Visible light sensing system for vehicle, vehicle comprising the system and method for deployment of said system in a vehicle

Abstract

A visible light sensing system for a vehicle comprises luminous devices controlled by a control unit to provide various lighting configurations, and light sensors. The luminous devices irradiate light onto the vehicle's environment, which is reflected and detected by the sensors. Each sensor includes a Single-Photon Avalanche Diode array detector and an optical system. Some luminous devices emit pulsed light with pulses shorter than 1µs. Certain light sensors are remote sensors located outside the luminous devices and distributed in a network communicating with the control unit. Each remote sensor includes a microprocessor performing low layer signal processing of the reflected light, providing the control unit with pre-processed data, including correlation data, based on the sensor's location. This system enables efficient environment sensing for vehicle applications by combining distributed sensing, short-pulse illumination, and local signal processing.

Description

DescriptionTitle : Visible light sensing system for vehicle, vehicle comprising the system and method for deployment of said system in a vehicle

[0001] The present invention is related to the field of lighting (and / or signaling) devices for vehicles, in particular for motorized vehicles such as automotive vehicles, equipped with “Lidar” type technology, herein called “visible light sensing”. The invention relates more particularly to the configuration of a visible light sensing on the vehicle, to facilitate the integration and / or improve the assistance to users (i.e. the driver or a person inside or outside the vehicle).

[0002] Indeed, several technical problems emerge in the field of luminous devices for vehicles using light signal detection in order to provide better assistance to users. Such assistance to users, often called driving assistance, comprises the use of sensors to inform the driver (or to directly inform the vehicle or any user able to access the information) of objects surrounding the vehicle or any type of configuration of the vehicle which is a relevant information for the users. Such assistance to users is known in the filed of motorized vehicles, for example with the Advanced Driver Assistance System (ADAS) & Autonomous Driving (AD) Systems (ADS), which apply to different ranges of speed (generally lower speed for ADAS and higher speed for AD) and have different levels defined by the regulation in force in various countries. The various functionalities are thus known and don’t need to be detailed in the present application which aims at improving such assistance. To achieve this goal, sensors play a crucial role, since they receive the information from the exterior of the vehicle, containing the data that will be interpreted in order to create a map of the surrounding objects. There are many different sensors which are intended to accomplish this mission. Most of them use ultrasound, with acoustic pulses. Cameras are also adapted to acquire infrared or visible ambient light. However, in some cases, for example when the sensing area is too wide or the ambient light is too high, etc., cameras may not be adequate for an accurate detection. The “Lidar” technology (« Light Detection and Ranging » or « Laser Imaging Detection and Ranging ») is a well-known technology of laser (or light) remote sensing, using a remote measurement technique based on the analysis of the properties of a beam of light returned to its emitter.

[0003] An advantageous type of LiDAR technology has been developed by using the visible light, so that the reflection of light emitted by the luminous device of vehicles can be used by sensor for enabling detection in the environment of the vehicle. This technology generally uses the blue wavelength (410-490nm) for the ease of discrimination from the natural light (from the sun), because luminous devices of vehicles generally emit light with a peak in the blue wavelength, but the main advantage is that the luminous device of the vehicle is used for sensing. The same device which may be used for lighting functions (such as a Low Beam LB, a High Beam HB, a Daytime Running Light DRL, a Position Light PL, a Stop Light, aReverse Light, a Corner Light CL, or a Turn Indicator Tl), may also be used for detection of objects. The term “light sensors” here designates the sensor as a whole, which generally comprises a photodiode (a semiconductor component having the capacity to capture radiation from the optical domain and transform it into an electrical signal), generally behind an optical system for light transmission and / or filtering. Such sensor transmits the electrical signal to the control unit, which is configured to process them and gather data to detect objects in the environment and then provide the various users (drivers) assistance functions. The term “Lidar” is thus used in the present application to refer to this technology using the visible light emitted by the luminous device of vehicle (instead of requiring additional emitting devices). This technology has been used on many different ways, in field of the present application, for example as disclosed in patent applications EP4201740, EP4201741 , EP4202496, EP4202503, EP4202495, EP4202384 and WO202330817. These applications teach the use of several light emitters (luminous devices) having different parameters such as the frequency (of signal), the wavelength, the wave shape, the angle of projection / reflection, the lenses and so one, with the signal being acquired by several respective sensors dedicated to these various parameters (with filters, angles of detection, lenses and so one). The present application uses this technology based on the light emitted by the luminous devices of a vehicle encoding a signal which is returned to sensors and analyzed by a processing unit (or “control unit”) configured to compute various features, including for example the time of flight (ToF) of the signal encoded within the emitted light and to allow various functionalities such as obtaining information about the surrounding objects.

