Method for controlling lighting system using non-illusory lighting function

Abstract

To provide a vehicle lighting system that enables emission of a lighting beam capable of optimally lighting roads including traffic signs, and does not generate a source of dazzle to a driver nearby a traffic sign.SOLUTION: A method comprises the stages of: detecting a traffic sign by a sensor system of an automotive vehicle; estimating a passage time between a point of time when the traffic sign is detected and a future point of time when the automotive vehicle passes by the detected traffic sign; and controlling a basic light source of a lighting system of a host vehicle to emit a pixellated light beam, wherein some part in the basic light source is controlled according to the passage time so as to form an area of lower light intensity in the light beam spreading to the vicinity of the traffic sign.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to the field of lighting of motor vehicles. Specifically, the present invention relates to a method for controlling a lighting system of a motor vehicle using an anti-glare lighting function.

Background Art

[0002] Motor vehicles are usually equipped with a lighting system, in particular a lighting system capable of emitting a controlled main beam type lighting function that can optimally illuminate the road on the downstream side of the vehicle.

[0003] Although this type of beam can sufficiently improve the driver's visibility, it can also be a source of discomfort for the driver. In fact, the lighting beam of the main beam may reach the road signs and be retroreflected towards the driver. And this retroreflection can be a source of glare, especially when the signs are provided with reflecting means, when the light output of the lighting beam is particularly high, when the ambient luminance is already high, or even when the driver is sensitive to glare.

[0004] It is known that motor vehicles are equipped with a sensor system for detecting road signs on the road and a controller capable of switching the lighting system to emit a non-glare beam (for example, a passing beam type) when such a sign is detected. In this way, the source of glare is removed to eliminate the driver's discomfort.

[0005] However, this solution is not sufficient. On the one hand, by emitting such a non-glare beam, the lighting of the rest of the road is also reduced, and the driver's visibility is no longer optimal. Furthermore, the road signs are no longer illuminated, and the driver can no longer perceive and recognize the signs. Finally, modern vehicles are usually equipped with cameras that enable the implementation of driving assistance functions, and in this case, the camera may need to be able to read the signs. In this case, the camera may also be unable to read the signs due to the lack of lighting on the signs, thus causing the driving assistance function not to operate.

[0006] There is a need for a solution that overcomes the various drawbacks listed above and enables, in particular, the emission of a lighting beam that optimally illuminates a road, including road signs, without creating a source of dazzle for the driver in the vicinity of the signs. SUMMARY OF THE INVENTION

[0007] The present invention lies within the scope of this context and aims to address this requirement.

[0008] For this purpose, the aim of the present invention is a method for controlling an illumination system of a motor vehicle, the illumination system comprising a plurality of basic light sources that can be selectively controlled to emit respective basic light beams, the basic light beams together forming a pixelated light beam, the method comprising: a. detecting a road sign by means of a sensor system of the motor vehicle; b. estimating the passing time between the time when the road sign is detected and a future time when the motor vehicle will pass the detected road sign; c. controlling the basic light sources of the illumination system of the host vehicle so as to emit a pixelated light beam, wherein a portion of the basic light sources is controlled according to the passing time so as to create a region of lower luminous intensity within the light beam spreading in the vicinity of the road sign. It is a method provided with...

[0009] Due to the effect of the present invention, especially thanks to the use of an illumination system capable of emitting a pixelated light beam, less light is emitted near this sign while avoiding the retroreflection of road signs that would deceive the driver, and it becomes possible to illuminate the entire road on the downstream side of the vehicle including the area near this sign. Furthermore, by estimating the time interval between the time of detection of a road sign and the future time when the detected sign will be passed by the vehicle, it has been found that the amount of light that must be emitted towards this sign can be accurately and highly controlled so as to optimize the detection and recognition of this sign by the driver of the vehicle or a camera.

[0010] The lower-luminance area is an area illuminated by all the basic light beams emitted by the basic light source of that part, and it should be understood that within this area, each of the basic light beams emitted by the basic light source has a luminance lower than the nominal luminance that would be emitted by this basic light source. For example, the luminance of this basic light source can be substantially lower than the luminance of each of the basic light beams forming the rest of the pixelated light beam.

