LIDAR device (100) for detecting an object

Abstract

LIDAR device (100) for detecting an object having • a transmitting unit (101) with at least one laser (102, 102-A to 102-G) for emitting at least one laser beam (103-1); and • a receiving unit (104) for receiving laser light (201) reflected from the object; wherein the transmitting unit (101) continues • comprising at least one beam duplication unit (105) for duplicating the at least one laser beam (103-1) into at least two duplication beams (103-2), wherein • the beam multiplication unit (105) is configured to transmit; and • the beam multiplication unit is designed as a refractive optical element (600), characterized in that • at least one side of the optical refractive element (600) is designed as a planar surface (604); and that a side (605) of the refractive optical element opposite the planar surface (604) has at least two adjacent areas (601, 602, 603), wherein the at least two areas (601, 602, 603) have different slopes.

Description

[0001] The present invention relates to a LIDAR device for detecting an object, a work device and / or vehicle which is equipped with a LIDAR device, and a method for detecting an object with a LIDAR device. State of the art

[0002] EP 2 388 615 A1 discloses a LiDAR-based 3D point cloud measurement system. The measurement system comprises a base, a housing, a plurality of photon transmitters and photon detectors contained within the housing. The system further includes a rotary motor that rotates the housing around the base and a communication component that enables the transmission of signals from the photon detectors to external components.

[0003] DE 10 2015 105 393 A1 describes a laser sensor for a motor vehicle, comprising a transmitting device for emitting a transmit signal in the form of optical radiation, a deflecting device for deflecting the emitted transmit signal and a receiving device for receiving the transmit signal reflected by an object in an area surrounding the motor vehicle.

[0004] Document DE 10 2017 116597 A1 discloses a transmitting device for a scanning optical detection system of a vehicle. The transmitting device comprises at least one light source for generating at least one optical transmit signal and at least one diffraction unit that acts diffractively on the at least one transmit signal for controlling at least one beam direction of the at least one transmit signal.

[0005] DE 10 2006 060 108 A1 discloses a laser scanner based on the time-of-flight principle with a pulsed laser that emits successive light pulses into a measuring area. The laser scanner further comprises a light receiving arrangement that receives the light pulses reflected by an object in the measuring area and supplies them as electrical reception signals to an evaluation unit. Taking the speed of light into account, the evaluation unit determines a distance signal representative of the object's distance from the laser scanner based on the time between the emission and reception of the light pulse.

[0006] DE 10 2011 000 978 A1 discloses an optoelectronic sensor, in particular a laser scanner, comprising a light transmitter for emitting a light beam into a monitoring plane, a light receiver for generating a received signal from the light beam remitted by objects in the monitoring plane, a movable deflection unit, in particular a rotating mirror, for periodically deflecting the light beam in order to scan the monitoring plane during movement, and an evaluation unit for detecting the objects on the basis of the received signal.

[0007] Document DE 199 27 501 A1 discloses a transmitting device for a laser scanner with at least one laser light source for generating at least one laser light beam, wherein the laser light beam is emitted in a rotating manner. Disclosure of the invention

[0008] The present invention relates to a LIDAR device for detecting an object comprising a transmitting unit with at least one laser for emitting at least one laser beam and a receiving unit for receiving laser light which has been reflected by the object.

[0009] According to the invention, the transmitting unit further comprises at least one beam multiplication unit for multiplying the at least one laser beam into at least two multiplication beams.

[0010] The advantage of the invention lies in the fact that the resolution of the LiDAR device can be increased in at least one plane without increasing the number of lasers required. It is possible to achieve a higher resolution than in known LiDAR devices with the same number of lasers in the transmitting unit. It is also possible to achieve the same resolution as in known LiDAR devices with fewer lasers in the transmitting unit. Instead of using n lasers for n resolution planes, a single laser in the transmitting unit can suffice to achieve the same number n resolution planes. This makes it possible to eliminate a large number of other electronic components in the LiDAR device. As a result, the LiDAR device can be manufactured more cost-effectively. The installation space of the LiDAR device can be reduced. The number of adjustment steps can be minimized.

[0011] By multiplying the at least one laser beam into at least two additional beams, a beam fan is formed. This beam fan can consist of diverging additional beams. The at least two additional beams can be emitted at different angles to the at least one laser beam. Due to the angular distribution of the additional beams, the different resolution planes are formed within a single plane. Thus, the resolution of the LIDAR device can be increased in at least one plane.

