WO2009076925A1

WO2009076925A1 - Method for operating a navigation system in a vehicle

Info

Publication number: WO2009076925A1
Application number: PCT/DE2008/001970
Authority: WO
Inventors: Oliver Michael
Original assignee: Navigon Ag
Priority date: 2007-12-19
Filing date: 2008-11-28
Publication date: 2009-06-25
Also published as: DE102007061706A1; EP2223044A1

Abstract

The invention relates to a method for operating a navigation system in a vehicle, said navigation system comprising - an input device which can be used to input operator commands and/or locations, particularly starting points and/or destinations, - a road network database, - a position-finding unit, which determines the current position from position signals, particularly satellite signals or position sensor signals, - a route calculation unit for calculating routes taking account of the locations and the road network database, wherein the routes respectively lead from the starting point, particularly from the current position, to the destination, - at least one routing unit, which calculates manoeuvre instructions for following the journey distance along the active route, - at least one visual and/or audible output device, for the purpose of outputting the manoeuvre instruction, having the following method steps: a) the current position is found; b) a significant difference between the current position and the active route is found; c) at least one portion of the previously active route is buffer-stored as an inactive route in a route buffer-store.

Description

November 28, 2008

Method for operating a navigation system in a vehicle

The invention relates to a method for operating a navigation system in a vehicle according to the preamble of claim 1.

Known navigation systems, for example mobile or permanently installed in a vehicle navigation devices, serve to guide the user along a precalculated route from a starting point to a destination point. For this purpose, a Wegnetzda- tenbank is present in the navigation device, in which the corresponding geographical area is described digitally coded. By means of a route calculation unit, a route from the starting point to the destination point is calculated taking into account the location information input by the user and the digital map described in the road network database. In particular, this route may be an ordered list of links from the starting point to the destination point.

By means of a position detection unit, the navigation system constantly determines the current position. For this purpose, the position detection unit uses the position signals of suitable positioning systems, for example satellite signals of the GPS satellites or position sensor signals of position sensors installed in the vehicle. tet. Depending on the current position, maneuvering instructions are calculated by a route guidance unit, which enable the driver to follow the route along the active route. The output, in particular of the maneuvering instructions, takes place by means of an optical and / or acoustic output device, in particular by optical display on a display or by acoustic announcement on a loudspeaker. If it is determined in the known navigation systems during route guidance that the vehicle has left the pre-calculated active route, the calculation of a new route is triggered on the basis of the current position and the previously active (old) route is discarded. Then the route guidance is continued with the newly calculated route.

This rerouting of known navigation systems is associated with considerable disadvantages. For example, if the determination of leaving the active route is based on an inaccurate position determination, for example due to lack of satellite signals, a new route is calculated even though the new vehicle has not left the route at all. But even when actually leaving the active route, the known rerouting is fraught with weaknesses. The driver often corrects his driving error and reaches the old route again after a very short detour, so that discarding this route and recalculating a new route itself is unnecessary.

The recalculation of a new route is also disadvantageous because, due to special boundary conditions and special optimization criteria in the recalculation of the route, the new route may very strongly deviate from the old route despite a very small deviation from the previously valid route differs. For example, if the driver leaves the freeway briefly to take a break at a car yard, the recalculation of the route that is triggered by it may result in the driver not returning to the freeway and arriving at the destination along the old route, but the new route along smaller country roads leads to the destination point. Such sudden deviations from the originally calculated route due to a route recalculation are irritating to the user and altogether undesirable.

The complete route calculation is also dependent on the length of the remaining distance and the route characteristic, also computationally intensive and can therefore take a relatively long time, depending on the hardware used. During route re-calculation, the user may not be able to route the route for a longer period.

Based on this prior art, it is therefore an object of the present invention to propose a new method for operating a navigation system, which avoids these disadvantages of the known rerouting.

This object is achieved by a method according to the teaching of claim 1.

Advantageous embodiments of the invention are the subject of the dependent claims.

The method according to the invention is based on the fundamental idea that, when a deviation between the current position and the previously active route is detected, the rejection of the previous route and simultaneous calculation of a new route is often unnecessary because the driver approaches the original route in a timely manner. For example, if the driver accidentally deviated from the route, he often returns to the original route quickly through a spontaneous maneuver, without the need to recalculate a new route. The same applies if the driver consciously leaves the route for a break. Again, a recalculation of the route is unnecessary because the driver starts the original route after the break again. To enter the Cases in which the use of an already calculated route could still be useful to avoid a complete recalculation, the invention proposes that upon detection of a significant deviation between the current position and the active route, the previously active route is no longer completely discarded and thus the information contained in the previously active route is lost. Instead, it is proposed according to the invention to temporarily store the previously active route in a route buffer, so that the information of the previously used route can optionally be accessed again at a later time if necessary. A route temporarily stored in the route buffer is referred to below as an inactive route. Due to the temporary storage of the information contained in the inactive routes, it can be used again very quickly if required. In many cases, this can save considerable computing power and the response times of the navigation system can be shortened.

