Controlling an engine operating parameter during transients in a control data input by selection of the time interval for calculating the derivative of the control data input

摘要

Desired engine fueling data FQL_—MFD_—TQL is processed by a derivative variable time function (40) embodied in an algorithm to develop a data value EGR_—MFD_—DER representing the time derivative of desired fueling. The algorithm comprises certain selectable parameters (EGR_—DTS, EGR_—MFD_—KF, EGR_—MFD_—KD). An iteration of the algorithm includes processing FQL_—MFD_—TQL according to a first function (40A) to yield a first data value and according to a second function (40B) to yield a second data value. A third function (40C) subtracts the second data value from the first to yield a data value for the time derivative that forms one input to a map (42). A second input to the map is a data value for mass airflow (MAF_—GMS). The map provides data for calculating the set point of an EGR valve (36). The invention provides improved control of EGR during fueling transients.