JP2021075269A - Headlight control device - Google Patents

Abstract

To provide a vehicular headlight control device which is applied to a vehicle having a sensor for detecting the contraction length in a suspension device in any of front wheels and rear wheels, and which executes auto-leveling processing for controlling an irradiation angle of a headlight of the vehicle in accordance with a pitch angle of the vehicle.SOLUTION: A headlight control device acquires a pitch angle estimated on the basis of the contraction length as a reference pitch angle when a prescribed reference value acquisition condition is satisfied, acquires an infinite far point correlation value having the correlation with an infinite far point position expressing a position in the vertical direction of an image of an infinite far point included in an image obtained by photographing a region in the travel direction of the vehicle as a reference infinite far point correlation value, and acquires the pitch angle on the basis of the reference pitch angle, the reference infinite far point correlation value and the infinite far point correlation value when the reference value acquisition condition is not satisfied.SELECTED DRAWING: Figure 6

Description

The present invention relates to a vehicle headlight control device that automatically controls the headlight irradiation direction according to the pitch angle of the vehicle.

One of these types of headlight control devices (hereinafter, also referred to as "conventional device") is the amount of change in the height of the axle portion of the rear wheels (that is, the spring-loaded member of the vehicle with respect to the rotating shaft of the rear wheels. It is equipped with a vehicle height sensor that detects the relative displacement amount of the vehicle. In addition, the conventional apparatus acquires (estimates) the pitch angle based on the detected height change amount (see, for example, Patent Document 1). According to the conventional device, the pitch angle can be acquired without disposing the vehicle height sensor on both the front wheels and the rear wheels of the vehicle.

Japanese Unexamined Patent Publication No. 10-226271

However, even if the amount of change in height is the same, the pitch angle may be different. For example, even if the amount of change in height is the same, when luggage is loaded at a position behind the axle of the rear wheel (for example, the rear trunk of the vehicle), it is compared with the case where the luggage is not loaded. Then the vehicle leans backwards. In other words, even if the amount of change in height is the same, the position of the center of gravity of the vehicle occupant and the vehicle load including the luggage loaded on the vehicle (hereinafter, also referred to as "vehicle load") is different. For example, the pitch angle of the vehicle changes. That is, depending on the position of the center of gravity of the vehicle load, the difference between the pitch angle estimated by the conventional device and the actual pitch angle may become relatively large.

By the way, there are known vehicles equipped with a camera device that captures a region in the traveling direction of the vehicle and acquires a "traveling direction image". This type of vehicle has, for example, a driving support function that extracts a target appearing in a traveling direction image and automatically controls the speed and / or steering angle of the vehicle according to the type and position of the extracted target. provide.

Therefore, one of the objects of the present invention is to provide a headlight control device capable of accurately acquiring a pitch angle by using a camera device mounted on a vehicle.

The headlight control device (hereinafter, also referred to as “the device of the present invention”) for achieving the above object includes an actuator, a controller, a vehicle height sensor, and a camera device.

The actuator (46)
The irradiation angle (θb) of the headlight (low beam unit 31) of the vehicle (10) is changed.

The controller (headlight control ECU 20 and image processing unit 52)
The target irradiation angle (θbtgt) is acquired based on the pitch angle (θp) of the vehicle, and the actuator is controlled so that the irradiation angle matches the target irradiation angle (step 755 in FIG. 7).

The vehicle height sensor (61)
The relative displacement amount of the spring-loaded member of the vehicle with respect to the rotation axis of either the front wheel or the rear wheel of the vehicle is detected as the "contraction length (Ca)".

The camera device (50)
A "traveling direction image" is acquired by photographing a region in the traveling direction of the vehicle.

Further, the controller
The "point at infinity (Yi)" that is the position of the "point at infinity (for example, the point Pf in FIG. 4)" included in the moving direction image in the vertical direction of the moving direction image The "point at infinity acquisition process" for acquiring the "correlation value (point at infinity position Yi and current pitch angle θn)" is executed.

In addition, the controller
It is determined whether or not the predetermined "reference value acquisition condition" is satisfied.

The controller
When it is determined that the reference value acquisition condition is satisfied, the detected shrinkage length is applied to the relationship between the predetermined shrinkage length and the pitch angle (relationship represented by the straight line Le in FIG. 5). By applying, the reference pitch angle (θstd) is acquired, and the infinity point correlation value at that time is acquired as the reference infinity point correlation value (reference infinity point position Ystd and reference pitch angle θref). "Value acquisition process" is executed (steps 725 and 730 of FIGS. 7 and 10 and steps 925 and 730 of FIGS. 9 and 11).

On the other hand, the controller
When it is determined that the reference value acquisition condition is not satisfied, the pitch angle is acquired based on the reference pitch angle, the reference infinity point correlation value, and the current infinity point correlation value. "Angle estimation process" is executed (step 740 in FIGS. 7 and 10 and step 942 in FIGS. 9 and 11).

For example, if the infinity point position (image base point) when the pitch angle is 0 ° (that is, when the vehicle is neither tilted forward nor backward) is acquired in advance, the infinity point position and the image at the present time. The pitch angle can be obtained based on the difference from the base point. The image base point can be acquired based on, for example, an image taken by installing a target target in front of the camera device in a factory where the vehicle is manufactured, and the positional relationship between the camera device and the target target.

However, since it is often difficult to accurately place the target target at a fixed position in front of the camera device (that is, the vehicle), the error of the acquired image origin may be relatively large. Is high. On the other hand, it is possible to relatively accurately acquire the position of the point at infinity in the traveling direction image acquired when the vehicle is traveling by a well-known method. That is, it is possible to acquire the point at infinity correlation value based on the traveling direction image. Therefore, according to the apparatus of the present invention, the pitch angle can be accurately acquired based on the traveling direction image without disposing the vehicle height sensor on both the front wheels and the rear wheels of the vehicle.

In one aspect (first aspect) of the apparatus of the present invention
The controller
When the detected contraction length is included in a predetermined "reference range" (range from the first contraction length C1 to the second contraction length C2), it is determined that the reference value acquisition condition is satisfied.

The reference range in the apparatus of the present invention is, for example, the range of the contraction length at which the pitch angle can be obtained with relatively high accuracy based on the contraction length. In addition, the reference pitch angle and the reference infinity correlation value are acquired when the contraction length is included in the reference range. Therefore, even when the contraction length is not included in the reference range, the pitch angle can be accurately acquired based on the reference pitch angle and the reference infinity point correlation value.

Therefore, according to the first aspect, the pitch angle can be accurately acquired by using the camera device mounted on the vehicle.

In the first aspect
The controller
The reference range may be set to be included in the range from the minimum value to the maximum value of the contraction length acquired when the load of the vehicle is only the driver (see FIG. 5). ..

If the vehicle load is only the driver, the position of the center of gravity of the vehicle load is substantially the same even if the weight of the driver (that is, the weight) changes. Therefore, if the vehicle load is only the driver, the contraction length detected by the contraction length sensor is substantially the same. Therefore, according to this aspect, the reference pitch angle and the reference at infinity correlation value are acquired at a time when the difference between the pitch angle estimated based on the contraction length and the actual pitch angle is relatively small, and as a result, the pitch angle. The pitch angle can be obtained with high accuracy by the estimation process.

In another aspect (second aspect) of the apparatus of the present invention.
The controller
When the detected contraction length is smaller than the "value obtained by subtracting the predetermined difference threshold value (α) from the reference contraction length (Cstd)", it is determined that the reference value acquisition condition is satisfied.
When it is determined that the reference value acquisition condition is satisfied, the reference shrinkage length is updated so that the reference shrinkage length matches the detected shrinkage length.

