Uzair Ansari, Abdulrahman H. Bajodah, and Mirza Tariq Hamayun
Quadrotor control, Robust Generalized Dynamic Inversion, Adaptive Non-singular Terminal Sliding Mode
A Robust two-loops structured control system design for
Quadrotor’s position/attitude trajectory tracking is proposed. The aim of the outer loop is to provide the roll/pitch tilting commands to the inner loop, which in turns generates the tilting angles that control the quadrotor’s center of gravity in the horizontal plane. The outer loop
utilizes Robust Generalized Dynamic Inversion of a prescribed asymptotically stable differential equation in the deviation function of the horizontal position coordinates from their reference trajectories. The inner loop employs an adaptive Non-singular Terminal Sliding Mode to control the tilting angles, in addition to controlling the yaw attitude angle and the vertical position coordinate. The proposed scheme solves the singularity avoidance problems of generalized inversion and sliding mode control, and it guarantees closed-loop stability. Numerous simulations are conducted on a six degrees of freedom quadrotor model in the presence of parametric variations, unmodeled dynamics, and external disturbances.