WO2020120210A1

WO2020120210A1 - Light module for motor vehicle

Info

Publication number: WO2020120210A1
Application number: PCT/EP2019/083358
Authority: WO
Inventors: Kostadin BEEV; Pierre Albou; Hui Jin; Gregory Planche
Original assignee: Valeo Vision
Priority date: 2018-12-12
Filing date: 2019-12-02
Publication date: 2020-06-18
Also published as: FR3090073A1; FR3090073B1

Abstract

The invention relates to a light module (1) for a motor vehicle (10) capable of emitting a light beam, characterized in that it comprises at least one source of infrared light (2) designed to emit infrared light rays and light rays in the visible spectrum which participate in forming said light beam to perform a rear-tail-light function, said source of infrared light (2) emitting at least 50% of its radiant flux between 700 nm and 1100 nm and at least 0.1% of its radiant flux between 600 nm and 700 nm.

Description

Title of the invention: Vehicle light module

automobile

[1] The invention relates to a light module for a motor vehicle. The invention also relates to a driving assistance system comprising such a light module, and to a driving assistance method using such a light module.

[2] With the development of the autonomous motor vehicle, it becomes necessary to improve driving assistance, in all lighting conditions, in particular to manage various specific driving functions including:

- keeping on a lane, also known by the Anglo-Saxon designation "lane keeping", to allow a vehicle to follow its lane on a road, in particular by detecting and signaling to the driver any deviation from

trajectory;

- centering on a lane, also known by the Anglo-Saxon designation "lane centering", which complements the previous function, and more precisely allows the vehicle to be kept autonomously in the center of its lane,

- lane change, also known by the English name "lane changing", to allow a vehicle to change lanes, for example with a view to overtaking,

- emergency braking, also known by the Anglo-Saxon designation "automating emergency breaking", or more simply by the acronym AEB,

- the emergency avoidance maneuver, also known by the English designation "automating emergency steering", or more simply by the acronym AES, which makes it possible to avoid an obstacle present on its lane,

- parking assistance, and autonomous parking.

[3] In these various functions, the assistance system needs to receive input information, including in particular the detection of markings on the ground, such as the lines delimiting the lanes, and / or the presence of any obstacles on the road.

[4] A detection system can in particular detect the information necessary for the assistance system as input information. However, it sometimes happens that the external luminosity is not sufficiently strong for the detection system to be able to detect this information, in particular at night.

[5] It is therefore necessary to have a light module to illuminate

the environment of the vehicle so that there is sufficient light for the detection system to detect the necessary information.

[6] Note, the existing lighting on a vehicle can illuminate the road

in front of the vehicle from a distance of two meters on its own lane and five meters on adjacent lanes. In addition, the regulations impose restrictive limits on the rear lights, which must not exceed certain low thresholds and must be kept within a precise color range. These constraints make it difficult, if not impossible, today to be able to detect certain markings on the ground or obstacles near a vehicle, in particular in the rear region of the vehicle, with the lighting and / or signaling modules. existing. Thus, this does not make it possible to offer an assistance system fulfilling the abovementioned functions necessary for a vehicle comprising a driving assistance system.

[7] The object of the invention is to provide a light module remedying the

above drawbacks, in particular making it possible to illuminate the region situated at the rear of the vehicle while complying with the regulations in force, and to provide a system equipped with such a light module and a driving assistance method using such a light module making it possible to fulfill the assistance functions explained above.

[8] In addition, the object of the invention is to provide a lighting solution

rear and assistance in driving a simple motor vehicle, without excessive and reliable additional cost.

[9] The present invention relates to a light module of a motor vehicle capable of emitting a light beam characterized in that it comprises at least an infrared light source designed to emit infrared light rays and light rays in the visible region participating in the formation of said light beam, said light source emitting at least 50% of its energy flux between 650 nm and 1100 nm, preferably between 700 nm and 1100 nm.

[10] In one embodiment, the infrared light source emits at least 0.1% of its energy flux between 600 nm and 780 nm, preferably between 600 nm and 700 nm.

