LIDAR SYSTEM AND METHOD FOR PRODUCING A COATING

Abstract

The application concerns a lidar system (10) for a vehicle (20). The lidar system (10) is configured to monitor a surveillance area (22) by means of an optical signal (L). The lidar system (10) has: A housing (24) with a cover (26) which has a coating (28) wherein the coating is arranged in the optical path of the optical signal (L) and wherein the coating has an optical layer (30) which blocks light in the visible range. The application further relates to a vehicle (20) which has the lidar system (10), a use of the lidar system (10) in a vehicle (20) and a method for producing a coating (28).

Description

Technical field

[0001] The application relates to a lidar system for a vehicle, a vehicle itself, and the use of the lidar system in a vehicle. The application further relates to a method for producing a coating for a cover of a lidar system. background

[0002] Modern vehicles, such as cars, vans, trucks, motorcycles, etc., are equipped with a variety of sensor systems whose data serves to inform the driver and / or is provided to driver assistance systems. These sensor systems detect the vehicle's surroundings as well as other road users. Based on the collected data, a model of the vehicle's environment can be created, and the system can react to changes in this environment.

[0003] Sensor systems are constantly being developed for various functions, such as capturing environmental information at close and long range of vehicles, including passenger cars and commercial vehicles. These systems can also be used for driver assistance systems, particularly those for autonomous or semi-autonomous vehicle control. Specifically, they can be used to detect obstacles and / or other road users in the front, rear, or blind spot areas of a vehicle. These systems can be based on various sensor principles, such as radar, ultrasound, and optics.

[0004] In optical detection systems, an important optical sensor principle for environmental sensing, e.g., of vehicles, is lidar technology (Lidar stands for Light Detection and Ranging). A lidar system comprises an optical transmitter and an optical receiver. The transmitter can emit an optical signal in the form of light, which can be continuous or pulsed. The optical signal can also be modulated. In a lidar system, light in the form of laser beams in the ultraviolet or infrared range can be used. The receiver detects the light after reflection within a monitoring area of ​​the lidar system. The received optical signal can be analyzed using the transmitted optical signal, for example, using a time-of-flight method, and the spatial location and distance of the object from which the reflection occurred can be determined.The evaluation can be performed in a processing unit of the lidar system. In this context, reflection or reflected light is understood to mean any light that is thrown back and is specifically intended to include light thrown back by scattering or absorption-emission.

[0005] In WO2022 / 175634A1, a laminated glazing for a vehicle is described, comprising a first extra-clear glass pane (outer glazing), a lamination interlayer, and a second glass pane (inner glazing) with a recess in this second pane. It is intended to position a near-infrared lidar system behind the recess in the laminated glazing. The laminated glazing contains a mineral element that is coated with an anti-reflective material to improve the efficiency of the lidar system.

[0006] US11609336B1 describes a lidar system that can be applied to an anti-reflective coated windshield. Overview

[0007] A lidar system for a vehicle is set up to monitor a surveillance area using an optical signal. The lidar system has a housing with a cover.

[0008] To monitor the monitored area, the lidar system has an optical transmitter and an optical receiver. The transmitter emits the optical signal, which is then reflected within the monitored area. The receiver picks up the reflected optical signal. The optical transmitter and receiver of the lidar system are housed within the enclosure. The enclosure provides mechanical and electrical protection and shielding from the environment. The enclosure can be solid, flexible, or partially solid and partially flexible. It can be made of plastic, fiber material, metal, and / or composite material. The enclosure has an opening, which is covered by a cover. This opening faces the monitored area. The cover is designed to be transparent to the optical signals from the lidar system.The opening and cover are designed to allow the optical signal used by the lidar system to monitor the surveillance area to pass through on its way to and from the surveillance area. The wavelength range of the optical signal is, for example, in the non-visible range of light.

[0009] The cover has a coating positioned in the optical path of the optical signal, and this coating comprises an optical layer that blocks light in the visible range. "Visible" in this context refers to light visible to the human eye. This blocking of light in the visible range can be achieved, for example, for specific wavelength ranges or for the entire visible range. In particular, wavelength ranges of light that do not overlap with the wavelength range of the optical signal L are blocked.

