Method for identifying false-positive detections during operation of an active optical sensor system and for guiding a motor vehicle, active optical sensor system and electronic vehicle guidance system

Abstract

For identifying false-positive detections during operation of an active optical sensor system (3), light (5a) is emitted and reflected portions (5b) are received by means of a detector unit (9) which has an array (17) of detector pixels (12a, 13a). A first measurement value relating to a first energy input per detector pixel (12a, 13a) is determined in that an overlap region between at least one row (12, 13) of the array (17) and a first set of columns (14) is read out. A second measurement value relating to a second energy input per detector pixel (12a, 13a) is determined in that an overlap region between the at least one row (12, 13) and a second set of columns (15) is read out. The second set contains at least one additional column which the first set does not contain. A detection of an object (4) in the surroundings, the position of which corresponds to the at least one row (12, 13), is classified as false-positive depending on the first measurement value and the second measurement value.

Description

[0001] Method for identifying false-positive detections when operating an active optical sensor system and driving a motor vehicle, active optical sensor system and electronic vehicle guidance system

[0002] The present invention is directed to a method for identifying false-positive detections during operation of an active optical sensor system, in particular an active optical sensor system of a motor vehicle. Light is emitted into an environment of the active optical sensor system by means of the active optical sensor system, and portions of the emitted light reflected in the environment are received by a detector unit of the active optical sensor system, which has an array of detector pixels with a plurality of rows and a plurality of columns. The invention is further directed to a method for at least partially automatically driving a motor vehicle, which includes such a method for identifying false-positive detections.The invention is also directed to an active optical sensor system comprising an evaluation unit and a transmitting device with at least one light source configured to emit light into an environment of the active optical sensor system, and a detector unit comprising an array of detector pixels with a plurality of rows and a plurality of columns configured to receive portions of the emitted light reflected in the environment. Furthermore, the invention is directed to an electronic vehicle guidance system for a motor vehicle having such an active optical sensor system.

[0003] Active optical sensor systems, such as lidar sensor systems, can be used, for example, in electronic vehicle guidance systems for motor vehicles to implement various driver assistance functions or other functions for partially or fully automated vehicle control. These active optical sensor systems are used primarily for distance measurement. Depending on the design of the active optical sensor system, a time-of-flight measurement can be used for distance measurement.

[0004] Since the most comprehensive environmental detection possible is advantageous for driving motor vehicles, it is desirable to be able to use the active optical sensor system for distance measurement for objects with different properties, particularly reflection properties with respect to the light emitted by the active optical sensor system. In other words, it should be possible to measure both very weakly reflective objects, such as black objects, at a very great distance, as well as very highly reflective objects, such as retroreflectors, such as parts of traffic signs, at close range.

[0005] The result is that in the case of very highly reflective objects, detector pixels in the array can detect significant amounts of reflected light, even though there is no real object at the position in the vicinity of the active optical sensor system assigned to these detector pixels. This is also referred to as optical crosstalk. Furthermore, reflections and multiple reflections in the environment can lead to artifacts, which are referred to as ghosting, because they also indicate apparent objects even though there is no real object in the corresponding area in the environment. In both cases, false positive detections of objects in the vicinity of the active optical sensor system can occur.If these false-positive detections cannot be distinguished from true-positive detections, the distance to an object that is not actually present is calculated and used as the basis for vehicle control. This can lead to implausible results or, in some cases, even reduced driving safety.

[0006] False positive detections can be detected, for example, when two adjacent receiving channels measure a similar distance but significantly different reflection strengths at the same time. The measurement of the stronger reflection can then be interpreted as a true positive detection, while the other as a false positive. A corresponding method is described in document US 11,500,075 B2.

[0007] However, such an approach has the disadvantage that, firstly, only false positive detections that are in the immediate vicinity of a true positive detection can be detected. In the case of very highly reflective objects, however, false positive detections can also occur further away from true positive detections and cannot be identified in this way. Another disadvantage is that a comparison of the measured apparent distances is required, and only false positive detections can be identified that appear to indicate a virtually identical distance to a neighboring true positive detection. In the case of very highly reflective objects, it is also possible that adjacent pixels each detect strong reflections, so that false positive detections do not necessarily occur directly next to true positive detections.Overall, this significantly limits the number of identifiable false positives. The reliability of identifying false positives may therefore be insufficient.

[0008] It is an object of the present invention to be able to detect false-positive detections more reliably when operating an active optical sensor system.

[0009] This object is achieved by the respective subject matter of the independent claims. Advantageous further developments and preferred embodiments are the subject matter of the dependent claims.

[0010] The invention is based on the finding that neighboring detector pixels in the area of ​​false-positive detections measure a more homogeneous energy input across multiple detector pixels than in an area of ​​true-positive detection. Accordingly, according to the invention, two measurements are performed: one reading an overlap region of at least one row of the array with a first set of columns of the array, and the second measurement reading an overlap region of the same at least one row with a second set of columns of the array, which has at least one column that the first set does not have. Based on the two measurements, a detection corresponding to the measured at least one row can be classified as a false positive.

[0011] According to one aspect of the invention, a method is provided for identifying false-positive detections during operation of an active optical sensor system, in particular an active optical sensor system of a motor vehicle. By means of the active optical sensor system, light is emitted into an environment of the active optical sensor system, in particular into an environment of the motor vehicle. Portions of the emitted light reflected in the environment are received by a detector unit of the active optical sensor system. The detector unit has an array of detector pixels. The array has a plurality of rows and a plurality of columns. In particular, each detector pixel is defined by exactly one row and exactly one column of the array. A first measured value relating to a first energy input per detector pixel of the detected reflected portions of the light is determined by reading out a first region of the array.The first region of the array is an overlap region of at least one row of the array with a first set of columns of the array. A second measured value relating to a second energy input per detector pixel of the detected reflected portions of the light is determined by reading out a second region of the array. The second region of the array is an overlap region of the at least one row of the array with a second set of columns of the array, which in particular differs from the first set of columns. The second set of columns contains at least one further column of the array which the first set of columns does not contain. A detection of an object in the environment whose position corresponds to the at least one row is classified as a false positive depending on the first measured value and the second measured value.

[0012] By definition, an active optical sensor system comprises at least one light source for emitting light or light pulses. The light source can be configured, in particular, as a laser, for example, an infrared laser. Furthermore, by definition, an active optical sensor system comprises at least one optical detector, in this case the array of detector pixels, for detecting the reflected portions of the emitted light. The active optical sensor system is configured, in particular, to generate, process, or output one or more sensor signals based on the detected portions of the light. Lidar systems, for example, are active optical sensor systems.

