Lidar sensor with specific orientation of an optical module, and method

Abstract

One aspect of the invention relates to a LIDAR sensor (1) for a vehicle, comprising a housing (2) having an accommodating space (5) in which at least one optical module (11, 12) is located, wherein the optical module (11, 12) has a lens unit (15) having at least one cylindrical lens unit (23), and the optical module (11, 12) has a rotatable adjustment unit (16) by means of which at least the cylindrical lens unit (23) can be set relative to an image sensor (14) of the optical module (11, 12) in at least one rotational position and therefore adjusted to conform to the image sensor (14). One aspect also concerns a method.

Description

[0001] LiDAR sensor with specific orientation of an optical module, as well as methods

[0002] One aspect of the invention relates to a LiDAR sensor. The LiDAR sensor has a housing, which can also be referred to as an outer housing. A receiving chamber is formed within the housing, in which at least one optical module is arranged. The invention also relates to a method.

[0003] With a LiDAR sensor or laser scanner, it is essential that the components are fixed in position. This is particularly important for transmitting and receiving signals to ensure reliable and accurate operation.

[0004] The object of the present invention is to create a LIDAR sensor in which the adjustment of an optical module is improved.

[0005] This task is solved by a LIDAR sensor and a method according to the independent claims.

[0006] One aspect of the invention relates to a LiDAR sensor. The LiDAR sensor can also be described as a laser-based detection unit. The LiDAR sensor is particularly sensitive in the infrared range. The LiDAR sensor has a housing. This can also be referred to as an outer housing. A receiving chamber is formed within the housing, in which at least one optical module is arranged.

[0007] The LIDAR sensor comprises, as an optical module, in particular a laser unit or laser module and / or a receiver unit or receiver module. The laser unit emits electromagnetic beams preferably in a wavelength range between 800 nm and 1600 nm, in particular between 850 nm, 905 nm, or 1550 nm.

[0008] The optical module comprises a lens unit or lens module. This lens unit includes at least one cylindrical lens unit. Furthermore, the optical module has a rotatable adjustment unit with which at least the cylindrical lens unit can be adjusted relative to an image sensor of the optical module in at least one rotational position and aligned with the image sensor. This allows a specific sub-section of the lens unit, namely the cylindrical lens unit, to be aligned with high precision to the image sensor in a compact and highly functional design within the optical module itself, particularly in at least one rotational direction.

[0009] The use of a cylindrical lens unit in the optical module enables precise focusing of light beams in a very compact design. Especially when the optical module is a receiver module of the LiDAR sensor, it is essential to receive the incident light beams—particularly the laser beams reflected from an object by a laser module of the LiDAR sensor—as the best possible image and direct them with high focus onto the image sensor. The light must be focused with exceptional precision. It is of paramount importance to be able to concentrate the highest possible energy of the laser light into focus. Cylindrical lenses enable this with particular efficiency while also offering a very compact design. However, to fulfill these requirements, this cylindrical lens unit must be aligned with the image sensor with the utmost precision. This is made possible by the invention.

[0010] In one embodiment, the cylindrical lens unit has the configuration of a single-piece lens. This lens unit, in particular, comprises several cylindrical lenses. Such a cylindrical lens unit enables the desired imaging characteristic mentioned above, which achieves highly precise focusing of the incident laser light to the image sensor. The ability to concentrate the highest energy of the laser beam at the focus point is thus fulfilled with particular efficiency.

[0011] In one embodiment, the cylindrical lens unit is formed in a plate-like shape. It can, for example, be made of glass, particularly real glass. On one side of the cylindrical lens unit, this plate-like element can be flat. Additionally or instead, this cylindrical lens unit can have a wave contour on the other side. This is particularly evident in a cross-section that runs perpendicular to a longitudinal axis of the cylindrical lens unit and whose cross-sectional plane thus contains both the edge contour of one side and the wave contour of the other side. The wave contour defines the shape of the convexly curved cylindrical surfaces of the respective cylindrical lenses. In one embodiment, the cylindrical lens unit is arranged at one end of a housing of the lens unit.The lens unit, which can also be called a lens module or lens barrel, features the cylindrical lens unit, particularly at one end of a housing oriented towards the image sensor. This cylindrical lens unit is thus arranged on the end of the housing facing the image sensor and is therefore also positioned facing the image sensor within the lens unit. Specifically, the cylindrical unit is arranged so that it is exposed at the rear, towards the image sensor, particularly within a recess in the housing. This allows the aforementioned advantages to be achieved to a significant degree, while still ensuring that this specific cylindrical lens unit is mechanically stable on the housing. This particular positional design also enables highly precise alignment with the adjustment unit, especially within a roll angle, preferably measured around an optical axis of the optical module, relative to the image sensor.

