Optical axis adjustment device

Abstract

To calculate and adjust a deviation of an optical axis due to temperature variation around a vehicular headlamp.SOLUTION: An optical axis adjusting device adjusts an optical axis of a headlamp unit mounted on a vehicle. The optical axis adjusting device for a vehicular headlamp includes an engine temperature acquisition part which acquires a temperature within an engine room of the vehicle, a displacement amount calculation part which calculates a displacement amount of the optical axis based on the temperature, a speed information acquisition part which acquires speed information including a travel speed and a travel time of the vehicle, and an optical axis adjusting part which adjusts the optical axis of the headlamp unit on the basis of the displacement amount and the speed information.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an optical axis adjustment device for adjusting the optical axis of a vehicle headlamp provided in a vehicle.

Background Art

[0002] The optical axis of a vehicle headlamp is adjusted so that it is located within a range defined by regulations. As an optical axis adjustment device for adjusting the optical axis of a vehicle headlamp, for example, an auto-leveling device that adjusts the optical axis according to the inclination angle when the angle of the vehicle body in the front-rear direction is inclined with respect to the horizontal direction is known (Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, during the running of a vehicle, the temperature around and inside the vehicle headlamp changes due to the surrounding environment and the running conditions of the vehicle, and a deviation may occur in the optical axis due to the temperature change. Specifically, due to the temperature change, thermal expansion occurs in the housing of the vehicle headlamp, causing the vehicle headlamp itself to shift with respect to the vehicle body, or thermal expansion occurs in the light source unit housed inside the housing of the vehicle headlamp, causing the light source unit to shift with respect to the housing. Due to such a shift, the optical axis of the vehicle headlamp may deviate from within a predetermined range.

[0005] However, in the auto-leveling device of Patent Document 1 described above, adjustment of the optical axis deviation due to temperature change is not assumed. In recent years, with the high definition of light sources (LEDs) used in vehicle headlamps and the spread of high-function vehicle headlamps such as ADB (Adaptive Driving Beam), more accurate optical axis adjustment has been desired.

[0006] The present invention aims to address such a situation. That is, it aims to calculate and adjust the deviation of the optical axis caused by temperature changes around the vehicle headlamp, etc.

Means for Solving the Problems

[0007] To solve such problems, the optical axis adjustment device according to the present invention has the following configuration. That is, one aspect of the present invention is an optical axis adjustment device for adjusting the optical axis of a headlamp unit mounted on a vehicle, comprising an engine temperature acquisition unit that acquires the temperature in the engine room of the vehicle, a displacement amount calculation unit that calculates the displacement amount of the optical axis based on the temperature, a speed information acquisition unit that acquires speed information including the traveling speed and traveling time of the vehicle, and an optical axis adjustment unit that adjusts the optical axis of the headlamp unit based on the displacement amount and the speed information. An optical axis adjustment device for a vehicle headlamp is provided.

Effects of the Invention

[0008] According to the optical axis adjustment device having such characteristics, it is possible to calculate the deviation of the optical axis caused by temperature changes around the vehicle headlamp and correct or adjust it with high precision.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same reference numerals in different drawings indicate parts having the same function, and redundant descriptions in each drawing will be omitted as appropriate.

[0011] As shown in FIG. 1, the optical axis adjustment device mounted on the vehicle according to the embodiment of the present invention functions as a part of the vehicle control system 1 and is provided in the vehicle 100. The vehicle control system 1 includes various electronic devices necessary for the running of the vehicle 100 and a plurality of in-vehicle ECUs (Electronic Control Units) for controlling these electronic devices. Each electronic device and each in-vehicle ECU are communicably connected to each other by an in-vehicle network 3 such as CAN (Controller Area Network) or LIN (Local Interconnect Network), and are connected to a central gateway (CGW) 4 as a relay device to constitute the vehicle control system 1.

[0012] Each in-vehicle ECU can be configured to include a processor such as a CPU (Central Processing Unit) or an MPU (Micro Processing Unit), an electric circuit, and a storage element such as a RAM (Random Access Memory) or a ROM (Read Only Memory). Further, part or all of the operations executed by the in-vehicle ECU can also be realized by hardware such as an ASIC (application specific integrated circuit), an FPGA (field-programmable gate array), or a GPU (Graphics Processing Unit). In the following description, detailed descriptions and illustrations of electronic devices and the like that are not directly related to the optical axis adjustment device (optical axis adjustment ECU 11) according to the present embodiment will be omitted.