[0013] A well-known type of lidar system is a laser scanner, in which a laser beam is deflected by a deflection device, allowing different deflection angles of the laser beam to be achieved. The deflection device can, for example, contain a rotatably mounted mirror. Alternatively, the deflection device can have a mirror element with a tiltable and / or pivotable surface. The mirror element can, for example, be designed as a microelectromechanical system (MEMS). The emitted laser beams can be partially reflected in the environment, and the reflected portions can, in turn, strike the laser scanner, in particular the deflection device, which can direct them onto a detector unit of the laser scanner. Each optical detector or detector pixel generates, for example, an associated sensor signal based on the respective detected portions.Based on the spatial arrangement of the respective detector, together with the current position of the deflection device, in particular its rotational position or its tilt and / or pivot position, the direction of incidence of the detected reflected components can be determined. An evaluation unit can also, for example, perform a direct time-of-flight measurement to determine the radial distance of the reflecting object. Alternatively or additionally, a method can be used to determine the distance by evaluating a phase difference between emitted and detected light, for example, an indirect time-of-flight measurement.

[0014] Other types of lidar systems are flash lidar systems. These are non-scanning systems that do not require such a deflection device. The laser light generated by the light source is scattered by an optical element, so that it is emitted in a single flash across a wide angle.

[0015] Here and below, the term "light" can be understood to include electromagnetic waves in the visible, infrared, and / or ultraviolet ranges. Accordingly, the term "optical" can also be understood to refer to light in this sense. Preferably, the light emitted by the active optical sensor system is infrared light.

[0016] A false-positive detection can be understood here and below as the detection of an apparent object without there being a real object in the vicinity of the optical sensor system at a corresponding position. If the detection of the object is therefore classified as a false positive, it is not a real object, but rather an apparent object or apparent object. In particular, the object can be detected by comparing the first energy input and / or the second energy input with a corresponding minimum energy input, whereby a detection can be considered to have occurred if the first and / or the second measured value is greater than or equal to the corresponding minimum energy input. However, further measured values ​​relating to the energy input in the first area or the second area or a sub-area of ​​the first or second area can also be determined in order to detect the object.According to the invention, the detection thus made is then classified, based on the first measured value and the second measured value, either as a false positive or not as a false positive. If the detection is not classified as a false positive, it can be classified, for example, as a true positive or unclear or the like. For example, the active optical sensor system can generate a point cloud based on all object detections, wherein, for example, each point of the point cloud corresponds to a detection and is characterized by a corresponding three-dimensional position including a distance from the active optical sensor system and, if appropriate, by further characteristics, such as a measure of the strength of the detection, for example the corresponding energy input, an echo pulse width, and so on.However, the further characteristics depend in each individual case on the specific design of the active optical sensor system, in particular the detector unit and / or the detector pixels.

[0017] For example, it is possible that when generating the point cloud, only those detections that have not been classified as false positives are taken into account. In other words, the point cloud contains only points that do not correspond to detections classified as false positives. Alternatively, the point cloud can also include points that correspond to detections classified as false positives, whereby, for example, additional information is stored about which points are due to detections classified as false positives.

[0018] When using the point cloud or other results of the operation of the active optical sensor system, for example for at least partially automatic guidance of the motor vehicle, only points of the point cloud can be used that do not correspond to detections classified as false positives.

[0019] The active optical sensor system can be designed, for example, as a lidar sensor system, in particular as a laser scanner.

[0020] Depending on the design of the active optical sensor system, the light can be emitted, for example, in the form of successive light pulses. The emission of the light or light pulses can occur over several measurement cycles. The reading of the first region or the second region can take place in different measurement cycles or in the same measurement cycle, if the latter is provided for in the design of the active optical sensor system and the array of detector pixels.

[0021] The number of the plurality of rows is in particular three or more. The number of the plurality of columns is also in particular three or more. The total number of detector pixels is given by NxM, where N is the number of the plurality of rows and M is the number of the plurality of columns. The number of detector pixels is therefore in particular greater than or equal to nine. The total number of detector pixels can also be significantly larger, for example in the order of magnitude of ten to 100 or from 100 to 200. Furthermore, each detector pixel can contain exactly one photodetector or several photodetectors, in particular single-photon detectors.

[0022] The first and second energy input per detector pixel, or the first and second measured values, can therefore be determined differently depending on the design of the array or detector unit. For example, each detector pixel can generate a corresponding detector signal depending on the received portion of the reflected light, which then corresponds, for example, to a voltage or current proportional to the incident radiation power. This can be achieved, for example, by avalanche photodiodes (APDs) operating below their breakdown voltage.On the other hand, especially when using single-photon detectors, such as single-photon avalanche photodiodes (SPADs), the number of detected photons or the number of correspondingly triggered single-photon detectors can also be counted in order to determine the energy input per detector pixel and accordingly the first or second measured value.

[0023] The array and, if applicable, the deflection device enable spatial resolution in two dimensions. A point from which a reflected portion of the detected light strikes the detector unit or the array of detector pixels can be defined in a reference coordinate system, also referred to as a world coordinate system, vehicle coordinate system, or sensor coordinate system, by two angles: an azimuth angle and a polar angle, as well as a radial distance or radius in a polar coordinate system. Unless otherwise stated, it is assumed here and in the following that different rows of the array correspond to different polar angles or different polar angle ranges, and different columns of the array correspond to different azimuth angles or different azimuth angle ranges.However, it is also possible to use a different orientation of the array or to swap the notion of rows and columns. The radial distance is determined in particular by a time-of-flight measurement, for example, a direct time-of-flight measurement. The at least one row preferably consists of exactly one row or of two or more directly consecutive rows of the array. In this way, the detection of the object can be assigned to a contiguous azimuth angle range. Preferably, the at least one row consists of exactly one row, which allows a more precise definition of the azimuth angle range.

[0024] The first set of columns and the second set of columns can each consist of one column or each of two or more directly consecutive columns. Preferably, the first set and the second set of columns each contain two or more directly consecutive columns. In this way, fluctuations in the first and second measured values ​​or inaccuracies in the first and second measured values ​​can be reduced. Furthermore, two or more columns per set of columns result in more different variation options and corresponding embodiments of the invention. However, if the first and second sets each consist of exactly one column, these columns are preferably arranged directly next to one another.

[0025] The fact that the position of the object in the environment, which as described above may also be an apparent object, corresponds to the at least one line can be understood in such a way that the corresponding polar angle of the object corresponds to the at least one line.

