DE102017214715A1 - Optical arrangement for a LiDAR system, LiDAR system and working device - Google Patents

Abstract

The present invention relates to an optical arrangement (10) for a LiDAR system (1), comprising (i) receiver optics (30) and transmitter optics (60) which are formed with partially coaxial beam paths (31, 61) (ii ) of a line light source (65-1) with a line orientation (65-2), and (iii) a deflection unit (80) in a transition region from 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 biaxial branching of a light source side region of the beam path (61) transmitter optics (60). The deflection unit (80) has a long mirror (86) with a larger extent (88) in a longitudinal extension direction (88 ') and with a smaller extent (89) in a transverse extension direction (89'), wherein the longitudinal extension direction (88 ') of the Long mirror (86) is aligned perpendicular to the line orientation (65-2) of the line light source (65-1).

Description

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 installations, operating assistance systems or sensor arrangements for detecting the operating environment are increasingly being used. 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 in line illumination to an increased space of the LiDAR system to a reduced Empfangsapertur and / or lead to a reduction in the beam diameter at the beam exit.

Disclosure of the invention

The optical arrangement according to the invention for a LiDAR system with the features of claim 1 has the advantage that in line lighting without space enlargement, a line illumination beam can be emitted without reduction in the receiving aperture at a large beam diameter at the beam exit of the LiDAR system. 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 the line orientation of the underlying line light source.

In the context of the present invention, the deflection unit may be synonymously also referred to as a deflection unit, as a beam splitter unit or as a beam splitter.

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 extent and the transverse extent of the deflection unit are appropriately related to one another and / or to the apertures and the further geometric properties of the transmitter optics and the receiver optics.

In this case, it is provided in particular that the ratio of longitudinal extent to transverse extent on the deflection unit has 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 extent of the deflection unit in relation to the aperture of the beam path of the receiver optics in the range of about 1:14 until 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.

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

In another advantageous embodiment of the optical arrangement according to the invention for a LiDAR system, the transmitter optics and the receiver optics are formed with at least partially or partially coaxial optical 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 deflecting unit forms at least partially or in sections biaxial beam paths on the side of the light source unit of the transmitter optics and on the side of a detector arrangement 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.

list of figures

• 1 ist ein Blockdiagramm, welches schematisch eine Ausführungsform der erfindungsgemäßen optischen Anordnung im Zusammenhang mit einer Ausführungsform eines erfindungsgemäßen LiDAR-Systems zeigt.
• 2 bis 4 zeigen schematische Draufsichten auf Umlenkeinheiten, die bei Ausführungsformen der erfindungsgemäßen optischen Anordnung für ein LiDAR-System verwendet werden können.
• 5 zeigt eine schematische und teilweise geschnittene Seitenansicht einer Ausführungsform der erfindungsgemäßen optischen Anordnung für ein erfindungsgemäß ausgestaltetes LiDAR-System mit einer Umlenkeinheit mit Langspiegel.

Embodiments of the invention will be described in detail with reference to the accompanying drawings.

• 1 Fig. 3 is a block diagram schematically showing an embodiment of the optical arrangement according to the invention in connection with an embodiment of a LiDAR system according to the invention.
• 2 to 4 show schematic top views of deflection units, which can be used in embodiments of the optical arrangement for a LiDAR system according to the invention.
• 5 shows a schematic and partially sectioned side view of an embodiment of the optical arrangement according to the invention for an inventively designed LiDAR system with a deflection unit with long mirror.

Preferred embodiments of the invention

The following are with reference to the 1 to 5 Embodiments and the technical background of the invention described in detail. Identical 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.

1 shows in the form of a schematic block diagram an embodiment of the LiDAR system according to the invention 1 using an embodiment of the optical arrangement according to the invention 10 ,

The LiDAR system 1 according to 1 has a transmitter optics 60 on which of a light source unit 65 , eg with a laser as a line light source 65 - 1 with line orientation 65 - 2 , is fed and primary light 57 generated and this - possibly after passing through a beam shaping optics 66 - in a field of view 50 for capturing and / or examining a scene 53 and an object located there 52 sending out.

Furthermore, the LiDAR system 1 according to 1 a receiver optics 30 on which light and in particular the object 52 in the field of vision 50 reflected light as secondary light 58 via a lens 34 receives as primary optics and via a detector optics 35 as secondary optics to a detector array 20 with detector or sensor elements 22 transfers.

The control of the light source unit 65 as well as the detector arrangement 20 via control lines 42 respectively. 41 by means of a control and evaluation unit 40 ,

The common field of view deflection optics 62 can be considered part of a primary optic 34 the receiver optics 30 be understood and has the inventive design of the optical arrangement 10 with a corresponding deflection unit 80 on that in 1 is shown purely schematically.

Optional and advantageous is the visual field side provision of an aperture optics 70 for properly outputting the primary light 57 and for receiving the secondary light in a focused manner 58 ,

The detector arrangement 20 can with one or more sensor elements 22 be formed, which also according to the line orientation 65-2 the line light source 65-1 can be arranged in the manner of a line detector.

The optical arrangement 10 is trained for a LiDAR system 1 for 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 arrangement 20 and a receiver optics 30 for optically imaging the field of view 50 on the detector array 20 ,

The receiver optics 30 and the transmitter optics 60 are formed on the field of view with substantially coaxial optical axes and have a common deflection optics 62 on.

The receiver optics 30 has detector-side secondary optics 35 which is formed and comprises means via the deflection optics 62 out of sight 50 incident light inherent to the detector array 20 to judge.