In the period from the first running start time of the vehicle (the first running start time, that is, the time when the vehicle first runs after being manufactured) to the time when the reference value acquisition condition is first satisfied, the reference value acquisition process is still performed. Since it has not been executed, the pitch angle estimation process based on the reference pitch angle and the reference infinity point correlation value cannot be executed. Therefore, it is desirable that the period from the start of the first run to the time when the reference value acquisition condition is first satisfied is short.

According to the second aspect, after the first running start time, the contraction length is at a time before the initial value of the reference contraction length (that is, the reference value acquisition condition determined at the time of manufacturing the vehicle is first satisfied. The reference value acquisition condition is satisfied when the value becomes smaller than the value obtained by subtracting the predetermined difference threshold value from the reference contraction length). Therefore, according to this aspect, the period from the start of the first run to the time when the reference value acquisition condition is first satisfied can be shortened.

In the second aspect,
The controller
When the reference value acquisition process has not yet been executed, the reference contraction length is greater than "a value obtained by adding the difference threshold value to the upper limit value (maximum contraction length Cmax) in the range of values in which the contraction length is detected". It may be set to a large value (initial value of contraction length Ci).

According to this aspect, the period from the start time of the first run to the time when the reference value acquisition condition is first satisfied can be shortened more reliably.

In another aspect (third aspect) of the apparatus of the present invention.
The controller
In the pitch angle estimation process,
The difference (tan (θp) -tan (θstd)) between the tangent of the pitch angle at the present time and the tangent of the reference pitch angle is the difference between the reference infinity point correlation value and the point at infinity correlation value at the present time ( The pitch angle is acquired based on the relationship of being proportional to Ystd-Yi) (see equation (13)).

The point at infinity correlation value is, for example, the vertical position (pixel position) of the "pixel corresponding to the point at infinity" in the "traveling direction image which is a set of pixels". This pixel position changes according to a change in the pitch angle (specifically, the tangent of the pitch angle). Therefore, according to the third aspect, it is possible to accurately acquire the pitch angle by a well-known calculation method using trigonometric functions.

In another aspect (fourth aspect) of the apparatus of the present invention.
The controller
In the pitch angle estimation process,
The difference between the pitch angle and the reference pitch angle at the present time (pitch angle difference, θp−θstd) is the difference between the reference infinity point correlation value and the point at infinity correlation value at the present time (correlation value difference, Ystd−. The pitch angle is obtained based on the relationship of being proportional to Yi) (see equation (4)).

The pitch angle changes according to changes in the weight of the vehicle load and the position of the center of gravity. However, in general, the size of the pitch angle of the vehicle is not excessive. Therefore, the pitch angle acquisition error caused by acquiring the pitch angle so that the pitch angle difference is proportional to the correlation value difference is relatively small. In this case, the proportionality constant is determined by, for example, the angle of view (θa) representing the shooting range (angle of view) in the vertical direction of the camera device, which is determined by the "number of pixels in the vertical direction (vertical resolution Yd) constituting the image in the traveling direction". It is a value obtained by dividing. Therefore, according to the fourth aspect, it is possible to acquire the pitch angle with relatively high accuracy by a simple process.

In another aspect (fifth aspect) of the apparatus of the present invention.
The controller
In the infinity point acquisition process
The "specific infinity point position (image base point Yo)" which is the infinity point position acquired when the pitch angle is a predetermined "specific angle (0 °)" and the infinity point position at the present time A value proportional to the difference (Yo-Yi) of, is acquired as the point at infinity correlation value (current pitch angle θn).
In the reference value acquisition process
The value obtained by adding the reference pitch angle to the difference (displacement pitch angle θphoe) between the infinity point correlation value and the reference infinity point correlation value (reference pitch angle θref) is acquired as the pitch angle (Equation (9)). See.).

The specific angle is, for example, 0 ° (that is, the vehicle is neither tilted forward nor tilted backward). The specific point at infinity position is acquired, for example, based on the traveling direction image acquired when the vehicle is stopped. As described above, it is often difficult to accurately acquire the position of the point at infinity in the traveling direction image acquired when the vehicle is stopped.

On the other hand, in the fifth aspect, the contribution of the specific infinity point position in the difference between the reference infinity point correlation value and the current infinity point correlation value is offset. Therefore, according to the fifth aspect, even if it is difficult to accurately acquire the specific point at infinity position, it is possible to accurately acquire the pitch angle.

In the above description, in order to help the understanding of the present invention, the names and / or symbols used in the embodiments are added in parentheses to the configurations of the invention corresponding to the embodiments described later. However, each component of the present invention is not limited to the embodiment defined by the above name and / or reference numeral. Other objects, other features and accompanying advantages of the invention will be readily understood from the description of embodiments of the invention described with reference to the drawings below.

It is a side view of the vehicle (the present vehicle) to which the headlight control device (the first control device) which concerns on 1st Embodiment of this invention is applied. It is a block diagram of the 1st control device. It is a figure which showed the structure of the low beam unit provided in this vehicle. This is an example of a front image taken by a camera device provided in this vehicle. It is a graph which showed the relationship between the detection value (contraction length) of the vehicle height sensor provided in this vehicle, and the pitch angle of this vehicle. (A) is a side view of the vehicle when the pitch angle is the reference pitch angle, and (B) is a side view of the vehicle when the pitch angle is different from the reference pitch angle. It is a flowchart which showed the auto-leveling processing routine executed by the 1st control device. It is a figure which is referred to for explaining the process which the headlight control device (the first deformation device) which concerns on the 1st modification of 1st Embodiment of this invention acquires a pitch angle. It is a flowchart which showed the auto-leveling processing routine executed by the 1st transformation apparatus. It is a flowchart which showed the auto-leveling processing routine executed by the headlight control apparatus which concerns on 2nd Embodiment of this invention. It is a flowchart which showed the auto-leveling processing routine executed by the headlight control apparatus which concerns on the modification of 2nd Embodiment of this invention.

<First Embodiment>
Hereinafter, the headlight control device (hereinafter, also referred to as “first control device”) according to the first embodiment of the present invention will be described with reference to the drawings. The first control device is applied to the vehicle 10 shown in FIG. As understood from FIG. 2, which is a block diagram of the first control device, the first control device includes a headlight control ECU 20 which is an electronic control unit. Hereinafter, the headlight control ECU 20 is also simply referred to as an ECU 20.

The ECU 20 includes a microcomputer including a CPU 25, a ROM 26, a RAM 27, and a non-volatile memory 28 as main elements. The CPU 25 sequentially executes a predetermined program (routine) to read data, perform numerical calculation, output a calculation result, and the like. The ROM 26 stores a program executed by the CPU 25, a look-up table (map) referred to when the program is executed, and the like. The RAM 27 temporarily stores the data referenced by the CPU 25. The non-volatile memory 28 is composed of a data rewritable flash memory, and stores data unique to the vehicle 10 (for example, a reference infinity point position Ystd and a reference pitch angle θstd, which will be described later).

The ECU 20 is connected to the headlight 30, the camera device 50, the vehicle height sensor 61, and the dimmer switch 62.

The headlight 30 includes a low beam unit 31 and a high beam unit 32. The low beam unit 31 includes a left low beam unit 31a and a right low beam unit 31b.

The irradiation range of the low beam unit 31 (that is, the left low beam unit 31a and the right low beam unit 31b) in the vertical direction (vertical direction) is a range between the straight line Lb1 and the straight line Lb2 in FIG. The broken line Lba in FIG. 1 is a bisector of the angle formed by the straight line Lb1 and the straight line Lb2.

