Method for correcting crosstalk effects between pixels of an optical receiving device, in particular a LiDAR system of a vehicle

Abstract

A method is described for correcting crosstalk effects between pixels (50 E , 50 K ) of a pixel field (48) of an optical receiving device, which, when detecting light signals from a monitoring area of ​​the optical receiving device, is equipped with receiving pixels (50) for detecting light signals E ) used pixels can occur. In the method, at least one correction pixel signal is acquired, which is used with at least one correction pixel (50 K ) during at least one reception sequence with the receiving device, wherein correction pixels (50 K ) pixels that are not used for detecting light signals. At least one received pixel signal is detected, which corresponds to at least one of the received pixels (50 E) is generated. At least one of the received pixel signals is corrected using at least one of the correction pixel signals. At least one section of the monitored area is mapped onto the pixel array (48), and at least one area of ​​the pixel array (48), onto which the section of the monitored area (18) is mapped, is used as the received area (56) within the pixel array (48) for receiving light signals, and the pixels within the received area (56) are designated as received pixels (50). E ) is used and the pixels outside the reception area (56) are used as correction pixels (50) K ) used.

Description

Technical field

[0001] The invention relates to a method for correcting crosstalk effects between pixels of a pixel field of an optical receiving device, in particular an optical receiving device of a LiDAR system, especially an optical receiving device of a LiDAR system of a vehicle, which can occur when detecting light signals from a monitoring area of ​​the optical receiving device with pixels of the pixel field used as receiving pixels for detecting light signals, wherein in the method at least one correction pixel signal is detected, which is generated with at least one correction pixel during at least one reception sequence with the receiving device, wherein correction pixels are pixels of the pixel field that are not used for the detection of light signals, at least one received pixel signal is captured, which is generated with at least one of the received pixels, at least one of the received pixel signals is corrected using at least one of the correction pixel signals.

[0002] Furthermore, the invention relates to a means which is designed to carry out a method for correcting crosstalk effects between pixels of a pixel field of an optical receiving device, in particular an optical receiving device of a LiDAR system, in particular an optical receiving device of a LiDAR system of a vehicle, which may occur when detecting light signals with pixels of the pixel field used as receiving pixels for detecting light signals.

[0003] Furthermore, the invention relates to an optical receiving device, in particular an optical receiving device of a LiDAR system, in particular an optical receiving device of a LiDAR system of a vehicle, with at least one pixel field which has at least two pixels which are configured for use as receiving pixels for detecting light signals, and which has at least one pixel which is configured for use as a correction pixel with which no light signals are detected, and with at least one part of a means for carrying out a method for correcting crosstalk effects between receiving pixels of the pixel field, which may occur when detecting light signals with the receiving pixels.

[0004] Furthermore, the invention relates to a LiDAR system, in particular a LiDAR system for a vehicle, comprising at least one optical transmitter for transmitting scanning light signals into at least one monitoring area, at least one optical receiver for receiving echo light signals originating from the at least one monitoring area and resulting from scanning light signals reflected in the monitoring area, at least one control unit for controlling the functions of the LiDAR system, and at least part of a means for carrying out a method for correcting crosstalk effects between receiving pixels of the at least one optical receiver that may occur when detecting light signals with the receiving pixels, wherein the at least one optical receiver comprises at least one pixel array having at least two pixels.which are designed for use as receiving pixels for detecting light signals, and have at least one pixel designed for use as a correction pixel, with which no light signals are detected.

[0005] Furthermore, the invention relates to a driver assistance system with at least one optical receiving device, in particular at least one optical receiving device according to the invention, in particular at least one optical receiving device of at least one LiDAR system, in particular at least one LiDAR system according to the invention, with at least one control unit and with at least one part of a means for carrying out a method for correcting crosstalk effects between receiving pixels of the at least one optical receiving device, which may occur when light signals are detected by the receiving pixels.

[0006] Furthermore, the invention relates to a vehicle with at least one optical receiving device, in particular at least one optical receiving device according to the invention, in particular at least one optical receiving device of at least one LiDAR system, in particular at least one LiDAR system according to the invention, and at least part of a means for carrying out a method for correcting crosstalk effects between receiving pixels of the at least one optical receiving device, which may occur when light signals are detected by the receiving pixels. State of the art

[0007] From US patent 20230003859 A1, a single-photon counting sensor arrangement is known, comprising one or more emitters configured to emit a plurality of energy pulses, and a detector arrangement comprising a plurality of pixels. Each pixel contains one or more detectors, several of which are configured to receive reflected energy pulses emitted by the one or more emitters. A mask material is positioned to cover some, but not all, of the detectors of the plurality of pixels, thus creating locked and unlocked pixels. Each locked pixel is prevented from detecting the reflected energy pulses and therefore detects only its own noise.

[0008] The invention is based on the objective of designing a method, a means, a receiving device, a LiDAR system, a driver assistance system and a vehicle of the type mentioned at the outset, in which crosstalk effects between pixels of the pixel field can be corrected better, in particular with less effort and / or more efficiently. Disclosure of the invention

[0009] The object of the invention is achieved in the method by mapping at least one section of the monitoring area onto the pixel field and by using at least one area of ​​the pixel field, onto which the at least one section of the monitoring area is mapped, as at least one receiving area within the pixel field for receiving light signals. and the pixels of the pixel field within the at least one reception area are used as reception pixels and the pixels of the pixel field outside the at least one reception area are used as correction pixels.

[0010] According to the invention, the pixels of the pixel array are used as receiving pixels or correction pixels depending on whether they lie within the receiving area of ​​the pixel array. The receiving area of ​​the pixel array is defined by at least one section of the monitoring area. The pixels that lie within the receiving area defined by the section of the monitoring area are used as receiving pixels. The pixels that lie outside the receiving area are used as correction pixels.

[0011] At least one section of the monitored area is mapped onto the pixel array. For each line, and in particular for each line emanating from the pixel array and entering the monitored area, an associated location, specifically a receiving pixel, of the pixel array is defined.

[0012] Depending on the optical receiving device, particularly its design and / or operation, the at least one section may coincide with or constitute the monitoring area. If the optical receiving device, especially the receiving device of a LiDAR system, is a non-scanning receiving device, the at least one section may coincide with or constitute the monitoring area. In the case of a scanning receiving device, the monitoring area may consist of a plurality of overlapping or non-overlapping sections.

[0013] Advantageously, the imaging and thus the definition of the receiving pixels can be achieved on the receiving device using imaging components, such as optical components, in particular lenses, objectives, deflecting mirrors, or the like. Using these imaging components, at least one section of the monitored area can be mapped onto the pixel array. The dimensions of this section in the plane of the pixel array define the dimensions of the at least one receiving area for receiving light signals.

[0014] The at least one receiving area of ​​the pixel array is the area onto which, particularly with the aid of imaging components, the light signals coming from the at least one section of the monitoring area can be mapped. The receiving area is the area in which reception of light signals is fundamentally possible. By mapping the at least one section of the monitoring area exclusively onto the receiving area, it is prevented that light signals can reach correction pixels outside the receiving area. The correction pixel signals can only originate from noise, crosstalk effects such as blooming, or the like. In the case that no crosstalk effects or the like occur between the pixels, no signal is generated by the correction pixels that could originate from a light signal directly reaching the correction pixels.

[0015] For clarity, the terms "noise" and "crosstalk" are used separately within the meaning of the invention. When "noise" is mentioned in this description of the invention, it refers to interference effects that are not caused by crosstalk.

[0016] For easier differentiation, signals generated by correction pixels are referred to as "correction pixel signals." Signals generated by receive pixels, on the other hand, are referred to as "receive pixel signals."

[0017] The received pixel signals of received pixels can originate from noise, crosstalk effects such as blooming or the like, and additionally from light signals that hit the respective received pixels.

[0018] Advantageously, the received pixel signals can characterize the intensity of the light signals received by the corresponding received pixels. In this way, the received pixel signals can indicate the received light energy.

[0019] Advantageously, the received pixel signals can indicate the number of photons of the light signals striking the respective receiving pixels. In this way, a measure of the received light energy can be specified.

[0020] Advantageously, the correction pixel signals and the receiving pixel signals can include or consist of numerical values. The numerical values ​​of the receiving pixel signals can be a measure of the intensities of the incident light signals.

