JP2014080108A - Vehicular headlamp control unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicular headlamp control unit capable of suppressing erroneous estimation of a displacement quantity of a pitch angle.SOLUTION: A vehicular headlamp control unit according to the present invention includes: a vehicle height sensor 1 that detects a displacement quantity of a vehicle height; a pitch angle calculation unit 21 that calculates a pitch angle of a headlamp 9 on the basis of the displacement quantity that is an output of the vehicle height sensor 1; and an optical-axis direction adjustment unit 22 that adjusts the optical-axis direction of the headlamp 9 on the basis of the pitch angle calculated by the pitch angle calculation unit 21. The pitch angle calculation unit 21 calculates the pitch angle on the basis of function data F of the pitch angle in relation to a pre-set displacement quantity. The function data F specifies change intervals A1 and A2 in which the pitch angle changes along with a change in the displacement quantity, and a no-change interval B in which the pitch angle does not change along with the change in the displacement quantity. The no-change interval B is an interval that encompasses an initial displacement quantity c1 which is an output of the vehicle height sensor 1 under an initial condition, and is designated on a side of displacement quantities smaller than at least the initial displacement quantity c1.

Description

  The present invention relates to a vehicle headlamp control device.

  As described in Japanese Patent Laid-Open No. 9-286274, the headlamp control device is arranged in the direction of the optical axis of the vehicle headlamp from the output of one vehicle height sensor arranged at the front or rear of the vehicle. A control device has been developed that estimates the tilt angle (pitch angle) with respect to the horizontal plane and adjusts the pitch angle of the headlamps based on the tilt angle. As a result, it is possible to adjust the pitch angle of the headlamps so as not to give glare to the oncoming vehicle without installing vehicle height sensors at both the front and rear of the vehicle, thereby reducing manufacturing costs. It became.

JP-A-9-286274

  By the way, in the installation work of the vehicle height sensor to the vehicle in the production factory, the vehicle height sensor is initialized under a predetermined condition after the installation because of concern about variations in the attachment to the suspension. The predetermined condition is, for example, a state in which one driver is on board, a state in which no one is on board, or a state in which a driver and a passenger on the passenger seat are on board.

  Here, when initializing the vehicle height sensor at a production plant or the like, the suspension is not familiar, and the front and rear suspensions may be familiar to the same extent (for example, sinking) by the time they enter the market. . Since the front and rear suspensions are accustomed to the same extent, there is no change in the pitch angle due to familiarity, but the value of the vehicle height sensor is changed by the familiarity. As a result, an incorrect pitch angle may be estimated.

  This invention is made in view of such a situation, and it aims at providing the vehicle headlamp control apparatus which can suppress the incorrect estimation of the pitch angle after familiarity.

  In order to achieve the above object, an invention according to claim 1 is a vehicle headlight control device, which is disposed at a front portion or a rear portion of a vehicle and detects a displacement amount of a vehicle height (1 ) And a displacement angle that is an output from the vehicle height sensor (1), a pitch angle calculation unit that calculates a pitch angle that is an inclination angle of the headlamp (9) of the vehicle with respect to the horizontal plane in the optical axis direction ( 21) and an optical axis direction adjusting unit (22) for adjusting the optical axis direction of the headlamp (9) based on the pitch angle calculated by the pitch angle calculating unit (21), and the pitch An angle calculation unit (21) calculates the pitch angle based on the function data (F) of the pitch angle with respect to the preset amount of displacement, and the function data (F) corresponds to the change in the amount of displacement. Change intervals (A1, A2) in which the pitch angle changes, and changes in the displacement amount. The non-change section (B) in which the pitch angle does not change, and the non-change section (B) is an initial displacement that is an output of the vehicle height sensor (1) under a condition to be initialized. The section includes the amount (c1) and is set to the side where the displacement is smaller than at least the initial displacement (c1).

  According to this configuration, since the predetermined section including the displacement amount under the initialization condition in the function data is set as the non-change section, the change in the output value (displacement amount) due to the familiarity of the suspension is absorbed. That is, even when the output value of the vehicle height sensor changes due to the familiarity of the suspension, the pitch angle calculation unit is prevented from calculating an incorrect pitch angle due to the change.

  In addition, the code | symbol in the bracket | parenthesis of each means described in this column and the claim shows the correspondence with the specific means as described in embodiment mentioned later.

It is a block diagram which shows the structure of the vehicle headlamp control apparatus of this embodiment. It is a block diagram which shows the structure of the headlamp of this embodiment. It is a figure which shows the function data of this embodiment. It is a flowchart which shows the control flow of the vehicle headlamp control apparatus of this embodiment. It is explanatory drawing for demonstrating calculation of the pitch angle in the acceleration state of this embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Each figure used for explanation is a conceptual diagram, and the shape of each part may not necessarily be exact.

