Head-up vision system for vehicles and method for controlling such a system

Abstract

The invention relates to a head-up vision (HV) system (2) for vehicles. The HV system comprises an image projector (24) configured to emit a light beam along a principal emission direction (241), an electric motor (25) driving a drive shaft (26) at a predetermined rotational frequency, a plurality of mirrors (21, 22, 23), each fixed to the drive shaft (26), means for synchronizing the projection of the light beam with the rotation of the plurality of mirrors (21, 22, 23), and a transparent or semi-transparent projection surface (102) configured to successively receive the light beam reflected by each mirror of the plurality of mirrors (21, 22, 23). The invention also relates to a method for controlling the HV system. Figure 2

Description

Title of the invention: Head-up vision system for vehicles and method for controlling such a system technical field

[0001] The invention relates to head-up display (HUD) systems for vehicles, particularly but not exclusively for motor vehicles. The invention also relates to a method for controlling such an HUD system. The invention further relates to a system and a method for displaying images in multiple image planes. Technological background

[0002] Some modern vehicles are equipped with a head-up display system, also called a head-up display system, which displays information useful for driving the vehicle at the driver's eye level, for example on a transparent or semi-transparent strip mounted on the dashboard behind the steering wheel. Such a head-up display system is described, for example, in document WO2013 / 189808 A, published on December 27, 2013.

[0003] Head-up display systems are known to be configured to display information on a single plane at a given depth, generally behind the windshield from the driver's point of view. Such systems are known as single-plane head-up display systems, with all content displayed via the HUD being shown on the same image plane.

[0004] Multiplane head-up vision systems are also known, that is to say, systems configured to allow the display of images in different image planes, at different depths relative to the driver.

[0005] Several hardware architectures exist for multiplane VTH systems. For example, some of these VTH systems include several projectors oriented differently with respect to a mirror, each projector projecting an image onto a specific image plane different from that of the other projectors. Other multiplane VTH systems include several projectors, each associated with a mirror, or a single projector projecting images onto an array of aligned mirrors, each individually controlled in rotation. The architecture of these multiplane VTH systems is complex, expensive, and bulky. Summary of the present invention

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

[0007] An object of the present invention is, for example, to propose a multiplanar VTH system with a simplified architecture and a reduced footprint.

[0008] According to a first aspect, the present invention relates to a head-up vision system for vehicles, referred to as a HV system, the HV system comprising: - an image projector configured to emit a beam of light along a main emission direction; - an electric motor driving a motor shaft connected to the electric motor, the motor shaft rotating around an axis of rotation at a determined rotational frequency; - a plurality of mirrors comprising at least 3 mirrors each fixed to the drive shaft, the centers of the mirrors of the plurality of mirrors being arranged so as to form a circle of determined radius centered on the axis of rotation, the centers of the mirrors being distributed uniformly around the axis of rotation and receiving the light beam in turn, a plane of a reflective surface of each mirror of the plurality of mirrors forming a determined angle with the principal direction when the principal direction of emission reaches the center of each mirror, the determined angle being different for each mirror of the plurality of mirrors; - means of synchronizing an image projection by the image projector and rotating the plurality of mirrors; and - a transparent or semi-transparent projection surface configured to successively receive the light beam reflected by each mirror of the plurality of mirrors.

[0009] The use of several mirrors fixed to the same drive shaft, which rotates these mirrors, reduces the size and cost of the VTH system. The mirrors are rotated by a single electric motor, and the images to be displayed are projected onto the mirrors by a single image projector. The projection of the images onto the mirrors is synchronized with the rotation of the drive shaft so that the projector projects the expected image onto the mirror in question, which is associated with a particular image plane. The multi-plane appearance of the VTH system is achieved by varying the angle between each mirror and the principal direction of emission of the light beam emitted by the image projector.

[0010] According to one variant, the determined angle varies according to a monotonically increasing function from one mirror to another while traversing the circle in a determined direction of travel.

[0011] According to a further embodiment, the image projector is configured to project a determined image from a sequence of images onto each mirror of the plurality of mirrors in a manner synchronized with the rotation of the plurality of mirrors around the axis of rotation, the image determined being different for each mirror of the plurality of mirrors.

