Headlamp control device, headlamp control method, and headlamp system

Abstract

To reduce inconvenience and discomfort experienced by a driver.SOLUTION: A headlamp control device being the device for controlling a headlamp whose light distribution direction can be set in a variable manner, comprises: an occupant monitoring device that detects at least a sight line angle indicating a sight line direction of a driver of the own vehicle and a movement speed of the sight line; and a controller that is connected to the headlamp, the occupant monitoring device, and an imaging device. The controller fixes the light distribution direction without change in a case where the sight line angle belongs to a first range in a first range which is a relatively small angle range in an absolute value from a reference position based on a travel direction of the own vehicle and a second range which is a relatively large angle range, changes the light distribution direction according to the sight line angle when the sight line angle belongs to the second range, and controls the headlamp so as to perform light radiation in the light distribution direction.SELECTED DRAWING: Figure 4

Description

[Technical field]

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

[0002] Japanese Patent Laid-Open Publication No. 06-072234 (Patent Document 1) describes a light distribution control technology that ensures the driver's visibility while driving by estimating the driver's gaze position and controlling at least one of the headlamp illumination direction and illumination range so that light is irradiated at the position estimated to be the gaze position.

[0003] In recent years, driver monitoring systems have become widespread that capture images of the driver's face and analyze the images to extract information such as the direction of the face, the direction of the gaze, and the number of blinks. For example, when the driver has their eyes closed for a long time, or when the direction of the face or the direction of the gaze is far away from the road ahead, the system determines that the driver is dozing off or looking away and issues a warning.

[0004] Here, we consider using information detected by a driver monitoring system to estimate the driver's gaze position and control the headlamp irradiation direction, etc. Generally, the human gaze is constantly moving, so if the headlamp irradiation direction, etc. were simply controlled in conjunction with the movement of the gaze, the irradiation direction, etc. would be changed more frequently than necessary, which could be annoying and uncomfortable for the driver. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 06-072234 Summary of the Invention [Problem to be solved by the invention]

[0006] An object of a specific embodiment of the present disclosure is to provide a light distribution control technique that can reduce annoyance and discomfort felt by a driver. [Means for solving the problem]

[0007] [1] A headlamp control device according to one embodiment of the present disclosure includes: A device for controlling a headlamp that can variably set a light distribution direction, an occupant monitoring device that detects at least a line of sight angle indicating a line of sight direction of a driver of the vehicle and a line of sight movement speed; a controller connected to each of the headlight, the passenger monitoring device, and the imaging device; Including, The controller: a first range being a relatively small angle range in absolute value from a reference position based on a traveling direction of the vehicle, and a second range being a relatively large angle range, when the line of sight angle falls within the first range, the light distribution direction is fixed without being changed, and when the line of sight angle falls within the second range, the light distribution direction is changed to follow the line of sight angle, and the headlight is controlled so as to emit light in the light distribution direction. A headlamp control device. [2] A method for controlling a headlamp according to one aspect of the present disclosure includes: A method for controlling a headlamp whose light distribution direction can be variably set, comprising: Detecting at least a line of sight angle indicating a line of sight direction of a driver of the vehicle and a line of sight movement speed; controlling the headlamp so that, when the line of sight angle falls within a first range, which is a range of angles that are relatively small in absolute value from a reference position based on a traveling direction of the vehicle, and a second range, which is a range of angles that are relatively large in absolute value from a reference position based on a traveling direction of the vehicle, the light distribution direction is fixed without being changed, and when the line of sight angle falls within the second range, the light distribution direction is changed to follow the line of sight angle, and light is emitted in the light distribution direction; A method for controlling a headlamp, comprising: [3] A headlamp system according to one embodiment of the present disclosure includes: The control device according to [1] above; A headlamp connected to the control device and whose operation is controlled by the control device; A headlamp system comprising:

[0008] According to the above configuration, a light distribution control technique is obtained that can reduce the annoyance and discomfort felt by the driver. [Brief description of the drawings]

[0009] [Figure 1] Fig. 1A is a diagram showing a configuration of a headlamp system according to an embodiment, and Fig. 1B is a diagram showing a configuration example of a computer system. [Diagram 2] 2(A) and 2(B) are diagrams for explaining the outline of light distribution control by the headlamp system. [Diagram 3] FIG. 3 is a diagram showing a coordinate system for explaining the relationship between the driver's line of sight and the light irradiation direction of the headlamp unit. [Figure 4] FIG. 4 is a diagram for explaining the contents of the process performed by the first filter setting unit. [Diagram 5] FIG. 5 is a diagram for explaining the contents of the process performed by the second filter setting unit. [Figure 6] FIG. 6 is a graph showing an example of the relationship between the vehicle speed and the coefficient K. [Figure 7] FIG. 7 is a flowchart showing the operation procedure of the headlamp system. [Figure 8] FIG. 8 is a flowchart showing the operation procedure of the headlamp system. [Figure 9] 9(A) to 9(C) are diagrams for explaining light distribution control when the moving range of the line of sight remains in a blind area. [Figure 10] 10(A) to 10(D) are diagrams for explaining light distribution control when the movement range of the line of sight switches from an insensitive area to an eye-linked area. [Figure 11] 11(A) to 11(C) are diagrams for explaining light distribution control when the moving range of the line of sight remains within the line of sight linking area. [Figure 12] 12(A) to 12(D) are diagrams for explaining light distribution control when the movement range of the line of sight switches from the line of sight linked area to the blind area. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] 1(A) is a diagram showing the configuration of a headlamp system according to an embodiment. The illustrated headlamp system includes a controller 1, an imaging device 2, a passenger monitoring device 3, a vehicle speed sensor 4, and a pair of headlamp units 5L and 5R. This headlamp system is for emitting light forward of a vehicle.

