Method and device for controlling an on-board lighting system in a vehicle based on the acceleration of the boundaries of a detected object

Abstract

The present invention relates to a method for controlling an on-board lighting system in a vehicle emitting a light beam, the method comprising: detecting (21) at least three pairs of boundary positions for an object in an illumination field of the light beam; calculating (22) at least two pairs of relative travel speeds for the boundaries of the object in relation to the vehicle based on the pairs of detected positions (21); calculating (23) a pair of accelerations for the boundaries of the object based on at least two of the speed pairs obtained (23); calculating (24) a pair of boundary positions for a shadow area in the illumination field based on one of the pairs of boundary positions of the object; and controlling (25) the lighting system to form a shadow area within the light beam delimited by the boundary positions of the shadow area.

Description

DESCRIPTION Title: Method and device for controlling a vehicle's on-board lighting system based on the acceleration of the limits of a detected object. technical field

[0001] The present invention claims priority from French application 2300777 filed on January 27, 2023, the content of which (text, drawings, and claims) is incorporated herein by reference. The present invention relates to methods and devices for controlling a lighting system in a vehicle, for example, in a motor vehicle. Technological background

[0002] Some modern vehicles are equipped with one or more sensors configured to detect objects in the vehicle's surroundings. Such sensors can, for example, detect the presence of a second vehicle in the vicinity of a first vehicle and transmit this information to an onboard computer in the first vehicle to control its lighting system. The computer can then adjust certain parameters of the lighting system based on the detected information about the second vehicle's position, for example, by reducing the intensity of the first vehicle's headlights in the direction of the second vehicle. This reduction in light intensity is intended to prevent dazzling the driver of the second vehicle.

[0003] There are several families of sensors that can be fitted to these vehicles, for example optical sensors of the camera type or radar-type sensors using radio waves.

[0004] Modern vehicles are very often equipped with headlights capable of combining illuminated and shaded areas. Their level of precision is variable, ranging from simple control of switching headlights such as high beams on or off, to more complex control of switching on segments of matrix headlights.

[0005] The effectiveness of the lighting system control therefore depends on the proper processing of information from the sensor(s) of the first vehicle and the accuracy of headlight control. Summary of the present invention

[0006] One object of the present invention is to solve at least one of the problems of the technological background described above.

[0007] Another object of the present invention is to improve the control of the lighting system in a vehicle.

[0008] Another object of the present invention is to improve road safety.

[0009] According to a first aspect, the invention relates to a method for controlling a lighting system on board a vehicle emitting a light beam, the method comprising the following steps: - detection of at least three pairs of boundary positions of an object in an illumination field of the emitted light beam, each pair of boundary positions of the object comprising a first position of a first boundary of the object and a second position of a second boundary of the object detected at the same time instant, the at least three pairs of boundary positions of the object corresponding to different time instants; - calculation of at least two pairs of relative displacement velocities of the first and second limit of the object with respect to the vehicle from at least three of the detected position pairs of the object and from at least two durations (At) separating the at least three detected position pairs of the object; - calculation of a pair of accelerations of the first and second limit of the object from at least two of the velocity pairs obtained of the object with respect to the vehicle and from at least two durations separating the at least three pairs of positions obtained of the object; - calculation of a pair of boundary positions of a shadow zone in the lighting field as a function of one of the pairs of boundary positions of the object, as a function of one of the pairs of relative displacement velocities of the object's boundaries, as a function of the pair of relative accelerations of the object's boundaries, and as a function of a latency time between the start of the detection of at least three pairs of boundary positions of the object and the end of the lighting system control; and - control of the lighting system to form a shadow zone inside the light beam delimited by the calculated pair of boundary positions of the shadow zone.

[0010] The process makes it possible to calculate a shadow zone around a detected object and to control the vehicle's lighting system to avoid dazzling any users present in the area of ​​the detected object.

[0011] Taking into account the relative speed of the object makes it possible to limit the shadow area so as to maintain, for the driver of the vehicle, a larger illuminated area than that illuminated by current anti-glare systems, which improves road safety because the driver has a better view of the road environment close to the vehicle he is driving.

[0012] Taking into account the relative acceleration of the object, in addition to the relative speed of the object, makes it possible to improve the prediction of the object's position and to adjust the positioning of the shadow area around the object, especially when the object rapidly changes direction of movement relative to the vehicle.

[0013] According to one variant, the said pair of boundary positions of a shadow zone is calculated from a pair of margins.

[0014] According to one variant, the margins of the pair of margins are proportional to the velocities of one of the at least two pairs of relative displacement velocities.

[0015] According to one variant, the margins of the margin pair are related to the velocities of one of the at least two velocity pairs by piecewise affine functions.

[0016] According to one variant, the margins of the pair of margins are polynomial functions of the velocities of at least one of the two pairs of relative displacement velocities.

[0017] According to one variant, the margins of the margin pair are proportional to the accelerations of at least one pair of relative accelerations of the object's boundaries.

[0018] According to one variant, the pair of boundary positions of the shadow zone is further calculated as a function of a vehicle rotation speed and / or a vehicle acceleration.

[0019] Taking into account the rotation speed and / or the acceleration of the vehicle's rotation makes it possible to increase the accuracy of defining the positions of the limits of the shadow zone.

[0020] According to a second aspect, the present invention relates to a control device for a lighting system on board a vehicle emitting a light beam, the device comprising a memory associated with at least one processor configured for the implementation of the steps of the process according to the first aspect of the present invention.

[0021] According to one variant, the device includes: - a sensor configured for the implementation of the detection step; - at least one computer configured to implement the steps of calculating a pair of relative movement velocities of the object and calculating a pair of boundary positions of a shadow zone within a light beam's illumination field; and - a light source configured to produce the shadow area whose boundary positions are calculated by said at least one computer.

