Abstract
Quadrotor Uncrewed Aerial Vehicles (UAVs) find diverse applications in inspection, surveillance, and mapping. They are characterized by high maneuverability, low size and vertical take-off. In recent decades, model-based non-linear controllers have been designed to deal with the problem of trajectory tracking of these mobile robots. Among them, Sliding Mode Control (SMC) allows one to counterbalance unknown dynamics and external disturbances. However, classical SMC is affected by high-frequency oscillations, known as the chattering effect, which are induced by the discontinuous signum term included in the controller. Inspired by previous work, this paper proposes four sliding mode controllers for trajectory tracking of UAVs, with simple linearization of the model and use of Hurwitz stability to find the controllers gains. The benefit of these controllers is that they provide chattering-free SMC by approximating the signum function with a saturation function. The stability of the proposed closed-loop controllers is proven via Lyapunov analysis and their effectiveness is validated through simulations. © 2024 IEEE.