Method and device for controlling the light intensity of a head-up vision system.

Abstract

The present invention relates to a method and device for controlling the light intensity of a head-up display system during night driving of a vehicle. The method is implemented by a processor and comprises the following steps: - obtaining (51) data representative of the vehicle's night driving conditions; - displaying (52) information by the head-up display system with a light intensity level dependent on said data; - obtaining (53) the continuous driving time of the vehicle; - determining (54) a reduction in the light intensity level as a function of the continuous driving time of the vehicle, using a light intensity reduction chart; and - reducing (55) the light intensity level according to the reduction determined by the light intensity reduction chart. Figure for the abstract: Figure 6

Description

Title of the invention: Method and device for controlling the light intensity of a head-up vision system. Technical field

[0001] The present invention relates to methods and devices for controlling the light intensity of a head-up display system. Technological background

[0002] Some contemporary vehicles have several screens on board to display information useful to the driver for driving the vehicle as well as comfort information, such as, for example, information for interacting with the infotainment system, also called the IVI system (from the English "In-Vehicle Infotainment" or in French "Infodivertissement embargo"), of the vehicle.

[0003] Among these screens, it is known to embed one or more LCD (Liquid Crystal Display) type screens, for example TFT (Thin-Film Transistor) type, or OLED (Organic Light-Emitting Diode) type.

[0004] It is also known to equip certain vehicles with a Head Up Display (HUD) system. A HUD system makes it possible to display information useful for driving the vehicle at the driver's eye level, according to light intensity levels which can automatically adapt to the increase or decrease in brightness outside the vehicle (day / night mode). This adaptation of the light intensity level of a HUD system can also be manually adjusted within a range of predetermined values.

[0005] Manual adjustment of the light intensity level of a VTH system is usually done by using interfaces that can take the form of a touch screen or a physical button. These interfaces are not always visible or even usable when blind, making access to this manual adjustment difficult. Furthermore, these interfaces require special attention from the driver, greatly distracting him from his driving.

[0006] Furthermore, once chosen, this setting is fixed and is not frequently changed subsequently by the driver, regardless of the driving conditions and / or his habituation to the dark.

[0007] Furthermore, the human eye adapts to darkness. Indeed, the human eye is able to see objects in the dark from about one ten-thousandth of a lux thanks to the pupillary reaction (5 seconds) then to retinal adaptation or habituation (1 hour). Retinal habituation also takes place in two phases, the first (rapid or photopic phase) lasting approximately 3 minutes and the second (slow or scotopic phase) lasting between 30 minutes and 1 hour depending on age.

[0008] Furthermore, after one minute of adaptation to low light, the retina of the human eye is ten times more sensitive to light. After 20 minutes, it is 6,000 times more sensitive. After 30 minutes, the eye reaches its limit and then requires 30,000 times less light.

[0009] Retinal habituation can become a disadvantage for a driver when, for example, once the retinas of his eyes are accustomed to a low level of light intensity, this driver, driving a vehicle for several tens of minutes in this very dark environment, can be bothered or even dazzled by a high level of light intensity projected directly into his field of vision by a VTH system. The driver can also experience increased visual fatigue.

[0010] It is therefore necessary to improve VTH systems so that a driver experiences comfort in using these systems when driving at night or during the day, regardless of the length of their journey. Summary of the present invention

[0011] An object of the present invention is to control the light intensity of a VTH system.

[0012] Another object of the present invention is to provide night driving comfort.

[0013] Another object of the present invention is to improve road safety.

[0014] According to a first aspect, the present invention relates to a method for controlling a light intensity of a head-up display system in night driving conditions of a vehicle, said method being implemented by a processor, said method comprising the following steps: obtaining data representative of night driving conditions of the vehicle; displaying information by the head-up system with a light intensity level dependent on said data; obtaining a continuous driving time of the vehicle; determining a reduction in the light intensity level as a function of the continuous driving time of the vehicle and using a light intensity reduction chart relating a percentage reduction in a light intensity of a light source as a function of a duration of exposure of a human eye to said light source;and reducing the level of light intensity according to the determined reduction of the level of light intensity.;

[0015] According to a particular and non-limiting exemplary embodiment, the level of light intensity is reduced if the duration of continuous driving of the vehicle is greater than a threshold value.

