Combustion process estimation in cylinders based on an integrated engine model of the wiebe function and a piston-crank mechanism

This paper presentes an approach for estimating the output torque of an engine and the pressure and intake fuel gas amount in a cylinder from the rotational angle of a crankshaft. The approach requires an engine model of mechanical motion with its combustion process. The mechanical motion and the combustion process are thus described respectively by a piston-crank model and the wiebe function, and they are integrated into the engine model. Engine data are estimated offline by an observer based on the Unscented Kalman Filter with the proposed engine model. The effectiveness of the proposed approach is demonstrated through the comparison of estimated engine data with measured data.