JP2002219995A - Light distribution control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure a sufficient field of view even on a hilly way. SOLUTION: The steering angle of vehicle wheels is sensed by a steering angle sensor 11, while the engine speed is sensed by an ECU 12. On the basis of the obtained steering angle and engine speed, a target light distribution angle calculation part 13 senses the vehicle advancing direction and judges whether the vehicle is running on hilly way. The target light distribution angle is subjected to a calculative processing in accordance with the result from judgement, and on the basis of the target light distribution angle obtained through calculation, the optical axis of a lamp 20 to project light in the vehicle advancing direction is controlled by a motor driver 22 and a motor 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light distribution control device for controlling a light distribution direction of light emitted from illumination means for irradiating a traveling direction of a vehicle.

[0002]

2. Description of the Related Art For example, a vehicle such as an automobile is equipped with a headlamp as illumination means for irradiating a traveling direction. However, in a headlamp having a fixed irradiation direction, there are places where a sufficient amount of light cannot be applied to a changing traveling environment, and thus a sufficient visibility in nighttime traveling may not be ensured.

Therefore, conventionally, many light distribution control devices have been proposed in which a part or all of the traveling direction of light emitted from a headlamp can be changed by driving the headlamp with an actuator or the like.

In a conventional light distribution control device, a traveling direction of a vehicle is detected, and the light distribution of light emitted from a headlamp is driven in a horizontal direction or a vertical direction according to the detected result. Thus, a large amount of light is emitted in the direction of the viewpoint of the vehicle driver in accordance with the traveling direction of the vehicle, so that light from the headlamp having a limited light amount can be effectively used.

[0005]

However, the conventional light distribution control device is supposed to be used on an urban road with a relatively flat surface and a good visibility. There is a problem that it is not suitable for use on bad mountain roads.

More specifically, a mountain road generally has a smaller radius of curvature of a road than an urban road, and has a wide required visibility range in a horizontal direction with respect to a traveling direction. Therefore, if light distribution control similar to light distribution control on an urban road is applied to a mountain road by a conventional light distribution control device, there is a possibility that a sufficient left and right direction field of view cannot be secured.

The present invention has been proposed in view of the above-described circumstances, and has as its object to provide a light distribution control device capable of securing a sufficient field of view even on a mountain road.

[0008]

In order to solve the above-mentioned problems, a first aspect of the present invention is a traveling direction detecting means for detecting a traveling direction of a vehicle, and determining whether or not the vehicle is traveling on a mountain road. A target light distribution angle of the light emitted from the illuminating means for irradiating the traveling direction of the vehicle according to the traveling direction of the vehicle detected by the traveling direction detecting means, and the traveling direction of the vehicle detected by the traveling direction detecting means. And a light axis changing means for varying the optical axis of the lighting means in the left-right horizontal direction of the vehicle in accordance with the target light distribution angle calculated by the target light distribution angle calculating means. And

In the light distribution control device according to a second aspect, the target light distribution angle calculating means determines that the vehicle is traveling on a mountain road when the vehicle is traveling on a mountain road by the mountain road traveling determination means. It is desirable to make the target light distribution angle larger than in the case where it is determined that the light distribution angle is not present.

[0010] In the light distribution control device according to claim 3, the target light distribution angle calculating means is provided only when the amount of change in the traveling direction of the vehicle detected by the traveling direction detecting means exceeds a predetermined value. It is desirable to increase the target light distribution angle.

In the light distribution control device according to a fourth aspect, the traveling direction detecting means detects a traveling direction of the vehicle by detecting at least one of a speed difference between respective wheels of the vehicle and a steering angle. May be.

In the light distribution control device according to a fifth aspect of the present invention, the mountain road traveling determining means keeps the vehicle running on a mountain road when the engine speed of the vehicle has reached a predetermined value for a predetermined period of time. May be determined.

According to a sixth aspect of the present invention, in the light distribution control device, the mountain road traveling determining means changes the operation mode of the transmission in the vehicle having the transmission in which the manual operation mode and the automatic operation mode are variable from the automatic operation to the manual operation mode. By switching to the operation, it may be determined that the vehicle is traveling on a mountain road.

In the light distribution control device according to a seventh aspect, the mountain road traveling determining means determines that the vehicle is traveling on a mountain road based on mountain road traveling information output from a navigation system mounted on the vehicle. May be.

[0015]

According to the light distribution control device of the first aspect,
The optical axis of the light emitted from the illuminating means for irradiating the traveling direction of the vehicle can be varied in the horizontal direction in accordance with the traveling direction of the vehicle and whether the vehicle is traveling on a mountain road or not. Thus, according to the light distribution control device of the first aspect, an angle that is optimal for each traveling condition is set when the vehicle is traveling on an urban road and when the vehicle is traveling on a mountain road. Can be. Therefore, according to the light distribution control device of the first aspect, it is possible to secure a sufficient field of view even on a mountain road.

According to the light distribution control device of the second aspect, when the vehicle travels on a mountain road where the radius of curvature of the road is smaller than that of an urban road, the light distribution angle of the illumination means can be largely changed in the horizontal direction. In addition, it is possible to sufficiently secure the visibility in the left-right direction even on a mountain road.

According to the light distribution control device of the third aspect, the amount of change of the optical axis of the illumination means by the optical axis changing means can be suppressed when traveling on a mountain road having a large radius of curvature. In addition, it is possible to prevent the optical axis from being changed more than necessary.

