基于模糊证据推理的内河船舶航行安全状态评价

On the inland river navigation-safety assessment approach based on the fuzzy evidence reasoning approach

在综合考虑我国内河水上交通安全管理部门的需求及相关规定的基础上,构建了船舶在内河航行中的安全评价模型。基于此,将定性指标风险等级划分为高、中、低3等,通过模糊理论构造定量指标的模糊评估等级分布图,根据获取到的指标层评价指标的信息,计算指标层评价指标的模糊信度分布,运用证据推理依次对各层级的评价结果进行融合,最后得到目标层的模糊信度分布。同时,采用效用函数将评价结果进行量化,定义风险等级中的高、中、低对应的效用值为0、0.5、1,从而得到船舶航行安全状态的量化评价结果。基于上述安全评价模型,针对我国内河船舶＂富发888＂开展案例研究,通过该模型计算得到船舶＂富发888＂的安全状态量化分值为0.578 1,属于中等风险水平,其风险等级与其真实航行状态基本吻合。

This paper intends to propose an evaluation model for the navigational safety of inland river navigation system based on the demands of the local maritime safety administration and the relevant regulations. For the said purpose,we have managed to incorporate the fuzzy theory and the evidential reasoning（ ER） algorithm to deal with both the qualitative and quantitative indicators of the model. At the same time,we have managed to evaluate all the indicators at the bottom level（ also known as index level in this paper） and transform them into the distribution of belief items in accordance with the fuzzy theory. And,next,we have managed to apply the ER approach to merge the belief structure information into the index level so that the evaluation indicators can be achieved. Furthermore,it would be possible for us to obtain the assessment results of the goal level in a similar way. Thus,as the evaluation result is presented in the above belief distribution form,it is also necessary to transform the distribution information into crisp values for the comparison purpose by using a utility function needed. Thus,we have worked out in the study the three risk levels,namely,the high level,the medium and low ones,which can be assigned in a utility value of 0,0. 5,and,1,respectively. Furthermore,we have also conducted a case study of cargo ship Fufa No. 888 so as to present and validate the proposed model and the corresponding methods. The evaluation results show that the safety evaluation score of the investigated vessel is 0. 5781,which can be attributed to the moderate risk level.Thus,it can be seen that the risk grade generated from the proposed model tends to be consistent with the real sailing state of the ships. And,furthermore,the said navigational safety assessment model proposed in this paper can also be expected to provide a valuable reference to the maritime safety administration with highly confidential information to assist managers and decision makers in the risk prevention and control,in addition to being used as the early warning means of inland waterway navigation accidents.