[0021] Advantageously, the correction pixel signals and / or the received pixel signals can be digitized signals. This allows the correction pixel signals and / or the received pixel signals to be processed using digital processing equipment, especially processors.

[0022] The invention thus enables the correction of crosstalk effects based on correction pixel signals from correction pixels located outside the reception area. The pixels designated as correction pixels are not masked. In this way, it is not necessary to mask individual pixels to use them as correction pixels, as is required in the prior art single-photon counting sensor arrangement. The method according to the invention can be implemented with simpler means and therefore with less effort.

[0023] The prior art method of pixel masking prevents the pixels from being used as receiving pixels. This makes it impossible to vary the receiving area on the pixel array. Consequently, it is also impossible to compensate for any mounting tolerances of the pixel array in the receiver device, which could result in a shift in the image of at least one section of the monitored area. The invention addresses this by allowing the receiving area to be freely selected across the pixel array.

[0024] Furthermore, the method according to the invention has the advantage that a homogeneous pixel array can be used. A homogeneous pixel array is easier to implement than a pixel array in which masked and unmasked pixels are provided on the one hand. Thus, the method according to the invention makes it possible to use simpler and less expensive pixel arrays.

[0025] Blooming is caused by a mixing of signals between pixels. In a LiDAR system where a surveillance area is scanned only horizontally, blooming effects can occur primarily in pixels that are vertically adjacent to pixels struck by light signals. This can lead to objects detected by the optical receiver, especially the optical receiver of the LiDAR system, being perceived as larger, with incorrect amplitude and distance values.

[0026] Blooming can occur when highly reflective objects, especially retroreflective ones, are detected by an optical receiver. In this case, the light signals reflected from the highly reflective object can be so strong that individual pixels can become oversaturated. Additionally, all internal light reflections and crosstalk effects within the receiver can increase and exceed the noise level. These crosstalk effects can be so significant that the receiver mistakenly identifies them as a real object. Thus, a "ghost object" at the same distance as the real, highly reflective object can be detected by the receiver, thereby blocking the acquisition of information from lower-intensity objects in the vicinity of the highly reflective real object.

[0027] Advantageously, at least one contiguous section of the monitored area can be mapped onto the pixel array. In this way, all lines within the monitored area can be mapped onto the pixel array.

[0028] Advantageously, this method can be used in conjunction with an optical receiver of a LiDAR (Light Detection and Ranging) system. This allows the distances and / or directions of objects within the LiDAR system's monitoring area to be determined.

[0029] Advantageously, the LiDAR system can be designed as a scanning system. In this configuration, a monitoring area can be scanned using scanning light signals. The direction of propagation of these light signals can be swept across the monitoring area. At least one signal deflection device, in particular a scanning device, a deflection mirror device, or similar, can be used for this purpose. Alternatively, the LiDAR system can be designed as a so-called flash LiDAR system. In this case, corresponding scanning light signals can simultaneously illuminate a larger portion or the entire monitoring area. The monitoring area can then be scanned in sections at the receiving device.

[0030] "Optical" within the meaning of the invention refers to visible and invisible ranges of electromagnetic radiation, in particular light radiation. The components designated as "optical" are accordingly suitable for use in connection with electromagnetic radiation ranges visible and invisible to humans. Optical components may be optical lenses, electro-optical components such as light sources or sensors, or other components that have at least one optical effect or function, or a combination of such components.

[0031] The invention can be used in vehicles. A key functional characteristic of a vehicle is its ability to move. Vehicles can be motor vehicles. Advantageously, the invention can be used in land vehicles, in particular cars, trucks, buses, motorized or non-motorized two-wheelers such as motorcycles, e-bikes, bicycles, or the like, drones, mobile robots, mobile machinery, in particular construction or transport machinery such as cranes, excavators, or the like, aircraft, in particular drones, and / or (under)water vehicles, in particular (under)water drones. The invention can also be used in vehicles that can be operated autonomously or semi-autonomously. However, the invention is not limited to vehicles. It can also be used in stationary operation.

[0032] In an advantageous embodiment of the method, it can first be checked whether there are indications of crosstalk effects. If so, at least one of the received pixel signals can be corrected using at least one of the correction pixel signals; otherwise, no correction of the at least one received pixel signal is performed. In this way, the correction is only carried out if it is necessary due to existing crosstalk effects.

[0033] Indications of crosstalk effects can include exceeding threshold values ​​for received pixel signals, detecting oversaturation of received pixels and / or exceeding noise threshold values ​​for correction pixel signals.

[0034] In a further advantageous embodiment of the method, it can first be checked whether at least one of the correction pixel signals exceeds a predetermined noise threshold, in particular whether the correction pixel signals of several correction pixels each exceed a predetermined noise threshold, and / or whether at least one received pixel signal exceeds a predetermined limit threshold and / or whether at least one of the received pixels is oversaturated, provided that at least one of the correction pixel signals, in particular the correction pixel signals of several correction pixels, exceeds the respective noise threshold, and / or provided that at least one of the received pixel signals exceeds the predetermined limit threshold and / or provided that at least one of the received pixels is oversaturated.At least one of the received pixel signals can be corrected using at least one of the correction pixel signals; otherwise, no correction of the at least one received pixel signal is carried out.

[0035] In this way, the correction is only performed if there are indications of crosstalk effects. This can accelerate the provision of information acquired by the optical receiving device. To check for the presence of crosstalk effects, it may be sufficient to perform only one of the three test options according to the invention. Alternatively, several or all of the three test options can be performed.

[0036] If the light signals reaching the receiving pixels are reflected by objects in the monitored area, their intensity depends on both the original intensity and the reflectivity of the reflecting object. Highly reflective objects, especially retroreflective ones, reflect light signals with minimal loss. Consequently, the intensity of the light signals reaching the receiving pixels is correspondingly high. This can lead to oversaturation of the corresponding receiving pixels and / or crosstalk effects in other pixels, particularly receiving pixels and correction pixels.

[0037] When comparing signals, in particular correction pixel signals and received pixel signals, with corresponding threshold values, especially noise threshold values ​​or limit threshold values, at least one signal value of the corresponding signal of the respective pixel can be compared with the corresponding threshold value. The signal value of a signal can be a numerical value or the value of a physical quantity, in particular an electrical quantity.

[0038] Advantageously, to decide whether crosstalk correction is necessary, it can first be checked whether at least one of the correction pixel signals is larger than a predefined noise threshold. In this way, the actual presence of crosstalk in correction pixels can be detected.

[0039] The noise threshold can be individually set for the receiving device, and optionally the LiDAR system. This noise threshold takes into account the noise component generated during operation of the receiving device, and optionally the LiDAR system, without crosstalk and without the influence of light signals.

[0040] If a correction pixel signal from one of the correction pixels exceeds the noise threshold, it can be assumed that the correction pixel signal has been amplified by crosstalk effects, since the correction pixel is located outside the at least one receiving area and is therefore not affected by light signals. It can thus be assumed that crosstalk effects originate from receiving pixels affected by light signals in the corresponding receiving sequence. These crosstalk effects can affect not only the correction pixel whose correction pixel signal exceeds the noise threshold, but also receiving pixels within the receiving area.

[0041] Advantageously, it is possible to check whether the correction pixel signals of several correction pixels each exceed a predefined noise threshold. This improves the accuracy of assessing whether crosstalk effects occur.

[0042] Advantageously, the same noise threshold can be used for all correction pixels whose correction pixel signals are compared to the noise threshold. This eliminates the need to store multiple noise thresholds. Alternatively, an individual noise threshold can be used for each correction pixel. This improves the accuracy of crosstalk detection.

[0043] Alternatively or additionally, to decide whether crosstalk correction is necessary, it can be checked whether at least one received pixel signal exceeds a predefined threshold value. In this way, the presence of crosstalk can be inferred from the received pixel signals.

[0044] The threshold value can be individually defined for the receiving device, and if applicable, the LiDAR system. The threshold value can be defined, in particular, based on test measurements. The threshold value can be set such that, for received pixel signals above the threshold value, it is highly probable or certain that crosstalk effects will emanate from the corresponding received pixel.

[0045] Alternatively or additionally, to decide whether crosstalk correction is necessary, it can be checked whether at least one of the receiving pixels is oversaturated. This allows for a very efficient test of whether the conditions for crosstalk are present. Extensive tests have shown that if one receiving pixel is oversaturated, crosstalk effects are generated in neighboring pixels.

