Real time flight dynamics model identification of tilt-rotor aircraft

Abstract

An improved real time identification method for tilt-rotor aircraft flight dynamics modeling is developed in this paper. A general parametric flight dynamics model which can be used for online identification purpose in all 3 flight modes is established, and an unideal noise model is also built in order to minimize the influences to the identification accuracy caused by measurement noise. An adaptive model structure identification algorithm is established by introducing local accuracy criteria, so that the time variant optimal model structure can be obtained in real time. A weighted recursive least squares algorithm is established for parameter identification, and a time variant weighting matrix is designed to provide best numerical performance of the identification procedure at any time. A comprehensive nonlinear flight dynamics model of a sample tilt-rotor aircraft is used to build a numerical simulation platform and identification results of the sample aircraft in fixed wing mode, helicopter model as well as transition mode are obtained based on simulation flight test. Finally, the flight dynamics model of an unmanned tilt-rotor aircraft in helicopter mode is identified by using the real flight test data. The identification results show that the real time identification method for tilt-rotor aircraft developed in this paper is effective, efficient and robust.