DE102021126105A1 - SENSOR UNIT AND VEHICLE - Google Patents

Abstract

A sensor unit (2) for a vehicle (1) is provided, comprising: an optical sensor (7); and an optical element (13) arranged in front of the optical sensor (7), the optical element (13) having a convex surface (20, 20') facing away from the optical sensor (7) and a concave surface (21) facing the optical sensor (7), the convex surface (20, 20') having a larger radius of curvature (R, R') than the concave surface (21); the convex surface (20, 20') having a shape that is not rotationally symmetrical about an axis (A) that intersects the optical element (13) and the optical sensor (7).

Description

The present invention relates to a sensor unit for a vehicle and a vehicle with such a sensor unit.

Optical sensors are often used in the automotive industry to monitor the vehicle's external environment. Such optical sensors typically include cameras or lidars.

It is desirable to have optical sensors with a large horizontal field of view (FOV), ideally up to 180° or more. In order to achieve a large field of view, it is known to use optical sensors in conjunction with a fisheye lens. Such constructions allow a field of view of more than 200°, for example. It has been shown that such designs also have a large vertical field of view. This results in the optical sensor collecting worthless information as under normal circumstances there is no obvious reason to monitor the sky or the road directly below the vehicle.

The U.S. 2018/0249126 A1 discloses a vehicle identification arrangement with a vehicle identification element which is designed for attachment to a vehicle. The vehicle identification element includes a light-transmissive portion. A vehicle camera, including a fisheye lens, is positioned on the vehicle landmark such that the vehicle camera views through the translucent portion and is operable to capture image data.

The US 2018/0335622 A1 discloses an apparatus for an optical sensor for a motor vehicle. The device includes a housing in which the optical sensor is housed. The housing further has an optical element attached thereto. The optical element has at least one flat surface which is designed to be arranged in the field of view of the optical sensor. The optical sensor may include a fisheye lens.

It is an object of the present invention to provide an improved sensor unit.

According to a first aspect, a sensor unit is provided, which comprises an optical sensor and an optical element. The optical element is arranged in front of the optical sensor, the optical sensor having a convex surface facing away from the optical sensor and a concave surface facing the optical sensor, the convex surface having a larger radius of curvature than the concave surface. The convex surface has a shape that is not rotationally symmetrical about an axis that intersects the optical element and the optical sensor.

An image corresponding to a variable field of view can be projected onto the optical sensor by the convex surface having a shape that is not rotationally symmetrical about an axis that intersects the optical element and the optical sensor. For example, the vertical field of view may have a different angle (or width) than the horizontal field of view. More generally, using a convex surface with the shape defined above, the field of view can be adjusted or provided in any direction according to information needs. For example, the axis can intersect a light-sensitive element (particularly a chip) of the optical sensor at right angles.

The sensor unit can be particularly suitable for use in a vehicle. Examples of vehicles are automobiles such as a motorcycle, car, truck, or bus; rail vehicles such as a train or tram; watercraft such as ships or boats; an amphibious vehicle such as a propeller driven vehicle or a hovercraft; an aircraft such as an airplane or a helicopter; or spacecraft. Examples of vehicles may also include a robot, such as an industrial robot, an autonomously driving robot, and the like.

An “optical sensor” is a sensor configured to emit an electrical signal in response to light (visible or invisible) received by the sensor.

According to one embodiment, the convex surface comprises a portion of a cylinder surface. In particular, the cylinder surface has an axis of rotational symmetry.

For example, the cylinder surface may have one or more axes of rotational symmetry. In particular, the cylinder surface can have exactly one axis of rotational symmetry. A cylinder surface is advantageously formed with, for example, exactly one axis of rotational symmetry in order to provide a large horizontal field of view and a small vertical field of view. At the same time, this type of cylinder surface is easy to manufacture.

A "cylinder surface" here refers to a surface created by moving a Curve is generated in a first plane along a straight line into a second plane, the straight line being located outside the first plane. The lines connecting the curve in the first and second planes form the cylinder surface.