[1 1] In one embodiment, said infrared light source is arranged so that a main axis of emission of the light beam is inclined towards a horizontal plane of the ground on which rests said vehicle when said light module is mounted on the vehicle.

[12] In one embodiment, the light module comprises a system

optical system associated with the infrared light source and the optical system and the infrared light source are arranged so that a main axis of emission of the light beam is inclined towards a horizontal plane of the ground on which said vehicle rests when said light module is mounted on the vehicle.

[13] In one embodiment, the infrared light source and / or the

optical system and infrared light source are arranged so that, when the module is mounted on a vehicle, the main emission axis crosses the horizontal plane on which the vehicle rests at a distance between 5 m and 25 m from the rear of said vehicle.

[14] In one embodiment, the light module comprises at least one complementary light source designed to emit a light beam comprising infrared light rays and / or light rays in the visible range.

[15] In one embodiment, the module is included in a rear light of the

vehicle.

[16] In one embodiment, the infrared light source also fulfills the function of rear position light. [17] The invention also relates to a driving assistance system comprising a light module according to the invention.

[18] In one embodiment, the assistance system comprises an image pickup device capable of capturing an image of a region illuminated by at least part of the light beam emitted by the light module.

[19] In one embodiment, the image taking device is capable of picking up at least part of the light emitted between 650 nm and 1100 nm,

preferably between 700 nm and 1100 nm.

[20] The invention also relates to a method of assisting in the driving of a

vehicle, characterized in that it comprises a step of emitting a light beam by a light module according to the invention, and a step of capturing an image of a region illuminated by said light beam.

[21] These objects, characteristics and advantages of the present invention will be explained in detail in the following description of embodiments

individuals made without limitation in relation to the attached figures, among which:

[22] - [Figure 1] schematically shows a light module according to an embodiment of the invention mounted on a vehicle.

[23] - [Figure 2] schematically shows a side view of a vehicle equipped with a light module according to an embodiment of the invention.

[24] To facilitate the description, we will conventionally call the longitudinal direction the direction extending from the rear to the front of a vehicle, that is to say the direction in which a vehicle moves in motion. before. This direction is illustrated by an arrow A in Figures 1 and 2 and is included in a horizontal plane, parallel to the plane on which the vehicle rests.

[25] An example of a motor vehicle 10 equipped with a light module 1 is described below with reference to FIGS. 1 and 2. The vehicle 10 is equipped with a light module 1 according to an embodiment of the invention which allows both to illuminate a rear region of the vehicle 10 and to fulfill a rear position light function. [26] The light module 1 comprises an infrared light source 2 designed to emit infrared light rays and light rays in the visible range. These light rays participate in the formation of a light beam 3 emitted by the light module 1 along a main emission axis 4.

[27] This light beam 3 is substantially included in a conical volume of axis the main emission axis 4.

[28] A light beam must be understood as a set of rays

all from the light module. The main emission axis 4 is an axis on which the light intensity of the beam is strongest. As mentioned previously, all the light rays of the light beam 3 are

substantially included in a conically shaped volume formed around the main emission axis 4.

[29] The light module 1 comprises an optical system. The optical system and the infrared light source 2 are arranged so that the light beam emitted by the light module 1 is directed towards the rear of the vehicle.

[30] The energy flux of the infrared light source 2 Fsource is equal to the sum of the spectral densities of energy flux P emitted by the infrared light source 2 for each wavelength.

[31] The value of the energy flux of infrared light source 2 is given by the Math equation. 1.

[32] [Math. 1]

[33] F _sourC e = / ₀ ^{+ ¥} P WdÀ

[34] Where Fsource is expressed in Watt, P in Watt / nm and l in nm.

[35] The infrared light source 2 emits at least 50% of its flux

energy between 650 nm and 1100 nm according to the Math equation. 2.

Preferably, the light source 2 emits at least 50% of its energy flux between 700 nm and 1100nm.

[36] [Math. 2]

[38] Preferably, the infrared light source 2 also emits light rays in the visible range.

[39] For example, the infrared light source 2 emits at least 0.1% of its energy flux between 600 nm and 780 nm, preferably between 600 nm and 700 nm.

