A method for determining a road surface shape along a travel path of a vehicle, by a surface detection device of the vehicle, a computer program product

Abstract

The present invention relates to a method for determining a road surface shape (14) along a travel path (16) of a vehicle (10), by a surface detection device (12) of the vehicle, comprising the steps of: collecting motion data by a sensor system (18) of the vehicle; determining a trajectory of a certain point of the vehicle body, and roll and pitch angles of the vehicle, based on the motion data; determining, by the surface detection device for each wheel, a respective trajectory of a surface contact point (30) according to a tyre model of the respective wheel based on a respective trajectory of the wheel hub centre point which is in turn based on a respective trajectory of the wheel mounting point; and determining the road surface shape along the travel path of the vehicle based on the trajectories of the respective surface contact points.

Description

[0001] The present invention relates to the field of automobiles. More specifically, the present invention relates to a method for determining a road surface shape along a travel path of a vehicle by a surface detection device of the vehicle. Furthermore, the present invention relates to a corresponding computer program product, a corresponding non-transitory computer-readable storage medium, as well as to a corresponding surface detection device. BACKGROUND INFORMATION

[0002] Some areas in the world are mostly dry, but when it rains it can rain a lot. This is often the case in desert areas, where dry lake beds can suddenly turn into a big flash flood. On a smaller scale this also happens with creeks and even with road side ditches. Under such circumstances, pipes are sometimes not efficient or suitable to get rid of the amount of water likely to occur. As a solution the road surface itself is designed to be part of the drainage system by integrating the water runoff structure into the road. As a result, the road surface gets the shape of a dip. Dips also occur if the roadbed follows the earth surface, e.g. if the amount of grading needed for smoothing of the highs and lows exceeds the advantage of an even road bed. Variations in the road surface such as bumps or dips can also occur on rail road crossings, if the rail road level is higher or lower than the surrounding area.

[0003] Dips may be really deep with steep slopes, and sometimes they are difficult to recognize in advance regarding their depth, width and steepness. Sometimes dips are posted by road signs, sometimes they are not. Dips may not affect the speed limits so there may be no speed limit available requiring traffic to slow down. In consequence, a vehicle user may see scratch marks in the asphalt due to vehicles driving too fast and therefore hitting the pavement surface with the underbody of the vehicle. Therefore, variations in the road surface such as dips or other road surface events may create a risk of damage or even accident. It affects traditional vehicles as well as automated driving vehicles. SUMMARY OF THE INVENTION

[0004] It is an object of the present invention to provide a method, a corresponding computer program product, a corresponding non-transitory computer-readable storage medium, as well as a corresponding surface detection device, by which a detection and handling of road surface events like dips having a driving impact for vehicles is provided.

[0005] This object is solved by a method, a corresponding computer program product, a corresponding non-transitory computer-readable storage medium, as well as a corresponding surface detection device according to the independent claims. Advantageous embodiments are presented in the dependent claims.

[0006] One aspect of the present invention relates to a method for determining a road surface shape along a travel path of a vehicle, by a surface detection device of the vehicle. The method comprises a step of collecting motion data by a sensor system of the vehicle, the motion data describing a motion of the vehicle along the travel path. The method comprises a step of determining by the surface detection device a trajectory of a certain point of the vehicle body based on the motion data. The method comprises a step of determining, by the surface detection device, a roll angle and a pitch angle of the vehicle body based on the motion data. The method comprises a step of determining, by the surface detection device, for each wheel of the vehicle a respective trajectory of a respective wheel mounting point of the respective wheel. The method comprises a step of determining, by the surface detection device, for each wheel a respective trajectory of a respective wheel hub center point based on the respective trajectory of the respective wheel mounting point and travel data of a respective suspension spring provided by a respective suspension spring travel sensor device. The method comprises a step of determining, by the surface detection device, for each wheel a respective trajectory of a surface contact point according to a tire model of the respective wheel based on the respective trajectory of the wheel hub center point. The method comprises a step of determining the road surface shape along the travel path of the vehicle based on the trajectories of the respective surface contact points.

