JPH10326505A - Apparatus for controlling irradiation direction of lighting tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately and speedily determine an initial position of a stepping motor in an irradiation control device for a lighting tool using the stepping motor. SOLUTION: In an irradiation direction control device 1, a driver 4 for directing an irradiation direction of a lighting tool 5 toward a desired direction comprises a stepping motor 6 and a drive mechanism 7 driven by the motor 6. A rotating angle range of the stepping motor 6 depends upon a movable range of the drive mechanism 7. When an instructing device 2 sends, to a controller 3, a command signal for determining an initial position of the driver 4 after the operation of the control device 1, the controller 3 sends, to the stepping motor 6, a control signal inclusive of an angular command beyond the rotating angle range corresponding to the movable range of the drive mechanism 7 and a speed command for rotating the stepping motor 6 at a first rotating speed N1 at that time. Thereafter, the controller 3 sends, to the stepping motor 6, a control signal for rotating the stepping motor 6 by the predetermined number of steps at a second rotating speed N2 (lower than the first rotating speed N1), thereby reducing a vibration width generated when the drive mechanism 7 reaches a limit position within the movable range.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an illumination direction control device for a lamp using a stepping motor as a drive source for directing the illumination direction of the lamp to a desired direction.

[0002]

2. Description of the Related Art There is known a device capable of changing the irradiation direction of a lamp attached to a vehicle by manual operation or automatically, and as the former example, it responds to changes in loading conditions and riding conditions. A so-called leveling device, which adjusts the direction of illumination of a lamp using an operation switch in the vehicle, is known.As an example of the latter, the direction of illumination of a lamp attached to the vehicle due to a change in the attitude of the vehicle is known. There is known a device (so-called auto-leveling device) that constantly corrects the irradiation direction of a lamp so as to cancel the change in the running posture of a vehicle in order to prevent the vehicle from becoming unstable.

This type of apparatus has some driving means for changing the irradiation direction of the lamp within a certain angle range. For example, the tilt angle of the reflecting mirror is controlled by an actuator using a stepping motor. The position detecting means is deliberately used from the viewpoint of cost reduction or a position shift when a large impact is applied to the device (because the rotor is likely to move unless power is supplied to the motor). Some devices are configured not to be attached.

[0004]

By the way, in the above-described apparatus, since the rotor position of the stepping motor is not fixed at the start of the operation, the motor is rotated in a predetermined direction to detect the origin position. The initial operation for positioning (determining the initial position) is performed only once at the position where the rotation stops, that is, at the upper limit position or lower limit position of the movable range of the actuator.

At this time, the phase angle corresponding to the full stroke of the actuator (ie, the distance difference between the upper limit position and the lower limit position) causes the stepping motor to rotate at the same speed as the rotation speed when controlling the irradiation direction of the lamp. If the rotation is performed at the limit position, there is a problem that it is difficult to accurately and quickly locate the position at the limit position (the upper limit position or the lower limit position).

For example, as shown in FIG. 11, the horizontal axis represents time t starting from the start of operation of the apparatus, and the vertical axis represents position x (ie, the rotation angle of the stepping motor or the moving distance of the actuator). When the state of the initial operation is conceptually shown, the movable part of the actuator is t = 0 and x =
When the stepping motor is rotated at the speed indicated by the arrow L from the state of being located at x0, the motor may rotate beyond the origin 0 of the position coordinates (for example, the lower limit of the movable range of the actuator). Since it is not allowed, vibration occurs and rebound occurs as shown. Assuming that the width of the vibration is “Δx”, it is desirable that Δx = 0 ideally when the rotation of the stepping motor is stopped. However, in the above method, since the value of Δx is large, an accurate origin position is recognized. Is difficult to do.

Accordingly, an object of the present invention is to determine an initial position of a motor accurately and quickly in a lighting control device for a lamp using a stepping motor.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is directed to a case where a command signal for determining an initial position of a driving means is transmitted to a control means after the operation of the apparatus. The control means sends to the stepping motor a control signal including an angle command exceeding a rotation angle range corresponding to the movable range of the drive mechanism and a speed command for rotating the stepping motor at the first rotation speed. Then, the control means sends a control signal to the stepping motor to rotate the stepping motor by a predetermined number of steps at a second rotation speed lower than the first rotation speed.

Therefore, according to the present invention, in determining the initial position of the driving means, first, the stepping motor is rotated at the first rotation speed, and after the stepping motor stops rotating at an angle larger than that, Since the rotation is performed at the lower second rotation speed, the width of the rebound due to the vibration can be reduced.

[0010]

FIG. 1 shows a basic configuration of an apparatus according to the present invention.

The irradiation direction control device 1 includes a commanding unit 2, a control unit 3, and a driving unit 4. A lamp 5 whose irradiation direction is controlled from the control unit 3 via the driving unit 4 includes, for example, a vehicle. In the case of a lamp, a headlamp (a fog lamp, a cornering lamp, and the like are included in addition to a headlamp in a narrow sense).