[0012] According to another variant, the determined image is displayed in a determined image plane at a determined distance from a viewpoint corresponding to a driving position of the vehicle, the determined image plane being associated with each mirror, the image plane being different for each mirror of the plurality of mirrors.

[0013] According to yet another variant, the plurality of mirrors is arranged so that the image planes associated with the plurality of mirrors are aligned along a principal direction of display of the image sequence of a field of vision associated with the viewpoint.

[0014] According to yet another variant, the determined frequency is greater than 50 Hz.

[0015] According to yet another variant, the VTH system further comprises means balancing of an assembly comprising the plurality of mirrors, the drive shaft and means for fixing the plurality of mirrors to the drive shaft.

[0016] According to another variant, the synchronization means include a hall effect sensor.

[0017] According to a second aspect, the present invention relates to a vehicle, for example of the automobile type, comprising a VTH system as described above according to the first aspect of the present invention.

[0018] According to a third aspect, the present invention relates to a method for controlling a VTH system as described according to the first aspect of the present invention, the method comprising the following steps: - control of an electric motor of the VTH system to drive a drive shaft around an axis of rotation at a predetermined rotational frequency, a plurality of mirrors comprising at least 3 mirrors being fixed to the drive shaft, the centers of the mirrors of the plurality of mirrors being arranged so as to form a circle of a predetermined radius centered on the axis of rotation, the centers of the mirrors being uniformly distributed around the axis of rotation; and - control of an image projector of the VTH system to project a light beam along a main emission direction in a manner synchronized with the rotation of the plurality of mirrors so that the mirrors of the plurality of mirrors receive in turn said light beam, a plane of a reflective surface of each mirror of the plurality of mirrors forming a determined angle with the main direction when the main emission direction reaches the center of each mirror, the determined angle being different for each mirror of the plurality of mirrors, a transparent or semi-transparent projection surface successively receiving the light beam reflected by each mirror of the plurality of mirrors.

[0019] According to a fourth aspect, the present invention relates to a control device for a VTH system as described according to the first aspect of the present invention, the device comprising a memory associated with a processor configured for the implementation of the steps of the process according to the third aspect of the present invention.

[0020] According to a fifth aspect, the present invention relates to a computer program which includes instructions adapted for carrying out the steps of the process according to the first aspect of the present invention, in particular when the computer program is executed by at least one processor.

[0021] Such a computer program may use any programming language, and be in the form of source code, object code, or an intermediate code between source code and object code, such as in a partially compiled form, or in any other desirable form.

[0022] According to a sixth aspect, the present invention relates to a computer-readable recording medium on which is recorded a computer program comprising instructions for carrying out the steps of the process according to the first aspect of the present invention.

[0023] On the one hand, the recording medium can be any entity or device capable of storing the program. For example, the medium can include a storage means, such as a ROM, a CD-ROM or a microelectronic circuit-type ROM, or a magnetic recording means or a hard disk drive.

[0024] On the other hand, this recording medium can also be a transmissible medium such as an electrical or optical signal, such a signal being able to be transmitted via an electrical or optical cable, by conventional or radio frequency, by self-directing laser beam, or by other means. The computer program according to the present invention can, in particular, be downloaded from an Internet-type network.

[0025] Alternatively, the recording medium may be an integrated circuit in which the computer program is incorporated, the integrated circuit being adapted to execute or to be used in the execution of the process in question. Brief description of the figures

[0026] Other features and advantages of the present invention will become apparent from the description of the particular and non-limiting embodiments of the present invention below, with reference to the attached Figures 1 to 4, in which:

[0027] [Fig-1] schematically illustrates part of a vehicle's passenger compartment equipped with a head-up vision system, according to a particular embodiment of the present invention, according to a particular embodiment of the present invention;

[0028] [Fig.2] schematically illustrates the head-up vision system of the vehicle in [Fig.1], according to a first particular and non-limiting embodiment of the present invention;

[0029] [Fig.3] schematically illustrates a control device for the head-up vision system of the vehicle in [Fig.1], according to a second particular and non-limiting embodiment of the present invention;

[0030] [Fig.4] illustrates a flowchart of the different stages of a process for controlling the head-up vision system of the vehicle of [Fig.1], according to a particular and non-limiting example of the present invention. Description of examples of achievements

[0031] A multiplane head-up vision system and a method for controlling such a multiplane head-up vision system will now be described in what follows with joint reference to Figures 1 to 4. The same elements are identified with the same reference signs throughout the description that follows.