By the auto-leveling process described later, the irradiation direction of the low beam unit 31 represented by the broken line Lba is changed according to the pitch angle θp of the vehicle 10. More specifically, the pitch angle θp is parallel to the plane including the grounding points of the four wheels included in the vehicle 10 and extends in the front-rear direction of the vehicle 10 and the vehicle body of the vehicle 10 ( It is an angle formed by a "body horizon" that is parallel to the spring member) and extends in the front-rear direction of the vehicle 10.

In FIG. 1, the horizon Lh1 is the ground horizon, and the horizon Lh2 is the vehicle body horizon. The angle formed by the vehicle body horizon and the broken line Lba is also referred to as an irradiation angle θb. The auto-leveling process is a process of controlling the irradiation angle θb so that the angle formed by the broken line Lba (that is, the irradiation direction of the low beam unit 31) and the horizon to the ground coincides with a predetermined antiglare angle θh.

The pitch angle θp is an angle indicating the degree to which the vehicle 10 (specifically, the spring member) is tilted forward or backward. When the vehicle 10 is neither tilted forward nor tilted backward, the pitch angle θp becomes “0”. Therefore, when the pitch angle θp is “0”, the vehicle body horizon is parallel to the ground horizon.

When the vehicle 10 is tilted backward, the pitch angle θp becomes a positive value (that is, θp> 0), and when the vehicle 10 is tilted forward, the pitch angle θp becomes a negative value (that is, θp <. 0). In FIG. 1, the horizontal line Lh1 and the horizontal line Lh2 are parallel to each other, so that the pitch angle θp is “0”.

The structure of the left low beam unit 31a is shown in FIG. Since the structure of the right low beam unit 31b is the same as the structure of the left low beam unit 31a, the illustration is omitted. The left low beam unit 31a includes a bulb 41, a reflector 42, an upper rod 43, a lower rod 44, a unit case 45, and an actuator 46. The valve 41 is fixed to the reflector 42. The reflector 42 is supported by the unit case 45 via the upper rod 43 and the lower rod 44. The upper part of the reflector 42 is rotatably supported by the front end of the upper rod 43, and the lower part of the reflector 42 is rotatably supported by the front end of the lower rod 44. The unit case 45 is fixed to the vehicle body.

The length of the lower rod 44 changes due to the operation of the actuator 46 (moves back and forth in the axial direction in the front-rear direction of the vehicle body), so that the reflector 42 swings in the vertical direction of the vehicle 10. Specifically, when the lower rod 44 extends (that is, when its front end moves forward), the irradiation angle θb decreases, and the region irradiated by the left low beam unit 31a moves upward. When the lower rod 44 contracts (that is, when its front end moves rearward), the irradiation angle θb increases, and the region irradiated by the left low beam unit 31a moves downward. As will be described later, the ECU 20 controls the actuator 46, thereby controlling the irradiation angle θb.

As shown in FIG. 1, the camera device 50 is arranged in the vicinity of a rearview mirror (not shown) arranged in the upper part of the vehicle interior of the windshield of the vehicle 10. As shown in FIG. 2, the camera device 50 includes an image pickup unit 51 and an image processing unit 52. The image pickup unit 51 acquires a "front image" of a region in front of the vehicle 10 each time a predetermined time interval Δt elapses, and obtains information representing the front image (that is, still image data) in the image processing unit 52. Output to.

The photographing range (angle of view) in the vertical direction (vertical direction) of the imaging unit 51 is a range between the straight line Lc1 and the straight line Lc2 in FIG. The angle formed by the straight line Lc1 and the straight line Lc2 is the angle of view angle θa. The vertical (vertical) resolution of the front image (that is, the number of pixels constituting the front image in the vertical direction) is the vertical resolution Yd. The forward image is also referred to as a "traveling direction image" for convenience.

The image processing unit 52 acquires the front image (latest image) last acquired by the imaging unit 51 and the front image acquired immediately before the latest image (previous image, that is, acquired before the latest image by a time interval Δt). A large number of optical flow vectors (hereinafter, also simply referred to as "flow vectors") are acquired based on the obtained image).

More specifically, the image processing unit 52 divides the previous image into rectangles of a predetermined size (that is, treats the previous image as a set of rectangles), and at what position each of the rectangles appears in the latest image. To explore. If the search is successful, a flow vector is acquired starting from the position (moving source) of the rectangle in the previous image and ending at the position (moving destination) of the rectangle in the latest image. That is, the image processing unit 52 acquires the flow vector by a so-called block matching method.

When the flow vector is acquired, the image processing unit 52 acquires the point at infinity position Yi representing the vertical position of the point at infinity (FOE) in the front image (see FIG. 1). The point at infinity is a point representing the straight-ahead direction of the vehicle 10 traveling on a flat road in the front image. The point at infinity position Yi is represented by the position of the pixel corresponding to the point at infinity. When the point at infinity is at the lower end of the front image, the point at infinity position Yi is "1". When the point at infinity is at the upper end of the front image, the point at infinity position Yi is equal to the vertical resolution Yd.

The point at infinity position Yi is also referred to as an "infinity point correlation value" for convenience. The process of acquiring the point at infinity position Yi is also referred to as "point at infinity acquisition process" for convenience.

The method of acquiring the point at infinity will be described. FIG. 4 shows an image 71, which is an example of a front image acquired when the vehicle 10 is traveling straight. The point Pf in FIG. 4 indicates the point at infinity. Each of the arrows in image 71 represents a flow vector. The image 71 includes another vehicle 72. The other vehicle 72 is traveling in a lane (that is, an oncoming lane) opposite to the lane in which the vehicle 10 is traveling (own lane).

In the image 71, the "targets included in the image 71" other than the other vehicle 72 are stationary. As can be understood from FIG. 4, a straight line passing through the start point and the end point of the "flow vector whose start point is not included in the other vehicle 72 (that is, the flow vector included in the target whose start point is stationary)". Passes through the point Pf. In general, since most of the targets included in the forward image are stationary, most of the straight lines (vector extension lines) passing through the start points and end points of the acquired flow vectors pass through the points Pf.

Therefore, the image processing unit 52 acquires the points through which the plurality of vector extension lines pass (that is, the points at which the vector extension lines intersect each other) and the points through which the most vector extension lines pass are as infinity points. The image processing unit 52 outputs the acquired infinity point position Yi to the ECU 20 every time the time interval Δt elapses.

In addition to the ECU 20, the vehicle 10 extracts various targets included in the front image (for example, positions of other vehicles other than the vehicle 10, pedestrians, and own lane), and the positions of the extracted targets. It is equipped with an ECU (driving support ECU) that provides a "driving support function" that supports the driver of the vehicle 10 based on the above. However, the description regarding the operation of the driving support function and the driving support ECU will be omitted in the present specification.

The vehicle height sensor 61 is arranged in the suspension device for the rear wheels on the passenger seat side of the vehicle 10 (see FIG. 1). Specifically, since the vehicle 10 is a right-hand drive vehicle, the vehicle height sensor 61 is arranged in the suspension device for the left rear wheel. The vehicle height sensor 61 is the relative displacement amount of the spring member of the vehicle 10 with respect to the rotation shaft of the left rear wheel (that is, the attachment portion of the "left rear wheel suspension device" in the vehicle body of the vehicle 10 and the rotation shaft of the left rear wheel. The amount of displacement of the distance with respect to the reference length) is detected as the contraction length Ca, and a signal representing the contraction length Ca is output to the ECU 20. If the position of the center of gravity of the vehicle 10 occupant and the vehicle 10 load (that is, the vehicle load) including the load loaded on the vehicle 10 does not change, the contraction length Ca increases as the weight of the vehicle load increases. ..

The dimmer switch 62 is used by the driver for an operation for selecting the lighting state of the headlight 30. The driver can switch the operating state of the dimmer switch 62 between the "off position", the "low beam position" and the "high beam position".