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

Further, in the optical arrangement 10 the receiver optics 30 formed and has means for optically imaging the field of view 50 on the detector array 20 ,

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

In the embodiments of the 2 to 4 has the deflection unit 80 one long mirror each 86 on. Each long mirror 86 has a longitudinal extension 88 in a longitudinal direction 88 ' and a transverse extent 89 in a transverse direction of extension 89 ' , The transverse extent 89 is less than the longitudinal extent 88 , A respective longitudinal direction 88 ' is perpendicular to the line orientation 65-2 the underlying line light source 65-1 , The transverse extension directions 89 ' perpendicular to the longitudinal direction 88 ' and parallel to the line orientation 65-2 ,

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

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

The long mirror 86 the embodiment of the deflection 80 according to 4 has a double concave shape or the shape of a double meniscus in plan view. That means the transverse extent 88 at the ends of the long mirror 86 is greater than the transverse extension direction 89 " in a central area of the long mirror 86 ,

5 shows a schematic and partially sectioned side view of an embodiment of the optical arrangement according to the invention 10 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 in the plane of the long mirror 86 as shown schematically in 5 is shown.

The long mirror 86 can according to one of 2 to 4 be designed.

In the embodiment according to 5 the vertical and the axial deflection takes place in relation to the beam path 61 the transmitter optics 60 , whereas the beam path 31 the receiver optics 30 is not deflected, but runs linear.

The entire optical arrangement 10 the LiDAR system according to the invention 1 can be rotatable about a rotation axis by means of a corresponding mechanism. It can have an effective diameter during rotation.

The spatial resolution can be with a LiDAR system 1 be realized by the simultaneous or sequential illumination of a larger area, such as a line, and a reception-side distinction based on an imaging optics and a detector array or a detector row.

Particularly space-saving and low-cost can be constructed coaxial versions 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 around the transmit beam as primary light 57 to reflect in the environment. A signal thrown back from the environment becomes secondary light 58 receive.

For example, a collimated laser beam is used as the primary light 57 emitted. 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. Furthermore, it is desirable to have as much area as possible for the detection of the target or object 52 reflected light 58 to have a sufficiently high signal intensity at large measuring 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 will now be described, as in a coaxial LiDAR system 1 over a long mirror 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 ensuring a large beam diameter at the exit surface of the system.

• - das Ausbilden eines koaxialen LiDAR-Systems 1,
• - das Abbilden einer Linie, indem nämlich ein Strahl als Primärlicht 57 in einer ersten Richtung senkrecht zur Ausbreitungsrichtung kollimiert und in einer zweiten Richtung senkrecht zur Ausbreitungsrichtung und insbesondere auch senkrecht zur ersten Richtung divergent geformt wird,
• - das Führen des Laserstrahls als Primärlicht 57 über einen Langspiegel 86 als Strahlteiler 80,
• - das Fokussieren der divergenten Achse auf den Langspiegel 86 oder in der Nähe des Langspiegels 86, insbesondere auf die oder auf eine schmale Seite des Langspiegels 86,
• - das Kollimieren der nicht divergenten Achse, entsprechend der langen Seite des Langspiegels 86,
• - das Ausbilden der langen Seite des Langspiegels 86 um mindestens einen Faktor 2 im Vergleich zur schmalen Seite des Langspiegels 86 und/oder
• - das Erreichen einer Drehung der Linie im Fernfeld im Vergleich zur Orientierung des Langspiegels 86.

Essential features of the invention are accordingly:

• the formation of a coaxial LiDAR system 1 .
• - The mapping of a line, namely by a beam as a primary light 57 collimated in a first direction perpendicular to the propagation direction and divergent in a second direction perpendicular to the direction of propagation and in particular also perpendicular to the first direction,
• - guiding the laser beam as a primary light 57 over a long mirror 86 as a beam splitter 80 .
• - Focusing the divergent axis on the long mirror 86 or near 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 one factor 2 in comparison to the narrow side of the long mirror 86 and or
• - The achievement of a rotation of the line in the far field compared to the orientation of the long mirror 86 ,

• - Es kann ein koaxiales Lasersystem mit geringen Abmessungen verwendet werden, wobei ein Großteil der Geräteapertur für die Detektion von Signalen eingesetzt werden kann.
• - Der ausgesendete Strahl als Primärlicht 57 besitzt am Ort des Strahlaustrittes bereits einen großen Strahldurchmesser, was für die Augensicherheit wichtig ist.
• - Der kollimierte Strahl besitzt dabei ebenfalls einen großen Strahldurchmesser, wodurch das Aussenden eines Strahls mit geringer Divergenz möglich wird.

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 a primary light 57 already has a large beam diameter at the location of the beam exit, 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 primary light 57 depends on the beam diameter, ie the minimum beam diameter, which is also referred to as beam waist or beam Waist, 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 line-shaped light distribution or illumination results in the manner of a line.

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

Claims (7)

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 from 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 biaxial branching of a light source side region of the beam path (61) of the transmitter optics (60), wherein: - the deflection unit (80) has a long mirror (86) with a larger extension (88) in a longitudinal direction (88 ') and with a smaller Extension (89) in a transverse extension direction (89 ') and - the longitudinal extension direction (88') of the long-mirror (86) is aligned perpendicular to the line orientation (65-2) of the line light source (65-1). An optical assembly (10) according to any one of the preceding claims, wherein the ratio of longitudinal extent (88) to transverse extent (89) on the deflection unit (80) is at least 2: 1, preferably at least 3: 1 and more preferably at least 4: 1. 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) of the receiver optics (30) has a value in the range of about 1:14 to about 1: 7. An optical arrangement (10) according to any one of the preceding claims, wherein the long mirror (86) of the deflection unit (80) in the form of a rectangle, a biconvex elliptical shape, a biconcave shape or a Doppelmeniskusform 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 deflecting unit (80) at least partially or partially 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). 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).

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