[0011] The step of detecting a road sign can advantageously be carried out by a camera mounted on the vehicle.

[0012] In one embodiment of the present invention, during the detection step, the sensor system estimates the distance separating the road sign from the vehicle, and during the step of estimating the passing time, the passing time is estimated according to the distance and the speed of the host vehicle. If desired, the sensor system estimates the distance separating the sensor system from the road sign and the angle between the sensor system and the road sign. Then, during the step of estimating the passing time, the passing time is estimated according to the distance, the angle, and the speed of the vehicle.

[0013] In another embodiment of the present invention, during the detection stage, the sensor system measures the illuminance of the road sign by the lighting system. If applicable, during the stage of estimating the passing time, the distance separating the road sign from the motor vehicle is estimated according to the measured illuminance and the luminous intensity emitted towards the sign by the lighting system, and during the stage of estimating the passing time, the passing time is estimated according to the said distance and the speed of the host motor vehicle. The method according to the present invention can thus be deployed in vehicles equipped with low-performance sensor systems. For example, if the sensor system comprises a camera capable of acquiring an image of the road, the illuminance of the road sign can be determined using the luminous intensity of each pixel located in the vicinity of the road sign in this image, or based on the luminance of the road sign that this camera would be able to estimate. If the luminous intensity emitted by the directional lighting system is known in advance (since it is the set value of the basic light source), the distance separating the road sign from the motor vehicle can be calculated, for example, by Bouguer's law formulated by the following equation.

Number

[0014] The method can comprise the stage of estimating the level of dazzle of the driver of the motor vehicle by the road sign and comparing this dazzle level with a given dazzle threshold, and the stage of controlling the basic light source so as to create a zone of lower luminous intensity within the light beam can be advantageously conditional on the fact that the dazzle level is higher than the given dazzle threshold. Thanks to this feature, it is thus possible not to activate the anti-dazzle function of this road sign if the road sign is not considered to be dazzling. In this case, the road sign is thus illuminated at the nominal luminous intensity by the pixelated light beam.

[0015] For example, it is possible to measure the luminance of a road sign and estimate the dazzle level from the logarithm of this luminance. This dazzle level is defined in particular according to the de Boer scale. The scale describes the intensity of the perceived discomfort by the following values: 1 (hardly noticeable), 3 (acceptable limit), 5 (obstructive), 7 (satisfactory), 9 (intolerable). The dazzle threshold can be set to 3, for example.

[0016] In an alternative or cumulative example, the step of the sensor system estimating the luminance and the dimensions of the road sign and controlling the primary light source to create a region of lower luminance within the light beam is conditional on the fact that the luminance of the road sign is higher than a given threshold and the fact that the dimensions of the road sign are larger than a given threshold.

[0017] It is advantageous for the method to comprise the step of comparing the (estimated, in particular as soon as the step of detecting the road sign is completed) transit time with a minimum threshold. If the transit time is shorter than the minimum threshold, during the step of controlling the primary light source, each primary light source of the part intended to create a region of lower luminance is controlled to emit the primary light beam at a constant luminance as the motor vehicle moves towards the road sign. According to this feature, when the motor vehicle is too close to the road sign, the luminance emitted towards the road sign will not generate a dazzling retroreflection, but will be reduced to a constant value just sufficient for the road sign to be perceived and recognized by the driver of the motor vehicle or by a camera. For example, the constant luminance can be in the range between 20% and 30% of the nominal luminance that would be emitted by this primary light source, and in particular can be 26%.

[0018] Advantageously, the method comprises comparing the (presumably, once the step of detecting the road sign is completed) elapsed time with a minimum threshold value. If the elapsed time is longer than the minimum threshold value, during the step of controlling the basic light sources, each basic light source of the part intended to create a lower light intensity area is controlled to emit a basic light beam whose light intensity decreases as the vehicle moves towards the road sign. Thanks to this feature, it is possible to ensure that as the time interval between the current time and the future time when the vehicle will pass the road sign becomes shorter, the luminance of the road sign produced by the lighting system illuminating the road sign is decreased. Thereby, it is ensured that while the vehicle is moving, the illuminance of the road sign is not sufficient to dazzle the driver by retroreflection, but is sufficient for the driver and the camera to perceive and recognize the road sign. Note that if the elapsed time is below a given minimum threshold value, during the step of controlling the basic light sources, it is advantageous for each basic light source of the part intended to create a lower light intensity area to be controlled to emit a basic light beam with a constant light intensity when the vehicle moves towards the road sign.

