Control device for vehicle light fixture, ecu, vehicle light fixture system, computer program, and control method for vehicle light fixture

Abstract

A control device 36 calculates road surface angle information according to an output value of an inclination sensor 32 when a vehicle is stopped, and adjusts an irradiation direction according to vehicle posture angle information obtained from the output value of the inclination sensor 32 while the vehicle is stopped and the road surface angle information. The control device 36 executes first calculation processing in the calculation of the road surface angle information, and second calculation processing in which the time required for calculating the road surface angle information is shortened. When an ignition switch 314 is turned off before the end of the first calculation processing after the end of the second calculation processing, the control device 36 stores the road surface angle information obtained by the second calculation processing in a nonvolatile memory 40. When the ignition switch 314 is turned off after the end of the first calculation processing, the control device 36 stores the road surface angle information obtained by the first calculation processing in the nonvolatile memory 40.

Description

Vehicle lighting device control device, ECU, vehicle lighting system, computer program, and vehicle lighting control method

[0001] The present invention relates to a vehicle lighting control device, an ECU, a vehicle lighting system, a computer program, and a vehicle lighting control method.

[0002] Conventionally, there has been known an auto-leveling control that automatically changes the illumination direction of a vehicle headlight in accordance with the tilt angle of the vehicle. In general, in auto-leveling control, the illumination direction of the headlight is adjusted based on the pitch angle of the vehicle derived from the output value of a vehicle height sensor. In contrast, Patent Document 1 discloses a control device for a vehicle lamp that performs auto-leveling control using an inclination sensor such as an acceleration sensor.

[0003] JP 2012-030782 A

[0004] Using an inclination sensor can make the auto-leveling system less expensive and more lightweight than using a vehicle height sensor. However, even when using an inclination sensor, there is always a demand for more accurate auto-leveling control.

[0005] The present invention has been made in view of the above circumstances, and one of its objects is to provide a technique for improving the accuracy of auto-leveling control of vehicle lighting fixtures.

[0006] In order to solve the above problems, one aspect of the present invention is a control device for a vehicle lamp that controls an illumination direction of a vehicle lamp in the vertical direction of the vehicle in accordance with an output value of an inclination sensor. The control device calculates road surface angle information in accordance with the output value of the inclination sensor when the vehicle is stopped, adjusts the illumination direction in accordance with vehicle attitude angle information obtained from the output value of the inclination sensor while the vehicle is stopped and the road surface angle information, and executes a first calculation process that calculates the road surface angle information in accordance with an average value calculated from a plurality of output values ​​and a second calculation process that shortens the time required to calculate the road surface angle information compared to the first calculation process, stores the road surface angle information obtained by the second calculation process in a non-volatile memory when an ignition switch is turned off after the second calculation process but before the first calculation process is finished, and stores the road surface angle information obtained by the first calculation process in a non-volatile memory when the ignition switch is turned off after the first calculation process is finished.

[0007] Another aspect of the present invention is an ECU, which includes an inclination sensor, a nonvolatile memory, and the vehicle lamp control device of the above aspect.

[0008] Another aspect of the present invention is a vehicle lighting system, which includes a vehicle lighting device capable of changing the illumination direction in the vertical direction of the vehicle, and the ECU of the above aspect.

[0009] Another aspect of the present invention is a computer program executed by a control device for a vehicle lamp that controls an illumination direction of a vehicle lamp in the vertical direction of the vehicle in accordance with an output value of an inclination sensor. The computer program causes the control device for the vehicle lamp to perform functions of: calculating road surface angle information in accordance with the output value of the inclination sensor when the vehicle is stopped; adjusting the illumination direction in accordance with vehicle attitude angle information obtained from the output value of the inclination sensor while the vehicle is stopped and the road surface angle information; executing a first calculation process that calculates the road surface angle information in accordance with an average value calculated from a plurality of output values; and a second calculation process that shortens the time required to calculate the road surface angle information compared to the first calculation process; storing the road surface angle information obtained by the second calculation process in a nonvolatile memory when an ignition switch is turned off after the second calculation process but before the first calculation process is completed; and storing the road surface angle information obtained by the first calculation process in the nonvolatile memory when the ignition switch is turned off after the first calculation process is completed.

[0010] Another aspect of the present invention is a method for controlling a vehicle lamp that controls an illumination direction of the vehicle lamp in the vertical direction of the vehicle in accordance with an output value of an inclination sensor. The control method includes: calculating road surface angle information in accordance with the output value of the inclination sensor when the vehicle is stopped; adjusting the illumination direction in accordance with vehicle attitude angle information obtained from the output value of the inclination sensor while the vehicle is stopped and the road surface angle information; performing a first calculation process to calculate the road surface angle information in accordance with an average value calculated from a plurality of output values; and a second calculation process that shortens the time required to calculate the road surface angle information compared to the first calculation process; storing the road surface angle information obtained by the second calculation process in a nonvolatile memory when an ignition switch is turned off after the second calculation process but before the first calculation process is completed; and storing the road surface angle information obtained by the first calculation process in a nonvolatile memory when the ignition switch is turned off after the first calculation process is completed.

[0011] Any combination of the above components and conversion of the present invention into a method, device, system, etc. are also valid aspects of the present invention.

[0012] According to the present invention, the accuracy of auto-leveling control of a vehicle lamp can be improved.

[0013] FIG. 5 is a cross-sectional view of a vehicle lamp. FIG. 6 is a functional block diagram illustrating the operational coordination between a vehicle lamp, a leveling ECU, and a vehicle control ECU. FIG. 7 is a schematic diagram illustrating an acceleration vector generated in a vehicle and an inclination angle of the vehicle that can be detected by an inclination sensor. FIG. 8 is a diagram illustrating the running state of a vehicle and the calculation timing of a road surface angle. FIG. 9 (A) and FIG. 9 (B) are diagrams illustrating a first calculation process and a second calculation process. FIG. 9 is a flowchart of auto-leveling control.

[0014] The present invention will be described below with reference to the drawings based on preferred embodiments. The embodiments are illustrative and do not limit the invention, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention. The same or equivalent components, parts, and processes shown in the drawings are designated by the same reference numerals, and redundant descriptions are omitted where appropriate. The scale and shape of each part shown in the drawings are set for convenience to facilitate explanation and should not be interpreted as limiting unless otherwise specified. Furthermore, when terms such as "first" and "second" are used in this specification or claims, unless otherwise specified, these terms do not indicate any order or importance, but are used to distinguish one configuration from another. Furthermore, some components that are not important for explaining the embodiments are omitted in the drawings.

[0015] In the present disclosure, "while the vehicle is moving" refers to, for example, the period from when the output value of the vehicle speed sensor 308, which will be described later, exceeds 0 until the output value of the vehicle speed sensor 308 becomes 0 again. "When the vehicle is stopped" refers to, for example, the period from when the output value of the vehicle speed sensor 308 becomes 0 until the output value of the tilt sensor 32, which will be described later, becomes stable. "While the vehicle is stopped" refers to, for example, the period from when the output value of the tilt sensor 32 becomes stable until the output value of the vehicle speed sensor 308 becomes greater than 0. "When stable" refers to the state in which the difference ΔA between the second average value A2 and the first average value A1 remains within a predetermined range R1 for a third predetermined time T3, as will be described later.

