Patent ID: 6321735
Filing Date: 2001-11-27
Classification: F02D,F02M

Abstract:
A method of controlling the amount of fuel injected into a cylinder of an internal combustion engine to account for fuel vapors contained in purge gas inducted into the cylinder during purging of an evaporative emission control system that includes a charcoal canister which stores evaporative emissions from a fuel tank, the method comprising the steps of:determining a first data value that is related to the concentration of fuel vapors contained in the purge gas,obtaining a second data value that is related to a desired total quantity of fuel to be delivered to the cylinder,using said first and second data values to determine a third data value that relates to an amount of non-purge fuel to be delivered to the cylinder during purging of the charcoal canister,determining a fourth data value that is related to an amount of fuel to be supplied by a fuel injector, wherein said fourth data value is determined by applying one or more corrections to said third data value, andoperating the fuel injector using a fuel injector control signal that is determined using said fourth data value;wherein the step of determining a first data value further comprises determining said first data value using a fifth data value that is indicative of the concentration of fuel vapors contained in the purge gas, and wherein said fifth data value is determined using closed loop feedback during purging with said closed loop feedback including multiple iterations of the following steps:determining an error representing the magnitude of the difference between a desired air/fuel ratio and a feedback value obtained by measurement of gases exhausted from the cylinder following combustion; andupdating said fifth data value based on the error.