Method for operating a lidar system, lidar system, driver assistance system, and vehicle

Abstract

The invention relates to a method for operating a lidar system of an autonomous or at least partially autonomous vehicle, in which at least one optical scanning beam is generated using at least one transmitting device of the lidar system and is transmitted into a monitoring region of the lidar system. At least one individual image is generated which characterizes the scene in the monitored area in at least one spatial dimension with reference to at least one monitored variable. In order to generate individual images, output quantities of at least two electro-optical receiving elements (36) of a receiving field (34) of a receiving device of the lidar system are detected, said receiving field having a plurality of receiving elements (36). According to the invention, at least one receiving group (64) is formed, to which at least two receiving elements (36) are associated, the at least one receiving group (64) being defined by a predefinable imaginary group frame (66) which surrounds a defined layout of the receiving elements (36) of the receiving field (34) and can be displaced along the receiving field (34). At least a portion of the output quantities of at least a portion of the receiving elements (36) belonging to the same receiving group (64) are merged into a corresponding group output quantity. At least two individual images are generated, between which the group frame (66) is displaced with a predetermined displacement vector along the receiving field (34) for at least one receiving group (64). Because the magnitude of the displacement vector is smaller than the vertical extension of the group frame (66) in the direction of the displacement vector and thus smaller than the vertical extension of the receiving groups (64) in the direction of the displacement vector, the receiving groups (64) of the individual images following one another are superimposed in each case in a row of receiving elements (36). Resolution is improved by superposition of individual images.

Description

TECHNICAL FIELD

[0001] The invention relates to a method for operating a laser radar system, in particular a laser radar system of a vehicle, wherein at least one optical scanning beam is generated by at least one emitting device of the laser radar system, the at least one scanning beam is transmitted into a monitoring region of the laser radar system, at least one individual image is generated which characterizes a scene in the monitoring region in at least one spatial dimension with reference to at least one monitoring quantity, wherein, for generating the at least one individual image, output quantities of at least two electro-optical receiving elements of a receiving field of a receiving device of the laser radar system are detected, the receiving field having a plurality of receiving elements.

[0002] Furthermore, the invention relates to a laser radar system, in particular for a vehicle, having at least one emitting device for transmitting an optical scanning beam into a monitoring region, at least one receiving device for receiving an optical beam and outputting a corresponding output quantity, and at least one control and evaluation device for controlling the at least one emitting device and the at least one receiving device and processing the output quantities output by the at least one receiving device.

[0003] Furthermore, the invention relates to a driver assistance system having at least one laser radar system, in particular at least one laser radar system for a vehicle, wherein the at least one laser radar system has at least one emitting device for transmitting an optical scanning beam, at least one receiving device for receiving an optical beam and outputting a corresponding output quantity, and at least one control and evaluation device.

[0004] Furthermore, the invention relates to a vehicle having at least one laser radar system, wherein the at least one laser radar system has at least one emitting device for transmitting an optical scanning beam, at least one receiving device for receiving an optical beam and outputting a corresponding output quantity, and at least one control and evaluation device. PRIOR ART

[0005] The patent document WO 2022 / 146639 A1 discloses an apparatus comprising one or more image sensors coupled to a vehicle and at least one processor. The at least one processor can be configured to acquire a plurality of individual images of a scene image using the one or more image sensors in a non-consecutive sequence, wherein the plurality of individual images each have a relative shift of the image across the plurality of individual images, and the processor performs a super-resolution computation using the plurality of individual images of the acquired scene image. The at least one processor can also be configured to accumulate color planes based on the super-resolution computation and combine the accumulated color planes using the one or more processors to generate a super-resolution image of the scene.

[0006] The technical problem addressed by the present application is to design a method, a laser radar system, a driver assistance system and a vehicle of the type mentioned at the outset, in which the performance of the laser radar system, in particular the performance in terms of angular resolution, effective range and / or update rate, can be improved. SUMMARY

[0007] According to the application, the technical problem is solved in the method by forming, for the generation of at least one individual image, at least one reception group to which at least two reception elements are correspondingly assigned, wherein the at least one reception group is defined by a hypothetical group frame which encloses a defined arrangement of reception elements of a reception field and which is displaceable along the reception field, and by combining at least a part of the output quantity of at least a part of the reception elements belonging to the same reception group into a corresponding group output quantity, wherein in the method at least two individual images are generated, between the generation of the individual images the group frame is displaced along the reception field for the at least one reception group by a predetermined displacement vector.

[0008] According to the application, at least two reception elements of a reception field having a plurality of reception elements are combined into a reception group. The reception group is defined by a hypothetical group frame which is predefinable. The group frame encloses a defined arrangement of reception elements. The arrangement of reception elements can be defined by the total number of reception elements, the number of columns and rows in which the reception elements are arranged in the reception group. The hypothetical group frame is displaceable along the reception field. In this way, the composition of the reception group can be changed by displacement of the hypothetical group frame.

[0009] At least a part of the output quantity of at least a part of the reception elements belonging to the same reception group is combined into a corresponding group output quantity. In this way, the radiation detected by the reception group can be better resolved quantitatively. The amount of radiation received, in particular the optical power received, can thus be determined precisely. Furthermore, the signal-to-noise ratio can be improved thereby. Furthermore, differences in sensitivity of the individual reception elements within the reception group, in particular faults of the individual reception elements, can be compensated.

[0010] In the method, at least two individual images are generated, between the generation of the at least two individual images the group frame is displaced along the reception field by a predetermined displacement vector. In this way, a different composition of the reception group is used for each individual image. Depending on the manner of use of the laser radar system, the spatial resolution of the radiation received by the reception device with regard to the position of the respective reception group on the reception field can thus be improved, and / or the signal-to-noise ratio for the total output quantity can be improved, and / or differences in sensitivity of the individual reception elements can be better compensated.

