EP0902406B1 - Method for transmitting traffic data and for analysing the road traffic network, traffic-evaluating central unit and terminal therefor - Google Patents

Abstract

A digital route map is defined in terms of a number of sections (1-17) that are connect between nodes (A-T), e.g. junctions. The sections are defined to allow different part routes (W1-W4) to be defined. A mobile communication link to a central station allows route data to be transmitted in sections to a vehicle (18). The data is stored in different sections of memory.

Description

The invention relates to a method for transmitting route data and a Traffic control center and a terminal.

The transmission of route data between a vehicle and a control center, in particular the transmission of data (FCD) relating to a path covered by a vehicle in each case from the vehicle to the control center or, for example, the transmission of further transmitted data which can be assigned to a transmitted path in a control center, such as Travel times of vehicles put a heavy burden on the transmission route due to the very high number of vehicles. In particular, due to the transmission of route data determined by many individual vehicles to the distances traveled in each case, and of travel times etc. for the respective route transmitted, due to the large number of vehicles, a very large amount of data to be transmitted is required. However, the transmission channels available for transmission are not unlimited in terms of their capacity.
DE 195 08 486 A1 discloses a method for transmitting position data by mobile radio between a vehicle and a control center, in which position data in the form of a point (with the specification of length and width) are recorded with a GPS receiver after a specific interval, whereby two points are connected to a vector and a first vector train is formed from all the vectors obtained in this way. For data reduction, the first vector is approximated by straight lines with an increasing number of straight lines until the maximum distance of the actual position data from the straight line lies below a predetermined threshold value, whereupon the position data reduced in this way are transmitted.
Access to information in a digital map of the traffic network is not recommended for data reduction.

The document EP-A-0 263 332 relates to a receiver for traffic radio broadcasts, in which a coarser grid in the form of segments is superimposed on an exit road network, which segments in turn contain a plurality of route segments. The resulting list contains the names of the segments and the route segments contained therein.
The respective segment is determined by the transmission of the respective route segment.

The object of the present invention is to optimize the transmission of route data between a vehicle and a control center.

This object is achieved by a method according to claim 1 and by a Traffic detection center and a terminal according to claims 19 and 22 solved.

The invention optimizes the transmission of route data by reducing the Redundancy, i.e. by increasing the information density during transmission. For this will each have one or more edges in the digital map of the Traffic route network, in which vehicles move, to partial routes summarized. Route data can be identified with a description of the partial route which they relate to are transferred. Other dates such as travel times, Environmental data, temperatures etc. can e.g. by designating a partial route and of the location on the partial route. So it's just a one-dimensional one Path parameters such as the distance from the beginning of the partial route to the description an exact location of train-related information such as travel times or Environmental data required within a partial route, which with a lower Redundancy than with a two-dimensional (geographical longitude and latitude) Location is possible; the place name is therefore a relatively short piece of information.

Edges of the traffic network in which vehicles are moving Sections of roads, lanes or lane groups or the like in one Exit traffic network map and connected to other edges by nodes. On The nodes of a traffic route network can lie on one, two or more edges. If there is only one edge at a node, it is an end point of the Infrastructure network. If there are two edges on a node, it can be a subdivision of a street, roadway, lane group etc. in the longitudinal direction in act several edges, two edges each by a node are connected. If there are three or more edges on a node, it acts is a junction or intersection of roads, lanes, lane groups etc. An intersection with more than three edges can be divided by several Knots with three edges to be replaced. The different directions of a street can be represented by one or more edges. Route data in the sense of Claims include data that is covered by one vehicle at a time Identify the path, namely the edges or the partial paths, each one or include several contiguous edges and together the covered Make way. If, based on transmitted route data, the route of a vehicle in a digital map of a transport network in the head office can also Further data such as travel times can be assigned to this route.

Particularly advantageous embodiments of the invention result from the Dependent claims.

Route data transmitted can in particular be one from a vehicle with one Traffic detector traveled route and from vehicle to headquarters be transmitted. The data determined in this way in the central office can in particular for travel time statistics and for later recommendations on the choice of routes Vehicles are used.

The route data can also relate in particular to one of the vehicles Head office recommended route and from the head office to the vehicle respectively can be transmitted to several vehicles. So that a vehicle can be used for one or determined several routes based on travel time statistics in a central office Travel times are informed and advice on the selection of routes.

