Vehicular navigation system providing direction data

• US 5,938,718 A
• Filed: 09/06/1995
• Issued: 08/17/1999
• Est. Priority Date: 09/20/1994
• Status: Expired due to Term

• Current Assignee: Aisin AW Company Limited (Aisin Corp.)
• Original Assignee: Aisin AW Company Limited (Aisin Corp.)
• Inventors: Ishikawa, Wataru, Maekawa, Kazuteru, Nanba, Akimasa, Morimoto, Kyomi
• Primary Examiner(s): NGUYEN, TAN QUANG
• Application Number:
  US08/524,428
• Time in Patent Office: 1,441 Days
• Field of Search: 701/201, 701/202, 701/207, 701/208, 701/209, 701/211, 340/990, 340/995
• US Class Current: 701/201
• CPC Class Codes: G01C 21/3629 Guidance using speech or audio output, e.g. text-to-speech text to speech systems per se G10L13/00
• CPC Class Codes: G01C 21/3632 Guidance using simplified or iconic instructions, e.g. using arrows G01C21/365 takes precedence
• CPC Class Codes: G01C 21/3644 Landmark guidance, e.g. using POIs or conspicuous other objects
• CPC Class Codes: G01C 21/3655 Timing of guidance instructions
• CPC Class Codes: G01C 21/3658 Lane guidance
• CPC Class Codes: G01C 21/367 Details, e.g. road map scale, orientation, zooming, illumination, level of detail, scrolling of road map or positioning of current position marker

Abstract

In order to provide a driver with guidance for a direction of travel without confusing the driver even in a case where the angular difference between an approach road and a departing road at a branch point is very small or even when a branch point has a complicated shape, a navigation system is provided with present-position sensor for calculating present position of the vehicle; an input for entering information necessary for calculating a route; an output for giving notification of information for carrying out route guidance; an information storage device in which all data necessary to carry out route guidance has been stored; route calculator for calculating a route based upon the information entered by the input; route storage for temporarily storing the route calculated by the route calculator; and a guidance control unit for outputting guidance information relating to the route to the output. The information storage device stores branch-point data and road data connected to branch points and has direction data indicative of a departing road with respect to an approach road connected thereto by a branch point. The guidance control unit outputs the guidance information to the output based upon the direction data.

Claims

1. A navigation system for a vehicle, comprising:

present-position sensing means for calculating present position of the vehicle;

input means for entering information necessary for calculating a route;

output means for giving notification of information for carrying out route guidance;

an information storage device in which all data necessary to carry out route guidance has been stored;

route calculating means for calculating a route based upon the information entered by said input means; and

a central processor having route storage means for temporarily storing the route calculated by said route calculating means, and guidance control means for outputting guidance information relating to the route to said output means;

said information storage device storing branch-point data and road data connected to branch points and having destination direction data indicative of a departing road with respect to an approach road connected thereto by a branch point;

said guidance control means comprises determination means for determining whether or not destination direction data of a departing road with respect to an approach road connected thereto by a branch point is available in said route storage means, and an arithmetic means for calculating advancing direction based on angular difference which the departing road forms with the approach road and in case it is determined by said determination means that the destination direction data is available guidance information is outputted to the output means based on the destination direction data, and in case it is determined that the destination direction data is not available, advancing direction is calculated by said arithmetic means, and guidance information is outputted to the output means based on said advancing direction.

2. The system according to claim 1, wherein said output means comprises display means for giving notification, on a screen, of the information necessary to carry out route guidance, and/or voice output means for giving notification, by voice, of the information necessary to carry out route guidance, and that said guidance control means comprises display control means for outputting the guidance information to said display means and/or voice control means for outputting the guidance information to said voice output means.

3. The system according to claim 2, wherein said display control means outputs arrow information indicating direction based upon the destination direction data to said output means, and said display means displays an arrow on the screen based upon the arrow information.

4. A navigation system for a vehicle, comprising:

present-position sensing means for calculating present position of the vehicle;

input means for entering information necessary for calculating a route;

output means for giving notification of information for carrying out route guidance;

information storage means in which all data necessary to carry out route guidance has been stored;

route calculating means for calculating a route based upon the information entered by said input means; and

guidance control means for reading out data, which has been stored in said information storage means, along the route calculated by said route calculating means, and outputting this data to said output means;

wherein said information storage means stores route-guidance auxiliary information data, and said guidance control means reads data relating to a branch point at which guidance is required for travel forward of the present position, which has been sensed by said present-position sensing means, out of data relating to a route, which has been stored in said information storage means, in a case where the present position is on a route, currently being suggested, calculated by said route calculating means, said guidance control means having determination means for determining whether the route-guidance auxiliary information data is to be added onto guidance relating to said branch point, wherein when it has been determined by said determination means that the route-guidance auxiliary information is to be added onto the guidance relating to the branch point, said guidance control means adds the route-guidance auxiliary information onto the guidance relating to the branch point and then outputs the result to said output means.

5. The system according to claim 4, wherein said determination means retrieves data, from among data relating to a route calculated by said route calculating means and stored in said information storage means, within a predetermined range beyond the branch point at which guidance is required, and, in a case where the information-guidance auxiliary information data in said data, determines that said road-guidance auxiliary information data is to be added onto the guidance relating to said branch point.

6. The system according to claim 4, wherein said information storage means stores data, which is necessary to perform the route guidance, in correspondence with respective ones of roads connecting each branch point, and stores the route, calculated by said route calculating means, as a road sequence, and said determination means determines that said road-guidance auxiliary information data is to be added onto the guidance relating to said branch point in a case where, among the data stored in the road sequence of the route, the data of a road sequence within a predetermined distance beyond the branch point at which guidance is necessary or the data of a road sequence up to a road spanning a predetermined distance contains said road-guidance auxiliary information data.

7. The system according to claim 5 or 6, wherein said determination means determines that road-guidance auxiliary information retrieved first in order of proximity to the branch point is to be added onto the guidance relating to said branch point.

8. The system according to claim 4, herein said road-guidance auxiliary information data represents an overpass, a road alongside an overpass, an underpass, a road alongside an underpass or a direction name in a direction of travel at a branch point.