Method and system for calculating an energy efficient route

• US 9,506,765 B2
• Filed: 09/06/2013
• Issued: 11/29/2016
• Est. Priority Date: 01/11/2011
• Status: Active Grant

• Current Assignee: HERE Global B.V. (Nokia Corporation)
• Original Assignee: HERE Global B.V. (Nokia Corporation)
• Inventors: Stille, Johannes
• Primary Examiner(s): Mawari, Redhwan K
• Application Number:
  US14/020,234
• Publication Number:
  US 20140005943A1
• Time in Patent Office: 1,180 Days
• US Class Current: 1/1
• CPC Class Codes: G01C 21/3469 Fuel consumption; Energy use; Emission aspects

Abstract

A method and system for calculating an energy efficient route is disclosed. A route calculation application calculates one or more routes from an origin to a destination. For each of the routes, the route calculation application uses segment cost data associated with each segment in the route. The segment cost is calculated by adjusting an energy consumption value by subtracting a bias term for each segment with known slope data. The bias term causes segment costs associated with segments having a slope that can be traveled with typical efficiency, a zero slope, and an unknown slope to be substantially the same. The bias term also causes the segment cost associated with a segment with a slope that can be traveled efficiently to be less than the segment cost associated with a segment with unknown slope, and the segment cost associated with a segment with a slope that causes inefficient travel to be greater than the segment cost associated with a segment with unknown slope.

Claims

1. A method comprising:

receiving data indicative of a destination and an origin; and

displaying, by a navigation system, an energy efficient route from the origin to the destination,

wherein the energy efficient route is generated using a plurality of road segment costs for a plurality of road segments; and

wherein one or more road segments of the plurality of road segments has an unknown slope;

wherein the plurality of road segment costs are calculated by subtracting a bias amount from an energy consumption value of a road segment, wherein the bias amount is equal to the road segment'"'"'s altitude difference multiplied by an energy factor;

wherein the segment cost of the one or more road segments with the unknown slope is equal to the energy consumption value of the one or more road segments.

2. The method of claim 1, wherein the energy factor is based on potential energy stored in a vehicle modeled as traveling the road segment.

3. The method of claim 2, wherein the energy factor is based on a mass of the vehicle.

4. The method of claim 1, wherein the segment cost includes an energy consumption component based on an elevation change for the road segment.

5. The method of claim 1, wherein the energy factor is associated with energy gained by a hybrid vehicle when traveling downhill.

6. The method of claim 1, wherein the energy factor is based on an efficiency of an engine of a vehicle.

7. A method comprising:

accessing a segment cost for a road segment of a plurality of road segments, wherein at least one road segment of the plurality of road has an unknown slope;

performing a comparison of a first elevation of a start of the road segment to a second elevation of an end of the road segment;

calculating a bias amount equal to an absolute value of the road segment'"'"'s altitude difference multiplied by an energy factor;

determining whether the road segment is an uphill segment or a downhill segment based on the comparison of the first elevation to the second elevation;

subtracting, with a processor, the bias amount from the segment cost when the road segment is the uphill segment;

adding, with the processor, the bias amount to the segment cost when the road segment is the downhill segment; and

calculating, by a navigation system, an energy efficient route for a hybrid vehicle based on the energy factor and one or more segment costs for one or more road segments of the plurality of road segments;

displaying, by the navigation system, the energy efficient route.

8. The method of claim 7, wherein the energy factor is based on potential energy stored in a vehicle modeled as traveling the road segment.

9. The method of claim 8, wherein the energy factor is based on a mass of the vehicle.

10. The method of claim 7, wherein the segment cost includes an energy consumption component based on an elevation change for the road segment.

11. The method of claim 7, further comprising:

determining whether the segment cost for the road segment includes an energy consumption component based on the elevation change for the road segment; and

identifying the energy factor in response to the segment cost of the road segment including the energy consumption component.

12. The method of claim 7, wherein the energy factor is associated with energy gained by the hybrid vehicle when traveling downhill.

13. A navigation system comprising:

a user interface configured to receive data indicative of a destination and an origin; and

a map display configured to display an energy efficient route from the origin to the destination, wherein the energy efficient route is determined based on a segment cost for at least one road segment of a plurality of road segments, wherein one or more road segments of the plurality of road segments has an unknown slope;

wherein the segment cost is calculated by subtracting a bias amount from an energy consumption value of the road segment, wherein the bias amount is equal to the road segment'"'"'s altitude difference multiplied by an energy factor;

wherein the segment cost of the one or more road segments with the unknown slope is equal to the energy consumption value of the one or more road segments.

14. The navigation system of claim 13, wherein the road segment is identified as an uphill segment or a downhill segment based on a comparison of a first elevation of a start of the road segment to a second elevation of an end of the road segment.

15. The navigation system of claim 13, wherein the energy consumption value includes a component based on an elevation change for the road segment.

16. The navigation system of claim 13, wherein the energy factor is associated with energy gained by a hybrid vehicle when traveling downhill.

17. The navigation system of claim 13, wherein the energy efficient route is associated with a hybrid vehicle or an electric vehicle configured for regenerative braking.

18. The navigation system of claim 13, wherein the selected route includes at least one segment of unknown slope.