Altitude Stabilization of VTOL System With Nonlinear Control Strategy

This is the authors' abstract. We don't add key points for this paper.

The Vertical Take-Off and Landing (VTOL) system is a highly nonlinear system operating in severe ambient conditions, reflects the attention of the control engineering community. Robust control strategies are necessary to handle various perturbations while maintaining the altitude of the VTOL system. The objective of this research work is to develop and implement a nonlinear control strategy aimed at accurately tracking the pitch of the VTOL system using the Backstepping Control Strategy (BCS) and Super-Twisting Sliding Mode Control (STSMC) law, while effectively compensating for air resistances. Transient and steady-state analysis demonstrates that the pitch of the VTOL system controlled by the BCS, accurately tracks with a steady-state error of less than 5% as compared to STSMC. The controller input denoted dc current provided to the motor of the VTOL body shows minimal fluctuations increasing its reliability and life span based on nonlinear control strategy. The vital significance of this research article is to validate the robustness of BCS under external disturbances and parametric variations. Stability analysis of the BCS is performed using Lyapunov theory, a crucial step in validating the control law for flight dynamical systems prior to AAV takeoff.