Catalyst temperature estimating device and catalyst temperature estimating method

摘要

A catalyst temperature estimating device that estimates the temperature of an upstream end of a catalyst for purifying exhaust gas of an internal combustion engine in an exhaust gas flow direction by executing a smoothing process for upstream end temperature estimation; the temperature of a downstream end of the catalyst in the exhaust gas flow direction by executing either a downstream end temperature estimation process using the estimated upstream end temperature with a smoothing process for downstream end temperature estimation; and calculates a smoothing coefficient for the estimated downstream end temperature used to smooth the estimated downstream end temperature based on the operation state of the internal combustion engine.

主权项

1. A controller comprising:
an airflow sensor disposed in an intake passage of an internal combustion engine, the airflow sensor measures an amount of air supplied to the internal combustion engine; and an electronic control unit operatively connected to the internal combustion engine connected to the airflow sensor, the electronic control unit configured to: determine an operating state of the internal combustion engine based on the measured amount of air supplied to the internal combustion engine detected by the airflow sensor; estimate a temperature of an upstream end of a catalyst used to purify exhaust gas of the internal combustion engine in an exhaust gas flow direction by executing a smoothing process for upstream end temperature estimation; calculating a smoothing coefficient for downstream end temperature estimation that is used in the smoothing process for downstream end temperature estimation based on the operation state of the internal combustion engine; and estimate a temperature of a downstream end of the catalyst in the exhaust gas flow direction, after estimating the upstream end temperature and calculating the downstream smoothing coefficient, by executing a smoothing process for downstream end temperature estimation using the estimated upstream end temperature, the controller is configured to operate the internal combustion engine in response to the estimated temperature of the upstream end of the catalyst and the estimated temperature of the downstream end of the catalyst.