[0046] Depending on the test options used, if it is detected that at least one of the correction pixel signals is greater than the noise threshold, and / or at least one of the receive pixel signals is greater than the specified limit threshold, and / or at least one of the receive pixels is oversaturated, then the at least one receive pixel signal of the at least one receive pixel can be corrected using at least one of the correction pixel signals, in particular at least one of the correction pixel signals that exceeds the noise threshold. Otherwise, no correction is performed.

[0047] In a further advantageous embodiment, it can be checked whether at least one of the correction pixel signals, or in particular several correction pixels, in the immediate vicinity of the at least one receiving area exceeds the predetermined noise threshold. In this way, even small crosstalk effects can be detected. The effect of crosstalk decreases with increasing distance between the correction pixel under consideration and the receiving pixel that causes it.

[0048] In a further advantageous embodiment of the method, the at least one received pixel signal can be reduced for correction by a value based on at least one of the correction pixel signals, in particular an average of several correction pixel signals. In this way, the received pixel signals can be corrected quickly, efficiently, and with simple means.

[0049] The correction of the at least one received pixel signal can be performed using an algorithm. In this way, the at least one received pixel signal can be corrected, in particular, by software, especially with a processor.

[0050] Advantageously, a value based on at least one of the correction pixel signals can be subtracted from a value of the at least one received pixel signal. In this way, at least one corrected received pixel signal can be easily calculated.

[0051] In a further advantageous embodiment of the method, the crosstalk correction procedure can be performed before target detections of objects from which the captured light signals originate are determined based on the received pixel signals, and in particular, based on the corrected received pixel signals. In this way, crosstalk effects can be corrected at an early processing stage. This allows a greater information content of the received pixel signals to be retained. The crosstalk correction procedure can even be used to correct the raw data.

[0052] The corrected received pixel signals can be further processed to determine the detection of targets from which the detected light signals originate. These detections can be specified by data sets containing the direction and distance of the detected targets relative to the receiving device. Furthermore, the detections can include information about the intensity of the light signals emanating from the detected targets. The reflectivity of each target can be inferred from this intensity.

[0053] Target detections can be processed into point clouds. These point clouds characterize the situation within the monitored area, as captured by the optical receiver, with regard to the objects present there.

[0054] Targets are points on an object where light signals can be reflected. When using the receiver in a LiDAR system, scan light signals transmitted by the LiDAR system's transmitter into a monitoring area can be reflected from targets. Light signals reflected towards the receiver are directed, provided the target is located within at least one section of the monitoring area, into the corresponding at least one receiving area of ​​the pixel array and can be received by the corresponding receiving pixels. Typically, an object has multiple targets where light signals can be reflected.

[0055] In a further advantageous embodiment of the method, the procedure for correcting crosstalk effects can be carried out in real time, in particular immediately after the generation of received pixel signals and correction pixel signals. In this way, the received pixel signals generated by the receiving device can be processed more quickly, and information about the monitored area, especially about objects within the monitored area, can be obtained.

[0056] By using an optical receiving device, particularly a LiDAR system, a vehicle can transmit information about its surroundings to a driver assistance system more quickly. This further improves autonomous or semi-autonomous vehicle operation and, in particular, enhances the vehicle's operational safety.

[0057] In a further advantageous embodiment of the method, the raw data generated by the receiving pixels and the correction pixels can be used as receiving pixel signals or as correction pixel signals. In this way, the method can be carried out directly on the basis of the raw data without prior data processing. Corrections can thus be made in an early processing phase.

[0058] In a further advantageous embodiment of the method, the received pixel signals of several received pixels, in particular all received pixels, of the receiving area can be corrected using the correction pixel signals of at least one of the correction pixels, in particular several correction pixels. In this way, more accurate information about objects in at least one section of the monitored area can be obtained from the received pixels of the receiving area.

[0059] Advantageously, the received pixel signals of all received pixels within the reception area can be corrected. In this way, the spatial resolution with which objects can be detected within at least one section can be further improved.

[0060] Advantageously, the received pixel signals of multiple received pixels, especially all received pixels, can be corrected using the correction pixel signals of multiple correction pixels. This improves the accuracy of the correction.

[0061] In a further advantageous embodiment of the method, at least one of the received pixel signals can be corrected using the correction pixel signals of several correction pixels, in particular all correction pixels. In this way, statistical variations in crosstalk effects within the pixel field can also be better taken into account.

[0062] In a further advantageous embodiment of the method, a combination of correction pixel signals from several correction pixels, in particular at least an average of the correction pixel signals from several correction pixels, can be used to correct at least one of the received pixel signals. In this way, spatial variations of crosstalk effects in the pixel field can be better taken into account.

[0063] In a further advantageous embodiment of the method, the pixels, in particular the receiving pixels and / or correction pixels, can be formed by at least one photodiode, in particular at least one single-photon avalanche diode. In this way, receiving pixel signals can be generated with the pixels, which characterize the intensity of the light signals received by the pixels. Single-photon avalanche diodes (SPADs) can be used to count individual photons. The number of photons characterizes the intensity of the light signals received by the single-photon avalanche diode.

[0064] Advantageously, at least some of the pixels, and in particular all pixels, can be formed by a photodiode, especially a single-photon avalanche diode. In this way, a high spatial resolution can be achieved.

[0065] Advantageously, at least some of the pixels, and in particular all pixels, can be formed by multiple photodiodes, especially single-photon avalanche diodes. This allows for a higher resolution in determining the intensity of the light signals.

[0066] Alternatively, the pixel array can also be implemented using at least one CCD sensor, at least one active pixel sensor, or similar technology. This allows for a pixel array with a higher pixel density.

[0067] In a further advantageous embodiment of the method, the pixels, in particular the receiving pixels and / or correction pixels, of the pixel array can be activated and / or read out in coordination with a transmitting device for sending scanning light signals, in particular a transmitting device of a LiDAR system. In this way, a LiDAR system can be implemented. With the LiDAR system, the flight time of light signals between the transmission time of the scanning light signals on the transmitting device and the reception time of the light signals reflected from targets in the monitoring area on the receiving device can be determined. From the flight time, distances of targets from which the transmitted scanning light signals are reflected, relative to the receiving device and / or the transmitting device, in particular to the LiDAR system, can be determined.

[0068] Advantageously, the activation and / or reading of the pixels in the pixel array can be started and / or stopped with at least one trigger signal. In this way, a period during which the pixels in the pixel array can generate receive pixel signals or correction pixel signals can be precisely defined.

[0069] Advantageously, the transmission of scanning light signals can be started and / or stopped with at least one trigger signal. In this way, the period during which scanning light signals are transmitted can be precisely defined.

[0070] Advantageously, the transmission of scanning light signals and the activation / reading of pixels can be started and / or stopped with the same trigger signal. This allows the transmitting and receiving devices to be precisely synchronized.

[0071] Furthermore, the object of the invention is solved in the means by the fact that the means for carrying out the inventive method for correcting crosstalk effects is designed.

[0072] Advantageously, the means for assigning at least one section of a monitoring area to at least one receiving area of ​​a pixel field can be designed. In this way, a scene in the monitoring area can be assigned to the at least one receiving area of ​​the pixel field.

[0073] Advantageously, the means for assigning pixels to at least one receiving area of ​​a pixel array can be designed in such a way that it can be specified whether pixels of a pixel array lie within the at least one receiving area and are used as receiving pixels, or whether they lie outside the at least one receiving area and are used as correction pixels.

[0074] Advantageously, the means for carrying out the method according to the invention can be implemented at least partially in software. In this way, existing processors can be used to carry out the method.

[0075] Advantageously, the means for carrying out the method according to the invention can be implemented at least partially in hardware. In this way, means, in particular optical means, for assigning sections of the monitoring area to receiving areas of the pixel field can also be implemented.

[0076] Advantageously, the means for carrying out the method according to the invention can be implemented in or with a control and / or evaluation unit. In this way, hardware already contained in the control and / or evaluation unit, such as processors or the like, and software, such as algorithms or the like, can be used.

[0077] At least part of the means for carrying out the inventive method for correcting crosstalk effects can also be implemented outside the receiving device, outside the LiDAR system and outside the vehicle, for example in a cloud system.

