DE102017212926A1 - LIDAR device and method with an improved deflection device - Google Patents

Abstract

Disclosed is a LIDAR device for scanning a scanning region with a statically arranged laser for generating at least one beam, with a deflection device rotatable along a rotation axis for deflecting the at least one generated beam into the scanning region and with a receiving optics for receiving and deflecting the at least one reflected beam on an object to a detector, wherein the deflection device comprises an optical waveguide with at least two parallel glass fibers and wherein the at least two parallel glass fibers are arranged offset to one another at an exit side of the optical waveguide. Furthermore, a method for operating a LIDAR device is disclosed.

Description

The invention relates to a LIDAR device for scanning a scanning region and a method for operating such a LIDAR device.

State of the art

In LIDAR (light detection and ranging) devices, in particular, a distance between the LIDAR device and an object is determined. For this purpose, a beam is generated by a laser and emitted into a scanning region. By means of a deflection device, the beam can be deflected distributed over the scanning area. The reflected beam on an object can then be received by a receiving optical system and directed to a detector. For this purpose, different concepts are pursued. In addition to the so-called "Microscanners" also "Macroscanner" are used. Rotating macroscanners may be constructed such that the laser and the detector are statically arranged. The deflection device consists here of a pivotable mirror which deflects the generated beam into the scanning region. In this case, the deflection unit also directs the rays reflected by an object onto the detector. As a result, no energy and data transmission to the rotating parts is needed. From the DE 10 2011 107 594 Such a LIDAR device is known, which uses a rotating mirror for deflecting the generated beams. In these concepts, however, the horizontal field of view, so-called "Field of View" is limited, so that a coverage of 360 ° can only be realized by multiple optical elements, resulting in a complex structure and adjustment. In addition, the resolution in the vertical direction is limited by the number of discrete lasers.

Disclosure of the invention

The object underlying the invention can be seen to suggest a LIDAR device and a method for scanning as large a scanning as possible with reduced complexity.

This object is achieved by means of the subject matter of the independent claims. Advantageous embodiments of the invention are the subject of each dependent subclaims.

According to one aspect of the invention, a LIDAR device for scanning a scan area is proposed. The LIDAR device comprises a statically arranged laser for producing at least one steel, a deflection device rotatable along a rotation axis for deflecting the at least one generated beam into the scanning region, and receiving optics for receiving and deflecting the at least one beam reflected at an object onto a detector on. According to the invention, the deflection device has an optical waveguide with at least two parallel glass fibers, wherein the at least two parallel glass fibers are arranged offset from one another at an exit side of the optical waveguide.

