Optical sensor module of a motor vehicle

Abstract

The invention relates to an optical sensor module (12) of a motor vehicle, comprising: - an optical sensor (13); - a base (18) supporting the sensor (13); - an optical surface (16) for protecting the sensor, which is supported by the base (18) and covers the sensor (13), the base (18) comprising at least one internal air duct (20) having at least one annular segment (22) which opens around a junction (24) of the optical surface (16) with the base (18), said annular segment (22) of the duct (20) being able to deliver an air flow (F) sweeping over the optical surface (16).

Description

AUTOMOTIVE VEHICLE OPTICAL SENSOR MODULE Technical field of the invention

[0001] The invention relates to a motor vehicle optical sensor module, and a motor vehicle optical sensor assembly implementing such a module. Technical background

[0002] Sensor assemblies are increasingly used for multiple applications in the automotive industry. In addition to widely known applications such as short-range obstacle detection using ultrasonic devices, long-range obstacle detection using radar devices or cameras, there is a desire to develop increasingly precise sensor assemblies to enable refined detection of the vehicle's environment while it is moving. Indeed, the next developments in driver assistance systems or autonomous driving require the ability to reliably and safely detect obstacles or dangerous situations so that the vehicle driver, who wishes to abandon all or part of the driving of the vehicle, can do so with complete confidence.

[0003] To achieve this, optical sensors are increasingly being used. In particular, a growing technology involving the use of LIDAR sensors, an acronym for "light detection and ranging" or "laser imaging detection and ranging," allows distance measurements based on analyzing the properties of a laser light beam reflected back to its emitter.

[0004] The analysis of the data provided by the LIDAR sensors not only makes it possible to determine the position of vehicles or obstacles surrounding the vehicle, but also, by means of trajectory calculation algorithms, to predictively determine the trajectory of vehicles surrounding the transmitting vehicle in order to determine, taking into account the desired trajectory of the transmitting vehicle, whether it risks encountering the trajectory of a surrounding vehicle or object. The determination of these trajectories then makes it possible to automatically correct the trajectory of the transmitting vehicle and thus avoid any risk of collision.

[0005] In a vehicle, sets of sensors including internal optical sensors of the LIDAR type or others, are generally placed on an exterior surface of the bodywork, for example on the front and rear bumpers of the vehicle, locations to which they are subjected to the weather and to the various projections which may result from the parking or movement of the vehicle in an external environment.

[0006] For this, it is essential that sensor assemblies provide protection for their optical sensors and that this protection does not interfere with the measurement that these sensors can perform. It is therefore essential to keep the protection of an optical sensor systematically clean and free of impurities or water drops that could distort the distance measurement performed by this sensor.

[0007] Generally, optical sensors of any type are protected by an optical surface, this optical surface preferably being in the shape of a dome, a spherical cap or an ellipsoid, so as not to provide protection with edges or flat surfaces that could disrupt the operation of the sensor. Such an optical surface also allows for a large field of vision (generally greater than 180°), which implies that its external surface is not only large relative to the size of the sensor assembly but also that a cleaning device cannot be placed in the field of vision of the sensor without disrupting the measurement of this sensor.

[0008] There is therefore a real need for a cleaning device that can clean most, or even the entire, surface of the optical surface without obstructing the field of vision.

[0009] The invention meets this need by providing an air-blast cleaning device that does not interfere with the field of vision of the optical sensor.

[0010] For this purpose, the invention proposes an optical sensor module for a motor vehicle comprising:

[0011] - an optical sensor,

[0012] - a base, carrying said sensor,

[0013] - an optical surface for protecting said sensor, carried by said base and covering said sensor,

[0014] said base comprising at least one internal air duct comprising at least one annular section opening around a junction of said optical surface with the base, said annular section of duct being capable of delivering an air flow licking the optical surface.

[0015] This configuration advantageously allows the optical surface to be bathed in an air flow which allows it to be cleaned and in particular to be freed from impurities and water droplets which could be deposited there. Cleaning the optical surface by the air flow makes it possible to avoid the interruption of the light beams emitted / or received by the sensor, and to avoid refraction phenomena through water droplets which would stagnate on the optical surface.

[0016] According to another characteristic of the invention, the annular section of conduit comprises at least one internal wall carrying flow deflection means capable of shaping the air flow into a swirling flow licking the entire surface of the optical surface.

[0017] This configuration advantageously ensures that the entire surface of the optical surface is swept by the air flow, and in particular a cap of the optical surface furthest from the base which is most likely to be subject to boundary layer separation phenomena from a simple laminar flow. This guarantees the absence of any deposit on the optical surface, even in the areas furthest from the source of the air flow.