[0004] A problem with light sensors for visible light sensing (Lidar) of vehicles concerns the integration of sensors and their modularity (i.e., visual appearance, sensor position, lens configuration, angle of detection and so on). Generally, this integration of sensors is difficult, in particular into headlamps. For example, the elevation might be too high in the headlamp or the shape of headlamp might generate some blind spots. Therefore, each change in the headlamp might impact the overall performances and a complete requalification of the sensors is required. Furthermore, this problem is often worsened by the needs of the assistance to users like AD or ADAS which raise many problems, in particular because of various levels of assistance. Indeed, sensors integrated into the luminous devices of the vehicle are sometimes not sufficiently efficient for the needs of assistance to users.

[0005] The present invention aims at overcoming at least some drawbacks of the priori by providing solutions for integrating light sensors in a luminous device for vehicles and / or optimizing the assistance to users and / or limiting the increase of cost and / or energy consumption, while complying with regulations.

[0006] This purpose is reached by a system comprising a plurality of luminous devices and light sensors. At least part of the luminous devices emit pulsed light withpulses shorter than 1 ps, and at least part of the light sensors are remote sensors located outside the luminous devices. These remote sensors are distributed in a network communicating with the control unit. Each remote sensor comprises a microprocessor configured to perform signal computation for low layer signal processing of the reflected light, providing the control unit with pre-processed data comprising correlation data. This configuration offers several technical advantages. The use of short light pulses allows for high temporal resolution in time-of-flight measurements, enabling accurate distance calculations. The distribution of remote sensors outside the luminous devices provides greater flexibility in sensor placement, thus improving coverage and reducing blind spots. The local processing of data by each sensor's microprocessor reduces the overall data transmission load and allows for faster, more efficient processing of environmental information.

[0007] In some embodiments, the microprocessor of each remote sensor exports its own pre-processed data to a central unit of the sensors' network, which gathers data from all remote sensors. This centralized data collection allows for efficient integration of information from multiple sensors, enabling more comprehensive environmental mapping and / or data fusion.

[0008] Furthermore, this central unit may integrate the location information of each remote sensor and transform the gathered data into a point cloud of the vehicle's environment, which is then exported to a network controlled by the main control unit. This approach offers several technical benefits: it enables a distributed processing architecture, reducing the computational load on any single unit; it allows for the creation of a comprehensive 3D map of the vehicle's surroundings by combining data from multiple perspectives; and it facilitates the implementation of advanced driver assistance and autonomous driving functions by providing a rich, processed dataset to the main control unit. The system's architecture thus enables more efficient data processing, thus reducing latency in environmental perception and decision-making processes critical for vehicle safety and autonomous operation.

[0009] The system may be designed such that at least one light sensor has a field of view (FOV) defined by its associated optical system, wherein the environment within said FOV is illuminated by several distinct light sources comprised within one or more of the luminous devices. These distinct light sources preferably emit high- frequency pulsed light. In some configurations, first light sources emit pulsed light while second light sources, distinct from the first light sources, emit low-frequency pulsed light or continuous light. The second light sources may not contribute to the sensing function, allowing for a mixed emission strategy that can reduce overall system cost while maintaining effective coverage.

[0010] To enhance the system's versatility and robustness, different light sensors of the vehicle may have different carrier wavelength bands associated with them. This multi-wavelength approach allows for simultaneous operation of multiple sensorswithout cross-interference.

