Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01C—MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY
  • G01C21/00—Navigation; Navigational instruments not provided for in groups G01C1/00 - G01C19/00
  • G01C21/26—Navigation; Navigational instruments not provided for in groups G01C1/00 - G01C19/00 specially adapted for navigation in a road network
  • G01C21/34—Route searching; Route guidance
  • G01C21/3453—Special cost functions, i.e. other than distance or default speed limit of road segments
  • G01C21/3461—Preferred or disfavoured areas, e.g. dangerous zones, toll or emission zones, intersections, manoeuvre types, segments such as motorways, toll roads, ferries

Definitions

• the present invention relates to a method for determining routes between a starting point ( ⁇ ) and an arrival point ( ⁇ ) for a digital road mapping system consisting of a set of sections and / or nodes, in which established route takes into account the level of sinuosity indicated by the user during his request.
• the assessment of the sinuosity index implies that all the details of the route of all the sections can be taken into account. Indeed, simplifying the representation of certain laces, or loops or other bends, in small-scale models (ie a scale with a low level of detail) produces errors that are often important for evaluation. sinuosity and therefore the resulting travel time. Thus, neither manual techniques nor conventional digital technologies currently make it possible to accurately evaluate the sinuosity index of given sections or paths, in particular very sinuous and long paths, where the real speed of the vehicle can vary from considerably compared to that calculated.
• the invention proposes a method for determining routes between a starting point ( ⁇ ) and an arrival point ( ⁇ ) for a digital road mapping system consisting of digital modeling elements of a road network comprising a set of representative sections of said road network and data relating to the sinuosity for at least a portion of these sections, and comprising the following steps: -on receives a route request including: -the departure and departure points; arrival; a selection of the sinuosity level to be preferred;
• each of said potential routes is assigned a rating based on its overall sinuosity index established from the sinuosity index of each of the sections constituting said potential routes; the potential route is chosen whose sinuosity index best corresponds to the sinuosity level of the request.
• Such a method makes it possible to classify or categorize the roads or portions of roads likely to be borrowed by a user, in order to allow him to be able to consider this aspect in his choice of route or route. Depending on the situation, the time available, its physical form, etc., a user can choose a route more or less sinuous.
• the type of sinuosity indicates a preference for the potential road having a sinuosity substantially higher or substantially lower.
• the type of sinuosity indicates a preference for the potential road having a sinuosity substantially the highest, substantially the lowest, or an intermediate sinuosity.
• the possible selection of the lowest sinuosity level implies for some routes considerable detours. In such cases, a compromise can be established between the sinuosity level and the total distance to be traveled.
• said dimension corresponds to the mean sinuosity index of the route, evaluated thanks to the following relation: ⁇ is (IStronboc X Ltronboc) / Ltotale, in which IStronabide corresponds to the sinuosity index of a given section , Ltronboc is its length, and Ltotale is the total length of the route.
• the step of identifying the plurality of potential routes further comprises the following steps:
• -a) we explore the sections adjacent to the node (or point) of departure or the selected node so as to determine the cost of each node to which these sections lead; -b) among these nodes, we select the one whose cost is the most favorable according to the criteria established (the shortest, the fastest, the most economical, favoring highways, etc., or a combination of these criteria); (c) taking up step "a" and continuing said exploration until the node whose cost is the most favorable corresponds to the arrival point.
• the criteria established the shortest, the fastest, the most economical, favoring highways, etc., or a combination of these criteria
• the nodes can be either nodes corresponding to points or actual data of the modeling elements, or virtual nodes, corresponding to intersections of sections.
• the multiplicity of valued nodes implies that a multiplicity of alternative routes are actually evaluated or considered.
• one or more routes that satisfy the criteria of the request are retained.
• the exploration of the nodes is carried out using the Dijkstra algorithm.
• the exploration of the nodes is carried out using the FORD algorithm.
• the preferred route is the one for which the sum of the odds or costs between the starting point and the arrival point is optimal.
• the establishment of the rating or overall cost can be done taking into account a number of parameters more or less important, as appropriate. For example, we can consider the sinuosity index alone, or with other parameters such as distance traveled, tolls, travel time, fuel economy, etc. Each of these different parameters may take on a more or less determining importance, by associating with each of the more or less important weightings, as the case may be, for example according to one or more wishes of the user.
• the invention also provides software comprising code elements programmed for the implementation of the previously described method, when said software is loaded into a computer system and executed by said computer system.
• This software can be in the form of a product recorded on a support readable by a computer system, including programmed code elements as stated above.
• the invention furthermore provides a device for determining routes between a starting point ( ⁇ ) and an arrival point ( ⁇ ) for a digital road mapping system consisting of numerical elements for modeling a road network comprising a set of sections representative of said road network and data relating to sinuosity for at least a portion of these sections, comprising: a data input unit, intended to receive, the data associated with a starting point ⁇ , an arrival point ⁇ and a desired sinuosity level for the route to be established;
