Route navigation with optimal speed profile

• US 9,081,651 B2
• Filed: 03/13/2013
• Issued: 07/14/2015
• Est. Priority Date: 03/13/2013
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Filev, Dimitar P., Michelini, John O., Szwabowski, Steven J., McNeille, Perry R., Di Cairano, Stefano
• Primary Examiner(s): Nguyen, Kim T
• Application Number:
  US13/799,934
• Publication Number:
  US 20140277835A1
• Time in Patent Office: 853 Days
• Field of Search: 701/2, 701/36, 701/37, 701/65, 701/70, 701/93, 701/96, 701/99, 701/408, 701/410, 701/415, 701/123
• US Class Current: 1/1
• CPC Class Codes: B60K 2310/24 Speed setting methods
• CPC Class Codes: B60K 31/00 Vehicle fittings, acting on a single sub-unit only, for automatically controlling vehicle speed, i.e. preventing speed from exceeding an arbitrarily established velocity or maintaining speed at a particular velocity, as selected by the vehicle operator fittings acting on two or more sub-units B60W30/14; speedometers G01P; systems or devices for controlling speed in general G05D13/00 ; in traffic anti-collision system for road vehicles G08G1/16
• CPC Class Codes: G01C 21/3469 Fuel consumption; Energy use; Emission aspects
• CPC Class Codes: G06F 17/00 Digital computing or data processing equipment or methods, specially adapted for specific functions information retrieval, database structures or file system structures therefor G06F16/00
• CPC Class Codes: Y02T 10/84 Data processing systems or methods, management, administration

Abstract

Energy consumption of a vehicle is optimized while traveling a route assembled of road segments between a first position and a destination. A speed profile generator is located at least partially off of the vehicle and uses an energy consumption model of the vehicle together with road grade data corresponding to the route to calculate an optimal speed profile. The speed profile specifies target speeds for respective locations on the route for traversing the route with an optimized energy consumption. The speed profile generator compares energy consumption for a plurality of feasible speed profile trajectories between a maximum trajectory and a minimum trajectory in order to identify the optimal speed profile. A speed updater is responsive to a current position of the vehicle and the optimal speed profile to initiate the target speed for the current position.

Claims

1. A system for optimizing energy consumption of a vehicle, comprising:

a route calculator for assembling road segments into a route from a first position to a destination;

a speed profile generator located at least partially off of the vehicle and using an energy consumption model of the vehicle together with road grade data corresponding to the route to calculate an optimal speed profile that specifies target speeds for respective locations on the route for traversing the route with an optimized energy consumption, wherein the speed profile generator compares energy consumption for a plurality of feasible speed profile trajectories between a maximum trajectory and a minimum trajectory in order to identify the optimal speed profile; and

a speed updater responsive to a current position of the vehicle and the optimal speed profile to initiate a target speed specified for the current position.

2. The system of claim 1 wherein the speed profile generator periodically updates the optimal speed profile while traversing the route.

3. The system of claim 1 wherein the speed updater is comprised of an adaptive cruise control system that uses the target speed for the current position as a speed setpoint.

4. The system of claim 1 wherein the speed updater is comprised of an HMI device for indicating to a driver the target speed or a speed change to be made to obtain the target speed.

5. The system of claim 4 wherein the HMI device is a graphic display showing a numeric value of the target speed.

6. The system of claim 4 wherein the HMI device is a graphic display having a visual characteristic for indicating whether a speed increase or a speed decrease is required to obtain the target speed.

7. The system of claim 1 wherein the speed profile generator determines the maximum trajectory in response to a legal speed limit corresponding to the road segments.

8. The system of claim 1 wherein the speed profile generator determines the minimum trajectory in response to traffic control stops along the road segments.

9. The system of claim 1 further comprising a wireless data transceiver in the vehicle for communicating with a remote server, wherein the remote server includes at least a portion of the speed profile generator.

10. The system of claim 9 further comprising an energy consumption monitor generating energy usage data resulting from the optimal speed profile, wherein the energy usage data is sent by the wireless data transceiver to the remote server so that the speed profile generator refines the energy consumption model.

11. The system of claim 1 wherein the route calculator includes an input device for use by a driver to identify the destination.

12. The system of claim 1 wherein the route calculator includes:

a location tracking device for monitoring the current position of the vehicle; and

a recognition unit storing routes commonly traversed by the vehicle and comparing a current path of the vehicle to the stored routes to select a current route.

13. The system of claim 1 wherein the route calculator assembles the road segments into the route in response to evaluating optimized energy consumption calculated for a plurality of possible routes between the first position and the destination.

14. The system of claim 1 wherein the energy consumption model calculates the optimal speed profile further in response to route conditions selected from the group of traffic density, weather conditions, road surface conditions, altitude, transmission shift schedule, and torque converter operation.

15. The system of claim 1 wherein the optimal speed profile further specifies transmission settings.

16. The system of claim 1 wherein the optimal speed profile further specifies suspension settings.

17. The system of claim 1 wherein the route calculator determines a plurality of frequently-traveled routes based on a history of a vehicle location, time of day, and driving conditions, wherein the speed profile generator calculates a respective optimal speed profile for the frequently traveled routes, wherein the optimal speed profiles are downloaded to the vehicle, and wherein the speed updater uses one of the downloaded optimal speed profiles in response to detecting travel of the vehicle along one of the frequently-traveled routes at a corresponding time of day and driving conditions.