[0032] The terms "first," "second" (or "firsts," "seconds"), etc., are used in this document by arbitrary convention to allow for the identification and distinction of different elements (such as operations, means, etc.) implemented in the embodiments described below. Such elements may be distinct or correspond to a single element, depending on the embodiment.

[0033] Fig. 1 schematically illustrates the part of a vehicle 10 passenger compartment incorporating a head-up vision system, according to a particular and non-limiting embodiment of the present invention.

[0034] Fig. 1 presents a view of the interior of a vehicle 10, in particular of the front part of the passenger compartment of the vehicle 10 including in particular the steering wheel, the dashboard, and the windscreen 101 of the vehicle 10.

[0035] Vehicle 10 corresponds, for example, to a vehicle with an internal combustion engine, with electric motor(s), or even a hybrid vehicle with an internal combustion engine and one or more electric motors. Vehicle 10 thus corresponds, for example, to a land vehicle, for example a car, a truck, a bus.

[0036] The vehicle 10 advantageously incorporates a head-up display system, hereafter referred to as a HUD (Head-Up Display), configured to display a set of images at different distances or depths from the driver of the vehicle 10, i.e., on different image planes, each image plane having a specific depth associated with it. Each image comprises a set of graphic objects displayed by projection onto a transparent or semi-transparent surface.

[0037] The transparent or semi-transparent surface corresponds, for example, to a strip 102 arranged on the dashboard of the vehicle 10, for example above and behind of the steering wheel relative to a viewpoint corresponding to the viewpoint from which a driver is supposed to look at the road ahead when driving the vehicle 10. According to another example, the transparent or semi-transparent surface corresponds to a determined area of ​​the windscreen 102 onto which the set of images is projected.

[0038] The VTH system corresponds, for example, to an augmented reality (AR) system configured to overlay virtual objects into the driver's field of vision, for example, onto the slat 101 or the windshield 102 of the vehicle 10, so as to superimpose the virtual objects onto the real road scene. The projection of the graphic object images is controlled, for example, by one or more computers of the vehicle 10's embedded network, for example, by the infotainment system computer, known as the IVI (In-Vehicle Infotainment) computer of the vehicle 10.

[0039] The VTH system includes an image projector, for example, embedded in a housing provided in the dashboard 103 of the vehicle 10.

[0040] The images projected onto the slat 101 or the windshield 102 correspond, for example, to a temporal sequence of images displayed successively one after the other on different image planes, in a cyclical manner.

[0041] Taking as an example a sequence of images comprising three images, that is to say a first image, a second image and a third image, the display of the three images is as follows: - the first image is displayed in the foreground with a first associated depth corresponding to a first distance between a viewpoint from which the first image is viewed (i.e., the driver of vehicle 10, also corresponding to the driving position of vehicle 10) and the image plane displaying the first image, the first image including, for example, a first set of information intended for the driver of vehicle 10, for example displayed in the form of first graphic objects included in the first image; then - the second image is displayed on a second image plane with a second associated depth different from the first depth, the second depth being, for example, greater than the first depth, the second image including, for example, a second set of information intended for the driver of vehicle 10 and different from the first set of information, the second set of information taking, for example, the form of second graphic objects included in the second image; then - the third image is displayed on a third image plane with a third associated depth that is different from the first and second depths, the third depth being, for example, greater than the second depth, the third image including, for example, a third set of information intended for the driver of vehicle 10 and different from the first and second sets of information, the third set of information taking, for example, the form of third graphic objects included in the second image; then - the cycle resumes with the display of the first image in the first image plane followed temporally by the display of the second image in the second image plane followed temporally by the display of the third image in the third image plane, and so on until, for example, the image projection is deactivated, for example by a user command made by the driver of vehicle 10.

[0042] The type of information contained in each first image (respectively each second and third image) is identical, although the displayed values ​​may vary. For example, the first image contains a first graphic object corresponding to the current speed of vehicle 10. Each first image thus contains the current speed of vehicle 10, the value of which may vary from one first image to another.

[0043] Of course, the number of images in the image sequence is not limited to 3 but extends to any number, for example any number greater than or equal to 3.