• a storage unit comprising a set of modeling elements of a road network
• a calculation unit arranged to identify a plurality of roads each making it possible to connect the departure and arrival points by taking into account the sinuosity index of the sections of each of the routes.
• the sinuosity index is used in order to weight differently the paths having a high sinuosity index with respect to the paths having a lower sinuosity index.
• the device comprises a guiding unit, arranged to generate guidance information according to the map elements of the selected route.
• the invention finally provides a computer system comprising a device as previously described.
• FIGS. 1 to 3 show an example of sections on which the intermediate points (1 to 9) are indicated.
• Figure 2 illustrates a representation of a portion of a road network in the Lachaux region, with the right of each section of the database, its sinuosity index;
• Figure 3 shows a representation of a portion of a road network with three route possibilities between Vinça and Amélie-les-Bains, with three sinuosity indices that differ significantly.
• a “node” is a point of intersection between a first map or road network element (or other network) and a second element of such a network, in particular the intersection between a plurality of roadways.
• a node also designates a point of physical or qualitative change of a section, as for example a passage from two to three lanes, a change of the speed limit, a zone (even temporary) being the subject of work, a point breaking like a boundary, etc.
• section refers to a portion of a track between two nodes.
• Crossroads is an intersection of several roads at the same level.
• a "route” is a subset of points derived from the modeling elements of a road network, creating a link between data in such a way as to enable them to model or represent a route or route on the road network that connects a road network. starting point and a point of arrival.
• This subset is constituted by the data relating to the sections making it possible to connect the departure and the arrival.
• Data relating to sections refers to the identifications, the lengths of the sections and the spatial coordinates.
• This subset may be used to represent said route in different forms, for example by means of a graphic representation, preferably in the form of a map comprising the starting point, the arrival point, and the sections forming said route, or in the form of a "waybill" or list of instructions, comprising an enumeration or sequence of written instructions or pictograms, explaining to a possible driver of a vehicle, the various steps to follow to make said route.
• a graphic representation preferably in the form of a map comprising the starting point, the arrival point, and the sections forming said route
• a "waybill" or list of instructions comprising an enumeration or sequence of written instructions or pictograms
• the density of intermediate points for 100m of each section measuring more than 50m and having more than 5 intermediate points is calculated. Depending on this density, it subsequently applies penalty factors affecting the travel time (and of course the speed) of the different sections.
• FIG. 1 shows an example of a section on which the intermediate points (from 1 to 9 in this example) are represented.
• An intermediate point makes it possible to represent a change of orientation between two sections or between two portions of the same sections.
• a section representing a straight road has few intermediate points
• a section representing a winding road has a plurality of intermediate points.
• the following table presents an example of data obtained using the method according to the invention.
• This table includes the different sections to connect Chateldon in Vignolle-Basse.
• the table includes the identifiers of each section, their lengths, the calculated sinuosity indices, the standard travel time (without taking into account the sinuosity), and the time or duration of travel obtained taking into account the sinuosity. This example shows that the travel times of sections with high sinuosity index are likely to be strongly corrected by the method according to the invention.
• the route presented in the table is also shown in Figure 2.
• This figure illustrates an example of modeling elements presented in the form of a map, for a given sector, namely the surroundings of Lachaux.
• the sinuosity characteristics of the sections, obtained by means of the method according to the invention, are. indicated on the map. It is noted that the sections with a high index are numerous. The possibility of taking into account the impact of this sinuosity on the routes is therefore particularly important for sectors such as the one illustrated in this example.
• the method according to the invention enables users to take into account the type of situation by making it possible to generate precise routes and to calculate precisely the travel time.
• the routes are established by identifying a plurality of routes. This is done by selecting a first road network modeling element, preferably a node, near the starting point ( ⁇ ) and a second road network modeling element, preferably a node, near the end point. ( ⁇ ), identifying a plurality of routes, each consisting of a plurality of related modeling elements from the first element to the second element, and searching for at least one intermediate element for each of said roads in said set of modeling elements of road network.
• an algorithm of known type such as that of Dijkstra or Ford, is used to identify the routes likely to fulfill the criteria of the request.

Applications Claiming Priority (2)

Publications (1)

Family

ID=34949952

Family Applications (1)

Country Status (4)

Families Citing this family (8)

Family Cites Families (13)

• 2004
  • 2004-10-18 FR FR0411026A patent/FR2876819A1/fr not_active Withdrawn
• 2005
  • 2005-10-13 WO PCT/EP2005/011009 patent/WO2006042690A2/fr active Application Filing
  • 2005-10-13 EP EP05805838A patent/EP1805485A2/de not_active Withdrawn
  • 2005-10-13 US US11/665,654 patent/US20090222198A1/en not_active Abandoned

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events