JP2000142213A - Device for automatically adjusting optical axis direction of head lamp for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To deal with various load conditions at the time of automatically adjusting an optical axis direction of vehicular headlights (head lamps) on the basis of an output from one height sensor. SOLUTION: A rear height value (a displacement amount of height in rear wheel side) is inputted from a height sensor arranged on a rear part of a vehicle to an ECU (an electronic control unit) 20. On the basis of the rear height value, a pitch angle to a horizontal surface in an optical axis direction of headlights 30 is calculated by a plurality of formulas for forecasting a vehicular posture corresponding to a vehicular type and corresponding to load conditions of an occupant load and a trunk load. Thus, the pitch angle corresponding to the load conditions of that time is calculated by the rear height value from one height sensor 11 in preparing a plurality of formulas for forecasting a vehicular posture corresponding to the load conditions beforehand. Accordingly, a necessary adjusting angle for a target optical axis direction can be calculated from the pitch angle to appropriately adjust the optical axis direction of the headlights 30.

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 when the optical axis of the headlight is directed upward due to the inclination of the vehicle body, or a driver's distant light when the optical axis is directed downward. There is a demand that the optical axis direction of the headlamp be kept constant because the visibility is reduced.

[0003]

By the way, there is known an optical axis control using an inclination angle obtained by approximating a change amount of a vehicle attitude due to a load by a linear expression. In this case, under limited load conditions such as "only the occupant load" or "up to the occupant load and trunk load of 50 kg", it is possible to make the optical axis direction of the headlight coincide with the vehicle posture. However, the above-described vehicle has a problem that it cannot cope with various load conditions due to a combination of the occupant load and the trunk load.

Accordingly, the present invention has been made to solve such a problem, and an object of the present invention is to provide a simple system and an inexpensive automatic headlight optical axis direction adjusting device for a vehicle. It is an object of the present invention to provide a vehicle headlight optical axis direction automatic adjustment device capable of coping with various load conditions when automatically adjusting the optical axis direction based on an output from one vehicle height sensor.

[0005]

According to the automatic headlight optical axis direction adjusting device of the first aspect, the inclination angle calculating means adjusts the light axis direction of the headlight based on the output from one vehicle height sensor. The inclination angle with respect to the horizontal plane is calculated using a prediction formula divided into a plurality of vehicle postures having different inclinations corresponding to the load conditions of the occupant load and the trunk load, and based on the inclination angle, the headlight is adjusted by the optical axis direction adjusting means. Is adjusted in the optical axis direction. Therefore, for example, an output value from one vehicle height sensor is detected by preparing in advance a plurality of vehicle posture prediction formulas corresponding to the load conditions of the occupant load and the trunk load corresponding to the vehicle type and the like. Then, the tilt angle corresponding to the load condition at that time is calculated, and the required target optical axis direction adjustment angle can be calculated from the tilt angle, and the optical axis direction of the headlamp is appropriate according to the load condition at that time. Is obtained.

According to a second aspect of the present invention, there is provided a vehicle headlight optical axis direction automatic adjusting apparatus, wherein a load at that time is obtained from a plurality of prediction formulas divided into a plurality of vehicle postures corresponding to sensor outputs other than a vehicle height sensor by an inclination angle calculating means. The prediction formula corresponding to the condition is selected. Therefore, an effect is obtained that more appropriate adjustment control in the optical axis direction can be performed in response to a change in a complicated load condition at that time in addition to the vehicle type and the like.

