New technology from Japan for realization of safety function against deviations from normal operating-range in control laws according to international standards

本研究明确了控制律中的安全功能，以减少控制系统中物理值偏离其正常工作范围的事件频率。这些偏差不仅可以由系统不稳定引起，也可以由瞬态响应的波动引起。为了定量地确定安全函数在控制律中的贡献，以降低风险，本研究建立了一个定量评估框架，利用暂态响应波动的性能指标来获得偏差的频率。此外，本研究还建立了控制律中安全功能的实现框架，可以根据IEC 61508等国际安全标准对普通安全相关系统进行风险降低的补充。

This research clarified safety function in control laws to reduce the frequency of events that a physical value in a control system deviates from its normal operating-range. The deviations can be caused not only by system destabilization but also by fluctuations of transient responses. In order to quantitatively establish the contribution of the safety function in control laws for risk reduction, this research established a quantitative assessment framework for obtaining the frequency of the deviations by using a performance index for the fluctuations of transient responses. Furthermore, this research also established a realization framework for the safety function in control laws, which can supplement ordinary safety-related systems in risk reduction according to international safety standards such as IEC 61508.