Motor vehicle optical sensor module

Abstract

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

Description

Technical Field

[0001] This invention relates to an optical sensor module for motor vehicles, and to an optical sensor assembly for implementing such a module for motor vehicles. Background Technology

[0002] Sensor components are increasingly being used in a variety of applications within the automotive industry. Beyond widely known applications such as short-range obstacle detection using ultrasonic devices and long-range obstacle detection using radar or cameras, there is a growing demand for increasingly accurate sensor components to allow for detailed monitoring of the vehicle's environment while it is in motion. Specifically, the future development of advanced driver assistance systems (ADAS) or autonomous driving systems requires the ability to reliably and safely detect obstacles or hazardous situations, enabling drivers to do so with complete confidence when they wish to relinquish control of the vehicle, either fully or partially.

[0003] To achieve this, optical sensors are being used more and more. In particular, a technique that is being increasingly adopted now is the use of LIDAR sensors (LIDAR is an acronym for light detection and ranging or laser imaging detection and ranging), which allows distance to be measured based on the analysis of the characteristics of the laser beam returning to the laser beam emitter.

[0004] Analysis of data transmitted by LiDAR sensors allows not only the location of the vehicle or obstacles around it to be determined, but also the paths of vehicles around the launch vehicle to be predictively determined through path calculation algorithms. This allows for the determination of whether the launch vehicle is likely to encounter surrounding vehicles or objects, taking into account the launch vehicle's expected path. Determining these paths thus enables the automatic correction of the launch vehicle's path, thereby avoiding any risk of collision.

[0005] In vehicles, sensor assemblies, including internal optical sensors (such as LIDAR), are typically placed on the outer surfaces of the vehicle body, such as the front and rear bumpers. In these locations, the sensor assemblies are exposed to harsh weather and various types of splashes that may occur due to parking or the vehicle moving in outdoor environments.

[0006] Therefore, it is crucial for sensor arrays to provide protection for their optical sensors, and it is equally important for such protection to avoid interfering with any measurements these sensors are capable of performing. Thus, it is essential to keep the protective devices for the optical sensors systematically clean and protected from impurities or water droplets (which can distort distance measurements performed by the sensors).

[0007] Typically, optical sensors, regardless of their type, are protected by an optical surface, preferably dome-shaped, spherical, cap-shaped, or elliptical, so that the protective device has no edges or flat surfaces—edges or flat surfaces that could interfere with the operation of the sensor. This optical surface further allows for the benefit of a large field of view (typically greater than 180°), meaning that its outer surface is not only relatively large compared to the size of the sensor assembly, but also that placing the cleaning device within the sensor's field of view inevitably interferes with the measurements performed by the sensor.

[0008] Therefore, what is truly needed is a cleaning device that allows most or even all of the optical surface to be cleaned without obstructing the field of view of the optical surface. Summary of the Invention

[0009] This invention addresses this need by providing an air-blowing cleaning device that does not interfere with the field of view of an optical sensor.

[0010] Therefore, the present invention proposes an optical sensor module for motor vehicles, comprising: - Optical sensors, - Base, which supports the sensor. - An optical surface that protects the sensor; the optical surface is supported by the base and covers the sensor. The base includes at least one internal air duct, the at least one internal air duct including at least one annular section, the at least one annular section being open around the junction of the optical surface and the base, the annular section of the air duct being capable of conveying an airflow sweeping across the optical surface.

[0011] This configuration advantageously allows the optical surface to be immersed in an airflow, thereby enabling the cleaning of the optical surface and, in particular, removing dirt and water droplets that may have deposited on it. Cleaning the optical surface with an airflow not only prevents interruption of the light beam emitted / received by the sensor but also avoids refraction caused by water droplets (which would otherwise remain on the optical surface).

[0012] According to another feature of the invention, the annular section of the air duct includes at least one inner wall supporting a flow guiding device capable of shaping the airflow into a vortex sweeping across the entire range of the optical surface.

[0013] This configuration advantageously allows airflow to sweep across the entire range of the optical surface, particularly across the cap of the optical surface, which is located furthest from the base and is most likely to show the separation of the boundary layer of simple laminar flow. This ensures that no deposits are formed on the optical surface, even in the region furthest from the source of the airflow.