[0078] Furthermore, the object of the invention is solved in the receiving device by the fact that the receiving device is designed to carry out at least part of the inventive method for correcting crosstalk effects.

[0079] According to the invention, at least part of the method for correcting crosstalk effects can be carried out within the receiving device. In this way, the received pixel signals can be corrected within the receiving device and made available for further processing.

[0080] Advantageously, the receiving device can comprise at least a part of the means according to the invention for carrying out the method according to the invention. In this way, the receiving device is enabled to carry out at least a part of the method according to the invention.

[0081] Furthermore, the problem is solved according to the invention in the LiDAR system by the fact that the LiDAR system is designed to carry out at least part of the inventive method for correcting crosstalk effects.

[0082] According to the invention, at least part of the method for correcting crosstalk effects can be carried out within the LiDAR system. In this way, the received pixel signals can be corrected within the LiDAR system and made available for further processing.

[0083] Advantageously, the LiDAR system can comprise at least a part of the means according to the invention for carrying out the method according to the invention. In this way, the LiDAR system is enabled to carry out at least a part of the method according to the invention.

[0084] The LiDAR system can be used to perform distance measurements by sending scanning light signals into at least one monitoring area of ​​the LiDAR system and receiving light signals reflected from targets in the monitoring area.

[0085] Advantageously, the LiDAR system can be a scanning LiDAR system. In this way, the monitored area can be scanned for objects.

[0086] Furthermore, the problem is solved according to the invention in the driver assistance system by the fact that the driver assistance system is designed to carry out at least part of the inventive method for correcting crosstalk effects.

[0087] Furthermore, the problem is solved according to the invention in the vehicle by the fact that the vehicle is designed to carry out at least part of the inventive method for correcting crosstalk effects.

[0088] According to the invention, at least part of the method for correcting crosstalk effects can be carried out within the vehicle. In this way, the received pixel signals can be corrected within the vehicle and made available for further processing.

[0089] The receiver can detect objects within a monitored area surrounding the vehicle. This further improves the vehicle's operational safety. Furthermore, information gathered by the receiver can be used for autonomous or semi-autonomous vehicle operation.

[0090] Advantageously, the vehicle can have at least one LiDAR system with at least one receiver. This allows distances and / or directions of targets detected by the LiDAR system to be determined relative to the vehicle. In this way, more information about the vehicle's surroundings can be obtained. This is of particular importance with regard to autonomous or semi-autonomous operation of the vehicle.

[0091] Advantageously, the vehicle can have at least one driver assistance system. In this way, the vehicle can be operated autonomously or semi-autonomously, in particular using the information provided by the optical receiving device, especially the LiDAR system, and in particular the corrected received pixel signals.

[0092] Furthermore, the features and advantages identified in connection with the inventive method, the inventive means, the inventive receiving device, the inventive LiDAR system, the inventive driver assistance system, and the inventive vehicle and their respective advantageous embodiments apply to each other accordingly, and vice versa. The individual features and advantages can, of course, be combined with one another, potentially resulting in further advantageous effects that go beyond the sum of the individual effects. Brief description of the drawings

[0093] Further advantages, features, and details of the invention will become apparent from the following description, in which exemplary embodiments of the invention are explained in more detail with reference to the drawing. The person skilled in the art will expediently consider the features disclosed in the drawing, the description, and the claims individually and combine them into meaningful further combinations. The drawing schematically illustrates Fig. 1 a vehicle equipped with a driver assistance system which includes a LiDAR system, in a situation in which there are three objects in front of the vehicle; Fig. 2. A functional diagram of the driver assistance system from the Fig. 1; Fig. 3. A top view of a pixel array of a receiving device of the LiDAR system from the Fig. 1; Fig. 4 a camera grayscale image of the situation from Fig. 1 in front of the vehicle Fig. 5 a grayscale image of the spatial distribution of received pixel signals across the pixel field Fig. 3 in the situation Fig. 1 in front of the vehicle; Fig. 6 a grayscale image of the spatial distribution of corrected received pixel signals across the pixel field Fig. 3 in the situation Fig. 1 in front of the vehicle; Fig. 7 the spatial intensity profile of received pixel signals within a column of a received area of ​​the pixel field from the Fig. 3 in the situation Fig. 1 in front of the vehicle; Fig. 8 temporal reception pixel signal profiles of the reception pixel signals of one of the reception pixels of the pixel field from the Fig. 3, which is assigned to one of the first of the three objects, in the situation from Fig. 1 in front of the vehicle, for comparison in the cases where one of the objects is retroreflective or non-retroreflective; Fig. 9 temporal reception pixel signal profiles of the reception pixel signals of one of the reception pixels of the pixel field from the Fig. 3, which is assigned to a second of the three objects, in the situation from Fig. 1 in front of the vehicle, for comparison in the cases where one of the objects is retroreflective or non-retroreflective; Fig. 10 temporal reception pixel signal profiles of the reception pixel signals of one of the reception pixels of the pixel field from the Fig. 3, which is assigned to a third of the three objects, in the situation from Fig. 1 in front of the vehicle, for comparison in the cases where one of the objects is retroreflective or non-retroreflective; Fig. 11 the pixel field, wherein detections of targets of the objects at a reception time T1 of a reception sequence of the situation from Fig. 1 are marked in black in front of the vehicle; Fig. 12 the pixel field, wherein detections of targets of the objects at a reception time T2 of a reception sequence of the situation from Fig. 1. are marked in black in front of the vehicle and ghost signals caused by crosstalk effects are indicated as black dots; Fig. 13 a flowchart for a procedure for correcting crosstalk effects between receiving pixels of the pixel field from Fig. 3.

[0094] In the figures, identical components are labelled with the same reference symbols. embodiment(s) of the invention

[0095] In Fig. Figure 1 shows a schematic side view of a vehicle 10. The vehicle 10 includes a driver assistance system 12. Fig. Figure 2 shows the driver assistance system 12 as a functional diagram. The driver assistance system 12 comprises a LiDAR system 14 and a control unit 16. The control unit 16 enables the autonomous or semi-autonomous control of vehicle functions 10, such as driving functions, based, among other things, on information acquired by the LiDAR system 14.

[0096] The LiDAR system 14 is shown, by way of example, arranged in a front area of ​​the vehicle 10. The LiDAR system 14 is directed into a monitoring area 18 in the direction of travel in front of the vehicle 10. The LiDAR system 14 can also be arranged in a different location, in particular with a different orientation. Multiple LiDAR systems 14 can also be provided.

[0097] The LiDAR system 14 can be used to monitor the surveillance area for objects 20. In the Fig. Figure 2 shows an example of object 20. In the Fig. Figure 1 shows a situation in which, by way of example, three objects 201, 202, and 203 are located in monitoring area 18. For better differentiation, the reference symbols 20 of the objects are labeled with the indices 1, 2, and 3.

[0098] With the LiDAR system 14, distances 22 and directions 24 of targets 26 of objects 20 can be determined relative to the LiDAR system 14.

[0099] Targets 26 are locations on objects 20 where scan light signals 28 emitted by the LiDAR system 14 can be reflected. An object 20 typically comprises a multitude of targets 26 where scan light signals 28 can be reflected.

[0100] The reflected scanning light signals 28, which are reflected back towards the LiDAR system 14, can be received as echo light signals 30 by the LiDAR system 14.

[0101] Information about detected objects 20, such as distances 22, directions 24, and echo signal intensities 30, obtained by the LiDAR system 14, can be transmitted to the control unit 16. The control unit 16 can use the information obtained by the LiDAR system 14 to control the autonomous or semi-autonomous operation of the vehicle 10.

[0102] The LiDAR system 14 is designed as an exemplary scanning LiDAR system. With the LiDAR system 14, the monitoring area 18 can be scanned by LiDAR measurements. In the illustrated embodiment, the monitoring area 18 can be scanned in a horizontal direction.

[0103] In the Fig. Figures 1 to 6, 11, and 12 indicate the respective coordinate axes of an orthogonal xyz coordinate system for easier orientation. The y-axis runs parallel to a transverse axis 32 of vehicle 10. The x-axis runs parallel to a longitudinal axis 34 of vehicle 10. The z-axis runs parallel to a vertical axis 36 of vehicle 10. When the description refers to "horizontal," this refers to a path parallel to the xy-plane, i.e., perpendicular to the vehicle's vertical axis 36. "Vertical" refers to a path parallel to the z-axis, i.e., to the vehicle's vertical axis 36.

