CONTROL DEVICE AND CONTROL METHOD FOR INTERNAL COMBUSTION ENGINE

摘要

A control device calculates an SOx concentration in exhaust gas on the basis of a sensor output current when a voltage applied to a limiting current sensor is stepped down from a predetermined voltage value. The control device is configured to step up the voltage applied to the limiting current sensor to the predetermined voltage value when the temperature of the limiting current sensor is equal to or lower than a first predetermined temperature or when a condition in which the temperature of the limiting current sensor is predicted to be equal to or lower than the first predetermined temperature is established.

主权项

1. A control device for an internal combustion engine including a limiting current sensor the control device comprising:
an electronic controller configured to: (a) step up a voltage applied to a sensor cell of the limiting current sensor to a predetermined voltage when one of following conditions is satisfied,
(i) a temperature of the limiting current sensor is equal to or lower than a first predetermined temperature, and(ii) a condition in which the temperature of the limiting current sensor is predicted to be equal to or lower than the first predetermined temperature is established, wherein a sulfur component in SOx is attached to a first sensor electrode of the sensor cell of the limiting current sensor when the voltage applied to the limiting current sensor increases, the sulfur component in SOx is detached from the first sensor electrode of the sensor cell of the limiting current sensor when stepping down the voltage applied to the sensor cell of the limiting current sensor; and (b) calculate a parameter related to SOx in a target gas based on a peak value of an output current from the sensor cell of the limiting current sensor which is input to the electronic controller when the voltage applied to the sensor cell of the limiting current sensor is stepped down from the predetermined voltage, and a reference current.