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 lidar measuring unit (12) having a laser light source (13) for emitting a laser light beam (16) and a detector (14); a rotatable outer unit (21) having a first facet (20) and a second facet (20) which are designed to deflect the laser light beam (16) emitted by the laser light source (16) with respect to its polar angle; wherein the lidar measuring unit (12) and the outer unit (21) are coupled to one another other such that the outer unit (21) performs a forced rotational movement based on a change in the azimuth angle of an emission direction of the laser light beam (16) of the lidar measuring unit (12).

Description

[0001] Lidar measuring device for detecting an object

[0002] The present invention relates to a lidar measuring device for detecting an object. The present invention further relates to a corresponding method and a computer program product.

[0003] 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).

[0004] 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.

[0005] 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, US 4,413,878 A, JP 2006 - 235 219 A, DE 25 34 695 A1, and DE 10 2019 134 192 A1.

[0006] The challenge is to expand the data collected by such a lidar system. In particular, measurements in more than one plane should be possible with minimal effort. 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.

[0007] This problem is solved by the subject matter of the subordinate claims.

[0008] The lidar measuring device for detecting an object comprises a lidar measuring unit, comprising a laser light source for emitting a laser light beam and a detector. Furthermore, the lidar measuring device comprises a rotatable external unit with a first facet and a second facet. In this context, a facet is understood to be an optical element that deflects laser light as it passes through. The facets are designed to deflect the laser light beam emitted by the laser light source with respect to its zenith angle or polar angle. Polar angle is understood to mean, in particular, a deflection in the vertical direction, with the lidar measuring device preferably scanning in a rotational horizontal direction. The lidar measuring unit and the external unit are coupled to one another, such that the external unit performs a forced rotational movement based on a change in the azimuth angle of an emission direction of the laser light beam of the lidar measuring unit.

[0009] Passing through a facet is understood in particular to mean that the laser light beam penetrates 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 onto the detector. 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 combination 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 designed according to the embodiments described for the device in the dependent claims.

[0010] By designing the external unit with a first facet and a second facet, the laser light beam can be deflected with respect to its polar angle in a technically simple manner. In other words, the vertical field of view of the lidar measuring unit can be expanded. Because the external unit is positively guided with respect to an emission direction in the horizontal direction, it can be achieved that for the same azimuth angle, different facets are traversed by the laser light beam during measurement. As a result, with each additional facet, a further vertical direction can be scanned by the lidar measuring device. It is understood that the lidar measuring device is preferably designed to measure with respect to an azimuth angle in a 360° field of view. The coupling and positively guided rotational movement enable, in particular, a precise determination of the facet through which the laser light beam passes during the current measurement.This makes it technically easy and reliable to determine in which vertical and horizontal direction, i.e. in which polar angle and azimuth angle, measurements are currently being taken.

[0011] An input signal is received with information about a detector signal of a measurement and information about a facet that the laser light beam hits during the measurement. A distance and a direction of the measurement are then determined based on the input signal. Consequently, a measurement direction is determined for each measurement and a distance of an object in the measurement direction. Preferably, the first facet deflects the laser light beam emitted by the laser light source with respect to a polar angle that is different from the polar angle of a deflection by the second facet. This allows the vertical field of view to be expanded in a technically simple manner. It is understood that more than two facets can be used. A person skilled in the art will recognize that with each additional facet, preferably a further vertical direction can be scanned.

[0012] Particularly preferably, the coupling makes any combination of the vertical and horizontal measuring directions possible, so that particularly preferably measurements can be taken in any of the available vertical directions for each horizontal measuring direction.