[0018] According to other characteristics of the invention:

[0019] - the annular section of conduit is delimited between a first internal tubular wall of the base, and a second internal tubular wall of the base

[0020] - said second internal tubular wall of the base surrounds the first internal tubular wall with a determined clearance,

[0021] - the base comprises a body of which at least a first tubular end section forms the first internal tubular wall of the base,

[0022] - said body houses a coaxial socket,

[0023] - said socket comprises a first tubular end section which is arranged opposite the first tubular end section of the body and which forms the second internal tubular wall of the base,

[0024] - the flow deflection means are carried by an external surface of the first tubular end section of the sleeve,

[0025] - the flow deflection means comprise a plurality of deflectors,

[0026] - said deflectors project from the outer surface of the first tubular end section of the socket,

[0027] - said deflectors extend along the entire length of the first tubular section of the socket,

[0028] - said deflectors are distributed angularly in a uniform manner on said external surface,

[0029] - said deflectors are inclined relative to an axis of the socket,

[0030] - each deflector consists of a single fin.

[0031] - each deflector consists of a pair of parallel fins,

[0032] - the middle lines of the fins are arranged in helicoids,

[0033] - the deflectors have a height between 25 and 75% of the determined clearance,

[0034] - the deflectors determine between them channels each having a width substantially equal to a third of the width of a deflector,

[0035] - the sensor module has between 20 and 50 deflectors,

[0036] - the body comprises a second end section, which is joined to the first end section, and which comprises an air inlet,

[0037] - a second tubular end section of the socket, joined to the first tubular end section of the socket, extends into the second end section of the body,

[0038] - said second tubular end section of the socket is shaped like an ogive,

[0039] - the optical surface is fixed to the first internal tubular wall of the base,

[0040] - the optical surface optical surface is shaped like a spherical cap.

[0041] The invention also relates to a motor vehicle optical sensor assembly comprising an optical sensor module and an air flow generator connected to said annular section of said module. The optical sensor assembly thus forms a self-contained module that can be integrated into a bodywork element of a motor vehicle without having to provide any connections other than those to electrical wiring supplying the flow generator. Brief description of the figures

[0042] Other characteristics and advantages of the invention will appear during the reading of the detailed description which follows for the understanding of which reference will be made to the appended drawings in which:

[0043] is a perspective view of an optical sensor assembly according to the invention;

[0044] is a perspective view of an optical sensor module for the optical sensor assembly of the ;

[0045] is a detailed perspective view of the optical sensor module of the ;

[0046] is a schematic axial sectional view of the flow of an air flow around an optical surface of a first embodiment of an optical sensor module according to the invention;

[0047] is a perspective view of a second embodiment of an optical sensor module according to the invention;

[0048] is a perspective view of a first embodiment of a socket for the optical sensor module of the ;

[0049] is a detailed perspective view of a second embodiment of a socket for the optical sensor module of the ;

[0050] is a schematic perspective view of the flow of an air stream around an optical surface of the optical sensor module according to the second embodiment of the invention with a socket according to Figures 6 or 7.

[0051] is a developed cross-sectional view of an end section of the socket of Figures 6 and 7. Detailed description of the invention

[0052] A motor vehicle optical sensor assembly 10 is shown in accordance with the invention. The sensor assembly 10 essentially comprises an optical sensor module 12 and an air flow generator 14 which is coupled to the module 12.

[0053] The air flow generator 14 which has been shown here on the is constituted by an electric blower which sucks air through an inlet grille 15 and delivers it into the module 12 through an outlet duct 18, but it will be understood that this configuration is not limiting of the invention and that the air flow generator could be constituted by any other means suitable for supplying blown air to the module 12, such as, for example, a duct supplied with air coming from another part of the vehicle. Nevertheless, in the preferred embodiment of the invention, the use of an electric air flow generator 14 allows great flexibility of assembly because it requires only a simple electrical supply.

[0054] As illustrated in Figures 1 and 2, the optical sensor module 12 of a motor vehicle firstly comprises an optical sensor (not shown), which is, for example and in a non-limiting manner of the invention, a LIDAR type sensor. The sensor 13 has been shown schematically in. This sensor is protected by an optical protection surface 16 which is visible in particular in Figures 1 to 3, and which masks the optical sensor in these figures. Preferably, the optical surface optical protection surface 16 does not have edges which could disturb the light beam emitted or returning to the sensor, and for this purpose it has the shape of an ellipsoid or, preferably, a spherical cap.

[0055] The optical sensor module 12 also includes a base 18. This base 18 carries the sensor 13, and the optical protection surface 16.

[0056] According to the invention, as illustrated in Figures 2 to 4, to enable water drops that could result from condensation or splashes of water onto the optical sensor assembly 10 to be removed, or even to clean said optical surface 16, the base 18 comprises at least one internal air duct 20 comprising at least one annular section 22 opening around a junction 24 of the optical surface 16 with the base 18. This annular section 22 of duct 20 is capable of delivering an air flow F licking the optical surface 16, as shown in. The air flow F is supplied to the optical sensor module 12 by the flow generator 14 previously described.

