JP2013014229A - Optical axis control device of on-vehicle head lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical axis control device of an on-vehicle head lamp configured to determine a traveling state suitable for optical axis correction with high accuracy.SOLUTION: The optical axis control device of an on-vehicle head lamp includes: an adjuster 6 for adjusting an optical axial angle of the on-vehicle head lamp 5 in vertical direction; a drive torque calculator 2a for calculating drive torque Td that acts on a drive wheel of a vehicle 10; a determiner 3 for determining whether the vehicle 10 is in static state or moving state; and a controller 4 for allowing the adjuster 6 to adjust the optical axial angle when the determiner 3 determines that the vehicle 10 is in the static state, and prohibits the adjustment when determining that the vehicle is in the moving state.

Description

  The present invention relates to an optical axis control device that automatically controls the optical axis angle of an in-vehicle headlamp.

  2. Description of the Related Art Conventionally, an optical axis control device that automatically tilts and adjusts the optical axis angle of an in-vehicle headlamp according to the attitude of a vehicle is known. The headlamp controlled by the optical axis control device incorporates an actuator, and the optical axis angle is adjusted by changing the direction of the light source or reflector in the vertical direction by the actuator. For example, when the number of vehicle occupants increases and the vehicle height decreases and the headlamp irradiation position approaches the road surface, the light beam can reach far by reducing the optical axis angle (Depression angle). Control to ensure the distance is performed. Such an optical axis control device is also called an auto leveling device.

  By the way, this type of optical axis control device includes a dynamic type and a static type. The former controls the optical axis angle in real time in all states including when the vehicle is running. For example, the light irradiation distance is adjusted so as to correspond to a change in posture caused by acceleration / deceleration of the vehicle. However, the dynamic optical axis control apparatus requires a high degree of durability for the components for driving the light source and the reflector in addition to the high frequency of operation of the actuator and high power consumption. Therefore, there is a demerit that costs for manufacturing and maintenance tend to be high, and cost effectiveness is low.

  On the other hand, the latter mainly controls the angle of the optical axis when the vehicle is stopped. For example, the light irradiation distance is adjusted according to the number of passengers and the load when the vehicle is stopped. This static type optical axis control device is less power intensive than the dynamic type because the actuator is operated less frequently, and it is possible to ensure sufficient quality with general-purpose parts for durability. On the other hand, the light irradiation distance is not adjusted when the posture of the vehicle body changes during the traveling of the vehicle, so that it does not reach the dynamic type in terms of convenience.

  In recent years, with the aim of improving the convenience, there has been proposed a static optical axis control device that can adjust the optical axis angle even when the vehicle is not in a stopped state. For example, Patent Document 1 describes that the vibration width of the vehicle body and the engine speed are referred to as conditions for starting the optical axis correction of the headlamp. In this technique, even when the vehicle is traveling, the optical axis correction of the headlamp is started when traveling at a constant speed at a low speed where the vehicle body is not vibrating. As described above, it is possible to improve the convenience while suppressing the cost by determining the traveling state suitable for the optical axis correction of the static headlamp.

JP 2009-248627 A

However, with the conventional technology as described above, there are cases where it is not possible to correctly grasp the running state suitable for performing optical axis correction of a static headlamp. For example, as described in Japanese Patent Application Laid-Open No. H10-228707, when the traveling state is determined based on the engine speed, the vehicle posture is stable even when the engine rotational speed is high to some extent during constant speed traveling on an expressway. On the other hand, even when the engine speed is low, the vehicle body may be in an unstable posture inclined in the front-rear direction, such as when the vehicle starts or just before it stops. Therefore, it is difficult to correctly determine a state that does not hinder the optical axis correction based on the engine speed.
Thus, the conventional headlamp optical axis control device has a problem that it may be difficult to further improve the accuracy of determination of the running state of the vehicle.

One of the purposes of the present case is to determine a traveling state suitable for performing optical axis correction with high accuracy in an optical axis control device for an in-vehicle headlamp.
The present invention is not limited to this purpose, and is a function and effect derived from each configuration shown in the embodiments for carrying out the invention described later, and other effects of the present invention are to obtain a function and effect that cannot be obtained by conventional techniques. Can be positioned.