[0019] The method preferably comprises selecting one of a plurality of control rules according to the value of the elapsed time, each control rule defining the evolution of the light intensity to be emitted as a function of the increase in time. If applicable, each basic light source of the part intended to create a lower light intensity area is controlled by the selected control rule to emit a basic light beam with a light intensity determined according to the value of the remaining time until the vehicle passes the road sign. In other words, the remaining time until the vehicle passes the road sign is periodically estimated from the detection of the road sign while the vehicle is moving. And for each value of this remaining time, the light intensity of each light source is determined anew. Thus, a plurality of lighting profiles of the road sign are defined by the lighting system so as to optimize the perception and understanding of the road sign by the driver and the camera when the vehicle is moving.

[0020] If desired, each control rule among the plurality of control rules is associated with at least one distinct passage time, in particular a range of distinct passage times. If applicable, the increasing function of each control rule has an increasing rate, and for a first control rule associated with a passage time longer than the passage time associated with a second control rule, the increasing rate of the increasing function of the first control rule is lower than the increasing rate of the increasing function of the second control rule.

[0021] For example, the increasing function of each control rule is a power function of time, and the exponent of the power function is associated with the passage time related to this control rule. This power function can be defined, for example, by the following equation.

Equation

[0022] Thus, the longer the estimated passage time when the road sign is detected, the smaller the exponent β of the power function in the control rule that will be selected, i and / or the larger the magnitude α of the power function in the control rule that will be selected. It should be understood that in this way, an appropriate reduction in speed towards a certain value of the luminance of the road sign according to this initial passage time is thus ensured. For each control rule among the plurality of control rules, it is advantageous that the exponent β of the power function associated with this control rule i is less than 2. i is less than 2.

[0023] During the stage of controlling the basic light source, it is advantageous to control the basic light source to emit a non-glare main-beam type pixelated light beam.

[0024] During the stage of controlling the basic light source, it is preferable that the relevant part of the basic light source can be controlled according to the passing time so as to generate an area with an edge surrounding the road sign within the light beam.

[0025] For example, during the stage of detecting the road sign, the sensor system can be configured to estimate a pair of horizontal angles between the sensor system and both side ends of the road sign, and / or a pair of vertical angles between the sensor system and the upper and lower ends of the road sign. If applicable, the method can include, for example, a stage of determining a pair of horizontal angles and / or vertical angles between the lighting system and both side ends and / or the upper and lower ends by means of a reference exchange operation. And the relevant part of the basic light source that has to be controlled to generate the lower-luminance area is a basic light source that can emit the following basic light beam. That is, it is a basic light beam in which its emission cone is at least partially included in the horizontal direction and / or the vertical direction within the range defined by a pair of pre-determined horizontal and / or vertical angles. These stages of determining the pair of angles and controlling the basic light source are advantageously updated periodically while the motor vehicle is moving. As a result, during this movement, the edges of the area surround the road sign.

[0026] It is advantageous that the relevant part of the basic light source is controlled to generate a lower-luminance area (within the light beam) throughout the entire travel duration of the motor vehicle between the time when the road sign is detected and the future time when the detected road sign will be passed by the motor vehicle. If applicable, after the motor vehicle has passed the road sign, the relevant part of the basic light source can be controlled to generate a basic light beam with a nominal luminance respectively.

[0027] A further object of the present invention is a motor vehicle comprising a sensor system, a lighting system, and a controller, wherein the controller, the sensor system, and the lighting system are configured to perform the method according to the present invention.

[0028] It is advantageous for the lighting system to comprise a plurality of selectively controllable basic light sources, each of which can emit a basic light beam with a vertical angular aperture of less than 1°, in particular. If applicable, all basic light sources may be able to emit a pixelated light beam that extends in the horizontal direction in the range from -16° to +16° and in the vertical direction in the range from -1° to +6° with respect to the horizontal line.

