JP2009083841A - Lamp system and lamp deflection control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lamp system and a lamp deflection control method, securing driving safety of a vehicle without giving discomfort of a deflection control in a lamp irradiating direction to a driver, in an AFS of an automobile. <P>SOLUTION: A deflection control means (ECU) 10 performs the deflection control of irradiating directions of lamps RHL, LHL. In the deflection control means 10, a deflection angle calculating section calculating a deflection angle of the irradiating direction based on a steering angle, and a dead band processing means 13 setting a dead band with respect to the steering angle inputted to the deflection control means 11 and changing a dead band to follow the steering angle, are provided. The dead band processing means 13 has means 131-134 changing the dead band so that the steering angle is always included within the dead band, and a means 135 outputting, to the deflection control means 11, a reference value of the dead band as an output steering angle for deflection calculation. By controlling the dead band to follow to the steering angle, fluctuation in lamp irradiating direction in every possible steering condition is prevented. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a headlamp for a vehicle such as an automobile, and more particularly to an AFS (Adaptive Front-lighting System) that controls deflection of the irradiation direction of a headlamp following a change in the steering angle of the vehicle. The present invention relates to an applied lamp system and its deflection control method.

  In order to enhance the safety of driving and driving of an automobile, an AFS has been proposed that controls the deflection of the headlamp irradiation direction in the left-right direction following the steering angle of the steering wheel. According to this system, the headlamp irradiation direction can be directed not only in the straight traveling direction but also in the direction in which the driver steers, that is, the direction in which the vehicle is about to travel, thereby improving driving safety. Effective above. In recent years, as disclosed in Patent Document 1, not only the steering angle but also the vehicle speed of the vehicle is detected, and the direction in which the headlamp is irradiated is controlled based on the vehicle speed and the steering angle. A system has been proposed that responds accurately to changes in the vehicle and does not give the driver a sense of incongruity.

However, in the AFS in consideration of such a vehicle speed, the backlash of the gear mechanism interposed between the steering wheel and the wheel steering mechanism is changed because the irradiation direction of the headlamp is changed based on the steering angle of the steering wheel. As a result, a deviation occurs between the actual steering angle and the steering direction of the wheel, and so-called play occurs. Due to this play, when the steering wheel is steered at a minute angle, the irradiation direction of the headlamp is changed by the detected steering angle even though the wheel is not actually steered. In order to prevent this, a dead zone is provided in Patent Documents 1 and 2, so that the irradiation direction is not changed when the steering wheel is steered within the angle of the dead zone. In Patent Document 1, the width of the dead zone is changed according to the difference in vehicle speed, the dead zone width during low speed running is increased even during high speed running, and even if the steering angle changes slightly during straight running at low speed, the ramp The irradiation direction is not changed. In addition, Patent Document 2 prevents fluctuations in the lamp irradiation direction during straight traveling, while providing a dead zone when the steering angle is switched back to a predetermined steering angle, regardless of the steering wheel steering direction. By setting the dead zone width at the time of switching back to be narrower than the dead zone width at the time of straight traveling, the followability of the irradiation direction of the lamp at the time of switching back the steering is improved.
Japanese Patent Laying-Open No. 2005-29080 JP-A-5-92738

  The dead zone set during straight running in Patent Documents 1 and 2 is effective in preventing fluctuations in the irradiation direction of the lamp with respect to fluctuations in the steering angle when the steering angle is 0 degrees, that is, straight running. However, since the steering angle is in a region outside the dead zone width from 0 degrees when the vehicle is running on a curved road by steering, the dead zone during straight running does not function. For this reason, when the steering is slightly changed during traveling on a curved road, the irradiation direction of the headlamps fluctuates following this, causing the driver to feel uncomfortable. The technique of Patent Document 2 is configured such that the dead zone acts even when the steering is switched back at a predetermined steering angle. Therefore, when the steering changes in the switching back direction, the variation in the irradiation direction of the lamp is caused by the dead zone. However, since there is no dead zone in the steering direction, it is impossible to prevent fluctuations in the lamp irradiation direction in the same direction.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a lamp system and a lamp deflection control method capable of preventing a change in a lamp irradiation direction due to a minute change in a steering angle even when steering is performed at an arbitrary angle.

  A first lamp system according to the present invention includes a deflection control unit that detects a steering angle of a vehicle and performs deflection control of the irradiation direction of the lamp based on the detected steering angle. A deflection angle calculating means for calculating a deflection angle in the irradiation direction of the lamp, and a dead zone processing means for setting a dead zone for the steering angle input to the deflection control means and changing the dead zone following the steering angle. The dead zone processing means changes the dead zone by the amount of the steering angle so that the steering angle enters the dead zone when the steering angle goes out of the dead zone, and outputs the reference value of the dead zone for the deflection angle calculation. It outputs to a deflection control means as a steering angle, It is characterized by the above-mentioned.

