Control unit for a motor vehicle and method of a server for creating map data

Abstract

The invention relates to a control unit (4) for a motor vehicle (2), a method of a server for creating map data and a motor vehicle (2). It is intended that speed bump data is determined from a plurality of data sets containing information on possible positions of speed bumps (6) and is transmitted to a plurality of motor vehicles (2) via a server (8). Each individual motor vehicle (2) is then no longer solely dependent on the on-board sensors for detecting speed bumps (6), thus achieving increased safety and comfort when crossing a speed bump (6) with a semi-autonomous or autonomously driving motor vehicle (2).

Description

The invention relates to a control device for a motor vehicle, to a method of a server for creating map data, and to a motor vehicle.In locations in road traffic, where speed crossings by motor vehicles are frequently to be expected, or where a particularly low speed of the traffic is necessary, for example in the area of a bus stop or school, so-called speed bumps or braking thresholds are often used for traffic deceleration. Such a braking threshold generally consists of an elevation projecting upward from the road surface, which elevation can be easily traveled over by motor vehicles at a slow pace, for example at the pace of the step, but which at a high crossing pace leads to vibrations that are unpleasant for the vehicle occupants and / or possibly also to damage to the motor vehicle. When using an (adaptive) cruise control, in other words, therefore, in a partially autonomous or autonomously driving motor vehicle, this motor vehicle would drive over the braking thresholds in an un-braked manner, which would thereby lead to damage to tires and / or the motor vehicle, but would at least be unpleasant for the occupants. It is therefore known to employ systems in semi-autonomous or autonomous driving motor vehicles that detect and react to such braking thresholds by reducing the crossing speed to an appropriate value. The known systems usually use ad hoc detection by camera, radar, lidar or similar sensory systems.A method is known from DE 10 2014 007 579 A1, in which a braking threshold attached to a roadway is detected by an evaluation device of a motor vehicle on the basis of sensor data provided, and a speed limit for the motor vehicle is determined as a function of the detection of the braking threshold.US 2017 / 0 106 855 A1 describes a method for limiting a current operating speed of a vehicle. A position of the vehicle relative to an abrupt road change in front of the vehicle and a current operation speed are determined, and information on an abrupt lane change profile is acquired. Based on the determined position and the current operating speed, a braking torque is set to reduce the current operating speed.WO 2021 / 243 576 A1 discloses a detection device for detecting speed thresholds or impact holes on a road. The sensing device comprises a telemetry sensing system configured to sense a plurality of position vectors by telemetry sensing of a road surface, each position vector extending from a common origin to a respective point on the road surface, each position vector having a length and a direction. The detection device further includes a processing circuit configured to recognize an exception from the road plane by evaluating the lengths of the position vectors. In this way, an improved apparatus for detecting road irregularities, such as speed bumps or potholes, on a road is provided.From EP 3 644 294 A1 it is known to determine on the basis of a driving state of a vehicle whether or not a vehicle has passed a ground threshold. Position information of the ground threshold and vehicle speed information when crossing the ground threshold are determined and stored as ground threshold information from travel data of the vehicle.DE 10 2022 107 893 A1 describes an adaptive vehicle system which responds to changing terrain in order to avoid damage to vehicles with low road clearance. The system uses road deviation data to adjust the ride height of the vehicle and / or warn the driver. This data may be collected by onboard sensors and / or other vehicles through crowdsourced and transmitted to a cloud database.DE 10 2014 208 318 A1 discloses a regulation of the dampers of an adaptive chassis when passing over a braking threshold. The method increases the damping force of the relevant damper by at least 1.5 times the normal setting when the vehicle reaches the braking threshold, and lowers it again when the braking threshold is exitedDE 11 2022 001 520 T5 describes an exterior recognition system that recognizes three-dimensional shapes of road surfaces in order to improve autonomous driving. The system utilizes a combination of vehicle cameras, vehicle-to-vehicle communication, and an external server with a database of road surface information. Information providing vehicles transmit position data of road surface structures to the server. The server analyzes this data to generate and map driver driving information.DE 10 2017 222 017 A1 describes a method and a system for determining a ground profile in front of a vehicle. The system uses sensor data (e.g., from LIDAR, radar, cameras) to detect vertical motion of a preceding vehicle relative to the measuring vehicle. This data is used to calculate the ground profile, filtering out the own motion of the measuring vehicle. The ground profiles may be stored on a server and made accessible to other vehicles.DE 10 2019 217 006 A1 describes a method, a device and a computer program product for load-minimum trajectory planning for vehicles. The aim is to minimize the burden on