 10.

[0059] The above describes the operation of the lighting system 100. With this lighting system 100, as shown at time t1 in Figure 6, when the rear of the vehicle 30 sinks, glare can be prevented by lowering the cutoff line. Also, as shown at time t3 in Figure 6, when the front of the vehicle 30 sinks, the distant field of view can be prevented from becoming darker by raising the cutoff line.

[0060] 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 cutoff line 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.

[0061] 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 controller 200 controls the high-definition lamp unit 110 so that the angle between the light ray 32 corresponding to the cutoff line of the lamp and the road surface 10 remains constant, according to the deviation θd.

[0062] The following describes an example of light distribution control that follows the variation in pitch angle θp by the controller 200.

[0063] Figures 7(a) to 7(c) show examples of the relationship between the dynamic pitch angle θd and the correction amount ΔV (control characteristics).

[0064] When the correction amount ΔV is the amount of movement of the cutoff line CL 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)

[0065] Therefore, in the simplest form, as shown in Figure 7(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 boundary 116 corresponding to the cutoff line on the image data is shifted vertically so that this correction amount ΔV is obtained (Figure 4). 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)

[0066] 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 7(b).

[0067] Alternatively, even when using a simple optical system, control characteristics like those shown in Figure 7(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.

[0068] 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 7(c).

[0069] Depending on the driving conditions, the upward movement of the cutoff line may be disabled. For example, if the dynamic pitch angle θd contains frequency components that exceed the response speed of the controller 200, glare can be suppressed by disabling the upward movement of the cutoff line.

[0070] Alternatively, the movement of the cutoff line in the downward direction as well as the upward direction may be disabled. If road surface irregularities occur continuously (for example, for a period of 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, when 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 a high-definition lamp unit 110 that can control the intensity distribution in multiple shades, it is better to return to the original state gradually by applying blurring or gradation.

[0071] (Asymmetrical control) Actively raising the optical axis upwards during nose dive has the effect of maintaining a clear view of distant objects. On the other hand, if control delays occur or there are unexpected changes in the road surface, it may cause glare to surrounding traffic.

[0072] Figure 8 illustrates the glare that may occur as a result of optical axis correction during nose dive. In this example, vehicle 30 is traveling from left to right on the page and is shown passing over a depression 16 on the road surface 10. Figure 4 shows the attitude of vehicle 30 at multiple times t0 to t4. Each time t0 to t4 represents the following state.

[0073] Time t0: Driving just before indentation 16. Time t1: Front wheel is stuck in recess 16. Time t2: The front wheel has finished passing over the indentation 16. Time t3: The rear wheel is dented and has dropped to position 16. Time t4: The rear wheel has finished passing over the dent 16.

[0074] When the vehicle enters a nose-dive state at time t1, the position of the cutoff line is corrected so that the optical axis points upward. At the following time t2, the vehicle's attitude returns to normal, and θd = 0. At this time, the controller 200 attempts to return the cutoff line to its original predetermined position v0. However, if there is a control delay, the cutoff line will not return completely to the predetermined position v0, and will be positioned above the predetermined position v0. As a result, the light will be emitted above the horizontal, potentially causing glare.

[0075] Furthermore, if the aircraft enters a nose-up state at time t3, the controller 200 attempts to adjust the position of the cutoff line downwards from the predetermined position v0 so that the optical axis points downwards. In this case as well, if there is a control delay, the cutoff line may not lower completely to the target position corresponding to the current attitude, causing the light to be emitted above the horizontal and potentially causing glare.

[0076] The problem described with reference to Figure 8 can be solved by the asymmetrical control described below.

[0077] In the examples in Figures 7(a) to 7(c), the control characteristics were the same whether the dynamic pitch angle θd was positive or negative; in other words, whether the cutoff line CL moved upward from a predetermined position or downward from a predetermined position. In contrast, asymmetric vertical control introduces an asymmetry corresponding to the sign (direction) of the dynamic pitch angle θd.

[0078] In other words, the control characteristics of the cutoff line CL may differ depending on whether the dynamic pitch angle θd is positive or negative; in other words, whether the cutoff line CL moves upward from a predetermined position or downward from a predetermined position. The control characteristics here refer to the relationship between the dynamic pitch angle θd and the correction amount ΔV, and examples include the function f() mentioned above and the parameters that define it (gain and order).

[0079] Figures 9(a) to 9(c) show examples of the relationship between the dynamic pitch angle θd and the correction amount ΔV (control characteristics). In the example in Figure 9(a), similar to Figure 7(a), the control characteristics are linear, but the gain (slope) is different when θd>0 (nose-up) and θd<0 (nose-dive). In other words, for dynamic pitch angles θd with the same absolute value but different signs, the correction amount ΔV may be relatively large when θd>0, and relatively small when θd<0.

[0080] Specifically, in the region where θd > 0, there is a slope (reference gain g0) based on the distance L, as shown in equation (2). This ensures that glare is reliably prevented.

[0081] On the other hand, in the region where θd < 0, the slope is smaller than the slope based on the reference gain g0 compared to when θd > 0. In other words, during a nose dive, the amount by which the optical axis is pointed upward is suppressed. This makes it possible to suppress glare to surrounding traffic participants in the event of a control delay when the aircraft assumes a nose-up attitude immediately after a nose dive. In other words, the problem explained with reference to Figure 8 can be solved.

[0082] Figure 10 illustrates the optical axis correction based on the control characteristics of Figure 9(a). Figure 10 shows the same driving scene as Figure 8, but with the control characteristics of Figure 9(a) applied. When a nose dive occurs at time t1, the position of the cutoff line is corrected so that the optical axis points upward. At this time, since θd < 0, the correction amount ΔV is smaller than the correction amount in Figure 8. The dashed line represents the optical axis in Figure 8, and the solid line represents the optical axis based on the control characteristics of Figure 9(a).

[0083] At the following time t2, the vehicle's attitude returns to its original position, and θd = 0. At this time, the controller 200 attempts to return the cutoff line to its original predetermined position v0. Because the correction amount ΔV during the preceding nose dive was small, the cutoff line returns to the predetermined position v0 even with a control delay. As a result, the light is kept below horizontal, and glare can be suppressed.

[0084] Return to Figure 9(b). In the example in Figure 9(b), the negative threshold θ TH It is defined that θd > θ TH Within this range, the slope is based on the reference gain g0. On the other hand, θd < θ TH Within this range, the slope is smaller than that based on the reference gain g0.

[0085] This allows for a clear view of distant objects by correcting the optical axis with the reference gain during shallow nose dives. Conversely, during deep nose dives, the amount the optical axis is directed upward is suppressed. This reduces glare to surrounding traffic drivers in situations where a control delay occurs when the aircraft assumes a nose-up attitude immediately after a nose dive. In other words, it solves the problem explained in Figure 8.

[0086] In the example shown in Figure 9(c), in the region where θd ≈ 0, the slope is based on the reference gain g0, but in the range where θd > 0, the slope increases as the amount of variation (absolute value) increases. As a result, in situations with a large nose-up, the optical axis is directed downward by a larger amount than originally required. This allows for more reliable suppression of glare.

[0087] Conversely, in the range θd < 0, the larger the amount of variation (absolute value), the smaller the slope. This results in the optical axis being pointed upward by a smaller amount than originally required in a deep nose dive situation. This suppresses glare to surrounding traffic drivers in the event of a control delay when the aircraft immediately changes to a nose-up attitude. In other words, it solves the problem explained in Figure 8.

[0088] When considering the control characteristics, if we consider a transfer function H(s) with a dynamic pitch angle θd as input and a correction amount ΔV as output, the transfer function may include a filter element, and therefore the filter characteristics may differ when the cutoff line CL moves upward from a predetermined position compared to when it moves downward from a predetermined position.

[0089] Figures 11(a) to (d) show examples of the relationship between the dynamic pitch angle θd and the correction amount ΔV (control characteristics). In Figure 11(a), the frequency characteristics (cutoff frequency) are the same when θd > 0 and when θd < 0, and only the gain g differs.

