MULTI-FUEL ENGINE CONTROL WITH FUEL CONTROL PARAMETER LOCK

摘要

MULTI-FUEL ENGINE CONTROL WITH FUEL CONTROL PARAMETER LOCK A fuel control for an engine using a liquid mixture of two fuels such as gasoline and methanol and derives a fuel control parameter from the output of a fuel composition sensor in a first mode of engine operation and locks the value of the fuel control parameter at the end of the first mode of engine operation for use throughout a second mode of engine operation including closed loop control in response to an air/fuel ratio sensor, as long as the fuel composition does not change more than a predetermined amount during the second mode. The stable operation of the fuel control in the second mode is thus protected from instabilities introduced by small fluctuations in the fuel composition signal. In an engine with adaptive learning control, the adaptive learning control mode is reserved for particularly stable modes of engine operation including closed loop stoichiometric control and thus serves well as the second mode of engine operation.