JP3095703B2 - Automatic adjustment of the headlight optical axis direction for vehicles - Google Patents

Abstract

PROBLEM TO BE SOLVED: To more quickly and properly adjust an optical axis direction of a headlight corresponding to a running condition of a vehicle. SOLUTION: In this device, based on a signal from a height sensor 11F, 11R arranged in a front/rear wheel of a vehicle, a pitch angle in a longitudinal direction of the vehicle is calculated. From a car speed and acceleration based thereon, a running condition of the vehicle is decided for whether in what control mode it is placed of stop, acceleration, deceleration, and fixed speed. Corresponding to this control mode, the pitch angle is filter processed, an actuator drive angle (target optical axis direction adjusting angle) without giving light of glare to a car in the opposite lane is actuated, an actuator 35R, 35L is driven, an optical axis direction of a headlight 30R, 30L is adjusted. Here, a change of acceleration which is a sign of a transfer to an acceleration/deceleration running condition of the vehicle is caught, by switching quickly to the corresponding control mode, the optical axis direction of the headlight 30R, 30L is more quickly and properly adjusted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicular headlamp automatic optical axis direction adjusting device for automatically adjusting the optical axis direction of irradiation by a headlamp provided in a vehicle.

[0002]

2. Description of the Related Art Conventionally, a headlight of a vehicle gives glare to an oncoming vehicle or the like when the optical axis of the headlight is directed upward due to the inclination of the vehicle body. There is a demand that the optical axis direction of the headlamp be kept constant because the visibility is reduced.

A related prior art document is disclosed in Japanese Utility Model Laid-Open No. 5-29857. In this technique, a technique is disclosed in which it is detected that the vehicle is stopped, and the optical axis direction of the headlight is adjusted based on a change in the vehicle height at that time.

[0004]

There is a further demand not only for stopping the vehicle as described above, but also for adjusting the optical axis direction of the headlight according to the behavior of the vehicle body during acceleration / deceleration. . In order to cope with such a demand, it is conceivable to switch the control mode in the optical axis control by detecting the acceleration of the vehicle. Here, when the control mode is switched in accordance with the vehicle acceleration, if the threshold value in the switching determination is set away from the fluctuation range of the acceleration, the switching of the control mode will be delayed. If the setting is made close to the fluctuation range, the control mode is frequently switched, and at the same time, there is a problem that inappropriate optical axis control appears.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and a vehicle headlight optical axis direction in which the optical axis direction of a headlight can be adjusted more promptly and appropriately according to the running state of the vehicle. The task is to provide an automatic adjustment device.

[0006]

According to the automatic headlight optical axis direction adjusting device for a vehicle according to the first aspect of the present invention, the tilt angle calculating means includes, for example, a vehicle disposed at each of a front portion and a rear portion of the vehicle. The inclination angle of the headlight of the vehicle with respect to the horizontal plane in the optical axis direction is calculated based on the output value from the high sensor, and the vehicle speed is detected from the vehicle speed detected by the wheel speed sensor and the acceleration calculated based on the calculated vehicle speed. According to the control mode determined by the mode determining means, the filter for changing the response of the adjustment of the headlight in the optical axis direction is switched by the filter switching means, and based on the angle obtained by applying the filter. The optical axis direction of the headlight is adjusted by the optical axis direction adjusting means. Here, when the acceleration has exceeded a lower predetermined level among a plurality of determination levels for a predetermined period, or when the acceleration has exceeded the highest level, the mode determining means determines whether the vehicle has transitioned to the acceleration state or the deceleration state. And the control mode is switched to the corresponding control mode. As described above, the filter corresponding to the traveling state of the vehicle is applied to the inclination angle, so that the optical axis direction of the headlight is adjusted with appropriate responsiveness.
At this time, if there is a sign of a transition of the running state of the vehicle to the acceleration state or the deceleration state, the corresponding filter is quickly applied to the inclination angle, and the optical axis direction of the headlight is more agile. Since the adjustment is performed, the effectiveness of the optical axis control can be enhanced.