When the operating state of the dimmer switch 62 is the low beam position, the ECU 20 lights the low beam unit 31 (that is, the left low beam unit 31a and the right low beam unit 31b). When the operating state of the dimmer switch 62 is the high beam position, the ECU 20 lights the low beam unit 31 and the high beam unit 32.

(Auto leveling process)
The ECU 20 executes an "auto leveling process" that keeps the angle between the irradiation direction of the low beam unit 31 (that is, the broken line Lba) and the horizontal line to the ground at the antiglare angle θh even when the pitch angle θp changes. .. That is, the ECU 20 acquires the pitch angle θp and controls the irradiation angle θb so that the relationship of the following equation (1) is established based on the acquired pitch angle θp. Specifically, the ECU 20 acquires (calculates) the target irradiation angle θbtgt by substituting the acquired pitch angle θp into the following equation (1a) so that the actual irradiation angle θb becomes equal to the target irradiation angle θbtgt. Controls the actuator 46.

θb = θh + θp …… (1)
θbtgt = θh + θp …… (1a)

A method of acquiring the pitch angle θp will be described. When the reference infinity point position Ystd and the reference pitch angle θstd, which will be described later, have not yet been acquired, the ECU 20 has a contraction length in the “relationship between the contraction length Ca and the estimated pitch angle θe” represented by the straight line Le in FIG. The estimated pitch angle θe is obtained by applying Ca. The relationship between the contraction length Ca represented by the straight line Le and the estimated pitch angle θe is stored in the ROM 26 in the form of a map (look-up table).

In this case, the ECU 20 substitutes the acquired estimated pitch angle θe as the pitch angle θp into the equation (1a) to calculate the target irradiation angle θbtgt. In addition, the ECU 20 controls the actuator 46 so that the actual irradiation angle θb matches the target irradiation angle θbtgt. The ECU 20 stores the relationship between the drive amount of the actuator 46 and the irradiation angle θb in advance in the ROM 26, and the drive amount of the actuator 46 required for the irradiation angle θb to match the target irradiation angle θbtgt is set in that relationship. It is calculated based on the calculation, and the actuator 46 is driven by the calculated drive amount.

The straight line Le in FIG. 5 is a straight line that passes through the point Pa1 and is acquired so that the sum of the distances between each of the points Pa2 to Pa5 and the straight line Le is minimized (that is, by the method of least squares). Point Pa1 is the contraction length when an occupant (specifically, an occupant of a predetermined standard weight) is seated only in the driver's seat of the vehicle 10 (that is, when only the driver is in the vehicle 10). It shows the relationship between Ca and the pitch angle θp. The point Pa2 represents the relationship between the contraction length Ca and the pitch angle θp when the occupant is seated in the driver's seat and the passenger seat.

The point Pa3 represents the relationship between the contraction length Ca and the pitch angle θp when the occupant is seated in all the seats of the vehicle 10. The point Pa4 represents the relationship between the contraction length Ca and the pitch angle θp when the occupants are seated in all the seats and a load of a predetermined weight is loaded on the rear trunk of the vehicle 10. The point Pa5 represents the relationship between the contraction length Ca and the pitch angle θp when the occupant is seated only in the driver's seat and a load of a predetermined weight is loaded on the rear trunk.

As can be understood from the points Pa1 to Pa5, the contraction length Ca and the pitch angle θp are not in a monotonically increasing relationship. In other words, even if the contraction length Ca is the same, the pitch angle θp differs depending on the position of the center of gravity of the vehicle load. Therefore, depending on the position of the center of gravity of the vehicle load, the estimated pitch angle θe obtained by applying the contraction length Ca to the “relationship between the contraction length Ca and the estimated pitch angle θe” represented by the straight line Le, and the actual pitch angle θe. The magnitude of the difference between the pitch angle θp and the pitch angle θp may be relatively large.

Therefore, the ECU 20 acquires the pitch angle θp based on the point at infinity position Yi by utilizing the fact that the pitch angle θp and the point at infinity position Yi are in a monotonically decreasing relationship. To specifically describe the relationship between the pitch angle θp and the point at infinity position Yi, as the pitch angle θp increases (that is, when the vehicle 10 tilts backward), the point at infinity position Yi decreases (that is, the front image). The upper point at infinity moves down). As the pitch angle θp decreases (ie, when the vehicle 10 leans forward), the point at infinity position Yi increases (ie, the point at infinity on the front image moves up).

When the pitch angle θp is “0”, the point at infinity position Yi becomes the image base point Yo. The image base point Yo is shown as a point on the line segment Lp representing the projection plane of the front image in FIG. In other words, when the pitch angle θp is “0”, the intersection (base point intersection) of the horizontal line Lh2, which is the vehicle body horizon passing through the camera device 50 (specifically, the imaging unit 51), and the line segment Lp is The image base point Yo. That is, if the length of the line segment Lp is regarded as the vertical resolution Yd, the length from the lower end of the line segment Lp to the intersection of the base points corresponds to the image base point Yo.

The pitch angle θp that is “0” is also referred to as a “specific angle” for convenience. The image base point Yo is also referred to as a "specific infinity point position" for convenience.

When the magnitude | θp | of the pitch angle θp is relatively small, the relationship of the following equation (2) is generally established between the pitch angle θp and the point at infinity position Yi.

θp = θa × (Yo-Yi) / Yd …… (2)

The image base point Yo can be acquired in advance. For example, when the vehicle 10 is manufactured, or when the camera device 50 is replaced, a "target target" is installed at a predetermined position in front of the vehicle 10, and the pitch angle θp is "0". The image base point Yo can be acquired based on the front image in which the target target acquired in is captured. However, in many cases, it is difficult to accurately stop the vehicle 10 at a predetermined position in a predetermined direction and set the target target at a predetermined position in order to acquire the image base point Yo. , It is difficult to accurately acquire the image base point Yo.

On the other hand, as described above, in many cases, the front image contains many stationary objects, so that the infinity point position Yi is accurately acquired based on the front image acquired while the vehicle 10 is traveling. be able to. Therefore, the ECU 20 acquires the pitch angle θp based on the point at infinity position Yi regardless of the image base point Yo.

More specifically, the ECU 20 is based on a reference pitch angle θstd which is a pitch angle θp and a reference infinity point position Ystd which is an infinity point position Yi when the pitch angle θp is a reference pitch angle θstd. To obtain the pitch angle θp. The reference infinity point position Ystd is also referred to as a "reference infinity point correlation value" for convenience. The following equation (3) can be obtained by substituting the reference pitch angle θstd and the reference infinity point position Ystd into the equation (2).

θstd = θa × (Yo-Ystd) / Yd …… (3)

The vehicle 10 in a situation where the pitch angle θp is the reference pitch angle θstd is shown in FIG. 6 (A). The angle formed by the horizontal line Lh3, which is the horizontal line to the ground in FIG. 6A, and the straight line Lf1 which is the horizontal line of the vehicle body is the reference pitch angle θstd (that is, the pitch angle θp in this case). In this example, the vehicle 10 is tilted forward, so that the pitch angle θp is a negative value.

Further, the following equation (4) is obtained by subtracting the equation (3) from the equation (2) (that is, by erasing the image base point Yo).

θp−θstd = θa × (Ystd−Yi) / Yd …… (4)

The vehicle 10 in a situation where the pitch angle θp is different from the reference pitch angle θstd is shown in FIG. 6 (B). The angle formed by the horizontal line Lh4, which is the horizontal line to the ground in FIG. 6B, and the straight line Lf2, which is the horizontal line of the vehicle body, is the pitch angle θp in this example. The straight line Lst1 in FIG. 6B is a straight line in which the angle formed by the straight line Lf2 is the reference pitch angle θstd. In this example, the vehicle 10 is tilted backward, so that the pitch angle θp is a positive value.

