EP3311190A1

EP3311190A1 - Sensor system of a sensor device of a motor vehicle

Info

Publication number: EP3311190A1
Application number: EP16731560.5A
Authority: EP
Inventors: Nadine Sticherling
Original assignee: Huf Huelsbeck and Fuerst GmbH and Co KG
Current assignee: Huf Huelsbeck and Fuerst GmbH and Co KG
Priority date: 2015-09-08
Filing date: 2016-06-16
Publication date: 2018-04-25
Also published as: DE102015115101A1; WO2017041915A1; CN108139466A

Abstract

The invention relates to a sensor system (3) of a sensor device (4) of a motor vehicle (1) for optical detection of objects and their spatial movements, comprising a 3D camera which captures spatial data using a transit time method and which comprises a light source (6) and a light-sensitive receiving device (7), wherein the light source (6) and the light-sensitive receiving device (7) can be arranged in a common sensor housing (5) and are both aligned with a detection region (8) of the 3D camera, wherein a solution is achieved which provides a homogeneous illumination of the detection region of the 3D camera. This is achieved in that the light source (6) comprises a transmission optic (21) for the predetermined dispersion of the emitted light, wherein the transmission optic (21) comprises a first lens (22) and a second lens (23) which is arranged behind the first lens (22) in the direction of the emitted light, wherein at least one boundary surface (33) of at least one of the two lenses (22, 23) is designed as a free-form surface (32).

Description

Sensor system of a sensor device of a motor vehicle

The invention is directed to a sensor system of a

Sensor device of a motor vehicle for the optical detection of objects and their spatial movements, comprising a 3D camera that detects spatial data with a transit time method and the light source and a light-sensitive

Receiving device comprises, wherein the light source and the light-intensive receiving device in a common

Sensor housing can be arranged and both to one

Detection range of the 3D camera are aligned.

Such a sensor system with such a sensor device is lately for optically supported detection of

Operating gestures or operations on motor vehicles used. Thereby temporally and spatially resolved

Information collected and evaluated to recognize a user's will to operate as a gesture or action.

In the prior art, optical methods are known which perform operations in response to evaluation of

Recognize image information and then, for example

Trigger switching operations. By way of example, automatic video evaluations of surveillance systems can be mentioned here, which read out patterns or movements from individual images or a sequence of images. In addition, many other optically-based systems are known, with the most basic systems including, for example, light barriers or brightness sensors. However, optical systems of higher complexity often use an array of optically sensitive detection units, usually referred to as pixels, which receive optical information in parallel, for example in the form of a CCD array.

DE 10 2008 025 669 A1 discloses an optical sensor which detects a gesture, whereupon a closing element of a vehicle is automatically moved.

WO 2008/116699 A2 relates to an optical sensor chip and relates to an optical anti-pinch device for the monitoring of a window, sliding door or a tailgate in a motor vehicle.

WO 2012/084222 A1 discloses an optical sensor for actuating and monitoring a closing element.

Because the gesture control in different technical

Experiencing areas of increasing acceptance, attempts have also been made to use such purely optical systems for detecting the desire to operate in motor vehicles. However, these systems continue to have control over capacitive systems.

In the field of optical detection systems are known which detect a pixel-related location information, in particular a distance from the sensor or detection device. WO 2013/001084 A1 discloses a system for contactless

Detection of objects and operating gestures with an optically supported device of a similar kind, as they are also for the

Sensor system of the present invention is used.

These systems are called, for example, depending on the applied evaluation method, as a "time-of-flight" systems or as a "3D Imager" or "Range Imager"

Areas of application of such systems are in the field of

industrial automation technology, in safety technology and in the automotive sector. In a car, 3D sensors are used in lane keeping systems, for pedestrian protection or as a parking aid. Both concepts of triangulation and the

Interferometry and time-of-flight (ToF) can be implemented with optical sensors.

In this context, it is referred to

For further details, please refer to the dissertation "Photodetectors and readout concepts for 3D time-of-flight image sensors in 0.35 pm standard CMOS technology", Andreas Spickermann, Faculty of Engineering , University of Duisburg-Essen, 2010.

In addition, the publication "Optimized Distance

Measurement with 3D-CMOS Image Sensor and Real-Time Processing of 3D Data for Applications in Automotive and Safety Engineering ", Bernhard König, Faculty of

Engineering Sciences of the University of Duisburg-Essen, 2008.

