Patent Application
20190359120
This application claims the priority benefit under 35 U.S.C. §119 of Japanese Patent Application No. 2018-099038 filed on May 23, 2018, which is hereby incorporated in its entirety by reference.
The present invention relates to vehicle lamp controllers for controlling vehicle lamps incorporated into an own vehicle to control light distribution angles of the vehicle lamps in accordance with a travelling direction of the own vehicle, and relates to method for controlling the vehicle lamps and to vehicle lamp systems including the vehicle lamp controllers along with the vehicle lamps.
Vehicle lamp controllers, which control light distribution angles of vehicle lamps in accordance with a travelling direction of an own vehicle, are well known. For example, a conventional vehicle cornering lamp, which may vary a light-irradiating direction of lamps when an own vehicle travels on a curved roadway, is disclosed in Patent Document No. 1 (Japanese Patent No. 2,633,169). The conventional vehicle cornering lamp discloses: an angle rate detection means detecting an angle rate of the own vehicle; a vehicle speed detection means detecting a vehicle speed of the own vehicle; a target location calculation means calculating a target location of the lamps based on the angle rate and the vehicle speed; and a light-emitting control means controlling a light-emitting angle of the lamps in accordance with the target location of the lamps.
Hence, the vehicle cornering lamp may vary the light-emitting angle, of lamps along the curved roadway on which the own vehicle travels. A conventional light distribution controller of vehicle headlights, which may vary a light-emitting direction of headlights when a own vehicle travels on a curved roadway, is disclosed in Patent Document No. 2 (Japanese Patent No. 3,690,099).
The light distribution controller discloses: an imaging equipment 50 detecting white lines shown on a driving lane of an own vehicle; a driving lane calculation means 53 calculating a center line of the driving lane on which the own vehicle should travel in accordance with said detected white lines; a vehicle speed sensor 51 detecting a vehicle speed of the own vehicle; a steering angle sensor 52 detecting a steeling angle when the own vehicle travels; a target light-emitting location means 54 calculating a target light-emitting direction of a vehicle headlight 56 incorporated into the own vehicle in accordance with the vehicle speed and the steering angle in addition to the white lines of the driving lane; and a headlight driving means 55 controlling the vehicle headlight 56 in accordance with the target light-emitting direction calculated by the target light-emitting location means 54.
In addition, the conventional light distribution controller also discloses a lateral discrepancy sensor 57, which may detect a lateral discrepancy of the own vehicle with reference with the center line of the driving lane for correcting the target light-emitting direction.
However, while the light distribution controller described above works, the light distribution controller sometimes may provide drivers of the own vehicles with a feeling of strangeness. For example, when a shift of light distribution patterns generated by the light distribution controller is too short, the light distribution controller may operate very often in accordance with a small alteration of the steering angle and the like even when the own vehicles travel on a straight road with a good view. In addition, when the own vehicles travel on a blind curved road and when the shift of the light distribution patterns generated by the light distribution controller is too long, the light distribution controller may cause any trouble such that may not provide the drivers with preferable light distribution patters along the curved road.
The above-referenced Patent Documents and additional Documents are listed below and are hereby incorporated with their English abstracts and specifications in their entireties.
The present invention has been devised to consider the above and other problems, characteristics and features. Exemplary embodiments of the present invention can include providing the drivers with the preferable light distribution patters while avoiding the troubles such as described above.
According to one of aspects of the presently invention, an exemplary vehicle lamp controller for controlling a light-irradiating direction of a lamp unit in accordance with a traveling direction of an own vehicle incorporating the lamp unit and for providing the lamp unit with a driving signal so as to direct the light-irradiating direction of the lamp unit from an initial light distribution angle toward the traveling direction of the own vehicle when a traveling angle of the own vehicle is larger than thresholds, the vehicle lamp controller comprising a first threshold set up as one of the thresholds when a traveling road is a curved road, and a second threshold set up as another of the threshold when the traveling road is a straight road, wherein the second threshold is larger than the first threshold.
