Point-to-Point Motion Trajectory Generation for Uncertain Systems: A Closed-Form Solution

This paper investigates output feedback tracking control of Unmanned Aerial Vehicles using only the measured inertial coordinate. The output feedback control is based on two cascade high-gain observers combined with a full-state feedback control that is based on the backstepping approach. In this work, the backstepping controller is designed to solve the tracking control problem of the underactuated system. Then, an observer comprised of two cascaded high-gain observers with different speeds is considered; the faster observer provides estimates of the output position and velocity of the system in three dimensions and feeds a virtual nonlinear output to estimate the Euler angles (pitch, roll, and yaw) and angular velocity. We show that the equilibrium point of the full-state feedback control system under full knowledge of the system information is exponentially stable. The simulation results show that the output feedback control achieves the tracking control objective and recovers the performance of the state feedback control. Also, the simulation results show convergence and the boundedness of the estimation errors.