Engine control for a common rail fuel system using fuel spill determination

摘要

A system and method for engine control determine a spilled fuel quantity for use in controlling pressure of a common rail fuel system. In one embodiment, a spilled fuel estimate is determined based on rail pressure and engine speed. Another embodiment determines a spilled fuel estimate based on a leakage quantity and a spill control quantity. The leakage quantity represents the amount of fuel leaked past the internal passages inside the injectors and is based on rail pressure alone. The spill control quantity is based on rail pressure and injector energizing time. The spill control quantity represents the fuel used to actuate the injector allowing the injected fuel into the cylinder during the combustion cycle. A more accurate determination of the quantity of fuel pumped based on spilled fuel and injected fuel may be used to improve the common rail pressure control, for example.