Vehicle-mounted device, traffic-information acquisition method, traffic-information provision system, and traffic-information provision method

• US 8,036,820 B2
• Filed: 06/19/2007
• Issued: 10/11/2011
• Est. Priority Date: 06/30/2006
• Status: Expired due to Fees

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Sera, Manabu
• Primary Examiner(s): Tran; Khoi
• Assistant Examiner(s): PECHE, JORGE O
• Application Number:
  US11/764,840
• Publication Number:
  US 20080004791A1
• Time in Patent Office: 1,575 Days
• Field of Search: 701/117, 701/118, 701/119, 701/201, 701/202, 701/206, 701/209, 701/210, 370/237, 370/238, 340/905, 340/917, 340/991, 340/993, 340/994, 340/995.13, 340/995.21, 340/995.19
• US Class Current: 701/117
• 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
• CPC Class Codes: G08G 1/096866 where the complete route is shown to the driver

Abstract

When a change occurs between a previous traffic condition based on traffic information provided previously and the current traffic condition, a control unit of a vehicle-mounted device performs control such that traffic information is acquired from an external device via wireless communication. A comparison of current vehicle traveling conditions and previous vehicle traveling conditions can also be used to determine whether traffic information should be updated.

Claims

1. A vehicle-mounted device that acquires traffic information for a vehicle, comprising:

a traffic-information acquisition unit configured to automatically acquire traffic information from a first source of traffic information, said first source configured to provide traffic information via wireless communication; and

a controller configured to;

responsive to a request from a driver to set a destination for the vehicle, control the traffic-information acquisition unit to acquire traffic information from an external second source of traffic information, the second source having at least certain traffic information not available from the first source and configured to provide traffic information to the traffic-information acquisition unit;

calculate a route to the destination using the traffic information from the first source and the second source;

during guidance along the route, control the traffic-information acquisition unit to acquire current traffic information from the second source only if a value of at least one of a change between a current traffic condition along the route and a previous traffic condition along the route or between a previous traveling condition of the vehicle and a current traveling condition of the vehicle is larger than a predetermined threshold, the previous traffic condition based on previously-provided traffic information; and

recalculate the route to the destination using at least one of the current traffic information, the current traveling condition of the vehicle or the current traffic condition along the route if the traffic-information acquisition unit acquires the current traffic information.

2. The device according to claim 1, further comprising:

a comparator configured to determine, at predetermined intervals, the value of the change between the current traffic condition along the route and the previous traffic condition along the route;

wherein the comparator is part of the controller; and

wherein the controller, during guidance along the route, controls the traffic-information acquisition unit to acquire the current traffic information from the second source only if the value of the change between the current traffic condition along the route and the previous traffic condition along the route is larger than a first predetermined threshold.

3. The device according to claim 1 wherein the current traffic condition and the previous traffic condition include a degree of traffic congestion as a traffic condition.

4. The device according to claim 1, further comprising:

a comparator configured to determine, at predetermined intervals, the value of the change between the previous traveling condition of the vehicle and the current traveling condition of the vehicle; and

wherein the controller, during guidance along the route controls the traffic-information acquisition unit to acquire the current traffic information from the second source only if the value of the change between the previous traveling condition of the vehicle and the current traveling condition of the vehicle is larger than a second predetermined threshold; and

wherein the comparator is part of the controller.

5. The device according to claim 4, further comprising:

a current-position detector configured to detect a current position of the vehicle; and

wherein the current traveling condition is based on traffic information provided from at least one of the first source or the current position detected by the current-position detector.

6. The device according to claim 1 wherein the previous traffic condition is a first degree of traffic congestion at a first period of time, the current traffic condition is a second degree of traffic congestion at a later, second period of time, and the value of the change is a difference between the first degree of traffic congestion and the second change in the degree of traffic congestion.

7. The device according to claim 1 wherein the controller is configured to transmit a current position of the vehicle to the second source in response to a request from the second source generated when the value of the change between the current traffic condition along the route and the previous traffic condition along the route is larger than the predetermined threshold.

8. The device according to claim 7 wherein the current traffic information sent from the second source is based on the current position of the vehicle.