The transmission of a route is expediently carried out by the transmission of Designations of the partial routes forming it. A way can be from one or exist several partial routes. The names of the partial routes can be found in the Central and in the vehicle in identical or different databases stored with an assignment of edges forming a partial path one partial route each; instead can also be used in the head office and in the vehicle at least one set of rules for the formation of partial paths from edges be saved and for the identification of partial routes of a route to be transmitted these rules are used. Also several different ones Databases and / or sets of regulations for the formation of partial routes in each case Vehicle and be stored in the headquarters, with the transmission of one Path related data the set of regulations or the database to which the route data relate to it, which increases the universality.

Furthermore, when assigning one or more edges each Partly because of the road types of these edges are taken into account; thus can for example, partial routes from edges representing highway sections or from Edges representing highway sections and country roads are formed.

At least one vehicle expediently becomes one from the control center recommended route communicates the expected travel time. From a vehicle expedient to the head office for the distance or partial routes covered by the Path time needed transmitted. This means that occupancy statistics from In addition to routes, directly determine travel times for certain routes.

The associated period or time is preferably transmitted for route data. The exact time or a time can thus be determined for route data determined by a vehicle quantified period of time are transmitted and stored in the headquarters. The control center can also transmit route data, what time period, for example what time of day, what day of the week or which day of the year these route data relate to, for example Precise route recommendations for traffic jams occurring at certain times of the year can be transmitted.

By analyzing an edge and knot Traffic route network generating one specified in the claims The target file from a source file is used to reference partial routes in the Suitable transmission of route data between a control center and a vehicle Target file created. Different can be used to generate the target file Approaches can be chosen. For example, starting from a as Starting nodes selected nodes of the network, partial routes are defined in such a way that with ascending numbering of the partial routes, one partial route through if possible long left turn, starting from the starting node. This regulation is very easy to implement.

In a traffic recording center or a terminal, a The inventive method advantageously implemented in the form of a program become.

Fig. 1

als einzige Figur schematisch eine digitale Straßenkarte eines Verkehrswegenetzes.

Further features and advantages result from the further claims and from the following description of an embodiment with reference to the drawing. It shows:

Fig. 1

the only figure schematically shows a digital road map of a traffic route network.

Figure 1 shows a digital road map of an edge 1 to 17 and node A to T. extensive traffic network. An edge here comprises a section of the route a street. Alternatively, it would also be possible to have several for one section of the route Edges, for example one edge for each direction of travel or one for each One lane or one edge for turning lanes, etc. define. The edge 1 is between the two nodes A and B, the edge 2 is between nodes B and C, edge 3 is between the Nodes C and D etc. In the very small traffic network shown, the nodes are A, G, J, P, T each start node of the digital map of the traffic network, ie Knots, of which only one edge or only one edge of the considered Street classes. The nodes B, D, L are branch nodes, i.e. nodes with at least three adjacent edges; this means, for example, from the edge 1 At node B, drive a vehicle in the direction of edge 2 or edge 10 can that there is a real possibility of branching off. Instead of like here three edges each, a junction node can also have more than three edges, for example at an intersection; however, it is also possible to order the here selected representation with branch nodes with exactly three edges each preserved, even at intersections with more than three edges, several junction nodes to define from which exactly three edges each originate. The nodes C, E, F, H, I, K M, N, Q R are nodes, of which only two edges, for example Edge 2 and 3 start from node C. These edges can be in one Digital road map representing traffic route network for specific purposes, such as. Congestion detection may be important, however, they are used to analyze a route and transmission of route data relating to this route, in particular Travel times, not important. A network of traffic routes can also be found representative digital map, i.e. output file, to form a partial route of the Traffic network with target file representing low redundancy Consideration of edges and / or nodes of only a certain road class, for example, freeway, are taken into account; also e.g. from one Output file, several target files can be created for each street class.

If with the existing as an output file, a traffic network representing digital road map in Figure 1 a way and this way further route data in question should be transmitted by The passed nodes and / or the passed edges are transmitted. For example, in the edge 1 in the direction of arrow V from Starting node A to the starting node J vehicle 18 moving over the edges Move 1, 2, 3, 7, 8, 9. This way can be in a terminal in the vehicle due to a position detection system (e.g. GPS) and / or one Odometer and / or a speedometer and / or the detection of the Steering movements of the vehicle and / or a digital road map etc. detected become. Furthermore, a total time required for this route can be added to the route and for partial routes of the route, partial route times are recorded. This route data should be transmitted from the vehicle 18 to a control center. This can be done from a terminal in the vehicle 18 to the central office, for example by radio, in particular mobile radio, respectively. For this purpose, for example, transmission according to GSM, in particular GSM SMS, can be selected in the form of a short message.