According to another of the aspects of the presently invention, another exemplary vehicle lamp controller for controlling a light-irradiating direction of a lamp unit in accordance with a traveling direction of an own vehicle incorporating the lamp unit, the vehicle lamp controller comprising: a traveling angle-sensing part detecting a traveling angle of the own vehicle; a setup part detecting whether a traveling road of the own vehicle is a straight road or a curved road, variably setting up thresholds, setting up a first threshold as one of the thresholds when the traveling road is the curved road, and setting up a second threshold as another of the thresholds when the traveling road is the straight road; a lighting control part outputting a driving signal to the lamp unit so as to direct the light-irradiating direction of the lamp unit from an initial light distribution angle toward the traveling direction of the own vehicle when the traveling angle detected by the traveling angle-sensing part is larger than the first threshold or the second threshold; and wherein the second threshold is set up at a larger value than the first threshold.
According to one of other aspects of the presently invention, an exemplary method for controlling a light-irradiating direction of a lamp unit in accordance with a traveling direction of an own vehicle incorporating the lamp unit, wherein the method is to output a driving signal to the lamp unit so as to direct the light-irradiating direction of the lamp unit from an initial light distribution angle toward the traveling direction of the own vehicle when the traveling angle is larger than a predetermined threshold, the control method for the lamp unit comprising a first threshold employed when the own vehicle travels on a curved road and a second threshold employed when the own vehicle travels on a straight road, wherein the second threshold is larger than the first threshold.
According to another of the other aspects of the presently invention, an exemplary vehicle lamp system according to any one of the above-described aspects, further comprising the lamp unit controlled by the vehicle lamp controller.
According to the above-described aspects, when the traveling road is the straight road, preferable light distribution angles can be set up in the traveling direction of the own vehicle determined with reference to the second threshold, which is set up at a relatively large threshold, and when the traveling road is also the curved road, the preferable light distribution angles can be set up in the traveling direction of the own vehicle determined with reference to the first threshold, which is set up at a relatively small threshold. Additionally, when it is difficult to determine whether the traveling road is the straight road or not such as an intersection, the second threshold can be changed so as to maintain the preferable light distribution patterns even when the traveling road varies from the straight road to the curved road. Thus, the present invention can provide preferable light distribution patterns for drivers of the own vehicle and other vehicles moving in front of the own vehicle.
These and other characteristics and features of the present invention will become clear from the following description with reference to the accompanying drawings, wherein:
The present invention will now be described in detail with reference to
The vehicle lamp system 1 can enable each of the right and left lamp units 15R, 15L to form preferable light distribution patterns in a traveling direction of an own vehicle incorporating the vehicle lamp system 1 by controlling a light-irradiating direction of the right and left lamp units 15R, 15L. The vehicle lamp controller 2 can include: an imaging unit 10 detecting road conditions as image data; a traveling angle-sensing part 3 detecting a traveling angle of the own vehicle; an interface controller 14 inputting the image data from the imaging unit 10, inputting the traveling angle from the traveling angle-sensing part 3 and outputting a lamp driving signal; and the right lamp unit 15R and the left lamp unit 15L inputting the lamp driving signal from the interface controller 14 and proving various light distribution patterns in accordance with the lamp driving signal.
In this case, the traveling angle-sensing part 3 can include a steering angle sensor 13, which detects a steering angle of a steering wheel of the own vehicle as the traveling angle of the traveling angle-sensing part 3,and outputs the steering angle to the interface controller 14. The imaging unit 10 can include a camera 11 and an image processor 12, and the camera can be attached to a predetermined position (e.g., an upside of a front windshield) of the own vehicle so as to photograph things in the traveling direction of the own vehicle. The image processor 12 can detect oncoming vehicles, white lines, yellow lines, guardrails, curbstones and the like by manipulating an image processing algorithm such as feature extractions with respect to the things photographed by the camera 11.
The steering 13 can detect the steering angle of the steering wheel of the own vehicle. The steering angle can be a plus angle such as one degree,for example, when the steering wheel turns in a clockwise direction, and when the steering wheel turns in a counterclockwise direction, the steering angle can detected as a minus angle such as minus two degrees, etc. The interface controller 14 can control operations of the vehicle lamp system 1 such as the right and left lamp units 15R, 15L, etc. The interface control 14 can employ a computer system including central processing unit (CPU), a read only memory (ROM) and a random access memory (RAM). The interface controller 14 can control the operations of the vehicle lamp system 1 by executing a computer software program for the computer system.
