Method and system for generating a round trip

Abstract

A method for generating a round trip on a network of transportation lines based on geospatial data is disclosed, wherein the geospatial data is partitioned using a network of a plurality of adjacent geospatial cells, each geospatial cell being associated with information about at least points of interest and transportation lines contained therein. The method comprises obtaining an origin for the round trip, wherein the origin is a geospatial location, and defining a start point and an end point for the round trip as a common point on the network of transportation lines based on the obtained origin, and obtaining route parameters that define at least one requirement and one constraint for the round trip.One of the cells containing the origin is designated as the origin cell, and cells surrounding the origin are evaluated based on their assigned information regarding the obtained path parameters. Some of the evaluated cells are selected based on the evaluation results, with the selected cells, together with the origin cell, forming a closed ring of adjacent cells. One or more intermediate points are determined based on the assigned information about the points of interest, with one point of interest in each cell being selected as one of the respective intermediate points. Path segments between the start point, the one or more intermediate points, and the endpoint are determined and connected to create a round trip from the start point, through the one or more intermediate points, to the endpoint.

Description

[0001] The present invention relates to the field of route planning, and more particularly, to the field of creating a round trip. More particularly, the invention relates to a method and system for creating a round trip along geographic transportation lines, e.g., roads, that include one or more intermediate points, such as points of interest, along the round trip.

[0002] Modern navigation systems, online mapping applications, or other services often include a route planning function to generate a route, typically from a start to a destination or between two or more points. Routes can be generated that take into account certain constraints or preferences of a user and thus apply a variety of optimization parameters, e.g., the shortest distance, the shortest time, the most economical fuel consumption, the avoidance of traffic jams, or similar. The points of a route can be part of a network of transport lines on geospatial data. Transport lines can be all types of roads, local roads, highways, or similar, but can also include unpaved paths or other geographical lines suitable for any type of transport. The type of transport line used for a planned route can depend on the type of transport mode used, e.g.,may involve a car or other motorized vehicle. However, it is also known for planning routes for hiking.

[0003] In particular, route planning can be based on a network of transportation lines contained in geospatial data. Geospatial data is information that has a geographical aspect. This means that the records in a dataset have coordinates, addresses, or other location identifiers that link them to a location on the surface of the Earth. The term "geospatial" combines "geo" (a prefix meaning "earth" or "land") and "space" (spatial or location-related). Geospatial data can specifically include latitude and longitude, addresses, postal codes, or even more complex references such as census tracts or areas within political boundaries. Geospatial data can be either vector or raster data.Vector data represents features in the form of points, lines, and polygons, while raster data represents features in the form of a grid of pixels, which is commonly used for various types of imaging data, such as satellite images or scanned maps. Geospatial data can also include a temporal dimension, such as weather data, which changes over time and influences route planning accordingly.

[0004] Points of interest ("POIs") can also be described using geospatial data. A point of interest is a specific location that might be useful or interesting to someone. POIs include various locations such as landmarks, tourist attractions, businesses, and government buildings. In navigation and mapping systems, POIs are used to help users find destinations and services such as hotels, restaurants, gas stations, and museums. Therefore, POIs can often play a role in route planning.

[0005] While route planning often involves a start and end point and possibly one or more intermediate points, certain situations may require the route to be a round trip visiting specific points or regions of the transportation network, while the start and end point of the route are the same point, e.g., in tourist travel or delivery logistics. Automatically generating such a round trip, especially with the addition of customization parameters, is not a trivial task.

[0006] Creating a round trip is comparable to the traveling salesman problem (TSP), a classic problem in theoretical computer science and combinatorial optimization. The task is to find the shortest possible round trip that visits a series of cities (each exactly once) and returns to the starting point. Formally speaking, it is a graph problem: given a graph in which the nodes represent the cities and the edges are valued by costs or distances. The goal is to find a permutation of the cities such that the entire route is as short as possible and each city is visited only once, returning to the starting city.However, while the TSP requires intermediate points (the cities) to be specified as input, it may be desirable to plan a round trip without specifying or even knowing any intermediate points, but only the origin where the route should start and end.

[0007] The problem of generating a round trip can be even more complex because road networks can vary greatly in density and shape. In some regions, the density of the road network may not be sufficient to provide round trips in all directions, or even at all. Therefore, it is not possible to reliably generate round trips that meet certain criteria without extensive knowledge of the network. However, collecting comprehensive information for each round trip request is costly and typically exceeds the self-imposed latency of several seconds of processing time.

[0008] An object of the present invention is to provide an improved approach for generating a round trip. In particular, it is desirable to improve one or more of efficiency, effectiveness, accuracy, and error rate when generating a round trip.

[0009] A solution to this problem is provided by the teaching of the independent claims. Various preferred embodiments of the present invention are provided by the teaching of the dependent claims.

[0010] A first aspect of the invention relates to a method, in particular a computer-implemented method, for generating a round trip in a network of transport lines based on geospatial data. In the method, an origin for the round trip is obtained, wherein the origin is a geospatial location, and a starting point and an end point for the round trip are determined as a common point on the network of transport lines based on the obtained origin. Route parameters are obtained that define at least one requirement and one constraint for the round trip. One or more intermediate points are determined on the network of transport lines in a geospatial region extending from the origin. In order to obtain a round trip from the starting point via the one or more intermediate points to the end point, route segments between the starting point, the one or more intermediate points, and the end point are determined and connected to one another.A validation value is determined for the obtained round trip using one or more validation parameters, and if the validation value is below the predetermined threshold, the route parameters are adjusted and the determination steps are repeated, or if the validation value is equal to or above a predetermined threshold, the obtained round trip is output.

[0011] Accordingly, the method can be viewed as a sophisticated technique for calculating or constructing a round trip for a specific location in a network of transportation lines based on geospatial data. A round trip can be generated that starts and ends at an origin, which can be specified, for example, by a user. The method can then automatically determine intermediate points to be traveled on the round trip. The round trip is then validated to ensure that the round trip meets certain requirements, such as quality requirements, in order to provide a round trip that can be enjoyable and meaningful and can appear as if it had been created by an expert, a local, or a tour guide. In particular, as explained in more detail below, the method can generate a round trip that can take into account a user's request, preferences, or wishes.The tour can be used, for example, for tourism purposes or to plan other tours, such as delivery, maintenance or security services.

[0012] By validating the round trip, inferior tours can be avoided, such as tours with many duplicate visits, streets that must be traveled twice or more, confusing intersections, or loops. If the validation value falls below a specified value, the round trip is recalculated with adjusted route parameters, i.e., the intermediate points and route segments are redefined. The resulting newly obtained round trip is validated again until a valid round trip is found. This iterative process can thus produce a valid round trip. Manual planning or even knowledge of the region to be traveled is not required, as the intermediate points and connecting route segments are determined automatically. A network of transport lines based on geospatial data, such as electronic maps, serves as a basis for automating the route search process.Geospatial data can also help improve the resulting round trip. Overall, the method provides an improved way to generate round trips that meets the requirements described above.

[0013] The term "round trip," as used herein, refers in particular to a route or tour that starts and ends at the same point, which can be considered the "origin." The origin can be a geospatial location, i.e., a location on the Earth's surface. The round trip can be described on a network of transportation lines, which is why the starting point and an end point, as well as intermediate points, are intended to be part of the network of transportation lines. Both the origin and the intermediate points of the round trip can be other geospatial locations, such as points of interest, that can be mapped to the network of transportation lines.

