Lidar sensor and vehicle

Abstract

The present invention relates to a lidar sensor and a vehicle, wherein the lidar sensor comprises: a transmitting unit (10), a receiving unit (20), a protective window (30), a housing (40) and an evaluation unit (50), wherein the transmitting unit (10) is designed to generate a laser pulse (60) which is emitted into an environment of the lidar sensor, the receiving unit (20) is designed to receive, by means of a detector (22), portions of the emitted laser pulse (60) reflected in the environment through the protective window (30) and to generate a signal corresponding to the reflected portions of the laser pulse (60), and wherein the evaluation unit (50) is designed to switch the receiving unit (20) into a first to switch to receive mode,to set the receiving unit (20) into a second receiving mode at a predefined time interval from the transmission of the laser pulse (60), and wherein the evaluation unit (50) is configured to receive the signal generated by the receiving unit (20) and to distinguish first signal components generated by partial reflections at the protective window (30) from second signal components generated by reflections on objects in the vicinity of the lidar sensor.

Description

State of the art

[0001] The present invention relates to a lidar sensor and a vehicle with such a lidar sensor.

[0002] Lidar sensors are known from the state of the art and are used, for example, in vehicle environment detection systems in order to operate driver assistance systems and / or systems for automated driving, etc., based on the detected environmental information.

[0003] Such lidar sensors usually have a protective glass, which protects the interior of the lidar sensors from moisture, dirt, damage, etc. due to environmental influences and which acts as an exit and entry surface for measurement signals (i.e., for laser pulses) of the lidar sensor.

[0004] Although the protective window is essentially transparent to laser light generated by the lidar sensor, deposits on the protective glass and / or surface defects of the protective glass (e.g., scratches) can lead to unwanted partial reflections of the laser light within the lidar sensor.

[0005] Depending on the strength of such partial reflections and the configuration of a detector of the lidar sensor, such partial reflections can cause saturations within pixels of a photodetector of the lidar sensor, which can at least partially mask laser pulse echoes generated by objects in the vicinity of the vehicle, so that detection of objects in the immediate vicinity of the lidar sensor can be restricted or prevented.

[0006] Therefore, various methods are used in the state of the art to distinguish between such unwanted partial reflections and reflections from actual objects in the vicinity of the lidar sensor. These include, for example, variable threshold adjustment or echo separation algorithms that operate based on superimposed signal components from the partial reflections of the protective window and actual object echoes.

[0007] WO2021258111A1 describes a lidar system which is configured to increase a bias voltage of one or more photodetectors after the activation of a light emitter of the lidar system, wherein the increase in the bias voltage occurs as a function of a time which has elapsed since the activation of the light emitter. Disclosure of the invention

[0008] According to a first aspect of the present invention, a lidar sensor, in particular a lidar sensor for a vehicle, is proposed, wherein the lidar sensor is preferably a “time of flight” lidar sensor which is configured to determine distances to objects in the environment of the lidar sensor on the basis of a measurement of travel times of an emitted laser light.

[0009] The lidar sensor comprises at least: a transmitting unit, a receiving unit, a protective window, a housing and an evaluation unit, wherein the transmitting unit comprises, for example, one or more laser diodes, wherein the protective window is formed, for example, from glass and / or from a transparent plastic material and wherein the evaluation unit is designed, for example, as an ASIC, FPGA, processor, digital signal processor, microcontroller, or the like.

[0010] The transmitter and receiver units are located inside the housing, and the protective window is integrated into a cutout in the housing wall. The protective window thus forms an optical interface between the interior of the lidar sensor and the environment of the lidar sensor, protecting components located inside the lidar sensor from environmental influences such as moisture and contamination.