[0016] Furthermore, in the present disclosure, "vehicle 300 is stopped" means that vehicle 300 is in a state of "when the vehicle is stopped" or "while the vehicle is stopped." "Immediately after starting" refers to, for example, a predetermined time from when the output value of vehicle speed sensor 308 exceeds 0. "Just before starting" refers to, for example, a predetermined time before when the output value of vehicle speed sensor 308 exceeds 0. "While the vehicle is running," "when the vehicle is stopped," "while the vehicle is stopped," "when stable," "just after starting," "just before starting," and "predetermined time" can be set as appropriate based on the designer's empirical knowledge or experiments, simulations, etc., performed by the designer.

[0017] 1 is a cross-sectional view of an example vehicle lamp 1. The vehicle lamp 1 has a lamp body 2 having a recess that opens toward the front of the vehicle, and a translucent cover 4 that covers the opening of the lamp body 2. The lamp body 2 and the translucent cover 4 form a lamp chamber 6. The lamp chamber 6 houses an optical unit 8.

[0018] The optical unit 8, as an example, is a scanning optical pattern forming device that scans the area ahead of the vehicle with light from a light source. The optical unit 8 includes a light source 10, a condensing lens 12, a rotating reflector 14, a projection lens 16, and a heat sink 18. The light source 10 has a structure in which a plurality of light-emitting elements 10b are arranged in an array on a circuit board 10a. Each light-emitting element 10b is configured to be able to be turned on and off individually. The light-emitting elements 10b may be semiconductor light-emitting elements such as LEDs, ELs, and LDs. Note that the light source 10 may also be an incandescent bulb, a halogen lamp, a discharge bulb, or the like. The light source 10 is fixed to a surface of the heat sink 18 facing the rotating reflector 14. Heat from the light source 10 is conducted to the heat sink 18, thereby cooling the light source 10.

[0019] The focusing lens 12 focuses the light L emitted from the light source 10 and directs it toward the blades 14a of the rotating reflector 14. The rotating reflector 14 has multiple blades 14a. The multiple blades 14a function as reflective surfaces for the light L and are fixed to the circumferential surface of a rotating barrel 14b. The rotating barrel 14b is fixed to the output shaft of a motor 14c. When the motor 14c is driven, the blades 14a rotate in one direction around the rotation axis R. As the blades 14a rotate, they reflect the light L, scanning the area in front of the lamp with the light L. This allows a desired light distribution pattern to be formed in front of the lamp. For example, by combining the turning on and off of the light source 10 and the rotation of the rotating reflector 14, the optical unit 8 can form a high-beam light distribution pattern with a shading portion in the area where oncoming vehicles or preceding vehicles are located in front of the vehicle.

[0020] The projection lens 16 projects the light L reflected by the rotating reflector 14 in front of the lamp. The projection lens 16 is, for example, a plano-convex aspherical lens. The shape of the projection lens 16 can be selected appropriately depending on the required light distribution characteristics, such as the light distribution pattern and illuminance distribution.

[0021] The optical unit 8 is supported on the lamp body 2 via a lamp bracket 22. The lamp bracket 22 is, for example, a plate-like member arranged with its main surface facing the front-to-rear direction of the lamp fixture, and the optical unit 8 is fixed to the main surface facing the front of the lamp fixture. The light source 10 is fixed to the lamp bracket 22 via a heat sink 18. The rotating reflector 14 is fixed to the lamp bracket 22 via a base 15. The projection lens 16 is fixed to the lamp bracket 22 via a lens holder (not shown).

[0022] A joint receiving portion 24 that protrudes toward the rear of the lamp fixture is provided at the upper end of the main surface of the lamp bracket 22 that faces the rear of the lamp fixture. A shaft 26 that extends from the lamp body 2 toward the front of the lamp fixture is connected to the joint receiving portion 24. A ball joint spherical portion 26a is provided at the tip of the shaft 26. A spherical space 24a is provided in the joint receiving portion 24. The joint receiving portion 24 and the shaft 26 are connected by fitting the ball joint spherical portion 26a into the spherical space 24a.

[0023] A leveling actuator 28 is connected to the lower end of the main surface of the lamp bracket 22 facing the rear of the lamp. The leveling actuator 28 is composed of, for example, a motor that extends and retracts a rod 28a in the directions of arrows M and N, and the tip of the rod 28a is fixed to the lamp bracket 22. The optical unit 8 assumes a rearward tilt position when the rod 28a extends in the direction of arrow M. The optical unit 8 assumes a forward tilt position when the rod 28a contracts in the direction of arrow N. Therefore, the vehicular lamp 1 can change the irradiation direction in the vertical direction of the vehicle by driving the leveling actuator 28. In other words, driving the leveling actuator 28 can achieve leveling adjustment by directing the pitch angle of the optical axis Ax of the vehicular lamp 1 downward or upward.

[0024] The structure of the optical unit 8 itself and the support structure of the optical unit 8 are not limited to those described above. For example, the optical unit 8 may be configured so that light from a plurality of light sources arranged in a horizontal row or matrix is ​​irradiated in front of the lamp without passing through the rotating reflector 14. The optical unit 8 may also include a matrix-type pattern forming device such as a DMD (Digital Mirror Device) or a liquid crystal device.

[0025] The lamp chamber 6 also houses a leveling ECU 30 (equivalent to an ECU). The vehicle lamp 1 and the leveling ECU 30 constitute a vehicle lamp system 100. The leveling ECU 30 may be disposed outside the lamp chamber 6. In this case, the leveling ECU 30 may be incorporated, for example, in whole or in part into a vehicle control ECU 302 (see FIG. 2). The vehicle lamp system 100 may also include components other than the vehicle lamp 1 and the leveling ECU 30.

[0026] The leveling ECU 30 will be described in detail below. Fig. 2 is a functional block diagram illustrating the operational cooperation between the vehicle lamp 1, the leveling ECU 30, and the vehicle control ECU 302. The leveling ECU 30 and the vehicle control ECU 302 are realized as hardware components using elements and circuits such as a computer's CPU and memory, and as software components using computer programs, etc., but Fig. 2 depicts them as functional blocks realized by the cooperation of these components. Those skilled in the art will understand that these functional blocks can be realized in various ways by combining hardware and software.

[0027] The leveling ECU 30 includes an inclination sensor 32, a receiving unit 34, a vehicle lamp control device 36 (hereinafter referred to as the control device 36 as appropriate), a transmitting unit 38, a non-volatile memory 40, and an ignition detection unit 44. The inclination sensor 32 of this embodiment is mounted on a circuit board of the leveling ECU 30 and is installed in the vehicle lamp 1. However, this configuration is not particularly limited, and the inclination sensor 32 may be mounted on a circuit board separate from the leveling ECU 30. The inclination sensor 32 may also be disposed outside the lamp chamber 6.

[0028] The receiving unit 34 receives a signal indicating the output value of the tilt sensor 32. In addition, a vehicle control ECU 302 and a light switch 304 mounted on the vehicle 300 are connected to the leveling ECU 30. The signals output from the vehicle control ECU 302 and the light switch 304 are received by the receiving unit 34. A vehicle speed sensor 308, an ignition switch 314, and the like mounted on the vehicle 300 are connected to the vehicle control ECU 302. The signals output from these devices are received by the receiving unit 34 via the vehicle control ECU 302.

[0029] The light switch 304 transmits signals to control the lighting state of the vehicle lamp 1 and signals to instruct the execution of auto-leveling control to the vehicle control ECU 302 and the leveling ECU 30, depending on the operation by the driver. The light switch 304 also transmits signals to a power source 312 mounted on the vehicle 300.