[0014] The term "transportation line" as used herein refers in particular to a line, i.e. a longer straight or curved continuous, predominantly one-dimensional geometric structure. A transport line is located on "geospatial data", i.e. on the Earth's surface, and can be a line that forms or is part of a transport infrastructure, e.g. for the transport of people or goods. Examples of transport lines are local roads, streets, highways or any other paved or unpaved way or path that can be traveled by any type of vehicle, such as a car, or by bicycle or on foot. A transport line can correspond to an area of ​​a more complex network that includes multiple transport lines, such as a road network with several interconnected roads.

[0015] The term "geospatial data," as used herein, refers to data that can be defined or expressed in a geographic coordinate system, such as latitude and longitude or UTM coordinates. In particular, and without limitation, a transportation line, such as a road, as represented by an electronic map, such as an electronic map based on map data for car navigation systems or maps on navigation applications on a computer or portable device, such as a smartphone or tablet computer, may be described by geospatial data or corresponding map data.

[0016] The term “acquiring” (or “obtaining”) data, e.g., route parameters, refers in particular to (i) the generation of these data by the “acquiring” entity itself, e.g., by means of one or more sensors or by deriving them from input data, such as user input, or (ii) the receipt of these data from an external data source.

[0017] The terms "first," "second," "third," and the like in the specification and claims are used to distinguish between similar elements and not necessarily to describe a sequential or chronological order. It is understood that the terms so used are interchangeable under appropriate circumstances, and that the embodiments of the invention described herein may be operated in sequences other than those described or illustrated herein.

[0018] Where the term "comprising" or "including" is used in this specification and claims, it does not exclude other elements or steps. When an indefinite or definite article is used to refer to a singular noun, e.g., "a" or "an" or "the," it includes a plural of that noun unless explicitly stated otherwise.

[0019] Furthermore, unless expressly stated to the contrary, "or" refers to an inclusive or, not an exclusive or. For example, a condition A or B is satisfied by any of the following: A is true (or present) and B is false (or absent), A is false (or absent) and B is true (or present), and both A and B are true (or present).

[0020] As briefly mentioned above, the obtained (and validated) round trip resulting from the procedure of the first aspect can be used in many different applications. A round trip can be applied to a tourism context to mimic the behavior of a tour guide. Applied in a security context, it can provide an unbiased patrol route for police, military, or other entities, covering a maximum of an area selected based on objective characteristics, such as incidents reported in the last week. Another application can be in a maintenance context, where the round trip can provide an optimal plan for the on-site visual inspection of the condition of roads and their surroundings.Based on the overall road quality, the condition at the last inspection, the time since the last inspection and the estimated traffic load, it might be possible to derive a deterioration model that simulates when a road section should be included in a round trip.

[0021] In the following, preferred embodiments of the method are described, which can be combined with each other or with other aspects of the present invention as desired, unless such a combination is expressly excluded or technically impossible.

[0022] In some embodiments, the validation value is determined to include one or more of the following: a shape factor and a deviation factor. The shape factor represents a ratio between a perimeter and an area defined by the obtained round trip on the geospatial data. In other words, a valid round trip should have a minimum roundness. Although this depends on other constraints such as the geography of the landscape or simply the user's preferences, a round trip can be considered valid or at least preferred if it is actually "circular" and not, for example, just back and forth. The deviation factor represents a deviation of the actual properties of the obtained round trip from the respective route parameters. This can help to determine the deviation of certain parameters of the resulting round trip, e.g.Distance or time, of the route parameters, is below a threshold. This makes it possible to provide a round trip that is optimized for the user's needs, such as a round trip that is not much longer or shorter than what the user expects or desires.

[0023] In some embodiments, the validation value is determined by calculating a weighted and normalized linear combination of at least the shape factor and the deviation factor. In this way, the validation can be customized and adapted to specific needs. For example, the above-mentioned factors (and possibly additional factors contributing to the validation value) can be weighted with individual weights. The normalization can be performed on a uniform domain, which can be a user-specific setting or learned from past journeys.

[0024] In some embodiments, the method further comprises post-processing the acquired round trip to identify and remove invalid sections of the acquired round trip. This can be used to clean up an acquired round trip. The invalid sections may include loops, duplicate or multiple trips, clusters, or the like, or a combination thereof, which could make the trip unpleasant. Such areas of the round trip may be charged higher costs to reduce the likelihood of being reselected when the round trip is recalculated.

[0025] Loops can be removed by deleting the transport lines that form the loop, so that each point in the network of transport lines is traversed only once. Removing loops can also remove self-intersections of the round trips. However, it should be understood that only small loops can be removed; larger loops may be allowed if this makes sense in the context of a particular routing request.

[0026] Multiple trips can be removed by displaying transport lines that are used more than once and recalculating at least part of the round trip, avoiding the displayed transport lines so that each transport line is used only once. Multiple trips can be considered as amplifying a "tentacle factor," which can describe the section of double or multiple use of transport lines. The tentacle factor should therefore be below a certain threshold. However, it is understood that in certain cases, duplicate trips may be permitted, for example, if their elimination would lead to a dead end.

[0027] Clusters of transport lines may also exist around an intermediate point; the clusters are removed by moving a corresponding intermediate point to a nearby location in the network of transport lines and at least partially recalculating the round trip. Clusters may result in many maneuvers at an intermediate point and can be removed by (slightly) relocating an intermediate point, e.g., by setting it to the first (local) maneuver and omitting the set of complex maneuvers. Clusters may be an indication of complex topology, which may affect the round trip and should be reduced or avoided.

[0028] In some embodiments, the invalid sections are identified by determining a lateral distance between sections of the round trip, with sections being identified as invalid sections if the determined lateral distance is below a predetermined threshold. The distance between two sections of the round trip can be calculated in various ways. For example, a clearance gauge can be constructed along the route that should not overlap. Another method can be to divide the round trip into small sections that should not overlap with another section during a virtual turn of, for example, 90 degrees. It is understood that the lateral distance can be assumed to be zero for sections of the round trip that are traversed twice.

[0029] In some embodiments of the present invention, which can be considered a first variant of the construction of the round trip, determining the one or more intermediate points comprises obtaining a travel direction as one of the route parameters and determining a center for the geospatial region in which the intermediate points are determined, wherein the center is located in the travel direction relative to the origin. This provides a method in which the area in which the round trip is to be located can be defined by specifying a travel direction, wherein the travel direction in particular starts from the origin. A center is then determined, which can be considered as a point or region around which the round trip is to move.The distance of the center from the origin may depend on route parameters such as the travel distance or the travel time, since the distance between the origin and the center influences the total length and duration of the round trip.

[0030] In some embodiments, the direction of travel is obtained by receiving user input specifying a desired direction as the direction of travel, or by determining a direction as the direction of travel based on environmental criteria of a geospatial region surrounding the origin. For example, the user may indicate a direction such as "south" or "north" (from the origin). The direction of travel may also be determined, e.g., depending on a description of the type of trip or by specifying specific points of interest relative to the origin.

