Method and device for determining a degradation of environment detection systems of vehicles in a vehicle fleet

Abstract

The invention relates to a method and a device for determining the aging and / or degradation of environment detection systems (41, 42) of automatically driving vehicles (A1, A2) of a vehicle fleet, wherein each of the vehicles (A1, A2) comprises at least one environment detection system (41, 42) in order to detect and / or locate objects in the environment of the vehicle (A1, A2), comprising the steps of: mutual detection of two automatically driving vehicles (A1, A2) upon encounter, wherein each of the automatically driving vehicles (A1, A2) generates a time stamp (TR1, TR1', TR1'', TR2) which indicates the time on a common time scale (101, 102) at which it detected the other automatically driving vehicle (A1, A2) with its own at least one environment detection system (41, 42), wherein detection information is assigned to each time stamp (TR1, TR1', TR1'', TR2). become,wherein the detection information comprises at least sensor characterization data of the at least one environment detection system (41, 42) used to detect the time stamps (TR1, TR1', TR1'', TR2); determining at least one time difference (ΔTR1, ΔTR1', ΔTR1'', ΔTR2) based on the detected time stamps (TR1, TR1', TR1'', TR2), wherein the at least one time difference (ΔTR1, ΔTR1', ΔTR1'', ΔTR2) is assigned difference information based on the detection information of the time stamps (TR1, TR1', TR1'', TR2), which difference information comprises at least the sensor characterization data of the environment sensors (41, 42) used to detect the time stamps (TR1, TR1', TR1'', TR2); determining degradation values for the individual environment detection systems based on the at least one time difference (ΔTR1, ΔTR1', ΔTR1'', ΔTR2);Outputting and / or providing the degradation values.,

Description

The invention relates to the aging and degradation of environment detection systems, in particular automatically driving vehicles of a fleet of vehicles, and in particular to the detection of such degradation.Various components of environmental sensing systems may age over their lifetime, which may result in a safety risk due to loss of reliability and / or reduction in performance of the environmental sensing system. The aging can be attributed, for example, to undesired changes in the position and / or properties of individual components of the environment detection system, for example optical components such as lenses. Thus, known reasons for age-related range loss in lidar sensor systems are due to changes in a position and / or properties of a lens, so that incident light impinges on an optical detector in a deteriorated manner. For example, reliable environment recognition may be impaired if the position of a component changes with respect to another component of the environment detection system, for example a detector. Causes of the changes in position and / or properties may include temperature variations that may lead to deformation of the components and / or to the change of fasteners, adhesives, etc. Lens movements occur with different sensors to different extents and are generally nonlinear. Moreover, a power loss of a laser diode may result in a decrease in the range.In addition, in correspondingly configured environment detection systems, active components, for example emitters for emitting electromagnetic waves, such as in the infrared light range or in the radar frequency range, can also age, which can lead to a degradation of the emittable power.U.S. Pat. No. 9,274,525 B1 describes methods for determining a sensor degradation by an active control of an autonomous vehicle. Sensor readings of an autonomous vehicle sensor are determined to generate a baseline. A movement characteristic of the autonomous vehicle, for example speed or position, is changed and the sensor supplies corresponding further sensor measurement values. Further state information can be derived from the further sensor measurement values and compared with expected state information from the baseline. From a result of the comparison, it can be determined whether the sensor is aged.DE 10 2021 133 584 A1 describes a surroundings sensor system which has a detector unit which is designed to detect electromagnetic waves from a surroundings of the surroundings sensor system during a sequence of successive detection periods and to generate detector signals on the basis thereof. A processing unit of the environment sensor system is configured to generate a sensor data set for each detection period based on the detector signals, which sensor data set represents the environment of the environment sensor system, and to detect an object in the environment based on the sensor data sets and to track it for a part of the sequence of detection periods. The processing unit is configured to determine that the object is not detectable according to a predefined detection condition based on a sensor dataset of a further detection period following the part of the sequence, to determine a maximum distance of the object from the environment sensor system during the part of the sequence, to determine and store a measure of aging of the environment sensor system based on the maximum distance.DE 10 2018 008 903 A1 relates to a method for determining a visibility range of a beam-based sensor of a vehicle for detecting the environment. Sensor beams with known intensity are emitted by means of the beam-based sensor, reflections of the sensor beams being detected by means of the sensor and a reflection intensity being evaluated, a measured distance and the reflection intensity being linked to one another.U.S. Pat. No. 11,327,501 B1 describes methods and systems for determining sensor degradation by active control of an autonomous vehicle. The determination of sensor wear may include obtaining sensor measurements from an autonomous vehicle sensor and determining baseline state information from the obtained sensor measurements. A motion characteristic of the autonomous vehicle, such as speed or position, may then be changed. The sensor may then receive additional sensor readings and second state information may be determined from these additional sensor readings. Information about the expected state can be determined from the information about the initial state and the change in the movement features of the autonomous vehicle. A comparison can then be made between the expected state information and the second state information. Based on this comparison, it can be determined whether the sensor has deteriorated.DE 10 2018 127 059 A1 relates to a method for checking at least one environment detection sensor of a vehicle. The vehicle is located in a digital map, features of stored stationary objects of a surrounding area of the vehicle that are expected to