[0013] Particularly advantageously, according to the forced rotational movement, after a complete rotation of the emission direction of the laser light beam of the lidar measuring unit with respect to the azimuth angle, the external unit is offset by the angular range of one facet with respect to the azimuth angle of the emission direction after the complete rotation. This makes it possible to achieve a complete horizontal rotation of the measurement with the same vertical direction. The forced rotational movement therefore ensures that the laser light beam runs through the same facet in the horizontal direction for the entire angular range of the rotation. Preferably, the laser light beam runs from one end of the facet to the other end of the facet in the reference system of the facet. Once the laser light beam has reached the other end, the laser light beam has preferably exceeded an angle of 360° in the horizontal direction.A 360° azimuth scan can be performed using a facet. After this 360° azimuth scan, another facet is preferably used for the next 360° azimuth scan due to the forced rotation.

[0014] In a preferred embodiment, the lidar measuring device comprises an optical unit on the external unit, which is configured to reflect the laser light beam back to the detector. Furthermore, the lidar measuring device comprises a diagnostic unit for diagnosing the functionality of the 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 the detector, and a detector signal during this measurement. It is understood that both primary and secondary reflections from facets can also be used for calibration.

[0015] The accuracy of a lidar system's distance measurement can be verified by periodically splitting an outgoing laser light beam using an optical unit, for example, a beam splitter, and receiving it at a known distance from the receiver using known measurement methods. This creates a lidar system that is continuously calibrated and thus ensures reliable measurements. Furthermore, ambiguous measurements can be more easily interpreted or corrected, since a current relevant or calibration measurement is available for each measurement.

[0016] For this purpose, the lidar measuring device comprises a diagnostic unit which is designed to diagnose the functionality of the lidar measuring device based on the measurement of the laser light beam described above.

[0017] 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.

[0018] The optical unit is preferably designed as a beam splitter, so that in addition to the calibration or diagnostic measurement, a distance measurement can also be performed. 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 have various forms. In particular, the diagnostic unit can comprise a computer chip, in particular a special chip, e.g., a 1oo2 architecture, for example, an FPGA, a comparator, or even software executed on the special chip.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] The external unit preferably has an external base with a mechanical-optical unit having facets that is permeable to electromagnetic waves of a specific wavelength. Additionally, the lidar measuring unit has an internal base. The coupling between the lidar measuring unit and the external unit is established by a force-fitting and / or form-fitting connection between the external base and the internal base. In the simplest case, the mechanical-optical unit can be a transparent hollow cylinder arranged on an annular base. In particular, the external base can have internal teeth, and the internal base can have external teeth, which correspond, such that the coupling is established by the corresponding external and internal teeth.

[0023] It is understood that other couplings are also conceivable, for example, a coupling via a traction mechanism, a frictional coupling, or a magnetic coupling. In other embodiments, the coupling can also be implemented electronically, with a drive for the lidar measuring unit and / or the external unit being controlled in accordance with a drive for the other unit.

[0024] The optical-mechanical unit can provide protection for the lidar measuring unit, which is preferably arranged within the mechanical-optical unit. In a particularly preferred embodiment, the mechanical-optical unit can form a wear part that is easily replaceable in the event of damage. This can provide protection for sensitive components, particularly for sensitive optical and electronic components of the lidar measuring unit.

[0025] In an advantageous embodiment, the lidar measuring unit comprises a rotatable deflection element arranged within the external unit and comprising a first side for deflecting the laser light beam with respect to a fixed polar angle and for deflecting the laser light beam based on a rotation of the deflection element with respect to its azimuth angle. The forced rotational movement is arranged by a coupling between the deflection element and the external unit. The laser light source and the detector are preferably arranged outside the external unit, wherein the laser light strikes the deflection element and is thereby emitted into a plane. This allows the emission direction of the laser light to be varied by the deflection element. The entire lidar measuring unit does not necessarily have to be rotated. This allows part of the lidar measuring unit to be arranged outside the external unit, so that the external unit can be designed smaller.In particular, this allows the laser light source and the detector as well as at least a large part of the electronics of the lidar measuring unit to be arranged in a separate protected housing.