9. The device according to claim 1 wherein the controller is configured to control the traffic-acquisition unit to transmit a request for the current traffic information to the second source only if the value of at least one of the change between the current traffic condition along the route and the previous traffic condition along the route or the previous traveling condition of the vehicle and the current traveling condition of the vehicle is larger than the predetermined threshold.

10. The device according to claim 1 wherein the controller is configured to control the traffic-acquisition unit to transmit a request for the current traffic information to the second source only if the value of each of the change between the current traffic condition along the route and the previous traffic condition along the route is larger than a first predetermined threshold and between the previous traveling condition of the vehicle and the current traveling condition of the vehicle is larger than a second predetermined threshold.

11. The device according to claim 1 wherein the first source is a free source of traffic information and the second source is a fee-based source of traffic information.

12. A traffic-information provision system for providing traffic information to a vehicle-mounted device, the system comprising:

a first source of traffic information configured to automatically provide traffic information to the vehicle-mounted device via wireless communication;

an external second source of traffic information configured to provide traffic information to the vehicle-mounted device via wireless communication, the second source having at least certain traffic information not available from the first source; and

a controller of the vehicle-mounted device configured to;

responsive to a request from a driver to set a destination for the vehicle, control the traffic-information acquisition unit to calculate a route to the destination using traffic information from the first source and the second source;

follow the route to the destination based on current traffic information from the first source;

monitor at least one of traffic conditions along the route or traveling conditions of the vehicle while following the route; and

control the second source to provide updated current traffic information to the vehicle-mounted device while following the route only when a change occurs between at least one of a current traffic condition and a previous traffic condition along the route or a current traveling condition of the vehicle and a previous traveling condition of the vehicle that is larger than a predetermined threshold, the previous traffic condition based on previously-provided traffic information used to calculate the route.

13. The system according to claim 12 wherein the controller is configured to control the second source to provide the updated current traffic information to the vehicle-mounted device responsive to a value obtained from a comparator comparing the previous traffic condition and the current traffic condition being larger than the predetermined threshold.

14. The system according to claim 12 wherein the current traffic condition and the previous traffic condition are based on a degree of traffic congestion.

15. The system according to claim 12 wherein the controller is configured to:

control the second source to provide the updated current traffic information to the vehicle-mounted device responsive to a value obtained by a comparison between a previous traveling condition and a current traveling condition of the vehicle including the vehicle-mounted device being larger than the predetermined threshold.

16. A traffic-information acquisition method for use with a vehicle-mounted device of a vehicle, the method comprising:

following a route to a destination using a controller of the vehicle-mounted device based on traffic information automatically retrieved from a first source of traffic information configured to provide traffic information via wireless communication and retrieved from an external second source of information acquired in response to a request of a driver of the vehicle to set the destination of the vehicle, the second source having at least certain traffic information not available from the first source and configured to provide traffic information to the vehicle-mounted device;

monitoring at least one of traffic conditions along the route or traveling conditions of the vehicle while following the route;

determining at predetermined intervals at least one of a change between a current traffic condition and a previous traffic condition along the route or between a current traveling condition and a previous traveling condition of the vehicle, the previous traffic condition based on previously-provided traffic information; and

acquiring current traffic information from the second source via wireless communication while following the route only when a value of the change is larger than a predetermined threshold.

17. The method according to claim 16 wherein the previous traffic condition and the current traffic condition are based on a degree of traffic congestion

18. The method according to claim 16, further comprising:

calculating a revised route to the destination using the controller based on the current traffic information from the second source when the value of the change is larger than the predetermined threshold.

19. The method according to claim 18 wherein the previous traffic condition is a first degree of traffic congestion at a first period of time, the current traffic condition is a second degree of traffic congestion at a later, second period of time, and the change is a difference between the first degree of traffic congestion and the second change in the degree of traffic congestion.

20. The method according to claim 18 wherein the previous traffic condition is a first amount of travel time to the destination at a first period of time, the current traffic condition is a second amount of travel time to the destination at a later, second period of time, and the change is a difference between the first amount of travel time and a second amount of travel time.