[0029] In one embodiment of the invention, the lighting system comprises a light module having a pixelated light source including a plurality of basic light emitters arranged in a matrix and an optical projection element associated with the pixelated light source. Each of the basic light emitters is adapted to selectively operate to form a basic light source and emit a basic light beam. The optical projection element is associated with projecting each of the basic light beams onto a road. For example, the pixelated light source comprises at least one matrix of light emitting elements (referred to as a monolithic array), in particular at least one matrix of monolithic light emitting elements (also referred to as a monolithic array).

[0030] As an alternative embodiment, the light module can comprise, for example, at least one light emitting diode that emits light and a light source formed by a matrix of optoelectronic elements, for example a matrix of micromirrors (also known as a digital micromirror device (DMD)). The matrix array of the optoelectronic elements directs the light rays generated from the at least one light source towards the optical projection element by reflection.

[0031] Here, the present invention will be described with reference to the accompanying drawings using examples that are merely illustrative and in no way limit the scope of the present invention.

Brief Description of the Drawings

[0032]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 5

Mode for Carrying Out the Invention

[0033] Throughout the following description, elements that are equivalent in terms of structure or function and appear in various drawings are given the same reference numerals unless otherwise indicated.

[0034] FIG. 1 shows a part of a motor vehicle 1 according to an embodiment of the present invention. The motor vehicle 1 includes a sensor system 2 having a camera 21 configured to acquire an image of the road on the downstream side of the motor vehicle. The sensor system 2 further includes a computer 22 configured to perform various methods for processing the image acquired by the camera 21.

[0035] The motor vehicle 1 further includes a lighting system 3 having a light module 31. The light module 31 particularly includes a pixelated light source 32 associated with a lens 33. In the example to be described, the pixelated light source 32 is a monolithic pixelated light emitting diode. For this purpose, each of the light emitting elements forms a basic light source 32 i,j which can be selectively controlled by being operated by an embedded controller to emit light toward the lens 33. Thus, the lens 33 forms a basic light beam HD whose luminous intensity can be controlled i,j which can be selectively controlled by being operated by an embedded controller to emit light toward the lens 33. Thus, the lens 33 forms a basic light beam HD whose luminous intensity can be controlled i,jis projected onto the road. Each basic light beam HD i,j is projected by a lens into a given emission cone defined by a given emission direction and a given opening angle. Thus, in the example being described, in this way, all of the basic light beams HD i,j form a pixelated light beam HD having 500 pixels distributed over 25 columns and 20 rows, spreading over a horizontal range of angles from -16° to +16° and a vertical range of angles from -1° to +6° in the horizontal direction. Each pixel of the beam is formed by one of these basic light beams HD i,j One of the basic light sources 32 at the light source 32 i,j Each basic light beam HD emitted by one of them i,j has a horizontal and vertical opening angle of less than 1°.

[0036] The light module 31 includes a controller 34 configured to control an embedded controller of the pixelated light source 32. The control selectively controls the lighting, extinguishing, and light intensity change of each of the basic light beams HD i,j in response to instructions received from the computer 4 of the host vehicle 1. These instructions are determined in particular based on information provided by the computer 22 of the sensor system 2.

[0037] FIG. 2 shows a method for controlling the lighting system 3 according to an embodiment of the present invention. This method will be described with reference to FIGS. 3 and 4, which respectively illustrate a side view and a front view of the road site when performing the method of FIG. 2.

[0038] In step E1, the sensor system 2 detects the road sign 10 on the road. The road sign 10 generally has a circular, triangular, or rectangular shape, is generally coated with a reflective coating, and includes an inscription and / or a pictogram. Thus, particularly due to the fact that ambient light and light emitted by various road users are reflected towards the camera 21, it becomes possible to detect the presence of such a sign on the image acquired by the camera 21. Thus, means for image processing enabling such detection are provided to the computer 22.

