Adaptive Integral Backstepping Control for a Quadrotor with Suspended Flight

Aiming at the problem that the stability of a quadrotor with a suspension system is affected by the swing of the slung-load due to the wind and so on, a nonlinear control method is proposed to reduce the influence of the slung-load on the flight of the quadrotor. Firstly, the mathematical model of the suspension system of the quadrotor is established by using Hamilton principle and Lagrange formula; secondly, the adaptive backstepping controller is designed to control the position and attitude of the quadrotor, and eliminate the steady-state error of the system and enhance the robustness of the system; thirdly, the integral backstepping controller is designed to reduce the swing of the slung-load; finally, the simulation experiment system of the quadrotor with a slung-load suspension is built. The simulation experiment results verify the validity and accuracy of mathematical model and designed controller.