In the vehicle headlamp automatic optical axis direction adjusting device according to the second aspect, the optical axis direction adjusting means includes an optical axis direction correcting means, and the vehicle speed at that time and the distance to the vehicle ahead are taken into consideration. Since the initially set optical axis direction of the headlight is corrected, the driver's distant visibility during high-speed driving is improved, and the distance to the preceding vehicle (including oncoming vehicles) is reduced during high-speed driving. In some cases, the direction of the optical axis of the headlight can be improved.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on examples.

FIG. 1 is a schematic diagram showing the overall configuration of a vehicle headlight optical axis direction automatic adjusting apparatus according to an embodiment of the present invention.

In FIG. 1, a suspension between a vehicle axle on the driver's seat side or a passenger's seat side on the front and rear sides of the vehicle and a front (front wheel) side height sensor (vehicle height sensor) 11F and a rear (rear). A height sensor (vehicle height sensor) 11R on the rear wheel side is mounted. From the height sensors 11F and 11R, a front height value (a displacement amount of the front wheel side vehicle height) HF and a rear height value as a relative displacement amount (a displacement amount of the front wheel side) between the front wheel side axle and the rear wheel side axle and the vehicle body. Value (amount of displacement of the vehicle height on the rear wheel side) HR, and a well-known ABS (Antilock Brak) provided on the vehicle side as a vehicle speed sensor.
e System) ECU (Electronic Control Unit: electronic control unit) 20 in which various sensor signals such as wheel speed pulses are output from wheel speed sensors 12 used in control and the like.
Is input to The ECU 20 and the wheel speed sensor 12
Are shown outside the vehicle for convenience.

The ECU 20 includes a CPU 21 as a well-known central processing unit, a ROM 22 storing a control program,
It is configured as a logical operation circuit including a RAM 23 for storing various data, a B / U (backup) RAM 24, an input / output circuit 25, and a bus line 26 connecting them.

An output signal from the ECU 20 is input to actuators 35L, 35R of left and right headlights (headlights) 30L, 30R of the vehicle, and the optical axes of the left and right headlights 30L, 30R are described later. The direction is adjusted. Note that various sensor signals from the wheel speed sensor 12 and the like are output in a constant speed mode, a stop mode, an acceleration mode,
Used for mode determination such as deceleration mode.

FIG. 2 shows a headlight 30L (30) shown in FIG.
It is sectional drawing which shows the principal part structure of R). 2, a headlight 30L (30R) mainly includes a lamp 31, a reflector 32 for fixing the lamp 31, a rod-shaped support portion 33 for supporting the reflector 32 so as to be swingable in the direction of an arc arrow, and a reflector 32. The other rod-shaped movable portion 34 that supports and is movable, and a step motor or D that drives the movable portion 34 in the forward and rearward arrow directions.
It is constituted by an actuator 35L (35R) composed of a C motor or the like. For this reason, when the movable portion 34 is driven in the front-rear direction by the actuator 35L (35R), the reflector 32 is vertically moved with the tip of the support portion 33 as a fulcrum, and an actuator drive angle (target optical axis direction adjustment angle) θa described later. Tilted, headlight 30L (30R)
Is adjusted in the optical axis direction. In addition, headlight 30L
The optical axis direction of (30R) is initially set on the assumption that one driver has boarded.

Next, the pitch angle θp in the front-rear direction of the vehicle used in the vehicle headlight optical axis direction automatic adjusting device of this embodiment.
The calculation of is described.

The pitch as an inclination angle with respect to a predetermined reference plane in the front-rear direction of the vehicle based on the front height value HF and the rear height value HR from the height sensors 11F and 11R among the various sensor signals of the vehicle input into the ECU 20. The angle θp [°] is calculated by the following equation (1). Here, Lw is the wheelbase (inter-axis distance) of the front wheel and the rear wheel.

[0016]

[Equation 1] θp = tan ⁻¹ {(HF−HR) / Lw} (1) FIG. 3 shows a vehicle headlight optical axis direction automatic adjusting apparatus according to an embodiment of the present invention. 9 is a table showing a filter area corresponding to a control mode used.

