Through processing of digital signals

the energy spectrum of bearing vibration has been obtained

and the gray incidence dynamic matrix being improved

and the energy spectrum of front and rear shafts being analysed by using the said matrix

and the prediction method of maximal peak value of the ball mill’s coal pulverizing capacity being put forward.Practical application shows that the said method has better accuracy for judging the ball mill’s capacity

and can be used for on-line control and operation optimization of ball mills.