The interface control 14 can include a setup part 18 including a road condition judgement part 20 and a threshold setup part 21. The road condition judgement 20 can detect whether a traveling road of the own vehicle is a substantially straight or a curved road, and also can detect whether the oncoming vehicle approaches toward the own vehicle on an oncoming lane, which is located adjacent the traveling road. The threshold setup part 21 can set up steering angle thresholds for varying the lamp driving signal, which is output to the right and left lamp units 15R, 15L, to change the light distribution patterns in accordance with detections whether the traveling road of the own vehicle is the substantially straight or the curved road.
In addition, the interface control 4 can also include a lighting control part 19 including a light distribution angle setup part 22 and a lamp unit control part 23. The light distribution angle setup part 22 can output a light distribution angle in accordance with the detections whether the traveling road is the substantially straight or the curved road, and the lamp unit control part 23 can output the lamp driving signal to the right and left lamp units 15R, 15L.
The road condition judgement part 20 can detect whether the traveling road of the own vehicle is the substantially straight or the curved road in accordance with a shape of the white lines and the like, which is detected by the image processor 12 as described above. The threshold setup part 21 can adapt the steering angle thresholds, which are referred when the light distribution angle setup part 22 sets up the light distribution angle, in accordance with detecting results output from the road condition judgement part 20.
Specifically, the threshold setup part 21 can set up a first variable threshold as one of the steering angle thresholds when the traveling road is the substantially straight, and also can set up a second variable threshold as another of the steering angle thresholds when the traveling road is the curved road. In this case, the second variable threshold can be set up at a larger angle than the first variable threshold. Each of the first threshold and the second threshold can be set up at an appropriate angle based on evaluation results of a driving test, a computer simulation, etc. In this exemplary embodiment, the first initial threshold is set up at plus 8 degrees and minus 8 degrees (±8°), and the second initial threshold is set up at plus 18 degrees and minus 12 degrees (±12°).
The light distribution angle setup part 22 cannot vary the light distribution angle with maintenance of an initial light distribution angle when the steering angle of the own vehicle, which is detected by the steering angle sensor 13, is within the first threshold (±8°) when the traveling road is the curved road, a within the second threshold (±12°) when the traveling road of the own vehicle is the straight road. However, when the traveling road is beyond the first threshold (±8°) when the traveling road is the curved road, or the traveling road is beyond the second threshold (±12°) when the traveling road is the straight road, the light distribution angle setup part 22 can vary the light distribution angle from the initial light distribution angle so that the right and left lamp units 15R, 15L shift the light distribution pattern in the traveling direction of the own vehicle. Thereby, the vehicle lamp system 1 can provide the driver of the own vehicle with the preferable light distribution patterns for a safe driving.
The lamp unit control part 3 can produce the lamp driving signal to control each of the right and left lamp units 15R, 15L in accordance with the light distribution angle set up by the light distribution angle setup part 22, and can output the lamp driving signal to each of the right and left lamp units 15R, 15L. Therefore, a pair of the right and left lamp units 15R, 15L can form the light distribution pattern along the traveling road in the traveling direction of the own vehicle.
The right lamp unit 15R can include a right lamp 30R and a right lamp driver 31R in order for the right lamp 30R to form the preferable light distribution patterns, and can be attached to a right front of the own vehicle. Similarly, the left lamp unit 15L can also include a left lamp 30L and a left lamp driver 31L in order for the right lamp 30L to form the preferable light distribution patterns, and can be attached to a left front of the own vehicle.
