WO2019038063A1

WO2019038063A1 - Optical assembly for a lidar system, lidar system, and working device

Info

Publication number: WO2019038063A1
Application number: PCT/EP2018/071125
Authority: WO
Inventors: Annemarie Holleczek; Tobias PETERSEIM; Stefan Spiessberger
Original assignee: Robert Bosch Gmbh
Priority date: 2017-08-23
Filing date: 2018-08-03
Publication date: 2019-02-28
Also published as: DE102017214715A1

Abstract

The present invention relates to an optical assembly (10) for a LIDAR system (1), having (i) receiver optics (30) and transmitter optics (60) which are designed with partially coaxial beam paths (31, 61), (ii) a linear light source (65-1) having a linear orientation (65-2), and (iii) a deflection unit (80) in a transition region from a joint, coaxial region to a separate, biaxial region of the beam paths (31, 61) of the receiver optics (30) and of the transmitter optics (60) for biaxial branching of a region on the light source side of the beam path (61) of the transmitter optics (60). The deflection unit (80) has a long mirror (86) having a greater extent (88) in a longitudinal direction (88') and having a lesser extent (89) in a transverse direction (89'), wherein the longitudinal direction (88') of the long mirror (86) is oriented perpendicularly to the linear orientation (65-2) of the linear light source (65-1).

Description

description

title

Optical arrangement for a LiDAR system, LiDAR systems and

working device

State of the art

The present invention relates to an optical arrangement for a LiDAR system, a LiDAR system as such, and a working device, and more particularly to a vehicle.

With the use of working devices, of vehicles and other machines and plants are increasingly operating assistance systems or

Sensor arrays used to detect the operating environment. In addition to radar-based systems or systems based on ultrasound, light-based detection systems are also increasingly used, e.g. so-called LiDAR systems (English: LiDAR: light detection and ranging).

In known LiDAR systems and their optical arrangements, there is a disadvantage in that coaxial beam paths of the transmitter optics and the receiver optics on the beam output side or the beam input side conventionally beam splitters are used, which reduced in line illumination to an increased space of the LiDAR system to a reduced

Reception aperture and / or lead to a reduction in the beam diameter at the beam exit.

Disclosure of the invention

In contrast, the optical arrangement according to the invention for a LiDAR system with the features of claim 1 has the advantage that with line illumination without increased installation space, a line illumination beam without reduction in the receiving aperture with a large beam diameter at Beam exit of the LiDAR system can be emitted. This is inventively achieved with the features of claim 1, characterized in that an optical arrangement for a LiDAR system is provided which is formed (i) with a receiver optics and transmitter optics, which partially coaxial beam paths, (ii) with a line light source with a line orientation, wherein the line orientation is formed in particular in a field of view of the underlying LiDAR system, and (iii) with a deflection unit as a beam splitter unit in a transition region of a common coaxial region - in particular on a beam exit side of the transmitter optics or on a beam entrance side Receiver optics - to a separate biaxial region of the beam paths of the receiver optics and the transmitter optics - in particular on a detector side or on a source side - for biaxial branching of a light source side region of the beam path of the transmitter optics.

According to the invention, the deflection unit has a long mirror, which is formed with a larger extent in a longitudinal direction and with a smaller extent in a transverse direction of extension and in particular for deflecting primary light from the line light source. Furthermore, the longitudinal extension direction of the long mirror is aligned perpendicular to

Line orientation of the underlying line light source.

In connection with the present invention, the deflection unit can also be used synonymously as a deflection unit, as a beam splitter unit or as

Beam splitter can be called.

In connection with the present invention, the so-called laser line is preferably formed at some distance from the light source unit and after passing through the area with the deflection unit in the desired quality, namely with the line orientation predetermined by the light source unit and further converted by the deflection unit.

The dependent claims show preferred developments of the invention.

In a preferred embodiment of the optical arrangement according to the invention for a LiDAR system, the longitudinal extension and the

Transverse extent of the deflection in a suitable relationship set to each other and / or to the apertures and the other geometric

Properties of the transmitter optics and the receiver optics.

It is provided in particular that the ratio of

Longitudinal extent to transverse extent at the deflection unit at least the value 2: 1, preferably at least the value 3: 1 and more preferably at least the value 4: 1.

