Verification of laser scanner operability

Abstract

According to a method for verifying the functionality of a laser scanner (2b) comprising a housing having a light-transmitting window (5), a transmitting unit (6) inside the housing (4), a deflection unit (10), and a detector unit (7) inside the housing (4), at least one test signal (15) is transmitted by the transmitting unit (6) during the test phase. The deflection unit (10) is oriented in such a way that the at least one test signal (15) does not face the window (5). A component (15') of the at least one test signal (15) is detected by the detector unit (7), and at least two detector signals are generated based on this detection. A computing unit (2a) checks the pulse width for each detector signal and calculates the sum of the pulse widths. The operability of the transmitting unit (6) and / or the detector unit (7) is verified based on the sum.

Description

Technology Field

[0001] The present invention relates to a method for checking the function of a laser scanner comprising a housing having a light-transmitting window, a transmitter emitting a laser signal arranged within the housing, a movable deflection unit deflecting the laser signal, and a detector unit arranged within the housing, wherein during a test phase, at least one test signal is transmitted by the transmitter unit, and the deflection unit is aligned with respect to the transmitter unit during the test phase so that at least one test signal is not directed toward the window. The present invention also relates to a laser scanner device having a computing unit and a laser scanner, an automobile having a laser scanner device, and a computer program product. Background Technology

[0002] Lidar systems can be installed in vehicles to implement various functions of electric vehicle guidance systems or driver assistance systems. These functions include distance measurement, distance control algorithms, lane keeping assistance, and object tracking.

[0003] A known design of a LiDAR system is a so-called laser scanner, in which a laser beam is deflected by a deflection unit to enable different deflection angles of the laser scanner. The emitted laser beam may be partially reflected or scattered from the surroundings, and the scattered or reflected components may, in turn, partially strike the laser scanner, specifically the detector unit of the laser scanner, which can generate a corresponding detector signal based on the detected components. The transmitter unit of the laser scanner includes one or more laser light sources, and the detector unit includes one or more optical detectors, such as photodiodes.

[0004] In principle, the maximum range of a laser scanner is very important, especially in the automotive sector. Functionality, and specifically the maximum range of a laser scanner, can be affected by contamination, for example, of the light source or optical detector. For instance, contamination can be traced back to dust particles generated during the manufacturing process. These dust particles can partially cover the light source or optical detector, thereby reducing the laser scanner's range. In principle, contamination can be identified, for instance, through testing at the end of the manufacturing process. However, contamination may occur only after the test, or contamination that was present prior to the test may simply cover the light source or optical detector afterward.

[0005] Reference DE 10 2018 110 566 A1 describes a method for checking the function of a laser scanner. In this case, an optical signal is transmitted by the transmitter of the laser scanner, and a rotary or swivel deflection mirror unit is aligned so that the optical signal from the transmitter does not face the window of the laser scanner's housing. The optical signal scattered within the housing is received by a receiver and compared with a reference intensity distribution. Based on the comparison result, a notification regarding the function of the laser scanner is optionally generated.

[0006] The disadvantage of this method is that the reference intensity distribution is generally temperature-dependent, and as a result, different reference intensity distributions must be stored for different temperatures.

[0007] Against this background, the objective of the present invention is to specify an improved concept for checking the functionality of a laser scanner that is more robust with respect to temperature fluctuations.

[0008] This objective is achieved by the subject matter of each independent claim. Advantageous developments and preferred embodiments are the subject matter of the dependent claims.

[0009] The improved concept is based on the idea that a detector unit determines the pulse width for each corresponding detector signal in a laser scanner comprising at least two optical detectors, and determines the sum of the pulse widths to check the function.

