Air-fuel ratio determining method for e.g. gasoline engine, involves determining air-fuel ratio of engine based on ratio of total turnover of cylinder to fuel mass supplied to cylinder

摘要

The method involves determining fuel mass supplied to a cylinder in an internal combustion engine (3) and pressure of the cylinder. A total turnover (Qmax) of the cylinder is determined as a maximum of a sum of heating gradients of the cylinder, based on the cylinder pressure. Air-fuel ratio of the engine is determined based on the ratio of the total turnover to the supplied fuel mass. An independent claim is also included for a device for determining an air-fuel ratio of an internal combustion engine.