[0011] Overall, the application makes it possible to improve the angular resolution of a laser radar measurement without having to reduce the update rate of the receiving device or the effective range of the laser radar system when detecting a monitoring region. There is no need to increase the power of the scanning beam in order to achieve an improvement in the angular resolution. Thus, if necessary, the limits on eye safety with respect to the emitted scanning beam can be adhered to.

[0012] The at least one output quantity of at least one receiving element belonging to the same receiving group can advantageously be detected in the form of an electrical quantity, in particular in the form of a voltage. Alternatively or additionally, the at least one output quantity can be detected in the form of a value, in particular in the form of a digital value.

[0013] The at least one output quantity of at least one receiving element belonging to the same receiving group can advantageously be detected in the form of an electrical quantity, in particular in the form of a voltage. Alternatively or additionally, the at least one output quantity can be detected in the form of a value, in particular in the form of a digital value.

[0014] The receiving elements can advantageously also be referred to as pixels, in particular micro-pixels. The receiving groups can accordingly be referred to as "macro-pixels".

[0015] The receiving centers of the receiving elements can advantageously be arranged on an imaginary receiving field plane, in particular a receiving field plane. The receiving field plane can advantageously be an imaginary receiving field plane. In this way, the receiving elements can be arranged in a defined manner. The receiving field plane, in particular the receiving field plane, can advantageously be spanned by two imaginary receiving field axes, in particular perpendicular to one another. In this way, the receiving field plane can be defined simply.

[0016] The at least one receiving element can advantageously be arranged along a line extending parallel to the at least one imaginary receiving field axis. In this way, the at least one receiving element can be arranged in a row. The at least one receiving element can advantageously be arranged in an imaginary grid defined by the imaginary receiving field axes perpendicular to one another. In this way, the receiving elements can be arranged in rows and columns.

[0017] The laser radar system can advantageously be arranged in a ready-to-operate installation such that the receiving field is oriented such that imaginary lines extending parallel to a spatial horizontal line in the monitoring region are imaged spatially resolved along the direction of one of the receiving field axes. In this way, it is possible to carry out a horizontally spatially resolved monitoring of the monitoring region by means of the laser radar system.

[0018] Alternatively or additionally, the laser radar system can advantageously be arranged in a ready-to-operate installation such that the receiving field is oriented such that imaginary lines extending parallel to a spatial vertical line in the monitoring region are imaged spatially resolved along the direction of one of the receiving field axes. In this way, it is possible to carry out a vertically spatially resolved monitoring of the monitoring region by means of the laser radar system.

[0019] Advantageously, the lidar system can be arranged in the vehicle in an installation ready for operation such that the reception field is oriented such that a hypothetical line in the monitoring region which runs parallel to a vehicle plane spanned by a vehicle longitudinal axis and a vehicle transverse axis is imaged spatially resolved along the direction of one of the reception field axes. In this way, it is possible to use the lidar system for a horizontally spatially resolved monitoring of the monitoring region in the normal operation of the vehicle, in which the vehicle plane extends horizontally in space.

[0020] Alternatively or additionally, the lidar system can advantageously be arranged in the vehicle in an installation ready for operation such that the reception field is oriented such that a hypothetical line in the monitoring region which runs parallel to a vehicle vertical axis is imaged spatially resolved along the direction of one of the reception field axes. In this way, it is possible to use the lidar system for a vertically spatially resolved monitoring of the monitoring region in the normal operation of the vehicle, in which the vehicle vertical axis extends vertically in space.

[0021] Advantageously, the vehicle transverse axis, the vehicle vertical axis and the vehicle longitudinal axis can extend perpendicular to one another. In this way, a mutually perpendicular vehicle reference system can be formed.

[0022] Advantageously, the lidar system can be designed as a scanning system. Here, the monitoring region can be probed by a scanning beam, i.e. scanned. To this end, the propagation direction of the scanning beam, in particular of a scanning signal, can be deflected over the monitoring region. Here, at least one signal steering device, in particular a scanning device, a turning mirror device or the like, can be used.

[0023] Advantageously, the lidar system can be designed as a laser-based distance measuring system. The laser-based distance measuring system can have a laser, in particular a diode laser, as a signal source. By means of the laser, in particular a pulsed laser beam can be emitted as a scanning beam. By means of the laser, a scanning beam can be emitted in a wavelength range which is visible or invisible to the human eye. Correspondingly, the receiving device of the lidar system can have or consist of detectors, in particular point sensors, line sensors and / or area sensors, in particular (avalanche) photodiodes, photodiode lines, photodiode matrices, CCD sensors, active pixel sensors, in particular CMOS sensors or the like, which are suitable for the wavelength of the emitted scanning beam. The laser-based distance measuring system can advantageously be designed as a laser scanner. By means of the laser scanner, the monitoring region can be scanned by means of a pulsed laser beam, in particular a laser signal.

[0024] Advantageously, the application can be used in a vehicle, in particular a motor vehicle. Advantageously, the application can be used in a land vehicle, in particular a car, a truck, a bus, a motorcycle, a mobile robot, etc., an aircraft, in particular a flying drone, and / or a water vehicle, in particular an (underwater) drone. The application can also be used in a vehicle which can be operated autonomously or at least partially autonomously. However, the application is not limited to vehicles. The application can also be used in robotics and / or machines, in particular for construction or transport machines, such as cranes, excavators, etc., in a stationary manner.