[0013] As shown in FIG. 1, the vehicle control system 1 is configured to include, as in-vehicle ECUs, an optical axis adjustment ECU 11, an engine ECU 21, a brake ECU 31, a steering ECU 41, an air conditioning ECU 51, and a wiper ECU 61. Each in-vehicle ECU is connected to an electronic device that is a control target of the in-vehicle ECU, and controls the operation of the connected electronic device based on information (data) acquired from the in-vehicle network 3. Further, each in-vehicle ECU outputs information indicating a state such as the operation state of the connected electronic device to the in-vehicle network 3.

[0014] The optical axis adjustment ECU 11 is connected to a headlight unit 13 provided in front of the vehicle and a drive unit 12 that drives the headlight unit 13, and functions as an optical axis adjustment device that adjusts the optical axis of the headlight unit. Details of the optical axis adjustment ECU 11 will be described later.

[0015] The engine ECU 21 is connected to the engine, the brake ECU 31 is connected to the brake, and the steering ECU 41 is connected to the steering. Then, the engine ECU 21, the brake ECU 31, and the steering ECU 41 control the running of the vehicle based on the information acquired from the in-vehicle network 3.

[0016] In particular, the engine ECU 21 is connected to an oil temperature sensor 22, a coolant water temperature sensor 23, an engine rotation sensor 24, and a vehicle speed sensor 25. The oil temperature sensor 22 detects the oil temperature of the engine during running and outputs it to the engine ECU 21. The coolant water temperature sensor 23 detects the temperature of the engine coolant water during running and outputs it to the engine ECU 21. The engine rotation sensor 24 detects the rotation speed of the engine from, for example, an ignition pulse or the like and outputs it to the engine ECU 21. The vehicle speed sensor 25 detects the running speed of the vehicle and outputs it to the engine ECU 21.

[0017] In addition, the engine ECU 21, the brake ECU 31, and the steering ECU 41 each obtain state information indicating the state of the electronic device (for example, information regarding torque, accelerator opening, vehicle running speed and running time, fuel consumption, amount of depression of the foot brake, on / off of the side brake, steering angle and steering amount of the steering, etc.) from the electronic devices connected thereto, and output the obtained information to the in-vehicle network 3.

[0018] The air-conditioning ECU 51 is connected to an outside air temperature sensor 52 attached to the outside of the vehicle, and controls an air-conditioning unit (not shown) based on the outside air temperature acquired from the outside air temperature sensor 52 and the information acquired from the in-vehicle network 3. That is, the air-conditioning ECU 51 controls the air-conditioning unit so that the temperature inside the vehicle compartment becomes the desired temperature set by the user while referring to the outside air temperature acquired from the outside air temperature sensor 52.

[0019] The wiper ECU 61 is connected to, for example, a raindrop sensor 62 that detects the amount of rainfall by the amount of raindrops adhering to the windshield, and operates the wiper at a predetermined time interval according to the amount of raindrops acquired from the raindrop sensor 62. Alternatively, the wiper ECU 61 operates the wiper according to the information based on the operation by the vehicle occupants acquired via the in-vehicle network 3.

[0020] (Regarding the optical axis adjustment device) Hereinafter, the optical axis adjustment ECU 11 as the optical axis adjustment device will be described. The optical axis adjustment ECU 11 controls the drive unit 12 with reference to the information acquired from each of the above-described in-vehicle ECUs via the in-vehicle network 3, and adjusts the optical axis of the light irradiated from the headlight unit 13 so as to be positioned within a predetermined range.

[0021] As shown in FIG. 2, the optical axis adjustment ECU 11 includes a CPU (Central Processing Unit) 111, a ROM 112, and a RAM 113. The CPU 111 executes various processes based on the programs stored in the ROM 112. In the present embodiment, the CPU 111 reads the programs stored in the ROM 112 into a memory such as the RAM 113 and executes them, thereby functioning as the engine temperature acquisition unit 114, displacement amount calculation unit 115, speed information acquisition unit 116, and optical axis adjustment unit 117 shown in FIG. 2. Hereinafter, the engine temperature acquisition unit 114, displacement amount calculation unit 115, speed information acquisition unit 116, and optical axis adjustment unit 117 will be described.