[0022] According to a third aspect, the present invention relates to a vehicle, for example of the automobile type, comprising a device according to the second aspect of the present invention.

[0023] According to a fourth aspect, the present invention relates to a computer program which includes instructions adapted for carrying out the steps of the process according to the first aspect of the present invention, in particular when the computer program is executed by at least one processor.

[0024] Such a computer program can use any programming language and be in the form of source code, object code, or an intermediate form between source code and object code, such as in a partially compiled form, or in any other desirable form.

[0025] According to a fifth aspect, the present invention relates to a computer-readable recording medium on which is recorded a computer program comprising instructions for carrying out the steps of the process according to the first aspect of the present invention.

[0026] On the one hand, the recording medium can be any entity or device capable of storing the program. For example, the medium can include a storage means, such as a ROM, a CD-ROM or a microelectronic circuit-type ROM, or a magnetic recording means or a hard drive.

[0027] On the other hand, this recording medium can also be a transmissible medium such as an electrical or optical signal, such a signal being able to be transmitted via an electrical or optical cable, by conventional or radio frequency, by self-directing laser beam, or by other means. The computer program according to the present invention can, in particular, be downloaded from a network such as the Internet.

[0028] Alternatively, the recording medium may be an integrated circuit in which the computer program is incorporated, the integrated circuit being adapted to execute or to be used in the execution of the process in question. Brief description of the figures

[0029] Other features and advantages of the present invention will become apparent from the description of the specific and non-limiting embodiments of the present invention below, with reference to the attached Figures 1 to 5, in which:

[0030] [Fig. 1] schematically illustrates a vehicle environment, according to a particular and non-limiting embodiment of the present invention;

[0031] [Fig. 2] illustrates a flowchart of the different stages of a process for controlling a lighting system on board a vehicle emitting a light beam, according to a particular and non-limiting embodiment of the present invention.

[0032] [Fig. 3] schematically illustrates the environment of a vehicle as seen from that same vehicle, according to a particular and non-limiting embodiment of the present invention;

[0033] [Fig. 4] schematically illustrates a device configured to control an on-board lighting system in a vehicle of figure 1, according to a particular and non-limiting embodiment of the present invention;

[0034] [Fig. 5] illustrates a diagram representing a piecewise affine function according to an example of an embodiment of the present invention. Description of examples of achievements

[0035] A method and device for controlling a vehicle-mounted lighting system emitting a light beam will now be described in what follows with joint reference to Figures 1 to 5. The same elements are identified with the same reference symbols throughout the following description.

[0036] The method includes the detection of at least three pairs of boundary positions of an object in an illumination field of the emitted light beam, each pair of boundary positions of the object comprising a first position of a first boundary of the object and a second position of a second boundary of the object detected at the same time instant, said at least three pairs of boundary positions of the object corresponding to different and successive time instants.

[0037] This object corresponds, for example, to a second vehicle present in the vicinity of the first vehicle.

[0038] From these at least three pairs of positions detected at at least three given times, a vehicle computer will then obtain at least two pairs of relative displacement speeds of the first and second limit of the object at at least two of these different given time instants.

[0039] From these at least two pairs of relative displacement velocities of the first and second limit of the object calculated at two given time instants, a computer in the vehicle will then calculate a pair of accelerations of the first and second limit of the object.

[0040] A computer, which may be the same computer as before but may also be different from it, calculates, from a pair of detected positions and from a pair of relative movement velocities of the same limits of this same object (calculated) and from a pair of accelerations of these same limits of this same object (also calculated), a pair of positions of the limits of a shadow zone in a field of illumination of the emitted light beam.

[0041] Thus, the calculated shadow zone in the field of illumination of the vehicle's light beam helps to avoid dazzling any users present in the area of ​​the detected object.

[0042] Figure 1 schematically illustrates an environment 1 in which a vehicle 10 evolves, according to a particular and non-limiting embodiment of the present invention.

[0043] Such an environment 1 corresponds, for example, to a road environment consisting of a network of roads accessible to vehicle 10.

[0044] In this example, vehicle 10 corresponds to a vehicle with an internal combustion engine, an electric motor(s), or a hybrid vehicle with an internal combustion engine and one or more electric motors. Vehicle 10 thus corresponds, for example, to a land vehicle such as a car, a truck, a bus, or a motorcycle. Finally, vehicle 10 corresponds to an autonomous or non-autonomous vehicle, that is, a vehicle operating at a predetermined level of autonomy or under the full supervision of the driver.

[0045] In this environment 1, there is an object 100. This object 100 can also be a motor vehicle as described previously, but also, for example, a pedestrian, a cyclist or any other type of user.

[0046] According to a first embodiment, object 100 is present in the field of vision 11 of a sensor of a vehicle object detection system 10. Such a sensor can be optical, for example a camera. It can also be of another type, for example a sensor using radio waves, such as radar, or infrared. This sensor can be placed in different locations on the vehicle 10, at the top of the windshield for example, but also on the front bumper, the grille, or in the headlights.

[0047] The object detection system is configured to determine the positions of the 100g and 100d limits of the object 100 detected by the sensor. The 100g and 100d limit positions correspond to the extreme limits of the object 100, thus defining a zone of presence of the object 100 between these two limits.

[0048] The vehicle 10 includes a lighting system that generates a light beam 12. The light beam 12 is emitted, for example, by a single headlight located on the right side of the vehicle 10. The present invention then allows this headlight to be controlled. It is evident that the present invention also allows the control of a lighting system comprising several headlights, each emitting a light beam 12. For example, a second beam 12 is emitted by a second headlight, located on the left side of the vehicle 10.

[0049] In order to avoid dazzling any users present in the area of ​​the detected object, it is then necessary to generate a shadow zone 13 in the light beam 12.

