Method for making available route data for a navigational device
View Patent ↗For the purpose of making available route data for a navigational device, an overall route is divided up into route segments which each include a part of the overall route. A first route segment is transmitted to the navigational device, upon its request, which around the starting point includes a starting field including a plurality of possible routes, as well as a main route to an intermediate destination. Before the intermediate destination is reached, a further route segment is transmitted to the navigational device, which includes a plurality of possible routes around the intermediate destination as its starting field, as well as a main route to an additional intermediate destination or to the destination itself. The latter step is repeated for route segments for further intermediate destinations until the destination is reached.
1. A method for making available route data for a navigational device, comprising:
dividing up a route from a starting point to a destination requested by the navigational device into a plurality of route segments each including a part of the route;
transmitting a first route segment to a navigational unit of the navigational device upon request, the first route segment including a starting field around the starting point, the starting field including a plurality of possible routes and a main route to an intermediate destination on the route to the destination;
transmitting a second route segment, before the intermediate destination is reached, to the navigational unit of the navigational device, the second route segment including a plurality of possible routes around the intermediate destination as a starting field and a main route to one of an additional intermediate destination on the route to the destination and the destination; and
repeating the second route segment transmitting step for additional route segments for additional intermediate destinations until the destination is reached.
2. The method of claim 1 , further comprising selecting the intermediate destination of a route segment within a starting field of a subsequent route segment.
3. The method of claim 1 , further comprising:
transmitting to the navigational device as additional information at least one of a travel time and a distance to the starting point to at least one of at least one intermediate destination and the destination.
4. The method of claim 1 , further comprising determining the starting field for the route segment with respect to one of information content of the route segment and a size of the route segment by at least one of a position finding quality, a positioning accuracy, a shape of the starting field, a circumference of the starting field, a diameter of the starting field and a radius of the starting field.
5. The method of claim 1 , further comprising transmitting, in response to a follow-on request of the navigational device to a server, a plurality of parameters that influence a routing algorithm so that a route starting from an intermediate destination is continued exactly as computed starting from the starting point.
6. The method of claim 1 , further comprising selecting a size of the starting field as a function of at least one of a vehicle speed, a street classification, a position-finding type and a position-finding accuracy.
7. A method for making available route data for a navigational device, comprising:
dividing up a route from a starting point to a destination requested by the navigational device into a plurality of route segments each including a part of the route;
transmitting a first route segment to a navigational unit of the navigational device upon request, the first route segment including a starting field around the starting point, the starting field including a plurality of possible routes and a main route to an intermediate destination on the route to the destination;
transmitting a second route segment, before the intermediate destination is reached, to the navigational unit of the navigational device, the second route segment including a plurality of possible routes around the intermediate destination as a starting field and a main route to one of an additional intermediate destination on the route to the destination and the destination;
repeating the second route segment transmitting step for additional route segments for additional intermediate destinations until the destination is reached; and
providing an advisory notice on a display unit during a time period of loading a route segment into a display unit of the navigational device that no navigation is occurring.
8. The method of claim 1 , further comprising:
transmitting to the navigational device as additional information at least one of a travel time and a distance from the starting point to at least one of at least one intermediate destination and the destination.
9. The method of claim 1 , further comprising:
transmitting to the navigational device as additional information at least one of a travel time and a distance from the intermediate destination to at least one of the starting point and the destination.
10. The method of claim 1 , wherein the route segments are loaded into a volatile memory by a CD-ROM.
11. The method of claim 1 , wherein each intermediate destination lies on a main route from the starting point to the destination.
12. The method of claim 1 , wherein each of the route segments includes at least one of a map geometry, driving instructions, and travel times.
13. The method of claim 1 , wherein each of the route segments is restricted to at least one of a maximum available memory of the navigational device, a maximum length, a maximum travel time, and a maximum fuel usage.
14. The method of claim 1 , wherein each starting field includes additional starting points, and wherein the possible routes include routes from each of the additional starting points.
15. The method of claim 1 , further comprising:
performing map matching after a segment of the plurality of segments is loaded.