[0010] According to the improved concept, a method for checking the function of a laser scanner is specified. The laser scanner includes a housing having a light-transmitting window and a sensor emitting a laser signal arranged within the housing. The laser scanner also includes a movable deflection unit that deflects the laser signal and a detector unit arranged within the housing having at least two photodetectors. According to this method, at least one test signal is transmitted by a transmitter unit during the test phase. During the test phase, the deflection unit is aligned with respect to the transmitter unit, particularly by the control unit of the laser scanner, so that at least one test signal is not directed toward the window, particularly by the deflection unit. A component of at least one test signal, particularly a reflection and / or scattering component, is recorded by at least two optical detectors, and at least two detector signals are generated by at least two optical detectors based on the recorded component. A pulse width is determined for each of the at least two detector signals by a computing unit, particularly by the computing unit of the laser scanner or by a computing unit coupled to the laser scanner, and the determined pulse widths, particularly the sum of all determined pulse widths, are calculated. The functions of the transmitter unit and / or detector unit are checked, in particular, based on the sum by the computing unit.

[0011] Here and below, the term "light" may be understood to include electromagnetic waves in the visible light, infrared, and / or ultraviolet regions. Accordingly, the term "optics" may also be understood to relate to light in this sense. Laser signals and test signals are preferably equivalent to light in the infrared region.

[0012] The transparent window of the housing is transparent, in particular, to light that may be emitted by the transmitter unit, especially in the form of a laser signal or a test signal. For example, apart from the window, the housing may be opaque.

[0013] Each of the laser signal and at least one test signal corresponds to a laser signal that may be emitted by one or more light sources of the transmitter unit, in particular a laser light source, for example, a laser diode. In particular, at least one test signal can be viewed as a special case of the laser signal, specifically a type of laser signal emitted during the test phase. Nevertheless, the test signal may be generated and emitted with a specially adapted spectral configuration or structure, or with other configurations or structures that may differ from other laser signals generated and emitted outside the test phase. However, this is not mandatory.

[0014] Detector units, in particular at least two optical detectors, are configured to detect reflected or scattered components of a laser signal and at least one test signal. When a laser signal is emitted around the housing through a light-transmitting window, components of the laser signal that are reflected or scattered, for example, outside the laser scanner or housing, may re-enter the housing and subsequently be detected. In the case of at least one test signal, components of the at least one test signal that may be reflected and / or scattered multiple times within the housing are detected by at least two optical detectors. In particular, at least one test signal does not essentially leave the housing of the laser scanner and, as a result, does not face the window.

[0015] At least one test signal not directed toward the window can be understood, in particular, based on an understanding of ray-optics or geometric optics.

[0016] Each of the at least two optical detectors generates an associated detector signal of at least two detector signals, particularly based on the component recorded by each optical detector. Depending on a specific embodiment of the laser scanner, the at least two optical detectors may be configured differently. The at least two optical detectors preferably each include a photodiode, for example, an avalanche photodiode (APD). Thus, the time profile of one of the detector signals reflects the time profile of a number of photons striking the corresponding optically active surface of each optical detector.

[0017] In particular, the detector signal contains a signal pulse, also known as an echo. Therefore, the pulse width of the detector signal corresponds specifically to the pulse width of that signal pulse. In this case, the pulse width is provided by a time interval in which the amplitude of the corresponding detector signal is assumed to be higher than a predefined threshold value. This pulse width is also referred to as the echo pulse width (EPW).

[0018] Checking the function of the transmitter unit and / or detector unit can be understood in relation to the sum of pulse widths used to check whether there are limitations, particularly in comparison to normal operation, unlimited operation, or unlimited function of the transmitter unit and / or detector unit.

[0019] In particular, the number of photons striking the active surface of the optical detector affects the pulse shape of the corresponding signal pulse, thereby influencing the pulse width. If the pulse width under reproducible conditions differs from what is expected for normal or unlimited operation, as given in the test phase, it can be inferred that the function of the transmitter unit and / or detector unit is limited. This may be caused, in particular, by a light source of either the transmitter unit or the optical detector, specifically by partial or full coverage of the active surface of one of the optical detectors.