Which processes take place in parallel or after the intermediate storage of the inactive route in the route buffer on the navigation system, is basically arbitrary. In order to be able to continue the route guidance as quickly as possible when the vehicle no longer returns to the previously active route, a new route should be recalculated on the basis of the current position during or shortly after the temporary storage of the inactive route. This newly calculated route can then be interpreted as a new active route by the route guidance unit and corresponding maneuvering instructions can be derived therefrom.

To cover cases in which the user has left the old, now inactive route unconsciously unconsciously, it is particularly advantageous if the user after the caching of the inactive route or after triggering the recalculation of a new route to a choice the output device is output, in particular displayed. In this selection option, the user then has the option of immediately specifying the cached inactive route again as an active route, so that the route guidance unit then calculates maneuvering instructions for following the old route.

In order to easily return the driver to the old route stored as an inactive route, so that this old route can then be used again as an active route, it is often necessary for the driver to drive back a bit until he returns to the old route back place. In order to make it easier for the driver to return to the old route, an intermediate route can be calculated by the route calculation unit, so that the driver is guided from his current position to the old route.

In most cases, it is not necessary to store the complete route from the starting point to the destination point as an inactive route since the driver has already traveled a certain distance on this route in many cases. In order to save storage space, it may therefore be particularly advantageous if, during buffering, only the remaining route from the position of leaving the active route to the destination point in the route buffer is temporarily stored as a new inactive route.

In order to enable optimal route guidance, if the driver returns to the old route after a for example unconscious leaving the active route by a corresponding steering maneuver, the current position can be parallel to the other processing processes in the navigation system after leaving the active route the elements of the inactive route stored in the route buffer are compared. If the navigation system then determines a match of the current position with an element of the inactive route, this inactive route can again be called active route and route guidance based on this route.

Problems may cause activation of the inactive route stored in the route buffer as a new route if an element of the inactive route coincides with the current position but the corresponding road section is not being driven in the correct direction of travel. If the driver has turned, for example, on a major arterial road, it can often happen that a turning maneuver to follow the old route due to the road conditions is not possible. To avoid such situations, in addition to checking the current position with the elements of the inactive route, the current direction of travel can also be compared with the respectively planned direction of travel on the elements of the inactive route. Only if the planned direction of travel coincides with the current direction of travel on the already matching element of the inactive route, the inactive route is activated as a new route.

As already mentioned, the remaining route from the position of the exit of the active route to the destination point can be temporarily stored as an inactive route in the route buffer in order to save storage space. If, however, the caching of the inactive route is restricted to this rest route, problems can arise in particular in the above-described check of the correspondence of the current position with an element of the inactive route, since the inactive route no longer contains all parts originally from the route calculation unit calculated route includes. If, for example, the driver left the old route unconsciously and drove back a short distance in the direction of the starting point, entering the old route would simply not be recognized as an inactive route if the rest of the route were merely stored in the old route Position of leaving the route is because this part of the originally calculated route is not stored in the route buffer. stores is. To avoid such situations, it is therefore particularly advantageous if, in addition to the remaining route, a subsection of the already traveled route is also stored in the route buffer memory. This additional subsection runs starting from the position of leaving the active route backwards a little way in the direction of the starting point. The length of the subsection can be preconfigured by appropriate configuration and, for example, correspond to a specific length dimension or a specific relative length dimension as a function of the length of the original route.

The inventive method improves the routing when leaving the originally active route. A further mitigation of this problem can be achieved by using route trees. Thereafter, a route tree is calculated for each active route. This route tree contains, in addition to the active route, alternative route sections branching off from the active route.

If the driver then leaves the active route and if this deviation is detected by the navigation system, it is first checked before the initiation of a rerouting whether the current position coincides with an element of the alternative route sections of the route tree. As far as this is the case, a rerouting can be spared because the driver is then returned along the precalculated alternative route section to the active route in order to continue the journey along the active route.