[0012] Thus, the rotational position allows for adjustment of the cylindrical lens unit's roll angle relative to the image sensor. In one embodiment, the lens unit and the adjustment unit are additionally adjustable in three spatial directions relative to the image sensor. Therefore, in addition to rotational adjustment, adjustment in several linear directions is also possible. Preferably, this allows for adjustment of the lens unit and the adjustment unit around four axes. This enables a very versatile adjustment of the cylindrical lens unit.

[0013] In one embodiment, the lens unit comprises at least one bandpass filter. This bandpass filter filters only specific regions of the incident wavelength spectrum. This prevents unwanted wavelengths from entering the lens unit. The bandpass filter is located in a front region of the lens unit, in particular opposite the cylindrical lens unit, as viewed along the optical axis of the lens unit.

[0014] In one embodiment, the adjustment unit has an adjustment ring. This ring has an outer contour, which in particular features a gear-like structure. Such a knurled outer surface allows for particularly easy and secure manual gripping of the adjustment ring and corresponding actuation. This prevents unwanted slippage during manual adjustment. In another embodiment, the adjustment unit has an adjustment ring with an outer contour. This outer contour has several, in particular a maximum of five, and in particular three, radial engagement recesses. In particular, these engagement recesses are designed to allow an adjustment arm to engage for the automatic adjustment of the lens unit. This ensures stable coupling of the adjustment arm with the adjustment device and enables a highly precise automatic adjustment process.The engagement recesses create relatively large radial receptacles for the adjustment arm, preventing unwanted loosening or slippage in the azimuthal direction. This also allows for better absorption of forces generated in the azimuthal direction, enabling a very continuous application of torque to the adjustment ring. Even very small positional changes of the adjustment ring, which then correspond to a change in the position of the cylindrical lens unit, can be adjusted. The five, and in particular three, engagement recesses are arranged relatively symmetrically around the axis of rotation, ensuring extremely uniform and evenly distributed mechanical coupling and application of force to the adjustment ring.In particular, these multiple, especially a maximum of five, especially three, such engagement recesses are formed equidistant to each other in the direction of rotation around the axis of rotation.

[0015] In one embodiment, the adjusted position of the cylindrical lens unit is held by fixing it with adhesive.

[0016] The optical module is preferably a receiver module of the LiDAR sensor. The LiDAR sensor can also include a further optical module in the form of a laser module. In addition, a rotating mirror can be provided, which emits the laser light generated by the laser module into the surroundings and which directs the previously emitted laser beam, reflected in the surroundings, to the receiver module.

[0017] Another aspect of the invention relates to a method for mounting a LiDAR sensor. In particular, this LiDAR sensor is configured according to the aspect mentioned above or an advantageous embodiment thereof. Preferably, the method for mounting the LiDAR sensor comprises the following steps:

[0018] Mounting an optical module of the LIDAR sensor into a housing, in particular a first housing part, in particular into a mounting position on a bearing device, in particular such that a bearing pin of the first housing part engages in a pin receptacle of the optical module;

[0019] Adjusting a cylindrical lens unit of a lens unit of the optical module relative to an image sensor of the LIDAR sensor, in which an adjustment unit is rotated and thereby an adjusting rotational position of the cylindrical lens unit is set; in particular fixing the adjusted position of the cylindrical lens unit to the image sensor by applying an adhesive and creating a fixing adhesive connection between the lens unit and a housing that accommodates the image sensor.

[0020] Advantageous embodiments of the LIDAR sensor, such as the positions of elements and / or of elements relative to each other, are also to be considered advantageous embodiments of the method, and vice versa. The assembly process steps are carried out in such a way that these positions are achieved.

[0021] Exemplary embodiments of the invention are explained in more detail below with reference to schematic drawings. These show:

[0022] Fig. 1 . an exploded view of an embodiment of a LIDAR sensor according to the invention;

[0023] Fig. 2 shows a perspective view of an embodiment of a lens unit of an optical module of the LIDAR sensor;

[0024] Fig. 3 shows the lens module according to Fig. 2 in a perspective view different from Fig. 2;

[0025] Fig. 4 shows a perspective view of the optical module with the lens unit and various axes around which a cylindrical lens unit of the lens unit can be adjusted relative to an image sensor of the optical module; and

[0026] Fig. 5 shows the adjusted state of the lens unit, in particular the cylindrical lens unit, relative to the image sensor and a schematic representation of a means of fixing this adjusted position. In the figures, identical or functionally equivalent elements are designated with the same reference numerals.

