Granted Patent B1

US 7,676,322 · App. 12/367,935 · Granted Mar 9, 2010

Abstract

Claims (58)

1. A combustion control system for a vehicle, comprising:

a pressure ratio (PR) module that determines fired PR values and measured motored PR values based on cylinder pressures measured by a cylinder pressure sensor when a cylinder of an engine is fired and motored, respectively;

a pressure ratio difference (PRD) module that determines PRD values for predetermined crankshaft angles, wherein each of said PRD values is determined based on one of said fired PR values and one of said measured motored PR values at one of said predetermined crankshaft angles; and

a pressure ratio difference rate (PRDR) module that determines and outputs a PRDR value based on a rate of change of said PRD values over a range of said predetermined crankshaft angles.

2. The combustion control system of claim 1 wherein said PRD module determines a first PRD value and a second PRD value for a first one and a second one of said predetermined crankshaft angles, respectively,

wherein said PRDR module determines said PRDR value based on a difference between said first and second PRD values, and

wherein said range is defined by said first and second ones of said predetermined crankshaft angles.

3. The combustion control system of claim 1 further comprising a heat release profile module that determines a heat release profile for fuel provided to said cylinder based on said PRDR value.

4. The combustion control system of claim 3 further comprising a timing control module that adjusts a combustion timing for said cylinder based on said heat release profile.

5. The combustion control system of claim 4 wherein said combustion timing comprises a fuel injection timing.

6. The combustion control system of claim 1 wherein said PRDR module determines said PRDR value further based on a combustion timing and an EGR valve opening.

7. The combustion control system of claim 1 further comprising at least one of:

a pressure ratio difference average (PRDA) module that determines a PRDA value based on an average of a number of said PRD values; and

an indicated mean effective pressure difference (IMEPD) module that determines an IMEPD value based on a fired indicated mean effective pressure (IMEP) value and a motored IMEP value for said cylinder.

8. The combustion control system of claim 7 further comprising a diagnostic module that diagnoses at least one of a quantity of fuel provided to said cylinder, a cetane number (CN) for said fuel, and a crankshaft angle at which a predetermined amount of said fuel was combusted within said cylinder based on at least one of said PRDA value and said IMEPD value.

9. A combustion control system for a vehicle, comprising:

an indicated mean effective pressure (IMEP) module that determines fired IMEP values and motored IMEP values based on cylinder pressures measured by a cylinder pressure sensor when a cylinder of an engine is fired and motored, respectively; and

an indicated mean effective pressure difference (IMEPD) module that determines and outputs an IMEPD value based on a difference between one of said fired IMEP values and one of said motored IMEP values.

10. The combustion control system of claim 9 further comprising a diagnostic module that diagnoses at least one of a quantity of fuel provided to said cylinder, a cetane number (CN) for said fuel, and a crankshaft angle at which a predetermined amount of said fuel was combusted within said cylinder based on said IMEPD value.

11. The combustion control system of claim 10 further comprising:

a pressure ratio (PR) module that determines fired PR values and measured motored PR values based on said cylinder pressures;

a pressure ratio difference (PRD) module that determines PRD values for predetermined crankshaft angles, wherein each of said PRD values is determined based on one of said fired PR values and one of said measured motored PR values at one of said predetermined crankshaft angles; and

a pressure ratio difference rate (PRDR) module that determines and outputs a PRDR value based on a rate of change of said PRD values over a range of said predetermined crankshaft angles.

12. The combustion control system of claim 11 wherein said PRD module determines a first PRD value and a second PRD value for a first one and second one of said predetermined crankshaft angles, respectively,

wherein said PRDR module determines said PRDR value based on a difference between said first and second PRDs, and

wherein said range is defined by said first and second ones of said predetermined crankshaft angles.

13. The combustion control system of claim 11 further comprising a heat release profile module that determines a heat release profile for fuel provided to said cylinder based on said PRDR value.

14. The combustion control system of claim 13 further comprising a timing control module that adjusts a combustion timing for said cylinder based on said heat release profile.

15. A method for a vehicle, comprising:

determining fired pressure ratio (PR) values and measured motored PR values based on cylinder pressures measured by a cylinder pressure sensor when a cylinder of an engine is fired and motored, respectively;

determining pressure ratio difference (PRD) values for predetermined crankshaft angles, wherein each of said PRD values is determined based on one of said fired PR values and one of said measured motored PR values at one of said predetermined crankshaft angles;

determining a pressure ratio difference rate (PRDR) value based on a rate of change of said PRD values over a range of said predetermined crankshaft angles; and

outputting said PRDR value.

16. The method of claim 15 wherein said determining said PRD values comprises determining a first PRD value and a second PRD value for a first one and a second one of said predetermined crankshaft angles, respectively,

wherein said determining said PRDR value comprises determining said PRDR value based on a difference between said first and second PRD values, and

wherein said range is defined by said first and second ones of said predetermined crankshaft angles.

17. The method of claim 15 further comprising determining a heat release profile for fuel provided to said cylinder based on said PRDR value.

18. The method of claim 17 further comprising adjusting a combustion timing for said cylinder based on said heat release profile.

19. The method of claim 18 wherein said adjusting said combustion timing comprises adjusting a fuel injection timing.

20. The method of claim 15 wherein said determining said PRDR value comprises determining said PRDR value further based on a combustion timing and an EGR valve opening.

21. The method of claim 15 further comprising at least one of:

determining a pressure ratio difference average (PRDA) value based on an average of a number of said PRD values; and

determining an indicated mean effective pressure difference (IMEPD) value based on a fired indicated mean effective pressure (IMEP) value and a motored IMEP value for said cylinder.

22. The method of claim 21 further comprising diagnosing at least one of a quantity of fuel provided to said cylinder, a cetane number (CN) for said fuel, and a crankshaft angle at which a predetermined amount of said fuel was combusted within said cylinder based on at least one of said PRDA value and said IMEPD value.

23. A method for a vehicle, comprising:

determining fired indicated mean effective pressure (IMEP) values and motored IMEP values based on cylinder pressures measured by a cylinder pressure sensor when a cylinder of an engine is fired and motored, respectively; and

determining an indicated mean effective pressure difference (IMEPD) value based on a difference between one of said fired IMEP values and one of said motored IMEP values.

24. The method of claim 23 further comprising diagnosing at least one of a quantity of fuel provided to said cylinder, a cetane number (CN) for said fuel, and a crankshaft angle at which a predetermined amount of said fuel was combusted within said cylinder based on said IMEPD value.

25. The method of claim 24 further comprising:

determining fired pressure ratio (PR) values and measured motored PR values based on said cylinder pressures;

determining pressure ratio difference (PRD) values for predetermined crankshaft angles, wherein each of said PRD values is determined based on one of said fired PR values and one of said measured motored PR values at one of said predetermined crankshaft angles;

determining a pressure ratio difference rate (PRDR) value based on a rate of change of said PRD values over a range of said predetermined crankshaft angles; and

outputting said PRDR value.

26. The method of claim 25 wherein said determining said PRD values comprises determining a first PRD value and a second PRD value for a first one and a second one of said predetermined crankshaft angles, respectively,

wherein said determining said PRDR value comprises determining said PRDR value based on a difference between said first and second PRD values, and

wherein said range is defined by said first and second ones of said predetermined crankshaft angles.

27. The method of claim 25 further comprising determining a heat release profile for fuel provided to said cylinder based on said PRDR value.

28. The method of claim 27 further comprising adjusting a combustion timing for said cylinder based on said heat release profile.

Assignments (8)