[0030] The signal received by the receiving unit 34 is transmitted to the control device 36. The control device 36 can be configured with a digital processor, for example, a combination of a microcomputer including a CPU and a software program. The control device 36 may also be configured with an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific IC). The control device 36 can operate by the integrated circuit constituting the control device 36 executing a program stored in the RAM 36c, which is a volatile memory, or the non-volatile memory 40.

[0031] The control device 36 controls the illumination direction of the vehicle lamp 1 in the vertical direction of the vehicle according to the output value of the tilt sensor 32. The illumination direction of the vehicle lamp 1 in the vertical direction of the vehicle is, for example, the pitch angle of the optical axis Ax of the vehicle lamp 1. Hereinafter, this angle will be referred to as the optical axis angle θo as appropriate. In other words, the control device 36 calculates the optical axis angle θo appropriate for the attitude of the vehicle 300 based on the output value of the tilt sensor 32. Then, the control device 36 controls the leveling actuator 28 so that the current optical axis angle θo approaches the calculated optical axis angle θo. The above-mentioned "approaching" also includes the case where the current optical axis angle θo coincides with the calculated optical axis angle θo.

[0032] The control device 36, as an example, has an angle calculation unit 36a, an adjustment instruction unit 36b, and a RAM 36c. The angle calculation unit 36a generates pitch angle information of the vehicle 300 using the output value of the inclination sensor 32 and, as necessary, information stored in the RAM 36c or the non-volatile memory 40. For example, the angle calculation unit 36a stores the output value of the inclination sensor 32 in the RAM 36c, and when the number of acquired output values ​​reaches a predetermined number, it averages the acquired multiple output values ​​and derives the pitch angle of the vehicle 300 based on the output value obtained thereby.

[0033] The adjustment instruction unit 36b determines the optical axis angle θo that the vehicle lamp 1 should have based on the pitch angle information generated by the angle calculation unit 36a, and generates an adjustment signal that instructs adjustment of the optical axis angle θo. The adjustment instruction unit 36b outputs the generated adjustment signal to the leveling actuator 28 via the transmission unit 38. The leveling actuator 28 is driven based on the received adjustment signal, thereby adjusting the optical axis Ax of the vehicle lamp 1 in the pitch direction.

[0034] The ignition detection unit 44 can detect the on / off state of the ignition switch 314 by receiving a signal indicating a transition to an on or off state from the ignition switch 314 via the vehicle control ECU 302 and the receiving unit 34. Alternatively, the ignition detection unit 44 can detect a transition to an on or off state of the ignition switch 314 by monitoring the voltage supplied from the power source 312. The ignition detection unit 44 transmits a signal indicating a transition to an on or off state of the ignition switch 314 to the control device 36. The operation of each unit of the leveling ECU 30 will be described in detail later.

[0035] The vehicle 300 is equipped with a power supply 312 that supplies power to the leveling ECU 30, the vehicle control ECU 302, and the power supply circuit 42 of the vehicle lamp 1. When an instruction to turn on the vehicle lamp 1 is given by operating the light switch 304, power is supplied from the power supply 312 to the light source 10 via the power supply circuit 42. The power supply circuit 42 also supplies power to the rotating reflector 14 as necessary. The power supply from the power supply 312 to the leveling ECU 30 is performed when the ignition switch 314 is on, and is stopped when the ignition switch 314 is off.

[0036] (Auto-Leveling Control) Next, a detailed description will be given of the auto-leveling control executed by the vehicle lighting system 100 having the above-described configuration, the leveling ECU 30, and the control device 36. Fig. 3 is a schematic diagram for explaining the acceleration vector generated in the vehicle and the tilt angle of the vehicle 300 that can be detected by the tilt sensor 32.

[0037] For example, when luggage is placed in the luggage compartment at the rear of the vehicle or when passengers are present in the rear seats, the vehicle posture will tilt backward. Furthermore, when luggage is removed from the luggage compartment or passengers in the rear seats get off the vehicle, the vehicle posture will tilt forward from the backward tilted posture. When the vehicle 300 tilts backward or forward, the illumination direction of the vehicle lamp 1 also fluctuates up and down, lengthening or shortening the illumination distance of the light. Therefore, the control device 36 derives the pitch direction tilt angle of the vehicle 300 or the amount of change therein from the output value of the tilt sensor 32, and sets the optical axis angle θo to an angle corresponding to the vehicle posture. By implementing auto-leveling control that adjusts the leveling of the vehicle lamp 1 in real time based on the vehicle posture, the reach distance of the light irradiated forward can be optimally adjusted even when the vehicle posture changes.

[0038] As an example, the tilt sensor 32 is a three-axis acceleration sensor having mutually orthogonal X-axis, Y-axis, and Z-axis. The tilt sensor 32 is attached to the vehicle lamp 1 in any orientation and detects an acceleration vector occurring in the vehicle 300. The vehicle 300 is subjected to gravitational acceleration and motion acceleration caused by the movement of the vehicle 300 while it is moving. Therefore, as shown in FIG. 3 , the tilt sensor 32 can detect a resultant acceleration vector β, which is a combination of the gravitational acceleration vector G and the motion acceleration vector α. Furthermore, when the vehicle 300 is stopped, the tilt sensor 32 can detect the gravitational acceleration vector G. The tilt sensor 32 outputs the numerical values ​​of each axial component of the detected acceleration vector.

[0039] The inclination sensor 32 is attached in any orientation to the vehicle lamp 1. For this reason, the X-axis, Y-axis, and Z-axis (sensor-side axes) of the inclination sensor 32 when the inclination sensor 32 is mounted on the vehicle lamp 1 do not necessarily coincide with the front-rear axis, left-right axis, and up-down axis (vehicle-side axes) of the vehicle 300 that determine the orientation of the vehicle 300. For this reason, the control device 36 needs to convert the three-axis components output from the inclination sensor 32, i.e., the components of the sensor coordinate system, into three-axis components of the vehicle 300, i.e., the components of the vehicle coordinate system.

[0040] The leveling ECU 30 stores in advance reference axis information that indicates the positional relationship between the axis of the inclination sensor 32 attached to the vehicle lamp 1, the axis of the vehicle 300, and the road surface angle. For example, the reference axis information is stored in a non-volatile memory 40. When the angle calculation unit 36a acquires the numerical values ​​of the X-axis, Y-axis, and Z-axis components output from the inclination sensor 32, it converts them into components of the longitudinal axis, lateral axis, and vertical axis of the vehicle 300 using the reference axis information. Therefore, it is possible to derive acceleration in the longitudinal direction, lateral direction, and vertical direction of the vehicle from the output value of the inclination sensor 32.

[0041] Furthermore, the inclination of the vehicle 300 with respect to the gravitational acceleration vector G can be derived from the output value of the inclination sensor 32 while the vehicle is stopped. That is, from the output value of the inclination sensor 32, it is possible to derive a total angle θ, which is the inclination angle of the vehicle 300 with respect to the horizontal plane, including a road surface angle θr, which is the inclination angle of the road surface with respect to the horizontal plane, and a vehicle attitude angle θv, which is the inclination angle of the vehicle 300 with respect to the road surface. Note that the road surface angle θr, the vehicle attitude angle θv, and the total angle θ are angles in the pitch direction of the vehicle 300.

