초록 ▼

A method is provided for estimating cylinder air charge in an internal combustion engine, such engine having a mass airflow (MAF) sensor and a manifold absolute pressure(MAP) sensor. The method provides such cylinder air charge estimation from signals produced primarily by the manifold absolute pres

A method is provided for estimating cylinder air charge in an internal combustion engine, such engine having a mass airflow (MAF) sensor and a manifold absolute pressure(MAP) sensor. The method provides such cylinder air charge estimation from signals produced primarily by the manifold absolute pressure sensor during engine transient conditions. During a transition period between the transient condition and a steady-state engine condition the method combines signals primarily from both the mass airflow sensor and the manifold absolute pressure sensor to provide such cylinder air charge estimation. During the steady-state condition, the method uses primarily only the mass airflow sensor to provide such cylinder air charge estimation. With such method, the cylinder air charge estimation method utilizes the advantages of both measurement sensors. When transient situation occurs, the engine controller utilizes measurements from MAP sensors (together with measurements from other less significant sensors) to produce the cylinder air charge estimation. When it is determined that the transient situation is converging to a steady state operation, a smoothing algorithm is employed to combine the measurements from both MAF and MAP sensors to produce the cylinder air charge estimation. Finally, when the engine is operating in steady state, only the MAF sensor (together with other less significant sensors) is used to produce the cylinder air charge estimation.

대표청구항 ▼

1. A system for estimating cylinder air charge in an internal combustion engine, such system comprising: a manifold absolute pressure sensor, communicating with an intake manifold of the engine; a mass air flow sensor, communicating with an intake manifold of the engine; and a processor for

