EP3394637A1

EP3394637A1 - Lidar scanning device and lidar scanning device system

Info

Publication number: EP3394637A1
Application number: EP16785537.8A
Authority: EP
Inventors: Klaus Stoppel; Frank Kaestner; Hans-Jochen Schwarz; Mustafa Kamil; Joern Ostrinsky; Siegwart Bogatscher
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2015-12-22
Filing date: 2016-10-26
Publication date: 2018-10-31
Also published as: KR20180095659A; US20190004153A1; JP6805254B2; DE102015226460A1; CN108474850A; CN108474850B; WO2017108236A1; US11002834B2; JP2019502921A

Abstract

The invention relates to a Lidar scanning device for use in a motor vehicle, comprising a light source for emitting light on an object; a light detector for receiving light reflected by the object; and a plurality of optical imaging elements in the beam path between the object and the light detector.

Description

description

title

L IDA R-A button and L IDA R-A button sys tem

The invention relates to a lidar scanner. In particular, the invention relates to a lidar scanning device for use on a motor vehicle.

State of the art

A lidar scanner includes a light source and a light detector. The light source emits light within a predetermined observation area and the light detector receives emitted light that has been reflected on an object in the observation area. On the basis of the detected reflected light, for example, an extent and / or a distance of the object can be determined.

For different purposes different observation areas are beneficial. For example, if the motor vehicle is traveling on a motorway, a motor vehicle traveling in front can be detected in an observation area that has a small opening angle and a long range. On the other hand, if the motor vehicle drives slowly, then a close range can be improved with a large opening angle and a small range.

Usually, an optical imaging element is provided in the beam path between the object and the light detector, which determines the observation area. In this case, the optical imaging element is fixed so that a lidar scanner is usually dedicated to a purpose or group of similar uses.

It is an object of the invention to provide an improved lidar scanner and a lidar scanner system. The invention solves this object by means of the subjects of the independent claims. Subclaims give preferred embodiments again.

Disclosure of the invention

A lidar scanner for use in a motor vehicle includes a light source for emitting light to an object; a light detector for receiving light reflected from the object; and a plurality of optical imaging elements in the beam path between the object and the light detector.

By using not just one, but multiple imaging elements, the same lidar scanner can be used for different purposes. For example, different driver assistance systems on board the motor vehicle can access the lidar scanning device.

An optical imaging element may comprise a taper optic, a refractive element or a diffractive element. A taper optic is usually formed from a large number of photoconductive fibers that image light from an entrance surface on an exit surface. The fibers are preferably monomode and may be tightly bundled to effectively form a solid block. A refractive element is based on refraction and may include, for example, a lens or a prism. A diffractive element is based on light diffraction and can work, for example, by means of a microstructure. The invention makes it possible to combine identical or different optical imaging elements.

It is particularly preferred that the optical imaging elements have different observation areas. As a result, the lidar scanning device can serve different purposes in an improved manner.

In one variant, the observation areas differ in an opening angle or a range. In another variant, the observation areas differ in an orientation of their boundaries. In other words, the observation areas can be relative to their opening angle or their range and / or with respect to their direction, with respect to a Orientation of the motor vehicle, different. The variations can be combined with each other so that, for example, a first observation area in the direction of travel is directed forward and has a narrow opening angle, while a second observation area is oriented laterally (lateral) and has a large opening angle. For example, an anti-collision assistant and a parking aid can use the lidar scanner with an associated observation area.

In a preferred embodiment, the imaging elements form on different areas of the light detector. As a result, the observation areas can also be used competitively, ie simultaneously.

In another embodiment, the areas of the light detector on which the imaging elements are located overlap, and preferably a controllable aperture is provided for shading one of the observation areas. In particular, the diaphragm can be controlled to shade all but one of the observation areas. For this purpose, two individually controllable diaphragms or a common diaphragm can be provided. The common diaphragm can, in particular, comprise a simple perforated diaphragm which can be displaced so that its hole lies in that beam path whose assigned observation region is to be utilized. As a result, temporally successive different observation areas can be used, which can each utilize the entire light detector.

In yet another embodiment, an optical bandpass is provided in each of the beam paths of the imaging elements, wherein bandwidths and / or center wavelengths of the bandpasses are different. Preferably, the bandwidth and / or the center wavelength of a bandpass is adapted to an associated observation area. In particular, an adaptation can take place with respect to an opening angle or a range. The smaller the aperture angle, the smaller the bandwidth of the bandpass filter can be, resulting in an improved Signal to Noise Ratio (SNR).

A lidar scanning system includes a light source for emitting light to an object; a light detector for receiving light reflected from the object; and a plurality of optical imaging elements, one of which in the Beam path between the object and the light detector can be arranged.

