Topological space construction of flight risk probabilities during wake encountering
Avic Shanxi · 2014
Under the background of increasing wake vortex problems,wake risk probability topology was built using complex human-machine-environment theory and multivariate extreme value theory.First,three-dimensional wake extreme parameters required for assessing the risk were extracted based on Monte Carlo method.And the one-dimensional extreme parameters were verified to meet generalized extreme value(GEV) distribution.Second,the four parameters and adaptive variable weight(FPAVW) Copula was proposed for modeling three-dimensional extreme parameters.The results of fitting test show FPAVW Copula model has higher accuracy than the other models.Third,flight risk probability in each corresponding grid node was evaluated on the basis of using Copula model to describe all the extreme values in three-dimensional wake space.Then the risk's 2D and 3D topological structures at different stages of wake vortex were analyzed.The work is an effec-tive complement to aircraft system safety assessment theory and method,which provides reference for research directions such as wake navigation control,risk aversion,airport safety interval improvement,and environmental risks visualization.It is also suitable for comparative analysis of flight risk probabilities under different circumstances.