WO2010040591A1

WO2010040591A1 - Method for determining a route and device therefor

Info

Publication number: WO2010040591A1
Application number: PCT/EP2009/060543
Authority: WO
Inventors: Stephan Buch; Marcus Schneider
Original assignee: Robert Bosch Gmbh
Priority date: 2008-10-10
Filing date: 2009-08-14
Publication date: 2010-04-15
Also published as: DE102008042732A1

Abstract

The invention relates to a method for determining a route from a starting point to a destination point in a navigation system through optimization with respect to an optimization criterion, wherein the optimization criterion consists in a minimization of decision points lying on the route. The invention has the advantage that route guidance becomes easier to understand and more comprehensible for a user and possible sources of error in following the route are reduced to a minimum.

Description

title

Method for determining a route and device therefor

State of the art

The invention is based on a method and a device according to the preamble of the independent claims.

Current navigation systems allow the determination of routes that represent an optimum in terms of certain criteria, such as the shortest travel time or route. In addition, certain route sections may be excluded from route determination, such as tunnels, toll roads or ferries. Furthermore, due to the consideration of digitally coded traffic reports transmitted via broadcasting, for example according to ISO 14819, a respective current traffic situation, that is to say, in particular, current traffic disruptions, can be taken into account in the route determination.

JP 2006 226 786 A describes a navigation system which determines a driving route from a starting point to a destination point and guides a driver along this route to the destination, the driving route being determined in such a way that right-turn procedures for following the route are avoided as far as possible. This is based on the left-hand traffic common in Japan, so that right-turn operations, in particular due to the required crossing of an oncoming lane, present a danger potential and require increased attention of the vehicle driver. Right turn operations are thereby bypassed by a plurality of consecutive left turn events if the detour resulting from this work does not exceed a certain length. Purpose and advantages of the invention

It is an object of the invention to provide an improved route determination for a navigation system, which makes it easier for a user of the navigation system to follow the route.

This object is achieved in that in the route determination, the number of decision points contained in the route, in particular branches, junctions, intersections, roundabouts and the like, where the user must make a decision on a drive on, and thus the possible sources of error for the user to follow the route to the minimum.

For this purpose, road map data, on the basis of which the route is determined from a start to a user-specified destination, are assigned traffic nodes, in particular branches, junctions, intersections, roundabouts and the like, weights. The route is determined on the basis of these weights assigned to the traffic nodes in the sense of minimizing the total costs of the route as the sum of the weights of the traffic nodes contained therein. If all nodes have been assigned the same weights, a route is thus determined which contains a minimum of traffic nodes.

Preferably, the weights assigned to the traffic nodes vary in

Dependence of a complexity of traffic nodes. For example, simple intersections or branches are assigned lower weights than intersections or roundabouts or the like. The complexity and thus the height of the weight can correlate directly with the number of road sections opening into a traffic junction. Furthermore, the

Complexity with the clarity of the traffic nodes from the point of view of the traffic node approaching vehicle driver correlate, so that, for example, a simple intersection with two-lanes opening Less weight is given to road sections than, for example, a roundabout that is not or only partially overlooked due to development or planting at its center or due to its extension.

Furthermore, the traffic node can also be advantageous for various

Driving maneuvers are assigned different weights. Thus, a straight-ahead driving over an intersection is occupied with a lower weight than a Rechtsabbiegevorgang and this again with a lower weight than a left turn, in which the oncoming traffic would have to be crossed. These mentioned and also further influences on the complexity of a

Traffic nodes advantageously overlap additively or multiplicatively to a resulting total weight for a traffic node.

Advantageously, the route determination does not take place exclusively in the sense of minimizing the sum of the node weights of the traffic junctions involved, but with a criterion mix, that is to say under a boundary condition, such as in particular a shortest possible total travel distance, total energy consumption or total travel time. Thus, a route is determined which as a result contains a small number of nodes and thus decision points for the driver and at the same time a short one

Driving distance, low fuel consumption or a short driving time required. The weighting of the criteria to be taken into account can advantageously be predetermined by the user.

drawings

Embodiments of the invention are illustrated in the figures and are explained in more detail below.

Show it - A -

Figure 1 is a block diagram of a vehicle navigation system as an example of an arrangement for carrying out the method according to the invention and

Figure 2 shows a section of a road network to illustrate the operation of the invention.