[0039] Subsequent to said detection, in step E11, the computer 22 determines various characteristics of the road sign 10, in particular, a. the horizontal angles θ1 and θ2 between the camera 21 and both side ends of the road sign 10, b. the vertical angles ω1 and ω2 between the camera 21 and both upper and lower ends of the road sign 10, c. the distance d separating the camera 21 from the road sign 10. is determined.

[0040] In step E12, the computer 22 determines the luminance L of the road sign 10 caused by the retroreflection of the light emitted by the lighting system 3.

[0041] Finally, based on this luminance L, the computer can (at this same step) estimate the dazzle level Y from the logarithm of this luminance L (reduced to the range from 1 to 10 corresponding to the De Boer scale).

[0042] A set of parameters is provided to the computer 4. Based on the distance d measured at the time t0 when the road sign 10 is detected by the sensor system 2, in step E2, this computer estimates the passing time TBC separating this time t0 from a future time t1 (at which the motor vehicle 1 will pass this road sign 10). This passing time TBC can be calculated in particular by the distance d at the time t0 and the speed v of the motor vehicle 1. This speed v is known to the computer 4.

[0043] In stage E3, the illusion level Y is compared with a given (e.g., a value of 3) illusion threshold TS on the de Boer scale. Y and compared.

[0044] This illusion threshold TS Y If the actual illusion level Y is higher than this illusion threshold TS, in stage E4, the computer 4 uses a reference exchange operation to determine the horizontal angles V and V and the vertical angles V and V between the illumination system 3 and the upper and lower both side ends from the horizontal angles θ1 and θ2 and the vertical angles ω1 and ω2. Thus, the computer 4 selects a basic light source 32 that can emit a basic light beam HD (the emission cone of which is at least partially within the range defined by a set of predetermined angles V and V and V and V in the horizontal direction and / or the vertical direction). LG and V LD as well as the vertical angle V upp and V low are determined. Thus, the computer 4 selects a basic light source 32 that can emit a basic light beam HD (the emission cone of which is at least partially within the range defined by a set of predetermined angles V and V and V and V in the horizontal direction and / or the vertical direction). i,j that can emit a basic light beam HD i,j (the emission cone of which is at least partially within the range defined by a set of predetermined angles V and V and V and V in the horizontal direction and / or the vertical direction). LG and V LD as well as V upp and V low are included).

[0045] In stage E5, the passing time TBC is compared with the shortest threshold TS. min and compared.

[0046] If the passing time TBC is shorter than the shortest threshold TS min , in stage E61, the computer 4 sends a control setting value to the controller 34. It is such that each of the selected basic light sources 32 emits a basic light beam HD of a constant luminous intensity I (lower than the aforementioned nominal luminous intensity that can be emitted by this light source) during the entire passing time TBC. This constant luminous intensity is, for example, 26% of the nominal luminous intensity. i,j each emits a basic light beam HD of a constant luminous intensity I (lower than the aforementioned nominal luminous intensity that can be emitted by this light source) during the entire passing time TBC. i,j This constant luminous intensity is, for example, 26% of the nominal luminous intensity.

[0047] Thus, the selected basic light sources 32 i,j together form a lower luminous intensity area Z for the remaining part of the pixelated light beam HD. Cto generate it, and the area Z C It should be understood that the edge of surrounds the road sign 10. This area Z C is kept in an activated state centered on the road sign 10 throughout the entire movement of the vehicle 1 from time t0 to time t1. During this movement, the detection and estimation of the horizontal and vertical angles θ1, θ2, ω1, and ω2 are periodically updated.

[0048] When the passing time TBC is shorter than the shortest threshold TS min the computer 4 compares the passing time TBC with a plurality of passing time ranges in step E62. In the example to be described, the passing time TBC is compared with a first threshold TS1 and a second threshold TS2 that is longer than the first threshold TS1. These thresholds thus define three ranges, namely TS min ~TS1, TS1~TS2, and a time longer than TS₂.

[0049] Each range is associated with control rules L1, L2, L3 that define the progression of the light intensity I as a function of the increase in the remaining time until the vehicle 1 passes the road sign 10 (for this range).