When the horizontal axis is the vehicle speed V [km / h] and the vertical axis is the acceleration dV / dt [m / s ² ] obtained by differentiating the vehicle speed V, the vehicle control modes (stop mode, acceleration mode, deceleration) Mode, constant speed mode).
B and C are shown. Examples of these filters include those using hardware (for example, signal smoothing by a CR circuit) for the height sensor signal and software (for example, ECU for the height sensor signal or pitch angle).
, And a smoothing of the signal using the standard deviation). In this system, since the ECU is originally built in, the moving average for the pitch angle which is advantageous in cost is used.

In the table of FIG. 3, when the vehicle speed V is less than several km / h (for example, 2 [km / h]), the filter A corresponding to the stop mode is set. Since a large pitch angle variation is expected, no filter is applied, or a very weak filter is applied so that the actuator responds quickly to the pitch angle variation.

On the other hand, when the vehicle speed V is several km / h (for example, 2 km / h)
[Km / h]) or more and the acceleration dV / dt calculated by differentiating the vehicle speed V exceeds a predetermined threshold (for example, ± 2 [m / s ² ]). Alternatively, a filter B corresponding to the deceleration mode is used, and since the pitch angle fluctuation is large, no filter is applied, or a very weak filter is used to make the actuator respond quickly to the pitch angle fluctuation. As will be described later, in the present embodiment, the vehicle is, for example, in a constant speed running state and the vehicle speed V is several km / h (for example, 2 [km / h]) or more. Calculated acceleration dV / d
t is a preset threshold value (for example, ± 1 [m / s ² ])
For a predetermined period (for example, twice the sampling period)
If the vehicle continuously exceeds the threshold, it is determined that the filter B is ready for the transition to the acceleration / deceleration running state, and the filter B is quickly set to the acceleration mode or the deceleration mode.

The vehicle speed V is several km / h (for example, 2 km / h).
[Km / h]) or more and the acceleration dV / dt calculated by differentiating the vehicle speed V is smaller than a preset threshold (for example, ± 2 [m / s ² ]), the constant speed mode is set. It is assumed that there is no large pitch angle fluctuation, and it is assumed that the actuator does not respond by applying a strong filter so as to remove a high frequency component of vibration during traveling and a pitch angle fluctuation due to unevenness of a road surface. Is what you do.

Next, FIG. 4 is a flowchart showing a processing procedure of the optical axis control of the CPU 21 in the ECU 20 used in the automatic headlight optical axis direction adjusting device for a vehicle according to one embodiment of the present invention. The description will be made with reference to the time charts of FIGS. This routine is executed approximately every 50 ms.

In FIG. 4, after the initial setting is performed in step S101, the process proceeds to step S102, where various sensor signals such as a wheel speed pulse, a front height value HF, and a rear height value HR are read. Next, step S103
Then, it is determined whether the vehicle speed V calculated from the wheel speed pulse read in step S102 is less than a preset threshold V0. It should be noted that as the threshold value V0, FIG.
Is 2 km / h, for example. When the determination condition in step S103 is satisfied, a timer TB described later is cleared to "0" in step S104, and then the process proceeds to step S105, where the pitch angle θp calculated by the above equation (1) is determined as the stop mode. On the other hand, a weak filter A shown in FIG. 3 is applied. As described above, the filtered pitch angle θpf obtained by applying the weak filter A to the pitch angle θp follows the transition state of the actual pitch angle θp to some extent.

On the other hand, when the determination condition in step S103 is not satisfied and the vehicle speed V is 2 [km / h] or more, the process proceeds to step S106, and the absolute value of the acceleration dV / dt obtained by differentiating the vehicle speed V is determined in advance. It is determined whether it is equal to or less than the set threshold value α1. The threshold value α1 is, for example, ± 1 [m / s ² ] as shown in the table of FIG. At this time, if the absolute value of the acceleration dV / dt exceeds the threshold value α1, the process moves to step S107, and the acceleration dV / dt
It is determined whether the absolute value of dt is equal to or smaller than the threshold value α2. The threshold value α2 is, for example, ± 2 [m / s ² ] as shown in the table of FIG. At this time, the acceleration d
If the absolute value of V / dt is equal to or smaller than the threshold value α2, the process proceeds to step S in order to determine whether it is a sign of shifting to the acceleration / deceleration running state.
At 108, the time .DELTA.T as a sampling period is added to the timer TB for measuring the time when the absolute value of the acceleration dV / dt continuously exceeds the threshold value .alpha.1 and is equal to or less than the threshold value .alpha.2. In this embodiment, the predetermined time is measured as the predetermined period, but the number of times when the absolute value of the acceleration dV / dt continuously exceeds the threshold value α1 and is equal to or less than the threshold value α2 may be counted.