[0050] A shadow zone is defined as an area in which the light intensity of the beam 12 is less intense or even nonexistent. That is to say, the light source illuminating this shadowed area emits less light or even no light at all. Such a shadowed area can correspond to all or part of the light beam 12.

[0051] Indeed, in the case of a lighting system comprising a headlight incorporating a simple halogen bulb, the present invention controls the lighting system of the vehicle 10 by controlling, for example, the switching on or off of this halogen bulb.

[0052] In the case of a lighting system comprising a headlight comprising segments or a matrix formed of elements made with, for example, light-emitting diodes (LEDs) or lasers, the present invention controls the lighting system by reducing, for example, only a part of the elements generating the light beam 12, these segments or matrix elements generating light in a part called the shadow zone 13.

[0053] The light beam 12 of the vehicle 10 then incorporates a shadow zone 13 defined in that the limits 13g, 13d of the shadow zone 13 are determined respectively with respect to the positions 100g, 100d of the object 100 with a certain offset corresponding to a margin. This offset is determined in such a way as to prevent the object 100 from leaving the shadow zone 13, that is to say, from the object 100 entering an illuminated part of the beam 12 and thus from dazzling any road user present in the area of ​​the detected object.

[0054] The light beam emitted by a headlight of vehicle 10 is then composed of two half-beams of light 12G, 12D distributed on either side of the object 100. It should be noted that one of the half-beams 12G, 12D may be non-existent in the case where one of the limits 100g, 100d of the object 100 is close to one of the limits of the light beam 12.

[0055] The example here is limited to describing the detection of a single object 100 by vehicle 10. However, it is possible to detect several objects simultaneously and thus define several shadow zones within the illumination field of the light beam. These shadow zones may be distinct or overlapping depending on the positions of the detected objects. The light beam 12 emitted by vehicle 10 is then composed of a plurality of light sub-beams.

[0056] The positions of the limits 13g, 13d of the shadow zone are calculated via method 2 described in relation to figure 2.

[0057] Figure 2 illustrates the different steps of process 2 for controlling a vehicle-mounted lighting system 10 emitting a light beam 12.

[0058] In a first step 21, three pairs of boundary positions of an object are detected in an illumination field of the light beam 12. One of the pairs of boundary positions (position ioog(t1); position iood(t1)) comprises a first position position ioog(t1) of a first boundary 100g of the object 100 and a second position position iood(t1) of a second boundary 100d of the object 100 detected at the same time instant t1, the pair of boundary positions (position iooo g (t2) position iood(t2)) includes a first position position ioo g (t2) of the first limit 100g of object 100 and a second position position iood(t2) of the second limit 100d of object 100 detected at a time instant t2 and the pair of limit positions (position ioo g (t3); position iood(t3)) includes a first position position ioo g(t3) of the first limit 100g of object 100 and a second position position iood(t3) of the second limit 100d of object 100 detected at a time instant t3.

[0059] The time instants t1, t2 and t3 are different.

[0060] For the following, t1 is defined as prior to t2 and t2 is defined as prior to t3, that is to say that the positions detected at time t3 are the most recently detected positions.

[0061] The positions of the boundaries of object 100 and the positions of the boundaries of the shadow zone 13 can be expressed in a coordinate system defined, for example, by the vehicle's oriented longitudinal axes. For example, the longitudinal axis 31 (Figure 1) is oriented from the rear of the vehicle to the front of the vehicle, meaning that the coordinates along this axis increase from the rear to the front of the vehicle, and the lateral axis 30 is oriented from the left to the right of the vehicle. According to this definition of the coordinate system, position 100 g (t) <positioniood(t).

[0062] Subsequently, the positions of the object's boundaries and the shadow area are expressed in this coordinate system. The present invention is not limited to the definition of this coordinate system but extends to any other definition of a coordinate system that allows the positions of the object's boundaries and the shadow area to be expressed. he

[0063] In a second step 22, two pairs of relative displacement velocities of the first 100g and the second 100d limits of object 100 relative to vehicle 10 are calculated from the three pairs of limit positions of object 100 previously detected and from two durations At separating the detection of the three pairs of detected limit positions of object 100.

[0064] Velocity is the result of dividing a displacement by a time interval At. For example, if the displacement is the distance between two positions positionwg(t1) and positionwg(t2), and if the time interval At is given by t = t2 - t1, then the velocity is velocityi. g (t2) of the first limit 100g of the object 100 at time t2 is given by: velocity ioo g (t2) = (positionioo g (t2)-positionioo g (t1)) / At or by: speed g (t2) = (positionioo g (t2)-positionioo g (t2-At)) / (At).

[0065] Similarly, if At = t3-t2, the velocity is velocityioo g (t3) of the first limit 100g of the object 100 at time t3 is given by: velocity ioo g (t3) = (positionioo g (t3)-positionioo g (t2)) / At or by: speed g (t3) = (positionioo g (t3)-positionioo g (t3-At)) / (At).

[0066] Similarly, the velocities of the second limit 100d of the object 100 at time instants t2 and t3 are given by: velocityiood(t2) = (positioniood(t2)-positioniood(t1 )) / At or by: velocitywod(t2) = (positioniood(t2)-positioniood(t2-At)) / (At) ; velocitywod(t3) = (positioniood(t3)-positioniood(t2)) / At or by: velocitywod(t3) = (positioniood(t3)-positioniood(t3-At)) / (At).

[0067] According to one embodiment of step 22, the duration At is the sensor acquisition period between two pairs of successive limit positions.

[0068] In a third step 23, a pair of relative accelerations of the limits of object 100 with respect to vehicle 10 is calculated from the two pairs of velocities of the limits of object 100 previously calculated and from a time separating the two pairs of velocities of the limits of object 100 calculated.