be detected by the surrounding area detection sensor are identified in the digital map, and the surrounding area of the vehicle is detected by the surrounding area detection sensor, wherein a degradation of the surrounding area detection sensor is inferred if the features that are expected to be detected are not detected by the surrounding area detection sensor or if features that are actually detected by the surrounding area detection sensor deviate greatly from the features that are expected to be detected.The object of the present invention is to reliably quantify aging or degradation effects of environment detection systems, for example of lidar or radar sensor systems, early on, in particular insofar as a maximum range of the environment detection system is influenced. The method should manage without calibration as much as possible. In this way, it can be achieved, for example, that a vehicle is imposed a speed limit at an early stage for safety reasons in accordance with the state of environment detection systems and / or the repair or the exchange of environment detection systems are initiated in good time. It is also an object to provide a corresponding device and devices for vehicles which enable or support such a degradation or aging determination.The object is achieved according to the invention by a method having the features of claim 1, an apparatus having the features of claim 12 and a detection device having the features of claim 16. Advantageous embodiments of the invention are evident from the dependent claims.Basic idea of the inventionThe invention is based on the concept of using meetings of, in particular automatically driving, vehicles of a vehicle fleet in order to evaluate the detection properties of the environment sensor system relative to one another. For this purpose, the times at which the vehicles facing one another detect one another are determined. A time difference between the two times can be used as a measure to find out whether the environment detection system is degraded and / or aged with respect to its desired detection. In order to make possible an evaluation, detection information is assigned to the time stamps which indicate when a surroundings detection system of one vehicle has detected the respective other vehicle. These comprise at least details which characterize the environment detection system with the aid of which the detection is carried out. On the basis of the recorded time stamps, time differences are determined to which difference information is assigned which at least comprise the sensor characterization data of the environment sensors used for recording the time stamps. A degradation value is determined on the basis of the time differences, which degradation value is output and provided. This can be used, for example, to limit a permissible maximum speed of the automatically driving vehicle, provided that a degradation above a specific threshold value is detected. The degradation value is preferably determined on the basis of a comparison with threshold values or on the basis of a statistical comparison of a multiplicity of detected time differences for the same type of environment detection system.DefinitionsThe environment detection system is understood to be any vehicle-based system which is capable of detecting objects in the environment and identifying them as such objects and associating them with a distance from the environment detection system. For this purpose, it is not necessary for the respective environment detection system to unambiguously identify an object. Rather, it is only necessary that an object is detected. Surroundings detection systems of this type are, in particular, ultrasonic-based distance sensors, lidar systems, radar systems, but also three-dimensional camera systems, which can detect a distance from objects. In any case, it is necessary for the environment detection system to be able to ascertain a relative distance of the detected object from the own automatically driving vehicle.A simple camera for capturing an image is generally not sufficient as a surroundings detection system, since it is generally not able to unambiguously associate a distance with the object captured in the image information. However, a camera system which captures successive images can very well represent a surroundings detection system together with an evaluation algorithm, provided that the distance to individual captured objects in the camera images can be determined on the basis of the own movement performed between the image capture and the captured camera images on the basis of the evaluation algorithm.Degradation is considered to be any degradation in terms of the detection sensitivity and / or detection accuracy of a surroundings detection system with respect to its nominal specification. In this case, it is immaterial on which the deterioration is attributable.Sensor characterization data are understood to be all details that describe a surroundings detection system. This includes, for example, details about the type, model and / or series of the environment detection system, but also current settings and operating parameters of the environment detection system. In addition, it comprises an identification of the individual environment detection system, for example a serial number or the like or an identifier of the vehicle in which the corresponding environment detection system is installed. However, it also includes data which indicate the measuring principle according to which the environment detection system carries out the detection. These include information such as radar system, lidar system, ultrasonic-based distance warning system, 3D camera system or the like.A statement is understood as a degradation value which represents a measure of degradation. In the simplest case, the degradation value can comprise the indication "is degraded / is not degraded". Preferably, however, an indication is used as the degradation value, which indicates a deviation from a setpoint value in relation to the setpoint value. If a radar system is designed, for example, to reliably detect objects at a distance of 200 m from the vehicle, then an indication in meters, for example, can express as a degradation value for such a radar system how far a detection limit of a surroundings detection system deviates from the setpoint detection distance. If vehicles and objects are detected reliably only at a distance of 150 m from the vehicle, the degradation value could be, for example, -50. If, on the other hand, the radar system is able to reliably detect objects at a distance of more than 200 m, for example 225 m, the degradation value could accordingly have the value +25. Different scales for the degradation values depending on the types of environment detection systems, but different degradation scales can also be used