[0057] This configuration is particularly advantageous, because it allows the optical surface 16 to be bathed in the air flow F which allows water drops and other residues to be expelled from its surface without the source of the air flow being in the field of vision FV of the sensor through the optical surface 16. By way of example, the field of vision FV of the sensor has been shown schematically in , and it is preferably greater than 180°, this over 360° of circumference around an axis X of sight of said sensor.

[0058] As illustrated in Figures 1, 3 and 4, the annular section 22 of conduit 20 is delimited between a first internal tubular wall 26 of the base 18, and a second internal tubular wall 28 of the base 18 surrounding the first internal tubular wall 26 with a determined clearance J. The first tubular wall 26 is arranged as close as possible to the optical surface 16. For this purpose, the optical surface 16 is fixed to the first internal tubular wall 26.

[0059] To produce in practice the annular section of conduit 22 without a connecting bridge between the first internal tubular wall 26 and the second internal tubular wall 28, the annular section 22 of conduit 20 is preferably produced in two parts. For this purpose, as illustrated in FIGS. 4 to 6, the base 18 comprises a body 30 of which at least a first tubular end section forms the first internal tubular wall 28 of the base 18. The body 30 houses a coaxial sleeve 32 which has been shown in the. The sleeve 32 essentially comprises a first tubular end section which is arranged opposite the first tubular end section 28 of the body 30 and which forms the second internal tubular wall 26 of the base 18.

[0060] This configuration is generally satisfactory. However, it may occur that, under certain climatic conditions, an end cap 40 of the optical surface 16, delimited by dotted lines on the, sees water droplets persist on its surface. This is due, as illustrated by the, to a phenomenon of detachment of the boundary layer of the flow F in a neighborhood 41 of the cap 40.

[0061] For this purpose, the invention also proposes an improvement making it possible to overcome this drawback.

[0062] To this end, in accordance with the invention, the annular section 22 of conduit comprises at least one internal wall carrying flow deflection means 42 capable of shaping the air flow F into a swirling flow licking the entire surface of the optical surface 16. In the, the flow F flowing over the optical surface 18 is shown in the form of a swirling flow which also bathes the cap 40 previously cited with reference to the and thus makes it possible to eliminate any water droplets on the surface of the optical surface 16.

[0063] The deflection means 42 may take any form, as long as they are housed inside the annular section 22 of duct and carried by an internal wall thereof. They may, for example, be ducts injecting another air flow tangentially into the annular section 22 of duct, this flow being capable of deflecting the air flow F to give it a swirling flow.

[0064] However, in the preferred embodiment of the invention, the deflection means 42 are solid means which are arranged in the annular section 22 of duct. The means 42 are supplied by the air flow F which is injected into this annular section of duct 42 in order to deflect it according to a swirling flow.

[0065] Also, in this preferred embodiment of the invention, the flow deflection means 42 are carried by an outer surface 44 of the first tubular end section 26 of the sleeve 32. As the annular section 22 of conduit opens at the junction 24 of the optical surface 16 with the base 18, this configuration makes it possible to guarantee that the flow F is deflected into a swirling flow enveloping the optical surface 16 as closely as possible and therefore licking it in an optimal manner.

[0066] As illustrated in Figures 5 and 6, the flow deflection means 42 comprise a plurality of deflectors 46 projecting from the outer surface 44 of the first tubular end section 26 of the sleeve 32. These deflectors 46 extend along an entire length L of the first tubular section 26 of the sleeve 32. They are distributed angularly in a uniform manner on the outer surface 44 and they are inclined generally at an angle α relative to an axis A of the sleeve 32, as shown in. It will be noted that here the axis A of the sleeve corresponds substantially to the sighting axis X of the sensor.

[0067] Several embodiments of the deflectors 46 can be envisaged. According to a first embodiment thereof which has been shown in FIGS. 5 and 6, each deflector 46 consists of a single fin.

[0068] Alternatively, as illustrated in the detail view of the, each deflector 46 consists of a pair of parallel fins 46a, 46b. The fins 46a, 46b are separated by a groove 47 which may be substantially of the same diameter as the outer surface 44 of the first tubular section 26.

[0069] Whether the deflectors 46 are made in the form of fins 46 or pairs of fins 46a, 46b, preferably, as can be seen in Figures 5 to 6, the mean lines of the fins 46, 46a, 46b are arranged in helicoids. This configuration is obviously not limiting of the invention and the fins 46 as well as the pairs of fins 46a, 46b could be rectilinear.

