EXHAUST EMISSION CONTROL DEVICE FOR INTERNAL COMBUSTION ENGINE

摘要

Provided is an exhaust emission control device for an internal combustion engine including in an exhaust system a lean NOx catalyst for trapping NOx in exhaust emissions when the exhaust emissions exist in an oxidizing atmosphere and releasing trapped NOx when the exhaust emissions exist in a reducing atmosphere. In this device, the estimated trapped NOx amount that is the estimate of the amount of NOx trapped by the lean NOx catalyst is calculated by using a neural network. The neural network, to which an engine operating parameter indicating the operating condition of the engine is inputted, outputs a control parameter concerned with the lean NOx catalyst. The reduction treatment of NOx trapped by the lean NOx catalyst is performed according to the estimated trapped NOx amount.