WO2020064762A1

WO2020064762A1 - Device for protecting an optical sensor/transmitter of a driver assistance system for a motor vehicle

Info

Publication number: WO2020064762A1
Application number: PCT/EP2019/075751
Authority: WO
Inventors: Frédéric BRETAGNOL; Marcel Trebouet
Original assignee: Valeo Systèmes d'Essuyage
Priority date: 2018-09-27
Filing date: 2019-09-24
Publication date: 2020-04-02
Also published as: FR3086766A1

Abstract

The invention relates to a device (101) for attaching an optical sensor/transmitter (2) in a rotary protective device (4), the protective device comprising a first sub-assembly (B) defining a protective box (8) suitable for receiving, at least in part, the optical sensor/transmitter (2) and a second sub-assembly (C) comprising a motor (14) configured to rotate the first sub-assembly (B) about an axis of rotation (A1). The attachment device comprises a flange (102) having tabs (106) for attachment, to a fixed support element (32), of the second sub-assembly (C) forming part of a device for axial positioning relative to a reference surface (33) of this support element.

Description

DEVICE FOR PROTECTING AN OPTICAL SENSOR / TRANSMITTER OF A DRIVING ASSISTANCE SYSTEM FOR A MOTOR VEHICLE

The present invention relates to the field of driving assistance and in particular to driving assistance systems, installed on certain vehicles, the driving assistance system possibly comprising an optical sensor / transmitter, such as for example a camera including a lens. More particularly, the invention relates to a protective housing of such an optical sensor / transmitter.

Currently, optical sensors / transmitters and, for example, front, rear or even side vision cameras, equip a large number of motor vehicles. They are notably part of driving assistance systems, such as parking assistance systems, or line crossing detection systems. In order to best detect the obstacles situated all around the vehicle, it is known to install the optical sensors / transmitters of the driving assistance systems on the periphery of the vehicles in different places according to the desired use, for example integrated in the rear or front bumpers, in the side reinforcement strips, or at the rear or front registration plate of the vehicle.

In this case, the optical sensors / transmitters are highly exposed to projections of mineral or organic dirt which can deposit on the corresponding optical surface and thus reduce the efficiency of signal transmission, shooting or detection of 'information, or even make the sensor / transmitter, detector, or camera concerned totally inoperative. In particular in rainy weather, projections of rain and dirt can be observed which can greatly affect the operability of the driving assistance system comprising such an optical sensor / transmitter. It is therefore understood that the optical surfaces of the sensors / transmitters must be cleaned in order to guarantee their good operating condition, and this need is all the more important in the case of an autonomous vehicle, in which the control of the vehicle is carried out via information sent and / or collected by optical sensors / transmitters.

One of the solutions developed provides that an optical sensor / transmitter, and for example a camera, of a driving assistance system is associated with a protection device which comprises a protective housing housing the camera by protecting it from the outdoor environment. The protective housing has an optical element, transparent and arranged opposite the lens of the camera to allow shots. It is the optical element which is in these solutions exposed to the weather and which presents the risk of being soiled, while the optical sensor / transmitter is protected and remains immaculate. The protective housing and the associated optical element are rotated by means of a motor forming part of the protective device. More particularly, the motor is configured to drive the rotation of the protective housing at a speed sufficient to centrifugally remove dirt or water which may be present on the optical element. This ensures, without abundant use of cleaning fluid, that the optical element is always clean and does not interfere with data acquisition.

Another condition necessary for the acquisition of reliable data is, in this optical context in which an additional optical element is placed opposite the optical sensor / transmitter, that the geometrical position of the optical components is reliable on the one hand with respect to a reference surface and on the other hand between them. It is understood that a positioning deviation of a few centimeters, or even millimeters, and / or a few degrees can generate a significant deviation of the light rays, in the case of a camera for example, and a deformation of the acquired image. It is obviously important to pay attention to the position of the components during the installation at the origin of the optical sensor / transmitter in the protection device, and it is equally important to pay attention to this installation when the one of the optical components must be replaced. The present invention falls within this context and aims to propose an alternative to data acquisition assemblies comprising a device for protecting an optical sensor / transmitter, allowing reliable positioning of the optical components with respect to each other. To this end, the subject of the invention is a device for fixing an optical sensor / transmitter in a rotary protection device, the protection device comprising a first sub-assembly delimiting a protection box able to receive at least partially the optical sensor / transmitter and a second sub-assembly comprising a motor configured to rotate the first sub-assembly around an axis of rotation. According to the invention, the fixing device comprises a flange having lugs for fixing to a fixed support element of the second subassembly forming part of a device for axial positioning with respect to a reference surface of this support element.