[0042] The auto-leveling control aims to maintain an optimum reach of the emitted light by absorbing changes in the light irradiation distance of the vehicle lamp 1 that occur with changes in the inclination angle of the vehicle 300 in the pitch direction. Therefore, the inclination angle of the vehicle 300 required for the auto-leveling control is the vehicle attitude angle θv. That is, in the auto-leveling control, it is desired that the optical axis angle θo of the vehicle lamp 1 is adjusted when the vehicle attitude angle θv changes, and that the optical axis angle θo of the vehicle lamp 1 is maintained when the road surface angle θr changes. To achieve this, it is necessary to extract information about the vehicle attitude angle θv from the total angle θ.

[0043] Therefore, the control device 36 executes auto-leveling control, which will be described below. In this control, a change in the total angle θ while the vehicle is traveling is estimated as a change in the road surface angle θr, and a change in the total angle θ while the vehicle is stopped is estimated as a change in the vehicle attitude angle θv, and the vehicle attitude angle θv is derived from the total angle θ. Since the vehicle attitude angle θv rarely changes due to an increase or decrease in the load amount or number of passengers while the vehicle is traveling, the change in the total angle θ while the vehicle is traveling can be estimated as a change in the road surface angle θr. Furthermore, since the vehicle 300 rarely moves and the road surface angle θr changes while the vehicle is stopped, the change in the total angle θ while the vehicle is stopped can be estimated as a change in the vehicle attitude angle θv.

[0044] First, when the vehicle 300 is in a predetermined reference attitude on a predetermined reference road surface, a predetermined initialization process is performed. Then, in the initialization process, an initial setting value for the road surface angle θr and an initial setting value for the vehicle attitude angle θv are acquired. The acquired initial setting values ​​are stored in the RAM 36c or the non-volatile memory 40. As a specific example, the vehicle 300 is placed on a reference road surface designed to be parallel to a horizontal plane at, for example, a vehicle manufacturer's manufacturing plant or a dealer's maintenance plant. The vehicle 300 is also set to a reference attitude. For example, the reference attitude is the attitude of the vehicle 300 when one occupant is in the driver's seat or when no one is in the vehicle. Then, an initialization signal is sent to the leveling ECU 30 by operating a switch in an initialization processing device at the factory or by communication via a CAN (Controller Area Network) system, for example.

[0045] When the control device 36 receives an initialization signal via the receiving unit 34, it executes a predetermined initialization process. In the initialization process, an initial aiming adjustment is performed, and the optical axis Ax of the vehicular lamp 1 is aligned with an initial angle. The angle calculation unit 36a also stores the output value of the inclination sensor 32 in the reference state as an initial setting value of the road surface angle θr and an initial setting value of the vehicle attitude angle θv in the RAM 36c and stores them in a volatile manner. Furthermore, these initial setting values ​​are written to the non-volatile memory 40 and stored in a non-volatile manner as necessary. The initial setting values ​​of the road surface angle θr and the vehicle attitude angle θv are each, for example, 0°.

[0046] The control device 36 then starts auto-leveling control using the initial setting value of the vehicle attitude angle θv as the reference value for the vehicle attitude angle θv and the initial setting value of the road surface angle θr as the reference value for the road surface angle θr. In the auto-leveling control, the control device 36 derives the total angle θ using the output value of the inclination sensor 32, and drives the leveling actuator 28 by outputting an adjustment signal for the optical axis angle θo in response to changes in the total angle θ while the vehicle is stopped. The control device 36 also avoids driving the leveling actuator 28 in response to changes in the total angle θ while the vehicle is moving.

[0047] Furthermore, with respect to a change in the total angle θ while the vehicle is stopped, the control device 36 holds the vehicle attitude angle θv equal to the sum of the amount of change in the total angle θ while the vehicle is stopped and the reference value of the vehicle attitude angle θv as a new reference value of the vehicle attitude angle θv. With respect to a change in the total angle θ while the vehicle is moving, the control device 36 holds the road surface angle θr equal to the sum of the amount of change in the total angle θ while the vehicle is moving and the reference value of the road surface angle θr as a new reference value of the road surface angle θr. In other words, the control device 36 repeatedly updates the reference values ​​of the road surface angle θr and the vehicle attitude angle θv every time the vehicle 300 moves or stops.

[0048] For example, in a situation where the vehicle 300 is actually used, the control device 36 avoids generating or outputting an adjustment signal or outputs a maintenance signal instructing the maintenance of the optical axis angle θo in response to changes in the total angle θ while the vehicle is moving. This prevents the leveling actuator 28 from being driven. When the vehicle stops, the control device 36 calculates road surface angle information based on the output value of the inclination sensor 32 when the vehicle is stopped. As a specific example, the angle calculation unit 36a calculates the current total angle θ, i.e., the total angle θ when the vehicle is stopped, from the output value of the inclination sensor 32 when the vehicle is stopped. Next, the angle calculation unit 36a subtracts the reference value of the vehicle attitude angle θv from the current total angle θ to obtain a road surface angle θr (corresponding to road surface angle information) (θr = θ - θv reference value). This road surface angle θr is equal to the sum of the change in the total angle θ while the vehicle is moving and the reference value of the road surface angle θr.

[0049] The angle calculation unit 36a updates the reference value of the road surface angle θr stored in the RAM 36c using the obtained road surface angle θr as a new reference value of the road surface angle θr. As a result, the change in the road surface angle θr and the estimated change in the total angle θ during vehicle travel are incorporated into the reference value of the road surface angle θr. The angle calculation unit 36a may also calculate the difference Δθ between the total angle θ before and after vehicle travel when the vehicle is stopped, and add the difference Δθ to the reference value of the road surface angle θr to obtain the road surface angle θr including the change in the total angle θ during vehicle travel (θr = θr reference value + Δθ). For example, immediately after the vehicle 300 starts, the angle calculation unit 36a may store the total angle θ immediately before starting as the reference value of the total angle θ, and calculate the difference Δθ by subtracting the reference value of the total angle θ from the total angle θ when the vehicle is stopped.

[0050] Here, the calculation timing of the road surface angle information when the vehicle is stopped will be described in detail. Fig. 4 is a diagram for explaining the vehicle running state and the calculation timing of the road surface angle θr. Fig. 5(A) and Fig. 5(B) are diagrams for explaining the first calculation process and the second calculation process.

[0051] 4, when the vehicle is stopped, which is the period from when the vehicle speed becomes 0 until the output value of the inclination sensor 32 becomes stable, the control device 36 starts calculating the road surface angle θr at the stop position in accordance with the output value of the inclination sensor 32. The angle calculation unit 36a executes a first calculation process and a second calculation process in parallel in calculating the road surface angle θr as road surface angle information.

[0052] The first calculation process is a process for calculating the road surface angle θr based on an average value calculated from multiple output values ​​of the inclination sensor 32. As shown in FIG. 5A , an example of the first calculation process includes a first process P1, a second process P2, and a third process P3. In the first process P1, a first average value A1 (average value of multiple output values) is calculated from multiple output values ​​of the inclination sensor 32 repeatedly acquired during a first predetermined time T1. In addition, the example of the first process P1 includes a process for calculating the total angle θ from the first average value A1.

[0053] In the subsequent second process P2, a second average value A2 (the average value of the multiple first average values ​​A1) is calculated from the multiple first average values ​​A1 repeatedly acquired during a second predetermined time T2. In the first process P1 of the present embodiment, the first average value A1 is converted into a total angle θ. Therefore, in the second process P2, the second average value A2 (the average value of the multiple total angles θ) is calculated from the multiple total angles θ. Calculation of the second average value A2 from the multiple total angles θ corresponds to calculation of the second average value A2 from the multiple first average values ​​A1.

