Abstract
High automotive hydrocarbon emission during cold start is a well recognized challenge with increasing importance in moving towards green vehicles. In this study, the applications of the linear model reduction techniques for nonlinear systems are discussed. A reduced order cold start model of an SI engine and after-treatment system is realized using a balanced truncation technique. A nonlinear physical model and the reduced order model are simulated in an open-loop system. The comparison results indicates the balanced truncated model performs good enough since it is reduced without losing its nonlinearities by the similar-transformation which is realized around the operation point used for the linearization.