[0104] The LiDAR system 14 comprises a transmitting unit 38, a receiving unit 40 and a control and evaluation unit 42.

[0105] The transmitting device 38 comprises one or more light sources, for example laser diodes. The scanning light signals 28 can be generated using the light sources.

[0106] Furthermore, the transmitting device comprises 38 optical components, such as lenses, objectives, or mirrors, with which the scanning light signals 28 are directed into the monitoring area 18. Optical components may be provided with which the scanning light signals 28 can be shaped, for example, focused or extended perpendicular to their direction of propagation.

[0107] For example, the LiDAR system 14 can be designed as a so-called flash LiDAR system. In a flash LiDAR system 14, the scanning light signals 28 are sent simultaneously throughout the entire monitoring area 18, similar to a flash of light.

[0108] Alternatively, instead of being configured as a flash LiDAR system, the LiDAR system 14 can have a scanning transmitting device 38. The propagation direction of the scanning light signals 28 can then be swiveled, for example, by means of a rotating mirror within the monitoring area 18. In this way, the monitoring area 18 can be scanned with the scanning light signals 28.

[0109] The receiving device 40 comprises a light signal deflection device 44 and a receiving sensor 46.

[0110] The light signal deflection device 44 can, for example, be a rotating mirror. The rotating mirror can be rotatable about an axis that runs vertically, i.e., parallel to the z-axis. Furthermore, the receiving device 40 can have optical components, such as optical lenses.

[0111] The receiving sensor 46 is designed as an area sensor by way of example. The receiving sensor 46 has a pixel field 48. In the Fig. Figure 3 shows pixel field 48 viewed opposite to the x-axis. Pixel field 48 comprises a multitude of pixels 50, namely receiving pixels 50. E and correction pixels 50 K The 50 pixels are arranged in rows parallel to the y-axis and columns parallel to the z-axis. As will be explained in more detail below, the 50 pixels are designated as receiving pixels. E and correction pixels 50 K used. For easier differentiation, the reference numbers 50 for the pixels are therefore each marked with the index "E" or "K".

[0112] The reception pixels are 50 E and the correction pixels 50 K are identical in form and function. Each receiving pixel contains 50 pixels. E and each correction pixel 50 Kis formed by several photodiodes 52. The photodiodes 52 are, for example, single-photon avalanche diodes (SPADs). With the photodiodes 52, individual photons can be received and counted. In the Fig. Figure 3 shows some of the photodiodes 52 of a correction pixel 50 as examples. K As indicated, the photodiodes 52 of the same pixel 50 can be controlled and read out together. The signals generated by the photodiodes 52 of the same pixel 50, which will be explained in more detail below, can be combined and used as a single signal for pixel 50. In this way, the total number of photons striking the respective pixel 50 can be counted, and the intensity of the incident light rays can be determined from this.

[0113] In another embodiment not shown, each of the pixels 50 can also comprise only one photodiode 52.

[0114] Depending on the setting of the light signal deflection device 44, for example, the rotational position of the mirror, a corresponding section 54 of the monitoring area 18 is mapped onto the pixel field 48. By changing the setting of the light signal deflection device 44, for example, by rotating the mirror, the field of view of the receiving device 40 is pivoted in a horizontal direction, namely parallel to the xy-plane, so that a different section 54 in the monitoring area 18 is detected. In this way, the monitoring area 18 is scanned in a horizontal scan direction 58, namely parallel to the xy-plane. Fig. 2 Some sections of 54 are indicated between dashed lines.

[0115] In every setting of the light signal deflection device 44, the corresponding sections 54 are always mapped onto the same receiving area 56 of the pixel array 48. The receiving area 56 extends over the entire vertical height of the pixel array 48 in the direction of the z-axis. In the horizontal direction, i.e., in the direction of the y-axis, the receiving area 56 extends, for example, over two columns of the pixel array 48.

[0116] The 50 pixels located within the reception area of ​​56 are designated as reception pixels 50. E The pixels 50 are used to receive echo light signals 30. The pixels 50 located outside the reception area 56 cannot be reached by echo light signals 30. These pixels 50 are designated as correction pixels 50. K used.

[0117] The following describes a procedure for performing LiDAR measurements with the LiDAR system 14, using a measurement sequence as an example. During the measurement sequence, one of the sections 54 of the monitoring area 18 is recorded with the LiDAR system 14.

[0118] To start the measurement sequence, the control and evaluation unit 42 sends a trigger signal to the transmitter 38 and the receiver 40. The trigger signal activates the transmitter 38 to send a scanning light signal 28. Simultaneously, the trigger signal activates the receiver 40 to start a reception sequence 60.

[0119] In the Fig. 8, Fig. 9 to Fig. Figure 10 shows an example of a receive sequence 60 in the time dimension. The receive sequence 60 has a predetermined time length. This time length can be specified, for example, by the maximum flight time of the scanning light signals 28 and the reflected echo light signals 30, which corresponds to the maximum intended range of the LiDAR system.

[0120] In the receive sequence 60, the receive pixels are 50 E and the correction pixels 50 K Pixel field 48 was activated and read.

[0121] For the sake of easier differentiation, the following will refer to signals which are received by 50 pixels. E These signals are generated and referred to as receive pixel signals 62. Signals generated by correction pixels 50 K The generated signals are referred to as correction pixel signals 64.

[0122] As long as the photodiodes 52 of the receiving pixels 50 ENot being hit by echo light signals 30, the receiving pixels generate 50 E 62 received pixel signals, which are in the Fig. 2 are indicated, which are solely determined by noise. Furthermore, as long as no echo light signals 30 are directed at the receiving pixels 50. E These pixels do not emit any crosstalk effects. Therefore, the correction pixels (50) are also... K The generated correction pixel signals 64 are determined solely by noise.

[0123] Noise as defined in the invention is not caused by crosstalk effects. Ideally, the noise is homogeneous across the pixel field 48. This noise can also be referred to as background noise.

[0124] In the Fig. 8, Fig. 9 to Fig. 10 are the temporal reception pixel signal profiles 63 rThe received pixel signals 62 for the case where the LiDAR system 14 hits a highly reflective object 20 are shown as dashed lines. The case where the LiDAR system 14 hits a normally reflective object 20 is shown by the temporal received pixel signal profiles 63. n represented by solid lines.

[0125] In the described embodiment, the received pixel signals 62 and the correction pixel signals 64 are transmitted to the control and evaluation unit 42 for processing. In an embodiment not shown, at least part of the means for processing the received pixel signals 62 and correction pixel signals 64 can be contained in the receiving unit 40. In this case, transmission of the received pixel signals 62 and the correction pixel signals 64 to the control and evaluation unit 42 is not necessary.

[0126] The receive pixel signals 62 are used to detect objects 20 located in section 54 of the monitoring area 18. The correction pixel signals 64 are used to correct crosstalk effects on the receive pixels 50. E used.

[0127] If an object 20 is located in section 54 of the monitoring area 18, which is detected by the LiDAR system 14, the scanning light signals 28 are reflected at the targets 26 of the object 20. Echo light signals 30 reflected towards the LiDAR system 14 are directed by the light signal deflection device 44 into the receiving area 56 of the pixel field 48 on the corresponding receiving pixel 50. E guided.

[0128] As soon as the received signals reach 62 of the hit received pixels, 50 E above one in the Fig. 8, Fig. 9 to Fig. If the noise threshold 66 shown in the diagram is not exceeded, these signals are recognized as detections of the corresponding target 26 from which the echo light signal 30 originates. The distance 22 to the target 26 from which the corresponding echo light signal 30 originates is determined from the flight time of the scanning light signal 28 from the time of transmission, which is determined by the trigger signal, until the reception of the echo light signal 30, which is recognized as a detection, at a reception time T.

[0129] In the Fig. 8, Fig. 9 to Fig. Figure 10 shows the reception times T1, T2, and T3 for three targets 26 at different distances. The reference symbol T is marked with the indices 1, 2, or 3 for clarity.

[0130] The noise threshold 66 is specified, for example, based on test measurements taken before the initial commissioning of the LiDAR system 14. The noise threshold 66 is chosen to be above the noise that occurs during normal operation of the LiDAR system 14 without illumination of the receiver 40.

