Finite-Time Trajectory Tracking Control of Quad-Rotors With User-Defined Velocity Constraints: Theory and Experiment

Despite recent progress in the flight control design of quad-rotors, achieving precise trajectory tracking control with velocity constraints in tight spaces remains challenging. When operating in such environments, it is desirable for quad-rotors to maintain a safe and controlled velocity range to ensure mission success. To address this, this article presents a new finite-time trajectory tracking control approach for quad-rotors with velocity constraints. The approach includes a velocity-constrained virtual controller that generates thrust and desired attitude commands for the position loop, and a finite-time attitude control law that ensures rapid convergence of the actual attitude to the desired command. The convergence of the tracking error in the closed-loop quad-rotor system, as well as the satisfaction of velocity constraints throughout the flight, is theoretically demonstrated. Simulation and experimental results show the superiority of the proposed control strategy compared to existing methods.