vehicles and occupants to extend the life of the vehicle and reduce the risk of travel. The system plans the trajectory based on already traveled trajectories and known load hot spots. Lateral displacements of the trajectory and / or speed reductions in the region of the load hot spots are checked.DE 10 2017 208 239 A1 describes a method for determining the shape property of an individual obstacle, such as a striking hole or a braking threshold, which is traveled over by a vehicle. It uses a road observer signal, for example from suspension travel sensors, which is first filtered to determine the beginning and end of the obstacle. Subsequently, a more weakly filtered or unfiltered signal is used to extract the shape property from the region between the beginning and the end.The solutions according to the prior art are often not sufficient, since the braking thresholds are not always detected with sufficient accuracy. In addition, there are also attacks of braking thresholds which consist merely of a coloring on the roadway suggestive of a braking threshold and do not require braking of the motor vehicle. Automatic braking of a partially autonomous or autonomously driving motor vehicle may in such a case lead to confusion in the vehicle occupants and / or in the following traffic, which also increases the risk of a rear-end collision.The object of the invention is to specify a possibility of improving and making more safe the behavior of a semi-autonomous or autonomously driving motor vehicle with respect to driving over braking thresholds.The object is achieved by a control device for a motor vehicle, wherein the control device is configured to determine a position of a braking threshold traveled by the motor vehicle on the basis of first sensor data provided by the motor vehicle, to determine at least one geometric property of the braking threshold on the basis of the first sensor data and / or on the basis of second sensor data provided by the motor vehicle, and to transmit the position and the at least one geometric property of the braking threshold to a server, wherein the first sensor data and / or the second sensor data and / or third sensor data relate to the driving behavior of a vehicle driving ahead in the form of a speed profile and / or a braking profile and / or an acceleration profile of the vehicle driving ahead.The object is furthermore achieved by a motor vehicle, having at least one first sensor set up to acquire first sensor data relating to a position of a braking threshold; at least one second sensor set up to acquire second sensor data relating to at least one geometric property of a braking threshold; and a control device according to the invention of the type described above.The object is likewise achieved by a method of a server for creating map data, the method having the steps:receiving a plurality of data sets from a plurality of motor vehicles,wherein each data record has information with respect to a position and at least one geometric property of at least one braking threshold traveled over by the respective motor vehicle,determining braking threshold data, comprising information relating to the position and at least one geometric property of at least one braking threshold, if corresponding information relating to the at least one braking threshold is present in a plurality of data sets,transmitting the braking threshold data to a plurality of vehicles,wherein additional braking threshold data are obtained from the data sets on the basis of an analysis of speed data and / or acceleration data of the motor vehicle from which the respective data set originates and / or on the basis of an analysis of speed data and / or acceleration data of a vehicle driving ahead of the motor vehicle from which the respective data set originates, wherein typical speed profiles for brake thresholds crossed are stored and are used as a criterion for identifying a braking threshold.According to the invention, the first sensor data is used to determine the position of the braking threshold and the second sensor data is used to determine at least one geometric property of the braking threshold. It is possible here for the first sensor data and the second sensor data to be provided by a common first sensor. For example, data relating to the position and also relating to the geometry of the braking threshold can be extracted from image data supplied by a camera. Likewise, a GPS sensor can be used as a further sensor, for example as a second sensor, which allows a position determination of the motor vehicle and thus also allows an absolute position of the braking threshold to be determined. It is also possible for the second sensor to monitor a state of the chassis of the motor vehicle, as will be described in detail further below. It is also possible to use more than two sensors, for example three, four or even more individual sensors, in order to determine the position and geometric properties of the braking threshold.In a preferred embodiment of the invention, it is provided that the control device is further configured to assign the braking threshold to a braking threshold category from a plurality of predefined braking threshold categories on the basis of the at least one geometric property. Such brake threshold categories can relate, for example, to the dimensions of the brake thresholds, in particular a height, a width and / or a length of the brake thresholds. Each braking threshold category can then be assigned value ranges for the height, the width and / or the length of the braking thresholds. It is also possible to provide different braking threshold categories for differently steep flank sections of the braking thresholds. In