  As shown in FIG. 1, the vehicle headlamp control device of the present embodiment includes a vehicle height sensor 1 and an ECU 2. The vehicle height sensor 1 is a height sensor attached to an axle on the driver seat side or the passenger seat side at the rear of the vehicle. The vehicle height sensor 1 measures a relative displacement amount (vehicle height displacement amount) between the rear wheel axle and the vehicle body, and outputs it to the ECU 2 as a rear height value (rear wheel side vehicle height displacement amount) HR. .

  The ECU 2 is an electronic control unit having a CPU, a ROM, a RAM, an input / output circuit (not shown), and the like. The ECU 2 includes a pitch angle calculation unit 21 and an optical axis direction adjustment unit 22 realized by the CPU or the like. The pitch angle calculation unit 21 calculates a pitch angle that is an inclination angle with respect to a horizontal plane in the optical axis direction of the headlamp 9 of the vehicle based on an output from the vehicle height sensor 1. Specifically, the pitch angle calculation unit 21 includes a storage unit (ROM) 21 a in which function data F is stored. Based on the output value (displacement amount) of the vehicle height sensor 1 and the function data F, the pitch angle calculation unit 21 Calculate the corner. The pitch angle estimation and function data F will be described later.

  The optical axis direction adjustment unit 22 adjusts the optical axis direction of the headlamp 9 up and down based on the pitch angle calculated by the pitch angle calculation unit 21. Specifically, the optical axis direction adjusting unit 22 controls an actuator 95 that can adjust the optical axis direction of the headlamp 9 to be described later, and adjusts the optical axis direction of the headlamp 9 up and down. The ECU 2 can also be said to be a leveling ECU that adjusts the optical axis direction in the vertical direction.

  The headlamp 9 is a general headlight, and as shown in FIG. 2, the lamp 91, the reflector 92 that fixes the lamp 91, and the reflector 92 are moved in the vertical direction of the arc (in the direction of the arrow in the figure). One supporting portion 93 that is movably supported, the other movable portion 94 that supports the reflector 92 and is movable, and an actuator 95 that includes a step motor or the like that drives the movable portion 94 in the front-rear direction. . In the present embodiment, the optical axis direction of the headlamp 9 is initially set on the assumption that one driver has boarded. That is, the vehicle headlamp control device of the present embodiment is initialized in a state where one driver is on the vehicle.

  Various sensor signals (throttle opening signal TA, vehicle speed signal VSP, etc.) from well-known throttle opening sensor z1, vehicle speed sensor z2, and other sensors arranged on the vehicle side are input to ECU2. These various sensor signals are used for mode determination such as the running state, stop state, acceleration state, and deceleration state of the vehicle.

  Here, the pitch angle estimation and the function data F when the vehicle is stopped will be described. The ECU 2 determines from the various sensor signals that the vehicle is stopped. It can be said that the ECU 2 has a mode determination unit (not shown). When the pitch angle calculation unit 21 receives the output signal from the vehicle height sensor 1 in the vehicle stop state, the pitch angle calculation unit 21 compares the output value with the function data F stored in the storage unit 21a. The pitch angle calculation unit 21 refers to the function data F and calculates a pitch angle corresponding to the received output value.

  As shown in FIG. 3, the function data F of the present embodiment is an approximate expression expressed in a map showing the relationship between “the output value of the vehicle height sensor 1” and “the pitch angle with respect to the output value calculated in advance”. It is. More specifically, the horizontal axis in FIG. 3 is the rear sinking amount corresponding to the output value of the vehicle height sensor 1 (the standard load state is 0 mm), and the vertical axis in FIG. 3 is the pitch angle (deg). .

  The function data F includes a first change section A1 and a second change section A2 in which the output value and the pitch angle are in a proportional relationship, and a non-change section B in which the pitch angle does not change with respect to a change in the output value. . The function data F in the change sections A1 and A2 is a proportional relationship in which the pitch angle changes to the plus side (the optical axis direction upwards) as the output value of the vehicle height sensor 1 changes to the minus side (the vehicle sinks side). It has become.

  The non-change section B is located between the change sections A1 and A2. The unchanged section B includes an output value c1 under the condition to be initialized (that is, the state when one driver is in the present embodiment). The non-change section B is set on both sides of the output value c1 (a smaller displacement amount side and a larger displacement side). In the function data F in the non-change section B, the pitch angle does not change with respect to the change in the output value. That is, when the output value of the vehicle height sensor 1 is in the unchanged section B, the pitch angle calculation unit 21 calculates a constant pitch angle (initial pitch angle).