The fixing device according to the invention makes it possible to ensure the position of the optical sensor / transmitter with respect to a reference surface formed by a fixed support element of the second sub-assembly, with respect to which the first sub-assembly is moreover likely to be placed. In this way, the correct position of the optical components of the data acquisition assembly is ensured and the reliability of the data subsequently used by the driver assistance system is ensured. In one aspect, the protection device is a separate element from the optical sensor / transmitter.

According to an alternative, the protection device is part of the optical sensor / transmitter.

According to different characteristics of the invention, taken alone or in combination, provision may be made for: The flange further has tabs for holding the optical sensor / emitter forming part of a radial positioning device.

The fixing device comprises a plate configured to surround the optical sensor / transmitter and to carry the fixing lugs to the fixed support element and the holding lugs of the optical sensor / transmitter, the plate forming with the fixing lugs the axial positioning to allow the optical sensor / emitter to be pressed against the reference surface of the support element.

The plate is pierced in its center with a through opening to allow passage to a part of the optical sensor / transmitter, the fixing lugs being distributed on either side of this opening as well as the holding lugs, the holding lugs and the fixing lugs being regularly distributed around the opening.

The fixing lugs and the holding lugs extend axially in the same direction from the plate, the fixing lugs extending over a longer distance than the holding lugs.

- The fixing lugs are configured to cooperate with the support element by snap-fastening by elastic deformation.

The fixing lugs comprise at least one bending zone configured to tension the fixing lugs when they cooperate with the support element by snap-fastening by elastic deformation.

- The fixing lugs comprise in the vicinity of their free end a light capable of cooperating with a lug formed on the fixed support element of the second sub-assembly.

The free end of the fixing lugs have an inclined face directed in the direction of the distance from the opposite fixing lug.

- The fixing device comprises a keying means arranged projecting from the plate between a holding tab and a fixing tab and configured to cooperate with a corresponding keying member made on the optical sensor / transmitter. The fixing device is made of a metallic material. The thickness of the fixing device, which can in particular be obtained by stamping a metal sheet, gives its fixing lugs in particular an elastic character.

The invention also relates to a data acquisition assembly for a driving assistance system for a motor vehicle, comprising an optical sensor / transmitter and a protection device inside which the optical sensor / transmitter is at less partially housed, said optical sensor / transmitter being fixed by means of a fixing device as just mentioned. The optical sensor / transmitter has a sensor / transmitter body capable of being pressed against the reference surface formed by the fixed support assembly and a sensor / transmitter head capable of taking the data, the fixing device being configured on the one hand to be in contact with a front face of the optical sensor / emitter forming the junction between the body and the head of the sensor / emitter and on the other hand to cooperate with fixing members integral with the support element and complementary means for fixing the fixing device.

According to a characteristic of the invention, the first sub-assembly and the second sub-assembly are linked by means of reversible holding means.

The invention also relates to a motor vehicle comprising a data acquisition assembly as described above. Other characteristics and advantages of the invention will appear more clearly on reading the following description, given by way of illustrative and nonlimiting example, and of the appended drawings among which:

- Figure 1 shows a front view of a motor vehicle, comprising at its grille, a driving assistance system according to the prior art; - Figure 2 shows schematically and in perspective, a view of a device for protecting an optical sensor / transmitter of a driving assistance system according to the invention, a housing forming part of the protection device being made transparent to make visible the optical sensor / transmitter that it allows to be housed;

- Figure 3 shows in section the protection device illustrated in Figure 2, without the optical sensor / transmitter capable of being housed in the device; - Figure 3bis is a detail of Figure 3, making more particularly visible the reversible holding means fitted to the protection device according to the invention;

- Figure 4 shows an exploded sectional view of the protection device of Figure 3, wherein the protective housing part and a motorized drive part are spaced from each other to facilitate viewing; - Figure 5 shows in perspective the motorized drive part illustrated in Figure 4;

- Figure 6 shows an alternative embodiment of a protection device according to the invention, in which the optical sensor / transmitter on the one hand and the motor configured to allow the driving of the protection device arranged around this sensor / optical transmitter on the other hand are represented this time;

- Figure 7 shows a view similar to that of Figure 3 in which we made visible the optical sensor / transmitter housed in the device and the fixing device of this sensor / optical transmitter according to one aspect of the invention;

- Figure 8 is a perspective view of the fixing device of Figure 7; - Figures 9 and 10 are perspective illustrations, viewed from the front, in which the protective housing has been removed to make visible the fixing device and the optical sensor / transmitter (Figure 9), or the optical sensor / transmitter without the fixing device (figure 10);

- Figure 11 is a perspective illustration, viewed from the rear, of the fixing device of Figure 7 and the support member on which it is adapted to be fixed; and - Figure 12 is a variant of the embodiment of Figure 7, in which the fixing device is implemented with a protective housing which is fixed by welding to the sub-assembly comprising the motor for driving in rotation of this protective case.