By using an optical waveguide as a deflector or as part of the deflector in the transmit path of the generated beam, the complexity of a LIDAR device can be reduced. The optical waveguide here consists of at least two glass fibers that can guide or deflect the beam generated. The at least two glass fibers may have a sheath and be arranged next to one another or bundled. The glass fibers may for example consist of a plastic or a glass and alternatively have no sheath. The respective glass fibers may be uncoated or at least partially coated. An optical waveguide may comprise one or more glass fibers which form a common core or a plurality of separate cores of the optical waveguide. The respective cores or glass fibers can be arranged constant over a length of the optical waveguide or have a variable arrangement along the length of the optical waveguide. For example, the glass fibers may be arranged side by side at one entrance side and be spaced apart on an exit side of the optical waveguide and form a so-called "bi-furcated fiber" or "multi-furcated fiber". Preferably, the respective optical fibers of the optical waveguide can carry light in any form loss. On a side facing the laser, the optical waveguide has an entry side. Here, the generated beam can be coupled into the optical waveguide. Coupling means here that the generated beam transmits as completely as possible into the glass fibers of the optical waveguide. Preferably, the generated beam is simultaneously coupled into the at least two glass fibers of the optical waveguide. By coupling, the at least one beam is divided into at least two partial beams, which can be guided in each case by a glass fiber. The optical waveguide can for example be bent at a 90 ° angle and be positioned in a rotating housing or in the rotatable deflection device. Thus, the generated beam split into at least two sub-beams may be directed to one side toward the scanning area. On the exit side of the optical waveguide, the partial beams leading glass fibers are arranged vertically one above the other, so that the at least two partial beams can vertically decouple from each other from the optical waveguide. By decoupling from the optical fiber leaves the generated beam the optical fibers of the optical fiber according to the orientation of the glass fibers. In this way, depending on the number of partial beams or glass fibers, a larger vertical range can be scanned or a vertical resolution can be increased. On the exit side of the optical waveguide, the individual glass fibers may be at an angle to each other or spaced from each other. As a result, a vertical resolution or a vertical scanning angle can be set. Alternatively or additionally, the optical waveguide may for example be a so-called "multi-branch-fiber" or a "multi-furcated fiber". In this way, a multiplicity of glass fibers can be arranged one above the other or offset relative to one another on the exit side of the optical waveguide. Alternatively or additionally, the glass fibers can also be arranged horizontally or diagonally next to one another on the exit side, so that a horizontal scanning region can be scanned faster in addition to a larger vertical scanning region. Alternatively or additionally, by bending a region of the optical waveguide instead of rotating the entire optical waveguide, the optical waveguide can deflect the at least one generated beam along the scanning region.

According to an embodiment of the LIDAR device, the entrance side of the optical waveguide forms the axis of rotation. The laser generates a beam that passes through the axis of rotation. As a result, the structure of the LIDAR device can be simplified and downsized. The generated beam or laser beam as well as the inlet side of the optical waveguide in the axis of rotation, so that the generated beam can be coupled without further technical aids in the optical waveguide. Alternatively, optics or a lens can be used for coupling the generated beam into the optical waveguide. Thus, the beam can be coupled independently of a direction of rotation and speed in the optical waveguide.

According to a further embodiment of the LIDAR device, the glass fibers are arranged bundled on the inlet side of the optical waveguide. Thus, a laser can be positioned stationary or not rotatable and couple the at least one generated beam an objective or directly into the optical waveguide. Due to the bundled arrangement of the glass fibers on the inlet side of the optical waveguide, the at least one generated beam can be coupled into all optical fibers simultaneously. In addition, in this case a cross-section of the respective glass fibers on the inlet side of the optical waveguide can be reduced or enlarged. Preferably, the glass fibers are arranged rotationally symmetrical bundled on the inlet side. As a result, the at least one beam can be coupled into a rotating optical waveguide at any time. The cross section can in this case be varied both by a distributed or bundled arrangement of the respective glass fibers and by a cross section of the respective glass fibers.

According to a further embodiment, the glass fibers each have their own transmitting optics on the exit side of the optical waveguide. The individual or selected glass fibers can be printed or equipped with a micro-objective directly on a fiber facet. As a result, for example, an image in a far field as a point or line can be made possible. These lenses printed on the fiber facet can replace a transmission optics. A printing of such an objective can be realized, for example, by 2-photon lithography.

According to a further embodiment, the glass fibers on the outlet side of the optical waveguide on a common transmission optics. As a result, a LIDAR device can be of a particularly simple design, since only one common transmission optics is required. As a result, fewer components are necessary, such a LIDAR device can be designed to save space.

According to a further embodiment of the LIDAR device, the deflection device is rotatable along a 360 ° angle. By rotating the deflection device through 360 °, light or the at least one generated beam can be emitted in all directions, so that a horizontal scanning range of 360 ° is made possible. The vertical scanning area or field of view can be defined by the number of optical fibers, their orientation or spacing from one another and in conjunction with the transmitting optics and the detector resolution.