[0090] In Figure 11(b), the gain is the reference gain g0 in both the case when θd>0 and the case when θd<0, but the frequency characteristics are different. Specifically, when θd>0 (nose-up), the wide frequency band of the dynamic pitch angle θd is corrected to reliably prevent glare. When θd<0 (nose-dive), the frequency band corrected for the dynamic pitch angle θd is narrowed. This reduces the risk of glare due to control delay.

[0091] Similar to Figure 11(b), Figure 11(c) shows that while the gain is the reference gain g0 for both θd>0 and θd<0, the frequency characteristics differ. In Figure 11(c), when θd<0 (nose dive), the frequency bandwidth corrected by the dynamic pitch angle θd is narrowed, but the bandwidth being corrected is wider than in Figure 11(b).

[0092] In Figure 11(d), both the gain g and the frequency characteristics differ when θd > 0 and when θd < 0.

[0093] Alternatively, the speed at which the cutoff line CL moves up and down may be varied depending on the vehicle's posture. Specifically, the speed at which the cutoff line moves upward may be slower than the speed at which it moves downward. This reduces the likelihood of glare after the cutoff line CL has been corrected upward.

[0094] Furthermore, depending on the driving conditions, the upward movement of the cutoff line may be disabled. For example, if the dynamic pitch angle θd contains frequency components that exceed the response speed of the controller 200, glare can be suppressed by disabling the upward movement of the cutoff line.

[0095] Alternatively, the movement of the cutoff line in the downward direction as well as the upward direction may be disabled. If road surface irregularities occur continuously (for example, for a period of 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, when 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 a high-definition lamp unit 110 that can control the intensity distribution in multiple shades, it is better to return to the original state gradually by applying blurring or gradation.

[0096] If the high-definition lamp unit 110 can form a multi-gradation light distribution, the controller 200 may, in addition to moving the cutoff line (leveling control), also control the intensity distribution of the light distribution (illuminance distribution).

[0097] Figures 12(a) to (c) illustrate examples of controlling the intensity distribution of light distribution. Figure 12(a) is the most standard example of light distribution control, in which only the cutoff line CL is moved upward, and the illuminance remains virtually constant. In Figures 12(a) to (c), illuminance is indicated by the density of the hatching, with higher density indicating higher illuminance.

[0098] In the example shown in Figure 12(b), when the cutoff line CL is located above the predetermined position v0, the controller 200 reduces the illuminance in the range above the predetermined position v0 to the illuminance (default value) as in Figure 12(a). This ensures that the driver's field of view of distant objects is maintained while reducing glare.

[0099] In the example shown in Figure 12(c), when the cutoff line CL is located above the predetermined position v0, the light intensity distribution has a gradient in the range above the predetermined position V0, where the illuminance gradually darkens as it goes upwards. This ensures that the driver's field of vision is maintained at a distance while minimizing glare.

[0100] (Variation 1) A modified example relating to Embodiment 1 will be described.

[0101] (Example 1.1) 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.

[0102] (Example 1.2) 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.

[0103] (Modified example 1.3) The method by which the controller 200 shifts the position of the cutoff line CL vertically is not limited to that described in the embodiment. For example, the light-emitting element array 112 may have a pixel shift function. In this case, the light-emitting element array 112 is provided with reference image data and a pixel shift amount Δy.

[0104] (Example 1.4) Control of the optical axis, i.e., control of the cutoff line height, is not limited to pixel control of the high-definition lamp unit 110 (electronic leveling). For example, a normal low-beam unit may be configured to be controllable by a high-speed leveling actuator, and the height of the cutoff line may be controlled by changing the tilt of the low-beam unit (called mechanical leveling). Alternatively, the position of the light-emitting element array 112 may be configured to be mechanically shiftable.

[0105] (Embodiment 2) Figure 13 is a block diagram of the lighting system 100 according to Embodiment 2. The lighting system 100 is a headlamp mounted on an automobile that illuminates the field of view in front of the vehicle. The tilt angle in the front-rear direction of an automobile changes according to the front-rear weight balance. The tilt angle in the front-rear direction corresponds to the rotation around a horizontal axis that extends from left to right on the vehicle body, and is called the pitch angle θp.

[0106] The lighting system 100 has a function (auto-leveling function) that automatically adjusts the optical axis of the headlamp in the pitch direction according to the pitch angle θp.

[0107] The lighting system 100 includes a high-definition lamp unit 110, a first sensor 120, a second sensor, and a controller 200.

[0108] In this embodiment, the high-definition lamp unit 110 is a variable-distribution lamp configured to illuminate part or all of the low-beam region. In addition to part or all of the low-beam region, the high-definition lamp unit 110 may also cover 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 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.

[0109] 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.

[0110] 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.

[0111] Figure 13 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. A light distribution pattern PTN is formed on the virtual vertical screen 2 by the light from the high-definition lamp unit 110. 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 and the corresponding illumination 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.

[0112] The light distribution pattern PTN includes a cutoff line CL. In this example, the light distribution pattern PTN includes a horizontal cutoff line CLa and an oblique cutoff line CLb, which intersect at the elbow point LB.

[0113] In this embodiment, the controller 200 corrects the optical axis of the low beam in the pitch angle direction in response to fluctuations in the pitch angle θp caused by various factors while the vehicle is stationary and in motion.

[0114] For example, the controller 200 changes the on / off boundary 116 of multiple pixels PIX of the light-emitting element array 112 in order to raise or lower the cutoff line CL on the virtual vertical screen 2. The number of pixels to shift the boundary 116 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.

[0115] In this embodiment, the controller 200 performs dynamic leveling targeting frequency components of pitch angle fluctuations exceeding 0.5 Hz, which were conventionally removed as noise, similar to the first embodiment.

[0116] Furthermore, in the present embodiment, the controller 200 corrects the optical axis also in accordance with the static pitch angle (stopped vehicle posture angle) θs shown in Fig. 2(a). Specifically, control is performed to direct the lamp optical axis downward in response to a static load change of the stopped vehicle. This is referred to as static leveling. Static leveling has been performed in conventional vehicle lamps using a G sensor (acceleration sensor) or a vehicle height sensor.

[0117] To perform static leveling and dynamic leveling, it is necessary to accurately detect high-speed fluctuations and static or low-speed fluctuations of the pitch angle.

[0118] In the present embodiment, a first sensor 120 and a second sensor 122 are provided for accurate detection of the pitch angle θp.

[0119] The first sensor 120 is provided so as to be capable of mainly detecting the dynamic component θd of the pitch angle θp during traveling of the vehicle body. The first sensor 120 includes a gyro sensor. The mounting direction of the gyro sensor is arbitrary, but it is preferably mounted such that one detection axis thereof faces the left-right horizontal direction of the vehicle body, and generates a first detection signal S1 indicating the angular velocity ωp of the rotational motion around this detection axis. The gyro sensor may be a three-axis type or a single-axis type.

[0120] The second sensor 122 is an acceleration sensor (G sensor). The second sensor 122 outputs a detection signal S2 including accelerations α for each of the three axes x , α y , α z . During a stationary state or constant velocity motion of the vehicle, the combined vector of the three-axis accelerations α x , α y , α z is oriented in the direction of gravity. When the vehicle performs acceleration motion, the combined vector of the three-axis accelerations α x , α y , α z gives a combined vector of gravity and the acceleration vector of the vehicle body.

[0121] The first sensor 120 and the second sensor 122 may be 6-axis sensors that integrate an accelerometer and a gyroscope.

[0122] The controller 200 is an ECU (Electronic Control Unit) that integrates functions related to optical axis correction, including static leveling and dynamic leveling processing. The controller 200 may be a dedicated ECU for leveling (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.

[0123] The functions of the controller 200 may be implemented by software processing, by hardware processing, or by a combination of software and hardware processing. Specifically, software processing may involve the CPU (Central Processing Unit) and MPU. (Micro Processing Unit), processors such as microcontrollers (hardware) This is implemented as a combination of a processor (hardware) and a software program. The controller 200 may also be a combination of multiple processors (microcontrollers).

[0124] Hardware processing is specifically implemented using hardware such as ASICs (Application Specific Integrated Circuits), controller ICs, and FPGAs (Field Programmable Gate Arrays).