The driving means 4 is provided to direct the irradiation direction of the lamp 5 in a desired direction, and includes a stepping motor 6 and a driving mechanism 7 driven by the stepping motor 6. The rotation angle range of the stepping motor 6 is limited by the movable range of the drive mechanism 7.

The command means 2 sends a command signal for determining the initial position of the drive means 4 to the control means 3 after the operation of the apparatus 1, and the control means 3 receives the command signal. First, an angle command exceeding a rotation angle range corresponding to the movable range of the drive mechanism 7 and a speed command for rotating the stepping motor 6 at a first rotation speed (hereinafter referred to as “N1”) at that time are issued. The control signal is transmitted to the stepping motor 6. The command means 2 is a signal necessary for controlling the irradiation direction of the lamp 5 to the control means 3 (for example, an operation signal when the irradiation direction of the lamp is controlled by manual operation). ,Also,
When the irradiation direction of the lamp is automatically controlled, it is a detection signal (a detection signal of a vehicle attitude in an auto-leveling device) which is a basis of the control. ) Is sent to the control means 3.

Then, the control means 3 rotates the stepping motor 6 by a predetermined number of steps at a second rotation speed (hereinafter referred to as "N2") which is lower than the first rotation speed N1. A control signal for causing the stepping motor 6 is sent.

FIGS. 2 and 3 conceptually show a rotational speed command sent from the control means 3 to the stepping motor 6 during the initial operation. The horizontal axis represents time t, and the vertical axis represents the rotational speed N. Indicates the change of the speed command.

A graph line g1 shown by a solid line in FIG. 2 shows a case where the rotational speeds N1 and N2 are set to constant values, and 0 ≦
During the period t ≦ tc, the rotation speed N1 of the stepping motor 6 is fixed at Na, and during the period tc <t ≦ te, the rotation speed N2 of the stepping motor 6 is a value Nb (<< Na) that is sufficiently lower than Na. Is changed to It is to be noted that the present invention is not limited to this, and as shown by a one-dot chain line graph line g2 in FIG. Is preferably switched in a small number of steps as shown by a graph line g1.

FIG. 3 shows an example in which the rotation speed is continuously reduced. In the control shown by a graph line g3 in FIG. 3, a line segment g in which the first rotation speed N1 is inclined downward to the right.
After the linear deceleration as shown by 3a, the period tc <t
For the second rotation speed N2 at ≦ te, the line segment g
As shown by a line segment g3b having a smaller inclination than 3a, the speed is slowly reduced. It is to be noted that the present invention is not limited to such linear deceleration control, and it is also possible to perform curvilinear deceleration control as shown by a two-dot chain line in FIG.

As described above, in the deceleration control of the stepping motor 6 at the time of the initial operation, N1 or N2 is a constant value, or N1 or N2 is decelerated stepwise or continuously over time. And t
The time point e can be specified as a time command by the control means 3, but if it is specified as a predetermined number of steps (that is, the time point te depends on the rotation speed), the accuracy of the positioning of the origin can be improved. Can be higher. That is, since the maximum width of the rebound of the drive mechanism 7 that occurs in the initial period of the period tc <t ≦ te is substantially determined by the first rotation speed N1, the stepping motor 6 is controlled to operate at the second rotation speed N2 within the maximum width. When rotated at a speed that does not cause rebound, the width of the rebound can be further reduced.

The method of changing the irradiation direction of the lamp 5 by the driving means 4 includes a method of changing the irradiation direction by tilting the entire lamp by the driving means 4 and a method of driving a part of the components of the lamp. There is a way to control. For example, a method of changing the direction of reflected light by tilting the reflecting mirror in the vertical plane by the driving means 4, a method of changing the direction of irradiation light passing through the lens by tilting the lens by the driving means 4, and the like. Can be mentioned. In addition, instead of tilting the entire reflecting mirror or lens, the main part of the irradiation light may be changed in a desired direction by controlling the position of a part thereof, or the shade may be changed. By moving the light in a predetermined direction by the driving means 4 to change the light / dark boundary in the light distribution pattern of the lamp up and down, or by driving a combination of a reflecting mirror and a light source, a lens and a reflecting mirror, or a lens and a shade. Various embodiments are possible depending on the combination of the optical components of the lamp, such as a method of changing the direction of irradiation light in the vertical direction by moving together with the means 4.

[0020]

4 to 10 show an embodiment in which the present invention is applied to an irradiation direction control device for a vehicle lamp.

