Route guidance system, information delivery center, and vehicular route guidance apparatus

• US 20030033083A1
• Filed: 08/08/2002
• Published: 02/13/2003
• Est. Priority Date: 08/09/2001
• Status: Active Grant

• Current Assignee: Aisin AW Company Limited (Aisin Corp.)
• Original Assignee: Aisin AW Company Limited (Aisin Corp.)
• Inventors: Nakashima, Hideki, Ishida, Akira, Masuda, Hiroyoshi, Hayama, Yoichi
• Granted Patent: US 6,904,362 B2
• Time in Patent Office: Days
• US Class Current: 701/211
• CPC Class Codes: G01C 21/3626 Details of the output of route guidance instructions traffic control systems for road vehicles involving transmission of navigation instructions to the vehicle G08G1/0968

Abstract

An information center generates packets of route guidance information, each corresponding to a prescribed road length of a recommended route. The information center may generate major guide point information and guidance information and transmit both to a vehicular apparatus. The vehicular apparatus provides guidance only for major guide points based on the received major guide point information if it cannot receive the guidance information. According to another aspect of the invention, if the end of a route segment which was the subject of the preceding route guidance information is on an expressway or toll road, guidance information for a preliminary route from that end to an escape position ahead on the expressway or toll road is first transmitted and then information for a remaining route, that is a segment of the recommended route having the prescribed road length minus the preliminary route, is then transmitted. If communication with the information center is lost, the vehicular apparatus performs guidance for the preliminary route to an interchange, for example, of the expressway using the preliminary route guidance information.

Claims

1. A navigation system comprising:

(a) an information center comprising a transmission/reception section for communication, a route search section for searching for a route, based on a present position and destination, and an information generating section for generating major guide point information and guidance information for the route thus found; and

(b) a vehicular apparatus comprising a destination setting section for setting a destination, a present position determination section for determining the present position, and a guidance output section for outputting guidance for major guide points and route guidance, and a transmission/reception section for transmitting the set destination and the determined present position to the information center and for receiving the major guide point information and the guidance information from the information center, said guidance output section giving guidance limited to the major guide point information when the transmission/section is unable to receive the guidance information from the information center.

2. The navigation system according to claim 1, wherein the vehicular apparatus repeatedly updates the present position and transmits the updated present position to the information center, and the information center updates the guidance information based on the updated present position and transmits the updated guidance information to the vehicular apparatus.

3. An information center comprising:

(a) a transmission/reception section for communication;

(b) a route search section for searching for a route; and

(c) an information generating section for generating major guide point information and guidance information for the found route, wherein the information center searches for the route based on a present position and a destination that are received from a vehicular apparatus and transmits, to the vehicular apparatus, the generated major guide point information and the guidance information.

4. The information center according to claim 3, wherein the major guide point information includes a name of an interchange of one of an expressway, a toll road, or a high level of a multi-level road.

5. The information center according to claim 4, wherein if an end, most distant from the present position, of a segment of the found route having a prescribed road length is on an expressway, toll road or a high level of a multi-level road, the information center transmits the name of the interchange to the vehicular apparatus.

12. The route guidance system according to claim 5, wherein the escape location on the expressway or toll road is an interchange, a service area, or a parking area.

6. A vehicular apparatus for use in a vehicle comprising:

(a) a transmission/reception section for communication;

(b) a destination setting section for setting a destination;

(c) a present position determination section for determining a present position; and

(d) a guidance output section for outputting a guidance for major guide points and route guidance wherein the vehicular apparatus transmits the destination and the present position to an information center, receives, from the information center, first major guide point information to be followed by guidance information for a route that has been found by a search based on the destination and the present position, and gives guidance for the major guide points when unable to receive the guidance information.

7. The vehicular apparatus according to claim 6 wherein:

said transmission/reception section receives plural transmissions, each transmission first conveying, within a first period of transmission, the major guide point information for a segment of the found route, followed by the guidance information for the segment of the found route, within a second period of transmission which is significantly longer than the first period of transmission, and wherein the segments of the plural transmissions each have a prescribed length.

8. The vehicular apparatus according to claim 6, wherein the vehicular apparatus does not give guidance for a major guide point that the vehicle has already passed.

9. A route guidance system comprising:

an information delivery center for generating route guidance information for a recommended route from a present position to a destination in response to a request from a vehicular route guidance apparatus and for transmitting the generated route guidance information to the vehicular route guidance apparatus in a series of transmissions, each transmission providing guidance information for a segment of a recommended route, said route segment having a prescribed length, the information delivery center comprising;

search means for searching for the recommended route from the present position to the destination;

preliminary route guidance information generating means for generating, if an end of a route segment, for which the preceding transmission provided guidance information, is on an expressway or a toll road, preliminary route guidance information for a preliminary route from the route segment end to an escape position, ahead of the route segment end, on the expressway or toll road;

remaining route guidance information generating means for generating remaining route guidance information for a remaining route that is a route segment of the prescribed road length minus the preliminary route;

transmitting means for first transmitting the preliminary route guidance information to the vehicular route guidance apparatus and then transmitting the remaining route guidance information to the vehicular route guidance apparatus; and

wherein said vehicular route guidance apparatus performs route guidance using the route guidance information transmitted from the information delivery center, and comprises;

route guidance means for providing route guidance for the recommended route ahead of the route segment end, when communication with the information delivery center has failed, from the route segment end to an escape location on the expressway or toll road using the preliminary route guidance information that has been received.

