Dynamic modeling and control system design for a tail-sitter UAV

Abstract

This paper is concerned with the dynamic modeling and control system design based on a classical method for a Tail-Sitter UAV. The dynamic model of a Tail-Sitter UAV was found using the nonlinear aerodynamic models with Vortex Latex Method (VLM). 6-DOF (Degree of Freedom) dynamic equations, which include aerodynamic characteristics, are derived. The results from the dynamic modeling and system analysis study with aerodynamic characteristics allow to understand the dynamic properties. Based on LTI model for hover and horizontal flight, classical SISO control is deployed for vehicle stabilization. The controller for hover and horizontal flight is designed with the linear SISO control approach. Also, control system design based on the precise dynamic model make more accurate controller gain selection possible. The SISO multi-loop controller is then used as the low-level vehicle stabilization and it is integrated with the middle level waypoint navigator. Finally, the performance of the proposed approach is first validated in the numerical simulation and then in a series of flight test. In similarity experiments, a shrouded propeller system could show performance of controllers and verification of dynamic modeling. Therefore, we could conduct flight test of a Tail-Sitter UAV using proposed controller. Proposed controllers and dynamic model has sufficient accuracy and performance.