other words, each braking threshold category can be assigned a value range for an angle which a surface of the braking threshold to be traveled on forms with the horizontal. In this case, for example, an angle of approach can be defined as the angle formed with the horizontal of the surface of the braking threshold in the end region of the braking threshold facing an approaching motor vehicle, and an angle of approach can be defined as the angle formed with the horizontal of the surface of the braking threshold in the end region of the braking threshold facing away from an approaching motor vehicle. Value ranges can be assigned to the braking threshold categories both for the entry angle and for the exit angle. Special categories for specific design variants of braking thresholds can also be defined, for example for the so-called "coussins berlinois" widely used in France. Such "gussins berlinois" are distinguished by a relatively small width which does not completely fill the width of the roadway or of the lane, and by flanks which slope flat to the right and left.In a further preferred embodiment of the invention, it is provided that the second sensor data relate to at least one chassis state of the motor vehicle detected during the passing of the braking threshold. Information about the braking threshold exceeding the pure geometry of the braking threshold can thus be obtained. For example, brake sleepers which are made of different materials and / or have different surface structures can exert different effects on a motor vehicle crossing the brake sleeper with the same geometry. If the chassis state is detected, a description and / or categorization of the braking threshold can thus take place with increased detail density and / or precision. The chassis state can describe, for example, a temporal profile of a state of compression of a wheel of the motor vehicle, of one or more axles of the motor vehicle or of each individual wheel of the motor vehicle. In this case, in particular a compression speed and / or a maximum compression depth can be determined. The determined data relate to the chassis state and can be stored together with the speed of the motor vehicle.In a further preferred embodiment of the invention, it is provided that the first sensor data and / or the second sensor data and / or third sensor data relate to the driving behavior of a vehicle driving ahead. If a driving behavior of a vehicle driving ahead is detected, which is typical of the driving behavior of a vehicle crossing a braking threshold, this can be evaluated as an indicator of the presence of a braking threshold. In particular, a speed profile and / or a braking or acceleration profile of the vehicle driving in front can be analyzed and compared with a predefined speed profile or braking profile and / or a typical acceleration profile that is typical of a vehicle crossing a braking threshold.In a further preferred embodiment of the invention, it is provided that the control device is configured to determine the imminent driving over of a braking threshold on the basis of information about the position of the braking threshold and to adapt a chassis setting and / or a longitudinal dynamics control of the motor vehicle on the basis of the at least one geometric property. The chassis setting can relate, for example, to a damper hardness or another chassis tuning. The longitudinal dynamics control, in particular an adaptive cruise control (ACC=adaptive cruise control), of the motor vehicle can be adapted in such a way that the crossing of the braking threshold is carried out as quickly as possible but nevertheless as comfortably as possible. This allows increased comfort for the occupants of the motor vehicle and a driving behavior that approximates the driving behavior of a motor vehicle guided by a human driver to be achieved. The speed at which the crossing is to take place by means of longitudinal dynamics control is preferably dependent on the geometric properties of the braking thresholds. For example, at a higher braking threshold and / or at a steeper rising front and / or rear edge of the braking threshold, a lower speed can be selected for crossing the braking threshold than at a lower braking threshold and / or at a flatter rising front and / or rear edge of the braking threshold.In a further preferred embodiment of the invention, it is provided that the control device is configured to receive from a central computer or server braking threshold data relating to braking thresholds present in a surrounding area of the motor vehicle and to store the braking threshold data in a memory of the motor vehicle, wherein the braking threshold data for the braking thresholds comprise information relating to the position and at least one geometric property of the braking threshold. The positions and the geometric properties of a plurality of brake thresholds can thus be stored in the vehicle. It is also possible to store data on braking thresholds determined by the motor vehicle itself. These data can then be transmitted collectively, for example, to a server. Continuous maintenance of a communication connection is then not necessary. For example, the data can be collected until a communication connection is possible.In a further preferred embodiment of the invention, it is provided that the control device is further configured to use sensor data provided by the motor vehicle in order to check the braking threshold data received from the central computer. The known methods of ad hoc determination of the positions of brake thresholds by the respective motor vehicle can thus be combined with the swarm data-based method of retrieving brake threshold positions