Reliability Optimization of Safety Monitoring and Protective Systems

本研究提出一种安全监控系统的最佳逻辑结构，以最小化失效-危险失效或失效-安全失效所造成的预期总损失.考虑了由多个通道组成的安全监测系统。该问题是当通道按照事故发生机制逻辑连接时，为每个通道设计一个最优的相干结构。对于单通道系统，证明了最优通道结构为<k^*> -out-of-n：G，且<k^*>可以解析计算。对于多信道系统，最优信道结构为n中取k：G，该问题可归结为一个非线性整数规划问题，可采用扩展的Lawler和Bell方法求解。上述结果被推广到覆盖更一般的优化的逻辑结构，而不假设ad-hoc信道连接.为整个保护系统开发了最佳停机逻辑，该保护系统由驱动器和电源组成。 ...更多信息 执行、判断和感测部分。最佳关闭逻辑由开关函数确定。对于具有可靠判断和驱动部分的系统，可以根据传感部分的可靠性信息确定最佳停机逻辑.最优动态逻辑是为安全监控系统开发的，其中术语“动态”意味着每当获得新的标称数据时，逻辑被重构。最优动态逻辑由监测数据历史的切换函数确定，并且最小化在下一监测时刻由两个故障引起的预期损害.为提高工厂的可用性和安全性，提出了多传感器系统诊断的最优决策逻辑。由两种故障模式引起的预期损失被最小化，并且所得到的最佳诊断逻辑由开关函数的签名确定，该开关函数又表示诊断的效率。如果利用测量数据的重要性排序，则可以大大简化最优逻辑的解析表示。少

This study introduces an optimal logic structure of a safety monitoring system to minimize the expected total loss incurred upon fail-dangerous failures or fail-safe failures.1. The safety monitoring system composed of several channels are considered. The problem is to design an optimal coherent structure for each channel when the channels are logically connected according to an accident occurence mechanism. For the one-channel system, the optimal channel structute is proven to be <k^*> -out-of-n: G, and <k^*> can be calculated analytically. For the multi-channel system, the optimal channel structure is a k-out-of-n: G, and the problem is formulated as a non-linear integer programming which can be solved by the extended Lawler and Bell's method. The above results are generalized to cover more general optimization of the logic structure without assuming ad-hoc channel connections.2. The optimal shut-down logic is developed for the overall protective system, which is composed of the driv … More ing, judging, and sensing sections. The optimal shut-down logic is determined by a switching function. For the system with reliable judging and driving sections, the optimal shut-down logic can be determined based on the reliability information of the sensing section.3. The optimal dynamic logic is developed for safety monitoring systems, where the term "dynamic" means that the logic is reconstructed every time when new nomitored data are obtained. The optimal dynamic logic is determined by a switching function of a history of monitored data, and it minimizes an expected damage caused by the two failures at the next monitoring time.4. The optimal decision logic for diagnosis of multi-sensor systems is developed to improve plant availability and safety. An expected loss caused by the two failure modes is minimized, and the resultant optimal diagnostic logic is determined by signatures of a switching function which, in turn, expresses efficiency of the diagnosis. An analytic representation of the optimal logic can be simplified considerably if importance rankings of measurement data are exploited. Less