A control oriented multivariable identification procedure for turbocharged diesel engines

In this paper, multisine frequency response function identification is used for non-parametric modeling of the air path of a turbocharged diesel engine around a fixed operating point. The Variable Geometry Turbine (VGT) and Exhaust Gas Recirculation (EGR) valve are used as inputs. The nitrogen oxide emissions, air-fuel equivalence ratio, and pressure difference between the intake and exhaust manifold are the considered outputs. A time-efficient and accurate identification procedure for this input-output system is devised, analyzed, and executed experimentally for a range of operating points. The analysis quantifies the individual effects of noise and nonlinearities and shows that the identified linear models capture the actual local behavior with over 97.2% accuracy.