[0054] In the subsequent third process P3, as shown in FIG. 5B , it is determined whether the difference ΔA between the second average value A2 and the first average value A1 obtained after calculating the second average value A2 is within a predetermined range R1 for a third predetermined time T3. This determination corresponds to determining whether the output value of the inclination sensor 32 is stable. If the difference ΔA is within the predetermined range R1 for the third predetermined time T3, it is determined that the output value of the inclination sensor 32 is stable, and the road surface angle θr is calculated based on the output value of the inclination sensor 32 obtained after calculating the second average value A2. As an example, the output value for this calculation may be the first average value A1 compared with the second average value A2 in determining the stability of the output value of the inclination sensor 32, or the first average value A1 obtained after the stability determination. The reference value of the vehicle attitude angle θv is then subtracted from the total angle θ derived from the first average value A1 to calculate the road surface angle θr. Note that the output value of the inclination sensor 32 itself may also be used.

[0055] The second calculation process, like the first calculation process, calculates the road surface angle θr based on an average value calculated from multiple output values ​​of the inclination sensor 32. Furthermore, the second calculation process is a process in which the time required to calculate the road surface angle θr is shortened compared to the first calculation process. The shortening includes at least one of shortening the first predetermined time T1, shortening the second predetermined time T2, expanding the predetermined range R1, and shortening the third predetermined time T3. Preferably, the shortening includes at least one of shortening the first predetermined time T1 and shortening the second predetermined time T2.

[0056] When the second calculation process is a process in which the first predetermined time T1 is shortened, the first average value A1 can be calculated at an earlier timing than the first calculation process. Therefore, the stability determination of the output value of the inclination sensor 32 can be performed at an earlier timing than the first calculation process. Furthermore, when the second calculation process is a process in which the second predetermined time T2 is shortened, the second average value A2 can be calculated at an earlier timing than the first calculation process. Therefore, the stability determination of the output value of the inclination sensor 32 can be performed at an earlier timing than the first calculation process. Furthermore, when the second calculation process is a process in which the predetermined range R1 is expanded or the third predetermined time T3 is shortened, the output value of the inclination sensor 32 is more likely to be determined to be stable at an earlier timing than the first calculation process. Therefore, by adjusting these parameters, the road surface angle θr can be calculated in the second calculation process earlier than the first calculation process.

[0057] For example, the angle calculation unit 36a obtains the output value of the tilt sensor 32 every few milliseconds. In the first process P1, the first predetermined time T1 is set to 1 second, and the first average value A1 is calculated every 50 milliseconds. Therefore, some of the output values ​​used to calculate the first average value A1 include those used in the previous calculation of the first average value A1. The calculated first average value A1 is converted into the total angle θ.

[0058] In the second process P2, the second predetermined time T2 is set to 1 second, and the second average value A2 is calculated every 50 ms. Therefore, a portion of the first average value A1 or the total angle θ used to calculate the second average value A2 includes that used in the previous calculation of the second average value A2. In the third process P3, the predetermined range R1 is set to a range of ±20% of the initial setting value of the road surface angle θr, that is, a range of (initial setting value - initial setting value × 0.2) or more and (initial setting value + initial setting value × 0.2) or less, the third predetermined time T3 is set to 0.5 seconds, and it is determined whether the output value of the inclination sensor 32 has stabilized.

[0059] On the other hand, in the second calculation process, the first predetermined time T1 is set within a range of 0.25 to 0.5 seconds, and the first process P1 is executed. Alternatively, the second predetermined time T2 is set within a range of 0.25 to 0.5 seconds, and the second process P2 is executed. Alternatively, the third process P3 is executed using a predetermined range R1 that adds a margin of more than ±20% to the initial setting value of the road surface angle θr. Alternatively, the third predetermined time T3 is set to less than 0.5 seconds, and the third process P3 is executed. Alternatively, each process is executed by combining two or more of these condition changes.

[0060] The first to third predetermined times T1 to T3, the predetermined range R1, and the degree of shortening of each parameter can be set as appropriate based on the designer's empirical knowledge or on experiments, simulations, etc. Alternatively, some conditions may be relaxed and others may be tightened, for example, by shortening one or both of the first predetermined time T1 and the second predetermined time T2 while narrowing the predetermined range R1 or lengthening the third predetermined time T3. This allows for a balance between shortening the time required to calculate the road surface angle θr in the second calculation process and preventing a decrease in calculation accuracy.

[0061] In this way, the second calculation process has less stringent conditions for starting to determine whether the output value is stable or for determining that the output value is stable, compared to the first calculation process. Therefore, the second calculation process can calculate the road surface angle θr at an earlier timing than the first calculation process. On the other hand, the second calculation process tends to calculate the road surface angle θr with lower accuracy than the first calculation process.

[0062] 4, the angle calculation unit 36a determines that the output value of the inclination sensor 32 has temporarily stabilized through the second calculation process, and stores the road surface angle θr calculated through the second calculation process in the RAM 36c as a provisional reference value for the road surface angle θr. After that, the angle calculation unit 36a determines that the output value of the inclination sensor 32 has truly stabilized through the first calculation process, and stores the road surface angle θr calculated through the first calculation process in the RAM 36c as a true reference value for the road surface angle θr.

[0063] After the true reference value of the road surface angle θr is calculated, the control device 36 adjusts the irradiation direction according to the vehicle attitude angle θv (corresponding to vehicle attitude angle information) obtained from the output value of the inclination sensor 32 while the vehicle is stopped and the true reference value of the road surface angle θr (corresponding to road surface angle information). As a specific example, the angle calculation unit 36a repeatedly calculates the current total angle θ from the output value of the inclination sensor 32 at a predetermined timing while the vehicle is stopped. Then, the angle calculation unit 36a subtracts the true reference value of the road surface angle θr from the current total angle θ to obtain the vehicle attitude angle θv (θv = θ - θr reference value). The obtained vehicle attitude angle θv is equal to the sum of the change in the total angle θ while the vehicle is stopped and the reference value of the vehicle attitude angle θv.

[0064] The angle calculation unit 36a updates the reference value of the vehicle attitude angle θv stored therein by using the obtained vehicle attitude angle θv as a new reference value of the vehicle attitude angle θv. As a result, the change in the vehicle attitude angle θv and the estimated change in the total angle θ while the vehicle is stopped are incorporated into the reference value of the vehicle attitude angle θv.

[0065] The adjustment instructing unit 36b then generates an adjustment signal for the optical axis angle θo in accordance with the calculated vehicle attitude angle θv or the updated new reference value of the vehicle attitude angle θv. For example, the adjustment instructing unit 36b determines the optical axis angle θo using a conversion table that associates values ​​of the vehicle attitude angle θv with values ​​of the optical axis angle θo and is stored in advance in the non-volatile memory 40 or the like, and generates the adjustment signal. The generated adjustment signal is output from the transmitting unit 38 to the leveling actuator 28.