[40] The advantage of such a light source is that it can participate in the emission of a light beam performing a rear position light function while providing sufficient light for a detector, such as a device for picking up 'images, so that it can take an image of the area illuminated by the light beam.

[41] In fact, the infrared light source 2 makes it possible to participate in the emission of a light beam 3 which is visible to the human eye without however having too high a light intensity which would be greater than a maximum imposed light intensity. by regulation.

[42] And, the infrared light source 2 also makes it possible to provide a

sufficient light for a detector more sensitive to the emission spectrum of the infrared light source 2 than the human eye, in particular more sensitive to wavelengths greater than 650 nm, thus allowing the region illuminated by the light beam 3 to be sufficiently illuminated for the detector to take an image of this illuminated region.

[43] We can explain the difference in perception of the light emitted by the

infrared light source by the human eye and a detector by the fact that the human eye perceives a visual luminous flux Fvis governed by the Math equation. 3.

[44] [Math. 3]

[46] Where Km is the maximum photopic spectral light efficiency whose

value is constant.

[47] And where V (A) is the photopic relative spectral light efficiency (without

dimensions). V (A) is defined according to standard CIE 1924. It defines the vision of a reference observer in daytime vision. [48] The visual luminous flux thus corresponds to the energy flux emitted by the infrared light source 2, modulated by the function of photopic relative spectral luminous efficiency V (Â) for wavelengths between 380 nm and 780 nm. However, the photopic relative spectral light efficiency function V (A) is weak for the wavelengths between 650 nm and 780 nm. The eye therefore perceives only part of the flux emitted by the infrared light source 2 between 650 nm and 780 nm and it does not perceive the flux emitted from 780 nm.

[49] The detector is chosen to have a higher sensitivity than that of the human eye for wavelengths between 650 nm and 780 nm and / or between 780 nm and 1100 nm. The detector can therefore capture a large part of the energy flow emitted by the infrared light source 2.

[50] Thus, it is advantageously possible with such a source to illuminate a region situated at the rear of the vehicle without exceeding a certain value

intensity, in particular imposed by the regulations while lighting enough to obtain an image of the region located at the rear of the vehicle via an image pickup device sensitive to at least part of the wavelengths between 650 nm and 1100 nm.

[51] The infrared light source 2 then fulfills two functions:

first illuminating function for the detection of the environment or of marking lines in the region located at the rear of the vehicle 10 and a second signaling function such as a position light function, in visible red.

[52] The lighting of the region located at the rear of the vehicle 10 for the realization of the first illuminating function is carried out both by the radiation of visible red light and by the radiation of light, the length of which wave is above the visibility threshold or on which the sensitivity of the eye is too low to perceive them. Thus, the rear area of the vehicle 10 is sufficiently illuminated to allow the detection of the environment or of the marking lines in the rear area of the vehicle by the image taking device.

[53] The infrared light source 2 may include a diode

electroluminescent. [54] The advantages of such an infrared light source 2 are manifold. Firstly, the intensity of the infrared rays is sufficient for the detection of the environment located at the rear of the vehicle 10. Secondly, the intensity of the rays in the visible range complies with the regulations concerning the function of rear position light .

[55] Preferably, the light beam 3 is oriented towards the ground. In this embodiment, the optical system and the infrared light source 2 are arranged so that, when the module is mounted on the vehicle 10, the main emission axis 4 of the light beam 3 is inclined towards the horizontal plane L on which the vehicle 10 rests, that is to say towards the ground. As illustrated in FIG. 2, the main emission axis 4 has an angle a with a longitudinal axis H. The axis of the cone comprising the rays of the light beams is thus angularly offset with the longitudinal axis H.

[56] The longitudinal axis H is a longitudinal direction axis and parallel to the horizontal plane L on which the vehicle 10 rests. The angle a may vary depending on the vehicle 10 on which the light module 1 is intended to be mounted. More particularly, the angle a can be adjusted as a function of the height at which the light module 1 is intended to be mounted on the vehicle 10.

[57] The angle a between the main emission axis 4 and the longitudinal axis H is

preferably between 0.7 ° and 3.5 °, especially when the light module is arranged on the vehicle at a height of between 0.25 m and 1.2 m.

