阅读说明：本技术 用于以至少一个恒定定向的射束对扫描角进行扫描的激光雷达设备和方法 (Lidar device and method for scanning a scanning angle with at least one constantly oriented beam ) 是由 A·霍莱切克 M·拜尔 于 2018-05-09 设计创作，主要内容包括：本发明涉及一种激光雷达设备(1),所述激光雷达设备用于以至少一个射束(16)对扫描角进行扫描,所述激光雷达设备具有至少一个射束源(2)、能够旋转的偏转单元(18)并且具有探测器,所述至少一个射束源用于产生所产生的至少一个射束(4),所述能够旋转的偏转单元用于使所产生的至少一个射束(4)偏转,所述探测器用于接收在对象上反射的至少一个射束,其中,在至少一个射束(8)的光路中在所述射束源(2)与所述偏转单元(18)之间布置有至少两个柱形透镜(12,14),其中,至少一个柱形透镜(12,14)是能够旋转的。此外,公开一种用于运行激光雷达设备(1)的方法。(The invention relates to a lidar device (1) for scanning a scanning angle with at least one beam (16), having at least one beam source (2) for generating at least one generated beam (4), a rotatable deflection unit (18) for deflecting the generated at least one beam (4), and having a detector for receiving the at least one beam reflected on an object, wherein at least two cylindrical lenses (12, 14) are arranged in the beam path of the at least one beam (8) between the beam source (2) and the deflection unit (18), wherein the at least one cylindrical lens (12, 14) is rotatable. Furthermore, a method for operating a lidar device (1) is disclosed.)

1. Lidar device (1) for scanning a scanning angle with at least one beam (16), having at least one beam source (2) for generating at least one generated beam (4), a rotatable deflection unit (18) for deflecting the at least one generated beam (4), and having a detector for receiving the at least one beam reflected on an object, characterized in that at least two cylindrical lenses (12, 14) are arranged in the optical path of the at least one beam (8) between the beam source (2) and the deflection unit (18), wherein the at least one cylindrical lens (12, 14) is rotatable.

2. Lidar device according to claim 1, wherein the deflection unit (18) has the following spacing to a cylindrical lens (14) adjacent to the deflection unit (18): the spacing corresponds to the focal length of the adjacent cylindrical lens (14).

3. Lidar device according to claim 2, wherein the at least two cylindrical lenses (12, 14) are arranged rotated with an angle of 45 ° to each other.

4. Lidar device according to claim 1, wherein the deflection unit (18) has the following spacing to a cylindrical lens (14) adjacent to the deflection unit (18): the spacing is greater than the focal length of the adjacent cylindrical lens (14).

5. Lidar device according to claim 4, wherein the at least two cylindrical lenses (12, 14) are arranged rotated by an angle of 90 ° with respect to each other.

6. Lidar device according to any of claims 1 to 5, wherein at least one cylindrical lens (12, 14) is rotatable synchronously with the deflection unit.

7. Lidar device according to any of claims 1 to 6, wherein at least one cylindrical lens (12) is fixedly arranged.

8. Lidar device according to any of claims 1 to 7, wherein the generated at least one beam (4, 8) has a line shape.

9. Lidar device according to any of claims 1 to 8, wherein the generated at least one beam (4, 8) has a point shape.

10. Lidar device according to any of claims 1 to 9, wherein the deflection unit (18) has a flat or curved mirror.

11. Method (22) for operating a lidar device (1) according to any of the preceding claims for scanning a scanning angle with at least one beam (16), wherein,

generating (24) at least one beam (4);

-matching (26) at least one beam (8) by generating optics (6);

rotating (28) the at least one beam (8) about the optical axis (A) by means of at least one rotatable cylindrical lens (12, 14);

deflecting (30) at least one beam (16) along a scanning angle by means of a rotatable deflection unit (18);

at least one beam reflected on the object is received and recorded (32) by the detector.

Technical Field

The invention relates to a lidar device for scanning a scanning angle with at least one beam and to a method for operating a lidar device.