According to the light distribution control device of the fourth aspect, the traveling direction of the vehicle can be appropriately detected, the viewpoint direction of the vehicle driver can be reliably predicted, and the light emitted from the illumination means in the viewpoint direction. Can be distributed. Further, the traveling direction detecting means may detect both the speed difference of each wheel and the steering angle of each wheel, and may detect the traveling direction of the vehicle based on each detection result. Thereby, the traveling direction of the vehicle can be detected more appropriately. Further, according to this light distribution control device, a relatively inexpensive detection sensor or the like can be used by detecting the speed difference and the steering angle of each wheel. And GPS (Global Positioning)
The system configuration can be simplified as compared with the case where the traveling direction is detected by a method of performing a mapping process with a map with reference to the position information output from the system. Therefore, according to this light distribution control device, it is possible to set the light distribution angle to an optimum angle for each traveling condition when the vehicle is traveling on an urban road and when traveling on a mountain road. A simple light distribution control device can be realized at extremely low cost.

According to the light distribution control device of the fifth aspect, the rotation of the engine is performed by using the fact that the engine runs at a higher speed when traveling on a mountain road than when traveling on an urban road. By detecting the number, it can be determined whether or not the vehicle is traveling on a mountain road.

According to the light distribution control device of the sixth aspect, in a vehicle in which the operation mode of the transmission is variable between a manual operation mode and an automatic operation mode, the vehicle is switched from automatic to manual operation when traveling on a mountain road. By utilizing the fact that the transmission mode is often used, it is possible to determine whether or not the vehicle is traveling on a mountain road.

According to the light distribution control device of the present invention, it is possible to easily determine whether or not the vehicle is traveling on a mountain road by operating in cooperation with a navigation system that has become widespread in recent years. Can be.

[0022]

Embodiments of the present invention will be described below in detail with reference to the drawings. Hereinafter, a light distribution control device 1 shown in FIG. 1 will be described as a specific configuration example of the light distribution control device according to the present invention.

[Configuration of Light Distribution Control Device] Light Distribution Control Device 1
As shown in FIG. 1, a pair of headlamp units 10A and 10B for irradiating the traveling direction of the vehicle (hereinafter, simply referred to as "headlamp unit 10") and a steering angle of a wheel are detected. A steering angle sensor 11 and an engine control unit (ECU: Engine) for controlling the engine
Control unit 12 and a target light distribution angle calculation unit 13 for calculating a target light distribution angle in the headlamp unit 10.

The light distribution control device 1 includes a tail lamp section 14 for illuminating the rear of the vehicle, a lighting switch 15 for turning on / off the head lamp section 10 and the tail lamp section 14, and a lighting switch 15 for 1 second.
When the switch is switched to t, the power from the power supply unit 16 is supplied to the tail lamp unit 14 and the small lamp unit (not shown) provided in the head lamp unit 10, and the lighting switch 15 is switched to the second lamp. The head lamp relay 17 and the tail lamp relay 18 which supply the electric power from the power supply unit 16 to the head lamp unit 10 and the tail lamp unit 14 respectively are provided.

In this light distribution control device, the head lamp relay 17 and the tail lamp relay are controlled to open and close in accordance with a drive signal supplied from the lighting switch 15 to the head lamp relay 17 and the tail lamp relay 18.
A power supply 16 is connected to the head lamp unit 10 and the tail lamp unit 14.
To turn on / off each lamp.

The pair of headlamp units 10 are respectively
The system includes a lamp 20 that emits light for irradiating the traveling direction of the vehicle, a motor 21 that mainly drives the optical axis of the lamp 20 in a horizontal direction, and a motor driver 22 that controls the driving of the motor 21. Motor driver 22
Drives the motor 21 in accordance with the target light distribution angle calculated and output by the target light distribution angle calculation unit 13, whereby
The optical axis of the lamp 20 is variable in the horizontal direction.

That is, in the present embodiment, the illuminating means for irradiating the traveling direction of the vehicle with the lamp 20 is constituted, and the motor 21 and the motor driver 22
It has a function as an optical axis changing means for changing the optical axis of the illumination means in the horizontal direction according to the target light distribution angle. The optical axis changing means includes the motor 21 and the motor driver 2.
The configuration is not limited to the configuration using two actuators, but may be configured using various actuators.

The steering angle sensor 11 is disposed on, for example, a front wheel section for steering the vehicle or a steering wheel as a steering section for controlling the steering direction, and detects a steering angle of the vehicle. Then, the steering angle sensor 11 outputs a steering angle signal indicating the detected steering angle to the target light distribution angle calculation unit 13. That is, in the present embodiment, the steering angle sensor 11
Have a function as traveling direction detecting means for detecting the traveling direction of the vehicle.

The traveling direction detecting means is not limited to the steering angle sensor 11. For example, the traveling direction of the vehicle may be detected by detecting a speed difference between the wheels. Good. Specifically, for example, a speed sensor that detects the rotation speed of the wheel is provided for each wheel,
The traveling direction of the vehicle is detected by detecting the difference between the rotation speeds output from the speed sensors.

The ECU 12 includes, for example, a control circuit composed of various semiconductor elements and performs various controls on an engine constituting the vehicle. Specifically, the ECU 12 controls the fuel supplied to the engine, monitors the temperature of the engine, detects the number of revolutions of the engine, and the like.
Further, the ECU 12 outputs to the target light distribution angle calculation unit 13 a signal in which the number of output pulses per unit time changes according to the engine speed.

The target light distribution angle calculation unit 13 includes a CPU (Central Processing Unit) 30 for performing various calculation processes, and an RO as a read-only memory for storing a calculation program or the like in which the procedure of the calculation process by the CPU 30 is described.
M (Read Only Memory) 31, a RAM (Random Access Memory) 32 as a rewritable memory for temporarily storing the result of arithmetic processing in the CPU 30, and a timer for counting up or down a timer value at regular time intervals 33, a serial communication interface 34 to which a steering angle signal from the steering angle sensor 11 is input,
The light distribution control device 1 includes an interface circuit (I / F circuit) 35 for inputting / outputting various signals to / from each of the other units.

