Mass fraction burned and pressure estimation through spark plug ion sensing

摘要

Mass fraction burned in a cylinder of an internal combustion engine is determined by measuring an ion signal across a gap of a spark plug and identifying an inflection point of the ion signal. The mass fraction burned is determined using an expression that includes a constant. A value for the constant is determined using the inflection point of the ion signal, and the mass fraction burned is determined using the expression and the constant. <IMAGE>