SELF TUNING CYLINDER PRESSURE BASED HEAT RELEASE COMPUTATION

The paper describes a novel method for self tuning cylinder pressure based heat release computation that is suitable for online usage in e.g. combustion phasing control applications. The method estimates the polytropic exponents and cylinder pressure offsets immediately preceding and succeeding the combustion event respectively using a fast nonlinear least squares method. The polytropic exponent and the pressure offset is subsequently interpolated during the combustion event and a net heat release computation is performed based on the interpolated exponent and pressure. The result is a self tuning heat release algorithm with no need to model heat losses, crevice losses and blow-by.