[0010] The coating is designed and arranged so that it is passed through by the optical signal during monitoring of the monitored area. Optionally, the coating can also be larger and extend over areas that lie outside the optical path of the signal.

[0011] The blocking of visible light can occur, for example, in one direction, in several directions, or in all directions. Visible light can be transmitted from other viewing directions. Optionally, the blocking effect for visible light can be applied from all directions of incidence. The optical layer is specifically designed to allow the optical signals from the lidar system to pass through for monitoring the monitored area.

[0012] The optical layer of the cover can, for example, have a transmission range for optical signals that is limited to the spectrum of optical signals used by the lidar system to monitor the surveillance area. The cover can also, for example, block only certain ranges of visible light while allowing others to pass through.

[0013] The optical layer can thus be designed so that the lidar system is not visible from the other side of the cover and / or is only visible in certain frequency ranges of the visible spectrum. This allows the cover's appearance to be better adapted to its surroundings. In particular, the lidar system can be positioned behind the cover in such a way that it is not visible from the outside (through the cover). Specifically, the lidar system can be positioned inside the vehicle behind the cover in such a way that it is not visible from the outside (outside the vehicle). This allows the lidar system to be integrated into the vehicle design in a way that is less visually disruptive.

[0014] In one embodiment of the lidar system, the optical layer has anti-reflective properties. This further improves the quality of the environmental detection by the lidar system, as interfering reflections can be avoided.

[0015] In one embodiment of the lidar system, the coating includes a colored layer with a visible color. This allows the cover's appearance to be even better adapted to its surroundings, as the color can be matched to the environment. For a lidar system installed in a vehicle, the visible color of the colored layer can be chosen, for example, to closely match the vehicle's design and, for instance, to the vehicle's paint color. The coating can include the colored layer in addition to the optical layer. The colored layer is specifically designed to allow the optical signals from the lidar system to pass through for monitoring the surveillance area.

[0016] In one embodiment of the lidar system, the color layer in the cover coating is positioned further out than the optical layer. This allows the aesthetic effect of the color layer to be clearly visible. "Outer" here refers to the view from the inside of the housing. Therefore, from the inside of the housing, the coating in this embodiment first has the optical layer and then the color layer. The optical signals on their way to the monitoring area thus pass through the optical layer and the color layer in that order. The optical signals reflected in the monitoring area, on their way back to the lidar system, also pass through the color layer and the optical layer in that order.

[0017] In one embodiment of the lidar system, the coating has an adhesive layer made of an adhesive material, which is particularly elastic. The adhesive layer is designed to transmit the optical signals of the lidar system while simultaneously exhibiting adhesive properties. This gives the lidar system flexibility in its use and also in its mounting in the environment, e.g., in a vehicle. The coating can optionally have multiple adhesive layers.

[0018] For example, the adhesive layer allows for attachment, e.g., to the inside of the vehicle's windshield, without the need for additional fasteners. Depending on the cover's design, the adhesive layer can be applied to the colored layer on the outside (on the side facing away from the housing) and / or to the optical layer on the inside (on the side facing the housing).

[0019] For example, the adhesive layer can be designed so that the lidar system housing can be attached to the cover using the adhesive layer. The part of the lidar system housing surrounding the opening can then be glued to the cover, for example, using the adhesive layer.

[0020] The adhesive layer can consist of, for example, silicone gel, silicone rubber, and / or an optically clear adhesive such as OCA (optical clear adhesive). Silicone gel and silicone rubber can be tailored to their desired optical properties, such as optical refraction. Optically clear adhesives like OCA offer the advantage of very high light transmission and the ability to reduce reflections and air bubbles between layers. Therefore, optically clear adhesives like OCA are particularly suitable for layered applications.

[0021] In one embodiment of the lidar system, the coating has a base layer located between the adhesive layer and the optical layer, or between the adhesive layer and the color layer. The base layer acts as a substrate for the coating and can, for example, consist of quartz. Quartz has excellent optical properties and is resistant to environmental influences such as radiation and / or temperature fluctuations.

[0022] The coating layers are optically transparent, in particular, to signals whose frequencies are within the frequency range of the optical signal used by the lidar system to monitor the surveillance area. The optical layer, the adhesive layer, the base layer, and the color layer are specifically transparent to this optical signal used by the lidar system. This transparency is particularly evident for those directions of incidence used by the lidar system to monitor the surveillance area.

