US 6,748,313 B2 · Method and system for estimating cylinder air charge for an internal combustion engine

Abstract

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.

Claims18

Dependent claims

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.

1 more element

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;
and
provide 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.

2 more elements

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;
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 transition period between the transient condition and a steady-state engine condition.

2 more elements

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 transition period between the transient condition and a steady-state engine condition.

1 more element

Dependencies are inferred from the claim text.

Method and system for estimating cylinder air charge for an internal combustion engine

Life of this patent

Method and system for estimating cylinder air charge for an internal combustion engine

Life of this patent

Abstract

Claims18