As can be understood from FIG. 6B, the equation (4) shows the angle formed by the horizontal line Lh4 and the straight line Lst1 (θp−θstd), and the reference infinity point position Ystd and the infinity point position Yi. It shows the relationship with the difference (Ystd-Yi).

The following equation (5) can be obtained from the equation (4).

θp = θa × (Ystd-Yi) / Yd + θstd …… (5)

Therefore, according to the equation (5), the pitch angle θp can be acquired based on the infinity point position Yi even when the image base point Yo cannot be acquired with high accuracy.

Next, a method of acquiring the reference pitch angle θstd and the reference infinity point position Ystd will be described. When the vehicle load is only the driver (that is, when the occupant is present only in the driver's seat of the vehicle 10 and the vehicle 10 is not loaded with luggage), the contraction length Ca is regardless of the weight of the driver. The values are almost the same. In other words, even if the weight of the driver changes as a result of the change of the driver, the amount of change in the contraction length Ca is small and the position of the center of gravity of the vehicle load is substantially the same.

Therefore, the ECU 20 acquires the combination of the estimated pitch angle θe and the infinity point position Yi when the vehicle load is only the driver as the combination of the reference pitch angle θstd and the reference infinity point position Ystd.

Specifically, the ECU 20 applies the contraction length Ca when the vehicle load is only the driver to the “relationship between the contraction length Ca and the estimated pitch angle θe” represented by the straight line Le, and the estimated pitch is obtained. The angle θe is stored in the non-volatile memory 28 as the reference pitch angle θstd. In addition, the ECU 20 stores the infinity point position Yi in this case as the reference infinity point position Ystd in the non-volatile memory 28.

At the time when the vehicle 10 is manufactured, the reference pitch angle θstd and the reference infinity point position Ystd are not stored in the non-volatile memory 28. In addition, when the camera device 50 is replaced or repaired, the reference pitch angle θstd and the reference infinity point position Ystd are erased from the non-volatile memory 28.

When the contraction length Ca is larger than the predetermined first contraction length C1 and smaller than the second contraction length C2 (C1 <Ca <C2), the ECU 20 determines that the vehicle load is only the driver. The range from the first contraction length C1 to the second contraction length C2 of the contraction length Ca is also referred to as a "reference range" for convenience. The condition that is satisfied when the contraction length Ca is included in the reference range is also referred to as a "reference value acquisition condition" for convenience.

(Specific operation)
Next, the specific operation of the ECU 20 related to the auto-leveling process will be described. The CPU 25 of the ECU 20 (hereinafter, also simply referred to as “CPU”) executes the “auto-leveling processing routine” represented by the flowchart in FIG. 7 every time a predetermined time smaller than the time interval Δt elapses.

Therefore, at an appropriate timing, the CPU starts the process from step 700 in FIG. 7 and proceeds to step 705 to determine whether or not the point at infinity position Yi is newly received. That is, the CPU determines whether or not the infinity point position Yi has been received from the camera device 50 during the period from the time when this routine was last executed to the present time.

If the CPU has not newly received the point at infinity position Yi, the CPU determines "No" in step 705, proceeds directly to step 795, and ends the processing of this routine.

On the other hand, if the CPU newly receives the infinity point position Yi, it determines "Yes" in step 705 and proceeds to step 710 to acquire the contraction length Ca detected by the vehicle height sensor 61. Next, the CPU proceeds to step 715 and acquires the estimated pitch angle θe by applying the contraction length Ca to the “relationship between the contraction length Ca and the estimated pitch angle θe” represented by the straight line Le in FIG.

Further, the CPU proceeds to step 720 and determines whether or not the contraction length Ca is included in the range from the first contraction length C1 to the second contraction length C2 (that is, whether or not the contraction length Ca is included in the reference range). To judge.

If the contraction length Ca is included in the range from the first contraction length C1 to the second contraction length C2, the CPU determines "Yes" in step 720, proceeds to step 725, and sets the infinity point position Yi. It is stored in the non-volatile memory 28 as the reference infinity point position Ystd. Next, the CPU proceeds to step 730 and stores the estimated pitch angle θe as the reference pitch angle θstd in the non-volatile memory 28. The process of acquiring the reference pitch angle θstd and the reference infinity point position Ystd (that is, the reference infinity point correlation value) is also referred to as “reference value acquisition process” for convenience. Further, the CPU proceeds to step 735.

On the other hand, if the contraction length Ca is not included in the range from the first contraction length C1 to the second contraction length C2, the CPU determines "No" in step 720 and proceeds directly to step 735.

In step 735, the CPU determines whether or not the reference infinity point position Ystd and the reference pitch angle θstd have been acquired. That is, the CPU determines whether or not the reference infinity point position Ystd and the reference pitch angle θstd are stored in the non-volatile memory 28.

If the reference infinity point position Ystd and the reference pitch angle θstd are acquired, the CPU determines “Yes” in step 735 and proceeds to step 740 to proceed to the reference infinity point position Ystd, the reference pitch angle θstd, and infinity. The pitch angle θp is acquired based on the point at infinity position Yi. Specifically, the CPU acquires (calculates) the pitch angle θp by substituting the reference infinity point position Ystd, the reference pitch angle θstd, and the infinity point position Yi into the above equation (5). The process of acquiring the pitch angle θp based on the reference infinity point position Ystd, the reference pitch angle θstd, and the infinity point position Yi is also referred to as “pitch angle estimation process” for convenience. The CPU then proceeds to step 750.

On the other hand, if the reference infinity point position Ystd and the reference pitch angle θstd are not acquired, the CPU determines “No” in step 735, proceeds to step 745, and sets the pitch angle θp to a value equal to the estimated pitch angle θe. Get as. The CPU then proceeds to step 750.

In step 750, the CPU determines whether or not the low beam unit 31 is lit. That is, the CPU determines whether or not the operating state of the dimmer switch 62 is either the low beam position or the high beam position.

If the low beam unit 31 is lit, the CPU determines “Yes” in step 750, proceeds to step 755, and controls the irradiation angle θb. More specifically, the CPU acquires (calculates) the target irradiation angle θbtgt by substituting the pitch angle θp into the above equation (1a). In addition, the CPU controls the actuator 46 so that the actual irradiation angle θb matches the target irradiation angle θbtgt. The CPU then proceeds to step 795.

On the other hand, if the low beam unit 31 is not lit, the CPU determines "No" in step 750 and proceeds directly to step 795.

(First Modified Example of First Embodiment)
Next, the headlight control device (hereinafter, also referred to as “first deformation device”) according to the first modification of the first embodiment of the present invention will be described. The first control device described above has acquired the pitch angle θp based on the reference infinity point position Ystd and the reference pitch angle θstd acquired when the contraction length Ca is included in the reference range. On the other hand, the first deformation device acquires the pitch angle θp based on the reference pitch angle θstd and the reference pitch angle θref acquired when the contraction length Ca is included in the reference range. Hereinafter, this difference will be mainly described.

The headlight control ECU 21 (hereinafter, also simply referred to as ECU 21) according to the first deformation device is said to have a contraction length Ca included in the reference range (that is, the vehicle load is only the driver). (When determined), the reference pitch angle θstd and the reference pitch angle θref are acquired and stored in the non-volatile memory 28. The reference pitch angle θref is also referred to as a “reference infinity point correlation value” for convenience. When the contraction length Ca is not included in the reference range, the ECU 21 acquires the pitch angle θp based on the reference pitch angle θstd and the reference pitch angle θref.