[0031] In some embodiments, the method further comprises selecting a basic route geometry, wherein the basic route geometry is selected to extend around the center and include the origin along an outline thereof, and defining one or more auxiliary waypoints located on the outline of the basic route geometry. The waypoints can then be determined by projecting the auxiliary waypoints onto corresponding points on the network of transportation lines in the respective vicinity of the auxiliary waypoints. In particular, the waypoints are locations that are actually visited on the round trip, while the auxiliary waypoints are points on the outline of a selected basic route geometry. This is an auxiliary measure to roughly define the path that the round trip should take around the center.By providing a basic route geometry as a "control shape," the efficiency of generating the round trip can be increased. In particular, the iterative validation process can be accelerated compared to cases where waypoints are chosen arbitrarily without regard to a basic route geometry. When projecting the auxiliary waypoints onto waypoints, a plausibility check can be performed, e.g., by verifying whether the waypoints are actually reachable (and not, for example, located in a water area). The waypoints are projected from the auxiliary waypoints on the basic route geometry to points that actually lie on the transport line network.

[0032] In some embodiments, the basic route geometry is selected as a regular geometric shape, where the regular geometric shape is circular, elliptical, or polygonal. This facilitates the process. For example, a circle may be selected to describe the basic geometry of the round trip, with the center of the circle being the aforementioned center and the origin located on the outline of the circle.

[0033] In some embodiments, the auxiliary waypoints are defined as a selected number of equidistant points along the outline of the basic route geometry. While in principle a single waypoint may suffice, it is preferable to select at least two or more waypoints that "spanne" the area of ​​the round trip. It is understood that equidistant points may be advantageous in many cases, but other choices, e.g., depending on landscape conditions or user preferences (e.g., manually entered waypoints), may also be appropriate.

[0034] In some embodiments, determining the route segments includes determining an order in which the waypoints are traveled on the round trip, wherein the order is based on a clockwise or counterclockwise order of the respective auxiliary waypoints based on the outline of the basic route geometry. This provides an efficient way to determine the order in which the waypoints are to be traveled. Furthermore, this can accelerate the validation process, as this order selection can avoid or reduce undesirable route shapes, such as intersections or double-traveling of certain areas.

[0035] In some embodiments, the method further comprises defining at least one restriction area, wherein the restriction area includes at least one area that includes the center, wherein the restriction area defines a geospatial region that may not be traversed by route segments when determining the route segments. Avoiding the center or a central area within the overall travel area (essentially defined by the basic route geometry) for route segments that pass through it can effectively avoid intersections or "non-circular" route shapes, such as "star shapes," that involve many awkward back-and-forth trips between the center and an outer area. The restriction area may also be referred to as an "avoidance area" or "avoidance geometry."

[0036] In some embodiments, the restriction area is defined to have a minimum distance from each of the one or more auxiliary intermediate points. This avoids cases where, for example, the restriction area is chosen to be relatively large in the middle to allow sufficient leeway for determining the route segments. In other words, free spaces are maintained around the intermediate points to ensure proper route finding between the intermediate points.

[0037] In some embodiments, determining the route segments includes selecting the order of the waypoints based on the characteristics of the transportation lines, environmental criteria, or user preferences. In particular, selecting the clockwise or counterclockwise direction of travel may depend on other factors, such as the user's preferences, the daytime weather or forecast, or even aspects such as the quality of the scenic views when traveling in a particular direction. Determining the route segments may also include including or excluding transportation lines based on the characteristics of the transportation lines, environmental criteria, or user preferences.

[0038] In some embodiments, determining the one or more waypoints comprises at least one of the following: receiving user input specifying at least one waypoint, and selecting at least one point of interest from a collection (e.g., a database) of points of interest. In particular, in addition to automatically defining the waypoints as described above, manual entry of waypoints is also possible. Points of interest (POIs) can be valuable for a round trip, particularly in a tourist context, and can be, for example, certain sights, restaurants, or the like. POIs can also be defined and, if necessary, selected in other contexts.

[0039] In some embodiments, obtaining the origin includes obtaining a current user location, receiving user input specifying a desired geospatial location as the origin, or setting a default location as the origin.

[0040] In some embodiments, the route parameters include at least a travel direction, a travel time, a travel distance, a transportation line type, an intermediate point type, and the energy resources available for the round trip. The travel direction may be the travel direction explained above. The travel time may be a duration of the trip, i.e., an estimated total travel time, a minimum travel time, or a maximum travel time. The travel distance (travel duration) may be a planned travel distance, a minimum travel distance, or a maximum travel distance. The transportation line type may be defined as preferred or avoided types (e.g., dirt roads, highways, toll roads, etc.).

[0041] In some embodiments, the method further comprises obtaining route preferences, wherein the route segments are determined such that route segments are preferred that satisfy one or more of the obtained route preferences. The route preferences may comprise internal or external parameters. The internal parameters may specify characteristics of the transport lines, such as the number of curves, speed limits, road surface conditions, or the like. The external parameters may specify characteristics of an environment along the transport lines, such as preferred environmental regions, e.g., forests or mountains, the proximity to certain POIs, e.g., gas stations, restaurants, attractions, or even weather situations, e.g., the avoidance of thunderstorms or the like.

[0042] In some embodiments, the method further comprises obtaining haul line features, wherein the route segments are determined such that route segments are preferred based on one or more of the obtained haul line features. In this way, the round trip can be further optimized or customized for specific needs. As described in more detail below, the haul line features can include at least one of the following data: road sensor data, traffic monitoring data, public warning data, aerial inspection data (e.g., UAV sensor data obtained from an unmanned aerial vehicle (UAV) such as a drone), and charging station availability data (e.g., available electric vehicle charging station along the road).

[0043] In some embodiments of the present invention, which can be considered a second variant of the round trip construction, the geospatial data is divided using a grid of a plurality of adjacent geospatial cells, each of the geospatial cells being associated with information about at least points of interest and transport lines enclosed therein. In this variant, the validation process can be omitted, particularly because of the use of the grid of cells. However, it is understood that the validation process and other features described above can also apply to this variant. It is also understood that the use of the cell grid described herein can also be applied to the first variant described above to the extent possible.

[0044] In the method of this embodiment, one of the cells in which the origin is located is designated as the origin cell. Cells surrounding the origin cell are evaluated based on information associated with them with regard to the acquired route parameters. Some of the evaluated cells are selected based on the evaluation results, wherein the selected cells, together with the origin cell, form a closed ring of neighboring cells. The one or more intermediate points are then designated based on the associated information about the points of interest, wherein in each selected cell, a point of interest is selected as one of the respective intermediate points. The route segments are then designated as described above to obtain the round trip. In other words, in this variant, the round trip is oriented along the cell grid.Since the cells are assigned information about the transport lines and POIs available in each cell, an evaluation can be performed to select the cells that are most promising for a round trip. A POI is identified in each cell, e.g., a POI that is most relevant for a specific routing request, thus providing an easy way to find intermediate points. Because the cells are selected to form a closed ring, it is ensured that a closed round trip is constructed that has an appropriate circular shape. Post-processing can then be performed, for example, as described above, to optimize the route defined by the round trip.

[0045] In some related embodiments, evaluating the cells includes calculating a score as the evaluation result, represented by a normalized numerical value. Numerical values ​​can be easily compared and ranked, facilitating the selection of cells for the tour.