[58] Preferably, the light module 1 is designed so that the intersection between the rays of the light beam 3 and the horizontal plane L on which the vehicle 10 rests is located at a minimum distance E from the rear of the vehicle 10 between 0 m and 20 m. Furthermore, the light module 1 is designed so that the intersection between the main emission axis 4 and the horizontal plane L on which the vehicle 10 rests is located at a distance D from the rear of the vehicle 10 of between 5 m and 25 m.

[59] As illustrated in Figure 2, the rays of the light beam 3 form a maximum angle b with the longitudinal axis H between 1 ° and 15 °. [60] Thus, the light module allows the lighting, for example of the region located at the rear of the vehicle for a driving assistance system. It is also designed to respect the limits of the regulation of the rear position light function in terms of light intensity on the different orientations of the light rays. The invention thus makes it possible, by the infrared light source 2 and the orientation of the light beam 3, to illuminate in the visible without exceeding the maximum intensities of the regulations. In other words, the infrared light source 2 allows lighting whose perception by the human eye is weak but sufficient to fulfill a position light function and whose perception by a detector, such as an image taking device is sufficient to obtain an image capable of being processed for assistance in driving the vehicle.

[61] In one embodiment, the infrared light source 2 is

irremovable. More particularly, it is not possible to adjust the arrangement of the light source to modify the angle a of inclination of the main emission axis 4.

[62] In one embodiment, the light module 1 comprises at least one complementary light source designed to emit infrared light rays and / or light rays in the visible region participating in the production of the light beam (3).

[63] The complementary light sources thus contribute to the first

lighting function and / or the second signaling function.

[64] The invention also relates to a vehicle 10 comprising such a light module 1 rear of vehicle 10 according to the present invention. As a variant, the vehicle 10 can comprise several light modules 1. The light modules 1 can for example be distributed in one or more rear lights.

[65] The invention also relates to an assistance system comprising at least one light module 1 according to the invention. This assistance system further comprises at least one image taking device 6 such as at least one camera or one camera. This image taking device 6 is designed to be able to capture an image of a region illuminated by at least part of the light beam 3 emitted by the light module 1.

[66] In particular, the image taking device 6 makes it possible to take an image of a located at the rear of the vehicle 10.

[67] The image pickup device 6 can be an image pickup device

infrared like an infrared camera. The image taking device can then capture the infrared light emitted by the infrared light source 2. The infrared camera can be arranged to film or generate images of the ground surface located at the rear of the vehicle 10 at least in part lit by the light module 1. The infrared camera can be placed at the rear of the vehicle 1 0.

[68] In addition, this image taking device 6 can also make it possible to capture the light emitted in the visible range.

[69] In another example, the image taking device 6 is capable of picking up at least part of the light emitted between 650 nm and 1100 nm. In particular, the image taking device 6 can be sensitive to wavelengths between 650 nm and 780 nm and / or between 780 nm and 1100 nm. It is notably more sensitive to these wavelengths than the human eye. The image taking device 6 can therefore capture a large part of the energy flux emitted by the infrared light source 2 of the light module 1.

[70] Finally, the image taking device 6 makes it possible to capture images of the ground surface located near and at the rear of the motor vehicle, and comprising information relating to obstacles and markings on the road, and it is sensitive to at least part of the light emitted by the infrared light source 2, which allows it to capture images even when the external brightness is reduced.

[71] In one embodiment, the infrared camera is a Vis / NIR camera.

In one embodiment, the infrared camera is a rear camera, part of a 360 ° camera system for a vehicle.

[72] The driver assistance system also includes a central unit, which can correspond to any hardware (hardware) and / or software (software) an intelligent management unit, comprising at least one computer, for example one or more microprocessors, for implementing a driving assistance method. This central unit can be arranged in any location of the motor vehicle. It can for example be integrated into the on-board computer of the motor vehicle. As a variant, it can be offset within an image taking device 6. The driving assistance system thus comprises a device for detecting markings and / or any element on the ground, formed by the combination of '' at least one image taking device and one image processing unit.

