GB2375397A

GB2375397A - Vehicle navigation system and method

Info

Publication number: GB2375397A
Application number: GB0210444A
Authority: GB
Inventors: Arne Friedrichs; Gerd Draeger; Claus Brenner
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2001-05-09
Filing date: 2002-05-07
Publication date: 2002-11-13
Anticipated expiration: 2022-05-07
Also published as: FR2824634B1; JP2003057058A; FR2824634A1; SE0201377D0; SE524842C2; SE0201326D0; DE10122448A1; GB2375397B; SE0201377L; GB0210444D0

Abstract

The navigation system comprises a data processing device 12, a bearing system 14, such as a global positioning system, a mass memory 16 (eg CD-ROM), and a reception device 18. The reception device 18 communicates with a remote first service centre 22 and with a remote second service centre 26; the second service centre may be a sub-unit of the first service centre 22. Visual and audible output devices 28, 30 are included. A route to a destination may be determined and the location of the vehicle on a digital road map is determined and navigation instructions are audibly and/or visually outputted to the driver of the vehicle. The most favourable route is made available to the vehicle as a function of an instantaneous position of the vehicle and of a specifiable destination point broken down into defined segments and detailed items of route information are provided off-board by at least one second service centre 26.

Description

- 2375397

Method of operating a navigation system for a vehicle. in particular an automotive vehicle. and navigation system Technical field

The invention relates to a method of operating a navigation system and a navigation system for a vehicle, in particular for an automotive vehicle, in which data relating to the geographical position is determined by a bearing system and transmitted to an eleckonic data processing device with access to a database and a digital road map and, on the basis of said data, the location of the vehicle on the digital road map and navigation instructions are audibly and/or visually outputted to the driver.

Prior art

Navigation systems for vehicles, in particular automotive vehicles, and also methods of operating such navigation systems are known. These serve to determine the current geographical position of the vehicle and to calculate the most favourable journey route as a function of a specifiable destination point to be reached and to give the driver instructions relating to the journey route.

The known navigation systems require items of information that are necessary for the determination of the current location of the vehicle and the calculation of the journey route. These include, in particular, road patterns, turn-off conditions and the like. Said data are provided in the form of a database. For this purpose, the database comprises, for example, a so-called digital map containing road points and/or decision points of the possible routes. It is known to provide the database on fixed vehicle mass memories, for example a CD-

ROM. Fur errnore, a bearing system is necessary that determines the current geographical position of the vehicle. Known for this purpose, for example, is the satellite-aided global positioning system (GPS).

- An electronic data-processing device processes the position data supplied by the bearing system using the data stored in the digital road map and determines the current position of the vehicle. According to the chosen destination point, navigation information can now be given visually and/or audibly to the driver by He electronic data processing device on the basis of road points and/or decision points on a selected, most favourable journey route.

Also known are so-called off-board navigation systems in which the most favourable route is not calculated in the vehicle itself, but is undertaken by a service centre. In this case, the service centre provides the most favourable route to the vehicle via a transmission path. A disadvantage of such systems is that the service centre has to transmit large amounts of data for determining the most favourable route and, possibly, route corridor disposed around the most favourable route to a multiplicity of vehicles. This requires large data transmission capacities.

Presentation of the invention. object, achievement and advantages The object of He present invention is to provide a method of operating a navigation system for a vehicle and also to provide a navigation system of the generic kind with which large amounts of data can be made available in a simple way.

This object is achieved, according to the invention, by a n; ethod of the abovementioned type with the features stated in Claim 1.

Because the most favourable route or a route corridor is made available to the vehicle as a function of an instantaneous position of the vehicle and of a specifiable destination point of the vehicle broken down into defined segments and detailed items of route information are provided off- board by at least one second service centre for each of the defined segments, it is advantageously possible to reduce the total extent of the amount of data to be transmitted appreciably. The navigation system first receives the route broken down into the defined segments - depending on starting point and destination point - and only if detailed navigation instructions are necessary in at least one of the defined segments, these coming from the second service centre. As a result of

- such a structuring of the transmission of the items of information for a most favourable route or the associated route corridor, account can be taken of the circumstance that a multiplicity of vehicles that wish to travel the defined segments, that is to say, in particular, do not have any destination in said defined segments, are adequately supplied with initially only generally held items of route information. These are used to guide the vehicle via the navigation system when travelling the defined segments. In this case, only the entry point and the exit point from said defined segment are of interest for the vehicles. The latter consequently receive only the items of routing information that are necessary for a known entry point into the defined segment in order to reach the exit point from the defined segment. All other items of routing information within the defined segments consequently do not have to be calculated and transmitted.

