METHOD FOR DETERMINING MASS AIRFLOW AND ENGINE CONTROLLER USING MASS AIRFLOW DETERMINED THEREBY

摘要

PURPOSE: To accurately measure a mass airflow, prevent changes in volume efficiency and prevent air leakage in an air intake system by providing a process of correcting a speed density value of the mass airflow as a function of an average normalized air fuel ratio. ;CONSTITUTION: A mass airflow computation apparatus 10 includes an engine calibration reference parameter storage 11 and an engine operating parameter storage 12. According to this apparatus, a speed density value of an airflow rate and an EGR(exhaust gas recirculation) mass airflow rate are computed as functions of an engine speed and an air density, and the speed density value is modified as a function of an average normalized air fuel ratio. Then, at a predetermined threshold of the mass airflow, a different between the speed density calculation performed by an airflow calculator 16 and the measured mass airflow is determined to compute the airflow meter mass airflow offset correction. This is stored and set to be equal to the corrected mass airflow against a throttle position or an engine speed change. Engine control is carried out using the measured mass airflow by this dimension.;COPYRIGHT: (C)1994,JPO