Patent ID: 6496786
Filing Date: 2002-12-17
Classification: G01D,G01P,H02P

Abstract:
A method for obtaining a datum concerning the rotation speed of a rotating object, hereinafter called a rotor, associated with which is a sensor which supplies a sensor signal that has, for each revolution of the rotor, a plurality A of events comprising pulses or edges, said method comprising the following steps:a) at a first instant, the measurement of the rotation speed datum is initiated; b) a second instant, at which an event of the sensor signal following the first instant occurs, is ascertained; c) the number of subsequent events of the sensor signal is sensed; d) at a third predefined instant, termination of the measurement of the rotation speed datum is initiated; e) a fourth instant is ascertained, at which, after the third predefined instant, the number of events since the second instant is equal to a*A, where a=1, 2, 3, . . . , and A=number of events per complete revolution of the motor; and f) the rotation speed datum is calculated from the time interval (&Dgr;t) between second instant and fourth instant and from the number of events sensed up to the fourth instant.