Lidar measuring device for detecting an object

Abstract

The present invention relates to a lidar measuring device (10) and to a corresponding method and computer program product for detecting an object, said lidar measuring device comprising: a first lidar measuring unit (12) having a first laser light source (13) for emitting a first laser light beam (16), and a first detector (14); a second lidar measuring unit (12') having a second laser light source (13') for emitting a second laser light beam (16') substantially parallel to the first laser light beam (16), and a second detector (14'); a rotatable deflection element (18) that is designed to deflect the first laser light beam (16) and the second laser light beam (16') in each case with respect to a fixed polar angle and, based on a rotation of the deflection element (8), with respect to an azimuth angle, wherein the deflection element (18) comprises a first side for deflecting the first laser light beam (16) in a first direction and a second side for deflecting the second laser light beam (16') in a second direction, that is preferably opposite in azimuth, and wherein the second laser light beam (16') is directed by light guiding elements (32) to the second side of the deflection element (18). The use of two lidar measuring units (12, 12') allows for the establishment of a redundant system. Additionally, a larger field of view or faster scanning can be achieved. The data yield can be increased. By using a single rotatable deflection element (8), both laser beams can be deflected, preferably by means of a single drive unit (24) and a pinion (26). A deflection element allows for a lidar measuring device that is variable in terms of its arrangement and space requirements. Calibration and diagnostics of correct functionality can be carried out during ongoing operation.

Description

[0001] University of Kassel

[0002] Lidar measuring device for detecting an object

[0003] The present invention relates to a scanning lidar measuring device for detecting an object. The present invention further relates to a corresponding method and a computer program product.

[0004] A LIDAR (light detection and ranging) system is based on the emission of light pulses and the detection of the reflected light. For example, a time-of-flight measurement can be used to calculate the distance to the location of the reflection. A target can be detected by analyzing the received reflections. Regarding the technical implementation of the corresponding sensor, a distinction is made between scanning systems, which usually function based on micromirrors, and non-scanning systems, in which several transmitting and receiving elements are arranged statically next to one another (especially so-called focal plane arrays).

[0005] Currently, Lidar systems are known that determine distances based on, for example, the time-of-flight (ToF) method, or based on the optical displacement of a laser light beam. In this case, a reflection of a laser light beam is directed onto a CMOS or CCD sensor, or a similar sensor, preferably using a lens or optical unit. This sensor can have a linear or matrix-like pixel structure.

[0006] Such lidar systems are sometimes used in safety-relevant applications, such as road traffic or autonomous manufacturing systems with robots, and scan in a single plane. Similar systems are also known from published patent applications US 5 198 919 A, DE 10 2022 200 624 A1, JP 2006 - 235 219 A, DE 25 34 695 A1, and DE 10 2019 134 192 A1.

[0007] The objective is to expand the data acquired by such a lidar system, enabling faster scanning and / or expanding the field of view. Particularly preferred is the creation of a way to set up a lidar system with at least partial redundancy and to verify the lidar system's measurements.

[0008] This problem is solved by the subject matter of the subordinate claims.

[0009] The lidar measuring device for detecting an object comprises a first lidar measuring unit, comprising a first laser light source for emitting a first laser light beam and a first detector. The lidar measuring device further comprises a second lidar measuring unit, comprising a second laser light source for emitting a second laser light beam and a second detector. A rotatable deflection element of the lidar measuring device is designed to deflect the first laser light beam and the second laser light beam, respectively, with respect to a fixed polar angle and, based on a rotation of the deflection element, with respect to an azimuth angle. The deflection element has a first side for deflecting the first laser light beam in a first direction and a second side for deflecting the second laser light beam in a second direction. The lidar measuring unit preferably comprises a single deflection element that is rotatable about a vertical axis.The first laser light beam and the second laser light beam are emitted essentially parallel to this vertical axis.

[0010] It is understood that the laser light beams are deflected essentially horizontally by the deflection element. The azimuth angle depends on the rotational position of the deflection element. A polar angle or zenith angle preferably depends on the deviation of the laser light beams around the rotational axis of the deflection element. In other words, a slight tilt leads to a change in the polar angle during a measurement.

[0011] Preferably, the laser light beams are deflected in different directions by the deflection element.