Each of the right and left lamps 30R, 30L can form the preferable light distribution patterns, and each of the right and left lamp driver 31R, 31L can drive a respective one of the right and left lamps 30R, 30L to form the preferable light distribution patterns by rotating the respective one. Additionally, each of the right and left lamp drivers 31R, 31L can also drive a respective one of the right and left lamps 30R, 30L by using a micro mirror. A vehicle headlight system rotating a lamp is disclosed in Patent Document No. 3 (U.S. Pat. No. 9,849,827), and a vehicle headlight using the micro mirror is disclosed in Patent Document No. 4 (U.S. Pat. No. 9,606,351), which are owned by Applicant of this invention. Details of the above-described methods will be abbreviated here.
Next, an exemplary detecting method whether the traveling road of the own vehicle is the straight road will now be described with reference
In this case, the road condition judgement part 20 can detect whether the traveling road is the straight road by using at least one of the first line 100, the second line 101 and the center white line 102. For example, the road condition judgement part 20 can detect that the traveling road is the straight road when a curvature radius of the first 100 calculated is smaller than 1000 meters, and also can detect that the traveling road is the curved road when the curvature radius of the first white line 100 calculated is larger than 1000 meters. Additionally, the image processor 12 can also detect straight lines of the white lines, guardrails, curbstones and the like by using Hough-conversion method, etc.
The above-described initial light distribution angle 30IA can be set up so that the optical axis A is located in the substantially parallel direction with the y-axis, and therefore can correspond substantially to the optical axis A as shown in
The light distribution angle can maintain zero degree of the initial light distribution angle 30IA when the steering angle is smaller than 8 degrees, because the first threshold 3FT is set up at 8 degrees. When the steering angle exceeds 8 degrees of the first threshold 3FT, the light distribution angle can gradually increase from zero degree of the initial light distribution angle 30IA in proportion to the steering angle. A dotted line shown in
When the second threshold 3ST is used, the light distribution angle can gradually increase from zero degree of the initial light distribution angle 30IA in proportion to the steering angle, instead of using the relations between the steering angle and the light distribution angle shown by the solid line after the steering angle exceeds 12 degrees of the second threshold 3ST. Thereby, the vehicle lamp system 1 can prevent the drivers of the own vehicle from being bothered by the feeling of strangeness such that exponentially change the light distribution angle once the steering angle exceeds the second threshold 3ST. An increase rate of the light distribution angle when the second threshold 3ST is used (the dotted line) can become larger than that when the first threshold 3FT is used (the solid line).
When the steering angle exceeds approximately 16 degrees, which is a point where the solid line and the dotted line intersect, the light distribution angle can be set up by the same increase rate as the solid line even when the second threshold is used (dotted line). In the exemplary relations between the light distribution angle and the steering angle shown in
Next, an exemplary basic operation of the interface controller 14 of the vehicle lamp system 1 will now be described with reference to
The road condition judgement part 20 can detect whether the traveling road of the own vehicle is the substantially straight or the curved road in accordance with the image data output from the imaging unit 10 (Step S10). In this case, the road condition judgement part 20 can refer the steering angle output from the steering angle sensor 13 (Step S10).
When the road condition judgement part 20 detects that the traveling road is the substantially straight (Step S10: YES), the threshold setup part 21 can set up the second threshold 3ST for the light distribution angle setup part 22 (Step S11). When the road condition judgement part 20 detects that the traveling road is not the substantially straight, that is, the traveling road is the curved road (Step S10: NO), the threshold setup part 21 can set up the first threshold 3FT for the light distribution angle setup part 22 (Step S12).
Next, the light distribution angle setup part 22 can detect whether the steering angle output from the steering angle sensor 13 exceeds the first threshold 3FT or the second threshold 3ST (Step S13). When the steering angle output from the steering angle sensor 13 exceeds the first threshold 3FT (Step S13: YES), the distribution angle setup part 22 can set up the light distribution angle in accordance with the solid line shown in
When the steering angle output from the steering angle sensor 13 is smaller than the first threshold 3FT (Step S13: NO), the light distribution angle setup part 22 cannot newly set up the light distribution angle and can maintain a previous light distribution angle such as the initial light distribution angle 30IA described above. The lamp unit control part 23 can produce the lamp driving signal to control the right and left lamp units 15R, 15L in accordance with the light distribution angle set up (or maintained) by the light distribution angle setup part 22, and can output the lamp driving signal to the right and left lamp units 15R, 15L (Step S15).