[0025] Advantageously, the lidar system can be connected to or part of at least one electronic control device of the vehicle or machine, in particular a driver assistance system, etc. In this way, at least part of the functions of the vehicle or machine can be performed autonomously or partially autonomously using the information obtained by the lidar system.

[0026] The lidar system can be used to detect stationary or moving objects, in particular vehicles, persons, animals, plants, obstacles, ground, a lane, a road unevenness, in particular a pothole or a stone, a lane boundary, a (lane) marking, a (traffic) sign, a free space, in particular a parking space, precipitation, etc., and / or to detect movements and / or gestures.

[0027] In particular when using the lidar system in a vehicle to monitor the vehicle's environment, the "spatial horizontal" and "spatial vertical" orientations can relate to the chassis of the vehicle and thus to the driving path of the vehicle. A spatially horizontal plane of the vehicle can be spanned, in particular, by a vehicle longitudinal axis and a vehicle transverse axis. A spatially vertical direction can extend perpendicular to the spatially horizontal plane of the vehicle. Depending on the orientation of the vehicle, the spatially horizontal plane can be parallel to a geographical horizontal plane, and the spatially vertical direction can be perpendicular to the geographical horizontal plane.

[0028] In an advantageous design variant of the method, at least two individual images can be generated which are combined into a total image. In this way, the resolution, in particular the angular resolution, with respect to the receiving field can be further improved. This is achieved in that a plurality of individual images are detected, and a frame group is displaced between the individual images. By grouping the receiving elements, the radiation sensitivity in determining the individual images is increased relative to the use of only a single receiving element. By displacement of the frame group, superimposition of the individual images is achieved, so that the resolution, in particular the angular resolution, is improved. An improvement in the resolution, in particular the angular resolution, can thus be achieved without increasing the emission power or reducing the effective range of the lidar system.

[0029] In a further advantageous design of the method, a plurality of individual images can be generated in time succession, and the total image is updated with at least one newly generated individual image after the last combination, in particular continuously and / or glidingly, and / or a plurality of individual images can be generated in time succession, and at least one individual image, in particular all individual images, is processed individually.

[0030] The total image can advantageously be updated with at least one newly generated individual image after the last combination. In this way, the resolution, in particular the angular resolution, can be improved with increasing numbers of individual images.

[0031] Alternatively or additionally, the total image can advantageously be continuously and / or glidingly updated. In this way, the resolution, in particular the angular resolution, can be continuously improved.

[0032] Alternatively or additionally, at least one individual image can advantageously be processed individually. In this way, intermediate results can be obtained quickly. Here, all individual images can be processed individually. Thus, intermediate results can be called up at any time.

[0033] In a further advantageous design of the method, the magnitude of the displacement vector can be set at most to about 0.5 times, in particular 0.5 times, the extension of the group frame in the direction of the displacement vector, and / or the magnitude of the displacement vector can be set to the quotient of the extension of the group frame in the direction of the displacement vector and the number of receiving fields in the group frame in the direction of the displacement vector.

[0034] Advantageously, the magnitude of the displacement vector can be set at most to about 0.5 times the extension of the group frame. In this way, a small displacement can be achieved. Thus, the respective resolution, in particular the angular resolution, can be increased.

[0035] Alternatively or additionally, the magnitude of the displacement vector can advantageously be set to the quotient of the extension of the group frame and the number of receiving fields in the group frame in the direction of the displacement vector. In this way, a uniform superposition between the individual images can be achieved. Thereby, a uniform resolution, in particular an angular resolution, can be achieved throughout the laser radar measurement.

[0036] In a further advantageous design of the method, the displacement vector can be oriented parallel or obliquely, in particular diagonally, with respect to a receiving field axis of the receiving field. In this way, a displacement direction defined with respect to the orientation of the receiving field can be achieved.

[0037] In a further advantageous design of the method, the extension dimension of the group frame can be specified with reference to the number of receiving fields along the direction of the extension dimension, and / or the at least one receiving group has a two-dimensional arrangement of receiving elements.

[0038] Advantageously, the extension dimension of the group frame can be specified with reference to the number of receiving fields. In this way, the magnitude of the displacement vector can be specified simply as an integer. Here, the magnitude of the displacement vector represents the number of receiving fields that the group frame should respectively displace over.

[0039] Advantageously, the receiving field can have a functional sensor area for converting the optical beam, or consist of the aforementioned functional sensor area. Depending on the design of the receiving device, the receiving field can also have an edge or frame area that at least partially surrounds the functional sensor area, which is non-functional for the conversion of the optical beam.

[0040] Alternatively or additionally, the at least one receiving group can advantageously have a one-dimensional arrangement of receiving elements. In this way, the receiving group can be realized more compactly. Here, the receiving elements can be arranged along a row of the receiving field. Alternatively, the receiving elements can be arranged along a column of the receiving field.

[0041] In a further advantageous design of the method, the displacement vector can be oriented along a direction of the receiving field along which a spatial resolution of the monitoring region can be achieved by the receiving field, in particular the displacement vector can be oriented perpendicularly. In this way, the spatial resolution capability can be further improved.

[0042] Alternatively, the displacement vector can be oriented along a direction of the receiving field along which a spatial resolution of the monitoring region cannot be achieved by the receiving field. In particular, the displacement vector can be oriented horizontally. In this way, the signal-to-noise ratio with regard to the total output quantity can be improved, and / or differences in sensitivity of the individual receiving elements can be better compensated.

[0043] In a further advantageous design of the method, a plurality of receiving groups can be formed, to which respectively at least two receiving elements are correspondingly assigned, wherein the respective group frames of the at least two receiving groups have the same extension dimension. In this way, a uniform resolution can be achieved on the receiving field for individual images.

