Manner and the device null rotary body which seek the rpm gradient

摘要

PROBLEM TO BE SOLVED: To reduce a size of errors generated when a rotational frequency gradient of a rotary object is obtained with the use of a time point when the rolling object reaches a specific position or with the use of an interval of the time points, and the dependence of the error on the rotational frequency. ;SOLUTION: A rotational frequency difference which is a basis for calculating the rotational frequency gradient is formed by subtracting a term in which the rotational frequency as a basis for calculating the rotational frequency difference is calculated. Alternatively, the calculation of the rotational frequency gradient is carried out at preliminarily set time intervals.;COPYRIGHT: (C)2001,JPO