The aforementioned work describes the concept and the realization of deployable optical sensor systems, so that in the context of this application reference is made to their disclosure and only to the understanding of the application relevant aspects

be explained.

The invention relates to a sensor system and a

Sensor arrangement, which uses the time-of-flight (ToF) method, so that this is briefly explained here.

The ToF method is a space area with a

Illuminated light source and recorded the duration of the reflected back from an object in the space area light with an area sensor. For this purpose, the light source and sensor should be arranged as close as possible to each other. The distance between the sensor and the object to be measured can be determined from the linear relationship between the light transit time and the speed of light. To measure the time delay must be a synchronization between

Be given light source and sensor. Through the use of pulsed light sources, the procedures can be optimized, because short light pulses (in the ns range) allow an efficient

Background light suppression. In addition, by the

Using the pulsed light possible ambiguities in determining the distance avoided as long as the distance is sufficiently large.

On the one hand, the light source is pulsed in this concept. In addition, the detection unit, so the

Pixel array, pulsed sensitively switched. In other words, the integration window of the individual pixels is synchronized in time with the light source and in the integration period

limited. By comparing results with

different integration periods, in particular effects of background light can be excluded.

It is essential that this collection method is not a purely image-based acquisition method. It is determined at each pixel distance information, which by the temporal Light detection takes place. Finally, when using a pixel array, there is a matrix of distance values that allows for cyclic detection interpretation and tracking of object motion.

A sensor system of the type designated input is for

Example from DE 10 2013 108 824 AI known. In this known sensor system, the sensor device is integrated together with the light source and the receiving or detecting device into a unit in a sensor housing, which is mountable on the motor vehicle. A disadvantage of this prior art is that emitted by the light source

Light beam is obliquely aligned with the detection area and incident on this. This results in the area in front of the vehicle, i. the detection area, inhomogeneously illuminated by the light source, causing problems in the

Detection of objects in the detection area.

The invention has for its object to provide a solution that provides a sensor system in a structurally simple manner and cost, which avoids the known from the prior art problem and for a homogeneous

Illumination of the detection range of the 3D camera ensures, so that the detection area experiences a uniform light intensity.

In a sensor system of the type described input, the object is achieved in that the light source has a transmitting optics for predetermined dispersion of the emitted light, wherein the transmitting optics, a first lens and a second lens, which is arranged in the direction of the emitted light behind the first lens , wherein at least one interface of at least one of the two lenses as

Freeform surface is formed.

Advantageous and expedient embodiments and

Further developments of the invention will become apparent from the

Subclaims.

By the invention, a sensor system is provided, which is characterized by a functional design. Characterized in that at least one interface of at least one of the two lenses formed as a free-form surface is, by a suitable design of the free-form surface or free-form surfaces targeted the illumination of the

Be entered. For the present

Application of the optical detection of objects and their

spatial movements, i. of motion gestures, is homogeneous by the measure of at least one free-form surface

Ensuring illumination of the detection area, ensuring a safe and high-resolution detection of objects in the

Detection range of the 3D camera is guaranteed, which consequently leads to a total of high performance of the

Sensor device is obtained in terms of detection reliability and detection sensitivity.

In order to improve the machinability of the transmitting optics, it is advantageous in an embodiment of the invention if at least one of the two lenses is quadrangular. A quadrangular

Lens can be used to edit the interfaces easier and more precise clamping than a disc-shaped lens.

The invention provides in a further embodiment that at least one of the two lenses is rectangular. By a rectangular formation of the one lens or the two lenses, an exact positioning or arrangement of the corresponding lens in the transmitting optics is possible, so that an incorrect alignment of the lens or the lenses is no longer possible because the long sides and the broad sides

are different lengths.

In a further embodiment of the invention it is provided that the first lens with inwardly curved interfaces

is trained. The first lens thus acts in the

Sensor system as expansion optics and enlarges the from

emitted light generated cones.

For a targeted expansion of the light, it is advantageous in an embodiment of the invention, when the inwardly curved boundary surfaces of the first lens two-dimensional

Are vaults that extend along a first spatial direction. Thus, the emitted light can be expanded in a first axis or spatial direction after a predetermined dispersion. For diffusing the light through the first lens, it is further provided in an embodiment of the invention that the radius of curvature of the curvature of the curvature of the second lens

remote interface of the first lens is smaller than the radius of curvature of the curvature of the second lens facing interface of the first lens.