In these figures, identical elements have the same references.

The different realizations are examples. Although the description refers to one or more embodiments, this does not necessarily mean that each reference relates to the same embodiment, or that the characteristics apply to a single embodiment. Simple features of different embodiments can also be combined or interchanged to provide other embodiments.

Furthermore, it should be noted that in the description, it is possible to index certain elements, with for example a first element or a second element. In this case, it is a simple indexing to differentiate and name similar, but not identical, elements. This indexing does not imply a priority of one element over another and one can easily interchange such names without departing from the scope of this description. This indexing does not imply an order in time either.

A vehicle 100 is equipped according to the invention with a driving assistance system 1, which comprises at least one optical sensor / transmitter 2 and a protection device 4 arranged around this optical sensor / transmitter. In the example illustrated, it has been more particularly made visible an optical sensor / transmitter 2 formed by a front vision camera disposed in the grille 5 of the vehicle, but it will be understood that what follows in relation to such a sensor / transmitter optics can be implemented for devices also or alternately arranged at the rear or laterally with respect to the vehicle. According to the invention, at least the protection device 4 associated with the optical sensor / transmitter 2 is configured to prevent or limit the appearance of condensation on the optical surfaces of the protection device and / or the optical sensor / transmitter. The optical sensor / transmitter 2 is for example an optical sensor for taking pictures such as a camera. It can be a CCD sensor (for “charged coupled device” in English, ie a charge transfer device) or a CMOS sensor comprising a matrix of miniature photodiodes. According to another variant, without this list being exhaustive, it may be an infrared radiation sensor such as an infrared camera, a light emitter such as a headlight, an optoelectronic device such as a light-emitting diode (LED), a sensor / emitter of electromagnetic radiation such as a Lidar ("Laser, Imaging, Detection And Ranging") or as a Radar ("Radio, Detection And Ranging"). In FIG. 2, the protection device has been shown partially transparent to make the optical sensor / transmitter housed in the protection device visible. The optical sensor / transmitter 2 has an optical surface 6 and an optical axis 7. The optical surface 6 is for example a camera lens, which can include one or more lenses depending on the field of vision and the desired resolution. In order to protect the optical sensor / transmitter 2 from possible splashing of dirt, it is arranged in the protection device 4, comprising a first sub-assembly B and a second sub-assembly C as illustrated in FIGS. 2 to 4.

The first subset B is configured to house at least the part of the optical sensor / transmitter used for the acquisition of images or data. More particularly, the first sub-assembly B comprises a protective casing 8 capable of rotating around this part of the optical sensor / transmitter.

The protective housing 8 has a peripheral wall 9 and a transverse wall 10 disposed perpendicular to the peripheral wall 9 at a first axial end 91 of the latter. These walls participate in delimiting a cavity 11 in which is housed the optical sensor / transmitter, the optical sensor / transmitter can be inserted into the cavity 11 through the opening at the second axial end 92 open. The peripheral wall 9 and the transverse wall 10 are preferably centered around the axis optical 7 of the optical sensor / transmitter 2. In the example illustrated, the peripheral wall 9 is of substantially cylindrical shape.

The protective housing 8 also comprises an optical element 12 formed by a transparent wall and disposed downstream of the optical surface 6 of the optical sensor / transmitter 2. The optical element 12 is arranged on all or part of the transverse wall 10 and this the optical element 12 is advantageously dimensioned so as to cover the entire optical surface 6. In other words, the optical element 12 is arranged in the field of vision of the optical sensor / transmitter 2, the transparent wall making it possible not to harm the effectiveness of the optical sensor / transmitter 2. The optical element 12 can be made in one piece with the protective housing 8. Alternatively, the protective housing 8 and the optical element 12 can be two separate parts secured between them. The transparent wall forming all or part of the optical element 12 can be made of glass or a plastic material such as polycarbonate. The protective housing 8 can be made of any suitable material known to those skilled in the art, preferably from a waterproof material.

By arrangement of the optical element 12 downstream of the optical surface 6, it is understood that the optical element 12 is disposed between the exterior of the vehicle and the optical surface 6 of the optical sensor / transmitter 2, so that the element optical 12 protects the optical surface 6 from possible projections of solid dirt or debris which could damage this optical surface 6. It is therefore a protective element, or more precisely a protective mask for the optical sensor / transmitter 2 , and it is this optical element 12 which is subjected to attacks from the outside, that is to say both water splashes, pollutants, gravel as pollutant deposits or traces of water.