[0026] By using the first and second measured values ​​as the basis for classifying the detection of the object as a false positive, the relatively high homogeneity of the energy input of closely located detector pixels in the case of a false positive detection can be advantageously exploited, in contrast to a strong change in the energy input of neighboring detector pixels in the case of a true positive detection.

[0027] This relationship is due in particular to the fact that the so-called point spread function of the active optical sensor system has a very high value in the center and drops off very quickly towards the outside. The point spread function results in particular from the optical components of the active optical sensor system. The point spread function describes in particular deviations from optimal imaging of a point light source by the optical components of the active optical sensor system. The point spread function describes in particular how an idealized point object would be imaged by the active optical sensor system. It is also referred to as the point response and takes into account, for example, diffraction effects, aberrations and so on. The image on the array of detector pixels corresponds in particular to a convolution of the actual shape of the light sources with the point spread function.In other words, the point spread function smears the image on the detector. Typically, the point spread function of the active optical sensor system is approximately radially symmetric.

[0028] According to the invention, it is exploited that false-positive detections, which are caused, for example, by true-positive detections with a very high energy input, i.e., by strongly reflecting objects and / or objects in the near range, generally appear comparatively homogeneous over several neighboring pixels due to the point spread function, in contrast to true-positive detections, which show very rapidly decreasing energy inputs towards surrounding pixels.

[0029] By determining the first measured value and the second measured value as described, wherein in particular the second set of columns has at least one further column that the first set of columns does not have, a statement can be made about the homogeneity of the energy input, which in turn can be used to classify it as a false-positive detection. Using the method according to the invention, in particular each individual detection can be classified as a false-positive or, if appropriate, as a true-positive, independently of other detections in the environment. In particular, no comparison with a true-positive detection is required to identify a false-positive detection as such, since only the high homogeneity in false-positive detections is exploited, but not the absolute amount of the energy input compared to the absolute amount of the energy input in true-positive detections.

[0030] Classifying the object as a false positive can, for example, involve calculating a confidence value based on the first and second measured values. The confidence value can then be compared to a minimum confidence value. If the confidence value is greater than the minimum confidence value, the detection can be classified as a true positive, for example; if it is less than the minimum confidence value, it can be classified as a false positive.

[0031] According to at least one embodiment of the method, the detection of the object is classified as a false positive depending on a ratio of the second measured value to the first measured value or depending on a difference between the first measured value and the second measured value. In particular, the ratio or the difference can correspond to the aforementioned confidence value.

[0032] The difference can be understood as the absolute value of the difference between the first and second measured values, i.e., the absolute value of the difference. In other words, the detection of the object can be classified as a false positive, for example, if the ratio of the second measured value to the first measured value is smaller than a predefined threshold or if the difference between the first measured value and the second measured value is smaller than a predefined additional threshold.

[0033] It should be noted that the first measured value and the second measured value do not scale with the number of detector pixels in the first area or in the second area, since the energy input per detector pixel is considered in each case. With a very homogeneously distributed energy input per detector pixel, it is to be expected that the first measured value and the second measured value are very similar to one another. In other words, the ratio of the first measured value to the second measured value is close to one or the difference is close to zero. The classification as close to one or close to zero can be specified in particular by the aforementioned limit values. This is particularly the case with false-positive detections. In the case of true-positive detections, however, the first measured value and the second measured value differ more significantly from one another.This leads to a ratio of the measured values ​​that is further away from one than in the case of false-positive detections or to a larger difference than in the case of false-positive detections.

[0034] Depending on the scenario and the choice of the specific sets of columns in the array for the first measured value or the second measured value, the evaluation can be carried out differently.

[0035] For example, the first set of columns can be completely contained in the second set of columns, and the second set of columns can be wider than the first set, thus containing additional adjacent columns. Since the energy input per detector pixel is approximately constant in the case of false-positive detections, the first measured value and the second measured value hardly differ from each other. In the case of a true-positive detection, however, the by far highest energy input occurs in the first area, for example, whereas the second area still contributes insignificantly to more energy input. Therefore, the energy input and thus the corresponding measured value change significantly per detector pixel in the case of a true-positive detection. This is indicated by the difference or the ratio as described.

[0036] However, it is also possible for the second set of columns to have the same width as the first set of columns, but offset relative to the first set of columns. Again, the second measured value would not differ significantly from the first measured value if a false positive detection occurred, but would differ significantly if a true positive detection occurred. It is also possible to combine different widths with different positions of the first set and the second set of columns.

[0037] According to at least one embodiment, the at least one further column comprises a first further column following the first set of columns. Alternatively or additionally, the at least one further column comprises a second further column following the first set of columns.

[0038] The first set of columns consists, in particular, of a number of consecutive columns. Within the array, a positive direction can be defined in each of the two dimensions, i.e., for the columns and the rows. In other words, the rows can be numbered ascending from 1 to N, and the columns can be numbered ascending from 1 to M. Each column is thus defined by a column index j with 1 < j < M, and each row by a row index i with 1 < i < N. The fact that the first additional column follows the first set of columns can be understood, in particular, in such a way that the column index of the first additional column is one greater than the largest column index of the first set. The fact that the first set follows the second additional column can be understood in such a way that the column index of the second additional column is one less than the smallest column index of the first set.

[0039] In various embodiments, the first additional column may optionally be followed by one or more additional columns of the second set of columns. In various embodiments, the second additional column may be preceded by one or more additional columns of the second set of columns.

[0040] In particular, in such embodiments, the second set of columns completely includes the first set of columns. In other words, the second set of columns is widened by at least the first and / or second column with respect to the first set of columns. This results in a mean column position or a mean column index of the first set of columns being substantially equal to the mean column index of the second set of columns. The object or the apparent object can thus be determined with equal precision with regard to its azimuth angle by the first set of columns and the second set of columns. Accordingly, it can be assumed with a high degree of probability that the first measured value and the second measured value relate to the same object or apparent object.

[0041] According to at least one embodiment, the second set of columns does not include a column of the first set of columns.

[0042] In other words, the second set of columns is shifted in the column direction relative to the first set of columns so that the second set of columns is directly adjacent to the first set of columns or separated from it by one or more intervening columns. This means that in the case of a true-positive detection, the first measured value differs even more from the second measured value. The distinction between false-positive and true-positive measurements can therefore be made even more reliably.

[0043] It should be noted that in other embodiments, the second set of columns may be shifted less sharply with respect to the first set of columns, so that there is a partial overlap of the first set with the second set.

[0044] According to at least one embodiment, the first measured value is determined by reading the first area in one measuring cycle and the second measured value is determined by reading the second area in the measuring cycle, i.e. in the same measuring cycle.

