A Virtual Method to Estimate the Aerodynamic Coefficients of UAV

Abstract

In this work, a new approach for aircraft aerodynamic behavior identification by using virtual simulation is proposed. Both theoretical and experimental aspects are presented. A simulation environment, Microsoft Flight Simulator, is used as the test platform. To make the communication with this environment possible, a real-time interface that allows the read and/or write from and to the shared memory layer of this flight simulator is developed. Using this interface, the virtual aircrafts sensors are read and the commands are written to the inputs control (thrust, elevators, ailerons, trims, and rudder). Also, an identification of the aerodynamic coefficients’ derivatives using the total least square technique is presented. The piloting law expression is toughly tied to those derivatives which are unknown and not always available. The aircraft aerodynamic model is then used to calculate the aerodynamic coefficients. We determine the aerodynamic performances of the wing which is based on the polar drag, the computation of the maximum lift-to-drag coefficient ratio and the determination of the moment in which the aerodynamic stall phenomenon appears.