Further, the target light distribution angle calculation unit 13 includes a CPU 3
0, a ROM 31, a RAM 32, a timer 33, a serial communication interface 34, and an input / output control unit (I / O control unit) 36 are connected via an address bus and a data bus. Various signals can be input and output. The target light distribution angle calculation unit 13
Are configured by, for example, various semiconductor elements and the like.

In the target light distribution angle calculation unit 13, the ROM 3
1 stores an output characteristic of a target light distribution angle according to the traveling direction of the vehicle and the traveling state of the vehicle, in addition to an arithmetic program in which the procedure of the arithmetic processing by the CPU 30 is described. Then, the CPU 30 performs arithmetic processing according to the arithmetic program stored in the ROM 31, and thereby, according to the traveling state of the vehicle, that is, whether the vehicle is traveling on an urban road or a mountain road, and the traveling direction of the vehicle. RO
The target light distribution angle is calculated and output based on the output characteristic of the target light distribution angle stored in M31. The calculated and output target light distribution angle is output to the headlamp unit 10 via the I / F circuit 35.
Are output in parallel to the motor driver 22.

At this time, the target light distribution angle calculation unit 13 obtains information on the traveling direction of the vehicle according to the steering angle signal from the steering angle sensor 11 input via the serial communication interface 34. In addition, the target light distribution angle calculation unit 13
Based on a signal from the ECU 12 input via the I / F circuit 35, the CPU 30 determines that the engine speed has reached a predetermined value within a predetermined period,
It is determined that the vehicle is traveling on a mountain road instead of a city road.

That is, in the present embodiment, the function as the target light distribution angle calculating means for calculating the target light distribution angle of the light emitted from the lighting means according to the traveling direction of the vehicle and the traveling state of the vehicle is the target light distribution. The ECU 12 and the target light distribution angle calculating unit 13 realize a function as a mountain road running determination unit that determines whether or not the vehicle is running on a mountain road, while being realized by the angle calculating unit 13.

"Address Structure of RAM 32" In the target light distribution angle calculation unit 13, the RAM 32
Has a function of temporarily storing various variables and the like used in the arithmetic processing by the. Therefore, an example of the address structure in the RAM 32 will be described below with reference to FIG. In FIG. 2, address [a] indicates a flag area start address, various flags are stored after address [a], address [b] indicates a variable area start address, and various addresses are set after address [b]. A variable is stored, an address [c] indicates a ring buffer area head address, and various data are stored after the address [c].

In the RAM 32, a lamp initialization completed flag (INIT_LAMP) indicating whether or not the optical axis of the lamp 20 in the headlamp unit 10 has been initialized is stored at an address [a]. Motor driving flag (MONITOR) indicating whether the motor is operating
Is stored at the address [a + 1].

In the RAM 32, a variable (t) indicating the current timer value of the timer 33 is stored at an address [b], and a variable (t ') indicating the previous timer value of the timer 33 is stored at an address [b + 1]. Is stored.

Further, of the pair of headlamp units 10,
Lamp target positions (mark_lh) and (mark_rh), which are variables indicating the target light distribution angle for the left headlamp unit 10 and the target light distribution angle for the right headlamp unit 10, respectively.
Are stored at addresses [b + 2] and [b + 3], respectively. A lamp current position (position_lh), which is a variable indicating the current light distribution angle of the left headlamp unit 10 and the current light distribution angle of the right headlamp unit 10, respectively.
(Position_rh) are the addresses [b + 4],
It is stored in [b + 5].

The RAM 32 has a steering angle sensor 11.
The steering angle value (hand) which is a variable indicating the steering angle of the vehicle calculated by the CPU 30 based on the steering angle signal input from the
le_angle) is stored at the address [b + 6]. Also,
The rotation speed (rpm), which is a variable indicating the rotation speed of the engine calculated by the CPU 30 based on the signal input from the ECU 12, is stored at the address [b + 7].

The RAM 32 stores a ring buffer pointer (p_ringbuffe) which is a variable indicating a pointer to the ring buffer area set after the address [c].
r) is stored at the address [b + 8], and the end pointer (_p_ringb
buffer) is stored at address [b + 9].

The RAM 32 stores an excess counter (count), which is a variable indicating a period during which the engine speed exceeds a predetermined value, at an address [b + 10]. Further, a drive gain (gain), which is a variable indicating an output gain of the target light distribution angle to be output to the headlamp unit 10, is stored in the address [b + 11].

[Calculation Processing by Target Light Distribution Angle Calculation Unit 13]
The target light distribution angle calculation unit 13 configured as above is
CPU 30 according to the arithmetic program stored in M31.
Operates to calculate the target light distribution angle and output it to the headlamp unit 10. Therefore, an example of the calculation process in the target light distribution angle calculation unit 13 will be described below with reference to flowcharts shown in FIGS.

The target light distribution angle calculation unit 13 starts the processing of the main routine when the headlamp relay 17 is turned on by the lighting switch 15, for example. When the processing of the main routine is started, the target light distribution angle calculation unit 13 executes step S shown in FIG.
As shown in FIG. 1, the CPU 30 initializes various variables in the RAM 32, starts an interrupt process of the timer 33 and operates the timer 33, and performs initialization, and proceeds to step S2.

Next, in step S2, the CPU 30
The lamp initialization completed flag (INIT_L) stored in the RAM 32
AMP) is off. If the result of this determination is that the lamp initialization completed flag (INIT_LAMP) is off, the process proceeds to step S3; if it is on, the process proceeds to step S8.

In step S3, the CPU 30
Motor driving flag (MONITOR) stored in AM32
Is turned off. If the result of this determination is that the motor driving flag (MONITOR) is off, the process proceeds to step S4; if it is on, the process proceeds to step S6.

