System and method of speed-based downspeed coasting management

• US 9,440,635 B2
• Filed: 05/20/2014
• Issued: 09/13/2016
• 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.
• Primary Examiner(s): SMITH, JELANI A
• Application Number:
  US14/282,874
• Publication Number:
  US 20140336887A1
• Time in Patent Office: 847 Days
• Field of Search: 701/22
• US Class Current: 1/1
• 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 system, comprising:

an internal combustion (IC) engine operably coupled to a vehicle;

a transmission operably coupled to the IC engine, the transmission having a plurality of selectable gears; and

a control module coupled to the IC engine and through a network to the transmission, the control module configured to;

determine a desired deceleration rate;

determine a transmission gear recommendation, the determination of the transmission gear recommendation based on a product of a function of friction of the IC engine and a sum of functions related to vehicle parameters, the functions related to vehicle operating conditions comprising a negative value of each of;

a product of vehicle mass and the desired deceleration rate;

a product of air density, vehicle drag, and a function of a current vehicle speed;

a product of rolling resistance, the vehicle mass, and a first function of road grade; and

a product of the vehicle mass and a second function of the road grade; and

communicate the transmission gear recommendation to a receiver so as to facilitate a gear change.

2. The system of claim 1, wherein the desired deceleration rate is based on a difference between a function of a lower vehicle speed target and the current vehicle speed divided by a function of a distance to coast before reaching the lower vehicle speed target.

3. The system of claim 2, wherein at least one of the current vehicle speed, the lower vehicle speed target, and the distance to coast before reaching the lower vehicle speed target is acquired in real-time through a foresight window of a discrete distance interval.

4. The system of claim 3, wherein the distance interval is predetermined.

5. The system of claim 3, wherein the distance interval is provided by the operator.

6. The system of claim 2, wherein the desired deceleration rate is determined according to the equation

7. The system of claim 1, wherein the transmission gear recommendation is determined according to the equation

8. The system of claim 1, wherein the friction of the IC engine is determined via a look-up table based on at least the current vehicle speed.

9. The system of claim 1, wherein at least one of the current vehicle speed, the lower vehicle speed target, and the distance to coast before reaching the lower vehicle speed target is provided by a vehicle operator.

10. The system of claim 1, wherein the determining of the transmission gear recommendation is further based on vehicle axle loading.

11. The system of claim 1, wherein the control module is further configured to generate an electronic recommendation signal corresponding to the transmission gear recommendation, wherein the transmission gear recommendation is communicated to the receiver via the electronic recommendation signal.

12. The system of claim 11, wherein the receiver is a transmission control unit.

13. The system of claim 11, wherein the receiver is an engine control module.

14. The system of claim 11, wherein the receiver includes a display adapted to indicate the transmission gear recommendation to a vehicle operator.

15. The system of claim 14, wherein the display comprises a touch-screen interface.

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

a communications module; and

a control module coupled to an internal combustion engine, the control module comprising memory having instructions stored therein and at least one processor structured to execute the instructions;

the memory comprising;

a vehicle parameter module containing data indicative of at least one predetermined vehicle parameter, the at least one predetermined vehicle parameter including at least one of vehicle mass, vehicle drag, vehicle rolling resistance, and engine friction;

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

a road terrain element module containing data indicative of at least one road terrain element, the at least one road terrain element including at least one of road grade and air density; and

a downspeed coasting management module;

the instructions comprising instructions for the processor to determine a transmission gear recommendation based on the predetermined vehicle parameter data, the current vehicle operating condition data, the road terrain data and a desired deceleration rate; and

the communications module structured to communicate the transmission gear recommendation to a receiver so as to facilitate a gear change;

wherein the determining of the desired transmission gear recommendation is based on a function of the engine friction;

a product of the vehicle mass and the desired deceleration rate;

a product of the air density, the vehicle drag, and a function of the current vehicle speed;

a product of the rolling resistance, the vehicle mass, and a first function of the road grade; and

a product of the vehicle mass and a second function of the road grade.

17. The system of claim 16, wherein the determining of the desired deceleration rate is based on a difference between a function of the lower vehicle speed target and the current vehicle speed divided by a function of the distance to coast before reaching the lower vehicle speed target.

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

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

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

21. A method performed by a control module comprising at least one memory and at least one processor, the at least one memory storing at least instructions, the at least one processor configured to execute the instructions, the method, comprising:

accessing data indicative of at least one predetermined vehicle parameter, the predetermined vehicle parameter including at least one of vehicle mass, vehicle drag, vehicle rolling resistance, and engine friction;

accessing data indicative of at least one current vehicle operating condition, the vehicle operating condition including current vehicle speed, lower vehicle speed target, and distance to coast before reaching lower vehicle speed target;

accessing data indicative of at least one road terrain element, the at least one road terrain element including at least one of road grade and air density;

determining a desired deceleration rate;

determining a transmission gear recommendation based on;

a function of the engine friction;

a product of the vehicle mass and the desired deceleration rate;

a product of the air density, the vehicle drag, and a function of the current vehicle speed;

a product of the rolling resistance, the vehicle mass, and a first function of the road grade; and

a product of the vehicle mass and a second function of the road grade; and

communicating the transmission gear recommendation to a transmission control unit or an engine control module to effect a gear change.

22. The method of claim 21, wherein the determining of the desired deceleration rate is based on a difference between a function of the lower vehicle speed target and the current vehicle speed divided by a function of the distance to coast before reaching the lower vehicle speed target.

23. The method of claim 21, the operations further comprising disabling the downspeed coasting management program code in response to an operator-initiated event.

24. The method of claim 21, wherein the receiver is a transmission control unit.

25. The method of claim 21, wherein the receiver is an engine control module.

26. The method of claim 21, wherein the receiver includes a display adapted to indicate the transmission gear recommendation to a vehicle operator.