Patent ID: 7543486

Claim:
A method for determination as a function of time an angle of rotation of a crankshaft of a j-stroke engine comprising k cylinders and a target wheel, the wheel including a disc comprising l teeth numbered from 1 to l, evenly distributed on a periphery of the disc, wherein at least one missing tooth d, which has been removed, allows determination of a complete revolution of the crankshaft, and wherein a periodic signal comprising pulses is acquired as a function of time by a sensor associated with the target wheel, each pulse indicating the passage of a tooth past the sensor, comprising: a) estimating the position of a missing pulse on the signal corresponding to the at least one missing tooth d during a cycle N of the engine, by estimating, during cycle N, a time interval S between passage past the sensor of a tooth d p preceding the missing tooth d and the passage past the sensor of a tooth d s following the missing tooth d, by means of a time interval between passage of identical teeth during a previous cycle N−1 and estimating a position of the missing pulse in the time interval S, according to the position of the pulses in time interval A between passage past the sensor of tooth d p −r and the passage past the sensor of tooth d s −r during cycle N, with r = lj 2 ⁢ ⁢ k ; and b) determining as a function of time a crankshaft rotation angle by means of the estimated position.