[0012] By using a first and second lidar measuring unit, a redundant system can be set up that ensures continued measurement operation if one of the two lidar measuring units fails. Furthermore, using two lidar measuring units in parallel can achieve a larger field of view or faster scanning. The data yield can be increased. The use of two lidar measuring units also makes it possible to set up an at least partially redundant system that is cost-effective, since individual parts of the lidar measuring device can be used by both lidar measuring units. A single rotatable deflection element can deflect both laser light beams, preferably using a single drive unit. A deflection element enables a lidar measuring device that is variable in terms of arrangement and installation space.

[0013] Preferred embodiments of the invention are described in the dependent claims. It is understood that the features mentioned above and those to be described below can be used not only in the respective combinations specified, but also in other combinations or on their own, without departing from the scope of the present invention. In particular, the method and the computer program product can be implemented according to the embodiments described for the device in the dependent claims.

[0014] In a preferred embodiment, the second side of the deflection element lies opposite the first side of the deflection element, wherein the deflection element is designed to deflect the first laser light beam at an azimuth angle that is 180 degrees different from the azimuth angle of the second laser light beam. The laser light beams are therefore preferably emitted in a horizontally opposite direction. The lidar measuring device preferably comprises light guide means for this purpose. Preferably, both laser light beams are initially emitted essentially parallel and offset from one another in a horizontal direction, wherein a first laser light beam directly strikes the deflection element, in particular the first side of the deflection element. The second laser light beam is preferably deflected twice by 90 degrees by the light guide means in order to strike the second side of the deflection element in a vertical direction downwards, i.e. antiparallel to the first light beam.This design of the deflection element allows for a technically simple setup. Furthermore, the precise 180-degree offset allows for advantageous and technically simple analysis, as the offset with respect to the azimuth angle remains the same for every measurement thanks to this advantageous design.

[0015] Particularly preferably, the deflection element is designed as a double-sided mirror. This makes it technically simple to create a deflection element that is suitable for use with laser beams for measurements using the lidar measuring device.

[0016] The lidar measuring device advantageously comprises a deflection element designed to deflect the first laser light beam and / or the second laser light beam with respect to a polar angle during measurement. The deflection element is particularly preferably arranged in the beam path between the laser light source and the deflection element. It is understood that this preferably initially deflects the corresponding laser light beam before it is deflected by the deflection element. This deflection in the vertical direction results in the laser light beam not running exactly horizontally after deflection by the deflection element, but is deflected in the vertical direction. It is understood that two deflection elements can also be provided for the first laser light beam and the second laser light beam. In particular, more than two lidar measuring units can also be provided, each of which can also be assigned a deflection element.

[0017] In a particularly preferred embodiment, the deflection element is designed to deflect the first laser light beam at the same polar angle as the second laser light beam in order to enable a fast scan. Alternatively, the deflection element is designed to deflect the first laser light beam at a different polar angle than the second laser light beam in order to enable a scan with a higher resolution. In particular, higher resolution means that a vertical field of view of the lidar measuring device is expanded. Deflecting at the same polar angle can enable a fast scan. Particularly in safety-critical applications, a preferred main scan plane can be defined, which can be scanned quickly as needed. Furthermore, a redundant system can be created with respect to this plane.Increasing the vertical field of view enables higher data quality and a broader range of applications for the lidar measuring device. In particular, a main plane can be defined for this case, which is scanned with each rotation of the deflection element. Secondary planes located in a different area of ​​the vertical field of view can be scanned at a lower frequency. This ensures a high sampling rate for the main plane while simultaneously establishing a high vertical field of view.

[0018] In a further advantageous embodiment, the deflection element comprises a transparent plate arranged between a laser light source and the deflection element. The transparent plate can be tilted by means of an actuator to adjust an angle between the laser light beam of the laser light source and the transparent plate or to remove the transparent plate from the laser light beam. A transparent plate, preferably a transparent plate made of glass or Plexiglas, enables the manipulation of the laser light beam in a technically simple and robust manner. By arranging the plate and the actuator between the laser light source and the deflection element, the deflection element can be arranged in a protected area of ​​the lidar measuring device.By tilting using an actuator, on the one hand the tilt position of a transparent plate can be precisely detected and on the other hand the resulting manipulation of the laser light beam with regard to its polar angle can be calculated based on known physical laws, such as the refraction of light between two media.