[0020] The improved concept utilizes the finding that the sum of pulse widths for the predefined detector sensitivity of the entire detector unit remains at least nearly invariant with respect to temperature fluctuations, even when individual optical detectors have different temperature characteristics—for example, when the relationship between the temperature and voltage at which the optical detector must operate to obtain a certain sensitivity, particularly the reverse voltage, is not exactly the same for every optical detector. As an example, these different temperature characteristics can be traced back to the slightly different sizes of the active surfaces of each optical detector. Then, although individual pulse widths may necessarily change in the event of temperature fluctuations, the sum of all pulse widths remains at least nearly constant because a potentially smaller pulse width of one of the detectors is compensated by the corresponding larger pulse width of the remaining detectors. It was found that this holds true even when at least one of two optical detectors has significantly different temperature characteristics from the other. If the calculated sum of pulse widths now deviates from an expected value that can be determined, for example, within a calibration range, this indicates, for example, limited capability of one of the optical detectors or the light source of the transmitter unit due to contamination. Additionally, for unlimited functions, the magnitude of the deviation between the expected value and the sum value can allow for statements regarding the severity of function limitations or contamination. As coverage increases, fewer photons are detected by the corresponding optical detector, resulting in smaller pulse widths and consequently, a larger deviation in the sum.

[0021] In addition, as a result of using the test signal in the described manner, the possible influence of ambient light is reduced or virtually eliminated.

[0022] According to at least one embodiment of the method according to the improved concept, the sum is compared with a reference value given by a computing unit, and the function of the transmitter unit and / or detector unit is checked based on the comparison result.

[0023] In this case, the reference value may be, in particular, the sum of the pulse widths of the previous time during calibration, for example. A deviation from the reference value in the sum, in particular a deviation exceeding a predefined tolerance value, indicates a limited capability of at least two optical detectors or light sources.

[0024] In various embodiments, the reference value may also be updated, for example, when the laser scanner is activated or deactivated, or periodically. In particular, if it is determined that there is no serious impairment to the function of the transmitter unit and / or detector unit, the sum of the calculated pulse widths may be defined and stored as a new reference value. This allows for compensation for the effects of normal aging of the components, particularly the optical detector.

[0025] According to at least one embodiment, each of at least two optical detectors includes a photodiode, e.g., an avalanche photodiode (APD), which is operated in reverse by a control unit of a laser scanner in particular. The reverse voltage for operating the photodiode is controlled by the control unit in particular during a test phase to set a predefined detector sensitivity of the detector unit and, in particular, to keep it constant.

[0026] Detector sensitivity is, in particular, the joint sensitivity of all optical detectors among at least two optical detectors. For example, this sensitivity may be determined by the total dark current of at least two optical detectors and / or, in particular for an APD, by the joint multiplication factor of at least two optical detectors. In this context, the multiplication factor specifies, in particular, the number of charge carriers generated per photon detected, for example, on average by at least two optical detectors.

[0027] In this case, at least two optical detectors all operate with the same reverse voltage.

[0028] According to at least one embodiment, the setpoint value for closed-loop control of the reverse voltage is determined according to the detector sensitivity, particularly based on calibration data given by the control unit.

[0029] For example, calibration data can describe a relationship between temperature, e.g., the ambient temperature of at least two optical detectors or the heat sink temperature of at least two optical detectors, and the reverse voltage required to acquire detector sensitivity. In particular, this relationship may be at least approximately linear. The relationship may be stored in a storage element of a computing unit or control unit, for example, in the form of a conversion table or a lookup table.

[0030] For calibration purposes, for example, detector sensitivity, or the corresponding dark current, or the corresponding multiplication factor may be specified. Then, the corresponding reverse voltage required to obtain the detector sensitivity, dark current, or multiplication factor may be determined at two or more temperatures. The reverse voltage for additional temperatures may be determined by linear interpolation and / or extrapolation.

