METHOD FOR CONTROLLING DIRECTIONAL LIGHTING AND LIGHTING DEVICE EMBODIMENT FOR CARRYING OUT THE METHOD - Patent application

Abstract

METHOD FOR CONTROLLING DIRECTIONAL LIGHTING AND LIGHTING DEVICE EMBODIMENT FOR CARRYING OUT THE METHOD - Patent application The present invention relates to a method (100) for controlling bent light generated by a vehicle lighting device emitting a luminous flux that varies according to the motion of the vehicle, the method comprising the steps of: - a) determining (110) at least three initial beam images (Im1, Im2, Im3), each initial beam image corresponding to an emission of light by an illumination device in a given direction; - d) determining an intermediate light beam image (Im4) to be emitted by the lighting device in an intermediate direction when the vehicle is not following one of the predetermined directions, by taking a weighted average (170) of two of the three initial light beam images (Im1, Im2, Im3) corresponding to the directions closest adjacent to the intermediate direction; - e) Projecting (130, 180) an initial or intermediate light beam image onto the road scene depending on the direction of movement of the vehicle.

Description

[Technical field]

[0001] The present invention relates to a method for controlling the curved light, also known as directional light, emitted by a vehicle lighting device towards a road landscape, the light bundle image being adapted to the respective direction of movement of the vehicle. The present invention also relates to a vehicle lighting device employing this method.

[0002] The invention is applicable in the field of illumination of road scenes by road vehicles, such as automobiles, in particular in the field of bent light, where the generated illumination varies depending on the movement of the vehicle. [Background technology]

[0003] For safety reasons, automotive lighting devices have undergone many developments in recent years to improve the driver's visibility while complying with regulations. To improve the driver's visibility, a particular lighting device or headlight allows the light beam to be reconfigured depending on the vehicle's speed, weather conditions, whether other vehicles are passing, etc. Certain improvements have been made to FBL (FBL stands for Fixed Bending Light) systems. Other improvements have been made to DBL (DBL stands for Dynamic Bending Light) systems.

[0004] In a DBL system, the lighting device follows the path of the car, for example in corners, in order to illuminate the best possible road scene for the driver. Typically, the reach of the light beam of the headlight moves to the right or left depending on the angle of the steering wheel of the vehicle and / or the speed of the vehicle in order to brightly illuminate the road scene in the direction in which the vehicle is traveling. In a DBL system, the light beam is typically formed by light-emitting diodes (also called LEDs) arranged in a line or to form a screen (i.e. several rows and columns), the brightness of which may vary. Thus, due to the illumination generated by the light-emitting diodes, the light flux emitted by the headlight may vary, forming a light flux image with different brightness in different areas of the image. An example of such a light flux image, also called a light map, is shown in FIG. 1. The image of FIG. 1 corresponds to a light flux image emitted by the headlight when the vehicle is traveling in a straight line.

[0005] One current DBL technique consists in translating the light beam image (e.g., the image in FIG. 1) to shift the light beam to the right or left when the vehicle turns right, or to the left when the vehicle turns left. Another current DBL technique consists of compressing one of the light beam images and stretching the other of the images to shift the light beam to the left or right.

[0006] Both of these current techniques keep the same beam image shifted to the right or left, however, in certain situations it may be advantageous to change the intensity, for example so that the maximum intensity is higher or conversely lower, which cannot be achieved by simply shifting the beam image to one side or the other.

[0007] Furthermore, new regulations require that lighting on the right side have certain characteristics, and lighting on the left side have other certain characteristics, which cannot be produced with current DBL technology. Summary of the Invention

[0008] To address the above-mentioned problems of the light beam image shifting to the left or right and to comply with the new regulations, the applicant has developed a method of controlling bent light in which at least three different initial light beam images are generated, from which an intermediate light beam image can be defined by applying a weighted average.

[0009] According to a first aspect, the invention relates to a method for controlling bent light generated by a vehicle lighting device emitting a luminous flux towards a road scene that varies according to the movement of the vehicle, said method comprising the following steps: - a) determining at least three initial beam images, each initial beam image corresponding to an emission of light by the lighting device in a predetermined direction; - d) determining an intermediate light beam image to be emitted by the lighting device in the intermediate direction when the vehicle is not following one of the predetermined directions by taking a weighted average of two of the three initial light beam images corresponding to the directions most closely adjacent to the intermediate direction; - e) Projecting an initial or intermediate light beam image onto the road scene depending on the direction of movement of the vehicle.