[0046] In some embodiments, the score represents a combination of a POI score and a connectivity score, where the POI score represents the relevance of points of interest in a cell with respect to the route parameters, and the connectivity score represents the connectivity available between neighboring cells via transportation lines. These two factors provide an efficient way to generate a pleasant round trip. Since points of interest should be the center of attention, the goal is to find out which cells provide the most interesting or relevant points of interest. The POI score can also take into account the number of points of interest per cell. If there is no point of interest in a cell, the center can be used as the "point of interest" if necessary. Furthermore, the cells should provide convenient connectivity for a pleasant round trip.This can take into account the number or density of transport lines within a cell, and in particular, the transport lines that extend into neighboring cells. In this way, a closed ring of cells can be identified that, on the one hand, contains the most relevant POIs and, on the other hand, provides suitable connections for determining route segments that, when connected together, form a round trip.

[0047] In some embodiments, the cells are selected such that the closed ring of selected cells has the highest score among the closed rings of cells surrounding the original cell, where the score of a closed ring of cells is the sum of all scores of the cells in the closed ring.

[0048] In some embodiments, the route parameters include a thematic category of points of interest and a travel time. In particular, these two parameters (together with an origin) may be sufficient to generate a round trip.

[0049] This is advantageous because it allows the user's input to be kept to a minimum while creating a pleasant round trip.

[0050] In some related embodiments, information about one or more of the following points is assigned to each cell. One or more land cover classes that affect the network of transport lines can be provided per cell, e.g., land cover classes that are highly likely to affect the network of routes, such as bodies of water, rivers, mountainous regions, or the like. One or more land cover classes that specify the environmental character of a cell can also be provided. This can be relevant, as it can influence the thematic category of the round trip, such as urban areas or forests. As already mentioned, cell-to-cell connectivity can be provided, specifying a connection of a cell to its neighboring cells with respect to the network of transport lines.Last but not least, each cell is assigned information about the points of interest it contains, which can be grouped by thematic categories and ranked according to their importance. The importance (relevance) and the respective ranking may depend on the route's requirements.

[0051] In some embodiments, the plurality of geospatial cells are formed by a plurality of adjacent hexagons. Although other cell grids, such as squares, may be used, a hexagonal grid is particularly suitable for covering the surface of the Earth without gaps. A ring of hexagons may also be suitable for describing a circle-like shape for a circular route.

[0052] A second aspect of the present invention is directed to a data processing system configured to perform the method of the first aspect. The data processing system can, in particular, be configured by one or more computer programs to perform the method of the first aspect. Additionally or alternatively, the configuration can be implemented in whole or in part by appropriate hardware.

[0053] A third aspect of the present invention is directed to a computer program or a computer program product comprising instructions which, when executed on a data processing system according to the second aspect of the invention, cause the system to perform the method according to the first aspect of the invention.

[0054] The computer program (product) can in particular be implemented in the form of a data carrier on which one or more programs for carrying out the method are stored. This is preferably a data carrier such as a CD, a DVD or another optical medium, or a flash memory module. This can be advantageous if the computer program product is to be traded as a standalone product independently of the processor platform on which the one or more programs are to be executed. In another implementation, the computer program product is provided as a file on a data processing unit, in particular on a server, and can be downloaded via a data connection, e.g. the Internet or a dedicated data connection, such as a proprietary or local network.

[0055] The system of the second aspect can accordingly comprise a program memory in which the computer program is stored. Alternatively, the system can also be configured to access a computer program that is available externally, for example, on one or more servers or other data processing units, via a communication connection, in particular to exchange data that is used during the course of execution of the computer program or represents outputs of the computer program.

[0056] The explanations, embodiments and advantages described above in connection with the method of the first aspect also apply in a similar manner to the other aspects of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Further advantages, features and applications of the present invention are provided in the following detailed description and the accompanying figures, wherein: Fig. 1 schematically illustrates an exemplary embodiment of a method according to the present invention; Fig. 2 schematically illustrates an exemplary geospatial region with a specific geospatial location as the origin for a round trip; Fig. 3 schematically shows the geospace region Fig. 2 illustrated with a direction of travel; Fig. 4 schematically illustrates examples of basic line geometries; Fig. 5 schematically illustrates a circular basic line geometry with auxiliary intermediate points; Fig. 6 to Fig. 8 schematically illustrate the construction of a restriction area; Fig. 9 schematically shows the geospace region Fig. 3 with the basic line geometry from Fig. 5 illustrates; Fig. 10 schematically shows the geospace region Fig. 9 with the restriction area of Fig. 8 illustrates. Fig. 11 to 15 schematically illustrate the determination of route segments; Fig. 16 schematically illustrates the resulting round trip; Fig. 17 and Fig. 18 illustrate a first example of corrections to a round trip; Fig. 19 and Fig. 20 illustrate a second example of corrections to a round trip; Fig. 21 and Fig. 22 illustrate a third example of corrections to a round trip; Fig. 23 to 25 illustrate examples of cell information; Fig. Figure 26 schematically illustrates an evaluation of four adjacent cells; Fig. 27 schematically illustrates scoring and selection of cells surrounding a cell of origin; Fig. 28 schematically illustrates the identification of invalid sections; Fig. 29 schematically illustrates an example of removing invalid sections from a round trip; and Fig. 30 to 32 illustrate an example of generating a round trip using a hexagonal cell grid.

[0058] Fig. 1 illustrates a flowchart of an exemplary embodiment 100 of a method of the first aspect of the present invention. The method 100 is also described in particular with reference to Fig. 2 to 16. The method is configured to calculate a round trip 10 for a specific location on a network of transport lines based on geospatial data.

[0059] To further improve the method, it is conceivable to augment the transport lines with additional information, which serves as supplementary information for generating the round trip 10. The input data can be selected according to the respective context and used to optimize the result with regard to transport lines to be avoided or preferred. A non-exhaustive list of possible sources of augmentation input data is provided below. The data can be useful for further refining the determination of the route segments, e.g., to better meet certain needs or to better fulfill the requirements of a specific routing request.

[0060] First, road sensor networks can be deployed to monitor the condition of a road. For example, data on temperature or wetness can influence the selection or avoidance of certain areas. Traffic monitoring systems that monitor vehicle flow and congestion can provide relevant data that can also be useful. Satellite data can also be taken into account, for example, to provide information on local or regional weather conditions, or changes in the terrain as an indicator, e.g., of possible landslides or other obstacles that may impact transport routes. It is also conceivable to consider public warnings, e.g., warnings of natural disasters such as flooded areas or forest fires. Especially if an electric vehicle is to be used, the utilization of charging stations can be relevant, e.g.,to prioritize transport routes closer to less busy charging stations. This can also lead to a better distribution of charging station usage. UAV-based sensors, such as optical RGB or infrared cameras or radar sensors, can provide inspection data from bridges, road surface conditions, or indications of potential activity in restricted areas. Based on this information, nearby transport routes can be prioritized to automatically enforce inspection round trips.

[0061] The method can consider a general direction (travel direction) from the given location (origin 2) and a travel time and / or a travel distance as basic adaptation parameters (route parameters). A round trip 10 can be constructed that not only has a circular shape, but also includes areas that should be interesting and efficient for travelers, maintenance workers, patrols, or other users. This means that it is possible to avoid repetitions and travel through a section of the transport lines only once during the round trip.

[0062] Optionally, a user can define preferred attractions (viewpoints, beaches, archaeological sites, castles, ...) or road features (road classes, slipperiness, road surface types, ...) or preferred regions (regions with recent severe weather, not inspected for a long time), which can further modify the characteristics of the round trip.

