Predicting rotor's stability using fractional Brownian motion and Hurst index

According properties of fractional Brownian motion, a precision rotor's radial rotating error have been analyzed. The results indicate that rotor's rotating motion is characterized by fractional Brownian motion, i.e. randomicity, nonsequencity, and self-simulation to some extents. Then fractal box counting dimension and Hurst index of radial rotating error have been calculated too. It can be deduced that the rotor's error motion is of stability, it also means in current working condition the precision rotor is going to work stably.