Cover for lidar sensor

Abstract

The invention relates to a cover for a lidar sensor, the rear side of the cover in use facing the lidar sensor, and the opposite front side of the cover in use facing the environment of the lidar sensor. The cover includes a carrier layer having a carrier refractive index. Further, the cover includes a first anti-reflection (AR) layer disposed between the carrier layer and the back side of the cover, the first anti-reflection (AR) layer having a first AR refractive index located between the air refractive index and the carrier refractive index. The cover also includes a second AR layer disposed between the carrier layer and the front side of the cover having a second AR refractive index located between the air refractive index and the carrier refractive index.

Description

Technical Field

[0001] The invention relates to a protective cover for a laser radar sensor. Background Art

[0002] The vehicle may include at least one lidar sensor, which is designed to detect sensor data about the environment of the sensor. For example, the lidar sensor may be arranged at the front of the vehicle and is usually subject to different environmental influences during vehicle operation, such as stone impacts, snow, rain, etc., which may cause damage to the lidar sensor. Summary of the invention

[0003] The present invention relates to the technical task of providing reliable protection for a lidar sensor without significantly affecting the sensing properties of the lidar sensor.

[0004] This object is achieved by the independent claim. Advantageous embodiments are further described in the dependent claims. It should be pointed out that the additional features of the dependent claims of the independent claim can form their own invention without the features of the independent claim or in combination with only a subset of the features of the independent claim and independently of the combination of all the features of the independent claim, which invention can become the subject of the independent claim, a divisional application or a subsequent application. This applies in the same way to the technical teachings described in the description, which can form inventions independent of the features of the independent claim.

[0005] According to one aspect, a (protective) cover (or covering device) for a lidar sensor is described. The lidar sensor can be configured to transmit a laser signal in a transmission direction. Furthermore, the lidar sensor can be designed to receive a reflection signal (based on reflection of the laser signal) in a reception direction (opposite to the transmission direction). The laser signal and the reflection signal can have a frequency in the infrared frequency range. The cover described in this document has a relatively high transmittance (e.g. 90% or more) in the frequency range of the lidar sensor.

[0006] When in use, the back side of the cover may face the lidar sensor, and when in use, the opposite front side of the cover may face the environment of the lidar sensor (and face away from the lidar sensor). The transmission direction may extend from the back side to the front side of the cover. The receiving direction may extend from the front side to the back side of the cover.

[0007] The cover comprises a carrier layer (especially a carrier coating) having a carrier refractive index. The carrier layer may comprise a polycarbonate (PC) material, especially consist of a polycarbonate material.

[0008] Therefore, a relatively high transmittance within the frequency range of the lidar sensor can be achieved.

[0009] The cover also includes a first anti-reflection (AR) layer arranged between the carrier layer and the back side of the cover, the first AR layer having a first AR refractive index between the refractive index of air and the refractive index of the carrier. By providing the first AR layer (the refractive index increases stepwise or smoothly through the first AR layer on the path of the laser signal), the reflectivity along the transmission direction can be reduced.

[0010] In addition, the cover comprises a second AR layer arranged between the carrier layer and the front side of the cover, the second AR layer having a second AR refractive index between the refractive index of air and the refractive index of the carrier. By providing a second AR layer (the refractive index increases stepwise or smoothly through the second AR layer on the path of the reflected signal), the reflectivity in the receiving direction can be reduced.

[0011] By means of such a multi-layer structure of the covering, a protective covering can be provided which causes particularly little impairment of the sensor properties of the lidar sensor.

[0012] The first AR refractive index of the first AR layer may increase smoothly or stepwise from the rear side of the cover toward the carrier layer along the transmission direction. Alternatively or additionally, the second AR refractive index of the second AR layer may increase smoothly or stepwise from the front side of the cover toward the carrier layer along the receiving direction. Therefore, the damage to the sensing characteristics of the lidar sensor can be further reduced by protecting the cover.