[0011] The transmitting unit is configured to generate a laser pulse, which is emitted through the protective window into the surroundings of the lidar sensor to detect the surroundings. It should be noted that the temporal profile of the laser pulse is not limited to a specific shape, and in particular not to a rectangular pulse, but can, in principle, have any desired shape. A respective transmission process for transmitting respective laser pulses is initiated, for example, by the evaluation unit and / or a different component of the lidar sensor (e.g., by the transmitting unit itself).

[0012] The receiving unit is configured to receive, by means of a detector (specifically, a photodetector), components of the emitted laser pulse reflected in the surroundings through the protective window and to generate a signal (in particular, an electrical signal) corresponding to the reflected components of the laser pulse. For this purpose, the spectral sensitivity of the detector is advantageously substantially matched to a wavelength of the emitted laser pulse. A surface of the detector is preferably composed of a plurality of light-sensitive pixels, wherein the number of pixels and the arrangement of the pixels are fundamentally unlimited and are advantageously determined depending on the respective configuration and / or intended use of the lidar sensor (e.g., as a one-dimensional pixel arrangement, as a two-dimensional pixel arrangement, etc.).

[0013] The evaluation unit, which is connected to the receiving unit for information technology purposes, is configured to put the receiving unit into a first receiving mode before receiving partial reflections of a respective laser pulse, which are caused within the lidar sensor by the protective window. Such partial reflections can represent an interference influence during environmental detection by the lidar sensor, as they can lead to undesired saturation in the detector and the associated overlap of echoes from objects (i.e., reflected portions of the laser pulse from objects in the vicinity of the lidar sensor), whereby the detection of objects is significantly less reliable or even impossible, particularly in the close range of the lidar sensor. Such a close range corresponds, for example, to a range up to a distance of 20 m, 10 m or less from the lidar sensor.

[0014] Partial reflections can occur in particular when the light transmission of the protective window is partially or completely restricted, for example due to deposits on a side of the protective window facing the environment of the lidar sensor, where such deposits can include dirt particles and / or water droplets, etc. Alternatively or additionally, it is possible that such impairment of the protective window can be caused by damage to the surface of the protective window, which can occur, for example, in the form of scratches. It is therefore likely that the partial reflections at the protective window described above will increase with the increasing service life of the lidar sensor due to the expected increasing damage. In addition, such partial reflections can become more pronounced the larger the angle between a transmission path of the lidar sensor and the protective window orbetween a receiving path of the lidar sensor and the protective window.

[0015] The evaluation unit is further configured to place the receiving unit into a second receiving mode for emitting the laser pulse at a time interval, which may be a predefined time interval and / or a dynamically adjusted time interval, wherein the receiving unit has a lower light sensitivity in the first receiving mode than in the second receiving mode. By suitably defining the respective light sensitivity in the first receiving mode and in the second receiving mode, a disadvantageous superposition of useful echoes (i.e., echoes generated by objects in the vicinity of the lidar sensor) by partial reflection echoes (i.e., echoes generated on the protective glass in the interior of the lidar sensor) can be reduced or completely avoided. In this way, the probability that the useful echoes can be distinguished from the partial reflection echoes can be increased.

[0016] The evaluation unit is also configured to receive the signal generated by the receiving unit and to distinguish between first signal components generated by partial reflections at the protective window and second signal components within the signal, which are generated by reflections from objects in the vicinity of the lidar sensor. To distinguish between the respective signal components, known methods for identifying the respective signal components (e.g., by comparing them with suitable threshold values) and / or methods deviating from these can be used, for example.

[0017] The identified signal components generated by useful echoes can then be provided, for example, to a component capable of determining the distances and / or sizes of objects in the vicinity of the lidar sensor based on these signal components. This provision is achieved, for example, by the evaluation unit and / or a different component of the lidar sensor.

[0018] The lidar sensor according to the invention thus offers the particular advantage that interference caused by partial reflection echoes can be reduced or avoided, which enables detection of objects even in the close range of the lidar sensor or increases the reliability of detection of objects in the close range.