[0050] In the example to be described, each function is a power function of the remaining time ttc, and the exponent of the power function is predetermined according to the associated range. Thus, the remaining time ttc is a time that changes with a value that decreases from the passing time TBC to 0.

[0051] Specifically, the range TS i ~TS j associated with the rule L i the exponent β i is larger than the exponent β j ~TS k associated with the rule L j In other words, the range TS j ~TS minThe exponent β1 of rule L1 associated with ~TS1 is greater than the exponent β2 of rule L2 associated with the range TS1~TS2, which is itself greater than the exponent β3 of rule L3 associated with a range of time longer than TS2.

[0052] Figure 5 shows the functions of these various rules L1 to L3 on the same graph, and it can be seen that the rate of increase of L1 is higher than the rate of increase of L2, which is itself higher than the rate of increase of L3.

[0053] In step E62, the computer 4 thus determines the rule L associated with the range in which the estimated value TBC falls when the road sign 10 is detected. i Then periodically, in step E63, the computer 4 estimates the remaining time ttc and sends control settings to the controller 34. It selects the selected basic light source 32. i,j Each of the basic light beams HD i,j It emits a basic light beam HD i,j The luminosity I of the i The remaining time ttc estimated at a given time is determined by the threshold TS min If it is below this, the set point issued by the computer 4 is a constant value of 26% for the entire remainder of the movement (as in step E61).

[0054] 6 shows three scenarios for carrying out the method according to the invention on the same graph, for three different values of the estimated transit time TBC when detecting a road sign at time t0, each of these values falling within a different range. Each curve I1, I2 and I3 represents the time period in which the motor vehicle 1 is moving through the area Z C 32 basic light sources selected within i,j where the abscissa represents the luminous intensity (as a % of the nominal luminous intensity) emitted by the lamp, and the abscissa represents time. Specifically, curve I1 is obtained by rule L1, curve I2 by rule L2, and curve I3 by rule L3.

[0055] Therefore, it can be seen that these luminous intensities decrease from the time point t0 when the road sign 10 is detected until the time point t0' when the remaining time ttc falls below the threshold value TS min and then take a constant value of 26%. If the time t1 is reached (therefore, the value ttc reaches 0 and the light sign 10 has been passed), each luminous intensity can return to the nominal value of 100%.

[0056] Also, by using the rules L1, L2, and L3, it can also be seen that the earlier the road sign 10 is detected, the slower the decrease in the luminous intensity emitted within the area Z C becomes. Thus, optimal illumination of the road sign 10 when the motor vehicle 1 is moving can be ensured, thereby enabling the driver and the camera 21 to continuously perceive and recognize the road sign throughout this movement, and moreover, making it possible without generating specular reflection that would be misleading.

[0057] The remaining basic light source 32 i,j should be noted that it can perform a non-misleading road lighting function by dimming or turning off the basic light source 32 that can particularly mislead the drivers of oncoming or preceding target motor vehicles i,j .

[0058] The above description clearly explains how the present invention can achieve its set goals. In particular, it proposes a method for controlling the vehicle's lighting system that optimizes the perception and understanding of road signs by the vehicle's driver and camera during vehicle movement, and moreover, enables this without any risk of the sign generating misleading specular reflection.

[0059] In any case, the present invention should not be regarded as being limited to the embodiments specifically described in this document, but rather extends in particular to any equivalent means and any technically effective combination of these means. In particular, it is possible to envisage a light module other than the described type, in particular a light module comprising a combination of a matrix of selectively actuable micromirrors and a light source. It is also possible to envisage estimating the distance separating a road sign from a motor vehicle, for example using Bouguer's law from the illuminance of the road sign measured by a sensor system. It is also possible to envisage many control rules different from those described, and / or many function profiles different from those described in these rules.