[0019] Advantageously, the lidar measuring device comprises a rotatable external unit with a mechanical-optical unit that is permeable to electromagnetic waves of specific wavelengths, wherein the deflection element and the external unit are coupled. By providing an external unit, the lidar measuring device can be protected from environmental influences. In particular, the influence of stray light from outside can be minimized by a mechanical-optical unit that is only permeable to specific wavelengths. By means of a coupling, the mechanical-optical unit can be rotated in a predefined ratio to the rotation of the deflection element. This can prevent contamination or damage to the external unit from leading to a blind zone of the lidar measuring device. Preferably, measurement operation can be maintained in all azimuth directions.

[0020] In a particularly preferred embodiment, the coupling between the deflection element and the external unit is established by a force-locking and / or form-locking connection between the outer base of the external unit and an inner base of the deflection element. In particular, a form-locking connection can be established in the form of an internal toothing and a corresponding external toothing. It goes without saying that other connections, such as a traction mechanism or a magnetic coupling, are also conceivable. A force-locking or form-locking connection can reliably and technically easily ensure that the coupling forces the two units, i.e., the deflection element and the external unit, to be guided or rotated relative to one another. A robust and fail-safe system can be created.In other embodiments, the coupling may also be implemented electronically, wherein a drive for the lidar measuring unit and / or the outdoor unit is controlled according to a drive for the respective other unit.

[0021] In an advantageous embodiment, the lidar measuring device comprises an optical unit designed to reflect a laser light beam back to the detector. Additionally, the lidar measuring device comprises a diagnostic unit for diagnosing the functionality of a lidar measuring device based on a measurement of the laser light beam when the laser light beam strikes the optical unit and is reflected back to a detector, and the detector signal during this measurement. Particularly preferably, the optical unit is arranged on the mechanical-optical unit. An optical unit that reflects the laser light beam back to the detector at a known distance allows calibration of the lidar measuring device, preferably at regular intervals. In particular, calibration and diagnosis of correct functionality can be performed during ongoing operation. This allows malfunctions to be detected quickly.Confidence in a measurement with the lidar measuring device can be increased. It is understood that if the optical unit is arranged on the external unit, the position of the optical unit can be precisely calculated due to the coupling and forced rotation. Consequently, an expected distance or an expected measurement signal can also be pre-calculated during calibration. This allows calibration to be carried out at different angular positions. It is understood that both lidar measuring units can be calibrated using the optical unit, as described above. It is understood that the optical unit can also comprise multiple reflective elements. In particular, it is conceivable to calibrate during each scan. In this case, the optical unit could, for example, be a type of cylinder formed by a collection of many vertical prisms.The laser light beam hits the optical unit and is reflected back to the detector. Based on the detector signal from this measurement, the diagnostic unit diagnoses the functionality of the lidar measuring device.

[0022] Preferably, the optical unit is designed as a beam splitter so that, in addition to the calibration or diagnostic measurement, a distance measurement can also be carried out.

[0023] A diagnostic unit for diagnosing the functionality of the lidar measuring device enables a quick and reliable determination of the reliability of the measurements of a lidar measuring device. The diagnostic unit can take various forms. In particular, the diagnostic unit can comprise a computer chip, in particular a special chip, e.g., a 1oo2 architecture, such as an FPGA, a comparator, or even software running on the special chip.

[0024] Preferably, the diagnostic unit is configured to compare an expected predefined distance and an actually measured distance during a measurement within the calibration range and, based on the comparison, to diagnose the functionality of the lidar measuring device. This comparison allows the functionality of the lidar measuring device to be determined in a technically simple and, in particular, rapid manner.

[0025] It goes without saying that all common methods of determining distances can be applied to a lidar measurement. In particular, the distance can correspond to and / or be converted into a phase shift and / or a time of flight. It goes without saying that calibration can also be performed based on raw data. The received data does not necessarily have to be converted into a distance. For example, calibration can also be performed based on a ToF, based on ADC (analog-to-digital converter) entries, or the like. It is clear that a distance results from various parameters, such as a time of flight, a phase shift, etc., and in this respect, distance can preferably be used synonymously for the aforementioned quantities.

