JP5260064B2 - Optical axis adjustment device for vehicle headlamp - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical axis adjusting device of a vehicle headlight configured to appropriately control an illumination direction with respect to a un-responding vehicle pitch and controlling the illumination direction with respect to a responding pitch even in traveling a rough road. <P>SOLUTION: This optical axis adjusting device 10 of the vehicle headlight includes a vehicle headlight 11 supported to a car body front part of the automobile swingably in the vertical direction, a drive means 12 swinging the vehicle headlight in the vertical direction, a car height sensor 13 detecting the height of the car body of the automobile, and a control part 14 computing the inclination of the car body of the automobile based on the detection signal from the car height sensor and controlling to actuate the drive means for offsetting the inclination. This optical axis adjusting device 10 of the vehicle headlight is so constituted that the control part computes the vehicle pitch based on the detection signal from the car height sensor, controls to correct the illumination angle with respect to the controllable and responding vehicle pitch for offsetting the vehicle pitch and restricts the illumination angle only for a predetermined time with respect to the non-controllable and un-responding vehicle pitch. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to an optical axis adjustment device for a vehicle headlamp that always keeps the light irradiation direction of the vehicle headlamp constant in accordance with the posture of a vehicle body.

In general, in vehicles, particularly automobiles, the angle in the front-rear direction of the vehicle body may be inclined with respect to the horizontal direction depending on the number of passengers and the load of the load, or the unevenness of the road surface or acceleration / deceleration. With the inclination, the light irradiation direction of the vehicle headlamp is also inclined.
For this reason, the so-called auto, in which the optical axis of the vehicle headlamp is adjusted in the vertical direction so as to always keep the light irradiation direction of the vehicle headlamp constant according to the inclination angle of the vehicle body of the automobile. Leveling devices are known.
Further, in such an automatic leveling device, it is also known that a good road / bad road determination is performed and a control method is switched on a good road / bad road in order to further enhance the control effect.

  For example, in Patent Document 1, in the irradiation direction control device that automatically corrects the irradiation direction of the lamp according to the vertical inclination in the traveling direction of the vehicle, the rough road determination means is the vehicle attitude detection means, the axle vibration detection means, Based on the information from the road surface state detection means, it is determined whether or not the road surface is a rough road state with many irregularities. When it is determined that the vehicle is traveling on a rough road, the rough road determination means sends a signal to the drive control means to fix the irradiation direction of the lamp in a predetermined direction or to limit the allowable range of the irradiation direction. Alternatively, an irradiation direction control device is disclosed in which the response speed of the driving means is decreased.

  According to the irradiation direction control device having such a configuration, forward visibility is improved by performing control so that excessive correction is not applied to the irradiation direction of the lamp during traveling on a rough road, and illusion light is emitted to an oncoming vehicle or the like. Can not be given.

Patent Document 2 discloses a rough road detection method.
According to this rough road detection method, the vertical acceleration of the vehicle body is detected, and the value of the rough road determination counter is incremented every time the vertical acceleration deviates from a predetermined region. Further, when the vertical acceleration is within a predetermined area, the count is counted down to the reference value as time elapses. Thus, it is determined that the vehicle is traveling on a rough road when the rough road determination counter is equal to or greater than the rough road determination threshold value, and is determined to be traveling on a good road when the rough road determination counter is smaller than the good road return threshold value.

According to the rough road detection method having such a configuration, for example, in an active suspension device, an undesired full bump in a vehicle can be obtained by changing the stiffness of the suspension in consideration of whether the road surface is a bad road or not. And full rebound can be effectively prevented.
Patent Registration No. 3128606 Patent Registration No. 2913802

By the way, in the irradiation direction control apparatus by patent document 1, bad road determination is performed based on many road surface unevenness | corrugations, and it will take time until it determines with a bad road. For this reason, during this time, irradiation direction control is performed even for vehicle pitches that cannot respond.
Also, time is similarly required for the good road determination. For this reason, during this time, accurate irradiation direction control is not performed with respect to the vehicle pitch which can respond.