from a memory. For example, it can be provided that-if it is to be expected on the basis of the present map data that a braking threshold is briefly crossed-the sensor system of the motor vehicle is used to check whether the motor vehicle actually approaches a braking threshold and then, if appropriate, to ascertain the exact position and geometry of the braking threshold.In a further preferred embodiment of the invention, it is provided that the control device is further configured to display information determined from the braking threshold data in a map view and / or in a head-up display. Positions of these braking thresholds can be displayed in the map view and / or in the head-up display. Such a visual emphasis of the braking thresholds can be effected in particular analogously to contact in the AR HUD (augmented reality head-up display). Depending on the "degree of hardness" of the braking threshold or generally depending on the braking threshold category, a graphic, in particular a colored, emphasis can be provided here. The color emphasis can be based on the recommended driving speed. For example, a braking threshold may be marked green with a faster recommended override speed, while a braking threshold may be marked red with a slower recommended override speed. Alternatively or additionally, a corresponding marking can be made in the environment model or on an infoscreen. It is also possible to output an acoustic warning when the motor vehicle approaches a braking threshold. The outputting of the warning and / or the visual highlighting of the braking threshold can be coupled to the condition that the motor vehicle is completely controlled by a user, in particular that no longitudinal dynamics control or no distance template is active. It can furthermore be provided to output an acoustic warning if the current speed during the approach to a braking threshold is above a speed recommended for the braking threshold lying in front of the vehicle by a predetermined factor.The method according to the invention provides that braking threshold data are determined if corresponding information relating to the at least one braking threshold is present in a plurality of data sets which were transmitted in particular by a plurality of vehicles. This is to be understood in particular as meaning that information is present in a plurality of data sets which corresponds with respect to a candidate position of a braking threshold and / or with respect to the geometric properties of a possible braking threshold. If there are a sufficient number of data sets with matching information, it can be assumed that a braking threshold is actually present at the position. It is possible to carry out an examination of the candidate position on the basis of all data sets which contain information about this position. If, for example, a number of data sets exceeding a threshold value is present which does not contain a braking threshold at the position in question, it can be decided that it is not possible to infer the presence of a braking threshold with sufficient certainty at this position.The braking threshold data may be transmitted from the server to a motor vehicle together with map data or separately from map data. In other words, the braking threshold data can be sent as an update to map data already present in the motor vehicle or can be linked to the map data only in the vehicle. Alternatively, the braking threshold data can be linked to the map data on the server and sent together to the motor vehicle. It is likewise conceivable to store ascertained braking threshold data locally on the respective motor vehicle and to use these exclusively for controlling this same motor vehicle. For example, an analysis of the braking threshold data can be carried out and a decision can be made as to whether the determined braking threshold data are sufficiently representative to be sent to the server. It is likewise possible to send the braking threshold data to the server, but to use the determined braking threshold data even by the motor vehicle which has determined the braking threshold data before said braking threshold data are processed by the server and sent back to the motor vehicle as prepared data.In a further preferred embodiment of the method according to the invention, it is provided that additional braking threshold data are obtained from the data sets on the basis of an analysis of speed data and / or of acceleration data of the motor vehicle from which the respective data set originates and / or on the basis of an analysis of speed data and / or of acceleration data of a vehicle preceding the motor vehicle from which the respective data set originates. In this way, it is made possible to plausibilize the braking threshold data received from the server. The received brake threshold data may have inaccuracies or may no longer be up-to-date. By combining with a determination of the position and / or the geometric properties of the braking threshold in real time, an increased reliability and an increased accuracy of the overall system can thus be achieved.In a further development of the invention, it is provided that route algorithms are stored in the control device and / or in a navigation device connected to the control device, which route algorithms provide routes with braking thresholds with a higher weight and in this way avoid them as far as possible during route planning. The transit time or the calculation of the arrival time can also be adjusted accordingly, because in a region with braking thresholds or between two braking thresholds it is necessary to drive more slowly.According to a further development of the control device according