  A second lamp system according to the present invention includes a deflection control unit that detects a steering angle of a vehicle and controls deflection of a lamp irradiation direction based on the detected steering angle. A deflection angle calculating means for calculating a deflection angle in the irradiation direction of the lamp, and a dead zone processing means for setting a dead zone for the steering angle input to the deflection control means and changing the dead zone following the steering angle. The dead zone processing means changes the dead zone by the amount of the steering angle so that the steering angle enters the dead zone when the steering angle goes out of the dead zone, and deflects the steering angle when it first enters the dead zone The output steering angle for angle calculation is output to the deflection control means.

  A third lamp system of the present invention includes a deflection control unit that detects a steering angle of a vehicle and performs deflection control of the irradiation direction of the lamp based on the detected steering angle. A deflection angle calculating means for calculating a deflection angle in the irradiation direction of the lamp, and a dead zone processing means for setting a dead zone for the steering angle input to the deflection control means and changing the dead zone following the steering angle. The dead zone processing means changes the dead zone by the amount of the steering angle so that the steering angle enters the dead zone when the steering angle goes out of the dead zone, and enters the dead zone when the steering angle enters the dead zone. The initial steering angle at this time is set to a reference value for the dead zone, and the reference value is output to the deflection control means as an output steering angle for calculating a deflection angle.

  A first lamp deflection control method according to the present invention detects a steering angle of a vehicle, calculates a deflection angle in the lamp irradiation direction based on the detected steering angle, and deflects the lamp irradiation direction to the calculated deflection angle. A ramp deflection control method for controlling, wherein the dead zone is changed so that the steering angle enters the dead zone based on the detected steering angle, and the reference value set in the dead zone is set as the output steering angle, and the output steering angle is set. The deflection angle is calculated by the above.

  The second lamp deflection control method according to the present invention detects the steering angle of the vehicle, calculates the deflection angle of the lamp irradiation direction based on the detected steering angle, and deflects the lamp irradiation direction to the calculated deflection angle. A ramp deflection control method for controlling, changing the dead zone so that the steering angle enters the dead zone based on the detected steering angle, and setting the steering angle when first entering the dead zone as the output steering angle, The deflection angle is calculated with the output steering angle.

  The third lamp change control method according to the present invention detects the steering angle of the vehicle, calculates the deflection angle of the lamp irradiation direction based on the detected steering angle, and deflects the lamp irradiation direction to the calculated deflection angle. A ramp deflection control method for controlling, wherein a reference value is set based on the detected steering angle, the dead zone is changed so that the steering angle falls within the dead zone, and the steering angle enters the dead zone based on the reference value. The initial steering angle at that time is set as a reference value, this reference value is set as the output steering angle, and the deflection angle is calculated using this output steering angle. In this case, the difference between the initial steering angle when entering the dead zone and the reference value immediately before entering the dead zone is taken, and the reference value is updated by a value smaller than the predetermined value until the difference falls within a predetermined value. It is preferable to repeat the process.

  According to the present invention, control is performed such that the dead zone is changed following the steering angle of the vehicle so that the steering angle enters the dead zone, and when the steering angle enters the dead zone, the output steering angle is specified as a predetermined angle. Therefore, the dead zone functions even when steering other than straight running, such as when driving on a curved road, and even if the steering angle fluctuates within a minute angle range, that is, the dead zone width, the deflection of the ramp Control is suppressed and fluctuations in the illumination direction of the lamp are prevented. On the other hand, when the driver intentionally steers, the dead zone changes when the steering angle goes out of the dead zone, and the output steering angle output from the dead zone processing means changes accordingly, and the deflection angle is changed. Calculation is performed and deflection control of the irradiation direction of the lamp by AFS is executed. This prevents the deflection control in the irradiation direction not following the steering in the AFS, thereby preventing the driver from feeling uncomfortable.

  A first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of Embodiment 1 applied to left and right headlamps of an automobile. The right headlamp RHL and the left headlamp LHL have basically the same configuration, and are formed of a projector-type lamp unit in a container-shaped lamp housing LH having an open front surface and a through-hole cover. The low beam lamps RLBL and LLBL for performing the illumination are internally provided. The lamp housing LH also includes high beam lamps RHBL and LHBL each including a lamp unit for performing illumination with a high beam distribution. The low beam lamps RLBL and LLBL are configured such that the irradiation direction Lx can be controlled to be deflected horizontally and horizontally by a swivel mechanism SV.

  FIG. 2 is a schematic longitudinal sectional view showing the configuration of the low beam lamp RLBL and the swivel mechanism SV in the right headlamp RHL. The lamp housing LH includes a lamp body 41 having an opening on the front surface and a light-transmissive through cover 42 attached to the front opening of the lamp body 41. The lamp housing LH has a substantially U-shape in the lamp housing LH. A bracket 43 is fixed, and a projector-type lamp 50 constituting the low beam lamp RLBL is supported in the bracket 43 so as to be rotatable in the horizontal and horizontal directions on the upper and lower rotating shafts 44. The projector-type lamp 50 includes a rotating semi-elliptical reflector 51, an annular spacer 52, and a condensing lens 53 made of a convex lens, and a light source 54 such as a discharge bulb inside. Since it is already widely known, detailed description is omitted. An actuator 45 having a motor as a drive source is fixed to the lower surface side of the bracket 43, and a rotation output shaft 45a of the actuator 45 is connected to a lower end portion of the rotation shaft 44 to constitute the swivel mechanism SV. ing. In the swivel mechanism SV, a projector-type lamp 50, that is, a low beam lamp RLBL, is driven by inputting a deflection control signal, which will be described later, into the actuator 45. In this way, the lamp optical axis, that is, the irradiation direction Lx is deflection-controlled. The same applies to the left headlamp LHL.