A specific description will be given with reference to FIG. When the contraction length Ca is included in the reference range, the ECU 21 currently substitutes the point at infinity position Yi and the image base point Yo previously acquired and stored in the non-volatile memory 28 into the following equation (6). The pitch angle θn is calculated. The current pitch angle θn is also referred to as “point at infinity correlation value” for convenience. Equation (6) expresses the same relationship as Equation (2) described above.

θn = θa × (Yo-Yi) / Yd …… (6)

In addition, the ECU 21 currently acquires the pitch angle θn as the reference pitch angle θref. If the infinity point position Yi in this case is treated as the reference infinity point position Ystd, the relationship of the following equation (7) is established.

θref = θa × (Yo-Ystd) / Yd …… (7)

Further, the ECU 21 acquires the estimated pitch angle θe by applying the contraction length Ca to the “relationship between the contraction length Ca and the estimated pitch angle θe” represented by the straight line Le. In addition, the ECU 21 acquires the estimated pitch angle θe as the reference pitch angle θstd.

FIG. 8 shows an example in which the contraction length Ca is not included in the reference range after the reference pitch angle θstd and the reference pitch angle θref have been acquired. The angle formed by the horizontal line Lh5, which is the horizontal line to the ground in FIG. 8, and the straight line Lf3, which is the horizontal line of the vehicle body, is the pitch angle θp in this example. The straight line Lst2 in FIG. 8 is a straight line in which the angle formed by the straight line Lf3 is the reference pitch angle θstd. In this example, the vehicle 10 is tilted backward, so that the pitch angle θp is a positive value.

When the contraction length Ca is not included in the reference range, the ECU 21 calculates the current pitch angle θn based on the equation (6) and substitutes the current pitch angle θn into the following equation (8) to obtain the displacement pitch angle. Calculate θfoe. The displacement pitch angle θfoe represents the angle formed by the horizontal line Lh5 and the straight line Lf3. In other words, the displacement pitch angle θphoe corresponds to the difference between the pitch angle θp at the time when the above-mentioned reference pitch angle θstd and the reference pitch angle θref are acquired and the pitch angle θp at the present time.

θfoe = θn−θref …… (8)

In addition, the ECU 21 acquires (calculates) the pitch angle θp based on the following equation (9).

θp = θfoe + θstd …… (9)

Here, the reason for acquiring the pitch angle θp using the displacement pitch angle θfoe will be described. The following equation (10) can be obtained from the equations (6) to (9).

θp = (θn−θref) + θstd
= {Θa × (Yo-Yi) / Yd-θa × (Yo-Yref) / Yd}
＋ θstd …… (10)

It is highly possible that the reference pitch angle θstd acquired when it is determined that the vehicle load is only the driver has a small difference from the actual pitch angle θp at that time. On the other hand, since the reference pitch angle θref acquired at the same timing as the reference pitch angle θstd is calculated based on the image base point Yo, the difference from the actual pitch angle θp at that time is relatively large. there is a possibility.

Further, since the current pitch angle θn acquired at the present time is calculated based on the image base point Yo as in the reference pitch angle θref, the difference from the actual pitch angle θp at the present time can be relatively large. There is sex. However, since the displacement pitch angle θfoe is acquired as the difference between the current pitch angle θn and the reference pitch angle θref at the present time, the error due to the acquisition accuracy of the image base point Yo is offset.

In other words, the displacement pitch angle θfoe accurately represents the difference between the current pitch angle θp and the reference pitch angle θstd. Therefore, according to the first deforming device, the pitch angle θp at the present time can be accurately acquired based on the equation (9) even when the image base point Yo is not accurately acquired.

(Specific operation)
Next, the specific operation of the ECU 21 related to the auto-leveling process will be described. The CPU 25 of the ECU 21 (hereinafter, also simply referred to as “CPU”) executes the “auto-leveling processing routine” represented by the flowchart in FIG. 9 every time a predetermined time smaller than the time interval Δt elapses.

The steps shown in the flowchart of FIG. 9 and in which the same processing as the steps shown in the flowchart of FIG. 7 is executed are given the same step reference numerals as those in FIG. 7.

At an appropriate timing, the CPU starts the process from step 900 in FIG. 9 and proceeds to step 705. When the processing of step 715 is executed, the CPU proceeds to step 917 and calculates the current pitch angle θn based on the above equation (6) (that is, based on the image base point Yo and the infinity point position Yi). The CPU then proceeds to step 720.

When the CPU determines "Yes" in step 720 (that is, if the contraction length Ca is included in the reference range), the CPU proceeds to step 925 and sets the current pitch angle θn as the reference pitch angle θref in the non-volatile memory 28. Remember. Next, the CPU proceeds to step 730 and stores the estimated pitch angle θe as the reference pitch angle θstd in the non-volatile memory 28. The process of acquiring the reference pitch angle θstd and the reference pitch angle θref (that is, the reference infinity point correlation value) is also referred to as “reference value acquisition process” for convenience. Further, the CPU proceeds to step 935.

On the other hand, if the CPU determines "No" in step 720, the CPU directly proceeds to step 935.

In step 935, the CPU determines whether or not the reference pitch angle θstd and the reference pitch angle θref have been acquired. That is, the CPU determines whether or not the reference pitch angle θstd and the reference pitch angle θref are stored in the non-volatile memory 28.

If the reference pitch angle θstd and the reference pitch angle θref have been acquired, the CPU determines “Yes” in step 935, proceeds to step 940, and acquires the displacement pitch angle θfoe based on the above equation (8). .. Next, the CPU proceeds to step 942 and acquires the pitch angle θp based on the above equation (9). The process of acquiring the pitch angle θp based on the reference pitch angle θref, the reference pitch angle θstd, and the current pitch angle θn is also referred to as “pitch angle estimation process” for convenience. Further, the CPU proceeds to step 750.

On the other hand, if the reference pitch angle θstd and the reference pitch angle θref have not been acquired, the CPU determines “No” in step 935 and proceeds to step 745.

(Second modification of the first embodiment)
Next, the headlight control device (hereinafter, also referred to as “second deformation device”) according to the second modification of the first embodiment of the present invention will be described. The above-mentioned first control device acquired the pitch angle θp based on the above-mentioned equation (5). On the other hand, the second deforming device differs only in that the pitch angle θp is acquired based on the following equation (14). Therefore, this difference will be mainly described below.

As can be seen from the right triangle defined by the horizontal line Lh4, the straight line Lf2 and the line segment Lp in FIG. 6B (the angle formed by the horizontal line Lh4 and the line segment Lp is a right angle), the pitch angle θp, The relationship of the following equation (11) is established between the image base point Yo and the infinity point position Yi. In equation (11), K is a positive constant.

tan (θp) = K × (Yo-Yi) …… (11)

The following equation (12) can be obtained by substituting the reference pitch angle θstd and the reference infinity point position Ystd into the equation (11).

tan (θstd) = K × (Yo-Ystd) …… (12)

Further, the following equation (13) is obtained by subtracting the equation (12) from the equation (11) (that is, by erasing the image base point Yo). Therefore, the pitch angle θp can be obtained based on the following equation (14). More specifically, the headlight control ECU 22 according to the second transforming device sets the reference infinity point position Ystd, the reference pitch angle θstd, and the infinity point position Yi when executing the process of step 740 of FIG. The pitch angle θp is acquired (calculated) by substituting into equation (14).

tan (θp) -tan (θstd) = K × (Ystd-Yi) …… (13)
tan (θp) = K × (Ystd-Yi) + tan (θstd) …… (14)

<Second Embodiment>
Next, the second embodiment of the present invention will be described. The first control device described above has acquired the reference infinity point position Ystd and the reference pitch angle θstd when the contraction length Ca is included in the reference range. On the other hand, in the headlight control device (hereinafter, also referred to as “second control device”) according to the second embodiment, the contraction length Ca is “a predetermined difference threshold value α (positive constant) from the reference contraction length Cstd). When it is smaller than "a value obtained by subtracting" (that is, Ca <Cstd-α), the reference infinity point position Ystd and the reference pitch angle θstd are acquired. Hereinafter, this difference will be mainly described.