[0016] According to a particular and non-limiting exemplary embodiment, the level of light intensity is increasingly reduced when the continuous driving time of the vehicle increases.

[0017] According to a particular and non-limiting exemplary embodiment, said data is obtained from a measurement of brightness outside the vehicle.

[0018] According to a particular and non-limiting exemplary embodiment, said data is also obtained from time measurement information and / or geolocation information.

[0019] According to a particular and non-limiting exemplary embodiment, the duration of continuous driving of the vehicle corresponds to a duration of continuous operation of the vehicle engine.

[0020] According to a second aspect, the present invention relates to a device for controlling a light intensity of a head-up vision system in night driving conditions of a vehicle, said device comprising a memory associated with at least one processor configured for implementing the steps of the method as described above according to the first aspect.

[0021] According to a third aspect, the present invention relates to a vehicle, for example of the automobile type, comprising a device as described above according to the second aspect of the present invention.

[0022] According to a fourth aspect, the present invention relates to a computer program which comprises instructions adapted for executing the steps of the method according to the first aspect of the present invention, in particular when the computer program is executed by at least one processor.

[0023] Such a computer program may use any programming language, and be in the form of source code, object code, or intermediate code between source code and object code, such as in a partially compiled form, or in any other desirable form.

[0024] 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 method according to the first aspect of the present invention.

[0025] On the one hand, the recording medium may be any entity or device capable of storing the program. For example, the medium may comprise a storage means, such as a ROM memory, a CD-ROM or a microelectronic circuit type ROM memory, or a magnetic recording means or a hard disk.

[0026] On the other hand, this recording medium may also be a transmissible medium such as an electrical or optical signal, such a signal being able to be conveyed via an electrical or optical cable, by conventional or hertzian radio or by self-directed laser beam or by other means. The computer program according to the present invention can in particular be downloaded from an Internet-type network.

[0027] Alternatively, the recording medium may be an integrated circuit in which the computer program is incorporated, the integrated circuit being adapted to perform or to be used in performing the method in question. Brief description of the figures

[0028] Other characteristics and advantages of the present invention will emerge from the description of the particular and non-limiting exemplary embodiments of the present invention below, with reference to the appended figures 1 to 6, in which:

[0029] [Fig-1] schematically illustrates the projection of images in a vehicle, according to a particular and non-limiting example of embodiment of the present invention;

[0030] [Fig.2] schematically illustrates a field of vision associated with a position of driving the vehicle of [Fig.l], according to a particular and non-limiting exemplary embodiment of the present invention;

[0031] [Fig.3] schematically illustrates a display of graphic objects according to an example particular and non-limiting embodiment of the present invention;

[0032] [Fig.4] schematically illustrates a VTH system for the vehicle 10, according to a particular and non-limiting example of embodiment of the present invention;

[0033] [Fig.5] schematically illustrates a device for controlling a light intensity of a VTH system in night driving conditions of a vehicle, according to a particular and non-limiting exemplary embodiment of the present invention; and

[0034] [Fig.6] illustrates a flowchart of the different stages of a control process of a light intensity of a VTH system in night driving conditions of a vehicle, according to a particular and non-limiting exemplary embodiment of the present invention. Description of examples of implementation

[0035] A method and a device for controlling a light intensity of a head-up vision system in night driving conditions of a vehicle will now be described in the following with reference jointly to FIGS. 1 to 6. The same elements are identified with the same reference signs throughout the description which follows.