In step S4, the CPU 30 rewrites the contents of the RAM 32 so as to set the motor driving flag (MONITOR) to ON, and proceeds to step S5.

In step S5, the CPU 30
The motor driver 22 of the headlamp unit 10 is controlled via the / F circuit 35 to drive the motor 21 to an initial position stored in advance in, for example, the ROM 31. This allows
The optical axis of the lamp 20 in the headlamp section 10 is set to the initial position. After this processing, the processing in the CPU 30 returns to step S2.

On the other hand, in step S6, the CPU 30
Determines whether the motor 21 has been set to the initial position. If the result of this determination is that the motor 21 has been set to the initial position, the process proceeds to step S7; otherwise, the drive of the motor 21 is continued and the process returns to step S2.

In step S 7, the CPU 30 sets a lamp initialization completed flag (INIT_LAMP) to ON, and stores the value of this flag in the RAM 32. After this processing, the processing in the CPU 30 returns to step S2.

That is, in step S2, it is determined whether or not the motor 21 is set to the initial position and the optical axis of the lamp 20 is set to the initial position. Will be advanced to step S8.

In step S8, the CPU 30 reads the current timer value counted up or down by the timer 33 with reference to the timer value (t) in the RAM 32.

Next, in step S9, the CPU 30
Calculates the difference (T = t′−t) between the previous timer value (t ′) stored in the RAM 32 and the current timer value (t).

Next, in step S10, the CPU 3
A value of 0 determines whether or not the value T calculated in step S9 has reached a predetermined sampling time. If the result of this determination is that the predetermined sampling time has not been reached, the process returns to step S2 to continue counting up or down by the timer 33, and if so, the process proceeds to step S11.

Next, in step S11, the CPU 3
0 stores the current timer value (t) in the RAM 32 as the previous timer value (t ').

Next, in step S12, the CPU 3
0 acquires the steering angle signal output from the steering angle sensor 11 via the serial communication interface 34, and calculates the steering angle of the vehicle. Then, the calculated steering angle is stored in the RAM 32 as a variable value serving as a steering angle value (handle_angle).

Next, in step S13, the CPU 3
0 acquires the engine speed signal output by the ECU 12 via the I / F circuit 35. Then, the engine speed is set as a variable value of the engine speed (rpm) as RA.
Store it in M32.

Next, at step S14, the CPU 3
0 acquires the value of the ring buffer pointer (p_ringbuffer) stored in the RAM 32, and the number of rotations (rpm) stored in the RAM 32 in the ring buffer (b_ring [p_ringbuffer]) of the address indicated by the ring buffer pointer (p_ringbuffer). Is stored.

Next, in step S15, the CPU 3
0 calculates the value of the ring buffer pointer (p_ringbuffer), and calculates the time during which the engine speed becomes higher than a predetermined rotation speed within a predetermined time. The details of the processing in step S15 will be described later.

Next, in step S16, the CPU 3
0 indicates that the value of the drive gain (gain) stored in the RAM 32 is calculated, and the headlamp unit 10 is turned on when the engine speed becomes higher than a predetermined speed within a predetermined time. The output gain of the target light distribution angle to be output is set high, and the output gain is set low when the engine speed decreases. The processing in step S16 will be described later in detail.

Next, in step S17, the CPU 3
0 is the steering angle value (handle_angle) stored in the RAM 32
The target light distribution angle is calculated by performing an arithmetic process based on. The details of the processing in step S17 will be described later.

Next, in step S18, the CPU 3
0 determines whether or not the small lamp of the vehicle is lit. In FIG. 1, illustration of the small lamp is omitted.

In this embodiment, when the small lamp is turned on, the light distribution control in the head lamp unit 10 is performed, and when the small lamp is not turned on, the light distribution control in the head lamp unit 10 is not performed. And Therefore, if the result of determination in step S18 is that the small lamp is on, the process proceeds to step S19, where the target light distribution angle output from the target light distribution angle calculation unit 13 is calculated using the target light distribution angle calculated in step S17. Set to the light angle. If the small lamp is not turned on, the process proceeds to step S20, and the target light distribution angle calculation unit 13
The target light distribution angle output from is kept at the initial value. Then, after any of the processes in step S19 or step S20, the process returns to step S2 and the CP
A series of arithmetic processing in U30 is repeated.

[Operation of Ring Buffer Pointer] Next, the ring buffer pointer (p_ringbuffe) in step S15 in the main routine described above will be described below.
The calculation processing of the value of r) will be described in detail with reference to the flowchart shown in FIG.

First, as shown in step S21 in FIG. 4, the CPU 30 sets the ring buffer pointer (p_ri
ngbuffer) is a predetermined value (in the present embodiment,
This predetermined value is set to [100]. ) To determine whether overflow has occurred. If the result of this determination is that there is an overflow, the process proceeds to step S22,
If not, the process proceeds to step S23.
Proceed to

In step S22, the CPU 30
Set the value of the ring buffer pointer (p_ringbuffer) to [0]
And the process proceeds to step S24.

In step S23, the CPU 3
If it is 0, the value of the ring buffer pointer (p_ringbuffer) is incremented by one, and the process proceeds to step S24.

In step S24, the CPU 30
It is determined whether the ring buffer pointer (p_ringbuffer) is below a predetermined count period. If the result of this determination is that it is below, the process proceeds to step S25; otherwise, the process proceeds to step S26.

