Method and apparatus to determine a cylinder air charge for an internal combustion engine

• US 8,511,154 B2
• Filed: 05/17/2011
• Issued: 08/20/2013
• Est. Priority Date: 05/17/2011
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Wang, Yue-Yun, Haskara, Ibrahim
• Primary Examiner(s): MCCALL, ERIC SCOTT
• Application Number:
  US13/109,062
• Publication Number:
  US 20120291534A1
• Time in Patent Office: 826 Days
• Field of Search: 731/143.2, 731/143.3, 731/143.4, 731/143.7, 731/147.4
• US Class Current: 73/114.74
• CPC Class Codes: F02B 1/12 with compression ignition with fuel-air charge ignited by compression ignition of an additional fuel F02B7/00
• CPC Class Codes: F02B 29/0406 Layout of the intake air cooling or coolant circuit
• CPC Class Codes: F02D 2200/0402 the parameter being determined by using a model of the engine intake or its components
• CPC Class Codes: F02D 2200/0406 Intake manifold pressure
• CPC Class Codes: F02D 2200/0411 Volumetric efficiency
• CPC Class Codes: F02D 2200/0414 Air temperature
• CPC Class Codes: F02D 2200/101 Engine speed
• CPC Class Codes: F02D 41/0002 Controlling intake air
• CPC Class Codes: F02D 41/0072 Estimating, calculating or determining the EGR rate, amount or flow sensors in EGR systems F02M26/45
• CPC Class Codes: F02D 41/1446 the characteristics being exhaust temperatures
• CPC Class Codes: F02D 41/1448 the characteristics being an exhaust gas pressure
• CPC Class Codes: F02D 41/18 by measuring intake air flow
• CPC Class Codes: F02M 26/47 the characteristics being temperatures, pressures or flow rates
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A method for estimating a cylinder air charge for an internal combustion engine includes determining a first volumetric efficiency corresponding to engine operation with an open exhaust gas recirculation valve, determining a second volumetric efficiency corresponding to engine operation with a closed exhaust gas recirculation valve, determining a cylinder air charge using a selected one of the first and second volumetric efficiencies.

Claims

1. Method for estimating a cylinder air charge for an internal combustion engine, comprising:

determining a first volumetric efficiency corresponding to engine operation with an open exhaust gas recirculation valve;

determining a second volumetric efficiency corresponding to engine operation with a closed exhaust gas recirculation valve; and

determining a cylinder air charge using a selected one of the first and second volumetric efficiencies;

wherein determining the first volumetric efficiency comprises;

determining a proportion of an intake air charge that is recirculated exhaust gas; and

determining the first volumetric efficiency as a function of an engine speed and the proportion of the intake air charge that is recirculated exhaust gas;

wherein determining the proportion of the intake air charge that is recirculated exhaust gas comprises;

determining an effective flow area of the exhaust gas recirculation valve as a function of a position of the exhaust gas recirculation valve and a ratio of an exhaust manifold pressure to an intake manifold pressure;

determining an exhaust gas recirculation flowrate corresponding to the effective flow area of the exhaust gas recirculation valve; and

determining the proportion of the intake air charge as a ratio of the exhaust gas recirculation flowrate to the sum of the exhaust gas recirculation flowrate and an intake air flowrate.

2. The method of claim 1, wherein determining the effective flow area of the exhaust gas recirculation valve comprises referencing a lookup table.

3. The method of claim 1, wherein determining the second volumetric efficiency comprises determining the second volumetric efficiency as a function of an intake air charge density and an engine speed.

4. The method of claim 3, wherein determining the second volumetric efficiency comprises referencing a lookup table.

5. Method for estimating a cylinder air charge for an internal combustion engine, comprising:

determining a proportion of an intake air charge that is recirculated exhaust gas;

determining a first volumetric efficiency as a function of an engine speed and the proportion of the intake air charge that is recirculated exhaust gas;

determining a second volumetric efficiency as a function of an intake air charge density and the engine speed; and

determining a cylinder air charge using a selected one of the first and second volumetric efficiencies;

wherein determining the proportion of the intake air charge that is recirculated exhaust gas comprises;

determining an effective flow area of the exhaust gas recirculation valve as a function of a position of the exhaust gas recirculation valve and a ratio of an exhaust manifold pressure to an intake manifold pressure;

determining an exhaust gas recirculation flowrate corresponding to the effective flow area of the exhaust gas recirculation valve; and

determining the proportion of the intake air charge as a ratio of the exhaust gas recirculation flowrate to the sum of the exhaust gas recirculation flowrate and an intake air flowrate.

6. Method for estimating a cylinder air charge for an internal combustion engine, comprising:

determining an effective flow area of an exhaust gas recirculation valve as a function of a position of the exhaust gas recirculation valve and a ratio of an exhaust manifold pressure to an intake manifold pressure;

determining an exhaust gas recirculation flowrate corresponding to the effective flow area of the exhaust gas recirculation valve;

determining a proportion of the intake air charge as a ratio of the exhaust gas recirculation flowrate to the sum of the exhaust gas recirculation flowrate and an intake air flowrate;

determining a first volumetric efficiency as a function of an engine speed and the proportion of the intake air charge that is recirculated exhaust gas;

determining a second volumetric efficiency as a function of an intake air charge density and the engine speed; and

determining a cylinder air charge using a selected one of the first and second volumetric efficiencies.