[0131] If a highly reflective, for example retroreflective, object 20 is located in section 54 of the monitoring area 18, which is captured in the measurement sequence with the receiving pixels 50 within the receiving area 56, the scanning light signals 28 are reflected as echo signals 30 with slight intensity losses. Due to the high intensity of the light signals reaching the receiving pixels 50 E Hitting echo light signals 30 can lead to oversaturation of the hit receiving pixels 50 E and crosstalk effects, such as blooming, occur. The crosstalk effects affect neighboring receiving pixels 50 Eand adjacent correction pixels 50 K .

[0132] Crosstalk effects can cause detected objects 20 to appear larger in the reception area 56 than they actually are. Furthermore, in reception pixels 50 E Objects not reached by echo light signals 30 may be falsely detected due to the intensity increases caused by crosstalk effects, resulting in the identification of targets that are not real and can therefore be described as "ghost targets". Overall, crosstalk effects can lead to inaccuracies in distance measurements and the obscuring of actual objects 20. For this purpose, the procedure for correcting crosstalk effects described below is performed.

[0133] The following describes a measurement sequence based on an exemplary situation in front of vehicle 10, which is in Fig. Figure 4, shown as a camera grayscale image, is explained in more detail.

[0134] The situation corresponds to that in Fig. The situation shown in section 1 with the vehicle is as follows. In order to cover the entire monitoring area 18, several measurement sequences are carried out, between which the monitored section 54 is swiveled.

[0135] During the measurement sequence, the three objects 201, 202, and 203 are located in section 54 of the monitoring area 18, which is being recorded by the LiDAR system 14. For easier orientation, section 54 is highlighted in the grayscale image during this measurement sequence. Fig. 4 is indicated by a dashed rectangle.

[0136] Object 201 is at the closest distance 22, object 203 is at the greatest distance, and object 202 is at a distance 22 between object 201 and object 203. From the perspective of LiDAR system 14, the nearest object 201 is on the ground, object 202 is above object 201, and object 203 is above object 202.

[0137] The surfaces of objects 201 and 203 exhibit comparatively low absorption for the scanning light signals 28. For example, the surfaces of objects 201 and 203 are matte black.

[0138] Object 202 has a retroreflective surface with comparatively low absorption for the scanning light signals 28. For example, object 202 is a road sign with a partially white, retroreflective surface.

[0139] The scanning light signals 28 reflected from the retroreflective object 202 are interpreted as strong echo light signals 30 with the corresponding values ​​in the received pixels 50. E received. The high intensity of the echo light signals 30 leads to an oversaturation of the received pixels 50. E and to crosstalk effects on the other receiving pixels 50 E and the correction pixels 50 K .

[0140] In the Fig. Figure 5 is a grayscale image of the spatial distribution of the received pixel signals 62 across the pixel field 48 for the in Fig. Figure 4 shows the situation after completion of several measurement sequences in which the monitoring area 18 was completely scanned. For easier orientation, section 54 is indicated by a dashed rectangle during the measurement sequence described above.

[0141] The strong echo light signals 30 in the corresponding received pixels 50E 50 resulting crosstalk effects in the neighboring receiving pixels E This results in the following within section 54 above and below the receiving pixel 50 E , which are struck by echo light signals 30 of the retroreflective object 202, receive pixel signals 62 are generated that are significantly larger than the receive pixel signals 62 that are actually directed at these receive pixels 50 E accurate echo light signals 30, which originate from the two other objects 201 and 203. In total, nearly oversaturated received pixels 50 E , which are hit by the echo light signals 30 of the retroreflective object 202, and the crosstalk effects on the neighboring receiving pixels 50 E to the fact that the outlines of detections do not match any of the three objects 201, 202 and 203, as shown in the grayscale image from Fig. As can be seen in section 5, they are clearly defined. Precise distance information 22 cannot be given for any of the three objects 201, 202, and 203. The procedure for correcting crosstalk effects described below must be carried out beforehand.

[0142] In Fig. 6 is a grayscale image corresponding to the grayscale image from the Fig. Figure 5 shows the spatial distribution of received pixel signals 62 after correction of crosstalk effects, i.e., the spatial distribution of corrected received pixel signals 86. After correction of crosstalk effects, the detections of objects 201, 202, and 203 can be distinguished from one another in section 54.

[0143] In the Fig. 7 is the spatial intensity profile 68 rof the received pixel signals 62, upper curve, according to the measurement sequence described above for the corresponding section 54 within a column of the received area 56 in the area of ​​the received pixels 50 E The curves shown below show the objects struck by the echo light signals 30 from the retroreflective object 202 and the two other objects 201 and 203, from bottom to top. The lower curve shows the spatial intensity profile 68 for comparison. n after a measurement sequence in the same section 54 for the case that the surface of object 202 is not retroreflective, but merely exhibits lower absorption for the scanning light signals 28 compared to the surfaces of the other two objects 201 and 203. For example, the surface of object 202 can be matte white in this case.

[0144] The zero line for intensity is in the Fig. The noise threshold of 66 is set. The unshown intensity component below the zero line is due to the noise.

[0145] The areas of intensity profiles 68 r and 68 n The areas in the middle correspond to the received pixel signals 62, which are caused by the echo light signals 30 from the central object 202. The areas of the intensity profiles 68 r and 68 n The left side corresponds to the received pixel signals 62, which are caused by the echo light signals 30 from the lower object 201. The areas of the intensity profiles 68 r and 68 n The right side corresponds to the received pixel signals 62, which are caused by the echo light signals 30 from the upper object 203.

[0146] In the intensity curve 68 r , Fig. The 50 receiving pixels are located at the top, number 7. Ein the central area, which is assigned to the retroreflective object 202, near supersaturation. In addition, crosstalk effects cause the received pixel signals 62 in the left and right areas, which are assigned to the other two objects 201 and 202, to be weaker compared to the intensity profile 68. n for the non-retroreflective object 202, Fig. 7 below, are significantly increased. A background offset of 92 r Above the noise threshold 66 for the received pixel signals 62, in the case of a retroreflective object 202, is significantly larger than a background offset 92. n for the received pixel signals 62 in the case of a non-retroreflective object 202.

[0147] In the Fig. Figure 8 shows the temporal reception pixel signal profiles for comparison. r and 63 n of the received pixel signals 62 one of the received pixels 50 Eshown, which is struck by echo light signals 30 during the measurement sequence described above, which were reflected by the lower object 201. The received pixel signal profile 63 is shown with a dashed line. r This corresponds to the situation in which the middle object 202 has a retroreflective surface. The received pixel signal profile 63, drawn with a solid line for comparison, is shown. n This corresponds to the situation in which the middle object 202 has a non-retroreflective surface.

[0148] At the reception time T1, both the received pixel signal profile 63 r , as well as 63 n a peak 941. Peak 941 corresponds to the received pixel signal 62, which is generated by the echo light signal 30 reflected from a target 26 of the lower object 201 and corresponds to the hit received pixel 50. Eis generated. The reception time T1 indicates the flight time of the scanning light signal 28 and the echo light signal 30 reflected at this target 26 of the lower object 201. From the flight time, the distance 22 of the corresponding target 26 of the lower object 201 can be determined.

[0149] The received pixel signal profile 63 r For the situation with the retroreflective object 202, there is an additional peak at time T2, which will be referred to below as ghost peak 96 for better differentiation. Ghost peak 96 corresponds to the received pixel signal 62, which is present in the considered received pixel 50. E This is caused by crosstalk effects. These crosstalk effects are generated by the receiving pixel 50. EThe echo light signal 30, reflected from a target 26 of the middle retroreflective object 202, is encountered at time T2. The reception time T2 indicates the flight time of the scanning light signal 28 and the echo light signal 30 reflected from the target 26 of the middle retroreflective object 202. However, this flight time does not correspond to the distance 22 of the lower object 201, but rather to the distance 22 of the middle retroreflective object 202. Overall, the determination of the distance 22 is disrupted by the crosstalk effects caused by the retroreflective object 202.

[0150] The received pixel signal profile 63 n However, the situation with the normally reflecting object 202 does not exhibit ghost peak 96. Therefore, the distance 22 for the lower object 221 can be determined using the time-of-flight measurement.