[0014] Other features according to the invention: - The annular section of the air duct is defined between the first inner tubular wall of the base and the second inner tubular wall of the base. - The second inner tubular wall of the base surrounds the first inner tubular wall by defining a gap. - The base includes a body, at least a first tubular end section of the body forming a first inner tubular wall of the base. - The body houses a coaxial bushing. - The bushing includes a first tubular end section, which is arranged facing the first tubular end section of the body and forms the second inner tubular wall of the base. - The flow guiding device is supported by the outer surface of the first tubular end section of the bushing. - The flow guiding device includes multiple deflecting elements. - The steering element protrudes from the outer surface of the first tubular end section of the bushing. - The steering element extends the entire length of the first tubular section of the bushing. - The steering elements are evenly distributed at an angle on the outer surface. - The steering element is inclined relative to the axis of the bushing. - Each steering element consists of a single fin. - Each steering body consists of a pair of parallel fins. - The centerline of the fins is arranged on the helical body. - The height of the steering body is between 25% and 75% of the defined clearance. - Channels are defined between the steering elements, each channel having a width substantially equal to one-third of the width of the steering element. - The sensor module includes between 20 and 50 steering elements. - The body includes a second end segment adjacent to the first end segment and includes an air inlet. - The second tubular end section of the bushing is adjacent to the first tubular end section of the bushing, and the second tubular end section of the bushing extends into the second end section of the body. - The second tubular end section of the bushing is pointed and arched. - The optical surface is fixed to the first inner tubular wall of the base. - The optical surface is spherical cap-shaped.

[0015] The present invention also relates to an optical sensor assembly for a motor vehicle, comprising an optical sensor module and an airflow generator connected to the annular section of the module. Thus, the optical sensor assembly forms a standalone module that can be integrated into a component of the vehicle body without any connections, except for wiring for powering the airflow generator. Attached Figure Description

[0016] Further features and advantages of the invention will become clear from the following detailed description, which will be more clearly understood with reference to the accompanying drawings, in which: [ Figure 1 ] Figure 1 This is a perspective view of the optical sensor assembly according to the present invention; [ Figure 2 ] Figure 2 It is used for Figure 1 A three-dimensional view of the optical sensor module of the optical sensor assembly; [ Figure 3 ] Figure 3 yes Figure 2 A detailed 3D view of the optical sensor module; [ Figure 4 ] Figure 4 This is a schematic diagram of an axial cross-section showing the manner in which airflow flows around the optical surface of a first embodiment of the optical sensor module according to the present invention; [ Figure 5 ] Figure 5 This is a perspective view of a second embodiment of the optical sensor module according to the present invention; [ Figure 6 ] Figure 6 It is used for Figure 5 A perspective view of a first embodiment of the bushing of an optical sensor module; [ Figure 7 ] Figure 7 It is used for Figure 5 A perspective view detailing a second embodiment of the bushing for the optical sensor module; [ Figure 8 ] Figure 8 The airflow surrounds the second embodiment of the invention having according to Figure 6 or Figure 7 A schematic three-dimensional diagram showing the flow pattern of the optical surface of the optical sensor module in the bushing.

[0017] [ Figure 9 ] Figure 9 yes Figure 6 and Figure 7 The developed cross-sectional view of the end section of the bushing. Detailed Implementation

[0018] Figure 1 An optical sensor assembly 10 for a motor vehicle, manufactured according to the present invention, is shown. The sensor assembly 10 essentially includes an optical sensor module 12 and an airflow generator 14 coupled to the module 12.

[0019] Here Figure 1 The airflow generator 14 already shown includes an electric fan that draws in air via an inlet grille 15 and delivers that air to module 12 via an outlet duct 18. However, it should be understood that the invention is not limited to this configuration, and the airflow generator may include any other means capable of delivering blown air to module 12, such as ducts supplying air from another part of the vehicle. However, in a preferred embodiment of the invention, the use of an electric airflow generator 14 provides great flexibility in terms of installation, as only a simple power supply is required.

[0020] like Figure 1 and Figure 2 As illustrated, the motor vehicle optical sensor module 12 first includes an optical sensor (not shown), which is, for example and in a manner that does not limit the invention, a LIDAR type sensor. Figure 3 Sensor 13 has been schematically shown. This sensor is protected by a protective optical surface 16, which is particularly... Figures 1 to 3 As can be seen in these figures, the protective optical surface covers the optical sensor. Preferably, the protective optical surface 16 has no edges (edges would pose a risk of interfering with the beam emitted by the sensor or the beam returning to the sensor), and for this purpose, the protective optical surface is elliptical in shape or preferably spherical in shape.

[0021] The optical sensor module 12 also includes a base 18. The base 18 supports the sensor 13 and the protective optical surface 16.

[0022] According to the present invention, such as Figures 2 to 4 As illustrated, to allow for the removal of water droplets that may be caused by condensation, sprayed onto the optical sensor assembly 10, or even generated during the cleaning of the optical surface 16, the base 18 includes at least one internal air duct 20. This internal air duct includes at least one annular section 22 that opens around the junction 24 between the optical surface 16 and the base 18. The annular section 22 of the air duct 20 is capable of conveying an airflow F that sweeps across the optical surface 16, such as... Figure 4 As shown in the diagram, the airflow F is delivered to the optical sensor module 12 via the flow generator 14 described above.