for the same type of environment detection systems. Thus, the degradation values can also indicate, for example, the detection limit for a radar system as a relative value to the nominal detection limit. In the above-mentioned example, for example, in the case of a radar system which nominally detects objects at a distance of 200 m, which currently only detects objects at a distance of 150 m permissibly, a degradation value of 75% would have to be assigned. Alternatively, the value could also be stated as -25%.An automatically driving vehicle is a vehicle that participates in road traffic in a self-controlled manner without a constant supervision of a human person by an automated system. This does not exclude that in special situations a human person, for example in a traffic center, is temporarily involved in the control. In the prior art, such vehicles are sometimes also referred to as autonomous vehicles.Preferred EmbodimentsThe invention provides a method for determining the aging and / or degradation of environment detection systems, in particular automatically driving vehicles of a fleet of vehicles, wherein each of the vehicles comprises at least one environment detection system in order to detect and / or locate objects in the environment of the vehicle therewith, comprising the steps of:mutual detection of two, in particular automatically driving, vehicles in a encounter, wherein each of the, in particular automatically driving, vehicles generates a time stamp which indicates the time on a common time scale at which it detected the other, in particular automatically driving, vehicle with its own at least one environment detection system, wherein detection information is assigned to each time stamp, wherein the detection information at least corresponds to a common time scale.sensor characterization data of the at least one environment detection system used for detecting the time stamps;determining at least one time difference based on the recorded time stamps, wherein difference information comprising at least the sensor characterization data of the environment detection systems used for detecting the time stamps is assigned to the at least one time difference based in each case on the detection information of the time stamps, determining degradation values for the individual environment detection systems based on the at least one time difference;outputting and / or providing the degradation values.The advantage of the method is that the required measured values can be recorded during the normal driving operation of the vehicles of the fleet of vehicles, which vehicles are in particular automatically driving. Moreover, no calibration is necessary. In particular, if a large number of such encounters are evaluated, a degradation can be detected by the fact that a detection of the other vehicle in each case follows the detection of the own vehicle by the other vehicle at a later point in time than the detection of the own vehicle.Furthermore, a device for determining the aging and / or degradation of at least one environment detection system of at least one, in particular automatically driving, vehicle of a fleet of vehicles is provided, wherein each, in particular automatically driving, vehicle of the fleet of vehicles comprises at least one environment detection system in order to detect and / or locate objects in the environment of the vehicle therewith, and a detection device which is designed to detect a time stamp which indicates the time on a common time scale at which the respective, in particular automatically driving, vehicle has first detected another of the, in particular automatically driving, vehicles with its own at least one environment detection system, wherein the detection devices are designed to assign detection information to each time stamp, wherein the detection information comprises at least sensor characterization data of the at least one environment detection system used for detecting the time stamp; wherein the apparatus comprises at least the detection device of the at least one vehicle and an evaluation device which is designed to record time stamps and associated detection information of the detection devices of the at least one vehicle and at least one other of the, in particular automatically driving, vehicles of the fleet of vehicles, wherein the evaluation device comprises a differentiation device which is designed to determine at least one time difference on the basis of the recorded time stamps, wherein the at least one time difference is assigned difference information which comprises at least the sensor characterization data of the environment sensors used for recording the time stamps on the basis of the detection information of the time stamps, and a degradation value determination unit for determining a degradation value on the basis of the determined at least one time difference and an output device for outputting the degradation value.In order to be able to include a vehicle, in particular a vehicle that is automatically driving, in the fleet of vehicles, this at least requires a detection device. Thus, a detection device for a device for determining the aging and / or degradation of at least one environment detection system of at least one, in particular automatically driving, vehicle of a fleet of vehicles is also provided, wherein the detection device either comprises a time stamp generation device for providing time stamps on a time scale common to the, in particular automatically driving, vehicles of the fleet of vehicles or can be coupled to such a time stamp generation device and can additionally be coupled to at least one environment detection system of an, in particular automatically driving, vehicle of the fleet of vehicles, wherein the at least one environment detection system is configured to detect and / or locate objects in the environment of the one vehicle, wherein the detection device is configured to detect a time stamp which indicates the time on the common time scale at which another, in particular automatically driving, vehicle of the fleet of vehicles, Vehicle having the coupled at least one environment detection system of the one vehicle was first detected during a encounter, wherein the detection devices are designed to assign detection information to each time stamp, wherein the detection information comprises at least sensor characterization data of the at least one environment detection system used for detecting the time stamp, wherein the detection device is furthermore designed to transmit the detected time stamps and assigned detection information to an evaluation device.In order to be able to carry out the determination, in one embodiment the time stamps and detection information are exchanged between the vehicles, in particular vehicles which are travelling automatically, by means of car-to-car