[0026] Particularly preferably, the lidar measuring device comprises a further lidar measuring unit, comprising a further laser light source for emitting a further laser light beam and a further detector. The deflection element comprises a second side for deflecting the further laser light beam, wherein the second side is preferably opposite the first side. Particularly preferably, the deflection element is designed to deflect the laser light beam at an azimuth angle that differs by 180° from the azimuth angle of the further laser light beam. This makes it technically easy to increase, in particular double, a sampling frequency of the lidar measuring device, wherein preferably a large part of the lidar measuring device is used twice and only an additional laser light source, an additional detector, and possibly minor modifications to the evaluation electronics are necessary.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] In other words, the protection unit can be used to create a system consisting of a protection unit and a lidar measuring device as previously defined, in which the lidar measuring device is accommodated in the protection unit.

[0031] In particular, in combination with different facets, a field of view can be expanded, allowing, for example, measurements to be taken using the first laser light beam in one plane and the second laser light beam in a second plane. It is understood that a sampling frequency can also be increased by emitting both laser light beams in the same plane. The two laser light beams are preferably deflected in opposite horizontal directions. The deflection element can, in particular, be a reflective and / or partially reflective element, such as an inclined mirror.

[0032] Preferably, a position of the external unit and the emission direction of the laser light source relative to each other, caused by the coupling, can be determined using a single-step code, in particular a Reed-Solomon code (RS code). This allows the position of the external unit and the emission direction of the laser light source relative to each other to be determined robustly. The alignment of the external unit and the emission direction of the laser light source relative to each other can be determined in a non-error-prone manner, so that the position of an optical unit for calibration and the facets can be determined robustly. Confidence in functional diagnostics and the measurement with the lidar measuring device can be increased.

[0033] Particularly preferably, the laser light source is designed to emit a laser light beam with a predefined clock rate and / or a predefined pulse length. Additionally, the diagnostic unit 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 induced external interference signals can be reliably identified as interference signals. A 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 designed in this way.

[0034] In the presented design for a lidar measuring device, individual components can be used in a simple design and other components, as described above, in a redundant manner. A drive unit, which in the simplest case can be an electric motor, for example, can be present in a single or double design. It is understood that the invention can also form a measuring lidar system without redundancy, with which preferably self-diagnosis of functionality and / or an expansion of the field of view is possible. A particularly preferred embodiment comprises a planetary gear-like arrangement, wherein the outer unit has an internal toothing on its base that engages with an external toothing on a base of the lidar measuring unit. Particularly preferably, the lidar measuring unit can be driven by means of an electric motor with a pinion.

[0035] In this configuration, the outdoor unit and the lidar measuring device have different angular velocities. Consequently, there is a difference in the rotational speed of the outdoor unit relative to the lidar measuring unit, so that ultimately, one facet is preferably used for deflection in the vertical direction for a complete 360° rotation around the azimuth angle.

[0036] Furthermore, different distances exist between the optical unit on the outdoor unit and the laser light source and 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.

[0037] The teaching disclosed here makes it possible to expand the vertical field of view of a lidar measuring device. Preferably, the vertical field of view can be increased progressively with an increasing number of facets. It is understood that the facet used for the current measurement is recorded and can be considered accordingly in the analysis.

[0038] Furthermore, continuous calibration capability at various angular positions of the external unit relative to the lidar measuring unit is possible. This is preferably enabled via an optical unit, which can be designed in particular as a beam splitter. The laser light beam emitted by the laser light source can strike this beam splitter and be split into two beam parts, with one part being used for distance measurement and the second part, i.e. in particular the reflection, being used for calibration. It is understood that this optical unit can be present multiple times to enable a higher calibration frequency. Furthermore, the optical unit can also have a more complex structure and be suitable for multiple beam splitting. In the following exemplary embodiment, only a simple beam splitter is shown for the sake of simplicity. In particular, it is conceivable to calibrate during each scan.For example, the optical unit could be a kind of cylinder formed by a collection of many vertical prisms.

[0039] It is understood that a deflection element may additionally be provided which is designed to deflect the laser light beam and / or the further laser light beam with respect to a polar angle.

