JP2015016733A - Lighting control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a driver from being bothered when light distribution control for forming a partial non-lighting region in a lighting region is performed.SOLUTION: A light distribution control part forms a non-lighting region in a part of a lighting region formed by a lamp fitting which lights the front part of a vehicle. An illuminance control part controls the lamp fitting so that the illuminance of at least the part of the lighting region lowers when the luminosity of the front side of the vehicle, which is detected by a sensor, is lower than a first threshold value.

Description

  The present invention relates to an illumination control system that controls a lamp that illuminates the front of a vehicle.

  This type of system is based on a headlamp capable of irradiating a low beam and a high beam, a non-illuminated area forming unit that forms a non-illuminated area by shielding a part of the high beam, and an image in front of the vehicle captured by the camera. There is known a vehicle equipped with a detection unit that detects a vehicle (a preceding vehicle or an oncoming vehicle) traveling ahead (see, for example, Patent Document 1). By controlling the non-illumination region forming unit so that the detected front vehicle is positioned within the non-illumination region, glare applied to the front vehicle is suppressed. On the other hand, high beam irradiation around the non-illuminated area is maintained, so that the visibility of the surroundings is ensured.

JP 2010-140661 A

  The light distribution control that forms a partial non-illumination area in the illumination area as described above may make the driver feel bothersome depending on the traveling environment of the vehicle. For example, when traveling on a night road without any streetlight, the illuminance difference (contrast) between the non-illuminated area and the illuminated area increases. For this reason, changes in the position and size of the non-illuminated area are relatively easily recognized, which may lead to annoyance.

  Therefore, an object of the present invention is to provide a technique that does not bother the driver when performing light distribution control for forming a partial non-illumination region in the illumination region.

In order to achieve the above object, one aspect of the present invention can be a lighting control system,
A lamp that illuminates the front of the vehicle;
A sensor for detecting the brightness in front of the vehicle;
A light distribution control unit that forms a non-illumination region in a part of the illumination region formed by the lamp; and
An illuminance control unit configured to control the lamp so that at least a part of the illuminance of the illumination area decreases when the brightness detected by the sensor is lower than a first threshold value.

  According to such a configuration, for example, when driving on a night road without a streetlight, when the front of the vehicle is dark to some extent, the illuminance in the illumination area is reduced, so that the illuminance difference (contrast) from the non-illumination area Becomes smaller. This makes it difficult for the driver to recognize changes in the position and size of the non-illuminated area. Therefore, inconvenience given to the driver in performing light distribution control for forming a partial non-illumination region in the illumination region can be suppressed.

  The illuminance control unit may be configured to control the lamp so that the illuminance of at least a part of the illumination area increases when the brightness detected by the sensor exceeds a second threshold.

  For example, when traveling in a place with many street lamps, the illuminance difference between the non-illuminated area and the illuminated area is small because the front of the vehicle is bright to some extent. For this reason, changes in the position and size of the non-illuminated region are not easily recognized, and the driver may not easily feel the benefits of light distribution control that forms a partial non-illuminated region in the illuminated region. Alternatively, there is a case where the user feels uneasy about whether the light distribution control is normally executed. According to the above configuration, when the front of the vehicle is bright to some extent, the illuminance difference (contrast) with the non-illuminated area is increased by increasing the illuminance of the illuminated area. This makes it easier for the driver to recognize changes in the position and size of the non-illuminated area. Therefore, it is possible to give the driver a sense of realness and a sense of security that the light distribution control is normally executed.

  The said illumination intensity control part is good also as a structure which changes the illumination intensity of the part adjacent to the said non-illumination area | region in the said illumination area at least.

  According to such a configuration, it is possible to effectively adjust the contrast between the non-illuminated area and the illuminated area felt by the driver with a minimum control. In particular, this is suitable for controlling the position and size of the non-illuminated region by using an array light source in which a plurality of semiconductor light-emitting elements are arranged and controlling turning on and off of the individual semiconductor light-emitting elements.