communication. Each vehicle can then determine the time difference as the difference between the time stamp of the other, in particular automatically driving, vehicle and the time stamp of the own vehicle without limiting generality. If the time stamp of the own vehicle is in each case temporally after the time stamp of the other vehicle, this indicates a degradation of the environment detection system. It is understood by the person skilled in the art that, due to the different range, in particular of different types of detection system, preferably only detection systems of the same type are compared with one another. However, since vehicles, in particular automatically driving vehicles, generally comprise different or redundant environment detection systems, it is possible to determine time differences and degradation values for the different systems.In one embodiment, the evaluation device is in the at least one, in particular automatically driving. The one detection device of the at least one vehicle is also arranged in the vehicle. The vehicle, which is in particular automatically driving, can therefore itself determine the degradation and / or aging of its at least one environment detection system.In another specific embodiment, the time stamps and detection information are alternatively or additionally transmitted to at least one central server and time differences and degradation values are alternatively or additionally ascertained in the central server. As a result, so-called swarm data can be determined, in particular for individual surroundings detection systems.Accordingly, in one embodiment, the evaluation device is embodied in a central server of the fleet of vehicles. This may alternatively or additionally be the case.In a further embodiment, the apparatus additionally comprises the detection device of the at least one other vehicle, in particular a vehicle which is automatically driving. In this embodiment, the apparatus thus comprises at least two detection devices in different vehicles and at least one evaluation device. However, more evaluation devices can also be provided, for example one evaluation device in each of the vehicles in addition to an evaluation device in a central server, if appropriate.The vehicles, which are in particular automatically driving, preferably identify an imminent encounter on the basis of route data. For example, this can be done in that the vehicles communicate their route information to one another via car-to-car communication and a encounter can be derived from this. It is likewise possible for the encounters to be noted in the route data and to be entered there by an entity planning the routes of the vehicles. As a result, the vehicles are prepared to ascertain the time stamps for their environment detection systems when they are encountered by the corresponding other vehicle, in particular a vehicle which is automatically driving.It is understood by the person skilled in the art that detected radar echoes can be reliably assigned to the corresponding other oncoming vehicle, in particular automatically driving vehicle, for example, by tracking the corresponding radar echo and matching it with the transmitted route information of the oncoming vehicle. However, other algorithms and methods may also be used to ensure that a first detection of the oncoming vehicle is performed based on measurement signals actually caused by the oncoming vehicle.In a preferred embodiment, it is further provided that the vehicles, which are in particular automatically driving, buffer at least sensor measurement data of the at least one environment detection system in a short-time memory in order to determine a time stamp for the detection of the other vehicle, which is in particular automatically driving, on the basis of the stored sensor measurement data, if the vehicle only detects the encounter with the other vehicle if the at least one environment detection system has already detected the other vehicle system. Such a system can be used, for example, without a route planning. If, for example, a camera evaluation takes place to record identifiers attached to the vehicle that make it possible to identify an oncoming vehicle, the corresponding sensor measurement data of the environment recording systems can be evaluated in order to generate the time stamps and to exchange them with the oncoming detected vehicle and / or a central server if the detected vehicle, in particular a vehicle that is automatically driving, belongs to the same fleet. In this way, in particular, unscheduled random encounters can be included in the evaluation. The sensor measurement data are preferably buffer-stored together with time stamps in the short-term memory.As a rule, it is preferred to plan the meetings beforehand on the basis of the route planning. In this way, it can be achieved in particular that the encounter occurs under favorable environmental conditions, for example on a straight, planar roadway. In a preferred embodiment, the route data of at least one of the vehicles involved in the encounter, in particular automatically driving, are therefore adapted in order to bring about a encounter. Adaptation is understood here to mean the change of the travel route compared to a travel route planning which results from other requirements, for example a starting point and destination point, and other requirements, such as, for example, a travel route which is as time-saving as possible.The route planning is preferably influenced by the at least one central server or executed by the latter for the one or both, in particular automatically driving, vehicles. This allows optimum meeting conditions to be established at suitable locations for meeting and at optimum times.In this case, route planning preferably comprises not only trajectory planning, but also driving-dynamic specifications, such as, for example, a speed, acceleration, switching vehicle lighting on / off and / or other vehicle systems, which can influence a detection of the respective other vehicle, in particular automatically driving vehicle.In the course of the route planning, negative weights can be assigned to spatial and temporal route extensions and time periods that have elapsed since past encounters for a vehicle can be provided with a positive weight, wherein negative weights counteract a route replanning for bringing about a encounter and positive weights promote a replanning for bringing about a encounter. This makes it possible to ensure that the individual, in particular automatically driving, vehicles plan meetings with other, in particular automatically driving, vehicles of the fleet of vehicles into their routes at regular intervals in order to ensure reliable checking of the degradation of the environment detection systems.It is understood that a vehicle, in particular an automatically