[0011] The low layer signal processing performed by the microprocessor of each light sensor may comprise a correlation operation, preferably designed to match the pulses emitted by the luminous devices with the light received by the light detector. This process allows for efficient and accurate detection of the reflected light signals, enabling precise time-of-flight measurements and, consequently, accurate distance calculations.

[0012] In certain embodiments, the light detectors are pixelated, with each pixel preferably comprising a distinct Single-Photon Avalanche Diode (SPAD) array. This pixelated structure allows for spatial resolution within each sensor, enabling the system to detect multiple objects or features within the sensor's field of view.

[0013] The luminous devices may comprise groups of light sources where all the sources of the same group share a light feature, which is not shared by any other light source of a different group. This light feature is preferably at least one feature among the frequency, the color, and the pulse pattern. This configuration enables the system to have various information encoded at various locations within the lighting and sensing field, potentially improving the system's ability to distinguish between different light sources and reduce interference.

[0014] In some embodiments, the light pulses emitted by the luminous devices are shorter than 200ns, preferably between 50ns and 200ns. This short pulse duration is crucial for achieving high spatial resolution in the time-of-flight measurements, leading to more precise distance calculations and enabling the system to capture rapid changes in the vehicle's environment.

[0015] The terms “luminous device” refer to devices enclosed in a housing, comprising at least a wall transparent to visible light and an opaque wall, and including:- either lighting devices that allow lighting the environment of the vehicle, to be able to see, for example performing functions such as low beam headlights (LB), corner lights (CL) or high beam headlights (HB), even if the latter are generally prohibited in certain conditions, particularly in urban areas,- or signaling devices to be able to be seen, performing luminous functions such as position lights (PL), rear position lights (RPL) or daytime running lights (DRL) but also devices which make it possible to signal the actions of a driver to other users, such as for example brake lights ("stop light" or SL), direction indicator lights (“turn indicator” or Tl) or hazard lights (“warning” or W).

[0016] It is understood that the remote sensors being located outside the luminous devices means that they are not comprised within a housing of a luminous device.

[0017] In various embodiments of the present invention, the luminous devices may comprise multiple light sources, each dedicated to one or more luminous functions of the device . These light sources can be configured to provide different lighting functions as seen above (PL, CL, LB, HB, DRL, SL, Tl, W).

[0018] Other features and advantages of the present invention will appear more clearly on reading the description of various embodiments below, made with reference tothe appended drawings. Indeed, to complete the description and to allow a better understanding of the invention, a set of drawings is provided. These drawings illustrate one embodiment of the invention and form an integral part of the description, which should not be construed as limiting the scope of the invention, but merely as an example of how the invention may be carried out. The drawings include the following figures:

[0019] [Fig 1] shows a schematic view of a luminous device for vehicle according to some embodiments ;

[0020] [Fig 2] shows a schematic view of a lighting vehicle and its distributed network of sensors.

[0021] The present invention relates to a visible light sensing solutions and in particular to a visible light sensing system, vehicles including such system and a method for deployment of such system into vehicles. This application refers to a control unit which controls the lighting but which is also configured to control the lighting and sensing functions, for example by carrying out calculations, comparisons, and so on. Those skilled in the art will of course understand that it may be several control units for the different tasks and cooperating to implement the invention or a single unit carrying out all the tasks. Furthermore, those skilled in the art naturally understand, by the nature of the tasks carried out, that such a unit will generally include at least one processor executing instructions and that various forms of implementation are possible (with different electronic components) and that it is therefore not necessary to provide details on the types of materials usable or used. The drawings presented on the figure pages are provided solely by way of example and in a very schematic manner, so that those skilled in the art will be able to imagine any type of variants based on the content of the present application.

[0022] The light sources within each luminous device (5) are preferably based on lightemitting diode (LED) technology, known for its efficiency, longevity, and compact size. These LED-based light sources may emit light of various colors and possess different optical characteristics to suit their specific functions. For instance, a single luminous device may incorporate white LEDs for main beam functions, amber LEDs for turn indicators, and red LEDs for rear position lights.