10. The route guidance system according to claim 9, wherein the vehicular route guidance apparatus further comprises:

road data storing means in which road data is stored;

route search means for searching for a route to the destination using the road data of the road data storing means; and

route guidance information generating means for generating route guidance information for guidance along the route that has been found by the route search means.

11. The route guidance system according to claim 9, wherein the escape location on the expressway or toll road is an escape location that is ahead of and closest to the route segment end.

13. An information center for receiving information for a present position and information for a destination from a vehicular route guidance apparatus, for generating route guidance information corresponding to a segment of a recommended route having a prescribed road length, and for transmitting the generated route guidance information to the vehicular route guidance apparatus, the information delivery center comprising:

search means for searching for the recommended route from the present position to the destination;

preliminary route guidance information generating means for generating, if an end of a route segment which is the subject of preceding transmission of route guidance information is on an expressway or toll road, preliminary route guidance information for a preliminary route from the segment end to an escape location ahead on the expressway or toll road;

remaining route guidance information generating means for generating remaining route guidance information for a remaining route that is a segment of the recommended route having the prescribed road length minus the preliminary route; and

transmitting means for first transmitting the preliminary route guidance information to the vehicular route guidance apparatus and then transmitting the remaining route guidance information to the vehicular route guidance apparatus.

14. A vehicular route guidance apparatus for receiving, in succession, transmissions of route guidance information from an information delivery center, each transmission containing guidance information for a segment of a recommended route, said segment having a prescribed road length, and for providing route guidance to a destination using route guidance information provided by the succession of transmissions, said vehicular route guidance apparatus comprising:

route guidance information storing means for receiving, from the information delivery center, preliminary route guidance information, generated when an end of a segment, which was the subject of route guidance information of a preceding transmission, is on an expressway or toll road, said preliminary route information corresponding to a preliminary route from the end of the segment to an escape location ahead on the expressway or toll road, and for receiving from the information center remaining route guidance information for a remaining route that is a segment of the recommended route having the prescribed road length minus the preliminary route, and for storing the remaining route guidance information and the preliminary route guidance information; and

route guidance means for providing route guidance for the recommended route ahead of the segment end, when a failure occurs in communication with the information delivery center, from the segment end to the escape location on the expressway or toll road using the received preliminary route guidance information.

15. A route guidance system for a vehicle comprising:

an information delivery center for transmitting, to a vehicular route guidance apparatus, route guidance information for route guidance to a destination, said information delivery center comprising;

search means for searching for a recommended route to the destination; and

transmitting means for transmitting, to the vehicular route guidance apparatus, route guidance information for guidance along the recommended route; and

wherein the vehicular route guidance apparatus provides route guidance, based on the route guidance information transmitted from the information delivery center, and comprises;

data storage means in which road data is stored; and

re-search means for again searching for a route using the stored road data, when a failure has occurred in communication with the information delivery center.

16. The route guidance system according to claim 15, wherein the re-search means judges, based on route information, whether the vehicle has exited an expressway or toll road.

17. The route guidance system according to claim 15, wherein the re-search means searches for a route using the stored road data on condition that the failure in communication with the information delivery center occurred while the vehicle was travelling on a road other than an expressway or toll road.

18. The route guidance system according to claim 15, wherein the re-search means searches for a route again further on condition that the vehicular route guidance apparatus has not received information for the recommended route ahead of the present position of the vehicle.

19. The route guidance system according to claim 15, further comprising matching means for performing map matching of the vehicle present position when a failure in communication with the information delivery center has occurred and the vehicle has exited an expressway or toll road, and

wherein the re-search means searches for a route again on condition that the map matching has placed the present position of the vehicle on a road other than an expressway or toll road.

20. A method for communication of guidance information between a central information center and plural vehicles each equipped with a vehicular navigation apparatus, said method comprising:

transmitting from the vehicular navigation apparatus to the central information center information identifying a present position of a vehicle and a destination;

searching, within the central information center, to determine a recommended route from the present vehicle position to the destination;

generating guidance information for the recommended route within the central information center;

transmitting the generated guidance information, as a series of transmissions, to the vehicular navigation apparatus, each of said transmissions providing guidance information for a segment of the recommended route having a prescribed length, each of said transmissions including a first portion of guidance information of short duration to be utilized for guidance in the event of a failure in communication between the central information center and the vehicular navigation apparatus and a second portion providing more detailed guidance information for the route segment and having a duration significantly longer than that of said first portion.