[0023] The lidar system can, for example, be installed and / or used in a vehicle. The cover can be designed as part of the vehicle's glass, particularly the windshield. Thus, a portion of the vehicle's glass, especially the windshield, can serve as the cover for the lidar system. This reduces attenuation of the optical signal used by the lidar system, thereby improving the monitoring quality and object detection within the monitored area.

[0024] The vehicle may be equipped with the described lidar system. The lidar system cover may include part of the windshield. This is particularly advantageous for a lidar system located inside the vehicle behind the windshield.

[0025] One advantage of this lidar system arrangement is that the lidar system's front lens is integrated with the windshield, allowing the lidar system's cover to be cleaned along with the windshield. This eliminates the need for a separate cleaning process for the lidar's front lens. Compared to a lidar system mounted externally on the vehicle's body, such as on the roof, this internal placement behind the windshield offers the advantage of reduced wind resistance.

[0026] In one embodiment of the vehicle, the optical layer is designed and arranged such that the lidar system is not visible from outside the vehicle. In particular, the lidar system's aperture can be applied directly to the vehicle's windshield, so that the windshield acts as a protective shield for the lidar system. This has the advantage of improving the transparency of the optical signal used by the lidar system to monitor the surveillance area and reducing absorption. At the same time, the optical layer of the coating keeps the lidar system and its components invisible from outside the vehicle. It is also possible to incorporate a colored layer into the coating, allowing the area covered by the lidar in the windshield, or an area beyond it, to be color-matched to the vehicle's design.This allows for low absorption through the cover as part of the windshield, thus avoiding associated interreflections.

[0027] In a process for producing a coating for a lidar system cover, a color layer is applied to a base layer using dye sublimation transfer printing. Specifically, the process is used to produce a coating for a lidar system cover.

[0028] Dye-sublimation thermal transfer printing, also known as dye-sublimation thermal transfer printing or dye-sublimation, is a printing process that uses heat to transfer dye, for example in the form of ink, from a substrate to a printing medium. In this process, the dye is converted from a solid to a gaseous state (sublimation) in a single step, without first becoming liquid. This method allows for the production of high-quality, durable prints that are resistant to peeling and fading. The dye can penetrate the material, enabling richer colors. List of characters

[0029] In the following, embodiments of this application are further explained and described with reference to the figures. They show Fig. 1 a schematic representation of a vehicle with a lidar system, Fig. 2 a schematic representation of a vehicle windshield with coating, Fig. 3 a schematic representation of an embodiment of the lidar system, Fig. 4 a schematic representation of another embodiment of the lidar system, Fig. 5 a schematic representation of an embodiment of the coating, and Fig. 6 a schematic representation of another embodiment of the coating.

[0030] The same reference symbols are used in the figures for identical or similar elements. Representations in the figures may not be to scale. Character description

[0031] Fig. Figure 1 schematically shows a vehicle 20, for example a passenger car. The vehicle 20 has a lidar system 10. The lidar system 10 is located in a front area of ​​the vehicle 20, and the monitoring area 22 it covers is located in front of the vehicle 20 in the direction of travel. The lidar system can, in particular, be mounted inside the vehicle 20 in an upper area of ​​the windshield 26.

[0032] The lidar system 10 comprises an optical transmitter 12, an optical receiver 14, an optical deflector 16, and a computing unit 18. The computing unit 18 can include a processor, an FPGA, or similar for processing data, as well as memory and data input and output interfaces.

[0033] The optical transmitter 12 emits an optical signal L. It has a light source for emitting, for example, laser light in the invisible-to-human spectrum. The optical signal L is transmitted into the monitoring area 22. The optical receiver 14 receives the optical signal L reflected at a reflection point in the monitoring area 22. The reflection can occur, for example, at an object O located in the monitoring area 22.

[0034] The optical deflection device 16 is configured to deflect the optical signal L transmitted by the optical transmitter 12 into the monitoring area 22 and to deflect the optical signal L reflected from the monitoring area 22 to the optical receiver 14. The deflection device 16 can be controlled by the processing unit 18 such that it can successively assume several different positions and the optical signal L accordingly performs a scanning movement over the monitoring area 22.