  In the present embodiment, the non-change section B is set to a section with an output value of −5 mm to −18 mm. All sections other than the non-change section B are set to the change sections (A1, A2). In the present embodiment, the output value c1 under the initialized condition is −10 mm. The pitch angle calculation unit 21 outputs the calculated pitch angle to the optical axis direction adjustment unit 22. In FIG. 3, the output value c <b> 2 is a displacement amount in a state where an occupant gets on the driver seat and the passenger seat. The output value c3 is a displacement amount in a state where four passengers (two in the front row and two in the rear row) are on board. The output value c4 is the amount of displacement in the state where the same four-passenger ride and the luggage are loaded on the trunk. The output value c5 is a displacement amount in a state where a load is placed on one trunk with a driver.

  The flow of headlamp control of the vehicle headlamp control apparatus of this embodiment will be described with reference to FIG. First, the ECU 2 determines the state (mode) of the vehicle from various sensor signals, and determines whether or not the vehicle is in a stopped state (S101). When the vehicle is in a stopped state (S101: Yes), the pitch angle calculation unit 21 compares the output value of the vehicle height sensor 1 with the function data F to calculate the pitch angle (S102). Based on the calculated pitch angle, the optical axis direction adjusting unit 22 drives the actuator 95 to adjust the optical axis direction so that the oncoming vehicle is not dazzled (S103).

  According to the vehicle headlamp control device of the present embodiment, function data F having a non-change section B is used for estimating the pitch angle. The output value of the vehicle height sensor 1 changes due to the suspension becoming familiar after vehicle production. However, according to the present embodiment, since the non-change section B is set in the section including the output value c1 under the initialization condition of the function data F, the change in the output value due to the familiarity of the suspension is absorbed. That is, due to the existence of the non-change section B, the pitch angles estimated before and after the familiarity match under the initialization condition (the state where one driver is on board). Thus, even when the output value of the vehicle height sensor 1 changes due to the familiarity of the suspension, the pitch angle calculation unit 21 is suppressed from calculating an incorrect pitch angle due to the change. It can be said that the non-change section B is a familiar section that absorbs the familiarity of the suspension.

  The section width of the non-change section B is 13 mm (−5 mm to −18 mm) in the above embodiment, but it is effective when it is 5 mm or more from the viewpoint of the familiarity, while 15 mm from the viewpoint of pitch angle calculation accuracy. The following is effective. That is, the width of the non-change section B is preferably 5 mm or more and 15 mm or less.

  The familiarity of the suspension may vary from vehicle type to vehicle type. However, as in the present embodiment, the output value c1 under the initialization condition is at both ends of the unchanged section B (maximum value and minimum value: in this embodiment − By setting other than 5 mm and −18 mm), the versatility of the vehicle headlamp control device is improved.

  It is sufficient that the non-change section B includes the output value c1 under the initialization condition and is set to the side where the displacement amount is smaller than at least the output value c1. In other words, the non-change section B only needs to be set so that the output value c1 under the initialization condition is included and the output value c1 is positioned other than the minimum value in the non-change section B. In addition, since the familiarity often changes to the sinking side (minus side), the output value c1 under the initialization condition is higher than the center value of the unchanged period B (the center value is changed to the center value). It is preferable that it is set so that it may be located.

  Here, the calculation of the pitch angle in cases other than the vehicle stop state will be described by taking the acceleration state as an example. In the acceleration state of the vehicle, as shown in FIG. 5, the front suspension 81 on the front wheel side is extended by the load movement toward the rear of the vehicle, and the rear suspension 82 on the rear wheel side is compressed. In the traveling state, it can be considered that there is no increase or decrease in the number of passengers or luggage and there is no change in the total load W of the vehicle. Therefore, the front height value HF on the front wheel side is estimated based on the rear height value HR of the vehicle height sensor 1 as follows. The front height value HF is a value as a relative displacement amount between the front wheel side axle and the vehicle body, and is a displacement amount of the front wheel side vehicle height.

