Patent ID: 6498979
Filing Date: 2002-12-24
Classification: G01M

Abstract:
An engine control unit comprising:a crank signal generating means for generating a crank signal comprising a pulse train and a series of reference positions, wherein the reference positions occur every 360Â° CA, and wherein each reference position corresponds to a rotation of a crankshaft of a four-cycle engine; a cylinder determination signal generating means for generating a cylinder determination signal, wherein a level of the cylinder determination signal in a front reference position of every 720Â° CA is different than the level of the cylinder determination signal in a back reference position of every 720Â° CA, and wherein the level of the cylinder determination signal at an angle before each reference position is different from the level of the cylinder determination signal in each of the reference positions; a pulse interval measuring means for measuring a pulse interval of the pulse train; a frequency multiplication signal generating means for generating frequency multiplication signals an integer number of times during the pulse interval and for outputting a clock signal for engine control; and a determining means for determining the front reference position and the back reference position based on both the level of the cylinder determination signal in the reference positions and an amount of angle that the cylinder determination signal has a different level preceding the reference positions.