[0026] An analog-to-digital converter (ADC) is a device for converting analog input signals into digital data, which can then be further processed or stored. Other names and abbreviations include ADC (analog-to-digital converter), A / D (analog-to-digital converter), or A / D for short.

[0027] Furthermore, the coupling results in different distances between the optical unit and the laser light source, as well as the detector, during operation of the lidar measuring device. These different distances can be advantageously used for functional analysis or calibration. The relative positions of these points are preferably determined using a one-step code.

[0028] It is understood that the optical unit can be present in multiple configurations to enable a higher calibration frequency. Furthermore, the optical unit can also have a more complex structure and be suitable for multiple beam splitting. For simplicity, only a simple beam splitter is shown in the following embodiment.

[0029] Advantageously, the mechanical-optical unit comprises a first facet and a second facet configured to deflect an emitted laser light beam with respect to a polar angle. The external unit is forcibly rotatable in a predefined relationship to an angular change of a rotation of the deflection element. This forced rotation is preferably based on the coupling between the external unit and the deflection element. According to the predefined relationship, the external unit is preferably aligned offset relative to the internal unit by an angular dimension of a facet after a complete rotation of the internal unit.

[0030] Deflection by a facet specifically means that the laser light beam passes through the facet and is deflected in the process. It is understood that a backscattered laser light beam also experiences deflection when passing through the facet and can thus be directed toward the detector.

[0031] In other words, a laser light beam passes through a first facet during one complete rotation with respect to its azimuth angle and, after the rotation, passes through the second facet. The facets can cause an additional deflection of the laser light beams with respect to a polar angle. The vertical field of view of the lidar measuring device can be expanded. In particular, in combination with a deflection element, a main scanning plane can still be defined. The deflection element can compensate for the deflection by the corresponding facet or enable a larger zenith angle during the measurement. In particular, a one-step code, such as a Reed-Solomon code, can be used to determine the facet through which the light passes during the measurement. This allows the vertical direction, i.e., the polar angle and / or the azimuth angle, to be reliably calculated.

[0032] Particularly preferably, at least one of the laser light sources is designed to emit a laser light beam with a predefined clock rate and / or a predefined pulse length. Additionally, the lidar measuring unit corresponding to the laser light source is designed to validate a measurement based on a comparison of the predefined clock rate and / or the predefined pulse length of the emitted laser light beam with a clock rate and / or a pulse length of a received laser light beam. Preferably, the predefined clock rate or the predefined pulse length can be varied sequentially. Particularly preferably, the predefined clock rate or the predefined pulse length is varied randomly. This allows for a reliable determination of whether the received laser light beam corresponds to the emitted laser light beam. It can be ensured that deliberately externally induced interference signals can be reliably identified as interference signals.Reliable diagnosis and / or measurement can be performed using the lidar measuring device. It is understood that in embodiments with multiple laser light sources, all laser light sources can be configured in this way.

[0033] In a particularly advantageous embodiment, the lidar measuring device comprises a protective unit that forms an outer protective sheath of the lidar measuring device. The optical components, preferably the mechanical components, and particularly preferably all components and parts of the lidar measuring device as defined above, are accommodated within the protective unit. The protective unit is made of a material permeable to electromagnetic waves of a specific wavelength. This allows for the creation of a robust lidar measuring device that is protected from environmental influences and is particularly suitable for exposed locations.

[0034] Mechanical components are understood to mean, in particular, the components of the lidar measuring device that can move at least one optical component of the lidar measuring device.

[0035] Optical components are understood to mean, in particular, the components of the lidar measuring device that can generate, receive and / or manipulate a laser light beam.

[0036] In other words, the protection unit can be used to create a system consisting of a protection unit and a lidar measuring device as defined above, in which the lidar measuring device is accommodated in the protection unit. The invention is described and explained in more detail below using selected embodiments in conjunction with the accompanying drawings. They show:

[0037] Figure 1 is a schematic side view of a lidar measuring device;

[0038] Figure 2 is a schematic perspective view of a lidar measuring device with an outdoor unit;

[0039] Figure 3 is a schematic side view of a lidar measuring device with a deflection element during a measurement;

[0040] Figure 4 is a schematic side view of a lidar measuring device with a deflection element in a first position;

[0041] Figure 5 is a schematic side view of a lidar measuring device with a deflection element in a second position;

[0042] Figure 6 is a schematic perspective view of a lidar measuring device with an external unit with facets;

[0043] Figure 7 is a schematic side view of a lidar measuring device with facets; and

[0044] Figure 8 is a schematic plan view of a lidar measuring device with an optical unit.