[0019] It should be noted that switching between the first reception mode and the second reception mode can be implemented immediately or using a predefined temporal transition between the reception modes, using one or more intermediate stages between the two reception modes. Alternatively, it is also possible to perform such a temporal transition continuously.

[0020] It should also be noted that, in addition to adjusting the light sensitivity depending on the presence of useful echoes or partial reflection echoes, it is conceivable to adjust the transmitting power of the transmitting unit by means of a suitable control, for example by the evaluation unit, in order to further reduce or avoid saturation or overloading of the detector due to the reception of the partial reflection echoes.

[0021] The subclaims show preferred developments of the invention.

[0022] In an advantageous embodiment of the present invention, the detector of the receiving unit is a SPAD (“single photon avalanche diode”)-based detector, which enables particularly high sensitivity and / or range when detecting the surroundings using such a lidar sensor. Furthermore, a SPAD-based detector offers particularly high flexibility in determining suitable first and second light sensitivities. Alternatively or additionally, the lidar sensor is designed as a point scanner and / or a line scanner and / or a flash sensor.

[0023] In a further advantageous embodiment of the present invention, the time interval from the time of emission of the laser pulse is determined as a function of a propagation time of the laser pulse, which results from the length of an optical path from the transmitting unit to the protective window and from the protective window to the receiving unit. Alternatively or additionally, the time interval is determined as a function of a duration and / or a profile and / or an amplitude of the laser pulse. Since the evaluation unit knows the time of emission of the laser pulse, the evaluation unit can determine the time for switching from the first receiving mode to the second receiving mode, and the switching process can be initiated at the determined time or at a time that has a predefined time offset from the determined time.The time of emission of the laser pulse can be provided to the evaluation unit via the transmission unit and / or another component of the lidar sensor. Alternatively or additionally, the emission of the laser pulse can be initiated by the evaluation unit itself, so that the time of emission can be determined based on the initiation. The aforementioned predefined offset can advantageously be adapted to a duration and / or a temporal profile of the laser pulse, so that the switching process between the sensitivity modes only takes place, for example, at a time when the laser pulse is in a region of a falling edge of the laser pulse, to ensure that saturation does not occur in the detector due to premature switching.

[0024] Advantageously, the evaluation unit is configured to operate all or some of the pixels of the detector in the first reception mode in non-amplified operation, in linear operation, in Geiger operation (i.e., above a breakdown voltage of photodiodes of the detector, wherein Geiger operation represents single-photon detection) or in mixed operation and / or to operate them in the second reception mode in mixed operation or in Geiger operation. Mixed operation is to be understood as an operation in which a bias voltage (in particular a reverse bias voltage) is applied to photodiodes of the detector in the range of the breakdown voltage, so that statistically speaking, some of the photodiodes (i.e., the reception pixels) are in linear operation and some are in Geiger operation.In addition, it is possible to evaluate individual detector pixels of the detector individually and / or to define predefined groups of detector pixels as macropixels, whose individual received signals are combined to produce a resulting overall signal. In an exemplary embodiment, the detector is configured by means of the evaluation unit so that it operates in linear mode in the first receive mode and in Geiger mode in the second receive mode. Alternatively, it is conceivable for the detector to operate in mixed mode in the first receive mode and in Geiger mode in the second receive mode. In addition, it is possible to use the photodiodes in unamplified mode in the first mode, so that the partial reflections do not lead to any or only a low amplitude in the corresponding signal components. This allows a particularly reliable separation of the useful echoes from the partial reflection echoes to be achieved.In addition, any further combinations of operating states in the first and second reception modes are possible, which can preferably be set depending on a design of the lidar sensor and / or current boundary conditions and / or a current use of the lidar sensor.