[0063] Fig. Figure 2 illustrates an exemplary geospatial region 1, ie a region on the Earth's surface in which a round trip 10 according to the method 100 of Fig. 1 is to be generated. In a first phase, the parameters and preferences defined by the user are obtained. In particular, in step S1, a starting location (origin 2) is determined, which can be aligned with a geospatial network of transport lines 11. This is identical to the end point of the round trip 10. The origin 2 can be the user's current location, e.g., defined by a geopositioning system such as GPS. Alternatively, the origin 2 can be set manually by the user. The origin 2 can also be set to a POI, e.g., a hotel, to serve as a default location for multiple users.

[0064] Route parameters (or user parameters) can then be obtained (cf. database D1). In particular, as in Fig. 3, a preferred travel direction 3 with respect to the starting position can be determined (step S2). This can be a manual input by the user, e.g., if a user wishes to travel south. It is also conceivable to determine the travel direction 3 automatically by using a direction that best meets the user's vague specifications, e.g., if a user indicates that they wish a round trip "with the most forest areas" or similar.

[0065] Furthermore, restrictions can be set for the round trip, such as the desired travel time, the available time, and the available fuel / battery charge. General route preferences can also be set, which serve to adapt the actual route to a user's individual preferences. These can be internal route parameters such as the number of curves, speed limits, or road surface conditions, and / or external route parameters such as preferred surrounding regions, e.g., forests or mountains, proximity to POIs, e.g., gas stations, restaurants, attractions, or weather conditions, e.g., avoiding thunderstorms or the like.

[0066] In step S3, the intermediate points 8 are then determined. This is done in particular with the help of auxiliary intermediate points 6. The auxiliary intermediate points 6 serve to fundamentally control the route of the round trip 10 on the transport lines 11 of the geospatial network. Further route restrictions can be introduced to achieve the desired route result. Further route parameters (database D2) can be taken into account. First, a basic route geometry 5 (5', 5") is defined as the round trip "control shape". The shape could be any geometric shape of fixed size, e.g., circle, rectangle, ellipse, as in Fig. 4. The basic route geometry 5 extends around a center 4, which is given by the origin 2 and the travel direction 3, where the origin 2 is located on the shape (outline) of the basic route geometry 5. It is understood that the number of auxiliary intermediate points 6 can be at least three in order to actually span a region and enable the creation of a proper round trip. The size of the geometric shape 5 can be static or derived from an average speed setting, e.g., 40 km / h. The average speed could be calculated in advance for a geographical region (e.g., a district, a state, a country) by selecting random points and calculating the average speed connecting these locations. For further optimization, the shape of the round trip could depend on the shape of the land and water masses (e.g.,by calculating the overlap of land mass and desired round trip type).

[0067] Referring to Fig. 5 are now auxiliary intermediate points 6 on the round trip form (the basic route geometry 5; here the circle was taken from the examples of Fig. 4 selected). This can be done, for example, by a sample of equidistant points (four points in the example from Fig. 5) or by searching for the most prominent points within a buffer around the round trip, e.g. tourist attractions or POI.

[0068] In a step S4 (possibly using data from a geospatial network, see database D3), a restriction area 7 is constructed, which allows for finer control over the round trip route and can help avoid undesirable situations. A first section 7' ​​of the restriction area ("avoidance geometry") is defined in the center 4 of the round trip control form 5 (see Fig. 6). This is intended to prevent the resulting round trip 10 from failing and to ensure that trips to intermediate points 8 from the center 4 are served by the same transport lines 11. The shape of this avoidance geometry 7' can be based on the shape of the round trip control shape (i.e., the basic route geometry 5, which is a circle here). Additional avoidance geometries can be defined by vegetation zones, protected zones, military zones, non-routable geographical topologies, disaster areas, remote locations without gas stations, etc., to increase the quality of the resulting round trip.

[0069] The constraint area can therefore be constructed as follows. As explained above and in Fig. 6, a circular geometry is chosen as the basic avoidance geometry 7' and placed in the center 4 of the control shape 5 to avoid round-trip routes from entering the center 4 of the control shape 5. Then, as in Fig. 7, distance buffers 7" are constructed around the (auxiliary) intermediate points 6 to ensure that there is sufficient space around these points for correct route finding. The final avoidance geometry 7 (i.e., the final restriction area) is then constructed by the difference of the basic avoidance geometry 7' with the individual distance buffer geometries 7" (the result is shown in Fig. 8 shown)

[0070] Based on the auxiliary intermediate points 6, the intermediate points 8 are determined, i.e. the locations that are actually to be passed through on the round trip 10. For this purpose, the auxiliary intermediate points 6 are projected onto significant locations based on the network of transport lines 11 that form the intermediate points 8. The projection can be done in various ways, e.g., onto the nearest road segment, as in Fig. 9 shown. Fig. 10 shows a result by combined views of Fig. 8 and Fig. 3.

[0071] The auxiliary waypoints 6 may also be projected onto the nearest POI selected from a group of static or user-defined POIs taken from a digital map or a database, or onto a nearby point that the user has not visited in the past (so that the round trips are different each time), or onto the nearest point on land if the waypoint is on water, or onto a nearby stretch of road with a particular road profile, e.g., with a particular surface, curve or otherwise classified as interesting, or onto a point representing a cluster of several nearby places of the same type, e.g., tourist attractions, or onto the most important POI nearby (e.g., a viewpoint).Importance can be derived from the amount of information provided about that point or any other ranking scheme, such as the number of photos taken by users at that location. It should be understood that intermediate points (locations) may be restricted to a specific subset of road classes (e.g., primary, secondary, tertiary), exclude ferry routes, and exclude long road segments where turning is not possible, such as highways.

[0072] It can be useful to check the plausibility of the determined intermediate points 8, especially to avoid expensive route calculations as early as possible. For example, intermediate points 8 can be discarded if a certain percentage lies on water (e.g., when trips along the coast towards the open sea are requested) or if another difficult-to-navigate route topology exists, e.g., narrow mountain passes, fjords, etc. If the round trip is discarded, a valid round trip can still be generated by adjusting the parameters, e.g., by changing the travel direction 3 by + / -30 degrees to stay close to the original direction while allowing some flexibility, and starting again with the construction of the (auxiliary) intermediate points.

[0073] After the intermediate points 8 have been determined, the round trip 10 can be calculated (step S5). Fig. Figures 11 to 15 show how route segments 9 are determined between the intermediate points 8, including the origin 2 (i.e., the starting and ending points). The direction of travel of the intermediate points 8 (clockwise or counterclockwise) can be chosen arbitrarily. However, if there are problems in areas with one-way streets, the direction can be changed. The direction can also be chosen with reference to the weather, for example, to avoid traveling through a rainy area that later moves away, or to avoid traveling against the low sun.

[0074] An optimal path from the starting point to the end point (which is identical to the starting point) containing the intermediate points 8 can be found as in Fig. 11 to 15. It is understood that transport routes 11 within the restriction area 7 (avoidance geometries) are excluded. Depending on the user's preferences, certain road features can be included or excluded. If no path has been found, a valid round trip can still be generated by adjusting the parameters, e.g., by changing the travel direction 3 by + / -30 degrees to stay close to the original direction while allowing some flexibility, and starting again with the construction of intermediate points 8.