[0125] The controller 200 detects the vehicle's pitch angle θp in response to the detection signal S1 generated by the first sensor 120 and the second detection signal S2 generated by the second sensor 122, and controls the height of the light distribution cutoff line according to the pitch angle θp. As shown in Figures 2(a) and (b), the pitch angle θp includes the static pitch angle θs (stationary vehicle attitude angle) and the dynamic pitch angle θp.

[0126] This section describes an example configuration and processing of the controller 200.

[0127] (Example 1) Figure 14 is a functional block diagram of the controller 200A according to Embodiment 1. The controller 200A comprises a pitch angle calculation unit 210 and a cutoff line control unit 220.

[0128] The pitch angle calculation unit 210 generates angular information necessary for optical axis correction (leveling control), i.e., the pitch angle θp, based on the two detection signals S1 and S2.

[0129] The pitch angle calculation unit 210 includes an integrator 212 and an acceleration direction calculation unit 214. The integrator 212 calculates the first pitch angle θj by integrating the angular velocity ωp indicated by the first detection signal S1.

[0130] The acceleration direction calculation unit 214 calculates the acceleration α indicated by the second detection signal S2. x , α y , α z Based on this, the second pitch angle θa, which indicates the acceleration direction α, is calculated.

[0131] Figure 15 illustrates the second pitch angle θa. Consider the case when the vehicle is stationary or in constant velocity motion. The acceleration direction α detected by the acceleration direction calculation unit 214 coincides with the gravity direction G when the vehicle is stationary or in constant velocity motion.

[0132] For ease of understanding, the x, y, and z axes of the acceleration sensor are assumed to be parallel to the X, Y, and Z axes of the vehicle body. The vehicle body's X axis is assumed to be in the direction of travel, the Y axis in the left-right direction, and the Z axis in the up-down direction. Also for ease of understanding, it is assumed that no acceleration occurs in the y direction.

[0133] The second pitch angle θa is taken as the angle between the z-axis of the acceleration sensor and the acceleration vector α. In this case, the second pitch angle θa becomes the angle between a straight line parallel to the road surface and the X-axis of the vehicle body, and coincides with the stationary pitch angle θs shown in Figure 2(a).

[0134] Returning to Figure 14, the pitch angle calculation unit 210 may include a filter (low-pass filter or band-pass filter) to remove noise components. However, in order to correct high-speed pitch angle fluctuations, the cutoff frequency should be set so that the frequency component to be corrected can pass through. Therefore, the cutoff frequency should be set between the noise frequency and the maximum frequency of the frequency to be corrected. For example, if the noise component around 100Hz is large, the cutoff frequency needs to be set so that 100Hz is sufficiently attenuated, and it should be about 1 / 2 to 1 / 3 of the noise frequency of 100Hz, for example, 50Hz.

[0135] In Example 1, the second pitch angle θa is associated with the static pitch angle θs, and the first pitch angle θj is associated with the dynamic pitch angle θd. Specifically, the static pitch angle θs (stationary vehicle attitude angle) can be estimated based on the second pitch angle θa when the vehicle is stationary. Since the acceleration sensor acquires the direction and inclination of gravitational acceleration, it cannot distinguish whether the vehicle is tilted on a slope or due to a load, even when stationary. However, the stationary vehicle attitude angle (static pitch angle θs) can be estimated using known technology (for example, Patent Document 3).

[0136] Furthermore, assuming that the stationary vehicle attitude angle (static pitch angle θs) does not change while the vehicle is in motion, the first pitch angle θj can be taken as the dynamic pitch angle θd. For example, if the integral value is reset while the angular velocity ωp in the pitch direction is 0, and integration is started when the angular velocity ωp becomes non-zero, the integral value will represent the dynamic pitch angle θd.

[0137] The cutoff line control unit 220 performs static leveling based on the static pitch angle θs and dynamic leveling based on the dynamic pitch angle θp. For example, the cutoff line control unit 220 controls the reference position V0 of the cutoff line CL based on the static pitch angle θs. The cutoff line control unit 220 also shifts the cutoff line CL vertically relative to the reference position V0 based on the dynamic pitch angle θd.

[0138] Dynamic leveling may be applied only when the dynamic pitch angle θp based on the first pitch angle θj is greater than a predetermined threshold.

[0139] There are two possible methods for leveling control by the cutoff line control unit 220. One is to directly control the optical axis based on the pitch angle θp. This is called unified control. In unified control, the position of the cutoff line CL can be set using the pitch angle θp as the control angle. In Example 1, the pitch angle θp can be generated by adding θj and θs.

[0140] Another leveling control method involves controlling the optical axis by separating the static pitch angle θs and the dynamic pitch angle θd. This is called separation control. Separation control will be explained below.

[0141] The cutoff line control unit 220 includes a correction amount calculation unit 222 and a correction unit 224. In the case of isolated control, the correction amount calculation unit 222 calculates the reference position V0 of the cutoff line CL on the virtual vertical screen 2 based on the static pitch angle θs. The correction amount calculation unit 222 also calculates the vertical movement amount (correction amount ΔV) of the cutoff line CL based on the dynamic pitch angle θd. In this embodiment, a positive correction amount ΔV corresponds to an upward shift of the cutoff line CL, and a negative correction amount ΔV corresponds to a downward shift of the cutoff line CL. The correction unit 224 controls the light-emitting element array 112 so that the cutoff line CL moves by the correction amount ΔV from the reference position V0.

[0142] For example, the light-emitting element array 112 has an interface that takes image data as input, specifying whether multiple pixels PIX are on or off (or their brightness). In this case, the correction unit 224 may shift the position of the boundary 116 between on and off pixels 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 position of the cutoff line (boundary 116) 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.

[0143] The correction unit 224 may shift the position (height) of the boundary between on-pixels and off-pixels corresponding to the cutoff line CL, as well as the position (height) of the boundary between on-pixels and off-pixels corresponding to the lower end of the light distribution pattern, up or down by a number of pixels Δy corresponding to the correction amount ΔV. In other words, the correction unit 224 may shift the entire light distribution pattern up or down by a number of pixels Δy corresponding to the correction amount ΔV.

[0144] (Example 2) The basic configuration of the controller in Example 2 is the same as in Figure 14. In Example 2, the static pitch angle θs is determined based on the second pitch angle θa, as in Example 1. In other words, static leveling is the same as in Example 1.

[0145] In Example 2, the dynamic leveling differs from that in Example 1. Specifically, the dynamic pitch angle θd used in the dynamic leveling is determined not only by the first pitch angle θj, but also by the variation of the second pitch angle θa.

[0146] Figure 16 shows the second pitch angle θa sensed by the second sensor 122. Section T1 indicates the vehicle is stationary on a flat road surface. The second pitch angle θa while the vehicle is stationary represents the static pitch angle (stationary vehicle attitude angle) θs.

[0147] Section T2 represents travel on a flat road. The second pitch angle θa fluctuates slightly but remains essentially constant.

[0148] Section T3 represents an uphill slope with a gradient of φ1. The second pitch angle θa increases by φ1 compared to the static pitch angle θs. However, the change in the second pitch angle θa due to the slope does not affect the vehicle's posture and is therefore unrelated to the dynamic pitch angle θd, and leveling control does not occur.

[0149] Section T4 represents a downhill slope with a gradient of φ2. The second pitch angle θa decreases by φ2 compared to the static pitch angle θs. However, the change in the second pitch angle θa due to the slope does not affect the vehicle's posture and is therefore unrelated to the dynamic pitch angle θd, so leveling control does not occur.

[0150] Section T5 represents the acceleration period. This acceleration is normal and is distinct from the rapid acceleration described later. During the acceleration period, the nose lifts and a change in attitude occurs. As a result, the second pitch angle θa becomes larger than the stationary pitch angle θs.

[0151] The cutoff line control unit 220 uses the variation range θa-θs of the second pitch angle θa as the dynamic pitch angle θd, and corrects the optical axis based on the dynamic pitch angle θd. This is called low-speed dynamic leveling.