[0036] According to a particular and non-limiting example of embodiment of the present invention, the light intensity of a VTH system of a vehicle is adapted progressively as a function of the continuous duration of night driving of the vehicle and of a light intensity reduction chart, based on the capacities of the human eye to adapt to darkness. The eye of a driver of the vehicle traveling at night is then solicited by a decreasing light intensity as the journey progresses, thus avoiding any discomfort or glare for the driver and limiting visual fatigue. Road safety is thus improved because the driver remains vigilant to road events. In addition, the driver no longer has to manually and blindly manage the level of light intensity of the HUD system, which can be dangerous when the adjustment is made at night.

[0037] [Fig.l] schematically illustrates the projection of images in a vehicle 10, according to a particular and non-limiting exemplary embodiment of the present invention.

[0038] [Fig.l] shows a view of the interior of the vehicle 10, in particular of the front part of its passenger compartment comprising in particular a steering wheel, a dashboard, and a windshield 100.

[0039] According to the present invention, the vehicle 10 corresponds for example to a vehicle with a thermal engine, with electric motor(s) or even a hybrid vehicle with a thermal engine and one or more electric motors. The vehicle thus corresponds for example to a land vehicle, for example an automobile, a truck, a bus.

[0040] The vehicle 10 carries a VTH system described in relation to [Fig.4].

[0041] The vehicle 10 also carries a device for controlling an intensity light of the VTH system described in relation to [Fig.5].

[0042] The vehicle 10 also has an exterior brightness sensor configured to obtain data on the exterior brightness of the vehicle 10. This data or part of it is notably used for controlling the light intensity of the VTH system.

[0043] The vehicle 10 may also have a clock and / or a chronometer measuring the duration of a journey of the vehicle 10, i.e. a continuous duration between two consecutive stops of the engine of the vehicle 10.

[0044] The vehicle 10 may also be fitted with a navigation system, which uses, for example, geolocation information provided by a satellite positioning system such as the GPS system (Global Positioning System) or the Galileo system. This geolocation information is combined with mapping data, in particular road data, to display the route of the route on a map obtained from the mapping data.

[0045] The VTH system is configured to display an image (or a part of an image) comprising one or more graphic objects by projection, at a given light intensity level, of a light beam carrying image data onto a surface 101 of the windshield 100.

[0046] The surface 101 is for example located above and behind the steering wheel relative to a point of view corresponding to the point of view from which a driver is supposed to look at the road ahead when driving the vehicle 10.

[0047] [Fig-2] schematically illustrates a field of vision associated with a position of driving the vehicle of [Fig.l], according to a particular and non-limiting exemplary embodiment of the present invention.

[0048] [Fig.2] illustrates the front part of the vehicle 10 in a top view. The field of vision 210 is associated with a point of view 21 which corresponds to the point of view from which a driver is supposed to look at the road in front of him when driving the vehicle 10. This point of view 21 is for example positioned in the middle of the driver's seat (front left in the direction of travel of the vehicle 10 according to the particular example of [Fig. 3]), at the location of the driver's head if the driver were sitting in the driver's seat. The point of view 21 is for example positioned in the center of a headrest resting on the driver's seat when the seat is equipped with such a headrest.

[0049] The field of vision 210 extends for example around a main vision axis 211, and covers an area between an upper vertical limit (forming for example an angle of 15° with the axis 211 from the point of view 21), a lower vertical limit (forming for example an angle of 15° with the axis 211 from the point of view 21), a right lateral limit (forming for example an angle of 20 or 25° with the axis 211 from the point of view 21) and a left lateral limit (forming for example an angle of 25 or 30° with the axis 211 from the point of view 21).

[0050] A graphic object 2100 corresponding to an element of a projected image is advantageously projected or displayed within the field of vision 210, to ensure that the driver looks at the road or the environment in front of the vehicle 10 according to this field of vision 210.

[0051] The graphic object 2100 is for example semi-transparent to allow the driver to see the road environment through this graphic object 2100.

