An engine system and method for adjustment in air/fuel ratio control in an engine system

摘要

The invention refers to an engine system (1) and a method in an engine system (1) comprising an internal combustion engine with at least one cylinder (2), and air control means (10) and/or fuel injection means (11), the engine system further comprising an exhaust gas treatment device (8), an upstream gas sensor (13), located upstream of the exhaust gas treatment device (8), and a downstream gas sensor (12), located downstream of, or at least partly within, the exhaust gas treatment device (8). The method comprises
- determining (301, 302, 303), during a finite time period (t1-t2), a plurality of values of a control parameter (U12., U12Diff, C12) related to the downstream gas sensor (12),
- determining (307), after the end of the finite time period (t1-t2), at least one value of an adjustment parameter (A 12) at least partly based on at least some of the control parameter values, and
- adjusting (309) the control of the air control means (10) and/or the fuel injection means (11) at least partly based on at least one of the at least one adjustment parameter value.