Particulate Matter Detection Strategy In Exhaust Filter

An exhaust filter system for an internal combustion engine comprising:

• an exhaust filter including a housing having an exhaust inlet, an exhaust outlet, and a filter medium positioned within the housing and configured to trap particulates in exhaust gases passed from the exhaust inlet to the exhaust outlet;
• and
• a particulate sensing mechanism coupled with the exhaust filter and including at least one probe configured to transmit electromagnetic energy within the housing, and to receive transmitted electromagnetic energy propagated through particulate matter trapped within the filter medium;
• the particulate sensing mechanism further including an electronic control unit coupled with the at least one probe, and being configured to determine a value indicative of an amount of the trapped particulate matter responsive to a time delay between transmitting and receiving the electromagnetic energy.

A method of operating an exhaust filter system comprising the steps of:

• transmitting electromagnetic energy through an exhaust filter having a filter medium containing trapped particulate matter;
• receiving transmitted electromagnetic energy propagated through the trapped particulate matter;
• and
• commanding regeneration of the exhaust filter responsive to a time delay between the transmission and the reception of the electromagnetic energy.