SYSTEM AND METHOD OF SPEED-BASED DOWNSPEED COASTING MANAGEMENT

• US 20120197500A1
• Filed: 12/23/2011
• Published: 08/02/2012
• Est. Priority Date: 12/23/2010
• Status: Active Grant

• Current Assignee: Cummins Intellectual Property, Inc. (Cummins Incorporated)
• Original Assignee: Cummins Intellectual Property, Inc. (Cummins Incorporated)
• Inventors: Sujan, Vivek A., Vajapeyazula, Phani, Follen, Kenneth, Wu, An, Moffett, Barty L., Frost, Howard R.
• Granted Patent: US 8,731,788 B2
• Time in Patent Office: Days
• US Class Current: 701/51
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/11 Stepped gearings
• CPC Class Codes: B60W 2030/18081 With torque flow from driveshaft to engine, i.e. engine being driven by vehicle
• CPC Class Codes: B60W 2530/10 Weight
• CPC Class Codes: B60W 2530/16 Driving resistance
• CPC Class Codes: B60W 2552/15 Road slope, i.e. the inclination of a road segment in the longitudinal direction
• CPC Class Codes: B60W 2552/20 Road profile, i.e. the change in elevation or curvature of a plurality of continuous road segments
• CPC Class Codes: B60W 50/0097 Predicting future conditions
• CPC Class Codes: Y02T 10/60 Other road transportation technologies with climate change mitigation effect
• CPC Class Codes: Y02T 10/84 Data processing systems or methods, management, administration

Abstract

A velocity profile can be used in conjunction with vehicle operating condition data to determine a gear shift schedule that mitigates the amount of service brake effort required to slow a vehicle by making optimal use of engine speed, friction and engine brakes. The gear shift point drives the engine to a higher operating speed and greater frictional torque, slowing the vehicle, which can then coast to a desired speed. The gear shift point can be timed to minimize fuel consumption during the maneuver. Thus, a vehicle downshift event is created based on the transmission gear recommendation. The benefit is increased freight efficiency in transporting cargo from source to destination by minimizing fuel consumption and maintaining drivability.

Claims

1. A method for downspeed coasting management for a vehicle, comprising:

accessing predetermined vehicle parameter data indicative of at least one predetermined vehicle parameter, said at least one predetermined vehicle parameter including at least one of vehicle mass, vehicle drag, vehicle rolling resistance, tire circumference, front area of vehicle, powertrain torque loss, and engine friction;

accessing current vehicle operating data indicative of at least one current vehicle operating condition, said at least one current vehicle operating condition including current vehicle speed, a lower vehicle speed target to be reached, and a distance to travel before reaching the lower vehicle speed target;

accessing road terrain data indicative of at least one road terrain element, said at least one road terrain element including at least one of speed limit changes, off ramp locations, fueling locations, road grade, air density and traffic congestion;

determining a desired rate of deceleration based on said current vehicle speed, lower vehicle speed target to be reached, and the distance to travel before reaching the lower vehicle speed target; and

determining a transmission gear recommendation based on said predetermined vehicle parameter data, said current vehicle operating data, said road terrain data and said desired rate of deceleration.

2. The method of claim 1, further comprising generating an electronic recommendation signal corresponding to said transmission gear recommendation and communicating said transmission gear recommendation to a receiver.

3. The method of claim 2, wherein said receiver is a transmission control unit.

4. The method of claim 2, wherein said receiver is an engine control module.

5. The method of claim 2, wherein said receiver is a display adapted to indicate the transmission gear recommendation to a vehicle operator.

6. The method of claim 5, wherein said display comprises a touch-screen interface.

7. The method of claim 1, wherein at least one of said data indicative of at least one current vehicle operating condition is provided by a vehicle operator.

8. The method of claim 1, wherein said at least one predetermined vehicle parameter further comprises vehicle axle loading.

9. The method of claim 1, wherein said determining a desired rate of deceleration comprises determining a difference between a function of said lower vehicle speed target to be reached and said current vehicle speed over a function of said distance to travel before reaching the lower vehicle speed target to be reached.

10. The method of claim 9, wherein said determining a transmission gear recommendation comprises determining a difference between a product of said vehicle mass and said desired rate of deceleration and a product of said air density and said vehicle drag and a function of said current vehicle speed and a product of said rolling resistance and said vehicle mass and a first function of said grade and a product of said vehicle mass and a second function of said grade applied as a product against a function of said engine friction.