[0069] Acceleration is the result of dividing a change in velocity by a time interval. For example, if the change in velocity is the difference between the two velocities calculated at times t2 and t3, and if the time interval At is given by At = t3 - t2, then the acceleration w0(t3) of the first limit 100g of the object 100 at time t3 is given by: acceleration w0(t3) g (t3) = (speed ioo g (t3)- speed wo g (t2)) / At or also by: acceleration g (t3) = (speed ioo g (t3)- speed wo g (t3-At)) / (At).

[0070] Similarly, the acceleration of the second limit 100d of the object 100 at time t3 is given by: accelerationiood(t3) = (velocity wod(t3)- velocity wod(t2)) / At or by: accelerationiood(t3) = (velocity wod(t3)- velocity wod(t3-At)) / (At).

[0071] In a fourth step 24, a pair of boundary positions 13g, 13d of the shadow area 13 in the illumination field 12 is calculated as a function of one of the three pairs of boundary positions of the object 100, as a function of one of the two pairs of relative boundary displacement velocities of the object 100, as a function of the acceleration pair and as a function of a latency time.

[0072] Latency time is defined as a duration elapsed between a start of the detection 21 of the at least three pairs of boundary positions of the object 100 and an end of the control 25 of the lighting system.

[0073] For example, the latency time (tempsiatenœ) depends on all or some of the following operations that are required to implement the process: - sensor acquisition; - communication between the sensor and one or more computers of the vehicle used for the implementation of the process, determined for example by the period separating 2 signal frames during communication between sensors, computers and other peripherals used for the implementation of the process and connected, for example, by a communication bus type link; - calculation to define the positions of the limits of the shadow zone; - communication between a computer and an actuator, for example a headlight; - switching on the different light sources, for example LED, neon, halogen or laser type.

[0074] The link between the latency time and the speed of a boundary 100g, 100d of the object 100 allows us to predict the future positions of the boundaries 100g, 100d of the object 100 at a time t1 + time t1, i.e. at the time when the vehicle lighting control system 10 will apply the shadow zone 13 around a future position of the object 100.

[0075] In a fifth step 25, the vehicle lighting system 10 is controlled to form a shadow zone within the light beam 12 delimited by the pair of positions of the limits 13g and 13d of the calculated shadow zone.

[0076] According to one embodiment of step 24, the pair of positions of the limits 13g, 13d of the shadow zone 13 is calculated from a pair of margins (margin g (margined) themselves calculated from one of the two pairs of relative displacement velocities of the object's limits 100 and from the pair of accelerations, by: positioni3g = position ioog (t3) + margin g position 13d = position iood(t3) + marging.

[0077] The margin values, margeg, marged, are calculated based on all or part of the following parameters, hereinafter referred to as 'input parameters': - Sensor accuracy; mounting accuracy and adjustment quality of sensors and actuators - the resolution and precision of the light beam (which can vary considerably from a simple halogen bulb to a projector with several million pixels, including headlights with a few segments); - latency time; - the time between two successive calculations of the positions of the limits 13g, 13d, called the refresh time. - limit positions 100g, 100d of object 100 (position ioog(t3) ; position ioog(t3)); - relative movement speeds of limits 100g, 100d with respect to vehicle 10 calculated during step 22 (velocitywod(t3); velocitywod(t3)); - relative accelerations of the limits 100g, 100d with respect to vehicle 10 calculated during step 23 (accelerationiood(t3); accelerationiood(t3)); and - at least one adjustment constant defined in particular during tests under real conditions;

[0078] According to a variant of step 24, the margins incorporate a constant part, hereafter called the static margin. s tactic, which is calculated based on some of the following input parameters: - the accuracy of the sensor; - the resolution and precision of the light beam.

[0079] According to another variant of step 24, the margins are proportional to the speeds of one of the two pairs of relative movement speeds of the limits of object 100 with respect to vehicle 10.

[0080] The margins are each, for example, the image of an affine function of the relative speed of movement of one of the limits of the object 100 with respect to the vehicle 10.

[0081] According to a variant of step 24, the margins are proportional to the accelerations of the torque of relative travel speeds of the limits of object 100 with respect to vehicle 10.

[0082] By combining several of these variants, we obtain margins given by: margin g = - a + b*velocity g (t3) + c*acceleration g (t3) ; marged = a + b*vitesseiood(t3) + c*accrocessioniood(t3) ; with a>0, b>0 and c>0.

[0083] The constant 'a' includes, for example, the static margin defined previously.

[0084] The coefficient 'b' is defined using the previously defined input parameters, including: - latency time; and - the cooling time.

[0085] The coefficient 'c' is defined using the previously defined input parameters, such as: - latency time; and - the cooling time.

[0086] Thus, the respective positions of the limits 13g, 13d of the shadow zone 13 are given by: positioni3g = position ioo g (t3) + margin g , that is: positioni3g = position ioo g (t3) - margin s tatique - a + b*vitesseioo g (t3) + c*acceleration g (t3) position 13d = position iood(t3) - margeg, i.e.: positioned = position ioog(t3) + margestatic + a + b*vitesseioog(t3) + c*accelerationioog(t3).

[0087] The goal is to accurately predict the object's probable future position (or an envelope of probable positions), after the system's latency time, and to adapt the shadow area accordingly.

[0088] The acceleration component allows us to adjust the probable future position of the object (or an envelope of probable positions) when the acceleration of the object's boundary is non-zero, that is, when its velocity is not constant.

[0089] If, for example, the speed is constant, the future positions of the boundaries of object 100 at the end of the latency time are determined by: position ioo g (t1 + time) = position 1 oo g (t1) + time lag x velocity ioog(t3); and

[0090] position ioog(t1 + tempsiatence) = position ioog(t1) + tempsiatence x vitesseioog(t3) .

