Fixed-time adaptive control of quadrotor suspension system with unknown payload mass

This paper investigates the control challenges of quadrotor suspension systems with unknown payload masses. To address the unknown external disturbances, uncertainties in system models, and unknown payloads, fixed-time stable adaptive laws are developed to estimate and compensate for these unknown factors. Additionally, a novel control structure based on a nonlinear backstepping controller is proposed for the quadrotor suspension system, achieving stable control of the quadrotor and reducing the sway of the suspended payload. The fixed-time stability of the designed closed-loop system is analytically proven using Lyapunov functions, ensuring maximum stability time. Simulink simulations validate the proposed control approach, demonstrating accurate estimation of unknown masses and the effectiveness and superiority of the controller.