Prediction on Nonlinear Flight Dynamics of a Quad-rotor UAV with rotor aerodynamic analysis under Gust

Abstract

Recently, studies on the flight dynamics of unmanned aerial vehicle (UAV) affected by gust have been performed. However, only few studies focused on the aspect of the robust controller design and those did not consider aerodynamic effect by gust. Therefore, the goal of this paper is establishing a non-linear flight dynamics simulation which is intended to analyze gust. First, the aerodynamic analysis is composed with dynamic inflow, blade element theory (BET), and ring vortex method for descent. A nonlinear flight simulation is constructed based on aerodynamic analysis and a procedure is established to verify it. To estimate the controller gain, system identification and parametric estimation are performed. Based on such estimation, a position controller is designed and reliability of the controller is validated by the two-point flight test. Additionally, wind tunnel test is performed and the trajectory of UAV shows a good tendency when compared with experiment. As a result, the nonlinear flight dynamics presented in this paper will be used to estimate the trend of UAV dynamics under gust.