SYSTEM FOR MEASURING CYCLIC MOVEMENT OF FERROMAGNETIC PART, AND METHOD OF ESTIMATING CYCLIC MOVEMENT OF FERROMAGNETIC PART

摘要

PROBLEM TO BE SOLVED: To provide a system and a method of extracting information related to cyclic movement of a ferromagnetic part from measurement of a magnetic field discharged by the ferromagnetic part in an environment where noise is generated by another varying magnetic source. SOLUTION: This system measures the cyclic movement of the ferromagnetic part in an environment having noise by at least one AC generator 6 including an AC component. The system includes a magnetometer 42 for detecting a signal value corresponding to the cyclic movement of the ferromagnetic part, a sensor for detecting a corresponding value corresponding to the current of the AC generator 6, a filter 8 for calculating an estimated value of the noise included in the signal value and resulting from the AC generator 6 based on the corresponding value, and a subtractor 46 for subtracting the estimated value from the signal value. COPYRIGHT: (C)2011,JPO&INPIT