driving vehicle, generally determines time stamps for a plurality of its environment detection systems, which time stamps respectively indicate when the corresponding environment detection system has detected the other vehicle, in particular an automatically driving vehicle. Thus, in the event of a encounter, the various surroundings detection systems of the vehicle can be compared with one another and checked for degradations.In order to be able to make quantitative statements about the degradation on the basis of the time differences, in particular, it is advantageous if meeting information items detected are added to the detection information items, said meeting information items comprising in particular a vehicle speed, a vehicle acceleration, a determined vehicle distance, a signal strength of the transmitted sensor signal, a signal strength of the received sensor signal, a signal quality of the sensor signal, e.g. a signal-to-noise ratio, an environmental brightness indication, an orientation in space, lane information in the case of roads having a plurality of lanes per direction, and information items about weather conditions, a geoposition, a temperature, a time of day, a traffic volume, etc. In this case, individual combinations of the listed, non-concluding list can be added as meeting information to the acquisition information. In particular, the vehicle speeds and accelerations are suitable for associating the determined time difference with a distance or distance by which the detection thresholds of the environment detection sensors differ from one another.Furthermore, in some embodiments, provision is made for object detection information to be added to the detection information, said object detection information comprising information about the detection of at least one object in the meeting environment with the at least one detection system or the one other detection system of the vehicle, in particular automatically driving. As a result, the environment detection of the two, in particular automatically driving, vehicles can be validated and compared for external objects.If a time stamp is likewise detected in each case for the object detection, which time stamp does not necessarily have to correspond to the first detection of the object, then a distance of the respective vehicle from the object and a relative speed can generally be determined and specified on the basis of further evaluations of this time stamp. The evaluation can thereby be further improved. In addition, the environment detection of objects can be compared with the mutual vehicle detection.The detection information or the difference information derived therefrom, which can comprise all details of the detection information, is preferably included in the determination of the degradation value or values. For example, a tolerated time difference for the different time detection, which in the case of identical surroundings sensor systems were used for the time stamp detection, is preferably dependent on the relative speed. For example, speed information of the vehicles included in the detection information and subsequently included in the difference information is included for the degradation value derivation. Other supplementary detection information, for example acceleration, temperature, weather conditions such as rain, fog, etc., have respective other influences and are accordingly taken into account in some embodiments. The temperature can influence, for example, a measurement accuracy of a surroundings detection system, rain can influence, for example, a signal-to-noise ratio and / or a range, etc.The features described for the method can be used analogously for the development of the apparatus and / or detection device in any combination. Analogously, the features described for the apparatus and / or the detection device can be used for the development of the method.The invention is explained in more detail below with reference to a drawing. The following are shown here: FIG. 1 shows a schematic illustration of a meeting of two automatically driving vehicles; FIG. 2 shows a graphical representation of the detection times of the environment sensors of the automatically driving vehicles in the event of different degradations; and FIG. 3 shows a schematic illustration for a functional relationship of a threshold value for determining a speed-dependent degradation threshold value.In FIG. 1, a straight road 10 with two lanes 11, 12 is schematically shown. On the lane 11, an automatic driving vehicle A1 travels at a speed V1 from left to right in the figure. Another automatic driving vehicle A2 travels on the oncoming lane 12 at a speed V2in the opposite direction. The automatically driving vehicles A 1, A 2 are each configured with communication systems 21, 22, via which they are connected to a central server 30 in terms of communication technology, as is indicated by the flashes 31, 32. In the embodiment shown, the central server is designed to carry out the respective route planning for the automatically driving vehicles A 1, A 2. The automatic driving vehicle A 1 and the automatic driving vehicle A 2 move according to the route information transmitted thereto from the central server 30 via the communication devices 21, 22, respectively. The meeting on the road section 10 shown is intended in plan.The automatically driving vehicle A 1 and the other automatically driving vehicle A 2 each comprise a surroundings detection system 41 or 42, respectively. The automatically driving vehicle A 1 and the other automatically driving vehicle A 2 can additionally comprise further surroundings detection systems, not shown here. For reasons of simplification, only one environment detection system for each of the automatically driving vehicles A 1, A 2 is shown and considered here. The environment detection systems 41, 42 designed as radar systems emit electromagnetic radiation, which is indicated by dashed lines 51, 52. These are partially reflected at the respectively approaching automatically driving vehicle A 1, A 1 and detected by the respective environment detection system 41, 42 which has emitted the radiation. The automatically driving vehicle A 1 and the automatically driving vehicle A 2 each generate a time stamp TR 1 and TR 2, which respectively indicate when (TR 1) the first automatically driving vehicle A 1 has detected the other automatically driving vehicle A 2 for the first time with its environment detection system or when (TR 2) the other automatically driving vehicle A 2 has detected the one automatically driving vehicle A 1 for the first time with its environment detection system 42.Each of the vehicles A 1, A 2 comprises a detection device 61, 62, respectively. These are designed to record the time stamp TR 1, TR 2 when the environment detection system 41, 42 respectively coupled