Navigation system and program for controlling the same

• US 20060167626A1
• Filed: 01/17/2006
• Published: 07/27/2006
• Est. Priority Date: 01/24/2005
• Status: Abandoned Application

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Hashizume, Masayuki
• Application Number:
  US11/332,354
• Publication Number:
  US 20060167626A1
• Time in Patent Office: Days
• US Class Current: 701/210
• CPC Class Codes: G01C 21/3691 Retrieval, searching and output of information related to real-time traffic, weather, or environmental conditions arrangements for giving variable traffic instructions G08G1/09
• CPC Class Codes: G08G 1/096827 where the route is computed onboard
• CPC Class Codes: G08G 1/096844 where the complete route is dynamically recomputed based on new data

Abstract

A navigation system includes a congestion information acquisition function, a congestion determination function, a speed determination function, a calculation function, and a display function for navigating a vehicle. The navigation system uses these functions for determination of traffic congestion on a road and for calculation of an alternative route to a destination.

Claims

1. A navigation system for use in a subject vehicle that organizes a navigation route toward a destination by connecting nodes with links in map data as a route guidance comprising:

a congestion information acquisition means for acquiring information of traffic congestion in a link;

a first determination means for determining one of following two conditions of the subject vehicle, wherein the information of traffic congestion of a current link where the subject vehicle is traveling is acquired by the congestion information acquisition means as a first condition, and the information of traffic congestion of the current link has not been acquired as a second condition;

a second determination means for determining that traveling speed of the subject vehicle in the current link is within a predetermined range of value;

a calculation means for calculating an alternative route toward the destination from an end node of the current link; and

a display means for displaying the alternative route on a display device based on combination of determinations by the first determination means and the second determination means.

2. The navigation system according to claim 1 further comprising:

a position determination means for determining that quantity of remoteness of the subject vehicle from the end node of the current link is within a predetermined range,

wherein the display means displays the alternative route toward the destination based on combination of determinations by the first determination means, the second determination means and the position determination means.

3. The navigation system according to claim 2 further comprising:

a switching means for switching the route guidance from the navigation route to the alternative route being displayed on the display device,

wherein the switching means switches the route guidance to the alternative route before the subject vehicle departs from the navigation route.

4. A computer program stored in a computer-readable medium having computer program logic recorded thereon for enabling control of a navigation system that organizes map data including a plurality of nodes and connecting links for route guidance comprising:

a congestion information obtaining procedure for obtaining information of traffic congestion in a link;

a first determination procedure for determining one of following two conditions, wherein the information of traffic congestion of a current link where the subject vehicle is traveling has been obtained by the congestion information obtaining procedure as a first condition, and the information of traffic congestion in the current link has not been obtained as a second condition;

a second determination procedure for determining that traveling speed of the subject vehicle in the current link is in a predetermined range of value;

a calculation procedure for calculating an alternative route toward the destination from an end node of the current link; and

a display procedure for displaying the alternative route on a display device based on combination of determinations by the first determination procedure and the second determination procedure.

5. A method for controlling a navigation system in a vehicle for route navigation that leads to a destination through a guidance point comprising steps of:

obtaining either traffic information on congestion in a section of a navigation route or absence of the traffic information;

detecting speed of the vehicle;

calculating an alternative route toward the destination; and

displaying the alternative route on a display device,

wherein the alternative route is displayed on the display device when determinations in the steps indicates that the traffic information on congestion indicates one of no congestion in the section of the navigation route and absence of the traffic information, and that the speed of the vehicle is within a predetermined range of value.

6. The method according to claim 5 further comprising a step of:

determining a distance from the vehicle to the guidance point,

wherein the alternative route is displayed on the display device when the distance is equal to or greater than a predetermined range of value.

7. The method according to claim 6 further comprising a step of:

switching the navigation route to the alternative route,

wherein the navigation route is switched to the alternative route before the vehicle departs from the navigation route.