Research On Flight Safety Situation Assessment Method Of Complex Low-altitude Airspace

With the deepening of the reform and opening up of low-altitude airspace management,the mixed operation of various general aviation activities in low-altitude airspace will gradually appear,and it is vulnerable to various random factors such as terrain obstacles,bad weather,birds and UAVs.And there are large potential flight safety hazards,which increase the difficulty of scientific control of low-altitude flight safety.So,it is urgent to study the assessment and monitoring of complex low-altitude flight safety situation in order to provide some theoretical and methodological support for the safe operation and management of low-altitude airspace.Firstly,this paper clarifies the operational characteristics of low-altitude airspace from three aspects: airspace environment,operational rules,requirements and characteristics of general aviation activities.Based on the analysis of flight situation safety characteristics,four factors affecting complex low-altitude flight safety situation are extracted,including conflict factors,environmental factors,traffic factors and operational factors,and the law of its influence on complex low-altitude flight safety situation is analyzed,which lays a research foundation for the establishment of assessment index of complex low-altitude flight safety situation.Secondly,according to the connotation and operational characteristics of flight safety situation in low-altitude airspace,indexes are established from two dimensions: conflict risk and extrication behavior.The coefficient of variation-importance-correlation coefficient is used to screen out the key indexes of flight safety situation assessment in complex low-altitude airspace,which ensures that the indexes are independent of each other and have a significant impact on the assessment.The selected indexes are verified by different simulation experiments.The results show that the three key indexes selected are: the conflict rate,the collision risk intensity and the ratio of altitude adjustment are both effective and universal.Finally,according to the requirements of complex low-altitude flight safety situation management and control,the variable weight evaluation model based on multi-dimension connection number and the weighted comprehensive assessment model based on system clustering are established respectively.Through two groups of simulation experiments,the assessment results of the two models are compared,and their advantages,disadvantages and applicable conditions are analyzed.The assessment results of the two models are consistent with the actual simulation operation,which shows the validity of the assessment models.