| 摘要 |
PURPOSE: To provide an engine speed sensing device which can determine the engine speed without impairing the calculating accuracy stably only through system control alteration with which no modification of the mechanical part or circuit part is required. CONSTITUTION: An engine speed sensing device is equipped with a sensor means 2 installed on or in association with the crank shaft 1 of an engine and emitting at certain crank angle intervals each of pulses P having a frequency proportional to the engine speed Re in synchronization with the rotation of the crank shaft and an ECU 3 to calculate the engine speed on the basis of the pulses emitted from the sensor means. The ECU comprises a time difference calculating means 31 to calculate the time differenceΔt(i) of the pulses, a summarizing means 34 to summarize a certain number of time differences corresponding to one stroke among the engine operating strokes, and an engine speed computing means 36 to compute the engine speed on the basis of the obtained value of the summarized time differences Ti, and thereupon the influence of the rotational variation under engine strokes is averaged and suppressed.
|