The calculation of route trees can be time-intensive, so that in cases where a route tree can not be used immediately further, the route tree according to the basic idea according to the invention should again not simply be discarded. Rather, it is advantageous that, upon detection of a significant deviation of the current position on the one hand and the active route or the alternative route sections of the active route tree of another. On the other hand, the active route tree is stored as an inactive route tree in a route tree buffer.

During the continuation of the journey, the current position can then be compared in each case with the elements of the elements of the inactive route trees stored in the route tree buffer. If a match is found, the recalculation of a new route tree can be avoided by activating an inactive route tree stored in the route buffer.

In the basic form of the invention it is sufficient if in each case an inactive route or an inactive route tree is temporarily stored in the route buffer or in the route tree buffer. However, when driving along a route it can often happen that the driver leaves the route several times and then a recalculation of routes is triggered and carried out. In order to be able to use the information of these newly calculated routes in the longer term, it is therefore particularly advantageous if several inactive routes or several inactive route trees are buffered next to one another in the route buffer or in the route tree buffer.

Depending on the number of inactive routes or inactive route trees stored side by side in the route buffer or in the route tree buffer, relatively large amounts of data can accumulate, which must be stored in the route buffer or in the route tree buffer. Since, however, only limited storage space is available on a regular basis, older inactive routes or older inactive route trees must be deleted when a new inactive route or a new inactive route tree and its additional storage in the cache are added. However, the information value of the various inactive routes or inactive route trees is regularly very different. To prevent inactive routes or inactive routes Therefore, before the deletion of an inactive route or an inactive route tree, a comparison analysis should be carried out, the deletion then being carried out as a function of the comparison result of the comparative analysis or the newly added route or the newly added route tree is not recorded in the inactive route or route tree memory, because the comparison results of the comparison analysis with the at least one stored route or the at least one stored route trees results in the newly added route or the newly added route tree have a lower information content than the stored ones.

Within the framework of the comparative analysis, the different inactive routes can be evaluated, for example, according to which travel time or which route has already been covered on the various routes. For routes with a very short travel time or very short driving distance should regularly have a much lower information value than routes with already traveled long travel time or already covered long driving distance.

As a further evaluation criterion for comparing the different inactive routes, it makes sense to evaluate the travel time or the route since leaving the individual inactive routes. Because regularly the information value of routes that have been left for a long time or since a long journey, only be very low.

As a further comparison criterion, the evaluation of the travel time or the route to reach the actual destination, which may also be an intermediate destination, along the various inactive routes offers. In order to provide the driver with an easy overview of the inactive routes compared to the active route, the inactive routes stored in the buffer can be displayed on the optical output device. The inactive routes should be suitably characterized, for example by a different coloration compared to the active route, so that the driver can easily distinguish the inactive routes from the active route.

The display of the inactive route should be configurable, in particular deactivatable, in order to give the driver the opportunity to influence the representation of the inactive routes appropriately.

In many cases, leaving the active route is a deliberate decision of the driver, for example, to make a short break or a short refueling. In these cases, the vehicle is often turned off and the navigation system disconnected from the power supply. In order to prevent the inactive routes or inactive route trees temporarily stored in the route buffer or in the route tree buffer from being lost, the storage should take place in a non-volatile storage medium. Even if the nonvolatile storage medium is disconnected from the power supply, the routes or route trees stored in the nonvolatile storage medium are retained so that this information can be accessed directly after the vehicle is restarted.

It is particularly advantageous if the nonvolatile storage medium is write-protected and can only be overwritten after appropriate user release. In this way, unconscious data loss on information in the inactive routes or in the inactive route trees is excluded.

In the case of deliberately leaving the active route, it is particularly advantageous if the user has an opportunity to interact with the Navigation device, eg by operation or voice command, is provided, with which he interrupts the current route guidance, or if the previously active routes is left, suppresses a route re-calculation and / or breaks off. This triggers user-initiated storage of the active route. If it hits again on an element of the previously active, now inactive route, the route guidance is automatically continued. Alternatively, the abovementioned ability of the route calculation to the last active route could be made available to the user here. The method is particularly suitable for breaks, eg for refueling.

Various aspects of the method of the invention are illustrated schematically in the drawings and will be exemplified below.

Show it:

1 shows a schematically illustrated first traffic situation;

FIG. 2 shows a schematically illustrated second traffic situation; FIG.

FIG. 3 shows a map section with a planned route plotted therein; FIG.

FIG. 4 is an enlarged detail of the card according to FIG. 3; FIG.