The device 8 is an auto-leveling device for automatically following the change in the attitude of the vehicle to correct the irradiation direction of the lamp. As shown in FIG. (Electronic Control Unit) 9 which performs an input signal to the ECU 9, a vehicle height sensor 10 provided on each of axle parts before and after the vehicle,
11, a lighting instruction signal from the headlamp switch 12 (hereinafter, referred to as "SW"), an ignition signal as an engine start signal (hereinafter, referred to as "Ig"), and a detection signal from the vehicle speed sensor 13. is there.

The vehicle height sensors 10 and 11 are means for detecting the vehicle posture, and are provided for detecting the vehicle posture during stationary and / or motion (including the vertical inclination in the traveling direction of the vehicle). , A method of detecting the amount of expansion and contraction of the suspension of the axle, a method of measuring the distance between the vehicle height sensor and the ground by using a detection wave such as an ultrasonic wave or a laser beam, or a method of using a gyro sensor (such as a motorcycle). Is used.) And the like.

The correction signal output from the ECU 9 is sent to driving units 14 and 14 'for controlling the irradiation directions of the lamps provided on the left and right of the front part of the vehicle. The driving units 14, 1
4 'includes stepping motors 14a, 1
4'a and their motor drive circuits 14b and 14'b are provided. Note that the stepping motors 14a, 1
By the rotation of 4'a, for example, the sliding axes of the actuators 14c and 14'c provided in the lamps 15 and 15 'are moved in the front-rear direction of the vehicle, whereby the reflector is tilted in the vertical plane. As a result, the direction of the optical axis of the reflecting mirror in the lamp is changed, and the irradiation directions of the lamps 15 and 15 'are respectively controlled.

FIG. 5 shows an example of the configuration of a main part. A power supply circuit 17 for supplying power to a computer 16 which is a control center is provided with a diode 18 and an SW signal and an Ig signal.
The signal is input through an OR (sum) circuit 19 formed by 18 '(this OR signal corresponds to the signal from the command means 2 described above). In other words, the SW signal in this case is an H (high) level signal when instructing to light, an L (low) level signal when instructing to extinguish, and the Ig signal is an H level signal when the engine is started. Signal.

The power supply circuit 17 outputs an H signal when the SW signal or the Ig signal is H.
The power supply is supplied to the computer 16 in the case of the level signal.

The OR signal of the SW signal and the Ig signal obtained by the diodes 20, 20 'is sent out as a power supply voltage to the coils 21, 21,... Of the stepping motor 14a. Note that the motor drive circuit 14b has a semiconductor switch element, a damper, and the like that directly drives each phase coil 21 of the stepping motor 14a.

That is, in this circuit, when the SW signal or the Ig signal is an H level signal, the power supply from the power supply circuit 17 to the computer 16 and the power supply to the stepping motor 14a are performed. Of the stepping motor 14a via the motor drive circuit 14b
The full-stroke drive 4c is performed only once at first, and the origin is located.

FIG. 6 is a flowchart showing an example of a control procedure relating to the initial operation.
When instructed by the signal, in step S1, the stepping motor 14a is turned in a predetermined direction (the direction in which the optical axis of the lamp or the reflecting mirror is directed downward with respect to the horizontal plane), and the rotation angle corresponding to the full stroke of the actuator 14c. (Phase angle) and rotate at the rotation speed N1.

In S2, it is determined whether or not the rotation instruction in S1 has been completed, that is, whether or not the drive for the full stroke of the actuator 14c has been completed. If not, the process returns to S1.

When the actuator 14c reaches the limit of its movable range, rebound occurs.
Then, the stepping motor 14a is rotated at a rotation speed N2 set to a low value so as not to cause rebound (the pulse rate is set to a low frequency), and
The number of rotation steps is a predetermined value (this is referred to as “TS”).
Defined in For example, if the pulse rate corresponding to the rotation speed N1 is 150 to 200 PPS (Pulse Per
If the maximum value of the rebound is supposed to be a distance corresponding to 10 steps in the case of about (Second), this 1
Stepping motor 1 by adding several steps to 0 steps
The value of TS is defined so as to be an integral multiple of the minimum drive step number of 4a.

In S4, it is determined whether or not the driving of the number of steps TS has been completed. At the end, the process proceeds to the next S5, but if not completed, the process returns to S3.

In step S5, in order to set a reference position for auto-leveling (that is, a reference position for controlling the irradiation direction of the lamp), the stepping motor 14a is rotated at a rotation speed N1 in the opposite direction to that before, and the actuator 14 is rotated.
Drive c. Then, in the next S6, the actuator 1
It is determined whether or not the driving of 4c has been completed. When the driving has been completed, the initial operation is completed. When the driving has not been completed, the process returns to S5.

FIGS. 7 to 10 show the temporal change (the time axis is represented by "t") of the velocity (this is represented by "V") and the position (this is represented by "x") of the moving axis of the actuator 14c. 7 and 8 show the case where the initial operation is performed in a situation where the movement axis of the actuator 14c is near its upper limit position. FIGS. 9 and 10 show the case where the above-described initial operation is performed in a situation where the movement axis of the actuator 14c is in the middle of its movable range. Note that “xn” in the drawing indicates an x value corresponding to the reference position of the auto-leveling.