  For this reason, if the control is performed as it is with respect to the vehicle pitch that cannot be responded to, the control will be shifted. For example, even though the vehicle body is facing upward (squat), the irradiation direction of the headlamp is further increased. In spite of such miscontrol, the illusion light on the oncoming vehicle increases, or the vehicle body is facing downward (dive), but the headlamp irradiation direction is further lowered. This may impair front visibility.

  On the other hand, in the rough road detection method according to Patent Document 2, accurate control is not performed with respect to the vehicle pitch that can be responded while a bad road is determined, and a response is made while a good road is determined. Control is performed even for vehicle pitches that cannot be performed. Therefore, there may occur a situation in which proper control is not performed during bad road determination and good road determination.

  In view of the above, the present invention performs an appropriate control of the irradiation direction with respect to a vehicle pitch that cannot respond, and controls the irradiation direction with respect to a vehicle pitch that can respond even when traveling on a rough road. It aims at providing the optical-axis adjustment apparatus of a lamp.

An optical axis adjustment device for a vehicle headlamp according to an aspect of the present invention includes a vehicle headlamp supported on a front part of a vehicle body so as to be swingable in a vertical direction, and swings the vehicle headlamp in a vertical direction. A driving means for moving the vehicle, a vehicle height sensor for detecting a vehicle height of the vehicle body of the vehicle, a tilt of the vehicle body of the vehicle based on a detection signal from the vehicle height sensor, and canceling the tilt. a control unit for driving and controlling the drive means includes, an optical axis adjusting apparatus for a vehicle headlamp, wherein the control unit, based on a detection signal of (a) the vehicle height sensor or al, It calculates a pitch rate from the vehicle pitch with calculating a vehicle pitch is the body of the slope of the motor vehicle, based on the pitch rate obtained by calculating (b), when the absolute value of the pitch rate is below the threshold, control response It determines that the vehicle pitch is detected as possible, the vehicle pitch And correction control the irradiation angle of the vehicle headlamp so as to cancel, (c) the calculated based on the pitch rate, when the absolute value of the pitch rate exceeds the threshold, the vehicle control response not determines the pitch is detected, which simply fixes the irradiation angle of the vehicle headlight to a predetermined angle predetermined time, furthermore, the control unit during the execution (d) is above (b), the control when it is determined that the response not possible to secure the irradiation angle θa and irradiation angle of only the headlamp the predetermined time when the correcting control the irradiation angle of the vehicle headlamp so as to cancel the vehicle pitch In the case where the absolute value | θa−θb | of the difference in the irradiation angle θb is smaller than a predetermined value, the process proceeds to the operation (c), and (e) after executing the (c) , The vehicle so that the vehicle pitch is canceled when it is determined that the control response is possible The absolute value | θa−θb | of the difference between the irradiation angle θa when the irradiation angle of the headlamp is corrected and controlled and the irradiation angle θb when the irradiation angle of the headlamp is fixed for the predetermined time is a predetermined value. An optical axis adjustment device for a vehicle headlamp that performs at least one of the operations of (b) only when smaller than that.

  According to the present invention, the object is to provide a vehicle headlamp that is supported at the front of the vehicle body so as to be swingable in the vertical direction, drive means for swinging the vehicle headlamp in the vertical direction, and the vehicle. A vehicle height sensor that detects the vehicle height of the vehicle body, a controller that calculates the inclination of the vehicle body based on the detection signal from the vehicle height sensor, and drives and controls the drive means so as to cancel the inclination; The vehicle headlamp optical axis adjustment device includes: a vehicle headlamp optical axis adjustment device, wherein the control unit calculates a vehicle body inclination (vehicle pitch) based on a detection signal from the vehicle height sensor or another sensor. When the vehicle pitch capable of control response is detected based on the calculated vehicle pitch, the control unit corrects and controls the irradiation angle of the vehicle headlamp so that the vehicle pitch is offset, and the control response When an impossible vehicle pitch is detected, And limits the irradiation angle of the vehicle headlamp only during the time the vehicle headlight optical axis adjustment device is achieved.

