METHOD FOR MONITORING PARTICULATE FILTER

摘要

PROBLEM TO BE SOLVED: To present a diagnostic method for a particulate filter arranged in an exhaust line of an internal combustion engine.SOLUTION: The exhaust gas stream downstream of the particulate filter (16) is monitored by means of a downstream soot sensor (20) having a characteristic sensor cycle; and the accumulation of soot at a (virtual) upstream soot sensor is monitored over a respective sensor cycle of the downstream soot sensor (20). The particulate filter (16) operating status is determined on the basis of the information on the downstream and upstream soot sensors. The amount of accumulated soot is determined based on the sensor cycles of the upstream soot sensor, and may be expressed as a soot accumulation level or as the number of sensor cycles. The efficiency of the particulate filter may be determined from the respective number of sensor cycles of the soot sensors. In another embodiment, the upstream soot sensor is simulated by a virtual sensor model.SELECTED DRAWING: Figure 1