Method and system incorporating zero-correction for fuel supply control

Abstract

An engine fuel supply system has a main conduit which supplies fuel into an intake passage, a means for regulating fuel flow through this main conduit through a range of values according to the value of a control signal with the fuel flow provided when the control signal is zero being a basic non zero value, a power conduit which selectively supplies fuel into the intake passage, and a means for opening or closing the power conduit. When the power conduit is closed: a basic value Sb for the main conduit control signal is determined according to engine operational parameters; a value Sn is added to Sb; a multiplicative correction is applied; and the main conduit control signal value is determined by subtracting Sn. But, when the power conduit is open: again, a basic value Sb for the main conduit control signal is determined according to engine operational parameters; Sn and a value Sp are added to Sb; a multiplicative correction is applied; and the main conduit control signal value is determined by subtracting Sn and Sp. Here, Sn represents the main conduit control signal value which would be required, in a virtual sense, for providing the basic main conduit flow value from a zero flow value, and the value Sp represents the incremental value of that control signal which would be required to increase the main conduit flow amount by an amount corresponding to the power conduit flow amount when open.