DESIGN AND FLIGHT TEST OF A SMALL TRI-ROTOR UNMANNED VEHICLE WITH A LQR BASED ONBOARD ATTITUDE CONTROL SYSTEM

摘要

This paper presents design and implementation of a tri-rotor UAV (unmanned aerial vehicle) system with single tilt dynamics on a tail rotor for the flight dynamic control. The analytic aerodynamic model of the suggested tri-rotor UAV is presented based on the force and moment equation and its parameters are calculated through an experiment. For the flight dynamics control, the equilibrium point is computed through a numerical analysis and based on it, the linearized model of the single tilt tri-rotor is developed. An optimal control law via the LQR method is applied for the attitude control of the UAV system and simulation results validated the performance under both linear and nonlinear models. Finally, the single tilt tri-rotor system is manufactured and onboard avionics are implemented using a small-sized AHRS (attitude and heading reference system) and real-time processor module. Flight tests demonstrated that the designed attitude controller operates successfully with a fast yaw motion control performance.