[0023] This configuration is particularly advantageous because it allows the optical surface 16 to be immersed in the airflow F, thereby allowing water droplets and other residues to be expelled from the surface of the optical surface, and the source of the airflow is not within the sensor's field of view FV passing through the optical surface 16. For example, Figure 1 The field of view (FV) of the sensor has been schematically shown, and preferably the field of view is greater than 180° over a 360° circumference around the sensor's visual axis X.

[0024] like Figure 1 , Figure 3 and Figure 4 As illustrated, the annular section 22 of the air duct 20 is defined between the first inner tubular wall 26 of the base 18 and the second inner tubular wall 28 of the base 18, the second inner tubular wall surrounding the first inner tubular wall 26 with a defined gap 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 fastened to the first inner tubular wall 26.

[0025] In practice, in order to produce an annular section 22 of the air duct 20 without connecting bridges between the first inner tubular wall 26 and the second inner tubular wall 28, the annular section 22 of the air duct 20 is preferably composed of two parts. Therefore, as... Figures 4 to 6 As illustrated, the base 18 includes a body 30, at least a first tubular end section of which forms a first internal tubular wall 28 of the base 18. The body 30 accommodates a coaxial bushing 32. Figure 6 The coaxial bushing has already been shown. The bushing 32 basically includes a first tubular end section that is arranged facing the first tubular end section 28 of the body 30 and forms the second inner tubular wall 26 of the base 18.

[0026] This configuration is generally satisfactory. However, it is possible that under certain climatic conditions, the end cap 40 of the optical surface 16 (made by...) Figure 3 Water droplets are seen continuously on the surface (defined by the dashed line in the diagram). This is due to the boundary layer of flow F separating in region 41 adjacent to the cap 40, as... Figure 4 As shown in the diagram.

[0027] Therefore, the present invention also provides an improvement that overcomes this disadvantage.

[0028] Therefore, according to the present invention, the annular section 22 of the air duct includes at least one inner wall that supports a flow guiding device 42 capable of shaping the airflow F into a vortex that sweeps across the entire range of the optical surface 16. Figure 8 This illustrates the effect when a vortex is used (the vortex will also be referenced above). Figure 3The cap 40 mentioned above is immersed in the way that the flow F flows through the optical surface 18, and thus makes it possible to remove any water droplets from the surface of the optical surface 16.

[0029] The airflow guiding device 42 can take any form, as long as it is housed within the annular section 22 of the air duct and supported by the inner wall of the annular section. The airflow guiding device can, for example, take the form of an air duct that tangentially injects another airflow into the annular section 22, which is capable of deflecting the airflow F to create a vortex.

[0030] However, in a preferred embodiment of the invention, the airflow guiding device 42 is a solid device arranged in the annular section 22 of the air duct. The device 42 is supplied with an airflow F, which is injected into the annular section 42 of the air duct to deflect the airflow and form a vortex.

[0031] Furthermore, in this preferred embodiment of the invention, the flow guiding device 42 is supported by the outer surface 44 of the first tubular end section 26 of the bushing 32. Since the annular section 22 of the air duct is open at the junction 24 of the optical surface 16 and the base 18, this configuration ensures that the flow F is deflected to form a vortex that encloses the optical surface 16 as tightly as possible and thus sweeps across the optical surface optimally.

[0032] like Figure 5 and Figure 6 As illustrated, the flow guiding device 42 includes a plurality of deflecting elements 46 that protrude from the outer surface 44 of the first tubular end section 26 of the bushing 32. The deflecting elements 46 extend the entire length L of the first tubular section 26 of the bushing 32. These deflecting elements are uniformly angled on the outer surface 44, and are generally inclined at an angle α relative to the axis A of the bushing 32, such as... Figure 6 As shown in the diagram. It should be noted that here, the bushing's axis A substantially corresponds to the sensor's line of sight X.

[0033] Several embodiments of the steering body 46 can be conceived. According to the first embodiment of the steering body ( Figure 5 and Figure 6 (As shown in the first embodiment), each steering body 46 includes a single fin.

[0034] As a variant, such as Figure 7 As illustrated in the detailed view, each deflector 46 includes a pair of parallel fins 46a, 46b. The fins 46a, 46b are separated by a groove 47, the diameter of which may be substantially the same as the outer surface 44 of the first tubular section 26.

[0035] Regardless of whether the steering body 46 takes the form of fins 46 or preferably fin pairs 46a, 46b (e.g. Figures 5 to 6 As can be seen in the diagram, the centerlines of fins 46, 46a, and 46b are all arranged on the helical body. Clearly, the invention is not limited to this configuration, and fins 46 and fin pairs 46a and 46b can be straight lines.