[0025] Particularly advantageously, the evaluation unit is configured to switch from the first reception mode to the second reception mode when amplitude values ​​of a falling edge of the first signal components of the laser pulse, which are reflected by the protective window, fall below a predefined threshold. This offers the particular advantage that the switching time is adjusted depending on current boundary conditions. In an exemplary case in which the surface quality of the protective window deteriorates due to damage over the service life of the lidar sensor and thus a higher proportion of partial reflections at the protective window is to be expected, which can lead to greater saturation in the detector, it can be assumed that a temporally changed (e.g., extended) overlap of useful echoes by partial reflection echoes occurs.By using the threshold value to determine the switching time between the reception modes, the switching time can be advantageously adapted to changing boundary conditions, thus ensuring a reliable differentiation between useful echoes and partial reflection echoes despite changed boundary conditions.

[0026] Furthermore, the lidar sensor is advantageously configured to maintain a respective predefined light sensitivity in the first reception mode and / or in the second reception mode by means of a closed-loop control, for example by regulating the amplitudes of the respective signal components by adjusting the respective bias voltages of the photodiodes to corresponding target values ​​(e.g., maximum permissible amplitude values). Such a closed-loop control is particularly advantageous because the respective light sensitivities can be set or maintained with particular precision in this way. For example, even slight temperature changes can lead to undesirable changes in the light sensitivities set by means of respective bias voltages. Furthermore, such a closed-loop control offers the advantage that the degree of impairment of the light transmittance of the protective window can be determined based on the extent of the closed-loop control.Such information on the degree of impairment of light transmission can be used, among other things, to evaluate the reliability of object detection based on the lidar sensor and / or to issue an advisory message to a user (e.g., a cleaning and / or service recommendation, etc.) and / or to activate a functionally restricted operation, etc.

[0027] Preferably, the lidar sensor is configured to control the light sensitivity based on an evaluation of an amplitude and / or a width and / or an area and / or a temporal profile of the respective received signal components. It is also possible to control the light sensitivity at the individual pixel level and / or at the macropixel level and / or globally, i.e., for an entire detector area.

[0028] In a further advantageous embodiment of the present invention, in a case in which the lidar sensor is designed as a scanning lidar sensor, the evaluation unit is configured to adapt a light sensitivity in the first reception mode and / or in the second reception mode and / or a time for switching from the first reception mode to the second reception mode depending on a current rotation angle of a deflection unit of the lidar sensor. The deflection unit serves to deflect a laser beam, for example a point-shaped or linear one, which is generated by a stationary transmitter unit, in a horizontal and / or vertical direction in order to move the laser beam sequentially across the entire field of view to be captured by the lidar sensor.The adjustment of the light sensitivities and / or the switching time as a function of the rotation angle offers the advantage that fluctuations in the intensity of the partial reflections, which are caused by different angles of incidence on the protective glass during a scanning process of the lidar sensor, can be at least partially compensated, whereby the differentiation of useful echoes and partial reflection echoes can be ensured with a high degree of reliability, regardless of the respective rotation angle of the deflection unit. Alternatively or additionally, it is also advantageously possible to adjust the light sensitivity in the first reception mode and / or in the second reception mode and / or the time for switching from the first reception mode to the second reception mode as a function of a location and / or an extent of impairment of the light transmission of the protective window (e.g.caused by contamination, scratches, heating wires integrated into the protective window, etc.). This also ensures the above-described advantage of an essentially uniform differentiation between useful echoes and partial reflection echoes.

[0029] It is furthermore advantageous if the evaluation unit is set up to calibrate the light sensitivity of the detector for the first reception mode and / or the second reception mode. This is done, for example, by one or more environment detection processes with different bias voltages in order to set an optimal bias voltage in each case depending on the currently existing boundary conditions. For example, the calibration can be regarded as complete when a maximum permissible threshold value for an amplitude of the signal generated in the detector is maintained and / or undershot and / or when a distinction can be made between partial reflection echoes and echoes from nearby objects, which is determined, for example, on the basis of compliance with a predefined minimum detection probability for certain objects (in particular nearby objects). Furthermore, it is possible to carry out such a calibration before or after.during a system start of the lidar sensor and / or recurringly during the ongoing operation of the lidar sensor.