In order to allow the cleaning of the surface of the optical element 12 by centrifugal effect, as described above, the protection device 4 comprises a motor 14 forming a second sub-assembly C. The motor 14 is coupled to the first sub-assembly assembly B, and more particularly to the protective housing 8, so as to rotate the protective housing 8 and therefore the optical element 12 around an axis of rotation A1, coincident with the optical axis 7 of the optical sensor / transmitter 2.

The motor 14 forming the second sub-assembly C is rotatably mounted around an axis of rotation A2 coincident with the axis of rotation Al of the first sub-assembly B, and with the optical axis 7 of the optical sensor / transmitter 2.

The motor 14 comprises a casing, a bottom wall and a peripheral wall of which form a housing inside which are arranged a rotor 22 and a stator 24. The stator 24 is here fixed on an internal face of the peripheral wall of this casing , the rotor 22 being movable in rotation relative to the fixed stator 24.

In the illustrated embodiment, the motor is an internal rotor motor, the rotor 22 rotating inside the stator 24. It will be understood that it may be envisaged that, without departing from the context of the invention, the motor comprises an external rotor.

The protective housing 8 and the associated optical element 12 are integral with the rotor 22 of the motor 14. In the example illustrated, an intermediate connecting piece 26 is disposed between the rotor 22 and the protective housing 8, being integral with each of its longitudinal ends of one and the other of these components. The rotational drive of the rotor 22 via the power supply of the stator 24 allows the intermediate connecting piece 26 to rotate, which rotates the protective housing 8 and the optical element 12 to be cleaned by centrifugal force if applicable.

The motor 14 comprises at least one magnet 28 integral with the rotor 22, and a predefined number of electromagnetic coils 30 mounted on the stator 24 and supplied with current to generate a magnetic field in which this at least one magnet 28 is capable of moving. It should be understood that the motor 14 comprises a control circuit configured to drive and supply the electromagnetic coils 30 and an associated electrical supply harness, not shown here.

In the illustrated embodiment, and as is more particularly visible in FIG. 6, the rotor 22 is arranged around a support element 32 integral with the optical sensor / transmitter 2 and forming a sheath for a bundle of electrical and video connection cables.

The protection device 4, and more particularly at the level of the second sub-assembly C, comprises two bearings 34, 36 to ensure appropriate pivoting of a movable part of the protection device, formed in particular by the rotor 22 of the motor, the housing protection 8 and the optical element 12, relative to a fixed part of the protection device 4, formed in particular by the stator 24 of the motor.

More particularly, with reference to the example illustrated in FIG. 3, the two bearings are arranged one between the support element 32 secured to the optical sensor / transmitter and the intermediate part 26 and the other between this same support element 32 integral with the optical sensor / transmitter and the rotor 22. It is understood that this arrangement is only a nonlimiting example and that the number and the position of the bearings could vary as soon as this allows the rotation of the movable part relative to the fixed part of the protection device. According to the invention, and as is more particularly visible in FIGS. 3 to 4, the protective housing 8 and the rotor 22, here via the intermediate piece 26 secured to the rotor 22, are linked together by reversible holding means 40 .

The reversible holding means 40 comprise at least a first thread 42 produced on the protective housing 8 and a second corresponding thread 44 produced on the intermediate piece 26, or on the rotor 22 in an embodiment where the rotor has a shape such that it is in direct relation with the protective box. More particularly, the first thread 42 forms a thread present on an internal face 90 of the peripheral wall 9 of the protective housing 8. The first thread 42 is produced with a screw pitch complementary to that of the second thread 44. The second thread 44 forms a bore on an external face of the intermediate part

26 integral in rotation with the rotor 22. The intermediate part 26 has a connection portion 46 with the rotor which is extended axially by a central portion of junction 48, and this intermediate piece 26 comprises a flange 50 disposed at the end of this junction portion and which is extended substantially perpendicularly by a cylindrical wall 52 which extends opposite the second sub-assembly C. According to the Invention, the second thread 44 is formed on the external face of the cylindrical wall 52.

The cylindrical wall 52 of the intermediate piece 26 is configured to be fitted in the protective housing 8 at the peripheral wall 9 of the protective housing 8, so as to allow cooperation between the first and the second thread.

More particularly, the internal face of the peripheral wall 9 of the protective housing has a recess at its end so that a first end portion 54 and a second portion can be seen from the edge of the second axial end 92 end 56 of different diameters, the first end portion having a first internal diameter of value greater than the second internal diameter of the second end portion. It is understood that the internal diameters are measured in a direction radial to the axis of rotation of the protective housing.