[0010] The method allows a specific beam image to be determined for each direction taken by the vehicle between the leftmost and rightmost directions.

[0011] Advantageously, the three initial beam images are a left lateral initial beam image emitted by the lighting device towards the left side of the vehicle; a right lateral initial light beam image emitted by the lighting device towards the right side of the vehicle; a central initial light beam image emitted by the lighting device towards the centre of the vehicle.

[0012] These three images make it possible to determine a light beam image intermediate between the left lateral initial image and the central initial image for all vehicle directions between the leftmost direction and the central direction, and a light beam image intermediate between the central initial image and the right lateral initial image for all vehicle directions between the central direction and the rightmost direction. Thus, a light beam image adapted to any direction of movement of the vehicle can be projected onto the road, which direction of movement can be any direction included in the range of possible directions between the maximum left and maximum right turning angles allowed by the vehicle. Thus, the driver of the vehicle sees a road scene that is always optimally illuminated throughout the movement of the vehicle and whatever the path of the vehicle.

[0013] By definition, a given beam image corresponding to a given direction and / or one particular DBL angle is referred to as an "initial image." Furthermore, the given direction is also referred to as an "initial direction," and one particular DBL angle is also referred to as an "initial DBL angle," in contrast to the DBL angle of a moving vehicle.

[0014] Apart from the features mentioned above in the previous paragraphs, the method for controlling bent light according to an aspect of the invention comprises one or more of the following complementary features, which can be implemented individually or in any technically feasible combination: before operation d) of determining the intermediate beam image, a first operation c1) of translating a first initial light beam image corresponding to one of the two directions that are closest to and adjacent to the intermediate direction; a second movement c2) of translating the second initial light beam image corresponding to the other of the directions most adjacent to the intermediate direction, the first movement c1) being performed in a direction opposite to the direction of the second movement c2); - it includes an operation b) of determining a proportional position of an intermediate image between the first initial beam image and the second initial beam image, the positioning coefficient being deduced from said proportional position, the positioning factor is applied in operations c1) and c2) of translating the first and second initial beam images, The positioning factor is applied in operation d) of weighted averaging the two initial beam images.

[0015] According to a second aspect, the invention relates to a vehicle curved light lighting device for emitting a light flux for illuminating a road scene depending on the movement of the vehicle, characterized in that it implements a method as defined above.

[0016] Advantageously, the lighting device comprises a plurality of light-emitting diodes in the form of a row or a screen, the luminous intensity of which is varied so as to generate at least three initial light beam images.

[0017] Other advantages and characteristics of the invention will become apparent from the following description, which is given in the drawings. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a diagram showing an example of a light beam image conventionally used in a DBL system, as already described. [Diagram 2] 2 illustrates, in flow chart form, one embodiment of various operations of a method in accordance with the present invention. [Diagram 3] FIG. 2 shows an example of an initial beam image produced by the method according to the invention; [Figure 4] 13A-13C show various beam images used in the method according to the invention when the DBL angle is 0°. [Diagram 5] 13A-13C show various beam images for use in the method according to the invention when the DBL angle is 100°. [Figure 6] 11A-11C show various beam images for use in the method according to the invention when the DBL angle is -100°. [Figure 7] 13A-13C show various beam images used in the method according to the invention when the DBL angle is +40°. [Figure 8] 13A-13C show various beam images for use in the method according to the invention when the DBL angle is +80°. [Figure 9] 13A-13C show various beam images used in the method according to the invention when the DBL angle is -60°. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] An embodiment of a method for controlling bent light generated by a vehicle headlamp will be described in detail below with reference to the accompanying drawings. This embodiment will explain the features and advantages of the present invention. However, it will be recalled that the present invention is not limited to this embodiment.

[0020] In the figures, identical elements are identified using identical reference numbers. For readability of the figures, elements in the figures are not drawn to scale.