[0066] (Control When Ignition Switch 314 Transitions to OFF State) In this embodiment, the control device 36, for example, the angle calculation unit 36a, writes the reference value of the road surface angle θr stored in the RAM 36c to the non-volatile memory 40 when the ignition switch 314 transitions to the OFF state. This allows the reference value of the road surface angle θr to be stored in a non-volatile manner. Therefore, even when the ignition switch 314 transitions to the OFF state, the reference value of the road surface angle θr can be maintained, and the accuracy of the auto-leveling control that is resumed after the ignition switch 314 transitions to the ON state can be maintained.

[0067] The control device 36 can detect that the ignition switch 314 has transitioned to the OFF state by receiving a signal from the ignition detection unit 44. The power required for the operation of writing the reference value to the non-volatile memory 40 after detecting that the ignition switch 314 has transitioned to the OFF state can be covered, for example, by the power supplied from the power source 312 from the time the ignition switch 314 is turned OFF until the power supply from the power source 312 is stopped, or by the power supplied from a storage element (not shown) such as a capacitor provided in the periphery of the power source 312 or in the leveling ECU 30. Alternatively, the power required for the operation of writing the reference value can be covered by providing the leveling ECU 30 with a power supply maintenance unit that maintains the power supply from the power source 312 for a predetermined time when the ignition switch 314 is in the OFF state.

[0068] In the auto-leveling control, a change in the total angle θ while the vehicle is stopped is estimated as a change in the vehicle attitude angle θv. Based on this technical concept, a change in the total angle θ that occurs while the ignition switch 314 is off is also estimated as a change in the vehicle attitude angle θv. In a situation where the vehicle 300 is actually used, it is rare for the vehicle 300 to move and change the road surface angle θr while the ignition switch 314 is off. For this reason, it is reasonable to estimate the change in the total angle θ between when the ignition switch 314 is off and when it is on as a change in the vehicle attitude angle θv.

[0069] Therefore, when the ignition switch 314 transitions to the ON state, as the first control after startup, the current vehicle attitude angle θv is derived using the total angle θ obtained from the output value of the inclination sensor 32 and the reference value of the road surface angle θr read from the non-volatile memory 40. This makes it possible to incorporate changes in the total angle θ that occurred while the ignition switch 314 was OFF into the reference value of the vehicle attitude angle θv. Therefore, after the ignition switch 314 transitions to the ON state, it is possible to resume auto-leveling control with maintained accuracy.

[0070] When the ignition switch 314 transitions to the OFF state after the second calculation process has ended but before the first calculation process has ended, the angle calculation unit 36a stores the road surface angle information obtained in the second calculation process, i.e., the temporary reference value of the road surface angle θr, in the non-volatile memory 40. Furthermore, when the ignition switch 314 transitions to the OFF state after the first calculation process has ended, the angle calculation unit 36a stores the road surface angle information obtained in the first calculation process, i.e., the true reference value of the road surface angle θr, in the non-volatile memory 40.

[0071] It is conceivable that the ignition switch 314 will transition to the OFF state immediately after the vehicle 300 stops. If only the first calculation process is executed, a situation may occur in which the road surface angle θr at the stop position of the vehicle 300 has not yet been calculated when the ignition switch 314 transitions to the OFF state. In this case, the reference value of the road surface angle θr calculated at a previous stop position and stored in the RAM 36c will be stored in the non-volatile memory 40. In this case, the accuracy of the auto-leveling control that is resumed after the ignition switch 314 transitions to the ON state may be reduced.

[0072] On the other hand, in this embodiment, the second calculation process is executed, which can calculate the road surface angle θr in a shorter time than the first calculation process. This reduces the number of cases where the road surface angle θr has not yet been calculated when the ignition switch 314 is turned off. Although the road surface angle θr calculated by the second calculation process is less accurate than the road surface angle θr calculated by the first calculation process, it is highly likely to be closer to the road surface angle θr at the current stop position than the reference value of the road surface angle θr stored in the RAM 36c before the vehicle 300 is stopped. Therefore, if the road surface angle θr calculated by the second calculation process is stored in the non-volatile memory 40, it is possible to prevent a decrease in the accuracy of the auto-leveling control that is resumed after the ignition switch 314 is turned on.

[0073] 6 and 7 are flowcharts of an example of auto-leveling control. These flows are repeatedly executed at predetermined timings when, for example, an instruction to execute auto-leveling control is given by the light switch 304 and the ignition switch 314 is on. The flow also ends when the instruction to execute auto-leveling control is released or an instruction to stop auto-leveling control is given, or when the ignition switch 314 is turned off. The flow shown in FIG. 6 and the flow shown in FIG. 7 are executed in parallel.

[0074] 6, first, the control device 36 determines whether an IG-OFF flag indicating that the ignition switch 314 has transitioned to the OFF state is set (S101). The control device 36 can determine whether the IG-OFF flag is set based on whether the IG-OFF flag is stored in the non-volatile memory 40. If the IG-OFF flag is set, this means that this routine is the first routine after the ignition switch 314 has transitioned to the ON state.

[0075] If the IG-OFF flag is not set (N in S101), the control device 36 determines whether the vehicle 300 is stopped (S102). The control device 36 can determine whether the vehicle 300 is stopped based on the output value of the vehicle speed sensor 308. If the vehicle 300 is not stopped (N in S102), that is, if the vehicle 300 is moving, the control device 36 ends this routine.

[0076] If the vehicle 300 is stopped (Y in S102), the control device 36 determines whether the stop determination in step S102 of the previous routine indicated that the vehicle 300 was moving (N in S102) (S103). If the previous determination indicated that the vehicle 300 was moving (Y in S103), this means that the vehicle is "stopped," and the control device 36 executes a first calculation process and a second calculation process to calculate the road surface angle θr (S104). Then, the control device 36 updates the road surface angle θr obtained in the second calculation process as a provisional reference value, and then updates the road surface angle θr obtained in the first calculation process as a true reference value (S105), and ends this routine.

[0077] If the previous determination was that the vehicle was not moving (N in S103), this means that the vehicle is stopped, and the control device 36 calculates the vehicle attitude angle θv (S106). Then, the obtained vehicle attitude angle θv is used to adjust the optical axis angle θo, and the obtained vehicle attitude angle θv is updated as a new reference value (S107), after which the routine ends.

[0078] If the IG-OFF flag is set (Y in S101), the control device 36 calculates the vehicle attitude angle θv by subtracting the reference value of the road surface angle θr read from the non-volatile memory 40 from the current total angle θ (S108). The control device 36 then updates the obtained vehicle attitude angle θv as a new reference value for the vehicle attitude angle θv (S109). Thereafter, the control device 36 cancels the setting of the IG-OFF flag (S110) and ends this routine. The control device 36 can cancel the setting of the IG-OFF flag by deleting the IG-OFF flag stored in the non-volatile memory 40.

[0079] As shown in FIG. 7 , the control device 36 determines whether the ignition switch 314 is switched off (S201). If the ignition switch 314 is not switched off (N in S201), the control device 36 terminates this routine. If the ignition switch 314 is switched off (Y in S201), the control device 36 writes the reference value of the road surface angle θr stored in the RAM 36c to the non-volatile memory 40 (S202). At this time, if the second calculation process has ended but the first calculation process has not yet ended, the temporary reference value of the road surface angle θr is written to the non-volatile memory 40. If the first calculation process has ended, the true reference value of the road surface angle θr is written to the non-volatile memory 40. Thereafter, the control device 36 sets the IG-OFF flag (S203) and terminates this routine. The control device 36 can set the IG-OFF flag by writing the IG-OFF flag to the non-volatile memory 40.