As illustrated in FIGS. 3 to 4, the first thread 42 is produced on this second end portion of smaller internal diameter. In this way, the first thread 42 is distant from the second axial end 92 of the peripheral wall 9 of the protective housing. By way of example, the first thread 42 and the second axial end 92 are spaced apart by a distance, measured along the axis of rotation Al of the housing, between 5 mm and 25 mm.

The shoulder 58 thus formed between the two end portions advantageously makes it possible to provide a larger internal space at the end of the protective housing 8, in order to allow easier insertion of the protective housing around the cylindrical wall. 52 of the intermediate piece 26, so as to limit the risks of impact and friction between the second thread 44 and the internal face of the wall device 9 of the housing. This limits the risk of early wear of these elements. It should be noted that as is more visible in FIG. 3a, the shoulder has an inclined plane. In order to facilitate insertion guidance, it can be noted in the figures that the edge of the second axial end 92 of the peripheral wall 9 is chamfered on its internal edge.

Correspondingly, the cylindrical wall 52 of the intermediate piece 26 has a first zone 60 and a second zone 62 of different diameters, this time external. More particularly, the external diameter of the first zone is less than the external diameter of the second zone, the second thread 44 being produced on the first zone 60. And a second shoulder 64 is formed between the two zones of the cylindrical wall. The second shoulder 64 has an inclined plane of inclination substantially similar to that of the shoulder 58 formed on the protective housing 8. It is understood that the complementary shape of the shoulders 58, 64 allows the protective housing 8 to be fitted precisely on the intermediate part 26 in order to ensure unconstrained cooperation of the threads between them.

In this way, it is notable that the reversible holding means comprise a device for radial centering of the first sub-assembly relative to the second sub-assembly, which makes it possible to ensure that the radial dimension D illustrated in FIG. 3 is well centered on the axis Al, A2.

FIG. 3a more particularly illustrates a configuration of the second zone 62 according to which two bearings 66, 68 are formed at different heights, that is to say with different external diameters, the two bearings being separated by a groove 70.

The gradual increase in the thickness of the second zone allows progressive alignment of the protective housing on the cylindrical wall during its fitting on the intermediate piece, so that the first and the second thread are perfectly aligned when they are screwed and that this avoids stresses that can degrade the nets. In order to achieve a seal between the rotating protective housing 8 and the intermediate part 26 integral with the rotor 22, the reversible holding means also include a sealing means. As illustrated by way of example, an O-ring 72, for example an elastomer, is disposed in the groove 70 formed in the second zone 62 of the cylindrical wall. The thickness of the O-ring 72 and the depth of the groove 70 are chosen so that on the one hand the O-ring does not protrude too far from the cylindrical wall so as not to be driven longitudinally during the fitting of the protective housing 8 onto the intermediate piece, and so that on the other hand the O-ring protrudes enough to prevent the passage of a fluid between the rotating protective housing and the intermediate piece 26 once assembled.

The cylindrical wall 52 extends from the collar 50 to a smaller radial dimension than the dimension of the radial end of this collar. In this way, the face of the flange facing the cylindrical wall forms a mechanical abutment face 74 around the entire periphery of the intermediate piece 26. As is more particularly visible in the detailed view in FIG. 3b, the face of mechanical stop 74 forms a stop surface against which the protective casing 8 may come into contact when it is screwed onto the intermediate piece 26. In other words, the mechanical stop face 74 forms a stop making it possible to stop the screwing of the protective housing 8 on the intermediate part 26, when the sub-assemblies B, C reach a certain fitting depth. It is understood that in this way, the mechanical abutment face, and here the flange which carries it, form a device for axial positioning of the reversible holding means, in order to respect a theoretical longitudinal dimension L, illustrated in FIG. 3, between the optical element and a reference surface of the second sub-assembly C on which the protective housing is assembled using the reversible holding means.

Thus, according to the invention, the reversible holding means 40 are configured on the one hand to allow the screwing and unscrewing of the protective housing when it is necessary to replace the optical element at the end of the protective housing, and on the other hand to allow a seal between the two components which are screwed together. And advantageously, in a context where the protective housing has at its free end an optical element disposed upstream of the optical sensor / transmitter housed in the protective housing, and therefore in a context where the position of the optical element relative to the optical surface of the optical sensor / transmitter must be as precise as possible, the reversible holding means are configured to allow radial centering, by adjusting the position of the two stages formed respectively on the internal face of the housing and the external face of the intermediate piece, and the axial centering, by the stop of the end of the protective housing against the flange of the intermediate piece.