Description of the embodiments

In FIG. 1, the reference numeral 1 designates the arrangement according to the invention for carrying out the method according to the invention, here without limiting the generality of the invention using the example of a navigation system 1 for permanent or at least temporary use in a motor vehicle, ie a vehicle navigation system.

The navigation device 1 comprises, in a manner known per se, means 11 for self-locating and thus for determining a current vehicle location, for example a receiver for GPS satellite positioning signals, preferably additionally inertial sensors and the like, whereby the respective current location is determined from a combination of these signals. Over a

Operating device 12, which preferably has control elements in the form of push buttons, touch screen or the like, can be entered by the user a destination. As a result, a route calculation module 101, which is preferably a software module that is processed by a computer of a central controller 10 of the navigation system 1, calculates a route from the current vehicle location to the entered destination via a traffic route network represented by map data 14 stored in a mass memory 14 becomes.

The map data 14 includes elements, namely, in particular, edges that

Traffic routes a traffic route network, in the case of a navigation system for road vehicles road sections, represent. These are designated in the section of a road map shown in Figure 2 with Sl, S2, S3 and S4. These edges are assigned edge weights, here for example length values, which indicate how long a respective traffic route or traffic route section is. These edges Sl,..., S4 are linked to one another via nodes which correspond to real traffic hubs, in particular branches, junctions, intersections, roundabouts, motorway exits or exits and the like in the real traffic route network. In FIG. 2, these are the nodes K1 and K2. These nodes are also assigned weights in the map data 14.

In a preferred embodiment, the weights assigned to the nodes correspond to an assumed complexity of the nodes. This means that, for example, simple branches or junctions are assigned a lower weight, whereas more complex nodes, such as intersections or roundabouts, have a higher weight. The complexity corresponds, for example, to the number of edges opening in the node, ie traffic route sections. Furthermore, the complexity of the nodes corresponds, for example, with their clarity from the perspective of a vehicle driver who approaches such a transport node with his vehicle. Here, for example, a roundabout with development in the center of a higher complexity than, for example, a relatively clear junction. Furthermore, for example, an intersection with multi-lane inaugurated roads may have a higher complexity than an intersection with two-lane inaugurating roads.

In a further preferred embodiment, the weights associated with a traffic node advantageously also vary as a function of a passage direction through the traffic information. For example, a straight-line travel across an intersection is associated with a lower weight than a right-turn at that intersection, and this, in turn, is less than a left-turn at that intersection.

On the basis of this map data 14, a route calculation is carried out from a start to a user input via the operating device 12 Destination in route calculation module 101 according to a known route calculation algorithm, such as Ford-Moore or Dijkstra. In a simplest embodiment, this calculation could take place exclusively in the sense of minimizing the total costs of the routes as the sum of the weights of the node weights contained in the route. The result of

Route calculation would thus be a route from the starting location to the entered destination, which, as far as all nodes are assigned the same weights, comprises a minimum of nodes and thus traffic nodes. From the point of view of the user or vehicle driver, such a route would have the advantage that decisions necessary at decision points on a further journey via one of at least two possible further roads are reduced to a minimum.

In a preferred embodiment, the nodes of the traffic route network weights are assigned, which also take into account the nature of the nodes. In case of

For example, FIG. 2 may assign to the node K1 a weight with the value "3", the node K2 a weight with the value "8". For example, these values may be as follows. Each node receives a weight, the amount of which depends on the number of entering road sections. Kl is an intersection with three subsequent road sections Sl,

S2 and S4 and thus obtains the weight "3." The roundabout K2 comprises four intersecting road sections S2, S3 and two road sections not designated in the Figure 2, resulting in a weight of "4". Since a roundabout is or can be confusing, this value is doubled here, for example, resulting in the node weight "8" for the

Roundabout K2. These assumed values and the calculation proposed here are expressly an example for clarification. Other calculations and resulting values of the edge nodes may appear more practical and are within the scope of the present invention. AIs possible route alternatives would result in calculation over the map detail shown in Figure 2, the routes from the starting point P to the destination point Z as follows.