[0045] Figure 1 shows a schematic side view of a lidar measuring device 10.

[0046] The lidar measuring device 10 has a first lidar measuring unit 12 with a first detector 14 and a first laser light source 13. The first lidar measuring unit 12 emits a first laser light beam 16 onto a first side of a deflection element 18.

[0047] The deflection element 18 has an inner base 22 which is rotatable via an electric motor 24 by means of a pinion 26, so that the deflection element 18 can be set in rotation.

[0048] The lidar measuring device 10 further comprises a second lidar measuring unit 12' with a second detector 14' and a second laser light source 13'.

[0049] The second lidar measuring unit 12' is configured to emit a second laser light beam 16'. Upon exiting the lidar measuring device 10, this second laser light beam is emitted substantially parallel to the first laser light beam 16 and impinges on a first light-guiding element 32. It is deflected by the first light-guiding element 32 onto a second light-guiding element 32, and impinges by the second light-guiding element 32 onto a second side of the deflecting element 18.

[0050] The second laser light beam 16' is emitted in the opposite direction to the first laser light beam 16 with respect to its azimuth angle. In other words, the first laser light beam 16 strikes the deflection element 18 from below, and the second laser light beam 16' is guided by the light-guiding elements 32 to the upper side of the deflection element 18. This allows for a fast scan in the plane defined by the laser light beams 16, 16'.

[0051] Figure 2 shows a schematic perspective view of a lidar measuring device with an external unit 20.

[0052] The same reference symbols refer to the same features and are not explained again.

[0053] The first lidar measuring unit, not shown for clarity, is arranged centrally with respect to the external unit 20 in the example shown and housed in a housing. Figure 2 shows the first laser light beam emerging from the housing onto the deflection element 18. The second laser light beam 16' extends off-center and past the housing, being guided via the two light-guiding elements 32 to a second side of the deflection element 18.

[0054] It is understood that the light-guiding elements 32 can be stationary, provided that the second lidar measuring unit 12' is stationary. It is further understood that the light-guiding elements 32 can be connected to the external unit 20 and rotate if the second lidar measuring unit 12' is also rotated.

[0055] Figure 3 shows a schematic side view of a lidar measuring device 10 with a deflection element 28.

[0056] In contrast to the embodiment shown in Figure 1, a deflection element 28 is arranged in the beam path of the first laser light beam 16 between the deflection element 18 and the first lidar measuring unit 12, the position of which can be varied by means of an actuator 30.

[0057] The deflection element 28 can be inserted into the beam path of the first laser light beam 16, so that the beam's angle is changed upon passing through the deflection element 28. This results in the polar angle of the first laser light beam 16 being changed after being deflected by the deflection element 18. The deflection element 28 can be, for example, a transparent plate, in particular a glass plate.

[0058] It is understood that the deflection element 28 can be aligned perpendicular to the emission direction of the first laser light beam 16 upon leaving the first lidar measuring unit 12. In this state, the first laser light beam 16 is not manipulated with regard to its polar angle. In other words, the first laser light beam 16 travels as if the deflection element 28 were not introduced into the beam path. It is understood that the deflection element 28 can also be removed from the beam path by means of the actuator 30. These positions are shown in dashed lines. The polar angle of the first laser light beam 16 can be influenced during measurement by means of the deflection element 28. The change in angle depends on the inclination of the deflection element 28. The inclination of the deflection element 28 can be adjusted by the actuator 30.

[0059] Figure 4 shows a lidar measuring device 10 with a deflection element 28 in a first position.

[0060] In the first position, the deflection element 28 is perpendicular to the emission direction of the first laser light beam 16. Here, the first laser light beam 16 penetrates the deflection element 28 and is not manipulated with respect to its vertical direction.

[0061] Figure 5 shows a schematic side view of the lidar measuring device 10 with a deflection element 28 in a second position.

[0062] In the second position, the deflection element 28 is tilted. It is aligned obliquely to the emission direction of the first laser light beam 16 as it exits the first lidar measuring unit 12.