thereto first comprises the respective other automatically driving vehicle A 1, A 2. For this purpose, each of the detection devices 61, 62 can comprise a time stamp generating device 71, 72. This can be designed, for example, as a quartz watch. The common time scale may be the general time. The time stamp generating device 71, 72 is preferably synchronized via received signals. For synchronization, a GPS signal or other global satellite navigation system signal may be used. However, an NTP server that exchanges messages according to the network time protocol or a PTP server that exchanges messages according to the precision time protocol can also be used. Alternatively to the time stamp generating device 71, 72 in or on the detection device 61, 62, exchanged messages or data packets can also be used as time stamps themselves, for example according to one of the protocols mentioned, or can be derived from their content. For this purpose, the communication devices 21, 22 are used, which can also be correspondingly a component of the respective detection devices 61, 62. Thus, for example, a PTP server and / or an NTP server can be designed as a time stamp generating device 33 in the central server 30.In one specific embodiment, the automatically driving vehicles A 1, A 2 each include an evaluation device 81, 82, which each include a difference formation device 83, 84 and a degradation value determination unit 85, 86, as well as an output device 87, 88, which derive the corresponding degradation values derived from this from the time differences ΔTR 1=TR 2-TR 1 or ΔTR 2=TR 2-TR 1 and finally output it. The output device can be designed, for example, as an interface or also as a display element in a cockpit (both not shown) of the respective vehicle A 1, A 2.Alternatively or additionally, an evaluation device 34 can be formed in the central server 30, which also comprises a difference formation device 35, a degradation value determination unit 36 and an output device 37.In one specific embodiment, device 1 for determining degradation / aging of a surroundings detection system includes detection device 61 and evaluation device 81 of one automatically driving vehicle A 1.In another embodiment, the apparatus 1' comprises, in addition or as an alternative to the evaluation device 81 of the embodiment of the apparatus 1, the evaluation device 34 of the central server 30.In yet another embodiment, the apparatus 1" additionally comprises the detection device 62 as an alternative or in addition to the evaluation device 34 of the embodiment of the apparatus 1' the evaluation device 82.The detection devices 41, 42 can be designed to evaluate route data for encounters with another automatically driving vehicle A 1, A 2, which are transmitted by the central server 30 or are exchanged among one another by the vehicles A 1, A 2. In particular, the server 30 can be configured to adapt the routes of the automatically driving vehicles A 1, A 2 by means of a route planning device 38 in such a way that they meet one another at suitable locations and under suitable conditions in order to check the degradation / aging of their environment detection systems, as described here.Route planning can also be adapted in the case of vehicles operated in an assisted and non-assisted manner, provided that the route planning device 38 of the central server 30 is used or at least included for route planning.In FIG. 2, time stamps TR 1 and TR 2 are correspondingly plotted on two time scales 101, 102 synchronized in time. The corresponding time scales can derive the automatically driving vehicles A 1, A 2 either on the basis of a communication with the central server 30 or on the basis of signals of a satellite navigation system, not shown, to name just a few examples. How the vehicles can generate or derive a time scale synchronized with one another. Alternatively, for example, signals of a GMS radio network or the like could be used. In Fig. 2, time stamps TR1 and TR2 coincide at the same time. This is the optimal case in which both vehicles detect each other simultaneously. In this case, the two surroundings detection systems 41 and 42 have the same detection range. A derived time difference ΔTR1=TR2-TR1 is equal to zero, i.e. ΔTR1=0, as is the time difference ΔTR2=TR2-TR1, i.e. ΔTR2=0. There is therefore no degradation. In this case, it is assumed that vehicles do not both experience a degradation of their environment detection system at the same time unrecognized.In FIG. 2, two further alternative detection times are additionally entered in dotted lines TR1' and dashed lines TR1", which pictorially represent other encounter situations or degradations of the environment detection systems 41, 42 relative to one another. If the first automatic driving vehicle A1 detects the other automatic driving vehicle A2 earlier in time than the other automatic driving vehicle A2 which detects one automatic driving vehicle A1, the difference ΔTR1'=TR2-TR1'>0. There is therefore no degradation of the environment detection sensor system 41 of the one automatically driving vehicle A 1. In the other situation, the determined time difference ΔTR 1" =TR 2-TR 1"<0. The time difference is thus negative. In this case, there may be degradation of the environment detection system 41 of the one automatically driving vehicle A 1. It can now be checked whether the resulting value ΔTR1" is smaller than a threshold value δ S( v relativ). In the sign convention chosen here, this is equivalent to an amount of the time difference |ΔTR1"| being greater than the amount of the threshold value |δ s( v)|, |ΔTR1"|>| δ S( v relativ)|. The threshold value δ S( v) is a speed-dependent threshold value for indicating impermissible degradation of a surroundings detection sensor, which is dependent on a relative speed v realtiv of the automatically driving vehicles A 1 and A 2.FIG. 3 graphically shows a threshold value function 301, δ S( v relativ) as a function of the relative speed of the approaching automatically driving vehicles A 1 and A 2.In the example shown above, it has been assumed that the two automatic driving vehicles A 1 and A 2 move in the opposite direction in terms of amount at the same speed v 0 i.e. v 1=-v 2, such that the relative speed Δv corresponds to the amount of 2 v 0 Δv=2 v 0. Δv is the relative speed v relativ. An exemplary curve is plotted here, which is intended to explain the relationships only qualitatively. The higher the relative speed v relativ= Δv, the lower the accepted negative time difference δ(v relativ), which is acceptable for a surroundings detection system. If the time difference has a larger negative value, the corresponding environment detection system is to be characterized as degraded, i.e. if ΔTR1"<δ(v relativ). It is understood that this statement depends on the chosen convention of determining the