[0044] The information displayed in each of the images in the sequence belongs to a set of information comprising: - information representative of instantaneous speed; - information representing the rotation of a drive shaft (also called tachometer information); - information representing a distance travelled; - information representing a fuel level or the state of charge of the battery in the case of an electric vehicle; - information representative of the temperature of an engine coolant; - at least one piece of information representative of a warning light (for example battery charge indicator, engine oil pressure indicator, engine oil or coolant temperature indicator, brake failure indicator, etc.), corresponding for example to a pictogram that appears or changes color in the event of a warning; - 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 that appears or takes on a specific color in the event of a warning; - at least one piece of information representative of an indicator signal for the operation of an on-board system (positioning light indicator, dipped or main beam indicator, hazard warning light indicator, rear window demister indicator, etc.), corresponding for example to a pictogram that appears or takes on a specific color when the on-board system is put into operation; - representative mapping information of the environment of the vehicle 10, for example obtained from a navigation system on board the vehicle or from a navigation system installed on a mobile communication device (for example a smartphone connected wirelessly to the vehicle 10, or more specifically to the vehicle 10's onboard system including the computer(s) in charge of controlling the projection of the first image and the second image; - representative navigation information for vehicle 10, for example a trace of the route to be followed by the vehicle, the current position of the vehicle, the instantaneous speed of the vehicle, the speed limit applicable on the section of road on which the vehicle 10 is traveling; this information is obtained for example from a navigation system on board the vehicle; - information representative of an object detected in the environment, for example the presence of a vehicle preceding vehicle 10, 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 information is obtained, for example, from one or more object detection sensors on board vehicle 10 and, for example, associated with one or more ADAS (Advanced Driver-Assistance System) systems of vehicle 10;According to one variant, this information is received from another vehicle or from the infrastructure connected to vehicle 10 via wireless communication using a vehicle-to-everything (V2X) communication mode, including vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), and / or vehicle-to-pedestrian (V2P) communication modes; - information representative of an event detected in the environment, for example, information on a disruption on the road, such as an accident, a traffic jam, information on particular weather conditions that may disrupt traffic (snow, fog, rain, ice);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 ADAS systems of the vehicle 10; according to a variant, this information is received from another vehicle or; infrastructure connected to vehicle 10 in wireless communication according to a vehicle-to-everything communication mode, known as V2X; according to another variant, this information is received from one or more servers in the "cloud" (or "nuage" in French) via a 4G or 5G type cellular wireless network.

[0045] The above list is provided for illustrative purposes only and is not exhaustive, as any type of information may be included in one image or another in the image sequence.

[0046] Fig. 2 illustrates a head-up vision system 2, according to particular and non-limiting examples of embodiments of the invention.

[0047] The VTH 2 system is adapted for displaying images from a sequence of images at different image planes, as described previously with reference to [Fig.1].

[0048] Figure 2 illustrates certain elements forming the VTH 2 system. For clarity, the scales of the elements and the differences in scale between the different elements are not to scale. For the same reason of clarity, the elements are represented according to different scales.

[0049] According to the example in [Fig.2], the number of image planes obtained by the VTH system is equal to 3. Of course, the VTH 2 system is suitable for displaying images in a number of image planes greater than 3, for example equal to 4, 5, 6, 10 or more, as described below.

[0050] The VTH 2 system advantageously includes an image projector 24 configured to emit a light beam along a principal emission direction 241. The image information carried by the light beam varies temporally according to the image of the sequence to be projected onto the slat 102 (or, according to a variant, onto the windshield 101) after reflection on a mirror of a plurality of mirrors 21, 22, 23 included in the VTH 2 system. The image projector 24 corresponds, for example, to a single-focal projector, for example of the "emissive" type, the projector 24 corresponding, 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 (from the English "Red, Green, Blue")).

[0051] The VTH 2 system further comprises a plurality of mirrors comprising at least 3 mirrors 21, 22, 23. Of course, the number of mirrors is not limited to 3 but extends to any number greater than 3, for example equal to 4, 5, 6, 10. The number of mirrors equipping the VTH 2 system is equal to the number of image planes desired for the display of the images projected by the image projector 24, each mirror being associated with a particular image plane and different for each mirror of the plurality of mirrors.