[0152] Section T6 involves traveling on an uneven road surface. During travel on uneven terrain, the second pitch angle θa oscillates around the static pitch angle θs. The cutoff line control unit 220 uses the fluctuating component θa-θs of the second pitch angle θa as the dynamic pitch angle θd, and moves the optical axis vertically based on the dynamic pitch angle θd. This is called high-speed dynamic leveling.

[0153] Fluctuations in the dynamic pitch angle θd while driving on an uneven road surface are also detected as a first pitch angle θj. In this case, leveling control may be performed based on either θj or (θa-θd). For example, if the second pitch angle θa is estimated to contain noise, leveling control may be performed based on the first pitch angle θj.

[0154] Alternatively, leveling control may be performed by averaging θj and (θa-θd).

[0155] (Example 3) Figure 17 is a functional block diagram of controller 200B according to Embodiment 3. Controller 200A includes a pitch angle calculation unit 210 and a cutoff line control unit 220, similar to Figure 14.

[0156] The pitch angle calculation unit 210 includes an integrator 212, an acceleration direction calculation unit 214, a combining unit 216, and a driving condition determination unit 218. The combining unit 216 generates the pitch angle θp, which is the angular information necessary for optical axis correction (leveling control), by combining the first pitch angle θj and the second pitch angle θa. As described above, the pitch angle θp includes the static pitch angle θs and the dynamic pitch angle θd.

[0157] The cutoff line control unit 220 may perform collectively control or separate control, but here we will assume that it performs collectively control.

[0158] An example of processing in the synthesis unit 216 will be explained. The composite unit 216 estimates the pitch angle θp by weighting and adding the first pitch angle θj and the second pitch angle θa using equation (1). θp = α·θj + β·θa …(1)

[0159] For example, β = 1 - α may also be used, and the synthesis in that case is expressed by equation (2). θp=α·θj+(1-α)·θa …(2)

[0160] Here, the weighting coefficients α and β (=1-α) change dynamically and adaptively according to the driving environment (driving scene) and the state of the vehicle (hereinafter referred to as driving conditions). The driving condition determination unit 218 determines the driving conditions based on information from the vehicle (referred to as vehicle information) and / or based on sensor information. Examples of vehicle information include vehicle speed, steering angle, camera image, map information, infrastructure information, suspension settings, and vehicle weight. Sensor information includes at least one of the first detection signal S1, the second detection signal S2, and the first pitch angle θj and second pitch angle θa based on them. Therefore, the weighting coefficient α can be set according to at least one of the vehicle information and sensor information.

[0161] In other words, during normal driving, when the outputs of the first sensor 120 and the second sensor 122 continue to change gradually, leveling control based on the output of the second sensor 122 is enabled. Conversely, under driving conditions in which the first sensor 120 detects a steep pitch angle fluctuation, leveling control based on the first pitch angle θj is enabled in order to follow the high-speed pitch angle fluctuation.

[0162] This section explains the relationship between several driving conditions and the appropriate weighting coefficients for each.

[0163] (1) Passing over large steps or uneven surfaces For example, suppose the synthesis unit 216 determines that a large step is being passed based on at least one of the vehicle information and sensor information. In this case, it is preferable to set α=1 and perform leveling control (dynamic leveling) based on the first pitch angle θj. Since the pitch angle fluctuation associated with passing over a step includes high-frequency components, the gyro sensor is considered to be more accurate than the G sensor. Therefore, by setting α=1, accurate dynamic leveling becomes possible.

[0164] (2) Stop The synthesis unit 216 determines that the vehicle is stationary based on at least one of the vehicle information and sensor information, sets α=0, and calculates the pitch angle θp based on the second pitch angle θa. Since this pitch angle θp corresponds to the static pitch angle θs (vehicle attitude angle), static leveling is performed based on the static pitch angle θs.

[0165] (3) Flat road When driving on a flat road without any bumps or irregularities, high-speed pitching fluctuations are unlikely to occur. Therefore, when driving on a flat road, α is set to approximately 0.1 to 0.5, and the weighting of the acceleration sensor is increased to calculate the pitch angle θp.

[0166] (4) Passing over small bumps and uneven surfaces The frequency of vibrations caused by uneven surfaces such as gravel is even higher than 5Hz, for example, it can be 10-20Hz. When driving over small bumps, it is possible that the correct pitch angle θj cannot be calculated by integrating the output of the gyro sensor, and that the leveling control may not be able to keep up. Alternatively, even if the pitch angle based on the integration of the gyro sensor output is accurate, leveling control that follows it may actually cause more trouble. Therefore, when driving over small bumps, the pitch angle θp is calculated by setting α to around 0.1-0.5 and increasing the weighting of the acceleration sensor. This allows for control based on the average that excludes frequencies higher than 5Hz, treating them as noise, and thus reducing trouble.

[0167] (5) The start of a slope (start of going uphill, start of going downhill) At the start of the slope, α can be set to 0.5 to 1.0. In this case, since a steep change in pitch angle is expected, increasing α and making the gyro sensor's influence dominant enables high-speed dynamic leveling.

[0168] (6) The end of the slope (end of the uphill, end of the downhill) At the end of the slope, α can be set to 0.5 to 1.0. In this case, since a steep change in pitch angle is expected, increasing α and making the gyro sensor's influence dominant enables high-speed dynamic leveling.

[0169] (7) Halfway up the hill Since the pitch angle θp is considered to be stable on a slope, it is appropriate to set α = 0.1 to 0.5.

[0170] (8) Sudden acceleration / sudden deceleration In the case of rapid acceleration and deceleration, α can be set to 0.5 to 1.0. In this case, since rapid fluctuations in the pitch angle θp may occur, the weighting of the gyro sensor can be increased, enabling dynamic leveling that responds to dynamic pitch angle fluctuations.

[0171] The operation of the lighting system 100 according to Embodiment 2 is as described in the description of the lighting system 100 according to Embodiment 1. According to the lighting system 100 according to Embodiment 2, the combination of the first sensor 120 and the second sensor 122 makes it possible to distinguish and detect static changes in the vehicle's posture (static changes in pitch angle) due to the number of passengers, the weight of luggage, the weight of fuel, etc., and steep fluctuations in pitch angle due to the inclination of the road surface being traveled on and the unevenness and undulations present on the road surface. Then, by controlling the light distribution according to the nature of the detected pitch angle, glare associated with steep vehicle vibrations during driving can be suppressed.

[0172] (Modification 2) A modified example related to Embodiment 2 will be described.

[0173] (Example 2.1) The second sensor 122 may use a vehicle height sensor instead of an acceleration sensor. The vehicle height sensor may be a rear vehicle height sensor only, or a hybrid of a rear vehicle height sensor and a front vehicle height sensor.

[0174] (Modified version 2.2) 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.

[0175] (Modified version 2.3) The method by which the controller 200 shifts the position of the cutoff line CL vertically is not limited to that described in the embodiment. For example, the light-emitting element array 112 may have a pixel shift function. In this case, the light-emitting element array 112 is provided with reference image data and a pixel shift amount Δy.

[0176] (Modified example 2.4) Control of the optical axis, i.e., control of the cutoff line height, is not limited to pixel control of the high-definition lamp unit 110 (electronic leveling). For example, a normal low-beam unit may be configured to be controllable by a high-speed leveling actuator, and the height of the cutoff line may be controlled by changing the tilt of the low-beam unit (called mechanical leveling). Alternatively, the position of the light-emitting element array 112 may be configured to be mechanically shiftable.

[0177] Alternatively, a combination of electronic and mechanical leveling may be used. In this case, electronic leveling may be applied to steep pitch angle fluctuations, while mechanical leveling may be applied to gradual or static pitch angle changes.

[0178] (Modified example 2.5) In the embodiment, a control method was described in which the optical axis is actively directed upward when the vehicle body tilts forward (nose dive) while the vehicle is in motion, but the application of this disclosure is not limited to that. The upward direction control is limited to static leveling, and in dynamic leveling, only downward direction control may be performed without controlling the optical axis to direct it upward.