time difference. Here, the time difference ΔTR1" is always calculated as the time stamp TR2 of the other automatic driving vehicle A2 minus the time stamp TR1" of the one automatic driving vehicle A1, and the possible degradation of the one automatic driving vehicle A1 is considered based on this time difference ΔTR1". The accepted time difference δ(v relativ) is then negative or zero for the environment detection system 41 of the one automatically driving vehicle A 1.Here, degradation is determined only for the one automatically driving vehicle A 1. It is understood that, on the basis of the time difference ΔTR1 determined for the one automatically driving vehicle A 1, if this is positive, it follows that the time difference ΔTR2, which is identical in terms of amount, is negative. In the case of identical types of environment detection systems 41, 42 of the two automatically driving vehicles A 1 and A 2, a degradation of one of the two environment detection systems 41, 42 can thus be determined if an amount of the time difference |ΔTR 1| is greater than the amount of the permissible threshold value |δ(v relativ)| i.e. |ΔTR 1|>|δ(v relativ)|, where |ΔTR 1|=|ΔTR 2|. Which of the two environment detection systems 41, 42 is degraded can then be established on the basis of the sign of any of the two time differences ΔTR 1 and ΔTR 2.Here, only a very simple case is shown. An operator of a fleet of vehicles may also determine the thresholds for degradation based on swarm data. Environment sensors exhibiting a significant deviation are thus easy to identify. Accordingly, an exchange of the environment detection system can be initiated or a maximum speed at which the automatically driving vehicle can be operated can be adapted in order to indicate only exemplary consequences and further processings of the degradation values. Furthermore, systematic aging processes of environment detection systems can be detected at an early stage on the basis of the swarm data. The swarm data can thus be used for further and new developments. In general, time stamps for a plurality of environment detection systems of each automatically driving vehicle are detected in the case of a meeting and evaluated against one another. This is usually done in pairs by comparing the time stamps of similar environment detection systems with one another.In addition, in the illustrated embodiment, the one automatic driving vehicle A 1 and the other automatic driving vehicle A 2 still detect an external object O 1 located adjacent to the road section 10. On the basis of the information acquired in this case, it is possible to relate the environment acquisition of objects to the environment sensor acquisition of the approaching automatically driving vehicles and to validate this environment acquisition.The invention is described in connection with automatically driving vehicles of a fleet of vehicles. The description applies in the same way to vehicles which are not automated or not fully automated, but are operated only assisted or not assisted.It is understood by those skilled in the art that only a greatly simplified exemplary embodiment is described here. The individual features listed above may be utilized in various combinations to practice the invention.List of reference characters1, 1', 1" Device for determining degradation / aging of a surroundings detection system 10 Road 11 Road body 12 Lane 21 Communication system 22 Communication system 30 Central server 31 Flash 32 Flash 33 Time stamp generation device 34 Evaluation device 35 Differentiation device 36 Degradation value determination unit 37 Output device 38 Route planning device 41 Surroundings detection system 42 Surroundings detection system 51 Radar beams 52 Radar beams 61 Detection device 62 Detection device 71 Time stamp generation device 72 Time stamp generation device 81 Evaluation device 82 Evaluation device 83 Difference formation device 84 Difference formation device 85 Degradation value determination unit 86 Degradation value determination unit 87 Output device 88 Output device A1 Automatic driving vehicle A2 Other automatic driving vehicle 101 Time beam 102 Time beam TR1, TR1', tr1" time stamp of the time at which A1 A2 first acquires TR2, time stamp of the time at which A2 A1 first acquires t time v1 speed of A1 v2 speed of A2 v 0 target speed Δv relative speed O1 object 301, δ S( Δv) degradation threshold function

Claims

Method for determining the ageing and / or degradation of environment detection systems (41, 42) of automatically driving vehicles (A1, A2) of a fleet of vehicles, wherein each of the vehicles (A1, A2) comprises at least one environment detection system (41, 42) in order to detect and / or locate objects in the environment of the vehicle (A1, A2) therewith, comprising the steps: mutually detecting two automatically driving vehicles (A1, A2) in the event of an encounter, wherein each of the automatically driving vehicles (A1, A2) generates a time stamp (TR1, TR1', TR1", TR2) which indicates the point in time on a common time scale (101, 102) at which it is the other automatically driving vehicle (A1, A2) with its own at least one environment detection system (41, 42), wherein each time stamp (TR1, TR1', TR1", TR2) is assigned detection information, wherein the detection information comprises at least sensor characterization data of the at least one environment detection system (41, 42) used for detecting the time stamps (TR1, TR1', TR1", TR2); determining at least one time difference (ΔTR1, ΔTR1', ΔTR1", ΔTR2) on the basis of the recorded time stamps (TR1, TR1', TR1", TR2), wherein the at least one time difference (ΔTR1, ΔTR1', ΔTR1", ΔTR2) is assigned difference information items, which comprise at least the sensor characterization data of the environment detection systems (41, 42) used for detecting the time stamps (TR1, TR1', TR1", TR2), on the basis of the detection information items of the time stamps (TR1, TR1', TR1", TR2), determining degradation values for the individual environment detection systems on the basis of the at least one time difference (ΔTR1, ΔTR1', ΔTR1", ΔTR2); outputting and / or providing the degradation values.Method according to Claim 1, characterized in that the time stamps (TR1, TR1', TR1", TR2) and detection information are exchanged between the automatically driving vehicles (A1, A2) by means of Car2Car communication.Method according to Claim 1 or 2, characterized in that the time stamps (TR1, TR1', TR1", TR2) and detection information are transmitted to at least one central server (30), and the time differences (ΔTR1, ΔTR1', ΔTR1", ΔTR2) and degradation values are determined in the central server (30).Method according to one of the preceding claims, characterized in that an imminent encounter is detected on the basis of route data.Method according to one of the preceding claims, characterized