초록 ▼

A method for operating an internal combustion engine includes determining an actual combustion heat release during ongoing engine operation, calculating an expected combustion heat release corresponding to engine operation associated with the actual combustion heat release during ongoing engine oper

A method for operating an internal combustion engine includes determining an actual combustion heat release during ongoing engine operation, calculating an expected combustion heat release corresponding to engine operation associated with the actual combustion heat release during ongoing engine operation, determining a difference between the actual combustion heat release and the expected combustion heat release, and operating the internal combustion engine in a homogeneous-charge compression-ignition combustion mode to achieve a preferred combustion phasing during each combustion cycle in response to the difference between the actual combustion heat release and the expected combustion heat release.

대표청구항 ▼

1. A method for operating an internal combustion engine, the method comprising: determining an actual combustion heat release during ongoing engine operation;calculating an expected combustion heat release corresponding to engine operation associated with the actual combustion heat release during on

1. A method for operating an internal combustion engine, the method comprising: determining an actual combustion heat release during ongoing engine operation;calculating an expected combustion heat release corresponding to engine operation associated with the actual combustion heat release during ongoing engine operation;determining a difference between the actual combustion heat release and the expected combustion heat release, comprising: determining a combustion heat release deviation corresponding to the difference between the actual combustion heat release and the expected combustion heat release, anddetermining a deviation in an engine coolant temperature associated with the combustion heat release deviation; andoperating the internal combustion engine in a homogeneous-charge compression-ignition combustion mode to achieve a preferred combustion phasing during each combustion cycle in response to engine coolant temperature and the deviation in the engine coolant temperature associated with the combustion heat release deviation. 2. The method of claim 1, wherein determining the actual combustion heat release comprises determining a combustion heat release for each cylinder correlated to in-cylinder combustion pressure measured during each combustion cycle. 3. The method of claim 2, wherein determining the combustion heat release for each cylinder comprises determining an average energy release rate corresponding to in-cylinder combustion pressure during each combustion cycle. 4. The method of claim 1, wherein calculating the expected combustion heat release comprises calculating an average energy release rate corresponding to a fuel/air equivalence ratio, a volumetric efficiency and a gas temperature at intake valve closing for an engine operating point corresponding to the ongoing engine operation. 5. The method of claim 4, wherein calculating an average energy release rate comprises executing a combustion process model to calculate the average energy release rate for the engine operating point corresponding to the ongoing engine operation. 6. The method of claim 1, further comprising: determining a magnitude of combustion chamber deposits corresponding to the difference between the actual combustion heat release and the expected combustion heat release; andwherein operating the internal combustion engine in the homogeneous-charge compression-ignition combustion mode to achieve the preferred combustion phasing during each combustion cycle in response to the engine coolant temperature and the deviation in the engine coolant temperature associated with the combustion heat release deviation comprises operating the internal combustion engine in the homogeneous-charge compression-ignition combustion mode to achieve the preferred combustion phasing during each combustion cycle in response to the magnitude of combustion chamber deposits corresponding to the difference between the actual combustion heat release and the expected combustion heat release. 7. A method for operating an internal combustion engine, the method comprising: determining a first parameter corresponding to an actual combustion heat release at an engine operating point;determining a second parameter corresponding to an expected combustion heat release, the expected combustion heat release correlated to engine operating parameters at the engine operating point;determining a magnitude of combustion chamber deposits corresponding to a difference between the first and second parameters, comprising: determining a deviation in an engine coolant temperature associated with a combustion heat release deviation corresponding to the difference between the first parameter and the second parameter, and determining the magnitude of combustion chamber deposits corresponding to the deviation in engine coolant temperature; andoperating the internal combustion engine in the homogeneous-charge compression-ignition combustion mode to achieve a preferred combustion phasing at the engine operating point in response to the magnitude of combustion chamber deposits. 8. The method of claim 7, wherein determining the first parameter comprises determining a combustion heat release for each cylinder correlated to in-cylinder combustion pressure measured at the engine operating point. 9. The method of claim 8, wherein determining the combustion heat release for each cylinder comprises determining an average energy release rate corresponding to in-cylinder combustion pressure during each combustion cycle. 10. The method of claim 7, wherein determining the second parameter comprises calculating an average energy release rate corresponding to a fuel/air equivalence ratio, a volumetric efficiency and gas temperature at intake valve closing for the engine operating point. 11. The method of claim 10, wherein calculating the average energy release rate comprises executing a combustion process model to calculate the average energy release rate for the engine operating point. 12. A method for operating an internal combustion engine, the method comprising: determining an actual combustion heat release for engine operation at an engine operating point;determining an expected combustion heat release, the expected combustion heat release correlated to engine operating parameters at the engine operating point;determining an adjustment to an integrated thermal state parameter, said adjustment corresponding to a difference between the actual and the expected combustion heat releases; andoperating the internal combustion engine in a homogeneous-charge compression-ignition combustion mode using the adjustment to the integrated thermal state parameter corresponding to the difference between the actual and the expected combustion heat releases. 13. The method of claim 1, wherein operating the internal combustion engine in the homogeneous-charge compression-ignition combustion mode to achieve the preferred combustion phasing during each combustion cycle in response to engine coolant temperature and the deviation in the engine coolant temperature associated with the combustion heat release deviation comprises: determining an integrated thermal state parameter in accordance with the following relationship: TEFF=TC+TLOAD+TINT+THUM+TALT+TFUEL+TDEP wherein TEFF is the integrated thermal state parameter,TC is the engine coolant temperature,TLOAD is a temperature bias term corresponding to engine load and engine load history,TINT is a temperature bias term corresponding to intake air temperature,THUM is a temperature bias term corresponding to ambient humidity,TALT is a temperature bias term corresponding to altitude,TFUEL is a temperature bias term corresponding to fuel quality, andTDEP is the deviation in the engine coolant temperature associated with the combustion heat release deviation; andoperating the internal combustion engine in the homogeneous-charge compression-ignition combustion mode to achieve the preferred combustion phasing during each combustion cycle in response to the integrated thermal state parameter. 14. The method of claim 12, wherein operating the internal combustion engine in a homogeneous-charge compression-ignition combustion mode using the adjustment to the integrated thermal state parameter comprises: determining an integrated thermal state parameter in accordance with the following relationship: TEFF=TC+TLOAD+TINT+THUM+TALT+TFUEL+TDEP wherein TEFF is the integrated thermal state parameter,TC is the engine coolant temperature,TLOAD is a temperature bias term corresponding to engine load and engine load history,TINT is a temperature bias term corresponding to intake air temperature,THUM is a temperature bias term corresponding to ambient humidity,TALT is a temperature bias term corresponding to altitude,TFUEL is a temperature bias term corresponding to fuel quality, andTDEP is the deviation in the engine coolant temperature associated with the combustion heat release deviation; andoperating the internal combustion engine in a homogeneous-charge compression-ignition combustion mode using the adjustment to the integrated thermal state parameter corresponding to the difference between the actual and the expected combustion heat releases.