In the vehicle headlamp optical axis adjustment device according to the present invention, preferably, the control unit calculates a pitch speed from the calculated vehicle pitch, and determines that control response is impossible when the absolute value of the pitch speed exceeds a threshold value. To do. In the optical axis adjusting device for a vehicle headlamp according to the present invention, preferably, the control unit calculates a pitch acceleration from the calculated vehicle pitch, and determines that control response is impossible when the absolute value of the pitch acceleration exceeds a threshold value. To do.

  In the optical axis adjusting apparatus for a vehicle headlamp according to the present invention, preferably, the control unit fixes the irradiation angle of the vehicle headlamp at a predetermined angle when a vehicle pitch that cannot be controlled is detected.

  In the vehicle headlamp optical axis adjusting apparatus according to the present invention, preferably, the control unit limits the irradiation angle of the vehicle headlamp to a predetermined angle range when a vehicle pitch that cannot be controlled is detected.

  In the vehicle headlamp optical axis adjusting device according to the present invention, preferably, the control unit suppresses a response speed for driving and controlling the driving means to be low when a vehicle pitch incapable of control response is detected.

  According to the above configuration, when a vehicle pitch capable of control response is detected while the vehicle is running, the control unit drives and controls the drive means so as to cancel the vehicle pitch, and the vehicle headlamp The irradiation angle is corrected and controlled, and so-called auto-leveling dynamic control similar to the conventional one is performed.

On the other hand, when a vehicle pitch that cannot be controlled is detected while the vehicle is running, when the control unit controls the driving means, the irradiation angle of the vehicle headlamp is set for a predetermined time. Restrict.
Thus, for example, when the vehicle is traveling on a rough road and control cannot be performed in response to canceling the vehicle pitch, the irradiation angle of the vehicle headlamp is limited for a predetermined time, and the rough road Thus, the control in the direction opposite to the actual inclination of the vehicle body due to the control deviation of the optical axis adjustment corresponding to the vehicle pitch incapable of control due to the above is suppressed.

  In this way, the vehicle pitch that cannot be controlled is quickly detected, the irradiation angle of the vehicle headlamp is limited, and the light irradiation direction of the vehicle headlamp is out of control due to the uneven shape of the road surface. It can be suppressed that the light irradiation direction of the headlamp is temporarily upward or downward, and can be maintained within a predetermined angle range. Therefore, when the vehicle is traveling on a rough road, optical axis adjustment in the reverse direction with respect to the vehicle pitch that cannot be controlled does not give illusion light to oncoming vehicles and preceding vehicles, and forward visibility is impaired. There is no such thing as getting lost.

  In this case, the said control part restrict | limits the irradiation direction of a vehicle headlamp only during the predetermined time when the control shift by a vehicle pitch arises. Therefore, it is not necessary to perform control processing for adjusting the optical axis for a vehicle pitch that cannot be controlled, so that the control processing can be performed at a higher speed and control delay is reduced. Further, after the predetermined time has elapsed, the control returns to the normal control, and the control corresponding to the vehicle pitch that can be responded thereafter can be performed.

  When the control unit calculates the pitch speed or the pitch acceleration from the calculated vehicle pitch and determines that the control response is impossible when the absolute value of the pitch speed or the pitch acceleration exceeds the threshold, the shorter the vibration cycle, Also, the greater the amplitude, the greater the pitch speed or pitch acceleration. Therefore, when the absolute value of these pitch velocities or pitch accelerations exceeds the threshold value, it can be quickly determined that the control cannot be handled.

When the control unit detects a vehicle pitch that cannot respond to control, when the irradiation angle of the vehicle headlamp is fixed to a predetermined angle, an actual control error caused by the optical axis adjustment with respect to the vehicle pitch that cannot be controlled. Control in the direction opposite to the inclination of the vehicle body is suppressed.
Furthermore, it is not necessary to perform control processing for optical axis adjustment for a predetermined time, so that control processing can be performed at a higher speed, and control delay is reduced.