[0007] Therefore, the present invention provides a solution for determining a road surface shape along the travel path of the vehicle.

[0008] According to an embodiment, the method comprises the steps of examining, by the surface detection device, the road surface shape along the travel path for a presence of a predefined shape pattern, and upon detection of the predefined shape pattern, generating a shape event indicating the presence of the predefined shape pattern and a location of the predefined shape pattern along the travel path in an event database.

[0009] According to an embodiment, the method comprises the step of determining, by the surface detection device, a side slope of the road surface shape along the travel path. The method comprises the step of examining, by the surface detection device, the side slope along the travel path for a presence of a predefined side slope event. The method comprises the step of upon detection of the predefined side slope event, storing the side slope indicating the presence of the predefined side slope event and a location of the side slope event along the travel path in an event database.

[0010] According to an embodiment, the method comprises the steps of determining, by the surface detection device, an impact value of the event on the vehicle according to a predefined impact estimation method based on the motion data of the vehicle and adding the impact value to the event in the event database.

[0011] According to an embodiment, the method comprises the step of synchronizing, by the surface detection device, the events in the event database with a central event database of a server exterior to the vehicle.

[0012] According to an embodiment, the method comprises the steps of examining, by the surface detection device, the event database for a presence of the event along a planned travel path and / or an estimated travel path, and upon detection of the event, sending a predefined warning signal to an interface device of the vehicle to give an acoustic and / or visual output in the vehicle.

[0013] According to an embodiment, the method comprises the step of upon detection of the event, sending a predefined control signal to a control device of the vehicle to adapt a driving of the vehicle according to predefined adaption step according to the vehicle.

[0014] Another aspect of the present invention relates to a computer program product comprising program code means for performing a method according to the preceding aspect.

[0015] A still further aspect of the present invention relates to a non-transitory computer-readable storage medium comprising at least the computer program product according to the preceding aspect.

[0016] Another aspect of the present invention relates to surface detection device of the vehicle, wherein the surface detection device of the vehicle is configured for performing a method according to the preceding aspect. In particular, the method is performed by the surface detection device of the vehicle.

[0017] Advantageous embodiments of the method are to be regarded as advantageous embodiments of the computer program product, the non-transitory computer-readable storage medium, as well as the system. Therefore, the surface detection device of the vehicle comprises means for performing the method.

[0018] A computing unit / electronic computing device may, in particular, be understood as a data processing device, which comprises processing circuitry. The computing unit can therefore in particular process data to perform computing operations. This may also include operations to perform indexed accesses to a data structure, for example a look-up table, LUT.

[0019] In particular, the computing unit may include one or more computers, one or more microcontrollers, and / or one or more integrated circuits, for example, one or more application-specific integrated circuits, ASIC, one or more field-programmable gate arrays, FPGA, and / or one or more systems on a chip, SoC. The computing unit may also include one or more processors, for example one or more microprocessors, one or more central processing units, CPU, one or more graphics processing units, GPU, and / or one or more signal processors, in particular one or more digital signal processors, DSP. The computing unit may also include a physical or a virtual cluster of computers or other of said units.

[0020] In various embodiments, the computing unit includes one or more hardware and / or software interfaces and / or one or more memory units.

[0021] A memory unit may be implemented as a volatile data memory, for example a dynamic random access memory, DRAM, or a static random access memory, SRAM, or as a non-volatile data memory, for example a read-only memory, ROM, a programmable read-only memory, PROM, an erasable programmable read-only memory, EPROM, an electrically erasable programmable read-only memory, EEPROM, a flash memory or flash EEPROM, a ferroelectric random access memory, FRAM, a magnetoresistive random access memory, MRAM, or a phase-change random access memory, PCRAM.

