Vehicle navigation having branch road guidance

• US 6,560,533 B2
• Filed: 04/12/2001
• Issued: 05/06/2003
• Est. Priority Date: 05/10/2000
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Sugawara, Yoshihiko, Sugiura, Wataru
• Primary Examiner(s): Beaulieu, Yonel
• Application Number:
  US09/832,854
• Publication Number:
  US 20010041962A1
• Time in Patent Office: 754 Days
• Field of Search: 701/200, 701/201, 701/208, 701/211, 340/990, 340/995
• US Class Current: 701/211
• 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

Abstract

In a vehicle navigation system, a memory stores branch road numbers as a part of links which indicate branch roads branching out from a main road or a rotary road. The branch road numbers are specific to the branch roads, respectively, and may be exit numbers of an expressway or the rotary road. The branch road numbers are identical with actual indication provided on roadside signboards which indicates respective branch roads. A navigation control unit provides a branching guidance in the course of a normal travel route guidance when a vehicle approaches a branching point. The control unit checks whether a branch road number is available, and retrieves it when available. This retrieved number is provided as a voice message to a driver.

Claims

1. A navigation system comprising:

guidance means for providing a travel route guidance to a destination and a branching guidance when the travel route guidance includes branching of a road from a guided route or through a rotary, the branching guidance being provided upon approaching to a branch road; and

storage means storing a branch road number specific to the branch road and identical with a road number actually displayed on a roadside in correspondence with the branch road,

wherein the guidance means is constructed to retrieve the branch road number from the storage means and indicates the branch road number as the branching guidance.

2. The navigation system as in claim 1, wherein the guidance means is constructed to provide a voice message of the branch road number.

3. The navigation system as in claim 1, wherein the guidance means is constructed to provide a display of the branch road number.

9. A navigation system as in claim 1, wherein the storage means further stores a branch road name specific to the branch road,

wherein the guidance means is further constructed to retrieve the branch road name from the storage means and indicate the branch road name as further branching guidance.

10. A navigation system as in claim 9, wherein the guidance means is constructed to provide a voice message of the branch road name.

11. A navigation system as in claim 9, wherein the guidance means is constructed to provide a display of the branch road name.

4. A navigation system comprising:

display means; and

guidance means for displaying on the display means a travel route guidance to a destination and a branching information including information of a rotary road included in the travel route guidance, the branching information being provided in the order of travel,

wherein the guidance means is constructed to display as the rotary road information a N-th of branch road among branch roads branching out from the rotary road after entering the rotary roads.

12. A navigation system as in claim 4, wherein the guidance means is further constructed to further provide a voice message as the rotary road information regarding the N-th branch road among branch roads branching out from the rotary road after entering the rotary road and upon approaching the N-th branch road.

13. A navigation system as in claim 4, wherein the guidance means is further constructed to further display as the rotary road information a branch road name corresponding to the N-th of branch road among branch roads branching out from the rotary road after entering the rotary road.

5. A navigation system comprising:

display means;

guidance means for displaying a travel route guidance to a destination and a branching information including information of a rotary road included in the travel route guidance, the branching information being provided in the order of travel; and

storage means storing a branch road number specific to a branch road branching out from the rotary road and identical with a road number actually displayed on a roadside in correspondence with the branch road,

wherein the guidance means is constructed to retrieve the branch road number from the storage means and displays the branch road number as information of the rotary road.

14. A navigation system as in claim 5, wherein the storage means further stores a branch road name specific to a branch road branching out from the rotary road corresponding with the branch road,

wherein the guidance means is further constructed to retrieve the branch road name from the storage means and display the branch road name as information of the rotary road.

6. A navigation method for providing a travel route guidance to a destination and a branching guidance for indicating a branch road to be taken from a presently traveling road in the course of the travel route guidance, the method comprising the steps of:

checking whether an exit number which is specific to the branch road to be taken is available in a road map data stored in a memory, the exit number being identical with a number actually indicated on a roadside;

retrieving the exit number from the memory if available in the memory; and

indicating the retrieved exit number in a vehicle.

7. The navigation method as in claim 6, wherein the indicating step includes a step of providing a voice message indicating the retrieved exit number.

8. A computer-readable program which stores the road map data and the steps of claim 6.

15. A navigation method as in claim 6;

further including checking, when the exit number is not available, whether a name that is specific to the branch road to be taken is available in data stored in memory, retrieving the name, if available in the memory, and indicating the name in the vehicle.

16. A navigation method as in claim 15, wherein the indicating the name includes providing a voice message indicating the name.

17. A navigation method as in claim 15, further including, when the name is not available, indicating an exit to be taken in relative terms.

18. A navigation method as in claim 17 further including providing a voice message indicating the exit to be taken in relative terms upon approaching the exit to be taken.