[0063] As a result, the first laser light beam is refracted when entering the deflection element 28 and refracted again when exiting the deflection element 28, so that after passing the deflection element it continues to propagate at an angle different from the emission angle when exiting the first lidar measuring unit 12.

[0064] The first laser light beam 16 is manipulated in its polar direction after being deflected by the deflection element 18. Consequently, it is no longer deflected exactly horizontally. The deflection of the first laser light beam 16 with respect to its polar angle during measurement depends on the angle of inclination of the deflection element 28 and on the material and thickness of the deflection element 28 and can be precisely calculated using known physical laws.

[0065] Consequently, the resulting polar angle of the first laser light beam 16 can be calculated from the angular position that the actuator 30 sets for the deflection element 28 during measurement.

[0066] Figure 6 shows a Lidar measuring device 10 schematically in perspective during a measurement.

[0067] The first laser light source 13 emits the laser light beam 16 onto a deflection element 18. The deflection element 18 is designed to deflect the laser light beam 16 from a vertical direction into a horizontal direction in the embodiment shown.

[0068] After deflection in the horizontal direction, the laser light beam 16 passes a facet 34. The facet 34 can, for example, be designed as a prism and deflect the laser light beam 16 in the vertical direction as it passes through the facet 34.

[0069] The deflection element 18 is arranged on an inner base. The inner base is rotatable, so that the deflection element can also be rotated with the inner base and can thus deflect the laser light beam 16 with respect to its azimuth angle, i.e., in the horizontal direction.

[0070] For this purpose, the inner base is driven by an electric motor, which is connected to the inner base, for example, via a pinion.

[0071] It is understood that other connections, such as a traction mechanism, a magnetic coupling, or the like, are also conceivable. The facet 34 is arranged on an outer base 33, wherein the outer base 33 is coupled to the inner base and is forcibly rotated at a fixed rotational ratio to the rotational movement of the inner base.

[0072] In the measurement shown in Figure 6, the laser light beam hits the deflection element 18 and passes a facet 34, whereby the laser light beam is deflected downwards.

[0073] The fixed rotation ratio is preferably arranged such that the outdoor unit 20 is aligned offset by the angular dimension of the facet 34 after a complete rotation of the indoor unit.

[0074] A 360° scan in the azimuth direction can be performed using facet 34. Preferably, after this 360° scan in the azimuth direction, another facet is used for the next 360° scan in the azimuth direction due to the rotation ratio.

[0075] Figure 7 shows a schematic side view of a lidar measuring device with two facets 34. The embodiment shown in Figure ? is essentially identical to the embodiment shown in Figure 3.

[0076] In contrast to the embodiment shown in Figure 3, the embodiment according to Figure 7 comprises two facets 34, each of which is arranged on an external unit not shown.

[0077] The facets 34 form an outer surface of the lidar measuring device. Upon passing through the facets 34, the first laser light beam 16 or the second laser light beam 16' changes its polar angle. For this purpose, the facets have a parallelogram-shaped cross-section.

[0078] It is understood that each facet 34 can be configured to establish a different polar angle when passing through it than another facet 34. In particular, by combining it with the deflection element 28, an even wider polar angle range can be covered.

[0079] In addition, the deflection element 28 can also be used to compensate for the manipulation of the polar angle of a facet 34, so that at least one laser light beam can be measured in a predefined direction at high frequency.

[0080] It is understood that a further deflection element 28 can also be provided in the beam path of the second laser light beam 16'.

[0081] Figure 8 shows a schematic plan view of a lidar measuring device 10. For clarity, the second lidar measuring unit and the light guides have been omitted.

[0082] The lidar measuring device 10 has a planetary gear-like structure, so that the inner base, driven by the electric motor 24, rotates at a first angular velocity. For this purpose, the inner base has external gearing that meshes with a pinion 26 of the electric motor 24.

[0083] Furthermore, the external toothing meshes with an internal toothing of an external base. The external base has a mechanical-optical unit 35.

[0084] The lidar measuring device 10 according to Figure 8 comprises an optical unit 36 ​​configured to reflect at least a portion of the laser light beam 16 directly back to a detector. This allows the lidar measuring device 10 to be calibrated according to Figure 8. It is understood that the illustrated embodiment with only a single optical unit 36 ​​serves to provide a better overview, and embodiments with two or more optical units 36 are conceivable.