  In FIG. 1, each swivel mechanism SV of the left and right headlamps RHL and LHL is connected to an ECU (Electronic Control Unit) 10, and the deflection operation in the left-right direction is controlled by the ECU 10. The ECU 10 is connected to a steering angle sensor 20 that detects the steering angle of the steering wheel STW and a vehicle speed sensor 30 that detects the vehicle speed of the host vehicle. The ECU 10 receives the steering angle signal from the steering angle sensor 20 and the vehicle speed. The swivel mechanism SV is controlled based on the vehicle speed signal from the sensor 30, and the irradiation direction of the low beam lamps RLBL, LLBL is controlled.

  Based on the steering angle signal from the steering angle sensor 20 and the vehicle speed signal from the vehicle speed sensor 30, the ECU 10 determines the deflection angle in the irradiation direction Lx of the low beam lamps RLBL and LLBL with respect to the steering angle of the vehicle. A deflection angle calculation unit 11 that calculates an angle formed with respect to the straight traveling direction of the vehicle, and a swivel that outputs a swivel control signal for controlling the swivel mechanism SV based on the deflection angle signal calculated by the deflection angle calculation unit 11. And a control unit 12. This swivel control signal is input to the swivel mechanism SV provided in each head lamp RHL, LHL so that the irradiation direction Lx of the low beam lamps RLBL, LLBL in the head lamps RHL, LHL is directed to the direction of the calculated deflection angle. Control is executed.

  In addition, the ECU 10 is provided with a dead zone processing unit 13 that performs a dead zone process on the steering angle signal before the steering angle signal from the steering angle sensor 20 is input to the deflection angle calculation unit 11. The dead zone processing unit 13 includes a dead zone determining unit 131 that determines whether or not the steering angle, which is information of the steering angle signal, is within the range of the dead zone width. The dead zone determining unit 131 includes a dead zone setting unit. The dead band width from 132 is input. The dead zone setting unit 132 includes a reference value storage unit 133 that stores a reference value serving as a median value of the dead zone width, and a dead zone width that is preset and set to a predetermined equal width in the horizontal direction of the reference value. The dead zone width is set in the dead zone setting unit 132 based on the reference value and the dead zone width. An output steering angle setting unit 135 is connected to the dead zone determination unit 131. When the dead zone determination unit 131 determines that the steering angle falls within the range of the dead zone width, the output steering angle setting unit 135 then Is output as an output steering angle. On the other hand, when the dead zone determination unit 131 determines that the steering angle is not within the dead zone width range, the dead zone determination unit 131 includes a difference value calculation unit 136 that takes a difference between the two, and the calculated difference value is used as the reference value storage unit. To 133.

  A control operation of the irradiation direction of the headlamp in the AFS control in the headlamp system having the above configuration will be described. In the flowchart of FIG. 3, the ECU 10 takes in the steering angle signal from the steering angle sensor 20 and the vehicle speed signal from the vehicle speed sensor 30 and inputs them to the deflection angle calculation unit 11. At this time, the dead zone processing unit 13 receives the steering angle signal. Process (S10) is executed.

  In the dead zone processing S10, the dead zone processing unit 13 inputs the steering angle, which is information of the steering angle signal output from the steering angle sensor 20, to the dead zone determination unit 131 (S101), and is set in the dead zone determination unit 131 accordingly. It is compared with the dead zone width (S102). In the following description, the magnitude of the steering angle and the dead zone means that the absolute value of the detected steering angle, that is, the steering angle increases when the straight traveling direction is set to 0 degree. It is determined whether or not the steering angle is in the dead zone. When the steering angle is not more than the maximum value of the dead zone and not less than the minimum value, it is determined that the steering angle is in the dead zone. On the other hand, when the steering angle is larger than the maximum value of the dead zone or smaller than the minimum value, it is determined that the vehicle is not in the dead zone.

  When it is determined that the steering angle is in the dead zone, the reference value stored in the reference value storage unit 133 at that time is output as the output steering angle (S103). On the other hand, when it is determined that the steering angle is not in the dead zone, the difference between the steering angle and the dead zone is calculated (S104). Then, based on the difference value, the reference value stored in the reference value storage unit 133 is updated (changed) (S105). That is, when the steering angle is larger than the maximum value of the dead zone, a value obtained by subtracting the maximum value of the dead zone from the steering angle is obtained, and this difference value is fed back to the reference value storage unit 133 to increase the reference value by the difference value. Conversely, when the steering angle is smaller than the minimum value of the dead zone, a value obtained by subtracting the minimum value of the dead zone from the steering angle (becomes a negative value) is obtained, and this difference value is fed back to the reference value storage unit 133 as a reference value. Is reduced by the difference value. As a result, the reference value stored in the reference value storage unit 133 is changed, and the dead zone setting unit 132 sets a new dead zone based on the changed reference value and the dead zone width stored in the dead zone storage unit 134. It sets (S106). That is, when the steering angle is larger than the maximum value of the dead zone, the difference is moved to the larger steering angle, and when the steering angle is smaller than the minimum value of the dead zone, the difference is moved to the smaller steering angle. Is done.

