Flight control of a rotary wing UAV - a practical approach

This paper presents a novel application of the two-time scale controller for the full envelop flight control of a Rotary wing Unmanned Aerial Vehicle (RUAV). In this paper flapping and servo dynamics, important from a practical point of view, is included in the RUAV model. The two-time scale controller takes advantage of the `decoupling¿ of the nonlinear translational and rotation dynamics of the rigid body, resulting in a two-level hierarchical control scheme. The inner loop controller (attitude control) tracks the attitude commands and sets the main rotor thrust vector, while the outer loop controller (position control) tracks the reference position and control the flapping angles and the tail rotor thrust vector. High fidelity RUAV simulation results are used to demonstrate the control performance. Simulation results show acceptable performance of the proposed two-time scale controller. The comparison of control inputs between the proposed two-time scale controller and an already implemented PID controller show that this controller is suitable for practical implementation.