  When the control unit detects a vehicle pitch incapable of control response, and limits the irradiation angle of the vehicle headlamp to a predetermined angle range, the control unit actually performs an optical axis adjustment control deviation with respect to the vehicle pitch that cannot be controlled. Control in the direction opposite to the inclination of the vehicle body is suppressed.

  When the control unit detects a vehicle pitch incapable of control response and suppresses the response speed for driving and controlling the driving means to be low, the control deviation of the optical axis adjustment with respect to the vehicle pitch incapable of control does not increase. For this reason, control in the direction opposite to the actual inclination of the vehicle body due to the control deviation is suppressed. .

Thus, according to the present invention, when a vehicle pitch that cannot be controlled is detected during driving of the automobile, the control unit drives and controls the driving means to limit the irradiation angle of the vehicle headlamp to a predetermined angle. To do. As a result, when the vehicle body is greatly inclined and the vehicle pitch suddenly increases or decreases sharply when traveling on a rough road, the control unit quickly detects a vehicle pitch that cannot be controlled.
Therefore, even if a vehicle pitch that cannot be controlled occurs due to the unevenness of the road surface, correction control that cancels such a vehicle pitch is not performed, and the irradiation angle of the vehicle headlamp is limited. Thereby, the illumination angle of the vehicle headlamp is adjusted in the direction opposite to the vehicle pitch due to the control deviation, the optical axis of the vehicle headlamp is directed upward, and the oncoming vehicle and the preceding vehicle are given illusion light. In addition, the optical axis of the vehicle headlamp is directed downward, and the forward visibility is not impaired.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to FIGS.
The embodiments described below are preferable specific examples of the present invention, and thus various technically preferable limitations are given. However, the scope of the present invention particularly limits the present invention in the following description. As long as there is no description of the effect, it is not restricted to these aspects.

FIG. 1 shows the configuration of an embodiment of an optical axis adjusting device for a vehicle headlamp according to the present invention.
1 and 2, an optical axis adjustment device 10 for a vehicle headlamp includes a pair of left and right vehicle headlamps 11 attached to a front portion of a vehicle body B of an automobile so as to be swingable in the vertical direction, and the front of each vehicle. A pair of actuators 12 for swinging the lighting 11 in the vertical direction, a pair of vehicle height sensors 13 provided near the suspension of the front and rear wheels of the vehicle body B, and detection signals from these vehicle height sensors 13 And a control unit 14 that drives and controls the actuator 12 based on vehicle information of the automobile.

The vehicle headlamp 11 has a known configuration, for example, a configuration in which light from a light source is reflected by a reflector and irradiated with light in a predetermined light distribution pattern along the optical axis direction.
The vehicle headlamp 11 is configured such that the light distribution pattern is adjusted in the vertical direction by swinging the whole or at least a part of the vehicle headlamp 11 in the vertical direction.

  The actuator 12 has a known configuration, and is configured to move the lower side of the vehicle headlamp 11 in the vehicle front-rear direction, for example.

The vehicle height sensor 13 is a stroke sensor, for example, and is disposed near the suspension of the front wheels and / or the rear wheels.
The vehicle height sensor 13 detects the height of the vehicle body B of the automobile based on the suspension stroke.

The control unit 14 includes a calculation unit 14a, a travel detection unit 14b, and a memory 14c.
Thus, the calculation unit 14a of the control unit 14 performs calculation processing on the detection signal input from the vehicle height sensor 13 and the ignition signal, headlamp signal, and vehicle information of the vehicle by the vehicle pitch detection unit 14d. The inclination of the vehicle body B (vehicle pitch) is calculated, and it is determined by the determination unit 14e whether or not the calculated change in the vehicle body pitch can be controlled. Based on the determination result, the control angle calculation unit 14f performs vehicle heading. A control signal (control angle) for swinging the lamp 11 is generated and sent to the actuator 12.
The vehicle signal of the automobile is, for example, a vehicle speed signal, a travel acceleration, a throttle signal, a brake signal, and the like, and is input to the calculation unit 14a via the travel detection unit 14b.