[0011] The controller 1 controls the light irradiation state of each of the headlamp units 5L and 5R. The controller 1 can be configured using a computer system such as that shown in Fig. 1(B), that is, a computer system including a processor (CPU: Central Processing Unit) 201, a ROM (Read Only Memory) 202, a RAM (Random Access Memory) 203, a storage device 204 such as a flash memory, an input / output interface 205, etc. The controller 1 of this embodiment is capable of performing each function described below by reading and executing a program 206 stored in advance in the storage device 204 by the processor.

[0012] The controller 1 includes a first filter setting unit 11, a second filter setting unit 12, a light distribution pattern setting unit 13, and a control signal generating unit 14 as functional blocks realized by executing a program.

[0013] The first filter setting unit 11 performs processing such as setting whether to perform gaze linkage or fixed light distribution as light distribution control based on the driver's gaze angle obtained from the passenger monitoring device 3. Details of the processing content by the first filter setting unit 11 will be described later.

[0014] The second filter setting unit 12 performs processes such as calculating the congestion degree, setting a coefficient according to the moving speed of the driver's line of sight, and setting a filter coefficient determined by the congestion degree, the vehicle speed, and the coefficient, based on the information obtained from the imaging device 2. Details of the processing contents by the second filter setting unit 12 will be described later.

[0015] The light distribution pattern setting unit 13 sets a light distribution pattern that determines the state of light emitted by each headlight unit 5L, 5R, based on the situation in front of the vehicle captured by the imaging device 2 and the processing results by the first filter setting unit 11 and the second filter setting unit 12.

[0016] The control signal generating unit 14 generates a control signal for causing each of the headlamp units 5L, 5R to form irradiation light according to the light distribution pattern set by the light distribution pattern setting unit 13, and supplies the control signal to each of the headlamp units 5L, 5R.

[0017] The imaging device 2 detects the positions of vehicles and pedestrians ahead based on an image obtained by photographing the space ahead of the vehicle, and includes a camera 21 and an image processing unit 22. The camera 21 photographs the space ahead of the vehicle and generates image data (image signals). The image processing unit 22 performs image recognition processing on the image data generated by the camera 21, thereby detecting the situation ahead of the vehicle, such as the positions and number of pedestrians, the positions and number of vehicles ahead (preceding vehicles or oncoming vehicles), and white lines on the road.

[0018] The function of the image processing unit 22 may be provided in the controller 1. In that case, image data is supplied from the imaging device 2 to the controller 1, and the controller 1 executes a predetermined program to perform image recognition processing.

[0019] The passenger monitoring device 3 captures images of the faces of the driver and other passengers of the vehicle and analyzes the images to extract information such as the face direction, gaze direction, gaze movement speed, and blink frequency.

[0020] The vehicle speed sensor 4 detects the speed of the host vehicle and outputs a signal or data according to the magnitude of the speed.

[0021] A pair of headlamp units 5L, 5R are mounted at predetermined positions on the left and right sides of the front of the vehicle, and operate in response to control signals provided by the controller 1 to form light to be irradiated ahead of the vehicle. The headlamp units 5L, 5R of this embodiment are capable of forming low beam (passing light) and high beam (driving light) illuminations, and also capable of forming an adaptive driving beam (ADB) that is illumination light that is partially dimmed (or turned off) in a range that is arbitrarily set according to the position of the vehicle ahead, etc.

[0022] Various known configurations can be adopted for each headlamp unit 5L, 5R. For example, a high beam or low beam can be formed by a lamp unit configured by combining a light source bulb with a reflector or a shielding plate. An adaptive driving beam can also be formed by using a lamp unit in which light emitting elements such as LEDs (Light Emitting Diodes) are arranged in one or two directions and the lighting state of each light emitting element can be individually controlled. An adaptive driving beam can also be formed by using a lamp unit that includes a light source and a liquid crystal element and can individually control the light transmission state of each pixel of the liquid crystal element. An adaptive driving beam can also be formed by using a lamp unit that includes a light emitting element such as a laser diode and a scanning element such as a mirror device that scans the light emitted from the light emitting element and can control the timing of turning on and off the light emitting element and the scanning timing by the scanning element. Furthermore, in the lamp units of these configurations, a high beam or low beam may be formed in addition to the adaptive driving beam.