to the invention, the presence of a construction site, which can be detected, for example, by a camera, in the city inside can also be evaluated as an indication that provisional braking thresholds for cable feedthroughs over the road, for example, have to be expected with greater probability. No swarm data can be used for these temporary solutions-but here the method can "especially" with the knowledge of an existing construction site, i.e. with higher sensitivity, pay attention to speed bumps or intentionally reduce the setting speed. In other words, limit parameters which were set as a brake threshold crossing for the classification of a driving situation ahead can be adapted in such a situation, so that the system responds more sensitively to possible brake thresholds. The parameters mentioned can be adapted in such a way that a speed profile suitable for crossing a braking threshold is already used when a braking threshold has been detected with relatively low probability. In other words, the system may choose a more de-efficient, more conservative driving style, for example, when it has been detected that the motor vehicle is located in the area of a construction site.Just like a recognized construction site, recognized traffic signs or markings on the roadway that announce a braking threshold can also be included in the method. Such a position identified by a corresponding traffic sign or a corresponding marking can be analyzed on the server in the swarm data specifically with regard to the driving behavior of the motor vehicles passing through the position.It is conceivable to realize the described features in different combinations. For example, it is conceivable to provide a marking in the HUD display without simultaneously acquiring, storing or using geometric data of the braking threshold. In particular, it is conceivable to use only one of the described methods for detecting a braking threshold. For example, a purely server-based model would also be conceivable, in which the plurality of motor vehicles each deliver pure travel data without assessing whether a braking threshold has been exceeded. An analysis could then be carried out on the server on the basis of the speed profiles contained in the travel data and / or on the basis of the acceleration profiles contained in the travel data. If the number of data sets is large enough, sufficiently accurate braking threshold data could also be obtained in this way.Further preferred embodiments of the invention result from the other features mentioned in the dependent claims.The various embodiments of the invention mentioned in this application can be combined with one another with advantage unless stated otherwise in the individual case.The invention is explained below in exemplary embodiments with reference to the associated drawings. The following are shown: FIG. 1 shows a first schematic illustration of a motor vehicle having a control device according to the invention, FIG. 2 shows a second schematic illustration of a motor vehicle having a control device according to the invention, FIG. 3 shows a flow diagram of an exemplary embodiment of a method according to the invention, FIG. 4 shows a view through a windshield of a motor vehicle with a control device according to the invention during travel, and FIG. 5 shows four diagrams, in which speed data of a plurality of motor vehicles each having passed the same route section in which a braking threshold is located, have been entered.FIG. 1 shows a schematic representation of a motor vehicle 2 with a control device 4 according to the invention. the motor vehicle 2 has wheels 16 and travels on a ground in the form of the roadway 14 in the direction of travel F. Located in front of the motor vehicle 2 in the direction of travel F is the braking threshold 6. The sensor data acquired by the first sensor 10 may be referred to as first sensor data, and the sensor data acquired by the second sensor 12 may be referred to as further sensor data. The first sensor 10 can be a camera, for example, and the second sensor 12 can be a further optical system, for example a radar system or a LIDAR system (abbreviation for "light detection and ranging" or "light imaging, detection and ranging"). The sensor data acquired by the first sensor 10 and the sensor data acquired by the second sensor 12 are output to the control device 4. The control device 4 interprets the sensor data, for example by means of image analysis software or other software, and uses the sensor data to determine information relating to the position of the braking threshold 6 and at least one geometric property of the braking threshold 6. A width of the braking threshold 6 or information regarding the configuration of a surface 28 of the braking threshold 6 can also be determined from the sensor data. The braking sleeper 6 shown as an example in FIG. 1 has an arcuate surface 28. In other words, a profile of the braking sleeper 6 shown in FIG. 1 has the shape of a lying D.The control device 4 can be connected to an on-board computer 24. It is also possible for the control device 4 and the onboard computer 24 to be formed by a common computing unit. The sensors 10 and 12 can accordingly be connected primarily to the control device 4 or to the onboard computer 24.The motor vehicle 2 furthermore has a communication module 18 which is connected to a server 8 and exchanges communication signals 20 with the latter. The control device 4 can thus transmit the data determined from the sensor data relating to the position and the at least one geometric property of the braking threshold 6 to the server 8. The transmission can take place directly after the detection of the braking threshold 