安全与环境学报

针对铁路信号系统风险评估中定性概念模糊性和随机性共存的特点,提出了一种基于云模型的模糊综合评判法,用于对列控中心的临时限速功能进行风险评估。在确定因素集、评语集和权重集的基础上,利用云模型中的逆向云发生器将常规模糊综合评判法中的综合评判矩阵和权系数矩阵转换为以云模型数字特征表示的矩阵,然后进行模糊综合评判得到评价云模型。通过MATLAB将评语云模型和评价云模型分别仿真显示,从而确定评估对象的最终风险等级。结果表明,利用云模型构建的隶属度函数能够充分表征风险因子的模糊性和随机性,评估结果直观、符合实际情况。

The paper intends to introduce a comprehensive safety evaluation method based on the cloud model for evaluating the railway signal system. The reason and the need for us to pick up such a subject is that the existing evaluation methods fail to reflect the functions of the random nature of the risk factors in the riskprevention assessment area. Therefore,we think it necessary to put forward a fuzzy comprehensive evaluation method based on the cloud model to assess the risk of the temporary speed limit function for the train control center. In proceeding with our research, first of all,we have set up an assessment system based on the cloud model theory including the factor setting,the weighing factors setting and that of the evaluation criteria. Secondly,we have worked out a comprehensive evaluation matrix and weighing matrix of the conventional fuzzy comprehensive evaluation factors and the ways to transform them into the matrixes represented in numerical features via the backward cloud generator. What is more, we have also taken all the comprehensive evaluation matrix and weighing matrix based on the cloud model into comprehensive account so as to get the desirable comprehensive evaluation results. In addition,the evaluation process has also been included into the model so as to determine the relative degrees of the importance for evaluating the risk factors and the membership functions in the fuzzy way. And,finally,the group decisions as to the evaluation results can be gained by the synthetically aggregated cloud model when they were put into the forward cloud generator through proper calculation. Thus,what we would like to do is to make the cloud drop with the properties of the risk grades and the assessment results easy to be simulated by MATLAB when determining the final risk grades of the temporary speed limit function for the train control center. The practical assessment results show that the application of the cloud model in the reconstruction of the membership functions is favorable to realize the transition from the accurate data into the quality data by combining the fuzziness and randomness,so as to make the assessment results of the suggested methods visual and dependable,and increase the visual and virtual intuitiveness of the reference data and information of the risk assessment.