基于模糊证据理论的铁路信号系统风险评价

为综合考虑风险中的不确定性对评价结果的影响,针对目前铁路信号系统风险评价中无法充分利用专家定性评价信息的问题,提出一种基于模糊证据理论的铁路信号系统风险评价方法。首先在对系统进行风险识别的基础上,采用模糊集理论对风险因素进行统一的模糊描述;然后将模糊集中的描述映射在证据理论的识别框架下,通过证据理论进行信息融合;再结合风险因素权重进行综合评价,确定铁路信号系统的风险等级。以无线闭塞中心临时限速处理功能为例进行风险评价,分析确定该功能的风险等级,评估结果与实际情况相符,验证了该方法的有效性、合理性和可行性。

On the risk assessment for the railway signal system based on the fuzzy evidence theory

This paper is aimed at introducing a comprehensive risk assessment model for the railway signal system.As is known,there may exist lots of different uncertain factors that may affect the risk assessment success for the railway signal system,such as the fuzziness and randomness,which may affect the successful solution to the problem in a qualitative and quantitative manner.Aiming to solve such problems involving the use of fuzzy set theory and evidence theory,the paper would like tobring about a risk assessment method based on the aforementioned fuzzy set theory and evidence theory to accomplish such evaluations.To achieve the said purpose,we have first of all established a fuzzy set to use the fuzzy language to describe the risk factors on the basis of risk identification of the railway signal system.And,then,we have to manage to map out the obtained fuzzy information to define the risk levels characterized by the frame discernment under the fuzzy evidence theory.What is more,such fuzzy information can be synthesized and classified through the evidence theory.At this stage,we have also proposed an improved evidence theory based on the discount coefficient method in hoping to regulate the pieces of the conflicting or contradictory data and information.At this,it would be possible to use the analytical hierarchy process to determine and prove the relative degrees of importance of the risk contribution,in hoping to work out the risk assessment results by fusing the risk factor information and data based on the weighted average integrated function.Last of all,we have accomplished the risk assessment on the temporary speed limits and taken the functions for the radio block center as an example to verify the proposed risk assessment method.Thus,the assessment result proves to be of v2 level,indicating that the process has been described and defined in a detailed and rational approach in the paper.The final assessment result that we have obtained from the risk assessment practice proves consistent with the actual situation,and the method turns out to be rational,effective and feasi