EXHAUST SYSTEM AND METHOD OF ESTIMATING DIESEL PARTICULATE FILTER SOOT LOADING FOR SAME

摘要

A method of estimating soot loading in a diesel particulate filter (DPF) in a vehicle exhaust system includes determining engine operating conditions of an engine in exhaust flow communication with the diesel particulate filter, and monitoring a pressure differential of the exhaust flow across the diesel particulate filter. The method includes estimating soot loading in the diesel particulate filter according to a pressure-based model using the monitored pressure differential when the engine operating conditions are within a predetermined first set of engine operating conditions, and estimating soot loading in the diesel particulate filter according to an engine-out soot model and a DPF soot loading model when the engine operating conditions are within a predetermined second set of operating conditions. The method includes updating the engine-out soot model based in part on a difference in estimated soot loading between the pressure-based model and the DPF soot loading model.

主权项

1. A method of estimating soot loading in a diesel particulate filter (DPF) in a vehicle exhaust system, the method comprising:
determining engine operating conditions of an engine in exhaust flow communication with the diesel particulate filter; monitoring a pressure differential of the exhaust flow across the diesel particulate filter; estimating soot loading in the diesel particulate filter according to a pressure-based model using the monitored pressure differential when the engine operating conditions are within a predetermined first set of engine operating conditions; wherein said estimating is performed by an electronic controller; estimating soot loading in the diesel particulate filter according to an engine-out soot model and a DPF soot loading model when the engine operating conditions are within a predetermined second set of operating conditions; wherein said estimating is performed by the electronic controller; wherein said engine-out soot model and said DPF soot loading model are stored on the electronic controller; wherein the engine-out soot model is based on the monitored engine operating conditions and the diesel particulate soot loading model is based at least partially on the engine-out soot model; updating the engine-out soot model based in part on a difference in estimated soot loading between the pressure-based model and the DPF soot loading model; wherein said updating the engine-out soot model is performed by the electronic controller in real time when the engine operating conditions are within the first set of engine operating conditions; and wherein said updating the engine-out soot model is performed by the electronic controller after a return to engine operating conditions within the first set of engine operating conditions after operation in the second set of engine operating conditions, and is based in part on a saved estimated soot rate loading value from an engine operating point in the first set of engine operating conditions prior to said operation in the second set of engine operating conditions.