SBS logical bio-diesel sensor

A method for logical sensing of a cetane number of a mixture of crude oil fuel and bio fuel injected by at least one fuel injector into at least one combustion chamber of an internal combustion engine having at least one cylinder configured to burn the injected mixture and for controlling the engine by an electronic engine control unit (ECU) controlling said at least one fuel injector and changing an engine control strategy according to the sensed cetane number to optimize a combustion process, the method including the following logical sensing steps:

• starting a learning process in which a reference value for the cetane number is retrieved from maps pre-registered in said ECU;
• applying the engine control strategy including an injection phase, injection duration and cetane number controls which are specific to the engine;
• extracting all main combustion parameters from a pressure diagram expressing a pressure in said at least one engine cylinder as a function of a crank angle;
• comparing extracted values of said main combustion parameters to corresponding values pre-registered in said ECU;
• identifying from said main combustion parameters a new corresponding cetane number;
• and
• further changing the engine control strategy within the ECU in adapting at least one of the injection phase, duration and cetane number controls to optimize the combustion process.