Patent ID: 9074505
Filing Date: 2015-07-07
Classification: F01N,F02D,Y02T

Abstract:
1. A PM accumulation amount estimation device comprising: a diesel particulate filter (DPF) configured to collect exhaust gas particulate matter (PM) in exhaust gas exhausted to an exhaust path from an internal combustion engine; an airflow meter configured to measure airflow volume; and a control unit including a processor that executes instructions to: estimate a PM accumulation amount of PM accumulating in the DPF; compute a PM emission amount of the PM exhausted to the exhaust path; and compute a PM regeneration amount of the PM passively regenerated in the DPF, wherein the processor further executes instructions to: estimate the PM accumulation amount in the DPF based on a difference between the computed PM emission amount and the computed PM regeneration amount, compute a passive regeneration amount of PM regenerated passively by adding a PM regeneration amount of PM regenerated by oxygen in the exhaust gas and a PM regeneration amount of PM regenerated by nitrogen dioxide in the exhaust gas, the PM regeneration amount by the nitrogen dioxide being computed based on data which is at least in part computed based on an airflow volume measured by an airflow meter provided in an air supply path for supplying air to the internal combustion engine, and wherein when an abnormality is found in the airflow meter, the PM accumulation amount in the DPF is estimated by computing the PM regeneration amount by the nitrogen dioxide without using the airflow volume measured by the airflow meter.