[0023] In some embodiments, the light sources may be native emitters, where the semiconductor material of the LED directly emits light at the desired wavelength. Alternatively, the light sources may be converted emitters, utilizing a wavelength conversion element. This conversion element, typically a phosphor or quantum dot material, absorbs light from a primary emitter (usually a blue or ultraviolet LED) and re-emits it at a longer wavelength. This technique, well-known in the art, allows for the creation of white light or other specific colors from a single type of LED chip.

[0024] As it is well known in the art, each light source, whether based on native or converted emitters, is characterized by its peak wavelength, which corresponds tothe wavelength at which the emission spectrum reaches its maximum intensity. The peak wavelength is a crucial parameter in defining the perceived color of the light and its suitability for specific automotive lighting functions. For instance, white light sources used in headlamps typically have a broad spectrum with a peak in the blue or cool white region, while rear position lights have a distinct peak in the red portion of the spectrum.

[0025] The combination of different light sources within a single luminous device (5) allows for a compact and versatile lighting solution. This approach enables the system to meet various regulatory requirements for color, intensity, and beam pattern while also providing flexibility for advanced lighting features such as adaptive front-lighting systems (AFS) or matrix beam patterns. Moreover, this multi-source configuration facilitates the integration of sensing functions within the luminous devices, as certain light sources can be dedicated to illumination for sensing purposes without compromising the primary lighting functions of the device.

[0026] In some embodiments, at least one of the luminous devices comprises a matrix arrangement of light pixels in lines and columns. In certain particular cases, the matrix includes at least 2000 light sources in the solid state. A matrix arrangement is a typical example of this process. Lines can be grouped into projected distance intervals and each column in each group represents an angle interval. This angle value depends on the resolution of the matrix, which is generally between 0.01 ° per column and 0.5° per column. This control of rows and columns allows independently control of the angle and range, in addition to the intensity and allows managing several light sources at the same time. In some of these embodiments, certain rows or columns are turned off compared to the initial light intensity. Indeed, modern luminous devices often include “solid state” light sources and the invention makes it possible to take advantage of this type of device, which notably allows adaptation of photometry This process aims to find the optimal light pattern to be projected by a luminous device.

[0027] In an embodiment, the light sources of at least some of the luminous devices are LEDs emitting incoherent light, as opposed to solid-state lasers such as laser diodes such as Vertical-Cavity Surface- Emitting Lasers (VCSELs). In a preferred embodiment, the light sources of all of the luminous devices are LEDs emitting incoherent light. It is indeed highly preferred that light sources designed for automotive lighting are not laser sources, as laser sources are expensive, require complex and costly security systems, and are not suitable for use with usual optical systems for classic luminous devices.

[0028] Some embodiments of the present invention concern a visible light sensing system (1 ) for a vehicle (100), said system (1 ) comprising, on the one hand, a plurality of luminous devices (5) controlled by a control unit (2) comprising processing means to provide a plurality of lighting configurations of said system (1) and, on the other hand, a plurality of light sensor (3) comprising an optical system (30) and a lightdetector (31) to acquire a portion of a reflection of said projected light, said control unit (2) being further configured to receive data from the said sensors for acquiring data on the external environment of the vehicle, the system being characterized in that :- at least part of said light sensors (3) are remote sensors located outside the luminous devices (5) and distributed in a network (300) of sensors communicating with the control unit (2),- each remote sensor (3) further comprises a microprocessor (32) configured to perform high frequency signal computation for low layer signal processing of the reflected light, in order to provide said control unit (2) with data pre-processed according to the location of the remote sensor.

[0029] The sensing system (1 ) therefore comprises a plurality of luminous devices (5) which may be of the type of examples (PL, CL, LB, HB, DRL, SL, Tl, W) provided above, which are neither exhaustive nor limiting. In general, it will be considered that the system also includes the control (or processing) unit (2) which makes it possible to control the system (1) and implement the process. Each device may include one or more light source(s) depending on the type of lighting (incandescent bulbs or light-emitting diode (LED), for example).