[0035] The deflection device 16 can, for example, include a rotating mirror device that performs a rotational movement to deflect the optical signal L such that the scanning movement is carried out by the optical signal L. During the rotational movement, the angular position of the deflection device 16 is changed. The optical signal L can be emitted in pulsed light pulses.

[0036] The scanning motion 26 allows information to be obtained about reflection points that have different solid angles relative to the lidar system 10. Alternatively or additionally to the rotating mirror device, the deflection device for deflecting the optical signal can include MEMS mirrors. Other deflection options include phased optical arrays or, for example, liquid crystal-based systems.

[0037] The optical receiving device 14 comprises an optoelectronic receiving sensor, also called a detector. The receiving sensor can, for example, have point-shaped sensors, so-called pixels or receiving pixels, which can be arranged in rows or areas. A pixel can, for example, have one or more avalanche photodiodes (APDs) or one or more single-photon avalanche diodes (SPADs). The optoelectronic detector can receive light, in particular the optical signal L, and convert it into electrical receiving signals. The electrical receiving signals can be processed by the processing unit 18.

[0038] The processing unit 18 is configured to control the transmission of the optical signal L depending on the deflection device 16, e.g., depending on the angular position of the deflection device 16. The processing unit 18 is further configured to evaluate the transmitted and received optical signal L. From the evaluation of the optical signal L, which was reflected in the monitoring area 22, environmental information about the surroundings of the vehicle 20 in the monitoring area 22 can be obtained.

[0039] A point cloud can be generated from the environmental information produced by the lidar system 10 during the evaluation process. Information about each point in the point cloud is provided, depending on the environmental information. In particular, the points in the point cloud contain information about the spatial location and distance of the reflection points in the monitoring area 22. The reflection points are those points in the monitoring area 22 where the reflection of the optical signal L emitted and received by the lidar system 10 occurred.

[0040] The point cloud can be used, for example, to detect objects O in the monitoring area 22, to determine the distance to such objects O, and / or to perform further analyses. The point cloud can be generated, for example, in the lidar system 10 from environmental information, and / or the point cloud can be generated, for example, in another control unit of the vehicle 20 from the environmental information of the lidar system 10.

[0041] The additional control unit can, for example, be configured as the central vehicle computer of vehicle 20, in which data from multiple sensor systems, such as additional lidar systems, radar sensors, ultrasonic sensors, cameras, and similar devices, of vehicle 20 can be received, evaluated, and / or further processed. This additional control unit can, for example, be used to implement autonomous or semi-autonomous driving functions.

[0042] The lidar system 10 can be used to detect stationary or moving objects O in the environment 22. Such objects O can include things such as vehicles, people, animals, plants, obstacles, road surface irregularities, especially potholes or stones, road boundaries, traffic signs, open areas, especially parking lots, precipitation, or the like.

[0043] The optical transmitter 12, the optical receiver 14, the optical deflector 16, and the processing unit 18 are arranged in a housing 24. The housing 24 provides mechanical and electrical protection for the components of the lidar system 10 and shielding from the environment. The housing 24 can be solid or flexible, or partially solid and partially flexible. It can be made of plastic, fiber material, metal, and / or composite material.

[0044] The housing 24 is designed to protect the components of the lidar sensor from environmental influences such as dust, moisture, and wind. The housing can also be designed to allow the lidar system 10 to be mounted as a single unit. For example, the lidar system 10 can be mounted as a unit inside its housing 24 on the windshield 26 of the vehicle 20. This makes it possible to design and manufacture the lidar system 10 with specific hardware and software interfaces and then to enable communication with other control units of the vehicle 20 via these interfaces. The interfaces of the lidar system 10 can be configured to provide the environmental data and / or the point cloud.

[0045] In Fig. Figure 2 schematically shows the windshield 26 of the vehicle 20 with a coating 28.

[0046] The housing 24 of the lidar system 10 has an opening 38 without a front window. The housing 24 of the lidar system 10 is in Fig. 2 with the coated windshield 26 of the vehicle 20 as a cover 26. The attachment of the cover 26 is achieved by attaching it to the coated windshield 26, whereby the part of the windshield 26 that covers the opening 38 then acts as a cover 26.