[0045] In other words, the first and second measured values ​​are determined in the same frame. This can be done especially well if the second set of columns does not contain any columns from the first set. This allows for particularly fast detection classification.

[0046] In alternative embodiments, the first measured value is determined by reading the first area in a first measuring cycle and the second measured value is determined by reading the second area in a second measuring cycle, wherein the second measuring cycle is before or after the first measuring cycle, in particular immediately before or after the first measuring cycle.

[0047] In such embodiments, columns from the first set of columns can also be included in the second set of columns. The first and second measured values ​​are thus determined in different, particularly immediately consecutive, frames.

[0048] This can be advantageous, for example, if the different measurement cycles correspond to different positions of the deflection device of the active optical sensor system, if the system is configured as a laser scanner. In this case, the first set of columns and the second set of columns can be assigned to different sides or surfaces of the deflection device's mirror, which can facilitate the evaluation.

[0049] According to at least one embodiment, the detection of the object is classified as false positive depending on a point spread function of the active optical sensor system.

[0050] In particular, the threshold values ​​explained above can be selected to classify the detection as false positive or, if applicable, as true positive, and so on, depending on the point spread function. The point spread function provides an indication of the extent of the expected inhomogeneity in a true positive measurement. The point spread function can be predefined or determined as part of a calibration step of the method according to the invention. Using the point spread function can achieve a more reliable classification.

[0051] According to at least one embodiment, to emit the light, the light is generated by means of at least one light source, in particular at least one laser light source, of the active optical sensor system and deflected by means of a deflection device of the active optical sensor by an angle in a scanning plane that is defined by a current position of the deflection device, in particular a current position at the time the generated light strikes the deflection device. The scanning plane is parallel to the plurality of rows of the array and perpendicular to the plurality of columns of the array. The active optical sensor system is thus designed in particular as a laser scanner. The deflection device can, as mentioned above, include a rotatably mounted mirror or a tiltable and / or inclinable microelectromechanical system (MEMS).During the emission of light, the deflection device can move, resulting in different azimuth angles in the scanning plane of the emitted light at different times and correspondingly different positions of the deflection device. Due to the magnitude of the speed of light, the instantaneous position when receiving the reflected portions is approximately identical to the instantaneous position when emitting the light. In this way, spatial resolution in the coordinate of the azimuth angle can be achieved, which can be further refined if necessary using the array's multiple columns.

[0052] Perpendicular to the scanning plane, the position of the deflection device or mirror can, for example, be constant, so that by changing the position of the deflection device, the surroundings are only scanned in the azimuth angle, not in the polar angle. For example, the emitted light can be widened perpendicular to the scanning plane, so that the surroundings are scanned in strips oriented parallel to the columns of the array. In other words, the detector pixels of one column or several adjacent columns are illuminated simultaneously. However, the detector pixels of different rows can be read out individually, so that a corresponding spatial resolution can also be achieved in the polar direction or in the polar angle direction by taking the row position into account.

[0053] According to at least one embodiment, the deflection device comprises a mirror mounted for rotation about an axis of rotation, wherein the axis of rotation is perpendicular to the scanning plane. The mirror has a first mirror surface arranged parallel to the axis of rotation and a second mirror surface arranged parallel to the axis of rotation.

[0054] The different mirror surfaces can, for example, be opposite mirror surfaces. In other words, the two mirror surfaces differ by a rotation of 180 degrees around the rotation axis. This can be the case, for example, with a polygonal mirror with four mirror surfaces or with a plate-shaped mirror with only two opposite mirror surfaces. However, the different mirror surfaces can also enclose a different angle with each other, in particular as respective side surfaces of a corresponding prism when the mirror is designed as a polygonal mirror with three, four, or more sides.

[0055] The first measuring cycle corresponds, for example, to a position of the mirror in which the light is deflected by the first mirror surface, in particular when emitting and when detecting the corresponding reflected portions of the light, and the second measuring cycle can, for example, correspond to a position of the mirror in which the light is deflected by the second mirror surface, in particular when transmitting and when receiving the corresponding reflected portions.

[0056] According to at least one embodiment, each detector pixel of the array comprises a plurality of single-photon detectors.

[0057] The single-photon detectors can, for example, be designed as SPADs, in other words as avalanche photodiodes, each operated in a Geiger mode.

[0058] According to at least one embodiment, the first measured value is determined depending on a number of triggered single-photon detectors of the first region and the second measured value is determined depending on a number of triggered single-photon detectors of the second region.

[0059] For example, the first measured value may correspond to an average number of triggered single-photon detectors in the first region and the second measured value may correspond to an average number of triggered single-photon detectors in the second region.

[0060] The fact that a single-photon detector is triggered can be understood to mean that the reception of a photon by the corresponding single-photon detector is detected. However, the single-photon detector generally cannot distinguish whether exactly one photon or several photons have fallen onto the respective single-photon detector in the current measurement cycle. However, because each detector pixel has several, in particular a large number, for example a sub-array, of single-photon detectors, the average number of triggered single-photon detectors is nevertheless a good measure of the energy input per detector pixel. According to at least one embodiment, each detector pixel of the array has a photodetector by means of which a detector signal is generated whose amplitude depends on a radiant power of the reflected portions of the emitted light incident on a detector surface of the respective photodetector.

[0061] According to at least one embodiment, the photodetectors, in particular all photodetectors of all detector pixels of the array, are designed as respective avalanche photodiodes, APDs, which are each operated below their breakdown voltage.

[0062] In particular, the photodetectors are not operated in Geiger mode, but as radiation power-proportional photodetectors.

[0063] According to at least one embodiment, the first measured value is determined depending on the respective sensor signals of the photodetectors of the detector pixels of the first region and the second measured value is determined depending on the respective sensor signals of the photodetectors of the detector pixels of the second region.

[0064] For example, the first measured value may correspond to an average radiant power per pixel of the first area and the second measured value may correspond to an average radiant power per pixel of the second area.

[0065] According to at least one embodiment, if the detection of the object is not classified as a false positive, a time of flight of those reflected portions of the emitted light received by the first region or a part of the first region or the second region or a part of the second region is determined. A distance of the object from the active optical sensor system is calculated based on the time of flight. In particular, a point cloud is generated based on the distance of the object.

[0066] If the object detection is classified as a false positive, the determination of the time of flight and / or the calculation of the distance can be omitted. Alternatively or additionally, the corresponding distance or time of flight can be omitted for generating the point cloud.