  As described above, since the dead zone is changed following the difference between the steering angle and the dead zone, the steering angle is controlled so that it always enters the dead zone. At the same time, the dead zone determination unit 131 confirms that the steering angle has entered the dead zone, and outputs the reference value at that time to the deflection angle calculation unit 11 as an output steering angle (S103). The deflection angle calculation unit 11 calculates an appropriate deflection angle (swivel angle) of the irradiation direction Lx of the headlamp with respect to the steering angle of the host vehicle based on the output steering angle and the vehicle speed as information of the vehicle speed signal, and calculates the calculated deflection. The angle is output to the swivel control unit 12 (S11). The swivel control unit 12 generates a swivel control signal in which a swivel control amount is set to deflect the low beam lamps RLBL and LLBL in the direction of the deflection angle based on the input deflection angle, and outputs the swivel control signal to the swivel mechanism SV (S12). . Thus, the swivel mechanism SV controls the deflection of the low beam lamps RLBL and LLBL by the swivel control signal, and controls the deflection of the irradiation direction Lx of each lamp in a direction suitable for the current driving situation of the automobile.

  The above operation will be described with reference to the timing chart of FIG. In this example, the default reference value stored in the reference value storage unit 133 is 0 degrees, and the default dead band width stored in the dead band storage unit 134 is ± 2 degrees with respect to the reference value. To do. Here, + means rightward and-means leftward. In the dead zone determining unit 131, the steering angle is ± 2 degrees, that is, the left of the angle range symmetrical to the left and right across the steering angle of 0 degrees in the straight traveling direction. The range from 2 degrees to 2 degrees to the right is the dead zone width. The dead zone width is shown as a stipple area.

  If the steering angle is in the range of −2 degrees to +2 degrees at the timing t1, the steering angle is in the dead zone, and the dead zone determination unit 131 stores the reference value at that time, that is, the reference value storage unit 133. The reference value of 0 degrees is output as the output steering angle. Therefore, even when the steering angle is varied within the range of -2 degrees to +2 degrees, the output steering angle is 0 degrees. As a result, the deflection angle calculation unit 11 calculates the deflection angle with the output steering angle set to 0 degree. Therefore, the irradiation direction Lx of the lamps (left and right low beam lamps: the same applies below) is set to 0 degree by the swivel operation in the swivel mechanism SV. Be controlled.

  When the steering angle is steered in one direction and the steering angle exceeds +2 degrees, the dead zone determination unit 131 determines that the steering angle has come out of the dead zone, and in response to this, the difference value calculation unit 136 exceeds the dead zone width. The steering angle is calculated as a difference value of the steering angle. For example, when the steering angle becomes +6 degrees at timing t <b> 2, the steering angle difference calculation unit calculates +6 − (+ 2) = + 4 as a difference value, and inputs this difference value +4 to the reference value storage unit 133. As a result, the reference value storage unit 133 adds +4 degrees to the default of 0 degrees, and updates the reference value to +4 degrees. Therefore, the dead band setting unit 132 sets the new dead band width to +2 degrees to +6 degrees between -2 degrees to +2 degrees of the dead band width storage section and +4 degrees of the new reference value, and sets this new dead band width. This is output to the dead zone determination unit 131, and the dead zone determination unit 131 makes a determination by comparing the new dead zone width with the next input steering angle.

  Next, if the detected steering angle is in the range of +2 degrees to +6 degrees, the dead zone determination unit 131 determines that the steering angle is in the dead zone, and uses the reference value at that time, that is, +4 degrees as the output steering angle. Output. As a result, even when the steering angle varies within the range of +2 degrees to +6 degrees, the output steering angle becomes +4 degrees, and the deflection angle calculation unit 11 calculates the deflection angle by setting the output steering angle to +4 degrees. The swivel operation in the mechanism SV controls the lamp irradiation direction Lx to a deflection angle corresponding to a steering angle of +4 degrees, that is, 4 degrees to the right.

  By continuing the above control, when the steering angle is changed as shown by a thick broken line in FIG. 4, the dead zone width is changed following the stippled region. In particular, when the steering angle becomes +15 degrees at the timing t3, the dead band width is set to +11 degrees to +15 degrees, so even if the steering angle fluctuates within the range of +11 degrees to +15 degrees, the dead band determination unit 131 The output steering angle indicated by the thick solid line in the figure is controlled to +13 degrees which is the reference value at that time, and the lamp irradiation direction Lx is controlled to an angle corresponding to the steering angle of 13 degrees to the right.

