ENGINE SYSTEM CONTROL RESPONSIVE TO OXYGEN CONCENTRATION ESTIMATED FROM ENGINE CYLINDER PRESSURE

Method comprising the steps of: determining an oxygen concentration deviation between an oxygen concentration setpoint and an estimated oxygen concentration that is estimated from actual cylinder pressure; determining a boost pressure deviation between a boost pressure setpoint and an actual boost pressure; producing a boost pressure control output in response to the boost pressure deviation; and producing an oxygen concentration control output in response to the oxygen concentration deviation and the boost pressure control output.