  (1) An on-vehicle headlamp optical axis control device disclosed herein includes an adjusting unit that adjusts an optical axis angle of an on-vehicle headlamp in a vertical direction, and a driving torque calculating unit that calculates a driving torque acting on driving wheels of a vehicle. With. In addition, based on the driving torque, there is provided discrimination means for discriminating whether the vehicle is in a static running state or a dynamic running state. Further, the adjustment means permits the adjustment of the optical axis angle when the vehicle is determined to be in the static running state, and the adjustment is performed when it is determined that the vehicle is in the dynamic running state. The control means to prohibit is provided.

  Here, the “static running state” means a state where the running is continued while the posture of the vehicle in the pitch direction is substantially maintained at the posture at the time of stopping. The “dynamic running state” means a running state other than the “static running state”, and means a running state in which the posture of the vehicle in the pitch direction is not necessarily maintained at the posture when the vehicle is stopped. Both of these are one of the traveling states of the vehicle, and the stopped state of the vehicle is not included in these states.

(2) Further, the determination means determines that the static running state is present when the value of the drive torque is within a predetermined range set in advance, and otherwise indicates the dynamic running state. It is preferable to determine.
(3) Moreover, it is preferable that the said drive torque calculating means calculates the said drive torque based on the gear ratio between an engine and the said driving wheel, and the engine torque output from the said engine. For example, in an automobile or a hybrid vehicle in which a transmission is interposed between the engine and the driving wheel, the transmission ratio is grasped based on the operating state of the transmission.

(4) Moreover, it is preferable that the said drive torque calculating means calculates the said drive torque based on the motor torque output from the motor for driving | running | working. For example, in an electric vehicle having no transmission, the driving torque is grasped based on the motor torque.
(5) Alternatively, it is preferable that the driving torque calculating means calculates the driving torque based on a speed ratio between the traveling motor and the driving wheels and the motor torque. For example, in an electric vehicle in which a transmission is interposed between the traveling motor and the driving wheel, the driving torque is grasped based on the transmission ratio and the motor torque.

  According to the disclosed in-vehicle headlamp optical axis control device, a driving state suitable for performing optical axis correction by using the driving torque of the driving wheel as a determination condition for permitting or prohibiting the adjustment of the optical axis angle. Can be discriminated with high accuracy. For example, the determination accuracy of the traveling state can be improved as compared with the method of determining the traveling state using the engine speed. As a result, it is possible to extend the life of the parts related to the adjustment of the optical axis angle, and to improve the balance between cost and convenience.

1 is a side view schematically showing a vehicle to which an optical axis control device according to an embodiment is applied. FIG. 2 is a block diagram illustrating a configuration of an optical axis control device in FIG. 1. It is a graph for demonstrating the control content in the optical axis control apparatus of FIG. 3 is a flowchart illustrating a control procedure in the optical axis control device of FIG. 1.

  The control device will be described with reference to the drawings. Note that the embodiment described below is merely an example, and there is no intention to exclude various modifications and technical applications that are not explicitly described in the following embodiment. In addition, each configuration of the following embodiment can be selected as necessary, or may be appropriately combined, and various modifications can be made without departing from the spirit of the embodiment.

[1. Device configuration]
The on-vehicle headlamp optical axis control device of this embodiment is mounted on a vehicle 10 shown in FIG. The vehicle 10 is a gasoline vehicle that travels using the engine 7 as a drive source. The driving force generated by the engine 7 is transmitted to the driving wheels among the wheels 11 via the transmission 9 and a power transmission path (not shown).
A pair of left and right headlamps 5 is provided at the front portion of the vehicle 10. Each headlamp 5 incorporates an actuator 6 (adjustment means) for adjusting the light irradiation direction up and down, and tilts and adjusts the optical axis angle according to the attitude of the vehicle 10.