  Further, when the steering angle is turned back toward the low angle direction, that is, 0 degree which is the straight traveling direction, for example, when the steering angle is reduced to +10 degrees at timing t4, the dead zone width becomes smaller than the minimum value +11 degrees, Since the difference value between the two is -1 degree, the reference value is decremented from +13 degrees to -1 to +12 degrees, and the dead band width is +10 degrees to +14 degrees. When the steering angle is sequentially decreased in this way, the reference value of the dead zone width is gradually reduced along with this, and finally, at the timing t5, when the steering angle becomes 0 degree, the dead zone width becomes 0 degree to +4 degree. Become. At this time, since the reference value is finally +2 degrees, even when the steering wheel STW is actually returned to 0 degrees, that is, to the straight traveling direction, the steering angle is set to +2 degrees, and the lamp irradiation direction Lx is slightly This is corrected when the steering wheel STW is steered to the left and the steering angle is greatly increased to the left from the dead zone.

  Although the above description has been given of the case where the steering is steered in the + direction, that is, the right direction and turned back, the same applies to the case where the steering is steered in the-direction, that is, the left direction. Even in this case, the reference value stored in the reference value storage unit 133 is changed to the − direction when the steering angle goes out of the dead zone width in the − direction, and when the steering angle goes out to the + direction, the reference value becomes the + direction. Will be changed.

  In this way, the dead zone is changed following the steering angle obtained by detecting the steering of the steering wheel STW, and the control is performed so that the steering angle enters the dead zone, so that the dead zone functions at any steering angle. It becomes. Therefore, even when the steering wheel is steered to a predetermined steering angle while traveling on a curved road, even if the steering angle of the steering wheel fluctuates within a minute angle range, that is, the dead band width range, the swivel mechanism is operated by the dead band function. The deflection control is suppressed, and fluctuations in the irradiation direction of the lamp are prevented.

  On the other hand, when the driver intentionally steers the steering wheel STW to change the traveling direction of the vehicle, the reference value and the dead zone width are changed when the steering angle comes out of the dead zone width. Since the output steering angle is changed, deflection control of the irradiation direction of the low beam lamp by AFS is executed. Further, since the deflection control by the AFS is performed and the dead zone width is changed following the steering angle, after the deflection control is performed, the variation in the irradiation direction due to the minute variation of the steering angle again occurs. Will be prevented.

  Therefore, the control of the dead zone in the first embodiment is not limited to when the vehicle is traveling straight as in Patent Document 1, and only when the vehicle is traveling straight and when the steering is switched back, as in Patent Document 2. Without being limited to preventing fluctuations in the lamp irradiation direction, it is possible to prevent fluctuations in the lamp irradiation direction when traveling at any steering angle. This prevents the driver from feeling uncomfortable.

  In the first embodiment, when the steering angle is turned back toward 0 degrees at the timing t5 in FIG. 4, the output steering angle is an angle corresponding to ½ of the dead zone width with respect to the steering angle actually detected. An error has occurred, but in the second embodiment, this error is eliminated. The configuration of the ECU 10 shown in FIG. 1 is substantially the same as that of the first embodiment, but here, a part of the function of the output steering angle setting unit 135 connected to the dead zone determination unit 131 is different. That is, referring to the flowchart of FIG. 5, the same steps as those in FIG. 3 are denoted by the same reference numerals, and when the dead zone determination unit 131 determines in step S <b> 102 that the steering angle is not in the dead zone, the first embodiment. After performing steps S104, S105, and S106 to set the dead zone in the same manner as described above, the reference value is output as the output steering angle in step S103. If it is determined that the steering angle is in the dead zone, in step S103A The output steering angle output from the output steering angle setting unit 135 is configured to perform a process of outputting the steering angle at the time when the steering angle enters the dead zone (hereinafter referred to as the initial steering angle) as the output steering angle. Therefore, according to the output steering angle setting unit 135, when the steering angle is in the dead zone width, the dead zone reference value has been used as the output steering angle until then. The initial steering angle at the time of determination is continuously output as the output steering angle.

  FIG. 6 is a timing chart of the second embodiment in the case of the same steering angle change as that of the first embodiment. At timing t11, the steering angle indicated by the thick broken line increases from 0 degrees to +15 degrees, and then the steering angle decreases in the low angle direction (0 When the angle is cut back by a small angle (degree direction), the dead zone reference value is set to +13 degrees as shown by the alternate long and short dash line, and therefore the dead zone width is set to +11 degrees to +15 degrees. After setting the dead zone, the steering angle fluctuates only within the range of +11 degrees to +15 degrees and does not leave the dead zone. Therefore, the output steering angle of the bold solid line that is output is the initial steering angle when the dead zone is first entered. A certain +15 degrees is specified, and the irradiation direction Lx of the lamp is held at a predetermined angle regardless of the change of the steering angle. After that, when the steering angle is steered from the dead zone in the low angle direction and deviated from the dead zone, the dead zone was changed in the same manner as in Example 1, and the steering angle was returned to 0 degree at timing t12. Sometimes, the steering angle is set to 0 degree, and the dead zone width is set to 0 degree to +4 degree. Thereafter, since the steering angle remains at 0 degrees and continuously enters the dead zone, thereafter, at the time t12 when the dead zone is entered, 0 degrees of the steering angle is set as the output steering angle. Thus, when the steering wheel is turned back to 0 degrees, the lamp irradiation direction Lx is controlled to be deflected to 0 degrees, and the irradiation direction Lx is fixed to +2 degrees as in the first embodiment. That is solved.