[0044] In a further advantageous design of the method, at least one individual image can be generated, which represents a spatial course of variation of at least one monitored quantity in the monitoring region in two spatial dimensions. In this way, the scene can be represented with reference to the at least one monitored quantity in at least one spatial dimension.

[0045] In a further advantageous design of the method, the at least one individual image is generated in the form of a data set and / or the at least one total image is generated in the form of a data set, wherein in the at least one data set, identifiers characterizing the reception groups correspond to the respective group output. In this way, the information of the individual images and the total image can be processed more easily, in particular by means of a suitable processor.

[0046] Advantageously, the identifiers characterizing the reception groups can be implemented as numerical values, in particular numbers or letters. In this way, the reception groups can be correspondingly assigned more easily.

[0047] In a further advantageous design of the method, a distance quantity, a direction quantity and / or a velocity quantity characterizing the distance, the direction and / or the velocity of a possibly present object within the scene in the monitoring region relative to the laser radar system and / or a power quantity characterizing the intensity of the optical echo beam generated by the scanning beam reflected on the possibly present object can be determined on the basis of the output, and / or the distance, the direction and / or the velocity of a possibly present object within the scene in the monitoring region relative to the laser radar system and / or the intensity of the optical echo beam generated by the scanning beam reflected on the possibly present object are used as monitoring quantities, and / or at least one distance image, at least one direction image, at least one velocity image and / or at least one power image are determined from the at least one individual image and / or the at least one total image, which images characterize the distance, the direction or the velocity of the detected object relative to the laser radar system and / or the intensity of the scanning beam reflected on the object and received as an echo beam. In this way, information about the scene in the monitoring region can be provided efficiently and can be explained simply. These information can thus be used, in particular, directly for controlling the autonomous or partially autonomous operation of a vehicle by means of a driver assistance system.

[0048] In a further advantageous embodiment, at least a portion of the reception elements can be implemented as single-photon avalanche diodes. In this way, low-power radiation can also be received quickly. By grouping a plurality of single-photon avalanche diodes into reception groups, the respective output of the single-photon avalanche diodes can be combined, so that the resolution with regard to the received radiation power is improved.

[0049] Single-photon avalanche diodes are referred to in English as Single-Photon Avalanche Diodes (SPAD).

[0050] Furthermore, the technical problem is solved according to the application in a laser radar system by the at least one reception device having at least one reception field with a plurality of electro-optical reception elements, and the laser radar system having at least a portion of the means for carrying out the method according to the application.

[0051] With the laser radar system it is possible, in particular, to monitor a monitoring region for objects.

[0052] The device for carrying out the method according to the application comprises means for generating individual images which characterize a scene in the monitoring region with reference to a monitoring quantity in at least one spatial dimension. The device for generating individual images is designed to detect the output quantity of the receiving elements.

[0053] Furthermore, the device for carrying out the method according to the application comprises means for defining the receiving groups by means of a predefinable hypothetical group frame. Here, the group frame encloses a defined arrangement of the receiving elements.

[0054] Furthermore, the device for carrying out the method according to the application comprises means for forming the receiving groups by means of the group frame and for correspondingly assigning the receiving elements to the receiving groups.

[0055] Furthermore, the device for carrying out the method according to the application comprises means for combining the output quantities of the receiving elements belonging to the same receiving group into a corresponding group output quantity.

[0056] Finally, the device for carrying out the method according to the application comprises means for displacing the group frame along the receiving field by a predetermined displacement vector between the generation of at least two individual images.

[0057] The device for carrying out the method according to the application can be realized in software and / or hardware.

[0058] Furthermore, the technical problem is solved according to the application in a driver assistance system which has at least a part of the device for carrying out the method according to the application.

[0059] With the driver assistance system it is possible, in particular, to operate the vehicle autonomously or partially autonomously, taking into account the information determined by the at least one laser radar system.

[0060] According to the application, the driver assistance system has at least one laser radar system, in particular a laser radar system according to the application. Advantageously, the at least one laser radar system of the driver assistance system can have at least a part of the device for carrying out the method according to the application. Since the at least one laser radar system is part of the driver assistance system, the device of the at least one laser radar system is likewise part of the driver assistance system, i.e. is also a device of the driver assistance system. This applies accordingly to the device of the vehicle which has at least one driver assistance system and / or at least one laser radar system.

[0061] Furthermore, the technical problem is solved according to the application in a vehicle having at least a part of the means for carrying out the method according to the application.

[0062] The environment of the vehicle can be scanned by the at least one laser radar system, in particular for objects. Quantities characterizing the distance, direction and / or velocity of the objects relative to the vehicle can be determined by the at least one laser radar system. Furthermore, quantities characterizing the intensity of the received beams can be determined by the at least one laser radar system. The reflectivity of the objects can be determined by the intensity of the received beams.

[0063] Advantageously, the vehicle can have at least one driver assistance system. The vehicle can be operated autonomously or partially autonomously by the driver assistance system.

[0064] Advantageously, the at least one laser radar system can be connected to the control device of the driver assistance system. Thereby, information obtained by the at least one laser radar system, in particular object information, can be transmitted to the control device of the driver assistance system. Here, at least a part of the laser radar system can be part of the driver assistance system or be realized separately from the driver assistance system.

