Fuzzy Comprehensive Evaluation Of Shore Container Crane Based On Improved Cloud Model

As one of the important port operation machinery,the quayside container crane has played a significant role in the global transshipment.However,in recent years,terminal safety accidents caused by quayside container cranes still occur frequently.How to express the result of safety assessment more accurately and intuitively is the focal point in the process of current safety management research of quayside container cranes.The uncertainty existing in the process of crane safety evaluation mainly manifests as randomness,fuzziness,and discreteness.But due to different basic theories,most of the current researches on crane safety evaluation methods selectively ignore part of them.As an extension of previous researches,a multi-level,uncertainty and quantitative assessment model based on the multi-hierarchy risk index system of quayside container cranes is proposed in this dissertation.And the main contents are as follows:(1)According to the structure and operating characteristics of quayside container cranes,the risk factors which may cause terminal safety accidents are summarized in details based on relevant national standards.These are the basis of the hierarchy assessment system of quayside container cranes.(2)Aiming at the uncertainty such as subjective ambiguity appearing in the crane safety evaluation process,the combined optimization weights of the index are determined by the improved combination weighting model of game theory,and the fuzzy relational matrix of the index is derived by the ridge membership function.Thus,the comprehensive weight and the relationship matrix of the evaluation index of the shore bridge are calculated from the bottom to the top.An evaluation method for quayside container cranes based on fuzzy mathematical theory is proposed to determine the safety evaluation results of each component and the whole quayside container crane,and then the advantages and disadvantages of this method are discussed.(3)In view of the uncertainty factors such as ambiguity,randomness and discreteness in the determination process of importance scale,safety evaluation level,membership function,the concept of cloud model is introduced on the basis of the analysis of the shortcomings of the methods proposed above.The randomness,fuzziness and discreteness existing in the process of crane safety assessment are expressed by the numerical characteristic index described by expectation value(Ex),entropy(En)and hyper entropy(He),causing the results of the crane safety assmssment more objective and more accurate.Therefore,in order to more accurately deal with the uncertainties in the safety assessment process of shore bridges,an improved multi-level fuzzy comprehensive evaluation method is proposed,including the cloud model for reviews,the improved fuzzy relational matrix and the improved combinational optimization weighting method based on cloud model,etc.By comparing with different methods,it can be found that the assessment result of the quayside container crane using this multi-level,uncertainty and quantitative assessment model is more intuitive,more objective and more accurate.This thesis focuses on the uncertainty existing in the process of the crane safety assessment,and proposes an improved evaluation method based on cloud model.This method enriches and improves the existing crane safety evaluation methods and provides technical support for improving the equipment management system of the port.