The speed V is, as shown in FIG.
“V1” for ≦ ta, “V2” for period ta <t ≦ tb, “−V1” for period tb <t ≦ tn, and period tb <t ≦ tn indicates a period of transition to the reference position of auto-leveling. ing.

As shown in FIG. 8, a deviation h (distance from the lower limit position) occurs when the moving axis of the actuator 14c strikes the lower limit position and rebounds at t = ta, and thereafter the deviation h gradually increases. And become smaller,
At the time of t = tb, it becomes almost zero.

In FIG. 9, since the moving axis of the actuator 14c reaches its lower limit position before reaching t = ta, the moving axis rebounds during the period Tr.

Therefore, as shown in FIG. 10, t = ta '.
At the time point (<ta), the movement axis of the actuator 14c hits the lower limit position, and rebound is repeated. During that time, as shown in the enlarged circle in FIG. Occurs almost periodically,
Since the deviation h is within several steps when approaching the time point of t = tb, the positioning error is reduced.

The time tn required to reach x = xn
However, if the Ig signal is set to the H signal and the SW signal is immediately set to the H signal and set so as to be shorter than the time required for the lamp to light, the initial operation can be completed before the lamp is turned on. it can. In other words, if the initial operation is delayed, the irradiation direction of the lamp changes, which may cause a driver of the vehicle to feel distrust.

[0039]

As is apparent from the above description, according to the first aspect of the present invention, when determining the initial position of the driving means, first, the stepping motor is rotated at the first rotation speed. Since the stepping motor stops rotating at an angle larger than that, and then rotates the motor at the lower second rotation speed, the width of the rebound due to the vibration is reduced.
The accuracy of positioning the origin is increased, and a long time is not spent for that.

According to the second aspect of the present invention, by setting the first rotation speed or the second rotation speed to a constant value, it is possible to simplify the control and the device configuration and to speed up the initial operation.

According to the third aspect of the present invention, the first rotation speed or the second rotation speed is reduced stepwise or continuously over time, so that the drive mechanism moves to the limit position of the movable range. It is possible to reduce the width of the vibration that occurs after the time when the vibration has been reached.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a basic configuration of an apparatus according to the present invention.

FIG. 2 is a graph showing an example of initial operation control.

FIG. 3 is a graph showing an example of an initial operation control different from that of FIG. 2;

FIG. 4 shows an embodiment of the present invention together with FIG. 5 to FIG. 10, and FIG. 4 is a block diagram showing a configuration of the apparatus.

FIG. 5 is a block diagram showing a configuration of a main part of the device.

FIG. 6 is a flowchart illustrating a flow of an initial operation.

FIG. 7 shows a case where an initial operation is performed in a state where the moving axis of the actuator is near its upper limit position together with FIG. 8, and FIG. 7 is an explanatory diagram showing a temporal change in the speed of the moving axis.

FIG. 8 is an explanatory diagram showing a temporal change in the position of a moving axis.

9 shows a case where the initial operation is performed in a state where the moving axis of the actuator is in the middle of the movable range together with FIG. 10, and FIG. 9 is an explanatory diagram showing a temporal change in the speed of the moving axis. .

FIG. 10 is an explanatory diagram showing a temporal change in the position of a moving axis.

FIG. 11 is an explanatory diagram of a conventional problem.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 irradiation direction control device for lamp 2 commanding device 3 control device 4 driving device 5 lamp device 6 stepping motor 7 driving mechanism

Claims (3)

[Claims] 1. A driving means for directing an irradiation direction of a lamp in a desired direction includes a stepping motor and a driving mechanism driven by the stepping motor, and a rotation angle of the stepping motor depends on a movable range of the driving mechanism. In the illumination direction control device for a lamp configured to have a limited range, (a) the command device sends a command signal for determining an initial position of the driving device to the control device after the device is operated; (B) When the control means receives a command signal from the command means, an angle command exceeding the rotation angle range corresponding to the movable range of the drive mechanism and, at that time, rotating the stepping motor at the first rotation speed. The control means sends a control signal including the speed command to the stepping motor; (c) after the angle command in (b), the control signal is output from the first rotation speed. An illumination direction control device for a lamp, wherein the control means sends a control signal to the stepping motor to rotate the stepping motor by a predetermined number of steps at a low second rotation speed. 2. The illumination direction control device for a lamp according to claim 1, wherein the first rotation speed or the second rotation speed is a constant value. 3. The lighting direction control device for a lamp according to claim 1, wherein the first rotation speed or the second rotation speed is reduced stepwise or continuously over time. Irradiation direction control device.