The reversible holding means of the protection device may include a securing system configured to prevent the protection box 8 from unscrewing from the second sub-assembly C when the protection box is rotated by the motor 14. The system securing may consist of a particular configuration of the direction of rotation of the threads produced respectively on the protective housing and on an element of the second sub-assembly, here the cylindrical wall 52 of the intermediate piece 26. More particularly, it is ensured according to the invention that the motor 14 is configured to pivot the rotor 22 in the same direction of rotation as this direction of rotation of the threads. The securing system may consist of a latching means which is not shown here and which could in particular be arranged at the end of the peripheral wall 9 of the protective housing 8 so as to cooperate with the external face of the cylindrical wall 52, between the groove seal and the shoulder forming the abutment wall.

If necessary, the reversible holding means 40 may consist of the combination of these latching means with the orientation of the same direction of rotation of the threads and rotation of the motor. The protective device 4 may include means for absorbing moisture. The moisture absorption means are present here to prevent or at least limit condensation on the transparent wall forming the optical element 12 integral with this protective housing 8. It is understood that a cleaning system operating by effect centrifugal involves on the one hand difficulties in sealing the cavity in which the camera extends, both with respect to air and humidity, and on the other hand an increase in temperature due to the operation of the engine and therefore a modification of the pressure in the cavity housing this camera, thus amplifying the air circulation, and the entry of humidity, inside the protective housing. It is therefore advantageous to provide, even if they are not illustrated in FIGS. 2 to

5, moisture absorption means, whether they are arranged in the cavity 11, on the rotor 22 or on the optical sensor / transmitter 2. It may for example be advantageous for the moisture absorption means to remain static when the protective housing 8 is pivoted by the motor, so that the moisture absorption means do not participate in modifying the balance of the mass of the housing.

FIG. 6 illustrates an alternative embodiment in which moisture absorption means 76 are arranged on the internal face 90 of the peripheral wall 9 of the protective housing 8. It is advantageous in this variant that the absorption means d humidity are integral with the protective housing in the context of the invention or this protective housing is mounted on the second sub-assembly C via reversible holding means. Thus, each time it is necessary to replace the optical element integral with the protective housing, the new protective housing installed on the second sub-assembly is equipped with unused moisture absorption means and therefore more effective. The moisture absorption means 76 may in particular consist of a specific absorbent material such as magnesium carbonate, and for example upsalite, or any other equivalent porous material. In order to avoid the creation of an imbalance during the rotation of the protective housing, the absorption means are preferably arranged all around the optical sensor / transmitter, around the entire periphery of the internal face of the peripheral wall.

According to the invention, the optical sensor / transmitter 2 is associated with a fixing device 101 which makes it possible to ensure its position in the protection device 4 in which it is at least partially housed.

More particularly, the optical sensor / transmitter is fixed in this protection device by means of a flange 102 participating in forming this fixing device and visible in FIGS. 7 to 9, 11 and 12. The flange 102 has in particular for role of ensuring the longitudinal position and the radial position of the optical sensor / transmitter as will be discussed below.

FIG. 7 illustrates, in a sectional view, such a flange 102 which comprises in particular a plate 104 and fixing lugs 106. The fixing lugs have the function of holding the flange 102 on the support element 32, which is fixed in the protection device and which serves as a reference for positioning the sensor / transmitter in particular. The function of the plate 104 is to cooperate with the head 20 of the optical sensor / transmitter to maintain it in position relative to the support element 32. More particularly, the flange 102 is designed to press the optical sensor / transmitter against a surface of reference 33 of the support element 32. FIG. 8 illustrates a flange according to one aspect of the invention, with the plate and the fixing lugs as previously mentioned. More particularly, the plate 104 is pierced in its center by an opening 108, the opening being configured in shape and in size so as to allow the passage of the head 20 of the optical sensor / transmitter 2 through the plate, such as that is particularly visible in Figure 7. The plate 104 has a front face 110 and an opposite rear face 112, visible in Figure 11 in particular, the front face 110 being turned towards the end of the device. protection fitted with the optical element and the rear face 112 facing the motor when the plate is in place in the protection device.

The flange 102 here comprises two opposite fixing lugs 106, each fixing lug 106 extending from the plate 104, substantially perpendicular thereto, while being turned towards the side of the rear face 112 of the plate. The fixing lugs 106 are said to be opposite in that they extend from opposite edges of the plate 104.

The fixing lugs 106 extend along the body 21 of the optical sensor / transmitter 2 and each has a free end 114 opposite the plate 104.

The flange 102 is made of a metallic material and the thin thickness of the wall participating in forming the plate and the lugs in one piece provide the flange, in particular at the free ends 114 of the fixing lugs, with an elasticity allowing a fixing of the flange 102 on the support element 32 by snap-fitting with elastic deformation.

