Patent ID: 6766242
Filing Date: 2004-07-20
Classification: F02D,F02P

Abstract:
An engine control apparatus comprising:a rotation signal generating circuit for generating a rotation signal composed of a train of pulses at every interval of a predetermined angle corresponding to a partial turn of the crankshaft of an engine and having a reference position of a different pulse width intermediate the pulse train; a signal processing circuit for measuring a pulse interval by inputting the rotation signal and for detecting the reference position on the basis of the pulse interval, to output a reference position signal corresponding to the reference position; and a microcomputer for inputting the rotation signal and the reference position signal, to detect a crankshaft angle position from the rotation signal and the reference position signal thereby to execute various controls for the engine, wherein the microcomputer is programmed to start an interrupt at each effective edge of the rotation signal, to execute the measurement of the pulse interval by the interrupt and the detection of the reference position on the basis of the pulse interval, to detect, by making the detection result of the reference position by the interrupt effective at the beginning of a start of the engine, the crankshaft angle position on the basis of the detection result, and to detect the crankshaft angle position with the reference position signal by making the reference position detection result effective when the engine is stated, and to detect the crankshaft angle position by making the reference position signal from the signal processing circuit effective in place of the result of the reference position by the interrupt when it is determined that the signal processing circuit is normally operating.