It is a figure showing typically the control system concerning one embodiment of the present invention. It is a longitudinal cross-sectional view which shows typically the internal structure of the headlamp which comprises a control system. It is a front view which shows the structure of the shade mechanism mounted in a headlamp. It is a figure which shows typically the example of the light distribution pattern formed with a control system. It is a flowchart which shows the example of the illumination intensity control performed by a control system.

  Exemplary embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In each drawing used in the following description, the scale is appropriately changed to make each member a recognizable size. Further, “right” and “left” used in the following description indicate the left and right directions viewed from the driver's seat.

  FIG. 1 schematically shows the overall configuration of a vehicle 2 equipped with a control system 1 according to an embodiment of the present invention. The control system 1 includes an integrated control unit 3, a right headlamp 5R, a left headlamp 5L, a wheel speed sensor 6, a steering angle sensor 7, a camera 8, and a brightness sensor 9.

  The integrated control unit 3 includes a CPU that executes various arithmetic processes, a ROM that stores various control programs, a RAM that is used as a work area for data storage and program execution, and executes various controls in the vehicle 2. .

  The wheel speed sensor 6 is provided corresponding to each of the four wheels of the left and right front wheels and the rear wheel assembled to the vehicle 2. Each of the wheel speed sensors 6 is communicably connected to the integrated control unit 3 and outputs a signal corresponding to the rotational speed of the wheel to the integrated control unit 3. The integrated control unit 3 calculates the speed of the vehicle 2 using the signal input from the wheel speed sensor 6.

  The steering angle sensor 7 is provided on the steering wheel and is communicably connected to the integrated control unit 3. The steering angle sensor 7 outputs a steering angle pulse signal corresponding to the steering rotation angle of the steering wheel by the driver to the integrated control unit 3. The integrated control unit 3 calculates the traveling direction of the vehicle 2 using a signal input from the steering angle sensor 7.

  The camera 8 includes an image sensor such as a CCD (Charged Coupled Device) sensor or a CMOS (Complementary Metal Oxide Semiconductor) sensor. For example, the camera 8 is arranged on the rear surface of the rearview mirror, faces forward, and captures an image in front of the vehicle. The camera 8 is communicably connected to the integrated control unit 3 and transmits the acquired image data to the integrated control unit 3.

  The brightness sensor 9 is disposed, for example, in the front portion of the vehicle 2 and detects at least the brightness in front of the vehicle 2. The brightness sensor 9 is communicably connected to the integrated control unit 3 and transmits a signal corresponding to the detected brightness to the integrated control unit 3.

  The right headlamp 5R is arranged on the right side of the front part of the vehicle 2, and the left headlamp 5L is arranged on the left side of the front part of the vehicle 2. In the following description, the right headlamp 5R and the left headlamp 5L are collectively referred to as “headlamp 5” as necessary. The headlamp 5 is communicably connected to the integrated control unit 3.

  FIG. 2 is a schematic cross-sectional view showing the internal structure of the right headlamp 5R. Since the structure of the left headlamp 5L is the same as that of the right headlamp 5R, illustration and detailed description thereof are omitted.

  The headlamp 5 is a lamp for illuminating the front of the vehicle 2. The headlamp 5 includes a housing 212 and a translucent cover 214. The translucent cover 214 is attached to the housing 212 and defines the lamp chamber 216. A lamp unit 10 that irradiates light in front of the vehicle 2 is housed in the lamp chamber 216.

  The lamp unit 10 includes a base 11, a high beam light source 12, a low beam light source 13, a high beam reflector 14, a low beam reflector 15, a projection lens 16, a shade mechanism 20, and a swivel mechanism 30.

  The high beam light source 12 is attached to the base 11 with its light emitting surface facing downward, and light from the high beam light source 12 is reflected forward by a high beam reflector 14 attached to the base 11 so as to face the high beam light source 12. The low beam light source 13 is attached to the base 11 with the light emitting surface facing upward.