According to a further embodiment, the vertically stacked glass fibers on the exit side of the optical waveguide form a linear laser beam. Preferably, the individual beams decoupled from the optical waveguide into the scanning area can be combined by suitable transmitting optics into a vertically aligned line, so that a divergence of the line defines the vertical scanning angle or field of view. The line can be realized either by expanding at least one beam using optical elements such as cylindrical lenses or by positioning a plurality of optical fibers on top of each other. As a result, a high vertical resolution of the scanning area can be realized on the detector.

According to another embodiment of the LIDAR device, the detector is annular executed and statically arranged around the laser. Here, the detector is arranged in a ring around the laser and optically isolated. Rays reflected or scattered by an object are collected by a receiving optic mounted in the rotating deflector and deflected by a mirror also disposed in the deflector onto the annular detector. The rays thus received are imaged linearly on the detector at a rotational speed of the deflection device. Based on the movement of the deflection device, an active area on the detector can also be controlled in a variable manner without having to move the detector itself. Alternatively, an integration of the optical waveguide in the receiving optics is possible, whereby, although a vertically aligned "blind spot" arises in the detection, but which can be compensated by a rotation of the deflection device. Such integration allows for a nearly coaxial design of the LIDAR device, thereby reducing the overall height of the LIDAR device and minimizing optical parallax errors. The deflection device can thus serve both to guide and deflect at least one generated beam and to receive and deflect at least one reflected beam.

According to a further embodiment, the detector is arranged statically next to the laser or on a side of the device opposite the laser. For example, the detector may be implemented as a 2D array.

For this purpose, the detector may be arranged parallel to the laser. Reflected beams can be directed onto the detector along a limited scanning range via a receiving optical system which has a mirror and is arranged on the rotatable deflection apparatus. Alternatively, the detector may be disposed in the axis of rotation and positioned on a side of the LIDAR device opposite the laser. Thereby, the reflected beams can be received and detected unrestrictedly along a horizontal 360 ° scanning range.

According to a further embodiment, the detector is arranged in the deflection device. As an alternative to a stationary embodiment of a detector, the detector can be rotatably arranged or integrated in the deflection device. In this case, the detector can be constructed technically simpler, since a line detector is already sufficient. The received beams are imaged on the line detector, so that an optimal use of the available detection pixels can be ensured.

According to another aspect of the invention, a method of operating a LIDAR device is provided. In this case, at least one beam is generated by a laser and coupled into a deflection device. The at least one beam is deflected by the deflection device and emitted along a scanning angle. For this purpose, the at least one generated beam is coupled into a deflected device arranged in the optical waveguide with at least two glass fibers for deflecting. At an exit side of the optical waveguide, the at least one generated beam can be coupled out of the at least two glass fibers as at least two offset partial beams.

In this case, the deflection device has an optical waveguide with at least two glass fibers. The beams can be coupled into the respective glass fibers, which can form a common core or separate cores of the optical waveguide. The glass fibers guide the coupled beams over a defined angular range and thus deflect at least one generated beam. At an exit side of the optical waveguide, the at least one coupled beam can leave the optical waveguide. The optical waveguide is also rotatable as part of the deflection device and can thus deflect the at least one generated beam along a scanning region. Preferably, an entry region of the optical waveguide is positioned in an axis of rotation of the deflection device. The laser is in this case arranged such that a generated beam also extends through the axis of rotation and can be coupled into the optical waveguide. In this case, the optical waveguide with the at least two glass fibers as one or more cores of the optical waveguide fulfills the function of a beam splitter which can receive, guide and divide at least one generated beam. At the exit side of the optical waveguide, the respective glass fibers can be spaced apart from each other and / or arranged angularly offset from one another. As a result, multiple partial beams are generated, which can be used for vertical or horizontal scanning of the scanning. Thus, a vertical resolution of a LIDAR device can be increased or a larger vertical range can be scanned without additional control effort.