When the spring constant (front wheel rate) of the front suspension 81 is KF and the spring constant (rear wheel rate) of the rear suspension 82 is KR, the load movement amount ΔW to the rear wheel side is calculated by the following equation (1). .
ΔW = HR × KR × 2 (1)
Here, the load movement amount on the front wheel side is −ΔW whose absolute value is equal to and opposite to the load movement amount ΔW to the rear wheel side, so the front height value HF is calculated by the following equation (2). In the formulas (1) and (2), the front wheel and the rear wheel have two left and right wheels, so the number is double (× 2).
HF = −ΔW / (KF × 2) = − (HR × KR) / KF (2)
Therefore, the pitch angle θ1, which is an inclination angle with respect to the preset reference plane BL in the longitudinal direction of the vehicle, is calculated by the following equation (3). L is the distance between the front and rear wheels.
θ1 = tan ⁻¹ {(HF−HR) / L} (3)
As a result, the target optical axis direction adjustment angle θ2 with respect to the headlamp 9 is set to θ2≈−θ1 that does not give dazzling light to the oncoming vehicle, and the actuator 95 is driven based on this angle θ2 to light the headlamp 9 The axial direction is adjusted. When the vehicle is in a decelerating state, the front suspension 81 is compressed and the rear suspension 82 is extended by moving the load forward of the vehicle, contrary to the acceleration state. Even in this case, the pitch angle θ1 and the target optical axis direction adjustment angle θ2 are calculated as described above.

Further, when there is a change in the rear height value HR even though it is determined that the vehicle is stopped, it is considered that there is a change in the loading state of the vehicle. At this time, since the fluctuation of the height value (the amount of displacement of the vehicle height) is mainly on the rear wheel side, the front height value HF is calculated from the rear height value HR by the following equation (4).
HF = HR × α (4)
Here, when α is 0, the fluctuation of the front height value is ignored, and α = 0 to about 2 depending on the specifications of the suspension. Then, the pitch angle θ1 and the target optical axis direction adjustment angle θ2 are calculated in the same manner as described above. Thus, ECU2 (pitch angle calculation part 21) calculates a pitch angle according to the state of a vehicle by the substitution calculation to function data F, a numerical formula, etc. A database calculated in advance using the above mathematical formula or the like may be used as function data.

  The pitch angle calculation unit 21 calculates the pitch angle based on pitch angle function data (including a database, a map, and an approximate expression) using the output value of the vehicle height sensor 1 as a variable even in a state other than the stop state. May be. Since the function data has the non-change section, the same effect as described above is exhibited.

  Thus, the calculation of the pitch angle by the pitch angle calculation unit 21 may be performed based on the output of the vehicle height sensor 1, and may be calculated with reference to the database regarding the pitch angle with respect to the output value. For example, the pitch angle calculation unit 21 may store a database of vehicle stop states and search for and determine the pitch angle corresponding to the output of the vehicle height sensor 1. In addition, when the output of the vehicle height sensor 1 is an output value not in the database, the pitch angle calculation unit 21 uses the average of the pitch angles corresponding to the values before and after the output value (the displacement amount of the vehicle height) as the pitch angle. It may be calculated. When the output value existing in the database is every 1 mm and the output value is 1.5 mm, the pitch angle calculation unit 21 calculates the average of the pitch angle at 1 mm and the pitch angle at 2 mm as the pitch angle. To do. Further, the function data F (approximate expression) of the change sections A1 and A2 is not limited to a proportional relationship, and may be any function that changes the pitch angle with respect to a change in output. Moreover, calculating the pitch angle is equivalent to calculating the displacement amount of the pitch angle, and detecting the displacement amount of the vehicle height is equivalent to detecting the vehicle height.

1: Vehicle height sensor ECU, 21: pitch angle calculation unit,
22: Optical axis direction adjustment unit, 81: Front suspension,
82: Rear suspension, 9: Headlight,
F: Function data, A1: First change section (change section),
A2: Second change section (change section), B: No change section, c1: Output value (initial displacement)

Claims (2)

A vehicle height sensor (1) that is arranged at the front or rear of the vehicle and detects the amount of displacement of the vehicle height;
A pitch angle calculation unit (21) that calculates a pitch angle that is an inclination angle with respect to a horizontal plane in the optical axis direction of the headlamp (9) of the vehicle based on an output from the vehicle height sensor (1);
An optical axis direction adjustment unit (22) for adjusting an optical axis direction of the headlamp (9) based on the pitch angle calculated by the pitch angle calculation unit (21);
With
The pitch angle calculation unit (21) calculates the pitch angle based on the function data (F) of the pitch angle with respect to the displacement amount set in advance,
The function data (F) includes a change interval (A1, A2) in which the pitch angle changes with respect to the change in the displacement amount, and a non-change interval (B) in which the pitch angle does not change with respect to the change in the displacement amount. And having
The non-change section (B) includes an initial displacement amount (c1) that is an output of the vehicle height sensor (1) under a condition to be initialized, and at least the displacement amount is greater than the initial displacement amount (c1). Vehicle headlamp control device set on the smaller side. 2. The vehicle headlamp control device according to claim 1, wherein the non-change section (B) is set on both sides where the displacement amount is smaller and larger than the initial displacement amount.

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