[0013] The cover, in particular the carrier layer, can be configured so that a lidar sensor (for example, with a weight of 500 g or more) can be fixed on the rear side of the cover and carried by the cover. Thus, a particularly reliable protection of the lidar sensor can be achieved by the cover.

[0014] The cover may include a heating layer, which is designed to heat the surface of the cover, in particular the front side of the cover, for example in order to evaporate liquid on the surface of the cover. The quality of the sensor detection by the lidar sensor can thus be further improved. The heating layer can preferably be arranged between the second AR layer and the carrier layer in order to be able to heat the surface of the front side of the cover particularly effectively and reliably.

[0015] The heating layer can be arranged, in particular embedded, between the carrier film (made of PC material) and the carrier layer. Therefore, a cover with a heating function can be manufactured particularly efficiently. In addition, the heating layer can be reliably protected from environmental influences, thereby providing a particularly sturdy cover.

[0016] The heating layer can include a grid composed of electrically conductive nanotubes. The grid can be energized so that the nanotubes heat up due to the current flow. This can lead to reliable and comprehensive evaporation of the liquid on the surface of the front side of the cover.

[0017] The edge of the grid of nanotubes can surround the heatable surface of the cover. The heatable surface can be adapted to the azimuth and / or elevation range of the detection range of the lidar sensor, so that the surface of the front side of the cover can be heated in the entire detection range of the lidar sensor.

[0018] The grid of nanotubes can be large-meshed and / or the nanotubes can be very small, so that the nanotubes of the grid only cover 5% or less of the heatable surface in total. This can result in the sensor detection of the lidar sensor being only slightly influenced by the cover, in particular the heating layer of the cover.

[0019] The cover may include a protective layer (eg a hard coating) which is arranged between the front side of the cover and the second AR layer and is designed to protect the cover from mechanical and / or chemical environmental influences. Thus, a particularly robust protective cover may be provided for the lidar sensor.

[0020] The cover can include a comfort layer (especially an easy-to-clean coating) on ​​the surface of the front side of the cover, which is provided to facilitate the cleaning of the cover. Therefore, an effective installation of the protective cover in a motor vehicle can be achieved.

[0021] According to another aspect, a (road) motor vehicle (in particular a passenger car, truck, bus or motorcycle) is described, which comprises a protective cover as described in this document. The vehicle also comprises a lidar sensor arranged on the rear side of the cover.

[0022] It should be noted that the devices and systems described in this document can be used not only alone, but also in combination with other devices and systems described in this document. In addition, any aspects of the devices and systems described in this document can be combined with each other in a variety of ways. The features of the claims can especially be combined with each other in various ways. In addition, the features mentioned in brackets should be understood as optional features. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention will be described in detail below with reference to examples.

[0024] Figure 1 illustrates exemplary components of a vehicle; and

[0025] Figure 2 An exemplary multi-layer protective cover for a lidar sensor is shown. DETAILED DESCRIPTION

[0026] As explained at the beginning, this document is concerned with providing reliable protection for LiDAR sensors. In this context, Figure 1 An exemplary vehicle 100 is shown which comprises a lidar sensor 102 which is designed to detect sensor data relating to the environment of the vehicle 100. The lidar sensor 102 transmits a laser signal which is reflected, if necessary, at an object in the environment of the vehicle 100 so that a reflected signal is reflected back to the lidar sensor 102 which can detect and evaluate it. Objects in the environment of the vehicle 100 can thus be identified and located in a reliable and precise manner. The data of the lidar sensor 102 can be evaluated by the control device 101 of the vehicle 100. The (evaluated) data of the lidar sensor 102 can be used to automatically guide the vehicle 100 longitudinally and / or laterally.

[0027] The lidar sensor 102 can be arranged behind a cover 110 in the vehicle 100 in order to protect the lidar sensor 101 from environmental influences. In this case, the cover 110 should be designed so that the sensor function of the lidar sensor 102 is not significantly influenced by the cover 110. In particular, the cover 110 should be substantially transparent to the laser signal and the reflected signal over the entire detection range of the lidar sensor 102 (in particular over the entire azimuth and / or altitude range), i.e., substantially transparent to the wavelength of the lidar sensor (which is, for example, in the infrared range).