[0030] It should be noted that the light sensors (3) are considered as part of the sensing system, may the sensors be included in the headlamps or elsewhere. This consideration of the system including the control unit and sensors are thus not limiting the scope and those of skills in the art will appreciate the various ways to implement the invention for the present disclosure.

[0031] It is thus understood that the distribution of (at least part of) the sensors outside the luminous devices allows to avoid all the problems of integration of sensors into the luminous devices such as lamps (headlamps for example) and allows to reuse standalone qualified sensors which locations (i.e. , positions) in vehicle can be adjusted to maximize the performances. Such distribution requires the architecture of the sensor to integrate high frequency calculation (1 to 10Ghz for example) and takes advantage of a new and unique mapping of light sensors locations and sensing areas (sensing fields) around the vehicle, which allow to optimize the performance (e.g., for drivers’ assistance).

[0032] In some embodiments, said microprocessor (32) of each remote sensor (3) exports its own data to a central unit of said sensors’ network (300) gathering the data of all the remote sensors (3). Such export will generally be performed at lower frequency than the high frequency calculation. Moreover, such configuration of pre-processing and export allows to limit the amount of data to communicate and speeds the computation performed at higher levels of the system.

[0033] In some embodiments, said central unit integrates the information of the location of each remote sensor (3) and transforms the gathered data of the remote sensors (3) into a point cloud of the environment of the vehicle, so as to export said point cloud to a network (200) controlled by said control unit (2). Thereby, the systemenables a distributed processing of the overall sensing field of the set of sensors and speeds up the generation of a full point cloud of the environment of the vehicle detected, thanks to the information about the locations (positions) of the various sensors.

[0034] In some embodiments, said central unit is integrated into said control unit (2). Indeed, it is of course possible to have only one processing unit for generating the point cloud and performing the other computations required by the functions implemented in the system. However, it can be advantageous to have an intermediate central unit managing the network (300) of remote sensors (3) and communicating with the control unit (2) performing the other functions.

[0035] In some embodiments, the communication of the remote sensors (3) with the control unit (2) is performed through a wire connection. In other embodiments, the remote sensors (3) further comprise a communication module configured for wireless communication with the control unit (2). In alternative embodiments, a combination of wire and wireless communication can be used, for example depending on the location of the sensors.

[0036] The present invention also concerns a vehicle, for example an automotive, comprising a visible light sensing system (1) according to some embodiments. Indeed, the integration of remote sensors will take place in the vehicle itself, independently from the structural integration of the luminous devices (the lighting field of which will of course still be taken into account for the deployment of the remote sensors). In some embodiments, the control unit (2) implements a plurality of driver assistance functions, said remote sensors (3) being integrated in the vehicle at locations determined according to at least one of said driver assistance functions. It is thus understood that the choice of the locations of the sensors can be made according to the various ADAS / AD functionalities implemented by the processing means present in the vehicle, instead of being imposed by the locations of the luminous devices as in the prior art. Thereby, the performances of the ADAS / AD can be greatly improved and / or the costs can be reduced (in addition to the reduction of cost when replacing a luminous device of the vehicle).

[0037] The present invention also concerns a method for deployment of a visible light sensing system (1) according to some embodiments. Such method preferably comprises :- configuring a plurality of remote sensors (3) with specific sensing areas and specific light detection abilities,- determining a plurality of locations for remote sensors on a vehicle, based on the size and shape of said vehicle and according to a plurality of driver assistance functions implemented in the control unit (2) of the vehicle,- selecting at least one remote sensor for each location, based on said sensing area and light detection ability,- deploying the selected remote sensors (3) by integrating them in said vehicle.