The determination unit 14e determines whether or not the control can be handled as follows. That is, the determination unit 14e calculates a pitch speed (absolute value) Vabs as a value indicating a change in the vehicle pitch in the vehicle pitch detection unit 14d, and when the pitch speed Vabs exceeds the threshold value Vng, The response impossible flag Fng is set to 1 (Fng = 1), and when the pitch speed Vabs is equal to or less than the threshold value Vng, the response impossible flag Fng is set to 0 (Fng = 0). Here, the threshold value Vng is the maximum pitch speed that can be responded to .
When the maximum driving angular velocity in the irradiation direction of the system is Vsys, Vng <Vsys is set in consideration of the time required for actuator output from the detection of the stroke change, that is, the control delay ΔT.

Here, regarding the vehicle pitch, when the cycle is changed with the same amplitude, the vehicle pitch, the control position, the control deviation ΔT (= vehicle pitch-control position), and the pitch speed (absolute value) are shown in FIG. As shown in FIG. 3B, the medium cycle is represented as shown in FIG. 3B, and the short cycle is represented as shown in FIG. 3C.
Therefore, it can be seen that the control response becomes worse as the control deviation ΔT becomes larger and the Vsys becomes smaller.

Further, for the same ΔT, as the cycle becomes shorter, ΔT becomes relatively larger and the pitch speed (absolute value) becomes larger. As a result, it can be seen that the greater the pitch speed (absolute value), the more the control cannot follow the change in the vehicle pitch.
Similarly, even if the period is the same, as the amplitude increases, the pitch speed (absolute value) increases, and it can be seen that the control cannot follow the change in the vehicle pitch.
Therefore, it can be seen that when the pitch speed (absolute value) exceeds a certain threshold value, it is determined that the control response is impossible.

When the response impossible flag Fng shifts from 0 to 1 (Fng: 0 → 1), the determination unit 14e sets the control B maintaining time Tc in the counter C (C = Tc).
As long as Fng: 0 → 1 does not newly occur, the counter C is subtracted by the countdown amount S for each routine processing shown in FIG. 4 (C = C−S). When the subtraction result C = C−S becomes C <0, C = 0.
The countdown amount S is given by S = Tc / Ts. Here, Ts is a routine cycle.

The determination unit 14e sets the control A flag Fctr to 1 when C = 0, and sets the control A flag Fctr to 1, and sets the control A flag Fctr to 0 when C ≠ 0.
Accordingly, the determination unit 14e sends a control A flag to the control angle calculation unit 14f. When the control A flag is 1, the control angle calculation unit 14f selects the control A and the control A flag is 0. Control B is selected.

Here, based on the determination result of the determination unit 14e, the control unit 14 performs normal control (control A) similar to conventional auto leveling control (dynamic control) and special control (control B) described below. Are selectively switched.
In the control A, the control unit 14 calculates the vehicle body inclination by processing the detection signal input from the vehicle height sensor 13 by the vehicle pitch detection unit 14d, and calculates each control corresponding to this inclination. A control signal for swinging the vehicle headlamp 11 in a direction that cancels out the inclination is generated by the portion 14 f, and this control signal is sent to the actuator 13.

  Further, in the control B, the control unit 14 generates a control signal for fixing the irradiation direction of the vehicle headlamp 11 at the predetermined angle θ for the predetermined time Tc by the control angle calculation unit 14e. This control signal is sent to the actuator 13.

The predetermined time Tc described above is set as follows.
That is, it is considered that the response impossible time becomes longer as the pitch speed increases. Accordingly, the predetermined time Tc is set by Tc = a × Vabs (a: correlation coefficient) in correlation with the pitch velocity (absolute value) Vabs.

