Abstract
Physical models of an advanced engine control system were proposed to obtain sophisticated combustion control in ultra-lean combustion engines, including homogeneous compression-ignition and activated radical combustion. The physical models of engine thermodynamics and combustion were incorporated into intake and exhaust models by data fusion which related the in-cylinder pressure with the air mass, for example. The in-cylinder pressure signal was transferred to a Fourier series and the burn rate, which was the fundamental variable of combustion, was determined without integrating the in-cylinder pressure during one engine cycle.