Logic for improved delta pressure based soot estimation on low restriction particulate filters

A method of estimating accumulated soot within a diesel particulate filter of an exhaust system of a vehicle based on delta pressure, comprising the steps of:

• connecting an exhaust pipe to an engine, the exhaust pipe having therein a diesel oxidation catalyst and a diesel particulate filter;
• connecting a fuel injector device to the exhaust pipe upstream from the diesel oxidation catalyst and the diesel particulate filter;
• configuring a delta exhaust pressure sensor arrangement to measure a difference in exhaust pressure at an inlet to the diesel particulate filter and at an outlet to the diesel particulate filter;
• and
• connecting at least one controller to the fuel injector and to the delta exhaust pressure sensor arrangement, and configuring the at least one controller to:
• 1.) determine when to conduct an active regeneration of the diesel particulate filter based on an estimated amount of soot accumulated therein;
• 2.) in a first regeneration mode, cause the fuel injector device to inject fuel at a first rate into the exhaust stream, and re-evaluate the amount of soot accumulated within the diesel particulate filter under increased volumetric flow of the exhaust stream;
• and
• 3.) in a second regeneration mode, cause the fuel injector device to inject fuel at a second rate into the exhaust stream in order to combust substantially all of the soot trapped in the diesel particulate filter.