[0052] The mirrors 21, 22, 23 are each fixed to a drive shaft 26 which drives the mirrors in rotation around an axis of rotation corresponding to the axis of rotation of the drive shaft 25. The drive shaft 26 is itself driven in rotation by an electric motor 25 included in the VTH 2 system. The electric motor 25 is adapted or configured to drive the drive shaft 26 around the axis of rotation at a determined rotational frequency, the determined frequency being greater than 50 Hz, for example equal to 60, 100 or 200 Hz.

[0053] The mirrors 21, 22, 23 are attached to the drive shaft 26 by any type of attachment known to those skilled in the art. Each mirror is, for example, attached to the outer surface of the drive shaft 26 by one or more parts, for example by one or more rods whose ends are attached by welding or bonding to the mirror and the drive shaft 26, depending, for example, on the material of the mirror and the drive shaft. In one embodiment, the mirrors 21, 22, 23 and the drive shaft 26 form a single part obtained, for example, by machining and / or molding. In this embodiment, the reflective surface of the mirrors is obtained by applying a surface treatment to the parts of the single part provided for this purpose and / or by applying a reflective material to the parts of the single part provided for this purpose, by any method known to those skilled in the art.

[0054] Each mirror 21, 22, 23 is, for example, identical, that is to say, with the same predetermined shape, for example circular or rectangular, and the same dimensions. The centers 211, 221, 231 of the mirrors 21, 22, 23 respectively are arranged to form a circle 220 of a predetermined radius R centered on the axis of rotation of the drive shaft 26. The centers 211, 221, 231 of the mirrors 21, 22, 23 are distributed uniformly around the axis of rotation and receive in turn the light beam emitted by the image projector 24 according to a predetermined time sequence corresponding to the projection sequence of the images to be displayed in the different image planes.

[0055] The angular distribution of the centers 211, 221, 231 on the circle 220 is uniform, that is to say that the angle formed between two radii R associated with two consecutive centers on the circle (according to a determined direction of rotation or of traversal of the circle, clockwise or counterclockwise) is constant for each pair of centers: the angle formed between the radius R associated with the center 211 and the radius R associated with the center 231 is equal to the angle formed between the radius R associated with the center 231 and the radius R associated with the center 221 which is itself equal to the angle formed between the radius R associated with the center 221 and the radius R associated with the center 211.

[0056] According to a particular embodiment, the circle 220 is formed in a plane normal to the axis of rotation of the drive shaft 26.

[0057] The mirrors 21, 22, 23 are arranged around the drive shaft 26 so as to have a specific inclination with respect to the principal emission direction 241 of the image projector 24. Thus, a plane of a reflecting surface of each mirror 21, 22, 23 forms a specific angle with the principal emission direction 241 when the principal emission direction 241 reaches the center 211, 221, 231 of each mirror 21, 22, 23, respectively. The specific angle thus formed is different for each mirror in the plurality of mirrors included in the VTH system, the value of the angle determining the depth of the image plane associated with each mirror.

[0058] For example, for mirror 21, the angle formed between the plane of its reflecting surface and the principal direction of emission is denoted al, as illustrated in [Fig. 2]. For mirror 22, the angle formed between the plane of its reflecting surface and the principal direction of emission is denoted a2 (not illustrated in [Fig. 2]). For mirror 23, the angle formed between the plane of its reflecting surface and the principal direction of emission is denoted a3 (not illustrated in [Fig. 2]). The angles al, a2, and a3 are different from each other, i.e., al a2 a3. The angle a1, a2 and a3 fixes the principal reflection direction of the radiation received from the projector 24 by each mirror 21, 22, 23 respectively along the principal emission direction 241 when the latter reaches the center 211, 221, 231 of each mirror 21, 22, 23 respectively. As illustrated in [Fig.[2] The principal direction of reflection 242 associated with the center 211 of the mirror 21 receiving the radiation from the projector 24 along the principal direction of emission 241 reaching this center 211 strikes the slat 102 at a first point or a first determined area, allowing the display of the first image (of the image sequence) in the first image plane 201. The principal direction of reflection associated with the center 221 of the mirror 22 receiving the radiation from the projector 24 along the principal direction of emission 241 reaching this center 221 strikes the slat 102 at a second point or a second determined area, allowing the display of the second image in the second image plane 202.Finally, the principal direction of reflection associated with the center 231 of the mirror 23 receiving the radiation from the projector 24 along the principal direction of emission 241 reaching this center 231 strikes the slat 102 at a third point or a third determined area, allowing the display of the third image in the third image plane 203.

