Method for processing a pressure signal and corresponding device

A method for processing a pressure signal originating from a pressure sensor mounted in a combustion chamber, for detecting combustion in an internal combustion engine, the processing of the pressure signal comprising:

• filtering the pressure signal by a filter having a variable gain;
• establishing an output signal representative of the filtered pressure signal;
• establishing a signal representative of an error that can exist between the pressure signal and the output signal;
• establishing a signal representative of a beginning of an expansion phase in the thermodynamic cycle;
• and
• establishing an intermediate signal representative of a great and rapid increase in the pressure in the combustion chamber in the expansion phase based on at least the signal.

A device for acquiring and for processing a pressure signal originating from a pressure sensor mounted in a combustion chamber of an internal combustion engine, for detecting a combustion therein, the device capable of applying the method as claimed in claim 10, and comprising:

• means for acquiring the pressure signal;
• means for processing the pressure signal;
• means for detecting evolution of the pressure signal;
• filtering means having a variable gain to filter the pressure signal;
• means for establishing an output signal representative of the filtered pressure signal;
• means for establishing a signal representative of an error that can exist between the pressure signal and the output signal;
• means for establishing a signal representative of the beginning of the expansion phase in the thermodynamic cycle;
• and
• means for establishing an intermediate signal representative of a great and rapid increase in the pressure in the combustion chamber in the expansion phase based on at least the signal.