[0091] It is advantageous to reduce the margin between the position of a boundary 13g or 13d of the shadow zone 13 and the position of a boundary 100g or 100d of the object 100 in order to reduce the shadow zone 13. Both margins can also be reduced depending on the direction of movement of the boundaries of the object 100. Indeed, the vehicle 10 loses lighting performance due to the projection of the excessively wide shadow zone into the light beam 12, thus reducing the driver's perception of the environment.

[0092] Conversely, it is necessary to define a sufficiently large shadow zone around the detected object 100 in order to ensure that the object 100 will not leave this shadow zone between two successive calculations of the positions of the limits of the shadow zone.

[0093] If speed g (t3) < 0, we say that the 100g limit of object 100 is approaching. Conversely, if velocity ioo g(t3) > 0, we say that the 100g limit of the object 100 is moving away.

[0094] Similarly, if `viteiood(t2)` > 0, we say that the limit 100d of object 100 is approaching. Conversely, if `viteiood(t2)` < 0, we say that the limit 100d of object 100 is moving away.

[0095] When the 100g limit of object 100 is approached, i.e., speed ioo g (t3) <O, et que l’accélération de la limite 100g de l’objet 100 est nulle, alors : | marge g (approach) | = | a | + | b*vitesseioog(t3)\. When the 100g limit of object 100 moves away, i.e., velocity i0o g (t3)>O, and that the acceleration of the limit 100d of object 100 is zero, then: | margin g (distance) | = | | a | - 1 b*vitesseioog(t3)\ |. Thus: | margin g (approach) | > | margin g (distance) |

[0096] Similarly for the limit 100d of object 100, we obtain: | margined(approach) | > | margined(remote) |.

[0097] Thus, the calculated margin between the position of a boundary of object 100 and the position of the associated boundary of the shadow zone 13 is smaller when this boundary is moving away than when it is approaching. In other words, the width of the shadow zone is reduced near a boundary of object 100 that is moving away compared to the width of a shadow zone near a boundary of object 100 that is approaching, for a given absolute speed.

[0098] According to another variant of step 23, the constant 'a', the coefficient 'b' and the coefficient 'c' can be different depending on ranges of values ​​of the velocity ioo g (t3) and velocityiood(t3).

[0099] A threshold £ is, for example, defined.

[0100] By combining this variant with the previous variant, we obtain, for example, a treatment using discriminating affine functions, also called piecewise affine functions: If speed ioo g (t3) < -£, then: margin g = - margin s tactics - a1 + b1*speed g (t3) + c1 *accelerationioo g (t3); If -£ < velocity ioo g (t3) < £, then: margin g = - static margin - a2 + b2*velocity g (t3)+ c2*accelerationioog(t3) ; If £ < velocity ioo g (t3), then: margin g = - margin s tactics - a3 + b3*speed g (t3) + c3*accelerationioo g (t3); If velocity iood(t3) < -£, then: marged = margestatic + a3 + b3*velocityiood(t3) + c3*accelerationiood(t3); If -Σ < velocity iood(t3) < s, then: marginq = static margin + a2 + b2*velocityiood(t3) + c2*accelerationiood(t3); and if Σ < velocity iood(t3), then: marginq = static margin + a1 + b1*velocityiood(t3) + c1*accelerationiood(t3). The constants 'a1', 'a2', and 'a3', the coefficients 'b1', 'b2', and 'b3', and the coefficients 'c1', 'c2', and 'c3' are defined using the previously defined input parameters.

[0101] This particular example of a piecewise affine function is described using Figure 5.

[0102] In one variant, the coefficients 'c1', 'c2' and 'c3' are equal. Only the velocity is then treated using a piecewise affine function.

[0103] According to another variant, the constants 'a1', 'a2' and 'a3', the coefficients 'b1', 'b2' and 'b3', as well as the threshold values ​​-£ and £ are defined as a function of the acceleration of the relative displacement of one of the limits of object 100. In this way, it is possible to reduce the width of the range {-£ ;£} in the case where the acceleration of one of the limits of object 100 is close to 0, or even to remove the range {-£ ;£} if £=0 when the relative acceleration of one of the limits of object 100 is zero.

[0104] According to another variant, the pair of boundary positions of the shadow zone 13 is further calculated as a function of a polynomial of degree two or higher of the velocity of one of the boundaries of the object 100.

[0105] According to a variant of step 24, the pair of boundary positions of the shadow zone 13 are further calculated as a function of a pivoting speed and a pivoting acceleration of the vehicle 10.

[0106] This variant is advantageous because, when vehicle 10 pivots, object 100 has its relative position greatly modified, especially if object 100 is far from vehicle 10. Taking into account the pivoting speed can therefore become predominant and have a strong impact on the calculation of the margin couple (margeg, margind).

[0107] Furthermore, some sensors can, for example, communicate a position of a limit 100g, 100d of the object 100 in a frame of reference different from that of the vehicle 10. It is then necessary to transform the data received from such a sensor into relative data with respect to the vehicle 10.

[0108] In an optional step 26, the pivoting speed and / or the pivoting acceleration of vehicle 10 is obtained. This data can be obtained in various ways, such as by measuring the steering wheel position, the wheel angle, or by using an inertial sensor.

[0109] According to one embodiment of the process, a step 24c allows the margin calculation to be corrected as a function of the pivoting speed and / or acceleration of the vehicle 10, either by applying a correction coefficient to the margin calculation for example, or by adding an offset in the form of a constant or one or more variables proportional to the pivoting speed and / or acceleration.

[0110] These embodiments allow for taking into account the pivoting of vehicle 10.

[0111] Thus, taking into account the accelerations of the boundaries of object 100 in the different variants presented makes it possible to anticipate a variation in the speed of the boundaries of vehicle 100, or even a change in the direction of movement of the boundaries of vehicle 100. The boundaries of the shadow zone are then calculated accordingly in order to guarantee a minimum shadow zone width in the beam while avoiding dazzling any user present in the vicinity of the boundaries of object 100.

