The design of sliding mode control system based on backstepping theory for BTT UAV

A novel control system design approach is proposed based on backstepping theory and sliding mode control (SMC) for Bank-To-Turn (BTT) Unmanned Aerial Vehicle (UAV). It ensures BTT UAV stable and accurate flight under large parametric perturbation. In addition, the aerodynamic coefficients are not necessary to be identified online. This approach is based on backstepping theory and the whole system is not divided into slow and fast subsystems. However, backstepping cannot ensure the robustness of the closed-loop system. To solve this problem, SMC is employed, which is designed in terms of the bounds of aerodynamic coefficients. To evaluate the performance of the flight control system using the proposed approach, the three channels united simulation is conducted considering the actuators' rate and magnitude saturation. The results show that the proposed approach is capable of handling serious nonlinear and large model uncertainty.