[0179] Alternatively, the control to point the optical axis upward may be limited to static leveling and slow dynamic leveling, while for high-speed dynamic leveling, only downward control may be performed instead of upward control.

[0180] (Layout) Figure 18 shows an example of the design of a vehicle 500A equipped with a lighting system 100. As described in Embodiment 2, the lighting system 100 comprises a high-definition lamp unit 110, a controller 200, a first sensor 120, and a second sensor 122.

[0181] The high-definition lamp unit 110 is built into the headlamp 510A. Meanwhile, the first sensor 120, which is a gyro sensor, and the second sensor 122, which includes an acceleration sensor or a vehicle height sensor, are installed inside the passenger compartment 504.

[0182] As shown in Figure 3, the controller 200 includes a pitch angle calculation unit 210 and a cutoff line control unit 220. The pitch angle calculation unit 210 and the cutoff line control unit 220 are implemented on the headlamp 510A side as the same hardware (arithmetic processing unit). Specifically, the pitch angle calculation unit 210 and the cutoff line control unit 220 are implemented on the headlamp 510A side, that is, in a second arithmetic processing unit 542 located outside the passenger compartment 504 (inside the engine room). The second arithmetic processing unit 542 may be part of a unit called a control module 540. In addition to the second arithmetic processing unit 542, the control module 540 may include a power supply circuit that supplies power to the high-definition lamp unit 110. The first arithmetic processing unit 532 and the second arithmetic processing unit 542 may be microcontrollers including a software-controllable CPU.

[0183] The first sensor 120 and the first processing unit 532 are unitized and referred to as the leveling ECU 530. If the second sensor 122 is an accelerometer, the second sensor 122 can also be built into the leveling ECU 530. The first sensor 120 and the second sensor 122 may be a 6-axis sensor 124 that integrates a gyroscope and an accelerometer.

[0184] The first processing unit 532 located inside the vehicle compartment 504 and the second processing unit 542 located outside the vehicle compartment 504 are connected via a vehicle bus 550 such as CAN, or other interfaces.

[0185] In the design shown in Figure 18, the first arithmetic processing unit 532 directly supplies the angular velocity signal based on the first detection signal S1 generated by the first sensor 120 to the second arithmetic processing unit 542. In other words, the second arithmetic processing unit 542 functions as an interface for the vehicle bus 550.

[0186] The second processing unit 542 integrates the angular velocity signal, converts it into pitch angle information (first pitch angle θj), and controls the high-definition lamp unit 110 based on the first pitch angle θj.

[0187] The above is an example of the design of lighting system 100. The advantages of this design will now be explained.

[0188] The headlamp 510A is relatively easy to attach and detach from the vehicle body 502 compared to other parts of the automobile, and some degree of error is expected in the positional relationship between the headlamp 510A and the vehicle body 502. In this configuration, where the first sensor 120, which is a gyro sensor, is built into the headlamp 510A or attached externally to the headlamp 510A, the accuracy of detecting the variation in pitch angle θ will decrease depending on the precision of the assembly of the headlamp 510A to the vehicle body 502. Some form of calibration is necessary to improve the detection accuracy.

[0189] Furthermore, the engine compartment where the 510A headlamp is located is a harsh environment and is susceptible to temperature and humidity changes. If the gyro sensor is placed on the headlamp side, i.e., inside the engine compartment, the output of the gyro sensor may be affected by the environment, potentially reducing the accuracy of detecting pitch angle fluctuations.

[0190] In the configuration shown in Figure 18, the first sensor 120, which is a gyro sensor, is separated from the headlamp 510A and placed inside the passenger compartment 504. This reduces the positional error between the vehicle body 502 and the gyro sensor, and also suppresses temperature fluctuations of the gyro sensor. As a result, the detection accuracy of pitch angle fluctuations can be improved.

[0191] Figure 19 shows another example of the design of vehicle 500B equipped with lighting system 100.

[0192] In this example, the pitch angle calculation unit 210 and the cutoff line control unit 220 are implemented as separate arithmetic processing units. Specifically, the pitch angle calculation unit 210 is implemented in the first arithmetic processing unit 532 in the vehicle compartment 504, and the cutoff line control unit 220 is implemented in the second arithmetic processing unit 542 on the headlamp 510B side.

[0193] The cutoff-line control unit 220 of the first arithmetic processing unit 532 integrates the angular velocity signal output from the first sensor 120 to calculate the first pitch angle θj. The cutoff-line control unit 220 also calculates the second pitch angle θa based on the output of the second sensor 122. The first arithmetic processing unit 532 transmits pitch angle information θ based on the first pitch angle θj and the second pitch angle θa to the second arithmetic processing unit 542. The pitch angle information θ may include both the first pitch angle θj and the second pitch angle θa, or it may be information obtained by combining the first pitch angle θj and the second pitch angle θa.

[0194] The second arithmetic processing unit 542, which corresponds to the cutoff line control unit 220, controls the high-definition lamp unit 110 based on the pitch angle information θ.

[0195] According to the design in Figure 19, similar to the design in Figure 18, by separating the first sensor 120, which is a gyro sensor, from the headlamp 510B and placing it inside the passenger compartment 504, the error in the positional relationship between the vehicle body 502 and the gyro sensor can be reduced, and temperature fluctuations of the gyro sensor can be suppressed. This improves the accuracy of detecting changes in pitch angle.

[0196] The design in Figure 19 has the following advantages compared to the design in Figure 18. The potential problems that may arise with the design in Figure 18 are explained below.

[0197] Figure 20 illustrates the signal transmission and processing in the design shown in Figure 18. The angular velocity signal ωp, which is the output of the gyro sensor, is generated at a predetermined sampling rate (for example, 1 kHz, i.e., a 1 ms period). Therefore, the amount of data in the angular velocity signal ωp is large, and a transmission delay τ occurs when it is transmitted from the first arithmetic processing unit 532 to the second arithmetic processing unit 542 via the vehicle bus 550.

[0198] The second processing unit 542 receives the delayed angular velocity signal ωp' via the vehicle bus 550. It then integrates the angular velocity signal ωp' to convert it into the first pitch angle θj. Ignoring the processing delay, the first pitch angle θj will be delayed by time τ relative to the original angular velocity signal ωp. In other words, the transmission delay τ in the vehicle bus 550 limits the response speed of the lighting system 100. To increase the response speed, it is difficult to use conventional CAN, and it is necessary to use the vehicle bus 550, which has a small transmission delay τ, thus increasing costs.

[0199] To reduce the transmission delay τ, one can reduce the amount of data transmitted, and measures such as downsampling the angular velocity signal ωp can be taken. However, in this case, the error in the pitch angle θj obtained by integrating the angular velocity signal ωp will increase. In other words, the accuracy of the leveling control will decrease.

[0200] Figure 21 illustrates the signal transmission and processing in the design of Figure 19. In the design of Figure 19, the first arithmetic processing unit 532 inside the vehicle cabin integrates the angular velocity signal ωp and converts it into a first pitch angle θj. Therefore, at this stage, there is no effect from transmission delay, and if calculation delay is ignored, the first pitch angle θj can be calculated in virtually real time or with very little delay. The first arithmetic processing unit 532 transmits the first pitch angle θj', based on the first pitch angle θj, to the second arithmetic processing unit 542 via the vehicle bus 550.

[0201] The speed at which the second arithmetic processing unit 542 updates the light distribution of the high-definition lamp unit 110 (update rate) can be around several tens of Hz to 100 Hz (for example, 60 fps, 16.6 ms period). In other words, the first pitch angle θj only needs to be supplied to the second arithmetic processing unit 542 at a rate of several tens of Hz to 100 Hz (for example, 60 fps, 16.6 ms period). To put it another way, the first arithmetic processing unit 532 does not need to send all the samples of the calculated first pitch angle θj to the second arithmetic processing unit 542, but only needs to send the downsampled first pitch angle θj' to the second arithmetic processing unit 542. In this case, the number of samples to be transmitted via the vehicle bus 550, i.e., the amount of data, can be reduced compared to the design in Figure 18. This makes it possible to shorten the transmission delay in the vehicle bus 550. In other words, the design in Figure 19 can employ a vehicle bus 550 with a slower transmission speed compared to the design in Figure 18.

