Navigation system and method for calculating a guide route

• US 6,351,707 B1
• Filed: 02/25/1998
• Issued: 02/26/2002
• Est. Priority Date: 02/25/1997
• Status: Expired due to Term

• Current Assignee: Alpine Electronics Incorporated (Alps Alpine Co., Ltd.)
• Original Assignee: Alpine Electronics Incorporated (Alps Alpine Co., Ltd.)
• Inventors: Ichikawa, Shigeru
• Primary Examiner(s): Issing, Gregory C.
• Application Number:
  US09/030,707
• Time in Patent Office: 1,462 Days
• Field of Search: 701/209, 701/210, 701/204, 340/994
• US Class Current: 701/209
• CPC Class Codes: G01C 21/3492 employing speed data or traffic data, e.g. real-time or historical traffic control systems for road vehicles involving transmission of navigation instructions to the vehicle G08G1/0968
• CPC Class Codes: G08G 1/096827 where the route is computed onboard
• CPC Class Codes: G08G 1/096861 where the immediate route instructions are output to the driver, e.g. arrow signs for next turn
• CPC Class Codes: G08G 1/096872 where instructions are given per voice

Abstract

The invention provides a navigation system that is able to accurately calculate the cost during searching or guiding a route. The navigation controller of the navigation system is comprised of a map buffer that stores various data for displaying maps and searching routes, a route search processor for searching routes, a guide route memory, and a route search memory. When the search key of the remote control unit is pressed, the route search processor makes an intersection network list necessary for a route search between two intersections to store in the route search memory. Further, the route search processor modifies a link cost in the route search memory by replacing it with a statistical cost representing a statistically obtained time that is required for actually passing through the road link, and executes the route search on the basis of the modified cost data.

Claims

1. A navigation system comprising:

position detection means for detecting a present position of a vehicle;

destination input means for identifying a destination;

map data storage means for storing road data for a plurality of roads, including a statistical required time for at least some of the roads where the statistical required time associated with a particular road represents the time required for actually traveling the road, statistically obtained, and is not based on traffic information transmitted to the vehicle from outside the vehicles and by-pass road information to indicate whether or not a road is a by-pass road; and

route search processing means for searching a route from a present position detected by the position detection means to a destination identified by the destination input means on the basis of the road data, wherein the route search processing means executes a route search by using a time to pass through a road, obtained on the basis of received traffic information when traffic information transmitted from outside the vehicle is received, and the statistical required time, when the traffic information is not available on a road and the statistical required time is available;

wherein the statistical required time data is pre-set in the map data storage means and is determined without the involvement of a user, and the route search processing means gives priority to a road identified as a by-pass road in searching a guide route, if the statistical required time and the traffic information is not available for the road.

2. A navigation system as claimed in claim 1, wherein the statistical required time is a time statistically obtained and required for passing through a road unit indicated by a start point and an end point.

3. A navigation system as claimed in claim 2, wherein the road unit is a road link between intersections stored in the map data storage means.

4. A navigation system as claimed in claim 3, wherein the route search processing means includes a conversion table for converting a road link contained in the traffic information transmitted from outside the vehicle into a corresponding road link stored in the map data storage means.

5. A navigation system comprising:

position detection means for detecting a present position of a vehicle;

destination input means for identifying a destination;

map data storage means for storing road data for a plurality of roads, including a statistical required time for at least some of the roads where the statistical required time associated with a particular road represents the time required for actually traveling the road, statistically obtained, and is not based on traffic information transmitted to the vehicle from outside the vehicle, and by-pass road information to indicate whether or not a road is a by-pass road;

route search processing means for searching a guide route from a present position detected by the position detection means to a destination identified by the destination input means on the basis of the road data;

route guiding means for guiding a driver to the destination in accordance with the guide route searched by the route search processing means; and

required time calculation means for calculating an estimated arrival time at the destination or a required time to reach the destination, wherein the required time calculation means calculates an estimated arrival time at the destination or a required time to reach the destination by using a time to pass through a road, obtained on the basis of received traffic information when traffic information transmitted from outside the vehicle is received, and the statistical required time, when the traffic information is not available on a road and the statistical required time is available;

wherein the statistical required time data is pre-set in the map data storage means and is determined without the involvement of a user, and as to a road identified as a by-pass road where the statistical required time and the traffic information is not available, the required time calculation means calculates a required time to pass through a unit distance that is shorter than a required time to pass through the unit distance on a non-by-pass road.

6. A navigation system as claimed in claim 5, wherein the statistical required time is a time statistically obtained and required for passing through a road unit indicated by a start point and an end point.

7. A navigation system as claimed in claim 6, wherein the road unit is a road link between intersections stored in the map data storage means.

8. A navigation system as claimed in claim 7, wherein the route search processing means includes a conversion table for converting a road link contained in the traffic information transmitted from outside the vehicle into a corresponding road link stored in the map data storage means.

9. A method for searching a route, comprising the steps of:

identifying a start point and a destination;

reading out road data from a map data storage means containing road data for a plurality of roads, including a statistical required time for at least some of the roads where the statistical required time associated with a particular road represents the time required for actually traveling the road, statistically obtained, and is not based on traffic information transmitted to the vehicle from outside the vehicle, and by-pass road information to indicate whether or not a road is a by-pass road; and

searching a route between the start point and the destination on the basis of the road data, wherein the route is searched by using a time to pass through a road obtained on the basis of received traffic information when traffic information transmitted from outside the vehicle is received, and the statistical required time when the traffic information is not available on a road and the statistical required time is available;

wherein the statistical required time data is pre-set in the map data storage means and is determined without the involvement of a users and as to a road where the statistical required time and the traffic information is not available, a road identified as a by-pass road on the basis of the by-pass road information is given priority in searching a guide route.

10. A method for searching a route comprising the steps of:

identifying a start point and a destination;

reading out road data from a map data storage means containing road data for a plurality of roads, including a statistical required time for at least some of the roads where the statistical required time associated with a particular road represents the time required for actually traveling the road, statistically obtained, and is not based on traffic information transmitted to the vehicle from outside the vehicle, and by-pass road information to indicate whether or not a road is a by-pass road;

searching a guide route from the start point to the destination on the basis of the road data; and

calculating an estimated arrival time at the destination or a required time to reach the destination when guiding the driver to the destination in accordance with the searched guide route, wherein an estimated arrival time at the destination or a required time to reach the destination is calculated by using a time to pass through a road obtained on the basis of received traffic information when traffic information transmitted from outside a vehicle is received, and the statistical required time when the traffic information is not available on a road and the statistical required time is available;

wherein the statistical required time data is pre-set in the map data storage means and is determined without the involvement of a user, and as to a road identified as a by-pass road where the statistical required time and the traffic information is not available, a required time to pass through a unit distance is set shorter than a required time to pass through the unit distance on a non-by-pass road.

11. A method for searching a route as claimed in claim 10, wherein the statistical required time is a time statistically obtained and required for passing through a road unit indicated by a start point and an end point.

12. A method for searching a route as claimed in claim 11, wherein the road unit is a road link between intersections stored in the map data storage means.