[0065] Furthermore, the features and advantages exhibited in connection with the method according to the application, the laser radar system according to the application, the driver assistance system according to the application and the vehicle according to the application and their respective advantageous design solutions according to the application apply to each other, and vice versa. The individual features and advantages can of course be combined with each other, so that further advantageous effects beyond the sum of the individual effects can be produced. BRIEF DESCRIPTION OF DRAWINGS

[0066] Further advantages, features and details of the application result from the following description, in which embodiments of the application are explained in more detail with reference to the drawings. The person skilled in the art will also consider the features disclosed in the drawings, description and claims in isolation and in suitable further combinations as meaningful and will summarize them as such. In the drawings:

[0067] Figure 1 A front view of a vehicle having a driver assistance system comprising a laser radar system and a control device is shown;

[0068] Figure 2 A functional view of the driver assistance system of the vehicle of Figure 1 is shown;

[0069] Figure 3 A functional view of the driver assistance system of the vehicle of Figure 1 and 2A view of the illumination side of the receiving field of the receiving device of the lidar system, wherein the receiving elements of the receiving field are correspondingly assigned to the corresponding receiving groups to generate a first individual image.

[0070] Figure 4 It shows Figure 3 A view of the irradiated side of the receiving field, wherein, compared with a first individual image, the receiving group is displaced by a displacement vector to generate a second individual image;

[0071] Figure 5 It shows Figure 4 A view of the irradiated side of the receiving field, wherein, compared with the second individual image, the receiving group is displaced by the displacement vector to generate a third individual image;

[0072] Figure 6 It shows Figures 3 to 5 A view of the irradiated side of the receiving field, wherein, by way of example, they are shown in contrast. Figures 3 to 5 One of the receiving groups.

[0073] The same parts in the figure have the same reference numerals. Detailed Implementation

[0074] Figure 1 The vehicle 10, which is in the form of a car, is shown in a front view. The vehicle 10 includes a driver assistance system 12 with a lidar system 14 and a control device 16. Figure 2 A functional block diagram of a driver assistance system 12 with a lidar system 14 and a control device 16 is shown.

[0075] The lidar system 14 is exemplarily disposed in the front bumper of the vehicle 10. The field of view of the lidar system 14 is directed towards a monitoring area 18 in front of the vehicle 10 in the direction of travel. The lidar system 14 can monitor the monitoring area 18, for example, an object 20. The lidar system 14 may also be disposed in other locations on the vehicle 10 and oriented in other ways. The vehicle 10 may also have multiple identical or similar lidar systems 14, which may be disposed and / or oriented differently.

[0076] The lidar system 14 can detect stationary or moving objects 20, such as vehicles, people, animals, plants, obstacles, road irregularities such as potholes or rocks, lane boundaries, traffic signs, vacant spaces, especially parking spaces, precipitation, etc., and / or detect motion and / or gestures.

[0077] The laser radar system 14 is functionally connected to the control device 16 of the driver assistance system 12. In this way, information, for example object information, obtained by the laser radar system 14 from the monitoring region 18 can be transmitted to the control device 16. Thereby, a scenario present in the monitoring region 18 can be detected by the laser radar system 14 and characterized by corresponding information. Here, a scenario not containing an object 18 can also be characterized.

[0078] The control device 16 of the driver assistance system 14 can control functions, for example driving functions, of the vehicle 10, for example based on information obtained by the laser radar system 14, in particular. In this way, the vehicle 10 can be operated autonomously or partially autonomously.

[0079] The laser radar system 14 is designed, for example, as a scanning laser radar system. By the laser radar system 14, an optical scanning beam 22, for example in the form of a laser signal, can be transmitted into the monitoring region 18.

[0080] The scanning beam 22 can be reflected at a possible object 20 and received by the laser radar system 14 as an optical echo beam 24. Based on the scanning beam 22 and the echo beam 24, the laser radar system 14 can determine a distance, a direction and a speed of a detected object 20 relative to the laser radar system 14. Here, in a time-of-flight measurement, the distance can be determined from the time of flight of the scanning beam 22 and the echo beam 24 from the transmission of the scanning beam 22 to the reception of the echo beam 24. Furthermore, the intensity of the echo beam 24 can be detected and thereby the reflectivity of the object 20 from which the echo beam 24 originates can be determined. The intensity of the echo beam 24 can be defined, for example, by its power or energy.

[0081] If the laser radar system 14 does not detect an object 20 within the field of view 18, information about the absence of an object 20 within the field of view 18 can also be considered as object information.

[0082] As Figure 2 is shown, the laser radar system 14 comprises a transmitting device 26, a receiving device 28 and a control and evaluation device 30.

[0083] The transmitting device 26 comprises a light source, for example in the form of one or more lasers. By the light source, a laser signal can be generated as a scanning beam 22. For transmitting the scanning beam 22, the transmitting device 26 can be correspondingly controlled by the control and evaluation device 30.

[0084] Furthermore, the transmitting device 26 can have at least a part of the transmitting optics and / or a beam steering device by means of which the scanning beam 22 can be deflected into the monitoring region 18.

[0085] The receiving device 28 is connected to the control and evaluation device 30 by data and control lines.

[0086] The receiving device 28 has a receiver 32 by means of which the echo beam 24 from the monitoring region 18 can be received. The receiving device 28, i.e. the receiver 32, can be controlled and read by means of a control and evaluation device 30. Furthermore, the receiving device 28 can have receiving optics and / or, if necessary, a beam steering device. The echo beam 24 from the monitoring region 18 is focused onto the receiver 32 by means of the receiving optics and / or, if necessary, the beam steering device.

[0087] If present, the beam steering device of the transmitting device 26 can be combined with the beam steering device of the receiving device 28, if present.

[0088] The receiver 32 has a receiving field 34 which has a plurality of receiving elements 36. The receiving field 34 is shown in Figures 3 to 6 in a view from the illumination side. For the sake of simplicity and clarity, there a receiving field 34 is shown which has only 8 x 10 receiving elements 36. In practice, the receiving field 34 can also have more or fewer receiving elements 36 which can also be arranged in other formats.

