Detecting cylinder-specific combustion profile parameter values for an internal combustion engine

A control device for an internal combustion engine, the internal combustion engine having a reference cylinder with a cylinder pressure sensor and one or more non-reference cylinders, the control device comprising:

• a data memory storing a transfer function;
• and
• a processing unit detecting a cylinder-specific combustion profile parameter value for an internal combustion engine, the processing unit configured to:
• detect a toothed encoder signal;
• determine a cylinder-specific tooth time interval based on the toothed encoder signal;
• detect a pressure value for the reference cylinder;
• determine the combustion profile parameter value for the reference cylinder based on the pressure value;
• determine a cylinder-specific phase value for the non-reference cylinder based on a Fourier transformation of a part of the toothed encoder signal corresponding to the cylinder-specific tooth time interval;
• determine a phase value for the reference cylinder;
• determine the cylinder-specific combustion profile parameter value for the non-reference cylinder based on:
• the cylinder-specific phase value for the non-reference cylinder,
• a stored transfer function which represents a relationship between the cylinder-specific combustion profile parameter and the phase value for the non-reference cylinder, the stored transfer function determined based on previously measured phase values and associated combustion profile parameter values,
• the combustion profile parameter value for the reference cylinder, and
• the phase value for the reference cylinder;
• and
• optimize combustion of the internal combustion engine based on the cylinder-specific combustion profile parameter value for the non-reference cylinder.