According to another embodiment, the convex surface may comprise a portion of an ellipsoidal surface. For example, the optical element is shaped as a section of an ellipsoid, which on its outside includes the section of the ellipsoid surface.

According to a further embodiment, the optical element is shaped as a cylindrical section which has the section of the cylinder surface on its outside.

That is, the optical element is shaped as a portion of a cylinder as a whole. In particular, the cylindrical section corresponds to a section of a hollow cylinder. In this way, an optical element having the concave and convex surfaces defined above can be easily manufactured.

According to a further embodiment, the cylindrical portion corresponds to a longitudinally cut portion of a hollow cylinder, the cut intersecting the cylinder side wall twice.

"Longitudinal direction" refers to the axial direction of the hollow cylinder. In embodiments, this is the axis about which the hollow cylinder is rotationally symmetrical. An optical element with this shape can be easily manufactured, for example by casting, injection molding or extrusion.

According to a further embodiment, the optical element is a protective cover.

The optical element thus has a dual function: in addition to its optical properties, the optical element protects the optical sensor. For example, it prevents external mechanical forces from acting on the optical sensor and/or it can prevent dust, dirt and other unwanted materials from getting on the optical sensor.

According to a further embodiment, the optical element is designed to be mounted on the outside of a vehicle body.

For example, the optical element may have male and/or female elements, such as hooks, clips, receptacles, and the like, for attachment to the exterior of the vehicle body.

According to a further embodiment, the optical element is made of a transparent material.

For example, the optical element can be made of glass or plastic. "Transparent" means that the optical element allows light from the external environment, in particular from the environment of a vehicle, to pass through to the optical sensor.

According to a further embodiment, the optical element is a lens.

According to a further embodiment, the optical sensor comprises a lens, with an image plane of the sensor unit being arranged behind the lens.

Advantageously, in this embodiment, the optical element can be designed to shape in any suitable way the light that strikes the (outer) convex surface and then passes through it and exits the optical element through the (inner) concave surface. This means that no image plane can be arranged directly behind the optical element. Rather, the optical sensor itself includes a lens that converts the light coming from the optical element in such a way that the original image is restored.

According to a further embodiment, the optical sensor comprises a housing and/or a chip, the lens being connected to the housing and/or the chip or being formed in one piece with it.

The optical sensor thus forms a unit together with the lens. This unit can be separate and/or spaced from the optical element. In particular, the chip includes a light-sensitive element that generates an electrical signal as a function of light impinging on the chip.

According to a further embodiment, the optical sensor is a camera or lidar.

Specifically, the optical sensor includes, for example, a CCD (charge coupled device) or CMOS (complementary metal oxide semiconductor) chip (in the case of a camera). "Lidar" refers to a technique that calculates distances based on a transmitted laser signal and an optical one Sensor received reflected signal are determined.

According to a further embodiment, the sensor unit has a field of view of more than 120°, preferably more than 150° and even more preferably more than 180°.

The sensor unit is configured to provide the field of view in the horizontal direction when mounted on a vehicle. The field of view in the vertical direction will thus be smaller than the field of view in the vertical direction.

According to a second aspect, a vehicle is provided with the sensor unit described above.

According to one embodiment, the axis about which the shape is not rotationally symmetrical is oriented horizontally.

The horizontal direction corresponds to the typical viewing direction of cameras or lidars in the automotive sector. In the present case, "horizontal" also includes deviations from exactly horizontal of, for example, up to 10, 20 or 30 degrees.

According to a further embodiment, the axis of symmetry is aligned vertically.

This allows a large field of view to be achieved in the horizontal direction. In the present case, "vertical" also includes deviations from exactly vertical of, for example, up to 10, 20 or 30 degrees.

According to a further embodiment, the vehicle further comprises a vehicle body, the optical element being arranged outside the vehicle body and the optical sensor being arranged inside the vehicle body.