[0022] Further advantages, features, and details of the present invention derive from the following description of preferred embodiments as well as from the drawings. The features and feature combinations previously mentioned in the description as well as the features and feature combinations mentioned in the following description of the figures and / or shown in the figures alone can be employed not only in the respectively indicated combination but also in any other combination or taken alone without leaving the scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The novel features and characteristic of the present disclosure are set forth in the appended claims. The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate exemplary embodiments and together with the description, serve to explain the disclosed principles. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the figures to reference like features and components. Some embodiments of system and / or methods in accordance with embodiments of the present subject matter are now described below, by way of example only, and with reference to the accompanying figures.

[0024] The drawings show in:

[0025] Fig. 1 a schematic illustration of a vehicle comprising a surface detection device; and

[0026] Fig. 2 a flow chart of a method for determining a road surface shape along a travel path of a vehicle, by a surface detection device of the vehicle.

[0027] In the figures the same elements or elements having the same function are indicated by the same reference signs. DETAILED DESCRIPTION

[0028] In the present document, the word "exemplary" is used herein to mean "serving as an example, instance, or illustration". Any embodiment or implementation of the present subject matter described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.

[0029] While the present disclosure is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawing and will be described in detail below. It should be understood, however, that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternatives falling within the scope of the disclosure.

[0030] The terms “comprises”, “comprising”, or any other variations thereof, are intended to cover a non-exclusive inclusion so that a setup, device or method that comprises a list of components or steps does not include only those components or steps but may include other components or steps not expressly listed or inherent to such setup or device or method. In other words, one or more elements in a system or apparatus preceded by “comprises” or “comprise” does not or do not, without more constraints, preclude the existence of other elements or additional elements in the system or method.

[0031] In the following detailed description of the embodiment of the present disclosure, reference is made to the accompanying drawing that forms part hereof, and in which is shown by way of illustration a specific embodiment in which the disclosure may be practiced. This embodiment is described in sufficient detail to enable those skilled in the art to practice the disclosure, and it is to be understood that other embodiments may be utilized and that changes may be made without departing from the scope of the present disclosure. The following description is, therefore, not to be taken in a limiting sense.

[0032] Fig. 1 shows in a schematic illustration a vehicle 10 comprising a surface detection device 12.

[0033] The vehicle 10 may comprise the surface detection device 12 to determine a road surface shape 14 along a travel path 16 of the vehicle 10. The vehicle 10 may comprise a sensor system 18 configured to provide motion data wherein the motion data may describe a motion of the vehicle 10 along the travel path 16. The surface detection device 12 may determine a trajectory of a certain point 20 of a vehicle 10 body based on the motion data. The motion data may comprise GPS data and / or data of an inertial sensor device of the vehicle 10. The certain point 20 may be a specific point in the center of the vehicle 10. The surface detection device 12 may be configured to determine a roll angle and the pitch angle of the vehicle 10 body based on the motion data. The surface detection device 12 may be configured to determine for each wheel of the vehicle 10 a respective trajectory of a respective wheel mounting point 22 of the respective wheel. The surface detection device 12 may be configured to determine for each wheel a respective trajectory of the respective wheel hub center point 24 based on the respective trajectory of the respective wheel mounting point 22 and travel data of the respective suspension spring 26 provided by a respective suspension spring travel sensor device 28. The surface detection device 12 may be configured to determine for each wheel the respective trajectory of the surface contact point 30 according to a tire model of the respective wheel based on the respective trajectory of the wheel hub center point 24. The surface detection device 12 may be configured to determine the road surface shape 14 along the travel path 16 of the vehicle 10 based on the trajectories of the respective surface contact points 30. The surface detection device 12 may be configured to examine the road surface shape 14 along the travel path 16 for a presence of a shape pattern 32, which may be predefined. Upon detection of the shape pattern 32, the surface detection device 12 may generate a shape event 34 indicating the presence of the shape pattern 32 and a location of the shape pattern 32 along the travel path 16 in an event database 38.

[0034] The surface detection device 12 may be configured to determine a side slope of the road surface shape 14 along the travel path 16 and to examine the side slope along the travel path 16 for a presence of a side slope event 36, which may be predefined. The side slope event 36 may be related to a threshold angle of the side slope. The surface detection device 12 may be configured to upon detection of the side slope event 36 indicating the presence of a property of the side slop event 36 of the road surface shape 14 such as the location of the side slope along the travel path 16 in the event database 38.