[0038] In preferred embodiments of the invention, the light sensors (3) are time of flight(ToF) sensors, specifically indirect time of flight sensors based on a correlation method. Time of flight technology measures the time it takes for light to travel from an emitter to an object and back to the sensor, allowing for accurate distance measurements. The indirect ToF method modulates the light source and measures a phase shift between the emitted and received light signals. This approach offers advantages in terms of robustness against ambient light and ability to measure longer distances compared to direct ToF methods. The correlation method involves comparing the received signal with a reference signal to determine the phase shift, which is then used to calculate the distance to the object. This technique is particularly advantageous in the context of visible light sensing for vehicles, as it enables precise and reliable mapping of the vehicle's surroundings even in challenging lighting conditions.

[0039] In certain embodiments, the light detector (31) of each light sensor (3) comprises a Single-Photon Avalanche Diode (SPAD) array. SPAD arrays are highly sensitive photon detectors capable of detecting single photons with high temporal resolution. This makes them particularly suitable for ToF applications in visible light sensing systems, as they can accurately detect the timing of returning light pulses, even in low-light conditions. The use of SPAD arrays in the present invention allows for improved sensitivity and timing precision in the detection of reflected light, which in turn enhances the accuracy of distance measurements and object detection. Furthermore, SPAD arrays can be fabricated using standard CMOS processes, leading to cost-effective and compact sensor designs suitable for widespread deployment in automotive applications.

[0040] The lighting devices (5) in the present invention are configured to emit pulsed light with pulsations shorter than 1 pS, preferentially shorter than 200ns. This short pulse duration is crucial for achieving high spatial resolution in the ToF measurements. By emitting such short pulses, the system can more accurately determine the time delay between emission and reception of the light, leading to more precise distance calculations. The use of sub-microsecond pulses also allows for higher measurement rates, enabling the system to capture rapid changes in the vehicle's environment. Shorter pulses, lower than 200ns, allow to further improve the performance. Moreover, these short pulses can help to reduce the impact of ambient light on the measurements, as the sensor can be synchronized to detect light only during the brief pulse periods. This feature, combined with the SPAD array detectors and indirect ToF method, contributes to a highly efficient and accurate visible light sensing system capable of providing detailed environmental information for advanced driver assistance and autonomous driving functions. It is to be noted that non-laser LEDs used in the preferred embodiments, the achievable pulsation time is superior to 20ns, and, in the case of a simple and cost-efficient driver architecture, superior to 50ns. It is important to note that, in a lighting device or on an automotive vehicle, many light sources are used; as such, an increase in the cost of the driver for each lightsource may have critical consequences for the overall cost of the inventive sensing system.

[0041] In preferred embodiments of the invention, each of the light sensors (3) is configured to filter out all but one visible wavelength band narrower than 50nm, preferentially narrower than 30nm, more preferentially 20nm. This filtering ensures that the SPAD arrays are only illuminated with light within this specific visible wavelength band, which is referred to as the carrier wavelength band associated with the light sensor. This narrow-band filtering significantly improves the signal-to- noise ratio of the sensor by reducing interference from ambient light and other light sources not associated with the sensing system.

[0042] In some embodiments, the light sensors (3) may have a field of view (FOV) wherein the environment is illuminated by several distinct light sources, located within a single luminous device or a plurality thereof, emitting high-frequency pulsed light. In an embodiment, first light sources emit pulsed light while second light sources distinct from the first light sources, which do not contribute to the sensing function, emit low-frequency pulsed light or continuous light. This mixed emission strategy means that not every luminous device has to be connected to the sensing system, which significantly reduces the overall cost of the system while maintaining effective coverage.

[0043] In some embodiments, the luminous devices (5) comprise second light sources emitting in the FOV of a given light sensor (3) and said second light sources do not have native light sources emitting at their peak wavelength within the carrier wavelength band associated with that light sensor. This configuration further reduces potential interference and improves the system's ability to distinguish between sensing signals and ambient or non-sensing light sources.

[0044] In some embodiments, the luminous devices (5) comprise third light sources emitting pulsed light in the FOV of a given light sensor (3) which do not have native light sources emitting at their peak wavelength within the carrier wavelength band associated with the given light sensor; in particular, said third light sources may have native light sources emitting at their peak wavelength within the carrier wavelength band associated with a light sensor distinct from the given light sensor. This configuration further reduces potential interference and improves the system's ability to distinguish between different pulsed light sources, such that a light source may be associated with a relevantly positioned light sensor without disturbing other light sensors.