Background

Current lidar (light detection and ranging) devices utilize a laser or a beam source to generate a laser beam, which may then be deflected by a deflection unit, such as a rotatable mirror, and by a scanning area. The beam is generated by the beam source in such a way that it extends through the axis of rotation of the deflection unit and is deflected perpendicular to the axis of rotation by an angle of approximately 45 °. The scanning area can be scanned by rotation at a horizontal angle of 360 ° around the lidar device. The detector may receive and analyze the reflected beam. In this case, both the laser source and the detector can be arranged in a stationary manner. However, in such a lidar device, the beam reflected by the deflection unit changes its orientation, for example, by a horizontal angle of, for example, 360 ° by rotation of the deflection unit. If, for example, a linear beam is generated, line illumination cannot be achieved without rotation of the line orientation through large spatial angles. In the case of large horizontal angles, the initially vertically oriented line beam is rotated by the deflection unit as it rotates in such a way that it can be emitted into the scanning region in a horizontally or diagonally oriented manner.

Disclosure of Invention

The object on which the invention is based may be to provide a method and a lidar device for scanning a scanning region with at least one beam, which has a constant orientation over the entire scanning range.

The object is achieved by means of the corresponding subject matter of the independent claims. Advantageous embodiments of the invention are the subject matter of the respective dependent claims.

According to an aspect of the invention, a lidar device for scanning a scan angle with at least one beam is provided. The laser radar apparatus has: at least one beam source for generating at least one beam; optionally generating optics for shaping the generated at least one beam; and a rotatable deflection unit for deflecting the generated at least one beam. Furthermore, the lidar device has a detector for receiving the at least one beam reflected on the object, wherein at least two cylindrical lenses (zylindine) are arranged in the beam path of the at least one beam between the optional generation optics or beam source and the deflection unit, wherein the at least one cylindrical lens is rotatable.

In this case, at least one electromagnetic beam can be generated by at least one beam source. The beam source may be, for example, a laser. At least one beam can be shaped by means of optional generation optics. A radiation beam embodied in a point-like or circular manner can be focused, for example, into a line. Thus, the optional generating optics may be, for example, a cylindrical lens, a fresnel lens, a diffractive optical element, a tandem cylindrical lens (tandemzylinderline), or the like. Alternatively or additionally, the generated at least one beam may be shaped as a grid of points (Punktraster). The optional generation optics have an additional beam splitter or generate a plurality of beams by a plurality of beam sources. In the grid of points, the individual points are each shaped by the generated beam. The grid of points may be shaped, for example, as a line, circle, rectangle, etc. By inserting a suitable beam deflection before the rotatable deflection unit, the line or point grid can be emitted into the surroundings or the scanning area across all spatial directions with the line orientation maintained. Thus, it may be counter-acted to the rotation of the orientation of the beam generated and deflected by the deflection unit. This may similarly be applied in the case of the generated point grid. The generated dots of the dot matrix are thereby exchanged twice in terms of their sequence during a rotation of the deflection unit, for example 360 °. The tilting or rotation of the generated at least one beam causes a continuous change in the area of the generated and shaped at least one beam and thus also a change in the scanning range of the lidar device or a change in the vertical scanning angle of the lidar device. At least two combined cylindrical lenses are arranged to be rotated with respect to each other at an angle. The cylindrical lenses have a distance from each other smaller than the focal length of the cylindrical lenses. Advantageously, the cylindrical lenses have the same optical properties, such as focal length, geometry and refractive index. Alternatively, the cylindrical lenses may be different from each other in their optical characteristics. Here, at least one cylindrical lens is arranged so as to be rotatable about its optical axis. In this case, a plurality of cylindrical lenses may also be arranged as a composite body so as to be jointly rotatable. In a complex, the cylindrical lenses may have a defined constant or variable angular offset (winkelverssatz) from each other. The optical axis of the cylindrical lens is preferably simultaneously the optical axis of the at least one radiation beam produced. Here, the at least one cylindrical lens or the complex of the at least two cylindrical lenses may be rotated in synchronization with the rotation of the deflection unit. Alternatively or additionally, the rotational speed can be reduced or increased depending on the field of application of the lidar device. Thereby, for example, the vertical scanning angle can be changed and, for example, the vertical scanning width of the scanning area can be reduced or increased. Since the at least one beam impinges on the deflection unit with the same orientation during the entire rotation, the orientation and distribution of the at least one beam does not change or changes in a defined manner at all radiation angles of the deflection device. The at least one beam generated and already shaped is rotated in at least two steps by using at least two cylindrical lenses arranged rotationally with respect to each other. Thereby, as much optical information of the generated and shaped beam as possible is transmitted through the cylindrical lens and losses are minimized.