Next, the flow shifts to step S109, where it is determined whether or not the count time of the timer TB exceeds a predetermined time T0. At this time, if the count time of the timer TB exceeds the time T0, the process shifts to step S110 to determine that the mode is the acceleration / deceleration mode (acceleration mode or deceleration mode) with respect to the pitch angle θp calculated by the above equation (1). The weak filter B shown in FIG. 3 is applied. in this way,
The weak filter B is applied to the pitch angle θp and the filtered pitch angle θpf follows the transition state of the actual pitch angle θp to some extent, as in the stop mode.

On the other hand, when the determination condition of step S107 is not satisfied and the absolute value of the acceleration dV / dt exceeds the threshold value α2, steps S108 and S109 are skipped, and the process shifts to step S110 to immediately proceed to the acceleration / deceleration mode. (Acceleration mode or deceleration mode), a weak filter B shown in FIG. 3 is applied to the pitch angle θp calculated by the above equation (1). In this way, the filtered pitch angle θpf obtained by applying the weak filter B to the pitch angle θp and following the transition state of the actual pitch angle θp to some extent, as in the stop mode.

Here, in the above-described control mode switching determination in steps S106 and S107,
Two-step threshold values α1, α for the absolute value of acceleration dV / dt
2 will be described with reference to time charts in FIGS. 5 and 6.

In the control mode switching determination, as shown in FIG. 5, the threshold value for the absolute value of the acceleration dV / dt is:
Assuming that it is one stage of ± 2 [m / s ² ], when the threshold value is exceeded, the control mode is switched from the constant speed mode corresponding to the constant speed traveling of the vehicle to the deceleration mode corresponding to the decelerating traveling of the vehicle. It will be. On the other hand, as can be seen from FIG. 6, when the vehicle shifts from the constant speed running to the decelerating running, the acceleration dV / dt temporarily increases to a certain extent, and then changes further. Paying attention to the transition state of the acceleration dV / dt when the running state of the vehicle is switched, as shown in FIG. 6, the threshold values for the absolute value of the acceleration dV / dt are set to ± 1 [m / s ² ], ± 2 [M /
s ² ]. Thereby, acceleration dV / dt
When the absolute value exceeds the threshold value ± 1 [m / s ² ] and this state continues for a predetermined time, it is a sign that the vehicle will shift to the acceleration / deceleration running state, and as shown in FIG.
At an early stage before the absolute value of dt exceeds the threshold value ± 2 [m / s ² ], the control mode is switched from the constant speed mode to the deceleration mode.

On the other hand, if the determination condition of step S106 is satisfied and the absolute value of the acceleration dV / dt is equal to or smaller than the threshold value α1, the vehicle is considered to be traveling at a constant speed. After clearing to "0", the process proceeds to step S112. Here, step S10
If the determination condition of No. 9 is not satisfied and the count time of the timer TB does not exceed the time T0, it is determined that the vehicle is not a sign of shifting to the acceleration / deceleration running state, and the process proceeds to step S112.
Move to In step S112, a strong filter C shown in FIG. 3 is applied to the pitch angle θp calculated by the above equation (1) assuming the constant speed mode. In this manner, the filtered pitch angle θpf obtained by applying the strong filter C to the pitch angle θp is such that the high-frequency component of the vibration is removed from the transition state of the actual pitch angle θp and there is no fine fluctuation.