[0085] The distance between the optical unit 36 ​​and the detector is known or can be calculated. From this, the expected distance or expected travel time of the laser light beam 16 can be determined and compared with the measurement result. In particular, the expected intensity of the laser light beam 16 can also be compared with the current measurement.

[0086] It goes without saying that the second lidar measuring unit can also be measured in an analogous manner.

[0087] Wear of the detectors and the laser light sources as well as contamination or a malfunction of the lidar measuring device 10 can be detected.

[0088] It is understood that calibration can be carried out at different locations, wherein the relative positions of the external unit, the internal unit and the emission direction of the laser light beam 16 can preferably be determined by means of a one-step code, in particular by means of a Reed-Solomon code.

[0089] It is understood that the term "laser light beam" should be understood broadly. The term "laser light beam" preferably describes a path along which the laser light propagates. Pulsed lasers, in particular, can also be used.

[0090] In particular, it is conceivable for a laser light beam to have varying pulse lengths or a varying clock rate, so that a signal is imprinted on the laser light beam upon emission, which is then calibrated and verified by the diagnostic unit upon or after reception. This ensures that the detector has received the laser light emitted by the lidar measuring unit. After passing through the diagnostic unit, the detector signals can be forwarded to a final processing system.

[0091] Furthermore, a potentially faulty reflection of the laser light beam can be detected based on expected laser intensity values.

[0092] Angle information, which can originate, for example, from incremental sensors, as well as single-step coded positions of the lidar measuring unit and / or the deflection element and the external unit, can be compared against each other. This allows a redundant and precise angular position of the components relative to each other to be determined, enabling a more precise overall distance measurement and more accurate calibration of the lidar measuring device 10.

[0093] The invention has been comprehensively described and explained with reference to the drawings and the description. The description and explanation are to be understood as exemplary and not restrictive. The invention is not limited to the disclosed embodiments. Other embodiments or variations will become apparent to those skilled in the art upon use of the present invention and upon careful analysis of the drawings, the disclosure, and the following claims.

[0094] In the claims, the words "comprising" and "having" do not exclude the presence of further elements or steps. The undefined article "a" or "an" does not exclude the presence of a plurality. A single element or unit can perform the functions of several of the units recited in the claims. An element, unit, device, and system can be partially or completely implemented in hardware and / or software. The mere mention of some measures in several different dependent claims should not be understood to mean that a combination of these measures cannot also be used advantageously. A computer program can be stored / distributed on a non-volatile data carrier, for example on an optical memory or on a solid-state drive (SSD).A computer program may be distributed together with hardware and / or as part of hardware, for example, via the Internet or via wired or wireless communication systems. Reference signs in the patent claims are not to be construed as limiting.

[0095] 10 Lidar measuring device

[0096] 12 Lidar measuring unit

[0097] 13 Laser light source

[0098] 14 Detector

[0099] 16 laser light beam

[0100] 18 Deflection element

[0101] 20 outdoor unit

[0102] 22 inner base

[0103] 24 electric motor

[0104] 26 pinions

[0105] 28 Deflection element

[0106] 30 Actuator

[0107] 32 light guides

[0108] 33 External Base

[0109] 34 facets

[0110] 35 mechanical-optical unit

[0111] 36 optical unit

Claims

Patent claims 1. A lidar measuring device (10) for detecting an object, comprising: a first lidar measuring unit (12) comprising a first laser light source (13) for emitting a first laser light beam (16) and a first detector (14); a second lidar measuring unit (12') comprising a second laser light source (13') for emitting a second laser light beam (16') and a second detector (14'); a rotatable deflection element (18) configured to deflect the first laser light beam (16) and the second laser light beam (16') respectively with respect to a fixed polar angle and, based on a rotation of the deflection element (8), with respect to an azimuth angle, wherein: the deflection element (18) comprises a first side for deflecting the first laser light beam (16) in a first direction and a second side for deflecting the second laser light beam (16') in a second direction.

2. Lidar measuring device (10) according to the preceding claim, wherein the second side is opposite the first side; and the deflection element (18) is designed to deflect the first laser light beam (16) into an azimuth angle that is 180° different from the azimuth angle of the second laser light beam (16').

