Abstract
This paper proposes a two loops control system structure for position and attitude of the Quadrotor flying vehicle. To control the Quadrotor’s center of gravity position in the instantaneous horizontal inertial planes, a small disturbance linearization-based Proportional-Derivative controller is employed in the outer (position) loop to provide reference pitch and roll tilting commands to the inner (attitude) loop. The outer loop also generates the thrust command required to track desired altitude trajectories. The inner loop utilizes a novel Adaptive Robust Generalized Dynamic Inversion (ARGDI) control design that is made by augmenting a direct adaptive control element in the baseline Robust Generalized Dynamic Inversion control system. The adaptive control law is obtained via a control Lyapunov function, and it aims to reduce the dependency of the control system on the geometric and inertia parameters of the Quadrotor in order to overcome control performance degradation due to modeling and parametric uncertainties, and due to external wind disturbances and dynamic scaling of the Moore-Penrose Generalized inverse. Computer simulations are performed in the Matlab/Simulink environment on a six DOFs Quadrotor model to demonstrate the robust globally asymptotically stable performance of the two loops control system. Additionally, performance of the inner ARGDI attitude control loop is tested on an experimental Quanser’s three DOFs Hover test bench.