In another additional or alternative embodiment of the optical arrangement according to the invention for a LiDAR system, have a diameter of the aperture of the beam path of the transmitter optics or the

Longitudinal extension of the deflection unit in relation to the aperture of the

Beam path of the receiver optics in the range of about 1: 14 to about 1: 7.

In the embodiment of the deflection unit and in the choice of the corresponding geometry of the long mirror, various and adapted to the particular application and the geometries of receiver optics and transmitter optics geometric configurations offer.

Thus, it is provided according to a preferred embodiment of the optical arrangement according to the invention for a LiDAR system that the long mirror of the deflection in the form of a rectangle, a biconvex elliptical shape, a biconcave shape or a plan view of the deflection

Has double meniscus shape.

In another advantageous embodiment of the optical arrangement according to the invention for a LiDAR system, the transmitter optics and the

Receiver optics formed with at least partially or partially mutually coaxial beam paths on the beam exit side of the transmitter optics and / or beam entrance side of the receiver optics.

It is particularly advantageous if the deflection at least partially or partially biaxial beam paths on the side of the

Light source unit forms the transmitter optics and on the side of a detector array of the receiver optics. Furthermore, the present invention relates to a LiDAR system for optically detecting a field of view, in particular for a working device and / or a vehicle. The LiDAR system is formed with an optical arrangement according to the invention.

Furthermore, the present invention relates to a working device and in particular a vehicle, which are formed with a LiDAR system according to the invention and for the optical detection of a field of view. Brief description of the figures

Embodiments of the invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a block diagram schematically showing a

Embodiment of the optical arrangement according to the invention in connection with an embodiment of a LiDAR system according to the invention shows. Figures 2 to 4 are schematic plan views of diverter units which may be used in embodiments of the optical arrangement for a LiDAR system according to the present invention. Figure 5 shows a schematic and partially sectioned

Side view of an embodiment of the optical arrangement according to the invention for a designed according to the invention LiDAR system with a deflection unit with long mirror.

Preferred embodiments of the invention

Hereinafter, with reference to FIGS. 1 to 5

Embodiments and the technical background of the invention described in detail. Equal and equivalent as well as equivalent or equivalent

Elements and components are designated by the same reference numerals. Not in every case of their occurrence, the detailed description of the designated elements and components is reproduced.

The illustrated features and other properties can be isolated in any form from each other and combined with each other, without departing from the gist of the invention.

Figure 1 shows in the form of a schematic block diagram a

Embodiment of the LiDAR system 1 according to the invention using an embodiment of the optical arrangement 10 according to the invention.

The LiDAR system 1 according to FIG. 1 has a transmitter optics 60, which are provided by a light source unit 65, e.g. with a laser as a line light source 65-1 with line orientation 65-2, and primary light 57 is generated and this - possibly after passing through a beam shaping optics 66 - in a field of view 50 for detecting and / or investigation of a scene 53 and an object 52 there sending out.

Furthermore, the LiDAR system 1 according to FIG. 1 has a receiver optics 30, which receive light and, in particular, reflected light from the object 52 in the field of view 50 as a secondary light 58 via a lens 34 as a primary optic and with a detector optics 35 as secondary optics to a detector arrangement 20 Detector or sensor elements 22 transmits.

The control of the light source unit 65 and the detector arrangement 20 via control lines 42 and 41 by means of a control and evaluation unit 40th

The common field of view deflection optics 62 can be considered as part of a primary optics 34 of the receiver optics 30 and has the inventive design of the optical assembly 10 with a corresponding

Deflection unit 80, which is shown purely schematically in Figure 1.

Optionally and advantageously, the visual field-side provision of an aperture optics 70 for suitably outputting the primary light 57 and for receiving the secondary light 58 in bundling fashion. The detector arrangement 20 may be formed with one or more sensor elements 22, which may also be arranged according to the line orientation 65-2 of the line light source 65-1 in the manner of a line detector.

The optical arrangement 10 is designed for a LiDAR system 1 for the optical detection of a field of view 50, in particular for a working device, a vehicle or the like, and is formed with a transmitter optics 60 for emitting a transmission light signal in the field of view 50, a detector array 20 and a Receiver optics 30 for optically imaging the field of view 50 on the detector assembly 20th

The receiver optics 30 and the transmitter optics 60 are visible in the field of view

Substantially coaxial optical axes formed and have a common deflection optics 62.

