Cascaded energy based trajectory tracking control of a quadrotor

This paper presents a cascaded nonlinear state feedback control law for a quadrotor, which achieves asymptotic tracking of a predefined position and heading reference trajectory. The inner-loop attitude controller and the outer-loop position controller reflect the cascade structure of the quadrotor dynamics and are designed independently using an energy shaping approach. The closed loop tracking error dynamics form a nonautonomous nonlinear cascade for whose zero equilibrium we prove almost global asymptotic stability. Experimental results show the performance of the control concept.