According to an embodiment of the lidar device, the deflection unit has the following spacing to the cylindrical lens adjacent to the deflection unit: the pitch corresponds to the focal length of the adjacent cylindrical lens. Thereby, a beam focused by a cylindrical lens adjacent to the deflection unit is focused onto the deflection unit. The deflection unit is therefore located at the focal point of the adjacent cylindrical lens and enables optimum imaging of the beam in the scanning region by the deflection unit.

According to a further embodiment of the lidar device, the at least two cylindrical lenses are here arranged rotated by an angle of 45 ° with respect to each other. The originally circular beam produced by the beam source is shaped into a line by means of optional generating optics or a first cylindrical lens. The line beam can be rotated on the deflection unit by two further cylindrical lenses arranged rotated 45 ° to each other. The deflection unit may be, for example, a rotatable mirror.

According to another embodiment of the device, the deflection unit has the following pitch to the cylindrical lens adjacent to said deflection unit: the distance is greater than the focal length of the adjacent cylindrical lenses. Thus, the deflection unit may have the following spacing to the cylindrical lens: the pitch is larger than a focal length to a cylindrical lens arranged closest to the deflection unit. Thereby, the laser radar apparatus can be flexibly constructed and is not limited by the optical characteristics of the cylindrical lens. In this case, the at least two cylindrical lenses are preferably arranged at an angle of 90 ° with respect to one another. Since the deflection unit is further away than its focal length from the cylindrical lenses adjacent to the deflection unit, the cylindrical lenses have to be arranged rotated to each other by an angle of 90 ° in order for the rotation of the beam to be imageable on the deflection unit.

According to a preferred embodiment of the lidar device, the at least one cylindrical lens may rotate synchronously with the deflection unit. For this purpose, the at least two cylindrical lenses may be mechanically or electronically connected, for example, with the deflection unit. Thus, the cylindrical lens can be rotated as a complex at the same angular velocity as the deflection unit. The deflection unit can be used in particular as a mechanical drive for a composite of at least two cylindrical lenses or as a mechanical drive for a single cylindrical lens. Alternatively, at least two cylindrical lenses may be provided as a composite or one of the cylindrical lenses may be individually equipped with an individual drive adapted for rotation, so that the cylindrical lenses may be rotated or synchronized in correspondence with the electronic signals of the deflection unit.

According to another embodiment, the at least one cylindrical lens is fixedly arranged. Thus, the at least one cylindrical lens is fixedly arranged together with the beam source and the detector and does not rotate together. Thus, the at least one cylindrical lens is further embodied to be rotatable in order to be able to correct the orientation of the beam. Thereby, only one cylindrical lens has to be rotated together, so that the rotational mass can be reduced.

According to another embodiment, the at least one beam generated has a line shape. The generated beam can be shaped as desired by the optional generation optics, depending on the field of application and the requirements resulting therefrom. The beam may be implemented linearly, for example. Preferably, the beam has a two-dimensional line shape, by means of which the scanning area can be scanned. Advantageously, in this case, the optional generating optics is a cylindrical lens or a combination of a cylindrical lens and a further optical element. The optional generating optics can therefore be implemented technically simply in the form of a single cylindrical lens.