In this manner, for each pitch angle θpf filtered in the vehicle stop mode in step S105, the acceleration / deceleration mode of the vehicle in step S110, and the constant speed mode of the vehicle in step S112, θa ≒ −θpf
Then, the actuator drive angle (target optical axis direction adjustment angle) θa that does not give glare to the oncoming vehicle is calculated.
Next, the process proceeds to step S113, where the actuator 35L (35) is calculated based on the calculated actuator drive angle θa.
R) is driven and the optical axis direction of the headlight 30L (30R) is adjusted, and the process returns to step S102, and thereafter, the processing of steps S102 to S113 is repeatedly executed. The control speed setting and the like for the actuator 35L (35R) are omitted. Thereby, the optical axis direction of the headlight 30L (30R) is adjusted more promptly and appropriately in accordance with the running state of the vehicle (stop mode, acceleration / deceleration mode, constant speed mode).

As described above, the apparatus for automatically adjusting the direction of the optical axis of the vehicle headlamp according to the present embodiment includes a front part and a rear part of the vehicle.
A height sensor 11F, 11R disposed at a location for detecting a displacement amount of the vehicle height, and a headlight 30 of the vehicle based on output values HF, HR from the height sensors 11F, 11R.
An inclination angle calculating means, which is achieved by the ECU 20 for calculating a pitch angle θp as an inclination angle of the L, 30R with respect to the horizontal plane in the optical axis direction, and a vehicle speed sensor for detecting a vehicle speed V based on the left and right wheel speeds VL, VR of the vehicle. Wheel speed sensor 1 as
2, the vehicle speed V, and the acceleration d calculated based on the vehicle speed V
V / dt and a mode determination means which is achieved by the ECU 20 which determines a control mode corresponding to the running state, and adjustment of the headlights 30L and 30R in the optical axis direction corresponding to the control mode determined by the mode determination means. Filter switching means achieved by the ECU 20 for switching the filter for changing the responsiveness, and an angle obtained by applying the filter by the filter switching means to the pitch angle θp calculated by the inclination angle calculating means. Headlight 30 based on the actuator drive angle θa corresponding to the pitch angle θpf of
And an optical axis direction adjusting means which is achieved by the ECU 20 for adjusting the optical axis directions of the L and 30R, wherein the mode determining means includes a plurality of determination levels for determining a shift of the vehicle to an acceleration state or a deceleration state. And the absolute value of the acceleration dV / dt is determined by the two threshold values α1, α2.
When the lower threshold value α1 exceeds the predetermined threshold value T0 or when the upper threshold value α2 of the two threshold values α1 and α2 is exceeded, the acceleration mode or the deceleration mode corresponding to the acceleration state or the deceleration state of the vehicle is set. Things.

Therefore, E which achieves the inclination angle calculating means
At least one of the front part and the rear part of the vehicle
Based on output values HF, HR from height sensors 11F, 11R disposed at the locations, headlights 30L, 3
The ECU 20 calculates a pitch angle θp with respect to the horizontal plane in the direction of the optical axis of 0R, and achieves a mode determining means corresponding to the running state from the vehicle speed V detected by the wheel speed sensor 12 and the acceleration dV / dt calculated based on the vehicle speed V. ECU 2 that achieves filter switching means according to the control mode determined by
At 0, the filter for changing the response of the adjustment of the headlights 30L and 30R in the optical axis direction is switched, and the ECU 20 which achieves the optical axis direction adjusting means based on the pitch angle θpf obtained by applying the filter is used. 30L, 30
The optical axis direction of R is adjusted. Here, when the acceleration dV / dt exceeds the lower threshold value α1 for a predetermined time T0 or exceeds the upper threshold value α2, the ECU 20 that achieves the mode determination means determines whether the vehicle has shifted to the acceleration state or the deceleration state. , The control mode is switched to the corresponding control mode. Therefore, a filter corresponding to the running state of the vehicle is applied to the pitch angle θp, and the optical axis directions of the headlights 30L, 30R are adjusted with appropriate responsiveness. At this time, if there is a precursor to the transition of the running state of the vehicle to the acceleration state or the deceleration state, the corresponding filter is quickly applied to the pitch angle θp, and the headlights 30L, 30R
The direction of the optical axis is adjusted with more agile response, so that the effectiveness of the optical axis control can be enhanced.