[0112] In most vehicles, the position of the sensor used to detect the positions of the ends of object 100 and the position of the headlight(s) that produce the light beam(s) are not the same. For example, the most common position for a camera-type sensor is often located at the top and center of the vehicle's windshield. However, the headlights are typically located on either side of the vehicle's bumper or grille. This means that the distance between the sensor and the actuator can be: - 150cm depending on the length of the vehicle, with the camera positioned behind the headlights - 70 to 80cm depending on the width of the vehicle, on one side or the other depending on whether it is the right or left headlight - 70cm in height depending on the height of the vehicle.

[0113] The position pair of the boundary 13g, 13d of the shadow zone 13 can therefore be corrected to compensate for parallax errors due to the relative positions of the actuators (headlights) with respect to the sensor(s). Several correction methods are possible.

[0114] According to a variant of step 24, the pair of positions of the limits 13g, 13d of the shadow zone 13 is corrected, for example by transposing the calculated pair of positions of the limits 13g, 13d of the shadow zone 13 from a camera reference frame for example to a lighthouse reference frame.

[0115] It should be noted that the transposition will not be identical whether it is a left or right headlight.

[0116] This need to transpose positions from one reference frame to another is cited only as an example. It is entirely conceivable to locate, for instance, the sensor at the headlight. This has several advantages, such as increased communication speed between the sensor and the actuator, miniaturization of the system, and improved reliability of the lighting system control, since the entire system is designed as a single subset.

[0117] According to a variant of the process, in the first step 21, more than three pairs of boundary positions of object 100 are detected in the illumination field of the light beam 12 during step 21.

[0118] These pairs of positions correspond to 'n' pairs of boundary positions of object 100 detected at 'n' distinct time instants: (position ioo g (ti); position iood(ti)); ... ; (ioo position g (t n ) ; position iood(t n )). The time elapsed between the detection of each pair of positions is At, thus the time separating the first detection at time 'ti' and the last detection at time t n is: (n-1) x At.

[0119] In the second step 22, a plurality (n-1) of pairs of relative displacement velocities of the limits of object 100 with respect to vehicle 10 is calculated from the 'n' pairs of positions of the limits of object 100 previously detected and from durations separating the 'n' pairs of detected positions of the limits of object 100.

[0120] Thus, for 1 < t < n: speed ioog(t) = (position ioog(t)-positionioog(t- At)) / At; speed iood(t) = (position 1 ood(t)-position 1 ood(t-At)) / (At).

[0121] In the third step 23, a plurality (n-2) of pairs of relative accelerations of the limits of object 100 with respect to vehicle 10 is calculated from the 'n-1' pairs of velocities of the limits of object 100 previously calculated and from durations separating the 'n-1' pairs of detected positions of the limits of object 100.

[0122] Thus, for 2 < t < n: acceleration ioog(t) = (velocityioog(t)-velocityioo g (t-At)) / At ; acceleration wod(t) = (speediood(t)-speediood(t-At)) / (At).

[0123] In step 24, a single pair of margins (margin g (margin) is calculated to define a pair of boundary positions 13g, 13d of the shadow zone 13. Position 13g = position 13g + margin g position 13d = position iood + margined.

[0124] According to embodiments of step 24, positions 100 g, 100d of the object can be equal to the boundary positions of the object at a time t (with 1 <t<n) ou encore à des valeurs moyennes de positions de limites de l’objet sur une durée de détection donnée, par exemple égale à la durée totale de détection (entre t1 et tn) : position ioog = moyenneu ^(position ioog(t)) ; et positioniood = moyennes tn(positioniood(t)).

[0125] According to embodiments of step 24, the speeds speed g The velocity of the object's boundaries can be equal to the boundary velocities of the object at a time t (with 1 <t<n) ou encore à des valeurs moyennes de vitesses de limites de l’objet sur une durée de détection donnée, par exemple égale à la durée totale de détection (entre t1 et tn) : velocity-ioog = averaget2->tn(velocityioo g (t)); and velocity-iood = meant2^tn(velocityiood(t)).

[0126] According to embodiments of step 24, the accelerations accelerationwog, acceleration-iood of the object's boundaries can be equal to the object's boundary accelerations at time t (with 2 <t<n) ou encore à des valeurs moyennes d’accélérations de limites de l’objet sur une durée de détection donnée, par exemple égale à la durée totale de détection (entre t1 et tn) : accélération 100g = moyennet3^tn(accélérationioo g (t)); and acceleration iood = meant3->tn(accelerationiood(t)).

[0127] According to variant embodiments of step 24, the margin values g Margins are calculated based on all or part of the 'input parameters', to which are added: - the 'n' pairs of limit positions 100g, 100d of object 100 detected during step 21; - the 'n-1' pairs of relative displacement velocities of the limits 100g, 100d of object 100 with respect to vehicle 10 calculated during step 22 - the 'n-2' pairs of relative accelerations of the limits 100g, 100d of the object 100 with respect to the vehicle 10 calculated during step 23.

[0128] The advantage of using more than three pairs of boundary positions for object 100 is that it allows for refining the calculations performed at different stages. This makes it possible to use average values ​​or eliminate outliers, thus increasing the reliability of the process.

[0129] Figure 3 schematically illustrates the environment of vehicle 10 as seen from that same vehicle.

[0130] In this particular and non-limiting example, object 100 is present in the field of vision 11 of the sensor of vehicle 10. The sensor can be, for example, a camera.

[0131] The positions of the limits 100g, 100d of object 100 correspond to the extreme limits of object 100, determined during detection step 21. In this particular example and not limiting, these positions can be defined in cylindrical coordinates, by an angle 6 and a distance 'd' separating the vehicle 10 from the object 100.

