Adaptive soot mass estimation in a vehicle exhaust after-treatment device

A system for monitoring a particulate filter of an exhaust after-treatment device in fluid communication with an engine of a vehicle, the system comprising:

• a first fluid tube disposed in fluid communication with the exhaust after-treatment device and between the particulate filter and the engine;
• a second fluid tube disposed in fluid communication with the exhaust after-treatment device and on an opposite side of the particulate filter from the first fluid tube;
• a differential pressure module in communication with the first fluid tube and the second fluid tube and configured to generate a delta-pressure signal corresponding to a pressure drop between the first fluid tube and the second fluid tube;
• and
• a controller in communication with the differential pressure module and configured to:
• receive the delta-pressure signal;
• monitor an engine speed and an engine load from the engine;
• determine a first soot mass estimate from the received delta-pressure signal, the first soot mass estimate having an associated confidence indicator based on the monitored engine speed and engine load;
• determine a second soot mass estimate from the monitored engine speed and engine load;
• output the first soot mass estimate if the confidence indicator is above a predetermined threshold, and output the second soot mass estimate if the confidence indicator is below the predetermined threshold;
• and
• generate a particulate filter regeneration request if the soot mass estimate exceeds a threshold.

A method of providing a soot mass estimate in a vehicle exhaust after-treatment device comprising:

• obtaining a first pressure signal from a first fluid tube disposed in fluid communication with the exhaust after-treatment device and between a particulate filter and an engine;
• obtaining a second pressure signal from a second fluid tube disposed in fluid communication with the exhaust after-treatment device and on an opposite side of the particulate filter from the first fluid tube;
• determining an exhaust gas pressure drop across the particulate filter from the first pressure signal and the second pressure signal;
• determining a first soot mass estimate from the monitored exhaust gas pressure drop;
• monitoring an engine speed and an engine load from an engine in fluid communication with the vehicle exhaust after-treatment device;
• determining a confidence value for the first soot mass estimate using the monitored engine speed and engine load;
• determining a second soot mass estimate from the monitored engine speed and engine load;
• and
• providing the first soot mass estimate if the confidence indicator is above a predetermined threshold, and providing the second soot mass estimate if the confidence indicator is below the predetermined threshold.