Algorithm for determining the top dead center location in an internal combustion engine using cylinder pressure measurements

摘要

A method of determining a top dead center location of a piston in an internal combustion engine including the steps of determining a pressure versus crankshaft angle relation during a compression and an expansion portion of engine operation, defining a pressure ratio relation as the pressure at x number of degrees before a reference crankshaft angle divided by the pressure at x number of degrees after the reference crankshaft angle and shifting the pressure ratio relation a corrective number of degrees to obtain a model shape. Accordingly, the top dead center position is defined relative to the reference crankshaft angle.