Y.V. Gridnev - Ph.D. (Eng.), Leading Research Scientist, Physical-Technical Institute of National Academy of Sciences of Belarus Y.F. Yatsyna - Ph.D. (Eng.), Director of Scientific and Production Center, Physical-Technical Institute of National Academy of Sciences of Belarus S.A. Rak - Research Scientist, Physical-Technical Institute of National Academy of Sciences of Belarus A.G. Ivanov - Research Scientist, Physical-Technical Institute of National Academy of Sciences of Belarus. E-mail: maks.uav@gmail.com

A stochastic model of the ACS of the UAV, which implements the UAV flight along the predetermined path on the map according to the chosen route, capture and automatic tracking for the specified moving object, was developed. This model allows to optimize the structure of flight control systems for UAVs with specified accuracy characteristics and to choose its settings according to the specific technical characteristics of the device. The structural model consists of mapping software in a geographic coordinate system, five UAV control loops, sub-model of aerodynamic forces and moments according to the standard atmospheric parameters, sub-model of UAV glider, Kalman filters and strapdown inertial navigation system (SINS) utilizing quaternion. Numerous stochastic modeling of the ACS allowed to determine the boundaries of flight stability and UAVs control. Also modeling allowed to determine boundaries of stability of the control loop on the Euler angles, speed and altitude, and to determine the error transients, as well as dynamic and fluctuation errors in common flight control loop