1. A system for estimating cylinder air charge in an internal combustion engine, such system comprising: a manifold absolute pressure sensor, communicating with an intake manifold of the engine; a mass air flow sensor, communicating with an intake manifold of the engine; and a processor for providing such cylinder air charge estimation from signals produced primarily by the manifold absolute pressure sensor during engine transient conditions, combining signals primarily from both the mass airflow sensor and the manifold absolute pressure sensor to provide such cylinder air charge estimation during a transition period between the transient condition and a steady-state engine condition, and using primarily only the mass airflow sensor to provide such cylinder air charge estimation during the steady-state condition. 2. A system for estimating cylinder air charge in an internal combustion engine, such system comprising: a processor programmed to: provide such cylinder air charge estimation using a speed density algorithm during engine transition conditions;provide such cylinder air charge estimation using a manifold filling algorithm during a steady-state condition; andprovide such cylinder air charge estimation by combining the estimation from the manifold filling algorithm with the estimation from the speed density algorithm to provide such cylinder air charge estimation during a period between the transient condition and a steady-state engine condition.3. The system recited in claim 2 wherein such processor: uses a smoothing algorithm during the period to interpolate estimations from both the filling algorithm and the speed density algorithm. 4. The system recited in claim 2 wherein the processor: produces the cylinder air charge estimate using the speed density algorithm; detecting a transition period; from such produced cylinder air charge estimate, determines, during the detected transient period, whether such determined cylinder air charge estimate is converging to towards a steady state condition; if such determined estimate is converging, applies a smoothing algorithm to interpolate the cylinder air charge estimation from both the manifold filling and speed density algorithms in combining the estimation from the manifold filling algorithm with the estimation from the speed density algorithm is used to provide such cylinder air charge estimation during the transition period; and when the steady state condition is reached, uses the manifold filling algorithm to provide the air charge estimation. 5. The system recited in claim 4 wherein the processor: if such determined estimate is not converging to the steady state condition, then enables the smoothing algorithm, which interpolates the cylinder air charge estimation from both the manifold filling and speed density algorithms, to provide such cylinder air charge estimation during the transition period. 6. The system recited in claim 5 wherein the interpolation is in accordance with:where: CAC MAFis the cylinder air charge estimation based on manifold filling algorithm calculation; CAC MAPis the cylinder air charge estimation based on speed density algorithm calculation; n fis the total time duration of the smoothing process; and n pis the current duration of the smoothing process.7. A storage media having computer code, such code upon execution:estimating cylinder air charge in an internal combustion engine, such engine having a mass airflow sensor and a manifold absolute pressure sensor communicating with an intake manifold of the engine, comprising: providing such cylinder air charge estimation from signals produced primarily by the manifold absolute pressure sensor during engine transient conditions, combining signals primarily from both the mass airflow sensor and the manifold absolute pressure sensor to provide such cylinder air charge estimation during a transition period between the transient condition and a steady-state engine condition, and using primarily only the mass airflow sensor to provide such cylinder air charge estimation during the steady-state condition. 8. A storage media having computer code, such code upon execution: estimating cylinder air charge in an internal combustion engine, comprising: providing such cylinder air charge estimation using a speed density algorithm during engine transient conditions;providing such cylinder air charge estimation using a manifold filling algorithm during a steady-state condition; andproviding such cylinder air charge estimation by combining the estimation from the manifold filling algorithm with the estimation from the speed density algorithm to provide such cylinder air charge estimation during a transition period between the transient condition and a steady-state engine condition.9. The storage media recited in claim 8 further: using a smoothing algorithm during the transition period to interpolate estimations from both the filling algorithm and the speed density algorithm. 10. The storage media claim 8 further: producing the cylinder air charge estimate using the speed density algorithm; detecting a transition period; from such produced cylinder air charge estimate, determining, during the detected transition period, whether such determined cylinder air charge estimate is converging to towards a steady state condition; if such determined estimate is converging, applying a smoothing algorithm to interpolate the cylinder air charge estimation from both the manifold filling and speed density algorithms in combining the estimation from the manifold filling algorithm with the estimation from the speed density algorithm is used to provide such cylinder air charge estimation during the transition period; and when the steady state condition is reached, using the manifold filling algorithm to provide the air charge estimation. 11. The media recited in claim 10 including: if such determined estimate is not converging to the steady state condition, then the smoothing algorithm, which interpolates the cylinder air charge estimation from both the manifold filling and speed density algorithms, is used to provide such cylinder air charge estimation during a transition period. 12. The method recited in claim 11 wherein the interpolation is in accordance with:where: CAC MAFis the cylinder air charge estimation based on manifold filling algorithm calculation; CAC MAPis the cylinder air charge estimation based on speed density algorithm calculation; n fis the total time duration of the smoothing process; and n pis the current duration of the smoothing process.13. A method for estimating cylinder air charge in an internal combustion engine, such engine having a mass airflow sensor and a manifold absolute pressure sensor communicating with an intake manifold of the engine, such method comprising: providing such cylinder air charge estimation from signals produced primarily by the manifold absolute pressure sensor during engine transient conditions, combining signals primarily from both the mass airflow sensor and the manifold absolute pressure sensor to provide such cylinder air charge estimation during a transition period between the transient condition and a steady-state engine condition, and using primarily only the mass airflow sensor to provide such cylinder air charge estimation during the steady-state condition. 14. A method for estimating cylinder air charge in an internal combustion engine, such method comprising: providing such cylinder air charge estimation using a speed density algorithm during engine transition conditions; providing such cylinder air charge estimation using a manifold filling algorithm during a steady-state condition; and providing such cylinder air charge estimation by combining the estimation from the manifold filling algorithm with the estimation from the speed density algorithm to provide such cylinder air charge estimation during a transiti on period between the transient condition and a steady-state engine condition. 15. The method recited in claim 14 further including: using a smoothing algorithm during the period to interpolate estimations from both the filling algorithm and the speed density algorithm. 16. The method recited in claim 14 further comprising: producing the cylinder air charge estimate using the speed density algorithm; detecting the transition period; from such produced cylinder air charge estimate, determining, during the detected transient period, whether such determined cylinder air charge estimate is converging to towards a steady state condition; if such determined estimate is converging, applying a smoothing algorithm to interpolate the cylinder air charge estimation from both the manifold filling and speed density algorithms in combining the estimation from the manifold filling algorithm with the estimation from the speed density algorithm is used to provide such cylinder air charge estimation during the transition period; and when the steady state condition is reached, using the manifold filling algorithm to provide the air charge estimation. 17. The method recited in claim 16 including: if such determined estimate is not converging to the steady state condition, then the smoothing algorithm, which interpolates the cylinder air charge estimation from both the manifold filling and speed density algorithms, is used to provide such cylinder air charge estimation during the transition period. 18. The method recited in claim 17 wherein the interpolation is in accordance with:where: CAC MAFis the cylinder air charge estimation based on manifold filling algorithm calculation; CAC MAPis the cylinder air charge estimation based on speed density algorithm calculation; n fis the total time duration of the smoothing process; and n pis the current duration of the smoothing process.