Patent ID: 6178749
Filing Date: 2001-01-30
Classification: F02B,F02D,F02M,Y02T

Abstract:
In a compression ignition engine including a variable geometry turbocharger having a compressor and turbine, said turbine responsive to a turbocharger signal for regulating the intake manifold pressure (MAP), and an exhaust gas recirculation (EGR) passage having an EGR valve connecting an intake manifold and exhaust manifold of the engine, said EGR valve responsive to an EGR valve control signal for regulating the flow of exhaust gas and resulting mass airflow into said intake manifold (MAF), a method fo reducing turbo lag comprising the steps of:determining an intake manifold pressure and intake manifold mass airflow setpoint, MAP.sub.d and MAF.sub.d, as a function of the current engine speed and requested fueling rate (W.sub.f,Rsaid setpoints indicative of the desired MAF and MAP for the requested fueling rate;generating modified setpoints, MAF.sub.c and MAP.sub.c, as a function of MAF.sub.d and MAP.sub.d, respectively;determining a MAP value indicative of the current intake manifold pressure;determining a MAF value indicative of the current intake manifold mass airflow:generating said turbocharger signal as a function of MAP.sub.c and said MAP value;generating said EGR valve control signal as a function of MAF.sub.c and said MAF value; andincrementally adjusting the position of said EGR valve and said turbocharger turbine as a function of said turbocharger signal and said EGR valve control signal until said MAF value corresponds to said MAF.sub.d and said MAP value corresponds to said MAP.sub.d.