Next, in the vehicle headlamp optical axis direction automatic adjusting apparatus according to one embodiment of the present invention, the optical axis target initially set by the optical axis control for the headlight 30L (30R) of the vehicle. The case where the optical axis target angle θo is corrected will be described with reference to FIG. 7 showing the angle θo.

As shown in FIG. 7, the initially set optical axis target angle θo of the headlight 30L (30R) of the vehicle is -1% with respect to the horizontal plane, ie, -tan ^-1 0.01 °-.
The inclination angle is 0.57 [°]. This means that when the mounting height H of the headlight 30L (30R) is, for example, 0.65 m, the light reaches 65 m ahead of the vehicle as the initial reach Lo.

[0034] Under the initial setting conditions, there is no inconvenience in ordinary urban driving.
At 0 km / h, it is said that a braking distance Ls of about 100 m before stopping is required, and it is desirable that the braking distance Ls be visible up to about 100 m in front of the vehicle. To address this demand, the vehicle headlight 30L (30
Optical axis target angle θo initially set by optical axis control for R)
Is corrected by the following equation (2). Here, a is set to 0 to 30 m, and when the corrected optical axis target angle θc becomes smaller than −0.57 °, θc =
It is fixed at -0.57 [°].

[0035]

Θc = −tan ⁻¹ {H / (Ls + a)} (2) By the way, the inter-vehicle distance L between the own vehicle and the preceding vehicle (including the oncoming vehicle)
When c [m] is equal to or less than (Ls + a) [m], it is not always necessary to extend the reach of light. So, for example,
When the inter-vehicle distance Lc can be measured by a radar or the like, the corrected optical axis target angle θc [°] obtained by correcting the initially set optical axis target angle θo in the optical axis control for the headlight 30L (30R) of the vehicle is expressed by the following equation. It may be calculated in (3). Here, when the correction optical axis target angle θc becomes smaller than −0.57 °, θc is fixed at −0.57 °.

[0036]

Θc = −tan ⁻¹ (H / Lc) (3) Next, the vehicle headlight 30L (30) shown in FIG.
Optical axis target angle θo initially set by optical axis control for R)
Will be described with reference to the flowchart of FIG. This routine is repeatedly executed at a predetermined interrupt timing.

In FIG. 8, in step S201, various sensor signals such as a radar signal from a radar (not shown) for measuring the wheel speed pulse and the inter-vehicle distance Lc are read. Next, the process proceeds to step S202, and step S20
The vehicle speed V [k calculated from the wheel speed pulse read in
m / h] is the mounting height H of the headlight 30L (30R).
It is determined whether or not a threshold value VH [km / h] set in relation to [m] is exceeded. That is, as described with reference to FIG. 7, the optical axis direction of the headlight 30L (30R) has an inclination angle of -1% with respect to the horizontal plane, and the mounting height H is 0.65.
m, the light reaches 65 m in front of the vehicle, so the threshold VH at this time is 65 km / h from the relationship with the braking distance Ls until the vehicle stops.

If the determination condition in step S202 is satisfied and the vehicle speed V exceeds the threshold value VH, the flow advances to step S203.
Move to In step S203, step S201
Distance Lc calculated from the radar signal read in
It is determined whether or not [m] exceeds a threshold value LH (= 100 × H) [m] set in relation to the mounting height H of the headlight 30L (30R). If the determination condition of step S203 is satisfied and the inter-vehicle distance Lc exceeds the threshold LH, the process proceeds to step S204. In step S204, the braking distance Ls or the inter-vehicle distance Lc corresponding to the vehicle speed V
Equation (2) or Equation (3) depending on at least one of
The initially set optical axis target angle θo is corrected by the smaller one of the corrected optical axis target angles θc calculated in the above, and the routine ends. Note that the correction optical axis target angle θc is -0.57 °
When smaller, θc is fixed at −0.57 °. Here, step S202 or step S2
When the determination condition of 03 is not satisfied, this routine ends without correcting the initially set optical axis target angle θo.