The right and left lamp units 15R, 15L can form the light distribution patterns along the traveling road in the traveling direction of the own vehicle in accordance with the lamp driving signal output from the lamp unit control part 23. The right and left lamp units 15R, 15L can provide the driver of the own driver with the preferable light distribution pattern by repeating the above-described Step S10 to Step S15.
According to the above exemplary embodiment, when the traveling road is the straight road, the vehicle lamp controller 2 can determine the light distribution angle with reference with the second threshold 3ST, which is set up at a relatively large threshold. Accordingly, the vehicle lamp system 1 can prevent the vehicle lamp controller 2 from frequently varying the light distribution angle. When the traveling road is the curved road, the vehicle lamp controller 2 can determine the light distribution angle with reference with the first threshold 3FT, which is set up at a relatively small threshold.
Therefore, the vehicle lamp system 1 can enable the vehicle lamp controller 2 to appropriately set up the light distribution angle, even when the traveling road is a curved road having a relatively large curvature radius. Thus, the vehicle lamp system 1 of the present invention can provide the driver of the own vehicle with the preferable light distribution patterns along the traveling road of the own vehicle.
Various modifications of the above disclosed embodiments can be made without departing from the spirit and scope of the present invention. For example, when the steering angle output from the steering angle sensor 13 exceeds the first threshold 3FT or the second threshold 3ST, cases where the vehicle lamp controller 2 can gradually vary the light distribution angle in accordance with the steering angle input into the interface controller 14 have been described. The initial light distribution angle 30IA is not necessarily set up at zero degree as shown in
In the above exemplary embodiment, the vehicle lamp system is described as an exemplary case where the present invention applies to Adaptive Front-Lighting System (AFS) such that forms the light distribution patterns along the traveling direction of the own vehicle. However, the vehicle lamp system 1 of the present invention can also apply to Adaptive Driving Beam (ADB) system, which can set up a variable light-emitting range of a high beam in accordance with other vehicles located in the forward direction of the own vehicle, pedestrians, etc.
When the vehicle lamp controller 2 detects an oncoming vehicle on the oncoming lane 101a located between the center line 102 and the second white line 101, the vehicle lamp controller 2 can turn off the light on 200H, 200I and 200J of the high beam 200 so as not to provide the oncoming vehicle with a glare type light, and can turn on the light on 200A to 200G of the high beam 200 in addition to the low beam 201 so as to provide the driver of the own vehicle with the preferable light distribution patterns. A headlight controller and a vehicle headlight system, which can independently select the light distribution regions, is disclosed in Patent Document No. 5 (U.S. Pat. No. 9,738,214) owned by Applicant of the present invention. Accordingly, details of the vehicle lamp system used as the ADB system is abbreviated here.
In the exemplary embodiment described above, the steering angle sensor 13 is used as the traveling angle-sensing part 3. A yaw rate sensor 17 can also be used as the traveling angle-sensing part 3 in place of the steering angle sensor 13 as shown in
When the yaw rate sensor 17 is used as the traveling angle-sensing part 3 in place of the steering angle sensor 13, the threshold setup part 21 can set up, for example, yaw rate 2.8 degrees/second as the first threshold instead of the steering angle 8 degrees, and also can set up 3.8 degrees/second as the second threshold instead of the steering angle 12 degrees. In these cases, when the yaw rate exceeds the first threshold of 2.8 degrees/second, the light distribution angle setup part 22 can set up the light distribution angle in accordance with the solid line shown in
Similarly, when the yaw rate exceeds the second threshold of 3.8 degrees/second, the light distribution angle setup part 22 can set up the light distribution angle in accordance with the dotted line shown in
In the above-described embodiments, the imaging unit 10 is employed as an exemplary method for detecting whether the traveling road of the own vehicle is the straight road or the curved road. The vehicle lamp system 1 cannot be limited to the imaging unit 10. By associating the imaging unit 10 with a millimeter-wave radar, a light detection and ranging (LiDAR) and the like, which may measure a distance between the own vehicle and the things such as vehicles moving in a frontward direction of the traveling road of the own vehicle, a guardrail, etc., the imaging unit 10 can improve a recognition accuracy thereof.