[0132] According to one variant, the coordinates can be defined according to other coordinates, for example by an angle 0 and a value 'd' corresponding to the distance separating the vehicle 10 from a projection of the object 100 on a longitudinal axis 31.

[0133] A lateral axis 30 is defined, as well as a positive direction defined from left to right with respect to the vehicle 10. They correspond for example to the direction in which the angle 0 is measured and its direction of variation.

[0134] The calculation of the velocity torque of object 100 is calculated during step 22. The velocities of the calculated velocity torque are expressed in radians / second for example.

[0135] A velocity value of a limit 100g, 10Od positive translates to a displacement to the right in this example.

[0136] A velocity value of a limit 100g, 10Od positive translates to a movement to the left in this same example.

[0137] Vehicle 10 generates the light beam 12, emitted for example by a headlight of vehicle 10.

[0138] In order to avoid dazzling any users present in the area of ​​the detected object, the present invention generates a shadow zone 13 in the light beam 12.

[0139] The light beam 12 of the vehicle 10 incorporates a shadow zone 13 defined by the present invention in that the limits 13g, 13d of the shadow zone 13 are calculated respectively with respect to the positions 100g, 100d of the object 100 and with respect to the pair of relative movement velocities of the limits 100g, 100d of the object 100 with a certain determined angular offset corresponding to a pair of margins calculated according to a variant. This pair of margins is calculated so as to prevent the object 100 from leaving the shadow zone 13, that is to say, so as to prevent the object 100 from entering an illuminated part of the beam 12, but also to minimize the width of the shadow zone, that is to say, the distance between the limits 13g and 13d, so as to improve the lighting performance and visibility for the driver of the vehicle 10.

[0140] The light beam emitted by a headlight of vehicle 10 is then controlled during step 24. The light beam 12 is then composed of two half-light beams 12G, 12D distributed on either side of the object 100.

[0141] In the case where the two boundaries 100g, 100d of object 100 move to the left at approximately equal speed and acceleration, and the positions of the boundaries 13g, 13d of the shadow zone are calculated according to a variant such that: positioni3g = position ioo g (t3) + margin g = position ioo g (t3) - a + b*vitesseioo g (t3) + c*accelerationioog(t3) position 13d = position iood(t3) - marging = position ioog(t3) + a + b*velocityioog(t3) + c*acceleration ioog(t3), then the width of the shadow area on the left side of object 100 is defined as wider than the width of the shadow area on the right side of object 100.

[0142] On the left side, the risk of dazzling a road user near object 100 is minimized. At the same time, on the right side (which corresponds to the rear of object 100), the shadow area is reduced as much as possible to provide the widest possible beam of light for the comfort and safety of the driver of vehicle 10.

[0143] Thus, a possible user present in the area of ​​the detected object is not dazzled while the driver of vehicle 10 has optimal visibility, the area illuminated by the light beam being calculated as accurately as possible.

[0144] The example here is limited to the description of the detection of a single object 100 by the vehicle 10. However, it is conceivable to detect several objects at once and thus define several shadow areas 13 in the field of illumination of the light beam 12.

[0145] These different shadow zones can be calculated independently for each detected object 100 and then added together to define several shadow zones simultaneously. Thus, each object 100 will be present in a shadow zone, the number of shadow zones being less than or equal to the number of detected objects 100 depending on whether some independently defined shadow zones happen to overlap.

[0146] The driver of vehicle 10 benefits continuously from high-performance lighting, capable of illuminating a large part of his environment while avoiding dazzling other users, all without having to intervene on the control of the vehicle's lighting system.

[0147] Figure 4 schematically illustrates a device 4 configured to control a vehicle's onboard lighting system, according to a particular, non-limiting embodiment of the present invention. The device 4 corresponds, for example, to a device embedded in the vehicle 10, such as a computer or a set of computers.

[0148] Device 4 is, for example, configured to implement the steps of the process described opposite Figure 2. Examples of such a device 4 include, but are not limited to, embedded electronic equipment such as a vehicle's on-board computer, or an electronic control unit such as an ECU (Electronic Control Unit). The elements of device 4, individually or in combination, can be integrated into a single integrated circuit, into several integrated circuits, and / or into discrete components. Device 4 can be implemented as electronic circuits, software (or computer) modules, or a combination of electronic circuits and software modules.

[0149] Device 4 includes one or more processors 40 configured to execute instructions for carrying out the steps of the process and / or for executing instructions from the software embedded in Device 4. The processor 40 may include integrated memory, an input / output interface, and various circuits known to those skilled in the art. Device 4 further includes at least one memory 41, for example, volatile and / or non-volatile memory, and / or includes a memory storage device that may include volatile and / or non-volatile memory, such as EEPROM, ROM, PROM, RAM, DRAM, SRAM, flash, magnetic disk, or optical disk.

[0150] The computer code of the embedded software(s) including the instructions to be loaded and executed by the processor is for example stored on memory 41.

[0151] According to various specific and non-limiting embodiment examples, device 4 is coupled in communication with other similar devices or systems (e.g. other computers) and / or with communication devices, e.g. a TCU (Telematic Control Unit), e.g. via a communication bus or through dedicated input / output ports.

[0152] According to a specific and non-limiting embodiment, device 4 includes a block 42 of interface elements for communicating with external devices. The interface elements of block 42 include one or more of the following interfaces: - radio frequency RF interface, for example of the Wi-Fi® type (according to IEEE 802.11), for example in the 2.4 or 5 GHz frequency bands, or of the Bluetooth® type (according to IEEE 802.15.1), in the 2.4 GHz frequency band, or of the Sigfox type using UBN (Ultra Narrow Band) radio technology, or LoRa in the 868 MHz frequency band, LTE (Long-Term Evolution), LTE-Advanced; - USB interface (from the English "Universal Serial Bus" or "Universal Serial Bus" in French); HDMI interface (from the English "High Definition Multimedia Interface", or "High Definition Multimedia Interface" in French); - LIN interface (from the English "Local Interconnect Network", or in French "Réseau interconnecté local").