[0035] The surface detection device 12 may be configured to determine an impact value 40 of the event on the vehicle 10 based on the motion data of the vehicle 10 and the respective event 34, 36 in the event database 38.

[0036] The surface detection device 12 may be configured to synchronize the events 34, 36 in the event database 38 with a central event database 42 located on a server 44 exterior to the vehicle 10.

[0037] The surface detection device 12 may be configured to examine the event database 38 and / or the event databased 42 for a presence of the events 34, 36 along a planned travel path 16 and / or an estimated travel path 16 and upon detection of the events 34, 36 along the planned travel path 16 and / or the estimated travel path 16, to send a predefined warning signal 46 to an interface device 48 of the vehicle 10 to give an acoustic and / or visual output in the vehicle 10 and / or to send a control signal, which may be predefined, to a control device 50 of the vehicle 10 to adapt a driving of the vehicle 10 according to predefined adaption step. The adaption of the driving may comprise a reduction of the speed of the vehicle 10.

[0038] The present disclosure may include a system, consisting of the means available in a vehicle 10 and / or a fleet of vehicles 10 and / or in a cloud environment to detect the shape such as a shape pattern 32 of the road surface of the travel path 16 by collecting data from vehicle 10 or a fleet of vehicle 10. The data may be collected from a sensor system 18 that may include data from GNSS signals (elevation, position, distance), accelerometers and gyroscopes (3 axis, on vehicle 10 body, e.g. out of ESP vehicle 10 stability program or out of Navigation system), speed sensors, steering sensors, and / or other comparable sensors to determine the 3D trajectory of the vehicle 10 or at least the trajectory in driving direction and in vertical direction for a certain point 20 of the vehicle 10 body. The system may use sensor data fusion to determine trajectory and / or other events.

[0039] Fig. 2 shows in a flow chart a method for determining a road surface shape 14 along a travel path 16 of a vehicle 10, by a surface detection device 12 of the vehicle 10.

[0040] The method may comprise a step of applying a sensor data fusion of the above sensors to obtain the roll angle and the pitch angle of the vehicle 10 body then applying a geometry model of the vehicle 10 with the certain point 20 of the vehicle 10 body above and the location of the four wheels of the vehicle 10 relative to the certain point 20 and the roll angle and pitch angle of the body to the overall vehicle 10 trajectory to determine the trajectory of each of the wheels mounting point 22 on the body by taking into account the suspension spring travel sensor device 28 to determine the trajectory of each wheels hub center point 24 by then applying a tire model to determine back from the trajectory of the wheel hub center point 24 to the road surface (e.g. take rolling movement over sharp edges into account as far as possible) resulting in a wheel individual surface 3D model shape of the road along the travel path 16.

[0041] The method may comprise a step of searching the shape of the road surface traveled along for shape patterns 32 of interest having any potential impact onto aspects of driving of a manually or automated driven vehicle 10 especially regarding a reasonable speed to prevent damage to the vehicle 10 or accidents due to vertical acceleration and / or shock and / or impact.

[0042] A step S1 may comprise collecting motion data by a sensor system 18 of the vehicle 10, the motion data describing a motion of the vehicle 10 along the travel path 16.

[0043] A step S2 may comprise determining, by the surface detection device 12, a trajectory of a certain point 20 of the vehicle 10 body based on the motion data.

[0044] A step S3 may comprise determining, by the surface detection device 12, a roll angle and a pitch angle of the vehicle 10 body based on the motion data.

[0045] A step S4 may comprise determining, by the surface detection device 12, for each wheel of the vehicle 10 a respective trajectory of a respective wheel mounting point 22 of the respective wheel.

[0046] A step S5 may comprise determining, by the surface detection device 12, for each wheel a respective trajectory of a respective wheel hub center point 24 based on the respective trajectory of the respective wheel mounting point 22 and travel data of a respective suspension spring 26 provided by a respective suspension spring travel sensor device 28.