The receiver optics 30 has a secondary optics 35 on the detector side, which is embodied and comprises means for directing light incident on the deflector 62 from the field of view 50 to the detector arrangement 20 in an inherent manner.

In the optical arrangement 10, the transmitter optics 60 is generally formed and has means for emitting primary light 57 into the field of view 50.

Furthermore, in the optical arrangement 10, the receiver optics 30 are formed and have means for optically imaging the field of view 50 on the

Detector assembly 20.

FIGS. 2 to 4 show schematic plan views of deflection units 80 which can be used in embodiments of the optical arrangement 10 according to the invention for a LiDAR system 1.

In the embodiments of FIGS. 2 to 4, the deflection unit 80 has a long mirror 86 in each case. Each long mirror 86 has a

Longitudinal extension 88 in a longitudinal direction 88 'and a

Transverse extension 89 in a transverse extension direction 89 '. The transverse extent 89 is less than the longitudinal extent 88. A respective

Longitudinal direction 88 'is formed perpendicular to the line orientation 65-2 of the underlying line light source 65-1. The Transverse transverse directions 89 'formed perpendicular to

Longitudinal direction 88 'and parallel to the line orientation 65-2.

The long mirror 86 of the embodiment of the deflection unit 80 according to FIG. 2 has the shape of a rectangle. The long edge of the rectangle is aligned parallel to the longitudinal extension direction 88 '. The short edge of the rectangle is aligned parallel to the transverse extension direction 89 '.

The long mirror 86 of the embodiment of the deflection unit 80 according to FIG. 3 has the shape of an ellipse with the orientation of the large semiaxis parallel to the longitudinal extension direction 88 '. The small semi-axis of the ellipse is aligned parallel to the transverse extension direction 89 '.

The long mirror 86 of the embodiment of the deflection unit 80 according to FIG. 4 has in plan view a double concave shape or the shape of a

Double meniscus on. This means that the transverse extent 88 at the ends of the long mirror 86 is greater than the transverse extension direction 89 "in a central region of the long mirror 86. FIG. 5 shows a schematic and partially sectioned side view of FIG

Embodiment of the optical arrangement 10 according to the invention for a designed according to the invention LiDAR system 1 with a deflection unit 80 with long mirror 86. Preferably, the focus of the beam of the primary light 57 lies in the plane of the long mirror 86, as shown schematically in Figure 5.

The long mirror 86 may be configured according to one of FIGS. 2 to 4.

In the embodiment according to FIG. 5, the vertical and the axial deflection take place in relation to the beam path 61 of the transmitter optics 60, whereas the

Beam path 31 of the receiver optics 30 is not deflected, but runs linear.

The entire optical arrangement 10 of the LiDAR system 1 according to the invention can be rotatable about an axis of rotation by means of a corresponding mechanism. It can have an effective diameter during rotation. The spatial resolution can be realized in a LiDAR system 1 by the simultaneous or sequential illumination of a larger area, for example a line, and a reception-side differentiation on the basis of an imaging optics and a detector array or a detector row.

Particularly space-saving and low-cost can be constructed coaxial embodiments with each other at the output and input side, in which the output-side transmission path 61 and the input side

Receive path 31 partially coincide.

The long mirror 86 is used to reflect the transmission beam as primary light 57 into the environment. A signal thrown back from the environment is received in the sense of secondary light 58.

For this purpose, for example, a collimated laser beam is emitted as the primary light 57. In general, it is favorable to emit a large beam diameter, since this is advantageous for eye safety reasons and, moreover, enables lower beam divergences for a given beam quality. Of

Furthermore, it is desirable to have as much area as possible for the detection of the light 58 reflected at the target or object 52 in order to obtain a sufficiently high signal intensity at large measurement distances.

This combination of these two requirements is a contradiction in conventional arrangements for LiDAR systems because the emission of a larger beam reduces the receive aperture.

According to the invention, a procedure is now described how, in the case of a coaxial LiDAR system 1, as a beam splitter 80, a line illumination beam (flash line or line flash) can be emitted without significantly reducing the receiving aperture and at the same time a large beam diameter at the exit surface of the To ensure system.

