极值理论在飞机操纵系统安全性评估中的应用

飞机操纵系统是影响飞行安全的关键系统。针对飞机电传操纵系统安全性评估问题,提出了一种基于极值理论的操纵系统故障后的飞行风险小概率事件评估方法。总结了用极值理论评估飞行风险小概率事件的步骤,对比了不同坐标变化下的拟合优度,验证了双负指数法是逼近Ⅰ型极值分布的最佳方法。以某型飞机滚转角速度传感器故障后的飞行安全评估为例,得到了此时驾驶员不能排除该故障的风险概率和综合飞行风险。通过与军标中规定的安全性标准相对比,表明此时飞机能够满足安全性要求,从而为评估飞机操纵系统安全性提供了一种有效方法。

Application of Extreme Value Theory on Flight Safety Evaluation of Flight Control System for Aircrafts

Fly-By-Wire (FBW) system is safety-critical system for flight safety. Regarding safety evaluation problem of FBW system, flight risk small probability event evaluation method based on Extreme Value Theory (EVT) after flight control system''s failure is proposed. Step of evaluating flight risk based on EVT is summarized. By contrasting the fitting effects under different coordinate transformations, the result shows that double negative exponential is the best method of approaching extreme value distribution of type. Taking flight safety evaluation after execution failure of one aircraft for example, probability of unsuccessfully eliminating the failure for the pilot and the integrated flight risk are calculated. According to flight risk in military standard, this aircraft can satisfy the safety requirements. Then an available method of evaluating safety of aircrafts'' flight control system is proposed.