基于故障的系统安全风险分析与评估方法研究

发布时间：2018-03-08 16:19

本文选题：安全风险　切入点：系统安全性　出处：《国防科学技术大学》2013年博士论文　论文类型：学位论文

【摘要】：随着科学技术的发展,系统结构越来越复杂,功能越来越强大,性能不断提升,同时对其安全性的要求也越来越高。然而,传统的安全风险评估方法并不能准确全面地评估出现代系统的安全风险,掌握风险状况,指导人们找出系统的薄弱环节,提出科学的控制措施,安全风险评估的理论与方法亟待完善。为此,论文提出了一套系统安全风险分析与评估方法,研究了系统风险的概念与度量方法,讨论了系统安全风险状态评估技术,分析了部件失效对系统安全风险的影响,给出了安全风险的不确定性评估方法。主要内容包括:(1)系统风险的概念与度量方法评估系统安全风险的首要任务是掌握系统风险的概念与度量方法,该部分研究了部件失效与安全风险的关系,始于部件失效的风险传播,静态与动态的风险度量方法,最后在上述研究的基础上提出了系统风险评估的框架及内容。(2)系统安全风险状态的评估方法该部分从系统状态的描述出发,首先给出了系统风险状态的划分,针对系统的不同特征,详细讨论了二态、多态和过程控制系统风险状态的划分。其次,给出了系统风险概率、置信区间和高风险状态不可接受概率的计算方法。随后,就系统到达高风险状态的时间展开了探索研究,建立了高风险状态到达时间的评估方法,通过该法能估算出高风险状态到达不可接受程度的时间和系统转移到高风险状态的时间。(3)部件失效对系统安全风险影响的分析方法研究部件对系统安全风险的影响可以指导识别薄弱环节,控制系统风险,是安全风险评估的重要工作。该部分内容主要包含部件风险重要度的分析、风险临界状态及关键部件识别、诊断分析,针对这些问题分别讨论了二态、多态和过程控制系统中部件失效对系统安全风险的影响。(4)安全风险的不确定性评估方法考虑到系统的高安全性要求及不确定性的影响,研究了不确定性的概率量化方法,并将影响系统安全风险评估结果的不确定性分为认知不确定性和随机不确定性,讨论了包含不确定性时的安全风险裕度,结合系统处于高风险状态概率和系统受到随机冲击的风险评估例子,应用QMU方法,得到了系统安全风险评估的不确定结果,可用以辅助风险决策。应用论文提出的系统安全风险分析与评估方法,针对不同特征系统,既可得到更加准确全面的系统风险状态信息,又可从安全风险的角度获取部件失效对系统的影响,还能充分考虑评估结果的不确定性,用以支持风险决策和控制,具有较高的理论参考和推广应用价值。
[Abstract]:With the development of science and technology, the system structure is becoming more and more complex, the function is becoming more and more powerful, the performance is improving constantly, at the same time, the requirement of its security is higher and higher. The traditional safety risk assessment method can not accurately and comprehensively evaluate the security risk of modern system, grasp the risk situation, guide people to find out the weak links of the system, and put forward scientific control measures. The theory and method of security risk assessment need to be improved urgently. Therefore, this paper puts forward a set of system security risk analysis and assessment method, studies the concept and measurement method of system risk, and discusses the technology of system security risk state assessment. The effect of component failure on system safety risk is analyzed. In this paper, the uncertainty assessment method of security risk is given. The main content includes the concept and measurement of system risk. The first task of evaluating system security risk is to master the concept and measure method of system risk. In this part, the relationship between component failure and safety risk is studied, which begins with the risk propagation of component failure, static and dynamic risk measurement. Finally, on the basis of the above research, the paper puts forward the framework and content of system risk assessment. The method of system security risk state evaluation is put forward. In this part, starting from the description of system state, the partition of system risk state is given. According to the different characteristics of the system, this paper discusses in detail the division of the risk states of two-state, polymorphic and process control systems. Secondly, the calculation methods of system risk probability, confidence interval and unacceptable probability of high risk state are given. In this paper, the time of reaching the high risk state of the system is studied, and the evaluation method of the arrival time of the high risk state is established. The method can estimate the time of reaching the unacceptable degree of high risk state and the time of system transition to high risk state. The method of analyzing the effect of component failure on system security risk study the influence of components on system security risk. Response can guide the identification of weak links, Controlling system risk is an important work of safety risk assessment. This part mainly includes the analysis of component risk importance, the critical state of risk and the identification of key components, diagnosis and analysis. In view of these problems, two states are discussed respectively. Effect of component failure on system safety risk in polymorphic and process control systems; uncertainty assessment method for security risk taking into account the high security requirements of the system and the influence of uncertainty, probabilistic quantification method of uncertainty is studied. The uncertainty that affects the result of system security risk assessment is divided into cognitive uncertainty and stochastic uncertainty, and the margin of security risk is discussed when uncertainty is included. The uncertain results of the system security risk assessment are obtained by using the QMU method combined with the examples of the probability of the system in high risk state and the risk assessment of the system subjected to random shocks. It can be used to assist risk decision. By using the system security risk analysis and evaluation method proposed in this paper, more accurate and comprehensive system risk state information can be obtained according to different characteristic systems. The influence of component failure on the system can also be obtained from the point of view of safety risk, and the uncertainty of evaluation results can be fully considered to support risk decision and control. It has high theoretical reference and application value.
【学位授予单位】：国防科学技术大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：X913

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