EP0941534B1 - Method for determining itinerary data - Google Patents

Abstract

A method for determing travel route data, especially within the framework of navigation of a vehicle, using a digital map which is kept in a central control station and in which static and dynamic parameters are stored by route section for the detected traffic routes, wherein the static parameters include at least structural features of the respective traffic route. The dynamic parameters include at least one conductance value and one load function of the respective section of the traffic route. The dynamic parameters are derived one time for the presetting of starting values from the structural features and, from that point, are continuously adapted to the real conditions of the respective sections of the traffic route with ensured availability of dynamic data independent from static parameters. The travel route data are determined on the basis of the relevant dynamic parameters.

Description

The invention relates to a method for determining travel route data according to the Preamble of claim 1.

Method for determining route data, in particular in the context of Route guidance of a vehicle are known in principle and for example in WO 89/02142 described in detail. In particular, this is done in a central Control center traffic routes segment by segment in a digital map, especially one digital road map managed, each segment having a traffic route between represents two nodes, which can be intersections, junctions or the like and is described by static or dynamic parameters. The static Parameters essentially include structural features of the traffic route, such as road type, road condition, number of lanes, permitted speed and Attributes such as curvy, steep inclines or descents. Beyond that it is known to assign each segment fixed sensors with which dynamic Parameters such as the number of vehicles passing a segment per unit of time as well as their speed. Inserting 5.1a.

The document W096 / 29688 describes a method which uses a digital map dynamically of current traffic data measured by "floating cars" changes. There is also one So-called "historical database", which receives information from inductive loops and with who verifies and reconciles the information.

It is also known from DE 195 25 291, by means of appropriate means equipped test vehicles to record dynamic traffic data and to a central control center.

In addition, the dynamic parameters around weather information and Temporary restrictions, such as construction sites, can be added.

From the static and dynamic data collected in the control center in a known manner, using fundamental diagrams to forecast the coming Derive traffic situation in each segment, which is the basis for route guidance of vehicles form.

However, the prognosis obtained in this way is due to the lack that through a determined route guidance along a plurality of segments using the in the Control center available actual and forecast traffic data a needed Travel time can be determined, but the targeted vehicle remains at the specified Routing bound even in the event of unforeseeable, disabling events.

In addition, any forecast based on fundamental data remains inaccurate, since principle-related current dynamic parameters are disregarded. This Effect is enhanced by the fact that analytically closed mathematical Relationships between the fundamental data are very complex and therefore very are complex in processing.

The invention is therefore based on the object of a method of the generic type Specify the type that can take into account current dynamic parameters and is still manageable with simple computing means. It's not just supposed to for planning travel routes and guiding vehicles along planned routes Driving routes are suitable, but also for forecasting activities such as Traffic route planning or to evaluate planned routes (determining the estimated travel time) can be used.

According to the invention, this object is achieved with the means of claim 1. Advantageous embodiments of the invention are in claims 2 to 15 described.

Current dynamic data (especially the data in one Section currently possible or average speed) preferably obtained by measurements which are arranged in vehicles Measuring devices are included, the vehicles in traffic swim along (floating cars). It can also include data from the street installed measuring devices can be used.

Advantageously, this ensures that the traffic data is up to date, and the resulting route guidance of vehicles is faster than the actual one Customizable traffic data. That is, the response time from the occurrence of a traffic restricting event through its detection to distribution of route guidance information to vehicles that focus on the Moving traffic restrictions becomes minimal.

In addition, the processing of highly complex mathematical is omitted Simulation calculations with predefinable models based on the so-called Fundamentals based essentially on assumptions regarding structural, ie are based on static parameters that sustainably increase the response time. Much more is the preferred measurement on the moving object not only the specific location of the known restrictive event, but by multiple measurements with various vehicles equipped with measuring devices is inside the same traffic route also an obvious cause of Traffic restriction derivable. For example, one of the two facts immediate response to the traffic restricting event by one of the Traffic guidance taking into account traffic restrictions possible. It realistic assessments of planned routes can be carried out in particular make relatively reliable statements about the expected travel time, where extrapolated data and / or from a current traffic data Experience database data used can be used as input data can. The inventive method can be very well in the sense of Use simulation models, for example, to forecast traffic Create traffic route planning.