Here, in the present embodiment, it is determined that the vehicle is traveling on a mountain road when the engine speed is higher than the predetermined speed within a predetermined period. When determining that the vehicle is traveling on a mountain road as described above, in the present embodiment, an excess counter (count) is determined in accordance with a period during which the engine speed is higher than a predetermined speed as described later. Is increased or decreased. Thus, when increasing or decreasing the value of the excess counter (count), it is necessary to calculate the value of the end pointer (_p_ringbuffer). In this calculation, the value of the ring buffer pointer (p_ringbuffer) becomes lower than the predetermined count period. The arithmetic expression is different between the case where there is and the case where there is above. Therefore,
In step S24, the cases are classified.

In step S25, CPU 30
Calculates the value of the tail pointer (_p_ringbuffer). At this time, the CPU 30 calculates the value of the end pointer (_p_ringbuffer) by subtracting the value of the predetermined count period from the current value of the ring buffer pointer (p_ringbuffer) and adding the value [100]. After this, the CPU
30 advances the processing to step S27.

In step S26, the CPU 3
0 calculates the value of the end pointer (_p_ringbuffer). At this time, the CPU 30 subtracts the value of the predetermined count period from the current value of the ring buffer pointer (p_ringbuffer) to obtain the end pointer (_p_ringbuffe).
Calculate the value of r). Thereafter, the CPU 30 advances the processing to step S27.

In step S27, the CPU 30
It is determined whether or not the rotation speed (rpm) stored in the ring buffer (b_ring [p_ringbuffer]) indicated by the current ring buffer pointer (P_ringbuffer) is equal to or greater than a predetermined value. As a result of this determination, if the value is equal to or greater than the predetermined value, the process proceeds to step S28; otherwise, the process proceeds to step S29.

In step S28, the CPU 30
Increment the value of the excess counter (count) by one. After this processing, the process proceeds to step S29.

At step S29, the CPU 30
End pointer (_p_rin) a predetermined time before the current pointer
gbuffer) ring buffer (b_ring [_p_ringbuf
fer]), it is determined whether or not the number of revolutions (rpm) stored is equal to or higher than a predetermined value set in advance. As a result of this judgment,
If the value is equal to or more than the predetermined value, the process proceeds to step S30; otherwise, the process proceeds to step S30.
After ending the process in step 15, the process proceeds to step S16 in the main routine.

In step S30, the CPU 30
Decrement (subtract) the value of the excess counter (count) by one. After this processing, a series of processing in step S15 ends, and the process proceeds to step S16.

A series of processing in step S15 as described above has the same meaning as counting the time only while the engine speed (rpm) is equal to or higher than a predetermined value.

FIG. 5 is a flowchart showing the operation of calculating the drive gain (gain) in step S16 in the main routine described above.

First, as shown in step S31 in FIG. 5, the CPU 30 determines whether or not the value of the excess counter (count) exceeds a predetermined value. If the result of this determination is that there is an overrun, the process proceeds to step S32; otherwise, the process proceeds to step S33.

In step S32, the CPU 30
It is determined that the vehicle is traveling on a mountain road, and the drive gain (gai
The value of n) is set to a large value and stored in the RAM 32. After this processing, the CPU 30 ends the series of processing in step S16, and advances the processing to step S17 in the main routine.

In step S33, the CPU 3
A value of 0 determines that the vehicle is traveling on an urban road, sets the value of the drive gain (gain) to a value smaller than the value set in step S32, and stores the value in the RAM 32. After this processing, the CPU 30 ends the series of processing in step S16, and proceeds to step S16 in the main routine.
Proceed to 17.

By the series of processing in step S16 as described above, the CPU 3 in the target light distribution angle calculation unit 13
0 indicates whether the vehicle is traveling on a mountain road or a city road, and the value of the drive gain can be made variable according to the traveling state of the vehicle.

[Target Angle Calculation Processing] FIG. 6 is a flowchart showing the target angle calculation processing in step S17 in the main routine described above.

First, as shown in step S40 in FIG.
The target angle (angle) of the optical axis 0 is calculated. This target angle (a
ngle) is the drive gain (gain) stored in the RAM 32.
Is multiplied by a steering angle value (handle_angle), and then divided by a predetermined constant value (A). As a result, the target light distribution angle calculation unit 13 calculates the target angle (angle) according to the steering angle of the vehicle.

Next, in step S41, the CPU 3
0 indicates that the target angle (angle) calculated in step S40 is
It is determined whether or not the maximum driveable angle of the lamp 20 in the headlamp section 10 has been exceeded. As a result of this judgment,
If it exceeds the maximum drivable angle, the process proceeds to step S42; otherwise, the process proceeds to step S42.
Proceed to 43.

In step S42, the CPU 30
Instead of the target angle (angle) calculated in step S40, the maximum drivable angle of the lamp 20 is changed to the target angle (angle).
Set to. Thus, it is possible to prevent a target light distribution angle exceeding the maximum drivable angle of the lamp 20 from being output.

Next, in step S43, the CPU 3
0 divides the target angle (angle) by the driving accuracy of the lamp 20 to calculate the target light distribution angle. Then, the calculated target light distribution angles are used as lamp target positions (mark_lh) and (mark_lh), which are variables corresponding to the left and right headlamp units 10, respectively.
rh) and store it in the RAM 32. After this processing, the CPU 30 ends the series of processing in step S17, and proceeds to step S1 in the main routine.
Proceed to 8.

The target light distribution angle is stored in the RAM 32 by a series of processing in step S17 as described above. In step S17, when calculating the target light distribution angle, the target light distribution angle may be calculated separately for each of the left and right headlamp units 10, or the same target light distribution angle may be calculated to calculate the left and right headlight units. May be set to the same value for the target light distribution angle with respect to the headlamp unit 10. However, by separately calculating the target light distribution angles for the left and right headlamp units 10, the degree of freedom of the light distribution angle of the light emitted by the pair of headlamp units 10 can be improved. By using a certain amount of light more effectively, optimal illumination can be performed according to the traveling state and traveling direction of the vehicle.