In an advantageous embodiment of the second lens, the invention provides for the second lens to be an inward one

having a curved interface and an interface formed as a free-form surface. The trained as a freeform surface

Interface allows a targeted illumination of the

Detection range of the 3D camera, so that the detection area can now be illuminated with homogeneous light intensity.

For targeted expansion of the light beam in one

desired axis or spatial direction, it is advantageous in the embodiment of the second lens when the first lens

facing interface of the second lens is a two-dimensional curvature extending transversely to the bulges of the first lens. Accordingly, the first lens provides for a

Widening of the light in a first spatial direction, whereas the expanded light from the second lens into a second spatial direction

Spatial direction, which is transverse to the first spatial direction, is widened. The light is thus widened by means of the two lenses in different axes.

In an embodiment of the invention is then further provided that the remote from the first lens interface of the second lens has the free-form surface, wherein the free-form surface is formed two-dimensionally. The two-dimensional design causes the expansion in the desired spatial direction or

Axis.

With regard to a targeted distribution of the light intensity in the detection range of the 3D camera, the invention provides in a further embodiment, that the area change of the free-form surface extends transversely to the curvatures of the first lens, wherein the area change from a to be achieved

Homogeneous brightness distribution in the detection range of the SD camera derived. For the field of application on a motor vehicle, the inventors have found that it is of particular advantage for a homogeneous illumination of the detection area if the second lens substantially has the shape of the number seven.

It is understood that the above and

hereinafter to be explained features not only in the combination specified, but also in others

Combinations or alone, without departing from the scope of the present invention. The scope of the invention is defined only by the claims.

Further details, features and advantages of the subject matter of the invention will become apparent from the following description taken in conjunction with the drawing, in which an example

preferred embodiment of the invention is shown. In the drawing shows:

FIG. 1 shows a schematic arrangement of a sensor system according to the invention on a motor vehicle,

FIG. 2 is a perspective view of the sensor system according to the present invention;

Figure 3 is a schematic representation of an inhomogeneous

Illumination of a detection area,

FIG. 4 shows a light source of the sensor system according to the invention in perspective view,

FIG. 5 is an exploded perspective view of FIG

Light source of the sensor system according to the invention,

FIG. 6 shows an exploded view of a transmission optics of the light source of the sensor system according to the invention,

7 shows a schematic representation of a beam path of the light source of the sensor system in a plan view,

FIG. 8 shows a perspective plan view of the transmission optics of FIG

Light source of the sensor system according to the invention,

9 shows a schematic representation of a beam path of the light source of the sensor system in a side view and

FIG. 10 shows a perspective side view of the transmission optics of the light source of the sensor system according to the invention.

In Figure 1, the rear of a motor vehicle 1 can be seen. In this motor vehicle 1 is in the rear-side Bumper, which is a motor vehicle component 2 of the motor vehicle 1 in the context of the invention, a sensor system 3 is arranged. The sensor system 3 comprises a sensor device 4 and a sensor housing 5 accommodating the sensor device 5

Sensor device 4 itself has a 3D camera, the

recorded spatial data with a transit time method and comprising a light source 6 and a light-sensitive receiving device 7. The detection area 8 of the 3D camera of

Sensor device 4 is directed downward, to the sides and to the rear of the motor vehicle 1 away, wherein the sensor system 3 is provided to detect the operating gesture for the operation of a tailgate. This can be done by the user in the

Detection area 8 perform a gesture with his foot, which is recognized as a control request and an electric opening of the

Tailgate of the motor vehicle 1 triggers. The control,

Evaluation and supply of the sensor device 4 via a uniform wiring harness, in particular a

Plug connection 9 is provided on the sensor housing 5 for coupling to a cable harness.

