Abstract: A method for predicting the concentration of one or more undesirable exhaust emissions, such as NOx or HC, from an internal combustion engine. The method determines a mass flow (m(a)) of the charge of air supplied to the engine, the rotational speed (&ohgr;) of the engine, a fuel-equivalence ratio (&phgr;) and an array of look-up tables to predict the concentration of the undesirable exhaust emissions. In some instances, the methodology employs an intermediate term to simply the relationship between the variables to achieve a corresponding simplification of the array of look-up tables. An engine control system that predicts the concentration of one or more undesirable exhaust emissions is also provided.

Abstract: A method for predicting the concentration of one or more undesirable exhaust emissions, such as NOx or HC, from an internal combustion engine. The method determines a mass flow (m(a)) of the charge of air supplied to the engine, the rotational speed (&ohgr;) of the engine, a fuel-equivalence ratio (&phgr;) and an array of look-up tables to predict the concentration of the undesirable exhaust emissions. In some instances, the methodology employs an intermediate term to simply the relationship between the variables to achieve a corresponding simplification of the array of look-up tables. An engine control system that predicts the concentration of one or more undesirable exhaust emissions is also provided.

Abstract: A method and system for controlling exhaust emissions from an engine of a motor vehicle includes sensing oxygen levels upstream and downstream of a catalytic converter, predicting an instantaneous oxygen storage amount in the catalytic converter, determining a maximum oxygen storage capacity, selecting a target percentage of the maximum oxygen storage amount, and controlling the motor vehicle engine performance to a state where the oxygen storage amount is approximately the target percentage of the maximum oxygen storage amount. The instantaneous oxygen storage amount is determined from an oxygen storage mass flow rate, which is determined from a converter-in mass flow rate, converter-out mass flow rate, and a predicted oxygen consumption mass flow rate. The converter-in and converter-out mass flow rates are calculated from an upstream and downstream oxygen mass fraction, respectively, based on the sensed upstream and downstream oxygen levels, respectively.

Abstract: A method and system for controlling exhaust emissions from an engine of a motor vehicle includes sensing oxygen levels upstream and downstream of a catalytic converter, predicting an instantaneous oxygen storage amount in the catalytic converter, determining a maximum oxygen storage capacity, selecting a target percentage of the maximum oxygen storage amount, and controlling the motor vehicle engine performance to a state where the oxygen storage amount is approximately the target percentage of the maximum oxygen storage amount. The instantaneous oxygen storage amount is determined from an oxygen storage mass flow rate, which is determined from a converter-in mass flow rate, converter-out mass flow rate, and a predicted oxygen consumption mass flow rate. The converter-in and converter-out mass flow rates are calculated from an upstream and downstream oxygen mass fraction, respectively, based on the sensed upstream and downstream oxygen levels, respectively.