[0080] This embodiment includes a computer program executed by the control device 36. This computer program causes the control device 36 to perform the following functions: calculate road surface angle information according to the output value of the inclination sensor 32 when the vehicle is stopped; adjust the illumination direction of the vehicular lamp 1 according to vehicle attitude angle information obtained from the output value of the inclination sensor 32 while the vehicle is stopped and the road surface angle information; execute a first calculation process that calculates the road surface angle information according to an average value calculated from multiple output values; and a second calculation process that shortens the time required to calculate the road surface angle information compared to the first calculation process. After the second calculation process is completed but before the first calculation process is completed, the control device 36 stores the road surface angle information obtained by the second calculation process in the nonvolatile memory 40 when the ignition switch 314 transitions to the OFF state; and store the road surface angle information obtained by the first calculation process in the nonvolatile memory 40 when the ignition switch 314 transitions to the OFF state after the first calculation process is completed. This embodiment also includes a storage medium that stores the computer program. For example, the nonvolatile memory 40 functions as this storage medium.

[0081] The present embodiment also includes a control method for the vehicular lamp 1. This control method includes calculating road surface angle information according to an output value of the inclination sensor 32 when the vehicle is stopped, adjusting the illumination direction of the vehicular lamp 1 according to vehicle attitude angle information obtained from the output value of the inclination sensor 32 while the vehicle is stopped and the road surface angle information, performing a first calculation process in which the road surface angle information is calculated according to an average value calculated from a plurality of output values, and a second calculation process that shortens the time required to calculate the road surface angle information compared to the first calculation process, storing the road surface angle information obtained by the second calculation process in the non-volatile memory 40 when the ignition switch 314 transitions to the off state after the second calculation process but before the first calculation process is completed, and storing the road surface angle information obtained by the first calculation process in the non-volatile memory 40 when the ignition switch 314 transitions to the off state after the first calculation process is completed.

[0082] As described above, when calculating road surface angle information based on the output value of the inclination sensor 32 when the vehicle is stopped, the control device 36 according to this embodiment executes both the first calculation process and the second calculation process, which takes less time to complete calculation of the road surface angle information than the first calculation process. Then, when the ignition switch 314 transitions to the OFF state after the second calculation process is completed but before the first calculation process is completed, the control device 36 stores the road surface angle information obtained by the second calculation process in the nonvolatile memory 40. Furthermore, when the ignition switch 314 transitions to the OFF state after the first calculation process is completed, the control device 36 stores the road surface angle information obtained by the first calculation process in the nonvolatile memory 40. This prevents low-accuracy auto-leveling control from being executed when the ignition switch 314 transitions to the ON state and the auto-leveling control is resumed. This improves the accuracy of the auto-leveling control.

[0083] The control device 36 also volatilely stores the reference value of the road surface angle θr and the reference value of the vehicle attitude angle θv in the RAM 36c, and stores, in response to a change in the total angle θ while the vehicle is stopped, a vehicle attitude angle θv equal to the sum of the amount of change in the total angle θ while the vehicle is stopped and the reference value of the vehicle attitude angle θv as a new reference value of the vehicle attitude angle θv, and, in response to a change in the total angle θ while the vehicle is moving, stores a road surface angle θr equal to the sum of the amount of change in the total angle θ while the vehicle is moving and the reference value of the road surface angle θr as a new reference value of the road surface angle θr. This type of control makes it possible to achieve auto-leveling control using the incline sensor 32 with a simple control structure.

[0084] Furthermore, if the control device 36 adds the difference Δθ to the reference value of the road surface angle θr to calculate the road surface angle θr including the amount of change in the total angle θ while the vehicle is moving, and subtracts the reference value of this road surface angle θr from the total angle θ while the vehicle is stopped to obtain the vehicle attitude angle θv, auto-leveling control can be performed without using the reference value of the vehicle attitude angle θv. This type of control can simplify the auto-leveling control.

[0085] Furthermore, in the second calculation process, at least one of shortening the first predetermined time T1, shortening the second predetermined time T2, expanding the predetermined range R1, and shortening the third predetermined time T3 in the first calculation process is implemented. This makes it possible to more reliably calculate the road surface angle information by the second calculation process earlier than the calculation of the road surface angle information by the first calculation process. More preferably, in the second calculation process, at least one of shortening the first predetermined time T1 and shortening the second predetermined time T2 is implemented. This makes it possible to more reliably calculate the road surface angle information by the second calculation process earlier than the calculation of the road surface angle information by the first calculation process.

[0086] Note that, except where technically inconsistent, retaining a value obtained by calculation using predetermined components also includes retaining the components used in the calculation of that value. For example, when calculating the reference value of the road surface angle θr by subtracting the reference value of the vehicle attitude angle θv from the total angle θr, retaining the reference value of the road surface angle θr also includes retaining the reference values ​​of the total angle θ and the vehicle attitude angle θv used in the calculation. Also, when calculating the reference value of the vehicle attitude angle θv by subtracting the reference value of the road surface angle θr from the total angle θ, retaining the reference value of the vehicle attitude angle θv also includes retaining the reference values ​​of the total angle θ and the road surface angle θr used in the calculation.

[0087] The above describes the embodiments of the present invention in detail. The above-described embodiments merely illustrate specific examples of implementing the present invention. The content of the embodiments does not limit the technical scope of the present invention, and many design modifications, such as changes, additions, and deletions of components, are possible within the scope of the inventive concept defined in the claims. A new embodiment incorporating design modifications will combine the effects of the combined embodiments and modifications. In the above-described embodiments, design modifications that are possible are emphasized by using notations such as "in this embodiment" or "in this embodiment," but design modifications are also permitted even in areas without such notation. Any combination of the above components is also valid as an aspect of the present invention. Hatching in cross sections in the drawings does not limit the materials of the hatched objects.