  For example, as schematically shown in FIG. 2, a reflector 5b arranged around the light source 5a of the headlamp 5 is provided so as to be swingable in the vertical direction. The direction of the swing central shaft 5c of the reflector 5b is the vehicle width direction of the vehicle 10. The tip of the rod 6a of the actuator 6 that expands and contracts in the horizontal direction (vehicle longitudinal direction) is pin-bonded to the reflector 5b. With such a structure, the reflector 5b swings according to the amount of expansion and contraction of the rod 6a in the horizontal direction, and the optical axis angle is adjusted in the vertical direction. The actuator 6 that drives the rod 6a is controlled by the optical axis controller 1 described later.

  The actuator 6 according to the present embodiment is an adjusting unit that adjusts the optical axis angle not only when the vehicle 10 is stopped but also during traveling. However, the optical axis angle is not adjusted in an unlimited manner while the vehicle 10 is traveling, but is controlled so as to adjust the optical axis angle only in a traveling state suitable for performing optical axis correction.

  The vehicle 10 is provided with an optical axis control device 1 and an engine control device 8 as electronic control devices for controlling the engine 7 and the headlamp 5 described above. These control devices are configured as LSI devices or embedded electronic devices in which a microprocessor, ROM, RAM, and the like are integrated, for example, and are connected to each other via communication lines such as CAN and FlexRay provided in the vehicle 10. These control devices are energized when an operation position of an ignition switch (not shown) is an accessory position or an ON position (a position corresponding to a state where the engine 7 is started), and start various controls.

  The engine control device 8 is an electronic control device that controls a wide range of systems such as an ignition system, a fuel system, an intake / exhaust system, and a valve system related to the engine 7. It controls the amount of air to be introduced, the amount of fuel injection, and the ignition timing. Further, the engine 7 is provided with an engine speed sensor 16 for detecting the engine speed Ne, and information on the engine speed Ne detected here is transmitted to the optical axis control device 1 and the engine control device 8. ing.

Inside the engine control device 8, a predetermined calculation method based on an accelerator operation amount θ _AC detected by an accelerator sensor 15 described later, a wheel speed Vt detected by a wheel speed sensor 14, a fuel injection amount, an engine speed Ne, and the like. Thus, the value of the engine torque Te output from the engine 7 is calculated at any time. The engine torque Te is, for example, a torque value output from the output shaft of the engine 7 and is a torque input from the engine 7 to the transmission 9. The value of the engine torque Te calculated here is transmitted to the optical axis control device 1. Note that the value of the engine torque Te is also used for actual control of the engine 7.

  The optical axis control device 1 is an electronic control device that controls the light amount, light distribution state, optical axis angle, and the like of the headlamp 5. As shown in FIG. 2, the engine control device 8, the door sensor 12, the height sensor 13, the wheel speed sensor 14, and the accelerator sensor 15 are connected to the input side of the optical axis control device 1.

  The door sensor 12 is an open / close sensor provided in each door 17 on both side surfaces of the vehicle 10, and detects the open / close state of each door 17 and outputs an open / close signal P corresponding thereto. . These opening / closing signals P are transmitted to the optical axis control device 1.

  The height sensor 13 is a sensor attached to the suspension device that suspends the wheel 11 from the vehicle body, and detects the vehicle height H corresponding to the amount of expansion and contraction of the suspension spring 18. Although FIG. 1 illustrates an example in which only one height sensor 13 is provided in the suspension device for the rear wheel of the vehicle 10, the height sensor 13 may be provided in each of the suspension devices for both the front wheel and the rear wheel.

  The vehicle height H detected by the height sensor 13 is a parameter corresponding to the height from the ground at the position where the height sensor 13 is provided, in other words, a parameter corresponding to the degree of inclination of the vehicle 10. The fluctuation of the vehicle height H corresponds to the vibration of the vehicle body, and the larger the vibration, the larger the amplitude of the vehicle height H and the fluctuation frequency (frequency). Information on the vehicle height H detected here is transmitted to the optical axis control device 1 as an index for grasping the posture and vibration state of the vehicle 10.

