Throttle body: modelling and identification

Mathematical modelling of the throttle body air flow is one of the first st eps in generating a generic spark ignition (SI) engine model for control-or iented development. Typically, the throttle body flow model is subdivided i nto components: a one-dimensional isentropic flow law, an empirically deriv ed effective area component and a closed plate leakage term. Of these, only the effective area term presents any difficulty. This paper describes the mathematical formulation and analysis of a generic model for the throttle b ody. Once the model is formulated, the experimental procedure for the ident ification and estimation of the numerical values of the elements within the model is described. The primary focus of the analysis procedure is the sta tistical modelling methods associated with calibrating the effective area t erm. Non-linear repeated measurement analysis methods are used for this pur pose.