[0021] One embodiment of a method 100 according to the present invention is illustrated in flow chart form in Figure 2. The method includes a first operation 110 of generating initial beam images. These initial beam images, or simply initial images, are beam images emitted by the headlights of a vehicle when the vehicle is moving in a predefined direction. There are at least three initial images, corresponding to three different predefined directions.

[0022] An example of three initial images is shown in Fig. 3. In the example of Fig. 3, the initial image Im1 is an example of a light beam generated for a vehicle traveling in a straight line, i.e., following a straight path. When the vehicle is traveling in a straight line, the DBL angle corresponding to the direction the vehicle follows is equal to 0. The initial image Im1 for a vehicle moving in a straight line is called the central initial image.

[0023] In the embodiment of Fig. 3, the initial image Im1 is an example of a light beam generated for a vehicle that turns fully right, i.e., follows a curved path that is oriented fully to the right. When the vehicle turns fully right, i.e., the steering wheel angle is fully to the right, the DBL angle is considered to be equal to +100. The initial image Im2 for the vehicle that turns fully right is called a right lateral initial image.

[0024] In the embodiment of Fig. 3, the initial image Im3 is an example of a light beam generated for a vehicle turning fully left, i.e. following a curved path oriented fully leftward. When the vehicle is turning fully left, i.e. the steering wheel angle is maximum to the left, the DBL angle is considered to be equal to -100. The initial image Im3 for a vehicle turning fully left is called a left lateral initial image.

[0025] The three initial images Im1, Im2 and Im3 are predefined images that meet regulatory requirements. These three images Im1, Im2, Im3 are determined by the manufacturer of the lighting device and implemented in the lighting device before the vehicle is put into service or when the lighting device is updated by a specialist.

[0026] The minimum number of initial images with which the method of the invention can be implemented is three. The number of initial images may be greater than three, for example equal to five. When there are three initial images, these preferably comprise a left lateral initial image Im3, a right lateral initial image Im2 and a central initial image Im1. When installing more than two initial images in the lighting device, the two images complementary to Im1, Im2 and Im3 may be images inserted between the central initial image Im1 and the left and right lateral initial images Im3 and Im2, for example, corresponding to DBL angles of +50 and -50. Regardless of the number of initial images, the method 100 is applied in the same way as described below.

[0027] After generating the initial images Im1, Im2, Im3, the method 100 checks in test 120 whether the vehicle DBL angle corresponds to one of the predetermined initial directions. In other words, the method 100 checks whether the vehicle DBL angle corresponds to one of the initial DBL angles for which the initial images are defined. If so, the method proceeds to operation 130, where an initial beam image corresponding to the initial DBL angle is projected onto the road scene. For example, if the test 120 determines that the vehicle DBL angle corresponds to the initial DBL angle +100, the initial image Im2 is projected onto the road.

[0028] In contrast, if the vehicle DBL angle does not correspond to one of the initial DBL angles, the method proceeds to step 140, which determines the initial direction that is most closely adjacent to the vehicle DBL angle. In other words, in step 140, it is determined which initial DBL angle is adjacent to the DBL angle of the moving vehicle. For example, if the vehicle DBL angle is equal to +40, the initial DBL angles adjacent to this DBL angle +40 are DBL angle +100 and DBL angle 0. According to another example, if the vehicle DBL angle is equal to -60, the initial DBL angles adjacent to this DBL angle -60 are DBL angle -100 and DBL angle 0.

[0029] Then, the method 100 proceeds to steps 150 and 160 of translating the initial images. In step 150, the initial images corresponding to the right initial DBL angle, i.e., the DBL angle whose value is greater than the vehicle DBL angle (adjacent to the right side of the vehicle DBL angle), are translated to the left. In step 160, the initial images corresponding to the left initial DBL angle, i.e., the DBL angle whose value is less than the vehicle DBL angle (adjacent to the left side of the vehicle DBL angle), are translated to the right. For example, if the vehicle DBL angle is equal to +40, the right lateral initial image Im2 (corresponding to a DBL angle of +100) is translated to the left, and the central initial image Im1 (corresponding to an initial DBL angle of 0) is translated to the right. In another example, if the vehicle DBL angle is equal to -60, the left lateral initial image Im3 (corresponding to a DBL angle of -100) is translated to the right, and the central initial image Im1 (corresponding to an initial DBL angle of 0) is translated to the left.