To this end, the flange 102 comprises at each free end 114 of the fixing lugs a light 116 allowing the insertion and the blocking of a fixing member taking here the form of a lug 118 formed on the periphery of the support element 32. The pins 118 are configured to retain the flange 102 and thus allow the optical sensor / transmitter 2 to be held against the support element 32 by pressing the body 21 of the sensor / transmitter against the reference surface 33 of the support element.

The free ends 114 of the fixing lugs 106 are slightly curved outwards. In other words, the fixing lugs 106 have at their free end an inclined face 119 directed in the direction of the distance from the opposite fixing lug. It will be understood on reading FIG. 7 that this configuration makes it easier to insert the flange 102 towards the support element 32 and the cooperation of the lights forming a latching means on the side of the fixing lugs with the lugs forming latching means on the side of the support element. On the other hand, it offers a means of more ergonomic grip for a user wishing to detach the flange 102 from the support element 32.

Furthermore, in the example illustrated, each fixing lug 106 comprises one or more bending zones 120 in order to facilitate the inflection of said lugs against the optical sensor / emitter 2. These bending zones in particular allow the tensioning of the flange 102 when the latter is snapped onto the support assembly 32, which allows the body 21 of the optical sensor / emitter to be pressed against the reference surface 33 of the support element 32 as well as possible.

FIG. 8 also makes more particularly visible the presence of retaining lugs 122 configured to cooperate with the optical sensor / transmitter in order to maintain it in position. More particularly, in the example illustrated, the plate 104 has a square shape whose four corners have been modified to form a bevel. As may have been specified previously, two of the sides of the plate 104 are respectively extended substantially perpendicularly by a fixing lug 106. The two other sides of the plate are extended substantially perpendicularly by a retaining lug 122, so that the retaining tabs extend in the same direction as the fixing tabs, namely opposite the front face of the plate. As illustrated, the retaining tabs differ from the fixing tabs in that they have a smaller axial dimension than that of the fixing tabs, and in that they consist only of a solid fallen edge, intended to come in press against one side of the optical sensor / transmitter.

As can be more easily understood on reading Figures 9 and 10, in which the flange is visible and then hidden to make visible the body of the optical sensor / transmitter that it covers, the retaining tabs 122 are arranged in order to avoid a lateral shift of the optical sensor / transmitter relative to the flange and therefore relative to the reference surface 33 of the support element 32. By “lateral shift” is meant a displacement of the optical sensor / transmitter in a radial direction with respect to its optical axis 7 and with respect to the axes of rotation A1 and A2 of the protection device in which the described flange is installed.

When the flange is mounted around the head of the optical sensor / transmitter, the plate comes to overlap a front face 124 of the optical sensor / transmitter 2, visible in FIG. 10, forming the junction between the body 21 and the head 20 of the optical sensor / transmitter. Advantageously, the fixing lugs 106 are shaped so that the flange is snapped onto the support element with the plate 104 which is in contact with the front face 124 of the optical sensor / transmitter, as is particularly visible in FIG. 7. In this position, the retaining lugs 122 are arranged on either side of the head 20 of the sensor / transmitter, along an axis perpendicular to the axis defined by the position of the fixing lugs 106 on either side of this head 20 of the sensor / transmitter.

It is thus understood that the optical sensor / transmitter is blocked in a first direction by the presence of the fixing lugs and in a second direction perpendicular by the presence of the holding lugs 122 against a peripheral rim 125 of the front face 124.

These FIGS. 9 and 10 also illustrate that the device for fixing the optical sensor / transmitter in its protection device includes a keying system in order to ensure the correct position of the flange when it is inserted into the device to fix the position of the sensor / transmitter. More particularly, the front face 124 of the optical sensor / transmitter is configured so as to have a chamfer 126 on one of its corners, and the plate 104 of the flange 102 comprises, at the level of the bevels formed at each corner, a fold 128 extending the plate over a distance substantially equal to that of the fallen edges forming the retaining tabs 122. It is understood that there is then only a correct angular position of the flange around the head 20 of the optical sensor / transmitter, namely that in which the keying means carried by the fixing device, namely the fold 128, can come lodge in the keying member made on the optical sensor / transmitter, namely the clearance formed by the chamfer 126.

This coding is particularly interesting because of the mounting configuration of the assembly on the support element. FIG. 11 makes more particularly visible the support element 32 serving as a reference for positioning the flange and for positioning the optical sensor / transmitter. The support element 32 comprises a base 130 of which a first face, not visible here, forms the reference surface 33 mentioned above and whose opposite second face 132 is extended longitudinally by a shank 134 for supporting the motor elements here not shown.