[0052] When the display of an image by the VTH system has the objective of alerting the driver of the vehicle 10 to a danger, the graphic object 2100 is for example displayed at the location of an object detected in front of the vehicle 10, for example the vehicle 11 to draw the driver's attention to this detected object. The graphic object 2100 corresponds to a virtual element added by augmented reality by incrustation or superposition of this virtual element on an element of the real world.

[0053] The movement of the graphic object 2100 follows for example the movement of an object detected in front of the vehicle 10, the movement of the detected object corresponding for example to the movement of the detected object, where appropriate, relative to the movement of the vehicle 10. According to a variant, the graphic object 2100 is initially displayed in a first position before following the movement of the detected object.

[0054] A graphic object 2100 may be, for example, representative of parameters or operating status of the vehicle 10 corresponding to all or part of the information following, in all possible combinations:

[0055] - information representing instantaneous speed; and / or

[0056] - information representative of rotation of a motor shaft (also called in tachometer training); and / or

[0057] - information representative of a mileage traveled; and / or

[0058] - information representative of a fuel level or the state of charge of the battery in the case of an electric vehicle; and / or

[0059] - information representative of a temperature of a coolant engine; and / or

[0060] - at least one piece of information representative of a warning indicator (for example, indicator battery charge indicator, engine oil pressure indicator, engine oil or coolant temperature indicator, brake failure indicator, etc.), corresponding for example to a pictogram displayed or taking on a specific color in the event of an alert; and / or

[0061] - at least one piece of information representative of a warning indicator (for example engine oil level indicator, airbag indicator (also called inflatable cushion), brake pad wear indicator, etc.), corresponding for example to a pictogram displayed or taking on a specific color in the event of a warning; and / or

[0062] - at least one piece of information representative of a function signaling indicator operation of an on-board system (positioning light, dipped beam or main beam indicator, hazard warning light indicator, rear window demisting indicator, etc.), corresponding for example to a pictogram displayed or taking on a specific color when the on-board system is put into operation.

[0063] Alternatively, a graphic object 2100 may be, for example, representative of contextual or environmental information of the vehicle 10 corresponding to all or part of the following information, according to all possible combinations:

[0064] - information representative of mapping of the vehicle's environment 10, for example obtained from an on-board navigation system of the vehicle 10 or from a navigation system installed on a mobile communication device (for example a smartphone) connected in wireless communication with the vehicle 10; and / or

[0065] - information representative of navigation of the vehicle 10, for example a route of the route to be followed by the vehicle 10, the current position of the vehicle 10, the speed limit applicable on the portion of road on which the vehicle 10 is traveling; this information is for example obtained from the navigation system on board the vehicle 10 or from the navigation system installed on a mobile communication device; and / or

[0066] - information representative of an object detected in the environment, by example the presence of another vehicle, the presence of a pedestrian or an animal on the road in front of vehicle 10, the presence of a road sign, the presence of a stationary object on the road, the presence of a tunnel entrance, etc.; this or this information is for example obtained from one or more object detection sensors on board the vehicle 10 and for example associated with one or more AD AS systems (from the English "Advanced Driver-Assistance System" or in French "Advanced Driving Assistance System") of the vehicle 10; according to a variant, this information is received from another vehicle or from an infrastructure of a communication network connected to the vehicle 10 in wireless communication according to a V2X communication mode (from the English "vehicle-to-everything"); according to another variant, this information is received from one or more servers of the "cloud" (or "cloud" in French) via a cellular wireless network of the 4G or 5G type; and / or .

[0067] - information representative of an event detected in the environment, by example, information on a disruption on the road, for example an accident, a traffic jam, information on particular climatic conditions which may disrupt traffic (snow, fog, rain, ice); according to one variant, this information is received from another vehicle or from an infrastructure of a communication network connected to the vehicle 10 according to a V2X communication mode; according to another variant, this information is received from one or more servers in the “cloud” (or “cloud” in French) via a 4G or 5G type cellular wireless network.

