Probabilistic Model-based Research Of Aircraft Conflict Detection Technique

With the rapid development of China's economy, the civil aviation industry presents prosperity flourish. Because of the complicated airspace environment and the rapid growth of air traffic flow, the probability of aircraft conflicts is greatly improved. Air traffic control system is an important tool for air traffic controllers to maintain order in air traffic, and flight conflict detection algorithm is the essential method to prevent the flight conflict from occurring.The famous aircraft conflict detection algorithms based on probabilistic model contain the analytical algorithm which was proposed by Paielli and the random algorithm which was proposed by Prandini. Paielli considered the joint covariance as a constant value during the encounter process, and calculated the approximate conflict probability. Prandini chose N time points in the time to look ahead and calculated conflict probability by using the random method, then got the maximum conflict probability. After the study, the calculation result contains certain error by Paielli's algorithm, and these two famous algorithms can produce a contradiction in certain conditions because of the different judgment criterions.The analytical model proposed by Paielli is used in this paper, and the rectangle which is tangent to the ellipse is used to calculate approximately the conflict probability. Besides, in order to improve the accuracy of the conflict probability, the maximum rectangle and the maximum triangle in the error surface can be eliminated. By approximating Gaussian cumulative distribution function, the integration of two-dimensional normal distribution function in the triangle can be obtained accurately. Through the verification of the numerical integration method, this improved algorithm is available and it can be applied into the aircraft conflict detection system of the next generation air traffic control system to prevent the aircraft conflict from occurring.