General Electric Company
Method for reducing error in rotor speed measurements

Abstract:

The method of reducing error in rotor speed measurement includes synchronously measuring a rotor having a target including at least one geometric imperfection. Time intervals for the passing of each tooth of a rotor are stored in a circular buffer memory array. Speed is always determined by extracting the time for a complete revolution, so that geometric imperfections and asymmetry of the rotating target do not influence the speed determination, which is always representing the average speed over the latest complete revolution.