On the other hand, the predetermined time Tc may be a fixed value.
In this case, the predetermined time Tc may be set to Tc = b by measuring the maximum period b in which it is not possible to respond to one vehicle pitch by experiment, for example.
Further, the maximum cycle c of the vehicle pitch may be measured from the experiment, and Tc = c may be set. For reference, in the experiment, the maximum period exceeding ± 0.2 degrees was 1.48 seconds.
That is, the predetermined time Tc can be arbitrarily set as long as it can correspond to the response impossible time.

The vehicle headlamp optical axis adjusting apparatus 10 according to the embodiment of the present invention is configured as described above, and operates as follows.
As shown in the flowchart of FIG. 4, the control unit 14 first determines in step ST1 whether or not the pitch speed (absolute value) Vabs exceeds a threshold value Vng based on the vehicle pitch.
In the case of Y (yes) in step ST1, it is determined that the control response is impossible, and in step ST2, Fng = 1 is set, and the process proceeds to step ST4.
If N (no) in step ST1, it is determined that a control response is possible, and in step ST3, Fng = 0 is set, and the process proceeds to step ST4.

In step ST4, the control unit 14 determines whether or not Fng is 0 → 1, and if Fng is 0 → 1, the process proceeds to step ST9 with C = Tc in step ST5.
If Fng is not 0 → 1 in step ST4, the control unit 14 determines C = C−S in step ST6, and then determines whether C <0 in step ST7. To do.

If C <0 in step ST7, the control unit 14 sets C = 0 in step ST8, and proceeds to step ST9.
If C <0 is not satisfied in step ST7, the control unit 14 determines whether C = 0 in step ST9.

If C = 0 in step ST9, the control unit 14 selects control A with Fctr = 1 in step ST10.
If it is determined in step ST9 that C is not 0, the control unit 14 sets Fctr = 0 in step ST11 and selects control B.

In this way, the control unit 14 generates a control signal for adjusting the irradiation angle of the vehicle headlamp 11 according to the control A or the control B by the control angle calculation unit 14 f and outputs the control signal to the actuator 13. .
Thereby, in the control A, the actuator 13 adjusts the irradiation angle of the vehicle headlamp 11 in accordance with the vehicle pitch by the conventional so-called dynamic control, and in the control B, the irradiation angle of the vehicle headlamp 11 is set to a predetermined value. The angle is fixed to θ.
Therefore, the control unit 14 repeats the above-described steps ST1 to ST10, and the irradiation angle of the vehicle headlamp 11 is adjusted by the control A or the control B.

FIG. 5 shows a specific control example by the optical axis adjusting apparatus 10 for the vehicle headlamp described above.
In FIG. 5, only when the pitch speed (absolute value) Vabs of the vehicle pitch exceeds the threshold value Vng, the response impossible flag Fng is set to 1, and the counter C is subtracted according to the control B only for a predetermined time Tc. The irradiation angle of the vehicle headlamp 11 is fixed.

Thereby, the optical axis adjustment in the direction opposite to the direction in which the vehicle pitch is canceled is not performed by the conventional control deviation with respect to the vehicle pitch, and the actual control deviation is greatly reduced.
This eliminates the upward state of the optical axis due to the change in the vehicle pitch due to the road surface unevenness of the vehicle headlamp 11 that cannot be corrected in time by the control A, so that the vehicle headlamp 11 has a substantially predetermined angle θ. Light is emitted at an irradiation angle, and it is possible to prevent the oncoming vehicle and the preceding vehicle from giving illusion light, or to eliminate the downward state of the optical axis. Light is irradiated at an angle, and forward visibility can be ensured.

FIG. 6 shows the relationship between the vehicle headlamp irradiation direction (control position) and the vehicle pitch under control B.
In this case, the control position is constant regardless of the fluctuation of the vehicle pitch.
On the other hand, FIG. 7 shows the relationship between the irradiation direction (control position) of the vehicle headlamp by the control A and the vehicle pitch.
In this case, the control position varies depending on the constant control delay ΔT and the response performance of the actuator in accordance with the variation of the same vehicle pitch as that of FIG.