[0047] The coating 28 blocks visible light, thus rendering the lidar system 10 and / or its components invisible. At the same time, the coated windshield 26 achieves high transparency, as a separate windshield for the lidar system 10, in addition to the cover 26, is not required. The coating 28 also exhibits high transparency to electromagnetic waves in the wavelength range of the optical signal L.

[0048] Placing the lidar sensor 10 behind the vehicle's windshield 26 offers several advantages, particularly in the context of advancing vehicle automation and the development of autonomous driving. For example, good protection from environmental influences can be achieved by placing the lidar system 10 behind the windshield 26. The windshield 26 also provides a natural barrier against dirt and dust that could otherwise impair performance. Windshield wipers and washers can keep the lidar system 10's view unobstructed. Integration behind the windshield 26 keeps the vehicle 20 slim and aerodynamically efficient. In particular, when centrally positioned behind the windshield 26, the lidar system 10 can achieve wide and uniform coverage of the monitoring area 22.

[0049] In Fig. Figure 3 schematically illustrates an embodiment of the lidar system 10 in which the opening 38 of the housing 24 is covered by the windshield 26 as a cover 26. The coating 28 extends in the area of ​​the opening 38. In this embodiment, the housing 24 can be attached to the windshield 26, for example, by means of an adhesive layer 34 of the coating 28. For example, the adhesive layer 34 of the coating 28 can be located on the side of the windshield 26 of the coating 28 and extend so far that areas of the housing 24 adjacent to the opening 38 are covered by the adhesive layer 34, and the housing 24 of the lidar system 10 can thus be attached to the windshield 26. The area of ​​the windshield 26 that covers the opening 38 then serves as the cover 26.

[0050] In Fig. Figure 4 schematically illustrates another embodiment of the lidar system 10, in which the opening 38 of the housing 24 is covered by the windshield 26 as a cover 26. The coating 28 extends beyond the area of ​​the opening 38 on the windshield 26. In this embodiment, the housing 24 can also be attached to the windshield 26, for example, via the adhesive layer 34 of the coating 28. In this embodiment, the adhesive layer 34 of the coating 28 can be located on the side of the coating 28 facing away from the windshield 26. The areas of the housing 24 adjacent to the opening 38 can thus be covered by the adhesive layer 34, and the housing 24 of the lidar system 10 can be attached to the windshield 26 by means of the adhesive effect. The area of ​​the windshield 26 that covers the opening 38 then serves as a cover 26.

[0051] In Fig. Figure 5 schematically shows the structure of one embodiment of the coating 28. The coating 28 is applied to the windshield 26. The coating 28 comprises an optical layer 30, a base layer 32, and an adhesive layer 34.

[0052] The coating 28 is attached to the windscreen 26 via the adhesive layer 34. The adhesive layer 34 can extend beyond the optical layer and the base layer 32 and thus optionally – as in Fig. Figure 3 shows that the adhesive layer 34 can also be used for attaching and securing the housing 24. The adhesive layer 34 is highly transparent to the wavelength range of the optical signal L. Such an adhesive layer 34 can have an optically transparent double-sided adhesive.

[0053] The adhesive layer 34 can, for example, contain OCA (Optical Clear Adhesive). OCA is an optically transparent, double-sided adhesive without a substrate, which is also used in display technology to bond different layers of screen components, such as glass and plastic covers. OCA offers high light transmission and reduces reflections and air bubbles between the bonded layers. OCA thus also has an anti-reflective effect.

[0054] The base layer 32 acts as a substrate for the coating 28 and can, for example, consist of quartz. Quartz has very good optical properties and is resistant to environmental influences such as radiation and / or temperature fluctuations. The base layer 32 is highly transparent to the wavelength range of the optical signal L.

[0055] The optical layer 30 is highly transparent to the wavelength range of the optical signal L. At the same time, the optical layer 30 blocks light in the visible range. For example, the optical layer 30 can be configured to block light across the entire visible range. Optionally, the optical layer can be configured to block visible light in some wavelength ranges and transmit it in others. The optical layer 30 can, for example, be configured to transmit or block light in the visible range from certain solid angles or ranges of solid angles. Optionally, the optical layer 30 can be configured to block light in the visible range from the solid angles corresponding to the monitoring area. Optionally, the optical layer 30 can be configured to block visible light from all solid angles.