[0023] 2(A) and 2(B) are diagrams for explaining the light distribution control by the headlamp system. As shown in each diagram, the headlamp system of this embodiment irradiates a low beam LB and a high beam HB ahead of the vehicle by the headlamp units 5L and 5R. At this time, the high beam HB may be provided with a dimming range according to the position of a vehicle ahead if there is one ahead. In addition, the headlamp system provides a high illuminance band BR at a position corresponding to the line of sight L of the driver of the vehicle within the irradiation range of the high beam HB. This high illuminance band BR is a portion in which the illuminance is relatively higher than other ranges within the irradiation range of the high beam HB.

[0024] For example, if the line of sight direction L is in the front direction of the vehicle, the high illuminance band BR is provided in the front direction of the vehicle as shown in Fig. 2(A). If the line of sight direction L changes to the right diagonal direction of the vehicle, the high illuminance band BR is provided in the right diagonal direction of the vehicle as shown in Fig. 2(B). Although not shown, the same applies when the line of sight direction L is in the left diagonal direction of the vehicle. In this case, in this embodiment, the high illuminance band BR is not simply made to follow the change in the line of sight direction L, but the irradiation direction of the high illuminance band BR is controlled by a method described in detail below.

[0025] FIG. 3 is a diagram showing a coordinate system for explaining the relationship between the driver's line of sight and the light irradiation direction of the headlight unit. In this coordinate system, the traveling direction of the vehicle is set to 0 deg (0°), and the clockwise angle is set to a positive value. The driver origin S is set to the midpoint of the line segment connecting the driver's left and right eyes. The driver origin S can be specified based on information obtained from the passenger monitoring device 3. The driver's line of sight angle θ is set to the average value of the line of sight angles of the left and right eyes. The line of sight angles of the left and right eyes can be specified based on information obtained from the passenger monitoring device 3. The mutual distance between the headlight units 5L and 5R is W, the mutual distance between the left headlight unit 5L and the driver origin S is l, the mutual distance between the driver origin S and the headlight units 5L and 5R is d, and the mutual distance between the driver's gaze position P and the driver origin S (the distance along the traveling direction of the vehicle) is D. The driver's gaze position P can be detected by the passenger monitoring device 3. The mutual distance D can be calculated based on the positional relationship between the gaze position P and the driver origin S.

[0026] Here, since the driver's position (driver origin S) and the positions of the headlamp units 5L and 5R are different, if the line of sight angle θ is used as the light distribution angle without performing parallax correction, light cannot be accurately irradiated to the driver's gaze position. For this reason, parallax correction is performed as follows. Note that in the following, the light distribution angle before parallax correction is referred to as φ', and the light distribution angle after parallax correction is referred to as φ.

[0027] The light distribution angle after parallax correction to be used for the left headlamp unit 5L is φ LH The light distribution angle after parallax correction to be used for the right headlamp unit 5R is φ RH Then, they can be expressed as follows. Note that in the formulas, the term 180 / π is a term used to convert the angle from radian notation to degree notation.

number

[0028] FIG. 4 is a diagram for explaining the contents of the processing by the first filter setting unit. In the diagram, the traveling direction of the vehicle is defined as 0 deg, and the clockwise direction is defined as a positive value. Thresholds are set in the positive and negative directions of the line of sight. The threshold in the positive direction is +Th1, and the threshold in the negative direction is -Th1. The range from -Th1 to +Th1 is called the blind area (area B in the diagram), and the range of angles below -Th1 and the range of angles above +Th1 are respectively called the gaze linkage areas (areas A in the diagram). These thresholds +Th1 and -Th1 can be said to indicate the positions of the boundaries between the blind area and the gaze linkage area.

[0029] The first filter setting unit 11 sets the pre-parallax light distribution angle φ' to 0 when the driver's line of sight angle θ is in a range greater than -Th1 and less than +Th1 (-Th1<θ<+Th1 range). That is, in this range, the pre-parallax light distribution angle φ' is fixed to 0 regardless of the magnitude of the line of sight angle θ. On the other hand, when the driver's line of sight angle θ is in a range less than -Th1 (θ≦-Th1 range) or in a range greater than +Th1 (θ≧+Th1 range), the light distribution direction is set to follow the movement of the line of sight.

[0030] In this way, when the line of sight is in the forward direction or in a direction close to the forward direction and there is little need to link the light distribution direction to the line of sight, the light distribution is fixed, preventing frequent changes in the light distribution and reducing the annoyance and discomfort felt by the driver. As for the thresholds, it is preferable to set -Th1 to -15deg and +Th1 to +15deg, as an example. In other words, it is preferable to set the threshold to 15deg in absolute value. This is a numerical example based on the effective visual field in which information can be gazed upon and instantly recognized by human eye movement alone. Note that the thresholds may be increased or decreased within a range of, for example, 10deg to 20deg in absolute value.

[0031] In addition, the first filter setting unit 11 sets the angular velocity w of the light irradiation direction when performing the line-of-sight-linked light distribution control and also sets the pre-correction light distribution angle based on the relationship between the line-of-sight angle θ and the pre-correction light distribution angle φ' of the parallax between a certain time (t-1) and the next time (t). This makes the light distribution change natural and reduces the discomfort of the driver.