According to a third aspect of the present invention, there is provided a vehicle headlight optical axis direction automatic adjusting device, wherein the output from one vehicle height sensor by the inclination angle calculating means and the vehicle height sensor stored in the storage means as system error information are attached. The angle of inclination of the headlight with respect to the horizontal plane in the optical axis direction depends on the load conditions of the occupant load and the trunk load. It is calculated using the divided prediction formula, and the optical axis direction of the headlight is adjusted by the optical axis direction adjusting means based on the inclination angle. For this reason, for example, a plurality of vehicle posture prediction formulas corresponding to the load conditions of the occupant load and the trunk load corresponding to the vehicle type and optional equipment are prepared in advance, and the output detected by one vehicle height sensor is prepared. By adding the system error information to the value, the tilt angle corresponding to the load condition at that time is calculated, and the required target optical axis direction adjustment angle can be calculated from the tilt angle, and the optical axis direction of the headlight can be calculated. The effect is obtained that the adjustment is appropriately made according to the load condition at that time.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on examples. <Embodiment 1> FIG. 1 is a schematic view showing the entire configuration of a vehicle headlight optical axis direction automatic adjusting apparatus according to a first embodiment of the present invention.

In FIG. 1, a vehicle height sensor 11 is mounted on the axle on the driver's seat side or the passenger's seat side at the rear of the vehicle. From this vehicle height sensor 11, a rear vehicle height value (a rear wheel side vehicle height displacement amount) as a relative displacement amount (a vehicle height displacement amount) between the rear wheel axle and the vehicle body is referred to as a "rear vehicle height measured value". ), An ECU (Electronic Control U) in which various sensor signals from HR and other sensors (not shown) are mounted on the vehicle.
nit: electronic control unit) 20. In addition,
The ECU 20 is 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. The output signal from the ECU 20 is input to an actuator 35 on the headlight (headlight) 30 side of the vehicle, and the optical axis direction of the headlight 30 is adjusted as described later.

FIG. 2 is a cross-sectional view showing the structure of a main part of the headlight 30 of FIG.

In FIG. 2, a headlight 30 mainly supports a lamp 31, a reflector 32 for fixing the lamp 31, one 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 movable part 34 which is movable together with the movable part 34
Is constituted by an actuator 35 composed of a step motor or the like for driving the motor in the directions of front and rear arrows. Note that the optical axis direction of the headlight 30 is initially set assuming a state in which one driver gets on the vehicle.

Next, the CPU 21 in the ECU 20 used in the vehicle headlamp automatic optical axis direction adjusting apparatus according to the first embodiment of the present invention copes with various load conditions in the optical axis direction. A description will be given based on a flowchart of FIG. 3 showing a processing procedure of the adjustment control. Note that this control routine is repeatedly executed by the CPU 21 at predetermined time intervals. When the control routine of FIG. 3 is executed, it is determined in advance which of the prediction formulas of FIG. 4, FIG. 5 or FIG. 6 to use in accordance with the vehicle type. Necessary tables are stored in the ROM 22 in advance.

Here, FIG. 4 is a prediction formula obtained by dividing the two vehicle postures by a polygonal line connecting linear expressions having different inclinations corresponding to the load conditions for calculating the pitch angle [°] based on the rear vehicle height value [mm]. This table is for sedan type and wagon type where the trunk load is applied to the rear side of the rear suspension. FIG. 5 shows the rear vehicle height [m
m] is a table showing a modified example of a prediction formula divided into two vehicle postures by a polygonal line connecting linear formulas having different inclinations corresponding to load conditions for calculating a pitch angle [°] based on a load condition. Compatible with 1BOX type and mini cars on suspension. FIG. 6 is a table showing a prediction formula divided into two vehicle postures by a polygonal line connecting linear expressions having different inclinations corresponding to the load conditions for calculating the pitch angle [°] based on the front vehicle height value [mm]. Yes,
It is compatible with midship vehicles and RR (rear engine / rear drive) vehicles with a trunk load applied to the front suspension. In the present embodiment, it is assumed that the table of FIG. 4 corresponding to the sedan type is stored in the ROM 22 in advance.