Claims

1. A lighting system (3) for a motor vehicle (1), each of which has a fundamental light beam (HD ｉ，ｊ a plurality of elementary light sources (32) selectively controllable to emit ｉ，ｊ ) wherein said elementary light beams together form a pixelated light beam (HD), a. detecting (E1) a road sign (10) by a sensor system (2) of the motor vehicle; b. The time when the road sign is detected (t ０ ) and a future time (t １ (E2) estimating the transit time (TBC) between c. A step of controlling (E61, E63) the elementary light sources of the lighting system of the host vehicle to emit a pixelated light beam, wherein areas of lower luminosity (Z) are present in the light beam extending in the vicinity of the road sign. Ｃ controlling some of the fundamental light sources in response to the transit time to produce a d) a step (E62) of selecting one control rule (L i ) from a plurality of control rules (L 1 , L 2 , L 3 ) depending on the value of the transit time (TBC), A method in which each control rule defines the progression of the luminous intensity (I) to be emitted as an increasing function of time, each control rule (L i ) in the plurality of control rules (L 1 , L 2 , L 3 ) being associated with at least one distinct transit time (TS min , TS 1 , TS 2 ), the increasing function of each control rule having an increasing rate, and for a first control rule associated with a transit time longer than the transit time associated with a second control rule, the increasing rate of the increasing function of the first control rule is lower than the increasing rate of the increasing function of the second control rule.

2. 2. The control method according to claim 1, wherein during the detection step (E1), (E11) the sensor system (2) estimates the distance (d) separating the motor vehicle (1) from the road sign (10), and during the transit time estimation step (E2), the transit time (TBC) is estimated depending on the distance and the speed (v) of the motor vehicle.

3. 2. The control method according to claim 1, wherein during the detection step (E1), (E11) the sensor system (2) measures the illuminance (E) of the road sign (10) by the lighting system (3), and during the step (E2) of estimating the transit time (TBC), a distance (d) separating the motor vehicle (1) from the road sign (10) is estimated depending on the measured illuminance and the light intensity (I) emitted by the lighting system towards the sign, and during the step of estimating the transit time, the transit time is estimated depending on the distance and the speed (v) of the motor vehicle.

4. The level of dazzlement (Y) of the driver of the motor vehicle (1) due to the road sign is estimated, and this dazzlement level is calculated based on a given dazzle threshold (TS Ｙ ), and in the light beam (HD) there is provided a step (E12) of comparing the area (Z Ｃ ) to generate a basic light source (32 ｉ，ｊ 4. The method according to claim 1, wherein the steps (E61, E63) of controlling the level of dazzlement (E62) are conditioned on the fact that the dazzle level is higher than the given dazzle threshold.

5. The transit time (TBC) is set to the minimum threshold (TS min ), and if the transit time is shorter than the shortest threshold, ｉ，ｊ During the step (E61) of controlling the area of ​​lower light intensity (Z Ｃ Each of the elementary light sources of the part intended to generate an elementary light beam (HD) with a constant luminous intensity (I) when the motor vehicle (1) moves towards the road sign (10). ｉ，ｊ 5. The method of claim 1, wherein the release of the active ingredient is controlled to release a compound selected from the group consisting of hydroxybenzoates, ...

6. The transit time (TBC) is set to the minimum threshold (TS min ), and if the transit time is longer than the shortest threshold, ｉ，ｊ During the step (E63) of controlling the area of ​​lower light intensity (Z Ｃ Each of the elementary light sources of the part intended to generate an elementary light beam (HD) of decreasing luminous intensity (I) as the motor vehicle (1) moves towards the road sign (10). ｉ，ｊ 6. The method of claim 1, wherein the release of the active ingredient is controlled to release a compound selected from the group consisting of hydroxybenzoates, ...

7. The area of ​​low light intensity (Z Ｃ Each elementary light source (32) of said part is intended to generate ｉ，ｊ ) is a basic light beam (HD) having a luminance determined according to the value of the remaining time (TTC) until the motor vehicle passes the road sign, according to the selected control rule. ｉ，ｊ 7. The method of claim 6, wherein the release of the compound is controlled.

8. Each control rule (L １ , L ２ , L ３ ) is a power function of time (ttc), and the exponent of that power function (β １ , β ２ , β ３ ) is the transit time (TS) associated with this control law. ｍｉｎ , T.S. １ , T.S. ２ 10. The method of claim 1, wherein the method is associated with

9. A motor vehicle (1) comprising a sensor system (2), a lighting system (3) and a controller (4), said controller being configured to perform the method according to any one of claims 1 to 8.

Images