[0032] Specifically, when the light distribution angle φ' before parallax correction at time (t-1) is 0 and the line-of-sight angle θ at time (t) belongs to the line-of-sight linked area, it can be said that the area is switched from the insensitive area to the line-of-sight linked area. In this case, the first filter setting unit 11 sets the angular velocity w to a predetermined value w1 (w=w1) and sets the light distribution angle φ' before parallax correction to be the same as the line-of-sight angle θ (φ'=θ).

[0033] Also, when the light distribution angle φ' before parallax correction at time (t-1) is not 0 but is a value that belongs to the gaze linked area, and the gaze angle θ at time (t) belongs to the insensitive area, it can be said that the area is switched from the gaze linked area to the insensitive area. In this case, the first filter setting unit 11 sets the angular velocity w to a predetermined value w2 (w=w2) and sets the light distribution angle φ' before parallax correction to 0 (φ'=0).

[0034] Here, the angular velocity w during the movement in the light irradiation direction is preferably set to have a relationship of w1>w2. By setting the angular velocity w1 when switching from the blind area to the line-of-sight linkage area to a larger value, it is possible to improve the tracking ability of pedestrians and obstacles that appear outside the driver's field of vision. As an example, the angular velocity w1 can be set to 100 deg / s based on the speed during impulsive eye movement. In addition, the angular velocity w2 can be set to 35 deg / s based on the maximum speed at which the visual target can be smoothly tracked in the horizontal direction. Note that w1 may be set between 70 and 130 deg / s, for example, and w2 may be set between 25 and 45 deg / s, for example.

[0035] When the angular velocity w is set in this manner, the light distribution pattern setting unit 13 calculates the above-mentioned parallax-corrected light distribution angle φ (φ LHand φ RH , the same below) are calculated, and the light distribution pattern is set so that the light irradiation direction is switched to a direction specified by these light distribution angles. At that time, the light distribution pattern is set by the light distribution pattern setting unit 13 so that the light irradiation direction is changed at a constant angular velocity according to the set angular velocity w1 or w2.

[0036] FIG. 5 is a diagram for explaining the contents of the processing by the second filter setting unit. In general, eye movements are classified into voluntary eye movements and involuntary eye movements. Voluntary eye movements are also classified into saccadic eye movements and pursuit eye movements. Saccadic eye movements can be said to be relatively fast line of sight movements. In contrast, pursuit eye movements can be said to be relatively slow line of sight movements. For this reason, the second filter setting unit 12 sets the coefficient (line of sight coefficient) k to k1 when the line of sight movement speed of the driver is greater than a predetermined threshold Th2, and sets the coefficient k to k2 when the line of sight movement speed is equal to or less than the threshold Th2. k1 is a coefficient corresponding to fast line of sight movement, and k2 is a coefficient corresponding to slow line of sight movement, and are set to satisfy the relationship k1>k2. As an example, k1 can be set to 0.4, and k2 can be set to 0.05. The use of the coefficient k will be described later.

[0037] The threshold value Th2 can be set to 100 deg / s, for example. For example, one type of involuntary eye movement is a microsaccade, which is an involuntary eye movement that occurs when the viewpoint is fixed. Since the speed of the line of sight movement in this microsaccade is 10 to 100 deg / s, by setting the threshold value Th2 to 100 deg / s, it is possible to prevent the involuntary eye movement and pursuit eye movement from being tracked with high responsiveness. This makes it possible to prevent unintended light distribution movements and to track intended line of sight movements at a sufficient speed.

[0038] Furthermore, when the vehicle speed v is 0 based on the vehicle speed obtained by the vehicle speed sensor 4, the second filter setting unit 12 changes the light irradiation direction to 0 at a constant angular velocity of the angular velocity w2 and fixes the irradiation angle at 0. This prevents glare on vehicles and pedestrians ahead, which is caused by the light distribution moving in conjunction with the movement of the line of sight when the vehicle is stopped, and prevents the driver from feeling annoyed.

[0039] The second filter setting unit 12 also calculates the congestion degree u based on information such as the number of vehicles, bicycles, and pedestrians ahead, the road width, and the number of lanes obtained from the imaging device 2. The congestion degree u is a parameter that indicates how many objects that the driver can see are concentrated in the field of view, and can be calculated, for example, as u = (number of vehicles ahead + number of pedestrians) / (number of lanes x road width). Note that the congestion degree u needs to be set to a value equal to or less than the coefficient k to prevent a transient response. As an example, if the number of vehicles ahead is 3, the number of pedestrians is 2, the number of lanes is 2, and the road width (for one lane) is 3.5 m, the congestion degree u is approximately 0.714.

[0040] The second filter setting unit 12 performs the following filter processing on the driver's line of sight angle θ to obtain a pre-correction light distribution angle φ′ at time (t). t θ t is the line of sight angle at time (t), φ' t is the uncorrected light distribution angle at time (t), φ' t-1 is the uncorrected light distribution angle at time (t-1). The coefficient K (filter coefficient) is a coefficient determined according to the congestion degree u, the vehicle speed v, etc., and is set variably within the range of 0 to 1.

number

[0041] Filter processing can remove high frequency components of the line of sight angle θ. Using the filtered value as the light distribution angle can calm the movement of the light distribution and reduce the discomfort that the driver may feel. By setting the coefficient K variably between 0 and 1, the strength of the filter processing can be variably set, and the tracking ability of the light distribution to the line of sight can be changed.