In addition, the vehicle lamp system 1 can detect whether the traveling road is the straight road or not by using data output from a car navigation system. In this case, when the data output from the car navigation system includes traveling road data such that the traveling road is the straight road or the carved road, the vehicle lamp system 1 can detect whether the traveling road is the straight road or not by detecting a location of the own vehicle using data output from a global positioning system (GPS) and by detecting whether the traveling road from the location of the own vehicle is the straight road or the curved road using the traveling road data. Thereby, the vehicle lamp system 1 can replace the imaging unit 10 with the car navigation system incorporated into the own vehicle. Accordingly, the vehicle lamp system 1 can be configured with a simple structure.
Next, an exemplary method for varying the second threshold will now be described with reference to
When the own vehicle travels on the straight road, a state such that the center line 102 in the image data output from the imaging unit 10 matches with the dot-line-referenced pattern 102PM may be continuously continued. In this case, the interface controller 14 can vary the second threshold at a larger value than the setup second threshold such as 12 degrees when using the steering angle sensor 13 and 3.8 degrees/second when using the yaw rate sensor 17, etc. For example, when the vehicle lamp system 1 includes the steering angle sensor 13, the threshold setup part 21 can change the second threshold from 12 degrees to 18 degrees, and when the vehicle lamp system 1 includes the yaw rate sensor 17, the threshold setup part 21 can change the second threshold from 3.8 degrees/second to 5.7 degrees/second.
When vehicles coming from a backward direction of the own vehicle overtakes the own vehicle and squeezes in front of the own vehicle from a rightward direction, the drivers of the own vehicle may accidentally turn the steering wheel in a leftward direction of the own vehicle. However, the vehicle lamp controller 2 may maintain the initial light distribution angle 30IA so as not to direct the light distribution angle toward a first walkway 103a located adjacent the first white line 100, because the threshold setup part 21 varies the second threshold at the larger value than the setup second threshold.
When a motorcycle coming from the backward direction of the own vehicle overtakes the own vehicle and squeezes in front of the own vehicle from a leftward direction, the drivers of the own vehicle may accidentally turn the steering wheel in a rightward direction of the own vehicle. However, the vehicle lamp controller 2 may maintain the initial light distribution angle 30IA so as not to direct the light distribution angle toward a second walkway 104a located adjacent the second white line 101, because the threshold setup part 21 varies the second threshold at the larger value than the setup second threshold.
As the own vehicle approaches the intersection 105, the center line 102 in the image data output from the imaging unit 10 becomes unable to match with the dot-line-referenced pattern 102PM. Only three dotted line 102, which matches with the dot-line-referenced pattern 102PM (four dotted line) near the intersection 105, is shown in
In these cases, when the own vehicle turns a left at the intersection 105, the interface controller 14 can smoothly vary the light distribution angle from the first threshold, which is used for the curved road, even when the own vehicle travels toward the intersection 105 on the straight roar. When the own vehicle moves straight ahead, the interface controller 14 can maintain the initial light distribution angle 30IA, even when the own vehicle moves in the intersection 105 because the vehicle practically moves straight ahead.
Various modifications of the above disclosed embodiments can be made without departing from the spirit and scope of the presently invention. For example, cases where the road condition judgement part 20 detects whether the traveling road of the own vehicle is the straight road or the curved road in accordance with the shape of the white lines are described. However, the white lines cannot be limited to the road condition judgment part 20, and the guardrails, the curbstones and the like, which extend along the traveling road of the own vehicle, can be used for detecting whether the traveling road is the straight road or the curved road. In addition, the specific arrangement between components can vary between different applications, and several of the above-described features can be used interchangeably between various embodiments depending on a particular application of the vehicle lamp controller.
While there has been described what are at present considered to be exemplary embodiments of the invention, it will be understood that various modifications may be made thereto, and it is intended that the appended claims cover such modifications as fall within the true spirit and scope of the invention. All conventional art references described above are herein incorporated in their entireties by reference.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2018-099038 | May 2018 | JP | national |