[0075] The generated round trip 10 is then validated against certain validation parameters (see database D4) (step S6). A valid round trip should have a minimum circularity, i.e., the ratio of circumference to area should be within a valid range. Furthermore, it should be ensured that the "tentacle factor," i.e., the length of the duplicate road sections, is below a threshold. Furthermore, it should be ensured that the deviation of certain parameters of the resulting round trip, e.g., distance or time, from the input parameters is below a threshold. A "perturbation rule" can be applied, which can be defined as a linear combination of all other rules with individual weighting and a normalization of the rules to a uniform domain, which can be a user-specific setting and learned from past trips.

[0076] If it is determined that the round trip 10 is not valid, the method returns by adjusting the parameters (step S7) and starts again from step S3 with the construction of intermediate points 8. If a valid round trip 10 is obtained (possibly by iteratively repeating the process) or if the iterative generation of a round trip is enabled and a timeout has been reached, the round trip 10 is output. An exemplary result is shown in Fig. 16 shown.

[0077] The result can be adjusted to achieve a more pleasant round trip. For example, the construction of round trip 10 may result in loops. Such loops can be discarded by identifying route segments traveled twice in the same direction. In addition to cutting loops, there may be short sections where a road segment is traveled twice. These edges can be excluded from the final route, but only if a dead end is not formed. It may be necessary to relocate locations; i.e., if many maneuvers are close to an intermediate point, this is an indication of a complex topology that can distort the round trip. In this case, the intermediate point is simplified by setting it to the first (local) maneuver and omitting the set of complex maneuvers. Examples are in Fig. 17 to 22 and described in more detail below.

[0078] Fig. 17 shows a first example where the round trip 10 has a loop 12 around an intermediate location. Loops 12 should generally be suppressed because they degrade the visual appearance of the round trip, increase the round trip time without increasing the attractiveness since the loop takes place in a small area around the intermediate location, and they lead twice over the same road, which is boring for the tourist driver or unproductive for an inspection trip. The loops 12 can be removed by the following steps. The edges that are driven on twice are identified. The route is then reconstructed, iterating over all edges. Crossing the first edge that is driven on twice is the indication for skipping. All subsequent edges are skipped and not written into the answer (the new route) until the edge that is driven on twice is passed again.Then the skipping stops and the edges are written back into the answer. The result without loops is shown in . Fig. 18 shown.

[0079] Fig. Figure 19 shows another example where the round trip 10 has a "tentacle" 13 around an intermediate location. Tentacles 13 should generally be suppressed, as they degrade the visual appearance of the round trip and increase the round trip time without increasing the attractiveness, as the same road is traveled twice, which is boring for the tourist driver or unproductive for an inspection trip. This is remedied by avoiding double-traveled local roads with the following mechanism. The edges that already occur in the route can be included in an extra-cost edge vector and are then generally avoided when searching for the route. The result without tentacles is shown in Fig. 20 shown.

[0080] Fig. Figure 21 shows another example where the round trip includes 10 unnecessary turning maneuvers (i.e., a “cluster” 14) around an intermediate location. Such behavior should generally be suppressed, as it increases fuel / battery consumption. It can also be tiring for the tourist driver or unproductive for an inspection trip, as many maneuvers take more time and therefore fewer regions can be covered per time. This can be remedied by shifting intermediate locations using the following steps. Clusters 14 are identified around an intermediate location, and the intermediate location is shifted to the first maneuver of a cluster. The round trip is then reconstructed with the shifted intermediate location. The result without clusters is shown in Fig. 22 shown.

[0081] As a variant, the calculation of the round trips could be parallelized by varying the (individual) parameters within reasonable ranges. For example, reducing or enlarging the round trip control form results in a set of round trips with different distances and durations. From this set, the round trip that best fits the user's preferences can be selected.

[0082] One variant can pre-calculate a set of round trips for frequently requested locations or POIs, e.g., hotels, transport depots, main train stations.

[0083] A variant can present tours with variations of parameters and external and internal route preferences to a user, who then indicates whether they like the tour or not, without knowing the underlying parameters and preferences. After a sufficient number of tours have been presented, the system can derive a profile for the user to present the most suitable tours for future requests.

[0084] A variant can adapt the round trip control form taking into account the average waiting / rest times at certain POIs to better meet the preferred round trip time specified by the user.

[0085] For more precise control of the round trip, preference geometries can be incorporated into the generation process, similar to avoidance geometries. Unlike avoidance geometries (restriction areas), they draw the route into specific areas.

[0086] The variant of the method for generating a round trip 10 described above is based on a basic route geometry, such as a circular shape, which is easy to obtain, but does not necessarily take the shape of land masses into account. For example, intermediate points could end on bodies of water or in inaccessible mountainous regions. The variant described below (which may be an extension of the first variant) further considers information about land cover and POI locations. To make this work, additional pre-calculated geospatial datasets are used, in particular based on a hexagonal grid.

[0087] Road networks can vary greatly in density and shape. In some regions, the density of the road network may not be sufficient to provide round trips in all directions, or even not at all. Therefore, it is not possible to reliably create round trips that meet certain criteria without comprehensive knowledge of the network. However, collecting comprehensive information for each round trip request is costly and typically exceeds the self-imposed latency of several seconds of processing time. Therefore, a method is proposed to obtain an abstract and simple data structure of the influencing factors of a round trip before attempting to calculate the actual route.

[0088] For this purpose, a hexagonal grid 20 is introduced with information on the above-mentioned factors. For example, the hexagonal hierarchical geospatial indexing system uber / H3 may be used. However, it is understood that other network or indexing systems may be used where appropriate. The information associated with each cell 21 of the hexagonal grid may include the following: Land cover classes that are likely to affect the route network, such as bodies of water, rivers, and mountainous areas, are provided. Land cover classes that affect the thematic category of the round trip, such as urban areas or forests, may also be provided. A cell-to-cell connectivity factor is also provided, e.g., the connection of a cell to its neighbors with respect to the network of transport lines 11.Cells 21 are also assigned information about the points of interest they contain, representing the routing locations of the round trip, grouped by thematic category and ordered by importance.

[0089] In general, a hexagonal grid has certain mathematical advantages over any other grid. Hexagons are optimally space-filling, meaning they are the most circle-like regular polygon known to densely cover a plane. The sphere (the Earth's globe) can be mosaicked more regularly with hexagons than with a rectangular grid. In a hexagonal grid, the neighbors of a grid cell are all equidistant (unlike square or triangular grids).

[0090] To identify the cells to be selected for a region of the tour 10, the cell content is evaluated as explained below.

[0091] Fig. Figure 23 illustrates an evaluation of cell contents in terms of land cover classes. The land cover is classified into types, where the area represents 100% of the cell area. A ranking of the land cover can then be created by area fraction and type. In particular, this procedure can further be used to evaluate whether a cell is urban, rural, mountainous, etc. An output could be as in Fig. 23 shown (dark = high density of urban areas; light = low density of urban areas).