[0042] The coefficient K is set as follows: v is the vehicle speed (km / h), u is the congestion level, and k is the coefficient k1 or k2 described above.

number

[0043] As can be seen from the above formula (4), the coefficient K takes a small value when the congestion level is relatively high, and takes a large value when the congestion level is relatively low. The coefficient K also takes a small value when the vehicle speed is relatively low, and takes a large value when the vehicle speed is relatively high. Furthermore, the coefficient K takes a small value when the coefficient k (line of sight coefficient) is relatively small, and takes a large value when the line of sight coefficient is relatively high.

[0044] By setting the coefficient K as described above, when the vehicle speed v is low, as shown in FIG. 6, K becomes large and the light distribution tracking ability decreases, and when the congestion level u is high, K becomes small and the light distribution tracking ability decreases. Also, when the coefficient k is large, that is, when the line of sight moves vigorously, K becomes large and the light distribution tracking ability decreases. Therefore, in situations where the line of sight moves vigorously, such as when driving on a congested road or when driving at a low speed while checking the surroundings, the light distribution tracking ability decreases, so the discomfort that the driver may feel can be reduced. Also, when driving at a medium speed or a high speed, K becomes large and the light distribution tracking ability increases. Therefore, sufficient tracking ability to the line of sight can be obtained in situations where the driver needs to recognize pedestrians and obstacles in a short time.

[0045] 7 and 8 are flowcharts showing the operation procedure of the headlamp system. Note that the order of the processes shown here can be changed as long as no contradiction or inconsistency occurs in the results of the information processing, and other processes not explicitly shown here can be added.

[0046] The first filter setting unit 11 receives the driver's line of sight angle θ t (Step S11). t If the condition is satisfied (step S12; YES), the first filter setting unit 11 sets the pre-correction light distribution angle φ′ at the immediately previous time (t−1). t-1 If 0 (step S13; YES), the uncorrected light distribution angle φ' at time (t) t is set to 0 (step S14). This corresponds to light distribution control in a blind area. Note that, in the initial processing, the pre-correction light distribution angle φ′ at time (t-1) is t-1 A predetermined value (for example, 0) is used as the

[0047] Pre-correction light distribution angle φ' t is set to 0, the first filter setting unit 11 sets the corrected light distribution angle φ t is fixed to 0 (step S15). In this case, the light distribution pattern setting unit 13 sets the corrected light distribution angle φ t A light distribution pattern including a high illuminance band corresponding to (=0) is set, and a light distribution control signal corresponding to the light distribution pattern is generated by the control signal generating unit 14 and output to each headlamp unit 5L, 5R. Each headlamp unit 5L, 5R emits light so as to realize a light distribution corresponding to the set light distribution pattern. Then, the process returns to step S11, and the subsequent processes are performed.

[0048] On the other hand, in step S13 described above, the pre-correction light distribution angle φ′ at time (t−1) t-1 If not 0 (step S13; NO), the first filter setting unit 11 sets the angular velocity to w2 (step S16), and sets the pre-correction light distribution angle φ′ at time (t) tis set to 0 (step S17). This scene corresponds to the light distribution control when switching from the line-of-sight linked area to the blind area.

[0049] Next, the first filter setting unit 11 calculates the corrected light distribution angle φ t (Step S18). Note that the corrected light distribution angle φ t can be obtained based on the above formulas (1) and (2). In this case, the light distribution pattern setting unit 13 sets the corrected light distribution angle φ t A light distribution pattern is set so that the headlight moves at an angular velocity w2 in a direction specified by, and a light distribution control signal corresponding to the light distribution pattern is generated by the control signal generating unit 14 and output to each headlight unit 5L, 5R. Each headlight unit 5L, 5R emits light so as to realize a light distribution corresponding to the set light distribution pattern. Then, the process returns to step S11, and the subsequent processes are performed.

[0050] On the other hand, in step S12, −Th1<θ t When the condition -Th1<φ' is not satisfied (step S12; NO), the first filter setting unit 11 sets the condition -Th1<φ' t-1 If the condition <+Th1 is satisfied (step S20; YES), the angular velocity is set to w1 (step S21), and the pre-correction light distribution angle φ' at time (t) is t is set to the threshold value +Th1 (or -Th1) (step S22). This scene corresponds to the light distribution control when switching from the blind area to the line-of-sight linkage area.

[0051] Next, the first filter setting unit 11 calculates the corrected light distribution angle φ t (Step S23). Note that the corrected light distribution angle φ t can be obtained based on the above formulas (1) and (2). In this case, the light distribution pattern setting unit 13 sets the corrected light distribution angle φ tA light distribution pattern is set so that the headlight moves at an angular velocity w1 in a direction specified by, and a light distribution control signal corresponding to the light distribution pattern is generated by the control signal generating unit 14 and output to each headlight unit 5L, 5R. Each headlight unit 5L, 5R emits light so as to realize a light distribution corresponding to the set light distribution pattern. Then, the process returns to step S11, and the subsequent processes are performed.