[0012] The laser light received by the receiver can be evaluated using conventional time-of-flight methods. For this purpose, the LIDAR device can include a suitable evaluation unit. This evaluation unit can be designed to determine the time of flight of the emitted and received laser light. Such time-of-flight methods include pulse methods, which determine the reception time of a reflected laser pulse, and phase methods, which emit amplitude-modulated laser light and determine the phase shift relative to the received laser light.

[0013] In an advantageous embodiment of the invention, the beam multiplication unit is further configured to deflect the at least two multiplication beams in a vertical plane and additionally or alternatively in a horizontal plane. A horizontal plane can be understood as a plane perpendicular to the vertical direction. A vertical plane can be understood as a plane parallel to the vertical direction.

[0014] The advantage of this design is that the vertical resolution, and additionally or alternatively the horizontal resolution, of a LiDAR device can be increased. This increase in resolution can be achieved cost-effectively.

[0015] The beam multiplication unit is designed to be either transmitting or reflective.

[0016] The advantage of this design is that the beam multiplication unit can be individually adapted to the beam path of the LIDAR device.

[0017] In a further advantageous embodiment of the invention, the beam multiplication unit is designed as a diffractive optical element. A diffractive optical element can, for example, be an optical grating. A diffractive optical element can be a holographic optical element. Both phase-shifting (for example, phase gratings) and absorbing (for example, amplitude gratings) designs are possible. The at least two multiplication beams are generated by interference at the diffractive optical element.

[0018] The advantage of this design is that it allows for good control over the resolution in at least one plane. The diffractive optical element enables good control over the vertical resolution of the LiDAR device. The diffractive optical element enables good control over the vertical field of view of the LiDAR device. The diffractive optical element can be easily and individually adapted to the requirements of the LiDAR device. For example, by adjusting the grating parameters (grating period, slit width, number of illuminated slits), the angular spacing as well as the intensity distribution across the angles can be controlled. The angular distribution of the multiplication beams can be adapted to the receiving unit. The diffractive optical element can be designed so that the Fourier transform of the reflected or reflected beams is...The transmission function of the diffractive optical element corresponds to the desired light intensity distribution in the far field.

[0019] The beam multiplication unit is designed as a refractive optical element. At least two multiplying beams are generated by the refraction of light at the refractive optical element.

[0020] The advantage of this design is that it allows good control over the resolutions of at least one level.

[0021] At least one side of the refractive optical element is designed as a planar surface. A side of the refractive optical element opposite the planar surface usually has at least two adjacent areas, wherein the at least two areas have different slopes.

[0022] The advantage of this design is that both the resolution in a vertical plane and the resolutions of a horizontal plane can be increased.

[0023] In a further advantageous embodiment of the invention, the LIDAR device further comprises a control unit configured to control the at least one laser. The control unit can also be configured to control other components of the LIDAR device. For example, the LIDAR device can include a deflection unit. The control unit can be configured to control the deflection unit.

[0024] In a further advantageous embodiment of the invention, it is provided that the transmitting unit has at least two lasers.

[0025] The advantage of this design is that the resolution of the LIDAR device can be increased even further in at least one plane.

[0026] In a further advantageous embodiment of the invention, it is provided that the at least two lasers can be controlled with a time offset. The at least two lasers can be controlled by means of a control unit of the LIDAR device.

[0027] The advantage of this design is that by emitting the respective laser beams of the at least two lasers at different times, it is possible to more easily distinguish the laser light received by the receiving unit.

[0028] A work device and / or a vehicle is also claimed, which is equipped with a LiDAR device described above. In particular, a described LiDAR device can be advantageous for highly automated driving functions in a highly automated vehicle. A described LiDAR device can also be advantageous for automated driving functions in a fully automated vehicle. For a highly automated or fully automated vehicle, a higher resolution in at least one plane leads to better recognition of the vehicle's surroundings.

[0029] A method for detecting an object with a LIDAR device is also claimed. The method comprises the step of controlling a transmitter unit with at least one laser to emit at least one laser beam and the step of receiving laser light reflected from the object. The method further comprises the step of multiplying the at least one laser beam into at least two multiplying beams by means of a beam multiplication unit. The transmitter unit can be controlled by means of a control unit. Drawings

[0030] Exemplary embodiments of the present invention are explained in more detail below with reference to the accompanying drawings. Identical reference numerals in the figures denote identical or equivalently acting elements. The figures show: Fig. 1 a side view of a first embodiment of a LIDAR device; Fig. 2 a top view of a first embodiment of a LIDAR device; Fig. 3 a top view of a second embodiment of a LIDAR device; Fig. 4 a side view of a third embodiment of a LIDAR device; Fig. 5 a top view of a fourth embodiment of a LIDAR device; Fig. 6 an embodiment of a beam duplication unit; Fig. 7 an embodiment of a method for detecting an object with a LIDAR device.

