Systems and methods for exhaust gas recirculation valve calibration

A method comprising:

• controlling a pressure in an intake of an engine to a first steady-state intake pressure with an exhaust gas recirculation valve closed;
• commanding the exhaust gas recirculation valve open and determining a second steady-state intake pressure and a differential pressure across a variable orifice associated with the exhaust gas recirculation valve;
• and
• estimating a variable orifice effective area based on the second steady-state intake pressure and the differential pressure,
• wherein the exhaust gas recirculation valve and the variable orifice are different.

A method comprising:

• estimating an exhaust gas recirculation mass flow across a variable orifice based on a steady-state pressure in an intake of an engine attained upon commanding an exhaust gas recirculation valve from a closed position to a predetermined open position;
• inferring a variable orifice effective area based on the exhaust gas recirculation mass flow and a differential pressure recorded across the variable orifice with the exhaust gas recirculation valve in the predetermined open position;
• updating a calibration table to include the variable orifice effective area corresponding to the predetermined open position;
• and
• controlling an amount of recirculated exhaust gas based on the updated calibration table.