11. The method of claim 1, wherein said current vehicle operating data is acquired in real-time through a foresight window of a discrete distance interval.

12. The method of claim 11, wherein said distance interval is predetermined.

13. The method of claim 11, wherein said distance interval is provided by the operator.

14. The method of claim 1, wherein said desired rate of deceleration is determined according to the equation

15. The method of claim 14, wherein said transmission gear recommendation is determined according to the equation

16. A system adapted for downspeed coasting management for a vehicle, comprising:

a vehicle parameter module containing data indicative of at least one predetermined vehicle parameter, said at least one predetermined vehicle parameter including at least one of vehicle mass, vehicle drag, vehicle rolling resistance, tire circumference, front area of vehicle, powertrain torque loss, and engine friction;

a vehicle operating condition module containing data indicative of at least one current vehicle operating condition, said at least one current vehicle operating condition including current vehicle speed, a lower vehicle speed target to be reached, and a distance to travel before reaching the lower vehicle speed target;

a road terrain element module containing data indicative of at least one road terrain element, said at least one road terrain element including at least one of speed limit changes, off ramp locations, fueling locations, road grade, air density and traffic congestion;

a downspeed coasting management module adapted to determine a desired rate of deceleration based on said current vehicle speed, lower vehicle speed target to be reached, and the distance to travel before reaching the lower vehicle speed target, and further adapted to determine a transmission gear recommendation based on said predetermined vehicle parameter data, said current vehicle operating condition data, said road terrain data and said desired rate of deceleration.

17. The system of claim 16, wherein said downspeed coasting management module is adapted to generate an electronic recommendation signal corresponding to said transmission gear recommendation.

18. The system of claim 17, further including a receiver adapted to receive said electronic recommendation signal.

19. The system of claim 18, wherein said receiver is a transmission control unit.

20. The system of claim 18, wherein said receiver is an engine control module.

21. The system of claim 18, wherein said receiver is a display.

22. The system of claim 21, wherein said display comprises a touch-screen interface.

23. The system of claim 16, wherein at least one of said data indicative of at least one current vehicle operating condition is provided by a vehicle operator.

24. The system of claim 16, wherein said at least one predetermined vehicle parameter further comprises vehicle axle loading.

25. The system of claim 16, wherein said determining a desired rate of deceleration comprises determining a difference between a function of said lower vehicle speed target to be reached and said current vehicle speed over a function of said distance to travel before reaching the lower vehicle speed target to be reached.

26. The system of claim 25, wherein said determining a transmission gear recommendation comprises determining a difference between a product of said vehicle mass and said desired rate of deceleration and a product of said air density and said vehicle drag and a function of said current vehicle speed and a product of said rolling resistance and said vehicle mass and a first function of said grade and a product of said vehicle mass and a second function of said grade applied as a product against a function of said engine friction.

27. A computer program product comprising a computer useable medium having stored thereon computer-readable program code for downspeed coasting management for a vehicle, the computer-readable program code comprising:

computer-readable program code for accessing data indicative of at least one predetermined vehicle parameter, said predetermined vehicle parameter including at least one of vehicle mass, vehicle drag, rolling resistance, tire circumference, front area of vehicle, powertrain torque loss, and engine friction;

computer-readable program code for accessing data indicative of at least one current vehicle operating condition, said vehicle operating condition including current vehicle speed, lower vehicle speed target to be reached, and distance to travel before reaching lower vehicle speed target to be reached;

computer-readable program code for accessing data indicative of at least one road terrain element, said at least one road terrain element including at least one of speed limit changes, off ramp locations, fueling locations, road grade, air density and traffic congestion;

computer-readable program code for determining a desired rate of deceleration comprising determining a difference between a function of said lower vehicle speed target to be reached and said current vehicle speed over a function of said distance to travel before reaching the lower vehicle speed target to be reached;

computer-readable program code for determining a transmission gear recommendation comprising determining a difference between a product of said vehicle mass and said desired rate of deceleration and a product of said air density and said vehicle drag and a function of said current vehicle speed and a product of said rolling resistance and said vehicle mass and a first function of said grade and a product of said vehicle mass and a second function of said grade applied as a product against a function of said engine friction; and

computer-readable program code for communicating said transmission gear recommendation to a receiver.

28. The computer program product of claim 27, further comprising computer-readable program code for disabling the downspeed coasting management program code in response to an operator-initiated event.