[0059] The angles a1, a2, and a3 vary, for example, according to a monotonically increasing function from one mirror to another when traversing the circle 220 in a determined direction (for example, clockwise or counterclockwise). The monotonically increasing function corresponds, for example, to a linearly increasing function, which makes it possible to obtain a constant variation in depth between each pair of consecutive image planes (the depth or distance between the first image plane 201 and the second image plane). 202 is equal to the depth or distance between the second image plane 202 and the third image plane 203).

[0060] According to a particular embodiment, the mirrors 21, 22, 23 are arranged so that the image planes 201, 202, 203 associated with each mirror 21, 22, 23, respectively, are aligned along a principal direction 210 of display of the image sequence in the field of vision 200 associated with the viewpoint 20 from which these images are seen by the driver. The images displayed in each image plane 201, 202, 203 are visually superimposed, only the depth (i.e., the distance between the image plane and the viewpoint 20) varying along the image plane 201, 202, 203 when the viewpoint is stationary.

[0061] The VTH 2 system further includes synchronization means (not shown) for synchronizing the projection of images by the image projector 24 and the rotation of the plurality of mirrors, according to the determined rotation frequency of the mirrors 21, 22, 23.

[0062] The synchronization means are implemented, for example, by a control device that controls the rotational frequency of the drive shaft 26 (by controlling the electric motor 25) and the projection of the images by the image projector according to a determined time sequence. Such a device corresponds, for example, to a computer, or a set of computers, of the vehicle's on-board network 2. A hardware embodiment of such a computer is described opposite [Fig. 3]. Synchronization is achieved, for example, via a software module executed and implemented by the control device. According to one embodiment, the synchronization means comprise a Hall effect sensor, with a specific and different magnet associated with each mirror 21, 22, 23, the synchronization between the image projection and the rotation of the mirrors being a function of the data obtained from the Hall effect sensor.According to other examples, the synchronization means include a position reading track for mirrors 21, 22, 23 or a servomotor (i.e., the electric motor 25 is servo-controlled).

[0063] The temporal synchronization between the rotation of the mirrors and the projection of the images of the image sequence makes it possible to obtain (according to a clockwise rotation of the mirrors 21, 22, 23): - the projection of the content of the first image by the projector 24 when the mirror 21 receives the light beam so that the content of the first image is displayed in the foreground image 201, - the projection of the content of the second image by the projector 24 when the mirror 22 receives the light beam so that the content of the second image is displayed in the second image plane 202, and - the projection of the content of the third image by the projector 24 when the mirror 23 receives the light beam so that the content of the third image is displayed in the third image plane 203.

[0064] According to the example above, the image sequence is displayed at a frequency equal to the rotational frequency of the motor shaft 26 multiplied by the number of mirrors. Thus, the projection frequency of the first images is equal to the rotational frequency (for example, 60 Hz), the projection frequency of the second images is also equal to the rotational frequency, as is the projection frequency of the third images.

[0065] According to one particular embodiment, the VTH 2 system further comprises balancing means. These balancing means correspond, for example, to static and dynamic balancing means for an assembly formed by the plurality of mirrors 21, 22, 23, the drive shaft 26, and, where applicable, means for attaching the plurality of mirrors to the drive shaft. These balancing means consist, for example, of one or more counterweights added to the assembly. According to another example, these balancing means are obtained by machining one or more elements of the assembly by removing material from one or more areas of the element(s). The balancing means make it possible to reduce vibrations during the rotation of the drive shaft 26 and the mirrors 21, 22, 23, as well as the noise generated by the rotation of these elements. The balancing means also make it possible to increase the service life of the assembly and thus of the VTH 2 system.

[0066] Figure 3 schematically illustrates a device 3 configured to control a vehicle head-up vision system, for example the HV2 system of vehicle 10, according to specific and non-limiting embodiments of the present invention. The device 3 corresponds, for example, to a device embedded in the vehicle 10, for example a computer.