The entire detection area 8 of the 3D camera or the

Sensor device 4 extends over a large solid angle, as is apparent from Figures 1 and 2, wherein in Figure 2 in a perspective view, the sensor housing 5 and the cone of the light emitted from the light source 6 is shown. FIG. 3 shows a biaxial diagram in which the sensor device 4 and the detection region 8 illuminated by the light source 6 are shown schematically, the dashed lines representing the outer light beams confining the light cone. The solid line in the diagram of FIG. 3 represents the light intensity 10, with which the light source 6 covers the detection area 9

illuminates. As can be seen from the diagram in FIG. 3, the detection area 8 does not become homogeneous

Intensity illuminated. Rather, it behaves so that with increasing distance 11 (x-axis of the diagram in Figure 3) from the motor vehicle 1, the intensity 12 (y-axis of the diagram in Figure 3) of the light decreases. The diagram in FIG. 3 shows In this case, a state as known from the prior art. In contrast, with the present invention, such an inhomogeneity (line 10) is avoided and a homogeneous illumination of the detection area 8 is achieved, as shown by the dashed line 14 in FIG. 3, because here is the FIG

Light intensity 10 'over the detection area 8 constant. This homogeneous illumination of the detection area 8 is based on the particular embodiment of the light source 6 of the sensor system 3 according to the invention, which will be discussed below.

The light source 6 is shown in perspective in FIG

View and shown in Figure 5 in a single part view. The light source 6 comprises a housing 15 and a cover 16 closing the housing 15 to one side, with a transparent window 17, through which light from the

Light source 6 is emitted. For adjustment purposes, the light source 6 further comprises an annular adjusting element 18, which is seated on a retaining sleeve 19. Within the retaining sleeve 19, a light emitting unit 20 and a transmitting optics 21 is then arranged one behind the other, as can be seen from Figures 5 and 6.

As can be seen in FIGS. 5 and 6, FIG

Transmission optics 21, the predetermined dispersion of the

emitted light is used, a first lens 22 and a second lens 23, which is arranged in the direction 24 of the emitted light behind the first lens 22. The two lenses 22, 23 are formed square in the illustrated embodiment. In particular, the two lenses 22, 23 are rectangular

formed, wherein the lenses 22, 23 whose respective height is greater than the respective width. In FIGS. 7 and 9, the beam path of the light emission unit 20 is shown

emitted light is shown by both lenses 22, 23, wherein the figure 7, the beam path in a plan view and Figure 9 show the beam path in a side view. FIGS. 8 and 10 show the transmitting optics 21, wherein FIG. 8 shows a plan view corresponding to FIG. 7 and FIG. 10 shows a side view corresponding to FIG. 9 on the transmitting optics 21. As can be seen from FIGS. 6 to 10, the first lens 22 is provided with inwardly curved interfaces 25 and 26

educated. The first interface 25 of the first lens 22 is provided with an inwardly directed curvature 27, which is formed two-dimensionally, so that the curvature 27 is formed as a round and in a first spatial direction 28 extending recess on the otherwise flat surface of the interface 25. The other interface 26 of the first lens

22 is also formed two-dimensional, with their inwardly directed curvature 29 also in the first

Spatial direction 28 extends (see, for example, Figure 8). The radius of curvature of the curvature 27 is that of the second lens

23 remote interface 25 of the first lens 22 is smaller than the radius of curvature of the curvature 29 of the second lens 23 facing interface 26 of the first lens 22. This

Two-dimensional configuration of the two boundary surfaces 25 and 26 of the first lens 22 leads to that in FIGS. 7 and 9

shown expansion of the emitted light beam, as the beam path 30 shows. In order to realize a homogeneous illumination of the detection area 8, the second lens 23 has an inwardly curved interface 31 and one as

Free-form surface 32 formed interface 33 on. The inwardly directed curvature 34 (see, for example, FIG. 10), which on the first lens 22 faces the boundary surface 31 of the second lens 23, extends in a second spatial direction 35, which extends transversely to the first spatial direction 28 that the boundary surface 31 is formed two-dimensionally. Thus, the bulge 34 of the interface 31 of the second lens 23 extends transversely to the bulges 27, 29 of the first lens 22. This inward bulge 34 of the interface 31 causes a further symmetrical expansion of the light beam within the second lens 23. The interface 33 with the

In contrast, the free-form surface 32 causes an asymmetrical widening of the light beam along the first spatial direction 28, as can be seen, for example, from FIG. 9. In this case, the point 36 represents a vehicle-near area of the detection area 8 and the point 37 is a vehicle-remote area of the detection area 8, such as from the synopsis of Figures 1, 3 and 9 can be seen. It should be noted that the detection area 8 in FIG. 7 is the

Distribution of the light beams in the width direction of the vehicle 1 reproduces. As FIG. 9 shows in particular, due to the particular configuration of the boundary surface 33, FIG

