| 摘要 |
PROBLEM TO BE SOLVED: To provide a failure detection device of a filter capable of suppressing variation of diagnostic results of a filter failure by PM particulate diameters, and a particulate substance detection device capable of suppressing variation of output values of a PM sensor by the particulate diameters.SOLUTION: A PM sensor is provided at a downstream of a DPF. A control unit estimates an output value of the PM sensor when the DPF is a filter to be a reference of determination of a failure (S2), and determines whether or not an estimated output value exceeds a predetermined value (S3). When the estimated output value exceeds the predetermined value (S3: YES), after detecting the output value of the PM sensor (S4), the PM sensor is heated by a heater (S5). An output value of the PM sensor risen by heating is detected (S6), and a rate of change of the output values before and after the heating are calculated (S7). An average particle diameter of a PM is estimated based on the rate of change (S8), and sensor output is corrected based on the average particle diameter (S9). Presence and absence of the failure are determined based on comparison between the sensor output after correction and a threshold (S10-S12).SELECTED DRAWING: Figure 6 |