[0067] Device 3 is, for example, configured to carry out the operations described opposite Figures 1 and 2 and / or the steps of the process described opposite [Fig. 4]. Examples of such a device 3 include, but are not limited to, embedded electronic equipment such as a vehicle's on-board computer, an electronic control unit such as an ECU (Electronic Control Unit), a smartphone, a tablet, or a laptop computer. The elements of device 3, individually or in combination, can be integrated into a single integrated circuit, into several integrated circuits, and / or into discrete components. Device 3 can be implemented in the form of electronic circuits or software (or computer) modules, or a combination of electronic circuits and software modules.

[0068] The device 3 comprises one (or more) processor(s) 30 configured to execute instructions for carrying out the steps of the process and / or for executing instructions from the software embedded in the device 3. The processor 30 may include integrated memory, an input / output interface, and various circuits known to those skilled in the art. The device 3 further comprises at least one memory 31, for example, volatile and / or non-volatile memory, and / or includes a memory storage device that may include volatile and / or non-volatile memory, such as EEPROM, ROM, PROM, RAM, DRAM, SRAM, flash, magnetic disk, or optical disk.

[0069] The computer code of the embedded software(s) including the instructions to be loaded and executed by the processor is for example stored on memory 31.

[0070] According to various particular and non-limiting embodiments, the device 3 is coupled in communication with other similar devices or systems and / or with communication devices, for example a TCU (Telematic Control Unit), for example via a communication bus or through dedicated input / output ports.

[0071] According to a particular and non-limiting embodiment, the device 3 includes a block 32 of interface elements for communicating with external devices. The interface elements of the block 32 include one or more of the following interfaces: - radio frequency RF interface, for example of the Wi-Fi® type (according to IEEE 802.11), for example in the 2.4 or 5 GHz frequency bands, or of the Bluetooth® type (according to IEEE 802.15.1), in the 2.4 GHz frequency band, or of the Sigfox type using UBN (Ultra Narrow Band) radio technology, or LoRa in the 868 MHz frequency band, LTE (Long-Term Evolution), LTE-Advanced; - USB interface (from the English "Universal Serial Bus" or "Universal Serial Bus" in French); - HDMI interface (from the English "High Definition Multimedia Interface", or "High Definition Multimedia Interface" in French); - LIN interface (from the English "Local Interconnect Network", or in French "Réseau interconnecté local").

[0072] According to another particular and non-limiting embodiment, the device 3 includes a communication interface 33 which enables communication with other devices (such as other computers in the embedded system) via a communication channel 330. The communication interface 33 corresponds by example to a transmitter configured to transmit and receive information and / or data via communication channel 330. Communication interface 33 corresponds for example to a wired network of type CAN (from the English "Controller Area Network" or in French "Réseau de contrôlers"), CAN FD (from the English "Controller Area Network Flexible Data-Rate" or in French "Réseau de contrôlers à débit de données flexible"), FlexRay (standardized by the ISO 17458 standard) or Ethernet (standardized by the ISO / IEC 802-3 standard).

[0073] According to a particular and non-limiting embodiment, the device 3 can provide output signals to one or more external devices, such as a projection system 340 (corresponding for example to the projector 24), a drive element 350 (corresponding for example to the electric motor 25) and / or other peripherals 360 (screens, speakers) via output interfaces 34, 35 and 36 respectively. According to a variant, one or more of the external devices is integrated into the device 3.

[0074] Figure 4 illustrates a flowchart of the different steps in a method for controlling a head-up vision system in a vehicle, for example the HV2 system of vehicle 10, according to a particular and non-limiting embodiment of the present invention. The method is implemented, for example, by a control device on board the vehicle 10, for example device 3 in Figure 3.

[0075] In a first step 41, an electric motor of the VTH system is controlled to drive a motor shaft around an axis of rotation at a determined rotation frequency, a plurality of mirrors comprising at least 3 mirrors being fixed to the motor shaft, the centers of the mirrors of the plurality of mirrors being arranged so as to form a circle of determined radius centered on the axis of rotation, the centers of the mirrors being distributed uniformly around the axis of rotation.

[0076] In a second step 42, an image projector is controlled to project a light beam along a principal emission direction in a manner synchronized with the rotation of the plurality of mirrors so that the mirrors of the plurality of mirrors receive said light beam in turn, a plane of a reflective surface of each mirror of the plurality of mirrors forming a determined angle with the principal direction when the principal emission direction reaches the center of each mirror, the determined angle being different for each mirror of the plurality of mirrors, a transparent or semi-transparent projection surface successively receiving the light beam reflected by each mirror of the plurality of mirrors.