1. Alternative P -> Cl -> Z, sum of the account weights = 3

2. Alternative P -> Kl -> K2 -> Z, sum of node weights = 3 + 8 = 11.

The routes to be traveled are cheating for the two alternatives assuming edge weights as follows

Sl: 1

S2: 1

S3: 3

S4: 6

1. Alternative Sl -> S4 Sum edge weights = 1 + 6 = 7

2. Alternative Sl -> S2 -> S3 sum of edge weights = 1 + 1 + 3 = 5

Thus, although alternative 2 via the junction Kl and the roundabout K2 on a shorter route, but a higher overall complexity due to two included nodes compared to a node in the first alternative on. Taking only the sum of the node weights into account, the alternative 1 P -> Kl -> Z would therefore be used as the basis for the route guidance.

In a preferred embodiment, the minimization of the total costs does not take place exclusively via the nodes, but additionally via the edge weights. As a result, a route is thus calculated which comprises a minimum of nodes or decision points under the boundary condition of a simultaneously short route length from the start to the destination. The measure of

Weighting of the criteria, in this case number of knots and short route at the same time, can be achieved by multiplying the weights of both the edge and the edge Nodal weights with corresponding weighting factors of, for example, 40% for the node and 60% for the edge weights are given.

With the same weighting of the criteria, low total complexity of the route, ie low overall node weight and short total distance, ie low

Total edge weight, resulting for the two alternatives following conditions.

1. Alternative P via Sl -> Kl via S4 -> Z 2. Alternative P via Sl -> Kl via S2 -> K2 via S3 -> Z

and thus total costs of

1. Alternative 1 (Sl) + 3 (Kl) + 6 (S4) = 10 2. Alternative 1 (Sl) + 3 (Kl) + 1 (S2) + 8 (K2) + 3 (S3) = 16

Here, too, alternative 2 has significantly higher overall costs than alternative 1, so that the alternative is based on the subsequent route calculation.

The thus calculated route is stored in a route memory 18 and based on a subsequent route guidance, which is determined in the course of the movement of the vehicle whose current location and aligned with the route and, if necessary, guidance instructions for following the route generated and, for example, as synthesized speech over a Output device 16 are output acoustically. Alternatively or additionally, the route can also be displayed, for example, on a display 19 in a map representation.

In the weighting of traffic junctions may also include other considerations, such as - the type of crossing (roundabout, star junction with several situations eg "half right / far right", traffic lights (late determination in straight / right or left turn, possibly multi-lane), T-junction, Y-junction, etc.), where a multi-lane traffic light crossing certainly receives a higher complexity weighting than a simple "right or left" -

Crossing (T-junction).

- Type of road (for example, motorway, main road, country road, inner-city priority road, inner-city residential streets, ...). Whereby an intersection requiring turning along a priority road e.g. a lower one

Complexity rating has, as an inner-city residential street with closely spaced turns, where private entrances are often difficult to distinguish from "real" streets.

Another weighting option for an intersection is the

Consider the impact of a false turn. An intersection that leads to a significantly longer total distance, or into a road situation with complex intersection situations in case of a wrong turn (for example straight driving instead of turning right) or turning only after a long wrong drive is accordingly highly weighted with regard to its complexity. This consideration may e.g. be carried out by the fact that the algorithm assumes Fehlfabbiegunen at particularly error-prone intersections / roundabouts, etc., and then determines a route calculation to the destination to determine the degree of difficulty. This is then suitably integrated into the degree of complexity of the crossing.

It is advantageous to determine the weighting of the crossings empirically.

Claims

claims:

A method of determining a route from a starting point to a destination point in a navigation system by optimizing for a

Optimization criterion, characterized in that the optimization criterion consists in minimizing decision points lying on the route.

2. The method according to claim 1, characterized in that the decision points are assigned weights, wherein for optimization with respect to the optimization criterion, the sum of the weights of the decision points lying on the route is minimized.

3. The method according to any one of the preceding claims, characterized in that decision points traffic nodes of a traffic route network correspond, which traffic route nodes are characterized in that from a current location on a traffic route from at least two options for further movement within the

Traffic network exist.

4. The method according to any one of the preceding claims, characterized in that different weights are assigned to different types of decision points, wherein for optimization with respect to the optimization criterion, the sum of the weights of the decision points lying on the route is minimized.

5. The method according to any one of the preceding claims, characterized in that the route is carried out by optimization with respect to an additional, second optimization criterion, such as in particular shortest route, fastest route or most low-cost route, wherein the two optimization criteria are weighted each other.

6. Arrangement with a computer for determining a route according to a method according to one of the preceding claims.