Diesel particulate filter monitoring using acoustic sensing

A particulate filter system comprising:

• an exhaust system;
• a filter disposed in said exhaust system;
• an acoustic sensor detecting a frequency relating to said filter, said frequency corresponding to a filter state;
• and
• a controller communicating with said acoustic sensor and obtaining a transfer function from said frequency.

A particulate filter system comprising:

• an exhaust system;
• a filter disposed in said exhaust system;
• a first acoustic sensor arranged on a first side of said filter and a second acoustic sensor arranged on a second side of said filter, at least one of said first and second acoustic sensors detecting a frequency relating to said filter, said frequency corresponding to a filter state;
• and
• a controller communicating with said first and second acoustic sensors, and said controller comparing a first and second output respectively associated with said first and second acoustic sensors to determine said filter state.

A method of determining a filter state of a particulate filter system comprising the steps of:

• a) detecting a frequency with a sensor;
• b) monitoring a powertrain system parameter;
• c) processing the frequency from the sensor relative to the powertrain system parameter to obtain a filter information;
• and
• d) comparing the filter information to a known filter state to determine a present filter state.

A method of determining a filter state of a particulate filter system comprising the steps of:

• a) detecting a frequency with a sensor;
• b) monitoring a powertrain system parameter;
• c) processing the frequency from the sensor relative to the powertrain system parameter to obtain a filter information including determining an acoustical transfer function for the frequency;
• and
• d) comparing the filter information to a known filter state to determine a present filter state.