Particulate matter controller for an internal combustion engine

摘要

Disclosed is a method for correcting characteristic variation of a PM sensor and improving detection accuracy of the sensor. The PM sensor has a pair of electrodes for capturing the PM in an exhaust gas, and a sensor output changes in accordance with a captured amount of the PM. If the sensor output gets close to a saturated state, the PM combustion control for combusting and removing the PM is executed. If a zero-point output of the PM sensor is to be corrected, first, a sensor output at a point of time when predetermined time required for combustion of the PM has elapsed after electrical conduction to the heater is started by the PM combustion control is obtained. Then, the sensor output at an arbitrary point of time is corrected. As a result, correction of the sensor can be made smoothly by using existing PM combustion control.

主权项

1. A controller for an internal combustion engine comprising:
a PM sensor having a detection portion for capturing particulate matters in an exhaust gas and outputting a detection signal according to the captured amount and a heater for heating the detection portion; a PM combusting unit for combusting and removing the particulate matters by electrical conduction to the heater if a predetermined amount of the particulate matters are captured by the detection portion of the PM sensor; and a zero-point correcting unit for obtaining the detection signal outputted from the detection portion as a zero-point output of the PM sensor and correcting the detection signal at an arbitrary point of time on the basis of the zero-point output under condition that a predetermined time required for completing combustion of particulate matters has elapsed after electrical conduction to the heater by the PM combusting unit is started and the electrical conduction has been kept.