Modeling & reasoning technique of multiple failures based on polychromatic sets

To analyze the multiple failures,a kind of hierarchical multiple failures expression model based on the mechanism of function failure was constructed according to the mapping relationship between failure mode and function element.This expression model was formally described in mathematical language to make it readily manipulated by computers through using the polychromatic sets.Then,using the reasoning matrix between the unit color and individual color of the polychromatic sets,the reasoning of the basic events of the fault was obtained,and the methods and processes of the reasoning were also presented.Finally,a case study of the steam turbine was used to illustrate the proposed model and approach.