Method for evaluating the reliability of a trend analysis, effected by means of the Kriging technique on an operating quantity of machinery, indicative of the presence of defects in the machinery itself

摘要

The method comprises the steps of: acquiring (100) a current value of an operating quantity of the machinery; calculating (101) a first estimated value of the operating quantity by means of the Kriging technique assuming that the local trend of the values of the operating quantity is linear; calculating (140) a first error value on the basis of the current value and the first estimated value of the operating quantity; comparing (160) the first error value with at least one first predetermined threshold value; accepting (170) the first estimated value of the operating quantity whenever the first error value has a first predetermined relationship with the first predetermined threshold value; calculating (200) a second estimated value of the operating quantity by means of the Kriging technique assuming that the local trend of the values of the operating quantity is constant whenever the first error value does not have the said first predetermined relationship with the first predetermined threshold value; calculating (140) a second error value on the basis of the current value and the second estimated value of the operating quantity; comparing (160) the second error value with at least one second predetermined threshold value; and accepting (170) the second estimated value of the operating quantity whenever the second error value has a second predetermined relationship with the second predetermined threshold value. <IMAGE>