Method for operating a four-stroke internal combustion engine
AssigneeDaimlerChrysler AG
InventorsIgor Gruden, Rolf-Guenther Nieberding, Guido Vent
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Abstract
In a method for operating a four-stroke internal combustion engine with a homogeneous, lean basic mixture of air and fuel and with compression ignition, the fuel/air ratio formed in the combustion space is variable by means of a controllable inlet member. In order to achieve as rapid adaptation as possible to varied combustion sequences, a measurement of the respective combustion is carried out and the time of closing of the inlet member of the combustion space is regulated, for a next successive cycle, as a function of the signal obtained from this measurement.
Claims8
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.
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:
- measuring electrical conductivity of a gas mixture in said combustion space during a current cycle of said engine;
- determining a combustion state of said engine in said cycle via an ionization meter;
- determining in real time a residual gas fraction to be retained in said combustion space for a next following cycle of said engine as a function of said combustion state;
- and
- using an adaptive controller to adjust a closing time for said outlet valve to a point which provides said determined residual gas fraction for the next following cycle of the engine.
Dependencies are inferred from the claim text.