The lugs 118 configured to retain the flange 102 and thus allow the optical sensor / transmitter 2 to be held against the support element 32 are formed in the material of the support element and more particularly on the periphery 136 of the base 130. The lugs 118 have an inclined plane 138 capable of facilitating the elastic deformation of the fixing lugs away from one another and therefore facilitate the insertion of the flange until the lugs penetrate into the openings, one side right of the lugs allowing the clamping in position of the flange on the support element.

The device for fixing the optical sensor / transmitter in its protection device has been described in the foregoing in relation to means for reversibly holding the protection housing to the rest of the protection device. Of course, this fixing device retains the same advantage if the protective housing is fixed otherwise and for example, as in the variant illustrated in FIG. 12, in the case where the protective housing is welded with the flange of the intermediate piece integral with the rotor.

The invention, as just described, achieves the goals it set for itself and allows, by simple means, to ensure the position of an optical sensor / transmitter in a protection device associated rotary in order to minimize errors in acquisition of images due to incorrect positioning of the optical sensor / transmitter relative to the road scene or of the optical sensor / transmitter relative to the optical element of the rotary protection device.

It should be noted that the fixing device according to the invention can be adapted to any type of sensor / transmitter, whether optical, electromagnetic, or even ultrasonic.

It should also be noted that the different variants described above of a protection device according to the invention can be combined together to form a new embodiment not described.

Claims

1. Fixing device (101) of an optical sensor / transmitter (2) in a rotating protection device (4), the protection device comprising a first sub-assembly (B) delimiting a protective housing (8) capable to receive at least partially the optical sensor / transmitter (2) and a second sub-assembly (C) comprising a motor (14) configured to rotate the first sub-assembly (B) around an axis of rotation ( A1), characterized in that the fixing device comprises a flange (102) having fixing lugs (106) to a fixed support element (32) of the second sub-assembly (C) forming part of an axial positioning device relative to a reference surface (33) of this support element.

2. Fastening device according to the preceding claim, characterized in that the flange (102) also has retaining lugs (122) of the optical sensor / transmitter forming part of a radial positioning device.

3. Fastening device according to the preceding claim, characterized in that the flange (102) comprises a plate (104) configured to surround the optical sensor / transmitter (2) and to carry the fixing lugs (106) to the element fixed support (32) and the retaining lugs (122) of the optical sensor / transmitter, the plate (104) forming with the fixing lugs (106) the axial positioning device to allow the plating of the optical sensor / transmitter (2) against the reference surface (33) of the support element.

4. Fastening device according to the preceding claim, characterized in that the plate (104) is pierced in its center with an opening (108) through for allow passage to a part of the optical sensor / transmitter (2), the fixing tabs (106) being distributed on either side of this opening as well as the retaining tabs (122), the retaining tabs and the fixing being regularly distributed around the opening.

5. Fastening device according to one of claims 2 to 4, characterized in that the fixing lugs (106) and the holding lugs (122) extend axially in the same direction from the plate (104), the fixing lugs extending over a longer distance than the holding lugs.

6. Fastening device according to one of the preceding claims, characterized in that the fixing lugs (106) are configured to cooperate with the support element (32) by snap-fastening by elastic deformation.

7. A fixing device according to the preceding claim, characterized in that the fixing lugs (106) comprise at least one bending zone (120) configured to tension the fixing lugs when they cooperate with the support element. (32) by snap-fastening by elastic deformation.

8. Fastening device according to the preceding claim, characterized in that the free end (114) of the fixing lugs (106) have an inclined face directed in the direction of the distance from the opposite fixing lug.

9. Fastening device according to one of the preceding claims, in combination with claim 2, characterized in that it comprises a keying means (128) arranged projecting from the plate (104) between a retaining tab (122 ) and a fixing lug (106) and configured to cooperate with a corresponding keying member (126) produced on the optical sensor / transmitter (2).

10. Fastening device according to one of the preceding claims, characterized in that the first sub-assembly (B) and the second sub-assembly (C) are linked by means of reversible holding means (40).

11. Data acquisition assembly for a driving assistance system (1) of a motor vehicle, comprising an optical sensor / transmitter (2) and a protection device (4) inside which the sensor / optical transmitter is at least partially housed, said optical sensor / transmitter being fixed by means of a fixing device (101) according to one of the preceding claims, characterized in that the optical sensor / transmitter (2) has a sensor / transmitter body (21) capable of being pressed against the reference surface (33) formed by the fixed support assembly (32) and a sensor / transmitter head (20) capable of carrying out data acquisition, the fixing device (101) being configured to be on the one hand in contact with a front face (124) of the optical sensor / transmitter forming the junction between the body and the head of the sensor / transmitter and on the other hand to cooperate with fixative organs ion (118) integral with the support element (32) and complementary to the fixing lugs (106) of the fixing device (101).