in that the route data of at least one of the vehicles (A1, A2) involved in a encounter is adapted in order to bring about a encounter.Method according to one of the preceding claims, characterized in that the route data of at least one vehicle (A1, A2) are adapted in such a way that a meeting with another of the vehicles (A1, A2) takes place in such a way that it comprises a similar age and / or similar environment sensors (41, 42).Method according to one of the preceding claims, characterized in that at least one of the vehicles (A1, A2) determines a time stamp (TR1, TR1', TR1", TR2) for a plurality of its environment detection systems (41, 42), said time stamp indicating when the corresponding environment detection system (41, 42) has detected the other automatically driving vehicle (A1, A2).Method according to one of the preceding claims, characterized in that the vehicles (A1, A2) buffer-store at least sensor measurement data of the at least one environment detection system (41, 42) in a short-term memory in order to determine a time stamp (TR1, TR1', TR1", TR2) for detecting the other automatically driving vehicle (A1, A2) on the basis of the stored sensor measurement data if the automatically driving vehicle (A1, A2) does not recognize the meeting until the at least one environment detection system (41, 42) has already detected the other automatically driving vehicle (A1, A2).Method according to one of the preceding claims, characterized in that the detection information comprises environmental information which characterizes the environment in the encounter environment.Method according to one of the preceding claims, characterized in that the detection information is added to detected encounter information items which comprise in particular a vehicle speed, a vehicle acceleration, a determined vehicle distance, a signal strength of the sensor signal, a signal quality of the sensor signal (e.g. SNR), an illumination situation, an orientation in space, lane information items, weather conditions, a geoposition, temperature, time of day, traffic volume etc.Method according to one of the preceding claims, characterized in that object detection information is added to the detection information, said object detection information comprising details about a detection of at least one object (O1) in the meeting environment with the at least one environment detection system (41, 42) or another environment detection system (41, 42) of the automatically driving vehicle (A1, A2).Device for determining the ageing and / or degradation of at least one environment detection system (41, 42) of at least one vehicle (A1, A2) of a fleet of vehicles, wherein each vehicle (A1, A2) of the fleet of vehicles comprises at least one environment detection system (41, 42) in order to detect and / or locate objects in the environment of the vehicle (A1, A2) therewith, and a detection device which is designed to detect a time stamp which indicates the time on a common time scale (101, 102) at which the respective vehicle (A1, A2) has detected another of the automatically driving vehicles (A1, A2) for the first time with its own at least one environment detection system (41, 42), wherein the detection devices are designed to assign detection information to each time stamp (TR1, TR1', TR1", TR2), wherein the detection information comprises at least sensor characterization data of the at least one environment detection system (41, 42) used for detecting the time stamp (TR1, TR1', TR1", TR2); wherein the apparatus comprises at least one of the detection device (61, 62) of the at least one vehicle and an evaluation device (81, 82, 34) which is designed to detect time stamps and associated detection information of the detection devices (61, 62) of the at least one vehicle (A1, A2) and of at least one other of the vehicles (A1, A2) of the vehicle fleet, wherein the evaluation device (81, 82, 34) comprises a difference formation device which is designed to determine at least one time difference (ΔTR1, ΔTR1', ΔTR1", ΔTR2) on the basis of the detected time stamps (TR1, TR1', TR1", TR2), wherein difference information is assigned to the at least one time difference (ΔTR1, ΔTR1', ΔTR1", ΔTR2) in each case on the basis of the detection information of the time stamps (TR1, TR1', TR1", TR2), said difference information comprising at least the sensor characterization data of the environment detection systems (41, 42) used for detecting the time stamps (TR1, TR1', TR1", TR2), and comprising a degradation value determination unit for determining a degradation value on the basis of the determined at least one time difference and an output device (87, 88, 37) for outputting the degradation value.Device according to claim 12, characterised in that the evaluation device (81, 82, 34) is arranged in the at least one vehicle (A1, A2). in which the one detection device (61, 62) of the at least one vehicle (A1, A2) is also arranged.Device according to claim 12, characterised in that the evaluation device (81, 82, 34) is formed in a central server of the vehicle fleet.Device according to one of Claims 12 to 14, characterized in that the device additionally comprises the detection device (61, 62) of the at least one other vehicle (A1, A2).Detection device (61, 62) for a device for determining the ageing and / or degradation of at least one environment detection system (41, 42) of at least one vehicle (A1, A2) of a vehicle fleet, wherein the detection device (61, 62) either comprises a time stamp generation device (71, 72, 33) for providing time stamps on a time scale common to the vehicles of the vehicle fleet or can be coupled to such a time stamp generation device (71, 72, 33) and can additionally be coupled to at least one environment detection system (41, 42) of a vehicle of the vehicle fleet, wherein the at least one environment detection system (41, 42) is designed to detect and / or locate objects in the environment of the one vehicle (A1, A2), wherein the detection device (61, 62) is designed to detect a time stamp (TR1, TR1', TR1", TR2), which indicates the time on the common timescale (101, 102) at which another of the vehicles (A1, A2) is first detected with the coupled at least one environment detection system (41, 42) of the one vehicle (A1, A2) during a encounter, wherein the detection devices (61, 62) are designed to assign detection information to each time stamp (TR1, TR1', TR1", TR2), wherein the detection information comprises at least sensor characterization data of the at least one environment detection system (41, 42) used for detecting the time stamp (TR1, TR1', TR1", TR2), wherein the detection device (61, 62) is furthermore designed to transmit the detected time stamps and assigned detection information to an evaluation device (81, 82, 34).

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