[0022] The engine temperature acquisition unit 114 acquires, as the temperature inside the engine room, the engine oil temperature detected by the oil temperature sensor 22 or the coolant temperature of the engine detected by the coolant water temperature sensor 23 via the engine ECU 21 and the in-vehicle network 3. The engine temperature acquisition unit 114 may predict the temperature inside the engine room based on the engine speed acquired from the engine rotation sensor 24.

[0023] The displacement amount calculation unit 115 calculates the displacement amount (deviation amount) of the optical axis of the headlight unit based on the temperature inside the engine room acquired by the engine temperature acquisition unit 114. For example, the displacement amount calculation unit 115 stores, in advance, in the ROM 112 or the like, a calculation formula for calculating the displacement amount corresponding to the temperature inside the engine room or a table in which the temperature inside the engine room and the displacement amount are associated with each other, and calculates based on this. It is preferable to acquire the calculation formula or the table in advance by simulation or the like for each vehicle.

[0024] The speed information acquisition unit 116 acquires speed information including the traveling speed detected from the speed sensor 25 and the traveling time at that traveling speed. Since the vehicle is affected by the traveling wind during traveling, the periphery of the headlight unit 13 can also be cooled by the traveling wind from the outside of the vehicle. Therefore, since the degree of cooling varies depending on the traveling speed and traveling time of the vehicle, the speed information acquisition unit 116 acquires the speed information. Further, since the influence of the traveling wind also varies depending on the outside air temperature and the degree of cooling in the headlight unit 13 changes, it is preferable to acquire the outside air temperature from the outside air temperature sensor 52.

[0025] The optical axis adjustment unit 117 determines the adjustment amount of the headlight unit 13 based on the displacement amount calculated by the displacement amount calculation unit 115, and outputs a drive signal indicating the adjustment amount to the drive unit 12. Further, when speed information is acquired by the speed information acquisition unit 116, the optical axis adjustment unit 117 corrects the displacement amount calculated by the displacement amount calculation unit 115 based on the speed information, and determines the adjustment amount of the headlight unit 13 according to the corrected displacement amount, and outputs a drive signal indicating the adjustment amount to the drive unit 12.

[0026] Also, when the traveling speed indicated by the speed information is equal to or higher than a predetermined first speed, the optical axis adjustment unit 117 does not output a drive signal to the drive unit 12 so as not to adjust the optical axis of the headlight unit 13. This is considered in view of the fact that when the traveling speed is the predetermined first speed, the periphery of the headlight unit 13 is sufficiently cooled and there is no need for optical axis adjustment.

[0027] Similarly, when the traveling speed indicated by the speed information is equal to or higher than a predetermined second speed and the vehicle has traveled at this second speed for a predetermined time or more, the optical axis adjustment unit 117 does not output a drive signal to the drive unit 12 so as not to adjust the optical axis of the headlight unit 13. This is considered in view of the fact that when the vehicle has traveled at the predetermined second speed for a predetermined time, the periphery of the headlight unit 13 is sufficiently cooled and there is no need for optical axis adjustment. Therefore, it is preferable to predetermine the time for sufficiently cooling the periphery of the headlight unit 13 for each vehicle as the first speed, the second speed, and the predetermined time.

[0028] (Regarding the headlight unit) Subsequently, the headlight unit 13, which is the object of optical axis adjustment by the optical axis adjustment ECU 11, will be described with reference to FIGS. 3 to 5.

[0029] The headlight unit 13 is usually provided in a pair on the left and right in front of the vehicle. However, only one of them is shown as a representative example in FIGS. 3 to 5. As shown in FIGS. 3 to 5, the headlight unit 13 is configured by housing, for example, a light source (not shown), a reflector that guides the light emitted from the light source to the front of the vehicle, a lens for distributing the light emitted from the light source within a predetermined range, etc. in a housing.