[0030] The translation steps 150 and 160 are preferably applied taking into account a positioning factor determined from the proportional position of the vehicle DBL angle relative to the closest initial DBL angle. In particular, step 140 of the method may incorporate an operation of determining the proportional position of an intermediate image between a first initial image, e.g., an initial image corresponding to a right-side initial DBL angle, and a second initial image, e.g., an initial image corresponding to a left-side initial DBL angle. A positioning factor is then estimated from this proportional position.

[0031] For example, for a vehicle DBL angle equal to +40, the positioning factor is 40 / 60, the central initial image Im1 is translated by 40 to the right and the right lateral initial image Im2 is translated by 60 to the left, 40 and 60 being proportional numbers given, for example, in percentages or pixel numbers. In another example, for a vehicle DBL angle equal to -60, the positioning factor is 60 / 40, the central initial image Im1 is translated by 60 to the left and the left lateral initial image Im3 is translated by 40 to the right.

[0032] Following steps 150 and 160, the two initial images corresponding to the initial DBL angle closest to the vehicle DBL angle, for example Im1 / Im2 or Im1 / Im3, are superimposed.

[0033] The method 100 proceeds to step 170, where a weighted average of the two translated initial images is applied. The averaging of these two initial images is performed by weighting each of the two images according to the positioning coefficients used in steps 150 and 160. For example, if the vehicle DBL angle is equal to +40, the weight used for the central initial image Im1 is 40% and the weight used for the right lateral initial image Im2 is 60%. In an embodiment where the vehicle DBL angle is -60, the weight of the central initial image Im1 is 60% and the weight of the left lateral initial image Im3 is 40%. In an embodiment where the vehicle DBL angle is -20, the weight of the central initial image Im1 is 20% and the weight of the left lateral initial image Im3 is 80%.

[0034] The averaging of the two translated initial images may for example be performed pixel-by-pixel or by any other image averaging technique known in the art of image processing.

[0035] The image Im4 obtained after applying the weighted average to the two translated initial images is called the intermediate beam image, or simply the intermediate image. Then, in step 180, this intermediate image Im4 is projected onto the road.

[0036] Some examples of initial and / or intermediate images are shown in Figs. 4 to 9. In all these examples, the number of initial images is three, The initial image referred to as -A is the left lateral initial image corresponding to the initial DBL angle of -100 (or the leftmost DBL angle). The initial image referred to as -B is the central initial image corresponding to the initial DBL angle of 0, i.e., the central DBL angle. The initial image referred to by -C is the right lateral initial image corresponding to the initial DBL angle of +100 (or the rightmost DBL angle); and The image referred to by -D is the resulting image projected onto the road (ie the initial image or the intermediate image, as the case may be).

[0037] In the examples of Figures 4-9, the number of pixels (px) corresponds to a positioning factor applied to the translation of the translated initial image, and the number of percentages (%) corresponds to a weighting applied during the averaging of the translated initial images. The initial images A, B, and C of Figures 4-9 that are not associated with a number of pixels are initial images that are not used to determine the projected image D.

[0038] In the embodiment of Figure 4, the vehicle DBL angle is an initial DBL angle of 0. Therefore, the projected image D is the central initial image (image B).

[0039] 5, the vehicle DBL angle is the initial DBL angle +100. Therefore, the projected image D is the right lateral initial image (image C).

[0040] 6, the vehicle DBL angle is an initial DBL angle of −100. Therefore, the projected image D is a left lateral initial image (image A).

[0041] In the embodiment of Fig. 7, the vehicle DBL angle is an intermediate angle of +40. Therefore, the translated initial images are a central initial image (image B) translated by +40px (i.e., 40px to the right) and a right lateral initial image (image C) translated by -60px (i.e., 60px to the left). Thus, the projected image D is an intermediate image obtained by averaging image B with a weight of 60% and image C with a weight of 40%.

[0042] In the embodiment of Fig. 8, the vehicle DBL angle is an intermediate angle of +80. Therefore, the initial images to be translated are a central initial image (image B) translated by +80px (i.e., 80px to the right) and a right lateral initial image (image C) translated by -20px (i.e., 20px to the left). Therefore, the projected image D is an intermediate image obtained by averaging image B with a weight of 20% and image C with a weight of 80%.