[Timer Interruption Processing] In the processing in the target light distribution angle calculation section 13, a timer value (t) counted up or down by the timer 33 is set to a predetermined value in parallel with a series of processing in the main routine described above. When the value reaches the value, the CPU 30 executes a timer interrupt process. Therefore, the timer interrupt process will be described below with reference to the flowchart shown in FIG.

When this timer interrupt processing is executed,
First, in step S50 shown in FIG.
0 is the left headlamp 1 stored in the RAM 32
The current position of the lamp indicating the current light distribution angle at 0 (position
_lh) is compared with a lamp target position (mark_lh) indicating a target light distribution angle for the left headlamp unit 10. Then, it is determined whether or not the current light distribution angle is closer to the right than the target light distribution angle. If the result of this determination is that it is rightward, the process proceeds to step S51, and if it is not rightward, the process proceeds to step S53.

At step S51, the CPU 30
Motor driver 22 in left headlamp section 10
, A left driving pulse signal is output. This allows
In the left head lamp unit 10, the motor 21 is driven by the motor driver 22 in response to the left driving pulse signal, and in step S52, the light distribution angle of the lamp 20 is adjusted to the left.

Then, the light distribution angle is determined by the current position of the lamp (positi).
on_lh) and store it in the RAM 32. After this processing, the CPU 30 advances the processing to step S56.

On the other hand, in step S53, the CPU 3
A value of 0 determines whether the current light distribution angle in the left headlamp unit 10 is closer to the left than the target light distribution angle. If the result of this determination is that it is leftward, the process proceeds to step S54, and if it is not leftward, it is determined that the current light distribution angle matches the target light distribution angle.
The process proceeds to step S56.

At step S54, the CPU 30
Motor driver 22 in left headlamp section 10
, A right driving pulse signal is output. This allows
In the left head lamp unit 10, the motor 21 is driven by the motor driver 22 in response to the right driving pulse signal, and in step S55, the light distribution angle of the lamp 20 is adjusted to the right.

Then, the light distribution angle is determined by the current position of the lamp (positi).
on_lh) and store it in the RAM 32. After this processing, the CPU 30 advances the processing to step S56.

In step S56, the CPU 30
The lamp current position (position_rh) of the right headlamp unit 10 stored in the RAM 32 is compared with the lamp target position (mark_rh) of the right headlamp unit 10. Then, it is determined whether or not the current light distribution angle is closer to the right than the target light distribution angle. If the result of this determination is that it is rightward, the process proceeds to step S57, and if it is not rightward, the process proceeds to step S59.

In step S57, the CPU 30
Motor driver 22 in right headlamp section 10
, A left driving pulse signal is output. This allows
In the head lamp unit 10 on the right side, the motor 21 is driven by the motor driver 22 in response to the left drive pulse signal, and in step S58, the light distribution angle of the lamp 20 is adjusted to the left.

Then, the light distribution angle is determined by the current position of the lamp (positi).
on_rh) and store it in the RAM 32. After this processing, the CPU 30 advances the processing to step S62.

On the other hand, in step S59, the CPU 3
A value of 0 determines whether the current light distribution angle in the right headlamp unit 10 is closer to the left than the target light distribution angle. If the result of this determination is that it is leftward, the process proceeds to step S60, and if it is not leftward, it is determined that the current light distribution angle matches the target light distribution angle.
The process proceeds to step S62.

In step S60, the CPU 30
Motor driver 22 in right headlamp section 10
, A right driving pulse signal is output. This allows
In the head lamp unit 10 on the right side, the motor 21 is driven by the motor driver 22 in response to the right drive pulse signal, and in step S61, the light distribution angle of the lamp 20 is adjusted to the right.

The light distribution angle is set to the lamp current position (position_rh), which is a variable, and stored in the RAM 32. After this processing, the CPU 30 proceeds to step S
Proceed to 62.

At step S62, the CPU 30
It is determined whether the control of the light distribution angle in the left and right headlamp units 10 has been completed. At this time, the CPU 30
The lamp target position (mark_lh) and the lamp current position (p) which are variables related to the left headlamp unit 10 stored in M32
osition_lh) and a lamp target position (mark_rh) which is a variable related to the right headlamp unit 10.
If the current lamp position and the current lamp position (position_rh) match, it is determined that the control of the light distribution angles in the left and right headlamp units 10 has been completed. If the result of this determination is that the control of the light distribution angle has been completed, the process proceeds to step S62; otherwise, the process returns from the timer interrupt processing routine to the main routine.

In step S62, the CPU 30
Motors 2 in left and right headlamp sections 10
After confirming that the driving of No. 1 is stopped, the value of the motor driving flag (MONITOR) is set to OFF and stored in the RAM 32. After this processing, the CPU 30 terminates the processing in the timer interrupt processing routine and returns the processing to the main routine.

Light distribution angle calculation unit 13 in light distribution control device 1
Is calculated according to a calculation program stored in the ROM 31.
The operation is performed so as to perform the above arithmetic processing. And
The pair of headlamp units 10 are driven by the motor 21 by the motor driver 22 in accordance with the target light distribution angle calculated by the light distribution angle calculation unit 13, so that the optical axis of the light emitted from the lamp 20 is moved in the horizontal direction. Is controlled.

Here, in steps S32 and S33 described above with reference to FIG. 5, the light distribution angle calculator 13 determines the value of the drive gain when it is determined that the vehicle is traveling on a mountain road. The value is set to be large, and the value of the drive gain is set to be small when it is determined that the vehicle is traveling on an urban road.

