Robust quadcopter control with artificial vector fields.

This article presents a path tracking control strategy for a quadcopter to follow a time varying curve. The control is based on artificial vector fields. The construction of the field is based on a well known technique in the literature. Next, control laws are developed to impose the behavior of the vector field to a second order integrator model. Finally, control laws are developed to impose the dynamics of the controlled second order integrator to a quadcopter model, which assumes the thrust and the angular rates as input commands. Asymptotic convergence of the whole system is proved by showing that the individual systems in cascade connection are input-to-state stable. We also analyze the influence of norm-bounded disturbances in the control inputs to evaluate the robustness of the controller. We show that bounded disturbances originate limited deviations from the target curve. Simulations and a real robot experiment exemplify and validate the developed theory.