System for limiting engine output power by controlling fueling

• US 8,266,905 B2
• Filed: 05/24/2010
• Issued: 09/18/2012
• Est. Priority Date: 05/01/2007
• Status: Active Grant

• Current Assignee: Cummins Incorporated
• Original Assignee: Cummins Incorporated
• Inventors: Reynolds, David J., Schwab, Zachary, Gutman, Ralph
• Primary Examiner(s): Trieu, Thai Ba
• Application Number:
  US12/786,012
• Publication Number:
  US 20100235071A1
• Time in Patent Office: 848 Days
• Field of Search: 60600-603, 701/103, 701/104, 701/105, 701/114, 701/115, 123/357, 123/305, 123/435, 123/673, 123/674, 123/486
• US Class Current: 60/601
• CPC Class Codes: F02D 2200/0414 Air temperature
• CPC Class Codes: F02D 2250/26 by applying a torque limit
• CPC Class Codes: F02D 41/0007 for control of turbo-charged or super-charged engines control of the pumps per se F02B37/12
• CPC Class Codes: F02D 41/1447 with determination means using an estimation
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

A method for controlling fueling of an internal combustion engine is provided. The engine may include an intake manifold, one or more exhaust manifolds and a turbocharger coupled between the intake and exhaust manifolds. The method may comprise estimating an operating condition of the turbocharger, determining a maximum value of an operating parameter as a function of the estimated operating condition of the turbocharger, measuring a value of the operating parameter, determining an error value as a function of the maximum value of the first operating parameter and the measured value of the operating parameter, and limiting fuel supplied to the engine based on the error value.

Claims

1. A method for controlling fueling of an internal combustion engine, the engine including a fuel system having at least one fuel injector, the method comprising:

determining a fuel quantity to inject into the engine via the at least one fuel injector,

mapping the determined fuel quantity to at least one fuel injector activation time, and

offsetting the at least one fuel injector activation time by a modified time adjustment value that has been generated using at least one value selected from the group consisting of a limited combustion command value, an ignition key value, an intake manifold pressure sensor failure value, an ambient pressure sensor failure value, a timing adjustment value, a programmable proactive adjustment amount value, an initial timing adjustment value, and a proactive adjustment limit value.

2. The method of claim 1, further comprising determining a fuel limit value as a function of one or more of a difference between a maximum turbocharger speed and a measured turbocharger speed, a difference between a maximum boost pressure and a measured boost pressure, and a difference between a maximum engine exhaust temperature and a measured exhaust temperature, and

reducing the at least one fuel injector activation time if the fuel limit value exceeds a threshold fuel value for at least a predetermined time period.

3. The method of claim 1, wherein the at least one fuel injector activation time is a minimum of the modified time adjustment value and a fueling on time value.

4. The method of claim 1, wherein the modified time adjustment value is set to the initial timing adjustment value less the programmable proactive adjustment amount value due to a failure of at least one of the ambient pressure sensor and the intake manifold pressure sensor.

5. The method of claim 1, wherein the modified time adjustment value is generated using at least two values selected from the group consisting of a limited combustion command value, an ignition key value, an intake manifold pressure sensor failure value, an ambient pressure sensor failure value, a timing adjustment value, a programmable proactive adjustment amount value, an initial timing adjustment value, and a proactive adjustment limit value.

6. A method for controlling fueling of an internal combustion engine, the engine including a fuel system having at least one fuel injector, the method comprising:

determining a fuel quantity to inject into the engine via the at least one fuel injector,

mapping the determined fuel quantity to at least on fuel injector activation time,

detecting a failure of at least one of an ambient pressure sensor and an intake manifold pressure sensor, and

offsetting the at least one fuel injector activation time by a modified time adjustment value upon detection of the failure of at least one of the ambient pressure sensor and the intake manifold pressure sensor, wherein the modified time adjustment value is generated using an initial timing adjustment value less a programmable proactive adjustment amount value.

7. The method of claim 6, wherein the modified time adjustment value is generated by using the initial timing adjustment value less the programmable proactive adjustment amount value until a timing adjustment value less a proactive adjustment amount becomes less than the programmable proactive adjustment amount value, at which point the modified time adjustment value is limited to a minimum value of the programmable proactive adjustment amount value.