[0202] (Prediction of pitch angle variation) In the design shown in Figure 19, the effect of the transmission delay τ is greater as the frequency of the pitch angle fluctuation increases, that is, as the period of the vibration shortens. Therefore, the effect of propagation delay can be ignored at around 1 Hz, but for high-frequency vibrations (e.g., 2-5 Hz), response delay may become a problem. Below, we will describe techniques for further improving the response speed of the lighting system 100.

[0203] The first processing unit 532 generates a future predicted value θj^ of the first pitch angle θj based on the output of the first sensor 120. When the transmission delay τ in the vehicle bus 550 is τ, the predicted value θj^ is equal to the current time t i A time (t) that is further ahead τ i It is preferable that the predicted value is from +τ onwards. The method for predicting the first pitch angle θj is not particularly limited.

[0204] For example, the first arithmetic processing unit 532 may use FFT (Fast Fourier Transform) to predict the first pitch angle θj. Figure 22 illustrates the prediction of the first pitch angle θj based on FFT. The upper part of Figure 22 shows an example of the time waveform of the first pitch angle θj.

[0205] The first processing unit 532 converts the time waveform of the first pitch angle θj up to the present into spectral information in the frequency domain. The lower part of Figure 22 shows the spectra of the first pitch angle θj obtained in three states. More specifically, (i) stationary state, (ii) when pitching occurs while driving. The spectrum of three states is: (iii) not in operation, (iii) pitching occurring while driving. (ii) The state in which pitching does not occur corresponds to the state when driving on a flat road without bumps or unevenness in the road surface, and is a situation in which optical axis correction is not required. (iii) Pitching occurs The condition is when driving over bumps or uneven road surfaces, corresponding to a situation where optical axis correction is necessary. As shown in (ii), even when driving on a flat road surface, the spectrum contains several frequency components. As shown in (iii), when pitching occurs, the same as in (ii) Compared to the spectrum, certain frequency components become larger. In the example in Figure 22, 0.84 Hz, 1.39 Hz, and 1.83 Hz can be estimated as pitching requiring optical axis correction. The first processing unit 532 can generate a future predicted value θj^ in the time domain of the first pitch angle θj from the specific frequency components.

[0206] To generate future predicted values ​​θj^ for the first pitch angle θj, a time-series prediction algorithm for waveform data using deep learning can also be employed.

[0207] The second arithmetic processing unit 542 performs leveling control based on the currently measured first pitch angle θj and the predicted value of the future first pitch angle θj^. The second arithmetic processing unit 542 combines the two pitch angles θj and θj^ (for example, by weighted addition) to obtain the pitch angle θj * Generates a pitch angle θj * Leveling control may be performed based on this.

[0208] The second arithmetic processing unit 542 normally performs leveling control based on the actually measured first pitch angle θj, and may also reflect the predicted value θj^ in the leveling control when the predicted value θj^ is large.

[0209] Since the predicted value θj^ is not always accurate, performing leveling correction based on an incorrect negative predicted value θj^ may cause glare because the optical axis will be corrected upwards. Therefore, the second arithmetic processing unit 542 may reflect the positive (nose-up) predicted value θj^ in the leveling control, and not reflect the negative (nose-dive) predicted value θj^ in the leveling control, or may relatively reduce the proportion of its contribution to the leveling control compared to the positive case.

[0210] The first arithmetic processing unit 532 may generate an index representing the accuracy of the predicted value θj^ when generating the predicted value θj^. In this case, the second arithmetic processing unit 542 may perform leveling control based on the predicted value θj^ if the accuracy is high, and ignore the predicted value θj^ if the accuracy is low.

[0211] In this way, by utilizing the predicted value θj^ of the first pitch angle, the effects of transmission delay and signal processing delay can be recovered and reduced, enabling faster tracking of pitch angle fluctuations.

[0212] A variation in the layout will be explained. In the configuration shown in Figure 18, the first sensor 120, which is a gyro sensor, is separated from the headlamp 510A and placed inside the passenger compartment 504. However, the position of the gyro sensor is not limited to the passenger compartment 504. For example, the first sensor 120, which is a gyro sensor, may be placed in a position independent of the headlamp 510A in the engine compartment. This reduces the error in the positional relationship between the vehicle body 502 and the gyro sensor.

[0213] (Structure of headlamps) Figure 23 shows an example of the structure of a headlamp 510. The headlamp 510 comprises a lamp body 512, a lens 514, a connector 516, a high-definition lamp unit 110, a control module 540, a lighting ECU 560, a leveling actuator 562, a turn signal lamp 564, a clearance lamp 566, and a lamp bracket 568.

[0214] The headlamp 510 is connected to the vehicle via a cable connected to connector 516. The cable includes transmission lines for the power signal IG, global CAN signal, local CAN signal, low beam indicator signal Lo, and turn signal TURN (collectively referred to as control signals).

[0215] The lighting ECU 560 controls the on / off state and light distribution of the high-definition lamp unit 110 based on control signals from the vehicle body. The lighting ECU 560 also controls the on / off state of the turn signals 564 and clearance lamps 566.

[0216] The control module 540 is a unit that controls the high-definition lamp unit 110 and includes a controller 200 and a constant voltage converter 544. The controller 200 receives the pitch angle information described above via the CAN interface of the luminaire ECU 560. The portion of the controller 200 corresponding to the pitch angle calculation unit 210 may be implemented in the luminaire ECU 560.

[0217] The high-definition lamp unit 110 is supported by a lamp bracket 568. The lamp bracket 568 is tiltable in the pitching direction. A leveling actuator 562 can position the lamp bracket 568 in the pitching direction. The leveling actuator 562 can be used for adjusting (aiming) the optical axis of the high-definition lamp unit 110.

[0218] Figure 24 shows yet another example of the design of a vehicle 500C equipped with a lighting system 100. As mentioned above, if the first sensor 120, which is a gyro sensor, is placed inside the vehicle, information related to high-speed pitch angle fluctuations must be transmitted via the vehicle bus 550, and the responsiveness of the lighting system 100 is limited by the transmission delay.

[0219] In the example shown in Figure 24, the first sensor 120, which is a gyro sensor, is located in the engine compartment outside the passenger compartment. More specifically, the first sensor 120 is located in the headlamp 510C. In other words, the first sensor 120 is one of the components of the headlamp 510C and may be built into the headlamp 510C or attached to the headlamp 510C externally.

[0220] In this example, the controller 200, which includes a pitch angle calculation unit 210 and a cutoff line control unit 220, is also built into the headlamp 510.

[0221] The connection between the controller 200 and the first sensor 120 does not require a vehicle bus such as CAN, and a faster, lower-latency interface can be used. The type of interface is not particularly limited, and a known serial interface or parallel interface can be used. For example, as a serial interface, SPI (Serial Peripheral Interface) or I 2 You may also use C, etc.

[0222] Furthermore, since the output of the second sensor 122 is primarily used for detecting a static pitch angle θs with a low frequency bandwidth, transmission delay is less likely to be a problem. Therefore, the second sensor 122 is located outside the vehicle cabin. The conversion from the output of the second sensor 122 to the second pitch angle θa may be performed in the second arithmetic processing unit 542, which includes a pitch angle calculation unit 210. In this case, the first arithmetic processing unit 532 operates as an interface circuit for the vehicle bus 550.

[0223] Alternatively, the conversion from the output of the second sensor 122 to the second pitch angle θa may be performed in the first arithmetic processing unit 532.

[0224] According to the design in Figure 24, by placing the gyro sensor on the headlamp side, it becomes possible to use a high-speed serial or parallel interface without using the vehicle bus, significantly reducing transmission delay and improving leveling responsiveness.

[0225] Figure 25 shows an example of the structure of headlamp 510C. The basic configuration of headlamp 510C is the same as that of headlamp 510 in Figure 23.