[0040] The invention is described and explained in more detail below using selected embodiments in conjunction with the accompanying drawings. They show:

[0041] Figure 1 is a schematic side view of a lidar measuring device;

[0042] Figure 2 shows a schematic first perspective view of a lidar measuring device during a measurement;

[0043] Figure 3 shows a schematic first perspective view of a lidar measuring device during a further measurement;

[0044] Figure 4 is a schematic plan view of a lidar measuring device with an outdoor unit;

[0045] Figure 5 shows a schematic first perspective view of a lidar measuring device with a further lidar measuring unit;

[0046] Figure 6 is a schematic side view of the lidar measuring device according to Figure 5; Figure 7 is a schematic top view of a lidar measuring device with an optical unit; and

[0047] Figure 8 is a schematic side view of another lidar measuring device analogous to Figure 1.

[0048] Figure 1 shows a schematic side view of a lidar measuring device 10.

[0049] The lidar measuring device 10 comprises a lidar measuring unit 12 with a detector 14 and a laser light source 13. The laser light source 13 is configured to emit a laser light beam 16.

[0050] It is understood that laser light beam 16 is to 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.

[0051] The 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.

[0052] After deflection in the horizontal direction, the laser light beam 16 passes a facet 20. The facet 20 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 20.

[0053] The deflection element 18 is arranged on an inner base 22. The inner base 22 is rotatable, so that the deflection element 18 can also be rotated with the inner base 22 and can thus deflect the laser light beam 16 with respect to its azimuth angle, i.e., in the horizontal direction. For this purpose, the inner base 22 is driven by an electric motor 24, which is connected to the inner base 22 via a pinion 26. It is understood that other connections, such as a traction drive, a magnetic coupling, or the like, are also conceivable.

[0054] The facet 20 is arranged on an outer base (not shown for reasons of clarity), wherein the outer base is coupled to the inner base 22 and is forcibly rotated in a fixed rotational relationship to the rotational movement of the inner base 22.

[0055] Figure 2 shows a schematic perspective view of a lidar measuring device 10 during a measurement. During the measurement shown in Figure 2, the laser light beam 16 strikes the deflection element 18 and passes through a facet 20, deflecting the laser light beam 16 upward.

[0056] In the embodiment shown in Figure 2, six different facets are shown by way of example, with the facets being shown essentially identically for clarity. Only facet 20, through which the laser light beam 16 propagates during the measurement, is shown with a special geometry. In particular, facet 20 can have a cross-section in the shape of a parallelogram. The facets 20 are arranged on an external unit 21.

[0057] Figure 3 shows the lidar measuring device 10 during another measurement, analogous to Figure 2. Unlike the measurement shown in Figure 2, the laser light beam 16 is deflected downward as it passes the facet 20.

[0058] Figure 4 shows a schematic plan view of a lidar measuring device 10.

[0059] 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 an external toothing 30 that meshes with a pinion of the electric motor 24. Furthermore, the external toothing 30 meshes with an internal toothing of an outer base 28 of the outer unit. The outer unit has an opto-mechanical unit on which the facets 20 are arranged. In the embodiment shown, the outer unit comprises four facets 20, with a laser light beam 16 being deflected to the left in the drawing by the deflection element 18 and passing through a facet 20.

[0060] Figure 5 schematically shows a lidar measuring device 10 with two lidar measuring units. For clarity, the lidar measuring units have been omitted.

[0061] As described with reference to Figures 1 to 4, a first laser light beam 16 extends from a center of an indoor unit to the deflection element 18 and, in the embodiment shown, is deflected to the left of the deflection element 18.

[0062] A further laser light beam 16 of the further lidar measuring unit runs laterally past the inner base and is guided to a second side of the deflection element 18 by two light guide means 32, which can in particular be designed as mirrors.

[0063] Particularly preferably, the light guide means 32 can be designed analogously to the deflection element 18. The second or further laser light beam 16, emitted vertically upwards in Figure 5, is deflected twice via these two light guide means 32 and strikes a rear side of the deflection element 18. In this case, the further laser light beam 16 is deflected in particular in a direction opposite to the laser light beam 16 with regard to its azimuth angle. In other words, the azimuth angle of the laser light beam differs by 180° from the further laser light beam 16'. It is understood that the light guide means 32 can be stationary if the second lidar measuring unit is stationary. It is further understood that the light guide means 32 can be connected to the external unit and rotate if the second lidar measuring unit is also rotated.