[0092] Fig. Figure 24 illustrates an evaluation of the cell content with respect to the points of interest (POIs). The POIs are divided into categories. The number of occurrences, i.e., the number of POIs of a particular category, is variable and can be zero. It may be intended to evaluate popularity. For this purpose, the POIs are linked to additional category-dependent metadata, e.g., photos taken near tourist destinations or geographical variables such as the height of a peak. A ranking regarding the importance (relevance) of POIs depends on a thematic category of the tour. For example, high mountain peaks are more important for a tourist tour through the Alps, whereas popular architecture or historical buildings may be more important for a sightseeing tour through a city center.If there is no POI 23 in a cell 21, the center of the cell can be considered as the routing location (intermediate location). The single most important POI 23 per cell 21 is then chosen as the routing location (intermediate location). This ensures that the POI 23 are not very close to each other, which could lead to complicated round-trip geometries. An output could be as in . Fig. 24 shown (dark = high density of viewpoints; light = low density of viewpoints).

[0093] Fig. Figure 25 illustrates an evaluation of the cell content in terms of cell-to-cell connectivity. The cells 21 can be arranged according to the number and type of transport line 11. This could be done as in Fig. 25. Each triangle within a hexagon indicates that a transportation line 11 (e.g., a highway) is connected to the neighboring hexagon.

[0094] The assessment options described refer to a non-exhaustive list of geospatial parameters. Other data such as population density or road quality measures, weather information, safety risks, travel or citizen warnings can be provided in the same way. Such data can also be obtained through appropriate sensors as described above.

[0095] It may be beneficial to normalize the values ​​individually to obtain a comparable score, e.g., linearly between 0 and 1, or 0% and 100%, or exponentially (1 1; 10 2; 100 3; and so on), or any other normalization scheme. The weighted average of the scores can then be used to obtain an overall score. The weighting scheme can be fixed or user-defined. The scores are updated when the raw data changes.

[0096] Fig. Figure 26 shows an example with four cells 21. Dots in the cells indicate POIs 23, while arrows between the cells 21 indicate the respective connectivity between the cells 21 via transport lines 11. The right-hand part shows an example of composite scores for individual cells. More specifically, in cell A, the POI score is 100% because the most popular POI of the cell selection is contained in this cell. The connectivity score of cell A is also 100% because the cell meets the required connectivity requirements. Thus, the total score for cell A is (100 + 100) / 2 = 100%. In cell C, the POI score is 40%. The POI score is normalized to the best POI of the selection. However, the connectivity score of cell C is 0% because the cell does not meet the required connectivity requirements. Thus, the total score of cell C is (0 + 40) / 2 = 20%.

[0097] Referring to Fig. 27 explains how a round trip 10 can be generated according to this variant using the hexagonal grid 20. The middle figure in Fig. 27 is enlarged to improve the readability of the numbers in cell 21. In general, it is advantageous if the effort required to create a tour is as minimal as possible. This is especially true in cases where the user has no further knowledge of the geographical area. This makes it possible to create well-composed and thematically defined tours without any local knowledge. The required inputs can be limited to the following parameters: the origin 2, e.g., the starting (and ending) point of the tour, the desired category of points of interest to be visited (a category corresponds to a thematic collection of types that subjectively or objectively describe characteristics of points and areas of interest, e.g., in a tourist context: "historical," "scenic," "maritime"), and the desired duration of the tour.

[0098] First, the user enters a location that can be assigned to a cell, ie the original cell 22 (left in Fig. 27). Next, the scores of the first and second ring of hexagons around the original cell 22 are evaluated (center of Fig. 27). In this way, a closed ring 24 of cells 21 with the best score for a particular location category combination can be determined. After the optimal ring 24 has been identified, the most important POI 23 from each cell 21 is selected. The POI collection is then sorted clockwise or counterclockwise and passed to the routing engine (right in Fig. 27).

[0099] Finally, a route is returned that connects all specified points of interest, attempting to maintain a roughly circular shape. However, no detailed information about the road network was taken into account in this first routing step. Thus, the initial routing request is optimized for a circular arrangement of POIs 23 and a reduction in the interference of the road network; however, geometric irregularities may still appear in the initial result. This is because the data in the network has been significantly reduced and abstracted in favor of computational power and latency.

[0100] As for the first variant (method of Fig. As explained in section 1), a validation process is applied to avoid returning irregular shapes of round trips. Proportions of route segments considered invalid reduce the overall quality. It is understood that the procedures below can also be added to the validation step S6 described above. In particular, invalid segments of a route are duplicated portions of the route ("tentacles"), enclosed loops connected to the main route, zigzag patterns (if avoidable), or self-intersections.

[0101] Fig. Figure 28 illustrates one way to identify invalid segments 25. In particular, sections that are too close together are potentially invalid, such as (small) loops, tentacles, or self-intersections. Thus, the above-mentioned patterns (with the exception of large loops) can be detected by checking predefined segments of the route for free space. Fig. 28 in a) to d) shows how invalid sections, which are the two vertical lines, are detected and removed. First, the route shape is simplified and divided into segments 26 of fixed size ( Fig. 28a). These segments 26 are then rotated by 90 degrees (dashed lines in Fig. 28b). Intersections of rotated segments with parts of the simplified line shape are detected ( Fig. 28c). The basic idea behind this is to detect road segments that are close to each other in relation to the segment length, i.e., for longer segments, the roads must be further apart than for a small outburst. These detections result in the linked segment being classified as invalid, e.g., as an element of a geometric irregularity (dotted segments in Fig. 28d are invalid). If invalid segments 25 divide the overall geometry into several parts (see Fig. 28e), even smaller geometries 27 are marked as invalid ( Fig. 28f)

[0102] The length of the invalid segments 25 in relation to the valid segments represents the geometric quality. If the geometric quality is below a certain threshold, improvement attempts are made to correct the irregular shape, as in the simplified example route in Fig. 29 shown.

[0103] The route shape ( Fig. 29a) is divided into valid and invalid segments 25 as described above (see Fig. 29b). All routing locations are then mapped to the valid segments ( Fig. 29c). In this way, POIs 23 that were previously reached via invalid segments are mapped further away from their original location. POIs 23 that are reached via valid segments are connected to the round trip in the same way. In a second routing request using the optimized locations, invalid routes 25 are excluded from the overall shape with high probability. At this point, the average distance to the original set of POIs 23 increased, while the geometric quality also increased. The result is shown in Fig. 29d. 5. These steps of "quality assessment" and "quality improvement" can be repeated iteratively until the geometric quality reaches the desired threshold or the locations can no longer be mapped to a better location.

[0104] An example of the procedure using the hexagonal grid, including the corresponding corrections, is given in Fig. 30 to 32. As shown in Fig. 30, an optimal ring of grid cells 21 near the center is obtained (in this case, the leftmost cell was selected as the origin of the trip; the cells are shown and the highest-ranking points of interest within each cell are connected by a dashed line). The route segments connecting the POIs 23 with the highest ranking are determined. A correspondingly obtained round trip 10 is Fig. 31. The geometric quality is then assessed and invalid line segments are identified (shown as white areas in the lower three mesh cells in Fig. 31). The POIs 23 are assigned to the nearest valid sections of the route, and the generation of the round trip 10 is repeated (iteratively) to obtain a new route. This procedure is terminated as soon as a threshold for the geometry quality is reached (otherwise, the above steps are repeated until the threshold is reached). A result shows Fig. 32, ie a round trip 10 without invalid sections causing the irregularities, and therefore a pleasant round trip.