  The wheel speed sensor 14 detects (or calculates) the rotation angle of the axle supporting the wheel 11 and its angular speed. The amount of change in the rotation angle of the axle per unit time is proportional to the rotational speed of the wheel 11, and if no slip occurs, the rotational speed of the wheel 11 is proportional to the wheel speed Vt (vehicle speed). Information on the wheel speed Vt detected (or calculated) here is transmitted to the optical axis control device 1 and the engine control device 8. The wheel speed Vt may be calculated by the optical axis control device 1 based on the rotation angle of the axle detected by the wheel speed sensor 14.

The accelerator sensor 15 is a stroke sensor that detects an operation amount θ _AC (accelerator operation amount) corresponding to the depression amount of the accelerator pedal. The accelerator operation amount θ _AC is a parameter corresponding to the driver's acceleration request, that is, corresponds to an output request to the engine 7. Information on the accelerator operation amount θ _AC detected here is transmitted to the optical axis control device 1 and the engine control device 8.

[2. Control configuration]
[2-1. Overview of control]
The actuator 6 is connected to the output side of the optical axis control device 1. The optical axis control device 1 of the present embodiment performs optical axis control of the headlamp 5 based on the input information. The optical axis control here refers to automatically tilting the optical axis angle (the depression angle) of the headlamp 5 by controlling the operation amount of the actuator 6 (the expansion and contraction operation amount of the rod 6a) according to the attitude of the vehicle 10. It is control to adjust.

  Specifically, the actuator 6 estimates the pitch angle θ (tilt in the front-rear direction) of the vehicle 10 based on the vehicle height H detected by the height sensor 13 and secures the irradiation distance according to the pitch angle θ. This is the control for driving the rod 6a. For example, using the state where the vehicle 10 is stopped on a horizontal road surface as a reference state, the actuator is configured such that the optical axis angle decreases as the pitch angle θ increases and the optical axis angle increases as the pitch angle θ decreases. 6 is driven. In other words, the actuator 6 is driven so that the irradiation direction is upward as the tendency of the forward leaning posture is increased, and the irradiation direction is downward as the tendency of the backward leaning posture is increased.

In the present embodiment, the state of the vehicle 10 is classified into the following three types. The optical axis control device 1 performs optical axis control when it is in the following state (1) or (2).
(1) The vehicle 10 is in a stopped state (stopped) (2) The vehicle 10 is traveling and is in a static traveling state (3) The vehicle 10 is traveling and is in a dynamic traveling state

  The above (1) includes, for example, the idling stop time immediately after the engine 7 is started. In addition, when the vehicle 10 once stops running (for example, when a signal is temporarily stopped), it is considered that the posture of the vehicle 10 does not change because there is no change in the number of passengers or cargo. Therefore, it may be in a state not included in the above (1) (a state in which optical axis control is not performed).

The above (2) includes, for example, traveling at a constant vehicle speed (during constant speed traveling or autocruising). The static running state means a state where the running of the vehicle 10 is continued while the posture of the vehicle 10 in the pitch direction is substantially maintained at the posture at the time of stopping. In other words, compared to when the vehicle is stopped, the posture in the pitch direction with respect to the road surface is almost the same, the posture does not change dynamically, and it is relatively stable so that a certain amount of time is maintained. In the traveling state, the optical axis angle is adjusted.
On the other hand, said (3) respond | corresponds to driving states other than (2). That is, the optical axis angle is not adjusted when the vehicle 10 is in a relatively unstable running state in which the attitude of the vehicle 10 is dynamically changing.

[2-2. Control block configuration]
As shown in FIG. 2, the optical axis control device 1 includes a calculation unit 2, a determination unit 3, and a control unit 4. Each function of the calculation unit 2, the determination unit 3, and the control unit 4 may be realized by an electronic circuit (hardware), may be programmed as software, or one of these functions. The part may be provided as hardware and the other part may be software.
The computing unit 2 performs computations related to the optical axis control described above, and includes a drive torque computing unit 2a and a moving distance computing unit 2b.