[0030] According to a second aspect of the present invention, a vehicle having a lidar sensor according to the first aspect of the invention is proposed. The vehicle is, for example, a road vehicle (e.g., a car, van, truck, motorcycle, etc.) or a rail vehicle, an aircraft / plane, or a watercraft. The lidar sensor is used, for example, in an environment detection system of the vehicle, which can be used, among other things, for partially automated and / or fully automated driving and / or for various driver assistance systems of the vehicle. The features, combinations of features, and the advantages resulting from them correspond to those explained in connection with the first aspect of the invention, so that reference is made to the above explanations to avoid repetition. Short description of the drawings

[0031] Embodiments of the invention are described in detail below with reference to the accompanying drawings. In the drawing: Fig. 1 is a schematic view of an embodiment of a lidar sensor according to the invention; Fig. 2 a view of exemplary temporal courses of laser pulse echoes and corresponding electrical signals; and Fig. 3 a schematic view of an embodiment of a vehicle according to the invention in conjunction with a lidar sensor according to the invention. Embodiments of the invention

[0032] Fig. 1 shows a schematic view of an embodiment of a lidar sensor according to the invention, which has a transmitting unit 10, a receiving unit 20, a protective window 30, a housing 40, an evaluation unit 50 and a deflection unit 90.

[0033] The transmitting unit 10, the receiving unit 20, the evaluation unit 50 and the deflection unit 90 are arranged within the housing 40 of the lidar sensor, while the protective window 30, which here is made of a transparent plastic material, is integrated into a cutout of a wall of the housing 40.

[0034] The lidar sensor is designed here as a line scanner, in that the transmitting unit 10 is set up to generate a line-shaped laser pulse 60 by means of a laser diode arrangement and to transmit this via a rotational movement of the deflection unit 90 (see arrow in Fig. 1) to scan the surroundings of the lidar sensor and deflect it into the surroundings.

[0035] The evaluation unit 50, which is designed here as an ASIC, is informationally connected to the transmitting unit 10 and the receiving unit 20 and is thus configured to control the transmitting unit 10 in order to generate respective laser pulses 60 by means of the transmitting unit 10 at predefined times, wherein the respective laser pulses 60 are emitted into the surroundings of the lidar sensor via the deflection unit 90 through the protective window 30.

[0036] The receiving unit 20 is configured to receive, by means of a detector 22, which here is a SPAD-based detector, components of the emitted laser pulse 60 reflected in the surroundings through the protective window 30 and to generate a signal corresponding to the reflected components of the laser pulse 60.

[0037] The evaluation unit 50 is further configured to place the receiving unit 20 into a first receiving mode prior to the reception of partial reflections 70 of a respective laser pulse 60, which are caused within the lidar sensor by the protective window 30. The first receiving mode corresponds to a linear operation of SPAD photodiodes of the detector 22, which is achieved by applying a corresponding first reverse bias voltage U1 (see Fig. 2) to the respective SPAD photodiodes of the detector 22 by the evaluation unit 50.

[0038] The evaluation unit 50 is further configured to switch the receiving unit 20 into a second receiving mode at a time interval from the transmission of the laser pulse 60, wherein the receiving unit 20 has a lower light sensitivity in the first receiving mode than in the second receiving mode. This is achieved in that the second receiving mode corresponds to a Geiger operation of the SPAD photodiodes of the detector 22, which is achieved by applying a corresponding second reverse bias voltage U2 (see Fig. 2) to the respective SPAD photodiodes of the detector 22 by the evaluation unit 50.

[0039] The time interval for transmitting the laser pulse 60, which corresponds to the switching time from the first reception mode to the second reception mode, is determined dynamically by the evaluation unit 50 and is present whenever amplitude values ​​of a falling edge of the first signal components 80 of the laser pulse 60, which are reflected by the protective window 30, exceed a predefined threshold value S (see Fig. 2) below.