[0056] Additionally, the optical layer 30 can exhibit anti-reflective properties. This can reduce absorption and / or interreflection between the layers or between the layers and the disk.

[0057] Due to the blocking effect of the optical layer 30 with respect to visible light, the lidar system 10 can be designed to be imperceptible from outside the vehicle 20. It can be designed in such a way that the design of the vehicle 20 takes center stage and the visibility of the lidar system 10 is aligned with the design of the vehicle 20.

[0058] In Fig. Figure 6 schematically illustrates the structure of another embodiment of the coating 28. The coating 28 is applied to the windshield 26. The coating 28 has the layers as in the embodiment of Fig.5 and additionally a color layer 36. The color layer 36 is highly transparent for the wavelength range of the optical signal L.

[0059] In the illustrated embodiment, the color layer 36 is arranged between the optical layer 30 and the base layer. The color layer 36 can be applied to the base layer, for example, by thermal transfer printing with dye sublimation. The optical layer 30 can then be applied to the color layer 36.

[0060] Preferably, the color of the paint layer can be chosen to match the design of the vehicle 20. The optical layer 30 can then ensure that the lidar system 10 recedes into the background compared to the design of the vehicle 20, and the paint layer 36 can ensure that the design of the vehicle 20 is visually enhanced. Reference sign 10 Lidar systems 12 optical transmitting device 14 optical receiving device 16 optical deflection devices 18 computing units 20 vehicles 22 Monitoring area 24 cases 26 Cover / Windshield 28 Coating 30 optical layer 32 Base layer 34 adhesive layer 36 layers of paint 38 Opening L optical signal O object QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] WO 2022 / 175634A1

[0005] US 11609336B1

[0006]

Claims

[1] Lidar system (10) for a vehicle (20), wherein the lidar system (10) is configured to monitor a monitoring area (22) by means of an optical signal (L), wherein the lidar system (10) comprises: a housing (24) with a cover (26) which has a coating (28) wherein the coating is arranged in the optical path of the optical signal (L) and wherein the coating has an optical layer (30) which blocks light in the visible range. [2] Lidar system (10) according to claim 1, wherein the optical layer (30) has anti-reflective properties. [3] Lidar system (10) according to claim 1 or 2, wherein the coating has a color layer (36) which has a color in the visible range. [4] Lidar system (10) according to claim 3, wherein the color layer (36) in the coating (28) of the cover (26) is arranged further outwards than the optical layer (30). [5] Lidar system (10) according to one of the preceding claims, wherein the coating (28) has an adhesive layer (34) which has adhesive material, wherein the adhesive material is in particular elastic. [6] Lidar system (10) according to claim 5, wherein the housing (24) of the lidar system can be attached to the cover using the adhesive layer (34). [7] Lidar system (10) according to claim 5 or 6, wherein the adhesive layer (34) comprises silicone gel and / or silicone rubber. [8] Lidar system (10) according to one of the preceding claims, wherein the coating (28) has a base layer which is arranged between the adhesive layer (34) and the optical layer (30) or between the adhesive layer (34) and the color layer (36). [9] Lidar system (10) according to one of the preceding claims, wherein the layers (30, 32, 34, 36) of the coating (28) are optically transparent to signals whose frequencies are in the range of the frequency of the optical signal (L). [10] Lidar system (10) according to one of the preceding claims, wherein the lidar system (10) is arranged in a vehicle (20) and the cover (26) comprises a part of the windshield (26) of the vehicle (20). [11] Vehicle (20) comprising a lidar system (10) according to any of the preceding claims. [12] Vehicle (20) according to claim 11, wherein the optical layer (30) is designed and arranged such that the lidar system (10) is not visible from outside the vehicle. [13] Use of the lidar system (10) according to any one of claims 1 to 10 in a vehicle (20). [14] Method for producing a coating (28) for a cover (16) of a lidar system (10) wherein a color layer (36) is applied to a base layer (32) using dye sublimation transfer printing. [15] Method for producing a coating (28) according to claim 14, wherein the coating (28) is produced for the cover (26) of a lidar system (10) according to any one of claims 1 to 10.

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