In the example shown in FIG. 1, a vehicle 18 can travel From A to J the edges 1, 2, 3, 7, 8, 9 and the time required for this as Route data can be transmitted to a control center. Because of the variety of However, vehicles generate a very large amount of data. The capacity of the However, the available transmission medium is limited. Therefore the resulting data volume can be kept as low as possible.

For this, the traffic route network is broken down into partial routes. One or each can be used several edges 1 - 17 form a partial path. In the terminal and in the control center at least one set of regulations for the formation of partial routes in one Traffic network or one according to a set of regulations from the digital Road map of a traffic route network (output file) less formed redundant (information technology compressed) digital road map of the Traffic route network (i.e. destination file) must be saved. The identification of a path when transmitting a route covered and travel times relating to it etc. from the vehicle to the control center or from the control center to a vehicle, if there are several sets of regulations for the formation of Partial or multiple target files created according to these sets of rules are available, stating the set of regulations applicable to the partial routes or the applicable target file.

The regulations for dividing the transport network into partial routes can be chosen in this way be independent of the digital road maps that exist in the terminal and the headquarters can be used. In particular, in the terminal and in the Central does not necessarily have the same digital street map or the same Version (update) of a digital road map is available. The procedure is too for different cards or card versions in the terminal and in the head office formable.

For data reduction of a traffic route network by forming partial routes Multiple edges and / or nodes are different sets of rules possible.

For example, a partial route can be defined between two nodes each are either output nodes A, G, J, P, T or branch nodes B, D, L, respectively. The partial routes of the digital channels shown in FIG. 1 result from this version Road map of a traffic network as follows:

The partial route W ₁ comprises the edge 1, the partial route W ₂ comprises the edges 2, 3, W ₃ = 4, 5, 6, W ₄ = 7, 8, 9, W ₅ = 10, 11, W ₆ = 12, 13, 14, W ₇ = 15, 16, 17. It can be saved according to which set of rules partial branches W ₁ to W _{7 are} formed. It can also be stored in a target file which edges are contained in a partial route W ₁ to W ₇ and / or which nodes form the end of a partial route W ₁ to W ₇ .

Another set of regulations for the formation of partial routes in a digital road map representing a traffic route network can be as follows: A partial route is formed starting from any exit node A with increasing node numbering, by turning left for as long as possible until a further exit node G, J, P, T. Paths between this output node A and the other output nodes are thus detected. After all possible routes from the output node A have been processed, a further rule can lie in the choice of a further output node G, all of which except the route to the output node A already considered being defined accordingly as partial routes. Another requirement may be to proceed accordingly with the remaining exit nodes. According to these methods, the partial routes X ₁ would result for the route from node A to node G, X ₂ = A, J; X ₃ = A, P; X ₄ = A, T; X ₅ = G, J; X ₆ = G, P; X ₇ = G, T; X ₈ = J, P; X ₉ = J, T; X ₁₀ = P, T, so that the number of partial routes X ₁ to X _{10 is} the faculted number of output nodes. Here, a route as transmitted route data would only contain a partial route.

Another set of regulations for the formation of partial routes can also are defined as follows: From an arbitrarily selected output node A turns left as long as possible to another exit node G, J, P, T analyzed; partial routes are only used for routes between exit nodes and Output node and possibly additionally between output node and Intersection node defined when from traffic data recorded by Vehicles shows that a relevant number of vehicles are traveling this route. This means that there are only a few routes in the traffic route network, each only one or include several defined partial routes, so that only for these routes Transmission of the route data concerning them is optimized; since, however, a very large one Some of the vehicles travel at least at certain times, which is a lot include heavily trafficked partial routes, this also results in a very good one Optimization of those involved in the transmission of route data from vehicles Amount of data.

For example, a set of regulations for the formation of partial routes may look as follows: the first partial route Y ₁ comprises the edges 1, 2, 3, 7, 8, 9, the partial route Y ₂ comprises the edges 15, 16, 17, the partial route Y ₃ comprises the edges 10, 11, 12, 13, 14, the partial route Y ₄ comprises the edges 4, 5, 6. This means that all routes which a vehicle 18 can drive from the output node A can be defined and transmitted with a very small amount of data , However, according to this set of regulations, routes between node C and node D, for example, cannot be transmitted in the form of partial routes with little redundancy, which is, however, not a problem if a few vehicles travel from C to D.

