Research On Collision Risk Under Free Flight Consider CNS And Collision Avoidance System

The mainly studied problem is collision risk assessment under the free flight. Free flight is a flight pattern which aims at reducing the airspace congestion and increasing capacity of airspace. In today's technology progress, the realization of the free flight is more and more possible. In order to ensure safety of flight in free flight airspace, it's necessary to establish a collision risk calculation model under the free flight so that evaluating the collision risk.In the first place, studying the main factors influencing the collision risk under the free flight, such as communication, navigation, surveillance and collision avoidance system,introducing its basic principle and main technical parameters.In the second place, synthesizing the main factors of influencing collision risk, studying the simulation of aircraft position error under the free flight and applying it to the establishment of the collision risk model. Doing the work from three aspects.Firstly, in the previous risk assessment research literature in free flight, which emphasis on collision risk calculation model and usually adopt the method of simple processing for the simulation of the aircraft position error, such as According to the time accumulating way of distribution and nothing related to the time of the random distribution. Based on the combination of the two kinds of simulation, putting forward a new simulation method of aircraft position error which is more conform to reality. Secondly, simulating the aircraft position error accurately, and applying it to the collision risk model. In the case of considering various influence factors of risk of collision, respectively using the improved Event model and the collision risk model based on conflict resolution, present the collision risk calculation model. Thirdly, In the process of calculating collision model, the estimation method of related parameters about aircraft conflict relief process is improved. This improvement is more suitable for small probability events of aircraft collision, which overcome the disadvantages of monte carlo method on the issue, such as the required sample size, sampling low efficiency of sampling.Finally, determining the minimum safety distance with free flight by the calculation results of the model.Comparing with the previous results of collision risk assessment underthe free flight, which explains the applicability and the accuracy of the model calculation results.