[0105] While at least one exemplary embodiment of the present invention has been described above, it should be appreciated that a wide variety of variations exist. Furthermore, it should be understood that the described exemplary embodiments illustrate only non-limiting examples of how the present invention may be implemented and are not intended to limit the scope, application, or configuration of the apparatus and methods described herein. Rather, the foregoing description provides those skilled in the art with constructions for implementing at least one exemplary embodiment of the invention, with the understanding that various changes in the functionality and arrangement of the elements of the exemplary embodiment may be made without departing from the subject matter defined by the appended claims and their legal equivalents. LIST OF REFERENCE SYMBOLS 1 Geospatial region 2 Origin 3 Direction of travel 4 Center 5 Basic line geometry (control form) 6 Auxiliary intermediate point 7 Restricted area 8 intermediate points 9 route segments 10 round trip 11 transport lines 12 loop 13 tentacles 14 clusters 20 Hexagonal grid 21 Cell 22 Original cell 23 Point of Interest (POI) 24 rings 25 Invalid segment 26 segments 27 Unconnected section

Claims

[1] A method for generating a round trip (10) in a network of transport lines (11) on geospatial data, wherein the geospatial data is divided using a grid (20) of a plurality of adjacent geospatial cells (21), each of the geospatial cells (21) being associated with information at least about points of interest (23) and transport lines (11) included therein, the method comprising: - obtaining an origin (2) for the round trip (10), wherein the origin (2) is a geospatial location, and setting a start point and an end point for the round trip (10) as a common point on the network of transport lines (11) based on the obtained origin (2); - Obtaining route parameters that define at least one of a requirement and a constraint for the round trip (10); - determining one of the cells (21) in which the origin (2) is located as the origin cell (22); - evaluating cells surrounding the original cell (22) based on their respective associated information with regard to the acquired route parameters; - selecting some of the evaluated cells (21) based on the evaluation results, wherein the selected cells (21) together with the original cell (22) form a closed ring (24) of adjacent cells (21); - determining one or more intermediate points (8) based on the associated information about the points of interest (23), wherein in each selected cell (21) a point of interest (23) is selected as a respective one of the intermediate points (8); and - Determining route segments (9) between the starting point, the one or more intermediate points (8) and the end point and connecting the determined route segments (9) to obtain a round trip (10) from the starting point via the one or more intermediate points (8) to the end point. [2] The method according to claim 1, wherein evaluating the cells (21) comprises calculating a score as an evaluation result represented by a normalized numerical value. [3] The method of claim 2, wherein the score represents a combination of a POI score and a connectivity score, wherein the POI score represents a relevance of the points of interest (23) in a cell (21) with respect to the route parameters and the connectivity score represents a connectivity available between neighboring cells (21) through transport lines (11). [4] Method according to claim 2 or 3, wherein the cells (21) are selected such that the closed ring (24) of the selected cells has the highest score among the closed rings (24) of cells surrounding the original cell (22), the score of a closed ring (24) of cells (21) being the sum of all scores of the cells (21) in the closed ring (24). [5] Method according to one of the preceding claims, wherein the route parameters comprise a thematic category of points of interest (23) and a travel time. [6] Method according to one of the preceding claims, wherein each cell (21) is assigned information about one or more of the following: - one or more land cover classes affecting the network of transport lines (11); - one or more land cover classes that specify the environmental character of a cell; - a cell-to-cell connectivity specifying a connection of a cell (21) to its neighboring cells (21) with respect to the network of transport lines (11); - included points of interest (23), grouped by thematic category and ordered by importance. [7] Method according to one of the preceding claims, wherein the plurality of geospatial cells (21) are formed by a plurality of adjacent hexagons. [8] Method according to one of the preceding claims, further comprising determining a validation value for the obtained round trip (10) using one or more validation parameters and - if the validation value is below the predetermined threshold, adjusting the route parameters and repeating the determination steps or, - if the validation value is equal to or greater than a predetermined threshold, outputting the obtained round trip (10). [9] The method of claim 8, wherein the validation value is determined to include one or more of the following: - a shape factor, wherein the shape factor represents a ratio between a circumference and an area defined by the acquired round trip (10) on the geospatial data; and - a deviation factor, wherein the deviation factor represents a deviation of the actual properties of the obtained round trip (10) from each of the obtained route parameters. [10] The method of claim 9, wherein the validation value is determined by calculating a weighted and normalized linear combination of at least the form factor and the deviation factor. [11] The method of any preceding claim, further comprising post-processing the acquired round trip (10) to identify and remove invalid sections (25) of the acquired round trip (10), wherein the invalid sections (25) comprise at least one of the following: - loops (12), wherein the loops (12) are removed by deleting transport lines (11) forming the loop (12) so that each point in the network of transport lines (11) is traversed only once; - multiple journeys (13) of transport lines (11), wherein the multiple journeys (13) are removed by displaying transport lines (11) that are traveled more than once, and the round trip (10) is at least partially recalculated, avoiding the displayed transport lines (11) so that each transport line is traveled only once; and - clusters (14) of transport lines (11) around an intermediate point, wherein the clusters (14) are removed by moving a corresponding intermediate point to a nearby location in the network of transport lines (11) and at least partially recalculating the round trip (10). [12] The method of claim 11, wherein the invalid sections (25) are identified by determining a lateral distance between the sections (26) of the round trip (10), wherein sections (26) are identified as invalid sections (25) if the determined lateral distance is below a predetermined threshold. [13] Method according to one of the preceding claims, wherein determining the route segments (9) comprises determining an order of the intermediate points (8) in which they are travelled on the round trip (10), the order being based on a clockwise or counterclockwise order. [14] Method according to one of the preceding claims, wherein determining the route segments (9) comprises at least one of the following: - selecting the order of the intermediate points (8) based on the characteristics of the transport line, environmental criteria or user preferences; and - Including or excluding transport lines (11) based on the properties of the transport lines, environmental criteria or user preferences. [15] Method according to one of the preceding claims, wherein determining the one or more intermediate points (8) comprises at least one of the following: - receiving a user input specifying at least one intermediate point (8); - Selecting at least one point of interest from a collection of points of interest (23). [16] A method according to any one of the preceding claims, wherein obtaining the origin (2) comprises obtaining a current user location, receiving user input specifying a desired geospatial location as the origin, or setting a default location as the origin. [17] Method according to one of the preceding claims, wherein the route parameters comprise at least a direction of travel, a travel time, a travel distance, a type of transport line, a type of intermediate point and the energy resources available for the round trip (10). [18] Method according to one of the preceding claims, further comprising obtaining route preferences, wherein the route segments (9) are determined such that route segments (9) are preferred which satisfy one or more of the obtained route preferences, wherein the route preferences comprise at least one of the following: - internal route parameters, wherein the internal route parameters specify characteristics of the transport lines (11); and - external parameters, wherein the external parameters specify characteristics of an environment along the transport lines (11). [19] Method according to one of the preceding claims, further comprising obtaining transport line features, wherein the route segments (9) are determined such that route segments (9) are preferred based on one or more of the obtained transport line features, wherein the transport line features comprise at least one of the following: - road sensor data; - traffic monitoring data; - public warning data; - air inspection data; and - Data on the availability of charging stations. [20] A data processing system configured to perform the method according to any one of claims 1 to 19. [21] A computer program or computer program product comprising instructions which, when executed on one or more processors of a system according to claim 20, cause the system to perform the method according to any one of claims 1 to 19.

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