According to a further embodiment of the lidar device, the generated at least one beam has a point shape. Thus, the optional generating optics may have a beam splitter, diffractive optical element or the like, which may divide or fan out at least one beam produced by the beam source

Into a plurality of beams. Preferably, the individual beams form individual beam spots which can be used for irradiating the scanning region. The scanning area may be illuminated pulsed or continuously by a grid of points. The laser radar device can thus also be designed coaxially and simultaneously transmit the generated beam and receive the reflected beam. For this purpose, the generated beam and the reflected beam can have at least one slight offset from one another and preferably impinge on different regions on the deflection unit. Since the at least one cylindrical lens is embodied to be rotatable, the resulting point grid with the individual beams maintains its orientation independently of the orientation of the deflection unit. Thereby, the order of the individual beams remains constant.

According to another embodiment of the lidar device the deflection unit has a plane mirror or a curved mirror. In a technically simple embodiment, the deflection unit can be embodied in the form of a rotatable or pivotable mirror. Alternatively, the mirror may have a curved or contoured surface that may be configured to correct for aberrations of the cylindrical lens.

According to a further aspect of the invention, a method is provided for operating a lidar device for scanning a scanning angle with at least one beam. At least one beam is generated and shaped by optional generation optics. Subsequently, the at least one beam is rotated about the optical axis by means of the at least one rotatable cylindrical lens and imaged onto the deflection unit. At least one beam can be deflected along a scanning angle by a deflection unit. If an object is located in the scanning region, at least one beam reflected on the object is received by a detector via an optional receiving optical system and converted into an electrical signal. The electrical signal may then be processed and analyzed.

The generated and shaped beam or beams can be rotated directly or indirectly by means of at least one rotatable cylindrical lens in accordance with the deflection unit. Thus, the orientation of the at least one beam may be corrected, influenced or constantly oriented when illuminating the scan area. Preferably, at least one beam generated and shaped by the optional generation optics is rotated by at least two cylindrical lenses. In this way, at least one beam is rotated in a plurality of stages about its optical axis and aligned in accordance with the orientation of the deflection unit.

Drawings

Preferred embodiments of the invention are explained in detail below on the basis of strongly simplified schematic drawings. In this case, the amount of the solvent to be used,

fig. 1 shows a schematic diagram of a lidar apparatus according to a first embodiment;

fig. 2 shows the imaging of the beam on the deflection unit in the case of different rotational angle positions of the cylindrical lens complex (zylindenverBund) of the lidar apparatus according to the first embodiment;

fig. 3 shows a schematic diagram of a lidar apparatus according to a second embodiment;

fig. 4 shows the imaging of the beam on the deflection unit in the case of different rotational angle positions of the cylindrical lens complex of the lidar apparatus according to a second embodiment;

fig. 5 shows a schematic diagram of a lidar apparatus according to a third embodiment;

fig. 6 shows the imaging of the beam on the deflection unit in the case of different rotational angle positions of the cylindrical lens complex of the lidar device according to the first embodiment;

fig. 7 shows a method for scanning a scanning area according to a first embodiment.

In the figures, identical structural elements have identical reference numerals, respectively. For purposes of clarity, only the major structural elements that are necessary to understand the invention are numbered in the drawings.

Detailed Description

Fig. 1 shows a schematic diagram of a lidar device 1 according to a first embodiment. The lidar device 1 has a beam source 2 for generating at least one electromagnetic beam 4. According to this embodiment, the beam source 2 is a laser 2 generating a laser beam 4. The generated radiation beam 4 impinges on generating optics 6. The generating optics 6 are a cylindrical lens 6 which focuses the generated beam 4 in the vertical direction V and expands in a fan-shaped manner into a linear beam 8 after the focus of the cylindrical lens 6. The line beam then strikes a cylindrical lens complex 10, which is composed of two cylindrical lenses 12, 14. The cylindrical lens complex 10 is implemented to be rotatable as a whole. Here, the optical axis a of the laser radar apparatus 1 serves as a rotation axis. According to this embodiment, the two cylindrical lenses 12, 14 are arranged rotated to each other by a constant angle of 45 °. In both steps, the radiation beam 8 is rotated about the optical axis a by means of a rotatable cylindrical lens complex 10. The rotated beam 16 can then be imaged onto a rotatable deflection unit 18. The deflection unit 18 reflects the rotated beam 16 along the scan area. The deflection unit 18 may be, for example, a rotatable mirror 18. According to this embodiment, the deflection unit 18 has the following spacing to its adjacent cylindrical lens 14: the pitch corresponds to the focal length of the cylindrical lens 14. The cylindrical lens complex 10 rotates synchronously with the deflection unit 18 and orients the beam 8 such that the rotated beam 16 strikes the deflection unit 18 with a constant orientation and is therefore reflected into the scanning region with a constant orientation.