[0068] [Fig.3] schematically illustrates a display of graphic objects according to a particular and non-limiting exemplary embodiment of the present invention. The image displayed by the VTH system comprises several graphic objects including pictograms representing a speed limit sign and a graphic object representative of the instantaneous speed of the vehicle 10. Another graphic object also represents navigation information, in this case a change of traffic lane within 1.8 km.

[0069] [Fig.4] schematically illustrates a VTH system of the vehicle 10, according to a particular and non-limiting exemplary embodiment of the present invention.

[0070] The VTH system comprises a device or a control unit 31 configured for processing data received from sensors of the vehicle 10 and / or from systems embedded in the vehicle 10 and / or from remote devices connected to the vehicle 10. The control unit 31 is advantageously configured to generate images from the received data.

[0071] The control unit 31 advantageously comprises one or more CPU (Central Processing Unit) and / or GPU (Graphics Processing Unit) type processors associated with a memory. The control unit 31 corresponds for example to a calculator or a combination of calculators.

[0072] The data representative of an image are transmitted to a projector 32 configured to project a light beam representative of the image at a given light intensity level.

[0073] The projector 32 is for example of the “emissive” type and corresponds for example to a laser scanner comprising at least one laser diode, for example three laser diodes to generate three different colors, for example RGB (one diode per RGB color).

[0074] A laser scanner advantageously comprises a diffuser and a scanning unit generating a light beam, which light beam scans the rear face of the diffuser. The scanning unit comprises, for example, a light beam generator associated with a matrix of micromirrors, called DMD (from the English “Digital Micromirror Device”) configured to orient the light beam on the rear face of the diffuser. The DMD comprises a matrix of movable mirrors produced in the form of a microelectromechanical system, called MEMS (from the English “Micro-Electro-Mechanical System”).

[0075] According to another example, the projector 32 is for example of the “light modulation” type and corresponds for example to a display screen, for example an LCD type screen (from the English “Liquid Crystal Display” or in French “Display à cristals liquide”), for example of the TFT type type (from the English “Thin-Film Transistor” or in French “Thin film Transistor”), or an OLED type screen (from the English “Organic Light-Emitting Diode” or in French “Organic electroluminescent diode”).

[0076] The VTH system also comprises a reflective device 33 associated with the projector 32. The reflective device 33 is configured to orient the light beam (emitted by the projector 32 towards the surface 101 for displaying the image in the field of vision of the viewpoint 21).

[0077] According to a variant, the VTH system does not comprise such a reflective device, the projector being arranged so as to project the light beam directly onto the surface 101.

[0078] According to an optional embodiment, the VTH system further comprises optical means (for example an arrangement of optical lenses not shown) configured to focus the image in an image plane.

[0079] The VTH system is for example configured for the display of images such as generated by operations described with regard to figures 1 and 3 and / or by steps of the method described with regard to [Fig.6].

[0080] A process for controlling the light intensity of the projector 32 of the VTH system is advantageously implemented by the vehicle 10 (i.e. by one or more devices on board the vehicle 10).

[0081] In a first operation, data representative of the night driving condition of the vehicle 10 is obtained.

[0082] In a second operation, information in the form of graphic objects is displayed by the VTH system with a level of light intensity depending on said data representative of the night driving condition of the vehicle.

[0083] In a third operation, a continuous driving time of the vehicle is obtained.

[0084] In a fourth operation, a reduction in the level of light intensity is determined as a function of the duration of continuous driving of the vehicle 10 and using a light intensity reduction chart.

[0085] The light intensity reduction chart, also called the “rheostating” chart, is based on human physiognomy and relates a percentage reduction in the light intensity of a light source to a duration of exposure of the human eye to this light source.

[0086] The light intensity reduction chart can be stored in a table of an on-board system of the vehicle 10.

[0087] In a fifth operation, the level of the light intensity of the projector 32 is reduced according to the determined reduction.

[0088] According to a particular and non-limiting exemplary embodiment, the level of light intensity is reduced if the duration of continuous driving of the vehicle 10 is greater than a threshold value.

