自由飞行下基于分段维纳过程的碰撞风险研究

Study on Free Flight Collision Risk Based on Piecewise Wiener Process

在自由飞行下,飞机的碰撞风险与通信导航监视(CNS)定位误差、机载防撞系统可靠性等因素有关。CNS引起的定位误差可视为正态分布,以机载防撞系统告警区为界,在告警区外飞机视为匀速,相对距离视为一般维纳过程;在告警区内飞机为避撞进行航迹和速度调整,视为变速,相对距离视为伊藤过程。根据此相对运动特点,建立了基于维纳过程的分段碰撞概率模型,并对不同初始状态时的情形进行求解。算例结果表明了模型的可行性。

In free flight ,the aircraft collision risk is mostly due to the positioning error of communication , navigation and surveillance （ CNS） ,and the reliability of airborne collision avoidance system ,which is u-sually TCASⅡ.With CNS positioning errors regarded as normal distribution and the warning area of TCASⅡused as the boundary ,aircrafts outside the warning area deem uniform ,and the relative distance is regarded as the general Wiener process;the aircrafts inside the area ,as to avoid collision ,will adjust the tracks and speeds ,thus the motion is variable motion ,and the relative distance follow Ito process .Accord-ingly,a model of collision risk based on piecewise Wiener process is established and calculated under many different initial states .The results show the feasibility of the model .