  Also in the second embodiment, the dead zone is changed so as to follow the detected steering angle, and the steering angle is controlled so as to enter the dead zone, so that the dead zone functions at any steering angle. Therefore, when the steering wheel STW is steered to a predetermined steering angle while traveling on a curved road, even if the steering angle fluctuates within a minute angle range, that is, the dead zone, the deflection control of the swivel mechanism is performed by the dead zone function. Is suppressed, and fluctuations in the irradiation direction of the lamp are prevented. In the second embodiment, when the steering angle is returned to the straight traveling direction, the lamp irradiation direction Lx is also directed to the straight traveling direction, so that the driver does not feel uncomfortable.

  In Examples 1 and 2, the dead zone is changed following the change in the steering angle. However, when the steering angle is changed from the low angle direction to the high angle direction and enters the dead zone, the dead zone is changed. However, since the dead zone is formed in the low angle region, the steering angle immediately deviates from the dead zone when the steering angle is changed to the high angle side. Accordingly, in the first embodiment, the reference value is changed and output. The steering angle is changed, and in the second embodiment, the output steering angle is immediately changed, and it may be difficult to obtain stability of the lamp irradiation direction. Further, in the second embodiment, when the steering angle is in the dead zone, the output steering angle is switched from the reference value until then to the initial steering angle when the dead zone is entered. As shown, the output steering angle may change abruptly, and the lamp irradiation change may change greatly. The third embodiment improves these points. In the dead zone processing unit 13 shown in FIG. 1, when the dead zone determining unit 131 determines that the steering angle has entered the dead zone, a difference value calculation is performed according to the situation. The reference value storage unit 133 is controlled while waiting for the calculation in the unit 136 or without performing the calculation, and the reference value stored in the reference value storage unit 133 can be changed.

  FIG. 7 is a flowchart of the third embodiment. The same steps as those in the flowchart of FIG. 3 are denoted by the same reference numerals, and when the dead zone determination unit 131 determines that the steering angle has entered the dead zone, the dead zone determination unit 131. Passes through the difference value calculation unit 136 and controls the reference value storage unit 133 to set the initial steering angle when entering the dead zone as a reference value, and at the same time, outputs the initial steering angle to the output steering angle setting unit 135. Output as a corner. That is, specifying the reference value to a specific value when the steering angle enters the dead zone is the same as in the first embodiment, but in the third embodiment, the initial steering angle when the steering angle enters the dead zone is the same. Is set. In other words, the initial steering angle when entering the dead zone is set as the reference value, and the set reference value is output as the output steering angle as in the first embodiment.

  Further, the third embodiment includes a flow for preventing the output steering angle from changing suddenly when the steering angle enters the dead zone. In other words, when the steering angle enters the dead zone in step S102, the dead zone determination unit 131 sets the reference value in the reference value storage unit 133, and the initial steering angle when the dead zone is entered, and is set at that time. The difference between the two and the reference value is taken (S107), it is determined whether or not the difference between the two is smaller than a predetermined value P (S108), and when the difference is smaller than P, the initial steering angle is immediately set to the reference value (S108). S108). When the difference between the two is equal to or greater than the predetermined value P, the reference value is updated so that the reference value approaches the steering angle by a value Q (Q <P) smaller than the predetermined value P (S110). Store in the reference value storage unit 133. Therefore, in step S103, the dead zone is set based on the updated reference value, and the updated reference value is output as the output steering angle. Similarly, in the next flow, the difference between the initial steering angle when the dead zone is entered in step S107 and the reference value updated last time and set in the reference value storage unit 133 is taken, and this is taken as a predetermined value P. When the difference is smaller than the predetermined value P, the reference value is updated to the steering angle (S109), and when the difference is equal to or larger than the predetermined value P, the reference value is further updated so as to approach the steering angle by the value Q (S110). Then, this is set as a reference value, and a dead zone is set based on this reference value, and at the same time, it is output as an output steering angle (S103). By repeating this, the difference between the initial steering angle and the reference value is finally within the predetermined value P. At this time, the reference value is updated to the initial steering angle and set, and the dead zone is set based on this reference value. And output as an output steering angle. As a result, the reference value and the output steering angle are gradually changed, but are equal to the initial steering angle when the dead zone is finally entered. Therefore, the change in the lamp irradiation direction accompanying the change in the output steering angle is also gentle. It becomes something.

