Apparatus and method for detecting crank angle of engine

摘要

A crank angle detecting apparatus of an engine is equipped with a camshaft sensor for outputting the same number of pulse signals CAM as the cylinder number at every stroke phase difference between the cylinders, and further equipped with a crankshaft sensor for outputting a position signal POS 10 at every unit crank angle. A signal of the output position signals POS 10 is omitted at the position where the leading pulse of the pulse signals CAM is generated. On the other hand, a counter CNTFST is equipped for counting up the generation of the position signals POS 10 which will be cleared every time the pulse signal CAM is generated. When the value of the counter CNTFST is equal to or above a threshold value at the time the pulse signal CAM is generated, then the pulse signal CAM is determined as a leading pulse, and the first position signal POS 10 output after the determination is set as the reference position.