[0088] The invention according to the above-described embodiment may be specified by the following items: [First Item] A control device (36) for a vehicle lamp (1) that controls an illumination direction of the vehicle lamp (1) in the vertical direction of the vehicle in accordance with an output value of an inclination sensor (32), the control device (36) calculates road surface angle information (θr) in accordance with the output value of the inclination sensor (32) when the vehicle is stopped, adjusts the illumination direction in accordance with vehicle attitude angle information (θv) obtained from the output value of the inclination sensor (32) when the vehicle is stopped and the road surface angle information (θr), and performs a first calculation process in which the road surface angle information (θr) is calculated in accordance with an average value (A1, A2) calculated from a plurality of output values, and a second calculation process that shortens the time required to calculate the road surface angle information (θr) compared to the first calculation process, A control device (36) for a vehicle lamp (1) stores road surface angle information (θr) obtained in the second calculation process in a non-volatile memory (40) when an ignition switch (314) transitions to an off state after the second calculation process has ended but before the first calculation process has ended, and stores road surface angle information (θr) obtained in the first calculation process in a non-volatile memory (40) when the ignition switch (314) transitions to an off state after the first calculation process has ended. [Second Item] The first calculation process includes: a first process of calculating a first average value (A1) from a plurality of output values ​​repeatedly acquired during a first predetermined time (T1); a second process of calculating a second average value (A2) from a plurality of first average values ​​(A1) repeatedly acquired during a second predetermined time (T2); and a third process of calculating road surface angle information (θr) according to the output value acquired after calculating the second average value (A2) when a difference (ΔA) between the second average value (A2) and the first average value (A1) acquired after calculating the second average value (A2) is within a predetermined range (R1) for a third predetermined time (T3), and the shortening includes at least one of shortening the first predetermined time (T1), shortening the second predetermined time (T2), extending the predetermined range (R1), and shortening the third predetermined time (T3). [Item 3] The control device (36) for the vehicle lamp (1) according to item 2, wherein the shortening includes at least one of shortening the first predetermined time (T1) and shortening the second predetermined time (T2).[Item 4] An ECU (30) comprising: an inclination sensor (32); a non-volatile memory (40); and a control device (36) for a vehicle lamp (1) according to any one of items 1 to 3. [Item 5] A vehicle lamp system (100) comprising: a vehicle lamp (1) capable of changing the illumination direction in the vertical direction of the vehicle; and the ECU (30) according to item 4. [Item 6] A computer program executed by a control device (36) of a vehicle lamp (1) for controlling an illumination direction of the vehicle lamp (1) in the vertical direction of the vehicle in accordance with an output value of an inclination sensor (32), the computer program comprising: calculating road surface angle information (θr) in accordance with the output value of the inclination sensor (32) when the vehicle is stopped; adjusting the illumination direction in accordance with vehicle attitude angle information (θv) obtained from the output value of the inclination sensor (32) when the vehicle is stopped and the road surface angle information (θr); and performing, in the calculation of the road surface angle information (θr), a first calculation process for calculating the road surface angle information (θr) in accordance with average values ​​(A1, A2) calculated from a plurality of output values; and a second calculation process for shortening the time required to calculate the road surface angle information (θr) compared to the first calculation process, A computer program that causes a control device (36) of a vehicle lamp (1) to execute a function of storing road surface angle information (θr) obtained in the second calculation process in a non-volatile memory (40) when an ignition switch (314) transitions to an off state after the second calculation process has ended but before the first calculation process has ended, and storing road surface angle information (θr) obtained in the first calculation process in the non-volatile memory (40) when the ignition switch (314) transitions to an off state after the first calculation process has ended.[Item 7] A control method (36) for a vehicle lamp (1) for controlling an illumination direction of the vehicle lamp (1) in the vertical direction of the vehicle in accordance with an output value of an inclination sensor (32), comprising: calculating road surface angle information (θr) in accordance with the output value of the inclination sensor (32) when the vehicle is stopped; adjusting the illumination direction in accordance with vehicle attitude angle information (θv) obtained from the output value of the inclination sensor (32) when the vehicle is stopped and the road surface angle information (θr); and performing, in the calculation of the road surface angle information (θr), a first calculation process for calculating the road surface angle information (θr) in accordance with an average value (A1, A2) calculated from a plurality of output values; and a second calculation process in which the time required to calculate the road surface angle information (θr) is shortened compared to the first calculation process. A method for controlling a vehicle lamp (1), comprising: storing road surface angle information (θr) obtained by the second calculation process in a non-volatile memory (40) when an ignition switch (314) transitions to an off state after the second calculation process has ended but before the first calculation process has ended; and storing road surface angle information (θr) obtained by the first calculation process in a non-volatile memory (40) when the ignition switch (314) transitions to an off state after the first calculation process has ended.

[0089] The present invention can be used in a vehicle lighting control device, an ECU, a vehicle lighting system, a computer program, and a vehicle lighting control method.

[0090] 1 Vehicle lighting fixture, 30 Leveling ECU, 32 Inclination sensor, 36 Control device, 40 Non-volatile memory, 100 Vehicle lighting system, 314 Ignition switch, A1 First average value, A2 Second average value, P1 First processing, P2 Second processing, P3 Third processing, R1 Predetermined range, T1 First predetermined time, T2 Second predetermined time, T3 Third predetermined time.

Claims

1. A control device for a vehicle lamp that controls the irradiation direction of the vehicle lamp in the vertical direction of the vehicle according to the output value of an inclination sensor, which calculates road surface angle information according to the output value of the inclination sensor when the vehicle stops, and adjusts the irradiation direction according to the vehicle attitude angle information obtained from the output value of the inclination sensor during vehicle stop and the road surface angle information. In the calculation of the road surface angle information, a first calculation process is executed to calculate the road surface angle information according to an average value calculated from a plurality of the output values, and a second calculation process is executed in which the time required to calculate the road surface angle information is shortened compared to the first calculation process. When the ignition switch shifts to the off state after the end of the second calculation process and before the end of the first calculation process, the road surface angle information obtained by the second calculation process is stored in a non-volatile memory, and when the ignition switch shifts to the off state after the end of the first calculation process, the road surface angle information obtained by the first calculation process is stored in the non-volatile memory. A control device for a vehicle lamp.

2. The first calculation process includes a first process of calculating a first average value from a plurality of the output values repeatedly acquired during a first predetermined time, a second process of calculating a second average value from a plurality of the first average values repeatedly acquired during a second predetermined time, and a third process of calculating the road surface angle information according to the output value acquired after the calculation of the second average value when the difference between the second average value and the first average value acquired after the calculation of the second average value is within a predetermined range during a third predetermined time. The shortening includes at least one of shortening the first predetermined time, shortening the second predetermined time, expanding the predetermined range, and shortening the third predetermined time. The control device for a vehicle lamp according to claim 1.

3. The shortening includes at least one of shortening the first predetermined time and shortening the second predetermined time. The control device for a vehicle lamp according to claim 2.

4. An ECU comprising an inclination sensor, a non-volatile memory, and the control device for a vehicle lamp according to any one of claims 1 to 3.

5. A vehicle lamp system comprising a vehicle lamp capable of changing the irradiation direction in the vertical direction of the vehicle and the ECU according to claim 4.

6. A computer program executed by a control device for a vehicle lamp that controls the irradiation direction of the vehicle lamp in the vehicle's vertical direction according to the output value of an inclination sensor, the program calculating road surface angle information according to the output value of the inclination sensor when the vehicle is stopped, adjusting the irradiation direction according to vehicle attitude angle information obtained from the output value of the inclination sensor during vehicle stop and the road surface angle information, in the calculation of the road surface angle information, executing a first calculation process for calculating the road surface angle information according to an average value calculated from a plurality of the output values, and a second calculation process in which shortening of the time required for calculating the road surface angle information is achieved for the first calculation process, and storing the road surface angle information obtained by the second calculation process in a non-volatile memory when the ignition switch shifts to the off state after the end of the second calculation process and before the end of the first calculation process, and causing the control device for the vehicle lamp to execute a function of storing the road surface angle information obtained by the first calculation process in the non-volatile memory when the ignition switch shifts to the off state after the end of the first calculation process.

7. A control method for a vehicle lamp that controls the irradiation direction of the vehicle lamp in the vehicle's vertical direction according to the output value of an inclination sensor, the method calculating road surface angle information according to the output value of the inclination sensor when the vehicle is stopped, adjusting the irradiation direction according to vehicle attitude angle information obtained from the output value of the inclination sensor during vehicle stop and the road surface angle information, in the calculation of the road surface angle information, executing a first calculation process for calculating the road surface angle information according to an average value calculated from a plurality of the output values, and a second calculation process in which shortening of the time required for calculating the road surface angle information is achieved for the first calculation process, and storing the road surface angle information obtained by the second calculation process in a non-volatile memory when the ignition switch shifts to the off state after the end of the second calculation process and before the end of the first calculation process, and storing the road surface angle information obtained by the first calculation process in the non-volatile memory when the ignition switch shifts to the off state after the end of the first calculation process.

Images