[0040] The evaluation unit 50 is furthermore configured to receive the signal generated by the receiving unit 20 and to detect first signal components 80 generated by partial reflections at the protective window 30 (see Fig. 2) of second signal components 85 (see Fig. 2) which are generated by reflections from objects in the vicinity of the lidar sensor. The differentiation between the two signal components 80, 85 is carried out here based on a detection threshold value for an amplitude of the signal components 80, 85. The detection threshold value is advantageously a dynamically adjustable detection threshold value, which is adjusted depending on current boundary conditions (e.g., a maximum and / or an average existing illuminance on the detector 22) in order to permanently ensure optimal distinguishability of the signal components 80, 85.

[0041] Particularly advantageously, the evaluation unit 50 is further configured to maintain a respective predefined light sensitivity in the first reception mode and / or in the second reception mode by means of a control and to determine a degree of impairment of the light transmission of the protective window 30 based on the extent of the control. The control of the light sensitivity is carried out here based on an evaluation of an area and a temporal progression of the respective received signal components 80, 85.

[0042] Fig. Figure 2 shows a view of exemplary temporal courses of laser pulse echoes, which are formed by partial reflections 70 at the protective window 30 (see Fig. 1 or Fig. 3) and by object reflections 75 on objects in the vicinity of the lidar sensor. In addition, exemplary curves of electrical signals 80, 85 are shown, which are generated by the receiving unit 20 (see Fig. 1 or Fig. 3) and correspond to the laser pulse echoes.

[0043] The upper diagram in Fig. 2 shows the curves of the respective illuminances on the detector 22 (see Fig. 1) of the receiving unit 20, which are generated by the partial reflections 70 and the object reflections 75 of the laser pulse 60. This diagram also shows a profile of a bias voltage applied to respective photodiodes of the detector 22, wherein the bias voltage is switched from a first bias voltage U1 to a second bias voltage U2 at a switching time Ts, so that the light sensitivity of the detector 22 is lower before the switching time Ts than after the switching time Ts.

[0044] This leads to the first signal components 80 generated by the detector 22 (see lower diagram in Fig. 2), which correspond to the reception of the partial reflections 70 and the second signal components 85 generated by the detector 22 (see lower diagram in Fig. 2) are at least partially matched to one another with respect to their respective amplitudes A. This leads to the effect that the probability that the first signal components 80 will saturate and that, as a result, a disadvantageous overlap of the second signal components 80 by the first signal components 85 will occur is reduced.

[0045] For comparison, an exemplary saturated signal 110 is shown by means of a dashed line, which could be caused by the partial reflections 70 without a switching of the light sensitivities in the detector 22 at the switching time Ts and would thus lead to a disadvantageous overlap of the second signal components 85, as a result of which a detection of objects in the near range would not be possible or would only be possible to a limited extent.

[0046] Fig. 3 shows a schematic view of an embodiment of a vehicle 100 according to the invention, which is designed here as a passenger car, in conjunction with a lidar sensor according to the invention, wherein the lidar sensor is represented by a housing 40, a protective window 30, a transmitting unit 10, a receiving unit 20 and an evaluation unit 50, without thereby being limited to the components described above.