[0031] According to the improved concept, a laser scanner device comprising a computing unit and a laser scanner is also specified. The laser scanner comprises a housing having a light-transmitting window and a transmitter unit emitting a laser signal arranged within the housing. The laser scanner comprises a movable deflection unit and a control unit for deflecting the laser signal, and a detector unit arranged within the housing having two or more optical detectors. The control unit is configured to drive the transmitter unit to transmit at least one test signal during a test phase. The control unit is also configured to drive the deflection unit in such a way that the deflection unit is aligned with the transmitter unit during the test phase so that at least one test signal is not directed toward the window. At least two optical detectors are configured to record the reflected and / or scattered components of at least one test signal and to generate at least two detector signals based on the detected components. The computing unit is configured to determine the pulse width for each of the at least two detector signals and to calculate the sum of the pulse widths. The computing unit is configured to check the function of the transmitter unit and / or detector unit based on the sum.

[0032] In this case, the computing unit may be part of the laser scanner or provided separately. If the laser scanner device is provided for use inside or in a vehicle, the computing unit may be implemented, for example, as the vehicle's electronic controller. The control unit may optionally be part of the computing unit. In particular, the described functions or operations of the computing unit may be performed by the control unit in various embodiments, and vice versa.

[0033] According to at least one embodiment of a laser scanner device, the deflection unit includes a rotary or swivel mirror or a microelectromechanical mirror system, that is, a mirror designed as a microelectromechanical system (MEMS).

[0034] In particular, the control unit can drive the deflection unit during the test phase in such a way that the test signal correspondingly emitted by the transmitter unit does not collide with the reflective surface of the deflection unit, particularly the mirror, or is deflected by the reflective surface into an area within the housing that does not correspond to the window.

[0035] In various embodiments, the pivoting or rotating mirror comprises a mirror body that may have a substantially rectangular shape, in particular, and a reflective surface is located on one side of the rectangular shape. In various configurations, an additional reflective surface may be arranged on the side of the rectangular shape opposite to the reflective surface. The mirror body is mounted to be rotatable or pivotable about a rotation axis that passes particularly through two additional opposing sides of the rectangular shape. Thus, the remaining two sides of the rectangular shape that do not correspond to the side through which the rotation axis passes or the reflective surface may be, for example, referred to as end faces.

[0036] In various embodiments, the control unit is configured to drive the deflection unit during the test phase in such a way that the emitted test signal strikes one of the end faces.

[0037] According to at least one embodiment, each of at least two optical detectors includes a photodiode, in particular an APD. A control unit is configured to control a reverse voltage to operate the photodiode during a test phase to operate the photodiode in reverse and to set a predefined detector sensitivity of the detector unit.

[0038] According to at least one embodiment, the control unit is configured to operate all photodiodes of at least two optical detectors using the same controlled reverse voltage in each case during the test phase.

[0039] According to at least one embodiment, the control unit is configured to determine a setpoint value for closed-loop control of reverse voltage depending on detector sensitivity based on given calibration data.

[0040] Further embodiments of the laser scanner device directly follow different configurations of proportions according to the improved concept, and vice versa. In particular, the laser scanner device according to the improved concept may be configured or programmed to perform a method according to the improved concept, or the laser scanner device performs such a method.

[0041] According to the improved concept, an automobile including an embodiment of a laser scanner device according to the improved concept is also specified.

[0042] A computer program having instructions is also specified according to the improved concept. When an instruction or computer program is executed by a laser scanner device according to the improved concept, the instruction causes the laser scanner device to perform a method according to the improved concept.

[0043] According to the improved concept, a computer-readable storage medium for storing a computer program according to the improved concept is also specified.

[0044] Computer programs and computer-readable storage media according to the improved concept can be considered as respective computer program products having instructions.