FIG. 8 shows the control deviation in the region X of FIGS. 6 and 7 described above.
Regarding the control A, in the region Y where the vehicle pitch fluctuates rapidly, the control effect is not effective, the control deviation becomes large, and the control in the reverse direction is conspicuous, but in the region Z where the vehicle pitch fluctuates gently. It can be seen that the control effect is effective and the control deviation is kept low.
On the other hand, with respect to the control B, in the region Y where the vehicle pitch fluctuates rapidly, the control effect is effective, and the control deviation is reduced as compared with the control A, but the region where the vehicle pitch fluctuates gently. In Z, the control deviation is larger than that in the control A.

FIG. 9 shows the relationship between the pitch speed (absolute value) Vabs and the threshold value Vng with respect to the same vehicle pitch variation as in FIGS.
In this case, in the region Y where the control effect of the control A is not effective, the pitch velocity (absolute value) Vabs is large and exceeds the threshold value Vng, but in the region Z where the control effect of the control A is effective, the pitch velocity (absolute Value) Vabs is small and is found to be below the threshold value Vng.

Therefore, it can be seen that the control by the control A is performed in the region Y, and the control by the control A is not performed in the region Z, and the irradiation angle of the vehicle headlamp is fixed and the optimal control can be performed.
As a result, as shown in FIG. 10, the portion where the pitch velocity (absolute value) Vabs exceeds the threshold value Vng is regarded as being uncontrollable. The control in the reverse direction is suppressed without adjusting the irradiation angle of the lamp 11.

Here, for example, a sudden change in the vehicle pitch is often absorbed by the suspension of the automobile, and it is considered that the body posture of the automobile does not change corresponding to the detected vehicle pitch.
In such a case, if the irradiation angle of the vehicle headlamp 11 is adjusted by the control A described above, excessive control will result.
Even in such a case, when the fluctuation of the vehicle pitch is large and the pitch speed (absolute value) exceeds the threshold value, the irradiation angle of the vehicle headlamp 11 is fixed according to the control B, and over-control can be effectively prevented. become.

The switched when the control A⇔ control B, the difference between the irradiation angle θb of the irradiation angle θa and the control B the control A is large, it becomes the irradiation light varies suddenly increases, considered that would give a visual sense of discomfort to the driver It is done.
The following two methods can be considered as countermeasures for this event. If necessary, countermeasures may be taken by either or both methods.
Regarding the transition from Control A to Control B,
| Θa−θb | <ε (ε: threshold of irradiation angle difference, for example, ε = 0.1 deg)
The condition of is added.
For the transition from control B to control A, after the transition condition is satisfied,
| Θa−θb | <ε (ε: threshold of irradiation angle difference, for example, ε = 0.1 deg)
Transition when the condition is satisfied.

In the embodiment described above, the pitch speed indicating the change in the vehicle pitch is used as the vehicle information to detect the control response failure. However, the present invention is not limited to this, and any control response failure can be detected. It is also possible to use other arbitrary vehicle information such as pitch acceleration.
In the above-described embodiment, the stroke sensor is used as the vehicle height sensor to detect the vehicle pitch. However, the present invention is not limited to this, and any sensor that can detect the vehicle pitch, for example, an angular velocity sensor or an acceleration sensor. It is also possible to use an ultrasonic sensor or the like.

  Further, in the above-described embodiment, in the control B, the irradiation angle of the vehicle headlamp 11 is fixed to the predetermined angle θ. However, the present invention is not limited to this, and the optical axis adjustment in the reverse direction due to the control deviation is opposite. As long as the vehicle or the like is given dazzling light or the forward visibility is not impaired, for example, the irradiation range, that is, the adjustment range of the optical axis may be limited, or the response time may be delayed.

The vehicle headlamp optical axis adjusting device 10 according to the present invention is configured to adjust the optical axis of a vehicle headlamp such as a headlamp. However, the present invention is not limited thereto, and an auxiliary headlamp such as a foglanf is used. It is possible to apply the present invention to a vehicle headlamp including
Further, the optical axis adjusting device 10 for a vehicle headlamp according to the present invention can be incorporated into a suspension control system.

