Theory and Practice for Trajectory Tracking of Quadrotor UAV Via a Fifth Generation Sliding Mode Approach

This paper presents an effective approach for a quadrotor during trajectory tracking seeking fixed-time stabilization and disturbance rejection. The quadrotor is modeled by Ordinary Differential Equations (ODE) while considering lumped disturbances. Theoretical control design and practical implementation are addressed in the paper. Motivated by the variable structure systems in the form of Sliding Mode Control (SMC) theory and homogeneous systems theory, a homogeneous-SMC-based flight control is proposed to achieve robust trajectory tracking along fixed-time stability. First, a Homogeneous Nonlinear Chattering-Free Terminal Sliding Manifold (HNCFTSM) is synthesized. Second, a Fifth Generation-based Fixed-Time SMC (FGFTSMC) is derived based on the designed HNCFTSM and an appropriate reaching law. Moreover, to suppress the disturbances polluting the system's dynamics, the control scheme is designed within an ADRC approach. The control design and the stability analysis show that the tracking errors are guaranteed to be fixed-time stable at the equilibrium point without being affected by the deviation of the Initial Conditions (ICs) from the origin. Outdoor flight experiments and comparative analysis are drawn to corroborate the findings of this note. The depicted outcomes approve the effectiveness of the suggested controller in the form of chattering alleviation, disturbance rejection, and uniform fast fixed-time convergence.