[0153] According to another specific and non-limiting embodiment, the device 2 includes a communication interface 43 that enables communication with other devices (such as other computers in the embedded system) via a communication channel 430. The communication interface 43 corresponds, for example, to a transmitter configured to transmit and receive information and / or data via the communication channel 430. The communication interface 43 corresponds, for example, to a wired CAN (Controller Area Network) or CAN FD (Controller Area Network) type network. Flexible Data-Rate » or in French « Flexible Data Rate Controller Network »), FlexRay (standardized by ISO 17458) or Ethernet (standardized by ISO / IEC 802-3).

[0154] According to a particular and non-limiting embodiment, the device 4 can provide output signals to one or more external devices, such as a display screen 440, touch or not, one or more loudspeakers 450 and / or other peripherals 460 (projection system) via the output interfaces 44, 45, 46 respectively. According to a variant, one or more of the external devices is integrated into the device 4.

[0155] Figure 5 illustrates a diagram representing a piecewise linear function according to an embodiment of the present invention. The abscissas correspond, for example, to the angular velocity of the limit 100d of the object 100. The ordinates correspond to the contribution of the velocity of the limit 100d in the margin calculation.

[0156] In this example, we consider that the acceleration of the limit 100d of object 100 is zero.

[0157] A first segment 53 of the affine function is defined by: velocity iood(t) < -s and (velocityiood(t)) = a3 + b3*velocityiood(t2). Thus, according to one of the variants described previously, when calculating the margin we obtain: If velocity iood(t) < -£, then margind = margin s tatique + a3 + b3*vitesseiood(t);

[0158] A second piece 52 of the affine function is defined by: -£ < speediood(t) < £ and (speediood(t)) = a2 + b2*speediood(t). Thus, when calculating the margin, we obtain: If -£ < velocity iood(t) £, then margind = static margin + a2 + b2*velocityiood(t).

[0159] A third piece 52 of the affine function is defined by: £ < speed iood(t) and (speediood(t)) = a1 + b1*speediood(t). Thus, when calculating the margin, we obtain: If £ < velocity iood(t), then, margind = static margin + a1 + b1*velocityiood(t).

[0160] Of course, the present invention is not limited to the embodiments described above but extends to a method for controlling an on-board lighting system Tl in a vehicle (10) emitting a light beam, which would include secondary steps without falling outside the scope of the present invention. The same would apply to a device configured for implementing such a method.

[0161] The present invention also relates to a vehicle, for example an automobile or more generally an autonomous land-powered vehicle, comprising the device 4 of figure 4.

Claims

CLAIMS 1. Method for controlling an on-board lighting system in a vehicle (10) emitting a light beam, said method comprising the following steps: - detection (21) of at least three pairs of limit positions of an object (100) in an illumination field (12) of said emitted light beam, each pair of limit positions of said object (100) comprising a first position of a first limit of said object (100) and a second position of a second limit of said object (100) detected at the same time instant, said at least three pairs of limit positions of said object (100) corresponding to different time instants; - calculation (22) of at least two pairs of relative displacement speeds of the first and second limits of said object (100) relative to said vehicle (10) from at least three of said pairs of detected positions (21) of said object (100) and from at least two durations (At) separating said at least three pairs of detected positions of said object (100); - calculation (23) of a pair of accelerations of the first and second limits of said object (100) from at least two of said pairs of speeds obtained (22) of said object (100) relative to the vehicle (10), from at least two durations separating said at least three pairs of positions obtained from said object (100); - calculation (24) of a pair of limit positions of a shadow zone (13) in said lighting field (12) as a function of one of said pairs of limit positions of said object (100), as a function of one of said pairs of relative displacement speeds of the limits of said object (100), as a function of said pair of relative accelerations of the limits of said object (100) and as a function of a latency time between a start of the detection (21) of said at least three pairs of limit positions of said object (100) and an end of the control (25) of said lighting system; and - control (25) of said lighting system to form a shadow zone (13) inside the light beam (12) delimited by said calculated pair of shadow zone limit positions (13).

2. Method according to claim 1 wherein said pair of limit positions of a shadow zone (13) is calculated from a pair of margins.

3. Method according to claim 2, in which the margins of the pair of margins are proportional to the speeds of one of said at least two pairs of relative displacement speeds.

4. Method according to claim 3, in which the margins of said pair of margins are linked to the speeds of one of said at least two pairs of speeds by piecewise affine functions.

5. Method according to claim 2 or 3, in which the margins of the pair of margins are proportional to the accelerations of said at least one pair of relative accelerations of the limits of said object (100).

6. Method according to one of claims 1 to 5, wherein said pair of limit positions of the shadow zone is further calculated as a function of a pivoting speed of said vehicle (10) and / or an acceleration of the pivoting of said vehicle (10).

7. Computer program comprising instructions for implementing the method according to any one of the preceding claims, when these instructions are executed by a processor.

8. Device (4) for controlling a lighting system on board a vehicle emitting a light beam, said device (4) comprising a memory (41) associated with at least one processor (40) configured for implementing the steps of the method according to any one of claims 1 to 6.

9. Device according to claim 8, comprising: - a sensor configured for implementing the detection step (21); - at least one calculator configured for implementing the steps of calculating (22) two pairs of relative displacement speeds of the limits of said object (100), calculating (23) a pair of relative accelerations of the limits of the object (100) and calculating (24) a pair of limit positions of a shadow zone (13) in a lighting field of said light beam; and - a light source configured to produce said shadow zone of which said pair of limit positions is calculated by said at least one calculator.

10. Vehicle (10) comprising a device (4) according to claim 8 or 9.

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