3. Lidar measuring device (10) according to one of the preceding claims, wherein the deflection element (18) comprises a double-sided mirror.

4. Lidar measuring device (10) according to one of the preceding claims, comprising a deflection element (28) which is designed to deflect the first laser light beam (16) and / or the second laser light beam (16') with respect to a polar angle.

5. Lidar measuring device (10) according to the preceding claim, wherein the deflection element (28) is designed to deflect the first laser light beam (16) at the same polar angle as the second laser light beam (16') in order to enable a fast scan; or the deflection element (28) is designed to deflect the first laser light beam (16) at a different polar angle from the second laser light beam (16') in order to enable a scan with a higher resolution.

6. Lidar measuring device (10) according to claim 4 or 5, wherein the deflection element (28) comprises a transparent plate arranged between a laser light source (13, 13') and the deflection element (18), wherein the transparent plate is tiltable by means of an actuator (30) in order to adjust an angle between the laser light beam (16, 16') of the laser light source (13, 13') and the transparent plate or to remove the transparent plate from the laser light beam (16, 16').

7. Lidar measuring device (10) according to one of the preceding claims, comprising: a rotatable external unit (20) with a mechanical-optical unit (35) permeable to electromagnetic waves of a specific wavelength; wherein the deflection element (18) and the external unit (20) are coupled.

8. Lidar measuring device (10) according to the preceding claim, wherein the coupling between the deflection element (18) and the external unit (20) is established by a non-positive and / or positive connection between an external base (33) of the external unit (20) and an internal base (22) of the deflection element (18).

9. Lidar measuring device (10) according to one of the preceding claims, with an optical unit (36) which is designed to reflect a laser light beam (16, 16') back to a detector (14, 14'); and a diagnostic unit for diagnosing a functionality of the lidar measuring device (10) based on a measurement of the laser light beam (16, 16') when the laser light beam (16, 16') strikes the optical unit (36) and is reflected back to the detector (14, 14'), and the detector signal during this measurement, wherein the optical unit (36) is preferably arranged on the mechanical-optical unit (35).

10. Lidar measuring device (10) according to one of claims 7 to 9, wherein the mechanical-optical unit (35) comprises a first facet (34) and a second facet (34) configured to deflect an emitted laser light beam (16, 16') with respect to a polar angle; the external unit (20) is forcibly rotatable in a predefined relationship to an angular change of a rotation of the deflection element (18); and according to the predefined ratio, the outdoor unit (20) is preferably aligned offset by one facet (34) with respect to the indoor unit (22) after a complete rotation of the indoor unit (22).

11. Lidar measuring device (10) according to one of the preceding claims, wherein at least one of the laser light sources (13, 13') is configured to emit a laser light beam (16, 16') with a predefined clock rate and / or a predefined pulse length; and the lidar measuring unit (12, 12') is configured to validate a measurement based on a comparison of the predefined clock rate and / or the predefined pulse length of the emitted laser light beam (16, 16') with a clock rate and / or a pulse length of a received laser light beam (16, 16').

12. Lidar measuring device (10) according to one of the preceding claims, with a protective unit which forms an outer protective sheath of the lidar measuring device (10), wherein the optical components, preferably the mechanical components and particularly preferably all components and parts of the lidar measuring device (10) according to one of the preceding claims are accommodated within the protective unit and the protective unit is made of a material which is permeable to electromagnetic waves of a certain wavelength.

13. Method for measuring by means of a lidar measuring device (10), preferably a lidar measuring device (10) according to one of the preceding claims, comprising the steps: Receiving an input signal of a first detector (14) of a first lidar measuring unit (12) and / or an input signal of a second detector (14') of a second lidar measuring unit (12'), each with information about a detector signal of a measurement and information about a deflection element (18) which is designed to deflect a first laser light beam (16) of the first lidar measuring unit (12) and / or a second laser light beam (16') of the second lidar measuring unit (12') in each case with respect to a fixed polar angle and based on a rotation of the deflection element (18) in each case with respect to an azimuth angle; Detecting an object; and Determining a distance and a direction with respect to the lidar measuring device (10) and the object based on the input signal.

14. Computer program product with program code for carrying out the Steps of the method according to the preceding claim when the program code is executed on a computer.

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