The Longitudinal Modeling of a New Concept V/STOL UAV in Transition Flight by Using the Method of System Identification
Songlin Ma, Weijun Wang · 2018
Based on the mathematical modeling of the conventional aircraft, a longitudinal model is established in a transition flight phase for a new concept vertical/short takeoff and landing (V/STOL) UAV [1]. Due to the particularity of aircraft layout, the aerodynamic force and moment acting on the wing are non-linear and time-varying in the transition flight phase. In this paper, an identification method of recursive least squares (RLS) with a forgetting factor is adopted to identify the coefficients of time-varying aerodynamic force and moment and propeller deflected slipstream force and moment in the transition flight phase. Then the specific parameters were examined by comparing the results of flight test of this V/STOL UAV. The results justify the longitudinal model in transition flight phase. The recursive least squares method with the forgetting factor can identify the relevant parameters of this V/STOL UAV.