[0067] According to a further aspect of the invention, a method for at least partially automatically guiding a motor vehicle is provided. A method for identifying false-positive detections during operation of an active optical sensor system according to the invention is carried out using the active optical sensor system. By means of at least one computing unit, in particular at least one computing unit of the motor vehicle, at least one control signal for at least partially automatically guiding the motor vehicle is generated depending on the distance of the object from the active optical sensor system.

[0068] The at least one control signal can be transmitted, for example, to one or more actuators of the motor vehicle, including, for example, at least one brake actuator, at least one steering actuator, and / or at least one drive motor of the motor vehicle. The one or more actuators of the motor vehicle can then, depending on the at least one control signal, influence a lateral control and / or longitudinal control of the motor vehicle in order to steer the motor vehicle at least partially automatically. Alternatively or additionally, the at least one computing unit can, depending on the at least one control signal, generate one or more user outputs and output them to a user of the motor vehicle in order to assist the user in driving the motor vehicle.

[0069] The active optical sensor system can, in particular, be an active optical sensor system of the motor vehicle, i.e., mounted on the motor vehicle. However, it is also possible for the active optical sensor system to be part of an infrastructure facility and to be provided separately or externally to the motor vehicle.

[0070] A computing unit can be understood, in particular, as a data processing device that contains a processing circuit. The computing unit can therefore, in particular, process data to perform computing operations. This may also include operations for performing indexed access to a data structure, for example, a look-up table (LUT).

[0071] The computing unit may, in particular, contain one or more computers, one or more microcontrollers, and / or one or more integrated circuits, for example one or more application-specific integrated circuits (ASICs), one or more field-programmable gate arrays (FPGAs), and / or one or more single-chip systems (SoCs). The computing unit may also contain one or more processors, for example one or more microprocessors, one or more central processing units (CPUs), one or more graphics processing units (GPUs), and / or one or more signal processors, in particular one or more digital signal processors (DSPs). The computing unit may also include a physical or virtual network of computers or other of the aforementioned units.

[0072] In various embodiments, the computing unit includes one or more hardware and / or software interfaces and / or one or more memory units.

[0073] A memory unit can be a volatile data memory, for example a dynamic random access memory (DRAM) or a static random access memory (SRAM), or a non-volatile data memory, for example a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a flash memory or flash EEPROM, a ferroelectric random access memory (FRAM), a magnetoresistive random access memory,MRAM (magnetoresistive random access memory) or phase-change random access memory (PCRAM).

[0074] Further embodiments of the method according to the invention for the at least partially automatic driving of a motor vehicle follow directly from the various embodiments of the method according to the invention for identifying false-positive detections, and vice versa. In particular, individual features and corresponding explanations as well as advantages relating to the various embodiments of the method according to the invention for identifying false-positive detections can be transferred analogously to corresponding embodiments of the method according to the invention for the at least partially automatic driving of a motor vehicle.

[0075] For use cases or application situations that may arise during the method and which are not explicitly described here, it may be provided that, in accordance with the method, an error message and / or a request to enter user feedback is issued and / or a default setting and / or a predetermined initial state is set.

[0076] According to a further aspect of the invention, an active optical sensor system, in particular for a motor vehicle, is specified. The active optical sensor system comprises an evaluation unit, a transmitting device with at least one light source, and a detector unit having an array of detector pixels. The transmitting device is configured to emit light into an environment of the active optical sensor system. The array of detector pixels has a plurality of rows and a plurality of columns. The detector unit is configured to receive portions of the emitted light reflected in the environment.

[0077] The evaluation unit is configured to determine a first measured value relating to a first energy input per detector pixel of the detected reflected portions of the light by the evaluation unit reading out a first region of the array, which is an overlap region of at least one row of the array with a first set of columns of the array. The evaluation unit is configured to determine a second measured value relating to a second energy input per detector pixel of the detected reflected portions of the light by the evaluation unit reading out a second region of the array, which is an overlap region of the at least one row of the array with a second set of columns of the array. The second set of columns has at least one further column of the array that the first set of columns does not include.The evaluation unit is configured to classify a detection of an object in the environment, the position of which corresponds to the at least one line, as a false positive depending on the first measured value and the second measured value.

[0078] The active optical sensor system can, for example, have a control unit for controlling the at least one light source. The control unit can be part of the evaluation unit. The evaluation unit and / or the computing unit can be referred to as at least one further computing unit of the active optical sensor system.

[0079] The active optical sensor system can, for example, comprise a deflection device as described above. The control unit can be designed or configured to control the deflection device. Alternatively, the active optical sensor system can comprise a further control unit for controlling the deflection device.

[0080] According to at least one embodiment, the evaluation unit is configured to determine, if the detection of the object is not classified as false positive, a light propagation time of those reflected portions of the emitted light which are received by the first region or a part of the first region or the second region or a part of the second region, and to calculate a distance of the object from the active optical sensor system depending on the light propagation time.

[0081] Further embodiments of the active optical sensor system according to the invention follow directly from the various embodiments of the method according to the invention, and vice versa. In particular, individual features and corresponding explanations as well as advantages relating to the various embodiments of the method according to the invention can be transferred analogously to corresponding embodiments of the active optical sensor system according to the invention. In particular, the active optical sensor system according to the invention is designed or programmed to carry out a method according to the invention. In particular, the active optical sensor system according to the invention carries out a method according to the invention.

[0082] According to a further aspect of the invention, an electronic vehicle guidance system for a motor vehicle is provided. The electronic vehicle guidance system comprises an active optical sensor system according to the invention, as well as at least one computing unit configured to generate at least one control signal for at least partially automatically guiding the motor vehicle, depending on the distance of the object from the active optical sensor system.

[0083] An electronic vehicle guidance system can be understood as an electronic system designed to guide a vehicle fully automatically or autonomously, in particular without requiring driver intervention. The vehicle automatically performs all required functions, such as steering, braking, and / or acceleration maneuvers, monitoring and detecting road traffic, and corresponding reactions. In particular, the electronic vehicle guidance system can implement a fully automatic or fully autonomous driving mode of the motor vehicle according to level 5 of the SAE J3016 classification. An electronic vehicle guidance system can also be understood as an advanced driver assistance system (ADAS), which supports the driver in partially automated or semi-autonomous driving.In particular, the electronic vehicle guidance system can implement a partially automated or semi-autonomous driving mode according to levels 1 to 4 of the SAE J3016 classification. Here and below, "SAE J3016" refers to the corresponding standard in the April 2021 version.