6. Alternatively, it is also possible for the data to be transmitted after the end of the trip or at a predetermined interval. The communication module 18 may be configured to wirelessly communicate with the server 8.The server 8 can have a memory with a database in which map data are stored in particular. Position data and further properties, in particular geometric properties, of a multiplicity of braking thresholds 6 can be entered in the map data. The map data can be transmitted from the server 8 to the motor vehicle 2 or to the control unit 4 of the motor vehicle 2. Thus, data collected from a plurality of motor vehicles can be made generally accessible and used by different motor vehicles 2.In the exemplary embodiment shown, the motor vehicle 2 has third sensors 22, which each detect a compression state or a wheel base height of the wheels 16 of the motor vehicle 2. The third sensors 22 are likewise connected to the control unit 4. The control device 4 can record the time profile of the state of compression of the wheels 16 and can infer therefrom a profile of the underlying surface traversed, in particular a crossed braking threshold 6. In this way, further information regarding properties of the braking threshold 6, in particular regarding geometric properties of the braking threshold 6, can be obtained. This data can also be sent to the server 8, edited by the latter and distributed to further vehicles.FIG. 2 differs from FIG. 1 only in the shape of the braking threshold 6, which has a trapezoidal cross section in FIG. 2, so that the surface 28 of the braking threshold 6 can be roughly divided into a rising flank 30, a horizontal portion 32 and a falling flank 34. In this case, the braking threshold 6 can be characterized, for example, by the angle α formed by the rising edge 30 with the horizontal and by the angle β formed by the falling edge 34 with the horizontal.FIG. 3 shows a flow diagram of an exemplary embodiment of a method according to the invention. In a step S 10, a plurality of data records from a plurality of motor vehicles are received by a server, each data record having information regarding a position and at least one geometric property of at least one braking threshold traveled by the respective motor vehicle.In a step S 20, braking threshold data are determined by the server, wherein the braking threshold data comprise information regarding the position and at least one geometric property of at least one braking threshold if corresponding information regarding the at least one braking threshold is present in a plurality of data sets.In a step S 30, the braking threshold data is then transmitted to a plurality of vehicles.In an optional step S 40, additional braking threshold data can be obtained from the data sets on the basis of an analysis of speed data and / or acceleration data of the motor vehicle from which the respective data set originates and / or on the basis of an analysis of speed data and / or acceleration data of a vehicle preceding the motor vehicle from which the respective data set originates.FIG. 4 shows a view through a windshield of a motor vehicle 2 with a control device 4 according to the invention during travel. A roadway 14, a braking threshold 6 and a vehicle 36 driving ahead can be seen. In the exemplary embodiment on which FIG. 4 is based, the control unit 4 is set up to visually emphasize a braking threshold 6 lying ahead for the driver. In the exemplary embodiment shown, this is realized by the marking 26 in the form of triangles in a head-up display 38. The marking 26 is blended into the field of vision of the driver in such a way that it appears above the position of the braking threshold 6. The marking 26 can be configured depending on a type of the braking threshold 6 or on geometric properties of the braking threshold 6. In particular, the marker 26 may be color-coded. For example, the marking 26 can have different colors depending on a deceleration necessary for crossing the braking threshold 6 or a maximum speed recommended for crossing the braking threshold 6. Thus, a strong necessary deceleration and / or a low recommended maximum speed may be encoded by a red color of the marker 26, while a weak necessary deceleration and / or a relatively high recommended maximum speed may be encoded by a green color of the marker 26.FIG. 5 shows four diagrams in which speed data of a plurality of motor vehicles each having passed the same route section in which a braking threshold is located have been entered. In this case, a value representing an average speed of the plurality of motor vehicles was determined for different distances from the respective braking threshold and entered into the respective diagram. In addition, a compensation curve has been drawn in in each case, so that a typical speed profile for the respective braking threshold can be recognized. Such a speed profile can then be used to control a longitudinal dynamics control of a motor vehicle in the region of the associated braking threshold.It can be seen that different speed profiles have been selected by the respective drivers of the motor vehicles for different braking thresholds. Thus, for example, on average, the braking threshold described in the lower left quadrant was delayed less strongly, while in the braking threshold considered in the lower right quadrant, the speed was reduced by the driver further and with greater delay before returning to the initial speed after crossing the braking threshold.Corresponding speed profiles can likewise be stored and used as a criterion for identifying a braking threshold. If, for example, speed profiles of a specific course are increasingly detected in swarm data for a