失效事件“系统表决值错误”的失效率算法研究

Research on Failure Rate Algorithm for Failure Event“Systematic Voting Error”

因为信号源、信号传输线缆、信号采集等环节都可能出现故障,导致电传飞行控制系统获得错误的信号;即使对信号进行监控表决,仍可能因为多个信号错误而输出错误的表决值。按CCAR25.1309的要求,需要量化的确认上述事件发生的概率与事件的安全性影响等级相适应。根据系统监控表决逻辑的特征,通过增加假设,给出系统因为信号错误导致的失效事件——“系统表决值错误”的失效率计算方法;使用该方法可以给出保守但符合概率计算原理的量化结果,可用于表征系统对CCAR25.1309要求的符合性。

Failures in the signal source,signal transmission cable,signal acquisition,etc.can result in incorrect signals being ob-tained by the fly-by-wire flight control system.Even if the signals are monitored and voted on,it is still possible to output an incorrect vote value due to multiple signal errors.As required by CCAR 25.1309,there is a need to quantitatively confirm that the probability of occurrence of the above events is commensurate with the safety impact level of the event.Based on the characteristics of the system's monitoring and voting logic,a method for calculating the failure rate of the system due to a signal error,“system voting value error”,is given by adding assumptions.Using this method gives a conservative but probabilistic quantitative result that can be used to charac-terize the system’scompliance with the requirements of CCAR 25.1309.