Patent ID: 6659082
Filing Date: 2003-12-09
Classification: F02B,F02D,Y02T

Abstract:
A method for operating a four-stroke internal combustion engine with a homogeneous lean basic air-fuel mixture, and with compression ignition, said engine having a variable valve operating system for controlling a flow of gases into and out of a combustion space via an inlet valve and an outlet valve, said method comprising:sensing at least one parameter indicative of combustion in a current cycle of said engine; generating real time signals indicative of position and-profile of combustion of said internal combustion engine as a function of sensed parameter values; detecting undesirable operation of said internal combustion engine; in response to the position and profile of combustion, regulating a time of closing of said inlet valve for a next following cycle of said engine to eliminate said undesirable operation, by determining a residual gas fraction to be retained in said combustion space for said next following combustion cycle based on said sensed parameter values; using an adaptive controller to adjust a closing time for said outlet valve to implement said determined residual gas fraction for the next following cycle of the engine; and determining an opening time for the inlet valve in response to required conditions for mixture formation within the combustion space.