[0031] Fig. Figure 1 shows an exemplary side view of a first embodiment of the LIDAR device 100. The LIDAR device 100 has a transmitter unit 101 with a laser 102. The laser 102 emits the laser beam 103-1. The LIDAR device 100 also has the beam multiplication unit 105. The beam multiplication unit 105 can be configured as a diffractive optical element or as a refractive optical element. The laser beam 103-1 strikes the beam multiplication unit 105 and is multiplied into the multiplication beams 103-2. The laser beam 103-1 is multiplied in a vertical plane. The arrows 108 mark the field of view of the LIDAR device 100 into which the multiplication beams 103-2 are emitted. If an object is located in the field of view 108, the duplication rays 103-2 can be scattered by the object.The multiplication beams 103-2 can be reflected by the object. The LIDAR device 100 also includes the receiver unit 104. The receiver unit 104 can receive laser light reflected from the object. The signals generated from the received laser light can be evaluated by means of an evaluation unit (not shown here). The LIDAR device 100 is mounted on a rotatable unit 106. The rotatable unit 106 can be rotated about the axis of rotation 107. This rotation deflects the multiplication beams 103-2 in the horizontal plane, thus achieving resolution in the horizontal plane as well. The LIDAR device 100 can also include a control unit (not shown here). The control unit can be configured to control the rotatable unit 106 or the laser 102.Not shown here, the LIDAR device 100 can also have additional optical elements, such as optical lenses, mirrors and the like.

[0032] Fig. Figure 2 shows the LIDAR device 100 from Fig. 1 in a top view. Identical reference symbols denote identical or equivalent elements. As in Fig. As is clearly shown in Figure 2, the beam multiplication unit 105 is designed to transmit. Arrows 201 illustrate the laser light reflected from the object and received by the receiver unit 104.

[0033] Fig. Figure 3 shows an exemplary top view of a second embodiment of a transmitting unit 101 of a LIDAR device. Identical reference numerals denote identical or equivalent elements as in Figure 3. Fig. 1 or Fig. 2. The beam multiplication unit 105 can be configured as a diffractive optical element or as a refractive optical element. In this embodiment, the beam multiplication unit 105 is configured as a reflector.

[0034] Fig. Figure 4 shows a side view of a third embodiment of a LIDAR device 100. The transmitter unit 101 has several lasers 102. The transmitter unit 101 has in Fig. Figure 4 shows, purely as examples, the seven lasers 102-A to 102-G. The lasers 102-A to 102-G are arranged one above the other. Each laser emits a laser beam. The emitted laser beam 103-1-A is marked as an example for laser 102-A. The beam multiplication unit 105 is also shown. The beam multiplication unit 105 can be configured as a diffractive optical element or as a refractive optical element. Each of the laser beams 103-1-A to 103-1-G emitted by lasers 102-A to 102-G strikes the beam multiplication unit 105 and is multiplied. The emitted laser beams 103-1-A to 103-1-G are multiplied into the duplicating beams 103-2-A to 103-2-G. Each of the emitted laser beams 103-1-A to 103-1-G is multiplied into a beam bundle 103-2-A to 103-2-G consisting of three duplicating beams.The laser beams 103-1-A to 103-1-G are multiplied in a vertical plane. The beam multiplication unit 105 is configured to transmit. Alternatively, the beam multiplication unit 105 can be configured to reflect. The transmitter unit 101 can be connected to a control unit 401 of the LIDAR device, as shown. The control unit 401 can control the lasers 102-A to 102-G. The control unit can control the lasers 102-A to 102-G individually. The LIDAR device 100 is mounted on a rotatable unit 106. The rotatable unit 106 is rotatable about an axis of rotation (not shown). This rotation deflects the multiplication beams 103-2-A to 103-2-G in the horizontal plane. Thus, resolution is also achieved in the horizontal plane.