• 1a eine schematische Darstellung eines Lichtwellenleiters einer Ablenkvorrichtung gemäß einem ersten Ausführungsbeispiel,
• 1b eine schematische Darstellung des Lichtwellenleiters einer Ablenkvorrichtung gemäß einem zweiten Ausführungsbeispiel,
• 2 eine schematische Darstellung einer Sendeoptik des Lichtwellenleiters einer Ablenkvorrichtung gemäß einem dritten Ausführungsbeispiel,
• 3 eine schematische Darstellung einer LIDAR-Vorrichtung gemäß einem ersten Ausführungsbeispiel,
• 4 eine schematische Darstellung einer LIDAR-Vorrichtung gemäß einem zweiten Ausführungsbeispiel und
• 5 eine schematische Darstellung einer LIDAR-Vorrichtung gemäß einem dritten Ausführungsbeispiel.

In the following, preferred exemplary embodiments of the invention are explained in greater detail on the basis of greatly simplified schematic representations. Show here

• 1a a schematic representation of an optical waveguide of a deflection apparatus according to a first embodiment,
• 1b a schematic representation of the optical waveguide of a deflection apparatus according to a second embodiment,
• 2 a schematic representation of a transmitting optical system of the optical waveguide of a deflection apparatus according to a third embodiment,
• 3 a schematic representation of a LIDAR device according to a first embodiment,
• 4 a schematic representation of a LIDAR device according to a second embodiment and
• 5 a schematic representation of a LIDAR device according to a third embodiment.

In the figures, the same constructive elements each have the same reference numerals.

The 1a and 1b each show optical fibers 1 , The optical fibers 1 are in an in 3 arranged and numbered deflection arranged. The optical fibers 1 have an entry side 2 for coupling in beams and an exit side 4 for decoupling of rays. According to a first embodiment, the optical waveguide 1 two glass fibers 6 and is a so-called "bifurcated fiber". The glass fibers 6 each form here a core of the optical waveguide 1 , On the entrance side 2 are the glass fibers 6 bundled arranged. On the exit side 4 are the glass fibers 6 spaced apart and have an angle to each other. Thus, one in the optical fiber 1 coupled beam through the two glass fibers 6 be divided into two sub-beams and fanned out at a decoupling. In contrast to the first embodiment, the optical waveguide 1 According to the second embodiment, a plurality of glass fibers 6 on. Here is the optical fiber 1 executed in the form of a so-called "multi-branch fiber".

In the 2 is a glass fiber 6 an optical fiber 1 shown. Here is the exit side 4 of the optical fiber 1 shown enlarged. On a Glasfaserfacette is a transmission optics 8th imprinted, which can focus or expand a beam at a decoupling. Every fiber 6 can each have such a transmission optics 6 exhibit.

The 3 shows a schematic representation of a LIDAR device 10 according to a first embodiment. The LIDAR device 10 has a laser 12 up, a ray 14 generated. The generated beam 14 will be on the entrance page 2 in the optical fiber 1 coupled. The optical fiber 1 is in the rotatable deflection device 16 positioned and has a bend of 90 °. The deflection device 16 can by actuators or motors, not shown, about an axis of rotation R to be turned around. The optical fiber 1 is in this case in the deflection device 16 arranged that the entrance side 2 in the axis of rotation R lies. Because the laser 12 also in the rotation axis R lies, can generate rays 14 regardless of a rotation of the deflection device in the optical waveguide 1 be coupled. A lens 18 focuses the generated beam 14 on the bundled glass fibers 6 on the entrance side 2 of the optical fiber 1 , Due to the bending of the optical waveguide 1 follow coupled beams of the shape of the optical waveguide 1 and are also deflected by 90 ° on the exit side 4 from the optical fiber 1 decoupled. Because the glass fibers 6 on the exit side 4 Vertically stacked, the generated beam 14 into several partial beams 20 cleaved, which are fanned over a vertical scanning area. Thus, a larger vertical scanning area can be exposed. The deflection device 16 also has a receiving optics 22 on. The on an object 24 reflected partial beams 26 be from the receiving optics 22 received and via a likewise in the deflection device 16 positioned mirror 28 to a detector 30 reflected. The reflected rays 20 become beams 32 pointing to the detector 30 be steered. The detector 30 According to the embodiment, a ring detector is the one around the laser 12 is arranged around and with the laser 12 is executed stationary or immovable.