As a result of the combination of the transmission of items of routing information with initially the defined segments for the entire most favourable route and the detailed items of routing information in every single one of the defined segments to be traversed by second service centres assigned to said segments, the calculated route or the associated route corridor does not consequently have to be made available individually to every vehicle but it is sufficient to transmit the relevant defined segments to the vehicles and, separately from this transmission of the defined segments, to transmit the interesting items of route information in the defined segments. It is consequently clear that, with a multiplicity of vehicles utilizing the same route, they have consequently to be supplied initially only with the items of route information relating to the defined segments.

This reduces the amount of data to be calculated and to be transmitted for the calculation and transmission of the most favourable route or of the most favourable route corridor? with the result that transmission capacities can be cut down. The individual, detailed items of route information within the individual defined segments can be made available identically for all the vehicles by the second service centre, with the result that the effort required for an individual calculation and provision is unnecessary.

: In a preferred refinement of the invention, provision is made that the second service centre operates in a locally limited manner and, preferably, the detailed items of route information transmitted by the second service centre are regularly repeated. This advantageously makes it possible to assign a separate second service centre to each of the defined segments of the entire route -

possibly to a plurality of connected defined segments of a route. Consequently, the items of route information that are provided in said second service centre and, if necessary, updated and transmitted are relatively limited so that an amount of data to be processed or to be transmitted is kept within confines.

Furthermore, a more rapid response to any necessary changing detailed items of route information, for example as a result of road closures, accident locations or the like, is possible at short notice. As a result of the regular repetition of the detailed items of route information by the second service centre, the necessary detailed items of route information are constantly available to all the vehicles entering the respective assigned defined segments or situated therein.

In a further preferred refinement of the invention, provision is made that the detailed items of route information are transmitted by the second service centres with a time shift, these being made available following one another in time, in particular according to the most favourable route pattern. This advantageously makes it possible not to have to transmit He appropriate detailed items of route information immediately at the start of the journey, but only during the reversal of the route by the respective vehicle. This reduces the amount of data to be made available initially at the start of the journey. This makes possible a more rapid calculation and transmission of the most favourable route and, consequently, a more rapid reception of the navigation during the start of the journey.

In a fiercer preferred refinement of the invention, provision is made that the detailed items of route information transmitted by the second service centres are made available on request, the request being initiated, in particular by the respective vehicle or by the first service cenke. This makes it advantageously possible to make available the detailed items of routing information in a time-

critical manner in the respective defined segments. In particular, every vehicle can call up the appropriate detailed route information, for example, on entering

the respective defined segment. This entry can be signalled either by the vehicle itself or is signalled by the quasi higher-level first service centre to the second service centres. This makes possible a precise provision, fulfilling the actual requirements, of the detailed items of route information in the respective defined segments. Furthermore, in a preferred refinement of the invention, provision is made that the most favourable route or the associated route corridor is made available offboard by the first service centre. This relieves the load on the navigation system to be concomitantly transported in the vehicles of additional functional effort, in particular for the calculation of the most favourable route or the associated route corridor. It can consequently be constructed more simply and less expensively.

According to a further preferred refinement of the invention, provision can be made that the most favourable route or the associated route corridor is made available by a mass memory concomitantly transported in the vehicle as a first service centre. Since the mass memory has only to provide the basis items of information relating to the defined segments, the respective amount of data to be kept available is reduced. The detailed items of route information in the respective defined segments are then made available externally by the second service centre.

In addition, in a preferred refinement of the invention, provision is made that the provision of the detailed items of route information are graded by the second service centres on the basis of urgency, in particular takes place as a function of the simultaneous request of a plurality of vehicles. This advantageously makes it possible to transmit the detailed items of route information on the basis of urgency to the vehicle for the purpose of reducing transmission capacity or of optimum utilization of an available transmission capacity. The urgency can preferably be provided on the basis of the actual position of the vehicles determined by the bearing system.