[0047] A step S6 may comprise determining by the surface detection device 12 for each wheel a respective trajectory of a surface contact point 30 according to a tire model of the respective wheel based on the respective trajectory of the wheel hub center point 24.

[0048] A step S7 may comprise determining the road surface shape 14 along the travel path 16 of the vehicle 10 based on the trajectories of the respective surface contact points 30.

[0049] A step S8 may comprise examining by the surface detection device 12 the road surface shape 14 along the travel path 16 for a presence of a shape pattern 32, which may be predefined.

[0050] A step S9 may comprise upon detection of the shape pattern 32, generating a shape event 34 indicating the presence of the shape pattern 32 and a location of the shape pattern 32 along the travel path 16 in an event database 38 in the vehicle 10. In some embodiments, a side slope may be detected and a side slope event 36 may be generated based on a property of a side slope such as the location of the side slope.

[0051] A step S10 may comprise upon generation of the shape event 34 determining an impact value 40 based on the motion data of the vehicle 10 and the shape event 34. In some embodiments, the impact value 40 may be based on at least of the motion data, the shape event 34, the side slope event 36, or other data. The data may be stored in the event database 38 and / or the central event database 42.

[0052] A step S11 may comprise upon determining the impact value 40 displaying a warning signal 46, which may be predefined, on an interface device 48 of the vehicle 10.

[0053] The specific shape patterns 32 may be called a shape event 34. The events may also cause inconvenience to people in the vehicle 10 caused by uneven road surfaces, especially road dips. The dips may be recognized by pattern recognition of road surface shape 14 for each wheel or for pairs of wheels, for example, right and / or left or for the entity of all four wheels by checking major characteristics like elevation above and / or below mean surface height, length of the events 34, 36 with different elevation, slope angle at beginning and / or end of events 34, 36, edge sharpness at beginning and / or end of events 34, 36, correlation and / or similarity of left and right wheel side. The events 34, 36 may be recognized by machine learning based on reference data of classified examples for the patterns such as the shape pattern 32 of interest based on the shape of the road for each wheel or for pairs of wheels (right / left) or for the entity of all four wheels. The events 34, 36 may be recognized by checking the spatial frequencies of a potential pattern in frequency space.

[0054] For example, road surfaces may have a general side slope to allow for water run off. On curves the side slope may be elevated along the degree of curvature for safety purposes such as to prevent vehicle 10 from being dragged out of curves and for comfort of the users of the road surfaces. The slopes of the road surface may be compared to the degree of curvature for safety purposes and / or comfort of the users of the road surfaces, and in some embodiments, the road surface events 36 may be determined based on a deviation between the slopes of the road surface and the degree of curvature for safety purposes and / or comfort of the users of the road surfaces.

[0055] Additionally, the method may comprise a step of classifying the recognized events 34, 36 into categories comprising for example road dip, speed bump, pot hole based on the data determined before and / or based on machine learning of classified examples. A checking of the correlation between the wheels may be performed to further determine the nature of the road surface shape 14. The shape 14 may be, for example, a pot hole only on one side of the vehicle 10, a dip first axle first then equally on second axle, a dip being deeper on right side of the vehicle 10 than on the left side.

[0056] In addition to the shape pattern 32 and shape event 34, the data determined may be continuously used to determine the side slope of the currently driven road and / or lane. If the side slope is exceeding a certain threshold that might depend on the curve radius in case of a curve, a side slope event 36 may be detected, the side slope event 36 may be detected in case of a slope in a tight curve that is lower on the outer side of the curve having the potential to carry the vehicle 10 out of the curve.