[0070] Whatever their embodiment, the deflectors advantageously have a height h preferably between 25 and 75% of the determined clearance J. This configuration has been shown in the developed cross-sectional view of the first tubular section 26 of the sleeve 32, in strong lines with regard to the deflectors 46 consisting of a single fin or in dotted lines with regard to the deflectors 46 consisting of a pair of fins 46a, 46b.

[0071] Furthermore, the deflectors 46, whether they are produced in the form of single fins 46 or pairs of fins 46a, 46b, determine between them on the external surface 44 channels 48 each having a width d substantially equal to a third of a width D of a deflector 46.

[0072] With regard to the number of deflectors 46, the sensor module 12 comprises between 20 and 50 deflectors 46 distributed angularly in a regular manner on the surface 44 of the first tubular section 26. It will therefore be understood that the sensor module 12 comprises between 20 and 50 unit fins 46, or between 40 and 100 fins 46a, 46b forming pairs of fins in pairs.

[0073] To supply air to the conduit section 22, as illustrated in 1a, the body 30 comprises a second end section 50, which is joined to the first end section 28, and which comprises an air inlet opening 52. In 1a, a second end section 50 of substantially parallelepipedal shape has been shown, but it will be understood that this configuration is not limiting of the invention. The second end section 50 comprises an end wall 54 in which the air inlet opening 52 is made, but it will be understood that this configuration is not limiting of the invention and that the air inlet opening could be located on any other wall of the second end section 50 in order to be connected to the flow generator 14 previously described.

[0074] Furthermore, as illustrated in 1a, the sleeve 32 comprises a second tubular end section 56 which is joined to the first tubular end section 26 and which is shaped like an ogive. As illustrated in 1a, this second section 56 extends into the second end section 50 of the body 30. It makes it possible to guide the air flow F along the sleeve 32 so that it reaches the end section 26 and the deflectors 46.

[0075] Regarding the operation of the optical sensor assembly 10, different strategies for using the blower 14 may be used. It may be used intermittently to expel drops of water or dirt that may have deposited on the optical surface 16, or on the contrary continuously to prevent the deposition of these drops of water or dirt.

[0076] The invention therefore makes it possible to optimally protect the optical surface 16 of an optical sensor assembly 10 from water splashes in order to ensure the reliability of the measurement carried out by the optical sensor.

Claims

Module (12) for an optical sensor of a motor vehicle comprising: - an optical sensor (13), - a base (18), carrying said sensor (13), - an optical surface (16) for protecting said sensor, carried by said base (18) and covering said sensor (13), said base (18) comprising at least one internal air duct (20) comprising at least one annular section (22) opening around a junction (24) of said optical surface (16) with the base (18), said annular section (22) of duct (20) being capable of delivering an air flow (F) licking the optical surface (16). Optical sensor module (12) according to the preceding claim, in which said annular section (22) of conduit (20) comprises at least one internal wall carrying flow deflection means (42) capable of shaping the air flow (F) into a swirling flow licking the entire surface of the optical surface (16). Optical sensor module (12) according to one of the preceding claims, in which: said annular section (22) of conduit is delimited between a first internal tubular wall (26) of the base, and a second internal tubular wall (28) of the base (18) surrounding with a determined clearance (J) the first internal tubular wall (26). Optical sensor module (12) according to the preceding claim, wherein: the base (18) comprises a body (30) of which at least a first tubular end section forms the first internal tubular wall (28) of the base (18), said body (30) housing a coaxial sleeve (32), said sleeve (32) comprising a first tubular end section which is arranged opposite the first tubular end section (26) of the body and which forms the second internal tubular wall (28) of the base. Optical sensor module (12) according to the preceding claim, claim 3 being taken in combination with claim 2, in which the flow deflection means (42) are carried by an outer surface (44) of the first tubular end section (26) of the sleeve (32). Optical sensor module (12) according to the preceding claim, wherein:- the flow deflection means (42) comprise a plurality of deflectors (46) projecting from the outer surface (44) of the first tubular end section (26) of the sleeve (32), said deflectors (46) extending along an entire length of the first tubular section (26) of the sleeve (32), being distributed angularly in a uniform manner on said outer surface (44) and being inclined relative to an axis (A) of the sleeve (32). Optical sensor module (12) according to the preceding claim, wherein each deflector (46) consists of a single fin (46). An optical sensor module (12) according to claim 6, wherein each deflector (46) consists of a pair of parallel fins (46a, 46b). Optical sensor module (12) according to one of claims 7 and 8, in which mean lines of the fins (46, 46a, 46b) are arranged in helicoids. Motor vehicle optical sensor assembly (10) comprising an optical sensor module (12) according to any one of the preceding claims and an air flow (F) generator (14) connected to said annular section (22) of said module (12).

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