[0052] On the other hand, in step S20, -Th1<φ' t-1 If the condition <+Th1 is not satisfied (step S20; NO), the process proceeds to processing by the second filter setting unit 12 (see FIG. 8). Specifically, if the vehicle speed v is 0 (step S25; YES), the second filter setting unit 12 sets the angular velocity to w2 (step S26) and sets the pre-correction light distribution angle φ′ at time (t) t is set to 0 (step S27). This scene corresponds to the light distribution control while the vehicle is stopped.

[0053] Next, the second filter setting unit 12 calculates the corrected light distribution angle φ t (Step S28). Note that the corrected light distribution angle φ t can be obtained based on the above formulas (1) and (2). In this case, the light distribution pattern setting unit 13 sets the corrected light distribution angle φ t A light distribution pattern is set so that the headlight moves at an angular velocity w2 in a direction specified by, and a light distribution control signal corresponding to the light distribution pattern is generated by the control signal generating unit 14 and output to each headlight unit 5L, 5R. Each headlight unit 5L, 5R emits light so as to realize a light distribution corresponding to the set light distribution pattern. Then, the process returns to step S11, and the subsequent processes are performed.

[0054] On the other hand, when the vehicle speed v is not 0 (step S25; NO), if the line of sight movement speed (eyeball speed) is greater than the threshold Th2 (step S30; YES), the second filter setting unit 12 sets the coefficient k to k1 (step S31), and if the line of sight movement speed is equal to or less than the threshold Th2 (step S31; NO), the second filter setting unit 12 sets the coefficient k to k2 (step S32). This situation corresponds to line of sight-linked light distribution control.

[0055] Next, if the congestion level u is equal to or greater than the coefficient k (k1 or k2) set in step S31 or S32 (step S33; YES), the second filter setting unit 12 calculates the coefficient K using the above equation (4) based on the coefficient k, the congestion level u, and the vehicle speed v (step S35).

[0056] On the other hand, if the congestion degree u is smaller than the coefficient k (step S33; NO), the second filter setting unit 12 replaces the value of the congestion degree u with the coefficient k (step S34), and calculates the coefficient K using the above equation (4) based on the coefficient k, the congestion degree u, and the vehicle speed v (step S35).

[0057] Next, the second filter setting unit 12 calculates the line of sight angle θ t By performing a filter process based on the above formula (3) on t is calculated (step S36).

[0058] Next, the second filter setting unit 12 calculates the corrected light distribution angle φ t (Step S37). Note that the corrected light distribution angle φ t can be obtained based on the above formulas (1) and (2). In this case, the light distribution pattern setting unit 13 sets the corrected light distribution angle φ tA light distribution pattern is set so that the headlight moves in a direction specified by, and a light distribution control signal corresponding to the light distribution pattern is generated by the control signal generating unit 14 and output to each headlight unit 5L, 5R (step S38). Each headlight unit 5L, 5R emits light so as to realize a light distribution corresponding to the set light distribution pattern. After that, the process returns to step S11, and the subsequent processes are performed.

[0059] 9(A) to 9(C) are diagrams for explaining light distribution control when the moving range of the line of sight remains in the blind area. For example, when the pre-correction light distribution angle and the line of sight angle at time (t-1) are both 0 (see FIG. 9(A)), and the line of sight angle at the next time (t) has a positive value and changes to remain in the blind area B (see FIG. 9(B)), the pre-correction light distribution angle is fixed at 0. Similarly, for example, when the line of sight angle at time (t+1) has a negative value and changes to remain in the blind area B (see FIG. 9(C)), the pre-correction light distribution angle is fixed at 0. In other words, even if the line of sight angle changes, if the line of sight angle after the change remains in the blind area B, the pre-correction light distribution angle is fixed at 0, and the post-correction light distribution angle is also fixed at 0. As a result, the high illuminance zone does not move, and the high illuminance zone is formed in the front direction of the vehicle (see FIG. 2(A)).

[0060] 10(A) to 10(D) are diagrams for explaining light distribution control when the movement range of the line of sight switches from the blind area to the line of sight linked area. For example, when the pre-correction light distribution angle and the line of sight angle are both 0 at time (t-1) (see FIG. 10(A)), and the line of sight angle at the next time (t) is a positive value and moves out of the blind area B and into the line of sight linked area A (see FIG. 10(B)), the pre-correction light distribution angle is set to the threshold value +Th1. Then, the pre-correction light distribution angle changes from 0 to +Th1 at an angular velocity w1 between time (t+1) and time (t+α) (see FIG. 10(C) and FIG. 10(D)). α is the time required for the high illuminance band to move from 0 to the threshold value +Th1 at an angular velocity w1. The same applies when the line of sight angle changes in the negative direction. In other words, when switching from the blind area to the gaze-linked area, the pre-correction light distribution angle changes from 0 to threshold+Th1 (or threshold-Th1) at a constant angular velocity w1. Accordingly, the post-correction light distribution angle also changes at each speed w1.

