Fuzzy Adaptive Backstepping Trajectory Tracking Control of Quadrotor Suspension System with Input Saturation

This paper introduces a novel control method for the quadrotor suspension system, addressing the challenges posed by a suspended load, external disturbances, input saturation and model dynamic uncertainty. The primary goal of this method is to achieve precise quadrotor trajectory tracking while minimizing oscillations in the suspended load. To model the system, the Udwadia-Kalaba equation is employed to handle the interaction between the quadrotor and the suspended load. Input saturation is mitigated using the hyperbolic tangent function, and a trapezoidal acceleration algorithm is utilized for trajectory design. To deal with composite disturbances, an adaptive fuzzy control method is developed and a double closed-loop nonlinear control method ensures system stability based on the Lyapunov stabilization criterion. Simulation results confirm the method's effectiveness in accurately regulating the quadrotor system in the presence of external disturbances and model uncertainties, while also reducing suspended load oscillations under input saturation conditions.