[0043] In the embodiment of Fig. 9, the vehicle DBL angle is an intermediate angle -60. Therefore, the initial images to be translated are a left lateral initial image (image A) translated by +40px (i.e., 40px to the right) and a central initial image (image B) translated by -60px (i.e., 60px to the left). Therefore, the projected image D is an intermediate image obtained by averaging image A with a weight of 60% and image B with a weight of 40%.

[0044] Above, an embodiment of the method 100 is described in which three initial images Im1, Im2, and Im3 are defined. It will be understood that the same method can be applied in the same way regardless of the number of initial images defined. If more than three initial images are defined, the initial images to be translated and averaged are the two initial images corresponding to the two initial DBL angles closest to the vehicle DBL angle. For example, if five initial images are defined for initial DBL angles of +0, +50, +100, -50, and -100, and the vehicle DBL angle is +20, the initial images to be translated and averaged are the initial image corresponding to the initial DBL angle +0 and the initial image corresponding to the initial DBL angle +50.

[0045] The method as described above may be implemented in many kinds of lighting devices, provided that the emitted light intensity can be varied, such as, for example, matrix lighting devices, scanning laser lighting devices, lighting devices based on LED screens or micro LED screens, etc. For example, in a LED-based lighting device, the power of each LED may be controlled, for example, by a control unit, thus generating different initial light flux images for different selected initial DBL angles.

[0046] While described with a specific number of examples, variations, and embodiments, it is understood that the method for controlling bent light according to the present invention includes various variations, modifications, and improvements that would be apparent to one skilled in the art, and that these variations, modifications, and improvements form part of the scope of the present invention.

Claims

1. A method (100) for controlling bent light generated by a lighting device that emits a luminous flux towards a road scene that varies depending on the movement of a vehicle, comprising: (a) determining (110) at least three initial beam images (Im1, Im2, Im3), each initial beam image corresponding to an emission of light by said illumination device in a predetermined direction; (d) when the vehicle is not following one of the predetermined directions, determining an intermediate light beam image (Im4) to be emitted by the lighting device in the intermediate direction by weighted averaging (170) two of the three initial light beam images (Im1, Im2, Im3) corresponding to directions closest to an intermediate direction; (e) projecting (130, 180) the initial beam image or the intermediate beam image onto the road scene depending on the direction of travel of the vehicle; A method (100) comprising:

2. The three initial beam images are: a left lateral initial light beam image (Im3) emitted by the lighting device toward the left side of the vehicle; a right lateral initial light beam image (Im2) emitted by the lighting device toward the right side of the vehicle; a central initial light beam image (Im1) emitted by the lighting device towards the centre of the vehicle; The method of claim 1 , comprising:

3. before the operation (d) of determining the intermediate beam image, (c1) a first operation of translating (150) a first initial beam image corresponding to one of the directions most closely adjacent to the intermediate direction; (c2) a second operation of translating (160) a second initial beam image corresponding to the other of the directions that is closest to the intermediate direction; Including, the translational movement (150) in the first movement (c1) is performed in a direction opposite to the direction of the translational movement (160) in the second movement (c2); The method of claim 1.

4. (b) determining a proportional position of an intermediate image between the first initial beam image and the second initial beam image; and a positioning factor is estimated from the proportional position. The method of claim 3.

5. the positioning coefficient is applied in the first operation (c1) of translating (150) the first initial beam image and in the second operation (c2) of translating (160) the second initial beam image; The method of claim 4.

6. The positioning coefficients are applied in operation (d) of weighting (170) the initial beam images. The method of claim 4.

7. A vehicle curved light illumination device that emits a light beam to illuminate a road scene in response to the movement of the vehicle, the device implementing the method according to any one of claims 1 to 6. Vehicle bending light lighting device.

8. a plurality of light-emitting diodes in the form of a row or a screen, the luminous intensities of the light-emitting diodes being varied to generate at least three initial light beam images (Im1, Im2, Im3); 8. The vehicle curved light illumination device according to claim 7.

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