A Control-Oriented Model of Cylinder Pressure in Internal Combustion Engines

Control-oriented perturbation models (COPMs) for cylinder pressure in spark-ignited internal combustion engines are becoming important because the anticipation of inexpensive cylinder-pressure transducers has sparked interest in automotive engine control. systems that employ cylinder-pressure feedback. Cylinder-pressure COPMs are novel in that the smallest regions of realistic interest already include nonlinear effects that may not be neglected: the linear perturbation is not adequate. Moreover, the crank angle frame of reference leads to a perturbation on the independent variable as well. These features require higher-order local representations of vector-valued functions of several vector-valued variables, in a form suitable for computation. A comparison of model predictions with actual engine data demonstrates the increased accuracy and consistency made possible with these models.