[0226] In this configuration, the first sensor 120, which is a gyro sensor, is fixed to the lamp body 512. By directly fixing the gyro sensor to the lamp body, which has the highest rigidity, the detection accuracy of the gyro sensor can be improved. As mentioned above, the connection between the first sensor 120 and the controller 200 is not via a CAN interface, but via a serial or parallel local transmission line. The transmission of signals from the first sensor 120 to the controller 200 may or may not be via the lighting ECU 560.

[0227] More preferably, the gyro sensor is fixed to the bottom surface of the lamp body 512. The temperature distribution inside the lamp body tends to be higher at the top and lower at the bottom. Therefore, by fixing the gyro sensor to the bottom surface where the temperature is relatively lower, the thermal effects on the gyro sensor can be reduced.

[0228] In the configuration shown in Figure 25, the first sensor 120 is located on the outside of the bottom surface of the lamp body. The temperature tends to be lower on the outside of the lamp body 512 than on the inside. Therefore, by placing the gyro sensor on the outside of the lamp body, the thermal effects on the gyro sensor can be reduced.

[0229] Figure 26 shows another example of the structure of the headlamp 510C. The basic configuration of the headlamp 510C in Figure 26 is the same as that of the headlamp 510C in Figure 25, with the first sensor 120, which is a gyro sensor, located on the bottom side of the lamp body 512. The difference from Figure 25 is that the first sensor 120 is located inside the lamp body 512. This arrangement is less advantageous from a thermal standpoint compared to Figure 25, but it makes it possible to integrate the first sensor 120 together with the lighting ECU 560. This simplifies the structure of the headlamp 510C.

[0230] Figure 27 shows another example of the structure of the headlamp 510C. In the headlamp 510C of Figure 27, the first sensor 120, which is a gyro sensor, is incorporated into the control module 540. Preferably, the controller 200 and the first sensor 120 are mounted on the same control board.

[0231] Although this configuration is less advantageous from a thermal standpoint compared to Figure 25, it allows for a direct connection between the gyro sensor and the controller 200, simplifying the structure and reducing costs. It is also advantageous in terms of transmission speed.

[0232] (modified version) The embodiments described above are illustrative, and it will be understood by those skilled in the art that various modifications are possible in combinations of their components and processing steps. Such modifications will be described below.

[0233] (Variation 1) The second sensor 122 may use a vehicle height sensor instead of an acceleration sensor. The vehicle height sensor may be a rear vehicle height sensor only, or a hybrid of a rear vehicle height sensor and a front vehicle height sensor.

[0234] (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.

[0235] (Variation 3) The method by which the controller 200 shifts the position of the cutoff line CL vertically is not limited to that described in the embodiment. For example, the light-emitting element array 112 may have a pixel shift function. In this case, the light-emitting element array 112 is provided with reference image data and a pixel shift amount Δy.

[0236] (Modification 4) Control of the optical axis, i.e., control of the cutoff line height, is not limited to pixel control of the high-definition lamp unit 110 (electronic leveling). For example, a normal low-beam unit may be configured to be controllable by a high-speed leveling actuator, and the height of the cutoff line may be controlled by changing the tilt of the low-beam unit (called mechanical leveling). Alternatively, the position of the light-emitting element array 112 may be configured to be mechanically shiftable.

[0237] Alternatively, a combination of electronic and mechanical leveling may be used. In this case, electronic leveling may be applied to steep pitch angle fluctuations, while mechanical leveling may be applied to gradual or static pitch angle changes.

[0238] (Variation 5) In the embodiment, the control for actively directing the optical axis upward when the vehicle body pitches forward (nose dive) during vehicle travel has been described, but the application of the present disclosure is not limited thereto. The control for directing upward may be limited to static leveling, and in dynamic leveling, only the control for directing the optical axis downward may be performed without performing the control for directing the optical axis upward.

[0239] Alternatively, the control for directing the optical axis upward may be limited to static leveling and low-speed dynamic leveling, and in high-speed dynamic leveling, only the control for directing the optical axis downward may be performed without performing the control for directing the optical axis upward.

[0240] (Hybrid Leveling Control) Figure 28 is a block diagram of a lamp system 100D compatible with hybrid leveling control. The lamp system 100D includes a high-definition lamp unit 110, a first sensor 120, a second sensor 122, a controller 200D, a leveling actuator 130, and a lamp bracket 140.

[0241] The high-definition lamp unit 110 is supported by the lamp bracket 140. The lamp bracket 140 is capable of tilting in the pitching direction. The leveling actuator 130 positions the lamp bracket 140 in the pitching direction in response to control by the controller 200D, and sets the emission direction θ of the emitted light from the high-definition lamp unit 110 OU T is varied.

[0242] The high-definition lamp unit 110 includes a light-emitting element array 112 and an irradiation optical system 114. The high-definition lamp unit 110 is configured to be capable of controlling light distribution by controlling the on and off states of the plurality of pixels PIX of the light-emitting element array 112.

[0243] The controller 200D detects the pitch angle θp (θa, θj) based on the outputs of the first sensor 120 and the second sensor 122, and controls the light-emitting element array 112 and the leveling actuator 130 based on the pitch angle θp to control the height of the cutoff line of the light distribution pattern PTN. Leveling control by the light-emitting element array 112 is called electronic leveling, and leveling control by the leveling actuator 130 is called mechanical leveling. In other words, the lighting system 100D is a hybrid of electronic leveling and mechanical leveling. Note that in hybrid leveling control (also simply called hybrid control), the method of detecting the pitch angle θp is not limited to the combination of the first sensor 120 and the second sensor 122.

[0244] Figure 29 illustrates a hybrid control system combining electronic and mechanical leveling. The left side of Figure 29 shows the state of the light-emitting element array 112, i.e., image data, while the right side shows the light distribution pattern PTN on the virtual vertical screen 2.

[0245] The controller 200D shifts the position of the boundary 116 between on-pixels and off-pixels in the image data vertically by Δy, the number of pixels controlled by the electronic leveling mechanism. Due to the electronic leveling, the cutoff line CL of the light distribution pattern PTN on the virtual vertical screen 2 moves vertically by a height ΔV corresponding to Δy.

[0246] In the case of electronic leveling control only, the reference position y0 is changed according to the static pitch angle θs. In contrast, in hybrid control, the reference position y0 of the boundary 116 is constant regardless of the static pitch angle θs, and instead of changing y0, the leveling actuator 130 is controlled to control the direction θ of the emitted light from the high-definition lamp unit 110. OUT The entire light distribution pattern PTN on the virtual vertical screen 2 is changed by mechanical leveling, θ OUT It moves vertically by a height ΔH corresponding to the amount of change.

[0247] The above describes the hybrid control using controller 200D. Electronic leveling offers high responsiveness to rapid pitch angle fluctuations. On the other hand, mechanical leveling is inferior to electronic leveling in terms of speed, but it allows for a wider control range of the optical axis (cutoff line height).

[0248] Hybrid control allows for control that would be difficult with electronic or mechanical leveling alone, by combining two leveling control systems with different characteristics.

[0249] Figure 30 is a block diagram showing an example configuration of the controller 200D of the lighting system 100D. The controller 200D includes a pitch angle calculation unit 210 and a cutoff line control unit 220D. The cutoff line control unit 220D includes a correction amount calculation unit 222, and correction units 224 and 226. The correction amount calculation unit 222 calculates the control amount Ae for electronic leveling and the control amount Am for mechanical leveling based on the pitch angles θj and θa. The correction unit 224 generates image data to be supplied to the high-definition lamp unit 110 based on the control amount Ae. The correction unit 226 generates a drive signal to the leveling actuator 130 based on the control amount Am.

[0250] The following describes a specific example of hybrid control.

[0251] (First control example) In the first control example, the static component (static pitch angle) θs is assigned to mechanical leveling, and the dynamic component (dynamic pitch angle) θd is assigned to electronic leveling. That is, the controller 200D controls the leveling actuator 130 according to the static component (static pitch angle) θs of the vehicle body pitch angle θp, and controls the light-emitting element array 112 of the high-definition lamp unit 110 according to the dynamic component (dynamic pitch angle) θd of the vehicle body pitch angle θp.

