Robust Path Following Controllers for Quadrotor and Ground Robot

This work evaluates the robustness of control systems for a quadrotor tracking a two-wheeled ground robot. To guarantee the best motion tracking and stability, a Backstepping controller is adopted for each robot. The path following approach in the quadrotor controller removes any time dependence of the problem to improve the performance in presence of uncertainties and fast motion. A real-time path of the quadrotor is planned using the potential field method to track a moving ground robot target. The motion planning system provides the quadrotor with the appropriate attractive forces as a function of the relative position and velocity of the target with respect to the quadrotor. The implementation of the proposed controllers on real robots shows smooth convergence to the path with unsaturated control signals, in addition to smaller transient error and a stronger robustness.