In the 4 is a LIDAR device 10 shown according to a second embodiment. Unlike the first embodiment, the LIDAR device 10 a detector 30 on, in the form of a 2D array 30 is executed. The detector 30 is according to the embodiment on a the laser 12 arranged opposite side. For this purpose, the deflection device 16 a receiving optics 22 and a mirror 28 on, which are arranged according to the reflected rays 26 from the laser 12 to steer off. The detector 30 lies in the axis of rotation R and can be rotationally symmetrical. Thus, reflected rays can 26 and subsequently received rays 32 on the detector 30 be directed. Here, only the orientation of the received beams varies 32 on the detector 30 as this is outside the deflector 16 and thus is stationary.

The 5 illustrates a LIDAR device 10 according to a third embodiment. Unlike the ones already mentioned Embodiments is the detector 30 in or on the rotatable deflection device 16 arranged. Here is the detector 30 a line detector 30 who received the rays 32 in-situ or during the rotation of the deflection device 16 detected.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been 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.

Cited patent literature

• DE 102011107594 [0002]

Claims (11)

LIDAR device (10) for scanning a scanning area with a statically arranged laser (12) for producing at least one steel (14), with a deflection device (16) rotatable along an axis of rotation (R) for deflecting the at least one generated beam (14) in the scanning region and with a receiving optical system (22) for receiving and deflecting the at least one beam (26) reflected by an object (24) onto a detector (30), characterized in that the deflection device (16) comprises an optical waveguide (1). with at least two parallel glass fibers (6) as at least one core of the optical waveguide (1) and that the at least two parallel glass fibers (6) on an exit side (4) of the optical waveguide (1) are arranged offset from each other. Device after Claim 1 in which an entry side (2) of the optical waveguide (1) forms the axis of rotation (R) and the laser (12) generates a beam (14) which passes through the axis of rotation (R). Device after Claim 1 or 2 , wherein the glass fiber (6) on the inlet side (2) of the optical waveguide (1) are arranged in a cluster. Device according to one of Claims 1 to 3 , wherein the glass fiber (6) on the outlet side (4) of the optical waveguide (1) each have their own transmitting optics (8). Device according to one of Claims 1 to 4 , wherein the glass fiber (6) on the outlet side (4) of the optical waveguide (1) have a common transmission optics (8). Device according to one of Claims 1 to 5 wherein the deflection device (16) is rotatable along a 360 ° angle. Device according to one of Claims 1 to 6 , wherein the vertically stacked glass fibers (6) on the outlet side (4) of the optical waveguide (1) form a linear beam (20). Device according to one of Claims 1 to 7 wherein the detector (30) is annular shaped and statically disposed about the laser (12). Device according to one of Claims 1 to 8th wherein the detector (30) is arranged statically next to the laser (12) or on a side of the device (10) opposite the laser (12). Device according to one of Claims 1 to 9 wherein the detector (30) is arranged in the deflection device (16). Method for operating a LIDAR device (10) according to one of the preceding claims, wherein - at least one beam (14) is generated by a laser (12) and coupled into a deflection device (16), - the at least one beam (14) the deflection device (16) is deflected and radiated along a scanning angle, - at least one beam (26) reflected by an object (24) is directed by a receiving optical system (22) onto a detector (30), characterized in that the at least one generated beam Beam (14) in an in the deflection device (16) arranged optical waveguide (1) with at least two glass fibers (6) for deflecting the generated beam (14) is coupled and at an exit side (4) of the optical waveguide (1) of at least one generated Beam (14) from the at least two glass fibers (6) as at least two mutually offset partial beams (20) is coupled out.

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