  The drive torque calculator 2a (drive torque calculator) calculates the drive torque Td of the vehicle 10, that is, the drive torque Td acting on the drive wheels. Here, the drive torque Td of the vehicle 10 is calculated based on the engine torque Te, the engine speed Ne, and the wheel speed Vt transmitted from the engine control device 8. Further, the gear ratio R including the gear ratio of the transmission 9 is calculated from the engine speed Ne and the wheel speed Vt.

Further, for example, according to the following equation 1, the gear ratio R multiplied by the engine torque Te is obtained as the drive torque Td.
(Drive torque Td) = (Engine torque Te) × (Speed change ratio R) (Formula 1)
Note that when the engine control device 8 knows the operating state of the transmission 9, information on the gear ratio R may be received from the engine control device 8. Information on the drive torque Td calculated here is transmitted to the determination unit 3.

  The movement distance calculation unit 2b calculates the movement distance L of the vehicle 10 based on the wheel speed Vt. The moving distance L here is the distance that the vehicle 10 has moved from the position when the ignition switch of the vehicle 10 is turned on. However, when any door 17 of the vehicle 10 is opened, the moving distance L is reset. The travel distance L corresponds to the distance traveled in a state where the number of passengers and the load affecting the posture of the vehicle 10 do not change. Information on the movement distance L calculated here is transmitted to the control unit 4.

  The determination unit 3 (determination means) determines whether the vehicle 10 is in a static running state or a dynamic running state based on the driving torque Td calculated by the driving torque calculating unit 2a. That is, it is determined here whether the traveling state of the vehicle 10 is (2) or (3). The determination unit 3 stores in advance a map, an arithmetic expression, and the like that define a correspondence relationship between the value of the driving torque Td and the state of the vehicle 10, and determines the state of the vehicle 10 using these maps, the arithmetic expression, and the like. To do.

  For example, as shown in FIG. 3, when the driving torque Td exceeds a predetermined positive value Tmax or is less than a predetermined negative value Tmin, it is determined that the traveling state of the vehicle 10 is a dynamic traveling state. When the driving torque Td is in the range of Tmin or more and Tmax or less, it is determined that the vehicle is in a static running state. The positive torque corresponds to the force that drives the vehicle 10 in the forward direction, and the negative torque corresponds to the force that drives the vehicle 10 in the backward direction. The traveling state of the vehicle 10 determined here is transmitted to the control unit 4.

The control unit 4 (control unit) performs optical axis control based on the movement distance L calculated by the movement distance calculation unit 2b, the opening / closing signal P from the door sensor 12, the determination result by the determination unit 3, and the like. It is.
First, when the vehicle is stopped and the moving distance L is L = 0, the state of the vehicle 10 corresponds to the above (1), so the control unit 4 performs optical axis control. For example, when the ignition switch is operated to the accessory position or when idling stops immediately after the engine 7 is started, auto-leveling is performed according to the change in the posture of the vehicle 10.

  Further, even when the vehicle 10 is stopped, if the moving distance L is not L = 0, the optical axis control is not performed. For example, in a state where the vehicle 10 is temporarily stopped to wait for a signal at the intersection after starting, the posture of the vehicle 10 is considered not to have changed from the posture at the time of stopping before starting, so the optical axis control is prohibited. The actuator 6 is maintained in a stopped state.

On the other hand, when the vehicle is traveling, the optical axis control is performed when the traveling state of the vehicle 10 is the static traveling state, and the optical axis control is prohibited when the traveling state is the dynamic traveling state. That is, auto leveling is performed when the state of the vehicle 10 is (2), and auto leveling is not performed when the state is (3).
When the optical axis control starts, the pitch angle θ of the vehicle 10 is estimated and calculated based on the vehicle height H detected by the height sensor 13, and a drive signal is output from the control unit 4 to the actuator 6 according to the pitch angle θ. Is done. Thereby, the optical axis angle of the headlamp 5 is automatically tilted and the irradiation distance of light is ensured.