[0045] Further features of the present invention are set forth in the claims, drawings, and description of the drawings. The features and combinations of features described above and the features and combinations of features to be described below, which are depicted in the description of the drawings and / or only in the drawings, may be included in the improved concept in combinations other than those specified in each case. Accordingly, embodiments of the improved concept that may arise from and be generated from embodiments described by individual combinations of features, even if not explicitly shown and described in the drawings, are included and disclosed. Accordingly, embodiments and combinations of features that do not have all the features of the original claims are included and disclosed, in particular. Furthermore, embodiments and combinations of features other than those specified in the cross-reference of the claims, or combinations of embodiments and features different from such, are included and disclosed. Brief explanation of the drawing

[0046] In the drawing, FIG. 1 illustrates a schematic diagram of an automobile having an exemplary embodiment of a laser scanner device according to an improved concept. FIG. 2 illustrates a schematic diagram of an additional exemplary embodiment of a laser scanner device according to an improved concept. FIG. 3 illustrates a schematic diagram of a transmitter unit of an additional exemplary embodiment of a laser scanner device according to an improved concept. FIG. 4 schematically illustrates part of an additional exemplary embodiment of a laser scanner device according to an improved concept in the scanning step. FIG. 5 illustrates a schematic diagram of an additional exemplary embodiment of a laser scanner device according to a concept improved during the testing phase. Specific details for implementing the invention

[0047] FIG. 1 schematically illustrates an exemplary embodiment of a vehicle (1) according to an improved concept. The vehicle (1) includes a laser scanner device (2) according to an exemplary embodiment according to an improved concept. The laser scanner device (2) emits a laser signal (9) around the vehicle (1) and can detect a component (9') of the laser signal reflected by a surrounding object (3). The laser scanner device (2) can determine the position and / or distance of the object (3) from the laser scanner device (2) based on the detected reflected component (9'). This can be implemented, for example, based on the time-of-flight (TOF) measurement concept.

[0048] FIG. 2 schematically illustrates a block diagram of an exemplary embodiment of a laser scanner device (2), for example, a laser scanner device (2) of the vehicle (1) of FIG. 1. The laser scanner device (2) comprises a laser scanner (2b) and a computing unit (2a) connected to the laser scanner (2b) and which may be, for example, in the form of an electronic controller of the vehicle (1). The laser scanner (2b) comprises a housing (4) having a light-transmitting window (5) and a transmitter unit (6) for emitting a laser signal (9) arranged within the housing (4), the laser signal being emitted through the light-transmitting window (5). The laser scanner (2b) comprises a control unit (8) connected to the computing unit (2a) and the transmitter unit (6) to drive the transmitter unit (6) to emit the laser signal (9). The laser scanner (2b) also comprises a detector unit (7) having at least two optical detectors, specifically designed as photodiodes, for example, APDs. The transmitter unit (6) includes at least one light source, in particular a laser source, for example, at least one infrared laser diode.

[0049] The detector unit (7) can detect the reflected component (9') of the laser signal (9), and based on this, each of at least two optical detectors can generate a corresponding detector signal and transmit it to the control unit (8) and / or computer unit (2a).

[0050] The laser scanner (2b) also includes a deflection unit that may have a mirror (10) rotatably mounted around a rotation axis (11), for example. In FIG. 2, the rotation axis (11) is perpendicular to the plane of the drawing. The deflection unit is likewise connected to a control unit (8), and the control unit (8) can drive the deflection unit so that the mirror (10) rotates around the rotation axis (11) accordingly. Thus, the emission angle of the laser signal (9) can be changed by the rotation of the mirror (10). For example, a receiving path for the reflected component (9') of the laser signal (9) reflected by an object (3) leads through the mirror (10) to the active surface of a detector unit (7), specifically one of the optical detectors. The reflected component (9') is then recorded by the corresponding optical detector, and thus by rotating the mirror (10) around the rotation axis (11), each optical detector can detect the reflected component (9') of the laser signal (9) incident from different directions. The instantaneous position of the mirror (10) can be determined, for example, through a rotary encoder (not shown) coupled to a rotation axis (11) or a corresponding shaft.