The invention is explained in more detail below on the basis of exemplary embodiments. The invention is based on one held in a central control center digital map, in which static and dynamic for the recorded traffic routes Parameters are stored. The static parameters at least include structural features of the individual traffic routes, such as number of lanes, Uphill / downhill and road type. It is characteristic of the invention that Route data determined based on the relevant dynamic parameters the dynamic parameters are used only once to specify start values derived from the structural features and henceforth with secure availability dynamic data continuously to the real ones regardless of static parameters Ratios of the respective route sections of the traffic routes are adjusted.

The dynamic parameters include at least a conductance and a load function the associated traffic route (i.e. the specific one considered Road section). The conductance represents a measure of the possible Speed in the chosen traffic route and is preferably from the average speed of the vehicles formed in the respective route section. Alternative forms of representation, such as average time traveled, time per km or the like of course within the scope of the revelation.

The load, for example the number of vehicles, on the considered Section of a traffic route becomes the possible speed influence. The dependence of the conductance on the load is shown by a Load function shown. As a rule, the conductance will decrease with increasing load. Both the conductance and the load have upper limits that are limited by the maximum possible or allowed speed and by the capacity limit that is limited, for example, by the number of lanes. The Load function is the essential classification feature of a traffic route for example as part of the route guidance of vehicles according to the invention, since they do that for a particular traffic route from the current load characteristic relevant to decision determined. The load data can from current information as well as from extrapolated or simulated data or come from an experience database, so that in particular forecasts about future traffic developments are possible. There can also be future ones Determine guide values, e.g. Travel times for a certain planned route forecast. In contrast to conventional route determination methods, in which are purely descriptive parameters for characterizing sections of the route are used, which remain unchanged within a temporal update interval remain, one always achieves dynamic by using a load function permanent description of the traffic characteristics.

In the practical version, the load function is expediently as Proximity function described. For this purpose, the route sections in the digital map in a computer in the central control center the parameters of the Proximity function assigned. All can be used to parameterize the load function relevant interpolation methods such as straight line or polynomial representation, spline method u. a. be used.

The main advantage of the method according to the invention is that the Load function not due to formal structural features such as B. the characteristic "Autobahn" is determined. The load function is done in a first approach Standard specifications, for example for highways, country roads, etc. defined. Depending on the availability of qualified information, the load function however individually refined. The dynamic is therefore adjusted Parameters to the relevant conditions of the respective route section. Next other formal information such as Speed restrictions, downhill gradients or similar are primarily provided for to learn the actual load function preferably automatically. Every traffic route receives an individual load function "after the best Experience".

This load function is learned, for example, by using the Measuring equipment equipped vehicles that run along the respective Move traffic route, record data and to the central control center Send processing, and if necessary by additional stationary Measuring devices.

The high benefit of the invention is the example of a three-lane Highway section are explained. The load function is a set of parameters a relevant interpolation method. Because of the structural Features (three lanes, no speed limit) becomes a standard parameter set given that already contain a certain amount of pre-differentiation can. Based on measurement data both on the number of vehicles and on If necessary, the speed becomes a after a sufficient static check Fine-tuned these parameters. In any traffic situation, the Load function based on a few measured data conclusions about the traffic situation in this section of the route.

If this section of the route is carried by a construction site onto a two-lane roadway Reduced speed limit, the measured values are in very quickly Contradiction to the assumed load function. Is the construction site in the headquarters known, the parameters of the load function can be implemented manually accordingly become. However, the permanent plausibility check with the measured values leads to The meaning of a self-learning system with sufficiently large deviations without manual input quickly to a correction of the load function, so that the current properties of the road section are correctly reproduced without that additional attributes such as "construction site" or similar would have to be maintained manually because the Compatibility check of the current traffic data with the current dynamic Parameters in the event of sufficiently large deviations from the corresponding adjustments would lead.

For the guidance of vehicles it is also provided that the decision or Recommendation on which traffic routes each vehicle is to reach its destination, is made solely on the basis of the current dynamic parameters.