[3. flowchart]
[3-1. Calculation of moving distance]
FIG. 4 is a schematic flowchart for explaining a procedure of optical axis control executed by the optical axis control device 1. The control shown in this flowchart is started when the ignition switch of the vehicle is operated to the accessory position or the on position and the optical axis control device 1 is energized, and is set in a predetermined cycle (for example, several tens [ms]) Cycle). In this embodiment, the initial set value of the movement distance L integrated by the optical axis control device 1 is set to L = 0, and the value of the movement distance L of the movement distance calculation unit 2b is reset at the start of this flow. .

  In step S10, information from various sensors connected to the input side of the optical axis control device 1 is read. For example, the opening / closing signal P from the door sensor 12, information on the wheel speed Vt from the wheel speed sensor 14, information on the vehicle height H from the height sensor 13, engine torque Te from the engine control device 8, and engine speed sensor 16 Information on the engine rotational speed Ne is input to the optical axis control device 1. Note that the values of the engine torque Te and the engine speed Ne when the engine 7 is not started are both zero.

  In step S12, based on the opening / closing signal P from the door sensor 12, it is determined whether any door 17 of the vehicle 10 is open. If there is an open door 17, the process proceeds to step S <b> 14 and the movement distance L is reset to L = 0. If all the doors 17 are closed, the process proceeds to step S <b> 16 and the movement distance L is calculated.

This moving distance L is cumulatively calculated based on the previous value L ′ of the moving distance obtained in the previous calculation cycle, for example, according to the following Equation 2. In Equation 2, k is a predetermined coefficient, and k · Vt corresponds to the moving distance of the vehicle 10 from the previous calculation cycle. Therefore, when the vehicle 10 is stopped, the value of the movement distance L does not change.
(Travel distance L) = (previous value L ') + k · Vt (Formula 2)

[3-2. Control without driving torque]
In step S18, it is determined whether the drive torque Td is generated (Td ≠ 0) or not (Td = 0). Here, for example, it is determined whether or not the engine torque Te is zero. When the engine torque Te of the engine 7 is Te = 0, the drive torque Td is not generated, so the process proceeds to step S20. On the other hand, when the engine 7 is started (during idling, normal running, etc.), Te ≠ 0, that is, the drive torque Td is generated, so the process proceeds to step S28. The presence or absence of the drive torque may be determined using the engine speed Ne instead of the engine torque Te. Further, in consideration of calculation error and control error, the determination threshold value of the engine torque Te may be an arbitrary constant instead of 0.

  In step S20, it is determined whether or not the vehicle body is oscillating based on the variation in the vehicle height H. For example, it is determined that the vehicle body is vibrating when the amplitude (or vibration frequency) of the temporal fluctuation of the vehicle height H is greater than or equal to a predetermined value, and the process proceeds to step S34. On the other hand, when it is determined that the vehicle body is not oscillating, it is considered that the vehicle posture is stable and the process proceeds to step S22.

  In step S22, the pitch angle θ of the vehicle 10 is estimated based on the vehicle height H, and the drive target value of the actuator 6 is calculated according to the pitch angle θ. In the subsequent step S24, a drive signal corresponding to the drive target value is output to the actuator 6, and the optical axis angle of the headlamp 5 is automatically tilt-adjusted.

[3-3. Control with drive torque (when the vehicle is stopped)]
When it is determined in step S18 that the drive torque Td is generated, the process proceeds to step S28, and it is determined whether or not the moving distance L of the vehicle 10 is L = 0. Here, L = 0 is, for example, immediately after the engine 7 is started or when any one of the doors 17 is opened, and is limited to a state where the vehicle 10 has not started yet. Therefore, if the movement distance L is L = 0, it is determined that the vehicle 10 is stopped, and the process proceeds to step S30. On the other hand, when L ≠ 0, it is determined that the vehicle 10 is traveling, and the process proceeds to step S32. In the determination in step S28, an arbitrary constant may be used as the determination threshold value for the movement distance L instead of 0.

In step S30, it is determined whether or not the accelerator is in an open state based on the information on the accelerator operation amount θ _AC detected by the accelerator sensor 15. For example, when θ _AC = 0, the process proceeds to step S20, and when θ _AC ≠ 0, the process proceeds to step S34. As with the movement distance L, an arbitrary constant may be used as the determination threshold value for the accelerator operation amount θ _AC instead of 0.