  Thus, according to the present invention, appropriate control of the irradiation direction is performed for a vehicle pitch that cannot be responded, and control of the irradiation direction is performed for a vehicle pitch that can be responded even when traveling on a rough road. An extremely excellent vehicle headlamp optical axis adjusting device can be provided.

It is a block diagram which shows the structure of one Embodiment of the optical-axis adjustment apparatus of the vehicle headlamp by this invention. It is the schematic which shows the mounting state to the motor vehicle of each element in the optical axis adjustment apparatus of the vehicle headlamp of FIG. It is a graph which shows the vehicle pitch, control position, control deviation, and pitch speed (absolute value) in (A) long period, (B) middle period, and (C) short period. It is a flowchart which shows the control in the optical axis adjustment apparatus of the vehicle headlamp of FIG. It is a time chart which shows the relationship between the pitch speed (absolute value), the response impossible flag, a counter, and the control A flag in the optical axis adjusting device of the vehicle headlamp of FIG. It is a graph which shows the relationship between the vehicle pitch by control B with respect to the fluctuation | variation of a certain vehicle pitch, and a control position. It is a graph which shows the relationship between the vehicle pitch by control A with respect to the fluctuation | variation of the vehicle pitch of FIG. 6, and a control position. It is a graph which shows the control deviation in the area | region X of FIG.6 and FIG.7. It is a graph which shows the relationship between the pitch speed (absolute value) with respect to the fluctuation | variation of the vehicle pitch of FIG.6 and FIG.7, and a threshold value. It is a graph which shows the relationship between the control position by control A and control B with respect to the fluctuation | variation of the vehicle pitch of FIG.6 and FIG.7, and the state of a response impossible flag.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Optical axis adjustment apparatus of vehicle headlamp 11 Vehicle headlamp 12 Actuator (drive means)
13 Vehicle height sensor 14 Control unit

Claims (1)

A vehicle headlamp supported at the front of the vehicle body so as to be swingable in the vertical direction;
Drive means for swinging the vehicle headlamp in the vertical direction;
A vehicle height sensor for detecting the vehicle height of the vehicle body;
A control unit that calculates the inclination of the vehicle body of the automobile based on the detection signal from the vehicle height sensor and drives and controls the driving means so as to cancel the inclination;
An optical axis adjustment device for a vehicle headlamp, comprising:
The control unit
(a) the vehicle based on the height sensor or these detection signals, calculates the pitch speed from the vehicle pitch with calculating a vehicle pitch is the body of the inclination of the motor vehicle,
(b) the calculated based on the pitch rate, when the absolute value of the pitch rate is equal to or smaller than a threshold, it determines that the control response can be the vehicle pitch is detected, the vehicle so as to cancel out the vehicle pitch Correct and control the irradiation angle of the headlamp,
(c) Based on the calculation above pitch speed, when the absolute value of the pitch rate exceeds the threshold, it is determined that the vehicle pitch control response not is detected, a predetermined time only the irradiation of the vehicle headlamp The angle is fixed to a predetermined angle,
Furthermore, the control unit
(d) during the (b), when it is determined that the control response Not possible, and the irradiation angle θa of the case of correction control the irradiation angle of the vehicle headlamp so as to cancel the vehicle pitch Shifting to the operation of (c) only when the absolute value | θa−θb | of the difference in the irradiation angle θb when the irradiation angle of the headlamp is fixed for the predetermined time is smaller than the predetermined value;
as well as,
(e) after performing the above (c), when it is determined that the control can respond, the irradiation angle θa to the above case of correcting control the irradiation angle of the vehicle headlamp so as to cancel the vehicle pitch Shifting to the operation of (b) only when the absolute value | θa−θb | of the difference in the irradiation angle θb when the irradiation angle of the headlamp is fixed for a predetermined time is smaller than the predetermined value;
Perform at least one of the
Optical axis adjustment device for vehicle headlamps.

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