| 摘要 |
True Top Dead Center (TDC) of an engine piston is determined through determination of the Location of Peak Pressure (LPP) using either of two simplified algorithms (EQ. 4 and 5). A Heat Loss Offset (HLO), drawn from a look-up table based on engine speed, molar mass of the air being compressed, and heat loss rate to the cylinder walls, is added to the calculated LPP (EQ. 1) to provide a corrected and true TDC position for each piston, which corrects for errors in target wheel tooth location of a camshaft position sensor (14) and for any misalignment in the target wheel during installation on an engine (10). Preferably, such a calculation is carried out for each cylinder of a multi-cylinder engine during operation thereof, thus further correcting for machining errors in the crankshaft and for crankshaft bending during the life of the engine. The invention thus allows for more accurate combustion calculations for each individual cylinder. |