If, for example, on a traffic route that is a section of a motorway, the opposite all vehicles with measuring devices in one Section without parking is significantly reduced in speed it is likely that a traffic jam has formed or is in formation. This can be assumed with a high degree of certainty, if also permanently installed Measuring devices in the respective route section a very low or even zero Confirm the average speed. Subsequent targeted Vehicles that have not yet entered this traffic route can use this route Event already caused to bypass this section. The time of perception of the event is advantageously synchronous for the occurrence of the event.

In an embodiment of the invention it is provided that the dynamic parameters in definable closed geographic areas manually or also are automatically scaled.

It is advantageously achieved that significant changes in the load function even before the occurrence or in sync with the occurrence of an event expected values are adaptable and thus when navigating vehicles the total distance can be taken into account without the learning process must be waited for.

This scaling can be used particularly advantageously in the case of prematurely known ones Events such as the construction of construction sites on individual traffic routes and in the event of traffic-relevant weather changes for areas of Traffic routes. Otherwise the scaling e.g. by day of the week, time of day and Weather differentiated.

It can be advantageous to learn those learned during an ongoing event dynamic parameters as a scenario in an event-related database of Store experience data in the central control center and when a comparable event for the same affected traffic routes as current load dynamic parameters (default settings). Such events are considered especially large events such as trade fairs, the start or end of school holidays or typical regional weather influences.

In addition, this feature of the invention is advantageous in traffic simulation and traffic planning applicable. For example, the effect of increasing the Number of lanes for a definable traffic route can be directly simulated.

According to a further feature of the invention, it is provided, generally or at least in the case of repeated temporary limited traffic flow on one Traffic route alternative traffic routes to bypass the respective traffic route to be determined and included in an alternative parameter that corresponds to the respective thus in particular the traffic route in the area restricted in its flow of traffic digital map. The alternative parameter expediently includes in terms of a parameter list, at least the number of alternative traffic routes as well as their quality and length (if necessary, detour length).

The number or existence of vehicles is more possible for route guidance Alternative routes is a often decisive evaluation feature for one Traffic route.

There are only a few sensible alternatives for many routes, many of which are always lead the same traffic routes. These critical points can be, for example River bridges or tunnels. For example, since the entire river crossing traffic of a region under consideration leads over only a few bridges the traffic situation on these bridges is crucial for the assessment of very many Routes. The evaluation of the possible and sensible alternatives to one Traffic route is expressed by the alternative parameter. The meaning this alternative parameter is to be explained using an exemplary embodiment.

In a simple application, the alternative parameter becomes the same for one Alternative necessary detour set. So the further the detour via Alternative route is, the larger the alternative parameter becomes. This measure can by other factors, such as the number of alternative routes or the capacity of the Alternative routes can be further refined. The alternative parameter ultimately evaluates the traffic route according to whether it is worth looking for an alternative route. Each the higher the alternative parameters, the less the effort for the search for an alternative.

The alternative parameter can be an average over many possible routes represent. These can be, for example, through experience or through suitable ones Simulations are generated. The advantage in using this Classification characteristic lies in the drastic reduction of the necessary Computing effort to determine alternative routes.

Another option for generating this parameter is an evaluation the topology of the underlying transport network map. With the help of relevant Processes are used to identify coherent, well-connected large areas. The These large areas are bordered by only a few traffic connections traverses. These access roads form the critical routes that run through one distinguish high alternative parameters. Examples of this are large cities, however also regional agglomerations.

In a further embodiment of the invention, there are successive Traffic routes on a route with a low degree of branching Combine traffic route complexes and route guidance as a single one Traffic route to be taken into account and depending on the degree of branching of the Traffic flow at nodes of successive traffic routes each of the assign a complexity parameter to successive traffic routes.

So a long stretch of highway over the "flat land" with few, usually little traffic leading up and downs, for example due to a low Complexity parameters described. Route sections with consistently low Complexity parameters can therefore lead to a higher-level route section can be summarized: It goes essentially "straight ahead", and almost everything Driving in at one end must come out at the other end.

This classification feature can be advantageous particularly when controlling the internal computing effort, in controlling information collection, in particular the traffic situation recording, but also in the representation of the relevant information.