As a result, in the light distribution control device 1, when the vehicle is traveling on an urban road, the optical axis of the headlamp section 10 is controlled as shown in FIG. That is, as shown in FIG. 8, the amount of change in the optical axis of the headlamp unit 10 in the left-right direction increases as the degree of change in the traveling direction increases as the steering wheel as the steering unit of the vehicle is largely steered left and right. Will greatly change.
Specifically, the function indicating the amount of change of the optical axis in the headlamp section 10 is represented as a function of the steering angle handle of the steering wheel.
It can be expressed as frector (handle). This function ref
rector (handle) returns a value obtained by multiplying the steering angle steering wheel handle by a constant a. The amount of change in the optical axis of the headlamp unit 10 depends on the lamp 20 in the left-right direction.
Is limited to a certain value when the maximum driving angle is reached.

Further, in the light distribution control device 1, when the vehicle is traveling on a mountain road, the optical axis of the headlamp section 10 is controlled as shown in FIG. That is,
As shown in FIG. 9, a steering wheel as a steering unit of the vehicle is
As the amount of change in the traveling direction increases due to large steering to the left and right, the amount of change in the optical axis of the headlamp section 10 changes more in the left and right direction than when traveling on an urban road. Specifically, the function reflector (handle) relating to the steering angle handle of the handle indicating the amount of change of the optical axis in the headlamp section 10 is represented by the steering angle handle of the handle.
Is multiplied by a constant a ′ that is larger than the constant a when traveling on an urban road. Therefore, when the vehicle is traveling on a mountain road, the rate of change of the optical axis is greater than when the vehicle is traveling on an urban road, as indicated by the arrow in FIG. The amount of change in the optical axis of the headlamp section 10 is limited to a constant value when the maximum drive angle of the lamp 20 is reached in the left-right direction.

Therefore, the light distribution control device 1 according to the present invention
By mounting on the vehicle, for example, as shown in FIG. 10, when traveling on an urban road, even if the traveling direction of the vehicle changes toward a curve, the headlamp unit 10 Reduce the amount of change in the optical axis. FIG. 10A shows a case where the optical axes of the left and right headlamp units 10 are changed outward, respectively.
(B) shows a case where the optical axes of the left and right headlamp units 10 are changed to the inside of the curve.

On the other hand, when the vehicle is traveling on a mountain road, a sharp curve having a smaller radius of curvature than a city road is generally continuous, and the visibility in the left-right direction is often not good. Therefore, only by changing the optical axis of the headlamp unit 10 to the same extent as when traveling on an urban road as in a conventional light distribution control device, as shown in FIG. An area where light from the headlamp section 10 does not reach occurs in the area, and a good view cannot be secured.

On the other hand, in the light distribution control device 1 configured according to the present invention, when the vehicle is traveling on a mountain road, as shown in FIG. The optical axis of the headlamp unit 10 can be changed more than that. Therefore, even when a sharp curve continues while traveling on a mountain road, the optical axis of the headlamp unit 10 can be directed in an optimal direction according to the traveling direction of the vehicle,
It is possible to secure a necessary field of view sufficiently and to drive safely. Although FIG. 12 shows a case where the left and right headlamp units 10 are changed to the inside of the curve,
In the light distribution control device 1, as in the case shown in FIG. 10A, the left and right headlamp units 10 may each change the optical axis outward.

Note that a steep curve having a small radius of curvature is not always continuous on a mountain road. Therefore, even if it is determined that the vehicle is traveling on a mountain road, the light distribution control device 1 determines in step S32 that the drive gain (gain) is obtained only when the amount of change in the traveling direction of the vehicle reaches a predetermined value. ) May be set to a large value. As a result, for example, as shown in FIG. 13, when the vehicle is traveling on a curved mountain road having a large radius of curvature,
The amount of change of the optical axis at 0 can be suppressed as small as when traveling on an urban road. Therefore, even under such running conditions, it is possible to reliably ensure a good view. 13A shows a case where the optical axes of the left and right headlamp units 10 are respectively changed outward, and FIG. 13B shows the case where the optical axes of the left and right headlamp units 10 are set inside the curve. The case where it changes is shown.

[Effects of Embodiment] As described above, in the light distribution control device 1, the traveling state of the vehicle, that is, the traveling direction of the vehicle, whether the vehicle is traveling on an urban road or a mountain road is determined. The ratio of the change direction of the optical axis of the headlamp unit 10 is made variable according to the road conditions. Thus, the light from the headlamp unit 10 can be distributed in a direction in which the viewpoint of the vehicle driver concentrates, and a sufficient field of view in the traveling direction can be secured. Further, since the ratio of the changing direction of the optical axis of the headlamp unit 10 can be controlled in accordance with the traveling state of the vehicle, it is possible to prevent the optical axis from largely changing on a city road, for example. Discomfort and annoyance of the vehicle driver due to the change of the axis can be minimized.

Further, the light distribution control device 1 detects the traveling direction of the vehicle using the steering angle sensor 11 and the vehicle speed sensor. Since these sensors are inexpensive, a mechanism for detecting the traveling direction of the vehicle is used. Can be realized at low cost.

In the above description, the ECU 12
Is input to the target light distribution angle calculation unit 13, and it is determined that the vehicle is traveling on a mountain road by the fact that the rotation speed reaches a predetermined value within a predetermined period. , The ECU 11 and the target light distribution angle calculation unit 13 have a function as a mountain road traveling determination unit.

However, the light distribution control device 1 according to the present invention is not limited to the above-described configuration. For example, the operation mode of the transmission constituting the vehicle is changed from automatic operation to manual operation. May be determined that the vehicle is traveling on a mountain road. In a vehicle in which the operation mode of the transmission is variable between a manual operation mode and an automatic operation mode, the vehicle often switches to a manual operation when traveling on a mountain road.
For example, the target light distribution angle calculation unit 13 may be configured to evaluate the operation mode of the transmission, and thereby determine whether the vehicle is traveling on a mountain road.