  Light from the low beam light source 13 is reflected forward by a low beam reflector 15 attached to the base 11 so as to face the low beam light source 13. The reflected light from the high beam reflector 14 and the low beam reflector 15 is projected forward along the optical axis Ax of the lamp through the projection lens 16 made of a convex lens.

  In the present embodiment, the high beam light source 12 and the low beam light source 13 are constituted by light emitting diodes (LEDs). Further, the high beam reflector 14 and the low beam reflector 15 have reflection surfaces based on an elliptical spherical surface.

  In the vicinity of the rear focal point F of the projection lens 16, a shade mechanism 20 that can block part of the light from the high beam light source 12 and the low beam light source 13 is provided. As the shade mechanism 20, for example, a mechanism shown in FIG. 3 can be employed.

  The shade mechanism 20 includes a frame 21, a pair of gear units 22 a and 22 b, a pair of light shielding members 23 a and 23 b, and a fixed light shielding plate 24. The pair of gear units 22a and 22b is connected to a drive source such as a motor (not shown). The pair of light shielding members 23a and 23b mesh with the gear units 22a and 22b, respectively, and are rotatable with respect to the frame 21. The fixed light shielding plate 24 is provided above the frame 21.

  A slit 25 is formed between the frame 21 and the fixed light shielding plate 24. Light emitted from the high beam light source 12 and the low beam light source 13 passes through the slit 25 and enters the projection lens 16. The light shielding portions of the light shielding members 23a and 23b are rotated so as to enter the slit 25, and a part of light from the high beam light source 12 and the low beam light source 13 can be shielded.

  As shown in FIG. 2, a swivel mechanism 30 that rotates the optical axis of the lamp unit 10 to the left and right is provided on the lower surface of the lamp unit 10. The swivel mechanism 30 includes a swivel actuator 31, and a rotation shaft thereof is fixed to a rotary bearing 31 a provided at a lower portion of the base 11 of the lamp unit 10. The swivel actuator 31 is controlled by the integrated controller 3 and can move the illumination area in the left-right direction by turning the optical axis Ax of the lamp unit 10 to the left and right.

  Next, a light distribution pattern formed by the right headlamp 5R and the left headlamp 5L having the above-described configuration will be described with reference to FIG.

  The light emitted from the low beam light source 13 illuminates the lower side of the horizontal cut-off line CL extending in the left-right direction near the horizontal line HH. The light emitted from the high beam light source 12 illuminates a region including the upper side of the horizontal cut-off line CL. The integrated control unit 3 controls how the light emitted from the high beam light source 12 and the low beam light source 13 is blocked by displacing the light shielding members 23 a and 23 b of the shade mechanism 20.

  FIG. 4A schematically shows a partial right high beam pattern RPH formed by the right headlamp 5R. A part of the light emitted from the high beam light source 12 of the right headlamp 5R is shielded, so that the right non-illumination region RS is formed in the high beam illumination region. A boundary in the left-right direction between the right non-illumination region RS and the illumination region is a right vertical cut-off line RC.

  FIG. 4B schematically shows a partial left high beam pattern LPH formed by the left headlamp 5L. A part of the light emitted from the high beam light source 12 of the left headlamp 5L is shielded to form a left non-illuminated area LS in the high beam illuminated area. The boundary in the left-right direction between the left non-illuminated area LS and the illuminated area is a left vertical cut-off line LC.

  FIG. 4C shows a partial high beam pattern PH obtained by superimposing the partial right high beam pattern RPH and the partial left high beam pattern LPH. A portion where the right non-illumination region RS and the left non-illumination region LS are overlapped becomes a non-illumination region S.