[0036] Regardless of the embodiment, the height h of the steering body is advantageously between 25% and 75% of the defined gap J. This configuration has been shown in the developed cross-sectional view of the first tubular section 26 of the bushing 32, shown in solid lines when discussing a steering body 46 comprising a single fin, or in dashed lines when discussing a steering body 46 comprising a pair of fins 46a, 46b.

[0037] Furthermore, the deflector 46 (whether in the form of a single fin 46 or a pair of fins 46a, 46b) defines channels 48 on its outer surface 44 between them, each of which has a width d that is substantially equal to one-third of the width D of the deflector 46.

[0038] Regarding the number of steering elements 46, the sensor module 12 includes between 20 and 50 steering elements 46, which are regularly angled and distributed on the surface 44 of the first tubular section 26. Therefore, it should be understood that the sensor module 12 includes between 20 and 50 individual fins 46, or between 40 and 100 fins 46a, 46b arranged in pairs to form fin pairs.

[0039] In order to supply air to duct section 22, such as Figure 5 As illustrated, the body 30 includes a second end section 50 adjacent to the first end section 28 and includes an air inlet 52. Figure 5 The second end section 50, which is substantially parallelepiped in shape, is shown, but it should be understood that the invention is not limited to this configuration. The second end section 50 includes an end wall 54 in which an air inlet 52 is formed, but it should be understood that the invention is not limited to this configuration, and the air inlet may be located on any other wall of the second end section 50 for connection to the aforementioned flow generator 14.

[0040] In addition, such as Figure 6 As illustrated, bushing 32 includes a second tubular end section 56 that is adjacent to the first tubular end section 26 and is a pointed arch. Figure 5 As illustrated, the second section 56 extends into the second end section 50 of the body 30. This second section guides the airflow F along the bushing 32 so that the airflow reaches the end section 26 and the deflector 46.

[0041] Various strategies can be employed to operate the optical sensor assembly 10 using the flow generator 14. The flow generator can be used intermittently to remove water droplets or dirt that have been deposited on the optical surface 16, or it can be used continuously to prevent the deposition of such water droplets or dirt.

[0042] Therefore, the present invention enables optimal protection of the optical surface 16 of the optical sensor assembly 10 from water splashes, so as to ensure the reliability of the measurements performed by the optical sensor.

Claims

1. A motor vehicle optical sensor module (12), comprising: - Optical sensor (13). - Base (18), which supports the sensor (13). - An optical surface (16) for protecting the sensor, the optical surface being supported by the base (18) and covering the sensor (13). The base (18) includes at least one internal air duct (20), the at least one internal air duct includes at least one annular section (22), the at least one annular section is open around the junction (24) of the optical surface (16) and the base (18), and the annular section (22) of the air duct (20) is capable of delivering an airflow (F) that sweeps across the optical surface (16).

2. The optical sensor module (12) according to the preceding claim, wherein, The annular section (22) of the air duct (20) includes at least one inner wall that supports a flow guide (42) capable of shaping the airflow (F) into a vortex that sweeps across the entire range of the optical surface (16).

3. The optical sensor module (12) according to any one of the preceding claims, wherein: The annular section (22) of the air duct is defined between the first inner tubular wall (26) of the base and the second inner tubular wall (28) of the base (18), the second inner tubular wall of the base surrounding the first inner tubular wall (26) with a defined gap (J).

4. The optical sensor module (12) according to the preceding claim, wherein: The base (18) includes a body (30) having at least a first tubular end section forming the first inner tubular wall (28) of the base (18), the body (30) accommodating a coaxial bushing (32) having a first tubular end section facing the first tubular end section (26) of the body and forming the second inner tubular wall (28) of the base.

5. The optical sensor module (12) according to the preceding claim, wherein claim 3 is combined with claim 2, wherein, The flow guiding device (42) is supported by the outer surface (44) of the first tubular end section (26) of the bushing (32).

6. The optical sensor module (12) according to the preceding claim, wherein: - The flow guiding device (42) includes a plurality of deflecting bodies (46) that protrude from the outer surface (44) of the first tubular end section (26) of the bushing (32). The steering body (46) extends the entire length of the first tubular section (26) of the bushing (32), and the steering body is evenly distributed at an angle on the outer surface (44) and inclined relative to the axis (A) of the bushing (32).

7. The optical sensor module (12) according to the preceding claim, wherein, Each steering body (46) comprises a single fin (46).

8. The optical sensor module (12) according to claim 6, wherein, Each steering body (46) includes a pair of parallel fins (46a, 46b).

9. The optical sensor module (12) according to any one of claims 7 and 8, wherein, The centerlines of the fins (46, 46a, 46b) are arranged on the helical body.

10. An optical sensor assembly (10) for a motor vehicle, comprising an optical sensor module (12) according to any of the preceding claims and an airflow (F) generator (14) connected to the annular section (22) of the module (12).

Images