[0089] According to a particular and non-limiting exemplary embodiment, the level of light intensity is increasingly reduced when the continuous driving time of the vehicle increases.

[0090] According to a particular and non-limiting exemplary embodiment, the data representative of the night driving condition of the vehicle 10 is obtained from a measurement of brightness outside the vehicle 10.

[0091] For example, said measurement is obtained from the on-board brightness sensor of the vehicle 10.

[0092] According to a particular and non-limiting exemplary embodiment, the data representative of the night driving condition of the vehicle is also obtained from time measurement information and / or geolocation information.

[0093] For example, the time measurement information can be obtained from an on-board clock of the vehicle 10 and the geolocation information is obtained from the on-board navigation system of the vehicle 10.

[0094] The coupling of time measurement and geolocation information makes it possible, for example, to recover sunset times according to geographical positions where the vehicle 10 is located and thus determine an intensity level. light source of the VTH system that is adapted to this information.

[0095] According to a particular and non-limiting exemplary embodiment, the duration of continuous driving of the vehicle 10 corresponds to a duration of continuous operation of the vehicle's engine.

[0096] For example, the continuous driving time of the vehicle is obtained from the on-board chronometer of the vehicle 10.

[0097] [Fig.5] schematically illustrates a device for controlling the light intensity of a VTH system, according to a particular and non-limiting exemplary embodiment of the present invention.

[0098] The device 40 corresponds for example to a device on board the vehicle 10, for example a computer.

[0099] The device 40 is for example configured for the implementation of the operations described with regard to figures 1 to 4 and / or the steps of the method described with regard to [Fig.6]. Examples of such a device 40 include, but are not limited to, on-board electronic equipment such as an on-board computer of a vehicle, an electronic calculator such as an ECU (“Electronic Control Unit”), a smartphone, a tablet, a laptop. The elements of the device 40, individually or in combination, can be integrated into a single integrated circuit, into several integrated circuits, and / or into discrete components. The device 40 can be produced in the form of electronic circuits or software (or computer) modules or even a combination of electronic circuits and software modules.

[0100] The device 40 comprises one (or more) processor(s) 401 configured to execute instructions for carrying out the steps of the method and / or for executing the instructions of the software(s) embedded in the vehicle 10. The processor 401 may include integrated memory, an input / output interface, and various circuits known to those skilled in the art. The device 40 further comprises at least one memory 403 corresponding for example to a volatile and / or non-volatile memory and / or comprises a memory storage device which may comprise volatile and / or non-volatile memory, such as EEPROM, ROM, PROM, RAM, DRAM, SRAM, flash, magnetic or optical disk.

[0101] The computer code of the embedded software(s) comprising the instructions to be loaded and executed by the processor is for example stored in the memory 403.

[0102] According to various particular and non-limiting embodiments, the device 40 is coupled in communication with other similar devices or systems and / or with communication devices, for example a TCU (from the English “Telematic Control Unit” or in French “Telematic Control Unit”), for example via a communication bus or through input ports. / dedicated output.

[0103] According to a particular and non-limiting exemplary embodiment, the device 40 comprises a block 402 of interface elements for communicating with external devices. The interface elements of the block 402 comprise one or more of the following interfaces:

[0104] - RF radio frequency interface, for example of the Wi-Fi® type (according to IEEE 802.11), by example in the 2.4 or 5 GHz frequency bands, or Bluetooth® type (according to IEEE 802.15.1), in the 2.4 GHz frequency band, or Sigfox type using UBN radio technology (Ultra Narrow Band), or LoRa in the 868 MHz frequency band, LTE (Long-Term Evolution), LTE-Advanced;

[0105] Data, such as data obtained by sensors, are for example loaded to the device 40 via the interface of the block 402 using a Wi-Fi® network such as according to IEEE 802.11, an ITS G5 network based on IEEE 802.1 lp or a mobile network such as a 4G (or 5G) network based on the LTE (Long Term Evolution) standard defined by the 3GPP consortium, in particular an LTE-V2X network.