[0057] An analyzing of all the events 34, 36 to determine the events 34, 36 based on the impact value 40 or another property allows the vehicle 10 to determine the impact of the event 34, 36 to driving. For example, the properties such as a depth, a width, a maximum wall decline, a maximum wall incline (e.g. the first derivative of the elevation), a smoothness of transition at beginning of dip to go down, a smoothness of transition at lowest point between moving down and moving up, a smoothness of transition at the end of the dip (e.g. the second derivative of the elevation) may be determined and may provide data to determine a dip. For a pot hole, the properties of the depth, width and corner sharpness of an individual pot hole, but also the frequency and extension of a series of pot holes in close proximity may be used for the determination of the pot hole. For a speed bump, the height, width and corner sharpness may be used for the determination of the speed bump. For a slope event such as the side slope event 36, the slope along the curve and the associated curve radius along the curve, also the maximum inward / outward slope and associated radius may be used for the determination of the slop event.

[0058] The method may comprise a step of determining guidance based on the event 34, 36 or the impact value 40. The guidance may include a speed value such as a maximum speed, a recommended speed, and / or a moderate speed.

[0059] The analysis for the impact value 40 may be performed by an analysis of the determined data, e.g. through a vehicle 10 model modeling the suspension and the overall vehicle 10 movement trajectory and the impact based on the events 34, 36 to the vehicle 10 and / or the occupants inside vehicle 10.

[0060] The impact value 40 analysis may be performed by modelling the impact of the event 34, 36 and road surface shape 14 on a tire, suspension, and / or another component of the vehicle 10 to determine the deformation, forces, wear, puncture, and / or other damage risk to a component of the vehicle 10 such as the tire to prevent tire damage and / or limit tire wear.

[0061] The analysis for impact value 40 may be performed by modelling the impact of the event 34, 36 and road surface shape 14 on a tire, suspension, and / or another component of the vehicle 10 to determine the suspension spring 26 travel distance to prevent the suspension from being compressed to its limits and to prevent wear and tear of the suspension system.

[0062] The analysis may be performed by modelling the impact of the event 34, 36 and road surface shape 14 on a tire, suspension, and / or another component of the vehicle 10 including the vehicle 10. The model may include the overall geometry of the vehicle 10 during events 34, 36 to determine the distance between vehicle 10 underbody and road surface to prevent the vehicle 10 from touching the road surface to prevent vehicle 10 damage.

[0063] The analysis may be performed by modelling the impact of the event 34, 36 and road surface shape 14 on a tire, suspension, and / or another component of the vehicle 10 including the vehicle 10. The model may include the overall geometry of the vehicle 10 during events 34, 36 to determine the acceleration and forces to the suspension parts and to the vehicle 10 in general to prevent the vehicle 10 from getting damaged due to exceeding force or acceleration limits of the vehicle 10 or another component / part.

[0064] The analysis may be performed by modelling the impact of the event 34, 36 and the road surface shape 14 on tire, suspension, and vehicle 10 at the slopes determined and the driving trajectory expected to determine the vertical force for each of the wheels, especially in case of curves on the outer side of the curve, to maintain sufficient vertical force for each wheel needed, to maintain sufficient horizontal friction for each wheel, and to generate sufficient horizontal forces as needed to follow the movement trajectory in a safe manner. With sufficient forces, the present disclosure may prevent tires of the vehicle 10 from jumping into the air.

[0065] The analysis may be performed by modelling the impact of the event 34, 36 and the road surface shape 14 on tire, suspension, vehicle 10. The impact value 40 may be used to determine the forces and acceleration of occupants in seats and to prevent the occupants from feeling uncomfortable. The vehicle 10 may use the impact value 40 to adjust a driving parameter with the control device 50 to keep the occupants feeling safe and to prevent the occupants from having a roller coaster feeling. In some embodiments, the occupants can be modelled individually per seat based on the different seat locations in the vehicle 10.

[0066] The occupants can be modelled individually by estimating their weight or the measures applied for seat restraint systems (e.g. airbag weight classification by seat weight sensors). The occupants can be modelled individually by estimating model characteristics like weight and / or size based on camera, radar, and / or lidar images available from within the vehicle 10.

[0067] The occupants can be modelled alternatively by a machine learning system that may translate the shape and / or data into a speed impact based on training and datasets.

