Powertrain controls including transient torque management with dynamic release compensation

Patent metadata

Field	Value
Publication number	US-9707968-B2
Application number	US-201414456681-A
Country	US
Kind code	B2
Filing date	Aug 11, 2014
Priority date	Aug 11, 2014
Publication date	Jul 18, 2017
Grant date	Jul 18, 2017

Abstract

One exemplary embodiment is a method of controlling a vehicle system including an engine, a transmission, and a control system in operative communication with and structured to control operation of the engine and the transmission. The method determines an operating point of the engine including an engine torque and an engine speed and evaluates a relationship between the operating point and a soft limit on engine torque. The method modifies the soft limit to permit operation outside a boundary of the un-modified soft limit. Modification of the soft limit is constrained by a non-adjustable limit. The operating point of the engine is adjusted to increase engine torque above the boundary of the un-modified soft limit. The method may mitigate a vehicle speed lug event and/or avoid a transmission shift event.

First claim

What is claimed is:

1. A method of controlling a vehicle system including an engine, a transmission, and a control system in operative communication with and structured to control operation of the engine and the transmission, the method comprising:
determining an operating point of the engine, the operating point including an engine torque and an engine speed;
evaluating a relationship between the operating point and a soft limit on engine torque;
modifying the soft limit to permit operation outside a boundary of the un-modified soft limit, the modifying the soft limit being constrained by a hard limit on engine torque, the act of modifying the soft limit including
determining a dynamic torque limit using estimated vehicle operation parameters and a feedback loop which adjusts the estimated vehicle operation parameters using actual system response information and feedback of the dynamic torque limit,
determining a static torque limit using a predetermined table,
and selecting the minimum of the static torque limit and the dynamic torque as an input for determining a value of the modified soft limit, the act of selecting the minimum occurring irrespective of an engine speed; and

adjusting the operating point of the engine to increase engine torque above the boundary of the un-modified soft limit, based upon a weighted optimization of a demand responsiveness criterion and a fuel consumption criterion, the weighting of the fuel consumption criterion being dynamically adjustable;
wherein the modifying and the adjusting are effective to at least one of mitigate a vehicle speed lug event and avoid a transmission shift event.

2. The method of claim 1 wherein the adjusting the operating point comprises a combination of increasing engine torque above the un-modified soft limit and decreasing engine speed.

3. The method of claim 1 further comprising reinstating the un-modified soft limit on engine torque based upon a reinstatement criterion.

4. The method of claim 1 wherein the modifying the soft limit is based at least in part upon a predetermined relationship between the operating point of the engine and the soft limit on engine torque.

5. A method of controlling a vehicle system including an engine, a transmission, and a control system in operative communication with and structured to control operation of the engine and the transmission, the method comprising:
determining an operating point of the engine, the operating point including an engine torque and an engine speed;
evaluating a relationship between the operating point and a soft limit on engine torque;
modifying the soft limit to permit operation outside a boundary of the un-modified soft limit, the modifying the soft limit being constrained by a hard limit on engine torque; and
adjusting the operating point of the engine to increase engine torque above the boundary of the un-modified soft limit,
wherein the modifying and the adjusting are effective to at least one of mitigate a vehicle speed lug event and avoid a transmission shift event, and
the modifying the soft limit is based upon a predicted future engine operating point and a dynamically adjustable weighted optimization of a demand responsiveness criterion and a fuel consumption criterion.

6. The method of claim 5 wherein the predicted future operating point is based at least in part upon information of a global positioning system.

7. The method of claim 5 wherein the predicted future operating point is based at least in part upon information of prior operation of the vehicle.

8. The method of claim 5 wherein the predicted future operating point is based at least in part upon a predetermined road parameter specification.

9. The method of claim 5 wherein the predicted future operating point is based at least in part upon information from an inclinometer.

10. The method of claim 5 wherein the predicted future operating point is based at least in part upon a forward horizon terrain profile.

11. The method of claim 5 wherein the predicted future operating point is based at least in part upon information from an inclinometer and a forward horizon terrain profile.

12. The method of claim 11 wherein the information from the inclinometer and the forward horizon terrain profile are utilized to determine a fused grade sensor value.

13. The method of claim 12 wherein the fused grade sensor value comprises a weighted average of the information from the inclinometer and the forward horizon terrain profile.

14. A vehicle system comprising:
an engine;
a transmission; and
a control system in operative communication with the engine and the transmission, the control system being structured to:
determine an operating point of the engine, the operating point including an engine torque and an engine speed,
evaluate a relationship between the operating point and a first limit on engine torque,
modify the first limit to permit operation outside a boundary of the un-modified first limit, modification of the first limit being constrained by a second limit on engine torque, a modified magnitude of the first limit being determined by selecting a lesser one of a static torque limit and a dynamic torque limit, the act of selecting the minimum being uninfluenced by an engine speed, the dynamic torque limit being determined using a control loop which adjusts estimated vehicle operation parameters using actual system response information and the value of the dynamic torque limit, the static torque limit being determined based upon a table of predetermined values, and
adjust the operating point of the engine to increase engine torque above the boundary of the un-modified first limit, based upon a balancing of a demand responsiveness criterion and fuel consumption criterion.

15. The system of claim 14 wherein the control system is structured to adjust the operating point of the engine by increasing engine torque above the un-modified first limit and decreasing engine speed.

16. The system of claim 15 wherein the control system is structured to adjust the operating point of the engine based upon a weighted optimization of the demand responsiveness criterion and the fuel consumption criterion.

17. The system of claim 14 wherein the control system is further structured to reinstate the un-modified first limit on engine torque based upon a predetermined criterion of the engine operating point.

18. The system of claim 14 wherein the control system is structured to modify the first limit based at least in part upon a predetermined relationship between the operating point of the engine and the first limit on engine torque.

19. The system of claim 14 wherein the execution of the instructions by the control system is effective to mitigate a vehicle speed lug event.

20. The system of claim 14 wherein the execution of the instructions by the control system is effective to avoid a transmission shift event.

21. A vehicle system comprising:
an engine;
a transmission; and
a control system in operative communication with the engine and the transmission, the control system being structured to:
determine an operating point of the engine, the operating point including an engine torque and an engine speed,
evaluate a relationship between the operating point and a first limit on engine torque,
modify the first limit to permit operation outside a boundary of the un-modified first limit, modification of the first limit being constrained by a second limit on engine torque, and
adjust the operating poi

Assignees

• Cummins Inc

Inventors

• Wall John Carson
• Sujan Vivek Anand

Classifications

• B60W50/12

  Limiting control by the driver depending on vehicle state, e.g. interlocking means for the control input for preventing unsafe operation · CPC title

• B60W50/06

  Improving the dynamic response of the control system, e.g. improving the speed of regulation or avoiding hunting or overshoot · CPC title

• Y02T10/56

  Cross-Sectional Technologies · mapped topic

• B60W10/06

  including control of combustion engines · CPC title

• B60W2710/0644

  Engine speed · CPC title