specific route section, this can be evaluated as an indication of the presence of a braking threshold. If necessary, the type of braking threshold or the braking threshold category can even be deduced from the ascertained speed profile. In other words, a driving behavior analysis, such as the braking behavior analysis, for example, from categories such as "slightly deceleration" versus "very high deceleration" may be used as an indicator to identify a braking threshold in the swarm data. As a further indicator, the behavior or braking behavior of the surrounding vehicles and / or vehicles located in front of the vehicle can be used as an analysis possibility. If such vehicles are deceleration heavily and / or suddenly, this is also an indicator of an increased probability of the presence of a braking threshold.List of reference characters2 Motor vehicle 4 control device 6 braking threshold 8 server 10 first sensor 12 second sensor 14 roadway 16 wheel 18 communication module 20 communication signals 22 third sensor 24 onboard computer 26 marking 28 surface 30 rising edge 32 horizontal portion 34 falling edge 36 vehicle 38 head-up display I length h height F direction of travel S 10 method step - receiving data sets S 20 method step - determining braking threshold data S 30 method step - transmitting braking threshold data S 40 method step - optionally; acquiring additional braking threshold data

Claims

Control device (4) for a motor vehicle (2), wherein the control device (4) is configured to determine a position of a braking threshold (6) traveled by the motor vehicle (2) on the basis of first sensor data provided by the motor vehicle (2), to determine at least one geometric property of the braking threshold (6) on the basis of the first sensor data and / or on the basis of second sensor data provided by the motor vehicle (2), and to transmit the position and the at least one geometric property of the braking threshold (6) to a server (8), wherein the first sensor data and / or the second sensor data and / or third sensor data relate to the driving behavior of a vehicle (36) driving ahead in the form of a speed profile and / or a braking profile and / or an acceleration profile of the vehicle (36) driving ahead.Control device (4) according to Claim 1, wherein the control device (4) is furthermore configured to assign the braking threshold (6) to a braking threshold category from a plurality of predefined braking threshold categories on the basis of the at least one geometric property.Control device (4) according to one of the preceding claims, wherein the second sensor data relate to at least one chassis state of the motor vehicle (2) detected during the passing of the braking threshold (6).Control device (4) according to one of the preceding claims, wherein the control device (4) is configured to determine the imminent driving over of a braking threshold (6) on the basis of information about the position of the braking threshold (6) and to adapt a chassis setting and / or a longitudinal dynamics control of the motor vehicle (2) on the basis of the at least one geometric property.Control device (4) according to one of the preceding claims, wherein the control device (4) is further configured to receive from the server (8) braking threshold data relating to at least one braking threshold (6) present in an environment of the motor vehicle (2) and to store the braking threshold data in a memory of the motor vehicle (2), wherein the braking threshold data for the braking thresholds comprise information relating to the position and at least one geometric property of the braking threshold (6).Control device (4) according to Claim 5, wherein the control device (4) is configured to use sensor data provided by the motor vehicle (2) in order to check the braking threshold data received from the central computer.Control device (4) according to either of Claims 5 and 6, wherein the control device (4) is furthermore configured to display information determined from the braking threshold data in a map view and / or in a head-up display (38).Motor vehicle (2), having at least one first sensor (10) set up to acquire first sensor data relating to a position of a braking threshold (6); at least one second sensor (12) set up to acquire second sensor data relating to at least one geometric property of a braking threshold (6); and a control unit (4) according to one of Claims 1 to 7.Method of a server (8) for creating map data, the method comprising the steps of: receiving (S10) a plurality of data sets from a plurality of motor vehicles (2), wherein each data set comprises information regarding a position and at least one geometric property of at least one braking threshold (6) traveled by the respective motor vehicle (2), determining (S20) braking threshold data comprising information regarding the position and at least one geometric property of at least one braking threshold (6) if corresponding information regarding the at least one braking threshold (6) is present in a plurality of data sets, transmitting (S30) the braking threshold data to a plurality of vehicles, wherein additional braking threshold data from the data sets on the basis of an analysis of speed data and / or acceleration data of the motor vehicle (2) from which the respective data set originates, and / or on the basis of an analysis of speed data and / or acceleration data of a vehicle (36) driving in front of the motor vehicle (2) from which the respective data record originates (S 40), wherein typical speed profiles for brake thresholds that have been traveled over are stored and used as a criterion for detecting a brake threshold.

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