Further, the target light distribution angle calculation unit 13 may be configured to determine that the vehicle is traveling on a mountain road based on mountain road traveling information output from a navigation system mounted on the vehicle. Good. In recent years, since a navigation system is widely mounted on a vehicle, the target light distribution angle calculation unit 13 operates in cooperation with such a navigation system so that the vehicle travels on a mountain road. It is possible to easily determine whether or not there is.

Further, in the above description, an example in which the vehicle is driven by the engine has been described. However, the present invention can be applied to other driving sources, for example, those equipped with a fuel cell system. The detection of traveling on a mountain road may be performed according to the amount of power supplied from the motor to the motor.

The above embodiment is an example of the present invention. For this reason, the present invention is not limited to the above-described embodiment, and other than this embodiment, depending on the design, etc., as long as the technical idea according to the present invention is not deviated. Of course, various changes are possible.

[Brief description of the drawings]

FIG. 1 is a functional block diagram of a light distribution control device as an example of a configuration configured by applying the present invention.

FIG. 2 is a schematic diagram showing a configuration example of an address structure in a RAM provided in a target light distribution angle calculation unit of the light distribution control device.

FIG. 3 is a diagram illustrating an example of an operation in the light distribution control device, and is a flowchart illustrating an operation in a main routine.

FIG. 4 is a flowchart showing an example of an operation in the light distribution control device, and is a flowchart showing an operation in a routine for calculating a ring buffer pointer.

FIG. 5 is a diagram illustrating an example of an operation in the light distribution control device, and is a flowchart illustrating an operation in a routine for calculating a drive gain.

FIG. 6 is a flowchart illustrating an example of an operation in the light distribution control device, and is a flowchart illustrating an operation in a routine for calculating a target angle.

FIG. 7 is a diagram illustrating an example of an operation in the light distribution control device, and is a flowchart illustrating an operation in a timer interrupt processing routine.

FIG. 8 is a schematic diagram showing a drive gain when the vehicle is traveling on an urban road in the light distribution control device.

FIG. 9 is a schematic diagram showing a drive gain when the vehicle is traveling on a mountain road in the light distribution control device.

FIG. 10 is a schematic diagram showing a change amount of an optical axis of a head lamp unit when the vehicle is traveling on an urban road in the light distribution control device, and FIG. In the case of changing each axis outward,
(B) shows a case where the optical axes of the left and right headlamp sections are changed to the inside of the curve.

FIG. 11 is a schematic diagram for explaining a problem that occurs when a conventional control method is used when the vehicle is traveling on a mountain road in the light distribution control device.

FIG. 12 is a schematic diagram showing a change amount of an optical axis of a head lamp unit when the vehicle is traveling on a mountain road in the light distribution control device.

FIG. 13 is a schematic diagram for explaining another example of a change amount of the optical axis of the head lamp unit when the vehicle is traveling on a mountain road in the light distribution control device, and FIG.
(B) shows a case where the optical axes of the left and right headlamp sections are changed outward, and (b) shows a case where the optical axes of the left and right headlamp sections are changed inside the curve.

[Explanation of symbols]

 Reference Signs List 1 light distribution control device 10 headlamp unit 11 steering angle sensor 12 ECU (engine control unit) 13 target light distribution angle calculation unit 20 lamp 21 motor 20 motor driver 30 CPU 31 ROM 32 RAM 33 timer 34 serial communication interface 35 I / F Circuit 36 I / O control unit

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Toshiyuki Fujikura 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Prefecture Inside Nissan Motor Co., Ltd. (72) Inventor Tsuyoshi Otsuka 2 Takaracho, Kanagawa-ku, Yokohama City, Kanagawa Nissan F Term (reference) 3K039 AA08 CC01 DC06 FD01 FD12 GA02 JA03

Claims (7)

[Claims] 1. A traveling direction detecting means for detecting a traveling direction of a vehicle, a mountain road traveling determining means for determining whether or not the vehicle is traveling on a mountain road, and a traveling direction of the vehicle detected by the traveling direction detecting means. And, according to the determination result by the mountain road travel determination means,
A target light distribution angle calculating means for calculating a target light distribution angle of light emitted from the lighting means for irradiating the traveling direction of the vehicle; and the lighting means according to the target light distribution angle calculated by the target light distribution angle calculating means. An optical axis changing means for changing the optical axis of the vehicle in the horizontal direction of the vehicle. 2. The method according to claim 1, wherein the target light distribution angle calculating unit determines that the vehicle is not traveling on a mountain road when the vehicle traveling on the mountain road is determined by the mountain road traveling determining unit. The light distribution control device according to claim 1, wherein the target light distribution angle is increased. 3. The target light distribution angle calculating means increases the target light distribution angle only when the amount of change in the traveling direction of the vehicle detected by the traveling direction detection means exceeds a predetermined value. The light distribution control device according to claim 1 or 2, wherein: 4. The vehicle according to claim 1, wherein the traveling direction detecting means detects the traveling direction of the vehicle by detecting at least one of a speed difference between each wheel of the vehicle and a steering angle. The light distribution control device as described in the above. 5. The mountain road running determining means determines that the vehicle is running on a mountain road by continuing the state in which the engine speed of the vehicle has reached a predetermined value for a predetermined period. The light distribution control device according to claim 1. 6. The vehicle according to claim 6, wherein the operation mode of the transmission in the vehicle including the transmission in which the manual operation mode and the automatic operation mode are variable is switched from the automatic operation to the manual operation. The light distribution control device according to claim 1, wherein it is determined that the vehicle is traveling on a mountain road. 7. The vehicle according to claim 1, wherein said mountain road travel determining means determines that the vehicle is traveling on a mountain road based on mountain road travel information output from a navigation system mounted on the vehicle. Light distribution control device.