In FIG. 3, a rear vehicle height value (rear vehicle height measurement value) HR from the vehicle height sensor 11 is read in step S101. Next, the process proceeds to step S102, where the rear vehicle height value HR read in step S101 is the rear vehicle height value ha (= -9 [mm]) that separates the occupant load region and the trunk load region indicated by the broken line in FIG. It is determined whether this is the case. When the determination condition in step S102 is satisfied, that is, when the rear vehicle height value HR is as large as the rear vehicle height value ha or more and is in the occupant load region (the region surrounded by oblique lines on the right side in FIG. 4), the process proceeds to step S103 and the two vehicles Rear vehicle height value HR read in step S101 of the prediction formula divided into postures
The pitch angle θ is obtained from one of the prediction formulas f0 (HR) into which
p is calculated.

On the other hand, when the determination condition of step S102 is not satisfied, that is, when the rear vehicle height HR is smaller than the rear vehicle height ha and is in the trunk load region (the region not surrounded by the oblique line on the left side in FIG. 4), the step is performed. Move to S104,
The pitch angle θp is calculated by the other prediction formula f1 (HR) into which the rear vehicle height value HR read in step S101 is substituted. At this time, in FIG. 4, in the conventional prediction formula indicated by the one-dot chain line in the trunk load region obtained by extending the solid line indicating the prediction formula of the occupant load region, the actual load condition greatly deviates from the symbol “black diamond”. However, the solid line in which the inclination is changed in the trunk load region shown as the present invention substantially matches the actual load condition. The symbol “black diamond” shown in FIG. 4 is an actually measured value based on the load condition when the occupant is in the occupant state in all the seats, and the symbol “white square” is the occupant occupying state in the driver seat.

Step S103 or step S104
After the pitch angle θp is calculated in step S105, the process proceeds to step S105, where the target optical axis direction adjustment angle θT (≒ −θp) that does not give glare to oncoming vehicles with respect to the pitch angle θp is calculated. Next, the process proceeds to step S106, and step S1
The actuator 35 is driven based on the target optical axis direction adjustment angle θT calculated in 05, and the routine ends.
The setting of the control speed for the actuator 35 and the like are omitted.

As described above, the apparatus for automatically adjusting the optical axis direction of the vehicle headlamp according to the present embodiment is provided at the rear portion of the vehicle and has one vehicle height sensor 11 for detecting the amount of displacement of the vehicle height, and the vehicle height sensor. 1
Based on the rear vehicle height value HR, which is an output from No. 1, the slope differs depending on the load conditions of the occupant load determined by the occupant riding state in the vehicle interior and the trunk load determined by the luggage loading state in the vehicle trunk. The CPU 21 in the ECU 20 calculates a pitch angle θp corresponding to the inclination angle of the headlight (headlight) 30 of the vehicle with respect to the horizontal plane in the optical axis direction using a prediction formula divided into two (plural) vehicle attitudes. EC for adjusting the optical axis direction of the headlight 30 by the achieved tilt angle calculating means and the target optical axis direction adjusting angle θT based on the pitch angle θp calculated by the tilt angle calculating means.
And an optical axis direction adjusting means achieved by the CPU 21 in the U20.

Therefore, the rear vehicle height value HR, which is an output from one vehicle height sensor 11 by the CPU 21 in the ECU 20, is provided.
The pitch angle θp corresponding to the inclination angle of the headlight 30 with respect to the horizontal plane in the optical axis direction according to the load conditions of the occupant load and the trunk load at that time, and is divided into two vehicle postures having different inclinations, HR) and f1 (HR), and the headlight 3 is calculated based on the pitch angle θp.
The optical axis direction of 0 is adjusted. For this reason, for example, by preparing beforehand a prediction formula that is divided into two vehicle postures having different inclinations corresponding to the load conditions of the occupant load and the trunk load in accordance with the vehicle type, etc. Is detected, the pitch angle θp corresponding to the load condition at that time is calculated, and the required target optical axis direction adjustment angle θT can be calculated from the pitch angle θp, and the optical axis direction of the headlight 30 can be calculated. Is appropriately adjusted according to the load condition at that time.