[0061] 11(A) to 11(D) are diagrams for explaining light distribution control when the movement range of the line of sight switches from the line of sight linked area to the insensitive area. For example, when the pre-correction light distribution angle and the line of sight angle at time (t-1) are both magnitudes that belong to the line of sight linked area (see FIG. 11(A)), and the line of sight angle at the next time (t) is a positive value and changes to belong to the insensitive area B (see FIG. 11(B)), the pre-correction light distribution angle is set to 0. Then, between time (t+1) and time (t+β), the pre-correction light distribution angle changes from the value at time (t) to 0 at an angular velocity w2 (see FIG. 11(C) and FIG. 11(D)). β is the time required for the high illuminance band to move from the value at time (t) to 0 at an angular velocity w2. The same applies when the line of sight angle changes from the line of sight linked area in the negative direction to the insensitive area. In other words, when switching from the line-of-sight linked area to the blind area, the pre-correction light distribution angle changes to 0 at the angular velocity w2, which is a constant angular velocity. Accordingly, the post-correction light distribution angle also changes at the angular velocity w2.

[0062] 12(A) to 12(C) are diagrams for explaining light distribution control when the movement range of the line of sight remains in the line of sight linkage area. For example, when the pre-correction light distribution angle and the line of sight angle at time (t-1) are both +Th1 (see FIG. 12(A)), and the line of sight angle at the next time (t) is a positive value and changes to belong to the line of sight linkage area A (see FIG. 12(B)), the pre-correction light distribution angle changes to follow the line of sight angle with a delay of an infinitesimal time Δt (see FIG. 12(C)). Even after that, the pre-correction light distribution angle is repeatedly tracked according to the change in the line of sight angle. In other words, after switching to the line of sight linkage area, the pre-correction light distribution angle is variably set for every infinitesimal time Δt in accordance with the change in the line of sight angle, and the post-correction light distribution angle is also variably set accordingly. As a result, the high illuminance band is variably set at any time in accordance with the line of sight change (see FIG. 2(B)).

[0063] According to the embodiment described above, when light distribution control is performed in accordance with the line of sight of the driver, it is possible to reduce the annoyance and discomfort felt by the driver.

[0064] The present disclosure is not limited to the contents of the above-mentioned embodiment, and various modifications can be made within the scope of the gist of the present disclosure. For example, the exponential moving average has been given as an example of the filter processing by the second filter setting unit 12 in the above-mentioned embodiment, but the filter processing is not limited to this, and may be, for example, a simple moving average. In this case, it is not the coefficient K that changes depending on the vehicle speed or the congestion level, but the number of samples N when taking the simple moving average. In addition, the line of sight tracking is not limited to the left-right direction, and may also be tracked in the up-down direction. In addition, in order to make the light distribution track the line of sight of a driver who frequently moves in a highly crowded environment, the tracking ability may be improved as the congestion level increases. In addition, in the above-mentioned embodiment, a high-illuminance zone is formed using a high beam unit with variable light distribution, but an auxiliary unit for forming a high-illuminance zone may also be used.

[0065] The present disclosure has the following features. (Appendix 1) A device for controlling a headlamp that can variably set a light distribution direction, An occupant monitoring device that detects at least a line of sight angle indicating a line of sight direction of a driver of the vehicle and a line of sight movement speed; a controller connected to each of the headlight, the passenger monitoring device, and the imaging device; Including, The controller: a first range being a relatively small angle range in absolute value from a reference position based on a traveling direction of the vehicle, and a second range being a relatively large angle range, when the line of sight angle falls within the first range, the light distribution direction is fixed without being changed, and when the line of sight angle falls within the second range, the light distribution direction is changed to follow the line of sight angle, and the headlight is controlled so as to emit light in the light distribution direction. Headlight control device. (Appendix 2) the controller controls the headlamp so as to move the light distribution direction to a boundary between the first range and the second range at a first angular velocity when the line of sight angle changes from a state belonging to the first range to a state belonging to the second range. 2. The control device according to claim 1. (Appendix 3) The controller: When the line of sight angle changes from a state belonging to the second range to a state belonging to the first range, the headlamp is controlled so as to move the light distribution direction to the reference position at a second angular velocity. 3. The control device according to claim 1 or 2. (Appendix 4) The first angular velocity is greater than the second angular velocity. 4. The control device according to claim 3. (Appendix 5) the controller sets the light distribution direction such that, after moving the light distribution direction to the boundary, the light distribution direction moves in accordance with a change in the line of sight angle while the line of sight angle is within the second range. 5. The control device according to claim 2, (Appendix 6) When setting the light distribution direction following a change in the line of sight angle, the controller calculates a filter coefficient using a line of sight coefficient according to a vehicle speed of the host vehicle, a congestion degree in front of the host vehicle, and a moving speed of the line of sight, and sets the light distribution direction using the filter coefficient. 6. The control device according to claim 5. (Appendix 7) The filter coefficient has a small value when the vehicle speed is relatively low, and has a large value when the vehicle speed is relatively high. 7. The control device according to claim 6. (Appendix 8) The filter coefficient has a small value when the congestion degree is relatively high, and has a large value when the congestion degree is relatively low. 8. The control device according to claim 6 or 7. (Appendix 9) the line-of-sight coefficient is set to a first value when the line-of-sight movement speed is greater than a predetermined criterion, and is set to a second value smaller than the first value when the line-of-sight movement speed is equal to or less than the predetermined criterion, The filter coefficient has a small value when the line of sight coefficient is relatively small, and has a large value when the line of sight coefficient is relatively large. 9. The control device according to any one of claims 6 to 8. (Appendix 10) A method for controlling a headlamp whose light distribution direction can be variably set, comprising: Detecting at least a line of sight angle indicating a line of sight direction of a driver of the vehicle and a line of sight movement speed; controlling the headlamp so that, when the line of sight angle falls within a first range, which is a range of angles that are relatively small in absolute value from a reference position based on a traveling direction of the vehicle, and a second range, which is a range of angles that are relatively large in absolute value from a reference position based on a traveling direction of the vehicle, the light distribution direction is fixed without being changed, and when the line of sight angle falls within the second range, the light distribution direction is changed to follow the line of sight angle, and light is emitted in the light distribution direction; A method for controlling a headlamp, comprising: (Appendix 11) A control device according to any one of appendix 1 to 9, A headlamp connected to the control device and whose operation is controlled by the control device; 2. A headlamp system comprising: [Explanation of symbols]