[0084] Further features of the invention emerge from the claims, the figures and the description of the figures. The features and combinations of features mentioned above in the description as well as the features and combinations of features mentioned below in the description of the figures and / or shown in the figures can be encompassed by the invention not only in the respectively specified combination, but also in other combinations. In particular, the invention can also encompass embodiments and combinations of features that do not have all the features of an originally formulated claim. Furthermore, the invention can encompass embodiments and combinations of features that go beyond the combinations of features set out in the backreferences to the claims or deviate from them.

[0085] The invention is explained in more detail below using specific embodiments and associated schematic drawings. In the figures, identical or functionally equivalent elements may be provided with the same reference numerals. The description of identical or functionally equivalent elements may not necessarily be repeated for different figures.

[0086] The figures show:

[0087] Fig. 1 is a schematic representation of a motor vehicle with an exemplary embodiment of an electronic vehicle guidance system according to the invention;

[0088] Fig. 2 is a schematic block diagram of an exemplary embodiment of an active optical sensor system according to the invention; Fig. 3 is a schematic diagram of an exemplary embodiment of a method according to the invention for identifying false-positive detections;

[0089] Fig. 4 is a schematic representation of a point spread function of another exemplary embodiment of an active optical sensor system according to the invention;

[0090] Fig. 5 is a schematic representation of an array of detector pixels and their evaluation according to a further exemplary embodiment of a method according to the invention for identifying false-positive detections;

[0091] Fig. 6 is a schematic representation of an array of detector pixels and their evaluation according to a further exemplary embodiment of a method according to the invention for identifying false-positive detections;

[0092] Fig. 7 is a schematic representation of an array of detector pixels and their evaluation according to a further exemplary embodiment of a method according to the invention for identifying false-positive detections;

[0093] Fig. 8 is a schematic representation of an array of detector pixels and their evaluation according to a further exemplary embodiment of a method according to the invention for identifying false-positive detections;

[0094] Fig. 9 is a schematic representation of an array of detector pixels and their evaluation according to another exemplary embodiment of a method according to the invention for identifying false-positive detections; and

[0095] Fig. 10 is a schematic representation of an array of detector pixels and their evaluation according to a further exemplary embodiment of a method according to the invention for identifying false-positive detections.

[0096] Fig. 1 schematically shows a motor vehicle 1 which has an exemplary embodiment of an electronic vehicle guidance system 2 according to the invention.

[0097] The electronic vehicle guidance system 2 contains an exemplary embodiment of an active optical sensor system 3 according to the invention and at least one computing unit 24. The active optical sensor system 3 is configured to determine a distance of an object 4 in the surroundings of the motor vehicle 1, and the at least one computing unit 24 is configured to generate at least one control signal for at least partially automatically guiding the motor vehicle depending on the distance.

[0098] Fig. 2 shows a schematic block diagram of an exemplary embodiment of an active optical sensor system according to the invention, as can be used, for example, in the motor vehicle 1 of Fig. 1.

[0099] The active optical sensor system 3 has at least one light source 6, for example one or more laser diodes, by means of which light 5a can be emitted into the environment of the active optical sensor system 3. The active optical sensor system 3 also has a detector unit 9, which is configured to receive components 5b of the emitted light 5a reflected in the environment, for example components 5b reflected by the object 4. The active optical sensor system 3 also has a control and evaluation unit 10, which can control the at least one light source 6 to emit or generate the light 5a and can receive corresponding sensor signals from the detector unit 9. The detector unit 9 has an array 17 (see Fig. 5 to Fig. 10) with a plurality of rows and a plurality of columns.

[0100] The control and evaluation unit 10 is configured to detect one or more objects 4 in the environment depending on the detected or received reflected portions 5b of the emitted light 5a and to classify the detection of the objects 4 as false positive or true positive. The control and evaluation unit 10 or the at least one computing unit 24 can generate a point cloud based on the true positive classified detections, wherein each point contains a corresponding three-dimensional position of the respective object 4 in the environment. A distance, in particular a radial distance, of the object 4 is calculated in particular based on a time-of-flight measurement. An azimuth angle and a polar angle of the objects 4 are each determined based on the corresponding position of the detection on the array 17. The array 17 is arranged in particular in an xz plane.

[0101] In the example of Fig. 2, the active optical sensor system 3 is configured, for example, as a laser scanner. The active optical sensor system 3 then has a deflection device with a rotatable mirror 7 mounted about a rotation axis 8 oriented parallel to a z-axis. The mirror 7 can be controlled by the control and evaluation unit 10 and thus set in rotation so that the emitted light 5a can scan the surroundings in the xy plane. The azimuth angle, i.e., the corresponding angle in the xy plane, can be determined based on the position of the corresponding detection on the array 17 and the associated current position of the mirror 7.

[0102] To classify the detection of an object 4 as false positive or true positive, the active optical sensor system 3 can perform a method according to the invention for identifying false positive detections.

[0103] Various embodiments of such a method according to the invention are explained in more detail with reference to Fig. 3 to Fig. 10. According to the method, a first measured value relating to a first energy input per detector pixel of the detected reflected portions 5b is determined by reading out a first region 20, 22 of the array 17, which is an overlap region of at least one row 12, 13 of the array 17 with a first set of columns 14 of the array 17. A second measured value relating to a second energy input per detector pixel of the detected reflected portions 5b is determined by reading out a second region 21, 23 of the array, which is an overlap region of the at least one row 12, 13 with a second set of columns 15 of the array.

[0104] The second set of columns 15 comprises at least one additional column of the array, which the first set of columns 14 does not include. The detection of the respective object 14 in the environment corresponding to the respective at least one row 12, 13 is classified as false positive or true positive depending on the first measured value and the second measured value.

[0105] Fig. 4 schematically shows a point spread function 16 of the active optical sensor system 3. In the center, the point spread function 16 has a maximum value and the point spread function 16 decreases rapidly and sharply towards the outside in an approximately radially symmetric manner. The point spread function 16 determines the deviation of the image of an object 4 on the array 14 from an optimal image. In particular, the point spread function 16 defines the distribution with which a point light source at an infinite distance would be imaged on the array 17. The optical components in the reception path of the active optical sensor system, for example, an entrance and exit window for the light 5a, 5b, the mirror 7, a reception optics, and so on, contribute to the characteristics of the point spread function 16. The convolution of the actual light sources with the point spread function 16 results in the actual image on the array 17.However, this means that an image of an object 4 with very high reflectivity is not only limited to the projected object size on the array, but the image is smeared on the array in a manner defined by the point spread function 16.