[0077] According to one variant, the variants and examples of the operations described in relation to one of Figures 1 and 2 apply to the steps of the process in [Fig.4].

Claims

Demands

1. Head-up vision system (2) for vehicle (10), said HV system, said HV system (2) comprising: - an image projector (24) configured to emit a light beam along a principal emission direction (241); - an electric motor (25) driving a drive shaft (26) connected to the electric motor (25), said drive shaft (26) rotating about an axis of rotation at a determined rotational frequency;- a plurality of mirrors comprising at least 3 mirrors (21, 22, 23) each fixed to said drive shaft (26), the centers (211, 221, 231) of the mirrors (21, 22, 23) of said plurality of mirrors being arranged so as to form a circle (220) of determined radius centered on said axis of rotation, said centers (211, 221, 231) of the mirrors (21, 22, 23) being distributed uniformly around said axis of rotation and receiving in turn said light beam, a plane of a reflectance surface of each mirror (21, 22, 23) of said plurality of mirrors forming a determined angle with said principal direction of emission (241) when said principal direction of emission (241) reaches the center of said each mirror, said determined angle being different for each mirror of said plurality of mirrors; - means for synchronizing a projection of images by said image projector (24) and for rotating said plurality of mirrors (21, 22, 23);and - a transparent or semi-transparent projection surface (102) configured to successively receive said light beam reflected by each mirror of said plurality of mirrors (21, 22, 23).;

2. VTH system according to claim 1, wherein said determined angle varies according to a monotonically increasing function from one mirror to another while traversing said circle (220) in a determined direction of travel.

3. VTH system according to claim 1 or 2, wherein said image projector (24) is configured to project a determined image from a sequence of images onto each mirror of said plurality of mirrors (21, 22, 23) in a manner synchronized with the rotation of said plurality of mirrors (21, 22, 23) about the axis of rotation, the said determined image being different for each mirror of the said plurality of mirrors (21, 22, 23).

4. A method according to claim 3, wherein said determined image is displayed in an image plane (201, 202, 203) determined at a determined distance from a viewpoint (20) corresponding to a driving position of said vehicle (10), said determined image plane (201, 202, 203) being associated with said mirror, said image plane (201, 202, 203) being different for each mirror of said plurality of mirrors (21, 22, 23).

5. A method according to claim 4, wherein said plurality of mirrors (21, 22, 23) is arranged so that the image planes (201, 202, 203) associated with the plurality of mirrors (21, 22, 23) are aligned along a principal direction (210) of display of the image sequence of a field of view (200) associated with said viewpoint (210).

6. VTH system according to any one of claims 1 to 5, wherein said determined frequency is greater than 50 Hz.

7. VTH system according to any one of claims 1 to 6, further comprising means for balancing an assembly comprising said plurality of mirrors (21, 22, 23), said drive shaft (26) and means for fixing said plurality of mirrors to said drive shaft.

8. VTH system according to any one of claims 1 to 7, wherein said synchronization means comprise a hall effect sensor.

9. Vehicle (10) comprising the VTH system (2) according to any one of claims 1 to 8.

10. A method for controlling the VTH system (2) according to any one of claims 1 to 8, said method being implemented by at least one processor and comprising the following steps: - controlling (41) an electric motor of the VTH system to drive a drive shaft about an axis of rotation at a predetermined rotational frequency, a plurality of mirrors comprising at least 3 mirrors being fixed to the drive shaft, the centers of the mirrors of the plurality of mirrors being arranged so as to form a circle of predetermined radius centered on the axis of rotation, the centers of the mirrors being uniformly distributed around the axis of rotation; and - control (42) of an image projector of the VTH system to project a light beam along a principal emission direction in a manner synchronized with the rotation of the plurality of mirrors so that the mirrors of the plurality of mirrors receive in turn said light beam, a plane of a reflective surface of each mirror of the plurality of mirrors forming a determined angle with the principal direction when the principal emission direction reaches the center of each mirror, the determined angle being different for each mirror of the plurality of mirrors, a transparent or semi-transparent projection surface successively receiving the light beam reflected by each mirror of the plurality of mirrors.

Images