FIG. 5 shows the map detail according to FIG. 4 after calculation of a new route; FIG.

Fig. 6 shows the schematic structure of a navigation system according to the invention.

1 shows the situation at an intersection 1, through which a route 2 calculated by a navigation system leads. At Junction 1 there is a fork in the road where the right arm of the fork must be negotiated to follow Route 2. In Fig. 2 it is shown, on soft route 3, the driver drives through the junction 1. It can be seen that the driver accidentally drove his left arm at the intersection 1 instead of the right arm of the fork and thus left the active route 2.

At position 4, the navigation system determines that the active route has been left. At this moment, the display device of the navigation system, for example, a screen, displays a message, for example, "Route is recalculated." Based on this message, the driver notices that he has departed from the predicted route and immediately turns right Passing a short connecting road, the vehicle then returns to the originally calculated route at position 4. At that time, the still running recalculation of a new route is interrupted and the old route temporarily stored in a route buffer is reactivated.

Figures 3 to 5 illustrate a situation in which the route is deliberately left by the driver, for example because of a break, and recalculation of the route is to be avoided.

FIG. 3 shows an overview map 6 with streets of the highest road category in France. On the overview map 6 a route 9 is drawn, which leads from a starting point 8 (in this case, Le Mans) to a destination point 10, in this case near Valenciennes). The route uses only roads of the highest category after reaching the interurban road network. If this route 9 is driven without any driving errors and driving interruptions, the entire route can be traveled on motorways of the highest category.

4 shows a section of the overview map 6 in the area of the Greater Paris. In the illustration according to FIG. 4, in addition to the streets 7 of the highest road category, roads 12 and 13 are also low. Rigerer street categories, which are urban and rural roads or multi-lane highways.

Next, the route 9 is located in the map section of FIG. 4. If the driver leaves the route at position 14, for example to take a break, this usually triggers the calculation of a new route.

5, the newly calculated after leaving the original route at the position 14 route 15 is shown by dashed lines. It can be seen that Route 15 now takes a different route in the Paris area, which passes much closer to the city center and is therefore more congested and less comfortable. For the user, the use of this new route 15 for further route guidance after briefly leaving the original route 9 at position 14 would be surprising and irritating.

To avoid these disadvantages, according to the inventive method, the original route 9 is stored as an inactive route when leaving the route 9 at the position 14 in the route buffer. After the break, this inactive route can then be reactivated either automatically or through appropriate user interaction and continue the journey along the originally planned for the trip motorway ring around Paris.

This activation of the original Route 9 will work even after leaving the route multiple times. Due to the length of the previously traveled route of approximately 200 km between Le Mans and Paris, the previously used route is treated with the highest priority when evaluating the inactive routes to be stored and possibly deleted, thus favoring routes created during rerouting and in the Cache stores remain. 6 shows the schematic structure of a navigation system for carrying out the method according to the invention. The navigation system 16 consists of various components that can be implemented in the form of hardware and / or software modules. Also, various functional modules can be implemented in a structural unit or as software modules.

Central control unit of the navigation system 16 is a control unit 17, which receives user input from the input unit 23, displays results on a screen 24 and can output acoustic signals via a speaker 25.

For route calculation, a position determination unit 21, e.g. a GPS module and / or a coupling location device that determines the current position of the vehicle. With the aid of the map database 19, a location element from the map database 19 is imaged by a localization unit 20 in a digital map.

A destination entered at the input unit 23 can be fed to the route calculation unit 18 together with the currently traveled map element, which uses the map database to calculate an optimal route and provide route guidance. The route guidance is presented to the user on the screen 24 and / or the loudspeaker 25.

During the passage of the route, the position determination unit 11 and the localization unit 20 are used to permanently or cyclically check whether the vehicle is still traveling on the current route determined by the route calculation unit.

If the localization unit 20 determines in connection with the control unit 17 that the active route has been left, the previously active route is stored as a route which is now inactive in a route buffer 12. Optionally, by the control unit 17 or a in FIG. 6 evaluation unit, not shown, whether sufficient space is still available in the route buffer memory 22 or whether an inactive route already stored in the route buffer memory 22 must be deleted after carrying out an appropriate evaluation.