[0106] The at least one light source 6 contains, for example, one or more laser diodes extended in the z-direction, so that the emitted light 5a is emitted in the form of a stripe along the z-direction, but with a very sharply defined intensity distribution in the xy plane. The intensity distribution can, for example, be limited to an azimuth angle range of 0.1 degrees or less. Accordingly, the reflected portions 5b of the light 5a also impinge on the array 17 as a stripe 18, which can extend over a plurality of rows of the array 17. With diffuse reflectors, the stripe 18 on the array 17 is comparatively narrow, so that it only falls on one column, for example, as schematically shown in Figures 5, 7, 9, and 10. With highly reflective objects 4, the stripe 18 is wider and can cover two or more columns, as schematically shown in Figures 6 and 8.Below the arrays 17 in the figures Fig. 5 to Fig. 10, the typical intensity distribution 19 over several columns is shown schematically.

[0107] In Fig. 3, based on the approximately radially symmetric point spread function 16, several concentric circles are shown, which accordingly define concentric annular regions 11a, 11b, 11c, 11d and a circular region 11e located in the center, which is also concentric therewith. For the sake of simplicity of explanation, it is assumed that the energy input per pixel is constant in each of the regions 11a to 11e. If it is assumed that a positive detection occurs in the center, i.e., in region 11e, it can be assumed, for example, that the energy input per detector pixel in region 11e is maximum and greater than the energy input per detector pixel in the subsequent region 11d, which in turn is greater than the energy input per detector pixel in the subsequent region 11c, and so on, until the minimum energy input per detector pixel is present in the outermost region 11a.

[0108] Fig. 3 shows the pixels of two different rows 12, 13, each with five columns. Row 12 runs through the center and the central region 11e. For example, the outermost pixels 12a, 12e of row 12 lie in region 11c, pixels 12b and 12d of row 12 lie in region 11d, and pixel 12c of row 12 lies in region 11e. Row 13 is shifted downward from the center so that all five pixels 13a to 13e lie in the outermost region 11a. Therefore, if a detection is identified for one of the pixels 12a to 12e, this corresponds to a true positive detection, whereas a detection identified for pixels 13a to 13e is a false positive detection.

[0109] To simplify the discussion, it is assumed below that the energy input per detector pixel is 1 in region 11a, 2 in region 11b, 3 in region 11c, 4 in region 11d, and 1 in region 11e. The units of energy input are arbitrary. For example, if the detector pixels are configured such that they each have multiple SPADs, the energy input can correspond to the average triggered SPADs per detector pixel.

[0110] Let us first consider row 12. The first region 20 is then formed, for example, by the three pixels 12b, 12c, 12d, whereas the second region 21 is formed by all five pixels 12a, 12b, 12c, 12d, 2e. In the numerical example given, the first measured value would then be (5 + 4 + 4) / 3 = 4.3, whereas the second measured value would be given by (5 + 4 + 4 + 3 + 3) / 5 = 3.8. In other words, the first measured value differs significantly from the second measured value. Based on the ratio of the first measured value to the second measured value or on the difference between the first measured value and the second measured value, the detection in the corresponding region of row 12 can therefore be classified as a true positive. If we now consider row 13, the first area 22 corresponds to the detector pixels 13b, 13c, 13d and the second area 23 corresponds to all five detector pixels 13a, 13b, 13c, 13d, 13e.In the above numerical example, the first measured value would then be given by (1 + 1 + 1 ) / 3 = 1, and the second measured value would also be (1 + 1 + 1 + 1 + 1 ) / 5 = 1. Therefore, the first measured value and the second measured value are equal in this case. Based on the ratio of the first measured value to the second measured value or the difference between the first and second measured values, the detection can be classified as a false positive according to line 13.

[0111] It can therefore be used for classification purposes that the laser power drops sharply along the x-direction in the case of a true-positive detection, but remains approximately the same in the case of a false-positive detection.

[0112] The further the corresponding detector pixels are located vertically, i.e., in the z-direction, from the position corresponding to the real object 4, the more homogeneous the intensity distribution on the array 17 is in the horizontal direction, i.e., the x-direction. In contrast to a true-positive measurement, a measurement with two reception areas 14, 15 with different horizontal extensions yields approximately equal measured values ​​with respect to the energy input per detector pixel, as shown in Fig. 5 and Fig. 6. Instead of changing the width of the reception areas 14, 15 for the different measurements, the second reception area 15 can also be shifted in the x-direction relative to the first reception area 14, as shown in Fig. 7 and Fig. 8.Here, too, in the case of a false-positive measurement, the second measured value would hardly differ from the first, whereas in the case of a true-positive detection, there would be a significant difference between the second measured value and the first measured value. This is shown schematically in Fig. 7 and Fig. 8.

[0113] It is also possible for the reception areas 14, 15 to have different widths and be laterally offset from one another in the x-direction, as shown in Fig. 10. In the examples in Fig. 9 and Fig. 10, the reception areas 14, 15 do not overlap. In the example in Fig. 9, they are adjacent to one another; in the example in Fig. 10, they are spaced apart. In such embodiments, both the first measured value and the second measured value can be determined within a single measurement cycle, if necessary.

[0114] As described, in particular with regard to the figures, the invention makes it possible to identify false-positive detections more reliably as such by exploiting the different homogeneity of the intensity distribution on the detector array in false-positive and true-positive detections.

Claims

Patent claims 1. A method for identifying false-positive detections during operation of an active optical sensor system (3), wherein light (5a) is emitted into an environment of the active optical sensor system (3) by means of the active optical sensor system (3); portions (5b) of the emitted light (5a) reflected in the environment are received by means of a detector unit (9) of the active optical sensor system (3), which has an array (17) of detector pixels (12a, 12b, 12c, 12d, 12e, 13a, 13b, 13c, 13d, 13e) with a plurality of rows and a plurality of columns;characterized in that a first measured value relating to a first energy input per detector pixel (12a, 12b, 12c, 12d, 12e, 13a, 13b, 13c, 13d, 13e) of the detected reflected portions (5b) of the light (5a) is determined by reading out a first region (20, 22) of the array (17), which is an overlap region of at least one row (12, 13) of the array (17) with a first set of columns (14) of the array (17); a second measured value relating to a second energy input per detector pixel (12a, 12b, 12c, 12d, 12e, 13a, 13b, 13c, 13d, 13e) of the detected reflected portions (5b) of the light (5a) is determined by reading out a second region (21, 23) of the array (17), which is an overlap region of the at least one row (12, 13) of the array (17) with a second set of columns (15) of the array (17);the second set of columns (15) includes at least one further column of the array (17) that the first set of columns (14) does not include; and a detection of an object (4) in the environment whose position corresponds to the at least one row (12, 13) is classified as a false positive depending on the first measured value and the second measured value.

