Route Calculation Method for a Vehicle Navigation System

• US 20100121565A1
• Filed: 01/21/2010
• Published: 05/13/2010
• Est. Priority Date: 04/06/2004
• Status: Active Grant

• Current Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Inventors: Ohki, Eric Shigeru, Kurciska, Maja, Tamura, Kazuya, Uyeki, Robert
• Granted Patent: US 7,818,121 B2
• Time in Patent Office: Days
• US Class Current: 701/201
• CPC Class Codes: G01C 21/3415 Dynamic re-routing, e.g. recalculating the route when the user deviates from calculated route or after detecting real-time traffic data or accidents
• CPC Class Codes: G01C 21/3694 Output thereof on a road map
• CPC Class Codes: G08G 1/096811 where the route is computed offboard
• CPC Class Codes: G08G 1/096844 where the complete route is dynamically recomputed based on new data

Abstract

Traffic information, including flow information and incident information, obtained through a traffic management system for providing and facilitating the exchange of traffic information between a remote location and a vehicle may be used in route calculation by a navigation device. The navigation device may recalculate a route based on anticipated user error. Alternatively, the navigation device may recalculate a route using received traffic information triggered by the receipt of a traffic information update, or triggered by the passage of an amount of time. The broadcast rate of traffic information updates may vary temporally (providing more frequent updates during peak commute times) or geographically (providing more frequent updates to metropolitan areas with increased traffic information needs). If route calculation is triggered by an elapsed amount of time, the amount of time may vary to be shorter during peak commute times. Additional route calculation techniques allow the incorporation of historical traffic information or the use of the most recent traffic information if incomplete traffic information is available. Still further route calculation techniques may calculate a best route by avoiding zigzagging or evaluating an assigned cost of a potential route.

Claims

1. In a navigation system having an output screen, a method for reducing the zigzag effect of rerouting a user in a vehicle from an existing route between a first location and a second location, comprising:

calculating an existing route between the first location and the second location;

displaying the calculated existing route in the output screen;

acquiring traffic information from a remote location;

determining whether to reroute the vehicle to a new route based on the acquired traffic information;

calculating the new route based on the acquired traffic information, if it is determined to reroute the vehicle to the new route;

comparing the calculated new route with the existing route between the first location and the second location;

determining a number of times the new route has been rerouted back to the existing route;

continuing to display the existing route in the output screen, if the number of times is more than a predetermined number; and

displaying the new route in the output screen, if the number of times is less than or equal to the predetermined number.

2. The method as recited in claim 1, wherein the predetermined number comprises two.

3. The method as recited in claim 1, wherein the predetermined number comprises between two and five.

4. The method as recited in claim 1, wherein the acquired traffic information is limited to a geographic area that includes the first location and the second location.

5. The method as recited in claim 1, wherein the step of determining whether to reroute the vehicle comprises:

determining whether the acquired traffic information includes a traffic incident;

identifying if the traffic incident is located along the existing route;

determining a severity of the traffic incident; and

determining to reroute the vehicle if the severity is greater than a minimum.

6. The method as recited in claim 1, wherein the step of calculating the new route is based upon at least one factor selected from a list consisting of:

(i) a current position of the vehicle;

(ii) a speed of the vehicle;

(iii) a direction of the vehicle;

(iv) the second location;

(v) a severity of any traffic incidents included in the acquired traffic information;

(vi) a time associated with the acquired traffic information; and

(vii) an estimated time for a traffic incident included in the acquired traffic information to clear.

7. The method as recited in claim 1, wherein the step of determining the number of times the new route has been rerouted back to the existing route comprises determining the number of times calculated within a predetermined distance from a current position of the vehicle.

8. In a navigation system having an output screen, a method for limiting zigzag rerouting of a user in a vehicle from an existing route between a first location to a second location, comprising:

acquiring traffic information from an information supplier, the traffic information gathered from a coverage area that includes the existing route;

identifying whether a reroute condition is present based on the acquired traffic information;

calculating a new route between a current location of the vehicle and the second location, if the reroute condition is present;

comparing the new route with the existing route between the current location and the second location;

determining whether the new route includes one or more portions that are along the existing route;

calculating a number of times the new route is rerouted back to the existing route within a predetermined distance from the current location of the vehicle;

displaying the new route in the output screen, if the number of times is less than or equal to a predetermined number; and

continuing to display the existing route in the output screen, if the number of times is more than the predetermined number.

9. The method as recited in claim 8, wherein the predetermined number comprises two.

10. The method as recited in claim 8, wherein the predetermined number comprises between two and five.

11. The method as recited in claim 8, wherein the step of identifying whether a reroute condition is present further comprises:

determining whether the acquired traffic information includes at least one traffic incident associated with a road on the existing route;

identifying at least one factor associated with the at least one traffic incident; and

determining the reroute condition is present based on the at least one factor.

12. The method as recited in claim 11, wherein the at least one factor is selected from a group consisting of:

(i) the current position of the vehicle;

(ii) a speed of the vehicle;

(iii) a direction of the vehicle;

(iv) the second location;

(v) a severity of the at least one traffic incident;

(vi) a time associated with the acquired traffic information; and

(vii) an estimated time for the at least one traffic incident to clear.

13. The method as recited in claim 11, wherein the step of determining the reroute condition is present based on the at least one factor comprises:

determining a severity of the at least one traffic incident, if the at least one traffic incident is associated with a road on the existing route; and

determining the reroute condition is present if the severity is greater than a minimum.

14. In a navigation system having an output screen, a method for reducing the zigzag effect of rerouting a user in a vehicle from an existing route between a first location and a second location, comprising:

acquiring updated traffic information from a remote location, the traffic information including at least one traffic incident associated with one or more road links included in a coverage area that includes the first location and the second location;

determining whether the at least one traffic incident is associated with at least one of the one or more road links located along the existing route ahead of the vehicle;

calculating a new route based on the updated traffic information, if the at least one traffic incident is associated with the at least one of the one or more road links located along the existing route ahead of the vehicle;

comparing the new route with the existing route between a current position of the vehicle and the second location;

determining a number of times the new route deviates from and subsequently reroutes back to the existing route;

displaying the existing route in the output screen, if the number of times is more than a predetermined number; and

displaying the new route in the output screen, if the number of times is less than or equal to the predetermined number.

15. The method as recited in claim 14, wherein the predetermined number comprises two.

16. The method as recited in claim 14, wherein the predetermined number comprises between two and five.

17. The method as recited in claim 14, wherein the step of determining the number of times the new route deviates from and subsequently reroutes back to the existing route comprises determining the number of times calculated within a predetermined distance from the current position of the vehicle.

18. The method as recited in claim 14, wherein the step of calculating a new route based on the updated traffic information further comprises:

calculating the new route between the current location and the second location using a routing algorithm, and

wherein the routing algorithm comprises a cost function that includes a plurality of cost factors associated with at least one of the one or more road links located along the new route.

19. The method as recited in claim 18, wherein the updated traffic information includes updated cost factors associated with the one or more road links.

20. The method as recited in claim 18, wherein the plurality of cost factors are selected from a group comprising:

(i) a speed of the one or more road links;

(ii) distance from the current location; and

(iii) a road class of the one or more road links.