[0151] In the Fig. 9 are analogous to Fig. 8 For comparison, the temporal reception pixel signal profiles 63 r and 63 n of the received pixel signals 62 one of the received pixels 50 E shown, which is struck by echo light signals 30 during the measurement sequence described above, which, unlike Fig. 8 were reflected from the middle object 202.

[0152] At time T2, the received pixel signal curve shows 63 n For the situation with the normally reflecting central object 202, a peak 942 appears. Peak 942 corresponds to the received pixel signal 62, which is generated by the echo light signal 30 reflected from a target 26 of the central object 202 and intersects the received pixel 50. E is generated. In the received pixel signal profile 63 rFor the situation with the retroreflective middle object 202, peak 942 is superimposed with the ghost peak 96. The reception time T2 can be used to determine the distance 22 of the corresponding target 26 of the middle object 20 for both the situation with the normally reflecting middle object 202 and the situation with the retroreflective object 202.

[0153] In the Fig. 9 are analogous to Fig. 8 For comparison, the temporal reception pixel signal profiles 63 r and 63 n of the received pixel signals 62 one of the received pixels 50 E shown, which is struck by echo light signals 30 during the measurement sequence described above, which, unlike Fig. 8 were reflected from the upper object 203.

[0154] At a reception time T3, both the received pixel signal profile 63 r , as well as 63 na peak 943. Peak 943 corresponds to the received pixel signal 62, which is generated by the echo light signal 30 reflected from a target 26 of the upper object 203 and corresponds to the hit received pixel 50. E is generated. The reception time T3 indicates the flight time of the scanning light signal 28 and the echo light signal 30 reflected at this target 26 of the upper object 203. From the flight time, the distance 22 of the corresponding target 26 of the upper object 203 can be determined.

[0155] As in Fig. 8 shows the received pixel signal profile 63 r For the situation with the retroreflective object 202 at reception time T2, an additional ghost peak 96 is generated by the described crosstalk effects, which distorts, if not completely prevents, the determination of the correct flight time and thus the determination of the correct distance 22 of the target 26 of the upper object 203.

[0156] Fig. Figure 11 shows pixel field 48 at reception time T1 of the reception sequence 60 according to the Fig. 8, Fig. 9 to Fig. 10. In the Fig. 11 detections 981 from targets 26 of the lower object 201 are marked as black areas. The detections 981 are at the receive pixels 50. E Detected which are hit by echo light signals 30 coming from targets 26 of the lower object 201.

[0157] Fig. Figure 12 shows pixel field 48 at reception time T2 of the reception sequence 60 according to the Fig. 8, Fig. 9 to Fig. 10. In the Fig. Detections 982 of targets 26 of the central, retroreflective object 202 are marked as black areas. Detections 982 are recorded at receive pixels 50. E Detected which are hit by echo light signals 30, which come from targets 26 of the central, retroreflective object 202. In addition, ghost signals 100 are in receive pixels 50.E and correction pixels 50 K marked as black dots. For clarity, only a few of the ghost signals (100) are labeled with reference symbols. The ghost signals (100) are caused by crosstalk effects from the receiving pixels (50). E come, which are hit by echo light signal 30 from targets 26 of the retroreflective object 202. In the receiving pixels 50 E The ghost signals lead to 100 ghost detections.

[0158] The following describes the procedure for correcting crosstalk effects between receiving pixels 50 E based on a Fig. The process is explained in more detail in the flowchart shown in Figure 13. The procedure for correcting crosstalk effects is carried out in real time immediately after the generation of the receive pixel signals 62 and the correction pixel signals 64.

[0159] In a capture step 70, the receive pixel signals 62 of the receive pixels 50 and the correction pixel signals 64 of the correction pixels 50 are recorded. K captured in reception sequence 60.

[0160] In test step 72, a test instrument 74 of the control and evaluation unit 42 is used to check whether there are indications of crosstalk effects.

[0161] The test for crosstalk effects will be performed using one or more of the three methods described below. The three methods for testing for crosstalk effects can be used alternatively or in combination. If several of the three methods are combined, they can be performed simultaneously or sequentially.

[0162] In the first method for checking for crosstalk effects, 50 correction pixels are used. K, which are adjacent to the reception area 56 of the pixel field 48, were checked to see if their correction pixel signals 64 are below the noise threshold 66.

[0163] Are all correction pixel signals located at 64 of the correction pixels under consideration? K Below the noise threshold of 66, the correction pixel signals 64 provide no indication of crosstalk effects.

[0164] Is at least one of the correction pixel signals 64 or at least one of the correction pixels 50 present? K Above the noise threshold 66, this indicates that the responding correction pixel signal 64 was caused by crosstalk effects from one of the receiving pixels 50.

[0165] In the second method for checking for crosstalk effects, 50 are used for the receiving pixels. E checked whether their received pixel signals were 62 below one in the Fig. The indicated threshold value of 98 is 7.

[0166] The threshold value 98 is individually specified for the receiving device 40. For example, the threshold value 98 can be specified based on test measurements that test at what signal value of the received pixel signals 62 crosstalk effects are triggered in other pixels of the Excel field 48.

[0167] Are all received pixel signals located at 62 of the received pixels? E Below the threshold value of 98, the received pixel signals 62 provide no indication of crosstalk effects.

[0168] Is at least one of the received pixel signals 62 or at least one of the received pixels 50? E Above the threshold value of 98, this indicates that at least one received pixel of 50 is present. E Crosstalk effects are expected.

[0169] The third method for checking for crosstalk effects verifies whether at least one of the receiving pixels has 50 E is oversaturated.

[0170] If none of the reception pixels are 50 E If the sample is oversaturated, no indication of crosstalk effects can be derived from this.

[0171] Is at least one of the receiving pixels 50 E If the signal is oversaturated, this indicates that at least one of the received pixels is oversaturated (50). E Crosstalk effects are expected.

[0172] If the examination in test step 72, using one or more of the three methods, reveals no evidence of crosstalk effects, the crosstalk correction procedure is terminated with a termination step 76. The procedure can be restarted for the following reception sequences 60.

[0173] If the examination in test step 72, using one or more of the methods, reveals that there are indications of crosstalk effects, the procedure for correcting crosstalk effects is carried out with a combination step 78.

[0174] In the combination step 78, the correction pixel signals 64, which lie above the noise threshold 66, are combined to form a correction signal 79. For example, an average value is calculated from the values ​​of the correction pixel signals 64, which is then used as the value for the correction signal 79. The combination of the correction pixel signals 64 is performed using a combination average 80 of the control and evaluation unit 42.

[0175] Subsequently, in a correction step 82, the received pixel signals 62 of the received pixels 50 are E The correction signal 79 is used to correct the received pixel signals 86. The correction is performed using a correction agent 84 of the control and evaluation unit 42. For example, the value of the correction signal 78 is subtracted from the values ​​of the received pixel signals 62. The reduced values ​​are then used as the values ​​of the corrected received pixel signals 86.

[0176] Subsequently, in a provisioning step 88, the corrected received pixel signals 86 are transferred to an evaluation device 90 of the control and evaluation unit 42.

[0177] Finally, the procedure for correcting crosstalk effects is terminated with termination step 76.

[0178] After completion of the crosstalk correction process, the corrected received pixel signals 86 are used with the evaluation tool 90 to determine detection data for targets 26. For a received pixel 50 E The detection of a target 26 is identified if its corrected received pixel signal 86 is above the noise threshold 66.