[0030] The headlight unit 13 is fixed to the bracket 14 and attached to the vehicle body 80 via the bracket 14. The bracket 14 is attached to the vehicle body 80 by a ball joint 141 provided at the upper part of the bracket 14, an aiming screw 142 for left - right adjustment, and an aiming screw 144 for up - down adjustment provided via a retainer 143 at the lower part of the bracket 14.

[0031] One end of the ball joint 141 is attached to the bracket 14 such that the ball portion 141A at one end serves as the swing center (fulcrum) of the bracket 14, and the screw portion 141B at the other end is attached to the vehicle body 80.

[0032] One end of the aiming screw 144 for up - down adjustment is attached to the bracket 14 via the retainer 143, and the other end is attached to the up - down aiming adjustment gear 146 of the leveling unit 145 on the vehicle body 80 side.

[0033] In this way, the headlight unit 13 is supported so as to be tiltable up and down together with the bracket 14 with respect to the vehicle body 80 with the ball portion 141A at one end of the ball joint 141 as a fulcrum as the aiming screw 144 for up - down adjustment or the retainer 143 moves in the vehicle's front - rear direction.

[0034] That is, by rotating the aiming screw 144 for up - down adjustment, the retainer 143 moves in the vehicle's front - rear direction, and as the retainer 143 moves, the lower part of the bracket 14 also moves in the vehicle's front - rear direction. Thereby, the headlight unit 13 rotates and tilts about the ball portion 141A of the ball joint 141.

[0035] When adjusting the optical axis of the headlight unit 13, it can be manually adjusted by an operator or automatically adjusted by the optical axis adjustment ECU 11. In the case of manual adjustment by an operator, when the operator rotates the aiming screw 144 for vertical adjustment with a driver, the retainer 143 moves in the vehicle longitudinal direction at the screw portion of the aiming screw 144 for vertical adjustment. Along with the movement of the retainer 143, the lower part of the bracket 14 also moves in the vehicle longitudinal direction. As a result, the headlight unit 13 together with the bracket 14 rotates and tilts about the ball portion 141A of the ball joint 141.

[0036] In the case of automatic adjustment by the optical axis adjustment ECU 11, the drive unit 12 (for example, a motor) included in the leveling unit 145 is driven to rotate the aiming screw 144 for vertical adjustment together with the vertical aiming adjustment gear 146. By the drive unit 12 rotating the aiming screw 144 for vertical adjustment, the aiming screw 144 for vertical adjustment moves in the vehicle longitudinal direction, and accordingly, the retainer 143 also moves in the vehicle longitudinal direction. As a result, the headlight unit 13 together with the bracket 14 rotates and tilts about the ball portion 141A of the ball joint 141.

[0037] The optical axis adjustment ECU 11 according to the present embodiment performs optical axis adjustment on the headlight unit 13 configured as described above as follows. Since the headlight unit 13 is attached near the engine of the vehicle body 80, it is easily affected by temperature changes in the engine compartment during driving and is likely to cause thermal expansion and the like. Therefore, in the optical axis adjustment ECU 11 , E the engine temperature acquisition unit 114 acquires the engine oil temperature detected by the oil temperature sensor 22 or the cooling water temperature of the engine detected by the cooling water temperature sensor 23 as the temperature in the engine compartment, and estimates the temperature around the headlight unit near the engine.

[0038] The displacement calculation unit 115 calculates the displacement amount of the optical axis according to the acquired temperature inside the engine room from the calculation formula stored in the ROM 112 and outputs the calculated displacement amount to the optical axis adjustment unit 117. The speed information acquisition unit 116 outputs speed information including the traveling speed acquired from the vehicle speed sensor 25 and the time traveled at the traveling speed to the optical axis adjustment unit 117.

[0039] The optical axis adjustment unit 117 calculates the adjustment amount of the headlight unit 13 based on the displacement amount calculated by the displacement calculation unit 115 and outputs a drive signal indicating the adjustment amount to the drive unit 12. At this time, if there is speed information, the displacement amount is corrected according to the speed information, the adjustment amount of the headlight unit 13 based on the corrected displacement amount is calculated, and a drive signal indicating the adjustment amount is output to the drive unit 12.