[0068] The method may comprise a step of providing a geographic reference to each event 34, 36 consisting at least of geographical coordinates or similar geographical reference system or database reference. The method may include data related to event 34, 36 such as like travel direction, specific lane the event 34, 36 is found on, elevation, road name, road number, level of roads on top of each other.

[0069] The method may comprise a step of combining the events 34, 36 and impact value 40 for events 34, 36 based on driving data and the geographic reference data to an event 34, 36 dataset. The data for events 34, 36 may include a set of attributes that may be part of a navigation database, a database for automated driving, or another separate database.

[0070] The method may comprise a step of sending data related to the event 34, 36 of each participating vehicle 10, of a data collecting vehicle 10, and / or a fleet via a mobile internet connection to a backend to be integrated in a dedicated event database 38, central event database 42, or database layer. The data transmission may be implemented via other communication methods.

[0071] The method may comprise a step of adding new events 34, 36 from data collecting vehicles 10 and by adjusting existing events 34, 36 by averaging the event 34, 36 data in case of additional measurements such as additional measurements from another vehicle 10 passing the same or identical event 34, 36. The adjustment of existing events 34, 36 may include removal of events 34, 36 if the vehicles 10 passing the location of an event 34, 36 may determine that the event 34, 36 no longer exists. For example, the pot hole may have been repaired by the city so the event 34 for the pot hole may be removed from the database 38, 42.

[0072] The method may comprise recurring updates for the database 38, 42, events 34, 36, road surface shape 14, and / or impact value 40. For example, the updates may be based on additional data from a participating fleet of vehicles 10 that may transmit data to and / or receive data from database 42. The updates may be localized. For example, the a local database, which may include the central event database 42, may update surrounding databases 38 of each individual vehicle 10. The update may include a differential update or full update of the event database 38, data base layer, and / or attribute dataset.

[0073] The method may comprise reoccurring checks of the driving trajectory for each vehicle 10 part of the fleet of vehicles 10 for events 34, 36 to forecast potential issues for vehicles 10. The forecast may be provided by using geographical reference information provided through the event database 38.

[0074] In case of an event 34, 36 identified in advance by checking the event database 38 and the actual driving path, the impact value 40 or another property for the event 34, 36 may be retrieved and compared with the trajectory of corresponding driving characteristics (e.g. current speed, recommended speed). A warning signal 46may be provided such as a warning to adjust the speed of the vehicle 10.

[0075] The actual driving path may be analyzed by comparing the lane the event 34, 36 is located with the predicted lane of the trajectory or by checking whether the driving direction of the travel path 16 corresponds with driving direction of the event 34, 36.

[0076] In case of an event 34, 36 identified, a recommend response to an impact value 40 or another property for the event 34, 36, the driving trajectory of the vehicle 10 may need to be adjusted. The adjusted driving trajectory may account for speed and other possibilities such as the level of automated driving. If car is driven manually, warning signal 46 may direct the occupant of the vehicle 10 to reduce speed. The warning signal 46 may be displayed on the interface device 48 or may be represented by a sound or haptics (e.g. vibration). For example, an automated driving vehicle 10 may, without occupant influence, slow the vehicle 10 down or adjust the driving trajectory to avoid events 34, 36. signs vehicle surface detection device road surface shape travel path sensor system certain point wheel mounting point wheel hub center point suspension spring suspension spring travel sensor device surface contact point shape pattern shape event side slope event event database impact value central event database server warning signal interface device control device steps

Claims

1. A method for determining a road surface shape (14) along a travel path (16) of a vehicle (10), by a surface detection device (12) of the vehicle (10), comprising the following steps performed by the surface detection device (12): - collecting motion data by a sensor system (18) of the vehicle (10), the motion data describing a motion of the vehicle (10) along the travel path (16);- determining a trajectory of a certain point (20) of the vehicle (10) body based on the motion data;- determining a roll angle and a pitch angle of the vehicle (10) body based on the motion data;- determining for each wheel of the vehicle (10) a respective trajectory of a respective wheel mounting point (22) of the respective wheel;- determining for each wheel a respective trajectory of a respective wheel hub center point (24) based on the respective trajectory of the respective wheel mounting point (22) and travel data of a respective suspension spring (26) provided by a respective suspension spring travel sensor device (28);- determining for each wheel a respective trajectory of a surface contact point (30) according to a tire model of the respective wheel based on the respective trajectory of the wheel hub center point (24);- determining the road surface shape (14) along the travel path (16) of the vehicle (10) based on the trajectories of the respective surface contact points (30).

