ROBUST EGR CONTROL FOR COUNTERACTING EXHAUST BACK-PRESSURE FLUCTUATION ATTRIBUTABLE TO SOOT ACCUMULATION IN A DIESEL PARTICULATE FILTER

摘要

An engine ( 10 ) uses a method for counteracting the effect of soot accumulation in a diesel particulate filter (DPF 38 ) in a diesel engine exhaust system ( 16 ) on the control of exhaust gas recirculation (EGR) through an EGR system ( 40 ). Engine speed (N) and indicated engine torque (TQI) data are processed to select from a map ( 62 ) a data value for present EGR volumetric efficiency. The selected data value and certain other data, including data that accounts for present soot accumulation in the DPF, are processed to develop a data value indicative of present total mass flow. The data value indicative of present total mass flow and still other data are processed to develop flow control data for controlling flow of exhaust gas through the EGR system.