[73] The assistance system further comprises communication means connecting the image-taking device (s) 6 to the central unit, so as to receive the images from the image-taking device 6. The central unit includes image processing software to deduce the information necessary for driving assistance. Thus, the assistance system more generally comprises a device for detecting markings on the ground and / or obstacle and / or any element in a lateral zone of the vehicle. The system

assistance further comprises communication means connecting the central unit to the light module and at least one image pickup device 6, to control, activate and / or deactivate them.

[74] The invention also relates to a vehicle 10 comprising such a driving assistance system.

[75] The present invention also relates to a method of lighting a rear region of a vehicle. An embodiment of the method for lighting a rear region of the vehicle 10 is described below. The method is implemented within the vehicle 10 as described above.

[76] The lighting process includes a first step of emitting a

light beam by a light module 1 according to the invention. The light module 1 then illuminates the region located at the rear of the vehicle 10 on which said light module 1 is mounted.

[77] The invention also relates to a method of assisting in driving a vehicle. An embodiment of said assistance method is described below. [78] The assistance method comprises a first step of emitting a light beam 3 by the light module 1 according to the invention. The light module 1 then illuminates a region located at the rear of the vehicle 10 on which said light module 1 is mounted.

[79] The assistance process includes a second step of capturing water

at least one image comprising at least part of the region located at the rear of the vehicle 10.

[80] This assistance method advantageously allows the production of an image of the region located at the rear of the vehicle 10 whose lighting is of sufficient intensity for the detection of a marking or an obstacle or a change in the structure of the track, in particular thanks to the contribution of infrared radiation from the infrared light source 2.

[81] The assistance process may include a third step of detecting the environment, in particular markings and / or obstacles, of the region located at the rear of the vehicle using the image produced.

[82] Preferably, the third step is implemented by computer. In an alternative embodiment, the vehicle 10 may include a display for displaying the image taken by the image taking device 6.

Claims

[Claim 1] [Light module (1) of a motor vehicle (10) capable of emitting a light beam, characterized in that it comprises at least one infrared light source (2) designed to emit infrared light rays and light rays in the visible region participating in the formation of said light beam, to perform a rear position light function, said infrared light source (2) emitting at least 50% of its energy flux between 700 nm and 1100 nm and at least 0.1% of its energy flow between 600 nm and 700 nm.

[Claim 2] Light module (1) according to claim 1 characterized in that said infrared light source (2) is arranged so that a main axis of emission (4) of the light beam (3) is inclined towards a plane horizontal (L) of the ground on which said vehicle (10) rests when said light module (1) is mounted on the vehicle (10).

[Claim 3] Light module (1) according to one of the claims

above, characterized in that it comprises an optical system associated with the infrared light source (2) and in that the optical system and the infrared light source (2) are arranged so that a main emission axis ( 4) of the light beam (3) is inclined towards a horizontal plane (L) of the ground on which said vehicle (10) rests when said light module (1) is mounted on the vehicle (10).

[Claim 4] Light module (1) according to one of the claims

above, in which the infrared light source (2) and / or the optical system and the infrared light source are arranged so that, when the module is mounted on a vehicle (10), the main axis of emission (4) crosses the horizontal plane (L) on which the vehicle rests at a distance (D) between 5 m and 25 m from the rear of said vehicle (10).

[Claim 5] Light module (1) according to one of the claims

previous, characterized in that it comprises at least one complementary light source designed to emit light rays

infrared and / or light rays in the visible region participating in the creation of the light beam (3).

[Claim 6] Driving assistance system comprising a light module (1) according to one of the preceding claims.

[Claim 7] Driving assistance system according to the preceding claim, characterized in that it comprises an image taking device (6) capable of capturing an image of a region illuminated by at least part of the beam light (3) emitted by the light module (1)).

[Claim 8] Driving assistance system according to the preceding claim, characterized in that the image taking device (6) is capable of capturing at least part of the light emitted between 650 nm and 1100 nm, preferably between 700 nm and 1100 nm.

[Claim 9] Method for assisting in driving a vehicle,

characterized in that it comprises a step of emitting a light beam (3) by a light module (1) according to one of claims 1 to 8, and a step of capturing an image of a region illuminated by said light beam (3). ]