System and method of detecting hydraulic start-of-injection

摘要

This disclosure provides system and method that can determine hydraulic start of injection (SOI) in engines using an in-cylinder pressure sensor. The system and method determine apparent heat release rate (AHRR) curve data for the cylinder from the pressure information provided by the in-cylinder pressure sensors, and the hydraulic SOI from the derivative of the AHRR curve data. The system and method provide diagnostic, control and/or compensation opportunities for fuel injector operation in high pressure fuel rail engine systems without use of expensive or complex fuel injector components.

主权项

1. A method of detecting hydraulic start-of-injection (SOI) timing of a fuel injector following a commanded SOI for each fuel injector fluidly connected to a cylinder of an internal combustion engine, comprising:
measuring pressure in a combustion chamber of the cylinder of the internal combustion engine as a function of crankshaft angle; calculating, from the measured pressure, derivative values of the apparent heat release rate (AHRR) of the cylinder as a function of the crankshaft angle; comparing each calculated derivative value with a threshold value indicating heat loss in the cylinder; and determining hydraulic SOI timing of the fuel injector as the crankshaft timing when the derivative value satisfies the threshold value.