Barrier Lyapunov-based Nonlinear Trajectory Following for Unmanned Aerial Vehicles with Constrained Motion

This paper addresses the problem of three-dimensional trajectory following of unmanned aerial vehicle, specifically, quadrotor, while considering the restrictions on its flying conditions during practical operations. To ensure that the quadrotor follows a desired trajectory while satisfying the constraints imposed on its motion, the control inputs are derived using the concepts of barrier Lyapunov function within a nonlinear framework. The six degree-of-freedom dynamics of the quadrotor is also accounted for during control design that yields a high precision in the tracking performance. Owing to the nonlinear framework, the controllers remain effective even in the presence of large initial deviations, subjected to some mild conditions on initial quadrotor's states. The proposed controllers also avoid the possibility of well-known singularity issues associated with the Euler angles representation of attitude. Numerical simulations are performed using quadrotor's dynamic model to validate the claims of the proposed controller, and shown to yield satisfactory performance.