The reference contraction length Cstd is the contraction length Ca when the reference infinity point position Ystd and the reference pitch angle θstd are acquired. In other words, every time the contraction length Ca becomes smaller than the "value obtained by subtracting the difference threshold value α from the reference contraction length Cstd", the reference infinity point position Ystd and the reference pitch angle θstd are newly acquired (updated). Moreover, the contraction length Ca at that time is newly acquired (updated) as the reference contraction length Cstd. The condition that is satisfied when the contraction length Ca is smaller than the "value obtained by subtracting the difference threshold value α from the reference contraction length Cstd" is also referred to as a "reference value acquisition condition" for convenience.

The reference contraction length Cstd stored in the non-volatile memory 28 at the time when the vehicle 10 is manufactured is equal to a predetermined contraction length initial value Ci. The initial contraction length Ci is a value larger than the “maximum contraction length Cmax plus the difference threshold value α” (that is, Cmax + α <Ci). The maximum contraction length Cmax is a value substantially equal to the upper limit value of the range of the contraction length Ca detected by the vehicle height sensor 61 (see FIG. 5). When the camera device 50 is replaced or repaired, the reference contraction length Cstd is set to the initial contraction length Ci.

Since the contraction length Ca acquired when the vehicle 10 is first running after being manufactured is smaller than the "value obtained by subtracting the difference threshold value α from the initial contraction length Ci", the reference value acquisition condition. Is established. Therefore, at this time, the contraction length Ca is acquired (stored) as the reference contraction length Cstd, and the reference infinity point position Ystd and the reference pitch angle θstd are acquired. After that, when the contraction length Ca becomes smaller than the "value obtained by subtracting the difference threshold value α from the reference contraction length Cstd", the reference infinity point position Ystd and the reference pitch angle θstd are newly acquired.

The difference threshold value α is set to a small value as compared with the amount of change in the contraction length Ca when the number of occupants decreases, and the vehicle 10 is running even though the vehicle load has not changed. It is predetermined so that the reference value acquisition condition is not repeatedly satisfied.

(Specific operation)
The specific operation of the headlight control ECU 23 (hereinafter, also simply referred to as ECU 23) according to the second control device will be described. The CPU 25 of the ECU 23 (hereinafter, also simply referred to as “CPU”) executes the “auto-leveling processing routine” represented by the flowchart in FIG. 10 every time a predetermined time smaller than the time interval Δt elapses.

The steps shown in the flowchart of FIG. 10 and in which the same processing as the steps shown in the flowchart of FIG. 7 is executed are given the same step reference numerals as those in FIG. 7.

At an appropriate timing, the CPU starts the process from step 1000 in FIG. 10 and proceeds to step 705. When the process of step 715 is executed, the CPU proceeds to step 1020 and determines whether or not the contraction length Ca is smaller than the "value obtained by subtracting the difference threshold value α from the reference contraction length Cstd".

If the contraction length Ca is smaller than the "value obtained by subtracting the difference threshold value α from the reference contraction length Cstd", the CPU determines "Yes" in step 1020, proceeds to step 1022, and uses the contraction length Ca as the reference contraction. It is stored in the non-volatile memory 28 as a long Cstd. The CPU then proceeds to step 725.

On the other hand, if the contraction length Ca is equal to or greater than the “value obtained by subtracting the difference threshold value α from the reference contraction length Cstd”, the CPU determines “No” in step 1020 and proceeds directly to step 735.

When the CPU finishes the process of step 755, it proceeds to step 1095 and finishes the process of this routine. In addition, if the determination condition of step 705 is not satisfied (that is, if the infinity point position Yi is not newly received), it is determined as "No" in step 705, and the process directly proceeds to step 1095.

(Modified example of the second embodiment)
Next, a headlight control device (hereinafter, also referred to as a “third deforming device”) according to a modified example of the second embodiment of the present invention will be described. The second control device described above has acquired the pitch angle θp based on the reference infinity point position Ystd and the reference pitch angle θstd acquired when the reference value acquisition condition is satisfied. On the other hand, the third deforming device acquires the pitch angle θp based on the reference pitch angle θstd and the reference pitch angle θref acquired when the reference value acquisition condition is satisfied, similarly to the first deforming device described above. ..

The CPU 25 (hereinafter, also simply referred to as “CPU”) of the headlight control ECU 24 (hereinafter, also simply referred to as ECU 24) according to the third transforming device is the “auto” represented by the flowchart in FIG. The "leveling processing routine" is executed every time a predetermined time smaller than the time interval Δt elapses.

The steps shown in the flowchart of FIG. 11 and in which the same processing as the steps shown in the flowchart of FIG. 7 is executed are given the same step reference numerals as those in FIG. 7. Similarly, the steps shown in the flowchart of FIG. 11 and in which the same processing as the steps shown in the flowchart of FIG. 9 or 10 are executed are designated by the same step codes as those in FIG. 9 or 10. Has been done.

At an appropriate timing, the CPU starts the process from step 1100 in FIG. 11 and proceeds to step 705. When the CPU executes the process of step 917, the CPU proceeds to step 1020. When the CPU executes the process of step 1022, the CPU proceeds to step 925.

When the CPU finishes the process of step 755, it proceeds to step 1195 and finishes the process of this routine. In addition, if the determination condition of step 705 is not satisfied (that is, if the infinity point position Yi is not newly received), the CPU determines "No" in step 705 and directly proceeds to step 1195. move on.

As described above, the first control device and the second control device have a pitch angle θp based on the contraction length Ca acquired by the vehicle height sensor 61 and the infinity point position Yi acquired by the camera device 50. Can be obtained. In other words, according to the first control device and the second control device, the camera device 50 for providing the driving support function even if the vehicle height sensor 61 is arranged only on the suspension device of the rear wheels of the vehicle 10. Can be diverted to obtain the pitch angle θp.

In particular, according to the first control device (and the first deformation device and the second deformation device), it is based on the reference pitch angle and the reference infinity point correlation value acquired when the contraction length Ca is included in the reference range. Therefore, the pitch angle θp can be acquired with high accuracy. According to the second control device (and the third deforming device), the reference pitch angle and the reference infinity point correlation value are acquired at an early stage after the vehicle 10 is manufactured, so that the reference pitch angle and the reference infinity point correlation are obtained. It is possible to increase the chance of acquiring the pitch angle θp based on the value.

Although the embodiment of the headlight control device according to the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the object of the present invention. For example, in the present embodiment, the image processing unit 52 has acquired the point at infinity position Yi. However, the point at infinity position Yi may be acquired by the ECU 20. In this case, the image processing unit 52 outputs information representing the front image (that is, still image data) to the ECU 20 every time the time interval Δt elapses.

In addition, the image processing unit 52 according to the present embodiment outputs the point at infinity position Yi to the ECU 20 every time the time interval Δt elapses. However, the image processing unit 52 is configured so that the infinity point position Yi is not output to the ECU 20 when the infinity point position Yi cannot be acquired accurately (for example, when the vehicle 10 is stopped). May be done.

In addition, the ECU 20 according to the first control device has acquired the reference infinity point position Ystd and the reference pitch angle θstd regardless of whether or not the contraction length Ca is included in the reference range (that is, FIG. 7). (If "Yes" is determined in step 735), the pitch angle θp is acquired based on the reference infinity point position Ystd, the reference pitch angle θstd, and the infinity point position Yi. That is, in this case, the ECU 20 was executing the process of step 740. However, when the contraction length Ca is included in the reference range, the ECU 20 may acquire the pitch angle θp by a process different from that in step 740. For example, in this case, the ECU 20 may acquire the pitch angle θp as a value equal to the estimated pitch angle θe acquired by the process of step 715.

