Model-based combustion analysis for the development of control functions at the EiL-test bench

A methodology of model-based combustion analysis for the development of control functions at the test bed is considered. One focus is hereby the usage of semi-physical models, which are obtained by combination of theoretical physical models with experimental models in order to adjust the overall model to the actual, nonlinear behavior. In the context of engine modeling, the physical model structure offers a priori knowledge and physical interpretability. The experimental part ensures model adaption to real engine behavior, which is realized by using online parameter-estimation methods. Furthermore, the combination of both allows the transferability to other engines. The resulting modeling approach is particularly intended for online applications.Conventional model-based combustion analysis can be extended by semi-physical real time models. These models support the application engineers, especially for the calibration of dynamic engine behavior at the test bench. As an example, an analysis method based on a crank-angle-synchronous semi-physical combustion model is presented, which gives additional insight into the fast and highly time-resolved combustion processes and provides characteristic parameters, which make the effect of different optimization measures comparable.