[0089] The receiving elements 36 are implemented as single-photon avalanche diodes, so-called SPADs. By means of each receiving element 36 the optical echo beam 24 can be converted into a corresponding output quantity 38 in the form of an electrical signal.

[0090] The output quantities 38 can be transmitted to the control and evaluation device 30 by means of data and control lines and processed thereby. The receiving elements 36 can be "read" separately from one another. The output quantities 38 of the receiving elements 36 can thus be processed separately from one another. The output quantities 38 can also be combined purposefully.

[0091] In Figures 3 to 6 for the sake of simplicity, each receiving field 34 is shown as a square. In practice, however, the receiving field 24 can also have other shapes. Each receiving field 34 has a functional sensor region for converting the echo beam 24. Depending on the design, the receiving field 34 can also have an edge or frame region which at least partially surrounds the functional sensor region and is non-functional for the conversion of the echo beam 24.

[0092] The receiving center 40 of the receiving element 36 is arranged on an imaginary receiving field plane. In Figure 3 for the sake of clarity, only one receiving center 40 is shown. The receiving field plane is spanned by two imaginary, mutually perpendicular receiving field axes 42 and 44. In the above-mentioned embodiment, for the sake of differentiation, the receiving field axes are referred to as vertical receiving field axis 42 and horizontal receiving field axis 44.

[0093] The receiving elements 36 are arranged in an imaginary grid, which is defined by a vertical receiving field axis 42 and a horizontal receiving field axis 46. The receiving elements 36 are arranged in rows and columns.

[0094] In the depicted embodiment, the lidar system 14 is arranged in the vehicle 10 in a ready-to-run installation situation such that the receiving field 34 is oriented such that the horizontal receiving field axis 44 extends parallel to a vehicle plane 46 spanned by a vehicle longitudinal axis 48 and a vehicle transverse axis 50, and the vertical receiving field axis 42 extends parallel to a vehicle vertical axis 52. In the ready-to-run installation situation, an imaginary line in the monitoring region 18 that extends parallel to a spatial horizontal line is spatially resolved imaged onto the receiving field 34 in a direction 58 of the horizontal receiving field axis 44. An imaginary line in the monitoring region 18 that extends parallel to a spatial vertical line is spatially resolved imaged onto the receiving field 34 in a direction 58 of the vertical receiving field axis 42.

[0095] The vehicle transverse axis 50, the vehicle vertical axis 52 and the vehicle longitudinal axis 48 extend perpendicular to one another.

[0096] The following is elaborated in detail on a method for operating the lidar system 14.

[0097] In the method, the scanning beams 22 are sent into the monitoring region 18 by the emitting device 26. The receiving device 28 is activated to receive the echo beams 24.

[0098] A plurality of individual images 54 is generated. Each individual image 54 characterizes the scene in the monitoring region 18 with reference to the monitoring quantities 54, 56, 58 and 60 in two dimensions of the monitoring region 18, namely the horizontal line and the vertical line. The individual images 54 can also be referred to as “frames”.

[0099] The distance 56, the direction 58 and the velocity 60 of a possibly present object 18 within the scene in the monitoring region 18 relative to the lidar system 14 are used as monitoring quantities. In addition, the intensity 62 of the optical echo beams 24 from the object 18 in the monitoring region 18 is used as a monitoring quantity.

[0100] The individual images 54 characterize the spatial variation of the monitoring quantities 54, 56, 58 and 60 in the two spatial dimensions in the monitoring region 18, respectively. In the depicted embodiment, the individual images 54 characterize the spatial variation of the monitoring quantities 54, 56, 58 and 60 in the vertical dimension and in the horizontal dimension.

[0101] Each individual image 54 can be generated, for example, in the form of a data set. In the data set, identifiers characterizing the reception groups 64 explained below are mutually assigned to the corresponding group output quantities 76. The identifiers characterizing the reception groups 64 can be implemented as numerical values, for example, numbers or letters. The data set is processed by means of a processor of the control and evaluation device.

[0102] The generation of the individual images 54 is described below by way of example.

[0103] A plurality of reception groups 64 is formed, to which a plurality of reception elements 36 is respectively assigned in a corresponding manner. The corresponding assignment is carried out, for example, by means of a device of the control and evaluation device. The reception groups 64 each have a two-dimensional arrangement of the reception elements 36. Each reception group 64 is defined by a hypothetical group frame 66, which can be preset. The corresponding group frame 66 encloses a defined arrangement of the reception elements 36 of the reception field 34.

[0104] The vertical extension dimension 68 of the group frame 66 is specified with reference to the number of the reception fields 24 in the direction 58 of the vertical reception field axis 42. The horizontal extension dimension 70 of the group frame 66 is specified with reference to the number of the reception fields 24 in the direction 58 of the horizontal reception field axis 44.

[0105] In the embodiment shown, the vertical extension dimension 68 and the horizontal extension dimension 70 are each exemplarily 3. Each group frame 66 exemplarily contains a reception group 64 having 3 x 3 reception elements 36. In other not shown embodiments, more or fewer reception elements 36 can also be enclosed by a group frame 66 having a corresponding extension dimension in a correspondingly different arrangement.

[0106] In the embodiment shown, Figures 3 to 6 In the embodiment shown, a total of four reception groups 64 are shown for the sake of clarity only. In practice, more or fewer reception groups 64 can also be formed. The corresponding group frames 66 of the reception groups 64 have the same extension dimensions 68 and 70.

[0107] The group frames 66 can be displaced along the reception field 34 by a displacement vector 72.