2. Method according to claim 1, characterized in that the detection of the object (4) is classified as false positive depending on a ratio of the second measured value to the first measured value or depending on a difference between the first measured value and the second measured value.

3. Method according to claim 2, characterized in that the detection of the object (4) is classified as false positive if the ratio of the second measured value to the first measured value is smaller than a predetermined limit value or if the difference between the first measured value and the second measured value is smaller than a predetermined further limit value.

4. Method according to one of the preceding claims, characterized in that the at least one further column comprises a first further column following the first set of columns (14); and / or the at least one further column comprises a second further column following the first set (14) of columns.

5. Method according to one of the preceding claims, characterized in that the second set of columns (15) contains all columns of the first set of columns (15).

6. Method according to one of claims 1 to 4, characterized in that the second set of columns (15) does not contain any column of the first set of columns (14).

7. Method according to one of the preceding claims, characterized in that the first measured value is determined by reading the first area in a measuring cycle and the second measured value is determined by reading the second area in the measuring cycle; or the first measured value is determined by reading the first range in a first measuring cycle and the second measured value is determined by reading the second range in a second measuring cycle which is before or after the first measuring cycle.

8. Method according to one of the preceding claims, characterized in that the detection of the object (4) is classified as false positive depending on a point spread function (16) of the active optical sensor system (3).

9. Method according to one of the preceding claims, characterized in that for emitting the light (5a), the light (5a) is generated by means of at least one light source (6) of the active optical sensor system (3) and is deflected by means of a deflection device (7, 8) of the active optical sensor system (3) by an angle in a scanning plane which is defined by a current position of the deflection device (7, 8), the scanning plane being parallel to the plurality of rows of the array (17) and perpendicular to the plurality of columns of the array (17).

10. The method according to claim 7 and claim 9, characterized in that the deflection device (7, 8) comprises a mirror (7) which is rotatably mounted about an axis of rotation (8) which is perpendicular to the scanning plane; the mirror (7) has a first mirror surface arranged parallel to the axis of rotation (8) and a second mirror surface arranged parallel to the axis of rotation (8); the first measuring cycle corresponds to a position of the mirror (7) in which the light (5a) is deflected by the first mirror surface and the second measuring cycle corresponds to a position of the mirror (7) in which the light (5a) is deflected by the second mirror surface. 11 . Method according to one of the preceding claims, characterized in that each detector pixel (12a, 12b, 12c, 12d, 12e, 13a, 13b, 13c, 13d, 13e) of the array (17) contains a plurality of single-photon detectors; the first measured value is determined as a function of a number of triggered single-photon detectors of the first region (20, 22); and the second measured value is determined as a function of a number of triggered single-photon detectors of the second region (21, 23).

12. The method according to claim 11, characterized in that the single-photon detectors are designed as avalanche photodiodes, each operated in a Geiger mode.

13. The method according to one of claims 1 to 10, characterized in that each detector pixel (12a, 12b, 12c, 12d, 12e, 13a, 13b, 13c, 13d, 13e) of the array (17) contains a photodetector by means of which a detector signal is generated, the amplitude of which depends on a radiation power of the reflected portions (5b) of the emitted light (5a) incident on a detector surface of the respective photodetector; the first measured value is determined as a function of the respective sensor signals of the photodetectors of the detector pixels (12a, 12b, 12c, 12d, 12e, 13a, 13b, 13c, 13d, 13e) of the first region (20, 22); and the second measured value is determined as a function of the respective sensor signals of the photodetectors of the detector pixels (12a, 12b, 12c, 12d, 12e, 13a, 13b, 13c, 13d, 13e) of the second region (21, 23).

14. Method according to claim 13, characterized in that the photodetectors are designed as avalanche photodiodes, each of which is operated below its breakdown voltage.

15. Method according to one of the preceding claims, characterized in that if the detection of the object (4) is not classified as false positive, a light propagation time of those reflected portions (5b) of the emitted light (5a) which received from the first region (20, 22) or a part of the first region (20, 22) or the second region (21, 23) or a part of the second region (21, 23); and a distance of the object (4) from the active optical sensor system (3) is calculated as a function of the light travel time.

16. A method for at least partially automatically driving a motor vehicle (1), wherein a method according to claim 15 is carried out by means of an active optical sensor system (3) and at least one control signal for at least partially automatically driving the motor vehicle (1) is generated by means of at least one computing unit (24) as a function of the distance.

17. Active optical sensor system (3) comprising an evaluation unit (10), and a transmitting device with at least one light source (6) which is designed to emit light (5a) into an environment of the active optical sensor system (3); a detector unit (9) which has an array (17) of detector pixels (12a, 12b, 12c, 12d, 12e, 13a, 13b, 13c, 13d, 13e) having a plurality of rows and a plurality of columns, which is adapted to receive portions (5b) of the emitted light (5a) reflected in the environment; characterized in that the evaluation unit (10) is configured to determine a first measured value relating to a first energy input per detector pixel (12a, 12b, 12c, 12d, 12e, 13a, 13b, 13c, 13d, 13e) of the detected reflected portions (5b) of the light (5a) by reading out a first region (20, 22) of the array (17), which is an overlap region of at least one row (12, 13) of the array (17) with a first set of columns (14) of the array (17);to determine a second measured value relating to a second energy input per detector pixel (12a, 12b, 12c, 12d, 12e, 13a, 13b, 13c, 13d, 13e) of the detected reflected portions (5b) of the light (5a) by reading out a second region (21, 23) of the array (17), which is an overlap region of the at least one row (12, 13) of the array (17) with a second set of columns (15) of the array (17), wherein the second set of columns (15) includes at least one further column of the array (17) which the first set of columns (14) does not include; and; to classify a detection of an object (4) in the environment, the position of which corresponds to the at least one line (12, 13), as a false positive depending on the first measured value and the second measured value.

18. Active optical sensor system (3) according to claim 17, characterized in that the evaluation unit (10) is configured, if the detection of the object (4) is not classified as a false positive, to determine a light propagation time of those reflected portions (5b) of the emitted light (5a) which are received by the first region (20, 22) or a part of the first region (20, 22) or the second region (21, 23) or a part of the second region (21, 23), and to calculate a distance of the object (4) from the active optical sensor system (3) depending on the light propagation time. 19.Electronic vehicle guidance system (2) for a motor vehicle (1), comprising an active optical sensor system (3) according to claim 18 and at least one computing unit (24) which is designed to generate at least one control signal for at least partially automatically guiding the motor vehicle (1) as a function of the distance.

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