[0028] Figure 2 An exemplary cover 110 having a plurality of layers 201-207 is shown. Figure 2 One or more of the layers 201-207 shown may be optional. The cover 110 comprises in particular a carrier layer 201, in particular a carrier coating, which is designed to form a carrier structure for the cover 110. In addition, the carrier layer 201 may be designed such that a lidar sensor, which may weigh, for example, up to 500 g or up to 1 kg, may be fastened to the carrier layer 201 and may be carried by the carrier layer 201.

[0029] The carrier layer 201 may include a polycarbonate (PC) material, in particular, may consist of a PC material. The use of PC materials is advantageous because they may have a relatively high transparency with respect to the laser radar wavelength. Furthermore, it is possible to color the PC material (optionally in a different color, for example black), for example, in order to adapt the cover 100 to the color of the vehicle 100 .

[0030] Reference is repeatedly made in this document to the front side or rear side of the layers 201-207 of the cover 110. Here, the front side of the layers 201-207 is to be understood as the side that faces the environment of the lidar sensor 102 when the cover 110 is in use. Furthermore, the rear side of the layers 201-207 is to be understood as the (opposite) side that faces the lidar sensor 102 when the cover 110 is in use.

[0031] The carrier layer 201 may have a specific refractive index, which is referred to as the carrier refractive index in this document. In order to reduce the reflection of the laser signal sent by the lidar sensor 102, a (first) anti-reflection (AR) layer 202, in particular an AR coating, may be arranged on the rear side of the carrier layer 201. The first AR layer 202 may have an AR refractive index, which is between the air refractive index and the carrier refractive index. If necessary, the first AR layer 202 may have an AR refractive index that varies along the thickness of the first AR layer 202. The AR refractive index may increase in particular from the rear side of the first AR layer 202 in the direction of the front side. By providing an AR layer 202 on the rear side of the carrier layer 201, the degree of reflection of the laser signal on the rear side of the cover 110 may be reduced, thereby reducing the obstruction of the laser signal by the cover 110.

[0032] The second AR layer 205 can be arranged on the front side of the carrier layer 201 in a corresponding manner, and the second AR layer has an AR refractive index between the refractive index of air and the refractive index of the carrier. The AR refractive index can increase from the front side to the back side as necessary. By providing the second AR layer 205 on the front side of the carrier layer 201, the degree of reflection of the reflected signal on the front side of the cover 110 can be reduced, thereby reducing the obstruction of the reflected signal by the cover 110.

[0033] The cover 110 comprises a heating layer 203, wherein the heating layer 203 can be arranged, in particular embedded, between a further auxiliary carrier layer 204 (in particular a film) and the carrier layer 201 for protection and / or fixing. The heating layer 203 can be designed to heat the entire surface of the cover 110 (which is related to the detection range of the lidar sensor 102), in particular in order to eliminate, in particular evaporate, moisture on the front side of the cover 110. The heating layer 203 can have a grid of electrically conductive nanotubes, which can be energized for heating. In this case, a certain surface portion of the surface to be heated of the cover 110 is covered by the grid, which surface portion is preferably less than 10% or less than 5%. This can be achieved by using a relatively large mesh grid and / or relatively small nanotubes. Therefore, the damage of the heating layer 203 to the sensing characteristics of the lidar sensor 102 can be minimized.

[0034] The cover 110 may also have a protective layer 206 on the front side of the cover 110, especially directly in front of the second AR layer 205, which is configured to protect the layers 205, 204, 203, 201, 202 of the cover 110 arranged on the rear side of the protective layer 206 from mechanical and / or chemical environmental influences.

[0035] The cover 110 may also have a comfort layer 207 on the front side of the protective layer 206 , which is designed, for example, to facilitate the removal of the protective layer from the cover 110 .

