Study On Collision Risk Model Considering Uncertainty In Free Flight

Under the free flight environment, the original route in the airspace is not to exist, so that the pilot can choose flight path and speed freely. Compared with the present flight mode, it can largely remit the air traffic congestion and increase the airspace capacity. So by the assessment of the collision risk under the free flight, giving the minimum separation of aircrafts could be of great significance to ensure the flight safety.This paper mainly analyzes the uncertain factors causing collision risk, then the collision risk models under the free flight are established. The main work is as follows:1. Used the system dynamics, collision risk causal feedback flow diagram are drawn,which is useful for identifying collision risk factors. And then the collision risk effect of weight of each of these factors is evaluated, collision risk feedback mechanism analyzed. Above all, it can provide a theoretical basis to set up the collision risk model below.2. The communication navigation surveillance performance leads to the positioning errors of aircrafts, which has the characteristics of White Gaussian Noise. In the view of the positioning error with the Gaussian White Noise characteristics, the error probability is expressed as a sphereform probability outward from the theoretical position. According to the relative motion of the aircrafts, collision risk model based on Gaussian White Noise was established and finally solved to get the collision risk.3. The collision risk model based on switching system is built in combining the communication navigation surveillance performance, collision avoidance system and human factors. The latter two factors are intervened on the system under the specific cases. At last,referring to the data of presentation, the feasibility of the model is verified by an example.