Accordingly, essential features of the invention are: the formation of a coaxial LiDAR system 1, the imaging of a line, namely by collimating a beam as a primary light 57 in a first direction perpendicular to the propagation direction and diverging it in a second direction perpendicular to the propagation direction and in particular also perpendicular to the first direction,

guiding the laser beam as a primary light 57 via a long mirror 86 as a beam splitter 80,

focusing the divergent axis on the long mirror 86 or in the vicinity of the long mirror 86, in particular on or on a narrow side of the long mirror 86,

collimating the non-divergent axis, corresponding to the long side of the long-mirror 86,

forming the long side of the long mirror 86 by at least a factor of 2 compared to the narrow side of the long mirror 86 and / or

- Achieving a rotation of the line in the far field compared to

Orientation of the long-mirror 86.

The advantages include:

- It can be used a coaxial laser system with small dimensions, with a large part of the device aperture can be used for the detection of signals.

- The emitted beam as the primary light 57 has at the location of the beam exit already a large beam diameter, which is important for eye safety.

The collimated beam also has a large beam diameter, which makes it possible to emit a beam with little divergence.

Particularly advantageous is a collimation of the beam of the primary light 57. The divergence of the beam of the primary light 57 depends on the

Beam diameter, so the minimum beam diameter, softer than Beam waist or beam Waist is called, and the beam quality of the beam 57 from.

The larger the beam diameter, the lower the divergence.

As a rule, very low divergences are sought, whereby a large beam diameter in this spatial direction is advantageous. In the other spatial direction, the beam should have a relatively large divergence, so that after a certain distance from the LiDAR system a linear

Distribution of light or illumination in the manner of a line.

In a preferred variant of the LiDAR system 1 according to the invention, there is no further optics between deflecting mirror as beam splitter 80 and the exit surface from the system 1, which changes the beam significantly.

Claims

claims

1 . Optical arrangement (10) for a LiDAR system (1), comprising:

a receiver optics (30) and a transmitter optics (60) which are formed with partially coaxial beam paths (31, 61),

a line light source (65-1) with a line orientation (65-2) and

- A deflection unit (80) in a transition region of a

common coaxial region to a separate biaxial region of the beam paths (31, 61) of the receiver optics (30) and the

Transmitter optics (60) for biaxially branching a light source side region of the beam path (61) of the transmitter optics (60),

in which:

- The deflection unit (80) has a long mirror (86) with a larger

Has extension (88) in a longitudinal direction of extension (88 ') and with a smaller extension (89) in a transverse direction of extension (89') and

- The longitudinal direction (88 ') of the long-mirror (86) is aligned perpendicular to the line orientation (65-2) of the line light source (65-1).

2. Optical arrangement (10) according to one of the preceding claims, wherein the ratio of longitudinal extent (88) to transverse extent (89) on the deflection unit (80) at least 2: 1, preferably at least 3: 1 and more preferably at least 4: 1 is.

3. Optical arrangement (10) according to one of the preceding claims, wherein a diameter of the aperture of the beam path (61) of the transmitter optics (60) or the longitudinal extent (88) on the deflection unit (80) in relation to the aperture of the beam path (31) the receiver optics (30) has a value in the range of about 1: 14 to about 1: 7.

4. Optical arrangement (10) according to one of the preceding claims, in which the long mirror (86) of the deflection unit (80) in the form of a rectangle, a biconvex elliptical shape, a biconcave shape or a double meniscus form in plan view of the deflection unit (80).

An optical assembly (10) according to any one of the preceding claims, wherein

- The transmitter optics (60) and the receiver optics (30) with at least partially or partially mutually coaxial beam paths (31, 61) on the beam exit side of the transmitter optics (60) and / or beam entrance side of the receiver optics (30) are formed and

- The deflection unit (80) at least partially or in sections

Biaxial beam paths (31, 61) on the side of the light source unit (65) of the transmitter optics (60) and on the side of a detector arrangement (20) of the receiver optics (30).

6. LiDAR system (1) for the optical detection of a field of view (50),

in particular for a working device and / or a vehicle, with an optical arrangement (10) according to one of claims 1 to 5.

Working device and in particular a vehicle,

with a LiDAR system (1) according to claim 6 for the optical detection of a field of view (50).