The optical imaging element may be selected in response to a scheduled use of the lidar scanner detected by the insertion of the

Imaging element arises. It is particularly preferred that several optical imaging elements can be arranged in the beam path at the same time, as described in more detail above. Advantageously, a range and / or an opening angle of a

Observation range of the lidar scanner can be discretely varied by appropriate choice of a matching optical imaging element. In particular, the range can be adjusted discretely within a predetermined opening angle. A sensor housing can be improved adapted to an inserted optical imaging element. An observation area can be extended by adding a further optical imaging element, in particular a taper optic, a refractive element or a diffractive element. A light detector array comprising a plurality of discrete light detectors may be replaced by discrete single detectors. Each individual detector can be assigned an optical imaging element.

The discrete single detectors may be less expensive and / or more robust. The optical imaging elements may be chosen such that the observation areas overlap one another so that a scan may be more robust, for example, to dirt or other disturbances. In addition, a range may be set by overlapping a plurality of observation areas so that redundant sampling is possible in this particular region of interest (ROI). The ASIL capability of the lidar scanner can thereby be increased. Brief description of the figures

The invention will now be described in more detail with reference to the attached figures, in which:

Fig. 1 is a representation of a lidar scanning device for use on a

Motor vehicle; FIG. 2 shows different observation areas of a lidar scanning device according to FIG. 1; FIG. and

FIG. 3 illustrates graphs of different bandpasses for use on the lidar scanner of FIG. 1. FIG.

FIG. 1 shows a representation of a lidar scanning device 100, in particular for use on a motor vehicle. The scanner 100 includes a

Light source 105 and a light detector 1 10, and preferably a plurality of optical imaging elements 1 15. The scanning device 100 is adapted to optically scan an object 120. For this purpose, the light source 105 emits light which can be reflected on the object 120 and thrown onto the light detector 110. In one embodiment, the light source 105 and the

Light detector 1 10 integrated with each other so that they largely share the same beam path. The light source 105 preferably comprises a laser, the light of which can be guided in an embodiment in a cell shape or in rows and columns over a predetermined range. The light detector 110 comprises either a discrete element or a one or two-dimensional array of discrete sensor elements. The optical imaging element 15 is disposed in the beam path between the object 120 and the light detector 110 and is configured to focus or to expand the light passing through it in a predetermined manner. The optical imaging element 15 may in particular comprise a taper optic, a refractile element, a diffractive element or a combination thereof.

An observation area 125, from which light can be incident on the light detector 110 by the imaging element 15, is usually determined mainly by the optical properties of the imaging element 15. In particular, an opening angle 130 or an orientation of a boundary 135 of the opening angle 130 can be defined by the imaging element 15.

It is proposed to provide at least two optical imaging elements 15 simultaneously in the beam path between the object 120 and the light detector 110. As can be seen from the representation of FIG. 1, each the imaging element 1 15 be assigned to an observation area 125, wherein the entire observation area 125 of the lidar scanning device 100 may result from the combination of two observation areas 125. Optionally, an aperture 140 and / or a bandpass 145 are provided in the beam path between the object 120 and the light detector 110. Preferably, each imaging element 15 is assigned its own bandpass 145. It is also possible to use associated diaphragms 140 or a common diaphragm for both imaging elements 15. In one embodiment, the bezel 140 includes a simple pinhole that is configured to

Beam path between only one of the optical imaging elements 1 15 and the light detector to allow 1 10 and shade the other beam path. In yet another embodiment, one or more irises, along with the pinhole, may represent the aperture 140.

Preferably, the observation areas 125 differ with regard to their orientation, their opening angle 130 and / or their range. In this case, the observation areas 125 may overlap or be disjunctive. The orientation of an observation area may be given by an angle of bisector of the opening angle 130 which extends between boundaries 135. In various embodiments, the observation areas 125 may be different or overlapping one another. In further embodiments, the observation areas 125 may also be identical to one another or one of the observation areas 125 may be part of the other observation area 125.

Each optical imaging element 1 15 is configured to image light onto a predetermined, associated detection area 150 of the light detector 110. Irrespective of the relative position of the observation regions 125, the detection regions 150 may overlap one another, be identical to one another, be disjoint, or one detection region 150 may form part of the other detection region 150. In one embodiment, both detection areas 150 lie on the same light detector 110, in another embodiment two discrete light detectors 110 are provided, each of which has its own detection area 150. Due to the various possibilities of matching the observation areas 125 and the detection areas 150, a large number of different embodiments with otherwise identical components can be brought about by selecting respectively suitable optical imaging elements 15.

A lidar scanner system 160 includes a plurality of optical imaging elements 15, of which at least one, but preferably at least two, are used to form the lidar scanner 100 described above. With the aid of the system 160, a lidar scanning device 100 can be constructed in the manner of a construction kit, which can be specifically adapted to several different purposes. In a further embodiment, three or more optical imaging elements 15 are provided in the lidar scanner 100, the above explanations applying mutatis mutandis.

FIG. 2 shows different exemplary observation regions 125 of a lidar scanning device 100 according to FIG. 1. A top view shows a top view and a bottom view a side view of the observation regions 125.

