Research On FMEA Method For Ship Dynamic Positioning System

Failure Mode and Effect Analysis(FMEA)of Marine Engineering Ship Dynamic Positioning system is a systematic analysis method which can be applied into all levels.All failure modes of the ship dynamic positioning system can be found,this paper analyzes their effectsbased onFMEA andprevents danger in advance.This paper takes YH6020 multipurpose tug dynamic positioning system as the research object,the failure mode and effect analysis is carried out,the main finished work are:(1)In this paper,the concept,type and basic principle of FMEA are studied,and the implementation process of FMEA is presented,which makes the FMEA process clear.(2)The FMEA based on the risk ordinal method is applied into YH6020 multipurpose tug dynamic positioning system.The FMEA table is established and the risk order value of each failure mode is calculated.This paper ranks the risk according to the results,and proposes targeted measures for potentially hazardous components.(3)In order to describe the causal relationship between the various faults and clarify the fault model structure,the FMEA based on fault tree is proposed,including fault tree top event,the determination of the boundary conditions,rules of tree creation,the minimum cut set and minimum path set analysis method of fault tree.The fault tree of the multipurpose tug dynamic positioning system is established.Taking the operator station C_Joy as an example,the basic event is sorted by the minimum cut set analysis method.(4)FMEA is applied into the dynamic positioning system based on the analytic hierarchy process and the fuzzy comprehensive evaluation method.Taking the operator station C_Joy operation panel as an example,the fuzzy comprehensive evaluation matrix is established,the relative weight of each factor is obtained based on analytic hierarchy process,and then the first level judgment and second level judgment are obtained.Finally,we clarify the judgment results and get the analytical conclusion.(5)Due to the FMEAbased on the risk ordinal number neglects the relative importance of the risk factor,the FMEA based on the fuzzy evaluation and the gray relational theory is proposed.Firstly,the fuzzy term set of three risk factors and their corresponding fuzzy numbers are established,and then clarify the results,and the failure modes are evaluated.Finally,this paper calculates the gray relational degree of each failure mode based on grayrelational theory to rank the risk of various failure modes.The comparison of the two methods proves that the method is more accurate and effective.