In addition, the ECU 20 according to the first control device determines that the vehicle load is only the driver when the contraction length Ca is larger than the first contraction length C1 and smaller than the second contraction length C2. In other words, the first contraction length C1 was set so as to substantially coincide with the lower limit of the range of the value of the contraction length Ca when the vehicle load was only the driver. However, the first contraction length C1 may be set so as to substantially match the value of the contraction length Ca when there is no vehicle load.

In addition, the ECU 23 related to the second control device acquires the pitch angle θp by substituting the reference infinity point position Ystd, the reference pitch angle θstd, and the infinity point position Yi into the above equation (5) (FIG. FIG. See step 740 in 10). However, the ECU 23 may acquire the pitch angle θp by substituting the reference infinity point position Ystd, the reference pitch angle θstd, and the infinity point position Yi into the equation (14).

In addition, the "specific angle" in this embodiment was "0". However, the "specific angle" may be a value other than "0". In this case, the image base point Yo is the point at infinity position Yi acquired when the pitch angle θp is the specific angle (different from “0”).

In addition, the difference threshold α in the second embodiment was a predetermined positive value. However, the difference threshold value α may be “0”.

In addition, the ECU 20 according to the first control device applies the contraction length Ca to the “relationship between the contraction length Ca and the estimated pitch angle θe” represented by the straight line Le when the contraction length Ca is included in the reference range. As a result, the reference pitch angle θstd was acquired. However, when the contraction length Ca is included in the reference range, the ECU 20 acquires the reference pitch angle θstd based on the “relationship between the contraction length Ca and the estimated pitch angle θe” which is different from the relationship represented by the straight line Le. You may.

In this case, for example, the ECU 20 has a plurality of "contraction lengths" obtained by seating a plurality of drivers having different weights and the vehicle load is only the driver, in addition to the relationship represented by the straight line Le. The “relationship (specific relationship) between the contraction length Ca and the estimated pitch angle θe” acquired based on the “combination of Ca and the pitch angle θp” is stored in the non-volatile memory 28. In addition, when the contraction length Ca is included in the reference range, the ECU 20 may acquire the reference pitch angle θstd by applying the contraction length Ca to a specific relationship.

In addition, in the present embodiment, the irradiation angle θb is changed by the operation of the actuator 46. However, the irradiation angle θb may be changed by a method different from this. For example, in the low beam unit 31, the region where the light of the bulb 41 is irradiated changes by changing the position of the shielding plate arranged in front of the bulb 41, and as a result, the irradiation angle θb is changed. It may be configured.

In addition, the vehicle height sensor 61 according to the present embodiment is arranged in the suspension device for the rear wheels on the passenger seat side of the vehicle 10. However, the two vehicle height sensors may be arranged in the suspension devices arranged on the rear wheels of the vehicle 10. In this case, the ECU 20 may acquire the average value of the values detected by each of the two vehicle height sensors as the contraction length Ca. Alternatively, the vehicle height sensor 61 may be arranged in the suspension device for the front wheels of the vehicle 10.

In addition, the first control device and the second control device have acquired the pitch angle θp regardless of whether or not the low beam unit 31 is lit. However, the ECU 20 may acquire the pitch angle θp only when the low beam unit 31 is lit.

In addition, the camera device 50 according to the present embodiment has photographed an area in front of the vehicle 10. However, the camera device 50 may be arranged in the vehicle 10 so as to photograph an area in the rear in addition to the area in front of the vehicle 10.

10 ... Vehicle, 20 ... Headlight control ECU, 23 ... CPU, 24 ... ROM, 25 ... RAM, 26 ... Non-volatile memory, 30 ... Headlight, 31 ... Low beam unit, 31a ... Left low beam unit, 31b ... Right Low beam unit, 32 ... High beam unit, 41 ... Valve, 42 ... Reflector, 43 ... Upper rod, 44 ... Lower rod, 45 ... Unit case, 46 ... Actuator, 50 ... Camera device, 51 ... Imaging unit, 52 ... Image processing Department, 61 ... Vehicle height sensor, 62 ... Dimmer switch.

Claims (8)

An actuator that changes the irradiation angle of the vehicle's headlights,
A controller that acquires a target irradiation angle based on the pitch angle of the vehicle and controls the actuator so that the irradiation angle matches the target irradiation angle.
It is a headlight control device equipped with
A vehicle height sensor that detects the relative displacement of the spring-loaded member of the vehicle with respect to the rotation axis of either the front wheel or the rear wheel of the vehicle as the contraction length.
A camera device that acquires a traveling direction image by photographing an area in the traveling direction of the vehicle, and a camera device.
With
The controller
An infinity point acquisition process for acquiring an infinity point correlation value having a correlation with the infinity point position, which is the position of the infinity point included in the traveling direction image in the vertical direction of the traveling direction image, is executed.
Judge whether or not the predetermined standard value acquisition condition is satisfied,
When it is determined that the reference value acquisition condition is satisfied, the reference pitch angle is acquired by applying the detected contraction length to the relationship between the predetermined contraction length and the pitch angle, and the reference pitch angle is acquired. , The reference value acquisition process for acquiring the infinity point correlation value at that time as the reference infinity point correlation value is executed.
When it is determined that the reference value acquisition condition is not satisfied, the pitch angle for acquiring the pitch angle based on the reference pitch angle, the reference infinity point correlation value, and the current infinity point correlation value. Perform estimation processing,
Headlight controller configured to. In the headlight control device according to claim 1,
The controller
A headlight control device configured to determine that the reference value acquisition condition is satisfied when the detected contraction length is included in a predetermined reference range. In the headlight control device according to claim 2.
The controller
A headlight control device in which the reference range is set to be included in a range from a minimum value to a maximum value of the contraction length acquired when the load of the vehicle is only a driver. In the headlight control device according to claim 1,
The controller
When the detected contraction length is smaller than the value obtained by subtracting a predetermined difference threshold value from the reference contraction length, it is determined that the reference value acquisition condition is satisfied.
When it is determined that the reference value acquisition condition is satisfied, the reference shrinkage length is updated so that the reference shrinkage length matches the detected shrinkage length.
Headlight controller configured to. In the headlight control device according to claim 4,
The controller
When the reference value acquisition process has not yet been executed, it seems that the reference shrinkage length is set to a value larger than the value obtained by adding the difference threshold value to the upper limit value of the range of values in which the shrinkage length is detected. Headlight control device configured in. In the headlight control device according to any one of claims 1 to 5.
The controller
In the pitch angle estimation process, the relationship that the difference between the tangent of the pitch angle at the present time and the tangent of the reference pitch angle is proportional to the difference between the reference infinity point correlation value and the point at infinity correlation value at the present time. To obtain the pitch angle based on
Headlight controller configured to. In the headlight control device according to any one of claims 1 to 5.
The controller
In the pitch angle estimation process, the difference between the current pitch angle and the reference pitch angle is proportional to the difference between the reference infinity point correlation value and the current point at infinity correlation value. Get the pitch angle,
Headlight controller configured to. In the headlight control device according to any one of claims 1 to 5.
The controller
In the point at infinity acquisition process, it is proportional to the difference between the point at infinity position, which is the point at infinity position acquired when the pitch angle is a predetermined specific angle, and the point at infinity position at the present time. The value to be used is obtained as the point at infinity correlation value.
In the reference value acquisition process, a value obtained by adding the reference pitch angle to the difference between the infinity point correlation value and the reference infinity point correlation value is acquired as the pitch angle.
Headlight controller configured to.

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