A state/event fault tree(SEFT)is a modeling technique for describing the causal chains of events leading to failure in software-controlled complex systems.Such systems are ubiquitous in all areas of everyday life,and ...A state/event fault tree(SEFT)is a modeling technique for describing the causal chains of events leading to failure in software-controlled complex systems.Such systems are ubiquitous in all areas of everyday life,and safety and reliability analyses are increasingly required for these systems.SEFTs combine elements from the traditional fault tree with elements from state-based techniques.In the context of the real-time safety-critical systems,SEFTs do not describe the time properties and important timedependent system behaviors that can lead to system failures.Further,SEFTs lack the precise semantics required for formally modeling time behaviors.In this paper,we present a qualitative analysis method for SEFTs based on transformation from SEFT to timed automata(TA),and use the model checker UPPAAL to verify system requirements’properties.The combination of SEFT and TA is an important step towards an integrated design and verification process for real-time safety-critical systems.Finally,we present a case study of a powerboat autopilot system to confirm our method is viable and valid after achieving the verification goal step by step.展开更多
针对风力发电机组频发的火灾事故,首先从人-机-环-管角度出发,通过统计分析近20年来全球81起风力发电机组火灾事故案例,得到了21项风力发电机组火灾事故的影响因素;然后通过事故树分析(fault tree analysis,FTA)法演绎推理得到了风力发...针对风力发电机组频发的火灾事故,首先从人-机-环-管角度出发,通过统计分析近20年来全球81起风力发电机组火灾事故案例,得到了21项风力发电机组火灾事故的影响因素;然后通过事故树分析(fault tree analysis,FTA)法演绎推理得到了风力发电机组火灾事故各基本事件的逻辑关系,并根据结构重要度进行了火灾事故致因的定性分析;接着采用模糊层次分析(fuzzy analytic hierarchy process,FAHP)法,将事故树的基本事件从人、机、环、管4个方面整合,构建出风力发电机组火灾事故致因评价指标体系,并以结构重要度系数的顺序为模糊判断矩阵的赋值依据,进行了火灾事故致因的定量分析;最后,根据综合分析结果提出了风力发电机组火灾事故的对策措施。结果表明:机和环境的不安全因素是引发火灾事故的主要致因;电气设备故障和雷击是最主要因素。该研究成果可为风力发电机组的火灾防治提供理论参考。展开更多
为了分析机场跑道侵入的影响因素,更有针对性地对预防机场跑道侵入提出合理建议,结合相关信息通告中统计的数据,首先从人员因素、环境因素、设备因素和管理因素4个方面分析跑道侵入的事故成因,并建立了故障树(Fault Tree Analysis,FTA)...为了分析机场跑道侵入的影响因素,更有针对性地对预防机场跑道侵入提出合理建议,结合相关信息通告中统计的数据,首先从人员因素、环境因素、设备因素和管理因素4个方面分析跑道侵入的事故成因,并建立了故障树(Fault Tree Analysis,FTA)模型和贝叶斯网络(Bayesian Network,BN)模型,然后利用软件Netica对贝叶斯网络模型进行了后验概率推理与敏感性分析,最后根据分析结果提出了相应的建议。结果表明,人员因素影响程度最大,其次是管理因素,而环境因素和设备因素的影响程度相对偏小。展开更多