Next, the CPU 21 in the ECU 20 used in the vehicle headlamp automatic optical axis direction adjusting apparatus according to the first embodiment of the present invention copes with various load conditions in the optical axis direction. In the process of the adjustment control, 2 shown in FIG.
A case will be described in which a table having three prediction formulas divided into two vehicle attitudes corresponding to sensor outputs other than the vehicle height sensor 11 is used.

FIG. 7 shows a vehicle type corresponding to a sedan type or a wagon type in which a trunk load is applied to a rear side of a rear suspension as in the case of FIG. 4, and two vehicle postures selected based on other sensor signals. A table having three prediction formulas A, B, and C corresponding to sensor outputs other than the vehicle height sensor is shown. Here, the other sensor signals include a passenger seat sensor (not shown) provided in the front passenger seat of the vehicle and detecting entry to the front passenger seat, a load sensor (not shown) for measuring a trunk load, and a known G (acceleration) This is a sensor signal from the sensor. That is, the ECU 2 stores a table having three prediction formulas corresponding to vehicle types and divided into two vehicle attitudes.
0 is stored in advance in the ROM 22, and the pitch angle θp can be calculated by selecting and switching the prediction formula according to a change in a complicated actual load condition, so that a more accurate vehicle attitude can be predicted, and a more appropriate The adjustment control in the optical axis direction can be performed.

As described above, in the vehicle headlight optical axis direction automatic adjusting apparatus of the present modification, the inclination angle calculating means achieved by the CPU 21 of the ECU 20 divides the prediction formula into two (plural) vehicle attitudes. It has three (plural) corresponding to sensor outputs other than the vehicle height sensor 11 provided in the vehicle, and selects one according to the sensor output other than the vehicle height sensor 11. Therefore, a prediction formula corresponding to the load condition at that time can be selected from three prediction formulas corresponding to the vehicle type and the like and divided into two vehicle postures. For this reason, more appropriate adjustment control in the optical axis direction can be performed in response to a change in a complicated load condition at that time in addition to the vehicle type and the like. <Embodiment 2> FIG. 8 is a schematic diagram showing the overall configuration of a vehicle headlamp optical axis direction automatic adjusting apparatus according to a second embodiment of the present invention.

Referring to FIG. 8, FIG.
The difference from the schematic configuration diagram of FIG. 1 is that a rewritable nonvolatile memory such as an EEPROM 29 is provided as a storage medium for storing system error information in advance.
It is only that it is built in the CU 20. EE
The PROM 29 may be connected to the outside of the ECU 20. Therefore, the other components are denoted by the same reference numerals and symbols, and detailed description thereof will be omitted. The configuration of the main part of the headlight is also the same as the cross-sectional view of FIG. Here, the system error information includes an error in mounting the vehicle height sensor 11 to the vehicle, an error in the spring constant of the front and rear suspensions, an error in weight due to a difference in specifications of the vehicle, an error in the position of the center of gravity, and the like. It is a factor that affects the calculation.

Next, various load conditions are considered in consideration of system error information in the CPU 21 in the ECU 20 used in the vehicle headlamp automatic optical axis direction adjusting device according to the second embodiment of the present invention. A description will be given with reference to FIGS. 10, 11 and 12 based on the flowchart of FIG. 9 showing the processing procedure of the adjustment control in the optical axis direction to be dealt with. Note that this control routine is repeatedly executed by the CPU 21 at predetermined time intervals.

Here, FIG. 10 shows a prediction formula (thin solid line) before the system error information corresponding to the characteristics of the standard vehicle is considered, and a rear vehicle height value conversion based on the mounting error of the vehicle height sensor 11 to the vehicle. It is a table which shows the prediction formula (thick solid line) which considered the system error information at the time of -20 [mm] shift. FIG. 11 shows a prediction formula (thin solid line) before the system error information corresponding to the characteristics of the standard vehicle is considered, and a system when the inclination of the prediction formula changes due to an error in the spring constant of the front and rear suspensions. 9 is a table showing a prediction formula (thick solid line) in which error information is considered. FIG. 12 is a table showing five prediction formulas in which system error information including various errors based on mounting errors of the vehicle height sensor 11 to the vehicle and other factors of the vehicle is considered. In the tables shown in FIGS. 10, 11 and 12, the symbols “black diamond” are measured values when all the seats are in the occupant state, and the “square white” symbols are measured values based on the load conditions when the driver is in the occupant state. The prediction formula corresponding to the standard vehicle characteristics is stored in the ROM 22 in advance.