[0106] According to another particular and non-limiting exemplary embodiment, the device 40 comprises a communication interface 404 which makes it possible to establish communication with other devices (such as other computers or on-board sensors) via a communication channel 405. The communication interface 404 corresponds for example to a transmitter configured to transmit and receive information and / or data via the communication channel 405. The communication interface 404 corresponds for example to a wired network of the CAN (Controller Area Network) type, CAN FD (Controller Area Network Flexible Data-Rate), FlexRay (standardized by the ISO 17458 standard) or Ethernet (standardized by the ISO / IEC 802-3 standard).

[0107] According to a particular and non-limiting exemplary embodiment, the device 40 can provide output signals to one or more external devices, such as a display screen 406, touch-sensitive or not, one or more speakers 407 and / or other peripherals 408 (VTH system) via output interfaces 409, 410 and 411 respectively. According to a variant, one or other of the external devices is integrated into the device 40.

[0108] [Fig.6] illustrates a flowchart of the different steps of a method for controlling the light intensity of a VTH system, according to a particular and non-limiting exemplary embodiment of the present invention.

[0109] The method is for example implemented by a device on board the vehicle. 10 or by the device 40 of [Fig.5].

[0110] In a first step 51, data representative of the night driving condition of the vehicle is obtained. In a second step 52, information is displayed by the head-up system with a light intensity level depending on said data. In a third step 53, a continuous driving time of the vehicle is obtained. In a fourth step 54, a reduction in the level of light intensity is determined as a function of the duration of continuous driving of the vehicle and using a light intensity reduction chart.

[0111] In a fifth step 55, the level of light intensity is reduced according to the reduction in the level of light intensity determined.

[0112] According to a variant, the variants and examples of the operations described in relation to figures 1 to 5 apply to the steps of the method of [Fig.6].

[0113] Of course, the present invention is not limited to the exemplary embodiments described above but extends to a method for controlling a light intensity of a VTH system which would include secondary steps without thereby departing from the scope of the present invention. The same would apply to a device configured for implementing such a method.

[0114] The present invention also relates to a vehicle, for example an automobile or more generally an autonomous land-based motor vehicle, comprising the device 40 of [Fig.5].

Claims

Claims

1. Method for controlling a light intensity of a head-up vision system in night driving conditions of a vehicle, said method being implemented by a processor, said method comprising the following steps: - obtaining (51) data representative of night driving conditions of the vehicle; - displaying (52) information by the head-up system with a light intensity level dependent on said data; - obtaining (53) a continuous driving time of the vehicle; - determining (54) a reduction in the light intensity level as a function of the continuous driving time of the vehicle and using a light intensity reduction chart relating a percentage reduction in a light intensity of a light source as a function of a duration of exposure of a human eye to said light source;and - reduction (55) of the level of light intensity according to the reduction of the level of light intensity determined.;

2. The method of claim 1, wherein the level of light intensity is reduced if the continuous driving time of the vehicle is greater than a threshold value.

3. A method according to claim 1 or 2, wherein the level of light intensity is increasingly reduced as the continuous driving time of the vehicle increases.

4. Method according to one of the preceding claims, in which said data is obtained from a measurement of brightness outside the vehicle.

5. Method according to claim 4, wherein said data is also obtained from time measurement information and / or geolocation information.

6. Method according to one of the preceding claims, wherein the duration of continuous driving of the vehicle corresponds to a duration of continuous operation of the engine of the vehicle.

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. A computer-readable recording medium on which is en- registered a computer program comprising instructions for carrying out the steps of the method according to one of claims 1 to 6.

9. Device (40) for controlling a light intensity of a head-up vision system in night driving conditions of a vehicle, said device comprising a memory (403) associated with at least one processor (401) configured for implementing the steps of the method according to any one of claims 1 to 6.

10. Vehicle (10) comprising the device (40) according to claim 9.

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