Claims (24)

1. Method of transmitting route data, in particular by mobile phone, between a vehicle (18) and a control centre,
   where route data are transmitted with designations of part-routes (W₁, W₂, W₄), each comprising one or more adjoining borders (1;2, 3;7, 8, 9),
   where at least some of the part-routes (W₁, W₂, W₄) comprise a number of borders (2,3; 7, 8, 9) in the digital map of the traffic route network.
2. Method as in Claim 1,
   characterised in that
   route data on a route travelled through by the vehicle (18) with a traffic sensor are transmitted from the vehicle (18) to the control centre.
3. Method as in one of the preceding Claims,
   characterised in that
   route data on a route are transmitted from the control centre to the vehicle (18).
4. Method as in one of the preceding Claims,
   characterised in that
   the transmission of a route is effected by transmitting the designations of the part-routes that form it, the designations (W₁ to W₈) being held in memory in the control centre and in the vehicle (18) in the same (W₁ to W₇; W₁ to W₇) or different (W₁ to W₈ ; X₁ to X₁₀) databases, in particular in the form of target files created in accordance with Claim 14, with an assignment in each case to a part-route (W₄) of borders (7, 8, 9) which form in each case one part-route (W₄).
5. Method as in one of the preceding Claims,
   characterised in that
   the transmission of a route is effected by transmitting the designations of at least the part-routes that form it, at least one set of instructions for forming part-routes from borders being stored in both the control centre and the vehicle.
6. Method as in Claim 5,
   characterised in that
   a number of sets of instructions for the formation of part-routes are stored, and in that, together with route data for a route, the relevant set of instructions or a designation of this set of instructions is also transmitted.
7. Method as in one of the preceding Claims,
   characterised in that
   between one node, from which at least three borders branch off, and another node, from which at least three borders likewise branch off, a part-route is formed.
8. Method as in one of the preceding Claims,
   characterised in that,
   when assigning borders to part-routes, the types of road (motorway) of the borders are taken into consideration.
9. Method as in Claim 8,
   characterised in that
   each part-route is formed only from borders of the same type of road, preferably only part-routes between terminal nodes of this road class being defined.
10. Method as in one of the preceding Claims,
    characterised in that
    the expected journey time for a route is transmitted from the control centre to a vehicle for this route.
11. Method as in one of the preceding Claims,
    characterised in that
    the journey time needed for the route and/or for part-routes is transmitted from the vehicle to the control centre for a route covered by the vehicle.
12. Method as in one of the preceding Claims,
    characterised in that,
    for route data, the period or time at which the route data were recorded, or for which period or time the route data were established, are transmitted.
13. Method as in one of the preceding Claims,
    characterised in that,
    in the case of route data recorded by a number of vehicles for a number of routes, assigned journey times and assigned recording periods or recording times are saved in the control centre in a statistics file.
14. Method as in one of the preceding Claims,
    characterised in that
    for the purpose of analysing a traffic route network which has borders (1 to 17) and nodes (A to T) and which is present in the form of a source file comprising at least details of connections between borders and/or nodes, a target file is created representing the traffic route network, by forming each of a number of part-routes by combining, in each case, one or more borders or nodes from the source file which are linked to each other; and, for each of these part-routes, a designation of the part-route and a list of the borders and/or nodes it includes are saved in the target file.
15. Method as in Claim 14,
    characterised in that
    borders or nodes which are not included in a part-route are also saved in the target file.
16. Method as in Claim 14 or 15,
    characterised in that
    borders for a specific class of road (motorway) are analysed separately in each case and are stored in their own target file or target part-file.
17. Method as in one of Claims 14 to 16,
    characterised in that,
    between a node from which at least three borders branch off and another node from which at least three borders likewise branch off, a part-route is defined in each case.
18. Method as in one of Claims 14 to 17,
    characterised in that,
    starting from a selectable initial node (A), the part-route numbered 1 is formed by turning off to the left from it and at other nodes, and that other part-routes, in each case with the next lowest number, are each formed by turning off to the left for as long as possible.
19. Traffic recording centre for recording traffic, with a memory, a receiver, a program stored in the memory for implementing the method as in one of the preceding Claims, and a control system for processing the program.
20. Traffic recording centre as in Claim 19,
    characterised in that
    it has a target file created in accordance with Claim 14.
21. Traffic recording centre as in Claim 19 or 20,
    characterised in that
    it has a transmitter.
22. Terminal, in particular for a vehicle, for recording traffic information, with a memory, a transmitter, a program stored in the memory for implementing the method as in one of Claims 1 to 18, and a control system for processing the program.
23. Terminal as in Claim 22,
    with a receiver.
24. Terminal as in Claim 22 or 23,
    with a target file generated in accordance with Claim 14.

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