In a further preferred refinement of the invention, provision is made that the detailed items of route information are temporarily stored in the vehicle on entering the respective defined segment. This advantageously makes it possible that, when the vehicle enters the respective defined segment, the detailed items of route information for said defined segment are received by the second

service centre and are temporarily stored in the vehicle. As a result, only a single loading of the transmission path is necessary, with the result that the transmission capacity available can be optimally used. With every entry into a new defined segment of the route or of the route corridor, the detailed route information is then accessed again once, received and temporarily stored in the vehicle. Finally, in a further preferred refinement of the invention, provision is made that the detailed items of route information are exchanged between vehicles situated in the same defined segment. For this purpose, the vehicles may be in contact via telematics functions known per se and, under these circumstances, ascertain that they are traversing the same defined segment of a route or of a route corridor with the same journey destination valid for said defined segment, that is to say exit point from said defined segment or destination point in said defined segment. As a result, the information can be transmitted directly to at least one further vehicle by a vehicle that has already received the detailed route information from the second service centre. This likewise makes possible an optimum utilization of the available transmission capacities of the second service centre.

The object according to the invention is furthermore achieved by a navigation system of the abovementioned type having the features characterized in Claim 15. Because a device for providing defined segments of a route or of a route corridor as a function of an instantaneous position and a specifiable destination point of the vehicle and a reception device for receiving detailed items of routing information for the defined segments of the route or of the route corridor are provided, it is advantageously possible to provide a navigation system that has a simple structure and can be used flexibly for various routes or route corridors.

Further preferred refinements of the invention emerge from the features stated in the subclaims.

Brief description of the drawings

The invention is explained in greater detail below in an exemplary embodiment using the accompanying drawings. In the drawings: Figure 1 shows a block circuit diagram of the navigation system according to the invention; Figure 2 shows a diagrammatic total overview of the navigation system according to the invention; Figure 3 shows diagrammatically the subdivision of a region into defined segments, and Figure 4 shows the determination of a most favourable route.

Best method of implementing the invention Figure 1 shows diagrammatically a navigation system, denoted in its entirety by 100, for an automotive vehicle. The navigation system 100 comprises an electronic dataprocessing device 12, which may comprise microprocessors, memory elements or the like, which are not shown in detail. Furthermore, the navigation system 100 comprises a bearing system 14, for example a global positioning system (GPS) known per se. A mass memory 16, for example, a CD-ROM, and a reception device 18 are optionally assigned to the device 12.

The reception device 18 communicates via a first bidirectional transmission path 20 with a higher-level, first service centre 22. Furthermore, the reception device l 8 is in contact with second service centre 26 via a second unidirectional transmission path 24.

The navigation system 100 furthermore comprises a visual output device 28, for example a display or the like and/or an audible output device 30, for example a loudspeaker or the like.

Figure 2 shows diagrammatically the use of the navigation system 100 according to the invention. The navigation system 100 is assigned in each case to a vehicle 32. Certain parts of the navigation system 100, in particular the

service centres 22 and 26 and also the transmission paths 20 and 24 are simultaneously assigned to a multiplicity of navigation systems 100 of a multiplicity of vehicles 32. A connection to the first service centre 22, which comprises a reception and transmission device 34, exists via the transmission path 20. Furthermore, a so-called route server 36 that communicates with a database 38 is provided in the service centre 22. The second service centre 26 has a transmission device 40 via which the transmission path 24 to the vehicles 32 is set up.

The first service centre 22 may be in contact with the second service centre or service centres 26 via a transmission path 42.

According to various design variants, provision may be made that the second service centres 26 are integrated in the first service centre 22 as subunits. It is, however, also possible that the second service centres 26 operate completely autarcally. The navigation system 100 shown diagrammatically using Figures 1 and 2 is operated in accordance with the method according to the invention, which is explained below using Figures 3 and 4.

Figure 3 shows a region G within a map extending over the segment shown in all directions. The map, and consequently the region G. is subdivided into defined segments 44. In accordance with the exemplary embodiment, the segments 44 are approximately square in shape and defined exactly by an alphanumerical system. Each of the segments 44 can be defined exactly and, consequently, identified by the exemplary assignment of each of the segments 44 to a letter and to a numeral. Consequently, an identification characteristic is, for example, Al, A2 etc. To explain the exemplary embodiment, let it be assumed that the region G is skirted by a motorway AD extending in a north-south direction. The region G is connected to the motorway AO via a Federal road BO extending in an east-west direction. Within the region G. main roads HO or H1 open onto the Federal road BO. Further side roads and the like not shown in Figure 3 branch of said main roads HO and Hi. From the diagram in Figure 3' it becomes clear that

each of the roads, whether a motorway, Federal road, main road or side road, touches at least one of the defined segments 44, as a rule a plurality of the defined segments 44.

