Physics Based Lumped Parameter Modeling of Automotive Canister Fuel Purge

Abstract

A physicsbased model is presented to estimate the flow rate out of the fuel canister purged into the intake manifold. The lumped parameters of the model, including canister capacitance and flow resistance, are employed to obtain a firstorder multiinput and singleoutput dynamic model. The vacuum pressure in the intake manifold and the fuel tank pressure serve as inputs, and the purged fuel flow rate is considered as the model output. The model does not require cumbersome computation, thereby allowing direct implementation in the fueling control to compensate for the extra fuel in regulation of the stoichiometric air–fuel ratio.