Patent ID: 6508237
Filing Date: 2003-01-21
Classification: F02D,Y02T

Abstract:
A method for controlling an internal combustion engine having an exhaust gas recirculation (EGR) circuit including an EGR valve for diverting exhaust gas from an engine exhaust to an engine intake and a variable geometry turbocharger (VGT) circuit, the method comprising:determining an EGR valve position signal; ascertaining a predefined threshold based on at least one engine operating condition; determining an EGR limit signal based on the predefined threshold; applying the EGR limit signal to the EGR valve position signal for determining an EGR command signal for positioning the EGR valve, wherein the EGR limit signal restricts the EGR command signal for preventing the EGR valve from opening if the at least one engine operating condition is below the predefined threshold; and determining a VGT control signal based on a desired air per cycle and further based in part on the EGR command signal so as to allow cooperative EGR and VGT control based on the desired air per cycle while restricting the EGR command signal during specific actual transient conditions that cause the at least one engine operating condition to fall below the predefined threshold.