Control method for a variable geometry turbocharger in a diesel engine with exhaust gas recirculation

摘要

A method of estimating the actuator position of a variable geometry turbocharger (VGT) of a compression ignition engine having an exhaust gas recirculation (EGR) system. The method includes the steps of determining the exhaust manifold temperature (T2), determining the mass flow rate (W2t) through the turbocharger turbine, determining the exhaust manifold pressure (p2), determining the turbine back-pressure (pexs), and generating a VGT actuator position estimate ( alpha vgt) as a function of W2t, T2, p2, and pexs. The estimated VGT actuator position is then used to generate an error term indicative of the difference between the estimated and desired VGT actuator position. The error term can then be used to drive the VGT actuator to its desired position to regulate the intake manifold pressure.