[0035] Fig. Figure 5 shows a top view of a fourth embodiment of a LIDAR device. The transmitting unit 101 includes, purely by way of example, the two lasers 102-A and 102-B. The lasers 102-A and 102-B are arranged side by side. Each laser emits a laser beam (103-1-A and 103-1-B). The beam multiplication unit 105 is also shown. The beam multiplication unit 105 can be configured as a diffractive optical element or as a refractive optical element. Each of the emitted laser beams 103-1-A and 103-1-B strikes the beam multiplication unit 105 and is multiplied. The emitted laser beams 103-1-A and 103-1-B are multiplied into the duplicating beams 103-2-A and 103-2-B. Each of the emitted laser beams 103-1-A and 103-1-B is multiplied into a beam bundle 103-2-A and 103-2-B consisting of three duplicating beams.The laser beams 103-1-A and 103-1-B are multiplied in a horizontal plane. The beam multiplication unit 105 is configured to transmit. Alternatively, the beam multiplication unit 105 can be configured to reflect. The transmitter unit 101 can be connected to a control unit 401 of the LIDAR device, as shown. The control unit 401 can control the lasers 102-A and 102-B. The control unit can control the lasers 102-A and 102-B individually. The LIDAR device 100 is mounted on a rotatable unit 106. The rotatable unit 106 is rotatable about an axis of rotation (not shown). This rotation deflects the multiplication beams 103-2-A and 103-2-B in the horizontal plane. This results in an even higher resolution in the horizontal plane.

[0036] Fig. Figure 6 shows an embodiment of a beam multiplication unit, wherein the beam multiplication unit is designed as a refractive optical element 600. The refractive optical element can, for example, be designed as a glass plate. The refractive optical element 600 has several sides. Here, the side marked 604 is designed as a flat surface. The side 605 opposite the flat surface 604 has three adjacent areas 601, 602, and 603. The three areas 601, 602, and 603 have different slopes. Alternatively, and not shown here, it would also be possible to mount three glass plates in a holder such that the three glass plates have different slopes.Alternatively, and not shown here, it would also be possible for the refractive optical element 600 to be designed as a deflecting mirror with at least two areas, wherein the at least two areas have different slopes.

[0037] Fig. Figure 7 shows an embodiment of a method 700 for detecting an object with a LIDAR device. The method 700 starts in step 701. In step 702, a transmitter unit with at least one laser is controlled to emit at least one laser beam. In step 703, the at least one laser beam is multiplied into at least two multiplication beams by means of a beam multiplication unit. In step 704, laser light reflected from the object is received. The method ends in step 705.

Claims

[1] LIDAR device (100) having an object detection • a transmitting unit (101) with at least one laser (102, 102-A to 102-G) for emitting at least one laser beam (103-1); and • a receiving unit (104) for receiving laser light (201) reflected from the object; wherein the transmitting unit (101) continues • comprising at least one beam duplication unit (105) for duplicating the at least one laser beam (103-1) into at least two duplication beams (103-2), wherein • the beam multiplication unit (105) is configured to transmit; and • the beam multiplication unit is designed as a refractive optical element (600), characterized by , that • at least one side of the optical refractive element (600) is designed as a planar surface (604); and that a side (605) of the refractive optical element opposite the planar surface (604) has at least two adjacent areas (601, 602, 603), wherein the at least two areas (601, 602, 603) have different slopes. [2] LIDAR device (100) according to claim 1, characterized by , that the beam duplication unit (105) is further configured to deflect the at least two duplication beams (103-2) in a vertical plane and / or in a horizontal plane. [3] LIDAR device (100) according to one of claims 1 to 2, characterized by , that the beam multiplication unit (105) is designed as a diffractive optical element. [4] LIDAR device (100) according to any one of claims 1 to 3, wherein the transmitting unit (101) has at least two lasers (102A to 102-G). [5] LIDAR device (100) according to claim 4, characterized by that at least two lasers (102-A to 102-G) can be controlled with a time offset. [6] Working device and / or vehicle which is equipped with a LIDAR device (100) according to any one of claims 1 to 5. [7] Method (700) for detecting an object with a LIDAR device (100) comprising the steps: • Control (702) of a transmitting unit (101) with at least one laser (102, 102-A to 102-G) for emitting at least one laser beam (103-1); and • Receiving (704) laser light (201) reflected from the object; showing the further step • the duplication (702) of the at least one laser beam (103-1) into at least two duplication beams (103-2) by means of a beam duplication unit (105), wherein • the beam multiplication unit is configured to transmit; and wherein • the beam multiplication unit is designed as a refractive optical element; and wherein • at least one side of the optical refractive element is designed as a planar surface; and that a side of the refractive optical element opposite the planar surface has at least two adjacent areas, wherein the at least two areas have different slopes.

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