  The non-illumination area S is formed to suppress glare of the preceding vehicle detected in the high beam illumination area. The “front vehicle” includes both a preceding vehicle traveling in front of the own lane and an oncoming vehicle traveling in the oncoming lane. In FIG. 4C, there is a front vehicle F1 on the own lane, and the positions of the right vertical cut-off line RC and the left vertical cut-off line LC are determined so that the front vehicle F1 falls within the non-illuminated region S. It has been.

  Specifically, the integrated control unit 3 detects the presence or absence of a forward vehicle or a pedestrian based on the front image of the vehicle 2 acquired by the camera 8, and determines whether or not it is necessary to form a partial high beam pattern PH. to decide. When it is determined that the partial high beam pattern PH needs to be formed, the position of the object detected through the camera 8, the speed of the vehicle 2 detected by the wheel speed sensor 6, and the progress of the vehicle 2 detected by the steering angle sensor 7. Based on the direction, the position and range of the non-illuminated region S to be formed are determined. Based on the determined position and range of the non-illumination region S, the integrated control unit 3 controls the shade mechanism 20 and the swivel mechanism 30 in each of the right headlamp 5R and the left headlamp 5L.

  The integrated control unit 3 can control the illuminance of the illumination area in the partial high beam pattern PH by adjusting the light intensity of at least one of the high beam light source 12 and the low beam light source 13 included in the headlamp 5. The light intensity is adjusted by increasing or decreasing the power supplied to each light source.

  FIG. 5 is a flowchart showing the illuminance control process executed by the integrated control unit 3. The integrated control unit 3 determines whether the brightness detected by the brightness sensor 9 is below the first threshold (step S1). When it is determined that the detected brightness is lower than the first threshold (Yes in step S1), the integrated control unit 3 causes the headlamp 5 to reduce the illuminance of the illumination area in the partial high beam pattern PH. Is controlled (step S2).

  On the other hand, when it is determined that the detected brightness is equal to or higher than the first threshold (No in step S1), the integrated control unit 3 determines whether the brightness detected by the brightness sensor 9 exceeds the second threshold. Determine (step S3). When it is determined that the detected brightness exceeds the second threshold (Yes in step S3), the integrated control unit 3 causes the headlamp 5 to increase the illuminance of the illumination area in the partial high beam pattern PH. Is controlled (step S4).

  When it is determined that the detected brightness is greater than or equal to the first threshold and less than or equal to the second threshold (No in step S3), the integrated control unit 3 maintains the illumination intensity of the illumination area in the partial high beam pattern PH (step) S5).

  As described above, in the control system 1 (an example of a lighting control system) according to an embodiment of the present invention, the headlamp 5 (an example of a lamp) illuminates the front of the vehicle 2, and the brightness sensor 9 is The brightness in front of the vehicle 2 is detected. The integrated control unit 3 (an example of a light distribution control unit) forms the non-illumination region S in a part of the illumination region formed by the headlamp 5. The integrated control unit 3 (an example of an illuminance control unit) controls the headlamp 5 so that the illuminance of the illumination area decreases when the brightness detected by the brightness sensor 9 is lower than the first threshold.

  According to such a configuration, for example, when driving on a night road without a streetlight, when the front of the vehicle 2 is dark to some extent, the illuminance of the illumination area in the partial high beam pattern PH is reduced, so that the non-illumination area The illuminance difference (contrast) with S is reduced. This makes it difficult for the driver to recognize changes in the position and size of the non-illuminated region S. Therefore, it is possible to suppress the troublesomeness given to the driver when performing the light distribution control for forming the partial high beam pattern PH.

  In the above embodiment, the integrated control unit 3 (an example of the illuminance control unit) uses the headlamp so that the illuminance of the illumination region increases when the brightness detected by the brightness sensor 9 exceeds the second threshold. 5 is controlled.