The navigation system 100 according to the invention is therefore based on the following consideration. The vehicles 32 within the permanently specified region G have, as a rule, various journey destinations. In regard to the region G specified, however, the destinations are frequently identical. For a vehicle 32 situated within the region G. one of the following statements is always

applicable: 1. "The destination point is in the region G." or 2. "The destination point is outside the region G and can be reached by leaving the region G on the Federal road BO in a westerly direction" or 3. "The destination point is outside G and can be reached by leaving the region G on the Federal road BO in an easterly direction."

Of these Tree possibilities, only the first alternative requires an individually calculated route. The second and the third alternatives, on the other hand, can be handled by a precalculated route with navigation instructions that do not require individual, detailed items of route information.

Since, as a rule, the majority of the vehicles 32 use routes of the alternatives 2 and 3 when travelling through the region G. this applies to through traffic through the region G and also to all journeys that have a starting point in G and whose destination point is outside G. This plurality of vehicles 32 can therefore utilize identical, not individual, items of route information.

Referring to Figure 4, a possible case is assumed according to which the starting point for a vehicle 32 is situated in the defined segment 44 having the identifier E3 and its destination point, which is not shown, can be reached by traversing the motorway AO in a northerly direction. The most favourable route resulting therefrom can be characterized completely by means of the defined

segments 44. For the case explained, following the most favourable route with the respectively assigned navigation instruction is valid for positions assumed by the vehicle 32 in the respective defined segments 44, which can be determined by the bearing system 14 not to be considered in greater detail here: Position Segment routing ID I Segment routing used E3 E3-2 "Am driving on HO" E2 E2-1 "Am driving and remaining on HO in a northerly direction" D2 D2-1 "Am driving and remaining on HO in a northerly direction" C2 C2-2 "Am driving and remaining on BO in an easterly direction" C3 C3-2 "Am driving and remaining on BO in an easterly direction" C4 C4-2 "Am driving and remaining on BO in an easterly direction" C5 C5-2 "Am driving and remaining on BO in an easterly direction" C6 C6-2 "Am driving and remaining on BO in an easterly direction" C7 C7-1 "Am driving and remaining on AO in northerly direction" B7 B7-2 "Am driving and remaining on AO in northerly direction" A7 B7-2 "Am driving and remaining on AO in northerly direction" It becomes clear that an individually calculated, most favourable route or route corridor comprising the route does not have to be transmitted to the vehicles 32. It is sufficient to transmit the relevant segment routing identifiers (IDs) to the vehicle 32. Individual detailed route information within each of the segments 44 can consequently be made available by another method.

Extrapolated to the structure explained using Figures 1 and 2 of the navigation system 100, this means that the relevant segment routing identifiers are transmitted to the vehicle 32 via the first service centre 22. Because of the reduced information requirement and consequently, reduced amounts of data to be transmitted, its transmission capacity can be optimally utilized.

The individual detailed items of route information are received in each case by the vehicle 32, if necessary, from the second service cenke 26. In this connection, provision can be made that a separate second service centre 26 is assigned to each of the segments 44. However, provision can also be made that a common second service centre 26 is assigned to a group of segments 44, for example all the segments 44 within a region G. Since the representation in Figures 3 and 4 took place only in sections, it becomes clear that a multiplicity of second service centres 26 may be assigned to a central, higher-level service centre 22 when considered over the entire map. It is also possible to integrate the second service centre 26 in the first service centre 22 as a lower-level plane and to make available appropriate subcapacities of the route server 36 to each of the lower-level service centres 26. The second service centres 26 may, for example, operate in a broadcast-based manner. However, other transmission methods, for example mobile-radio-based media or the like are also possible.

It becomes clear that, since the plurality of vehicles 32 within the region G need only the reduced items of information, namely the segment routing identifiers, there are substantially reduced requirements imposed on the total bandwidth of the data transmission of the first service centre 22. Only if a vehicle 32 travelling in the region G actually has its destination in the region G does it require the individual detailed items of route information via the second service centre 26.

The individual detailed items of route information can be requested, for example, directly by the vehicle 32 if it enters a first segment 44 of the region G. It is also conceivable that, because of the position knowledge obtained via the bearing system, the first service centre 22 informs the second service centres 26 via the transmission path 42 that a vehicle 32 is now entering the coverage region G and requires individual detailed items of route information.