This is advantageous in that the optical element ensures a large field of view outside the vehicle body, while at the same time the optical sensor is securely arranged inside the vehicle body.

According to a further embodiment, the sensor unit has a horizontal field of view and a vertical field of view, the horizontal field of view being larger than the vertical field of view.

This avoids that unnecessary data is recorded by the sensor unit.

Features explained above in relation to the first aspect also apply to the second aspect and vice versa.

Other possible implementations or alternative solutions of the invention also include combinations—which are not explicitly mentioned here—or features that are described above or below with regard to the embodiments. Those skilled in the art can add single or isolated aspects and features to the simplest form of the invention.

• 1 ein Ausführungsbeispiel eines Fahrzeugs in einer Vorderansicht zeigt;
• 2 einen Schnitt II-II aus 1 zeigt;
• 3 einen Strahlenverlauf durch ein in 2 dargestelltes optisches Element in einer Draufsicht zeigt;
• 4 einen Strahlenverlauf für das optische Element aus 3 in einer Seitenansicht zeigt;
• 5 die Schnittansicht von 2 gemäß einer weiteren Ausführungsform zeigt;
• 6 die Schnittansicht von 2 gemäß einer weiteren Ausführungsform zeigt; und
• 7 die Ausführungsform von 6 in einer Seitenansicht zeigt.

Further embodiments, features and advantages of the present invention result from the following description and the dependent claims in connection with the accompanying drawings, wherein:

• 1 shows an embodiment of a vehicle in a front view;
• 2 a section II-II 1 shows;
• 3 a ray path through an in 2 shows the optical element shown in a plan view;
• 4 a beam path for the optical element 3 shows in a side view;
• 5 the sectional view of 2 according to another embodiment;
• 6 the sectional view of 2 according to another embodiment; and
• 7 the embodiment of 6 shows in a side view.

In the figures, the same reference symbols designate the same or functionally equivalent elements, unless otherwise stated.

1 12 shows an embodiment of a vehicle 1 according to an embodiment. According to the embodiment, the vehicle 1 is a passenger car.

The vehicle 1 includes a sensor unit 2 which is only shown as an example, the sensor 2 being integrated into the front of the vehicle 1 . However, the sensor unit 2 or several sensor units 2 can also be integrated in other parts of the vehicle, for example in the vehicle sides or in the vehicle rear, in the vehicle mirrors or in or at any other suitable position.

2 shows a section II-II 1 . The sectional view in 2 12 shows part of the vehicle body 3. The vehicle body 3 may be made of sheet metal, plastic or the like. The vehicle body 3 has an opening 4 that connects the interior 5 of the vehicle body 3 to the outside or exterior 6 .

According to the embodiment, the sensor unit 2 comprises an optical sensor 7, which according to the embodiment of FIG 2 is a camera. The optical sensor 7 is, for example, at least partially arranged inside the opening 4 formed as a through hole inside the vehicle body 3, for example.

The optical sensor 7 can comprise a lens 8, a housing 9 and a light-sensitive element 10. According to the embodiment of 2 , in which the optical sensor 7 is designed as a camera, the light-sensitive element 10 is designed, for example, as a CCD or CMOS chip. The light-sensitive element 10 is arranged, for example, inside the housing 9, which is why it is shown in phantom. The lens 8 is designed to project light 11 coming from the outside or from the outside 6 onto the light-sensitive element 10 . In particular, there is an image plane 12 formed behind lens 8 . "Behind" and "in front" here refers to the light 11 that passes through the respective optical elements.

The lens 8 can be connected to the housing 9 and/or to the light-sensitive element 10 or can be designed in one piece. In general, the light-sensitive element 10 is designed to generate an electrical signal as a function of the incident light 11 .

An optical element 13 is arranged on the outside 14 of the vehicle body 3 . The optical element 13 can be connected directly to the vehicle body 3, for example by means of clips (not shown), or to an intermediate component which is connected to the vehicle body 3. In an embodiment (also not shown), the optical element 13 can also be connected to the optical sensor 7, for example to the housing 9 of the optical sensor 7.

