Patent ID: 6823834
Filing Date: 2004-11-30
Classification: F02D,Y02T

Abstract:
System for estimating an auxiliary-injected fuel quantity injected into an internal combustion engine separate from a main-injected fuel quantity, comprising:a fuel injector responsive to an injector on-time signal, having separate main-injection and auxiliary-injection on-times, to inject fuel into the engine; a fuel collection unit supplying fuel to the fuel injector; a fuel pump supplying pressurized fuel to the fuel collection unit; a pressure sensor in fluid communication with the fuel collection unit and producing a pressure signal indicative of fuel pressure therein; and a control circuit periodically generating an auxiliary-injected fuel quantity model by disabling the fuel pump prior to fuel injection, and enabling the fuel pump to resume fuel pumping following fuel injection, by the fuel injector, determining based on the pressure signal a first pressure in the fuel collection unit after stabilization of the fuel pressure therein following disablement of the fuel pump and prior to the fuel injection, determining based on the pressure signal a second pressure in the fuel collection unit after the fuel injection and prior to resuming pumping of fuel by the fuel pump, and forming the auxiliary-injected fuel quantity model as a function of the first and second pressures and the injector on-time signal for a number of different engine operating conditions, the control circuit estimating the auxiliary-injected fuel quantity according to the auxiliary-injected fuel quantity model.