  FIG. 8 is a timing chart of the third embodiment. The steering angle is out of the dead zone until the timing t21, the reference value is increased with the steering angle, and the dead zone is changed based on the reference value. When the steering angle enters the dead zone at timing t21, the dead zone determination unit 131 updates the reference value storage unit 133 with the initial steering angle at that time as a reference value. At the same time, the output steering angle is output from the output steering angle setting unit 135 based on the reference value. Therefore, the initial steering angle when entering the dead zone becomes the reference value to set the dead zone, and this reference value becomes the output steering angle. Here, since the steering angle is +15 degrees and is in the dead zone, this initial steering angle +15 degrees becomes the reference value, and thus, the range of +2 degrees to -2 degrees of the reference value, that is, the range of +13 degrees to +17 degrees And the output steering angle is +15 degrees. By setting the dead zone in this way, not only when the steering angle is +2 degrees in the low angle direction from the initial steering angle +15 degrees when entering the dead zone, but also when the steering angle is +2 degrees in the high angle direction. The steering angle does not deviate from the dead zone, and therefore the output steering angle is not changed. As a result, the irradiation direction of the lamp can be stabilized. Note that, at the timing t22, when the steering angle deviates in a lower angle direction than the dead zone, the dead zone is changed following this, as in the first embodiment. When the steering angle becomes 0 degree at timing t23 and the steering angle enters the dead zone again, the dead zone is set and the output steering angle is output in the same manner as at timing t21.

  In the third embodiment, when the steering angle enters the dead zone at the timing t21, as shown in the enlarged view of the region S2 in FIG. The difference between the steering angle +15 degrees and the reference value at that time +13 degrees is taken. Since the difference d1 = 2 degrees is equal to or greater than a predetermined value P (here, P = 1 degree), the reference value is smaller than the predetermined value P so that the reference value approaches the steering angle (Q = here). And the obtained +13.6 degrees is updated to the reference value storage unit 133 as a new reference value. Then, the dead zone is set based on the updated reference value, and the output steering angle is output to control the irradiation direction of the lamp. Here, the output steering angle is +13.6 degrees. Similarly, in the next flow, the difference between the initial steering angle +15 degrees when entering the dead zone and the reference value +13.6 degrees updated in the previous flow is taken. Since this difference d2 = 1.4 degrees is still larger than the predetermined value P = 1 degree, the reference value is further increased by +14.2 degrees, which is further increased by Q = 0.6 degrees from the previous +13.6 degrees. Similarly, a dead zone is set based on the reference value, and an output steering angle is output to control the irradiation direction of the lamp. Here, the output steering angle is +14.2 degrees. Further, the same processing is repeated, and then when the difference d3 = 0.8 degrees between the initial steering angle +15 degrees and the previously updated reference value + 14.2 degrees becomes smaller than the predetermined value P = 1 degree. The initial steering angle +15 degrees when entering the dead zone for the first time is updated as a reference value. As a result, a dead zone of +13 degrees to +17 degrees with +15 degrees as a reference value is set, and at the same time, the output steering angle becomes +15 degrees. That is, the output steering angle is increased stepwise as 13 degrees <13.6 degrees <14.2 degrees <15 degrees, and the lamp irradiation direction controlled based on this output steering angle is abrupt. Change is suppressed. The same applies to the region S3 in FIG. 8 where the steering angle is turned back to 0 degree.

  According to the third embodiment, the same operational effects as those of the first embodiment can be obtained. However, the initial steering angle when entering the dead zone is set as a reference value, and the lower side of the steering angle with respect to this reference value. Since the dead zone is set on both sides of the high angle side, the dead zone will function effectively even when the steering angle is changed to the high angle side after entering the dead zone, and the steering angle is in a very small angle range. That is, as long as it varies within the range of the dead zone width, the deflection control of the swivel mechanism is suppressed by the dead zone function, and fluctuations in the irradiation direction of the lamp are prevented. Further, when the steering angle enters the dead zone, the initial steering angle becomes the output steering angle, so that the output steering angle when the steering angle is switched back to 0 degrees is set to 0 degrees as in the second embodiment. Will also be possible. Furthermore, even when the steering angle enters the dead zone and the output steering angle changes greatly, the rapid change of the reference value is suppressed, so that the rapid change of the output steering angle can be suppressed, and the irradiation direction of the lamp Rapid changes can be prevented. Thereby, it becomes possible to improve the stability of control of the irradiation direction of the lamp.

  Here, in the first to third embodiments, the dead zone width stored in the dead zone width storage unit 134 is fixedly set to be a predetermined steering angle range centered on the reference value. As shown, the vehicle speed signal from the vehicle speed sensor 30 may be input to the dead band width storage unit 134 and the dead band width may be changed based on the vehicle speed. For example, the dead zone width may be reduced when the vehicle speed is high, and the dead zone width may be increased as the vehicle speed decreases. As a result, it is possible to more effectively prevent fluctuations in the lamp irradiation direction during low-speed running where the steering angle is relatively large.

  In the first to third embodiments, the dead zone setting unit 132 sets the dead zone width symmetrically in the ± direction, that is, in the left-right direction with the reference value as the median value. By increasing the dead band width in the direction of steering from left to right (in which the absolute value of the steering angle increases), and reducing the dead band width in the switch back direction, for example, at the time of switch back It is also possible to increase the responsiveness of the change in the dead zone width to the change in the steering angle to increase the response of the lamp irradiation direction to the change in the steering angle.