[0108] The displacement vector 72 is exemplarily oriented in a direction along the reception field 34 in which a spatial resolution of the monitoring region 18 can be achieved by means of the reception field 34. In the embodiment shown, the displacement vector 72 is oriented parallel to the vertical reception field axis 42 of the reception field 34.

[0109] Alternatively, the displacement vector 72 can also be oriented in a direction along the reception field 34 in which a spatial resolution of the monitoring region 18 cannot be achieved by means of the reception field 34. Thereby, the signal-to-noise ratio with respect to the total output quantity 38 can be improved and differences in the sensitivity of the individual reception elements 36 can be compensated. Thereby, for example, a failure of individual reception elements 36 can be compensated.

[0110] The magnitude of the displacement vector 72 is at most preset to about 0.5 times the extension dimension 68 of the group frame 66 in the direction 58 of the displacement vector 72. The magnitude of the displacement vector 72 is preset to the quotient of the extension dimension 68 of the group frame 66 and the number of reception fields 24 within the group frame 66 along the direction of the displacement vector 72. In the shown embodiment, the group frame 66 comprises a matrix of 3 x 3 reception elements 36. The magnitude of the displacement vector 72 is preset to one third of the extension dimension 68 of the group frame 66. The magnitude of the displacement vector 72 corresponds to the extension dimension 74 of the reception field 34 in the direction 58 of the displacement vector 72.

[0111] For generating the individual images 54, the output quantities 38 of the reception elements 36 are detected.

[0112] The output quantities 38 of the reception elements 36 belonging to the same reception group 64 are combined into a respective group output quantity 76. In the shown embodiment, thus four group output quantities 76 are generated for the exemplary four reception groups 64. The individual images 54 are composed of the group output quantities 76 of all reception groups 64.

[0113] After generating one individual image 54 and before generating the next individual image 54, the group frame 66 of the reception group 64 is displaced along the reception field 34 by the displacement vector 72. Thereby a re-correspondence of the reception elements 36 to the reception group 64 is achieved.

[0114] The three individual images 54 are generated successively in time, exemplarily. Figure 3 The layout of the group frame 66 and the respective reception group 64 for the first individual image 54 is shown. Figure 4 The layout of the group frame 66 and the respective reception group 64 for the second individual image 54 is shown. Figure 5 The layout of the group frame 66 and the respective reception group 64 for the third individual image 54 is shown. Figure 6 The group frames of the three successively individual images 54 are shown. For the sake of clarity, only one of the four group frames 66 is shown schematically in three positions.

[0115] Since the magnitude of the displacement vector 72 is smaller than the perpendicular extension dimension 68 of the group frame 66 in the direction of the displacement vector and thus smaller than the perpendicular extension dimension of the reception group 64 in the direction of the displacement vector, as Figure 6 The reception groups 64 of the successively individual images 54 are superimposed in one row of reception elements 36, respectively, as shown. The extension dimension 78 of the superimposition of the reception groups 64 between the individual images 54 is equal.

[0116] The individual images 54 generated in succession are combined into a total image 80. The total image 80 has the form of a data set corresponding to the individual images 54. The total image 80 is updated by the newly generated individual images 54 after each last combination in each case. The total image 80 is thus continuously updated. The updating can take place slidingly.

[0117] Optionally, the individual or all individual images 54 can be processed separately.

[0118] By combining the individual images 54, the resolution with respect to the reception field 34 is improved. By grouping the reception elements 36, the radiation sensitivity is increased in determining the individual images 54. By superimposition of the individual images 54, the resolution is improved.

[0119] On the basis of the group output quantity 76 of the total image 80, distance quantities, direction quantities and velocity quantities are determined. The distance quantities characterize the distance 56 of a possibly present object 18 in the scene in the monitoring region 18 relative to the laser radar system 14, the direction quantities characterize the direction 58 of a possibly present object 18 in the scene in the monitoring region 18 relative to the laser radar system 14 and the velocity quantities characterize the velocity 60 of a possibly present object 18 in the scene in the monitoring region 18 relative to the laser radar system 14. Furthermore, on the basis of the group output quantity 76 of the total image 80, power quantities are determined, which characterize the intensity 62 of the optical echo beam 24 produced by the scanning beam 22 reflected by a possibly present object 18.

[0120] Furthermore, from the total image 80, a distance image containing distance quantities, a direction image containing direction quantities, a velocity image containing velocity quantities and a power image containing power quantities are determined. The distance image characterizes the velocity 60 of a detected object 18 relative to the laser radar system 14, the direction image characterizes the direction 58 of a detected object 18 relative to the laser radar system 14 and the velocity image characterizes the velocity 60 of a detected object 18 relative to the laser radar system 14. The power image characterizes the power of the received echo beam 24.

[0121] By means of the distance image, the direction image, the velocity image and the power image, information about the scene detected by the laser radar system 14 in the monitoring region 18 is provided. This information can be used directly by the driver assistance system 12 for controlling the autonomous or partially autonomous operation of the vehicle 10.

Claims

1. A method for operating a lidar system (14), particularly a lidar system (14) for a vehicle (10), wherein, At least one optical scanning beam (22) is generated by at least one transmitting device (26) of a lidar system (14), and said at least one scanning beam (22) is sent to the monitoring area (18) of the lidar system (14) to generate at least one individual image (54), said individual image characterizing the scene in the monitoring area (18) with reference to at least one monitored quantity (56, 58, 60, 62) in at least one spatial dimension, wherein, in order to generate at least one individual image (54), the output quantity (38) of at least two electro-optic receiving elements (36) of the receiving field (34) of the receiving device (28) of the lidar system (14) is detected, said receiving field having a plurality of receiving elements (36), characterized in that, in order to generate at least one individual image (54) At least one receiving group (64) is formed, and at least two receiving elements (36) are correspondingly assigned to the receiving group. The at least one receiving group (64) is defined by a pre-defined hypothetical group frame (66) that surrounds a defined layout of the receiving elements (36) of the receiving field (34) and is displaceable along the receiving field (34). At least a portion of the outputs (38) of at least a portion of the receiving elements (36) belonging to the same receiving group (64) are merged into a corresponding group output (38). At least two separate images (54) are generated in the method. Between the generation of the at least two separate images, the group frame (66) is displaced along the receiving field (34) with a predetermined displacement vector (72) relative to the at least one receiving group (64).

