Tracking control of vertical taking-off and landing vehicles with parametric uncertainty

This paper considers the position and attitude tracking control of a quadrotor with inertia parameter uncertainty. With the aid of the cascade structure of the dynamics of the system, an immersion and invariance observer is proposed to estimate the unknown mass of the system first. Secondly, a saturation controller is designed for the thrust force. Thirdly, a virtual controller is proposed for the angular velocity of the quadrotor with the aid of a nonlinear transform of the Euler angles. Finally, adaptive and robust controllers are proposed for the torque input of the quadrotor to deal with the unknown inertia moment of the system. Simulation results show the effectiveness of the proposed algorithms.