[0252] (Second control example) In the second control example, the static component (static pitch angle) θs and the low-frequency component of the dynamic component (dynamic pitch angle) θd are assigned to mechanical leveling, while the high-frequency component of the dynamic component (dynamic pitch angle) θd is assigned to electronic leveling. In other words, when considering the pitch angle θp as a whole, components below a predetermined frequency are assigned to mechanical leveling, and components above a predetermined frequency are assigned to electronic leveling.

[0253] (Third control example) In the third control example, the pitch angle θa based on the output of the second sensor 122 is assigned to mechanical leveling, and the pitch angle θj detected based on the output of the first sensor 120 (gyro sensor) is assigned to electronic leveling.

[0254] (Fourth control example) In the fourth control example, mechanical and electronic leveling are used depending on the amplitude of the pitch angle vibration. That is, mechanical leveling is used when the amplitude is large, and electronic leveling is used when the amplitude is small.

[0255] Figure 31 is a block diagram of the luminaire system 100E that supports hybrid leveling control. In addition to the luminaire system 100D shown in Figure 28, the luminaire system 100E includes a fixed light distribution lamp unit 150.

[0256] The fixed-beam lamp unit 150 emits light with a fixed beam pattern forward of the vehicle. The beam pattern PTN on the virtual vertical screen 2 includes a variable pattern PTNv formed by the light from the fixed-beam lamp unit 150 and a fixed pattern PTNf formed by the light from the high-definition lamp unit 110.

[0257] The fixed light distribution lamp unit 150 is configured to illuminate the lower region of the low beam illumination range with light, and the high-definition lamp unit 110 is configured to illuminate the upper region of the low beam illumination range, including the cutoff line, with light.

[0258] A beam serving both as a high beam and a low beam may be configured by the high-definition lamp unit 110 and the fixed light distribution lamp unit 150. That is, the high-definition lamp unit 110 is used to control the cut-off line of the low beam, and is also used as an ADB (Adaptive Driving Beam) for the high beam. In this case, the high-definition lamp unit 110 is configured to illuminate the low In addition to the upper region including the cut-off line in the illumination range of the low beam, it is configured to illuminate the illumination range of the high beam.

[0259] Figures 32(a) and (b) are diagrams for explaining the light distribution control by the lamp system 100E of Figure 31. Figure 32(a) shows the light distribution control of the low beam. The entire light distribution pattern is shifted up and down by ΔH via mechanical leveling. Further, the cut-off line CL of the variable light distribution pattern PTNf within the illumination range of the high-definition lamp unit 110 is shifted up and down by ΔV via electronic leveling.

[0260] Figure 32(b) shows the light distribution control of the high beam. When no oncoming vehicle or preceding vehicle is present in front of the vehicle, all pixels (or most of the pixels) of the light-emitting element array 112 are lit, forming the high beam light distribution. When an oncoming vehicle or a preceding vehicle is detected in front of the vehicle, the corresponding pixels of the light-emitting element array 112 are turned off to set that portion as a light-shielding region OFF. Note that during the high beam operation, the electronic leveling may be disabled, and only the mechanical leveling may be performed.

[0261] Figure 33 is a diagram showing an example of the structure of the lamp system 100E of Figure 31. In addition to the configuration of Figure 19, the lamp system 100E includes a fixed light distribution lamp unit 150. Note that the position of the first sensor 120 is not limited, and it may be provided on the vehicle body side.

[0262] The correction unit 226 in Figure 30 may be implemented as a controller (or driver) of the leveling actuator (1) included in the lamp ECU 560. Further, the part corresponding to the pitch angle calculation unit 210 in the controller 200D may also be implemented in the lamp ECU 560.

[0263] Figure 34 is a perspective view of the luminaire system 100E shown in Figure 31. The high-definition lamp unit 110 and the fixed-distribution lamp unit 150 are mounted on a common lamp bracket 140. The lamp bracket 140 is mounted to the lamp body so as to be rotatable in the pitching direction, by a movable part (not shown). The control module 540 and the luminaire ECU 560 are located on the bottom side of the luminaire system 100E.

[0264] (modified version) The embodiments described above are illustrative, and it will be understood by those skilled in the art that various modifications are possible in combinations of their components and processing steps. Such modifications will be described below.

[0265] (Variation 1) The second sensor 122 may use a vehicle height sensor instead of an acceleration sensor. The vehicle height sensor may be a rear vehicle height sensor only, or a hybrid of a rear vehicle height sensor and a front vehicle height sensor.

[0266] (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.

[0267] (Variation 3) The method by which the controller 200 shifts the position of the cutoff line CL vertically is not limited to that described in the embodiment. For example, the light-emitting element array 112 may have a pixel shift function. In this case, the light-emitting element array 112 is provided with reference image data and a pixel shift amount Δy.

[0268] (Modification 4) Control of the optical axis, i.e., control of the cutoff line height, is not limited to pixel control of the high-definition lamp unit 110 (electronic leveling). For example, a normal low-beam unit may be configured to be controllable by a high-speed leveling actuator, and the height of the cutoff line may be controlled by changing the tilt of the low-beam unit (called mechanical leveling). Alternatively, the position of the light-emitting element array 112 may be configured to be mechanically shiftable.

[0269] Alternatively, a combination of electronic and mechanical leveling may be used. In this case, electronic leveling may be applied to steep pitch angle fluctuations, while mechanical leveling may be applied to gradual or static pitch angle changes.

[0270] (Variation 5) In the embodiment, a control method was described in which the optical axis is actively directed upward when the vehicle body tilts forward (nose dive) while the vehicle is in motion, but the application of this disclosure is not limited to that. The upward direction control is limited to static leveling, and in dynamic leveling, only downward direction control may be performed without controlling the optical axis to direct it upward.

[0271] Alternatively, the control to point the optical axis upward may be limited to static leveling and slow dynamic leveling, while for high-speed dynamic leveling, only downward control may be performed instead of upward control.

[0272] 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]

[0273] This disclosure relates to vehicle lighting equipment. [Explanation of symbols]

[0274] 100...Lighting system, 110...Variable light distribution lamp unit, 112...Light-emitting element array, 114...Irradiation optical system, PIX...Pixel, 120...First sensor, 122...Second sensor, 130...Leveling actuator, 140...Lamp bracket, 150...Fixed light distribution lamp unit, 200...Controller, 210...Pitch angle calculation unit, 212...Integrator, 214...Acceleration direction calculation unit, 216...Combination unit, 218...Driving condition determination unit, 220...Cut-off line control unit, 222...Correction amount calculation unit, 22 4...Correction unit, 500...Vehicle, 502...Vehicle body, 504...Passport compartment, 510...Headlamp, 504...Passport compartment, 530...Leveling ECU, 532...First calculation processing unit, 540...Control module, 542...Second calculation processing unit, 544...Constant voltage converter, 550...Vehicle bus, 560...Lighting ECU, 562...Leveling actuator, 564...Turn lamp, 566...Clearance lamp, 568...Lamp bracket, 2...Virtual vertical screen, S1...First detection signal, S2...Second detection signal.

Claims

1. A variable-beam lamp that includes multiple individually controllable pixels and emits light having a light distribution corresponding to the state of the multiple pixels, A leveling actuator capable of controlling the mechanical position of the variable-light distribution lamp, A controller that controls the leveling actuator and the variable light distribution lamp according to the pitch angle of the vehicle body, Equipped with, The lighting system is characterized in that the controller controls the leveling actuator according to the static component of the pitch angle of the vehicle body, and controls the variable light distribution lamp according to the dynamic component of the pitch angle of the vehicle body.

2. Further equipped with a first sensor including a gyro sensor, The lighting system according to claim 1, characterized in that the controller controls the variable light distribution lamp in accordance with the output of the first sensor.

3. Further comprising a second sensor including a vehicle height sensor or an acceleration sensor, The lighting system according to claim 2, characterized in that the controller controls the leveling actuator in accordance with the output of the second sensor.

4. A fixed-beam lamp that forms a fixed beam pattern, A lamp bracket that supports the fixed-beam lamp and the variable-beam lamp, Furthermore, The lighting system according to any one of claims 1 to 3, characterized in that the leveling actuator can control the position of the lamp bracket.

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