2. The method according to claim 1, characterized in that, At least two separate images (54) are generated, and the separate images are combined into a total image (80).

3. The method according to claim 1 or 2, characterized in that, Multiple individual images (54) are generated sequentially in time, and the total image (80) is updated with at least one newly generated individual image (54) after the last combination, in particular the total image (80) is updated continuously and / or slidingly, and / or multiple individual images (54) are generated sequentially in time, and at least one individual image (54), in particular all individual images (54) are processed individually.

4. The method according to any one of the preceding claims, characterized in that, The magnitude of the displacement vector (72) is preset to be at most about 0.5 times, especially 0.5 times, the extension dimension (68) of the frame group (66) in the direction of the displacement vector (72), and / or the magnitude of the displacement vector (72) is preset to be the quotient of the extension dimension (68) of the frame group (66) and the number of receiving fields (34) in the frame group (66) along the direction of the displacement vector (72).

5. The method according to any one of the preceding claims, characterized in that, The displacement vector (72) is oriented parallel to or inclined to, in particular diagonally, relative to the receiving field axis (42) of the receiving field (34).

6. The method according to any one of the preceding claims, characterized in that, The extension dimensions (68, 70) of the group frame (66) are specified with reference to the number of receiving fields (34) in the direction of the extension dimensions (68, 70), and / or at least one receiving group (64) has a two-dimensional layout of receiving elements (36).

7. The method according to any one of the preceding claims, characterized in that, The displacement vector (72) is oriented along the direction of the receiving field (34) in which spatial resolution of the monitoring area (18) can be achieved by the receiving field (34), and the at least one displacement vector (72) is oriented particularly vertically.

8. The method according to any one of the preceding claims, characterized in that, Multiple receiving groups (64) are formed, and at least two receiving elements (36) are respectively assigned to the receiving groups, wherein the corresponding group frames (66) of at least two receiving groups (64) have the same extension dimensions (68, 70).

9. The method according to any one of the preceding claims, characterized in that, At least one individual image (54) is generated, which represents the spatial variation of at least one monitored quantity (56, 58, 60, 62) in the monitored area (18) in two spatial dimensions.

10. The method according to any one of the preceding claims, characterized in that, At least one individual image (54) is generated in the form of a dataset and / or at least one total image (80) is generated in the form of a dataset, wherein, in at least one dataset, an identifier representing a receiving group (64) corresponds to a corresponding group output quantity (38).

11. The method according to any one of the preceding claims, characterized in that, Based on the output (38), determine the distance (56), direction (58), and / or velocity (70) of a possible object (20) in the scene within the monitoring area (18) relative to the lidar system (14), and / or the power quantity characterizing the intensity (62) of the optical echo beam (24) generated by the scanning beam (22) reflected by the possible object (20), and / or The distance (56), orientation (58), and / or velocity (60) of a possible object (20) within the scene in the monitoring area (18) relative to the lidar system (14) are used as monitoring parameters, and / or the intensity (62) of the optical echo beam (24) generated by the scanning beam (22) reflected by the possible object (20) is used as a monitoring parameter, and / or From at least one individual image (54) and / or at least one total image (80), at least one distance image, at least one direction image, at least one velocity image and / or at least one power image are determined to characterize the distance (56), direction (60) or velocity (58) of the detected object (20) relative to the lidar system (14) and / or the intensity (62) of the scanning beam (22) reflected on the object (20) and received as an echo beam (24).

12. The method according to any one of the preceding claims, characterized in that, At least a portion of the receiving element (36) is implemented as a single-photon avalanche diode.

13. A lidar system (14), particularly a lidar system (14) for a vehicle (10), the lidar system having at least one transmitting device (26) for transmitting an optical scanning beam (22) into a monitoring area (18), at least one receiving device (28) for receiving the optical beam (24) and outputting a corresponding output quantity (38), and at least one control and analysis device (30) for controlling the at least one transmitting device (26) and the at least one receiving device (28) and processing the output quantity (38) output by the at least one receiving device (28), characterized in that, The at least one receiving device (28) has at least one receiving field (34) with a plurality of electro-optic receiving elements (36), and the lidar system (14) has at least a portion of a device for performing the method according to any one of claims 1 to 12.

14. A driver assistance system (12) having at least one lidar system (14), particularly at least one lidar system (14) for a vehicle (10), wherein the at least one lidar system (14) has at least one transmitting device (26) for transmitting an optical scanning beam (22), at least one receiving device (28) for receiving the optical beam (24) and outputting a corresponding output quantity (38), and at least one control and analysis device (30), characterized in that, The driver assistance system (12) has at least a portion of the device for performing the method according to any one of claims 1 to 12.

15. A means of transport (10) having at least one lidar system (14), wherein, The at least one lidar system (14) has at least one transmitting device (26) for transmitting an optical scanning beam (22), at least one receiving device (28) for receiving an optical beam (24) and outputting a corresponding output quantity (38), and at least one control and analysis device (30), characterized in that the vehicle (10) has at least a portion of the device for performing the method according to any one of claims 1 to 12.

Images