  If it is determined in steps S28 to S30 that the accelerator pedal is depressed even when the vehicle 10 is stopped, the process proceeds to step S34. In step S34, the optical axis control is not performed, that is, the actuator 6 is not driven and adjustment of the optical axis angle is prohibited. Therefore, the optical axis control is performed when the vehicle 10 is stopped only when the vehicle 10 is stopped in a stable vehicle posture.

[3-4. Control with drive torque (when driving)]
If it is determined in step S28 that the vehicle 10 is traveling, the process proceeds to step S32, and the value of the drive torque Td is determined. At this time, the drive torque calculation unit 2a calculates the speed ratio R from the engine speed Ne and the wheel speed Vt, and calculates the drive torque Td by multiplying the speed ratio R by the engine torque Te. Further, the determination unit 3 determines whether or not the driving torque Td is in a range of Tmin or more and Tmax or less.

Here, if Tmin ≦ Td ≦ Tmax, it is determined that the vehicle 10 is in a static running state, and the process proceeds to step S22. That is, it is determined that the posture of the vehicle 10 in the pitch direction maintains the posture at the time of stopping, and the vehicle 10 is in a stable running state, and the optical axis control is performed.
On the other hand, if Tmin ≦ Td ≦ Tmax is not satisfied, it is determined that the vehicle 10 is in the dynamic running state, and the process proceeds to step S34. That is, in this case, it is determined that the vehicle 10 is in a relatively unstable traveling state in which the attitude of the vehicle 10 is dynamically changed, and the optical axis control is prohibited.

[4. effect]
In the on-vehicle headlamp optical axis control device 1 described above, when determining the optical axis control start condition, the traveling state of the vehicle 10 is recognized by distinguishing between a stationary traveling state and a dynamic traveling state. The static running state and the dynamic running state are discriminated based on whether or not the posture of the vehicle 10 in the pitch direction is stably maintained. Then, the value of the driving torque Td acting on the driving wheel is used to determine the posture in the pitch direction. As described above, by using the driving torque Td of the driving wheel as the determination condition for permitting or prohibiting the adjustment of the optical axis angle, it is possible to accurately determine the traveling state of the vehicle 10 suitable for performing the optical axis correction. Can do.

  For example, it is difficult to determine the state of high-speed constant speed driving (auto cruise) with the state determination method at the time of traveling using the engine speed Ne, but the method of this embodiment is a kind of static traveling state. The state of high-speed constant speed traveling can be accurately determined, and the state determination accuracy can be improved. Further, by referring to the value of the driving torque Td, it is possible to determine a traveling state in which the posture in the pitch direction can be changed at a low speed as when traveling on an uphill road or a downhill road.

  Therefore, it is possible to improve the determination accuracy of the traveling state in which the optical axis correction can be performed without imposing an excessive burden on the actuator 6, and light that further improves convenience while reducing the cost of the headlamp 5. Axis control can be implemented. In addition, the lifetime of parts such as the actuator 6 relating to the adjustment of the optical axis angle can be extended, and a good cost-effectiveness can be obtained by improving the balance between cost and convenience.

Further, in the above-described in-vehicle headlamp optical axis control device 1, when the value of the drive torque Td is Tmin ≦ Td ≦ Tmax, it is determined that the traveling state of the vehicle 10 is the static traveling state. In other words, by limiting the range of the value of the driving torque Td determined to be the static running state to a predetermined range, it is possible to consider the influence given to the posture of the vehicle 10 in the pitch direction without using the vehicle speed, the road surface gradient, or the like. This can improve the determination accuracy of the running state.
In addition, a change in posture due to acceleration / deceleration of the vehicle 10 and a change in posture due to the road surface gradient can be determined with the same logic, and the calculation configuration can be simplified. Thereby, the reliability of control can be improved.

  In addition, in the above-described in-vehicle headlamp optical axis control device 1, the driving torque Td is calculated based on the engine torque Te and the gear ratio R in the driving torque calculation unit 2 a. As described above, the value of the drive torque Td acting on the drive wheels can be grasped with high accuracy by the calculation based on the engine torque Te and the gear ratio R. Accordingly, it is possible to improve the determination accuracy of the traveling state of the vehicle 10 (for example, a gasoline vehicle) that travels using the engine 7 as a power source.