  For example, when traveling in a place with many street lamps, the front of the vehicle 2 is bright to some extent, so that the difference in illuminance between the non-illuminated area S and the illuminated area becomes small. Therefore, changes in the position and size of the non-illuminated region S are difficult to recognize, and the driver may not feel the benefits of light distribution control using the partial high beam pattern PH. Alternatively, there is a case where the user feels uneasy about whether the light distribution control is normally executed. According to the above configuration, when the front of the vehicle 2 is bright to some extent, the illuminance difference (contrast) with the non-illuminated area S is increased by increasing the illuminance of the illumination area in the partial high beam pattern PH. This makes it easier for the driver to recognize changes in the position and size of the non-illuminated area S. Therefore, it is possible to give the driver a sense of realism and a sense of security that the light distribution control for forming the partial high beam pattern PH is normally executed.

  The above embodiment is for facilitating understanding of the present invention, and does not limit the present invention. The present invention can be modified and improved without departing from the spirit of the present invention, and it is obvious that the present invention includes equivalents thereof.

  In the above embodiment, the illuminance value of the illumination area in the partial high beam pattern PH is maintained, and three illuminance values can be taken. However, the first threshold value and the second threshold value may be the same, and two illuminance values may be switched. On the other hand, according to the brightness which the brightness sensor 9 detects, it is good also as a structure by which switching is made between more illuminance values. The illuminance value may be raised or lowered stepwise or continuously. The relationship between the detected brightness and the controlled illuminance may be linear or non-linear.

  The high beam light source 12 and the low beam light source 13 of the headlamp 5 are not limited to LEDs. A semiconductor light emitting element such as a laser diode or an organic EL element may be used, and a bulb light source such as a halogen lamp or a high intensity discharge (HID) lamp may be used. Further, the high beam light source 12 and the low beam light source 13 are not necessarily arranged in the same lamp unit.

  At least the high beam light source 12 can be an array light source in which a plurality of semiconductor light emitting elements are arranged. In this case, an illuminable region is formed by a plurality of partial regions corresponding to individual semiconductor light emitting elements, and an illumination region and a non-illuminated region are formed in the illuminable region by controlling turning on and off of the individual semiconductor light emitting elements. Is done. The present invention can also be applied to so-called electronic swivel control in which the array light source is used and the semiconductor light emitting element is turned on and off so that the detected preceding vehicle is included in the non-illuminated region.

  In this case, if the illuminance of at least the area adjacent to the non-illuminated area S (area AR shown by a broken line in FIG. 4C) is changed, the contrast between the non-illuminated area S and the illuminated area felt by the driver is effective. Can be adjusted. Specifically, the adjustment is performed by increasing or decreasing the power supplied to the semiconductor light emitting element associated with the area AR in the array light source. Therefore, effective illuminance adjustment can be performed with minimum control.

  The means for detecting the vehicle ahead is not limited to the camera 8, and a radar sensor or the like may be used. Moreover, it is good also as a structure which performs the detection of a forward vehicle, and acquisition of the information which concerns on a driving environment using vehicle-to-vehicle communication or road-to-vehicle communication.

  At least a part of the functions as the light distribution control unit and the illuminance control unit realized by the integrated control unit 3 may be shared by a lamp control module (not shown) disposed in the headlamp 5.

  1: control system, 2: vehicle, 3: integrated control unit, 5: headlight, 9: brightness sensor, PH: partial high beam pattern, S: non-illuminated area

Claims (3)

A lamp that illuminates the front of the vehicle;
A sensor for detecting the brightness in front of the vehicle;
A light distribution control unit that forms a non-illumination region in a part of the illumination region formed by the lamp; and
An illumination control system comprising: an illuminance control unit that controls the lamp so that the illuminance of at least a part of the illumination area decreases when the brightness detected by the sensor falls below a first threshold.   The said illumination intensity control part controls the said lamp so that the illumination intensity of the at least one part of the said illumination area rises, when the said brightness detected by the said sensor exceeds a 2nd threshold value. Lighting control system.   The illumination control system according to claim 1, wherein the illuminance control unit changes the illuminance of at least a portion of the illumination area adjacent to the non-illumination area.