On-board vehicle navigation apparatus

• US 5,774,071 A
• Filed: 11/28/1995
• Issued: 06/30/1998
• Est. Priority Date: 11/30/1994
• Status: Expired due to Term

• Current Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Original Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Inventors: Kawakami, Tetsuya, Konishi, Hitoshi, Arai, Masayuki
• Primary Examiner(s): Swarthout, Brent A.
• Assistant Examiner(s): Tweel, Jr., John
• Application Number:
  US08/566,570
• Time in Patent Office: 945 Days
• Field of Search: 340/988, 340/995, 340/990, 701/211, 701/208, 701/209
• US Class Current: 340/988
• CPC Class Codes: G01C 21/3655 Timing of guidance instructions

Abstract

An on-board vehicle navigation apparatus which gives road directions to a driver which accurately describe the road conditions beyond an intersection at which to turn, without causing any confusion even if the route is complicated. A route planning section 9 determines a route based on the current position of the vehicle which is obtained through a current position determination section 2 and a destination assigned by a destination assignment section 10. The guide intersections which form this route are stored in a guide intersection memory 11. A route guidance section 12 continually monitors the current position of the vehicle and announces navigational instructions through a speaker 13 when the vehicle approaches a guide intersection. The type of navigational instruction is changed depending on the distance between the next two guide intersections through which the vehicle will pass.

Claims

1. An on-board vehicle navigation apparatus, comprising:

a road network memory device which stores road network data;

a destination assignment means which assigns a destination for a vehicle;

a guide intersection assignment means which assigns guide intersections to be passed in reaching said destination by using said road network data;

an oral instruction means for providing an oral instruction which orally indicates directions to turn when said vehicle nears a first next guide intersection of the assigned said guide intersections from a current position of said vehicle;

a remaining distance determination means which determines whether or not the distance between a present position of the vehicle and said first next guide intersection is less than a first standard distance and a second standard distance which is shorter than the first standard distance;

an intersection distance determination means which determines whether or not the distance between said first next guide intersection and a second next guide intersection immediately subsequent to said first next guide intersection among said guide intersections is less than a third standard distance; and

an oral instruction addition means which, when the remaining distance determination means determines that the distance between the present vehicle position and said first next guide intersection is less than the second standard distance and when the intersection distance determination means determines that the distance between said first next guide intersection and said second next guide intersection is less than said third standard distance, adds a first additional oral instruction relating to said second next guide intersection to an original oral instruction which is given upon approaching said first next guide intersection;

wherein said oral instruction addition means adds a second additional oral instruction instead of said first additional oral instruction when the distance between said first next guide intersection and said second next guide intersection is less than a fourth standard distance which is less than said third standard distance, and said second additional oral instruction indicating an urgency of a vehicle maneuver required at said second next guide intersection, which urgency is not indicated by said first additional oral instruction.

2. An on-board vehicle navigation apparatus according to claim 1, wherein said oral instruction addition means is provided with an additional instruction changing means that changes said second additional oral instruction to said first additional oral instruction when another intersection exists between said first next guide intersection and said second next guide intersection even when the distance between said first next and second next guide intersections is less than said fourth standard distance.

3. An oral guidance method for an on-board vehicle navigation system wherein guide intersections to be passed in reaching a pre-set vehicle destination are assigned based on road network data and said destination, and oral instructions as to turning directions of a vehicle are given when said vehicle approaches said guide intersections, comprising steps of:

determining whether the distance between a present position of the vehicle and a first next guide intersection is less than a first standard distance and a second standard distance which is shorter than the first standard distance;

determining whether a distance between said first next guide intersection and a second next guide intersection immediately subsequent to said first next guide intersection among said guide intersections is less than a third standard distance;

when the distance between the present position of the vehicle and said first next guide intersection is less than the second standard distance, orally outputting said oral instructions with a first additional instruction relating to said second next guide intersection upon approaching said first next guide intersection when the distance between said first next guide intersection and said second next guide intersection is less than said third standard distance; and

orally outputting said oral instructions with a second additional instruction instead of said first additional instruction when the distance between said first next guide intersection and said second next guide intersection is less than a fourth standard distance which is less than said third standard distance, wherein said second additional instruction indicated an urgency of a vehicle maneuver required at said second next guide intersection which urgency is not indicated by said first additional instruction.

4. An oral guidance method for an on-board vehicle navigation system according to claim 3, wherein said first additional instruction is added instead of said second additional instruction when another intersection exists between said first and second next guide intersection even when the distance between said first next guide intersection and said second next guide intersection is less than said fourth standard distance.