As described above, in the vehicle headlamp optical axis direction automatic adjusting device according to the present embodiment, the optical axis direction adjusting means achieved by the ECU 20 uses the braking distance Ls corresponding to the vehicle speed V at that time.
Alternatively, according to at least one of the following distances Lc as the distance to the vehicle in front, the headlight 30L (30
R) includes an optical axis direction correcting means for correcting the initially set optical axis target angle θo. That is, in the case where the ECU 20 for achieving the optical axis direction adjusting means includes the optical axis direction correcting means, the initially set optical axis target angle θo is corrected in consideration of the vehicle speed V and the inter-vehicle distance Lc at that time. Therefore, the driver's distant visibility during high-speed driving is improved, and the headlight 30L (30R) has a good optical axis direction even when the distance from the preceding vehicle (oncoming vehicle) is reduced during high-speed driving. Can be.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing the overall configuration of a vehicle headlight optical axis direction automatic adjustment device according to an example of an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a configuration of a main part of the headlight of FIG.

FIG. 3 is a table showing a filter area corresponding to a control mode used in a vehicle headlight optical axis direction automatic adjustment device according to an example of an embodiment of the present invention.

FIG. 4 is a flowchart showing a processing procedure of optical axis control in a CPU in an ECU used in the automatic headlight optical axis direction adjusting device for a vehicle according to one embodiment of the present invention. .

FIG. 5 is a time chart as a comparative example illustrating the effectiveness of the optical axis control by the vehicular headlamp automatic optical axis direction adjusting device according to one example of the embodiment of the present invention.

FIG. 6 is a time chart for explaining the effectiveness of the optical axis control by the vehicle headlamp automatic optical axis direction adjusting device according to one example of the embodiment of the present invention.

FIG. 7 is an explanatory diagram showing an optical axis target angle initially set by the vehicular headlamp optical axis direction automatic adjustment device according to one example of an embodiment of the present invention.

FIG. 8 shows a processing procedure of a correction calculation of an optical axis target angle in a CPU in an ECU used in an automatic headlight optical axis direction adjusting device for a vehicle according to an embodiment of the present invention. It is a flowchart shown.

[Explanation of symbols]

 11F, 11R Height sensor (vehicle height sensor) 12 Wheel speed sensor (vehicle speed sensor) 20 ECU (electronic control device) 30L, 30R Headlight (headlight) 35L, 35R Actuator

Continued on the front page (72) Inventor Ryoji Kawakami 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Ryosuke Naito 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Yuji Yamada 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Co., Ltd. (56) References JP-A-9-207654 (JP, A) JP-A-9-207653 (JP, A) JP-A-9 -301055 (JP, A) Japanese Utility Model Application Hei 5-29857 (JP, U) Japanese Utility Model Application Hei 6-72740 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) B60Q 1/115

Claims (2)

(57) [Claims] 1. A vehicle height sensor for detecting a displacement amount of a vehicle height of a vehicle, and a tilt angle for calculating a tilt angle of a headlight of the vehicle with respect to a horizontal plane in an optical axis direction based on an output value from the vehicle height sensor. Computing means; a vehicle speed sensor for detecting a vehicle speed of the vehicle; mode determining means for determining a control mode corresponding to a running state from the vehicle speed and acceleration calculated based on the vehicle speed; Filter switching means for switching a filter for changing the response of adjustment of the headlight in the optical axis direction in accordance with the control mode; and the filter switching means for the tilt angle calculated by the tilt angle calculation means. Optical axis direction adjusting means for adjusting the optical axis direction of the headlamp based on the angle obtained by applying the filter according to the above, wherein the mode determining means is in an acceleration state or a deceleration state of the vehicle. A plurality of judgment levels for judging a transition to a state, and when the acceleration exceeds a predetermined lower judgment level of the plurality of judgment levels for a predetermined period, or a highest judgment of the plurality of judgment levels. A vehicle headlight optical axis direction automatic adjustment device, wherein a control mode corresponding to an acceleration state or a deceleration state of the vehicle is set when a level is exceeded. 2. The optical axis direction adjusting means corrects an initially set optical axis direction of the headlight according to at least one of a vehicle speed at that time and a distance from a vehicle ahead. The apparatus for automatically adjusting the optical axis direction of a vehicle headlight according to claim 1, further comprising a direction correcting unit.