[5. Modified example]
In the above-described embodiment, an example in which the optical axis control device 1 is applied to a gasoline vehicle using the engine 7 as a drive source is illustrated, but an electric vehicle or a drive using a drive motor (such as an electric motor or a motor generator) as a drive source. Application to a hybrid vehicle using both a motor and an engine 7 and a diesel vehicle is also possible. When the optical axis control device 1 is applied to an electric vehicle, the driving torque Td of the vehicle 10 may be calculated based on the value of the motor torque Tm output from the traveling motor.

For example, it is conceivable that the drive torque calculation unit 2a calculates a rotation ratio (transmission ratio) between the traveling motor and the drive wheels, and multiplies the rotation ratio by the motor torque Tm as the drive torque Td. Motor torque Tm is A configuration may be received from the electronic control unit for controlling the traction motor, based on the depression amount of the accelerator operation amount theta _AC and the brake pedal detected by the accelerator sensor 15, the wheel speed Vt information, etc. Then, it may be calculated in the drive torque calculation unit 2a. Some electric vehicles that run using a running motor as a power source do not include a transmission between the running motor and drive wheels. In this case, the rotation ratio (gear ratio) is set to 1. Alternatively, the motor torque Tm may be calculated as the drive torque Td.

  Thus, the value of the drive torque Td acting on the drive wheel can be grasped with high accuracy by the calculation based on the motor torque Tm (or the calculation based on the motor torque Tm and the rotation ratio). Therefore, even in a vehicle that travels using the traveling motor as a power source, it is possible to improve the determination accuracy of the traveling state.

In the case of a hybrid vehicle, the sum of the torque on the engine side and the torque on the traveling motor side may be calculated by the drive torque calculator 2a as the drive torque Td.
Moreover, in the above-described embodiment, the values Tmax and Tmin, which are the determination threshold values for the static running state, are exemplified as positive and negative, respectively. However, specific settings of these values Tmax and Tmin are arbitrary. is there. In addition, since it is considered that the state where the drive torque Td is Td = 0 is the most stable running state, 0 (or a minute value close to 0) is included in the range of the driving torque Td determined as the static running state. It is preferable that

DESCRIPTION OF SYMBOLS 1 Optical axis control apparatus 2 Calculation part 2a Drive torque calculation part (drive torque calculation means)
2b Movement distance calculation unit 3 Discrimination unit (discrimination means)
4 Control unit (control means)
5 Headlamp 6 Actuator (Adjustment means)

Claims (5)

Adjusting means for adjusting the optical axis angle of the in-vehicle headlamp in the vertical direction;
Drive torque calculation means for calculating drive torque acting on the drive wheels of the vehicle;
Discrimination means for discriminating whether the vehicle is in a static running state or a dynamic running state based on the driving torque;
The adjustment means permits the adjustment of the optical axis angle when the vehicle is determined to be in the static running state, and prohibits the adjustment when the vehicle is determined to be in the dynamic running state. An on-vehicle headlamp optical axis control device comprising a control means. The determination means determines that the vehicle is in the static running state when the value of the driving torque is within a predetermined range set in advance, and determines that the vehicle is in the dynamic running state otherwise. The optical axis control device for an in-vehicle headlamp according to claim 1. 3. The drive torque calculation unit according to claim 1, wherein the drive torque calculation unit calculates the drive torque based on a speed ratio between the engine and the drive wheels and an engine torque output from the engine. In-vehicle headlamp optical axis control device. The optical axis of the in-vehicle headlamp according to any one of claims 1 to 3, wherein the driving torque calculating means calculates the driving torque based on a motor torque output from a traveling motor. Control device. 5. The optical axis of an in-vehicle headlamp according to claim 4, wherein the driving torque calculating means calculates the driving torque based on a speed ratio between the driving motor and the driving wheel and the motor torque. Control device.

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