Patent ID: 9606040
Date: 2017-03-28
CPC Classifications: F02D,G01N,Y02T

Claim:
1. A sensor controller applied to a particulate matter detection sensor, the particulate matter detection sensor including an attachment portion to which conductive particulate matter contained in gas is attached, and a pair of opposed electrodes spaced from each other at the attachment portion, the particulate matter detection sensor being adapted to output a sensor detection value corresponding to a resistance of the particular matter between the pair of opposed electrodes, the sensor controller being adapted to calculate an amount of attached particulate matter based on the sensor detection value from the particulate matter detection sensor, the sensor controller comprising: a heater configured to heat the attachment portion so as to burn and remove the particulate matter attached to the attachment portion; abnormality diagnosis means for obtaining the sensor detection value outputted from the particulate matter detection sensor during a heating of the heater, and for performing diagnosis of abnormality of the particulate matter detection sensor; and means for storing the sensor detection value as a reference value after the heating of the heater starts, wherein the sensor detection value is stored as the reference value upon the resistance between the pair of electrodes changing to increasing in accordance with the particulate matter being burned and removed during the heating of the heater, wherein the abnormality diagnosis means calculates a rate of change in the sensor detection value during a time period in which the resistance between the opposed electrodes is increasing during the heating of the heater, wherein the abnormality diagnosis means calculates a reference rate based on the stored reference value, and the abnormality diagnosis means performs the diagnosis of abnormality of the particulate matter detection sensor by comparing the calculated rate of the change in the sensor detection value to the calculated reference rate.