The optical element 13 is made of, for example, a transparent material, for example a transparent plastic material or glass. The optical element 13 can be designed as a lens.

The optical element 13 covers the optical sensor 7 . In particular, the optical element 13 encloses the lens 8. In one embodiment, the optical element 13 completely covers the opening 4, which prevents dust and other contaminants from entering and reducing or impairing the functionality of the optical sensor 7. According to one embodiment, the optical element 13 can also be referred to as a protective cover. As such, it prevents external mechanical forces 6 from acting on the optical sensor 7 .

The optical element 13 has a fisheye shape in the horizontal direction H, which is explained below with reference to FIG 3 and 4 is explained in more detail.

3 shows the ray path for the light rays 15, 16, 17 (which are part of the incident light 11). while showing 3 the optical element 13 off 2 in a top view. 4 shows another beam path for the optical element 13, the element being shown in a slightly perspective side view. Additional beams 18 and 19 are shown therein. In 3 and 4 the rays that have passed through the optical element 13 are marked with "'".

The optical element 13 has a convex surface 20 (see 3 ), which faces away from the optical element 7 (see 2 ). The optical element 13 also includes a concave surface 21 (see FIG 3 ) facing the optical element 7 (see 2 ). The convex surface 20 has a radius R (only the tip of which is shown). The concave surface 21 also has a radius r (again, only one tip is shown). The radius R is larger than the radius r. The radii R, r both lie in the horizontal plane P _H . The horizontal plane corresponds to the plane defined by the longitudinal and lateral directions of the vehicle.

At least the convex surface 20 has a shape that is not rotationally symmetrical about an axis A (see FIG 2 and 3 ). The axis A intersects the optical element 20 and the optical sensor 7. In particular, the axis A can intersect the light-sensitive element or chip 10, for example at right angles. According to the embodiment, the convex surface 20 includes a portion 22 (see FIG 4 ) a cylinder surface with, for example, a single axis of rotational symmetry 23 (see 4 ). The section 22 is formed by shifting a first line 24 parallel by a (straight) distance 25 so that a second line 26 is formed. All straight lines 25 connecting lines 24, 26 form section 22.

According to the example of 3 and 4 For example, the concave surface 21 is also a portion of a cylinder surface having a rotationally symmetrical axis (not shown). Thus, the optical element 13 is shaped as a whole as a cylindrical portion having the convex surface 20 on its outside and the concave surface 21 on its inside. The cylindrical portion 27 is obtained, for example, geometrically, by a section along the longitudinal direction L of a hollow cylinder 28 (the hollow cylinder 28 is shown in phantom), the section showing the sides of the cylinder wall (or cylinder surface) intersects twice. The points of intersection are marked with the reference numbers 29 and 30 . The longitudinal direction L corresponds to the vertical direction V in which the distance 25 (vector) is aligned.

According to a further embodiment, which is 4 is not shown in detail, the optical element 13 has a convex surface 20' which is not straight in the vertical direction V but has a radius of curvature R' in the vertical plane P _V which is greater than that of the curvatures R The convex surface 20' may correspond to an ellipsoidal surface. The optical element 13 can be designed as a section of an ellipsoid.

Both embodiments (concave surface 20, 20') provide the desired effect. This effect is due to the course of the rays 3 and 4 illustrated. In the horizontal plane P _H ( 3 ), the optical element 13 provides a large field of view of, for example, 180°, as indicated by the angle α. In the vertical plane P _V ( 4 ), on the other hand, the field of view is limited to an angle of, for example, 60°, as indicated by the angle β in 4 implied.

5 shows the embodiment of 2 . However, in this embodiment, the optical sensor 7 is arranged entirely inside the vehicle body 3 . As both in 2 as well as in 5 can be seen, the optical sensor 7 is spaced from the optical element 13, the distance in 5 is larger than in 2 .