[0045] To enhance the system's versatility and robustness, different sensors (3) of the vehicle (100) have different carrier wavelength bands associated with them. This multi-wavelength approach allows for simultaneous operation of multiple sensors without cross-interference and enables the system to be used, for instance, for luminous devices emitting white-colored light fit to be used on the front of the vehicle, and, for instance, luminous devices emitting red-colored light fit to be used on the rear of the vehicle.

[0046] In preferred embodiments of the invention, the low layer signal processing performed by the microprocessor (32) of each light sensor (3) comprises a correlation operation. This correlation operation is preferentially designed to match the pulses emitted by the luminous devices (5) with the light received by the light detector (31). This process allows for efficient and accurate detection of the reflected light signals, enabling precise time-of-flight measurements and, consequently, accurate distance calculations.

[0047] The pre-processed data provided by the microprocessor (32) to the control unit (2) comprises correlation data obtained through correlation-based processing. This correlation data represents the temporal relationship between emitted and received light signals, which is crucial for accurate time-of-flight measurements. Preferentially, this correlation data may be in the form of histogram data, representing the distribution of photon arrival times. This data compression technique allows for efficient transmission of relevant information while reducing the overall data bandwidth requirements.

[0048] In certain embodiments, the light detectors (31) are pixelated, with each pixel comprising a distinct Single-Photon Avalanche Diode (SPAD) array. This pixelated structure allows for spatial resolution within each sensor, enabling the system to detect multiple objects or features within the sensor's field of view. The use of distinct SPAD arrays for each pixel ensures high sensitivity and temporal resolution across the entire detector area.

[0049] In preferred embodiments, the pre-processed data provided by the microprocessor (32) comprises correlation data for each pixel of the pixelated light detector (31). Preferentially, this pixel-level correlation data may be in the form of histogram data. This detailed spatial and temporal analysis of the reflected light enables the system to create high-resolution 3D maps of the vehicle's surroundings. The combination of pixelated detectors and per-pixel correlation data, particularly when in histogram form, significantly enhances the system's ability to detect and classify objects in the vehicle's environment.

[0050] It is understood that the fact that several different kind of sensors may be designed according to the needs of the ADAS / AD, the performance will be increased and the deployment is thus facilitated by allowing virtually all locations for the remote sensors. For instance, the sensors

[0051] It is known from the technology of visible light sensing (also called flashing Lidar) that the luminous devices project light incorporating a signal (by a specific waveform of variation of intensity of the lighting: succession of pulses at high frequency) and that the sensors detect this signal at high frequency so that the control unit can compute a correlation between the emitted and received signals. The fact that various sensors will be distributed for the need of assistance and that the lighting pattern (or field) will be varied according to the invention, can gain further advantages by using various signals (by various specific waveforms) within the various luminous devices and / or the various parts of the luminous devices.The system is thus enabled to have various information encoded at various locations within the lighting and sensing field. Therefore, in some embodiments, the luminous devices (5) comprise groups of light sources and all the sources of the same group share a light feature, which is not shared by any other light source of a different group. For example, said light feature can be at least one feature among the frequency, the color and the pulse pattern. Accordingly, each or part of the remote sensors mays then be dedicated to one these features and a collection of various sensors adapted to various features, distributed at various locations enables a system with better performance and less risks of interferences.

[0052] The present application describes various technical characteristics and advantages with reference to the figures and / or various embodiments. Those skilled in the art will understand that the technical characteristics of a given embodiment can in fact be combined with characteristics of another embodiment unless the opposite is explicitly mentioned or it is obvious that these characteristics are incompatible or that the combination does not provide a solution to at least one of the technical problems mentioned in this application. In addition, the technical characteristics described in a given embodiment can be isolated from the other characteristics of this mode unless the opposite is explicitly mentioned.