  The present invention is not limited to the AFS shown in the first to third embodiments, and can be similarly applied to any AFS that controls the deflection of the lamp irradiation direction following the change in the steering angle.

It is a block diagram which shows the whole structure of Example 1 of this invention. FIG. 3 is a longitudinal sectional view illustrating a configuration example of a right headlamp according to the first embodiment. 3 is a flowchart for explaining control of the first embodiment. FIG. 3 is a timing diagram for explaining control in the first embodiment. 6 is a flowchart for explaining control of Embodiment 2. FIG. 6 is a timing diagram for explaining the control of the second embodiment. 10 is a flowchart for explaining control in Embodiment 3; FIG. 10 is a timing diagram for explaining the control of the third embodiment. FIG. 8 is an enlarged view of a region S2 in the timing diagram of FIG.

Explanation of symbols

RHL, LHL Headlamps RLBL, LLBL Low beam headlamp SV Swivel mechanism Lx Lamp irradiation direction 10 ECU
DESCRIPTION OF SYMBOLS 11 Deflection angle calculation part 12 Swivel control part 13 Dead zone processing part 131 Dead zone determination part 132 Dead zone setting part 133 Reference value memory | storage part 134 Dead zone width memory | storage part 135 Output steering angle setting part 136 Difference value calculation part 20 Steering angle sensor 30 Vehicle speed sensor

Claims (7)

  In a lamp system including a deflection control unit that detects a steering angle of a vehicle and performs deflection control of the irradiation direction of the lamp based on the detected steering angle, the deflection control unit determines the irradiation direction of the lamp based on the steering angle. A deflection angle calculating means for calculating a deflection angle; and a dead zone processing means for setting a dead zone for the steering angle inputted to the deflection control means and changing the dead zone following the steering angle, and the dead zone. When the steering angle goes out of the dead zone, the processing means changes the dead zone by the amount of the steering angle so that the steering angle falls within the dead zone, and uses the dead zone reference value as the output steering angle for calculating the deflection angle. A lamp system that outputs to a deflection control means.   In a lamp system including a deflection control unit that detects a steering angle of a vehicle and performs deflection control of the irradiation direction of the lamp based on the detected steering angle, the deflection control unit determines the irradiation direction of the lamp based on the steering angle. A deflection angle calculating means for calculating a deflection angle; and a dead zone processing means for setting a dead zone for the steering angle inputted to the deflection control means and changing the dead zone following the steering angle, and the dead zone. The processing means changes the dead zone by the amount of the steering angle so that the steering angle enters the dead zone when the steering angle goes out of the dead zone, and outputs the initial steering angle when the dead zone enters the output steering for the deflection angle calculation. A lamp system that outputs the angle to the deflection control means as an angle. (New claim)
In a lamp system including a deflection control unit that detects a steering angle of a vehicle and performs deflection control of the irradiation direction of the lamp based on the detected steering angle, the deflection control unit determines the irradiation direction of the lamp based on the steering angle. A deflection angle calculating means for calculating a deflection angle; and a dead zone processing means for setting a dead zone for the steering angle inputted to the deflection control means and changing the dead zone following the steering angle, and the dead zone. When the steering angle goes out of the dead zone, the processing means changes the dead zone so that the steering angle enters the dead zone, and when the steering angle enters the dead zone, The initial steering angle is set to a dead zone reference value, and the reference value is output to the deflection control means as an output steering angle for calculating a deflection angle.   A lamp deflection control method for detecting a steering angle of a vehicle, calculating a deflection angle of a lamp irradiation direction based on the detected steering angle, and controlling the deflection direction of the lamp irradiation direction to the calculated deflection angle. A reference value is set based on the angle, the dead zone is changed so that the steering angle enters the dead zone based on the reference value, and the reference value is set as an output steering angle, and the deflection angle is set at the output steering angle. A lamp deflection control method characterized by performing the following calculation.   A lamp deflection control method for detecting a steering angle of a vehicle, calculating a deflection angle of a lamp irradiation direction based on the detected steering angle, and controlling the deflection direction of the lamp irradiation direction to the calculated deflection angle. A reference value is set based on the angle, the dead zone is changed so that the steering angle enters the dead zone based on the reference value, the initial steering angle when entering the dead zone is set as the output steering angle, and this output A lamp deflection control method, wherein the deflection angle is calculated by a steering angle.   A lamp deflection control method for detecting a steering angle of a vehicle, calculating a deflection angle of a lamp irradiation direction based on the detected steering angle, and controlling the deflection direction of the lamp irradiation direction to the calculated deflection angle. A reference value is set based on the angle, the dead zone is changed so that the steering angle enters the dead zone based on the reference value, and the initial steering angle when the steering angle enters the dead zone is set to the reference value, A lamp deflection control method, wherein the reference value is set as an output steering angle, and the deflection angle is calculated based on the output steering angle. The step of taking the difference between the initial steering angle when entering the dead zone and the reference value immediately before entering the dead zone and updating the reference value by a value smaller than the predetermined value is repeated until the difference falls within a predetermined value. The lamp deflection control system according to claim 6.

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