Fuel-injection system for engine and process for defining the beginning of pressure drop in common rail

Abstract

A fuel-injection method and an apparatus provides an output timing of an injection command signal so that fuel-injection timing is matched with a basic desired injection timing, to reduce exhaust gases and engine performance, by filtering waveforms of the detected common rail pressure to obtain pressure data, calculating an approximate straight line from the pressure data, spanning from a preselected time to a time T3 of at least the first smallest value after the start of the pressure drop in the common rail pressure, and defining a time, at which the difference between the pressure data and an approximate straight line Ld is the largest value, as the timing T2 of the start of the pressure drop in the common rail pressure, then calculating the time lag Δ Td that spans from the output timing T0 of injection command signal to the fuel-injection timing T1.

Dependencies are inferred from the claim text.