[0036] Thus, by using different coatings of carrier layer 201, a cover 110 can be provided for lidar sensor 102, by which the functionality of lidar sensor 102 is only slightly restricted. Cover 110 can meet different requirements with respect to the lidar functionality, with respect to the cleaning of cover 110, with respect to the heat resistance of cover 110 and / or with respect to the durability of cover 110.

[0037] The cover 110 can have a polycarbonate carrier layer 201 and an integrated heating element 203 on a (PC) film 204, which is connected to the carrier layer 201 (for example, injected). Anti-reflection coatings 202, 205 can be arranged thereon in order to improve the performance of the lidar sensor 102 covered by the cover 110. The cover 110 (Cover) can be protected from environmental influences by a hard coating 206. In addition, an "easy-to-clean" coating 207 can be applied for cleaning requirements.

[0038] The present invention is not limited to the embodiments shown. In particular, it should be noted that the description and drawings are intended only to illustrate the principles of the proposed devices and systems.

Claims

1. A cover (110) for a laser radar sensor (102), in, The rear side of the cover (110) faces the laser radar sensor (102) when in use, and wherein the opposite front side of the cover (110) faces the environment of the laser radar sensor (102) when in use, wherein the cover (110) comprises: - a carrier layer (201), the carrier layer having a carrier refractive index; a first antireflection layer (202) arranged between the carrier layer (201) and the back side of the cover (110), the first antireflection layer being referred to as first AR layer for short, having a first AR refractive index between the refractive index of air and the refractive index of the carrier; and A second AR layer (205) arranged between the carrier layer (201) and the front side of the cover (110), the second AR layer having a second AR refractive index between the refractive index of air and the refractive index of the carrier.

2. The cover (110) according to claim 1, in, - the first AR refractive index of the first AR layer (202) increases smoothly or stepwise from the rear side of the cover (110) toward the carrier layer (201) along the transmission direction; and / or The second AR refractive index of the second AR layer (205) increases smoothly or stepwise from the front side of the cover (110) toward the carrier layer (201) along the receiving direction.

3. The cover (110) according to any one of the preceding claims, in, The carrier layer (201) comprises polycarbonate (PC) material, and in particular the carrier layer consists of polycarbonate material.

4. The cover (110) according to any one of the preceding claims, in, The cover (110) comprises a heating layer (203) which is configured to heat the cover (110), in particular a surface of the front side of the cover (110), so as to evaporate liquid on the surface of the cover (110).

5. The cover (110) according to claim 4, in, The heating layer (203) comprises a grid composed of electrically conductive nanotubes.

6. The cover (110) according to claim 5, in, - the edges of the grid of nanotubes surround the heatable surface of the cover (110); and The grid of nanotubes is macro-meshed and / or the nanotubes are small, so that the nanotubes of the grid of nanotubes cover overall only 5% or less of the heatable surface.

7. The cover (110) according to any one of claims 4 to 6, in, The heating layer (203) is arranged between the second AR layer (205) and the carrier layer (201).

8. The cover (110) according to any one of claims 4 to 7, in, The heating layer (201) is arranged, in particular embedded, between a carrier film (204) and the carrier layer (201).

9. The cover (110) according to any one of the preceding claims, in, The cover (110) comprises a protective layer (206) which is arranged between the front side of the cover (110) and the second AR layer (205) and is designed to protect the cover (110) from mechanical and / or chemical environmental influences.

10. The cover (110) according to any one of the preceding claims, in, The cover (110) includes a comfort layer (207) on the surface of the front side of the cover (110), and the comfort layer is configured to facilitate cleaning of the cover (110).

11. The cover (110) according to any one of the preceding claims, in, The cover (110), in particular the carrier layer (201), is designed so that the lidar sensor (102) can be fixed to the rear side of the cover (110) and supported by the cover (110).

12. A motor vehicle (100) comprising a cover (110) according to any one of the preceding claims and a lidar sensor (102) arranged at the rear side of the cover (110).

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