[0066] 1: controller, 2: imaging device, 3: passenger monitoring device, 4: vehicle speed sensor, 5L, 5R: headlamp unit, 11: first filter setting unit, 12: second filter setting unit, 13: light distribution pattern setting unit, 14: control signal generating unit, LB: low beam, HB: high beam, RB: high illuminance band

Claims

1. A device for controlling a headlamp that can variably set a light distribution direction, an occupant monitoring device that detects at least a line of sight angle indicating a line of sight direction of a driver of the vehicle and a line of sight movement speed; a controller connected to each of the headlight, the passenger monitoring device, and the imaging device; Including, The controller: a first range being a range of angles that are relatively small in absolute value from a reference position based on a traveling direction of the vehicle, and a second range being a range of angles that are relatively large in absolute value from a reference position based on a traveling direction of the vehicle, the light distribution direction is fixed without being changed when the line of sight angle falls within the first range, and the light distribution direction is changed to follow the line of sight angle when the line of sight angle falls within the second range, and the headlight is controlled so as to emit light in the light distribution direction. Headlight control device.

2. the controller controls the headlamp so as to move the light distribution direction to a boundary between the first range and the second range at a first angular velocity when the line of sight angle changes from a state belonging to the first range to a state belonging to the second range. The control device according to claim 1 .

3. The controller: When the line of sight angle changes from a state belonging to the second range to a state belonging to the first range, the headlamp is controlled so as to move the light distribution direction to the reference position at a second angular velocity. The control device according to claim 2.

4. The first angular velocity is greater than the second angular velocity. The control device according to claim 3.

5. the controller sets the light distribution direction such that, after the light distribution direction is moved to the boundary, the light distribution direction moves in accordance with a change in the line of sight angle while the line of sight angle is within the second range. The control device according to claim 2.

6. When setting the light distribution direction following a change in the line of sight angle, the controller calculates a filter coefficient using a line of sight coefficient corresponding to a vehicle speed of the host vehicle, a congestion degree in front of the host vehicle, and a moving speed of the line of sight, and sets the light distribution direction using the filter coefficient. The control device according to claim 5.

7. The filter coefficient has a small value when the vehicle speed is relatively low, and has a large value when the vehicle speed is relatively high. The control device according to claim 6.

8. The filter coefficient has a small value when the congestion degree is relatively high, and has a large value when the congestion degree is relatively low. The control device according to claim 6.

9. the line-of-sight coefficient is set to a first value when the line-of-sight movement speed is greater than a predetermined criterion, and is set to a second value smaller than the first value when the line-of-sight movement speed is equal to or less than the predetermined criterion, The filter coefficient has a small value when the line of sight coefficient is relatively small, and has a large value when the line of sight coefficient is relatively large. The control device according to claim 6.

10. A method for controlling a headlamp whose light distribution direction can be variably set, comprising: Detecting at least a line of sight angle indicating a line of sight direction of a driver of the vehicle and a line of sight movement speed; controlling the headlamp so that, when the line of sight angle falls within a first range, which is a range of angles that are relatively small in absolute value from a reference position based on a traveling direction of the vehicle, and a second range, which is a range of angles that are relatively large in absolute value from a reference position based on a traveling direction of the vehicle, the light distribution direction is fixed without being changed, and when the line of sight angle falls within the second range, the light distribution direction is changed to follow the line of sight angle, and light is emitted in the light distribution direction; A method for controlling a headlamp, comprising:

11. The control device according to claim 1 ; A headlamp connected to the control device and whose operation is controlled by the control device; 2. A headlamp system comprising:

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