[0040] Also, when the speed information is equal to or higher than a predetermined first speed or when traveling at a speed equal to or higher than a second speed for a predetermined time, etc., the optical axis adjustment unit 117 does not output a drive signal to the drive unit 12 and does not perform optical axis adjustment. Note that the optical axis adjustment unit 117 may correct the displacement amount based on the outside air temperature acquired from the outside air temperature sensor 52 and the rainfall amount acquired from the rain drop sensor 62 as necessary.

[0041] The drive unit 12 rotates the up-down adjustment aiming screw 144 based on the drive signal from the optical axis adjustment unit 117 and moves it by the amount of adjustment in the front-rear direction with respect to the vehicle body 80. As the up-down adjustment aiming screw 144 moves, the retainer 143 also moves in the front-rear direction of the vehicle body 80 by the amount of adjustment calculated by the displacement calculation unit 115, and the bracket 14 rotates and tilts around the ball portion 141A. Thereby, the headlight unit 13 supported by the bracket can tilt up and down with respect to the vehicle body 80, and the position of the optical axis can be adjusted according to the displacement amount of the optical axis calculated by the displacement calculation unit 115.

[0042] Thus, according to this embodiment, while estimating the temperature inside the engine room and considering the temperature change due to the running wind caused by the running speed of the vehicle, the displacement (deviation) of the optical axis of the headlamp unit 13 based on the temperature rise is predicted. Therefore, the deviation of the optical axis caused by the temperature change around the vehicle headlamp can be calculated in advance or in real time and adjusted with high precision.

[0043] The embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to these embodiments, and design changes and the like within the scope not departing from the gist of the present invention are also included in the present invention. In addition, the above-described embodiments can be combined by diverting each other's technologies as long as there are no particular contradictions or problems in their purposes and configurations.

Explanation of Reference Numerals

[0044] 1: Vehicle control system, 3: In-vehicle network, 11: Optical axis adjustment ECU (optical axis adjustment device), 12: Driving unit, 13: Headlamp unit, 14: Bracket, 21: Engine ECU, 22: Oil temperature sensor, 23: Cooling water temperature sensor, 24: Engine rotation sensor, 25: Cooling device, 31: Brake ECU, 41: Steering ECU, 51: Air conditioning ECU, 52: Outside air temperature sensor, 61: Wiper ECU, 62: Raindrop sensor, 80: Vehicle body, 100: Vehicle, 114: Engine temperature acquisition unit, 115: Displacement amount calculation unit, 116: Speed information acquisition unit, 117: Optical axis adjustment unit, 141: Ball joint, 141A: Ball part, 141B: Screw part, 142: Aiming screw for left-right adjustment, 143: Retainer, 144: Aiming screw for up-down adjustment, 145: Leveling unit, 146: Up-down aiming adjustment gear

Claims

1. An optical axis adjustment device for adjusting the optical axis of a headlight unit mounted on a vehicle, comprising: an engine temperature acquisition unit that acquires the temperature inside the engine compartment of the vehicle; a displacement amount calculation unit that calculates the displacement amount of the optical axis based on the temperature; a speed information acquisition unit that acquires speed information including the traveling speed and traveling time of the vehicle; an optical axis adjustment unit that calculates the adjustment amount of the optical axis based on the displacement amount and outputs a drive signal corresponding to the adjustment amount to a drive unit that drives the headlight unit to adjust the optical axis; The optical axis adjustment device for a vehicle headlight, wherein the optical axis adjustment unit corrects the displacement amount based on the speed information and calculates the adjustment amount based on the corrected displacement amount.

2. The optical axis adjustment device according to claim 1, wherein the optical axis adjustment unit does not output a drive signal to the headlight unit when the traveling speed is equal to or higher than a predetermined first speed.

3. The optical axis adjustment device according to claim 1, wherein the optical axis adjustment unit does not output a drive signal to the headlight unit when the vehicle travels at a speed equal to or higher than a predetermined second speed for a predetermined time or longer.

4. The engine temperature acquisition unit acquires the temperature inside the engine compartment based on at least one of the oil temperature of the engine during traveling, the water temperature of the engine cooling water during traveling, and the engine speed. The optical axis adjustment device according to any one of claims 1 to 3.

Images