18. A method for optimizing energy consumption of a vehicle, comprising:

assembling road segments in a navigation system into a route from a first position to a destination;

evaluating an energy consumption model of the vehicle together with road grade data corresponding to the route to calculate an optimal speed profile that specifies target speeds for respective locations on the route for traversing the route with an optimized energy consumption, wherein energy consumption is compared for a plurality of feasible speed profile trajectories between a maximum trajectory and a minimum trajectory in order to identify the optimal speed profile, wherein the evaluating is performed off of the vehicle by a remote server, and wherein the vehicle communicates wirelessly with the remote server to receive the optimal speed profile;

indicating to a driver on an HMI device a specified target speed or a speed change to be made to obtain the specified target speed in response to a current position of the vehicle and the optimal speed profile;

,

determining an acceptance rate of the target speed by a driver by comparing an actual speed with an acceptance zone around the target speed in a processor; and

if the determined acceptance rate is below a threshold, then recalculating the optimal speed profile using revised maximum and minimum trajectories that are selected to increase the acceptance rate.

19. The method of claim 18 wherein the optimal speed profile is periodically updated while traversing the route.

20. The method of claim 18 wherein the initiating step is comprised of displaying a numeric value of the target speed.

21. The method of claim 18 wherein the initiating step is comprised of displaying a visual characteristic for indicating whether a speed increase or a speed decrease is required to obtain the target speed.

22. The method of claim 18 wherein the acceptance rate R(k) is successively determined for each successive target speed k according to a formula:

R(k)=(1−

α

)R(k−

1)+α

if ν

_min<

ν

(k)<

ν

_max, and

R(k)=(1−

α

)R(k−

1) if ν

(k)<

ν

_min or ν

(k)>

ν

_max

where α

is a constant forgetting factor, 0<

α

≦

1, ν

(k) is the actual speed, and ν

_min and ν

_max define an the acceptance zone around the target speed.

23. The method of claim 20 wherein the maximum trajectory is determined in response to a legal speed limit corresponding to the road segments.

24. The method of claim 18 wherein the minimum trajectory is determined in response to traffic control stops along the road segments.

25. The method of claim 18 further comprising the steps of:

monitoring the energy consumption to generate energy usage data resulting from the vehicle using the optimal speed profile;

wirelessly sending the energy usage data to the remote server; and

refining the energy consumption model in response to the energy usage data.

26. The method of claim 18 further comprising the step of a driver manually inputting the destination.

27. The method of claim 18 further comprising the steps of:

tracking the current position of the vehicle; and

comparing a current path of the vehicle to a plurality of stored routes commonly traversed by the vehicle to select the current route.

28. The method of claim 18 wherein the road segments assembled into the route are selected in response to evaluating optimized energy consumption calculated for a plurality of possible routes between the first position and the destination.

29. The method of claim 18 wherein the energy consumption model calculates the optimal speed profile further in response to route conditions selected from the group of traffic density, weather conditions, road surface conditions, altitude, transmission shift schedule, and torque converter operation.

30. The method of claim 18 wherein the optimal speed profile further specifies transmission settings.

31. The method of claim 18 wherein the optimal speed profile further specifies suspension settings.

32. The method of claim 18 wherein assembling the route includes determining a plurality of frequently-traveled routes based on a history of a vehicle location, time of day, and driving conditions, wherein a plurality of optimal speed profiles are calculated for the frequently traveled routes, and wherein the method further comprises the step of detecting travel of the vehicle along one of the frequently-traveled routes at a corresponding time of day and driving conditions and selecting the corresponding optimal speed profile to determine the target speed.

33. A system for optimizing energy consumption of a vehicle, comprising:

a route calculator for assembling road segments into a route from a first position to a destination;

a speed profile generator located at least partially off of the vehicle and using an energy consumption model of the vehicle together with road grade data corresponding to the route to calculate an optimal speed profile that specifies target speeds for respective locations on the route for traversing the route with an optimized energy consumption, wherein the speed profile generator compares energy consumption for a plurality of feasible speed profile trajectories between a maximum trajectory and a minimum trajectory in order to identify the optimal speed profile;

a speed updater responsive to a current position of the vehicle and the optimal speed profile to initiate a target speed specified for the current position, the speed updater is comprised of an HMI device for indicating to a driver the target speed or a speed change to be made to obtain the target speed; and

a monitor for determining an acceptance rate of the target speed by the driver;

wherein, if the determined acceptance rate is below a threshold, then the speed profile generator recalculates the optimal speed profile using revised maximum and minimum trajectories that are selected to increase the acceptance rate.

34. The system of claim 33 wherein the acceptance rate R(k) is successively determined for each successive target speed k according to a formula:

R(k)=(1−

α

)R(k−

1)+α

if ν

_min<

ν

(k)<

ν

_max, and

R(k)=(1−

α

)R(k−

1) if ν

(k)<

ν

_min or ν

(k)>

ν

_max

where α

is a constant forgetting factor, 0<

α

≦

1, ν

(k) is the actual speed, and ν

_min and ν

_max define an acceptance zone around the target speed.