6 shows an embodiment that cut out 2 is equivalent to. However, the optical sensor 7 is designed as a lidar. As such, the optical sensor 7 comprises, for example, a transmitter 31 and a receiver 32, as shown in a side view in FIG 6 and in 7 shown. The transmitter 31 emits a laser beam (not shown), which is reflected by the measurement object (not shown). The reflected beam is received by receiver 32 . The distance to the measurement object is determined based on the transit time.

Although the present invention has been described with reference to certain exemplary embodiments, it can be modified in many ways.

reference list

1

vehicle

2

sensor unit

3

vehicle body

4

opening

5

Inside

6

Outside

7

optical sensor

8th

lens

9

Housing

10

photosensitive element

11

incident light

12

picture plane

13

optical element

14

outside

15-19, 15'-19'

rays of light

20, 20'

convex surface

21

concave surface

22

Section

23

axis of symmetry

24

line

25

Distance

26

line

27

Section

28

hollow cylinder

29

crossing point

30

crossing point

31

Channel

32

Recipient

H

horizontal direction

L

longitudinal direction

PH

horizontal plane

PV

vertical plane

R, R'

radius

R

radius

V

vertical direction

a

Angle/horizontal field of view

β

Angle/vertical field of view

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• US20180249126A1 [0004]
• US20180335622A1 [0005]

Claims (15)

Sensor unit (2) for a vehicle (1), comprising: an optical sensor (7); and an optical element (13) arranged in front of the optical sensor (7), the optical element (13) comprising a convex surface (20, 20') facing away from the optical sensor (7) and a concave surface (21) facing the optical sensor (7), the convex surface (20, 20') having a larger radius of curvature (R, R') than the concave surface (21); the convex surface (20, 20') having a shape that is not rotationally symmetrical about an axis (A) that intersects the optical element (13) and the optical sensor (7). sensor unit claim 1 , wherein the convex surface (20, 20 ') comprises a portion (22) of a cylindrical surface, which preferably has an axis of rotational symmetry (23). sensor unit claim 2 , wherein the optical element (13) is shaped as a cylindrical section (27) which has the section (22) of the cylinder surface on its outside. sensor unit claim 3 , wherein the cylindrical section (27) corresponds to a section of a hollow cylinder (28) cut in the longitudinal direction (L), the cut intersecting the cylinder side wall twice (29, 30). Sensor unit according to one of the preceding claims, in which the optical element (13) is a protective cover and/or is designed to be mounted on the outside of a vehicle body (3). Sensor unit according to any of the preceding claims, wherein the optical element (13) is made of a transparent material and/or is a lens. Sensor unit according to one of the preceding claims, in which the optical sensor (7) comprises a lens (8), an image plane (12) of the sensor unit (2) being arranged behind the lens (8). sensor unit claim 7 , wherein the optical sensor (7) further comprises a housing (9) and/or a chip (10), wherein the lens (8) is connected to the housing (9) and/or the chip (10) or formed in one piece therewith . Sensor unit according to one of the preceding claims, in which the optical sensor (7) is a camera or a lidar. Sensor unit according to one of the preceding claims, wherein the sensor unit has a field of view (α) of more than 120 degrees, preferably more than 150 degrees and even more preferably more than 180 degrees. Vehicle (1) comprising the sensor unit (2) according to any one of the preceding claims. vehicle after claim 11 , where the axis (A), about which the shape is not rotationally symmetrical, is oriented horizontally. vehicle after claim 11 or 12 , wherein the axis of rotational symmetry (23) is oriented vertically. vehicle after one of Claims 11 until 13 , further comprising a vehicle body (3), wherein the optical element (13) is arranged outside the vehicle body (3) and the optical sensor (7) is arranged inside the vehicle body (3). vehicle after claim 12 or 13 , wherein the sensor unit (2) has a horizontal field of view (α) and a vertical field of view (β), the horizontal field of view (α) being larger than the vertical field of view (β).

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