[0027] Figure 1 shows an exploded view of an embodiment of an optical detection unit that operates, in particular, in the infrared using a laser. This unit is a vehicle detection unit, specifically a LiDAR sensor 1. The LiDAR sensor 1 has a housing 2. The housing 2 comprises a first housing part 3 and a separate second housing part 4. When the housing 2 is closed, with the two housing parts 3 and 4 abutting and connected, a receiving chamber 5 is formed, or rather, bounded by the walls of the housing parts 3 and 4. At least one circuit board 6 of the LiDAR sensor 1 is arranged in this receiving chamber 5.

[0028] Housing parts 3 and / or 4 can, for example, be made of die-cast aluminum.

[0029] For example, the first housing part 3 contains another circuit board 7, an external electrical connector 8, and another connector 9. A rotating mirror 10 is also arranged in the first housing part 3. Furthermore, a first optical module is arranged in the first housing part 3. This first optical module is a receiver module 11. In addition, another optical module is arranged in the first housing part 3. This second optical module is a laser module 12. The receiver module 11 has a housing 13. An image sensor 14 is arranged in this housing 13. A lens unit 15 is also arranged in this housing 13. The lens unit 15 can be adjusted relative to the image sensor 14 by means of an adjustment unit 16, which is rotatably arranged.

[0030] In particular, the lens unit 15 can be rotated about a rotational axis A. Thus, the roll angle of the lens unit 15 relative to the image sensor 14 can be adjusted. This rotational axis A is also, in particular, the principal optical axis of the lens system of the lens unit 15.

[0031] Figure 2 shows a perspective view of an embodiment of the lens unit 15. This unit has a housing 17 in which several lenses are preferably arranged. In one embodiment, a bandpass filter 18 is arranged at the front, viewed along the longitudinal axis A. The adjustment unit 16 has an adjustment ring 19. This ring has an outer contour 20, which preferably has a gear-like structure 22. This outer contour 20 can also be described as knurled. In particular, this gear-like structure 22 is designed to be gripped manually by a person using their fingers, in order to manually rotate the adjustment ring 19 about the axis A and thus manually adjust and set the lens unit 15.

[0032] In one embodiment, several, in particular a maximum of five, here three, engagement recesses 21 are formed on this outer contour 20. These have a radial depth that is greater than that of the gear-like structure 22. These engagement recesses 21 are arranged in the direction of rotation around the longitudinal axis A and are thus azimuthally equidistant from one another. They are designed to engage an adjustment arm of an automatic adjustment system, with which the adjustment of the lens unit 15 is carried out automatically.

[0033] In Fig. 3, the lens unit 15 is shown from a perspective different from Fig. 2. As can be seen here, the lens unit 15 has a cylindrical lens unit 23. The cylindrical lens unit 23 is arranged at a rear end 17a of the housing 17. In particular, this cylindrical lens unit 23 is arranged so that it is exposed at the rear and is arranged in a receptacle 24 of the housing 17, in particular, at least partially embedded or recessed therein. In the exemplary embodiment, the cylindrical lens unit 23 has several, in particular rod-like, cylindrical lenses 25, 26, 27, 28, and 29. These are arranged parallel to each other and directly adjacent to each other. As can be seen in the schematic representation in Fig. 3 to the right of the perspective view of the lens unit 15, the cylindrical lens unit 23 is formed in one piece in this cross-section.On a side 23a facing away from the image sensor 14, the cylindrical lens unit 23 is preferably planar. The five cylindrical lenses 25 to 29 shown here as an example are formed on the opposite side 23b and each has convexly curved surfaces. In particular, the cylindrical lens unit 23 can be formed from a glass plate, wherein the convexly curved contours of the cylindrical lenses 25 to 29 are formed by creating elongated grooves with a corresponding radius. The cylindrical lens unit 23 is thus, in particular, manufactured and formed as a single piece. On side 23b, it has a wave-like contour in cross-section, through which the adjacent, in particular straight or rod-shaped, cylindrical lenses 25 to 29 with their convex cylindrical surfaces on this side 23b are shown.

[0034] Figure 4 shows the receiver module 11. The image sensor 14, located inside the housing 13, is indicated here only by the reference numeral, but is positioned completely within the housing 13. The lens module 15 is also shown, but not yet in its adjusted final position. As can be seen from the symbolic arrows in Figure 4, not only is the roll angle adjustable with the adjustment unit 16, but adjustment and thus alignment in the three spatial directions relative to the image sensor 14 is also possible, i.e., linear adjustment in three spatial directions. This is also indicated by the arrows in Figure 4.

[0035] Once the adjusted position of the cylindrical lens unit 23 has been set, this adjusted position can be fixed. In particular, fixing using adhesive 30 is possible, as shown in Fig. 5.

