Non-equidistant GM(1,1) model based on GCHM_WBO and its application to corrosion rate prediction

GM(1,1) model is widely used in the field of corrosion rate prediction. In this paper, we present a new model, which combines the non-equidistant GM(1,1) model with GCHM_WBO (GCHM, Generalized Contra-Harmonic Mean; WBO, Weakening Buffer Operator), to solve the deadlock that a large number of non-equidistant corrosion rate is difficult to establish a reasonable prediction model and to improve prediction accuracy. It contains a morphing parameter, so as to effectively control the intensity of the weakening operator. The present paper proposes an algorithm to calculate morphing parameter based on a given sample. Finally, the model is applied to predict the corrosion rate of the same series of 6 steels at Guangzhou Experimental Station, and relative error of prediction is within 8.89% to predict the corrosion rate of the 15th year.