[0064] In Figure 6, the lidar measuring device 10 according to Figure 5 is shown in an analogous manner to Figure 1.

[0065] The same reference symbols refer to the same features and are not explained again.

[0066] In contrast to the lidar measuring device 10 shown in Figure 1, the lidar measuring device 10 according to Figure 6 has a further lidar measuring unit 12' with a further detector 14' and a further laser light source 13' which, as described with reference to Figure 5, emits a further laser light beam 16' which is deflected by means of the light guide means 32 in such a way that it is projected onto a rear side of the deflection element 18 and is emitted in the opposite direction to the laser light beam 16 with respect to the azimuth angle.

[0067] Here, the first laser light beam 16 penetrates a different facet 20 than the further laser light beam 16', so that the two laser light beams 16, 16' are preferably emitted at different angles with respect to their vertical direction. This allows the lidar measuring device 10 shown in Figure 6 to quickly capture a wide vertical field of view.

[0068] It is understood that both laser light beams 16, 16' can also be deflected in the same direction with respect to their vertical angle, thereby doubling the scanning frequency. In other words, a faster scan can be enabled.

[0069] Figure 7 shows a lidar measuring device 10 similar to Figure 4. Unlike the lidar measuring device 10 shown in Figure 4, the lidar measuring device 10 according to Figure 7 includes an optical unit 34 designed to reflect at least a portion of the laser light beam 16 directly back to the detector. This allows the lidar measuring device 10 according to Figure 7 to be calibrated.

[0070] The distance between the optical unit 34 and the detector is known or can be calculated. From this, an expected travel time or an expected distance of the laser light beam 16 can be determined and compared with the measurement result. In particular, an expected intensity of the laser light beam 16 can also be compared with the current measurement.

[0071] From this, wear of the detector and the laser light source as well as contamination or a malfunction of the lidar measuring device 10 can be determined.

[0072] It is understood that calibration can be carried out at different locations, wherein the relative positions of the external unit, in particular of the optical unit 34, of 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.

[0073] Figure 8 shows a further lidar measuring device 10 similar to Figure 1. In contrast to the embodiment shown in Figure 1, the lidar measuring device 10 according to Figure 8 comprises a deflection element 36, which can be introduced into the beam path of the laser light beam 16 by means of an actuator 38.

[0074] The deflection element 36 can be inserted into the beam path of the laser light beam 16, so that the angle of the beam is changed upon passing through the deflection element 36. This results in the polar angle of the laser light beam 16 being changed after being deflected by the deflection element 18. The deflection element 36 can be, for example, a transparent plate, in particular a glass plate.

[0075] It is understood that the deflection element 36 can be oriented perpendicular to the emission direction of the laser light beam 16 upon exiting the lidar measurement unit 12. In this state, the first laser light beam 16 is not manipulated with respect to its polar angle. In other words, the laser light beam 16 travels as if the deflection element 36 were not inserted into the beam path.

[0076] It is understood that the deflection element 36 can also be removed from the beam path using the actuator 38. These positions are shown in dashed lines. The polar angle of the laser light beam 16 can be influenced during measurement using the deflection element 36. The angle change depends on the inclination of the deflection element 36. The inclination of the deflection element 36 can be adjusted using the actuator 38.

[0077] In the example shown, the laser light beam 16, after being deflected by the deflection element 18, passes through a facet 20. This allows the vertical field of view to be expanded. It goes without saying that measurements can also be taken without the facet 20.

[0078] A person skilled in the art will recognize that the vertical measuring direction of the lidar measuring device 10 can be manipulated both by means of the deflection element 36 and by means of the facet 20.