[0053] Detailed list of references in the figures :1 luminous device 100 vehicle2 control unit 200 vehicle network3 light sensor30 optical system31 light detector32 microprocessor5 lighting (and / or signaling) device

Claims

Claims

1. Visible light sensing system (1 ) for a vehicle (100), said system (1 ) comprising, on the one hand, a plurality of luminous devices (5) controlled by a control unit (2) comprising processing means to provide a plurality of lighting configurations of said system (1), said luminous devices irradiating first light onto the vehicle's environment, said first light being reflected by the environment into second light, and on the other hand, a plurality of light sensors (3), each light sensor comprising an own light detector (31 ) and an own optical system (30) configured to direct a portion of the second light on the light detector (31), each light detector (31) comprising an distinct Single-Photon Avalanche Diode array, the control unit (2) being further configured to receive data from the said sensors for acquiring data on the external environment of the vehicle, wherein: at least part of said luminous devices emit pulsed light with light pulses shorter than 1 ps, at least part of said light sensors (3) are remote sensors located outside the luminous devices (5) and distributed in a network (300) of sensors communicating with the control unit (2), each remote sensor (3) further comprises a microprocessor (32) configured to perform signal computation for low layer signal processing of the reflected light, in order to provide said control unit (2) with data pre-processed according to the location of the remote sensor, said pre-processed data comprising correlation data.

2. System according to claim 1 , wherein said microprocessor (32) of each remote sensor (3) exports its own pre-processed data to a central unit of said sensors’ network (300) gathering the data of all the remote sensors (3).

3. System according to claim 2, wherein said central unit integrates the information of the location of each remote sensor (3) and transforms the gathered data of the remote sensors (3) into a point cloud of the environment of the vehicle, so as to export said point cloud to a network (200) controlled by said control unit(2).

4. System according to any one of claims 1 to 3, wherein each of the light sensors(3) is configured to filter out all but one visible wavelength band narrower than 50nm, preferably narrower than 30nm, more preferably 20nm.

5. System according to any one of claims 1 to 4, wherein at least one light sensor (3) has a field of view (FOV) defined by its associated optical system (30), and wherein the environment within said FOV is illuminated by several distinct lightsources comprised within one or more of the luminous devices (5), said distinct light sources preferably emitting high-frequency pulsed light.

6. System according to claim 5, wherein first light sources emit pulsed light while second light sources distinct from the first light sources emit low-frequency pulsed light or continuous light as the first light, preferably wherein the second light sources do not contribute to the sensing function.

7. System according to any one of claims 1 to 6, wherein different light sensors (3) of the vehicle (100) have different carrier wavelength bands associated with them, preferably allowing simultaneous operation of multiple sensors without cross-interference.

8. System according to any one of claims 1 to 7, wherein the low layer signal processing performed by the microprocessor (32) of each light sensor (3) comprises a correlation operation, preferably designed to match the pulses emitted by the luminous devices (5) with the light received by the light detector (31).

9. System according to any one of claims 1 to 8, wherein the pre-processed data provided by the microprocessor (32) to the control unit (2) comprises correlation data in the form of histogram data, preferably representing the distribution of photon arrival times.

10. System according to any one of claims 1 to 9, wherein the light detectors (31) are pixelated, with each pixel preferably comprising a distinct Single-Photon Avalanche Diode (SPAD) array.

11. System according to claim 10, wherein the pre-processed data provided by the microprocessor (32) comprises correlation data for each pixel of the pixelated light detector (31), preferably in the form of histogram data.

12. System according to any one of claims 1 to 11 , wherein the luminous devices (5) comprise groups of light sources and all the sources of the same group share a light feature, which is not shared by any other light source of a different group, said light feature preferably being at least one feature among the frequency, the color and the pulse pattern.

13. System according to any one of claims 1 to 12, wherein the light pulses are shorter than 200ns, preferably between 50ns and 200ns.

14. An automotive vehicle, characterized in that it comprises a visible light sensing system (1) according to any one of claims 1 to 13.

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