Freiformfläche 32 achieves an intensity shift in the direction of the vehicle-distant region 37, which is indicated at the distance between the individual beams. According to the invention, the shape of the free-form surface 32 shifts the intensity of the region 36 close to the vehicle in the direction of the area remote from the vehicle, in order to ensure homogeneous illumination of the vehicle

Detection range 8 to achieve. For this reason, the area change of the free-form surface 32 also extends transversely to the bulges 27, 29 of the first lens 22. As shown in FIG. 10, in the exemplary embodiment shown, the second lens 23 essentially has the shape of the number seven, whereby also deviating designs are conceivable as long as the shape of the second lens 23 and in particular of the free-form surface 32 achieves a homogeneous brightness distribution in the detection region 8 of the 3D camera.

In summary, it is the core idea of the invention that the light source 6 a transmitting optics 21 to the predetermined

Has scattering of the emitted light, wherein the

Transmitting optics 21, a first lens 22 and a second lens 23, which is arranged in the direction 24 of the emitted light behind the first lens 22, wherein at least one interface 33 of at least one of the two lenses 22, 23 as

Free-form surface 32 is formed. This leads the

Area change of the free-form surface 32 from a homogeneous distribution of brightness to be achieved in the detection area 8 of the 3D camera. With the aid of the above-described sensor system 3 and the transmission optics 21 according to the invention, an expansion of the light beam into different spatial axes 28, 35 is possible.

In this case, the light can be individually expanded for each spatial axis 28, 35.

Of course, the above-described invention is not limited to the embodiment described and illustrated limited. It can be seen that in the embodiment shown in the drawing numerous, the expert

according to the intended application obvious

Amendments can be made without departing from the scope of the invention. The invention includes everything that is contained in the description and / or shown in the drawing, including what, deviating from the specific embodiment for the skilled person

close.

Claims

claims

1. Sensor system (3) of a sensor device (4) of a motor vehicle (1) for the optical detection of objects and their spatial movements, comprising a 3D camera that detects spatial data with a transit time method and a light source (6) and a light-sensitive

Receiving device (7) comprises,

the light source (6) and the light-intensive

Receiving device (7) can be arranged in a common sensor housing (5) and both are aligned to a detection area (8) of the 3D camera,

characterized,

the light source (6) has a transmission optics (21) for

predetermined emission of the emitted light, wherein the transmitting optics (21) a first lens (22) and a second lens (23) which is arranged in the direction of the emitted light behind the first lens (22), wherein at least one interface ( 33) of at least one of the two lenses (22, 23) is designed as a free-form surface (32).

Second sensor system (3) according to claim 1, characterized

in that at least one of the two lenses (22, 23) is quadrangular.

3. sensor system (3) according to claim 1 or 2, characterized in that at least one of the two lenses (22, 23) is rectangular.

4. Sensor system (3) according to one of the preceding

Claims, characterized in that the first lens (22) is formed with inwardly curved boundary surfaces (25, 26).

5. Sensor system (3) according to claim 4, characterized

characterized in that the inwardly curved boundary surfaces (25, 26) of the first lens (22) are two-dimensional bulges (27, 29) extending along a first spatial direction (28).

6. sensor system (3) according to claim 5, characterized

in that the radius of curvature of the curvature (27) of the boundary surface (25) of the first lens (22) facing away from the second lens (23) is smaller than the curvature radius of the curvature (29) of that of the second lens (23)

Interface (26) of the first lens (22).

7. Sensor system (3) according to one of the preceding

Claims, characterized in that the second lens (23) has an inwardly curved interface (31) and an as

Free-form surface (32) formed interface (33).

8. Sensor system (3) according to one of the preceding

Claims, characterized in that the first lens (22) facing interface (31) has a two-dimensional

Has a bulge (34) which extends transversely to the bulges (27, 29) of the first lens (22).

9. sensor system (3) according to claim 8, characterized

in that the boundary surface (33) of the second lens (23) remote from the first lens (22) has the free-form surface (32), wherein the free-form surface (32) is formed two-dimensionally.

10. Sensor system (3) according to claim 9, characterized

characterized in that the area change of

Free surface (32) transversely to the bulges (27, 29) of the first lens (22) extends, wherein the surface change of a homogeneous homogeneous brightness distribution to be achieved in the

Detection area (9) of the 3D camera derives.

11. Sensor system (3) according to claim 9 or 10, characterized in that the second lens (23) has substantially the form of the number seven.