Depending on a number of vehicles 32 to be serviced simultaneously, an

urgency hierarchy can also be taken into account here, depending on how far away the vehicles 32 are situated from their respective end points.

Furthermore, from the representations, it becomes clear that the individual detailed items of route information do not have to be transmitted immediately to the respective vehicles 32 at the start of their journey. Said items of information only actually need to be transmitted when the vehicles 32 enter the region G. In this case, the individual detailed items of route information are continuously broadcast over the region G via the transmission device 40 of the second service centre 26, preferably in a sequence that repeats in time, so that all the vehicles 32 that are situated therein and whose destination point is in the region G can repeatedly utilize currently the appropriate items of route information. It is also conceivable that' on first entering the region G. however, the individual detailed items of route information are received once by the respective vehicle 32 and are temporarily stored so that the appropriate navigation instructions can be given to the respective driver.

Claims

Claims 1. Method of operating a navigation system for a vehicle, in

particular an automotive vehicle, in which data relating to the geographic positions of the vehicle are determined by a bearing system and are transmitted to an electronic data-processing device with access to a database and a digital road map and, on the basis of said data, the location of the vehicle on the digital road map is determined and navigation instructions are audibly and/or visually outputted to the driver of the vehicle, characterized in that the most favourable route or a route corridor is made available to the vehicle as a function of an instantaneous position of the vehicle and of a specifiable destination point of the vehicle broken down into defined segments and detailed items of route information are provided off-board by at least one second service centre for each of the defined segments.
2. Method according to Claim 1, characterized in that the at least one second service centre is locally limited, in particular operates for at least one of the defined segments.
3. Method according to one of the preceding claims, characterized in that the items of route information transmitted by the second service centre are regularly repeated.
4. Method according to one of the preceding claims, characterized in that the items of route information transmitted by the second service centre are made available with a time shift for the entire route.
5. Method according to Claim 4, characterized in that the items of route information transmitted by the second service centre corresponding to the most favourable route pattern are made available following one another in time.
6. Method according to one of the preceding claims, characterized in that the items of route information transmitted by the second service centre are made available on request.
7. Method according to Claim 6, characterized in that the requests are initiated by the vehicle.
8. Method according to Claim 6, characterized in that the requests are initiated by the first service centre.
9. Method according to one of the preceding claims, characterized in that the most favourable route or the route corridor is made available by a mass memory.
10. Method according to one of the preceding claims, characterized in that the most favourable route or the route corridor is made available off-

board.
11. Method according to one of the preceding claims, characterized in that the provision of the detailed items of route information is graded on the basis of urgency.
12. Method according to one of the preceding claims, characterized in that the provision of the detailed items of route information takes place as a function of the simultaneous request of a multiplicity of vehicles.
13. Method according to one of the preceding claims, characterized in that the detailed items of route information are temporarily stored in the vehicle on entering the defined segment.
14. Method according to one of the preceding claims, characterized in that the detailed items of route information are exchanged between vehicles situated in the same defined segment.
15. Navigation system for a vehicle, in particular an automotive vehicle, comprising a bearing system, an electronic data-processing device that has access to a database having a digital road map and at least one output device for an audible and/or visual navigation instruction, characterized by a device (16, 22) for providing defined segments (44)

of a route or of a route corridor as a itnction of an instantaneous position and of a specifiable destination point of the vehicle and a reception device (18) for receiving detailed items of routing information for the defined segments (44) of the route or of the route corridor.
16. Navigation system according to Claim 15, characterized in that the device (16) is a mass memory.
17. Navigation system according to Claim 15, characterized in that the device (22) is an off-board service centre (22).
18. Navigation system according to Claim 17, characterized in that the service centre (22) is connected to the reception device (18) via a transmission path (20).
19. Navigation system according to one of the preceding claims, characterized in that the detailed items of route information can be provided by at least one second service centre (26) that can be connected to the reception device (18) via a transmission path (24).
20. Navigation system according to Claim 19, characterized in that the transmission path (24) operates in a broadcast-based manner.
21. Navigation system according to Claim 19, characterized in that the transmission path (20) operates in a mobile-radio-based manner.
22. Navigation system according to one of the preceding claims, characterized in that the at least one second service centre (26) is integrated in the first service centre (22) as a sub-unit.
23. A method of operating a navigation system for a vehicle substantially as herein described with reference to the accompany drawings.
24. A navigation system for a vehicle substantially as herein described with reference to the accompanying drawings.