送料系统故障发生是影响剪切机正常运行的主要因素,在分析送料系统工作原理的基础上提出基于故障树分析法(fault tree analysis,FTA)对送料系统进行可靠性分析,并运用MATLAB开发出可靠性数据分析平台,对送料系统的试验数据进行处理,精...送料系统故障发生是影响剪切机正常运行的主要因素,在分析送料系统工作原理的基础上提出基于故障树分析法(fault tree analysis,FTA)对送料系统进行可靠性分析,并运用MATLAB开发出可靠性数据分析平台,对送料系统的试验数据进行处理,精确地计算其可靠度、失效率、平均故障前时间(mean time to failure,MTTF)等可靠性参数。研究结果表明:销轴和传动轴是影响送料系统可靠性最主要零件;高辐照环境是影响送料系统可靠性的最主要因素;可靠性数据分析平台可实现对送料系统可靠性试验数据可视化、自动化和实时化处理。展开更多
基金supported by the National Natural Science Foundation of China(11832012)
文摘A state/event fault tree(SEFT)is a modeling technique for describing the causal chains of events leading to failure in software-controlled complex systems.Such systems are ubiquitous in all areas of everyday life,and safety and reliability analyses are increasingly required for these systems.SEFTs combine elements from the traditional fault tree with elements from state-based techniques.In the context of the real-time safety-critical systems,SEFTs do not describe the time properties and important timedependent system behaviors that can lead to system failures.Further,SEFTs lack the precise semantics required for formally modeling time behaviors.In this paper,we present a qualitative analysis method for SEFTs based on transformation from SEFT to timed automata(TA),and use the model checker UPPAAL to verify system requirements’properties.The combination of SEFT and TA is an important step towards an integrated design and verification process for real-time safety-critical systems.Finally,we present a case study of a powerboat autopilot system to confirm our method is viable and valid after achieving the verification goal step by step.
文摘目的洪水是影响尾矿库安全的重要因素,明晰洪水对尾矿库的风险传导路径有利于帮助识别关键风险因素,优化防控措施。方法结合文献计量法和专家决策筛选出尾矿库洪水风险的重要影响指标,利用解释结构模型(interpretative structural modeling,ISM)对指标层次进行划分,最后基于事故树分析(fault tree analysis,FTA)解析灾害的演化路径,并提出相应预防措施。结果结果表明:(1)基于文献计量法总共筛选出24个尾矿库洪水风险影响因素,结合平均权重值与专家经验确定10个相对重要的尾矿库洪水风险影响因素;(2)基于ISM计算得出10个影响因素和洪水风险间的相互影响关系,确定尾矿库洪水灾害的直接、间接和最根本影响因素;(3)结合ISM和事故案例,建立尾矿库洪水灾害事故树,通过布尔代数运算得出18种致灾路径和9种预防事故的路径;(4)分析事故树的结构重要度后发现对尾矿库洪水风险影响最大的事件是排洪能力不足、洪峰流量大和初始浸润线埋深浅。结论提出的文献计量法、ISM与FTA相结合的方法不仅实现了客观指标筛选与系统建模的融合,而且为尾矿库防洪实现从“被动应对”向“主动阻断”的转变提供了理论支撑。
文摘为了分析机场跑道侵入的影响因素,更有针对性地对预防机场跑道侵入提出合理建议,结合相关信息通告中统计的数据,首先从人员因素、环境因素、设备因素和管理因素4个方面分析跑道侵入的事故成因,并建立了故障树(Fault Tree Analysis,FTA)模型和贝叶斯网络(Bayesian Network,BN)模型,然后利用软件Netica对贝叶斯网络模型进行了后验概率推理与敏感性分析,最后根据分析结果提出了相应的建议。结果表明,人员因素影响程度最大,其次是管理因素,而环境因素和设备因素的影响程度相对偏小。
文摘送料系统故障发生是影响剪切机正常运行的主要因素,在分析送料系统工作原理的基础上提出基于故障树分析法(fault tree analysis,FTA)对送料系统进行可靠性分析,并运用MATLAB开发出可靠性数据分析平台,对送料系统的试验数据进行处理,精确地计算其可靠度、失效率、平均故障前时间(mean time to failure,MTTF)等可靠性参数。研究结果表明:销轴和传动轴是影响送料系统可靠性最主要零件;高辐照环境是影响送料系统可靠性的最主要因素;可靠性数据分析平台可实现对送料系统可靠性试验数据可视化、自动化和实时化处理。