In FIG. 9, in step S201, a rear vehicle height value (rear vehicle height measurement value) HR from the vehicle height sensor 11 is read. Next, the process proceeds to step S202, where the system error information is read. Next, the process proceeds to step S203, and the rear vehicle height value HR read in step S201.
Is updated to (α * HR−Δh) with the correction gain α and the correction amount (offset amount) Δh based on the system error information read in step S202.

Here, as shown in FIG. 10 as a prediction expression before the system error information is considered by a thin solid line, the rear vehicle height value HR is simply determined by the mounting error of the vehicle height sensor 11.
When they are simply shifted by -20 [mm] in conversion, as shown by a thick solid line in FIG. 10 as a prediction formula in which the system error information is taken into account, the error (correction amount Δ
The correction of h) substantially matches the actual load conditions indicated by the symbols “black diamond” and “square white”.
Further, as shown in FIG. 11 as a prediction equation before the system error information is considered by a thin solid line, the inclination of the prediction equation is changed due to an error in mounting the vehicle height sensor 11 and an error in the spring constant of the front and rear suspensions. Figure 1
As shown by a thick solid line in FIG. 1 as a prediction formula in which the system error information is taken into account, the error (correction gain α and correction amount Δh) is corrected, so that the “rhombic black” symbol and the “square white” This is almost the same as the actual load condition indicated by the symbol.

Next, the process proceeds to step S204, and the rear vehicle height value HR updated in step S203 further shows the value shown in FIG.
It is determined whether or not the rear vehicle height value ha (= -9 [mm]) that separates the occupant load region and the trunk load region indicated by the broken line in FIG. When the determination condition of step S204 is satisfied, that is, when the rear vehicle height value HR is as large as the rear vehicle height value ha or more and is in the occupant load region (the region surrounded by oblique lines on the right side in FIG. 12), the process proceeds to step S205 and the two vehicles Five prediction formulas fx (HR), divided into postures, (i = 1, 2,...,
5), the rear vehicle height value HR updated in step S203 is substituted for the prediction formula, and the pitch angle θp is calculated.

On the other hand, when the determination condition of step S204 is not satisfied, that is, when the rear vehicle height value HR is smaller than the rear vehicle height value ha and is in the trunk load region (region not surrounded by the oblique line on the left side of FIG. 12), step S204 is performed. The process proceeds to S206, and the five prediction formulas fyi (H
R), (i = 1, 2,..., 5), the rear vehicle height value HR updated in step S203 is substituted for the prediction formula, and the pitch angle θp is calculated. At this time, in FIG. 12, in the prediction formula selected in consideration of the system error information, the actual load condition substantially coincides with the symbol “black diamond” and the symbol “white square”.

Step S205 or S206
After the pitch angle θp is calculated in step S207, the process proceeds to step S207, and a target optical axis direction adjustment angle θT (≒ −θp) that does not give glare to oncoming vehicles with respect to the pitch angle θp is calculated. Next, the process proceeds to step S208, and step S2
The actuator 35 is driven based on the target optical axis direction adjustment angle θT calculated in step 07, and this routine ends.
The setting of the control speed for the actuator 35 and the like are omitted.