[0179] The detection data includes the coordinates of the corresponding receiving pixels 50 E, the corrected correction pixel signals 86 and the respective reception times T. From the detection data, distances and directions of targets 26 belonging to the detections relative to the LiDAR system 14 can be determined. QUOTES INCLUDED IN THE DESCRIPTION

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

[0000] US 20230003859 A1

[0007]

Claims

[1] Methods for correcting crosstalk effects between pixels (50 E , 50 K ) a pixel field (48) of an optical receiving device (40), in particular an optical receiving device (40) of a LiDAR system (14), in particular an optical receiving device (40) of a LiDAR system (14) of a vehicle (10), which, when detecting light signals (30) from a monitoring area (18) of the optical receiving device (40) with receiving pixels (50) for detecting light signals (30) E ) used pixels of the pixel field (48) can occur, whereby in the procedure at least one correction pixel signal (64) is captured, which is connected to at least one correction pixel (50) K ) during at least one reception sequence (60) is generated with the receiving device (40), wherein correction pixels (50 K ) pixels of the pixel field (48) that are not used for the detection of light signals (30), at least one received pixel signal (62) is captured, which corresponds to at least one of the received pixels (50) E ) is generated, at least one of the received pixel signals (62) at least one of the received pixels (50) E ) using at least one of the correction pixel signals (64) at least one of the correction pixels (50) K ) is corrected, characterized by , that at least one section (54) of the monitoring area (18) is mapped onto the pixel field (48) and at least one area of ​​the pixel field (48) onto which the at least one section (54) of the monitoring area (18) is mapped, is used as at least one receiving area (56) within the pixel field (48) for receiving light signals (30). and the pixels of the pixel field (48) within the at least one reception area (56) as reception pixels (50) E) are used and the pixels of the pixel field (48) outside the at least one reception area (56) are used as correction pixels (50) K ) be used. [2] Method according to claim 1, characterized by , that first it is checked whether there are indications of crosstalk effects, if this is the case, at least one of the received pixel signals (62) at least one of the received pixels (50) E ) is corrected using at least one of the correction pixel signals (64), otherwise no correction of the at least one receive pixel signal (62) of the at least one receive pixel (50) E ) is carried out. [3] Method according to claim 1 or 2, characterized by , that it is first checked whether at least one of the correction pixel signals (64) at least one of the correction pixels (50) K ) exceeds a predetermined noise threshold (66), in particular the correction pixel signals (64) of several correction pixels (50) K) each exceed a specified noise threshold (66), and / or whether at least one received pixel signal (62) of at least one received pixel (50) E ) exceeds a specified threshold value (98) and / or at least one of the received pixels (50) E ) is oversaturated if at least one of the correction pixel signals (64), in particular the correction pixel signals (64) of several correction pixels (50) K ), exceeds the respective noise threshold (66), and / or if at least one of the received pixel signals (62) exceeds the specified limit threshold (98) and / or if at least one of the received pixels (50 E ) is oversaturated, at least one of the received pixel signals (62) at least one of the received pixels (50) E ) is corrected using at least one of the correction pixel signals (64), otherwise no correction of the at least one receive pixel signal (62) of the at least one receive pixel (50)E ) is carried out. [4] Method according to claim 3, characterized by , that it is checked whether at least one of the correction pixel signals (64) at least one of the correction pixels (50) K ), in particular several correction pixels (50 K ), in the immediate vicinity of which at least one reception area (56) exceeds the specified noise threshold (66). [5] Method according to any of the preceding claims, characterized by , that the at least one received pixel signal (62) is reduced for correction by a value based on at least one of the correction pixel signals (64), in particular an average of several correction pixel signals (64). [6] Method according to any of the preceding claims, characterized by, that the procedure for correcting crosstalk effects is carried out before detections of targets (26) of objects (20) from which the detected light signals (30) originate are determined on the basis of the received pixel signals (62), in particular on the basis of the corrected received pixel signals (86). [7] Method according to any of the preceding claims, characterized by , that the procedure for correcting crosstalk effects is carried out in real time, in particular immediately after the generation of receive pixel signals (62) and correction pixel signals (64). [8] Method according to any of the preceding claims, characterized by , that the received pixels (50 E ) and the correction pixels (50 K ) generated raw data can be used as received pixel signals (62) or as correction pixel signals (64). [9] Method according to any of the preceding claims, characterized by , that the received pixel signals (62) of several received pixels (50 E), in particular all receiving pixels (50 E ), of the receiving area (56) using the correction pixel signals (64) at least one of the correction pixels (50 K ), in particular several correction pixels (50 K ), will be corrected. [10] Method according to any of the preceding claims, characterized by , that at least one of the received pixel signals (62) at least one of the received pixels (50 E ) using the correction pixel signals (64) of several correction pixels (50 K ), in particular all correction pixels (50 K ), will be corrected. [11] Method according to any of the preceding claims, characterized by , that to correct at least one of the received pixel signals (62) at least one of the received pixels (50) E ) a combination of the correction pixel signals (64) of several correction pixels (50) K ), in particular at least one mean value of the correction pixel signals (64) of several correction pixels (50 K). [12] Method according to any of the preceding claims, characterized by , that the pixels (50 E , 50 K ), in particular the receiving pixels (50 E ) and / or correction pixels (50 K ), formed by at least one photodiode (52), in particular at least one single-photon avalanche diode. [13] Method according to any of the preceding claims, characterized by , that the pixels (50 E , 50 K ), in particular the receiving pixels (50 E ) and / or correction pixels (50 K ), of the pixel field (48) in coordination with a transmitting device (38) for transmitting scanning light signals (28), in particular a transmitting device (38) of a LiDAR system (14), is activated and / or read out. [14] Means (42) which is designed to carry out a method for correcting crosstalk effects between pixels (50 E , 50 K) a pixel field (48) of an optical receiving device (40), in particular an optical receiving device (40) of a LiDAR system (14), in particular an optical receiving device (40) of a LiDAR system (14) of a vehicle (10), which, when detecting light signals (30), has receiving pixels (50) for detecting light signals (30). E ) used pixels of the pixel field (48) may occur, characterized by , that the means (42) for carrying out the method for correcting crosstalk effects is designed according to one of claims 1 to 13. [15] Optical receiving device (40), in particular optical receiving device (40) of a LiDAR system (14), in particular optical receiving device (40) of a LiDAR system (14) of a vehicle (10), with at least one pixel field (48) which has at least two pixels (50) E ) exhibits which are suitable for use as receive pixels (50 E) are designed to detect light signals (30), and which has at least one pixel (50 K ) has which is for use as a correction pixel (50 K ), with which no light signals (30) are detected, and is designed with at least part of a means for carrying out a method for correcting crosstalk effects between receiving pixels (50 E ) of the pixel field (48), which in the case of a detection of light signals (30) with the receiving pixels (50 E ) may occur, characterized by , that the receiving device (40) is designed to carry out at least part of the method for correcting crosstalk effects according to one of claims 1 to 13. [16] LiDAR system (14), in particular LiDAR system (14) for a vehicle (10), comprising at least one optical transmitter (38) for transmitting scanning light signals (28) into at least one monitoring area (18), comprising at least one optical receiver (40) for receiving echo light signals (30) coming from the at least one monitoring area (18) which originate from scanning light signals (28) reflected in the monitoring area (18), comprising at least one control unit (42) for controlling the functions of the LiDAR system (14) and comprising at least part of a means for carrying out a method for correcting crosstalk effects between receiving pixels (50) E ) the at least one optical receiving device (40) which, in the case of detection of light signals (30), is connected to the receiving pixels (50) E) can occur, wherein the at least one optical receiving device (40) comprises at least one pixel field (48) which includes at least two pixels (50) E ) exhibits which are suitable for use as receiving pixels (50 E ) are designed to detect echo light signals (30), and at least one pixel (50 K ) has which is for use as a correction pixel (50 K ), with which no echo light signals (30) are detected, is designed, characterized by , that the LiDAR system (14) is designed to carry out at least part of the method for correcting crosstalk effects according to any one of claims 1 to 13. [17] Driver assistance system (12) with at least one optical receiving device (40), in particular at least one optical receiving device (40) according to claim 15, in particular at least one optical receiving device (40) of at least one LiDAR system (14), in particular at least one LiDAR system (14) according to claim 16, with at least one control unit (16) and with at least one part of a means for carrying out a method for correcting crosstalk effects between receiving pixels (50) E ) the at least one optical receiving device (40) which, in the case of detection of light signals (30), is connected to the receiving pixels (50) E ) may occur, characterized by , that the driver assistance system (12) is designed to carry out at least part of the method for correcting crosstalk effects according to claims 1 to 13. [18] Vehicle (10) with at least one optical receiving device (40), in particular at least one optical receiving device (40) according to claim 15, in particular at least one optical receiving device (40) of at least one LiDAR system (14), in particular at least one LiDAR system (14) according to claim 16, and at least one part of a means for carrying out a method for correcting crosstalk effects between receiving pixels (50) E ) the at least one optical receiving device (40) which, in the case of detection of light signals (30), is connected to the receiving pixels (50) E ) may occur, characterized by , that the vehicle (10) is designed to carry out at least part of the method for correcting crosstalk effects according to claims 1 to 13.

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