Fig. 2 shows an imaging 20 of the rotated beam 16 on the deflection unit 18 with different angles of rotation of the entire cylindrical lens complex 10 of the lidar device 1 according to the first embodiment. The angle of rotation of the cylindrical lens complex 10 is shown here in relation to the orientation of the cylindrical lens complex 10 according to fig. 1, which shows an angle of rotation of 90 °.

Fig. 3 shows a schematic diagram of a lidar device 1 according to a second exemplary embodiment. In contrast to the first exemplary embodiment, lidar device 1 has a deflection unit 18, which deflection unit 18 is arranged at a distance from adjacent cylindrical lens 14. Here, the pitch is larger than the focal length of the cylindrical lens 14. In order to be able to optimally image the rotated beam 16 on the deflection unit 18, the cylinder lenses 12, 14 of the cylinder lens complex 10 are rotated at an angle of 90 ° to one another.

Fig. 4 shows an image 20 of the rotated beam 16 on the deflection unit 18 in the case of different rotational angular positions of the cylindrical lens complex 10 of the lidar device 1 according to the second exemplary embodiment. According to fig. 3, the cylindrical lens complex 10 has a rotation angle of 0 °. The imaging 20 shows the shape of the beam 16 rotated for calibration purposes when it strikes the deflection unit 18 at different rotational angular positions of the cylindrical lens complex 10.

Fig. 5 shows a schematic diagram of a lidar device 1 according to a third embodiment. Unlike the embodiment that has been shown, the lidar apparatus 1 does not have a cylindrical lens complex that rotates in its entirety. The cylindrical lens 12 with the generating optics 6 is embodied here as fixed or non-rotatable. According to this embodiment, the cylindrical lens 14 arranged adjacent to the deflection unit 18 is rotatably supported about the optical axis a. The cylindrical lens 14 is embodied so as to be rotatable synchronously with the deflection unit 18 and to align the shaped beam 8 with respect to the orientation of the rotatable deflection unit 18. Similarly to the second embodiment, the deflection unit 18 is arranged outside the focal length of the adjacent cylindrical lens 14.

Fig. 6 shows an image 20 of the rotating beam 16 on the deflection unit 18 in the case of different rotational angle positions of the cylindrical lens 14 of the lidar device 1 according to the third exemplary embodiment. Here, the cylindrical lens 14 has a rotation angle of 0 ° in fig. 5. It is particularly evident here that, when the individual cylindrical lens 14 rotates, the line shape of the rotating beam 16 changes to an elliptical shape and thus reduces the imaging quality of the beam 16 in comparison with the rotatable cylindrical lens complex 10.

Fig. 7 shows a method 22 for scanning a scanning area according to a first embodiment. At least one radiation beam 4 is generated 24 and shaped 26 by the production optics 6. The shaped beam 8 is then rotated or oriented 28 by at least one rotatable cylindrical lens 12, 14 and projected onto the deflection unit 18. The deflection unit 18 reflects the beam 16 and illuminates 30 a scanning area with the beam 16. The beam 16 is rotated in such a way that the orientation of the beam 16 remains constant over the rotation range of the deflection unit. The beam 32 reflected on the object may be received and detected by a detector and optional receiving optics.