[0051] Since the instantaneous position of the mirror (10) is known at every point in time, for example, a set of scanning points, also called a point cloud, can be generated by the temporal order of the detected reflection components (9'). In this case, a subset of scanning points or a point cloud is generated by each optical detector. A subset of scanning points generated by one of the optical detectors can also be called the position of the scanning points.

[0052] FIG. 3 schematically illustrates the transmitter unit (6), laser signal (9), and object (3) of the laser scanner (2b) of FIG. 2. The upper drawing of FIG. 3 corresponds, for example, to a side view, that is, a view seen in a direction perpendicular to the axis of rotation of the mirror (10). The lower drawing of FIG. 3 corresponds, for example, to a top view of the transmitter unit (6), that is, a view seen in a direction parallel to the axis of rotation of the mirror (10). As is evident from the drawings of FIG. 3, each beam extension of the laser signal (9) may differ from one another in different planes.

[0053] FIG. 4 schematically illustrates once again the detector unit (7) and mirror (10) of the laser scanner (2b) of FIG. 2, with the receiving path of the reflected component (9') shown. Optionally, the laser scanner (2b) may have a lens array (14) for beam guiding arranged in the receiving path for the reflected component (9').

[0054] The example in FIG. 4 illustrates four optical detectors (7a, 7b, 7c, 7d) of a detector unit (7), which are arranged linearly next to each other, for example. For example, the transmitter unit (6) may have two or more light sources, and two or more of the optical detectors (7a, 7b, 7c, 7d) are assigned to each light source.

[0055] In FIG. 4, the mirror (10) has a roughly or substantially rectangular mirror body. However, the sides of the mirror body do not necessarily have to be flat and may be curved, for example. The mirror (10) has two opposing reflective surfaces (12a, 12b) arranged parallel to the axis of rotation (11), for example. Two non-reflective end surfaces (13a, 13b) of the mirror body are arranged perpendicular to the reflective surfaces (12a, 12b) and likewise parallel to the axis of rotation (11).

[0056] In FIG. 4, the laser scanner (2b) is shown, for example, during the scanning phase. The transmitter unit (6) emits a laser signal (9) that is incident on one of the reflective surfaces (12a, 12b) and adjusted into a window (5) by a deflection unit so that the laser signal can leave the housing (4), as also schematically illustrated in FIG. 2. The reflected component (9') is likewise incident on the reflective surfaces (12a, 12b) and is deflected accordingly to the detector unit (7).

[0057] In FIG. 5, a laser scanner (2b) is shown during the test phase. During the test phase, the mirror (10) is aligned with the transmitter unit (6) in such a way that the test signal (15) emitted during the test phase is incident on one of the end surfaces (13a, 13b) and is not adjusted in the direction of the window (5) accordingly, but instead is reflected or scattered multiple times within the housing (4) without change. Accordingly, the component (15') of the test signal (15) that is reflected and scattered multiple times is incident on the active surface of the optical detectors (7a, 7b, 7c, 7d) in turn, and based on this, a corresponding detector signal is generated and transmitted to the computing unit. Then, the computing unit (2a) determines a corresponding pulse width, which may also be referred to as an echo pulse width (EPW), for each detector signal.

[0058] Additionally, the computing unit (2a) determines the sum of all determined pulse widths and compares the sum with a specified reference value determined, for example, within the calibration range of the laser scanner (2b). If the sum deviates from the reference value by more than the given tolerance value, it can be inferred that the function of one of the optical detectors (7a, 7b, 7c, 7d) or one of the light sources is limited, for example, by the amount of particle contamination. In this case, the computing unit (2a) may output, for example, a warning or error message.

[0059] As described, particularly in relation to drawings, the improved concept makes it possible to overcome functional limitations of a laser scanner caused by contamination of the laser scanner's light source or optical detector with greater reliability and / or robustness with respect to temperature fluctuations. To this end, the invariance of the characteristic sum of pulse widths is utilized.