The method according to the invention is advantageous in the context of an offboard route guidance system applied, in which a route recommendation from a control center is determined as route data, the decision about which Traffic routes the vehicle should be guided as part of the route recommendation, primarily or exclusively on the basis of the relevant dynamic parameters is hit. The corresponding route guidance information can, for example are transmitted to the vehicle by means of cellular mobile radio. The procedure can but also find advantageous use in an onboard route guidance system for whom the route planning and the output of route guidance information are self-sufficient in Vehicle. With such a system, it may be advisable to use before or to transmit the planned route to the headquarters during a trip, according to the Assess the current relevant dynamic parameters and change them if necessary and transfer the result back to the vehicle, then the Carrying out route guidance autonomously. When planning a route, the evaluation alternative route suggestions expediently based on the complexity parameter and if necessary, further criteria, in particular travel time and distance traveled.

Claims (15)

1. Method of determining itinerary data, in particular in the context of the destination guidance of a vehicle, using a digital map which is kept in a central control centre and in which statistical and dynamic parameters are stored in sections for the detected traffic routes, the statistical parameters comprising at least structural features of the respective traffic route, characterised in that the dynamic parameters comprise at least one conductivity and a load function of the respective section of the traffic route, the conductivity characterising a measurement of the possible speed in the selected traffic route and the load function characterising the dependency of the conductivity on the load, in that the dynamic parameters are derived in one go in order to specify start values from the structural features, and from then on if there is reliable availability of dynamic data, independently of statistical parameters, are continuously adapted to the real conditions of the respective sections of the traffic routes, and in that the itinerary data are determined on the basis of the relevant dynamic parameters.
2. Method according to claim 1, characterised in that the conductivity is formed from the average speed of the vehicles in the respective section of the traffic route and in that the load function describes the dependency of the conductivity on the number of vehicles on the respective section.
3. Method according to claim 1 or 2, characterised in that the load function is described as an approximation function, in particular in polynomial representation, and the parameters of the approximation function are allocated to each section.
4. Method according to one of claims 1 to 3, characterised in that the detected itinerary data contain a route recommendation and in that the decision as to along which traffic routes the vehicle is guided to its destination in the context of the route recommendation is made according to priority or solely on the basis of the relevant dynamic parameters.
5. Method according to one of claims 1 to 4, characterised in that as relevant dynamic parameters, the respectively current dynamic parameters are applied.
6. Method according to one of claims 1 to 5, characterised in that the dynamic parameters are scaled manually or automatically relating to events in specifiable, closed geographical regions.
7. Method according to claim 6, characterised in that the scaling, which may be pre-differentiated according to the day of the week, time of day and/or weather conditions may, in the case of traffic-relevant weather changes and events known in advance, in particular at the start of public holidays or in the setting up of building sites and large institutions, is effected with the aid of standard stipulations from an experience database.
8. Method according to one of claims 4 to 7, characterised in that alternative traffic routes are determined in order to bypass the respective traffic route and find entry into an alternative parameter which is allocated to the respective traffic route in the digital map.
9. Method according to claim 8, characterised in that the alternative parameter comprises according to a parameter list at least the number of alternative traffic routes as well as their quality and length.
10. Method according to claim 8 or 9, characterised in that the alternative parameter is determined at least for traffic routes whose traffic flow has repeatedly been subject to temporary restrictions.
11. Method according to one of claims 4 to 10, characterised in that consecutive traffic routes with a low degree of branching are grouped into traffic route complexes and are taken into account for destination guidance as one traffic route and in that, depending on the traffic route and the degree of branching of the traffic flow at junctions of consecutive traffic routes, a complexity parameter is allocated to each of the consecutive traffic routes.
12. Method according to claim 11, characterised in that in route planning alternative route suggestions are evaluated by means of the complexity parameter and optionally further criteria, in particular travel time and travel distance.
13. Method according to one of claims 1 to 12, characterised in that the adaptation of dynamic parameters is effected according to a self-learning system, actual traffic data being surveyed, the compatibility of these data with the actual dynamic parameters being tested, and in the case of sufficiently strong deviations the dynamic parameters being adapted.
14. Method according to claim 13, characterised in that the surveying of at least some of the traffic data, in particular of the current average speed in a section, is effected by vehicles going with the traffic flow.
15. Method according to one of claims 1 to 14, characterised in that by means of the dynamic parameters, traffic prognoses are derived for traffic route planning or travel times for planned itineraries are prognosticated, and from load data which are extrapolated or taken from an experience database, future conductivity values are determined via the respective load function.