[0079] 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 impressed 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 12. After passing through the diagnostic unit, the detector signals can be forwarded to a final processing system of the lidar measuring unit 12 or the lidar measuring device 10.

[0080] Furthermore, a potentially faulty reflection of the laser light beam can be detected based on expected laser intensity values.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] Reference symbol

[0085] 10 Lidar measuring device

[0086] 12 Lidar measuring unit

[0087] 13 Laser light source

[0088] 14 Detector

[0089] 16 laser light beam

[0090] 18 Deflection element

[0091] 20 facets

[0092] 21 Outdoor unit

[0093] 22 inner base

[0094] 24 electric motor

[0095] 26 pinions

[0096] 28 External Base

[0097] 30 external gearing

[0098] 32 light guides

[0099] 34 optical unit

[0100] 36 Deflection element

[0101] 38 Actors

Claims

Patent claims 1. A lidar measuring device (10) for detecting an object, comprising: a lidar measuring unit (12) comprising a laser light source (13) for emitting a laser light beam (16) and a detector (14); a rotatable external unit (21) having a first facet (20) and a second facet (20) which are designed to deflect the laser light beam (16) emitted by the laser light source (16) with respect to its polar angle upon penetrating the facet (20); wherein the lidar measuring unit (12) and the external unit (21) are coupled to one another such that the external unit (21) performs a forced rotational movement based on a change in an azimuth angle of an emission direction of the laser light beam (16) of the lidar measuring unit (12).

2. Lidar measuring device (10) according to one of the preceding claims, wherein the first facet (20) deflects the laser light beam (16) emitted by the laser light source (13) with respect to a polar angle which is different from the polar angle of a deflection by the second facet (20).

3. Lidar measuring device (10) according to one of the preceding claims, wherein according to the forced rotational movement after a complete rotation of the emission direction of the laser light beam (16) of the lidar measuring unit (12) with respect to the azimuth angle, the external unit (21) is aligned offset by one facet (20) with respect to the azimuth angle of the emission direction after the complete rotation.

4. Lidar measuring device (10) according to one of the preceding claims, with an optical unit (34) on the external unit (21) which is is designed to reflect the laser light beam (16) back to the detector (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) when the laser light beam (16) strikes the optical unit (34) and is reflected back to the detector (14), and a detector signal during this measurement.

5. Lidar measuring device (10) according to one of the preceding claims, wherein the external unit (21) has an external base (28) and a mechanical-optical unit with the facets (20) that is transparent to electromagnetic waves of a specific wavelength; the lidar measuring unit (12) has an internal base (22); and the lidar measuring unit (12) and the external unit (21) are coupled by a force-fitting and / or form-fitting connection between the external base (28) and the internal base (22).

6. Lidar measuring device (10) according to claim 5, wherein the lidar measuring unit (12) comprises a rotatable deflection element (18) arranged within the external unit (21), and a first side for deflecting the laser light beam (16) with respect to a fixed polar angle and based on a rotation of the deflection element (18) with respect to an azimuth angle; the forced rotational movement is arranged by a coupling between the deflection element (18) and the external unit (21); and the laser light source (13) and the detector (14) are preferably arranged outside the external unit (21).

7. Lidar measuring device (10) according to the preceding claim, with a further lidar measuring unit (12'), comprising a further laser light source (13') for emitting a further laser light beam (16') and a further detector (14'), wherein the deflection element (18) comprises a second side for deflecting the further laser light beam (16'); wherein the second side is preferably opposite the first side; and the deflection element (18) is particularly preferably designed to deflect the laser light beam (16) into an azimuth angle that is 180° different from the azimuth angle of the further laser light beam (16').

8. Lidar measuring device (10) according to one of the preceding claims, wherein the laser light source (13), and preferably the further laser light source (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) 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').

9. 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.

10. Method for measuring by means of a lidar measuring device (10), comprising the steps: Receiving an input signal with information about a detector signal of a measurement and information about a facet (20) onto which the laser light beam (16, 16') strikes and penetrates during the measurement; Determine a distance and direction of measurement based on the input signal.

11. 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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