As described above, the vehicle headlamp optical axis direction automatic adjusting device of the present embodiment is disposed at the rear of the vehicle, and detects one vehicle height sensor 11 for detecting the amount of vehicle height displacement, and the vehicle height sensor. 1
1 is stored in an EEPROM 29 as storage means for storing in advance system errors and various errors based on other factors of the vehicle and other factors based on other factors of the vehicle, and a rear vehicle height value HR and an EEPROM 29 output from the vehicle height sensor 11. (Two or more) having different inclinations corresponding to the load conditions of the occupant load determined by the occupant riding state in the vehicle interior and the trunk load determined by the luggage loading state in the vehicle trunk based on the system error information obtained. Pitch angle θp corresponding to the inclination angle of the headlight (headlight) 30 of the vehicle with respect to the horizontal plane in the optical axis direction using a prediction formula divided into vehicle postures
The optical axis direction of the headlight 30 is adjusted by a tilt angle calculating means achieved by the CPU 21 in the ECU 20 and a target optical axis direction adjusting angle θT based on the pitch angle θp calculated by the tilt angle calculating means. CP in ECU 20
And an optical axis direction adjusting means achieved in U21.

Therefore, the rear vehicle height value HR, which is an output from one vehicle height sensor 11 by the CPU 21 in the ECU 20, is provided.
The pitch angle θp corresponding to the inclination angle of the headlight 30 with respect to the horizontal plane in the optical axis direction based on the system error information stored in the EEPROM 29 and the inclination differs according to the load conditions of the occupant load and the trunk load at that time. It is calculated using the prediction formulas fxi (HR) and fyi (HR) divided into two vehicle attitudes, and the optical axis direction of the headlight 30 is adjusted based on the pitch angle θp. For this reason, for example, a prediction formula divided into two vehicle postures having different inclinations corresponding to the load conditions of the occupant load and the trunk load in accordance with the vehicle type and the like is prepared in advance, and a prediction formula from one vehicle height sensor 11 is provided. By adding the system error information to the rear vehicle height HR, the pitch angle θp corresponding to the load condition at that time is calculated,
From the pitch angle θp, the required target optical axis direction adjustment angle θT
Can be calculated, and the optical axis direction of the headlight 30 is appropriately adjusted according to the load condition at that time.

In the above embodiment, a table divided into two regions, ie, an occupant load region and a trunk load region, is used as a prediction formula divided into a plurality of vehicle postures corresponding to the load conditions. The present invention is not limited to this. If the vehicle attitude differs depending on the load position even in the same occupant load area and trunk load area, the table is further subdivided and divided into three or more areas. It may be. In addition, the prediction formula is a polygonal line connecting linear expressions having different inclinations corresponding to the load conditions,
Arbitrary functions such as higher-order expressions and exponential functions can be used. At this time, even if the prediction equation is a high-order equation, the area may be divided into a large number for approximation of the program, and each area may be approximated by a linear equation. Further, in a vehicle type in which the pitch angle θp does not change even when the rear vehicle height value HR changes, the prediction formula may be a constant (0th order formula).

In the above embodiment, the pitch angle θp is calculated from the rear vehicle height HR by using a prediction formula table divided into a plurality of vehicle attitudes. For example, the front vehicle height is estimated from the rear vehicle height. Then, the pitch angle may be calculated.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an overall configuration of a vehicle headlamp optical axis direction automatic adjustment device according to a first 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 an optical axis direction for coping with various load conditions in a CPU in an ECU used in a vehicle headlight optical axis direction automatic adjustment device according to a first example of an embodiment of the present invention; 5 is a flowchart showing a procedure of the adjustment control of FIG.

FIG. 4 is divided into two vehicle postures for calculating a pitch angle based on a rear vehicle height value used in a vehicle headlight optical axis direction automatic adjustment device according to a first example of an embodiment of the present invention. It is a table which shows a prediction formula.

FIG. 5 is a view showing another two vehicle postures for calculating a pitch angle based on a rear vehicle height value used in a vehicle headlight optical axis direction automatic adjustment device according to a first example of an embodiment of the present invention; It is a table which shows the divided prediction formula.

