基于证据理论和贝叶斯网络的TIS系统风险评估

Risk Assessment of Train Control Center and Interlocking Integrated System Based on Evidence Theory and Dynamic Bayesian Network

  • 摘要: 目前我国列控联锁一体化系统处于试验阶段,研究列控联锁一体化系统的风险评估对其可靠运行具有重要意义。针对列控联锁一体化系统风险评估中存在的不确定性及风险随时间发生变化的问题,提出基于证据理论和动态贝叶斯网络的列控联锁一体化系统风险评估方法。首先,构建列控联锁一体化系统故障树,并将其转化为动态贝叶斯网络模型;然后,引入模糊集理论和证据理论来确定动态贝叶斯网络的参数,利用动态贝叶斯网络的双向推理、重要度分析等方法,分析影响该系统可靠运行的关键风险因素;最后,利用专家打分法量化风险损失,通过绘制风险矩阵确定系统的风险等级。仿真结果表明:列控联锁一体化系统的风险等级属于铁路安全标准EN 50126中“Ⅳ级(可接受的风险)”,通信单元中与转辙机和轨道电路的通信接口及目标控制器单元为系统的薄弱环节。

     

    Abstract: Train control center and interlocking integrated system is in the experimental stage in China at present.It is of great significance to study the risk assessment of the train control center and interlocking integrated system for its reliable operation.To solve the problems of uncertainty and risk changing with time in the risk assessment of train control center and interlocking integrated system, a risk assessment method of train control center and interlocking integrated system based on evidence theory and dynamic Bayesian network is proposed.Firstly, the fault tree of train control center and interlocking integrated system is constructed and transformed into dynamic Bayesian network.Then, the fuzzy number is introduced to determine the failure rate of the basic event, and the state that expresses the cognitive uncertainty is introduced into the new state space through the evidence theory to determine the parameters of the dynamic Bayesian network.The key risk factors affecting the reliable operation of the system are found out by using the bidirectional reasoning, importance and sensitivity analysis of dynamic Bayesian network.Finally, the expert scoring method is used to quantify the risk loss, and the risk level of the train control center and interlocking integrated system is determined by drawing the risk matrix.The simulation results show that the risk level of the Train control center and interlocking integrated system belongs to the "IV(acceptable risk)" in the railway safety standard EN 50126.The communication interface with switch machine and track circuit and the object controller unit in the communication unit are the weak links of the system, so it is necessary to strengthen the risk control of the communication unit and the object controller unit.

     

/

返回文章
返回