[0047] The lidar sensor according to the invention is connected in terms of information technology to a system 120 for automated driving of the vehicle 100, so that the vehicle 100 is configured to receive output signals generated by the lidar sensor and, based on the output signals, to carry out automated control of the vehicle 100. Since the output signals of the lidar sensor contain particularly reliable information about objects in the vicinity of the lidar sensor, a particularly safe automated driving of the vehicle 100 is possible, which can relate, for example, to traffic scenarios such as vehicles merging and / or vehicles with overhanging loads, etc., in the vicinity of the vehicle 100 and / or to traffic scenarios deviating therefrom. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] WO 2021258111A1

[0007]

Claims

[1] Lidar sensor comprising: - a transmitting unit (10), - a receiving unit (20), - a protective window (30), - a housing (40), and - an evaluation unit (50), wherein - the transmitting unit (10) and the receiving unit (20) are arranged within the housing (40) and the protective window (30) is integrated into a cutout of a wall of the housing (40), - the transmitting unit (10) is designed to generate a laser pulse (60) which is emitted through the protective window (30) into the surroundings for detecting an environment of the lidar sensor, - the receiving unit (20) is configured to receive, by means of a detector (22), components of the emitted laser pulse (60) reflected in the surroundings through the protective window (30) and to generate a signal corresponding to the reflected components of the laser pulse (60), - the evaluation unit (50) is set up, - to set the receiving unit (20) into a first receiving mode before receiving partial reflections (70) of a respective laser pulse (60) which are caused within the lidar sensor by the protective window (30), - to set the receiving unit (20) into a second receiving mode at a time interval from the transmission of the laser pulse (60), wherein the receiving unit (20) has a lower light sensitivity in the first receiving mode than in the second receiving mode, and - to receive the signal generated by the receiving unit (20) and to distinguish first signal components (80) generated by partial reflections at the protective window (30) from second signal components (85) which are generated by reflections on objects in the vicinity of the lidar sensor. [2] Lidar sensor according to claim 1, wherein - the detector (22) of the receiving unit (20) is a SPAD detector, and / or - the lidar sensor is designed as a point scanner and / or as a line scanner and / or as a flash sensor. [3] Lidar sensor according to one of the preceding claims, wherein the time interval for emitting the laser pulse (60) is a predefined time interval which is dependent - a transit time of the laser pulse (60) is determined, which results from a length of an optical path from the transmitting unit (10) to the protective window (30) and from the protective window (30) to the receiving unit (20), and / or - a duration and / or a temporal course and / or an amplitude of the laser pulse (60) is determined. [4] Lidar sensor according to one of the preceding claims, wherein the evaluation unit (50) is configured to switch from the first reception mode to the second reception mode when amplitude values ​​(A) of a falling edge of the first signal components (80) of the laser pulse (60) which are reflected by the protective window (30) fall below a predefined threshold value (S). [5] Lidar sensor according to one of the preceding claims, wherein the evaluation unit (50) is arranged to evaluate all or part of the pixels of the detector (22) - to operate in the first receive mode in a non-amplified mode, in a linear mode, in a Geiger mode or in a mixed mode, and / or - to operate in the second reception mode in mixed operation or in Geiger operation. [6] Lidar sensor according to one of the preceding claims, wherein the lidar sensor is arranged - to maintain a respective predefined light sensitivity in the first reception mode and / or in the second reception mode by means of a control, and / or - to determine a degree of impairment of the light transmission of the protective window (30) on the basis of an extent of the regulation. [7] Lidar sensor according to claim 6, wherein the lidar sensor is configured to control the light sensitivity on the basis of an evaluation - an amplitude (A), and / or - a width, and / or - an area, and / or - a temporal progression of each received signal component (80, 85). [8] Lidar sensor according to one of the preceding claims, wherein the evaluation unit (50) is configured, in a case in which the lidar sensor is designed as a scanning lidar sensor, to determine a light sensitivity in the first reception mode and / or in the second reception mode and / or a time (Ts) for switching from the first reception mode to the second reception mode as a function of - a current rotation angle of a deflection unit (90) of the lidar sensor, and / or - a location and / or extent of impairment of light transmission of the protective window (30). [9] Lidar sensor according to one of the preceding claims, wherein the evaluation unit (50) is configured to perform a calibration of the light sensitivity of the detector (22) for the first reception mode and / or the second reception mode. [10] Vehicle (100) comprising a lidar sensor according to one of the preceding claims.

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