FIG. 6 is divided into two vehicle attitudes for calculating a pitch angle based on a front vehicle height value used in the vehicle headlight optical axis direction automatic adjustment device according to the first example of the embodiment of the present invention. It is a table which shows a prediction formula.

FIG. 7 is a diagram showing two examples of calculating a pitch angle based on a rear vehicle height value and other sensor outputs used in a vehicle headlight optical axis direction automatic adjustment device according to a first example of an embodiment of the present invention. 6 is a table showing three prediction formulas classified into vehicle postures corresponding to sensor outputs other than the vehicle height sensor.

FIG. 8 is a schematic diagram showing the entire configuration of a vehicle headlight optical axis direction automatic adjustment device according to a second example of an embodiment of the present invention.

FIG. 9 is a view showing various load conditions in consideration of system error information in a CPU in an ECU used in an automatic headlight optical axis direction adjusting device for a vehicle according to a second embodiment of the present invention; 6 is a flowchart showing a processing procedure of adjustment control in the optical axis direction to cope with the above.

FIG. 10 is a diagram showing a state before system error information corresponding to a characteristic of a standard vehicle used in a vehicle headlamp automatic optical axis direction adjusting apparatus according to a second embodiment of the present invention is taken into consideration; 5 is a table showing a prediction formula and a prediction formula in which system error information due to a mounting error of a vehicle height sensor to a vehicle is considered.

FIG. 11 is a view showing a state before system error information corresponding to a characteristic of a standard vehicle used in a vehicle headlamp automatic optical axis direction adjusting apparatus according to a second embodiment of the present invention is taken into consideration; 9 is a table showing a prediction formula and a prediction formula that takes into account system error information when the inclination of the prediction formula changes due to an error in the spring constant of the front and rear suspensions.

FIG. 12 is a diagram showing a vehicle height sensor used in a vehicle headlamp automatic optical axis direction adjusting apparatus according to a second embodiment of the present invention, which is based on a mounting error to a vehicle and other factors of the vehicle. 9 is a table showing five prediction formulas in which system error information including various errors is considered.

[Explanation of symbols]

 11 Vehicle Height Sensor 20 ECU (Electronic Control Unit) 30 Headlight (Headlight) 35 Actuator

Claims (3)

[Claims] A vehicle height sensor disposed at a front portion or a rear portion of a vehicle to detect a displacement amount of the vehicle height; and a plurality of vehicles having different inclinations corresponding to load conditions based on an output from the vehicle height sensor. A tilt angle calculating means for calculating a tilt angle of the headlight of the vehicle with respect to the horizontal plane in the optical axis direction using a prediction formula divided into vehicle postures, and the tilt angle calculated based on the tilt angle calculated by the tilt angle calculating means. An automatic optical axis direction adjusting device for a vehicle headlight, comprising: an optical axis direction adjusting means for adjusting an optical axis direction of a headlight. 2. The vehicle height sensor according to claim 2, wherein the inclination angle calculator has a plurality of prediction formulas divided into the plurality of vehicle attitudes corresponding to sensor outputs other than the vehicle height sensor disposed on the vehicle. 2. The automatic headlamp optical axis direction adjusting device according to claim 1, wherein the selection is made based on a sensor output other than the above. 3. A vehicle height sensor disposed at a front portion or a rear portion of the vehicle and detecting a displacement amount of the vehicle height, and various types based on an error caused by mounting the vehicle height sensor and other factors of the vehicle. And a plurality of vehicle postures having different inclinations corresponding to load conditions based on an output from the vehicle height sensor and the system error information stored in the storage unit. A tilt angle calculating unit that calculates a tilt angle of the headlight of the vehicle with respect to a horizontal plane in the optical axis direction using the divided prediction formula, and a head angle of the headlight based on the tilt angle calculated by the tilt angle calculating unit. An automatic optical axis direction adjusting device for a vehicle headlight, comprising: an optical axis direction adjusting means for adjusting an optical axis direction.