2. The method according to claim 1, comprising the following steps performed by the surface detection device (12):- examining the road surface shape (14) along the travel path (16) for a presence of a predefined shape pattern (32); and- upon detection of the predefined shape pattern (32), generating a shape event (34) indicating the presence of the predefined shape pattern (32) and a location of the predefined shape pattern (32) along the travel path (16) in an event database (38).

3. The method according to claim 1 or 2, comprising the following steps performed by the surface detection device (12): - determining a side slope of the road surface shape (14) along the travel path (16); - examining the side slope along the travel path (16) for a presence of a predefined side slope event (36); and- upon detection of the predefined side slope event (36), storing the side slope indicating the presence of the predefined side slope event (36) and a location of the side slope event (36) along the travel path (16) in an event database (38).

4. The method according to any of the preceding claims, comprising the following steps performed by the surface detection device (12): - determining an impact value (40) of the event (34, 36) on the vehicle (10) according to a predefined impact estimation method based on the motion data of the vehicle (10);- adding the impact value (40) to the event (34, 36) in the event database (38); and - upon determination of the impact value (40), sending a predefined warning signal (46) to an interface device (48) of the vehicle (10) to give an acoustic and / or visual output in the vehicle (10).

5. The method according to any of the preceding claims, comprising the following step performed by the surface detection device (12): - synchronizing by the surface detection device (12) the events (34, 36) in the event database (38) with a central event database (42) of a server (44) exterior to the vehicle (10).

6. The method according to any of the preceding claims 1 to 5, comprising the following steps performed by the surface detection device (12): - examining the event database (38) for a presence of the event (34, 36) along a planned travel path (16) and / or an estimated travel path (16); and- upon detection of the event (34, 36), sending a predefined warning signal (46) to an interface device (48) of the vehicle (10) to give an acoustic and / or visual output in the vehicle (10).

7. The method according to claim 6, comprising the following step performed by the surface detection device (12):- upon detection of the event (34, 36), sending a predefined control signal to a control device (50) of the vehicle (10) to adapt a driving of the vehicle (10) according to a predefined adaption step.

8. A computer program product comprising program code means for performing a method according to any one of claims 1 to 7.

9. A non-transitory computer-readable storage medium comprising at least the computer program product according to claim 8.

10. A vehicle (10) comprising a surface detection device (12), configured to determine a road surface shape (14) along a travel path (16) of the vehicle (10), characterized in that- the vehicle (10) comprises a sensor system (18), configured to collect motion data describing a motion of the vehicle (10) along the travel path (16);- the surface detection device (12) is configured to determine a trajectory of a certain point (20) of the vehicle (10) body based on the motion data;- the surface detection device (12) is configured to determine a roll angle and a pitch angle of the vehicle (10) body based on the motion data;- the surface detection device (12) is configured to determine for each wheel of the vehicle (10) a respective trajectory of a respective wheel mounting point (22) of the respective wheel;- the surface detection device (12) is configured to determine for each wheel a respective trajectory of a respective wheel hub center point (24) based on the respective trajectory of the respective wheel mounting point (22) and travel data of a respective suspension spring (26) provided by a respective suspension spring travel sensor device (28);- the surface detection device (12) is configured to determine for each wheel a respective trajectory of a surface contact point (30) according to a tire model of therespective wheel based on the respective trajectory of the wheel hub center point (24); and- the surface detection device (12) is configured to determine the road surface shape (14) along the travel path (16) of the vehicle (10) based on the trajectories of the respective surface contact points (30).21

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