A first observation area 125.1, which is assigned to a first optical imaging element 15.1, has a small first opening angle 130.1. The range is relatively large and the first observation area 125.1 is oriented horizontally and vertically symmetrically to a direction of travel 205.

A second observation area 125.2 is assigned to a second optical imaging element 15.2. A second opening angle 130.2 is smaller than the first opening angle 130.1 and the orientation of the second observation area 125.2 includes an angle with the direction of travel 205 in the horizontal direction, while the second observation area 125.2 runs in the vertical direction parallel to the direction of travel 205.

A third observation area 125.3 is assigned to a third optical imaging element 15.3. An associated third opening angle 130.3 is greater than the second opening angle 130.2 and a horizontal orientation of the third

Observation area 125.3 includes a larger angle in the horizontal direction with the direction of travel 205 than the second observation area 125.2. In the vertical direction, the third observation area 125.3 is aligned parallel to the direction of travel 205.

The imaging elements 1 15.1, 1 15.2 and 1 15.3 can be used simultaneously or successively to scan the observation areas 125.1, 125.2 or 125.3. Preferably, all imaging elements 15 are each part of the same lidar scanning device 100, so that 100 different scans can be made by means of the same scanning device.

FIG. 3 shows diagrams of different bandpasses 145 for use on the lidar scanner 100 of FIG. A first diagram 305 is shown in the upper area and a second diagram 310 in the lower area. The first diagram 305 is associated with a first bandpass 145 associated with a first observation region 125, and the second diagram 310 is associated with a second bandpass 145 associated with a second observation region 125 (see Figure 1). The bandpass 145 may be embodied integrated in one embodiment with the respective associated optical imaging elements 1 15.

In both diagrams 305, 310 in the horizontal direction, a wavelength and in the vertical direction, a transmission, so a permeability of the respective bandpass 145 indicated.

In each diagram 305, 310, a first transmission curve 315 is entered by a solid line, and a second transmission curve 320 is shown by a broken line and an envelope curve 325 in each case. It is assumed that the bandpass 145 of the first diagram 305 is associated with an observation area 125 with a small opening angle 130 and the second diagram 310 is associated with an observation area 125 with a larger opening angle 130. The first transmission curve 315 respectively indicates the light passing through the band-pass 145 when it is incident from the direction of the bisector of the opening angle 130. The second transmission curve 320 analogously designates the light passing through the bandpass 145 from a direction near one of the boundaries 135. The envelope 325 denotes the respective passband of the two bandpasses 145. It can be seen that in the first diagram 305, a narrower envelope 325 than can be used in the second diagram 310. In other words, the envelope 325 of the bandpass 145 can be selected as a function of the opening angle 130 of the respective associated observation area 125. Thus, the bandwidth which corresponds in the representation of the width of the envelope 125 at half height (half width = filling width at maximum half, FWHM), adjusted adapted to be narrow. As a result, an improved protection against stray light, which may for example result from the sun or another light source, can be achieved.

Claims

claims

1 . A lidar scanner (100) for use in a motor vehicle, the lidar scanner (100) comprising:

- A light source (105) for emitting light to an object (120);

- A light detector (1 10) for receiving light, which has been reflected by the object (120);

- Several optical imaging elements (1 15) in the beam path between the object (120) and the light detector (1 10).

2. Lidar scanning device (100) according to claim 1, wherein an optical imaging element (1 15) comprises a taper optic, a refractive element or a diffractive element.

3. Lidar scanning device (100) according to claim 1 or 2, wherein the optical imaging elements (1 15) have different observation areas (125).

4. lidar scanner (100) according to claim 3, wherein the observation areas (125) in an opening angle (130) or a range differ.

The lidar scanner (100) of claim 3 or 4, wherein the viewing areas (125) differ in an orientation of their boundaries (135).

6. Lidar scanning device (100) according to any one of the preceding claims, wherein the imaging elements (1 15) to different areas (150) of the light detector (1 10).

The lidar scanner (100) of any one of claims 1 to 5, wherein portions (150) of the light detector (110) to which the imaging elements (1 15), overlap, and a controllable diaphragm (140) for shading one of the observation areas (125) is provided.

8. Lidar scanning device (100) according to any one of the preceding claims, wherein in the beam paths of the imaging elements (1 15) in each case an optical bandpass filter (145) is provided and bandwidths and / or center wavelengths of the bandpass filters (145) are different.

A lidar scanner system (100) for use in a motor vehicle, the lidar scanner system (100) comprising:

- A light source (105) for emitting light to an object (120);

- A light detector (1 10) for receiving light, which has been reflected by the object (120); and

- Several optical imaging elements (1 15), one of which in the beam path between the object (120) and the light detector (1 10) can be arranged.

10. Lidar scanner system (100) according to claim 9, wherein a plurality of optical imaging elements (1 15) can be arranged in the beam path at the same time.