Abstract: This disclosure provides an exhaust flow detection and variable dosing system and method for treating exhaust flow from an engine. The system includes first and second exhaust flow legs, a cross passage connecting these legs upstream of SCRs and a sensor positioned along the cross passage to detect at least one of differential pressure between the exhaust flow legs, and exhaust flow in the cross passage. A dosing circuit connects a dosing treatment supply to each of the exhaust flow legs at or upstream of the SCRs, and at least one dosing device positioned along the dosing circuit to control the amount of the dosing agent delivered to each exhaust leg. An electronic control unit controls the amount of a dosing agent delivered to the exhaust flow legs independently based on exhaust flows determined for each leg using at least one of the differential pressure and cross passage exhaust flow.

Abstract: The present method and apparatus employ a signal indicative of cylinder pressure within the combustion chamber of an internal combustion engine to control combustion phasing or start of combustion (SOC) in subsequent cycles of the engine where the engine is driven by combustion of both a fuel/air premixed charge and a directly injected quantity of fuel. A ratio of signals indicative of pre-combustion pressure and post-combustion pressure within a cycle are employed to estimate SOC and then, based on a predetermined target SOC, an ignition lever is employed to adjust subsequent SOC. A preferred ignition lever is, in a pilot fuel ignited engine, pilot fuel quantity.

Abstract: The present method and apparatus employ a signal indicative of cylinder pressure within the combustion chamber of an internal combustion engine to control combustion phasing or start of combustion (SOC) in subsequent cycles of the engine where the engine is driven by combustion of both a fuel/air premixed charge and a directly injected quantity of fuel. A ratio of signals indicative of pre-combustion pressure and post-combustion pressure within a cycle are employed to estimate SOC and then, based on a predetermined target SOC, an ignition lever is employed to adjust subsequent SOC. A preferred ignition lever is, in a pilot fuel ignited engine, pilot fuel quantity.