System and method for air flow and EGR flow estimation
First Claim
1. A system for estimating engine flows, including exhaust gas flow from an exhaust manifold of an internal combustion engine to an intake manifold of the engine and airflow into an engine cylinder, the system comprising:
- a flow control valve having a variable orifice positioned in an exhaust gas recirculation path between the exhaust manifold and intake manifold of the engine;
a fixed orifice area located in said path and downstream of said valve; and
a computer for determining a first signal related to pressure between said fixed orifice area and said flow control valve, determining a second signal related to pressure downstream of said fixed orifice area, calculating a third signal related to the exhaust gas flow based on said first signal and said second signal, and determining a fourth signal related to the airflow based on said second signal and said third signal.
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Accused Products
Abstract
An exhaust gas recirculation systems directs exhaust gasses from an exhaust manifold to an intake manifold of an internal combustion engine. The exhaust gasses travel from the exhaust manifold, first passing through a flow control valve and then through a measuring orifice before entering the intake manifold. Pressure upstream of the orifice is used, along with correction pressure downstream of the orifice, to measure and control exhaust gas flow. Further, manifold pressure is determined from downstream pressure and the used along with the measured exhaust gas flow to calculated a cylinder air charge amount.
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Citations
37 Claims
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1. A system for estimating engine flows, including exhaust gas flow from an exhaust manifold of an internal combustion engine to an intake manifold of the engine and airflow into an engine cylinder, the system comprising:
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a flow control valve having a variable orifice positioned in an exhaust gas recirculation path between the exhaust manifold and intake manifold of the engine;
a fixed orifice area located in said path and downstream of said valve; and
a computer for determining a first signal related to pressure between said fixed orifice area and said flow control valve, determining a second signal related to pressure downstream of said fixed orifice area, calculating a third signal related to the exhaust gas flow based on said first signal and said second signal, and determining a fourth signal related to the airflow based on said second signal and said third signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A system for estimating engine flows, including exhaust gas flow from an exhaust manifold of an internal combustion engine to an intake manifold of the engine and airflow into an engine cylinder, the system comprising:
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a flow control valve having a variable area orifice positioned in an exhaust gas recirculation path between the exhaust manifold and intake manifold of the engine;
a fixed orifice area located in said path and downstream of said valve;
a first pressure sensor coupled to said path between said variable area orifice and said fixed orifice area;
a second pressure sensor coupled to said path downstream of said fixed orifice area; and
a computer for reading said first pressure sensor and said second pressure sensor, calculating the exhaust gas flow based on said first pressure and said second pressure, and determining the cylinder airflow based on said second pressure and said calculated exhaust gas flow. - View Dependent Claims (10, 11, 12, 13, 14, 15)
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16. A method for estimating engine flows, including exhaust gas flow from an engine exhaust to and engine intake wherein the flow passes through a flow control valve and then a fixed area measuring orifice and airflow into an engine cylinder, the method comprising;
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determining a pressure difference across the measuring orifice;
determining a pressure downstream of the measuring orifice representative of manifold pressure;
calculating the exhaust gas flow based on said downstream pressure and said differential pressure;
determining a cylinder exhaust gas amount by filtering the calculated exhaust gas flow; and
determining a parameter related to the cylinder airflow based on said cylinder exhaust gas amount and said downstream pressure. - View Dependent Claims (17, 18)
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19. A system for estimating engine flows, including exhaust gas flow from an exhaust manifold of an internal combustion engine to an intake manifold of the engine and airflow into an engine cylinder, the system comprising:
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a flow control valve having a variable orifice positioned in an exhaust gas recirculation path between the exhaust manifold and intake manifold of the engine;
a fixed orifice area located in said path and downstream of said valve; and
a computer for determining a first signal related to pressure downstream of said fixed orifice area, determining a second signal related to differential pressure across said fixed orifice area, calculating a third signal related to the exhaust gas flow based on said first signal and said second signal, and determining a fourth signal related to the cylinder airflow based on said first signal and said third signal. - View Dependent Claims (20, 21, 22, 23, 24)
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25. A system for estimating engine flows, including exhaust gas flow from an exhaust manifold of an internal combustion engine to an intake manifold of the engine, the system comprising:
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a flow control valve having a variable orifice positioned in an exhaust gas recirculation path between the exhaust manifold and intake manifold of the engine;
a fixed orifice area located in said path and downstream of said valve; and
a computer for determining a first signal related to pressure between said fixed orifice area and said flow control valve, determining a second signal related to pressure downstream of said fixed orifice area, and determining the exhaust gas flow based on said first signal and said second signal. - View Dependent Claims (26, 27, 28, 29, 30)
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31. A system for estimating engine flows, including exhaust gas flow from an exhaust manifold of an internal combustion engine to an intake manifold of the engine and airflow into an engine cylinder, the system comprising:
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a flow control valve having a variable orifice positioned in an exhaust gas recirculation path between the exhaust manifold and intake manifold of the engine;
a fixed orifice area located in said path and downstream of said valve; and
a computer for determining a first signal related to pressure between said fixed orifice area and said-flow control valve, determining a second signal relate to pressure downstream of said fixed orifice area, determining a third signal related to the exhaust gas flow based on said first signal, and determining a fourth signal related to the cylinder airflow based on said second signal and said third signal. - View Dependent Claims (32, 33, 34, 35, 36, 37)
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Specification