Claims

Claim 1 A method for checking the function of a laser scanner (2b) comprises, wherein the laser scanner (2b) includes a housing (4) having a light-transmitting window (5), a transmitter unit (6) that emits a laser signal (9) arranged within the housing (4), a movable deflection unit (10) that deflects the laser signal (9), and a detector unit (7) arranged within the housing (4). According to the method, at least one test signal (15) is transmitted by the transmitter unit (6) during a test phase, and the deflection unit (10) is aligned with the transmitter unit (6) during the test phase so that the at least one test signal (15) does not face the window (5). A component (15') of the at least one test signal (15) is recorded by at least two optical detectors (7a, 7b, 7c, 7d) of the detector unit (7), and at least two detector signals are generated based on the detected component (15'). The at least two detector signals A method characterized in that, for each, a pulse width is determined by a computing unit (2a) and the sum of the determined pulse widths is calculated, and the function of the transmitter unit (6) and / or detector unit (7) is checked based on the sum. Claim 2 A method according to claim 1, wherein the sum is compared with a reference value given by the computing unit (2a), and the function of the transmitter unit (6) and / or detector unit (7) is checked based on the result of the comparison. Claim 3 A method according to claim 1, wherein each of the at least two optical detectors (7a, 7b, 7c, 7d) includes a photodiode that operates under reverse bias, and wherein a reverse voltage is controlled to operate the photodiode during the test step to set a predefined detector sensitivity of the detector unit (7). Claim 4 A method according to claim 3, characterized in that all photodiodes of the at least two optical detectors (7a, 7b, 7c, 7d) are each operated at the same controlled reverse voltage during the test step. Claim 5 A method according to claim 3, characterized in that the set point value for closed-loop control of the reverse voltage is determined according to the detector sensitivity based on given calibration data. Claim 6 A laser scanner device having a computing unit (2a) and a laser scanner (2b), wherein the laser scanner (2b) comprises a housing (4) having a light-transmitting window (5), a transmitter unit (6) emitting a laser signal (9) arranged within the housing (4), a control unit (8), a movable deflection unit (10) deflecting the laser signal (9), and a detector unit (7) arranged within the housing (4); wherein the control unit (8) drives the transmitter unit (6) so that the transmitter unit (6) transmits at least one test signal (15) during a test phase, and drives the deflection unit (10) in such a manner that the deflection unit (10) is aligned with the transmitter unit (6) during the test phase so that the at least one test signal (15) does not face the window (5); and wherein the detector unit (7) records a component (15') of the at least one test signal (15) and, based on the detected component (15'), at least two detectors A laser scanner device characterized by having at least two optical detectors (7a, 7b, 7c, 7d) configured to generate signals, and the computing unit (2a) configured to determine a pulse width for each of the at least two detector signals, calculate the sum of the determined pulse widths, and check the function of the transmitter unit (6) and / or detector unit (7) based on the sum. Claim 7 A laser scanner device according to claim 6, wherein the deflection unit (10) comprises a rotary or pivoting mirror or a microelectromechanical mirror system. Claim 8 A laser scanner device according to claim 6, wherein each of the at least two optical detectors (7a, 7b, 7c, 7d) includes a photodiode, and the control unit (8) is configured to operate the photodiode under reverse bias and to control a reverse voltage for operating the photodiode during the test step to set a predefined detector sensitivity of the detector unit (7). Claim 9 A laser scanner device according to claim 8, characterized in that the control unit (8) is configured to operate all photodiodes of the at least two optical detectors (7a, 7b, 7c, 7d) using the same controlled reverse voltage in each case during the test step. Claim 10 A laser scanner device according to claim 8, characterized in that the control unit (8) is configured to determine a setpoint value for closed-loop control of the reverse voltage according to the detector sensitivity based on given calibration data. Claim 11 A vehicle equipped with a laser scanner device (2) according to any one of claims 6 to 10. Claim 12 A computer program stored in a computer-readable storage medium having instructions that cause a laser scanner device (2) according to any one of claims 6 to 10 to perform a method according to any one of claims 1 to 5.

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