8. A method for controlling fueling of an internal combustion engine, the engine including a fuel system having at least one fuel injector and a turbocharger having a compressor fluidly coupled to an intake manifold of the engine and a turbine fluidly couple to at least one exhaust manifold of the engine, the method comprising:

determining a fuel quantity to inject into the engine via the at least one fuel injector,

mapping the determined fuel quantity to a time duration during which the at least one injector is activated to inject fuel into the engine,

determining a fuel limit value as a function of one or more of a difference between a maximum turbocharger speed and a measured turbocharger speed, a difference between a maximum boost pressure and a measured boost pressure, and a difference between a maximum engine exhaust temperature and a measured exhaust temperature, and

reducing the time duration during which the at least one injector is activated to inject fuel into the engine if the fuel limit value exceeds a threshold fuel value for at least a predetermined time period.

9. The method of claim 8, wherein reducing the time duration during which the at least one injector is activated to inject fuel into the engine comprises reducing the time duration during which the at least one injector is activated to inject fuel into the engine by a predetermined time value.

10. The method of claim 9, wherein the engine further includes an ignition key that is in an on state when the engine is running and is in an off state when the engine is not running, and wherein reducing the time duration during which the at least one injector is activated to inject fuel into the engine comprises reducing the time duration during which the at least one injector is activated to inject fuel into the engine by the predetermined time value each time the ignition key transitions from its off state to its on state if the fuel limit value exceeds a threshold fuel value for at least a predetermined time period.

11. The method of claim 10 further comprising:

determining a change in the time duration during which the at least one injector is activated to inject fuel into the engine, and activating an error flag if the change in the time duration during which the at least one injector is activated to inject fuel into the engine exceeds a threshold value.

12. The method of claim 10 further comprising:

determining a change in the time duration during which the at least one injector is activated to inject fuel into the engine, and activating visual indicator if the change in the time duration during which the at least one injector is activated to inject fuel into the engine exceeds a threshold value.

13. The method of claim 10 wherein reducing the time duration during which the at least one injector is activated to inject fuel into the engine further comprises limiting reduction of the time duration during which the at least one injector is activated to inject fuel into the engine to a minimum reduction value.

14. The method of claim 10 wherein the engine includes an intake manifold pressure sensor configured to produce the measured boost pressure value and an ambient pressure sensor, and wherein the method further comprises:

determining whether the intake manifold pressure sensor has failed, and determining whether the ambient pressure sensor has failed, and wherein reducing the time duration during which the at least one injector is activated to inject fuel into the engine comprises reducing the time duration during which the at least one injector is activated to inject fuel into the engine if the fuel limit value exceeds the threshold fuel value for at least the predetermined time period only if the intake manifold pressure sensor has not failed and the ambient pressure sensor has not failed.

15. The method of claim 14 further comprising maintaining the time duration during which the at least one injector is activated to inject fuel into the engine if at least one of the intake manifold pressure sensor has not failed and the ambient pressure sensor has not failed.

16. The method of claim 8 further comprising limiting the determined fuel quantity to the fuel limit value prior to mapping the determined fuel quantity to at least one time duration during which an injector is activated to inject fuel into the engine.

17. A method for controlling fueling of an internal combustion engine, the engine including a fuel system having at least one fuel injector and a turbocharger having a compressor fluidly coupled to an intake manifold of the engine and a turbine fluidly coupled to at least one exhaust manifold of the engine, the method comprising:

measuring engine rotational speed,

determining a maximum engine output torque of the engine as a function of the measured engine rotational speed,

determining a fuel limit value as a function of one or more of a difference between a maximum turbocharger speed and a measured turbocharger speed, a difference between a maximum boost pressure and a measured boost pressure and a difference between a maximum engine exhaust temperature and a measured engine exhaust temperature,

determining a fueling growth derate amount as a function of the fuel limit value and the maximum engine output torque if engine fueling is being limited by the fuel limit value, and

activating an error flag if the fueling growth derate amount is greater than a threshold value.

18. The method of claim 17 further comprising activating visual indicator if the fueling growth derate amount is greater than the threshold value.