Claims

claims

1 . Method for operating a navigation system in a vehicle, comprising - an input device, at which operator commands and / or location information, in particular starting points and / or destination points, can be entered,

- a route network database,

a position determination unit which determines the current position from position signals, in particular satellite signals or position sensor signals,

a route calculation unit for calculating routes taking into account the location information and the road network database, the routes leading from the starting point, in particular from the current position, to the destination point,

at least one route guidance unit which calculates maneuvering instructions for following the route along the active route,

- At least one optical and / or acoustic output device, for outputting the maneuvering instruction, comprising the following method steps: a) determination of the current position; b) determining a significant deviation between the current position and the active route; c) buffering at least part of the previously active route as an inactive route in a route buffer.

2. The method according to claim 1, characterized in that during or after the caching of the previously active route as an inactive route, a recalculation of a new route based on the current position is made.

3. The method of claim 1 or 2, characterized in that after the temporary storage of the previously active route as an inactive route or after triggering the recalculation of a new route a choice for selecting the inactive route as an active route for the further route guidance at the Output device is output.

4. The method according to claim 3, characterized in that when selecting an inactive route as an active route for the further route guidance, an intermediate route for the route guidance from the current position to an element of the inactive route is calculated and corresponding maneuvering instructions are output.

5. The method according to any one of claims 1 to 4, characterized in that in the intermediate storage of the inactive route at least the rest of the route from the position of leaving the active route to the destination in the route buffer is cached.

6. The method according to any one of claims 1 to 5, characterized in that after leaving the active route the current position is compared with the elements stored in the route buffer elements of the inactive route, wherein upon detection of the coincidence of the current position with an element of the inactive route the

Route guidance based on the inactive route continues as an active route.

7. The method according to claim 6, characterized in that upon determination of the coincidence of the current position with an element of the inactive route additionally the current direction is compared with the planned direction of travel along the element of the inactive route, wherein upon detection of the match and the current direction of travel with the planned direction of travel route guidance based on the inactive route is continued as an active route.

8. The method according to any one of claims 1 to 7, characterized in that in the intermediate storage of the inactive route next to the rest route and a subsection of the already traveled route in the route buffer is stored as part of the inactive route, said subsection at the position of Leaving the active route ends.

9. The method according to any one of claims 1 to 8, characterized in that for an active route, a route tree is calculated, wherein the route tree next to the active route more of the active

Route branching alternative route sections includes.

10. The method according to claim 9, characterized in that, upon determining a substantial deviation between the current position and the active route before calculating a new route, it is checked whether the current position coincides with an element of the alternative route sections of the route tree, wherein upon detection of a Match the route guidance based on the corresponding alternative route section continues as an active route.

1 1. A method according to claim 9 or 10, characterized in that upon detection of a significant deviation between the current position on the one hand and the active route and the alternative route sections of the active route tree on the other hand, the active route tree is stored as an inactive route tree in a route tree intermediate memory.

12. The method according to any one of claims 9 to 1 1, characterized in that after leaving the active route tree, the current position is compared with the stored elements in the route tree buffer elements of the inactive route trees, wherein upon determining the match of the current position with an element of the inactive route trees the route guidance is continued as an active route tree based on this inactive route tree.

13. The method according to any one of claims 1 to 12, characterized in that in the route buffer or in the route tree buffer several inactive routes or more inactive route trees are stored side by side.

14. The method according to claim 13, characterized in that when storing a further inactive route in the route buffer at least one inactive route depending on a comparison analysis, with which the inactive routes are evaluated, is deleted from the route buffer or the storage of the further inactive route in the route buffer depending on the comparative analysis with which the inactive routes are evaluated is discarded.

15. The method according to claim 14, characterized in that in the comparative analysis on the various inactive routes hitherto traveled travel time and / or the previously traveled distance are evaluated.

16. The method according to claim 14 or 15, characterized in that in the comparative analysis, the traveled since leaving the various inactive routes travel time and / or distance traveled are evaluated.

17. The method according to any one of claims 14 to 16, characterized in that in the comparative analysis required on the various inactive routes to reach the destination point travel time and / or route are evaluated.

18. The method according to any one of claims 1 to 17, characterized in that at least one inactive route is displayed with an associated label on the optical output device.

19. The method according to claim 18, characterized in that the display of the inactive routes can be configured, in particular switched off, is.

20. The method according to claim 1, wherein the route buffer or the route tree buffer is stored in a nonvolatile storage medium.

21. A method according to claim 20, characterized in that the non-volatile storage medium is write protected and will be described only after user approval.

22. The method according to any one of claims 1 to 21, characterized in that after detection of a significant deviation between the current position and the active route, a corresponding indication is output to the output device, wherein the intermediate storage of at least a portion of the previously active route as inactive route is triggered after input of an associated operator command to the input device.