[0036] Preferably, the optical module, in particular the receiver module 11, is mounted on a bearing device 31, as shown in Fig. 1, in the first housing part 3. Bearing pins are optionally arranged on the first housing part 3, in particular formed integrally with it, which engage in pin receptacles of the receiver module 11. It is also possible that, in addition to or instead of these bearing pins, a screw connection is provided in the pin receptacles to fasten the receiver module 11 to the bearing device 31. It is also possible that, in addition to or instead of this, a retaining dome 32 (Fig. 1) is provided, which is formed in the second housing part 4. The pin-like retaining dome 32 is formed integrally with the second housing part 4.In the closed state of the housing 2, with the second housing part 4 resting on the first housing part 3, this retaining dome 32 presses with its front free end against a specific location of the receiver module 11, thus creating a defined and desired downward pressure in at least this spatial direction. Several such retaining domes 32 can also be provided. Preferably, a separate positioning compensation element 33, for example a paste such as thermal paste, is arranged at the front free end of a retaining dome 32. During assembly, this positioning compensation element 33 is elastically deformable, so that tolerances can also be compensated for. In particular, this positioning compensation element 33 can subsequently be cured so that it is dimensionally rigid. This also ensures a precise fit of the receiver module 11.The positioning compensation element 33 is shown here by way of example and schematically. In addition, Fig. 1 also shows a mating connector 34, which is arranged in the housing part 4. When the housing 2 is closed, it is mechanically coupled to the electrical connector 9 and also electrically coupled via the electrical contacts located therein.

Claims

Patent claims 1. LIDAR sensor (1) for a vehicle, comprising a housing (2) in which a receiving chamber (5) is formed in which at least one optical module (11, 12) is arranged, characterized in that the optical module (11, 12) has a lens unit (15) with at least one cylindrical lens unit (23), and the optical module (11, 12) has a rotatable adjustment unit (16) with which at least the cylindrical lens unit (23) can be adjusted in at least one rotational position relative to an image sensor (14) of the optical module (11, 12) and thereby adjusted to the image sensor (14).

2. LIDAR sensor (1 ) according to claim 1 , characterized in that the cylindrical lens unit (23) is a one-piece lens with several cylindrical lenses (25 to 29).

3. LIDAR sensor (1 ) according to claim 2, characterized in that the cylindrical lens unit (23) is formed in a plate-like manner, in particular from glass, and is planar on one side (23a) and / or has a wave contour on the other side (23b) by which the curved cylindrical surfaces of the cylindrical lenses (25 to 29) are formed.

4. LIDAR sensor (1 ) according to one of the preceding claims, characterized in that the cylindrical lens unit (23) is arranged at one end (17a) of a housing (17) of the lens unit (15), in particular is arranged in a recess (24) of the housing (17) so as to be exposed towards the rear in the direction of the image sensor (14).

5. LiDAR sensor (1) according to any one of the preceding claims, characterized in that the roll angle of the cylindrical lens unit (23) relative to the image sensor (14) can be adjusted by means of the rotation position.

6. LIDAR sensor (1 ) according to one of the preceding claims, characterized in that the lens unit (15) with the adjustment unit (16) is additionally adjustable in the three spatial directions (x, y, z) to the image sensor (14).

7. LIDAR sensor (1 ) according to one of the preceding claims, characterized in that the lens unit (15) has a bandpass filter (18).

8. LIDAR sensor (1 ) according to one of the preceding claims, characterized in that the adjustment unit (16) has an adjustment ring (19) having an outer contour (20) having a gear-like structure (22), in particular for manual gripping by a person for manual adjustment of the lens unit (15).

9. LIDAR sensor (1 ) according to one of the preceding claims, characterized in that the adjustment unit (16) has an adjustment ring (19) having an outer contour (20) having several, in particular a maximum of five, in particular three, radial engagement recesses (21), in particular for engaging an adjustment arm for automatic adjustment of the lens unit (15).

10. LIDAR sensor (1 ) according to one of the preceding claims, characterized in that the adjusted position of the cylindrical lens unit (23) is held by a fixation with adhesive (30).

11. LIDAR sensor (1) according to one of the preceding claims, characterized in that the optical module is a receiver module (11).

12. Method for mounting a LIDAR sensor (1), in particular according to one of the preceding claims, comprising the following steps: Mounting an optical module (11, 12) of the LIDAR sensor (1) into a housing (2), in particular a first housing part (3), in particular into a mounting position on a bearing device (31), in particular such that a bearing pin of the first housing part (3) engages in a pin receptacle of the optical module (11, 12); Adjusting a cylindrical lens unit (23) of a lens unit (15) of the optical module (11 , 12) relative to an image sensor (14) of the LIDAR sensor (1) by rotating an adjustment unit (16) and thereby setting an adjusting rotational position of the cylindrical lens unit (23); In particular, fixing the adjusted position of the cylindrical lens unit (23) to the image sensor (14) by applying an adhesive (30) and creating a fixing adhesive connection between the lens unit (15) and a housing (13) that accommodates the image sensor (14).

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